| Issue |
136379
|
| Summary |
-Warray-bounds misses unsafe pointer arithmetic
|
| Labels |
new issue
|
| Assignees |
|
| Reporter |
shuffle2
|
I would expect the following to issue a warning:
```c
void g(uint64_t a, uint64_t b) {
printf("%lx %lx\n", a, b);
}
int main(int argc, char **argv) {
uint8_t a;
// one-past the end is valid (as long as not deref'd)
g((uint64_t)&a, (uint64_t)(&a + 1));
// >1 past end is invalid
// XXX clang has -Warray-bounds, but it does not warn on the below.
// clang's -Wunsafe-buffer-usage *does* warn on it, though.
// -Wunsafe-buffer-usage doesn't seem usable in real world tho for C code. (lots of false positives).
g((uint64_t)&a, (uint64_t)(&a + 2));
return 0;
}
```
gcc detects this as I'd expect, clang does not: https://godbolt.org/z/WEYTzMGGb
It's unclear to me if -Wunsafe-buffer-usage is the expected solution here - this flag seems unhelpful for plain C code. https://clang.llvm.org/docs/SafeBuffers.html makes it sound like the flag is mainly for use in C++ code, to detect locations that should be converted to c++-specific code patterns.
![]()
_______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
