On Thu, 21 Jun 2018, Jan Hubicka wrote:
> > Hi,
> > this patch drops DECL_ORIGINAL_TYPE streaming and also logic handling
> > external decls in blocks since we no longer stream them at all.
> >
> > Bootstrapped/regtested x86_64-linux, OK?
> Actually the patch dies with lto-bootstrap :(
> 0x9c44fc gen_member_die
> ../../gcc/dwarf2out.c:24947
> 0x9c4bb1 gen_struct_or_union_type_die
> ../../gcc/dwarf2out.c:25143
> 0x9c52dd gen_tagged_type_die
> ../../gcc/dwarf2out.c:25353
> 0x9c4ffe gen_typedef_die
> ../../gcc/dwarf2out.c:25259
> 0x9c6e5f gen_decl_die
> ../../gcc/dwarf2out.c:26248
> 0x9c5557 gen_type_die_with_usage
> ../../gcc/dwarf2out.c:25424
> 0x9c5bc2 gen_type_die
> ../../gcc/dwarf2out.c:25608
> 0x9a7756 modified_type_die
> ../../gcc/dwarf2out.c:13396
> 0x9bd011 add_type_attribute
> ../../gcc/dwarf2out.c:21523
> 0x9bf854 gen_subprogram_die
> ../../gcc/dwarf2out.c:22835
> 0x9c6d8c gen_decl_die
> ../../gcc/dwarf2out.c:26222
> 0x9c7db9 dwarf2out_decl
> ../../gcc/dwarf2out.c:26787
> 0x9c7e15 dwarf2out_function_decl
> ../../gcc/dwarf2out.c:26802
> 0xa65bd9 rest_of_handle_final
> ../../gcc/final.c:4704
> 0xa65d46 execute
> ../../gcc/final.c:4746
>
> I am going to respawn it becuase it seems odd that stage2 built but stage3
> failed. Clearly typeefs are determined by existence of original type:
>
> /* Returns true if X is a typedef decl. */
>
> bool
> is_typedef_decl (const_tree x)
> {
> return (x && TREE_CODE (x) == TYPE_DECL
> && DECL_ORIGINAL_TYPE (x) != NULL_TREE);
> }
>
> /* Returns true iff TYPE is a type variant created for a typedef. */
>
> bool
> typedef_variant_p (const_tree type)
> {
> return is_typedef_decl (TYPE_NAME (type));
> }
>
> however aren't we supposed to not touch these at late builds? We drop most of
> TYPE_DECLs in favour
> of IDENTIFIER_TYPE and thus also throwing away DECL_ORIGINAL_TYPEs.
We keep quite a bit of TYPE_DECLs around for devirt.
We shouldn't (very often...) end up trying to emit type DIEs late.
Here we're running into
/* If the prototype had an 'auto' or 'decltype(auto)' return
type,
emit the real type on the definition die. */
if (is_cxx () && debug_info_level > DINFO_LEVEL_TERSE)
{
dw_die_ref die = get_AT_ref (old_die, DW_AT_type);
but that's odd since get_AT_ref shoudn't be able to lookup DW_AT_type
in lto1.
So a testcase would be nice to have...
Richard.
> Honza
> >
> > Honza
> >
> > * lto-streamer-out.c (DFS::DFS_write_tree_body): Do not
> > stream DECL_ORIGINAL_TYPE.
> > (DFS::DFS_write_tree_body): Drop hack handling local external decls.
> > (hash_tree): Do not walk DECL_ORIGINAL_TYPE.
> > * tree-streamer-in.c (lto_input_ts_decl_non_common_tree_pointers):
> > Do not walk original type.
> > * tree-streamer-out.c (streamer_write_chain): Drop hack handling
> > external decls.
> > (write_ts_decl_non_common_tree_pointers): Do not stream
> > DECL_ORIGINAL_TYPE
> > * tree.c (free_lang_data_in_decl): Clear DECL_ORIGINAL_TYPE.
> > (find_decls_types_r): Do not walk DEC_ORIGINAL_TYPE.
> >
> > Index: lto-streamer-out.c
> > ===================================================================
> > --- lto-streamer-out.c (revision 261841)
> > +++ lto-streamer-out.c (working copy)
> > @@ -819,12 +819,6 @@ DFS::DFS_write_tree_body (struct output_
> > DFS_follow_tree_edge (DECL_DEBUG_EXPR (expr));
> > }
> >
> > - if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
> > - {
> > - if (TREE_CODE (expr) == TYPE_DECL)
> > - DFS_follow_tree_edge (DECL_ORIGINAL_TYPE (expr));
> > - }
> > -
> > if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
> > {
> > /* Make sure we don't inadvertently set the assembler name. */
> > @@ -907,14 +901,13 @@ DFS::DFS_write_tree_body (struct output_
> > if (CODE_CONTAINS_STRUCT (code, TS_BLOCK))
> > {
> > for (tree t = BLOCK_VARS (expr); t; t = TREE_CHAIN (t))
> > - if (VAR_OR_FUNCTION_DECL_P (t)
> > - && DECL_EXTERNAL (t))
> > - /* We have to stream externals in the block chain as
> > - non-references. See also
> > - tree-streamer-out.c:streamer_write_chain. */
> > - DFS_write_tree (ob, expr_state, t, ref_p, false);
> > - else
> > + {
> > + /* We would have to stream externals in the block chain as
> > + non-references but we should have dropped them in
> > + free-lang-data. */
> > + gcc_assert (!VAR_OR_FUNCTION_DECL_P (t) || !DECL_EXTERNAL (t));
> > DFS_follow_tree_edge (t);
> > + }
> >
> > DFS_follow_tree_edge (BLOCK_SUPERCONTEXT (expr));
> >
> > @@ -1261,12 +1249,6 @@ hash_tree (struct streamer_tree_cache_d
> > be able to call get_symbol_initial_value. */
> > }
> >
> > - if (CODE_CONTAINS_STRUCT (code, TS_DECL_NON_COMMON))
> > - {
> > - if (code == TYPE_DECL)
> > - visit (DECL_ORIGINAL_TYPE (t));
> > - }
> > -
> > if (CODE_CONTAINS_STRUCT (code, TS_DECL_WITH_VIS))
> > {
> > if (DECL_ASSEMBLER_NAME_SET_P (t))
> > Index: tree-streamer-in.c
> > ===================================================================
> > --- tree-streamer-in.c (revision 261841)
> > +++ tree-streamer-in.c (working copy)
> > @@ -728,11 +721,9 @@ lto_input_ts_decl_common_tree_pointers (
> > file being read. */
> >
> > static void
> > -lto_input_ts_decl_non_common_tree_pointers (struct lto_input_block *ib,
> > - struct data_in *data_in, tree expr)
> > +lto_input_ts_decl_non_common_tree_pointers (struct lto_input_block *,
> > + struct data_in *, tree)
> > {
> > - if (TREE_CODE (expr) == TYPE_DECL)
> > - DECL_ORIGINAL_TYPE (expr) = stream_read_tree (ib, data_in);
> > }
> >
> >
> > Index: tree-streamer-out.c
> > ===================================================================
> > --- tree-streamer-out.c (revision 261841)
> > +++ tree-streamer-out.c (working copy)
> > @@ -497,14 +494,10 @@ streamer_write_chain (struct output_bloc
> > {
> > /* We avoid outputting external vars or functions by reference
> > to the global decls section as we do not want to have them
> > - enter decl merging. This is, of course, only for the call
> > - for streaming BLOCK_VARS, but other callers are safe.
> > - See also lto-streamer-out.c:DFS_write_tree_body. */
> > - if (VAR_OR_FUNCTION_DECL_P (t)
> > - && DECL_EXTERNAL (t))
> > - stream_write_tree_shallow_non_ref (ob, t, ref_p);
> > - else
> > - stream_write_tree (ob, t, ref_p);
> > + enter decl merging. We should not need to do this anymore because
> > + free_lang_data removes them from block scopes. */
> > + gcc_assert (!VAR_OR_FUNCTION_DECL_P (t) || !DECL_EXTERNAL (t));
> > + stream_write_tree (ob, t, ref_p);
> >
> > t = TREE_CHAIN (t);
> > }
> > @@ -620,11 +613,8 @@ write_ts_decl_common_tree_pointers (stru
> > pointer fields. */
> >
> > static void
> > -write_ts_decl_non_common_tree_pointers (struct output_block *ob, tree expr,
> > - bool ref_p)
> > +write_ts_decl_non_common_tree_pointers (struct output_block *, tree, bool)
> > {
> > - if (TREE_CODE (expr) == TYPE_DECL)
> > - stream_write_tree (ob, DECL_ORIGINAL_TYPE (expr), ref_p);
> > }
> >
> >
> > Index: tree.c
> > ===================================================================
> > --- tree.c (revision 261841)
> > +++ tree.c (working copy)
> > @@ -5359,6 +5357,7 @@ free_lang_data_in_decl (tree decl)
> > DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
> > DECL_VISIBILITY_SPECIFIED (decl) = 0;
> > DECL_INITIAL (decl) = NULL_TREE;
> > + DECL_ORIGINAL_TYPE (decl) = NULL_TREE;
> > }
> > else if (TREE_CODE (decl) == FIELD_DECL)
> > DECL_INITIAL (decl) = NULL_TREE;
> > @@ -5471,10 +5470,6 @@ find_decls_types_r (tree *tp, int *ws, v
> > fld_worklist_push (DECL_ARGUMENTS (t), fld);
> > fld_worklist_push (DECL_RESULT (t), fld);
> > }
> > - else if (TREE_CODE (t) == TYPE_DECL)
> > - {
> > - fld_worklist_push (DECL_ORIGINAL_TYPE (t), fld);
> > - }
> > else if (TREE_CODE (t) == FIELD_DECL)
> > {
> > fld_worklist_push (DECL_FIELD_OFFSET (t), fld);
>
>
--
Richard Biener <[email protected]>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
