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Date: Thu, 12 Jun 2003 18:07:00 -0000
From: Daniel Jacobowitz <drow@mvista.com>
To: David Carlton <carlton@kealia.com>
Cc: gdb <gdb@sources.redhat.com>, Elena Zannoni <ezannoni@redhat.com>,
	Jim Blandy <jimb@redhat.com>
Subject: Re: DW_AT_containing_type
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	gdb <gdb@sources.redhat.com>, Elena Zannoni <ezannoni@redhat.com>,
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On Thu, Jun 12, 2003 at 10:56:50AM -0700, David Carlton wrote:
> What's with GDB's and GCC's use of DW_AT_containing type?  As far as I
> can tell, it's only supposed to be used within
> DW_TAG_ptr_to_member_type, but GCC generates it and GDB uses it in
> many other contexts.
> 
> I'll try to find time to figure out how we use it later, but I wanted
> to raise the issue in case anybody knows the answer or in case other
> people aren't aware that we seem to be misusing it.

We are misusing it.  See the GCC source for a comment explaining this
GNU extension.  We use it to indicate which base type contains the
vtable pointer for the derived class; there are a number of other ways
to do it, and at one point we should switch to another way.

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer