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 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #if !defined (OBJFILES_H)
24 #include "gdb_obstack.h" /* For obstack internals. */
25 #include "symfile.h" /* For struct psymbol_allocation_list */
26 #include "progspace.h"
33 /* This structure maintains information on a per-objfile basis about the
34 "entry point" of the objfile, and the scope within which the entry point
35 exists. It is possible that gdb will see more than one objfile that is
36 executable, each with its own entry point.
38 For example, for dynamically linked executables in SVR4, the dynamic linker
39 code is contained within the shared C library, which is actually executable
40 and is run by the kernel first when an exec is done of a user executable
41 that is dynamically linked. The dynamic linker within the shared C library
42 then maps in the various program segments in the user executable and jumps
43 to the user executable's recorded entry point, as if the call had been made
44 directly by the kernel.
46 The traditional gdb method of using this info was to use the
47 recorded entry point to set the entry-file's lowpc and highpc from
48 the debugging information, where these values are the starting
49 address (inclusive) and ending address (exclusive) of the
50 instruction space in the executable which correspond to the
51 "startup file", I.E. crt0.o in most cases. This file is assumed to
52 be a startup file and frames with pc's inside it are treated as
53 nonexistent. Setting these variables is necessary so that
54 backtraces do not fly off the bottom of the stack.
56 NOTE: cagney/2003-09-09: It turns out that this "traditional"
57 method doesn't work. Corinna writes: ``It turns out that the call
58 to test for "inside entry file" destroys a meaningful backtrace
59 under some conditions. E. g. the backtrace tests in the asm-source
60 testcase are broken for some targets. In this test the functions
61 are all implemented as part of one file and the testcase is not
62 necessarily linked with a start file (depending on the target).
63 What happens is, that the first frame is printed normaly and
64 following frames are treated as being inside the enttry file then.
65 This way, only the #0 frame is printed in the backtrace output.''
66 Ref "frame.c" "NOTE: vinschen/2003-04-01".
68 Gdb also supports an alternate method to avoid running off the bottom
71 There are two frames that are "special", the frame for the function
72 containing the process entry point, since it has no predecessor frame,
73 and the frame for the function containing the user code entry point
74 (the main() function), since all the predecessor frames are for the
75 process startup code. Since we have no guarantee that the linked
76 in startup modules have any debugging information that gdb can use,
77 we need to avoid following frame pointers back into frames that might
78 have been built in the startup code, as we might get hopelessly
79 confused. However, we almost always have debugging information
82 These variables are used to save the range of PC values which are
83 valid within the main() function and within the function containing
84 the process entry point. If we always consider the frame for
85 main() as the outermost frame when debugging user code, and the
86 frame for the process entry point function as the outermost frame
87 when debugging startup code, then all we have to do is have
88 DEPRECATED_FRAME_CHAIN_VALID return false whenever a frame's
89 current PC is within the range specified by these variables. In
90 essence, we set "ceilings" in the frame chain beyond which we will
91 not proceed when following the frame chain back up the stack.
93 A nice side effect is that we can still debug startup code without
94 running off the end of the frame chain, assuming that we have usable
95 debugging information in the startup modules, and if we choose to not
96 use the block at main, or can't find it for some reason, everything
97 still works as before. And if we have no startup code debugging
98 information but we do have usable information for main(), backtraces
99 from user code don't go wandering off into the startup code. */
103 /* The relocated value we should use for this objfile entry point. */
104 CORE_ADDR entry_point;
106 /* Set to 1 iff ENTRY_POINT contains a valid value. */
107 unsigned entry_point_p : 1;
110 /* Sections in an objfile. The section offsets are stored in the
115 struct bfd_section *the_bfd_section; /* BFD section pointer */
117 /* Objfile this section is part of. */
118 struct objfile *objfile;
120 /* True if this "overlay section" is mapped into an "overlay region". */
124 /* Relocation offset applied to S. */
125 #define obj_section_offset(s) \
126 (((s)->objfile->section_offsets)->offsets[(s)->the_bfd_section->index])
128 /* The memory address of section S (vma + offset). */
129 #define obj_section_addr(s) \
130 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \
131 + obj_section_offset (s))
133 /* The one-passed-the-end memory address of section S
134 (vma + size + offset). */
135 #define obj_section_endaddr(s) \
136 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \
137 + bfd_get_section_size ((s)->the_bfd_section) \
138 + obj_section_offset (s))
140 /* The "objstats" structure provides a place for gdb to record some
141 interesting information about its internal state at runtime, on a
142 per objfile basis, such as information about the number of symbols
143 read, size of string table (if any), etc. */
147 int n_minsyms; /* Number of minimal symbols read */
148 int n_psyms; /* Number of partial symbols read */
149 int n_syms; /* Number of full symbols read */
150 int n_stabs; /* Number of ".stabs" read (if applicable) */
151 int n_types; /* Number of types */
152 int sz_strtab; /* Size of stringtable, (if applicable) */
155 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
156 #define OBJSTATS struct objstats stats
157 extern void print_objfile_statistics (void);
158 extern void print_symbol_bcache_statistics (void);
160 /* Number of entries in the minimal symbol hash table. */
161 #define MINIMAL_SYMBOL_HASH_SIZE 2039
163 /* Master structure for keeping track of each file from which
164 gdb reads symbols. There are several ways these get allocated: 1.
165 The main symbol file, symfile_objfile, set by the symbol-file command,
166 2. Additional symbol files added by the add-symbol-file command,
167 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
168 for modules that were loaded when GDB attached to a remote system
169 (see remote-vx.c). */
174 /* All struct objfile's are chained together by their next pointers.
175 The global variable "object_files" points to the first link in this
178 FIXME: There is a problem here if the objfile is reusable, and if
179 multiple users are to be supported. The problem is that the objfile
180 list is linked through a member of the objfile struct itself, which
181 is only valid for one gdb process. The list implementation needs to
182 be changed to something like:
184 struct list {struct list *next; struct objfile *objfile};
186 where the list structure is completely maintained separately within
189 struct objfile *next;
191 /* The object file's name, tilde-expanded and absolute.
192 Malloc'd; free it if you free this struct. */
196 /* Some flag bits for this objfile. */
198 unsigned short flags;
200 /* The program space associated with this objfile. */
202 struct program_space *pspace;
204 /* Each objfile points to a linked list of symtabs derived from this file,
205 one symtab structure for each compilation unit (source file). Each link
206 in the symtab list contains a backpointer to this objfile. */
208 struct symtab *symtabs;
210 /* Each objfile points to a linked list of partial symtabs derived from
211 this file, one partial symtab structure for each compilation unit
214 struct partial_symtab *psymtabs;
216 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
217 have a map per the whole process but ADDRMAP cannot selectively remove
218 its items during FREE_OBJFILE. This mapping is already present even for
219 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
221 struct addrmap *psymtabs_addrmap;
223 /* List of freed partial symtabs, available for re-use */
225 struct partial_symtab *free_psymtabs;
227 /* The object file's BFD. Can be null if the objfile contains only
228 minimal symbols, e.g. the run time common symbols for SunOS4. */
232 /* The gdbarch associated with the BFD. Note that this gdbarch is
233 determined solely from BFD information, without looking at target
234 information. The gdbarch determined from a running target may
235 differ from this e.g. with respect to register types and names. */
237 struct gdbarch *gdbarch;
239 /* The modification timestamp of the object file, as of the last time
240 we read its symbols. */
244 /* Obstack to hold objects that should be freed when we load a new symbol
245 table from this object file. */
247 struct obstack objfile_obstack;
249 /* A byte cache where we can stash arbitrary "chunks" of bytes that
252 struct bcache *psymbol_cache; /* Byte cache for partial syms */
253 struct bcache *macro_cache; /* Byte cache for macros */
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 terminated
270 by a "null symbol", one that has a NULL pointer for the name and a zero
271 value for the address. This makes it easy to walk through the array
272 when passed a pointer to somewhere in the middle of it. There is also
273 a count of the number of symbols, which does not include the terminating
274 null symbol. The array itself, as well as all the data that it points
275 to, should be allocated on the objfile_obstack for this file. */
277 struct minimal_symbol *msymbols;
278 int minimal_symbol_count;
280 /* This is a hash table used to index the minimal symbols by name. */
282 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
284 /* This hash table is used to index the minimal symbols by their
287 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
289 /* Structure which keeps track of functions that manipulate objfile's
290 of the same type as this objfile. I.E. the function to read partial
291 symbols for example. Note that this structure is in statically
292 allocated memory, and is shared by all objfiles that use the
293 object module reader of this type. */
297 /* The per-objfile information about the entry point, the scope (file/func)
298 containing the entry point, and the scope of the user's main() func. */
300 struct entry_info ei;
302 /* Information about stabs. Will be filled in with a dbx_symfile_info
303 struct by those readers that need it. */
304 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
305 data points implemented using "data" and "num_data" below. For
306 an example of how to use this replacement, see "objfile_data"
309 struct dbx_symfile_info *deprecated_sym_stab_info;
311 /* Hook for information for use by the symbol reader (currently used
312 for information shared by sym_init and sym_read). It is
313 typically a pointer to malloc'd memory. The symbol reader's finish
314 function is responsible for freeing the memory thusly allocated. */
315 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
316 data points implemented using "data" and "num_data" below. For
317 an example of how to use this replacement, see "objfile_data"
320 void *deprecated_sym_private;
322 /* Per objfile data-pointers required by other GDB modules. */
323 /* FIXME: kettenis/20030711: This mechanism could replace
324 deprecated_sym_stab_info and deprecated_sym_private
330 /* Set of relocation offsets to apply to each section.
331 Currently on the objfile_obstack (which makes no sense, but I'm
332 not sure it's harming anything).
334 These offsets indicate that all symbols (including partial and
335 minimal symbols) which have been read have been relocated by this
336 much. Symbols which are yet to be read need to be relocated by
339 struct section_offsets *section_offsets;
342 /* Indexes in the section_offsets array. These are initialized by the
343 *_symfile_offsets() family of functions (som_symfile_offsets,
344 xcoff_symfile_offsets, default_symfile_offsets). In theory they
345 should correspond to the section indexes used by bfd for the
346 current objfile. The exception to this for the time being is the
352 int sect_index_rodata;
354 /* These pointers are used to locate the section table, which
355 among other things, is used to map pc addresses into sections.
356 SECTIONS points to the first entry in the table, and
357 SECTIONS_END points to the first location past the last entry
358 in the table. Currently the table is stored on the
359 objfile_obstack (which makes no sense, but I'm not sure it's
360 harming anything). */
363 *sections, *sections_end;
365 /* Link to objfile that contains the debug symbols for this one.
366 One is loaded if this file has an debug link to an existing
367 debug file with the right checksum */
368 struct objfile *separate_debug_objfile;
370 /* If this is a separate debug object, this is used as a link to the
371 actual executable objfile. */
372 struct objfile *separate_debug_objfile_backlink;
374 /* Place to stash various statistics about this objfile */
377 /* A symtab that the C++ code uses to stash special symbols
378 associated to namespaces. */
380 /* FIXME/carlton-2003-06-27: Delete this in a few years once
381 "possible namespace symbols" go away. */
382 struct symtab *cp_namespace_symtab;
385 /* Defines for the objfile flag word. */
387 /* When an object file has its functions reordered (currently Irix-5.2
388 shared libraries exhibit this behaviour), we will need an expensive
389 algorithm to locate a partial symtab or symtab via an address.
390 To avoid this penalty for normal object files, we use this flag,
391 whose setting is determined upon symbol table read in. */
393 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
395 /* Distinguish between an objfile for a shared library and a "vanilla"
396 objfile. (If not set, the objfile may still actually be a solib.
397 This can happen if the user created the objfile by using the
398 add-symbol-file command. GDB doesn't in that situation actually
399 check whether the file is a solib. Rather, the target's
400 implementation of the solib interface is responsible for setting
401 this flag when noticing solibs used by an inferior.) */
403 #define OBJF_SHARED (1 << 1) /* From a shared library */
405 /* User requested that this objfile be read in it's entirety. */
407 #define OBJF_READNOW (1 << 2) /* Immediate full read */
409 /* This objfile was created because the user explicitly caused it
410 (e.g., used the add-symbol-file command). This bit offers a way
411 for run_command to remove old objfile entries which are no longer
412 valid (i.e., are associated with an old inferior), but to preserve
413 ones that the user explicitly loaded via the add-symbol-file
416 #define OBJF_USERLOADED (1 << 3) /* User loaded */
418 /* The object file that contains the runtime common minimal symbols
419 for SunOS4. Note that this objfile has no associated BFD. */
421 extern struct objfile *rt_common_objfile;
423 /* When we need to allocate a new type, we need to know which objfile_obstack
424 to allocate the type on, since there is one for each objfile. The places
425 where types are allocated are deeply buried in function call hierarchies
426 which know nothing about objfiles, so rather than trying to pass a
427 particular objfile down to them, we just do an end run around them and
428 set current_objfile to be whatever objfile we expect to be using at the
429 time types are being allocated. For instance, when we start reading
430 symbols for a particular objfile, we set current_objfile to point to that
431 objfile, and when we are done, we set it back to NULL, to ensure that we
432 never put a type someplace other than where we are expecting to put it.
433 FIXME: Maybe we should review the entire type handling system and
434 see if there is a better way to avoid this problem. */
436 extern struct objfile *current_objfile;
438 /* Declarations for functions defined in objfiles.c */
440 extern struct objfile *allocate_objfile (bfd *, int);
442 extern struct gdbarch *get_objfile_arch (struct objfile *);
444 extern void init_entry_point_info (struct objfile *);
446 extern int entry_point_address_query (CORE_ADDR *entry_p);
448 extern CORE_ADDR entry_point_address (void);
450 extern int build_objfile_section_table (struct objfile *);
452 extern void terminate_minimal_symbol_table (struct objfile *objfile);
454 extern void put_objfile_before (struct objfile *, struct objfile *);
456 extern void objfile_to_front (struct objfile *);
458 extern void unlink_objfile (struct objfile *);
460 extern void free_objfile (struct objfile *);
462 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
464 extern void free_all_objfiles (void);
466 extern void objfile_relocate (struct objfile *, struct section_offsets *);
468 extern int objfile_has_partial_symbols (struct objfile *objfile);
470 extern int objfile_has_full_symbols (struct objfile *objfile);
472 extern int objfile_has_symbols (struct objfile *objfile);
474 extern int have_partial_symbols (void);
476 extern int have_full_symbols (void);
478 extern void objfiles_changed (void);
480 /* This operation deletes all objfile entries that represent solibs that
481 weren't explicitly loaded by the user, via e.g., the add-symbol-file
484 extern void objfile_purge_solibs (void);
486 /* Functions for dealing with the minimal symbol table, really a misc
487 address<->symbol mapping for things we don't have debug symbols for. */
489 extern int have_minimal_symbols (void);
491 extern struct obj_section *find_pc_section (CORE_ADDR pc);
493 extern int in_plt_section (CORE_ADDR, char *);
495 /* Keep a registry of per-objfile data-pointers required by other GDB
498 /* Allocate an entry in the per-objfile registry. */
499 extern const struct objfile_data *register_objfile_data (void);
501 /* Allocate an entry in the per-objfile registry.
502 SAVE and FREE are called when clearing objfile data.
503 First all registered SAVE functions are called.
504 Then all registered FREE functions are called.
505 Either or both of SAVE, FREE may be NULL. */
506 extern const struct objfile_data *register_objfile_data_with_cleanup
507 (void (*save) (struct objfile *, void *),
508 void (*free) (struct objfile *, void *));
510 extern void clear_objfile_data (struct objfile *objfile);
511 extern void set_objfile_data (struct objfile *objfile,
512 const struct objfile_data *data, void *value);
513 extern void *objfile_data (struct objfile *objfile,
514 const struct objfile_data *data);
516 extern struct bfd *gdb_bfd_ref (struct bfd *abfd);
517 extern void gdb_bfd_unref (struct bfd *abfd);
520 /* Traverse all object files in the current program space.
521 ALL_OBJFILES_SAFE works even if you delete the objfile during the
524 /* Traverse all object files in program space SS. */
526 #define ALL_PSPACE_OBJFILES(ss, obj) \
527 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
529 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
530 for ((obj) = ss->objfiles; \
531 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
534 #define ALL_OBJFILES(obj) \
535 for ((obj) = current_program_space->objfiles; \
539 #define ALL_OBJFILES_SAFE(obj,nxt) \
540 for ((obj) = current_program_space->objfiles; \
541 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
544 /* Traverse all symtabs in one objfile. */
546 #define ALL_OBJFILE_SYMTABS(objfile, s) \
547 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
549 /* Traverse all psymtabs in one objfile. */
551 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
552 for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
554 /* Traverse all minimal symbols in one objfile. */
556 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
557 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
559 /* Traverse all symtabs in all objfiles in the current symbol
562 #define ALL_SYMTABS(objfile, s) \
563 ALL_OBJFILES (objfile) \
564 ALL_OBJFILE_SYMTABS (objfile, s)
566 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
567 ALL_PSPACE_OBJFILES (ss, objfile) \
568 ALL_OBJFILE_SYMTABS (objfile, s)
570 /* Traverse all symtabs in all objfiles in the current program space,
571 skipping included files (which share a blockvector with their
574 #define ALL_PRIMARY_SYMTABS(objfile, s) \
575 ALL_OBJFILES (objfile) \
576 ALL_OBJFILE_SYMTABS (objfile, s) \
579 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
580 ALL_PSPACE_OBJFILES (ss, objfile) \
581 ALL_OBJFILE_SYMTABS (objfile, s) \
584 /* Traverse all psymtabs in all objfiles in the current symbol
587 #define ALL_PSYMTABS(objfile, p) \
588 ALL_OBJFILES (objfile) \
589 ALL_OBJFILE_PSYMTABS (objfile, p)
591 #define ALL_PSPACE_PSYMTABS(ss, objfile, p) \
592 ALL_PSPACE_OBJFILES (ss, objfile) \
593 ALL_OBJFILE_PSYMTABS (objfile, p)
595 /* Traverse all minimal symbols in all objfiles in the current symbol
598 #define ALL_MSYMBOLS(objfile, m) \
599 ALL_OBJFILES (objfile) \
600 ALL_OBJFILE_MSYMBOLS (objfile, m)
602 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
603 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
605 #define ALL_OBJSECTIONS(objfile, osect) \
606 ALL_OBJFILES (objfile) \
607 ALL_OBJFILE_OSECTIONS (objfile, osect)
609 #define SECT_OFF_DATA(objfile) \
610 ((objfile->sect_index_data == -1) \
611 ? (internal_error (__FILE__, __LINE__, _("sect_index_data not initialized")), -1) \
612 : objfile->sect_index_data)
614 #define SECT_OFF_RODATA(objfile) \
615 ((objfile->sect_index_rodata == -1) \
616 ? (internal_error (__FILE__, __LINE__, _("sect_index_rodata not initialized")), -1) \
617 : objfile->sect_index_rodata)
619 #define SECT_OFF_TEXT(objfile) \
620 ((objfile->sect_index_text == -1) \
621 ? (internal_error (__FILE__, __LINE__, _("sect_index_text not initialized")), -1) \
622 : objfile->sect_index_text)
624 /* Sometimes the .bss section is missing from the objfile, so we don't
625 want to die here. Let the users of SECT_OFF_BSS deal with an
626 uninitialized section index. */
627 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
629 /* Answer whether there is more than one object file loaded. */
631 #define MULTI_OBJFILE_P() (object_files && object_files->next)
633 #endif /* !defined (OBJFILES_H) */