Re: Elfutils module reporting

[Roland McGrath <roland at redhat dot com>]

The expected pattern is that you do:

	dwfl_report_begin
	dwfl_report_foo all modules that are in the address space now
	dwfl_report_end

i.e., just like with a fresh Dwfl, but dwfl_report_begin instead of dwfl_begin.
This preserves the existing data structures for modules that haven't
changed since before dwfl_report_begin, and removes any old modules that
you didn't report again.  

dwfl_report_begin_add is intended for something like gdb's add-symbol-file,
where you are always just adding one new thing as opposed to re-synch'ing
to the new set of mappings after they've changed.  It's just a shorthand
and mild optimization for re-reporting all the existing modules after
dwfl_report_begin.

I could add something like a dwfl_report_remove to de-report a reported
module in a reporting loop (which after dwfl_report_begin_add would be
equivalent to removing the preexisting module).  But I'd rather exercise
the interface as it stands a bit more before deciding to add a
microoptimization.

> I got an assertion failure at the dwfl_report_end stage
>  /home/yyz/npremji/mainworkspace/frysk/frysk-imports/elfutils/libdwfl/dwfl_module.c:249: 
> dwfl_report_end: Assertion `i == dwfl->nmodules' failed.

Please send me a small C test program to reproduce this bug.


Thanks,
Roland