[cfe-dev] [GSoC] "Microsoft Visual C++ ABI support in Clang" proposal

[Óscar Fuentes]

Charles Davis <cdavis at mymail.mines.edu> writes:

> Title: Microsoft Visual C++ ABI support in Clang
>
> Abstract:
>
> Both GCC and Clang default to using the Itanium C++ ABI. However, the de
> facto standard C++ ABI on Windows is the one provided by Microsoft in
> their Visual C++ product.

Long time ago I used a lot of Windows C++ compilers and the only one
that was compatible with VC++ was Intel. Are there any others that
switched to the MS C++ ABI? Just curious.

[snip]

> In this project, I will implement enough of the Visual C++ ABI to get
> simple programs working, such as the C++ "Hello, world" program. If time
> permits, which I admit it likely will, I will implement additional
> features. Features covered by the scope of this project include
> everything outside of exception handling, including name mangling
> (already partially implemented), class layout, vtable layout, calls to
> virtual functions, and accesses of members in virtual bases. Proper EH
> support requires SEH support and is thus beyond the scope of this project.

LLVM needs some non-trivial enhancements. See PR5058 and PR5064. Also
note the claims about MS C++ ABI being undocumented on the commentaries
to the last PR.

Did you investigate the legal status of the pieces of VC++ ABI?

[snip]