gdb/solib.c

   1 /* Handle shared libraries for GDB, the GNU Debugger.
   2    Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   3    2000, 2001
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "defs.h"
  24
  25 #include <sys/types.h>
  26 #include <fcntl.h>
  27 #include "gdb_string.h"
  28 #include "symtab.h"
  29 #include "bfd.h"
  30 #include "symfile.h"
  31 #include "objfiles.h"
  32 #include "gdbcore.h"
  33 #include "command.h"
  34 #include "target.h"
  35 #include "frame.h"
  36 #include "gdb_regex.h"
  37 #include "inferior.h"
  38 #include "environ.h"
  39 #include "language.h"
  40 #include "gdbcmd.h"
  41 #include "completer.h"
  42 #include "filenames.h"          /* for DOSish file names */
  43
  44 #include "solist.h"
  45
  46 /* external data declarations */
  47
  48 /* FIXME: gdbarch needs to control this variable */
  49 struct target_so_ops *current_target_so_ops;
  50
  51 /* local data declarations */
  52
  53 static struct so_list *so_list_head;    /* List of known shared objects */
  54
  55 static int solib_cleanup_queued = 0;    /* make_run_cleanup called */
  56
  57 /* Local function prototypes */
  58
  59 static void do_clear_solib (PTR);
  60
  61 /* If non-zero, this is a prefix that will be added to the front of the name
  62    shared libraries with an absolute filename for loading.  */
  63 static char *solib_absolute_prefix = NULL;
  64
  65 /* If non-empty, this is a search path for loading non-absolute shared library
  66    symbol files.  This takes precedence over the environment variables PATH
  67    and LD_LIBRARY_PATH.  */
  68 static char *solib_search_path = NULL;
  69
  70 /*
  71
  72    GLOBAL FUNCTION
  73
  74    solib_open -- Find a shared library file and open it.
  75
  76    SYNOPSIS
  77
  78    int solib_open (char *in_patname, char **found_pathname);
  79
  80    DESCRIPTION
  81
  82    Global variable SOLIB_ABSOLUTE_PREFIX is used as a prefix directory
  83    to search for shared libraries if they have an absolute path.
  84
  85    Global variable SOLIB_SEARCH_PATH is used as a prefix directory
  86    (or set of directories, as in LD_LIBRARY_PATH) to search for all
  87    shared libraries if not found in SOLIB_ABSOLUTE_PREFIX.
  88
  89    Search order:
  90    * If path is absolute, look in SOLIB_ABSOLUTE_PREFIX.
  91    * If path is absolute or relative, look for it literally (unmodified).
  92    * Look in SOLIB_SEARCH_PATH.
  93    * Look in inferior's $PATH.
  94    * Look in inferior's $LD_LIBRARY_PATH.
  95
  96    RETURNS
  97
  98    file handle for opened solib, or -1 for failure.  */
  99
 100 int
 101 solib_open (char *in_pathname, char **found_pathname)
 102 {
 103   int found_file = -1;
 104   char *temp_pathname = NULL;
 105   char *p = in_pathname;
 106
 107   while (*p && !IS_DIR_SEPARATOR (*p))
 108     p++;
 109
 110   if (*p)
 111     {
 112       if (! IS_ABSOLUTE_PATH (in_pathname) || solib_absolute_prefix == NULL)
 113         temp_pathname = in_pathname;
 114       else
 115         {
 116           int prefix_len = strlen (solib_absolute_prefix);
 117
 118           /* Remove trailing slashes from absolute prefix.  */
 119           while (prefix_len > 0
 120                  && IS_DIR_SEPARATOR (solib_absolute_prefix[prefix_len - 1]))
 121             prefix_len--;
 122
 123           /* Cat the prefixed pathname together.  */
 124           temp_pathname = alloca (prefix_len + strlen (in_pathname) + 1);
 125           strncpy (temp_pathname, solib_absolute_prefix, prefix_len);
 126           temp_pathname[prefix_len] = '\0';
 127           strcat (temp_pathname, in_pathname);
 128         }
 129
 130       /* Now see if we can open it.  */
 131       found_file = open (temp_pathname, O_RDONLY, 0);
 132     }
 133
 134   /* If not found, next search the solib_search_path (if any).  */
 135   if (found_file < 0 && solib_search_path != NULL)
 136     found_file = openp (solib_search_path,
 137                         1, in_pathname, O_RDONLY, 0, &temp_pathname);
 138
 139   /* If not found, next search the inferior's $PATH environment variable. */
 140   if (found_file < 0 && solib_search_path != NULL)
 141     found_file = openp (get_in_environ (inferior_environ, "PATH"),
 142                         1, in_pathname, O_RDONLY, 0, &temp_pathname);
 143
 144   /* If not found, next search the inferior's $LD_LIBRARY_PATH
 145      environment variable. */
 146   if (found_file < 0 && solib_search_path != NULL)
 147     found_file = openp (get_in_environ (inferior_environ, "LD_LIBRARY_PATH"),
 148                         1, in_pathname, O_RDONLY, 0, &temp_pathname);
 149
 150   /* Done.  If not found, tough luck.  Return found_file and
 151      (optionally) found_pathname.  */
 152   if (found_pathname != NULL && temp_pathname != NULL)
 153     *found_pathname = xstrdup (temp_pathname);
 154   return found_file;
 155 }
 156
 157
 158 /*
 159
 160    LOCAL FUNCTION
 161
 162    solib_map_sections -- open bfd and build sections for shared lib
 163
 164    SYNOPSIS
 165
 166    static int solib_map_sections (struct so_list *so)
 167
 168    DESCRIPTION
 169
 170    Given a pointer to one of the shared objects in our list
 171    of mapped objects, use the recorded name to open a bfd
 172    descriptor for the object, build a section table, and then
 173    relocate all the section addresses by the base address at
 174    which the shared object was mapped.
 175
 176    FIXMES
 177
 178    In most (all?) cases the shared object file name recorded in the
 179    dynamic linkage tables will be a fully qualified pathname.  For
 180    cases where it isn't, do we really mimic the systems search
 181    mechanism correctly in the below code (particularly the tilde
 182    expansion stuff?).
 183  */
 184
 185 static int
 186 solib_map_sections (PTR arg)
 187 {
 188   struct so_list *so = (struct so_list *) arg;  /* catch_errors bogon */
 189   char *filename;
 190   char *scratch_pathname;
 191   int scratch_chan;
 192   struct section_table *p;
 193   struct cleanup *old_chain;
 194   bfd *abfd;
 195
 196   filename = tilde_expand (so->so_name);
 197
 198   old_chain = make_cleanup (xfree, filename);
 199   scratch_chan = solib_open (filename, &scratch_pathname);
 200
 201   if (scratch_chan < 0)
 202     {
 203       perror_with_name (filename);
 204     }
 205
 206   /* Leave scratch_pathname allocated.  abfd->name will point to it.  */
 207   abfd = bfd_fdopenr (scratch_pathname, gnutarget, scratch_chan);
 208   if (!abfd)
 209     {
 210       close (scratch_chan);
 211       error ("Could not open `%s' as an executable file: %s",
 212              scratch_pathname, bfd_errmsg (bfd_get_error ()));
 213     }
 214
 215   /* Leave bfd open, core_xfer_memory and "info files" need it.  */
 216   so->abfd = abfd;
 217   abfd->cacheable = true;
 218
 219   /* copy full path name into so_name, so that later symbol_file_add
 220      can find it */
 221   if (strlen (scratch_pathname) >= SO_NAME_MAX_PATH_SIZE)
 222     error ("Full path name length of shared library exceeds SO_NAME_MAX_PATH_SIZE in so_list structure.");
 223   strcpy (so->so_name, scratch_pathname);
 224
 225   if (!bfd_check_format (abfd, bfd_object))
 226     {
 227       error ("\"%s\": not in executable format: %s.",
 228              scratch_pathname, bfd_errmsg (bfd_get_error ()));
 229     }
 230   if (build_section_table (abfd, &so->sections, &so->sections_end))
 231     {
 232       error ("Can't find the file sections in `%s': %s",
 233              bfd_get_filename (abfd), bfd_errmsg (bfd_get_error ()));
 234     }
 235
 236   for (p = so->sections; p < so->sections_end; p++)
 237     {
 238       /* Relocate the section binding addresses as recorded in the shared
 239          object's file by the base address to which the object was actually
 240          mapped. */
 241       TARGET_SO_RELOCATE_SECTION_ADDRESSES (so, p);
 242       if (STREQ (p->the_bfd_section->name, ".text"))
 243         {
 244           so->textsection = p;
 245         }
 246     }
 247
 248   /* Free the file names, close the file now.  */
 249   do_cleanups (old_chain);
 250
 251   return (1);
 252 }
 253
 254 /* LOCAL FUNCTION
 255
 256    free_so --- free a `struct so_list' object
 257
 258    SYNOPSIS
 259
 260    void free_so (struct so_list *so)
 261
 262    DESCRIPTION
 263
 264    Free the storage associated with the `struct so_list' object SO.
 265    If we have opened a BFD for SO, close it.
 266
 267    The caller is responsible for removing SO from whatever list it is
 268    a member of.  If we have placed SO's sections in some target's
 269    section table, the caller is responsible for removing them.
 270
 271    This function doesn't mess with objfiles at all.  If there is an
 272    objfile associated with SO that needs to be removed, the caller is
 273    responsible for taking care of that.  */
 274
 275 void
 276 free_so (struct so_list *so)
 277 {
 278   char *bfd_filename = 0;
 279
 280   if (so->sections)
 281     xfree (so->sections);
 282
 283   if (so->abfd)
 284     {
 285       bfd_filename = bfd_get_filename (so->abfd);
 286       if (! bfd_close (so->abfd))
 287         warning ("cannot close \"%s\": %s",
 288                  bfd_filename, bfd_errmsg (bfd_get_error ()));
 289     }
 290
 291   if (bfd_filename)
 292     xfree (bfd_filename);
 293
 294   TARGET_SO_FREE_SO (so);
 295
 296   xfree (so);
 297 }
 298
 299
 300 /* A small stub to get us past the arg-passing pinhole of catch_errors.  */
 301
 302 static int
 303 symbol_add_stub (PTR arg)
 304 {
 305   register struct so_list *so = (struct so_list *) arg;  /* catch_errs bogon */
 306   struct section_addr_info *sap;
 307
 308   /* Have we already loaded this shared object?  */
 309   ALL_OBJFILES (so->objfile)
 310     {
 311       if (strcmp (so->objfile->name, so->so_name) == 0)
 312         return 1;
 313     }
 314
 315   sap = build_section_addr_info_from_section_table (so->sections,
 316                                                     so->sections_end);
 317
 318   so->objfile = symbol_file_add (so->so_name, so->from_tty,
 319                                  sap, 0, OBJF_SHARED);
 320   free_section_addr_info (sap);
 321
 322   return (1);
 323 }
 324
 325
 326 /* LOCAL FUNCTION
 327
 328    update_solib_list --- synchronize GDB's shared object list with inferior's
 329
 330    SYNOPSIS
 331
 332    void update_solib_list (int from_tty, struct target_ops *TARGET)
 333
 334    Extract the list of currently loaded shared objects from the
 335    inferior, and compare it with the list of shared objects currently
 336    in GDB's so_list_head list.  Edit so_list_head to bring it in sync
 337    with the inferior's new list.
 338
 339    If we notice that the inferior has unloaded some shared objects,
 340    free any symbolic info GDB had read about those shared objects.
 341
 342    Don't load symbolic info for any new shared objects; just add them
 343    to the list, and leave their symbols_loaded flag clear.
 344
 345    If FROM_TTY is non-null, feel free to print messages about what
 346    we're doing.
 347
 348    If TARGET is non-null, add the sections of all new shared objects
 349    to TARGET's section table.  Note that this doesn't remove any
 350    sections for shared objects that have been unloaded, and it
 351    doesn't check to see if the new shared objects are already present in
 352    the section table.  But we only use this for core files and
 353    processes we've just attached to, so that's okay.  */
 354
 355 void
 356 update_solib_list (int from_tty, struct target_ops *target)
 357 {
 358   struct so_list *inferior = TARGET_SO_CURRENT_SOS ();
 359   struct so_list *gdb, **gdb_link;
 360
 361   /* If we are attaching to a running process for which we
 362      have not opened a symbol file, we may be able to get its
 363      symbols now!  */
 364   if (attach_flag &&
 365       symfile_objfile == NULL)
 366     catch_errors (TARGET_SO_OPEN_SYMBOL_FILE_OBJECT, (PTR) &from_tty,
 367                   "Error reading attached process's symbol file.\n",
 368                   RETURN_MASK_ALL);
 369
 370   /* Since this function might actually add some elements to the
 371      so_list_head list, arrange for it to be cleaned up when
 372      appropriate.  */
 373   if (!solib_cleanup_queued)
 374     {
 375       make_run_cleanup (do_clear_solib, NULL);
 376       solib_cleanup_queued = 1;
 377     }
 378
 379   /* GDB and the inferior's dynamic linker each maintain their own
 380      list of currently loaded shared objects; we want to bring the
 381      former in sync with the latter.  Scan both lists, seeing which
 382      shared objects appear where.  There are three cases:
 383
 384      - A shared object appears on both lists.  This means that GDB
 385      knows about it already, and it's still loaded in the inferior.
 386      Nothing needs to happen.
 387
 388      - A shared object appears only on GDB's list.  This means that
 389      the inferior has unloaded it.  We should remove the shared
 390      object from GDB's tables.
 391
 392      - A shared object appears only on the inferior's list.  This
 393      means that it's just been loaded.  We should add it to GDB's
 394      tables.
 395
 396      So we walk GDB's list, checking each entry to see if it appears
 397      in the inferior's list too.  If it does, no action is needed, and
 398      we remove it from the inferior's list.  If it doesn't, the
 399      inferior has unloaded it, and we remove it from GDB's list.  By
 400      the time we're done walking GDB's list, the inferior's list
 401      contains only the new shared objects, which we then add.  */
 402
 403   gdb = so_list_head;
 404   gdb_link = &so_list_head;
 405   while (gdb)
 406     {
 407       struct so_list *i = inferior;
 408       struct so_list **i_link = &inferior;
 409
 410       /* Check to see whether the shared object *gdb also appears in
 411          the inferior's current list.  */
 412       while (i)
 413         {
 414           if (! strcmp (gdb->so_original_name, i->so_original_name))
 415             break;
 416
 417           i_link = &i->next;
 418           i = *i_link;
 419         }
 420
 421       /* If the shared object appears on the inferior's list too, then
 422          it's still loaded, so we don't need to do anything.  Delete
 423          it from the inferior's list, and leave it on GDB's list.  */
 424       if (i)
 425         {
 426           *i_link = i->next;
 427           free_so (i);
 428           gdb_link = &gdb->next;
 429           gdb = *gdb_link;
 430         }
 431
 432       /* If it's not on the inferior's list, remove it from GDB's tables.  */
 433       else
 434         {
 435           *gdb_link = gdb->next;
 436
 437           /* Unless the user loaded it explicitly, free SO's objfile.  */
 438           if (gdb->objfile && ! (gdb->objfile->flags & OBJF_USERLOADED))
 439             free_objfile (gdb->objfile);
 440
 441           /* Some targets' section tables might be referring to
 442              sections from so->abfd; remove them.  */
 443           remove_target_sections (gdb->abfd);
 444
 445           free_so (gdb);
 446           gdb = *gdb_link;
 447         }
 448     }
 449
 450   /* Now the inferior's list contains only shared objects that don't
 451      appear in GDB's list --- those that are newly loaded.  Add them
 452      to GDB's shared object list.  */
 453   if (inferior)
 454     {
 455       struct so_list *i;
 456
 457       /* Add the new shared objects to GDB's list.  */
 458       *gdb_link = inferior;
 459
 460       /* Fill in the rest of each of the `struct so_list' nodes.  */
 461       for (i = inferior; i; i = i->next)
 462         {
 463           i->from_tty = from_tty;
 464
 465           /* Fill in the rest of the `struct so_list' node.  */
 466           catch_errors (solib_map_sections, i,
 467                         "Error while mapping shared library sections:\n",
 468                         RETURN_MASK_ALL);
 469
 470           /* If requested, add the shared object's sections to the TARGET's
 471              section table.  Do this immediately after mapping the object so
 472              that later nodes in the list can query this object, as is needed
 473              in solib-osf.c.  */
 474           if (target)
 475             {
 476               int count = (i->sections_end - i->sections);
 477               if (count > 0)
 478                 {
 479                   int space = target_resize_to_sections (target, count);
 480                   memcpy (target->to_sections + space,
 481                           i->sections,
 482                           count * sizeof (i->sections[0]));
 483                 }
 484             }
 485         }
 486     }
 487 }
 488
 489
 490 /* GLOBAL FUNCTION
 491
 492    solib_add -- read in symbol info for newly added shared libraries
 493
 494    SYNOPSIS
 495
 496    void solib_add (char *pattern, int from_tty, struct target_ops *TARGET)
 497
 498    DESCRIPTION
 499
 500    Read in symbolic information for any shared objects whose names
 501    match PATTERN.  (If we've already read a shared object's symbol
 502    info, leave it alone.)  If PATTERN is zero, read them all.
 503
 504    FROM_TTY and TARGET are as described for update_solib_list, above.  */
 505
 506 void
 507 solib_add (char *pattern, int from_tty, struct target_ops *target)
 508 {
 509   struct so_list *gdb;
 510
 511   if (pattern)
 512     {
 513       char *re_err = re_comp (pattern);
 514
 515       if (re_err)
 516         error ("Invalid regexp: %s", re_err);
 517     }
 518
 519   update_solib_list (from_tty, target);
 520
 521   /* Walk the list of currently loaded shared libraries, and read
 522      symbols for any that match the pattern --- or any whose symbols
 523      aren't already loaded, if no pattern was given.  */
 524   {
 525     int any_matches = 0;
 526     int loaded_any_symbols = 0;
 527
 528     for (gdb = so_list_head; gdb; gdb = gdb->next)
 529       if (! pattern || re_exec (gdb->so_name))
 530         {
 531           any_matches = 1;
 532
 533           if (gdb->symbols_loaded)
 534             {
 535               if (from_tty)
 536                 printf_unfiltered ("Symbols already loaded for %s\n",
 537                                    gdb->so_name);
 538             }
 539           else
 540             {
 541               if (catch_errors
 542                   (symbol_add_stub, gdb,
 543                    "Error while reading shared library symbols:\n",
 544                    RETURN_MASK_ALL))
 545                 {
 546                   if (from_tty)
 547                     printf_unfiltered ("Loaded symbols for %s\n",
 548                                        gdb->so_name);
 549                   gdb->symbols_loaded = 1;
 550                   loaded_any_symbols = 1;
 551                 }
 552             }
 553         }
 554
 555     if (from_tty && pattern && ! any_matches)
 556       printf_unfiltered
 557         ("No loaded shared libraries match the pattern `%s'.\n", pattern);
 558
 559     if (loaded_any_symbols)
 560       {
 561         /* Getting new symbols may change our opinion about what is
 562            frameless.  */
 563         reinit_frame_cache ();
 564
 565         TARGET_SO_SPECIAL_SYMBOL_HANDLING ();
 566       }
 567   }
 568 }
 569
 570
 571 /*
 572
 573    LOCAL FUNCTION
 574
 575    info_sharedlibrary_command -- code for "info sharedlibrary"
 576
 577    SYNOPSIS
 578
 579    static void info_sharedlibrary_command ()
 580
 581    DESCRIPTION
 582
 583    Walk through the shared library list and print information
 584    about each attached library.
 585  */
 586
 587 static void
 588 info_sharedlibrary_command (char *ignore, int from_tty)
 589 {
 590   register struct so_list *so = NULL;   /* link map state variable */
 591   int header_done = 0;
 592   int addr_width;
 593   char *addr_fmt;
 594   int arch_size;
 595
 596   if (exec_bfd == NULL)
 597     {
 598       printf_unfiltered ("No executable file.\n");
 599       return;
 600     }
 601
 602   arch_size = bfd_get_arch_size (exec_bfd);
 603   if (arch_size == -1)
 604     arch_size = bfd_arch_bits_per_address(exec_bfd);
 605
 606   /* Default to 32-bit in case of failure.  */
 607   if (arch_size == 32 || arch_size == -1)
 608     {
 609       addr_width = 8 + 4;
 610       addr_fmt = "08l";
 611     }
 612   else if (arch_size == 64)
 613     {
 614       addr_width = 16 + 4;
 615       addr_fmt = "016l";
 616     }
 617   else
 618     {
 619       internal_error (__FILE__, __LINE__,
 620                       "bfd_get_arch_size() returned unknown size %d",
 621                       arch_size);
 622     }
 623
 624   update_solib_list (from_tty, 0);
 625
 626   for (so = so_list_head; so; so = so->next)
 627     {
 628       if (so->so_name[0])
 629         {
 630           if (!header_done)
 631             {
 632               printf_unfiltered ("%-*s%-*s%-12s%s\n", addr_width, "From",
 633                                  addr_width, "To", "Syms Read",
 634                                  "Shared Object Library");
 635               header_done++;
 636             }
 637
 638           printf_unfiltered ("%-*s", addr_width,
 639                              so->textsection != NULL
 640                                ? longest_local_hex_string_custom (
 641                                    (LONGEST) so->textsection->addr,
 642                                    addr_fmt)
 643                                : "");
 644           printf_unfiltered ("%-*s", addr_width,
 645                              so->textsection != NULL
 646                                ? longest_local_hex_string_custom (
 647                                    (LONGEST) so->textsection->endaddr,
 648                                    addr_fmt)
 649                                : "");
 650           printf_unfiltered ("%-12s", so->symbols_loaded ? "Yes" : "No");
 651           printf_unfiltered ("%s\n", so->so_name);
 652         }
 653     }
 654   if (so_list_head == NULL)
 655     {
 656       printf_unfiltered ("No shared libraries loaded at this time.\n");
 657     }
 658 }
 659
 660 /*
 661
 662    GLOBAL FUNCTION
 663
 664    solib_address -- check to see if an address is in a shared lib
 665
 666    SYNOPSIS
 667
 668    char * solib_address (CORE_ADDR address)
 669
 670    DESCRIPTION
 671
 672    Provides a hook for other gdb routines to discover whether or
 673    not a particular address is within the mapped address space of
 674    a shared library.
 675
 676    For example, this routine is called at one point to disable
 677    breakpoints which are in shared libraries that are not currently
 678    mapped in.
 679  */
 680
 681 char *
 682 solib_address (CORE_ADDR address)
 683 {
 684   register struct so_list *so = 0;      /* link map state variable */
 685
 686   for (so = so_list_head; so; so = so->next)
 687     {
 688       struct section_table *p;
 689
 690       for (p = so->sections; p < so->sections_end; p++)
 691         {
 692           if (p->addr <= address && address < p->endaddr)
 693             return (so->so_name);
 694         }
 695     }
 696
 697   return (0);
 698 }
 699
 700 /* Called by free_all_symtabs */
 701
 702 void
 703 clear_solib (void)
 704 {
 705   /* This function is expected to handle ELF shared libraries.  It is
 706      also used on Solaris, which can run either ELF or a.out binaries
 707      (for compatibility with SunOS 4), both of which can use shared
 708      libraries.  So we don't know whether we have an ELF executable or
 709      an a.out executable until the user chooses an executable file.
 710
 711      ELF shared libraries don't get mapped into the address space
 712      until after the program starts, so we'd better not try to insert
 713      breakpoints in them immediately.  We have to wait until the
 714      dynamic linker has loaded them; we'll hit a bp_shlib_event
 715      breakpoint (look for calls to create_solib_event_breakpoint) when
 716      it's ready.
 717
 718      SunOS shared libraries seem to be different --- they're present
 719      as soon as the process begins execution, so there's no need to
 720      put off inserting breakpoints.  There's also nowhere to put a
 721      bp_shlib_event breakpoint, so if we put it off, we'll never get
 722      around to it.
 723
 724      So: disable breakpoints only if we're using ELF shared libs.  */
 725   if (exec_bfd != NULL
 726       && bfd_get_flavour (exec_bfd) != bfd_target_aout_flavour)
 727     disable_breakpoints_in_shlibs (1);
 728
 729   while (so_list_head)
 730     {
 731       struct so_list *so = so_list_head;
 732       so_list_head = so->next;
 733       free_so (so);
 734     }
 735
 736   TARGET_SO_CLEAR_SOLIB ();
 737 }
 738
 739 static void
 740 do_clear_solib (PTR dummy)
 741 {
 742   solib_cleanup_queued = 0;
 743   clear_solib ();
 744 }
 745
 746 /* GLOBAL FUNCTION
 747
 748    solib_create_inferior_hook -- shared library startup support
 749
 750    SYNOPSIS
 751
 752    void solib_create_inferior_hook()
 753
 754    DESCRIPTION
 755
 756    When gdb starts up the inferior, it nurses it along (through the
 757    shell) until it is ready to execute it's first instruction.  At this
 758    point, this function gets called via expansion of the macro
 759    SOLIB_CREATE_INFERIOR_HOOK.  */
 760
 761 void
 762 solib_create_inferior_hook (void)
 763 {
 764   TARGET_SO_SOLIB_CREATE_INFERIOR_HOOK ();
 765 }
 766
 767 /* GLOBAL FUNCTION
 768
 769    in_solib_dynsym_resolve_code -- check to see if an address is in
 770                                    dynamic loader's dynamic symbol
 771                                    resolution code
 772
 773    SYNOPSIS
 774
 775    int in_solib_dynsym_resolve_code (CORE_ADDR pc)
 776
 777    DESCRIPTION
 778
 779    Determine if PC is in the dynamic linker's symbol resolution
 780    code.  Return 1 if so, 0 otherwise.
 781 */
 782
 783 int
 784 in_solib_dynsym_resolve_code (CORE_ADDR pc)
 785 {
 786   return TARGET_SO_IN_DYNSYM_RESOLVE_CODE (pc);
 787 }
 788
 789 /*
 790
 791    LOCAL FUNCTION
 792
 793    sharedlibrary_command -- handle command to explicitly add library
 794
 795    SYNOPSIS
 796
 797    static void sharedlibrary_command (char *args, int from_tty)
 798
 799    DESCRIPTION
 800
 801  */
 802
 803 static void
 804 sharedlibrary_command (char *args, int from_tty)
 805 {
 806   dont_repeat ();
 807   solib_add (args, from_tty, (struct target_ops *) 0);
 808 }
 809
 810 /* LOCAL FUNCTION
 811
 812    no_shared_libraries -- handle command to explicitly discard symbols
 813    from shared libraries.
 814
 815    DESCRIPTION
 816
 817    Implements the command "nosharedlibrary", which discards symbols
 818    that have been auto-loaded from shared libraries.  Symbols from
 819    shared libraries that were added by explicit request of the user
 820    are not discarded.  Also called from remote.c.  */
 821
 822 void
 823 no_shared_libraries (char *ignored, int from_tty)
 824 {
 825   objfile_purge_solibs ();
 826   do_clear_solib (NULL);
 827 }
 828
 829 void
 830 _initialize_solib (void)
 831 {
 832   struct cmd_list_element *c;
 833
 834   add_com ("sharedlibrary", class_files, sharedlibrary_command,
 835            "Load shared object library symbols for files matching REGEXP.");
 836   add_info ("sharedlibrary", info_sharedlibrary_command,
 837             "Status of loaded shared object libraries.");
 838   add_com ("nosharedlibrary", class_files, no_shared_libraries,
 839            "Unload all shared object library symbols.");
 840
 841   add_show_from_set
 842     (add_set_cmd ("auto-solib-add", class_support, var_zinteger,
 843                   (char *) &auto_solib_add,
 844                   "Set autoloading of shared library symbols.\n\
 845 If nonzero, symbols from all shared object libraries will be loaded\n\
 846 automatically when the inferior begins execution or when the dynamic linker\n\
 847 informs gdb that a new library has been loaded.  Otherwise, symbols\n\
 848 must be loaded manually, using `sharedlibrary'.",
 849                   &setlist),
 850      &showlist);
 851
 852   c = add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
 853                    (char *) &solib_absolute_prefix,
 854                    "Set prefix for loading absolute shared library symbol files.\n\
 855 For other (relative) files, you can add values using `set solib-search-path'.",
 856                    &setlist);
 857   add_show_from_set (c, &showlist);
 858   c->completer = filename_completer;
 859
 860   c = add_set_cmd ("solib-search-path", class_support, var_string,
 861                    (char *) &solib_search_path,
 862                    "Set the search path for loading non-absolute shared library symbol files.\n\
 863 This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
 864                    &setlist);
 865   add_show_from_set (c, &showlist);
 866   c->completer = filename_completer;
 867 }