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1 /* Handle shared libraries for GDB, the GNU Debugger.
2
3 Copyright (C) 1990-2021 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
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 3 of the License, or
10 (at your option) any later version.
11
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.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19
20 #include "defs.h"
21
22 #include <sys/types.h>
23 #include <fcntl.h>
24 #include "symtab.h"
25 #include "bfd.h"
26 #include "symfile.h"
27 #include "objfiles.h"
28 #include "gdbcore.h"
29 #include "command.h"
30 #include "target.h"
31 #include "frame.h"
32 #include "gdb_regex.h"
33 #include "inferior.h"
34 #include "gdbsupport/environ.h"
35 #include "language.h"
36 #include "gdbcmd.h"
37 #include "completer.h"
38 #include "filenames.h" /* for DOSish file names */
39 #include "exec.h"
40 #include "solist.h"
41 #include "observable.h"
42 #include "readline/tilde.h"
43 #include "remote.h"
44 #include "solib.h"
45 #include "interps.h"
46 #include "filesystem.h"
47 #include "gdb_bfd.h"
48 #include "gdbsupport/filestuff.h"
49 #include "source.h"
50 #include "cli/cli-style.h"
51
52 /* Architecture-specific operations. */
53
54 /* Per-architecture data key. */
55 static struct gdbarch_data *solib_data;
56
57 static void *
58 solib_init (struct obstack *obstack)
59 {
60 struct target_so_ops **ops;
61
62 ops = OBSTACK_ZALLOC (obstack, struct target_so_ops *);
63 *ops = current_target_so_ops;
64 return ops;
65 }
66
67 static const struct target_so_ops *
68 solib_ops (struct gdbarch *gdbarch)
69 {
70 const struct target_so_ops **ops
71 = (const struct target_so_ops **) gdbarch_data (gdbarch, solib_data);
72
73 return *ops;
74 }
75
76 /* Set the solib operations for GDBARCH to NEW_OPS. */
77
78 void
79 set_solib_ops (struct gdbarch *gdbarch, const struct target_so_ops *new_ops)
80 {
81 const struct target_so_ops **ops
82 = (const struct target_so_ops **) gdbarch_data (gdbarch, solib_data);
83
84 *ops = new_ops;
85 }
86 \f
87
88 /* external data declarations */
89
90 /* FIXME: gdbarch needs to control this variable, or else every
91 configuration needs to call set_solib_ops. */
92 struct target_so_ops *current_target_so_ops;
93
94 /* Local function prototypes */
95
96 /* If non-empty, this is a search path for loading non-absolute shared library
97 symbol files. This takes precedence over the environment variables PATH
98 and LD_LIBRARY_PATH. */
99 static char *solib_search_path = NULL;
100 static void
101 show_solib_search_path (struct ui_file *file, int from_tty,
102 struct cmd_list_element *c, const char *value)
103 {
104 fprintf_filtered (file, _("The search path for loading non-absolute "
105 "shared library symbol files is %s.\n"),
106 value);
107 }
108
109 /* Same as HAVE_DOS_BASED_FILE_SYSTEM, but useable as an rvalue. */
110 #if (HAVE_DOS_BASED_FILE_SYSTEM)
111 # define DOS_BASED_FILE_SYSTEM 1
112 #else
113 # define DOS_BASED_FILE_SYSTEM 0
114 #endif
115
116 /* Return the full pathname of a binary file (the main executable or a
117 shared library file), or NULL if not found. If FD is non-NULL, *FD
118 is set to either -1 or an open file handle for the binary file.
119
120 Global variable GDB_SYSROOT is used as a prefix directory
121 to search for binary files if they have an absolute path.
122 If GDB_SYSROOT starts with "target:" and target filesystem
123 is the local filesystem then the "target:" prefix will be
124 stripped before the search starts. This ensures that the
125 same search algorithm is used for local files regardless of
126 whether a "target:" prefix was used.
127
128 Global variable SOLIB_SEARCH_PATH is used as a prefix directory
129 (or set of directories, as in LD_LIBRARY_PATH) to search for all
130 shared libraries if not found in either the sysroot (if set) or
131 the local filesystem. SOLIB_SEARCH_PATH is not used when searching
132 for the main executable.
133
134 Search algorithm:
135 * If a sysroot is set and path is absolute:
136 * Search for sysroot/path.
137 * else
138 * Look for it literally (unmodified).
139 * If IS_SOLIB is non-zero:
140 * Look in SOLIB_SEARCH_PATH.
141 * If available, use target defined search function.
142 * If NO sysroot is set, perform the following two searches:
143 * Look in inferior's $PATH.
144 * If IS_SOLIB is non-zero:
145 * Look in inferior's $LD_LIBRARY_PATH.
146 *
147 * The last check avoids doing this search when targeting remote
148 * machines since a sysroot will almost always be set.
149 */
150
151 static gdb::unique_xmalloc_ptr<char>
152 solib_find_1 (const char *in_pathname, int *fd, bool is_solib)
153 {
154 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
155 int found_file = -1;
156 gdb::unique_xmalloc_ptr<char> temp_pathname;
157 const char *fskind = effective_target_file_system_kind ();
158 const char *sysroot = gdb_sysroot;
159 int prefix_len, orig_prefix_len;
160
161 /* If the absolute prefix starts with "target:" but the filesystem
162 accessed by the target_fileio_* methods is the local filesystem
163 then we strip the "target:" prefix now and work with the local
164 filesystem. This ensures that the same search algorithm is used
165 for all local files regardless of whether a "target:" prefix was
166 used. */
167 if (is_target_filename (sysroot) && target_filesystem_is_local ())
168 sysroot += strlen (TARGET_SYSROOT_PREFIX);
169
170 /* Strip any trailing slashes from the absolute prefix. */
171 prefix_len = orig_prefix_len = strlen (sysroot);
172
173 while (prefix_len > 0 && IS_DIR_SEPARATOR (sysroot[prefix_len - 1]))
174 prefix_len--;
175
176 std::string sysroot_holder;
177 if (prefix_len == 0)
178 sysroot = NULL;
179 else if (prefix_len != orig_prefix_len)
180 {
181 sysroot_holder = std::string (sysroot, prefix_len);
182 sysroot = sysroot_holder.c_str ();
183 }
184
185 /* If we're on a non-DOS-based system, backslashes won't be
186 understood as directory separator, so, convert them to forward
187 slashes, iff we're supposed to handle DOS-based file system
188 semantics for target paths. */
189 if (!DOS_BASED_FILE_SYSTEM && fskind == file_system_kind_dos_based)
190 {
191 char *p;
192
193 /* Avoid clobbering our input. */
194 p = (char *) alloca (strlen (in_pathname) + 1);
195 strcpy (p, in_pathname);
196 in_pathname = p;
197
198 for (; *p; p++)
199 {
200 if (*p == '\\')
201 *p = '/';
202 }
203 }
204
205 /* Note, we're interested in IS_TARGET_ABSOLUTE_PATH, not
206 IS_ABSOLUTE_PATH. The latter is for host paths only, while
207 IN_PATHNAME is a target path. For example, if we're supposed to
208 be handling DOS-like semantics we want to consider a
209 'c:/foo/bar.dll' path as an absolute path, even on a Unix box.
210 With such a path, before giving up on the sysroot, we'll try:
211
212 1st attempt, c:/foo/bar.dll ==> /sysroot/c:/foo/bar.dll
213 2nd attempt, c:/foo/bar.dll ==> /sysroot/c/foo/bar.dll
214 3rd attempt, c:/foo/bar.dll ==> /sysroot/foo/bar.dll
215 */
216
217 if (!IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname) || sysroot == NULL)
218 temp_pathname.reset (xstrdup (in_pathname));
219 else
220 {
221 bool need_dir_separator;
222
223 /* Concatenate the sysroot and the target reported filename. We
224 may need to glue them with a directory separator. Cases to
225 consider:
226
227 | sysroot | separator | in_pathname |
228 |-----------------+-----------+----------------|
229 | /some/dir | / | c:/foo/bar.dll |
230 | /some/dir | | /foo/bar.dll |
231 | target: | | c:/foo/bar.dll |
232 | target: | | /foo/bar.dll |
233 | target:some/dir | / | c:/foo/bar.dll |
234 | target:some/dir | | /foo/bar.dll |
235
236 IOW, we don't need to add a separator if IN_PATHNAME already
237 has one, or when the sysroot is exactly "target:".
238 There's no need to check for drive spec explicitly, as we only
239 get here if IN_PATHNAME is considered an absolute path. */
240 need_dir_separator = !(IS_DIR_SEPARATOR (in_pathname[0])
241 || strcmp (TARGET_SYSROOT_PREFIX, sysroot) == 0);
242
243 /* Cat the prefixed pathname together. */
244 temp_pathname.reset (concat (sysroot,
245 need_dir_separator ? SLASH_STRING : "",
246 in_pathname, (char *) NULL));
247 }
248
249 /* Handle files to be accessed via the target. */
250 if (is_target_filename (temp_pathname.get ()))
251 {
252 if (fd != NULL)
253 *fd = -1;
254 return temp_pathname;
255 }
256
257 /* Now see if we can open it. */
258 found_file = gdb_open_cloexec (temp_pathname.get (), O_RDONLY | O_BINARY, 0);
259
260 /* If the search in gdb_sysroot failed, and the path name has a
261 drive spec (e.g, c:/foo), try stripping ':' from the drive spec,
262 and retrying in the sysroot:
263 c:/foo/bar.dll ==> /sysroot/c/foo/bar.dll. */
264
265 if (found_file < 0
266 && sysroot != NULL
267 && HAS_TARGET_DRIVE_SPEC (fskind, in_pathname))
268 {
269 bool need_dir_separator = !IS_DIR_SEPARATOR (in_pathname[2]);
270 char drive[2] = { in_pathname[0], '\0' };
271
272 temp_pathname.reset (concat (sysroot,
273 SLASH_STRING,
274 drive,
275 need_dir_separator ? SLASH_STRING : "",
276 in_pathname + 2, (char *) NULL));
277
278 found_file = gdb_open_cloexec (temp_pathname.get (),
279 O_RDONLY | O_BINARY, 0);
280 if (found_file < 0)
281 {
282 /* If the search in gdb_sysroot still failed, try fully
283 stripping the drive spec, and trying once more in the
284 sysroot before giving up.
285
286 c:/foo/bar.dll ==> /sysroot/foo/bar.dll. */
287
288 temp_pathname.reset (concat (sysroot,
289 need_dir_separator ? SLASH_STRING : "",
290 in_pathname + 2, (char *) NULL));
291
292 found_file = gdb_open_cloexec (temp_pathname.get (),
293 O_RDONLY | O_BINARY, 0);
294 }
295 }
296
297 /* We try to find the library in various ways. After each attempt,
298 either found_file >= 0 and temp_pathname is a malloc'd string, or
299 found_file < 0 and temp_pathname does not point to storage that
300 needs to be freed. */
301
302 if (found_file < 0)
303 temp_pathname.reset (NULL);
304
305 /* If the search in gdb_sysroot failed, and the path name is
306 absolute at this point, make it relative. (openp will try and open the
307 file according to its absolute path otherwise, which is not what we want.)
308 Affects subsequent searches for this solib. */
309 if (found_file < 0 && IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname))
310 {
311 /* First, get rid of any drive letters etc. */
312 while (!IS_TARGET_DIR_SEPARATOR (fskind, *in_pathname))
313 in_pathname++;
314
315 /* Next, get rid of all leading dir separators. */
316 while (IS_TARGET_DIR_SEPARATOR (fskind, *in_pathname))
317 in_pathname++;
318 }
319
320 /* If not found, and we're looking for a solib, search the
321 solib_search_path (if any). */
322 if (is_solib && found_file < 0 && solib_search_path != NULL)
323 found_file = openp (solib_search_path,
324 OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH,
325 in_pathname, O_RDONLY | O_BINARY, &temp_pathname);
326
327 /* If not found, and we're looking for a solib, next search the
328 solib_search_path (if any) for the basename only (ignoring the
329 path). This is to allow reading solibs from a path that differs
330 from the opened path. */
331 if (is_solib && found_file < 0 && solib_search_path != NULL)
332 found_file = openp (solib_search_path,
333 OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH,
334 target_lbasename (fskind, in_pathname),
335 O_RDONLY | O_BINARY, &temp_pathname);
336
337 /* If not found, and we're looking for a solib, try to use target
338 supplied solib search method. */
339 if (is_solib && found_file < 0 && ops->find_and_open_solib)
340 found_file = ops->find_and_open_solib (in_pathname, O_RDONLY | O_BINARY,
341 &temp_pathname);
342
343 /* If not found, next search the inferior's $PATH environment variable. */
344 if (found_file < 0 && sysroot == NULL)
345 found_file = openp (current_inferior ()->environment.get ("PATH"),
346 OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
347 O_RDONLY | O_BINARY, &temp_pathname);
348
349 /* If not found, and we're looking for a solib, next search the
350 inferior's $LD_LIBRARY_PATH environment variable. */
351 if (is_solib && found_file < 0 && sysroot == NULL)
352 found_file = openp (current_inferior ()->environment.get
353 ("LD_LIBRARY_PATH"),
354 OPF_TRY_CWD_FIRST | OPF_RETURN_REALPATH, in_pathname,
355 O_RDONLY | O_BINARY, &temp_pathname);
356
357 if (fd == NULL)
358 {
359 if (found_file >= 0)
360 close (found_file);
361 }
362 else
363 *fd = found_file;
364
365 return temp_pathname;
366 }
367
368 /* Return the full pathname of the main executable, or NULL if not
369 found. If FD is non-NULL, *FD is set to either -1 or an open file
370 handle for the main executable. */
371
372 gdb::unique_xmalloc_ptr<char>
373 exec_file_find (const char *in_pathname, int *fd)
374 {
375 gdb::unique_xmalloc_ptr<char> result;
376 const char *fskind = effective_target_file_system_kind ();
377
378 if (in_pathname == NULL)
379 return NULL;
380
381 if (*gdb_sysroot != '\0' && IS_TARGET_ABSOLUTE_PATH (fskind, in_pathname))
382 {
383 result = solib_find_1 (in_pathname, fd, false);
384
385 if (result == NULL && fskind == file_system_kind_dos_based)
386 {
387 char *new_pathname;
388
389 new_pathname = (char *) alloca (strlen (in_pathname) + 5);
390 strcpy (new_pathname, in_pathname);
391 strcat (new_pathname, ".exe");
392
393 result = solib_find_1 (new_pathname, fd, false);
394 }
395 }
396 else
397 {
398 /* It's possible we don't have a full path, but rather just a
399 filename. Some targets, such as HP-UX, don't provide the
400 full path, sigh.
401
402 Attempt to qualify the filename against the source path.
403 (If that fails, we'll just fall back on the original
404 filename. Not much more we can do...) */
405
406 if (!source_full_path_of (in_pathname, &result))
407 result.reset (xstrdup (in_pathname));
408 if (fd != NULL)
409 *fd = -1;
410 }
411
412 return result;
413 }
414
415 /* Return the full pathname of a shared library file, or NULL if not
416 found. If FD is non-NULL, *FD is set to either -1 or an open file
417 handle for the shared library.
418
419 The search algorithm used is described in solib_find_1's comment
420 above. */
421
422 gdb::unique_xmalloc_ptr<char>
423 solib_find (const char *in_pathname, int *fd)
424 {
425 const char *solib_symbols_extension
426 = gdbarch_solib_symbols_extension (target_gdbarch ());
427
428 /* If solib_symbols_extension is set, replace the file's
429 extension. */
430 if (solib_symbols_extension != NULL)
431 {
432 const char *p = in_pathname + strlen (in_pathname);
433
434 while (p > in_pathname && *p != '.')
435 p--;
436
437 if (*p == '.')
438 {
439 char *new_pathname;
440
441 new_pathname
442 = (char *) alloca (p - in_pathname + 1
443 + strlen (solib_symbols_extension) + 1);
444 memcpy (new_pathname, in_pathname, p - in_pathname + 1);
445 strcpy (new_pathname + (p - in_pathname) + 1,
446 solib_symbols_extension);
447
448 in_pathname = new_pathname;
449 }
450 }
451
452 return solib_find_1 (in_pathname, fd, true);
453 }
454
455 /* Open and return a BFD for the shared library PATHNAME. If FD is not -1,
456 it is used as file handle to open the file. Throws an error if the file
457 could not be opened. Handles both local and remote file access.
458
459 If unsuccessful, the FD will be closed (unless FD was -1). */
460
461 gdb_bfd_ref_ptr
462 solib_bfd_fopen (const char *pathname, int fd)
463 {
464 gdb_bfd_ref_ptr abfd (gdb_bfd_open (pathname, gnutarget, fd));
465
466 if (abfd != NULL && !gdb_bfd_has_target_filename (abfd.get ()))
467 bfd_set_cacheable (abfd.get (), 1);
468
469 if (abfd == NULL)
470 {
471 /* Arrange to free PATHNAME when the error is thrown. */
472 error (_("Could not open `%s' as an executable file: %s"),
473 pathname, bfd_errmsg (bfd_get_error ()));
474 }
475
476 return abfd;
477 }
478
479 /* Find shared library PATHNAME and open a BFD for it. */
480
481 gdb_bfd_ref_ptr
482 solib_bfd_open (const char *pathname)
483 {
484 int found_file;
485 const struct bfd_arch_info *b;
486
487 /* Search for shared library file. */
488 gdb::unique_xmalloc_ptr<char> found_pathname
489 = solib_find (pathname, &found_file);
490 if (found_pathname == NULL)
491 {
492 /* Return failure if the file could not be found, so that we can
493 accumulate messages about missing libraries. */
494 if (errno == ENOENT)
495 return NULL;
496
497 perror_with_name (pathname);
498 }
499
500 /* Open bfd for shared library. */
501 gdb_bfd_ref_ptr abfd (solib_bfd_fopen (found_pathname.get (), found_file));
502
503 /* Check bfd format. */
504 if (!bfd_check_format (abfd.get (), bfd_object))
505 error (_("`%s': not in executable format: %s"),
506 bfd_get_filename (abfd.get ()), bfd_errmsg (bfd_get_error ()));
507
508 /* Check bfd arch. */
509 b = gdbarch_bfd_arch_info (target_gdbarch ());
510 if (!b->compatible (b, bfd_get_arch_info (abfd.get ())))
511 warning (_("`%s': Shared library architecture %s is not compatible "
512 "with target architecture %s."), bfd_get_filename (abfd.get ()),
513 bfd_get_arch_info (abfd.get ())->printable_name,
514 b->printable_name);
515
516 return abfd;
517 }
518
519 /* Given a pointer to one of the shared objects in our list of mapped
520 objects, use the recorded name to open a bfd descriptor for the
521 object, build a section table, relocate all the section addresses
522 by the base address at which the shared object was mapped, and then
523 add the sections to the target's section table.
524
525 FIXME: In most (all?) cases the shared object file name recorded in
526 the dynamic linkage tables will be a fully qualified pathname. For
527 cases where it isn't, do we really mimic the systems search
528 mechanism correctly in the below code (particularly the tilde
529 expansion stuff?). */
530
531 static int
532 solib_map_sections (struct so_list *so)
533 {
534 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
535
536 gdb::unique_xmalloc_ptr<char> filename (tilde_expand (so->so_name));
537 gdb_bfd_ref_ptr abfd (ops->bfd_open (filename.get ()));
538
539 if (abfd == NULL)
540 return 0;
541
542 /* Leave bfd open, core_xfer_memory and "info files" need it. */
543 so->abfd = abfd.release ();
544
545 /* Copy the full path name into so_name, allowing symbol_file_add
546 to find it later. This also affects the =library-loaded GDB/MI
547 event, and in particular the part of that notification providing
548 the library's host-side path. If we let the target dictate
549 that objfile's path, and the target is different from the host,
550 GDB/MI will not provide the correct host-side path. */
551 if (strlen (bfd_get_filename (so->abfd)) >= SO_NAME_MAX_PATH_SIZE)
552 error (_("Shared library file name is too long."));
553 strcpy (so->so_name, bfd_get_filename (so->abfd));
554
555 if (so->sections == nullptr)
556 so->sections = new target_section_table;
557 *so->sections = build_section_table (so->abfd);
558
559 for (target_section &p : *so->sections)
560 {
561 /* Relocate the section binding addresses as recorded in the shared
562 object's file by the base address to which the object was actually
563 mapped. */
564 ops->relocate_section_addresses (so, &p);
565
566 /* If the target didn't provide information about the address
567 range of the shared object, assume we want the location of
568 the .text section. */
569 if (so->addr_low == 0 && so->addr_high == 0
570 && strcmp (p.the_bfd_section->name, ".text") == 0)
571 {
572 so->addr_low = p.addr;
573 so->addr_high = p.endaddr;
574 }
575 }
576
577 /* Add the shared object's sections to the current set of file
578 section tables. Do this immediately after mapping the object so
579 that later nodes in the list can query this object, as is needed
580 in solib-osf.c. */
581 current_program_space->add_target_sections (so, *so->sections);
582
583 return 1;
584 }
585
586 /* Free symbol-file related contents of SO and reset for possible reloading
587 of SO. If we have opened a BFD for SO, close it. If we have placed SO's
588 sections in some target's section table, the caller is responsible for
589 removing them.
590
591 This function doesn't mess with objfiles at all. If there is an
592 objfile associated with SO that needs to be removed, the caller is
593 responsible for taking care of that. */
594
595 static void
596 clear_so (struct so_list *so)
597 {
598 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
599
600 delete so->sections;
601 so->sections = NULL;
602
603 gdb_bfd_unref (so->abfd);
604 so->abfd = NULL;
605
606 /* Our caller closed the objfile, possibly via objfile_purge_solibs. */
607 so->symbols_loaded = 0;
608 so->objfile = NULL;
609
610 so->addr_low = so->addr_high = 0;
611
612 /* Restore the target-supplied file name. SO_NAME may be the path
613 of the symbol file. */
614 strcpy (so->so_name, so->so_original_name);
615
616 /* Do the same for target-specific data. */
617 if (ops->clear_so != NULL)
618 ops->clear_so (so);
619 }
620
621 /* Free the storage associated with the `struct so_list' object SO.
622 If we have opened a BFD for SO, close it.
623
624 The caller is responsible for removing SO from whatever list it is
625 a member of. If we have placed SO's sections in some target's
626 section table, the caller is responsible for removing them.
627
628 This function doesn't mess with objfiles at all. If there is an
629 objfile associated with SO that needs to be removed, the caller is
630 responsible for taking care of that. */
631
632 void
633 free_so (struct so_list *so)
634 {
635 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
636
637 clear_so (so);
638 ops->free_so (so);
639
640 xfree (so);
641 }
642
643
644 /* Read in symbols for shared object SO. If SYMFILE_VERBOSE is set in FLAGS,
645 be chatty about it. Return true if any symbols were actually loaded. */
646
647 bool
648 solib_read_symbols (struct so_list *so, symfile_add_flags flags)
649 {
650 if (so->symbols_loaded)
651 {
652 /* If needed, we've already warned in our caller. */
653 }
654 else if (so->abfd == NULL)
655 {
656 /* We've already warned about this library, when trying to open
657 it. */
658 }
659 else
660 {
661
662 flags |= current_inferior ()->symfile_flags;
663
664 try
665 {
666 /* Have we already loaded this shared object? */
667 so->objfile = nullptr;
668 for (objfile *objfile : current_program_space->objfiles ())
669 {
670 if (filename_cmp (objfile_name (objfile), so->so_name) == 0
671 && objfile->addr_low == so->addr_low)
672 {
673 so->objfile = objfile;
674 break;
675 }
676 }
677 if (so->objfile == NULL)
678 {
679 section_addr_info sap
680 = build_section_addr_info_from_section_table (*so->sections);
681 so->objfile = symbol_file_add_from_bfd (so->abfd, so->so_name,
682 flags, &sap,
683 OBJF_SHARED, NULL);
684 so->objfile->addr_low = so->addr_low;
685 }
686
687 so->symbols_loaded = 1;
688 }
689 catch (const gdb_exception_error &e)
690 {
691 exception_fprintf (gdb_stderr, e, _("Error while reading shared"
692 " library symbols for %s:\n"),
693 so->so_name);
694 }
695
696 return true;
697 }
698
699 return false;
700 }
701
702 /* Return true if KNOWN->objfile is used by any other so_list object
703 in the list of shared libraries. Return false otherwise. */
704
705 static bool
706 solib_used (const struct so_list *const known)
707 {
708 for (const struct so_list *pivot : current_program_space->solibs ())
709 if (pivot != known && pivot->objfile == known->objfile)
710 return true;
711 return false;
712 }
713
714 /* See solib.h. */
715
716 void
717 update_solib_list (int from_tty)
718 {
719 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
720 struct so_list *inferior = ops->current_sos();
721 struct so_list *gdb, **gdb_link;
722
723 /* We can reach here due to changing solib-search-path or the
724 sysroot, before having any inferior. */
725 if (target_has_execution () && inferior_ptid != null_ptid)
726 {
727 struct inferior *inf = current_inferior ();
728
729 /* If we are attaching to a running process for which we
730 have not opened a symbol file, we may be able to get its
731 symbols now! */
732 if (inf->attach_flag
733 && current_program_space->symfile_object_file == NULL)
734 {
735 try
736 {
737 ops->open_symbol_file_object (from_tty);
738 }
739 catch (const gdb_exception &ex)
740 {
741 exception_fprintf (gdb_stderr, ex,
742 "Error reading attached "
743 "process's symbol file.\n");
744 }
745 }
746 }
747
748 /* GDB and the inferior's dynamic linker each maintain their own
749 list of currently loaded shared objects; we want to bring the
750 former in sync with the latter. Scan both lists, seeing which
751 shared objects appear where. There are three cases:
752
753 - A shared object appears on both lists. This means that GDB
754 knows about it already, and it's still loaded in the inferior.
755 Nothing needs to happen.
756
757 - A shared object appears only on GDB's list. This means that
758 the inferior has unloaded it. We should remove the shared
759 object from GDB's tables.
760
761 - A shared object appears only on the inferior's list. This
762 means that it's just been loaded. We should add it to GDB's
763 tables.
764
765 So we walk GDB's list, checking each entry to see if it appears
766 in the inferior's list too. If it does, no action is needed, and
767 we remove it from the inferior's list. If it doesn't, the
768 inferior has unloaded it, and we remove it from GDB's list. By
769 the time we're done walking GDB's list, the inferior's list
770 contains only the new shared objects, which we then add. */
771
772 gdb = current_program_space->so_list;
773 gdb_link = &current_program_space->so_list;
774 while (gdb)
775 {
776 struct so_list *i = inferior;
777 struct so_list **i_link = &inferior;
778
779 /* Check to see whether the shared object *gdb also appears in
780 the inferior's current list. */
781 while (i)
782 {
783 if (ops->same)
784 {
785 if (ops->same (gdb, i))
786 break;
787 }
788 else
789 {
790 if (! filename_cmp (gdb->so_original_name, i->so_original_name))
791 break;
792 }
793
794 i_link = &i->next;
795 i = *i_link;
796 }
797
798 /* If the shared object appears on the inferior's list too, then
799 it's still loaded, so we don't need to do anything. Delete
800 it from the inferior's list, and leave it on GDB's list. */
801 if (i)
802 {
803 *i_link = i->next;
804 free_so (i);
805 gdb_link = &gdb->next;
806 gdb = *gdb_link;
807 }
808
809 /* If it's not on the inferior's list, remove it from GDB's tables. */
810 else
811 {
812 /* Notify any observer that the shared object has been
813 unloaded before we remove it from GDB's tables. */
814 gdb::observers::solib_unloaded.notify (gdb);
815
816 current_program_space->deleted_solibs.push_back (gdb->so_name);
817
818 *gdb_link = gdb->next;
819
820 /* Unless the user loaded it explicitly, free SO's objfile. */
821 if (gdb->objfile && ! (gdb->objfile->flags & OBJF_USERLOADED)
822 && !solib_used (gdb))
823 gdb->objfile->unlink ();
824
825 /* Some targets' section tables might be referring to
826 sections from so->abfd; remove them. */
827 current_program_space->remove_target_sections (gdb);
828
829 free_so (gdb);
830 gdb = *gdb_link;
831 }
832 }
833
834 /* Now the inferior's list contains only shared objects that don't
835 appear in GDB's list --- those that are newly loaded. Add them
836 to GDB's shared object list. */
837 if (inferior)
838 {
839 int not_found = 0;
840 const char *not_found_filename = NULL;
841
842 struct so_list *i;
843
844 /* Add the new shared objects to GDB's list. */
845 *gdb_link = inferior;
846
847 /* Fill in the rest of each of the `struct so_list' nodes. */
848 for (i = inferior; i; i = i->next)
849 {
850
851 i->pspace = current_program_space;
852 current_program_space->added_solibs.push_back (i);
853
854 try
855 {
856 /* Fill in the rest of the `struct so_list' node. */
857 if (!solib_map_sections (i))
858 {
859 not_found++;
860 if (not_found_filename == NULL)
861 not_found_filename = i->so_original_name;
862 }
863 }
864
865 catch (const gdb_exception_error &e)
866 {
867 exception_fprintf (gdb_stderr, e,
868 _("Error while mapping shared "
869 "library sections:\n"));
870 }
871
872 /* Notify any observer that the shared object has been
873 loaded now that we've added it to GDB's tables. */
874 gdb::observers::solib_loaded.notify (i);
875 }
876
877 /* If a library was not found, issue an appropriate warning
878 message. We have to use a single call to warning in case the
879 front end does something special with warnings, e.g., pop up
880 a dialog box. It Would Be Nice if we could get a "warning: "
881 prefix on each line in the CLI front end, though - it doesn't
882 stand out well. */
883
884 if (not_found == 1)
885 warning (_("Could not load shared library symbols for %s.\n"
886 "Do you need \"set solib-search-path\" "
887 "or \"set sysroot\"?"),
888 not_found_filename);
889 else if (not_found > 1)
890 warning (_("\
891 Could not load shared library symbols for %d libraries, e.g. %s.\n\
892 Use the \"info sharedlibrary\" command to see the complete listing.\n\
893 Do you need \"set solib-search-path\" or \"set sysroot\"?"),
894 not_found, not_found_filename);
895 }
896 }
897
898
899 /* Return non-zero if NAME is the libpthread shared library.
900
901 Uses a fairly simplistic heuristic approach where we check
902 the file name against "/libpthread". This can lead to false
903 positives, but this should be good enough in practice. */
904
905 bool
906 libpthread_name_p (const char *name)
907 {
908 return (strstr (name, "/libpthread") != NULL);
909 }
910
911 /* Return non-zero if SO is the libpthread shared library. */
912
913 static bool
914 libpthread_solib_p (struct so_list *so)
915 {
916 return libpthread_name_p (so->so_name);
917 }
918
919 /* Read in symbolic information for any shared objects whose names
920 match PATTERN. (If we've already read a shared object's symbol
921 info, leave it alone.) If PATTERN is zero, read them all.
922
923 If READSYMS is 0, defer reading symbolic information until later
924 but still do any needed low level processing.
925
926 FROM_TTY is described for update_solib_list, above. */
927
928 void
929 solib_add (const char *pattern, int from_tty, int readsyms)
930 {
931 if (print_symbol_loading_p (from_tty, 0, 0))
932 {
933 if (pattern != NULL)
934 {
935 printf_unfiltered (_("Loading symbols for shared libraries: %s\n"),
936 pattern);
937 }
938 else
939 printf_unfiltered (_("Loading symbols for shared libraries.\n"));
940 }
941
942 current_program_space->solib_add_generation++;
943
944 if (pattern)
945 {
946 char *re_err = re_comp (pattern);
947
948 if (re_err)
949 error (_("Invalid regexp: %s"), re_err);
950 }
951
952 update_solib_list (from_tty);
953
954 /* Walk the list of currently loaded shared libraries, and read
955 symbols for any that match the pattern --- or any whose symbols
956 aren't already loaded, if no pattern was given. */
957 {
958 bool any_matches = false;
959 bool loaded_any_symbols = false;
960 symfile_add_flags add_flags = SYMFILE_DEFER_BP_RESET;
961
962 if (from_tty)
963 add_flags |= SYMFILE_VERBOSE;
964
965 for (struct so_list *gdb : current_program_space->solibs ())
966 if (! pattern || re_exec (gdb->so_name))
967 {
968 /* Normally, we would read the symbols from that library
969 only if READSYMS is set. However, we're making a small
970 exception for the pthread library, because we sometimes
971 need the library symbols to be loaded in order to provide
972 thread support (x86-linux for instance). */
973 const int add_this_solib =
974 (readsyms || libpthread_solib_p (gdb));
975
976 any_matches = true;
977 if (add_this_solib)
978 {
979 if (gdb->symbols_loaded)
980 {
981 /* If no pattern was given, be quiet for shared
982 libraries we have already loaded. */
983 if (pattern && (from_tty || info_verbose))
984 printf_unfiltered (_("Symbols already loaded for %s\n"),
985 gdb->so_name);
986 }
987 else if (solib_read_symbols (gdb, add_flags))
988 loaded_any_symbols = true;
989 }
990 }
991
992 if (loaded_any_symbols)
993 breakpoint_re_set ();
994
995 if (from_tty && pattern && ! any_matches)
996 printf_unfiltered
997 ("No loaded shared libraries match the pattern `%s'.\n", pattern);
998
999 if (loaded_any_symbols)
1000 {
1001 /* Getting new symbols may change our opinion about what is
1002 frameless. */
1003 reinit_frame_cache ();
1004 }
1005 }
1006 }
1007
1008 /* Implement the "info sharedlibrary" command. Walk through the
1009 shared library list and print information about each attached
1010 library matching PATTERN. If PATTERN is elided, print them
1011 all. */
1012
1013 static void
1014 info_sharedlibrary_command (const char *pattern, int from_tty)
1015 {
1016 bool so_missing_debug_info = false;
1017 int addr_width;
1018 int nr_libs;
1019 struct gdbarch *gdbarch = target_gdbarch ();
1020 struct ui_out *uiout = current_uiout;
1021
1022 if (pattern)
1023 {
1024 char *re_err = re_comp (pattern);
1025
1026 if (re_err)
1027 error (_("Invalid regexp: %s"), re_err);
1028 }
1029
1030 /* "0x", a little whitespace, and two hex digits per byte of pointers. */
1031 addr_width = 4 + (gdbarch_ptr_bit (gdbarch) / 4);
1032
1033 update_solib_list (from_tty);
1034
1035 /* ui_out_emit_table table_emitter needs to know the number of rows,
1036 so we need to make two passes over the libs. */
1037
1038 nr_libs = 0;
1039 for (struct so_list *so : current_program_space->solibs ())
1040 {
1041 if (so->so_name[0])
1042 {
1043 if (pattern && ! re_exec (so->so_name))
1044 continue;
1045 ++nr_libs;
1046 }
1047 }
1048
1049 {
1050 ui_out_emit_table table_emitter (uiout, 4, nr_libs, "SharedLibraryTable");
1051
1052 /* The "- 1" is because ui_out adds one space between columns. */
1053 uiout->table_header (addr_width - 1, ui_left, "from", "From");
1054 uiout->table_header (addr_width - 1, ui_left, "to", "To");
1055 uiout->table_header (12 - 1, ui_left, "syms-read", "Syms Read");
1056 uiout->table_header (0, ui_noalign, "name", "Shared Object Library");
1057
1058 uiout->table_body ();
1059
1060 for (struct so_list *so : current_program_space->solibs ())
1061 {
1062 if (! so->so_name[0])
1063 continue;
1064 if (pattern && ! re_exec (so->so_name))
1065 continue;
1066
1067 ui_out_emit_tuple tuple_emitter (uiout, "lib");
1068
1069 if (so->addr_high != 0)
1070 {
1071 uiout->field_core_addr ("from", gdbarch, so->addr_low);
1072 uiout->field_core_addr ("to", gdbarch, so->addr_high);
1073 }
1074 else
1075 {
1076 uiout->field_skip ("from");
1077 uiout->field_skip ("to");
1078 }
1079
1080 if (! top_level_interpreter ()->interp_ui_out ()->is_mi_like_p ()
1081 && so->symbols_loaded
1082 && !objfile_has_symbols (so->objfile))
1083 {
1084 so_missing_debug_info = true;
1085 uiout->field_string ("syms-read", "Yes (*)");
1086 }
1087 else
1088 uiout->field_string ("syms-read", so->symbols_loaded ? "Yes" : "No");
1089
1090 uiout->field_string ("name", so->so_name, file_name_style.style ());
1091
1092 uiout->text ("\n");
1093 }
1094 }
1095
1096 if (nr_libs == 0)
1097 {
1098 if (pattern)
1099 uiout->message (_("No shared libraries matched.\n"));
1100 else
1101 uiout->message (_("No shared libraries loaded at this time.\n"));
1102 }
1103 else
1104 {
1105 if (so_missing_debug_info)
1106 uiout->message (_("(*): Shared library is missing "
1107 "debugging information.\n"));
1108 }
1109 }
1110
1111 /* See solib.h. */
1112
1113 bool
1114 solib_contains_address_p (const struct so_list *const solib,
1115 CORE_ADDR address)
1116 {
1117 if (solib->sections == nullptr)
1118 return false;
1119
1120 for (target_section &p : *solib->sections)
1121 if (p.addr <= address && address < p.endaddr)
1122 return true;
1123
1124 return false;
1125 }
1126
1127 /* If ADDRESS is in a shared lib in program space PSPACE, return its
1128 name.
1129
1130 Provides a hook for other gdb routines to discover whether or not a
1131 particular address is within the mapped address space of a shared
1132 library.
1133
1134 For example, this routine is called at one point to disable
1135 breakpoints which are in shared libraries that are not currently
1136 mapped in. */
1137
1138 char *
1139 solib_name_from_address (struct program_space *pspace, CORE_ADDR address)
1140 {
1141 struct so_list *so = NULL;
1142
1143 for (so = pspace->so_list; so; so = so->next)
1144 if (solib_contains_address_p (so, address))
1145 return (so->so_name);
1146
1147 return (0);
1148 }
1149
1150 /* See solib.h. */
1151
1152 bool
1153 solib_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
1154 {
1155 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
1156
1157 if (ops->keep_data_in_core)
1158 return ops->keep_data_in_core (vaddr, size) != 0;
1159 else
1160 return false;
1161 }
1162
1163 /* Called by free_all_symtabs */
1164
1165 void
1166 clear_solib (void)
1167 {
1168 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
1169
1170 disable_breakpoints_in_shlibs ();
1171
1172 while (current_program_space->so_list)
1173 {
1174 struct so_list *so = current_program_space->so_list;
1175
1176 current_program_space->so_list = so->next;
1177 gdb::observers::solib_unloaded.notify (so);
1178 current_program_space->remove_target_sections (so);
1179 free_so (so);
1180 }
1181
1182 ops->clear_solib ();
1183 }
1184
1185 /* Shared library startup support. When GDB starts up the inferior,
1186 it nurses it along (through the shell) until it is ready to execute
1187 its first instruction. At this point, this function gets
1188 called. */
1189
1190 void
1191 solib_create_inferior_hook (int from_tty)
1192 {
1193 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
1194
1195 ops->solib_create_inferior_hook (from_tty);
1196 }
1197
1198 /* See solib.h. */
1199
1200 bool
1201 in_solib_dynsym_resolve_code (CORE_ADDR pc)
1202 {
1203 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
1204
1205 return ops->in_dynsym_resolve_code (pc) != 0;
1206 }
1207
1208 /* Implements the "sharedlibrary" command. */
1209
1210 static void
1211 sharedlibrary_command (const char *args, int from_tty)
1212 {
1213 dont_repeat ();
1214 solib_add (args, from_tty, 1);
1215 }
1216
1217 /* Implements the command "nosharedlibrary", which discards symbols
1218 that have been auto-loaded from shared libraries. Symbols from
1219 shared libraries that were added by explicit request of the user
1220 are not discarded. Also called from remote.c. */
1221
1222 void
1223 no_shared_libraries (const char *ignored, int from_tty)
1224 {
1225 /* The order of the two routines below is important: clear_solib notifies
1226 the solib_unloaded observers, and some of these observers might need
1227 access to their associated objfiles. Therefore, we can not purge the
1228 solibs' objfiles before clear_solib has been called. */
1229
1230 clear_solib ();
1231 objfile_purge_solibs ();
1232 }
1233
1234 /* See solib.h. */
1235
1236 void
1237 update_solib_breakpoints (void)
1238 {
1239 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
1240
1241 if (ops->update_breakpoints != NULL)
1242 ops->update_breakpoints ();
1243 }
1244
1245 /* See solib.h. */
1246
1247 void
1248 handle_solib_event (void)
1249 {
1250 const struct target_so_ops *ops = solib_ops (target_gdbarch ());
1251
1252 if (ops->handle_event != NULL)
1253 ops->handle_event ();
1254
1255 current_inferior ()->pspace->clear_solib_cache ();
1256
1257 /* Check for any newly added shared libraries if we're supposed to
1258 be adding them automatically. Switch terminal for any messages
1259 produced by breakpoint_re_set. */
1260 target_terminal::ours_for_output ();
1261 solib_add (NULL, 0, auto_solib_add);
1262 target_terminal::inferior ();
1263 }
1264
1265 /* Reload shared libraries, but avoid reloading the same symbol file
1266 we already have loaded. */
1267
1268 static void
1269 reload_shared_libraries_1 (int from_tty)
1270 {
1271 if (print_symbol_loading_p (from_tty, 0, 0))
1272 printf_unfiltered (_("Loading symbols for shared libraries.\n"));
1273
1274 for (struct so_list *so : current_program_space->solibs ())
1275 {
1276 const char *found_pathname = NULL;
1277 bool was_loaded = so->symbols_loaded != 0;
1278 symfile_add_flags add_flags = SYMFILE_DEFER_BP_RESET;
1279
1280 if (from_tty)
1281 add_flags |= SYMFILE_VERBOSE;
1282
1283 gdb::unique_xmalloc_ptr<char> filename
1284 (tilde_expand (so->so_original_name));
1285 gdb_bfd_ref_ptr abfd (solib_bfd_open (filename.get ()));
1286 if (abfd != NULL)
1287 found_pathname = bfd_get_filename (abfd.get ());
1288
1289 /* If this shared library is no longer associated with its previous
1290 symbol file, close that. */
1291 if ((found_pathname == NULL && was_loaded)
1292 || (found_pathname != NULL
1293 && filename_cmp (found_pathname, so->so_name) != 0))
1294 {
1295 if (so->objfile && ! (so->objfile->flags & OBJF_USERLOADED)
1296 && !solib_used (so))
1297 so->objfile->unlink ();
1298 current_program_space->remove_target_sections (so);
1299 clear_so (so);
1300 }
1301
1302 /* If this shared library is now associated with a new symbol
1303 file, open it. */
1304 if (found_pathname != NULL
1305 && (!was_loaded
1306 || filename_cmp (found_pathname, so->so_name) != 0))
1307 {
1308 bool got_error = false;
1309
1310 try
1311 {
1312 solib_map_sections (so);
1313 }
1314
1315 catch (const gdb_exception_error &e)
1316 {
1317 exception_fprintf (gdb_stderr, e,
1318 _("Error while mapping "
1319 "shared library sections:\n"));
1320 got_error = true;
1321 }
1322
1323 if (!got_error
1324 && (auto_solib_add || was_loaded || libpthread_solib_p (so)))
1325 solib_read_symbols (so, add_flags);
1326 }
1327 }
1328 }
1329
1330 static void
1331 reload_shared_libraries (const char *ignored, int from_tty,
1332 struct cmd_list_element *e)
1333 {
1334 const struct target_so_ops *ops;
1335
1336 reload_shared_libraries_1 (from_tty);
1337
1338 ops = solib_ops (target_gdbarch ());
1339
1340 /* Creating inferior hooks here has two purposes. First, if we reload
1341 shared libraries then the address of solib breakpoint we've computed
1342 previously might be no longer valid. For example, if we forgot to set
1343 solib-absolute-prefix and are setting it right now, then the previous
1344 breakpoint address is plain wrong. Second, installing solib hooks
1345 also implicitly figures were ld.so is and loads symbols for it.
1346 Absent this call, if we've just connected to a target and set
1347 solib-absolute-prefix or solib-search-path, we'll lose all information
1348 about ld.so. */
1349 if (target_has_execution ())
1350 {
1351 /* Reset or free private data structures not associated with
1352 so_list entries. */
1353 ops->clear_solib ();
1354
1355 /* Remove any previous solib event breakpoint. This is usually
1356 done in common code, at breakpoint_init_inferior time, but
1357 we're not really starting up the inferior here. */
1358 remove_solib_event_breakpoints ();
1359
1360 solib_create_inferior_hook (from_tty);
1361 }
1362
1363 /* Sometimes the platform-specific hook loads initial shared
1364 libraries, and sometimes it doesn't. If it doesn't FROM_TTY will be
1365 incorrectly 0 but such solib targets should be fixed anyway. If we
1366 made all the inferior hook methods consistent, this call could be
1367 removed. Call it only after the solib target has been initialized by
1368 solib_create_inferior_hook. */
1369
1370 solib_add (NULL, 0, auto_solib_add);
1371
1372 breakpoint_re_set ();
1373
1374 /* We may have loaded or unloaded debug info for some (or all)
1375 shared libraries. However, frames may still reference them. For
1376 example, a frame's unwinder might still point at DWARF FDE
1377 structures that are now freed. Also, getting new symbols may
1378 change our opinion about what is frameless. */
1379 reinit_frame_cache ();
1380 }
1381
1382 /* Wrapper for reload_shared_libraries that replaces "remote:"
1383 at the start of gdb_sysroot with "target:". */
1384
1385 static void
1386 gdb_sysroot_changed (const char *ignored, int from_tty,
1387 struct cmd_list_element *e)
1388 {
1389 const char *old_prefix = "remote:";
1390 const char *new_prefix = TARGET_SYSROOT_PREFIX;
1391
1392 if (startswith (gdb_sysroot, old_prefix))
1393 {
1394 static bool warning_issued = false;
1395
1396 gdb_assert (strlen (old_prefix) == strlen (new_prefix));
1397 memcpy (gdb_sysroot, new_prefix, strlen (new_prefix));
1398
1399 if (!warning_issued)
1400 {
1401 warning (_("\"%s\" is deprecated, use \"%s\" instead."),
1402 old_prefix, new_prefix);
1403 warning (_("sysroot set to \"%s\"."), gdb_sysroot);
1404
1405 warning_issued = true;
1406 }
1407 }
1408
1409 reload_shared_libraries (ignored, from_tty, e);
1410 }
1411
1412 static void
1413 show_auto_solib_add (struct ui_file *file, int from_tty,
1414 struct cmd_list_element *c, const char *value)
1415 {
1416 fprintf_filtered (file, _("Autoloading of shared library symbols is %s.\n"),
1417 value);
1418 }
1419
1420
1421 /* Lookup the value for a specific symbol from dynamic symbol table. Look
1422 up symbol from ABFD. MATCH_SYM is a callback function to determine
1423 whether to pick up a symbol. DATA is the input of this callback
1424 function. Return NULL if symbol is not found. */
1425
1426 CORE_ADDR
1427 gdb_bfd_lookup_symbol_from_symtab (bfd *abfd,
1428 int (*match_sym) (const asymbol *,
1429 const void *),
1430 const void *data)
1431 {
1432 long storage_needed = bfd_get_symtab_upper_bound (abfd);
1433 CORE_ADDR symaddr = 0;
1434
1435 if (storage_needed > 0)
1436 {
1437 unsigned int i;
1438
1439 gdb::def_vector<asymbol *> storage (storage_needed / sizeof (asymbol *));
1440 asymbol **symbol_table = storage.data ();
1441 unsigned int number_of_symbols =
1442 bfd_canonicalize_symtab (abfd, symbol_table);
1443
1444 for (i = 0; i < number_of_symbols; i++)
1445 {
1446 asymbol *sym = *symbol_table++;
1447
1448 if (match_sym (sym, data))
1449 {
1450 struct gdbarch *gdbarch = target_gdbarch ();
1451 symaddr = sym->value;
1452
1453 /* Some ELF targets fiddle with addresses of symbols they
1454 consider special. They use minimal symbols to do that
1455 and this is needed for correct breakpoint placement,
1456 but we do not have full data here to build a complete
1457 minimal symbol, so just set the address and let the
1458 targets cope with that. */
1459 if (bfd_get_flavour (abfd) == bfd_target_elf_flavour
1460 && gdbarch_elf_make_msymbol_special_p (gdbarch))
1461 {
1462 struct minimal_symbol msym {};
1463
1464 SET_MSYMBOL_VALUE_ADDRESS (&msym, symaddr);
1465 gdbarch_elf_make_msymbol_special (gdbarch, sym, &msym);
1466 symaddr = MSYMBOL_VALUE_RAW_ADDRESS (&msym);
1467 }
1468
1469 /* BFD symbols are section relative. */
1470 symaddr += sym->section->vma;
1471 break;
1472 }
1473 }
1474 }
1475
1476 return symaddr;
1477 }
1478
1479 /* Lookup the value for a specific symbol from symbol table. Look up symbol
1480 from ABFD. MATCH_SYM is a callback function to determine whether to pick
1481 up a symbol. DATA is the input of this callback function. Return NULL
1482 if symbol is not found. */
1483
1484 static CORE_ADDR
1485 bfd_lookup_symbol_from_dyn_symtab (bfd *abfd,
1486 int (*match_sym) (const asymbol *,
1487 const void *),
1488 const void *data)
1489 {
1490 long storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd);
1491 CORE_ADDR symaddr = 0;
1492
1493 if (storage_needed > 0)
1494 {
1495 unsigned int i;
1496 gdb::def_vector<asymbol *> storage (storage_needed / sizeof (asymbol *));
1497 asymbol **symbol_table = storage.data ();
1498 unsigned int number_of_symbols =
1499 bfd_canonicalize_dynamic_symtab (abfd, symbol_table);
1500
1501 for (i = 0; i < number_of_symbols; i++)
1502 {
1503 asymbol *sym = *symbol_table++;
1504
1505 if (match_sym (sym, data))
1506 {
1507 /* BFD symbols are section relative. */
1508 symaddr = sym->value + sym->section->vma;
1509 break;
1510 }
1511 }
1512 }
1513 return symaddr;
1514 }
1515
1516 /* Lookup the value for a specific symbol from symbol table and dynamic
1517 symbol table. Look up symbol from ABFD. MATCH_SYM is a callback
1518 function to determine whether to pick up a symbol. DATA is the
1519 input of this callback function. Return NULL if symbol is not
1520 found. */
1521
1522 CORE_ADDR
1523 gdb_bfd_lookup_symbol (bfd *abfd,
1524 int (*match_sym) (const asymbol *, const void *),
1525 const void *data)
1526 {
1527 CORE_ADDR symaddr = gdb_bfd_lookup_symbol_from_symtab (abfd, match_sym, data);
1528
1529 /* On FreeBSD, the dynamic linker is stripped by default. So we'll
1530 have to check the dynamic string table too. */
1531 if (symaddr == 0)
1532 symaddr = bfd_lookup_symbol_from_dyn_symtab (abfd, match_sym, data);
1533
1534 return symaddr;
1535 }
1536
1537 /* The shared library list may contain user-loaded object files that
1538 can be removed out-of-band by the user. So upon notification of
1539 free_objfile remove all references to any user-loaded file that is
1540 about to be freed. */
1541
1542 static void
1543 remove_user_added_objfile (struct objfile *objfile)
1544 {
1545 if (objfile != 0 && objfile->flags & OBJF_USERLOADED)
1546 {
1547 for (struct so_list *so : current_program_space->solibs ())
1548 if (so->objfile == objfile)
1549 so->objfile = NULL;
1550 }
1551 }
1552
1553 void _initialize_solib ();
1554 void
1555 _initialize_solib ()
1556 {
1557 solib_data = gdbarch_data_register_pre_init (solib_init);
1558
1559 gdb::observers::free_objfile.attach (remove_user_added_objfile,
1560 "solib");
1561 gdb::observers::inferior_execd.attach ([] (inferior *inf)
1562 {
1563 solib_create_inferior_hook (0);
1564 }, "solib");
1565
1566 add_com ("sharedlibrary", class_files, sharedlibrary_command,
1567 _("Load shared object library symbols for files matching REGEXP."));
1568 add_info ("sharedlibrary", info_sharedlibrary_command,
1569 _("Status of loaded shared object libraries."));
1570 add_info_alias ("dll", "sharedlibrary", 1);
1571 add_com ("nosharedlibrary", class_files, no_shared_libraries,
1572 _("Unload all shared object library symbols."));
1573
1574 add_setshow_boolean_cmd ("auto-solib-add", class_support,
1575 &auto_solib_add, _("\
1576 Set autoloading of shared library symbols."), _("\
1577 Show autoloading of shared library symbols."), _("\
1578 If \"on\", symbols from all shared object libraries will be loaded\n\
1579 automatically when the inferior begins execution, when the dynamic linker\n\
1580 informs gdb that a new library has been loaded, or when attaching to the\n\
1581 inferior. Otherwise, symbols must be loaded manually, using \
1582 `sharedlibrary'."),
1583 NULL,
1584 show_auto_solib_add,
1585 &setlist, &showlist);
1586
1587 add_setshow_optional_filename_cmd ("sysroot", class_support,
1588 &gdb_sysroot, _("\
1589 Set an alternate system root."), _("\
1590 Show the current system root."), _("\
1591 The system root is used to load absolute shared library symbol files.\n\
1592 For other (relative) files, you can add directories using\n\
1593 `set solib-search-path'."),
1594 gdb_sysroot_changed,
1595 NULL,
1596 &setlist, &showlist);
1597
1598 add_alias_cmd ("solib-absolute-prefix", "sysroot", class_support, 0,
1599 &setlist);
1600 add_alias_cmd ("solib-absolute-prefix", "sysroot", class_support, 0,
1601 &showlist);
1602
1603 add_setshow_optional_filename_cmd ("solib-search-path", class_support,
1604 &solib_search_path, _("\
1605 Set the search path for loading non-absolute shared library symbol files."),
1606 _("\
1607 Show the search path for loading non-absolute shared library symbol files."),
1608 _("\
1609 This takes precedence over the environment variables \
1610 PATH and LD_LIBRARY_PATH."),
1611 reload_shared_libraries,
1612 show_solib_search_path,
1613 &setlist, &showlist);
1614 }