IntelliSense uses resolved abolute path instead of absolute path when looking up source files in compile_commands.json

[StefanHamminga]

Environment

• OS and Version: Arch Linux (rolling @ 2025-02-28)
• VS Code Version: 1.98.0
• C/C++ Extension Version: 1.24.1

Bug Summary and Steps to Reproduce

I have a C++ project (KiCad) which I'm trying to setup with Code.

My workspace directory is /home/user/build/kicad/, where build is a symlink to /storage/data/build.
I'm generating a compile_commands.json file using cmake in ./build.

The issue is that Code incorrectly thinks any source file cannot be found in compile_commands.json.

This is a snippet from the file:

[ // ...
{
  "directory": "/home/user/build/kicad/build",
  "command": "/usr/bin/c++ <SNIP>",
  "file": "/home/user/build/kicad/build/api/cpp/api/common/envelope.pb.cc",
  "output": "api/CMakeFiles/kiapi.dir/cpp/api/common/envelope.pb.cc.o"
},
//...
]

When hand-editing the file to replace the absolute paths with symlink-resolved absolute paths things start working:

[ // ...
{
  "directory": "/storage/data/build/kicad/build",
  "command": "/usr/bin/c++ <SNIP>",
  "file": "/storage/data/build/kicad/build/api/cpp/api/common/envelope.pb.cc",
  "output": "api/CMakeFiles/kiapi.dir/cpp/api/common/envelope.pb.cc.o"
},
//...
]

From what I understand, cmake is actually correct here, as -afaik- paths need to be relative to the source dir or absolute, but don't have to resolve symlinks.

Would it be possible to fix this?
Probably the most elegant / secure way would be to resolve the paths read from compile_commands.json, but it may not be the most performant option.

Configuration and Logs

{
    "configurations": [
      {
        "name": "Linux",
        "intelliSenseMode": "linux-gcc-x64",
        "compileCommands": "${workspaceFolder}/build/compile_commands.json",
        "includePath": [
          "${workspaceFolder}",
          "${workspaceFolder}/include"
        ],
        "compilerPath": "/usr/bin/g++",
        "cStandard": "c17",
        "cppStandard": "c++20",
        "defines": [
        ],
        "browse": {
          "path": [
            "${workspaceFolder}"
          ],
          "limitSymbolsToIncludedHeaders": true
        }
      }
    ],
    "version": 4
}

Other Extensions

No response

Additional context

No response

[Colengms]

Hi @StefanHamminga . Thanks for reporting this. We can repro the issue and will look into it.