[CMake] Problem using VS-compiled Clang as a C/C++ compiler.

Fri Mar 4 08:35:51 EST 2016

Hi Anton,

When I say clang-cl I mean how the official llvm package does it - a 50mb
executable named cl.exe and not clang-cl.exe.

Ninja believes it compiles with visual c++, but instead it compiles with
clang. That's why you need to put the path to clang INCLUDE and PATH first.

Simply rename clang-cl.exe as cl.exe, copy it in a directory and put that
path as first in the PATH environment variable.

Cheers,
Cristian.
On Mar 4, 2016 12:16, "Anton Yartsev" <anton.yartsev at gmail.com> wrote:

> Hi Cristian,
>
> thanks for the replay. I have clang-cl first in PATH, the problem persists.
>
> $ SET PATH
> Path=D:\-Work-\llvm-3.7.1.src\-VS_build VS 2013-\Release\bin;...
>
> $cd D:\-Work-\llvm-3.7.1.src\-VS_build VS 2013-\Release\bin
> $dir
>  Directory of D:\-Work-\llvm-3.7.1.src\-VS_build VS 2013-\Release\bin
>
> 04.03.2016  14:03    <DIR>          .
> 04.03.2016  14:03    <DIR>          ..
> 04.03.2016  01:00        11 662 848 arcmt-test.exe
> 04.03.2016  01:02         6 446 080 bugpoint.exe
> 04.03.2016  01:01             9 728 c-arcmt-test.exe
> 04.03.2016  01:01            82 944 c-index-test.exe
> 04.03.2016  17:20        40 207 872 clang++.exe
> 04.03.2016  01:01        32 803 840 clang-check.exe
> 04.03.2016  17:20        40 207 872 clang-cl.exe
> 04.03.2016  01:00         1 401 856 clang-format.exe
> 04.03.2016  17:05           814 592 clang-tblgen.exe
> 04.03.2016  17:20        40 207 872 clang.exe
> ...
>
>
> Hi Anton,
>
> clang.exe doesn't know of any windows specific things.  Clang-cl instead
> does.
>
> Just make sure to have clang-cl before msvc-cl in path and ninja will just
> work.
>
> Cheers,
> Cristian
> On Mar 4, 2016 01:31, "Anton Yartsev" <anton.yartsev at gmail.com> wrote:
>
>> Hi all,
>>
>> I'm trying to use Clang, compiled with VS 2013 (configuration:Release,
>> platform:x64) as a C/C++ compiler for a simple HelloWorld CMake project.
>> Generation ends up with errors like "clang.exe: error: no such file or
>> directory: '/DWIN32'" at compiler check stage. If I understand correctly
>> the problem is that MSVC compiler options are fed to Clang for some reason
>> (maybe the "-- The C compiler identification is unknown" log entry is
>> related to the problem?).
>> Could anyone help to resolve this, please?
>>
>> I also tried to change compiler ID with "-DCMAKE_C_COMPILER_ID=Clang
>> -DCMAKE_CXX_COMPILER_ID=Clang", then compilation succeeded, but linkage
>> failed (just as described in the thread "Question on usage of cmake on
>> Windows with clang"
>> http://thread.gmane.org/gmane.comp.programming.tools.cmake.user/54650).
>> Here the problem seems to be reversed: GNU linker options are fed to MS
>> linker.
>>
>> ************** Setup and details:
>> 1) INCLUDE and PATH set to clang/clang-cl
>> 2) command line environment is configured with vsvars32.bat
>> 3) CC and CXX set to clang
>>
>> $ cat CMakeLists.txt
>> project(test_project)
>> add_executable(main file.cpp)
>>
>> $ cmake -G "Ninja" -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang ..
>>
>> Log:
>> -- The C compiler identification is unknown
>> -- The CXX compiler identification is Clang 3.7.1
>> -- Check for working C compiler using: Ninja
>> -- Check for working C compiler using: Ninja -- broken
>> CMake Error at C:/Program
>> Files/CMake/share/cmake-3.5/Modules/CMakeTestCCompiler.cmake:61 (message):
>>   The C compiler "D:/-Work-/llvm-3.7.1.src/-VS_build VS
>>   2013-/Release/bin/clang.exe" is not able to compile a simple test
>> program.
>>   It fails with the following output:
>>    Change Dir: D:/-Work-/llvm-3.7.1.src/-CLANG-/CMakeFiles/CMakeTmp
>>
>>   Run Build Command:"C:/PROGRA~1/ninja/ninja.exe" "cmTC_2cb9d"
>>
>>   [1/2] Building C object CMakeFiles\cmTC_2cb9d.dir\testCCompiler.c.obj
>>
>>   FAILED: D:\-Work-\LLVM-3~2.SRC\-VS_BU~2\Release\bin\clang.exe /DWIN32
>>   /D_WINDOWS /W3 -o CMakeFiles\cmTC_2cb9d.dir\testCCompiler.c.obj -c
>>   testCCompiler.c
>>
>>   clang.exe: error: no such file or directory: '/DWIN32'
>>   clang.exe: error: no such file or directory: '/D_WINDOWS'
>> ...
>>
>> OS: Windows 7 (x64)
>>
>> clang version 3.7.1 (tags/RELEASE_371/final)
>> Target: x86_64-pc-windows-msvc
>> Thread model: posix
>>
>> cmake version 3.5.0-rc3
>>
>> Thank you!
>>
>> --
>> Anton
>>
>> --
>>
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>
>
> --
> Anton
>
>
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