1 /* Definitions for symbol file management in GDB.
3 Copyright (C) 1992-2013 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"
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[gdb_bfd_section_index ((s)->objfile->obfd, (s)->the_bfd_section)])
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 /* Some objfile data is hung off the BFD. This enables sharing of the
165 data across all objfiles using the BFD. The data is stored in an
166 instance of this structure, and associated with the BFD using the
169 struct objfile_per_bfd_storage
171 /* The storage has an obstack of its own. */
173 struct obstack storage_obstack;
175 /* Byte cache for file names. */
177 struct bcache *filename_cache;
179 /* Byte cache for macros. */
180 struct bcache *macro_cache;
182 /* The gdbarch associated with the BFD. Note that this gdbarch is
183 determined solely from BFD information, without looking at target
184 information. The gdbarch determined from a running target may
185 differ from this e.g. with respect to register types and names. */
187 struct gdbarch *gdbarch;
189 /* Hash table for mapping symbol names to demangled names. Each
190 entry in the hash table is actually two consecutive strings,
191 both null-terminated; the first one is a mangled or linkage
192 name, and the second is the demangled name or just a zero byte
193 if the name doesn't demangle. */
194 struct htab *demangled_names_hash;
197 /* Master structure for keeping track of each file from which
198 gdb reads symbols. There are several ways these get allocated: 1.
199 The main symbol file, symfile_objfile, set by the symbol-file command,
200 2. Additional symbol files added by the add-symbol-file command,
201 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
202 for modules that were loaded when GDB attached to a remote system
203 (see remote-vx.c). */
208 /* All struct objfile's are chained together by their next pointers.
209 The program space field "objfiles" (frequently referenced via
210 the macro "object_files") points to the first link in this
213 struct objfile *next;
215 /* The object file's name, tilde-expanded and absolute. This
216 pointer is never NULL. This does not have to be freed; it is
217 guaranteed to have a lifetime at least as long as the objfile. */
223 /* Some flag bits for this objfile.
224 The values are defined by OBJF_*. */
226 unsigned short flags;
228 /* The program space associated with this objfile. */
230 struct program_space *pspace;
232 /* Each objfile points to a linked list of symtabs derived from this file,
233 one symtab structure for each compilation unit (source file). Each link
234 in the symtab list contains a backpointer to this objfile. */
236 struct symtab *symtabs;
238 /* Each objfile points to a linked list of partial symtabs derived from
239 this file, one partial symtab structure for each compilation unit
242 struct partial_symtab *psymtabs;
244 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
245 have a map per the whole process but ADDRMAP cannot selectively remove
246 its items during FREE_OBJFILE. This mapping is already present even for
247 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
249 struct addrmap *psymtabs_addrmap;
251 /* List of freed partial symtabs, available for re-use. */
253 struct partial_symtab *free_psymtabs;
255 /* The object file's BFD. Can be null if the objfile contains only
256 minimal symbols, e.g. the run time common symbols for SunOS4. */
260 /* The per-BFD data. Note that this is treated specially if OBFD
263 struct objfile_per_bfd_storage *per_bfd;
265 /* The modification timestamp of the object file, as of the last time
266 we read its symbols. */
270 /* Obstack to hold objects that should be freed when we load a new symbol
271 table from this object file. */
273 struct obstack objfile_obstack;
275 /* A byte cache where we can stash arbitrary "chunks" of bytes that
278 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
280 /* Vectors of all partial symbols read in from file. The actual data
281 is stored in the objfile_obstack. */
283 struct psymbol_allocation_list global_psymbols;
284 struct psymbol_allocation_list static_psymbols;
286 /* Each file contains a pointer to an array of minimal symbols for all
287 global symbols that are defined within the file. The array is
288 terminated by a "null symbol", one that has a NULL pointer for the
289 name and a zero value for the address. This makes it easy to walk
290 through the array when passed a pointer to somewhere in the middle
291 of it. There is also a count of the number of symbols, which does
292 not include the terminating null symbol. The array itself, as well
293 as all the data that it points to, should be allocated on the
294 objfile_obstack for this file. */
296 struct minimal_symbol *msymbols;
297 int minimal_symbol_count;
299 /* This is a hash table used to index the minimal symbols by name. */
301 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
303 /* This hash table is used to index the minimal symbols by their
306 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
308 /* Structure which keeps track of functions that manipulate objfile's
309 of the same type as this objfile. I.e. the function to read partial
310 symbols for example. Note that this structure is in statically
311 allocated memory, and is shared by all objfiles that use the
312 object module reader of this type. */
314 const struct sym_fns *sf;
316 /* The per-objfile information about the entry point, the scope (file/func)
317 containing the entry point, and the scope of the user's main() func. */
319 struct entry_info ei;
321 /* Per objfile data-pointers required by other GDB modules. */
325 /* Set of relocation offsets to apply to each section.
326 The table is indexed by the_bfd_section->index, thus it is generally
327 as large as the number of sections in the binary.
328 The table is stored on the objfile_obstack.
330 These offsets indicate that all symbols (including partial and
331 minimal symbols) which have been read have been relocated by this
332 much. Symbols which are yet to be read need to be relocated by it. */
334 struct section_offsets *section_offsets;
337 /* Indexes in the section_offsets array. These are initialized by the
338 *_symfile_offsets() family of functions (som_symfile_offsets,
339 xcoff_symfile_offsets, default_symfile_offsets). In theory they
340 should correspond to the section indexes used by bfd for the
341 current objfile. The exception to this for the time being is the
347 int sect_index_rodata;
349 /* These pointers are used to locate the section table, which
350 among other things, is used to map pc addresses into sections.
351 SECTIONS points to the first entry in the table, and
352 SECTIONS_END points to the first location past the last entry
353 in the table. The table is stored on the objfile_obstack. The
354 sections are indexed by the BFD section index; but the
355 structure data is only valid for certain sections
356 (e.g. non-empty, SEC_ALLOC). */
358 struct obj_section *sections, *sections_end;
360 /* GDB allows to have debug symbols in separate object files. This is
361 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
362 Although this is a tree structure, GDB only support one level
363 (ie a separate debug for a separate debug is not supported). Note that
364 separate debug object are in the main chain and therefore will be
365 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
366 has a non-nul separate_debug_objfile_backlink. */
368 /* Link to the first separate debug object, if any. */
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 /* If this is a separate debug object, this is a link to the next one
376 for the same executable objfile. */
377 struct objfile *separate_debug_objfile_link;
379 /* Place to stash various statistics about this objfile. */
382 /* A linked list of symbols created when reading template types or
383 function templates. These symbols are not stored in any symbol
384 table, so we have to keep them here to relocate them
386 struct symbol *template_symbols;
389 /* Defines for the objfile flag word. */
391 /* When an object file has its functions reordered (currently Irix-5.2
392 shared libraries exhibit this behaviour), we will need an expensive
393 algorithm to locate a partial symtab or symtab via an address.
394 To avoid this penalty for normal object files, we use this flag,
395 whose setting is determined upon symbol table read in. */
397 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
399 /* Distinguish between an objfile for a shared library and a "vanilla"
400 objfile. (If not set, the objfile may still actually be a solib.
401 This can happen if the user created the objfile by using the
402 add-symbol-file command. GDB doesn't in that situation actually
403 check whether the file is a solib. Rather, the target's
404 implementation of the solib interface is responsible for setting
405 this flag when noticing solibs used by an inferior.) */
407 #define OBJF_SHARED (1 << 1) /* From a shared library */
409 /* User requested that this objfile be read in it's entirety. */
411 #define OBJF_READNOW (1 << 2) /* Immediate full read */
413 /* This objfile was created because the user explicitly caused it
414 (e.g., used the add-symbol-file command). This bit offers a way
415 for run_command to remove old objfile entries which are no longer
416 valid (i.e., are associated with an old inferior), but to preserve
417 ones that the user explicitly loaded via the add-symbol-file
420 #define OBJF_USERLOADED (1 << 3) /* User loaded */
422 /* Set if we have tried to read partial symtabs for this objfile.
423 This is used to allow lazy reading of partial symtabs. */
425 #define OBJF_PSYMTABS_READ (1 << 4)
427 /* Set if this is the main symbol file
428 (as opposed to symbol file for dynamically loaded code). */
430 #define OBJF_MAINLINE (1 << 5)
432 /* ORIGINAL_NAME and OBFD->FILENAME correspond to text description unrelated to
433 filesystem names. It can be for example "<image in memory>". */
435 #define OBJF_NOT_FILENAME (1 << 6)
437 /* Declarations for functions defined in objfiles.c */
439 extern struct objfile *allocate_objfile (bfd *, const char *name, int);
441 extern struct gdbarch *get_objfile_arch (struct objfile *);
443 extern int entry_point_address_query (CORE_ADDR *entry_p);
445 extern CORE_ADDR entry_point_address (void);
447 extern void build_objfile_section_table (struct objfile *);
449 extern void terminate_minimal_symbol_table (struct objfile *objfile);
451 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
452 const struct objfile *);
454 extern void put_objfile_before (struct objfile *, struct objfile *);
456 extern void objfile_to_front (struct objfile *);
458 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
460 extern void unlink_objfile (struct objfile *);
462 extern void free_objfile (struct objfile *);
464 extern void free_objfile_separate_debug (struct objfile *);
466 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
468 extern void free_all_objfiles (void);
470 extern void objfile_relocate (struct objfile *, const struct section_offsets *);
471 extern void objfile_rebase (struct objfile *, CORE_ADDR);
473 extern int objfile_has_partial_symbols (struct objfile *objfile);
475 extern int objfile_has_full_symbols (struct objfile *objfile);
477 extern int objfile_has_symbols (struct objfile *objfile);
479 extern int have_partial_symbols (void);
481 extern int have_full_symbols (void);
483 extern void objfile_set_sym_fns (struct objfile *objfile,
484 const struct sym_fns *sf);
486 extern void objfiles_changed (void);
488 /* This operation deletes all objfile entries that represent solibs that
489 weren't explicitly loaded by the user, via e.g., the add-symbol-file
492 extern void objfile_purge_solibs (void);
494 /* Functions for dealing with the minimal symbol table, really a misc
495 address<->symbol mapping for things we don't have debug symbols for. */
497 extern int have_minimal_symbols (void);
499 extern struct obj_section *find_pc_section (CORE_ADDR pc);
501 /* Return non-zero if PC is in a section called NAME. */
502 extern int pc_in_section (CORE_ADDR, char *);
504 /* Return non-zero if PC is in a SVR4-style procedure linkage table
508 in_plt_section (CORE_ADDR pc)
510 return pc_in_section (pc, ".plt");
513 /* Keep a registry of per-objfile data-pointers required by other GDB
515 DECLARE_REGISTRY(objfile);
517 /* In normal use, the section map will be rebuilt by find_pc_section
518 if objfiles have been added, removed or relocated since it was last
519 called. Calling inhibit_section_map_updates will inhibit this
520 behavior until resume_section_map_updates is called. If you call
521 inhibit_section_map_updates you must ensure that every call to
522 find_pc_section in the inhibited region relates to a section that
523 is already in the section map and has not since been removed or
525 extern void inhibit_section_map_updates (struct program_space *pspace);
527 /* Resume automatically rebuilding the section map as required. */
528 extern void resume_section_map_updates (struct program_space *pspace);
530 /* Version of the above suitable for use as a cleanup. */
531 extern void resume_section_map_updates_cleanup (void *arg);
533 extern void default_iterate_over_objfiles_in_search_order
534 (struct gdbarch *gdbarch,
535 iterate_over_objfiles_in_search_order_cb_ftype *cb,
536 void *cb_data, struct objfile *current_objfile);
539 /* Traverse all object files in the current program space.
540 ALL_OBJFILES_SAFE works even if you delete the objfile during the
543 /* Traverse all object files in program space SS. */
545 #define ALL_PSPACE_OBJFILES(ss, obj) \
546 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next)
548 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
549 for ((obj) = ss->objfiles; \
550 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
553 #define ALL_OBJFILES(obj) \
554 for ((obj) = current_program_space->objfiles; \
558 #define ALL_OBJFILES_SAFE(obj,nxt) \
559 for ((obj) = current_program_space->objfiles; \
560 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
563 /* Traverse all symtabs in one objfile. */
565 #define ALL_OBJFILE_SYMTABS(objfile, s) \
566 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
568 /* Traverse all primary symtabs in one objfile. */
570 #define ALL_OBJFILE_PRIMARY_SYMTABS(objfile, s) \
571 ALL_OBJFILE_SYMTABS ((objfile), (s)) \
574 /* Traverse all minimal symbols in one objfile. */
576 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
577 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
579 /* Traverse all symtabs in all objfiles in the current symbol
582 #define ALL_SYMTABS(objfile, s) \
583 ALL_OBJFILES (objfile) \
584 ALL_OBJFILE_SYMTABS (objfile, s)
586 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
587 ALL_PSPACE_OBJFILES (ss, objfile) \
588 ALL_OBJFILE_SYMTABS (objfile, s)
590 /* Traverse all symtabs in all objfiles in the current program space,
591 skipping included files (which share a blockvector with their
594 #define ALL_PRIMARY_SYMTABS(objfile, s) \
595 ALL_OBJFILES (objfile) \
596 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
598 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
599 ALL_PSPACE_OBJFILES (ss, objfile) \
600 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
602 /* Traverse all minimal symbols in all objfiles in the current symbol
605 #define ALL_MSYMBOLS(objfile, m) \
606 ALL_OBJFILES (objfile) \
607 ALL_OBJFILE_MSYMBOLS (objfile, m)
609 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
610 for (osect = objfile->sections; osect < objfile->sections_end; osect++) \
611 if (osect->the_bfd_section == NULL) \
617 /* Traverse all obj_sections in all objfiles in the current program
620 Note that this detects a "break" in the inner loop, and exits
621 immediately from the outer loop as well, thus, client code doesn't
622 need to know that this is implemented with a double for. The extra
623 hair is to make sure that a "break;" stops the outer loop iterating
624 as well, and both OBJFILE and OSECT are left unmodified:
626 - The outer loop learns about the inner loop's end condition, and
627 stops iterating if it detects the inner loop didn't reach its
628 end. In other words, the outer loop keeps going only if the
629 inner loop reached its end cleanly [(osect) ==
630 (objfile)->sections_end].
632 - OSECT is initialized in the outer loop initialization
633 expressions, such as if the inner loop has reached its end, so
634 the check mentioned above succeeds the first time.
636 - The trick to not clearing OBJFILE on a "break;" is, in the outer
637 loop's loop expression, advance OBJFILE, but iff the inner loop
638 reached its end. If not, there was a "break;", so leave OBJFILE
639 as is; the outer loop's conditional will break immediately as
640 well (as OSECT will be different from OBJFILE->sections_end). */
642 #define ALL_OBJSECTIONS(objfile, osect) \
643 for ((objfile) = current_program_space->objfiles, \
644 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
646 && (osect) == (objfile)->sections_end; \
647 ((osect) == (objfile)->sections_end \
648 ? ((objfile) = (objfile)->next, \
649 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
651 ALL_OBJFILE_OSECTIONS (objfile, osect)
653 #define SECT_OFF_DATA(objfile) \
654 ((objfile->sect_index_data == -1) \
655 ? (internal_error (__FILE__, __LINE__, \
656 _("sect_index_data not initialized")), -1) \
657 : objfile->sect_index_data)
659 #define SECT_OFF_RODATA(objfile) \
660 ((objfile->sect_index_rodata == -1) \
661 ? (internal_error (__FILE__, __LINE__, \
662 _("sect_index_rodata not initialized")), -1) \
663 : objfile->sect_index_rodata)
665 #define SECT_OFF_TEXT(objfile) \
666 ((objfile->sect_index_text == -1) \
667 ? (internal_error (__FILE__, __LINE__, \
668 _("sect_index_text not initialized")), -1) \
669 : objfile->sect_index_text)
671 /* Sometimes the .bss section is missing from the objfile, so we don't
672 want to die here. Let the users of SECT_OFF_BSS deal with an
673 uninitialized section index. */
674 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
676 /* Answer whether there is more than one object file loaded. */
678 #define MULTI_OBJFILE_P() (object_files && object_files->next)
680 /* Reset the per-BFD storage area on OBJ. */
682 void set_objfile_per_bfd (struct objfile *obj);
684 const char *objfile_name (const struct objfile *objfile);
686 #endif /* !defined (OBJFILES_H) */