gdb/block.c

   1 /* Block-related functions for the GNU debugger, GDB.
   2
   3    Copyright (C) 2003-2016 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 (struct block *) 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 (struct call_site *) *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) = XOBNEW (obstack, struct block_namespace_info);
 355       BLOCK_NAMESPACE (block)->scope = NULL;
 356       BLOCK_NAMESPACE (block)->using_decl = NULL;
 357     }
 358 }
 359
 360 /* Return the static block associated to BLOCK.  Return NULL if block
 361    is NULL or if block is a global block.  */
 362
 363 const struct block *
 364 block_static_block (const struct block *block)
 365 {
 366   if (block == NULL || BLOCK_SUPERBLOCK (block) == NULL)
 367     return NULL;
 368
 369   while (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) != NULL)
 370     block = BLOCK_SUPERBLOCK (block);
 371
 372   return block;
 373 }
 374
 375 /* Return the static block associated to BLOCK.  Return NULL if block
 376    is NULL.  */
 377
 378 const struct block *
 379 block_global_block (const struct block *block)
 380 {
 381   if (block == NULL)
 382     return NULL;
 383
 384   while (BLOCK_SUPERBLOCK (block) != NULL)
 385     block = BLOCK_SUPERBLOCK (block);
 386
 387   return block;
 388 }
 389
 390 /* Allocate a block on OBSTACK, and initialize its elements to
 391    zero/NULL.  This is useful for creating "dummy" blocks that don't
 392    correspond to actual source files.
 393
 394    Warning: it sets the block's BLOCK_DICT to NULL, which isn't a
 395    valid value.  If you really don't want the block to have a
 396    dictionary, then you should subsequently set its BLOCK_DICT to
 397    dict_create_linear (obstack, NULL).  */
 398
 399 struct block *
 400 allocate_block (struct obstack *obstack)
 401 {
 402   struct block *bl = OBSTACK_ZALLOC (obstack, struct block);
 403
 404   return bl;
 405 }
 406
 407 /* Allocate a global block.  */
 408
 409 struct block *
 410 allocate_global_block (struct obstack *obstack)
 411 {
 412   struct global_block *bl = OBSTACK_ZALLOC (obstack, struct global_block);
 413
 414   return &bl->block;
 415 }
 416
 417 /* Set the compunit of the global block.  */
 418
 419 void
 420 set_block_compunit_symtab (struct block *block, struct compunit_symtab *cu)
 421 {
 422   struct global_block *gb;
 423
 424   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
 425   gb = (struct global_block *) block;
 426   gdb_assert (gb->compunit_symtab == NULL);
 427   gb->compunit_symtab = cu;
 428 }
 429
 430 /* See block.h.  */
 431
 432 struct dynamic_prop *
 433 block_static_link (const struct block *block)
 434 {
 435   struct objfile *objfile = block_objfile (block);
 436
 437   /* Only objfile-owned blocks that materialize top function scopes can have
 438      static links.  */
 439   if (objfile == NULL || BLOCK_FUNCTION (block) == NULL)
 440     return NULL;
 441
 442   return (struct dynamic_prop *) objfile_lookup_static_link (objfile, block);
 443 }
 444
 445 /* Return the compunit of the global block.  */
 446
 447 static struct compunit_symtab *
 448 get_block_compunit_symtab (const struct block *block)
 449 {
 450   struct global_block *gb;
 451
 452   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL);
 453   gb = (struct global_block *) block;
 454   gdb_assert (gb->compunit_symtab != NULL);
 455   return gb->compunit_symtab;
 456 }
 457
 458 \f
 459
 460 /* Initialize a block iterator, either to iterate over a single block,
 461    or, for static and global blocks, all the included symtabs as
 462    well.  */
 463
 464 static void
 465 initialize_block_iterator (const struct block *block,
 466                            struct block_iterator *iter)
 467 {
 468   enum block_enum which;
 469   struct compunit_symtab *cu;
 470
 471   iter->idx = -1;
 472
 473   if (BLOCK_SUPERBLOCK (block) == NULL)
 474     {
 475       which = GLOBAL_BLOCK;
 476       cu = get_block_compunit_symtab (block);
 477     }
 478   else if (BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL)
 479     {
 480       which = STATIC_BLOCK;
 481       cu = get_block_compunit_symtab (BLOCK_SUPERBLOCK (block));
 482     }
 483   else
 484     {
 485       iter->d.block = block;
 486       /* A signal value meaning that we're iterating over a single
 487          block.  */
 488       iter->which = FIRST_LOCAL_BLOCK;
 489       return;
 490     }
 491
 492   /* If this is an included symtab, find the canonical includer and
 493      use it instead.  */
 494   while (cu->user != NULL)
 495     cu = cu->user;
 496
 497   /* Putting this check here simplifies the logic of the iterator
 498      functions.  If there are no included symtabs, we only need to
 499      search a single block, so we might as well just do that
 500      directly.  */
 501   if (cu->includes == NULL)
 502     {
 503       iter->d.block = block;
 504       /* A signal value meaning that we're iterating over a single
 505          block.  */
 506       iter->which = FIRST_LOCAL_BLOCK;
 507     }
 508   else
 509     {
 510       iter->d.compunit_symtab = cu;
 511       iter->which = which;
 512     }
 513 }
 514
 515 /* A helper function that finds the current compunit over whose static
 516    or global block we should iterate.  */
 517
 518 static struct compunit_symtab *
 519 find_iterator_compunit_symtab (struct block_iterator *iterator)
 520 {
 521   if (iterator->idx == -1)
 522     return iterator->d.compunit_symtab;
 523   return iterator->d.compunit_symtab->includes[iterator->idx];
 524 }
 525
 526 /* Perform a single step for a plain block iterator, iterating across
 527    symbol tables as needed.  Returns the next symbol, or NULL when
 528    iteration is complete.  */
 529
 530 static struct symbol *
 531 block_iterator_step (struct block_iterator *iterator, int first)
 532 {
 533   struct symbol *sym;
 534
 535   gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
 536
 537   while (1)
 538     {
 539       if (first)
 540         {
 541           struct compunit_symtab *cust
 542             = find_iterator_compunit_symtab (iterator);
 543           const struct block *block;
 544
 545           /* Iteration is complete.  */
 546           if (cust == NULL)
 547             return  NULL;
 548
 549           block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
 550                                      iterator->which);
 551           sym = dict_iterator_first (BLOCK_DICT (block), &iterator->dict_iter);
 552         }
 553       else
 554         sym = dict_iterator_next (&iterator->dict_iter);
 555
 556       if (sym != NULL)
 557         return sym;
 558
 559       /* We have finished iterating the appropriate block of one
 560          symtab.  Now advance to the next symtab and begin iteration
 561          there.  */
 562       ++iterator->idx;
 563       first = 1;
 564     }
 565 }
 566
 567 /* See block.h.  */
 568
 569 struct symbol *
 570 block_iterator_first (const struct block *block,
 571                       struct block_iterator *iterator)
 572 {
 573   initialize_block_iterator (block, iterator);
 574
 575   if (iterator->which == FIRST_LOCAL_BLOCK)
 576     return dict_iterator_first (block->dict, &iterator->dict_iter);
 577
 578   return block_iterator_step (iterator, 1);
 579 }
 580
 581 /* See block.h.  */
 582
 583 struct symbol *
 584 block_iterator_next (struct block_iterator *iterator)
 585 {
 586   if (iterator->which == FIRST_LOCAL_BLOCK)
 587     return dict_iterator_next (&iterator->dict_iter);
 588
 589   return block_iterator_step (iterator, 0);
 590 }
 591
 592 /* Perform a single step for a "name" block iterator, iterating across
 593    symbol tables as needed.  Returns the next symbol, or NULL when
 594    iteration is complete.  */
 595
 596 static struct symbol *
 597 block_iter_name_step (struct block_iterator *iterator, const char *name,
 598                       int first)
 599 {
 600   struct symbol *sym;
 601
 602   gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
 603
 604   while (1)
 605     {
 606       if (first)
 607         {
 608           struct compunit_symtab *cust
 609             = find_iterator_compunit_symtab (iterator);
 610           const struct block *block;
 611
 612           /* Iteration is complete.  */
 613           if (cust == NULL)
 614             return  NULL;
 615
 616           block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
 617                                      iterator->which);
 618           sym = dict_iter_name_first (BLOCK_DICT (block), name,
 619                                       &iterator->dict_iter);
 620         }
 621       else
 622         sym = dict_iter_name_next (name, &iterator->dict_iter);
 623
 624       if (sym != NULL)
 625         return sym;
 626
 627       /* We have finished iterating the appropriate block of one
 628          symtab.  Now advance to the next symtab and begin iteration
 629          there.  */
 630       ++iterator->idx;
 631       first = 1;
 632     }
 633 }
 634
 635 /* See block.h.  */
 636
 637 struct symbol *
 638 block_iter_name_first (const struct block *block,
 639                        const char *name,
 640                        struct block_iterator *iterator)
 641 {
 642   initialize_block_iterator (block, iterator);
 643
 644   if (iterator->which == FIRST_LOCAL_BLOCK)
 645     return dict_iter_name_first (block->dict, name, &iterator->dict_iter);
 646
 647   return block_iter_name_step (iterator, name, 1);
 648 }
 649
 650 /* See block.h.  */
 651
 652 struct symbol *
 653 block_iter_name_next (const char *name, struct block_iterator *iterator)
 654 {
 655   if (iterator->which == FIRST_LOCAL_BLOCK)
 656     return dict_iter_name_next (name, &iterator->dict_iter);
 657
 658   return block_iter_name_step (iterator, name, 0);
 659 }
 660
 661 /* Perform a single step for a "match" block iterator, iterating
 662    across symbol tables as needed.  Returns the next symbol, or NULL
 663    when iteration is complete.  */
 664
 665 static struct symbol *
 666 block_iter_match_step (struct block_iterator *iterator,
 667                        const char *name,
 668                        symbol_compare_ftype *compare,
 669                        int first)
 670 {
 671   struct symbol *sym;
 672
 673   gdb_assert (iterator->which != FIRST_LOCAL_BLOCK);
 674
 675   while (1)
 676     {
 677       if (first)
 678         {
 679           struct compunit_symtab *cust
 680             = find_iterator_compunit_symtab (iterator);
 681           const struct block *block;
 682
 683           /* Iteration is complete.  */
 684           if (cust == NULL)
 685             return  NULL;
 686
 687           block = BLOCKVECTOR_BLOCK (COMPUNIT_BLOCKVECTOR (cust),
 688                                      iterator->which);
 689           sym = dict_iter_match_first (BLOCK_DICT (block), name,
 690                                        compare, &iterator->dict_iter);
 691         }
 692       else
 693         sym = dict_iter_match_next (name, compare, &iterator->dict_iter);
 694
 695       if (sym != NULL)
 696         return sym;
 697
 698       /* We have finished iterating the appropriate block of one
 699          symtab.  Now advance to the next symtab and begin iteration
 700          there.  */
 701       ++iterator->idx;
 702       first = 1;
 703     }
 704 }
 705
 706 /* See block.h.  */
 707
 708 struct symbol *
 709 block_iter_match_first (const struct block *block,
 710                         const char *name,
 711                         symbol_compare_ftype *compare,
 712                         struct block_iterator *iterator)
 713 {
 714   initialize_block_iterator (block, iterator);
 715
 716   if (iterator->which == FIRST_LOCAL_BLOCK)
 717     return dict_iter_match_first (block->dict, name, compare,
 718                                   &iterator->dict_iter);
 719
 720   return block_iter_match_step (iterator, name, compare, 1);
 721 }
 722
 723 /* See block.h.  */
 724
 725 struct symbol *
 726 block_iter_match_next (const char *name,
 727                        symbol_compare_ftype *compare,
 728                        struct block_iterator *iterator)
 729 {
 730   if (iterator->which == FIRST_LOCAL_BLOCK)
 731     return dict_iter_match_next (name, compare, &iterator->dict_iter);
 732
 733   return block_iter_match_step (iterator, name, compare, 0);
 734 }
 735
 736 /* See block.h.
 737
 738    Note that if NAME is the demangled form of a C++ symbol, we will fail
 739    to find a match during the binary search of the non-encoded names, but
 740    for now we don't worry about the slight inefficiency of looking for
 741    a match we'll never find, since it will go pretty quick.  Once the
 742    binary search terminates, we drop through and do a straight linear
 743    search on the symbols.  Each symbol which is marked as being a ObjC/C++
 744    symbol (language_cplus or language_objc set) has both the encoded and
 745    non-encoded names tested for a match.  */
 746
 747 struct symbol *
 748 block_lookup_symbol (const struct block *block, const char *name,
 749                      const domain_enum domain)
 750 {
 751   struct block_iterator iter;
 752   struct symbol *sym;
 753
 754   if (!BLOCK_FUNCTION (block))
 755     {
 756       struct symbol *other = NULL;
 757
 758       ALL_BLOCK_SYMBOLS_WITH_NAME (block, name, iter, sym)
 759         {
 760           if (SYMBOL_DOMAIN (sym) == domain)
 761             return sym;
 762           /* This is a bit of a hack, but symbol_matches_domain might ignore
 763              STRUCT vs VAR domain symbols.  So if a matching symbol is found,
 764              make sure there is no "better" matching symbol, i.e., one with
 765              exactly the same domain.  PR 16253.  */
 766           if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 767                                      SYMBOL_DOMAIN (sym), domain))
 768             other = sym;
 769         }
 770       return other;
 771     }
 772   else
 773     {
 774       /* Note that parameter symbols do not always show up last in the
 775          list; this loop makes sure to take anything else other than
 776          parameter symbols first; it only uses parameter symbols as a
 777          last resort.  Note that this only takes up extra computation
 778          time on a match.
 779          It's hard to define types in the parameter list (at least in
 780          C/C++) so we don't do the same PR 16253 hack here that is done
 781          for the !BLOCK_FUNCTION case.  */
 782
 783       struct symbol *sym_found = NULL;
 784
 785       ALL_BLOCK_SYMBOLS_WITH_NAME (block, name, iter, sym)
 786         {
 787           if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 788                                      SYMBOL_DOMAIN (sym), domain))
 789             {
 790               sym_found = sym;
 791               if (!SYMBOL_IS_ARGUMENT (sym))
 792                 {
 793                   break;
 794                 }
 795             }
 796         }
 797       return (sym_found);       /* Will be NULL if not found.  */
 798     }
 799 }
 800
 801 /* See block.h.  */
 802
 803 struct symbol *
 804 block_lookup_symbol_primary (const struct block *block, const char *name,
 805                              const domain_enum domain)
 806 {
 807   struct symbol *sym, *other;
 808   struct dict_iterator dict_iter;
 809
 810   /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK.  */
 811   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
 812               || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
 813
 814   other = NULL;
 815   for (sym = dict_iter_name_first (block->dict, name, &dict_iter);
 816        sym != NULL;
 817        sym = dict_iter_name_next (name, &dict_iter))
 818     {
 819       if (SYMBOL_DOMAIN (sym) == domain)
 820         return sym;
 821
 822       /* This is a bit of a hack, but symbol_matches_domain might ignore
 823          STRUCT vs VAR domain symbols.  So if a matching symbol is found,
 824          make sure there is no "better" matching symbol, i.e., one with
 825          exactly the same domain.  PR 16253.  */
 826       if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 827                                  SYMBOL_DOMAIN (sym), domain))
 828         other = sym;
 829     }
 830
 831   return other;
 832 }
 833
 834 /* See block.h.  */
 835
 836 struct symbol *
 837 block_find_symbol (const struct block *block, const char *name,
 838                    const domain_enum domain,
 839                    block_symbol_matcher_ftype *matcher, void *data)
 840 {
 841   struct block_iterator iter;
 842   struct symbol *sym;
 843
 844   /* Verify BLOCK is STATIC_BLOCK or GLOBAL_BLOCK.  */
 845   gdb_assert (BLOCK_SUPERBLOCK (block) == NULL
 846               || BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL);
 847
 848   ALL_BLOCK_SYMBOLS_WITH_NAME (block, name, iter, sym)
 849     {
 850       /* MATCHER is deliberately called second here so that it never sees
 851          a non-domain-matching symbol.  */
 852       if (symbol_matches_domain (SYMBOL_LANGUAGE (sym),
 853                                  SYMBOL_DOMAIN (sym), domain)
 854           && matcher (sym, data))
 855         return sym;
 856     }
 857   return NULL;
 858 }
 859
 860 /* See block.h.  */
 861
 862 int
 863 block_find_non_opaque_type (struct symbol *sym, void *data)
 864 {
 865   return !TYPE_IS_OPAQUE (SYMBOL_TYPE (sym));
 866 }
 867
 868 /* See block.h.  */
 869
 870 int
 871 block_find_non_opaque_type_preferred (struct symbol *sym, void *data)
 872 {
 873   struct symbol **best = (struct symbol **) data;
 874
 875   if (!TYPE_IS_OPAQUE (SYMBOL_TYPE (sym)))
 876     return 1;
 877   *best = sym;
 878   return 0;
 879 }