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_specify_allocation_with_arg (&objfile -> psymbol_obstack,
130 0, 0, xmmalloc, mfree,
132 obstack_specify_allocation_with_arg (&objfile -> symbol_obstack,
133 0, 0, xmmalloc, mfree,
135 obstack_specify_allocation_with_arg (&objfile -> type_obstack,
136 0, 0, xmmalloc, mfree,
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_specify_allocation (&objfile -> psymbol_obstack, 0, 0, xmalloc,
173 obstack_specify_allocation (&objfile -> symbol_obstack, 0, 0, xmalloc,
175 obstack_specify_allocation (&objfile -> type_obstack, 0, 0, xmalloc,
179 /* Update the per-objfile information that comes from the bfd, ensuring
180 that any data that is reference is saved in the per-objfile data
183 objfile -> obfd = abfd;
184 if (objfile -> name != NULL)
186 mfree (objfile -> md, objfile -> name);
188 objfile -> name = mstrsave (objfile -> md, bfd_get_filename (abfd));
189 objfile -> mtime = bfd_get_mtime (abfd);
191 /* Push this file onto the head of the linked list of other such files. */
193 objfile -> next = object_files;
194 object_files = objfile;
199 /* Unlink OBJFILE from the list of known objfiles, if it is found in the
202 It is not a bug, or error, to call this function if OBJFILE is not known
203 to be in the current list. This is done in the case of mapped objfiles,
204 for example, just to ensure that the mapped objfile doesn't appear twice
205 in the list. Since the list is threaded, linking in a mapped objfile
206 twice would create a circular list.
208 If OBJFILE turns out to be in the list, we zap it's NEXT pointer after
209 unlinking it, just to ensure that we have completely severed any linkages
210 between the OBJFILE and the list. */
213 unlink_objfile (objfile)
214 struct objfile *objfile;
216 struct objfile** objpp;
218 for (objpp = &object_files; *objpp != NULL; objpp = &((*objpp) -> next))
220 if (*objpp == objfile)
222 *objpp = (*objpp) -> next;
223 objfile -> next = NULL;
230 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
231 that as much as possible is allocated on the symbol_obstack and
232 psymbol_obstack, so that the memory can be efficiently freed.
234 Things which we do NOT free because they are not in malloc'd memory
235 or not in memory specific to the objfile include:
239 FIXME: If the objfile is using reusable symbol information (via mmalloc),
240 then we need to take into account the fact that more than one process
241 may be using the symbol information at the same time (when mmalloc is
242 extended to support cooperative locking). When more than one process
243 is using the mapped symbol info, we need to be more careful about when
244 we free objects in the reusable area. */
247 free_objfile (objfile)
248 struct objfile *objfile;
252 /* First do any symbol file specific actions required when we are
253 finished with a particular symbol file. Note that if the objfile
254 is using reusable symbol information (via mmalloc) then each of
255 these routines is responsible for doing the correct thing, either
256 freeing things which are valid only during this particular gdb
257 execution, or leaving them to be reused during the next one. */
259 if (objfile -> sf != NULL)
261 (*objfile -> sf -> sym_finish) (objfile);
264 /* We always close the bfd. */
266 if (objfile -> obfd != NULL)
268 char *name = bfd_get_filename (objfile->obfd);
269 bfd_close (objfile -> obfd);
273 /* Remove it from the chain of all objfiles. */
275 unlink_objfile (objfile);
277 /* Before the symbol table code was redone to make it easier to
278 selectively load and remove information particular to a specific
279 linkage unit, gdb used to do these things whenever the monolithic
280 symbol table was blown away. How much still needs to be done
281 is unknown, but we play it safe for now and keep each action until
282 it is shown to be no longer needed. */
284 clear_symtab_users_once ();
285 #if defined (CLEAR_SOLIB)
288 clear_pc_function_cache ();
290 /* The last thing we do is free the objfile struct itself for the
291 non-reusable case, or detach from the mapped file for the reusable
292 case. Note that the mmalloc_detach or the mfree is the last thing
293 we can do with this objfile. */
295 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
297 if (objfile -> flags & OBJF_MAPPED)
299 /* Remember the fd so we can close it. We can't close it before
300 doing the detach, and after the detach the objfile is gone. */
301 mmfd = objfile -> mmfd;
302 mmalloc_detach (objfile -> md);
307 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
309 /* If we still have an objfile, then either we don't support reusable
310 objfiles or this one was not reusable. So free it normally. */
314 if (objfile -> name != NULL)
316 mfree (objfile -> md, objfile -> name);
318 if (objfile->global_psymbols.list)
319 mfree (objfile->md, objfile->global_psymbols.list);
320 if (objfile->static_psymbols.list)
321 mfree (objfile->md, objfile->static_psymbols.list);
322 /* Free the obstacks for non-reusable objfiles */
323 obstack_free (&objfile -> psymbol_obstack, 0);
324 obstack_free (&objfile -> symbol_obstack, 0);
325 obstack_free (&objfile -> type_obstack, 0);
326 mfree (objfile -> md, objfile);
332 /* Free all the object files at once. */
337 struct objfile *objfile, *temp;
339 ALL_OBJFILES_SAFE (objfile, temp)
341 free_objfile (objfile);
345 /* Relocate OBJFILE to NEW_OFFSETS. There should be OBJFILE->NUM_SECTIONS
346 entries in new_offsets. */
348 objfile_relocate (objfile, new_offsets)
349 struct objfile *objfile;
350 struct section_offsets *new_offsets;
352 struct section_offsets *delta = (struct section_offsets *) alloca
353 (sizeof (struct section_offsets)
354 + objfile->num_sections * sizeof (delta->offsets));
358 int something_changed = 0;
359 for (i = 0; i < objfile->num_sections; ++i)
361 ANOFFSET (delta, i) =
362 ANOFFSET (new_offsets, i) - ANOFFSET (objfile->section_offsets, i);
363 if (ANOFFSET (delta, i) != 0)
364 something_changed = 1;
366 if (!something_changed)
370 /* OK, get all the symtabs. */
374 for (s = objfile->symtabs; s; s = s->next)
377 struct blockvector *bv;
380 /* First the line table. */
384 for (i = 0; i < l->nitems; ++i)
385 l->item[i].pc += ANOFFSET (delta, s->block_line_section);
388 /* Don't relocate a shared blockvector more than once. */
392 bv = BLOCKVECTOR (s);
393 for (i = 0; i < BLOCKVECTOR_NBLOCKS (bv); ++i)
398 b = BLOCKVECTOR_BLOCK (bv, i);
399 BLOCK_START (b) += ANOFFSET (delta, s->block_line_section);
400 BLOCK_END (b) += ANOFFSET (delta, s->block_line_section);
402 for (j = 0; j < BLOCK_NSYMS (b); ++j)
404 struct symbol *sym = BLOCK_SYM (b, j);
405 /* The RS6000 code from which this was taken skipped
406 any symbols in STRUCT_NAMESPACE or UNDEF_NAMESPACE.
407 But I'm leaving out that test, on the theory that
408 they can't possibly pass the tests below. */
409 if ((SYMBOL_CLASS (sym) == LOC_LABEL
410 || SYMBOL_CLASS (sym) == LOC_STATIC)
411 && SYMBOL_SECTION (sym) >= 0)
413 SYMBOL_VALUE_ADDRESS (sym) +=
414 ANOFFSET (delta, SYMBOL_SECTION (sym));
422 struct minimal_symbol *msym;
423 ALL_OBJFILE_MSYMBOLS (objfile, msym)
424 SYMBOL_VALUE_ADDRESS (msym) += ANOFFSET (delta, SYMBOL_SECTION (msym));
429 for (i = 0; i < objfile->num_sections; ++i)
430 ANOFFSET (objfile->section_offsets, i) = ANOFFSET (new_offsets, i);
434 /* Many places in gdb want to test just to see if we have any partial
435 symbols available. This function returns zero if none are currently
436 available, nonzero otherwise. */
439 have_partial_symbols ()
445 if (ofp -> psymtabs != NULL)
453 /* Many places in gdb want to test just to see if we have any full
454 symbols available. This function returns zero if none are currently
455 available, nonzero otherwise. */
464 if (ofp -> symtabs != NULL)
472 /* Many places in gdb want to test just to see if we have any minimal
473 symbols available. This function returns zero if none are currently
474 available, nonzero otherwise. */
477 have_minimal_symbols ()
483 if (ofp -> msymbols != NULL)
491 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
493 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
494 of the corresponding symbol file in MTIME, try to open an existing file
495 with the name SYMSFILENAME and verify it is more recent than the base
496 file by checking it's timestamp against MTIME.
498 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
500 If SYMSFILENAME does exist, but is out of date, we check to see if the
501 user has specified creation of a mapped file. If so, we don't issue
502 any warning message because we will be creating a new mapped file anyway,
503 overwriting the old one. If not, then we issue a warning message so that
504 the user will know why we aren't using this existing mapped symbol file.
505 In either case, we return -1.
507 If SYMSFILENAME does exist and is not out of date, but can't be opened for
508 some reason, then prints an appropriate system error message and returns -1.
510 Otherwise, returns the open file descriptor. */
513 open_existing_mapped_file (symsfilename, mtime, mapped)
521 if (stat (symsfilename, &sbuf) == 0)
523 if (sbuf.st_mtime < mtime)
527 warning ("mapped symbol file `%s' is out of date, ignored it",
531 else if ((fd = open (symsfilename, O_RDWR)) < 0)
535 printf (error_pre_print);
537 print_sys_errmsg (symsfilename, errno);
543 /* Look for a mapped symbol file that corresponds to FILENAME and is more
544 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
545 use a mapped symbol file for this file, so create a new one if one does
548 If found, then return an open file descriptor for the file, otherwise
551 This routine is responsible for implementing the policy that generates
552 the name of the mapped symbol file from the name of a file containing
553 symbols that gdb would like to read. Currently this policy is to append
554 ".syms" to the name of the file.
556 This routine is also responsible for implementing the policy that
557 determines where the mapped symbol file is found (the search path).
558 This policy is that when reading an existing mapped file, a file of
559 the correct name in the current directory takes precedence over a
560 file of the correct name in the same directory as the symbol file.
561 When creating a new mapped file, it is always created in the current
562 directory. This helps to minimize the chances of a user unknowingly
563 creating big mapped files in places like /bin and /usr/local/bin, and
564 allows a local copy to override a manually installed global copy (in
565 /bin for example). */
568 open_mapped_file (filename, mtime, mapped)
576 /* First try to open an existing file in the current directory, and
577 then try the directory where the symbol file is located. */
579 symsfilename = concat ("./", basename (filename), ".syms", (char *) NULL);
580 if ((fd = open_existing_mapped_file (symsfilename, mtime, mapped)) < 0)
583 symsfilename = concat (filename, ".syms", (char *) NULL);
584 fd = open_existing_mapped_file (symsfilename, mtime, mapped);
587 /* If we don't have an open file by now, then either the file does not
588 already exist, or the base file has changed since it was created. In
589 either case, if the user has specified use of a mapped file, then
590 create a new mapped file, truncating any existing one. If we can't
591 create one, print a system error message saying why we can't.
593 By default the file is rw for everyone, with the user's umask taking
594 care of turning off the permissions the user wants off. */
596 if ((fd < 0) && mapped)
599 symsfilename = concat ("./", basename (filename), ".syms",
601 if ((fd = open (symsfilename, O_RDWR | O_CREAT | O_TRUNC, 0666)) < 0)
605 printf (error_pre_print);
607 print_sys_errmsg (symsfilename, errno);
615 /* Return the base address at which we would like the next objfile's
616 mapped data to start.
618 For now, we use the kludge that the configuration specifies a base
619 address to which it is safe to map the first mmalloc heap, and an
620 increment to add to this address for each successive heap. There are
621 a lot of issues to deal with here to make this work reasonably, including:
623 Avoid memory collisions with existing mapped address spaces
625 Reclaim address spaces when their mmalloc heaps are unmapped
627 When mmalloc heaps are shared between processes they have to be
628 mapped at the same addresses in each
630 Once created, a mmalloc heap that is to be mapped back in must be
631 mapped at the original address. I.E. each objfile will expect to
632 be remapped at it's original address. This becomes a problem if
633 the desired address is already in use.
644 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
646 static CORE_ADDR next = MMAP_BASE_ADDRESS;
647 CORE_ADDR mapto = next;
649 next += MMAP_INCREMENT;
660 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */