Support lower and upper limit for -fdbg-cnt flag.
[official-gcc.git] / gcc / symtab.c
blobc1533083573d9ac9afc6eb340dd8158abdec7706
1 /* Symbol table.
2 Copyright (C) 2012-2018 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
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
10 version.
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
15 for more details.
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/>. */
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "backend.h"
25 #include "target.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "gimple.h"
29 #include "timevar.h"
30 #include "cgraph.h"
31 #include "lto-streamer.h"
32 #include "print-tree.h"
33 #include "varasm.h"
34 #include "langhooks.h"
35 #include "output.h"
36 #include "ipa-utils.h"
37 #include "calls.h"
38 #include "stringpool.h"
39 #include "attribs.h"
40 #include "builtins.h"
42 static const char *ipa_ref_use_name[] = {"read","write","addr","alias","chkp"};
44 const char * const ld_plugin_symbol_resolution_names[]=
46 "",
47 "undef",
48 "prevailing_def",
49 "prevailing_def_ironly",
50 "preempted_reg",
51 "preempted_ir",
52 "resolved_ir",
53 "resolved_exec",
54 "resolved_dyn",
55 "prevailing_def_ironly_exp"
58 /* Follow the IDENTIFIER_TRANSPARENT_ALIAS chain starting at ALIAS
59 until we find an identifier that is not itself a transparent alias. */
61 static inline tree
62 ultimate_transparent_alias_target (tree alias)
64 tree target = alias;
66 while (IDENTIFIER_TRANSPARENT_ALIAS (target))
68 gcc_checking_assert (TREE_CHAIN (target));
69 target = TREE_CHAIN (target);
71 gcc_checking_assert (! IDENTIFIER_TRANSPARENT_ALIAS (target)
72 && ! TREE_CHAIN (target));
74 return target;
78 /* Hash asmnames ignoring the user specified marks. */
80 hashval_t
81 symbol_table::decl_assembler_name_hash (const_tree asmname)
83 if (IDENTIFIER_POINTER (asmname)[0] == '*')
85 const char *decl_str = IDENTIFIER_POINTER (asmname) + 1;
86 size_t ulp_len = strlen (user_label_prefix);
88 if (ulp_len == 0)
90 else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
91 decl_str += ulp_len;
93 return htab_hash_string (decl_str);
96 return htab_hash_string (IDENTIFIER_POINTER (asmname));
99 /* Return true if assembler names NAME1 and NAME2 leads to the same symbol
100 name. */
102 bool
103 symbol_table::assembler_names_equal_p (const char *name1, const char *name2)
105 if (name1 != name2)
107 if (name1[0] == '*')
109 size_t ulp_len = strlen (user_label_prefix);
111 name1 ++;
113 if (ulp_len == 0)
115 else if (strncmp (name1, user_label_prefix, ulp_len) == 0)
116 name1 += ulp_len;
117 else
118 return false;
120 if (name2[0] == '*')
122 size_t ulp_len = strlen (user_label_prefix);
124 name2 ++;
126 if (ulp_len == 0)
128 else if (strncmp (name2, user_label_prefix, ulp_len) == 0)
129 name2 += ulp_len;
130 else
131 return false;
133 return !strcmp (name1, name2);
135 return true;
138 /* Compare ASMNAME with the DECL_ASSEMBLER_NAME of DECL. */
140 bool
141 symbol_table::decl_assembler_name_equal (tree decl, const_tree asmname)
143 tree decl_asmname = DECL_ASSEMBLER_NAME (decl);
144 const char *decl_str;
145 const char *asmname_str;
147 if (decl_asmname == asmname)
148 return true;
150 decl_str = IDENTIFIER_POINTER (decl_asmname);
151 asmname_str = IDENTIFIER_POINTER (asmname);
152 return assembler_names_equal_p (decl_str, asmname_str);
156 /* Returns nonzero if P1 and P2 are equal. */
158 /* Insert NODE to assembler name hash. */
160 void
161 symbol_table::insert_to_assembler_name_hash (symtab_node *node,
162 bool with_clones)
164 if (is_a <varpool_node *> (node) && DECL_HARD_REGISTER (node->decl))
165 return;
166 gcc_checking_assert (!node->previous_sharing_asm_name
167 && !node->next_sharing_asm_name);
168 if (assembler_name_hash)
170 symtab_node **aslot;
171 cgraph_node *cnode;
172 tree decl = node->decl;
174 tree name = DECL_ASSEMBLER_NAME (node->decl);
176 /* C++ FE can produce decls without associated assembler name and insert
177 them to symtab to hold section or TLS information. */
178 if (!name)
179 return;
181 hashval_t hash = decl_assembler_name_hash (name);
182 aslot = assembler_name_hash->find_slot_with_hash (name, hash, INSERT);
183 gcc_assert (*aslot != node);
184 node->next_sharing_asm_name = (symtab_node *)*aslot;
185 if (*aslot != NULL)
186 (*aslot)->previous_sharing_asm_name = node;
187 *aslot = node;
189 /* Update also possible inline clones sharing a decl. */
190 cnode = dyn_cast <cgraph_node *> (node);
191 if (cnode && cnode->clones && with_clones)
192 for (cnode = cnode->clones; cnode; cnode = cnode->next_sibling_clone)
193 if (cnode->decl == decl)
194 insert_to_assembler_name_hash (cnode, true);
199 /* Remove NODE from assembler name hash. */
201 void
202 symbol_table::unlink_from_assembler_name_hash (symtab_node *node,
203 bool with_clones)
205 if (assembler_name_hash)
207 cgraph_node *cnode;
208 tree decl = node->decl;
210 if (node->next_sharing_asm_name)
211 node->next_sharing_asm_name->previous_sharing_asm_name
212 = node->previous_sharing_asm_name;
213 if (node->previous_sharing_asm_name)
215 node->previous_sharing_asm_name->next_sharing_asm_name
216 = node->next_sharing_asm_name;
218 else
220 tree name = DECL_ASSEMBLER_NAME (node->decl);
221 symtab_node **slot;
223 if (!name)
224 return;
226 hashval_t hash = decl_assembler_name_hash (name);
227 slot = assembler_name_hash->find_slot_with_hash (name, hash,
228 NO_INSERT);
229 gcc_assert (*slot == node);
230 if (!node->next_sharing_asm_name)
231 assembler_name_hash->clear_slot (slot);
232 else
233 *slot = node->next_sharing_asm_name;
235 node->next_sharing_asm_name = NULL;
236 node->previous_sharing_asm_name = NULL;
238 /* Update also possible inline clones sharing a decl. */
239 cnode = dyn_cast <cgraph_node *> (node);
240 if (cnode && cnode->clones && with_clones)
241 for (cnode = cnode->clones; cnode; cnode = cnode->next_sibling_clone)
242 if (cnode->decl == decl)
243 unlink_from_assembler_name_hash (cnode, true);
247 /* Arrange node to be first in its entry of assembler_name_hash. */
249 void
250 symbol_table::symtab_prevail_in_asm_name_hash (symtab_node *node)
252 unlink_from_assembler_name_hash (node, false);
253 insert_to_assembler_name_hash (node, false);
256 /* Initalize asm name hash unless. */
258 void
259 symbol_table::symtab_initialize_asm_name_hash (void)
261 symtab_node *node;
262 if (!assembler_name_hash)
264 assembler_name_hash = hash_table<asmname_hasher>::create_ggc (10);
265 FOR_EACH_SYMBOL (node)
266 insert_to_assembler_name_hash (node, false);
270 /* Set the DECL_ASSEMBLER_NAME and update symtab hashtables. */
272 void
273 symbol_table::change_decl_assembler_name (tree decl, tree name)
275 symtab_node *node = NULL;
277 /* We can have user ASM names on things, like global register variables, that
278 are not in the symbol table. */
279 if ((VAR_P (decl) && (TREE_STATIC (decl) || DECL_EXTERNAL (decl)))
280 || TREE_CODE (decl) == FUNCTION_DECL)
281 node = symtab_node::get (decl);
282 if (!DECL_ASSEMBLER_NAME_SET_P (decl))
284 SET_DECL_ASSEMBLER_NAME (decl, name);
285 if (node)
286 insert_to_assembler_name_hash (node, true);
288 else
290 if (name == DECL_ASSEMBLER_NAME (decl))
291 return;
293 tree alias = (IDENTIFIER_TRANSPARENT_ALIAS (DECL_ASSEMBLER_NAME (decl))
294 ? TREE_CHAIN (DECL_ASSEMBLER_NAME (decl))
295 : NULL);
296 if (node)
297 unlink_from_assembler_name_hash (node, true);
299 const char *old_name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
300 if (TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl))
301 && DECL_RTL_SET_P (decl))
302 warning (0, "%qD renamed after being referenced in assembly", decl);
304 SET_DECL_ASSEMBLER_NAME (decl, name);
305 if (alias)
307 IDENTIFIER_TRANSPARENT_ALIAS (name) = 1;
308 TREE_CHAIN (name) = alias;
310 /* If we change assembler name, also all transparent aliases must
311 be updated. There are three kinds - those having same assembler name,
312 those being renamed in varasm.c and weakref being renamed by the
313 assembler. */
314 if (node)
316 insert_to_assembler_name_hash (node, true);
317 ipa_ref *ref;
318 for (unsigned i = 0; node->iterate_direct_aliases (i, ref); i++)
320 struct symtab_node *alias = ref->referring;
321 if (alias->transparent_alias && !alias->weakref
322 && symbol_table::assembler_names_equal_p
323 (old_name, IDENTIFIER_POINTER (
324 DECL_ASSEMBLER_NAME (alias->decl))))
325 change_decl_assembler_name (alias->decl, name);
326 else if (alias->transparent_alias
327 && IDENTIFIER_TRANSPARENT_ALIAS (alias->decl))
329 gcc_assert (TREE_CHAIN (DECL_ASSEMBLER_NAME (alias->decl))
330 && IDENTIFIER_TRANSPARENT_ALIAS
331 (DECL_ASSEMBLER_NAME (alias->decl)));
333 TREE_CHAIN (DECL_ASSEMBLER_NAME (alias->decl)) =
334 ultimate_transparent_alias_target
335 (DECL_ASSEMBLER_NAME (node->decl));
337 #ifdef ASM_OUTPUT_WEAKREF
338 else gcc_assert (!alias->transparent_alias || alias->weakref);
339 #else
340 else gcc_assert (!alias->transparent_alias);
341 #endif
343 gcc_assert (!node->transparent_alias || !node->definition
344 || node->weakref
345 || TREE_CHAIN (DECL_ASSEMBLER_NAME (decl))
346 || symbol_table::assembler_names_equal_p
347 (IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
348 IDENTIFIER_POINTER
349 (DECL_ASSEMBLER_NAME
350 (node->get_alias_target ()->decl))));
355 /* Hash sections by their names. */
357 hashval_t
358 section_name_hasher::hash (section_hash_entry *n)
360 return htab_hash_string (n->name);
363 /* Return true if section P1 name equals to P2. */
365 bool
366 section_name_hasher::equal (section_hash_entry *n1, const char *name)
368 return n1->name == name || !strcmp (n1->name, name);
371 /* Add node into symbol table. This function is not used directly, but via
372 cgraph/varpool node creation routines. */
374 void
375 symtab_node::register_symbol (void)
377 symtab->register_symbol (this);
379 if (!decl->decl_with_vis.symtab_node)
380 decl->decl_with_vis.symtab_node = this;
382 ref_list.clear ();
384 /* Be sure to do this last; C++ FE might create new nodes via
385 DECL_ASSEMBLER_NAME langhook! */
386 symtab->insert_to_assembler_name_hash (this, false);
389 /* Remove NODE from same comdat group. */
391 void
392 symtab_node::remove_from_same_comdat_group (void)
394 if (same_comdat_group)
396 symtab_node *prev;
397 for (prev = same_comdat_group;
398 prev->same_comdat_group != this;
399 prev = prev->same_comdat_group)
401 if (same_comdat_group == prev)
402 prev->same_comdat_group = NULL;
403 else
404 prev->same_comdat_group = same_comdat_group;
405 same_comdat_group = NULL;
406 set_comdat_group (NULL);
410 /* Remove node from symbol table. This function is not used directly, but via
411 cgraph/varpool node removal routines. */
413 void
414 symtab_node::unregister (void)
416 remove_all_references ();
417 remove_all_referring ();
419 /* Remove reference to section. */
420 set_section_for_node (NULL);
422 remove_from_same_comdat_group ();
424 symtab->unregister (this);
426 /* During LTO symtab merging we temporarily corrupt decl to symtab node
427 hash. */
428 gcc_assert (decl->decl_with_vis.symtab_node || in_lto_p);
429 if (decl->decl_with_vis.symtab_node == this)
431 symtab_node *replacement_node = NULL;
432 if (cgraph_node *cnode = dyn_cast <cgraph_node *> (this))
433 replacement_node = cnode->find_replacement ();
434 decl->decl_with_vis.symtab_node = replacement_node;
436 if (!is_a <varpool_node *> (this) || !DECL_HARD_REGISTER (decl))
437 symtab->unlink_from_assembler_name_hash (this, false);
438 if (in_init_priority_hash)
439 symtab->init_priority_hash->remove (this);
443 /* Remove symbol from symbol table. */
445 void
446 symtab_node::remove (void)
448 if (cgraph_node *cnode = dyn_cast <cgraph_node *> (this))
449 cnode->remove ();
450 else if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
451 vnode->remove ();
454 /* Add NEW_ to the same comdat group that OLD is in. */
456 void
457 symtab_node::add_to_same_comdat_group (symtab_node *old_node)
459 gcc_assert (old_node->get_comdat_group ());
460 gcc_assert (!same_comdat_group);
461 gcc_assert (this != old_node);
463 set_comdat_group (old_node->get_comdat_group ());
464 same_comdat_group = old_node;
465 if (!old_node->same_comdat_group)
466 old_node->same_comdat_group = this;
467 else
469 symtab_node *n;
470 for (n = old_node->same_comdat_group;
471 n->same_comdat_group != old_node;
472 n = n->same_comdat_group)
474 n->same_comdat_group = this;
478 /* Dissolve the same_comdat_group list in which NODE resides. */
480 void
481 symtab_node::dissolve_same_comdat_group_list (void)
483 symtab_node *n = this;
484 symtab_node *next;
486 if (!same_comdat_group)
487 return;
490 next = n->same_comdat_group;
491 n->same_comdat_group = NULL;
492 /* Clear comdat_group for comdat locals, since
493 make_decl_local doesn't. */
494 if (!TREE_PUBLIC (n->decl))
495 n->set_comdat_group (NULL);
496 n = next;
498 while (n != this);
501 /* Return printable assembler name of NODE.
502 This function is used only for debugging. When assembler name
503 is unknown go with identifier name. */
505 const char *
506 symtab_node::asm_name () const
508 if (!DECL_ASSEMBLER_NAME_SET_P (decl))
509 return name ();
510 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
513 /* Return printable identifier name. */
515 const char *
516 symtab_node::name () const
518 if (!DECL_NAME (decl))
520 if (DECL_ASSEMBLER_NAME_SET_P (decl))
521 return asm_name ();
522 else
523 return "<unnamed>";
525 return lang_hooks.decl_printable_name (decl, 2);
528 const char *
529 symtab_node::get_dump_name (bool asm_name_p) const
531 #define EXTRA 16
532 const char *fname = asm_name_p ? asm_name () : name ();
533 unsigned l = strlen (fname);
535 char *s = (char *)ggc_internal_cleared_alloc (l + EXTRA);
536 snprintf (s, l + EXTRA, "%s/%d", fname, order);
538 return s;
541 const char *
542 symtab_node::dump_name () const
544 return get_dump_name (false);
547 const char *
548 symtab_node::dump_asm_name () const
550 return get_dump_name (true);
553 /* Return ipa reference from this symtab_node to
554 REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
555 of the use. */
557 ipa_ref *
558 symtab_node::create_reference (symtab_node *referred_node,
559 enum ipa_ref_use use_type)
561 return create_reference (referred_node, use_type, NULL);
565 /* Return ipa reference from this symtab_node to
566 REFERED_NODE or REFERED_VARPOOL_NODE. USE_TYPE specify type
567 of the use and STMT the statement (if it exists). */
569 ipa_ref *
570 symtab_node::create_reference (symtab_node *referred_node,
571 enum ipa_ref_use use_type, gimple *stmt)
573 ipa_ref *ref = NULL, *ref2 = NULL;
574 ipa_ref_list *list, *list2;
575 ipa_ref_t *old_references;
577 gcc_checking_assert (!stmt || is_a <cgraph_node *> (this));
578 gcc_checking_assert (use_type != IPA_REF_ALIAS || !stmt);
580 list = &ref_list;
581 old_references = vec_safe_address (list->references);
582 vec_safe_grow (list->references, vec_safe_length (list->references) + 1);
583 ref = &list->references->last ();
585 list2 = &referred_node->ref_list;
587 /* IPA_REF_ALIAS is always inserted at the beginning of the list. */
588 if(use_type == IPA_REF_ALIAS)
590 list2->referring.safe_insert (0, ref);
591 ref->referred_index = 0;
593 for (unsigned int i = 1; i < list2->referring.length (); i++)
594 list2->referring[i]->referred_index = i;
596 else
598 list2->referring.safe_push (ref);
599 ref->referred_index = list2->referring.length () - 1;
602 ref->referring = this;
603 ref->referred = referred_node;
604 ref->stmt = stmt;
605 ref->lto_stmt_uid = 0;
606 ref->use = use_type;
607 ref->speculative = 0;
609 /* If vector was moved in memory, update pointers. */
610 if (old_references != list->references->address ())
612 int i;
613 for (i = 0; iterate_reference(i, ref2); i++)
614 ref2->referred_ref_list ()->referring[ref2->referred_index] = ref2;
616 return ref;
619 ipa_ref *
620 symtab_node::maybe_create_reference (tree val, gimple *stmt)
622 STRIP_NOPS (val);
623 ipa_ref_use use_type;
625 switch (TREE_CODE (val))
627 case VAR_DECL:
628 use_type = IPA_REF_LOAD;
629 break;
630 case ADDR_EXPR:
631 use_type = IPA_REF_ADDR;
632 break;
633 default:
634 gcc_assert (!handled_component_p (val));
635 return NULL;
638 val = get_base_var (val);
639 if (val && VAR_OR_FUNCTION_DECL_P (val))
641 symtab_node *referred = symtab_node::get (val);
642 gcc_checking_assert (referred);
643 return create_reference (referred, use_type, stmt);
645 return NULL;
648 /* Clone all references from symtab NODE to this symtab_node. */
650 void
651 symtab_node::clone_references (symtab_node *node)
653 ipa_ref *ref = NULL, *ref2 = NULL;
654 int i;
655 for (i = 0; node->iterate_reference (i, ref); i++)
657 bool speculative = ref->speculative;
658 unsigned int stmt_uid = ref->lto_stmt_uid;
660 ref2 = create_reference (ref->referred, ref->use, ref->stmt);
661 ref2->speculative = speculative;
662 ref2->lto_stmt_uid = stmt_uid;
666 /* Clone all referring from symtab NODE to this symtab_node. */
668 void
669 symtab_node::clone_referring (symtab_node *node)
671 ipa_ref *ref = NULL, *ref2 = NULL;
672 int i;
673 for (i = 0; node->iterate_referring(i, ref); i++)
675 bool speculative = ref->speculative;
676 unsigned int stmt_uid = ref->lto_stmt_uid;
678 ref2 = ref->referring->create_reference (this, ref->use, ref->stmt);
679 ref2->speculative = speculative;
680 ref2->lto_stmt_uid = stmt_uid;
684 /* Clone reference REF to this symtab_node and set its stmt to STMT. */
686 ipa_ref *
687 symtab_node::clone_reference (ipa_ref *ref, gimple *stmt)
689 bool speculative = ref->speculative;
690 unsigned int stmt_uid = ref->lto_stmt_uid;
691 ipa_ref *ref2;
693 ref2 = create_reference (ref->referred, ref->use, stmt);
694 ref2->speculative = speculative;
695 ref2->lto_stmt_uid = stmt_uid;
696 return ref2;
699 /* Find the structure describing a reference to REFERRED_NODE
700 and associated with statement STMT. */
702 ipa_ref *
703 symtab_node::find_reference (symtab_node *referred_node,
704 gimple *stmt, unsigned int lto_stmt_uid)
706 ipa_ref *r = NULL;
707 int i;
709 for (i = 0; iterate_reference (i, r); i++)
710 if (r->referred == referred_node
711 && !r->speculative
712 && ((stmt && r->stmt == stmt)
713 || (lto_stmt_uid && r->lto_stmt_uid == lto_stmt_uid)
714 || (!stmt && !lto_stmt_uid && !r->stmt && !r->lto_stmt_uid)))
715 return r;
716 return NULL;
719 /* Remove all references that are associated with statement STMT. */
721 void
722 symtab_node::remove_stmt_references (gimple *stmt)
724 ipa_ref *r = NULL;
725 int i = 0;
727 while (iterate_reference (i, r))
728 if (r->stmt == stmt)
729 r->remove_reference ();
730 else
731 i++;
734 /* Remove all stmt references in non-speculative references.
735 Those are not maintained during inlining & clonning.
736 The exception are speculative references that are updated along
737 with callgraph edges associated with them. */
739 void
740 symtab_node::clear_stmts_in_references (void)
742 ipa_ref *r = NULL;
743 int i;
745 for (i = 0; iterate_reference (i, r); i++)
746 if (!r->speculative)
748 r->stmt = NULL;
749 r->lto_stmt_uid = 0;
753 /* Remove all references in ref list. */
755 void
756 symtab_node::remove_all_references (void)
758 while (vec_safe_length (ref_list.references))
759 ref_list.references->last ().remove_reference ();
760 vec_free (ref_list.references);
763 /* Remove all referring items in ref list. */
765 void
766 symtab_node::remove_all_referring (void)
768 while (ref_list.referring.length ())
769 ref_list.referring.last ()->remove_reference ();
770 ref_list.referring.release ();
773 /* Dump references in ref list to FILE. */
775 void
776 symtab_node::dump_references (FILE *file)
778 ipa_ref *ref = NULL;
779 int i;
780 for (i = 0; iterate_reference (i, ref); i++)
782 fprintf (file, "%s (%s)",
783 ref->referred->dump_asm_name (),
784 ipa_ref_use_name [ref->use]);
785 if (ref->speculative)
786 fprintf (file, " (speculative)");
788 fprintf (file, "\n");
791 /* Dump referring in list to FILE. */
793 void
794 symtab_node::dump_referring (FILE *file)
796 ipa_ref *ref = NULL;
797 int i;
798 for (i = 0; iterate_referring(i, ref); i++)
800 fprintf (file, "%s (%s)",
801 ref->referring->dump_asm_name (),
802 ipa_ref_use_name [ref->use]);
803 if (ref->speculative)
804 fprintf (file, " (speculative)");
806 fprintf (file, "\n");
809 static const char * const symtab_type_names[] = {"symbol", "function", "variable"};
811 /* Dump base fields of symtab nodes to F. Not to be used directly. */
813 void
814 symtab_node::dump_base (FILE *f)
816 static const char * const visibility_types[] = {
817 "default", "protected", "hidden", "internal"
820 fprintf (f, "%s (%s)", dump_asm_name (), name ());
821 dump_addr (f, " @", (void *)this);
822 fprintf (f, "\n Type: %s", symtab_type_names[type]);
824 if (definition)
825 fprintf (f, " definition");
826 if (analyzed)
827 fprintf (f, " analyzed");
828 if (alias)
829 fprintf (f, " alias");
830 if (transparent_alias)
831 fprintf (f, " transparent_alias");
832 if (weakref)
833 fprintf (f, " weakref");
834 if (cpp_implicit_alias)
835 fprintf (f, " cpp_implicit_alias");
836 if (alias_target)
837 fprintf (f, " target:%s",
838 DECL_P (alias_target)
839 ? IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME
840 (alias_target))
841 : IDENTIFIER_POINTER (alias_target));
842 if (body_removed)
843 fprintf (f, "\n Body removed by symtab_remove_unreachable_nodes");
844 fprintf (f, "\n Visibility:");
845 if (in_other_partition)
846 fprintf (f, " in_other_partition");
847 if (used_from_other_partition)
848 fprintf (f, " used_from_other_partition");
849 if (force_output)
850 fprintf (f, " force_output");
851 if (forced_by_abi)
852 fprintf (f, " forced_by_abi");
853 if (externally_visible)
854 fprintf (f, " externally_visible");
855 if (no_reorder)
856 fprintf (f, " no_reorder");
857 if (resolution != LDPR_UNKNOWN)
858 fprintf (f, " %s",
859 ld_plugin_symbol_resolution_names[(int)resolution]);
860 if (TREE_ASM_WRITTEN (decl))
861 fprintf (f, " asm_written");
862 if (DECL_EXTERNAL (decl))
863 fprintf (f, " external");
864 if (TREE_PUBLIC (decl))
865 fprintf (f, " public");
866 if (DECL_COMMON (decl))
867 fprintf (f, " common");
868 if (DECL_WEAK (decl))
869 fprintf (f, " weak");
870 if (DECL_DLLIMPORT_P (decl))
871 fprintf (f, " dll_import");
872 if (DECL_COMDAT (decl))
873 fprintf (f, " comdat");
874 if (get_comdat_group ())
875 fprintf (f, " comdat_group:%s",
876 IDENTIFIER_POINTER (get_comdat_group_id ()));
877 if (DECL_ONE_ONLY (decl))
878 fprintf (f, " one_only");
879 if (get_section ())
880 fprintf (f, " section:%s",
881 get_section ());
882 if (implicit_section)
883 fprintf (f," (implicit_section)");
884 if (DECL_VISIBILITY_SPECIFIED (decl))
885 fprintf (f, " visibility_specified");
886 if (DECL_VISIBILITY (decl))
887 fprintf (f, " visibility:%s",
888 visibility_types [DECL_VISIBILITY (decl)]);
889 if (DECL_VIRTUAL_P (decl))
890 fprintf (f, " virtual");
891 if (DECL_ARTIFICIAL (decl))
892 fprintf (f, " artificial");
893 if (TREE_CODE (decl) == FUNCTION_DECL)
895 if (DECL_STATIC_CONSTRUCTOR (decl))
896 fprintf (f, " constructor");
897 if (DECL_STATIC_DESTRUCTOR (decl))
898 fprintf (f, " destructor");
900 fprintf (f, "\n");
902 if (same_comdat_group)
903 fprintf (f, " Same comdat group as: %s\n",
904 same_comdat_group->dump_asm_name ());
905 if (next_sharing_asm_name)
906 fprintf (f, " next sharing asm name: %i\n",
907 next_sharing_asm_name->order);
908 if (previous_sharing_asm_name)
909 fprintf (f, " previous sharing asm name: %i\n",
910 previous_sharing_asm_name->order);
912 if (address_taken)
913 fprintf (f, " Address is taken.\n");
914 if (aux)
916 fprintf (f, " Aux:");
917 dump_addr (f, " @", (void *)aux);
918 fprintf (f, "\n");
921 fprintf (f, " References: ");
922 dump_references (f);
923 fprintf (f, " Referring: ");
924 dump_referring (f);
925 if (lto_file_data)
926 fprintf (f, " Read from file: %s\n",
927 lto_file_data->file_name);
930 /* Dump symtab node to F. */
932 void
933 symtab_node::dump (FILE *f)
935 if (cgraph_node *cnode = dyn_cast <cgraph_node *> (this))
936 cnode->dump (f);
937 else if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
938 vnode->dump (f);
941 void
942 symbol_table::dump (FILE *f)
944 symtab_node *node;
945 fprintf (f, "Symbol table:\n\n");
946 FOR_EACH_SYMBOL (node)
947 node->dump (f);
950 DEBUG_FUNCTION void
951 symbol_table::debug (void)
953 dump (stderr);
956 /* Return the cgraph node that has ASMNAME for its DECL_ASSEMBLER_NAME.
957 Return NULL if there's no such node. */
959 symtab_node *
960 symtab_node::get_for_asmname (const_tree asmname)
962 symtab_node *node;
964 symtab->symtab_initialize_asm_name_hash ();
965 hashval_t hash = symtab->decl_assembler_name_hash (asmname);
966 symtab_node **slot
967 = symtab->assembler_name_hash->find_slot_with_hash (asmname, hash,
968 NO_INSERT);
970 if (slot)
972 node = *slot;
973 return node;
975 return NULL;
978 /* Dump symtab node NODE to stderr. */
980 DEBUG_FUNCTION void
981 symtab_node::debug (void)
983 dump (stderr);
986 /* Verify common part of symtab nodes. */
988 DEBUG_FUNCTION bool
989 symtab_node::verify_base (void)
991 bool error_found = false;
992 symtab_node *hashed_node;
994 if (is_a <cgraph_node *> (this))
996 if (TREE_CODE (decl) != FUNCTION_DECL)
998 error ("function symbol is not function");
999 error_found = true;
1002 else if (is_a <varpool_node *> (this))
1004 if (!VAR_P (decl))
1006 error ("variable symbol is not variable");
1007 error_found = true;
1010 else
1012 error ("node has unknown type");
1013 error_found = true;
1016 if (symtab->state != LTO_STREAMING)
1018 hashed_node = symtab_node::get (decl);
1019 if (!hashed_node)
1021 error ("node not found node->decl->decl_with_vis.symtab_node");
1022 error_found = true;
1024 if (hashed_node != this
1025 && (!is_a <cgraph_node *> (this)
1026 || !dyn_cast <cgraph_node *> (this)->clone_of
1027 || dyn_cast <cgraph_node *> (this)->clone_of->decl != decl))
1029 error ("node differs from node->decl->decl_with_vis.symtab_node");
1030 error_found = true;
1033 if (symtab->assembler_name_hash)
1035 hashed_node = symtab_node::get_for_asmname (DECL_ASSEMBLER_NAME (decl));
1036 if (hashed_node && hashed_node->previous_sharing_asm_name)
1038 error ("assembler name hash list corrupted");
1039 error_found = true;
1041 while (hashed_node)
1043 if (hashed_node == this)
1044 break;
1045 hashed_node = hashed_node->next_sharing_asm_name;
1047 if (!hashed_node
1048 && !(is_a <varpool_node *> (this)
1049 && DECL_HARD_REGISTER (decl)))
1051 error ("node not found in symtab assembler name hash");
1052 error_found = true;
1055 if (previous_sharing_asm_name
1056 && previous_sharing_asm_name->next_sharing_asm_name != this)
1058 error ("double linked list of assembler names corrupted");
1059 error_found = true;
1061 if (body_removed && definition)
1063 error ("node has body_removed but is definition");
1064 error_found = true;
1066 if (analyzed && !definition)
1068 error ("node is analyzed but it is not a definition");
1069 error_found = true;
1071 if (cpp_implicit_alias && !alias)
1073 error ("node is alias but not implicit alias");
1074 error_found = true;
1076 if (alias && !definition && !weakref)
1078 error ("node is alias but not definition");
1079 error_found = true;
1081 if (weakref && !transparent_alias)
1083 error ("node is weakref but not an transparent_alias");
1084 error_found = true;
1086 if (transparent_alias && !alias)
1088 error ("node is transparent_alias but not an alias");
1089 error_found = true;
1091 if (same_comdat_group)
1093 symtab_node *n = same_comdat_group;
1095 if (!n->get_comdat_group ())
1097 error ("node is in same_comdat_group list but has no comdat_group");
1098 error_found = true;
1100 if (n->get_comdat_group () != get_comdat_group ())
1102 error ("same_comdat_group list across different groups");
1103 error_found = true;
1105 if (n->type != type)
1107 error ("mixing different types of symbol in same comdat groups is not supported");
1108 error_found = true;
1110 if (n == this)
1112 error ("node is alone in a comdat group");
1113 error_found = true;
1117 if (!n->same_comdat_group)
1119 error ("same_comdat_group is not a circular list");
1120 error_found = true;
1121 break;
1123 n = n->same_comdat_group;
1125 while (n != this);
1126 if (comdat_local_p ())
1128 ipa_ref *ref = NULL;
1130 for (int i = 0; iterate_referring (i, ref); ++i)
1132 if (!in_same_comdat_group_p (ref->referring))
1134 error ("comdat-local symbol referred to by %s outside its "
1135 "comdat",
1136 identifier_to_locale (ref->referring->name()));
1137 error_found = true;
1142 if (implicit_section && !get_section ())
1144 error ("implicit_section flag is set but section isn't");
1145 error_found = true;
1147 if (get_section () && get_comdat_group ()
1148 && !implicit_section
1149 && !lookup_attribute ("section", DECL_ATTRIBUTES (decl)))
1151 error ("Both section and comdat group is set");
1152 error_found = true;
1154 /* TODO: Add string table for sections, so we do not keep holding duplicated
1155 strings. */
1156 if (alias && definition
1157 && get_section () != get_alias_target ()->get_section ()
1158 && (!get_section()
1159 || !get_alias_target ()->get_section ()
1160 || strcmp (get_section(),
1161 get_alias_target ()->get_section ())))
1163 error ("Alias and target's section differs");
1164 get_alias_target ()->dump (stderr);
1165 error_found = true;
1167 if (alias && definition
1168 && get_comdat_group () != get_alias_target ()->get_comdat_group ())
1170 error ("Alias and target's comdat groups differs");
1171 get_alias_target ()->dump (stderr);
1172 error_found = true;
1174 if (transparent_alias && definition && !weakref)
1176 symtab_node *to = get_alias_target ();
1177 const char *name1
1178 = IDENTIFIER_POINTER (
1179 ultimate_transparent_alias_target (DECL_ASSEMBLER_NAME (decl)));
1180 const char *name2
1181 = IDENTIFIER_POINTER (
1182 ultimate_transparent_alias_target (DECL_ASSEMBLER_NAME (to->decl)));
1183 if (!symbol_table::assembler_names_equal_p (name1, name2))
1185 error ("Transparent alias and target's assembler names differs");
1186 get_alias_target ()->dump (stderr);
1187 error_found = true;
1190 if (transparent_alias && definition
1191 && get_alias_target()->transparent_alias && get_alias_target()->analyzed)
1193 error ("Chained transparent aliases");
1194 get_alias_target ()->dump (stderr);
1195 error_found = true;
1198 return error_found;
1201 /* Verify consistency of NODE. */
1203 DEBUG_FUNCTION void
1204 symtab_node::verify (void)
1206 if (seen_error ())
1207 return;
1209 timevar_push (TV_CGRAPH_VERIFY);
1210 if (cgraph_node *node = dyn_cast <cgraph_node *> (this))
1211 node->verify_node ();
1212 else
1213 if (verify_base ())
1215 debug ();
1216 internal_error ("symtab_node::verify failed");
1218 timevar_pop (TV_CGRAPH_VERIFY);
1221 /* Verify symbol table for internal consistency. */
1223 DEBUG_FUNCTION void
1224 symtab_node::verify_symtab_nodes (void)
1226 symtab_node *node;
1227 hash_map<tree, symtab_node *> comdat_head_map (251);
1229 FOR_EACH_SYMBOL (node)
1231 node->verify ();
1232 if (node->get_comdat_group ())
1234 symtab_node **entry, *s;
1235 bool existed;
1237 entry = &comdat_head_map.get_or_insert (node->get_comdat_group (),
1238 &existed);
1239 if (!existed)
1240 *entry = node;
1241 else if (!DECL_EXTERNAL (node->decl))
1243 for (s = (*entry)->same_comdat_group;
1244 s != NULL && s != node && s != *entry;
1245 s = s->same_comdat_group)
1247 if (!s || s == *entry)
1249 error ("Two symbols with same comdat_group are not linked by "
1250 "the same_comdat_group list.");
1251 (*entry)->debug ();
1252 node->debug ();
1253 internal_error ("symtab_node::verify failed");
1260 /* Make DECL local. FIXME: We shouldn't need to mess with rtl this early,
1261 but other code such as notice_global_symbol generates rtl. */
1263 void
1264 symtab_node::make_decl_local (void)
1266 rtx rtl, symbol;
1268 if (weakref)
1270 weakref = false;
1271 IDENTIFIER_TRANSPARENT_ALIAS (DECL_ASSEMBLER_NAME (decl)) = 0;
1272 TREE_CHAIN (DECL_ASSEMBLER_NAME (decl)) = NULL_TREE;
1273 symtab->change_decl_assembler_name
1274 (decl, DECL_ASSEMBLER_NAME (get_alias_target ()->decl));
1275 DECL_ATTRIBUTES (decl) = remove_attribute ("weakref",
1276 DECL_ATTRIBUTES (decl));
1278 /* Avoid clearing comdat_groups on comdat-local decls. */
1279 else if (TREE_PUBLIC (decl) == 0)
1280 return;
1282 /* Localizing a symbol also make all its transparent aliases local. */
1283 ipa_ref *ref;
1284 for (unsigned i = 0; iterate_direct_aliases (i, ref); i++)
1286 struct symtab_node *alias = ref->referring;
1287 if (alias->transparent_alias)
1288 alias->make_decl_local ();
1291 if (VAR_P (decl))
1293 DECL_COMMON (decl) = 0;
1294 /* ADDRESSABLE flag is not defined for public symbols. */
1295 TREE_ADDRESSABLE (decl) = 1;
1296 TREE_STATIC (decl) = 1;
1298 else
1299 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
1301 DECL_COMDAT (decl) = 0;
1302 DECL_WEAK (decl) = 0;
1303 DECL_EXTERNAL (decl) = 0;
1304 DECL_VISIBILITY_SPECIFIED (decl) = 0;
1305 DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
1306 TREE_PUBLIC (decl) = 0;
1307 DECL_DLLIMPORT_P (decl) = 0;
1308 if (!DECL_RTL_SET_P (decl))
1309 return;
1311 /* Update rtl flags. */
1312 make_decl_rtl (decl);
1314 rtl = DECL_RTL (decl);
1315 if (!MEM_P (rtl))
1316 return;
1318 symbol = XEXP (rtl, 0);
1319 if (GET_CODE (symbol) != SYMBOL_REF)
1320 return;
1322 SYMBOL_REF_WEAK (symbol) = DECL_WEAK (decl);
1325 /* Copy visibility from N.
1326 This is useful when THIS becomes a transparent alias of N. */
1328 void
1329 symtab_node::copy_visibility_from (symtab_node *n)
1331 gcc_checking_assert (n->weakref == weakref);
1333 ipa_ref *ref;
1334 for (unsigned i = 0; iterate_direct_aliases (i, ref); i++)
1336 struct symtab_node *alias = ref->referring;
1337 if (alias->transparent_alias)
1338 alias->copy_visibility_from (n);
1341 if (VAR_P (decl))
1343 DECL_COMMON (decl) = DECL_COMMON (n->decl);
1344 /* ADDRESSABLE flag is not defined for public symbols. */
1345 if (TREE_PUBLIC (decl) && !TREE_PUBLIC (n->decl))
1346 TREE_ADDRESSABLE (decl) = 1;
1347 TREE_STATIC (decl) = TREE_STATIC (n->decl);
1349 else gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
1351 DECL_COMDAT (decl) = DECL_COMDAT (n->decl);
1352 DECL_WEAK (decl) = DECL_WEAK (n->decl);
1353 DECL_EXTERNAL (decl) = DECL_EXTERNAL (n->decl);
1354 DECL_VISIBILITY_SPECIFIED (decl) = DECL_VISIBILITY_SPECIFIED (n->decl);
1355 DECL_VISIBILITY (decl) = DECL_VISIBILITY (n->decl);
1356 TREE_PUBLIC (decl) = TREE_PUBLIC (n->decl);
1357 DECL_DLLIMPORT_P (decl) = DECL_DLLIMPORT_P (n->decl);
1358 resolution = n->resolution;
1359 set_comdat_group (n->get_comdat_group ());
1360 call_for_symbol_and_aliases (symtab_node::set_section,
1361 const_cast<char *>(n->get_section ()), true);
1362 externally_visible = n->externally_visible;
1363 if (!DECL_RTL_SET_P (decl))
1364 return;
1366 /* Update rtl flags. */
1367 make_decl_rtl (decl);
1369 rtx rtl = DECL_RTL (decl);
1370 if (!MEM_P (rtl))
1371 return;
1373 rtx symbol = XEXP (rtl, 0);
1374 if (GET_CODE (symbol) != SYMBOL_REF)
1375 return;
1377 SYMBOL_REF_WEAK (symbol) = DECL_WEAK (decl);
1380 /* Walk the alias chain to return the symbol NODE is alias of.
1381 If NODE is not an alias, return NODE.
1382 Assumes NODE is known to be alias. */
1384 symtab_node *
1385 symtab_node::ultimate_alias_target_1 (enum availability *availability,
1386 symtab_node *ref)
1388 bool transparent_p = false;
1390 /* To determine visibility of the target, we follow ELF semantic of aliases.
1391 Here alias is an alternative assembler name of a given definition. Its
1392 availability prevails the availability of its target (i.e. static alias of
1393 weak definition is available.
1395 Transaparent alias is just alternative anme of a given symbol used within
1396 one compilation unit and is translated prior hitting the object file. It
1397 inherits the visibility of its target.
1398 Weakref is a different animal (and noweak definition is weak).
1400 If we ever get into supporting targets with different semantics, a target
1401 hook will be needed here. */
1403 if (availability)
1405 transparent_p = transparent_alias;
1406 if (!transparent_p)
1407 *availability = get_availability (ref);
1408 else
1409 *availability = AVAIL_NOT_AVAILABLE;
1412 symtab_node *node = this;
1413 while (node)
1415 if (node->alias && node->analyzed)
1416 node = node->get_alias_target ();
1417 else
1419 if (!availability || (!transparent_p && node->analyzed))
1421 else if (node->analyzed && !node->transparent_alias)
1422 *availability = node->get_availability (ref);
1423 else
1424 *availability = AVAIL_NOT_AVAILABLE;
1425 return node;
1427 if (node && availability && transparent_p
1428 && node->transparent_alias)
1430 *availability = node->get_availability (ref);
1431 transparent_p = false;
1434 if (availability)
1435 *availability = AVAIL_NOT_AVAILABLE;
1436 return NULL;
1439 /* C++ FE sometimes change linkage flags after producing same body aliases.
1441 FIXME: C++ produce implicit aliases for virtual functions and vtables that
1442 are obviously equivalent. The way it is doing so is however somewhat
1443 kludgy and interferes with the visibility code. As a result we need to
1444 copy the visibility from the target to get things right. */
1446 void
1447 symtab_node::fixup_same_cpp_alias_visibility (symtab_node *target)
1449 if (is_a <cgraph_node *> (this))
1451 DECL_DECLARED_INLINE_P (decl)
1452 = DECL_DECLARED_INLINE_P (target->decl);
1453 DECL_DISREGARD_INLINE_LIMITS (decl)
1454 = DECL_DISREGARD_INLINE_LIMITS (target->decl);
1456 /* FIXME: It is not really clear why those flags should not be copied for
1457 functions, too. */
1458 else
1460 DECL_WEAK (decl) = DECL_WEAK (target->decl);
1461 DECL_EXTERNAL (decl) = DECL_EXTERNAL (target->decl);
1462 DECL_VISIBILITY (decl) = DECL_VISIBILITY (target->decl);
1464 if (TREE_PUBLIC (decl))
1466 tree group;
1468 DECL_EXTERNAL (decl) = DECL_EXTERNAL (target->decl);
1469 DECL_COMDAT (decl) = DECL_COMDAT (target->decl);
1470 group = target->get_comdat_group ();
1471 set_comdat_group (group);
1472 if (group && !same_comdat_group)
1473 add_to_same_comdat_group (target);
1475 externally_visible = target->externally_visible;
1478 /* Set section, do not recurse into aliases.
1479 When one wants to change section of a symbol and its aliases,
1480 use set_section. */
1482 void
1483 symtab_node::set_section_for_node (const char *section)
1485 const char *current = get_section ();
1486 section_hash_entry **slot;
1488 if (current == section
1489 || (current && section
1490 && !strcmp (current, section)))
1491 return;
1493 if (current)
1495 x_section->ref_count--;
1496 if (!x_section->ref_count)
1498 hashval_t hash = htab_hash_string (x_section->name);
1499 slot = symtab->section_hash->find_slot_with_hash (x_section->name,
1500 hash, INSERT);
1501 ggc_free (x_section);
1502 symtab->section_hash->clear_slot (slot);
1504 x_section = NULL;
1506 if (!section)
1508 implicit_section = false;
1509 return;
1511 if (!symtab->section_hash)
1512 symtab->section_hash = hash_table<section_name_hasher>::create_ggc (10);
1513 slot = symtab->section_hash->find_slot_with_hash (section,
1514 htab_hash_string (section),
1515 INSERT);
1516 if (*slot)
1517 x_section = (section_hash_entry *)*slot;
1518 else
1520 int len = strlen (section);
1521 *slot = x_section = ggc_cleared_alloc<section_hash_entry> ();
1522 x_section->name = ggc_vec_alloc<char> (len + 1);
1523 memcpy (x_section->name, section, len + 1);
1525 x_section->ref_count++;
1528 /* Worker for set_section. */
1530 bool
1531 symtab_node::set_section (symtab_node *n, void *s)
1533 n->set_section_for_node ((char *)s);
1534 return false;
1537 /* Set section of symbol and its aliases. */
1539 void
1540 symtab_node::set_section (const char *section)
1542 gcc_assert (!this->alias);
1543 call_for_symbol_and_aliases
1544 (symtab_node::set_section, const_cast<char *>(section), true);
1547 /* Return the initialization priority. */
1549 priority_type
1550 symtab_node::get_init_priority ()
1552 if (!this->in_init_priority_hash)
1553 return DEFAULT_INIT_PRIORITY;
1555 symbol_priority_map *h = symtab->init_priority_hash->get (this);
1556 return h ? h->init : DEFAULT_INIT_PRIORITY;
1559 /* Return the finalization priority. */
1561 priority_type
1562 cgraph_node::get_fini_priority ()
1564 if (!this->in_init_priority_hash)
1565 return DEFAULT_INIT_PRIORITY;
1566 symbol_priority_map *h = symtab->init_priority_hash->get (this);
1567 return h ? h->fini : DEFAULT_INIT_PRIORITY;
1570 /* Return the initialization and finalization priority information for
1571 DECL. If there is no previous priority information, a freshly
1572 allocated structure is returned. */
1574 symbol_priority_map *
1575 symtab_node::priority_info (void)
1577 if (!symtab->init_priority_hash)
1578 symtab->init_priority_hash = hash_map<symtab_node *, symbol_priority_map>::create_ggc (13);
1580 bool existed;
1581 symbol_priority_map *h
1582 = &symtab->init_priority_hash->get_or_insert (this, &existed);
1583 if (!existed)
1585 h->init = DEFAULT_INIT_PRIORITY;
1586 h->fini = DEFAULT_INIT_PRIORITY;
1587 in_init_priority_hash = true;
1590 return h;
1593 /* Set initialization priority to PRIORITY. */
1595 void
1596 symtab_node::set_init_priority (priority_type priority)
1598 symbol_priority_map *h;
1600 if (is_a <cgraph_node *> (this))
1601 gcc_assert (DECL_STATIC_CONSTRUCTOR (this->decl));
1603 if (priority == DEFAULT_INIT_PRIORITY)
1605 gcc_assert (get_init_priority() == priority);
1606 return;
1608 h = priority_info ();
1609 h->init = priority;
1612 /* Set fialization priority to PRIORITY. */
1614 void
1615 cgraph_node::set_fini_priority (priority_type priority)
1617 symbol_priority_map *h;
1619 gcc_assert (DECL_STATIC_DESTRUCTOR (this->decl));
1621 if (priority == DEFAULT_INIT_PRIORITY)
1623 gcc_assert (get_fini_priority() == priority);
1624 return;
1626 h = priority_info ();
1627 h->fini = priority;
1630 /* Worker for symtab_resolve_alias. */
1632 bool
1633 symtab_node::set_implicit_section (symtab_node *n,
1634 void *data ATTRIBUTE_UNUSED)
1636 n->implicit_section = true;
1637 return false;
1640 /* Add reference recording that symtab node is alias of TARGET.
1641 The function can fail in the case of aliasing cycles; in this case
1642 it returns false. */
1644 bool
1645 symtab_node::resolve_alias (symtab_node *target, bool transparent)
1647 symtab_node *n;
1649 gcc_assert (!analyzed && !vec_safe_length (ref_list.references));
1651 /* Never let cycles to creep into the symbol table alias references;
1652 those will make alias walkers to be infinite. */
1653 for (n = target; n && n->alias;
1654 n = n->analyzed ? n->get_alias_target () : NULL)
1655 if (n == this)
1657 if (is_a <cgraph_node *> (this))
1658 error ("function %q+D part of alias cycle", decl);
1659 else if (is_a <varpool_node *> (this))
1660 error ("variable %q+D part of alias cycle", decl);
1661 else
1662 gcc_unreachable ();
1663 alias = false;
1664 return false;
1667 /* "analyze" the node - i.e. mark the reference. */
1668 definition = true;
1669 alias = true;
1670 analyzed = true;
1671 transparent |= transparent_alias;
1672 transparent_alias = transparent;
1673 if (transparent)
1674 while (target->transparent_alias && target->analyzed)
1675 target = target->get_alias_target ();
1676 create_reference (target, IPA_REF_ALIAS, NULL);
1678 /* Add alias into the comdat group of its target unless it is already there. */
1679 if (same_comdat_group)
1680 remove_from_same_comdat_group ();
1681 set_comdat_group (NULL);
1682 if (target->get_comdat_group ())
1683 add_to_same_comdat_group (target);
1685 if ((get_section () != target->get_section ()
1686 || target->get_comdat_group ()) && get_section () && !implicit_section)
1688 error ("section of alias %q+D must match section of its target", decl);
1690 call_for_symbol_and_aliases (symtab_node::set_section,
1691 const_cast<char *>(target->get_section ()), true);
1692 if (target->implicit_section)
1693 call_for_symbol_and_aliases (set_implicit_section, NULL, true);
1695 /* Alias targets become redundant after alias is resolved into an reference.
1696 We do not want to keep it around or we would have to mind updating them
1697 when renaming symbols. */
1698 alias_target = NULL;
1700 if (!transparent && cpp_implicit_alias && symtab->state >= CONSTRUCTION)
1701 fixup_same_cpp_alias_visibility (target);
1703 /* If alias has address taken, so does the target. */
1704 if (address_taken)
1705 target->ultimate_alias_target ()->address_taken = true;
1707 /* All non-transparent aliases of THIS are now in fact aliases of TARGET.
1708 If alias is transparent, also all transparent aliases of THIS are now
1709 aliases of TARGET.
1710 Also merge same comdat group lists. */
1711 ipa_ref *ref;
1712 for (unsigned i = 0; iterate_direct_aliases (i, ref);)
1714 struct symtab_node *alias_alias = ref->referring;
1715 if (alias_alias->get_comdat_group ())
1717 alias_alias->remove_from_same_comdat_group ();
1718 alias_alias->set_comdat_group (NULL);
1719 if (target->get_comdat_group ())
1720 alias_alias->add_to_same_comdat_group (target);
1722 if (!alias_alias->transparent_alias || transparent)
1724 alias_alias->remove_all_references ();
1725 alias_alias->create_reference (target, IPA_REF_ALIAS, NULL);
1727 else i++;
1729 return true;
1732 /* Worker searching noninterposable alias. */
1734 bool
1735 symtab_node::noninterposable_alias (symtab_node *node, void *data)
1737 if (!node->transparent_alias && decl_binds_to_current_def_p (node->decl))
1739 symtab_node *fn = node->ultimate_alias_target ();
1741 /* Ensure that the alias is well formed this may not be the case
1742 of user defined aliases and currently it is not always the case
1743 of C++ same body aliases (that is a bug). */
1744 if (TREE_TYPE (node->decl) != TREE_TYPE (fn->decl)
1745 || DECL_CONTEXT (node->decl) != DECL_CONTEXT (fn->decl)
1746 || (TREE_CODE (node->decl) == FUNCTION_DECL
1747 && flags_from_decl_or_type (node->decl)
1748 != flags_from_decl_or_type (fn->decl))
1749 || DECL_ATTRIBUTES (node->decl) != DECL_ATTRIBUTES (fn->decl))
1750 return false;
1751 *(symtab_node **)data = node;
1752 return true;
1754 return false;
1757 /* If node can not be overwriten by static or dynamic linker to point to
1758 different definition, return NODE. Otherwise look for alias with such
1759 property and if none exists, introduce new one. */
1761 symtab_node *
1762 symtab_node::noninterposable_alias (void)
1764 tree new_decl;
1765 symtab_node *new_node = NULL;
1767 /* First try to look up existing alias or base object
1768 (if that is already non-overwritable). */
1769 symtab_node *node = ultimate_alias_target ();
1770 gcc_assert (!node->alias && !node->weakref);
1771 node->call_for_symbol_and_aliases (symtab_node::noninterposable_alias,
1772 (void *)&new_node, true);
1773 if (new_node)
1774 return new_node;
1776 /* If aliases aren't supported by the assembler, fail. */
1777 if (!TARGET_SUPPORTS_ALIASES)
1778 return NULL;
1780 /* Otherwise create a new one. */
1781 new_decl = copy_node (node->decl);
1782 DECL_DLLIMPORT_P (new_decl) = 0;
1783 DECL_NAME (new_decl) = clone_function_name (node->decl, "localalias");
1784 if (TREE_CODE (new_decl) == FUNCTION_DECL)
1785 DECL_STRUCT_FUNCTION (new_decl) = NULL;
1786 DECL_INITIAL (new_decl) = NULL;
1787 SET_DECL_ASSEMBLER_NAME (new_decl, DECL_NAME (new_decl));
1788 SET_DECL_RTL (new_decl, NULL);
1790 /* Update the properties. */
1791 DECL_EXTERNAL (new_decl) = 0;
1792 TREE_PUBLIC (new_decl) = 0;
1793 DECL_COMDAT (new_decl) = 0;
1794 DECL_WEAK (new_decl) = 0;
1796 /* Since the aliases can be added to vtables, keep DECL_VIRTUAL flag. */
1797 DECL_VIRTUAL_P (new_decl) = DECL_VIRTUAL_P (node->decl);
1798 if (TREE_CODE (new_decl) == FUNCTION_DECL)
1800 DECL_STATIC_CONSTRUCTOR (new_decl) = 0;
1801 DECL_STATIC_DESTRUCTOR (new_decl) = 0;
1802 new_node = cgraph_node::create_alias (new_decl, node->decl);
1804 else
1806 TREE_READONLY (new_decl) = TREE_READONLY (node->decl);
1807 DECL_INITIAL (new_decl) = error_mark_node;
1808 new_node = varpool_node::create_alias (new_decl, node->decl);
1810 new_node->resolve_alias (node);
1811 gcc_assert (decl_binds_to_current_def_p (new_decl)
1812 && targetm.binds_local_p (new_decl));
1813 return new_node;
1816 /* Return true if symtab node and TARGET represents
1817 semantically equivalent symbols. */
1819 bool
1820 symtab_node::semantically_equivalent_p (symtab_node *target)
1822 enum availability avail;
1823 symtab_node *ba;
1824 symtab_node *bb;
1826 /* Equivalent functions are equivalent. */
1827 if (decl == target->decl)
1828 return true;
1830 /* If symbol is not overwritable by different implementation,
1831 walk to the base object it defines. */
1832 ba = ultimate_alias_target (&avail);
1833 if (avail >= AVAIL_AVAILABLE)
1835 if (target == ba)
1836 return true;
1838 else
1839 ba = this;
1840 bb = target->ultimate_alias_target (&avail);
1841 if (avail >= AVAIL_AVAILABLE)
1843 if (this == bb)
1844 return true;
1846 else
1847 bb = target;
1848 return bb == ba;
1851 /* Classify symbol symtab node for partitioning. */
1853 enum symbol_partitioning_class
1854 symtab_node::get_partitioning_class (void)
1856 /* Inline clones are always duplicated.
1857 This include external delcarations. */
1858 cgraph_node *cnode = dyn_cast <cgraph_node *> (this);
1860 if (DECL_ABSTRACT_P (decl))
1861 return SYMBOL_EXTERNAL;
1863 if (cnode && cnode->global.inlined_to)
1864 return SYMBOL_DUPLICATE;
1866 /* Transparent aliases are always duplicated. */
1867 if (transparent_alias)
1868 return definition ? SYMBOL_DUPLICATE : SYMBOL_EXTERNAL;
1870 /* External declarations are external. */
1871 if (DECL_EXTERNAL (decl))
1872 return SYMBOL_EXTERNAL;
1874 if (varpool_node *vnode = dyn_cast <varpool_node *> (this))
1876 if (alias && definition && !ultimate_alias_target ()->definition)
1877 return SYMBOL_EXTERNAL;
1878 /* Constant pool references use local symbol names that can not
1879 be promoted global. We should never put into a constant pool
1880 objects that can not be duplicated across partitions. */
1881 if (DECL_IN_CONSTANT_POOL (decl))
1882 return SYMBOL_DUPLICATE;
1883 if (DECL_HARD_REGISTER (decl))
1884 return SYMBOL_DUPLICATE;
1885 gcc_checking_assert (vnode->definition);
1887 /* Functions that are cloned may stay in callgraph even if they are unused.
1888 Handle them as external; compute_ltrans_boundary take care to make
1889 proper things to happen (i.e. to make them appear in the boundary but
1890 with body streamed, so clone can me materialized). */
1891 else if (!dyn_cast <cgraph_node *> (this)->function_symbol ()->definition)
1892 return SYMBOL_EXTERNAL;
1894 /* Linker discardable symbols are duplicated to every use unless they are
1895 keyed. */
1896 if (DECL_ONE_ONLY (decl)
1897 && !force_output
1898 && !forced_by_abi
1899 && !used_from_object_file_p ())
1900 return SYMBOL_DUPLICATE;
1902 return SYMBOL_PARTITION;
1905 /* Return true when symbol is known to be non-zero. */
1907 bool
1908 symtab_node::nonzero_address ()
1910 /* Weakrefs may be NULL when their target is not defined. */
1911 if (alias && weakref)
1913 if (analyzed)
1915 symtab_node *target = ultimate_alias_target ();
1917 if (target->alias && target->weakref)
1918 return false;
1919 /* We can not recurse to target::nonzero. It is possible that the
1920 target is used only via the alias.
1921 We may walk references and look for strong use, but we do not know
1922 if this strong use will survive to final binary, so be
1923 conservative here.
1924 ??? Maybe we could do the lookup during late optimization that
1925 could be useful to eliminate the NULL pointer checks in LTO
1926 programs. */
1927 if (target->definition && !DECL_EXTERNAL (target->decl))
1928 return true;
1929 if (target->resolution != LDPR_UNKNOWN
1930 && target->resolution != LDPR_UNDEF
1931 && !target->can_be_discarded_p ()
1932 && flag_delete_null_pointer_checks)
1933 return true;
1934 return false;
1936 else
1937 return false;
1940 /* With !flag_delete_null_pointer_checks we assume that symbols may
1941 bind to NULL. This is on by default on embedded targets only.
1943 Otherwise all non-WEAK symbols must be defined and thus non-NULL or
1944 linking fails. Important case of WEAK we want to do well are comdats.
1945 Those are handled by later check for definition.
1947 When parsing, beware the cases when WEAK attribute is added later. */
1948 if (!DECL_WEAK (decl)
1949 && flag_delete_null_pointer_checks)
1951 refuse_visibility_changes = true;
1952 return true;
1955 /* If target is defined and not extern, we know it will be output and thus
1956 it will bind to non-NULL.
1957 Play safe for flag_delete_null_pointer_checks where weak definition maye
1958 be re-defined by NULL. */
1959 if (definition && !DECL_EXTERNAL (decl)
1960 && (flag_delete_null_pointer_checks || !DECL_WEAK (decl)))
1962 if (!DECL_WEAK (decl))
1963 refuse_visibility_changes = true;
1964 return true;
1967 /* As the last resort, check the resolution info. */
1968 if (resolution != LDPR_UNKNOWN
1969 && resolution != LDPR_UNDEF
1970 && !can_be_discarded_p ()
1971 && flag_delete_null_pointer_checks)
1972 return true;
1973 return false;
1976 /* Return 0 if symbol is known to have different address than S2,
1977 Return 1 if symbol is known to have same address as S2,
1978 return -1 otherwise.
1980 If MEMORY_ACCESSED is true, assume that both memory pointer to THIS
1981 and S2 is going to be accessed. This eliminates the situations when
1982 either THIS or S2 is NULL and is seful for comparing bases when deciding
1983 about memory aliasing. */
1985 symtab_node::equal_address_to (symtab_node *s2, bool memory_accessed)
1987 enum availability avail1, avail2;
1989 /* A Shortcut: equivalent symbols are always equivalent. */
1990 if (this == s2)
1991 return 1;
1993 /* Unwind transparent aliases first; those are always equal to their
1994 target. */
1995 if (this->transparent_alias && this->analyzed)
1996 return this->get_alias_target ()->equal_address_to (s2);
1997 while (s2->transparent_alias && s2->analyzed)
1998 s2 = s2->get_alias_target();
2000 if (this == s2)
2001 return 1;
2003 /* For non-interposable aliases, lookup and compare their actual definitions.
2004 Also check if the symbol needs to bind to given definition. */
2005 symtab_node *rs1 = ultimate_alias_target (&avail1);
2006 symtab_node *rs2 = s2->ultimate_alias_target (&avail2);
2007 bool binds_local1 = rs1->analyzed && decl_binds_to_current_def_p (this->decl);
2008 bool binds_local2 = rs2->analyzed && decl_binds_to_current_def_p (s2->decl);
2009 bool really_binds_local1 = binds_local1;
2010 bool really_binds_local2 = binds_local2;
2012 /* Addresses of vtables and virtual functions can not be used by user
2013 code and are used only within speculation. In this case we may make
2014 symbol equivalent to its alias even if interposition may break this
2015 rule. Doing so will allow us to turn speculative inlining into
2016 non-speculative more agressively. */
2017 if (DECL_VIRTUAL_P (this->decl) && avail1 >= AVAIL_AVAILABLE)
2018 binds_local1 = true;
2019 if (DECL_VIRTUAL_P (s2->decl) && avail2 >= AVAIL_AVAILABLE)
2020 binds_local2 = true;
2022 /* If both definitions are available we know that even if they are bound
2023 to other unit they must be defined same way and therefore we can use
2024 equivalence test. */
2025 if (rs1 != rs2 && avail1 >= AVAIL_AVAILABLE && avail2 >= AVAIL_AVAILABLE)
2026 binds_local1 = binds_local2 = true;
2028 if (binds_local1 && binds_local2 && rs1 == rs2)
2030 /* We made use of the fact that alias is not weak. */
2031 if (rs1 != this)
2032 refuse_visibility_changes = true;
2033 if (rs2 != s2)
2034 s2->refuse_visibility_changes = true;
2035 return 1;
2038 /* If both symbols may resolve to NULL, we can not really prove them
2039 different. */
2040 if (!memory_accessed && !nonzero_address () && !s2->nonzero_address ())
2041 return -1;
2043 /* Except for NULL, functions and variables never overlap. */
2044 if (TREE_CODE (decl) != TREE_CODE (s2->decl))
2045 return 0;
2047 /* If one of the symbols is unresolved alias, punt. */
2048 if (rs1->alias || rs2->alias)
2049 return -1;
2051 /* If we have a non-interposale definition of at least one of the symbols
2052 and the other symbol is different, we know other unit can not interpose
2053 it to the first symbol; all aliases of the definition needs to be
2054 present in the current unit. */
2055 if (((really_binds_local1 || really_binds_local2)
2056 /* If we have both definitions and they are different, we know they
2057 will be different even in units they binds to. */
2058 || (binds_local1 && binds_local2))
2059 && rs1 != rs2)
2061 /* We make use of the fact that one symbol is not alias of the other
2062 and that the definition is non-interposable. */
2063 refuse_visibility_changes = true;
2064 s2->refuse_visibility_changes = true;
2065 rs1->refuse_visibility_changes = true;
2066 rs2->refuse_visibility_changes = true;
2067 return 0;
2070 /* TODO: Alias oracle basically assume that addresses of global variables
2071 are different unless they are declared as alias of one to another while
2072 the code folding comparsions doesn't.
2073 We probably should be consistent and use this fact here, too, but for
2074 the moment return false only when we are called from the alias oracle. */
2076 return memory_accessed && rs1 != rs2 ? 0 : -1;
2079 /* Worker for call_for_symbol_and_aliases. */
2081 bool
2082 symtab_node::call_for_symbol_and_aliases_1 (bool (*callback) (symtab_node *,
2083 void *),
2084 void *data,
2085 bool include_overwritable)
2087 ipa_ref *ref;
2088 FOR_EACH_ALIAS (this, ref)
2090 symtab_node *alias = ref->referring;
2091 if (include_overwritable
2092 || alias->get_availability () > AVAIL_INTERPOSABLE)
2093 if (alias->call_for_symbol_and_aliases (callback, data,
2094 include_overwritable))
2095 return true;
2097 return false;
2100 /* Return true if address of N is possibly compared. */
2102 static bool
2103 address_matters_1 (symtab_node *n, void *)
2105 struct ipa_ref *ref;
2107 if (!n->address_can_be_compared_p ())
2108 return false;
2109 if (n->externally_visible || n->force_output)
2110 return true;
2112 for (unsigned int i = 0; n->iterate_referring (i, ref); i++)
2113 if (ref->address_matters_p ())
2114 return true;
2115 return false;
2118 /* Return true if symbol's address may possibly be compared to other
2119 symbol's address. */
2121 bool
2122 symtab_node::address_matters_p ()
2124 gcc_assert (!alias);
2125 return call_for_symbol_and_aliases (address_matters_1, NULL, true);
2128 /* Return true if symbol's alignment may be increased. */
2130 bool
2131 symtab_node::can_increase_alignment_p (void)
2133 symtab_node *target = ultimate_alias_target ();
2135 /* For now support only variables. */
2136 if (!VAR_P (decl))
2137 return false;
2139 /* With -fno-toplevel-reorder we may have already output the constant. */
2140 if (TREE_ASM_WRITTEN (target->decl))
2141 return false;
2143 /* If target is already placed in an anchor, we can not touch its
2144 alignment. */
2145 if (DECL_RTL_SET_P (target->decl)
2146 && MEM_P (DECL_RTL (target->decl))
2147 && SYMBOL_REF_HAS_BLOCK_INFO_P (XEXP (DECL_RTL (target->decl), 0)))
2148 return false;
2150 /* Constant pool entries may be shared. */
2151 if (DECL_IN_CONSTANT_POOL (target->decl))
2152 return false;
2154 /* We cannot change alignment of symbols that may bind to symbols
2155 in other translation unit that may contain a definition with lower
2156 alignment. */
2157 if (!decl_binds_to_current_def_p (decl))
2158 return false;
2160 /* When compiling partition, be sure the symbol is not output by other
2161 partition. */
2162 if (flag_ltrans
2163 && (target->in_other_partition
2164 || target->get_partitioning_class () == SYMBOL_DUPLICATE))
2165 return false;
2167 /* Do not override the alignment as specified by the ABI when the used
2168 attribute is set. */
2169 if (DECL_PRESERVE_P (decl) || DECL_PRESERVE_P (target->decl))
2170 return false;
2172 /* Do not override explicit alignment set by the user when an explicit
2173 section name is also used. This is a common idiom used by many
2174 software projects. */
2175 if (DECL_SECTION_NAME (target->decl) != NULL && !target->implicit_section)
2176 return false;
2178 return true;
2181 /* Worker for symtab_node::increase_alignment. */
2183 static bool
2184 increase_alignment_1 (symtab_node *n, void *v)
2186 unsigned int align = (size_t)v;
2187 if (DECL_ALIGN (n->decl) < align
2188 && n->can_increase_alignment_p ())
2190 SET_DECL_ALIGN (n->decl, align);
2191 DECL_USER_ALIGN (n->decl) = 1;
2193 return false;
2196 /* Increase alignment of THIS to ALIGN. */
2198 void
2199 symtab_node::increase_alignment (unsigned int align)
2201 gcc_assert (can_increase_alignment_p () && align < MAX_OFILE_ALIGNMENT);
2202 ultimate_alias_target()->call_for_symbol_and_aliases (increase_alignment_1,
2203 (void *)(size_t) align,
2204 true);
2205 gcc_assert (DECL_ALIGN (decl) >= align);
2208 /* Helper for symtab_node::definition_alignment. */
2210 static bool
2211 get_alignment_1 (symtab_node *n, void *v)
2213 *((unsigned int *)v) = MAX (*((unsigned int *)v), DECL_ALIGN (n->decl));
2214 return false;
2217 /* Return desired alignment of the definition. This is NOT alignment useful
2218 to access THIS, because THIS may be interposable and DECL_ALIGN should
2219 be used instead. It however must be guaranteed when output definition
2220 of THIS. */
2222 unsigned int
2223 symtab_node::definition_alignment ()
2225 unsigned int align = 0;
2226 gcc_assert (!alias);
2227 call_for_symbol_and_aliases (get_alignment_1, &align, true);
2228 return align;
2231 /* Return symbol used to separate symbol name from suffix. */
2233 char
2234 symbol_table::symbol_suffix_separator ()
2236 #ifndef NO_DOT_IN_LABEL
2237 return '.';
2238 #elif !defined NO_DOLLAR_IN_LABEL
2239 return '$';
2240 #else
2241 return '_';
2242 #endif
2245 /* Return true when references to this symbol from REF must bind to current
2246 definition in final executable. */
2248 bool
2249 symtab_node::binds_to_current_def_p (symtab_node *ref)
2251 if (!definition)
2252 return false;
2253 if (transparent_alias)
2254 return definition
2255 && get_alias_target()->binds_to_current_def_p (ref);
2256 if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
2257 return false;
2258 if (decl_binds_to_current_def_p (decl))
2259 return true;
2261 /* Inline clones always binds locally. */
2262 cgraph_node *cnode = dyn_cast <cgraph_node *> (this);
2263 if (cnode && cnode->global.inlined_to)
2264 return true;
2266 if (DECL_EXTERNAL (decl))
2267 return false;
2269 gcc_assert (externally_visible);
2271 if (ref)
2273 cgraph_node *cref = dyn_cast <cgraph_node *> (ref);
2274 if (cref)
2275 ref = cref->global.inlined_to;
2278 /* If this is a reference from symbol itself and there are no aliases, we
2279 may be sure that the symbol was not interposed by something else because
2280 the symbol itself would be unreachable otherwise. This is important
2281 to optimize recursive functions well.
2283 This assumption may be broken by inlining: if symbol is interposable
2284 but the body is available (i.e. declared inline), inliner may make
2285 the body reachable even with interposition. */
2286 if (this == ref && !has_aliases_p ()
2287 && (!cnode
2288 || symtab->state >= IPA_SSA_AFTER_INLINING
2289 || get_availability () >= AVAIL_INTERPOSABLE))
2290 return true;
2293 /* References within one comdat group are always bound in a group. */
2294 if (ref
2295 && symtab->state >= IPA_SSA_AFTER_INLINING
2296 && get_comdat_group ()
2297 && get_comdat_group () == ref->get_comdat_group ())
2298 return true;
2300 return false;
2303 /* Return true if symbol should be output to the symbol table. */
2305 bool
2306 symtab_node::output_to_lto_symbol_table_p (void)
2308 /* Only externally visible symbols matter. */
2309 if (!TREE_PUBLIC (decl))
2310 return false;
2311 if (!real_symbol_p ())
2312 return false;
2313 /* FIXME: variables probably should not be considered as real symbols at
2314 first place. */
2315 if (VAR_P (decl) && DECL_HARD_REGISTER (decl))
2316 return false;
2317 /* FIXME: Builtins corresponding to real functions probably should have
2318 symbol table entries. */
2319 if (is_builtin_fn (decl))
2320 return false;
2322 /* We have real symbol that should be in symbol table. However try to trim
2323 down the refernces to libraries bit more because linker will otherwise
2324 bring unnecesary object files into the final link.
2325 FIXME: The following checks can easily be confused i.e. by self recursive
2326 function or self-referring variable. */
2328 /* We keep external functions in symtab for sake of inlining
2329 and devirtualization. We do not want to see them in symbol table as
2330 references unless they are really used. */
2331 cgraph_node *cnode = dyn_cast <cgraph_node *> (this);
2332 if (cnode && (!definition || DECL_EXTERNAL (decl))
2333 && cnode->callers)
2334 return true;
2336 /* Ignore all references from external vars initializers - they are not really
2337 part of the compilation unit until they are used by folding. Some symbols,
2338 like references to external construction vtables can not be referred to at
2339 all. We decide this at can_refer_decl_in_current_unit_p. */
2340 if (!definition || DECL_EXTERNAL (decl))
2342 int i;
2343 struct ipa_ref *ref;
2344 for (i = 0; iterate_referring (i, ref); i++)
2346 if (ref->use == IPA_REF_ALIAS)
2347 continue;
2348 if (is_a <cgraph_node *> (ref->referring))
2349 return true;
2350 if (!DECL_EXTERNAL (ref->referring->decl))
2351 return true;
2353 return false;
2355 return true;