[cfe-dev] Trying again - building 64bit code on Windows

[Edward Diener via cfe-dev]

On 8/25/2015 2:41 AM, Yaron Keren via cfe-dev wrote:
> That looks likea collision between the 32 bit and 64 bit versions of mingw.
> Which version of 32 bit and 64 bit versions exactly do you, could you
> provide download links?
> I ask because there are several mingw distributions around and they are
> different.

The 32-bit version of mingw-64/gcc I am using is:

i686-5.1.0-posix-dwarf-rt_v4-rev0

The 64-bit version of mingw-64/gcc I am using is:

x86_64-5.1.0-posix-seh-rt_v4-rev0

I use the mingw-64 installer called 'mingw-w64-install.exe' to install 
various flavors of mingw-64.

If I run dependency walker on the 32-bit version of clang I have built 
from source with the 32-bit version of mingw-64/gcc above it shows a 
dependency in the clang++.exe on:

c:\utilities\mingw-w64\i686-5.1.0-posix-dwarf-rt_v4-rev0\mingw32\bin\LIBGCC_S_DW2-1.DLL
c:\utilities\mingw-w64\i686-5.1.0-posix-dwarf-rt_v4-rev0\mingw32\bin\LIBSTDC++-6.DLL

This means that the build of clang from source is linking to 
mingw-64/gcc 32-bit DLLs needed to run clang. So the build constrains 
clang to run only with the version of mingw-64/gcc with which it was built.

I did not change any of the default CMake build parameters that I know 
of. Is there a CMake build parameter which removes this constraint so 
that the version of clang is not dependent on the version of 
mingw-64/gcc with which it is built ?

>
>
> 2015-08-25 7:43 GMT+03:00 Edward Diener via cfe-dev
> <cfe-dev-NBbBogny7ofFcdTEL8lfRQ at public.gmane.org
> <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ at public.gmane.org>>:
>
>     On 8/24/2015 11:38 PM, Yaron Keren via cfe-dev wrote:
>
>             Evidently to build a version of clang on Windows targeting
>             mingw-64/gcc, which can compile 64-bit code, one must build
>             clang with a 64-bit version of mingw-64/gcc. This may be
>             apparent to you and other clang developers but it was not
>             apparent to me.
>
>
>         clang may be built with any supported regardless the target. For
>         example, I'm building clang using Visual C++ 64 bit and
>         targetting the
>         32-bit version of mingw. You do need to have the target mingw
>         installed
>         for the include files, library files and linker.
>
>
>     Please see my other response in this thread to Ivan. My experience
>     is clearly that a 32-bit version of clang does not work when a
>     64-bit version of mingw-64/gcc is first in the Windows PATH. I also
>     explained this previously in my post "Clang on Windows targeting
>     mingw-64/gcc building 64bit code", which was unanswered.
>
>
>
>
>         2015-08-25 5:15 GMT+03:00 Edward Diener via cfe-dev
>         <cfe-dev-NBbBogny7ofFcdTEL8lfRQ-XMD5yJDbdMReXY1tMh2IBg at public.gmane.org
>         <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ-XMD5yJDbdMReXY1tMh2IBg at public.gmane.org>
>         <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ-XMD5yJDbdMReXY1tMh2IBg at public.gmane.org
>         <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ-XMD5yJDbdMTcBkidbGgD4Q at public.gmane.orgg>>>:
>
>              On 8/24/2015 6:27 PM, Hans Wennborg via cfe-dev wrote:
>
>                  On Mon, Aug 24, 2015 at 2:36 PM, Edward Diener via cfe-dev
>                  <cfe-dev-NBbBogny7ofFcdTEL8lfRQ at public.gmane.org
>         <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ at public.gmane.org>
>
>         <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ-XMD5yJDbdMReXY1tMh2IBg at public.gmane.org
>         <mailto:cfe-dev-NBbBogny7ofFcdTEL8lfRQ-XMD5yJDbdMReXY1tMh2IBg at public.gmane.org>>>
>         wrote:
>
>                      Is clang built form the latest svn source capable of
>                      creating 64-bit code on
>                      a Microsoft Windows 64-bit OS ?
>
>
>                  Yes. We build 64-bit Chromium on Windows with Clang
>         continuously.
>
>                      If yes, is this done through the -m64 option
>                      or do I have to build clang from source in some
>         particular
>                      way to enable the
>                      functionality ?
>
>
>                  Yes, using clang-cl -m64 is how we do it.
>
>
>              Evidently to build a version of clang on Windows targeting
>              mingw-64/gcc, which can compile 64-bit code, one must build
>         clang
>              with a 64-bit version of mingw-64/gcc. This may be apparent
>         to you
>              and other clang developers but it was not apparent to me.
>
>              I would like to add to the documentation on the clang "Getting
>              Started: Building and Running Clang" page at
>         http://clang.llvm.org/get_started.html a section of documentation
>              following the section "Using Visual Studio" called "Using
>              mingw(-64)/gcc". This section would explain how to build
>         clang on
>              Windows using ninja, CMake, and a mingw(-64)/gcc
>         implementation and
>              how to run clang from the command line using a
>         mingw(-64)/gcc RTL. I
>              am willing to completely write this documentation, to be
>         vetted by
>              whatever clang developer takes care of that "Getting
>         Started" page,
>              in order to help other developers build and run clang on
>         Windows
>              with the mingw(-64)/gcc RTL.