[Bug c++/14024] g++ isn't reporting aliasing warnings

[pinskia at gcc dot gnu dot org]

------- Comment #9 from pinskia at gcc dot gnu dot org  2005-12-07 16:38 -------
(In reply to comment #8)
> that comparison isn't quite fair. strict aliasing is an optimisation that
> breaks code when compiled with a newer version of gcc, and there is lots of
> code to fix because of that. 

Actually it is.  Since GCC now uses the fact that signed types overflow is
undefined more than before.
I know since I was the one who made GCC use that fact more.  (there are even
more going in for 4.2).
Aliasing is not that much different as every one who writes C or C++ should
know the rules about aliasing and signed overflow but most don't.  Though
aliasing violations is the most reported bug, we still get bugs about signed
overflow.  Both have a way to turn off the optimization that uses the facts
that the standard provides.  Though both make the code really invalid C++.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14024