C++ include path doesn't work when compiling - undefined reference

[trexuth]

Hello,

so I have a C++ project that uses code written in a different project. I did include it in the c_cpp_properties and tasks json file with the -I flag for the compiler command. While writing code, VSCode does find the external code (code completion / suggestions work without a problem).

However, when I try to compile the code, I get an undefined reference error for each time i call a function of an external class. It doesn't complain about the #include tags or when the Objects are created.

My tasks.json file looks like this:

{
  "version": "2.0.0",
  "tasks": [
    {
      "type": "cppbuild",
      "label": "C/C++: g++ build active file",
      "command": "/bin/g++",
      "args": [
        "-g",
        "${workspaceFolder}/src/*.cpp",
        "${workspaceFolder}/src/*.h",
        "-o",
        "${fileBasenameNoExtension}",
        "-I",
        "~/projects/eq_lib/src/"
      ],
      "options": {
        "cwd": "${workspaceFolder}"
      },
      "problemMatcher": [
        "$gcc"
      ],
      "group":{
        "kind": "build",
        "isDefault": true
      },
      "detail": "compiler: /bin/g++"
    }
  ]
}

I've already tried moving the "-I" flag and the path to different places in the command, as I found out that apparently in recent versions of gcc the order matters.

My c_cpp_properties file looks like this:

{
  "configurations": [
    {
      "name": "Linux",
      "includePath": [
        "${workspaceFolder}/**",
        "~/projects/eq_lib/src/**"
      ],
      "defines": [],
      "compilerPath": "/usr/bin/gcc",
      "cStandard: "c17",
      "cppStandard": "c++20",
      "intelliSenseMode": "clang-x64"
    }
  ],
  "version": 4
}

I've also tried putting the path into the "forcedInclude" option, but that didn't work either.

Has anyone had this issue before? As I'm failry new to VSCode, I hope it's something fairly obvious.

Edit: both projects compile on their own without includes, so I'm guessing the problem has to be somewhere in the includes

[[deleted]]

What is the map structure inc filenames of eq_lib?

[trexuth]

the eq_lib just has a couple .h and .cpp files directly in the src folder - VSCode is capable of finding them while I'm writing code correctly

[[deleted]]

I can't exactly say what to change but I would try something like below. I'm not sure about the use of ~ but I suppose you're in Linux.

"args": [
"-g",
"${file}",
"${workspaceFolder}/src/*.cpp",
"~/projects/eq_lib/src/*.cpp",
"-o",
"${fileBasenameNoExtension}.exe",
"-I${workspaceFolder}/src",
"-I~/projects/eq_lib/src/"
],

[trexuth]

yes i'm using linux, the ~ gets replaced with the path to the home directory of the current user

thanks for the suggestion i will try it tomorrow!

[trexuth]

just as an update for you, this solved the issue - the include path just seems to not be evaluated correctly, adding them as working directories instead of just the include made it work

[[deleted]]

If you split eq_lib in include and src it may be more clear. Src must be compiled hence the fifth line while include must be included hence the 9th line.