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 int
 271 default_register_sim_regno (int num)
 272 {
 273   return num;
 274 }
 275
 276
 277 CORE_ADDR
 278 core_addr_identity (CORE_ADDR addr)
 279 {
 280   return addr;
 281 }
 282
 283 int
 284 no_op_reg_to_regnum (int reg)
 285 {
 286   return reg;
 287 }
 288
 289 /* For use by frame_args_address and frame_locals_address.  */
 290 CORE_ADDR
 291 default_frame_address (struct frame_info *fi)
 292 {
 293   return fi->frame;
 294 }
 295
 296 /* Default prepare_to_procced().  */
 297 int
 298 default_prepare_to_proceed (int select_it)
 299 {
 300   return 0;
 301 }
 302
 303 /* Generic prepare_to_proceed().  This one should be suitable for most
 304    targets that support threads. */
 305 int
 306 generic_prepare_to_proceed (int select_it)
 307 {
 308   ptid_t wait_ptid;
 309   struct target_waitstatus wait_status;
 310
 311   /* Get the last target status returned by target_wait().  */
 312   get_last_target_status (&wait_ptid, &wait_status);
 313
 314   /* Make sure we were stopped either at a breakpoint, or because
 315      of a Ctrl-C.  */
 316   if (wait_status.kind != TARGET_WAITKIND_STOPPED
 317       || (wait_status.value.sig != TARGET_SIGNAL_TRAP &&
 318           wait_status.value.sig != TARGET_SIGNAL_INT))
 319     {
 320       return 0;
 321     }
 322
 323   if (!ptid_equal (wait_ptid, minus_one_ptid)
 324       && !ptid_equal (inferior_ptid, wait_ptid))
 325     {
 326       /* Switched over from WAIT_PID.  */
 327       CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
 328
 329       if (wait_pc != read_pc ())
 330         {
 331           if (select_it)
 332             {
 333               /* Switch back to WAIT_PID thread.  */
 334               inferior_ptid = wait_ptid;
 335
 336               /* FIXME: This stuff came from switch_to_thread() in
 337                  thread.c (which should probably be a public function).  */
 338               flush_cached_frames ();
 339               registers_changed ();
 340               stop_pc = wait_pc;
 341               select_frame (get_current_frame ());
 342             }
 343           /* We return 1 to indicate that there is a breakpoint here,
 344              so we need to step over it before continuing to avoid
 345              hitting it straight away. */
 346           if (breakpoint_here_p (wait_pc))
 347             {
 348               return 1;
 349             }
 350         }
 351     }
 352   return 0;
 353
 354 }
 355
 356 void
 357 init_frame_pc_noop (int fromleaf, struct frame_info *prev)
 358 {
 359   return;
 360 }
 361
 362 void
 363 init_frame_pc_default (int fromleaf, struct frame_info *prev)
 364 {
 365   if (fromleaf)
 366     prev->pc = SAVED_PC_AFTER_CALL (prev->next);
 367   else if (prev->next != NULL)
 368     prev->pc = FRAME_SAVED_PC (prev->next);
 369   else
 370     prev->pc = read_pc ();
 371 }
 372
 373 void
 374 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 375 {
 376   return;
 377 }
 378
 379 void
 380 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 381 {
 382   return;
 383 }
 384
 385 int
 386 cannot_register_not (int regnum)
 387 {
 388   return 0;
 389 }
 390
 391 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 392    there is an FP_REGNUM and that it is the same, cooked or raw.  */
 393
 394 void
 395 legacy_virtual_frame_pointer (CORE_ADDR pc,
 396                               int *frame_regnum,
 397                               LONGEST *frame_offset)
 398 {
 399   gdb_assert (FP_REGNUM >= 0);
 400   *frame_regnum = FP_REGNUM;
 401   *frame_offset = 0;
 402 }
 403
 404 /* Assume the world is flat.  Every register is large enough to fit a
 405    target integer.  */
 406
 407 int
 408 generic_register_raw_size (int regnum)
 409 {
 410   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 411   return TARGET_INT_BIT / HOST_CHAR_BIT;
 412 }
 413
 414 /* Assume the virtual size corresponds to the virtual type.  */
 415
 416 int
 417 generic_register_virtual_size (int regnum)
 418 {
 419   return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (regnum));
 420 }
 421
 422 #if !defined (IN_SIGTRAMP)
 423 #if defined (SIGTRAMP_START)
 424 #define IN_SIGTRAMP(pc, name) \
 425        ((pc) >= SIGTRAMP_START(pc)   \
 426         && (pc) < SIGTRAMP_END(pc) \
 427         )
 428 #else
 429 #define IN_SIGTRAMP(pc, name) \
 430        (name && STREQ ("_sigtramp", name))
 431 #endif
 432 #endif
 433 \f
 434 int
 435 legacy_pc_in_sigtramp (CORE_ADDR pc, char *name)
 436 {
 437   return IN_SIGTRAMP(pc, name);
 438 }
 439
 440 \f
 441 /* Functions to manipulate the endianness of the target.  */
 442
 443 /* ``target_byte_order'' is only used when non- multi-arch.
 444    Multi-arch targets obtain the current byte order using the
 445    TARGET_BYTE_ORDER gdbarch method.
 446
 447    The choice of initial value is entirely arbitrary.  During startup,
 448    the function initialize_current_architecture() updates this value
 449    based on default byte-order information extracted from BFD.  */
 450 int target_byte_order = BFD_ENDIAN_BIG;
 451 int target_byte_order_auto = 1;
 452
 453 static const char endian_big[] = "big";
 454 static const char endian_little[] = "little";
 455 static const char endian_auto[] = "auto";
 456 static const char *endian_enum[] =
 457 {
 458   endian_big,
 459   endian_little,
 460   endian_auto,
 461   NULL,
 462 };
 463 static const char *set_endian_string;
 464
 465 /* Called by ``show endian''.  */
 466
 467 static void
 468 show_endian (char *args, int from_tty)
 469 {
 470   if (TARGET_BYTE_ORDER_AUTO)
 471     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 472                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 473   else
 474     printf_unfiltered ("The target is assumed to be %s endian\n",
 475                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 476 }
 477
 478 static void
 479 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 480 {
 481   if (set_endian_string == endian_auto)
 482     {
 483       target_byte_order_auto = 1;
 484     }
 485   else if (set_endian_string == endian_little)
 486     {
 487       target_byte_order_auto = 0;
 488       if (GDB_MULTI_ARCH)
 489         {
 490           struct gdbarch_info info;
 491           gdbarch_info_init (&info);
 492           info.byte_order = BFD_ENDIAN_LITTLE;
 493           if (! gdbarch_update_p (info))
 494             {
 495               printf_unfiltered ("Little endian target not supported by GDB\n");
 496             }
 497         }
 498       else
 499         {
 500           target_byte_order = BFD_ENDIAN_LITTLE;
 501         }
 502     }
 503   else if (set_endian_string == endian_big)
 504     {
 505       target_byte_order_auto = 0;
 506       if (GDB_MULTI_ARCH)
 507         {
 508           struct gdbarch_info info;
 509           gdbarch_info_init (&info);
 510           info.byte_order = BFD_ENDIAN_BIG;
 511           if (! gdbarch_update_p (info))
 512             {
 513               printf_unfiltered ("Big endian target not supported by GDB\n");
 514             }
 515         }
 516       else
 517         {
 518           target_byte_order = BFD_ENDIAN_BIG;
 519         }
 520     }
 521   else
 522     internal_error (__FILE__, __LINE__,
 523                     "set_endian: bad value");
 524   show_endian (NULL, from_tty);
 525 }
 526
 527 /* Set the endianness from a BFD.  */
 528
 529 static void
 530 set_endian_from_file (bfd *abfd)
 531 {
 532   int want;
 533   if (GDB_MULTI_ARCH)
 534     internal_error (__FILE__, __LINE__,
 535                     "set_endian_from_file: not for multi-arch");
 536   if (bfd_big_endian (abfd))
 537     want = BFD_ENDIAN_BIG;
 538   else
 539     want = BFD_ENDIAN_LITTLE;
 540   if (TARGET_BYTE_ORDER_AUTO)
 541     target_byte_order = want;
 542   else if (TARGET_BYTE_ORDER != want)
 543     warning ("%s endian file does not match %s endian target.",
 544              want == BFD_ENDIAN_BIG ? "big" : "little",
 545              TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
 546 }
 547
 548
 549 /* Functions to manipulate the architecture of the target */
 550
 551 enum set_arch { set_arch_auto, set_arch_manual };
 552
 553 int target_architecture_auto = 1;
 554
 555 const char *set_architecture_string;
 556
 557 /* Old way of changing the current architecture. */
 558
 559 extern const struct bfd_arch_info bfd_default_arch_struct;
 560 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 561 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 562
 563 static int
 564 arch_ok (const struct bfd_arch_info *arch)
 565 {
 566   if (GDB_MULTI_ARCH)
 567     internal_error (__FILE__, __LINE__,
 568                     "arch_ok: not multi-arched");
 569   /* Should be performing the more basic check that the binary is
 570      compatible with GDB. */
 571   /* Check with the target that the architecture is valid. */
 572   return (target_architecture_hook == NULL
 573           || target_architecture_hook (arch));
 574 }
 575
 576 static void
 577 set_arch (const struct bfd_arch_info *arch,
 578           enum set_arch type)
 579 {
 580   if (GDB_MULTI_ARCH)
 581     internal_error (__FILE__, __LINE__,
 582                     "set_arch: not multi-arched");
 583   switch (type)
 584     {
 585     case set_arch_auto:
 586       if (!arch_ok (arch))
 587         warning ("Target may not support %s architecture",
 588                  arch->printable_name);
 589       target_architecture = arch;
 590       break;
 591     case set_arch_manual:
 592       if (!arch_ok (arch))
 593         {
 594           printf_unfiltered ("Target does not support `%s' architecture.\n",
 595                              arch->printable_name);
 596         }
 597       else
 598         {
 599           target_architecture_auto = 0;
 600           target_architecture = arch;
 601         }
 602       break;
 603     }
 604   if (gdbarch_debug)
 605     gdbarch_dump (current_gdbarch, gdb_stdlog);
 606 }
 607
 608 /* Set the architecture from arch/machine (deprecated) */
 609
 610 void
 611 set_architecture_from_arch_mach (enum bfd_architecture arch,
 612                                  unsigned long mach)
 613 {
 614   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 615   if (GDB_MULTI_ARCH)
 616     internal_error (__FILE__, __LINE__,
 617                     "set_architecture_from_arch_mach: not multi-arched");
 618   if (wanted != NULL)
 619     set_arch (wanted, set_arch_manual);
 620   else
 621     internal_error (__FILE__, __LINE__,
 622                     "gdbarch: hardwired architecture/machine not recognized");
 623 }
 624
 625 /* Set the architecture from a BFD (deprecated) */
 626
 627 static void
 628 set_architecture_from_file (bfd *abfd)
 629 {
 630   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 631   if (GDB_MULTI_ARCH)
 632     internal_error (__FILE__, __LINE__,
 633                     "set_architecture_from_file: not multi-arched");
 634   if (target_architecture_auto)
 635     {
 636       set_arch (wanted, set_arch_auto);
 637     }
 638   else if (wanted != target_architecture)
 639     {
 640       warning ("%s architecture file may be incompatible with %s target.",
 641                wanted->printable_name,
 642                target_architecture->printable_name);
 643     }
 644 }
 645
 646
 647 /* Called if the user enters ``show architecture'' without an
 648    argument. */
 649
 650 static void
 651 show_architecture (char *args, int from_tty)
 652 {
 653   const char *arch;
 654   arch = TARGET_ARCHITECTURE->printable_name;
 655   if (target_architecture_auto)
 656     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 657   else
 658     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 659 }
 660
 661
 662 /* Called if the user enters ``set architecture'' with or without an
 663    argument. */
 664
 665 static void
 666 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 667 {
 668   if (strcmp (set_architecture_string, "auto") == 0)
 669     {
 670       target_architecture_auto = 1;
 671     }
 672   else if (GDB_MULTI_ARCH)
 673     {
 674       struct gdbarch_info info;
 675       gdbarch_info_init (&info);
 676       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 677       if (info.bfd_arch_info == NULL)
 678         internal_error (__FILE__, __LINE__,
 679                         "set_architecture: bfd_scan_arch failed");
 680       if (gdbarch_update_p (info))
 681         target_architecture_auto = 0;
 682       else
 683         printf_unfiltered ("Architecture `%s' not recognized.\n",
 684                            set_architecture_string);
 685     }
 686   else
 687     {
 688       const struct bfd_arch_info *arch
 689         = bfd_scan_arch (set_architecture_string);
 690       if (arch == NULL)
 691         internal_error (__FILE__, __LINE__,
 692                         "set_architecture: bfd_scan_arch failed");
 693       set_arch (arch, set_arch_manual);
 694     }
 695   show_architecture (NULL, from_tty);
 696 }
 697
 698 /* Set the dynamic target-system-dependent parameters (architecture,
 699    byte-order) using information found in the BFD */
 700
 701 void
 702 set_gdbarch_from_file (bfd *abfd)
 703 {
 704   if (GDB_MULTI_ARCH)
 705     {
 706       struct gdbarch_info info;
 707       gdbarch_info_init (&info);
 708       info.abfd = abfd;
 709       if (! gdbarch_update_p (info))
 710         error ("Architecture of file not recognized.\n");
 711     }
 712   else
 713     {
 714       set_architecture_from_file (abfd);
 715       set_endian_from_file (abfd);
 716     }
 717 }
 718
 719 /* Initialize the current architecture.  Update the ``set
 720    architecture'' command so that it specifies a list of valid
 721    architectures.  */
 722
 723 #ifdef DEFAULT_BFD_ARCH
 724 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 725 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 726 #else
 727 static const bfd_arch_info_type *default_bfd_arch;
 728 #endif
 729
 730 #ifdef DEFAULT_BFD_VEC
 731 extern const bfd_target DEFAULT_BFD_VEC;
 732 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 733 #else
 734 static const bfd_target *default_bfd_vec;
 735 #endif
 736
 737 void
 738 initialize_current_architecture (void)
 739 {
 740   const char **arches = gdbarch_printable_names ();
 741
 742   /* determine a default architecture and byte order. */
 743   struct gdbarch_info info;
 744   gdbarch_info_init (&info);
 745
 746   /* Find a default architecture. */
 747   if (info.bfd_arch_info == NULL
 748       && default_bfd_arch != NULL)
 749     info.bfd_arch_info = default_bfd_arch;
 750   if (info.bfd_arch_info == NULL)
 751     {
 752       /* Choose the architecture by taking the first one
 753          alphabetically. */
 754       const char *chosen = arches[0];
 755       const char **arch;
 756       for (arch = arches; *arch != NULL; arch++)
 757         {
 758           if (strcmp (*arch, chosen) < 0)
 759             chosen = *arch;
 760         }
 761       if (chosen == NULL)
 762         internal_error (__FILE__, __LINE__,
 763                         "initialize_current_architecture: No arch");
 764       info.bfd_arch_info = bfd_scan_arch (chosen);
 765       if (info.bfd_arch_info == NULL)
 766         internal_error (__FILE__, __LINE__,
 767                         "initialize_current_architecture: Arch not found");
 768     }
 769
 770   /* Take several guesses at a byte order.  */
 771   if (info.byte_order == BFD_ENDIAN_UNKNOWN
 772       && default_bfd_vec != NULL)
 773     {
 774       /* Extract BFD's default vector's byte order. */
 775       switch (default_bfd_vec->byteorder)
 776         {
 777         case BFD_ENDIAN_BIG:
 778           info.byte_order = BFD_ENDIAN_BIG;
 779           break;
 780         case BFD_ENDIAN_LITTLE:
 781           info.byte_order = BFD_ENDIAN_LITTLE;
 782           break;
 783         default:
 784           break;
 785         }
 786     }
 787   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 788     {
 789       /* look for ``*el-*'' in the target name. */
 790       const char *chp;
 791       chp = strchr (target_name, '-');
 792       if (chp != NULL
 793           && chp - 2 >= target_name
 794           && strncmp (chp - 2, "el", 2) == 0)
 795         info.byte_order = BFD_ENDIAN_LITTLE;
 796     }
 797   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 798     {
 799       /* Wire it to big-endian!!! */
 800       info.byte_order = BFD_ENDIAN_BIG;
 801     }
 802
 803   if (GDB_MULTI_ARCH)
 804     {
 805       if (! gdbarch_update_p (info))
 806         {
 807           internal_error (__FILE__, __LINE__,
 808                           "initialize_current_architecture: Selection of initial architecture failed");
 809         }
 810     }
 811   else
 812     {
 813       /* If the multi-arch logic comes up with a byte-order (from BFD)
 814          use it for the non-multi-arch case.  */
 815       if (info.byte_order != BFD_ENDIAN_UNKNOWN)
 816         target_byte_order = info.byte_order;
 817       initialize_non_multiarch ();
 818     }
 819
 820   /* Create the ``set architecture'' command appending ``auto'' to the
 821      list of architectures. */
 822   {
 823     struct cmd_list_element *c;
 824     /* Append ``auto''. */
 825     int nr;
 826     for (nr = 0; arches[nr] != NULL; nr++);
 827     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 828     arches[nr + 0] = "auto";
 829     arches[nr + 1] = NULL;
 830     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 831        of ``const char *''.  We just happen to know that the casts are
 832        safe. */
 833     c = add_set_enum_cmd ("architecture", class_support,
 834                           arches, &set_architecture_string,
 835                           "Set architecture of target.",
 836                           &setlist);
 837     set_cmd_sfunc (c, set_architecture);
 838     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 839     /* Don't use set_from_show - need to print both auto/manual and
 840        current setting. */
 841     add_cmd ("architecture", class_support, show_architecture,
 842              "Show the current target architecture", &showlist);
 843   }
 844 }
 845
 846
 847 /* Initialize a gdbarch info to values that will be automatically
 848    overridden.  Note: Originally, this ``struct info'' was initialized
 849    using memset(0).  Unfortunatly, that ran into problems, namely
 850    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 851    can explicitly set each field to a well defined value is used.  */
 852
 853 void
 854 gdbarch_info_init (struct gdbarch_info *info)
 855 {
 856   memset (info, 0, sizeof (struct gdbarch_info));
 857   info->byte_order = BFD_ENDIAN_UNKNOWN;
 858 }
 859
 860 /* */
 861
 862 extern initialize_file_ftype _initialize_gdbarch_utils;
 863
 864 void
 865 _initialize_gdbarch_utils (void)
 866 {
 867   struct cmd_list_element *c;
 868   c = add_set_enum_cmd ("endian", class_support,
 869                         endian_enum, &set_endian_string,
 870                         "Set endianness of target.",
 871                         &setlist);
 872   set_cmd_sfunc (c, set_endian);
 873   /* Don't use set_from_show - need to print both auto/manual and
 874      current setting. */
 875   add_cmd ("endian", class_support, show_endian,
 876            "Show the current byte-order", &showlist);
 877 }