libg++-2.8.1.3 and gcc-20000220 CVS

[Gabriel Dos Reis]

Zack Weinberg <zack@wolery.cumb.org> writes:

| On Tue, Feb 22, 2000 at 12:50:18AM +0100, Gabriel Dos Reis wrote:
| > 
| > Actually it would be handful if there were a hook for each _DECL
| > pointing to a list of #included filenames.  Then we might define a
| > concept of "abstract header":
| > 
| >    a header is abstract if it is a system header (or deemed so via a
| >    #pragma) or #included by an abstract header.
| > 
| > In normal state we'd output the "primary" abstract header for
| > diagnotic purpose and make the debugger know about the full pathname
| > for its needs.  IMHO, that will solve the two problems: how 
| > to make diagnostics readable and keep the debugger happy.
| > 
| > As to how to revert to the old behaviour, a flag will tell us whether
| > we should systematically output absolute pathnames (which is just a
| > list-dump op)
| > 
| > cpp would be responsible for providing the header-list.
| > 
| > Does it sound feasable to you? 
| 
| Yes, completely feasible.
| 
| The existing information cpplib has about headers is:
| - the full name
| - the short name
| - the directory it was found in
| - whether or not it's a "system" header
| 
| and you can walk back up the input stack to see where it was included
| from.

Cool!

| The concept of system headers is not quite the same as your concept of
| abstract headers, but from your definition it sounds like the one can
| be derived from the other. 

OK.

| ... What did you have in mind for the #pragma?

I think this feature would be helpful not only for system headers; a
third party library (e.g. v3 :-) may say `#pragma abstract_header' in
its primary  header in order to hide its internals.

	#ifndef _CPP_COMPLEX
	#pragma abstract_header
	#include <bits/std_complex.h>
	#endif

-- Gaby