gdb/arch-utils.c

   1 /* Dynamic architecture support for GDB, the GNU debugger.
   2    Copyright 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22
  23 #if GDB_MULTI_ARCH
  24 #include "gdbcmd.h"
  25 #include "inferior.h"           /* enum CALL_DUMMY_LOCATION et.al. */
  26 #else
  27 /* Just include everything in sight so that the every old definition
  28    of macro is visible. */
  29 #include "gdb_string.h"
  30 #include "symtab.h"
  31 #include "frame.h"
  32 #include "inferior.h"
  33 #include "breakpoint.h"
  34 #include "gdb_wait.h"
  35 #include "gdbcore.h"
  36 #include "gdbcmd.h"
  37 #include "target.h"
  38 #include "annotate.h"
  39 #endif
  40 #include "regcache.h"
  41 #include "gdb_assert.h"
  42
  43 #include "version.h"
  44
  45 #include "floatformat.h"
  46
  47 /* Use the program counter to determine the contents and size
  48    of a breakpoint instruction.  If no target-dependent macro
  49    BREAKPOINT_FROM_PC has been defined to implement this function,
  50    assume that the breakpoint doesn't depend on the PC, and
  51    use the values of the BIG_BREAKPOINT and LITTLE_BREAKPOINT macros.
  52    Return a pointer to a string of bytes that encode a breakpoint
  53    instruction, stores the length of the string to *lenptr,
  54    and optionally adjust the pc to point to the correct memory location
  55    for inserting the breakpoint.  */
  56
  57 unsigned char *
  58 legacy_breakpoint_from_pc (CORE_ADDR * pcptr, int *lenptr)
  59 {
  60   /* {BIG_,LITTLE_}BREAKPOINT is the sequence of bytes we insert for a
  61      breakpoint.  On some machines, breakpoints are handled by the
  62      target environment and we don't have to worry about them here.  */
  63 #ifdef BIG_BREAKPOINT
  64   if (TARGET_BYTE_ORDER == BIG_ENDIAN)
  65     {
  66       static unsigned char big_break_insn[] = BIG_BREAKPOINT;
  67       *lenptr = sizeof (big_break_insn);
  68       return big_break_insn;
  69     }
  70 #endif
  71 #ifdef LITTLE_BREAKPOINT
  72   if (TARGET_BYTE_ORDER != BIG_ENDIAN)
  73     {
  74       static unsigned char little_break_insn[] = LITTLE_BREAKPOINT;
  75       *lenptr = sizeof (little_break_insn);
  76       return little_break_insn;
  77     }
  78 #endif
  79 #ifdef BREAKPOINT
  80   {
  81     static unsigned char break_insn[] = BREAKPOINT;
  82     *lenptr = sizeof (break_insn);
  83     return break_insn;
  84   }
  85 #endif
  86   *lenptr = 0;
  87   return NULL;
  88 }
  89
  90 int
  91 generic_frameless_function_invocation_not (struct frame_info *fi)
  92 {
  93   return 0;
  94 }
  95
  96 int
  97 generic_return_value_on_stack_not (struct type *type)
  98 {
  99   return 0;
 100 }
 101
 102 CORE_ADDR
 103 generic_skip_trampoline_code (CORE_ADDR pc)
 104 {
 105   return 0;
 106 }
 107
 108 int
 109 generic_in_solib_call_trampoline (CORE_ADDR pc, char *name)
 110 {
 111   return 0;
 112 }
 113
 114 int
 115 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 116 {
 117   return 0;
 118 }
 119
 120 char *
 121 legacy_register_name (int i)
 122 {
 123 #ifdef REGISTER_NAMES
 124   static char *names[] = REGISTER_NAMES;
 125   if (i < 0 || i >= (sizeof (names) / sizeof (*names)))
 126     return NULL;
 127   else
 128     return names[i];
 129 #else
 130   internal_error (__FILE__, __LINE__,
 131                   "legacy_register_name: called.");
 132   return NULL;
 133 #endif
 134 }
 135
 136 #if defined (CALL_DUMMY)
 137 LONGEST legacy_call_dummy_words[] = CALL_DUMMY;
 138 #else
 139 LONGEST legacy_call_dummy_words[1];
 140 #endif
 141 int legacy_sizeof_call_dummy_words = sizeof (legacy_call_dummy_words);
 142
 143 void
 144 generic_remote_translate_xfer_address (CORE_ADDR gdb_addr, int gdb_len,
 145                                        CORE_ADDR * rem_addr, int *rem_len)
 146 {
 147   *rem_addr = gdb_addr;
 148   *rem_len = gdb_len;
 149 }
 150
 151 int
 152 generic_prologue_frameless_p (CORE_ADDR ip)
 153 {
 154 #ifdef SKIP_PROLOGUE_FRAMELESS_P
 155   return ip == SKIP_PROLOGUE_FRAMELESS_P (ip);
 156 #else
 157   return ip == SKIP_PROLOGUE (ip);
 158 #endif
 159 }
 160
 161 /* New/multi-arched targets should use the correct gdbarch field
 162    instead of using this global pointer. */
 163 int
 164 legacy_print_insn (bfd_vma vma, disassemble_info *info)
 165 {
 166   return (*tm_print_insn) (vma, info);
 167 }
 168
 169 /* Helper functions for INNER_THAN */
 170
 171 int
 172 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 173 {
 174   return (lhs < rhs);
 175 }
 176
 177 int
 178 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 179 {
 180   return (lhs > rhs);
 181 }
 182
 183
 184 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 185
 186 const struct floatformat *
 187 default_float_format (struct gdbarch *gdbarch)
 188 {
 189 #if GDB_MULTI_ARCH
 190   int byte_order = gdbarch_byte_order (gdbarch);
 191 #else
 192   int byte_order = TARGET_BYTE_ORDER;
 193 #endif
 194   switch (byte_order)
 195     {
 196     case BIG_ENDIAN:
 197       return &floatformat_ieee_single_big;
 198     case LITTLE_ENDIAN:
 199       return &floatformat_ieee_single_little;
 200     default:
 201       internal_error (__FILE__, __LINE__,
 202                       "default_float_format: bad byte order");
 203     }
 204 }
 205
 206
 207 const struct floatformat *
 208 default_double_format (struct gdbarch *gdbarch)
 209 {
 210 #if GDB_MULTI_ARCH
 211   int byte_order = gdbarch_byte_order (gdbarch);
 212 #else
 213   int byte_order = TARGET_BYTE_ORDER;
 214 #endif
 215   switch (byte_order)
 216     {
 217     case BIG_ENDIAN:
 218       return &floatformat_ieee_double_big;
 219     case LITTLE_ENDIAN:
 220       return &floatformat_ieee_double_little;
 221     default:
 222       internal_error (__FILE__, __LINE__,
 223                       "default_double_format: bad byte order");
 224     }
 225 }
 226
 227 /* Misc helper functions for targets. */
 228
 229 int
 230 frame_num_args_unknown (struct frame_info *fi)
 231 {
 232   return -1;
 233 }
 234
 235
 236 int
 237 generic_register_convertible_not (int num)
 238 {
 239   return 0;
 240 }
 241
 242
 243 int
 244 default_register_sim_regno (int num)
 245 {
 246   return num;
 247 }
 248
 249
 250 CORE_ADDR
 251 core_addr_identity (CORE_ADDR addr)
 252 {
 253   return addr;
 254 }
 255
 256 int
 257 no_op_reg_to_regnum (int reg)
 258 {
 259   return reg;
 260 }
 261
 262 /* For use by frame_args_address and frame_locals_address.  */
 263 CORE_ADDR
 264 default_frame_address (struct frame_info *fi)
 265 {
 266   return fi->frame;
 267 }
 268
 269 /* Default prepare_to_procced().  */
 270 int
 271 default_prepare_to_proceed (int select_it)
 272 {
 273   return 0;
 274 }
 275
 276 /* Generic prepare_to_proceed().  This one should be suitable for most
 277    targets that support threads. */
 278 int
 279 generic_prepare_to_proceed (int select_it)
 280 {
 281   ptid_t wait_ptid;
 282   struct target_waitstatus wait_status;
 283
 284   /* Get the last target status returned by target_wait().  */
 285   get_last_target_status (&wait_ptid, &wait_status);
 286
 287   /* Make sure we were stopped either at a breakpoint, or because
 288      of a Ctrl-C.  */
 289   if (wait_status.kind != TARGET_WAITKIND_STOPPED
 290       || (wait_status.value.sig != TARGET_SIGNAL_TRAP &&
 291           wait_status.value.sig != TARGET_SIGNAL_INT))
 292     {
 293       return 0;
 294     }
 295
 296   if (!ptid_equal (wait_ptid, minus_one_ptid)
 297       && !ptid_equal (inferior_ptid, wait_ptid))
 298     {
 299       /* Switched over from WAIT_PID.  */
 300       CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
 301
 302       if (wait_pc != read_pc ())
 303         {
 304           if (select_it)
 305             {
 306               /* Switch back to WAIT_PID thread.  */
 307               inferior_ptid = wait_ptid;
 308
 309               /* FIXME: This stuff came from switch_to_thread() in
 310                  thread.c (which should probably be a public function).  */
 311               flush_cached_frames ();
 312               registers_changed ();
 313               stop_pc = wait_pc;
 314               select_frame (get_current_frame (), 0);
 315             }
 316           /* We return 1 to indicate that there is a breakpoint here,
 317              so we need to step over it before continuing to avoid
 318              hitting it straight away. */
 319           if (breakpoint_here_p (wait_pc))
 320             {
 321               return 1;
 322             }
 323         }
 324     }
 325   return 0;
 326
 327 }
 328
 329 void
 330 init_frame_pc_noop (int fromleaf, struct frame_info *prev)
 331 {
 332   return;
 333 }
 334
 335 void
 336 init_frame_pc_default (int fromleaf, struct frame_info *prev)
 337 {
 338   if (fromleaf)
 339     prev->pc = SAVED_PC_AFTER_CALL (prev->next);
 340   else if (prev->next != NULL)
 341     prev->pc = FRAME_SAVED_PC (prev->next);
 342   else
 343     prev->pc = read_pc ();
 344 }
 345
 346 int
 347 cannot_register_not (int regnum)
 348 {
 349   return 0;
 350 }
 351
 352 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 353    there is an FP_REGNUM and that it is the same, cooked or raw.  */
 354
 355 void
 356 legacy_virtual_frame_pointer (CORE_ADDR pc,
 357                               int *frame_regnum,
 358                               LONGEST *frame_offset)
 359 {
 360   gdb_assert (FP_REGNUM >= 0);
 361   *frame_regnum = FP_REGNUM;
 362   *frame_offset = 0;
 363 }
 364 \f
 365 /* Functions to manipulate the endianness of the target.  */
 366
 367 #ifdef TARGET_BYTE_ORDER_SELECTABLE
 368 /* compat - Catch old targets that expect a selectable byte-order to
 369    default to BIG_ENDIAN */
 370 #ifndef TARGET_BYTE_ORDER_DEFAULT
 371 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN
 372 #endif
 373 #endif
 374 #if !TARGET_BYTE_ORDER_SELECTABLE_P
 375 #ifndef TARGET_BYTE_ORDER_DEFAULT
 376 /* compat - Catch old non byte-order selectable targets that do not
 377    define TARGET_BYTE_ORDER_DEFAULT and instead expect
 378    TARGET_BYTE_ORDER to be used as the default.  For targets that
 379    defined neither TARGET_BYTE_ORDER nor TARGET_BYTE_ORDER_DEFAULT the
 380    below will get a strange compiler warning. */
 381 #define TARGET_BYTE_ORDER_DEFAULT TARGET_BYTE_ORDER
 382 #endif
 383 #endif
 384 #ifndef TARGET_BYTE_ORDER_DEFAULT
 385 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN /* arbitrary */
 386 #endif
 387 /* ``target_byte_order'' is only used when non- multi-arch.
 388    Multi-arch targets obtain the current byte order using
 389    TARGET_BYTE_ORDER which is controlled by gdbarch.*. */
 390 int target_byte_order = TARGET_BYTE_ORDER_DEFAULT;
 391 int target_byte_order_auto = 1;
 392
 393 static const char endian_big[] = "big";
 394 static const char endian_little[] = "little";
 395 static const char endian_auto[] = "auto";
 396 static const char *endian_enum[] =
 397 {
 398   endian_big,
 399   endian_little,
 400   endian_auto,
 401   NULL,
 402 };
 403 static const char *set_endian_string;
 404
 405 /* Called by ``show endian''.  */
 406
 407 static void
 408 show_endian (char *args, int from_tty)
 409 {
 410   if (TARGET_BYTE_ORDER_AUTO)
 411     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 412                        (TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little"));
 413   else
 414     printf_unfiltered ("The target is assumed to be %s endian\n",
 415                        (TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little"));
 416 }
 417
 418 static void
 419 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 420 {
 421   if (!TARGET_BYTE_ORDER_SELECTABLE_P)
 422     {
 423       printf_unfiltered ("Byte order is not selectable.");
 424     }
 425   else if (set_endian_string == endian_auto)
 426     {
 427       target_byte_order_auto = 1;
 428     }
 429   else if (set_endian_string == endian_little)
 430     {
 431       target_byte_order_auto = 0;
 432       if (GDB_MULTI_ARCH)
 433         {
 434           struct gdbarch_info info;
 435           memset (&info, 0, sizeof info);
 436           info.byte_order = LITTLE_ENDIAN;
 437           if (! gdbarch_update_p (info))
 438             {
 439               printf_unfiltered ("Little endian target not supported by GDB\n");
 440             }
 441         }
 442       else
 443         {
 444           target_byte_order = LITTLE_ENDIAN;
 445         }
 446     }
 447   else if (set_endian_string == endian_big)
 448     {
 449       target_byte_order_auto = 0;
 450       if (GDB_MULTI_ARCH)
 451         {
 452           struct gdbarch_info info;
 453           memset (&info, 0, sizeof info);
 454           info.byte_order = BIG_ENDIAN;
 455           if (! gdbarch_update_p (info))
 456             {
 457               printf_unfiltered ("Big endian target not supported by GDB\n");
 458             }
 459         }
 460       else
 461         {
 462           target_byte_order = BIG_ENDIAN;
 463         }
 464     }
 465   else
 466     internal_error (__FILE__, __LINE__,
 467                     "set_endian: bad value");
 468   show_endian (NULL, from_tty);
 469 }
 470
 471 /* Set the endianness from a BFD.  */
 472
 473 static void
 474 set_endian_from_file (bfd *abfd)
 475 {
 476   if (GDB_MULTI_ARCH)
 477     internal_error (__FILE__, __LINE__,
 478                     "set_endian_from_file: not for multi-arch");
 479   if (TARGET_BYTE_ORDER_SELECTABLE_P)
 480     {
 481       int want;
 482
 483       if (bfd_big_endian (abfd))
 484         want = BIG_ENDIAN;
 485       else
 486         want = LITTLE_ENDIAN;
 487       if (TARGET_BYTE_ORDER_AUTO)
 488         target_byte_order = want;
 489       else if (TARGET_BYTE_ORDER != want)
 490         warning ("%s endian file does not match %s endian target.",
 491                  want == BIG_ENDIAN ? "big" : "little",
 492                  TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little");
 493     }
 494   else
 495     {
 496       if (bfd_big_endian (abfd)
 497           ? TARGET_BYTE_ORDER != BIG_ENDIAN
 498           : TARGET_BYTE_ORDER == BIG_ENDIAN)
 499         warning ("%s endian file does not match %s endian target.",
 500                  bfd_big_endian (abfd) ? "big" : "little",
 501                  TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little");
 502     }
 503 }
 504
 505
 506 /* Functions to manipulate the architecture of the target */
 507
 508 enum set_arch { set_arch_auto, set_arch_manual };
 509
 510 int target_architecture_auto = 1;
 511
 512 const char *set_architecture_string;
 513
 514 /* Old way of changing the current architecture. */
 515
 516 extern const struct bfd_arch_info bfd_default_arch_struct;
 517 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 518 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 519
 520 static int
 521 arch_ok (const struct bfd_arch_info *arch)
 522 {
 523   if (GDB_MULTI_ARCH)
 524     internal_error (__FILE__, __LINE__,
 525                     "arch_ok: not multi-arched");
 526   /* Should be performing the more basic check that the binary is
 527      compatible with GDB. */
 528   /* Check with the target that the architecture is valid. */
 529   return (target_architecture_hook == NULL
 530           || target_architecture_hook (arch));
 531 }
 532
 533 static void
 534 set_arch (const struct bfd_arch_info *arch,
 535           enum set_arch type)
 536 {
 537   if (GDB_MULTI_ARCH)
 538     internal_error (__FILE__, __LINE__,
 539                     "set_arch: not multi-arched");
 540   switch (type)
 541     {
 542     case set_arch_auto:
 543       if (!arch_ok (arch))
 544         warning ("Target may not support %s architecture",
 545                  arch->printable_name);
 546       target_architecture = arch;
 547       break;
 548     case set_arch_manual:
 549       if (!arch_ok (arch))
 550         {
 551           printf_unfiltered ("Target does not support `%s' architecture.\n",
 552                              arch->printable_name);
 553         }
 554       else
 555         {
 556           target_architecture_auto = 0;
 557           target_architecture = arch;
 558         }
 559       break;
 560     }
 561   if (gdbarch_debug)
 562     gdbarch_dump (current_gdbarch, gdb_stdlog);
 563 }
 564
 565 /* Set the architecture from arch/machine (deprecated) */
 566
 567 void
 568 set_architecture_from_arch_mach (enum bfd_architecture arch,
 569                                  unsigned long mach)
 570 {
 571   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 572   if (GDB_MULTI_ARCH)
 573     internal_error (__FILE__, __LINE__,
 574                     "set_architecture_from_arch_mach: not multi-arched");
 575   if (wanted != NULL)
 576     set_arch (wanted, set_arch_manual);
 577   else
 578     internal_error (__FILE__, __LINE__,
 579                     "gdbarch: hardwired architecture/machine not recognized");
 580 }
 581
 582 /* Set the architecture from a BFD (deprecated) */
 583
 584 static void
 585 set_architecture_from_file (bfd *abfd)
 586 {
 587   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 588   if (GDB_MULTI_ARCH)
 589     internal_error (__FILE__, __LINE__,
 590                     "set_architecture_from_file: not multi-arched");
 591   if (target_architecture_auto)
 592     {
 593       set_arch (wanted, set_arch_auto);
 594     }
 595   else if (wanted != target_architecture)
 596     {
 597       warning ("%s architecture file may be incompatible with %s target.",
 598                wanted->printable_name,
 599                target_architecture->printable_name);
 600     }
 601 }
 602
 603
 604 /* Called if the user enters ``show architecture'' without an
 605    argument. */
 606
 607 static void
 608 show_architecture (char *args, int from_tty)
 609 {
 610   const char *arch;
 611   arch = TARGET_ARCHITECTURE->printable_name;
 612   if (target_architecture_auto)
 613     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 614   else
 615     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 616 }
 617
 618
 619 /* Called if the user enters ``set architecture'' with or without an
 620    argument. */
 621
 622 static void
 623 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 624 {
 625   if (strcmp (set_architecture_string, "auto") == 0)
 626     {
 627       target_architecture_auto = 1;
 628     }
 629   else if (GDB_MULTI_ARCH)
 630     {
 631       struct gdbarch_info info;
 632       memset (&info, 0, sizeof info);
 633       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 634       if (info.bfd_arch_info == NULL)
 635         internal_error (__FILE__, __LINE__,
 636                         "set_architecture: bfd_scan_arch failed");
 637       if (gdbarch_update_p (info))
 638         target_architecture_auto = 0;
 639       else
 640         printf_unfiltered ("Architecture `%s' not recognized.\n",
 641                            set_architecture_string);
 642     }
 643   else
 644     {
 645       const struct bfd_arch_info *arch
 646         = bfd_scan_arch (set_architecture_string);
 647       if (arch == NULL)
 648         internal_error (__FILE__, __LINE__,
 649                         "set_architecture: bfd_scan_arch failed");
 650       set_arch (arch, set_arch_manual);
 651     }
 652   show_architecture (NULL, from_tty);
 653 }
 654
 655 /* Set the dynamic target-system-dependent parameters (architecture,
 656    byte-order) using information found in the BFD */
 657
 658 void
 659 set_gdbarch_from_file (bfd *abfd)
 660 {
 661   if (GDB_MULTI_ARCH)
 662     {
 663       struct gdbarch_info info;
 664       memset (&info, 0, sizeof info);
 665       info.abfd = abfd;
 666       if (! gdbarch_update_p (info))
 667         error ("Architecture of file not recognized.\n");
 668     }
 669   else
 670     {
 671       set_architecture_from_file (abfd);
 672       set_endian_from_file (abfd);
 673     }
 674 }
 675
 676 /* Initialize the current architecture.  Update the ``set
 677    architecture'' command so that it specifies a list of valid
 678    architectures.  */
 679
 680 #ifdef DEFAULT_BFD_ARCH
 681 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 682 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 683 #else
 684 static const bfd_arch_info_type *default_bfd_arch;
 685 #endif
 686
 687 #ifdef DEFAULT_BFD_VEC
 688 extern const bfd_target DEFAULT_BFD_VEC;
 689 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 690 #else
 691 static const bfd_target *default_bfd_vec;
 692 #endif
 693
 694 void
 695 initialize_current_architecture (void)
 696 {
 697   const char **arches = gdbarch_printable_names ();
 698
 699   /* determine a default architecture and byte order. */
 700   struct gdbarch_info info;
 701   memset (&info, 0, sizeof (info));
 702
 703   /* Find a default architecture. */
 704   if (info.bfd_arch_info == NULL
 705       && default_bfd_arch != NULL)
 706     info.bfd_arch_info = default_bfd_arch;
 707   if (info.bfd_arch_info == NULL)
 708     {
 709       /* Choose the architecture by taking the first one
 710          alphabetically. */
 711       const char *chosen = arches[0];
 712       const char **arch;
 713       for (arch = arches; *arch != NULL; arch++)
 714         {
 715           if (strcmp (*arch, chosen) < 0)
 716             chosen = *arch;
 717         }
 718       if (chosen == NULL)
 719         internal_error (__FILE__, __LINE__,
 720                         "initialize_current_architecture: No arch");
 721       info.bfd_arch_info = bfd_scan_arch (chosen);
 722       if (info.bfd_arch_info == NULL)
 723         internal_error (__FILE__, __LINE__,
 724                         "initialize_current_architecture: Arch not found");
 725     }
 726
 727   /* take several guesses at a byte order. */
 728   /* NB: can't use TARGET_BYTE_ORDER_DEFAULT as its definition is
 729      forced above. */
 730   if (info.byte_order == 0
 731       && default_bfd_vec != NULL)
 732     {
 733       /* Extract BFD's default vector's byte order. */
 734       switch (default_bfd_vec->byteorder)
 735         {
 736         case BFD_ENDIAN_BIG:
 737           info.byte_order = BIG_ENDIAN;
 738           break;
 739         case BFD_ENDIAN_LITTLE:
 740           info.byte_order = LITTLE_ENDIAN;
 741           break;
 742         default:
 743           break;
 744         }
 745     }
 746   if (info.byte_order == 0)
 747     {
 748       /* look for ``*el-*'' in the target name. */
 749       const char *chp;
 750       chp = strchr (target_name, '-');
 751       if (chp != NULL
 752           && chp - 2 >= target_name
 753           && strncmp (chp - 2, "el", 2) == 0)
 754         info.byte_order = LITTLE_ENDIAN;
 755     }
 756   if (info.byte_order == 0)
 757     {
 758       /* Wire it to big-endian!!! */
 759       info.byte_order = BIG_ENDIAN;
 760     }
 761
 762   if (GDB_MULTI_ARCH)
 763     {
 764       if (! gdbarch_update_p (info))
 765         {
 766           internal_error (__FILE__, __LINE__,
 767                           "initialize_current_architecture: Selection of initial architecture failed");
 768         }
 769     }
 770   else
 771     initialize_non_multiarch ();
 772
 773   /* Create the ``set architecture'' command appending ``auto'' to the
 774      list of architectures. */
 775   {
 776     struct cmd_list_element *c;
 777     /* Append ``auto''. */
 778     int nr;
 779     for (nr = 0; arches[nr] != NULL; nr++);
 780     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 781     arches[nr + 0] = "auto";
 782     arches[nr + 1] = NULL;
 783     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 784        of ``const char *''.  We just happen to know that the casts are
 785        safe. */
 786     c = add_set_enum_cmd ("architecture", class_support,
 787                           arches, &set_architecture_string,
 788                           "Set architecture of target.",
 789                           &setlist);
 790     c->function.sfunc = set_architecture;
 791     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 792     /* Don't use set_from_show - need to print both auto/manual and
 793        current setting. */
 794     add_cmd ("architecture", class_support, show_architecture,
 795              "Show the current target architecture", &showlist);
 796   }
 797 }
 798
 799
 800 /* */
 801
 802 extern initialize_file_ftype _initialize_gdbarch_utils;
 803
 804 void
 805 _initialize_gdbarch_utils (void)
 806 {
 807   struct cmd_list_element *c;
 808   c = add_set_enum_cmd ("endian", class_support,
 809                         endian_enum, &set_endian_string,
 810                         "Set endianness of target.",
 811                         &setlist);
 812   c->function.sfunc = set_endian;
 813   /* Don't use set_from_show - need to print both auto/manual and
 814      current setting. */
 815   add_cmd ("endian", class_support, show_endian,
 816            "Show the current byte-order", &showlist);
 817 }