1# realloc.m4 serial 14
2dnl Copyright (C) 2007, 2009-2017 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7m4_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
11AC_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.
52AC_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.
69AC_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])
80