what about a compiler probe?

[Paul Brook]

>   when given the -fcompiler-probe flag, it should get an a string
>   option with it. If this string is a (Unix) file path it indicate a
>   Unix socket or FIFO; if it starts with a vertical pipe bar | it
>   starts the command and communicate with it thru pipes. Typically the
>   command is some client application (either a GTK graphical
>   interface, or an Emacs, or perhaps a FastCGI) which communicates
>   with GCC thru a textual protocol to be defined and documented.
>
> The textual protcol should permit to examine, but not change, the
> compilation state. For a lenghtly static analysis, it could be used to
> show the properties the compiler currently know about a given
> (compiled) source point.

Sounds like something a decent debugger and a small about of scripting should 
already be able to do.

Paul