LCOV - code coverage report
Current view: top level - src/backend/utils/misc - guc.c (source / functions) Coverage Total Hit
Test: PostgreSQL 19devel Lines: 82.5 % 2232 1842
Test Date: 2026-03-11 22:14:46 Functions: 97.0 % 99 96
Legend: Lines:     hit not hit

            Line data    Source code
       1              : /*--------------------------------------------------------------------
       2              :  * guc.c
       3              :  *
       4              :  * Support for grand unified configuration scheme, including SET
       5              :  * command, configuration file, and command line options.
       6              :  *
       7              :  * This file contains the generic option processing infrastructure.
       8              :  * guc_funcs.c contains SQL-level functionality, including SET/SHOW
       9              :  * commands and various system-administration SQL functions.
      10              :  * guc_tables.c contains the arrays that define all the built-in
      11              :  * GUC variables.  Code that implements variable-specific behavior
      12              :  * is scattered around the system in check, assign, and show hooks.
      13              :  *
      14              :  * See src/backend/utils/misc/README for more information.
      15              :  *
      16              :  *
      17              :  * Copyright (c) 2000-2026, PostgreSQL Global Development Group
      18              :  * Written by Peter Eisentraut <peter_e@gmx.net>.
      19              :  *
      20              :  * IDENTIFICATION
      21              :  *    src/backend/utils/misc/guc.c
      22              :  *
      23              :  *--------------------------------------------------------------------
      24              :  */
      25              : #include "postgres.h"
      26              : 
      27              : #include <limits.h>
      28              : #include <math.h>
      29              : #include <sys/stat.h>
      30              : #include <unistd.h>
      31              : 
      32              : #include "access/xact.h"
      33              : #include "access/xlog.h"
      34              : #include "catalog/objectaccess.h"
      35              : #include "catalog/pg_authid.h"
      36              : #include "catalog/pg_parameter_acl.h"
      37              : #include "catalog/pg_type.h"
      38              : #include "guc_internal.h"
      39              : #include "libpq/pqformat.h"
      40              : #include "libpq/protocol.h"
      41              : #include "miscadmin.h"
      42              : #include "parser/scansup.h"
      43              : #include "port/pg_bitutils.h"
      44              : #include "storage/fd.h"
      45              : #include "storage/lwlock.h"
      46              : #include "storage/shmem.h"
      47              : #include "tcop/tcopprot.h"
      48              : #include "utils/acl.h"
      49              : #include "utils/builtins.h"
      50              : #include "utils/conffiles.h"
      51              : #include "utils/guc_tables.h"
      52              : #include "utils/memutils.h"
      53              : #include "utils/timestamp.h"
      54              : 
      55              : 
      56              : #define CONFIG_FILENAME "postgresql.conf"
      57              : #define HBA_FILENAME    "pg_hba.conf"
      58              : #define IDENT_FILENAME  "pg_ident.conf"
      59              : 
      60              : #ifdef EXEC_BACKEND
      61              : #define CONFIG_EXEC_PARAMS "global/config_exec_params"
      62              : #define CONFIG_EXEC_PARAMS_NEW "global/config_exec_params.new"
      63              : #endif
      64              : 
      65              : /*
      66              :  * Precision with which REAL type guc values are to be printed for GUC
      67              :  * serialization.
      68              :  */
      69              : #define REALTYPE_PRECISION 17
      70              : 
      71              : /*
      72              :  * Safe search path when executing code as the table owner, such as during
      73              :  * maintenance operations.
      74              :  */
      75              : #define GUC_SAFE_SEARCH_PATH "pg_catalog, pg_temp"
      76              : 
      77              : static int  GUC_check_errcode_value;
      78              : 
      79              : static List *reserved_class_prefix = NIL;
      80              : 
      81              : /* global variables for check hook support */
      82              : char       *GUC_check_errmsg_string;
      83              : char       *GUC_check_errdetail_string;
      84              : char       *GUC_check_errhint_string;
      85              : 
      86              : 
      87              : /*
      88              :  * Unit conversion tables.
      89              :  *
      90              :  * There are two tables, one for memory units, and another for time units.
      91              :  * For each supported conversion from one unit to another, we have an entry
      92              :  * in the table.
      93              :  *
      94              :  * To keep things simple, and to avoid possible roundoff error,
      95              :  * conversions are never chained.  There needs to be a direct conversion
      96              :  * between all units (of the same type).
      97              :  *
      98              :  * The conversions for each base unit must be kept in order from greatest to
      99              :  * smallest human-friendly unit; convert_xxx_from_base_unit() rely on that.
     100              :  * (The order of the base-unit groups does not matter.)
     101              :  */
     102              : #define MAX_UNIT_LEN        3   /* length of longest recognized unit string */
     103              : 
     104              : typedef struct
     105              : {
     106              :     char        unit[MAX_UNIT_LEN + 1]; /* unit, as a string, like "kB" or
     107              :                                          * "min" */
     108              :     int         base_unit;      /* GUC_UNIT_XXX */
     109              :     double      multiplier;     /* Factor for converting unit -> base_unit */
     110              : } unit_conversion;
     111              : 
     112              : /* Ensure that the constants in the tables don't overflow or underflow */
     113              : #if BLCKSZ < 1024 || BLCKSZ > (1024*1024)
     114              : #error BLCKSZ must be between 1KB and 1MB
     115              : #endif
     116              : #if XLOG_BLCKSZ < 1024 || XLOG_BLCKSZ > (1024*1024)
     117              : #error XLOG_BLCKSZ must be between 1KB and 1MB
     118              : #endif
     119              : 
     120              : static const char *const memory_units_hint = gettext_noop("Valid units for this parameter are \"B\", \"kB\", \"MB\", \"GB\", and \"TB\".");
     121              : 
     122              : static const unit_conversion memory_unit_conversion_table[] =
     123              : {
     124              :     {"TB", GUC_UNIT_BYTE, 1024.0 * 1024.0 * 1024.0 * 1024.0},
     125              :     {"GB", GUC_UNIT_BYTE, 1024.0 * 1024.0 * 1024.0},
     126              :     {"MB", GUC_UNIT_BYTE, 1024.0 * 1024.0},
     127              :     {"kB", GUC_UNIT_BYTE, 1024.0},
     128              :     {"B", GUC_UNIT_BYTE, 1.0},
     129              : 
     130              :     {"TB", GUC_UNIT_KB, 1024.0 * 1024.0 * 1024.0},
     131              :     {"GB", GUC_UNIT_KB, 1024.0 * 1024.0},
     132              :     {"MB", GUC_UNIT_KB, 1024.0},
     133              :     {"kB", GUC_UNIT_KB, 1.0},
     134              :     {"B", GUC_UNIT_KB, 1.0 / 1024.0},
     135              : 
     136              :     {"TB", GUC_UNIT_MB, 1024.0 * 1024.0},
     137              :     {"GB", GUC_UNIT_MB, 1024.0},
     138              :     {"MB", GUC_UNIT_MB, 1.0},
     139              :     {"kB", GUC_UNIT_MB, 1.0 / 1024.0},
     140              :     {"B", GUC_UNIT_MB, 1.0 / (1024.0 * 1024.0)},
     141              : 
     142              :     {"TB", GUC_UNIT_BLOCKS, (1024.0 * 1024.0 * 1024.0) / (BLCKSZ / 1024)},
     143              :     {"GB", GUC_UNIT_BLOCKS, (1024.0 * 1024.0) / (BLCKSZ / 1024)},
     144              :     {"MB", GUC_UNIT_BLOCKS, 1024.0 / (BLCKSZ / 1024)},
     145              :     {"kB", GUC_UNIT_BLOCKS, 1.0 / (BLCKSZ / 1024)},
     146              :     {"B", GUC_UNIT_BLOCKS, 1.0 / BLCKSZ},
     147              : 
     148              :     {"TB", GUC_UNIT_XBLOCKS, (1024.0 * 1024.0 * 1024.0) / (XLOG_BLCKSZ / 1024)},
     149              :     {"GB", GUC_UNIT_XBLOCKS, (1024.0 * 1024.0) / (XLOG_BLCKSZ / 1024)},
     150              :     {"MB", GUC_UNIT_XBLOCKS, 1024.0 / (XLOG_BLCKSZ / 1024)},
     151              :     {"kB", GUC_UNIT_XBLOCKS, 1.0 / (XLOG_BLCKSZ / 1024)},
     152              :     {"B", GUC_UNIT_XBLOCKS, 1.0 / XLOG_BLCKSZ},
     153              : 
     154              :     {""}                      /* end of table marker */
     155              : };
     156              : 
     157              : static const char *const time_units_hint = gettext_noop("Valid units for this parameter are \"us\", \"ms\", \"s\", \"min\", \"h\", and \"d\".");
     158              : 
     159              : static const unit_conversion time_unit_conversion_table[] =
     160              : {
     161              :     {"d", GUC_UNIT_MS, 1000 * 60 * 60 * 24},
     162              :     {"h", GUC_UNIT_MS, 1000 * 60 * 60},
     163              :     {"min", GUC_UNIT_MS, 1000 * 60},
     164              :     {"s", GUC_UNIT_MS, 1000},
     165              :     {"ms", GUC_UNIT_MS, 1},
     166              :     {"us", GUC_UNIT_MS, 1.0 / 1000},
     167              : 
     168              :     {"d", GUC_UNIT_S, 60 * 60 * 24},
     169              :     {"h", GUC_UNIT_S, 60 * 60},
     170              :     {"min", GUC_UNIT_S, 60},
     171              :     {"s", GUC_UNIT_S, 1},
     172              :     {"ms", GUC_UNIT_S, 1.0 / 1000},
     173              :     {"us", GUC_UNIT_S, 1.0 / (1000 * 1000)},
     174              : 
     175              :     {"d", GUC_UNIT_MIN, 60 * 24},
     176              :     {"h", GUC_UNIT_MIN, 60},
     177              :     {"min", GUC_UNIT_MIN, 1},
     178              :     {"s", GUC_UNIT_MIN, 1.0 / 60},
     179              :     {"ms", GUC_UNIT_MIN, 1.0 / (1000 * 60)},
     180              :     {"us", GUC_UNIT_MIN, 1.0 / (1000 * 1000 * 60)},
     181              : 
     182              :     {""}                      /* end of table marker */
     183              : };
     184              : 
     185              : /*
     186              :  * To allow continued support of obsolete names for GUC variables, we apply
     187              :  * the following mappings to any unrecognized name.  Note that an old name
     188              :  * should be mapped to a new one only if the new variable has very similar
     189              :  * semantics to the old.
     190              :  */
     191              : static const char *const map_old_guc_names[] = {
     192              :     "sort_mem", "work_mem",
     193              :     "vacuum_mem", "maintenance_work_mem",
     194              :     "ssl_ecdh_curve", "ssl_groups",
     195              :     NULL
     196              : };
     197              : 
     198              : 
     199              : /* Memory context holding all GUC-related data */
     200              : static MemoryContext GUCMemoryContext;
     201              : 
     202              : /*
     203              :  * We use a dynahash table to look up GUCs by name, or to iterate through
     204              :  * all the GUCs.  The gucname field is redundant with gucvar->name, but
     205              :  * dynahash makes it too painful to not store the hash key separately.
     206              :  */
     207              : typedef struct
     208              : {
     209              :     const char *gucname;        /* hash key */
     210              :     struct config_generic *gucvar;  /* -> GUC's defining structure */
     211              : } GUCHashEntry;
     212              : 
     213              : static HTAB *guc_hashtab;       /* entries are GUCHashEntrys */
     214              : 
     215              : /*
     216              :  * In addition to the hash table, variables having certain properties are
     217              :  * linked into these lists, so that we can find them without scanning the
     218              :  * whole hash table.  In most applications, only a small fraction of the
     219              :  * GUCs appear in these lists at any given time.  The usage of the stack
     220              :  * and report lists is stylized enough that they can be slists, but the
     221              :  * nondef list has to be a dlist to avoid O(N) deletes in common cases.
     222              :  */
     223              : static dlist_head guc_nondef_list;  /* list of variables that have source
     224              :                                      * different from PGC_S_DEFAULT */
     225              : static slist_head guc_stack_list;   /* list of variables that have non-NULL
     226              :                                      * stack */
     227              : static slist_head guc_report_list;  /* list of variables that have the
     228              :                                      * GUC_NEEDS_REPORT bit set in status */
     229              : 
     230              : static bool reporting_enabled;  /* true to enable GUC_REPORT */
     231              : 
     232              : static int  GUCNestLevel = 0;   /* 1 when in main transaction */
     233              : 
     234              : 
     235              : static int  guc_var_compare(const void *a, const void *b);
     236              : static uint32 guc_name_hash(const void *key, Size keysize);
     237              : static int  guc_name_match(const void *key1, const void *key2, Size keysize);
     238              : static void InitializeGUCOptionsFromEnvironment(void);
     239              : static void InitializeOneGUCOption(struct config_generic *gconf);
     240              : static void RemoveGUCFromLists(struct config_generic *gconf);
     241              : static void set_guc_source(struct config_generic *gconf, GucSource newsource);
     242              : static void pg_timezone_abbrev_initialize(void);
     243              : static void push_old_value(struct config_generic *gconf, GucAction action);
     244              : static void ReportGUCOption(struct config_generic *record);
     245              : static void set_config_sourcefile(const char *name, char *sourcefile,
     246              :                                   int sourceline);
     247              : static void reapply_stacked_values(struct config_generic *variable,
     248              :                                    struct config_generic *pHolder,
     249              :                                    GucStack *stack,
     250              :                                    const char *curvalue,
     251              :                                    GucContext curscontext, GucSource cursource,
     252              :                                    Oid cursrole);
     253              : static void free_placeholder(struct config_generic *pHolder);
     254              : static bool validate_option_array_item(const char *name, const char *value,
     255              :                                        bool skipIfNoPermissions);
     256              : static void write_auto_conf_file(int fd, const char *filename, ConfigVariable *head);
     257              : static void replace_auto_config_value(ConfigVariable **head_p, ConfigVariable **tail_p,
     258              :                                       const char *name, const char *value);
     259              : static bool valid_custom_variable_name(const char *name);
     260              : static bool assignable_custom_variable_name(const char *name, bool skip_errors,
     261              :                                             int elevel);
     262              : static void do_serialize(char **destptr, Size *maxbytes,
     263              :                          const char *fmt,...) pg_attribute_printf(3, 4);
     264              : static bool call_bool_check_hook(const struct config_generic *conf, bool *newval,
     265              :                                  void **extra, GucSource source, int elevel);
     266              : static bool call_int_check_hook(const struct config_generic *conf, int *newval,
     267              :                                 void **extra, GucSource source, int elevel);
     268              : static bool call_real_check_hook(const struct config_generic *conf, double *newval,
     269              :                                  void **extra, GucSource source, int elevel);
     270              : static bool call_string_check_hook(const struct config_generic *conf, char **newval,
     271              :                                    void **extra, GucSource source, int elevel);
     272              : static bool call_enum_check_hook(const struct config_generic *conf, int *newval,
     273              :                                  void **extra, GucSource source, int elevel);
     274              : 
     275              : 
     276              : /*
     277              :  * This function handles both actual config file (re)loads and execution of
     278              :  * show_all_file_settings() (i.e., the pg_file_settings view).  In the latter
     279              :  * case we don't apply any of the settings, but we make all the usual validity
     280              :  * checks, and we return the ConfigVariable list so that it can be printed out
     281              :  * by show_all_file_settings().
     282              :  */
     283              : ConfigVariable *
     284         3141 : ProcessConfigFileInternal(GucContext context, bool applySettings, int elevel)
     285              : {
     286         3141 :     bool        error = false;
     287         3141 :     bool        applying = false;
     288              :     const char *ConfFileWithError;
     289              :     ConfigVariable *head,
     290              :                *tail;
     291              :     HASH_SEQ_STATUS status;
     292              :     GUCHashEntry *hentry;
     293              : 
     294              :     /* Parse the main config file into a list of option names and values */
     295         3141 :     ConfFileWithError = ConfigFileName;
     296         3141 :     head = tail = NULL;
     297              : 
     298         3141 :     if (!ParseConfigFile(ConfigFileName, true,
     299              :                          NULL, 0, CONF_FILE_START_DEPTH, elevel,
     300              :                          &head, &tail))
     301              :     {
     302              :         /* Syntax error(s) detected in the file, so bail out */
     303            0 :         error = true;
     304            0 :         goto bail_out;
     305              :     }
     306              : 
     307              :     /*
     308              :      * Parse the PG_AUTOCONF_FILENAME file, if present, after the main file to
     309              :      * replace any parameters set by ALTER SYSTEM command.  Because this file
     310              :      * is in the data directory, we can't read it until the DataDir has been
     311              :      * set.
     312              :      */
     313         3141 :     if (DataDir)
     314              :     {
     315         1975 :         if (!ParseConfigFile(PG_AUTOCONF_FILENAME, false,
     316              :                              NULL, 0, CONF_FILE_START_DEPTH, elevel,
     317              :                              &head, &tail))
     318              :         {
     319              :             /* Syntax error(s) detected in the file, so bail out */
     320            0 :             error = true;
     321            0 :             ConfFileWithError = PG_AUTOCONF_FILENAME;
     322            0 :             goto bail_out;
     323              :         }
     324              :     }
     325              :     else
     326              :     {
     327              :         /*
     328              :          * If DataDir is not set, the PG_AUTOCONF_FILENAME file cannot be
     329              :          * read.  In this case, we don't want to accept any settings but
     330              :          * data_directory from postgresql.conf, because they might be
     331              :          * overwritten with settings in the PG_AUTOCONF_FILENAME file which
     332              :          * will be read later. OTOH, since data_directory isn't allowed in the
     333              :          * PG_AUTOCONF_FILENAME file, it will never be overwritten later.
     334              :          */
     335         1166 :         ConfigVariable *newlist = NULL;
     336              : 
     337              :         /*
     338              :          * Prune all items except the last "data_directory" from the list.
     339              :          */
     340        32092 :         for (ConfigVariable *item = head; item; item = item->next)
     341              :         {
     342        30926 :             if (!item->ignore &&
     343        30926 :                 strcmp(item->name, "data_directory") == 0)
     344            0 :                 newlist = item;
     345              :         }
     346              : 
     347         1166 :         if (newlist)
     348            0 :             newlist->next = NULL;
     349         1166 :         head = tail = newlist;
     350              : 
     351              :         /*
     352              :          * Quick exit if data_directory is not present in file.
     353              :          *
     354              :          * We need not do any further processing, in particular we don't set
     355              :          * PgReloadTime; that will be set soon by subsequent full loading of
     356              :          * the config file.
     357              :          */
     358         1166 :         if (head == NULL)
     359         1166 :             goto bail_out;
     360              :     }
     361              : 
     362              :     /*
     363              :      * Mark all extant GUC variables as not present in the config file. We
     364              :      * need this so that we can tell below which ones have been removed from
     365              :      * the file since we last processed it.
     366              :      */
     367         1975 :     hash_seq_init(&status, guc_hashtab);
     368       817707 :     while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
     369              :     {
     370       815732 :         struct config_generic *gconf = hentry->gucvar;
     371              : 
     372       815732 :         gconf->status &= ~GUC_IS_IN_FILE;
     373              :     }
     374              : 
     375              :     /*
     376              :      * Check if all the supplied option names are valid, as an additional
     377              :      * quasi-syntactic check on the validity of the config file.  It is
     378              :      * important that the postmaster and all backends agree on the results of
     379              :      * this phase, else we will have strange inconsistencies about which
     380              :      * processes accept a config file update and which don't.  Hence, unknown
     381              :      * custom variable names have to be accepted without complaint.  For the
     382              :      * same reason, we don't attempt to validate the options' values here.
     383              :      *
     384              :      * In addition, the GUC_IS_IN_FILE flag is set on each existing GUC
     385              :      * variable mentioned in the file; and we detect duplicate entries in the
     386              :      * file and mark the earlier occurrences as ignorable.
     387              :      */
     388        61269 :     for (ConfigVariable *item = head; item; item = item->next)
     389              :     {
     390              :         struct config_generic *record;
     391              : 
     392              :         /* Ignore anything already marked as ignorable */
     393        59294 :         if (item->ignore)
     394            0 :             continue;
     395              : 
     396              :         /*
     397              :          * Try to find the variable; but do not create a custom placeholder if
     398              :          * it's not there already.
     399              :          */
     400        59294 :         record = find_option(item->name, false, true, elevel);
     401              : 
     402        59294 :         if (record)
     403              :         {
     404              :             /* If it's already marked, then this is a duplicate entry */
     405        59266 :             if (record->status & GUC_IS_IN_FILE)
     406              :             {
     407              :                 /*
     408              :                  * Mark the earlier occurrence(s) as dead/ignorable.  We could
     409              :                  * avoid the O(N^2) behavior here with some additional state,
     410              :                  * but it seems unlikely to be worth the trouble.
     411              :                  */
     412       211128 :                 for (ConfigVariable *pitem = head; pitem != item; pitem = pitem->next)
     413              :                 {
     414       204494 :                     if (!pitem->ignore &&
     415       181834 :                         strcmp(pitem->name, item->name) == 0)
     416         6634 :                         pitem->ignore = true;
     417              :                 }
     418              :             }
     419              :             /* Now mark it as present in file */
     420        59266 :             record->status |= GUC_IS_IN_FILE;
     421              :         }
     422           28 :         else if (!valid_custom_variable_name(item->name))
     423              :         {
     424              :             /* Invalid non-custom variable, so complain */
     425            1 :             ereport(elevel,
     426              :                     (errcode(ERRCODE_UNDEFINED_OBJECT),
     427              :                      errmsg("unrecognized configuration parameter \"%s\" in file \"%s\" line %d",
     428              :                             item->name,
     429              :                             item->filename, item->sourceline)));
     430            1 :             item->errmsg = pstrdup("unrecognized configuration parameter");
     431            1 :             error = true;
     432            1 :             ConfFileWithError = item->filename;
     433              :         }
     434              :     }
     435              : 
     436              :     /*
     437              :      * If we've detected any errors so far, we don't want to risk applying any
     438              :      * changes.
     439              :      */
     440         1975 :     if (error)
     441            1 :         goto bail_out;
     442              : 
     443              :     /* Otherwise, set flag that we're beginning to apply changes */
     444         1974 :     applying = true;
     445              : 
     446              :     /*
     447              :      * Check for variables having been removed from the config file, and
     448              :      * revert their reset values (and perhaps also effective values) to the
     449              :      * boot-time defaults.  If such a variable can't be changed after startup,
     450              :      * report that and continue.
     451              :      */
     452         1974 :     hash_seq_init(&status, guc_hashtab);
     453       817293 :     while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
     454              :     {
     455       815319 :         struct config_generic *gconf = hentry->gucvar;
     456              : 
     457       815319 :         if (gconf->reset_source != PGC_S_FILE ||
     458        24134 :             (gconf->status & GUC_IS_IN_FILE))
     459       815318 :             continue;
     460            1 :         if (gconf->context < PGC_SIGHUP)
     461              :         {
     462              :             /* The removal can't be effective without a restart */
     463            0 :             gconf->status |= GUC_PENDING_RESTART;
     464            0 :             ereport(elevel,
     465              :                     (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
     466              :                      errmsg("parameter \"%s\" cannot be changed without restarting the server",
     467              :                             gconf->name)));
     468            0 :             record_config_file_error(psprintf("parameter \"%s\" cannot be changed without restarting the server",
     469              :                                               gconf->name),
     470              :                                      NULL, 0,
     471              :                                      &head, &tail);
     472            0 :             error = true;
     473            0 :             continue;
     474              :         }
     475              : 
     476              :         /* No more to do if we're just doing show_all_file_settings() */
     477            1 :         if (!applySettings)
     478            0 :             continue;
     479              : 
     480              :         /*
     481              :          * Reset any "file" sources to "default", else set_config_option will
     482              :          * not override those settings.
     483              :          */
     484            1 :         if (gconf->reset_source == PGC_S_FILE)
     485            1 :             gconf->reset_source = PGC_S_DEFAULT;
     486            1 :         if (gconf->source == PGC_S_FILE)
     487            1 :             set_guc_source(gconf, PGC_S_DEFAULT);
     488            1 :         for (GucStack *stack = gconf->stack; stack; stack = stack->prev)
     489              :         {
     490            0 :             if (stack->source == PGC_S_FILE)
     491            0 :                 stack->source = PGC_S_DEFAULT;
     492              :         }
     493              : 
     494              :         /* Now we can re-apply the wired-in default (i.e., the boot_val) */
     495            1 :         if (set_config_option(gconf->name, NULL,
     496              :                               context, PGC_S_DEFAULT,
     497              :                               GUC_ACTION_SET, true, 0, false) > 0)
     498              :         {
     499              :             /* Log the change if appropriate */
     500            1 :             if (context == PGC_SIGHUP)
     501            1 :                 ereport(elevel,
     502              :                         (errmsg("parameter \"%s\" removed from configuration file, reset to default",
     503              :                                 gconf->name)));
     504              :         }
     505              :     }
     506              : 
     507              :     /*
     508              :      * Restore any variables determined by environment variables or
     509              :      * dynamically-computed defaults.  This is a no-op except in the case
     510              :      * where one of these had been in the config file and is now removed.
     511              :      *
     512              :      * In particular, we *must not* do this during the postmaster's initial
     513              :      * loading of the file, since the timezone functions in particular should
     514              :      * be run only after initialization is complete.
     515              :      *
     516              :      * XXX this is an unmaintainable crock, because we have to know how to set
     517              :      * (or at least what to call to set) every non-PGC_INTERNAL variable that
     518              :      * could potentially have PGC_S_DYNAMIC_DEFAULT or PGC_S_ENV_VAR source.
     519              :      */
     520         1974 :     if (context == PGC_SIGHUP && applySettings)
     521              :     {
     522          806 :         InitializeGUCOptionsFromEnvironment();
     523          806 :         pg_timezone_abbrev_initialize();
     524              :         /* this selects SQL_ASCII in processes not connected to a database */
     525          806 :         SetConfigOption("client_encoding", GetDatabaseEncodingName(),
     526              :                         PGC_BACKEND, PGC_S_DYNAMIC_DEFAULT);
     527              :     }
     528              : 
     529              :     /*
     530              :      * Now apply the values from the config file.
     531              :      */
     532        61252 :     for (ConfigVariable *item = head; item; item = item->next)
     533              :     {
     534        59279 :         char       *pre_value = NULL;
     535              :         int         scres;
     536              : 
     537              :         /* Ignore anything marked as ignorable */
     538        59279 :         if (item->ignore)
     539         6634 :             continue;
     540              : 
     541              :         /* In SIGHUP cases in the postmaster, we want to report changes */
     542        52645 :         if (context == PGC_SIGHUP && applySettings && !IsUnderPostmaster)
     543              :         {
     544         4485 :             const char *preval = GetConfigOption(item->name, true, false);
     545              : 
     546              :             /* If option doesn't exist yet or is NULL, treat as empty string */
     547         4485 :             if (!preval)
     548            1 :                 preval = "";
     549              :             /* must dup, else might have dangling pointer below */
     550         4485 :             pre_value = pstrdup(preval);
     551              :         }
     552              : 
     553        52645 :         scres = set_config_option(item->name, item->value,
     554              :                                   context, PGC_S_FILE,
     555              :                                   GUC_ACTION_SET, applySettings, 0, false);
     556        52644 :         if (scres > 0)
     557              :         {
     558              :             /* variable was updated, so log the change if appropriate */
     559        43264 :             if (pre_value)
     560              :             {
     561         2841 :                 const char *post_value = GetConfigOption(item->name, true, false);
     562              : 
     563         2841 :                 if (!post_value)
     564            0 :                     post_value = "";
     565         2841 :                 if (strcmp(pre_value, post_value) != 0)
     566          115 :                     ereport(elevel,
     567              :                             (errmsg("parameter \"%s\" changed to \"%s\"",
     568              :                                     item->name, item->value)));
     569              :             }
     570        43264 :             item->applied = true;
     571              :         }
     572         9380 :         else if (scres == 0)
     573              :         {
     574            0 :             error = true;
     575            0 :             item->errmsg = pstrdup("setting could not be applied");
     576            0 :             ConfFileWithError = item->filename;
     577              :         }
     578              :         else
     579              :         {
     580              :             /* no error, but variable's active value was not changed */
     581         9380 :             item->applied = true;
     582              :         }
     583              : 
     584              :         /*
     585              :          * We should update source location unless there was an error, since
     586              :          * even if the active value didn't change, the reset value might have.
     587              :          * (In the postmaster, there won't be a difference, but it does matter
     588              :          * in backends.)
     589              :          */
     590        52644 :         if (scres != 0 && applySettings)
     591        52563 :             set_config_sourcefile(item->name, item->filename,
     592              :                                   item->sourceline);
     593              : 
     594        52644 :         if (pre_value)
     595         4485 :             pfree(pre_value);
     596              :     }
     597              : 
     598              :     /* Remember when we last successfully loaded the config file. */
     599         1973 :     if (applySettings)
     600         1970 :         PgReloadTime = GetCurrentTimestamp();
     601              : 
     602            3 : bail_out:
     603         3140 :     if (error && applySettings)
     604              :     {
     605              :         /* During postmaster startup, any error is fatal */
     606            1 :         if (context == PGC_POSTMASTER)
     607            1 :             ereport(ERROR,
     608              :                     (errcode(ERRCODE_CONFIG_FILE_ERROR),
     609              :                      errmsg("configuration file \"%s\" contains errors",
     610              :                             ConfFileWithError)));
     611            0 :         else if (applying)
     612            0 :             ereport(elevel,
     613              :                     (errcode(ERRCODE_CONFIG_FILE_ERROR),
     614              :                      errmsg("configuration file \"%s\" contains errors; unaffected changes were applied",
     615              :                             ConfFileWithError)));
     616              :         else
     617            0 :             ereport(elevel,
     618              :                     (errcode(ERRCODE_CONFIG_FILE_ERROR),
     619              :                      errmsg("configuration file \"%s\" contains errors; no changes were applied",
     620              :                             ConfFileWithError)));
     621              :     }
     622              : 
     623              :     /* Successful or otherwise, return the collected data list */
     624         3139 :     return head;
     625              : }
     626              : 
     627              : 
     628              : /*
     629              :  * Some infrastructure for GUC-related memory allocation
     630              :  *
     631              :  * These functions are generally modeled on libc's malloc/realloc/etc,
     632              :  * but any OOM issue is reported at the specified elevel.
     633              :  * (Thus, control returns only if that's less than ERROR.)
     634              :  */
     635              : void *
     636       930567 : guc_malloc(int elevel, size_t size)
     637              : {
     638              :     void       *data;
     639              : 
     640       930567 :     data = MemoryContextAllocExtended(GUCMemoryContext, size,
     641              :                                       MCXT_ALLOC_NO_OOM);
     642       930567 :     if (unlikely(data == NULL))
     643            0 :         ereport(elevel,
     644              :                 (errcode(ERRCODE_OUT_OF_MEMORY),
     645              :                  errmsg("out of memory")));
     646       930567 :     return data;
     647              : }
     648              : 
     649              : void *
     650            0 : guc_realloc(int elevel, void *old, size_t size)
     651              : {
     652              :     void       *data;
     653              : 
     654            0 :     if (old != NULL)
     655              :     {
     656              :         /* This is to help catch old code that malloc's GUC data. */
     657              :         Assert(GetMemoryChunkContext(old) == GUCMemoryContext);
     658            0 :         data = repalloc_extended(old, size,
     659              :                                  MCXT_ALLOC_NO_OOM);
     660              :     }
     661              :     else
     662              :     {
     663              :         /* Like realloc(3), but not like repalloc(), we allow old == NULL. */
     664            0 :         data = MemoryContextAllocExtended(GUCMemoryContext, size,
     665              :                                           MCXT_ALLOC_NO_OOM);
     666              :     }
     667            0 :     if (unlikely(data == NULL))
     668            0 :         ereport(elevel,
     669              :                 (errcode(ERRCODE_OUT_OF_MEMORY),
     670              :                  errmsg("out of memory")));
     671            0 :     return data;
     672              : }
     673              : 
     674              : char *
     675       791540 : guc_strdup(int elevel, const char *src)
     676              : {
     677              :     char       *data;
     678       791540 :     size_t      len = strlen(src) + 1;
     679              : 
     680       791540 :     data = guc_malloc(elevel, len);
     681       791540 :     if (likely(data != NULL))
     682       791540 :         memcpy(data, src, len);
     683       791540 :     return data;
     684              : }
     685              : 
     686              : void
     687       862232 : guc_free(void *ptr)
     688              : {
     689              :     /*
     690              :      * Historically, GUC-related code has relied heavily on the ability to do
     691              :      * free(NULL), so we allow that here even though pfree() doesn't.
     692              :      */
     693       862232 :     if (ptr != NULL)
     694              :     {
     695              :         /* This is to help catch old code that malloc's GUC data. */
     696              :         Assert(GetMemoryChunkContext(ptr) == GUCMemoryContext);
     697       523397 :         pfree(ptr);
     698              :     }
     699       862232 : }
     700              : 
     701              : 
     702              : /*
     703              :  * Detect whether strval is referenced anywhere in a GUC string item
     704              :  */
     705              : static bool
     706      1229601 : string_field_used(struct config_generic *conf, char *strval)
     707              : {
     708      1229601 :     if (strval == *(conf->_string.variable) ||
     709       675048 :         strval == conf->_string.reset_val ||
     710       378085 :         strval == conf->_string.boot_val)
     711       851516 :         return true;
     712       595805 :     for (GucStack *stack = conf->stack; stack; stack = stack->prev)
     713              :     {
     714       262894 :         if (strval == stack->prior.val.stringval ||
     715       217723 :             strval == stack->masked.val.stringval)
     716        45174 :             return true;
     717              :     }
     718       332911 :     return false;
     719              : }
     720              : 
     721              : /*
     722              :  * Support for assigning to a field of a string GUC item.  Free the prior
     723              :  * value if it's not referenced anywhere else in the item (including stacked
     724              :  * states).
     725              :  */
     726              : static void
     727      1313603 : set_string_field(struct config_generic *conf, char **field, char *newval)
     728              : {
     729      1313603 :     char       *oldval = *field;
     730              : 
     731              :     /* Do the assignment */
     732      1313603 :     *field = newval;
     733              : 
     734              :     /* Free old value if it's not NULL and isn't referenced anymore */
     735      1313603 :     if (oldval && !string_field_used(conf, oldval))
     736       330431 :         guc_free(oldval);
     737      1313603 : }
     738              : 
     739              : /*
     740              :  * Detect whether an "extra" struct is referenced anywhere in a GUC item
     741              :  */
     742              : static bool
     743       226009 : extra_field_used(struct config_generic *gconf, void *extra)
     744              : {
     745       226009 :     if (extra == gconf->extra)
     746        90941 :         return true;
     747       135068 :     if (extra == gconf->reset_extra)
     748        66587 :         return true;
     749        76228 :     for (GucStack *stack = gconf->stack; stack; stack = stack->prev)
     750              :     {
     751        10992 :         if (extra == stack->prior.extra ||
     752         7750 :             extra == stack->masked.extra)
     753         3245 :             return true;
     754              :     }
     755              : 
     756        65236 :     return false;
     757              : }
     758              : 
     759              : /*
     760              :  * Support for assigning to an "extra" field of a GUC item.  Free the prior
     761              :  * value if it's not referenced anywhere else in the item (including stacked
     762              :  * states).
     763              :  */
     764              : static void
     765      1733348 : set_extra_field(struct config_generic *gconf, void **field, void *newval)
     766              : {
     767      1733348 :     void       *oldval = *field;
     768              : 
     769              :     /* Do the assignment */
     770      1733348 :     *field = newval;
     771              : 
     772              :     /* Free old value if it's not NULL and isn't referenced anymore */
     773      1733348 :     if (oldval && !extra_field_used(gconf, oldval))
     774        64982 :         guc_free(oldval);
     775      1733348 : }
     776              : 
     777              : /*
     778              :  * Support for copying a variable's active value into a stack entry.
     779              :  * The "extra" field associated with the active value is copied, too.
     780              :  *
     781              :  * NB: be sure stringval and extra fields of a new stack entry are
     782              :  * initialized to NULL before this is used, else we'll try to guc_free() them.
     783              :  */
     784              : static void
     785       241508 : set_stack_value(struct config_generic *gconf, config_var_value *val)
     786              : {
     787       241508 :     switch (gconf->vartype)
     788              :     {
     789         9732 :         case PGC_BOOL:
     790         9732 :             val->val.boolval = *gconf->_bool.variable;
     791         9732 :             break;
     792        11924 :         case PGC_INT:
     793        11924 :             val->val.intval = *gconf->_int.variable;
     794        11924 :             break;
     795         4343 :         case PGC_REAL:
     796         4343 :             val->val.realval = *gconf->_real.variable;
     797         4343 :             break;
     798       204985 :         case PGC_STRING:
     799       204985 :             set_string_field(gconf, &(val->val.stringval), *gconf->_string.variable);
     800       204985 :             break;
     801        10524 :         case PGC_ENUM:
     802        10524 :             val->val.enumval = *gconf->_enum.variable;
     803        10524 :             break;
     804              :     }
     805       241508 :     set_extra_field(gconf, &(val->extra), gconf->extra);
     806       241508 : }
     807              : 
     808              : /*
     809              :  * Support for discarding a no-longer-needed value in a stack entry.
     810              :  * The "extra" field associated with the stack entry is cleared, too.
     811              :  */
     812              : static void
     813        30558 : discard_stack_value(struct config_generic *gconf, config_var_value *val)
     814              : {
     815        30558 :     switch (gconf->vartype)
     816              :     {
     817        20143 :         case PGC_BOOL:
     818              :         case PGC_INT:
     819              :         case PGC_REAL:
     820              :         case PGC_ENUM:
     821              :             /* no need to do anything */
     822        20143 :             break;
     823        10415 :         case PGC_STRING:
     824        10415 :             set_string_field(gconf,
     825              :                              &(val->val.stringval),
     826              :                              NULL);
     827        10415 :             break;
     828              :     }
     829        30558 :     set_extra_field(gconf, &(val->extra), NULL);
     830        30558 : }
     831              : 
     832              : 
     833              : /*
     834              :  * Fetch a palloc'd, sorted array of GUC struct pointers
     835              :  *
     836              :  * The array length is returned into *num_vars.
     837              :  */
     838              : struct config_generic **
     839         1806 : get_guc_variables(int *num_vars)
     840              : {
     841              :     struct config_generic **result;
     842              :     HASH_SEQ_STATUS status;
     843              :     GUCHashEntry *hentry;
     844              :     int         i;
     845              : 
     846         1806 :     *num_vars = hash_get_num_entries(guc_hashtab);
     847         1806 :     result = palloc_array(struct config_generic *, *num_vars);
     848              : 
     849              :     /* Extract pointers from the hash table */
     850         1806 :     i = 0;
     851         1806 :     hash_seq_init(&status, guc_hashtab);
     852       755163 :     while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
     853       753357 :         result[i++] = hentry->gucvar;
     854              :     Assert(i == *num_vars);
     855              : 
     856              :     /* Sort by name */
     857         1806 :     qsort(result, *num_vars,
     858              :           sizeof(struct config_generic *), guc_var_compare);
     859              : 
     860         1806 :     return result;
     861              : }
     862              : 
     863              : 
     864              : /*
     865              :  * Build the GUC hash table.  This is split out so that help_config.c can
     866              :  * extract all the variables without running all of InitializeGUCOptions.
     867              :  * It's not meant for use anyplace else.
     868              :  */
     869              : void
     870         1192 : build_guc_variables(void)
     871              : {
     872              :     int         size_vars;
     873         1192 :     int         num_vars = 0;
     874              :     HASHCTL     hash_ctl;
     875              :     GUCHashEntry *hentry;
     876              :     bool        found;
     877              : 
     878              :     /*
     879              :      * Create the memory context that will hold all GUC-related data.
     880              :      */
     881              :     Assert(GUCMemoryContext == NULL);
     882         1192 :     GUCMemoryContext = AllocSetContextCreate(TopMemoryContext,
     883              :                                              "GUCMemoryContext",
     884              :                                              ALLOCSET_DEFAULT_SIZES);
     885              : 
     886              :     /*
     887              :      * Count all the built-in variables.
     888              :      */
     889       493488 :     for (int i = 0; ConfigureNames[i].name; i++)
     890       492296 :         num_vars++;
     891              : 
     892              :     /*
     893              :      * Create hash table with 20% slack
     894              :      */
     895         1192 :     size_vars = num_vars + num_vars / 4;
     896              : 
     897         1192 :     hash_ctl.keysize = sizeof(char *);
     898         1192 :     hash_ctl.entrysize = sizeof(GUCHashEntry);
     899         1192 :     hash_ctl.hash = guc_name_hash;
     900         1192 :     hash_ctl.match = guc_name_match;
     901         1192 :     hash_ctl.hcxt = GUCMemoryContext;
     902         1192 :     guc_hashtab = hash_create("GUC hash table",
     903              :                               size_vars,
     904              :                               &hash_ctl,
     905              :                               HASH_ELEM | HASH_FUNCTION | HASH_COMPARE | HASH_CONTEXT);
     906              : 
     907       493488 :     for (int i = 0; ConfigureNames[i].name; i++)
     908              :     {
     909       492296 :         struct config_generic *gucvar = &ConfigureNames[i];
     910              : 
     911       492296 :         hentry = (GUCHashEntry *) hash_search(guc_hashtab,
     912       492296 :                                               &gucvar->name,
     913              :                                               HASH_ENTER,
     914              :                                               &found);
     915              :         Assert(!found);
     916       492296 :         hentry->gucvar = gucvar;
     917              :     }
     918              : 
     919              :     Assert(num_vars == hash_get_num_entries(guc_hashtab));
     920         1192 : }
     921              : 
     922              : /*
     923              :  * Add a new GUC variable to the hash of known variables. The
     924              :  * hash is expanded if needed.
     925              :  */
     926              : static bool
     927         9665 : add_guc_variable(struct config_generic *var, int elevel)
     928              : {
     929              :     GUCHashEntry *hentry;
     930              :     bool        found;
     931              : 
     932         9665 :     hentry = (GUCHashEntry *) hash_search(guc_hashtab,
     933         9665 :                                           &var->name,
     934              :                                           HASH_ENTER_NULL,
     935              :                                           &found);
     936         9665 :     if (unlikely(hentry == NULL))
     937              :     {
     938            0 :         ereport(elevel,
     939              :                 (errcode(ERRCODE_OUT_OF_MEMORY),
     940              :                  errmsg("out of memory")));
     941            0 :         return false;           /* out of memory */
     942              :     }
     943              :     Assert(!found);
     944         9665 :     hentry->gucvar = var;
     945         9665 :     return true;
     946              : }
     947              : 
     948              : /*
     949              :  * Decide whether a proposed custom variable name is allowed.
     950              :  *
     951              :  * It must be two or more identifiers separated by dots, where the rules
     952              :  * for what is an identifier agree with scan.l.  (If you change this rule,
     953              :  * adjust the errdetail in assignable_custom_variable_name().)
     954              :  */
     955              : static bool
     956          127 : valid_custom_variable_name(const char *name)
     957              : {
     958          127 :     bool        saw_sep = false;
     959          127 :     bool        name_start = true;
     960              : 
     961         2381 :     for (const char *p = name; *p; p++)
     962              :     {
     963         2260 :         if (*p == GUC_QUALIFIER_SEPARATOR)
     964              :         {
     965          113 :             if (name_start)
     966            0 :                 return false;   /* empty name component */
     967          113 :             saw_sep = true;
     968          113 :             name_start = true;
     969              :         }
     970         2147 :         else if (strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ"
     971         2147 :                         "abcdefghijklmnopqrstuvwxyz_", *p) != NULL ||
     972            8 :                  IS_HIGHBIT_SET(*p))
     973              :         {
     974              :             /* okay as first or non-first character */
     975         2139 :             name_start = false;
     976              :         }
     977            8 :         else if (!name_start && strchr("0123456789$", *p) != NULL)
     978              :              /* okay as non-first character */ ;
     979              :         else
     980            6 :             return false;
     981              :     }
     982          121 :     if (name_start)
     983            0 :         return false;           /* empty name component */
     984              :     /* OK if we found at least one separator */
     985          121 :     return saw_sep;
     986              : }
     987              : 
     988              : /*
     989              :  * Decide whether an unrecognized variable name is allowed to be SET.
     990              :  *
     991              :  * It must pass the syntactic rules of valid_custom_variable_name(),
     992              :  * and it must not be in any namespace already reserved by an extension.
     993              :  * (We make this separate from valid_custom_variable_name() because we don't
     994              :  * apply the reserved-namespace test when reading configuration files.)
     995              :  *
     996              :  * If valid, return true.  Otherwise, return false if skip_errors is true,
     997              :  * else throw a suitable error at the specified elevel (and return false
     998              :  * if that's less than ERROR).
     999              :  */
    1000              : static bool
    1001          107 : assignable_custom_variable_name(const char *name, bool skip_errors, int elevel)
    1002              : {
    1003              :     /* If there's no separator, it can't be a custom variable */
    1004          107 :     const char *sep = strchr(name, GUC_QUALIFIER_SEPARATOR);
    1005              : 
    1006          107 :     if (sep != NULL)
    1007              :     {
    1008           76 :         size_t      classLen = sep - name;
    1009              :         ListCell   *lc;
    1010              : 
    1011              :         /* The name must be syntactically acceptable ... */
    1012           76 :         if (!valid_custom_variable_name(name))
    1013              :         {
    1014            6 :             if (!skip_errors)
    1015            6 :                 ereport(elevel,
    1016              :                         (errcode(ERRCODE_INVALID_NAME),
    1017              :                          errmsg("invalid configuration parameter name \"%s\"",
    1018              :                                 name),
    1019              :                          errdetail("Custom parameter names must be two or more simple identifiers separated by dots.")));
    1020            0 :             return false;
    1021              :         }
    1022              :         /* ... and it must not match any previously-reserved prefix */
    1023           84 :         foreach(lc, reserved_class_prefix)
    1024              :         {
    1025           20 :             const char *rcprefix = lfirst(lc);
    1026              : 
    1027           20 :             if (strlen(rcprefix) == classLen &&
    1028            6 :                 strncmp(name, rcprefix, classLen) == 0)
    1029              :             {
    1030            6 :                 if (!skip_errors)
    1031            3 :                     ereport(elevel,
    1032              :                             (errcode(ERRCODE_INVALID_NAME),
    1033              :                              errmsg("invalid configuration parameter name \"%s\"",
    1034              :                                     name),
    1035              :                              errdetail("\"%s\" is a reserved prefix.",
    1036              :                                        rcprefix)));
    1037            3 :                 return false;
    1038              :             }
    1039              :         }
    1040              :         /* OK to create it */
    1041           64 :         return true;
    1042              :     }
    1043              : 
    1044              :     /* Unrecognized single-part name */
    1045           31 :     if (!skip_errors)
    1046           31 :         ereport(elevel,
    1047              :                 (errcode(ERRCODE_UNDEFINED_OBJECT),
    1048              :                  errmsg("unrecognized configuration parameter \"%s\"",
    1049              :                         name)));
    1050            0 :     return false;
    1051              : }
    1052              : 
    1053              : /*
    1054              :  * Create and add a placeholder variable for a custom variable name.
    1055              :  */
    1056              : static struct config_generic *
    1057           57 : add_placeholder_variable(const char *name, int elevel)
    1058              : {
    1059           57 :     size_t      sz = sizeof(struct config_generic) + sizeof(char *);
    1060              :     struct config_generic *var;
    1061              : 
    1062           57 :     var = (struct config_generic *) guc_malloc(elevel, sz);
    1063           57 :     if (var == NULL)
    1064            0 :         return NULL;
    1065           57 :     memset(var, 0, sz);
    1066              : 
    1067           57 :     var->name = guc_strdup(elevel, name);
    1068           57 :     if (var->name == NULL)
    1069              :     {
    1070            0 :         guc_free(var);
    1071            0 :         return NULL;
    1072              :     }
    1073              : 
    1074           57 :     var->context = PGC_USERSET;
    1075           57 :     var->group = CUSTOM_OPTIONS;
    1076           57 :     var->short_desc = "GUC placeholder variable";
    1077           57 :     var->flags = GUC_NO_SHOW_ALL | GUC_NOT_IN_SAMPLE | GUC_CUSTOM_PLACEHOLDER;
    1078           57 :     var->vartype = PGC_STRING;
    1079              : 
    1080              :     /*
    1081              :      * The char* is allocated at the end of the struct since we have no
    1082              :      * 'static' place to point to.  Note that the current value, as well as
    1083              :      * the boot and reset values, start out NULL.
    1084              :      */
    1085           57 :     var->_string.variable = (char **) (var + 1);
    1086              : 
    1087           57 :     if (!add_guc_variable(var, elevel))
    1088              :     {
    1089            0 :         guc_free(unconstify(char *, var->name));
    1090            0 :         guc_free(var);
    1091            0 :         return NULL;
    1092              :     }
    1093              : 
    1094           57 :     return var;
    1095              : }
    1096              : 
    1097              : /*
    1098              :  * Look up option "name".  If it exists, return a pointer to its record.
    1099              :  * Otherwise, if create_placeholders is true and name is a valid-looking
    1100              :  * custom variable name, we'll create and return a placeholder record.
    1101              :  * Otherwise, if skip_errors is true, then we silently return NULL for
    1102              :  * an unrecognized or invalid name.  Otherwise, the error is reported at
    1103              :  * error level elevel (and we return NULL if that's less than ERROR).
    1104              :  *
    1105              :  * Note: internal errors, primarily out-of-memory, draw an elevel-level
    1106              :  * report and NULL return regardless of skip_errors.  Hence, callers must
    1107              :  * handle a NULL return whenever elevel < ERROR, but they should not need
    1108              :  * to emit any additional error message.  (In practice, internal errors
    1109              :  * can only happen when create_placeholders is true, so callers passing
    1110              :  * false need not think terribly hard about this.)
    1111              :  */
    1112              : struct config_generic *
    1113       729064 : find_option(const char *name, bool create_placeholders, bool skip_errors,
    1114              :             int elevel)
    1115              : {
    1116              :     GUCHashEntry *hentry;
    1117              : 
    1118              :     Assert(name);
    1119              : 
    1120              :     /* Look it up using the hash table. */
    1121       729064 :     hentry = (GUCHashEntry *) hash_search(guc_hashtab,
    1122              :                                           &name,
    1123              :                                           HASH_FIND,
    1124              :                                           NULL);
    1125       729064 :     if (hentry)
    1126       728866 :         return hentry->gucvar;
    1127              : 
    1128              :     /*
    1129              :      * See if the name is an obsolete name for a variable.  We assume that the
    1130              :      * set of supported old names is short enough that a brute-force search is
    1131              :      * the best way.
    1132              :      */
    1133          792 :     for (int i = 0; map_old_guc_names[i] != NULL; i += 2)
    1134              :     {
    1135          594 :         if (guc_name_compare(name, map_old_guc_names[i]) == 0)
    1136            0 :             return find_option(map_old_guc_names[i + 1], false,
    1137              :                                skip_errors, elevel);
    1138              :     }
    1139              : 
    1140          198 :     if (create_placeholders)
    1141              :     {
    1142              :         /*
    1143              :          * Check if the name is valid, and if so, add a placeholder.
    1144              :          */
    1145           99 :         if (assignable_custom_variable_name(name, skip_errors, elevel))
    1146           57 :             return add_placeholder_variable(name, elevel);
    1147              :         else
    1148            3 :             return NULL;        /* error message, if any, already emitted */
    1149              :     }
    1150              : 
    1151              :     /* Unknown name and we're not supposed to make a placeholder */
    1152           99 :     if (!skip_errors)
    1153           19 :         ereport(elevel,
    1154              :                 (errcode(ERRCODE_UNDEFINED_OBJECT),
    1155              :                  errmsg("unrecognized configuration parameter \"%s\"",
    1156              :                         name)));
    1157           80 :     return NULL;
    1158              : }
    1159              : 
    1160              : 
    1161              : /*
    1162              :  * comparator for qsorting an array of GUC pointers
    1163              :  */
    1164              : static int
    1165      6755606 : guc_var_compare(const void *a, const void *b)
    1166              : {
    1167      6755606 :     const struct config_generic *ca = *(const struct config_generic *const *) a;
    1168      6755606 :     const struct config_generic *cb = *(const struct config_generic *const *) b;
    1169              : 
    1170      6755606 :     return guc_name_compare(ca->name, cb->name);
    1171              : }
    1172              : 
    1173              : /*
    1174              :  * the bare comparison function for GUC names
    1175              :  */
    1176              : int
    1177      7864166 : guc_name_compare(const char *namea, const char *nameb)
    1178              : {
    1179              :     /*
    1180              :      * The temptation to use strcasecmp() here must be resisted, because the
    1181              :      * hash mapping has to remain stable across setlocale() calls. So, build
    1182              :      * our own with a simple ASCII-only downcasing.
    1183              :      */
    1184     32698427 :     while (*namea && *nameb)
    1185              :     {
    1186     31896041 :         char        cha = *namea++;
    1187     31896041 :         char        chb = *nameb++;
    1188              : 
    1189     31896041 :         if (cha >= 'A' && cha <= 'Z')
    1190       119749 :             cha += 'a' - 'A';
    1191     31896041 :         if (chb >= 'A' && chb <= 'Z')
    1192        51944 :             chb += 'a' - 'A';
    1193     31896041 :         if (cha != chb)
    1194      7061780 :             return cha - chb;
    1195              :     }
    1196       802386 :     if (*namea)
    1197        32764 :         return 1;               /* a is longer */
    1198       769622 :     if (*nameb)
    1199        40577 :         return -1;              /* b is longer */
    1200       729045 :     return 0;
    1201              : }
    1202              : 
    1203              : /*
    1204              :  * Hash function that's compatible with guc_name_compare
    1205              :  */
    1206              : static uint32
    1207      1240688 : guc_name_hash(const void *key, Size keysize)
    1208              : {
    1209      1240688 :     uint32      result = 0;
    1210      1240688 :     const char *name = *(const char *const *) key;
    1211              : 
    1212     21344090 :     while (*name)
    1213              :     {
    1214     20103402 :         char        ch = *name++;
    1215              : 
    1216              :         /* Case-fold in the same way as guc_name_compare */
    1217     20103402 :         if (ch >= 'A' && ch <= 'Z')
    1218        22290 :             ch += 'a' - 'A';
    1219              : 
    1220              :         /* Merge into hash ... not very bright, but it needn't be */
    1221     20103402 :         result = pg_rotate_left32(result, 5);
    1222     20103402 :         result ^= (uint32) ch;
    1223              :     }
    1224      1240688 :     return result;
    1225              : }
    1226              : 
    1227              : /*
    1228              :  * Dynahash match function to use in guc_hashtab
    1229              :  */
    1230              : static int
    1231       728921 : guc_name_match(const void *key1, const void *key2, Size keysize)
    1232              : {
    1233       728921 :     const char *name1 = *(const char *const *) key1;
    1234       728921 :     const char *name2 = *(const char *const *) key2;
    1235              : 
    1236       728921 :     return guc_name_compare(name1, name2);
    1237              : }
    1238              : 
    1239              : 
    1240              : /*
    1241              :  * Convert a GUC name to the form that should be used in pg_parameter_acl.
    1242              :  *
    1243              :  * We need to canonicalize entries since, for example, case should not be
    1244              :  * significant.  In addition, we apply the map_old_guc_names[] mapping so that
    1245              :  * any obsolete names will be converted when stored in a new PG version.
    1246              :  * Note however that this function does not verify legality of the name.
    1247              :  *
    1248              :  * The result is a palloc'd string.
    1249              :  */
    1250              : char *
    1251          176 : convert_GUC_name_for_parameter_acl(const char *name)
    1252              : {
    1253              :     char       *result;
    1254              : 
    1255              :     /* Apply old-GUC-name mapping. */
    1256          704 :     for (int i = 0; map_old_guc_names[i] != NULL; i += 2)
    1257              :     {
    1258          528 :         if (guc_name_compare(name, map_old_guc_names[i]) == 0)
    1259              :         {
    1260            0 :             name = map_old_guc_names[i + 1];
    1261            0 :             break;
    1262              :         }
    1263              :     }
    1264              : 
    1265              :     /* Apply case-folding that matches guc_name_compare(). */
    1266          176 :     result = pstrdup(name);
    1267         2864 :     for (char *ptr = result; *ptr != '\0'; ptr++)
    1268              :     {
    1269         2688 :         char        ch = *ptr;
    1270              : 
    1271         2688 :         if (ch >= 'A' && ch <= 'Z')
    1272              :         {
    1273            6 :             ch += 'a' - 'A';
    1274            6 :             *ptr = ch;
    1275              :         }
    1276              :     }
    1277              : 
    1278          176 :     return result;
    1279              : }
    1280              : 
    1281              : /*
    1282              :  * Check whether we should allow creation of a pg_parameter_acl entry
    1283              :  * for the given name.  (This can be applied either before or after
    1284              :  * canonicalizing it.)  Throws error if not.
    1285              :  */
    1286              : void
    1287           34 : check_GUC_name_for_parameter_acl(const char *name)
    1288              : {
    1289              :     /* OK if the GUC exists. */
    1290           34 :     if (find_option(name, false, true, DEBUG5) != NULL)
    1291           27 :         return;
    1292              :     /* Otherwise, it'd better be a valid custom GUC name. */
    1293            7 :     (void) assignable_custom_variable_name(name, false, ERROR);
    1294              : }
    1295              : 
    1296              : /*
    1297              :  * Routine in charge of checking various states of a GUC.
    1298              :  *
    1299              :  * This performs two sanity checks.  First, it checks that the initial
    1300              :  * value of a GUC is the same when declared and when loaded to prevent
    1301              :  * anybody looking at the C declarations of these GUCs from being fooled by
    1302              :  * mismatched values.  Second, it checks for incorrect flag combinations.
    1303              :  *
    1304              :  * The following validation rules apply for the values:
    1305              :  * bool - can be false, otherwise must be same as the boot_val
    1306              :  * int  - can be 0, otherwise must be same as the boot_val
    1307              :  * real - can be 0.0, otherwise must be same as the boot_val
    1308              :  * string - can be NULL, otherwise must be strcmp equal to the boot_val
    1309              :  * enum - must be same as the boot_val
    1310              :  */
    1311              : #ifdef USE_ASSERT_CHECKING
    1312              : static bool
    1313              : check_GUC_init(const struct config_generic *gconf)
    1314              : {
    1315              :     /* Checks on values */
    1316              :     switch (gconf->vartype)
    1317              :     {
    1318              :         case PGC_BOOL:
    1319              :             {
    1320              :                 const struct config_bool *conf = &gconf->_bool;
    1321              : 
    1322              :                 if (*conf->variable && !conf->boot_val)
    1323              :                 {
    1324              :                     elog(LOG, "GUC (PGC_BOOL) %s, boot_val=%d, C-var=%d",
    1325              :                          gconf->name, conf->boot_val, *conf->variable);
    1326              :                     return false;
    1327              :                 }
    1328              :                 break;
    1329              :             }
    1330              :         case PGC_INT:
    1331              :             {
    1332              :                 const struct config_int *conf = &gconf->_int;
    1333              : 
    1334              :                 if (*conf->variable != 0 && *conf->variable != conf->boot_val)
    1335              :                 {
    1336              :                     elog(LOG, "GUC (PGC_INT) %s, boot_val=%d, C-var=%d",
    1337              :                          gconf->name, conf->boot_val, *conf->variable);
    1338              :                     return false;
    1339              :                 }
    1340              :                 break;
    1341              :             }
    1342              :         case PGC_REAL:
    1343              :             {
    1344              :                 const struct config_real *conf = &gconf->_real;
    1345              : 
    1346              :                 if (*conf->variable != 0.0 && *conf->variable != conf->boot_val)
    1347              :                 {
    1348              :                     elog(LOG, "GUC (PGC_REAL) %s, boot_val=%g, C-var=%g",
    1349              :                          gconf->name, conf->boot_val, *conf->variable);
    1350              :                     return false;
    1351              :                 }
    1352              :                 break;
    1353              :             }
    1354              :         case PGC_STRING:
    1355              :             {
    1356              :                 const struct config_string *conf = &gconf->_string;
    1357              : 
    1358              :                 if (*conf->variable != NULL &&
    1359              :                     (conf->boot_val == NULL ||
    1360              :                      strcmp(*conf->variable, conf->boot_val) != 0))
    1361              :                 {
    1362              :                     elog(LOG, "GUC (PGC_STRING) %s, boot_val=%s, C-var=%s",
    1363              :                          gconf->name, conf->boot_val ? conf->boot_val : "<null>", *conf->variable);
    1364              :                     return false;
    1365              :                 }
    1366              :                 break;
    1367              :             }
    1368              :         case PGC_ENUM:
    1369              :             {
    1370              :                 const struct config_enum *conf = &gconf->_enum;
    1371              : 
    1372              :                 if (*conf->variable != conf->boot_val)
    1373              :                 {
    1374              :                     elog(LOG, "GUC (PGC_ENUM) %s, boot_val=%d, C-var=%d",
    1375              :                          gconf->name, conf->boot_val, *conf->variable);
    1376              :                     return false;
    1377              :                 }
    1378              :                 break;
    1379              :             }
    1380              :     }
    1381              : 
    1382              :     /* Flag combinations */
    1383              : 
    1384              :     /*
    1385              :      * GUC_NO_SHOW_ALL requires GUC_NOT_IN_SAMPLE, as a parameter not part of
    1386              :      * SHOW ALL should not be hidden in postgresql.conf.sample.
    1387              :      */
    1388              :     if ((gconf->flags & GUC_NO_SHOW_ALL) &&
    1389              :         !(gconf->flags & GUC_NOT_IN_SAMPLE))
    1390              :     {
    1391              :         elog(LOG, "GUC %s flags: NO_SHOW_ALL and !NOT_IN_SAMPLE",
    1392              :              gconf->name);
    1393              :         return false;
    1394              :     }
    1395              : 
    1396              :     return true;
    1397              : }
    1398              : #endif
    1399              : 
    1400              : /*
    1401              :  * Initialize GUC options during program startup.
    1402              :  *
    1403              :  * Note that we cannot read the config file yet, since we have not yet
    1404              :  * processed command-line switches.
    1405              :  */
    1406              : void
    1407         1192 : InitializeGUCOptions(void)
    1408              : {
    1409              :     HASH_SEQ_STATUS status;
    1410              :     GUCHashEntry *hentry;
    1411              : 
    1412              :     /*
    1413              :      * Before log_line_prefix could possibly receive a nonempty setting, make
    1414              :      * sure that timezone processing is minimally alive (see elog.c).
    1415              :      */
    1416         1192 :     pg_timezone_initialize();
    1417              : 
    1418              :     /*
    1419              :      * Create GUCMemoryContext and build hash table of all GUC variables.
    1420              :      */
    1421         1192 :     build_guc_variables();
    1422              : 
    1423              :     /*
    1424              :      * Load all variables with their compiled-in defaults, and initialize
    1425              :      * status fields as needed.
    1426              :      */
    1427         1192 :     hash_seq_init(&status, guc_hashtab);
    1428       493488 :     while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
    1429              :     {
    1430              :         /* Check mapping between initial and default value */
    1431              :         Assert(check_GUC_init(hentry->gucvar));
    1432              : 
    1433       492296 :         InitializeOneGUCOption(hentry->gucvar);
    1434              :     }
    1435              : 
    1436         1192 :     reporting_enabled = false;
    1437              : 
    1438              :     /*
    1439              :      * Prevent any attempt to override the transaction modes from
    1440              :      * non-interactive sources.
    1441              :      */
    1442         1192 :     SetConfigOption("transaction_isolation", "read committed",
    1443              :                     PGC_POSTMASTER, PGC_S_OVERRIDE);
    1444         1192 :     SetConfigOption("transaction_read_only", "no",
    1445              :                     PGC_POSTMASTER, PGC_S_OVERRIDE);
    1446         1192 :     SetConfigOption("transaction_deferrable", "no",
    1447              :                     PGC_POSTMASTER, PGC_S_OVERRIDE);
    1448              : 
    1449              :     /*
    1450              :      * For historical reasons, some GUC parameters can receive defaults from
    1451              :      * environment variables.  Process those settings.
    1452              :      */
    1453         1192 :     InitializeGUCOptionsFromEnvironment();
    1454         1192 : }
    1455              : 
    1456              : /*
    1457              :  * Assign any GUC values that can come from the server's environment.
    1458              :  *
    1459              :  * This is called from InitializeGUCOptions, and also from ProcessConfigFile
    1460              :  * to deal with the possibility that a setting has been removed from
    1461              :  * postgresql.conf and should now get a value from the environment.
    1462              :  * (The latter is a kludge that should probably go away someday; if so,
    1463              :  * fold this back into InitializeGUCOptions.)
    1464              :  */
    1465              : static void
    1466         1998 : InitializeGUCOptionsFromEnvironment(void)
    1467              : {
    1468              :     char       *env;
    1469              :     ssize_t     stack_rlimit;
    1470              : 
    1471         1998 :     env = getenv("PGPORT");
    1472         1998 :     if (env != NULL)
    1473         1813 :         SetConfigOption("port", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
    1474              : 
    1475         1998 :     env = getenv("PGDATESTYLE");
    1476         1998 :     if (env != NULL)
    1477          118 :         SetConfigOption("datestyle", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
    1478              : 
    1479         1998 :     env = getenv("PGCLIENTENCODING");
    1480         1998 :     if (env != NULL)
    1481           15 :         SetConfigOption("client_encoding", env, PGC_POSTMASTER, PGC_S_ENV_VAR);
    1482              : 
    1483              :     /*
    1484              :      * rlimit isn't exactly an "environment variable", but it behaves about
    1485              :      * the same.  If we can identify the platform stack depth rlimit, increase
    1486              :      * default stack depth setting up to whatever is safe (but at most 2MB).
    1487              :      * Report the value's source as PGC_S_DYNAMIC_DEFAULT if it's 2MB, or as
    1488              :      * PGC_S_ENV_VAR if it's reflecting the rlimit limit.
    1489              :      */
    1490         1998 :     stack_rlimit = get_stack_depth_rlimit();
    1491         1998 :     if (stack_rlimit > 0)
    1492              :     {
    1493         1998 :         ssize_t     new_limit = (stack_rlimit - STACK_DEPTH_SLOP) / 1024;
    1494              : 
    1495         1998 :         if (new_limit > 100)
    1496              :         {
    1497              :             GucSource   source;
    1498              :             char        limbuf[16];
    1499              : 
    1500         1998 :             if (new_limit < 2048)
    1501            0 :                 source = PGC_S_ENV_VAR;
    1502              :             else
    1503              :             {
    1504         1998 :                 new_limit = 2048;
    1505         1998 :                 source = PGC_S_DYNAMIC_DEFAULT;
    1506              :             }
    1507         1998 :             snprintf(limbuf, sizeof(limbuf), "%zd", new_limit);
    1508         1998 :             SetConfigOption("max_stack_depth", limbuf,
    1509              :                             PGC_POSTMASTER, source);
    1510              :         }
    1511              :     }
    1512         1998 : }
    1513              : 
    1514              : /*
    1515              :  * Initialize one GUC option variable to its compiled-in default.
    1516              :  *
    1517              :  * Note: the reason for calling check_hooks is not that we think the boot_val
    1518              :  * might fail, but that the hooks might wish to compute an "extra" struct.
    1519              :  */
    1520              : static void
    1521       538543 : InitializeOneGUCOption(struct config_generic *gconf)
    1522              : {
    1523       538543 :     void       *extra = NULL;
    1524              : 
    1525       538543 :     gconf->status = 0;
    1526       538543 :     gconf->source = PGC_S_DEFAULT;
    1527       538543 :     gconf->reset_source = PGC_S_DEFAULT;
    1528       538543 :     gconf->scontext = PGC_INTERNAL;
    1529       538543 :     gconf->reset_scontext = PGC_INTERNAL;
    1530       538543 :     gconf->srole = BOOTSTRAP_SUPERUSERID;
    1531       538543 :     gconf->reset_srole = BOOTSTRAP_SUPERUSERID;
    1532       538543 :     gconf->stack = NULL;
    1533       538543 :     gconf->extra = NULL;
    1534       538543 :     gconf->last_reported = NULL;
    1535       538543 :     gconf->sourcefile = NULL;
    1536       538543 :     gconf->sourceline = 0;
    1537              : 
    1538       538543 :     switch (gconf->vartype)
    1539              :     {
    1540       154796 :         case PGC_BOOL:
    1541              :             {
    1542       154796 :                 struct config_bool *conf = &gconf->_bool;
    1543       154796 :                 bool        newval = conf->boot_val;
    1544              : 
    1545       154796 :                 if (!call_bool_check_hook(gconf, &newval, &extra,
    1546              :                                           PGC_S_DEFAULT, LOG))
    1547            0 :                     elog(FATAL, "failed to initialize %s to %d",
    1548              :                          gconf->name, (int) newval);
    1549       154796 :                 if (conf->assign_hook)
    1550            0 :                     conf->assign_hook(newval, extra);
    1551       154796 :                 *conf->variable = conf->reset_val = newval;
    1552       154796 :                 break;
    1553              :             }
    1554       185116 :         case PGC_INT:
    1555              :             {
    1556       185116 :                 struct config_int *conf = &gconf->_int;
    1557       185116 :                 int         newval = conf->boot_val;
    1558              : 
    1559              :                 Assert(newval >= conf->min);
    1560              :                 Assert(newval <= conf->max);
    1561       185116 :                 if (!call_int_check_hook(gconf, &newval, &extra,
    1562              :                                          PGC_S_DEFAULT, LOG))
    1563            0 :                     elog(FATAL, "failed to initialize %s to %d",
    1564              :                          gconf->name, newval);
    1565       185116 :                 if (conf->assign_hook)
    1566        14888 :                     conf->assign_hook(newval, extra);
    1567       185116 :                 *conf->variable = conf->reset_val = newval;
    1568       185116 :                 break;
    1569              :             }
    1570        32210 :         case PGC_REAL:
    1571              :             {
    1572        32210 :                 struct config_real *conf = &gconf->_real;
    1573        32210 :                 double      newval = conf->boot_val;
    1574              : 
    1575              :                 Assert(newval >= conf->min);
    1576              :                 Assert(newval <= conf->max);
    1577        32210 :                 if (!call_real_check_hook(gconf, &newval, &extra,
    1578              :                                           PGC_S_DEFAULT, LOG))
    1579            0 :                     elog(FATAL, "failed to initialize %s to %g",
    1580              :                          gconf->name, newval);
    1581        32210 :                 if (conf->assign_hook)
    1582         2384 :                     conf->assign_hook(newval, extra);
    1583        32210 :                 *conf->variable = conf->reset_val = newval;
    1584        32210 :                 break;
    1585              :             }
    1586       111233 :         case PGC_STRING:
    1587              :             {
    1588       111233 :                 struct config_string *conf = &gconf->_string;
    1589              :                 char       *newval;
    1590              : 
    1591              :                 /* non-NULL boot_val must always get strdup'd */
    1592       111233 :                 if (conf->boot_val != NULL)
    1593       101267 :                     newval = guc_strdup(FATAL, conf->boot_val);
    1594              :                 else
    1595         9966 :                     newval = NULL;
    1596              : 
    1597       111233 :                 if (!call_string_check_hook(gconf, &newval, &extra,
    1598              :                                             PGC_S_DEFAULT, LOG))
    1599            0 :                     elog(FATAL, "failed to initialize %s to \"%s\"",
    1600              :                          gconf->name, newval ? newval : "");
    1601       111233 :                 if (conf->assign_hook)
    1602        57144 :                     conf->assign_hook(newval, extra);
    1603       111233 :                 *conf->variable = conf->reset_val = newval;
    1604       111233 :                 break;
    1605              :             }
    1606        55188 :         case PGC_ENUM:
    1607              :             {
    1608        55188 :                 struct config_enum *conf = &gconf->_enum;
    1609        55188 :                 int         newval = conf->boot_val;
    1610              : 
    1611        55188 :                 if (!call_enum_check_hook(gconf, &newval, &extra,
    1612              :                                           PGC_S_DEFAULT, LOG))
    1613            0 :                     elog(FATAL, "failed to initialize %s to %d",
    1614              :                          gconf->name, newval);
    1615        55188 :                 if (conf->assign_hook)
    1616         8346 :                     conf->assign_hook(newval, extra);
    1617        55188 :                 *conf->variable = conf->reset_val = newval;
    1618        55188 :                 break;
    1619              :             }
    1620              :     }
    1621              : 
    1622       538543 :     gconf->extra = gconf->reset_extra = extra;
    1623       538543 : }
    1624              : 
    1625              : /*
    1626              :  * Summarily remove a GUC variable from any linked lists it's in.
    1627              :  *
    1628              :  * We use this in cases where the variable is about to be deleted or reset.
    1629              :  * These aren't common operations, so it's okay if this is a bit slow.
    1630              :  */
    1631              : static void
    1632        36643 : RemoveGUCFromLists(struct config_generic *gconf)
    1633              : {
    1634        36643 :     if (gconf->source != PGC_S_DEFAULT)
    1635        36642 :         dlist_delete(&gconf->nondef_link);
    1636        36643 :     if (gconf->stack != NULL)
    1637            0 :         slist_delete(&guc_stack_list, &gconf->stack_link);
    1638        36643 :     if (gconf->status & GUC_NEEDS_REPORT)
    1639         4452 :         slist_delete(&guc_report_list, &gconf->report_link);
    1640        36643 : }
    1641              : 
    1642              : 
    1643              : /*
    1644              :  * Select the configuration files and data directory to be used, and
    1645              :  * do the initial read of postgresql.conf.
    1646              :  *
    1647              :  * This is called after processing command-line switches.
    1648              :  *      userDoption is the -D switch value if any (NULL if unspecified).
    1649              :  *      progname is just for use in error messages.
    1650              :  *
    1651              :  * Returns true on success; on failure, prints a suitable error message
    1652              :  * to stderr and returns false.
    1653              :  */
    1654              : bool
    1655         1166 : SelectConfigFiles(const char *userDoption, const char *progname)
    1656              : {
    1657              :     char       *configdir;
    1658              :     char       *fname;
    1659              :     bool        fname_is_malloced;
    1660              :     struct stat stat_buf;
    1661              :     struct config_generic *data_directory_rec;
    1662              : 
    1663              :     /* configdir is -D option, or $PGDATA if no -D */
    1664         1166 :     if (userDoption)
    1665          961 :         configdir = make_absolute_path(userDoption);
    1666              :     else
    1667          205 :         configdir = make_absolute_path(getenv("PGDATA"));
    1668              : 
    1669         1166 :     if (configdir && stat(configdir, &stat_buf) != 0)
    1670              :     {
    1671            0 :         write_stderr("%s: could not access directory \"%s\": %m\n",
    1672              :                      progname,
    1673              :                      configdir);
    1674            0 :         if (errno == ENOENT)
    1675            0 :             write_stderr("Run initdb or pg_basebackup to initialize a PostgreSQL data directory.\n");
    1676            0 :         goto fail;
    1677              :     }
    1678              : 
    1679              :     /*
    1680              :      * Find the configuration file: if config_file was specified on the
    1681              :      * command line, use it, else use configdir/postgresql.conf.  In any case
    1682              :      * ensure the result is an absolute path, so that it will be interpreted
    1683              :      * the same way by future backends.
    1684              :      */
    1685         1166 :     if (ConfigFileName)
    1686              :     {
    1687           10 :         fname = make_absolute_path(ConfigFileName);
    1688           10 :         fname_is_malloced = true;
    1689              :     }
    1690         1156 :     else if (configdir)
    1691              :     {
    1692         1156 :         fname = guc_malloc(FATAL,
    1693         1156 :                            strlen(configdir) + strlen(CONFIG_FILENAME) + 2);
    1694         1156 :         sprintf(fname, "%s/%s", configdir, CONFIG_FILENAME);
    1695         1156 :         fname_is_malloced = false;
    1696              :     }
    1697              :     else
    1698              :     {
    1699            0 :         write_stderr("%s does not know where to find the server configuration file.\n"
    1700              :                      "You must specify the --config-file or -D invocation "
    1701              :                      "option or set the PGDATA environment variable.\n",
    1702              :                      progname);
    1703            0 :         goto fail;
    1704              :     }
    1705              : 
    1706              :     /*
    1707              :      * Set the ConfigFileName GUC variable to its final value, ensuring that
    1708              :      * it can't be overridden later.
    1709              :      */
    1710         1166 :     SetConfigOption("config_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
    1711              : 
    1712         1166 :     if (fname_is_malloced)
    1713           10 :         free(fname);
    1714              :     else
    1715         1156 :         guc_free(fname);
    1716              : 
    1717              :     /*
    1718              :      * Now read the config file for the first time.
    1719              :      */
    1720         1166 :     if (stat(ConfigFileName, &stat_buf) != 0)
    1721              :     {
    1722            0 :         write_stderr("%s: could not access the server configuration file \"%s\": %m\n",
    1723              :                      progname, ConfigFileName);
    1724            0 :         goto fail;
    1725              :     }
    1726              : 
    1727              :     /*
    1728              :      * Read the configuration file for the first time.  This time only the
    1729              :      * data_directory parameter is picked up to determine the data directory,
    1730              :      * so that we can read the PG_AUTOCONF_FILENAME file next time.
    1731              :      */
    1732         1166 :     ProcessConfigFile(PGC_POSTMASTER);
    1733              : 
    1734              :     /*
    1735              :      * If the data_directory GUC variable has been set, use that as DataDir;
    1736              :      * otherwise use configdir if set; else punt.
    1737              :      *
    1738              :      * Note: SetDataDir will copy and absolute-ize its argument, so we don't
    1739              :      * have to.
    1740              :      */
    1741              :     data_directory_rec =
    1742         1166 :         find_option("data_directory", false, false, PANIC);
    1743         1166 :     if (*data_directory_rec->_string.variable)
    1744            0 :         SetDataDir(*data_directory_rec->_string.variable);
    1745         1166 :     else if (configdir)
    1746         1166 :         SetDataDir(configdir);
    1747              :     else
    1748              :     {
    1749            0 :         write_stderr("%s does not know where to find the database system data.\n"
    1750              :                      "This can be specified as \"data_directory\" in \"%s\", "
    1751              :                      "or by the -D invocation option, or by the "
    1752              :                      "PGDATA environment variable.\n",
    1753              :                      progname, ConfigFileName);
    1754            0 :         goto fail;
    1755              :     }
    1756              : 
    1757              :     /*
    1758              :      * Reflect the final DataDir value back into the data_directory GUC var.
    1759              :      * (If you are wondering why we don't just make them a single variable,
    1760              :      * it's because the EXEC_BACKEND case needs DataDir to be transmitted to
    1761              :      * child backends specially.  XXX is that still true?  Given that we now
    1762              :      * chdir to DataDir, EXEC_BACKEND can read the config file without knowing
    1763              :      * DataDir in advance.)
    1764              :      */
    1765         1166 :     SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
    1766              : 
    1767              :     /*
    1768              :      * Now read the config file a second time, allowing any settings in the
    1769              :      * PG_AUTOCONF_FILENAME file to take effect.  (This is pretty ugly, but
    1770              :      * since we have to determine the DataDir before we can find the autoconf
    1771              :      * file, the alternatives seem worse.)
    1772              :      */
    1773         1166 :     ProcessConfigFile(PGC_POSTMASTER);
    1774              : 
    1775              :     /*
    1776              :      * If timezone_abbreviations wasn't set in the configuration file, install
    1777              :      * the default value.  We do it this way because we can't safely install a
    1778              :      * "real" value until my_exec_path is set, which may not have happened
    1779              :      * when InitializeGUCOptions runs, so the bootstrap default value cannot
    1780              :      * be the real desired default.
    1781              :      */
    1782         1164 :     pg_timezone_abbrev_initialize();
    1783              : 
    1784              :     /*
    1785              :      * Figure out where pg_hba.conf is, and make sure the path is absolute.
    1786              :      */
    1787         1164 :     if (HbaFileName)
    1788              :     {
    1789            1 :         fname = make_absolute_path(HbaFileName);
    1790            1 :         fname_is_malloced = true;
    1791              :     }
    1792         1163 :     else if (configdir)
    1793              :     {
    1794         1163 :         fname = guc_malloc(FATAL,
    1795         1163 :                            strlen(configdir) + strlen(HBA_FILENAME) + 2);
    1796         1163 :         sprintf(fname, "%s/%s", configdir, HBA_FILENAME);
    1797         1163 :         fname_is_malloced = false;
    1798              :     }
    1799              :     else
    1800              :     {
    1801            0 :         write_stderr("%s does not know where to find the \"hba\" configuration file.\n"
    1802              :                      "This can be specified as \"hba_file\" in \"%s\", "
    1803              :                      "or by the -D invocation option, or by the "
    1804              :                      "PGDATA environment variable.\n",
    1805              :                      progname, ConfigFileName);
    1806            0 :         goto fail;
    1807              :     }
    1808         1164 :     SetConfigOption("hba_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
    1809              : 
    1810         1164 :     if (fname_is_malloced)
    1811            1 :         free(fname);
    1812              :     else
    1813         1163 :         guc_free(fname);
    1814              : 
    1815              :     /*
    1816              :      * Likewise for pg_ident.conf.
    1817              :      */
    1818         1164 :     if (IdentFileName)
    1819              :     {
    1820            1 :         fname = make_absolute_path(IdentFileName);
    1821            1 :         fname_is_malloced = true;
    1822              :     }
    1823         1163 :     else if (configdir)
    1824              :     {
    1825         1163 :         fname = guc_malloc(FATAL,
    1826         1163 :                            strlen(configdir) + strlen(IDENT_FILENAME) + 2);
    1827         1163 :         sprintf(fname, "%s/%s", configdir, IDENT_FILENAME);
    1828         1163 :         fname_is_malloced = false;
    1829              :     }
    1830              :     else
    1831              :     {
    1832            0 :         write_stderr("%s does not know where to find the \"ident\" configuration file.\n"
    1833              :                      "This can be specified as \"ident_file\" in \"%s\", "
    1834              :                      "or by the -D invocation option, or by the "
    1835              :                      "PGDATA environment variable.\n",
    1836              :                      progname, ConfigFileName);
    1837            0 :         goto fail;
    1838              :     }
    1839         1164 :     SetConfigOption("ident_file", fname, PGC_POSTMASTER, PGC_S_OVERRIDE);
    1840              : 
    1841         1164 :     if (fname_is_malloced)
    1842            1 :         free(fname);
    1843              :     else
    1844         1163 :         guc_free(fname);
    1845              : 
    1846         1164 :     free(configdir);
    1847              : 
    1848         1164 :     return true;
    1849              : 
    1850            0 : fail:
    1851            0 :     free(configdir);
    1852              : 
    1853            0 :     return false;
    1854              : }
    1855              : 
    1856              : /*
    1857              :  * pg_timezone_abbrev_initialize --- set default value if not done already
    1858              :  *
    1859              :  * This is called after initial loading of postgresql.conf.  If no
    1860              :  * timezone_abbreviations setting was found therein, select default.
    1861              :  * If a non-default value is already installed, nothing will happen.
    1862              :  *
    1863              :  * This can also be called from ProcessConfigFile to establish the default
    1864              :  * value after a postgresql.conf entry for it is removed.
    1865              :  */
    1866              : static void
    1867         1970 : pg_timezone_abbrev_initialize(void)
    1868              : {
    1869         1970 :     SetConfigOption("timezone_abbreviations", "Default",
    1870              :                     PGC_POSTMASTER, PGC_S_DYNAMIC_DEFAULT);
    1871         1970 : }
    1872              : 
    1873              : 
    1874              : /*
    1875              :  * Reset all options to their saved default values (implements RESET ALL)
    1876              :  */
    1877              : void
    1878            9 : ResetAllOptions(void)
    1879              : {
    1880              :     dlist_mutable_iter iter;
    1881              : 
    1882              :     /* We need only consider GUCs not already at PGC_S_DEFAULT */
    1883          518 :     dlist_foreach_modify(iter, &guc_nondef_list)
    1884              :     {
    1885          509 :         struct config_generic *gconf = dlist_container(struct config_generic,
    1886              :                                                        nondef_link, iter.cur);
    1887              : 
    1888              :         /* Don't reset non-SET-able values */
    1889          509 :         if (gconf->context != PGC_SUSET &&
    1890          470 :             gconf->context != PGC_USERSET)
    1891          307 :             continue;
    1892              :         /* Don't reset if special exclusion from RESET ALL */
    1893          202 :         if (gconf->flags & GUC_NO_RESET_ALL)
    1894           45 :             continue;
    1895              :         /* No need to reset if wasn't SET */
    1896          157 :         if (gconf->source <= PGC_S_OVERRIDE)
    1897          137 :             continue;
    1898              : 
    1899              :         /* Save old value to support transaction abort */
    1900           20 :         push_old_value(gconf, GUC_ACTION_SET);
    1901              : 
    1902           20 :         switch (gconf->vartype)
    1903              :         {
    1904           10 :             case PGC_BOOL:
    1905              :                 {
    1906           10 :                     struct config_bool *conf = &gconf->_bool;
    1907              : 
    1908           10 :                     if (conf->assign_hook)
    1909            0 :                         conf->assign_hook(conf->reset_val,
    1910              :                                           gconf->reset_extra);
    1911           10 :                     *conf->variable = conf->reset_val;
    1912           10 :                     set_extra_field(gconf, &gconf->extra,
    1913              :                                     gconf->reset_extra);
    1914           10 :                     break;
    1915              :                 }
    1916            1 :             case PGC_INT:
    1917              :                 {
    1918            1 :                     struct config_int *conf = &gconf->_int;
    1919              : 
    1920            1 :                     if (conf->assign_hook)
    1921            0 :                         conf->assign_hook(conf->reset_val,
    1922              :                                           gconf->reset_extra);
    1923            1 :                     *conf->variable = conf->reset_val;
    1924            1 :                     set_extra_field(gconf, &gconf->extra,
    1925              :                                     gconf->reset_extra);
    1926            1 :                     break;
    1927              :                 }
    1928            3 :             case PGC_REAL:
    1929              :                 {
    1930            3 :                     struct config_real *conf = &gconf->_real;
    1931              : 
    1932            3 :                     if (conf->assign_hook)
    1933            0 :                         conf->assign_hook(conf->reset_val,
    1934              :                                           gconf->reset_extra);
    1935            3 :                     *conf->variable = conf->reset_val;
    1936            3 :                     set_extra_field(gconf, &gconf->extra,
    1937              :                                     gconf->reset_extra);
    1938            3 :                     break;
    1939              :                 }
    1940            5 :             case PGC_STRING:
    1941              :                 {
    1942            5 :                     struct config_string *conf = &gconf->_string;
    1943              : 
    1944            5 :                     if (conf->assign_hook)
    1945            2 :                         conf->assign_hook(conf->reset_val,
    1946              :                                           gconf->reset_extra);
    1947            5 :                     set_string_field(gconf, conf->variable, conf->reset_val);
    1948            5 :                     set_extra_field(gconf, &gconf->extra,
    1949              :                                     gconf->reset_extra);
    1950            5 :                     break;
    1951              :                 }
    1952            1 :             case PGC_ENUM:
    1953              :                 {
    1954            1 :                     struct config_enum *conf = &gconf->_enum;
    1955              : 
    1956            1 :                     if (conf->assign_hook)
    1957            0 :                         conf->assign_hook(conf->reset_val,
    1958              :                                           gconf->reset_extra);
    1959            1 :                     *conf->variable = conf->reset_val;
    1960            1 :                     set_extra_field(gconf, &gconf->extra,
    1961              :                                     gconf->reset_extra);
    1962            1 :                     break;
    1963              :                 }
    1964              :         }
    1965              : 
    1966           20 :         set_guc_source(gconf, gconf->reset_source);
    1967           20 :         gconf->scontext = gconf->reset_scontext;
    1968           20 :         gconf->srole = gconf->reset_srole;
    1969              : 
    1970           20 :         if ((gconf->flags & GUC_REPORT) && !(gconf->status & GUC_NEEDS_REPORT))
    1971              :         {
    1972            3 :             gconf->status |= GUC_NEEDS_REPORT;
    1973            3 :             slist_push_head(&guc_report_list, &gconf->report_link);
    1974              :         }
    1975              :     }
    1976            9 : }
    1977              : 
    1978              : 
    1979              : /*
    1980              :  * Apply a change to a GUC variable's "source" field.
    1981              :  *
    1982              :  * Use this rather than just assigning, to ensure that the variable's
    1983              :  * membership in guc_nondef_list is updated correctly.
    1984              :  */
    1985              : static void
    1986       749194 : set_guc_source(struct config_generic *gconf, GucSource newsource)
    1987              : {
    1988              :     /* Adjust nondef list membership if appropriate for change */
    1989       749194 :     if (gconf->source == PGC_S_DEFAULT)
    1990              :     {
    1991       293998 :         if (newsource != PGC_S_DEFAULT)
    1992       293374 :             dlist_push_tail(&guc_nondef_list, &gconf->nondef_link);
    1993              :     }
    1994              :     else
    1995              :     {
    1996       455196 :         if (newsource == PGC_S_DEFAULT)
    1997        53356 :             dlist_delete(&gconf->nondef_link);
    1998              :     }
    1999              :     /* Now update the source field */
    2000       749194 :     gconf->source = newsource;
    2001       749194 : }
    2002              : 
    2003              : 
    2004              : /*
    2005              :  * push_old_value
    2006              :  *      Push previous state during transactional assignment to a GUC variable.
    2007              :  */
    2008              : static void
    2009       247156 : push_old_value(struct config_generic *gconf, GucAction action)
    2010              : {
    2011              :     GucStack   *stack;
    2012              : 
    2013              :     /* If we're not inside a nest level, do nothing */
    2014       247156 :     if (GUCNestLevel == 0)
    2015            0 :         return;
    2016              : 
    2017              :     /* Do we already have a stack entry of the current nest level? */
    2018       247156 :     stack = gconf->stack;
    2019       247156 :     if (stack && stack->nest_level >= GUCNestLevel)
    2020              :     {
    2021              :         /* Yes, so adjust its state if necessary */
    2022              :         Assert(stack->nest_level == GUCNestLevel);
    2023         5653 :         switch (action)
    2024              :         {
    2025         5567 :             case GUC_ACTION_SET:
    2026              :                 /* SET overrides any prior action at same nest level */
    2027         5567 :                 if (stack->state == GUC_SET_LOCAL)
    2028              :                 {
    2029              :                     /* must discard old masked value */
    2030            0 :                     discard_stack_value(gconf, &stack->masked);
    2031              :                 }
    2032         5567 :                 stack->state = GUC_SET;
    2033         5567 :                 break;
    2034           86 :             case GUC_ACTION_LOCAL:
    2035           86 :                 if (stack->state == GUC_SET)
    2036              :                 {
    2037              :                     /* SET followed by SET LOCAL, remember SET's value */
    2038            6 :                     stack->masked_scontext = gconf->scontext;
    2039            6 :                     stack->masked_srole = gconf->srole;
    2040            6 :                     set_stack_value(gconf, &stack->masked);
    2041            6 :                     stack->state = GUC_SET_LOCAL;
    2042              :                 }
    2043              :                 /* in all other cases, no change to stack entry */
    2044           86 :                 break;
    2045            0 :             case GUC_ACTION_SAVE:
    2046              :                 /* Could only have a prior SAVE of same variable */
    2047              :                 Assert(stack->state == GUC_SAVE);
    2048            0 :                 break;
    2049              :         }
    2050         5653 :         return;
    2051              :     }
    2052              : 
    2053              :     /*
    2054              :      * Push a new stack entry
    2055              :      *
    2056              :      * We keep all the stack entries in TopTransactionContext for simplicity.
    2057              :      */
    2058       241503 :     stack = (GucStack *) MemoryContextAllocZero(TopTransactionContext,
    2059              :                                                 sizeof(GucStack));
    2060              : 
    2061       241502 :     stack->prev = gconf->stack;
    2062       241502 :     stack->nest_level = GUCNestLevel;
    2063       241502 :     switch (action)
    2064              :     {
    2065        31829 :         case GUC_ACTION_SET:
    2066        31829 :             stack->state = GUC_SET;
    2067        31829 :             break;
    2068         4502 :         case GUC_ACTION_LOCAL:
    2069         4502 :             stack->state = GUC_LOCAL;
    2070         4502 :             break;
    2071       205171 :         case GUC_ACTION_SAVE:
    2072       205171 :             stack->state = GUC_SAVE;
    2073       205171 :             break;
    2074              :     }
    2075       241502 :     stack->source = gconf->source;
    2076       241502 :     stack->scontext = gconf->scontext;
    2077       241502 :     stack->srole = gconf->srole;
    2078       241502 :     set_stack_value(gconf, &stack->prior);
    2079              : 
    2080       241502 :     if (gconf->stack == NULL)
    2081       224913 :         slist_push_head(&guc_stack_list, &gconf->stack_link);
    2082       241502 :     gconf->stack = stack;
    2083              : }
    2084              : 
    2085              : 
    2086              : /*
    2087              :  * Do GUC processing at main transaction start.
    2088              :  */
    2089              : void
    2090       558000 : AtStart_GUC(void)
    2091              : {
    2092              :     /*
    2093              :      * The nest level should be 0 between transactions; if it isn't, somebody
    2094              :      * didn't call AtEOXact_GUC, or called it with the wrong nestLevel.  We
    2095              :      * throw a warning but make no other effort to clean up.
    2096              :      */
    2097       558000 :     if (GUCNestLevel != 0)
    2098            0 :         elog(WARNING, "GUC nest level = %d at transaction start",
    2099              :              GUCNestLevel);
    2100       558000 :     GUCNestLevel = 1;
    2101       558000 : }
    2102              : 
    2103              : /*
    2104              :  * Enter a new nesting level for GUC values.  This is called at subtransaction
    2105              :  * start, and when entering a function that has proconfig settings, and in
    2106              :  * some other places where we want to set GUC variables transiently.
    2107              :  * NOTE we must not risk error here, else subtransaction start will be unhappy.
    2108              :  */
    2109              : int
    2110       236207 : NewGUCNestLevel(void)
    2111              : {
    2112       236207 :     return ++GUCNestLevel;
    2113              : }
    2114              : 
    2115              : /*
    2116              :  * Set search_path to a fixed value for maintenance operations. No effect
    2117              :  * during bootstrap, when the search_path is already set to a fixed value and
    2118              :  * cannot be changed.
    2119              :  */
    2120              : void
    2121       215545 : RestrictSearchPath(void)
    2122              : {
    2123       215545 :     if (!IsBootstrapProcessingMode())
    2124       184333 :         set_config_option("search_path", GUC_SAFE_SEARCH_PATH, PGC_USERSET,
    2125              :                           PGC_S_SESSION, GUC_ACTION_SAVE, true, 0, false);
    2126       215545 : }
    2127              : 
    2128              : /*
    2129              :  * Do GUC processing at transaction or subtransaction commit or abort, or
    2130              :  * when exiting a function that has proconfig settings, or when undoing a
    2131              :  * transient assignment to some GUC variables.  (The name is thus a bit of
    2132              :  * a misnomer; perhaps it should be ExitGUCNestLevel or some such.)
    2133              :  * During abort, we discard all GUC settings that were applied at nesting
    2134              :  * levels >= nestLevel.  nestLevel == 1 corresponds to the main transaction.
    2135              :  */
    2136              : void
    2137       793415 : AtEOXact_GUC(bool isCommit, int nestLevel)
    2138              : {
    2139              :     slist_mutable_iter iter;
    2140              : 
    2141              :     /*
    2142              :      * Note: it's possible to get here with GUCNestLevel == nestLevel-1 during
    2143              :      * abort, if there is a failure during transaction start before
    2144              :      * AtStart_GUC is called.
    2145              :      */
    2146              :     Assert(nestLevel > 0 &&
    2147              :            (nestLevel <= GUCNestLevel ||
    2148              :             (nestLevel == GUCNestLevel + 1 && !isCommit)));
    2149              : 
    2150              :     /* We need only process GUCs having nonempty stacks */
    2151      1038086 :     slist_foreach_modify(iter, &guc_stack_list)
    2152              :     {
    2153       244671 :         struct config_generic *gconf = slist_container(struct config_generic,
    2154              :                                                        stack_link, iter.cur);
    2155              :         GucStack   *stack;
    2156              : 
    2157              :         /*
    2158              :          * Process and pop each stack entry within the nest level. To simplify
    2159              :          * fmgr_security_definer() and other places that use GUC_ACTION_SAVE,
    2160              :          * we allow failure exit from code that uses a local nest level to be
    2161              :          * recovered at the surrounding transaction or subtransaction abort;
    2162              :          * so there could be more than one stack entry to pop.
    2163              :          */
    2164       486190 :         while ((stack = gconf->stack) != NULL &&
    2165       261278 :                stack->nest_level >= nestLevel)
    2166              :         {
    2167       241519 :             GucStack   *prev = stack->prev;
    2168       241519 :             bool        restorePrior = false;
    2169       241519 :             bool        restoreMasked = false;
    2170              :             bool        changed;
    2171              : 
    2172              :             /*
    2173              :              * In this next bit, if we don't set either restorePrior or
    2174              :              * restoreMasked, we must "discard" any unwanted fields of the
    2175              :              * stack entries to avoid leaking memory.  If we do set one of
    2176              :              * those flags, unused fields will be cleaned up after restoring.
    2177              :              */
    2178       241519 :             if (!isCommit)      /* if abort, always restore prior value */
    2179       187047 :                 restorePrior = true;
    2180        54472 :             else if (stack->state == GUC_SAVE)
    2181        20373 :                 restorePrior = true;
    2182        34099 :             else if (stack->nest_level == 1)
    2183              :             {
    2184              :                 /* transaction commit */
    2185        34078 :                 if (stack->state == GUC_SET_LOCAL)
    2186            6 :                     restoreMasked = true;
    2187        34072 :                 else if (stack->state == GUC_SET)
    2188              :                 {
    2189              :                     /* we keep the current active value */
    2190        30556 :                     discard_stack_value(gconf, &stack->prior);
    2191              :                 }
    2192              :                 else            /* must be GUC_LOCAL */
    2193         3516 :                     restorePrior = true;
    2194              :             }
    2195           21 :             else if (prev == NULL ||
    2196            6 :                      prev->nest_level < stack->nest_level - 1)
    2197              :             {
    2198              :                 /* decrement entry's level and do not pop it */
    2199           18 :                 stack->nest_level--;
    2200           18 :                 continue;
    2201              :             }
    2202              :             else
    2203              :             {
    2204              :                 /*
    2205              :                  * We have to merge this stack entry into prev. See README for
    2206              :                  * discussion of this bit.
    2207              :                  */
    2208            3 :                 switch (stack->state)
    2209              :                 {
    2210            0 :                     case GUC_SAVE:
    2211              :                         Assert(false);  /* can't get here */
    2212            0 :                         break;
    2213              : 
    2214            3 :                     case GUC_SET:
    2215              :                         /* next level always becomes SET */
    2216            3 :                         discard_stack_value(gconf, &stack->prior);
    2217            3 :                         if (prev->state == GUC_SET_LOCAL)
    2218            0 :                             discard_stack_value(gconf, &prev->masked);
    2219            3 :                         prev->state = GUC_SET;
    2220            3 :                         break;
    2221              : 
    2222            0 :                     case GUC_LOCAL:
    2223            0 :                         if (prev->state == GUC_SET)
    2224              :                         {
    2225              :                             /* LOCAL migrates down */
    2226            0 :                             prev->masked_scontext = stack->scontext;
    2227            0 :                             prev->masked_srole = stack->srole;
    2228            0 :                             prev->masked = stack->prior;
    2229            0 :                             prev->state = GUC_SET_LOCAL;
    2230              :                         }
    2231              :                         else
    2232              :                         {
    2233              :                             /* else just forget this stack level */
    2234            0 :                             discard_stack_value(gconf, &stack->prior);
    2235              :                         }
    2236            0 :                         break;
    2237              : 
    2238            0 :                     case GUC_SET_LOCAL:
    2239              :                         /* prior state at this level no longer wanted */
    2240            0 :                         discard_stack_value(gconf, &stack->prior);
    2241              :                         /* copy down the masked state */
    2242            0 :                         prev->masked_scontext = stack->masked_scontext;
    2243            0 :                         prev->masked_srole = stack->masked_srole;
    2244            0 :                         if (prev->state == GUC_SET_LOCAL)
    2245            0 :                             discard_stack_value(gconf, &prev->masked);
    2246            0 :                         prev->masked = stack->masked;
    2247            0 :                         prev->state = GUC_SET_LOCAL;
    2248            0 :                         break;
    2249              :                 }
    2250              :             }
    2251              : 
    2252       241501 :             changed = false;
    2253              : 
    2254       241501 :             if (restorePrior || restoreMasked)
    2255              :             {
    2256              :                 /* Perform appropriate restoration of the stacked value */
    2257              :                 config_var_value newvalue;
    2258              :                 GucSource   newsource;
    2259              :                 GucContext  newscontext;
    2260              :                 Oid         newsrole;
    2261              : 
    2262       210942 :                 if (restoreMasked)
    2263              :                 {
    2264            6 :                     newvalue = stack->masked;
    2265            6 :                     newsource = PGC_S_SESSION;
    2266            6 :                     newscontext = stack->masked_scontext;
    2267            6 :                     newsrole = stack->masked_srole;
    2268              :                 }
    2269              :                 else
    2270              :                 {
    2271       210936 :                     newvalue = stack->prior;
    2272       210936 :                     newsource = stack->source;
    2273       210936 :                     newscontext = stack->scontext;
    2274       210936 :                     newsrole = stack->srole;
    2275              :                 }
    2276              : 
    2277       210942 :                 switch (gconf->vartype)
    2278              :                 {
    2279         1901 :                     case PGC_BOOL:
    2280              :                         {
    2281         1901 :                             struct config_bool *conf = &gconf->_bool;
    2282         1901 :                             bool        newval = newvalue.val.boolval;
    2283         1901 :                             void       *newextra = newvalue.extra;
    2284              : 
    2285         1901 :                             if (*conf->variable != newval ||
    2286          220 :                                 gconf->extra != newextra)
    2287              :                             {
    2288         1681 :                                 if (conf->assign_hook)
    2289            0 :                                     conf->assign_hook(newval, newextra);
    2290         1681 :                                 *conf->variable = newval;
    2291         1681 :                                 set_extra_field(gconf, &gconf->extra,
    2292              :                                                 newextra);
    2293         1681 :                                 changed = true;
    2294              :                             }
    2295         1901 :                             break;
    2296              :                         }
    2297         5140 :                     case PGC_INT:
    2298              :                         {
    2299         5140 :                             struct config_int *conf = &gconf->_int;
    2300         5140 :                             int         newval = newvalue.val.intval;
    2301         5140 :                             void       *newextra = newvalue.extra;
    2302              : 
    2303         5140 :                             if (*conf->variable != newval ||
    2304           99 :                                 gconf->extra != newextra)
    2305              :                             {
    2306         5041 :                                 if (conf->assign_hook)
    2307            0 :                                     conf->assign_hook(newval, newextra);
    2308         5041 :                                 *conf->variable = newval;
    2309         5041 :                                 set_extra_field(gconf, &gconf->extra,
    2310              :                                                 newextra);
    2311         5041 :                                 changed = true;
    2312              :                             }
    2313         5140 :                             break;
    2314              :                         }
    2315          803 :                     case PGC_REAL:
    2316              :                         {
    2317          803 :                             struct config_real *conf = &gconf->_real;
    2318          803 :                             double      newval = newvalue.val.realval;
    2319          803 :                             void       *newextra = newvalue.extra;
    2320              : 
    2321          803 :                             if (*conf->variable != newval ||
    2322           12 :                                 gconf->extra != newextra)
    2323              :                             {
    2324          791 :                                 if (conf->assign_hook)
    2325            0 :                                     conf->assign_hook(newval, newextra);
    2326          791 :                                 *conf->variable = newval;
    2327          791 :                                 set_extra_field(gconf, &gconf->extra,
    2328              :                                                 newextra);
    2329          791 :                                 changed = true;
    2330              :                             }
    2331          803 :                             break;
    2332              :                         }
    2333       194565 :                     case PGC_STRING:
    2334              :                         {
    2335       194565 :                             struct config_string *conf = &gconf->_string;
    2336       194565 :                             char       *newval = newvalue.val.stringval;
    2337       194565 :                             void       *newextra = newvalue.extra;
    2338              : 
    2339       194565 :                             if (*conf->variable != newval ||
    2340           10 :                                 gconf->extra != newextra)
    2341              :                             {
    2342       194555 :                                 if (conf->assign_hook)
    2343       194299 :                                     conf->assign_hook(newval, newextra);
    2344       194555 :                                 set_string_field(gconf, conf->variable, newval);
    2345       194555 :                                 set_extra_field(gconf, &gconf->extra,
    2346              :                                                 newextra);
    2347       194555 :                                 changed = true;
    2348              :                             }
    2349              : 
    2350              :                             /*
    2351              :                              * Release stacked values if not used anymore. We
    2352              :                              * could use discard_stack_value() here, but since
    2353              :                              * we have type-specific code anyway, might as
    2354              :                              * well inline it.
    2355              :                              */
    2356       194565 :                             set_string_field(gconf, &stack->prior.val.stringval, NULL);
    2357       194565 :                             set_string_field(gconf, &stack->masked.val.stringval, NULL);
    2358       194565 :                             break;
    2359              :                         }
    2360         8533 :                     case PGC_ENUM:
    2361              :                         {
    2362         8533 :                             struct config_enum *conf = &gconf->_enum;
    2363         8533 :                             int         newval = newvalue.val.enumval;
    2364         8533 :                             void       *newextra = newvalue.extra;
    2365              : 
    2366         8533 :                             if (*conf->variable != newval ||
    2367          550 :                                 gconf->extra != newextra)
    2368              :                             {
    2369         7983 :                                 if (conf->assign_hook)
    2370           15 :                                     conf->assign_hook(newval, newextra);
    2371         7983 :                                 *conf->variable = newval;
    2372         7983 :                                 set_extra_field(gconf, &gconf->extra,
    2373              :                                                 newextra);
    2374         7983 :                                 changed = true;
    2375              :                             }
    2376         8533 :                             break;
    2377              :                         }
    2378              :                 }
    2379              : 
    2380              :                 /*
    2381              :                  * Release stacked extra values if not used anymore.
    2382              :                  */
    2383       210942 :                 set_extra_field(gconf, &(stack->prior.extra), NULL);
    2384       210942 :                 set_extra_field(gconf, &(stack->masked.extra), NULL);
    2385              : 
    2386              :                 /* And restore source information */
    2387       210942 :                 set_guc_source(gconf, newsource);
    2388       210942 :                 gconf->scontext = newscontext;
    2389       210942 :                 gconf->srole = newsrole;
    2390              :             }
    2391              : 
    2392              :             /*
    2393              :              * Pop the GUC's state stack; if it's now empty, remove the GUC
    2394              :              * from guc_stack_list.
    2395              :              */
    2396       241501 :             gconf->stack = prev;
    2397       241501 :             if (prev == NULL)
    2398       224912 :                 slist_delete_current(&iter);
    2399       241501 :             pfree(stack);
    2400              : 
    2401              :             /* Report new value if we changed it */
    2402       241501 :             if (changed && (gconf->flags & GUC_REPORT) &&
    2403       198436 :                 !(gconf->status & GUC_NEEDS_REPORT))
    2404              :             {
    2405          169 :                 gconf->status |= GUC_NEEDS_REPORT;
    2406          169 :                 slist_push_head(&guc_report_list, &gconf->report_link);
    2407              :             }
    2408              :         }                       /* end of stack-popping loop */
    2409              :     }
    2410              : 
    2411              :     /* Update nesting level */
    2412       793415 :     GUCNestLevel = nestLevel - 1;
    2413       793415 : }
    2414              : 
    2415              : 
    2416              : /*
    2417              :  * Start up automatic reporting of changes to variables marked GUC_REPORT.
    2418              :  * This is executed at completion of backend startup.
    2419              :  */
    2420              : void
    2421        13963 : BeginReportingGUCOptions(void)
    2422              : {
    2423              :     HASH_SEQ_STATUS status;
    2424              :     GUCHashEntry *hentry;
    2425              : 
    2426              :     /*
    2427              :      * Don't do anything unless talking to an interactive frontend.
    2428              :      */
    2429        13963 :     if (whereToSendOutput != DestRemote)
    2430           68 :         return;
    2431              : 
    2432        13895 :     reporting_enabled = true;
    2433              : 
    2434              :     /*
    2435              :      * Hack for in_hot_standby: set the GUC value true if appropriate.  This
    2436              :      * is kind of an ugly place to do it, but there's few better options.
    2437              :      *
    2438              :      * (This could be out of date by the time we actually send it, in which
    2439              :      * case the next ReportChangedGUCOptions call will send a duplicate
    2440              :      * report.)
    2441              :      */
    2442        13895 :     if (RecoveryInProgress())
    2443          651 :         SetConfigOption("in_hot_standby", "true",
    2444              :                         PGC_INTERNAL, PGC_S_OVERRIDE);
    2445              : 
    2446              :     /* Transmit initial values of interesting variables */
    2447        13895 :     hash_seq_init(&status, guc_hashtab);
    2448      5768529 :     while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
    2449              :     {
    2450      5740739 :         struct config_generic *conf = hentry->gucvar;
    2451              : 
    2452      5740739 :         if (conf->flags & GUC_REPORT)
    2453       208425 :             ReportGUCOption(conf);
    2454              :     }
    2455              : }
    2456              : 
    2457              : /*
    2458              :  * ReportChangedGUCOptions: report recently-changed GUC_REPORT variables
    2459              :  *
    2460              :  * This is called just before we wait for a new client query.
    2461              :  *
    2462              :  * By handling things this way, we ensure that a ParameterStatus message
    2463              :  * is sent at most once per variable per query, even if the variable
    2464              :  * changed multiple times within the query.  That's quite possible when
    2465              :  * using features such as function SET clauses.  Function SET clauses
    2466              :  * also tend to cause values to change intraquery but eventually revert
    2467              :  * to their prevailing values; ReportGUCOption is responsible for avoiding
    2468              :  * redundant reports in such cases.
    2469              :  */
    2470              : void
    2471       383980 : ReportChangedGUCOptions(void)
    2472              : {
    2473              :     slist_mutable_iter iter;
    2474              : 
    2475              :     /* Quick exit if not (yet) enabled */
    2476       383980 :     if (!reporting_enabled)
    2477        30950 :         return;
    2478              : 
    2479              :     /*
    2480              :      * Since in_hot_standby isn't actually changed by normal GUC actions, we
    2481              :      * need a hack to check whether a new value needs to be reported to the
    2482              :      * client.  For speed, we rely on the assumption that it can never
    2483              :      * transition from false to true.
    2484              :      */
    2485       353030 :     if (in_hot_standby_guc && !RecoveryInProgress())
    2486            7 :         SetConfigOption("in_hot_standby", "false",
    2487              :                         PGC_INTERNAL, PGC_S_OVERRIDE);
    2488              : 
    2489              :     /* Transmit new values of interesting variables */
    2490       488549 :     slist_foreach_modify(iter, &guc_report_list)
    2491              :     {
    2492       135519 :         struct config_generic *conf = slist_container(struct config_generic,
    2493              :                                                       report_link, iter.cur);
    2494              : 
    2495              :         Assert((conf->flags & GUC_REPORT) && (conf->status & GUC_NEEDS_REPORT));
    2496       135519 :         ReportGUCOption(conf);
    2497       135519 :         conf->status &= ~GUC_NEEDS_REPORT;
    2498       135519 :         slist_delete_current(&iter);
    2499              :     }
    2500              : }
    2501              : 
    2502              : /*
    2503              :  * ReportGUCOption: if appropriate, transmit option value to frontend
    2504              :  *
    2505              :  * We need not transmit the value if it's the same as what we last
    2506              :  * transmitted.
    2507              :  */
    2508              : static void
    2509       343944 : ReportGUCOption(struct config_generic *record)
    2510              : {
    2511       343944 :     char       *val = ShowGUCOption(record, false);
    2512              : 
    2513       343944 :     if (record->last_reported == NULL ||
    2514       135519 :         strcmp(val, record->last_reported) != 0)
    2515              :     {
    2516              :         StringInfoData msgbuf;
    2517              : 
    2518       216240 :         pq_beginmessage(&msgbuf, PqMsg_ParameterStatus);
    2519       216240 :         pq_sendstring(&msgbuf, record->name);
    2520       216240 :         pq_sendstring(&msgbuf, val);
    2521       216240 :         pq_endmessage(&msgbuf);
    2522              : 
    2523              :         /*
    2524              :          * We need a long-lifespan copy.  If guc_strdup() fails due to OOM,
    2525              :          * we'll set last_reported to NULL and thereby possibly make a
    2526              :          * duplicate report later.
    2527              :          */
    2528       216240 :         guc_free(record->last_reported);
    2529       216240 :         record->last_reported = guc_strdup(LOG, val);
    2530              :     }
    2531              : 
    2532       343944 :     pfree(val);
    2533       343944 : }
    2534              : 
    2535              : /*
    2536              :  * Convert a value from one of the human-friendly units ("kB", "min" etc.)
    2537              :  * to the given base unit.  'value' and 'unit' are the input value and unit
    2538              :  * to convert from (there can be trailing spaces in the unit string).
    2539              :  * The converted value is stored in *base_value.
    2540              :  * It's caller's responsibility to round off the converted value as necessary
    2541              :  * and check for out-of-range.
    2542              :  *
    2543              :  * Returns true on success, false if the input unit is not recognized.
    2544              :  */
    2545              : static bool
    2546         8093 : convert_to_base_unit(double value, const char *unit,
    2547              :                      int base_unit, double *base_value)
    2548              : {
    2549              :     char        unitstr[MAX_UNIT_LEN + 1];
    2550              :     int         unitlen;
    2551              :     const unit_conversion *table;
    2552              : 
    2553              :     /* extract unit string to compare to table entries */
    2554         8093 :     unitlen = 0;
    2555        24089 :     while (*unit != '\0' && !isspace((unsigned char) *unit) &&
    2556              :            unitlen < MAX_UNIT_LEN)
    2557        15996 :         unitstr[unitlen++] = *(unit++);
    2558         8093 :     unitstr[unitlen] = '\0';
    2559              :     /* allow whitespace after unit */
    2560         8093 :     while (isspace((unsigned char) *unit))
    2561            0 :         unit++;
    2562         8093 :     if (*unit != '\0')
    2563            0 :         return false;           /* unit too long, or garbage after it */
    2564              : 
    2565              :     /* now search the appropriate table */
    2566         8093 :     if (base_unit & GUC_UNIT_MEMORY)
    2567         6121 :         table = memory_unit_conversion_table;
    2568              :     else
    2569         1972 :         table = time_unit_conversion_table;
    2570              : 
    2571        96350 :     for (int i = 0; *table[i].unit; i++)
    2572              :     {
    2573        96350 :         if (base_unit == table[i].base_unit &&
    2574        27083 :             strcmp(unitstr, table[i].unit) == 0)
    2575              :         {
    2576         8093 :             double      cvalue = value * table[i].multiplier;
    2577              : 
    2578              :             /*
    2579              :              * If the user gave a fractional value such as "30.1GB", round it
    2580              :              * off to the nearest multiple of the next smaller unit, if there
    2581              :              * is one.
    2582              :              */
    2583         8093 :             if (*table[i + 1].unit &&
    2584         8093 :                 base_unit == table[i + 1].base_unit)
    2585         8090 :                 cvalue = rint(cvalue / table[i + 1].multiplier) *
    2586         8090 :                     table[i + 1].multiplier;
    2587              : 
    2588         8093 :             *base_value = cvalue;
    2589         8093 :             return true;
    2590              :         }
    2591              :     }
    2592            0 :     return false;
    2593              : }
    2594              : 
    2595              : /*
    2596              :  * Convert an integer value in some base unit to a human-friendly unit.
    2597              :  *
    2598              :  * The output unit is chosen so that it's the greatest unit that can represent
    2599              :  * the value without loss.  For example, if the base unit is GUC_UNIT_KB, 1024
    2600              :  * is converted to 1 MB, but 1025 is represented as 1025 kB.
    2601              :  */
    2602              : static void
    2603          390 : convert_int_from_base_unit(int64 base_value, int base_unit,
    2604              :                            int64 *value, const char **unit)
    2605              : {
    2606              :     const unit_conversion *table;
    2607              : 
    2608          390 :     *unit = NULL;
    2609              : 
    2610          390 :     if (base_unit & GUC_UNIT_MEMORY)
    2611          334 :         table = memory_unit_conversion_table;
    2612              :     else
    2613           56 :         table = time_unit_conversion_table;
    2614              : 
    2615         2570 :     for (int i = 0; *table[i].unit; i++)
    2616              :     {
    2617         2570 :         if (base_unit == table[i].base_unit)
    2618              :         {
    2619              :             /*
    2620              :              * Accept the first conversion that divides the value evenly.  We
    2621              :              * assume that the conversions for each base unit are ordered from
    2622              :              * greatest unit to the smallest!
    2623              :              */
    2624         1205 :             if (table[i].multiplier <= 1.0 ||
    2625         1148 :                 base_value % (int64) table[i].multiplier == 0)
    2626              :             {
    2627          390 :                 *value = (int64) rint(base_value / table[i].multiplier);
    2628          390 :                 *unit = table[i].unit;
    2629          390 :                 break;
    2630              :             }
    2631              :         }
    2632              :     }
    2633              : 
    2634              :     Assert(*unit != NULL);
    2635          390 : }
    2636              : 
    2637              : /*
    2638              :  * Convert a floating-point value in some base unit to a human-friendly unit.
    2639              :  *
    2640              :  * Same as above, except we have to do the math a bit differently, and
    2641              :  * there's a possibility that we don't find any exact divisor.
    2642              :  */
    2643              : static void
    2644          134 : convert_real_from_base_unit(double base_value, int base_unit,
    2645              :                             double *value, const char **unit)
    2646              : {
    2647              :     const unit_conversion *table;
    2648              : 
    2649          134 :     *unit = NULL;
    2650              : 
    2651          134 :     if (base_unit & GUC_UNIT_MEMORY)
    2652            0 :         table = memory_unit_conversion_table;
    2653              :     else
    2654          134 :         table = time_unit_conversion_table;
    2655              : 
    2656          682 :     for (int i = 0; *table[i].unit; i++)
    2657              :     {
    2658          682 :         if (base_unit == table[i].base_unit)
    2659              :         {
    2660              :             /*
    2661              :              * Accept the first conversion that divides the value evenly; or
    2662              :              * if there is none, use the smallest (last) target unit.
    2663              :              *
    2664              :              * What we actually care about here is whether snprintf with "%g"
    2665              :              * will print the value as an integer, so the obvious test of
    2666              :              * "*value == rint(*value)" is too strict; roundoff error might
    2667              :              * make us choose an unreasonably small unit.  As a compromise,
    2668              :              * accept a divisor that is within 1e-8 of producing an integer.
    2669              :              */
    2670          682 :             *value = base_value / table[i].multiplier;
    2671          682 :             *unit = table[i].unit;
    2672          682 :             if (*value > 0 &&
    2673          682 :                 fabs((rint(*value) / *value) - 1.0) <= 1e-8)
    2674          134 :                 break;
    2675              :         }
    2676              :     }
    2677              : 
    2678              :     Assert(*unit != NULL);
    2679          134 : }
    2680              : 
    2681              : /*
    2682              :  * Return the name of a GUC's base unit (e.g. "ms") given its flags.
    2683              :  * Return NULL if the GUC is unitless.
    2684              :  */
    2685              : const char *
    2686       741560 : get_config_unit_name(int flags)
    2687              : {
    2688       741560 :     switch (flags & GUC_UNIT)
    2689              :     {
    2690       597237 :         case 0:
    2691       597237 :             return NULL;        /* GUC has no units */
    2692         9020 :         case GUC_UNIT_BYTE:
    2693         9020 :             return "B";
    2694        21648 :         case GUC_UNIT_KB:
    2695        21648 :             return "kB";
    2696        10824 :         case GUC_UNIT_MB:
    2697        10824 :             return "MB";
    2698        32472 :         case GUC_UNIT_BLOCKS:
    2699              :             {
    2700              :                 static char bbuf[8];
    2701              : 
    2702              :                 /* initialize if first time through */
    2703        32472 :                 if (bbuf[0] == '\0')
    2704          332 :                     snprintf(bbuf, sizeof(bbuf), "%dkB", BLCKSZ / 1024);
    2705        32472 :                 return bbuf;
    2706              :             }
    2707         3608 :         case GUC_UNIT_XBLOCKS:
    2708              :             {
    2709              :                 static char xbuf[8];
    2710              : 
    2711              :                 /* initialize if first time through */
    2712         3608 :                 if (xbuf[0] == '\0')
    2713          332 :                     snprintf(xbuf, sizeof(xbuf), "%dkB", XLOG_BLCKSZ / 1024);
    2714         3608 :                 return xbuf;
    2715              :             }
    2716        41495 :         case GUC_UNIT_MS:
    2717        41495 :             return "ms";
    2718        21648 :         case GUC_UNIT_S:
    2719        21648 :             return "s";
    2720         3608 :         case GUC_UNIT_MIN:
    2721         3608 :             return "min";
    2722            0 :         default:
    2723            0 :             elog(ERROR, "unrecognized GUC units value: %d",
    2724              :                  flags & GUC_UNIT);
    2725              :             return NULL;
    2726              :     }
    2727              : }
    2728              : 
    2729              : 
    2730              : /*
    2731              :  * Try to parse value as an integer.  The accepted formats are the
    2732              :  * usual decimal, octal, or hexadecimal formats, as well as floating-point
    2733              :  * formats (which will be rounded to integer after any units conversion).
    2734              :  * Optionally, the value can be followed by a unit name if "flags" indicates
    2735              :  * a unit is allowed.
    2736              :  *
    2737              :  * If the string parses okay, return true, else false.
    2738              :  * If okay and result is not NULL, return the value in *result.
    2739              :  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
    2740              :  * HINT message, or NULL if no hint provided.
    2741              :  */
    2742              : bool
    2743        64888 : parse_int(const char *value, int *result, int flags, const char **hintmsg)
    2744              : {
    2745              :     /*
    2746              :      * We assume here that double is wide enough to represent any integer
    2747              :      * value with adequate precision.
    2748              :      */
    2749              :     double      val;
    2750              :     char       *endptr;
    2751              : 
    2752              :     /* To suppress compiler warnings, always set output params */
    2753        64888 :     if (result)
    2754        64888 :         *result = 0;
    2755        64888 :     if (hintmsg)
    2756        59561 :         *hintmsg = NULL;
    2757              : 
    2758              :     /*
    2759              :      * Try to parse as an integer (allowing octal or hex input).  If the
    2760              :      * conversion stops at a decimal point or 'e', or overflows, re-parse as
    2761              :      * float.  This should work fine as long as we have no unit names starting
    2762              :      * with 'e'.  If we ever do, the test could be extended to check for a
    2763              :      * sign or digit after 'e', but for now that's unnecessary.
    2764              :      */
    2765        64888 :     errno = 0;
    2766        64888 :     val = strtol(value, &endptr, 0);
    2767        64888 :     if (*endptr == '.' || *endptr == 'e' || *endptr == 'E' ||
    2768        64882 :         errno == ERANGE)
    2769              :     {
    2770            6 :         errno = 0;
    2771            6 :         val = strtod(value, &endptr);
    2772              :     }
    2773              : 
    2774        64888 :     if (endptr == value || errno == ERANGE)
    2775           17 :         return false;           /* no HINT for these cases */
    2776              : 
    2777              :     /* reject NaN (infinities will fail range check below) */
    2778        64871 :     if (isnan(val))
    2779            0 :         return false;           /* treat same as syntax error; no HINT */
    2780              : 
    2781              :     /* allow whitespace between number and unit */
    2782        64892 :     while (isspace((unsigned char) *endptr))
    2783           21 :         endptr++;
    2784              : 
    2785              :     /* Handle possible unit */
    2786        64871 :     if (*endptr != '\0')
    2787              :     {
    2788         8060 :         if ((flags & GUC_UNIT) == 0)
    2789            5 :             return false;       /* this setting does not accept a unit */
    2790              : 
    2791         8055 :         if (!convert_to_base_unit(val,
    2792              :                                   endptr, (flags & GUC_UNIT),
    2793              :                                   &val))
    2794              :         {
    2795              :             /* invalid unit, or garbage after the unit; set hint and fail. */
    2796            0 :             if (hintmsg)
    2797              :             {
    2798            0 :                 if (flags & GUC_UNIT_MEMORY)
    2799            0 :                     *hintmsg = memory_units_hint;
    2800              :                 else
    2801            0 :                     *hintmsg = time_units_hint;
    2802              :             }
    2803            0 :             return false;
    2804              :         }
    2805              :     }
    2806              : 
    2807              :     /* Round to int, then check for overflow */
    2808        64866 :     val = rint(val);
    2809              : 
    2810        64866 :     if (val > INT_MAX || val < INT_MIN)
    2811              :     {
    2812            3 :         if (hintmsg)
    2813            3 :             *hintmsg = gettext_noop("Value exceeds integer range.");
    2814            3 :         return false;
    2815              :     }
    2816              : 
    2817        64863 :     if (result)
    2818        64863 :         *result = (int) val;
    2819        64863 :     return true;
    2820              : }
    2821              : 
    2822              : /*
    2823              :  * Try to parse value as a floating point number in the usual format.
    2824              :  * Optionally, the value can be followed by a unit name if "flags" indicates
    2825              :  * a unit is allowed.
    2826              :  *
    2827              :  * If the string parses okay, return true, else false.
    2828              :  * If okay and result is not NULL, return the value in *result.
    2829              :  * If not okay and hintmsg is not NULL, *hintmsg is set to a suitable
    2830              :  * HINT message, or NULL if no hint provided.
    2831              :  */
    2832              : bool
    2833         4559 : parse_real(const char *value, double *result, int flags, const char **hintmsg)
    2834              : {
    2835              :     double      val;
    2836              :     char       *endptr;
    2837              : 
    2838              :     /* To suppress compiler warnings, always set output params */
    2839         4559 :     if (result)
    2840         4559 :         *result = 0;
    2841         4559 :     if (hintmsg)
    2842         4292 :         *hintmsg = NULL;
    2843              : 
    2844         4559 :     errno = 0;
    2845         4559 :     val = strtod(value, &endptr);
    2846              : 
    2847         4559 :     if (endptr == value || errno == ERANGE)
    2848            9 :         return false;           /* no HINT for these cases */
    2849              : 
    2850              :     /* reject NaN (infinities will fail range checks later) */
    2851         4550 :     if (isnan(val))
    2852            3 :         return false;           /* treat same as syntax error; no HINT */
    2853              : 
    2854              :     /* allow whitespace between number and unit */
    2855         4547 :     while (isspace((unsigned char) *endptr))
    2856            0 :         endptr++;
    2857              : 
    2858              :     /* Handle possible unit */
    2859         4547 :     if (*endptr != '\0')
    2860              :     {
    2861           40 :         if ((flags & GUC_UNIT) == 0)
    2862            2 :             return false;       /* this setting does not accept a unit */
    2863              : 
    2864           38 :         if (!convert_to_base_unit(val,
    2865              :                                   endptr, (flags & GUC_UNIT),
    2866              :                                   &val))
    2867              :         {
    2868              :             /* invalid unit, or garbage after the unit; set hint and fail. */
    2869            0 :             if (hintmsg)
    2870              :             {
    2871            0 :                 if (flags & GUC_UNIT_MEMORY)
    2872            0 :                     *hintmsg = memory_units_hint;
    2873              :                 else
    2874            0 :                     *hintmsg = time_units_hint;
    2875              :             }
    2876            0 :             return false;
    2877              :         }
    2878              :     }
    2879              : 
    2880         4545 :     if (result)
    2881         4545 :         *result = val;
    2882         4545 :     return true;
    2883              : }
    2884              : 
    2885              : 
    2886              : /*
    2887              :  * Lookup the name for an enum option with the selected value.
    2888              :  * Should only ever be called with known-valid values, so throws
    2889              :  * an elog(ERROR) if the enum option is not found.
    2890              :  *
    2891              :  * The returned string is a pointer to static data and not
    2892              :  * allocated for modification.
    2893              :  */
    2894              : const char *
    2895       247528 : config_enum_lookup_by_value(const struct config_generic *record, int val)
    2896              : {
    2897       569417 :     for (const struct config_enum_entry *entry = record->_enum.options; entry && entry->name; entry++)
    2898              :     {
    2899       569417 :         if (entry->val == val)
    2900       247528 :             return entry->name;
    2901              :     }
    2902              : 
    2903            0 :     elog(ERROR, "could not find enum option %d for %s",
    2904              :          val, record->name);
    2905              :     return NULL;                /* silence compiler */
    2906              : }
    2907              : 
    2908              : 
    2909              : /*
    2910              :  * Lookup the value for an enum option with the selected name
    2911              :  * (case-insensitive).
    2912              :  * If the enum option is found, sets the retval value and returns
    2913              :  * true. If it's not found, return false and retval is set to 0.
    2914              :  */
    2915              : bool
    2916        38499 : config_enum_lookup_by_name(const struct config_enum *record, const char *value,
    2917              :                            int *retval)
    2918              : {
    2919        82883 :     for (const struct config_enum_entry *entry = record->options; entry && entry->name; entry++)
    2920              :     {
    2921        82864 :         if (pg_strcasecmp(value, entry->name) == 0)
    2922              :         {
    2923        38480 :             *retval = entry->val;
    2924        38480 :             return true;
    2925              :         }
    2926              :     }
    2927              : 
    2928           19 :     *retval = 0;
    2929           19 :     return false;
    2930              : }
    2931              : 
    2932              : 
    2933              : /*
    2934              :  * Return a palloc'd string listing all the available options for an enum GUC
    2935              :  * (excluding hidden ones), separated by the given separator.
    2936              :  * If prefix is non-NULL, it is added before the first enum value.
    2937              :  * If suffix is non-NULL, it is added to the end of the string.
    2938              :  */
    2939              : char *
    2940        75464 : config_enum_get_options(const struct config_enum *record, const char *prefix,
    2941              :                         const char *suffix, const char *separator)
    2942              : {
    2943              :     StringInfoData retstr;
    2944              :     int         seplen;
    2945              : 
    2946        75464 :     initStringInfo(&retstr);
    2947        75464 :     appendStringInfoString(&retstr, prefix);
    2948              : 
    2949        75464 :     seplen = strlen(separator);
    2950       466016 :     for (const struct config_enum_entry *entry = record->options; entry && entry->name; entry++)
    2951              :     {
    2952       390552 :         if (!entry->hidden)
    2953              :         {
    2954       276882 :             appendStringInfoString(&retstr, entry->name);
    2955       276882 :             appendBinaryStringInfo(&retstr, separator, seplen);
    2956              :         }
    2957              :     }
    2958              : 
    2959              :     /*
    2960              :      * All the entries may have been hidden, leaving the string empty if no
    2961              :      * prefix was given. This indicates a broken GUC setup, since there is no
    2962              :      * use for an enum without any values, so we just check to make sure we
    2963              :      * don't write to invalid memory instead of actually trying to do
    2964              :      * something smart with it.
    2965              :      */
    2966        75464 :     if (retstr.len >= seplen)
    2967              :     {
    2968              :         /* Replace final separator */
    2969        75464 :         retstr.data[retstr.len - seplen] = '\0';
    2970        75464 :         retstr.len -= seplen;
    2971              :     }
    2972              : 
    2973        75464 :     appendStringInfoString(&retstr, suffix);
    2974              : 
    2975        75464 :     return retstr.data;
    2976              : }
    2977              : 
    2978              : /*
    2979              :  * Parse and validate a proposed value for the specified configuration
    2980              :  * parameter.
    2981              :  *
    2982              :  * This does built-in checks (such as range limits for an integer parameter)
    2983              :  * and also calls any check hook the parameter may have.
    2984              :  *
    2985              :  * record: GUC variable's info record
    2986              :  * value: proposed value, as a string
    2987              :  * source: identifies source of value (check hooks may need this)
    2988              :  * elevel: level to log any error reports at
    2989              :  * newval: on success, converted parameter value is returned here
    2990              :  * newextra: on success, receives any "extra" data returned by check hook
    2991              :  *  (caller must initialize *newextra to NULL)
    2992              :  *
    2993              :  * Returns true if OK, false if not (or throws error, if elevel >= ERROR)
    2994              :  */
    2995              : static bool
    2996       545805 : parse_and_validate_value(const struct config_generic *record,
    2997              :                          const char *value,
    2998              :                          GucSource source, int elevel,
    2999              :                          union config_var_val *newval, void **newextra)
    3000              : {
    3001       545805 :     switch (record->vartype)
    3002              :     {
    3003        82811 :         case PGC_BOOL:
    3004              :             {
    3005        82811 :                 if (!parse_bool(value, &newval->boolval))
    3006              :                 {
    3007            0 :                     ereport(elevel,
    3008              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    3009              :                              errmsg("parameter \"%s\" requires a Boolean value",
    3010              :                                     record->name)));
    3011            0 :                     return false;
    3012              :                 }
    3013              : 
    3014        82811 :                 if (!call_bool_check_hook(record, &newval->boolval, newextra,
    3015              :                                           source, elevel))
    3016            0 :                     return false;
    3017              :             }
    3018        82796 :             break;
    3019        59534 :         case PGC_INT:
    3020              :             {
    3021        59534 :                 const struct config_int *conf = &record->_int;
    3022              :                 const char *hintmsg;
    3023              : 
    3024        59534 :                 if (!parse_int(value, &newval->intval,
    3025        59534 :                                record->flags, &hintmsg))
    3026              :                 {
    3027            3 :                     ereport(elevel,
    3028              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    3029              :                              errmsg("invalid value for parameter \"%s\": \"%s\"",
    3030              :                                     record->name, value),
    3031              :                              hintmsg ? errhint("%s", _(hintmsg)) : 0));
    3032            0 :                     return false;
    3033              :                 }
    3034              : 
    3035        59531 :                 if (newval->intval < conf->min || newval->intval > conf->max)
    3036              :                 {
    3037            2 :                     const char *unit = get_config_unit_name(record->flags);
    3038              :                     const char *unitspace;
    3039              : 
    3040            2 :                     if (unit)
    3041            0 :                         unitspace = " ";
    3042              :                     else
    3043            2 :                         unit = unitspace = "";
    3044              : 
    3045            2 :                     ereport(elevel,
    3046              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    3047              :                              errmsg("%d%s%s is outside the valid range for parameter \"%s\" (%d%s%s .. %d%s%s)",
    3048              :                                     newval->intval, unitspace, unit,
    3049              :                                     record->name,
    3050              :                                     conf->min, unitspace, unit,
    3051              :                                     conf->max, unitspace, unit)));
    3052            0 :                     return false;
    3053              :                 }
    3054              : 
    3055        59529 :                 if (!call_int_check_hook(record, &newval->intval, newextra,
    3056              :                                          source, elevel))
    3057            0 :                     return false;
    3058              :             }
    3059        59529 :             break;
    3060         4257 :         case PGC_REAL:
    3061              :             {
    3062         4257 :                 const struct config_real *conf = &record->_real;
    3063              :                 const char *hintmsg;
    3064              : 
    3065         4257 :                 if (!parse_real(value, &newval->realval,
    3066         4257 :                                 record->flags, &hintmsg))
    3067              :                 {
    3068            3 :                     ereport(elevel,
    3069              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    3070              :                              errmsg("invalid value for parameter \"%s\": \"%s\"",
    3071              :                                     record->name, value),
    3072              :                              hintmsg ? errhint("%s", _(hintmsg)) : 0));
    3073            0 :                     return false;
    3074              :                 }
    3075              : 
    3076         4254 :                 if (newval->realval < conf->min || newval->realval > conf->max)
    3077              :                 {
    3078            3 :                     const char *unit = get_config_unit_name(record->flags);
    3079              :                     const char *unitspace;
    3080              : 
    3081            3 :                     if (unit)
    3082            3 :                         unitspace = " ";
    3083              :                     else
    3084            0 :                         unit = unitspace = "";
    3085              : 
    3086            3 :                     ereport(elevel,
    3087              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    3088              :                              errmsg("%g%s%s is outside the valid range for parameter \"%s\" (%g%s%s .. %g%s%s)",
    3089              :                                     newval->realval, unitspace, unit,
    3090              :                                     record->name,
    3091              :                                     conf->min, unitspace, unit,
    3092              :                                     conf->max, unitspace, unit)));
    3093            0 :                     return false;
    3094              :                 }
    3095              : 
    3096         4251 :                 if (!call_real_check_hook(record, &newval->realval, newextra,
    3097              :                                           source, elevel))
    3098            0 :                     return false;
    3099              :             }
    3100         4251 :             break;
    3101       360704 :         case PGC_STRING:
    3102              :             {
    3103              :                 /*
    3104              :                  * The value passed by the caller could be transient, so we
    3105              :                  * always strdup it.
    3106              :                  */
    3107       360704 :                 newval->stringval = guc_strdup(elevel, value);
    3108       360704 :                 if (newval->stringval == NULL)
    3109            0 :                     return false;
    3110              : 
    3111              :                 /*
    3112              :                  * The only built-in "parsing" check we have is to apply
    3113              :                  * truncation if GUC_IS_NAME.
    3114              :                  */
    3115       360704 :                 if (record->flags & GUC_IS_NAME)
    3116        90486 :                     truncate_identifier(newval->stringval,
    3117        90486 :                                         strlen(newval->stringval),
    3118              :                                         true);
    3119              : 
    3120       360704 :                 if (!call_string_check_hook(record, &newval->stringval, newextra,
    3121              :                                             source, elevel))
    3122              :                 {
    3123            0 :                     guc_free(newval->stringval);
    3124            0 :                     newval->stringval = NULL;
    3125            0 :                     return false;
    3126              :                 }
    3127              :             }
    3128       360648 :             break;
    3129        38499 :         case PGC_ENUM:
    3130              :             {
    3131        38499 :                 const struct config_enum *conf = &record->_enum;
    3132              : 
    3133        38499 :                 if (!config_enum_lookup_by_name(conf, value, &newval->enumval))
    3134              :                 {
    3135              :                     char       *hintmsg;
    3136              : 
    3137           19 :                     hintmsg = config_enum_get_options(conf,
    3138           19 :                                                       _("Available values: "),
    3139              : 
    3140              :                     /*
    3141              :                      * translator: This is the terminator of a list of entity
    3142              :                      * names.
    3143              :                      */
    3144           19 :                                                       _("."),
    3145              : 
    3146              :                     /*
    3147              :                      * translator: This is a separator in a list of entity
    3148              :                      * names.
    3149              :                      */
    3150           19 :                                                       _(", "));
    3151              : 
    3152           19 :                     ereport(elevel,
    3153              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    3154              :                              errmsg("invalid value for parameter \"%s\": \"%s\"",
    3155              :                                     record->name, value),
    3156              :                              hintmsg ? errhint("%s", hintmsg) : 0));
    3157              : 
    3158            0 :                     if (hintmsg)
    3159            0 :                         pfree(hintmsg);
    3160            0 :                     return false;
    3161              :                 }
    3162              : 
    3163        38480 :                 if (!call_enum_check_hook(record, &newval->enumval, newextra,
    3164              :                                           source, elevel))
    3165            0 :                     return false;
    3166              :             }
    3167        38479 :             break;
    3168              :     }
    3169              : 
    3170       545703 :     return true;
    3171              : }
    3172              : 
    3173              : 
    3174              : /*
    3175              :  * set_config_option: sets option `name' to given value.
    3176              :  *
    3177              :  * The value should be a string, which will be parsed and converted to
    3178              :  * the appropriate data type.  The context and source parameters indicate
    3179              :  * in which context this function is being called, so that it can apply the
    3180              :  * access restrictions properly.
    3181              :  *
    3182              :  * If value is NULL, set the option to its default value (normally the
    3183              :  * reset_val, but if source == PGC_S_DEFAULT we instead use the boot_val).
    3184              :  *
    3185              :  * action indicates whether to set the value globally in the session, locally
    3186              :  * to the current top transaction, or just for the duration of a function call.
    3187              :  *
    3188              :  * If changeVal is false then don't really set the option but do all
    3189              :  * the checks to see if it would work.
    3190              :  *
    3191              :  * elevel should normally be passed as zero, allowing this function to make
    3192              :  * its standard choice of ereport level.  However some callers need to be
    3193              :  * able to override that choice; they should pass the ereport level to use.
    3194              :  *
    3195              :  * is_reload should be true only when called from read_nondefault_variables()
    3196              :  * or RestoreGUCState(), where we are trying to load some other process's
    3197              :  * GUC settings into a new process.
    3198              :  *
    3199              :  * Return value:
    3200              :  *  +1: the value is valid and was successfully applied.
    3201              :  *  0:  the name or value is invalid, or it's invalid to try to set
    3202              :  *      this GUC now; but elevel was less than ERROR (see below).
    3203              :  *  -1: no error detected, but the value was not applied, either
    3204              :  *      because changeVal is false or there is some overriding setting.
    3205              :  *
    3206              :  * If there is an error (non-existing option, invalid value, etc) then an
    3207              :  * ereport(ERROR) is thrown *unless* this is called for a source for which
    3208              :  * we don't want an ERROR (currently, those are defaults, the config file,
    3209              :  * and per-database or per-user settings, as well as callers who specify
    3210              :  * a less-than-ERROR elevel).  In those cases we write a suitable error
    3211              :  * message via ereport() and return 0.
    3212              :  *
    3213              :  * See also SetConfigOption for an external interface.
    3214              :  */
    3215              : int
    3216       479763 : set_config_option(const char *name, const char *value,
    3217              :                   GucContext context, GucSource source,
    3218              :                   GucAction action, bool changeVal, int elevel,
    3219              :                   bool is_reload)
    3220              : {
    3221              :     Oid         srole;
    3222              : 
    3223              :     /*
    3224              :      * Non-interactive sources should be treated as having all privileges,
    3225              :      * except for PGC_S_CLIENT.  Note in particular that this is true for
    3226              :      * pg_db_role_setting sources (PGC_S_GLOBAL etc): we assume a suitable
    3227              :      * privilege check was done when the pg_db_role_setting entry was made.
    3228              :      */
    3229       479763 :     if (source >= PGC_S_INTERACTIVE || source == PGC_S_CLIENT)
    3230       259986 :         srole = GetUserId();
    3231              :     else
    3232       219777 :         srole = BOOTSTRAP_SUPERUSERID;
    3233              : 
    3234       479763 :     return set_config_with_handle(name, NULL, value,
    3235              :                                   context, source, srole,
    3236              :                                   action, changeVal, elevel,
    3237              :                                   is_reload);
    3238              : }
    3239              : 
    3240              : /*
    3241              :  * set_config_option_ext: sets option `name' to given value.
    3242              :  *
    3243              :  * This API adds the ability to explicitly specify which role OID
    3244              :  * is considered to be setting the value.  Most external callers can use
    3245              :  * set_config_option() and let it determine that based on the GucSource,
    3246              :  * but there are a few that are supplying a value that was determined
    3247              :  * in some special way and need to override the decision.  Also, when
    3248              :  * restoring a previously-assigned value, it's important to supply the
    3249              :  * same role OID that set the value originally; so all guc.c callers
    3250              :  * that are doing that type of thing need to call this directly.
    3251              :  *
    3252              :  * Generally, srole should be GetUserId() when the source is a SQL operation,
    3253              :  * or BOOTSTRAP_SUPERUSERID if the source is a config file or similar.
    3254              :  */
    3255              : int
    3256        53241 : set_config_option_ext(const char *name, const char *value,
    3257              :                       GucContext context, GucSource source, Oid srole,
    3258              :                       GucAction action, bool changeVal, int elevel,
    3259              :                       bool is_reload)
    3260              : {
    3261        53241 :     return set_config_with_handle(name, NULL, value,
    3262              :                                   context, source, srole,
    3263              :                                   action, changeVal, elevel,
    3264              :                                   is_reload);
    3265              : }
    3266              : 
    3267              : 
    3268              : /*
    3269              :  * set_config_with_handle: sets option `name' to given value.
    3270              :  *
    3271              :  * This API adds the ability to pass a 'handle' argument, which can be
    3272              :  * obtained by the caller from get_config_handle().  NULL has no effect,
    3273              :  * but a non-null value avoids the need to search the GUC tables.
    3274              :  *
    3275              :  * This should be used by callers which repeatedly set the same config
    3276              :  * option(s), and want to avoid the overhead of a hash lookup each time.
    3277              :  */
    3278              : int
    3279       549434 : set_config_with_handle(const char *name, config_handle *handle,
    3280              :                        const char *value,
    3281              :                        GucContext context, GucSource source, Oid srole,
    3282              :                        GucAction action, bool changeVal, int elevel,
    3283              :                        bool is_reload)
    3284              : {
    3285              :     struct config_generic *record;
    3286              :     union config_var_val newval_union;
    3287       549434 :     void       *newextra = NULL;
    3288       549434 :     bool        prohibitValueChange = false;
    3289              :     bool        makeDefault;
    3290              : 
    3291       549434 :     if (elevel == 0)
    3292              :     {
    3293       479861 :         if (source == PGC_S_DEFAULT || source == PGC_S_FILE)
    3294              :         {
    3295              :             /*
    3296              :              * To avoid cluttering the log, only the postmaster bleats loudly
    3297              :              * about problems with the config file.
    3298              :              */
    3299        52646 :             elevel = IsUnderPostmaster ? DEBUG3 : LOG;
    3300              :         }
    3301       427215 :         else if (source == PGC_S_GLOBAL ||
    3302       405718 :                  source == PGC_S_DATABASE ||
    3303       405716 :                  source == PGC_S_USER ||
    3304              :                  source == PGC_S_DATABASE_USER)
    3305        21499 :             elevel = WARNING;
    3306              :         else
    3307       405716 :             elevel = ERROR;
    3308              :     }
    3309              : 
    3310              :     /* if handle is specified, no need to look up option */
    3311       549434 :     if (!handle)
    3312              :     {
    3313       549343 :         record = find_option(name, true, false, elevel);
    3314       549307 :         if (record == NULL)
    3315            0 :             return 0;
    3316              :     }
    3317              :     else
    3318           91 :         record = handle;
    3319              : 
    3320              :     /*
    3321              :      * GUC_ACTION_SAVE changes are acceptable during a parallel operation,
    3322              :      * because the current worker will also pop the change.  We're probably
    3323              :      * dealing with a function having a proconfig entry.  Only the function's
    3324              :      * body should observe the change, and peer workers do not share in the
    3325              :      * execution of a function call started by this worker.
    3326              :      *
    3327              :      * Also allow normal setting if the GUC is marked GUC_ALLOW_IN_PARALLEL.
    3328              :      *
    3329              :      * Other changes might need to affect other workers, so forbid them.
    3330              :      */
    3331       549398 :     if (IsInParallelMode() && changeVal && action != GUC_ACTION_SAVE &&
    3332            9 :         (record->flags & GUC_ALLOW_IN_PARALLEL) == 0)
    3333              :     {
    3334            0 :         ereport(elevel,
    3335              :                 (errcode(ERRCODE_INVALID_TRANSACTION_STATE),
    3336              :                  errmsg("parameter \"%s\" cannot be set during a parallel operation",
    3337              :                         record->name)));
    3338            0 :         return 0;
    3339              :     }
    3340              : 
    3341              :     /*
    3342              :      * Check if the option can be set at this time. See guc.h for the precise
    3343              :      * rules.
    3344              :      */
    3345       549398 :     switch (record->context)
    3346              :     {
    3347        68837 :         case PGC_INTERNAL:
    3348        68837 :             if (context != PGC_INTERNAL)
    3349              :             {
    3350            2 :                 ereport(elevel,
    3351              :                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3352              :                          errmsg("parameter \"%s\" cannot be changed",
    3353              :                                 record->name)));
    3354            0 :                 return 0;
    3355              :             }
    3356        68835 :             break;
    3357        33427 :         case PGC_POSTMASTER:
    3358        33427 :             if (context == PGC_SIGHUP)
    3359              :             {
    3360              :                 /*
    3361              :                  * We are re-reading a PGC_POSTMASTER variable from
    3362              :                  * postgresql.conf.  We can't change the setting, so we should
    3363              :                  * give a warning if the DBA tries to change it.  However,
    3364              :                  * because of variant formats, canonicalization by check
    3365              :                  * hooks, etc, we can't just compare the given string directly
    3366              :                  * to what's stored.  Set a flag to check below after we have
    3367              :                  * the final storable value.
    3368              :                  */
    3369         9011 :                 prohibitValueChange = true;
    3370              :             }
    3371        24416 :             else if (context != PGC_POSTMASTER)
    3372              :             {
    3373            4 :                 ereport(elevel,
    3374              :                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3375              :                          errmsg("parameter \"%s\" cannot be changed without restarting the server",
    3376              :                                 record->name)));
    3377            0 :                 return 0;
    3378              :             }
    3379        33423 :             break;
    3380        27608 :         case PGC_SIGHUP:
    3381        27608 :             if (context != PGC_SIGHUP && context != PGC_POSTMASTER)
    3382              :             {
    3383            3 :                 ereport(elevel,
    3384              :                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3385              :                          errmsg("parameter \"%s\" cannot be changed now",
    3386              :                                 record->name)));
    3387            0 :                 return 0;
    3388              :             }
    3389              : 
    3390              :             /*
    3391              :              * Hmm, the idea of the SIGHUP context is "ought to be global, but
    3392              :              * can be changed after postmaster start". But there's nothing
    3393              :              * that prevents a crafty administrator from sending SIGHUP
    3394              :              * signals to individual backends only.
    3395              :              */
    3396        27605 :             break;
    3397          179 :         case PGC_SU_BACKEND:
    3398          179 :             if (context == PGC_BACKEND)
    3399              :             {
    3400              :                 /*
    3401              :                  * Check whether the requesting user has been granted
    3402              :                  * privilege to set this GUC.
    3403              :                  */
    3404              :                 AclResult   aclresult;
    3405              : 
    3406            0 :                 aclresult = pg_parameter_aclcheck(record->name, srole, ACL_SET);
    3407            0 :                 if (aclresult != ACLCHECK_OK)
    3408              :                 {
    3409              :                     /* No granted privilege */
    3410            0 :                     ereport(elevel,
    3411              :                             (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    3412              :                              errmsg("permission denied to set parameter \"%s\"",
    3413              :                                     record->name)));
    3414            0 :                     return 0;
    3415              :                 }
    3416              :             }
    3417              :             /* fall through to process the same as PGC_BACKEND */
    3418              :             pg_fallthrough;
    3419              :         case PGC_BACKEND:
    3420          181 :             if (context == PGC_SIGHUP)
    3421              :             {
    3422              :                 /*
    3423              :                  * If a PGC_BACKEND or PGC_SU_BACKEND parameter is changed in
    3424              :                  * the config file, we want to accept the new value in the
    3425              :                  * postmaster (whence it will propagate to
    3426              :                  * subsequently-started backends), but ignore it in existing
    3427              :                  * backends.  This is a tad klugy, but necessary because we
    3428              :                  * don't re-read the config file during backend start.
    3429              :                  *
    3430              :                  * However, if changeVal is false then plow ahead anyway since
    3431              :                  * we are trying to find out if the value is potentially good,
    3432              :                  * not actually use it.
    3433              :                  *
    3434              :                  * In EXEC_BACKEND builds, this works differently: we load all
    3435              :                  * non-default settings from the CONFIG_EXEC_PARAMS file
    3436              :                  * during backend start.  In that case we must accept
    3437              :                  * PGC_SIGHUP settings, so as to have the same value as if
    3438              :                  * we'd forked from the postmaster.  This can also happen when
    3439              :                  * using RestoreGUCState() within a background worker that
    3440              :                  * needs to have the same settings as the user backend that
    3441              :                  * started it. is_reload will be true when either situation
    3442              :                  * applies.
    3443              :                  */
    3444          105 :                 if (IsUnderPostmaster && changeVal && !is_reload)
    3445           52 :                     return -1;
    3446              :             }
    3447           76 :             else if (context != PGC_POSTMASTER &&
    3448            4 :                      context != PGC_BACKEND &&
    3449            4 :                      context != PGC_SU_BACKEND &&
    3450              :                      source != PGC_S_CLIENT)
    3451              :             {
    3452            4 :                 ereport(elevel,
    3453              :                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3454              :                          errmsg("parameter \"%s\" cannot be set after connection start",
    3455              :                                 record->name)));
    3456            0 :                 return 0;
    3457              :             }
    3458          125 :             break;
    3459        22083 :         case PGC_SUSET:
    3460        22083 :             if (context == PGC_USERSET || context == PGC_BACKEND)
    3461              :             {
    3462              :                 /*
    3463              :                  * Check whether the requesting user has been granted
    3464              :                  * privilege to set this GUC.
    3465              :                  */
    3466              :                 AclResult   aclresult;
    3467              : 
    3468           15 :                 aclresult = pg_parameter_aclcheck(record->name, srole, ACL_SET);
    3469           15 :                 if (aclresult != ACLCHECK_OK)
    3470              :                 {
    3471              :                     /* No granted privilege */
    3472            8 :                     ereport(elevel,
    3473              :                             (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    3474              :                              errmsg("permission denied to set parameter \"%s\"",
    3475              :                                     record->name)));
    3476            2 :                     return 0;
    3477              :                 }
    3478              :             }
    3479        22075 :             break;
    3480       397262 :         case PGC_USERSET:
    3481              :             /* always okay */
    3482       397262 :             break;
    3483              :     }
    3484              : 
    3485              :     /*
    3486              :      * Disallow changing GUC_NOT_WHILE_SEC_REST values if we are inside a
    3487              :      * security restriction context.  We can reject this regardless of the GUC
    3488              :      * context or source, mainly because sources that it might be reasonable
    3489              :      * to override for won't be seen while inside a function.
    3490              :      *
    3491              :      * Note: variables marked GUC_NOT_WHILE_SEC_REST should usually be marked
    3492              :      * GUC_NO_RESET_ALL as well, because ResetAllOptions() doesn't check this.
    3493              :      * An exception might be made if the reset value is assumed to be "safe".
    3494              :      *
    3495              :      * Note: this flag is currently used for "session_authorization" and
    3496              :      * "role".  We need to prohibit changing these inside a local userid
    3497              :      * context because when we exit it, GUC won't be notified, leaving things
    3498              :      * out of sync.  (This could be fixed by forcing a new GUC nesting level,
    3499              :      * but that would change behavior in possibly-undesirable ways.)  Also, we
    3500              :      * prohibit changing these in a security-restricted operation because
    3501              :      * otherwise RESET could be used to regain the session user's privileges.
    3502              :      */
    3503       549325 :     if (record->flags & GUC_NOT_WHILE_SEC_REST)
    3504              :     {
    3505        36528 :         if (InLocalUserIdChange())
    3506              :         {
    3507              :             /*
    3508              :              * Phrasing of this error message is historical, but it's the most
    3509              :              * common case.
    3510              :              */
    3511            0 :             ereport(elevel,
    3512              :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    3513              :                      errmsg("cannot set parameter \"%s\" within security-definer function",
    3514              :                             record->name)));
    3515            0 :             return 0;
    3516              :         }
    3517        36528 :         if (InSecurityRestrictedOperation())
    3518              :         {
    3519            0 :             ereport(elevel,
    3520              :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    3521              :                      errmsg("cannot set parameter \"%s\" within security-restricted operation",
    3522              :                             record->name)));
    3523            0 :             return 0;
    3524              :         }
    3525              :     }
    3526              : 
    3527              :     /* Disallow resetting and saving GUC_NO_RESET values */
    3528       549325 :     if (record->flags & GUC_NO_RESET)
    3529              :     {
    3530        12525 :         if (value == NULL)
    3531              :         {
    3532            9 :             ereport(elevel,
    3533              :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    3534              :                      errmsg("parameter \"%s\" cannot be reset", record->name)));
    3535            0 :             return 0;
    3536              :         }
    3537        12516 :         if (action == GUC_ACTION_SAVE)
    3538              :         {
    3539            3 :             ereport(elevel,
    3540              :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    3541              :                      errmsg("parameter \"%s\" cannot be set locally in functions",
    3542              :                             record->name)));
    3543            0 :             return 0;
    3544              :         }
    3545              :     }
    3546              : 
    3547              :     /*
    3548              :      * Should we set reset/stacked values?  (If so, the behavior is not
    3549              :      * transactional.)  This is done either when we get a default value from
    3550              :      * the database's/user's/client's default settings or when we reset a
    3551              :      * value to its default.
    3552              :      */
    3553       549314 :     makeDefault = changeVal && (source <= PGC_S_OVERRIDE) &&
    3554            1 :         ((value != NULL) || source == PGC_S_DEFAULT);
    3555              : 
    3556              :     /*
    3557              :      * Ignore attempted set if overridden by previously processed setting.
    3558              :      * However, if changeVal is false then plow ahead anyway since we are
    3559              :      * trying to find out if the value is potentially good, not actually use
    3560              :      * it. Also keep going if makeDefault is true, since we may want to set
    3561              :      * the reset/stacked values even if we can't set the variable itself.
    3562              :      */
    3563       549313 :     if (record->source > source)
    3564              :     {
    3565         1206 :         if (changeVal && !makeDefault)
    3566              :         {
    3567            0 :             elog(DEBUG3, "\"%s\": setting ignored because previous source is higher priority",
    3568              :                  record->name);
    3569            0 :             return -1;
    3570              :         }
    3571         1206 :         changeVal = false;
    3572              :     }
    3573              : 
    3574              :     /*
    3575              :      * Evaluate value and set variable.
    3576              :      */
    3577       549313 :     switch (record->vartype)
    3578              :     {
    3579        83590 :         case PGC_BOOL:
    3580              :             {
    3581        83590 :                 struct config_bool *conf = &record->_bool;
    3582              : 
    3583              : #define newval (newval_union.boolval)
    3584              : 
    3585        83590 :                 if (value)
    3586              :                 {
    3587        82799 :                     if (!parse_and_validate_value(record, value,
    3588              :                                                   source, elevel,
    3589              :                                                   &newval_union, &newextra))
    3590            0 :                         return 0;
    3591              :                 }
    3592          791 :                 else if (source == PGC_S_DEFAULT)
    3593              :                 {
    3594            0 :                     newval = conf->boot_val;
    3595            0 :                     if (!call_bool_check_hook(record, &newval, &newextra,
    3596              :                                               source, elevel))
    3597            0 :                         return 0;
    3598              :                 }
    3599              :                 else
    3600              :                 {
    3601          791 :                     newval = conf->reset_val;
    3602          791 :                     newextra = record->reset_extra;
    3603          791 :                     source = record->reset_source;
    3604          791 :                     context = record->reset_scontext;
    3605          791 :                     srole = record->reset_srole;
    3606              :                 }
    3607              : 
    3608        83575 :                 if (prohibitValueChange)
    3609              :                 {
    3610              :                     /* Release newextra, unless it's reset_extra */
    3611          923 :                     if (newextra && !extra_field_used(record, newextra))
    3612            0 :                         guc_free(newextra);
    3613              : 
    3614          923 :                     if (*conf->variable != newval)
    3615              :                     {
    3616            0 :                         record->status |= GUC_PENDING_RESTART;
    3617            0 :                         ereport(elevel,
    3618              :                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3619              :                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
    3620              :                                         record->name)));
    3621            0 :                         return 0;
    3622              :                     }
    3623          923 :                     record->status &= ~GUC_PENDING_RESTART;
    3624          923 :                     return -1;
    3625              :                 }
    3626              : 
    3627        82652 :                 if (changeVal)
    3628              :                 {
    3629              :                     /* Save old value to support transaction abort */
    3630        82586 :                     if (!makeDefault)
    3631        15145 :                         push_old_value(record, action);
    3632              : 
    3633        82586 :                     if (conf->assign_hook)
    3634            0 :                         conf->assign_hook(newval, newextra);
    3635        82586 :                     *conf->variable = newval;
    3636        82586 :                     set_extra_field(record, &record->extra,
    3637              :                                     newextra);
    3638        82586 :                     set_guc_source(record, source);
    3639        82586 :                     record->scontext = context;
    3640        82586 :                     record->srole = srole;
    3641              :                 }
    3642        82652 :                 if (makeDefault)
    3643              :                 {
    3644        67495 :                     if (record->reset_source <= source)
    3645              :                     {
    3646        67441 :                         conf->reset_val = newval;
    3647        67441 :                         set_extra_field(record, &record->reset_extra,
    3648              :                                         newextra);
    3649        67441 :                         record->reset_source = source;
    3650        67441 :                         record->reset_scontext = context;
    3651        67441 :                         record->reset_srole = srole;
    3652              :                     }
    3653        67495 :                     for (GucStack *stack = record->stack; stack; stack = stack->prev)
    3654              :                     {
    3655            0 :                         if (stack->source <= source)
    3656              :                         {
    3657            0 :                             stack->prior.val.boolval = newval;
    3658            0 :                             set_extra_field(record, &stack->prior.extra,
    3659              :                                             newextra);
    3660            0 :                             stack->source = source;
    3661            0 :                             stack->scontext = context;
    3662            0 :                             stack->srole = srole;
    3663              :                         }
    3664              :                     }
    3665              :                 }
    3666              : 
    3667              :                 /* Perhaps we didn't install newextra anywhere */
    3668        82652 :                 if (newextra && !extra_field_used(record, newextra))
    3669            0 :                     guc_free(newextra);
    3670        82652 :                 break;
    3671              : 
    3672              : #undef newval
    3673              :             }
    3674              : 
    3675        60266 :         case PGC_INT:
    3676              :             {
    3677        60266 :                 struct config_int *conf = &record->_int;
    3678              : 
    3679              : #define newval (newval_union.intval)
    3680              : 
    3681        60266 :                 if (value)
    3682              :                 {
    3683        59516 :                     if (!parse_and_validate_value(record, value,
    3684              :                                                   source, elevel,
    3685              :                                                   &newval_union, &newextra))
    3686            0 :                         return 0;
    3687              :                 }
    3688          750 :                 else if (source == PGC_S_DEFAULT)
    3689              :                 {
    3690            0 :                     newval = conf->boot_val;
    3691            0 :                     if (!call_int_check_hook(record, &newval, &newextra,
    3692              :                                              source, elevel))
    3693            0 :                         return 0;
    3694              :                 }
    3695              :                 else
    3696              :                 {
    3697          750 :                     newval = conf->reset_val;
    3698          750 :                     newextra = record->reset_extra;
    3699          750 :                     source = record->reset_source;
    3700          750 :                     context = record->reset_scontext;
    3701          750 :                     srole = record->reset_srole;
    3702              :                 }
    3703              : 
    3704        60263 :                 if (prohibitValueChange)
    3705              :                 {
    3706              :                     /* Release newextra, unless it's reset_extra */
    3707         4662 :                     if (newextra && !extra_field_used(record, newextra))
    3708            0 :                         guc_free(newextra);
    3709              : 
    3710         4662 :                     if (*conf->variable != newval)
    3711              :                     {
    3712            0 :                         record->status |= GUC_PENDING_RESTART;
    3713            0 :                         ereport(elevel,
    3714              :                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3715              :                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
    3716              :                                         record->name)));
    3717            0 :                         return 0;
    3718              :                     }
    3719         4662 :                     record->status &= ~GUC_PENDING_RESTART;
    3720         4662 :                     return -1;
    3721              :                 }
    3722              : 
    3723        55601 :                 if (changeVal)
    3724              :                 {
    3725              :                     /* Save old value to support transaction abort */
    3726        54693 :                     if (!makeDefault)
    3727        11960 :                         push_old_value(record, action);
    3728              : 
    3729        54693 :                     if (conf->assign_hook)
    3730         9544 :                         conf->assign_hook(newval, newextra);
    3731        54693 :                     *conf->variable = newval;
    3732        54693 :                     set_extra_field(record, &record->extra,
    3733              :                                     newextra);
    3734        54693 :                     set_guc_source(record, source);
    3735        54693 :                     record->scontext = context;
    3736        54693 :                     record->srole = srole;
    3737              :                 }
    3738        55601 :                 if (makeDefault)
    3739              :                 {
    3740        43596 :                     if (record->reset_source <= source)
    3741              :                     {
    3742        42733 :                         conf->reset_val = newval;
    3743        42733 :                         set_extra_field(record, &record->reset_extra,
    3744              :                                         newextra);
    3745        42733 :                         record->reset_source = source;
    3746        42733 :                         record->reset_scontext = context;
    3747        42733 :                         record->reset_srole = srole;
    3748              :                     }
    3749        43596 :                     for (GucStack *stack = record->stack; stack; stack = stack->prev)
    3750              :                     {
    3751            0 :                         if (stack->source <= source)
    3752              :                         {
    3753            0 :                             stack->prior.val.intval = newval;
    3754            0 :                             set_extra_field(record, &stack->prior.extra,
    3755              :                                             newextra);
    3756            0 :                             stack->source = source;
    3757            0 :                             stack->scontext = context;
    3758            0 :                             stack->srole = srole;
    3759              :                         }
    3760              :                     }
    3761              :                 }
    3762              : 
    3763              :                 /* Perhaps we didn't install newextra anywhere */
    3764        55601 :                 if (newextra && !extra_field_used(record, newextra))
    3765            0 :                     guc_free(newextra);
    3766        55601 :                 break;
    3767              : 
    3768              : #undef newval
    3769              :             }
    3770              : 
    3771         4351 :         case PGC_REAL:
    3772              :             {
    3773         4351 :                 struct config_real *conf = &record->_real;
    3774              : 
    3775              : #define newval (newval_union.realval)
    3776              : 
    3777         4351 :                 if (value)
    3778              :                 {
    3779         4257 :                     if (!parse_and_validate_value(record, value,
    3780              :                                                   source, elevel,
    3781              :                                                   &newval_union, &newextra))
    3782            0 :                         return 0;
    3783              :                 }
    3784           94 :                 else if (source == PGC_S_DEFAULT)
    3785              :                 {
    3786            0 :                     newval = conf->boot_val;
    3787            0 :                     if (!call_real_check_hook(record, &newval, &newextra,
    3788              :                                               source, elevel))
    3789            0 :                         return 0;
    3790              :                 }
    3791              :                 else
    3792              :                 {
    3793           94 :                     newval = conf->reset_val;
    3794           94 :                     newextra = record->reset_extra;
    3795           94 :                     source = record->reset_source;
    3796           94 :                     context = record->reset_scontext;
    3797           94 :                     srole = record->reset_srole;
    3798              :                 }
    3799              : 
    3800         4345 :                 if (prohibitValueChange)
    3801              :                 {
    3802              :                     /* Release newextra, unless it's reset_extra */
    3803            0 :                     if (newextra && !extra_field_used(record, newextra))
    3804            0 :                         guc_free(newextra);
    3805              : 
    3806            0 :                     if (*conf->variable != newval)
    3807              :                     {
    3808            0 :                         record->status |= GUC_PENDING_RESTART;
    3809            0 :                         ereport(elevel,
    3810              :                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3811              :                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
    3812              :                                         record->name)));
    3813            0 :                         return 0;
    3814              :                     }
    3815            0 :                     record->status &= ~GUC_PENDING_RESTART;
    3816            0 :                     return -1;
    3817              :                 }
    3818              : 
    3819         4345 :                 if (changeVal)
    3820              :                 {
    3821              :                     /* Save old value to support transaction abort */
    3822         4345 :                     if (!makeDefault)
    3823         4345 :                         push_old_value(record, action);
    3824              : 
    3825         4345 :                     if (conf->assign_hook)
    3826            0 :                         conf->assign_hook(newval, newextra);
    3827         4345 :                     *conf->variable = newval;
    3828         4345 :                     set_extra_field(record, &record->extra,
    3829              :                                     newextra);
    3830         4345 :                     set_guc_source(record, source);
    3831         4345 :                     record->scontext = context;
    3832         4345 :                     record->srole = srole;
    3833              :                 }
    3834         4345 :                 if (makeDefault)
    3835              :                 {
    3836            0 :                     if (record->reset_source <= source)
    3837              :                     {
    3838            0 :                         conf->reset_val = newval;
    3839            0 :                         set_extra_field(record, &record->reset_extra,
    3840              :                                         newextra);
    3841            0 :                         record->reset_source = source;
    3842            0 :                         record->reset_scontext = context;
    3843            0 :                         record->reset_srole = srole;
    3844              :                     }
    3845            0 :                     for (GucStack *stack = record->stack; stack; stack = stack->prev)
    3846              :                     {
    3847            0 :                         if (stack->source <= source)
    3848              :                         {
    3849            0 :                             stack->prior.val.realval = newval;
    3850            0 :                             set_extra_field(record, &stack->prior.extra,
    3851              :                                             newextra);
    3852            0 :                             stack->source = source;
    3853            0 :                             stack->scontext = context;
    3854            0 :                             stack->srole = srole;
    3855              :                         }
    3856              :                     }
    3857              :                 }
    3858              : 
    3859              :                 /* Perhaps we didn't install newextra anywhere */
    3860         4345 :                 if (newextra && !extra_field_used(record, newextra))
    3861            0 :                     guc_free(newextra);
    3862         4345 :                 break;
    3863              : 
    3864              : #undef newval
    3865              :             }
    3866              : 
    3867       362322 :         case PGC_STRING:
    3868              :             {
    3869       362322 :                 struct config_string *conf = &record->_string;
    3870       362322 :                 GucContext  orig_context = context;
    3871       362322 :                 GucSource   orig_source = source;
    3872       362322 :                 Oid         orig_srole = srole;
    3873              : 
    3874              : #define newval (newval_union.stringval)
    3875              : 
    3876       362322 :                 if (value)
    3877              :                 {
    3878       360665 :                     if (!parse_and_validate_value(record, value,
    3879              :                                                   source, elevel,
    3880              :                                                   &newval_union, &newextra))
    3881            0 :                         return 0;
    3882              :                 }
    3883         1657 :                 else if (source == PGC_S_DEFAULT)
    3884              :                 {
    3885              :                     /* non-NULL boot_val must always get strdup'd */
    3886            1 :                     if (conf->boot_val != NULL)
    3887              :                     {
    3888            1 :                         newval = guc_strdup(elevel, conf->boot_val);
    3889            1 :                         if (newval == NULL)
    3890            0 :                             return 0;
    3891              :                     }
    3892              :                     else
    3893            0 :                         newval = NULL;
    3894              : 
    3895            1 :                     if (!call_string_check_hook(record, &newval, &newextra,
    3896              :                                                 source, elevel))
    3897              :                     {
    3898            0 :                         guc_free(newval);
    3899            0 :                         return 0;
    3900              :                     }
    3901              :                 }
    3902              :                 else
    3903              :                 {
    3904              :                     /*
    3905              :                      * strdup not needed, since reset_val is already under
    3906              :                      * guc.c's control
    3907              :                      */
    3908         1656 :                     newval = conf->reset_val;
    3909         1656 :                     newextra = record->reset_extra;
    3910         1656 :                     source = record->reset_source;
    3911         1656 :                     context = record->reset_scontext;
    3912         1656 :                     srole = record->reset_srole;
    3913              :                 }
    3914              : 
    3915       362274 :                 if (prohibitValueChange)
    3916              :                 {
    3917              :                     bool        newval_different;
    3918              : 
    3919              :                     /* newval shouldn't be NULL, so we're a bit sloppy here */
    3920         4842 :                     newval_different = (*conf->variable == NULL ||
    3921         3228 :                                         newval == NULL ||
    3922         1614 :                                         strcmp(*conf->variable, newval) != 0);
    3923              : 
    3924              :                     /* Release newval, unless it's reset_val */
    3925         1614 :                     if (newval && !string_field_used(record, newval))
    3926         1614 :                         guc_free(newval);
    3927              :                     /* Release newextra, unless it's reset_extra */
    3928         1614 :                     if (newextra && !extra_field_used(record, newextra))
    3929            0 :                         guc_free(newextra);
    3930              : 
    3931         1614 :                     if (newval_different)
    3932              :                     {
    3933            0 :                         record->status |= GUC_PENDING_RESTART;
    3934            0 :                         ereport(elevel,
    3935              :                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    3936              :                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
    3937              :                                         record->name)));
    3938            0 :                         return 0;
    3939              :                     }
    3940         1614 :                     record->status &= ~GUC_PENDING_RESTART;
    3941         1614 :                     return -1;
    3942              :                 }
    3943              : 
    3944       360660 :                 if (changeVal)
    3945              :                 {
    3946              :                     /* Save old value to support transaction abort */
    3947       359780 :                     if (!makeDefault)
    3948       205145 :                         push_old_value(record, action);
    3949              : 
    3950       359780 :                     if (conf->assign_hook)
    3951       330003 :                         conf->assign_hook(newval, newextra);
    3952       359779 :                     set_string_field(record, conf->variable, newval);
    3953       359779 :                     set_extra_field(record, &record->extra,
    3954              :                                     newextra);
    3955       359779 :                     set_guc_source(record, source);
    3956       359779 :                     record->scontext = context;
    3957       359779 :                     record->srole = srole;
    3958              : 
    3959              :                     /*
    3960              :                      * Ugly hack: during SET session_authorization, forcibly
    3961              :                      * do SET ROLE NONE with the same context/source/etc, so
    3962              :                      * that the effects will have identical lifespan.  This is
    3963              :                      * required by the SQL spec, and it's not possible to do
    3964              :                      * it within the variable's check hook or assign hook
    3965              :                      * because our APIs for those don't pass enough info.
    3966              :                      * However, don't do it if is_reload: in that case we
    3967              :                      * expect that if "role" isn't supposed to be default, it
    3968              :                      * has been or will be set by a separate reload action.
    3969              :                      *
    3970              :                      * Also, for the call from InitializeSessionUserId with
    3971              :                      * source == PGC_S_OVERRIDE, use PGC_S_DYNAMIC_DEFAULT for
    3972              :                      * "role"'s source, so that it's still possible to set
    3973              :                      * "role" from pg_db_role_setting entries.  (See notes in
    3974              :                      * InitializeSessionUserId before changing this.)
    3975              :                      *
    3976              :                      * A fine point: for RESET session_authorization, we do
    3977              :                      * "RESET role" not "SET ROLE NONE" (by passing down NULL
    3978              :                      * rather than "none" for the value).  This would have the
    3979              :                      * same effects in typical cases, but if the reset value
    3980              :                      * of "role" is not "none" it seems better to revert to
    3981              :                      * that.
    3982              :                      */
    3983       359779 :                     if (!is_reload &&
    3984       338329 :                         strcmp(record->name, "session_authorization") == 0)
    3985        16339 :                         (void) set_config_with_handle("role", NULL,
    3986              :                                                       value ? "none" : NULL,
    3987              :                                                       orig_context,
    3988              :                                                       (orig_source == PGC_S_OVERRIDE)
    3989              :                                                       ? PGC_S_DYNAMIC_DEFAULT
    3990              :                                                       : orig_source,
    3991              :                                                       orig_srole,
    3992              :                                                       action,
    3993              :                                                       true,
    3994              :                                                       elevel,
    3995              :                                                       false);
    3996              :                 }
    3997              : 
    3998       360659 :                 if (makeDefault)
    3999              :                 {
    4000       154885 :                     if (record->reset_source <= source)
    4001              :                     {
    4002       154634 :                         set_string_field(record, &conf->reset_val, newval);
    4003       154634 :                         set_extra_field(record, &record->reset_extra,
    4004              :                                         newextra);
    4005       154634 :                         record->reset_source = source;
    4006       154634 :                         record->reset_scontext = context;
    4007       154634 :                         record->reset_srole = srole;
    4008              :                     }
    4009       154885 :                     for (GucStack *stack = record->stack; stack; stack = stack->prev)
    4010              :                     {
    4011            0 :                         if (stack->source <= source)
    4012              :                         {
    4013            0 :                             set_string_field(record, &stack->prior.val.stringval,
    4014              :                                              newval);
    4015            0 :                             set_extra_field(record, &stack->prior.extra,
    4016              :                                             newextra);
    4017            0 :                             stack->source = source;
    4018            0 :                             stack->scontext = context;
    4019            0 :                             stack->srole = srole;
    4020              :                         }
    4021              :                     }
    4022              :                 }
    4023              : 
    4024              :                 /* Perhaps we didn't install newval anywhere */
    4025       360659 :                 if (newval && !string_field_used(record, newval))
    4026          866 :                     guc_free(newval);
    4027              :                 /* Perhaps we didn't install newextra anywhere */
    4028       360659 :                 if (newextra && !extra_field_used(record, newextra))
    4029          254 :                     guc_free(newextra);
    4030       360659 :                 break;
    4031              : 
    4032              : #undef newval
    4033              :             }
    4034              : 
    4035        38784 :         case PGC_ENUM:
    4036              :             {
    4037        38784 :                 struct config_enum *conf = &record->_enum;
    4038              : 
    4039              : #define newval (newval_union.enumval)
    4040              : 
    4041        38784 :                 if (value)
    4042              :                 {
    4043        38498 :                     if (!parse_and_validate_value(record, value,
    4044              :                                                   source, elevel,
    4045              :                                                   &newval_union, &newextra))
    4046            0 :                         return 0;
    4047              :                 }
    4048          286 :                 else if (source == PGC_S_DEFAULT)
    4049              :                 {
    4050            0 :                     newval = conf->boot_val;
    4051            0 :                     if (!call_enum_check_hook(record, &newval, &newextra,
    4052              :                                               source, elevel))
    4053            0 :                         return 0;
    4054              :                 }
    4055              :                 else
    4056              :                 {
    4057          286 :                     newval = conf->reset_val;
    4058          286 :                     newextra = record->reset_extra;
    4059          286 :                     source = record->reset_source;
    4060          286 :                     context = record->reset_scontext;
    4061          286 :                     srole = record->reset_srole;
    4062              :                 }
    4063              : 
    4064        38764 :                 if (prohibitValueChange)
    4065              :                 {
    4066              :                     /* Release newextra, unless it's reset_extra */
    4067         1812 :                     if (newextra && !extra_field_used(record, newextra))
    4068            0 :                         guc_free(newextra);
    4069              : 
    4070         1812 :                     if (*conf->variable != newval)
    4071              :                     {
    4072            0 :                         record->status |= GUC_PENDING_RESTART;
    4073            0 :                         ereport(elevel,
    4074              :                                 (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    4075              :                                  errmsg("parameter \"%s\" cannot be changed without restarting the server",
    4076              :                                         record->name)));
    4077            0 :                         return 0;
    4078              :                     }
    4079         1812 :                     record->status &= ~GUC_PENDING_RESTART;
    4080         1812 :                     return -1;
    4081              :                 }
    4082              : 
    4083        36952 :                 if (changeVal)
    4084              :                 {
    4085              :                     /* Save old value to support transaction abort */
    4086        36838 :                     if (!makeDefault)
    4087        10541 :                         push_old_value(record, action);
    4088              : 
    4089        36838 :                     if (conf->assign_hook)
    4090         5560 :                         conf->assign_hook(newval, newextra);
    4091        36838 :                     *conf->variable = newval;
    4092        36838 :                     set_extra_field(record, &record->extra,
    4093              :                                     newextra);
    4094        36838 :                     set_guc_source(record, source);
    4095        36838 :                     record->scontext = context;
    4096        36838 :                     record->srole = srole;
    4097              :                 }
    4098        36952 :                 if (makeDefault)
    4099              :                 {
    4100        26297 :                     if (record->reset_source <= source)
    4101              :                     {
    4102        26297 :                         conf->reset_val = newval;
    4103        26297 :                         set_extra_field(record, &record->reset_extra,
    4104              :                                         newextra);
    4105        26297 :                         record->reset_source = source;
    4106        26297 :                         record->reset_scontext = context;
    4107        26297 :                         record->reset_srole = srole;
    4108              :                     }
    4109        26297 :                     for (GucStack *stack = record->stack; stack; stack = stack->prev)
    4110              :                     {
    4111            0 :                         if (stack->source <= source)
    4112              :                         {
    4113            0 :                             stack->prior.val.enumval = newval;
    4114            0 :                             set_extra_field(record, &stack->prior.extra,
    4115              :                                             newextra);
    4116            0 :                             stack->source = source;
    4117            0 :                             stack->scontext = context;
    4118            0 :                             stack->srole = srole;
    4119              :                         }
    4120              :                     }
    4121              :                 }
    4122              : 
    4123              :                 /* Perhaps we didn't install newextra anywhere */
    4124        36952 :                 if (newextra && !extra_field_used(record, newextra))
    4125            0 :                     guc_free(newextra);
    4126        36952 :                 break;
    4127              : 
    4128              : #undef newval
    4129              :             }
    4130              :     }
    4131              : 
    4132       540209 :     if (changeVal && (record->flags & GUC_REPORT) &&
    4133       341272 :         !(record->status & GUC_NEEDS_REPORT))
    4134              :     {
    4135       134097 :         record->status |= GUC_NEEDS_REPORT;
    4136       134097 :         slist_push_head(&guc_report_list, &record->report_link);
    4137              :     }
    4138              : 
    4139       540209 :     return changeVal ? 1 : -1;
    4140              : }
    4141              : 
    4142              : 
    4143              : /*
    4144              :  * Retrieve a config_handle for the given name, suitable for calling
    4145              :  * set_config_with_handle(). Only return handle to permanent GUC.
    4146              :  */
    4147              : config_handle *
    4148           66 : get_config_handle(const char *name)
    4149              : {
    4150           66 :     struct config_generic *gen = find_option(name, false, false, 0);
    4151              : 
    4152           66 :     if (gen && ((gen->flags & GUC_CUSTOM_PLACEHOLDER) == 0))
    4153           66 :         return gen;
    4154              : 
    4155            0 :     return NULL;
    4156              : }
    4157              : 
    4158              : 
    4159              : /*
    4160              :  * Set the fields for source file and line number the setting came from.
    4161              :  */
    4162              : static void
    4163        78294 : set_config_sourcefile(const char *name, char *sourcefile, int sourceline)
    4164              : {
    4165              :     struct config_generic *record;
    4166              :     int         elevel;
    4167              : 
    4168              :     /*
    4169              :      * To avoid cluttering the log, only the postmaster bleats loudly about
    4170              :      * problems with the config file.
    4171              :      */
    4172        78294 :     elevel = IsUnderPostmaster ? DEBUG3 : LOG;
    4173              : 
    4174        78294 :     record = find_option(name, true, false, elevel);
    4175              :     /* should not happen */
    4176        78294 :     if (record == NULL)
    4177            0 :         return;
    4178              : 
    4179        78294 :     sourcefile = guc_strdup(elevel, sourcefile);
    4180        78294 :     guc_free(record->sourcefile);
    4181        78294 :     record->sourcefile = sourcefile;
    4182        78294 :     record->sourceline = sourceline;
    4183              : }
    4184              : 
    4185              : /*
    4186              :  * Set a config option to the given value.
    4187              :  *
    4188              :  * See also set_config_option; this is just the wrapper to be called from
    4189              :  * outside GUC.  (This function should be used when possible, because its API
    4190              :  * is more stable than set_config_option's.)
    4191              :  *
    4192              :  * Note: there is no support here for setting source file/line, as it
    4193              :  * is currently not needed.
    4194              :  */
    4195              : void
    4196       170863 : SetConfigOption(const char *name, const char *value,
    4197              :                 GucContext context, GucSource source)
    4198              : {
    4199       170863 :     (void) set_config_option(name, value, context, source,
    4200              :                              GUC_ACTION_SET, true, 0, false);
    4201       170838 : }
    4202              : 
    4203              : 
    4204              : 
    4205              : /*
    4206              :  * Fetch the current value of the option `name', as a string.
    4207              :  *
    4208              :  * If the option doesn't exist, return NULL if missing_ok is true,
    4209              :  * otherwise throw an ereport and don't return.
    4210              :  *
    4211              :  * If restrict_privileged is true, we also enforce that only superusers and
    4212              :  * members of the pg_read_all_settings role can see GUC_SUPERUSER_ONLY
    4213              :  * variables.  This should only be passed as true in user-driven calls.
    4214              :  *
    4215              :  * The string is *not* allocated for modification and is really only
    4216              :  * valid until the next call to configuration related functions.
    4217              :  */
    4218              : const char *
    4219         7399 : GetConfigOption(const char *name, bool missing_ok, bool restrict_privileged)
    4220              : {
    4221              :     struct config_generic *record;
    4222              :     static char buffer[256];
    4223              : 
    4224         7399 :     record = find_option(name, false, missing_ok, ERROR);
    4225         7399 :     if (record == NULL)
    4226            1 :         return NULL;
    4227         7398 :     if (restrict_privileged &&
    4228            0 :         !ConfigOptionIsVisible(record))
    4229            0 :         ereport(ERROR,
    4230              :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    4231              :                  errmsg("permission denied to examine \"%s\"", name),
    4232              :                  errdetail("Only roles with privileges of the \"%s\" role may examine this parameter.",
    4233              :                            "pg_read_all_settings")));
    4234              : 
    4235         7398 :     switch (record->vartype)
    4236              :     {
    4237         1250 :         case PGC_BOOL:
    4238         1250 :             return *record->_bool.variable ? "on" : "off";
    4239              : 
    4240         1923 :         case PGC_INT:
    4241         1923 :             snprintf(buffer, sizeof(buffer), "%d",
    4242         1923 :                      *record->_int.variable);
    4243         1923 :             return buffer;
    4244              : 
    4245            0 :         case PGC_REAL:
    4246            0 :             snprintf(buffer, sizeof(buffer), "%g",
    4247            0 :                      *record->_real.variable);
    4248            0 :             return buffer;
    4249              : 
    4250         3566 :         case PGC_STRING:
    4251         3566 :             return *record->_string.variable ?
    4252         3566 :                 *record->_string.variable : "";
    4253              : 
    4254          659 :         case PGC_ENUM:
    4255          659 :             return config_enum_lookup_by_value(record,
    4256          659 :                                                *record->_enum.variable);
    4257              :     }
    4258            0 :     return NULL;
    4259              : }
    4260              : 
    4261              : /*
    4262              :  * Get the RESET value associated with the given option.
    4263              :  *
    4264              :  * Note: this is not re-entrant, due to use of static result buffer;
    4265              :  * not to mention that a string variable could have its reset_val changed.
    4266              :  * Beware of assuming the result value is good for very long.
    4267              :  */
    4268              : const char *
    4269            0 : GetConfigOptionResetString(const char *name)
    4270              : {
    4271              :     struct config_generic *record;
    4272              :     static char buffer[256];
    4273              : 
    4274            0 :     record = find_option(name, false, false, ERROR);
    4275              :     Assert(record != NULL);
    4276            0 :     if (!ConfigOptionIsVisible(record))
    4277            0 :         ereport(ERROR,
    4278              :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    4279              :                  errmsg("permission denied to examine \"%s\"", name),
    4280              :                  errdetail("Only roles with privileges of the \"%s\" role may examine this parameter.",
    4281              :                            "pg_read_all_settings")));
    4282              : 
    4283            0 :     switch (record->vartype)
    4284              :     {
    4285            0 :         case PGC_BOOL:
    4286            0 :             return record->_bool.reset_val ? "on" : "off";
    4287              : 
    4288            0 :         case PGC_INT:
    4289            0 :             snprintf(buffer, sizeof(buffer), "%d",
    4290              :                      record->_int.reset_val);
    4291            0 :             return buffer;
    4292              : 
    4293            0 :         case PGC_REAL:
    4294            0 :             snprintf(buffer, sizeof(buffer), "%g",
    4295              :                      record->_real.reset_val);
    4296            0 :             return buffer;
    4297              : 
    4298            0 :         case PGC_STRING:
    4299            0 :             return record->_string.reset_val ?
    4300            0 :                 record->_string.reset_val : "";
    4301              : 
    4302            0 :         case PGC_ENUM:
    4303            0 :             return config_enum_lookup_by_value(record,
    4304              :                                                record->_enum.reset_val);
    4305              :     }
    4306            0 :     return NULL;
    4307              : }
    4308              : 
    4309              : /*
    4310              :  * Get the GUC flags associated with the given option.
    4311              :  *
    4312              :  * If the option doesn't exist, return 0 if missing_ok is true,
    4313              :  * otherwise throw an ereport and don't return.
    4314              :  */
    4315              : int
    4316           20 : GetConfigOptionFlags(const char *name, bool missing_ok)
    4317              : {
    4318              :     struct config_generic *record;
    4319              : 
    4320           20 :     record = find_option(name, false, missing_ok, ERROR);
    4321           20 :     if (record == NULL)
    4322            0 :         return 0;
    4323           20 :     return record->flags;
    4324              : }
    4325              : 
    4326              : 
    4327              : /*
    4328              :  * Write updated configuration parameter values into a temporary file.
    4329              :  * This function traverses the list of parameters and quotes the string
    4330              :  * values before writing them.
    4331              :  */
    4332              : static void
    4333           83 : write_auto_conf_file(int fd, const char *filename, ConfigVariable *head)
    4334              : {
    4335              :     StringInfoData buf;
    4336              : 
    4337           83 :     initStringInfo(&buf);
    4338              : 
    4339              :     /* Emit file header containing warning comment */
    4340           83 :     appendStringInfoString(&buf, "# Do not edit this file manually!\n");
    4341           83 :     appendStringInfoString(&buf, "# It will be overwritten by the ALTER SYSTEM command.\n");
    4342              : 
    4343           83 :     errno = 0;
    4344           83 :     if (write(fd, buf.data, buf.len) != buf.len)
    4345              :     {
    4346              :         /* if write didn't set errno, assume problem is no disk space */
    4347            0 :         if (errno == 0)
    4348            0 :             errno = ENOSPC;
    4349            0 :         ereport(ERROR,
    4350              :                 (errcode_for_file_access(),
    4351              :                  errmsg("could not write to file \"%s\": %m", filename)));
    4352              :     }
    4353              : 
    4354              :     /* Emit each parameter, properly quoting the value */
    4355          179 :     for (ConfigVariable *item = head; item != NULL; item = item->next)
    4356              :     {
    4357              :         char       *escaped;
    4358              : 
    4359           96 :         resetStringInfo(&buf);
    4360              : 
    4361           96 :         appendStringInfoString(&buf, item->name);
    4362           96 :         appendStringInfoString(&buf, " = '");
    4363              : 
    4364           96 :         escaped = escape_single_quotes_ascii(item->value);
    4365           96 :         if (!escaped)
    4366            0 :             ereport(ERROR,
    4367              :                     (errcode(ERRCODE_OUT_OF_MEMORY),
    4368              :                      errmsg("out of memory")));
    4369           96 :         appendStringInfoString(&buf, escaped);
    4370           96 :         free(escaped);
    4371              : 
    4372           96 :         appendStringInfoString(&buf, "'\n");
    4373              : 
    4374           96 :         errno = 0;
    4375           96 :         if (write(fd, buf.data, buf.len) != buf.len)
    4376              :         {
    4377              :             /* if write didn't set errno, assume problem is no disk space */
    4378            0 :             if (errno == 0)
    4379            0 :                 errno = ENOSPC;
    4380            0 :             ereport(ERROR,
    4381              :                     (errcode_for_file_access(),
    4382              :                      errmsg("could not write to file \"%s\": %m", filename)));
    4383              :         }
    4384              :     }
    4385              : 
    4386              :     /* fsync before considering the write to be successful */
    4387           83 :     if (pg_fsync(fd) != 0)
    4388            0 :         ereport(ERROR,
    4389              :                 (errcode_for_file_access(),
    4390              :                  errmsg("could not fsync file \"%s\": %m", filename)));
    4391              : 
    4392           83 :     pfree(buf.data);
    4393           83 : }
    4394              : 
    4395              : /*
    4396              :  * Update the given list of configuration parameters, adding, replacing
    4397              :  * or deleting the entry for item "name" (delete if "value" == NULL).
    4398              :  */
    4399              : static void
    4400           83 : replace_auto_config_value(ConfigVariable **head_p, ConfigVariable **tail_p,
    4401              :                           const char *name, const char *value)
    4402              : {
    4403              :     ConfigVariable *newitem,
    4404              :                *next,
    4405           83 :                *prev = NULL;
    4406              : 
    4407              :     /*
    4408              :      * Remove any existing match(es) for "name".  Normally there'd be at most
    4409              :      * one, but if external tools have modified the config file, there could
    4410              :      * be more.
    4411              :      */
    4412          161 :     for (ConfigVariable *item = *head_p; item != NULL; item = next)
    4413              :     {
    4414           78 :         next = item->next;
    4415           78 :         if (guc_name_compare(item->name, name) == 0)
    4416              :         {
    4417              :             /* found a match, delete it */
    4418           43 :             if (prev)
    4419            6 :                 prev->next = next;
    4420              :             else
    4421           37 :                 *head_p = next;
    4422           43 :             if (next == NULL)
    4423           40 :                 *tail_p = prev;
    4424              : 
    4425           43 :             pfree(item->name);
    4426           43 :             pfree(item->value);
    4427           43 :             pfree(item->filename);
    4428           43 :             pfree(item);
    4429              :         }
    4430              :         else
    4431           35 :             prev = item;
    4432              :     }
    4433              : 
    4434              :     /* Done if we're trying to delete it */
    4435           83 :     if (value == NULL)
    4436           22 :         return;
    4437              : 
    4438              :     /* OK, append a new entry */
    4439           61 :     newitem = palloc_object(ConfigVariable);
    4440           61 :     newitem->name = pstrdup(name);
    4441           61 :     newitem->value = pstrdup(value);
    4442           61 :     newitem->errmsg = NULL;
    4443           61 :     newitem->filename = pstrdup("");   /* new item has no location */
    4444           61 :     newitem->sourceline = 0;
    4445           61 :     newitem->ignore = false;
    4446           61 :     newitem->applied = false;
    4447           61 :     newitem->next = NULL;
    4448              : 
    4449           61 :     if (*head_p == NULL)
    4450           47 :         *head_p = newitem;
    4451              :     else
    4452           14 :         (*tail_p)->next = newitem;
    4453           61 :     *tail_p = newitem;
    4454              : }
    4455              : 
    4456              : 
    4457              : /*
    4458              :  * Execute ALTER SYSTEM statement.
    4459              :  *
    4460              :  * Read the old PG_AUTOCONF_FILENAME file, merge in the new variable value,
    4461              :  * and write out an updated file.  If the command is ALTER SYSTEM RESET ALL,
    4462              :  * we can skip reading the old file and just write an empty file.
    4463              :  *
    4464              :  * An LWLock is used to serialize updates of the configuration file.
    4465              :  *
    4466              :  * In case of an error, we leave the original automatic
    4467              :  * configuration file (PG_AUTOCONF_FILENAME) intact.
    4468              :  */
    4469              : void
    4470          113 : AlterSystemSetConfigFile(AlterSystemStmt *altersysstmt)
    4471              : {
    4472              :     char       *name;
    4473              :     char       *value;
    4474          113 :     bool        resetall = false;
    4475          113 :     ConfigVariable *head = NULL;
    4476          113 :     ConfigVariable *tail = NULL;
    4477              :     volatile int Tmpfd;
    4478              :     char        AutoConfFileName[MAXPGPATH];
    4479              :     char        AutoConfTmpFileName[MAXPGPATH];
    4480              : 
    4481              :     /*
    4482              :      * Extract statement arguments
    4483              :      */
    4484          113 :     name = altersysstmt->setstmt->name;
    4485              : 
    4486          113 :     if (!AllowAlterSystem)
    4487            0 :         ereport(ERROR,
    4488              :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    4489              :                  errmsg("ALTER SYSTEM is not allowed in this environment")));
    4490              : 
    4491          113 :     switch (altersysstmt->setstmt->kind)
    4492              :     {
    4493           84 :         case VAR_SET_VALUE:
    4494           84 :             value = ExtractSetVariableArgs(altersysstmt->setstmt);
    4495           84 :             break;
    4496              : 
    4497           28 :         case VAR_SET_DEFAULT:
    4498              :         case VAR_RESET:
    4499           28 :             value = NULL;
    4500           28 :             break;
    4501              : 
    4502            1 :         case VAR_RESET_ALL:
    4503            1 :             value = NULL;
    4504            1 :             resetall = true;
    4505            1 :             break;
    4506              : 
    4507            0 :         default:
    4508            0 :             elog(ERROR, "unrecognized alter system stmt type: %d",
    4509              :                  altersysstmt->setstmt->kind);
    4510              :             break;
    4511              :     }
    4512              : 
    4513              :     /*
    4514              :      * Check permission to run ALTER SYSTEM on the target variable
    4515              :      */
    4516          113 :     if (!superuser())
    4517              :     {
    4518           23 :         if (resetall)
    4519            1 :             ereport(ERROR,
    4520              :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    4521              :                      errmsg("permission denied to perform ALTER SYSTEM RESET ALL")));
    4522              :         else
    4523              :         {
    4524              :             AclResult   aclresult;
    4525              : 
    4526           22 :             aclresult = pg_parameter_aclcheck(name, GetUserId(),
    4527              :                                               ACL_ALTER_SYSTEM);
    4528           22 :             if (aclresult != ACLCHECK_OK)
    4529           13 :                 ereport(ERROR,
    4530              :                         (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    4531              :                          errmsg("permission denied to set parameter \"%s\"",
    4532              :                                 name)));
    4533              :         }
    4534              :     }
    4535              : 
    4536              :     /*
    4537              :      * Unless it's RESET_ALL, validate the target variable and value
    4538              :      */
    4539           99 :     if (!resetall)
    4540              :     {
    4541              :         struct config_generic *record;
    4542              : 
    4543              :         /* We don't want to create a placeholder if there's not one already */
    4544           99 :         record = find_option(name, false, true, DEBUG5);
    4545           99 :         if (record != NULL)
    4546              :         {
    4547              :             /*
    4548              :              * Don't allow parameters that can't be set in configuration files
    4549              :              * to be set in PG_AUTOCONF_FILENAME file.
    4550              :              */
    4551           97 :             if ((record->context == PGC_INTERNAL) ||
    4552           95 :                 (record->flags & GUC_DISALLOW_IN_FILE) ||
    4553           91 :                 (record->flags & GUC_DISALLOW_IN_AUTO_FILE))
    4554            6 :                 ereport(ERROR,
    4555              :                         (errcode(ERRCODE_CANT_CHANGE_RUNTIME_PARAM),
    4556              :                          errmsg("parameter \"%s\" cannot be changed",
    4557              :                                 name)));
    4558              : 
    4559              :             /*
    4560              :              * If a value is specified, verify that it's sane.
    4561              :              */
    4562           91 :             if (value)
    4563              :             {
    4564              :                 union config_var_val newval;
    4565           70 :                 void       *newextra = NULL;
    4566              : 
    4567           70 :                 if (!parse_and_validate_value(record, value,
    4568              :                                               PGC_S_FILE, ERROR,
    4569              :                                               &newval, &newextra))
    4570            0 :                     ereport(ERROR,
    4571              :                             (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    4572              :                              errmsg("invalid value for parameter \"%s\": \"%s\"",
    4573              :                                     name, value)));
    4574              : 
    4575           60 :                 if (record->vartype == PGC_STRING && newval.stringval != NULL)
    4576           31 :                     guc_free(newval.stringval);
    4577           60 :                 guc_free(newextra);
    4578              :             }
    4579              :         }
    4580              :         else
    4581              :         {
    4582              :             /*
    4583              :              * Variable not known; check we'd be allowed to create it.  (We
    4584              :              * cannot validate the value, but that's fine.  A non-core GUC in
    4585              :              * the config file cannot cause postmaster start to fail, so we
    4586              :              * don't have to be too tense about possibly installing a bad
    4587              :              * value.)
    4588              :              *
    4589              :              * As an exception, we skip this check if this is a RESET command
    4590              :              * for an unknown custom GUC, else there'd be no way for users to
    4591              :              * remove such settings with reserved prefixes.
    4592              :              */
    4593            2 :             if (value || !valid_custom_variable_name(name))
    4594            1 :                 (void) assignable_custom_variable_name(name, false, ERROR);
    4595              :         }
    4596              : 
    4597              :         /*
    4598              :          * We must also reject values containing newlines, because the grammar
    4599              :          * for config files doesn't support embedded newlines in string
    4600              :          * literals.
    4601              :          */
    4602           83 :         if (value && strchr(value, '\n'))
    4603            0 :             ereport(ERROR,
    4604              :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    4605              :                      errmsg("parameter value for ALTER SYSTEM must not contain a newline")));
    4606              :     }
    4607              : 
    4608              :     /*
    4609              :      * PG_AUTOCONF_FILENAME and its corresponding temporary file are always in
    4610              :      * the data directory, so we can reference them by simple relative paths.
    4611              :      */
    4612           83 :     snprintf(AutoConfFileName, sizeof(AutoConfFileName), "%s",
    4613              :              PG_AUTOCONF_FILENAME);
    4614           83 :     snprintf(AutoConfTmpFileName, sizeof(AutoConfTmpFileName), "%s.%s",
    4615              :              AutoConfFileName,
    4616              :              "tmp");
    4617              : 
    4618              :     /*
    4619              :      * Only one backend is allowed to operate on PG_AUTOCONF_FILENAME at a
    4620              :      * time.  Use AutoFileLock to ensure that.  We must hold the lock while
    4621              :      * reading the old file contents.
    4622              :      */
    4623           83 :     LWLockAcquire(AutoFileLock, LW_EXCLUSIVE);
    4624              : 
    4625              :     /*
    4626              :      * If we're going to reset everything, then no need to open or parse the
    4627              :      * old file.  We'll just write out an empty list.
    4628              :      */
    4629           83 :     if (!resetall)
    4630              :     {
    4631              :         struct stat st;
    4632              : 
    4633           83 :         if (stat(AutoConfFileName, &st) == 0)
    4634              :         {
    4635              :             /* open old file PG_AUTOCONF_FILENAME */
    4636              :             FILE       *infile;
    4637              : 
    4638           83 :             infile = AllocateFile(AutoConfFileName, "r");
    4639           83 :             if (infile == NULL)
    4640            0 :                 ereport(ERROR,
    4641              :                         (errcode_for_file_access(),
    4642              :                          errmsg("could not open file \"%s\": %m",
    4643              :                                 AutoConfFileName)));
    4644              : 
    4645              :             /* parse it */
    4646           83 :             if (!ParseConfigFp(infile, AutoConfFileName, CONF_FILE_START_DEPTH,
    4647              :                                LOG, &head, &tail))
    4648            0 :                 ereport(ERROR,
    4649              :                         (errcode(ERRCODE_CONFIG_FILE_ERROR),
    4650              :                          errmsg("could not parse contents of file \"%s\"",
    4651              :                                 AutoConfFileName)));
    4652              : 
    4653           83 :             FreeFile(infile);
    4654              :         }
    4655              : 
    4656              :         /*
    4657              :          * Now, replace any existing entry with the new value, or add it if
    4658              :          * not present.
    4659              :          */
    4660           83 :         replace_auto_config_value(&head, &tail, name, value);
    4661              :     }
    4662              : 
    4663              :     /*
    4664              :      * Invoke the post-alter hook for setting this GUC variable.  GUCs
    4665              :      * typically do not have corresponding entries in pg_parameter_acl, so we
    4666              :      * call the hook using the name rather than a potentially-non-existent
    4667              :      * OID.  Nonetheless, we pass ParameterAclRelationId so that this call
    4668              :      * context can be distinguished from others.  (Note that "name" will be
    4669              :      * NULL in the RESET ALL case.)
    4670              :      *
    4671              :      * We do this here rather than at the end, because ALTER SYSTEM is not
    4672              :      * transactional.  If the hook aborts our transaction, it will be cleaner
    4673              :      * to do so before we touch any files.
    4674              :      */
    4675           83 :     InvokeObjectPostAlterHookArgStr(ParameterAclRelationId, name,
    4676              :                                     ACL_ALTER_SYSTEM,
    4677              :                                     altersysstmt->setstmt->kind,
    4678              :                                     false);
    4679              : 
    4680              :     /*
    4681              :      * To ensure crash safety, first write the new file data to a temp file,
    4682              :      * then atomically rename it into place.
    4683              :      *
    4684              :      * If there is a temp file left over due to a previous crash, it's okay to
    4685              :      * truncate and reuse it.
    4686              :      */
    4687           83 :     Tmpfd = BasicOpenFile(AutoConfTmpFileName,
    4688              :                           O_CREAT | O_RDWR | O_TRUNC);
    4689           83 :     if (Tmpfd < 0)
    4690            0 :         ereport(ERROR,
    4691              :                 (errcode_for_file_access(),
    4692              :                  errmsg("could not open file \"%s\": %m",
    4693              :                         AutoConfTmpFileName)));
    4694              : 
    4695              :     /*
    4696              :      * Use a TRY block to clean up the file if we fail.  Since we need a TRY
    4697              :      * block anyway, OK to use BasicOpenFile rather than OpenTransientFile.
    4698              :      */
    4699           83 :     PG_TRY();
    4700              :     {
    4701              :         /* Write and sync the new contents to the temporary file */
    4702           83 :         write_auto_conf_file(Tmpfd, AutoConfTmpFileName, head);
    4703              : 
    4704              :         /* Close before renaming; may be required on some platforms */
    4705           83 :         close(Tmpfd);
    4706           83 :         Tmpfd = -1;
    4707              : 
    4708              :         /*
    4709              :          * As the rename is atomic operation, if any problem occurs after this
    4710              :          * at worst it can lose the parameters set by last ALTER SYSTEM
    4711              :          * command.
    4712              :          */
    4713           83 :         durable_rename(AutoConfTmpFileName, AutoConfFileName, ERROR);
    4714              :     }
    4715            0 :     PG_CATCH();
    4716              :     {
    4717              :         /* Close file first, else unlink might fail on some platforms */
    4718            0 :         if (Tmpfd >= 0)
    4719            0 :             close(Tmpfd);
    4720              : 
    4721              :         /* Unlink, but ignore any error */
    4722            0 :         (void) unlink(AutoConfTmpFileName);
    4723              : 
    4724            0 :         PG_RE_THROW();
    4725              :     }
    4726           83 :     PG_END_TRY();
    4727              : 
    4728           83 :     FreeConfigVariables(head);
    4729              : 
    4730           83 :     LWLockRelease(AutoFileLock);
    4731           83 : }
    4732              : 
    4733              : 
    4734              : /*
    4735              :  * Common code for DefineCustomXXXVariable subroutines: allocate the
    4736              :  * new variable's config struct and fill in generic fields.
    4737              :  */
    4738              : static struct config_generic *
    4739         9659 : init_custom_variable(const char *name,
    4740              :                      const char *short_desc,
    4741              :                      const char *long_desc,
    4742              :                      GucContext context,
    4743              :                      int flags,
    4744              :                      enum config_type type)
    4745              : {
    4746              :     struct config_generic *gen;
    4747              : 
    4748              :     /*
    4749              :      * Only allow custom PGC_POSTMASTER variables to be created during shared
    4750              :      * library preload; any later than that, we can't ensure that the value
    4751              :      * doesn't change after startup.  This is a fatal elog if it happens; just
    4752              :      * erroring out isn't safe because we don't know what the calling loadable
    4753              :      * module might already have hooked into.
    4754              :      */
    4755         9659 :     if (context == PGC_POSTMASTER &&
    4756           10 :         !process_shared_preload_libraries_in_progress)
    4757            0 :         elog(FATAL, "cannot create PGC_POSTMASTER variables after startup");
    4758              : 
    4759              :     /*
    4760              :      * We can't support custom GUC_LIST_QUOTE variables, because the wrong
    4761              :      * things would happen if such a variable were set or pg_dump'd when the
    4762              :      * defining extension isn't loaded.  Again, treat this as fatal because
    4763              :      * the loadable module may be partly initialized already.
    4764              :      */
    4765         9659 :     if (flags & GUC_LIST_QUOTE)
    4766            0 :         elog(FATAL, "extensions cannot define GUC_LIST_QUOTE variables");
    4767              : 
    4768              :     /*
    4769              :      * Before pljava commit 398f3b876ed402bdaec8bc804f29e2be95c75139
    4770              :      * (2015-12-15), two of that module's PGC_USERSET variables facilitated
    4771              :      * trivial escalation to superuser privileges.  Restrict the variables to
    4772              :      * protect sites that have yet to upgrade pljava.
    4773              :      */
    4774         9659 :     if (context == PGC_USERSET &&
    4775         7412 :         (strcmp(name, "pljava.classpath") == 0 ||
    4776         7412 :          strcmp(name, "pljava.vmoptions") == 0))
    4777            0 :         context = PGC_SUSET;
    4778              : 
    4779              :     /* As above, an OOM here is FATAL */
    4780         9659 :     gen = (struct config_generic *) guc_malloc(FATAL, sizeof(struct config_generic));
    4781         9659 :     memset(gen, 0, sizeof(struct config_generic));
    4782              : 
    4783         9659 :     gen->name = guc_strdup(FATAL, name);
    4784         9659 :     gen->context = context;
    4785         9659 :     gen->group = CUSTOM_OPTIONS;
    4786         9659 :     gen->short_desc = short_desc;
    4787         9659 :     gen->long_desc = long_desc;
    4788         9659 :     gen->flags = flags;
    4789         9659 :     gen->vartype = type;
    4790              : 
    4791         9659 :     return gen;
    4792              : }
    4793              : 
    4794              : /*
    4795              :  * Common code for DefineCustomXXXVariable subroutines: insert the new
    4796              :  * variable into the GUC variable hash, replacing any placeholder.
    4797              :  */
    4798              : static void
    4799         9659 : define_custom_variable(struct config_generic *variable)
    4800              : {
    4801         9659 :     const char *name = variable->name;
    4802              :     GUCHashEntry *hentry;
    4803              :     struct config_generic *pHolder;
    4804              : 
    4805              :     /* Check mapping between initial and default value */
    4806              :     Assert(check_GUC_init(variable));
    4807              : 
    4808              :     /*
    4809              :      * See if there's a placeholder by the same name.
    4810              :      */
    4811         9659 :     hentry = (GUCHashEntry *) hash_search(guc_hashtab,
    4812              :                                           &name,
    4813              :                                           HASH_FIND,
    4814              :                                           NULL);
    4815         9659 :     if (hentry == NULL)
    4816              :     {
    4817              :         /*
    4818              :          * No placeholder to replace, so we can just add it ... but first,
    4819              :          * make sure it's initialized to its default value.
    4820              :          */
    4821         9608 :         InitializeOneGUCOption(variable);
    4822         9608 :         add_guc_variable(variable, ERROR);
    4823         9608 :         return;
    4824              :     }
    4825              : 
    4826              :     /*
    4827              :      * This better be a placeholder
    4828              :      */
    4829           51 :     if ((hentry->gucvar->flags & GUC_CUSTOM_PLACEHOLDER) == 0)
    4830            0 :         ereport(ERROR,
    4831              :                 (errcode(ERRCODE_INTERNAL_ERROR),
    4832              :                  errmsg("attempt to redefine parameter \"%s\"", name)));
    4833              : 
    4834              :     Assert(hentry->gucvar->vartype == PGC_STRING);
    4835           51 :     pHolder = hentry->gucvar;
    4836              : 
    4837              :     /*
    4838              :      * First, set the variable to its default value.  We must do this even
    4839              :      * though we intend to immediately apply a new value, since it's possible
    4840              :      * that the new value is invalid.
    4841              :      */
    4842           51 :     InitializeOneGUCOption(variable);
    4843              : 
    4844              :     /*
    4845              :      * Replace the placeholder in the hash table.  We aren't changing the name
    4846              :      * (at least up to case-folding), so the hash value is unchanged.
    4847              :      */
    4848           51 :     hentry->gucname = name;
    4849           51 :     hentry->gucvar = variable;
    4850              : 
    4851              :     /*
    4852              :      * Remove the placeholder from any lists it's in, too.
    4853              :      */
    4854           51 :     RemoveGUCFromLists(pHolder);
    4855              : 
    4856              :     /*
    4857              :      * Assign the string value(s) stored in the placeholder to the real
    4858              :      * variable.  Essentially, we need to duplicate all the active and stacked
    4859              :      * values, but with appropriate validation and datatype adjustment.
    4860              :      *
    4861              :      * If an assignment fails, we report a WARNING and keep going.  We don't
    4862              :      * want to throw ERROR for bad values, because it'd bollix the add-on
    4863              :      * module that's presumably halfway through getting loaded.  In such cases
    4864              :      * the default or previous state will become active instead.
    4865              :      */
    4866              : 
    4867              :     /* First, apply the reset value if any */
    4868           51 :     if (pHolder->_string.reset_val)
    4869           48 :         (void) set_config_option_ext(name, pHolder->_string.reset_val,
    4870              :                                      pHolder->reset_scontext,
    4871              :                                      pHolder->reset_source,
    4872              :                                      pHolder->reset_srole,
    4873              :                                      GUC_ACTION_SET, true, WARNING, false);
    4874              :     /* That should not have resulted in stacking anything */
    4875              :     Assert(variable->stack == NULL);
    4876              : 
    4877              :     /* Now, apply current and stacked values, in the order they were stacked */
    4878           51 :     reapply_stacked_values(variable, pHolder, pHolder->stack,
    4879           51 :                            *(pHolder->_string.variable),
    4880              :                            pHolder->scontext, pHolder->source,
    4881              :                            pHolder->srole);
    4882              : 
    4883              :     /* Also copy over any saved source-location information */
    4884           51 :     if (pHolder->sourcefile)
    4885           40 :         set_config_sourcefile(name, pHolder->sourcefile,
    4886              :                               pHolder->sourceline);
    4887              : 
    4888              :     /* Now we can free the no-longer-referenced placeholder variable */
    4889           51 :     free_placeholder(pHolder);
    4890              : }
    4891              : 
    4892              : /*
    4893              :  * Recursive subroutine for define_custom_variable: reapply non-reset values
    4894              :  *
    4895              :  * We recurse so that the values are applied in the same order as originally.
    4896              :  * At each recursion level, apply the upper-level value (passed in) in the
    4897              :  * fashion implied by the stack entry.
    4898              :  */
    4899              : static void
    4900           51 : reapply_stacked_values(struct config_generic *variable,
    4901              :                        struct config_generic *pHolder,
    4902              :                        GucStack *stack,
    4903              :                        const char *curvalue,
    4904              :                        GucContext curscontext, GucSource cursource,
    4905              :                        Oid cursrole)
    4906              : {
    4907           51 :     const char *name = variable->name;
    4908           51 :     GucStack   *oldvarstack = variable->stack;
    4909              : 
    4910           51 :     if (stack != NULL)
    4911              :     {
    4912              :         /* First, recurse, so that stack items are processed bottom to top */
    4913            0 :         reapply_stacked_values(variable, pHolder, stack->prev,
    4914            0 :                                stack->prior.val.stringval,
    4915              :                                stack->scontext, stack->source, stack->srole);
    4916              : 
    4917              :         /* See how to apply the passed-in value */
    4918            0 :         switch (stack->state)
    4919              :         {
    4920            0 :             case GUC_SAVE:
    4921            0 :                 (void) set_config_option_ext(name, curvalue,
    4922              :                                              curscontext, cursource, cursrole,
    4923              :                                              GUC_ACTION_SAVE, true,
    4924              :                                              WARNING, false);
    4925            0 :                 break;
    4926              : 
    4927            0 :             case GUC_SET:
    4928            0 :                 (void) set_config_option_ext(name, curvalue,
    4929              :                                              curscontext, cursource, cursrole,
    4930              :                                              GUC_ACTION_SET, true,
    4931              :                                              WARNING, false);
    4932            0 :                 break;
    4933              : 
    4934            0 :             case GUC_LOCAL:
    4935            0 :                 (void) set_config_option_ext(name, curvalue,
    4936              :                                              curscontext, cursource, cursrole,
    4937              :                                              GUC_ACTION_LOCAL, true,
    4938              :                                              WARNING, false);
    4939            0 :                 break;
    4940              : 
    4941            0 :             case GUC_SET_LOCAL:
    4942              :                 /* first, apply the masked value as SET */
    4943            0 :                 (void) set_config_option_ext(name, stack->masked.val.stringval,
    4944              :                                              stack->masked_scontext,
    4945              :                                              PGC_S_SESSION,
    4946              :                                              stack->masked_srole,
    4947              :                                              GUC_ACTION_SET, true,
    4948              :                                              WARNING, false);
    4949              :                 /* then apply the current value as LOCAL */
    4950            0 :                 (void) set_config_option_ext(name, curvalue,
    4951              :                                              curscontext, cursource, cursrole,
    4952              :                                              GUC_ACTION_LOCAL, true,
    4953              :                                              WARNING, false);
    4954            0 :                 break;
    4955              :         }
    4956              : 
    4957              :         /* If we successfully made a stack entry, adjust its nest level */
    4958            0 :         if (variable->stack != oldvarstack)
    4959            0 :             variable->stack->nest_level = stack->nest_level;
    4960              :     }
    4961              :     else
    4962              :     {
    4963              :         /*
    4964              :          * We are at the end of the stack.  If the active/previous value is
    4965              :          * different from the reset value, it must represent a previously
    4966              :          * committed session value.  Apply it, and then drop the stack entry
    4967              :          * that set_config_option will have created under the impression that
    4968              :          * this is to be just a transactional assignment.  (We leak the stack
    4969              :          * entry.)
    4970              :          */
    4971           51 :         if (curvalue != pHolder->_string.reset_val ||
    4972           48 :             curscontext != pHolder->reset_scontext ||
    4973           48 :             cursource != pHolder->reset_source ||
    4974           48 :             cursrole != pHolder->reset_srole)
    4975              :         {
    4976            3 :             (void) set_config_option_ext(name, curvalue,
    4977              :                                          curscontext, cursource, cursrole,
    4978              :                                          GUC_ACTION_SET, true, WARNING, false);
    4979            3 :             if (variable->stack != NULL)
    4980              :             {
    4981            2 :                 slist_delete(&guc_stack_list, &variable->stack_link);
    4982            2 :                 variable->stack = NULL;
    4983              :             }
    4984              :         }
    4985              :     }
    4986           51 : }
    4987              : 
    4988              : /*
    4989              :  * Free up a no-longer-referenced placeholder GUC variable.
    4990              :  *
    4991              :  * This neglects any stack items, so it's possible for some memory to be
    4992              :  * leaked.  Since this can only happen once per session per variable, it
    4993              :  * doesn't seem worth spending much code on.
    4994              :  */
    4995              : static void
    4996           55 : free_placeholder(struct config_generic *pHolder)
    4997              : {
    4998              :     /* Placeholders are always STRING type, so free their values */
    4999              :     Assert(pHolder->vartype == PGC_STRING);
    5000           55 :     set_string_field(pHolder, pHolder->_string.variable, NULL);
    5001           55 :     set_string_field(pHolder, &pHolder->_string.reset_val, NULL);
    5002              : 
    5003           55 :     guc_free(unconstify(char *, pHolder->name));
    5004           55 :     guc_free(pHolder);
    5005           55 : }
    5006              : 
    5007              : /*
    5008              :  * Functions for extensions to call to define their custom GUC variables.
    5009              :  */
    5010              : void
    5011         3850 : DefineCustomBoolVariable(const char *name,
    5012              :                          const char *short_desc,
    5013              :                          const char *long_desc,
    5014              :                          bool *valueAddr,
    5015              :                          bool bootValue,
    5016              :                          GucContext context,
    5017              :                          int flags,
    5018              :                          GucBoolCheckHook check_hook,
    5019              :                          GucBoolAssignHook assign_hook,
    5020              :                          GucShowHook show_hook)
    5021              : {
    5022              :     struct config_generic *var;
    5023              : 
    5024         3850 :     var = init_custom_variable(name, short_desc, long_desc, context, flags, PGC_BOOL);
    5025         3850 :     var->_bool.variable = valueAddr;
    5026         3850 :     var->_bool.boot_val = bootValue;
    5027         3850 :     var->_bool.reset_val = bootValue;
    5028         3850 :     var->_bool.check_hook = check_hook;
    5029         3850 :     var->_bool.assign_hook = assign_hook;
    5030         3850 :     var->_bool.show_hook = show_hook;
    5031         3850 :     define_custom_variable(var);
    5032         3850 : }
    5033              : 
    5034              : void
    5035           61 : DefineCustomIntVariable(const char *name,
    5036              :                         const char *short_desc,
    5037              :                         const char *long_desc,
    5038              :                         int *valueAddr,
    5039              :                         int bootValue,
    5040              :                         int minValue,
    5041              :                         int maxValue,
    5042              :                         GucContext context,
    5043              :                         int flags,
    5044              :                         GucIntCheckHook check_hook,
    5045              :                         GucIntAssignHook assign_hook,
    5046              :                         GucShowHook show_hook)
    5047              : {
    5048              :     struct config_generic *var;
    5049              : 
    5050           61 :     var = init_custom_variable(name, short_desc, long_desc, context, flags, PGC_INT);
    5051           61 :     var->_int.variable = valueAddr;
    5052           61 :     var->_int.boot_val = bootValue;
    5053           61 :     var->_int.reset_val = bootValue;
    5054           61 :     var->_int.min = minValue;
    5055           61 :     var->_int.max = maxValue;
    5056           61 :     var->_int.check_hook = check_hook;
    5057           61 :     var->_int.assign_hook = assign_hook;
    5058           61 :     var->_int.show_hook = show_hook;
    5059           61 :     define_custom_variable(var);
    5060           61 : }
    5061              : 
    5062              : void
    5063           26 : DefineCustomRealVariable(const char *name,
    5064              :                          const char *short_desc,
    5065              :                          const char *long_desc,
    5066              :                          double *valueAddr,
    5067              :                          double bootValue,
    5068              :                          double minValue,
    5069              :                          double maxValue,
    5070              :                          GucContext context,
    5071              :                          int flags,
    5072              :                          GucRealCheckHook check_hook,
    5073              :                          GucRealAssignHook assign_hook,
    5074              :                          GucShowHook show_hook)
    5075              : {
    5076              :     struct config_generic *var;
    5077              : 
    5078           26 :     var = init_custom_variable(name, short_desc, long_desc, context, flags, PGC_REAL);
    5079           26 :     var->_real.variable = valueAddr;
    5080           26 :     var->_real.boot_val = bootValue;
    5081           26 :     var->_real.reset_val = bootValue;
    5082           26 :     var->_real.min = minValue;
    5083           26 :     var->_real.max = maxValue;
    5084           26 :     var->_real.check_hook = check_hook;
    5085           26 :     var->_real.assign_hook = assign_hook;
    5086           26 :     var->_real.show_hook = show_hook;
    5087           26 :     define_custom_variable(var);
    5088           26 : }
    5089              : 
    5090              : void
    5091         3827 : DefineCustomStringVariable(const char *name,
    5092              :                            const char *short_desc,
    5093              :                            const char *long_desc,
    5094              :                            char **valueAddr,
    5095              :                            const char *bootValue,
    5096              :                            GucContext context,
    5097              :                            int flags,
    5098              :                            GucStringCheckHook check_hook,
    5099              :                            GucStringAssignHook assign_hook,
    5100              :                            GucShowHook show_hook)
    5101              : {
    5102              :     struct config_generic *var;
    5103              : 
    5104         3827 :     var = init_custom_variable(name, short_desc, long_desc, context, flags, PGC_STRING);
    5105         3827 :     var->_string.variable = valueAddr;
    5106         3827 :     var->_string.boot_val = bootValue;
    5107         3827 :     var->_string.check_hook = check_hook;
    5108         3827 :     var->_string.assign_hook = assign_hook;
    5109         3827 :     var->_string.show_hook = show_hook;
    5110         3827 :     define_custom_variable(var);
    5111         3827 : }
    5112              : 
    5113              : void
    5114         1895 : DefineCustomEnumVariable(const char *name,
    5115              :                          const char *short_desc,
    5116              :                          const char *long_desc,
    5117              :                          int *valueAddr,
    5118              :                          int bootValue,
    5119              :                          const struct config_enum_entry *options,
    5120              :                          GucContext context,
    5121              :                          int flags,
    5122              :                          GucEnumCheckHook check_hook,
    5123              :                          GucEnumAssignHook assign_hook,
    5124              :                          GucShowHook show_hook)
    5125              : {
    5126              :     struct config_generic *var;
    5127              : 
    5128         1895 :     var = init_custom_variable(name, short_desc, long_desc, context, flags, PGC_ENUM);
    5129         1895 :     var->_enum.variable = valueAddr;
    5130         1895 :     var->_enum.boot_val = bootValue;
    5131         1895 :     var->_enum.reset_val = bootValue;
    5132         1895 :     var->_enum.options = options;
    5133         1895 :     var->_enum.check_hook = check_hook;
    5134         1895 :     var->_enum.assign_hook = assign_hook;
    5135         1895 :     var->_enum.show_hook = show_hook;
    5136         1895 :     define_custom_variable(var);
    5137         1895 : }
    5138              : 
    5139              : /*
    5140              :  * Mark the given GUC prefix as "reserved".
    5141              :  *
    5142              :  * This deletes any existing placeholders matching the prefix,
    5143              :  * and then prevents new ones from being created.
    5144              :  * Extensions should call this after they've defined all of their custom
    5145              :  * GUCs, to help catch misspelled config-file entries.
    5146              :  */
    5147              : void
    5148         1970 : MarkGUCPrefixReserved(const char *className)
    5149              : {
    5150         1970 :     int         classLen = strlen(className);
    5151              :     HASH_SEQ_STATUS status;
    5152              :     GUCHashEntry *hentry;
    5153              :     MemoryContext oldcontext;
    5154              : 
    5155              :     /*
    5156              :      * Check for existing placeholders.  We must actually remove invalid
    5157              :      * placeholders, else future parallel worker startups will fail.
    5158              :      */
    5159         1970 :     hash_seq_init(&status, guc_hashtab);
    5160       827631 :     while ((hentry = (GUCHashEntry *) hash_seq_search(&status)) != NULL)
    5161              :     {
    5162       825661 :         struct config_generic *var = hentry->gucvar;
    5163              : 
    5164       825661 :         if ((var->flags & GUC_CUSTOM_PLACEHOLDER) != 0 &&
    5165           13 :             strncmp(className, var->name, classLen) == 0 &&
    5166            4 :             var->name[classLen] == GUC_QUALIFIER_SEPARATOR)
    5167              :         {
    5168            4 :             ereport(WARNING,
    5169              :                     (errcode(ERRCODE_INVALID_NAME),
    5170              :                      errmsg("invalid configuration parameter name \"%s\", removing it",
    5171              :                             var->name),
    5172              :                      errdetail("\"%s\" is now a reserved prefix.",
    5173              :                                className)));
    5174              :             /* Remove it from the hash table */
    5175            4 :             hash_search(guc_hashtab,
    5176            4 :                         &var->name,
    5177              :                         HASH_REMOVE,
    5178              :                         NULL);
    5179              :             /* Remove it from any lists it's in, too */
    5180            4 :             RemoveGUCFromLists(var);
    5181              :             /* And free it */
    5182            4 :             free_placeholder(var);
    5183              :         }
    5184              :     }
    5185              : 
    5186              :     /* And remember the name so we can prevent future mistakes. */
    5187         1970 :     oldcontext = MemoryContextSwitchTo(GUCMemoryContext);
    5188         1970 :     reserved_class_prefix = lappend(reserved_class_prefix, pstrdup(className));
    5189         1970 :     MemoryContextSwitchTo(oldcontext);
    5190         1970 : }
    5191              : 
    5192              : 
    5193              : /*
    5194              :  * Return an array of modified GUC options to show in EXPLAIN.
    5195              :  *
    5196              :  * We only report options related to query planning (marked with GUC_EXPLAIN),
    5197              :  * with values different from their built-in defaults.
    5198              :  */
    5199              : struct config_generic **
    5200            6 : get_explain_guc_options(int *num)
    5201              : {
    5202              :     struct config_generic **result;
    5203              :     dlist_iter  iter;
    5204              : 
    5205            6 :     *num = 0;
    5206              : 
    5207              :     /*
    5208              :      * While only a fraction of all the GUC variables are marked GUC_EXPLAIN,
    5209              :      * it doesn't seem worth dynamically resizing this array.
    5210              :      */
    5211            6 :     result = palloc_array(struct config_generic *, hash_get_num_entries(guc_hashtab));
    5212              : 
    5213              :     /* We need only consider GUCs with source not PGC_S_DEFAULT */
    5214          366 :     dlist_foreach(iter, &guc_nondef_list)
    5215              :     {
    5216          360 :         struct config_generic *conf = dlist_container(struct config_generic,
    5217              :                                                       nondef_link, iter.cur);
    5218              :         bool        modified;
    5219              : 
    5220              :         /* return only parameters marked for inclusion in explain */
    5221          360 :         if (!(conf->flags & GUC_EXPLAIN))
    5222          348 :             continue;
    5223              : 
    5224              :         /* return only options visible to the current user */
    5225           12 :         if (!ConfigOptionIsVisible(conf))
    5226            0 :             continue;
    5227              : 
    5228              :         /* return only options that are different from their boot values */
    5229           12 :         modified = false;
    5230              : 
    5231           12 :         switch (conf->vartype)
    5232              :         {
    5233            6 :             case PGC_BOOL:
    5234              :                 {
    5235            6 :                     struct config_bool *lconf = &conf->_bool;
    5236              : 
    5237            6 :                     modified = (lconf->boot_val != *(lconf->variable));
    5238              :                 }
    5239            6 :                 break;
    5240              : 
    5241            0 :             case PGC_INT:
    5242              :                 {
    5243            0 :                     struct config_int *lconf = &conf->_int;
    5244              : 
    5245            0 :                     modified = (lconf->boot_val != *(lconf->variable));
    5246              :                 }
    5247            0 :                 break;
    5248              : 
    5249            0 :             case PGC_REAL:
    5250              :                 {
    5251            0 :                     struct config_real *lconf = &conf->_real;
    5252              : 
    5253            0 :                     modified = (lconf->boot_val != *(lconf->variable));
    5254              :                 }
    5255            0 :                 break;
    5256              : 
    5257            0 :             case PGC_STRING:
    5258              :                 {
    5259            0 :                     struct config_string *lconf = &conf->_string;
    5260              : 
    5261            0 :                     if (lconf->boot_val == NULL &&
    5262            0 :                         *lconf->variable == NULL)
    5263            0 :                         modified = false;
    5264            0 :                     else if (lconf->boot_val == NULL ||
    5265            0 :                              *lconf->variable == NULL)
    5266            0 :                         modified = true;
    5267              :                     else
    5268            0 :                         modified = (strcmp(lconf->boot_val, *(lconf->variable)) != 0);
    5269              :                 }
    5270            0 :                 break;
    5271              : 
    5272            6 :             case PGC_ENUM:
    5273              :                 {
    5274            6 :                     struct config_enum *lconf = &conf->_enum;
    5275              : 
    5276            6 :                     modified = (lconf->boot_val != *(lconf->variable));
    5277              :                 }
    5278            6 :                 break;
    5279              : 
    5280            0 :             default:
    5281            0 :                 elog(ERROR, "unexpected GUC type: %d", conf->vartype);
    5282              :         }
    5283              : 
    5284           12 :         if (!modified)
    5285            0 :             continue;
    5286              : 
    5287              :         /* OK, report it */
    5288           12 :         result[*num] = conf;
    5289           12 :         *num = *num + 1;
    5290              :     }
    5291              : 
    5292            6 :     return result;
    5293              : }
    5294              : 
    5295              : /*
    5296              :  * Return GUC variable value by name; optionally return canonical form of
    5297              :  * name.  If the GUC is unset, then throw an error unless missing_ok is true,
    5298              :  * in which case return NULL.  Return value is palloc'd (but *varname isn't).
    5299              :  */
    5300              : char *
    5301         6732 : GetConfigOptionByName(const char *name, const char **varname, bool missing_ok)
    5302              : {
    5303              :     struct config_generic *record;
    5304              : 
    5305         6732 :     record = find_option(name, false, missing_ok, ERROR);
    5306         6713 :     if (record == NULL)
    5307              :     {
    5308            3 :         if (varname)
    5309            0 :             *varname = NULL;
    5310            3 :         return NULL;
    5311              :     }
    5312              : 
    5313         6710 :     if (!ConfigOptionIsVisible(record))
    5314            1 :         ereport(ERROR,
    5315              :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    5316              :                  errmsg("permission denied to examine \"%s\"", name),
    5317              :                  errdetail("Only roles with privileges of the \"%s\" role may examine this parameter.",
    5318              :                            "pg_read_all_settings")));
    5319              : 
    5320         6709 :     if (varname)
    5321         1479 :         *varname = record->name;
    5322              : 
    5323         6709 :     return ShowGUCOption(record, true);
    5324              : }
    5325              : 
    5326              : /*
    5327              :  * ShowGUCOption: get string value of variable
    5328              :  *
    5329              :  * We express a numeric value in appropriate units if it has units and
    5330              :  * use_units is true; else you just get the raw number.
    5331              :  * The result string is palloc'd.
    5332              :  */
    5333              : char *
    5334      1093027 : ShowGUCOption(const struct config_generic *record, bool use_units)
    5335              : {
    5336              :     char        buffer[256];
    5337              :     const char *val;
    5338              : 
    5339      1093027 :     switch (record->vartype)
    5340              :     {
    5341       304509 :         case PGC_BOOL:
    5342              :             {
    5343       304509 :                 const struct config_bool *conf = &record->_bool;
    5344              : 
    5345       304509 :                 if (conf->show_hook)
    5346        16359 :                     val = conf->show_hook();
    5347              :                 else
    5348       288150 :                     val = *conf->variable ? "on" : "off";
    5349              :             }
    5350       304509 :             break;
    5351              : 
    5352       282122 :         case PGC_INT:
    5353              :             {
    5354       282122 :                 const struct config_int *conf = &record->_int;
    5355              : 
    5356       282122 :                 if (conf->show_hook)
    5357        13042 :                     val = conf->show_hook();
    5358              :                 else
    5359              :                 {
    5360              :                     /*
    5361              :                      * Use int64 arithmetic to avoid overflows in units
    5362              :                      * conversion.
    5363              :                      */
    5364       269080 :                     int64       result = *conf->variable;
    5365              :                     const char *unit;
    5366              : 
    5367       269080 :                     if (use_units && result > 0 && (record->flags & GUC_UNIT))
    5368          390 :                         convert_int_from_base_unit(result,
    5369          390 :                                                    record->flags & GUC_UNIT,
    5370              :                                                    &result, &unit);
    5371              :                     else
    5372       268690 :                         unit = "";
    5373              : 
    5374       269080 :                     snprintf(buffer, sizeof(buffer), INT64_FORMAT "%s",
    5375              :                              result, unit);
    5376       269080 :                     val = buffer;
    5377              :                 }
    5378              :             }
    5379       282122 :             break;
    5380              : 
    5381        47094 :         case PGC_REAL:
    5382              :             {
    5383        47094 :                 const struct config_real *conf = &record->_real;
    5384              : 
    5385        47094 :                 if (conf->show_hook)
    5386            0 :                     val = conf->show_hook();
    5387              :                 else
    5388              :                 {
    5389        47094 :                     double      result = *conf->variable;
    5390              :                     const char *unit;
    5391              : 
    5392        47094 :                     if (use_units && result > 0 && (record->flags & GUC_UNIT))
    5393          134 :                         convert_real_from_base_unit(result,
    5394          134 :                                                     record->flags & GUC_UNIT,
    5395              :                                                     &result, &unit);
    5396              :                     else
    5397        46960 :                         unit = "";
    5398              : 
    5399        47094 :                     snprintf(buffer, sizeof(buffer), "%g%s",
    5400              :                              result, unit);
    5401        47094 :                     val = buffer;
    5402              :                 }
    5403              :             }
    5404        47094 :             break;
    5405              : 
    5406       365634 :         case PGC_STRING:
    5407              :             {
    5408       365634 :                 const struct config_string *conf = &record->_string;
    5409              : 
    5410       365634 :                 if (conf->show_hook)
    5411        33601 :                     val = conf->show_hook();
    5412       332033 :                 else if (*conf->variable && **conf->variable)
    5413       254217 :                     val = *conf->variable;
    5414              :                 else
    5415        77816 :                     val = "";
    5416              :             }
    5417       365634 :             break;
    5418              : 
    5419        93668 :         case PGC_ENUM:
    5420              :             {
    5421        93668 :                 const struct config_enum *conf = &record->_enum;
    5422              : 
    5423        93668 :                 if (conf->show_hook)
    5424         1839 :                     val = conf->show_hook();
    5425              :                 else
    5426        91829 :                     val = config_enum_lookup_by_value(record, *conf->variable);
    5427              :             }
    5428        93668 :             break;
    5429              : 
    5430            0 :         default:
    5431              :             /* just to keep compiler quiet */
    5432            0 :             val = "???";
    5433            0 :             break;
    5434              :     }
    5435              : 
    5436      1093027 :     return pstrdup(val);
    5437              : }
    5438              : 
    5439              : 
    5440              : #ifdef EXEC_BACKEND
    5441              : 
    5442              : /*
    5443              :  *  These routines dump out all non-default GUC options into a binary
    5444              :  *  file that is read by all exec'ed backends.  The format is:
    5445              :  *
    5446              :  *      variable name, string, null terminated
    5447              :  *      variable value, string, null terminated
    5448              :  *      variable sourcefile, string, null terminated (empty if none)
    5449              :  *      variable sourceline, integer
    5450              :  *      variable source, integer
    5451              :  *      variable scontext, integer
    5452              :  *      variable srole, OID
    5453              :  */
    5454              : static void
    5455              : write_one_nondefault_variable(FILE *fp, struct config_generic *gconf)
    5456              : {
    5457              :     Assert(gconf->source != PGC_S_DEFAULT);
    5458              : 
    5459              :     fprintf(fp, "%s", gconf->name);
    5460              :     fputc(0, fp);
    5461              : 
    5462              :     switch (gconf->vartype)
    5463              :     {
    5464              :         case PGC_BOOL:
    5465              :             {
    5466              :                 struct config_bool *conf = &gconf->_bool;
    5467              : 
    5468              :                 if (*conf->variable)
    5469              :                     fprintf(fp, "true");
    5470              :                 else
    5471              :                     fprintf(fp, "false");
    5472              :             }
    5473              :             break;
    5474              : 
    5475              :         case PGC_INT:
    5476              :             {
    5477              :                 struct config_int *conf = &gconf->_int;
    5478              : 
    5479              :                 fprintf(fp, "%d", *conf->variable);
    5480              :             }
    5481              :             break;
    5482              : 
    5483              :         case PGC_REAL:
    5484              :             {
    5485              :                 struct config_real *conf = &gconf->_real;
    5486              : 
    5487              :                 fprintf(fp, "%.17g", *conf->variable);
    5488              :             }
    5489              :             break;
    5490              : 
    5491              :         case PGC_STRING:
    5492              :             {
    5493              :                 struct config_string *conf = &gconf->_string;
    5494              : 
    5495              :                 if (*conf->variable)
    5496              :                     fprintf(fp, "%s", *conf->variable);
    5497              :             }
    5498              :             break;
    5499              : 
    5500              :         case PGC_ENUM:
    5501              :             {
    5502              :                 struct config_enum *conf = &gconf->_enum;
    5503              : 
    5504              :                 fprintf(fp, "%s",
    5505              :                         config_enum_lookup_by_value(gconf, *conf->variable));
    5506              :             }
    5507              :             break;
    5508              :     }
    5509              : 
    5510              :     fputc(0, fp);
    5511              : 
    5512              :     if (gconf->sourcefile)
    5513              :         fprintf(fp, "%s", gconf->sourcefile);
    5514              :     fputc(0, fp);
    5515              : 
    5516              :     fwrite(&gconf->sourceline, 1, sizeof(gconf->sourceline), fp);
    5517              :     fwrite(&gconf->source, 1, sizeof(gconf->source), fp);
    5518              :     fwrite(&gconf->scontext, 1, sizeof(gconf->scontext), fp);
    5519              :     fwrite(&gconf->srole, 1, sizeof(gconf->srole), fp);
    5520              : }
    5521              : 
    5522              : void
    5523              : write_nondefault_variables(GucContext context)
    5524              : {
    5525              :     int         elevel;
    5526              :     FILE       *fp;
    5527              :     dlist_iter  iter;
    5528              : 
    5529              :     Assert(context == PGC_POSTMASTER || context == PGC_SIGHUP);
    5530              : 
    5531              :     elevel = (context == PGC_SIGHUP) ? LOG : ERROR;
    5532              : 
    5533              :     /*
    5534              :      * Open file
    5535              :      */
    5536              :     fp = AllocateFile(CONFIG_EXEC_PARAMS_NEW, "w");
    5537              :     if (!fp)
    5538              :     {
    5539              :         ereport(elevel,
    5540              :                 (errcode_for_file_access(),
    5541              :                  errmsg("could not write to file \"%s\": %m",
    5542              :                         CONFIG_EXEC_PARAMS_NEW)));
    5543              :         return;
    5544              :     }
    5545              : 
    5546              :     /* We need only consider GUCs with source not PGC_S_DEFAULT */
    5547              :     dlist_foreach(iter, &guc_nondef_list)
    5548              :     {
    5549              :         struct config_generic *gconf = dlist_container(struct config_generic,
    5550              :                                                        nondef_link, iter.cur);
    5551              : 
    5552              :         write_one_nondefault_variable(fp, gconf);
    5553              :     }
    5554              : 
    5555              :     if (FreeFile(fp))
    5556              :     {
    5557              :         ereport(elevel,
    5558              :                 (errcode_for_file_access(),
    5559              :                  errmsg("could not write to file \"%s\": %m",
    5560              :                         CONFIG_EXEC_PARAMS_NEW)));
    5561              :         return;
    5562              :     }
    5563              : 
    5564              :     /*
    5565              :      * Put new file in place.  This could delay on Win32, but we don't hold
    5566              :      * any exclusive locks.
    5567              :      */
    5568              :     rename(CONFIG_EXEC_PARAMS_NEW, CONFIG_EXEC_PARAMS);
    5569              : }
    5570              : 
    5571              : 
    5572              : /*
    5573              :  *  Read string, including null byte from file
    5574              :  *
    5575              :  *  Return NULL on EOF and nothing read
    5576              :  */
    5577              : static char *
    5578              : read_string_with_null(FILE *fp)
    5579              : {
    5580              :     int         i = 0,
    5581              :                 ch,
    5582              :                 maxlen = 256;
    5583              :     char       *str = NULL;
    5584              : 
    5585              :     do
    5586              :     {
    5587              :         if ((ch = fgetc(fp)) == EOF)
    5588              :         {
    5589              :             if (i == 0)
    5590              :                 return NULL;
    5591              :             else
    5592              :                 elog(FATAL, "invalid format of exec config params file");
    5593              :         }
    5594              :         if (i == 0)
    5595              :             str = guc_malloc(FATAL, maxlen);
    5596              :         else if (i == maxlen)
    5597              :             str = guc_realloc(FATAL, str, maxlen *= 2);
    5598              :         str[i++] = ch;
    5599              :     } while (ch != 0);
    5600              : 
    5601              :     return str;
    5602              : }
    5603              : 
    5604              : 
    5605              : /*
    5606              :  *  This routine loads a previous postmaster dump of its non-default
    5607              :  *  settings.
    5608              :  */
    5609              : void
    5610              : read_nondefault_variables(void)
    5611              : {
    5612              :     FILE       *fp;
    5613              :     char       *varname,
    5614              :                *varvalue,
    5615              :                *varsourcefile;
    5616              :     int         varsourceline;
    5617              :     GucSource   varsource;
    5618              :     GucContext  varscontext;
    5619              :     Oid         varsrole;
    5620              : 
    5621              :     /*
    5622              :      * Open file
    5623              :      */
    5624              :     fp = AllocateFile(CONFIG_EXEC_PARAMS, "r");
    5625              :     if (!fp)
    5626              :     {
    5627              :         /* File not found is fine */
    5628              :         if (errno != ENOENT)
    5629              :             ereport(FATAL,
    5630              :                     (errcode_for_file_access(),
    5631              :                      errmsg("could not read from file \"%s\": %m",
    5632              :                             CONFIG_EXEC_PARAMS)));
    5633              :         return;
    5634              :     }
    5635              : 
    5636              :     for (;;)
    5637              :     {
    5638              :         if ((varname = read_string_with_null(fp)) == NULL)
    5639              :             break;
    5640              : 
    5641              :         if (find_option(varname, true, false, FATAL) == NULL)
    5642              :             elog(FATAL, "failed to locate variable \"%s\" in exec config params file", varname);
    5643              : 
    5644              :         if ((varvalue = read_string_with_null(fp)) == NULL)
    5645              :             elog(FATAL, "invalid format of exec config params file");
    5646              :         if ((varsourcefile = read_string_with_null(fp)) == NULL)
    5647              :             elog(FATAL, "invalid format of exec config params file");
    5648              :         if (fread(&varsourceline, 1, sizeof(varsourceline), fp) != sizeof(varsourceline))
    5649              :             elog(FATAL, "invalid format of exec config params file");
    5650              :         if (fread(&varsource, 1, sizeof(varsource), fp) != sizeof(varsource))
    5651              :             elog(FATAL, "invalid format of exec config params file");
    5652              :         if (fread(&varscontext, 1, sizeof(varscontext), fp) != sizeof(varscontext))
    5653              :             elog(FATAL, "invalid format of exec config params file");
    5654              :         if (fread(&varsrole, 1, sizeof(varsrole), fp) != sizeof(varsrole))
    5655              :             elog(FATAL, "invalid format of exec config params file");
    5656              : 
    5657              :         (void) set_config_option_ext(varname, varvalue,
    5658              :                                      varscontext, varsource, varsrole,
    5659              :                                      GUC_ACTION_SET, true, 0, true);
    5660              :         if (varsourcefile[0])
    5661              :             set_config_sourcefile(varname, varsourcefile, varsourceline);
    5662              : 
    5663              :         guc_free(varname);
    5664              :         guc_free(varvalue);
    5665              :         guc_free(varsourcefile);
    5666              :     }
    5667              : 
    5668              :     FreeFile(fp);
    5669              : }
    5670              : #endif                          /* EXEC_BACKEND */
    5671              : 
    5672              : /*
    5673              :  * can_skip_gucvar:
    5674              :  * Decide whether SerializeGUCState can skip sending this GUC variable,
    5675              :  * or whether RestoreGUCState can skip resetting this GUC to default.
    5676              :  *
    5677              :  * It is somewhat magical and fragile that the same test works for both cases.
    5678              :  * Realize in particular that we are very likely selecting different sets of
    5679              :  * GUCs on the leader and worker sides!  Be sure you've understood the
    5680              :  * comments here and in RestoreGUCState thoroughly before changing this.
    5681              :  */
    5682              : static bool
    5683       140888 : can_skip_gucvar(struct config_generic *gconf)
    5684              : {
    5685              :     /*
    5686              :      * We can skip GUCs that are guaranteed to have the same values in leaders
    5687              :      * and workers.  (Note it is critical that the leader and worker have the
    5688              :      * same idea of which GUCs fall into this category.  It's okay to consider
    5689              :      * context and name for this purpose, since those are unchanging
    5690              :      * properties of a GUC.)
    5691              :      *
    5692              :      * PGC_POSTMASTER variables always have the same value in every child of a
    5693              :      * particular postmaster, so the worker will certainly have the right
    5694              :      * value already.  Likewise, PGC_INTERNAL variables are set by special
    5695              :      * mechanisms (if indeed they aren't compile-time constants).  So we may
    5696              :      * always skip these.
    5697              :      *
    5698              :      * For all other GUCs, we skip if the GUC has its compiled-in default
    5699              :      * value (i.e., source == PGC_S_DEFAULT).  On the leader side, this means
    5700              :      * we don't send GUCs that have their default values, which typically
    5701              :      * saves lots of work.  On the worker side, this means we don't need to
    5702              :      * reset the GUC to default because it already has that value.  See
    5703              :      * comments in RestoreGUCState for more info.
    5704              :      */
    5705       231576 :     return gconf->context == PGC_POSTMASTER ||
    5706       211736 :         gconf->context == PGC_INTERNAL ||
    5707        70848 :         gconf->source == PGC_S_DEFAULT;
    5708              : }
    5709              : 
    5710              : /*
    5711              :  * estimate_variable_size:
    5712              :  *      Compute space needed for dumping the given GUC variable.
    5713              :  *
    5714              :  * It's OK to overestimate, but not to underestimate.
    5715              :  */
    5716              : static Size
    5717        31179 : estimate_variable_size(struct config_generic *gconf)
    5718              : {
    5719              :     Size        size;
    5720        31179 :     Size        valsize = 0;
    5721              : 
    5722              :     /* Skippable GUCs consume zero space. */
    5723        31179 :     if (can_skip_gucvar(gconf))
    5724        14049 :         return 0;
    5725              : 
    5726              :     /* Name, plus trailing zero byte. */
    5727        17130 :     size = strlen(gconf->name) + 1;
    5728              : 
    5729              :     /* Get the maximum display length of the GUC value. */
    5730        17130 :     switch (gconf->vartype)
    5731              :     {
    5732         3427 :         case PGC_BOOL:
    5733              :             {
    5734         3427 :                 valsize = 5;    /* max(strlen('true'), strlen('false')) */
    5735              :             }
    5736         3427 :             break;
    5737              : 
    5738         3487 :         case PGC_INT:
    5739              :             {
    5740         3487 :                 struct config_int *conf = &gconf->_int;
    5741              : 
    5742              :                 /*
    5743              :                  * Instead of getting the exact display length, use max
    5744              :                  * length.  Also reduce the max length for typical ranges of
    5745              :                  * small values.  Maximum value is 2147483647, i.e. 10 chars.
    5746              :                  * Include one byte for sign.
    5747              :                  */
    5748         3487 :                 if (abs(*conf->variable) < 1000)
    5749         2776 :                     valsize = 3 + 1;
    5750              :                 else
    5751          711 :                     valsize = 10 + 1;
    5752              :             }
    5753         3487 :             break;
    5754              : 
    5755          880 :         case PGC_REAL:
    5756              :             {
    5757              :                 /*
    5758              :                  * We are going to print it with %e with REALTYPE_PRECISION
    5759              :                  * fractional digits.  Account for sign, leading digit,
    5760              :                  * decimal point, and exponent with up to 3 digits.  E.g.
    5761              :                  * -3.99329042340000021e+110
    5762              :                  */
    5763          880 :                 valsize = 1 + 1 + 1 + REALTYPE_PRECISION + 5;
    5764              :             }
    5765          880 :             break;
    5766              : 
    5767         7261 :         case PGC_STRING:
    5768              :             {
    5769         7261 :                 struct config_string *conf = &gconf->_string;
    5770              : 
    5771              :                 /*
    5772              :                  * If the value is NULL, we transmit it as an empty string.
    5773              :                  * Although this is not physically the same value, GUC
    5774              :                  * generally treats a NULL the same as empty string.
    5775              :                  */
    5776         7261 :                 if (*conf->variable)
    5777         7261 :                     valsize = strlen(*conf->variable);
    5778              :                 else
    5779            0 :                     valsize = 0;
    5780              :             }
    5781         7261 :             break;
    5782              : 
    5783         2075 :         case PGC_ENUM:
    5784              :             {
    5785         2075 :                 struct config_enum *conf = &gconf->_enum;
    5786              : 
    5787         2075 :                 valsize = strlen(config_enum_lookup_by_value(gconf, *conf->variable));
    5788              :             }
    5789         2075 :             break;
    5790              :     }
    5791              : 
    5792              :     /* Allow space for terminating zero-byte for value */
    5793        17130 :     size = add_size(size, valsize + 1);
    5794              : 
    5795        17130 :     if (gconf->sourcefile)
    5796         8612 :         size = add_size(size, strlen(gconf->sourcefile));
    5797              : 
    5798              :     /* Allow space for terminating zero-byte for sourcefile */
    5799        17130 :     size = add_size(size, 1);
    5800              : 
    5801              :     /* Include line whenever file is nonempty. */
    5802        17130 :     if (gconf->sourcefile && gconf->sourcefile[0])
    5803         8612 :         size = add_size(size, sizeof(gconf->sourceline));
    5804              : 
    5805        17130 :     size = add_size(size, sizeof(gconf->source));
    5806        17130 :     size = add_size(size, sizeof(gconf->scontext));
    5807        17130 :     size = add_size(size, sizeof(gconf->srole));
    5808              : 
    5809        17130 :     return size;
    5810              : }
    5811              : 
    5812              : /*
    5813              :  * EstimateGUCStateSpace:
    5814              :  * Returns the size needed to store the GUC state for the current process
    5815              :  */
    5816              : Size
    5817          498 : EstimateGUCStateSpace(void)
    5818              : {
    5819              :     Size        size;
    5820              :     dlist_iter  iter;
    5821              : 
    5822              :     /* Add space reqd for saving the data size of the guc state */
    5823          498 :     size = sizeof(Size);
    5824              : 
    5825              :     /*
    5826              :      * Add up the space needed for each GUC variable.
    5827              :      *
    5828              :      * We need only process non-default GUCs.
    5829              :      */
    5830        31677 :     dlist_foreach(iter, &guc_nondef_list)
    5831              :     {
    5832        31179 :         struct config_generic *gconf = dlist_container(struct config_generic,
    5833              :                                                        nondef_link, iter.cur);
    5834              : 
    5835        31179 :         size = add_size(size, estimate_variable_size(gconf));
    5836              :     }
    5837              : 
    5838          498 :     return size;
    5839              : }
    5840              : 
    5841              : /*
    5842              :  * do_serialize:
    5843              :  * Copies the formatted string into the destination.  Moves ahead the
    5844              :  * destination pointer, and decrements the maxbytes by that many bytes. If
    5845              :  * maxbytes is not sufficient to copy the string, error out.
    5846              :  */
    5847              : static void
    5848        51390 : do_serialize(char **destptr, Size *maxbytes, const char *fmt,...)
    5849              : {
    5850              :     va_list     vargs;
    5851              :     int         n;
    5852              : 
    5853        51390 :     if (*maxbytes <= 0)
    5854            0 :         elog(ERROR, "not enough space to serialize GUC state");
    5855              : 
    5856        51390 :     va_start(vargs, fmt);
    5857        51390 :     n = vsnprintf(*destptr, *maxbytes, fmt, vargs);
    5858        51390 :     va_end(vargs);
    5859              : 
    5860        51390 :     if (n < 0)
    5861              :     {
    5862              :         /* Shouldn't happen. Better show errno description. */
    5863            0 :         elog(ERROR, "vsnprintf failed: %m with format string \"%s\"", fmt);
    5864              :     }
    5865        51390 :     if (n >= *maxbytes)
    5866              :     {
    5867              :         /* This shouldn't happen either, really. */
    5868            0 :         elog(ERROR, "not enough space to serialize GUC state");
    5869              :     }
    5870              : 
    5871              :     /* Shift the destptr ahead of the null terminator */
    5872        51390 :     *destptr += n + 1;
    5873        51390 :     *maxbytes -= n + 1;
    5874        51390 : }
    5875              : 
    5876              : /* Binary copy version of do_serialize() */
    5877              : static void
    5878        60002 : do_serialize_binary(char **destptr, Size *maxbytes, void *val, Size valsize)
    5879              : {
    5880        60002 :     if (valsize > *maxbytes)
    5881            0 :         elog(ERROR, "not enough space to serialize GUC state");
    5882              : 
    5883        60002 :     memcpy(*destptr, val, valsize);
    5884        60002 :     *destptr += valsize;
    5885        60002 :     *maxbytes -= valsize;
    5886        60002 : }
    5887              : 
    5888              : /*
    5889              :  * serialize_variable:
    5890              :  * Dumps name, value and other information of a GUC variable into destptr.
    5891              :  */
    5892              : static void
    5893        31179 : serialize_variable(char **destptr, Size *maxbytes,
    5894              :                    struct config_generic *gconf)
    5895              : {
    5896              :     /* Ignore skippable GUCs. */
    5897        31179 :     if (can_skip_gucvar(gconf))
    5898        14049 :         return;
    5899              : 
    5900        17130 :     do_serialize(destptr, maxbytes, "%s", gconf->name);
    5901              : 
    5902        17130 :     switch (gconf->vartype)
    5903              :     {
    5904         3427 :         case PGC_BOOL:
    5905              :             {
    5906         3427 :                 struct config_bool *conf = &gconf->_bool;
    5907              : 
    5908         3427 :                 do_serialize(destptr, maxbytes,
    5909         3427 :                              (*conf->variable ? "true" : "false"));
    5910              :             }
    5911         3427 :             break;
    5912              : 
    5913         3487 :         case PGC_INT:
    5914              :             {
    5915         3487 :                 struct config_int *conf = &gconf->_int;
    5916              : 
    5917         3487 :                 do_serialize(destptr, maxbytes, "%d", *conf->variable);
    5918              :             }
    5919         3487 :             break;
    5920              : 
    5921          880 :         case PGC_REAL:
    5922              :             {
    5923          880 :                 struct config_real *conf = &gconf->_real;
    5924              : 
    5925          880 :                 do_serialize(destptr, maxbytes, "%.*e",
    5926          880 :                              REALTYPE_PRECISION, *conf->variable);
    5927              :             }
    5928          880 :             break;
    5929              : 
    5930         7261 :         case PGC_STRING:
    5931              :             {
    5932         7261 :                 struct config_string *conf = &gconf->_string;
    5933              : 
    5934              :                 /* NULL becomes empty string, see estimate_variable_size() */
    5935         7261 :                 do_serialize(destptr, maxbytes, "%s",
    5936         7261 :                              *conf->variable ? *conf->variable : "");
    5937              :             }
    5938         7261 :             break;
    5939              : 
    5940         2075 :         case PGC_ENUM:
    5941              :             {
    5942         2075 :                 struct config_enum *conf = &gconf->_enum;
    5943              : 
    5944         2075 :                 do_serialize(destptr, maxbytes, "%s",
    5945         2075 :                              config_enum_lookup_by_value(gconf, *conf->variable));
    5946              :             }
    5947         2075 :             break;
    5948              :     }
    5949              : 
    5950        17130 :     do_serialize(destptr, maxbytes, "%s",
    5951        17130 :                  (gconf->sourcefile ? gconf->sourcefile : ""));
    5952              : 
    5953        17130 :     if (gconf->sourcefile && gconf->sourcefile[0])
    5954         8612 :         do_serialize_binary(destptr, maxbytes, &gconf->sourceline,
    5955              :                             sizeof(gconf->sourceline));
    5956              : 
    5957        17130 :     do_serialize_binary(destptr, maxbytes, &gconf->source,
    5958              :                         sizeof(gconf->source));
    5959        17130 :     do_serialize_binary(destptr, maxbytes, &gconf->scontext,
    5960              :                         sizeof(gconf->scontext));
    5961        17130 :     do_serialize_binary(destptr, maxbytes, &gconf->srole,
    5962              :                         sizeof(gconf->srole));
    5963              : }
    5964              : 
    5965              : /*
    5966              :  * SerializeGUCState:
    5967              :  * Dumps the complete GUC state onto the memory location at start_address.
    5968              :  */
    5969              : void
    5970          498 : SerializeGUCState(Size maxsize, char *start_address)
    5971              : {
    5972              :     char       *curptr;
    5973              :     Size        actual_size;
    5974              :     Size        bytes_left;
    5975              :     dlist_iter  iter;
    5976              : 
    5977              :     /* Reserve space for saving the actual size of the guc state */
    5978              :     Assert(maxsize > sizeof(actual_size));
    5979          498 :     curptr = start_address + sizeof(actual_size);
    5980          498 :     bytes_left = maxsize - sizeof(actual_size);
    5981              : 
    5982              :     /* We need only consider GUCs with source not PGC_S_DEFAULT */
    5983        31677 :     dlist_foreach(iter, &guc_nondef_list)
    5984              :     {
    5985        31179 :         struct config_generic *gconf = dlist_container(struct config_generic,
    5986              :                                                        nondef_link, iter.cur);
    5987              : 
    5988        31179 :         serialize_variable(&curptr, &bytes_left, gconf);
    5989              :     }
    5990              : 
    5991              :     /* Store actual size without assuming alignment of start_address. */
    5992          498 :     actual_size = maxsize - bytes_left - sizeof(actual_size);
    5993          498 :     memcpy(start_address, &actual_size, sizeof(actual_size));
    5994          498 : }
    5995              : 
    5996              : /*
    5997              :  * read_gucstate:
    5998              :  * Actually it does not read anything, just returns the srcptr. But it does
    5999              :  * move the srcptr past the terminating zero byte, so that the caller is ready
    6000              :  * to read the next string.
    6001              :  */
    6002              : static char *
    6003       159549 : read_gucstate(char **srcptr, char *srcend)
    6004              : {
    6005       159549 :     char       *retptr = *srcptr;
    6006              :     char       *ptr;
    6007              : 
    6008       159549 :     if (*srcptr >= srcend)
    6009            0 :         elog(ERROR, "incomplete GUC state");
    6010              : 
    6011              :     /* The string variables are all null terminated */
    6012      3953883 :     for (ptr = *srcptr; ptr < srcend && *ptr != '\0'; ptr++)
    6013              :         ;
    6014              : 
    6015       159549 :     if (ptr >= srcend)
    6016            0 :         elog(ERROR, "could not find null terminator in GUC state");
    6017              : 
    6018              :     /* Set the new position to the byte following the terminating NUL */
    6019       159549 :     *srcptr = ptr + 1;
    6020              : 
    6021       159549 :     return retptr;
    6022              : }
    6023              : 
    6024              : /* Binary read version of read_gucstate(). Copies into dest */
    6025              : static void
    6026       185240 : read_gucstate_binary(char **srcptr, char *srcend, void *dest, Size size)
    6027              : {
    6028       185240 :     if (*srcptr + size > srcend)
    6029            0 :         elog(ERROR, "incomplete GUC state");
    6030              : 
    6031       185240 :     memcpy(dest, *srcptr, size);
    6032       185240 :     *srcptr += size;
    6033       185240 : }
    6034              : 
    6035              : /*
    6036              :  * Callback used to add a context message when reporting errors that occur
    6037              :  * while trying to restore GUCs in parallel workers.
    6038              :  */
    6039              : static void
    6040            0 : guc_restore_error_context_callback(void *arg)
    6041              : {
    6042            0 :     char      **error_context_name_and_value = (char **) arg;
    6043              : 
    6044            0 :     if (error_context_name_and_value)
    6045            0 :         errcontext("while setting parameter \"%s\" to \"%s\"",
    6046              :                    error_context_name_and_value[0],
    6047            0 :                    error_context_name_and_value[1]);
    6048            0 : }
    6049              : 
    6050              : /*
    6051              :  * RestoreGUCState:
    6052              :  * Reads the GUC state at the specified address and sets this process's
    6053              :  * GUCs to match.
    6054              :  *
    6055              :  * Note that this provides the worker with only a very shallow view of the
    6056              :  * leader's GUC state: we'll know about the currently active values, but not
    6057              :  * about stacked or reset values.  That's fine since the worker is just
    6058              :  * executing one part of a query, within which the active values won't change
    6059              :  * and the stacked values are invisible.
    6060              :  */
    6061              : void
    6062         1484 : RestoreGUCState(void *gucstate)
    6063              : {
    6064              :     char       *varname,
    6065              :                *varvalue,
    6066              :                *varsourcefile;
    6067              :     int         varsourceline;
    6068              :     GucSource   varsource;
    6069              :     GucContext  varscontext;
    6070              :     Oid         varsrole;
    6071         1484 :     char       *srcptr = (char *) gucstate;
    6072              :     char       *srcend;
    6073              :     Size        len;
    6074              :     dlist_mutable_iter iter;
    6075              :     ErrorContextCallback error_context_callback;
    6076              : 
    6077              :     /*
    6078              :      * First, ensure that all potentially-shippable GUCs are reset to their
    6079              :      * default values.  We must not touch those GUCs that the leader will
    6080              :      * never ship, while there is no need to touch those that are shippable
    6081              :      * but already have their default values.  Thus, this ends up being the
    6082              :      * same test that SerializeGUCState uses, even though the sets of
    6083              :      * variables involved may well be different since the leader's set of
    6084              :      * variables-not-at-default-values can differ from the set that are
    6085              :      * not-default in this freshly started worker.
    6086              :      *
    6087              :      * Once we have set all the potentially-shippable GUCs to default values,
    6088              :      * restoring the GUCs that the leader sent (because they had non-default
    6089              :      * values over there) leads us to exactly the set of GUC values that the
    6090              :      * leader has.  This is true even though the worker may have initially
    6091              :      * absorbed postgresql.conf settings that the leader hasn't yet seen, or
    6092              :      * ALTER USER/DATABASE SET settings that were established after the leader
    6093              :      * started.
    6094              :      *
    6095              :      * Note that ensuring all the potential target GUCs are at PGC_S_DEFAULT
    6096              :      * also ensures that set_config_option won't refuse to set them because of
    6097              :      * source-priority comparisons.
    6098              :      */
    6099        80014 :     dlist_foreach_modify(iter, &guc_nondef_list)
    6100              :     {
    6101        78530 :         struct config_generic *gconf = dlist_container(struct config_generic,
    6102              :                                                        nondef_link, iter.cur);
    6103              : 
    6104              :         /* Do nothing if non-shippable or if already at PGC_S_DEFAULT. */
    6105        78530 :         if (can_skip_gucvar(gconf))
    6106        41942 :             continue;
    6107              : 
    6108              :         /*
    6109              :          * We can use InitializeOneGUCOption to reset the GUC to default, but
    6110              :          * first we must free any existing subsidiary data to avoid leaking
    6111              :          * memory.  The stack must be empty, but we have to clean up all other
    6112              :          * fields.  Beware that there might be duplicate value or "extra"
    6113              :          * pointers.  We also have to be sure to take it out of any lists it's
    6114              :          * in.
    6115              :          */
    6116              :         Assert(gconf->stack == NULL);
    6117        36588 :         guc_free(gconf->extra);
    6118        36588 :         guc_free(gconf->last_reported);
    6119        36588 :         guc_free(gconf->sourcefile);
    6120        36588 :         switch (gconf->vartype)
    6121              :         {
    6122        19774 :             case PGC_BOOL:
    6123              :             case PGC_INT:
    6124              :             case PGC_REAL:
    6125              :             case PGC_ENUM:
    6126              :                 /* no need to do anything */
    6127        19774 :                 break;
    6128        16814 :             case PGC_STRING:
    6129              :                 {
    6130        16814 :                     struct config_string *conf = &gconf->_string;
    6131              : 
    6132        16814 :                     guc_free(*conf->variable);
    6133        16814 :                     if (conf->reset_val && conf->reset_val != *conf->variable)
    6134            0 :                         guc_free(conf->reset_val);
    6135        16814 :                     break;
    6136              :                 }
    6137              :         }
    6138        36588 :         if (gconf->reset_extra && gconf->reset_extra != gconf->extra)
    6139            0 :             guc_free(gconf->reset_extra);
    6140              :         /* Remove it from any lists it's in. */
    6141        36588 :         RemoveGUCFromLists(gconf);
    6142              :         /* Now we can reset the struct to PGS_S_DEFAULT state. */
    6143        36588 :         InitializeOneGUCOption(gconf);
    6144              :     }
    6145              : 
    6146              :     /* First item is the length of the subsequent data */
    6147         1484 :     memcpy(&len, gucstate, sizeof(len));
    6148              : 
    6149         1484 :     srcptr += sizeof(len);
    6150         1484 :     srcend = srcptr + len;
    6151              : 
    6152              :     /* If the GUC value check fails, we want errors to show useful context. */
    6153         1484 :     error_context_callback.callback = guc_restore_error_context_callback;
    6154         1484 :     error_context_callback.previous = error_context_stack;
    6155         1484 :     error_context_callback.arg = NULL;
    6156         1484 :     error_context_stack = &error_context_callback;
    6157              : 
    6158              :     /* Restore all the listed GUCs. */
    6159        54667 :     while (srcptr < srcend)
    6160              :     {
    6161              :         int         result;
    6162              :         char       *error_context_name_and_value[2];
    6163              : 
    6164        53183 :         varname = read_gucstate(&srcptr, srcend);
    6165        53183 :         varvalue = read_gucstate(&srcptr, srcend);
    6166        53183 :         varsourcefile = read_gucstate(&srcptr, srcend);
    6167        53183 :         if (varsourcefile[0])
    6168        25691 :             read_gucstate_binary(&srcptr, srcend,
    6169              :                                  &varsourceline, sizeof(varsourceline));
    6170              :         else
    6171        27492 :             varsourceline = 0;
    6172        53183 :         read_gucstate_binary(&srcptr, srcend,
    6173              :                              &varsource, sizeof(varsource));
    6174        53183 :         read_gucstate_binary(&srcptr, srcend,
    6175              :                              &varscontext, sizeof(varscontext));
    6176        53183 :         read_gucstate_binary(&srcptr, srcend,
    6177              :                              &varsrole, sizeof(varsrole));
    6178              : 
    6179        53183 :         error_context_name_and_value[0] = varname;
    6180        53183 :         error_context_name_and_value[1] = varvalue;
    6181        53183 :         error_context_callback.arg = &error_context_name_and_value[0];
    6182        53183 :         result = set_config_option_ext(varname, varvalue,
    6183              :                                        varscontext, varsource, varsrole,
    6184              :                                        GUC_ACTION_SET, true, ERROR, true);
    6185        53183 :         if (result <= 0)
    6186            0 :             ereport(ERROR,
    6187              :                     (errcode(ERRCODE_INTERNAL_ERROR),
    6188              :                      errmsg("parameter \"%s\" could not be set", varname)));
    6189        53183 :         if (varsourcefile[0])
    6190        25691 :             set_config_sourcefile(varname, varsourcefile, varsourceline);
    6191        53183 :         error_context_callback.arg = NULL;
    6192              :     }
    6193              : 
    6194         1484 :     error_context_stack = error_context_callback.previous;
    6195         1484 : }
    6196              : 
    6197              : /*
    6198              :  * A little "long argument" simulation, although not quite GNU
    6199              :  * compliant. Takes a string of the form "some-option=some value" and
    6200              :  * returns name = "some_option" and value = "some value" in palloc'ed
    6201              :  * storage. Note that '-' is converted to '_' in the option name. If
    6202              :  * there is no '=' in the input string then value will be NULL.
    6203              :  */
    6204              : void
    6205        29023 : ParseLongOption(const char *string, char **name, char **value)
    6206              : {
    6207              :     size_t      equal_pos;
    6208              : 
    6209              :     Assert(string);
    6210              :     Assert(name);
    6211              :     Assert(value);
    6212              : 
    6213        29023 :     equal_pos = strcspn(string, "=");
    6214              : 
    6215        29023 :     if (string[equal_pos] == '=')
    6216              :     {
    6217        29022 :         *name = palloc(equal_pos + 1);
    6218        29022 :         strlcpy(*name, string, equal_pos + 1);
    6219              : 
    6220        29022 :         *value = pstrdup(&string[equal_pos + 1]);
    6221              :     }
    6222              :     else
    6223              :     {
    6224              :         /* no equal sign in string */
    6225            1 :         *name = pstrdup(string);
    6226            1 :         *value = NULL;
    6227              :     }
    6228              : 
    6229       407623 :     for (char *cp = *name; *cp; cp++)
    6230       378600 :         if (*cp == '-')
    6231          899 :             *cp = '_';
    6232        29023 : }
    6233              : 
    6234              : 
    6235              : /*
    6236              :  * Transform array of GUC settings into lists of names and values. The lists
    6237              :  * are faster to process in cases where the settings must be applied
    6238              :  * repeatedly (e.g. for each function invocation).
    6239              :  */
    6240              : void
    6241         3694 : TransformGUCArray(ArrayType *array, List **names, List **values)
    6242              : {
    6243              :     Assert(array != NULL);
    6244              :     Assert(ARR_ELEMTYPE(array) == TEXTOID);
    6245              :     Assert(ARR_NDIM(array) == 1);
    6246              :     Assert(ARR_LBOUND(array)[0] == 1);
    6247              : 
    6248         3694 :     *names = NIL;
    6249         3694 :     *values = NIL;
    6250        25316 :     for (int i = 1; i <= ARR_DIMS(array)[0]; i++)
    6251              :     {
    6252              :         Datum       d;
    6253              :         bool        isnull;
    6254              :         char       *s;
    6255              :         char       *name;
    6256              :         char       *value;
    6257              : 
    6258        21622 :         d = array_ref(array, 1, &i,
    6259              :                       -1 /* varlenarray */ ,
    6260              :                       -1 /* TEXT's typlen */ ,
    6261              :                       false /* TEXT's typbyval */ ,
    6262              :                       TYPALIGN_INT /* TEXT's typalign */ ,
    6263              :                       &isnull);
    6264              : 
    6265        21622 :         if (isnull)
    6266            0 :             continue;
    6267              : 
    6268        21622 :         s = TextDatumGetCString(d);
    6269              : 
    6270        21622 :         ParseLongOption(s, &name, &value);
    6271        21622 :         if (!value)
    6272              :         {
    6273            0 :             ereport(WARNING,
    6274              :                     (errcode(ERRCODE_SYNTAX_ERROR),
    6275              :                      errmsg("could not parse setting for parameter \"%s\"",
    6276              :                             name)));
    6277            0 :             pfree(name);
    6278            0 :             continue;
    6279              :         }
    6280              : 
    6281        21622 :         *names = lappend(*names, name);
    6282        21622 :         *values = lappend(*values, value);
    6283              : 
    6284        21622 :         pfree(s);
    6285              :     }
    6286         3694 : }
    6287              : 
    6288              : 
    6289              : /*
    6290              :  * Handle options fetched from pg_db_role_setting.setconfig,
    6291              :  * pg_proc.proconfig, etc.  Caller must specify proper context/source/action.
    6292              :  *
    6293              :  * The array parameter must be an array of TEXT (it must not be NULL).
    6294              :  */
    6295              : void
    6296         3628 : ProcessGUCArray(ArrayType *array,
    6297              :                 GucContext context, GucSource source, GucAction action)
    6298              : {
    6299              :     List       *gucNames;
    6300              :     List       *gucValues;
    6301              :     ListCell   *lc1;
    6302              :     ListCell   *lc2;
    6303              : 
    6304         3628 :     TransformGUCArray(array, &gucNames, &gucValues);
    6305        25178 :     forboth(lc1, gucNames, lc2, gucValues)
    6306              :     {
    6307        21556 :         char       *name = lfirst(lc1);
    6308        21556 :         char       *value = lfirst(lc2);
    6309              : 
    6310        21556 :         (void) set_config_option(name, value,
    6311              :                                  context, source,
    6312              :                                  action, true, 0, false);
    6313              : 
    6314        21550 :         pfree(name);
    6315        21550 :         pfree(value);
    6316              :     }
    6317              : 
    6318         3622 :     list_free(gucNames);
    6319         3622 :     list_free(gucValues);
    6320         3622 : }
    6321              : 
    6322              : 
    6323              : /*
    6324              :  * Add an entry to an option array.  The array parameter may be NULL
    6325              :  * to indicate the current table entry is NULL.
    6326              :  */
    6327              : ArrayType *
    6328          731 : GUCArrayAdd(ArrayType *array, const char *name, const char *value)
    6329              : {
    6330              :     struct config_generic *record;
    6331              :     Datum       datum;
    6332              :     char       *newval;
    6333              :     ArrayType  *a;
    6334              : 
    6335              :     Assert(name);
    6336              :     Assert(value);
    6337              : 
    6338              :     /* test if the option is valid and we're allowed to set it */
    6339          731 :     (void) validate_option_array_item(name, value, false);
    6340              : 
    6341              :     /* normalize name (converts obsolete GUC names to modern spellings) */
    6342          729 :     record = find_option(name, false, true, WARNING);
    6343          729 :     if (record)
    6344          729 :         name = record->name;
    6345              : 
    6346              :     /* build new item for array */
    6347          729 :     newval = psprintf("%s=%s", name, value);
    6348          729 :     datum = CStringGetTextDatum(newval);
    6349              : 
    6350          729 :     if (array)
    6351              :     {
    6352              :         int         index;
    6353              :         bool        isnull;
    6354              : 
    6355              :         Assert(ARR_ELEMTYPE(array) == TEXTOID);
    6356              :         Assert(ARR_NDIM(array) == 1);
    6357              :         Assert(ARR_LBOUND(array)[0] == 1);
    6358              : 
    6359          557 :         index = ARR_DIMS(array)[0] + 1; /* add after end */
    6360              : 
    6361         2212 :         for (int i = 1; i <= ARR_DIMS(array)[0]; i++)
    6362              :         {
    6363              :             Datum       d;
    6364              :             char       *current;
    6365              : 
    6366         1662 :             d = array_ref(array, 1, &i,
    6367              :                           -1 /* varlenarray */ ,
    6368              :                           -1 /* TEXT's typlen */ ,
    6369              :                           false /* TEXT's typbyval */ ,
    6370              :                           TYPALIGN_INT /* TEXT's typalign */ ,
    6371              :                           &isnull);
    6372         1662 :             if (isnull)
    6373            0 :                 continue;
    6374         1662 :             current = TextDatumGetCString(d);
    6375              : 
    6376              :             /* check for match up through and including '=' */
    6377         1662 :             if (strncmp(current, newval, strlen(name) + 1) == 0)
    6378              :             {
    6379            7 :                 index = i;
    6380            7 :                 break;
    6381              :             }
    6382              :         }
    6383              : 
    6384          557 :         a = array_set(array, 1, &index,
    6385              :                       datum,
    6386              :                       false,
    6387              :                       -1 /* varlena array */ ,
    6388              :                       -1 /* TEXT's typlen */ ,
    6389              :                       false /* TEXT's typbyval */ ,
    6390              :                       TYPALIGN_INT /* TEXT's typalign */ );
    6391              :     }
    6392              :     else
    6393          172 :         a = construct_array_builtin(&datum, 1, TEXTOID);
    6394              : 
    6395          729 :     return a;
    6396              : }
    6397              : 
    6398              : 
    6399              : /*
    6400              :  * Delete an entry from an option array.  The array parameter may be NULL
    6401              :  * to indicate the current table entry is NULL.  Also, if the return value
    6402              :  * is NULL then a null should be stored.
    6403              :  */
    6404              : ArrayType *
    6405           20 : GUCArrayDelete(ArrayType *array, const char *name)
    6406              : {
    6407              :     struct config_generic *record;
    6408              :     ArrayType  *newarray;
    6409              :     int         index;
    6410              : 
    6411              :     Assert(name);
    6412              : 
    6413              :     /* test if the option is valid and we're allowed to set it */
    6414           20 :     (void) validate_option_array_item(name, NULL, false);
    6415              : 
    6416              :     /* normalize name (converts obsolete GUC names to modern spellings) */
    6417           18 :     record = find_option(name, false, true, WARNING);
    6418           18 :     if (record)
    6419           15 :         name = record->name;
    6420              : 
    6421              :     /* if array is currently null, then surely nothing to delete */
    6422           18 :     if (!array)
    6423            2 :         return NULL;
    6424              : 
    6425           16 :     newarray = NULL;
    6426           16 :     index = 1;
    6427              : 
    6428           51 :     for (int i = 1; i <= ARR_DIMS(array)[0]; i++)
    6429              :     {
    6430              :         Datum       d;
    6431              :         char       *val;
    6432              :         bool        isnull;
    6433              : 
    6434           35 :         d = array_ref(array, 1, &i,
    6435              :                       -1 /* varlenarray */ ,
    6436              :                       -1 /* TEXT's typlen */ ,
    6437              :                       false /* TEXT's typbyval */ ,
    6438              :                       TYPALIGN_INT /* TEXT's typalign */ ,
    6439              :                       &isnull);
    6440           35 :         if (isnull)
    6441           16 :             continue;
    6442           35 :         val = TextDatumGetCString(d);
    6443              : 
    6444              :         /* ignore entry if it's what we want to delete */
    6445           35 :         if (strncmp(val, name, strlen(name)) == 0
    6446           16 :             && val[strlen(name)] == '=')
    6447           16 :             continue;
    6448              : 
    6449              :         /* else add it to the output array */
    6450           19 :         if (newarray)
    6451           15 :             newarray = array_set(newarray, 1, &index,
    6452              :                                  d,
    6453              :                                  false,
    6454              :                                  -1 /* varlenarray */ ,
    6455              :                                  -1 /* TEXT's typlen */ ,
    6456              :                                  false /* TEXT's typbyval */ ,
    6457              :                                  TYPALIGN_INT /* TEXT's typalign */ );
    6458              :         else
    6459            4 :             newarray = construct_array_builtin(&d, 1, TEXTOID);
    6460              : 
    6461           19 :         index++;
    6462              :     }
    6463              : 
    6464           16 :     return newarray;
    6465              : }
    6466              : 
    6467              : 
    6468              : /*
    6469              :  * Given a GUC array, delete all settings from it that our permission
    6470              :  * level allows: if superuser, delete them all; if regular user, only
    6471              :  * those that are PGC_USERSET or we have permission to set
    6472              :  */
    6473              : ArrayType *
    6474            1 : GUCArrayReset(ArrayType *array)
    6475              : {
    6476              :     ArrayType  *newarray;
    6477              :     int         index;
    6478              : 
    6479              :     /* if array is currently null, nothing to do */
    6480            1 :     if (!array)
    6481            0 :         return NULL;
    6482              : 
    6483              :     /* if we're superuser, we can delete everything, so just do it */
    6484            1 :     if (superuser())
    6485            0 :         return NULL;
    6486              : 
    6487            1 :     newarray = NULL;
    6488            1 :     index = 1;
    6489              : 
    6490            3 :     for (int i = 1; i <= ARR_DIMS(array)[0]; i++)
    6491              :     {
    6492              :         Datum       d;
    6493              :         char       *val;
    6494              :         char       *eqsgn;
    6495              :         bool        isnull;
    6496              : 
    6497            2 :         d = array_ref(array, 1, &i,
    6498              :                       -1 /* varlenarray */ ,
    6499              :                       -1 /* TEXT's typlen */ ,
    6500              :                       false /* TEXT's typbyval */ ,
    6501              :                       TYPALIGN_INT /* TEXT's typalign */ ,
    6502              :                       &isnull);
    6503            2 :         if (isnull)
    6504            1 :             continue;
    6505            2 :         val = TextDatumGetCString(d);
    6506              : 
    6507            2 :         eqsgn = strchr(val, '=');
    6508            2 :         *eqsgn = '\0';
    6509              : 
    6510              :         /* skip if we have permission to delete it */
    6511            2 :         if (validate_option_array_item(val, NULL, true))
    6512            1 :             continue;
    6513              : 
    6514              :         /* else add it to the output array */
    6515            1 :         if (newarray)
    6516            0 :             newarray = array_set(newarray, 1, &index,
    6517              :                                  d,
    6518              :                                  false,
    6519              :                                  -1 /* varlenarray */ ,
    6520              :                                  -1 /* TEXT's typlen */ ,
    6521              :                                  false /* TEXT's typbyval */ ,
    6522              :                                  TYPALIGN_INT /* TEXT's typalign */ );
    6523              :         else
    6524            1 :             newarray = construct_array_builtin(&d, 1, TEXTOID);
    6525              : 
    6526            1 :         index++;
    6527            1 :         pfree(val);
    6528              :     }
    6529              : 
    6530            1 :     return newarray;
    6531              : }
    6532              : 
    6533              : /*
    6534              :  * Validate a proposed option setting for GUCArrayAdd/Delete/Reset.
    6535              :  *
    6536              :  * name is the option name.  value is the proposed value for the Add case,
    6537              :  * or NULL for the Delete/Reset cases.  If skipIfNoPermissions is true, it's
    6538              :  * not an error to have no permissions to set the option.
    6539              :  *
    6540              :  * Returns true if OK, false if skipIfNoPermissions is true and user does not
    6541              :  * have permission to change this option (all other error cases result in an
    6542              :  * error being thrown).
    6543              :  */
    6544              : static bool
    6545          753 : validate_option_array_item(const char *name, const char *value,
    6546              :                            bool skipIfNoPermissions)
    6547              : 
    6548              : {
    6549              :     struct config_generic *gconf;
    6550              :     bool        reset_custom;
    6551              : 
    6552              :     /*
    6553              :      * There are three cases to consider:
    6554              :      *
    6555              :      * name is a known GUC variable.  Check the value normally, check
    6556              :      * permissions normally (i.e., allow if variable is USERSET, or if it's
    6557              :      * SUSET and user is superuser or holds ACL_SET permissions).
    6558              :      *
    6559              :      * name is not known, but exists or can be created as a placeholder (i.e.,
    6560              :      * it has a valid custom name).  We allow this case if you're a superuser,
    6561              :      * otherwise not.  Superusers are assumed to know what they're doing. We
    6562              :      * can't allow it for other users, because when the placeholder is
    6563              :      * resolved it might turn out to be a SUSET variable.  (With currently
    6564              :      * available infrastructure, we can actually handle such cases within the
    6565              :      * current session --- but once an entry is made in pg_db_role_setting,
    6566              :      * it's assumed to be fully validated.)
    6567              :      *
    6568              :      * name is not known and can't be created as a placeholder.  Throw error,
    6569              :      * unless skipIfNoPermissions or reset_custom is true.  If reset_custom is
    6570              :      * true, this is a RESET or RESET ALL operation for an unknown custom GUC
    6571              :      * with a reserved prefix, in which case we want to fall through to the
    6572              :      * placeholder case described in the preceding paragraph (else there'd be
    6573              :      * no way for users to remove them).  Otherwise, return false.
    6574              :      */
    6575          753 :     reset_custom = (!value && valid_custom_variable_name(name));
    6576          753 :     gconf = find_option(name, true, skipIfNoPermissions || reset_custom, ERROR);
    6577          750 :     if (!gconf && !reset_custom)
    6578              :     {
    6579              :         /* not known, failed to make a placeholder */
    6580            0 :         return false;
    6581              :     }
    6582              : 
    6583          750 :     if (!gconf || gconf->flags & GUC_CUSTOM_PLACEHOLDER)
    6584              :     {
    6585              :         /*
    6586              :          * We cannot do any meaningful check on the value, so only permissions
    6587              :          * are useful to check.
    6588              :          */
    6589            6 :         if (superuser() ||
    6590            0 :             pg_parameter_aclcheck(name, GetUserId(), ACL_SET) == ACLCHECK_OK)
    6591            6 :             return true;
    6592            0 :         if (skipIfNoPermissions)
    6593            0 :             return false;
    6594            0 :         ereport(ERROR,
    6595              :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    6596              :                  errmsg("permission denied to set parameter \"%s\"", name)));
    6597              :     }
    6598              : 
    6599              :     /* manual permissions check so we can avoid an error being thrown */
    6600          744 :     if (gconf->context == PGC_USERSET)
    6601              :          /* ok */ ;
    6602          224 :     else if (gconf->context == PGC_SUSET &&
    6603          118 :              (superuser() ||
    6604            6 :               pg_parameter_aclcheck(name, GetUserId(), ACL_SET) == ACLCHECK_OK))
    6605              :          /* ok */ ;
    6606            2 :     else if (skipIfNoPermissions)
    6607            1 :         return false;
    6608              :     /* if a permissions error should be thrown, let set_config_option do it */
    6609              : 
    6610              :     /* test for permissions and valid option value */
    6611          743 :     (void) set_config_option(name, value,
    6612          743 :                              superuser() ? PGC_SUSET : PGC_USERSET,
    6613              :                              PGC_S_TEST, GUC_ACTION_SET, false, 0, false);
    6614              : 
    6615          742 :     return true;
    6616              : }
    6617              : 
    6618              : 
    6619              : /*
    6620              :  * Called by check_hooks that want to override the normal
    6621              :  * ERRCODE_INVALID_PARAMETER_VALUE SQLSTATE for check hook failures.
    6622              :  *
    6623              :  * Note that GUC_check_errmsg() etc are just macros that result in a direct
    6624              :  * assignment to the associated variables.  That is ugly, but forced by the
    6625              :  * limitations of C's macro mechanisms.
    6626              :  */
    6627              : void
    6628           24 : GUC_check_errcode(int sqlerrcode)
    6629              : {
    6630           24 :     GUC_check_errcode_value = sqlerrcode;
    6631           24 : }
    6632              : 
    6633              : 
    6634              : /*
    6635              :  * Convenience functions to manage calling a variable's check_hook.
    6636              :  * These mostly take care of the protocol for letting check hooks supply
    6637              :  * portions of the error report on failure.
    6638              :  */
    6639              : 
    6640              : static bool
    6641       237607 : call_bool_check_hook(const struct config_generic *conf, bool *newval, void **extra,
    6642              :                      GucSource source, int elevel)
    6643              : {
    6644              :     /* Quick success if no hook */
    6645       237607 :     if (!conf->_bool.check_hook)
    6646       215945 :         return true;
    6647              : 
    6648              :     /* Reset variables that might be set by hook */
    6649        21662 :     GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
    6650        21662 :     GUC_check_errmsg_string = NULL;
    6651        21662 :     GUC_check_errdetail_string = NULL;
    6652        21662 :     GUC_check_errhint_string = NULL;
    6653              : 
    6654        21662 :     if (!conf->_bool.check_hook(newval, extra, source))
    6655              :     {
    6656           15 :         ereport(elevel,
    6657              :                 (errcode(GUC_check_errcode_value),
    6658              :                  GUC_check_errmsg_string ?
    6659              :                  errmsg_internal("%s", GUC_check_errmsg_string) :
    6660              :                  errmsg("invalid value for parameter \"%s\": %d",
    6661              :                         conf->name, (int) *newval),
    6662              :                  GUC_check_errdetail_string ?
    6663              :                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
    6664              :                  GUC_check_errhint_string ?
    6665              :                  errhint("%s", GUC_check_errhint_string) : 0));
    6666              :         /* Flush strings created in ErrorContext (ereport might not have) */
    6667            0 :         FlushErrorState();
    6668            0 :         return false;
    6669              :     }
    6670              : 
    6671        21647 :     return true;
    6672              : }
    6673              : 
    6674              : static bool
    6675       244645 : call_int_check_hook(const struct config_generic *conf, int *newval, void **extra,
    6676              :                     GucSource source, int elevel)
    6677              : {
    6678              :     /* Quick success if no hook */
    6679       244645 :     if (!conf->_int.check_hook)
    6680       213681 :         return true;
    6681              : 
    6682              :     /* Reset variables that might be set by hook */
    6683        30964 :     GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
    6684        30964 :     GUC_check_errmsg_string = NULL;
    6685        30964 :     GUC_check_errdetail_string = NULL;
    6686        30964 :     GUC_check_errhint_string = NULL;
    6687              : 
    6688        30964 :     if (!conf->_int.check_hook(newval, extra, source))
    6689              :     {
    6690            0 :         ereport(elevel,
    6691              :                 (errcode(GUC_check_errcode_value),
    6692              :                  GUC_check_errmsg_string ?
    6693              :                  errmsg_internal("%s", GUC_check_errmsg_string) :
    6694              :                  errmsg("invalid value for parameter \"%s\": %d",
    6695              :                         conf->name, *newval),
    6696              :                  GUC_check_errdetail_string ?
    6697              :                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
    6698              :                  GUC_check_errhint_string ?
    6699              :                  errhint("%s", GUC_check_errhint_string) : 0));
    6700              :         /* Flush strings created in ErrorContext (ereport might not have) */
    6701            0 :         FlushErrorState();
    6702            0 :         return false;
    6703              :     }
    6704              : 
    6705        30964 :     return true;
    6706              : }
    6707              : 
    6708              : static bool
    6709        36461 : call_real_check_hook(const struct config_generic *conf, double *newval, void **extra,
    6710              :                      GucSource source, int elevel)
    6711              : {
    6712              :     /* Quick success if no hook */
    6713        36461 :     if (!conf->_real.check_hook)
    6714        35269 :         return true;
    6715              : 
    6716              :     /* Reset variables that might be set by hook */
    6717         1192 :     GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
    6718         1192 :     GUC_check_errmsg_string = NULL;
    6719         1192 :     GUC_check_errdetail_string = NULL;
    6720         1192 :     GUC_check_errhint_string = NULL;
    6721              : 
    6722         1192 :     if (!conf->_real.check_hook(newval, extra, source))
    6723              :     {
    6724            0 :         ereport(elevel,
    6725              :                 (errcode(GUC_check_errcode_value),
    6726              :                  GUC_check_errmsg_string ?
    6727              :                  errmsg_internal("%s", GUC_check_errmsg_string) :
    6728              :                  errmsg("invalid value for parameter \"%s\": %g",
    6729              :                         conf->name, *newval),
    6730              :                  GUC_check_errdetail_string ?
    6731              :                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
    6732              :                  GUC_check_errhint_string ?
    6733              :                  errhint("%s", GUC_check_errhint_string) : 0));
    6734              :         /* Flush strings created in ErrorContext (ereport might not have) */
    6735            0 :         FlushErrorState();
    6736            0 :         return false;
    6737              :     }
    6738              : 
    6739         1192 :     return true;
    6740              : }
    6741              : 
    6742              : static bool
    6743       471938 : call_string_check_hook(const struct config_generic *conf, char **newval, void **extra,
    6744              :                        GucSource source, int elevel)
    6745              : {
    6746       471938 :     volatile bool result = true;
    6747              : 
    6748              :     /* Quick success if no hook */
    6749       471938 :     if (!conf->_string.check_hook)
    6750        78312 :         return true;
    6751              : 
    6752              :     /*
    6753              :      * If elevel is ERROR, or if the check_hook itself throws an elog
    6754              :      * (undesirable, but not always avoidable), make sure we don't leak the
    6755              :      * already-malloc'd newval string.
    6756              :      */
    6757       393626 :     PG_TRY();
    6758              :     {
    6759              :         /* Reset variables that might be set by hook */
    6760       393626 :         GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
    6761       393626 :         GUC_check_errmsg_string = NULL;
    6762       393626 :         GUC_check_errdetail_string = NULL;
    6763       393626 :         GUC_check_errhint_string = NULL;
    6764              : 
    6765       393626 :         if (!conf->_string.check_hook(newval, extra, source))
    6766              :         {
    6767           53 :             ereport(elevel,
    6768              :                     (errcode(GUC_check_errcode_value),
    6769              :                      GUC_check_errmsg_string ?
    6770              :                      errmsg_internal("%s", GUC_check_errmsg_string) :
    6771              :                      errmsg("invalid value for parameter \"%s\": \"%s\"",
    6772              :                             conf->name, *newval ? *newval : ""),
    6773              :                      GUC_check_errdetail_string ?
    6774              :                      errdetail_internal("%s", GUC_check_errdetail_string) : 0,
    6775              :                      GUC_check_errhint_string ?
    6776              :                      errhint("%s", GUC_check_errhint_string) : 0));
    6777              :             /* Flush strings created in ErrorContext (ereport might not have) */
    6778            0 :             FlushErrorState();
    6779            0 :             result = false;
    6780              :         }
    6781              :     }
    6782           56 :     PG_CATCH();
    6783              :     {
    6784           56 :         guc_free(*newval);
    6785           56 :         PG_RE_THROW();
    6786              :     }
    6787       393570 :     PG_END_TRY();
    6788              : 
    6789       393570 :     return result;
    6790              : }
    6791              : 
    6792              : static bool
    6793        93668 : call_enum_check_hook(const struct config_generic *conf, int *newval, void **extra,
    6794              :                      GucSource source, int elevel)
    6795              : {
    6796              :     /* Quick success if no hook */
    6797        93668 :     if (!conf->_enum.check_hook)
    6798        83494 :         return true;
    6799              : 
    6800              :     /* Reset variables that might be set by hook */
    6801        10174 :     GUC_check_errcode_value = ERRCODE_INVALID_PARAMETER_VALUE;
    6802        10174 :     GUC_check_errmsg_string = NULL;
    6803        10174 :     GUC_check_errdetail_string = NULL;
    6804        10174 :     GUC_check_errhint_string = NULL;
    6805              : 
    6806        10174 :     if (!conf->_enum.check_hook(newval, extra, source))
    6807              :     {
    6808            1 :         ereport(elevel,
    6809              :                 (errcode(GUC_check_errcode_value),
    6810              :                  GUC_check_errmsg_string ?
    6811              :                  errmsg_internal("%s", GUC_check_errmsg_string) :
    6812              :                  errmsg("invalid value for parameter \"%s\": \"%s\"",
    6813              :                         conf->name,
    6814              :                         config_enum_lookup_by_value(conf, *newval)),
    6815              :                  GUC_check_errdetail_string ?
    6816              :                  errdetail_internal("%s", GUC_check_errdetail_string) : 0,
    6817              :                  GUC_check_errhint_string ?
    6818              :                  errhint("%s", GUC_check_errhint_string) : 0));
    6819              :         /* Flush strings created in ErrorContext (ereport might not have) */
    6820            0 :         FlushErrorState();
    6821            0 :         return false;
    6822              :     }
    6823              : 
    6824        10173 :     return true;
    6825              : }
        

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