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, 2011
   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                                        enum block_enum block_kind,
 186                                        const char *name,
 187                                        domain_enum domain);
 188
 189   /* Print statistics about any indices loaded for OBJFILE.  The
 190      statistics should be printed to gdb_stdout.  This is used for
 191      "maint print statistics".  */
 192   void (*print_stats) (struct objfile *objfile);
 193
 194   /* Dump any indices loaded for OBJFILE.  The dump should go to
 195      gdb_stdout.  This is used for "maint print objfiles".  */
 196   void (*dump) (struct objfile *objfile);
 197
 198   /* This is called by objfile_relocate to relocate any indices loaded
 199      for OBJFILE.  */
 200   void (*relocate) (struct objfile *objfile,
 201                     struct section_offsets *new_offsets,
 202                     struct section_offsets *delta);
 203
 204   /* Find all the symbols in OBJFILE named FUNC_NAME, and ensure that
 205      the corresponding symbol tables are loaded.  */
 206   void (*expand_symtabs_for_function) (struct objfile *objfile,
 207                                        const char *func_name);
 208
 209   /* Read all symbol tables associated with OBJFILE.  */
 210   void (*expand_all_symtabs) (struct objfile *objfile);
 211
 212   /* Read all symbol tables associated with OBJFILE which have the
 213      file name FILENAME.
 214      This is for the purposes of examining code only, e.g., expand_line_sal.
 215      The routine may ignore debug info that is known to not be useful with
 216      code, e.g., DW_TAG_type_unit for dwarf debug info.  */
 217   void (*expand_symtabs_with_filename) (struct objfile *objfile,
 218                                         const char *filename);
 219
 220   /* Return the file name of the file holding the symbol in OBJFILE
 221      named NAME.  If no such symbol exists in OBJFILE, return NULL.  */
 222   const char *(*find_symbol_file) (struct objfile *objfile, const char *name);
 223
 224   /* Find global or static symbols in all tables that are in NAMESPACE
 225      and for which MATCH (symbol name, NAME) == 0, passing each to
 226      CALLBACK, reading in partial symbol symbol tables as needed.  Look
 227      through global symbols if GLOBAL and otherwise static symbols.
 228      Passes NAME, NAMESPACE, and DATA to CALLBACK with each symbol
 229      found.  After each block is processed, passes NULL to CALLBACK.
 230      MATCH must be weaker than strcmp_iw in the sense that
 231      strcmp_iw(x,y) == 0 --> MATCH(x,y) == 0.  ORDERED_COMPARE, if
 232      non-null, must be an ordering relation compatible with strcmp_iw
 233      in the sense that
 234             strcmp(x,y) == 0 --> ORDERED_COMPARE(x,y) == 0
 235      and
 236             strcmp(x,y) <= 0 --> ORDERED_COMPARE(x,y) <= 0
 237      (allowing strcmp(x,y) < 0 while ORDERED_COMPARE(x, y) == 0).
 238      CALLBACK returns 0 to indicate that the scan should continue, or
 239      non-zero to indicate that the scan should be terminated.  */
 240
 241   void (*map_matching_symbols) (const char *name, domain_enum namespace,
 242                                 struct objfile *, int global,
 243                                 int (*callback) (struct block *,
 244                                                  struct symbol *, void *),
 245                                 void *data,
 246                                 symbol_compare_ftype *match,
 247                                 symbol_compare_ftype *ordered_compare);
 248
 249   /* Expand all symbol tables in OBJFILE matching some criteria.
 250
 251      FILE_MATCHER is called for each file in OBJFILE.  The file name
 252      and the DATA argument are passed to it.  If it returns zero, this
 253      file is skipped.
 254
 255      Otherwise, if the file is not skipped, then NAME_MATCHER is
 256      called for each symbol defined in the file.  The symbol's
 257      "natural" name and DATA are passed to NAME_MATCHER.
 258
 259      If NAME_MATCHER returns zero, then this symbol is skipped.
 260
 261      Otherwise, if this symbol is not skipped, and it matches KIND,
 262      then this symbol's symbol table is expanded.
 263
 264      DATA is user data that is passed unmodified to the callback
 265      functions.  */
 266   void (*expand_symtabs_matching) (struct objfile *objfile,
 267                                    int (*file_matcher) (const char *, void *),
 268                                    int (*name_matcher) (const char *, void *),
 269                                    enum search_domain kind,
 270                                    void *data);
 271
 272   /* Return the symbol table from OBJFILE that contains PC and
 273      SECTION.  Return NULL if there is no such symbol table.  This
 274      should return the symbol table that contains a symbol whose
 275      address exactly matches PC, or, if there is no exact match, the
 276      symbol table that contains a symbol whose address is closest to
 277      PC.  */
 278   struct symtab *(*find_pc_sect_symtab) (struct objfile *objfile,
 279                                          struct minimal_symbol *msymbol,
 280                                          CORE_ADDR pc,
 281                                          struct obj_section *section,
 282                                          int warn_if_readin);
 283
 284   /* Call a callback for every symbol defined in OBJFILE.  FUN is the
 285      callback.  It is passed the symbol's natural name, and the DATA
 286      passed to this function.  */
 287   void (*map_symbol_names) (struct objfile *objfile,
 288                             void (*fun) (const char *, void *),
 289                             void *data);
 290
 291   /* Call a callback for every file defined in OBJFILE whose symtab is
 292      not already read in.  FUN is the callback.  It is passed the file's name,
 293      the file's full name, and the DATA passed to this function.  */
 294   void (*map_symbol_filenames) (struct objfile *objfile,
 295                                 void (*fun) (const char *, const char *,
 296                                              void *),
 297                                 void *data);
 298 };
 299
 300 /* Structure to keep track of symbol reading functions for various
 301    object file types.  */
 302
 303 struct sym_fns
 304 {
 305
 306   /* BFD flavour that we handle, or (as a special kludge, see
 307      xcoffread.c, (enum bfd_flavour)-1 for xcoff).  */
 308
 309   enum bfd_flavour sym_flavour;
 310
 311   /* Initializes anything that is global to the entire symbol table.
 312      It is called during symbol_file_add, when we begin debugging an
 313      entirely new program.  */
 314
 315   void (*sym_new_init) (struct objfile *);
 316
 317   /* Reads any initial information from a symbol file, and initializes
 318      the struct sym_fns SF in preparation for sym_read().  It is
 319      called every time we read a symbol file for any reason.  */
 320
 321   void (*sym_init) (struct objfile *);
 322
 323   /* sym_read (objfile, symfile_flags) Reads a symbol file into a psymtab
 324      (or possibly a symtab).  OBJFILE is the objfile struct for the
 325      file we are reading.  SYMFILE_FLAGS are the flags passed to
 326      symbol_file_add & co.  */
 327
 328   void (*sym_read) (struct objfile *, int);
 329
 330   /* Read the partial symbols for an objfile.  This may be NULL, in
 331      which case gdb assumes that sym_read already read the partial
 332      symbols.  This may only be non-NULL if the objfile actually does
 333      have debuginfo available.  */
 334
 335   void (*sym_read_psymbols) (struct objfile *);
 336
 337   /* Called when we are finished with an objfile.  Should do all
 338      cleanup that is specific to the object file format for the
 339      particular objfile.  */
 340
 341   void (*sym_finish) (struct objfile *);
 342
 343   /* This function produces a file-dependent section_offsets
 344      structure, allocated in the objfile's storage, and based on the
 345      parameter.  The parameter is currently a CORE_ADDR (FIXME!) for
 346      backward compatibility with the higher levels of GDB.  It should
 347      probably be changed to a string, where NULL means the default,
 348      and others are parsed in a file dependent way.  */
 349
 350   void (*sym_offsets) (struct objfile *, struct section_addr_info *);
 351
 352   /* This function produces a format-independent description of
 353      the segments of ABFD.  Each segment is a unit of the file
 354      which may be relocated independently.  */
 355
 356   struct symfile_segment_data *(*sym_segments) (bfd *abfd);
 357
 358   /* This function should read the linetable from the objfile when
 359      the line table cannot be read while processing the debugging
 360      information.  */
 361
 362   void (*sym_read_linetable) (void);
 363
 364   /* Relocate the contents of a debug section SECTP.  The
 365      contents are stored in BUF if it is non-NULL, or returned in a
 366      malloc'd buffer otherwise.  */
 367
 368   bfd_byte *(*sym_relocate) (struct objfile *, asection *sectp, bfd_byte *buf);
 369
 370   /* The "quick" (aka partial) symbol functions for this symbol
 371      reader.  */
 372   const struct quick_symbol_functions *qf;
 373 };
 374
 375 extern struct section_addr_info *
 376   build_section_addr_info_from_objfile (const struct objfile *objfile);
 377
 378 extern void relative_addr_info_to_section_offsets
 379   (struct section_offsets *section_offsets, int num_sections,
 380    struct section_addr_info *addrs);
 381
 382 extern void addr_info_make_relative (struct section_addr_info *addrs,
 383                                      bfd *abfd);
 384
 385 /* The default version of sym_fns.sym_offsets for readers that don't
 386    do anything special.  */
 387
 388 extern void default_symfile_offsets (struct objfile *objfile,
 389                                      struct section_addr_info *);
 390
 391 /* The default version of sym_fns.sym_segments for readers that don't
 392    do anything special.  */
 393
 394 extern struct symfile_segment_data *default_symfile_segments (bfd *abfd);
 395
 396 /* The default version of sym_fns.sym_relocate for readers that don't
 397    do anything special.  */
 398
 399 extern bfd_byte *default_symfile_relocate (struct objfile *objfile,
 400                                            asection *sectp, bfd_byte *buf);
 401
 402 extern struct symtab *allocate_symtab (const char *, struct objfile *);
 403
 404 extern void add_symtab_fns (const struct sym_fns *);
 405
 406 /* This enum encodes bit-flags passed as ADD_FLAGS parameter to
 407    syms_from_objfile, symbol_file_add, etc.  */
 408
 409 enum symfile_add_flags
 410   {
 411     /* Be chatty about what you are doing.  */
 412     SYMFILE_VERBOSE = 1 << 1,
 413
 414     /* This is the main symbol file (as opposed to symbol file for dynamically
 415        loaded code).  */
 416     SYMFILE_MAINLINE = 1 << 2,
 417
 418     /* Do not call breakpoint_re_set when adding this symbol file.  */
 419     SYMFILE_DEFER_BP_RESET = 1 << 3,
 420
 421     /* Do not immediately read symbols for this file.  By default,
 422        symbols are read when the objfile is created.  */
 423     SYMFILE_NO_READ = 1 << 4
 424   };
 425
 426 extern void syms_from_objfile (struct objfile *,
 427                                struct section_addr_info *,
 428                                struct section_offsets *, int, int);
 429
 430 extern void new_symfile_objfile (struct objfile *, int);
 431
 432 extern struct objfile *symbol_file_add (char *, int,
 433                                         struct section_addr_info *, int);
 434
 435 extern struct objfile *symbol_file_add_from_bfd (bfd *, int,
 436                                                  struct section_addr_info *,
 437                                                  int);
 438
 439 extern void symbol_file_add_separate (bfd *, int, struct objfile *);
 440
 441 extern char *find_separate_debug_file_by_debuglink (struct objfile *);
 442
 443 /* Create a new section_addr_info, with room for NUM_SECTIONS.  */
 444
 445 extern struct section_addr_info *alloc_section_addr_info (size_t
 446                                                           num_sections);
 447
 448 /* Build (allocate and populate) a section_addr_info struct from an
 449    existing section table.  */
 450
 451 extern struct section_addr_info
 452   *build_section_addr_info_from_section_table (const struct target_section
 453                                                *start,
 454                                                const struct target_section
 455                                                *end);
 456
 457 /* Free all memory allocated by
 458    build_section_addr_info_from_section_table.  */
 459
 460 extern void free_section_addr_info (struct section_addr_info *);
 461
 462
 463 /* Make a copy of the string at PTR with SIZE characters in the symbol
 464    obstack (and add a null character at the end in the copy).  Returns
 465    the address of the copy.  */
 466
 467 extern char *obsavestring (const char *, int, struct obstack *);
 468
 469 /* Concatenate NULL terminated variable argument list of `const char
 470    *' strings; return the new string.  Space is found in the OBSTACKP.
 471    Argument list must be terminated by a sentinel expression `(char *)
 472    NULL'.  */
 473
 474 extern char *obconcat (struct obstack *obstackp, ...) ATTRIBUTE_SENTINEL;
 475
 476                         /*   Variables   */
 477
 478 /* If non-zero, shared library symbols will be added automatically
 479    when the inferior is created, new libraries are loaded, or when
 480    attaching to the inferior.  This is almost always what users will
 481    want to have happen; but for very large programs, the startup time
 482    will be excessive, and so if this is a problem, the user can clear
 483    this flag and then add the shared library symbols as needed.  Note
 484    that there is a potential for confusion, since if the shared
 485    library symbols are not loaded, commands like "info fun" will *not*
 486    report all the functions that are actually present.  */
 487
 488 extern int auto_solib_add;
 489
 490 /* From symfile.c */
 491
 492 extern void set_initial_language (void);
 493
 494 extern void find_lowest_section (bfd *, asection *, void *);
 495
 496 extern bfd *symfile_bfd_open (char *);
 497
 498 extern bfd *bfd_open_maybe_remote (const char *);
 499
 500 extern int get_section_index (struct objfile *, char *);
 501
 502 /* Utility functions for overlay sections: */
 503 extern enum overlay_debugging_state
 504 {
 505   ovly_off,
 506   ovly_on,
 507   ovly_auto
 508 } overlay_debugging;
 509 extern int overlay_cache_invalid;
 510
 511 /* Return the "mapped" overlay section containing the PC.  */
 512 extern struct obj_section *find_pc_mapped_section (CORE_ADDR);
 513
 514 /* Return any overlay section containing the PC (even in its LMA
 515    region).  */
 516 extern struct obj_section *find_pc_overlay (CORE_ADDR);
 517
 518 /* Return true if the section is an overlay.  */
 519 extern int section_is_overlay (struct obj_section *);
 520
 521 /* Return true if the overlay section is currently "mapped".  */
 522 extern int section_is_mapped (struct obj_section *);
 523
 524 /* Return true if pc belongs to section's VMA.  */
 525 extern CORE_ADDR pc_in_mapped_range (CORE_ADDR, struct obj_section *);
 526
 527 /* Return true if pc belongs to section's LMA.  */
 528 extern CORE_ADDR pc_in_unmapped_range (CORE_ADDR, struct obj_section *);
 529
 530 /* Map an address from a section's LMA to its VMA.  */
 531 extern CORE_ADDR overlay_mapped_address (CORE_ADDR, struct obj_section *);
 532
 533 /* Map an address from a section's VMA to its LMA.  */
 534 extern CORE_ADDR overlay_unmapped_address (CORE_ADDR, struct obj_section *);
 535
 536 /* Convert an address in an overlay section (force into VMA range).  */
 537 extern CORE_ADDR symbol_overlayed_address (CORE_ADDR, struct obj_section *);
 538
 539 /* Load symbols from a file.  */
 540 extern void symbol_file_add_main (char *args, int from_tty);
 541
 542 /* Clear GDB symbol tables.  */
 543 extern void symbol_file_clear (int from_tty);
 544
 545 /* Default overlay update function.  */
 546 extern void simple_overlay_update (struct obj_section *);
 547
 548 extern bfd_byte *symfile_relocate_debug_section (struct objfile *, asection *,
 549                                                  bfd_byte *);
 550
 551 extern int symfile_map_offsets_to_segments (bfd *,
 552                                             struct symfile_segment_data *,
 553                                             struct section_offsets *,
 554                                             int, const CORE_ADDR *);
 555 struct symfile_segment_data *get_symfile_segment_data (bfd *abfd);
 556 void free_symfile_segment_data (struct symfile_segment_data *data);
 557
 558 extern struct cleanup *increment_reading_symtab (void);
 559
 560 /* From dwarf2read.c */
 561
 562 extern int dwarf2_has_info (struct objfile *);
 563
 564 extern int dwarf2_initialize_objfile (struct objfile *);
 565 extern void dwarf2_build_psymtabs (struct objfile *);
 566 extern void dwarf2_build_frame_info (struct objfile *);
 567
 568 void dwarf2_free_objfile (struct objfile *);
 569
 570 /* From mdebugread.c */
 571
 572 /* Hack to force structures to exist before use in parameter list.  */
 573 struct ecoff_debug_hack
 574 {
 575   struct ecoff_debug_swap *a;
 576   struct ecoff_debug_info *b;
 577 };
 578
 579 extern void mdebug_build_psymtabs (struct objfile *,
 580                                    const struct ecoff_debug_swap *,
 581                                    struct ecoff_debug_info *);
 582
 583 extern void elfmdebug_build_psymtabs (struct objfile *,
 584                                       const struct ecoff_debug_swap *,
 585                                       asection *);
 586
 587 #endif /* !defined(SYMFILE_H) */