Home

Info

• CMake pull request: compdb: mergedCompileCommands for CMake subprojects
• cpptools issue: Support multiple compile commands files per project

CMake Tools solution is limited

• must use CMake as the build system
• must use VSCode's CMake Tools to build your project (running cmake .., make on your project will not cause CMake Tools to merge the generated db files)

Settings Implementation Suggestion:

• define the following entries in .vscode/settings.json:

    // already implemented
    "C_Cpp.default.compileCommands": "${workspaceFolder}/build/merged_compile_commands.json",
    // new
    "C_cpp.mergeCompileCommands": { 
        "source": [
            "${workspaceFolder}/build/proj1/compile_commands.json",
            "${workspaceFolder}/build/proj2/compile_commands.json",
        ],
        "destination": "${workspaceFolder}/build/merged_compile_commands.json"
    },

• "C_Cpp.default.compileCommands" is not changed to accept a list for backwards compatibility, specifying multiple sources will not inform where the destination file should be saved.
• "C_Cpp.default.compileCommands" can also be ignored and overridden to C_cpp.mergeCompileCommands.destination (not mandatory)

Why not use paths already defined in .vscode/c_cpp_properties.json configurations?

• paths defined in c_cpp_properties.json are specific for a configuration, each maybe having one compileCommands path.
• C_Cpp.default.compileCommands from .vscode/settings.json is only used if the selected configuration didn't define a compileCommands.
• defining compileCommands in configurations will mask the single merged file as some configuration is always selected.

Why are glob patterns not supported?

• the CMake Tools extension (probably) supports glob patterns without consuming heavy CPU resources as it only tries to search for compile_commands.json files when a a target build is finished succesfully. (one time per build)
• the C/C++ extension doesn't know when a build is started (or finished), so it actively observes for changes in the user-defined compileCommands files.
  • continuously stating multiple directories and subdirectories might create a non-negligible and persistent CPU load.
  • continuously stating build directories will create many false positive events during compilation processes that take more than a few seconds.