Help implements the help subcommand for a multichecker or unitchecker style command.

Parse creates a flag for each of the analyzer's flags, including (in multi mode) a flag named after the analyzer, parses the flags, then filters and returns the list of analyzers enabled by flags.

PrintPlain prints a diagnostic in plain text form, with context specified by the -c flag.

-c=N: if N>0, display offending line plus N lines of context.

-json.

A JSONTree is a mapping from package ID to analysis name to result.