Re: [PATCH] Fix ICE in modified_type_die (PR debug/80461)

[Jeff Law <law at redhat dot com>]

On 04/19/2017 09:10 AM, Jakub Jelinek wrote:
> On Wed, Apr 19, 2017 at 08:57:52AM -0600, Jeff Law wrote:
> > > 2017-04-19  Jakub Jelinek  <jakub@redhat.com>
> > >
> > > 	PR debug/80461
> > > 	* dwarf2out.c (modified_type_die, gen_type_die_with_usage):
> > > 	Check for t with zero TYPE_QUALS_NO_ADDR_SPACE.
> > >
> > > 	* g++.dg/debug/pr80461.C: New test.
> > I'm going to assume your use of TYPE_QUALS_NO_ADDR_SPACE vs TYPE_QUALS or
> > TYPE_QUALS_NO_ADDR_SPACE_NO_ATOMIC is correct.
>
> I don't really know.  For address space quals I think one would need to have
> pointer-to-members in different code address spaces, not sure if we support
> anything like that.  And atomic is C only which doesn't have
> pointer-to-members.
To put it another way, in your message you indicated that 
modified_type_die expects either an unqualified type or the type itself 
and that your patch makes sure we only pick unqualified types.

Using TYPE_QUALS_NO_ADDR_SPACE like you have seems to conflict with 
those statements.  So I'm curious why you allow address space qualifiers 
to pass through, but no others.   It just seems odd.

I'm guessing you're doing that because modified_type_die ignores address 
space qualifiers (and it only conditionally ignores atomics or restrict 
based on dwarf level).  But it'd be good to get a confirmation that's 
what you were thinking.

jeff