How to configure a complex project with CMake Tools plugin? - cmake

Question

I am trying to configure vscode to develop llvm/mlir project with the CMake Tools plugin.
The project is big and requires passing this configuration to the command-line:
git clone https://github.com/llvm/llvm-project.git
mkdir llvm-project/build
cd llvm-project/build
cmake -G Ninja ../llvm \
-DLLVM_ENABLE_PROJECTS=mlir \
-DLLVM_BUILD_EXAMPLES=ON \
-DLLVM_TARGETS_TO_BUILD="X86;NVPTX;AMDGPU" \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_ASSERTIONS=ON \
-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DLLVM_ENABLE_LLD=ON \
-DPYTHON_EXECUTABLE=python3
I tried to add this information into .vscode/settings.json:
{
"cmake.sourceDirectory": "${workspaceFolder}/llvm",
"cmake.configureArgs": [
"-DLLVM_ENABLE_PROJECTS=mlir",
"-DLLVM_BUILD_EXAMPLES=ON",
"-DLLVM_TARGETS_TO_BUILD='X86;NVPTX;AMDGPU'",
"-DCMAKE_BUILD_TYPE=Release",
"-DLLVM_ENABLE_ASSERTIONS=ON",
"-DCMAKE_C_COMPILER=clang",
"-DCMAKE_CXX_COMPILER=clang++",
"-DLLVM_ENABLE_LLD=ON",
"-DPYTHON_EXECUTABLE=python3",
]
}
But the configuration is not successful and it appears that my arguments were not detected.
[main] Configuring folder: llvm-project
[proc] Executing command: /usr/bin/cmake --no-warn-unused-cli -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_BUILD_TYPE:STRING=Debug -DCMAKE_C_COMPILER:FILEPATH=/bin/clang-10 -DCMAKE_CXX_COMPILER:FILEPATH=/bin/clang++-10 -H${HOME}/Development/mlir/llvm-project/mlir -B${HOME}/Development/mlir/llvm-project/build -G Ninja
[cmake] Not searching for unused variables given on the command line.
[cmake] CMake Warning (dev) in CMakeLists.txt:
[cmake] No project() command is present. The top-level CMakeLists.txt file must
[cmake] contain a literal, direct call to the project() command. Add a line of
[cmake] code such as
[cmake]
[cmake] project(ProjectName)
[cmake]
[cmake] near the top of the file, but after cmake_minimum_required().
[cmake]
[cmake] CMake is pretending there is a "project(Project)" command on the first
[cmake] line.
[cmake] This warning is for project developers. Use -Wno-dev to suppress it.
[cmake]
[cmake] -- The C compiler identification is Clang 10.0.0
[cmake] -- The CXX compiler identification is Clang 10.0.0
[cmake] -- Check for working C compiler: /bin/clang-10
[cmake] -- Check for working C compiler: /bin/clang-10 -- works
[cmake] -- Detecting C compiler ABI info
[cmake] -- Detecting C compiler ABI info - done
[cmake] -- Detecting C compile features
[cmake] -- Detecting C compile features - done
[cmake] -- Check for working CXX compiler: /bin/clang++-10
[cmake] -- Check for working CXX compiler: /bin/clang++-10 -- works
[cmake] -- Detecting CXX compiler ABI info
[cmake] -- Detecting CXX compiler ABI info - done
[cmake] -- Detecting CXX compile features
[cmake] -- Detecting CXX compile features - done
[cmake] CMake Warning (dev) at CMakeLists.txt:26 (if):
[cmake] Policy CMP0057 is not set: Support new IN_LIST if() operator. Run "cmake
[cmake] --help-policy CMP0057" for policy details. Use the cmake_policy command to
[cmake] set the policy and suppress this warning.
[cmake]
[cmake] IN_LIST will be interpreted as an operator when the policy is set to NEW.
[cmake] Since the policy is not set the OLD behavior will be used.
[cmake] This warning is for project developers. Use -Wno-dev to suppress it.
[cmake]
[cmake] CMake Error at CMakeLists.txt:26 (if):
[cmake] if given arguments:
[cmake]
[cmake] "NVPTX" "IN_LIST" "LLVM_TARGETS_TO_BUILD"
[cmake]
[cmake] Unknown arguments specified
[cmake]
[cmake]
[cmake] CMake Warning (dev) in CMakeLists.txt:
[cmake] No cmake_minimum_required command is present. A line of code such as
[cmake]
[cmake] cmake_minimum_required(VERSION 3.16)
[cmake]
[cmake] should be added at the top of the file. The version specified may be lower
[cmake] if you wish to support older CMake versions for this project. For more
[cmake] information run "cmake --help-policy CMP0000".
[cmake] This warning is for project developers. Use -Wno-dev to suppress it.
[cmake]
[cmake] -- Configuring incomplete, errors occurred!
[cmake] See also "${HOME}/Development/mlir/llvm-project/build/CMakeFiles/CMakeOutput.log".
How can I transform the configuration line into something that the CMake Tools plugin can understand?
EDIT: Adjusted the error message
EDIT2:
Modifying .vscode/settings.json to use cmake.configureSettings did not solve the problem:
{
"cmake.sourceDirectory": "${workspaceFolder}/llvm",
"cmake.configureSettings": {
"LLVM_ENABLE_PROJECTS" : "mlir",
"LLVM_BUILD_EXAMPLES" : "ON",
"LLVM_TARGETS_TO_BUILD" : "\"X86;NVPTX;AMDGPU\"",
"CMAKE_BUILD_TYPE" : "Release",
"LLVM_ENABLE_ASSERTIONS" : "ON",
"CMAKE_C_COMPILER" : "clang",
"CMAKE_CXX_COMPILER" : "clang++",
"LLVM_ENABLE_LLD" : "ON",
"PYTHON_EXECUTABLE" : "python3",
}
}

Answer 1

I found the problem / possible bug.
It appears that vscode and CMake Tools plugin caches some files and even if you delete the build folder (that holds the CMakeCache.txt) the project does not use new configurations parameters modified on .vscode/settings.json.
So, to get my project working.
I added this information to .vscode/seetings.json:
{
"cmake.sourceDirectory": "${workspaceFolder}/llvm",
"cmake.configureSettings": {
"LLVM_ENABLE_PROJECTS" : "mlir",
"LLVM_BUILD_EXAMPLES" : "ON",
"LLVM_TARGETS_TO_BUILD" : "X86;NVPTX;AMDGPU",
"CMAKE_BUILD_TYPE" : "Release",
"LLVM_ENABLE_ASSERTIONS" : "ON",
"CMAKE_C_COMPILER" : "clang",
"CMAKE_CXX_COMPILER" : "clang++",
"LLVM_ENABLE_LLD" : "ON",
"PYTHON_EXECUTABLE" : "python3",
}
}
Closed vscode
Deleted the build folder
Opened vscode
Answered yes to: "Would you like to configure project 'llvm-project'?"
And the configuration was successful.
Now you can select your targets using vscode.
Unfortunately it appears that every time vscode is opened the CMake plugin triggers a new configuration, but it is probably better to address this issue in another question/forum.

Answer 2

In .vscode/seetings.json, use an array syntax to specify multiple options instead. For example,
{
"cmake.sourceDirectory": "${workspaceFolder}/llvm",
"cmake.configureSettings": {
//...
"LLVM_TARGETS_TO_BUILD" : ["X86", "NVPTX", "AMDGPU"],
//...
}
}