string/rawmemchr.c

   1 /* Copyright (C) 1991-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 #include <string.h>
  19 #include <libc-diag.h>
  20
  21 #ifndef RAWMEMCHR
  22 # define RAWMEMCHR __rawmemchr
  23 #endif
  24
  25 /* Find the first occurrence of C in S.  */
  26 void *
  27 RAWMEMCHR (const void *s, int c)
  28 {
  29   DIAG_PUSH_NEEDS_COMMENT;
  30 #if __GNUC_PREREQ (7, 0)
  31   /* GCC 8 warns about the size passed to memchr being larger than
  32      PTRDIFF_MAX; the use of SIZE_MAX is deliberate here.  */
  33   DIAG_IGNORE_NEEDS_COMMENT (8, "-Wstringop-overflow=");
  34 #endif
  35 #if __GNUC_PREREQ (11, 0)
  36   /* Likewise GCC 11, with a different warning option.  */
  37   DIAG_IGNORE_NEEDS_COMMENT (11, "-Wstringop-overread");
  38 #endif
  39   if (c != '\0')
  40     return memchr (s, c, (size_t)-1);
  41   DIAG_POP_NEEDS_COMMENT;
  42   return (char *)s + strlen (s);
  43 }
  44 libc_hidden_def (__rawmemchr)
  45 weak_alias (__rawmemchr, rawmemchr)