https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71885
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
An optimizing compiler optimizes on the assumption that undefined behavior does
not happen. So, if you want to keep using code that invokes undefined behavior
(which is a very bad idea), you need to be prepared to pass some extra options
that tell the compiler not to do it.
-flitefime-dse=1 or -fno-lifetime-dse in this case (the latter if you also
"assume" that object after its destruction will still contain the data you've
stored in there), -fno-aggressive-loop-optimizations, -fno-strict-aliasing, -O0
in certain cases, in some cases there just isn't an option.
The -Wuninitialized* family of warnings is able to warn in certain cases about
this problem, but you of course don't get a guarantee this will be warned about
every time.
