On Mon, 6 Jan 2025, Pali Rohár wrote:
All 32-bit Windows NT systems contains system OS library msvcrt40.dll which
should be compatible with the original Visual C++ 4.0/4.1 msvcrt40.dll library.
The Windows NT implementation of msvcrt40.dll is very simple, it just
redirects function calls via symbol forwarding to msvcrt.dll library.
Since Windows XP, the msvcrt.dll changed ABI of __getmainargs() and
__wgetmainargs() functions, and so it is required also for msvcrt40.dll
builds to include ABI fix code which is already used for msvcrt.dll builds.
Otherwise applications compiled with new mingw-w64 checks introduced since
commit 3e043834e993 ("crt: Check for return value from __(w)getmainargs()
calls") would crash on Windows XP+ systems if they would use the system
msvcrt40.dll library.
I don't understand why they would crash?
If they are compiled with misc/msvcrt40__getmainargs.c, they end up
calling msvcrt40.dll's __getmainargs(), ignoring any return value from it,
as it is expected to have a void return type.
If that code runs on a newer msvcrt40.dll (which redirects to msvcrt.dll,
with the new ABI), I don't see how things would crash? On success, it
should work just fine. _If_ there's a failure in it, we would miss it
though - as misc/msvcrt40__getmainargs.c expects that the function
terminates the process on error, while it would just return an error code
and expect the caller to handle it.
So I don't understand this patch from the point of view of how it is
explained. The change itself looks acceptable from the point of view of
"fix catching error cases on msvcrt40.dll" though.
// Martin
_______________________________________________
Mingw-w64-public mailing list
Mingw-w64-public@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
