wget/m4/malloc.m4

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# malloc.m4 serial 19
dnl Copyright (C) 2007, 2009-2019 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
m4_version_prereq([2.70], [] ,[
# This is adapted with modifications from upstream Autoconf here:
# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=04be2b7a29d65d9a08e64e8e56e594c91749598c
AC_DEFUN([_AC_FUNC_MALLOC_IF],
[
AC_REQUIRE([AC_HEADER_STDC])dnl
AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles
AC_CHECK_HEADERS([stdlib.h])
AC_CACHE_CHECK([for GNU libc compatible malloc],
[ac_cv_func_malloc_0_nonnull],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[[#if defined STDC_HEADERS || defined HAVE_STDLIB_H
# include <stdlib.h>
#else
char *malloc ();
#endif
]],
[[char *p = malloc (0);
int result = !p;
free (p);
return result;]])
],
[ac_cv_func_malloc_0_nonnull=yes],
[ac_cv_func_malloc_0_nonnull=no],
[case "$host_os" in
# Guess yes on platforms where we know the result.
*-gnu* | gnu* | *-musl* | freebsd* | netbsd* | openbsd* \
| hpux* | solaris* | cygwin* | mingw*)
ac_cv_func_malloc_0_nonnull="guessing yes" ;;
# If we don't know, assume the worst.
*) ac_cv_func_malloc_0_nonnull="guessing no" ;;
esac
])
])
case "$ac_cv_func_malloc_0_nonnull" in
*yes)
$1
;;
*)
$2
;;
esac
])# _AC_FUNC_MALLOC_IF
])
# gl_FUNC_MALLOC_GNU
# ------------------
# Test whether 'malloc (0)' is handled like in GNU libc, and replace malloc if
# it is not.
AC_DEFUN([gl_FUNC_MALLOC_GNU],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
dnl _AC_FUNC_MALLOC_IF is defined in Autoconf.
_AC_FUNC_MALLOC_IF(
[AC_DEFINE([HAVE_MALLOC_GNU], [1],
[Define to 1 if your system has a GNU libc compatible 'malloc'
function, and to 0 otherwise.])],
[AC_DEFINE([HAVE_MALLOC_GNU], [0])
REPLACE_MALLOC=1
])
])
# gl_FUNC_MALLOC_POSIX
# --------------------
# Test whether 'malloc' is POSIX compliant (sets errno to ENOMEM when it
# fails), and replace malloc if it is not.
AC_DEFUN([gl_FUNC_MALLOC_POSIX],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
AC_REQUIRE([gl_CHECK_MALLOC_POSIX])
if test $gl_cv_func_malloc_posix = yes; then
AC_DEFINE([HAVE_MALLOC_POSIX], [1],
[Define if the 'malloc' function is POSIX compliant.])
else
REPLACE_MALLOC=1
fi
])
# Test whether malloc, realloc, calloc are POSIX compliant,
# Set gl_cv_func_malloc_posix to yes or no accordingly.
AC_DEFUN([gl_CHECK_MALLOC_POSIX],
[
AC_CACHE_CHECK([whether malloc, realloc, calloc are POSIX compliant],
[gl_cv_func_malloc_posix],
[
dnl It is too dangerous to try to allocate a large amount of memory:
dnl some systems go to their knees when you do that. So assume that
dnl all Unix implementations of the function are POSIX compliant.
AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[]],
[[#if defined _WIN32 && ! defined __CYGWIN__
choke me
#endif
]])],
[gl_cv_func_malloc_posix=yes],
[gl_cv_func_malloc_posix=no])
])
])