https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123985
Bug ID: 123985
Summary: Inconsistent -Wuninitialized behavior under -O0
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: qcf at ecnelises dot com
Target Milestone: ---
```
struct A { A() = default; int m; double d; };
struct B { B() {} int m; double d; };
struct C { int m; double d; };
void foo(int);
int main() {
A a; foo(a.m);
B b; foo(b.m);
C c; foo(c.m);
}
```
- With -Wuninitialized -O, all three lines trigger warnings.
- With -Wuninitialized -O0, only A and C trigger warnings.
- Reorder code in main to B-C-A and with -O0, only C triggers warning.
