https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105534
Bug ID: 105534
Summary: -Wmaybe-uninitialized shouldn't suppress
-Wuninitialized warnings
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redbeard0531 at gmail dot com
Target Milestone: ---
The following function emits a -Wuninitialized warning on ++count with -Wall
https://godbolt.org/z/KfaMEETY1:
int test(bool cond) {
int count;
++count;
return count;
}
Making the increment be conditional changes it to a -Wmaybe-uninitialized
warning, which is suppressed with -Wno-maybe-uninitialized.
https://godbolt.org/z/qarMrqW7E
int test(bool cond) {
int count;
if (cond) ++count;
return count;
}
This makes no sense. count is never initialized on any path through the
function, and it is returned on all paths.
We use -Wall with -Wno-maybe-uninitialized on our codebase because we were
getting too many false-positives with -Wmaybe-initialized, in particular from
third-party headers that we didn't want to modify. At the time we decided to do
that, we didn't realize that we would also be missing out on clearly
uninitialized cases like this.
