Re: Emacs contributions, C and Lisp

[David Engster]

Richard Stallman writes:
>   > David wants to write a GCC plugin that outputs the complete AST.
>
> We do not want to promote that sort of plugin.

After reading a bit about how GCC plugins came into being, I stumbled
upon

  https://www.gnu.org/licenses/gcc-exception-3.1-faq.html

which has this:

    When we first considered adding a plugin infrastructure to GCC, we
    were deeply concerned about the possibility that someone would write
    a plugin that would merely save GCC's internal, low-level
    compilation data structures to disk. With that done, other software
    would be able to optimize or otherwise improve that code without
    being directly connected to GCC. It may have been difficult for us
    to argue that those programs should be subject to the GPL's
    copyleft, so we wanted to discourage these sorts of arrangements.

    We do that by excluding such output from the definition of Target
    Code. Because of this, even if someone writes a plugin that saves
    this information to disk, any programs that change the structures
    before GCC writes out Target Code will be involved in the
    Compilation Process. If that program is proprietary, the exception
    will not be available to any software compiled with it; the object
    code that GCC ultimately creates will have to be distributed under
    the terms of the GPL.

Now I'm even more confused why you'd have a problem with exporting the
AST.

-David