On Wed, Apr 19, 2017 at 12:29 PM, Jeff Law <l...@redhat.com> wrote: > On 04/19/2017 10:13 AM, Jakub Jelinek wrote: >> >> On Wed, Apr 19, 2017 at 09:55:19AM -0600, Jeff Law wrote: >>> >>> 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 <ja...@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 used TYPE_QUALS_NO_ADDR_SPACE because that seems to be used in >> modified_type_die elsewhere (dwarf2out.c has only one use of TYPE_QUALS >> and >> even that one ignores addr space bits, as it is masked with qual_mask; >> the rest just TYPE_QUALS_NO_ADDR_SPACE). I think with FUNCTION/METHOD >> types >> with addr space quals we end up in grossly untested territory that most >> likely will just not work at all. I think we don't do anything with the >> address space quals right now, in the future DWARF has segment identifiers >> and something like that could be emitted, but there needs to be ABI >> agreement on what it means. > > OK. So let's go with your patch -- my reading of modified_type_die was that > it would ignore address-space qualifiers. So I think your patch is safe, it > was the inconsistency in the message and the patch itself I was most > concerned about.
BTW, I think it would be a bit more correct to compare the quals with those of "main" rather than compare them to 0, though I suspect there aren't currently any types for which that produces a different result. Jason
