gdb/arch-utils.c

   1 /* Dynamic architecture support for GDB, the GNU debugger.
   2    Copyright 1998-1999, 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 <ctype.h>
  31 #include "symtab.h"
  32 #include "frame.h"
  33 #include "inferior.h"
  34 #include "breakpoint.h"
  35 #include "gdb_wait.h"
  36 #include "gdbcore.h"
  37 #include "gdbcmd.h"
  38 #include "target.h"
  39 #include "gdbthread.h"
  40 #include "annotate.h"
  41 #include "symfile.h"            /* for overlay functions */
  42 #endif
  43
  44 #include "version.h"
  45
  46 #include "floatformat.h"
  47
  48 /* Convenience macro for allocting typesafe memory. */
  49
  50 #ifndef XMALLOC
  51 #define XMALLOC(TYPE) (TYPE*) xmalloc (sizeof (TYPE))
  52 #endif
  53
  54
  55 /* Use the program counter to determine the contents and size
  56    of a breakpoint instruction.  If no target-dependent macro
  57    BREAKPOINT_FROM_PC has been defined to implement this function,
  58    assume that the breakpoint doesn't depend on the PC, and
  59    use the values of the BIG_BREAKPOINT and LITTLE_BREAKPOINT macros.
  60    Return a pointer to a string of bytes that encode a breakpoint
  61    instruction, stores the length of the string to *lenptr,
  62    and optionally adjust the pc to point to the correct memory location
  63    for inserting the breakpoint.  */
  64
  65 unsigned char *
  66 legacy_breakpoint_from_pc (CORE_ADDR * pcptr, int *lenptr)
  67 {
  68   /* {BIG_,LITTLE_}BREAKPOINT is the sequence of bytes we insert for a
  69      breakpoint.  On some machines, breakpoints are handled by the
  70      target environment and we don't have to worry about them here.  */
  71 #ifdef BIG_BREAKPOINT
  72   if (TARGET_BYTE_ORDER == BIG_ENDIAN)
  73     {
  74       static unsigned char big_break_insn[] = BIG_BREAKPOINT;
  75       *lenptr = sizeof (big_break_insn);
  76       return big_break_insn;
  77     }
  78 #endif
  79 #ifdef LITTLE_BREAKPOINT
  80   if (TARGET_BYTE_ORDER != BIG_ENDIAN)
  81     {
  82       static unsigned char little_break_insn[] = LITTLE_BREAKPOINT;
  83       *lenptr = sizeof (little_break_insn);
  84       return little_break_insn;
  85     }
  86 #endif
  87 #ifdef BREAKPOINT
  88   {
  89     static unsigned char break_insn[] = BREAKPOINT;
  90     *lenptr = sizeof (break_insn);
  91     return break_insn;
  92   }
  93 #endif
  94   *lenptr = 0;
  95   return NULL;
  96 }
  97
  98 int
  99 generic_frameless_function_invocation_not (struct frame_info *fi)
 100 {
 101   return 0;
 102 }
 103
 104 int
 105 generic_return_value_on_stack_not (struct type *type)
 106 {
 107   return 0;
 108 }
 109
 110 char *
 111 legacy_register_name (int i)
 112 {
 113 #ifdef REGISTER_NAMES
 114   static char *names[] = REGISTER_NAMES;
 115   if (i < 0 || i >= (sizeof (names) / sizeof (*names)))
 116     return NULL;
 117   else
 118     return names[i];
 119 #else
 120   internal_error ("legacy_register_name: called.");
 121   return NULL;
 122 #endif
 123 }
 124
 125 #if defined (CALL_DUMMY)
 126 LONGEST legacy_call_dummy_words[] = CALL_DUMMY;
 127 #else
 128 LONGEST legacy_call_dummy_words[1];
 129 #endif
 130 int legacy_sizeof_call_dummy_words = sizeof (legacy_call_dummy_words);
 131
 132 void
 133 generic_remote_translate_xfer_address (CORE_ADDR gdb_addr, int gdb_len,
 134                                        CORE_ADDR * rem_addr, int *rem_len)
 135 {
 136   *rem_addr = gdb_addr;
 137   *rem_len = gdb_len;
 138 }
 139
 140 int
 141 generic_prologue_frameless_p (CORE_ADDR ip)
 142 {
 143 #ifdef SKIP_PROLOGUE_FRAMELESS_P
 144   return ip == SKIP_PROLOGUE_FRAMELESS_P (ip);
 145 #else
 146   return ip == SKIP_PROLOGUE (ip);
 147 #endif
 148 }
 149
 150
 151 /* Helper functions for INNER_THAN */
 152
 153 int
 154 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 155 {
 156   return (lhs < rhs);
 157 }
 158
 159 int
 160 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 161 {
 162   return (lhs > rhs);
 163 }
 164
 165
 166 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 167
 168 const struct floatformat *
 169 default_float_format (struct gdbarch *gdbarch)
 170 {
 171 #if GDB_MULTI_ARCH
 172   int byte_order = gdbarch_byte_order (gdbarch);
 173 #else
 174   int byte_order = TARGET_BYTE_ORDER;
 175 #endif
 176   switch (byte_order)
 177     {
 178     case BIG_ENDIAN:
 179       return &floatformat_ieee_single_big;
 180     case LITTLE_ENDIAN:
 181       return &floatformat_ieee_single_little;
 182     default:
 183       internal_error ("default_float_format: bad byte order");
 184     }
 185 }
 186
 187
 188 const struct floatformat *
 189 default_double_format (struct gdbarch *gdbarch)
 190 {
 191 #if GDB_MULTI_ARCH
 192   int byte_order = gdbarch_byte_order (gdbarch);
 193 #else
 194   int byte_order = TARGET_BYTE_ORDER;
 195 #endif
 196   switch (byte_order)
 197     {
 198     case BIG_ENDIAN:
 199       return &floatformat_ieee_double_big;
 200     case LITTLE_ENDIAN:
 201       return &floatformat_ieee_double_little;
 202     default:
 203       internal_error ("default_double_format: bad byte order");
 204     }
 205 }
 206
 207 /* Misc helper functions for targets. */
 208
 209 int
 210 frame_num_args_unknown (struct frame_info *fi)
 211 {
 212   return -1;
 213 }
 214
 215
 216 int
 217 generic_register_convertible_not (int num)
 218 {
 219   return 0;
 220 }
 221
 222
 223 int
 224 default_register_sim_regno (int num)
 225 {
 226   return num;
 227 }
 228
 229 /* Functions to manipulate the endianness of the target.  */
 230
 231 #ifdef TARGET_BYTE_ORDER_SELECTABLE
 232 /* compat - Catch old targets that expect a selectable byte-order to
 233    default to BIG_ENDIAN */
 234 #ifndef TARGET_BYTE_ORDER_DEFAULT
 235 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN
 236 #endif
 237 #endif
 238 #if !TARGET_BYTE_ORDER_SELECTABLE_P
 239 #ifndef TARGET_BYTE_ORDER_DEFAULT
 240 /* compat - Catch old non byte-order selectable targets that do not
 241    define TARGET_BYTE_ORDER_DEFAULT and instead expect
 242    TARGET_BYTE_ORDER to be used as the default.  For targets that
 243    defined neither TARGET_BYTE_ORDER nor TARGET_BYTE_ORDER_DEFAULT the
 244    below will get a strange compiler warning. */
 245 #define TARGET_BYTE_ORDER_DEFAULT TARGET_BYTE_ORDER
 246 #endif
 247 #endif
 248 #ifndef TARGET_BYTE_ORDER_DEFAULT
 249 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN /* arbitrary */
 250 #endif
 251 /* ``target_byte_order'' is only used when non- multi-arch.
 252    Multi-arch targets obtain the current byte order using
 253    TARGET_BYTE_ORDER which is controlled by gdbarch.*. */
 254 int target_byte_order = TARGET_BYTE_ORDER_DEFAULT;
 255 int target_byte_order_auto = 1;
 256
 257 static const char endian_big[] = "big";
 258 static const char endian_little[] = "little";
 259 static const char endian_auto[] = "auto";
 260 static const char *endian_enum[] =
 261 {
 262   endian_big,
 263   endian_little,
 264   endian_auto,
 265   NULL,
 266 };
 267 static const char *set_endian_string;
 268
 269 /* Called by ``show endian''.  */
 270
 271 static void
 272 show_endian (char *args, int from_tty)
 273 {
 274   if (TARGET_BYTE_ORDER_AUTO)
 275     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 276                        (TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little"));
 277   else
 278     printf_unfiltered ("The target is assumed to be %s endian\n",
 279                        (TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little"));
 280 }
 281
 282 static void
 283 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 284 {
 285   if (!TARGET_BYTE_ORDER_SELECTABLE_P)
 286     {
 287       printf_unfiltered ("Byte order is not selectable.");
 288     }
 289   else if (set_endian_string == endian_auto)
 290     {
 291       target_byte_order_auto = 1;
 292     }
 293   else if (set_endian_string == endian_little)
 294     {
 295       target_byte_order_auto = 0;
 296       if (GDB_MULTI_ARCH)
 297         {
 298           struct gdbarch_info info;
 299           memset (&info, 0, sizeof info);
 300           info.byte_order = LITTLE_ENDIAN;
 301           if (! gdbarch_update_p (info))
 302             {
 303               printf_unfiltered ("Little endian target not supported by GDB\n");
 304             }
 305         }
 306       else
 307         {
 308           target_byte_order = LITTLE_ENDIAN;
 309         }
 310     }
 311   else if (set_endian_string == endian_big)
 312     {
 313       target_byte_order_auto = 0;
 314       if (GDB_MULTI_ARCH)
 315         {
 316           struct gdbarch_info info;
 317           memset (&info, 0, sizeof info);
 318           info.byte_order = BIG_ENDIAN;
 319           if (! gdbarch_update_p (info))
 320             {
 321               printf_unfiltered ("Big endian target not supported by GDB\n");
 322             }
 323         }
 324       else
 325         {
 326           target_byte_order = BIG_ENDIAN;
 327         }
 328     }
 329   else
 330     internal_error ("set_endian: bad value");
 331   show_endian (NULL, from_tty);
 332 }
 333
 334 /* Set the endianness from a BFD.  */
 335
 336 static void
 337 set_endian_from_file (bfd *abfd)
 338 {
 339   if (GDB_MULTI_ARCH)
 340     internal_error ("set_endian_from_file: not for multi-arch");
 341   if (TARGET_BYTE_ORDER_SELECTABLE_P)
 342     {
 343       int want;
 344
 345       if (bfd_big_endian (abfd))
 346         want = BIG_ENDIAN;
 347       else
 348         want = LITTLE_ENDIAN;
 349       if (TARGET_BYTE_ORDER_AUTO)
 350         target_byte_order = want;
 351       else if (TARGET_BYTE_ORDER != want)
 352         warning ("%s endian file does not match %s endian target.",
 353                  want == BIG_ENDIAN ? "big" : "little",
 354                  TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little");
 355     }
 356   else
 357     {
 358       if (bfd_big_endian (abfd)
 359           ? TARGET_BYTE_ORDER != BIG_ENDIAN
 360           : TARGET_BYTE_ORDER == BIG_ENDIAN)
 361         warning ("%s endian file does not match %s endian target.",
 362                  bfd_big_endian (abfd) ? "big" : "little",
 363                  TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little");
 364     }
 365 }
 366
 367
 368 /* Functions to manipulate the architecture of the target */
 369
 370 enum set_arch { set_arch_auto, set_arch_manual };
 371
 372 int target_architecture_auto = 1;
 373
 374 const char *set_architecture_string;
 375
 376 /* Old way of changing the current architecture. */
 377
 378 extern const struct bfd_arch_info bfd_default_arch_struct;
 379 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 380 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 381
 382 static int
 383 arch_ok (const struct bfd_arch_info *arch)
 384 {
 385   if (GDB_MULTI_ARCH)
 386     internal_error ("arch_ok: not multi-arched");
 387   /* Should be performing the more basic check that the binary is
 388      compatible with GDB. */
 389   /* Check with the target that the architecture is valid. */
 390   return (target_architecture_hook == NULL
 391           || target_architecture_hook (arch));
 392 }
 393
 394 static void
 395 set_arch (const struct bfd_arch_info *arch,
 396           enum set_arch type)
 397 {
 398   if (GDB_MULTI_ARCH)
 399     internal_error ("set_arch: not multi-arched");
 400   switch (type)
 401     {
 402     case set_arch_auto:
 403       if (!arch_ok (arch))
 404         warning ("Target may not support %s architecture",
 405                  arch->printable_name);
 406       target_architecture = arch;
 407       break;
 408     case set_arch_manual:
 409       if (!arch_ok (arch))
 410         {
 411           printf_unfiltered ("Target does not support `%s' architecture.\n",
 412                              arch->printable_name);
 413         }
 414       else
 415         {
 416           target_architecture_auto = 0;
 417           target_architecture = arch;
 418         }
 419       break;
 420     }
 421   if (gdbarch_debug)
 422     gdbarch_dump (current_gdbarch, gdb_stdlog);
 423 }
 424
 425 /* Set the architecture from arch/machine (deprecated) */
 426
 427 void
 428 set_architecture_from_arch_mach (enum bfd_architecture arch,
 429                                  unsigned long mach)
 430 {
 431   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 432   if (GDB_MULTI_ARCH)
 433     internal_error ("set_architecture_from_arch_mach: not multi-arched");
 434   if (wanted != NULL)
 435     set_arch (wanted, set_arch_manual);
 436   else
 437     internal_error ("gdbarch: hardwired architecture/machine not reconized");
 438 }
 439
 440 /* Set the architecture from a BFD (deprecated) */
 441
 442 static void
 443 set_architecture_from_file (bfd *abfd)
 444 {
 445   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 446   if (GDB_MULTI_ARCH)
 447     internal_error ("set_architecture_from_file: not multi-arched");
 448   if (target_architecture_auto)
 449     {
 450       set_arch (wanted, set_arch_auto);
 451     }
 452   else if (wanted != target_architecture)
 453     {
 454       warning ("%s architecture file may be incompatible with %s target.",
 455                wanted->printable_name,
 456                target_architecture->printable_name);
 457     }
 458 }
 459
 460
 461 /* Called if the user enters ``show architecture'' without an
 462    argument. */
 463
 464 static void
 465 show_architecture (char *args, int from_tty)
 466 {
 467   const char *arch;
 468   arch = TARGET_ARCHITECTURE->printable_name;
 469   if (target_architecture_auto)
 470     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 471   else
 472     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 473 }
 474
 475
 476 /* Called if the user enters ``set architecture'' with or without an
 477    argument. */
 478
 479 static void
 480 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 481 {
 482   if (strcmp (set_architecture_string, "auto") == 0)
 483     {
 484       target_architecture_auto = 1;
 485     }
 486   else if (GDB_MULTI_ARCH)
 487     {
 488       struct gdbarch_info info;
 489       memset (&info, 0, sizeof info);
 490       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 491       if (info.bfd_arch_info == NULL)
 492         internal_error ("set_architecture: bfd_scan_arch failed");
 493       if (gdbarch_update_p (info))
 494         target_architecture_auto = 0;
 495       else
 496         printf_unfiltered ("Architecture `%s' not reconized.\n",
 497                            set_architecture_string);
 498     }
 499   else
 500     {
 501       const struct bfd_arch_info *arch
 502         = bfd_scan_arch (set_architecture_string);
 503       if (arch == NULL)
 504         internal_error ("set_architecture: bfd_scan_arch failed");
 505       set_arch (arch, set_arch_manual);
 506     }
 507   show_architecture (NULL, from_tty);
 508 }
 509
 510 /* Called if the user enters ``info architecture'' without an argument. */
 511
 512 static void
 513 info_architecture (char *args, int from_tty)
 514 {
 515   printf_filtered ("Available architectures are:\n");
 516   if (GDB_MULTI_ARCH)
 517     {
 518       const char **arches = gdbarch_printable_names ();
 519       const char **arch;
 520       for (arch = arches; *arch != NULL; arch++)
 521         {
 522           printf_filtered (" %s", *arch);
 523         }
 524       free (arches);
 525     }
 526   else
 527     {
 528       enum bfd_architecture a;
 529       for (a = bfd_arch_obscure + 1; a < bfd_arch_last; a++)
 530         {
 531           const struct bfd_arch_info *ap;
 532           for (ap = bfd_lookup_arch (a, 0);
 533                ap != NULL;
 534                ap = ap->next)
 535             {
 536               printf_filtered (" %s", ap->printable_name);
 537               ap = ap->next;
 538             }
 539         }
 540     }
 541   printf_filtered ("\n");
 542 }
 543
 544 /* Set the dynamic target-system-dependant parameters (architecture,
 545    byte-order) using information found in the BFD */
 546
 547 void
 548 set_gdbarch_from_file (bfd *abfd)
 549 {
 550   if (GDB_MULTI_ARCH)
 551     {
 552       struct gdbarch_info info;
 553       memset (&info, 0, sizeof info);
 554       info.abfd = abfd;
 555       if (! gdbarch_update_p (info))
 556         error ("Architecture of file not reconized.\n");
 557     }
 558   else
 559     {
 560       set_architecture_from_file (abfd);
 561       set_endian_from_file (abfd);
 562     }
 563 }
 564
 565 /* Initialize the current architecture.  Update the ``set
 566    architecture'' command so that it specifies a list of valid
 567    architectures.  */
 568
 569 #ifdef DEFAULT_BFD_ARCH
 570 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 571 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 572 #else
 573 static const bfd_arch_info_type *default_bfd_arch;
 574 #endif
 575
 576 #ifdef DEFAULT_BFD_VEC
 577 extern const bfd_target DEFAULT_BFD_VEC;
 578 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 579 #else
 580 static const bfd_target *default_bfd_vec;
 581 #endif
 582
 583 void
 584 initialize_current_architecture (void)
 585 {
 586   const char **arches = gdbarch_printable_names ();
 587
 588   /* determine a default architecture and byte order. */
 589   struct gdbarch_info info;
 590   memset (&info, 0, sizeof (info));
 591
 592   /* Find a default architecture. */
 593   if (info.bfd_arch_info == NULL
 594       && default_bfd_arch != NULL)
 595     info.bfd_arch_info = default_bfd_arch;
 596   if (info.bfd_arch_info == NULL)
 597     {
 598       /* Choose the architecture by taking the first one
 599          alphabetically. */
 600       const char *chosen = arches[0];
 601       const char **arch;
 602       for (arch = arches; *arch != NULL; arch++)
 603         {
 604           if (strcmp (*arch, chosen) < 0)
 605             chosen = *arch;
 606         }
 607       if (chosen == NULL)
 608         internal_error ("initialize_current_architecture: No arch");
 609       info.bfd_arch_info = bfd_scan_arch (chosen);
 610       if (info.bfd_arch_info == NULL)
 611         internal_error ("initialize_current_architecture: Arch not found");
 612     }
 613
 614   /* take several guesses at a byte order. */
 615   /* NB: can't use TARGET_BYTE_ORDER_DEFAULT as its definition is
 616      forced above. */
 617   if (info.byte_order == 0
 618       && default_bfd_vec != NULL)
 619     {
 620       /* Extract BFD's default vector's byte order. */
 621       switch (default_bfd_vec->byteorder)
 622         {
 623         case BFD_ENDIAN_BIG:
 624           info.byte_order = BIG_ENDIAN;
 625           break;
 626         case BFD_ENDIAN_LITTLE:
 627           info.byte_order = LITTLE_ENDIAN;
 628           break;
 629         default:
 630           break;
 631         }
 632     }
 633   if (info.byte_order == 0)
 634     {
 635       /* look for ``*el-*'' in the target name. */
 636       const char *chp;
 637       chp = strchr (target_name, '-');
 638       if (chp != NULL
 639           && chp - 2 >= target_name
 640           && strncmp (chp - 2, "el", 2) == 0)
 641         info.byte_order = LITTLE_ENDIAN;
 642     }
 643   if (info.byte_order == 0)
 644     {
 645       /* Wire it to big-endian!!! */
 646       info.byte_order = BIG_ENDIAN;
 647     }
 648
 649   if (GDB_MULTI_ARCH)
 650     {
 651       if (! gdbarch_update_p (info))
 652         {
 653           internal_error ("initialize_current_architecture: Selection of initial architecture failed");
 654         }
 655     }
 656
 657   /* Create the ``set architecture'' command appending ``auto'' to the
 658      list of architectures. */
 659   {
 660     struct cmd_list_element *c;
 661     /* Append ``auto''. */
 662     int nr;
 663     for (nr = 0; arches[nr] != NULL; nr++);
 664     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 665     arches[nr + 0] = "auto";
 666     arches[nr + 1] = NULL;
 667     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 668        of ``const char *''.  We just happen to know that the casts are
 669        safe. */
 670     c = add_set_enum_cmd ("architecture", class_support,
 671                           arches, &set_architecture_string,
 672                           "Set architecture of target.",
 673                           &setlist);
 674     c->function.sfunc = set_architecture;
 675     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 676     /* Don't use set_from_show - need to print both auto/manual and
 677        current setting. */
 678     add_cmd ("architecture", class_support, show_architecture,
 679              "Show the current target architecture", &showlist);
 680     c = add_cmd ("architecture", class_support, info_architecture,
 681                  "List supported target architectures", &infolist);
 682     deprecate_cmd (c, "set architecture");
 683   }
 684 }
 685
 686
 687 /* */
 688
 689 extern initialize_file_ftype _initialize_gdbarch_utils;
 690
 691 void
 692 _initialize_gdbarch_utils (void)
 693 {
 694   struct cmd_list_element *c;
 695   c = add_set_enum_cmd ("endian", class_support,
 696                         endian_enum, &set_endian_string,
 697                         "Set endianness of target.",
 698                         &setlist);
 699   c->function.sfunc = set_endian;
 700   /* Don't use set_from_show - need to print both auto/manual and
 701      current setting. */
 702   add_cmd ("endian", class_support, show_endian,
 703            "Show the current byte-order", &showlist);
 704 }