1 /* Definitions for symbol file management in GDB.
3 Copyright 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 2001, 2002, 2003, 2004 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 2 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, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
23 #if !defined (OBJFILES_H)
26 #include "gdb_obstack.h" /* For obstack internals. */
27 #include "symfile.h" /* For struct psymbol_allocation_list */
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. */
105 /* The value we should use for this objects entry point.
106 The illegal/unknown value needs to be something other than 0, ~0
107 for instance, which is much less likely than 0. */
109 CORE_ADDR entry_point
;
111 #define INVALID_ENTRY_POINT (~0) /* ~0 will not be in any file, we hope. */
115 /* Sections in an objfile.
117 It is strange that we have both this notion of "sections"
118 and the one used by section_offsets. Section as used
119 here, (currently at least) means a BFD section, and the sections
120 are set up from the BFD sections in allocate_objfile.
122 The sections in section_offsets have their meaning determined by
123 the symbol format, and they are set up by the sym_offsets function
124 for that symbol file format.
126 I'm not sure this could or should be changed, however. */
130 CORE_ADDR addr
; /* lowest address in section */
131 CORE_ADDR endaddr
; /* 1+highest address in section */
133 /* This field is being used for nefarious purposes by syms_from_objfile.
134 It is said to be redundant with section_offsets; it's not really being
135 used that way, however, it's some sort of hack I don't understand
136 and am not going to try to eliminate (yet, anyway). FIXME.
138 It was documented as "offset between (end)addr and actual memory
139 addresses", but that's not true; addr & endaddr are actual memory
143 struct bfd_section
*the_bfd_section
; /* BFD section pointer */
145 /* Objfile this section is part of. */
146 struct objfile
*objfile
;
148 /* True if this "overlay section" is mapped into an "overlay region". */
152 /* An import entry contains information about a symbol that
153 is used in this objfile but not defined in it, and so needs
154 to be imported from some other objfile */
155 /* Currently we just store the name; no attributes. 1997-08-05 */
156 typedef char *ImportEntry
;
159 /* An export entry contains information about a symbol that
160 is defined in this objfile and available for use in other
164 char *name
; /* name of exported symbol */
165 int address
; /* offset subject to relocation */
166 /* Currently no other attributes 1997-08-05 */
171 /* The "objstats" structure provides a place for gdb to record some
172 interesting information about its internal state at runtime, on a
173 per objfile basis, such as information about the number of symbols
174 read, size of string table (if any), etc. */
178 int n_minsyms
; /* Number of minimal symbols read */
179 int n_psyms
; /* Number of partial symbols read */
180 int n_syms
; /* Number of full symbols read */
181 int n_stabs
; /* Number of ".stabs" read (if applicable) */
182 int n_types
; /* Number of types */
183 int sz_strtab
; /* Size of stringtable, (if applicable) */
186 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
187 #define OBJSTATS struct objstats stats
188 extern void print_objfile_statistics (void);
189 extern void print_symbol_bcache_statistics (void);
191 /* Number of entries in the minimal symbol hash table. */
192 #define MINIMAL_SYMBOL_HASH_SIZE 2039
194 /* Master structure for keeping track of each file from which
195 gdb reads symbols. There are several ways these get allocated: 1.
196 The main symbol file, symfile_objfile, set by the symbol-file command,
197 2. Additional symbol files added by the add-symbol-file command,
198 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
199 for modules that were loaded when GDB attached to a remote system
200 (see remote-vx.c). */
205 /* All struct objfile's are chained together by their next pointers.
206 The global variable "object_files" points to the first link in this
209 FIXME: There is a problem here if the objfile is reusable, and if
210 multiple users are to be supported. The problem is that the objfile
211 list is linked through a member of the objfile struct itself, which
212 is only valid for one gdb process. The list implementation needs to
213 be changed to something like:
215 struct list {struct list *next; struct objfile *objfile};
217 where the list structure is completely maintained separately within
220 struct objfile
*next
;
222 /* The object file's name, tilde-expanded and absolute.
223 Malloc'd; free it if you free this struct. */
227 /* Some flag bits for this objfile. */
229 unsigned short flags
;
231 /* Each objfile points to a linked list of symtabs derived from this file,
232 one symtab structure for each compilation unit (source file). Each link
233 in the symtab list contains a backpointer to this objfile. */
235 struct symtab
*symtabs
;
237 /* Each objfile points to a linked list of partial symtabs derived from
238 this file, one partial symtab structure for each compilation unit
241 struct partial_symtab
*psymtabs
;
243 /* List of freed partial symtabs, available for re-use */
245 struct partial_symtab
*free_psymtabs
;
247 /* The object file's BFD. Can be null if the objfile contains only
248 minimal symbols, e.g. the run time common symbols for SunOS4. */
252 /* The modification timestamp of the object file, as of the last time
253 we read its symbols. */
257 /* Obstack to hold objects that should be freed when we load a new symbol
258 table from this object file. */
260 struct obstack objfile_obstack
;
262 /* A byte cache where we can stash arbitrary "chunks" of bytes that
265 struct bcache
*psymbol_cache
; /* Byte cache for partial syms */
266 struct bcache
*macro_cache
; /* Byte cache for macros */
268 /* Hash table for mapping symbol names to demangled names. Each
269 entry in the hash table is actually two consecutive strings,
270 both null-terminated; the first one is a mangled or linkage
271 name, and the second is the demangled name or just a zero byte
272 if the name doesn't demangle. */
273 struct htab
*demangled_names_hash
;
275 /* Vectors of all partial symbols read in from file. The actual data
276 is stored in the objfile_obstack. */
278 struct psymbol_allocation_list global_psymbols
;
279 struct psymbol_allocation_list static_psymbols
;
281 /* Each file contains a pointer to an array of minimal symbols for all
282 global symbols that are defined within the file. The array is terminated
283 by a "null symbol", one that has a NULL pointer for the name and a zero
284 value for the address. This makes it easy to walk through the array
285 when passed a pointer to somewhere in the middle of it. There is also
286 a count of the number of symbols, which does not include the terminating
287 null symbol. The array itself, as well as all the data that it points
288 to, should be allocated on the objfile_obstack for this file. */
290 struct minimal_symbol
*msymbols
;
291 int minimal_symbol_count
;
293 /* This is a hash table used to index the minimal symbols by name. */
295 struct minimal_symbol
*msymbol_hash
[MINIMAL_SYMBOL_HASH_SIZE
];
297 /* This hash table is used to index the minimal symbols by their
300 struct minimal_symbol
*msymbol_demangled_hash
[MINIMAL_SYMBOL_HASH_SIZE
];
302 /* For object file formats which don't specify fundamental types, gdb
303 can create such types. For now, it maintains a vector of pointers
304 to these internally created fundamental types on a per objfile basis,
305 however it really should ultimately keep them on a per-compilation-unit
306 basis, to account for linkage-units that consist of a number of
307 compilation units that may have different fundamental types, such as
308 linking C modules with ADA modules, or linking C modules that are
309 compiled with 32-bit ints with C modules that are compiled with 64-bit
310 ints (not inherently evil with a smarter linker). */
312 struct type
**fundamental_types
;
314 /* The mmalloc() malloc-descriptor for this objfile if we are using
315 the memory mapped malloc() package to manage storage for this objfile's
316 data. NULL if we are not. */
320 /* The file descriptor that was used to obtain the mmalloc descriptor
321 for this objfile. If we call mmalloc_detach with the malloc descriptor
322 we should then close this file descriptor. */
326 /* Structure which keeps track of functions that manipulate objfile's
327 of the same type as this objfile. I.E. the function to read partial
328 symbols for example. Note that this structure is in statically
329 allocated memory, and is shared by all objfiles that use the
330 object module reader of this type. */
334 /* The per-objfile information about the entry point, the scope (file/func)
335 containing the entry point, and the scope of the user's main() func. */
337 struct entry_info ei
;
339 /* Information about stabs. Will be filled in with a dbx_symfile_info
340 struct by those readers that need it. */
342 struct dbx_symfile_info
*sym_stab_info
;
344 /* Hook for information for use by the symbol reader (currently used
345 for information shared by sym_init and sym_read). It is
346 typically a pointer to malloc'd memory. The symbol reader's finish
347 function is responsible for freeing the memory thusly allocated. */
351 /* Hook for target-architecture-specific information. This must
352 point to memory allocated on one of the obstacks in this objfile,
353 so that it gets freed automatically when reading a new object
358 /* Per objfile data-pointers required by other GDB modules. */
359 /* FIXME: kettenis/20030711: This mechanism could replace
360 sym_stab_info, sym_private and obj_private entirely. */
365 /* Set of relocation offsets to apply to each section.
366 Currently on the objfile_obstack (which makes no sense, but I'm
367 not sure it's harming anything).
369 These offsets indicate that all symbols (including partial and
370 minimal symbols) which have been read have been relocated by this
371 much. Symbols which are yet to be read need to be relocated by
374 struct section_offsets
*section_offsets
;
377 /* Indexes in the section_offsets array. These are initialized by the
378 *_symfile_offsets() family of functions (som_symfile_offsets,
379 xcoff_symfile_offsets, default_symfile_offsets). In theory they
380 should correspond to the section indexes used by bfd for the
381 current objfile. The exception to this for the time being is the
387 int sect_index_rodata
;
389 /* These pointers are used to locate the section table, which
390 among other things, is used to map pc addresses into sections.
391 SECTIONS points to the first entry in the table, and
392 SECTIONS_END points to the first location past the last entry
393 in the table. Currently the table is stored on the
394 objfile_obstack (which makes no sense, but I'm not sure it's
395 harming anything). */
398 *sections
, *sections_end
;
400 /* Imported symbols */
401 /* FIXME: ezannoni 2004-02-10: This is just SOM (HP) specific (see
402 somread.c). It should not pollute generic objfiles. */
403 ImportEntry
*import_list
;
404 int import_list_size
;
406 /* Exported symbols */
407 /* FIXME: ezannoni 2004-02-10: This is just SOM (HP) specific (see
408 somread.c). It should not pollute generic objfiles. */
409 ExportEntry
*export_list
;
410 int export_list_size
;
412 /* Link to objfile that contains the debug symbols for this one.
413 One is loaded if this file has an debug link to an existing
414 debug file with the right checksum */
415 struct objfile
*separate_debug_objfile
;
417 /* If this is a separate debug object, this is used as a link to the
418 actual executable objfile. */
419 struct objfile
*separate_debug_objfile_backlink
;
421 /* Place to stash various statistics about this objfile */
424 /* A symtab that the C++ code uses to stash special symbols
425 associated to namespaces. */
427 /* FIXME/carlton-2003-06-27: Delete this in a few years once
428 "possible namespace symbols" go away. */
429 struct symtab
*cp_namespace_symtab
;
432 /* Defines for the objfile flag word. */
434 /* When using mapped/remapped predigested gdb symbol information, we need
435 a flag that indicates that we have previously done an initial symbol
436 table read from this particular objfile. We can't just look for the
437 absence of any of the three symbol tables (msymbols, psymtab, symtab)
438 because if the file has no symbols for example, none of these will
441 #define OBJF_SYMS (1 << 1) /* Have tried to read symbols */
443 /* When an object file has its functions reordered (currently Irix-5.2
444 shared libraries exhibit this behaviour), we will need an expensive
445 algorithm to locate a partial symtab or symtab via an address.
446 To avoid this penalty for normal object files, we use this flag,
447 whose setting is determined upon symbol table read in. */
449 #define OBJF_REORDERED (1 << 2) /* Functions are reordered */
451 /* Distinguish between an objfile for a shared library and a "vanilla"
452 objfile. (If not set, the objfile may still actually be a solib.
453 This can happen if the user created the objfile by using the
454 add-symbol-file command. GDB doesn't in that situation actually
455 check whether the file is a solib. Rather, the target's
456 implementation of the solib interface is responsible for setting
457 this flag when noticing solibs used by an inferior.) */
459 #define OBJF_SHARED (1 << 3) /* From a shared library */
461 /* User requested that this objfile be read in it's entirety. */
463 #define OBJF_READNOW (1 << 4) /* Immediate full read */
465 /* This objfile was created because the user explicitly caused it
466 (e.g., used the add-symbol-file command). This bit offers a way
467 for run_command to remove old objfile entries which are no longer
468 valid (i.e., are associated with an old inferior), but to preserve
469 ones that the user explicitly loaded via the add-symbol-file
472 #define OBJF_USERLOADED (1 << 5) /* User loaded */
474 /* The object file that the main symbol table was loaded from (e.g. the
475 argument to the "symbol-file" or "file" command). */
477 extern struct objfile
*symfile_objfile
;
479 /* The object file that contains the runtime common minimal symbols
480 for SunOS4. Note that this objfile has no associated BFD. */
482 extern struct objfile
*rt_common_objfile
;
484 /* When we need to allocate a new type, we need to know which objfile_obstack
485 to allocate the type on, since there is one for each objfile. The places
486 where types are allocated are deeply buried in function call hierarchies
487 which know nothing about objfiles, so rather than trying to pass a
488 particular objfile down to them, we just do an end run around them and
489 set current_objfile to be whatever objfile we expect to be using at the
490 time types are being allocated. For instance, when we start reading
491 symbols for a particular objfile, we set current_objfile to point to that
492 objfile, and when we are done, we set it back to NULL, to ensure that we
493 never put a type someplace other than where we are expecting to put it.
494 FIXME: Maybe we should review the entire type handling system and
495 see if there is a better way to avoid this problem. */
497 extern struct objfile
*current_objfile
;
499 /* All known objfiles are kept in a linked list. This points to the
500 root of this list. */
502 extern struct objfile
*object_files
;
504 /* Declarations for functions defined in objfiles.c */
506 extern struct objfile
*allocate_objfile (bfd
*, int);
508 extern void init_entry_point_info (struct objfile
*);
510 extern CORE_ADDR
entry_point_address (void);
512 extern int build_objfile_section_table (struct objfile
*);
514 extern void terminate_minimal_symbol_table (struct objfile
*objfile
);
516 extern void put_objfile_before (struct objfile
*, struct objfile
*);
518 extern void objfile_to_front (struct objfile
*);
520 extern void unlink_objfile (struct objfile
*);
522 extern void free_objfile (struct objfile
*);
524 extern struct cleanup
*make_cleanup_free_objfile (struct objfile
*);
526 extern void free_all_objfiles (void);
528 extern void objfile_relocate (struct objfile
*, struct section_offsets
*);
530 extern int have_partial_symbols (void);
532 extern int have_full_symbols (void);
534 /* This operation deletes all objfile entries that represent solibs that
535 weren't explicitly loaded by the user, via e.g., the add-symbol-file
538 extern void objfile_purge_solibs (void);
540 /* Functions for dealing with the minimal symbol table, really a misc
541 address<->symbol mapping for things we don't have debug symbols for. */
543 extern int have_minimal_symbols (void);
545 extern struct obj_section
*find_pc_section (CORE_ADDR pc
);
547 extern struct obj_section
*find_pc_sect_section (CORE_ADDR pc
,
550 extern int in_plt_section (CORE_ADDR
, char *);
552 extern int is_in_import_list (char *, struct objfile
*);
554 /* Keep a registry of per-objfile data-pointers required by other GDB
557 extern const struct objfile_data
*register_objfile_data (void);
558 extern void clear_objfile_data (struct objfile
*objfile
);
559 extern void set_objfile_data (struct objfile
*objfile
,
560 const struct objfile_data
*data
, void *value
);
561 extern void *objfile_data (struct objfile
*objfile
,
562 const struct objfile_data
*data
);
565 /* Traverse all object files. ALL_OBJFILES_SAFE works even if you delete
566 the objfile during the traversal. */
568 #define ALL_OBJFILES(obj) \
569 for ((obj) = object_files; (obj) != NULL; (obj) = (obj)->next)
571 #define ALL_OBJFILES_SAFE(obj,nxt) \
572 for ((obj) = object_files; \
573 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
576 /* Traverse all symtabs in one objfile. */
578 #define ALL_OBJFILE_SYMTABS(objfile, s) \
579 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
581 /* Traverse all psymtabs in one objfile. */
583 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
584 for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
586 /* Traverse all minimal symbols in one objfile. */
588 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
589 for ((m) = (objfile) -> msymbols; DEPRECATED_SYMBOL_NAME(m) != NULL; (m)++)
591 /* Traverse all symtabs in all objfiles. */
593 #define ALL_SYMTABS(objfile, s) \
594 ALL_OBJFILES (objfile) \
595 ALL_OBJFILE_SYMTABS (objfile, s)
597 /* Traverse all psymtabs in all objfiles. */
599 #define ALL_PSYMTABS(objfile, p) \
600 ALL_OBJFILES (objfile) \
601 ALL_OBJFILE_PSYMTABS (objfile, p)
603 /* Traverse all minimal symbols in all objfiles. */
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++)
612 #define ALL_OBJSECTIONS(objfile, osect) \
613 ALL_OBJFILES (objfile) \
614 ALL_OBJFILE_OSECTIONS (objfile, osect)
616 #define SECT_OFF_DATA(objfile) \
617 ((objfile->sect_index_data == -1) \
618 ? (internal_error (__FILE__, __LINE__, "sect_index_data not initialized"), -1) \
619 : objfile->sect_index_data)
621 #define SECT_OFF_RODATA(objfile) \
622 ((objfile->sect_index_rodata == -1) \
623 ? (internal_error (__FILE__, __LINE__, "sect_index_rodata not initialized"), -1) \
624 : objfile->sect_index_rodata)
626 #define SECT_OFF_TEXT(objfile) \
627 ((objfile->sect_index_text == -1) \
628 ? (internal_error (__FILE__, __LINE__, "sect_index_text not initialized"), -1) \
629 : objfile->sect_index_text)
631 /* Sometimes the .bss section is missing from the objfile, so we don't
632 want to die here. Let the users of SECT_OFF_BSS deal with an
633 uninitialized section index. */
634 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
636 #endif /* !defined (OBJFILES_H) */