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 using_direct
*cp_copy_usings (struct using_direct
*using,
37 struct obstack
*obstack
);
39 static struct symbol
*lookup_namespace_scope (const char *name
,
40 const char *linkage_name
,
41 const struct block
*block
,
42 const domain_enum domain
,
46 static struct symbol
*lookup_symbol_file (const char *name
,
47 const char *linkage_name
,
48 const struct block
*block
,
49 const domain_enum domain
,
50 int anonymous_namespace
);
52 static struct type
*cp_lookup_transparent_type_loop (const char *name
,
56 static void initialize_namespace_symtab (struct objfile
*objfile
);
58 static struct block
*get_possible_namespace_block (struct objfile
*objfile
);
60 static void free_namespace_block (struct symtab
*symtab
);
62 static int check_possible_namespace_symbols_loop (const char *name
,
64 struct objfile
*objfile
);
66 static int check_one_possible_namespace_symbol (const char *name
,
68 struct objfile
*objfile
);
70 static struct symbol
*lookup_possible_namespace_symbol (const char *name
);
72 static void maintenance_cplus_namespace (char *args
, int from_tty
);
74 /* Check to see if SYMBOL refers to an object contained within an
75 anonymous namespace; if so, add an appropriate using directive. */
77 /* Optimize away strlen ("(anonymous namespace)"). */
79 #define ANONYMOUS_NAMESPACE_LEN 21
82 cp_scan_for_anonymous_namespaces (const struct symbol
*symbol
)
84 if (SYMBOL_DEMANGLED_NAME (symbol
) != NULL
)
86 const char *name
= SYMBOL_DEMANGLED_NAME (symbol
);
87 unsigned int previous_component
;
88 unsigned int next_component
;
91 /* Start with a quick-and-dirty check for mention of "(anonymous
94 if (!cp_is_anonymous (name
))
97 previous_component
= 0;
98 next_component
= cp_find_first_component (name
+ previous_component
);
100 while (name
[next_component
] == ':')
102 if ((next_component
- previous_component
) == ANONYMOUS_NAMESPACE_LEN
103 && strncmp (name
+ previous_component
,
104 "(anonymous namespace)",
105 ANONYMOUS_NAMESPACE_LEN
) == 0)
107 int dest_len
= (previous_component
== 0 ? 0 : previous_component
- 2);
108 int src_len
= next_component
;
110 char *dest
= alloca (dest_len
+ 1);
111 char *src
= alloca (src_len
+ 1);
113 memcpy (dest
, name
, dest_len
);
114 memcpy (src
, name
, src_len
);
116 dest
[dest_len
] = '\0';
119 /* We've found a component of the name that's an
120 anonymous namespace. So add symbols in it to the
121 namespace given by the previous component if there is
122 one, or to the global namespace if there isn't. */
123 cp_add_using_directive (dest
, src
);
125 /* The "+ 2" is for the "::". */
126 previous_component
= next_component
+ 2;
127 next_component
= (previous_component
128 + cp_find_first_component (name
129 + previous_component
));
134 /* Add a using directive to using_list. If the using directive in question
135 has already been added, don't add it twice. */
138 cp_add_using_directive (const char *dest
, const char *src
)
140 struct using_direct
*current
;
141 struct using_direct
*new;
143 /* Has it already been added? */
145 for (current
= using_directives
; current
!= NULL
; current
= current
->next
)
147 if (strcmp (current
->import_src
, src
) == 0
148 && strcmp (current
->import_dest
, dest
) == 0)
152 using_directives
= cp_add_using (dest
, src
, using_directives
);
156 /* Record the namespace that the function defined by SYMBOL was
157 defined in, if necessary. BLOCK is the associated block; use
158 OBSTACK for allocation. */
161 cp_set_block_scope (const struct symbol
*symbol
,
163 struct obstack
*obstack
,
164 const char *processing_current_prefix
,
165 int processing_has_namespace_info
)
167 if (processing_has_namespace_info
)
170 (block
, obsavestring (processing_current_prefix
,
171 strlen (processing_current_prefix
),
175 else if (SYMBOL_DEMANGLED_NAME (symbol
) != NULL
)
177 /* Try to figure out the appropriate namespace from the
180 /* FIXME: carlton/2003-04-15: If the function in question is
181 a method of a class, the name will actually include the
182 name of the class as well. This should be harmless, but
183 is a little unfortunate. */
185 const char *name
= SYMBOL_DEMANGLED_NAME (symbol
);
186 unsigned int prefix_len
= cp_entire_prefix_len (name
);
188 block_set_scope (block
,
189 obsavestring (name
, prefix_len
, obstack
),
194 /* Test whether or not NAMESPACE looks like it mentions an anonymous
195 namespace; return nonzero if so. */
198 cp_is_anonymous (const char *namespace)
200 return (strstr (namespace, "(anonymous namespace)")
204 /* Create a new struct using direct which imports the namespace SRC
206 Set its next member in the linked list to NEXT; allocate all memory
207 using xmalloc. It copies the strings, so NAME can be a temporary
210 struct using_direct
*
211 cp_add_using (const char *dest
,
213 struct using_direct
*next
)
215 struct using_direct
*retval
;
217 retval
= xmalloc (sizeof (struct using_direct
));
218 retval
->import_src
= savestring (src
, strlen(src
));
219 retval
->import_dest
= savestring (dest
, strlen(dest
));
225 /* Make a copy of the using directives in the list pointed to by
226 USING, using OBSTACK to allocate memory. Free all memory pointed
227 to by USING via xfree. */
229 static struct using_direct
*
230 cp_copy_usings (struct using_direct
*using,
231 struct obstack
*obstack
)
239 struct using_direct
*retval
240 = obstack_alloc (obstack
, sizeof (struct using_direct
));
241 retval
->import_src
= obsavestring (using->import_src
, strlen (using->import_src
),
243 retval
->import_dest
= obsavestring (using->import_dest
, strlen (using->import_dest
),
245 retval
->next
= cp_copy_usings (using->next
, obstack
);
247 xfree (using->import_src
);
248 xfree (using->import_dest
);
255 /* The C++-specific version of name lookup for static and global
256 names. This makes sure that names get looked for in all namespaces
257 that are in scope. NAME is the natural name of the symbol that
258 we're looking for, LINKAGE_NAME (which is optional) is its linkage
259 name, BLOCK is the block that we're searching within, DOMAIN says
260 what kind of symbols we're looking for, and if SYMTAB is non-NULL,
261 we should store the symtab where we found the symbol in it. */
264 cp_lookup_symbol_nonlocal (const char *name
,
265 const char *linkage_name
,
266 const struct block
*block
,
267 const domain_enum domain
)
269 return lookup_namespace_scope (name
, linkage_name
, block
, domain
,
270 block_scope (block
), 0);
273 /* Lookup NAME at namespace scope (or, in C terms, in static and
274 global variables). SCOPE is the namespace that the current
275 function is defined within; only consider namespaces whose length
276 is at least SCOPE_LEN. Other arguments are as in
277 cp_lookup_symbol_nonlocal.
279 For example, if we're within a function A::B::f and looking for a
280 symbol x, this will get called with NAME = "x", SCOPE = "A::B", and
281 SCOPE_LEN = 0. It then calls itself with NAME and SCOPE the same,
282 but with SCOPE_LEN = 1. And then it calls itself with NAME and
283 SCOPE the same, but with SCOPE_LEN = 4. This third call looks for
284 "A::B::x"; if it doesn't find it, then the second call looks for
285 "A::x", and if that call fails, then the first call looks for
288 static struct symbol
*
289 lookup_namespace_scope (const char *name
,
290 const char *linkage_name
,
291 const struct block
*block
,
292 const domain_enum domain
,
298 if (scope
[scope_len
] != '\0')
300 /* Recursively search for names in child namespaces first. */
303 int new_scope_len
= scope_len
;
305 /* If the current scope is followed by "::", skip past that. */
306 if (new_scope_len
!= 0)
308 gdb_assert (scope
[new_scope_len
] == ':');
311 new_scope_len
+= cp_find_first_component (scope
+ new_scope_len
);
312 sym
= lookup_namespace_scope (name
, linkage_name
, block
,
313 domain
, scope
, new_scope_len
);
318 /* Okay, we didn't find a match in our children, so look for the
319 name in the current namespace. */
321 namespace = alloca (scope_len
+ 1);
322 strncpy (namespace, scope
, scope_len
);
323 namespace[scope_len
] = '\0';
324 return cp_lookup_symbol_namespace (namespace, name
, linkage_name
,
328 /* Look up NAME in the C++ namespace NAMESPACE, applying the using
329 directives that are active in BLOCK. Other arguments are as in
330 cp_lookup_symbol_nonlocal. */
333 cp_lookup_symbol_namespace (const char *namespace,
335 const char *linkage_name
,
336 const struct block
*block
,
337 const domain_enum domain
)
339 const struct using_direct
*current
;
342 /* First, go through the using directives. If any of them add new
343 names to the namespace we're searching in, see if we can find a
344 match by applying them. */
346 for (current
= block_using (block
);
348 current
= current
->next
)
350 if (strcmp (namespace, current
->import_dest
) == 0)
352 sym
= cp_lookup_symbol_namespace (current
->import_src
,
362 /* We didn't find anything by applying any of the using directives
363 that are still applicable; so let's see if we've got a match
364 using the current namespace. */
366 if (namespace[0] == '\0')
368 return lookup_symbol_file (name
, linkage_name
, block
,
373 char *concatenated_name
374 = alloca (strlen (namespace) + 2 + strlen (name
) + 1);
375 strcpy (concatenated_name
, namespace);
376 strcat (concatenated_name
, "::");
377 strcat (concatenated_name
, name
);
378 sym
= lookup_symbol_file (concatenated_name
, linkage_name
,
380 cp_is_anonymous (namespace));
385 /* Look up NAME in BLOCK's static block and in global blocks. If
386 ANONYMOUS_NAMESPACE is nonzero, the symbol in question is located
387 within an anonymous namespace. Other arguments are as in
388 cp_lookup_symbol_nonlocal. */
390 static struct symbol
*
391 lookup_symbol_file (const char *name
,
392 const char *linkage_name
,
393 const struct block
*block
,
394 const domain_enum domain
,
395 int anonymous_namespace
)
397 struct symbol
*sym
= NULL
;
399 sym
= lookup_symbol_static (name
, linkage_name
, block
, domain
);
403 if (anonymous_namespace
)
405 /* Symbols defined in anonymous namespaces have external linkage
406 but should be treated as local to a single file nonetheless.
407 So we only search the current file's global block. */
409 const struct block
*global_block
= block_global_block (block
);
411 if (global_block
!= NULL
)
412 sym
= lookup_symbol_aux_block (name
, linkage_name
, global_block
,
417 sym
= lookup_symbol_global (name
, linkage_name
, block
, domain
);
423 /* Now call "lookup_possible_namespace_symbol". Symbols in here
424 claim to be associated to namespaces, but this claim might be
425 incorrect: the names in question might actually correspond to
426 classes instead of namespaces. But if they correspond to
427 classes, then we should have found a match for them above. So if
428 we find them now, they should be genuine. */
430 /* FIXME: carlton/2003-06-12: This is a hack and should eventually
431 be deleted: see comments below. */
433 if (domain
== VAR_DOMAIN
)
435 sym
= lookup_possible_namespace_symbol (name
);
443 /* Look up a type named NESTED_NAME that is nested inside the C++
444 class or namespace given by PARENT_TYPE, from within the context
445 given by BLOCK. Return NULL if there is no such nested type. */
448 cp_lookup_nested_type (struct type
*parent_type
,
449 const char *nested_name
,
450 const struct block
*block
)
452 switch (TYPE_CODE (parent_type
))
454 case TYPE_CODE_STRUCT
:
455 case TYPE_CODE_NAMESPACE
:
457 /* NOTE: carlton/2003-11-10: We don't treat C++ class members
458 of classes like, say, data or function members. Instead,
459 they're just represented by symbols whose names are
460 qualified by the name of the surrounding class. This is
461 just like members of namespaces; in particular,
462 lookup_symbol_namespace works when looking them up. */
464 const char *parent_name
= TYPE_TAG_NAME (parent_type
);
465 struct symbol
*sym
= cp_lookup_symbol_namespace (parent_name
,
470 if (sym
== NULL
|| SYMBOL_CLASS (sym
) != LOC_TYPEDEF
)
473 return SYMBOL_TYPE (sym
);
476 internal_error (__FILE__
, __LINE__
,
477 _("cp_lookup_nested_type called on a non-aggregate type."));
481 /* The C++-version of lookup_transparent_type. */
483 /* FIXME: carlton/2004-01-16: The problem that this is trying to
484 address is that, unfortunately, sometimes NAME is wrong: it may not
485 include the name of namespaces enclosing the type in question.
486 lookup_transparent_type gets called when the the type in question
487 is a declaration, and we're trying to find its definition; but, for
488 declarations, our type name deduction mechanism doesn't work.
489 There's nothing we can do to fix this in general, I think, in the
490 absence of debug information about namespaces (I've filed PR
491 gdb/1511 about this); until such debug information becomes more
492 prevalent, one heuristic which sometimes looks is to search for the
493 definition in namespaces containing the current namespace.
495 We should delete this functions once the appropriate debug
496 information becomes more widespread. (GCC 3.4 will be the first
497 released version of GCC with such information.) */
500 cp_lookup_transparent_type (const char *name
)
502 /* First, try the honest way of looking up the definition. */
503 struct type
*t
= basic_lookup_transparent_type (name
);
509 /* If that doesn't work and we're within a namespace, look there
511 scope
= block_scope (get_selected_block (0));
513 if (scope
[0] == '\0')
516 return cp_lookup_transparent_type_loop (name
, scope
, 0);
519 /* Lookup the the type definition associated to NAME in
520 namespaces/classes containing SCOPE whose name is strictly longer
521 than LENGTH. LENGTH must be the index of the start of a
522 component of SCOPE. */
525 cp_lookup_transparent_type_loop (const char *name
, const char *scope
,
528 int scope_length
= length
+ cp_find_first_component (scope
+ length
);
531 /* If the current scope is followed by "::", look in the next
533 if (scope
[scope_length
] == ':')
536 = cp_lookup_transparent_type_loop (name
, scope
, scope_length
+ 2);
541 full_name
= alloca (scope_length
+ 2 + strlen (name
) + 1);
542 strncpy (full_name
, scope
, scope_length
);
543 strncpy (full_name
+ scope_length
, "::", 2);
544 strcpy (full_name
+ scope_length
+ 2, name
);
546 return basic_lookup_transparent_type (full_name
);
549 /* Now come functions for dealing with symbols associated to
550 namespaces. (They're used to store the namespaces themselves, not
551 objects that live in the namespaces.) These symbols come in two
552 varieties: if we run into a DW_TAG_namespace DIE, then we know that
553 we have a namespace, so dwarf2read.c creates a symbol for it just
554 like normal. But, unfortunately, versions of GCC through at least
555 3.3 don't generate those DIE's. Our solution is to try to guess
556 their existence by looking at demangled names. This might cause us
557 to misidentify classes as namespaces, however. So we put those
558 symbols in a special block (one per objfile), and we only search
559 that block as a last resort. */
561 /* FIXME: carlton/2003-06-12: Once versions of GCC that generate
562 DW_TAG_namespace have been out for a year or two, we should get rid
563 of all of this "possible namespace" nonsense. */
565 /* Allocate everything necessary for the possible namespace block
566 associated to OBJFILE. */
569 initialize_namespace_symtab (struct objfile
*objfile
)
571 struct symtab
*namespace_symtab
;
572 struct blockvector
*bv
;
575 namespace_symtab
= allocate_symtab ("<<C++-namespaces>>", objfile
);
576 namespace_symtab
->language
= language_cplus
;
577 namespace_symtab
->free_code
= free_nothing
;
578 namespace_symtab
->dirname
= NULL
;
580 bv
= obstack_alloc (&objfile
->objfile_obstack
,
581 sizeof (struct blockvector
)
582 + FIRST_LOCAL_BLOCK
* sizeof (struct block
*));
583 BLOCKVECTOR_NBLOCKS (bv
) = FIRST_LOCAL_BLOCK
+ 1;
584 BLOCKVECTOR (namespace_symtab
) = bv
;
586 /* Allocate empty GLOBAL_BLOCK and STATIC_BLOCK. */
588 bl
= allocate_block (&objfile
->objfile_obstack
);
589 BLOCK_DICT (bl
) = dict_create_linear (&objfile
->objfile_obstack
,
591 BLOCKVECTOR_BLOCK (bv
, GLOBAL_BLOCK
) = bl
;
592 bl
= allocate_block (&objfile
->objfile_obstack
);
593 BLOCK_DICT (bl
) = dict_create_linear (&objfile
->objfile_obstack
,
595 BLOCKVECTOR_BLOCK (bv
, STATIC_BLOCK
) = bl
;
597 /* Allocate the possible namespace block; we put it where the first
598 local block will live, though I don't think there's any need to
599 pretend that it's actually a local block (e.g. by setting
600 BLOCK_SUPERBLOCK appropriately). We don't use the global or
601 static block because we don't want it searched during the normal
602 search of all global/static blocks in lookup_symbol: we only want
603 it used as a last resort. */
605 /* NOTE: carlton/2003-09-11: I considered not associating the fake
606 symbols to a block/symtab at all. But that would cause problems
607 with lookup_symbol's SYMTAB argument and with block_found, so
608 having a symtab/block for this purpose seems like the best
611 bl
= allocate_block (&objfile
->objfile_obstack
);
612 BLOCK_DICT (bl
) = dict_create_hashed_expandable ();
613 BLOCKVECTOR_BLOCK (bv
, FIRST_LOCAL_BLOCK
) = bl
;
615 namespace_symtab
->free_func
= free_namespace_block
;
617 objfile
->cp_namespace_symtab
= namespace_symtab
;
620 /* Locate the possible namespace block associated to OBJFILE,
621 allocating it if necessary. */
623 static struct block
*
624 get_possible_namespace_block (struct objfile
*objfile
)
626 if (objfile
->cp_namespace_symtab
== NULL
)
627 initialize_namespace_symtab (objfile
);
629 return BLOCKVECTOR_BLOCK (BLOCKVECTOR (objfile
->cp_namespace_symtab
),
633 /* Free the dictionary associated to the possible namespace block. */
636 free_namespace_block (struct symtab
*symtab
)
638 struct block
*possible_namespace_block
;
640 possible_namespace_block
= BLOCKVECTOR_BLOCK (BLOCKVECTOR (symtab
),
642 gdb_assert (possible_namespace_block
!= NULL
);
643 dict_free (BLOCK_DICT (possible_namespace_block
));
646 /* Ensure that there are symbols in the possible namespace block
647 associated to OBJFILE for all initial substrings of NAME that look
648 like namespaces or classes. NAME should end in a member variable:
649 it shouldn't consist solely of namespaces. */
652 cp_check_possible_namespace_symbols (const char *name
, struct objfile
*objfile
)
654 check_possible_namespace_symbols_loop (name
,
655 cp_find_first_component (name
),
659 /* This is a helper loop for cp_check_possible_namespace_symbols; it
660 ensures that there are symbols in the possible namespace block
661 associated to OBJFILE for all namespaces that are initial
662 substrings of NAME of length at least LEN. It returns 1 if a
663 previous loop had already created the shortest such symbol and 0
666 This function assumes that if there is already a symbol associated
667 to a substring of NAME of a given length, then there are already
668 symbols associated to all substrings of NAME whose length is less
669 than that length. So if cp_check_possible_namespace_symbols has
670 been called once with argument "A::B::C::member", then that will
671 create symbols "A", "A::B", and "A::B::C". If it is then later
672 called with argument "A::B::D::member", then the new call will
673 generate a new symbol for "A::B::D", but once it sees that "A::B"
674 has already been created, it doesn't bother checking to see if "A"
675 has also been created. */
678 check_possible_namespace_symbols_loop (const char *name
, int len
,
679 struct objfile
*objfile
)
681 if (name
[len
] == ':')
684 int next_len
= len
+ 2;
686 next_len
+= cp_find_first_component (name
+ next_len
);
687 done
= check_possible_namespace_symbols_loop (name
, next_len
,
691 done
= check_one_possible_namespace_symbol (name
, len
, objfile
);
699 /* Check to see if there's already a possible namespace symbol in
700 OBJFILE whose name is the initial substring of NAME of length LEN.
701 If not, create one and return 0; otherwise, return 1. */
704 check_one_possible_namespace_symbol (const char *name
, int len
,
705 struct objfile
*objfile
)
707 struct block
*block
= get_possible_namespace_block (objfile
);
708 char *name_copy
= alloca (len
+ 1);
711 memcpy (name_copy
, name
, len
);
712 name_copy
[len
] = '\0';
713 sym
= lookup_block_symbol (block
, name_copy
, NULL
, VAR_DOMAIN
);
719 type
= init_type (TYPE_CODE_NAMESPACE
, 0, 0, name_copy
, objfile
);
721 TYPE_TAG_NAME (type
) = TYPE_NAME (type
);
723 sym
= obstack_alloc (&objfile
->objfile_obstack
, sizeof (struct symbol
));
724 memset (sym
, 0, sizeof (struct symbol
));
725 SYMBOL_LANGUAGE (sym
) = language_cplus
;
726 /* Note that init_type copied the name to the objfile's
728 SYMBOL_SET_NAMES (sym
, TYPE_NAME (type
), len
, 0, objfile
);
729 SYMBOL_CLASS (sym
) = LOC_TYPEDEF
;
730 SYMBOL_TYPE (sym
) = type
;
731 SYMBOL_DOMAIN (sym
) = VAR_DOMAIN
;
733 dict_add_symbol (BLOCK_DICT (block
), sym
);
741 /* Look for a symbol named NAME in all the possible namespace blocks.
742 If one is found, return it. */
744 static struct symbol
*
745 lookup_possible_namespace_symbol (const char *name
)
747 struct objfile
*objfile
;
749 ALL_OBJFILES (objfile
)
753 sym
= lookup_block_symbol (get_possible_namespace_block (objfile
),
754 name
, NULL
, VAR_DOMAIN
);
763 /* Print out all the possible namespace symbols. */
766 maintenance_cplus_namespace (char *args
, int from_tty
)
768 struct objfile
*objfile
;
769 printf_unfiltered (_("Possible namespaces:\n"));
770 ALL_OBJFILES (objfile
)
772 struct dict_iterator iter
;
775 ALL_BLOCK_SYMBOLS (get_possible_namespace_block (objfile
), iter
, sym
)
777 printf_unfiltered ("%s\n", SYMBOL_PRINT_NAME (sym
));
782 /* Provide a prototype to silence -Wmissing-prototypes. */
783 extern initialize_file_ftype _initialize_cp_namespace
;
786 _initialize_cp_namespace (void)
788 add_cmd ("namespace", class_maintenance
, maintenance_cplus_namespace
,
789 _("Print the list of possible C++ namespaces."),
790 &maint_cplus_cmd_list
);