gdb/symfile.h

   1 /* Definitions for reading symbol files into GDB.
   2
   3    Copyright (C) 1990-2023 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #if !defined (SYMFILE_H)
  21 #define SYMFILE_H
  22
  23 /* This file requires that you first include "bfd.h".  */
  24 #include "symtab.h"
  25 #include "probe.h"
  26 #include "symfile-add-flags.h"
  27 #include "objfile-flags.h"
  28 #include "gdb_bfd.h"
  29 #include "gdbsupport/function-view.h"
  30 #include "target-section.h"
  31 #include "quick-symbol.h"
  32
  33 /* Opaque declarations.  */
  34 struct target_section;
  35 struct objfile;
  36 struct obj_section;
  37 struct obstack;
  38 struct block;
  39 struct value;
  40 class frame_info_ptr;
  41 struct agent_expr;
  42 struct axs_value;
  43 class probe;
  44
  45 struct other_sections
  46 {
  47   other_sections (CORE_ADDR addr_, std::string &&name_, int sectindex_)
  48     : addr (addr_),
  49       name (std::move (name_)),
  50       sectindex (sectindex_)
  51   {
  52   }
  53
  54   other_sections (other_sections &&other) = default;
  55
  56   DISABLE_COPY_AND_ASSIGN (other_sections);
  57
  58   CORE_ADDR addr;
  59   std::string name;
  60
  61   /* SECTINDEX must be valid for associated BFD or set to -1.
  62      See syms_from_objfile_1 for an exception to this rule.
  63    */
  64   int sectindex;
  65 };
  66
  67 /* Define an array of addresses to accommodate non-contiguous dynamic
  68    loading of modules.  This is for use when entering commands, so we
  69    can keep track of the section names until we read the file and can
  70    map them to bfd sections.  This structure is also used by solib.c
  71    to communicate the section addresses in shared objects to
  72    symbol_file_add ().  */
  73
  74 typedef std::vector<other_sections> section_addr_info;
  75
  76 /* A table listing the load segments in a symfile, and which segment
  77    each BFD section belongs to.  */
  78 struct symfile_segment_data
  79 {
  80   struct segment
  81   {
  82     segment (CORE_ADDR base, CORE_ADDR size)
  83       : base (base), size (size)
  84     {}
  85
  86     /* The original base address the segment.  */
  87     CORE_ADDR base;
  88
  89     /* The memory size of the segment.  */
  90     CORE_ADDR size;
  91   };
  92
  93   /* The segments present in this file.  If there are
  94      two, the text segment is the first one and the data segment
  95      is the second one.  */
  96   std::vector<segment> segments;
  97
  98   /* This is an array of entries recording which segment contains each BFD
  99      section.  SEGMENT_INFO[I] is S+1 if the I'th BFD section belongs to segment
 100      S, or zero if it is not in any segment.  */
 101   std::vector<int> segment_info;
 102 };
 103
 104 using symfile_segment_data_up = std::unique_ptr<symfile_segment_data>;
 105
 106 /* Structure of functions used for probe support.  If one of these functions
 107    is provided, all must be.  */
 108
 109 struct sym_probe_fns
 110 {
 111   /* If non-NULL, return a reference to vector of probe objects.  */
 112   const std::vector<std::unique_ptr<probe>> &(*sym_get_probes)
 113     (struct objfile *);
 114 };
 115
 116 /* Structure to keep track of symbol reading functions for various
 117    object file types.  */
 118
 119 struct sym_fns
 120 {
 121   /* Initializes anything that is global to the entire symbol table.
 122      It is called during symbol_file_add, when we begin debugging an
 123      entirely new program.  */
 124
 125   void (*sym_new_init) (struct objfile *);
 126
 127   /* Reads any initial information from a symbol file, and initializes
 128      the struct sym_fns SF in preparation for sym_read().  It is
 129      called every time we read a symbol file for any reason.  */
 130
 131   void (*sym_init) (struct objfile *);
 132
 133   /* sym_read (objfile, symfile_flags) Reads a symbol file into a psymtab
 134      (or possibly a symtab).  OBJFILE is the objfile struct for the
 135      file we are reading.  SYMFILE_FLAGS are the flags passed to
 136      symbol_file_add & co.  */
 137
 138   void (*sym_read) (struct objfile *, symfile_add_flags);
 139
 140   /* Called when we are finished with an objfile.  Should do all
 141      cleanup that is specific to the object file format for the
 142      particular objfile.  */
 143
 144   void (*sym_finish) (struct objfile *);
 145
 146
 147   /* This function produces a file-dependent section_offsets
 148      structure, allocated in the objfile's storage.
 149
 150      The section_addr_info structure contains the offset of loadable and
 151      allocated sections, relative to the absolute offsets found in the BFD.  */
 152
 153   void (*sym_offsets) (struct objfile *, const section_addr_info &);
 154
 155   /* This function produces a format-independent description of
 156      the segments of ABFD.  Each segment is a unit of the file
 157      which may be relocated independently.  */
 158
 159   symfile_segment_data_up (*sym_segments) (bfd *abfd);
 160
 161   /* This function should read the linetable from the objfile when
 162      the line table cannot be read while processing the debugging
 163      information.  */
 164
 165   void (*sym_read_linetable) (struct objfile *);
 166
 167   /* Relocate the contents of a debug section SECTP.  The
 168      contents are stored in BUF if it is non-NULL, or returned in a
 169      malloc'd buffer otherwise.  */
 170
 171   bfd_byte *(*sym_relocate) (struct objfile *, asection *sectp, bfd_byte *buf);
 172
 173   /* If non-NULL, this objfile has probe support, and all the probe
 174      functions referred to here will be non-NULL.  */
 175   const struct sym_probe_fns *sym_probe_fns;
 176 };
 177
 178 extern section_addr_info
 179   build_section_addr_info_from_objfile (const struct objfile *objfile);
 180
 181 extern void relative_addr_info_to_section_offsets
 182   (section_offsets &section_offsets, const section_addr_info &addrs);
 183
 184 extern void addr_info_make_relative (section_addr_info *addrs,
 185                                      bfd *abfd);
 186
 187 /* The default version of sym_fns.sym_offsets for readers that don't
 188    do anything special.  */
 189
 190 extern void default_symfile_offsets (struct objfile *objfile,
 191                                      const section_addr_info &);
 192
 193 /* The default version of sym_fns.sym_segments for readers that don't
 194    do anything special.  */
 195
 196 extern symfile_segment_data_up default_symfile_segments (bfd *abfd);
 197
 198 /* The default version of sym_fns.sym_relocate for readers that don't
 199    do anything special.  */
 200
 201 extern bfd_byte *default_symfile_relocate (struct objfile *objfile,
 202                                            asection *sectp, bfd_byte *buf);
 203
 204 extern struct symtab *allocate_symtab
 205   (struct compunit_symtab *cust, const char *filename, const char *id)
 206   ATTRIBUTE_NONNULL (1);
 207
 208 /* Same as the above, but passes FILENAME for ID.  */
 209
 210 static inline struct symtab *
 211 allocate_symtab (struct compunit_symtab *cust, const char *filename)
 212 {
 213   return allocate_symtab (cust, filename, filename);
 214 }
 215
 216 extern struct compunit_symtab *allocate_compunit_symtab (struct objfile *,
 217                                                          const char *)
 218   ATTRIBUTE_NONNULL (1);
 219
 220 extern void add_compunit_symtab_to_objfile (struct compunit_symtab *cu);
 221
 222 extern void add_symtab_fns (enum bfd_flavour flavour, const struct sym_fns *);
 223
 224 extern void clear_symtab_users (symfile_add_flags add_flags);
 225
 226 extern enum language deduce_language_from_filename (const char *);
 227
 228 /* Map the filename extension EXT to the language LANG.  Any previous
 229    association of EXT will be removed.  EXT will be copied by this
 230    function.  */
 231 extern void add_filename_language (const char *ext, enum language lang);
 232
 233 extern struct objfile *symbol_file_add (const char *, symfile_add_flags,
 234                                         section_addr_info *, objfile_flags);
 235
 236 extern struct objfile *symbol_file_add_from_bfd (const gdb_bfd_ref_ptr &,
 237                                                  const char *, symfile_add_flags,
 238                                                  section_addr_info *,
 239                                                  objfile_flags, struct objfile *parent);
 240
 241 extern void symbol_file_add_separate (const gdb_bfd_ref_ptr &, const char *,
 242                                       symfile_add_flags, struct objfile *);
 243
 244 /* Find separate debuginfo for OBJFILE (using .gnu_debuglink section).
 245    Returns pathname, or an empty string.
 246
 247    Any warnings generated as part of this lookup are added to WARNINGS.  If
 248    some other mechanism can be used to lookup the debug information then
 249    the warning will not be shown, however, if GDB fails to find suitable
 250    debug information using any approach, then any warnings will be
 251    printed.  */
 252
 253 extern std::string find_separate_debug_file_by_debuglink
 254   (struct objfile *objfile, deferred_warnings *warnings);
 255
 256 /* Build (allocate and populate) a section_addr_info struct from an
 257    existing section table.  */
 258
 259 extern section_addr_info
 260     build_section_addr_info_from_section_table (const std::vector<target_section> &table);
 261
 262                         /*   Variables   */
 263
 264 /* If true, shared library symbols will be added automatically
 265    when the inferior is created, new libraries are loaded, or when
 266    attaching to the inferior.  This is almost always what users will
 267    want to have happen; but for very large programs, the startup time
 268    will be excessive, and so if this is a problem, the user can clear
 269    this flag and then add the shared library symbols as needed.  Note
 270    that there is a potential for confusion, since if the shared
 271    library symbols are not loaded, commands like "info fun" will *not*
 272    report all the functions that are actually present.  */
 273
 274 extern bool auto_solib_add;
 275
 276 /* From symfile.c */
 277
 278 extern void set_initial_language (void);
 279
 280 extern gdb_bfd_ref_ptr symfile_bfd_open (const char *);
 281
 282 /* Like symfile_bfd_open, but will not throw an exception on error.
 283    Instead, it issues a warning and returns nullptr.  */
 284
 285 extern gdb_bfd_ref_ptr symfile_bfd_open_no_error (const char *) noexcept;
 286
 287 extern int get_section_index (struct objfile *, const char *);
 288
 289 extern int print_symbol_loading_p (int from_tty, int mainline, int full);
 290
 291 /* Utility functions for overlay sections: */
 292 extern enum overlay_debugging_state
 293 {
 294   ovly_off,
 295   ovly_on,
 296   ovly_auto
 297 } overlay_debugging;
 298 extern int overlay_cache_invalid;
 299
 300 /* Return the "mapped" overlay section containing the PC.  */
 301 extern struct obj_section *find_pc_mapped_section (CORE_ADDR);
 302
 303 /* Return any overlay section containing the PC (even in its LMA
 304    region).  */
 305 extern struct obj_section *find_pc_overlay (CORE_ADDR);
 306
 307 /* Return true if the section is an overlay.  */
 308 extern int section_is_overlay (struct obj_section *);
 309
 310 /* Return true if the overlay section is currently "mapped".  */
 311 extern int section_is_mapped (struct obj_section *);
 312
 313 /* Return true if pc belongs to section's VMA.  */
 314 extern bool pc_in_mapped_range (CORE_ADDR, struct obj_section *);
 315
 316 /* Return true if pc belongs to section's LMA.  */
 317 extern bool pc_in_unmapped_range (CORE_ADDR, struct obj_section *);
 318
 319 /* Map an address from a section's LMA to its VMA.  */
 320 extern CORE_ADDR overlay_mapped_address (CORE_ADDR, struct obj_section *);
 321
 322 /* Map an address from a section's VMA to its LMA.  */
 323 extern CORE_ADDR overlay_unmapped_address (CORE_ADDR, struct obj_section *);
 324
 325 /* Convert an address in an overlay section (force into VMA range).  */
 326 extern CORE_ADDR symbol_overlayed_address (CORE_ADDR, struct obj_section *);
 327
 328 /* Load symbols from a file.  */
 329 extern void symbol_file_add_main (const char *args,
 330                                   symfile_add_flags add_flags);
 331
 332 /* Clear GDB symbol tables.  */
 333 extern void symbol_file_clear (int from_tty);
 334
 335 /* Default overlay update function.  */
 336 extern void simple_overlay_update (struct obj_section *);
 337
 338 extern bfd_byte *symfile_relocate_debug_section (struct objfile *, asection *,
 339                                                  bfd_byte *);
 340
 341 extern int symfile_map_offsets_to_segments (bfd *,
 342                                             const struct symfile_segment_data *,
 343                                             section_offsets &,
 344                                             int, const CORE_ADDR *);
 345 symfile_segment_data_up get_symfile_segment_data (bfd *abfd);
 346
 347 extern scoped_restore_tmpl<int> increment_reading_symtab (void);
 348
 349 bool expand_symtabs_matching
 350   (gdb::function_view<expand_symtabs_file_matcher_ftype> file_matcher,
 351    const lookup_name_info &lookup_name,
 352    gdb::function_view<expand_symtabs_symbol_matcher_ftype> symbol_matcher,
 353    gdb::function_view<expand_symtabs_exp_notify_ftype> expansion_notify,
 354    block_search_flags search_flags,
 355    enum search_domain kind);
 356
 357 void map_symbol_filenames (gdb::function_view<symbol_filename_ftype> fun,
 358                            bool need_fullname);
 359
 360 /* Target-agnostic function to load the sections of an executable into memory.
 361
 362    ARGS should be in the form "EXECUTABLE [OFFSET]", where OFFSET is an
 363    optional offset to apply to each section.  */
 364 extern void generic_load (const char *args, int from_tty);
 365
 366 /* From minidebug.c.  */
 367
 368 extern gdb_bfd_ref_ptr find_separate_debug_file_in_section (struct objfile *);
 369
 370 /* True if we are printing debug output about separate debug info files.  */
 371
 372 extern bool separate_debug_file_debug;
 373
 374 /* Read full symbols immediately.  */
 375
 376 extern int readnow_symbol_files;
 377
 378 /* Never read full symbols.  */
 379
 380 extern int readnever_symbol_files;
 381
 382 #endif /* !defined(SYMFILE_H) */