https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124380
Bug ID: 124380
Summary: False-positive -Wuninitialized warning when using
-ftrivial-auto-var-init
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: abbeyj+gcc at gmail dot com
Target Milestone: ---
When compiling the following with `-O1 -Wall -ftrivial-auto-var-init=zero`, a
-Wuninitialized warning is produced:
```
int get();
void sink(const int &);
inline void two() {
const int & result = get();
sink(result);
}
void one() {
two();
}
```
Output:
> $ g++ -O1 -Wall -ftrivial-auto-var-init=zero -c uninit.cpp
> In function ‘void two()’,
> inlined from ‘void one()’ at uninit.cpp:10:8:
> uninit.cpp:5:30: warning: ‘D.2801’ is used uninitialized [-Wuninitialized]
> 5 | const int & result = get();
> | ^
> uninit.cpp:5:30: note: ‘D.2801’ was declared here
> 5 | const int & result = get();
> | ^
This looks like it started in GCC 12.1 (because that's when
-ftrivial-auto-var-init=zero was introduced) and is still reproducible on the
current trunk version available on Godbolt: https://godbolt.org/z/MW6vEGEce
This is extremely similar to Bug 107411 but while that bug is now fixed, this
still reproduces.
