LCOV - code coverage report
Current view: top level - src/fe_utils - string_utils.c (source / functions) Hit Total Coverage
Test: PostgreSQL 15devel Lines: 300 349 86.0 %
Date: 2021-09-17 15:07:27 Functions: 15 16 93.8 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * String-processing utility routines for frontend code
       4             :  *
       5             :  * Assorted utility functions that are useful in constructing SQL queries
       6             :  * and interpreting backend output.
       7             :  *
       8             :  *
       9             :  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
      10             :  * Portions Copyright (c) 1994, Regents of the University of California
      11             :  *
      12             :  * src/fe_utils/string_utils.c
      13             :  *
      14             :  *-------------------------------------------------------------------------
      15             :  */
      16             : #include "postgres_fe.h"
      17             : 
      18             : #include <ctype.h>
      19             : 
      20             : #include "common/keywords.h"
      21             : #include "fe_utils/string_utils.h"
      22             : 
      23             : static PQExpBuffer defaultGetLocalPQExpBuffer(void);
      24             : 
      25             : /* Globals exported by this file */
      26             : int         quote_all_identifiers = 0;
      27             : PQExpBuffer (*getLocalPQExpBuffer) (void) = defaultGetLocalPQExpBuffer;
      28             : 
      29             : 
      30             : /*
      31             :  * Returns a temporary PQExpBuffer, valid until the next call to the function.
      32             :  * This is used by fmtId and fmtQualifiedId.
      33             :  *
      34             :  * Non-reentrant and non-thread-safe but reduces memory leakage. You can
      35             :  * replace this with a custom version by setting the getLocalPQExpBuffer
      36             :  * function pointer.
      37             :  */
      38             : static PQExpBuffer
      39      244728 : defaultGetLocalPQExpBuffer(void)
      40             : {
      41             :     static PQExpBuffer id_return = NULL;
      42             : 
      43      244728 :     if (id_return)              /* first time through? */
      44             :     {
      45             :         /* same buffer, just wipe contents */
      46      244296 :         resetPQExpBuffer(id_return);
      47             :     }
      48             :     else
      49             :     {
      50             :         /* new buffer */
      51         432 :         id_return = createPQExpBuffer();
      52             :     }
      53             : 
      54      244728 :     return id_return;
      55             : }
      56             : 
      57             : /*
      58             :  *  Quotes input string if it's not a legitimate SQL identifier as-is.
      59             :  *
      60             :  *  Note that the returned string must be used before calling fmtId again,
      61             :  *  since we re-use the same return buffer each time.
      62             :  */
      63             : const char *
      64      204360 : fmtId(const char *rawid)
      65             : {
      66      204360 :     PQExpBuffer id_return = getLocalPQExpBuffer();
      67             : 
      68             :     const char *cp;
      69      204360 :     bool        need_quotes = false;
      70             : 
      71             :     /*
      72             :      * These checks need to match the identifier production in scan.l. Don't
      73             :      * use islower() etc.
      74             :      */
      75      204360 :     if (quote_all_identifiers)
      76       26040 :         need_quotes = true;
      77             :     /* slightly different rules for first character */
      78      178320 :     else if (!((rawid[0] >= 'a' && rawid[0] <= 'z') || rawid[0] == '_'))
      79         514 :         need_quotes = true;
      80             :     else
      81             :     {
      82             :         /* otherwise check the entire string */
      83     1923906 :         for (cp = rawid; *cp; cp++)
      84             :         {
      85     1746434 :             if (!((*cp >= 'a' && *cp <= 'z')
      86      255936 :                   || (*cp >= '0' && *cp <= '9')
      87      149242 :                   || (*cp == '_')))
      88             :             {
      89         334 :                 need_quotes = true;
      90         334 :                 break;
      91             :             }
      92             :         }
      93             :     }
      94             : 
      95      204360 :     if (!need_quotes)
      96             :     {
      97             :         /*
      98             :          * Check for keyword.  We quote keywords except for unreserved ones.
      99             :          * (In some cases we could avoid quoting a col_name or type_func_name
     100             :          * keyword, but it seems much harder than it's worth to tell that.)
     101             :          *
     102             :          * Note: ScanKeywordLookup() does case-insensitive comparison, but
     103             :          * that's fine, since we already know we have all-lower-case.
     104             :          */
     105      177472 :         int         kwnum = ScanKeywordLookup(rawid, &ScanKeywords);
     106             : 
     107      177472 :         if (kwnum >= 0 && ScanKeywordCategories[kwnum] != UNRESERVED_KEYWORD)
     108         318 :             need_quotes = true;
     109             :     }
     110             : 
     111      204360 :     if (!need_quotes)
     112             :     {
     113             :         /* no quoting needed */
     114      177154 :         appendPQExpBufferStr(id_return, rawid);
     115             :     }
     116             :     else
     117             :     {
     118       27206 :         appendPQExpBufferChar(id_return, '"');
     119      265322 :         for (cp = rawid; *cp; cp++)
     120             :         {
     121             :             /*
     122             :              * Did we find a double-quote in the string? Then make this a
     123             :              * double double-quote per SQL99. Before, we put in a
     124             :              * backslash/double-quote pair. - thomas 2000-08-05
     125             :              */
     126      238116 :             if (*cp == '"')
     127         266 :                 appendPQExpBufferChar(id_return, '"');
     128      238116 :             appendPQExpBufferChar(id_return, *cp);
     129             :         }
     130       27206 :         appendPQExpBufferChar(id_return, '"');
     131             :     }
     132             : 
     133      204360 :     return id_return->data;
     134             : }
     135             : 
     136             : /*
     137             :  * fmtQualifiedId - construct a schema-qualified name, with quoting as needed.
     138             :  *
     139             :  * Like fmtId, use the result before calling again.
     140             :  *
     141             :  * Since we call fmtId and it also uses getLocalPQExpBuffer() we cannot
     142             :  * use that buffer until we're finished with calling fmtId().
     143             :  */
     144             : const char *
     145       40368 : fmtQualifiedId(const char *schema, const char *id)
     146             : {
     147             :     PQExpBuffer id_return;
     148       40368 :     PQExpBuffer lcl_pqexp = createPQExpBuffer();
     149             : 
     150             :     /* Some callers might fail to provide a schema name */
     151       40368 :     if (schema && *schema)
     152             :     {
     153       40368 :         appendPQExpBuffer(lcl_pqexp, "%s.", fmtId(schema));
     154             :     }
     155       40368 :     appendPQExpBufferStr(lcl_pqexp, fmtId(id));
     156             : 
     157       40368 :     id_return = getLocalPQExpBuffer();
     158             : 
     159       40368 :     appendPQExpBufferStr(id_return, lcl_pqexp->data);
     160       40368 :     destroyPQExpBuffer(lcl_pqexp);
     161             : 
     162       40368 :     return id_return->data;
     163             : }
     164             : 
     165             : 
     166             : /*
     167             :  * Format a Postgres version number (in the PG_VERSION_NUM integer format
     168             :  * returned by PQserverVersion()) as a string.  This exists mainly to
     169             :  * encapsulate knowledge about two-part vs. three-part version numbers.
     170             :  *
     171             :  * For reentrancy, caller must supply the buffer the string is put in.
     172             :  * Recommended size of the buffer is 32 bytes.
     173             :  *
     174             :  * Returns address of 'buf', as a notational convenience.
     175             :  */
     176             : char *
     177           0 : formatPGVersionNumber(int version_number, bool include_minor,
     178             :                       char *buf, size_t buflen)
     179             : {
     180           0 :     if (version_number >= 100000)
     181             :     {
     182             :         /* New two-part style */
     183           0 :         if (include_minor)
     184           0 :             snprintf(buf, buflen, "%d.%d", version_number / 10000,
     185             :                      version_number % 10000);
     186             :         else
     187           0 :             snprintf(buf, buflen, "%d", version_number / 10000);
     188             :     }
     189             :     else
     190             :     {
     191             :         /* Old three-part style */
     192           0 :         if (include_minor)
     193           0 :             snprintf(buf, buflen, "%d.%d.%d", version_number / 10000,
     194           0 :                      (version_number / 100) % 100,
     195             :                      version_number % 100);
     196             :         else
     197           0 :             snprintf(buf, buflen, "%d.%d", version_number / 10000,
     198           0 :                      (version_number / 100) % 100);
     199             :     }
     200           0 :     return buf;
     201             : }
     202             : 
     203             : 
     204             : /*
     205             :  * Convert a string value to an SQL string literal and append it to
     206             :  * the given buffer.  We assume the specified client_encoding and
     207             :  * standard_conforming_strings settings.
     208             :  *
     209             :  * This is essentially equivalent to libpq's PQescapeStringInternal,
     210             :  * except for the output buffer structure.  We need it in situations
     211             :  * where we do not have a PGconn available.  Where we do,
     212             :  * appendStringLiteralConn is a better choice.
     213             :  */
     214             : void
     215        7226 : appendStringLiteral(PQExpBuffer buf, const char *str,
     216             :                     int encoding, bool std_strings)
     217             : {
     218        7226 :     size_t      length = strlen(str);
     219        7226 :     const char *source = str;
     220             :     char       *target;
     221             : 
     222        7226 :     if (!enlargePQExpBuffer(buf, 2 * length + 2))
     223           0 :         return;
     224             : 
     225        7226 :     target = buf->data + buf->len;
     226        7226 :     *target++ = '\'';
     227             : 
     228      121708 :     while (*source != '\0')
     229             :     {
     230      114482 :         char        c = *source;
     231             :         int         len;
     232             :         int         i;
     233             : 
     234             :         /* Fast path for plain ASCII */
     235      114482 :         if (!IS_HIGHBIT_SET(c))
     236             :         {
     237             :             /* Apply quoting if needed */
     238      114174 :             if (SQL_STR_DOUBLE(c, !std_strings))
     239          62 :                 *target++ = c;
     240             :             /* Copy the character */
     241      114174 :             *target++ = c;
     242      114174 :             source++;
     243      114174 :             continue;
     244             :         }
     245             : 
     246             :         /* Slow path for possible multibyte characters */
     247         308 :         len = PQmblen(source, encoding);
     248             : 
     249             :         /* Copy the character */
     250         616 :         for (i = 0; i < len; i++)
     251             :         {
     252         308 :             if (*source == '\0')
     253           0 :                 break;
     254         308 :             *target++ = *source++;
     255             :         }
     256             : 
     257             :         /*
     258             :          * If we hit premature end of string (ie, incomplete multibyte
     259             :          * character), try to pad out to the correct length with spaces. We
     260             :          * may not be able to pad completely, but we will always be able to
     261             :          * insert at least one pad space (since we'd not have quoted a
     262             :          * multibyte character).  This should be enough to make a string that
     263             :          * the server will error out on.
     264             :          */
     265         308 :         if (i < len)
     266             :         {
     267           0 :             char       *stop = buf->data + buf->maxlen - 2;
     268             : 
     269           0 :             for (; i < len; i++)
     270             :             {
     271           0 :                 if (target >= stop)
     272           0 :                     break;
     273           0 :                 *target++ = ' ';
     274             :             }
     275           0 :             break;
     276             :         }
     277             :     }
     278             : 
     279             :     /* Write the terminating quote and NUL character. */
     280        7226 :     *target++ = '\'';
     281        7226 :     *target = '\0';
     282             : 
     283        7226 :     buf->len = target - buf->data;
     284             : }
     285             : 
     286             : 
     287             : /*
     288             :  * Convert a string value to an SQL string literal and append it to
     289             :  * the given buffer.  Encoding and string syntax rules are as indicated
     290             :  * by current settings of the PGconn.
     291             :  */
     292             : void
     293        3332 : appendStringLiteralConn(PQExpBuffer buf, const char *str, PGconn *conn)
     294             : {
     295        3332 :     size_t      length = strlen(str);
     296             : 
     297             :     /*
     298             :      * XXX This is a kluge to silence escape_string_warning in our utility
     299             :      * programs.  It should go away someday.
     300             :      */
     301        3332 :     if (strchr(str, '\\') != NULL && PQserverVersion(conn) >= 80100)
     302             :     {
     303             :         /* ensure we are not adjacent to an identifier */
     304          30 :         if (buf->len > 0 && buf->data[buf->len - 1] != ' ')
     305           0 :             appendPQExpBufferChar(buf, ' ');
     306          30 :         appendPQExpBufferChar(buf, ESCAPE_STRING_SYNTAX);
     307          30 :         appendStringLiteral(buf, str, PQclientEncoding(conn), false);
     308          30 :         return;
     309             :     }
     310             :     /* XXX end kluge */
     311             : 
     312        3302 :     if (!enlargePQExpBuffer(buf, 2 * length + 2))
     313           0 :         return;
     314        3302 :     appendPQExpBufferChar(buf, '\'');
     315        3302 :     buf->len += PQescapeStringConn(conn, buf->data + buf->len,
     316             :                                    str, length, NULL);
     317        3302 :     appendPQExpBufferChar(buf, '\'');
     318             : }
     319             : 
     320             : 
     321             : /*
     322             :  * Convert a string value to a dollar quoted literal and append it to
     323             :  * the given buffer. If the dqprefix parameter is not NULL then the
     324             :  * dollar quote delimiter will begin with that (after the opening $).
     325             :  *
     326             :  * No escaping is done at all on str, in compliance with the rules
     327             :  * for parsing dollar quoted strings.  Also, we need not worry about
     328             :  * encoding issues.
     329             :  */
     330             : void
     331        1866 : appendStringLiteralDQ(PQExpBuffer buf, const char *str, const char *dqprefix)
     332             : {
     333             :     static const char suffixes[] = "_XXXXXXX";
     334        1866 :     int         nextchar = 0;
     335        1866 :     PQExpBuffer delimBuf = createPQExpBuffer();
     336             : 
     337             :     /* start with $ + dqprefix if not NULL */
     338        1866 :     appendPQExpBufferChar(delimBuf, '$');
     339        1866 :     if (dqprefix)
     340           0 :         appendPQExpBufferStr(delimBuf, dqprefix);
     341             : 
     342             :     /*
     343             :      * Make sure we choose a delimiter which (without the trailing $) is not
     344             :      * present in the string being quoted. We don't check with the trailing $
     345             :      * because a string ending in $foo must not be quoted with $foo$.
     346             :      */
     347        2448 :     while (strstr(str, delimBuf->data) != NULL)
     348             :     {
     349         582 :         appendPQExpBufferChar(delimBuf, suffixes[nextchar++]);
     350         582 :         nextchar %= sizeof(suffixes) - 1;
     351             :     }
     352             : 
     353             :     /* add trailing $ */
     354        1866 :     appendPQExpBufferChar(delimBuf, '$');
     355             : 
     356             :     /* quote it and we are all done */
     357        1866 :     appendPQExpBufferStr(buf, delimBuf->data);
     358        1866 :     appendPQExpBufferStr(buf, str);
     359        1866 :     appendPQExpBufferStr(buf, delimBuf->data);
     360             : 
     361        1866 :     destroyPQExpBuffer(delimBuf);
     362        1866 : }
     363             : 
     364             : 
     365             : /*
     366             :  * Convert a bytea value (presented as raw bytes) to an SQL string literal
     367             :  * and append it to the given buffer.  We assume the specified
     368             :  * standard_conforming_strings setting.
     369             :  *
     370             :  * This is needed in situations where we do not have a PGconn available.
     371             :  * Where we do, PQescapeByteaConn is a better choice.
     372             :  */
     373             : void
     374          48 : appendByteaLiteral(PQExpBuffer buf, const unsigned char *str, size_t length,
     375             :                    bool std_strings)
     376             : {
     377          48 :     const unsigned char *source = str;
     378             :     char       *target;
     379             : 
     380             :     static const char hextbl[] = "0123456789abcdef";
     381             : 
     382             :     /*
     383             :      * This implementation is hard-wired to produce hex-format output. We do
     384             :      * not know the server version the output will be loaded into, so making
     385             :      * an intelligent format choice is impossible.  It might be better to
     386             :      * always use the old escaped format.
     387             :      */
     388          48 :     if (!enlargePQExpBuffer(buf, 2 * length + 5))
     389           0 :         return;
     390             : 
     391          48 :     target = buf->data + buf->len;
     392          48 :     *target++ = '\'';
     393          48 :     if (!std_strings)
     394           0 :         *target++ = '\\';
     395          48 :     *target++ = '\\';
     396          48 :     *target++ = 'x';
     397             : 
     398        4176 :     while (length-- > 0)
     399             :     {
     400        4128 :         unsigned char c = *source++;
     401             : 
     402        4128 :         *target++ = hextbl[(c >> 4) & 0xF];
     403        4128 :         *target++ = hextbl[c & 0xF];
     404             :     }
     405             : 
     406             :     /* Write the terminating quote and NUL character. */
     407          48 :     *target++ = '\'';
     408          48 :     *target = '\0';
     409             : 
     410          48 :     buf->len = target - buf->data;
     411             : }
     412             : 
     413             : 
     414             : /*
     415             :  * Append the given string to the shell command being built in the buffer,
     416             :  * with shell-style quoting as needed to create exactly one argument.
     417             :  *
     418             :  * Forbid LF or CR characters, which have scant practical use beyond designing
     419             :  * security breaches.  The Windows command shell is unusable as a conduit for
     420             :  * arguments containing LF or CR characters.  A future major release should
     421             :  * reject those characters in CREATE ROLE and CREATE DATABASE, because use
     422             :  * there eventually leads to errors here.
     423             :  *
     424             :  * appendShellString() simply prints an error and dies if LF or CR appears.
     425             :  * appendShellStringNoError() omits those characters from the result, and
     426             :  * returns false if there were any.
     427             :  */
     428             : void
     429        1078 : appendShellString(PQExpBuffer buf, const char *str)
     430             : {
     431        1078 :     if (!appendShellStringNoError(buf, str))
     432             :     {
     433           2 :         fprintf(stderr,
     434           2 :                 _("shell command argument contains a newline or carriage return: \"%s\"\n"),
     435             :                 str);
     436           2 :         exit(EXIT_FAILURE);
     437             :     }
     438        1076 : }
     439             : 
     440             : bool
     441        1078 : appendShellStringNoError(PQExpBuffer buf, const char *str)
     442             : {
     443             : #ifdef WIN32
     444             :     int         backslash_run_length = 0;
     445             : #endif
     446        1078 :     bool        ok = true;
     447             :     const char *p;
     448             : 
     449             :     /*
     450             :      * Don't bother with adding quotes if the string is nonempty and clearly
     451             :      * contains only safe characters.
     452             :      */
     453        1078 :     if (*str != '\0' &&
     454        1078 :         strspn(str, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_./:") == strlen(str))
     455             :     {
     456        1008 :         appendPQExpBufferStr(buf, str);
     457        1008 :         return ok;
     458             :     }
     459             : 
     460             : #ifndef WIN32
     461          70 :     appendPQExpBufferChar(buf, '\'');
     462        3582 :     for (p = str; *p; p++)
     463             :     {
     464        3512 :         if (*p == '\n' || *p == '\r')
     465             :         {
     466           4 :             ok = false;
     467           4 :             continue;
     468             :         }
     469             : 
     470        3508 :         if (*p == '\'')
     471         100 :             appendPQExpBufferStr(buf, "'\"'\"'");
     472             :         else
     473        3408 :             appendPQExpBufferChar(buf, *p);
     474             :     }
     475          70 :     appendPQExpBufferChar(buf, '\'');
     476             : #else                           /* WIN32 */
     477             : 
     478             :     /*
     479             :      * A Windows system() argument experiences two layers of interpretation.
     480             :      * First, cmd.exe interprets the string.  Its behavior is undocumented,
     481             :      * but a caret escapes any byte except LF or CR that would otherwise have
     482             :      * special meaning.  Handling of a caret before LF or CR differs between
     483             :      * "cmd.exe /c" and other modes, and it is unusable here.
     484             :      *
     485             :      * Second, the new process parses its command line to construct argv (see
     486             :      * https://msdn.microsoft.com/en-us/library/17w5ykft.aspx).  This treats
     487             :      * backslash-double quote sequences specially.
     488             :      */
     489             :     appendPQExpBufferStr(buf, "^\"");
     490             :     for (p = str; *p; p++)
     491             :     {
     492             :         if (*p == '\n' || *p == '\r')
     493             :         {
     494             :             ok = false;
     495             :             continue;
     496             :         }
     497             : 
     498             :         /* Change N backslashes before a double quote to 2N+1 backslashes. */
     499             :         if (*p == '"')
     500             :         {
     501             :             while (backslash_run_length)
     502             :             {
     503             :                 appendPQExpBufferStr(buf, "^\\");
     504             :                 backslash_run_length--;
     505             :             }
     506             :             appendPQExpBufferStr(buf, "^\\");
     507             :         }
     508             :         else if (*p == '\\')
     509             :             backslash_run_length++;
     510             :         else
     511             :             backslash_run_length = 0;
     512             : 
     513             :         /*
     514             :          * Decline to caret-escape the most mundane characters, to ease
     515             :          * debugging and lest we approach the command length limit.
     516             :          */
     517             :         if (!((*p >= 'a' && *p <= 'z') ||
     518             :               (*p >= 'A' && *p <= 'Z') ||
     519             :               (*p >= '0' && *p <= '9')))
     520             :             appendPQExpBufferChar(buf, '^');
     521             :         appendPQExpBufferChar(buf, *p);
     522             :     }
     523             : 
     524             :     /*
     525             :      * Change N backslashes at end of argument to 2N backslashes, because they
     526             :      * precede the double quote that terminates the argument.
     527             :      */
     528             :     while (backslash_run_length)
     529             :     {
     530             :         appendPQExpBufferStr(buf, "^\\");
     531             :         backslash_run_length--;
     532             :     }
     533             :     appendPQExpBufferStr(buf, "^\"");
     534             : #endif                          /* WIN32 */
     535             : 
     536          70 :     return ok;
     537             : }
     538             : 
     539             : 
     540             : /*
     541             :  * Append the given string to the buffer, with suitable quoting for passing
     542             :  * the string as a value in a keyword/value pair in a libpq connection string.
     543             :  */
     544             : void
     545         642 : appendConnStrVal(PQExpBuffer buf, const char *str)
     546             : {
     547             :     const char *s;
     548             :     bool        needquotes;
     549             : 
     550             :     /*
     551             :      * If the string is one or more plain ASCII characters, no need to quote
     552             :      * it. This is quite conservative, but better safe than sorry.
     553             :      */
     554         642 :     needquotes = true;
     555        4700 :     for (s = str; *s; s++)
     556             :     {
     557        4302 :         if (!((*s >= 'a' && *s <= 'z') || (*s >= 'A' && *s <= 'Z') ||
     558         646 :               (*s >= '0' && *s <= '9') || *s == '_' || *s == '.'))
     559             :         {
     560         244 :             needquotes = true;
     561         244 :             break;
     562             :         }
     563        4058 :         needquotes = false;
     564             :     }
     565             : 
     566         642 :     if (needquotes)
     567             :     {
     568         244 :         appendPQExpBufferChar(buf, '\'');
     569       11232 :         while (*str)
     570             :         {
     571             :             /* ' and \ must be escaped by to \' and \\ */
     572       10988 :             if (*str == '\'' || *str == '\\')
     573         212 :                 appendPQExpBufferChar(buf, '\\');
     574             : 
     575       10988 :             appendPQExpBufferChar(buf, *str);
     576       10988 :             str++;
     577             :         }
     578         244 :         appendPQExpBufferChar(buf, '\'');
     579             :     }
     580             :     else
     581         398 :         appendPQExpBufferStr(buf, str);
     582         642 : }
     583             : 
     584             : 
     585             : /*
     586             :  * Append a psql meta-command that connects to the given database with the
     587             :  * then-current connection's user, host and port.
     588             :  */
     589             : void
     590          46 : appendPsqlMetaConnect(PQExpBuffer buf, const char *dbname)
     591             : {
     592             :     const char *s;
     593             :     bool complex;
     594             : 
     595             :     /*
     596             :      * If the name is plain ASCII characters, emit a trivial "\connect "foo"".
     597             :      * For other names, even many not technically requiring it, skip to the
     598             :      * general case.  No database has a zero-length name.
     599             :      */
     600          46 :     complex = false;
     601             : 
     602        1504 :     for (s = dbname; *s; s++)
     603             :     {
     604        1458 :         if (*s == '\n' || *s == '\r')
     605             :         {
     606           0 :             fprintf(stderr,
     607           0 :                     _("database name contains a newline or carriage return: \"%s\"\n"),
     608             :                     dbname);
     609           0 :             exit(EXIT_FAILURE);
     610             :         }
     611             : 
     612        1458 :         if (!((*s >= 'a' && *s <= 'z') || (*s >= 'A' && *s <= 'Z') ||
     613         746 :               (*s >= '0' && *s <= '9') || *s == '_' || *s == '.'))
     614             :         {
     615         654 :             complex = true;
     616             :         }
     617             :     }
     618             : 
     619          46 :     appendPQExpBufferStr(buf, "\\connect ");
     620          46 :     if (complex)
     621             :     {
     622             :         PQExpBufferData connstr;
     623             : 
     624          20 :         initPQExpBuffer(&connstr);
     625          20 :         appendPQExpBufferStr(&connstr, "dbname=");
     626          20 :         appendConnStrVal(&connstr, dbname);
     627             : 
     628          20 :         appendPQExpBufferStr(buf, "-reuse-previous=on ");
     629             : 
     630             :         /*
     631             :          * As long as the name does not contain a newline, SQL identifier
     632             :          * quoting satisfies the psql meta-command parser.  Prefer not to
     633             :          * involve psql-interpreted single quotes, which behaved differently
     634             :          * before PostgreSQL 9.2.
     635             :          */
     636          20 :         appendPQExpBufferStr(buf, fmtId(connstr.data));
     637             : 
     638          20 :         termPQExpBuffer(&connstr);
     639             :     }
     640             :     else
     641          26 :         appendPQExpBufferStr(buf, fmtId(dbname));
     642          46 :     appendPQExpBufferChar(buf, '\n');
     643          46 : }
     644             : 
     645             : 
     646             : /*
     647             :  * Deconstruct the text representation of a 1-dimensional Postgres array
     648             :  * into individual items.
     649             :  *
     650             :  * On success, returns true and sets *itemarray and *nitems to describe
     651             :  * an array of individual strings.  On parse failure, returns false;
     652             :  * *itemarray may exist or be NULL.
     653             :  *
     654             :  * NOTE: free'ing itemarray is sufficient to deallocate the working storage.
     655             :  */
     656             : bool
     657        3390 : parsePGArray(const char *atext, char ***itemarray, int *nitems)
     658             : {
     659             :     int         inputlen;
     660             :     char      **items;
     661             :     char       *strings;
     662             :     int         curitem;
     663             : 
     664             :     /*
     665             :      * We expect input in the form of "{item,item,item}" where any item is
     666             :      * either raw data, or surrounded by double quotes (in which case embedded
     667             :      * characters including backslashes and quotes are backslashed).
     668             :      *
     669             :      * We build the result as an array of pointers followed by the actual
     670             :      * string data, all in one malloc block for convenience of deallocation.
     671             :      * The worst-case storage need is not more than one pointer and one
     672             :      * character for each input character (consider "{,,,,,,,,,,}").
     673             :      */
     674        3390 :     *itemarray = NULL;
     675        3390 :     *nitems = 0;
     676        3390 :     inputlen = strlen(atext);
     677        3390 :     if (inputlen < 2 || atext[0] != '{' || atext[inputlen - 1] != '}')
     678           0 :         return false;           /* bad input */
     679        3390 :     items = (char **) malloc(inputlen * (sizeof(char *) + sizeof(char)));
     680        3390 :     if (items == NULL)
     681           0 :         return false;           /* out of memory */
     682        3390 :     *itemarray = items;
     683        3390 :     strings = (char *) (items + inputlen);
     684             : 
     685        3390 :     atext++;                    /* advance over initial '{' */
     686        3390 :     curitem = 0;
     687        6934 :     while (*atext != '}')
     688             :     {
     689        3544 :         if (*atext == '\0')
     690           0 :             return false;       /* premature end of string */
     691        3544 :         items[curitem] = strings;
     692       70712 :         while (*atext != '}' && *atext != ',')
     693             :         {
     694       67168 :             if (*atext == '\0')
     695           0 :                 return false;   /* premature end of string */
     696       67168 :             if (*atext != '"')
     697       67038 :                 *strings++ = *atext++;  /* copy unquoted data */
     698             :             else
     699             :             {
     700             :                 /* process quoted substring */
     701         130 :                 atext++;
     702        3550 :                 while (*atext != '"')
     703             :                 {
     704        3420 :                     if (*atext == '\0')
     705           0 :                         return false;   /* premature end of string */
     706        3420 :                     if (*atext == '\\')
     707             :                     {
     708         480 :                         atext++;
     709         480 :                         if (*atext == '\0')
     710           0 :                             return false;   /* premature end of string */
     711             :                     }
     712        3420 :                     *strings++ = *atext++;  /* copy quoted data */
     713             :                 }
     714         130 :                 atext++;
     715             :             }
     716             :         }
     717        3544 :         *strings++ = '\0';
     718        3544 :         if (*atext == ',')
     719         334 :             atext++;
     720        3544 :         curitem++;
     721             :     }
     722        3390 :     if (atext[1] != '\0')
     723           0 :         return false;           /* bogus syntax (embedded '}') */
     724        3390 :     *nitems = curitem;
     725        3390 :     return true;
     726             : }
     727             : 
     728             : 
     729             : /*
     730             :  * Format a reloptions array and append it to the given buffer.
     731             :  *
     732             :  * "prefix" is prepended to the option names; typically it's "" or "toast.".
     733             :  *
     734             :  * Returns false if the reloptions array could not be parsed (in which case
     735             :  * nothing will have been appended to the buffer), or true on success.
     736             :  *
     737             :  * Note: this logic should generally match the backend's flatten_reloptions()
     738             :  * (in adt/ruleutils.c).
     739             :  */
     740             : bool
     741         242 : appendReloptionsArray(PQExpBuffer buffer, const char *reloptions,
     742             :                       const char *prefix, int encoding, bool std_strings)
     743             : {
     744             :     char      **options;
     745             :     int         noptions;
     746             :     int         i;
     747             : 
     748         242 :     if (!parsePGArray(reloptions, &options, &noptions))
     749             :     {
     750           0 :         if (options)
     751           0 :             free(options);
     752           0 :         return false;
     753             :     }
     754             : 
     755         560 :     for (i = 0; i < noptions; i++)
     756             :     {
     757         318 :         char       *option = options[i];
     758             :         char       *name;
     759             :         char       *separator;
     760             :         char       *value;
     761             : 
     762             :         /*
     763             :          * Each array element should have the form name=value.  If the "=" is
     764             :          * missing for some reason, treat it like an empty value.
     765             :          */
     766         318 :         name = option;
     767         318 :         separator = strchr(option, '=');
     768         318 :         if (separator)
     769             :         {
     770         318 :             *separator = '\0';
     771         318 :             value = separator + 1;
     772             :         }
     773             :         else
     774           0 :             value = "";
     775             : 
     776         318 :         if (i > 0)
     777          76 :             appendPQExpBufferStr(buffer, ", ");
     778         318 :         appendPQExpBuffer(buffer, "%s%s=", prefix, fmtId(name));
     779             : 
     780             :         /*
     781             :          * In general we need to quote the value; but to avoid unnecessary
     782             :          * clutter, do not quote if it is an identifier that would not need
     783             :          * quoting.  (We could also allow numbers, but that is a bit trickier
     784             :          * than it looks --- for example, are leading zeroes significant?  We
     785             :          * don't want to assume very much here about what custom reloptions
     786             :          * might mean.)
     787             :          */
     788         318 :         if (strcmp(fmtId(value), value) == 0)
     789          28 :             appendPQExpBufferStr(buffer, value);
     790             :         else
     791         290 :             appendStringLiteral(buffer, value, encoding, std_strings);
     792             :     }
     793             : 
     794         242 :     if (options)
     795         242 :         free(options);
     796             : 
     797         242 :     return true;
     798             : }
     799             : 
     800             : 
     801             : /*
     802             :  * processSQLNamePattern
     803             :  *
     804             :  * Scan a wildcard-pattern string and generate appropriate WHERE clauses
     805             :  * to limit the set of objects returned.  The WHERE clauses are appended
     806             :  * to the already-partially-constructed query in buf.  Returns whether
     807             :  * any clause was added.
     808             :  *
     809             :  * conn: connection query will be sent to (consulted for escaping rules).
     810             :  * buf: output parameter.
     811             :  * pattern: user-specified pattern option, or NULL if none ("*" is implied).
     812             :  * have_where: true if caller already emitted "WHERE" (clauses will be ANDed
     813             :  * onto the existing WHERE clause).
     814             :  * force_escape: always quote regexp special characters, even outside
     815             :  * double quotes (else they are quoted only between double quotes).
     816             :  * schemavar: name of query variable to match against a schema-name pattern.
     817             :  * Can be NULL if no schema.
     818             :  * namevar: name of query variable to match against an object-name pattern.
     819             :  * altnamevar: NULL, or name of an alternative variable to match against name.
     820             :  * visibilityrule: clause to use if we want to restrict to visible objects
     821             :  * (for example, "pg_catalog.pg_table_is_visible(p.oid)").  Can be NULL.
     822             :  *
     823             :  * Formatting note: the text already present in buf should end with a newline.
     824             :  * The appended text, if any, will end with one too.
     825             :  */
     826             : bool
     827        2698 : processSQLNamePattern(PGconn *conn, PQExpBuffer buf, const char *pattern,
     828             :                       bool have_where, bool force_escape,
     829             :                       const char *schemavar, const char *namevar,
     830             :                       const char *altnamevar, const char *visibilityrule)
     831             : {
     832             :     PQExpBufferData schemabuf;
     833             :     PQExpBufferData namebuf;
     834        2698 :     bool        added_clause = false;
     835             : 
     836             : #define WHEREAND() \
     837             :     (appendPQExpBufferStr(buf, have_where ? "  AND " : "WHERE "), \
     838             :      have_where = true, added_clause = true)
     839             : 
     840        2698 :     if (pattern == NULL)
     841             :     {
     842             :         /* Default: select all visible objects */
     843         304 :         if (visibilityrule)
     844             :         {
     845          80 :             WHEREAND();
     846          80 :             appendPQExpBuffer(buf, "%s\n", visibilityrule);
     847             :         }
     848         304 :         return added_clause;
     849             :     }
     850             : 
     851        2394 :     initPQExpBuffer(&schemabuf);
     852        2394 :     initPQExpBuffer(&namebuf);
     853             : 
     854             :     /*
     855             :      * Convert shell-style 'pattern' into the regular expression(s) we want to
     856             :      * execute.  Quoting/escaping into SQL literal format will be done below
     857             :      * using appendStringLiteralConn().
     858             :      */
     859        2394 :     patternToSQLRegex(PQclientEncoding(conn), NULL, &schemabuf, &namebuf,
     860             :                       pattern, force_escape);
     861             : 
     862             :     /*
     863             :      * Now decide what we need to emit.  We may run under a hostile
     864             :      * search_path, so qualify EVERY name.  Note there will be a leading "^("
     865             :      * in the patterns in any case.
     866             :      *
     867             :      * We want the regex matches to use the database's default collation where
     868             :      * collation-sensitive behavior is required (for example, which characters
     869             :      * match '\w').  That happened by default before PG v12, but if the server
     870             :      * is >= v12 then we need to force it through explicit COLLATE clauses,
     871             :      * otherwise the "C" collation attached to "name" catalog columns wins.
     872             :      */
     873        2394 :     if (namebuf.len > 2)
     874             :     {
     875             :         /* We have a name pattern, so constrain the namevar(s) */
     876             : 
     877             :         /* Optimize away a "*" pattern */
     878        2394 :         if (strcmp(namebuf.data, "^(.*)$") != 0)
     879             :         {
     880        2326 :             WHEREAND();
     881        2326 :             if (altnamevar)
     882             :             {
     883          52 :                 appendPQExpBuffer(buf,
     884             :                                   "(%s OPERATOR(pg_catalog.~) ", namevar);
     885          52 :                 appendStringLiteralConn(buf, namebuf.data, conn);
     886          52 :                 if (PQserverVersion(conn) >= 120000)
     887          52 :                     appendPQExpBufferStr(buf, " COLLATE pg_catalog.default");
     888          52 :                 appendPQExpBuffer(buf,
     889             :                                   "\n        OR %s OPERATOR(pg_catalog.~) ",
     890             :                                   altnamevar);
     891          52 :                 appendStringLiteralConn(buf, namebuf.data, conn);
     892          52 :                 if (PQserverVersion(conn) >= 120000)
     893          52 :                     appendPQExpBufferStr(buf, " COLLATE pg_catalog.default");
     894          52 :                 appendPQExpBufferStr(buf, ")\n");
     895             :             }
     896             :             else
     897             :             {
     898        2274 :                 appendPQExpBuffer(buf, "%s OPERATOR(pg_catalog.~) ", namevar);
     899        2274 :                 appendStringLiteralConn(buf, namebuf.data, conn);
     900        2274 :                 if (PQserverVersion(conn) >= 120000)
     901        2274 :                     appendPQExpBufferStr(buf, " COLLATE pg_catalog.default");
     902        2274 :                 appendPQExpBufferChar(buf, '\n');
     903             :             }
     904             :         }
     905             :     }
     906             : 
     907        2394 :     if (schemabuf.len > 2)
     908             :     {
     909             :         /* We have a schema pattern, so constrain the schemavar */
     910             : 
     911             :         /* Optimize away a "*" pattern */
     912         350 :         if (strcmp(schemabuf.data, "^(.*)$") != 0 && schemavar)
     913             :         {
     914         350 :             WHEREAND();
     915         350 :             appendPQExpBuffer(buf, "%s OPERATOR(pg_catalog.~) ", schemavar);
     916         350 :             appendStringLiteralConn(buf, schemabuf.data, conn);
     917         350 :             if (PQserverVersion(conn) >= 120000)
     918         350 :                 appendPQExpBufferStr(buf, " COLLATE pg_catalog.default");
     919         350 :             appendPQExpBufferChar(buf, '\n');
     920             :         }
     921             :     }
     922             :     else
     923             :     {
     924             :         /* No schema pattern given, so select only visible objects */
     925        2044 :         if (visibilityrule)
     926             :         {
     927        1894 :             WHEREAND();
     928        1894 :             appendPQExpBuffer(buf, "%s\n", visibilityrule);
     929             :         }
     930             :     }
     931             : 
     932        2394 :     termPQExpBuffer(&schemabuf);
     933        2394 :     termPQExpBuffer(&namebuf);
     934             : 
     935        2394 :     return added_clause;
     936             : #undef WHEREAND
     937             : }
     938             : 
     939             : /*
     940             :  * Transform a possibly qualified shell-style object name pattern into up to
     941             :  * three SQL-style regular expressions, converting quotes, lower-casing
     942             :  * unquoted letters, and adjusting shell-style wildcard characters into regexp
     943             :  * notation.
     944             :  *
     945             :  * If the dbnamebuf and schemabuf arguments are non-NULL, and the pattern
     946             :  * contains two or more dbname/schema/name separators, we parse the portions of
     947             :  * the pattern prior to the first and second separators into dbnamebuf and
     948             :  * schemabuf, and the rest into namebuf.  (Additional dots in the name portion
     949             :  * are not treated as special.)
     950             :  *
     951             :  * If dbnamebuf is NULL and schemabuf is non-NULL, and the pattern contains at
     952             :  * least one separator, we parse the first portion into schemabuf and the rest
     953             :  * into namebuf.
     954             :  *
     955             :  * Otherwise, we parse all the pattern into namebuf.
     956             :  *
     957             :  * We surround the regexps with "^(...)$" to force them to match whole strings,
     958             :  * as per SQL practice.  We have to have parens in case strings contain "|",
     959             :  * else the "^" and "$" will be bound into the first and last alternatives
     960             :  * which is not what we want.
     961             :  *
     962             :  * The regexps we parse into the buffers are appended to the data (if any)
     963             :  * already present.  If we parse fewer fields than the number of buffers we
     964             :  * were given, the extra buffers are unaltered.
     965             :  */
     966             : void
     967        2562 : patternToSQLRegex(int encoding, PQExpBuffer dbnamebuf, PQExpBuffer schemabuf,
     968             :                   PQExpBuffer namebuf, const char *pattern, bool force_escape)
     969             : {
     970             :     PQExpBufferData buf[3];
     971             :     PQExpBuffer curbuf;
     972             :     PQExpBuffer maxbuf;
     973             :     int         i;
     974             :     bool        inquotes;
     975             :     const char *cp;
     976             : 
     977             :     Assert(pattern != NULL);
     978             :     Assert(namebuf != NULL);
     979             : 
     980             :     /* callers should never expect "dbname.relname" format */
     981             :     Assert(dbnamebuf == NULL || schemabuf != NULL);
     982             : 
     983        2562 :     inquotes = false;
     984        2562 :     cp = pattern;
     985             : 
     986        2562 :     if (dbnamebuf != NULL)
     987          70 :         maxbuf = &buf[2];
     988        2492 :     else if (schemabuf != NULL)
     989        2440 :         maxbuf = &buf[1];
     990             :     else
     991          52 :         maxbuf = &buf[0];
     992             : 
     993        2562 :     curbuf = &buf[0];
     994        2562 :     initPQExpBuffer(curbuf);
     995        2562 :     appendPQExpBufferStr(curbuf, "^(");
     996       33216 :     while (*cp)
     997             :     {
     998       30654 :         char        ch = *cp;
     999             : 
    1000       30654 :         if (ch == '"')
    1001             :         {
    1002           0 :             if (inquotes && cp[1] == '"')
    1003             :             {
    1004             :                 /* emit one quote, stay in inquotes mode */
    1005           0 :                 appendPQExpBufferChar(curbuf, '"');
    1006           0 :                 cp++;
    1007             :             }
    1008             :             else
    1009           0 :                 inquotes = !inquotes;
    1010           0 :             cp++;
    1011             :         }
    1012       30654 :         else if (!inquotes && isupper((unsigned char) ch))
    1013             :         {
    1014           0 :             appendPQExpBufferChar(curbuf,
    1015           0 :                                   pg_tolower((unsigned char) ch));
    1016           0 :             cp++;
    1017             :         }
    1018       30654 :         else if (!inquotes && ch == '*')
    1019             :         {
    1020         218 :             appendPQExpBufferStr(curbuf, ".*");
    1021         218 :             cp++;
    1022             :         }
    1023       30436 :         else if (!inquotes && ch == '?')
    1024             :         {
    1025           8 :             appendPQExpBufferChar(curbuf, '.');
    1026           8 :             cp++;
    1027             :         }
    1028             : 
    1029             :         /*
    1030             :          * When we find a dbname/schema/name separator, we treat it specially
    1031             :          * only if the caller requested more patterns to be parsed than we
    1032             :          * have already parsed from the pattern.  Otherwise, dot characters
    1033             :          * are not special.
    1034             :          */
    1035       30428 :         else if (!inquotes && ch == '.' && curbuf < maxbuf)
    1036             :         {
    1037         422 :             appendPQExpBufferStr(curbuf, ")$");
    1038         422 :             curbuf++;
    1039         422 :             initPQExpBuffer(curbuf);
    1040         422 :             appendPQExpBufferStr(curbuf, "^(");
    1041         422 :             cp++;
    1042             :         }
    1043       30006 :         else if (ch == '$')
    1044             :         {
    1045             :             /*
    1046             :              * Dollar is always quoted, whether inside quotes or not. The
    1047             :              * reason is that it's allowed in SQL identifiers, so there's a
    1048             :              * significant use-case for treating it literally, while because
    1049             :              * we anchor the pattern automatically there is no use-case for
    1050             :              * having it possess its regexp meaning.
    1051             :              */
    1052           0 :             appendPQExpBufferStr(curbuf, "\\$");
    1053           0 :             cp++;
    1054             :         }
    1055             :         else
    1056             :         {
    1057             :             /*
    1058             :              * Ordinary data character, transfer to pattern
    1059             :              *
    1060             :              * Inside double quotes, or at all times if force_escape is true,
    1061             :              * quote regexp special characters with a backslash to avoid
    1062             :              * regexp errors.  Outside quotes, however, let them pass through
    1063             :              * as-is; this lets knowledgeable users build regexp expressions
    1064             :              * that are more powerful than shell-style patterns.
    1065             :              *
    1066             :              * As an exception to that, though, always quote "[]", as that's
    1067             :              * much more likely to be an attempt to write an array type name
    1068             :              * than it is to be the start of a regexp bracket expression.
    1069             :              */
    1070       30006 :             if ((inquotes || force_escape) &&
    1071          38 :                 strchr("|*+?()[]{}.^$\\", ch))
    1072           0 :                 appendPQExpBufferChar(curbuf, '\\');
    1073       30006 :             else if (ch == '[' && cp[1] == ']')
    1074           4 :                 appendPQExpBufferChar(curbuf, '\\');
    1075       30006 :             i = PQmblenBounded(cp, encoding);
    1076       60012 :             while (i--)
    1077       30006 :                 appendPQExpBufferChar(curbuf, *cp++);
    1078             :         }
    1079             :     }
    1080        2562 :     appendPQExpBufferStr(curbuf, ")$");
    1081             : 
    1082        2562 :     appendPQExpBufferStr(namebuf, curbuf->data);
    1083        2562 :     termPQExpBuffer(curbuf);
    1084             : 
    1085        2562 :     if (curbuf > buf)
    1086             :     {
    1087         392 :         curbuf--;
    1088         392 :         appendPQExpBufferStr(schemabuf, curbuf->data);
    1089         392 :         termPQExpBuffer(curbuf);
    1090             : 
    1091         392 :         if (curbuf > buf)
    1092             :         {
    1093          30 :             curbuf--;
    1094          30 :             appendPQExpBufferStr(dbnamebuf, curbuf->data);
    1095          30 :             termPQExpBuffer(curbuf);
    1096             :         }
    1097             :     }
    1098        2562 : }

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