1 files changed, 101 insertions, 0 deletions
diff --git a/m4/malloc.m4 b/m4/malloc.m4
new file mode 100644
index 0000000..4c182b4
--- /dev/null
+++ b/m4/malloc.m4
@@ -0,0 +1,101 @@
+# malloc.m4 serial 17
+dnl Copyright (C) 2007, 2009-2018 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* | freebsd* | netbsd* | openbsd* \
+          | hpux* | solaris* | cygwin* | mingw*)
+            ac_cv_func_malloc_0_nonnull=yes ;;
+          # If we don't know, assume the worst.
+          *) ac_cv_func_malloc_0_nonnull=no ;;
+        esac
+       ])
+    ])
+  AS_IF([test $ac_cv_func_malloc_0_nonnull = yes], [$1], [$2])
+])# _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])
+    ])
+])