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 /* Given a pointer to an initialized bfd (ABFD) and a flag that indicates
64 whether or not an objfile is to be mapped (MAPPED), allocate a new objfile
65 struct, fill it in as best we can, link it into the list of all known
66 objfiles, and return a pointer to the new objfile struct. */
69 allocate_objfile (abfd
, mapped
)
73 struct objfile
*objfile
= NULL
;
78 mapped
|= mapped_symbol_files
;
80 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
82 /* If we can support mapped symbol files, try to open/reopen the mapped file
83 that corresponds to the file from which we wish to read symbols. If the
84 objfile is to be mapped, we must malloc the structure itself using the
85 mmap version, and arrange that all memory allocation for the objfile uses
86 the mmap routines. If we are reusing an existing mapped file, from which
87 we get our objfile pointer, we have to make sure that we update the
88 pointers to the alloc/free functions in the obstack, in case these
89 functions have moved within the current gdb. */
91 fd
= open_mapped_file (bfd_get_filename (abfd
), bfd_get_mtime (abfd
),
95 if (((mapto
= map_to_address ()) == 0) ||
96 ((md
= mmalloc_attach (fd
, (void *) mapto
)) == NULL
))
100 else if ((objfile
= (struct objfile
*) mmalloc_getkey (md
, 0)) != NULL
)
102 /* Update memory corruption handler function addresses. */
105 objfile
-> mmfd
= fd
;
106 /* Update pointers to functions to *our* copies */
107 obstack_chunkfun (&objfile
-> psymbol_obstack
, xmmalloc
);
108 obstack_freefun (&objfile
-> psymbol_obstack
, mfree
);
109 obstack_chunkfun (&objfile
-> symbol_obstack
, xmmalloc
);
110 obstack_freefun (&objfile
-> symbol_obstack
, mfree
);
111 obstack_chunkfun (&objfile
-> type_obstack
, xmmalloc
);
112 obstack_freefun (&objfile
-> type_obstack
, mfree
);
113 /* If already in objfile list, unlink it. */
114 unlink_objfile (objfile
);
115 /* Forget things specific to a particular gdb, may have changed. */
116 objfile
-> sf
= NULL
;
120 /* Set up to detect internal memory corruption. MUST be done before
121 the first malloc. See comments in init_malloc() and mmcheck(). */
123 objfile
= (struct objfile
*) xmmalloc (md
, sizeof (struct objfile
));
124 memset (objfile
, 0, sizeof (struct objfile
));
126 objfile
-> mmfd
= fd
;
127 objfile
-> flags
|= OBJF_MAPPED
;
128 mmalloc_setkey (objfile
-> md
, 0, objfile
);
129 obstack_alloc_arg (&objfile
-> psymbol_obstack
, objfile
-> md
);
130 obstack_full_begin (&objfile
-> psymbol_obstack
, 0, 0, xmmalloc
,
132 obstack_alloc_arg (&objfile
-> symbol_obstack
, objfile
-> md
);
133 obstack_full_begin (&objfile
-> symbol_obstack
, 0, 0, xmmalloc
,
135 obstack_alloc_arg (&objfile
-> type_obstack
, objfile
-> md
);
136 obstack_full_begin (&objfile
-> type_obstack
, 0, 0, xmmalloc
,
141 if (mapped
&& (objfile
== NULL
))
143 warning ("symbol table for '%s' will not be mapped",
144 bfd_get_filename (abfd
));
147 #else /* defined(NO_MMALLOC) || !defined(HAVE_MMAP) */
151 warning ("this version of gdb does not support mapped symbol tables.");
153 /* Turn off the global flag so we don't try to do mapped symbol tables
154 any more, which shuts up gdb unless the user specifically gives the
155 "mapped" keyword again. */
157 mapped_symbol_files
= 0;
160 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
162 /* If we don't support mapped symbol files, didn't ask for the file to be
163 mapped, or failed to open the mapped file for some reason, then revert
164 back to an unmapped objfile. */
168 objfile
= (struct objfile
*) xmalloc (sizeof (struct objfile
));
169 memset (objfile
, 0, sizeof (struct objfile
));
170 objfile
-> md
= NULL
;
171 obstack_full_begin (&objfile
-> psymbol_obstack
, 0, 0, xmalloc
, free
);
172 obstack_full_begin (&objfile
-> symbol_obstack
, 0, 0, xmalloc
, free
);
173 obstack_full_begin (&objfile
-> type_obstack
, 0, 0, xmalloc
, free
);
176 /* Update the per-objfile information that comes from the bfd, ensuring
177 that any data that is reference is saved in the per-objfile data
180 objfile
-> obfd
= abfd
;
181 if (objfile
-> name
!= NULL
)
183 mfree (objfile
-> md
, objfile
-> name
);
185 objfile
-> name
= mstrsave (objfile
-> md
, bfd_get_filename (abfd
));
186 objfile
-> mtime
= bfd_get_mtime (abfd
);
188 /* Push this file onto the head of the linked list of other such files. */
190 objfile
-> next
= object_files
;
191 object_files
= objfile
;
196 /* Unlink OBJFILE from the list of known objfiles, if it is found in the
199 It is not a bug, or error, to call this function if OBJFILE is not known
200 to be in the current list. This is done in the case of mapped objfiles,
201 for example, just to ensure that the mapped objfile doesn't appear twice
202 in the list. Since the list is threaded, linking in a mapped objfile
203 twice would create a circular list.
205 If OBJFILE turns out to be in the list, we zap it's NEXT pointer after
206 unlinking it, just to ensure that we have completely severed any linkages
207 between the OBJFILE and the list. */
210 unlink_objfile (objfile
)
211 struct objfile
*objfile
;
213 struct objfile
** objpp
;
215 for (objpp
= &object_files
; *objpp
!= NULL
; objpp
= &((*objpp
) -> next
))
217 if (*objpp
== objfile
)
219 *objpp
= (*objpp
) -> next
;
220 objfile
-> next
= NULL
;
227 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
228 that as much as possible is allocated on the symbol_obstack and
229 psymbol_obstack, so that the memory can be efficiently freed.
231 Things which we do NOT free because they are not in malloc'd memory
232 or not in memory specific to the objfile include:
236 FIXME: If the objfile is using reusable symbol information (via mmalloc),
237 then we need to take into account the fact that more than one process
238 may be using the symbol information at the same time (when mmalloc is
239 extended to support cooperative locking). When more than one process
240 is using the mapped symbol info, we need to be more careful about when
241 we free objects in the reusable area. */
244 free_objfile (objfile
)
245 struct objfile
*objfile
;
249 /* First do any symbol file specific actions required when we are
250 finished with a particular symbol file. Note that if the objfile
251 is using reusable symbol information (via mmalloc) then each of
252 these routines is responsible for doing the correct thing, either
253 freeing things which are valid only during this particular gdb
254 execution, or leaving them to be reused during the next one. */
256 if (objfile
-> sf
!= NULL
)
258 (*objfile
-> sf
-> sym_finish
) (objfile
);
261 /* We always close the bfd. */
263 if (objfile
-> obfd
!= NULL
)
265 char *name
= bfd_get_filename (objfile
->obfd
);
266 bfd_close (objfile
-> obfd
);
270 /* Remove it from the chain of all objfiles. */
272 unlink_objfile (objfile
);
274 /* Before the symbol table code was redone to make it easier to
275 selectively load and remove information particular to a specific
276 linkage unit, gdb used to do these things whenever the monolithic
277 symbol table was blown away. How much still needs to be done
278 is unknown, but we play it safe for now and keep each action until
279 it is shown to be no longer needed. */
281 clear_symtab_users_once ();
282 #if defined (CLEAR_SOLIB)
285 clear_pc_function_cache ();
287 /* The last thing we do is free the objfile struct itself for the
288 non-reusable case, or detach from the mapped file for the reusable
289 case. Note that the mmalloc_detach or the mfree is the last thing
290 we can do with this objfile. */
292 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
294 if (objfile
-> flags
& OBJF_MAPPED
)
296 /* Remember the fd so we can close it. We can't close it before
297 doing the detach, and after the detach the objfile is gone. */
298 mmfd
= objfile
-> mmfd
;
299 mmalloc_detach (objfile
-> md
);
304 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
306 /* If we still have an objfile, then either we don't support reusable
307 objfiles or this one was not reusable. So free it normally. */
311 if (objfile
-> name
!= NULL
)
313 mfree (objfile
-> md
, objfile
-> name
);
315 if (objfile
->global_psymbols
.list
)
316 mfree (objfile
->md
, objfile
->global_psymbols
.list
);
317 if (objfile
->static_psymbols
.list
)
318 mfree (objfile
->md
, objfile
->static_psymbols
.list
);
319 /* Free the obstacks for non-reusable objfiles */
320 obstack_free (&objfile
-> psymbol_obstack
, 0);
321 obstack_free (&objfile
-> symbol_obstack
, 0);
322 obstack_free (&objfile
-> type_obstack
, 0);
323 mfree (objfile
-> md
, objfile
);
329 /* Free all the object files at once. */
334 struct objfile
*objfile
, *temp
;
336 ALL_OBJFILES_SAFE (objfile
, temp
)
338 free_objfile (objfile
);
342 /* Many places in gdb want to test just to see if we have any partial
343 symbols available. This function returns zero if none are currently
344 available, nonzero otherwise. */
347 have_partial_symbols ()
353 if (ofp
-> psymtabs
!= NULL
)
361 /* Many places in gdb want to test just to see if we have any full
362 symbols available. This function returns zero if none are currently
363 available, nonzero otherwise. */
372 if (ofp
-> symtabs
!= NULL
)
380 /* Many places in gdb want to test just to see if we have any minimal
381 symbols available. This function returns zero if none are currently
382 available, nonzero otherwise. */
385 have_minimal_symbols ()
391 if (ofp
-> msymbols
!= NULL
)
399 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
401 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
402 of the corresponding symbol file in MTIME, try to open an existing file
403 with the name SYMSFILENAME and verify it is more recent than the base
404 file by checking it's timestamp against MTIME.
406 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
408 If SYMSFILENAME does exist, but is out of date, we check to see if the
409 user has specified creation of a mapped file. If so, we don't issue
410 any warning message because we will be creating a new mapped file anyway,
411 overwriting the old one. If not, then we issue a warning message so that
412 the user will know why we aren't using this existing mapped symbol file.
413 In either case, we return -1.
415 If SYMSFILENAME does exist and is not out of date, but can't be opened for
416 some reason, then prints an appropriate system error message and returns -1.
418 Otherwise, returns the open file descriptor. */
421 open_existing_mapped_file (symsfilename
, mtime
, mapped
)
429 if (stat (symsfilename
, &sbuf
) == 0)
431 if (sbuf
.st_mtime
< mtime
)
435 warning ("mapped symbol file `%s' is out of date", symsfilename
);
438 else if ((fd
= open (symsfilename
, O_RDWR
)) < 0)
442 printf (error_pre_print
);
444 print_sys_errmsg (symsfilename
, errno
);
450 /* Look for a mapped symbol file that corresponds to FILENAME and is more
451 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
452 use a mapped symbol file for this file, so create a new one if one does
455 If found, then return an open file descriptor for the file, otherwise
458 This routine is responsible for implementing the policy that generates
459 the name of the mapped symbol file from the name of a file containing
460 symbols that gdb would like to read. Currently this policy is to append
461 ".syms" to the name of the file.
463 This routine is also responsible for implementing the policy that
464 determines where the mapped symbol file is found (the search path).
465 This policy is that when reading an existing mapped file, a file of
466 the correct name in the current directory takes precedence over a
467 file of the correct name in the same directory as the symbol file.
468 When creating a new mapped file, it is always created in the current
469 directory. This helps to minimize the chances of a user unknowingly
470 creating big mapped files in places like /bin and /usr/local/bin, and
471 allows a local copy to override a manually installed global copy (in
472 /bin for example). */
475 open_mapped_file (filename
, mtime
, mapped
)
483 /* First try to open an existing file in the current directory, and
484 then try the directory where the symbol file is located. */
486 symsfilename
= concat ("./", basename (filename
), ".syms", (char *) NULL
);
487 if ((fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
)) < 0)
490 symsfilename
= concat (filename
, ".syms", (char *) NULL
);
491 fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
);
494 /* If we don't have an open file by now, then either the file does not
495 already exist, or the base file has changed since it was created. In
496 either case, if the user has specified use of a mapped file, then
497 create a new mapped file, truncating any existing one. If we can't
498 create one, print a system error message saying why we can't.
500 By default the file is rw for everyone, with the user's umask taking
501 care of turning off the permissions the user wants off. */
503 if ((fd
< 0) && mapped
)
506 symsfilename
= concat ("./", basename (filename
), ".syms",
508 if ((fd
= open (symsfilename
, O_RDWR
| O_CREAT
| O_TRUNC
, 0666)) < 0)
512 printf (error_pre_print
);
514 print_sys_errmsg (symsfilename
, errno
);
522 /* Return the base address at which we would like the next objfile's
523 mapped data to start.
525 For now, we use the kludge that the configuration specifies a base
526 address to which it is safe to map the first mmalloc heap, and an
527 increment to add to this address for each successive heap. There are
528 a lot of issues to deal with here to make this work reasonably, including:
530 Avoid memory collisions with existing mapped address spaces
532 Reclaim address spaces when their mmalloc heaps are unmapped
534 When mmalloc heaps are shared between processes they have to be
535 mapped at the same addresses in each
537 Once created, a mmalloc heap that is to be mapped back in must be
538 mapped at the original address. I.E. each objfile will expect to
539 be remapped at it's original address. This becomes a problem if
540 the desired address is already in use.
551 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
553 static CORE_ADDR next
= MMAP_BASE_ADDRESS
;
554 CORE_ADDR mapto
= next
;
556 next
+= MMAP_INCREMENT
;
567 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */