elfutils does not compile with gcc 12.2.0

[Dmitry V. Levin]

On Wed, Aug 24, 2022 at 10:51:13PM +0200, Nick via Elfutils-devel wrote:
> I try to compile elfutils on OpenWrt with the newest gcc 12.2.0 version. 
> However, it fails due to -Werror=use-after-free. A workaround is a patch 
> that I found on the mailinglist, to disable -Werror 
> (https://sourceware.org/legacy-ml/elfutils-devel/imported/msg00994.html) 
> I modified it to apply to newest elfutils version. The error with 
> elfutils 0.187 and gcc 12.2.0:
> 
> In function 'bigger_buffer',
>      inlined from '__libdw_gunzip' at gzip.c:376:12:
> gzip.c:98:9: error: pointer may be used after 'realloc' 
> [-Werror=use-after-free]
>     98 |     b = realloc (state->buffer, more -= 1024);
>        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> gzip.c:96:13: note: call to 'realloc' here
>     96 |   char *b = realloc (state->buffer, more);
>        |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This warning is definitely wrong, looks like a regression in gcc, please
report this to compiler people, otherwise they will never know they
introduced a bug that needs fixing.


-- 
ldv