1 /* Definitions for symbol file management in GDB.
3 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001,
4 2002, 2003, 2004, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 This file is part of GDB.
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.
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.
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/>. */
22 #if !defined (OBJFILES_H)
25 #include "gdb_obstack.h" /* For obstack internals. */
26 #include "symfile.h" /* For struct psymbol_allocation_list. */
27 #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 relocated value we should use for this objfile entry point. */
105 CORE_ADDR entry_point;
107 /* Set to 1 iff ENTRY_POINT contains a valid value. */
108 unsigned entry_point_p : 1;
111 /* Sections in an objfile. The section offsets are stored in the
116 struct bfd_section *the_bfd_section; /* BFD section pointer */
118 /* Objfile this section is part of. */
119 struct objfile *objfile;
121 /* True if this "overlay section" is mapped into an "overlay region". */
125 /* Relocation offset applied to S. */
126 #define obj_section_offset(s) \
127 (((s)->objfile->section_offsets)->offsets[(s)->the_bfd_section->index])
129 /* The memory address of section S (vma + offset). */
130 #define obj_section_addr(s) \
131 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \
132 + obj_section_offset (s))
134 /* The one-passed-the-end memory address of section S
135 (vma + size + offset). */
136 #define obj_section_endaddr(s) \
137 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \
138 + bfd_get_section_size ((s)->the_bfd_section) \
139 + obj_section_offset (s))
141 /* The "objstats" structure provides a place for gdb to record some
142 interesting information about its internal state at runtime, on a
143 per objfile basis, such as information about the number of symbols
144 read, size of string table (if any), etc. */
148 int n_minsyms; /* Number of minimal symbols read */
149 int n_psyms; /* Number of partial symbols read */
150 int n_syms; /* Number of full symbols read */
151 int n_stabs; /* Number of ".stabs" read (if applicable) */
152 int n_types; /* Number of types */
153 int sz_strtab; /* Size of stringtable, (if applicable) */
156 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
157 #define OBJSTATS struct objstats stats
158 extern void print_objfile_statistics (void);
159 extern void print_symbol_bcache_statistics (void);
161 /* Number of entries in the minimal symbol hash table. */
162 #define MINIMAL_SYMBOL_HASH_SIZE 2039
164 /* Master structure for keeping track of each file from which
165 gdb reads symbols. There are several ways these get allocated: 1.
166 The main symbol file, symfile_objfile, set by the symbol-file command,
167 2. Additional symbol files added by the add-symbol-file command,
168 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
169 for modules that were loaded when GDB attached to a remote system
170 (see remote-vx.c). */
175 /* All struct objfile's are chained together by their next pointers.
176 The global variable "object_files" points to the first link in this
179 FIXME: There is a problem here if the objfile is reusable, and if
180 multiple users are to be supported. The problem is that the objfile
181 list is linked through a member of the objfile struct itself, which
182 is only valid for one gdb process. The list implementation needs to
183 be changed to something like:
185 struct list {struct list *next; struct objfile *objfile};
187 where the list structure is completely maintained separately within
190 struct objfile *next;
192 /* The object file's name, tilde-expanded and absolute. Malloc'd; free it
193 if you free this struct. This pointer is never NULL. */
197 /* Some flag bits for this objfile. */
199 unsigned short flags;
201 /* The program space associated with this objfile. */
203 struct program_space *pspace;
205 /* Each objfile points to a linked list of symtabs derived from this file,
206 one symtab structure for each compilation unit (source file). Each link
207 in the symtab list contains a backpointer to this objfile. */
209 struct symtab *symtabs;
211 /* Each objfile points to a linked list of partial symtabs derived from
212 this file, one partial symtab structure for each compilation unit
215 struct partial_symtab *psymtabs;
217 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
218 have a map per the whole process but ADDRMAP cannot selectively remove
219 its items during FREE_OBJFILE. This mapping is already present even for
220 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
222 struct addrmap *psymtabs_addrmap;
224 /* List of freed partial symtabs, available for re-use. */
226 struct partial_symtab *free_psymtabs;
228 /* The object file's BFD. Can be null if the objfile contains only
229 minimal symbols, e.g. the run time common symbols for SunOS4. */
233 /* The gdbarch associated with the BFD. Note that this gdbarch is
234 determined solely from BFD information, without looking at target
235 information. The gdbarch determined from a running target may
236 differ from this e.g. with respect to register types and names. */
238 struct gdbarch *gdbarch;
240 /* The modification timestamp of the object file, as of the last time
241 we read its symbols. */
245 /* Obstack to hold objects that should be freed when we load a new symbol
246 table from this object file. */
248 struct obstack objfile_obstack;
250 /* A byte cache where we can stash arbitrary "chunks" of bytes that
253 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
254 struct bcache *macro_cache; /* Byte cache for macros. */
255 struct bcache *filename_cache; /* Byte cache for file names. */
257 /* Hash table for mapping symbol names to demangled names. Each
258 entry in the hash table is actually two consecutive strings,
259 both null-terminated; the first one is a mangled or linkage
260 name, and the second is the demangled name or just a zero byte
261 if the name doesn't demangle. */
262 struct htab *demangled_names_hash;
264 /* Vectors of all partial symbols read in from file. The actual data
265 is stored in the objfile_obstack. */
267 struct psymbol_allocation_list global_psymbols;
268 struct psymbol_allocation_list static_psymbols;
270 /* Each file contains a pointer to an array of minimal symbols for all
271 global symbols that are defined within the file. The array is
272 terminated by a "null symbol", one that has a NULL pointer for the
273 name and a zero value for the address. This makes it easy to walk
274 through the array when passed a pointer to somewhere in the middle
275 of it. There is also a count of the number of symbols, which does
276 not include the terminating null symbol. The array itself, as well
277 as all the data that it points to, should be allocated on the
278 objfile_obstack for this file. */
280 struct minimal_symbol *msymbols;
281 int minimal_symbol_count;
283 /* This is a hash table used to index the minimal symbols by name. */
285 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
287 /* This hash table is used to index the minimal symbols by their
290 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
292 /* Structure which keeps track of functions that manipulate objfile's
293 of the same type as this objfile. I.e. the function to read partial
294 symbols for example. Note that this structure is in statically
295 allocated memory, and is shared by all objfiles that use the
296 object module reader of this type. */
298 const struct sym_fns *sf;
300 /* The per-objfile information about the entry point, the scope (file/func)
301 containing the entry point, and the scope of the user's main() func. */
303 struct entry_info ei;
305 /* Information about stabs. Will be filled in with a dbx_symfile_info
306 struct by those readers that need it. */
307 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
308 data points implemented using "data" and "num_data" below. For
309 an example of how to use this replacement, see "objfile_data"
312 struct dbx_symfile_info *deprecated_sym_stab_info;
314 /* Hook for information for use by the symbol reader (currently used
315 for information shared by sym_init and sym_read). It is
316 typically a pointer to malloc'd memory. The symbol reader's finish
317 function is responsible for freeing the memory thusly allocated. */
318 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
319 data points implemented using "data" and "num_data" below. For
320 an example of how to use this replacement, see "objfile_data"
323 void *deprecated_sym_private;
325 /* Per objfile data-pointers required by other GDB modules. */
326 /* FIXME: kettenis/20030711: This mechanism could replace
327 deprecated_sym_stab_info and deprecated_sym_private
333 /* Set of relocation offsets to apply to each section.
334 Currently on the objfile_obstack (which makes no sense, but I'm
335 not sure it's harming anything).
337 These offsets indicate that all symbols (including partial and
338 minimal symbols) which have been read have been relocated by this
339 much. Symbols which are yet to be read need to be relocated by
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. Currently the table is stored on the
362 objfile_obstack (which makes no sense, but I'm not sure it's
363 harming anything). */
366 *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 symtab that the C++ code uses to stash special symbols
391 associated to namespaces. */
393 /* FIXME/carlton-2003-06-27: Delete this in a few years once
394 "possible namespace symbols" go away. */
395 struct symtab *cp_namespace_symtab;
397 /* A linked list of symbols created when reading template types or
398 function templates. These symbols are not stored in any symbol
399 table, so we have to keep them here to relocate them
401 struct symbol *template_symbols;
404 /* Defines for the objfile flag word. */
406 /* When an object file has its functions reordered (currently Irix-5.2
407 shared libraries exhibit this behaviour), we will need an expensive
408 algorithm to locate a partial symtab or symtab via an address.
409 To avoid this penalty for normal object files, we use this flag,
410 whose setting is determined upon symbol table read in. */
412 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
414 /* Distinguish between an objfile for a shared library and a "vanilla"
415 objfile. (If not set, the objfile may still actually be a solib.
416 This can happen if the user created the objfile by using the
417 add-symbol-file command. GDB doesn't in that situation actually
418 check whether the file is a solib. Rather, the target's
419 implementation of the solib interface is responsible for setting
420 this flag when noticing solibs used by an inferior.) */
422 #define OBJF_SHARED (1 << 1) /* From a shared library */
424 /* User requested that this objfile be read in it's entirety. */
426 #define OBJF_READNOW (1 << 2) /* Immediate full read */
428 /* This objfile was created because the user explicitly caused it
429 (e.g., used the add-symbol-file command). This bit offers a way
430 for run_command to remove old objfile entries which are no longer
431 valid (i.e., are associated with an old inferior), but to preserve
432 ones that the user explicitly loaded via the add-symbol-file
435 #define OBJF_USERLOADED (1 << 3) /* User loaded */
437 /* The object file that contains the runtime common minimal symbols
438 for SunOS4. Note that this objfile has no associated BFD. */
440 extern struct objfile *rt_common_objfile;
442 /* When we need to allocate a new type, we need to know which objfile_obstack
443 to allocate the type on, since there is one for each objfile. The places
444 where types are allocated are deeply buried in function call hierarchies
445 which know nothing about objfiles, so rather than trying to pass a
446 particular objfile down to them, we just do an end run around them and
447 set current_objfile to be whatever objfile we expect to be using at the
448 time types are being allocated. For instance, when we start reading
449 symbols for a particular objfile, we set current_objfile to point to that
450 objfile, and when we are done, we set it back to NULL, to ensure that we
451 never put a type someplace other than where we are expecting to put it.
452 FIXME: Maybe we should review the entire type handling system and
453 see if there is a better way to avoid this problem. */
455 extern struct objfile *current_objfile;
457 /* Declarations for functions defined in objfiles.c */
459 extern struct objfile *allocate_objfile (bfd *, int);
461 extern struct gdbarch *get_objfile_arch (struct objfile *);
463 extern void init_entry_point_info (struct objfile *);
465 extern int entry_point_address_query (CORE_ADDR *entry_p);
467 extern CORE_ADDR entry_point_address (void);
469 extern int build_objfile_section_table (struct objfile *);
471 extern void terminate_minimal_symbol_table (struct objfile *objfile);
473 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
474 const struct objfile *);
476 extern void put_objfile_before (struct objfile *, struct objfile *);
478 extern void objfile_to_front (struct objfile *);
480 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
482 extern void unlink_objfile (struct objfile *);
484 extern void free_objfile (struct objfile *);
486 extern void free_objfile_separate_debug (struct objfile *);
488 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
490 extern void free_all_objfiles (void);
492 extern void objfile_relocate (struct objfile *, struct section_offsets *);
494 extern int objfile_has_partial_symbols (struct objfile *objfile);
496 extern int objfile_has_full_symbols (struct objfile *objfile);
498 extern int objfile_has_symbols (struct objfile *objfile);
500 extern int have_partial_symbols (void);
502 extern int have_full_symbols (void);
504 extern void objfiles_changed (void);
506 /* This operation deletes all objfile entries that represent solibs that
507 weren't explicitly loaded by the user, via e.g., the add-symbol-file
510 extern void objfile_purge_solibs (void);
512 /* Functions for dealing with the minimal symbol table, really a misc
513 address<->symbol mapping for things we don't have debug symbols for. */
515 extern int have_minimal_symbols (void);
517 extern struct obj_section *find_pc_section (CORE_ADDR pc);
519 extern int in_plt_section (CORE_ADDR, char *);
521 /* Keep a registry of per-objfile data-pointers required by other GDB
524 /* Allocate an entry in the per-objfile registry. */
525 extern const struct objfile_data *register_objfile_data (void);
527 /* Allocate an entry in the per-objfile registry.
528 SAVE and FREE are called when clearing objfile data.
529 First all registered SAVE functions are called.
530 Then all registered FREE functions are called.
531 Either or both of SAVE, FREE may be NULL. */
532 extern const struct objfile_data *register_objfile_data_with_cleanup
533 (void (*save) (struct objfile *, void *),
534 void (*free) (struct objfile *, void *));
536 extern void clear_objfile_data (struct objfile *objfile);
537 extern void set_objfile_data (struct objfile *objfile,
538 const struct objfile_data *data, void *value);
539 extern void *objfile_data (struct objfile *objfile,
540 const struct objfile_data *data);
542 extern struct bfd *gdb_bfd_ref (struct bfd *abfd);
543 extern void gdb_bfd_unref (struct bfd *abfd);
544 extern int gdb_bfd_close_or_warn (struct bfd *abfd);
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 minimal symbols in one objfile. */
578 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
579 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
581 /* Traverse all symtabs in all objfiles in the current symbol
584 #define ALL_SYMTABS(objfile, s) \
585 ALL_OBJFILES (objfile) \
586 ALL_OBJFILE_SYMTABS (objfile, s)
588 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
589 ALL_PSPACE_OBJFILES (ss, objfile) \
590 ALL_OBJFILE_SYMTABS (objfile, s)
592 /* Traverse all symtabs in all objfiles in the current program space,
593 skipping included files (which share a blockvector with their
596 #define ALL_PRIMARY_SYMTABS(objfile, s) \
597 ALL_OBJFILES (objfile) \
598 ALL_OBJFILE_SYMTABS (objfile, s) \
601 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
602 ALL_PSPACE_OBJFILES (ss, objfile) \
603 ALL_OBJFILE_SYMTABS (objfile, s) \
606 /* Traverse all minimal symbols in all objfiles in the current symbol
609 #define ALL_MSYMBOLS(objfile, m) \
610 ALL_OBJFILES (objfile) \
611 ALL_OBJFILE_MSYMBOLS (objfile, m)
613 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
614 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
616 /* Traverse all obj_sections in all objfiles in the current program
619 Note that this detects a "break" in the inner loop, and exits
620 immediately from the outer loop as well, thus, client code doesn't
621 need to know that this is implemented with a double for. The extra
622 hair is to make sure that a "break;" stops the outer loop iterating
623 as well, and both OBJFILE and OSECT are left unmodified:
625 - The outer loop learns about the inner loop's end condition, and
626 stops iterating if it detects the inner loop didn't reach its
627 end. In other words, the outer loop keeps going only if the
628 inner loop reached its end cleanly [(osect) ==
629 (objfile)->sections_end].
631 - OSECT is initialized in the outer loop initialization
632 expressions, such as if the inner loop has reached its end, so
633 the check mentioned above succeeds the first time.
635 - The trick to not clearing OBJFILE on a "break;" is, in the outer
636 loop's loop expression, advance OBJFILE, but iff the inner loop
637 reached its end. If not, there was a "break;", so leave OBJFILE
638 as is; the outer loop's conditional will break immediately as
639 well (as OSECT will be different from OBJFILE->sections_end). */
641 #define ALL_OBJSECTIONS(objfile, osect) \
642 for ((objfile) = current_program_space->objfiles, \
643 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
645 && (osect) == (objfile)->sections_end; \
646 ((osect) == (objfile)->sections_end \
647 ? ((objfile) = (objfile)->next, \
648 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
650 for ((osect) = (objfile)->sections; \
651 (osect) < (objfile)->sections_end; \
654 #define SECT_OFF_DATA(objfile) \
655 ((objfile->sect_index_data == -1) \
656 ? (internal_error (__FILE__, __LINE__, \
657 _("sect_index_data not initialized")), -1) \
658 : objfile->sect_index_data)
660 #define SECT_OFF_RODATA(objfile) \
661 ((objfile->sect_index_rodata == -1) \
662 ? (internal_error (__FILE__, __LINE__, \
663 _("sect_index_rodata not initialized")), -1) \
664 : objfile->sect_index_rodata)
666 #define SECT_OFF_TEXT(objfile) \
667 ((objfile->sect_index_text == -1) \
668 ? (internal_error (__FILE__, __LINE__, \
669 _("sect_index_text not initialized")), -1) \
670 : objfile->sect_index_text)
672 /* Sometimes the .bss section is missing from the objfile, so we don't
673 want to die here. Let the users of SECT_OFF_BSS deal with an
674 uninitialized section index. */
675 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
677 /* Answer whether there is more than one object file loaded. */
679 #define MULTI_OBJFILE_P() (object_files && object_files->next)
681 #endif /* !defined (OBJFILES_H) */