If someone ever needs to distinguish between GNU and merely POSIX
behavior we can split this into two modules, but for now just
make this module act like GNU.
* lib/aligned_alloc.c (aligned_alloc): Treat zero size like GNU.
* m4/aligned_alloc.m4 (gl_FUNC_ALIGNED_ALLOC):
* tests/test-aligned_alloc.c (main):
Test zero size too.
---
ChangeLog | 11 +++++++++++
doc/posix-functions/aligned_alloc.texi | 4 ++++
lib/aligned_alloc.c | 2 ++
m4/aligned_alloc.m4 | 15 ++++++++++-----
tests/test-aligned_alloc.c | 5 ++++-
5 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 83143af50f..61296ba779 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2024-10-30 Paul Eggert <egg...@cs.ucla.edu>
+
+ aligned_alloc: check for GNU behavior with size 0
+ If someone ever needs to distinguish between GNU and merely POSIX
+ behavior we can split this into two modules, but for now just
+ make this module act like GNU.
+ * lib/aligned_alloc.c (aligned_alloc): Treat zero size like GNU.
+ * m4/aligned_alloc.m4 (gl_FUNC_ALIGNED_ALLOC):
+ * tests/test-aligned_alloc.c (main):
+ Test zero size too.
+
2024-10-30 Bruno Haible <br...@clisp.org>
assert-h, stdbool: Fix compilation error with MSVC 14 (regr. yesterday).
diff --git a/doc/posix-functions/aligned_alloc.texi
b/doc/posix-functions/aligned_alloc.texi
index d7830e39ac..b815bd0532 100644
--- a/doc/posix-functions/aligned_alloc.texi
+++ b/doc/posix-functions/aligned_alloc.texi
@@ -17,6 +17,10 @@ Portability problems fixed by Gnulib:
This function fails if the alignment argument is smaller than
@code{sizeof (void *)} on some platforms:
macOS 14, AIX 7.3.1.
+
+@item
+This function returns a null pointer if the size argument is zero:
+AIX 7.3.
@end itemize
Portability problems not fixed by Gnulib:
diff --git a/lib/aligned_alloc.c b/lib/aligned_alloc.c
index 46c44a5b50..947ec1257c 100644
--- a/lib/aligned_alloc.c
+++ b/lib/aligned_alloc.c
@@ -23,6 +23,8 @@ void *
aligned_alloc (size_t alignment, size_t size)
#undef aligned_alloc
{
+ if (size == 0)
+ size = 1;
if (alignment >= sizeof (void *))
return aligned_alloc (alignment, size);
else
diff --git a/m4/aligned_alloc.m4 b/m4/aligned_alloc.m4
index d7dc2450ca..1311ea3c97 100644
--- a/m4/aligned_alloc.m4
+++ b/m4/aligned_alloc.m4
@@ -1,5 +1,5 @@
# aligned_alloc.m4
-# serial 6
+# serial 7
dnl Copyright (C) 2020-2024 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -18,14 +18,19 @@ AC_DEFUN([gl_FUNC_ALIGNED_ALLOC],
if test $ac_cv_func_aligned_alloc = yes; then
dnl On macOS 11.1 and AIX 7.3.1, aligned_alloc returns NULL when the
dnl alignment argument is smaller than sizeof (void *).
- AC_CACHE_CHECK([whether aligned_alloc works for small alignments],
+ dnl On AIX 7.3, aligned_alloc with a zero size returns NULL.
+ AC_CACHE_CHECK([whether aligned_alloc works for small alignments and
sizes],
[gl_cv_func_aligned_alloc_works],
[AC_RUN_IFELSE(
[AC_LANG_PROGRAM(
[[#include <stdlib.h>
- ]],
- [[void *volatile p = aligned_alloc (2, 18);
- return p == NULL;
+ /* Use paligned_alloc to test; 'volatile' prevents the compiler
+ from optimizing the malloc call away. */
+ void *(*volatile paligned_alloc) (size_t, size_t)
+ = aligned_alloc;]],
+ [[void *p = paligned_alloc (2, 18);
+ void *q = paligned_alloc (sizeof (void *), 0);
+ return p == NULL || q == NULL;
]])
],
[gl_cv_func_aligned_alloc_works=yes],
diff --git a/tests/test-aligned_alloc.c b/tests/test-aligned_alloc.c
index caad2c7442..e4aba98221 100644
--- a/tests/test-aligned_alloc.c
+++ b/tests/test-aligned_alloc.c
@@ -35,7 +35,10 @@ main (int argc, char *argv[])
{
#if HAVE_ALIGNED_ALLOC
static size_t sizes[] =
- { 13, 8, 17, 450, 320, 1, 99, 4, 15, 16, 2, 76, 37, 127, 2406, 641, 5781 };
+ {
+ 13, 8, 17, 450, 320, 1, 99, 4, 15, 16,
+ 2, 76, 37, 127, 2406, 641, 5781, 0
+ };
void *volatile aligned2_blocks[SIZEOF (sizes)];
void *volatile aligned4_blocks[SIZEOF (sizes)];
void *volatile aligned8_blocks[SIZEOF (sizes)];
--
2.43.0
