Re: Speaking of DWARF-2 macro info

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

Daniel Berlin wrote:-

> Watch what happens when i have it printf "Starting source file" at the
> beginning of dwarf2out_start_source_file, and "Ending source file" at
> the beginning of dwarf2out_end_source_file:
> 
> Example file tst.c:
> #define bob(A,b) A-b
> 
> Output:
> [root@localhost root]# /gccbuild/egcs/buil/gcc/cc1 -gdwarf-2 -g3 tst.c
> Starting source file!
> Starting source file!
> 
> Execution times (seconds)
>  parser                :   0.00 ( 0%) usr   0.00 ( 0%) sys   0.01 (11%)
> wall
>  TOTAL                 :   0.03             0.00             0.09

OK, let's get this fixed.

I'm confused.  In your initial post, you claimed that there was one
entry call too many.  Now you're claiming there are two.  Which is it?

If I put an fprintf in dwarf2out_{start,end}_source_file like you did,
then I get, on a file foo.c that #inclues a single header foo.h:

Initial			// c_common_parse_file's call of the debug hook
--Entered /tmp/foo.c	
Entered with callback   // cb_file_change for foo.h
--Entered /tmp/foo.h
Left			// cb_file_change for leaving foo.h
--Left

Here those beginning with "--" are in dwarf2out.c's callbacks.  The
other fprintf's are in c-lex.c.  So I can't reproduce your two excess
"Starting source file"'s.

Now, if I understand you, you want an extra

Left			// cb_file_change for leaving foo.c
--Left

This doesn't happen because, by (mis?)design, cpplib does not perform a
final hook for leaving the main file.  IIRC this was to avoid a #line
marker at the end of the input file, but I'm not 100% certain.  You can
see this in cppfiles.c:

  /* Don't generate a callback for popping the main file.  */
  if (pfile->buffer)
    {
      _cpp_do_file_change (pfile, LC_LEAVE, 0, 0, 0);

      /* Finally, push the next -included file, if any.  */
      if (!pfile->buffer->prev)
	pushed = _cpp_push_next_buffer (pfile);
    }

Do you want this callback to happen?  That's easy to change.  I could
avoid the linemarker some other way I imagine.

But then, I still don't understand.  In another mail you quoted the
debug_finish hook that output debug info for terminating the main file.
So wouldn't you then output that debug info twice?

Confused,

Neil.