Language-specific default defines

[cD1rtX3]

Type: Feature Request

Because of the lackluster support for C23, I have these default defines in my settings.json:

"C_Cpp.default.defines": [
    "constexpr=const",
    "_BitInt(N)=int",
],

However, that "constexpr=const" definition makes C++ code explode, since constexpr means quite a bit more in C++. I would like to be able to enable these definitions in specifically C code and not C++ code.

Extension version: 1.31.4
VS Code version: Code 1.115.0 (41dd792b5e652393e7787322889ed5fdc58bd75b, 2026-04-07T22:04:57Z)
OS version: Linux x64 6.8.0-106-generic
Modes:

[sean-mcmanus]

@cD1rtX3 This is already supported via

            "[c]": {
                "C_Cpp.default.defines": [
                    "constexpr=const",
                    "_BitInt(N)=int",
                ],
            }

Is that not working?

[sean-mcmanus]

@cD1rtX3 I tried it out -- it gives error "This setting cannot be applied because it is not registered as language override setting.".

[bobbrow]

@sean-mcmanus yeah, the standard configurations are not able to change per file like that. (compile_commands.json and config provider can, but this isn't using either of those)