1 /* GDB routines for manipulating objfiles.
2 Copyright 1992 Free Software Foundation, Inc.
3 Contributed by Cygnus Support, using pieces from other GDB modules.
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 2 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, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* This file contains support routines for creating, manipulating, and
22 destroying objfile structures. */
25 #include "bfd.h" /* Binary File Description */
29 #include "gdb-stabs.h"
32 #include <sys/types.h>
37 /* Prototypes for local functions */
39 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
42 open_existing_mapped_file
PARAMS ((char *, long, int));
45 open_mapped_file
PARAMS ((char *filename
, long mtime
, int mapped
));
48 map_to_address
PARAMS ((void));
50 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
52 /* Message to be printed before the error message, when an error occurs. */
54 extern char *error_pre_print
;
56 /* Externally visible variables that are owned by this module.
57 See declarations in objfile.h for more info. */
59 struct objfile
*object_files
; /* Linked list of all objfiles */
60 struct objfile
*current_objfile
; /* For symbol file being read in */
61 struct objfile
*symfile_objfile
; /* Main symbol table loaded from */
63 int mapped_symbol_files
; /* Try to use mapped symbol files */
65 /* Locate all mappable sections of a BFD file.
66 objfile_p_char is a char * to get it through
67 bfd_map_over_sections; we cast it back to its proper type. */
70 add_to_objfile_sections (abfd
, asect
, objfile_p_char
)
75 struct objfile
*objfile
= (struct objfile
*) objfile_p_char
;
76 struct obj_section section
;
79 aflag
= bfd_get_section_flags (abfd
, asect
);
80 /* FIXME, we need to handle BSS segment here...it alloc's but doesn't load */
81 if (!(aflag
& SEC_LOAD
))
83 if (0 == bfd_section_size (abfd
, asect
))
86 section
.objfile
= objfile
;
87 section
.sec_ptr
= asect
;
88 section
.addr
= bfd_section_vma (abfd
, asect
);
89 section
.endaddr
= section
.addr
+ bfd_section_size (abfd
, asect
);
90 obstack_grow (&objfile
->psymbol_obstack
, §ion
, sizeof(section
));
91 objfile
->sections_end
= (struct obj_section
*) (((unsigned long) objfile
->sections_end
) + 1);
94 /* Builds a section table for OBJFILE.
95 Returns 0 if OK, 1 on error. */
98 build_objfile_section_table (objfile
)
99 struct objfile
*objfile
;
101 if (objfile
->sections
)
104 objfile
->sections_end
= 0;
105 bfd_map_over_sections (objfile
->obfd
, add_to_objfile_sections
, (char *)objfile
);
106 objfile
->sections
= (struct obj_section
*)
107 obstack_finish (&objfile
->psymbol_obstack
);
108 objfile
->sections_end
= objfile
->sections
+ (unsigned long) objfile
->sections_end
;
112 /* Given a pointer to an initialized bfd (ABFD) and a flag that indicates
113 whether or not an objfile is to be mapped (MAPPED), allocate a new objfile
114 struct, fill it in as best we can, link it into the list of all known
115 objfiles, and return a pointer to the new objfile struct. */
118 allocate_objfile (abfd
, mapped
)
122 struct objfile
*objfile
= NULL
;
124 mapped
|= mapped_symbol_files
;
126 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
129 /* If we can support mapped symbol files, try to open/reopen the
130 mapped file that corresponds to the file from which we wish to
131 read symbols. If the objfile is to be mapped, we must malloc
132 the structure itself using the mmap version, and arrange that
133 all memory allocation for the objfile uses the mmap routines.
134 If we are reusing an existing mapped file, from which we get
135 our objfile pointer, we have to make sure that we update the
136 pointers to the alloc/free functions in the obstack, in case
137 these functions have moved within the current gdb. */
141 fd
= open_mapped_file (bfd_get_filename (abfd
), bfd_get_mtime (abfd
),
148 if (((mapto
= map_to_address ()) == 0) ||
149 ((md
= mmalloc_attach (fd
, (PTR
) mapto
)) == NULL
))
153 else if ((objfile
= (struct objfile
*) mmalloc_getkey (md
, 0)) != NULL
)
155 /* Update memory corruption handler function addresses. */
158 objfile
-> mmfd
= fd
;
159 /* Update pointers to functions to *our* copies */
160 obstack_chunkfun (&objfile
-> psymbol_obstack
, xmmalloc
);
161 obstack_freefun (&objfile
-> psymbol_obstack
, mfree
);
162 obstack_chunkfun (&objfile
-> symbol_obstack
, xmmalloc
);
163 obstack_freefun (&objfile
-> symbol_obstack
, mfree
);
164 obstack_chunkfun (&objfile
-> type_obstack
, xmmalloc
);
165 obstack_freefun (&objfile
-> type_obstack
, mfree
);
166 /* If already in objfile list, unlink it. */
167 unlink_objfile (objfile
);
168 /* Forget things specific to a particular gdb, may have changed. */
169 objfile
-> sf
= NULL
;
174 /* Set up to detect internal memory corruption. MUST be
175 done before the first malloc. See comments in
176 init_malloc() and mmcheck(). */
180 objfile
= (struct objfile
*)
181 xmmalloc (md
, sizeof (struct objfile
));
182 memset (objfile
, 0, sizeof (struct objfile
));
184 objfile
-> mmfd
= fd
;
185 objfile
-> flags
|= OBJF_MAPPED
;
186 mmalloc_setkey (objfile
-> md
, 0, objfile
);
187 obstack_specify_allocation_with_arg (&objfile
-> psymbol_obstack
,
188 0, 0, xmmalloc
, mfree
,
190 obstack_specify_allocation_with_arg (&objfile
-> symbol_obstack
,
191 0, 0, xmmalloc
, mfree
,
193 obstack_specify_allocation_with_arg (&objfile
-> type_obstack
,
194 0, 0, xmmalloc
, mfree
,
199 if (mapped
&& (objfile
== NULL
))
201 warning ("symbol table for '%s' will not be mapped",
202 bfd_get_filename (abfd
));
205 #else /* defined(NO_MMALLOC) || !defined(HAVE_MMAP) */
209 warning ("this version of gdb does not support mapped symbol tables.");
211 /* Turn off the global flag so we don't try to do mapped symbol tables
212 any more, which shuts up gdb unless the user specifically gives the
213 "mapped" keyword again. */
215 mapped_symbol_files
= 0;
218 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
220 /* If we don't support mapped symbol files, didn't ask for the file to be
221 mapped, or failed to open the mapped file for some reason, then revert
222 back to an unmapped objfile. */
226 objfile
= (struct objfile
*) xmalloc (sizeof (struct objfile
));
227 memset (objfile
, 0, sizeof (struct objfile
));
228 objfile
-> md
= NULL
;
229 obstack_specify_allocation (&objfile
-> psymbol_obstack
, 0, 0, xmalloc
,
231 obstack_specify_allocation (&objfile
-> symbol_obstack
, 0, 0, xmalloc
,
233 obstack_specify_allocation (&objfile
-> type_obstack
, 0, 0, xmalloc
,
237 /* Update the per-objfile information that comes from the bfd, ensuring
238 that any data that is reference is saved in the per-objfile data
241 objfile
-> obfd
= abfd
;
242 if (objfile
-> name
!= NULL
)
244 mfree (objfile
-> md
, objfile
-> name
);
246 objfile
-> name
= mstrsave (objfile
-> md
, bfd_get_filename (abfd
));
247 objfile
-> mtime
= bfd_get_mtime (abfd
);
249 /* Build section table. */
251 if (build_objfile_section_table (objfile
))
253 error ("Can't find the file sections in `%s': %s",
254 objfile
-> name
, bfd_errmsg (bfd_error
));
257 /* Push this file onto the head of the linked list of other such files. */
259 objfile
-> next
= object_files
;
260 object_files
= objfile
;
265 /* Unlink OBJFILE from the list of known objfiles, if it is found in the
268 It is not a bug, or error, to call this function if OBJFILE is not known
269 to be in the current list. This is done in the case of mapped objfiles,
270 for example, just to ensure that the mapped objfile doesn't appear twice
271 in the list. Since the list is threaded, linking in a mapped objfile
272 twice would create a circular list.
274 If OBJFILE turns out to be in the list, we zap it's NEXT pointer after
275 unlinking it, just to ensure that we have completely severed any linkages
276 between the OBJFILE and the list. */
279 unlink_objfile (objfile
)
280 struct objfile
*objfile
;
282 struct objfile
** objpp
;
284 for (objpp
= &object_files
; *objpp
!= NULL
; objpp
= &((*objpp
) -> next
))
286 if (*objpp
== objfile
)
288 *objpp
= (*objpp
) -> next
;
289 objfile
-> next
= NULL
;
296 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
297 that as much as possible is allocated on the symbol_obstack and
298 psymbol_obstack, so that the memory can be efficiently freed.
300 Things which we do NOT free because they are not in malloc'd memory
301 or not in memory specific to the objfile include:
305 FIXME: If the objfile is using reusable symbol information (via mmalloc),
306 then we need to take into account the fact that more than one process
307 may be using the symbol information at the same time (when mmalloc is
308 extended to support cooperative locking). When more than one process
309 is using the mapped symbol info, we need to be more careful about when
310 we free objects in the reusable area. */
313 free_objfile (objfile
)
314 struct objfile
*objfile
;
316 /* First do any symbol file specific actions required when we are
317 finished with a particular symbol file. Note that if the objfile
318 is using reusable symbol information (via mmalloc) then each of
319 these routines is responsible for doing the correct thing, either
320 freeing things which are valid only during this particular gdb
321 execution, or leaving them to be reused during the next one. */
323 if (objfile
-> sf
!= NULL
)
325 (*objfile
-> sf
-> sym_finish
) (objfile
);
328 /* We always close the bfd. */
330 if (objfile
-> obfd
!= NULL
)
332 char *name
= bfd_get_filename (objfile
->obfd
);
333 bfd_close (objfile
-> obfd
);
337 /* Remove it from the chain of all objfiles. */
339 unlink_objfile (objfile
);
341 /* Before the symbol table code was redone to make it easier to
342 selectively load and remove information particular to a specific
343 linkage unit, gdb used to do these things whenever the monolithic
344 symbol table was blown away. How much still needs to be done
345 is unknown, but we play it safe for now and keep each action until
346 it is shown to be no longer needed. */
348 #if defined (CLEAR_SOLIB)
350 /* CLEAR_SOLIB closes the bfd's for any shared libraries. But
351 the to_sections for a core file might refer to those bfd's. So
352 detach any core file. */
354 struct target_ops
*t
= find_core_target ();
356 (t
->to_detach
) (NULL
, 0);
359 clear_pc_function_cache ();
361 /* The last thing we do is free the objfile struct itself for the
362 non-reusable case, or detach from the mapped file for the reusable
363 case. Note that the mmalloc_detach or the mfree is the last thing
364 we can do with this objfile. */
366 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
368 if (objfile
-> flags
& OBJF_MAPPED
)
370 /* Remember the fd so we can close it. We can't close it before
371 doing the detach, and after the detach the objfile is gone. */
374 mmfd
= objfile
-> mmfd
;
375 mmalloc_detach (objfile
-> md
);
380 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
382 /* If we still have an objfile, then either we don't support reusable
383 objfiles or this one was not reusable. So free it normally. */
387 if (objfile
-> name
!= NULL
)
389 mfree (objfile
-> md
, objfile
-> name
);
391 if (objfile
->global_psymbols
.list
)
392 mfree (objfile
->md
, objfile
->global_psymbols
.list
);
393 if (objfile
->static_psymbols
.list
)
394 mfree (objfile
->md
, objfile
->static_psymbols
.list
);
395 /* Free the obstacks for non-reusable objfiles */
396 obstack_free (&objfile
-> psymbol_obstack
, 0);
397 obstack_free (&objfile
-> symbol_obstack
, 0);
398 obstack_free (&objfile
-> type_obstack
, 0);
399 mfree (objfile
-> md
, objfile
);
405 /* Free all the object files at once and clean up their users. */
410 struct objfile
*objfile
, *temp
;
412 ALL_OBJFILES_SAFE (objfile
, temp
)
414 free_objfile (objfile
);
416 clear_symtab_users ();
419 /* Relocate OBJFILE to NEW_OFFSETS. There should be OBJFILE->NUM_SECTIONS
420 entries in new_offsets. */
422 objfile_relocate (objfile
, new_offsets
)
423 struct objfile
*objfile
;
424 struct section_offsets
*new_offsets
;
426 struct section_offsets
*delta
= (struct section_offsets
*) alloca
427 (sizeof (struct section_offsets
)
428 + objfile
->num_sections
* sizeof (delta
->offsets
));
432 int something_changed
= 0;
433 for (i
= 0; i
< objfile
->num_sections
; ++i
)
435 ANOFFSET (delta
, i
) =
436 ANOFFSET (new_offsets
, i
) - ANOFFSET (objfile
->section_offsets
, i
);
437 if (ANOFFSET (delta
, i
) != 0)
438 something_changed
= 1;
440 if (!something_changed
)
444 /* OK, get all the symtabs. */
448 for (s
= objfile
->symtabs
; s
; s
= s
->next
)
451 struct blockvector
*bv
;
454 /* First the line table. */
458 for (i
= 0; i
< l
->nitems
; ++i
)
459 l
->item
[i
].pc
+= ANOFFSET (delta
, s
->block_line_section
);
462 /* Don't relocate a shared blockvector more than once. */
466 bv
= BLOCKVECTOR (s
);
467 for (i
= 0; i
< BLOCKVECTOR_NBLOCKS (bv
); ++i
)
472 b
= BLOCKVECTOR_BLOCK (bv
, i
);
473 BLOCK_START (b
) += ANOFFSET (delta
, s
->block_line_section
);
474 BLOCK_END (b
) += ANOFFSET (delta
, s
->block_line_section
);
476 for (j
= 0; j
< BLOCK_NSYMS (b
); ++j
)
478 struct symbol
*sym
= BLOCK_SYM (b
, j
);
479 /* The RS6000 code from which this was taken skipped
480 any symbols in STRUCT_NAMESPACE or UNDEF_NAMESPACE.
481 But I'm leaving out that test, on the theory that
482 they can't possibly pass the tests below. */
483 if ((SYMBOL_CLASS (sym
) == LOC_LABEL
484 || SYMBOL_CLASS (sym
) == LOC_STATIC
)
485 && SYMBOL_SECTION (sym
) >= 0)
487 SYMBOL_VALUE_ADDRESS (sym
) +=
488 ANOFFSET (delta
, SYMBOL_SECTION (sym
));
496 struct partial_symtab
*p
;
498 ALL_OBJFILE_PSYMTABS (objfile
, p
)
500 /* FIXME: specific to symbol readers which use gdb-stabs.h.
501 We can only get away with it since objfile_relocate is only
502 used on XCOFF, which lacks psymtabs, and for gdb-stabs.h
504 p
->textlow
+= ANOFFSET (delta
, SECT_OFF_TEXT
);
505 p
->texthigh
+= ANOFFSET (delta
, SECT_OFF_TEXT
);
510 struct partial_symbol
*psym
;
512 for (psym
= objfile
->global_psymbols
.list
;
513 psym
< objfile
->global_psymbols
.next
;
515 if (SYMBOL_SECTION (psym
) >= 0)
516 SYMBOL_VALUE_ADDRESS (psym
) += ANOFFSET (delta
, SYMBOL_SECTION (psym
));
517 for (psym
= objfile
->static_psymbols
.list
;
518 psym
< objfile
->static_psymbols
.next
;
520 if (SYMBOL_SECTION (psym
) >= 0)
521 SYMBOL_VALUE_ADDRESS (psym
) += ANOFFSET (delta
, SYMBOL_SECTION (psym
));
525 struct minimal_symbol
*msym
;
526 ALL_OBJFILE_MSYMBOLS (objfile
, msym
)
527 if (SYMBOL_SECTION (msym
) >= 0)
528 SYMBOL_VALUE_ADDRESS (msym
) += ANOFFSET (delta
, SYMBOL_SECTION (msym
));
533 for (i
= 0; i
< objfile
->num_sections
; ++i
)
534 ANOFFSET (objfile
->section_offsets
, i
) = ANOFFSET (new_offsets
, i
);
538 /* Many places in gdb want to test just to see if we have any partial
539 symbols available. This function returns zero if none are currently
540 available, nonzero otherwise. */
543 have_partial_symbols ()
549 if (ofp
-> psymtabs
!= NULL
)
557 /* Many places in gdb want to test just to see if we have any full
558 symbols available. This function returns zero if none are currently
559 available, nonzero otherwise. */
568 if (ofp
-> symtabs
!= NULL
)
576 /* Many places in gdb want to test just to see if we have any minimal
577 symbols available. This function returns zero if none are currently
578 available, nonzero otherwise. */
581 have_minimal_symbols ()
587 if (ofp
-> msymbols
!= NULL
)
595 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
597 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
598 of the corresponding symbol file in MTIME, try to open an existing file
599 with the name SYMSFILENAME and verify it is more recent than the base
600 file by checking it's timestamp against MTIME.
602 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
604 If SYMSFILENAME does exist, but is out of date, we check to see if the
605 user has specified creation of a mapped file. If so, we don't issue
606 any warning message because we will be creating a new mapped file anyway,
607 overwriting the old one. If not, then we issue a warning message so that
608 the user will know why we aren't using this existing mapped symbol file.
609 In either case, we return -1.
611 If SYMSFILENAME does exist and is not out of date, but can't be opened for
612 some reason, then prints an appropriate system error message and returns -1.
614 Otherwise, returns the open file descriptor. */
617 open_existing_mapped_file (symsfilename
, mtime
, mapped
)
625 if (stat (symsfilename
, &sbuf
) == 0)
627 if (sbuf
.st_mtime
< mtime
)
631 warning ("mapped symbol file `%s' is out of date, ignored it",
635 else if ((fd
= open (symsfilename
, O_RDWR
)) < 0)
639 printf (error_pre_print
);
641 print_sys_errmsg (symsfilename
, errno
);
647 /* Look for a mapped symbol file that corresponds to FILENAME and is more
648 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
649 use a mapped symbol file for this file, so create a new one if one does
652 If found, then return an open file descriptor for the file, otherwise
655 This routine is responsible for implementing the policy that generates
656 the name of the mapped symbol file from the name of a file containing
657 symbols that gdb would like to read. Currently this policy is to append
658 ".syms" to the name of the file.
660 This routine is also responsible for implementing the policy that
661 determines where the mapped symbol file is found (the search path).
662 This policy is that when reading an existing mapped file, a file of
663 the correct name in the current directory takes precedence over a
664 file of the correct name in the same directory as the symbol file.
665 When creating a new mapped file, it is always created in the current
666 directory. This helps to minimize the chances of a user unknowingly
667 creating big mapped files in places like /bin and /usr/local/bin, and
668 allows a local copy to override a manually installed global copy (in
669 /bin for example). */
672 open_mapped_file (filename
, mtime
, mapped
)
680 /* First try to open an existing file in the current directory, and
681 then try the directory where the symbol file is located. */
683 symsfilename
= concat ("./", basename (filename
), ".syms", (char *) NULL
);
684 if ((fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
)) < 0)
687 symsfilename
= concat (filename
, ".syms", (char *) NULL
);
688 fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
);
691 /* If we don't have an open file by now, then either the file does not
692 already exist, or the base file has changed since it was created. In
693 either case, if the user has specified use of a mapped file, then
694 create a new mapped file, truncating any existing one. If we can't
695 create one, print a system error message saying why we can't.
697 By default the file is rw for everyone, with the user's umask taking
698 care of turning off the permissions the user wants off. */
700 if ((fd
< 0) && mapped
)
703 symsfilename
= concat ("./", basename (filename
), ".syms",
705 if ((fd
= open (symsfilename
, O_RDWR
| O_CREAT
| O_TRUNC
, 0666)) < 0)
709 printf (error_pre_print
);
711 print_sys_errmsg (symsfilename
, errno
);
719 /* Return the base address at which we would like the next objfile's
720 mapped data to start.
722 For now, we use the kludge that the configuration specifies a base
723 address to which it is safe to map the first mmalloc heap, and an
724 increment to add to this address for each successive heap. There are
725 a lot of issues to deal with here to make this work reasonably, including:
727 Avoid memory collisions with existing mapped address spaces
729 Reclaim address spaces when their mmalloc heaps are unmapped
731 When mmalloc heaps are shared between processes they have to be
732 mapped at the same addresses in each
734 Once created, a mmalloc heap that is to be mapped back in must be
735 mapped at the original address. I.E. each objfile will expect to
736 be remapped at it's original address. This becomes a problem if
737 the desired address is already in use.
748 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
750 static CORE_ADDR next
= MMAP_BASE_ADDRESS
;
751 CORE_ADDR mapto
= next
;
753 next
+= MMAP_INCREMENT
;
764 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
766 /* Returns a section whose range includes PC or NULL if none found. */
772 struct obj_section
*s
;
773 struct objfile
*objfile
;
775 ALL_OBJFILES (objfile
)
776 for (s
= objfile
->sections
; s
< objfile
->sections_end
; ++s
)