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Re: Silence merge warnings on artificial types
- From: Ilya Verbin <iverbin at gmail dot com>
- To: Jan Hubicka <hubicka at ucw dot cz>
- Cc: Jason Merrill <jason at redhat dot com>, Jakub Jelinek <jakub at redhat dot com>, gcc-patches at gcc dot gnu dot org, rguenther at suse dot de
- Date: Thu, 2 Apr 2015 21:23:03 +0300
- Subject: Re: Silence merge warnings on artificial types
- Authentication-results: sourceware.org; auth=none
- References: <20150330030257 dot GA71352 at kam dot mff dot cuni dot cz> <20150330153641 dot GA64930 at msticlxl57 dot ims dot intel dot com> <20150330170639 dot GD93920 at kam dot mff dot cuni dot cz> <20150330172102 dot GI1746 at tucnak dot redhat dot com> <20150330172321 dot GE14471 at atrey dot karlin dot mff dot cuni dot cz> <55198D94 dot 5020707 at redhat dot com> <20150331075121 dot GB62830 at kam dot mff dot cuni dot cz>
On Tue, Mar 31, 2015 at 09:51:21 +0200, Jan Hubicka wrote:
> this patch adds the ARTIFICIAL flag check to avoid ODR merging to these.
> I oriignally tested DECL_ARTIFICIAL (decl) (that is TYPE_NAME) that randomly
> dropped type names on some classes but not all.
>
> Jason, please do you know what is meaning of DECL_ARTIFICIAL on class type
> names? Perhaps we can drop them to 0 in free lang data?
>
> With this bug I triggered wrong devirtualization because we no longer insert
> non-odr types into a type inheritance graph. This is fixed by the lto_read_decls
> change and finally I triggered an ICE in ipa-devirt that due to the bug
> output a warning late and ICEd on streamer cache being NULL. I guess it is
> better to guard it even though all wanrings should be output early.
>
> Bootsrapped/regtested x86_64-linux, will commit it after chromium rebuild.
>
> Honza
>
> * tree.c (need_assembler_name_p): Artificial types have no ODR
> names.
> * ipa-devirt.c (warn_odr): Do not try to apply ODR cache when
> no caching is done.
>
> * lto.c (lto_read_decls): Move code registering odr types out
> of TYPE_CANONICAL conditional and also register polymorphic types.
> Index: tree.c
> ===================================================================
> --- tree.c (revision 221777)
> @@ -5139,6 +5145,7 @@ need_assembler_name_p (tree decl)
> && decl == TYPE_NAME (TREE_TYPE (decl))
> && !is_lang_specific (TREE_TYPE (decl))
> && AGGREGATE_TYPE_P (TREE_TYPE (decl))
> + && !TYPE_ARTIFICIAL (TREE_TYPE (decl))
> && !variably_modified_type_p (TREE_TYPE (decl), NULL_TREE)
> && !type_in_anonymous_namespace_p (TREE_TYPE (decl)))
> return !DECL_ASSEMBLER_NAME_SET_P (decl);
Hmm, libgomp.c++/target-3.C still fails.
Here is what I see in need_assembler_name_p:
<type_decl 0x2b5a8751aed8 .omp_data_s.3
type <record_type 0x2b5a87536690 .omp_data_s.3 BLK
size <integer_cst 0x2b5a873ce318 constant 192>
unit size <integer_cst 0x2b5a873ce2e8 constant 24>
align 64 symtab 0 alias set -1 canonical type 0x2b5a87536690
fields <field_decl 0x2b5a87537000 b.0 type <pointer_type 0x2b5a87536150>
unsigned DI file test.cpp line 8 col 13
size <integer_cst 0x2b5a873ace58 constant 64>
unit size <integer_cst 0x2b5a873ace70 constant 8>
align 64 offset_align 128
offset <integer_cst 0x2b5a873ace88 constant 0>
bit offset <integer_cst 0x2b5a873aced0 constant 0> context <record_type 0x2b5a87536690 .omp_data_s.3> chain <field_decl 0x2b5a87537098 s>> reference_to_this <reference_type 0x2b5a87536738>>
VOID file test.cpp line 11 col 13
align 1>
(TYPE_ARTIFICIAL = 0)
<type_decl 0x2b5a8751a850 .omp_data_s.3
type <record_type 0x2b5a8752cdc8 .omp_data_s.3 BLK
size <integer_cst 0x2b5a873ce318 constant 192>
unit size <integer_cst 0x2b5a873ce2e8 constant 24>
align 64 symtab 0 alias set -1 canonical type 0x2b5a8752cdc8
fields <field_decl 0x2b5a8751a980 b.0 type <pointer_type 0x2b5a8752c498>
unsigned DI file test.cpp line 8 col 13
size <integer_cst 0x2b5a873ace58 constant 64>
unit size <integer_cst 0x2b5a873ace70 constant 8>
align 64 offset_align 128
offset <integer_cst 0x2b5a873ace88 constant 0>
bit offset <integer_cst 0x2b5a873aced0 constant 0> context <record_type 0x2b5a8752cdc8 .omp_data_s.3> chain <field_decl 0x2b5a8751a8e8 s>>
pointer_to_this <pointer_type 0x2b5a87536888>>
VOID file test.cpp line 11 col 13
align 1>
(TYPE_ARTIFICIAL = 0)
-- Ilya