gdb/buildsym.c

   1 /* Support routines for building symbol tables in GDB's internal format.
   2    Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992
   3              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 2 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, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 /* This module provides subroutines used for creating and adding to
  22    the symbol table.  These routines are called from various symbol-
  23    file-reading routines.
  24
  25    Routines to support specific debugging information formats (stabs,
  26    DWARF, etc) belong somewhere else. */
  27
  28 #include "defs.h"
  29 #include "bfd.h"
  30 #include "obstack.h"
  31 #include "symtab.h"
  32 #include "symfile.h"            /* Needed for "struct complaint" */
  33 #include "objfiles.h"
  34 #include "complaints.h"
  35 #include <string.h>
  36
  37 /* Ask buildsym.h to define the vars it normally declares `extern'.  */
  38 #define EXTERN  /**/
  39 #include "buildsym.h"           /* Our own declarations */
  40 #undef  EXTERN
  41
  42 static int
  43 compare_line_numbers PARAMS ((const void *, const void *));
  44
  45 static struct blockvector *
  46 make_blockvector PARAMS ((struct objfile *));
  47
  48 \f
  49 /* Initial sizes of data structures.  These are realloc'd larger if needed,
  50    and realloc'd down to the size actually used, when completed.  */
  51
  52 #define INITIAL_CONTEXT_STACK_SIZE      10
  53 #define INITIAL_LINE_VECTOR_LENGTH      1000
  54
  55 \f
  56 /* Complaints about the symbols we have encountered.  */
  57
  58 struct complaint innerblock_complaint =
  59   {"inner block not inside outer block in %s", 0, 0};
  60
  61 struct complaint innerblock_anon_complaint =
  62   {"inner block not inside outer block", 0, 0};
  63
  64 struct complaint blockvector_complaint =
  65   {"block at 0x%x out of order", 0, 0};
  66
  67 \f
  68 /* maintain the lists of symbols and blocks */
  69
  70 /* Add a symbol to one of the lists of symbols.  */
  71
  72 void
  73 add_symbol_to_list (symbol, listhead)
  74      struct symbol *symbol;
  75      struct pending **listhead;
  76 {
  77   register struct pending *link;
  78
  79   /* We keep PENDINGSIZE symbols in each link of the list.
  80      If we don't have a link with room in it, add a new link.  */
  81   if (*listhead == NULL || (*listhead)->nsyms == PENDINGSIZE)
  82     {
  83       if (free_pendings)
  84         {
  85           link = free_pendings;
  86           free_pendings = link->next;
  87         }
  88       else
  89         {
  90           link = (struct pending *) xmalloc (sizeof (struct pending));
  91         }
  92
  93       link->next = *listhead;
  94       *listhead = link;
  95       link->nsyms = 0;
  96     }
  97
  98   (*listhead)->symbol[(*listhead)->nsyms++] = symbol;
  99 }
 100
 101 /* Find a symbol on a pending list.  */
 102
 103 struct symbol *
 104 find_symbol_in_list (list, name, length)
 105      struct pending *list;
 106      char *name;
 107      int length;
 108 {
 109   int j;
 110   char *pp;
 111
 112   while (list != NULL)
 113     {
 114       for (j = list->nsyms; --j >= 0; )
 115         {
 116           pp = SYMBOL_NAME (list->symbol[j]);
 117           if (*pp == *name && strncmp (pp, name, length) == 0 &&
 118               pp[length] == '\0')
 119             {
 120               return (list->symbol[j]);
 121             }
 122         }
 123       list = list->next;
 124     }
 125   return (NULL);
 126 }
 127
 128 /* At end of reading syms, or in case of quit,
 129    really free as many `struct pending's as we can easily find. */
 130
 131 /* ARGSUSED */
 132 void
 133 really_free_pendings (foo)
 134      int foo;
 135 {
 136   struct pending *next, *next1;
 137 #if 0
 138   struct pending_block *bnext, *bnext1;
 139 #endif
 140
 141   for (next = free_pendings; next; next = next1)
 142     {
 143       next1 = next->next;
 144       free ((PTR)next);
 145     }
 146   free_pendings = NULL;
 147
 148 #if 0 /* Now we make the links in the symbol_obstack, so don't free them.  */
 149   for (bnext = pending_blocks; bnext; bnext = bnext1)
 150     {
 151       bnext1 = bnext->next;
 152       free ((PTR)bnext);
 153     }
 154 #endif
 155   pending_blocks = NULL;
 156
 157   for (next = file_symbols; next != NULL; next = next1)
 158     {
 159       next1 = next->next;
 160       free ((PTR)next);
 161     }
 162   file_symbols = NULL;
 163
 164   for (next = global_symbols; next != NULL; next = next1)
 165     {
 166       next1 = next->next;
 167       free ((PTR)next);
 168     }
 169   global_symbols = NULL;
 170 }
 171
 172 /* Take one of the lists of symbols and make a block from it.
 173    Keep the order the symbols have in the list (reversed from the input file).
 174    Put the block on the list of pending blocks.  */
 175
 176 void
 177 finish_block (symbol, listhead, old_blocks, start, end, objfile)
 178      struct symbol *symbol;
 179      struct pending **listhead;
 180      struct pending_block *old_blocks;
 181      CORE_ADDR start, end;
 182      struct objfile *objfile;
 183 {
 184   register struct pending *next, *next1;
 185   register struct block *block;
 186   register struct pending_block *pblock;
 187   struct pending_block *opblock;
 188   register int i;
 189   register int j;
 190
 191   /* Count the length of the list of symbols.  */
 192
 193   for (next = *listhead, i = 0;
 194        next;
 195        i += next->nsyms, next = next->next)
 196     {
 197       /*EMPTY*/;
 198     }
 199
 200   block = (struct block *) obstack_alloc (&objfile -> symbol_obstack,
 201           (sizeof (struct block) + ((i - 1) * sizeof (struct symbol *))));
 202
 203   /* Copy the symbols into the block.  */
 204
 205   BLOCK_NSYMS (block) = i;
 206   for (next = *listhead; next; next = next->next)
 207     {
 208       for (j = next->nsyms - 1; j >= 0; j--)
 209         {
 210           BLOCK_SYM (block, --i) = next->symbol[j];
 211         }
 212     }
 213
 214   BLOCK_START (block) = start;
 215   BLOCK_END (block) = end;
 216  /* Superblock filled in when containing block is made */
 217   BLOCK_SUPERBLOCK (block) = NULL;
 218   BLOCK_GCC_COMPILED (block) = processing_gcc_compilation;
 219
 220   /* Put the block in as the value of the symbol that names it.  */
 221
 222   if (symbol)
 223     {
 224       SYMBOL_BLOCK_VALUE (symbol) = block;
 225       BLOCK_FUNCTION (block) = symbol;
 226     }
 227   else
 228     {
 229       BLOCK_FUNCTION (block) = NULL;
 230     }
 231
 232   /* Now "free" the links of the list, and empty the list.  */
 233
 234   for (next = *listhead; next; next = next1)
 235     {
 236       next1 = next->next;
 237       next->next = free_pendings;
 238       free_pendings = next;
 239     }
 240   *listhead = NULL;
 241
 242   /* Install this block as the superblock
 243      of all blocks made since the start of this scope
 244      that don't have superblocks yet.  */
 245
 246   opblock = NULL;
 247   for (pblock = pending_blocks; pblock != old_blocks; pblock = pblock->next)
 248     {
 249       if (BLOCK_SUPERBLOCK (pblock->block) == NULL)
 250         {
 251 #if 1
 252           /* Check to be sure the blocks are nested as we receive them.
 253              If the compiler/assembler/linker work, this just burns a small
 254              amount of time.  */
 255           if (BLOCK_START (pblock->block) < BLOCK_START (block) ||
 256               BLOCK_END   (pblock->block) > BLOCK_END   (block))
 257             {
 258               if (symbol)
 259                 {
 260                   complain (&innerblock_complaint,
 261                             SYMBOL_SOURCE_NAME (symbol));
 262                 }
 263               else
 264                 {
 265                   complain (&innerblock_anon_complaint);
 266                 }
 267               BLOCK_START (pblock->block) = BLOCK_START (block);
 268               BLOCK_END   (pblock->block) = BLOCK_END   (block);
 269             }
 270 #endif
 271           BLOCK_SUPERBLOCK (pblock->block) = block;
 272         }
 273       opblock = pblock;
 274     }
 275
 276   /* Record this block on the list of all blocks in the file.
 277      Put it after opblock, or at the beginning if opblock is 0.
 278      This puts the block in the list after all its subblocks.  */
 279
 280   /* Allocate in the symbol_obstack to save time.
 281      It wastes a little space.  */
 282   pblock = (struct pending_block *)
 283     obstack_alloc (&objfile -> symbol_obstack,
 284                    sizeof (struct pending_block));
 285   pblock->block = block;
 286   if (opblock)
 287     {
 288       pblock->next = opblock->next;
 289       opblock->next = pblock;
 290     }
 291   else
 292     {
 293       pblock->next = pending_blocks;
 294       pending_blocks = pblock;
 295     }
 296 }
 297
 298 static struct blockvector *
 299 make_blockvector (objfile)
 300       struct objfile *objfile;
 301 {
 302   register struct pending_block *next;
 303   register struct blockvector *blockvector;
 304   register int i;
 305
 306   /* Count the length of the list of blocks.  */
 307
 308   for (next = pending_blocks, i = 0; next; next = next->next, i++) {;}
 309
 310   blockvector = (struct blockvector *)
 311     obstack_alloc (&objfile -> symbol_obstack,
 312                    (sizeof (struct blockvector)
 313                     + (i - 1) * sizeof (struct block *)));
 314
 315   /* Copy the blocks into the blockvector.
 316      This is done in reverse order, which happens to put
 317      the blocks into the proper order (ascending starting address).
 318      finish_block has hair to insert each block into the list
 319      after its subblocks in order to make sure this is true.  */
 320
 321   BLOCKVECTOR_NBLOCKS (blockvector) = i;
 322   for (next = pending_blocks; next; next = next->next)
 323     {
 324       BLOCKVECTOR_BLOCK (blockvector, --i) = next->block;
 325     }
 326
 327 #if 0 /* Now we make the links in the obstack, so don't free them.  */
 328   /* Now free the links of the list, and empty the list.  */
 329
 330   for (next = pending_blocks; next; next = next1)
 331     {
 332       next1 = next->next;
 333       free (next);
 334     }
 335 #endif
 336   pending_blocks = NULL;
 337
 338 #if 1  /* FIXME, shut this off after a while to speed up symbol reading.  */
 339   /* Some compilers output blocks in the wrong order, but we depend
 340      on their being in the right order so we can binary search.
 341      Check the order and moan about it.  FIXME.  */
 342   if (BLOCKVECTOR_NBLOCKS (blockvector) > 1)
 343     {
 344       for (i = 1; i < BLOCKVECTOR_NBLOCKS (blockvector); i++)
 345         {
 346           if (BLOCK_START(BLOCKVECTOR_BLOCK (blockvector, i-1))
 347               > BLOCK_START(BLOCKVECTOR_BLOCK (blockvector, i)))
 348             {
 349               complain (&blockvector_complaint,
 350                         BLOCK_START(BLOCKVECTOR_BLOCK (blockvector, i)));
 351             }
 352         }
 353     }
 354 #endif
 355
 356   return (blockvector);
 357 }
 358
 359 \f
 360 /* Start recording information about source code that came from an included
 361    (or otherwise merged-in) source file with a different name.  */
 362
 363 void
 364 start_subfile (name, dirname)
 365      char *name;
 366      char *dirname;
 367 {
 368   register struct subfile *subfile;
 369
 370   /* See if this subfile is already known as a subfile of the
 371      current main source file.  */
 372
 373   for (subfile = subfiles; subfile; subfile = subfile->next)
 374     {
 375       if (STREQ (subfile->name, name))
 376         {
 377           current_subfile = subfile;
 378           return;
 379         }
 380     }
 381
 382   /* This subfile is not known.  Add an entry for it.
 383      Make an entry for this subfile in the list of all subfiles
 384      of the current main source file.  */
 385
 386   subfile = (struct subfile *) xmalloc (sizeof (struct subfile));
 387   subfile->next = subfiles;
 388   subfiles = subfile;
 389   current_subfile = subfile;
 390
 391   /* Save its name and compilation directory name */
 392   subfile->name = (name == NULL)? NULL : strdup (name);
 393   subfile->dirname = (dirname == NULL) ? NULL : strdup (dirname);
 394
 395   /* Initialize line-number recording for this subfile.  */
 396   subfile->line_vector = NULL;
 397
 398   /* Default the source language to whatever can be deduced from
 399      the filename.  If nothing can be deduced (such as for a C/C++
 400      include file with a ".h" extension), then inherit whatever
 401      language the previous subfile had.  This kludgery is necessary
 402      because there is no standard way in some object formats to
 403      record the source language.  Also, when symtabs are allocated
 404      we try to deduce a language then as well, but it is too late
 405      for us to use that information while reading symbols, since
 406      symtabs aren't allocated until after all the symbols have
 407      been processed for a given source file. */
 408
 409   subfile->language = deduce_language_from_filename (subfile->name);
 410   if (subfile->language == language_unknown &&
 411       subfile->next != NULL)
 412     {
 413       subfile->language = subfile->next->language;
 414     }
 415 }
 416
 417 /* For stabs readers, the first N_SO symbol is assumed to be the source
 418    file name, and the subfile struct is initialized using that assumption.
 419    If another N_SO symbol is later seen, immediately following the first
 420    one, then the first one is assumed to be the directory name and the
 421    second one is really the source file name.
 422
 423    So we have to patch up the subfile struct by moving the old name value to
 424    dirname and remembering the new name.  Some sanity checking is performed
 425    to ensure that the state of the subfile struct is reasonable and that the
 426    old name we are assuming to be a directory name actually is (by checking
 427    for a trailing '/'). */
 428
 429 void
 430 patch_subfile_names (subfile, name)
 431      struct subfile *subfile;
 432      char *name;
 433 {
 434   if (subfile != NULL && subfile->dirname == NULL && subfile->name != NULL
 435       && subfile->name[strlen(subfile->name)-1] == '/')
 436     {
 437       subfile->dirname = subfile->name;
 438       subfile->name = strdup (name);
 439
 440       /* Default the source language to whatever can be deduced from
 441          the filename.  If nothing can be deduced (such as for a C/C++
 442          include file with a ".h" extension), then inherit whatever
 443          language the previous subfile had.  This kludgery is necessary
 444          because there is no standard way in some object formats to
 445          record the source language.  Also, when symtabs are allocated
 446          we try to deduce a language then as well, but it is too late
 447          for us to use that information while reading symbols, since
 448          symtabs aren't allocated until after all the symbols have
 449          been processed for a given source file. */
 450
 451       subfile->language = deduce_language_from_filename (subfile->name);
 452       if (subfile->language == language_unknown &&
 453           subfile->next != NULL)
 454         {
 455           subfile->language = subfile->next->language;
 456         }
 457     }
 458 }
 459
 460 \f
 461 /* Handle the N_BINCL and N_EINCL symbol types
 462    that act like N_SOL for switching source files
 463    (different subfiles, as we call them) within one object file,
 464    but using a stack rather than in an arbitrary order.  */
 465
 466 void
 467 push_subfile ()
 468 {
 469   register struct subfile_stack *tem
 470     = (struct subfile_stack *) xmalloc (sizeof (struct subfile_stack));
 471
 472   tem->next = subfile_stack;
 473   subfile_stack = tem;
 474   if (current_subfile == NULL || current_subfile->name == NULL)
 475     {
 476       abort ();
 477     }
 478   tem->name = current_subfile->name;
 479 }
 480
 481 char *
 482 pop_subfile ()
 483 {
 484   register char *name;
 485   register struct subfile_stack *link = subfile_stack;
 486
 487   if (link == NULL)
 488     {
 489       abort ();
 490     }
 491   name = link->name;
 492   subfile_stack = link->next;
 493   free ((PTR)link);
 494   return (name);
 495 }
 496
 497 \f
 498 /* Manage the vector of line numbers for each subfile.  */
 499
 500 void
 501 record_line (subfile, line, pc)
 502      register struct subfile *subfile;
 503      int line;
 504      CORE_ADDR pc;
 505 {
 506   struct linetable_entry *e;
 507   /* Ignore the dummy line number in libg.o */
 508
 509   if (line == 0xffff)
 510     {
 511       return;
 512     }
 513
 514   /* Make sure line vector exists and is big enough.  */
 515   if (!subfile->line_vector)
 516     {
 517       subfile->line_vector_length = INITIAL_LINE_VECTOR_LENGTH;
 518       subfile->line_vector = (struct linetable *)
 519         xmalloc (sizeof (struct linetable)
 520           + subfile->line_vector_length * sizeof (struct linetable_entry));
 521       subfile->line_vector->nitems = 0;
 522     }
 523
 524   if (subfile->line_vector->nitems + 1 >= subfile->line_vector_length)
 525     {
 526       subfile->line_vector_length *= 2;
 527       subfile->line_vector = (struct linetable *)
 528         xrealloc ((char *) subfile->line_vector, (sizeof (struct linetable)
 529           + subfile->line_vector_length * sizeof (struct linetable_entry)));
 530     }
 531
 532   e = subfile->line_vector->item + subfile->line_vector->nitems++;
 533   e->line = line; e->pc = pc;
 534 }
 535
 536
 537 /* Needed in order to sort line tables from IBM xcoff files.  Sigh!  */
 538
 539 static int
 540 compare_line_numbers (ln1p, ln2p)
 541      const PTR ln1p;
 542      const PTR ln2p;
 543 {
 544   return (((struct linetable_entry *) ln1p) -> line -
 545           ((struct linetable_entry *) ln2p) -> line);
 546 }
 547
 548 \f
 549 /* Start a new symtab for a new source file.
 550    Called, for example, when a stabs symbol of type N_SO is seen, or when
 551    a DWARF TAG_compile_unit DIE is seen.
 552    It indicates the start of data for one original source file.  */
 553
 554 void
 555 start_symtab (name, dirname, start_addr)
 556      char *name;
 557      char *dirname;
 558      CORE_ADDR start_addr;
 559 {
 560
 561   last_source_file = name;
 562   last_source_start_addr = start_addr;
 563   file_symbols = NULL;
 564   global_symbols = NULL;
 565   within_function = 0;
 566
 567   /* Context stack is initially empty.  Allocate first one with room for
 568      10 levels; reuse it forever afterward.  */
 569   if (context_stack == NULL)
 570     {
 571       context_stack_size = INITIAL_CONTEXT_STACK_SIZE;
 572       context_stack = (struct context_stack *)
 573         xmalloc (context_stack_size * sizeof (struct context_stack));
 574     }
 575   context_stack_depth = 0;
 576
 577   /* Initialize the list of sub source files with one entry
 578      for this file (the top-level source file).  */
 579
 580   subfiles = NULL;
 581   current_subfile = NULL;
 582   start_subfile (name, dirname);
 583 }
 584
 585 /* Finish the symbol definitions for one main source file,
 586    close off all the lexical contexts for that file
 587    (creating struct block's for them), then make the struct symtab
 588    for that file and put it in the list of all such.
 589
 590    END_ADDR is the address of the end of the file's text.
 591    SECTION is the section number (in objfile->section_offsets) of
 592    the blockvector and linetable.
 593
 594    Note that it is possible for end_symtab() to return NULL.  In particular,
 595    for the DWARF case at least, it will return NULL when it finds a
 596    compilation unit that has exactly one DIE, a TAG_compile_unit DIE.  This
 597    can happen when we link in an object file that was compiled from an empty
 598    source file.  Returning NULL is probably not the correct thing to do,
 599    because then gdb will never know about this empty file (FIXME). */
 600
 601 struct symtab *
 602 end_symtab (end_addr, sort_pending, sort_linevec, objfile, section)
 603      CORE_ADDR end_addr;
 604      int sort_pending;
 605      int sort_linevec;
 606      struct objfile *objfile;
 607      int section;
 608 {
 609   register struct symtab *symtab;
 610   register struct blockvector *blockvector;
 611   register struct subfile *subfile;
 612   register struct context_stack *cstk;
 613   struct subfile *nextsub;
 614
 615   /* Finish the lexical context of the last function in the file;
 616      pop the context stack.  */
 617
 618   if (context_stack_depth > 0)
 619     {
 620       context_stack_depth--;
 621       cstk = &context_stack[context_stack_depth];
 622       /* Make a block for the local symbols within.  */
 623       finish_block (cstk->name, &local_symbols, cstk->old_blocks,
 624                     cstk->start_addr, end_addr, objfile);
 625
 626       /* Debug: if context stack still has something in it,
 627          we are in trouble.  */
 628       if (context_stack_depth > 0)
 629         {
 630           abort ();
 631         }
 632     }
 633
 634   /* It is unfortunate that in xcoff, pending blocks might not be ordered
 635      in this stage. Especially, blocks for static functions will show up at
 636      the end.  We need to sort them, so tools like `find_pc_function' and
 637      `find_pc_block' can work reliably. */
 638
 639   if (sort_pending && pending_blocks)
 640     {
 641       /* FIXME!  Remove this horrid bubble sort and use qsort!!! */
 642       int swapped;
 643       do
 644         {
 645           struct pending_block *pb, *pbnext;
 646
 647           pb = pending_blocks;
 648           pbnext = pb->next;
 649           swapped = 0;
 650
 651           while (pbnext)
 652             {
 653               /* swap blocks if unordered! */
 654
 655               if (BLOCK_START(pb->block) < BLOCK_START(pbnext->block))
 656                 {
 657                   struct block *tmp = pb->block;
 658                   pb->block = pbnext->block;
 659                   pbnext->block = tmp;
 660                   swapped = 1;
 661                 }
 662               pb = pbnext;
 663               pbnext = pbnext->next;
 664             }
 665         } while (swapped);
 666     }
 667
 668   /* Cleanup any undefined types that have been left hanging around
 669      (this needs to be done before the finish_blocks so that
 670      file_symbols is still good).
 671      FIXME:  Stabs specific. */
 672   cleanup_undefined_types ();
 673   finish_global_stabs (objfile);
 674
 675   if (pending_blocks == NULL
 676       && file_symbols == NULL
 677       && global_symbols == NULL)
 678     {
 679       /* Ignore symtabs that have no functions with real debugging info */
 680       blockvector = NULL;
 681     }
 682   else
 683     {
 684       /* Define the STATIC_BLOCK & GLOBAL_BLOCK, and build the blockvector. */
 685       finish_block (0, &file_symbols, 0, last_source_start_addr, end_addr,
 686                     objfile);
 687       finish_block (0, &global_symbols, 0, last_source_start_addr, end_addr,
 688                     objfile);
 689       blockvector = make_blockvector (objfile);
 690     }
 691
 692 #ifdef PROCESS_LINENUMBER_HOOK
 693   PROCESS_LINENUMBER_HOOK ();                   /* Needed for xcoff. */
 694 #endif
 695
 696   /* Now create the symtab objects proper, one for each subfile.  */
 697   /* (The main file is the last one on the chain.)  */
 698
 699   for (subfile = subfiles; subfile; subfile = nextsub)
 700     {
 701       int linetablesize;
 702       /* If we have blocks of symbols, make a symtab.
 703          Otherwise, just ignore this file and any line number info in it.  */
 704       symtab = NULL;
 705       if (blockvector)
 706         {
 707           if (subfile->line_vector)
 708             {
 709               /* First, shrink the linetable to make more memory.  */
 710               linetablesize = sizeof (struct linetable) +
 711                 subfile->line_vector->nitems * sizeof (struct linetable_entry);
 712               subfile->line_vector = (struct linetable *)
 713                 xrealloc ((char *) subfile->line_vector, linetablesize);
 714
 715               if (sort_linevec)
 716                 qsort (subfile->line_vector->item,
 717                        subfile->line_vector->nitems,
 718                        sizeof (struct linetable_entry), compare_line_numbers);
 719             }
 720
 721           /* Now, allocate a symbol table.  */
 722           symtab = allocate_symtab (subfile->name, objfile);
 723
 724           /* Fill in its components.  */
 725           symtab->blockvector = blockvector;
 726           if (subfile->line_vector)
 727             {
 728               /* Reallocate the line table on the symbol obstack */
 729               symtab->linetable = (struct linetable *)
 730                 obstack_alloc (&objfile -> symbol_obstack, linetablesize);
 731               memcpy (symtab->linetable, subfile->line_vector, linetablesize);
 732             }
 733           else
 734             {
 735               symtab->linetable = NULL;
 736             }
 737           symtab->block_line_section = section;
 738           if (subfile->dirname)
 739             {
 740               /* Reallocate the dirname on the symbol obstack */
 741               symtab->dirname = (char *)
 742                 obstack_alloc (&objfile -> symbol_obstack,
 743                                strlen (subfile -> dirname) + 1);
 744               strcpy (symtab->dirname, subfile->dirname);
 745             }
 746           else
 747             {
 748               symtab->dirname = NULL;
 749             }
 750           symtab->free_code = free_linetable;
 751           symtab->free_ptr = NULL;
 752
 753           /* Use whatever language we have been using for this subfile,
 754              not the one that was deduced in allocate_symtab from the
 755              filename.  We already did our own deducing when we created
 756              the subfile, and we may have altered our opinion of what
 757              language it is from things we found in the symbols. */
 758           symtab->language = subfile->language;
 759
 760           /* All symtabs for the main file and the subfiles share a
 761              blockvector, so we need to clear primary for everything but
 762              the main file.  */
 763
 764           symtab->primary = 0;
 765         }
 766       if (subfile->name != NULL)
 767         {
 768           free ((PTR) subfile->name);
 769         }
 770       if (subfile->dirname != NULL)
 771         {
 772           free ((PTR) subfile->dirname);
 773         }
 774       if (subfile->line_vector != NULL)
 775         {
 776           free ((PTR) subfile->line_vector);
 777         }
 778
 779       nextsub = subfile->next;
 780       free ((PTR)subfile);
 781     }
 782
 783   /* Set this for the main source file.  */
 784   if (symtab)
 785     {
 786       symtab->primary = 1;
 787     }
 788
 789   last_source_file = NULL;
 790   current_subfile = NULL;
 791
 792   return (symtab);
 793 }
 794
 795
 796 /* Push a context block.  Args are an identifying nesting level (checkable
 797    when you pop it), and the starting PC address of this context.  */
 798
 799 struct context_stack *
 800 push_context (desc, valu)
 801      int desc;
 802      CORE_ADDR valu;
 803 {
 804   register struct context_stack *new;
 805
 806   if (context_stack_depth == context_stack_size)
 807     {
 808       context_stack_size *= 2;
 809       context_stack = (struct context_stack *)
 810         xrealloc ((char *) context_stack,
 811                   (context_stack_size * sizeof (struct context_stack)));
 812     }
 813
 814   new = &context_stack[context_stack_depth++];
 815   new->depth = desc;
 816   new->locals = local_symbols;
 817   new->old_blocks = pending_blocks;
 818   new->start_addr = valu;
 819   new->name = NULL;
 820
 821   local_symbols = NULL;
 822
 823   return (new);
 824 }
 825
 826 \f
 827 /* Initialize anything that needs initializing when starting to read
 828    a fresh piece of a symbol file, e.g. reading in the stuff corresponding
 829    to a psymtab.  */
 830
 831 void
 832 buildsym_init ()
 833 {
 834   free_pendings = NULL;
 835   file_symbols = NULL;
 836   global_symbols = NULL;
 837   pending_blocks = NULL;
 838 }
 839
 840 /* Initialize anything that needs initializing when a completely new
 841    symbol file is specified (not just adding some symbols from another
 842    file, e.g. a shared library).  */
 843
 844 void
 845 buildsym_new_init ()
 846 {
 847   buildsym_init ();
 848 }
 849
 850 /* Initializer for this module */
 851
 852 void
 853 _initialize_buildsym ()
 854 {
 855 }