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 (in which case bfd_error contains the
99 build_objfile_section_table (objfile
)
100 struct objfile
*objfile
;
102 if (objfile
->sections
)
105 objfile
->sections_end
= 0;
106 bfd_map_over_sections (objfile
->obfd
, add_to_objfile_sections
, (char *)objfile
);
107 objfile
->sections
= (struct obj_section
*)
108 obstack_finish (&objfile
->psymbol_obstack
);
109 objfile
->sections_end
= objfile
->sections
+ (unsigned long) objfile
->sections_end
;
113 /* Given a pointer to an initialized bfd (ABFD) and a flag that indicates
114 whether or not an objfile is to be mapped (MAPPED), allocate a new objfile
115 struct, fill it in as best we can, link it into the list of all known
116 objfiles, and return a pointer to the new objfile struct. */
119 allocate_objfile (abfd
, mapped
)
123 struct objfile
*objfile
= NULL
;
125 mapped
|= mapped_symbol_files
;
127 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
130 /* If we can support mapped symbol files, try to open/reopen the
131 mapped file that corresponds to the file from which we wish to
132 read symbols. If the objfile is to be mapped, we must malloc
133 the structure itself using the mmap version, and arrange that
134 all memory allocation for the objfile uses the mmap routines.
135 If we are reusing an existing mapped file, from which we get
136 our objfile pointer, we have to make sure that we update the
137 pointers to the alloc/free functions in the obstack, in case
138 these functions have moved within the current gdb. */
142 fd
= open_mapped_file (bfd_get_filename (abfd
), bfd_get_mtime (abfd
),
149 if (((mapto
= map_to_address ()) == 0) ||
150 ((md
= mmalloc_attach (fd
, (PTR
) mapto
)) == NULL
))
154 else if ((objfile
= (struct objfile
*) mmalloc_getkey (md
, 0)) != NULL
)
156 /* Update memory corruption handler function addresses. */
159 objfile
-> mmfd
= fd
;
160 /* Update pointers to functions to *our* copies */
161 obstack_chunkfun (&objfile
-> psymbol_obstack
, xmmalloc
);
162 obstack_freefun (&objfile
-> psymbol_obstack
, mfree
);
163 obstack_chunkfun (&objfile
-> symbol_obstack
, xmmalloc
);
164 obstack_freefun (&objfile
-> symbol_obstack
, mfree
);
165 obstack_chunkfun (&objfile
-> type_obstack
, xmmalloc
);
166 obstack_freefun (&objfile
-> type_obstack
, mfree
);
167 /* If already in objfile list, unlink it. */
168 unlink_objfile (objfile
);
169 /* Forget things specific to a particular gdb, may have changed. */
170 objfile
-> sf
= NULL
;
175 /* Set up to detect internal memory corruption. MUST be
176 done before the first malloc. See comments in
177 init_malloc() and mmcheck(). */
181 objfile
= (struct objfile
*)
182 xmmalloc (md
, sizeof (struct objfile
));
183 memset (objfile
, 0, sizeof (struct objfile
));
185 objfile
-> mmfd
= fd
;
186 objfile
-> flags
|= OBJF_MAPPED
;
187 mmalloc_setkey (objfile
-> md
, 0, objfile
);
188 obstack_specify_allocation_with_arg (&objfile
-> psymbol_obstack
,
189 0, 0, xmmalloc
, mfree
,
191 obstack_specify_allocation_with_arg (&objfile
-> symbol_obstack
,
192 0, 0, xmmalloc
, mfree
,
194 obstack_specify_allocation_with_arg (&objfile
-> type_obstack
,
195 0, 0, xmmalloc
, mfree
,
200 if (mapped
&& (objfile
== NULL
))
202 warning ("symbol table for '%s' will not be mapped",
203 bfd_get_filename (abfd
));
206 #else /* defined(NO_MMALLOC) || !defined(HAVE_MMAP) */
210 warning ("this version of gdb does not support mapped symbol tables.");
212 /* Turn off the global flag so we don't try to do mapped symbol tables
213 any more, which shuts up gdb unless the user specifically gives the
214 "mapped" keyword again. */
216 mapped_symbol_files
= 0;
219 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
221 /* If we don't support mapped symbol files, didn't ask for the file to be
222 mapped, or failed to open the mapped file for some reason, then revert
223 back to an unmapped objfile. */
227 objfile
= (struct objfile
*) xmalloc (sizeof (struct objfile
));
228 memset (objfile
, 0, sizeof (struct objfile
));
229 objfile
-> md
= NULL
;
230 obstack_specify_allocation (&objfile
-> psymbol_obstack
, 0, 0, xmalloc
,
232 obstack_specify_allocation (&objfile
-> symbol_obstack
, 0, 0, xmalloc
,
234 obstack_specify_allocation (&objfile
-> type_obstack
, 0, 0, xmalloc
,
238 /* Update the per-objfile information that comes from the bfd, ensuring
239 that any data that is reference is saved in the per-objfile data
242 objfile
-> obfd
= abfd
;
243 if (objfile
-> name
!= NULL
)
245 mfree (objfile
-> md
, objfile
-> name
);
247 objfile
-> name
= mstrsave (objfile
-> md
, bfd_get_filename (abfd
));
248 objfile
-> mtime
= bfd_get_mtime (abfd
);
250 /* Build section table. */
252 if (build_objfile_section_table (objfile
))
254 error ("Can't find the file sections in `%s': %s",
255 objfile
-> name
, bfd_errmsg (bfd_error
));
258 /* Push this file onto the head of the linked list of other such files. */
260 objfile
-> next
= object_files
;
261 object_files
= objfile
;
266 /* Unlink OBJFILE from the list of known objfiles, if it is found in the
269 It is not a bug, or error, to call this function if OBJFILE is not known
270 to be in the current list. This is done in the case of mapped objfiles,
271 for example, just to ensure that the mapped objfile doesn't appear twice
272 in the list. Since the list is threaded, linking in a mapped objfile
273 twice would create a circular list.
275 If OBJFILE turns out to be in the list, we zap it's NEXT pointer after
276 unlinking it, just to ensure that we have completely severed any linkages
277 between the OBJFILE and the list. */
280 unlink_objfile (objfile
)
281 struct objfile
*objfile
;
283 struct objfile
** objpp
;
285 for (objpp
= &object_files
; *objpp
!= NULL
; objpp
= &((*objpp
) -> next
))
287 if (*objpp
== objfile
)
289 *objpp
= (*objpp
) -> next
;
290 objfile
-> next
= NULL
;
297 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
298 that as much as possible is allocated on the symbol_obstack and
299 psymbol_obstack, so that the memory can be efficiently freed.
301 Things which we do NOT free because they are not in malloc'd memory
302 or not in memory specific to the objfile include:
306 FIXME: If the objfile is using reusable symbol information (via mmalloc),
307 then we need to take into account the fact that more than one process
308 may be using the symbol information at the same time (when mmalloc is
309 extended to support cooperative locking). When more than one process
310 is using the mapped symbol info, we need to be more careful about when
311 we free objects in the reusable area. */
314 free_objfile (objfile
)
315 struct objfile
*objfile
;
317 /* First do any symbol file specific actions required when we are
318 finished with a particular symbol file. Note that if the objfile
319 is using reusable symbol information (via mmalloc) then each of
320 these routines is responsible for doing the correct thing, either
321 freeing things which are valid only during this particular gdb
322 execution, or leaving them to be reused during the next one. */
324 if (objfile
-> sf
!= NULL
)
326 (*objfile
-> sf
-> sym_finish
) (objfile
);
329 /* We always close the bfd. */
331 if (objfile
-> obfd
!= NULL
)
333 char *name
= bfd_get_filename (objfile
->obfd
);
334 bfd_close (objfile
-> obfd
);
338 /* Remove it from the chain of all objfiles. */
340 unlink_objfile (objfile
);
342 /* Before the symbol table code was redone to make it easier to
343 selectively load and remove information particular to a specific
344 linkage unit, gdb used to do these things whenever the monolithic
345 symbol table was blown away. How much still needs to be done
346 is unknown, but we play it safe for now and keep each action until
347 it is shown to be no longer needed. */
349 #if defined (CLEAR_SOLIB)
351 /* CLEAR_SOLIB closes the bfd's for any shared libraries. But
352 the to_sections for a core file might refer to those bfd's. So
353 detach any core file. */
355 struct target_ops
*t
= find_core_target ();
357 (t
->to_detach
) (NULL
, 0);
360 /* I *think* all our callers call clear_symtab_users. If so, no need
361 to call this here. */
362 clear_pc_function_cache ();
364 /* The last thing we do is free the objfile struct itself for the
365 non-reusable case, or detach from the mapped file for the reusable
366 case. Note that the mmalloc_detach or the mfree is the last thing
367 we can do with this objfile. */
369 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
371 if (objfile
-> flags
& OBJF_MAPPED
)
373 /* Remember the fd so we can close it. We can't close it before
374 doing the detach, and after the detach the objfile is gone. */
377 mmfd
= objfile
-> mmfd
;
378 mmalloc_detach (objfile
-> md
);
383 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
385 /* If we still have an objfile, then either we don't support reusable
386 objfiles or this one was not reusable. So free it normally. */
390 if (objfile
-> name
!= NULL
)
392 mfree (objfile
-> md
, objfile
-> name
);
394 if (objfile
->global_psymbols
.list
)
395 mfree (objfile
->md
, objfile
->global_psymbols
.list
);
396 if (objfile
->static_psymbols
.list
)
397 mfree (objfile
->md
, objfile
->static_psymbols
.list
);
398 /* Free the obstacks for non-reusable objfiles */
399 obstack_free (&objfile
-> psymbol_obstack
, 0);
400 obstack_free (&objfile
-> symbol_obstack
, 0);
401 obstack_free (&objfile
-> type_obstack
, 0);
402 mfree (objfile
-> md
, objfile
);
408 /* Free all the object files at once and clean up their users. */
413 struct objfile
*objfile
, *temp
;
415 ALL_OBJFILES_SAFE (objfile
, temp
)
417 free_objfile (objfile
);
419 clear_symtab_users ();
422 /* Relocate OBJFILE to NEW_OFFSETS. There should be OBJFILE->NUM_SECTIONS
423 entries in new_offsets. */
425 objfile_relocate (objfile
, new_offsets
)
426 struct objfile
*objfile
;
427 struct section_offsets
*new_offsets
;
429 struct section_offsets
*delta
= (struct section_offsets
*) alloca
430 (sizeof (struct section_offsets
)
431 + objfile
->num_sections
* sizeof (delta
->offsets
));
435 int something_changed
= 0;
436 for (i
= 0; i
< objfile
->num_sections
; ++i
)
438 ANOFFSET (delta
, i
) =
439 ANOFFSET (new_offsets
, i
) - ANOFFSET (objfile
->section_offsets
, i
);
440 if (ANOFFSET (delta
, i
) != 0)
441 something_changed
= 1;
443 if (!something_changed
)
447 /* OK, get all the symtabs. */
451 for (s
= objfile
->symtabs
; s
; s
= s
->next
)
454 struct blockvector
*bv
;
457 /* First the line table. */
461 for (i
= 0; i
< l
->nitems
; ++i
)
462 l
->item
[i
].pc
+= ANOFFSET (delta
, s
->block_line_section
);
465 /* Don't relocate a shared blockvector more than once. */
469 bv
= BLOCKVECTOR (s
);
470 for (i
= 0; i
< BLOCKVECTOR_NBLOCKS (bv
); ++i
)
475 b
= BLOCKVECTOR_BLOCK (bv
, i
);
476 BLOCK_START (b
) += ANOFFSET (delta
, s
->block_line_section
);
477 BLOCK_END (b
) += ANOFFSET (delta
, s
->block_line_section
);
479 for (j
= 0; j
< BLOCK_NSYMS (b
); ++j
)
481 struct symbol
*sym
= BLOCK_SYM (b
, j
);
482 /* The RS6000 code from which this was taken skipped
483 any symbols in STRUCT_NAMESPACE or UNDEF_NAMESPACE.
484 But I'm leaving out that test, on the theory that
485 they can't possibly pass the tests below. */
486 if ((SYMBOL_CLASS (sym
) == LOC_LABEL
487 || SYMBOL_CLASS (sym
) == LOC_STATIC
)
488 && SYMBOL_SECTION (sym
) >= 0)
490 SYMBOL_VALUE_ADDRESS (sym
) +=
491 ANOFFSET (delta
, SYMBOL_SECTION (sym
));
499 struct partial_symtab
*p
;
501 ALL_OBJFILE_PSYMTABS (objfile
, p
)
503 /* FIXME: specific to symbol readers which use gdb-stabs.h.
504 We can only get away with it since objfile_relocate is only
505 used on XCOFF, which lacks psymtabs, and for gdb-stabs.h
507 p
->textlow
+= ANOFFSET (delta
, SECT_OFF_TEXT
);
508 p
->texthigh
+= ANOFFSET (delta
, SECT_OFF_TEXT
);
513 struct partial_symbol
*psym
;
515 for (psym
= objfile
->global_psymbols
.list
;
516 psym
< objfile
->global_psymbols
.next
;
518 if (SYMBOL_SECTION (psym
) >= 0)
519 SYMBOL_VALUE_ADDRESS (psym
) += ANOFFSET (delta
, SYMBOL_SECTION (psym
));
520 for (psym
= objfile
->static_psymbols
.list
;
521 psym
< objfile
->static_psymbols
.next
;
523 if (SYMBOL_SECTION (psym
) >= 0)
524 SYMBOL_VALUE_ADDRESS (psym
) += ANOFFSET (delta
, SYMBOL_SECTION (psym
));
528 struct minimal_symbol
*msym
;
529 ALL_OBJFILE_MSYMBOLS (objfile
, msym
)
530 if (SYMBOL_SECTION (msym
) >= 0)
531 SYMBOL_VALUE_ADDRESS (msym
) += ANOFFSET (delta
, SYMBOL_SECTION (msym
));
536 for (i
= 0; i
< objfile
->num_sections
; ++i
)
537 ANOFFSET (objfile
->section_offsets
, i
) = ANOFFSET (new_offsets
, i
);
541 /* Many places in gdb want to test just to see if we have any partial
542 symbols available. This function returns zero if none are currently
543 available, nonzero otherwise. */
546 have_partial_symbols ()
552 if (ofp
-> psymtabs
!= NULL
)
560 /* Many places in gdb want to test just to see if we have any full
561 symbols available. This function returns zero if none are currently
562 available, nonzero otherwise. */
571 if (ofp
-> symtabs
!= NULL
)
579 /* Many places in gdb want to test just to see if we have any minimal
580 symbols available. This function returns zero if none are currently
581 available, nonzero otherwise. */
584 have_minimal_symbols ()
590 if (ofp
-> msymbols
!= NULL
)
598 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
600 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
601 of the corresponding symbol file in MTIME, try to open an existing file
602 with the name SYMSFILENAME and verify it is more recent than the base
603 file by checking it's timestamp against MTIME.
605 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
607 If SYMSFILENAME does exist, but is out of date, we check to see if the
608 user has specified creation of a mapped file. If so, we don't issue
609 any warning message because we will be creating a new mapped file anyway,
610 overwriting the old one. If not, then we issue a warning message so that
611 the user will know why we aren't using this existing mapped symbol file.
612 In either case, we return -1.
614 If SYMSFILENAME does exist and is not out of date, but can't be opened for
615 some reason, then prints an appropriate system error message and returns -1.
617 Otherwise, returns the open file descriptor. */
620 open_existing_mapped_file (symsfilename
, mtime
, mapped
)
628 if (stat (symsfilename
, &sbuf
) == 0)
630 if (sbuf
.st_mtime
< mtime
)
634 warning ("mapped symbol file `%s' is out of date, ignored it",
638 else if ((fd
= open (symsfilename
, O_RDWR
)) < 0)
642 printf_unfiltered (error_pre_print
);
644 print_sys_errmsg (symsfilename
, errno
);
650 /* Look for a mapped symbol file that corresponds to FILENAME and is more
651 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
652 use a mapped symbol file for this file, so create a new one if one does
655 If found, then return an open file descriptor for the file, otherwise
658 This routine is responsible for implementing the policy that generates
659 the name of the mapped symbol file from the name of a file containing
660 symbols that gdb would like to read. Currently this policy is to append
661 ".syms" to the name of the file.
663 This routine is also responsible for implementing the policy that
664 determines where the mapped symbol file is found (the search path).
665 This policy is that when reading an existing mapped file, a file of
666 the correct name in the current directory takes precedence over a
667 file of the correct name in the same directory as the symbol file.
668 When creating a new mapped file, it is always created in the current
669 directory. This helps to minimize the chances of a user unknowingly
670 creating big mapped files in places like /bin and /usr/local/bin, and
671 allows a local copy to override a manually installed global copy (in
672 /bin for example). */
675 open_mapped_file (filename
, mtime
, mapped
)
683 /* First try to open an existing file in the current directory, and
684 then try the directory where the symbol file is located. */
686 symsfilename
= concat ("./", basename (filename
), ".syms", (char *) NULL
);
687 if ((fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
)) < 0)
690 symsfilename
= concat (filename
, ".syms", (char *) NULL
);
691 fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
);
694 /* If we don't have an open file by now, then either the file does not
695 already exist, or the base file has changed since it was created. In
696 either case, if the user has specified use of a mapped file, then
697 create a new mapped file, truncating any existing one. If we can't
698 create one, print a system error message saying why we can't.
700 By default the file is rw for everyone, with the user's umask taking
701 care of turning off the permissions the user wants off. */
703 if ((fd
< 0) && mapped
)
706 symsfilename
= concat ("./", basename (filename
), ".syms",
708 if ((fd
= open (symsfilename
, O_RDWR
| O_CREAT
| O_TRUNC
, 0666)) < 0)
712 printf_unfiltered (error_pre_print
);
714 print_sys_errmsg (symsfilename
, errno
);
722 /* Return the base address at which we would like the next objfile's
723 mapped data to start.
725 For now, we use the kludge that the configuration specifies a base
726 address to which it is safe to map the first mmalloc heap, and an
727 increment to add to this address for each successive heap. There are
728 a lot of issues to deal with here to make this work reasonably, including:
730 Avoid memory collisions with existing mapped address spaces
732 Reclaim address spaces when their mmalloc heaps are unmapped
734 When mmalloc heaps are shared between processes they have to be
735 mapped at the same addresses in each
737 Once created, a mmalloc heap that is to be mapped back in must be
738 mapped at the original address. I.E. each objfile will expect to
739 be remapped at it's original address. This becomes a problem if
740 the desired address is already in use.
751 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
753 static CORE_ADDR next
= MMAP_BASE_ADDRESS
;
754 CORE_ADDR mapto
= next
;
756 next
+= MMAP_INCREMENT
;
767 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
769 /* Returns a section whose range includes PC or NULL if none found. */
775 struct obj_section
*s
;
776 struct objfile
*objfile
;
778 ALL_OBJFILES (objfile
)
779 for (s
= objfile
->sections
; s
< objfile
->sections_end
; ++s
)