1 /* Helper routines for C++ support in GDB.
2 Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
5 Contributed by David Carlton and by Kealia, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "cp-support.h"
24 #include "gdb_obstack.h"
27 #include "gdb_assert.h"
31 #include "dictionary.h"
36 static struct symbol *lookup_namespace_scope (const char *name,
37 const char *linkage_name,
38 const struct block *block,
39 const domain_enum domain,
43 static struct symbol *lookup_symbol_file (const char *name,
44 const char *linkage_name,
45 const struct block *block,
46 const domain_enum domain,
47 int anonymous_namespace);
49 static struct type *cp_lookup_transparent_type_loop (const char *name,
53 static void initialize_namespace_symtab (struct objfile *objfile);
55 static struct block *get_possible_namespace_block (struct objfile *objfile);
57 static void free_namespace_block (struct symtab *symtab);
59 static int check_possible_namespace_symbols_loop (const char *name,
61 struct objfile *objfile);
63 static int check_one_possible_namespace_symbol (const char *name,
65 struct objfile *objfile);
67 static struct symbol *lookup_possible_namespace_symbol (const char *name);
69 static void maintenance_cplus_namespace (char *args, int from_tty);
71 /* Check to see if SYMBOL refers to an object contained within an
72 anonymous namespace; if so, add an appropriate using directive. */
74 /* Optimize away strlen ("(anonymous namespace)"). */
76 #define ANONYMOUS_NAMESPACE_LEN 21
79 cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
81 if (SYMBOL_DEMANGLED_NAME (symbol) != NULL)
83 const char *name = SYMBOL_DEMANGLED_NAME (symbol);
84 unsigned int previous_component;
85 unsigned int next_component;
88 /* Start with a quick-and-dirty check for mention of "(anonymous
91 if (!cp_is_anonymous (name))
94 previous_component = 0;
95 next_component = cp_find_first_component (name + previous_component);
97 while (name[next_component] == ':')
99 if ((next_component - previous_component) == ANONYMOUS_NAMESPACE_LEN
100 && strncmp (name + previous_component,
101 "(anonymous namespace)",
102 ANONYMOUS_NAMESPACE_LEN) == 0)
104 int dest_len = (previous_component == 0 ? 0 : previous_component - 2);
105 int src_len = next_component;
107 char *dest = alloca (dest_len + 1);
108 char *src = alloca (src_len + 1);
110 memcpy (dest, name, dest_len);
111 memcpy (src, name, src_len);
113 dest[dest_len] = '\0';
116 /* We've found a component of the name that's an
117 anonymous namespace. So add symbols in it to the
118 namespace given by the previous component if there is
119 one, or to the global namespace if there isn't. */
120 cp_add_using_directive (dest, src);
122 /* The "+ 2" is for the "::". */
123 previous_component = next_component + 2;
124 next_component = (previous_component
125 + cp_find_first_component (name
126 + previous_component));
131 /* Add a using directive to using_list. If the using directive in question
132 has already been added, don't add it twice. */
135 cp_add_using_directive (const char *dest, const char *src)
137 struct using_direct *current;
138 struct using_direct *new;
140 /* Has it already been added? */
142 for (current = using_directives; current != NULL; current = current->next)
144 if (strcmp (current->import_src, src) == 0
145 && strcmp (current->import_dest, dest) == 0)
149 using_directives = cp_add_using (dest, src, using_directives);
153 /* Record the namespace that the function defined by SYMBOL was
154 defined in, if necessary. BLOCK is the associated block; use
155 OBSTACK for allocation. */
158 cp_set_block_scope (const struct symbol *symbol,
160 struct obstack *obstack,
161 const char *processing_current_prefix,
162 int processing_has_namespace_info)
164 if (processing_has_namespace_info)
167 (block, obsavestring (processing_current_prefix,
168 strlen (processing_current_prefix),
172 else if (SYMBOL_DEMANGLED_NAME (symbol) != NULL)
174 /* Try to figure out the appropriate namespace from the
177 /* FIXME: carlton/2003-04-15: If the function in question is
178 a method of a class, the name will actually include the
179 name of the class as well. This should be harmless, but
180 is a little unfortunate. */
182 const char *name = SYMBOL_DEMANGLED_NAME (symbol);
183 unsigned int prefix_len = cp_entire_prefix_len (name);
185 block_set_scope (block,
186 obsavestring (name, prefix_len, obstack),
191 /* Test whether or not NAMESPACE looks like it mentions an anonymous
192 namespace; return nonzero if so. */
195 cp_is_anonymous (const char *namespace)
197 return (strstr (namespace, "(anonymous namespace)")
201 /* Create a new struct using direct which imports the namespace SRC
203 Set its next member in the linked list to NEXT; allocate all memory
204 using xmalloc. It copies the strings, so NAME can be a temporary
207 struct using_direct *
208 cp_add_using (const char *dest,
210 struct using_direct *next)
212 struct using_direct *retval;
214 retval = xmalloc (sizeof (struct using_direct));
215 retval->import_src = savestring (src, strlen(src));
216 retval->import_dest = savestring (dest, strlen(dest));
218 retval->searched = 0;
223 /* The C++-specific version of name lookup for static and global
224 names. This makes sure that names get looked for in all namespaces
225 that are in scope. NAME is the natural name of the symbol that
226 we're looking for, LINKAGE_NAME (which is optional) is its linkage
227 name, BLOCK is the block that we're searching within, DOMAIN says
228 what kind of symbols we're looking for, and if SYMTAB is non-NULL,
229 we should store the symtab where we found the symbol in it. */
232 cp_lookup_symbol_nonlocal (const char *name,
233 const char *linkage_name,
234 const struct block *block,
235 const domain_enum domain)
238 const char *scope = block_scope (block);
240 sym = lookup_namespace_scope (name, linkage_name, block, domain, scope, 0);
244 return cp_lookup_symbol_namespace (scope, name, linkage_name, block, domain,
248 /* Look up NAME in the C++ namespace NAMESPACE. Other arguments are as in
249 cp_lookup_symbol_nonlocal. */
251 static struct symbol *
252 cp_lookup_symbol_in_namespace (const char *namespace,
254 const char *linkage_name,
255 const struct block *block,
256 const domain_enum domain)
258 if (namespace[0] == '\0')
260 return lookup_symbol_file (name, linkage_name, block,
265 char *concatenated_name = alloca (strlen (namespace) + 2 +
267 strcpy (concatenated_name, namespace);
268 strcat (concatenated_name, "::");
269 strcat (concatenated_name, name);
270 return lookup_symbol_file (concatenated_name, linkage_name,
271 block, domain,cp_is_anonymous (namespace));
275 /* Used for cleanups to reset the "searched" flag incase
279 reset_directive_searched (void *data)
281 struct using_direct *direct = data;
282 direct->searched = 0;
285 /* Search for NAME by applying all import statements belonging
286 to BLOCK which are applicable in SCOPE.
287 If SEARCH_PARENTS the search will include imports which are applicable in
298 If SCOPE is "A::B" and SEARCH_PARENTS is true the imports of namespaces X
299 and Y will be considered. If SEARCH_PARENTS is false only the import of Y
302 static struct symbol *
303 cp_lookup_symbol_imports (const char *scope,
305 const char *linkage_name,
306 const struct block *block,
307 const domain_enum domain,
308 const int search_parents)
310 struct using_direct *current;
314 struct cleanup *searched_cleanup;
316 /* First, try to find the symbol in the given namespace. */
317 sym = cp_lookup_symbol_in_namespace (scope, name, linkage_name, block,
322 /* Go through the using directives. If any of them add new
323 names to the namespace we're searching in, see if we can find a
324 match by applying them. */
326 for (current = block_using (block);
328 current = current->next)
330 len = strlen (current->import_dest);
331 directive_match = (search_parents
332 ? (strncmp (scope, current->import_dest,
333 strlen (current->import_dest)) == 0
335 || scope[len] == ':' || scope[len] == '\0'))
336 : strcmp (scope, current->import_dest) == 0);
338 /* If the import destination is the current scope or one of its ancestors then
340 if (directive_match && !current->searched)
342 /* Mark this import as searched so that the recursive call does not
344 current->searched = 1;
345 searched_cleanup = make_cleanup (reset_directive_searched, current);
347 sym = cp_lookup_symbol_namespace (current->import_src,
354 current->searched = 0;
355 discard_cleanups (searched_cleanup);
365 /* Searches for NAME in the current namespace, and by applying relevant import
366 statements belonging to BLOCK and its parents. SCOPE is the namespace scope
367 of the context in which the search is being evaluated. */
370 cp_lookup_symbol_namespace (const char *scope,
372 const char *linkage_name,
373 const struct block *block,
374 const domain_enum domain,
375 const int search_parents)
379 /* Search for name in namespaces imported to this and parent blocks. */
380 while (block != NULL)
382 sym = cp_lookup_symbol_imports (scope, name, linkage_name, block, domain,
388 block = BLOCK_SUPERBLOCK (block);
394 /* Lookup NAME at namespace scope (or, in C terms, in static and
395 global variables). SCOPE is the namespace that the current
396 function is defined within; only consider namespaces whose length
397 is at least SCOPE_LEN. Other arguments are as in
398 cp_lookup_symbol_nonlocal.
400 For example, if we're within a function A::B::f and looking for a
401 symbol x, this will get called with NAME = "x", SCOPE = "A::B", and
402 SCOPE_LEN = 0. It then calls itself with NAME and SCOPE the same,
403 but with SCOPE_LEN = 1. And then it calls itself with NAME and
404 SCOPE the same, but with SCOPE_LEN = 4. This third call looks for
405 "A::B::x"; if it doesn't find it, then the second call looks for
406 "A::x", and if that call fails, then the first call looks for
409 static struct symbol *
410 lookup_namespace_scope (const char *name,
411 const char *linkage_name,
412 const struct block *block,
413 const domain_enum domain,
419 if (scope[scope_len] != '\0')
421 /* Recursively search for names in child namespaces first. */
424 int new_scope_len = scope_len;
426 /* If the current scope is followed by "::", skip past that. */
427 if (new_scope_len != 0)
429 gdb_assert (scope[new_scope_len] == ':');
432 new_scope_len += cp_find_first_component (scope + new_scope_len);
433 sym = lookup_namespace_scope (name, linkage_name, block,
434 domain, scope, new_scope_len);
439 /* Okay, we didn't find a match in our children, so look for the
440 name in the current namespace. */
442 namespace = alloca (scope_len + 1);
443 strncpy (namespace, scope, scope_len);
444 namespace[scope_len] = '\0';
445 return cp_lookup_symbol_in_namespace (namespace, name, linkage_name,
449 /* Look up NAME in BLOCK's static block and in global blocks. If
450 ANONYMOUS_NAMESPACE is nonzero, the symbol in question is located
451 within an anonymous namespace. Other arguments are as in
452 cp_lookup_symbol_nonlocal. */
454 static struct symbol *
455 lookup_symbol_file (const char *name,
456 const char *linkage_name,
457 const struct block *block,
458 const domain_enum domain,
459 int anonymous_namespace)
461 struct symbol *sym = NULL;
463 sym = lookup_symbol_static (name, linkage_name, block, domain);
467 if (anonymous_namespace)
469 /* Symbols defined in anonymous namespaces have external linkage
470 but should be treated as local to a single file nonetheless.
471 So we only search the current file's global block. */
473 const struct block *global_block = block_global_block (block);
475 if (global_block != NULL)
476 sym = lookup_symbol_aux_block (name, linkage_name, global_block,
481 sym = lookup_symbol_global (name, linkage_name, block, domain);
487 /* Now call "lookup_possible_namespace_symbol". Symbols in here
488 claim to be associated to namespaces, but this claim might be
489 incorrect: the names in question might actually correspond to
490 classes instead of namespaces. But if they correspond to
491 classes, then we should have found a match for them above. So if
492 we find them now, they should be genuine. */
494 /* FIXME: carlton/2003-06-12: This is a hack and should eventually
495 be deleted: see comments below. */
497 if (domain == VAR_DOMAIN)
499 sym = lookup_possible_namespace_symbol (name);
507 /* Look up a type named NESTED_NAME that is nested inside the C++
508 class or namespace given by PARENT_TYPE, from within the context
509 given by BLOCK. Return NULL if there is no such nested type. */
512 cp_lookup_nested_type (struct type *parent_type,
513 const char *nested_name,
514 const struct block *block)
516 switch (TYPE_CODE (parent_type))
518 case TYPE_CODE_STRUCT:
519 case TYPE_CODE_NAMESPACE:
521 /* NOTE: carlton/2003-11-10: We don't treat C++ class members
522 of classes like, say, data or function members. Instead,
523 they're just represented by symbols whose names are
524 qualified by the name of the surrounding class. This is
525 just like members of namespaces; in particular,
526 lookup_symbol_namespace works when looking them up. */
528 const char *parent_name = TYPE_TAG_NAME (parent_type);
529 struct symbol *sym = cp_lookup_symbol_in_namespace (parent_name,
534 if (sym == NULL || SYMBOL_CLASS (sym) != LOC_TYPEDEF)
537 return SYMBOL_TYPE (sym);
540 internal_error (__FILE__, __LINE__,
541 _("cp_lookup_nested_type called on a non-aggregate type."));
545 /* The C++-version of lookup_transparent_type. */
547 /* FIXME: carlton/2004-01-16: The problem that this is trying to
548 address is that, unfortunately, sometimes NAME is wrong: it may not
549 include the name of namespaces enclosing the type in question.
550 lookup_transparent_type gets called when the the type in question
551 is a declaration, and we're trying to find its definition; but, for
552 declarations, our type name deduction mechanism doesn't work.
553 There's nothing we can do to fix this in general, I think, in the
554 absence of debug information about namespaces (I've filed PR
555 gdb/1511 about this); until such debug information becomes more
556 prevalent, one heuristic which sometimes looks is to search for the
557 definition in namespaces containing the current namespace.
559 We should delete this functions once the appropriate debug
560 information becomes more widespread. (GCC 3.4 will be the first
561 released version of GCC with such information.) */
564 cp_lookup_transparent_type (const char *name)
566 /* First, try the honest way of looking up the definition. */
567 struct type *t = basic_lookup_transparent_type (name);
573 /* If that doesn't work and we're within a namespace, look there
575 scope = block_scope (get_selected_block (0));
577 if (scope[0] == '\0')
580 return cp_lookup_transparent_type_loop (name, scope, 0);
583 /* Lookup the the type definition associated to NAME in
584 namespaces/classes containing SCOPE whose name is strictly longer
585 than LENGTH. LENGTH must be the index of the start of a
586 component of SCOPE. */
589 cp_lookup_transparent_type_loop (const char *name, const char *scope,
592 int scope_length = length + cp_find_first_component (scope + length);
595 /* If the current scope is followed by "::", look in the next
597 if (scope[scope_length] == ':')
600 = cp_lookup_transparent_type_loop (name, scope, scope_length + 2);
605 full_name = alloca (scope_length + 2 + strlen (name) + 1);
606 strncpy (full_name, scope, scope_length);
607 strncpy (full_name + scope_length, "::", 2);
608 strcpy (full_name + scope_length + 2, name);
610 return basic_lookup_transparent_type (full_name);
613 /* Now come functions for dealing with symbols associated to
614 namespaces. (They're used to store the namespaces themselves, not
615 objects that live in the namespaces.) These symbols come in two
616 varieties: if we run into a DW_TAG_namespace DIE, then we know that
617 we have a namespace, so dwarf2read.c creates a symbol for it just
618 like normal. But, unfortunately, versions of GCC through at least
619 3.3 don't generate those DIE's. Our solution is to try to guess
620 their existence by looking at demangled names. This might cause us
621 to misidentify classes as namespaces, however. So we put those
622 symbols in a special block (one per objfile), and we only search
623 that block as a last resort. */
625 /* FIXME: carlton/2003-06-12: Once versions of GCC that generate
626 DW_TAG_namespace have been out for a year or two, we should get rid
627 of all of this "possible namespace" nonsense. */
629 /* Allocate everything necessary for the possible namespace block
630 associated to OBJFILE. */
633 initialize_namespace_symtab (struct objfile *objfile)
635 struct symtab *namespace_symtab;
636 struct blockvector *bv;
639 namespace_symtab = allocate_symtab ("<<C++-namespaces>>", objfile);
640 namespace_symtab->language = language_cplus;
641 namespace_symtab->free_code = free_nothing;
642 namespace_symtab->dirname = NULL;
644 bv = obstack_alloc (&objfile->objfile_obstack,
645 sizeof (struct blockvector)
646 + FIRST_LOCAL_BLOCK * sizeof (struct block *));
647 BLOCKVECTOR_NBLOCKS (bv) = FIRST_LOCAL_BLOCK + 1;
648 BLOCKVECTOR (namespace_symtab) = bv;
650 /* Allocate empty GLOBAL_BLOCK and STATIC_BLOCK. */
652 bl = allocate_block (&objfile->objfile_obstack);
653 BLOCK_DICT (bl) = dict_create_linear (&objfile->objfile_obstack,
655 BLOCKVECTOR_BLOCK (bv, GLOBAL_BLOCK) = bl;
656 bl = allocate_block (&objfile->objfile_obstack);
657 BLOCK_DICT (bl) = dict_create_linear (&objfile->objfile_obstack,
659 BLOCKVECTOR_BLOCK (bv, STATIC_BLOCK) = bl;
661 /* Allocate the possible namespace block; we put it where the first
662 local block will live, though I don't think there's any need to
663 pretend that it's actually a local block (e.g. by setting
664 BLOCK_SUPERBLOCK appropriately). We don't use the global or
665 static block because we don't want it searched during the normal
666 search of all global/static blocks in lookup_symbol: we only want
667 it used as a last resort. */
669 /* NOTE: carlton/2003-09-11: I considered not associating the fake
670 symbols to a block/symtab at all. But that would cause problems
671 with lookup_symbol's SYMTAB argument and with block_found, so
672 having a symtab/block for this purpose seems like the best
675 bl = allocate_block (&objfile->objfile_obstack);
676 BLOCK_DICT (bl) = dict_create_hashed_expandable ();
677 BLOCKVECTOR_BLOCK (bv, FIRST_LOCAL_BLOCK) = bl;
679 namespace_symtab->free_func = free_namespace_block;
681 objfile->cp_namespace_symtab = namespace_symtab;
684 /* Locate the possible namespace block associated to OBJFILE,
685 allocating it if necessary. */
687 static struct block *
688 get_possible_namespace_block (struct objfile *objfile)
690 if (objfile->cp_namespace_symtab == NULL)
691 initialize_namespace_symtab (objfile);
693 return BLOCKVECTOR_BLOCK (BLOCKVECTOR (objfile->cp_namespace_symtab),
697 /* Free the dictionary associated to the possible namespace block. */
700 free_namespace_block (struct symtab *symtab)
702 struct block *possible_namespace_block;
704 possible_namespace_block = BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab),
706 gdb_assert (possible_namespace_block != NULL);
707 dict_free (BLOCK_DICT (possible_namespace_block));
710 /* Ensure that there are symbols in the possible namespace block
711 associated to OBJFILE for all initial substrings of NAME that look
712 like namespaces or classes. NAME should end in a member variable:
713 it shouldn't consist solely of namespaces. */
716 cp_check_possible_namespace_symbols (const char *name, struct objfile *objfile)
718 check_possible_namespace_symbols_loop (name,
719 cp_find_first_component (name),
723 /* This is a helper loop for cp_check_possible_namespace_symbols; it
724 ensures that there are symbols in the possible namespace block
725 associated to OBJFILE for all namespaces that are initial
726 substrings of NAME of length at least LEN. It returns 1 if a
727 previous loop had already created the shortest such symbol and 0
730 This function assumes that if there is already a symbol associated
731 to a substring of NAME of a given length, then there are already
732 symbols associated to all substrings of NAME whose length is less
733 than that length. So if cp_check_possible_namespace_symbols has
734 been called once with argument "A::B::C::member", then that will
735 create symbols "A", "A::B", and "A::B::C". If it is then later
736 called with argument "A::B::D::member", then the new call will
737 generate a new symbol for "A::B::D", but once it sees that "A::B"
738 has already been created, it doesn't bother checking to see if "A"
739 has also been created. */
742 check_possible_namespace_symbols_loop (const char *name, int len,
743 struct objfile *objfile)
745 if (name[len] == ':')
748 int next_len = len + 2;
750 next_len += cp_find_first_component (name + next_len);
751 done = check_possible_namespace_symbols_loop (name, next_len,
755 done = check_one_possible_namespace_symbol (name, len, objfile);
763 /* Check to see if there's already a possible namespace symbol in
764 OBJFILE whose name is the initial substring of NAME of length LEN.
765 If not, create one and return 0; otherwise, return 1. */
768 check_one_possible_namespace_symbol (const char *name, int len,
769 struct objfile *objfile)
771 struct block *block = get_possible_namespace_block (objfile);
772 char *name_copy = alloca (len + 1);
775 memcpy (name_copy, name, len);
776 name_copy[len] = '\0';
777 sym = lookup_block_symbol (block, name_copy, NULL, VAR_DOMAIN);
783 type = init_type (TYPE_CODE_NAMESPACE, 0, 0, name_copy, objfile);
785 TYPE_TAG_NAME (type) = TYPE_NAME (type);
787 sym = obstack_alloc (&objfile->objfile_obstack, sizeof (struct symbol));
788 memset (sym, 0, sizeof (struct symbol));
789 SYMBOL_LANGUAGE (sym) = language_cplus;
790 /* Note that init_type copied the name to the objfile's
792 SYMBOL_SET_NAMES (sym, TYPE_NAME (type), len, 0, objfile);
793 SYMBOL_CLASS (sym) = LOC_TYPEDEF;
794 SYMBOL_TYPE (sym) = type;
795 SYMBOL_DOMAIN (sym) = VAR_DOMAIN;
797 dict_add_symbol (BLOCK_DICT (block), sym);
805 /* Look for a symbol named NAME in all the possible namespace blocks.
806 If one is found, return it. */
808 static struct symbol *
809 lookup_possible_namespace_symbol (const char *name)
811 struct objfile *objfile;
813 ALL_OBJFILES (objfile)
817 sym = lookup_block_symbol (get_possible_namespace_block (objfile),
818 name, NULL, VAR_DOMAIN);
827 /* Print out all the possible namespace symbols. */
830 maintenance_cplus_namespace (char *args, int from_tty)
832 struct objfile *objfile;
833 printf_unfiltered (_("Possible namespaces:\n"));
834 ALL_OBJFILES (objfile)
836 struct dict_iterator iter;
839 ALL_BLOCK_SYMBOLS (get_possible_namespace_block (objfile), iter, sym)
841 printf_unfiltered ("%s\n", SYMBOL_PRINT_NAME (sym));
846 /* Provide a prototype to silence -Wmissing-prototypes. */
847 extern initialize_file_ftype _initialize_cp_namespace;
850 _initialize_cp_namespace (void)
852 add_cmd ("namespace", class_maintenance, maintenance_cplus_namespace,
853 _("Print the list of possible C++ namespaces."),
854 &maint_cplus_cmd_list);