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 is to use the
48 recorded entry point to set the variables
49 deprecated_entry_file_lowpc and deprecated_entry_file_highpc from
50 the debugging information, where these values are the starting
51 address (inclusive) and ending address (exclusive) of the
52 instruction space in the executable which correspond to the
53 "startup file", I.E. crt0.o in most cases. This file is assumed to
54 be a startup file and frames with pc's inside it are treated as
55 nonexistent. Setting these variables is necessary so that
56 backtraces do not fly off the bottom of the stack.
58 NOTE: cagney/2003-09-09: It turns out that this "traditional"
59 method doesn't work. Corinna writes: ``It turns out that the call
60 to deprecated_inside_entry_file destroys a meaningful backtrace
61 under some conditions. E. g. the backtrace tests in the asm-source
62 testcase are broken for some targets. In this test the functions
63 are all implemented as part of one file and the testcase is not
64 necessarily linked with a start file (depending on the target).
65 What happens is, that the first frame is printed normaly and
66 following frames are treated as being inside the enttry file then.
67 This way, only the #0 frame is printed in the backtrace output.''
68 Ref "frame.c" "NOTE: vinschen/2003-04-01".
70 Gdb also supports an alternate method to avoid running off the bottom
73 There are two frames that are "special", the frame for the function
74 containing the process entry point, since it has no predecessor frame,
75 and the frame for the function containing the user code entry point
76 (the main() function), since all the predecessor frames are for the
77 process startup code. Since we have no guarantee that the linked
78 in startup modules have any debugging information that gdb can use,
79 we need to avoid following frame pointers back into frames that might
80 have been built in the startup code, as we might get hopelessly
81 confused. However, we almost always have debugging information
84 These variables are used to save the range of PC values which are
85 valid within the main() function and within the function containing
86 the process entry point. If we always consider the frame for
87 main() as the outermost frame when debugging user code, and the
88 frame for the process entry point function as the outermost frame
89 when debugging startup code, then all we have to do is have
90 DEPRECATED_FRAME_CHAIN_VALID return false whenever a frame's
91 current PC is within the range specified by these variables. In
92 essence, we set "ceilings" in the frame chain beyond which we will
93 not proceed when following the frame chain back up the stack.
95 A nice side effect is that we can still debug startup code without
96 running off the end of the frame chain, assuming that we have usable
97 debugging information in the startup modules, and if we choose to not
98 use the block at main, or can't find it for some reason, everything
99 still works as before. And if we have no startup code debugging
100 information but we do have usable information for main(), backtraces
101 from user code don't go wandering off into the startup code. */
106 /* The value we should use for this objects entry point.
107 The illegal/unknown value needs to be something other than 0, ~0
108 for instance, which is much less likely than 0. */
110 CORE_ADDR entry_point;
112 #define INVALID_ENTRY_POINT (~0) /* ~0 will not be in any file, we hope. */
114 /* Start (inclusive) and end (exclusive) of function containing the
117 CORE_ADDR entry_func_lowpc;
118 CORE_ADDR entry_func_highpc;
120 /* Start (inclusive) and end (exclusive) of object file containing the
123 CORE_ADDR deprecated_entry_file_lowpc;
124 CORE_ADDR deprecated_entry_file_highpc;
126 /* Start (inclusive) and end (exclusive) of the user code main() function. */
128 CORE_ADDR main_func_lowpc;
129 CORE_ADDR main_func_highpc;
131 /* Use these values when any of the above ranges is invalid. */
133 /* We use these values because it guarantees that there is no number that is
134 both >= LOWPC && < HIGHPC. It is also highly unlikely that 3 is a valid
135 module or function start address (as opposed to 0). */
137 #define INVALID_ENTRY_LOWPC (3)
138 #define INVALID_ENTRY_HIGHPC (1)
142 /* Sections in an objfile.
144 It is strange that we have both this notion of "sections"
145 and the one used by section_offsets. Section as used
146 here, (currently at least) means a BFD section, and the sections
147 are set up from the BFD sections in allocate_objfile.
149 The sections in section_offsets have their meaning determined by
150 the symbol format, and they are set up by the sym_offsets function
151 for that symbol file format.
153 I'm not sure this could or should be changed, however. */
157 CORE_ADDR addr; /* lowest address in section */
158 CORE_ADDR endaddr; /* 1+highest address in section */
160 /* This field is being used for nefarious purposes by syms_from_objfile.
161 It is said to be redundant with section_offsets; it's not really being
162 used that way, however, it's some sort of hack I don't understand
163 and am not going to try to eliminate (yet, anyway). FIXME.
165 It was documented as "offset between (end)addr and actual memory
166 addresses", but that's not true; addr & endaddr are actual memory
170 struct bfd_section *the_bfd_section; /* BFD section pointer */
172 /* Objfile this section is part of. */
173 struct objfile *objfile;
175 /* True if this "overlay section" is mapped into an "overlay region". */
179 /* An import entry contains information about a symbol that
180 is used in this objfile but not defined in it, and so needs
181 to be imported from some other objfile */
182 /* Currently we just store the name; no attributes. 1997-08-05 */
183 typedef char *ImportEntry;
186 /* An export entry contains information about a symbol that
187 is defined in this objfile and available for use in other
191 char *name; /* name of exported symbol */
192 int address; /* offset subject to relocation */
193 /* Currently no other attributes 1997-08-05 */
198 /* The "objstats" structure provides a place for gdb to record some
199 interesting information about its internal state at runtime, on a
200 per objfile basis, such as information about the number of symbols
201 read, size of string table (if any), etc. */
205 int n_minsyms; /* Number of minimal symbols read */
206 int n_psyms; /* Number of partial symbols read */
207 int n_syms; /* Number of full symbols read */
208 int n_stabs; /* Number of ".stabs" read (if applicable) */
209 int n_types; /* Number of types */
210 int sz_strtab; /* Size of stringtable, (if applicable) */
213 #define OBJSTAT(objfile, expr) (objfile -> stats.expr)
214 #define OBJSTATS struct objstats stats
215 extern void print_objfile_statistics (void);
216 extern void print_symbol_bcache_statistics (void);
218 /* Number of entries in the minimal symbol hash table. */
219 #define MINIMAL_SYMBOL_HASH_SIZE 2039
221 /* Master structure for keeping track of each file from which
222 gdb reads symbols. There are several ways these get allocated: 1.
223 The main symbol file, symfile_objfile, set by the symbol-file command,
224 2. Additional symbol files added by the add-symbol-file command,
225 3. Shared library objfiles, added by ADD_SOLIB, 4. symbol files
226 for modules that were loaded when GDB attached to a remote system
227 (see remote-vx.c). */
232 /* All struct objfile's are chained together by their next pointers.
233 The global variable "object_files" points to the first link in this
236 FIXME: There is a problem here if the objfile is reusable, and if
237 multiple users are to be supported. The problem is that the objfile
238 list is linked through a member of the objfile struct itself, which
239 is only valid for one gdb process. The list implementation needs to
240 be changed to something like:
242 struct list {struct list *next; struct objfile *objfile};
244 where the list structure is completely maintained separately within
247 struct objfile *next;
249 /* The object file's name, tilde-expanded and absolute.
250 Malloc'd; free it if you free this struct. */
254 /* Some flag bits for this objfile. */
256 unsigned short flags;
258 /* Each objfile points to a linked list of symtabs derived from this file,
259 one symtab structure for each compilation unit (source file). Each link
260 in the symtab list contains a backpointer to this objfile. */
262 struct symtab *symtabs;
264 /* Each objfile points to a linked list of partial symtabs derived from
265 this file, one partial symtab structure for each compilation unit
268 struct partial_symtab *psymtabs;
270 /* List of freed partial symtabs, available for re-use */
272 struct partial_symtab *free_psymtabs;
274 /* The object file's BFD. Can be null if the objfile contains only
275 minimal symbols, e.g. the run time common symbols for SunOS4. */
279 /* The modification timestamp of the object file, as of the last time
280 we read its symbols. */
284 /* Obstack to hold objects that should be freed when we load a new symbol
285 table from this object file. */
287 struct obstack objfile_obstack;
289 /* A byte cache where we can stash arbitrary "chunks" of bytes that
292 struct bcache *psymbol_cache; /* Byte cache for partial syms */
293 struct bcache *macro_cache; /* Byte cache for macros */
295 /* Hash table for mapping symbol names to demangled names. Each
296 entry in the hash table is actually two consecutive strings,
297 both null-terminated; the first one is a mangled or linkage
298 name, and the second is the demangled name or just a zero byte
299 if the name doesn't demangle. */
300 struct htab *demangled_names_hash;
302 /* Vectors of all partial symbols read in from file. The actual data
303 is stored in the objfile_obstack. */
305 struct psymbol_allocation_list global_psymbols;
306 struct psymbol_allocation_list static_psymbols;
308 /* Each file contains a pointer to an array of minimal symbols for all
309 global symbols that are defined within the file. The array is terminated
310 by a "null symbol", one that has a NULL pointer for the name and a zero
311 value for the address. This makes it easy to walk through the array
312 when passed a pointer to somewhere in the middle of it. There is also
313 a count of the number of symbols, which does not include the terminating
314 null symbol. The array itself, as well as all the data that it points
315 to, should be allocated on the objfile_obstack for this file. */
317 struct minimal_symbol *msymbols;
318 int minimal_symbol_count;
320 /* This is a hash table used to index the minimal symbols by name. */
322 struct minimal_symbol *msymbol_hash[MINIMAL_SYMBOL_HASH_SIZE];
324 /* This hash table is used to index the minimal symbols by their
327 struct minimal_symbol *msymbol_demangled_hash[MINIMAL_SYMBOL_HASH_SIZE];
329 /* For object file formats which don't specify fundamental types, gdb
330 can create such types. For now, it maintains a vector of pointers
331 to these internally created fundamental types on a per objfile basis,
332 however it really should ultimately keep them on a per-compilation-unit
333 basis, to account for linkage-units that consist of a number of
334 compilation units that may have different fundamental types, such as
335 linking C modules with ADA modules, or linking C modules that are
336 compiled with 32-bit ints with C modules that are compiled with 64-bit
337 ints (not inherently evil with a smarter linker). */
339 struct type **fundamental_types;
341 /* The mmalloc() malloc-descriptor for this objfile if we are using
342 the memory mapped malloc() package to manage storage for this objfile's
343 data. NULL if we are not. */
347 /* The file descriptor that was used to obtain the mmalloc descriptor
348 for this objfile. If we call mmalloc_detach with the malloc descriptor
349 we should then close this file descriptor. */
353 /* Structure which keeps track of functions that manipulate objfile's
354 of the same type as this objfile. I.E. the function to read partial
355 symbols for example. Note that this structure is in statically
356 allocated memory, and is shared by all objfiles that use the
357 object module reader of this type. */
361 /* The per-objfile information about the entry point, the scope (file/func)
362 containing the entry point, and the scope of the user's main() func. */
364 struct entry_info ei;
366 /* Information about stabs. Will be filled in with a dbx_symfile_info
367 struct by those readers that need it. */
369 struct dbx_symfile_info *sym_stab_info;
371 /* Hook for information for use by the symbol reader (currently used
372 for information shared by sym_init and sym_read). It is
373 typically a pointer to malloc'd memory. The symbol reader's finish
374 function is responsible for freeing the memory thusly allocated. */
378 /* Hook for target-architecture-specific information. This must
379 point to memory allocated on one of the obstacks in this objfile,
380 so that it gets freed automatically when reading a new object
385 /* Per objfile data-pointers required by other GDB modules. */
386 /* FIXME: kettenis/20030711: This mechanism could replace
387 sym_stab_info, sym_private and obj_private entirely. */
392 /* Set of relocation offsets to apply to each section.
393 Currently on the objfile_obstack (which makes no sense, but I'm
394 not sure it's harming anything).
396 These offsets indicate that all symbols (including partial and
397 minimal symbols) which have been read have been relocated by this
398 much. Symbols which are yet to be read need to be relocated by
401 struct section_offsets *section_offsets;
404 /* Indexes in the section_offsets array. These are initialized by the
405 *_symfile_offsets() family of functions (som_symfile_offsets,
406 xcoff_symfile_offsets, default_symfile_offsets). In theory they
407 should correspond to the section indexes used by bfd for the
408 current objfile. The exception to this for the time being is the
414 int sect_index_rodata;
416 /* These pointers are used to locate the section table, which
417 among other things, is used to map pc addresses into sections.
418 SECTIONS points to the first entry in the table, and
419 SECTIONS_END points to the first location past the last entry
420 in the table. Currently the table is stored on the
421 objfile_obstack (which makes no sense, but I'm not sure it's
422 harming anything). */
425 *sections, *sections_end;
427 /* Imported symbols */
428 /* FIXME: ezannoni 2004-02-10: This is just SOM (HP) specific (see
429 somread.c). It should not pollute generic objfiles. */
430 ImportEntry *import_list;
431 int import_list_size;
433 /* Exported symbols */
434 /* FIXME: ezannoni 2004-02-10: This is just SOM (HP) specific (see
435 somread.c). It should not pollute generic objfiles. */
436 ExportEntry *export_list;
437 int export_list_size;
439 /* Link to objfile that contains the debug symbols for this one.
440 One is loaded if this file has an debug link to an existing
441 debug file with the right checksum */
442 struct objfile *separate_debug_objfile;
444 /* If this is a separate debug object, this is used as a link to the
445 actual executable objfile. */
446 struct objfile *separate_debug_objfile_backlink;
448 /* Place to stash various statistics about this objfile */
451 /* A symtab that the C++ code uses to stash special symbols
452 associated to namespaces. */
454 /* FIXME/carlton-2003-06-27: Delete this in a few years once
455 "possible namespace symbols" go away. */
456 struct symtab *cp_namespace_symtab;
459 /* Defines for the objfile flag word. */
461 /* When using mapped/remapped predigested gdb symbol information, we need
462 a flag that indicates that we have previously done an initial symbol
463 table read from this particular objfile. We can't just look for the
464 absence of any of the three symbol tables (msymbols, psymtab, symtab)
465 because if the file has no symbols for example, none of these will
468 #define OBJF_SYMS (1 << 1) /* Have tried to read symbols */
470 /* When an object file has its functions reordered (currently Irix-5.2
471 shared libraries exhibit this behaviour), we will need an expensive
472 algorithm to locate a partial symtab or symtab via an address.
473 To avoid this penalty for normal object files, we use this flag,
474 whose setting is determined upon symbol table read in. */
476 #define OBJF_REORDERED (1 << 2) /* Functions are reordered */
478 /* Distinguish between an objfile for a shared library and a "vanilla"
479 objfile. (If not set, the objfile may still actually be a solib.
480 This can happen if the user created the objfile by using the
481 add-symbol-file command. GDB doesn't in that situation actually
482 check whether the file is a solib. Rather, the target's
483 implementation of the solib interface is responsible for setting
484 this flag when noticing solibs used by an inferior.) */
486 #define OBJF_SHARED (1 << 3) /* From a shared library */
488 /* User requested that this objfile be read in it's entirety. */
490 #define OBJF_READNOW (1 << 4) /* Immediate full read */
492 /* This objfile was created because the user explicitly caused it
493 (e.g., used the add-symbol-file command). This bit offers a way
494 for run_command to remove old objfile entries which are no longer
495 valid (i.e., are associated with an old inferior), but to preserve
496 ones that the user explicitly loaded via the add-symbol-file
499 #define OBJF_USERLOADED (1 << 5) /* User loaded */
501 /* The object file that the main symbol table was loaded from (e.g. the
502 argument to the "symbol-file" or "file" command). */
504 extern struct objfile *symfile_objfile;
506 /* The object file that contains the runtime common minimal symbols
507 for SunOS4. Note that this objfile has no associated BFD. */
509 extern struct objfile *rt_common_objfile;
511 /* When we need to allocate a new type, we need to know which objfile_obstack
512 to allocate the type on, since there is one for each objfile. The places
513 where types are allocated are deeply buried in function call hierarchies
514 which know nothing about objfiles, so rather than trying to pass a
515 particular objfile down to them, we just do an end run around them and
516 set current_objfile to be whatever objfile we expect to be using at the
517 time types are being allocated. For instance, when we start reading
518 symbols for a particular objfile, we set current_objfile to point to that
519 objfile, and when we are done, we set it back to NULL, to ensure that we
520 never put a type someplace other than where we are expecting to put it.
521 FIXME: Maybe we should review the entire type handling system and
522 see if there is a better way to avoid this problem. */
524 extern struct objfile *current_objfile;
526 /* All known objfiles are kept in a linked list. This points to the
527 root of this list. */
529 extern struct objfile *object_files;
531 /* Declarations for functions defined in objfiles.c */
533 extern struct objfile *allocate_objfile (bfd *, int);
535 extern int build_objfile_section_table (struct objfile *);
537 extern void terminate_minimal_symbol_table (struct objfile *objfile);
539 extern void put_objfile_before (struct objfile *, struct objfile *);
541 extern void objfile_to_front (struct objfile *);
543 extern void unlink_objfile (struct objfile *);
545 extern void free_objfile (struct objfile *);
547 extern struct cleanup *make_cleanup_free_objfile (struct objfile *);
549 extern void free_all_objfiles (void);
551 extern void objfile_relocate (struct objfile *, struct section_offsets *);
553 extern int have_partial_symbols (void);
555 extern int have_full_symbols (void);
557 /* This operation deletes all objfile entries that represent solibs that
558 weren't explicitly loaded by the user, via e.g., the add-symbol-file
561 extern void objfile_purge_solibs (void);
563 /* Functions for dealing with the minimal symbol table, really a misc
564 address<->symbol mapping for things we don't have debug symbols for. */
566 extern int have_minimal_symbols (void);
568 extern struct obj_section *find_pc_section (CORE_ADDR pc);
570 extern struct obj_section *find_pc_sect_section (CORE_ADDR pc,
573 extern int in_plt_section (CORE_ADDR, char *);
575 extern int is_in_import_list (char *, struct objfile *);
577 /* Keep a registry of per-objfile data-pointers required by other GDB
580 extern const struct objfile_data *register_objfile_data (void);
581 extern void clear_objfile_data (struct objfile *objfile);
582 extern void set_objfile_data (struct objfile *objfile,
583 const struct objfile_data *data, void *value);
584 extern void *objfile_data (struct objfile *objfile,
585 const struct objfile_data *data);
588 /* Traverse all object files. ALL_OBJFILES_SAFE works even if you delete
589 the objfile during the traversal. */
591 #define ALL_OBJFILES(obj) \
592 for ((obj) = object_files; (obj) != NULL; (obj) = (obj)->next)
594 #define ALL_OBJFILES_SAFE(obj,nxt) \
595 for ((obj) = object_files; \
596 (obj) != NULL? ((nxt)=(obj)->next,1) :0; \
599 /* Traverse all symtabs in one objfile. */
601 #define ALL_OBJFILE_SYMTABS(objfile, s) \
602 for ((s) = (objfile) -> symtabs; (s) != NULL; (s) = (s) -> next)
604 /* Traverse all psymtabs in one objfile. */
606 #define ALL_OBJFILE_PSYMTABS(objfile, p) \
607 for ((p) = (objfile) -> psymtabs; (p) != NULL; (p) = (p) -> next)
609 /* Traverse all minimal symbols in one objfile. */
611 #define ALL_OBJFILE_MSYMBOLS(objfile, m) \
612 for ((m) = (objfile) -> msymbols; DEPRECATED_SYMBOL_NAME(m) != NULL; (m)++)
614 /* Traverse all symtabs in all objfiles. */
616 #define ALL_SYMTABS(objfile, s) \
617 ALL_OBJFILES (objfile) \
618 ALL_OBJFILE_SYMTABS (objfile, s)
620 /* Traverse all psymtabs in all objfiles. */
622 #define ALL_PSYMTABS(objfile, p) \
623 ALL_OBJFILES (objfile) \
624 ALL_OBJFILE_PSYMTABS (objfile, p)
626 /* Traverse all minimal symbols in all objfiles. */
628 #define ALL_MSYMBOLS(objfile, m) \
629 ALL_OBJFILES (objfile) \
630 ALL_OBJFILE_MSYMBOLS (objfile, m)
632 #define ALL_OBJFILE_OSECTIONS(objfile, osect) \
633 for (osect = objfile->sections; osect < objfile->sections_end; osect++)
635 #define ALL_OBJSECTIONS(objfile, osect) \
636 ALL_OBJFILES (objfile) \
637 ALL_OBJFILE_OSECTIONS (objfile, osect)
639 #define SECT_OFF_DATA(objfile) \
640 ((objfile->sect_index_data == -1) \
641 ? (internal_error (__FILE__, __LINE__, "sect_index_data not initialized"), -1) \
642 : objfile->sect_index_data)
644 #define SECT_OFF_RODATA(objfile) \
645 ((objfile->sect_index_rodata == -1) \
646 ? (internal_error (__FILE__, __LINE__, "sect_index_rodata not initialized"), -1) \
647 : objfile->sect_index_rodata)
649 #define SECT_OFF_TEXT(objfile) \
650 ((objfile->sect_index_text == -1) \
651 ? (internal_error (__FILE__, __LINE__, "sect_index_text not initialized"), -1) \
652 : objfile->sect_index_text)
654 /* Sometimes the .bss section is missing from the objfile, so we don't
655 want to die here. Let the users of SECT_OFF_BSS deal with an
656 uninitialized section index. */
657 #define SECT_OFF_BSS(objfile) (objfile)->sect_index_bss
659 #endif /* !defined (OBJFILES_H) */