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
);
116 /* Set up to detect internal memory corruption. MUST be done before
117 the first malloc. See comments in init_malloc() and mmcheck(). */
119 objfile
= (struct objfile
*) xmmalloc (md
, sizeof (struct objfile
));
120 (void) memset (objfile
, 0, sizeof (struct objfile
));
122 objfile
-> mmfd
= fd
;
123 objfile
-> flags
|= OBJF_MAPPED
;
124 mmalloc_setkey (objfile
-> md
, 0, objfile
);
125 obstack_full_begin (&objfile
-> psymbol_obstack
, 0, 0,
126 xmmalloc
, mfree
, objfile
-> md
,
127 OBSTACK_MMALLOC_LIKE
);
128 obstack_full_begin (&objfile
-> symbol_obstack
, 0, 0,
129 xmmalloc
, mfree
, objfile
-> md
,
130 OBSTACK_MMALLOC_LIKE
);
131 obstack_full_begin (&objfile
-> type_obstack
, 0, 0,
132 xmmalloc
, mfree
, objfile
-> md
,
133 OBSTACK_MMALLOC_LIKE
);
137 if (mapped
&& (objfile
== NULL
))
139 warning ("symbol table for '%s' will not be mapped",
140 bfd_get_filename (abfd
));
143 #else /* defined(NO_MMALLOC) || !defined(HAVE_MMAP) */
147 warning ("this version of gdb does not support mapped symbol tables.");
149 /* Turn off the global flag so we don't try to do mapped symbol tables
150 any more, which shuts up gdb unless the user specifically gives the
151 "mapped" keyword again. */
153 mapped_symbol_files
= 0;
156 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
158 /* If we don't support mapped symbol files, didn't ask for the file to be
159 mapped, or failed to open the mapped file for some reason, then revert
160 back to an unmapped objfile. */
164 objfile
= (struct objfile
*) xmalloc (sizeof (struct objfile
));
165 (void) memset (objfile
, 0, sizeof (struct objfile
));
166 objfile
-> md
= NULL
;
167 obstack_full_begin (&objfile
-> psymbol_obstack
, 0, 0, xmalloc
, free
,
169 obstack_full_begin (&objfile
-> symbol_obstack
, 0, 0, xmalloc
, free
,
171 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
;
197 /* Destroy an objfile and all the symtabs and psymtabs under it. Note
198 that as much as possible is allocated on the symbol_obstack and
199 psymbol_obstack, so that the memory can be efficiently freed.
201 Things which we do NOT free because they are not in malloc'd memory
202 or not in memory specific to the objfile include:
206 FIXME: If the objfile is using reusable symbol information (via mmalloc),
207 then we need to take into account the fact that more than one process
208 may be using the symbol information at the same time (when mmalloc is
209 extended to support cooperative locking). When more than one process
210 is using the mapped symbol info, we need to be more careful about when
211 we free objects in the reusable area. */
214 free_objfile (objfile
)
215 struct objfile
*objfile
;
220 /* First do any symbol file specific actions required when we are
221 finished with a particular symbol file. Note that if the objfile
222 is using reusable symbol information (via mmalloc) then each of
223 these routines is responsible for doing the correct thing, either
224 freeing things which are valid only during this particular gdb
225 execution, or leaving them to be reused during the next one. */
227 if (objfile
-> sf
!= NULL
)
229 (*objfile
-> sf
-> sym_finish
) (objfile
);
232 /* We always close the bfd. */
234 if (objfile
-> obfd
!= NULL
)
236 bfd_close (objfile
-> obfd
);
239 /* Remove it from the chain of all objfiles. */
241 if (object_files
== objfile
)
243 object_files
= objfile
-> next
;
247 for (ofp
= object_files
; ofp
; ofp
= ofp
-> next
)
249 if (ofp
-> next
== objfile
)
251 ofp
-> next
= objfile
-> next
;
256 objfile
-> next
= NULL
;
260 /* Before the symbol table code was redone to make it easier to
261 selectively load and remove information particular to a specific
262 linkage unit, gdb used to do these things whenever the monolithic
263 symbol table was blown away. How much still needs to be done
264 is unknown, but we play it safe for now and keep each action until
265 it is shown to be no longer needed. */
267 clear_symtab_users_once ();
268 #if defined (CLEAR_SOLIB)
271 clear_pc_function_cache ();
275 /* The last thing we do is free the objfile struct itself for the
276 non-reusable case, or detach from the mapped file for the reusable
277 case. Note that the mmalloc_detach or the mfree is the last thing
278 we can do with this objfile. */
280 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
282 if (objfile
-> flags
& OBJF_MAPPED
)
284 /* Remember the fd so we can close it. We can't close it before
285 doing the detach, and after the detach the objfile is gone. */
286 mmfd
= objfile
-> mmfd
;
287 mmalloc_detach (objfile
-> md
);
292 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */
294 /* If we still have an objfile, then either we don't support reusable
295 objfiles or this one was not reusable. So free it normally. */
299 if (objfile
-> name
!= NULL
)
301 mfree (objfile
-> md
, objfile
-> name
);
303 /* Free the obstacks for non-reusable objfiles */
304 obstack_free (&objfile
-> psymbol_obstack
, 0);
305 obstack_free (&objfile
-> symbol_obstack
, 0);
306 obstack_free (&objfile
-> type_obstack
, 0);
307 mfree (objfile
-> md
, objfile
);
313 /* Free all the object files at once. */
318 struct objfile
*objfile
, *temp
;
320 ALL_OBJFILES_SAFE (objfile
, temp
)
322 free_objfile (objfile
);
326 /* Many places in gdb want to test just to see if we have any partial
327 symbols available. This function returns zero if none are currently
328 available, nonzero otherwise. */
331 have_partial_symbols ()
337 if (ofp
-> psymtabs
!= NULL
)
345 /* Many places in gdb want to test just to see if we have any full
346 symbols available. This function returns zero if none are currently
347 available, nonzero otherwise. */
356 if (ofp
-> symtabs
!= NULL
)
364 /* Many places in gdb want to test just to see if we have any minimal
365 symbols available. This function returns zero if none are currently
366 available, nonzero otherwise. */
369 have_minimal_symbols ()
375 if (ofp
-> msymbols
!= NULL
)
383 #if !defined(NO_MMALLOC) && defined(HAVE_MMAP)
385 /* Given the name of a mapped symbol file in SYMSFILENAME, and the timestamp
386 of the corresponding symbol file in MTIME, try to open an existing file
387 with the name SYMSFILENAME and verify it is more recent than the base
388 file by checking it's timestamp against MTIME.
390 If SYMSFILENAME does not exist (or can't be stat'd), simply returns -1.
392 If SYMSFILENAME does exist, but is out of date, we check to see if the
393 user has specified creation of a mapped file. If so, we don't issue
394 any warning message because we will be creating a new mapped file anyway,
395 overwriting the old one. If not, then we issue a warning message so that
396 the user will know why we aren't using this existing mapped symbol file.
397 In either case, we return -1.
399 If SYMSFILENAME does exist and is not out of date, but can't be opened for
400 some reason, then prints an appropriate system error message and returns -1.
402 Otherwise, returns the open file descriptor. */
405 open_existing_mapped_file (symsfilename
, mtime
, mapped
)
413 if (stat (symsfilename
, &sbuf
) == 0)
415 if (sbuf
.st_mtime
< mtime
)
419 warning ("mapped symbol file `%s' is out of date", symsfilename
);
422 else if ((fd
= open (symsfilename
, O_RDWR
)) < 0)
426 printf (error_pre_print
);
428 print_sys_errmsg (symsfilename
, errno
);
434 /* Look for a mapped symbol file that corresponds to FILENAME and is more
435 recent than MTIME. If MAPPED is nonzero, the user has asked that gdb
436 use a mapped symbol file for this file, so create a new one if one does
439 If found, then return an open file descriptor for the file, otherwise
442 This routine is responsible for implementing the policy that generates
443 the name of the mapped symbol file from the name of a file containing
444 symbols that gdb would like to read. Currently this policy is to append
445 ".syms" to the name of the file.
447 This routine is also responsible for implementing the policy that
448 determines where the mapped symbol file is found (the search path).
449 This policy is that when reading an existing mapped file, a file of
450 the correct name in the current directory takes precedence over a
451 file of the correct name in the same directory as the symbol file.
452 When creating a new mapped file, it is always created in the current
453 directory. This helps to minimize the chances of a user unknowingly
454 creating big mapped files in places like /bin and /usr/local/bin, and
455 allows a local copy to override a manually installed global copy (in
456 /bin for example). */
459 open_mapped_file (filename
, mtime
, mapped
)
467 /* First try to open an existing file in the current directory, and
468 then try the directory where the symbol file is located. */
470 symsfilename
= concat ("./", basename (filename
), ".syms", (char *) NULL
);
471 if ((fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
)) < 0)
474 symsfilename
= concat (filename
, ".syms", (char *) NULL
);
475 fd
= open_existing_mapped_file (symsfilename
, mtime
, mapped
);
478 /* If we don't have an open file by now, then either the file does not
479 already exist, or the base file has changed since it was created. In
480 either case, if the user has specified use of a mapped file, then
481 create a new mapped file, truncating any existing one. If we can't
482 create one, print a system error message saying why we can't.
484 By default the file is rw for everyone, with the user's umask taking
485 care of turning off the permissions the user wants off. */
487 if ((fd
< 0) && mapped
)
490 symsfilename
= concat ("./", basename (filename
), ".syms",
492 if ((fd
= open (symsfilename
, O_RDWR
| O_CREAT
| O_TRUNC
, 0666)) < 0)
496 printf (error_pre_print
);
498 print_sys_errmsg (symsfilename
, errno
);
506 /* Return the base address at which we would like the next objfile's
507 mapped data to start.
509 For now, we use the kludge that the configuration specifies a base
510 address to which it is safe to map the first mmalloc heap, and an
511 increment to add to this address for each successive heap. There are
512 a lot of issues to deal with here to make this work reasonably, including:
514 Avoid memory collisions with existing mapped address spaces
516 Reclaim address spaces when their mmalloc heaps are unmapped
518 When mmalloc heaps are shared between processes they have to be
519 mapped at the same addresses in each
521 Once created, a mmalloc heap that is to be mapped back in must be
522 mapped at the original address. I.E. each objfile will expect to
523 be remapped at it's original address. This becomes a problem if
524 the desired address is already in use.
535 #if defined(MMAP_BASE_ADDRESS) && defined (MMAP_INCREMENT)
537 static CORE_ADDR next
= MMAP_BASE_ADDRESS
;
538 CORE_ADDR mapto
= next
;
540 next
+= MMAP_INCREMENT
;
551 #endif /* !defined(NO_MMALLOC) && defined(HAVE_MMAP) */