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 initialize 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
];