Unable to set a header path as -isystem in clang-tidy?

[arghness]

Environment

• OS and Version: Ubuntu 22.04
• VS Code Version: 1.80.1
• C/C++ Extension Version: 1.16.3
• If using SSH remote, specify OS of remote machine: Rocky Linux 8

Bug Summary and Steps to Reproduce

Bug Summary:

I am using the CMake extension and a custom build of Boost installed to a separate directory under /opt. CMake is building a compile_commands.json that adds it as -isystem . clang-tidy is adding it as -I , which is triggering various errors that I don't care about.

I've tried setting compileCommands "C_Cpp.default.compileCommands" and "C_Cpp.codeAnalysis.clangTidy.useBuildPath": true but then I get other basic include errors (e.g. "'stddef.h' file not found"), so I'm not sure if this fixes my issue or not.

It looks like "C_Cpp.codeAnalysis.clangTidy.args" may only apply to arguments before the filename being tested, so I haven't been able to see if I can override the -I with a -isystem.

Configuration and Logs

C_Cpp settings (taken from workspace file, as I do not have a c_cpp_properties.json):

"C_Cpp.clang_format_style": "file:${workspaceFolder}/XXXX/vscode/.clang-format",
"C_Cpp.codeAnalysis.clangTidy.args": [
	"--config-file=${workspaceFolder}/XXXX/vscode/.clang-tidy"
],
"C_Cpp.codeAnalysis.exclude": {
	// Various paths of 3rd party generated code.
},
"C_Cpp.default.configurationProvider": "ms-vscode.cmake-tools",
"C_Cpp.vcpkg.enabled": false,


-------- Diagnostics - 7/17/2023, 1:29:49 PM
Version: 1.16.3
Current Configuration:
{
    "name": "Linux",
    "includePath": [
        "XXXX/master/**"
    ],
    "defines": [],
    "compilerPath": "/usr/bin/gcc",
    "cStandard": "c17",
    "cppStandard": "gnu++14",
    "intelliSenseMode": "linux-gcc-x64",
    "compilerPathInCppPropertiesJson": "/usr/bin/gcc",
    "intelliSenseModeIsExplicit": false,
    "cStandardIsExplicit": false,
    "cppStandardIsExplicit": false,
    "mergeConfigurations": false,
    "compilerPathIsExplicit": false,
    "configurationProvider": "ms-vscode.cmake-tools",
    "browse": {
        "path": [
            "${workspaceFolder}/**"
        ],
        "limitSymbolsToIncludedHeaders": true
    }
}
Custom browse configuration: 
{
    "browsePath": [
        "XXXX/obj/CMakeFiles",
        ....
        "/opt/XXXX/XXXX-boost/include",
        ....
    ],
    "compilerPath": "/opt/rh/gcc-toolset-11/root/usr/bin/c++",
    "compilerArgs": [],
    "compilerFragments": [
        "-g",
        "-Wall",
        "-Wextra",
        "-Werror",
        "-Wno-deprecated-copy",
        "-std=gnu++17"
    ]
}
Custom configurations:
[ XXXX/core/tests/layer_decoder.cpp ]
{
    "includePath": [
        "XXXX/include",
        .... 
        "/opt/XXXX/XXXX-boost/include"
    ],
    "defines": [
        "BOOST_THREAD_DYN_LINK",
        "BOOST_THREAD_NO_LIB",
        "BOOST_UNIT_TEST_FRAMEWORK_DYN_LINK",
        "BOOST_UNIT_TEST_FRAMEWORK_NO_LIB",
        "FMT_SHARED"
    ],
    "compilerPath": "/opt/rh/gcc-toolset-11/root/usr/bin/c++",
    "compilerArgs": [],
    "compilerFragments": [
        "-g",
        "-Wall",
        "-Wextra",
        "-Werror",
        "-Wno-deprecated-copy",
        "-pthread",
        "-std=gnu++17"
    ]
}
cpptools version (native): 1.16.3.0
Translation Unit Mappings:
[ XXXX/core/tests/layer_decoder.cpp ]:
    XXXX/core/tests/layer_decoder.cpp
Translation Unit Configurations:
[ XXXX/core/tests/layer_decoder.cpp ]:
    Process ID: 3579914
    Memory Usage: 684 MB
    Compiler Path: /opt/rh/gcc-toolset-11/root/usr/bin/c++
    Includes:
        ....
        /opt/XXXX/XXXX-boost/include
        ....
        /opt/rh/gcc-toolset-11/root/usr/include/c++/11
        /opt/rh/gcc-toolset-11/root/usr/include/c++/11/x86_64-redhat-linux
        /opt/rh/gcc-toolset-11/root/usr/include/c++/11/backward
        /opt/rh/gcc-toolset-11/root/usr/lib/gcc/x86_64-redhat-linux/11/include
        /usr/local/include
        /opt/rh/gcc-toolset-11/root/usr/include
        /usr/include
    Defines:
        BOOST_THREAD_DYN_LINK
        BOOST_THREAD_NO_LIB
        BOOST_UNIT_TEST_FRAMEWORK_DYN_LINK
        BOOST_UNIT_TEST_FRAMEWORK_NO_LIB
        FMT_SHARED
    Standard Version: c++17
    IntelliSense Mode: linux-gcc-x64
    Other Flags:
        --g++
        --gnu_version=110201
Total Memory Usage: 684 MB

------- Workspace parsing diagnostics -------
Number of files discovered (not excluded): 24486
Number of files parsed: 9734

Other Extensions

ms-vscode.cmake-tools

Additional context

No response