misc/regexp.c

   1 /* Compatibility symbols for the obsolete <regexp.h> interface.
   2    Copyright (C) 1996-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* regexp.h now contains only an #error directive, so it cannot be
  20    used in this file.
  21
  22    The function that would produce an 'expbuf' to use as the second
  23    argument to 'step' and 'advance' was defined only in regexp.h,
  24    as its definition depended on macros defined by the user.  */
  25
  26 #include <regex.h>
  27 #include <shlib-compat.h>
  28
  29 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
  30
  31 /* Define the variables used for the interface.  */
  32 char *loc1;
  33 char *loc2;
  34 compat_symbol (libc, loc1, loc1, GLIBC_2_0);
  35 compat_symbol (libc, loc2, loc2, GLIBC_2_0);
  36
  37 /* Although we do not support the use we define this variable as well.  */
  38 char *locs;
  39 compat_symbol (libc, locs, locs, GLIBC_2_0);
  40
  41
  42 /* Find the next match in STRING.  The compiled regular expression is
  43    found in the buffer starting at EXPBUF.  `loc1' will return the
  44    first character matched and `loc2' points to the next unmatched
  45    character.  */
  46 int
  47 weak_function attribute_compat_text_section
  48 step (const char *string, const char *expbuf)
  49 {
  50   regmatch_t match;     /* We only need info about the full match.  */
  51
  52   expbuf += __alignof (regex_t *);
  53   expbuf -= (expbuf - ((const char *) 0)) % __alignof__ (regex_t *);
  54
  55   if (__regexec ((const regex_t *) expbuf, string, 1, &match, REG_NOTEOL)
  56       == REG_NOMATCH)
  57     return 0;
  58
  59   loc1 = (char *) string + match.rm_so;
  60   loc2 = (char *) string + match.rm_eo;
  61   return 1;
  62 }
  63 compat_symbol (libc, step, step, GLIBC_2_0);
  64
  65
  66 /* Match the beginning of STRING with the compiled regular expression
  67    in EXPBUF.  If the match is successful `loc2' will contain the
  68    position of the first unmatched character.  */
  69 int
  70 weak_function attribute_compat_text_section
  71 advance (const char *string, const char *expbuf)
  72 {
  73   regmatch_t match;     /* We only need info about the full match.  */
  74
  75   expbuf += __alignof__ (regex_t *);
  76   expbuf -= (expbuf - ((const char *) 0)) % __alignof__ (regex_t *);
  77
  78   if (__regexec ((const regex_t *) expbuf, string, 1, &match, REG_NOTEOL)
  79       == REG_NOMATCH
  80       /* We have to check whether the check is at the beginning of the
  81          buffer.  */
  82       || match.rm_so != 0)
  83     return 0;
  84
  85   loc2 = (char *) string + match.rm_eo;
  86   return 1;
  87 }
  88 compat_symbol (libc, advance, advance, GLIBC_2_0);
  89
  90
  91 #endif /* SHLIB_COMPAT (2.0, 2.23) */