Setting sourceFileMap for multiple directories

I'm working in a project, where all source files are copied to one dir: /src before compilation. I would like to setup a sourceFileMap for C/C++ extension, which would map files in /src/ dir to multiple directories like this:

"sourceFileMap": {
    "D:\\proj\\src": "D:\\proj\\components\\ComponentA\\src",
    "D:\\proj\\src": "D:\\proj\\components\\ComponentB\\src",
    "D:\\proj\\src": "D:\\proj\\components\\ComponentC\\src",
},

Unfortunately, seems that launch.json does not accept multiple defined keys, and it's setting correct mapping only for last entry with same key.

Is it possible to create such configuration?