identifier "false" is undefined

[winstxnhdw]

I have Clang 16 installed and I can compile my code just fine, but intellisense says that my booleans are undefined.

{
  "configurations": [
    {
      "name": "Linux",
      "includePath": ["/usr/lib/clang/16/**", "${workspaceFolder}/**"],
      "defines": [],
      "compilerPath": "/sbin/clang-16",
      "intelliSenseMode": "linux-clang-x64",
      "cStandard": "c23",
      "cppStandard": "c++23"
    }
  ],
  "version": 4
}

Any ideas?

[bobbrow]

It is not recommended to add the system include path to your includePath setting. The extension should be able to determine that by querying the compiler listed in the compilerPath setting.

In the case where you're seeing this error could you run the "C/C++: Log Diagnostics" command when the affected file is visible in the editor and share the output with us?

[winstxnhdw]

Yeah, I tried both configurations. I just added that to see if it would resolve the problem (which it didn't).

-------- Diagnostics - 21/11/2023, 18:31:26
Version: 1.18.5
Current Configuration:
{
    "name": "Linux",
    "includePath": [
        "/home/winston/projects/libcs1010/**"
    ],
    "defines": [],
    "compilerPath": "/sbin/clang-16",
    "intelliSenseMode": "linux-clang-x64",
    "cStandard": "c23",
    "cppStandard": "c++23",
    "compilerPathIsExplicit": true,
    "cStandardIsExplicit": true,
    "cppStandardIsExplicit": true,
    "intelliSenseModeIsExplicit": true,
    "compilerPathInCppPropertiesJson": "/sbin/clang-16",
    "mergeConfigurations": false,
    "browse": {
        "path": [
            "/home/winston/projects/libcs1010/**",
            "${workspaceFolder}"
        ],
        "limitSymbolsToIncludedHeaders": true
    }
}
cpptools version (native): 1.18.3.0
Translation Unit Mappings:
[ /home/winston/projects/libcs1010/main.c ]:
    /home/winston/projects/libcs1010/main.c
    /home/winston/projects/libcs1010/include/cs1010.h *
Translation Unit Configurations:
[ /home/winston/projects/libcs1010/main.c ]:
    Process ID: 47182
    Memory Usage: 19 MB
    Compiler Path: /sbin/clang-16
    Includes:
        /usr/lib/clang/16/include
        /usr/local/include
        /usr/include
        /home/winston/projects/libcs1010/include
    Standard Version: c23
    IntelliSense Mode: linux-clang-x64
    Other Flags:
        --clang
        --clang_version=160006
Total Memory Usage: 19 MB

------- Workspace parsing diagnostics -------
Number of files discovered (not excluded): 22581

[bobbrow]

Ah, ok. You're using C. Support for true and false in the C23 spec has not yet been implemented by the language server. Lists of supported features per standard are linked from here: https://www.edg.com/c/features. This specific one is on row 44 of the spreadsheet for C23 feature tracking.

[winstxnhdw]

😂😂😂 and I am guessing there’s no alternative either.

[bobbrow]

Well, as a workaround, for the time being you could add "true=1" and "false=0" to the "defines" array in your c_cpp_properties.json.

[starball5]

Related on Stack Overflow: VS Code's C/C++ extension says the C23 true and false keywords are unidentified.