gnulib/import/m4/realloc.m4

   1 # realloc.m4 serial 14
   2 dnl Copyright (C) 2007, 2009-2016 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 m4_version_prereq([2.70], [] ,[
   8
   9 # This is adapted with modifications from upstream Autoconf here:
  10 # http://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=04be2b7a29d65d9a08e64e8e56e594c91749598c
  11 AC_DEFUN([_AC_FUNC_REALLOC_IF],
  12 [
  13   AC_REQUIRE([AC_HEADER_STDC])dnl
  14   AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles
  15   AC_CHECK_HEADERS([stdlib.h])
  16   AC_CACHE_CHECK([for GNU libc compatible realloc],
  17     [ac_cv_func_realloc_0_nonnull],
  18     [AC_RUN_IFELSE(
  19        [AC_LANG_PROGRAM(
  20           [[#if defined STDC_HEADERS || defined HAVE_STDLIB_H
  21             # include <stdlib.h>
  22             #else
  23             char *realloc ();
  24             #endif
  25           ]],
  26           [[char *p = realloc (0, 0);
  27             int result = !p;
  28             free (p);
  29             return result;]])
  30        ],
  31        [ac_cv_func_realloc_0_nonnull=yes],
  32        [ac_cv_func_realloc_0_nonnull=no],
  33        [case "$host_os" in
  34           # Guess yes on platforms where we know the result.
  35           *-gnu* | freebsd* | netbsd* | openbsd* \
  36           | hpux* | solaris* | cygwin* | mingw*)
  37             ac_cv_func_realloc_0_nonnull=yes ;;
  38           # If we don't know, assume the worst.
  39           *) ac_cv_func_realloc_0_nonnull=no ;;
  40         esac
  41        ])
  42     ])
  43   AS_IF([test $ac_cv_func_realloc_0_nonnull = yes], [$1], [$2])
  44 ])# AC_FUNC_REALLOC
  45
  46 ])
  47
  48 # gl_FUNC_REALLOC_GNU
  49 # -------------------
  50 # Test whether 'realloc (0, 0)' is handled like in GNU libc, and replace
  51 # realloc if it is not.
  52 AC_DEFUN([gl_FUNC_REALLOC_GNU],
  53 [
  54   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  55   dnl _AC_FUNC_REALLOC_IF is defined in Autoconf.
  56   _AC_FUNC_REALLOC_IF(
  57     [AC_DEFINE([HAVE_REALLOC_GNU], [1],
  58                [Define to 1 if your system has a GNU libc compatible 'realloc'
  59                 function, and to 0 otherwise.])],
  60     [AC_DEFINE([HAVE_REALLOC_GNU], [0])
  61      REPLACE_REALLOC=1
  62     ])
  63 ])# gl_FUNC_REALLOC_GNU
  64
  65 # gl_FUNC_REALLOC_POSIX
  66 # ---------------------
  67 # Test whether 'realloc' is POSIX compliant (sets errno to ENOMEM when it
  68 # fails), and replace realloc if it is not.
  69 AC_DEFUN([gl_FUNC_REALLOC_POSIX],
  70 [
  71   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  72   AC_REQUIRE([gl_CHECK_MALLOC_POSIX])
  73   if test $gl_cv_func_malloc_posix = yes; then
  74     AC_DEFINE([HAVE_REALLOC_POSIX], [1],
  75       [Define if the 'realloc' function is POSIX compliant.])
  76   else
  77     REPLACE_REALLOC=1
  78   fi
  79 ])