1 files changed, 98 insertions, 41 deletions

diff --git a/gl/m4/malloc.m4 b/gl/m4/malloc.m4
index 55402924..547b4e4d 100644
--- a/gl/m4/malloc.m4
+++ b/gl/m4/malloc.m4
@@ -1,11 +1,24 @@
-# malloc.m4 serial 28
-dnl Copyright (C) 2007, 2009-2023 Free Software Foundation, Inc.
+# malloc.m4
+# serial 43.1
+dnl Copyright (C) 2007, 2009-2025 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.
+dnl This file is offered as-is, without any warranty.
 
-# This is adapted with modifications from upstream Autoconf here:
-# https://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/functions.m4?id=v2.70#n949
+m4_version_prereq([2.73], [], [
+# Modules that use this macro directly or indirectly should depend
+# on extensions-aix, so that _LINUX_SOURCE_COMPAT gets defined
+# before this macro gets invoked.  This helps on AIX 7.2 and earlier
+# if !(__VEC__ || __AIXVEC), and doesn't hurt otherwise.
+#
+# This is copied from upstream Autoconf here:
+# https://git.savannah.gnu.org/cgit/autoconf.git/tree/lib/autoconf/functions.m4?id=1f38316f6af7bf63e5e7dd187ff6456e07ad743e#n971
+# _AC_FUNC_MALLOC_IF(IF-WORKS, IF-NOT[, UNKNOWN-ASSUME])
+# ------------------------------------------------------
+# If 'malloc (0)' returns nonnull, run IF-WORKS, otherwise, IF-NOT.
+# If it is not known whether it works, assume the shell word UNKNOWN-ASSUME,
+# which should end in "yes" or in something else (the latter is the default).
 AC_DEFUN([_AC_FUNC_MALLOC_IF],
 [
   AC_REQUIRE([AC_CANONICAL_HOST])dnl for cross-compiles
@@ -14,55 +27,81 @@ AC_DEFUN([_AC_FUNC_MALLOC_IF],
     [AC_RUN_IFELSE(
        [AC_LANG_PROGRAM(
           [[#include <stdlib.h>
-          ]],
-          [[void *p = malloc (0);
+            /* Use pmalloc to test; 'volatile' prevents the compiler
+               from optimizing the malloc call away.  */
+            void *(*volatile pmalloc) (size_t) = malloc;]],
+          [[void *p = pmalloc (0);
             int result = !p;
             free (p);
-            return result;]])
-       ],
+            return result;]])],
        [ac_cv_func_malloc_0_nonnull=yes],
        [ac_cv_func_malloc_0_nonnull=no],
-       [case "$host_os" in
-          # Guess yes on platforms where we know the result.
-          *-gnu* | freebsd* | netbsd* | openbsd* | bitrig* \
-          | gnu* | *-musl* | midnightbsd* \
-          | hpux* | solaris* | cygwin* | mingw* | msys* )
-            ac_cv_func_malloc_0_nonnull="guessing yes" ;;
-          # If we don't know, obey --enable-cross-guesses.
-          *) ac_cv_func_malloc_0_nonnull="$gl_cross_guess_normal" ;;
-        esac
-       ])
-    ])
+       [AS_CASE([$host_os],
+          [# Guess yes on platforms where we know the result.
+           *-gnu* | freebsd* | netbsd* | openbsd* | bitrig* \
+           | gnu* | *-musl* | midipix* | midnightbsd* \
+           | hpux* | solaris* | cygwin* | mingw* | windows* | msys*],
+            [ac_cv_func_malloc_0_nonnull="guessing yes"],
+          [# Guess as follows if we don't know.
+           ac_cv_func_malloc_0_nonnull=m4_default([$3], ["guessing no"])])])])
   AS_CASE([$ac_cv_func_malloc_0_nonnull], [*yes], [$1], [$2])
 ])# _AC_FUNC_MALLOC_IF
+])
+
+# gl_FUNC_MALLOC_0_NONNULL
+# ------------------------
+# If 'malloc (0)' returns nonnull define HAVE_MALLOC_0_NONNULL.
+# Also, set ac_cv_func_malloc_0_nonnull to a string that ends in
+# "yes", otherwise set it to something else.  If unknown whether
+# malloc (0) works, guess as normal for cross-builds.
+AC_DEFUN([gl_FUNC_MALLOC_0_NONNULL],
+[
+  _AC_FUNC_MALLOC_IF(
+    [AC_DEFINE([HAVE_MALLOC_0_NONNULL], [1],
+       [Define to 1 if malloc (0) returns nonnull.])],
+    [],
+    ["$gl_cross_guess_normal"])
+])
 
 # gl_FUNC_MALLOC_GNU
 # ------------------
-# Replace malloc if it is not compatible with GNU libc.
+# Test whether malloc (0) is compatible with GNU libc.
+# Replace malloc if not.
+# Define HAVE_MALLOC_0_NONNULL if malloc (0) returns nonnull (except upon
+# out-of-memory).
+# Define HAVE_MALLOC_PTRDIFF if malloc (N) reliably fails when N exceeds
+# PTRDIFF_MAX.
 AC_DEFUN([gl_FUNC_MALLOC_GNU],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_MALLOC_POSIX])
-  REPLACE_MALLOC_FOR_MALLOC_GNU="$REPLACE_MALLOC_FOR_MALLOC_POSIX"
-  if test $REPLACE_MALLOC_FOR_MALLOC_GNU = 0; then
-    _AC_FUNC_MALLOC_IF([], [REPLACE_MALLOC_FOR_MALLOC_GNU=1])
-  fi
+  AC_REQUIRE([gl_FUNC_MALLOC_0_NONNULL])
+
+  AS_CASE([$ac_cv_func_malloc_0_nonnull],
+    [*yes],
+      [REPLACE_MALLOC_FOR_MALLOC_GNU=$REPLACE_MALLOC_FOR_MALLOC_POSIX],
+    [REPLACE_MALLOC_FOR_MALLOC_GNU=1])
 ])
 
 # gl_FUNC_MALLOC_PTRDIFF
 # ----------------------
-# Test whether malloc (N) reliably fails when N exceeds PTRDIFF_MAX,
-# and replace malloc otherwise.
+# Test whether malloc (N) reliably fails when N exceeds PTRDIFF_MAX.
+# Define HAVE_MALLOC_PTRDIFF if yes.
+# Replace malloc if not.
 AC_DEFUN([gl_FUNC_MALLOC_PTRDIFF],
 [
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
   AC_REQUIRE([gl_CHECK_MALLOC_PTRDIFF])
-  test "$gl_cv_malloc_ptrdiff" = yes || REPLACE_MALLOC_FOR_MALLOC_POSIX=1
+  AS_IF([test "$gl_cv_malloc_ptrdiff" = yes],
+    [AC_DEFINE([HAVE_MALLOC_PTRDIFF], 1,
+       [Define to 1 if malloc-like functions do not allocate objects
+        larger than PTRDIFF_MAX bytes.])],
+    [REPLACE_MALLOC_FOR_MALLOC_POSIX=1])
 ])
 
-# Test whether malloc, realloc, calloc refuse to create objects
+# Test whether malloc, calloc refuse to create objects
 # larger than what can be expressed in ptrdiff_t.
-# Set gl_cv_func_malloc_gnu to yes or no accordingly.
+# Set gl_cv_func_malloc_gnu.
 AC_DEFUN([gl_CHECK_MALLOC_PTRDIFF],
 [
   AC_CACHE_CHECK([whether malloc is ptrdiff_t safe],
@@ -106,30 +145,48 @@ AC_DEFUN([gl_FUNC_MALLOC_POSIX],
   AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
   AC_REQUIRE([gl_FUNC_MALLOC_PTRDIFF])
   AC_REQUIRE([gl_CHECK_MALLOC_POSIX])
-  if test "$gl_cv_func_malloc_posix" = yes; then
-    AC_DEFINE([HAVE_MALLOC_POSIX], [1],
-      [Define if malloc, realloc, and calloc set errno on allocation failure.])
-  else
-    REPLACE_MALLOC_FOR_MALLOC_POSIX=1
-  fi
+  case "$gl_cv_func_malloc_posix" in
+    *yes)
+      AC_DEFINE([HAVE_MALLOC_POSIX], [1],
+        [Define if malloc and calloc set errno on allocation failure.])
+      ;;
+    *)
+      REPLACE_MALLOC_FOR_MALLOC_POSIX=1
+      ;;
+  esac
 ])
 
-# Test whether malloc, realloc, calloc set errno to ENOMEM on failure.
-# Set gl_cv_func_malloc_posix to yes or no accordingly.
+# Test whether malloc, calloc set errno to ENOMEM on failure.
+# Set gl_cv_func_malloc_posix to *yes or *no accordingly.
 AC_DEFUN([gl_CHECK_MALLOC_POSIX],
 [
   AC_REQUIRE([AC_CANONICAL_HOST])
-  AC_CACHE_CHECK([whether malloc, realloc, calloc set errno on failure],
+  AC_CACHE_CHECK([whether malloc, calloc set errno on failure],
     [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 set errno on failure,
       dnl except on those platforms where we have seen 'test-malloc-gnu',
-      dnl 'test-realloc-gnu', 'test-calloc-gnu' fail.
+      dnl 'test-realloc-posix', 'test-calloc-gnu' fail. For platforms
+      dnl where only 'test-realloc-posix', see realloc.m4.
       case "$host_os" in
-        mingw*)
-          gl_cv_func_malloc_posix=no ;;
+        mingw* | windows*)
+          dnl Old MSVCRT from 2001 did not set errno=ENOMEM when malloc failed.
+          dnl More recent MSVCRT from 2019 does so.
+          dnl UCRT is the successor of MSVCRT. Assume that UCRT does so as well.
+          AC_COMPILE_IFELSE(
+            [AC_LANG_PROGRAM(
+              [[#include <stdio.h>
+                #ifndef _UCRT
+                msvcrt yuck
+                #endif
+              ]],
+              [[]])
+            ],
+            [gl_cv_func_malloc_posix="guessing yes"],
+            [gl_cv_func_malloc_posix="guessing no"])
+          ;;
         irix* | solaris*)
           dnl On IRIX 6.5, the three functions return NULL with errno unset
           dnl when the argument is larger than PTRDIFF_MAX.