https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111123
Bug ID: 111123
Summary: Warning about "used uninitialized" member shown or
hidden randomly
Product: gcc
Version: 13.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: agriff at tin dot it
Target Milestone: ---
This code should warning (with -Wall) about the use of `border` that is
uninitialized
#include <stdio.h>
#include <vector>
struct Camera {
struct P2d {
float x, y;
};
std::vector<P2d> clip_area;
float border = 10.f;
int z = 3;
Camera() : clip_area({{border, border},
{1-border, border},
{1-border, 1-border},
{border, 1-border}})
{ }
};
int main() {
Camera c;
printf("%.18g\n", c.clip_area[0].x);
}
However does so only if member `z` is present; commenting out the line `int z =
3;` silences the warning.
This show/hide of the warning happens also pseudo-randomly in other cases
(while I was trying to get the minimum code showing the problem I found many
cases in which removing even an executable statement in the body of a method
triggered the behavior change).
