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 #ifdef SKIP_PROLOGUE_FRAMELESS_P
 158   return ip == SKIP_PROLOGUE_FRAMELESS_P (ip);
 159 #else
 160   return ip == SKIP_PROLOGUE (ip);
 161 #endif
 162 }
 163
 164 /* New/multi-arched targets should use the correct gdbarch field
 165    instead of using this global pointer. */
 166 int
 167 legacy_print_insn (bfd_vma vma, disassemble_info *info)
 168 {
 169   return (*tm_print_insn) (vma, info);
 170 }
 171
 172 /* Helper functions for INNER_THAN */
 173
 174 int
 175 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 176 {
 177   return (lhs < rhs);
 178 }
 179
 180 int
 181 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 182 {
 183   return (lhs > rhs);
 184 }
 185
 186
 187 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 188
 189 const struct floatformat *
 190 default_float_format (struct gdbarch *gdbarch)
 191 {
 192 #if GDB_MULTI_ARCH
 193   int byte_order = gdbarch_byte_order (gdbarch);
 194 #else
 195   int byte_order = TARGET_BYTE_ORDER;
 196 #endif
 197   switch (byte_order)
 198     {
 199     case BFD_ENDIAN_BIG:
 200       return &floatformat_ieee_single_big;
 201     case BFD_ENDIAN_LITTLE:
 202       return &floatformat_ieee_single_little;
 203     default:
 204       internal_error (__FILE__, __LINE__,
 205                       "default_float_format: bad byte order");
 206     }
 207 }
 208
 209
 210 const struct floatformat *
 211 default_double_format (struct gdbarch *gdbarch)
 212 {
 213 #if GDB_MULTI_ARCH
 214   int byte_order = gdbarch_byte_order (gdbarch);
 215 #else
 216   int byte_order = TARGET_BYTE_ORDER;
 217 #endif
 218   switch (byte_order)
 219     {
 220     case BFD_ENDIAN_BIG:
 221       return &floatformat_ieee_double_big;
 222     case BFD_ENDIAN_LITTLE:
 223       return &floatformat_ieee_double_little;
 224     default:
 225       internal_error (__FILE__, __LINE__,
 226                       "default_double_format: bad byte order");
 227     }
 228 }
 229
 230 void
 231 default_print_float_info (void)
 232 {
 233 #ifdef FLOAT_INFO
 234 #if GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL
 235 #error "FLOAT_INFO defined in multi-arch"
 236 #endif
 237   FLOAT_INFO;
 238 #else
 239   printf_filtered ("No floating point info available for this processor.\n");
 240 #endif
 241 }
 242
 243 /* Misc helper functions for targets. */
 244
 245 int
 246 frame_num_args_unknown (struct frame_info *fi)
 247 {
 248   return -1;
 249 }
 250
 251
 252 int
 253 generic_register_convertible_not (int num)
 254 {
 255   return 0;
 256 }
 257
 258
 259 /* Under some ABI's that specify the `struct convention' for returning
 260    structures by value, by the time we've returned from the function,
 261    the return value is sitting there in the caller's buffer, but GDB
 262    has no way to find the address of that buffer.
 263
 264    On such architectures, use this function as your
 265    extract_struct_value_address method.  When asked to a struct
 266    returned by value in this fashion, GDB will print a nice error
 267    message, instead of garbage.  */
 268 CORE_ADDR
 269 generic_cannot_extract_struct_value_address (char *dummy)
 270 {
 271   return 0;
 272 }
 273
 274 int
 275 default_register_sim_regno (int num)
 276 {
 277   return num;
 278 }
 279
 280
 281 CORE_ADDR
 282 core_addr_identity (CORE_ADDR addr)
 283 {
 284   return addr;
 285 }
 286
 287 int
 288 no_op_reg_to_regnum (int reg)
 289 {
 290   return reg;
 291 }
 292
 293 /* For use by frame_args_address and frame_locals_address.  */
 294 CORE_ADDR
 295 default_frame_address (struct frame_info *fi)
 296 {
 297   return fi->frame;
 298 }
 299
 300 /* Default prepare_to_procced().  */
 301 int
 302 default_prepare_to_proceed (int select_it)
 303 {
 304   return 0;
 305 }
 306
 307 /* Generic prepare_to_proceed().  This one should be suitable for most
 308    targets that support threads. */
 309 int
 310 generic_prepare_to_proceed (int select_it)
 311 {
 312   ptid_t wait_ptid;
 313   struct target_waitstatus wait_status;
 314
 315   /* Get the last target status returned by target_wait().  */
 316   get_last_target_status (&wait_ptid, &wait_status);
 317
 318   /* Make sure we were stopped either at a breakpoint, or because
 319      of a Ctrl-C.  */
 320   if (wait_status.kind != TARGET_WAITKIND_STOPPED
 321       || (wait_status.value.sig != TARGET_SIGNAL_TRAP &&
 322           wait_status.value.sig != TARGET_SIGNAL_INT))
 323     {
 324       return 0;
 325     }
 326
 327   if (!ptid_equal (wait_ptid, minus_one_ptid)
 328       && !ptid_equal (inferior_ptid, wait_ptid))
 329     {
 330       /* Switched over from WAIT_PID.  */
 331       CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
 332
 333       if (wait_pc != read_pc ())
 334         {
 335           if (select_it)
 336             {
 337               /* Switch back to WAIT_PID thread.  */
 338               inferior_ptid = wait_ptid;
 339
 340               /* FIXME: This stuff came from switch_to_thread() in
 341                  thread.c (which should probably be a public function).  */
 342               flush_cached_frames ();
 343               registers_changed ();
 344               stop_pc = wait_pc;
 345               select_frame (get_current_frame (), 0);
 346             }
 347           /* We return 1 to indicate that there is a breakpoint here,
 348              so we need to step over it before continuing to avoid
 349              hitting it straight away. */
 350           if (breakpoint_here_p (wait_pc))
 351             {
 352               return 1;
 353             }
 354         }
 355     }
 356   return 0;
 357
 358 }
 359
 360 void
 361 init_frame_pc_noop (int fromleaf, struct frame_info *prev)
 362 {
 363   return;
 364 }
 365
 366 void
 367 init_frame_pc_default (int fromleaf, struct frame_info *prev)
 368 {
 369   if (fromleaf)
 370     prev->pc = SAVED_PC_AFTER_CALL (prev->next);
 371   else if (prev->next != NULL)
 372     prev->pc = FRAME_SAVED_PC (prev->next);
 373   else
 374     prev->pc = read_pc ();
 375 }
 376
 377 void
 378 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 379 {
 380   return;
 381 }
 382
 383 void
 384 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 385 {
 386   return;
 387 }
 388
 389 int
 390 cannot_register_not (int regnum)
 391 {
 392   return 0;
 393 }
 394
 395 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 396    there is an FP_REGNUM and that it is the same, cooked or raw.  */
 397
 398 void
 399 legacy_virtual_frame_pointer (CORE_ADDR pc,
 400                               int *frame_regnum,
 401                               LONGEST *frame_offset)
 402 {
 403   gdb_assert (FP_REGNUM >= 0);
 404   *frame_regnum = FP_REGNUM;
 405   *frame_offset = 0;
 406 }
 407
 408 /* Assume the world is flat.  Every register is large enough to fit a
 409    target integer.  */
 410
 411 int
 412 generic_register_raw_size (int regnum)
 413 {
 414   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 415   return TARGET_INT_BIT / HOST_CHAR_BIT;
 416 }
 417
 418 /* Assume the virtual size corresponds to the virtual type.  */
 419
 420 int
 421 generic_register_virtual_size (int regnum)
 422 {
 423   return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (regnum));
 424 }
 425
 426 \f
 427 /* Functions to manipulate the endianness of the target.  */
 428
 429 /* ``target_byte_order'' is only used when non- multi-arch.
 430    Multi-arch targets obtain the current byte order using the
 431    TARGET_BYTE_ORDER gdbarch method.
 432
 433    The choice of initial value is entirely arbitrary.  During startup,
 434    the function initialize_current_architecture() updates this value
 435    based on default byte-order information extracted from BFD.  */
 436 int target_byte_order = BFD_ENDIAN_BIG;
 437 int target_byte_order_auto = 1;
 438
 439 static const char endian_big[] = "big";
 440 static const char endian_little[] = "little";
 441 static const char endian_auto[] = "auto";
 442 static const char *endian_enum[] =
 443 {
 444   endian_big,
 445   endian_little,
 446   endian_auto,
 447   NULL,
 448 };
 449 static const char *set_endian_string;
 450
 451 /* Called by ``show endian''.  */
 452
 453 static void
 454 show_endian (char *args, int from_tty)
 455 {
 456   if (TARGET_BYTE_ORDER_AUTO)
 457     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 458                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 459   else
 460     printf_unfiltered ("The target is assumed to be %s endian\n",
 461                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 462 }
 463
 464 static void
 465 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 466 {
 467   if (set_endian_string == endian_auto)
 468     {
 469       target_byte_order_auto = 1;
 470     }
 471   else if (set_endian_string == endian_little)
 472     {
 473       target_byte_order_auto = 0;
 474       if (GDB_MULTI_ARCH)
 475         {
 476           struct gdbarch_info info;
 477           gdbarch_info_init (&info);
 478           info.byte_order = BFD_ENDIAN_LITTLE;
 479           if (! gdbarch_update_p (info))
 480             {
 481               printf_unfiltered ("Little endian target not supported by GDB\n");
 482             }
 483         }
 484       else
 485         {
 486           target_byte_order = BFD_ENDIAN_LITTLE;
 487         }
 488     }
 489   else if (set_endian_string == endian_big)
 490     {
 491       target_byte_order_auto = 0;
 492       if (GDB_MULTI_ARCH)
 493         {
 494           struct gdbarch_info info;
 495           gdbarch_info_init (&info);
 496           info.byte_order = BFD_ENDIAN_BIG;
 497           if (! gdbarch_update_p (info))
 498             {
 499               printf_unfiltered ("Big endian target not supported by GDB\n");
 500             }
 501         }
 502       else
 503         {
 504           target_byte_order = BFD_ENDIAN_BIG;
 505         }
 506     }
 507   else
 508     internal_error (__FILE__, __LINE__,
 509                     "set_endian: bad value");
 510   show_endian (NULL, from_tty);
 511 }
 512
 513 /* Set the endianness from a BFD.  */
 514
 515 static void
 516 set_endian_from_file (bfd *abfd)
 517 {
 518   int want;
 519   if (GDB_MULTI_ARCH)
 520     internal_error (__FILE__, __LINE__,
 521                     "set_endian_from_file: not for multi-arch");
 522   if (bfd_big_endian (abfd))
 523     want = BFD_ENDIAN_BIG;
 524   else
 525     want = BFD_ENDIAN_LITTLE;
 526   if (TARGET_BYTE_ORDER_AUTO)
 527     target_byte_order = want;
 528   else if (TARGET_BYTE_ORDER != want)
 529     warning ("%s endian file does not match %s endian target.",
 530              want == BFD_ENDIAN_BIG ? "big" : "little",
 531              TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
 532 }
 533
 534
 535 /* Functions to manipulate the architecture of the target */
 536
 537 enum set_arch { set_arch_auto, set_arch_manual };
 538
 539 int target_architecture_auto = 1;
 540
 541 const char *set_architecture_string;
 542
 543 /* Old way of changing the current architecture. */
 544
 545 extern const struct bfd_arch_info bfd_default_arch_struct;
 546 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 547 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 548
 549 static int
 550 arch_ok (const struct bfd_arch_info *arch)
 551 {
 552   if (GDB_MULTI_ARCH)
 553     internal_error (__FILE__, __LINE__,
 554                     "arch_ok: not multi-arched");
 555   /* Should be performing the more basic check that the binary is
 556      compatible with GDB. */
 557   /* Check with the target that the architecture is valid. */
 558   return (target_architecture_hook == NULL
 559           || target_architecture_hook (arch));
 560 }
 561
 562 static void
 563 set_arch (const struct bfd_arch_info *arch,
 564           enum set_arch type)
 565 {
 566   if (GDB_MULTI_ARCH)
 567     internal_error (__FILE__, __LINE__,
 568                     "set_arch: not multi-arched");
 569   switch (type)
 570     {
 571     case set_arch_auto:
 572       if (!arch_ok (arch))
 573         warning ("Target may not support %s architecture",
 574                  arch->printable_name);
 575       target_architecture = arch;
 576       break;
 577     case set_arch_manual:
 578       if (!arch_ok (arch))
 579         {
 580           printf_unfiltered ("Target does not support `%s' architecture.\n",
 581                              arch->printable_name);
 582         }
 583       else
 584         {
 585           target_architecture_auto = 0;
 586           target_architecture = arch;
 587         }
 588       break;
 589     }
 590   if (gdbarch_debug)
 591     gdbarch_dump (current_gdbarch, gdb_stdlog);
 592 }
 593
 594 /* Set the architecture from arch/machine (deprecated) */
 595
 596 void
 597 set_architecture_from_arch_mach (enum bfd_architecture arch,
 598                                  unsigned long mach)
 599 {
 600   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 601   if (GDB_MULTI_ARCH)
 602     internal_error (__FILE__, __LINE__,
 603                     "set_architecture_from_arch_mach: not multi-arched");
 604   if (wanted != NULL)
 605     set_arch (wanted, set_arch_manual);
 606   else
 607     internal_error (__FILE__, __LINE__,
 608                     "gdbarch: hardwired architecture/machine not recognized");
 609 }
 610
 611 /* Set the architecture from a BFD (deprecated) */
 612
 613 static void
 614 set_architecture_from_file (bfd *abfd)
 615 {
 616   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 617   if (GDB_MULTI_ARCH)
 618     internal_error (__FILE__, __LINE__,
 619                     "set_architecture_from_file: not multi-arched");
 620   if (target_architecture_auto)
 621     {
 622       set_arch (wanted, set_arch_auto);
 623     }
 624   else if (wanted != target_architecture)
 625     {
 626       warning ("%s architecture file may be incompatible with %s target.",
 627                wanted->printable_name,
 628                target_architecture->printable_name);
 629     }
 630 }
 631
 632
 633 /* Called if the user enters ``show architecture'' without an
 634    argument. */
 635
 636 static void
 637 show_architecture (char *args, int from_tty)
 638 {
 639   const char *arch;
 640   arch = TARGET_ARCHITECTURE->printable_name;
 641   if (target_architecture_auto)
 642     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 643   else
 644     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 645 }
 646
 647
 648 /* Called if the user enters ``set architecture'' with or without an
 649    argument. */
 650
 651 static void
 652 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 653 {
 654   if (strcmp (set_architecture_string, "auto") == 0)
 655     {
 656       target_architecture_auto = 1;
 657     }
 658   else if (GDB_MULTI_ARCH)
 659     {
 660       struct gdbarch_info info;
 661       gdbarch_info_init (&info);
 662       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 663       if (info.bfd_arch_info == NULL)
 664         internal_error (__FILE__, __LINE__,
 665                         "set_architecture: bfd_scan_arch failed");
 666       if (gdbarch_update_p (info))
 667         target_architecture_auto = 0;
 668       else
 669         printf_unfiltered ("Architecture `%s' not recognized.\n",
 670                            set_architecture_string);
 671     }
 672   else
 673     {
 674       const struct bfd_arch_info *arch
 675         = bfd_scan_arch (set_architecture_string);
 676       if (arch == NULL)
 677         internal_error (__FILE__, __LINE__,
 678                         "set_architecture: bfd_scan_arch failed");
 679       set_arch (arch, set_arch_manual);
 680     }
 681   show_architecture (NULL, from_tty);
 682 }
 683
 684 /* Set the dynamic target-system-dependent parameters (architecture,
 685    byte-order) using information found in the BFD */
 686
 687 void
 688 set_gdbarch_from_file (bfd *abfd)
 689 {
 690   if (GDB_MULTI_ARCH)
 691     {
 692       struct gdbarch_info info;
 693       gdbarch_info_init (&info);
 694       info.abfd = abfd;
 695       if (! gdbarch_update_p (info))
 696         error ("Architecture of file not recognized.\n");
 697     }
 698   else
 699     {
 700       set_architecture_from_file (abfd);
 701       set_endian_from_file (abfd);
 702     }
 703 }
 704
 705 /* Initialize the current architecture.  Update the ``set
 706    architecture'' command so that it specifies a list of valid
 707    architectures.  */
 708
 709 #ifdef DEFAULT_BFD_ARCH
 710 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 711 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 712 #else
 713 static const bfd_arch_info_type *default_bfd_arch;
 714 #endif
 715
 716 #ifdef DEFAULT_BFD_VEC
 717 extern const bfd_target DEFAULT_BFD_VEC;
 718 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 719 #else
 720 static const bfd_target *default_bfd_vec;
 721 #endif
 722
 723 void
 724 initialize_current_architecture (void)
 725 {
 726   const char **arches = gdbarch_printable_names ();
 727
 728   /* determine a default architecture and byte order. */
 729   struct gdbarch_info info;
 730   gdbarch_info_init (&info);
 731
 732   /* Find a default architecture. */
 733   if (info.bfd_arch_info == NULL
 734       && default_bfd_arch != NULL)
 735     info.bfd_arch_info = default_bfd_arch;
 736   if (info.bfd_arch_info == NULL)
 737     {
 738       /* Choose the architecture by taking the first one
 739          alphabetically. */
 740       const char *chosen = arches[0];
 741       const char **arch;
 742       for (arch = arches; *arch != NULL; arch++)
 743         {
 744           if (strcmp (*arch, chosen) < 0)
 745             chosen = *arch;
 746         }
 747       if (chosen == NULL)
 748         internal_error (__FILE__, __LINE__,
 749                         "initialize_current_architecture: No arch");
 750       info.bfd_arch_info = bfd_scan_arch (chosen);
 751       if (info.bfd_arch_info == NULL)
 752         internal_error (__FILE__, __LINE__,
 753                         "initialize_current_architecture: Arch not found");
 754     }
 755
 756   /* Take several guesses at a byte order.  */
 757   if (info.byte_order == BFD_ENDIAN_UNKNOWN
 758       && default_bfd_vec != NULL)
 759     {
 760       /* Extract BFD's default vector's byte order. */
 761       switch (default_bfd_vec->byteorder)
 762         {
 763         case BFD_ENDIAN_BIG:
 764           info.byte_order = BFD_ENDIAN_BIG;
 765           break;
 766         case BFD_ENDIAN_LITTLE:
 767           info.byte_order = BFD_ENDIAN_LITTLE;
 768           break;
 769         default:
 770           break;
 771         }
 772     }
 773   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 774     {
 775       /* look for ``*el-*'' in the target name. */
 776       const char *chp;
 777       chp = strchr (target_name, '-');
 778       if (chp != NULL
 779           && chp - 2 >= target_name
 780           && strncmp (chp - 2, "el", 2) == 0)
 781         info.byte_order = BFD_ENDIAN_LITTLE;
 782     }
 783   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 784     {
 785       /* Wire it to big-endian!!! */
 786       info.byte_order = BFD_ENDIAN_BIG;
 787     }
 788
 789   if (GDB_MULTI_ARCH)
 790     {
 791       if (! gdbarch_update_p (info))
 792         {
 793           internal_error (__FILE__, __LINE__,
 794                           "initialize_current_architecture: Selection of initial architecture failed");
 795         }
 796     }
 797   else
 798     {
 799       /* If the multi-arch logic comes up with a byte-order (from BFD)
 800          use it for the non-multi-arch case.  */
 801       if (info.byte_order != BFD_ENDIAN_UNKNOWN)
 802         target_byte_order = info.byte_order;
 803       initialize_non_multiarch ();
 804     }
 805
 806   /* Create the ``set architecture'' command appending ``auto'' to the
 807      list of architectures. */
 808   {
 809     struct cmd_list_element *c;
 810     /* Append ``auto''. */
 811     int nr;
 812     for (nr = 0; arches[nr] != NULL; nr++);
 813     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 814     arches[nr + 0] = "auto";
 815     arches[nr + 1] = NULL;
 816     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 817        of ``const char *''.  We just happen to know that the casts are
 818        safe. */
 819     c = add_set_enum_cmd ("architecture", class_support,
 820                           arches, &set_architecture_string,
 821                           "Set architecture of target.",
 822                           &setlist);
 823     set_cmd_sfunc (c, set_architecture);
 824     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 825     /* Don't use set_from_show - need to print both auto/manual and
 826        current setting. */
 827     add_cmd ("architecture", class_support, show_architecture,
 828              "Show the current target architecture", &showlist);
 829   }
 830 }
 831
 832
 833 /* Initialize a gdbarch info to values that will be automatically
 834    overridden.  Note: Originally, this ``struct info'' was initialized
 835    using memset(0).  Unfortunatly, that ran into problems, namely
 836    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 837    can explicitly set each field to a well defined value is used.  */
 838
 839 void
 840 gdbarch_info_init (struct gdbarch_info *info)
 841 {
 842   memset (info, 0, sizeof (struct gdbarch_info));
 843   info->byte_order = BFD_ENDIAN_UNKNOWN;
 844 }
 845
 846 /* */
 847
 848 extern initialize_file_ftype _initialize_gdbarch_utils;
 849
 850 void
 851 _initialize_gdbarch_utils (void)
 852 {
 853   struct cmd_list_element *c;
 854   c = add_set_enum_cmd ("endian", class_support,
 855                         endian_enum, &set_endian_string,
 856                         "Set endianness of target.",
 857                         &setlist);
 858   set_cmd_sfunc (c, set_endian);
 859   /* Don't use set_from_show - need to print both auto/manual and
 860      current setting. */
 861   add_cmd ("endian", class_support, show_endian,
 862            "Show the current byte-order", &showlist);
 863 }