https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99945
Bug ID: 99945
Summary: missing maybe-uninitialized warning when using a
cleanup function
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: vincent-gcc at vinc17 dot net
Target Milestone: ---
Consider the following testcase:
int foo1 (void);
int foo2 (int);
#ifdef D
#define N
#else
#define N !
#endif
int bar (void)
{
int i;
auto void cf (int *t) { foo2 (i); }
int t __attribute__ ((cleanup (cf)));
t = 0;
if (foo1 ())
i = foo1 ();
i = N foo1 () || i;
foo2 (i);
return 0;
}
With a GCC snapshot built a few hours ago from the master branch on x86_64:
cventin% gcc --version
gcc (GCC) 11.0.1 20210406 (experimental)
cventin% gcc -Werror=maybe-uninitialized -O2 -c file.c
cventin% gcc -Werror=maybe-uninitialized -O2 -c file.c -DD
cventin% gcc -Werror=maybe-uninitialized -O2 -c file.c -fsanitize=undefined
cventin% gcc -Werror=maybe-uninitialized -O2 -c file.c -fsanitize=undefined -DD
file.c: In function ‘bar’:
file.c:21:17: error: ‘FRAME.1.i’ may be used uninitialized
[-Werror=maybe-uninitialized]
21 | i = N foo1 () || i;
| ~~~~~~~~^~~~
file.c:10:5: note: ‘FRAME.1’ declared here
10 | int bar (void)
| ^~~
cc1: some warnings being treated as errors
Except in the last case, the warning is missing, though -fsanitize=undefined
should have no influence, and whether one does "! foo1 ()" or "foo1 ()" should
have no effects either.
