1# malloc.m4 serial 21
2dnl Copyright (C) 2007, 2009-2020 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
7# This is adapted with modifications from upstream Autoconf here:
8# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=04be2b7a29d65d9a08e64e8e56e594c91749598c
9AC_DEFUN([_AC_FUNC_MALLOC_IF],
10[
11  AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles
12  AC_CACHE_CHECK([for GNU libc compatible malloc],
13    [ac_cv_func_malloc_0_nonnull],
14    [AC_RUN_IFELSE(
15       [AC_LANG_PROGRAM(
16          [[#include <stdlib.h>
17          ]],
18          [[char *p = malloc (0);
19            int result = !p;
20            free (p);
21            return result;]])
22       ],
23       [ac_cv_func_malloc_0_nonnull=yes],
24       [ac_cv_func_malloc_0_nonnull=no],
25       [case "$host_os" in
26          # Guess yes on platforms where we know the result.
27          *-gnu* | gnu* | *-musl* | freebsd* | netbsd* | openbsd* \
28          | hpux* | solaris* | cygwin* | mingw*)
29            ac_cv_func_malloc_0_nonnull="guessing yes" ;;
30          # If we don't know, obey --enable-cross-guesses.
31          *) ac_cv_func_malloc_0_nonnull="$gl_cross_guess_normal" ;;
32        esac
33       ])
34    ])
35  case "$ac_cv_func_malloc_0_nonnull" in
36    *yes)
37      $1
38      ;;
39    *)
40      $2
41      ;;
42  esac
43])# _AC_FUNC_MALLOC_IF
44
45# gl_FUNC_MALLOC_GNU
46# ------------------
47# Test whether 'malloc (0)' is handled like in GNU libc, and replace malloc if
48# it is not.
49AC_DEFUN([gl_FUNC_MALLOC_GNU],
50[
51  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
52  dnl _AC_FUNC_MALLOC_IF is defined in Autoconf.
53  _AC_FUNC_MALLOC_IF(
54    [AC_DEFINE([HAVE_MALLOC_GNU], [1],
55               [Define to 1 if your system has a GNU libc compatible 'malloc'
56                function, and to 0 otherwise.])],
57    [AC_DEFINE([HAVE_MALLOC_GNU], [0])
58     REPLACE_MALLOC=1
59    ])
60])
61
62# gl_FUNC_MALLOC_POSIX
63# --------------------
64# Test whether 'malloc' is POSIX compliant (sets errno to ENOMEM when it
65# fails), and replace malloc if it is not.
66AC_DEFUN([gl_FUNC_MALLOC_POSIX],
67[
68  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
69  AC_REQUIRE([gl_CHECK_MALLOC_POSIX])
70  if test $gl_cv_func_malloc_posix = yes; then
71    AC_DEFINE([HAVE_MALLOC_POSIX], [1],
72      [Define if the 'malloc' function is POSIX compliant.])
73  else
74    REPLACE_MALLOC=1
75  fi
76])
77
78# Test whether malloc, realloc, calloc are POSIX compliant,
79# Set gl_cv_func_malloc_posix to yes or no accordingly.
80AC_DEFUN([gl_CHECK_MALLOC_POSIX],
81[
82  AC_CACHE_CHECK([whether malloc, realloc, calloc are POSIX compliant],
83    [gl_cv_func_malloc_posix],
84    [
85      dnl It is too dangerous to try to allocate a large amount of memory:
86      dnl some systems go to their knees when you do that. So assume that
87      dnl all Unix implementations of the function are POSIX compliant.
88      AC_COMPILE_IFELSE(
89        [AC_LANG_PROGRAM(
90           [[]],
91           [[#if defined _WIN32 && ! defined __CYGWIN__
92             choke me
93             #endif
94            ]])],
95        [gl_cv_func_malloc_posix=yes],
96        [gl_cv_func_malloc_posix=no])
97    ])
98])
99