Function parse_preprocessed 

pub fn parse_preprocessed(preprocessed: &Preprocessed) -> Parse

Parse a preprocessed stream.

The tree covers the expanded text, not the file as written: an #include brought other files into it and a conditional cut parts of it out. parse is the byte-exact path; this is the one that sees what a compiler would.

The preprocessor’s own diagnostics come first, because a file that failed to include something explains most of what follows.