gnulib/import/m4/strtok_r.m4

   1 # strtok_r.m4 serial 13
   2 dnl Copyright (C) 2002-2004, 2006-2007, 2009-2016 Free Software Foundation,
   3 dnl Inc.
   4 dnl This file is free software; the Free Software Foundation
   5 dnl gives unlimited permission to copy and/or distribute it,
   6 dnl with or without modifications, as long as this notice is preserved.
   7
   8 AC_DEFUN([gl_FUNC_STRTOK_R],
   9 [
  10   dnl The strtok_r() declaration in lib/string.in.h uses 'restrict'.
  11   AC_REQUIRE([AC_C_RESTRICT])
  12
  13   AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
  14   AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  15   AC_CHECK_FUNCS([strtok_r])
  16   if test $ac_cv_func_strtok_r = yes; then
  17     HAVE_STRTOK_R=1
  18     dnl glibc 2.7 has a bug in strtok_r that causes a segmentation fault
  19     dnl when the second argument to strtok_r is a constant string that has
  20     dnl exactly one byte and compiling with optimization.  This bug is, for
  21     dnl example, present in the glibc 2.7-18 package in Debian "lenny".
  22     dnl See <http://sources.redhat.com/bugzilla/show_bug.cgi?id=5614>.
  23     AC_CACHE_CHECK([whether strtok_r works], [gl_cv_func_strtok_r_works],
  24       [AC_RUN_IFELSE(
  25          [AC_LANG_PROGRAM([[
  26               #ifndef __OPTIMIZE__
  27               # define __OPTIMIZE__ 1
  28               #endif
  29               #undef __OPTIMIZE_SIZE__
  30               #undef __NO_INLINE__
  31               #include <stdlib.h>
  32               #include <string.h>
  33             ]],
  34             [[static const char dummy[] = "\177\01a";
  35               char delimiters[] = "xxxxxxxx";
  36               char *save_ptr = (char *) dummy;
  37               strtok_r (delimiters, "x", &save_ptr);
  38               strtok_r (NULL, "x", &save_ptr);
  39               return 0;
  40             ]])
  41          ],
  42          [gl_cv_func_strtok_r_works=yes],
  43          [gl_cv_func_strtok_r_works=no],
  44          [
  45 changequote(,)dnl
  46           case "$host_os" in
  47                     # Guess no on glibc systems.
  48             *-gnu*) gl_cv_func_strtok_r_works="guessing no";;
  49             *)      gl_cv_func_strtok_r_works="guessing yes";;
  50           esac
  51 changequote([,])dnl
  52          ])
  53       ])
  54     case "$gl_cv_func_strtok_r_works" in
  55       *no)
  56         dnl We could set REPLACE_STRTOK_R=1 here, but it's only the macro
  57         dnl version in <bits/string2.h> which is wrong. The code compiled
  58         dnl into libc is fine.
  59         UNDEFINE_STRTOK_R=1
  60         ;;
  61     esac
  62   else
  63     HAVE_STRTOK_R=0
  64   fi
  65   AC_CHECK_DECLS_ONCE([strtok_r])
  66   if test $ac_cv_have_decl_strtok_r = no; then
  67     HAVE_DECL_STRTOK_R=0
  68   fi
  69 ])
  70
  71 # Prerequisites of lib/strtok_r.c.
  72 AC_DEFUN([gl_PREREQ_STRTOK_R], [
  73   :
  74 ])