Re: [boost] [regression runner] Preference libstdc++ vs. libc++

Subject: Re: [boost] [regression runner] Preference libstdc++ vs. libc++
From: Edward Diener (eldiener_at_[hidden])
Date: 2017-03-08 17:42:59

On 3/8/2017 11:47 AM, Niall Douglas via Boost wrote:
>>> Oh, and the reference to Update 2 is when it started to compile the
>>> Windows headers without any special options.
>>
>> I installed the "Clang with Microsoft codegen", aka C2/clang, for VS2015
>> in order to see what I might need to do to integrate it into Boost
>> PP/VMD. I then went looking for documentation in the VS2015 IDE Help for
>> how to use it either from the IDE or command line. Absolutely no
>> documentation exists within Visual Studio 2015 about it, nor is there
>> any official docs anywhere on the web which I could find. I doubt very
>> much whether this is a viable option in VS2015 for compiling Boost
>> libraries. I will take a look again with VS2017, which I have just
>> downloaded, but considering that no documentation for this exists AFAICS
>> I highly doubt whether this Microsoft offering, whatever it is, will
>> work with Boost. Call me a skeptic, but if I a C++ product is released
>> without documentation, whether from Microsoft or anyone else, I have
>> great doubts that it will actually work with C++ standard code.
>
> I vaguely remember Boost Build added support for C2 clang a while back.
> That would be VS2015 located C2 clang, VS2017 uses some very weird path
> for it.
>
> cmake has also built in support for C2 clang, it's something like -T
> v140_clang_c2.
>
> In terms of documentation for it, basically it works like LLVM clang
> except for additional ICEs, it doesn't support a lot of the SIMD
> intrinsics, and you can debug its output fully. A really fun thing you
> can do with C2 clang is turn on the sanitisers and they nearly actually
> work.

Thanks, but that is not documentation. I cannot even find information 
how to use it from the command line or in the IDE.

Needless to say if it works like LLVM clang for Windows targeting VC++ 
it is worthless as far as Boost is concerned. The fact that it is not 
documented means to me that Microsoft has produced vapourware and just 
given it a name.

>
> Niall
>