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 program space field "objfiles" (frequently referenced via
177 the macro "object_files") points to the first link in this
180 struct objfile *next;
182 /* The object file's name, tilde-expanded and absolute. Malloc'd; free it
183 if you free this struct. This pointer is never NULL. */
189 /* Some flag bits for this objfile.
190 The values are defined by OBJF_*. */
192 unsigned short flags;
194 /* The program space associated with this objfile. */
196 struct program_space *pspace;
198 /* Each objfile points to a linked list of symtabs derived from this file,
199 one symtab structure for each compilation unit (source file). Each link
200 in the symtab list contains a backpointer to this objfile. */
202 struct symtab *symtabs;
204 /* Each objfile points to a linked list of partial symtabs derived from
205 this file, one partial symtab structure for each compilation unit
208 struct partial_symtab *psymtabs;
210 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
211 have a map per the whole process but ADDRMAP cannot selectively remove
212 its items during FREE_OBJFILE. This mapping is already present even for
213 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
215 struct addrmap *psymtabs_addrmap;
217 /* List of freed partial symtabs, available for re-use. */
219 struct partial_symtab *free_psymtabs;
221 /* The object file's BFD. Can be null if the objfile contains only
222 minimal symbols, e.g. the run time common symbols for SunOS4. */
226 /* The gdbarch associated with the BFD. Note that this gdbarch is
227 determined solely from BFD information, without looking at target
228 information. The gdbarch determined from a running target may
229 differ from this e.g. with respect to register types and names. */
231 struct gdbarch *gdbarch;
233 /* The modification timestamp of the object file, as of the last time
234 we read its symbols. */
238 /* Cached 32-bit CRC as computed by gnu_debuglink_crc32. CRC32 is valid
243 /* Obstack to hold objects that should be freed when we load a new symbol
244 table from this object file. */
246 struct obstack objfile_obstack;
248 /* A byte cache where we can stash arbitrary "chunks" of bytes that
251 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
252 struct bcache *macro_cache; /* Byte cache for macros. */
253 struct bcache *filename_cache; /* Byte cache for file names. */
255 /* Hash table for mapping symbol names to demangled names. Each
256 entry in the hash table is actually two consecutive strings,
257 both null-terminated; the first one is a mangled or linkage
258 name, and the second is the demangled name or just a zero byte
259 if the name doesn't demangle. */
260 struct htab *demangled_names_hash;
262 /* Vectors of all partial symbols read in from file. The actual data
263 is stored in the objfile_obstack. */
265 struct psymbol_allocation_list global_psymbols;
266 struct psymbol_allocation_list static_psymbols;
268 /* Each file contains a pointer to an array of minimal symbols for all
269 global symbols that are defined within the file. The array is
270 terminated by a "null symbol", one that has a NULL pointer for the
271 name and a zero value for the address. This makes it easy to walk
272 through the array when passed a pointer to somewhere in the middle
273 of it. There is also a count of the number of symbols, which does
274 not include the terminating null symbol. The array itself, as well
275 as all the data that it points to, should be allocated on the
276 objfile_obstack for this file. */
278 struct minimal_symbol *msymbols;
279 int minimal_symbol_count;
281 /* This is a hash table used to index the minimal symbols by name. */
283 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
285 /* This hash table is used to index the minimal symbols by their
288 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
290 /* Structure which keeps track of functions that manipulate objfile's
291 of the same type as this objfile. I.e. the function to read partial
292 symbols for example. Note that this structure is in statically
293 allocated memory, and is shared by all objfiles that use the
294 object module reader of this type. */
296 const struct sym_fns *sf;
298 /* The per-objfile information about the entry point, the scope (file/func)
299 containing the entry point, and the scope of the user's main() func. */
301 struct entry_info ei;
303 /* Information about stabs. Will be filled in with a dbx_symfile_info
304 struct by those readers that need it. */
305 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
306 data points implemented using "data" and "num_data" below. For
307 an example of how to use this replacement, see "objfile_data"
310 struct dbx_symfile_info *deprecated_sym_stab_info;
312 /* Hook for information for use by the symbol reader (currently used
313 for information shared by sym_init and sym_read). It is
314 typically a pointer to malloc'd memory. The symbol reader's finish
315 function is responsible for freeing the memory thusly allocated. */
316 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
317 data points implemented using "data" and "num_data" below. For
318 an example of how to use this replacement, see "objfile_data"
321 void *deprecated_sym_private;
323 /* Per objfile data-pointers required by other GDB modules. */
324 /* FIXME: kettenis/20030711: This mechanism could replace
325 deprecated_sym_stab_info and deprecated_sym_private
331 /* Set of relocation offsets to apply to each section.
332 Currently on the objfile_obstack (which makes no sense, but I'm
333 not sure it's harming anything).
335 These offsets indicate that all symbols (including partial and
336 minimal symbols) which have been read have been relocated by this
337 much. Symbols which are yet to be read need to be relocated by
340 struct section_offsets *section_offsets;
343 /* Indexes in the section_offsets array. These are initialized by the
344 *_symfile_offsets() family of functions (som_symfile_offsets,
345 xcoff_symfile_offsets, default_symfile_offsets). In theory they
346 should correspond to the section indexes used by bfd for the
347 current objfile. The exception to this for the time being is the
353 int sect_index_rodata;
355 /* These pointers are used to locate the section table, which
356 among other things, is used to map pc addresses into sections.
357 SECTIONS points to the first entry in the table, and
358 SECTIONS_END points to the first location past the last entry
359 in the table. Currently the table is stored on the
360 objfile_obstack (which makes no sense, but I'm not sure it's
361 harming anything). */
364 *sections, *sections_end;
366 /* GDB allows to have debug symbols in separate object files. This is
367 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
368 Although this is a tree structure, GDB only support one level
369 (ie a separate debug for a separate debug is not supported). Note that
370 separate debug object are in the main chain and therefore will be
371 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
372 has a non-nul separate_debug_objfile_backlink. */
374 /* Link to the first separate debug object, if any. */
375 struct objfile *separate_debug_objfile;
377 /* If this is a separate debug object, this is used as a link to the
378 actual executable objfile. */
379 struct objfile *separate_debug_objfile_backlink;
381 /* If this is a separate debug object, this is a link to the next one
382 for the same executable objfile. */
383 struct objfile *separate_debug_objfile_link;
385 /* Place to stash various statistics about this objfile. */
388 /* A linked list of symbols created when reading template types or
389 function templates. These symbols are not stored in any symbol
390 table, so we have to keep them here to relocate them
392 struct symbol *template_symbols;
395 /* Defines for the objfile flag word. */
397 /* When an object file has its functions reordered (currently Irix-5.2
398 shared libraries exhibit this behaviour), we will need an expensive
399 algorithm to locate a partial symtab or symtab via an address.
400 To avoid this penalty for normal object files, we use this flag,
401 whose setting is determined upon symbol table read in. */
403 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
405 /* Distinguish between an objfile for a shared library and a "vanilla"
406 objfile. (If not set, the objfile may still actually be a solib.
407 This can happen if the user created the objfile by using the
408 add-symbol-file command. GDB doesn't in that situation actually
409 check whether the file is a solib. Rather, the target's
410 implementation of the solib interface is responsible for setting
411 this flag when noticing solibs used by an inferior.) */
413 #define OBJF_SHARED (1 << 1) /* From a shared library */
415 /* User requested that this objfile be read in it's entirety. */
417 #define OBJF_READNOW (1 << 2) /* Immediate full read */
419 /* This objfile was created because the user explicitly caused it
420 (e.g., used the add-symbol-file command). This bit offers a way
421 for run_command to remove old objfile entries which are no longer
422 valid (i.e., are associated with an old inferior), but to preserve
423 ones that the user explicitly loaded via the add-symbol-file
426 #define OBJF_USERLOADED (1 << 3) /* User loaded */
428 /* Set if we have tried to read partial symtabs for this objfile.
429 This is used to allow lazy reading of partial symtabs. */
431 #define OBJF_PSYMTABS_READ (1 << 4)
433 /* Set if this is the main symbol file
434 (as opposed to symbol file for dynamically loaded code). */
436 #define OBJF_MAINLINE (1 << 5)
438 /* The object file that contains the runtime common minimal symbols
439 for SunOS4. Note that this objfile has no associated BFD. */
441 extern struct objfile *rt_common_objfile;
443 /* Declarations for functions defined in objfiles.c */
445 extern struct objfile *allocate_objfile (bfd *, int);
447 extern struct gdbarch *get_objfile_arch (struct objfile *);
449 extern void init_entry_point_info (struct objfile *);
451 extern int entry_point_address_query (CORE_ADDR *entry_p);
453 extern CORE_ADDR entry_point_address (void);
455 extern int 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 objfile_to_front (struct objfile *);
466 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
468 extern void unlink_objfile (struct objfile *);
470 extern void free_objfile (struct objfile *);
472 extern void free_objfile_separate_debug (struct objfile *);
474 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
476 extern void free_all_objfiles (void);
478 extern void objfile_relocate (struct objfile *, struct section_offsets *);
480 extern int objfile_has_partial_symbols (struct objfile *objfile);
482 extern int objfile_has_full_symbols (struct objfile *objfile);
484 extern int objfile_has_symbols (struct objfile *objfile);
486 extern int have_partial_symbols (void);
488 extern int have_full_symbols (void);
490 extern void objfiles_changed (void);
492 /* This operation deletes all objfile entries that represent solibs that
493 weren't explicitly loaded by the user, via e.g., the add-symbol-file
496 extern void objfile_purge_solibs (void);
498 /* Functions for dealing with the minimal symbol table, really a misc
499 address<->symbol mapping for things we don't have debug symbols for. */
501 extern int have_minimal_symbols (void);
503 extern struct obj_section *find_pc_section (CORE_ADDR pc);
505 extern int in_plt_section (CORE_ADDR, char *);
507 /* Keep a registry of per-objfile data-pointers required by other GDB
510 /* Allocate an entry in the per-objfile registry. */
511 extern const struct objfile_data *register_objfile_data (void);
513 /* Allocate an entry in the per-objfile registry.
514 SAVE and FREE are called when clearing objfile data.
515 First all registered SAVE functions are called.
516 Then all registered FREE functions are called.
517 Either or both of SAVE, FREE may be NULL. */
518 extern const struct objfile_data *register_objfile_data_with_cleanup
519 (void (*save) (struct objfile *, void *),
520 void (*free) (struct objfile *, void *));
522 extern void clear_objfile_data (struct objfile *objfile);
523 extern void set_objfile_data (struct objfile *objfile,
524 const struct objfile_data *data, void *value);
525 extern void *objfile_data (struct objfile *objfile,
526 const struct objfile_data *data);
528 extern struct bfd *gdb_bfd_ref (struct bfd *abfd);
529 extern void gdb_bfd_unref (struct bfd *abfd);
530 extern int gdb_bfd_close_or_warn (struct bfd *abfd);
533 /* Traverse all object files in the current program space.
534 ALL_OBJFILES_SAFE works even if you delete the objfile during the
537 /* Traverse all object files in program space SS. */
539 #define ALL_PSPACE_OBJFILES(ss, obj) \
540 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
542 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
543 for ((obj) = ss->objfiles; \
544 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
547 #define ALL_OBJFILES(obj) \
548 for ((obj) = current_program_space->objfiles; \
552 #define ALL_OBJFILES_SAFE(obj,nxt) \
553 for ((obj) = current_program_space->objfiles; \
554 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
557 /* Traverse all symtabs in one objfile. */
559 #define ALL_OBJFILE_SYMTABS(objfile, s) \
560 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
562 /* Traverse all minimal symbols in one objfile. */
564 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
565 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
567 /* Traverse all symtabs in all objfiles in the current symbol
570 #define ALL_SYMTABS(objfile, s) \
571 ALL_OBJFILES (objfile) \
572 ALL_OBJFILE_SYMTABS (objfile, s)
574 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
575 ALL_PSPACE_OBJFILES (ss, objfile) \
576 ALL_OBJFILE_SYMTABS (objfile, s)
578 /* Traverse all symtabs in all objfiles in the current program space,
579 skipping included files (which share a blockvector with their
582 #define ALL_PRIMARY_SYMTABS(objfile, s) \
583 ALL_OBJFILES (objfile) \
584 ALL_OBJFILE_SYMTABS (objfile, s) \
587 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
588 ALL_PSPACE_OBJFILES (ss, objfile) \
589 ALL_OBJFILE_SYMTABS (objfile, s) \
592 /* Traverse all minimal symbols in all objfiles in the current symbol
595 #define ALL_MSYMBOLS(objfile, m) \
596 ALL_OBJFILES (objfile) \
597 ALL_OBJFILE_MSYMBOLS (objfile, m)
599 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
600 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
602 /* Traverse all obj_sections in all objfiles in the current program
605 Note that this detects a "break" in the inner loop, and exits
606 immediately from the outer loop as well, thus, client code doesn't
607 need to know that this is implemented with a double for. The extra
608 hair is to make sure that a "break;" stops the outer loop iterating
609 as well, and both OBJFILE and OSECT are left unmodified:
611 - The outer loop learns about the inner loop's end condition, and
612 stops iterating if it detects the inner loop didn't reach its
613 end. In other words, the outer loop keeps going only if the
614 inner loop reached its end cleanly [(osect) ==
615 (objfile)->sections_end].
617 - OSECT is initialized in the outer loop initialization
618 expressions, such as if the inner loop has reached its end, so
619 the check mentioned above succeeds the first time.
621 - The trick to not clearing OBJFILE on a "break;" is, in the outer
622 loop's loop expression, advance OBJFILE, but iff the inner loop
623 reached its end. If not, there was a "break;", so leave OBJFILE
624 as is; the outer loop's conditional will break immediately as
625 well (as OSECT will be different from OBJFILE->sections_end). */
627 #define ALL_OBJSECTIONS(objfile, osect) \
628 for ((objfile) = current_program_space->objfiles, \
629 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
631 && (osect) == (objfile)->sections_end; \
632 ((osect) == (objfile)->sections_end \
633 ? ((objfile) = (objfile)->next, \
634 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
636 for ((osect) = (objfile)->sections; \
637 (osect) < (objfile)->sections_end; \
640 #define SECT_OFF_DATA(objfile) \
641 ((objfile->sect_index_data == -1) \
642 ? (internal_error (__FILE__, __LINE__, \
643 _("sect_index_data not initialized")), -1) \
644 : objfile->sect_index_data)
646 #define SECT_OFF_RODATA(objfile) \
647 ((objfile->sect_index_rodata == -1) \
648 ? (internal_error (__FILE__, __LINE__, \
649 _("sect_index_rodata not initialized")), -1) \
650 : objfile->sect_index_rodata)
652 #define SECT_OFF_TEXT(objfile) \
653 ((objfile->sect_index_text == -1) \
654 ? (internal_error (__FILE__, __LINE__, \
655 _("sect_index_text not initialized")), -1) \
656 : objfile->sect_index_text)
658 /* Sometimes the .bss section is missing from the objfile, so we don't
659 want to die here. Let the users of SECT_OFF_BSS deal with an
660 uninitialized section index. */
661 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
663 /* Answer whether there is more than one object file loaded. */
665 #define MULTI_OBJFILE_P() (object_files && object_files->next)
667 #endif /* !defined (OBJFILES_H) */