2 Copyright 2009, 2010 Free Software Foundation, Inc.
3 Contributed by CodeSourcery, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
24 #include "diagnostic-core.h"
29 #include "plugin-api.h"
30 #include "lto-streamer.h"
32 /* Vector to keep track of external variables we've seen so far. */
33 VEC(tree
,gc
) *lto_global_var_decls
;
35 /* Symbol table entry. */
37 struct GTY(()) lto_symtab_entry_def
39 /* The symbol table entry key, an IDENTIFIER. */
41 /* The symbol table entry, a DECL. */
43 /* The cgraph node if decl is a function decl. Filled in during the
45 struct cgraph_node
*node
;
46 /* The varpool node if decl is a variable decl. Filled in during the
48 struct varpool_node
*vnode
;
49 /* LTO file-data and symbol resolution for this decl. */
50 struct lto_file_decl_data
* GTY((skip (""))) file_data
;
51 enum ld_plugin_symbol_resolution resolution
;
52 /* True when resolution was guessed and not read from the file. */
54 /* Pointer to the next entry with the same key. Before decl merging
55 this links all symbols from the different TUs. After decl merging
56 this links merged but incompatible decls, thus all prevailing ones
58 struct lto_symtab_entry_def
*next
;
60 typedef struct lto_symtab_entry_def
*lto_symtab_entry_t
;
62 /* A poor man's symbol table. This hashes identifier to prevailing DECL
65 static GTY ((if_marked ("lto_symtab_entry_marked_p"),
66 param_is (struct lto_symtab_entry_def
)))
67 htab_t lto_symtab_identifiers
;
69 /* Free symtab hashtable. */
72 lto_symtab_free (void)
74 htab_delete (lto_symtab_identifiers
);
75 lto_symtab_identifiers
= NULL
;
78 /* Return the hash value of an lto_symtab_entry_t object pointed to by P. */
81 lto_symtab_entry_hash (const void *p
)
83 const struct lto_symtab_entry_def
*base
=
84 (const struct lto_symtab_entry_def
*) p
;
85 return IDENTIFIER_HASH_VALUE (base
->id
);
88 /* Return non-zero if P1 and P2 points to lto_symtab_entry_def structs
89 corresponding to the same symbol. */
92 lto_symtab_entry_eq (const void *p1
, const void *p2
)
94 const struct lto_symtab_entry_def
*base1
=
95 (const struct lto_symtab_entry_def
*) p1
;
96 const struct lto_symtab_entry_def
*base2
=
97 (const struct lto_symtab_entry_def
*) p2
;
98 return (base1
->id
== base2
->id
);
101 /* Returns non-zero if P points to an lto_symtab_entry_def struct that needs
102 to be marked for GC. */
105 lto_symtab_entry_marked_p (const void *p
)
107 const struct lto_symtab_entry_def
*base
=
108 (const struct lto_symtab_entry_def
*) p
;
110 /* Keep this only if the common IDENTIFIER_NODE of the symtab chain
111 is marked which it will be if at least one of the DECLs in the
113 return ggc_marked_p (base
->id
);
116 /* Lazily initialize resolution hash tables. */
119 lto_symtab_maybe_init_hash_table (void)
121 if (lto_symtab_identifiers
)
124 lto_symtab_identifiers
=
125 htab_create_ggc (1021, lto_symtab_entry_hash
,
126 lto_symtab_entry_eq
, NULL
);
129 /* Registers DECL with the LTO symbol table as having resolution RESOLUTION
130 and read from FILE_DATA. */
133 lto_symtab_register_decl (tree decl
,
134 ld_plugin_symbol_resolution_t resolution
,
135 struct lto_file_decl_data
*file_data
)
137 lto_symtab_entry_t new_entry
;
140 /* Check that declarations reaching this function do not have
141 properties inconsistent with having external linkage. If any of
142 these asertions fail, then the object file reader has failed to
143 detect these cases and issue appropriate error messages. */
145 && TREE_PUBLIC (decl
)
146 && (TREE_CODE (decl
) == VAR_DECL
147 || TREE_CODE (decl
) == FUNCTION_DECL
)
148 && DECL_ASSEMBLER_NAME_SET_P (decl
));
149 if (TREE_CODE (decl
) == VAR_DECL
150 && DECL_INITIAL (decl
))
151 gcc_assert (!DECL_EXTERNAL (decl
)
152 || (TREE_STATIC (decl
) && TREE_READONLY (decl
)));
153 if (TREE_CODE (decl
) == FUNCTION_DECL
)
154 gcc_assert (!DECL_ABSTRACT (decl
));
156 new_entry
= ggc_alloc_cleared_lto_symtab_entry_def ();
157 new_entry
->id
= (*targetm
.asm_out
.mangle_assembler_name
)
158 (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
)));
159 new_entry
->decl
= decl
;
160 new_entry
->resolution
= resolution
;
161 new_entry
->file_data
= file_data
;
163 lto_symtab_maybe_init_hash_table ();
164 slot
= htab_find_slot (lto_symtab_identifiers
, new_entry
, INSERT
);
165 new_entry
->next
= (lto_symtab_entry_t
) *slot
;
169 /* Get the lto_symtab_entry_def struct associated with ID
172 static lto_symtab_entry_t
173 lto_symtab_get (tree id
)
175 struct lto_symtab_entry_def temp
;
178 lto_symtab_maybe_init_hash_table ();
180 slot
= htab_find_slot (lto_symtab_identifiers
, &temp
, NO_INSERT
);
181 return slot
? (lto_symtab_entry_t
) *slot
: NULL
;
184 /* Get the linker resolution for DECL. */
186 enum ld_plugin_symbol_resolution
187 lto_symtab_get_resolution (tree decl
)
189 lto_symtab_entry_t e
;
191 gcc_assert (DECL_ASSEMBLER_NAME_SET_P (decl
));
193 e
= lto_symtab_get ((*targetm
.asm_out
.mangle_assembler_name
)
194 (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
))));
195 while (e
&& e
->decl
!= decl
)
200 return e
->resolution
;
204 /* Replace the cgraph node NODE with PREVAILING_NODE in the cgraph, merging
205 all edges and removing the old node. */
208 lto_cgraph_replace_node (struct cgraph_node
*node
,
209 struct cgraph_node
*prevailing_node
)
211 struct cgraph_edge
*e
, *next
;
214 if (cgraph_dump_file
)
216 fprintf (cgraph_dump_file
, "Replacing cgraph node %s/%i by %s/%i"
218 cgraph_node_name (node
), node
->uid
,
219 cgraph_node_name (prevailing_node
),
220 prevailing_node
->uid
,
221 IDENTIFIER_POINTER ((*targetm
.asm_out
.mangle_assembler_name
)
222 (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (node
->symbol
.decl
)))));
225 /* Merge node flags. */
226 if (node
->symbol
.force_output
)
227 cgraph_mark_force_output_node (prevailing_node
);
229 cgraph_mark_reachable_node (prevailing_node
);
230 if (node
->symbol
.address_taken
)
232 gcc_assert (!prevailing_node
->global
.inlined_to
);
233 cgraph_mark_address_taken_node (prevailing_node
);
236 /* Redirect all incoming edges. */
238 = types_compatible_p (TREE_TYPE (TREE_TYPE (prevailing_node
->symbol
.decl
)),
239 TREE_TYPE (TREE_TYPE (node
->symbol
.decl
)));
240 for (e
= node
->callers
; e
; e
= next
)
242 next
= e
->next_caller
;
243 cgraph_redirect_edge_callee (e
, prevailing_node
);
244 /* If there is a mismatch between the supposed callee return type and
245 the real one do not attempt to inline this function.
246 ??? We really need a way to match function signatures for ABI
247 compatibility and perform related promotions at inlining time. */
249 e
->call_stmt_cannot_inline_p
= 1;
251 /* Redirect incomming references. */
252 ipa_clone_referring ((symtab_node
)prevailing_node
, &node
->symbol
.ref_list
);
254 /* Finally remove the replaced node. */
255 cgraph_remove_node (node
);
258 /* Replace the cgraph node NODE with PREVAILING_NODE in the cgraph, merging
259 all edges and removing the old node. */
262 lto_varpool_replace_node (struct varpool_node
*vnode
,
263 struct varpool_node
*prevailing_node
)
265 gcc_assert (!vnode
->finalized
|| prevailing_node
->finalized
);
266 gcc_assert (!vnode
->analyzed
|| prevailing_node
->analyzed
);
268 ipa_clone_referring ((symtab_node
)prevailing_node
, &vnode
->symbol
.ref_list
);
270 /* Be sure we can garbage collect the initializer. */
271 if (DECL_INITIAL (vnode
->symbol
.decl
))
272 DECL_INITIAL (vnode
->symbol
.decl
) = error_mark_node
;
273 /* Finally remove the replaced node. */
274 varpool_remove_node (vnode
);
277 /* Merge two variable or function symbol table entries PREVAILING and ENTRY.
278 Return false if the symbols are not fully compatible and a diagnostic
279 should be emitted. */
282 lto_symtab_merge (lto_symtab_entry_t prevailing
, lto_symtab_entry_t entry
)
284 tree prevailing_decl
= prevailing
->decl
;
285 tree decl
= entry
->decl
;
286 tree prevailing_type
, type
;
288 /* Merge decl state in both directions, we may still end up using
290 TREE_ADDRESSABLE (prevailing_decl
) |= TREE_ADDRESSABLE (decl
);
291 TREE_ADDRESSABLE (decl
) |= TREE_ADDRESSABLE (prevailing_decl
);
293 /* The linker may ask us to combine two incompatible symbols.
294 Detect this case and notify the caller of required diagnostics. */
296 if (TREE_CODE (decl
) == FUNCTION_DECL
)
298 if (!types_compatible_p (TREE_TYPE (prevailing_decl
),
300 /* If we don't have a merged type yet...sigh. The linker
301 wouldn't complain if the types were mismatched, so we
302 probably shouldn't either. Just use the type from
303 whichever decl appears to be associated with the
304 definition. If for some odd reason neither decl is, the
311 /* Now we exclusively deal with VAR_DECLs. */
313 /* Sharing a global symbol is a strong hint that two types are
314 compatible. We could use this information to complete
315 incomplete pointed-to types more aggressively here, ignoring
316 mismatches in both field and tag names. It's difficult though
317 to guarantee that this does not have side-effects on merging
318 more compatible types from other translation units though. */
320 /* We can tolerate differences in type qualification, the
321 qualification of the prevailing definition will prevail.
322 ??? In principle we might want to only warn for structurally
323 incompatible types here, but unless we have protective measures
324 for TBAA in place that would hide useful information. */
325 prevailing_type
= TYPE_MAIN_VARIANT (TREE_TYPE (prevailing_decl
));
326 type
= TYPE_MAIN_VARIANT (TREE_TYPE (decl
));
328 if (!types_compatible_p (prevailing_type
, type
))
330 if (COMPLETE_TYPE_P (type
))
333 /* If type is incomplete then avoid warnings in the cases
334 that TBAA handles just fine. */
336 if (TREE_CODE (prevailing_type
) != TREE_CODE (type
))
339 if (TREE_CODE (prevailing_type
) == ARRAY_TYPE
)
341 tree tem1
= TREE_TYPE (prevailing_type
);
342 tree tem2
= TREE_TYPE (type
);
343 while (TREE_CODE (tem1
) == ARRAY_TYPE
344 && TREE_CODE (tem2
) == ARRAY_TYPE
)
346 tem1
= TREE_TYPE (tem1
);
347 tem2
= TREE_TYPE (tem2
);
350 if (TREE_CODE (tem1
) != TREE_CODE (tem2
))
353 if (!types_compatible_p (tem1
, tem2
))
357 /* Fallthru. Compatible enough. */
360 /* ??? We might want to emit a warning here if type qualification
361 differences were spotted. Do not do this unconditionally though. */
363 /* There is no point in comparing too many details of the decls here.
364 The type compatibility checks or the completing of types has properly
365 dealt with most issues. */
367 /* The following should all not invoke fatal errors as in non-LTO
368 mode the linker wouldn't complain either. Just emit warnings. */
370 /* Report a warning if user-specified alignments do not match. */
371 if ((DECL_USER_ALIGN (prevailing_decl
) && DECL_USER_ALIGN (decl
))
372 && DECL_ALIGN (prevailing_decl
) < DECL_ALIGN (decl
))
378 /* Return true if the symtab entry E can be replaced by another symtab
382 lto_symtab_resolve_replaceable_p (lto_symtab_entry_t e
)
384 if (DECL_EXTERNAL (e
->decl
)
385 || DECL_COMDAT (e
->decl
)
386 || DECL_ONE_ONLY (e
->decl
)
387 || DECL_WEAK (e
->decl
))
390 if (TREE_CODE (e
->decl
) == VAR_DECL
)
391 return (DECL_COMMON (e
->decl
)
392 || (!flag_no_common
&& !DECL_INITIAL (e
->decl
)));
397 /* Return true if the symtab entry E can be the prevailing one. */
400 lto_symtab_resolve_can_prevail_p (lto_symtab_entry_t e
)
402 /* The C++ frontend ends up neither setting TREE_STATIC nor
403 DECL_EXTERNAL on virtual methods but only TREE_PUBLIC.
404 So do not reject !TREE_STATIC here but only DECL_EXTERNAL. */
405 if (DECL_EXTERNAL (e
->decl
))
408 /* For functions we need a non-discarded body. */
409 if (TREE_CODE (e
->decl
) == FUNCTION_DECL
)
410 return (e
->node
&& e
->node
->analyzed
);
412 else if (TREE_CODE (e
->decl
) == VAR_DECL
)
416 return e
->vnode
->finalized
;
422 /* Resolve the symbol with the candidates in the chain *SLOT and store
423 their resolutions. */
426 lto_symtab_resolve_symbols (void **slot
)
428 lto_symtab_entry_t e
;
429 lto_symtab_entry_t prevailing
= NULL
;
431 /* Always set e->node so that edges are updated to reflect decl merging. */
432 for (e
= (lto_symtab_entry_t
) *slot
; e
; e
= e
->next
)
434 if (TREE_CODE (e
->decl
) == FUNCTION_DECL
)
435 e
->node
= cgraph_get_node (e
->decl
);
436 else if (TREE_CODE (e
->decl
) == VAR_DECL
)
437 e
->vnode
= varpool_get_node (e
->decl
);
438 if (e
->resolution
== LDPR_PREVAILING_DEF_IRONLY
439 || e
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
440 || e
->resolution
== LDPR_PREVAILING_DEF
)
444 /* If the chain is already resolved there is nothing else to do. */
448 /* Find the single non-replaceable prevailing symbol and
449 diagnose ODR violations. */
450 for (e
= (lto_symtab_entry_t
) *slot
; e
; e
= e
->next
)
452 if (!lto_symtab_resolve_can_prevail_p (e
))
454 e
->resolution
= LDPR_RESOLVED_IR
;
459 /* Set a default resolution - the final prevailing one will get
461 e
->resolution
= LDPR_PREEMPTED_IR
;
463 if (!lto_symtab_resolve_replaceable_p (e
))
467 error_at (DECL_SOURCE_LOCATION (e
->decl
),
468 "%qD has already been defined", e
->decl
);
469 inform (DECL_SOURCE_LOCATION (prevailing
->decl
),
470 "previously defined here");
478 /* Do a second round choosing one from the replaceable prevailing decls. */
479 for (e
= (lto_symtab_entry_t
) *slot
; e
; e
= e
->next
)
481 if (e
->resolution
!= LDPR_PREEMPTED_IR
)
484 /* Choose the first function that can prevail as prevailing. */
485 if (TREE_CODE (e
->decl
) == FUNCTION_DECL
)
491 /* From variables that can prevail choose the largest one. */
493 || tree_int_cst_lt (DECL_SIZE (prevailing
->decl
),
494 DECL_SIZE (e
->decl
)))
502 /* If current lto files represent the whole program,
503 it is correct to use LDPR_PREVALING_DEF_IRONLY.
504 If current lto files are part of whole program, internal
505 resolver doesn't know if it is LDPR_PREVAILING_DEF
506 or LDPR_PREVAILING_DEF_IRONLY. Use IRONLY conforms to
507 using -fwhole-program. Otherwise, it doesn't
508 matter using either LDPR_PREVAILING_DEF or
509 LDPR_PREVAILING_DEF_IRONLY
511 FIXME: above workaround due to gold plugin makes some
512 variables IRONLY, which are indeed PREVAILING_DEF in
513 resolution file. These variables still need manual
514 externally_visible attribute. */
515 prevailing
->resolution
= LDPR_PREVAILING_DEF_IRONLY
;
516 prevailing
->guessed
= true;
519 /* Merge all decls in the symbol table chain to the prevailing decl and
520 issue diagnostics about type mismatches. If DIAGNOSED_P is true
521 do not issue further diagnostics.*/
524 lto_symtab_merge_decls_2 (void **slot
, bool diagnosed_p
)
526 lto_symtab_entry_t prevailing
, e
;
527 VEC(tree
, heap
) *mismatches
= NULL
;
531 /* Nothing to do for a single entry. */
532 prevailing
= (lto_symtab_entry_t
) *slot
;
533 if (!prevailing
->next
)
536 /* Try to merge each entry with the prevailing one. */
537 for (e
= prevailing
->next
; e
; e
= e
->next
)
539 if (!lto_symtab_merge (prevailing
, e
)
541 VEC_safe_push (tree
, heap
, mismatches
, e
->decl
);
543 if (VEC_empty (tree
, mismatches
))
546 /* Diagnose all mismatched re-declarations. */
547 FOR_EACH_VEC_ELT (tree
, mismatches
, i
, decl
)
549 if (!types_compatible_p (TREE_TYPE (prevailing
->decl
), TREE_TYPE (decl
)))
550 diagnosed_p
|= warning_at (DECL_SOURCE_LOCATION (decl
), 0,
551 "type of %qD does not match original "
552 "declaration", decl
);
554 else if ((DECL_USER_ALIGN (prevailing
->decl
) && DECL_USER_ALIGN (decl
))
555 && DECL_ALIGN (prevailing
->decl
) < DECL_ALIGN (decl
))
557 diagnosed_p
|= warning_at (DECL_SOURCE_LOCATION (decl
), 0,
558 "alignment of %qD is bigger than "
559 "original declaration", decl
);
563 inform (DECL_SOURCE_LOCATION (prevailing
->decl
),
564 "previously declared here");
566 VEC_free (tree
, heap
, mismatches
);
569 /* Helper to process the decl chain for the symbol table entry *SLOT. */
572 lto_symtab_merge_decls_1 (void **slot
, void *data ATTRIBUTE_UNUSED
)
574 lto_symtab_entry_t e
, prevailing
;
575 bool diagnosed_p
= false;
577 /* Compute the symbol resolutions. This is a no-op when using the
579 lto_symtab_resolve_symbols (slot
);
581 /* Find the prevailing decl. */
582 for (prevailing
= (lto_symtab_entry_t
) *slot
;
584 && prevailing
->resolution
!= LDPR_PREVAILING_DEF_IRONLY
585 && prevailing
->resolution
!= LDPR_PREVAILING_DEF_IRONLY_EXP
586 && prevailing
->resolution
!= LDPR_PREVAILING_DEF
;
587 prevailing
= prevailing
->next
)
590 /* Assert it's the only one. */
592 for (e
= prevailing
->next
; e
; e
= e
->next
)
594 if (e
->resolution
== LDPR_PREVAILING_DEF_IRONLY
595 || e
->resolution
== LDPR_PREVAILING_DEF_IRONLY_EXP
596 || e
->resolution
== LDPR_PREVAILING_DEF
)
597 fatal_error ("multiple prevailing defs for %qE",
598 DECL_NAME (prevailing
->decl
));
601 /* If there's not a prevailing symbol yet it's an external reference.
602 Happens a lot during ltrans. Choose the first symbol with a
603 cgraph or a varpool node. */
606 prevailing
= (lto_symtab_entry_t
) *slot
;
607 /* For functions choose one with a cgraph node. */
608 if (TREE_CODE (prevailing
->decl
) == FUNCTION_DECL
)
609 while (!prevailing
->node
611 prevailing
= prevailing
->next
;
612 /* For variables chose with a priority variant with vnode
613 attached (i.e. from unit where external declaration of
614 variable is actually used).
615 When there are multiple variants, chose one with size.
616 This is needed for C++ typeinfos, for example in
617 lto/20081204-1 there are typeifos in both units, just
618 one of them do have size. */
619 if (TREE_CODE (prevailing
->decl
) == VAR_DECL
)
621 for (e
= prevailing
->next
; e
; e
= e
->next
)
622 if ((!prevailing
->vnode
&& e
->vnode
)
623 || ((prevailing
->vnode
!= NULL
) == (e
->vnode
!= NULL
)
624 && !COMPLETE_TYPE_P (TREE_TYPE (prevailing
->decl
))
625 && COMPLETE_TYPE_P (TREE_TYPE (e
->decl
))))
630 /* Move it first in the list. */
631 if ((lto_symtab_entry_t
) *slot
!= prevailing
)
633 for (e
= (lto_symtab_entry_t
) *slot
; e
->next
!= prevailing
; e
= e
->next
)
635 e
->next
= prevailing
->next
;
636 prevailing
->next
= (lto_symtab_entry_t
) *slot
;
637 *slot
= (void *) prevailing
;
640 /* Record the prevailing variable. */
641 if (TREE_CODE (prevailing
->decl
) == VAR_DECL
)
642 VEC_safe_push (tree
, gc
, lto_global_var_decls
, prevailing
->decl
);
644 /* Diagnose mismatched objects. */
645 for (e
= prevailing
->next
; e
; e
= e
->next
)
647 if (TREE_CODE (prevailing
->decl
) == TREE_CODE (e
->decl
))
650 switch (TREE_CODE (prevailing
->decl
))
653 gcc_assert (TREE_CODE (e
->decl
) == FUNCTION_DECL
);
654 error_at (DECL_SOURCE_LOCATION (e
->decl
),
655 "variable %qD redeclared as function", prevailing
->decl
);
659 gcc_assert (TREE_CODE (e
->decl
) == VAR_DECL
);
660 error_at (DECL_SOURCE_LOCATION (e
->decl
),
661 "function %qD redeclared as variable", prevailing
->decl
);
671 inform (DECL_SOURCE_LOCATION (prevailing
->decl
),
672 "previously declared here");
674 /* Merge the chain to the single prevailing decl and diagnose
676 lto_symtab_merge_decls_2 (slot
, diagnosed_p
);
678 /* Store resolution decision into the callgraph.
679 In LTRANS don't overwrite information we stored into callgraph at
682 Do not bother to store guessed decisions. Generic code knows how
683 to handle UNKNOWN relocation well.
685 The problem with storing guessed decision is whether to use
686 PREVAILING_DEF, PREVAILING_DEF_IRONLY, PREVAILING_DEF_IRONLY_EXP.
687 First one would disable some whole program optimizations, while
688 ther second would imply to many whole program assumptions. */
689 if (prevailing
->node
&& !flag_ltrans
&& !prevailing
->guessed
)
690 prevailing
->node
->symbol
.resolution
= prevailing
->resolution
;
691 else if (prevailing
->vnode
&& !flag_ltrans
&& !prevailing
->guessed
)
692 prevailing
->vnode
->symbol
.resolution
= prevailing
->resolution
;
696 /* Resolve and merge all symbol table chains to a prevailing decl. */
699 lto_symtab_merge_decls (void)
701 lto_symtab_maybe_init_hash_table ();
702 htab_traverse (lto_symtab_identifiers
, lto_symtab_merge_decls_1
, NULL
);
705 /* Helper to process the decl chain for the symbol table entry *SLOT. */
708 lto_symtab_merge_cgraph_nodes_1 (void **slot
, void *data ATTRIBUTE_UNUSED
)
710 lto_symtab_entry_t e
, prevailing
= (lto_symtab_entry_t
) *slot
;
712 if (!prevailing
->next
)
715 /* Replace the cgraph node of each entry with the prevailing one. */
716 for (e
= prevailing
->next
; e
; e
= e
->next
)
720 /* In case we prevail funcion by an alias, we can run into case
721 that the alias has no cgraph node attached, since it was
722 previously unused. Create the node. */
723 if (!prevailing
->node
)
725 prevailing
->node
= cgraph_create_node (prevailing
->decl
);
726 prevailing
->node
->alias
= true;
728 lto_cgraph_replace_node (e
->node
, prevailing
->node
);
730 if (e
->vnode
!= NULL
)
732 if (!prevailing
->vnode
)
734 prevailing
->vnode
= varpool_node (prevailing
->decl
);
735 prevailing
->vnode
->alias
= true;
737 lto_varpool_replace_node (e
->vnode
, prevailing
->vnode
);
741 /* Drop all but the prevailing decl from the symtab. */
742 prevailing
->next
= NULL
;
747 /* Merge cgraph nodes according to the symbol merging done by
748 lto_symtab_merge_decls. */
751 lto_symtab_merge_cgraph_nodes (void)
753 struct cgraph_node
*node
;
754 struct varpool_node
*vnode
;
755 lto_symtab_maybe_init_hash_table ();
756 htab_traverse (lto_symtab_identifiers
, lto_symtab_merge_cgraph_nodes_1
, NULL
);
758 FOR_EACH_FUNCTION (node
)
759 if ((node
->thunk
.thunk_p
|| node
->alias
)
760 && node
->thunk
.alias
)
761 node
->thunk
.alias
= lto_symtab_prevailing_decl (node
->thunk
.alias
);
762 FOR_EACH_VARIABLE (vnode
)
764 vnode
->alias_of
= lto_symtab_prevailing_decl (vnode
->alias_of
);
767 /* Given the decl DECL, return the prevailing decl with the same name. */
770 lto_symtab_prevailing_decl (tree decl
)
772 lto_symtab_entry_t ret
;
774 /* Builtins and local symbols are their own prevailing decl. */
775 if (!TREE_PUBLIC (decl
) || is_builtin_fn (decl
))
778 /* DECL_ABSTRACTs are their own prevailng decl. */
779 if (TREE_CODE (decl
) == FUNCTION_DECL
&& DECL_ABSTRACT (decl
))
782 /* Ensure DECL_ASSEMBLER_NAME will not set assembler name. */
783 gcc_assert (DECL_ASSEMBLER_NAME_SET_P (decl
));
785 /* Walk through the list of candidates and return the one we merged to. */
786 ret
= lto_symtab_get ((*targetm
.asm_out
.mangle_assembler_name
)
787 (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl
))));
794 #include "gt-lto-symtab.h"