https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99919
Bug ID: 99919
Summary: [9/10/11 Regression] bogus -Wmaybe-uninitialized with
a _Bool bit-field
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
This is the -Wmaybe-uninitialized subset of pr99918 showing how the failure to
fail _Bool bit-field expressions can cause bogus warnings. (Like pr99918, this
was most likely caused by r225825.)
$ cat z.c && gcc -O2 -S -Wall z.c
struct B { _Bool i: 1; _Bool j: 1; };
_Bool z;
void g (struct B b)
{
_Bool x;
if (b.i)
b.j = 0;
else
{
b.j = b.i;
x = b.i;
}
if (b.j)
z = x;
}
z.c: In function ‘g’:
z.c:18:7: warning: ‘x’ may be used uninitialized in this function
[-Wmaybe-uninitialized]
18 | z = x;
| ~~^~~
z.c:7:9: note: ‘x’ was declared here
7 | _Bool x;
| ^
