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
 497    *TARGET, int readsyms)
 498
 499    DESCRIPTION
 500
 501    Read in symbolic information for any shared objects whose names
 502    match PATTERN.  (If we've already read a shared object's symbol
 503    info, leave it alone.)  If PATTERN is zero, read them all.
 504
 505    If READSYMS is 0, defer reading symbolic information until later
 506    but still do any needed low level processing.
 507
 508    FROM_TTY and TARGET are as described for update_solib_list, above.  */
 509
 510 void
 511 solib_add (char *pattern, int from_tty, struct target_ops *target, int readsyms)
 512 {
 513   struct so_list *gdb;
 514
 515   if (pattern)
 516     {
 517       char *re_err = re_comp (pattern);
 518
 519       if (re_err)
 520         error ("Invalid regexp: %s", re_err);
 521     }
 522
 523   update_solib_list (from_tty, target);
 524
 525   /* Walk the list of currently loaded shared libraries, and read
 526      symbols for any that match the pattern --- or any whose symbols
 527      aren't already loaded, if no pattern was given.  */
 528   {
 529     int any_matches = 0;
 530     int loaded_any_symbols = 0;
 531
 532     for (gdb = so_list_head; gdb; gdb = gdb->next)
 533       if (! pattern || re_exec (gdb->so_name))
 534         {
 535           any_matches = 1;
 536
 537           if (gdb->symbols_loaded)
 538             {
 539               if (from_tty)
 540                 printf_unfiltered ("Symbols already loaded for %s\n",
 541                                    gdb->so_name);
 542             }
 543           else if (readsyms)
 544             {
 545               if (catch_errors
 546                   (symbol_add_stub, gdb,
 547                    "Error while reading shared library symbols:\n",
 548                    RETURN_MASK_ALL))
 549                 {
 550                   if (from_tty)
 551                     printf_unfiltered ("Loaded symbols for %s\n",
 552                                        gdb->so_name);
 553                   gdb->symbols_loaded = 1;
 554                   loaded_any_symbols = 1;
 555                 }
 556             }
 557         }
 558
 559     if (from_tty && pattern && ! any_matches)
 560       printf_unfiltered
 561         ("No loaded shared libraries match the pattern `%s'.\n", pattern);
 562
 563     if (loaded_any_symbols)
 564       {
 565         /* Getting new symbols may change our opinion about what is
 566            frameless.  */
 567         reinit_frame_cache ();
 568
 569         TARGET_SO_SPECIAL_SYMBOL_HANDLING ();
 570       }
 571   }
 572 }
 573
 574
 575 /*
 576
 577    LOCAL FUNCTION
 578
 579    info_sharedlibrary_command -- code for "info sharedlibrary"
 580
 581    SYNOPSIS
 582
 583    static void info_sharedlibrary_command ()
 584
 585    DESCRIPTION
 586
 587    Walk through the shared library list and print information
 588    about each attached library.
 589  */
 590
 591 static void
 592 info_sharedlibrary_command (char *ignore, int from_tty)
 593 {
 594   register struct so_list *so = NULL;   /* link map state variable */
 595   int header_done = 0;
 596   int addr_width;
 597   char *addr_fmt;
 598   int arch_size;
 599
 600   if (exec_bfd == NULL)
 601     {
 602       printf_unfiltered ("No executable file.\n");
 603       return;
 604     }
 605
 606   arch_size = bfd_get_arch_size (exec_bfd);
 607   if (arch_size == -1)
 608     arch_size = bfd_arch_bits_per_address(exec_bfd);
 609
 610   /* Default to 32-bit in case of failure.  */
 611   if (arch_size == 32 || arch_size == -1)
 612     {
 613       addr_width = 8 + 4;
 614       addr_fmt = "08l";
 615     }
 616   else if (arch_size == 64)
 617     {
 618       addr_width = 16 + 4;
 619       addr_fmt = "016l";
 620     }
 621   else
 622     {
 623       internal_error (__FILE__, __LINE__,
 624                       "bfd_get_arch_size() returned unknown size %d",
 625                       arch_size);
 626     }
 627
 628   update_solib_list (from_tty, 0);
 629
 630   for (so = so_list_head; so; so = so->next)
 631     {
 632       if (so->so_name[0])
 633         {
 634           if (!header_done)
 635             {
 636               printf_unfiltered ("%-*s%-*s%-12s%s\n", addr_width, "From",
 637                                  addr_width, "To", "Syms Read",
 638                                  "Shared Object Library");
 639               header_done++;
 640             }
 641
 642           printf_unfiltered ("%-*s", addr_width,
 643                              so->textsection != NULL
 644                                ? longest_local_hex_string_custom (
 645                                    (LONGEST) so->textsection->addr,
 646                                    addr_fmt)
 647                                : "");
 648           printf_unfiltered ("%-*s", addr_width,
 649                              so->textsection != NULL
 650                                ? longest_local_hex_string_custom (
 651                                    (LONGEST) so->textsection->endaddr,
 652                                    addr_fmt)
 653                                : "");
 654           printf_unfiltered ("%-12s", so->symbols_loaded ? "Yes" : "No");
 655           printf_unfiltered ("%s\n", so->so_name);
 656         }
 657     }
 658   if (so_list_head == NULL)
 659     {
 660       printf_unfiltered ("No shared libraries loaded at this time.\n");
 661     }
 662 }
 663
 664 /*
 665
 666    GLOBAL FUNCTION
 667
 668    solib_address -- check to see if an address is in a shared lib
 669
 670    SYNOPSIS
 671
 672    char * solib_address (CORE_ADDR address)
 673
 674    DESCRIPTION
 675
 676    Provides a hook for other gdb routines to discover whether or
 677    not a particular address is within the mapped address space of
 678    a shared library.
 679
 680    For example, this routine is called at one point to disable
 681    breakpoints which are in shared libraries that are not currently
 682    mapped in.
 683  */
 684
 685 char *
 686 solib_address (CORE_ADDR address)
 687 {
 688   register struct so_list *so = 0;      /* link map state variable */
 689
 690   for (so = so_list_head; so; so = so->next)
 691     {
 692       struct section_table *p;
 693
 694       for (p = so->sections; p < so->sections_end; p++)
 695         {
 696           if (p->addr <= address && address < p->endaddr)
 697             return (so->so_name);
 698         }
 699     }
 700
 701   return (0);
 702 }
 703
 704 /* Called by free_all_symtabs */
 705
 706 void
 707 clear_solib (void)
 708 {
 709   /* This function is expected to handle ELF shared libraries.  It is
 710      also used on Solaris, which can run either ELF or a.out binaries
 711      (for compatibility with SunOS 4), both of which can use shared
 712      libraries.  So we don't know whether we have an ELF executable or
 713      an a.out executable until the user chooses an executable file.
 714
 715      ELF shared libraries don't get mapped into the address space
 716      until after the program starts, so we'd better not try to insert
 717      breakpoints in them immediately.  We have to wait until the
 718      dynamic linker has loaded them; we'll hit a bp_shlib_event
 719      breakpoint (look for calls to create_solib_event_breakpoint) when
 720      it's ready.
 721
 722      SunOS shared libraries seem to be different --- they're present
 723      as soon as the process begins execution, so there's no need to
 724      put off inserting breakpoints.  There's also nowhere to put a
 725      bp_shlib_event breakpoint, so if we put it off, we'll never get
 726      around to it.
 727
 728      So: disable breakpoints only if we're using ELF shared libs.  */
 729   if (exec_bfd != NULL
 730       && bfd_get_flavour (exec_bfd) != bfd_target_aout_flavour)
 731     disable_breakpoints_in_shlibs (1);
 732
 733   while (so_list_head)
 734     {
 735       struct so_list *so = so_list_head;
 736       so_list_head = so->next;
 737       if (so->abfd)
 738         remove_target_sections (so->abfd);
 739       free_so (so);
 740     }
 741
 742   TARGET_SO_CLEAR_SOLIB ();
 743 }
 744
 745 static void
 746 do_clear_solib (PTR dummy)
 747 {
 748   solib_cleanup_queued = 0;
 749   clear_solib ();
 750 }
 751
 752 /* GLOBAL FUNCTION
 753
 754    solib_create_inferior_hook -- shared library startup support
 755
 756    SYNOPSIS
 757
 758    void solib_create_inferior_hook()
 759
 760    DESCRIPTION
 761
 762    When gdb starts up the inferior, it nurses it along (through the
 763    shell) until it is ready to execute it's first instruction.  At this
 764    point, this function gets called via expansion of the macro
 765    SOLIB_CREATE_INFERIOR_HOOK.  */
 766
 767 void
 768 solib_create_inferior_hook (void)
 769 {
 770   TARGET_SO_SOLIB_CREATE_INFERIOR_HOOK ();
 771 }
 772
 773 /* GLOBAL FUNCTION
 774
 775    in_solib_dynsym_resolve_code -- check to see if an address is in
 776                                    dynamic loader's dynamic symbol
 777                                    resolution code
 778
 779    SYNOPSIS
 780
 781    int in_solib_dynsym_resolve_code (CORE_ADDR pc)
 782
 783    DESCRIPTION
 784
 785    Determine if PC is in the dynamic linker's symbol resolution
 786    code.  Return 1 if so, 0 otherwise.
 787 */
 788
 789 int
 790 in_solib_dynsym_resolve_code (CORE_ADDR pc)
 791 {
 792   return TARGET_SO_IN_DYNSYM_RESOLVE_CODE (pc);
 793 }
 794
 795 /*
 796
 797    LOCAL FUNCTION
 798
 799    sharedlibrary_command -- handle command to explicitly add library
 800
 801    SYNOPSIS
 802
 803    static void sharedlibrary_command (char *args, int from_tty)
 804
 805    DESCRIPTION
 806
 807  */
 808
 809 static void
 810 sharedlibrary_command (char *args, int from_tty)
 811 {
 812   dont_repeat ();
 813   solib_add (args, from_tty, (struct target_ops *) 0, 1);
 814 }
 815
 816 /* LOCAL FUNCTION
 817
 818    no_shared_libraries -- handle command to explicitly discard symbols
 819    from shared libraries.
 820
 821    DESCRIPTION
 822
 823    Implements the command "nosharedlibrary", which discards symbols
 824    that have been auto-loaded from shared libraries.  Symbols from
 825    shared libraries that were added by explicit request of the user
 826    are not discarded.  Also called from remote.c.  */
 827
 828 void
 829 no_shared_libraries (char *ignored, int from_tty)
 830 {
 831   objfile_purge_solibs ();
 832   do_clear_solib (NULL);
 833 }
 834
 835 void
 836 _initialize_solib (void)
 837 {
 838   struct cmd_list_element *c;
 839
 840   add_com ("sharedlibrary", class_files, sharedlibrary_command,
 841            "Load shared object library symbols for files matching REGEXP.");
 842   add_info ("sharedlibrary", info_sharedlibrary_command,
 843             "Status of loaded shared object libraries.");
 844   add_com ("nosharedlibrary", class_files, no_shared_libraries,
 845            "Unload all shared object library symbols.");
 846
 847   add_show_from_set
 848     (add_set_cmd ("auto-solib-add", class_support, var_boolean,
 849                   (char *) &auto_solib_add,
 850                   "Set autoloading of shared library symbols.\n\
 851 If \"on\", symbols from all shared object libraries will be loaded\n\
 852 automatically when the inferior begins execution, when the dynamic linker\n\
 853 informs gdb that a new library has been loaded, or when attaching to the\n\
 854 inferior.  Otherwise, symbols must be loaded manually, using `sharedlibrary'.",
 855                   &setlist),
 856      &showlist);
 857
 858   c = add_set_cmd ("solib-absolute-prefix", class_support, var_filename,
 859                    (char *) &solib_absolute_prefix,
 860                    "Set prefix for loading absolute shared library symbol files.\n\
 861 For other (relative) files, you can add values using `set solib-search-path'.",
 862                    &setlist);
 863   add_show_from_set (c, &showlist);
 864   c->completer = filename_completer;
 865
 866   c = add_set_cmd ("solib-search-path", class_support, var_string,
 867                    (char *) &solib_search_path,
 868                    "Set the search path for loading non-absolute shared library symbol files.\n\
 869 This takes precedence over the environment variables PATH and LD_LIBRARY_PATH.",
 870                    &setlist);
 871   add_show_from_set (c, &showlist);
 872   c->completer = filename_completer;
 873 }