Capture the output stream of the Clang plugins

[hribz]

I have a clang plugin, and I want to use it by panda CompilerAction plugin. The clang plugin output to the stdout/err stream, not generate files to output directory.
I'd like to save the clang plugin's output by panda, but panda CompilerAction plugin doesn't have field "stream". Please add functionality to PANDA to capture the output stream of the Clang plugin.

{
    "comment": "Example plugin for Panda driver.",
    "type": "CompilerAction",
    "action": {
        "title": "Print all function name",
        "args": ["-fsyntax-only", "-fplugin=xxx"],
        "extname": ".f",
        "stream": "stdout"
    }
}