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. */
199 /* Some flag bits for this objfile. */
201 unsigned short flags;
203 /* The program space associated with this objfile. */
205 struct program_space *pspace;
207 /* Each objfile points to a linked list of symtabs derived from this file,
208 one symtab structure for each compilation unit (source file). Each link
209 in the symtab list contains a backpointer to this objfile. */
211 struct symtab *symtabs;
213 /* Each objfile points to a linked list of partial symtabs derived from
214 this file, one partial symtab structure for each compilation unit
217 struct partial_symtab *psymtabs;
219 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
220 have a map per the whole process but ADDRMAP cannot selectively remove
221 its items during FREE_OBJFILE. This mapping is already present even for
222 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
224 struct addrmap *psymtabs_addrmap;
226 /* List of freed partial symtabs, available for re-use. */
228 struct partial_symtab *free_psymtabs;
230 /* The object file's BFD. Can be null if the objfile contains only
231 minimal symbols, e.g. the run time common symbols for SunOS4. */
235 /* The gdbarch associated with the BFD. Note that this gdbarch is
236 determined solely from BFD information, without looking at target
237 information. The gdbarch determined from a running target may
238 differ from this e.g. with respect to register types and names. */
240 struct gdbarch *gdbarch;
242 /* The modification timestamp of the object file, as of the last time
243 we read its symbols. */
247 /* Obstack to hold objects that should be freed when we load a new symbol
248 table from this object file. */
250 struct obstack objfile_obstack;
252 /* A byte cache where we can stash arbitrary "chunks" of bytes that
255 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
256 struct bcache *macro_cache; /* Byte cache for macros. */
257 struct bcache *filename_cache; /* Byte cache for file names. */
259 /* Hash table for mapping symbol names to demangled names. Each
260 entry in the hash table is actually two consecutive strings,
261 both null-terminated; the first one is a mangled or linkage
262 name, and the second is the demangled name or just a zero byte
263 if the name doesn't demangle. */
264 struct htab *demangled_names_hash;
266 /* Vectors of all partial symbols read in from file. The actual data
267 is stored in the objfile_obstack. */
269 struct psymbol_allocation_list global_psymbols;
270 struct psymbol_allocation_list static_psymbols;
272 /* Each file contains a pointer to an array of minimal symbols for all
273 global symbols that are defined within the file. The array is
274 terminated by a "null symbol", one that has a NULL pointer for the
275 name and a zero value for the address. This makes it easy to walk
276 through the array when passed a pointer to somewhere in the middle
277 of it. There is also a count of the number of symbols, which does
278 not include the terminating null symbol. The array itself, as well
279 as all the data that it points to, should be allocated on the
280 objfile_obstack for this file. */
282 struct minimal_symbol *msymbols;
283 int minimal_symbol_count;
285 /* This is a hash table used to index the minimal symbols by name. */
287 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
289 /* This hash table is used to index the minimal symbols by their
292 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
294 /* Structure which keeps track of functions that manipulate objfile's
295 of the same type as this objfile. I.e. the function to read partial
296 symbols for example. Note that this structure is in statically
297 allocated memory, and is shared by all objfiles that use the
298 object module reader of this type. */
300 const struct sym_fns *sf;
302 /* The per-objfile information about the entry point, the scope (file/func)
303 containing the entry point, and the scope of the user's main() func. */
305 struct entry_info ei;
307 /* Information about stabs. Will be filled in with a dbx_symfile_info
308 struct by those readers that need it. */
309 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
310 data points implemented using "data" and "num_data" below. For
311 an example of how to use this replacement, see "objfile_data"
314 struct dbx_symfile_info *deprecated_sym_stab_info;
316 /* Hook for information for use by the symbol reader (currently used
317 for information shared by sym_init and sym_read). It is
318 typically a pointer to malloc'd memory. The symbol reader's finish
319 function is responsible for freeing the memory thusly allocated. */
320 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
321 data points implemented using "data" and "num_data" below. For
322 an example of how to use this replacement, see "objfile_data"
325 void *deprecated_sym_private;
327 /* Per objfile data-pointers required by other GDB modules. */
328 /* FIXME: kettenis/20030711: This mechanism could replace
329 deprecated_sym_stab_info and deprecated_sym_private
335 /* Set of relocation offsets to apply to each section.
336 Currently on the objfile_obstack (which makes no sense, but I'm
337 not sure it's harming anything).
339 These offsets indicate that all symbols (including partial and
340 minimal symbols) which have been read have been relocated by this
341 much. Symbols which are yet to be read need to be relocated by
344 struct section_offsets *section_offsets;
347 /* Indexes in the section_offsets array. These are initialized by the
348 *_symfile_offsets() family of functions (som_symfile_offsets,
349 xcoff_symfile_offsets, default_symfile_offsets). In theory they
350 should correspond to the section indexes used by bfd for the
351 current objfile. The exception to this for the time being is the
357 int sect_index_rodata;
359 /* These pointers are used to locate the section table, which
360 among other things, is used to map pc addresses into sections.
361 SECTIONS points to the first entry in the table, and
362 SECTIONS_END points to the first location past the last entry
363 in the table. Currently the table is stored on the
364 objfile_obstack (which makes no sense, but I'm not sure it's
365 harming anything). */
368 *sections, *sections_end;
370 /* GDB allows to have debug symbols in separate object files. This is
371 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
372 Although this is a tree structure, GDB only support one level
373 (ie a separate debug for a separate debug is not supported). Note that
374 separate debug object are in the main chain and therefore will be
375 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
376 has a non-nul separate_debug_objfile_backlink. */
378 /* Link to the first separate debug object, if any. */
379 struct objfile *separate_debug_objfile;
381 /* If this is a separate debug object, this is used as a link to the
382 actual executable objfile. */
383 struct objfile *separate_debug_objfile_backlink;
385 /* If this is a separate debug object, this is a link to the next one
386 for the same executable objfile. */
387 struct objfile *separate_debug_objfile_link;
389 /* Place to stash various statistics about this objfile. */
392 /* A symtab that the C++ code uses to stash special symbols
393 associated to namespaces. */
395 /* FIXME/carlton-2003-06-27: Delete this in a few years once
396 "possible namespace symbols" go away. */
397 struct symtab *cp_namespace_symtab;
399 /* A linked list of symbols created when reading template types or
400 function templates. These symbols are not stored in any symbol
401 table, so we have to keep them here to relocate them
403 struct symbol *template_symbols;
406 /* Defines for the objfile flag word. */
408 /* When an object file has its functions reordered (currently Irix-5.2
409 shared libraries exhibit this behaviour), we will need an expensive
410 algorithm to locate a partial symtab or symtab via an address.
411 To avoid this penalty for normal object files, we use this flag,
412 whose setting is determined upon symbol table read in. */
414 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
416 /* Distinguish between an objfile for a shared library and a "vanilla"
417 objfile. (If not set, the objfile may still actually be a solib.
418 This can happen if the user created the objfile by using the
419 add-symbol-file command. GDB doesn't in that situation actually
420 check whether the file is a solib. Rather, the target's
421 implementation of the solib interface is responsible for setting
422 this flag when noticing solibs used by an inferior.) */
424 #define OBJF_SHARED (1 << 1) /* From a shared library */
426 /* User requested that this objfile be read in it's entirety. */
428 #define OBJF_READNOW (1 << 2) /* Immediate full read */
430 /* This objfile was created because the user explicitly caused it
431 (e.g., used the add-symbol-file command). This bit offers a way
432 for run_command to remove old objfile entries which are no longer
433 valid (i.e., are associated with an old inferior), but to preserve
434 ones that the user explicitly loaded via the add-symbol-file
437 #define OBJF_USERLOADED (1 << 3) /* User loaded */
439 /* The object file that contains the runtime common minimal symbols
440 for SunOS4. Note that this objfile has no associated BFD. */
442 extern struct objfile *rt_common_objfile;
444 /* When we need to allocate a new type, we need to know which objfile_obstack
445 to allocate the type on, since there is one for each objfile. The places
446 where types are allocated are deeply buried in function call hierarchies
447 which know nothing about objfiles, so rather than trying to pass a
448 particular objfile down to them, we just do an end run around them and
449 set current_objfile to be whatever objfile we expect to be using at the
450 time types are being allocated. For instance, when we start reading
451 symbols for a particular objfile, we set current_objfile to point to that
452 objfile, and when we are done, we set it back to NULL, to ensure that we
453 never put a type someplace other than where we are expecting to put it.
454 FIXME: Maybe we should review the entire type handling system and
455 see if there is a better way to avoid this problem. */
457 extern struct objfile *current_objfile;
459 /* Declarations for functions defined in objfiles.c */
461 extern struct objfile *allocate_objfile (bfd *, int);
463 extern struct gdbarch *get_objfile_arch (struct objfile *);
465 extern void init_entry_point_info (struct objfile *);
467 extern int entry_point_address_query (CORE_ADDR *entry_p);
469 extern CORE_ADDR entry_point_address (void);
471 extern int build_objfile_section_table (struct objfile *);
473 extern void terminate_minimal_symbol_table (struct objfile *objfile);
475 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
476 const struct objfile *);
478 extern void put_objfile_before (struct objfile *, struct objfile *);
480 extern void objfile_to_front (struct objfile *);
482 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
484 extern void unlink_objfile (struct objfile *);
486 extern void free_objfile (struct objfile *);
488 extern void free_objfile_separate_debug (struct objfile *);
490 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
492 extern void free_all_objfiles (void);
494 extern void objfile_relocate (struct objfile *, struct section_offsets *);
496 extern int objfile_has_partial_symbols (struct objfile *objfile);
498 extern int objfile_has_full_symbols (struct objfile *objfile);
500 extern int objfile_has_symbols (struct objfile *objfile);
502 extern int have_partial_symbols (void);
504 extern int have_full_symbols (void);
506 extern void objfiles_changed (void);
508 /* This operation deletes all objfile entries that represent solibs that
509 weren't explicitly loaded by the user, via e.g., the add-symbol-file
512 extern void objfile_purge_solibs (void);
514 /* Functions for dealing with the minimal symbol table, really a misc
515 address<->symbol mapping for things we don't have debug symbols for. */
517 extern int have_minimal_symbols (void);
519 extern struct obj_section *find_pc_section (CORE_ADDR pc);
521 extern int in_plt_section (CORE_ADDR, char *);
523 /* Keep a registry of per-objfile data-pointers required by other GDB
526 /* Allocate an entry in the per-objfile registry. */
527 extern const struct objfile_data *register_objfile_data (void);
529 /* Allocate an entry in the per-objfile registry.
530 SAVE and FREE are called when clearing objfile data.
531 First all registered SAVE functions are called.
532 Then all registered FREE functions are called.
533 Either or both of SAVE, FREE may be NULL. */
534 extern const struct objfile_data *register_objfile_data_with_cleanup
535 (void (*save) (struct objfile *, void *),
536 void (*free) (struct objfile *, void *));
538 extern void clear_objfile_data (struct objfile *objfile);
539 extern void set_objfile_data (struct objfile *objfile,
540 const struct objfile_data *data, void *value);
541 extern void *objfile_data (struct objfile *objfile,
542 const struct objfile_data *data);
544 extern struct bfd *gdb_bfd_ref (struct bfd *abfd);
545 extern void gdb_bfd_unref (struct bfd *abfd);
546 extern int gdb_bfd_close_or_warn (struct bfd *abfd);
549 /* Traverse all object files in the current program space.
550 ALL_OBJFILES_SAFE works even if you delete the objfile during the
553 /* Traverse all object files in program space SS. */
555 #define ALL_PSPACE_OBJFILES(ss, obj) \
556 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
558 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
559 for ((obj) = ss->objfiles; \
560 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
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_SYMTABS(objfile, s) \
576 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
578 /* Traverse all minimal symbols in one objfile. */
580 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
581 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
583 /* Traverse all symtabs in all objfiles in the current symbol
586 #define ALL_SYMTABS(objfile, s) \
587 ALL_OBJFILES (objfile) \
588 ALL_OBJFILE_SYMTABS (objfile, s)
590 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
591 ALL_PSPACE_OBJFILES (ss, objfile) \
592 ALL_OBJFILE_SYMTABS (objfile, s)
594 /* Traverse all symtabs in all objfiles in the current program space,
595 skipping included files (which share a blockvector with their
598 #define ALL_PRIMARY_SYMTABS(objfile, s) \
599 ALL_OBJFILES (objfile) \
600 ALL_OBJFILE_SYMTABS (objfile, s) \
603 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
604 ALL_PSPACE_OBJFILES (ss, objfile) \
605 ALL_OBJFILE_SYMTABS (objfile, s) \
608 /* Traverse all minimal symbols in all objfiles in the current symbol
611 #define ALL_MSYMBOLS(objfile, m) \
612 ALL_OBJFILES (objfile) \
613 ALL_OBJFILE_MSYMBOLS (objfile, m)
615 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
616 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
618 /* Traverse all obj_sections in all objfiles in the current program
621 Note that this detects a "break" in the inner loop, and exits
622 immediately from the outer loop as well, thus, client code doesn't
623 need to know that this is implemented with a double for. The extra
624 hair is to make sure that a "break;" stops the outer loop iterating
625 as well, and both OBJFILE and OSECT are left unmodified:
627 - The outer loop learns about the inner loop's end condition, and
628 stops iterating if it detects the inner loop didn't reach its
629 end. In other words, the outer loop keeps going only if the
630 inner loop reached its end cleanly [(osect) ==
631 (objfile)->sections_end].
633 - OSECT is initialized in the outer loop initialization
634 expressions, such as if the inner loop has reached its end, so
635 the check mentioned above succeeds the first time.
637 - The trick to not clearing OBJFILE on a "break;" is, in the outer
638 loop's loop expression, advance OBJFILE, but iff the inner loop
639 reached its end. If not, there was a "break;", so leave OBJFILE
640 as is; the outer loop's conditional will break immediately as
641 well (as OSECT will be different from OBJFILE->sections_end). */
643 #define ALL_OBJSECTIONS(objfile, osect) \
644 for ((objfile) = current_program_space->objfiles, \
645 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
647 && (osect) == (objfile)->sections_end; \
648 ((osect) == (objfile)->sections_end \
649 ? ((objfile) = (objfile)->next, \
650 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
652 for ((osect) = (objfile)->sections; \
653 (osect) < (objfile)->sections_end; \
656 #define SECT_OFF_DATA(objfile) \
657 ((objfile->sect_index_data == -1) \
658 ? (internal_error (__FILE__, __LINE__, \
659 _("sect_index_data not initialized")), -1) \
660 : objfile->sect_index_data)
662 #define SECT_OFF_RODATA(objfile) \
663 ((objfile->sect_index_rodata == -1) \
664 ? (internal_error (__FILE__, __LINE__, \
665 _("sect_index_rodata not initialized")), -1) \
666 : objfile->sect_index_rodata)
668 #define SECT_OFF_TEXT(objfile) \
669 ((objfile->sect_index_text == -1) \
670 ? (internal_error (__FILE__, __LINE__, \
671 _("sect_index_text not initialized")), -1) \
672 : objfile->sect_index_text)
674 /* Sometimes the .bss section is missing from the objfile, so we don't
675 want to die here. Let the users of SECT_OFF_BSS deal with an
676 uninitialized section index. */
677 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
679 /* Answer whether there is more than one object file loaded. */
681 #define MULTI_OBJFILE_P() (object_files && object_files->next)
683 #endif /* !defined (OBJFILES_H) */