[New-bugs-announce] [issue18028] Warnings with -fstrict-aliasing

[Bohuslav "Slavek" Kabrda]

New submission from Bohuslav "Slavek" Kabrda:

Hi,
I'm getting these warnings with -fstrict-aliasing, compiling Python 3.3.2 (compiling with gcc 4.4.7):

/builddir/build/BUILD/Python-3.3.2/Python/ceval.c: In function 'PyEval_EvalFrameEx':
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1006: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1007: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1008: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1009: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1249: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1258: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:1372: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2358: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2362: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2377: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2379: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2388: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2390: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2743: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2745: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2896: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:2909: warning: dereferencing type-punned pointer will break strict-aliasing rules
/builddir/build/BUILD/Python-3.3.2/Python/ceval.c:3035: warning: dereferencing type-punned pointer will break strict-aliasing rules

This seems to be quite serious, but I'm not a C expert, so I'd like to know whether this is a false positive or this is actually a dangerous bug.
Thanks.

----------
components: Build
messages: 189729
nosy: bkabrda
priority: normal
severity: normal
status: open
title: Warnings with -fstrict-aliasing
versions: Python 3.3

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue18028>
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