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