Re: [boost] Compiling with Clang 3.7.0 from windows

Subject: Re: [boost] Compiling with Clang 3.7.0 from windows
From: Edward Diener (eldiener_at_[hidden])
Date: 2015-09-03 11:23:29

On 9/3/2015 10:02 AM, Paul A. Bristow wrote:
> I've downloaded the shiny new Clang 3.7 and added this to my user-config. # 64-bit version
>   using clang # from http://llvm.org/releases/download.html
>      : # version
>        3.7.0
>      : # Clang compiler .exe location
>      #"C:/LLVM/bin/clang++.exe" # OK
>      #"C:\\Program Files (x86)\\LLVM\\bin\\clang++.exe" # OK
>      "C:\\Program Files\\LLVM\\bin\\clang++.exe" #
>      : # options
>    ;

Is this meant to be your user-config.jam entry for clang ? If so, it is 
hard to follow.

This is my experience with clang built from source:

If you are running clang as a 64-bit compiler you need to "use" a 64-bit 
version of mingw-64, and not mingw which is only 32-bits. By "use" I 
mean one of two things. Either the 'bin' directory of the 64-bit version 
should be prepended to your Windows PATH when invoking clang++ or you 
use the '--sysroot=some_mingw' option on the command line when invoking 
clang++, where 'some_mingw' is the path to the 64-bit mingw 
implementation. I have not used the second method but have been told it 
should work.

What I do, in a batch file before invoking clang++, is to prepend to the 
Windows PATH the clang++ bin directory followed by the bin directory of 
the mingw-64 implementation I want clang to use. Then when clang++ is 
invoked it finds everything properly. If you are compiling clang++ for 
32-bit code you need to "use" a 32-bit version of mingw(-64)/gcc and if 
you are compiling clang++ for 64-bit code you need to "use" a 64-bit 
version of mingw-64/gcc.

As far as pre-built versions of clang I have used clang 3.6.2, 3.5.2, 
and clang 3.4.1. None of these versions could "use" mingw-64 but only 
mingw. This means that none of these versions could be used to compile 
64-bit code since mingw only supports 32-bit code. I have not tried the 
new pre-build clang 3.7 yet, which supposedly is capable of using 
mingw-64 ( I know the latest clang built from source can "use" mingw-64 
but I am not sure if this capability got into the 3.7 release ).