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[Bug c++/53220] [4.7/4.8 Regression] g++ mis-compiles compound literals
- From: "jason at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Mon, 07 May 2012 14:29:52 +0000
- Subject: [Bug c++/53220] [4.7/4.8 Regression] g++ mis-compiles compound literals
- Auto-submitted: auto-generated
- References: <bug-53220-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53220
Jason Merrill <jason at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC|jason at redhat dot com |jason at gcc dot gnu.org
Target Milestone|4.7.1 |4.8.0
--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> 2012-05-07 14:29:52 UTC ---
Compound literals are not part of C++, so correctness is a matter of debate.
In C, a compound literal designates an object with automatic storage duration.
In G++, a compound literal designates a temporary object, just like a normal
cast or function-like cast.
This is a significant difference in semantics, which leads to the problem
encountered here; the temporary object goes out of scope immediately after the
initialization of p, so the loop has undefined behavior.
It would be possible for G++ to model the C semantics more closely.