gnulib/import/m4/malloc.m4

   1 # malloc.m4 serial 15
   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_MALLOC_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 malloc],
  17     [ac_cv_func_malloc_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 *malloc ();
  24             #endif
  25           ]],
  26           [[char *p = malloc (0);
  27             int result = !p;
  28             free (p);
  29             return result;]])
  30        ],
  31        [ac_cv_func_malloc_0_nonnull=yes],
  32        [ac_cv_func_malloc_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_malloc_0_nonnull=yes ;;
  38           # If we don't know, assume the worst.
  39           *) ac_cv_func_malloc_0_nonnull=no ;;
  40         esac
  41        ])
  42     ])
  43   AS_IF([test $ac_cv_func_malloc_0_nonnull = yes], [$1], [$2])
  44 ])# _AC_FUNC_MALLOC_IF
  45
  46 ])
  47
  48 # gl_FUNC_MALLOC_GNU
  49 # ------------------
  50 # Test whether 'malloc (0)' is handled like in GNU libc, and replace malloc if
  51 # it is not.
  52 AC_DEFUN([gl_FUNC_MALLOC_GNU],
  53 [
  54   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
  55   dnl _AC_FUNC_MALLOC_IF is defined in Autoconf.
  56   _AC_FUNC_MALLOC_IF(
  57     [AC_DEFINE([HAVE_MALLOC_GNU], [1],
  58                [Define to 1 if your system has a GNU libc compatible 'malloc'
  59                 function, and to 0 otherwise.])],
  60     [AC_DEFINE([HAVE_MALLOC_GNU], [0])
  61      REPLACE_MALLOC=1
  62     ])
  63 ])
  64
  65 # gl_FUNC_MALLOC_POSIX
  66 # --------------------
  67 # Test whether 'malloc' is POSIX compliant (sets errno to ENOMEM when it
  68 # fails), and replace malloc if it is not.
  69 AC_DEFUN([gl_FUNC_MALLOC_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_MALLOC_POSIX], [1],
  75       [Define if the 'malloc' function is POSIX compliant.])
  76   else
  77     REPLACE_MALLOC=1
  78   fi
  79 ])
  80
  81 # Test whether malloc, realloc, calloc are POSIX compliant,
  82 # Set gl_cv_func_malloc_posix to yes or no accordingly.
  83 AC_DEFUN([gl_CHECK_MALLOC_POSIX],
  84 [
  85   AC_CACHE_CHECK([whether malloc, realloc, calloc are POSIX compliant],
  86     [gl_cv_func_malloc_posix],
  87     [
  88       dnl It is too dangerous to try to allocate a large amount of memory:
  89       dnl some systems go to their knees when you do that. So assume that
  90       dnl all Unix implementations of the function are POSIX compliant.
  91       AC_COMPILE_IFELSE(
  92         [AC_LANG_PROGRAM(
  93            [[]],
  94            [[#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
  95              choke me
  96              #endif
  97             ]])],
  98         [gl_cv_func_malloc_posix=yes],
  99         [gl_cv_func_malloc_posix=no])
 100     ])
 101 ])