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[v2,0/5] avoid -Wuse-after-free [BZ #26779]

Message ID 53f20975-a2c9-674d-2a43-b1b323ee545c@gmail.com
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Martin Sebor Jan. 25, 2022, 12:52 a.m. UTC 
  This is a repost of the original patch but broken down by source
file and with some suppression done by #pragma GCC diagnostic
instead of conversion to intptr_t.  It also adds fixes for
the same problem in the test suite that I overlooked before.

On 1/15/22 17:21, Martin Sebor wrote:
> GCC 12 features a couple of new warnings designed to detect uses
> of pointers made invalid by the pointees lifetimes having ended.
> Building Glibc with the enhanced GCC exposes a few such uses,
> mostly after successful calls to realloc.  The attached patch
> avoids the new warnings by converting the pointers to uintptr_t
> first and using the converted integers instead.
> 
> The patch suppresses all instances of the warning at the strictest
> setting (-Wuse-after-free=3), which includes even uses in equality
> expressions.  The default setting approved for GCC 12 is
> -Wuse-after-free=2, which doesn't warn on such uses to accommodate
> the pointer-adjustment-after-realloc idiom.  At the default setting,
> the changes to ldconfig.c and setenv are not necessary.
> 
> Martin