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 /* 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 program space field "objfiles" (frequently referenced via
176 the macro "object_files") points to the first link in this
179 struct objfile *next;
181 /* The object file's name, tilde-expanded and absolute. Malloc'd; free it
182 if you free this struct. This pointer is never NULL. */
188 /* Some flag bits for this objfile.
189 The values are defined by OBJF_*. */
191 unsigned short flags;
193 /* The program space associated with this objfile. */
195 struct program_space *pspace;
197 /* Each objfile points to a linked list of symtabs derived from this file,
198 one symtab structure for each compilation unit (source file). Each link
199 in the symtab list contains a backpointer to this objfile. */
201 struct symtab *symtabs;
203 /* Each objfile points to a linked list of partial symtabs derived from
204 this file, one partial symtab structure for each compilation unit
207 struct partial_symtab *psymtabs;
209 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
210 have a map per the whole process but ADDRMAP cannot selectively remove
211 its items during FREE_OBJFILE. This mapping is already present even for
212 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
214 struct addrmap *psymtabs_addrmap;
216 /* List of freed partial symtabs, available for re-use. */
218 struct partial_symtab *free_psymtabs;
220 /* The object file's BFD. Can be null if the objfile contains only
221 minimal symbols, e.g. the run time common symbols for SunOS4. */
225 /* The gdbarch associated with the BFD. Note that this gdbarch is
226 determined solely from BFD information, without looking at target
227 information. The gdbarch determined from a running target may
228 differ from this e.g. with respect to register types and names. */
230 struct gdbarch *gdbarch;
232 /* The modification timestamp of the object file, as of the last time
233 we read its symbols. */
237 /* Cached 32-bit CRC as computed by gnu_debuglink_crc32. CRC32 is valid
242 /* Obstack to hold objects that should be freed when we load a new symbol
243 table from this object file. */
245 struct obstack objfile_obstack;
247 /* A byte cache where we can stash arbitrary "chunks" of bytes that
250 struct psymbol_bcache *psymbol_cache; /* Byte cache for partial syms. */
251 struct bcache *macro_cache; /* Byte cache for macros. */
252 struct bcache *filename_cache; /* Byte cache for file names. */
254 /* Hash table for mapping symbol names to demangled names. Each
255 entry in the hash table is actually two consecutive strings,
256 both null-terminated; the first one is a mangled or linkage
257 name, and the second is the demangled name or just a zero byte
258 if the name doesn't demangle. */
259 struct htab *demangled_names_hash;
261 /* Vectors of all partial symbols read in from file. The actual data
262 is stored in the objfile_obstack. */
264 struct psymbol_allocation_list global_psymbols;
265 struct psymbol_allocation_list static_psymbols;
267 /* Each file contains a pointer to an array of minimal symbols for all
268 global symbols that are defined within the file. The array is
269 terminated by a "null symbol", one that has a NULL pointer for the
270 name and a zero value for the address. This makes it easy to walk
271 through the array when passed a pointer to somewhere in the middle
272 of it. There is also a count of the number of symbols, which does
273 not include the terminating null symbol. The array itself, as well
274 as all the data that it points to, should be allocated on the
275 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. */
295 const struct sym_fns *sf;
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
329 /* Set of relocation offsets to apply to each section.
330 The table is indexed by the_bfd_section->index, thus it is generally
331 as large as the number of sections in the binary.
332 The table is stored on the objfile_obstack.
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 it. */
338 struct section_offsets *section_offsets;
341 /* Indexes in the section_offsets array. These are initialized by the
342 *_symfile_offsets() family of functions (som_symfile_offsets,
343 xcoff_symfile_offsets, default_symfile_offsets). In theory they
344 should correspond to the section indexes used by bfd for the
345 current objfile. The exception to this for the time being is the
351 int sect_index_rodata;
353 /* These pointers are used to locate the section table, which
354 among other things, is used to map pc addresses into sections.
355 SECTIONS points to the first entry in the table, and
356 SECTIONS_END points to the first location past the last entry
357 in the table. The table is stored on the objfile_obstack.
358 There is no particular order to the sections in this table, and it
359 only contains sections we care about (e.g. non-empty, SEC_ALLOC). */
361 struct obj_section *sections, *sections_end;
363 /* GDB allows to have debug symbols in separate object files. This is
364 used by .gnu_debuglink, ELF build id note and Mach-O OSO.
365 Although this is a tree structure, GDB only support one level
366 (ie a separate debug for a separate debug is not supported). Note that
367 separate debug object are in the main chain and therefore will be
368 visited by ALL_OBJFILES & co iterators. Separate debug objfile always
369 has a non-nul separate_debug_objfile_backlink. */
371 /* Link to the first separate debug object, if any. */
372 struct objfile *separate_debug_objfile;
374 /* If this is a separate debug object, this is used as a link to the
375 actual executable objfile. */
376 struct objfile *separate_debug_objfile_backlink;
378 /* If this is a separate debug object, this is a link to the next one
379 for the same executable objfile. */
380 struct objfile *separate_debug_objfile_link;
382 /* Place to stash various statistics about this objfile. */
385 /* A linked list of symbols created when reading template types or
386 function templates. These symbols are not stored in any symbol
387 table, so we have to keep them here to relocate them
389 struct symbol *template_symbols;
392 /* Defines for the objfile flag word. */
394 /* When an object file has its functions reordered (currently Irix-5.2
395 shared libraries exhibit this behaviour), we will need an expensive
396 algorithm to locate a partial symtab or symtab via an address.
397 To avoid this penalty for normal object files, we use this flag,
398 whose setting is determined upon symbol table read in. */
400 #define OBJF_REORDERED (1 << 0) /* Functions are reordered */
402 /* Distinguish between an objfile for a shared library and a "vanilla"
403 objfile. (If not set, the objfile may still actually be a solib.
404 This can happen if the user created the objfile by using the
405 add-symbol-file command. GDB doesn't in that situation actually
406 check whether the file is a solib. Rather, the target's
407 implementation of the solib interface is responsible for setting
408 this flag when noticing solibs used by an inferior.) */
410 #define OBJF_SHARED (1 << 1) /* From a shared library */
412 /* User requested that this objfile be read in it's entirety. */
414 #define OBJF_READNOW (1 << 2) /* Immediate full read */
416 /* This objfile was created because the user explicitly caused it
417 (e.g., used the add-symbol-file command). This bit offers a way
418 for run_command to remove old objfile entries which are no longer
419 valid (i.e., are associated with an old inferior), but to preserve
420 ones that the user explicitly loaded via the add-symbol-file
423 #define OBJF_USERLOADED (1 << 3) /* User loaded */
425 /* Set if we have tried to read partial symtabs for this objfile.
426 This is used to allow lazy reading of partial symtabs. */
428 #define OBJF_PSYMTABS_READ (1 << 4)
430 /* Set if this is the main symbol file
431 (as opposed to symbol file for dynamically loaded code). */
433 #define OBJF_MAINLINE (1 << 5)
435 /* The object file that contains the runtime common minimal symbols
436 for SunOS4. Note that this objfile has no associated BFD. */
438 extern struct objfile *rt_common_objfile;
440 /* Declarations for functions defined in objfiles.c */
442 extern struct objfile *allocate_objfile (bfd *, int);
444 extern struct gdbarch *get_objfile_arch (struct objfile *);
446 extern void init_entry_point_info (struct objfile *);
448 extern int entry_point_address_query (CORE_ADDR *entry_p);
450 extern CORE_ADDR entry_point_address (void);
452 extern void build_objfile_section_table (struct objfile *);
454 extern void terminate_minimal_symbol_table (struct objfile *objfile);
456 extern struct objfile *objfile_separate_debug_iterate (const struct objfile *,
457 const struct objfile *);
459 extern void put_objfile_before (struct objfile *, struct objfile *);
461 extern void objfile_to_front (struct objfile *);
463 extern void add_separate_debug_objfile (struct objfile *, struct objfile *);
465 extern void unlink_objfile (struct objfile *);
467 extern void free_objfile (struct objfile *);
469 extern void free_objfile_separate_debug (struct objfile *);
471 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
473 extern void free_all_objfiles (void);
475 extern void objfile_relocate (struct objfile *, struct section_offsets *);
477 extern int objfile_has_partial_symbols (struct objfile *objfile);
479 extern int objfile_has_full_symbols (struct objfile *objfile);
481 extern int objfile_has_symbols (struct objfile *objfile);
483 extern int have_partial_symbols (void);
485 extern int have_full_symbols (void);
487 extern void objfiles_changed (void);
489 /* This operation deletes all objfile entries that represent solibs that
490 weren't explicitly loaded by the user, via e.g., the add-symbol-file
493 extern void objfile_purge_solibs (void);
495 /* Functions for dealing with the minimal symbol table, really a misc
496 address<->symbol mapping for things we don't have debug symbols for. */
498 extern int have_minimal_symbols (void);
500 extern struct obj_section *find_pc_section (CORE_ADDR pc);
502 extern int in_plt_section (CORE_ADDR, char *);
504 /* Keep a registry of per-objfile data-pointers required by other GDB
506 DECLARE_REGISTRY(objfile);
508 extern void default_iterate_over_objfiles_in_search_order
509 (struct gdbarch *gdbarch,
510 iterate_over_objfiles_in_search_order_cb_ftype *cb,
511 void *cb_data, struct objfile *current_objfile);
514 /* Traverse all object files in the current program space.
515 ALL_OBJFILES_SAFE works even if you delete the objfile during the
518 /* Traverse all object files in program space SS. */
520 #define ALL_PSPACE_OBJFILES(ss, obj) \
521 for ((obj) = ss->objfiles; (obj) != NULL; (obj) = (obj)->next) \
523 #define ALL_PSPACE_OBJFILES_SAFE(ss, obj, nxt) \
524 for ((obj) = ss->objfiles; \
525 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
528 #define ALL_OBJFILES(obj) \
529 for ((obj) = current_program_space->objfiles; \
533 #define ALL_OBJFILES_SAFE(obj,nxt) \
534 for ((obj) = current_program_space->objfiles; \
535 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
538 /* Traverse all symtabs in one objfile. */
540 #define ALL_OBJFILE_SYMTABS(objfile, s) \
541 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
543 /* Traverse all primary symtabs in one objfile. */
545 #define ALL_OBJFILE_PRIMARY_SYMTABS(objfile, s) \
546 ALL_OBJFILE_SYMTABS ((objfile), (s)) \
549 /* Traverse all minimal symbols in one objfile. */
551 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
552 for ((m) = (objfile) -> msymbols; SYMBOL_LINKAGE_NAME(m) != NULL; (m)++)
554 /* Traverse all symtabs in all objfiles in the current symbol
557 #define ALL_SYMTABS(objfile, s) \
558 ALL_OBJFILES (objfile) \
559 ALL_OBJFILE_SYMTABS (objfile, s)
561 #define ALL_PSPACE_SYMTABS(ss, objfile, s) \
562 ALL_PSPACE_OBJFILES (ss, objfile) \
563 ALL_OBJFILE_SYMTABS (objfile, s)
565 /* Traverse all symtabs in all objfiles in the current program space,
566 skipping included files (which share a blockvector with their
569 #define ALL_PRIMARY_SYMTABS(objfile, s) \
570 ALL_OBJFILES (objfile) \
571 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
573 #define ALL_PSPACE_PRIMARY_SYMTABS(pspace, objfile, s) \
574 ALL_PSPACE_OBJFILES (ss, objfile) \
575 ALL_OBJFILE_PRIMARY_SYMTABS (objfile, s)
577 /* Traverse all minimal symbols in all objfiles in the current symbol
580 #define ALL_MSYMBOLS(objfile, m) \
581 ALL_OBJFILES (objfile) \
582 ALL_OBJFILE_MSYMBOLS (objfile, m)
584 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
585 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
587 /* Traverse all obj_sections in all objfiles in the current program
590 Note that this detects a "break" in the inner loop, and exits
591 immediately from the outer loop as well, thus, client code doesn't
592 need to know that this is implemented with a double for. The extra
593 hair is to make sure that a "break;" stops the outer loop iterating
594 as well, and both OBJFILE and OSECT are left unmodified:
596 - The outer loop learns about the inner loop's end condition, and
597 stops iterating if it detects the inner loop didn't reach its
598 end. In other words, the outer loop keeps going only if the
599 inner loop reached its end cleanly [(osect) ==
600 (objfile)->sections_end].
602 - OSECT is initialized in the outer loop initialization
603 expressions, such as if the inner loop has reached its end, so
604 the check mentioned above succeeds the first time.
606 - The trick to not clearing OBJFILE on a "break;" is, in the outer
607 loop's loop expression, advance OBJFILE, but iff the inner loop
608 reached its end. If not, there was a "break;", so leave OBJFILE
609 as is; the outer loop's conditional will break immediately as
610 well (as OSECT will be different from OBJFILE->sections_end). */
612 #define ALL_OBJSECTIONS(objfile, osect) \
613 for ((objfile) = current_program_space->objfiles, \
614 (objfile) != NULL ? ((osect) = (objfile)->sections_end) : 0; \
616 && (osect) == (objfile)->sections_end; \
617 ((osect) == (objfile)->sections_end \
618 ? ((objfile) = (objfile)->next, \
619 (objfile) != NULL ? (osect) = (objfile)->sections_end : 0) \
621 for ((osect) = (objfile)->sections; \
622 (osect) < (objfile)->sections_end; \
625 #define SECT_OFF_DATA(objfile) \
626 ((objfile->sect_index_data == -1) \
627 ? (internal_error (__FILE__, __LINE__, \
628 _("sect_index_data not initialized")), -1) \
629 : objfile->sect_index_data)
631 #define SECT_OFF_RODATA(objfile) \
632 ((objfile->sect_index_rodata == -1) \
633 ? (internal_error (__FILE__, __LINE__, \
634 _("sect_index_rodata not initialized")), -1) \
635 : objfile->sect_index_rodata)
637 #define SECT_OFF_TEXT(objfile) \
638 ((objfile->sect_index_text == -1) \
639 ? (internal_error (__FILE__, __LINE__, \
640 _("sect_index_text not initialized")), -1) \
641 : objfile->sect_index_text)
643 /* Sometimes the .bss section is missing from the objfile, so we don't
644 want to die here. Let the users of SECT_OFF_BSS deal with an
645 uninitialized section index. */
646 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
648 /* Answer whether there is more than one object file loaded. */
650 #define MULTI_OBJFILE_P() (object_files && object_files->next)
652 #endif /* !defined (OBJFILES_H) */