LCOV - code coverage report
Current view: top level - src/backend/executor - functions.c (source / functions) Hit Total Coverage
Test: PostgreSQL 18beta1 Lines: 686 723 94.9 %
Date: 2025-06-27 20:17:18 Functions: 33 33 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * functions.c
       4             :  *    Execution of SQL-language functions
       5             :  *
       6             :  * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
       7             :  * Portions Copyright (c) 1994, Regents of the University of California
       8             :  *
       9             :  *
      10             :  * IDENTIFICATION
      11             :  *    src/backend/executor/functions.c
      12             :  *
      13             :  *-------------------------------------------------------------------------
      14             :  */
      15             : #include "postgres.h"
      16             : 
      17             : #include "access/htup_details.h"
      18             : #include "access/xact.h"
      19             : #include "catalog/pg_proc.h"
      20             : #include "catalog/pg_type.h"
      21             : #include "executor/functions.h"
      22             : #include "funcapi.h"
      23             : #include "miscadmin.h"
      24             : #include "nodes/makefuncs.h"
      25             : #include "nodes/nodeFuncs.h"
      26             : #include "parser/parse_coerce.h"
      27             : #include "parser/parse_collate.h"
      28             : #include "parser/parse_func.h"
      29             : #include "rewrite/rewriteHandler.h"
      30             : #include "storage/proc.h"
      31             : #include "tcop/utility.h"
      32             : #include "utils/builtins.h"
      33             : #include "utils/datum.h"
      34             : #include "utils/funccache.h"
      35             : #include "utils/lsyscache.h"
      36             : #include "utils/memutils.h"
      37             : #include "utils/plancache.h"
      38             : #include "utils/snapmgr.h"
      39             : #include "utils/syscache.h"
      40             : 
      41             : 
      42             : /*
      43             :  * Specialized DestReceiver for collecting query output in a SQL function
      44             :  */
      45             : typedef struct
      46             : {
      47             :     DestReceiver pub;           /* publicly-known function pointers */
      48             :     Tuplestorestate *tstore;    /* where to put result tuples, or NULL */
      49             :     JunkFilter *filter;         /* filter to convert tuple type */
      50             : } DR_sqlfunction;
      51             : 
      52             : /*
      53             :  * We have an execution_state record for each query in a function.  Each
      54             :  * record references a plantree for its query.  If the query is currently in
      55             :  * F_EXEC_RUN state then there's a QueryDesc too.
      56             :  *
      57             :  * The "next" fields chain together all the execution_state records generated
      58             :  * from a single original parsetree.  (There will only be more than one in
      59             :  * case of rule expansion of the original parsetree.)  The chain structure is
      60             :  * quite vestigial at this point, because we allocate the records in an array
      61             :  * for ease of memory management.  But we'll get rid of it some other day.
      62             :  */
      63             : typedef enum
      64             : {
      65             :     F_EXEC_START, F_EXEC_RUN, F_EXEC_DONE,
      66             : } ExecStatus;
      67             : 
      68             : typedef struct execution_state
      69             : {
      70             :     struct execution_state *next;
      71             :     ExecStatus  status;
      72             :     bool        setsResult;     /* true if this query produces func's result */
      73             :     bool        lazyEval;       /* true if should fetch one row at a time */
      74             :     PlannedStmt *stmt;          /* plan for this query */
      75             :     QueryDesc  *qd;             /* null unless status == RUN */
      76             : } execution_state;
      77             : 
      78             : 
      79             : /*
      80             :  * Data associated with a SQL-language function is kept in two main
      81             :  * data structures:
      82             :  *
      83             :  * 1. SQLFunctionHashEntry is a long-lived (potentially session-lifespan)
      84             :  * struct that holds all the info we need out of the function's pg_proc row.
      85             :  * In addition it holds pointers to CachedPlanSource(s) that manage creation
      86             :  * of plans for the query(s) within the function.  A SQLFunctionHashEntry is
      87             :  * potentially shared across multiple concurrent executions of the function,
      88             :  * so it must contain no execution-specific state; but its use_count must
      89             :  * reflect the number of SQLFunctionCache structs pointing at it.
      90             :  * If the function's pg_proc row is updated, we throw away and regenerate
      91             :  * the SQLFunctionHashEntry and subsidiary data.  (Also note that if the
      92             :  * function is polymorphic or used as a trigger, there is a separate
      93             :  * SQLFunctionHashEntry for each usage, so that we need consider only one
      94             :  * set of relevant data types.)  The struct itself is in memory managed by
      95             :  * funccache.c, and its subsidiary data is kept in one of two contexts:
      96             :  *  * pcontext ("parse context") holds the raw parse trees or Query trees
      97             :  *    that we read from the pg_proc row.  These will be converted to
      98             :  *    CachedPlanSources as they are needed.  Once the last one is converted,
      99             :  *    pcontext can be freed.
     100             :  *  * hcontext ("hash context") holds everything else belonging to the
     101             :  *    SQLFunctionHashEntry.
     102             :  *
     103             :  * 2. SQLFunctionCache is subsidiary data for a single FmgrInfo struct.
     104             :  * It is pointed to by the fn_extra field of the FmgrInfo struct, and is
     105             :  * always allocated in the FmgrInfo's fn_mcxt.  It holds a reference to
     106             :  * the CachedPlan for the current query, and other execution-specific data.
     107             :  * A few subsidiary items such as the ParamListInfo object are also kept
     108             :  * directly in fn_mcxt (which is also called fcontext here).  But most
     109             :  * subsidiary data is in jfcontext or subcontext.
     110             :  */
     111             : 
     112             : typedef struct SQLFunctionHashEntry
     113             : {
     114             :     CachedFunction cfunc;       /* fields managed by funccache.c */
     115             : 
     116             :     char       *fname;          /* function name (for error msgs) */
     117             :     char       *src;            /* function body text (for error msgs) */
     118             : 
     119             :     SQLFunctionParseInfoPtr pinfo;  /* data for parser callback hooks */
     120             :     int16      *argtyplen;      /* lengths of the input argument types */
     121             : 
     122             :     Oid         rettype;        /* actual return type */
     123             :     int16       typlen;         /* length of the return type */
     124             :     bool        typbyval;       /* true if return type is pass by value */
     125             :     bool        returnsSet;     /* true if returning multiple rows */
     126             :     bool        returnsTuple;   /* true if returning whole tuple result */
     127             :     bool        readonly_func;  /* true to run in "read only" mode */
     128             :     char        prokind;        /* prokind from pg_proc row */
     129             : 
     130             :     TupleDesc   rettupdesc;     /* result tuple descriptor */
     131             : 
     132             :     List       *source_list;    /* RawStmts or Queries read from pg_proc */
     133             :     int         num_queries;    /* original length of source_list */
     134             :     bool        raw_source;     /* true if source_list contains RawStmts */
     135             : 
     136             :     List       *plansource_list;    /* CachedPlanSources for fn's queries */
     137             : 
     138             :     MemoryContext pcontext;     /* memory context holding source_list */
     139             :     MemoryContext hcontext;     /* memory context holding all else */
     140             : } SQLFunctionHashEntry;
     141             : 
     142             : typedef struct SQLFunctionCache
     143             : {
     144             :     SQLFunctionHashEntry *func; /* associated SQLFunctionHashEntry */
     145             : 
     146             :     bool        lazyEvalOK;     /* true if lazyEval is safe */
     147             :     bool        shutdown_reg;   /* true if registered shutdown callback */
     148             :     bool        lazyEval;       /* true if using lazyEval for result query */
     149             :     bool        randomAccess;   /* true if tstore needs random access */
     150             :     bool        ownSubcontext;  /* is subcontext really a separate context? */
     151             : 
     152             :     ParamListInfo paramLI;      /* Param list representing current args */
     153             : 
     154             :     Tuplestorestate *tstore;    /* where we accumulate result for a SRF */
     155             :     MemoryContext tscontext;    /* memory context that tstore should be in */
     156             : 
     157             :     JunkFilter *junkFilter;     /* will be NULL if function returns VOID */
     158             :     int         jf_generation;  /* tracks whether junkFilter is up-to-date */
     159             : 
     160             :     /*
     161             :      * While executing a particular query within the function, cplan is the
     162             :      * CachedPlan we've obtained for that query, and eslist is a chain of
     163             :      * execution_state records for the individual plans within the CachedPlan.
     164             :      * If eslist is not NULL at entry to fmgr_sql, then we are resuming
     165             :      * execution of a lazyEval-mode set-returning function.
     166             :      *
     167             :      * next_query_index is the 0-based index of the next CachedPlanSource to
     168             :      * get a CachedPlan from.
     169             :      */
     170             :     CachedPlan *cplan;          /* Plan for current query, if any */
     171             :     ResourceOwner cowner;       /* CachedPlan is registered with this owner */
     172             :     int         next_query_index;   /* index of next CachedPlanSource to run */
     173             : 
     174             :     execution_state *eslist;    /* chain of execution_state records */
     175             :     execution_state *esarray;   /* storage for eslist */
     176             :     int         esarray_len;    /* allocated length of esarray[] */
     177             : 
     178             :     /* if positive, this is the 1-based index of the query we're processing */
     179             :     int         error_query_index;
     180             : 
     181             :     MemoryContext fcontext;     /* memory context holding this struct and all
     182             :                                  * subsidiary data */
     183             :     MemoryContext jfcontext;    /* subsidiary memory context holding
     184             :                                  * junkFilter, result slot, and related data */
     185             :     MemoryContext subcontext;   /* subsidiary memory context for sub-executor */
     186             : 
     187             :     /* Callback to release our use-count on the SQLFunctionHashEntry */
     188             :     MemoryContextCallback mcb;
     189             : } SQLFunctionCache;
     190             : 
     191             : typedef SQLFunctionCache *SQLFunctionCachePtr;
     192             : 
     193             : 
     194             : /* non-export function prototypes */
     195             : static Node *sql_fn_param_ref(ParseState *pstate, ParamRef *pref);
     196             : static Node *sql_fn_post_column_ref(ParseState *pstate,
     197             :                                     ColumnRef *cref, Node *var);
     198             : static Node *sql_fn_make_param(SQLFunctionParseInfoPtr pinfo,
     199             :                                int paramno, int location);
     200             : static Node *sql_fn_resolve_param_name(SQLFunctionParseInfoPtr pinfo,
     201             :                                        const char *paramname, int location);
     202             : static SQLFunctionCache *init_sql_fcache(FunctionCallInfo fcinfo,
     203             :                                          bool lazyEvalOK);
     204             : static bool init_execution_state(SQLFunctionCachePtr fcache);
     205             : static void prepare_next_query(SQLFunctionHashEntry *func);
     206             : static void sql_compile_callback(FunctionCallInfo fcinfo,
     207             :                                  HeapTuple procedureTuple,
     208             :                                  const CachedFunctionHashKey *hashkey,
     209             :                                  CachedFunction *cfunc,
     210             :                                  bool forValidator);
     211             : static void sql_delete_callback(CachedFunction *cfunc);
     212             : static void sql_postrewrite_callback(List *querytree_list, void *arg);
     213             : static void postquel_start(execution_state *es, SQLFunctionCachePtr fcache);
     214             : static bool postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache);
     215             : static void postquel_end(execution_state *es, SQLFunctionCachePtr fcache);
     216             : static void postquel_sub_params(SQLFunctionCachePtr fcache,
     217             :                                 FunctionCallInfo fcinfo);
     218             : static Datum postquel_get_single_result(TupleTableSlot *slot,
     219             :                                         FunctionCallInfo fcinfo,
     220             :                                         SQLFunctionCachePtr fcache);
     221             : static void sql_compile_error_callback(void *arg);
     222             : static void sql_exec_error_callback(void *arg);
     223             : static void ShutdownSQLFunction(Datum arg);
     224             : static void RemoveSQLFunctionCache(void *arg);
     225             : static void check_sql_fn_statement(List *queryTreeList);
     226             : static bool check_sql_stmt_retval(List *queryTreeList,
     227             :                                   Oid rettype, TupleDesc rettupdesc,
     228             :                                   char prokind, bool insertDroppedCols);
     229             : static bool coerce_fn_result_column(TargetEntry *src_tle,
     230             :                                     Oid res_type, int32 res_typmod,
     231             :                                     bool tlist_is_modifiable,
     232             :                                     List **upper_tlist,
     233             :                                     bool *upper_tlist_nontrivial);
     234             : static List *get_sql_fn_result_tlist(List *queryTreeList);
     235             : static void sqlfunction_startup(DestReceiver *self, int operation, TupleDesc typeinfo);
     236             : static bool sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self);
     237             : static void sqlfunction_shutdown(DestReceiver *self);
     238             : static void sqlfunction_destroy(DestReceiver *self);
     239             : 
     240             : 
     241             : /*
     242             :  * Prepare the SQLFunctionParseInfo struct for parsing a SQL function body
     243             :  *
     244             :  * This includes resolving actual types of polymorphic arguments.
     245             :  *
     246             :  * call_expr can be passed as NULL, but then we will fail if there are any
     247             :  * polymorphic arguments.
     248             :  */
     249             : SQLFunctionParseInfoPtr
     250        7134 : prepare_sql_fn_parse_info(HeapTuple procedureTuple,
     251             :                           Node *call_expr,
     252             :                           Oid inputCollation)
     253             : {
     254             :     SQLFunctionParseInfoPtr pinfo;
     255        7134 :     Form_pg_proc procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
     256             :     int         nargs;
     257             : 
     258        7134 :     pinfo = (SQLFunctionParseInfoPtr) palloc0(sizeof(SQLFunctionParseInfo));
     259             : 
     260             :     /* Function's name (only) can be used to qualify argument names */
     261        7134 :     pinfo->fname = pstrdup(NameStr(procedureStruct->proname));
     262             : 
     263             :     /* Save the function's input collation */
     264        7134 :     pinfo->collation = inputCollation;
     265             : 
     266             :     /*
     267             :      * Copy input argument types from the pg_proc entry, then resolve any
     268             :      * polymorphic types.
     269             :      */
     270        7134 :     pinfo->nargs = nargs = procedureStruct->pronargs;
     271        7134 :     if (nargs > 0)
     272             :     {
     273             :         Oid        *argOidVect;
     274             :         int         argnum;
     275             : 
     276        5896 :         argOidVect = (Oid *) palloc(nargs * sizeof(Oid));
     277        5896 :         memcpy(argOidVect,
     278        5896 :                procedureStruct->proargtypes.values,
     279             :                nargs * sizeof(Oid));
     280             : 
     281       15698 :         for (argnum = 0; argnum < nargs; argnum++)
     282             :         {
     283        9802 :             Oid         argtype = argOidVect[argnum];
     284             : 
     285        9802 :             if (IsPolymorphicType(argtype))
     286             :             {
     287        2592 :                 argtype = get_call_expr_argtype(call_expr, argnum);
     288        2592 :                 if (argtype == InvalidOid)
     289           0 :                     ereport(ERROR,
     290             :                             (errcode(ERRCODE_DATATYPE_MISMATCH),
     291             :                              errmsg("could not determine actual type of argument declared %s",
     292             :                                     format_type_be(argOidVect[argnum]))));
     293        2592 :                 argOidVect[argnum] = argtype;
     294             :             }
     295             :         }
     296             : 
     297        5896 :         pinfo->argtypes = argOidVect;
     298             :     }
     299             : 
     300             :     /*
     301             :      * Collect names of arguments, too, if any
     302             :      */
     303        7134 :     if (nargs > 0)
     304             :     {
     305             :         Datum       proargnames;
     306             :         Datum       proargmodes;
     307             :         int         n_arg_names;
     308             :         bool        isNull;
     309             : 
     310        5896 :         proargnames = SysCacheGetAttr(PROCNAMEARGSNSP, procedureTuple,
     311             :                                       Anum_pg_proc_proargnames,
     312             :                                       &isNull);
     313        5896 :         if (isNull)
     314        4004 :             proargnames = PointerGetDatum(NULL);    /* just to be sure */
     315             : 
     316        5896 :         proargmodes = SysCacheGetAttr(PROCNAMEARGSNSP, procedureTuple,
     317             :                                       Anum_pg_proc_proargmodes,
     318             :                                       &isNull);
     319        5896 :         if (isNull)
     320        5262 :             proargmodes = PointerGetDatum(NULL);    /* just to be sure */
     321             : 
     322        5896 :         n_arg_names = get_func_input_arg_names(proargnames, proargmodes,
     323             :                                                &pinfo->argnames);
     324             : 
     325             :         /* Paranoia: ignore the result if too few array entries */
     326        5896 :         if (n_arg_names < nargs)
     327        4004 :             pinfo->argnames = NULL;
     328             :     }
     329             :     else
     330        1238 :         pinfo->argnames = NULL;
     331             : 
     332        7134 :     return pinfo;
     333             : }
     334             : 
     335             : /*
     336             :  * Parser setup hook for parsing a SQL function body.
     337             :  */
     338             : void
     339       12110 : sql_fn_parser_setup(struct ParseState *pstate, SQLFunctionParseInfoPtr pinfo)
     340             : {
     341       12110 :     pstate->p_pre_columnref_hook = NULL;
     342       12110 :     pstate->p_post_columnref_hook = sql_fn_post_column_ref;
     343       12110 :     pstate->p_paramref_hook = sql_fn_param_ref;
     344             :     /* no need to use p_coerce_param_hook */
     345       12110 :     pstate->p_ref_hook_state = pinfo;
     346       12110 : }
     347             : 
     348             : /*
     349             :  * sql_fn_post_column_ref       parser callback for ColumnRefs
     350             :  */
     351             : static Node *
     352        8958 : sql_fn_post_column_ref(ParseState *pstate, ColumnRef *cref, Node *var)
     353             : {
     354        8958 :     SQLFunctionParseInfoPtr pinfo = (SQLFunctionParseInfoPtr) pstate->p_ref_hook_state;
     355             :     int         nnames;
     356             :     Node       *field1;
     357        8958 :     Node       *subfield = NULL;
     358             :     const char *name1;
     359        8958 :     const char *name2 = NULL;
     360             :     Node       *param;
     361             : 
     362             :     /*
     363             :      * Never override a table-column reference.  This corresponds to
     364             :      * considering the parameter names to appear in a scope outside the
     365             :      * individual SQL commands, which is what we want.
     366             :      */
     367        8958 :     if (var != NULL)
     368        7528 :         return NULL;
     369             : 
     370             :     /*----------
     371             :      * The allowed syntaxes are:
     372             :      *
     373             :      * A        A = parameter name
     374             :      * A.B      A = function name, B = parameter name
     375             :      *          OR: A = record-typed parameter name, B = field name
     376             :      *          (the first possibility takes precedence)
     377             :      * A.B.C    A = function name, B = record-typed parameter name,
     378             :      *          C = field name
     379             :      * A.*      Whole-row reference to composite parameter A.
     380             :      * A.B.*    Same, with A = function name, B = parameter name
     381             :      *
     382             :      * Here, it's sufficient to ignore the "*" in the last two cases --- the
     383             :      * main parser will take care of expanding the whole-row reference.
     384             :      *----------
     385             :      */
     386        1430 :     nnames = list_length(cref->fields);
     387             : 
     388        1430 :     if (nnames > 3)
     389           0 :         return NULL;
     390             : 
     391        1430 :     if (IsA(llast(cref->fields), A_Star))
     392          42 :         nnames--;
     393             : 
     394        1430 :     field1 = (Node *) linitial(cref->fields);
     395        1430 :     name1 = strVal(field1);
     396        1430 :     if (nnames > 1)
     397             :     {
     398         156 :         subfield = (Node *) lsecond(cref->fields);
     399         156 :         name2 = strVal(subfield);
     400             :     }
     401             : 
     402        1430 :     if (nnames == 3)
     403             :     {
     404             :         /*
     405             :          * Three-part name: if the first part doesn't match the function name,
     406             :          * we can fail immediately. Otherwise, look up the second part, and
     407             :          * take the third part to be a field reference.
     408             :          */
     409          24 :         if (strcmp(name1, pinfo->fname) != 0)
     410           0 :             return NULL;
     411             : 
     412          24 :         param = sql_fn_resolve_param_name(pinfo, name2, cref->location);
     413             : 
     414          24 :         subfield = (Node *) lthird(cref->fields);
     415             :         Assert(IsA(subfield, String));
     416             :     }
     417        1406 :     else if (nnames == 2 && strcmp(name1, pinfo->fname) == 0)
     418             :     {
     419             :         /*
     420             :          * Two-part name with first part matching function name: first see if
     421             :          * second part matches any parameter name.
     422             :          */
     423          24 :         param = sql_fn_resolve_param_name(pinfo, name2, cref->location);
     424             : 
     425          24 :         if (param)
     426             :         {
     427             :             /* Yes, so this is a parameter reference, no subfield */
     428          24 :             subfield = NULL;
     429             :         }
     430             :         else
     431             :         {
     432             :             /* No, so try to match as parameter name and subfield */
     433           0 :             param = sql_fn_resolve_param_name(pinfo, name1, cref->location);
     434             :         }
     435             :     }
     436             :     else
     437             :     {
     438             :         /* Single name, or parameter name followed by subfield */
     439        1382 :         param = sql_fn_resolve_param_name(pinfo, name1, cref->location);
     440             :     }
     441             : 
     442        1430 :     if (!param)
     443           0 :         return NULL;            /* No match */
     444             : 
     445        1430 :     if (subfield)
     446             :     {
     447             :         /*
     448             :          * Must be a reference to a field of a composite parameter; otherwise
     449             :          * ParseFuncOrColumn will return NULL, and we'll fail back at the
     450             :          * caller.
     451             :          */
     452         132 :         param = ParseFuncOrColumn(pstate,
     453         132 :                                   list_make1(subfield),
     454         132 :                                   list_make1(param),
     455             :                                   pstate->p_last_srf,
     456             :                                   NULL,
     457             :                                   false,
     458             :                                   cref->location);
     459             :     }
     460             : 
     461        1430 :     return param;
     462             : }
     463             : 
     464             : /*
     465             :  * sql_fn_param_ref     parser callback for ParamRefs ($n symbols)
     466             :  */
     467             : static Node *
     468       21816 : sql_fn_param_ref(ParseState *pstate, ParamRef *pref)
     469             : {
     470       21816 :     SQLFunctionParseInfoPtr pinfo = (SQLFunctionParseInfoPtr) pstate->p_ref_hook_state;
     471       21816 :     int         paramno = pref->number;
     472             : 
     473             :     /* Check parameter number is valid */
     474       21816 :     if (paramno <= 0 || paramno > pinfo->nargs)
     475           6 :         return NULL;            /* unknown parameter number */
     476             : 
     477       21810 :     return sql_fn_make_param(pinfo, paramno, pref->location);
     478             : }
     479             : 
     480             : /*
     481             :  * sql_fn_make_param        construct a Param node for the given paramno
     482             :  */
     483             : static Node *
     484       23240 : sql_fn_make_param(SQLFunctionParseInfoPtr pinfo,
     485             :                   int paramno, int location)
     486             : {
     487             :     Param      *param;
     488             : 
     489       23240 :     param = makeNode(Param);
     490       23240 :     param->paramkind = PARAM_EXTERN;
     491       23240 :     param->paramid = paramno;
     492       23240 :     param->paramtype = pinfo->argtypes[paramno - 1];
     493       23240 :     param->paramtypmod = -1;
     494       23240 :     param->paramcollid = get_typcollation(param->paramtype);
     495       23240 :     param->location = location;
     496             : 
     497             :     /*
     498             :      * If we have a function input collation, allow it to override the
     499             :      * type-derived collation for parameter symbols.  (XXX perhaps this should
     500             :      * not happen if the type collation is not default?)
     501             :      */
     502       23240 :     if (OidIsValid(pinfo->collation) && OidIsValid(param->paramcollid))
     503        2002 :         param->paramcollid = pinfo->collation;
     504             : 
     505       23240 :     return (Node *) param;
     506             : }
     507             : 
     508             : /*
     509             :  * Search for a function parameter of the given name; if there is one,
     510             :  * construct and return a Param node for it.  If not, return NULL.
     511             :  * Helper function for sql_fn_post_column_ref.
     512             :  */
     513             : static Node *
     514        1430 : sql_fn_resolve_param_name(SQLFunctionParseInfoPtr pinfo,
     515             :                           const char *paramname, int location)
     516             : {
     517             :     int         i;
     518             : 
     519        1430 :     if (pinfo->argnames == NULL)
     520           0 :         return NULL;
     521             : 
     522        1962 :     for (i = 0; i < pinfo->nargs; i++)
     523             :     {
     524        1962 :         if (pinfo->argnames[i] && strcmp(pinfo->argnames[i], paramname) == 0)
     525        1430 :             return sql_fn_make_param(pinfo, i + 1, location);
     526             :     }
     527             : 
     528           0 :     return NULL;
     529             : }
     530             : 
     531             : /*
     532             :  * Initialize the SQLFunctionCache for a SQL function
     533             :  */
     534             : static SQLFunctionCache *
     535       86946 : init_sql_fcache(FunctionCallInfo fcinfo, bool lazyEvalOK)
     536             : {
     537       86946 :     FmgrInfo   *finfo = fcinfo->flinfo;
     538             :     SQLFunctionHashEntry *func;
     539             :     SQLFunctionCache *fcache;
     540             : 
     541             :     /*
     542             :      * If this is the first execution for this FmgrInfo, set up a cache struct
     543             :      * (initially containing null pointers).  The cache must live as long as
     544             :      * the FmgrInfo, so it goes in fn_mcxt.  Also set up a memory context
     545             :      * callback that will be invoked when fn_mcxt is deleted.
     546             :      */
     547       86946 :     fcache = finfo->fn_extra;
     548       86946 :     if (fcache == NULL)
     549             :     {
     550             :         fcache = (SQLFunctionCache *)
     551       34048 :             MemoryContextAllocZero(finfo->fn_mcxt, sizeof(SQLFunctionCache));
     552       34048 :         fcache->fcontext = finfo->fn_mcxt;
     553       34048 :         fcache->mcb.func = RemoveSQLFunctionCache;
     554       34048 :         fcache->mcb.arg = fcache;
     555       34048 :         MemoryContextRegisterResetCallback(finfo->fn_mcxt, &fcache->mcb);
     556       34048 :         finfo->fn_extra = fcache;
     557             :     }
     558             : 
     559             :     /*
     560             :      * If we are resuming execution of a set-returning function, just keep
     561             :      * using the same cache.  We do not ask funccache.c to re-validate the
     562             :      * SQLFunctionHashEntry: we want to run to completion using the function's
     563             :      * initial definition.
     564             :      */
     565       86946 :     if (fcache->eslist != NULL)
     566             :     {
     567             :         Assert(fcache->func != NULL);
     568         988 :         return fcache;
     569             :     }
     570             : 
     571             :     /*
     572             :      * Look up, or re-validate, the long-lived hash entry.  Make the hash key
     573             :      * depend on the result of get_call_result_type() when that's composite,
     574             :      * so that we can safely assume that we'll build a new hash entry if the
     575             :      * composite rowtype changes.
     576             :      */
     577             :     func = (SQLFunctionHashEntry *)
     578       85958 :         cached_function_compile(fcinfo,
     579       85958 :                                 (CachedFunction *) fcache->func,
     580             :                                 sql_compile_callback,
     581             :                                 sql_delete_callback,
     582             :                                 sizeof(SQLFunctionHashEntry),
     583             :                                 true,
     584             :                                 false);
     585             : 
     586             :     /*
     587             :      * Install the hash pointer in the SQLFunctionCache, and increment its use
     588             :      * count to reflect that.  If cached_function_compile gave us back a
     589             :      * different hash entry than we were using before, we must decrement that
     590             :      * one's use count.
     591             :      */
     592       85952 :     if (func != fcache->func)
     593             :     {
     594       34042 :         if (fcache->func != NULL)
     595             :         {
     596             :             Assert(fcache->func->cfunc.use_count > 0);
     597           0 :             fcache->func->cfunc.use_count--;
     598             :         }
     599       34042 :         fcache->func = func;
     600       34042 :         func->cfunc.use_count++;
     601             :         /* Assume we need to rebuild the junkFilter */
     602       34042 :         fcache->junkFilter = NULL;
     603             :     }
     604             : 
     605             :     /*
     606             :      * We're beginning a new execution of the function, so convert params to
     607             :      * appropriate format.
     608             :      */
     609       85952 :     postquel_sub_params(fcache, fcinfo);
     610             : 
     611             :     /* Also reset lazyEval state for the new execution. */
     612       85952 :     fcache->lazyEvalOK = lazyEvalOK;
     613       85952 :     fcache->lazyEval = false;
     614             : 
     615             :     /* Also reset data about where we are in the function. */
     616       85952 :     fcache->eslist = NULL;
     617       85952 :     fcache->next_query_index = 0;
     618       85952 :     fcache->error_query_index = 0;
     619             : 
     620       85952 :     return fcache;
     621             : }
     622             : 
     623             : /*
     624             :  * Set up the per-query execution_state records for the next query within
     625             :  * the SQL function.
     626             :  *
     627             :  * Returns true if successful, false if there are no more queries.
     628             :  */
     629             : static bool
     630      164098 : init_execution_state(SQLFunctionCachePtr fcache)
     631             : {
     632             :     CachedPlanSource *plansource;
     633      164098 :     execution_state *preves = NULL;
     634      164098 :     execution_state *lasttages = NULL;
     635             :     int         nstmts;
     636             :     ListCell   *lc;
     637             : 
     638             :     /*
     639             :      * Clean up after previous query, if there was one.
     640             :      */
     641      164098 :     if (fcache->cplan)
     642             :     {
     643       78146 :         ReleaseCachedPlan(fcache->cplan, fcache->cowner);
     644       78146 :         fcache->cplan = NULL;
     645             :     }
     646      164098 :     fcache->eslist = NULL;
     647             : 
     648             :     /*
     649             :      * Get the next CachedPlanSource, or stop if there are no more.  We might
     650             :      * need to create the next CachedPlanSource; if so, advance
     651             :      * error_query_index first, so that errors detected in prepare_next_query
     652             :      * are blamed on the right statement.
     653             :      */
     654      164098 :     if (fcache->next_query_index >= list_length(fcache->func->plansource_list))
     655             :     {
     656       80258 :         if (fcache->next_query_index >= fcache->func->num_queries)
     657       78056 :             return false;
     658        2202 :         fcache->error_query_index++;
     659        2202 :         prepare_next_query(fcache->func);
     660             :     }
     661             :     else
     662       83840 :         fcache->error_query_index++;
     663             : 
     664       86036 :     plansource = (CachedPlanSource *) list_nth(fcache->func->plansource_list,
     665             :                                                fcache->next_query_index);
     666       86036 :     fcache->next_query_index++;
     667             : 
     668             :     /*
     669             :      * Generate plans for the query or queries within this CachedPlanSource.
     670             :      * Register the CachedPlan with the current resource owner.  (Saving
     671             :      * cowner here is mostly paranoia, but this way we needn't assume that
     672             :      * CurrentResourceOwner will be the same when ShutdownSQLFunction runs.)
     673             :      */
     674       86036 :     fcache->cowner = CurrentResourceOwner;
     675       86036 :     fcache->cplan = GetCachedPlan(plansource,
     676             :                                   fcache->paramLI,
     677             :                                   fcache->cowner,
     678             :                                   NULL);
     679             : 
     680             :     /*
     681             :      * If necessary, make esarray[] bigger to hold the needed state.
     682             :      */
     683       85986 :     nstmts = list_length(fcache->cplan->stmt_list);
     684       85986 :     if (nstmts > fcache->esarray_len)
     685             :     {
     686       33992 :         if (fcache->esarray == NULL)
     687       33992 :             fcache->esarray = (execution_state *)
     688       33992 :                 MemoryContextAlloc(fcache->fcontext,
     689             :                                    sizeof(execution_state) * nstmts);
     690             :         else
     691           0 :             fcache->esarray = repalloc_array(fcache->esarray,
     692             :                                              execution_state, nstmts);
     693       33992 :         fcache->esarray_len = nstmts;
     694             :     }
     695             : 
     696             :     /*
     697             :      * Build execution_state list to match the number of contained plans.
     698             :      */
     699      171978 :     foreach(lc, fcache->cplan->stmt_list)
     700             :     {
     701       85992 :         PlannedStmt *stmt = lfirst_node(PlannedStmt, lc);
     702             :         execution_state *newes;
     703             : 
     704             :         /*
     705             :          * Precheck all commands for validity in a function.  This should
     706             :          * generally match the restrictions spi.c applies.
     707             :          */
     708       85992 :         if (stmt->commandType == CMD_UTILITY)
     709             :         {
     710         180 :             if (IsA(stmt->utilityStmt, CopyStmt) &&
     711           0 :                 ((CopyStmt *) stmt->utilityStmt)->filename == NULL)
     712           0 :                 ereport(ERROR,
     713             :                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     714             :                          errmsg("cannot COPY to/from client in an SQL function")));
     715             : 
     716         180 :             if (IsA(stmt->utilityStmt, TransactionStmt))
     717           0 :                 ereport(ERROR,
     718             :                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     719             :                 /* translator: %s is a SQL statement name */
     720             :                          errmsg("%s is not allowed in an SQL function",
     721             :                                 CreateCommandName(stmt->utilityStmt))));
     722             :         }
     723             : 
     724       85992 :         if (fcache->func->readonly_func && !CommandIsReadOnly(stmt))
     725           0 :             ereport(ERROR,
     726             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     727             :             /* translator: %s is a SQL statement name */
     728             :                      errmsg("%s is not allowed in a non-volatile function",
     729             :                             CreateCommandName((Node *) stmt))));
     730             : 
     731             :         /* OK, build the execution_state for this query */
     732       85992 :         newes = &fcache->esarray[foreach_current_index(lc)];
     733       85992 :         if (preves)
     734           6 :             preves->next = newes;
     735             :         else
     736       85986 :             fcache->eslist = newes;
     737             : 
     738       85992 :         newes->next = NULL;
     739       85992 :         newes->status = F_EXEC_START;
     740       85992 :         newes->setsResult = false;   /* might change below */
     741       85992 :         newes->lazyEval = false; /* might change below */
     742       85992 :         newes->stmt = stmt;
     743       85992 :         newes->qd = NULL;
     744             : 
     745       85992 :         if (stmt->canSetTag)
     746       85986 :             lasttages = newes;
     747             : 
     748       85992 :         preves = newes;
     749             :     }
     750             : 
     751             :     /*
     752             :      * If this isn't the last CachedPlanSource, we're done here.  Otherwise,
     753             :      * we need to prepare information about how to return the results.
     754             :      */
     755       85986 :     if (fcache->next_query_index < fcache->func->num_queries)
     756         126 :         return true;
     757             : 
     758             :     /*
     759             :      * Construct a JunkFilter we can use to coerce the returned rowtype to the
     760             :      * desired form, unless the result type is VOID, in which case there's
     761             :      * nothing to coerce to.  (XXX Frequently, the JunkFilter isn't doing
     762             :      * anything very interesting, but much of this module expects it to be
     763             :      * there anyway.)
     764             :      *
     765             :      * Normally we can re-use the JunkFilter across executions, but if the
     766             :      * plan for the last CachedPlanSource changed, we'd better rebuild it.
     767             :      *
     768             :      * The JunkFilter, its result slot, and its tupledesc are kept in a
     769             :      * subsidiary memory context so that we can free them easily when needed.
     770             :      */
     771       85860 :     if (fcache->func->rettype != VOIDOID &&
     772       85566 :         (fcache->junkFilter == NULL ||
     773       51898 :          fcache->jf_generation != fcache->cplan->generation))
     774             :     {
     775             :         TupleTableSlot *slot;
     776             :         List       *resulttlist;
     777             :         MemoryContext oldcontext;
     778             : 
     779             :         /* Create or reset the jfcontext */
     780       35810 :         if (fcache->jfcontext == NULL)
     781       33668 :             fcache->jfcontext = AllocSetContextCreate(fcache->fcontext,
     782             :                                                       "SQL function junkfilter",
     783             :                                                       ALLOCSET_SMALL_SIZES);
     784             :         else
     785        2142 :             MemoryContextReset(fcache->jfcontext);
     786       35810 :         oldcontext = MemoryContextSwitchTo(fcache->jfcontext);
     787             : 
     788       35810 :         slot = MakeSingleTupleTableSlot(NULL, &TTSOpsMinimalTuple);
     789             : 
     790             :         /*
     791             :          * Re-fetch the (possibly modified) output tlist of the final
     792             :          * statement.  By this point, we should have thrown an error if there
     793             :          * is not one.
     794             :          */
     795       35810 :         resulttlist = get_sql_fn_result_tlist(plansource->query_list);
     796             : 
     797             :         /*
     798             :          * If the result is composite, *and* we are returning the whole tuple
     799             :          * result, we need to insert nulls for any dropped columns.  In the
     800             :          * single-column-result case, there might be dropped columns within
     801             :          * the composite column value, but it's not our problem here.  There
     802             :          * should be no resjunk entries in resulttlist, so in the second case
     803             :          * the JunkFilter is certainly a no-op.
     804             :          */
     805       35810 :         if (fcache->func->rettupdesc && fcache->func->returnsTuple)
     806        1604 :             fcache->junkFilter = ExecInitJunkFilterConversion(resulttlist,
     807        1604 :                                                               fcache->func->rettupdesc,
     808             :                                                               slot);
     809             :         else
     810       34206 :             fcache->junkFilter = ExecInitJunkFilter(resulttlist, slot);
     811             : 
     812             :         /*
     813             :          * The resulttlist tree belongs to the plancache and might disappear
     814             :          * underneath us due to plancache invalidation.  While we could
     815             :          * forestall that by copying it, that'd just be a waste of cycles,
     816             :          * because the junkfilter doesn't need it anymore.  (It'd only be used
     817             :          * by ExecFindJunkAttribute(), which we don't use here.)  To ensure
     818             :          * there's not a dangling pointer laying about, clear the junkFilter's
     819             :          * pointer.
     820             :          */
     821       35810 :         fcache->junkFilter->jf_targetList = NIL;
     822             : 
     823             :         /* Make sure output rowtype is properly blessed */
     824       35810 :         if (fcache->func->returnsTuple)
     825        1628 :             BlessTupleDesc(fcache->junkFilter->jf_resultSlot->tts_tupleDescriptor);
     826             : 
     827             :         /* Mark the JunkFilter as up-to-date */
     828       35810 :         fcache->jf_generation = fcache->cplan->generation;
     829             : 
     830       35810 :         MemoryContextSwitchTo(oldcontext);
     831             :     }
     832             : 
     833       85860 :     if (fcache->func->returnsSet &&
     834        4240 :         !fcache->func->returnsTuple &&
     835         194 :         type_is_rowtype(fcache->func->rettype))
     836             :     {
     837             :         /*
     838             :          * Returning rowtype as if it were scalar --- materialize won't work.
     839             :          * Right now it's sufficient to override any caller preference for
     840             :          * materialize mode, but this might need more work in future.
     841             :          */
     842           0 :         fcache->lazyEvalOK = true;
     843             :     }
     844             : 
     845             :     /*
     846             :      * Mark the last canSetTag query as delivering the function result; then,
     847             :      * if it is a plain SELECT, mark it for lazy evaluation. If it's not a
     848             :      * SELECT we must always run it to completion.
     849             :      *
     850             :      * Note: at some point we might add additional criteria for whether to use
     851             :      * lazy eval.  However, we should prefer to use it whenever the function
     852             :      * doesn't return set, since fetching more than one row is useless in that
     853             :      * case.
     854             :      *
     855             :      * Note: don't set setsResult if the function returns VOID, as evidenced
     856             :      * by not having made a junkfilter.  This ensures we'll throw away any
     857             :      * output from the last statement in such a function.
     858             :      */
     859       85860 :     if (lasttages && fcache->junkFilter)
     860             :     {
     861       85566 :         lasttages->setsResult = true;
     862       85566 :         if (fcache->lazyEvalOK &&
     863       84732 :             lasttages->stmt->commandType == CMD_SELECT &&
     864       84654 :             !lasttages->stmt->hasModifyingCTE)
     865       84654 :             fcache->lazyEval = lasttages->lazyEval = true;
     866             :     }
     867             : 
     868       85860 :     return true;
     869             : }
     870             : 
     871             : /*
     872             :  * Convert the SQL function's next query from source form (RawStmt or Query)
     873             :  * into a CachedPlanSource.  If it's the last query, also determine whether
     874             :  * the function returnsTuple.
     875             :  */
     876             : static void
     877        2202 : prepare_next_query(SQLFunctionHashEntry *func)
     878             : {
     879             :     int         qindex;
     880             :     bool        islast;
     881             :     CachedPlanSource *plansource;
     882             :     List       *queryTree_list;
     883             :     MemoryContext oldcontext;
     884             : 
     885             :     /* Which query should we process? */
     886        2202 :     qindex = list_length(func->plansource_list);
     887             :     Assert(qindex < func->num_queries); /* else caller error */
     888        2202 :     islast = (qindex + 1 >= func->num_queries);
     889             : 
     890             :     /*
     891             :      * Parse and/or rewrite the query, creating a CachedPlanSource that holds
     892             :      * a copy of the original parsetree.  Note fine point: we make a copy of
     893             :      * each original parsetree to ensure that the source_list in pcontext
     894             :      * remains unmodified during parse analysis and rewrite.  This is normally
     895             :      * unnecessary, but we have to do it in case an error is raised during
     896             :      * parse analysis.  Otherwise, a fresh attempt to execute the function
     897             :      * will arrive back here and try to work from a corrupted source_list.
     898             :      */
     899        2202 :     if (!func->raw_source)
     900             :     {
     901             :         /* Source queries are already parse-analyzed */
     902         886 :         Query      *parsetree = list_nth_node(Query, func->source_list, qindex);
     903             : 
     904         886 :         parsetree = copyObject(parsetree);
     905         886 :         plansource = CreateCachedPlanForQuery(parsetree,
     906         886 :                                               func->src,
     907             :                                               CreateCommandTag((Node *) parsetree));
     908         886 :         AcquireRewriteLocks(parsetree, true, false);
     909         886 :         queryTree_list = pg_rewrite_query(parsetree);
     910             :     }
     911             :     else
     912             :     {
     913             :         /* Source queries are raw parsetrees */
     914        1316 :         RawStmt    *parsetree = list_nth_node(RawStmt, func->source_list, qindex);
     915             : 
     916        1316 :         parsetree = copyObject(parsetree);
     917        1316 :         plansource = CreateCachedPlan(parsetree,
     918        1316 :                                       func->src,
     919             :                                       CreateCommandTag(parsetree->stmt));
     920        1316 :         queryTree_list = pg_analyze_and_rewrite_withcb(parsetree,
     921        1316 :                                                        func->src,
     922             :                                                        (ParserSetupHook) sql_fn_parser_setup,
     923        1316 :                                                        func->pinfo,
     924             :                                                        NULL);
     925             :     }
     926             : 
     927             :     /*
     928             :      * Check that there are no statements we don't want to allow.
     929             :      */
     930        2202 :     check_sql_fn_statement(queryTree_list);
     931             : 
     932             :     /*
     933             :      * If this is the last query, check that the function returns the type it
     934             :      * claims to.  Although in simple cases this was already done when the
     935             :      * function was defined, we have to recheck because database objects used
     936             :      * in the function's queries might have changed type.  We'd have to
     937             :      * recheck anyway if the function had any polymorphic arguments. Moreover,
     938             :      * check_sql_stmt_retval takes care of injecting any required column type
     939             :      * coercions.  (But we don't ask it to insert nulls for dropped columns;
     940             :      * the junkfilter handles that.)
     941             :      *
     942             :      * Note: we set func->returnsTuple according to whether we are returning
     943             :      * the whole tuple result or just a single column.  In the latter case we
     944             :      * clear returnsTuple because we need not act different from the scalar
     945             :      * result case, even if it's a rowtype column.  (However, we have to force
     946             :      * lazy eval mode in that case; otherwise we'd need extra code to expand
     947             :      * the rowtype column into multiple columns, since we have no way to
     948             :      * notify the caller that it should do that.)
     949             :      */
     950        2202 :     if (islast)
     951        2126 :         func->returnsTuple = check_sql_stmt_retval(queryTree_list,
     952             :                                                    func->rettype,
     953             :                                                    func->rettupdesc,
     954        2132 :                                                    func->prokind,
     955             :                                                    false);
     956             : 
     957             :     /*
     958             :      * Now that check_sql_stmt_retval has done its thing, we can complete plan
     959             :      * cache entry creation.
     960             :      */
     961        2196 :     CompleteCachedPlan(plansource,
     962             :                        queryTree_list,
     963             :                        NULL,
     964             :                        NULL,
     965             :                        0,
     966             :                        (ParserSetupHook) sql_fn_parser_setup,
     967        2196 :                        func->pinfo,
     968             :                        CURSOR_OPT_PARALLEL_OK | CURSOR_OPT_NO_SCROLL,
     969             :                        false);
     970             : 
     971             :     /*
     972             :      * Install post-rewrite hook.  Its arg is the hash entry if this is the
     973             :      * last statement, else NULL.
     974             :      */
     975        2196 :     SetPostRewriteHook(plansource,
     976             :                        sql_postrewrite_callback,
     977             :                        islast ? func : NULL);
     978             : 
     979             :     /*
     980             :      * While the CachedPlanSources can take care of themselves, our List
     981             :      * pointing to them had better be in the hcontext.
     982             :      */
     983        2196 :     oldcontext = MemoryContextSwitchTo(func->hcontext);
     984        2196 :     func->plansource_list = lappend(func->plansource_list, plansource);
     985        2196 :     MemoryContextSwitchTo(oldcontext);
     986             : 
     987             :     /*
     988             :      * As soon as we've linked the CachedPlanSource into the list, mark it as
     989             :      * "saved".
     990             :      */
     991        2196 :     SaveCachedPlan(plansource);
     992             : 
     993             :     /*
     994             :      * Finally, if this was the last statement, we can flush the pcontext with
     995             :      * the original query trees; they're all safely copied into
     996             :      * CachedPlanSources now.
     997             :      */
     998        2196 :     if (islast)
     999             :     {
    1000        2126 :         func->source_list = NIL; /* avoid dangling pointer */
    1001        2126 :         MemoryContextDelete(func->pcontext);
    1002        2126 :         func->pcontext = NULL;
    1003             :     }
    1004        2196 : }
    1005             : 
    1006             : /*
    1007             :  * Fill a new SQLFunctionHashEntry.
    1008             :  *
    1009             :  * The passed-in "cfunc" struct is expected to be zeroes, except
    1010             :  * for the CachedFunction fields, which we don't touch here.
    1011             :  *
    1012             :  * We expect to be called in a short-lived memory context (typically a
    1013             :  * query's per-tuple context).  Data that is to be part of the hash entry
    1014             :  * must be copied into the hcontext or pcontext as appropriate.
    1015             :  */
    1016             : static void
    1017        2168 : sql_compile_callback(FunctionCallInfo fcinfo,
    1018             :                      HeapTuple procedureTuple,
    1019             :                      const CachedFunctionHashKey *hashkey,
    1020             :                      CachedFunction *cfunc,
    1021             :                      bool forValidator)
    1022             : {
    1023        2168 :     SQLFunctionHashEntry *func = (SQLFunctionHashEntry *) cfunc;
    1024        2168 :     Form_pg_proc procedureStruct = (Form_pg_proc) GETSTRUCT(procedureTuple);
    1025             :     ErrorContextCallback comperrcontext;
    1026             :     MemoryContext hcontext;
    1027             :     MemoryContext pcontext;
    1028        2168 :     MemoryContext oldcontext = CurrentMemoryContext;
    1029             :     Oid         rettype;
    1030             :     TupleDesc   rettupdesc;
    1031             :     Datum       tmp;
    1032             :     bool        isNull;
    1033             :     List       *source_list;
    1034             : 
    1035             :     /*
    1036             :      * Setup error traceback support for ereport() during compile.  (This is
    1037             :      * mainly useful for reporting parse errors from pg_parse_query.)
    1038             :      */
    1039        2168 :     comperrcontext.callback = sql_compile_error_callback;
    1040        2168 :     comperrcontext.arg = func;
    1041        2168 :     comperrcontext.previous = error_context_stack;
    1042        2168 :     error_context_stack = &comperrcontext;
    1043             : 
    1044             :     /*
    1045             :      * Create the hash entry's memory context.  For now it's a child of the
    1046             :      * caller's context, so that it will go away if we fail partway through.
    1047             :      */
    1048        2168 :     hcontext = AllocSetContextCreate(CurrentMemoryContext,
    1049             :                                      "SQL function",
    1050             :                                      ALLOCSET_SMALL_SIZES);
    1051             : 
    1052             :     /*
    1053             :      * Create the not-as-long-lived pcontext.  We make this a child of
    1054             :      * hcontext so that it doesn't require separate deletion.
    1055             :      */
    1056        2168 :     pcontext = AllocSetContextCreate(hcontext,
    1057             :                                      "SQL function parse trees",
    1058             :                                      ALLOCSET_SMALL_SIZES);
    1059        2168 :     func->pcontext = pcontext;
    1060             : 
    1061             :     /*
    1062             :      * copy function name immediately for use by error reporting callback, and
    1063             :      * for use as memory context identifier
    1064             :      */
    1065        4336 :     func->fname = MemoryContextStrdup(hcontext,
    1066        2168 :                                       NameStr(procedureStruct->proname));
    1067        2168 :     MemoryContextSetIdentifier(hcontext, func->fname);
    1068             : 
    1069             :     /*
    1070             :      * Resolve any polymorphism, obtaining the actual result type, and the
    1071             :      * corresponding tupdesc if it's a rowtype.
    1072             :      */
    1073        2168 :     (void) get_call_result_type(fcinfo, &rettype, &rettupdesc);
    1074             : 
    1075        2168 :     func->rettype = rettype;
    1076        2168 :     if (rettupdesc)
    1077             :     {
    1078         530 :         MemoryContextSwitchTo(hcontext);
    1079         530 :         func->rettupdesc = CreateTupleDescCopy(rettupdesc);
    1080         530 :         MemoryContextSwitchTo(oldcontext);
    1081             :     }
    1082             : 
    1083             :     /* Fetch the typlen and byval info for the result type */
    1084        2168 :     get_typlenbyval(rettype, &func->typlen, &func->typbyval);
    1085             : 
    1086             :     /* Remember whether we're returning setof something */
    1087        2168 :     func->returnsSet = procedureStruct->proretset;
    1088             : 
    1089             :     /* Remember if function is STABLE/IMMUTABLE */
    1090        2168 :     func->readonly_func =
    1091        2168 :         (procedureStruct->provolatile != PROVOLATILE_VOLATILE);
    1092             : 
    1093             :     /* Remember routine kind */
    1094        2168 :     func->prokind = procedureStruct->prokind;
    1095             : 
    1096             :     /*
    1097             :      * We need the actual argument types to pass to the parser.  Also make
    1098             :      * sure that parameter symbols are considered to have the function's
    1099             :      * resolved input collation.
    1100             :      */
    1101        2168 :     MemoryContextSwitchTo(hcontext);
    1102        4336 :     func->pinfo = prepare_sql_fn_parse_info(procedureTuple,
    1103        2168 :                                             fcinfo->flinfo->fn_expr,
    1104             :                                             PG_GET_COLLATION());
    1105        2168 :     MemoryContextSwitchTo(oldcontext);
    1106             : 
    1107             :     /*
    1108             :      * Now that we have the resolved argument types, collect their typlens for
    1109             :      * use in postquel_sub_params.
    1110             :      */
    1111        2168 :     func->argtyplen = (int16 *)
    1112        2168 :         MemoryContextAlloc(hcontext, func->pinfo->nargs * sizeof(int16));
    1113        5296 :     for (int i = 0; i < func->pinfo->nargs; i++)
    1114        3128 :         func->argtyplen[i] = get_typlen(func->pinfo->argtypes[i]);
    1115             : 
    1116             :     /*
    1117             :      * And of course we need the function body text.
    1118             :      */
    1119        2168 :     tmp = SysCacheGetAttrNotNull(PROCOID, procedureTuple, Anum_pg_proc_prosrc);
    1120        2168 :     func->src = MemoryContextStrdup(hcontext,
    1121        2168 :                                     TextDatumGetCString(tmp));
    1122             : 
    1123             :     /* If we have prosqlbody, pay attention to that not prosrc. */
    1124        2168 :     tmp = SysCacheGetAttr(PROCOID,
    1125             :                           procedureTuple,
    1126             :                           Anum_pg_proc_prosqlbody,
    1127             :                           &isNull);
    1128        2168 :     if (!isNull)
    1129             :     {
    1130             :         /* Source queries are already parse-analyzed */
    1131             :         Node       *n;
    1132             : 
    1133         886 :         n = stringToNode(TextDatumGetCString(tmp));
    1134         886 :         if (IsA(n, List))
    1135         656 :             source_list = linitial_node(List, castNode(List, n));
    1136             :         else
    1137         230 :             source_list = list_make1(n);
    1138         886 :         func->raw_source = false;
    1139             :     }
    1140             :     else
    1141             :     {
    1142             :         /* Source queries are raw parsetrees */
    1143        1282 :         source_list = pg_parse_query(func->src);
    1144        1282 :         func->raw_source = true;
    1145             :     }
    1146             : 
    1147             :     /*
    1148             :      * Note: we must save the number of queries so that we'll still remember
    1149             :      * how many there are after we discard source_list.
    1150             :      */
    1151        2168 :     func->num_queries = list_length(source_list);
    1152             : 
    1153             :     /*
    1154             :      * Edge case: empty function body is OK only if it returns VOID.  Normally
    1155             :      * we validate that the last statement returns the right thing in
    1156             :      * check_sql_stmt_retval, but we'll never reach that if there's no last
    1157             :      * statement.
    1158             :      */
    1159        2168 :     if (func->num_queries == 0 && rettype != VOIDOID)
    1160           6 :         ereport(ERROR,
    1161             :                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    1162             :                  errmsg("return type mismatch in function declared to return %s",
    1163             :                         format_type_be(rettype)),
    1164             :                  errdetail("Function's final statement must be SELECT or INSERT/UPDATE/DELETE/MERGE RETURNING.")));
    1165             : 
    1166             :     /* Save the source trees in pcontext for now. */
    1167        2162 :     MemoryContextSwitchTo(pcontext);
    1168        2162 :     func->source_list = copyObject(source_list);
    1169        2162 :     MemoryContextSwitchTo(oldcontext);
    1170             : 
    1171             :     /*
    1172             :      * We now have a fully valid hash entry, so reparent hcontext under
    1173             :      * CacheMemoryContext to make all the subsidiary data long-lived, and only
    1174             :      * then install the hcontext link so that sql_delete_callback will know to
    1175             :      * delete it.
    1176             :      */
    1177        2162 :     MemoryContextSetParent(hcontext, CacheMemoryContext);
    1178        2162 :     func->hcontext = hcontext;
    1179             : 
    1180        2162 :     error_context_stack = comperrcontext.previous;
    1181        2162 : }
    1182             : 
    1183             : /*
    1184             :  * Deletion callback used by funccache.c.
    1185             :  *
    1186             :  * Free any free-able subsidiary data of cfunc, but not the
    1187             :  * struct CachedFunction itself.
    1188             :  */
    1189             : static void
    1190          66 : sql_delete_callback(CachedFunction *cfunc)
    1191             : {
    1192          66 :     SQLFunctionHashEntry *func = (SQLFunctionHashEntry *) cfunc;
    1193             :     ListCell   *lc;
    1194             : 
    1195             :     /* Release the CachedPlanSources */
    1196         132 :     foreach(lc, func->plansource_list)
    1197             :     {
    1198          66 :         CachedPlanSource *plansource = (CachedPlanSource *) lfirst(lc);
    1199             : 
    1200          66 :         DropCachedPlan(plansource);
    1201             :     }
    1202          66 :     func->plansource_list = NIL;
    1203             : 
    1204             :     /*
    1205             :      * If we have an hcontext, free it, thereby getting rid of all subsidiary
    1206             :      * data.  (If we still have a pcontext, this gets rid of that too.)
    1207             :      */
    1208          66 :     if (func->hcontext)
    1209          66 :         MemoryContextDelete(func->hcontext);
    1210          66 :     func->hcontext = NULL;
    1211          66 : }
    1212             : 
    1213             : /*
    1214             :  * Post-rewrite callback used by plancache.c.
    1215             :  *
    1216             :  * This must match the processing that prepare_next_query() does between
    1217             :  * rewriting and calling CompleteCachedPlan().
    1218             :  */
    1219             : static void
    1220         346 : sql_postrewrite_callback(List *querytree_list, void *arg)
    1221             : {
    1222             :     /*
    1223             :      * Check that there are no statements we don't want to allow.  (Presently,
    1224             :      * there's no real point in this because the result can't change from what
    1225             :      * we saw originally.  But it's cheap and maybe someday it will matter.)
    1226             :      */
    1227         346 :     check_sql_fn_statement(querytree_list);
    1228             : 
    1229             :     /*
    1230             :      * If this is the last query, we must re-do what check_sql_stmt_retval did
    1231             :      * to its targetlist.  Also check that returnsTuple didn't change (it
    1232             :      * probably cannot, but be cautious).
    1233             :      */
    1234         346 :     if (arg != NULL)
    1235             :     {
    1236         346 :         SQLFunctionHashEntry *func = (SQLFunctionHashEntry *) arg;
    1237             :         bool        returnsTuple;
    1238             : 
    1239         346 :         returnsTuple = check_sql_stmt_retval(querytree_list,
    1240             :                                              func->rettype,
    1241             :                                              func->rettupdesc,
    1242         346 :                                              func->prokind,
    1243             :                                              false);
    1244         346 :         if (returnsTuple != func->returnsTuple)
    1245           0 :             ereport(ERROR,
    1246             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1247             :                      errmsg("cached plan must not change result type")));
    1248             :     }
    1249         346 : }
    1250             : 
    1251             : /* Start up execution of one execution_state node */
    1252             : static void
    1253       85992 : postquel_start(execution_state *es, SQLFunctionCachePtr fcache)
    1254             : {
    1255             :     DestReceiver *dest;
    1256       85992 :     MemoryContext oldcontext = CurrentMemoryContext;
    1257             : 
    1258             :     Assert(es->qd == NULL);
    1259             : 
    1260             :     /* Caller should have ensured a suitable snapshot is active */
    1261             :     Assert(ActiveSnapshotSet());
    1262             : 
    1263             :     /*
    1264             :      * In lazyEval mode for a SRF, we must run the sub-executor in a child of
    1265             :      * fcontext, so that it can survive across multiple calls to fmgr_sql.
    1266             :      * (XXX in the case of a long-lived FmgrInfo, this policy potentially
    1267             :      * causes memory leakage, but it's not very clear where we could keep
    1268             :      * stuff instead.  Fortunately, there are few if any cases where
    1269             :      * set-returning functions are invoked via FmgrInfos that would outlive
    1270             :      * the calling query.)  Otherwise, we're going to run it to completion
    1271             :      * before exiting fmgr_sql, so it can perfectly well run in the caller's
    1272             :      * context.
    1273             :      */
    1274       85992 :     if (es->lazyEval && fcache->func->returnsSet)
    1275             :     {
    1276        3176 :         fcache->subcontext = AllocSetContextCreate(fcache->fcontext,
    1277             :                                                    "SQL function execution",
    1278             :                                                    ALLOCSET_DEFAULT_SIZES);
    1279        3176 :         fcache->ownSubcontext = true;
    1280             :     }
    1281       82816 :     else if (es->stmt->commandType == CMD_UTILITY)
    1282             :     {
    1283             :         /*
    1284             :          * The code path using a sub-executor is pretty good about cleaning up
    1285             :          * cruft, since the executor will make its own sub-context.  We don't
    1286             :          * really need an additional layer of sub-context in that case.
    1287             :          * However, if this is a utility statement, it won't make its own
    1288             :          * sub-context, so it seems advisable to make one that we can free on
    1289             :          * completion.
    1290             :          */
    1291         180 :         fcache->subcontext = AllocSetContextCreate(CurrentMemoryContext,
    1292             :                                                    "SQL function execution",
    1293             :                                                    ALLOCSET_DEFAULT_SIZES);
    1294         180 :         fcache->ownSubcontext = true;
    1295             :     }
    1296             :     else
    1297             :     {
    1298       82636 :         fcache->subcontext = CurrentMemoryContext;
    1299       82636 :         fcache->ownSubcontext = false;
    1300             :     }
    1301             : 
    1302             :     /*
    1303             :      * Build a tuplestore if needed, that is if it's a set-returning function
    1304             :      * and we're producing the function result without using lazyEval mode.
    1305             :      */
    1306       85992 :     if (es->setsResult)
    1307             :     {
    1308             :         Assert(fcache->tstore == NULL);
    1309       85566 :         if (fcache->func->returnsSet && !es->lazyEval)
    1310             :         {
    1311         864 :             MemoryContextSwitchTo(fcache->tscontext);
    1312         864 :             fcache->tstore = tuplestore_begin_heap(fcache->randomAccess,
    1313             :                                                    false, work_mem);
    1314             :         }
    1315             :     }
    1316             : 
    1317             :     /* Switch into the selected subcontext (might be a no-op) */
    1318       85992 :     MemoryContextSwitchTo(fcache->subcontext);
    1319             : 
    1320             :     /*
    1321             :      * If this query produces the function result, collect its output using
    1322             :      * our custom DestReceiver; else discard any output.
    1323             :      */
    1324       85992 :     if (es->setsResult)
    1325             :     {
    1326             :         DR_sqlfunction *myState;
    1327             : 
    1328       85566 :         dest = CreateDestReceiver(DestSQLFunction);
    1329             :         /* pass down the needed info to the dest receiver routines */
    1330       85566 :         myState = (DR_sqlfunction *) dest;
    1331             :         Assert(myState->pub.mydest == DestSQLFunction);
    1332       85566 :         myState->tstore = fcache->tstore; /* might be NULL */
    1333       85566 :         myState->filter = fcache->junkFilter;
    1334             : 
    1335             :         /* Make very sure the junkfilter's result slot is empty */
    1336       85566 :         ExecClearTuple(fcache->junkFilter->jf_resultSlot);
    1337             :     }
    1338             :     else
    1339         426 :         dest = None_Receiver;
    1340             : 
    1341       85992 :     es->qd = CreateQueryDesc(es->stmt,
    1342       85992 :                              fcache->func->src,
    1343             :                              GetActiveSnapshot(),
    1344             :                              InvalidSnapshot,
    1345             :                              dest,
    1346             :                              fcache->paramLI,
    1347       85992 :                              es->qd ? es->qd->queryEnv : NULL,
    1348             :                              0);
    1349             : 
    1350             :     /* Utility commands don't need Executor. */
    1351       85992 :     if (es->qd->operation != CMD_UTILITY)
    1352             :     {
    1353             :         /*
    1354             :          * In lazyEval mode, do not let the executor set up an AfterTrigger
    1355             :          * context.  This is necessary not just an optimization, because we
    1356             :          * mustn't exit from the function execution with a stacked
    1357             :          * AfterTrigger level still active.  We are careful not to select
    1358             :          * lazyEval mode for any statement that could possibly queue triggers.
    1359             :          */
    1360             :         int         eflags;
    1361             : 
    1362       85812 :         if (es->lazyEval)
    1363       84654 :             eflags = EXEC_FLAG_SKIP_TRIGGERS;
    1364             :         else
    1365        1158 :             eflags = 0;         /* default run-to-completion flags */
    1366       85812 :         ExecutorStart(es->qd, eflags);
    1367             :     }
    1368             : 
    1369       85986 :     es->status = F_EXEC_RUN;
    1370             : 
    1371       85986 :     MemoryContextSwitchTo(oldcontext);
    1372       85986 : }
    1373             : 
    1374             : /* Run one execution_state; either to completion or to first result row */
    1375             : /* Returns true if we ran to completion */
    1376             : static bool
    1377       86974 : postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache)
    1378             : {
    1379             :     bool        result;
    1380             :     MemoryContext oldcontext;
    1381             : 
    1382             :     /* Run the sub-executor in subcontext */
    1383       86974 :     oldcontext = MemoryContextSwitchTo(fcache->subcontext);
    1384             : 
    1385       86974 :     if (es->qd->operation == CMD_UTILITY)
    1386             :     {
    1387         180 :         ProcessUtility(es->qd->plannedstmt,
    1388         180 :                        fcache->func->src,
    1389             :                        true,    /* protect function cache's parsetree */
    1390             :                        PROCESS_UTILITY_QUERY,
    1391         180 :                        es->qd->params,
    1392         180 :                        es->qd->queryEnv,
    1393         180 :                        es->qd->dest,
    1394             :                        NULL);
    1395          90 :         result = true;          /* never stops early */
    1396             :     }
    1397             :     else
    1398             :     {
    1399             :         /* Run regular commands to completion unless lazyEval */
    1400       86794 :         uint64      count = (es->lazyEval) ? 1 : 0;
    1401             : 
    1402       86794 :         ExecutorRun(es->qd, ForwardScanDirection, count);
    1403             : 
    1404             :         /*
    1405             :          * If we requested run to completion OR there was no tuple returned,
    1406             :          * command must be complete.
    1407             :          */
    1408       79074 :         result = (count == 0 || es->qd->estate->es_processed == 0);
    1409             :     }
    1410             : 
    1411       79164 :     MemoryContextSwitchTo(oldcontext);
    1412             : 
    1413       79164 :     return result;
    1414             : }
    1415             : 
    1416             : /* Shut down execution of one execution_state node */
    1417             : static void
    1418       78176 : postquel_end(execution_state *es, SQLFunctionCachePtr fcache)
    1419             : {
    1420             :     MemoryContext oldcontext;
    1421             : 
    1422             :     /* Run the sub-executor in subcontext */
    1423       78176 :     oldcontext = MemoryContextSwitchTo(fcache->subcontext);
    1424             : 
    1425             :     /* mark status done to ensure we don't do ExecutorEnd twice */
    1426       78176 :     es->status = F_EXEC_DONE;
    1427             : 
    1428             :     /* Utility commands don't need Executor. */
    1429       78176 :     if (es->qd->operation != CMD_UTILITY)
    1430             :     {
    1431       78086 :         ExecutorFinish(es->qd);
    1432       78068 :         ExecutorEnd(es->qd);
    1433             :     }
    1434             : 
    1435       78158 :     es->qd->dest->rDestroy(es->qd->dest);
    1436             : 
    1437       78158 :     FreeQueryDesc(es->qd);
    1438       78158 :     es->qd = NULL;
    1439             : 
    1440       78158 :     MemoryContextSwitchTo(oldcontext);
    1441             : 
    1442             :     /* Delete the subcontext, if it's actually a separate context */
    1443       78158 :     if (fcache->ownSubcontext)
    1444        3266 :         MemoryContextDelete(fcache->subcontext);
    1445       78158 :     fcache->subcontext = NULL;
    1446       78158 : }
    1447             : 
    1448             : /* Build ParamListInfo array representing current arguments */
    1449             : static void
    1450       85952 : postquel_sub_params(SQLFunctionCachePtr fcache,
    1451             :                     FunctionCallInfo fcinfo)
    1452             : {
    1453       85952 :     int         nargs = fcinfo->nargs;
    1454             : 
    1455       85952 :     if (nargs > 0)
    1456             :     {
    1457             :         ParamListInfo paramLI;
    1458       77394 :         Oid        *argtypes = fcache->func->pinfo->argtypes;
    1459       77394 :         int16      *argtyplen = fcache->func->argtyplen;
    1460             : 
    1461       77394 :         if (fcache->paramLI == NULL)
    1462             :         {
    1463             :             /* First time through: build a persistent ParamListInfo struct */
    1464             :             MemoryContext oldcontext;
    1465             : 
    1466       25520 :             oldcontext = MemoryContextSwitchTo(fcache->fcontext);
    1467       25520 :             paramLI = makeParamList(nargs);
    1468       25520 :             fcache->paramLI = paramLI;
    1469       25520 :             MemoryContextSwitchTo(oldcontext);
    1470             :         }
    1471             :         else
    1472             :         {
    1473       51874 :             paramLI = fcache->paramLI;
    1474             :             Assert(paramLI->numParams == nargs);
    1475             :         }
    1476             : 
    1477      228072 :         for (int i = 0; i < nargs; i++)
    1478             :         {
    1479      150678 :             ParamExternData *prm = &paramLI->params[i];
    1480             : 
    1481             :             /*
    1482             :              * If an incoming parameter value is a R/W expanded datum, we
    1483             :              * force it to R/O.  We'd be perfectly entitled to scribble on it,
    1484             :              * but the problem is that if the parameter is referenced more
    1485             :              * than once in the function, earlier references might mutate the
    1486             :              * value seen by later references, which won't do at all.  We
    1487             :              * could do better if we could be sure of the number of Param
    1488             :              * nodes in the function's plans; but we might not have planned
    1489             :              * all the statements yet, nor do we have plan tree walker
    1490             :              * infrastructure.  (Examining the parse trees is not good enough,
    1491             :              * because of possible function inlining during planning.)
    1492             :              */
    1493      150678 :             prm->isnull = fcinfo->args[i].isnull;
    1494      150678 :             prm->value = MakeExpandedObjectReadOnly(fcinfo->args[i].value,
    1495             :                                                     prm->isnull,
    1496             :                                                     argtyplen[i]);
    1497             :             /* Allow the value to be substituted into custom plans */
    1498      150678 :             prm->pflags = PARAM_FLAG_CONST;
    1499      150678 :             prm->ptype = argtypes[i];
    1500             :         }
    1501             :     }
    1502             :     else
    1503        8558 :         fcache->paramLI = NULL;
    1504       85952 : }
    1505             : 
    1506             : /*
    1507             :  * Extract the SQL function's value from a single result row.  This is used
    1508             :  * both for scalar (non-set) functions and for each row of a lazy-eval set
    1509             :  * result.  We expect the current memory context to be that of the caller
    1510             :  * of fmgr_sql.
    1511             :  */
    1512             : static Datum
    1513       69968 : postquel_get_single_result(TupleTableSlot *slot,
    1514             :                            FunctionCallInfo fcinfo,
    1515             :                            SQLFunctionCachePtr fcache)
    1516             : {
    1517             :     Datum       value;
    1518             : 
    1519             :     /*
    1520             :      * Set up to return the function value.  For pass-by-reference datatypes,
    1521             :      * be sure to copy the result into the current context.  We can't leave
    1522             :      * the data in the TupleTableSlot because we must clear the slot before
    1523             :      * returning.
    1524             :      */
    1525       69968 :     if (fcache->func->returnsTuple)
    1526             :     {
    1527             :         /* We must return the whole tuple as a Datum. */
    1528        1470 :         fcinfo->isnull = false;
    1529        1470 :         value = ExecFetchSlotHeapTupleDatum(slot);
    1530             :     }
    1531             :     else
    1532             :     {
    1533             :         /*
    1534             :          * Returning a scalar, which we have to extract from the first column
    1535             :          * of the SELECT result, and then copy into current context if needed.
    1536             :          */
    1537       68498 :         value = slot_getattr(slot, 1, &(fcinfo->isnull));
    1538             : 
    1539       68498 :         if (!fcinfo->isnull)
    1540       68104 :             value = datumCopy(value, fcache->func->typbyval, fcache->func->typlen);
    1541             :     }
    1542             : 
    1543             :     /* Clear the slot for next time */
    1544       69968 :     ExecClearTuple(slot);
    1545             : 
    1546       69968 :     return value;
    1547             : }
    1548             : 
    1549             : /*
    1550             :  * fmgr_sql: function call manager for SQL functions
    1551             :  */
    1552             : Datum
    1553       86946 : fmgr_sql(PG_FUNCTION_ARGS)
    1554             : {
    1555             :     SQLFunctionCachePtr fcache;
    1556             :     ErrorContextCallback sqlerrcontext;
    1557             :     MemoryContext tscontext;
    1558             :     bool        randomAccess;
    1559             :     bool        lazyEvalOK;
    1560             :     bool        pushed_snapshot;
    1561             :     execution_state *es;
    1562             :     TupleTableSlot *slot;
    1563             :     Datum       result;
    1564             : 
    1565             :     /* Check call context */
    1566       86946 :     if (fcinfo->flinfo->fn_retset)
    1567             :     {
    1568        5040 :         ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
    1569             : 
    1570             :         /*
    1571             :          * For simplicity, we require callers to support both set eval modes.
    1572             :          * There are cases where we must use one or must use the other, and
    1573             :          * it's not really worthwhile to postpone the check till we know. But
    1574             :          * note we do not require caller to provide an expectedDesc.
    1575             :          */
    1576        5040 :         if (!rsi || !IsA(rsi, ReturnSetInfo) ||
    1577        5040 :             (rsi->allowedModes & SFRM_ValuePerCall) == 0 ||
    1578        5040 :             (rsi->allowedModes & SFRM_Materialize) == 0)
    1579           0 :             ereport(ERROR,
    1580             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1581             :                      errmsg("set-valued function called in context that cannot accept a set")));
    1582        5040 :         randomAccess = rsi->allowedModes & SFRM_Materialize_Random;
    1583        5040 :         lazyEvalOK = !(rsi->allowedModes & SFRM_Materialize_Preferred);
    1584             :         /* tuplestore, if used, must have query lifespan */
    1585        5040 :         tscontext = rsi->econtext->ecxt_per_query_memory;
    1586             :     }
    1587             :     else
    1588             :     {
    1589       81906 :         randomAccess = false;
    1590       81906 :         lazyEvalOK = true;
    1591             :         /* we won't need a tuplestore */
    1592       81906 :         tscontext = NULL;
    1593             :     }
    1594             : 
    1595             :     /*
    1596             :      * Initialize fcache if starting a fresh execution.
    1597             :      */
    1598       86946 :     fcache = init_sql_fcache(fcinfo, lazyEvalOK);
    1599             : 
    1600             :     /* Remember info that we might need later to construct tuplestore */
    1601       86940 :     fcache->tscontext = tscontext;
    1602       86940 :     fcache->randomAccess = randomAccess;
    1603             : 
    1604             :     /*
    1605             :      * Now we can set up error traceback support for ereport()
    1606             :      */
    1607       86940 :     sqlerrcontext.callback = sql_exec_error_callback;
    1608       86940 :     sqlerrcontext.arg = fcache;
    1609       86940 :     sqlerrcontext.previous = error_context_stack;
    1610       86940 :     error_context_stack = &sqlerrcontext;
    1611             : 
    1612             :     /*
    1613             :      * Find first unfinished execution_state.  If none, advance to the next
    1614             :      * query in function.
    1615             :      */
    1616             :     do
    1617             :     {
    1618      172830 :         es = fcache->eslist;
    1619      172830 :         while (es && es->status == F_EXEC_DONE)
    1620           0 :             es = es->next;
    1621      172830 :         if (es)
    1622       86878 :             break;
    1623       85952 :     } while (init_execution_state(fcache));
    1624             : 
    1625             :     /*
    1626             :      * Execute each command in the function one after another until we either
    1627             :      * run out of commands or get a result row from a lazily-evaluated SELECT.
    1628             :      *
    1629             :      * Notes about snapshot management:
    1630             :      *
    1631             :      * In a read-only function, we just use the surrounding query's snapshot.
    1632             :      *
    1633             :      * In a non-read-only function, we rely on the fact that we'll never
    1634             :      * suspend execution between queries of the function: the only reason to
    1635             :      * suspend execution before completion is if we are returning a row from a
    1636             :      * lazily-evaluated SELECT.  So, when first entering this loop, we'll
    1637             :      * either start a new query (and push a fresh snapshot) or re-establish
    1638             :      * the active snapshot from the existing query descriptor.  If we need to
    1639             :      * start a new query in a subsequent execution of the loop, either we need
    1640             :      * a fresh snapshot (and pushed_snapshot is false) or the existing
    1641             :      * snapshot is on the active stack and we can just bump its command ID.
    1642             :      */
    1643       86884 :     pushed_snapshot = false;
    1644      165036 :     while (es)
    1645             :     {
    1646             :         bool        completed;
    1647             : 
    1648       86980 :         if (es->status == F_EXEC_START)
    1649             :         {
    1650             :             /*
    1651             :              * If not read-only, be sure to advance the command counter for
    1652             :              * each command, so that all work to date in this transaction is
    1653             :              * visible.  Take a new snapshot if we don't have one yet,
    1654             :              * otherwise just bump the command ID in the existing snapshot.
    1655             :              */
    1656       85992 :             if (!fcache->func->readonly_func)
    1657             :             {
    1658       73338 :                 CommandCounterIncrement();
    1659       73338 :                 if (!pushed_snapshot)
    1660             :                 {
    1661       73332 :                     PushActiveSnapshot(GetTransactionSnapshot());
    1662       73332 :                     pushed_snapshot = true;
    1663             :                 }
    1664             :                 else
    1665           6 :                     UpdateActiveSnapshotCommandId();
    1666             :             }
    1667             : 
    1668       85992 :             postquel_start(es, fcache);
    1669             :         }
    1670         988 :         else if (!fcache->func->readonly_func && !pushed_snapshot)
    1671             :         {
    1672             :             /* Re-establish active snapshot when re-entering function */
    1673         640 :             PushActiveSnapshot(es->qd->snapshot);
    1674         640 :             pushed_snapshot = true;
    1675             :         }
    1676             : 
    1677       86974 :         completed = postquel_getnext(es, fcache);
    1678             : 
    1679             :         /*
    1680             :          * If we ran the command to completion, we can shut it down now. Any
    1681             :          * row(s) we need to return are safely stashed in the result slot or
    1682             :          * tuplestore, and we want to be sure that, for example, AFTER
    1683             :          * triggers get fired before we return anything.  Also, if the
    1684             :          * function doesn't return set, we can shut it down anyway because it
    1685             :          * must be a SELECT and we don't care about fetching any more result
    1686             :          * rows.
    1687             :          */
    1688       79164 :         if (completed || !fcache->func->returnsSet)
    1689       78170 :             postquel_end(es, fcache);
    1690             : 
    1691             :         /*
    1692             :          * Break from loop if we didn't shut down (implying we got a
    1693             :          * lazily-evaluated row).  Otherwise we'll press on till the whole
    1694             :          * function is done, relying on the tuplestore to keep hold of the
    1695             :          * data to eventually be returned.  This is necessary since an
    1696             :          * INSERT/UPDATE/DELETE RETURNING that sets the result might be
    1697             :          * followed by additional rule-inserted commands, and we want to
    1698             :          * finish doing all those commands before we return anything.
    1699             :          */
    1700       79146 :         if (es->status != F_EXEC_DONE)
    1701         994 :             break;
    1702             : 
    1703             :         /*
    1704             :          * Advance to next execution_state, and perhaps next query.
    1705             :          */
    1706       78152 :         es = es->next;
    1707       78248 :         while (!es)
    1708             :         {
    1709             :             /*
    1710             :              * Flush the current snapshot so that we will take a new one for
    1711             :              * the new query list.  This ensures that new snaps are taken at
    1712             :              * original-query boundaries, matching the behavior of interactive
    1713             :              * execution.
    1714             :              */
    1715       78146 :             if (pushed_snapshot)
    1716             :             {
    1717       65530 :                 PopActiveSnapshot();
    1718       65530 :                 pushed_snapshot = false;
    1719             :             }
    1720             : 
    1721       78146 :             if (!init_execution_state(fcache))
    1722       78050 :                 break;          /* end of function */
    1723             : 
    1724          96 :             es = fcache->eslist;
    1725             :         }
    1726             :     }
    1727             : 
    1728             :     /*
    1729             :      * The result slot or tuplestore now contains whatever row(s) we are
    1730             :      * supposed to return.
    1731             :      */
    1732       79050 :     if (fcache->func->returnsSet)
    1733             :     {
    1734        5034 :         ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
    1735             : 
    1736        5034 :         if (es)
    1737             :         {
    1738             :             /*
    1739             :              * If we stopped short of being done, we must have a lazy-eval
    1740             :              * row.
    1741             :              */
    1742             :             Assert(es->lazyEval);
    1743             :             /* The junkfilter's result slot contains the query result tuple */
    1744             :             Assert(fcache->junkFilter);
    1745         994 :             slot = fcache->junkFilter->jf_resultSlot;
    1746             :             Assert(!TTS_EMPTY(slot));
    1747             :             /* Extract the result as a datum, and copy out from the slot */
    1748         994 :             result = postquel_get_single_result(slot, fcinfo, fcache);
    1749             : 
    1750             :             /*
    1751             :              * Let caller know we're not finished.
    1752             :              */
    1753         994 :             rsi->isDone = ExprMultipleResult;
    1754             : 
    1755             :             /*
    1756             :              * Ensure we will get shut down cleanly if the exprcontext is not
    1757             :              * run to completion.
    1758             :              */
    1759         994 :             if (!fcache->shutdown_reg)
    1760             :             {
    1761         726 :                 RegisterExprContextCallback(rsi->econtext,
    1762             :                                             ShutdownSQLFunction,
    1763             :                                             PointerGetDatum(fcache));
    1764         726 :                 fcache->shutdown_reg = true;
    1765             :             }
    1766             :         }
    1767        4040 :         else if (fcache->lazyEval)
    1768             :         {
    1769             :             /*
    1770             :              * We are done with a lazy evaluation.  Let caller know we're
    1771             :              * finished.
    1772             :              */
    1773        3170 :             rsi->isDone = ExprEndResult;
    1774             : 
    1775        3170 :             fcinfo->isnull = true;
    1776        3170 :             result = (Datum) 0;
    1777             : 
    1778             :             /* Deregister shutdown callback, if we made one */
    1779        3170 :             if (fcache->shutdown_reg)
    1780             :             {
    1781         720 :                 UnregisterExprContextCallback(rsi->econtext,
    1782             :                                               ShutdownSQLFunction,
    1783             :                                               PointerGetDatum(fcache));
    1784         720 :                 fcache->shutdown_reg = false;
    1785             :             }
    1786             :         }
    1787             :         else
    1788             :         {
    1789             :             /*
    1790             :              * We are done with a non-lazy evaluation.  Return whatever is in
    1791             :              * the tuplestore.  (It is now caller's responsibility to free the
    1792             :              * tuplestore when done.)
    1793             :              *
    1794             :              * Note an edge case: we could get here without having made a
    1795             :              * tuplestore if the function is declared to return SETOF VOID.
    1796             :              * ExecMakeTableFunctionResult will cope with null setResult.
    1797             :              */
    1798             :             Assert(fcache->tstore || fcache->func->rettype == VOIDOID);
    1799         870 :             rsi->returnMode = SFRM_Materialize;
    1800         870 :             rsi->setResult = fcache->tstore;
    1801         870 :             fcache->tstore = NULL;
    1802             :             /* must copy desc because execSRF.c will free it */
    1803         870 :             if (fcache->junkFilter)
    1804         864 :                 rsi->setDesc = CreateTupleDescCopy(fcache->junkFilter->jf_cleanTupType);
    1805             : 
    1806         870 :             fcinfo->isnull = true;
    1807         870 :             result = (Datum) 0;
    1808             : 
    1809             :             /* Deregister shutdown callback, if we made one */
    1810         870 :             if (fcache->shutdown_reg)
    1811             :             {
    1812           0 :                 UnregisterExprContextCallback(rsi->econtext,
    1813             :                                               ShutdownSQLFunction,
    1814             :                                               PointerGetDatum(fcache));
    1815           0 :                 fcache->shutdown_reg = false;
    1816             :             }
    1817             :         }
    1818             :     }
    1819             :     else
    1820             :     {
    1821             :         /*
    1822             :          * Non-set function.  If we got a row, return it; else return NULL.
    1823             :          */
    1824       74016 :         if (fcache->junkFilter)
    1825             :         {
    1826             :             /* The junkfilter's result slot contains the query result tuple */
    1827       73802 :             slot = fcache->junkFilter->jf_resultSlot;
    1828       73802 :             if (!TTS_EMPTY(slot))
    1829       68974 :                 result = postquel_get_single_result(slot, fcinfo, fcache);
    1830             :             else
    1831             :             {
    1832        4828 :                 fcinfo->isnull = true;
    1833        4828 :                 result = (Datum) 0;
    1834             :             }
    1835             :         }
    1836             :         else
    1837             :         {
    1838             :             /* Should only get here for VOID functions and procedures */
    1839             :             Assert(fcache->func->rettype == VOIDOID);
    1840         214 :             fcinfo->isnull = true;
    1841         214 :             result = (Datum) 0;
    1842             :         }
    1843             :     }
    1844             : 
    1845             :     /* Pop snapshot if we have pushed one */
    1846       79050 :     if (pushed_snapshot)
    1847         646 :         PopActiveSnapshot();
    1848             : 
    1849             :     /*
    1850             :      * If we've gone through every command in the function, we are done. Reset
    1851             :      * state to start over again on next call.
    1852             :      */
    1853       79050 :     if (es == NULL)
    1854       78056 :         fcache->eslist = NULL;
    1855             : 
    1856       79050 :     error_context_stack = sqlerrcontext.previous;
    1857             : 
    1858       79050 :     return result;
    1859             : }
    1860             : 
    1861             : 
    1862             : /*
    1863             :  * error context callback to let us supply a traceback during compile
    1864             :  */
    1865             : static void
    1866           6 : sql_compile_error_callback(void *arg)
    1867             : {
    1868           6 :     SQLFunctionHashEntry *func = (SQLFunctionHashEntry *) arg;
    1869             :     int         syntaxerrposition;
    1870             : 
    1871             :     /*
    1872             :      * We can do nothing useful if sql_compile_callback() didn't get as far as
    1873             :      * copying the function name
    1874             :      */
    1875           6 :     if (func->fname == NULL)
    1876           0 :         return;
    1877             : 
    1878             :     /*
    1879             :      * If there is a syntax error position, convert to internal syntax error
    1880             :      */
    1881           6 :     syntaxerrposition = geterrposition();
    1882           6 :     if (syntaxerrposition > 0 && func->src != NULL)
    1883             :     {
    1884           0 :         errposition(0);
    1885           0 :         internalerrposition(syntaxerrposition);
    1886           0 :         internalerrquery(func->src);
    1887             :     }
    1888             : 
    1889             :     /*
    1890             :      * sql_compile_callback() doesn't do any per-query processing, so just
    1891             :      * report the context as "during startup".
    1892             :      */
    1893           6 :     errcontext("SQL function \"%s\" during startup", func->fname);
    1894             : }
    1895             : 
    1896             : /*
    1897             :  * error context callback to let us supply a call-stack traceback at runtime
    1898             :  */
    1899             : static void
    1900        7928 : sql_exec_error_callback(void *arg)
    1901             : {
    1902        7928 :     SQLFunctionCachePtr fcache = (SQLFunctionCachePtr) arg;
    1903             :     int         syntaxerrposition;
    1904             : 
    1905             :     /*
    1906             :      * If there is a syntax error position, convert to internal syntax error
    1907             :      */
    1908        7928 :     syntaxerrposition = geterrposition();
    1909        7928 :     if (syntaxerrposition > 0 && fcache->func->src != NULL)
    1910             :     {
    1911           2 :         errposition(0);
    1912           2 :         internalerrposition(syntaxerrposition);
    1913           2 :         internalerrquery(fcache->func->src);
    1914             :     }
    1915             : 
    1916             :     /*
    1917             :      * If we failed while executing an identifiable query within the function,
    1918             :      * report that.  Otherwise say it was "during startup".
    1919             :      */
    1920        7928 :     if (fcache->error_query_index > 0)
    1921        7928 :         errcontext("SQL function \"%s\" statement %d",
    1922        7928 :                    fcache->func->fname, fcache->error_query_index);
    1923             :     else
    1924           0 :         errcontext("SQL function \"%s\" during startup", fcache->func->fname);
    1925        7928 : }
    1926             : 
    1927             : 
    1928             : /*
    1929             :  * ExprContext callback function
    1930             :  *
    1931             :  * We register this in the active ExprContext while a set-returning SQL
    1932             :  * function is running, in case the function needs to be shut down before it
    1933             :  * has been run to completion.  Note that this will not be called during an
    1934             :  * error abort, but we don't need it because transaction abort will take care
    1935             :  * of releasing executor resources.
    1936             :  */
    1937             : static void
    1938           6 : ShutdownSQLFunction(Datum arg)
    1939             : {
    1940           6 :     SQLFunctionCachePtr fcache = (SQLFunctionCachePtr) DatumGetPointer(arg);
    1941             :     execution_state *es;
    1942             : 
    1943           6 :     es = fcache->eslist;
    1944          12 :     while (es)
    1945             :     {
    1946             :         /* Shut down anything still running */
    1947           6 :         if (es->status == F_EXEC_RUN)
    1948             :         {
    1949             :             /* Re-establish active snapshot for any called functions */
    1950           6 :             if (!fcache->func->readonly_func)
    1951           6 :                 PushActiveSnapshot(es->qd->snapshot);
    1952             : 
    1953           6 :             postquel_end(es, fcache);
    1954             : 
    1955           6 :             if (!fcache->func->readonly_func)
    1956           6 :                 PopActiveSnapshot();
    1957             :         }
    1958           6 :         es = es->next;
    1959             :     }
    1960           6 :     fcache->eslist = NULL;
    1961             : 
    1962             :     /* Release tuplestore if we have one */
    1963           6 :     if (fcache->tstore)
    1964           0 :         tuplestore_end(fcache->tstore);
    1965           6 :     fcache->tstore = NULL;
    1966             : 
    1967             :     /* Release CachedPlan if we have one */
    1968           6 :     if (fcache->cplan)
    1969           6 :         ReleaseCachedPlan(fcache->cplan, fcache->cowner);
    1970           6 :     fcache->cplan = NULL;
    1971             : 
    1972             :     /* execUtils will deregister the callback... */
    1973           6 :     fcache->shutdown_reg = false;
    1974           6 : }
    1975             : 
    1976             : /*
    1977             :  * MemoryContext callback function
    1978             :  *
    1979             :  * We register this in the memory context that contains a SQLFunctionCache
    1980             :  * struct.  When the memory context is reset or deleted, we release the
    1981             :  * reference count (if any) that the cache holds on the long-lived hash entry.
    1982             :  * Note that this will happen even during error aborts.
    1983             :  */
    1984             : static void
    1985       34048 : RemoveSQLFunctionCache(void *arg)
    1986             : {
    1987       34048 :     SQLFunctionCache *fcache = (SQLFunctionCache *) arg;
    1988             : 
    1989             :     /* Release reference count on SQLFunctionHashEntry */
    1990       34048 :     if (fcache->func != NULL)
    1991             :     {
    1992             :         Assert(fcache->func->cfunc.use_count > 0);
    1993       34042 :         fcache->func->cfunc.use_count--;
    1994             :         /* This should be unnecessary, but let's just be sure: */
    1995       34042 :         fcache->func = NULL;
    1996             :     }
    1997       34048 : }
    1998             : 
    1999             : /*
    2000             :  * check_sql_fn_statements
    2001             :  *
    2002             :  * Check statements in an SQL function.  Error out if there is anything that
    2003             :  * is not acceptable.
    2004             :  */
    2005             : void
    2006        7258 : check_sql_fn_statements(List *queryTreeLists)
    2007             : {
    2008             :     ListCell   *lc;
    2009             : 
    2010             :     /* We are given a list of sublists of Queries */
    2011       14626 :     foreach(lc, queryTreeLists)
    2012             :     {
    2013        7374 :         List       *sublist = lfirst_node(List, lc);
    2014             : 
    2015        7374 :         check_sql_fn_statement(sublist);
    2016             :     }
    2017        7252 : }
    2018             : 
    2019             : /*
    2020             :  * As above, for a single sublist of Queries.
    2021             :  */
    2022             : static void
    2023        9922 : check_sql_fn_statement(List *queryTreeList)
    2024             : {
    2025             :     ListCell   *lc;
    2026             : 
    2027       19844 :     foreach(lc, queryTreeList)
    2028             :     {
    2029        9928 :         Query      *query = lfirst_node(Query, lc);
    2030             : 
    2031             :         /*
    2032             :          * Disallow calling procedures with output arguments.  The current
    2033             :          * implementation would just throw the output values away, unless the
    2034             :          * statement is the last one.  Per SQL standard, we should assign the
    2035             :          * output values by name.  By disallowing this here, we preserve an
    2036             :          * opportunity for future improvement.
    2037             :          */
    2038        9928 :         if (query->commandType == CMD_UTILITY &&
    2039         154 :             IsA(query->utilityStmt, CallStmt))
    2040             :         {
    2041          30 :             CallStmt   *stmt = (CallStmt *) query->utilityStmt;
    2042             : 
    2043          30 :             if (stmt->outargs != NIL)
    2044           6 :                 ereport(ERROR,
    2045             :                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2046             :                          errmsg("calling procedures with output arguments is not supported in SQL functions")));
    2047             :         }
    2048             :     }
    2049        9916 : }
    2050             : 
    2051             : /*
    2052             :  * check_sql_fn_retval()
    2053             :  *      Check return value of a list of lists of sql parse trees.
    2054             :  *
    2055             :  * The return value of a sql function is the value returned by the last
    2056             :  * canSetTag query in the function.  We do some ad-hoc type checking and
    2057             :  * coercion here to ensure that the function returns what it's supposed to.
    2058             :  * Note that we may actually modify the last query to make it match!
    2059             :  *
    2060             :  * This function returns true if the sql function returns the entire tuple
    2061             :  * result of its final statement, or false if it returns just the first column
    2062             :  * result of that statement.  It throws an error if the final statement doesn't
    2063             :  * return the right type at all.
    2064             :  *
    2065             :  * Note that because we allow "SELECT rowtype_expression", the result can be
    2066             :  * false even when the declared function return type is a rowtype.
    2067             :  *
    2068             :  * For a polymorphic function the passed rettype must be the actual resolved
    2069             :  * output type of the function.  (This means we can't check the type during
    2070             :  * function definition of a polymorphic function.)  If we do see a polymorphic
    2071             :  * rettype we'll throw an error, saying it is not a supported rettype.
    2072             :  *
    2073             :  * If the function returns composite, the passed rettupdesc should describe
    2074             :  * the expected output.  If rettupdesc is NULL, we can't verify that the
    2075             :  * output matches; that should only happen in fmgr_sql_validator(), or when
    2076             :  * the function returns RECORD and the caller doesn't actually care which
    2077             :  * composite type it is.
    2078             :  *
    2079             :  * (Typically, rettype and rettupdesc are computed by get_call_result_type
    2080             :  * or a sibling function.)
    2081             :  *
    2082             :  * In addition to coercing individual output columns, we can modify the
    2083             :  * output to include dummy NULL columns for any dropped columns appearing
    2084             :  * in rettupdesc.  This is done only if the caller asks for it.
    2085             :  */
    2086             : bool
    2087       10802 : check_sql_fn_retval(List *queryTreeLists,
    2088             :                     Oid rettype, TupleDesc rettupdesc,
    2089             :                     char prokind,
    2090             :                     bool insertDroppedCols)
    2091             : {
    2092             :     List       *queryTreeList;
    2093             : 
    2094             :     /*
    2095             :      * We consider only the last sublist of Query nodes, so that only the last
    2096             :      * original statement is a candidate to produce the result.  This is a
    2097             :      * change from pre-v18 versions, which would back up to the last statement
    2098             :      * that includes a canSetTag query, thus ignoring any ending statement(s)
    2099             :      * that rewrite to DO INSTEAD NOTHING.  That behavior was undocumented and
    2100             :      * there seems no good reason for it, except that it was an artifact of
    2101             :      * the original coding.
    2102             :      *
    2103             :      * If the function body is completely empty, handle that the same as if
    2104             :      * the last query had rewritten to nothing.
    2105             :      */
    2106       10802 :     if (queryTreeLists != NIL)
    2107       10778 :         queryTreeList = llast_node(List, queryTreeLists);
    2108             :     else
    2109          24 :         queryTreeList = NIL;
    2110             : 
    2111       10802 :     return check_sql_stmt_retval(queryTreeList,
    2112             :                                  rettype, rettupdesc,
    2113             :                                  prokind, insertDroppedCols);
    2114             : }
    2115             : 
    2116             : /*
    2117             :  * As for check_sql_fn_retval, but we are given just the last query's
    2118             :  * rewritten-queries list.
    2119             :  */
    2120             : static bool
    2121       13280 : check_sql_stmt_retval(List *queryTreeList,
    2122             :                       Oid rettype, TupleDesc rettupdesc,
    2123             :                       char prokind, bool insertDroppedCols)
    2124             : {
    2125       13280 :     bool        is_tuple_result = false;
    2126             :     Query      *parse;
    2127             :     ListCell   *parse_cell;
    2128             :     List       *tlist;
    2129             :     int         tlistlen;
    2130             :     bool        tlist_is_modifiable;
    2131             :     char        fn_typtype;
    2132       13280 :     List       *upper_tlist = NIL;
    2133       13280 :     bool        upper_tlist_nontrivial = false;
    2134             :     ListCell   *lc;
    2135             : 
    2136             :     /*
    2137             :      * If it's declared to return VOID, we don't care what's in the function.
    2138             :      * (This takes care of procedures with no output parameters, as well.)
    2139             :      */
    2140       13280 :     if (rettype == VOIDOID)
    2141         622 :         return false;
    2142             : 
    2143             :     /*
    2144             :      * Find the last canSetTag query in the list of Query nodes.  This isn't
    2145             :      * necessarily the last parsetree, because rule rewriting can insert
    2146             :      * queries after what the user wrote.
    2147             :      */
    2148       12658 :     parse = NULL;
    2149       12658 :     parse_cell = NULL;
    2150       25316 :     foreach(lc, queryTreeList)
    2151             :     {
    2152       12658 :         Query      *q = lfirst_node(Query, lc);
    2153             : 
    2154       12658 :         if (q->canSetTag)
    2155             :         {
    2156       12652 :             parse = q;
    2157       12652 :             parse_cell = lc;
    2158             :         }
    2159             :     }
    2160             : 
    2161             :     /*
    2162             :      * If it's a plain SELECT, it returns whatever the targetlist says.
    2163             :      * Otherwise, if it's INSERT/UPDATE/DELETE/MERGE with RETURNING, it
    2164             :      * returns that. Otherwise, the function return type must be VOID.
    2165             :      *
    2166             :      * Note: eventually replace this test with QueryReturnsTuples?  We'd need
    2167             :      * a more general method of determining the output type, though.  Also, it
    2168             :      * seems too dangerous to consider FETCH or EXECUTE as returning a
    2169             :      * determinable rowtype, since they depend on relatively short-lived
    2170             :      * entities.
    2171             :      */
    2172       12658 :     if (parse &&
    2173       12652 :         parse->commandType == CMD_SELECT)
    2174             :     {
    2175       12538 :         tlist = parse->targetList;
    2176             :         /* tlist is modifiable unless it's a dummy in a setop query */
    2177       12538 :         tlist_is_modifiable = (parse->setOperations == NULL);
    2178             :     }
    2179         120 :     else if (parse &&
    2180         114 :              (parse->commandType == CMD_INSERT ||
    2181          30 :               parse->commandType == CMD_UPDATE ||
    2182          30 :               parse->commandType == CMD_DELETE ||
    2183          30 :               parse->commandType == CMD_MERGE) &&
    2184         114 :              parse->returningList)
    2185             :     {
    2186         114 :         tlist = parse->returningList;
    2187             :         /* returningList can always be modified */
    2188         114 :         tlist_is_modifiable = true;
    2189             :     }
    2190             :     else
    2191             :     {
    2192             :         /* Last statement is a utility command, or it rewrote to nothing */
    2193           6 :         ereport(ERROR,
    2194             :                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2195             :                  errmsg("return type mismatch in function declared to return %s",
    2196             :                         format_type_be(rettype)),
    2197             :                  errdetail("Function's final statement must be SELECT or INSERT/UPDATE/DELETE/MERGE RETURNING.")));
    2198             :         return false;           /* keep compiler quiet */
    2199             :     }
    2200             : 
    2201             :     /*
    2202             :      * OK, check that the targetlist returns something matching the declared
    2203             :      * type, and modify it if necessary.  If possible, we insert any coercion
    2204             :      * steps right into the final statement's targetlist.  However, that might
    2205             :      * risk changes in the statement's semantics --- we can't safely change
    2206             :      * the output type of a grouping column, for instance.  In such cases we
    2207             :      * handle coercions by inserting an extra level of Query that effectively
    2208             :      * just does a projection.
    2209             :      */
    2210             : 
    2211             :     /*
    2212             :      * Count the non-junk entries in the result targetlist.
    2213             :      */
    2214       12652 :     tlistlen = ExecCleanTargetListLength(tlist);
    2215             : 
    2216       12652 :     fn_typtype = get_typtype(rettype);
    2217             : 
    2218       12652 :     if (fn_typtype == TYPTYPE_BASE ||
    2219        1426 :         fn_typtype == TYPTYPE_DOMAIN ||
    2220        1420 :         fn_typtype == TYPTYPE_ENUM ||
    2221        1384 :         fn_typtype == TYPTYPE_RANGE ||
    2222             :         fn_typtype == TYPTYPE_MULTIRANGE)
    2223       11292 :     {
    2224             :         /*
    2225             :          * For scalar-type returns, the target list must have exactly one
    2226             :          * non-junk entry, and its type must be coercible to rettype.
    2227             :          */
    2228             :         TargetEntry *tle;
    2229             : 
    2230       11304 :         if (tlistlen != 1)
    2231           6 :             ereport(ERROR,
    2232             :                     (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2233             :                      errmsg("return type mismatch in function declared to return %s",
    2234             :                             format_type_be(rettype)),
    2235             :                      errdetail("Final statement must return exactly one column.")));
    2236             : 
    2237             :         /* We assume here that non-junk TLEs must come first in tlists */
    2238       11298 :         tle = (TargetEntry *) linitial(tlist);
    2239             :         Assert(!tle->resjunk);
    2240             : 
    2241       11298 :         if (!coerce_fn_result_column(tle, rettype, -1,
    2242             :                                      tlist_is_modifiable,
    2243             :                                      &upper_tlist,
    2244             :                                      &upper_tlist_nontrivial))
    2245           6 :             ereport(ERROR,
    2246             :                     (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2247             :                      errmsg("return type mismatch in function declared to return %s",
    2248             :                             format_type_be(rettype)),
    2249             :                      errdetail("Actual return type is %s.",
    2250             :                                format_type_be(exprType((Node *) tle->expr)))));
    2251             :     }
    2252        1348 :     else if (fn_typtype == TYPTYPE_COMPOSITE || rettype == RECORDOID)
    2253        1210 :     {
    2254             :         /*
    2255             :          * Returns a rowtype.
    2256             :          *
    2257             :          * Note that we will not consider a domain over composite to be a
    2258             :          * "rowtype" return type; it goes through the scalar case above.  This
    2259             :          * is because we only provide column-by-column implicit casting, and
    2260             :          * will not cast the complete record result.  So the only way to
    2261             :          * produce a domain-over-composite result is to compute it as an
    2262             :          * explicit single-column result.  The single-composite-column code
    2263             :          * path just below could handle such cases, but it won't be reached.
    2264             :          */
    2265             :         int         tupnatts;   /* physical number of columns in tuple */
    2266             :         int         tuplogcols; /* # of nondeleted columns in tuple */
    2267             :         int         colindex;   /* physical column index */
    2268             : 
    2269             :         /*
    2270             :          * If the target list has one non-junk entry, and that expression has
    2271             :          * or can be coerced to the declared return type, take it as the
    2272             :          * result.  This allows, for example, 'SELECT func2()', where func2
    2273             :          * has the same composite return type as the function that's calling
    2274             :          * it.  This provision creates some ambiguity --- maybe the expression
    2275             :          * was meant to be the lone field of the composite result --- but it
    2276             :          * works well enough as long as we don't get too enthusiastic about
    2277             :          * inventing coercions from scalar to composite types.
    2278             :          *
    2279             :          * XXX Note that if rettype is RECORD and the expression is of a named
    2280             :          * composite type, or vice versa, this coercion will succeed, whether
    2281             :          * or not the record type really matches.  For the moment we rely on
    2282             :          * runtime type checking to catch any discrepancy, but it'd be nice to
    2283             :          * do better at parse time.
    2284             :          *
    2285             :          * We must *not* do this for a procedure, however.  Procedures with
    2286             :          * output parameter(s) have rettype RECORD, and the CALL code expects
    2287             :          * to get results corresponding to the list of output parameters, even
    2288             :          * when there's just one parameter that's composite.
    2289             :          */
    2290        1342 :         if (tlistlen == 1 && prokind != PROKIND_PROCEDURE)
    2291             :         {
    2292         216 :             TargetEntry *tle = (TargetEntry *) linitial(tlist);
    2293             : 
    2294             :             Assert(!tle->resjunk);
    2295         216 :             if (coerce_fn_result_column(tle, rettype, -1,
    2296             :                                         tlist_is_modifiable,
    2297             :                                         &upper_tlist,
    2298             :                                         &upper_tlist_nontrivial))
    2299             :             {
    2300             :                 /* Note that we're NOT setting is_tuple_result */
    2301          72 :                 goto tlist_coercion_finished;
    2302             :             }
    2303             :         }
    2304             : 
    2305             :         /*
    2306             :          * If the caller didn't provide an expected tupdesc, we can't do any
    2307             :          * further checking.  Assume we're returning the whole tuple.
    2308             :          */
    2309        1270 :         if (rettupdesc == NULL)
    2310          48 :             return true;
    2311             : 
    2312             :         /*
    2313             :          * Verify that the targetlist matches the return tuple type.  We scan
    2314             :          * the non-resjunk columns, and coerce them if necessary to match the
    2315             :          * datatypes of the non-deleted attributes.  For deleted attributes,
    2316             :          * insert NULL result columns if the caller asked for that.
    2317             :          */
    2318        1222 :         tupnatts = rettupdesc->natts;
    2319        1222 :         tuplogcols = 0;         /* we'll count nondeleted cols as we go */
    2320        1222 :         colindex = 0;
    2321             : 
    2322        4688 :         foreach(lc, tlist)
    2323             :         {
    2324        3478 :             TargetEntry *tle = (TargetEntry *) lfirst(lc);
    2325             :             Form_pg_attribute attr;
    2326             : 
    2327             :             /* resjunk columns can simply be ignored */
    2328        3478 :             if (tle->resjunk)
    2329           0 :                 continue;
    2330             : 
    2331             :             do
    2332             :             {
    2333        3532 :                 colindex++;
    2334        3532 :                 if (colindex > tupnatts)
    2335           0 :                     ereport(ERROR,
    2336             :                             (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2337             :                              errmsg("return type mismatch in function declared to return %s",
    2338             :                                     format_type_be(rettype)),
    2339             :                              errdetail("Final statement returns too many columns.")));
    2340        3532 :                 attr = TupleDescAttr(rettupdesc, colindex - 1);
    2341        3532 :                 if (attr->attisdropped && insertDroppedCols)
    2342             :                 {
    2343             :                     Expr       *null_expr;
    2344             : 
    2345             :                     /* The type of the null we insert isn't important */
    2346           6 :                     null_expr = (Expr *) makeConst(INT4OID,
    2347             :                                                    -1,
    2348             :                                                    InvalidOid,
    2349             :                                                    sizeof(int32),
    2350             :                                                    (Datum) 0,
    2351             :                                                    true,    /* isnull */
    2352             :                                                    true /* byval */ );
    2353           6 :                     upper_tlist = lappend(upper_tlist,
    2354           6 :                                           makeTargetEntry(null_expr,
    2355           6 :                                                           list_length(upper_tlist) + 1,
    2356             :                                                           NULL,
    2357             :                                                           false));
    2358           6 :                     upper_tlist_nontrivial = true;
    2359             :                 }
    2360        3532 :             } while (attr->attisdropped);
    2361        3478 :             tuplogcols++;
    2362             : 
    2363        3478 :             if (!coerce_fn_result_column(tle,
    2364             :                                          attr->atttypid, attr->atttypmod,
    2365             :                                          tlist_is_modifiable,
    2366             :                                          &upper_tlist,
    2367             :                                          &upper_tlist_nontrivial))
    2368          12 :                 ereport(ERROR,
    2369             :                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2370             :                          errmsg("return type mismatch in function declared to return %s",
    2371             :                                 format_type_be(rettype)),
    2372             :                          errdetail("Final statement returns %s instead of %s at column %d.",
    2373             :                                    format_type_be(exprType((Node *) tle->expr)),
    2374             :                                    format_type_be(attr->atttypid),
    2375             :                                    tuplogcols)));
    2376             :         }
    2377             : 
    2378             :         /* remaining columns in rettupdesc had better all be dropped */
    2379        1210 :         for (colindex++; colindex <= tupnatts; colindex++)
    2380             :         {
    2381           0 :             if (!TupleDescCompactAttr(rettupdesc, colindex - 1)->attisdropped)
    2382           0 :                 ereport(ERROR,
    2383             :                         (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2384             :                          errmsg("return type mismatch in function declared to return %s",
    2385             :                                 format_type_be(rettype)),
    2386             :                          errdetail("Final statement returns too few columns.")));
    2387           0 :             if (insertDroppedCols)
    2388             :             {
    2389             :                 Expr       *null_expr;
    2390             : 
    2391             :                 /* The type of the null we insert isn't important */
    2392           0 :                 null_expr = (Expr *) makeConst(INT4OID,
    2393             :                                                -1,
    2394             :                                                InvalidOid,
    2395             :                                                sizeof(int32),
    2396             :                                                (Datum) 0,
    2397             :                                                true,    /* isnull */
    2398             :                                                true /* byval */ );
    2399           0 :                 upper_tlist = lappend(upper_tlist,
    2400           0 :                                       makeTargetEntry(null_expr,
    2401           0 :                                                       list_length(upper_tlist) + 1,
    2402             :                                                       NULL,
    2403             :                                                       false));
    2404           0 :                 upper_tlist_nontrivial = true;
    2405             :             }
    2406             :         }
    2407             : 
    2408             :         /* Report that we are returning entire tuple result */
    2409        1210 :         is_tuple_result = true;
    2410             :     }
    2411             :     else
    2412           6 :         ereport(ERROR,
    2413             :                 (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
    2414             :                  errmsg("return type %s is not supported for SQL functions",
    2415             :                         format_type_be(rettype))));
    2416             : 
    2417       12574 : tlist_coercion_finished:
    2418             : 
    2419             :     /*
    2420             :      * If necessary, modify the final Query by injecting an extra Query level
    2421             :      * that just performs a projection.  (It'd be dubious to do this to a
    2422             :      * non-SELECT query, but we never have to; RETURNING lists can always be
    2423             :      * modified in-place.)
    2424             :      */
    2425       12574 :     if (upper_tlist_nontrivial)
    2426             :     {
    2427             :         Query      *newquery;
    2428             :         List       *colnames;
    2429             :         RangeTblEntry *rte;
    2430             :         RangeTblRef *rtr;
    2431             : 
    2432             :         Assert(parse->commandType == CMD_SELECT);
    2433             : 
    2434             :         /* Most of the upper Query struct can be left as zeroes/nulls */
    2435          84 :         newquery = makeNode(Query);
    2436          84 :         newquery->commandType = CMD_SELECT;
    2437          84 :         newquery->querySource = parse->querySource;
    2438          84 :         newquery->canSetTag = true;
    2439          84 :         newquery->targetList = upper_tlist;
    2440             : 
    2441             :         /* We need a moderately realistic colnames list for the subquery RTE */
    2442          84 :         colnames = NIL;
    2443         216 :         foreach(lc, parse->targetList)
    2444             :         {
    2445         132 :             TargetEntry *tle = (TargetEntry *) lfirst(lc);
    2446             : 
    2447         132 :             if (tle->resjunk)
    2448           0 :                 continue;
    2449         132 :             colnames = lappend(colnames,
    2450         132 :                                makeString(tle->resname ? tle->resname : ""));
    2451             :         }
    2452             : 
    2453             :         /* Build a suitable RTE for the subquery */
    2454          84 :         rte = makeNode(RangeTblEntry);
    2455          84 :         rte->rtekind = RTE_SUBQUERY;
    2456          84 :         rte->subquery = parse;
    2457          84 :         rte->eref = rte->alias = makeAlias("*SELECT*", colnames);
    2458          84 :         rte->lateral = false;
    2459          84 :         rte->inh = false;
    2460          84 :         rte->inFromCl = true;
    2461          84 :         newquery->rtable = list_make1(rte);
    2462             : 
    2463          84 :         rtr = makeNode(RangeTblRef);
    2464          84 :         rtr->rtindex = 1;
    2465          84 :         newquery->jointree = makeFromExpr(list_make1(rtr), NULL);
    2466             : 
    2467             :         /*
    2468             :          * Make sure the new query is marked as having row security if the
    2469             :          * original one does.
    2470             :          */
    2471          84 :         newquery->hasRowSecurity = parse->hasRowSecurity;
    2472             : 
    2473             :         /* Replace original query in the correct element of the query list */
    2474          84 :         lfirst(parse_cell) = newquery;
    2475             :     }
    2476             : 
    2477       12574 :     return is_tuple_result;
    2478             : }
    2479             : 
    2480             : /*
    2481             :  * Process one function result column for check_sql_fn_retval
    2482             :  *
    2483             :  * Coerce the output value to the required type/typmod, and add a column
    2484             :  * to *upper_tlist for it.  Set *upper_tlist_nontrivial to true if we
    2485             :  * add an upper tlist item that's not just a Var.
    2486             :  *
    2487             :  * Returns true if OK, false if could not coerce to required type
    2488             :  * (in which case, no changes have been made)
    2489             :  */
    2490             : static bool
    2491       14992 : coerce_fn_result_column(TargetEntry *src_tle,
    2492             :                         Oid res_type,
    2493             :                         int32 res_typmod,
    2494             :                         bool tlist_is_modifiable,
    2495             :                         List **upper_tlist,
    2496             :                         bool *upper_tlist_nontrivial)
    2497             : {
    2498             :     TargetEntry *new_tle;
    2499             :     Expr       *new_tle_expr;
    2500             :     Node       *cast_result;
    2501             : 
    2502             :     /*
    2503             :      * If the TLE has a sortgroupref marking, don't change it, as it probably
    2504             :      * is referenced by ORDER BY, DISTINCT, etc, and changing its type would
    2505             :      * break query semantics.  Otherwise, it's safe to modify in-place unless
    2506             :      * the query as a whole has issues with that.
    2507             :      */
    2508       14992 :     if (tlist_is_modifiable && src_tle->ressortgroupref == 0)
    2509             :     {
    2510             :         /* OK to modify src_tle in place, if necessary */
    2511       29524 :         cast_result = coerce_to_target_type(NULL,
    2512       14762 :                                             (Node *) src_tle->expr,
    2513       14762 :                                             exprType((Node *) src_tle->expr),
    2514             :                                             res_type, res_typmod,
    2515             :                                             COERCION_ASSIGNMENT,
    2516             :                                             COERCE_IMPLICIT_CAST,
    2517             :                                             -1);
    2518       14762 :         if (cast_result == NULL)
    2519         144 :             return false;
    2520       14618 :         assign_expr_collations(NULL, cast_result);
    2521       14618 :         src_tle->expr = (Expr *) cast_result;
    2522             :         /* Make a Var referencing the possibly-modified TLE */
    2523       14618 :         new_tle_expr = (Expr *) makeVarFromTargetEntry(1, src_tle);
    2524             :     }
    2525             :     else
    2526             :     {
    2527             :         /* Any casting must happen in the upper tlist */
    2528         230 :         Var        *var = makeVarFromTargetEntry(1, src_tle);
    2529             : 
    2530         230 :         cast_result = coerce_to_target_type(NULL,
    2531             :                                             (Node *) var,
    2532             :                                             var->vartype,
    2533             :                                             res_type, res_typmod,
    2534             :                                             COERCION_ASSIGNMENT,
    2535             :                                             COERCE_IMPLICIT_CAST,
    2536             :                                             -1);
    2537         230 :         if (cast_result == NULL)
    2538          18 :             return false;
    2539         212 :         assign_expr_collations(NULL, cast_result);
    2540             :         /* Did the coercion actually do anything? */
    2541         212 :         if (cast_result != (Node *) var)
    2542         102 :             *upper_tlist_nontrivial = true;
    2543         212 :         new_tle_expr = (Expr *) cast_result;
    2544             :     }
    2545       29660 :     new_tle = makeTargetEntry(new_tle_expr,
    2546       14830 :                               list_length(*upper_tlist) + 1,
    2547             :                               src_tle->resname, false);
    2548       14830 :     *upper_tlist = lappend(*upper_tlist, new_tle);
    2549       14830 :     return true;
    2550             : }
    2551             : 
    2552             : /*
    2553             :  * Extract the targetlist of the last canSetTag query in the given list
    2554             :  * of parsed-and-rewritten Queries.  Returns NIL if there is none.
    2555             :  */
    2556             : static List *
    2557       35810 : get_sql_fn_result_tlist(List *queryTreeList)
    2558             : {
    2559       35810 :     Query      *parse = NULL;
    2560             :     ListCell   *lc;
    2561             : 
    2562       71626 :     foreach(lc, queryTreeList)
    2563             :     {
    2564       35816 :         Query      *q = lfirst_node(Query, lc);
    2565             : 
    2566       35816 :         if (q->canSetTag)
    2567       35810 :             parse = q;
    2568             :     }
    2569       35810 :     if (parse &&
    2570       35810 :         parse->commandType == CMD_SELECT)
    2571       35714 :         return parse->targetList;
    2572          96 :     else if (parse &&
    2573          96 :              (parse->commandType == CMD_INSERT ||
    2574          24 :               parse->commandType == CMD_UPDATE ||
    2575          24 :               parse->commandType == CMD_DELETE ||
    2576          24 :               parse->commandType == CMD_MERGE) &&
    2577          96 :              parse->returningList)
    2578          96 :         return parse->returningList;
    2579             :     else
    2580           0 :         return NIL;
    2581             : }
    2582             : 
    2583             : 
    2584             : /*
    2585             :  * CreateSQLFunctionDestReceiver -- create a suitable DestReceiver object
    2586             :  */
    2587             : DestReceiver *
    2588       85566 : CreateSQLFunctionDestReceiver(void)
    2589             : {
    2590       85566 :     DR_sqlfunction *self = (DR_sqlfunction *) palloc0(sizeof(DR_sqlfunction));
    2591             : 
    2592       85566 :     self->pub.receiveSlot = sqlfunction_receive;
    2593       85566 :     self->pub.rStartup = sqlfunction_startup;
    2594       85566 :     self->pub.rShutdown = sqlfunction_shutdown;
    2595       85566 :     self->pub.rDestroy = sqlfunction_destroy;
    2596       85566 :     self->pub.mydest = DestSQLFunction;
    2597             : 
    2598             :     /* private fields will be set by postquel_start */
    2599             : 
    2600       85566 :     return (DestReceiver *) self;
    2601             : }
    2602             : 
    2603             : /*
    2604             :  * sqlfunction_startup --- executor startup
    2605             :  */
    2606             : static void
    2607       86548 : sqlfunction_startup(DestReceiver *self, int operation, TupleDesc typeinfo)
    2608             : {
    2609             :     /* no-op */
    2610       86548 : }
    2611             : 
    2612             : /*
    2613             :  * sqlfunction_receive --- receive one tuple
    2614             :  */
    2615             : static bool
    2616      192318 : sqlfunction_receive(TupleTableSlot *slot, DestReceiver *self)
    2617             : {
    2618      192318 :     DR_sqlfunction *myState = (DR_sqlfunction *) self;
    2619             : 
    2620      192318 :     if (myState->tstore)
    2621             :     {
    2622             :         /* We are collecting all of a set result into the tuplestore */
    2623             : 
    2624             :         /* Filter tuple as needed */
    2625      122344 :         slot = ExecFilterJunk(myState->filter, slot);
    2626             : 
    2627             :         /* Store the filtered tuple into the tuplestore */
    2628      122344 :         tuplestore_puttupleslot(myState->tstore, slot);
    2629             :     }
    2630             :     else
    2631             :     {
    2632             :         /*
    2633             :          * We only want the first tuple, which we'll save in the junkfilter's
    2634             :          * result slot.  Ignore any additional tuples passed.
    2635             :          */
    2636       69974 :         if (TTS_EMPTY(myState->filter->jf_resultSlot))
    2637             :         {
    2638             :             /* Filter tuple as needed */
    2639       69968 :             slot = ExecFilterJunk(myState->filter, slot);
    2640             :             Assert(slot == myState->filter->jf_resultSlot);
    2641             : 
    2642             :             /* Materialize the slot so it preserves pass-by-ref values */
    2643       69968 :             ExecMaterializeSlot(slot);
    2644             :         }
    2645             :     }
    2646             : 
    2647      192318 :     return true;
    2648             : }
    2649             : 
    2650             : /*
    2651             :  * sqlfunction_shutdown --- executor end
    2652             :  */
    2653             : static void
    2654       78830 : sqlfunction_shutdown(DestReceiver *self)
    2655             : {
    2656             :     /* no-op */
    2657       78830 : }
    2658             : 
    2659             : /*
    2660             :  * sqlfunction_destroy --- release DestReceiver object
    2661             :  */
    2662             : static void
    2663       77842 : sqlfunction_destroy(DestReceiver *self)
    2664             : {
    2665       77842 :     pfree(self);
    2666       77842 : }

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