cpptools doesn't parse qcc system include arguments from compile_commands.json

[ABee81]

Environment

• OS and Version: Ubuntu 22.04.5 LTS
• VS Code Version: 1.99.3
• C/C++ Extension Version: 1.25.3
• If using SSH remote, specify OS of remote machine: No remote

Bug Summary and Steps to Reproduce

Bug Summary:
For the following Test_Workspace:
Test_Workspace/

• build/qnx710
  • compile_commands.json
  • ...
• inc/
  • myInclude.h
• cmake/
  • toolchains/
    • qnx710-arm-toolchain-conan.cmake
• main.c
• CMakeLists.txt
• conanfile.py

After executing the build, CMake generates compile_commands.json file inside build/qnx710 folder. When adding compile_commands.json path to the c_cpp_properties.json configuration of the workspace, the system includes in with the format "-Wp,-isystem,/home//Test_Workspace/inc" are ignored/not parsed correctly by cpptools. Navigating to the header files in the system include folder is not working, error squiggles and the message:
#include errors detected. Consider updating your compile_commands.json or includePath. Squiggles are disabled for this translation unit (/home/Test_Workspace/main.c).C/C++(1696)

Steps to reproduce:

1. Create a compile_commands.json which includes -Wp,-isystem,/home//Test_Workspace/inc
2. Add path to this compile_commands.json to the c_cpp_properties.json
3. Try CTRL+LeftMouseclick on an system include
4. See error

Expected behavior:
cpptools parsed sytem include path correctly and navigating to the header files in the system include path works without errors. No error squiggles should be shown.

Configuration and Logs

{
    "configurations": [
        {
            "name": "neutrino_armv8_qcc83_debug",
            "compilerPath": "~/.conan/data/<path-to-toolchain-package>/host/linux/x86_64/usr/bin/qcc",
            "cStandard": "c11",
            "cppStandard": "c++14",
            "compileCommands": [
                "build/qnx710/compile_commands.json"
            ],
            "includePath": [
                "${workspaceFolder}/**"
            ]
        }
    ],
    "version": 4
}

-------- Diagnostics - 4/29/2025, 11:29:15 AM
Version: 1.25.3
Current Configuration:
{
    "name": "neutrino_armv8_qcc83_bbnxp_debug",
    "compilerPath": "/home/<username>/.conan/<path-to-toolchain-package>/host/linux/x86_64/usr/bin/qcc",
    "cStandard": "c11",
    "cppStandard": "c++14",
    "compileCommands": [
        "/home/<username>/Test_Workspace/build/qnx710/compile_commands.json"
    ],
    "includePath": [
        "/home/<username>/Test_Workspace/**"
    ],
    "compilerPathIsExplicit": true,
    "cStandardIsExplicit": true,
    "cppStandardIsExplicit": true,
    "intelliSenseModeIsExplicit": false,
    "recursiveIncludesReduceIsExplicit": true,
    "recursiveIncludesPriorityIsExplicit": true,
    "recursiveIncludesOrderIsExplicit": true,
    "compilerPathInCppPropertiesJson": "~/.conan/<path-to-toolchain-package>/host/linux/x86_64/usr/bin/qcc",
    "compileCommandsInCppPropertiesJson": [
        "build/qnx710/compile_commands.json"
    ],
    "mergeConfigurations": false,
    "recursiveIncludes": {
        "reduce": "default",
        "priority": "afterSystemIncludes",
        "order": "depthFirst"
    },
    "browse": {
        "limitSymbolsToIncludedHeaders": true
    }
}
Additional Tracked Settings:
{
    "editorTabSize": 4,
    "editorInsertSpaces": true,
    "editorAutoClosingBrackets": "languageDefined",
    "filesEncoding": "utf8",
    "filesAssociations": {
        "stdio.h": "c"
    },
    "filesExclude": {
        "**/.git": true,
        "**/.svn": true,
        "**/.hg": true,
        "**/.DS_Store": true,
        "**/Thumbs.db": true
    },
    "filesAutoSaveAfterDelay": false,
    "editorInlayHintsEnabled": true,
    "editorParameterHintsEnabled": true,
    "searchExclude": {
        "**/node_modules": true,
        "**/bower_components": true,
        "**/*.code-search": true
    },
    "workbenchSettingsEditor": "ui"
}
cpptools version (native): 1.25.3.0
Current database path: /home/<username>/.cache/vscode-cpptools/15cea5a343f9a039922a513837cff81f/.browse.VC.db
Translation Unit Mappings:
[ /home/<username>/Test_Workspace/main.c - source TU]:
Translation Unit Configurations:
[ /home/<username>/Test_Workspace/main.c ]
    Process ID: 17277
    Memory Usage: 20 MB
    Compiler Path: /home/<username>/.conan/<path-to-toolchain-package>/host/linux/x86_64/usr/bin/qcc
    Include paths:
        include: /home/<username>/Test_Workspace/build/qnx710/{USER_DEFINED}-L{USER_DEFINED}
        system include: /home/<username>/.conan/<additional-system-includes>/target/qnx7/usr/include
        system include: /home/<username>/.conan/<additional-system-includes>/host/linux/x86_64/usr/lib/gcc/aarch64-unknown-nto-qnx7.1.0/8.3.0/include
    Defines:
        _FORTIFY_SOURCE=2
        _QNX_SOURCE
        _DEBUG
    Standard Version: c11
    IntelliSense Mode: linux-gcc-arm64
    Other Flags:
        --gcc
        --gnu_version=80300
    compile_commands.json entry:
        directory: /home/<username>/Test_Workspace/build/qnx710
        file: /home/<username>/Test_Workspace/main.c
        command: /home/<username>/.conan/<path-to-toolchain-package>host/linux/x86_64/usr/bin/qcc  -Wp,-isystem,/home/<username>/Test_Workspace/inc -V,gcc_ntoaarch64le -fno-common -fno-builtin -fno-aggressive-loop-optimizations -fPIC -fPIE -D_FORTIFY_SOURCE=2 -fstack-protector-strong -std=c11 -D_QNX_SOURCE -I{USER_DEFINED}-L{USER_DEFINED} -ffunction-sections -fdata-sections -g -O2 -D_DEBUG -o CMakeFiles/hello-world.dir/main.c.o -c /home/<username>/Test_Workspace/main.c
Total Memory Usage: 20 MB
Browse Paths from compile_commands.json, from workspace folder: /home/<username>/Test_Workspace
    /home/<username>/.conan/<additional-system-includes>/host/linux/x86_64/usr/lib/gcc/aarch64-unknown-nto-qnx7.1.0/8.3.0/include
    /home/<username>/.conan/<additional-system-includes>/host/linux/x86_64/usr/lib/gcc/x86_64-pc-nto-qnx7.1.0/8.3.0/include
    /home/<username>/.conan/<additional-system-includes>/target/qnx7/usr/include
    /home/<username>/.conan/<additional-system-includes>/target/qnx7/usr/include/c++/v1
    /home/<username>/Test_Workspace
    /home/<username>/Test_Workspace/build/qnx710
    /home/<username>/Test_Workspace/build/qnx710/{USER_DEFINED}-L{USER_DEFINED}

------- Workspace parsing diagnostics -------
Number of files discovered (not excluded): 2873
Number of files parsed: 217

Other Extensions

No response

Additional context

No response

[sean-mcmanus]

@ABee81 We currently only support -isystem and not -Wp,-isystem (which I have never seen before).

[ABee81]

@sean-mcmanus Thanks for you quick answer! I also never saw it before, but In QNX SDP Documentation I could find some additional information: the -Wp argument of qcc passes the following arguments to the preprocessor.

If its possible it would be great to have this as a feature, up to then we will be using a script to replace -Wp,-isystem with just -isystem

[ABee81]

@sean-mcmanus after more deeper analysis into the issue I think it is not a cpptools issue. I have opened an issue for CMake (https://gitlab.kitware.com/cmake/cmake/-/issues/26912). Depending on response of Kitware/CMake, this feature might not be needed