I'm using Cygwin on Windows 10; but I've recently installed the MSVC 2019 compiler.
I can, of course, write CXX=/path/to/cl.exe (or CC=/path/to/cl.exe if I ignore how MSVC isn't a proper C compiler), but if I try configuring a C or C++ project that way, I get something like:
$ cmake -S . -B build
-- The CXX compiler identification is MSVC 19.29.30133.0
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - failed
-- Check for working CXX compiler: /cygdrive/c/Program Files (x86)/Microsoft Visual Studio/2019/BuildTools/VC/Tools/MSVC/14.29.30133/bin/HostX86/x86/cl.exe
-- Check for working CXX compiler: /cygdrive/c/Program Files (x86)/Microsoft Visual Studio/2019/BuildTools/VC/Tools/MSVC/14.29.30133/bin/HostX86/x86/cl.exe - broken
CMake Error at /usr/share/cmake-3.20.0/Modules/CMakeTestCXXCompiler.cmake:59 (message):
The C++ compiler
"/cygdrive/c/Program Files (x86)/Microsoft Visual Studio/2019/BuildTools/VC/Tools/MSVC/14.29.30133/bin/HostX86/x86/cl.exe"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: /home/joeuser/src/myproj/build/CMakeFiles/CMakeTmp
Run Build Command(s):/usr/bin/make.exe -f Makefile cmTC_1b995/fast && /usr/bin/make -f CMakeFiles/cmTC_1b995.dir/build.make CMakeFiles/cmTC_1b995.dir/build
make[1]: Entering directory '/home/joeuser/src/myproj/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_1b995.dir/testCXXCompiler.cxx.o
"/cygdrive/c/Program Files (x86)/Microsoft Visual Studio/2019/BuildTools/VC/Tools/MSVC/14.29.30133/bin/HostX86/x86/cl.exe" -o CMakeFiles/cmTC_1b995.dir/testCXXCompiler.cxx.o -c /home/joeuser/src/myproj/build/CMakeFiles/CMakeTmp/testCXXCompiler.cxx
Microsoft (R) C/C++ Optimizing Compiler Version 19.29.30133 for x86
Copyright (C) Microsoft Corporation. All rights reserved.
cl : Command line warning D9035 : option 'o' has been deprecated and will be removed in a future release
cl : Command line warning D9002 : ignoring unknown option '/home/joeuser/src/myproj/build/CMakeFiles/CMakeTmp/testCXXCompiler.cxx'
cl : Command line error D8003 : missing source filename
make[1]: *** [CMakeFiles/cmTC_1b995.dir/build.make:78: CMakeFiles/cmTC_1b995.dir/testCXXCompiler.cxx.o] Error 2
make[1]: Leaving directory '/home/joeuser/src/myproj/build/CMakeFiles/CMakeTmp'
make: *** [Makefile:127: cmTC_1b995/fast] Error 2
So, CMake is trying to pass GCC-like command-line options to MSVC. Can I get it to "play nice" and actually be able to use MSVC properly?
I've been trying to cross compile an open source library for AArch64.
When I run an executable linking against this library on a Raspberry Pi 4 (running a 64-bit OS), I get an Illegal Instruction error.
I created a github issue and the library developer suggested I enable the -mno-outline-atomics compiler flag (more details on the github issue here). More details on the flag itself can be found here.
So I edited the aarch64 cmake toolchain file (found here) to include the following:
set(CMAKE_C_FLAGS "-march=armv8-a -mno-outline-atomics")
set(CMAKE_CXX_FLAGS "-march=armv8-a -mno-outline-atomics")
However, when I try to compile the library, I get the following error messages:
-- CMAKE_TOOLCHAIN_FILE = /home/cyrus/work/c-sdks/3rd_party_libs/ncnn/toolchains/aarch64-linux-gnu.toolchain.cmake
-- CMAKE_INSTALL_PREFIX = /home/cyrus/work/c-sdks/3rd_party_libs/ncnn/build_aarch64/install
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
-- Check for working C compiler: /usr/bin/aarch64-linux-gnu-gcc
-- Check for working C compiler: /usr/bin/aarch64-linux-gnu-gcc - broken
CMake Error at /usr/local/share/cmake-3.17/Modules/CMakeTestCCompiler.cmake:60 (message):
The C compiler
"/usr/bin/aarch64-linux-gnu-gcc"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: /home/cyrus/work/c-sdks/3rd_party_libs/ncnn/build_aarch64/CMakeFiles/CMakeTmp
Run Build Command(s):/usr/bin/make cmTC_65def/fast && /usr/bin/make -f CMakeFiles/cmTC_65def.dir/build.make CMakeFiles/cmTC_65def.dir/build
make[1]: Entering directory '/home/cyrus/work/c-sdks/3rd_party_libs/ncnn/build_aarch64/CMakeFiles/CMakeTmp'
Building C object CMakeFiles/cmTC_65def.dir/testCCompiler.c.o
/usr/bin/aarch64-linux-gnu-gcc -march=armv8-a -mno-outline-atomics -o CMakeFiles/cmTC_65def.dir/testCCompiler.c.o -c /home/cyrus/work/c-sdks/3rd_party_libs/ncnn/build_aarch64/CMakeFiles/CMakeTmp/testCCompiler.c
aarch64-linux-gnu-gcc: error: unrecognized command line option ‘-mno-outline-atomics’; did you mean ‘-fno-inline-atomics’?
CMakeFiles/cmTC_65def.dir/build.make:82: recipe for target 'CMakeFiles/cmTC_65def.dir/testCCompiler.c.o' failed
make[1]: *** [CMakeFiles/cmTC_65def.dir/testCCompiler.c.o] Error 1
make[1]: Leaving directory '/home/cyrus/work/c-sdks/3rd_party_libs/ncnn/build_aarch64/CMakeFiles/CMakeTmp'
Makefile:138: recipe for target 'cmTC_65def/fast' failed
make: *** [cmTC_65def/fast] Error 2
Why is the compiler complaining about this: unrecognized command line option ‘-mno-outline-atomics’?
How can I properly enable the flag using CMake?
The outline-atomic feature was added with gcc 9.4.
-- The C compiler identification is GNU 7.5.0
-- The CXX compiler identification is GNU 7.5.0
Clearly, your compiler is too old and does not support it.
I'm trying to get a simple 'Hello World' program to build on Windows 10, preferably using CMake and clang. I can successfully compile, link and run the same project if I use the g++ compiler from MinGW, but have problems when I try using clang++.
I have CMake, MinGW and LLVM already installed and accessible in my path:
clang++
clang++: error: no input files
cmake --version
cmake version 3.16.0-rc1
I have set up environment variables for CMake to use clang:
echo %CC%
C:\Program Files\LLVM\bin\clang.exe
echo %CXX%
C:\Program Files\LLVM\bin\clang++.exe
Now when I run cmake with my simple "Hello World" C++ project, cmake complains about not being able to use clang:
cmake -G "MinGW Makefiles" ..
-- The CXX compiler identification is Clang 9.0.0 with GNU-like command-line
-- Check for working CXX compiler: C:/Program Files/LLVM/bin/clang++.exe
-- Check for working CXX compiler: C:/Program Files/LLVM/bin/clang++.exe -- broken
CMake Error at C:/Program Files/CMake/share/cmake-3.16/Modules/CMakeTestCXXCompiler.cmake:53 (message):
The C++ compiler
"C:/Program Files/LLVM/bin/clang++.exe"
is not able to compile a simple test program.
It fails with the following output:
Change Dir: C:/Users/pball/git/bchest/build/CMakeFiles/CMakeTmp
Run Build Command(s):C:/mingw-w64/x86_64-8.1.0-win32-seh-rt_v6-rev0/mingw64/bin/mingw32-make.exe cmTC_838da/fast && C:/mingw-w64/x86_64-8.1.0-win32-seh-rt_v6-rev0/mingw64/bin/mingw32-make.exe -f CMakeFiles\cmTC_838da.dir\build.make CMakeFiles/cmTC_838da.dir/build
mingw32-make.exe[1]: Entering directory 'C:/Users/pball/git/bchest/build/CMakeFiles/CMakeTmp'
Building CXX object CMakeFiles/cmTC_838da.dir/testCXXCompiler.cxx.obj
C:\PROGRA~1\LLVM\bin\CLANG_~1.EXE -g -Xclang -gcodeview -O0 -D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd -o CMakeFiles\cmTC_838da.dir\testCXXCompiler.cxx.obj -c C:\Users\pball\git\bchest\build\CMakeFiles\CMakeTmp\testCXXCompiler.cxx
Linking CXX executable cmTC_838da.exe
"C:\Program Files\CMake\bin\cmake.exe" -E cmake_link_script CMakeFiles\cmTC_838da.dir\link.txt --verbose=1
C:\PROGRA~1\LLVM\bin\CLANG_~1.EXE -fuse-ld=lld-link -nostartfiles -nostdlib -g -Xclang -gcodeview -O0 -D_DEBUG -D_DLL -D_MT -Xclang --dependent-lib=msvcrtd #CMakeFiles\cmTC_838da.dir\objects1.rsp -o cmTC_838da.exe -Xlinker /implib:cmTC_838da.lib -Xlinker /pdb:C:\Users\pball\git\bchest\build\CMakeFiles\CMakeTmp\cmTC_838da.pdb -Xlinker /version:0.0 #CMakeFiles\cmTC_838da.dir\linklibs.rsp
lld-link: error: could not open 'kernel32.lib': no such file or directory
lld-link: error: could not open 'user32.lib': no such file or directory
lld-link: error: could not open 'gdi32.lib': no such file or directory
lld-link: error: could not open 'winspool.lib': no such file or directory
lld-link: error: could not open 'shell32.lib': no such file or directory
lld-link: error: could not open 'ole32.lib': no such file or directory
lld-link: error: could not open 'oleaut32.lib': no such file or directory
lld-link: error: could not open 'uuid.lib': no such file or directory
lld-link: error: could not open 'comdlg32.lib': no such file or directory
lld-link: error: could not open 'advapi32.lib': no such file or directory
lld-link: error: could not open 'oldnames.lib': no such file or directory
lld-link: error: could not open 'msvcrtd.lib': no such file or directory
CLANG_~1: error: linker command failed with exit code 1 (use -v to see invocation)
mingw32-make.exe[1]: *** [CMakeFiles\cmTC_838da.dir\build.make:88: cmTC_838da.exe] Error 1
mingw32-make.exe[1]: Leaving directory 'C:/Users/pball/git/bchest/build/CMakeFiles/CMakeTmp'
mingw32-make.exe: *** [Makefile:120: cmTC_838da/fast] Error 2
This is a freshly installed Windows 10 PC. It has no Visual Studio nor any Microsoft development tool installed on it. If possible I would prefer not having to install the Visual Studio for example to get the msvcrtd.lib. I am using VS Code at the moment, but this should be independent of the IDE being used.
My question is, what exactly do I have to install apart from LLVM, CMake and MinGW to make my first simple C++ project to build?
You are missing the libraries in the linker flag. These libraries may be found in the following location:
C:\Program Files (x86)\Windows Kits\10\Lib\10.0.17134.0\um\x86
The exact path on your system may vary depending on the OS version etc., but you get the idea i believe. After finding the location you can add the path to the compiler flag in the CMakeLists.txt file e.g.,
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Xlinker /libpath:path_to_library")
See related answers:
https://software.intel.com/en-us/forums/intel-fortran-compiler/topic/784047
https://stackoverflow.com/a/48576249/811335
How /libpath flag is used:
https://learn.microsoft.com/en-us/cpp/build/reference/libpath-additional-libpath?view=vs-2019
To force Clang to use its own libraries instead of MSVC's, add "-target x86_64-w64-mingw32" to CMAKE_C(XX)_FLAGS.
Beware: you have to do this before CMake identifies the compiler, e.g. either before the first C or C++ project definition in CMake (e.g. before the project() call):
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -target x86_64-w64-mingw32")
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -target x86_64-w64-mingw32")
project(MyProject ...)
Alternatively, you can pass it with "-D" to CMake on the command line.
Tested with clang 10.0
If I remember correctly, Clang attempts to use MSVC's standard library on Windows by default, since Clang's own standard library doesn't work on Windows yet.
If you don't have MSVC installed, this causes problems.
The easiest solution is to install MSYS2 and use MSYS2's patched Clang, which uses GCC's libraries by default. As a nice bonus, MSYS2 also comes with an up-to-date GCC version.
Alternatively, you can use -target flag to tell Clang to use GCC's libraries. If I remember correctly, this is done by adding -target x86_64-w64-mingw32 to both compiler and linker flags.
(If it doesn't work, try -target x86_64-w64-windows-gnu, I can't remember which one it is. Replace x86_64 with i686 if you're using a 32-bit compiler.)
Your Clang compiler is probably built to target the MSVC ABI. If I try your scenario, this is my error message:
-- The CXX compiler identification is Clang 9.0.0
CMake Error at C:/Program Files/CMake/share/cmake-3.13/Modules/CMakeDetermineCompilerId.cmake:802 (message): The Clang compiler tool
"C:/Program Files/LLVM/bin/clang++"
targets the MSVC ABI but has a GNU-like command-line interface. This is not supported. Use 'clang-cl' instead, e.g. by setting 'CXX=clang-cl' in the environment. Furthermore, use the MSVC command-line environment.
This was with CMake 3.13 and LLVM 9.0, and trying to use -G "MinGW Makefiles". It works using this:
SET CXX="C:/Program Files/LLVM/bin/clang-cl.exe"
cmake -G "NMake Makefiles" ..
You probably don't need to install Visual Studio, but if you want to use nmake and the MSVC libraries, you definitely need the Windows 10 SDK which is a big download, and it will be installed as well if you decide to install Visual Studio.
On the other hand, The problem seems to be related to the CMake 3.16 version. The above unsucessful tests were made with cmake 3.13, but after that I've upgraded to CMake 3.15.5 and it works perfectly. Here are the exact versions:
> cmake -version
cmake version 3.15.5
> clang++ --version
clang version 9.0.0 (tags/RELEASE_900/final)
Target: x86_64-pc-windows-msvc
Thread model: posix
InstalledDir: C:\Program Files\LLVM\bin
My build.cmd script:
SET CXX="C:/Program Files/LLVM/bin/clang++.exe"
cmake -G "MinGW Makefiles" ..
So the problem may be with your CMake version, or the MinGW libraries, as your error message is suggesting.
I'm trying to compile my project using cmake with mingw but getting error:
cmake -G "MinGW Makefiles" ../
-- The C compiler identification is GNU 6.3.0
-- The CXX compiler identification is GNU 6.3.0
-- Check for working C compiler: D:/mingw/bin/gcc.exe
-- Check for working C compiler: D:/mingw/bin/gcc.exe -- broken
CMake Error at C:/Program Files/CMake/share/cmake-3.9/Modules/CMakeTestCCompiler.cmake:51 (message):
The C compiler "D:/mingw/bin/gcc.exe" is not able to compile a simple test
program.
Where is the problem?
Sometimes there are problems if the directory has any spaces in it's name, like yours has in "Program files". Try to copy the sdk to another location without spaces and see what happens
So I tried to install clang + cmake to compile a simple C++ program and I'm getting the following error:
-- The C compiler identification is GNU 4.8.3
-- The CXX compiler identification is Clang 3.5.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working CXX compiler: /usr/local/bin/clang++
-- Check for working CXX compiler: /usr/local/bin/clang++ -- broken
CMake Error at /usr/share/cmake/Modules/CMakeTestCXXCompiler.cmake:54 (message):
The C++ compiler "/usr/local/bin/clang++" is not able to compile a simple
test program.
It fails with the following output:
Change Dir: /home/jtcwang/tmp/CMake/CMake/CMakeFiles/CMakeTmp
Run Build Command:/usr/bin/gmake "cmTryCompileExec697180971/fast"
/usr/bin/gmake -f CMakeFiles/cmTryCompileExec697180971.dir/build.make
CMakeFiles/cmTryCompileExec697180971.dir/build
gmake[1]: Entering directory
`/home/jtcwang/tmp/CMake/CMake/CMakeFiles/CMakeTmp'
/usr/bin/cmake -E cmake_progress_report
/home/jtcwang/tmp/CMake/CMake/CMakeFiles/CMakeTmp/CMakeFiles 1
Building CXX object
CMakeFiles/cmTryCompileExec697180971.dir/testCXXCompiler.cxx.o
/usr/local/bin/clang++ -o
CMakeFiles/cmTryCompileExec697180971.dir/testCXXCompiler.cxx.o -c
/home/jtcwang/tmp/CMake/CMake/CMakeFiles/CMakeTmp/testCXXCompiler.cxx
Linking CXX executable cmTryCompileExec697180971
/usr/bin/cmake -E cmake_link_script
CMakeFiles/cmTryCompileExec697180971.dir/link.txt --verbose=1
/usr/local/bin/clang++
CMakeFiles/cmTryCompileExec697180971.dir/testCXXCompiler.cxx.o -o
cmTryCompileExec697180971 -rdynamic
/usr/bin/ld: cannot find -lstdc++
clang: error: linker command failed with exit code 1 (use -v to see
invocation)
gmake[1]: Leaving directory
`/home/jtcwang/tmp/CMake/CMake/CMakeFiles/CMakeTmp'
gmake[1]: *** [cmTryCompileExec697180971] Error 1
gmake: *** [cmTryCompileExec697180971/fast] Error 2
It's not even compiling my program because it fails to compile a test program.
Looks like the important line is here:
/usr/bin/ld: cannot find -lstdc++
However, I have checked that libstdc++ is installed and up to date, so at this point I'm quite lost.
Other things I've tried:
Using prebuilt binaries instead of sudo yum install clang
remove and reinstall
Tried clang++ hello.cpp (hello world program). It says <iostreams> is not found. Is clang missing a standard library? EDIT: changing to <iostream> gives me the same linker error above.
I'm not familiar with the clang, cmake and C++ scene in general, so I'd appreciate any pointers. Thanks!
You need the development libraries and headers for C++ library, try
yum install libstdc++-devel
Your /home/gnu/bin/c++ seem to require additional flag to link things properly and CMake doesn't know about that.
To use /usr/bin/c++ as your compiler run cmake with -DCMAKE_CXX_COMPILER=/usr/bin/c++.
Also, CMAKE_PREFIX_PATH variable sets destination dir where your project' files should be installed. It has nothing to do with CMake installation prefix and CMake itself already know this.