1 /* Block-related functions for the GNU debugger, GDB.
3 Copyright (C) 2003-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "gdb_obstack.h"
25 #include "cp-support.h"
30 /* This is used by struct block to store namespace-related info for
31 C++ files, namely using declarations and the current namespace in
34 struct block_namespace_info : public allocate_on_obstack
36 const char *scope = nullptr;
37 struct using_direct *using_decl = nullptr;
40 static void block_initialize_namespace (struct block *block,
41 struct obstack *obstack);
46 block_objfile (const struct block *block)
48 const struct global_block *global_block;
50 if (BLOCK_FUNCTION (block) != NULL)
51 return symbol_objfile (BLOCK_FUNCTION (block));
53 global_block = (struct global_block *) block_global_block (block);
54 return COMPUNIT_OBJFILE (global_block->compunit_symtab);
60 block_gdbarch (const struct block *block)
62 if (BLOCK_FUNCTION (block) != NULL)
63 return symbol_arch (BLOCK_FUNCTION (block));
65 return get_objfile_arch (block_objfile (block));
71 contained_in (const struct block *a, const struct block *b,
81 /* If A is a function block, then A cannot be contained in B,
82 except if A was inlined. */
83 if (!allow_nested && BLOCK_FUNCTION (a) != NULL && !block_inlined_p (a))
85 a = BLOCK_SUPERBLOCK (a);
93 /* Return the symbol for the function which contains a specified
94 lexical block, described by a struct block BL. The return value
95 will not be an inlined function; the containing function will be
99 block_linkage_function (const struct block *bl)
101 while ((BLOCK_FUNCTION (bl) == NULL || block_inlined_p (bl))
102 && BLOCK_SUPERBLOCK (bl) != NULL)
103 bl = BLOCK_SUPERBLOCK (bl);
105 return BLOCK_FUNCTION (bl);
108 /* Return the symbol for the function which contains a specified
109 block, described by a struct block BL. The return value will be
110 the closest enclosing function, which might be an inline
114 block_containing_function (const struct block *bl)
116 while (BLOCK_FUNCTION (bl) == NULL && BLOCK_SUPERBLOCK (bl) != NULL)
117 bl = BLOCK_SUPERBLOCK (bl);
119 return BLOCK_FUNCTION (bl);
122 /* Return one if BL represents an inlined function. */
125 block_inlined_p (const struct block *bl)
127 return BLOCK_FUNCTION (bl) != NULL && SYMBOL_INLINED (BLOCK_FUNCTION (bl));
130 /* A helper function that checks whether PC is in the blockvector BL.
131 It returns the containing block if there is one, or else NULL. */
133 static const struct block *
134 find_block_in_blockvector (const struct blockvector *bl, CORE_ADDR pc)
136 const struct block *b;
139 /* If we have an addrmap mapping code addresses to blocks, then use
141 if (BLOCKVECTOR_MAP (bl))
142 return (const struct block *) addrmap_find (BLOCKVECTOR_MAP (bl), pc);
144 /* Otherwise, use binary search to find the last block that starts
146 Note: GLOBAL_BLOCK is block 0, STATIC_BLOCK is block 1.
147 They both have the same START,END values.
148 Historically this code would choose STATIC_BLOCK over GLOBAL_BLOCK but the
149 fact that this choice was made was subtle, now we make it explicit. */
150 gdb_assert (BLOCKVECTOR_NBLOCKS (bl) >= 2);
152 top = BLOCKVECTOR_NBLOCKS (bl);
154 while (top - bot > 1)
156 half = (top - bot + 1) >> 1;
157 b = BLOCKVECTOR_BLOCK (bl, bot + half);
158 if (BLOCK_START (b) <= pc)
164 /* Now search backward for a block that ends after PC. */
166 while (bot >= STATIC_BLOCK)
168 b = BLOCKVECTOR_BLOCK (bl, bot);
169 if (BLOCK_END (b) > pc)
177 /* Return the blockvector immediately containing the innermost lexical
178 block containing the specified pc value and section, or 0 if there
179 is none. PBLOCK is a pointer to the block. If PBLOCK is NULL, we
180 don't pass this information back to the caller. */
182 const struct blockvector *
183 blockvector_for_pc_sect (CORE_ADDR pc, struct obj_section *section,
184 const struct block **pblock,
185 struct compunit_symtab *cust)
187 const struct blockvector *bl;
188 const struct block *b;
192 /* First search all symtabs for one whose file contains our pc */
193 cust = find_pc_sect_compunit_symtab (pc, section);
198 bl = COMPUNIT_BLOCKVECTOR (cust);
200 /* Then search that symtab for the smallest block that wins. */
201 b = find_block_in_blockvector (bl, pc);
210 /* Return true if the blockvector BV contains PC, false otherwise. */
213 blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc)
215 return find_block_in_blockvector (bv, pc) != NULL;
218 /* Return call_site for specified PC in GDBARCH. PC must match exactly, it
219 must be the next instruction after call (or after tail call jump). Throw
220 NO_ENTRY_VALUE_ERROR otherwise. This function never returns NULL. */
223 call_site_for_pc (struct gdbarch *gdbarch, CORE_ADDR pc)
225 struct compunit_symtab *cust;
228 /* -1 as tail call PC can be already after the compilation unit range. */
229 cust = find_pc_compunit_symtab (pc - 1);
231 if (cust != NULL && COMPUNIT_CALL_SITE_HTAB (cust) != NULL)
232 slot = htab_find_slot (COMPUNIT_CALL_SITE_HTAB (cust), &pc, NO_INSERT);
236 struct bound_minimal_symbol msym = lookup_minimal_symbol_by_pc (pc);
238 /* DW_TAG_gnu_call_site will be missing just if GCC could not determine
240 throw_error (NO_ENTRY_VALUE_ERROR,
241 _("DW_OP_entry_value resolving cannot find "
242 "DW_TAG_call_site %s in %s"),
243 paddress (gdbarch, pc),
244 (msym.minsym == NULL ? "???"
245 : MSYMBOL_PRINT_NAME (msym.minsym)));
248 return (struct call_site *) *slot;
251 /* Return the blockvector immediately containing the innermost lexical block
252 containing the specified pc value, or 0 if there is none.
253 Backward compatibility, no section. */
255 const struct blockvector *
256 blockvector_for_pc (CORE_ADDR pc, const struct block **pblock)
258 return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
262 /* Return the innermost lexical block containing the specified pc value
263 in the specified section, or 0 if there is none. */
266 block_for_pc_sect (CORE_ADDR pc, struct obj_section *section)
268 const struct blockvector *bl;
269 const struct block *b;
271 bl = blockvector_for_pc_sect (pc, section, &b, NULL);
277 /* Return the innermost lexical block containing the specified pc value,
278 or 0 if there is none. Backward compatibility, no section. */
281 block_for_pc (CORE_ADDR pc)
283 return block_for_pc_sect (pc, find_pc_mapped_section (pc));
286 /* Now come some functions designed to deal with C++ namespace issues.
287 The accessors are safe to use even in the non-C++ case. */
289 /* This returns the namespace that BLOCK is enclosed in, or "" if it
290 isn't enclosed in a namespace at all. This travels the chain of
291 superblocks looking for a scope, if necessary. */
294 block_scope (const struct block *block)
296 for (; block != NULL; block = BLOCK_SUPERBLOCK (block))
298 if (BLOCK_NAMESPACE (block) != NULL
299 && BLOCK_NAMESPACE (block)->scope != NULL)
300 return BLOCK_NAMESPACE (block)->scope;
306 /* Set BLOCK's scope member to SCOPE; if needed, allocate memory via
307 OBSTACK. (It won't make a copy of SCOPE, however, so that already
308 has to be allocated correctly.) */
311 block_set_scope (struct block *block, const char *scope,
312 struct obstack *obstack)
314 block_initialize_namespace (block, obstack);
316 BLOCK_NAMESPACE (block)->scope = scope;
319 /* This returns the using directives list associated with BLOCK, if
322 struct using_direct *
323 block_using (const struct block *block)
325 if (block == NULL || BLOCK_NAMESPACE (block) == NULL)
328 return BLOCK_NAMESPACE (block)->using_decl;
331 /* Set BLOCK's using member to USING; if needed, allocate memory via
332 OBSTACK. (It won't make a copy of USING, however, so that already
333 has to be allocated correctly.) */
336 block_set_using (struct block *block,
337 struct using_direct *using_decl,
338 struct obstack *obstack)
340 block_initialize_namespace (block, obstack);
342 BLOCK_NAMESPACE (block)->using_decl = using_decl;
345 /* If BLOCK_NAMESPACE (block) is NULL, allocate it via OBSTACK and
346 ititialize its members to zero. */
349 block_initialize_namespace (struct block *block, struct obstack *obstack)
351 if (BLOCK_NAMESPACE (block) == NULL)
352 BLOCK_NAMESPACE (block) = new (obstack) struct block_namespace_info ();
355 /* Return the static block associated to BLOCK. Return NULL if block
356 is NULL or if block is a global block. */
359 block_static_block (const struct block *block)
361 if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL)
364 while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL)
365 block = BLOCK_SUPERBLOCK (block);
370 /* Return the static block associated to BLOCK. Return NULL if block
374 block_global_block (const struct block *block)
379 while (BLOCK_SUPERBLOCK (block) != NULL)
380 block = BLOCK_SUPERBLOCK (block);
385 /* Allocate a block on OBSTACK, and initialize its elements to
386 zero/NULL. This is useful for creating "dummy" blocks that don't
387 correspond to actual source files.
389 Warning: it sets the block's BLOCK_MULTIDICT to NULL, which isn't a
390 valid value. If you really don't want the block to have a
391 dictionary, then you should subsequently set its BLOCK_MULTIDICT to
392 dict_create_linear (obstack, NULL). */
395 allocate_block (struct obstack *obstack)
397 struct block *bl = OBSTACK_ZALLOC (obstack, struct block);
402 /* Allocate a global block. */
405 allocate_global_block (struct obstack *obstack)
407 struct global_block *bl = OBSTACK_ZALLOC (obstack, struct global_block);
412 /* Set the compunit of the global block. */
415 set_block_compunit_symtab (struct block *block, struct compunit_symtab *cu)
417 struct global_block *gb;
419 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
420 gb = (struct global_block *) block;
421 gdb_assert (gb->compunit_symtab == NULL);
422 gb->compunit_symtab = cu;
427 struct dynamic_prop *
428 block_static_link (const struct block *block)
430 struct objfile *objfile = block_objfile (block);
432 /* Only objfile-owned blocks that materialize top function scopes can have
434 if (objfile == NULL || BLOCK_FUNCTION (block) == NULL)
437 return (struct dynamic_prop *) objfile_lookup_static_link (objfile, block);
440 /* Return the compunit of the global block. */
442 static struct compunit_symtab *
443 get_block_compunit_symtab (const struct block *block)
445 struct global_block *gb;
447 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
448 gb = (struct global_block *) block;
449 gdb_assert (gb->compunit_symtab != NULL);
450 return gb->compunit_symtab;
455 /* Initialize a block iterator, either to iterate over a single block,
456 or, for static and global blocks, all the included symtabs as
460 initialize_block_iterator (const struct block *block,
461 struct block_iterator *iter)
463 enum block_enum which;
464 struct compunit_symtab *cu;
468 if (BLOCK_SUPERBLOCK (block) == NULL)
470 which = GLOBAL_BLOCK;
471 cu = get_block_compunit_symtab (block);
473 else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL)
475 which = STATIC_BLOCK;
476 cu = get_block_compunit_symtab (BLOCK_SUPERBLOCK (block));
480 iter->d.block = block;
481 /* A signal value meaning that we're iterating over a single
483 iter->which = FIRST_LOCAL_BLOCK;
487 /* If this is an included symtab, find the canonical includer and
489 while (cu->user != NULL)
492 /* Putting this check here simplifies the logic of the iterator
493 functions. If there are no included symtabs, we only need to
494 search a single block, so we might as well just do that
496 if (cu->includes == NULL)
498 iter->d.block = block;
499 /* A signal value meaning that we're iterating over a single
501 iter->which = FIRST_LOCAL_BLOCK;
505 iter->d.compunit_symtab = cu;
510 /* A helper function that finds the current compunit over whose static
511 or global block we should iterate. */
513 static struct compunit_symtab *
514 find_iterator_compunit_symtab (struct block_iterator *iterator)
516 if (iterator->idx == -1)
517 return iterator->d.compunit_symtab;
518 return iterator->d.compunit_symtab->includes[iterator->idx];
521 /* Perform a single step for a plain block iterator, iterating across
522 symbol tables as needed. Returns the next symbol, or NULL when
523 iteration is complete. */
525 static struct symbol *
526 block_iterator_step (struct block_iterator *iterator, int first)
530 gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
536 struct compunit_symtab *cust
537 = find_iterator_compunit_symtab (iterator);
538 const struct block *block;
540 /* Iteration is complete. */
544 block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
546 sym = mdict_iterator_first (BLOCK_MULTIDICT (block),
547 &iterator->mdict_iter);
550 sym = mdict_iterator_next (&iterator->mdict_iter);
555 /* We have finished iterating the appropriate block of one
556 symtab. Now advance to the next symtab and begin iteration
566 block_iterator_first (const struct block *block,
567 struct block_iterator *iterator)
569 initialize_block_iterator (block, iterator);
571 if (iterator->which == FIRST_LOCAL_BLOCK)
572 return mdict_iterator_first (block->multidict, &iterator->mdict_iter);
574 return block_iterator_step (iterator, 1);
580 block_iterator_next (struct block_iterator *iterator)
582 if (iterator->which == FIRST_LOCAL_BLOCK)
583 return mdict_iterator_next (&iterator->mdict_iter);
585 return block_iterator_step (iterator, 0);
588 /* Perform a single step for a "match" block iterator, iterating
589 across symbol tables as needed. Returns the next symbol, or NULL
590 when iteration is complete. */
592 static struct symbol *
593 block_iter_match_step (struct block_iterator *iterator,
594 const lookup_name_info &name,
599 gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
605 struct compunit_symtab *cust
606 = find_iterator_compunit_symtab (iterator);
607 const struct block *block;
609 /* Iteration is complete. */
613 block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
615 sym = mdict_iter_match_first (BLOCK_MULTIDICT (block), name,
616 &iterator->mdict_iter);
619 sym = mdict_iter_match_next (name, &iterator->mdict_iter);
624 /* We have finished iterating the appropriate block of one
625 symtab. Now advance to the next symtab and begin iteration
635 block_iter_match_first (const struct block *block,
636 const lookup_name_info &name,
637 struct block_iterator *iterator)
639 initialize_block_iterator (block, iterator);
641 if (iterator->which == FIRST_LOCAL_BLOCK)
642 return mdict_iter_match_first (block->multidict, name,
643 &iterator->mdict_iter);
645 return block_iter_match_step (iterator, name, 1);
651 block_iter_match_next (const lookup_name_info &name,
652 struct block_iterator *iterator)
654 if (iterator->which == FIRST_LOCAL_BLOCK)
655 return mdict_iter_match_next (name, &iterator->mdict_iter);
657 return block_iter_match_step (iterator, name, 0);
662 Note that if NAME is the demangled form of a C++ symbol, we will fail
663 to find a match during the binary search of the non-encoded names, but
664 for now we don't worry about the slight inefficiency of looking for
665 a match we'll never find, since it will go pretty quick. Once the
666 binary search terminates, we drop through and do a straight linear
667 search on the symbols. Each symbol which is marked as being a ObjC/C++
668 symbol (language_cplus or language_objc set) has both the encoded and
669 non-encoded names tested for a match. */
672 block_lookup_symbol (const struct block *block, const char *name,
673 symbol_name_match_type match_type,
674 const domain_enum domain)
676 struct block_iterator iter;
679 lookup_name_info lookup_name (name, match_type);
681 if (!BLOCK_FUNCTION (block))
683 struct symbol *other = NULL;
685 ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
687 if (SYMBOL_DOMAIN (sym) == domain)
689 /* This is a bit of a hack, but symbol_matches_domain might ignore
690 STRUCT vs VAR domain symbols. So if a matching symbol is found,
691 make sure there is no "better" matching symbol, i.e., one with
692 exactly the same domain. PR 16253. */
693 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
694 SYMBOL_DOMAIN (sym), domain))
701 /* Note that parameter symbols do not always show up last in the
702 list; this loop makes sure to take anything else other than
703 parameter symbols first; it only uses parameter symbols as a
704 last resort. Note that this only takes up extra computation
706 It's hard to define types in the parameter list (at least in
707 C/C++) so we don't do the same PR 16253 hack here that is done
708 for the !BLOCK_FUNCTION case. */
710 struct symbol *sym_found = NULL;
712 ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
714 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
715 SYMBOL_DOMAIN (sym), domain))
718 if (!SYMBOL_IS_ARGUMENT (sym))
724 return (sym_found); /* Will be NULL if not found. */
731 block_lookup_symbol_primary (const struct block *block, const char *name,
732 const domain_enum domain)
734 struct symbol *sym, *other;
735 struct mdict_iterator mdict_iter;
737 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
739 /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK. */
740 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
741 || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
745 = mdict_iter_match_first (block->multidict, lookup_name, &mdict_iter);
747 sym = mdict_iter_match_next (lookup_name, &mdict_iter))
749 if (SYMBOL_DOMAIN (sym) == domain)
752 /* This is a bit of a hack, but symbol_matches_domain might ignore
753 STRUCT vs VAR domain symbols. So if a matching symbol is found,
754 make sure there is no "better" matching symbol, i.e., one with
755 exactly the same domain. PR 16253. */
756 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
757 SYMBOL_DOMAIN (sym), domain))
767 block_find_symbol (const struct block *block, const char *name,
768 const domain_enum domain,
769 block_symbol_matcher_ftype *matcher, void *data)
771 struct block_iterator iter;
774 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
776 /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK. */
777 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
778 || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
780 ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
782 /* MATCHER is deliberately called second here so that it never sees
783 a non-domain-matching symbol. */
784 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
785 SYMBOL_DOMAIN (sym), domain)
786 && matcher (sym, data))
795 block_find_non_opaque_type (struct symbol *sym, void *data)
797 return !TYPE_IS_OPAQUE (SYMBOL_TYPE (sym));
803 block_find_non_opaque_type_preferred (struct symbol *sym, void *data)
805 struct symbol **best = (struct symbol **) data;
807 if (!TYPE_IS_OPAQUE (SYMBOL_TYPE (sym)))
816 make_blockranges (struct objfile *objfile,
817 const std::vector<blockrange> &rangevec)
819 struct blockranges *blr;
820 size_t n = rangevec.size();
822 blr = (struct blockranges *)
823 obstack_alloc (&objfile->objfile_obstack,
824 sizeof (struct blockranges)
825 + (n - 1) * sizeof (struct blockrange));
828 for (int i = 0; i < n; i++)
829 blr->range[i] = rangevec[i];