1 /* Definitions for symbol file management in GDB.
3 Copyright (C) 1992-2017 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
20 #if !defined (OBJFILES_H)
24 #include "gdb_obstack.h" /* For obstack internals. */
25 #include "objfile-flags.h"
26 #include "symfile.h" /* For struct psymbol_allocation_list. */
27 #include "progspace.h"
35 /* This structure maintains information on a per-objfile basis about the
36 "entry point" of the objfile, and the scope within which the entry point
37 exists. It is possible that gdb will see more than one objfile that is
38 executable, each with its own entry point.
40 For example, for dynamically linked executables in SVR4, the dynamic linker
41 code is contained within the shared C library, which is actually executable
42 and is run by the kernel first when an exec is done of a user executable
43 that is dynamically linked. The dynamic linker within the shared C library
44 then maps in the various program segments in the user executable and jumps
45 to the user executable's recorded entry point, as if the call had been made
46 directly by the kernel.
48 The traditional gdb method of using this info was to use the
49 recorded entry point to set the entry-file's lowpc and highpc from
50 the debugging information, where these values are the starting
51 address (inclusive) and ending address (exclusive) of the
52 instruction space in the executable which correspond to the
53 "startup file", i.e. crt0.o in most cases. This file is assumed to
54 be a startup file and frames with pc's inside it are treated as
55 nonexistent. Setting these variables is necessary so that
56 backtraces do not fly off the bottom of the stack.
58 NOTE: cagney/2003-09-09: It turns out that this "traditional"
59 method doesn't work. Corinna writes: ``It turns out that the call
60 to test for "inside entry file" destroys a meaningful backtrace
61 under some conditions. E.g. the backtrace tests in the asm-source
62 testcase are broken for some targets. In this test the functions
63 are all implemented as part of one file and the testcase is not
64 necessarily linked with a start file (depending on the target).
65 What happens is, that the first frame is printed normaly and
66 following frames are treated as being inside the enttry file then.
67 This way, only the #0 frame is printed in the backtrace output.''
68 Ref "frame.c" "NOTE: vinschen/2003-04-01".
70 Gdb also supports an alternate method to avoid running off the bottom
73 There are two frames that are "special", the frame for the function
74 containing the process entry point, since it has no predecessor frame,
75 and the frame for the function containing the user code entry point
76 (the main() function), since all the predecessor frames are for the
77 process startup code. Since we have no guarantee that the linked
78 in startup modules have any debugging information that gdb can use,
79 we need to avoid following frame pointers back into frames that might
80 have been built in the startup code, as we might get hopelessly
81 confused. However, we almost always have debugging information
84 These variables are used to save the range of PC values which are
85 valid within the main() function and within the function containing
86 the process entry point. If we always consider the frame for
87 main() as the outermost frame when debugging user code, and the
88 frame for the process entry point function as the outermost frame
89 when debugging startup code, then all we have to do is have
90 DEPRECATED_FRAME_CHAIN_VALID return false whenever a frame's
91 current PC is within the range specified by these variables. In
92 essence, we set "ceilings" in the frame chain beyond which we will
93 not proceed when following the frame chain back up the stack.
95 A nice side effect is that we can still debug startup code without
96 running off the end of the frame chain, assuming that we have usable
97 debugging information in the startup modules, and if we choose to not
98 use the block at main, or can't find it for some reason, everything
99 still works as before. And if we have no startup code debugging
100 information but we do have usable information for main(), backtraces
101 from user code don't go wandering off into the startup code. */
105 /* The unrelocated value we should use for this objfile entry point. */
106 CORE_ADDR entry_point;
108 /* The index of the section in which the entry point appears. */
109 int the_bfd_section_index;
111 /* Set to 1 iff ENTRY_POINT contains a valid value. */
112 unsigned entry_point_p : 1;
114 /* Set to 1 iff this object was initialized. */
115 unsigned initialized : 1;
118 /* Sections in an objfile. The section offsets are stored in the
123 /* BFD section pointer */
124 struct bfd_section *the_bfd_section;
126 /* Objfile this section is part of. */
127 struct objfile *objfile;
129 /* True if this "overlay section" is mapped into an "overlay region". */
133 /* Relocation offset applied to S. */
134 #define obj_section_offset(s) \
135 (((s)->objfile->section_offsets)->offsets[gdb_bfd_section_index ((s)->objfile->obfd, (s)->the_bfd_section)])
137 /* The memory address of section S (vma + offset). */
138 #define obj_section_addr(s) \
139 (bfd_get_section_vma ((s)->objfile->obfd, s->the_bfd_section) \
140 + obj_section_offset (s))
142 /* The one-passed-the-end memory address of section S
143 (vma + size + offset). */
144 #define obj_section_endaddr(s) \
145 (bfd_get_section_vma ((s)->objfile->obfd, s->the_bfd_section) \
146 + bfd_get_section_size ((s)->the_bfd_section) \
147 + obj_section_offset (s))
149 /* The "objstats" structure provides a place for gdb to record some
150 interesting information about its internal state at runtime, on a
151 per objfile basis, such as information about the number of symbols
152 read, size of string table (if any), etc. */
156 /* Number of partial symbols read. */
159 /* Number of full symbols read. */
162 /* Number of ".stabs" read (if applicable). */
165 /* Number of types. */
168 /* Size of stringtable, (if applicable). */
172 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
173 #define OBJSTATS struct objstats stats
174 extern void print_objfile_statistics (void);
175 extern void print_symbol_bcache_statistics (void);
177 /* Number of entries in the minimal symbol hash table. */
178 #define MINIMAL_SYMBOL_HASH_SIZE 2039
180 /* Some objfile data is hung off the BFD. This enables sharing of the
181 data across all objfiles using the BFD. The data is stored in an
182 instance of this structure, and associated with the BFD using the
185 struct objfile_per_bfd_storage
187 /* The storage has an obstack of its own. */
189 struct obstack storage_obstack;
191 /* Byte cache for file names. */
193 struct bcache *filename_cache;
195 /* Byte cache for macros. */
197 struct bcache *macro_cache;
199 /* The gdbarch associated with the BFD. Note that this gdbarch is
200 determined solely from BFD information, without looking at target
201 information. The gdbarch determined from a running target may
202 differ from this e.g. with respect to register types and names. */
204 struct gdbarch *gdbarch;
206 /* Hash table for mapping symbol names to demangled names. Each
207 entry in the hash table is actually two consecutive strings,
208 both null-terminated; the first one is a mangled or linkage
209 name, and the second is the demangled name or just a zero byte
210 if the name doesn't demangle. */
212 struct htab *demangled_names_hash;
214 /* The per-objfile information about the entry point, the scope (file/func)
215 containing the entry point, and the scope of the user's main() func. */
217 struct entry_info ei;
219 /* The name and language of any "main" found in this objfile. The
220 name can be NULL, which means that the information was not
223 const char *name_of_main;
224 enum language language_of_main;
226 /* Each file contains a pointer to an array of minimal symbols for all
227 global symbols that are defined within the file. The array is
228 terminated by a "null symbol", one that has a NULL pointer for the
229 name and a zero value for the address. This makes it easy to walk
230 through the array when passed a pointer to somewhere in the middle
231 of it. There is also a count of the number of symbols, which does
232 not include the terminating null symbol. The array itself, as well
233 as all the data that it points to, should be allocated on the
234 objfile_obstack for this file. */
236 struct minimal_symbol *msymbols;
237 int minimal_symbol_count;
239 /* The number of minimal symbols read, before any minimal symbol
240 de-duplication is applied. Note in particular that this has only
241 a passing relationship with the actual size of the table above;
242 use minimal_symbol_count if you need the true size. */
246 /* This is true if minimal symbols have already been read. Symbol
247 readers can use this to bypass minimal symbol reading. Also, the
248 minimal symbol table management code in minsyms.c uses this to
249 suppress new minimal symbols. You might think that MSYMBOLS or
250 MINIMAL_SYMBOL_COUNT could be used for this, but it is possible
251 for multiple readers to install minimal symbols into a given
254 unsigned int minsyms_read : 1;
256 /* This is a hash table used to index the minimal symbols by name. */
258 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
260 /* This hash table is used to index the minimal symbols by their
263 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
266 /* Master structure for keeping track of each file from which
267 gdb reads symbols. There are several ways these get allocated: 1.
268 The main symbol file, symfile_objfile, set by the symbol-file command,
269 2. Additional symbol files added by the add-symbol-file command,
270 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
271 for modules that were loaded when GDB attached to a remote system
272 (see remote-vx.c). */
276 /* All struct objfile's are chained together by their next pointers.
277 The program space field "objfiles" (frequently referenced via
278 the macro "object_files") points to the first link in this chain. */
280 struct objfile *next;
282 /* The object file's original name as specified by the user,
283 made absolute, and tilde-expanded. However, it is not canonicalized
284 (i.e., it has not been passed through gdb_realpath).
285 This pointer is never NULL. This does not have to be freed; it is
286 guaranteed to have a lifetime at least as long as the objfile. */
292 /* Some flag bits for this objfile. */
296 /* The program space associated with this objfile. */
298 struct program_space *pspace;
300 /* List of compunits.
301 These are used to do symbol lookups and file/line-number lookups. */
303 struct compunit_symtab *compunit_symtabs;
305 /* Each objfile points to a linked list of partial symtabs derived from
306 this file, one partial symtab structure for each compilation unit
309 struct partial_symtab *psymtabs;
311 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
312 have a map per the whole process but ADDRMAP cannot selectively remove
313 its items during FREE_OBJFILE. This mapping is already present even for
314 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
316 struct addrmap *psymtabs_addrmap;
318 /* List of freed partial symtabs, available for re-use. */
320 struct partial_symtab *free_psymtabs;
322 /* The object file's BFD. Can be null if the objfile contains only
323 minimal symbols, e.g. the run time common symbols for SunOS4. */
327 /* The per-BFD data. Note that this is treated specially if OBFD
330 struct objfile_per_bfd_storage *per_bfd;
332 /* The modification timestamp of the object file, as of the last time
333 we read its symbols. */
337 /* Obstack to hold objects that should be freed when we load a new symbol
338 table from this object file. */
340 struct obstack objfile_obstack;
342 /* A byte cache where we can stash arbitrary "chunks" of bytes that
345 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
347 /* Vectors of all partial symbols read in from file. The actual data
348 is stored in the objfile_obstack. */
350 struct psymbol_allocation_list global_psymbols;
351 struct psymbol_allocation_list static_psymbols;
353 /* Structure which keeps track of functions that manipulate objfile's
354 of the same type as this objfile. I.e. the function to read partial
355 symbols for example. Note that this structure is in statically
356 allocated memory, and is shared by all objfiles that use the
357 object module reader of this type. */
359 const struct sym_fns *sf;
361 /* Per objfile data-pointers required by other GDB modules. */
365 /* Set of relocation offsets to apply to each section.
366 The table is indexed by the_bfd_section->index, thus it is generally
367 as large as the number of sections in the binary.
368 The table is stored on the objfile_obstack.
370 These offsets indicate that all symbols (including partial and
371 minimal symbols) which have been read have been relocated by this
372 much. Symbols which are yet to be read need to be relocated by it. */
374 struct section_offsets *section_offsets;
377 /* Indexes in the section_offsets array. These are initialized by the
378 *_symfile_offsets() family of functions (som_symfile_offsets,
379 xcoff_symfile_offsets, default_symfile_offsets). In theory they
380 should correspond to the section indexes used by bfd for the
381 current objfile. The exception to this for the time being is the
387 int sect_index_rodata;
389 /* These pointers are used to locate the section table, which
390 among other things, is used to map pc addresses into sections.
391 SECTIONS points to the first entry in the table, and
392 SECTIONS_END points to the first location past the last entry
393 in the table. The table is stored on the objfile_obstack. The
394 sections are indexed by the BFD section index; but the
395 structure data is only valid for certain sections
396 (e.g. non-empty, SEC_ALLOC). */
398 struct obj_section *sections, *sections_end;
400 /* GDB allows to have debug symbols in separate object files. This is
401 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
402 Although this is a tree structure, GDB only support one level
403 (ie a separate debug for a separate debug is not supported). Note that
404 separate debug object are in the main chain and therefore will be
405 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
406 has a non-nul separate_debug_objfile_backlink. */
408 /* Link to the first separate debug object, if any. */
410 struct objfile *separate_debug_objfile;
412 /* If this is a separate debug object, this is used as a link to the
413 actual executable objfile. */
415 struct objfile *separate_debug_objfile_backlink;
417 /* If this is a separate debug object, this is a link to the next one
418 for the same executable objfile. */
420 struct objfile *separate_debug_objfile_link;
422 /* Place to stash various statistics about this objfile. */
426 /* A linked list of symbols created when reading template types or
427 function templates. These symbols are not stored in any symbol
428 table, so we have to keep them here to relocate them
431 struct symbol *template_symbols;
433 /* Associate a static link (struct dynamic_prop *) to all blocks (struct
434 block *) that have one.
436 In the context of nested functions (available in Pascal, Ada and GNU C,
437 for instance), a static link (as in DWARF's DW_AT_static_link attribute)
438 for a function is a way to get the frame corresponding to the enclosing
441 Very few blocks have a static link, so it's more memory efficient to
442 store these here rather than in struct block. Static links must be
443 allocated on the objfile's obstack. */
447 /* Declarations for functions defined in objfiles.c */
449 extern struct objfile *allocate_objfile (bfd *, const char *name,
452 extern struct gdbarch *get_objfile_arch (const struct objfile *);
454 extern int entry_point_address_query (CORE_ADDR *entry_p);
456 extern CORE_ADDR entry_point_address (void);
458 extern void build_objfile_section_table (struct objfile *);
460 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
461 const struct objfile *);
463 extern void put_objfile_before (struct objfile *, struct objfile *);
465 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
467 extern void unlink_objfile (struct objfile *);
469 extern void free_objfile (struct objfile *);
471 extern void free_objfile_separate_debug (struct objfile *);
473 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
475 extern void free_all_objfiles (void);
477 extern void objfile_relocate (struct objfile *, const struct section_offsets *);
478 extern void objfile_rebase (struct objfile *, CORE_ADDR);
480 extern int objfile_has_partial_symbols (struct objfile *objfile);
482 extern int objfile_has_full_symbols (struct objfile *objfile);
484 extern int objfile_has_symbols (struct objfile *objfile);
486 extern int have_partial_symbols (void);
488 extern int have_full_symbols (void);
490 extern void objfile_set_sym_fns (struct objfile *objfile,
491 const struct sym_fns *sf);
493 extern void objfiles_changed (void);
495 extern int is_addr_in_objfile (CORE_ADDR addr, const struct objfile *objfile);
497 /* Return true if ADDRESS maps into one of the sections of a
498 OBJF_SHARED objfile of PSPACE and false otherwise. */
500 extern int shared_objfile_contains_address_p (struct program_space *pspace,
503 /* This operation deletes all objfile entries that represent solibs that
504 weren't explicitly loaded by the user, via e.g., the add-symbol-file
507 extern void objfile_purge_solibs (void);
509 /* Functions for dealing with the minimal symbol table, really a misc
510 address<->symbol mapping for things we don't have debug symbols for. */
512 extern int have_minimal_symbols (void);
514 extern struct obj_section *find_pc_section (CORE_ADDR pc);
516 /* Return non-zero if PC is in a section called NAME. */
517 extern int pc_in_section (CORE_ADDR, const char *);
519 /* Return non-zero if PC is in a SVR4-style procedure linkage table
523 in_plt_section (CORE_ADDR pc)
525 return pc_in_section (pc, ".plt");
528 /* Keep a registry of per-objfile data-pointers required by other GDB
530 DECLARE_REGISTRY(objfile);
532 /* In normal use, the section map will be rebuilt by find_pc_section
533 if objfiles have been added, removed or relocated since it was last
534 called. Calling inhibit_section_map_updates will inhibit this
535 behavior until resume_section_map_updates is called. If you call
536 inhibit_section_map_updates you must ensure that every call to
537 find_pc_section in the inhibited region relates to a section that
538 is already in the section map and has not since been removed or
540 extern void inhibit_section_map_updates (struct program_space *pspace);
542 /* Resume automatically rebuilding the section map as required. */
543 extern void resume_section_map_updates (struct program_space *pspace);
545 /* Version of the above suitable for use as a cleanup. */
546 extern void resume_section_map_updates_cleanup (void *arg);
548 extern void default_iterate_over_objfiles_in_search_order
549 (struct gdbarch *gdbarch,
550 iterate_over_objfiles_in_search_order_cb_ftype *cb,
551 void *cb_data, struct objfile *current_objfile);
554 /* Traverse all object files in the current program space.
555 ALL_OBJFILES_SAFE works even if you delete the objfile during the
558 /* Traverse all object files in program space SS. */
560 #define ALL_PSPACE_OBJFILES(ss, obj) \
561 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next)
563 #define ALL_OBJFILES(obj) \
564 for ((obj) = current_program_space->objfiles; \
568 #define ALL_OBJFILES_SAFE(obj,nxt) \
569 for ((obj) = current_program_space->objfiles; \
570 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
573 /* Traverse all symtabs in one objfile. */
575 #define ALL_OBJFILE_FILETABS(objfile, cu, s) \
576 ALL_OBJFILE_COMPUNITS (objfile, cu) \
577 ALL_COMPUNIT_FILETABS (cu, s)
579 /* Traverse all compunits in one objfile. */
581 #define ALL_OBJFILE_COMPUNITS(objfile, cu) \
582 for ((cu) = (objfile) -> compunit_symtabs; (cu) != NULL; (cu) = (cu) -> next)
584 /* Traverse all minimal symbols in one objfile. */
586 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
587 for ((m) = (objfile)->per_bfd->msymbols; \
588 MSYMBOL_LINKAGE_NAME (m) != NULL; \
591 /* Traverse all symtabs in all objfiles in the current symbol
594 #define ALL_FILETABS(objfile, ps, s) \
595 ALL_OBJFILES (objfile) \
596 ALL_OBJFILE_FILETABS (objfile, ps, s)
598 /* Traverse all compunits in all objfiles in the current program space. */
600 #define ALL_COMPUNITS(objfile, cu) \
601 ALL_OBJFILES (objfile) \
602 ALL_OBJFILE_COMPUNITS (objfile, cu)
604 /* Traverse all minimal symbols in all objfiles in the current symbol
607 #define ALL_MSYMBOLS(objfile, m) \
608 ALL_OBJFILES (objfile) \
609 ALL_OBJFILE_MSYMBOLS (objfile, m)
611 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
612 for (osect = objfile->sections; osect < objfile->sections_end; osect++) \
613 if (osect->the_bfd_section == NULL) \
619 /* Traverse all obj_sections in all objfiles in the current program
622 Note that this detects a "break" in the inner loop, and exits
623 immediately from the outer loop as well, thus, client code doesn't
624 need to know that this is implemented with a double for. The extra
625 hair is to make sure that a "break;" stops the outer loop iterating
626 as well, and both OBJFILE and OSECT are left unmodified:
628 - The outer loop learns about the inner loop's end condition, and
629 stops iterating if it detects the inner loop didn't reach its
630 end. In other words, the outer loop keeps going only if the
631 inner loop reached its end cleanly [(osect) ==
632 (objfile)->sections_end].
634 - OSECT is initialized in the outer loop initialization
635 expressions, such as if the inner loop has reached its end, so
636 the check mentioned above succeeds the first time.
638 - The trick to not clearing OBJFILE on a "break;" is, in the outer
639 loop's loop expression, advance OBJFILE, but iff the inner loop
640 reached its end. If not, there was a "break;", so leave OBJFILE
641 as is; the outer loop's conditional will break immediately as
642 well (as OSECT will be different from OBJFILE->sections_end). */
644 #define ALL_OBJSECTIONS(objfile, osect) \
645 for ((objfile) = current_program_space->objfiles, \
646 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
648 && (osect) == (objfile)->sections_end; \
649 ((osect) == (objfile)->sections_end \
650 ? ((objfile) = (objfile)->next, \
651 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
653 ALL_OBJFILE_OSECTIONS (objfile, osect)
655 #define SECT_OFF_DATA(objfile) \
656 ((objfile->sect_index_data == -1) \
657 ? (internal_error (__FILE__, __LINE__, \
658 _("sect_index_data not initialized")), -1) \
659 : objfile->sect_index_data)
661 #define SECT_OFF_RODATA(objfile) \
662 ((objfile->sect_index_rodata == -1) \
663 ? (internal_error (__FILE__, __LINE__, \
664 _("sect_index_rodata not initialized")), -1) \
665 : objfile->sect_index_rodata)
667 #define SECT_OFF_TEXT(objfile) \
668 ((objfile->sect_index_text == -1) \
669 ? (internal_error (__FILE__, __LINE__, \
670 _("sect_index_text not initialized")), -1) \
671 : objfile->sect_index_text)
673 /* Sometimes the .bss section is missing from the objfile, so we don't
674 want to die here. Let the users of SECT_OFF_BSS deal with an
675 uninitialized section index. */
676 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
678 /* Answer whether there is more than one object file loaded. */
680 #define MULTI_OBJFILE_P() (object_files && object_files->next)
682 /* Reset the per-BFD storage area on OBJ. */
684 void set_objfile_per_bfd (struct objfile *obj);
686 /* Return canonical name for OBJFILE.
687 This is the real file name if the file has been opened.
688 Otherwise it is the original name supplied by the user. */
690 const char *objfile_name (const struct objfile *objfile);
692 /* Return the (real) file name of OBJFILE if the file has been opened,
693 otherwise return NULL. */
695 const char *objfile_filename (const struct objfile *objfile);
697 /* Return the name to print for OBJFILE in debugging messages. */
699 extern const char *objfile_debug_name (const struct objfile *objfile);
701 /* Return the name of the file format of OBJFILE if the file has been opened,
702 otherwise return NULL. */
704 const char *objfile_flavour_name (struct objfile *objfile);
706 /* Set the objfile's notion of the "main" name and language. */
708 extern void set_objfile_main_name (struct objfile *objfile,
709 const char *name, enum language lang);
711 extern void objfile_register_static_link
712 (struct objfile *objfile,
713 const struct block *block,
714 const struct dynamic_prop *static_link);
716 extern const struct dynamic_prop *objfile_lookup_static_link
717 (struct objfile *objfile, const struct block *block);
719 #endif /* !defined (OBJFILES_H) */