[cfe-dev] Failure building x86_64-w64-mingw32 triplet of clang on Windows

[Edward Diener via cfe-dev]

On 6/15/2016 2:25 AM, Yaron Keren via cfe-dev wrote:
> clang calls CMake find_package(libxml2) to find libxml2.

Where in the clang source does "find_package(libxml2)" occur ? I could 
not find <g> it.

> This is implemented in the CMake standard module
> "/usr/share/cmake-3.5/Modules/FindLibXml2.cmake".
>
>
>
> 2016-06-15 9:12 GMT+03:00 Edward Diener via cfe-dev
> <cfe-dev at lists.llvm.org
> <mailto:cfe-dev at lists.llvm.org>>:
>
>     On 6/14/2016 10:40 AM, Yaron Keren via cfe-dev wrote:
>
>         libxml is optional library, used if found.
>
>
>     Where in the llvm/clang CMake files is libxml specified ?
>
>         Maybe CMake finds your libxml2 but does not check if its 32 or
>         64 bit,
>         just assumes it's the right one?
>
>
>     I queried this on the CMake mailing list and am awaiting some answer
>     from them. But I expect that if I get one it will be to ask where
>     llvm/clang specifies libxml in its CMakeLists.txt files.
>
>
>
>
>         2016-06-14 16:59 GMT+03:00 NAKAMURA Takumi via cfe-dev
>         <cfe-dev at lists.llvm.org
>         <mailto:cfe-dev at lists.llvm.org>
>         <mailto:cfe-dev at lists.llvm.org
>         <mailto:cfe-dev at lists.llvm.org>>>:
>
>             On Tue, Jun 14, 2016 at 10:50 PM Edward Diener via cfe-dev
>             <cfe-dev at lists.llvm.org
>         <mailto:cfe-dev at lists.llvm.org>
>             <mailto:cfe-dev at lists.llvm.org
>         <mailto:cfe-dev at lists.llvm.org>>> wrote:
>
>                 On 6/14/2016 8:21 AM, NAKAMURA Takumi via cfe-dev wrote:
>                 > I guess you are building on msys2 with external mingw-w64.
>
>                 No, I am not. Ninja is calling mingw-64/gcc-5.3 directly
>         to build
>                 llvm/clang
>
>                 .
>
>                 > CMake picks up msys2's libxml2, I guess.
>
>                 I do have a 32-bit libxml2 on my Windows PATH from the
>         GnuWin32
>                 package.
>                 But why is a build of llvm/clang requiring libxml2,
>         whether a
>                 32-bit or
>                 64-bit version ?
>
>
>             I don't know why CMake finds but doesn't ignore it.
>             c-index-test uses libxml2 if available. libxml2 is not
>         essential.
>
>             We could add extra checks if libxml2 would be really available.
>
>                 > Could you try overriding CMake and reconfigure?
>                 >
>         -DCMAKE_LIBRARY_PATH="C:/mingw-w64/x86_64-4.9.3-posix-seh-rt_v4-rev1/mingw64/x86_64-w64-mingw32/lib"
>
>                 Why would using gcc-4.9.3 make any difference ?
>
>
>             Excuse me. It was just an example. Please substitute with your
>             mingw-w64's path.