Re: PATCH handle null cpplib buffer

[Neil Booth <neil at daikokuya dot co dot uk>]

Per Bothner wrote:-

> >No, [need_line is] fundamentally a property of the buffer.
> 
> Yes and no.  It's *usage* is "we do not have a clean line
> so we need to call _cpp_get_fresh_line."  This can have two
> causes:  we need to (try to) get another line from the buffer
> *or* we're at the end.  You may argue the latter is a special
> case of the former, but see below.

Hmm.  I think it becomes necessary to have it as part of
the buffer to do #include right, but I'm happy to be proven
wrong.
 
> >Can't we revert your 08-21 rather than introduce this?  I'm not
> >convinced from your 08-21 description that it was correct.  I'm
> >concerned that this code might become something that only works
> >some of the time, and untangling it will be very hard.
> 
> The problem is that old code never pops the "main" buffer.
> Obviously, the main buffer must be popped before a compile server
> starts reading a new main input file, and doing it as part of
> cpp_read_main_file is obviously ugly.
> 
> Perhaps there should be a new cpp_close_main_file routine?

Perhaps - that's fine with me.

> A related issue:  Processing of builtins including -D flags should
> probably be done *before* cpp_read_main_file.  At least this the way
> the compile server currently does it.  One reason is that logicallly
> the builtins and command line flags are not nested inside the main
> file - they are shared with other main files.  Though we might
> re-consider that - after all stdio.h is also shared with other
> main files, and when a fragment the include history isn't quite
> right - if it matters.  However, some _once initialization may
> depend on some command-line flags.

Right.  I tried to do this about 18-24 months ago, but could never
get round the preprocessing of preprocessed input and the debug
issue.

> It's Labor Day weekend here, and I don't expect to be online again
> until Tuesday.  Perhaps you could look at the compile server, and
> maybe come up with an alternative solution?

Sorry, I'm really short of time; I'm not even finding time to
work on the things I want to work on 8-)

Neil.