1 /* Definitions for reading symbol files into GDB.
2 
3    Copyright (C) 1990-2024 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 {
other_sectionsother_sections47   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   {
segmentsymfile_segment_data::segment82     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 *
allocate_symtab(struct compunit_symtab * cust,const char * filename)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    domain_search_flags 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 /* This is the symbol-file command.  Read the file, analyze its
383    symbols, and add a struct symtab to a symtab list.  The syntax of
384    the command is rather bizarre:
385 
386    1. The function buildargv implements various quoting conventions
387    which are undocumented and have little or nothing in common with
388    the way things are quoted (or not quoted) elsewhere in GDB.
389 
390    2. Options are used, which are not generally used in GDB (perhaps
391    "set mapped on", "set readnow on" would be better)
392 
393    3. The order of options matters, which is contrary to GNU
394    conventions (because it is confusing and inconvenient).  */
395 
396 extern void symbol_file_command (const char *, int);
397 
398 #endif /* !defined(SYMFILE_H) */
399