| Issue |
161854
|
| Summary |
Clang Thread Safety: False positive warning generated in C code when accessing fields of a struct
|
| Labels |
clang
|
| Assignees |
|
| Reporter |
DobroSun
|
```c
// Compiling with: clang -Wthread-safety main.c
struct __attribute__((lockable)) Mutex {};
struct Foo {
struct Mutex mu;
int value __attribute__((guarded_by(mu)));
};
void mutex_lock(struct Mutex* mu) __attribute__((exclusive_lock_function(mu)));
void mutex_unlock(struct Mutex* mu) __attribute__((unlock_function(mu)));
struct Mutex mu;
int value __attribute__((guarded_by(mu)));
int main() {
{
mutex_lock(&mu);
value = 123; // Works!
mutex_unlock(&mu);
}
{
struct Foo foo = {};
mutex_lock(&foo.mu);
foo.value = 123; // warning: writing variable 'value' requires holding mutex 'mu' exclusively [-Wthread-safety-analysis]
mutex_unlock(&foo.mu);
}
return 0;
}
```
Compiled on Fedora 42 with clang 20.1.8, although I tried clang 21.1.2 and the issue still persists.
Renaming the file to main.cpp and compiling with clang++ doesn't generate this kind of error. Maybe I'm doing something here incorrectly or is this actually a compiler bug? Can't tell myself...
![]()
_______________________________________________
llvm-bugs mailing list
[email protected]
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
