https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70143
Bug ID: 70143
Summary: [6 Regression?] false strict-aliasing warning
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: jan.kratochvil at redhat dot com
Target Milestone: ---
struct a {
int i;
};
struct b {
struct a a;
int j;
};
int main(void) {
static struct b b;
struct a *ap=(struct a *)&b;
return ((struct b *)&ap->i)->j;
}
-------------------------------------------------------------------------------
-Wall -O2
aliasing.c: In function ‘main’:
aliasing.c:11:19: warning: dereferencing type-punned pointer will break
strict-aliasing rules [-Wstrict-aliasing]
return ((struct b *)&ap->i)->j;
^
FAIL:
gcc (GCC) 6.0.0 20160308 (experimental)
gcc-6.0.0-0.15.fc24
gcc-6.0.0-0.15.fc25
PASS:
gcc-6.0.0-0.14.fc24
gcc-5.3.1-2.fc23.x86_64
Pedro Alves said it is a GCC Bug so I am filing it here.
https://sourceware.org/ml/binutils/2016-03/msg00120.html
