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Re: Undefined behavior due to 220.127.116.11p3
- From: Jonathan Wakely <jwakely dot gcc at gmail dot com>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: "gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Wed, 11 Mar 2015 16:59:17 +0000
- Subject: Re: Undefined behavior due to 18.104.22.168p3
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- References: <54FDF3CE dot 6030507 at robbertkrebbers dot nl> <54FF195B dot 5060604 at redhat dot com> <54FF1F7C dot 5050501 at robbertkrebbers dot nl> <54FF2182 dot 1090800 at robbertkrebbers dot nl> <alpine dot DEB dot 2 dot 10 dot 1503102153590 dot 10726 at digraph dot polyomino dot org dot uk> <550042BD dot 8000608 at robbertkrebbers dot nl> <20150311160815 dot GA2967 at ypig dot lip dot ens-lyon dot fr> <20150311161155 dot GM1746 at tucnak dot redhat dot com>
On 11 March 2015 at 16:11, Jakub Jelinek wrote:
> There is some PR about it in our bugzilla, and the conclusion is that
> it is both invalid (in C only one union member can be active at any time,
> we as extension allow type punning through unions etc.)
> and we really don't want to support it.
I thought type punning was valid since C99 (but not C89 or any version of C++).