1 /* Definitions for symbol file management in GDB.
3 Copyright (C) 1992-2004, 2007-2012 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
20 #if !defined (OBJFILES_H)
23 #include "gdb_obstack.h" /* For obstack internals. */
24 #include "symfile.h" /* For struct psymbol_allocation_list. */
25 #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->obfd, 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->obfd, 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 /* Some objfile data is hung off the BFD. This enables sharing of the
164 data across all objfiles using the BFD. The data is stored in an
165 instance of this structure, and associated with the BFD using the
168 struct objfile_per_bfd_storage
170 /* The storage has an obstack of its own. */
172 struct obstack storage_obstack;
174 /* Byte cache for file names. */
176 struct bcache *filename_cache;
179 /* Master structure for keeping track of each file from which
180 gdb reads symbols. There are several ways these get allocated: 1.
181 The main symbol file, symfile_objfile, set by the symbol-file command,
182 2. Additional symbol files added by the add-symbol-file command,
183 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
184 for modules that were loaded when GDB attached to a remote system
185 (see remote-vx.c). */
190 /* All struct objfile's are chained together by their next pointers.
191 The program space field "objfiles" (frequently referenced via
192 the macro "object_files") points to the first link in this
195 struct objfile *next;
197 /* The object file's name, tilde-expanded and absolute. Malloc'd; free it
198 if you free this struct. This pointer is never NULL. */
204 /* Some flag bits for this objfile.
205 The values are defined by OBJF_*. */
207 unsigned short flags;
209 /* The program space associated with this objfile. */
211 struct program_space *pspace;
213 /* Each objfile points to a linked list of symtabs derived from this file,
214 one symtab structure for each compilation unit (source file). Each link
215 in the symtab list contains a backpointer to this objfile. */
217 struct symtab *symtabs;
219 /* Each objfile points to a linked list of partial symtabs derived from
220 this file, one partial symtab structure for each compilation unit
223 struct partial_symtab *psymtabs;
225 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
226 have a map per the whole process but ADDRMAP cannot selectively remove
227 its items during FREE_OBJFILE. This mapping is already present even for
228 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
230 struct addrmap *psymtabs_addrmap;
232 /* List of freed partial symtabs, available for re-use. */
234 struct partial_symtab *free_psymtabs;
236 /* The object file's BFD. Can be null if the objfile contains only
237 minimal symbols, e.g. the run time common symbols for SunOS4. */
241 /* The per-BFD data. Note that this is treated specially if OBFD
244 struct objfile_per_bfd_storage *per_bfd;
246 /* The gdbarch associated with the BFD. Note that this gdbarch is
247 determined solely from BFD information, without looking at target
248 information. The gdbarch determined from a running target may
249 differ from this e.g. with respect to register types and names. */
251 struct gdbarch *gdbarch;
253 /* The modification timestamp of the object file, as of the last time
254 we read its symbols. */
258 /* Cached 32-bit CRC as computed by gnu_debuglink_crc32. CRC32 is valid
263 /* Obstack to hold objects that should be freed when we load a new symbol
264 table from this object file. */
266 struct obstack objfile_obstack;
268 /* A byte cache where we can stash arbitrary "chunks" of bytes that
271 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
272 struct bcache *macro_cache; /* Byte cache for macros. */
274 /* Hash table for mapping symbol names to demangled names. Each
275 entry in the hash table is actually two consecutive strings,
276 both null-terminated; the first one is a mangled or linkage
277 name, and the second is the demangled name or just a zero byte
278 if the name doesn't demangle. */
279 struct htab *demangled_names_hash;
281 /* Vectors of all partial symbols read in from file. The actual data
282 is stored in the objfile_obstack. */
284 struct psymbol_allocation_list global_psymbols;
285 struct psymbol_allocation_list static_psymbols;
287 /* Each file contains a pointer to an array of minimal symbols for all
288 global symbols that are defined within the file. The array is
289 terminated by a "null symbol", one that has a NULL pointer for the
290 name and a zero value for the address. This makes it easy to walk
291 through the array when passed a pointer to somewhere in the middle
292 of it. There is also a count of the number of symbols, which does
293 not include the terminating null symbol. The array itself, as well
294 as all the data that it points to, should be allocated on the
295 objfile_obstack for this file. */
297 struct minimal_symbol *msymbols;
298 int minimal_symbol_count;
300 /* This is a hash table used to index the minimal symbols by name. */
302 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
304 /* This hash table is used to index the minimal symbols by their
307 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
309 /* Structure which keeps track of functions that manipulate objfile's
310 of the same type as this objfile. I.e. the function to read partial
311 symbols for example. Note that this structure is in statically
312 allocated memory, and is shared by all objfiles that use the
313 object module reader of this type. */
315 const struct sym_fns *sf;
317 /* The per-objfile information about the entry point, the scope (file/func)
318 containing the entry point, and the scope of the user's main() func. */
320 struct entry_info ei;
322 /* Information about stabs. Will be filled in with a dbx_symfile_info
323 struct by those readers that need it. */
324 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
325 data points implemented using "data" and "num_data" below. For
326 an example of how to use this replacement, see "objfile_data"
329 struct dbx_symfile_info *deprecated_sym_stab_info;
331 /* Hook for information for use by the symbol reader (currently used
332 for information shared by sym_init and sym_read). It is
333 typically a pointer to malloc'd memory. The symbol reader's finish
334 function is responsible for freeing the memory thusly allocated. */
335 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
336 data points implemented using "data" and "num_data" below. For
337 an example of how to use this replacement, see "objfile_data"
340 void *deprecated_sym_private;
342 /* Per objfile data-pointers required by other GDB modules. */
343 /* FIXME: kettenis/20030711: This mechanism could replace
344 deprecated_sym_stab_info and deprecated_sym_private
349 /* Set of relocation offsets to apply to each section.
350 The table is indexed by the_bfd_section->index, thus it is generally
351 as large as the number of sections in the binary.
352 The table is stored on the objfile_obstack.
354 These offsets indicate that all symbols (including partial and
355 minimal symbols) which have been read have been relocated by this
356 much. Symbols which are yet to be read need to be relocated by it. */
358 struct section_offsets *section_offsets;
361 /* Indexes in the section_offsets array. These are initialized by the
362 *_symfile_offsets() family of functions (som_symfile_offsets,
363 xcoff_symfile_offsets, default_symfile_offsets). In theory they
364 should correspond to the section indexes used by bfd for the
365 current objfile. The exception to this for the time being is the
371 int sect_index_rodata;
373 /* These pointers are used to locate the section table, which
374 among other things, is used to map pc addresses into sections.
375 SECTIONS points to the first entry in the table, and
376 SECTIONS_END points to the first location past the last entry
377 in the table. The table is stored on the objfile_obstack.
378 There is no particular order to the sections in this table, and it
379 only contains sections we care about (e.g. non-empty, SEC_ALLOC). */
381 struct obj_section *sections, *sections_end;
383 /* GDB allows to have debug symbols in separate object files. This is
384 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
385 Although this is a tree structure, GDB only support one level
386 (ie a separate debug for a separate debug is not supported). Note that
387 separate debug object are in the main chain and therefore will be
388 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
389 has a non-nul separate_debug_objfile_backlink. */
391 /* Link to the first separate debug object, if any. */
392 struct objfile *separate_debug_objfile;
394 /* If this is a separate debug object, this is used as a link to the
395 actual executable objfile. */
396 struct objfile *separate_debug_objfile_backlink;
398 /* If this is a separate debug object, this is a link to the next one
399 for the same executable objfile. */
400 struct objfile *separate_debug_objfile_link;
402 /* Place to stash various statistics about this objfile. */
405 /* A linked list of symbols created when reading template types or
406 function templates. These symbols are not stored in any symbol
407 table, so we have to keep them here to relocate them
409 struct symbol *template_symbols;
412 /* Defines for the objfile flag word. */
414 /* When an object file has its functions reordered (currently Irix-5.2
415 shared libraries exhibit this behaviour), we will need an expensive
416 algorithm to locate a partial symtab or symtab via an address.
417 To avoid this penalty for normal object files, we use this flag,
418 whose setting is determined upon symbol table read in. */
420 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
422 /* Distinguish between an objfile for a shared library and a "vanilla"
423 objfile. (If not set, the objfile may still actually be a solib.
424 This can happen if the user created the objfile by using the
425 add-symbol-file command. GDB doesn't in that situation actually
426 check whether the file is a solib. Rather, the target's
427 implementation of the solib interface is responsible for setting
428 this flag when noticing solibs used by an inferior.) */
430 #define OBJF_SHARED (1 << 1) /* From a shared library */
432 /* User requested that this objfile be read in it's entirety. */
434 #define OBJF_READNOW (1 << 2) /* Immediate full read */
436 /* This objfile was created because the user explicitly caused it
437 (e.g., used the add-symbol-file command). This bit offers a way
438 for run_command to remove old objfile entries which are no longer
439 valid (i.e., are associated with an old inferior), but to preserve
440 ones that the user explicitly loaded via the add-symbol-file
443 #define OBJF_USERLOADED (1 << 3) /* User loaded */
445 /* Set if we have tried to read partial symtabs for this objfile.
446 This is used to allow lazy reading of partial symtabs. */
448 #define OBJF_PSYMTABS_READ (1 << 4)
450 /* Set if this is the main symbol file
451 (as opposed to symbol file for dynamically loaded code). */
453 #define OBJF_MAINLINE (1 << 5)
455 /* The object file that contains the runtime common minimal symbols
456 for SunOS4. Note that this objfile has no associated BFD. */
458 extern struct objfile *rt_common_objfile;
460 /* Declarations for functions defined in objfiles.c */
462 extern struct objfile *allocate_objfile (bfd *, int);
464 extern struct gdbarch *get_objfile_arch (struct objfile *);
466 extern void init_entry_point_info (struct objfile *);
468 extern int entry_point_address_query (CORE_ADDR *entry_p);
470 extern CORE_ADDR entry_point_address (void);
472 extern void build_objfile_section_table (struct objfile *);
474 extern void terminate_minimal_symbol_table (struct objfile *objfile);
476 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
477 const struct objfile *);
479 extern void put_objfile_before (struct objfile *, struct objfile *);
481 extern void objfile_to_front (struct objfile *);
483 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
485 extern void unlink_objfile (struct objfile *);
487 extern void free_objfile (struct objfile *);
489 extern void free_objfile_separate_debug (struct objfile *);
491 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
493 extern void free_all_objfiles (void);
495 extern void objfile_relocate (struct objfile *, struct section_offsets *);
497 extern int objfile_has_partial_symbols (struct objfile *objfile);
499 extern int objfile_has_full_symbols (struct objfile *objfile);
501 extern int objfile_has_symbols (struct objfile *objfile);
503 extern int have_partial_symbols (void);
505 extern int have_full_symbols (void);
507 extern void objfiles_changed (void);
509 /* This operation deletes all objfile entries that represent solibs that
510 weren't explicitly loaded by the user, via e.g., the add-symbol-file
513 extern void objfile_purge_solibs (void);
515 /* Functions for dealing with the minimal symbol table, really a misc
516 address<->symbol mapping for things we don't have debug symbols for. */
518 extern int have_minimal_symbols (void);
520 extern struct obj_section *find_pc_section (CORE_ADDR pc);
522 extern int in_plt_section (CORE_ADDR, char *);
524 /* Keep a registry of per-objfile data-pointers required by other GDB
526 DECLARE_REGISTRY(objfile);
528 extern void default_iterate_over_objfiles_in_search_order
529 (struct gdbarch *gdbarch,
530 iterate_over_objfiles_in_search_order_cb_ftype *cb,
531 void *cb_data, struct objfile *current_objfile);
534 /* Traverse all object files in the current program space.
535 ALL_OBJFILES_SAFE works even if you delete the objfile during the
538 /* Traverse all object files in program space SS. */
540 #define ALL_PSPACE_OBJFILES(ss, obj) \
541 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
543 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
544 for ((obj) = ss->objfiles; \
545 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
548 #define ALL_OBJFILES(obj) \
549 for ((obj) = current_program_space->objfiles; \
553 #define ALL_OBJFILES_SAFE(obj,nxt) \
554 for ((obj) = current_program_space->objfiles; \
555 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
558 /* Traverse all symtabs in one objfile. */
560 #define ALL_OBJFILE_SYMTABS(objfile, s) \
561 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
563 /* Traverse all primary symtabs in one objfile. */
565 #define ALL_OBJFILE_PRIMARY_SYMTABS(objfile, s) \
566 ALL_OBJFILE_SYMTABS ((objfile), (s)) \
569 /* Traverse all minimal symbols in one objfile. */
571 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
572 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
574 /* Traverse all symtabs in all objfiles in the current symbol
577 #define ALL_SYMTABS(objfile, s) \
578 ALL_OBJFILES (objfile) \
579 ALL_OBJFILE_SYMTABS (objfile, s)
581 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
582 ALL_PSPACE_OBJFILES (ss, objfile) \
583 ALL_OBJFILE_SYMTABS (objfile, s)
585 /* Traverse all symtabs in all objfiles in the current program space,
586 skipping included files (which share a blockvector with their
589 #define ALL_PRIMARY_SYMTABS(objfile, s) \
590 ALL_OBJFILES (objfile) \
591 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
593 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
594 ALL_PSPACE_OBJFILES (ss, objfile) \
595 ALL_OBJFILE_PRIMARY_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 /* Reset the per-BFD storage area on OBJ. */
674 void set_objfile_per_bfd (struct objfile *obj);
676 #endif /* !defined (OBJFILES_H) */