gdb/symfile.h

   1 /* Definitions for reading symbol files into GDB.
   2
   3    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   4    2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009, 2010
   5    Free Software Foundation, Inc.
   6
   7    This file is part of GDB.
   8
   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.
  13
  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.
  18
  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/>.  */
  21
  22 #if !defined (SYMFILE_H)
  23 #define SYMFILE_H
  24
  25 /* This file requires that you first include "bfd.h".  */
  26 #include "symtab.h"
  27
  28 /* Opaque declarations.  */
  29 struct target_section;
  30 struct objfile;
  31 struct obj_section;
  32 struct obstack;
  33 struct block;
  34
  35 /* Comparison function for symbol look ups.  */
  36
  37 typedef int (symbol_compare_ftype) (const char *string1,
  38                                     const char *string2);
  39
  40 /* Partial symbols are stored in the psymbol_cache and pointers to
  41    them are kept in a dynamically grown array that is obtained from
  42    malloc and grown as necessary via realloc.  Each objfile typically
  43    has two of these, one for global symbols and one for static
  44    symbols.  Although this adds a level of indirection for storing or
  45    accessing the partial symbols, it allows us to throw away duplicate
  46    psymbols and set all pointers to the single saved instance.  */
  47
  48 struct psymbol_allocation_list
  49 {
  50
  51   /* Pointer to beginning of dynamically allocated array of pointers
  52      to partial symbols.  The array is dynamically expanded as
  53      necessary to accommodate more pointers.  */
  54
  55   struct partial_symbol **list;
  56
  57   /* Pointer to next available slot in which to store a pointer to a
  58      partial symbol.  */
  59
  60   struct partial_symbol **next;
  61
  62   /* Number of allocated pointer slots in current dynamic array (not
  63      the number of bytes of storage).  The "next" pointer will always
  64      point somewhere between list[0] and list[size], and when at
  65      list[size] the array will be expanded on the next attempt to
  66      store a pointer.  */
  67
  68   int size;
  69 };
  70
  71 /* Define an array of addresses to accommodate non-contiguous dynamic
  72    loading of modules.  This is for use when entering commands, so we
  73    can keep track of the section names until we read the file and can
  74    map them to bfd sections.  This structure is also used by solib.c
  75    to communicate the section addresses in shared objects to
  76    symbol_file_add ().  */
  77
  78 struct section_addr_info
  79 {
  80   /* The number of sections for which address information is
  81      available.  */
  82   size_t num_sections;
  83   /* Sections whose names are file format dependent. */
  84   struct other_sections
  85   {
  86     CORE_ADDR addr;
  87     char *name;
  88
  89     /* SECTINDEX must be valid for associated BFD if ADDR is not zero.  */
  90     int sectindex;
  91   } other[1];
  92 };
  93
  94
  95 /* A table listing the load segments in a symfile, and which segment
  96    each BFD section belongs to.  */
  97 struct symfile_segment_data
  98 {
  99   /* How many segments are present in this file.  If there are
 100      two, the text segment is the first one and the data segment
 101      is the second one.  */
 102   int num_segments;
 103
 104   /* If NUM_SEGMENTS is greater than zero, the original base address
 105      of each segment.  */
 106   CORE_ADDR *segment_bases;
 107
 108   /* If NUM_SEGMENTS is greater than zero, the memory size of each
 109      segment.  */
 110   CORE_ADDR *segment_sizes;
 111
 112   /* If NUM_SEGMENTS is greater than zero, this is an array of entries
 113      recording which segment contains each BFD section.
 114      SEGMENT_INFO[I] is S+1 if the I'th BFD section belongs to segment
 115      S, or zero if it is not in any segment.  */
 116   int *segment_info;
 117 };
 118
 119 /* The "quick" symbol functions exist so that symbol readers can
 120    avoiding an initial read of all the symbols.  For example, symbol
 121    readers might choose to use the "partial symbol table" utilities,
 122    which is one implementation of the quick symbol functions.
 123
 124    The quick symbol functions are generally opaque: the underlying
 125    representation is hidden from the caller.
 126
 127    In general, these functions should only look at whatever special
 128    index the symbol reader creates -- looking through the symbol
 129    tables themselves is handled by generic code.  If a function is
 130    defined as returning a "symbol table", this means that the function
 131    should only return a newly-created symbol table; it should not
 132    examine pre-existing ones.
 133
 134    The exact list of functions here was determined in an ad hoc way
 135    based on gdb's history.  */
 136
 137 struct quick_symbol_functions
 138 {
 139   /* Return true if this objfile has any "partial" symbols
 140      available.  */
 141   int (*has_symbols) (struct objfile *objfile);
 142
 143   /* Return the symbol table for the "last" file appearing in
 144      OBJFILE.  */
 145   struct symtab *(*find_last_source_symtab) (struct objfile *objfile);
 146
 147   /* Forget all cached full file names for OBJFILE.  */
 148   void (*forget_cached_source_info) (struct objfile *objfile);
 149
 150   /* Look up the symbol table, in OBJFILE, of a source file named
 151      NAME.  If there is no '/' in the name, a match after a '/' in the
 152      symbol table's file name will also work.  FULL_PATH is the
 153      absolute file name, and REAL_PATH is the same, run through
 154      gdb_realpath.
 155
 156      If no such symbol table can be found, returns 0.
 157
 158      Otherwise, sets *RESULT to the symbol table and returns 1.  This
 159      might return 1 and set *RESULT to NULL if the requested file is
 160      an include file that does not have a symtab of its own.  */
 161   int (*lookup_symtab) (struct objfile *objfile,
 162                         const char *name,
 163                         const char *full_path,
 164                         const char *real_path,
 165                         struct symtab **result);
 166
 167   /* Check to see if the symbol is defined in a "partial" symbol table
 168      of OBJFILE.  KIND should be either GLOBAL_BLOCK or STATIC_BLOCK,
 169      depending on whether we want to search global symbols or static
 170      symbols.  NAME is the name of the symbol to look for.  DOMAIN
 171      indicates what sort of symbol to search for.
 172
 173      Returns the newly-expanded symbol table in which the symbol is
 174      defined, or NULL if no such symbol table exists.  */
 175   struct symtab *(*lookup_symbol) (struct objfile *objfile,
 176                                    int kind, const char *name,
 177                                    domain_enum domain);
 178
 179   /* This is called to expand symbol tables before looking up a
 180      symbol.  A backend can choose to implement this and then have its
 181      `lookup_symbol' hook always return NULL, or the reverse.  (It
 182      doesn't make sense to implement both.)  The arguments are as for
 183      `lookup_symbol'.  */
 184   void (*pre_expand_symtabs_matching) (struct objfile *objfile,
 185                                        int kind, const char *name,
 186                                        domain_enum domain);
 187
 188   /* Print statistics about any indices loaded for OBJFILE.  The
 189      statistics should be printed to gdb_stdout.  This is used for
 190      "maint print statistics".  */
 191   void (*print_stats) (struct objfile *objfile);
 192
 193   /* Dump any indices loaded for OBJFILE.  The dump should go to
 194      gdb_stdout.  This is used for "maint print objfiles".  */
 195   void (*dump) (struct objfile *objfile);
 196
 197   /* This is called by objfile_relocate to relocate any indices loaded
 198      for OBJFILE.  */
 199   void (*relocate) (struct objfile *objfile,
 200                     struct section_offsets *new_offsets,
 201                     struct section_offsets *delta);
 202
 203   /* Find all the symbols in OBJFILE named FUNC_NAME, and ensure that
 204      the corresponding symbol tables are loaded.  */
 205   void (*expand_symtabs_for_function) (struct objfile *objfile,
 206                                        const char *func_name);
 207
 208   /* Read all symbol tables associated with OBJFILE.  */
 209   void (*expand_all_symtabs) (struct objfile *objfile);
 210
 211   /* Read all symbol tables associated with OBJFILE which have the
 212      file name FILENAME.  */
 213   void (*expand_symtabs_with_filename) (struct objfile *objfile,
 214                                         const char *filename);
 215
 216   /* Return the file name of the file holding the symbol in OBJFILE
 217      named NAME.  If no such symbol exists in OBJFILE, return NULL.  */
 218   const char *(*find_symbol_file) (struct objfile *objfile, const char *name);
 219
 220   /* Find global or static symbols in all tables that are in NAMESPACE
 221      and for which MATCH (symbol name, NAME) == 0, passing each to
 222      CALLBACK, reading in partial symbol symbol tables as needed.  Look
 223      through global symbols if GLOBAL and otherwise static symbols.
 224      Passes NAME, NAMESPACE, and DATA to CALLBACK with each symbol
 225      found.  After each block is processed, passes NULL to CALLBACK.
 226      MATCH must be weaker than strcmp_iw in the sense that
 227      strcmp_iw(x,y) == 0 --> MATCH(x,y) == 0.  ORDERED_COMPARE, if
 228      non-null, must be an ordering relation compatible with strcmp_iw
 229      in the sense that
 230             strcmp(x,y) == 0 --> ORDERED_COMPARE(x,y) == 0
 231      and
 232             strcmp(x,y) <= 0 --> ORDERED_COMPARE(x,y) <= 0
 233      (allowing strcmp(x,y) < 0 while ORDERED_COMPARE(x, y) == 0).
 234      CALLBACK returns 0 to indicate that the scan should continue, or
 235      non-zero to indicate that the scan should be terminated.  */
 236
 237   void (*map_matching_symbols) (const char *name, domain_enum namespace,
 238                                 struct objfile *, int global,
 239                                 int (*callback) (struct block *,
 240                                                  struct symbol *, void *),
 241                                 void *data,
 242                                 symbol_compare_ftype *match,
 243                                 symbol_compare_ftype *ordered_compare);
 244
 245   /* Expand all symbol tables in OBJFILE matching some criteria.
 246
 247      FILE_MATCHER is called for each file in OBJFILE.  The file name
 248      and the DATA argument are passed to it.  If it returns zero, this
 249      file is skipped.
 250
 251      Otherwise, if the file is not skipped, then NAME_MATCHER is
 252      called for each symbol defined in the file.  The symbol's
 253      "natural" name and DATA are passed to NAME_MATCHER.
 254
 255      If NAME_MATCHER returns zero, then this symbol is skipped.
 256
 257      Otherwise, if this symbol is not skipped, and it matches KIND,
 258      then this symbol's symbol table is expanded.
 259
 260      DATA is user data that is passed unmodified to the callback
 261      functions.  */
 262   void (*expand_symtabs_matching) (struct objfile *objfile,
 263                                    int (*file_matcher) (const char *, void *),
 264                                    int (*name_matcher) (const char *, void *),
 265                                    domain_enum kind,
 266                                    void *data);
 267
 268   /* Return the symbol table from OBJFILE that contains PC and
 269      SECTION.  Return NULL if there is no such symbol table.  This
 270      should return the symbol table that contains a symbol whose
 271      address exactly matches PC, or, if there is no exact match, the
 272      symbol table that contains a symbol whose address is closest to
 273      PC.  */
 274   struct symtab *(*find_pc_sect_symtab) (struct objfile *objfile,
 275                                          struct minimal_symbol *msymbol,
 276                                          CORE_ADDR pc,
 277                                          struct obj_section *section,
 278                                          int warn_if_readin);
 279
 280   /* Call a callback for every symbol defined in OBJFILE.  FUN is the
 281      callback.  It is passed the symbol's natural name, and the DATA
 282      passed to this function.  */
 283   void (*map_symbol_names) (struct objfile *objfile,
 284                             void (*fun) (const char *, void *),
 285                             void *data);
 286
 287   /* Call a callback for every file defined in OBJFILE.  FUN is the
 288      callback.  It is passed the file's name, the file's full name,
 289      and the DATA passed to this function.  */
 290   void (*map_symbol_filenames) (struct objfile *objfile,
 291                                 void (*fun) (const char *, const char *,
 292                                              void *),
 293                                 void *data);
 294 };
 295
 296 /* Structure to keep track of symbol reading functions for various
 297    object file types.  */
 298
 299 struct sym_fns
 300 {
 301
 302   /* BFD flavour that we handle, or (as a special kludge, see
 303      xcoffread.c, (enum bfd_flavour)-1 for xcoff).  */
 304
 305   enum bfd_flavour sym_flavour;
 306
 307   /* Initializes anything that is global to the entire symbol table.
 308      It is called during symbol_file_add, when we begin debugging an
 309      entirely new program.  */
 310
 311   void (*sym_new_init) (struct objfile *);
 312
 313   /* Reads any initial information from a symbol file, and initializes
 314      the struct sym_fns SF in preparation for sym_read().  It is
 315      called every time we read a symbol file for any reason.  */
 316
 317   void (*sym_init) (struct objfile *);
 318
 319   /* sym_read (objfile, symfile_flags) Reads a symbol file into a psymtab
 320      (or possibly a symtab).  OBJFILE is the objfile struct for the
 321      file we are reading.  SYMFILE_FLAGS are the flags passed to
 322      symbol_file_add & co.  */
 323
 324   void (*sym_read) (struct objfile *, int);
 325
 326   /* Called when we are finished with an objfile.  Should do all
 327      cleanup that is specific to the object file format for the
 328      particular objfile.  */
 329
 330   void (*sym_finish) (struct objfile *);
 331
 332   /* This function produces a file-dependent section_offsets
 333      structure, allocated in the objfile's storage, and based on the
 334      parameter.  The parameter is currently a CORE_ADDR (FIXME!) for
 335      backward compatibility with the higher levels of GDB.  It should
 336      probably be changed to a string, where NULL means the default,
 337      and others are parsed in a file dependent way.  */
 338
 339   void (*sym_offsets) (struct objfile *, struct section_addr_info *);
 340
 341   /* This function produces a format-independent description of
 342      the segments of ABFD.  Each segment is a unit of the file
 343      which may be relocated independently.  */
 344
 345   struct symfile_segment_data *(*sym_segments) (bfd *abfd);
 346
 347   /* This function should read the linetable from the objfile when
 348      the line table cannot be read while processing the debugging
 349      information.  */
 350
 351   void (*sym_read_linetable) (void);
 352
 353   /* Relocate the contents of a debug section SECTP.  The
 354      contents are stored in BUF if it is non-NULL, or returned in a
 355      malloc'd buffer otherwise.  */
 356
 357   bfd_byte *(*sym_relocate) (struct objfile *, asection *sectp, bfd_byte *buf);
 358
 359   /* The "quick" (aka partial) symbol functions for this symbol
 360      reader.  */
 361   const struct quick_symbol_functions *qf;
 362 };
 363
 364 extern struct section_addr_info *
 365            build_section_addr_info_from_objfile (const struct objfile *objfile);
 366
 367 extern void relative_addr_info_to_section_offsets
 368   (struct section_offsets *section_offsets, int num_sections,
 369    struct section_addr_info *addrs);
 370
 371 extern void addr_info_make_relative (struct section_addr_info *addrs,
 372                                      bfd *abfd);
 373
 374 /* The default version of sym_fns.sym_offsets for readers that don't
 375    do anything special.  */
 376
 377 extern void default_symfile_offsets (struct objfile *objfile,
 378                                      struct section_addr_info *);
 379
 380 /* The default version of sym_fns.sym_segments for readers that don't
 381    do anything special.  */
 382
 383 extern struct symfile_segment_data *default_symfile_segments (bfd *abfd);
 384
 385 /* The default version of sym_fns.sym_relocate for readers that don't
 386    do anything special.  */
 387
 388 extern bfd_byte *default_symfile_relocate (struct objfile *objfile,
 389                                            asection *sectp, bfd_byte *buf);
 390
 391 extern struct symtab *allocate_symtab (const char *, struct objfile *);
 392
 393 extern void add_symtab_fns (const struct sym_fns *);
 394
 395 /* This enum encodes bit-flags passed as ADD_FLAGS parameter to
 396    syms_from_objfile, symbol_file_add, etc.  */
 397
 398 enum symfile_add_flags
 399   {
 400     /* Be chatty about what you are doing.  */
 401     SYMFILE_VERBOSE = 1 << 1,
 402
 403     /* This is the main symbol file (as opposed to symbol file for dynamically
 404        loaded code).  */
 405     SYMFILE_MAINLINE = 1 << 2,
 406
 407     /* Do not call breakpoint_re_set when adding this symbol file.  */
 408     SYMFILE_DEFER_BP_RESET = 1 << 3
 409   };
 410
 411 extern void syms_from_objfile (struct objfile *,
 412                                struct section_addr_info *,
 413                                struct section_offsets *, int, int);
 414
 415 extern void new_symfile_objfile (struct objfile *, int);
 416
 417 extern struct objfile *symbol_file_add (char *, int,
 418                                         struct section_addr_info *, int);
 419
 420 extern struct objfile *symbol_file_add_from_bfd (bfd *, int,
 421                                                  struct section_addr_info *,
 422                                                  int);
 423
 424 extern void symbol_file_add_separate (bfd *, int, struct objfile *);
 425
 426 extern char *find_separate_debug_file_by_debuglink (struct objfile *);
 427
 428 /* Create a new section_addr_info, with room for NUM_SECTIONS.  */
 429
 430 extern struct section_addr_info *alloc_section_addr_info (size_t
 431                                                           num_sections);
 432
 433 /* Build (allocate and populate) a section_addr_info struct from an
 434    existing section table.  */
 435
 436 extern struct section_addr_info
 437   *build_section_addr_info_from_section_table (const struct target_section
 438                                                *start,
 439                                                const struct target_section
 440                                                *end);
 441
 442 /* Free all memory allocated by
 443    build_section_addr_info_from_section_table.  */
 444
 445 extern void free_section_addr_info (struct section_addr_info *);
 446
 447
 448 /* Make a copy of the string at PTR with SIZE characters in the symbol
 449    obstack (and add a null character at the end in the copy).  Returns
 450    the address of the copy.  */
 451
 452 extern char *obsavestring (const char *, int, struct obstack *);
 453
 454 /* Concatenate NULL terminated variable argument list of `const char *' strings;
 455    return the new string.  Space is found in the OBSTACKP.  Argument list must
 456    be terminated by a sentinel expression `(char *) NULL'.  */
 457
 458 extern char *obconcat (struct obstack *obstackp, ...) ATTRIBUTE_SENTINEL;
 459
 460                         /*   Variables   */
 461
 462 /* If non-zero, shared library symbols will be added automatically
 463    when the inferior is created, new libraries are loaded, or when
 464    attaching to the inferior.  This is almost always what users will
 465    want to have happen; but for very large programs, the startup time
 466    will be excessive, and so if this is a problem, the user can clear
 467    this flag and then add the shared library symbols as needed.  Note
 468    that there is a potential for confusion, since if the shared
 469    library symbols are not loaded, commands like "info fun" will *not*
 470    report all the functions that are actually present.  */
 471
 472 extern int auto_solib_add;
 473
 474 /* For systems that support it, a threshold size in megabytes.  If
 475    automatically adding a new library's symbol table to those already
 476    known to the debugger would cause the total shared library symbol
 477    size to exceed this threshhold, then the shlib's symbols are not
 478    added.  The threshold is ignored if the user explicitly asks for a
 479    shlib to be added, such as when using the "sharedlibrary" command.  */
 480
 481 extern int auto_solib_limit;
 482
 483 /* From symfile.c */
 484
 485 extern void set_initial_language (void);
 486
 487 extern void find_lowest_section (bfd *, asection *, void *);
 488
 489 extern bfd *symfile_bfd_open (char *);
 490
 491 extern bfd *bfd_open_maybe_remote (const char *);
 492
 493 extern int get_section_index (struct objfile *, char *);
 494
 495 /* Utility functions for overlay sections: */
 496 extern enum overlay_debugging_state
 497 {
 498   ovly_off,
 499   ovly_on,
 500   ovly_auto
 501 } overlay_debugging;
 502 extern int overlay_cache_invalid;
 503
 504 /* Return the "mapped" overlay section containing the PC.  */
 505 extern struct obj_section *find_pc_mapped_section (CORE_ADDR);
 506
 507 /* Return any overlay section containing the PC (even in its LMA
 508    region).  */
 509 extern struct obj_section *find_pc_overlay (CORE_ADDR);
 510
 511 /* Return true if the section is an overlay.  */
 512 extern int section_is_overlay (struct obj_section *);
 513
 514 /* Return true if the overlay section is currently "mapped".  */
 515 extern int section_is_mapped (struct obj_section *);
 516
 517 /* Return true if pc belongs to section's VMA.  */
 518 extern CORE_ADDR pc_in_mapped_range (CORE_ADDR, struct obj_section *);
 519
 520 /* Return true if pc belongs to section's LMA.  */
 521 extern CORE_ADDR pc_in_unmapped_range (CORE_ADDR, struct obj_section *);
 522
 523 /* Map an address from a section's LMA to its VMA.  */
 524 extern CORE_ADDR overlay_mapped_address (CORE_ADDR, struct obj_section *);
 525
 526 /* Map an address from a section's VMA to its LMA.  */
 527 extern CORE_ADDR overlay_unmapped_address (CORE_ADDR, struct obj_section *);
 528
 529 /* Convert an address in an overlay section (force into VMA range).  */
 530 extern CORE_ADDR symbol_overlayed_address (CORE_ADDR, struct obj_section *);
 531
 532 /* Load symbols from a file.  */
 533 extern void symbol_file_add_main (char *args, int from_tty);
 534
 535 /* Clear GDB symbol tables.  */
 536 extern void symbol_file_clear (int from_tty);
 537
 538 /* Default overlay update function.  */
 539 extern void simple_overlay_update (struct obj_section *);
 540
 541 extern bfd_byte *symfile_relocate_debug_section (struct objfile *, asection *,
 542                                                  bfd_byte *);
 543
 544 extern int symfile_map_offsets_to_segments (bfd *,
 545                                             struct symfile_segment_data *,
 546                                             struct section_offsets *,
 547                                             int, const CORE_ADDR *);
 548 struct symfile_segment_data *get_symfile_segment_data (bfd *abfd);
 549 void free_symfile_segment_data (struct symfile_segment_data *data);
 550
 551 extern struct cleanup *increment_reading_symtab (void);
 552
 553 /* From dwarf2read.c */
 554
 555 extern int dwarf2_has_info (struct objfile *);
 556
 557 extern int dwarf2_initialize_objfile (struct objfile *);
 558 extern void dwarf2_build_psymtabs (struct objfile *);
 559 extern void dwarf2_build_frame_info (struct objfile *);
 560
 561 void dwarf2_free_objfile (struct objfile *);
 562
 563 /* From mdebugread.c */
 564
 565 /* Hack to force structures to exist before use in parameter list.  */
 566 struct ecoff_debug_hack
 567 {
 568   struct ecoff_debug_swap *a;
 569   struct ecoff_debug_info *b;
 570 };
 571
 572 extern void mdebug_build_psymtabs (struct objfile *,
 573                                    const struct ecoff_debug_swap *,
 574                                    struct ecoff_debug_info *);
 575
 576 extern void elfmdebug_build_psymtabs (struct objfile *,
 577                                       const struct ecoff_debug_swap *,
 578                                       asection *);
 579
 580 #endif /* !defined(SYMFILE_H) */