From: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Date: Tue, 15 Aug 2023 16:00:00 +0000 (+0000)
Subject: Fix _AC_LANG_IO_PROGRAM(C) to work with glibc 2.38 headers
X-Git-Tag: v2.72d~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ea3e0cec2e66132e34228546256a1657c7b9b2e9;p=thirdparty%2Fautoconf.git

Fix _AC_LANG_IO_PROGRAM(C) to work with glibc 2.38 headers

Following the glibc commit glibc-2.38~268 ("libio: Add __nonnull
for FILE * arguments of fclose and freopen"), the utilization of the gcc
-fanalyzer flag in combination with the -Werror flag leads to an error
within the _AC_LANG_IO_PROGRAM(C) function:

conftest.c:14:23: error: use of possibly-NULL 'f' where non-null expected [CWE-690] [-Werror=analyzer-possible-null-argument]

* lib/autoconf/c.m4 (_AC_LANG_IO_PROGRAM): Exit upon encountering
fopen() error.

See also https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109570 and
https://gcc.gnu.org/g:c9a19621a07e246385ae075b61283140b23c3b5a .

Tiny-change: yes
---

diff --git a/lib/autoconf/c.m4 b/lib/autoconf/c.m4
index b8350c339..77ff1af8e 100644
--- a/lib/autoconf/c.m4
+++ b/lib/autoconf/c.m4
@@ -114,6 +114,8 @@ $2
 m4_define([_AC_LANG_IO_PROGRAM(C)],
 [AC_LANG_PROGRAM([@%:@include <stdio.h>],
 [FILE *f = fopen ("conftest.out", "w");
+ if (!f)
+  return 1;
  return ferror (f) || fclose (f) != 0;
 ])])