[LLVMdev] Unifying Windows Target Triples

[Reid Kleckner]

This mostly all makes sense to me.

If someone feels strongly about changing "win32" to "windows", they can do
that, but we have to keep accepting win32 as a synonym.  I'd accept it even
when used with new ISAs like armv7.

The way we have multiple Windows-ish OSs is probably silly, and should be
unpacked to something like -win32-gnu, -win32-msvc, and -win32-itanium.

Internally we should map -mingw32 to -win32-gnu and -win32 to -win32-msvc.
 I may be biased in favor of the second mapping, but it's what we've been
doing for a few months now.

I'm not sure if we should attempt to map cygwin to -win32-cyg(win)?.  It's
really a different beast.

For the PE portion, I agree we should split it with a dash if its going to
be there.  And if we do that, we can pull ELF and MachO out of the
Environment enum and make a new one for object file format.  The object
file format should be populated implicitly with the canonical format for
the OS, and can be overridden if present.


On Thu, Feb 27, 2014 at 11:59 PM, NAKAMURA Takumi <geek4civic at gmail.com>wrote:

> Saleem,
>
> Thanks to open the Pandora's box!
>
> I am certain "Win32" should be common word to represent Win32 API (ABI
> in some context).
> Then, I preferer -win32- rather than -windows-.
> If we could use *-win32, I hope it might be neutral as possible.
> That said, I don't have concrete plan what *-win32 should be.
>
> In other words, I think it'd be worse that "*-pc-win32" represents
> whole msvc things.
>
> I could make the matrix later. This is a random note.
>
> * i686-pc-cygwin (gcc-4.x)
>   - PE/COFF
>   - Win32 compatible. Win32 API(s) could be available with <windows.h>.
>   - Doesn't use thiscall.
>   - Doesn't use msvcrt. Using newlib delivered.
>   - Uses GNU libstdc++ and libsupc++.
>   - Uses dw2 eh.
>
> * i686-pc-mingw32 (<4.6)
>   - Uses msvcrt.dll. (malloc is not 16-byte aligned). Other versions
> of msvcrt are optional.
>   - Uses some supplemental libs that incapable in msvcrt.dll.
>   - Uses libgcc
>   - Uses GNU libstdc++ and libsupc++ provided by g++
> (lib/gcc/i686-pc-mingw32)
>   - Doesn't use thiscall.
>   - dw2 is available older version of mingw32 was available only sjlj.
>
> * *-w64-mingw32 (>=4.6)
>   - Uses msvcrt.dll even on x86_64 (!!!)
>   - EH is optional, x64-comptatible eh (aka seh) may be available.
>   - multilib is available in development environment.
>   - Uses thiscall (for i686)
>   - Uses GNU libstdc++.
>
> * x86_64-pc-cygwin
>   - LP64
>   - Investigating :p
>
> I wonder if we could provide neutral *-win32 for our project, or naked
> *-win32 might be used as non-C++ environments...
> (Consider with compiler-rt, libcxxabi and libcxx)
>
> ...Takumi
>
>
> 2014-02-28 12:40 GMT+09:00 Saleem Abdulrasool <abdulras at fb.com>:
> > Hi,
> >
> > After a discussion with David, Id like to propose a rework of the
> Windows target triples.  The current set of Windows triples are somewhat
> less uniform than their Linux counterparts.  With multiple ABIs and
> environments on Windows, they are also slightly awkward.  Obviously,
> certain ones might be nice to keep around for compatibility (e.g. the mingw
> triple).
> >
> > Just to ensure that everyone has the same understanding, the canonical
> format for a triple is: arch-vendor-os-environment .
> >
> > We have the following environment on Windows:
> >
> > As far as I know, everyone conforms to the MS C ABI.
> > - There is the MS C++ ABI which is still being developed.
> > - There is the IA-64 ABI which is incompatible with msvcprt.
> > - There is the MinGW sub environment which supplies additional UNIX-y
> functions and uses IA-64 ABI for C++.
> >
> > The Windows environment is uniformly (COFF)/PE.
> >
> > As for the OS, Windows is slightly generic.  Windows 9x, Windows NT, and
> Windows CE are all slightly different.  However, given that Microsoft has
> taken a unifying strategy with Windows NT, I *think* sticking to Windows
> for the OS should be okay.  That said, I could be convinced to use winnt or
> windowsnt.
> >
> > So, one way to clearly define a naming scheme for this space would be
> something along the lines of:
> >
> > {armv7,i686,x86_64}-windows-{ia,mingw,ms}pe
> >
> > This allows us to uniformly take any of the combination IA-64 or MS C++
> ABI + MS C ABI or the MinGW environment (which is IA-64 ABI and its
> supplementary libraries).
> >
> > I understand that this may be controversial since it can potentially
> break existing code bases, but I think that the result of this is worth it.
> >
> > --
> > Saleem Abdulrasool
> > abdulras (at) fb (dot) com
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > LLVM Developers mailing list
> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140228/256d4837/attachment.html>