C/C++ Support: Can this be used to help generate the c_cpp_properties.json configuration file?

[CMCDragonkai]

Is your feature request related to a problem? Please describe.

The c_cpp_properties.json configuration file is necessary for intellisense to work for C/C++ files.

For example right now I have to manually configure it like:

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}/**",
                "/nix/store/zl4bvsqfxyx5vn9bbhnrmbmpfvzqj4gd-nodejs-16.14.2/include/**"
            ],
            "defines": [],
            "compilerPath": "/nix/store/58pwclg9yr437h0pfgrnbd0jis8fqasd-gcc-wrapper-11.2.0/bin/gcc",
            "cStandard": "c99",
            "cppStandard": "c++17",
            "intelliSenseMode": "linux-gcc-x64"
        }
    ],
    "version": 4
}

In particular both the compilerPath and includePath I had to add in manually.

My shell.nix brings in $NIX_CFLAGS_COMPILE and $NIX_LDFLAGS which shows us all the include paths we need.

Describe the solution you'd like

It would be nice if nix-env-selector could acquire this information, or allow us to configure it to acquire this information from the relevant nix environment, then provide us a way to reference these "variables" from the shell environment for other VScode extensions such as the C/C++ extension. That would be most flexible way.

I could imagine doing something like:

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}/**",
                "${nixEnv:...}"
            ],
            "defines": [],
            "compilerPath": "${nixEnv:NIX_CC}",
            "cStandard": "c99",
            "cppStandard": "c++17",
            "intelliSenseMode": "linux-gcc-x64"
        }
    ],
    "version": 4
}

I'm not familiar with how vscode extensions work, and how to apply these variables to vscode dynamically, but it would greatly simplify the usage of nix-shell related environment configuration with other extensions and other languages.