https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104761
Bug ID: 104761
Summary: [12 Regression] False positive -Wdangling-pointer
warning on NetworkManager since r12-6606
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: jakub at gcc dot gnu.org
Target Milestone: ---
With -O0 -Wdangling-pointer or -O2 -Wall (the latter is a regression) the
following testcase emits 2 false positive warnings:
nm-shared-utils.i: In function ‘test’:
nm-shared-utils.i:21:40: warning: dangling pointer to ‘error’ may be used
[-Wdangling-pointer=]
21 | corge (qux (addrbin.s), error->t);
| ^~
nm-shared-utils.i:18:45: note: ‘error’ declared here
18 | __attribute__((__cleanup__ (bar))) T *error = (T *) 0;
| ^~~~~
nm-shared-utils.i:21:11: warning: dangling pointer to ‘addrbin’ may be used
[-Wdangling-pointer=]
21 | corge (qux (addrbin.s), error->t);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
nm-shared-utils.i:13:5: note: ‘addrbin’ declared here
13 | S addrbin;
| ^~~~~~~
Commenting out the endless loop makes it go away.
Started with the addition of -Wdangling-pointer in
r12-6606-g9d6a0f388eb048f8d87f.
typedef struct { unsigned int s; } S;
int foo (S *);
typedef struct { char *t; } T;
void garply (T *);
static inline void bar (T **v) { if (*v) garply (*v); }
int baz (T **);
const char *qux (unsigned);
void corge (const char *, const char *);
int
test (int x)
{
S addrbin;
if (foo (&addrbin) != 1)
return 0;
if (x == 2)
{
__attribute__((__cleanup__ (bar))) T *error = (T *) 0;
if (!baz (&error))
{
corge (qux (addrbin.s), error->t);
for (;;)
;
}
}
return 1;
}
