Setting "cmake.exportCompileCommandsFile": true does not work with CMake Presets

Brief Issue Summary

Setting "cmake.exportCompileCommandsFile": true does not work with CMake Presets.

Expected:

1. Set "cmake.exportCompileCommandsFile": true
2. -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=ON is added to the CMake configure call even when on the presets path

Platform and Versions

• Operating System: Ubuntu
• CMake Version: 3.20.2
• VSCode Version: 1.55.0
• CMake Tools Extension Version: 1.7.1
• Compiler/Toolchain: GCC 9.3.0

[hwmaier]

Ok, so this is by design. I can understand this as you want Cmake yield the same result regardless if launched from VS Code or command line. I think for users familiar with the variant/kit system transitioning to the preset system this is something with must be expressed very clearly in the documentation.

And yes, setting CMAKE_EXPORT_COMPILE_COMMANDS in the preset environment works, this is what we are presently doing:

    "configurePresets": [
        {
...
            "environment": {
                "CMAKE_EXPORT_COMPILE_COMMANDS": "ON"
            },

But I still think that exportCompileCommandsFile is a setting not for cmake itself but for the IDE controlling it so I believe cmake.exportCompileCommandsFile should flow through as it does not affect the build but allows VS Code to parse it and offer compile command for single C files.

[andreeis]

Thank you for opening this report. You can specify this in the preset as well. I just verified that it works. “cacheVariables”: { “CMAKE_EXPORT_COMPILE_COMMANDS”: “ON” }

@xisui-MSFT, I don’t see any reason why presets wouldn’t pick up from regular settings but I am not sure, please confirm if this behavior is by design or we should fix something in CMake Tools. Is the user supposed to define the above when wanting compile_commands.json or the usual setting we had should have effect even with presets on?