gdb/arch-utils.c

   1 /* Dynamic architecture support for GDB, the GNU debugger.
   2
   3    Copyright 1998, 1999, 2000, 2001, 2002 Free Software Foundation,
   4    Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "defs.h"
  24
  25 #if GDB_MULTI_ARCH
  26 #include "arch-utils.h"
  27 #include "gdbcmd.h"
  28 #include "inferior.h"           /* enum CALL_DUMMY_LOCATION et.al. */
  29 #else
  30 /* Just include everything in sight so that the every old definition
  31    of macro is visible. */
  32 #include "gdb_string.h"
  33 #include "symtab.h"
  34 #include "frame.h"
  35 #include "inferior.h"
  36 #include "breakpoint.h"
  37 #include "gdb_wait.h"
  38 #include "gdbcore.h"
  39 #include "gdbcmd.h"
  40 #include "target.h"
  41 #include "annotate.h"
  42 #endif
  43 #include "regcache.h"
  44 #include "gdb_assert.h"
  45
  46 #include "version.h"
  47
  48 #include "floatformat.h"
  49
  50 /* Use the program counter to determine the contents and size
  51    of a breakpoint instruction.  If no target-dependent macro
  52    BREAKPOINT_FROM_PC has been defined to implement this function,
  53    assume that the breakpoint doesn't depend on the PC, and
  54    use the values of the BIG_BREAKPOINT and LITTLE_BREAKPOINT macros.
  55    Return a pointer to a string of bytes that encode a breakpoint
  56    instruction, stores the length of the string to *lenptr,
  57    and optionally adjust the pc to point to the correct memory location
  58    for inserting the breakpoint.  */
  59
  60 const unsigned char *
  61 legacy_breakpoint_from_pc (CORE_ADDR * pcptr, int *lenptr)
  62 {
  63   /* {BIG_,LITTLE_}BREAKPOINT is the sequence of bytes we insert for a
  64      breakpoint.  On some machines, breakpoints are handled by the
  65      target environment and we don't have to worry about them here.  */
  66 #ifdef BIG_BREAKPOINT
  67   if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
  68     {
  69       static unsigned char big_break_insn[] = BIG_BREAKPOINT;
  70       *lenptr = sizeof (big_break_insn);
  71       return big_break_insn;
  72     }
  73 #endif
  74 #ifdef LITTLE_BREAKPOINT
  75   if (TARGET_BYTE_ORDER != BFD_ENDIAN_BIG)
  76     {
  77       static unsigned char little_break_insn[] = LITTLE_BREAKPOINT;
  78       *lenptr = sizeof (little_break_insn);
  79       return little_break_insn;
  80     }
  81 #endif
  82 #ifdef BREAKPOINT
  83   {
  84     static unsigned char break_insn[] = BREAKPOINT;
  85     *lenptr = sizeof (break_insn);
  86     return break_insn;
  87   }
  88 #endif
  89   *lenptr = 0;
  90   return NULL;
  91 }
  92
  93 int
  94 generic_frameless_function_invocation_not (struct frame_info *fi)
  95 {
  96   return 0;
  97 }
  98
  99 int
 100 generic_return_value_on_stack_not (struct type *type)
 101 {
 102   return 0;
 103 }
 104
 105 CORE_ADDR
 106 generic_skip_trampoline_code (CORE_ADDR pc)
 107 {
 108   return 0;
 109 }
 110
 111 int
 112 generic_in_solib_call_trampoline (CORE_ADDR pc, char *name)
 113 {
 114   return 0;
 115 }
 116
 117 int
 118 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 119 {
 120   return 0;
 121 }
 122
 123 char *
 124 legacy_register_name (int i)
 125 {
 126 #ifdef REGISTER_NAMES
 127   static char *names[] = REGISTER_NAMES;
 128   if (i < 0 || i >= (sizeof (names) / sizeof (*names)))
 129     return NULL;
 130   else
 131     return names[i];
 132 #else
 133   internal_error (__FILE__, __LINE__,
 134                   "legacy_register_name: called.");
 135   return NULL;
 136 #endif
 137 }
 138
 139 #if defined (CALL_DUMMY)
 140 LONGEST legacy_call_dummy_words[] = CALL_DUMMY;
 141 #else
 142 LONGEST legacy_call_dummy_words[1];
 143 #endif
 144 int legacy_sizeof_call_dummy_words = sizeof (legacy_call_dummy_words);
 145
 146 void
 147 generic_remote_translate_xfer_address (CORE_ADDR gdb_addr, int gdb_len,
 148                                        CORE_ADDR * rem_addr, int *rem_len)
 149 {
 150   *rem_addr = gdb_addr;
 151   *rem_len = gdb_len;
 152 }
 153
 154 int
 155 generic_prologue_frameless_p (CORE_ADDR ip)
 156 {
 157   return ip == SKIP_PROLOGUE (ip);
 158 }
 159
 160 /* New/multi-arched targets should use the correct gdbarch field
 161    instead of using this global pointer. */
 162 int
 163 legacy_print_insn (bfd_vma vma, disassemble_info *info)
 164 {
 165   return (*tm_print_insn) (vma, info);
 166 }
 167
 168 /* Helper functions for INNER_THAN */
 169
 170 int
 171 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 172 {
 173   return (lhs < rhs);
 174 }
 175
 176 int
 177 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 178 {
 179   return (lhs > rhs);
 180 }
 181
 182
 183 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 184
 185 const struct floatformat *
 186 default_float_format (struct gdbarch *gdbarch)
 187 {
 188 #if GDB_MULTI_ARCH
 189   int byte_order = gdbarch_byte_order (gdbarch);
 190 #else
 191   int byte_order = TARGET_BYTE_ORDER;
 192 #endif
 193   switch (byte_order)
 194     {
 195     case BFD_ENDIAN_BIG:
 196       return &floatformat_ieee_single_big;
 197     case BFD_ENDIAN_LITTLE:
 198       return &floatformat_ieee_single_little;
 199     default:
 200       internal_error (__FILE__, __LINE__,
 201                       "default_float_format: bad byte order");
 202     }
 203 }
 204
 205
 206 const struct floatformat *
 207 default_double_format (struct gdbarch *gdbarch)
 208 {
 209 #if GDB_MULTI_ARCH
 210   int byte_order = gdbarch_byte_order (gdbarch);
 211 #else
 212   int byte_order = TARGET_BYTE_ORDER;
 213 #endif
 214   switch (byte_order)
 215     {
 216     case BFD_ENDIAN_BIG:
 217       return &floatformat_ieee_double_big;
 218     case BFD_ENDIAN_LITTLE:
 219       return &floatformat_ieee_double_little;
 220     default:
 221       internal_error (__FILE__, __LINE__,
 222                       "default_double_format: bad byte order");
 223     }
 224 }
 225
 226 void
 227 default_print_float_info (void)
 228 {
 229 #ifdef FLOAT_INFO
 230 #if GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL
 231 #error "FLOAT_INFO defined in multi-arch"
 232 #endif
 233   FLOAT_INFO;
 234 #else
 235   printf_filtered ("No floating point info available for this processor.\n");
 236 #endif
 237 }
 238
 239 /* Misc helper functions for targets. */
 240
 241 int
 242 frame_num_args_unknown (struct frame_info *fi)
 243 {
 244   return -1;
 245 }
 246
 247
 248 int
 249 generic_register_convertible_not (int num)
 250 {
 251   return 0;
 252 }
 253
 254
 255 /* Under some ABI's that specify the `struct convention' for returning
 256    structures by value, by the time we've returned from the function,
 257    the return value is sitting there in the caller's buffer, but GDB
 258    has no way to find the address of that buffer.
 259
 260    On such architectures, use this function as your
 261    extract_struct_value_address method.  When asked to a struct
 262    returned by value in this fashion, GDB will print a nice error
 263    message, instead of garbage.  */
 264 CORE_ADDR
 265 generic_cannot_extract_struct_value_address (char *dummy)
 266 {
 267   return 0;
 268 }
 269
 270 CORE_ADDR
 271 core_addr_identity (CORE_ADDR addr)
 272 {
 273   return addr;
 274 }
 275
 276 int
 277 no_op_reg_to_regnum (int reg)
 278 {
 279   return reg;
 280 }
 281
 282 /* For use by frame_args_address and frame_locals_address.  */
 283 CORE_ADDR
 284 default_frame_address (struct frame_info *fi)
 285 {
 286   return fi->frame;
 287 }
 288
 289 /* Default prepare_to_procced().  */
 290 int
 291 default_prepare_to_proceed (int select_it)
 292 {
 293   return 0;
 294 }
 295
 296 /* Generic prepare_to_proceed().  This one should be suitable for most
 297    targets that support threads. */
 298 int
 299 generic_prepare_to_proceed (int select_it)
 300 {
 301   ptid_t wait_ptid;
 302   struct target_waitstatus wait_status;
 303
 304   /* Get the last target status returned by target_wait().  */
 305   get_last_target_status (&wait_ptid, &wait_status);
 306
 307   /* Make sure we were stopped either at a breakpoint, or because
 308      of a Ctrl-C.  */
 309   if (wait_status.kind != TARGET_WAITKIND_STOPPED
 310       || (wait_status.value.sig != TARGET_SIGNAL_TRAP &&
 311           wait_status.value.sig != TARGET_SIGNAL_INT))
 312     {
 313       return 0;
 314     }
 315
 316   if (!ptid_equal (wait_ptid, minus_one_ptid)
 317       && !ptid_equal (inferior_ptid, wait_ptid))
 318     {
 319       /* Switched over from WAIT_PID.  */
 320       CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
 321
 322       if (wait_pc != read_pc ())
 323         {
 324           if (select_it)
 325             {
 326               /* Switch back to WAIT_PID thread.  */
 327               inferior_ptid = wait_ptid;
 328
 329               /* FIXME: This stuff came from switch_to_thread() in
 330                  thread.c (which should probably be a public function).  */
 331               flush_cached_frames ();
 332               registers_changed ();
 333               stop_pc = wait_pc;
 334               select_frame (get_current_frame ());
 335             }
 336           /* We return 1 to indicate that there is a breakpoint here,
 337              so we need to step over it before continuing to avoid
 338              hitting it straight away. */
 339           if (breakpoint_here_p (wait_pc))
 340             {
 341               return 1;
 342             }
 343         }
 344     }
 345   return 0;
 346
 347 }
 348
 349 void
 350 init_frame_pc_noop (int fromleaf, struct frame_info *prev)
 351 {
 352   return;
 353 }
 354
 355 void
 356 init_frame_pc_default (int fromleaf, struct frame_info *prev)
 357 {
 358   if (fromleaf)
 359     prev->pc = SAVED_PC_AFTER_CALL (prev->next);
 360   else if (prev->next != NULL)
 361     prev->pc = FRAME_SAVED_PC (prev->next);
 362   else
 363     prev->pc = read_pc ();
 364 }
 365
 366 void
 367 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 368 {
 369   return;
 370 }
 371
 372 void
 373 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 374 {
 375   return;
 376 }
 377
 378 int
 379 cannot_register_not (int regnum)
 380 {
 381   return 0;
 382 }
 383
 384 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 385    there is an FP_REGNUM and that it is the same, cooked or raw.  */
 386
 387 void
 388 legacy_virtual_frame_pointer (CORE_ADDR pc,
 389                               int *frame_regnum,
 390                               LONGEST *frame_offset)
 391 {
 392   gdb_assert (FP_REGNUM >= 0);
 393   *frame_regnum = FP_REGNUM;
 394   *frame_offset = 0;
 395 }
 396
 397 /* Assume the world is sane, every register's virtual and real size
 398    is identical.  */
 399
 400 int
 401 generic_register_size (int regnum)
 402 {
 403   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 404   return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (regnum));
 405 }
 406
 407 #if !defined (IN_SIGTRAMP)
 408 #if defined (SIGTRAMP_START)
 409 #define IN_SIGTRAMP(pc, name) \
 410        ((pc) >= SIGTRAMP_START(pc)   \
 411         && (pc) < SIGTRAMP_END(pc) \
 412         )
 413 #else
 414 #define IN_SIGTRAMP(pc, name) \
 415        (name && STREQ ("_sigtramp", name))
 416 #endif
 417 #endif
 418 \f
 419 int
 420 legacy_pc_in_sigtramp (CORE_ADDR pc, char *name)
 421 {
 422   return IN_SIGTRAMP(pc, name);
 423 }
 424
 425 int
 426 legacy_convert_register_p (int regnum)
 427 {
 428   return REGISTER_CONVERTIBLE (regnum);
 429 }
 430
 431 void
 432 legacy_register_to_value (int regnum, struct type *type,
 433                           char *from, char *to)
 434 {
 435   REGISTER_CONVERT_TO_VIRTUAL (regnum, type, from, to);
 436 }
 437
 438 void
 439 legacy_value_to_register (struct type *type, int regnum,
 440                           char *from, char *to)
 441 {
 442   REGISTER_CONVERT_TO_RAW (type, regnum, from, to);
 443 }
 444
 445 \f
 446 /* Functions to manipulate the endianness of the target.  */
 447
 448 /* ``target_byte_order'' is only used when non- multi-arch.
 449    Multi-arch targets obtain the current byte order using the
 450    TARGET_BYTE_ORDER gdbarch method.
 451
 452    The choice of initial value is entirely arbitrary.  During startup,
 453    the function initialize_current_architecture() updates this value
 454    based on default byte-order information extracted from BFD.  */
 455 int target_byte_order = BFD_ENDIAN_BIG;
 456 int target_byte_order_auto = 1;
 457
 458 static const char endian_big[] = "big";
 459 static const char endian_little[] = "little";
 460 static const char endian_auto[] = "auto";
 461 static const char *endian_enum[] =
 462 {
 463   endian_big,
 464   endian_little,
 465   endian_auto,
 466   NULL,
 467 };
 468 static const char *set_endian_string;
 469
 470 /* Called by ``show endian''.  */
 471
 472 static void
 473 show_endian (char *args, int from_tty)
 474 {
 475   if (TARGET_BYTE_ORDER_AUTO)
 476     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 477                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 478   else
 479     printf_unfiltered ("The target is assumed to be %s endian\n",
 480                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 481 }
 482
 483 static void
 484 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 485 {
 486   if (set_endian_string == endian_auto)
 487     {
 488       target_byte_order_auto = 1;
 489     }
 490   else if (set_endian_string == endian_little)
 491     {
 492       target_byte_order_auto = 0;
 493       if (GDB_MULTI_ARCH)
 494         {
 495           struct gdbarch_info info;
 496           gdbarch_info_init (&info);
 497           info.byte_order = BFD_ENDIAN_LITTLE;
 498           if (! gdbarch_update_p (info))
 499             {
 500               printf_unfiltered ("Little endian target not supported by GDB\n");
 501             }
 502         }
 503       else
 504         {
 505           target_byte_order = BFD_ENDIAN_LITTLE;
 506         }
 507     }
 508   else if (set_endian_string == endian_big)
 509     {
 510       target_byte_order_auto = 0;
 511       if (GDB_MULTI_ARCH)
 512         {
 513           struct gdbarch_info info;
 514           gdbarch_info_init (&info);
 515           info.byte_order = BFD_ENDIAN_BIG;
 516           if (! gdbarch_update_p (info))
 517             {
 518               printf_unfiltered ("Big endian target not supported by GDB\n");
 519             }
 520         }
 521       else
 522         {
 523           target_byte_order = BFD_ENDIAN_BIG;
 524         }
 525     }
 526   else
 527     internal_error (__FILE__, __LINE__,
 528                     "set_endian: bad value");
 529   show_endian (NULL, from_tty);
 530 }
 531
 532 /* Set the endianness from a BFD.  */
 533
 534 static void
 535 set_endian_from_file (bfd *abfd)
 536 {
 537   int want;
 538   if (GDB_MULTI_ARCH)
 539     internal_error (__FILE__, __LINE__,
 540                     "set_endian_from_file: not for multi-arch");
 541   if (bfd_big_endian (abfd))
 542     want = BFD_ENDIAN_BIG;
 543   else
 544     want = BFD_ENDIAN_LITTLE;
 545   if (TARGET_BYTE_ORDER_AUTO)
 546     target_byte_order = want;
 547   else if (TARGET_BYTE_ORDER != want)
 548     warning ("%s endian file does not match %s endian target.",
 549              want == BFD_ENDIAN_BIG ? "big" : "little",
 550              TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
 551 }
 552
 553
 554 /* Functions to manipulate the architecture of the target */
 555
 556 enum set_arch { set_arch_auto, set_arch_manual };
 557
 558 int target_architecture_auto = 1;
 559
 560 const char *set_architecture_string;
 561
 562 /* Old way of changing the current architecture. */
 563
 564 extern const struct bfd_arch_info bfd_default_arch_struct;
 565 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 566 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 567
 568 static int
 569 arch_ok (const struct bfd_arch_info *arch)
 570 {
 571   if (GDB_MULTI_ARCH)
 572     internal_error (__FILE__, __LINE__,
 573                     "arch_ok: not multi-arched");
 574   /* Should be performing the more basic check that the binary is
 575      compatible with GDB. */
 576   /* Check with the target that the architecture is valid. */
 577   return (target_architecture_hook == NULL
 578           || target_architecture_hook (arch));
 579 }
 580
 581 static void
 582 set_arch (const struct bfd_arch_info *arch,
 583           enum set_arch type)
 584 {
 585   if (GDB_MULTI_ARCH)
 586     internal_error (__FILE__, __LINE__,
 587                     "set_arch: not multi-arched");
 588   switch (type)
 589     {
 590     case set_arch_auto:
 591       if (!arch_ok (arch))
 592         warning ("Target may not support %s architecture",
 593                  arch->printable_name);
 594       target_architecture = arch;
 595       break;
 596     case set_arch_manual:
 597       if (!arch_ok (arch))
 598         {
 599           printf_unfiltered ("Target does not support `%s' architecture.\n",
 600                              arch->printable_name);
 601         }
 602       else
 603         {
 604           target_architecture_auto = 0;
 605           target_architecture = arch;
 606         }
 607       break;
 608     }
 609   if (gdbarch_debug)
 610     gdbarch_dump (current_gdbarch, gdb_stdlog);
 611 }
 612
 613 /* Set the architecture from arch/machine (deprecated) */
 614
 615 void
 616 set_architecture_from_arch_mach (enum bfd_architecture arch,
 617                                  unsigned long mach)
 618 {
 619   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 620   if (GDB_MULTI_ARCH)
 621     internal_error (__FILE__, __LINE__,
 622                     "set_architecture_from_arch_mach: not multi-arched");
 623   if (wanted != NULL)
 624     set_arch (wanted, set_arch_manual);
 625   else
 626     internal_error (__FILE__, __LINE__,
 627                     "gdbarch: hardwired architecture/machine not recognized");
 628 }
 629
 630 /* Set the architecture from a BFD (deprecated) */
 631
 632 static void
 633 set_architecture_from_file (bfd *abfd)
 634 {
 635   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 636   if (GDB_MULTI_ARCH)
 637     internal_error (__FILE__, __LINE__,
 638                     "set_architecture_from_file: not multi-arched");
 639   if (target_architecture_auto)
 640     {
 641       set_arch (wanted, set_arch_auto);
 642     }
 643   else if (wanted != target_architecture)
 644     {
 645       warning ("%s architecture file may be incompatible with %s target.",
 646                wanted->printable_name,
 647                target_architecture->printable_name);
 648     }
 649 }
 650
 651
 652 /* Called if the user enters ``show architecture'' without an
 653    argument. */
 654
 655 static void
 656 show_architecture (char *args, int from_tty)
 657 {
 658   const char *arch;
 659   arch = TARGET_ARCHITECTURE->printable_name;
 660   if (target_architecture_auto)
 661     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 662   else
 663     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 664 }
 665
 666
 667 /* Called if the user enters ``set architecture'' with or without an
 668    argument. */
 669
 670 static void
 671 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 672 {
 673   if (strcmp (set_architecture_string, "auto") == 0)
 674     {
 675       target_architecture_auto = 1;
 676     }
 677   else if (GDB_MULTI_ARCH)
 678     {
 679       struct gdbarch_info info;
 680       gdbarch_info_init (&info);
 681       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 682       if (info.bfd_arch_info == NULL)
 683         internal_error (__FILE__, __LINE__,
 684                         "set_architecture: bfd_scan_arch failed");
 685       if (gdbarch_update_p (info))
 686         target_architecture_auto = 0;
 687       else
 688         printf_unfiltered ("Architecture `%s' not recognized.\n",
 689                            set_architecture_string);
 690     }
 691   else
 692     {
 693       const struct bfd_arch_info *arch
 694         = bfd_scan_arch (set_architecture_string);
 695       if (arch == NULL)
 696         internal_error (__FILE__, __LINE__,
 697                         "set_architecture: bfd_scan_arch failed");
 698       set_arch (arch, set_arch_manual);
 699     }
 700   show_architecture (NULL, from_tty);
 701 }
 702
 703 /* Set the dynamic target-system-dependent parameters (architecture,
 704    byte-order) using information found in the BFD */
 705
 706 void
 707 set_gdbarch_from_file (bfd *abfd)
 708 {
 709   if (GDB_MULTI_ARCH)
 710     {
 711       struct gdbarch_info info;
 712       gdbarch_info_init (&info);
 713       info.abfd = abfd;
 714       if (! gdbarch_update_p (info))
 715         error ("Architecture of file not recognized.\n");
 716     }
 717   else
 718     {
 719       set_architecture_from_file (abfd);
 720       set_endian_from_file (abfd);
 721     }
 722 }
 723
 724 /* Initialize the current architecture.  Update the ``set
 725    architecture'' command so that it specifies a list of valid
 726    architectures.  */
 727
 728 #ifdef DEFAULT_BFD_ARCH
 729 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 730 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 731 #else
 732 static const bfd_arch_info_type *default_bfd_arch;
 733 #endif
 734
 735 #ifdef DEFAULT_BFD_VEC
 736 extern const bfd_target DEFAULT_BFD_VEC;
 737 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 738 #else
 739 static const bfd_target *default_bfd_vec;
 740 #endif
 741
 742 void
 743 initialize_current_architecture (void)
 744 {
 745   const char **arches = gdbarch_printable_names ();
 746
 747   /* determine a default architecture and byte order. */
 748   struct gdbarch_info info;
 749   gdbarch_info_init (&info);
 750
 751   /* Find a default architecture. */
 752   if (info.bfd_arch_info == NULL
 753       && default_bfd_arch != NULL)
 754     info.bfd_arch_info = default_bfd_arch;
 755   if (info.bfd_arch_info == NULL)
 756     {
 757       /* Choose the architecture by taking the first one
 758          alphabetically. */
 759       const char *chosen = arches[0];
 760       const char **arch;
 761       for (arch = arches; *arch != NULL; arch++)
 762         {
 763           if (strcmp (*arch, chosen) < 0)
 764             chosen = *arch;
 765         }
 766       if (chosen == NULL)
 767         internal_error (__FILE__, __LINE__,
 768                         "initialize_current_architecture: No arch");
 769       info.bfd_arch_info = bfd_scan_arch (chosen);
 770       if (info.bfd_arch_info == NULL)
 771         internal_error (__FILE__, __LINE__,
 772                         "initialize_current_architecture: Arch not found");
 773     }
 774
 775   /* Take several guesses at a byte order.  */
 776   if (info.byte_order == BFD_ENDIAN_UNKNOWN
 777       && default_bfd_vec != NULL)
 778     {
 779       /* Extract BFD's default vector's byte order. */
 780       switch (default_bfd_vec->byteorder)
 781         {
 782         case BFD_ENDIAN_BIG:
 783           info.byte_order = BFD_ENDIAN_BIG;
 784           break;
 785         case BFD_ENDIAN_LITTLE:
 786           info.byte_order = BFD_ENDIAN_LITTLE;
 787           break;
 788         default:
 789           break;
 790         }
 791     }
 792   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 793     {
 794       /* look for ``*el-*'' in the target name. */
 795       const char *chp;
 796       chp = strchr (target_name, '-');
 797       if (chp != NULL
 798           && chp - 2 >= target_name
 799           && strncmp (chp - 2, "el", 2) == 0)
 800         info.byte_order = BFD_ENDIAN_LITTLE;
 801     }
 802   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 803     {
 804       /* Wire it to big-endian!!! */
 805       info.byte_order = BFD_ENDIAN_BIG;
 806     }
 807
 808   if (GDB_MULTI_ARCH)
 809     {
 810       if (! gdbarch_update_p (info))
 811         {
 812           internal_error (__FILE__, __LINE__,
 813                           "initialize_current_architecture: Selection of initial architecture failed");
 814         }
 815     }
 816   else
 817     {
 818       /* If the multi-arch logic comes up with a byte-order (from BFD)
 819          use it for the non-multi-arch case.  */
 820       if (info.byte_order != BFD_ENDIAN_UNKNOWN)
 821         target_byte_order = info.byte_order;
 822       initialize_non_multiarch ();
 823     }
 824
 825   /* Create the ``set architecture'' command appending ``auto'' to the
 826      list of architectures. */
 827   {
 828     struct cmd_list_element *c;
 829     /* Append ``auto''. */
 830     int nr;
 831     for (nr = 0; arches[nr] != NULL; nr++);
 832     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 833     arches[nr + 0] = "auto";
 834     arches[nr + 1] = NULL;
 835     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 836        of ``const char *''.  We just happen to know that the casts are
 837        safe. */
 838     c = add_set_enum_cmd ("architecture", class_support,
 839                           arches, &set_architecture_string,
 840                           "Set architecture of target.",
 841                           &setlist);
 842     set_cmd_sfunc (c, set_architecture);
 843     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 844     /* Don't use set_from_show - need to print both auto/manual and
 845        current setting. */
 846     add_cmd ("architecture", class_support, show_architecture,
 847              "Show the current target architecture", &showlist);
 848   }
 849 }
 850
 851
 852 /* Initialize a gdbarch info to values that will be automatically
 853    overridden.  Note: Originally, this ``struct info'' was initialized
 854    using memset(0).  Unfortunatly, that ran into problems, namely
 855    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 856    can explicitly set each field to a well defined value is used.  */
 857
 858 void
 859 gdbarch_info_init (struct gdbarch_info *info)
 860 {
 861   memset (info, 0, sizeof (struct gdbarch_info));
 862   info->byte_order = BFD_ENDIAN_UNKNOWN;
 863 }
 864
 865 /* */
 866
 867 extern initialize_file_ftype _initialize_gdbarch_utils;
 868
 869 void
 870 _initialize_gdbarch_utils (void)
 871 {
 872   struct cmd_list_element *c;
 873   c = add_set_enum_cmd ("endian", class_support,
 874                         endian_enum, &set_endian_string,
 875                         "Set endianness of target.",
 876                         &setlist);
 877   set_cmd_sfunc (c, set_endian);
 878   /* Don't use set_from_show - need to print both auto/manual and
 879      current setting. */
 880   add_cmd ("endian", class_support, show_endian,
 881            "Show the current byte-order", &showlist);
 882 }