clang -Warray-bounds gives a false positive when there are compilation errors

[fahadnayyar]

#define foo(i, arr) ((i > 0) ? arr[i-1] : 0)

int main(void) {
	does_not_exist();

	int arr[] = {1, 2, 3};
	foo(0, arr);
}

clang thinks that when i is 0, we can access an out of bounds index through arr[i-1] even though we guard that access with the check (i > 0).

https://godbolt.org/z/hzfn81ds3

[llvmbot]

@llvm/issue-subscribers-c

Author: None (fahadnayyar)

#define foo(i, arr) ((i > 0) ? arr[i-1] : 0)

int main(void) {
	does_not_exist();

	int arr[] = {1, 2, 3};
	foo(0, arr);
}

clang thinks that when i is 0, we can access an out of bounds index through arr[i-1] even though we guard that access with the check (i > 0).

https://godbolt.org/z/hzfn81ds3

[fahadnayyar]

@shafik can you please help me triage this issue?