includes not found on MSYS2

[firewave]

Encountered while working on #475.

#include "a.h"

./simplecpp $(pwd)/a.cpp

/s/GitHub/simplecpp-fw/a.cpp:1: missing header: Header not found: "a.h"

This causes most of integration-tests.py to fail on MinGW/MSYS.

[firewave]

CC @glankk

The issue is that CreateFileA() fails because it gets a MSYS/Cygwin path (e.g. /s/path/a.h) and not a Windows one (e.g. S:/path/a.h).

Simply converting this a to the proper syntax is not sufficient since the path could be internal to MSYS2 (e.g. /tmp/path/a.h) which is the case in the failing tests.

We also need to run tests for such binaries inside a regular cmd (if possible).

[glankk]

Related to this, there is currently some ambiguity in the windows and windows-adjacent code due to the SIMPLECPP_WINDOWS macro that is defined in various circumstances. I think the correct way to handle windows code is to get rid of SIMPLECPP_WINDOWS and use _WIN32 as the source of absolute truth. When targeting the cygwin/msys runtime (not mingw32/64) then the posix code should suffice, and ideally we shouldn't ever need to check __CYGWIN__ or __MINGW32__.

[firewave]

I was thinking the same. Probably need to add a Cygwin workflow as well.

[glankk]

integration-tests.py passes on msys2 mingw when run with mingw-w64-*-python which uses windows paths. I think that is the correct approach to fix this issue. The _WIN32 change described above seems to fix the msys/cygwin issues, I'll make a PR with that. There's still some issues with compiler warnings and libc++ linking with clang. See my mingw-ci fork; https://github.com/glankk/simplecpp/tree/mingw-ci.

[firewave]

While at it we could also add #define WIN32_LEAN_AND_MEAN before the include.

I guess that assertions might not work with MinGW - or maybe we need the CLANG64 build. Will do some tests later.

And we should still have tests where non-Windows are being used. No idea if by shell or "wrong" Python interpreter.

And maybe get #438 merged first as well.

[firewave]

It only links with libc++ when using CLANG64. I will update the workflow.

[firewave]

I updated the workflow. Please post only your source changes (I would like to keep the warnings stuff to the commit where it actually appears) as a PR.

[glankk]

Done, see #531.