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[Bug regression/40665] dereferencing type-punned pointer warnings cannot be disabled
- From: "mikulas at artax dot karlin dot mff dot cuni dot cz" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 7 Jul 2009 01:34:08 -0000
- Subject: [Bug regression/40665] dereferencing type-punned pointer warnings cannot be disabled
- References: <bug-40665-1600@http.gcc.gnu.org/bugzilla/>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Comment #2 from mikulas at artax dot karlin dot mff dot cuni dot cz 2009-07-07 01:34 -------
Created an attachment (id=18146)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18146&action=view)
a bug in -Wstrict-aliasing=3
This is an example of a flaw in -Wstrict-aliasing=3 (this mode is very bad,
produces many false positives on my project and I'm wondering why is it
default?)
Gcc man page says that -Wstrict-aliasing=3 produces less false positives than
-Wstrict-aliasing=2. This is counterexample, it produces "type-punned" warning
in -Wstrict-aliasing=3 mode and doesn't warn in -Wstrict-aliasing=2. I added
(void *) casts everywhere, but they don't quash the warning.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40665