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));
68 /* Return Nonzero if block a is lexically nested within block b,
69 or if a and b have the same pc range.
70 Return zero otherwise. */
73 contained_in (const struct block *a, const struct block *b)
82 a = BLOCK_SUPERBLOCK (a);
90 /* Return the symbol for the function which contains a specified
91 lexical block, described by a struct block BL. The return value
92 will not be an inlined function; the containing function will be
96 block_linkage_function (const struct block *bl)
98 while ((BLOCK_FUNCTION (bl) == NULL || block_inlined_p (bl))
99 && BLOCK_SUPERBLOCK (bl) != NULL)
100 bl = BLOCK_SUPERBLOCK (bl);
102 return BLOCK_FUNCTION (bl);
105 /* Return the symbol for the function which contains a specified
106 block, described by a struct block BL. The return value will be
107 the closest enclosing function, which might be an inline
111 block_containing_function (const struct block *bl)
113 while (BLOCK_FUNCTION (bl) == NULL && BLOCK_SUPERBLOCK (bl) != NULL)
114 bl = BLOCK_SUPERBLOCK (bl);
116 return BLOCK_FUNCTION (bl);
119 /* Return one if BL represents an inlined function. */
122 block_inlined_p (const struct block *bl)
124 return BLOCK_FUNCTION (bl) != NULL && SYMBOL_INLINED (BLOCK_FUNCTION (bl));
127 /* A helper function that checks whether PC is in the blockvector BL.
128 It returns the containing block if there is one, or else NULL. */
130 static const struct block *
131 find_block_in_blockvector (const struct blockvector *bl, CORE_ADDR pc)
133 const struct block *b;
136 /* If we have an addrmap mapping code addresses to blocks, then use
138 if (BLOCKVECTOR_MAP (bl))
139 return (const struct block *) addrmap_find (BLOCKVECTOR_MAP (bl), pc);
141 /* Otherwise, use binary search to find the last block that starts
143 Note: GLOBAL_BLOCK is block 0, STATIC_BLOCK is block 1.
144 They both have the same START,END values.
145 Historically this code would choose STATIC_BLOCK over GLOBAL_BLOCK but the
146 fact that this choice was made was subtle, now we make it explicit. */
147 gdb_assert (BLOCKVECTOR_NBLOCKS (bl) >= 2);
149 top = BLOCKVECTOR_NBLOCKS (bl);
151 while (top - bot > 1)
153 half = (top - bot + 1) >> 1;
154 b = BLOCKVECTOR_BLOCK (bl, bot + half);
155 if (BLOCK_START (b) <= pc)
161 /* Now search backward for a block that ends after PC. */
163 while (bot >= STATIC_BLOCK)
165 b = BLOCKVECTOR_BLOCK (bl, bot);
166 if (BLOCK_END (b) > pc)
174 /* Return the blockvector immediately containing the innermost lexical
175 block containing the specified pc value and section, or 0 if there
176 is none. PBLOCK is a pointer to the block. If PBLOCK is NULL, we
177 don't pass this information back to the caller. */
179 const struct blockvector *
180 blockvector_for_pc_sect (CORE_ADDR pc, struct obj_section *section,
181 const struct block **pblock,
182 struct compunit_symtab *cust)
184 const struct blockvector *bl;
185 const struct block *b;
189 /* First search all symtabs for one whose file contains our pc */
190 cust = find_pc_sect_compunit_symtab (pc, section);
195 bl = COMPUNIT_BLOCKVECTOR (cust);
197 /* Then search that symtab for the smallest block that wins. */
198 b = find_block_in_blockvector (bl, pc);
207 /* Return true if the blockvector BV contains PC, false otherwise. */
210 blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc)
212 return find_block_in_blockvector (bv, pc) != NULL;
215 /* Return call_site for specified PC in GDBARCH. PC must match exactly, it
216 must be the next instruction after call (or after tail call jump). Throw
217 NO_ENTRY_VALUE_ERROR otherwise. This function never returns NULL. */
220 call_site_for_pc (struct gdbarch *gdbarch, CORE_ADDR pc)
222 struct compunit_symtab *cust;
225 /* -1 as tail call PC can be already after the compilation unit range. */
226 cust = find_pc_compunit_symtab (pc - 1);
228 if (cust != NULL && COMPUNIT_CALL_SITE_HTAB (cust) != NULL)
229 slot = htab_find_slot (COMPUNIT_CALL_SITE_HTAB (cust), &pc, NO_INSERT);
233 struct bound_minimal_symbol msym = lookup_minimal_symbol_by_pc (pc);
235 /* DW_TAG_gnu_call_site will be missing just if GCC could not determine
237 throw_error (NO_ENTRY_VALUE_ERROR,
238 _("DW_OP_entry_value resolving cannot find "
239 "DW_TAG_call_site %s in %s"),
240 paddress (gdbarch, pc),
241 (msym.minsym == NULL ? "???"
242 : MSYMBOL_PRINT_NAME (msym.minsym)));
245 return (struct call_site *) *slot;
248 /* Return the blockvector immediately containing the innermost lexical block
249 containing the specified pc value, or 0 if there is none.
250 Backward compatibility, no section. */
252 const struct blockvector *
253 blockvector_for_pc (CORE_ADDR pc, const struct block **pblock)
255 return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
259 /* Return the innermost lexical block containing the specified pc value
260 in the specified section, or 0 if there is none. */
263 block_for_pc_sect (CORE_ADDR pc, struct obj_section *section)
265 const struct blockvector *bl;
266 const struct block *b;
268 bl = blockvector_for_pc_sect (pc, section, &b, NULL);
274 /* Return the innermost lexical block containing the specified pc value,
275 or 0 if there is none. Backward compatibility, no section. */
278 block_for_pc (CORE_ADDR pc)
280 return block_for_pc_sect (pc, find_pc_mapped_section (pc));
283 /* Now come some functions designed to deal with C++ namespace issues.
284 The accessors are safe to use even in the non-C++ case. */
286 /* This returns the namespace that BLOCK is enclosed in, or "" if it
287 isn't enclosed in a namespace at all. This travels the chain of
288 superblocks looking for a scope, if necessary. */
291 block_scope (const struct block *block)
293 for (; block != NULL; block = BLOCK_SUPERBLOCK (block))
295 if (BLOCK_NAMESPACE (block) != NULL
296 && BLOCK_NAMESPACE (block)->scope != NULL)
297 return BLOCK_NAMESPACE (block)->scope;
303 /* Set BLOCK's scope member to SCOPE; if needed, allocate memory via
304 OBSTACK. (It won't make a copy of SCOPE, however, so that already
305 has to be allocated correctly.) */
308 block_set_scope (struct block *block, const char *scope,
309 struct obstack *obstack)
311 block_initialize_namespace (block, obstack);
313 BLOCK_NAMESPACE (block)->scope = scope;
316 /* This returns the using directives list associated with BLOCK, if
319 struct using_direct *
320 block_using (const struct block *block)
322 if (block == NULL || BLOCK_NAMESPACE (block) == NULL)
325 return BLOCK_NAMESPACE (block)->using_decl;
328 /* Set BLOCK's using member to USING; if needed, allocate memory via
329 OBSTACK. (It won't make a copy of USING, however, so that already
330 has to be allocated correctly.) */
333 block_set_using (struct block *block,
334 struct using_direct *using_decl,
335 struct obstack *obstack)
337 block_initialize_namespace (block, obstack);
339 BLOCK_NAMESPACE (block)->using_decl = using_decl;
342 /* If BLOCK_NAMESPACE (block) is NULL, allocate it via OBSTACK and
343 ititialize its members to zero. */
346 block_initialize_namespace (struct block *block, struct obstack *obstack)
348 if (BLOCK_NAMESPACE (block) == NULL)
349 BLOCK_NAMESPACE (block) = new (obstack) struct block_namespace_info ();
352 /* Return the static block associated to BLOCK. Return NULL if block
353 is NULL or if block is a global block. */
356 block_static_block (const struct block *block)
358 if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL)
361 while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL)
362 block = BLOCK_SUPERBLOCK (block);
367 /* Return the static block associated to BLOCK. Return NULL if block
371 block_global_block (const struct block *block)
376 while (BLOCK_SUPERBLOCK (block) != NULL)
377 block = BLOCK_SUPERBLOCK (block);
382 /* Allocate a block on OBSTACK, and initialize its elements to
383 zero/NULL. This is useful for creating "dummy" blocks that don't
384 correspond to actual source files.
386 Warning: it sets the block's BLOCK_MULTIDICT to NULL, which isn't a
387 valid value. If you really don't want the block to have a
388 dictionary, then you should subsequently set its BLOCK_MULTIDICT to
389 dict_create_linear (obstack, NULL). */
392 allocate_block (struct obstack *obstack)
394 struct block *bl = OBSTACK_ZALLOC (obstack, struct block);
399 /* Allocate a global block. */
402 allocate_global_block (struct obstack *obstack)
404 struct global_block *bl = OBSTACK_ZALLOC (obstack, struct global_block);
409 /* Set the compunit of the global block. */
412 set_block_compunit_symtab (struct block *block, struct compunit_symtab *cu)
414 struct global_block *gb;
416 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
417 gb = (struct global_block *) block;
418 gdb_assert (gb->compunit_symtab == NULL);
419 gb->compunit_symtab = cu;
424 struct dynamic_prop *
425 block_static_link (const struct block *block)
427 struct objfile *objfile = block_objfile (block);
429 /* Only objfile-owned blocks that materialize top function scopes can have
431 if (objfile == NULL || BLOCK_FUNCTION (block) == NULL)
434 return (struct dynamic_prop *) objfile_lookup_static_link (objfile, block);
437 /* Return the compunit of the global block. */
439 static struct compunit_symtab *
440 get_block_compunit_symtab (const struct block *block)
442 struct global_block *gb;
444 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
445 gb = (struct global_block *) block;
446 gdb_assert (gb->compunit_symtab != NULL);
447 return gb->compunit_symtab;
452 /* Initialize a block iterator, either to iterate over a single block,
453 or, for static and global blocks, all the included symtabs as
457 initialize_block_iterator (const struct block *block,
458 struct block_iterator *iter)
460 enum block_enum which;
461 struct compunit_symtab *cu;
465 if (BLOCK_SUPERBLOCK (block) == NULL)
467 which = GLOBAL_BLOCK;
468 cu = get_block_compunit_symtab (block);
470 else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL)
472 which = STATIC_BLOCK;
473 cu = get_block_compunit_symtab (BLOCK_SUPERBLOCK (block));
477 iter->d.block = block;
478 /* A signal value meaning that we're iterating over a single
480 iter->which = FIRST_LOCAL_BLOCK;
484 /* If this is an included symtab, find the canonical includer and
486 while (cu->user != NULL)
489 /* Putting this check here simplifies the logic of the iterator
490 functions. If there are no included symtabs, we only need to
491 search a single block, so we might as well just do that
493 if (cu->includes == NULL)
495 iter->d.block = block;
496 /* A signal value meaning that we're iterating over a single
498 iter->which = FIRST_LOCAL_BLOCK;
502 iter->d.compunit_symtab = cu;
507 /* A helper function that finds the current compunit over whose static
508 or global block we should iterate. */
510 static struct compunit_symtab *
511 find_iterator_compunit_symtab (struct block_iterator *iterator)
513 if (iterator->idx == -1)
514 return iterator->d.compunit_symtab;
515 return iterator->d.compunit_symtab->includes[iterator->idx];
518 /* Perform a single step for a plain block iterator, iterating across
519 symbol tables as needed. Returns the next symbol, or NULL when
520 iteration is complete. */
522 static struct symbol *
523 block_iterator_step (struct block_iterator *iterator, int first)
527 gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
533 struct compunit_symtab *cust
534 = find_iterator_compunit_symtab (iterator);
535 const struct block *block;
537 /* Iteration is complete. */
541 block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
543 sym = mdict_iterator_first (BLOCK_MULTIDICT (block),
544 &iterator->mdict_iter);
547 sym = mdict_iterator_next (&iterator->mdict_iter);
552 /* We have finished iterating the appropriate block of one
553 symtab. Now advance to the next symtab and begin iteration
563 block_iterator_first (const struct block *block,
564 struct block_iterator *iterator)
566 initialize_block_iterator (block, iterator);
568 if (iterator->which == FIRST_LOCAL_BLOCK)
569 return mdict_iterator_first (block->multidict, &iterator->mdict_iter);
571 return block_iterator_step (iterator, 1);
577 block_iterator_next (struct block_iterator *iterator)
579 if (iterator->which == FIRST_LOCAL_BLOCK)
580 return mdict_iterator_next (&iterator->mdict_iter);
582 return block_iterator_step (iterator, 0);
585 /* Perform a single step for a "match" block iterator, iterating
586 across symbol tables as needed. Returns the next symbol, or NULL
587 when iteration is complete. */
589 static struct symbol *
590 block_iter_match_step (struct block_iterator *iterator,
591 const lookup_name_info &name,
596 gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
602 struct compunit_symtab *cust
603 = find_iterator_compunit_symtab (iterator);
604 const struct block *block;
606 /* Iteration is complete. */
610 block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
612 sym = mdict_iter_match_first (BLOCK_MULTIDICT (block), name,
613 &iterator->mdict_iter);
616 sym = mdict_iter_match_next (name, &iterator->mdict_iter);
621 /* We have finished iterating the appropriate block of one
622 symtab. Now advance to the next symtab and begin iteration
632 block_iter_match_first (const struct block *block,
633 const lookup_name_info &name,
634 struct block_iterator *iterator)
636 initialize_block_iterator (block, iterator);
638 if (iterator->which == FIRST_LOCAL_BLOCK)
639 return mdict_iter_match_first (block->multidict, name,
640 &iterator->mdict_iter);
642 return block_iter_match_step (iterator, name, 1);
648 block_iter_match_next (const lookup_name_info &name,
649 struct block_iterator *iterator)
651 if (iterator->which == FIRST_LOCAL_BLOCK)
652 return mdict_iter_match_next (name, &iterator->mdict_iter);
654 return block_iter_match_step (iterator, name, 0);
659 Note that if NAME is the demangled form of a C++ symbol, we will fail
660 to find a match during the binary search of the non-encoded names, but
661 for now we don't worry about the slight inefficiency of looking for
662 a match we'll never find, since it will go pretty quick. Once the
663 binary search terminates, we drop through and do a straight linear
664 search on the symbols. Each symbol which is marked as being a ObjC/C++
665 symbol (language_cplus or language_objc set) has both the encoded and
666 non-encoded names tested for a match. */
669 block_lookup_symbol (const struct block *block, const char *name,
670 symbol_name_match_type match_type,
671 const domain_enum domain)
673 struct block_iterator iter;
676 lookup_name_info lookup_name (name, match_type);
678 if (!BLOCK_FUNCTION (block))
680 struct symbol *other = NULL;
682 ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
684 if (SYMBOL_DOMAIN (sym) == domain)
686 /* This is a bit of a hack, but symbol_matches_domain might ignore
687 STRUCT vs VAR domain symbols. So if a matching symbol is found,
688 make sure there is no "better" matching symbol, i.e., one with
689 exactly the same domain. PR 16253. */
690 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
691 SYMBOL_DOMAIN (sym), domain))
698 /* Note that parameter symbols do not always show up last in the
699 list; this loop makes sure to take anything else other than
700 parameter symbols first; it only uses parameter symbols as a
701 last resort. Note that this only takes up extra computation
703 It's hard to define types in the parameter list (at least in
704 C/C++) so we don't do the same PR 16253 hack here that is done
705 for the !BLOCK_FUNCTION case. */
707 struct symbol *sym_found = NULL;
709 ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
711 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
712 SYMBOL_DOMAIN (sym), domain))
715 if (!SYMBOL_IS_ARGUMENT (sym))
721 return (sym_found); /* Will be NULL if not found. */
728 block_lookup_symbol_primary (const struct block *block, const char *name,
729 const domain_enum domain)
731 struct symbol *sym, *other;
732 struct mdict_iterator mdict_iter;
734 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
736 /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK. */
737 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
738 || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
742 = mdict_iter_match_first (block->multidict, lookup_name, &mdict_iter);
744 sym = mdict_iter_match_next (lookup_name, &mdict_iter))
746 if (SYMBOL_DOMAIN (sym) == domain)
749 /* This is a bit of a hack, but symbol_matches_domain might ignore
750 STRUCT vs VAR domain symbols. So if a matching symbol is found,
751 make sure there is no "better" matching symbol, i.e., one with
752 exactly the same domain. PR 16253. */
753 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
754 SYMBOL_DOMAIN (sym), domain))
764 block_find_symbol (const struct block *block, const char *name,
765 const domain_enum domain,
766 block_symbol_matcher_ftype *matcher, void *data)
768 struct block_iterator iter;
771 lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
773 /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK. */
774 gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
775 || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
777 ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym)
779 /* MATCHER is deliberately called second here so that it never sees
780 a non-domain-matching symbol. */
781 if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
782 SYMBOL_DOMAIN (sym), domain)
783 && matcher (sym, data))
792 block_find_non_opaque_type (struct symbol *sym, void *data)
794 return !TYPE_IS_OPAQUE (SYMBOL_TYPE (sym));
800 block_find_non_opaque_type_preferred (struct symbol *sym, void *data)
802 struct symbol **best = (struct symbol **) data;
804 if (!TYPE_IS_OPAQUE (SYMBOL_TYPE (sym)))
813 make_blockranges (struct objfile *objfile,
814 const std::vector<blockrange> &rangevec)
816 struct blockranges *blr;
817 size_t n = rangevec.size();
819 blr = (struct blockranges *)
820 obstack_alloc (&objfile->objfile_obstack,
821 sizeof (struct blockranges)
822 + (n - 1) * sizeof (struct blockrange));
825 for (int i = 0; i < n; i++)
826 blr->range[i] = rangevec[i];