https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105947
Bug ID: 105947
Summary: RFE: -fanalyzer should complain about jumps through
NULL function pointers
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: analyzer
Assignee: dmalcolm at gcc dot gnu.org
Reporter: dmalcolm at gcc dot gnu.org
Blocks: 105887
Target Milestone: ---
-fanalyzer already complains about jumps through uninitialized function
pointers:
uninit-1.c: In function ‘calling_uninit_fn_ptr_2’:
uninit-1.c:140:10: warning: use of uninitialized value ‘fn_ptr’ [CWE-457]
[-Wanalyzer-use-of-uninitialized-value]
140 | return fn_ptr ();
| ^~~~~~~~~
‘calling_uninit_fn_ptr_2’: events 1-2
|
| 139 | int (*fn_ptr) (void);
| | ^~~~~~
| | |
| | (1) region created on stack here
| 140 | return fn_ptr ();
| | ~~~~~~~~~
| | |
| | (2) use of uninitialized value ‘fn_ptr’ here
|
but it fails to complain about jumps through NULL function pointers, e.g. it is
silent for:
$ cat gcc/testsuite/gcc.dg/analyzer/function-ptr-5.c
#define NULL ((void *)0)
void calling_null_fn_ptr_1 (void)
{
void (*fn_ptr) (void) = NULL;
fn_ptr ();
}
int calling_uninit_fn_ptr_2 (void)
{
int (*fn_ptr) (void) = NULL;
return fn_ptr ();
}
We should complain about jumps through known-to-be-NULL function pointers
(probably with a new warning e.g. -Wanalyzer-jump-through-null or somesuch).
Compare with:
https://clang.llvm.org/docs/analyzer/checkers.html#core-callandmessage-c-c-objc
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105887
[Bug 105887] [meta-bug] clang analyzer warnings that GCC's -fanalyzer could
implement
