Add support for Flang on Windows
I'm trying to build Flang on Windows here, https://github.com/xoviat/flang/pull/2.
Flang has 2 components. The frontend
flang.exe which is built first https://github.com/flang-compiler/clang and then the actual flang drivers
flang2.exe and the Fortran runtime libraries. Frontend is built successfully.
When building the drivers, I do,
cmake -G"NMake Makefiles" -DCMAKE_CXX_COMPILER=clang_cl -DCMAKE_C_COMPILER=clang_cl -DCMAKE_Fortran_COMPILER=flang .. with Visual Studio 2015 amd64 activated. Note that this Fortran compiler is an incomplete one. Executables
flang2.exe are built successfully and then Fortran compiler is almost complete. (There are some linking issues when I try a hello-world.f90 program, but that's probably not related to the problem below)
flang_static.lib which has Fortran sources, Fortran sources are compiled correctly, but when linking the object files together it fails in the
Building fortran static library flang_static.lib step. This is because this tries to link using (contents of "link.txt" below)
"" qc ..\..\lib\flang_static.lib /machine:x64 CMakeFiles\flang_static.dir\abort3f.c.obj ... "" ..\..\lib\flang_static.lib
This is not using Microsoft's link.exe program and
qc seems to be coming from https://github.com/Kitware/CMake/blob/b8fc447c1df34eeca1d66acd0e17ca743256d6c2/Modules/CMakeCInformation.cmake#L179 where
CMAKE_AR is the first
"" in the command above.
I tried using
CMake-3.9.3 and there's no difference.
Please let me know if you need any more details.