gdb/block.c

   1 /* Block-related functions for the GNU debugger, GDB.
   2
   3    Copyright (C) 2003-2015 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   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.
  11
  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.
  16
  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/>.  */
  19
  20 #include "defs.h"
  21 #include "block.h"
  22 #include "symtab.h"
  23 #include "symfile.h"
  24 #include "gdb_obstack.h"
  25 #include "cp-support.h"
  26 #include "addrmap.h"
  27 #include "gdbtypes.h"
  28 #include "objfiles.h"
  29
  30 /* This is used by struct block to store namespace-related info for
  31    C++ files, namely using declarations and the current namespace in
  32    scope.  */
  33
  34 struct block_namespace_info
  35 {
  36   const char *scope;
  37   struct using_direct *using_decl;
  38 };
  39
  40 static void block_initialize_namespace (struct block *block,
  41                                         struct obstack *obstack);
  42
  43 /* See block.h.  */
  44
  45 struct objfile *
  46 block_objfile (const struct block *block)
  47 {
  48   const struct global_block *global_block;
  49
  50   if (BLOCK_FUNCTION (block) != NULL)
  51     return symbol_objfile (BLOCK_FUNCTION (block));
  52
  53   global_block = (struct global_block *) block_global_block (block);
  54   return COMPUNIT_OBJFILE (global_block->compunit_symtab);
  55 }
  56
  57 /* See block.  */
  58
  59 struct gdbarch *
  60 block_gdbarch (const struct block *block)
  61 {
  62   if (BLOCK_FUNCTION (block) != NULL)
  63     return symbol_arch (BLOCK_FUNCTION (block));
  64
  65   return get_objfile_arch (block_objfile (block));
  66 }
  67
  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.  */
  71
  72 int
  73 contained_in (const struct block *a, const struct block *b)
  74 {
  75   if (!a || !b)
  76     return 0;
  77
  78   do
  79     {
  80       if (a == b)
  81         return 1;
  82       /* If A is a function block, then A cannot be contained in B,
  83          except if A was inlined.  */
  84       if (BLOCK_FUNCTION (a) != NULL && !block_inlined_p (a))
  85         return 0;
  86       a = BLOCK_SUPERBLOCK (a);
  87     }
  88   while (a != NULL);
  89
  90   return 0;
  91 }
  92
  93
  94 /* Return the symbol for the function which contains a specified
  95    lexical block, described by a struct block BL.  The return value
  96    will not be an inlined function; the containing function will be
  97    returned instead.  */
  98
  99 struct symbol *
 100 block_linkage_function (const struct block *bl)
 101 {
 102   while ((BLOCK_FUNCTION (bl) == NULL || block_inlined_p (bl))
 103          && BLOCK_SUPERBLOCK (bl) != NULL)
 104     bl = BLOCK_SUPERBLOCK (bl);
 105
 106   return BLOCK_FUNCTION (bl);
 107 }
 108
 109 /* Return the symbol for the function which contains a specified
 110    block, described by a struct block BL.  The return value will be
 111    the closest enclosing function, which might be an inline
 112    function.  */
 113
 114 struct symbol *
 115 block_containing_function (const struct block *bl)
 116 {
 117   while (BLOCK_FUNCTION (bl) == NULL && BLOCK_SUPERBLOCK (bl) != NULL)
 118     bl = BLOCK_SUPERBLOCK (bl);
 119
 120   return BLOCK_FUNCTION (bl);
 121 }
 122
 123 /* Return one if BL represents an inlined function.  */
 124
 125 int
 126 block_inlined_p (const struct block *bl)
 127 {
 128   return BLOCK_FUNCTION (bl) != NULL && SYMBOL_INLINED (BLOCK_FUNCTION (bl));
 129 }
 130
 131 /* A helper function that checks whether PC is in the blockvector BL.
 132    It returns the containing block if there is one, or else NULL.  */
 133
 134 static struct block *
 135 find_block_in_blockvector (const struct blockvector *bl, CORE_ADDR pc)
 136 {
 137   struct block *b;
 138   int bot, top, half;
 139
 140   /* If we have an addrmap mapping code addresses to blocks, then use
 141      that.  */
 142   if (BLOCKVECTOR_MAP (bl))
 143     return addrmap_find (BLOCKVECTOR_MAP (bl), pc);
 144
 145   /* Otherwise, use binary search to find the last block that starts
 146      before PC.
 147      Note: GLOBAL_BLOCK is block 0, STATIC_BLOCK is block 1.
 148      They both have the same START,END values.
 149      Historically this code would choose STATIC_BLOCK over GLOBAL_BLOCK but the
 150      fact that this choice was made was subtle, now we make it explicit.  */
 151   gdb_assert (BLOCKVECTOR_NBLOCKS (bl) >= 2);
 152   bot = STATIC_BLOCK;
 153   top = BLOCKVECTOR_NBLOCKS (bl);
 154
 155   while (top - bot > 1)
 156     {
 157       half = (top - bot + 1) >> 1;
 158       b = BLOCKVECTOR_BLOCK (bl, bot + half);
 159       if (BLOCK_START (b) <= pc)
 160         bot += half;
 161       else
 162         top = bot + half;
 163     }
 164
 165   /* Now search backward for a block that ends after PC.  */
 166
 167   while (bot >= STATIC_BLOCK)
 168     {
 169       b = BLOCKVECTOR_BLOCK (bl, bot);
 170       if (BLOCK_END (b) > pc)
 171         return b;
 172       bot--;
 173     }
 174
 175   return NULL;
 176 }
 177
 178 /* Return the blockvector immediately containing the innermost lexical
 179    block containing the specified pc value and section, or 0 if there
 180    is none.  PBLOCK is a pointer to the block.  If PBLOCK is NULL, we
 181    don't pass this information back to the caller.  */
 182
 183 const struct blockvector *
 184 blockvector_for_pc_sect (CORE_ADDR pc, struct obj_section *section,
 185                          const struct block **pblock,
 186                          struct compunit_symtab *cust)
 187 {
 188   const struct blockvector *bl;
 189   struct block *b;
 190
 191   if (cust == NULL)
 192     {
 193       /* First search all symtabs for one whose file contains our pc */
 194       cust = find_pc_sect_compunit_symtab (pc, section);
 195       if (cust == NULL)
 196         return 0;
 197     }
 198
 199   bl = COMPUNIT_BLOCKVECTOR (cust);
 200
 201   /* Then search that symtab for the smallest block that wins.  */
 202   b = find_block_in_blockvector (bl, pc);
 203   if (b == NULL)
 204     return NULL;
 205
 206   if (pblock)
 207     *pblock = b;
 208   return bl;
 209 }
 210
 211 /* Return true if the blockvector BV contains PC, false otherwise.  */
 212
 213 int
 214 blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc)
 215 {
 216   return find_block_in_blockvector (bv, pc) != NULL;
 217 }
 218
 219 /* Return call_site for specified PC in GDBARCH.  PC must match exactly, it
 220    must be the next instruction after call (or after tail call jump).  Throw
 221    NO_ENTRY_VALUE_ERROR otherwise.  This function never returns NULL.  */
 222
 223 struct call_site *
 224 call_site_for_pc (struct gdbarch *gdbarch, CORE_ADDR pc)
 225 {
 226   struct compunit_symtab *cust;
 227   void **slot = NULL;
 228
 229   /* -1 as tail call PC can be already after the compilation unit range.  */
 230   cust = find_pc_compunit_symtab (pc - 1);
 231
 232   if (cust != NULL && COMPUNIT_CALL_SITE_HTAB (cust) != NULL)
 233     slot = htab_find_slot (COMPUNIT_CALL_SITE_HTAB (cust), &pc, NO_INSERT);
 234
 235   if (slot == NULL)
 236     {
 237       struct bound_minimal_symbol msym = lookup_minimal_symbol_by_pc (pc);
 238
 239       /* DW_TAG_gnu_call_site will be missing just if GCC could not determine
 240          the call target.  */
 241       throw_error (NO_ENTRY_VALUE_ERROR,
 242                    _("DW_OP_GNU_entry_value resolving cannot find "
 243                      "DW_TAG_GNU_call_site %s in %s"),
 244                    paddress (gdbarch, pc),
 245                    (msym.minsym == NULL ? "???"
 246                     : MSYMBOL_PRINT_NAME (msym.minsym)));
 247     }
 248
 249   return *slot;
 250 }
 251
 252 /* Return the blockvector immediately containing the innermost lexical block
 253    containing the specified pc value, or 0 if there is none.
 254    Backward compatibility, no section.  */
 255
 256 const struct blockvector *
 257 blockvector_for_pc (CORE_ADDR pc, const struct block **pblock)
 258 {
 259   return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
 260                                   pblock, NULL);
 261 }
 262
 263 /* Return the innermost lexical block containing the specified pc value
 264    in the specified section, or 0 if there is none.  */
 265
 266 const struct block *
 267 block_for_pc_sect (CORE_ADDR pc, struct obj_section *section)
 268 {
 269   const struct blockvector *bl;
 270   const struct block *b;
 271
 272   bl = blockvector_for_pc_sect (pc, section, &b, NULL);
 273   if (bl)
 274     return b;
 275   return 0;
 276 }
 277
 278 /* Return the innermost lexical block containing the specified pc value,
 279    or 0 if there is none.  Backward compatibility, no section.  */
 280
 281 const struct block *
 282 block_for_pc (CORE_ADDR pc)
 283 {
 284   return block_for_pc_sect (pc, find_pc_mapped_section (pc));
 285 }
 286
 287 /* Now come some functions designed to deal with C++ namespace issues.
 288    The accessors are safe to use even in the non-C++ case.  */
 289
 290 /* This returns the namespace that BLOCK is enclosed in, or "" if it
 291    isn't enclosed in a namespace at all.  This travels the chain of
 292    superblocks looking for a scope, if necessary.  */
 293
 294 const char *
 295 block_scope (const struct block *block)
 296 {
 297   for (; block != NULL; block = BLOCK_SUPERBLOCK (block))
 298     {
 299       if (BLOCK_NAMESPACE (block) != NULL
 300           && BLOCK_NAMESPACE (block)->scope != NULL)
 301         return BLOCK_NAMESPACE (block)->scope;
 302     }
 303
 304   return "";
 305 }
 306
 307 /* Set BLOCK's scope member to SCOPE; if needed, allocate memory via
 308    OBSTACK.  (It won't make a copy of SCOPE, however, so that already
 309    has to be allocated correctly.)  */
 310
 311 void
 312 block_set_scope (struct block *block, const char *scope,
 313                  struct obstack *obstack)
 314 {
 315   block_initialize_namespace (block, obstack);
 316
 317   BLOCK_NAMESPACE (block)->scope = scope;
 318 }
 319
 320 /* This returns the using directives list associated with BLOCK, if
 321    any.  */
 322
 323 struct using_direct *
 324 block_using (const struct block *block)
 325 {
 326   if (block == NULL || BLOCK_NAMESPACE (block) == NULL)
 327     return NULL;
 328   else
 329     return BLOCK_NAMESPACE (block)->using_decl;
 330 }
 331
 332 /* Set BLOCK's using member to USING; if needed, allocate memory via
 333    OBSTACK.  (It won't make a copy of USING, however, so that already
 334    has to be allocated correctly.)  */
 335
 336 void
 337 block_set_using (struct block *block,
 338                  struct using_direct *using_decl,
 339                  struct obstack *obstack)
 340 {
 341   block_initialize_namespace (block, obstack);
 342
 343   BLOCK_NAMESPACE (block)->using_decl = using_decl;
 344 }
 345
 346 /* If BLOCK_NAMESPACE (block) is NULL, allocate it via OBSTACK and
 347    ititialize its members to zero.  */
 348
 349 static void
 350 block_initialize_namespace (struct block *block, struct obstack *obstack)
 351 {
 352   if (BLOCK_NAMESPACE (block) == NULL)
 353     {
 354       BLOCK_NAMESPACE (block)
 355         = obstack_alloc (obstack, sizeof (struct block_namespace_info));
 356       BLOCK_NAMESPACE (block)->scope = NULL;
 357       BLOCK_NAMESPACE (block)->using_decl = NULL;
 358     }
 359 }
 360
 361 /* Return the static block associated to BLOCK.  Return NULL if block
 362    is NULL or if block is a global block.  */
 363
 364 const struct block *
 365 block_static_block (const struct block *block)
 366 {
 367   if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL)
 368     return NULL;
 369
 370   while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL)
 371     block = BLOCK_SUPERBLOCK (block);
 372
 373   return block;
 374 }
 375
 376 /* Return the static block associated to BLOCK.  Return NULL if block
 377    is NULL.  */
 378
 379 const struct block *
 380 block_global_block (const struct block *block)
 381 {
 382   if (block == NULL)
 383     return NULL;
 384
 385   while (BLOCK_SUPERBLOCK (block) != NULL)
 386     block = BLOCK_SUPERBLOCK (block);
 387
 388   return block;
 389 }
 390
 391 /* Allocate a block on OBSTACK, and initialize its elements to
 392    zero/NULL.  This is useful for creating "dummy" blocks that don't
 393    correspond to actual source files.
 394
 395    Warning: it sets the block's BLOCK_DICT to NULL, which isn't a
 396    valid value.  If you really don't want the block to have a
 397    dictionary, then you should subsequently set its BLOCK_DICT to
 398    dict_create_linear (obstack, NULL).  */
 399
 400 struct block *
 401 allocate_block (struct obstack *obstack)
 402 {
 403   struct block *bl = OBSTACK_ZALLOC (obstack, struct block);
 404
 405   return bl;
 406 }
 407
 408 /* Allocate a global block.  */
 409
 410 struct block *
 411 allocate_global_block (struct obstack *obstack)
 412 {
 413   struct global_block *bl = OBSTACK_ZALLOC (obstack, struct global_block);
 414
 415   return &bl->block;
 416 }
 417
 418 /* Set the compunit of the global block.  */
 419
 420 void
 421 set_block_compunit_symtab (struct block *block, struct compunit_symtab *cu)
 422 {
 423   struct global_block *gb;
 424
 425   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
 426   gb = (struct global_block *) block;
 427   gdb_assert (gb->compunit_symtab == NULL);
 428   gb->compunit_symtab = cu;
 429 }
 430
 431 /* See block.h.  */
 432
 433 struct dynamic_prop *
 434 block_static_link (const struct block *block)
 435 {
 436   struct objfile *objfile = block_objfile (block);
 437
 438   /* Only objfile-owned blocks that materialize top function scopes can have
 439      static links.  */
 440   if (objfile == NULL || BLOCK_FUNCTION (block) == NULL)
 441     return NULL;
 442
 443   return (struct dynamic_prop *) objfile_lookup_static_link (objfile, block);
 444 }
 445
 446 /* Return the compunit of the global block.  */
 447
 448 static struct compunit_symtab *
 449 get_block_compunit_symtab (const struct block *block)
 450 {
 451   struct global_block *gb;
 452
 453   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
 454   gb = (struct global_block *) block;
 455   gdb_assert (gb->compunit_symtab != NULL);
 456   return gb->compunit_symtab;
 457 }
 458
 459 \f
 460
 461 /* Initialize a block iterator, either to iterate over a single block,
 462    or, for static and global blocks, all the included symtabs as
 463    well.  */
 464
 465 static void
 466 initialize_block_iterator (const struct block *block,
 467                            struct block_iterator *iter)
 468 {
 469   enum block_enum which;
 470   struct compunit_symtab *cu;
 471
 472   iter->idx = -1;
 473
 474   if (BLOCK_SUPERBLOCK (block) == NULL)
 475     {
 476       which = GLOBAL_BLOCK;
 477       cu = get_block_compunit_symtab (block);
 478     }
 479   else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL)
 480     {
 481       which = STATIC_BLOCK;
 482       cu = get_block_compunit_symtab (BLOCK_SUPERBLOCK (block));
 483     }
 484   else
 485     {
 486       iter->d.block = block;
 487       /* A signal value meaning that we're iterating over a single
 488          block.  */
 489       iter->which = FIRST_LOCAL_BLOCK;
 490       return;
 491     }
 492
 493   /* If this is an included symtab, find the canonical includer and
 494      use it instead.  */
 495   while (cu->user != NULL)
 496     cu = cu->user;
 497
 498   /* Putting this check here simplifies the logic of the iterator
 499      functions.  If there are no included symtabs, we only need to
 500      search a single block, so we might as well just do that
 501      directly.  */
 502   if (cu->includes == NULL)
 503     {
 504       iter->d.block = block;
 505       /* A signal value meaning that we're iterating over a single
 506          block.  */
 507       iter->which = FIRST_LOCAL_BLOCK;
 508     }
 509   else
 510     {
 511       iter->d.compunit_symtab = cu;
 512       iter->which = which;
 513     }
 514 }
 515
 516 /* A helper function that finds the current compunit over whose static
 517    or global block we should iterate.  */
 518
 519 static struct compunit_symtab *
 520 find_iterator_compunit_symtab (struct block_iterator *iterator)
 521 {
 522   if (iterator->idx == -1)
 523     return iterator->d.compunit_symtab;
 524   return iterator->d.compunit_symtab->includes[iterator->idx];
 525 }
 526
 527 /* Perform a single step for a plain block iterator, iterating across
 528    symbol tables as needed.  Returns the next symbol, or NULL when
 529    iteration is complete.  */
 530
 531 static struct symbol *
 532 block_iterator_step (struct block_iterator *iterator, int first)
 533 {
 534   struct symbol *sym;
 535
 536   gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
 537
 538   while (1)
 539     {
 540       if (first)
 541         {
 542           struct compunit_symtab *cust
 543             = find_iterator_compunit_symtab (iterator);
 544           const struct block *block;
 545
 546           /* Iteration is complete.  */
 547           if (cust == NULL)
 548             return  NULL;
 549
 550           block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
 551                                      iterator->which);
 552           sym = dict_iterator_first (BLOCK_DICT (block), &iterator->dict_iter);
 553         }
 554       else
 555         sym = dict_iterator_next (&iterator->dict_iter);
 556
 557       if (sym != NULL)
 558         return sym;
 559
 560       /* We have finished iterating the appropriate block of one
 561          symtab.  Now advance to the next symtab and begin iteration
 562          there.  */
 563       ++iterator->idx;
 564       first = 1;
 565     }
 566 }
 567
 568 /* See block.h.  */
 569
 570 struct symbol *
 571 block_iterator_first (const struct block *block,
 572                       struct block_iterator *iterator)
 573 {
 574   initialize_block_iterator (block, iterator);
 575
 576   if (iterator->which == FIRST_LOCAL_BLOCK)
 577     return dict_iterator_first (block->dict, &iterator->dict_iter);
 578
 579   return block_iterator_step (iterator, 1);
 580 }
 581
 582 /* See block.h.  */
 583
 584 struct symbol *
 585 block_iterator_next (struct block_iterator *iterator)
 586 {
 587   if (iterator->which == FIRST_LOCAL_BLOCK)
 588     return dict_iterator_next (&iterator->dict_iter);
 589
 590   return block_iterator_step (iterator, 0);
 591 }
 592
 593 /* Perform a single step for a "name" block iterator, iterating across
 594    symbol tables as needed.  Returns the next symbol, or NULL when
 595    iteration is complete.  */
 596
 597 static struct symbol *
 598 block_iter_name_step (struct block_iterator *iterator, const char *name,
 599                       int first)
 600 {
 601   struct symbol *sym;
 602
 603   gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
 604
 605   while (1)
 606     {
 607       if (first)
 608         {
 609           struct compunit_symtab *cust
 610             = find_iterator_compunit_symtab (iterator);
 611           const struct block *block;
 612
 613           /* Iteration is complete.  */
 614           if (cust == NULL)
 615             return  NULL;
 616
 617           block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
 618                                      iterator->which);
 619           sym = dict_iter_name_first (BLOCK_DICT (block), name,
 620                                       &iterator->dict_iter);
 621         }
 622       else
 623         sym = dict_iter_name_next (name, &iterator->dict_iter);
 624
 625       if (sym != NULL)
 626         return sym;
 627
 628       /* We have finished iterating the appropriate block of one
 629          symtab.  Now advance to the next symtab and begin iteration
 630          there.  */
 631       ++iterator->idx;
 632       first = 1;
 633     }
 634 }
 635
 636 /* See block.h.  */
 637
 638 struct symbol *
 639 block_iter_name_first (const struct block *block,
 640                        const char *name,
 641                        struct block_iterator *iterator)
 642 {
 643   initialize_block_iterator (block, iterator);
 644
 645   if (iterator->which == FIRST_LOCAL_BLOCK)
 646     return dict_iter_name_first (block->dict, name, &iterator->dict_iter);
 647
 648   return block_iter_name_step (iterator, name, 1);
 649 }
 650
 651 /* See block.h.  */
 652
 653 struct symbol *
 654 block_iter_name_next (const char *name, struct block_iterator *iterator)
 655 {
 656   if (iterator->which == FIRST_LOCAL_BLOCK)
 657     return dict_iter_name_next (name, &iterator->dict_iter);
 658
 659   return block_iter_name_step (iterator, name, 0);
 660 }
 661
 662 /* Perform a single step for a "match" block iterator, iterating
 663    across symbol tables as needed.  Returns the next symbol, or NULL
 664    when iteration is complete.  */
 665
 666 static struct symbol *
 667 block_iter_match_step (struct block_iterator *iterator,
 668                        const char *name,
 669                        symbol_compare_ftype *compare,
 670                        int first)
 671 {
 672   struct symbol *sym;
 673
 674   gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
 675
 676   while (1)
 677     {
 678       if (first)
 679         {
 680           struct compunit_symtab *cust
 681             = find_iterator_compunit_symtab (iterator);
 682           const struct block *block;
 683
 684           /* Iteration is complete.  */
 685           if (cust == NULL)
 686             return  NULL;
 687
 688           block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
 689                                      iterator->which);
 690           sym = dict_iter_match_first (BLOCK_DICT (block), name,
 691                                        compare, &iterator->dict_iter);
 692         }
 693       else
 694         sym = dict_iter_match_next (name, compare, &iterator->dict_iter);
 695
 696       if (sym != NULL)
 697         return sym;
 698
 699       /* We have finished iterating the appropriate block of one
 700          symtab.  Now advance to the next symtab and begin iteration
 701          there.  */
 702       ++iterator->idx;
 703       first = 1;
 704     }
 705 }
 706
 707 /* See block.h.  */
 708
 709 struct symbol *
 710 block_iter_match_first (const struct block *block,
 711                         const char *name,
 712                         symbol_compare_ftype *compare,
 713                         struct block_iterator *iterator)
 714 {
 715   initialize_block_iterator (block, iterator);
 716
 717   if (iterator->which == FIRST_LOCAL_BLOCK)
 718     return dict_iter_match_first (block->dict, name, compare,
 719                                   &iterator->dict_iter);
 720
 721   return block_iter_match_step (iterator, name, compare, 1);
 722 }
 723
 724 /* See block.h.  */
 725
 726 struct symbol *
 727 block_iter_match_next (const char *name,
 728                        symbol_compare_ftype *compare,
 729                        struct block_iterator *iterator)
 730 {
 731   if (iterator->which == FIRST_LOCAL_BLOCK)
 732     return dict_iter_match_next (name, compare, &iterator->dict_iter);
 733
 734   return block_iter_match_step (iterator, name, compare, 0);
 735 }
 736
 737 /* See block.h.
 738
 739    Note that if NAME is the demangled form of a C++ symbol, we will fail
 740    to find a match during the binary search of the non-encoded names, but
 741    for now we don't worry about the slight inefficiency of looking for
 742    a match we'll never find, since it will go pretty quick.  Once the
 743    binary search terminates, we drop through and do a straight linear
 744    search on the symbols.  Each symbol which is marked as being a ObjC/C++
 745    symbol (language_cplus or language_objc set) has both the encoded and
 746    non-encoded names tested for a match.  */
 747
 748 struct symbol *
 749 block_lookup_symbol (const struct block *block, const char *name,
 750                      const domain_enum domain)
 751 {
 752   struct block_iterator iter;
 753   struct symbol *sym;
 754
 755   if (!BLOCK_FUNCTION (block))
 756     {
 757       struct symbol *other = NULL;
 758
 759       ALL_BLOCK_SYMBOLS_WITH_NAME (block, name, iter, sym)
 760         {
 761           if (SYMBOL_DOMAIN (sym) == domain)
 762             return sym;
 763           /* This is a bit of a hack, but symbol_matches_domain might ignore
 764              STRUCT vs VAR domain symbols.  So if a matching symbol is found,
 765              make sure there is no "better" matching symbol, i.e., one with
 766              exactly the same domain.  PR 16253.  */
 767           if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 768                                      SYMBOL_DOMAIN (sym), domain))
 769             other = sym;
 770         }
 771       return other;
 772     }
 773   else
 774     {
 775       /* Note that parameter symbols do not always show up last in the
 776          list; this loop makes sure to take anything else other than
 777          parameter symbols first; it only uses parameter symbols as a
 778          last resort.  Note that this only takes up extra computation
 779          time on a match.
 780          It's hard to define types in the parameter list (at least in
 781          C/C++) so we don't do the same PR 16253 hack here that is done
 782          for the !BLOCK_FUNCTION case.  */
 783
 784       struct symbol *sym_found = NULL;
 785
 786       ALL_BLOCK_SYMBOLS_WITH_NAME (block, name, iter, sym)
 787         {
 788           if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 789                                      SYMBOL_DOMAIN (sym), domain))
 790             {
 791               sym_found = sym;
 792               if (!SYMBOL_IS_ARGUMENT (sym))
 793                 {
 794                   break;
 795                 }
 796             }
 797         }
 798       return (sym_found);       /* Will be NULL if not found.  */
 799     }
 800 }
 801
 802 /* See block.h.  */
 803
 804 struct symbol *
 805 block_lookup_symbol_primary (const struct block *block, const char *name,
 806                              const domain_enum domain)
 807 {
 808   struct symbol *sym, *other;
 809   struct dict_iterator dict_iter;
 810
 811   /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK.  */
 812   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
 813               || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
 814
 815   other = NULL;
 816   for (sym = dict_iter_name_first (block->dict, name, &dict_iter);
 817        sym != NULL;
 818        sym = dict_iter_name_next (name, &dict_iter))
 819     {
 820       if (SYMBOL_DOMAIN (sym) == domain)
 821         return sym;
 822
 823       /* This is a bit of a hack, but symbol_matches_domain might ignore
 824          STRUCT vs VAR domain symbols.  So if a matching symbol is found,
 825          make sure there is no "better" matching symbol, i.e., one with
 826          exactly the same domain.  PR 16253.  */
 827       if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 828                                  SYMBOL_DOMAIN (sym), domain))
 829         other = sym;
 830     }
 831
 832   return other;
 833 }
 834
 835 /* See block.h.  */
 836
 837 struct symbol *
 838 block_find_symbol (const struct block *block, const char *name,
 839                    const domain_enum domain,
 840                    block_symbol_matcher_ftype *matcher, void *data)
 841 {
 842   struct block_iterator iter;
 843   struct symbol *sym;
 844
 845   /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK.  */
 846   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
 847               || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
 848
 849   ALL_BLOCK_SYMBOLS_WITH_NAME (block, name, iter, sym)
 850     {
 851       /* MATCHER is deliberately called second here so that it never sees
 852          a non-domain-matching symbol.  */
 853       if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 854                                  SYMBOL_DOMAIN (sym), domain)
 855           && matcher (sym, data))
 856         return sym;
 857     }
 858   return NULL;
 859 }
 860
 861 /* See block.h.  */
 862
 863 int
 864 block_find_non_opaque_type (struct symbol *sym, void *data)
 865 {
 866   return !TYPE_IS_OPAQUE (SYMBOL_TYPE (sym));
 867 }
 868
 869 /* See block.h.  */
 870
 871 int
 872 block_find_non_opaque_type_preferred (struct symbol *sym, void *data)
 873 {
 874   struct symbol **best = data;
 875
 876   if (!TYPE_IS_OPAQUE (SYMBOL_TYPE (sym)))
 877     return 1;
 878   *best = sym;
 879   return 0;
 880 }