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->obfd, 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->obfd, 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.
200 The values are defined by OBJF_*. */
202 unsigned short flags;
204 /* The program space associated with this objfile. */
206 struct program_space *pspace;
208 /* Each objfile points to a linked list of symtabs derived from this file,
209 one symtab structure for each compilation unit (source file). Each link
210 in the symtab list contains a backpointer to this objfile. */
212 struct symtab *symtabs;
214 /* Each objfile points to a linked list of partial symtabs derived from
215 this file, one partial symtab structure for each compilation unit
218 struct partial_symtab *psymtabs;
220 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
221 have a map per the whole process but ADDRMAP cannot selectively remove
222 its items during FREE_OBJFILE. This mapping is already present even for
223 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
225 struct addrmap *psymtabs_addrmap;
227 /* List of freed partial symtabs, available for re-use. */
229 struct partial_symtab *free_psymtabs;
231 /* The object file's BFD. Can be null if the objfile contains only
232 minimal symbols, e.g. the run time common symbols for SunOS4. */
236 /* The gdbarch associated with the BFD. Note that this gdbarch is
237 determined solely from BFD information, without looking at target
238 information. The gdbarch determined from a running target may
239 differ from this e.g. with respect to register types and names. */
241 struct gdbarch *gdbarch;
243 /* The modification timestamp of the object file, as of the last time
244 we read its symbols. */
248 /* Obstack to hold objects that should be freed when we load a new symbol
249 table from this object file. */
251 struct obstack objfile_obstack;
253 /* A byte cache where we can stash arbitrary "chunks" of bytes that
256 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
257 struct bcache *macro_cache; /* Byte cache for macros. */
258 struct bcache *filename_cache; /* Byte cache for file names. */
260 /* Hash table for mapping symbol names to demangled names. Each
261 entry in the hash table is actually two consecutive strings,
262 both null-terminated; the first one is a mangled or linkage
263 name, and the second is the demangled name or just a zero byte
264 if the name doesn't demangle. */
265 struct htab *demangled_names_hash;
267 /* Vectors of all partial symbols read in from file. The actual data
268 is stored in the objfile_obstack. */
270 struct psymbol_allocation_list global_psymbols;
271 struct psymbol_allocation_list static_psymbols;
273 /* Each file contains a pointer to an array of minimal symbols for all
274 global symbols that are defined within the file. The array is
275 terminated by a "null symbol", one that has a NULL pointer for the
276 name and a zero value for the address. This makes it easy to walk
277 through the array when passed a pointer to somewhere in the middle
278 of it. There is also a count of the number of symbols, which does
279 not include the terminating null symbol. The array itself, as well
280 as all the data that it points to, should be allocated on the
281 objfile_obstack for this file. */
283 struct minimal_symbol *msymbols;
284 int minimal_symbol_count;
286 /* This is a hash table used to index the minimal symbols by name. */
288 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
290 /* This hash table is used to index the minimal symbols by their
293 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
295 /* Structure which keeps track of functions that manipulate objfile's
296 of the same type as this objfile. I.e. the function to read partial
297 symbols for example. Note that this structure is in statically
298 allocated memory, and is shared by all objfiles that use the
299 object module reader of this type. */
301 const struct sym_fns *sf;
303 /* The per-objfile information about the entry point, the scope (file/func)
304 containing the entry point, and the scope of the user's main() func. */
306 struct entry_info ei;
308 /* Information about stabs. Will be filled in with a dbx_symfile_info
309 struct by those readers that need it. */
310 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
311 data points implemented using "data" and "num_data" below. For
312 an example of how to use this replacement, see "objfile_data"
315 struct dbx_symfile_info *deprecated_sym_stab_info;
317 /* Hook for information for use by the symbol reader (currently used
318 for information shared by sym_init and sym_read). It is
319 typically a pointer to malloc'd memory. The symbol reader's finish
320 function is responsible for freeing the memory thusly allocated. */
321 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
322 data points implemented using "data" and "num_data" below. For
323 an example of how to use this replacement, see "objfile_data"
326 void *deprecated_sym_private;
328 /* Per objfile data-pointers required by other GDB modules. */
329 /* FIXME: kettenis/20030711: This mechanism could replace
330 deprecated_sym_stab_info and deprecated_sym_private
336 /* Set of relocation offsets to apply to each section.
337 Currently on the objfile_obstack (which makes no sense, but I'm
338 not sure it's harming anything).
340 These offsets indicate that all symbols (including partial and
341 minimal symbols) which have been read have been relocated by this
342 much. Symbols which are yet to be read need to be relocated by
345 struct section_offsets *section_offsets;
348 /* Indexes in the section_offsets array. These are initialized by the
349 *_symfile_offsets() family of functions (som_symfile_offsets,
350 xcoff_symfile_offsets, default_symfile_offsets). In theory they
351 should correspond to the section indexes used by bfd for the
352 current objfile. The exception to this for the time being is the
358 int sect_index_rodata;
360 /* These pointers are used to locate the section table, which
361 among other things, is used to map pc addresses into sections.
362 SECTIONS points to the first entry in the table, and
363 SECTIONS_END points to the first location past the last entry
364 in the table. Currently the table is stored on the
365 objfile_obstack (which makes no sense, but I'm not sure it's
366 harming anything). */
369 *sections, *sections_end;
371 /* GDB allows to have debug symbols in separate object files. This is
372 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
373 Although this is a tree structure, GDB only support one level
374 (ie a separate debug for a separate debug is not supported). Note that
375 separate debug object are in the main chain and therefore will be
376 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
377 has a non-nul separate_debug_objfile_backlink. */
379 /* Link to the first separate debug object, if any. */
380 struct objfile *separate_debug_objfile;
382 /* If this is a separate debug object, this is used as a link to the
383 actual executable objfile. */
384 struct objfile *separate_debug_objfile_backlink;
386 /* If this is a separate debug object, this is a link to the next one
387 for the same executable objfile. */
388 struct objfile *separate_debug_objfile_link;
390 /* Place to stash various statistics about this objfile. */
393 /* A linked list of symbols created when reading template types or
394 function templates. These symbols are not stored in any symbol
395 table, so we have to keep them here to relocate them
397 struct symbol *template_symbols;
400 /* Defines for the objfile flag word. */
402 /* When an object file has its functions reordered (currently Irix-5.2
403 shared libraries exhibit this behaviour), we will need an expensive
404 algorithm to locate a partial symtab or symtab via an address.
405 To avoid this penalty for normal object files, we use this flag,
406 whose setting is determined upon symbol table read in. */
408 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
410 /* Distinguish between an objfile for a shared library and a "vanilla"
411 objfile. (If not set, the objfile may still actually be a solib.
412 This can happen if the user created the objfile by using the
413 add-symbol-file command. GDB doesn't in that situation actually
414 check whether the file is a solib. Rather, the target's
415 implementation of the solib interface is responsible for setting
416 this flag when noticing solibs used by an inferior.) */
418 #define OBJF_SHARED (1 << 1) /* From a shared library */
420 /* User requested that this objfile be read in it's entirety. */
422 #define OBJF_READNOW (1 << 2) /* Immediate full read */
424 /* This objfile was created because the user explicitly caused it
425 (e.g., used the add-symbol-file command). This bit offers a way
426 for run_command to remove old objfile entries which are no longer
427 valid (i.e., are associated with an old inferior), but to preserve
428 ones that the user explicitly loaded via the add-symbol-file
431 #define OBJF_USERLOADED (1 << 3) /* User loaded */
433 /* Set if we have tried to read partial symtabs for this objfile.
434 This is used to allow lazy reading of partial symtabs. */
436 #define OBJF_PSYMTABS_READ (1 << 4)
438 /* Set if this is the main symbol file
439 (as opposed to symbol file for dynamically loaded code). */
441 #define OBJF_MAINLINE (1 << 5)
443 /* The object file that contains the runtime common minimal symbols
444 for SunOS4. Note that this objfile has no associated BFD. */
446 extern struct objfile *rt_common_objfile;
448 /* Declarations for functions defined in objfiles.c */
450 extern struct objfile *allocate_objfile (bfd *, int);
452 extern struct gdbarch *get_objfile_arch (struct objfile *);
454 extern void init_entry_point_info (struct objfile *);
456 extern int entry_point_address_query (CORE_ADDR *entry_p);
458 extern CORE_ADDR entry_point_address (void);
460 extern int build_objfile_section_table (struct objfile *);
462 extern void terminate_minimal_symbol_table (struct objfile *objfile);
464 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
465 const struct objfile *);
467 extern void put_objfile_before (struct objfile *, struct objfile *);
469 extern void objfile_to_front (struct objfile *);
471 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
473 extern void unlink_objfile (struct objfile *);
475 extern void free_objfile (struct objfile *);
477 extern void free_objfile_separate_debug (struct objfile *);
479 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
481 extern void free_all_objfiles (void);
483 extern void objfile_relocate (struct objfile *, struct section_offsets *);
485 extern int objfile_has_partial_symbols (struct objfile *objfile);
487 extern int objfile_has_full_symbols (struct objfile *objfile);
489 extern int objfile_has_symbols (struct objfile *objfile);
491 extern int have_partial_symbols (void);
493 extern int have_full_symbols (void);
495 extern void objfiles_changed (void);
497 /* This operation deletes all objfile entries that represent solibs that
498 weren't explicitly loaded by the user, via e.g., the add-symbol-file
501 extern void objfile_purge_solibs (void);
503 /* Functions for dealing with the minimal symbol table, really a misc
504 address<->symbol mapping for things we don't have debug symbols for. */
506 extern int have_minimal_symbols (void);
508 extern struct obj_section *find_pc_section (CORE_ADDR pc);
510 extern int in_plt_section (CORE_ADDR, char *);
512 /* Keep a registry of per-objfile data-pointers required by other GDB
515 /* Allocate an entry in the per-objfile registry. */
516 extern const struct objfile_data *register_objfile_data (void);
518 /* Allocate an entry in the per-objfile registry.
519 SAVE and FREE are called when clearing objfile data.
520 First all registered SAVE functions are called.
521 Then all registered FREE functions are called.
522 Either or both of SAVE, FREE may be NULL. */
523 extern const struct objfile_data *register_objfile_data_with_cleanup
524 (void (*save) (struct objfile *, void *),
525 void (*free) (struct objfile *, void *));
527 extern void clear_objfile_data (struct objfile *objfile);
528 extern void set_objfile_data (struct objfile *objfile,
529 const struct objfile_data *data, void *value);
530 extern void *objfile_data (struct objfile *objfile,
531 const struct objfile_data *data);
533 extern struct bfd *gdb_bfd_ref (struct bfd *abfd);
534 extern void gdb_bfd_unref (struct bfd *abfd);
535 extern int gdb_bfd_close_or_warn (struct bfd *abfd);
538 /* Traverse all object files in the current program space.
539 ALL_OBJFILES_SAFE works even if you delete the objfile during the
542 /* Traverse all object files in program space SS. */
544 #define ALL_PSPACE_OBJFILES(ss, obj) \
545 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
547 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
548 for ((obj) = ss->objfiles; \
549 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
552 #define ALL_OBJFILES(obj) \
553 for ((obj) = current_program_space->objfiles; \
557 #define ALL_OBJFILES_SAFE(obj,nxt) \
558 for ((obj) = current_program_space->objfiles; \
559 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
562 /* Traverse all symtabs in one objfile. */
564 #define ALL_OBJFILE_SYMTABS(objfile, s) \
565 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
567 /* Traverse all minimal symbols in one objfile. */
569 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
570 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
572 /* Traverse all symtabs in all objfiles in the current symbol
575 #define ALL_SYMTABS(objfile, s) \
576 ALL_OBJFILES (objfile) \
577 ALL_OBJFILE_SYMTABS (objfile, s)
579 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
580 ALL_PSPACE_OBJFILES (ss, objfile) \
581 ALL_OBJFILE_SYMTABS (objfile, s)
583 /* Traverse all symtabs in all objfiles in the current program space,
584 skipping included files (which share a blockvector with their
587 #define ALL_PRIMARY_SYMTABS(objfile, s) \
588 ALL_OBJFILES (objfile) \
589 ALL_OBJFILE_SYMTABS (objfile, s) \
592 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
593 ALL_PSPACE_OBJFILES (ss, objfile) \
594 ALL_OBJFILE_SYMTABS (objfile, s) \
597 /* Traverse all minimal symbols in all objfiles in the current symbol
600 #define ALL_MSYMBOLS(objfile, m) \
601 ALL_OBJFILES (objfile) \
602 ALL_OBJFILE_MSYMBOLS (objfile, m)
604 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
605 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
607 /* Traverse all obj_sections in all objfiles in the current program
610 Note that this detects a "break" in the inner loop, and exits
611 immediately from the outer loop as well, thus, client code doesn't
612 need to know that this is implemented with a double for. The extra
613 hair is to make sure that a "break;" stops the outer loop iterating
614 as well, and both OBJFILE and OSECT are left unmodified:
616 - The outer loop learns about the inner loop's end condition, and
617 stops iterating if it detects the inner loop didn't reach its
618 end. In other words, the outer loop keeps going only if the
619 inner loop reached its end cleanly [(osect) ==
620 (objfile)->sections_end].
622 - OSECT is initialized in the outer loop initialization
623 expressions, such as if the inner loop has reached its end, so
624 the check mentioned above succeeds the first time.
626 - The trick to not clearing OBJFILE on a "break;" is, in the outer
627 loop's loop expression, advance OBJFILE, but iff the inner loop
628 reached its end. If not, there was a "break;", so leave OBJFILE
629 as is; the outer loop's conditional will break immediately as
630 well (as OSECT will be different from OBJFILE->sections_end). */
632 #define ALL_OBJSECTIONS(objfile, osect) \
633 for ((objfile) = current_program_space->objfiles, \
634 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
636 && (osect) == (objfile)->sections_end; \
637 ((osect) == (objfile)->sections_end \
638 ? ((objfile) = (objfile)->next, \
639 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
641 for ((osect) = (objfile)->sections; \
642 (osect) < (objfile)->sections_end; \
645 #define SECT_OFF_DATA(objfile) \
646 ((objfile->sect_index_data == -1) \
647 ? (internal_error (__FILE__, __LINE__, \
648 _("sect_index_data not initialized")), -1) \
649 : objfile->sect_index_data)
651 #define SECT_OFF_RODATA(objfile) \
652 ((objfile->sect_index_rodata == -1) \
653 ? (internal_error (__FILE__, __LINE__, \
654 _("sect_index_rodata not initialized")), -1) \
655 : objfile->sect_index_rodata)
657 #define SECT_OFF_TEXT(objfile) \
658 ((objfile->sect_index_text == -1) \
659 ? (internal_error (__FILE__, __LINE__, \
660 _("sect_index_text not initialized")), -1) \
661 : objfile->sect_index_text)
663 /* Sometimes the .bss section is missing from the objfile, so we don't
664 want to die here. Let the users of SECT_OFF_BSS deal with an
665 uninitialized section index. */
666 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
668 /* Answer whether there is more than one object file loaded. */
670 #define MULTI_OBJFILE_P() (object_files && object_files->next)
672 #endif /* !defined (OBJFILES_H) */