Re: Results from running autoupdate on gnulib m4 files

[Bruno Haible <bruno@clisp.org>]

Gavin Smith wrote:
> * AC_HEADER_STDC in realloc.m4 and malloc.m4

Fixed like this. We're assuming that <stdlib.h> exists, already since
2002-11-22.


2020-09-27  Bruno Haible  <bruno@clisp.org>

	Avoid "warning: The macro `AC_HEADER_STDC' is obsolete".
	Reported by Gavin Smith <gavinsmith0123@gmail.com> in
	<https://lists.gnu.org/archive/html/bug-gnulib/2020-09/msg00154.html>.
	Based on a patch by Paul Eggert.
	* m4/malloc.m4 (_AC_FUNC_MALLOC_IF): Don't require AC_HEADER_STDC. Don't
	test STDC_HEADERS. Assume <stdlib.h> exists.
	* m4/realloc.m4 (_AC_FUNC_REALLOC_IF): Likewise.

diff --git a/m4/malloc.m4 b/m4/malloc.m4
index c1f8ea3..3823566 100644
--- a/m4/malloc.m4
+++ b/m4/malloc.m4
@@ -1,4 +1,4 @@
-# malloc.m4 serial 20
+# malloc.m4 serial 21
 dnl Copyright (C) 2007, 2009-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,18 +8,12 @@ dnl with or without modifications, as long as this notice is preserved.
 # 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
+          [[#include <stdlib.h>
           ]],
           [[char *p = malloc (0);
             int result = !p;
diff --git a/m4/realloc.m4 b/m4/realloc.m4
index 85b8f87..53967f4 100644
--- a/m4/realloc.m4
+++ b/m4/realloc.m4
@@ -1,4 +1,4 @@
-# realloc.m4 serial 18
+# realloc.m4 serial 19
 dnl Copyright (C) 2007, 2009-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -8,18 +8,12 @@ dnl with or without modifications, as long as this notice is preserved.
 # https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=04be2b7a29d65d9a08e64e8e56e594c91749598c
 AC_DEFUN([_AC_FUNC_REALLOC_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 realloc],
     [ac_cv_func_realloc_0_nonnull],
     [AC_RUN_IFELSE(
        [AC_LANG_PROGRAM(
-          [[#if defined STDC_HEADERS || defined HAVE_STDLIB_H
-            # include <stdlib.h>
-            #else
-            char *realloc ();
-            #endif
+          [[#include <stdlib.h>
           ]],
           [[char *p = realloc (0, 0);
             int result = !p;