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