Determine launch.json configuration field from result of task

[michaeleisel]

I have a program that I run via a launch.json config, where the program's path gets determined by the preLaunchTask. The task writes a file out with the path, and the launch config reads from that path:

tasks.json

{
    "version": "2.0.0",
    "tasks": [
      {
        "label": "gen_file_path",
        "type": "shell",
        "command": "/path/to/gen_file_path",
        "problemMatcher": []
      }
    ],
}

launch.json

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Run C++",
            "type": "cppdbg",
            "request": "launch",
            "cwd": "${workspaceRoot}",
            "program": "${input:fileContent}",
            "preLaunchTask": "gen_file_path"
        },
    ],
    "inputs": [
        {
            "id": "fileContent",
            "type": "command",
            "command": "extension.commandvariable.file.content",
            "args": {
                "fileName": "/path/to/output_from_task"
            }
        }
    ]
}

However, this fails because VSCode reads from the file before the preLaunchTask runs, so it can't get the new output. Is there any way to populate a field in a launch.json configuration from the output of a task?

[vs-code-engineering]

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