1 /* Definitions for symbol file management in GDB.
3 Copyright (C) 1992-2014 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)
23 #include "gdb_obstack.h" /* For obstack internals. */
24 #include "symfile.h" /* For struct psymbol_allocation_list. */
25 #include "progspace.h"
34 /* This structure maintains information on a per-objfile basis about the
35 "entry point" of the objfile, and the scope within which the entry point
36 exists. It is possible that gdb will see more than one objfile that is
37 executable, each with its own entry point.
39 For example, for dynamically linked executables in SVR4, the dynamic linker
40 code is contained within the shared C library, which is actually executable
41 and is run by the kernel first when an exec is done of a user executable
42 that is dynamically linked. The dynamic linker within the shared C library
43 then maps in the various program segments in the user executable and jumps
44 to the user executable's recorded entry point, as if the call had been made
45 directly by the kernel.
47 The traditional gdb method of using this info was to use the
48 recorded entry point to set the entry-file's lowpc and highpc from
49 the debugging information, where these values are the starting
50 address (inclusive) and ending address (exclusive) of the
51 instruction space in the executable which correspond to the
52 "startup file", i.e. crt0.o in most cases. This file is assumed to
53 be a startup file and frames with pc's inside it are treated as
54 nonexistent. Setting these variables is necessary so that
55 backtraces do not fly off the bottom of the stack.
57 NOTE: cagney/2003-09-09: It turns out that this "traditional"
58 method doesn't work. Corinna writes: ``It turns out that the call
59 to test for "inside entry file" destroys a meaningful backtrace
60 under some conditions. E.g. the backtrace tests in the asm-source
61 testcase are broken for some targets. In this test the functions
62 are all implemented as part of one file and the testcase is not
63 necessarily linked with a start file (depending on the target).
64 What happens is, that the first frame is printed normaly and
65 following frames are treated as being inside the enttry file then.
66 This way, only the #0 frame is printed in the backtrace output.''
67 Ref "frame.c" "NOTE: vinschen/2003-04-01".
69 Gdb also supports an alternate method to avoid running off the bottom
72 There are two frames that are "special", the frame for the function
73 containing the process entry point, since it has no predecessor frame,
74 and the frame for the function containing the user code entry point
75 (the main() function), since all the predecessor frames are for the
76 process startup code. Since we have no guarantee that the linked
77 in startup modules have any debugging information that gdb can use,
78 we need to avoid following frame pointers back into frames that might
79 have been built in the startup code, as we might get hopelessly
80 confused. However, we almost always have debugging information
83 These variables are used to save the range of PC values which are
84 valid within the main() function and within the function containing
85 the process entry point. If we always consider the frame for
86 main() as the outermost frame when debugging user code, and the
87 frame for the process entry point function as the outermost frame
88 when debugging startup code, then all we have to do is have
89 DEPRECATED_FRAME_CHAIN_VALID return false whenever a frame's
90 current PC is within the range specified by these variables. In
91 essence, we set "ceilings" in the frame chain beyond which we will
92 not proceed when following the frame chain back up the stack.
94 A nice side effect is that we can still debug startup code without
95 running off the end of the frame chain, assuming that we have usable
96 debugging information in the startup modules, and if we choose to not
97 use the block at main, or can't find it for some reason, everything
98 still works as before. And if we have no startup code debugging
99 information but we do have usable information for main(), backtraces
100 from user code don't go wandering off into the startup code. */
104 /* The unrelocated value we should use for this objfile entry point. */
105 CORE_ADDR entry_point;
107 /* The index of the section in which the entry point appears. */
108 int the_bfd_section_index;
110 /* Set to 1 iff ENTRY_POINT contains a valid value. */
111 unsigned entry_point_p : 1;
113 /* Set to 1 iff this object was initialized. */
114 unsigned initialized : 1;
117 /* Sections in an objfile. The section offsets are stored in the
122 struct bfd_section *the_bfd_section; /* BFD section pointer */
124 /* Objfile this section is part of. */
125 struct objfile *objfile;
127 /* True if this "overlay section" is mapped into an "overlay region". */
131 /* Relocation offset applied to S. */
132 #define obj_section_offset(s) \
133 (((s)->objfile->section_offsets)->offsets[gdb_bfd_section_index ((s)->objfile->obfd, (s)->the_bfd_section)])
135 /* The memory address of section S (vma + offset). */
136 #define obj_section_addr(s) \
137 (bfd_get_section_vma ((s)->objfile->obfd, s->the_bfd_section) \
138 + obj_section_offset (s))
140 /* The one-passed-the-end memory address of section S
141 (vma + size + offset). */
142 #define obj_section_endaddr(s) \
143 (bfd_get_section_vma ((s)->objfile->obfd, s->the_bfd_section) \
144 + bfd_get_section_size ((s)->the_bfd_section) \
145 + obj_section_offset (s))
147 /* The "objstats" structure provides a place for gdb to record some
148 interesting information about its internal state at runtime, on a
149 per objfile basis, such as information about the number of symbols
150 read, size of string table (if any), etc. */
154 int n_minsyms; /* Number of minimal symbols read */
155 int n_psyms; /* Number of partial symbols read */
156 int n_syms; /* Number of full symbols read */
157 int n_stabs; /* Number of ".stabs" read (if applicable) */
158 int n_types; /* Number of types */
159 int sz_strtab; /* Size of stringtable, (if applicable) */
162 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
163 #define OBJSTATS struct objstats stats
164 extern void print_objfile_statistics (void);
165 extern void print_symbol_bcache_statistics (void);
167 /* Number of entries in the minimal symbol hash table. */
168 #define MINIMAL_SYMBOL_HASH_SIZE 2039
170 /* Some objfile data is hung off the BFD. This enables sharing of the
171 data across all objfiles using the BFD. The data is stored in an
172 instance of this structure, and associated with the BFD using the
175 struct objfile_per_bfd_storage
177 /* The storage has an obstack of its own. */
179 struct obstack storage_obstack;
181 /* Byte cache for file names. */
183 struct bcache *filename_cache;
185 /* Byte cache for macros. */
186 struct bcache *macro_cache;
188 /* The gdbarch associated with the BFD. Note that this gdbarch is
189 determined solely from BFD information, without looking at target
190 information. The gdbarch determined from a running target may
191 differ from this e.g. with respect to register types and names. */
193 struct gdbarch *gdbarch;
195 /* Hash table for mapping symbol names to demangled names. Each
196 entry in the hash table is actually two consecutive strings,
197 both null-terminated; the first one is a mangled or linkage
198 name, and the second is the demangled name or just a zero byte
199 if the name doesn't demangle. */
200 struct htab *demangled_names_hash;
202 /* The per-objfile information about the entry point, the scope (file/func)
203 containing the entry point, and the scope of the user's main() func. */
205 struct entry_info ei;
208 /* Master structure for keeping track of each file from which
209 gdb reads symbols. There are several ways these get allocated: 1.
210 The main symbol file, symfile_objfile, set by the symbol-file command,
211 2. Additional symbol files added by the add-symbol-file command,
212 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
213 for modules that were loaded when GDB attached to a remote system
214 (see remote-vx.c). */
219 /* All struct objfile's are chained together by their next pointers.
220 The program space field "objfiles" (frequently referenced via
221 the macro "object_files") points to the first link in this
224 struct objfile *next;
226 /* The object file's original name as specified by the user,
227 made absolute, and tilde-expanded. However, it is not canonicalized
228 (i.e., it has not been passed through gdb_realpath).
229 This pointer is never NULL. This does not have to be freed; it is
230 guaranteed to have a lifetime at least as long as the objfile. */
236 /* Some flag bits for this objfile.
237 The values are defined by OBJF_*. */
239 unsigned short flags;
241 /* The program space associated with this objfile. */
243 struct program_space *pspace;
245 /* Each objfile points to a linked list of symtabs derived from this file,
246 one symtab structure for each compilation unit (source file). Each link
247 in the symtab list contains a backpointer to this objfile. */
249 struct symtab *symtabs;
251 /* Each objfile points to a linked list of partial symtabs derived from
252 this file, one partial symtab structure for each compilation unit
255 struct partial_symtab *psymtabs;
257 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
258 have a map per the whole process but ADDRMAP cannot selectively remove
259 its items during FREE_OBJFILE. This mapping is already present even for
260 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
262 struct addrmap *psymtabs_addrmap;
264 /* List of freed partial symtabs, available for re-use. */
266 struct partial_symtab *free_psymtabs;
268 /* The object file's BFD. Can be null if the objfile contains only
269 minimal symbols, e.g. the run time common symbols for SunOS4. */
273 /* The per-BFD data. Note that this is treated specially if OBFD
276 struct objfile_per_bfd_storage *per_bfd;
278 /* The modification timestamp of the object file, as of the last time
279 we read its symbols. */
283 /* Obstack to hold objects that should be freed when we load a new symbol
284 table from this object file. */
286 struct obstack objfile_obstack;
288 /* A byte cache where we can stash arbitrary "chunks" of bytes that
291 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
293 /* Vectors of all partial symbols read in from file. The actual data
294 is stored in the objfile_obstack. */
296 struct psymbol_allocation_list global_psymbols;
297 struct psymbol_allocation_list static_psymbols;
299 /* Each file contains a pointer to an array of minimal symbols for all
300 global symbols that are defined within the file. The array is
301 terminated by a "null symbol", one that has a NULL pointer for the
302 name and a zero value for the address. This makes it easy to walk
303 through the array when passed a pointer to somewhere in the middle
304 of it. There is also a count of the number of symbols, which does
305 not include the terminating null symbol. The array itself, as well
306 as all the data that it points to, should be allocated on the
307 objfile_obstack for this file. */
309 struct minimal_symbol *msymbols;
310 int minimal_symbol_count;
312 /* This is a hash table used to index the minimal symbols by name. */
314 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
316 /* This hash table is used to index the minimal symbols by their
319 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
321 /* Structure which keeps track of functions that manipulate objfile's
322 of the same type as this objfile. I.e. the function to read partial
323 symbols for example. Note that this structure is in statically
324 allocated memory, and is shared by all objfiles that use the
325 object module reader of this type. */
327 const struct sym_fns *sf;
329 /* Per objfile data-pointers required by other GDB modules. */
333 /* Set of relocation offsets to apply to each section.
334 The table is indexed by the_bfd_section->index, thus it is generally
335 as large as the number of sections in the binary.
336 The table is stored on the objfile_obstack.
338 These offsets indicate that all symbols (including partial and
339 minimal symbols) which have been read have been relocated by this
340 much. Symbols which are yet to be read need to be relocated by it. */
342 struct section_offsets *section_offsets;
345 /* Indexes in the section_offsets array. These are initialized by the
346 *_symfile_offsets() family of functions (som_symfile_offsets,
347 xcoff_symfile_offsets, default_symfile_offsets). In theory they
348 should correspond to the section indexes used by bfd for the
349 current objfile. The exception to this for the time being is the
355 int sect_index_rodata;
357 /* These pointers are used to locate the section table, which
358 among other things, is used to map pc addresses into sections.
359 SECTIONS points to the first entry in the table, and
360 SECTIONS_END points to the first location past the last entry
361 in the table. The table is stored on the objfile_obstack. The
362 sections are indexed by the BFD section index; but the
363 structure data is only valid for certain sections
364 (e.g. non-empty, SEC_ALLOC). */
366 struct obj_section *sections, *sections_end;
368 /* GDB allows to have debug symbols in separate object files. This is
369 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
370 Although this is a tree structure, GDB only support one level
371 (ie a separate debug for a separate debug is not supported). Note that
372 separate debug object are in the main chain and therefore will be
373 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
374 has a non-nul separate_debug_objfile_backlink. */
376 /* Link to the first separate debug object, if any. */
377 struct objfile *separate_debug_objfile;
379 /* If this is a separate debug object, this is used as a link to the
380 actual executable objfile. */
381 struct objfile *separate_debug_objfile_backlink;
383 /* If this is a separate debug object, this is a link to the next one
384 for the same executable objfile. */
385 struct objfile *separate_debug_objfile_link;
387 /* Place to stash various statistics about this objfile. */
390 /* A linked list of symbols created when reading template types or
391 function templates. These symbols are not stored in any symbol
392 table, so we have to keep them here to relocate them
394 struct symbol *template_symbols;
397 /* Defines for the objfile flag word. */
399 /* When an object file has its functions reordered (currently Irix-5.2
400 shared libraries exhibit this behaviour), we will need an expensive
401 algorithm to locate a partial symtab or symtab via an address.
402 To avoid this penalty for normal object files, we use this flag,
403 whose setting is determined upon symbol table read in. */
405 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
407 /* Distinguish between an objfile for a shared library and a "vanilla"
408 objfile. (If not set, the objfile may still actually be a solib.
409 This can happen if the user created the objfile by using the
410 add-symbol-file command. GDB doesn't in that situation actually
411 check whether the file is a solib. Rather, the target's
412 implementation of the solib interface is responsible for setting
413 this flag when noticing solibs used by an inferior.) */
415 #define OBJF_SHARED (1 << 1) /* From a shared library */
417 /* User requested that this objfile be read in it's entirety. */
419 #define OBJF_READNOW (1 << 2) /* Immediate full read */
421 /* This objfile was created because the user explicitly caused it
422 (e.g., used the add-symbol-file command). This bit offers a way
423 for run_command to remove old objfile entries which are no longer
424 valid (i.e., are associated with an old inferior), but to preserve
425 ones that the user explicitly loaded via the add-symbol-file
428 #define OBJF_USERLOADED (1 << 3) /* User loaded */
430 /* Set if we have tried to read partial symtabs for this objfile.
431 This is used to allow lazy reading of partial symtabs. */
433 #define OBJF_PSYMTABS_READ (1 << 4)
435 /* Set if this is the main symbol file
436 (as opposed to symbol file for dynamically loaded code). */
438 #define OBJF_MAINLINE (1 << 5)
440 /* ORIGINAL_NAME and OBFD->FILENAME correspond to text description unrelated to
441 filesystem names. It can be for example "<image in memory>". */
443 #define OBJF_NOT_FILENAME (1 << 6)
445 /* Declarations for functions defined in objfiles.c */
447 extern struct objfile *allocate_objfile (bfd *, const char *name, int);
449 extern struct gdbarch *get_objfile_arch (struct objfile *);
451 extern int entry_point_address_query (CORE_ADDR *entry_p);
453 extern CORE_ADDR entry_point_address (void);
455 extern void build_objfile_section_table (struct objfile *);
457 extern void terminate_minimal_symbol_table (struct objfile *objfile);
459 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
460 const struct objfile *);
462 extern void put_objfile_before (struct objfile *, struct objfile *);
464 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
466 extern void unlink_objfile (struct objfile *);
468 extern void free_objfile (struct objfile *);
470 extern void free_objfile_separate_debug (struct objfile *);
472 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
474 extern void free_all_objfiles (void);
476 extern void objfile_relocate (struct objfile *, const struct section_offsets *);
477 extern void objfile_rebase (struct objfile *, CORE_ADDR);
479 extern int objfile_has_partial_symbols (struct objfile *objfile);
481 extern int objfile_has_full_symbols (struct objfile *objfile);
483 extern int objfile_has_symbols (struct objfile *objfile);
485 extern int have_partial_symbols (void);
487 extern int have_full_symbols (void);
489 extern void objfile_set_sym_fns (struct objfile *objfile,
490 const struct sym_fns *sf);
492 extern void objfiles_changed (void);
494 extern int is_addr_in_objfile (CORE_ADDR addr, const struct objfile *objfile);
496 /* This operation deletes all objfile entries that represent solibs that
497 weren't explicitly loaded by the user, via e.g., the add-symbol-file
500 extern void objfile_purge_solibs (void);
502 /* Functions for dealing with the minimal symbol table, really a misc
503 address<->symbol mapping for things we don't have debug symbols for. */
505 extern int have_minimal_symbols (void);
507 extern struct obj_section *find_pc_section (CORE_ADDR pc);
509 /* Return non-zero if PC is in a section called NAME. */
510 extern int pc_in_section (CORE_ADDR, char *);
512 /* Return non-zero if PC is in a SVR4-style procedure linkage table
516 in_plt_section (CORE_ADDR pc)
518 return pc_in_section (pc, ".plt");
521 /* Keep a registry of per-objfile data-pointers required by other GDB
523 DECLARE_REGISTRY(objfile);
525 /* In normal use, the section map will be rebuilt by find_pc_section
526 if objfiles have been added, removed or relocated since it was last
527 called. Calling inhibit_section_map_updates will inhibit this
528 behavior until resume_section_map_updates is called. If you call
529 inhibit_section_map_updates you must ensure that every call to
530 find_pc_section in the inhibited region relates to a section that
531 is already in the section map and has not since been removed or
533 extern void inhibit_section_map_updates (struct program_space *pspace);
535 /* Resume automatically rebuilding the section map as required. */
536 extern void resume_section_map_updates (struct program_space *pspace);
538 /* Version of the above suitable for use as a cleanup. */
539 extern void resume_section_map_updates_cleanup (void *arg);
541 extern void default_iterate_over_objfiles_in_search_order
542 (struct gdbarch *gdbarch,
543 iterate_over_objfiles_in_search_order_cb_ftype *cb,
544 void *cb_data, struct objfile *current_objfile);
547 /* Traverse all object files in the current program space.
548 ALL_OBJFILES_SAFE works even if you delete the objfile during the
551 /* Traverse all object files in program space SS. */
553 #define ALL_PSPACE_OBJFILES(ss, obj) \
554 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next)
556 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
557 for ((obj) = ss->objfiles; \
558 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
561 #define ALL_OBJFILES(obj) \
562 for ((obj) = current_program_space->objfiles; \
566 #define ALL_OBJFILES_SAFE(obj,nxt) \
567 for ((obj) = current_program_space->objfiles; \
568 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
571 /* Traverse all symtabs in one objfile. */
573 #define ALL_OBJFILE_SYMTABS(objfile, s) \
574 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
576 /* Traverse all primary symtabs in one objfile. */
578 #define ALL_OBJFILE_PRIMARY_SYMTABS(objfile, s) \
579 ALL_OBJFILE_SYMTABS ((objfile), (s)) \
582 /* Traverse all minimal symbols in one objfile. */
584 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
585 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
587 /* Traverse all symtabs in all objfiles in the current symbol
590 #define ALL_SYMTABS(objfile, s) \
591 ALL_OBJFILES (objfile) \
592 ALL_OBJFILE_SYMTABS (objfile, s)
594 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
595 ALL_PSPACE_OBJFILES (ss, objfile) \
596 ALL_OBJFILE_SYMTABS (objfile, s)
598 /* Traverse all symtabs in all objfiles in the current program space,
599 skipping included files (which share a blockvector with their
602 #define ALL_PRIMARY_SYMTABS(objfile, s) \
603 ALL_OBJFILES (objfile) \
604 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
606 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
607 ALL_PSPACE_OBJFILES (ss, objfile) \
608 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
610 /* Traverse all minimal symbols in all objfiles in the current symbol
613 #define ALL_MSYMBOLS(objfile, m) \
614 ALL_OBJFILES (objfile) \
615 ALL_OBJFILE_MSYMBOLS (objfile, m)
617 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
618 for (osect = objfile->sections; osect < objfile->sections_end; osect++) \
619 if (osect->the_bfd_section == NULL) \
625 /* Traverse all obj_sections in all objfiles in the current program
628 Note that this detects a "break" in the inner loop, and exits
629 immediately from the outer loop as well, thus, client code doesn't
630 need to know that this is implemented with a double for. The extra
631 hair is to make sure that a "break;" stops the outer loop iterating
632 as well, and both OBJFILE and OSECT are left unmodified:
634 - The outer loop learns about the inner loop's end condition, and
635 stops iterating if it detects the inner loop didn't reach its
636 end. In other words, the outer loop keeps going only if the
637 inner loop reached its end cleanly [(osect) ==
638 (objfile)->sections_end].
640 - OSECT is initialized in the outer loop initialization
641 expressions, such as if the inner loop has reached its end, so
642 the check mentioned above succeeds the first time.
644 - The trick to not clearing OBJFILE on a "break;" is, in the outer
645 loop's loop expression, advance OBJFILE, but iff the inner loop
646 reached its end. If not, there was a "break;", so leave OBJFILE
647 as is; the outer loop's conditional will break immediately as
648 well (as OSECT will be different from OBJFILE->sections_end). */
650 #define ALL_OBJSECTIONS(objfile, osect) \
651 for ((objfile) = current_program_space->objfiles, \
652 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
654 && (osect) == (objfile)->sections_end; \
655 ((osect) == (objfile)->sections_end \
656 ? ((objfile) = (objfile)->next, \
657 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
659 ALL_OBJFILE_OSECTIONS (objfile, osect)
661 #define SECT_OFF_DATA(objfile) \
662 ((objfile->sect_index_data == -1) \
663 ? (internal_error (__FILE__, __LINE__, \
664 _("sect_index_data not initialized")), -1) \
665 : objfile->sect_index_data)
667 #define SECT_OFF_RODATA(objfile) \
668 ((objfile->sect_index_rodata == -1) \
669 ? (internal_error (__FILE__, __LINE__, \
670 _("sect_index_rodata not initialized")), -1) \
671 : objfile->sect_index_rodata)
673 #define SECT_OFF_TEXT(objfile) \
674 ((objfile->sect_index_text == -1) \
675 ? (internal_error (__FILE__, __LINE__, \
676 _("sect_index_text not initialized")), -1) \
677 : objfile->sect_index_text)
679 /* Sometimes the .bss section is missing from the objfile, so we don't
680 want to die here. Let the users of SECT_OFF_BSS deal with an
681 uninitialized section index. */
682 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
684 /* Answer whether there is more than one object file loaded. */
686 #define MULTI_OBJFILE_P() (object_files && object_files->next)
688 /* Reset the per-BFD storage area on OBJ. */
690 void set_objfile_per_bfd (struct objfile *obj);
692 const char *objfile_name (const struct objfile *objfile);
694 #endif /* !defined (OBJFILES_H) */