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 (), 0);
 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 \f
 423 /* Functions to manipulate the endianness of the target.  */
 424
 425 /* ``target_byte_order'' is only used when non- multi-arch.
 426    Multi-arch targets obtain the current byte order using the
 427    TARGET_BYTE_ORDER gdbarch method.
 428
 429    The choice of initial value is entirely arbitrary.  During startup,
 430    the function initialize_current_architecture() updates this value
 431    based on default byte-order information extracted from BFD.  */
 432 int target_byte_order = BFD_ENDIAN_BIG;
 433 int target_byte_order_auto = 1;
 434
 435 static const char endian_big[] = "big";
 436 static const char endian_little[] = "little";
 437 static const char endian_auto[] = "auto";
 438 static const char *endian_enum[] =
 439 {
 440   endian_big,
 441   endian_little,
 442   endian_auto,
 443   NULL,
 444 };
 445 static const char *set_endian_string;
 446
 447 /* Called by ``show endian''.  */
 448
 449 static void
 450 show_endian (char *args, int from_tty)
 451 {
 452   if (TARGET_BYTE_ORDER_AUTO)
 453     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 454                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 455   else
 456     printf_unfiltered ("The target is assumed to be %s endian\n",
 457                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 458 }
 459
 460 static void
 461 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 462 {
 463   if (set_endian_string == endian_auto)
 464     {
 465       target_byte_order_auto = 1;
 466     }
 467   else if (set_endian_string == endian_little)
 468     {
 469       target_byte_order_auto = 0;
 470       if (GDB_MULTI_ARCH)
 471         {
 472           struct gdbarch_info info;
 473           gdbarch_info_init (&info);
 474           info.byte_order = BFD_ENDIAN_LITTLE;
 475           if (! gdbarch_update_p (info))
 476             {
 477               printf_unfiltered ("Little endian target not supported by GDB\n");
 478             }
 479         }
 480       else
 481         {
 482           target_byte_order = BFD_ENDIAN_LITTLE;
 483         }
 484     }
 485   else if (set_endian_string == endian_big)
 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_BIG;
 493           if (! gdbarch_update_p (info))
 494             {
 495               printf_unfiltered ("Big endian target not supported by GDB\n");
 496             }
 497         }
 498       else
 499         {
 500           target_byte_order = BFD_ENDIAN_BIG;
 501         }
 502     }
 503   else
 504     internal_error (__FILE__, __LINE__,
 505                     "set_endian: bad value");
 506   show_endian (NULL, from_tty);
 507 }
 508
 509 /* Set the endianness from a BFD.  */
 510
 511 static void
 512 set_endian_from_file (bfd *abfd)
 513 {
 514   int want;
 515   if (GDB_MULTI_ARCH)
 516     internal_error (__FILE__, __LINE__,
 517                     "set_endian_from_file: not for multi-arch");
 518   if (bfd_big_endian (abfd))
 519     want = BFD_ENDIAN_BIG;
 520   else
 521     want = BFD_ENDIAN_LITTLE;
 522   if (TARGET_BYTE_ORDER_AUTO)
 523     target_byte_order = want;
 524   else if (TARGET_BYTE_ORDER != want)
 525     warning ("%s endian file does not match %s endian target.",
 526              want == BFD_ENDIAN_BIG ? "big" : "little",
 527              TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
 528 }
 529
 530
 531 /* Functions to manipulate the architecture of the target */
 532
 533 enum set_arch { set_arch_auto, set_arch_manual };
 534
 535 int target_architecture_auto = 1;
 536
 537 const char *set_architecture_string;
 538
 539 /* Old way of changing the current architecture. */
 540
 541 extern const struct bfd_arch_info bfd_default_arch_struct;
 542 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 543 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 544
 545 static int
 546 arch_ok (const struct bfd_arch_info *arch)
 547 {
 548   if (GDB_MULTI_ARCH)
 549     internal_error (__FILE__, __LINE__,
 550                     "arch_ok: not multi-arched");
 551   /* Should be performing the more basic check that the binary is
 552      compatible with GDB. */
 553   /* Check with the target that the architecture is valid. */
 554   return (target_architecture_hook == NULL
 555           || target_architecture_hook (arch));
 556 }
 557
 558 static void
 559 set_arch (const struct bfd_arch_info *arch,
 560           enum set_arch type)
 561 {
 562   if (GDB_MULTI_ARCH)
 563     internal_error (__FILE__, __LINE__,
 564                     "set_arch: not multi-arched");
 565   switch (type)
 566     {
 567     case set_arch_auto:
 568       if (!arch_ok (arch))
 569         warning ("Target may not support %s architecture",
 570                  arch->printable_name);
 571       target_architecture = arch;
 572       break;
 573     case set_arch_manual:
 574       if (!arch_ok (arch))
 575         {
 576           printf_unfiltered ("Target does not support `%s' architecture.\n",
 577                              arch->printable_name);
 578         }
 579       else
 580         {
 581           target_architecture_auto = 0;
 582           target_architecture = arch;
 583         }
 584       break;
 585     }
 586   if (gdbarch_debug)
 587     gdbarch_dump (current_gdbarch, gdb_stdlog);
 588 }
 589
 590 /* Set the architecture from arch/machine (deprecated) */
 591
 592 void
 593 set_architecture_from_arch_mach (enum bfd_architecture arch,
 594                                  unsigned long mach)
 595 {
 596   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 597   if (GDB_MULTI_ARCH)
 598     internal_error (__FILE__, __LINE__,
 599                     "set_architecture_from_arch_mach: not multi-arched");
 600   if (wanted != NULL)
 601     set_arch (wanted, set_arch_manual);
 602   else
 603     internal_error (__FILE__, __LINE__,
 604                     "gdbarch: hardwired architecture/machine not recognized");
 605 }
 606
 607 /* Set the architecture from a BFD (deprecated) */
 608
 609 static void
 610 set_architecture_from_file (bfd *abfd)
 611 {
 612   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 613   if (GDB_MULTI_ARCH)
 614     internal_error (__FILE__, __LINE__,
 615                     "set_architecture_from_file: not multi-arched");
 616   if (target_architecture_auto)
 617     {
 618       set_arch (wanted, set_arch_auto);
 619     }
 620   else if (wanted != target_architecture)
 621     {
 622       warning ("%s architecture file may be incompatible with %s target.",
 623                wanted->printable_name,
 624                target_architecture->printable_name);
 625     }
 626 }
 627
 628
 629 /* Called if the user enters ``show architecture'' without an
 630    argument. */
 631
 632 static void
 633 show_architecture (char *args, int from_tty)
 634 {
 635   const char *arch;
 636   arch = TARGET_ARCHITECTURE->printable_name;
 637   if (target_architecture_auto)
 638     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 639   else
 640     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 641 }
 642
 643
 644 /* Called if the user enters ``set architecture'' with or without an
 645    argument. */
 646
 647 static void
 648 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 649 {
 650   if (strcmp (set_architecture_string, "auto") == 0)
 651     {
 652       target_architecture_auto = 1;
 653     }
 654   else if (GDB_MULTI_ARCH)
 655     {
 656       struct gdbarch_info info;
 657       gdbarch_info_init (&info);
 658       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 659       if (info.bfd_arch_info == NULL)
 660         internal_error (__FILE__, __LINE__,
 661                         "set_architecture: bfd_scan_arch failed");
 662       if (gdbarch_update_p (info))
 663         target_architecture_auto = 0;
 664       else
 665         printf_unfiltered ("Architecture `%s' not recognized.\n",
 666                            set_architecture_string);
 667     }
 668   else
 669     {
 670       const struct bfd_arch_info *arch
 671         = bfd_scan_arch (set_architecture_string);
 672       if (arch == NULL)
 673         internal_error (__FILE__, __LINE__,
 674                         "set_architecture: bfd_scan_arch failed");
 675       set_arch (arch, set_arch_manual);
 676     }
 677   show_architecture (NULL, from_tty);
 678 }
 679
 680 /* Set the dynamic target-system-dependent parameters (architecture,
 681    byte-order) using information found in the BFD */
 682
 683 void
 684 set_gdbarch_from_file (bfd *abfd)
 685 {
 686   if (GDB_MULTI_ARCH)
 687     {
 688       struct gdbarch_info info;
 689       gdbarch_info_init (&info);
 690       info.abfd = abfd;
 691       if (! gdbarch_update_p (info))
 692         error ("Architecture of file not recognized.\n");
 693     }
 694   else
 695     {
 696       set_architecture_from_file (abfd);
 697       set_endian_from_file (abfd);
 698     }
 699 }
 700
 701 /* Initialize the current architecture.  Update the ``set
 702    architecture'' command so that it specifies a list of valid
 703    architectures.  */
 704
 705 #ifdef DEFAULT_BFD_ARCH
 706 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 707 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 708 #else
 709 static const bfd_arch_info_type *default_bfd_arch;
 710 #endif
 711
 712 #ifdef DEFAULT_BFD_VEC
 713 extern const bfd_target DEFAULT_BFD_VEC;
 714 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 715 #else
 716 static const bfd_target *default_bfd_vec;
 717 #endif
 718
 719 void
 720 initialize_current_architecture (void)
 721 {
 722   const char **arches = gdbarch_printable_names ();
 723
 724   /* determine a default architecture and byte order. */
 725   struct gdbarch_info info;
 726   gdbarch_info_init (&info);
 727
 728   /* Find a default architecture. */
 729   if (info.bfd_arch_info == NULL
 730       && default_bfd_arch != NULL)
 731     info.bfd_arch_info = default_bfd_arch;
 732   if (info.bfd_arch_info == NULL)
 733     {
 734       /* Choose the architecture by taking the first one
 735          alphabetically. */
 736       const char *chosen = arches[0];
 737       const char **arch;
 738       for (arch = arches; *arch != NULL; arch++)
 739         {
 740           if (strcmp (*arch, chosen) < 0)
 741             chosen = *arch;
 742         }
 743       if (chosen == NULL)
 744         internal_error (__FILE__, __LINE__,
 745                         "initialize_current_architecture: No arch");
 746       info.bfd_arch_info = bfd_scan_arch (chosen);
 747       if (info.bfd_arch_info == NULL)
 748         internal_error (__FILE__, __LINE__,
 749                         "initialize_current_architecture: Arch not found");
 750     }
 751
 752   /* Take several guesses at a byte order.  */
 753   if (info.byte_order == BFD_ENDIAN_UNKNOWN
 754       && default_bfd_vec != NULL)
 755     {
 756       /* Extract BFD's default vector's byte order. */
 757       switch (default_bfd_vec->byteorder)
 758         {
 759         case BFD_ENDIAN_BIG:
 760           info.byte_order = BFD_ENDIAN_BIG;
 761           break;
 762         case BFD_ENDIAN_LITTLE:
 763           info.byte_order = BFD_ENDIAN_LITTLE;
 764           break;
 765         default:
 766           break;
 767         }
 768     }
 769   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 770     {
 771       /* look for ``*el-*'' in the target name. */
 772       const char *chp;
 773       chp = strchr (target_name, '-');
 774       if (chp != NULL
 775           && chp - 2 >= target_name
 776           && strncmp (chp - 2, "el", 2) == 0)
 777         info.byte_order = BFD_ENDIAN_LITTLE;
 778     }
 779   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 780     {
 781       /* Wire it to big-endian!!! */
 782       info.byte_order = BFD_ENDIAN_BIG;
 783     }
 784
 785   if (GDB_MULTI_ARCH)
 786     {
 787       if (! gdbarch_update_p (info))
 788         {
 789           internal_error (__FILE__, __LINE__,
 790                           "initialize_current_architecture: Selection of initial architecture failed");
 791         }
 792     }
 793   else
 794     {
 795       /* If the multi-arch logic comes up with a byte-order (from BFD)
 796          use it for the non-multi-arch case.  */
 797       if (info.byte_order != BFD_ENDIAN_UNKNOWN)
 798         target_byte_order = info.byte_order;
 799       initialize_non_multiarch ();
 800     }
 801
 802   /* Create the ``set architecture'' command appending ``auto'' to the
 803      list of architectures. */
 804   {
 805     struct cmd_list_element *c;
 806     /* Append ``auto''. */
 807     int nr;
 808     for (nr = 0; arches[nr] != NULL; nr++);
 809     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 810     arches[nr + 0] = "auto";
 811     arches[nr + 1] = NULL;
 812     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 813        of ``const char *''.  We just happen to know that the casts are
 814        safe. */
 815     c = add_set_enum_cmd ("architecture", class_support,
 816                           arches, &set_architecture_string,
 817                           "Set architecture of target.",
 818                           &setlist);
 819     set_cmd_sfunc (c, set_architecture);
 820     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 821     /* Don't use set_from_show - need to print both auto/manual and
 822        current setting. */
 823     add_cmd ("architecture", class_support, show_architecture,
 824              "Show the current target architecture", &showlist);
 825   }
 826 }
 827
 828
 829 /* Initialize a gdbarch info to values that will be automatically
 830    overridden.  Note: Originally, this ``struct info'' was initialized
 831    using memset(0).  Unfortunatly, that ran into problems, namely
 832    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 833    can explicitly set each field to a well defined value is used.  */
 834
 835 void
 836 gdbarch_info_init (struct gdbarch_info *info)
 837 {
 838   memset (info, 0, sizeof (struct gdbarch_info));
 839   info->byte_order = BFD_ENDIAN_UNKNOWN;
 840 }
 841
 842 /* */
 843
 844 extern initialize_file_ftype _initialize_gdbarch_utils;
 845
 846 void
 847 _initialize_gdbarch_utils (void)
 848 {
 849   struct cmd_list_element *c;
 850   c = add_set_enum_cmd ("endian", class_support,
 851                         endian_enum, &set_endian_string,
 852                         "Set endianness of target.",
 853                         &setlist);
 854   set_cmd_sfunc (c, set_endian);
 855   /* Don't use set_from_show - need to print both auto/manual and
 856      current setting. */
 857   add_cmd ("endian", class_support, show_endian,
 858            "Show the current byte-order", &showlist);
 859 }