gdb/exec.c

   1 /* Work with executable files, for GDB.
   2
   3    Copyright (C) 1988-2013 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 #include "frame.h"
  22 #include "inferior.h"
  23 #include "target.h"
  24 #include "gdbcmd.h"
  25 #include "language.h"
  26 #include "filenames.h"
  27 #include "symfile.h"
  28 #include "objfiles.h"
  29 #include "completer.h"
  30 #include "value.h"
  31 #include "exec.h"
  32 #include "observer.h"
  33 #include "arch-utils.h"
  34 #include "gdbthread.h"
  35 #include "progspace.h"
  36 #include "gdb_bfd.h"
  37
  38 #include <fcntl.h>
  39 #include "readline/readline.h"
  40 #include "gdb_string.h"
  41
  42 #include "gdbcore.h"
  43
  44 #include <ctype.h>
  45 #include "gdb_stat.h"
  46
  47 void (*deprecated_file_changed_hook) (char *);
  48
  49 /* Prototypes for local functions */
  50
  51 static void file_command (char *, int);
  52
  53 static void set_section_command (char *, int);
  54
  55 static void exec_files_info (struct target_ops *);
  56
  57 static void init_exec_ops (void);
  58
  59 void _initialize_exec (void);
  60
  61 /* The target vector for executable files.  */
  62
  63 struct target_ops exec_ops;
  64
  65 /* True if the exec target is pushed on the stack.  */
  66 static int using_exec_ops;
  67
  68 /* Whether to open exec and core files read-only or read-write.  */
  69
  70 int write_files = 0;
  71 static void
  72 show_write_files (struct ui_file *file, int from_tty,
  73                   struct cmd_list_element *c, const char *value)
  74 {
  75   fprintf_filtered (file, _("Writing into executable and core files is %s.\n"),
  76                     value);
  77 }
  78
  79
  80 static void
  81 exec_open (char *args, int from_tty)
  82 {
  83   target_preopen (from_tty);
  84   exec_file_attach (args, from_tty);
  85 }
  86
  87 /* Close and clear exec_bfd.  If we end up with no target sections to
  88    read memory from, this unpushes the exec_ops target.  */
  89
  90 void
  91 exec_close (void)
  92 {
  93   if (exec_bfd)
  94     {
  95       bfd *abfd = exec_bfd;
  96
  97       gdb_bfd_unref (abfd);
  98
  99       /* Removing target sections may close the exec_ops target.
 100          Clear exec_bfd before doing so to prevent recursion.  */
 101       exec_bfd = NULL;
 102       exec_bfd_mtime = 0;
 103
 104       remove_target_sections (&exec_bfd);
 105
 106       xfree (exec_filename);
 107       exec_filename = NULL;
 108     }
 109 }
 110
 111 /* This is the target_close implementation.  Clears all target
 112    sections and closes all executable bfds from all program spaces.  */
 113
 114 static void
 115 exec_close_1 (void)
 116 {
 117   using_exec_ops = 0;
 118
 119   {
 120     struct program_space *ss;
 121     struct cleanup *old_chain;
 122
 123     old_chain = save_current_program_space ();
 124     ALL_PSPACES (ss)
 125     {
 126       set_current_program_space (ss);
 127
 128       /* Delete all target sections.  */
 129       resize_section_table
 130         (current_target_sections,
 131          -resize_section_table (current_target_sections, 0));
 132
 133       exec_close ();
 134     }
 135
 136     do_cleanups (old_chain);
 137   }
 138 }
 139
 140 void
 141 exec_file_clear (int from_tty)
 142 {
 143   /* Remove exec file.  */
 144   exec_close ();
 145
 146   if (from_tty)
 147     printf_unfiltered (_("No executable file now.\n"));
 148 }
 149
 150 /* Set FILENAME as the new exec file.
 151
 152    This function is intended to be behave essentially the same
 153    as exec_file_command, except that the latter will detect when
 154    a target is being debugged, and will ask the user whether it
 155    should be shut down first.  (If the answer is "no", then the
 156    new file is ignored.)
 157
 158    This file is used by exec_file_command, to do the work of opening
 159    and processing the exec file after any prompting has happened.
 160
 161    And, it is used by child_attach, when the attach command was
 162    given a pid but not a exec pathname, and the attach command could
 163    figure out the pathname from the pid.  (In this case, we shouldn't
 164    ask the user whether the current target should be shut down --
 165    we're supplying the exec pathname late for good reason.)  */
 166
 167 void
 168 exec_file_attach (char *filename, int from_tty)
 169 {
 170   /* Remove any previous exec file.  */
 171   exec_close ();
 172
 173   /* Now open and digest the file the user requested, if any.  */
 174
 175   if (!filename)
 176     {
 177       if (from_tty)
 178         printf_unfiltered (_("No executable file now.\n"));
 179
 180       set_gdbarch_from_file (NULL);
 181     }
 182   else
 183     {
 184       struct cleanup *cleanups;
 185       char *scratch_pathname, *canonical_pathname;
 186       int scratch_chan;
 187       struct target_section *sections = NULL, *sections_end = NULL;
 188       char **matching;
 189
 190       scratch_chan = openp (getenv ("PATH"), OPF_TRY_CWD_FIRST, filename,
 191                    write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
 192                             &scratch_pathname);
 193 #if defined(__GO32__) || defined(_WIN32) || defined(__CYGWIN__)
 194       if (scratch_chan < 0)
 195         {
 196           char *exename = alloca (strlen (filename) + 5);
 197
 198           strcat (strcpy (exename, filename), ".exe");
 199           scratch_chan = openp (getenv ("PATH"), OPF_TRY_CWD_FIRST, exename,
 200              write_files ? O_RDWR | O_BINARY : O_RDONLY | O_BINARY,
 201              &scratch_pathname);
 202         }
 203 #endif
 204       if (scratch_chan < 0)
 205         perror_with_name (filename);
 206
 207       cleanups = make_cleanup (xfree, scratch_pathname);
 208
 209       /* gdb_bfd_open (and its variants) prefers canonicalized pathname for
 210          better BFD caching.  */
 211       canonical_pathname = gdb_realpath (scratch_pathname);
 212       make_cleanup (xfree, canonical_pathname);
 213
 214       if (write_files)
 215         exec_bfd = gdb_bfd_fopen (canonical_pathname, gnutarget,
 216                                   FOPEN_RUB, scratch_chan);
 217       else
 218         exec_bfd = gdb_bfd_open (canonical_pathname, gnutarget, scratch_chan);
 219
 220       if (!exec_bfd)
 221         {
 222           error (_("\"%s\": could not open as an executable file: %s"),
 223                  scratch_pathname, bfd_errmsg (bfd_get_error ()));
 224         }
 225
 226       gdb_assert (exec_filename == NULL);
 227       exec_filename = xstrdup (scratch_pathname);
 228
 229       if (!bfd_check_format_matches (exec_bfd, bfd_object, &matching))
 230         {
 231           /* Make sure to close exec_bfd, or else "run" might try to use
 232              it.  */
 233           exec_close ();
 234           error (_("\"%s\": not in executable format: %s"),
 235                  scratch_pathname,
 236                  gdb_bfd_errmsg (bfd_get_error (), matching));
 237         }
 238
 239       if (build_section_table (exec_bfd, &sections, &sections_end))
 240         {
 241           /* Make sure to close exec_bfd, or else "run" might try to use
 242              it.  */
 243           exec_close ();
 244           error (_("\"%s\": can't find the file sections: %s"),
 245                  scratch_pathname, bfd_errmsg (bfd_get_error ()));
 246         }
 247
 248       exec_bfd_mtime = bfd_get_mtime (exec_bfd);
 249
 250       validate_files ();
 251
 252       set_gdbarch_from_file (exec_bfd);
 253
 254       /* Add the executable's sections to the current address spaces'
 255          list of sections.  This possibly pushes the exec_ops
 256          target.  */
 257       add_target_sections (&exec_bfd, sections, sections_end);
 258       xfree (sections);
 259
 260       /* Tell display code (if any) about the changed file name.  */
 261       if (deprecated_exec_file_display_hook)
 262         (*deprecated_exec_file_display_hook) (filename);
 263
 264       do_cleanups (cleanups);
 265     }
 266   bfd_cache_close_all ();
 267   observer_notify_executable_changed ();
 268 }
 269
 270 /*  Process the first arg in ARGS as the new exec file.
 271
 272    Note that we have to explicitly ignore additional args, since we can
 273    be called from file_command(), which also calls symbol_file_command()
 274    which can take multiple args.
 275
 276    If ARGS is NULL, we just want to close the exec file.  */
 277
 278 static void
 279 exec_file_command (char *args, int from_tty)
 280 {
 281   char **argv;
 282   char *filename;
 283
 284   if (from_tty && target_has_execution
 285       && !query (_("A program is being debugged already.\n"
 286                    "Are you sure you want to change the file? ")))
 287     error (_("File not changed."));
 288
 289   if (args)
 290     {
 291       struct cleanup *cleanups;
 292
 293       /* Scan through the args and pick up the first non option arg
 294          as the filename.  */
 295
 296       argv = gdb_buildargv (args);
 297       cleanups = make_cleanup_freeargv (argv);
 298
 299       for (; (*argv != NULL) && (**argv == '-'); argv++)
 300         {;
 301         }
 302       if (*argv == NULL)
 303         error (_("No executable file name was specified"));
 304
 305       filename = tilde_expand (*argv);
 306       make_cleanup (xfree, filename);
 307       exec_file_attach (filename, from_tty);
 308
 309       do_cleanups (cleanups);
 310     }
 311   else
 312     exec_file_attach (NULL, from_tty);
 313 }
 314
 315 /* Set both the exec file and the symbol file, in one command.
 316    What a novelty.  Why did GDB go through four major releases before this
 317    command was added?  */
 318
 319 static void
 320 file_command (char *arg, int from_tty)
 321 {
 322   /* FIXME, if we lose on reading the symbol file, we should revert
 323      the exec file, but that's rough.  */
 324   exec_file_command (arg, from_tty);
 325   symbol_file_command (arg, from_tty);
 326   if (deprecated_file_changed_hook)
 327     deprecated_file_changed_hook (arg);
 328 }
 329 \f
 330
 331 /* Locate all mappable sections of a BFD file.
 332    table_pp_char is a char * to get it through bfd_map_over_sections;
 333    we cast it back to its proper type.  */
 334
 335 static void
 336 add_to_section_table (bfd *abfd, struct bfd_section *asect,
 337                       void *table_pp_char)
 338 {
 339   struct target_section **table_pp = (struct target_section **) table_pp_char;
 340   flagword aflag;
 341
 342   gdb_assert (abfd == asect->owner);
 343
 344   /* Check the section flags, but do not discard zero-length sections, since
 345      some symbols may still be attached to this section.  For instance, we
 346      encountered on sparc-solaris 2.10 a shared library with an empty .bss
 347      section to which a symbol named "_end" was attached.  The address
 348      of this symbol still needs to be relocated.  */
 349   aflag = bfd_get_section_flags (abfd, asect);
 350   if (!(aflag & SEC_ALLOC))
 351     return;
 352
 353   (*table_pp)->owner = NULL;
 354   (*table_pp)->the_bfd_section = asect;
 355   (*table_pp)->addr = bfd_section_vma (abfd, asect);
 356   (*table_pp)->endaddr = (*table_pp)->addr + bfd_section_size (abfd, asect);
 357   (*table_pp)++;
 358 }
 359
 360 int
 361 resize_section_table (struct target_section_table *table, int num_added)
 362 {
 363   int old_count;
 364   int new_count;
 365
 366   old_count = table->sections_end - table->sections;
 367
 368   new_count = num_added + old_count;
 369
 370   if (new_count)
 371     {
 372       table->sections = xrealloc (table->sections,
 373                                   sizeof (struct target_section) * new_count);
 374       table->sections_end = table->sections + new_count;
 375     }
 376   else
 377     {
 378       xfree (table->sections);
 379       table->sections = table->sections_end = NULL;
 380     }
 381
 382   return old_count;
 383 }
 384
 385 /* Builds a section table, given args BFD, SECTABLE_PTR, SECEND_PTR.
 386    Returns 0 if OK, 1 on error.  */
 387
 388 int
 389 build_section_table (struct bfd *some_bfd, struct target_section **start,
 390                      struct target_section **end)
 391 {
 392   unsigned count;
 393
 394   count = bfd_count_sections (some_bfd);
 395   if (*start)
 396     xfree (* start);
 397   *start = (struct target_section *) xmalloc (count * sizeof (**start));
 398   *end = *start;
 399   bfd_map_over_sections (some_bfd, add_to_section_table, (char *) end);
 400   if (*end > *start + count)
 401     internal_error (__FILE__, __LINE__,
 402                     _("failed internal consistency check"));
 403   /* We could realloc the table, but it probably loses for most files.  */
 404   return 0;
 405 }
 406
 407 /* Add the sections array defined by [SECTIONS..SECTIONS_END[ to the
 408    current set of target sections.  */
 409
 410 void
 411 add_target_sections (void *owner,
 412                      struct target_section *sections,
 413                      struct target_section *sections_end)
 414 {
 415   int count;
 416   struct target_section_table *table = current_target_sections;
 417
 418   count = sections_end - sections;
 419
 420   if (count > 0)
 421     {
 422       int space = resize_section_table (table, count);
 423       int i;
 424
 425       for (i = 0; i < count; ++i)
 426         {
 427           table->sections[space + i] = sections[i];
 428           table->sections[space + i].owner = owner;
 429         }
 430
 431       /* If these are the first file sections we can provide memory
 432          from, push the file_stratum target.  */
 433       if (!using_exec_ops)
 434         {
 435           using_exec_ops = 1;
 436           push_target (&exec_ops);
 437         }
 438     }
 439 }
 440
 441 /* Remove all target sections owned by OWNER.
 442    OWNER must be the same value passed to add_target_sections.  */
 443
 444 void
 445 remove_target_sections (void *owner)
 446 {
 447   struct target_section *src, *dest;
 448   struct target_section_table *table = current_target_sections;
 449
 450   gdb_assert (owner != NULL);
 451
 452   dest = table->sections;
 453   for (src = table->sections; src < table->sections_end; src++)
 454     if (src->owner != owner)
 455       {
 456         /* Keep this section.  */
 457         if (dest < src)
 458           *dest = *src;
 459         dest++;
 460       }
 461
 462   /* If we've dropped any sections, resize the section table.  */
 463   if (dest < src)
 464     {
 465       int old_count;
 466
 467       old_count = resize_section_table (table, dest - src);
 468
 469       /* If we don't have any more sections to read memory from,
 470          remove the file_stratum target from the stack.  */
 471       if (old_count + (dest - src) == 0)
 472         {
 473           struct program_space *pspace;
 474
 475           ALL_PSPACES (pspace)
 476             if (pspace->target_sections.sections
 477                 != pspace->target_sections.sections_end)
 478               return;
 479
 480           unpush_target (&exec_ops);
 481         }
 482     }
 483 }
 484
 485 \f
 486
 487 VEC(mem_range_s) *
 488 section_table_available_memory (VEC(mem_range_s) *memory,
 489                                 CORE_ADDR memaddr, ULONGEST len,
 490                                 struct target_section *sections,
 491                                 struct target_section *sections_end)
 492 {
 493   struct target_section *p;
 494
 495   for (p = sections; p < sections_end; p++)
 496     {
 497       if ((bfd_get_section_flags (p->the_bfd_section->owner,
 498                                   p->the_bfd_section)
 499            & SEC_READONLY) == 0)
 500         continue;
 501
 502       /* Copy the meta-data, adjusted.  */
 503       if (mem_ranges_overlap (p->addr, p->endaddr - p->addr, memaddr, len))
 504         {
 505           ULONGEST lo1, hi1, lo2, hi2;
 506           struct mem_range *r;
 507
 508           lo1 = memaddr;
 509           hi1 = memaddr + len;
 510
 511           lo2 = p->addr;
 512           hi2 = p->endaddr;
 513
 514           r = VEC_safe_push (mem_range_s, memory, NULL);
 515
 516           r->start = max (lo1, lo2);
 517           r->length = min (hi1, hi2) - r->start;
 518         }
 519     }
 520
 521   return memory;
 522 }
 523
 524 int
 525 section_table_xfer_memory_partial (gdb_byte *readbuf, const gdb_byte *writebuf,
 526                                    ULONGEST offset, LONGEST len,
 527                                    struct target_section *sections,
 528                                    struct target_section *sections_end,
 529                                    const char *section_name)
 530 {
 531   int res;
 532   struct target_section *p;
 533   ULONGEST memaddr = offset;
 534   ULONGEST memend = memaddr + len;
 535
 536   if (len <= 0)
 537     internal_error (__FILE__, __LINE__,
 538                     _("failed internal consistency check"));
 539
 540   for (p = sections; p < sections_end; p++)
 541     {
 542       struct bfd_section *asect = p->the_bfd_section;
 543       bfd *abfd = asect->owner;
 544
 545       if (section_name && strcmp (section_name, asect->name) != 0)
 546         continue;               /* not the section we need.  */
 547       if (memaddr >= p->addr)
 548         {
 549           if (memend <= p->endaddr)
 550             {
 551               /* Entire transfer is within this section.  */
 552               if (writebuf)
 553                 res = bfd_set_section_contents (abfd, asect,
 554                                                 writebuf, memaddr - p->addr,
 555                                                 len);
 556               else
 557                 res = bfd_get_section_contents (abfd, asect,
 558                                                 readbuf, memaddr - p->addr,
 559                                                 len);
 560               return (res != 0) ? len : 0;
 561             }
 562           else if (memaddr >= p->endaddr)
 563             {
 564               /* This section ends before the transfer starts.  */
 565               continue;
 566             }
 567           else
 568             {
 569               /* This section overlaps the transfer.  Just do half.  */
 570               len = p->endaddr - memaddr;
 571               if (writebuf)
 572                 res = bfd_set_section_contents (abfd, asect,
 573                                                 writebuf, memaddr - p->addr,
 574                                                 len);
 575               else
 576                 res = bfd_get_section_contents (abfd, asect,
 577                                                 readbuf, memaddr - p->addr,
 578                                                 len);
 579               return (res != 0) ? len : 0;
 580             }
 581         }
 582     }
 583
 584   return 0;                     /* We can't help.  */
 585 }
 586
 587 static struct target_section_table *
 588 exec_get_section_table (struct target_ops *ops)
 589 {
 590   return current_target_sections;
 591 }
 592
 593 static LONGEST
 594 exec_xfer_partial (struct target_ops *ops, enum target_object object,
 595                    const char *annex, gdb_byte *readbuf,
 596                    const gdb_byte *writebuf,
 597                    ULONGEST offset, LONGEST len)
 598 {
 599   struct target_section_table *table = target_get_section_table (ops);
 600
 601   if (object == TARGET_OBJECT_MEMORY)
 602     return section_table_xfer_memory_partial (readbuf, writebuf,
 603                                               offset, len,
 604                                               table->sections,
 605                                               table->sections_end,
 606                                               NULL);
 607   else
 608     return -1;
 609 }
 610 \f
 611
 612 void
 613 print_section_info (struct target_section_table *t, bfd *abfd)
 614 {
 615   struct gdbarch *gdbarch = gdbarch_from_bfd (abfd);
 616   struct target_section *p;
 617   /* FIXME: 16 is not wide enough when gdbarch_addr_bit > 64.  */
 618   int wid = gdbarch_addr_bit (gdbarch) <= 32 ? 8 : 16;
 619
 620   printf_filtered ("\t`%s', ", bfd_get_filename (abfd));
 621   wrap_here ("        ");
 622   printf_filtered (_("file type %s.\n"), bfd_get_target (abfd));
 623   if (abfd == exec_bfd)
 624     {
 625       /* gcc-3.4 does not like the initialization in
 626          <p == t->sections_end>.  */
 627       bfd_vma displacement = 0;
 628       bfd_vma entry_point;
 629
 630       for (p = t->sections; p < t->sections_end; p++)
 631         {
 632           struct bfd_section *psect = p->the_bfd_section;
 633           bfd *pbfd = psect->owner;
 634
 635           if ((bfd_get_section_flags (pbfd, psect) & (SEC_ALLOC | SEC_LOAD))
 636               != (SEC_ALLOC | SEC_LOAD))
 637             continue;
 638
 639           if (bfd_get_section_vma (pbfd, psect) <= abfd->start_address
 640               && abfd->start_address < (bfd_get_section_vma (pbfd, psect)
 641                                         + bfd_get_section_size (psect)))
 642             {
 643               displacement = p->addr - bfd_get_section_vma (pbfd, psect);
 644               break;
 645             }
 646         }
 647       if (p == t->sections_end)
 648         warning (_("Cannot find section for the entry point of %s."),
 649                  bfd_get_filename (abfd));
 650
 651       entry_point = gdbarch_addr_bits_remove (gdbarch,
 652                                               bfd_get_start_address (abfd)
 653                                                 + displacement);
 654       printf_filtered (_("\tEntry point: %s\n"),
 655                        paddress (gdbarch, entry_point));
 656     }
 657   for (p = t->sections; p < t->sections_end; p++)
 658     {
 659       struct bfd_section *psect = p->the_bfd_section;
 660       bfd *pbfd = psect->owner;
 661
 662       printf_filtered ("\t%s", hex_string_custom (p->addr, wid));
 663       printf_filtered (" - %s", hex_string_custom (p->endaddr, wid));
 664
 665       /* FIXME: A format of "08l" is not wide enough for file offsets
 666          larger than 4GB.  OTOH, making it "016l" isn't desirable either
 667          since most output will then be much wider than necessary.  It
 668          may make sense to test the size of the file and choose the
 669          format string accordingly.  */
 670       /* FIXME: i18n: Need to rewrite this sentence.  */
 671       if (info_verbose)
 672         printf_filtered (" @ %s",
 673                          hex_string_custom (psect->filepos, 8));
 674       printf_filtered (" is %s", bfd_section_name (pbfd, psect));
 675       if (pbfd != abfd)
 676         printf_filtered (" in %s", bfd_get_filename (pbfd));
 677       printf_filtered ("\n");
 678     }
 679 }
 680
 681 static void
 682 exec_files_info (struct target_ops *t)
 683 {
 684   if (exec_bfd)
 685     print_section_info (current_target_sections, exec_bfd);
 686   else
 687     puts_filtered (_("\t<no file loaded>\n"));
 688 }
 689
 690 static void
 691 set_section_command (char *args, int from_tty)
 692 {
 693   struct target_section *p;
 694   char *secname;
 695   unsigned seclen;
 696   unsigned long secaddr;
 697   char secprint[100];
 698   long offset;
 699   struct target_section_table *table;
 700
 701   if (args == 0)
 702     error (_("Must specify section name and its virtual address"));
 703
 704   /* Parse out section name.  */
 705   for (secname = args; !isspace (*args); args++);
 706   seclen = args - secname;
 707
 708   /* Parse out new virtual address.  */
 709   secaddr = parse_and_eval_address (args);
 710
 711   table = current_target_sections;
 712   for (p = table->sections; p < table->sections_end; p++)
 713     {
 714       if (!strncmp (secname, bfd_section_name (p->bfd,
 715                                                p->the_bfd_section), seclen)
 716           && bfd_section_name (p->bfd, p->the_bfd_section)[seclen] == '\0')
 717         {
 718           offset = secaddr - p->addr;
 719           p->addr += offset;
 720           p->endaddr += offset;
 721           if (from_tty)
 722             exec_files_info (&exec_ops);
 723           return;
 724         }
 725     }
 726   if (seclen >= sizeof (secprint))
 727     seclen = sizeof (secprint) - 1;
 728   strncpy (secprint, secname, seclen);
 729   secprint[seclen] = '\0';
 730   error (_("Section %s not found"), secprint);
 731 }
 732
 733 /* If we can find a section in FILENAME with BFD index INDEX, adjust
 734    it to ADDRESS.  */
 735
 736 void
 737 exec_set_section_address (const char *filename, int index, CORE_ADDR address)
 738 {
 739   struct target_section *p;
 740   struct target_section_table *table;
 741
 742   table = current_target_sections;
 743   for (p = table->sections; p < table->sections_end; p++)
 744     {
 745       if (filename_cmp (filename, p->the_bfd_section->owner->filename) == 0
 746           && index == p->the_bfd_section->index)
 747         {
 748           p->endaddr += address - p->addr;
 749           p->addr = address;
 750         }
 751     }
 752 }
 753
 754 /* If mourn is being called in all the right places, this could be say
 755    `gdb internal error' (since generic_mourn calls
 756    breakpoint_init_inferior).  */
 757
 758 static int
 759 ignore (struct gdbarch *gdbarch, struct bp_target_info *bp_tgt)
 760 {
 761   return 0;
 762 }
 763
 764 static int
 765 exec_has_memory (struct target_ops *ops)
 766 {
 767   /* We can provide memory if we have any file/target sections to read
 768      from.  */
 769   return (current_target_sections->sections
 770           != current_target_sections->sections_end);
 771 }
 772
 773 /* Find mapped memory.  */
 774
 775 extern void
 776 exec_set_find_memory_regions (int (*func) (find_memory_region_ftype, void *))
 777 {
 778   exec_ops.to_find_memory_regions = func;
 779 }
 780
 781 static char *exec_make_note_section (bfd *, int *);
 782
 783 /* Fill in the exec file target vector.  Very few entries need to be
 784    defined.  */
 785
 786 static void
 787 init_exec_ops (void)
 788 {
 789   exec_ops.to_shortname = "exec";
 790   exec_ops.to_longname = "Local exec file";
 791   exec_ops.to_doc = "Use an executable file as a target.\n\
 792 Specify the filename of the executable file.";
 793   exec_ops.to_open = exec_open;
 794   exec_ops.to_close = exec_close_1;
 795   exec_ops.to_attach = find_default_attach;
 796   exec_ops.to_xfer_partial = exec_xfer_partial;
 797   exec_ops.to_get_section_table = exec_get_section_table;
 798   exec_ops.to_files_info = exec_files_info;
 799   exec_ops.to_insert_breakpoint = ignore;
 800   exec_ops.to_remove_breakpoint = ignore;
 801   exec_ops.to_create_inferior = find_default_create_inferior;
 802   exec_ops.to_stratum = file_stratum;
 803   exec_ops.to_has_memory = exec_has_memory;
 804   exec_ops.to_make_corefile_notes = exec_make_note_section;
 805   exec_ops.to_magic = OPS_MAGIC;
 806 }
 807
 808 void
 809 _initialize_exec (void)
 810 {
 811   struct cmd_list_element *c;
 812
 813   init_exec_ops ();
 814
 815   if (!dbx_commands)
 816     {
 817       c = add_cmd ("file", class_files, file_command, _("\
 818 Use FILE as program to be debugged.\n\
 819 It is read for its symbols, for getting the contents of pure memory,\n\
 820 and it is the program executed when you use the `run' command.\n\
 821 If FILE cannot be found as specified, your execution directory path\n\
 822 ($PATH) is searched for a command of that name.\n\
 823 No arg means to have no executable file and no symbols."), &cmdlist);
 824       set_cmd_completer (c, filename_completer);
 825     }
 826
 827   c = add_cmd ("exec-file", class_files, exec_file_command, _("\
 828 Use FILE as program for getting contents of pure memory.\n\
 829 If FILE cannot be found as specified, your execution directory path\n\
 830 is searched for a command of that name.\n\
 831 No arg means have no executable file."), &cmdlist);
 832   set_cmd_completer (c, filename_completer);
 833
 834   add_com ("section", class_files, set_section_command, _("\
 835 Change the base address of section SECTION of the exec file to ADDR.\n\
 836 This can be used if the exec file does not contain section addresses,\n\
 837 (such as in the a.out format), or when the addresses specified in the\n\
 838 file itself are wrong.  Each section must be changed separately.  The\n\
 839 ``info files'' command lists all the sections and their addresses."));
 840
 841   add_setshow_boolean_cmd ("write", class_support, &write_files, _("\
 842 Set writing into executable and core files."), _("\
 843 Show writing into executable and core files."), NULL,
 844                            NULL,
 845                            show_write_files,
 846                            &setlist, &showlist);
 847
 848   add_target_with_completer (&exec_ops, filename_completer);
 849 }
 850
 851 static char *
 852 exec_make_note_section (bfd *obfd, int *note_size)
 853 {
 854   error (_("Can't create a corefile"));
 855 }