Re: <dwarf>: iteration over attributes swallows the last one

[Roland McGrath <roland at redhat dot com>]

As a general thing, please also push to some private branch when you post.
(One-offs are good for this, you can remove them later with push :user/foo.)
That way approvers can merge it directly rather than either telling you to
push it or using git-am.  (In this case, I think I want a different version
merged instead.  But this is a note for general procedure.)

> The scenario goes like this.
> * end iterator has an offset of 1
> * begin iterator has an offset of 0

Actually that's the pre-begin iterator.  

      inline const_iterator begin () const
      {
	const_iterator i = const_iterator (_m_die, 0);
	return ++i;
      }

The initialized-to-0 iterator is never seen anywhere else.  Hence:

>  	inline const_iterator (const debug_info_entry &die, ptrdiff_t offset)
> -	  : _m_die (die), _m_offset (offset) {}
> +	  : _m_die (die), _m_offset (offset)
> +	{
> +	  _m_attr.valp = NULL;
> +	}

No need for that, given:

	inline const_iterator &operator++ () // prefix
	{
	  _m_attr.valp = NULL;
	...

> As a fix for that, I propose to consider also NULL-ness of _m_attr.value 
> when doing the iterator comparison.  

I think you can just do valp == valp comparison and drop the offset
comparison.  The pointers will match when the offsets match, and two NULLs
are two end iterators.

Can you also please write a test case for this?  I'd guess a trivial program
using .to_string () does it since the busted iterator is used by that.

I've just pushed makefile cleanups that should make it simpler to copy the
src/Makefile.am magic into tests/Makefile.am to compile C++ cases there.


Thanks,
Roland