Hi,
While working on a project with a messy structure and a reliance on
#pragma once, I ran into this issue.
Essentially, TCC considers the following to be different files for the
purposes of respecting #pragma once:
#include "test.h"
#include "./test.h"
#include "foo/../test.h"
// In subdir/test2.h:
#include "../test.h"
The result is that test.h is included repeatedly despite using #pragma
once.
Of course, that feature is non-standard and well-known to be
potentially troublesome. But it's used widely enough that I think this
is worth fixing.
I've attached a test case. There's an interesting difference in
behaviour between Windows and Linux when a non-existent path is
involved, but the overall issue applies regardless of platform.