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 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 */
32 /* This structure maintains information on a per-objfile basis about the
33 "entry point" of the objfile, and the scope within which the entry point
34 exists. It is possible that gdb will see more than one objfile that is
35 executable, each with its own entry point.
37 For example, for dynamically linked executables in SVR4, the dynamic linker
38 code is contained within the shared C library, which is actually executable
39 and is run by the kernel first when an exec is done of a user executable
40 that is dynamically linked. The dynamic linker within the shared C library
41 then maps in the various program segments in the user executable and jumps
42 to the user executable's recorded entry point, as if the call had been made
43 directly by the kernel.
45 The traditional gdb method of using this info was to use the
46 recorded entry point to set the entry-file's lowpc and highpc from
47 the debugging information, where these values are the starting
48 address (inclusive) and ending address (exclusive) of the
49 instruction space in the executable which correspond to the
50 "startup file", I.E. crt0.o in most cases. This file is assumed to
51 be a startup file and frames with pc's inside it are treated as
52 nonexistent. Setting these variables is necessary so that
53 backtraces do not fly off the bottom of the stack.
55 NOTE: cagney/2003-09-09: It turns out that this "traditional"
56 method doesn't work. Corinna writes: ``It turns out that the call
57 to test for "inside entry file" destroys a meaningful backtrace
58 under some conditions. E. g. the backtrace tests in the asm-source
59 testcase are broken for some targets. In this test the functions
60 are all implemented as part of one file and the testcase is not
61 necessarily linked with a start file (depending on the target).
62 What happens is, that the first frame is printed normaly and
63 following frames are treated as being inside the enttry file then.
64 This way, only the #0 frame is printed in the backtrace output.''
65 Ref "frame.c" "NOTE: vinschen/2003-04-01".
67 Gdb also supports an alternate method to avoid running off the bottom
70 There are two frames that are "special", the frame for the function
71 containing the process entry point, since it has no predecessor frame,
72 and the frame for the function containing the user code entry point
73 (the main() function), since all the predecessor frames are for the
74 process startup code. Since we have no guarantee that the linked
75 in startup modules have any debugging information that gdb can use,
76 we need to avoid following frame pointers back into frames that might
77 have been built in the startup code, as we might get hopelessly
78 confused. However, we almost always have debugging information
81 These variables are used to save the range of PC values which are
82 valid within the main() function and within the function containing
83 the process entry point. If we always consider the frame for
84 main() as the outermost frame when debugging user code, and the
85 frame for the process entry point function as the outermost frame
86 when debugging startup code, then all we have to do is have
87 DEPRECATED_FRAME_CHAIN_VALID return false whenever a frame's
88 current PC is within the range specified by these variables. In
89 essence, we set "ceilings" in the frame chain beyond which we will
90 not proceed when following the frame chain back up the stack.
92 A nice side effect is that we can still debug startup code without
93 running off the end of the frame chain, assuming that we have usable
94 debugging information in the startup modules, and if we choose to not
95 use the block at main, or can't find it for some reason, everything
96 still works as before. And if we have no startup code debugging
97 information but we do have usable information for main(), backtraces
98 from user code don't go wandering off into the startup code. */
103 /* The value we should use for this objects entry point.
104 The illegal/unknown value needs to be something other than 0, ~0
105 for instance, which is much less likely than 0. */
107 CORE_ADDR entry_point;
109 #define INVALID_ENTRY_POINT (~0) /* ~0 will not be in any file, we hope. */
113 /* Sections in an objfile. The section offsets are stored in the
118 struct bfd_section *the_bfd_section; /* BFD section pointer */
120 /* Objfile this section is part of. */
121 struct objfile *objfile;
123 /* True if this "overlay section" is mapped into an "overlay region". */
127 /* Relocation offset applied to S. */
128 #define obj_section_offset(s) \
129 (((s)->objfile->section_offsets)->offsets[(s)->the_bfd_section->index])
131 /* The memory address of section S (vma + offset). */
132 #define obj_section_addr(s) \
133 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \
134 + obj_section_offset (s))
136 /* The one-passed-the-end memory address of section S
137 (vma + size + offset). */
138 #define obj_section_endaddr(s) \
139 (bfd_get_section_vma ((s)->objfile->abfd, s->the_bfd_section) \
140 + bfd_get_section_size ((s)->the_bfd_section) \
141 + obj_section_offset (s))
143 /* The "objstats" structure provides a place for gdb to record some
144 interesting information about its internal state at runtime, on a
145 per objfile basis, such as information about the number of symbols
146 read, size of string table (if any), etc. */
150 int n_minsyms; /* Number of minimal symbols read */
151 int n_psyms; /* Number of partial symbols read */
152 int n_syms; /* Number of full symbols read */
153 int n_stabs; /* Number of ".stabs" read (if applicable) */
154 int n_types; /* Number of types */
155 int sz_strtab; /* Size of stringtable, (if applicable) */
158 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
159 #define OBJSTATS struct objstats stats
160 extern void print_objfile_statistics (void);
161 extern void print_symbol_bcache_statistics (void);
163 /* Number of entries in the minimal symbol hash table. */
164 #define MINIMAL_SYMBOL_HASH_SIZE 2039
166 /* Master structure for keeping track of each file from which
167 gdb reads symbols. There are several ways these get allocated: 1.
168 The main symbol file, symfile_objfile, set by the symbol-file command,
169 2. Additional symbol files added by the add-symbol-file command,
170 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
171 for modules that were loaded when GDB attached to a remote system
172 (see remote-vx.c). */
177 /* All struct objfile's are chained together by their next pointers.
178 The global variable "object_files" points to the first link in this
181 FIXME: There is a problem here if the objfile is reusable, and if
182 multiple users are to be supported. The problem is that the objfile
183 list is linked through a member of the objfile struct itself, which
184 is only valid for one gdb process. The list implementation needs to
185 be changed to something like:
187 struct list {struct list *next; struct objfile *objfile};
189 where the list structure is completely maintained separately within
192 struct objfile *next;
194 /* The object file's name, tilde-expanded and absolute.
195 Malloc'd; free it if you free this struct. */
199 /* Some flag bits for this objfile. */
201 unsigned short flags;
203 /* Each objfile points to a linked list of symtabs derived from this file,
204 one symtab structure for each compilation unit (source file). Each link
205 in the symtab list contains a backpointer to this objfile. */
207 struct symtab *symtabs;
209 /* Each objfile points to a linked list of partial symtabs derived from
210 this file, one partial symtab structure for each compilation unit
213 struct partial_symtab *psymtabs;
215 /* Map addresses to the entries of PSYMTABS. It would be more efficient to
216 have a map per the whole process but ADDRMAP cannot selectively remove
217 its items during FREE_OBJFILE. This mapping is already present even for
218 PARTIAL_SYMTABs which still have no corresponding full SYMTABs read. */
220 struct addrmap *psymtabs_addrmap;
222 /* List of freed partial symtabs, available for re-use */
224 struct partial_symtab *free_psymtabs;
226 /* The object file's BFD. Can be null if the objfile contains only
227 minimal symbols, e.g. the run time common symbols for SunOS4. */
231 /* The gdbarch associated with the BFD. Note that this gdbarch is
232 determined solely from BFD information, without looking at target
233 information. The gdbarch determined from a running target may
234 differ from this e.g. with respect to register types and names. */
236 struct gdbarch *gdbarch;
238 /* The modification timestamp of the object file, as of the last time
239 we read its symbols. */
243 /* Obstack to hold objects that should be freed when we load a new symbol
244 table from this object file. */
246 struct obstack objfile_obstack;
248 /* A byte cache where we can stash arbitrary "chunks" of bytes that
251 struct bcache *psymbol_cache; /* Byte cache for partial syms */
252 struct bcache *macro_cache; /* Byte cache for macros */
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 terminated
269 by a "null symbol", one that has a NULL pointer for the name and a zero
270 value for the address. This makes it easy to walk through the array
271 when passed a pointer to somewhere in the middle of it. There is also
272 a count of the number of symbols, which does not include the terminating
273 null symbol. The array itself, as well as all the data that it points
274 to, should be allocated on the objfile_obstack for this file. */
276 struct minimal_symbol *msymbols;
277 int minimal_symbol_count;
279 /* This is a hash table used to index the minimal symbols by name. */
281 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
283 /* This hash table is used to index the minimal symbols by their
286 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
288 /* Structure which keeps track of functions that manipulate objfile's
289 of the same type as this objfile. I.E. the function to read partial
290 symbols for example. Note that this structure is in statically
291 allocated memory, and is shared by all objfiles that use the
292 object module reader of this type. */
296 /* The per-objfile information about the entry point, the scope (file/func)
297 containing the entry point, and the scope of the user's main() func. */
299 struct entry_info ei;
301 /* Information about stabs. Will be filled in with a dbx_symfile_info
302 struct by those readers that need it. */
303 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
304 data points implemented using "data" and "num_data" below. For
305 an example of how to use this replacement, see "objfile_data"
308 struct dbx_symfile_info *deprecated_sym_stab_info;
310 /* Hook for information for use by the symbol reader (currently used
311 for information shared by sym_init and sym_read). It is
312 typically a pointer to malloc'd memory. The symbol reader's finish
313 function is responsible for freeing the memory thusly allocated. */
314 /* NOTE: cagney/2004-10-23: This has been replaced by per-objfile
315 data points implemented using "data" and "num_data" below. For
316 an example of how to use this replacement, see "objfile_data"
319 void *deprecated_sym_private;
321 /* Per objfile data-pointers required by other GDB modules. */
322 /* FIXME: kettenis/20030711: This mechanism could replace
323 deprecated_sym_stab_info and deprecated_sym_private
329 /* Set of relocation offsets to apply to each section.
330 Currently on the objfile_obstack (which makes no sense, but I'm
331 not sure it's harming anything).
333 These offsets indicate that all symbols (including partial and
334 minimal symbols) which have been read have been relocated by this
335 much. Symbols which are yet to be read need to be relocated by
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. Currently the table is stored on the
358 objfile_obstack (which makes no sense, but I'm not sure it's
359 harming anything). */
362 *sections, *sections_end;
364 /* Link to objfile that contains the debug symbols for this one.
365 One is loaded if this file has an debug link to an existing
366 debug file with the right checksum */
367 struct objfile *separate_debug_objfile;
369 /* If this is a separate debug object, this is used as a link to the
370 actual executable objfile. */
371 struct objfile *separate_debug_objfile_backlink;
373 /* Place to stash various statistics about this objfile */
376 /* A symtab that the C++ code uses to stash special symbols
377 associated to namespaces. */
379 /* FIXME/carlton-2003-06-27: Delete this in a few years once
380 "possible namespace symbols" go away. */
381 struct symtab *cp_namespace_symtab;
384 /* Defines for the objfile flag word. */
386 /* When using mapped/remapped predigested gdb symbol information, we need
387 a flag that indicates that we have previously done an initial symbol
388 table read from this particular objfile. We can't just look for the
389 absence of any of the three symbol tables (msymbols, psymtab, symtab)
390 because if the file has no symbols for example, none of these will
393 #define OBJF_SYMS (1 << 1) /* Have tried to read symbols */
395 /* When an object file has its functions reordered (currently Irix-5.2
396 shared libraries exhibit this behaviour), we will need an expensive
397 algorithm to locate a partial symtab or symtab via an address.
398 To avoid this penalty for normal object files, we use this flag,
399 whose setting is determined upon symbol table read in. */
401 #define OBJF_REORDERED (1 << 2) /* Functions are reordered */
403 /* Distinguish between an objfile for a shared library and a "vanilla"
404 objfile. (If not set, the objfile may still actually be a solib.
405 This can happen if the user created the objfile by using the
406 add-symbol-file command. GDB doesn't in that situation actually
407 check whether the file is a solib. Rather, the target's
408 implementation of the solib interface is responsible for setting
409 this flag when noticing solibs used by an inferior.) */
411 #define OBJF_SHARED (1 << 3) /* From a shared library */
413 /* User requested that this objfile be read in it's entirety. */
415 #define OBJF_READNOW (1 << 4) /* Immediate full read */
417 /* This objfile was created because the user explicitly caused it
418 (e.g., used the add-symbol-file command). This bit offers a way
419 for run_command to remove old objfile entries which are no longer
420 valid (i.e., are associated with an old inferior), but to preserve
421 ones that the user explicitly loaded via the add-symbol-file
424 #define OBJF_USERLOADED (1 << 5) /* User loaded */
426 /* The object file that the main symbol table was loaded from (e.g. the
427 argument to the "symbol-file" or "file" command). */
429 extern struct objfile *symfile_objfile;
431 /* The object file that contains the runtime common minimal symbols
432 for SunOS4. Note that this objfile has no associated BFD. */
434 extern struct objfile *rt_common_objfile;
436 /* When we need to allocate a new type, we need to know which objfile_obstack
437 to allocate the type on, since there is one for each objfile. The places
438 where types are allocated are deeply buried in function call hierarchies
439 which know nothing about objfiles, so rather than trying to pass a
440 particular objfile down to them, we just do an end run around them and
441 set current_objfile to be whatever objfile we expect to be using at the
442 time types are being allocated. For instance, when we start reading
443 symbols for a particular objfile, we set current_objfile to point to that
444 objfile, and when we are done, we set it back to NULL, to ensure that we
445 never put a type someplace other than where we are expecting to put it.
446 FIXME: Maybe we should review the entire type handling system and
447 see if there is a better way to avoid this problem. */
449 extern struct objfile *current_objfile;
451 /* All known objfiles are kept in a linked list. This points to the
452 root of this list. */
454 extern struct objfile *object_files;
456 /* Declarations for functions defined in objfiles.c */
458 extern struct objfile *allocate_objfile (bfd *, int);
460 extern struct gdbarch *get_objfile_arch (struct objfile *);
462 extern void init_entry_point_info (struct objfile *);
464 extern CORE_ADDR entry_point_address (void);
466 extern int build_objfile_section_table (struct objfile *);
468 extern void terminate_minimal_symbol_table (struct objfile *objfile);
470 extern void put_objfile_before (struct objfile *, struct objfile *);
472 extern void objfile_to_front (struct objfile *);
474 extern void unlink_objfile (struct objfile *);
476 extern void free_objfile (struct objfile *);
478 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
480 extern void free_all_objfiles (void);
482 extern void objfile_relocate (struct objfile *, struct section_offsets *);
484 extern int have_partial_symbols (void);
486 extern int have_full_symbols (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 extern struct obj_section *find_pc_sect_section (CORE_ADDR pc,
504 extern int in_plt_section (CORE_ADDR, char *);
506 /* Keep a registry of per-objfile data-pointers required by other GDB
509 extern const struct objfile_data *register_objfile_data (void);
510 extern const struct objfile_data *register_objfile_data_with_cleanup
511 (void (*cleanup) (struct objfile *, void *));
512 extern void clear_objfile_data (struct objfile *objfile);
513 extern void set_objfile_data (struct objfile *objfile,
514 const struct objfile_data *data, void *value);
515 extern void *objfile_data (struct objfile *objfile,
516 const struct objfile_data *data);
519 /* Traverse all object files. ALL_OBJFILES_SAFE works even if you delete
520 the objfile during the traversal. */
522 #define ALL_OBJFILES(obj) \
523 for ((obj) = object_files; (obj) != NULL; (obj) = (obj)->next)
525 #define ALL_OBJFILES_SAFE(obj,nxt) \
526 for ((obj) = object_files; \
527 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
530 /* Traverse all symtabs in one objfile. */
532 #define ALL_OBJFILE_SYMTABS(objfile, s) \
533 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
535 /* Traverse all psymtabs in one objfile. */
537 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
538 for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
540 /* Traverse all minimal symbols in one objfile. */
542 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
543 for ((m) = (objfile) -> msymbols; DEPRECATED_SYMBOL_NAME(m) != NULL; (m)++)
545 /* Traverse all symtabs in all objfiles. */
547 #define ALL_SYMTABS(objfile, s) \
548 ALL_OBJFILES (objfile) \
549 ALL_OBJFILE_SYMTABS (objfile, s)
551 /* Traverse all symtabs in all objfiles, skipping included files
552 (which share a blockvector with their primary symtab). */
554 #define ALL_PRIMARY_SYMTABS(objfile, s) \
555 ALL_OBJFILES (objfile) \
556 ALL_OBJFILE_SYMTABS (objfile, s) \
559 /* Traverse all psymtabs in all objfiles. */
561 #define ALL_PSYMTABS(objfile, p) \
562 ALL_OBJFILES (objfile) \
563 ALL_OBJFILE_PSYMTABS (objfile, p)
565 /* Traverse all minimal symbols in all objfiles. */
567 #define ALL_MSYMBOLS(objfile, m) \
568 ALL_OBJFILES (objfile) \
569 ALL_OBJFILE_MSYMBOLS (objfile, m)
571 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
572 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
574 #define ALL_OBJSECTIONS(objfile, osect) \
575 ALL_OBJFILES (objfile) \
576 ALL_OBJFILE_OSECTIONS (objfile, osect)
578 #define SECT_OFF_DATA(objfile) \
579 ((objfile->sect_index_data == -1) \
580 ? (internal_error (__FILE__, __LINE__, _("sect_index_data not initialized")), -1) \
581 : objfile->sect_index_data)
583 #define SECT_OFF_RODATA(objfile) \
584 ((objfile->sect_index_rodata == -1) \
585 ? (internal_error (__FILE__, __LINE__, _("sect_index_rodata not initialized")), -1) \
586 : objfile->sect_index_rodata)
588 #define SECT_OFF_TEXT(objfile) \
589 ((objfile->sect_index_text == -1) \
590 ? (internal_error (__FILE__, __LINE__, _("sect_index_text not initialized")), -1) \
591 : objfile->sect_index_text)
593 /* Sometimes the .bss section is missing from the objfile, so we don't
594 want to die here. Let the users of SECT_OFF_BSS deal with an
595 uninitialized section index. */
596 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
598 #endif /* !defined (OBJFILES_H) */