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 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 */
254 struct bcache *filename_cache; /* Byte cache for file names. */
256 /* Hash table for mapping symbol names to demangled names. Each
257 entry in the hash table is actually two consecutive strings,
258 both null-terminated; the first one is a mangled or linkage
259 name, and the second is the demangled name or just a zero byte
260 if the name doesn't demangle. */
261 struct htab *demangled_names_hash;
263 /* Vectors of all partial symbols read in from file. The actual data
264 is stored in the objfile_obstack. */
266 struct psymbol_allocation_list global_psymbols;
267 struct psymbol_allocation_list static_psymbols;
269 /* Each file contains a pointer to an array of minimal symbols for all
270 global symbols that are defined within the file. The array is terminated
271 by a "null symbol", one that has a NULL pointer for the name and a zero
272 value for the address. This makes it easy to walk through the array
273 when passed a pointer to somewhere in the middle of it. There is also
274 a count of the number of symbols, which does not include the terminating
275 null symbol. The array itself, as well as all the data that it points
276 to, should be allocated on the 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. */
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 /* Link to objfile that contains the debug symbols for this one.
367 One is loaded if this file has an debug link to an existing
368 debug file with the right checksum */
369 struct objfile *separate_debug_objfile;
371 /* If this is a separate debug object, this is used as a link to the
372 actual executable objfile. */
373 struct objfile *separate_debug_objfile_backlink;
375 /* Place to stash various statistics about this objfile */
378 /* A symtab that the C++ code uses to stash special symbols
379 associated to namespaces. */
381 /* FIXME/carlton-2003-06-27: Delete this in a few years once
382 "possible namespace symbols" go away. */
383 struct symtab *cp_namespace_symtab;
386 /* Defines for the objfile flag word. */
388 /* When an object file has its functions reordered (currently Irix-5.2
389 shared libraries exhibit this behaviour), we will need an expensive
390 algorithm to locate a partial symtab or symtab via an address.
391 To avoid this penalty for normal object files, we use this flag,
392 whose setting is determined upon symbol table read in. */
394 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
396 /* Distinguish between an objfile for a shared library and a "vanilla"
397 objfile. (If not set, the objfile may still actually be a solib.
398 This can happen if the user created the objfile by using the
399 add-symbol-file command. GDB doesn't in that situation actually
400 check whether the file is a solib. Rather, the target's
401 implementation of the solib interface is responsible for setting
402 this flag when noticing solibs used by an inferior.) */
404 #define OBJF_SHARED (1 << 1) /* From a shared library */
406 /* User requested that this objfile be read in it's entirety. */
408 #define OBJF_READNOW (1 << 2) /* Immediate full read */
410 /* This objfile was created because the user explicitly caused it
411 (e.g., used the add-symbol-file command). This bit offers a way
412 for run_command to remove old objfile entries which are no longer
413 valid (i.e., are associated with an old inferior), but to preserve
414 ones that the user explicitly loaded via the add-symbol-file
417 #define OBJF_USERLOADED (1 << 3) /* User loaded */
419 /* The object file that contains the runtime common minimal symbols
420 for SunOS4. Note that this objfile has no associated BFD. */
422 extern struct objfile *rt_common_objfile;
424 /* When we need to allocate a new type, we need to know which objfile_obstack
425 to allocate the type on, since there is one for each objfile. The places
426 where types are allocated are deeply buried in function call hierarchies
427 which know nothing about objfiles, so rather than trying to pass a
428 particular objfile down to them, we just do an end run around them and
429 set current_objfile to be whatever objfile we expect to be using at the
430 time types are being allocated. For instance, when we start reading
431 symbols for a particular objfile, we set current_objfile to point to that
432 objfile, and when we are done, we set it back to NULL, to ensure that we
433 never put a type someplace other than where we are expecting to put it.
434 FIXME: Maybe we should review the entire type handling system and
435 see if there is a better way to avoid this problem. */
437 extern struct objfile *current_objfile;
439 /* Declarations for functions defined in objfiles.c */
441 extern struct objfile *allocate_objfile (bfd *, int);
443 extern struct gdbarch *get_objfile_arch (struct objfile *);
445 extern void init_entry_point_info (struct objfile *);
447 extern int entry_point_address_query (CORE_ADDR *entry_p);
449 extern CORE_ADDR entry_point_address (void);
451 extern int build_objfile_section_table (struct objfile *);
453 extern void terminate_minimal_symbol_table (struct objfile *objfile);
455 extern void put_objfile_before (struct objfile *, struct objfile *);
457 extern void objfile_to_front (struct objfile *);
459 extern void unlink_objfile (struct objfile *);
461 extern void free_objfile (struct objfile *);
463 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
465 extern void free_all_objfiles (void);
467 extern void objfile_relocate (struct objfile *, struct section_offsets *);
469 extern int objfile_has_partial_symbols (struct objfile *objfile);
471 extern int objfile_has_full_symbols (struct objfile *objfile);
473 extern int objfile_has_symbols (struct objfile *objfile);
475 extern int have_partial_symbols (void);
477 extern int have_full_symbols (void);
479 extern void objfiles_changed (void);
481 /* This operation deletes all objfile entries that represent solibs that
482 weren't explicitly loaded by the user, via e.g., the add-symbol-file
485 extern void objfile_purge_solibs (void);
487 /* Functions for dealing with the minimal symbol table, really a misc
488 address<->symbol mapping for things we don't have debug symbols for. */
490 extern int have_minimal_symbols (void);
492 extern struct obj_section *find_pc_section (CORE_ADDR pc);
494 extern int in_plt_section (CORE_ADDR, char *);
496 /* Keep a registry of per-objfile data-pointers required by other GDB
499 /* Allocate an entry in the per-objfile registry. */
500 extern const struct objfile_data *register_objfile_data (void);
502 /* Allocate an entry in the per-objfile registry.
503 SAVE and FREE are called when clearing objfile data.
504 First all registered SAVE functions are called.
505 Then all registered FREE functions are called.
506 Either or both of SAVE, FREE may be NULL. */
507 extern const struct objfile_data *register_objfile_data_with_cleanup
508 (void (*save) (struct objfile *, void *),
509 void (*free) (struct objfile *, void *));
511 extern void clear_objfile_data (struct objfile *objfile);
512 extern void set_objfile_data (struct objfile *objfile,
513 const struct objfile_data *data, void *value);
514 extern void *objfile_data (struct objfile *objfile,
515 const struct objfile_data *data);
517 extern struct bfd *gdb_bfd_ref (struct bfd *abfd);
518 extern void gdb_bfd_unref (struct bfd *abfd);
521 /* Traverse all object files in the current program space.
522 ALL_OBJFILES_SAFE works even if you delete the objfile during the
525 /* Traverse all object files in program space SS. */
527 #define ALL_PSPACE_OBJFILES(ss, obj) \
528 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
530 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
531 for ((obj) = ss->objfiles; \
532 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
535 #define ALL_OBJFILES(obj) \
536 for ((obj) = current_program_space->objfiles; \
540 #define ALL_OBJFILES_SAFE(obj,nxt) \
541 for ((obj) = current_program_space->objfiles; \
542 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
545 /* Traverse all symtabs in one objfile. */
547 #define ALL_OBJFILE_SYMTABS(objfile, s) \
548 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
550 /* Traverse all psymtabs in one objfile. */
552 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
553 for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
555 /* Traverse all minimal symbols in one objfile. */
557 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
558 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
560 /* Traverse all symtabs in all objfiles in the current symbol
563 #define ALL_SYMTABS(objfile, s) \
564 ALL_OBJFILES (objfile) \
565 ALL_OBJFILE_SYMTABS (objfile, s)
567 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
568 ALL_PSPACE_OBJFILES (ss, objfile) \
569 ALL_OBJFILE_SYMTABS (objfile, s)
571 /* Traverse all symtabs in all objfiles in the current program space,
572 skipping included files (which share a blockvector with their
575 #define ALL_PRIMARY_SYMTABS(objfile, s) \
576 ALL_OBJFILES (objfile) \
577 ALL_OBJFILE_SYMTABS (objfile, s) \
580 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
581 ALL_PSPACE_OBJFILES (ss, objfile) \
582 ALL_OBJFILE_SYMTABS (objfile, s) \
585 /* Traverse all psymtabs in all objfiles in the current symbol
588 #define ALL_PSYMTABS(objfile, p) \
589 ALL_OBJFILES (objfile) \
590 ALL_OBJFILE_PSYMTABS (objfile, p)
592 #define ALL_PSPACE_PSYMTABS(ss, objfile, p) \
593 ALL_PSPACE_OBJFILES (ss, objfile) \
594 ALL_OBJFILE_PSYMTABS (objfile, p)
596 /* Traverse all minimal symbols in all objfiles in the current symbol
599 #define ALL_MSYMBOLS(objfile, m) \
600 ALL_OBJFILES (objfile) \
601 ALL_OBJFILE_MSYMBOLS (objfile, m)
603 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
604 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
606 #define ALL_OBJSECTIONS(objfile, osect) \
607 ALL_OBJFILES (objfile) \
608 ALL_OBJFILE_OSECTIONS (objfile, osect)
610 #define SECT_OFF_DATA(objfile) \
611 ((objfile->sect_index_data == -1) \
612 ? (internal_error (__FILE__, __LINE__, _("sect_index_data not initialized")), -1) \
613 : objfile->sect_index_data)
615 #define SECT_OFF_RODATA(objfile) \
616 ((objfile->sect_index_rodata == -1) \
617 ? (internal_error (__FILE__, __LINE__, _("sect_index_rodata not initialized")), -1) \
618 : objfile->sect_index_rodata)
620 #define SECT_OFF_TEXT(objfile) \
621 ((objfile->sect_index_text == -1) \
622 ? (internal_error (__FILE__, __LINE__, _("sect_index_text not initialized")), -1) \
623 : objfile->sect_index_text)
625 /* Sometimes the .bss section is missing from the objfile, so we don't
626 want to die here. Let the users of SECT_OFF_BSS deal with an
627 uninitialized section index. */
628 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
630 /* Answer whether there is more than one object file loaded. */
632 #define MULTI_OBJFILE_P() (object_files && object_files->next)
634 #endif /* !defined (OBJFILES_H) */