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 */
30 #include <sys/types.h>
35 /* Prototypes for local functions */
37 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
40 open_existing_mapped_file
PARAMS ((char *, long, int));
43 open_mapped_file
PARAMS ((char *filename
, long mtime
, int mapped
));
46 map_to_address
PARAMS ((void));
48 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
50 /* Message to be printed before the error message, when an error occurs. */
52 extern char *error_pre_print
;
54 /* Externally visible variables that are owned by this module.
55 See declarations in objfile.h for more info. */
57 struct objfile
*object_files
; /* Linked list of all objfiles */
58 struct objfile
*current_objfile
; /* For symbol file being read in */
59 struct objfile
*symfile_objfile
; /* Main symbol table loaded from */
61 int mapped_symbol_files
; /* Try to use mapped symbol files */
63 /* Locate all mappable sections of a BFD file.
64 objfile_p_char is a char * to get it through
65 bfd_map_over_sections; we cast it back to its proper type. */
68 add_to_objfile_sections (abfd
, asect
, objfile_p_char
)
73 struct objfile
*objfile
= (struct objfile
*) objfile_p_char
;
74 struct obj_section section
;
77 aflag
= bfd_get_section_flags (abfd
, asect
);
78 /* FIXME, we need to handle BSS segment here...it alloc's but doesn't load */
79 if (!(aflag
& SEC_LOAD
))
81 if (0 == bfd_section_size (abfd
, asect
))
84 section
.sec_ptr
= asect
;
85 section
.addr
= bfd_section_vma (abfd
, asect
);
86 section
.endaddr
= section
.addr
+ bfd_section_size (abfd
, asect
);
87 obstack_grow (&objfile
->psymbol_obstack
, §ion
, sizeof(section
));
88 objfile
->sections_end
= (struct obj_section
*) (((int) objfile
->sections_end
) + 1);
91 /* Builds a section table for OBJFILE.
92 Returns 0 if OK, 1 on error. */
95 build_objfile_section_table (objfile
)
96 struct objfile
*objfile
;
98 if (objfile
->sections
)
101 objfile
->sections_end
= 0;
102 bfd_map_over_sections (objfile
->obfd
, add_to_objfile_sections
, (char *)objfile
);
103 objfile
->sections
= obstack_finish (&objfile
->psymbol_obstack
);
104 objfile
->sections_end
= objfile
->sections
+ (int) objfile
->sections_end
;
108 /* Given a pointer to an initialized bfd (ABFD) and a flag that indicates
109 whether or not an objfile is to be mapped (MAPPED), allocate a new objfile
110 struct, fill it in as best we can, link it into the list of all known
111 objfiles, and return a pointer to the new objfile struct. */
114 allocate_objfile (abfd
, mapped
)
118 struct objfile
*objfile
= NULL
;
123 mapped
|= mapped_symbol_files
;
125 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
127 /* If we can support mapped symbol files, try to open/reopen the mapped file
128 that corresponds to the file from which we wish to read symbols. If the
129 objfile is to be mapped, we must malloc the structure itself using the
130 mmap version, and arrange that all memory allocation for the objfile uses
131 the mmap routines. If we are reusing an existing mapped file, from which
132 we get our objfile pointer, we have to make sure that we update the
133 pointers to the alloc/free functions in the obstack, in case these
134 functions have moved within the current gdb. */
136 fd
= open_mapped_file (bfd_get_filename (abfd
), bfd_get_mtime (abfd
),
140 if (((mapto
= map_to_address ()) == 0) ||
141 ((md
= mmalloc_attach (fd
, (void *) mapto
)) == NULL
))
145 else if ((objfile
= (struct objfile
*) mmalloc_getkey (md
, 0)) != NULL
)
147 /* Update memory corruption handler function addresses. */
150 objfile
-> mmfd
= fd
;
151 /* Update pointers to functions to *our* copies */
152 obstack_chunkfun (&objfile
-> psymbol_obstack
, xmmalloc
);
153 obstack_freefun (&objfile
-> psymbol_obstack
, mfree
);
154 obstack_chunkfun (&objfile
-> symbol_obstack
, xmmalloc
);
155 obstack_freefun (&objfile
-> symbol_obstack
, mfree
);
156 obstack_chunkfun (&objfile
-> type_obstack
, xmmalloc
);
157 obstack_freefun (&objfile
-> type_obstack
, mfree
);
158 /* If already in objfile list, unlink it. */
159 unlink_objfile (objfile
);
160 /* Forget things specific to a particular gdb, may have changed. */
161 objfile
-> sf
= NULL
;
165 /* Set up to detect internal memory corruption. MUST be done before
166 the first malloc. See comments in init_malloc() and mmcheck(). */
168 objfile
= (struct objfile
*) xmmalloc (md
, sizeof (struct objfile
));
169 memset (objfile
, 0, sizeof (struct objfile
));
171 objfile
-> mmfd
= fd
;
172 objfile
-> flags
|= OBJF_MAPPED
;
173 mmalloc_setkey (objfile
-> md
, 0, objfile
);
174 obstack_specify_allocation_with_arg (&objfile
-> psymbol_obstack
,
175 0, 0, xmmalloc
, mfree
,
177 obstack_specify_allocation_with_arg (&objfile
-> symbol_obstack
,
178 0, 0, xmmalloc
, mfree
,
180 obstack_specify_allocation_with_arg (&objfile
-> type_obstack
,
181 0, 0, xmmalloc
, mfree
,
186 if (mapped
&& (objfile
== NULL
))
188 warning ("symbol table for '%s' will not be mapped",
189 bfd_get_filename (abfd
));
192 #else /* defined(NO_MMALLOC) || !defined(HAVE_MMAP) */
196 warning ("this version of gdb does not support mapped symbol tables.");
198 /* Turn off the global flag so we don't try to do mapped symbol tables
199 any more, which shuts up gdb unless the user specifically gives the
200 "mapped" keyword again. */
202 mapped_symbol_files
= 0;
205 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
207 /* If we don't support mapped symbol files, didn't ask for the file to be
208 mapped, or failed to open the mapped file for some reason, then revert
209 back to an unmapped objfile. */
213 objfile
= (struct objfile
*) xmalloc (sizeof (struct objfile
));
214 memset (objfile
, 0, sizeof (struct objfile
));
215 objfile
-> md
= NULL
;
216 obstack_specify_allocation (&objfile
-> psymbol_obstack
, 0, 0, xmalloc
,
218 obstack_specify_allocation (&objfile
-> symbol_obstack
, 0, 0, xmalloc
,
220 obstack_specify_allocation (&objfile
-> type_obstack
, 0, 0, xmalloc
,
224 /* Update the per-objfile information that comes from the bfd, ensuring
225 that any data that is reference is saved in the per-objfile data
228 objfile
-> obfd
= abfd
;
229 if (objfile
-> name
!= NULL
)
231 mfree (objfile
-> md
, objfile
-> name
);
233 objfile
-> name
= mstrsave (objfile
-> md
, bfd_get_filename (abfd
));
234 objfile
-> mtime
= bfd_get_mtime (abfd
);
236 /* Build section table. */
238 if (build_objfile_section_table (objfile
))
240 error ("Can't find the file sections in `%s': %s",
241 objfile
-> name
, bfd_errmsg (bfd_error
));
244 /* Push this file onto the head of the linked list of other such files. */
246 objfile
-> next
= object_files
;
247 object_files
= objfile
;
252 /* Unlink OBJFILE from the list of known objfiles, if it is found in the
255 It is not a bug, or error, to call this function if OBJFILE is not known
256 to be in the current list. This is done in the case of mapped objfiles,
257 for example, just to ensure that the mapped objfile doesn't appear twice
258 in the list. Since the list is threaded, linking in a mapped objfile
259 twice would create a circular list.
261 If OBJFILE turns out to be in the list, we zap it's NEXT pointer after
262 unlinking it, just to ensure that we have completely severed any linkages
263 between the OBJFILE and the list. */
266 unlink_objfile (objfile
)
267 struct objfile
*objfile
;
269 struct objfile
** objpp
;
271 for (objpp
= &object_files
; *objpp
!= NULL
; objpp
= &((*objpp
) -> next
))
273 if (*objpp
== objfile
)
275 *objpp
= (*objpp
) -> next
;
276 objfile
-> next
= NULL
;
283 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
284 that as much as possible is allocated on the symbol_obstack and
285 psymbol_obstack, so that the memory can be efficiently freed.
287 Things which we do NOT free because they are not in malloc'd memory
288 or not in memory specific to the objfile include:
292 FIXME: If the objfile is using reusable symbol information (via mmalloc),
293 then we need to take into account the fact that more than one process
294 may be using the symbol information at the same time (when mmalloc is
295 extended to support cooperative locking). When more than one process
296 is using the mapped symbol info, we need to be more careful about when
297 we free objects in the reusable area. */
300 free_objfile (objfile
)
301 struct objfile
*objfile
;
305 /* First do any symbol file specific actions required when we are
306 finished with a particular symbol file. Note that if the objfile
307 is using reusable symbol information (via mmalloc) then each of
308 these routines is responsible for doing the correct thing, either
309 freeing things which are valid only during this particular gdb
310 execution, or leaving them to be reused during the next one. */
312 if (objfile
-> sf
!= NULL
)
314 (*objfile
-> sf
-> sym_finish
) (objfile
);
317 /* We always close the bfd. */
319 if (objfile
-> obfd
!= NULL
)
321 char *name
= bfd_get_filename (objfile
->obfd
);
322 bfd_close (objfile
-> obfd
);
326 /* Remove it from the chain of all objfiles. */
328 unlink_objfile (objfile
);
330 /* Before the symbol table code was redone to make it easier to
331 selectively load and remove information particular to a specific
332 linkage unit, gdb used to do these things whenever the monolithic
333 symbol table was blown away. How much still needs to be done
334 is unknown, but we play it safe for now and keep each action until
335 it is shown to be no longer needed. */
337 clear_symtab_users_once ();
338 #if defined (CLEAR_SOLIB)
341 clear_pc_function_cache ();
343 /* The last thing we do is free the objfile struct itself for the
344 non-reusable case, or detach from the mapped file for the reusable
345 case. Note that the mmalloc_detach or the mfree is the last thing
346 we can do with this objfile. */
348 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
350 if (objfile
-> flags
& OBJF_MAPPED
)
352 /* Remember the fd so we can close it. We can't close it before
353 doing the detach, and after the detach the objfile is gone. */
354 mmfd
= objfile
-> mmfd
;
355 mmalloc_detach (objfile
-> md
);
360 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
362 /* If we still have an objfile, then either we don't support reusable
363 objfiles or this one was not reusable. So free it normally. */
367 if (objfile
-> name
!= NULL
)
369 mfree (objfile
-> md
, objfile
-> name
);
371 if (objfile
->global_psymbols
.list
)
372 mfree (objfile
->md
, objfile
->global_psymbols
.list
);
373 if (objfile
->static_psymbols
.list
)
374 mfree (objfile
->md
, objfile
->static_psymbols
.list
);
375 /* Free the obstacks for non-reusable objfiles */
376 obstack_free (&objfile
-> psymbol_obstack
, 0);
377 obstack_free (&objfile
-> symbol_obstack
, 0);
378 obstack_free (&objfile
-> type_obstack
, 0);
379 mfree (objfile
-> md
, objfile
);
385 /* Free all the object files at once. */
390 struct objfile
*objfile
, *temp
;
392 ALL_OBJFILES_SAFE (objfile
, temp
)
394 free_objfile (objfile
);
398 /* Relocate OBJFILE to NEW_OFFSETS. There should be OBJFILE->NUM_SECTIONS
399 entries in new_offsets. */
401 objfile_relocate (objfile
, new_offsets
)
402 struct objfile
*objfile
;
403 struct section_offsets
*new_offsets
;
405 struct section_offsets
*delta
= (struct section_offsets
*) alloca
406 (sizeof (struct section_offsets
)
407 + objfile
->num_sections
* sizeof (delta
->offsets
));
411 int something_changed
= 0;
412 for (i
= 0; i
< objfile
->num_sections
; ++i
)
414 ANOFFSET (delta
, i
) =
415 ANOFFSET (new_offsets
, i
) - ANOFFSET (objfile
->section_offsets
, i
);
416 if (ANOFFSET (delta
, i
) != 0)
417 something_changed
= 1;
419 if (!something_changed
)
423 /* OK, get all the symtabs. */
427 for (s
= objfile
->symtabs
; s
; s
= s
->next
)
430 struct blockvector
*bv
;
433 /* First the line table. */
437 for (i
= 0; i
< l
->nitems
; ++i
)
438 l
->item
[i
].pc
+= ANOFFSET (delta
, s
->block_line_section
);
441 /* Don't relocate a shared blockvector more than once. */
445 bv
= BLOCKVECTOR (s
);
446 for (i
= 0; i
< BLOCKVECTOR_NBLOCKS (bv
); ++i
)
451 b
= BLOCKVECTOR_BLOCK (bv
, i
);
452 BLOCK_START (b
) += ANOFFSET (delta
, s
->block_line_section
);
453 BLOCK_END (b
) += ANOFFSET (delta
, s
->block_line_section
);
455 for (j
= 0; j
< BLOCK_NSYMS (b
); ++j
)
457 struct symbol
*sym
= BLOCK_SYM (b
, j
);
458 /* The RS6000 code from which this was taken skipped
459 any symbols in STRUCT_NAMESPACE or UNDEF_NAMESPACE.
460 But I'm leaving out that test, on the theory that
461 they can't possibly pass the tests below. */
462 if ((SYMBOL_CLASS (sym
) == LOC_LABEL
463 || SYMBOL_CLASS (sym
) == LOC_STATIC
)
464 && SYMBOL_SECTION (sym
) >= 0)
466 SYMBOL_VALUE_ADDRESS (sym
) +=
467 ANOFFSET (delta
, SYMBOL_SECTION (sym
));
475 struct minimal_symbol
*msym
;
476 ALL_OBJFILE_MSYMBOLS (objfile
, msym
)
477 SYMBOL_VALUE_ADDRESS (msym
) += ANOFFSET (delta
, SYMBOL_SECTION (msym
));
482 for (i
= 0; i
< objfile
->num_sections
; ++i
)
483 ANOFFSET (objfile
->section_offsets
, i
) = ANOFFSET (new_offsets
, i
);
487 /* Many places in gdb want to test just to see if we have any partial
488 symbols available. This function returns zero if none are currently
489 available, nonzero otherwise. */
492 have_partial_symbols ()
498 if (ofp
-> psymtabs
!= NULL
)
506 /* Many places in gdb want to test just to see if we have any full
507 symbols available. This function returns zero if none are currently
508 available, nonzero otherwise. */
517 if (ofp
-> symtabs
!= NULL
)
525 /* Many places in gdb want to test just to see if we have any minimal
526 symbols available. This function returns zero if none are currently
527 available, nonzero otherwise. */
530 have_minimal_symbols ()
536 if (ofp
-> msymbols
!= NULL
)
544 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
546 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
547 of the corresponding symbol file in MTIME, try to open an existing file
548 with the name SYMSFILENAME and verify it is more recent than the base
549 file by checking it's timestamp against MTIME.
551 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
553 If SYMSFILENAME does exist, but is out of date, we check to see if the
554 user has specified creation of a mapped file. If so, we don't issue
555 any warning message because we will be creating a new mapped file anyway,
556 overwriting the old one. If not, then we issue a warning message so that
557 the user will know why we aren't using this existing mapped symbol file.
558 In either case, we return -1.
560 If SYMSFILENAME does exist and is not out of date, but can't be opened for
561 some reason, then prints an appropriate system error message and returns -1.
563 Otherwise, returns the open file descriptor. */
566 open_existing_mapped_file (symsfilename
, mtime
, mapped
)
574 if (stat (symsfilename
, &sbuf
) == 0)
576 if (sbuf
.st_mtime
< mtime
)
580 warning ("mapped symbol file `%s' is out of date, ignored it",
584 else if ((fd
= open (symsfilename
, O_RDWR
)) < 0)
588 printf (error_pre_print
);
590 print_sys_errmsg (symsfilename
, errno
);
596 /* Look for a mapped symbol file that corresponds to FILENAME and is more
597 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
598 use a mapped symbol file for this file, so create a new one if one does
601 If found, then return an open file descriptor for the file, otherwise
604 This routine is responsible for implementing the policy that generates
605 the name of the mapped symbol file from the name of a file containing
606 symbols that gdb would like to read. Currently this policy is to append
607 ".syms" to the name of the file.
609 This routine is also responsible for implementing the policy that
610 determines where the mapped symbol file is found (the search path).
611 This policy is that when reading an existing mapped file, a file of
612 the correct name in the current directory takes precedence over a
613 file of the correct name in the same directory as the symbol file.
614 When creating a new mapped file, it is always created in the current
615 directory. This helps to minimize the chances of a user unknowingly
616 creating big mapped files in places like /bin and /usr/local/bin, and
617 allows a local copy to override a manually installed global copy (in
618 /bin for example). */
621 open_mapped_file (filename
, mtime
, mapped
)
629 /* First try to open an existing file in the current directory, and
630 then try the directory where the symbol file is located. */
632 symsfilename
= concat ("./", basename (filename
), ".syms", (char *) NULL
);
633 if ((fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
)) < 0)
636 symsfilename
= concat (filename
, ".syms", (char *) NULL
);
637 fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
);
640 /* If we don't have an open file by now, then either the file does not
641 already exist, or the base file has changed since it was created. In
642 either case, if the user has specified use of a mapped file, then
643 create a new mapped file, truncating any existing one. If we can't
644 create one, print a system error message saying why we can't.
646 By default the file is rw for everyone, with the user's umask taking
647 care of turning off the permissions the user wants off. */
649 if ((fd
< 0) && mapped
)
652 symsfilename
= concat ("./", basename (filename
), ".syms",
654 if ((fd
= open (symsfilename
, O_RDWR
| O_CREAT
| O_TRUNC
, 0666)) < 0)
658 printf (error_pre_print
);
660 print_sys_errmsg (symsfilename
, errno
);
668 /* Return the base address at which we would like the next objfile's
669 mapped data to start.
671 For now, we use the kludge that the configuration specifies a base
672 address to which it is safe to map the first mmalloc heap, and an
673 increment to add to this address for each successive heap. There are
674 a lot of issues to deal with here to make this work reasonably, including:
676 Avoid memory collisions with existing mapped address spaces
678 Reclaim address spaces when their mmalloc heaps are unmapped
680 When mmalloc heaps are shared between processes they have to be
681 mapped at the same addresses in each
683 Once created, a mmalloc heap that is to be mapped back in must be
684 mapped at the original address. I.E. each objfile will expect to
685 be remapped at it's original address. This becomes a problem if
686 the desired address is already in use.
697 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
699 static CORE_ADDR next
= MMAP_BASE_ADDRESS
;
700 CORE_ADDR mapto
= next
;
702 next
+= MMAP_INCREMENT
;
713 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
715 /* Returns a section whose range includes PC or NULL if none found. */
721 struct obj_section
*s
;
722 struct objfile
*objfile
;
724 ALL_OBJFILES (objfile
)
725 for (s
= objfile
->sections
; s
< objfile
->sections_end
; ++s
)