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"
31 #include <sys/types.h>
36 /* Prototypes for local functions */
38 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
41 open_existing_mapped_file PARAMS ((char *, long, int));
44 open_mapped_file PARAMS ((char *filename, long mtime, int mapped));
47 map_to_address PARAMS ((void));
49 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
51 /* Message to be printed before the error message, when an error occurs. */
53 extern char *error_pre_print;
55 /* Externally visible variables that are owned by this module.
56 See declarations in objfile.h for more info. */
58 struct objfile *object_files; /* Linked list of all objfiles */
59 struct objfile *current_objfile; /* For symbol file being read in */
60 struct objfile *symfile_objfile; /* Main symbol table loaded from */
62 int mapped_symbol_files; /* Try to use mapped symbol files */
64 /* Locate all mappable sections of a BFD file.
65 objfile_p_char is a char * to get it through
66 bfd_map_over_sections; we cast it back to its proper type. */
69 add_to_objfile_sections (abfd, asect, objfile_p_char)
74 struct objfile *objfile = (struct objfile *) objfile_p_char;
75 struct obj_section section;
78 aflag = bfd_get_section_flags (abfd, asect);
79 /* FIXME, we need to handle BSS segment here...it alloc's but doesn't load */
80 if (!(aflag & SEC_LOAD))
82 if (0 == bfd_section_size (abfd, asect))
85 section.objfile = objfile;
86 section.sec_ptr = asect;
87 section.addr = bfd_section_vma (abfd, asect);
88 section.endaddr = section.addr + bfd_section_size (abfd, asect);
89 obstack_grow (&objfile->psymbol_obstack, §ion, sizeof(section));
90 objfile->sections_end = (struct obj_section *) (((int) objfile->sections_end) + 1);
93 /* Builds a section table for OBJFILE.
94 Returns 0 if OK, 1 on error. */
97 build_objfile_section_table (objfile)
98 struct objfile *objfile;
100 if (objfile->sections)
103 objfile->sections_end = 0;
104 bfd_map_over_sections (objfile->obfd, add_to_objfile_sections, (char *)objfile);
105 objfile->sections = (struct obj_section *)
106 obstack_finish (&objfile->psymbol_obstack);
107 objfile->sections_end = objfile->sections + (int) objfile->sections_end;
111 /* Given a pointer to an initialized bfd (ABFD) and a flag that indicates
112 whether or not an objfile is to be mapped (MAPPED), allocate a new objfile
113 struct, fill it in as best we can, link it into the list of all known
114 objfiles, and return a pointer to the new objfile struct. */
117 allocate_objfile (abfd, mapped)
121 struct objfile *objfile = NULL;
126 mapped |= mapped_symbol_files;
128 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
130 /* If we can support mapped symbol files, try to open/reopen the mapped file
131 that corresponds to the file from which we wish to read symbols. If the
132 objfile is to be mapped, we must malloc the structure itself using the
133 mmap version, and arrange that all memory allocation for the objfile uses
134 the mmap routines. If we are reusing an existing mapped file, from which
135 we get our objfile pointer, we have to make sure that we update the
136 pointers to the alloc/free functions in the obstack, in case these
137 functions have moved within the current gdb. */
139 fd = open_mapped_file (bfd_get_filename (abfd), bfd_get_mtime (abfd),
143 if (((mapto = map_to_address ()) == 0) ||
144 ((md = mmalloc_attach (fd, (void *) mapto)) == NULL))
148 else if ((objfile = (struct objfile *) mmalloc_getkey (md, 0)) != NULL)
150 /* Update memory corruption handler function addresses. */
153 objfile -> mmfd = fd;
154 /* Update pointers to functions to *our* copies */
155 obstack_chunkfun (&objfile -> psymbol_obstack, xmmalloc);
156 obstack_freefun (&objfile -> psymbol_obstack, mfree);
157 obstack_chunkfun (&objfile -> symbol_obstack, xmmalloc);
158 obstack_freefun (&objfile -> symbol_obstack, mfree);
159 obstack_chunkfun (&objfile -> type_obstack, xmmalloc);
160 obstack_freefun (&objfile -> type_obstack, mfree);
161 /* If already in objfile list, unlink it. */
162 unlink_objfile (objfile);
163 /* Forget things specific to a particular gdb, may have changed. */
164 objfile -> sf = NULL;
168 /* Set up to detect internal memory corruption. MUST be done before
169 the first malloc. See comments in init_malloc() and mmcheck(). */
171 objfile = (struct objfile *) xmmalloc (md, sizeof (struct objfile));
172 memset (objfile, 0, sizeof (struct objfile));
174 objfile -> mmfd = fd;
175 objfile -> flags |= OBJF_MAPPED;
176 mmalloc_setkey (objfile -> md, 0, objfile);
177 obstack_specify_allocation_with_arg (&objfile -> psymbol_obstack,
178 0, 0, xmmalloc, mfree,
180 obstack_specify_allocation_with_arg (&objfile -> symbol_obstack,
181 0, 0, xmmalloc, mfree,
183 obstack_specify_allocation_with_arg (&objfile -> type_obstack,
184 0, 0, xmmalloc, mfree,
189 if (mapped && (objfile == NULL))
191 warning ("symbol table for '%s' will not be mapped",
192 bfd_get_filename (abfd));
195 #else /* defined(NO_MMALLOC) || !defined(HAVE_MMAP) */
199 warning ("this version of gdb does not support mapped symbol tables.");
201 /* Turn off the global flag so we don't try to do mapped symbol tables
202 any more, which shuts up gdb unless the user specifically gives the
203 "mapped" keyword again. */
205 mapped_symbol_files = 0;
208 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
210 /* If we don't support mapped symbol files, didn't ask for the file to be
211 mapped, or failed to open the mapped file for some reason, then revert
212 back to an unmapped objfile. */
216 objfile = (struct objfile *) xmalloc (sizeof (struct objfile));
217 memset (objfile, 0, sizeof (struct objfile));
218 objfile -> md = NULL;
219 obstack_specify_allocation (&objfile -> psymbol_obstack, 0, 0, xmalloc,
221 obstack_specify_allocation (&objfile -> symbol_obstack, 0, 0, xmalloc,
223 obstack_specify_allocation (&objfile -> type_obstack, 0, 0, xmalloc,
227 /* Update the per-objfile information that comes from the bfd, ensuring
228 that any data that is reference is saved in the per-objfile data
231 objfile -> obfd = abfd;
232 if (objfile -> name != NULL)
234 mfree (objfile -> md, objfile -> name);
236 objfile -> name = mstrsave (objfile -> md, bfd_get_filename (abfd));
237 objfile -> mtime = bfd_get_mtime (abfd);
239 /* Build section table. */
241 if (build_objfile_section_table (objfile))
243 error ("Can't find the file sections in `%s': %s",
244 objfile -> name, bfd_errmsg (bfd_error));
247 /* Push this file onto the head of the linked list of other such files. */
249 objfile -> next = object_files;
250 object_files = objfile;
255 /* Unlink OBJFILE from the list of known objfiles, if it is found in the
258 It is not a bug, or error, to call this function if OBJFILE is not known
259 to be in the current list. This is done in the case of mapped objfiles,
260 for example, just to ensure that the mapped objfile doesn't appear twice
261 in the list. Since the list is threaded, linking in a mapped objfile
262 twice would create a circular list.
264 If OBJFILE turns out to be in the list, we zap it's NEXT pointer after
265 unlinking it, just to ensure that we have completely severed any linkages
266 between the OBJFILE and the list. */
269 unlink_objfile (objfile)
270 struct objfile *objfile;
272 struct objfile** objpp;
274 for (objpp = &object_files; *objpp != NULL; objpp = &((*objpp) -> next))
276 if (*objpp == objfile)
278 *objpp = (*objpp) -> next;
279 objfile -> next = NULL;
286 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
287 that as much as possible is allocated on the symbol_obstack and
288 psymbol_obstack, so that the memory can be efficiently freed.
290 Things which we do NOT free because they are not in malloc'd memory
291 or not in memory specific to the objfile include:
295 FIXME: If the objfile is using reusable symbol information (via mmalloc),
296 then we need to take into account the fact that more than one process
297 may be using the symbol information at the same time (when mmalloc is
298 extended to support cooperative locking). When more than one process
299 is using the mapped symbol info, we need to be more careful about when
300 we free objects in the reusable area. */
303 free_objfile (objfile)
304 struct objfile *objfile;
308 /* First do any symbol file specific actions required when we are
309 finished with a particular symbol file. Note that if the objfile
310 is using reusable symbol information (via mmalloc) then each of
311 these routines is responsible for doing the correct thing, either
312 freeing things which are valid only during this particular gdb
313 execution, or leaving them to be reused during the next one. */
315 if (objfile -> sf != NULL)
317 (*objfile -> sf -> sym_finish) (objfile);
320 /* We always close the bfd. */
322 if (objfile -> obfd != NULL)
324 char *name = bfd_get_filename (objfile->obfd);
325 bfd_close (objfile -> obfd);
329 /* Remove it from the chain of all objfiles. */
331 unlink_objfile (objfile);
333 /* Before the symbol table code was redone to make it easier to
334 selectively load and remove information particular to a specific
335 linkage unit, gdb used to do these things whenever the monolithic
336 symbol table was blown away. How much still needs to be done
337 is unknown, but we play it safe for now and keep each action until
338 it is shown to be no longer needed. */
340 #if defined (CLEAR_SOLIB)
343 clear_pc_function_cache ();
345 /* The last thing we do is free the objfile struct itself for the
346 non-reusable case, or detach from the mapped file for the reusable
347 case. Note that the mmalloc_detach or the mfree is the last thing
348 we can do with this objfile. */
350 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
352 if (objfile -> flags & OBJF_MAPPED)
354 /* Remember the fd so we can close it. We can't close it before
355 doing the detach, and after the detach the objfile is gone. */
356 mmfd = objfile -> mmfd;
357 mmalloc_detach (objfile -> md);
362 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
364 /* If we still have an objfile, then either we don't support reusable
365 objfiles or this one was not reusable. So free it normally. */
369 if (objfile -> name != NULL)
371 mfree (objfile -> md, objfile -> name);
373 if (objfile->global_psymbols.list)
374 mfree (objfile->md, objfile->global_psymbols.list);
375 if (objfile->static_psymbols.list)
376 mfree (objfile->md, objfile->static_psymbols.list);
377 /* Free the obstacks for non-reusable objfiles */
378 obstack_free (&objfile -> psymbol_obstack, 0);
379 obstack_free (&objfile -> symbol_obstack, 0);
380 obstack_free (&objfile -> type_obstack, 0);
381 mfree (objfile -> md, objfile);
387 /* Free all the object files at once and clean up their users. */
392 struct objfile *objfile, *temp;
394 ALL_OBJFILES_SAFE (objfile, temp)
396 free_objfile (objfile);
398 clear_symtab_users ();
401 /* Relocate OBJFILE to NEW_OFFSETS. There should be OBJFILE->NUM_SECTIONS
402 entries in new_offsets. */
404 objfile_relocate (objfile, new_offsets)
405 struct objfile *objfile;
406 struct section_offsets *new_offsets;
408 struct section_offsets *delta = (struct section_offsets *) alloca
409 (sizeof (struct section_offsets)
410 + objfile->num_sections * sizeof (delta->offsets));
414 int something_changed = 0;
415 for (i = 0; i < objfile->num_sections; ++i)
417 ANOFFSET (delta, i) =
418 ANOFFSET (new_offsets, i) - ANOFFSET (objfile->section_offsets, i);
419 if (ANOFFSET (delta, i) != 0)
420 something_changed = 1;
422 if (!something_changed)
426 /* OK, get all the symtabs. */
430 for (s = objfile->symtabs; s; s = s->next)
433 struct blockvector *bv;
436 /* First the line table. */
440 for (i = 0; i < l->nitems; ++i)
441 l->item[i].pc += ANOFFSET (delta, s->block_line_section);
444 /* Don't relocate a shared blockvector more than once. */
448 bv = BLOCKVECTOR (s);
449 for (i = 0; i < BLOCKVECTOR_NBLOCKS (bv); ++i)
454 b = BLOCKVECTOR_BLOCK (bv, i);
455 BLOCK_START (b) += ANOFFSET (delta, s->block_line_section);
456 BLOCK_END (b) += ANOFFSET (delta, s->block_line_section);
458 for (j = 0; j < BLOCK_NSYMS (b); ++j)
460 struct symbol *sym = BLOCK_SYM (b, j);
461 /* The RS6000 code from which this was taken skipped
462 any symbols in STRUCT_NAMESPACE or UNDEF_NAMESPACE.
463 But I'm leaving out that test, on the theory that
464 they can't possibly pass the tests below. */
465 if ((SYMBOL_CLASS (sym) == LOC_LABEL
466 || SYMBOL_CLASS (sym) == LOC_STATIC)
467 && SYMBOL_SECTION (sym) >= 0)
469 SYMBOL_VALUE_ADDRESS (sym) +=
470 ANOFFSET (delta, SYMBOL_SECTION (sym));
478 struct partial_symtab *p;
480 ALL_OBJFILE_PSYMTABS (objfile, p)
482 p->textlow += ANOFFSET (delta, SECT_OFF_TEXT);
483 p->texthigh += ANOFFSET (delta, SECT_OFF_TEXT);
488 struct partial_symbol *psym;
490 for (psym = objfile->global_psymbols.list;
491 psym < objfile->global_psymbols.next;
493 if (SYMBOL_SECTION (psym) >= 0)
494 SYMBOL_VALUE_ADDRESS (psym) += ANOFFSET (delta, SYMBOL_SECTION (psym));
495 for (psym = objfile->static_psymbols.list;
496 psym < objfile->static_psymbols.next;
498 if (SYMBOL_SECTION (psym) >= 0)
499 SYMBOL_VALUE_ADDRESS (psym) += ANOFFSET (delta, SYMBOL_SECTION (psym));
503 struct minimal_symbol *msym;
504 ALL_OBJFILE_MSYMBOLS (objfile, msym)
505 if (SYMBOL_SECTION (msym) >= 0)
506 SYMBOL_VALUE_ADDRESS (msym) += ANOFFSET (delta, SYMBOL_SECTION (msym));
511 for (i = 0; i < objfile->num_sections; ++i)
512 ANOFFSET (objfile->section_offsets, i) = ANOFFSET (new_offsets, i);
516 /* Many places in gdb want to test just to see if we have any partial
517 symbols available. This function returns zero if none are currently
518 available, nonzero otherwise. */
521 have_partial_symbols ()
527 if (ofp -> psymtabs != NULL)
535 /* Many places in gdb want to test just to see if we have any full
536 symbols available. This function returns zero if none are currently
537 available, nonzero otherwise. */
546 if (ofp -> symtabs != NULL)
554 /* Many places in gdb want to test just to see if we have any minimal
555 symbols available. This function returns zero if none are currently
556 available, nonzero otherwise. */
559 have_minimal_symbols ()
565 if (ofp -> msymbols != NULL)
573 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
575 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
576 of the corresponding symbol file in MTIME, try to open an existing file
577 with the name SYMSFILENAME and verify it is more recent than the base
578 file by checking it's timestamp against MTIME.
580 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
582 If SYMSFILENAME does exist, but is out of date, we check to see if the
583 user has specified creation of a mapped file. If so, we don't issue
584 any warning message because we will be creating a new mapped file anyway,
585 overwriting the old one. If not, then we issue a warning message so that
586 the user will know why we aren't using this existing mapped symbol file.
587 In either case, we return -1.
589 If SYMSFILENAME does exist and is not out of date, but can't be opened for
590 some reason, then prints an appropriate system error message and returns -1.
592 Otherwise, returns the open file descriptor. */
595 open_existing_mapped_file (symsfilename, mtime, mapped)
603 if (stat (symsfilename, &sbuf) == 0)
605 if (sbuf.st_mtime < mtime)
609 warning ("mapped symbol file `%s' is out of date, ignored it",
613 else if ((fd = open (symsfilename, O_RDWR)) < 0)
617 printf (error_pre_print);
619 print_sys_errmsg (symsfilename, errno);
625 /* Look for a mapped symbol file that corresponds to FILENAME and is more
626 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
627 use a mapped symbol file for this file, so create a new one if one does
630 If found, then return an open file descriptor for the file, otherwise
633 This routine is responsible for implementing the policy that generates
634 the name of the mapped symbol file from the name of a file containing
635 symbols that gdb would like to read. Currently this policy is to append
636 ".syms" to the name of the file.
638 This routine is also responsible for implementing the policy that
639 determines where the mapped symbol file is found (the search path).
640 This policy is that when reading an existing mapped file, a file of
641 the correct name in the current directory takes precedence over a
642 file of the correct name in the same directory as the symbol file.
643 When creating a new mapped file, it is always created in the current
644 directory. This helps to minimize the chances of a user unknowingly
645 creating big mapped files in places like /bin and /usr/local/bin, and
646 allows a local copy to override a manually installed global copy (in
647 /bin for example). */
650 open_mapped_file (filename, mtime, mapped)
658 /* First try to open an existing file in the current directory, and
659 then try the directory where the symbol file is located. */
661 symsfilename = concat ("./", basename (filename), ".syms", (char *) NULL);
662 if ((fd = open_existing_mapped_file (symsfilename, mtime, mapped)) < 0)
665 symsfilename = concat (filename, ".syms", (char *) NULL);
666 fd = open_existing_mapped_file (symsfilename, mtime, mapped);
669 /* If we don't have an open file by now, then either the file does not
670 already exist, or the base file has changed since it was created. In
671 either case, if the user has specified use of a mapped file, then
672 create a new mapped file, truncating any existing one. If we can't
673 create one, print a system error message saying why we can't.
675 By default the file is rw for everyone, with the user's umask taking
676 care of turning off the permissions the user wants off. */
678 if ((fd < 0) && mapped)
681 symsfilename = concat ("./", basename (filename), ".syms",
683 if ((fd = open (symsfilename, O_RDWR | O_CREAT | O_TRUNC, 0666)) < 0)
687 printf (error_pre_print);
689 print_sys_errmsg (symsfilename, errno);
697 /* Return the base address at which we would like the next objfile's
698 mapped data to start.
700 For now, we use the kludge that the configuration specifies a base
701 address to which it is safe to map the first mmalloc heap, and an
702 increment to add to this address for each successive heap. There are
703 a lot of issues to deal with here to make this work reasonably, including:
705 Avoid memory collisions with existing mapped address spaces
707 Reclaim address spaces when their mmalloc heaps are unmapped
709 When mmalloc heaps are shared between processes they have to be
710 mapped at the same addresses in each
712 Once created, a mmalloc heap that is to be mapped back in must be
713 mapped at the original address. I.E. each objfile will expect to
714 be remapped at it's original address. This becomes a problem if
715 the desired address is already in use.
726 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
728 static CORE_ADDR next = MMAP_BASE_ADDRESS;
729 CORE_ADDR mapto = next;
731 next += MMAP_INCREMENT;
742 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
744 /* Returns a section whose range includes PC or NULL if none found. */
750 struct obj_section *s;
751 struct objfile *objfile;
753 ALL_OBJFILES (objfile)
754 for (s = objfile->sections; s < objfile->sections_end; ++s)