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 #include "sim-regno.h"
  46
  47 #include "version.h"
  48
  49 #include "floatformat.h"
  50
  51 /* Use the program counter to determine the contents and size
  52    of a breakpoint instruction.  If no target-dependent macro
  53    BREAKPOINT_FROM_PC has been defined to implement this function,
  54    assume that the breakpoint doesn't depend on the PC, and
  55    use the values of the BIG_BREAKPOINT and LITTLE_BREAKPOINT macros.
  56    Return a pointer to a string of bytes that encode a breakpoint
  57    instruction, stores the length of the string to *lenptr,
  58    and optionally adjust the pc to point to the correct memory location
  59    for inserting the breakpoint.  */
  60
  61 const unsigned char *
  62 legacy_breakpoint_from_pc (CORE_ADDR * pcptr, int *lenptr)
  63 {
  64   /* {BIG_,LITTLE_}BREAKPOINT is the sequence of bytes we insert for a
  65      breakpoint.  On some machines, breakpoints are handled by the
  66      target environment and we don't have to worry about them here.  */
  67 #ifdef BIG_BREAKPOINT
  68   if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
  69     {
  70       static unsigned char big_break_insn[] = BIG_BREAKPOINT;
  71       *lenptr = sizeof (big_break_insn);
  72       return big_break_insn;
  73     }
  74 #endif
  75 #ifdef LITTLE_BREAKPOINT
  76   if (TARGET_BYTE_ORDER != BFD_ENDIAN_BIG)
  77     {
  78       static unsigned char little_break_insn[] = LITTLE_BREAKPOINT;
  79       *lenptr = sizeof (little_break_insn);
  80       return little_break_insn;
  81     }
  82 #endif
  83 #ifdef BREAKPOINT
  84   {
  85     static unsigned char break_insn[] = BREAKPOINT;
  86     *lenptr = sizeof (break_insn);
  87     return break_insn;
  88   }
  89 #endif
  90   *lenptr = 0;
  91   return NULL;
  92 }
  93
  94 int
  95 legacy_register_sim_regno (int regnum)
  96 {
  97   /* Only makes sense to supply raw registers.  */
  98   gdb_assert (regnum >= 0 && regnum < NUM_REGS);
  99   /* NOTE: cagney/2002-05-13: The old code did it this way and it is
 100      suspected that some GDB/SIM combinations may rely on this
 101      behavour.  The default should be one2one_register_sim_regno
 102      (below).  */
 103   if (REGISTER_NAME (regnum) != NULL
 104       && REGISTER_NAME (regnum)[0] != '\0')
 105     return regnum;
 106   else
 107     return LEGACY_SIM_REGNO_IGNORE;
 108 }
 109
 110 int
 111 generic_frameless_function_invocation_not (struct frame_info *fi)
 112 {
 113   return 0;
 114 }
 115
 116 int
 117 generic_return_value_on_stack_not (struct type *type)
 118 {
 119   return 0;
 120 }
 121
 122 CORE_ADDR
 123 generic_skip_trampoline_code (CORE_ADDR pc)
 124 {
 125   return 0;
 126 }
 127
 128 int
 129 generic_in_solib_call_trampoline (CORE_ADDR pc, char *name)
 130 {
 131   return 0;
 132 }
 133
 134 int
 135 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 136 {
 137   return 0;
 138 }
 139
 140 char *
 141 legacy_register_name (int i)
 142 {
 143 #ifdef REGISTER_NAMES
 144   static char *names[] = REGISTER_NAMES;
 145   if (i < 0 || i >= (sizeof (names) / sizeof (*names)))
 146     return NULL;
 147   else
 148     return names[i];
 149 #else
 150   internal_error (__FILE__, __LINE__,
 151                   "legacy_register_name: called.");
 152   return NULL;
 153 #endif
 154 }
 155
 156 #if defined (CALL_DUMMY)
 157 LONGEST legacy_call_dummy_words[] = CALL_DUMMY;
 158 #else
 159 LONGEST legacy_call_dummy_words[1];
 160 #endif
 161 int legacy_sizeof_call_dummy_words = sizeof (legacy_call_dummy_words);
 162
 163 void
 164 generic_remote_translate_xfer_address (CORE_ADDR gdb_addr, int gdb_len,
 165                                        CORE_ADDR * rem_addr, int *rem_len)
 166 {
 167   *rem_addr = gdb_addr;
 168   *rem_len = gdb_len;
 169 }
 170
 171 int
 172 generic_prologue_frameless_p (CORE_ADDR ip)
 173 {
 174   return ip == SKIP_PROLOGUE (ip);
 175 }
 176
 177 /* New/multi-arched targets should use the correct gdbarch field
 178    instead of using this global pointer. */
 179 int
 180 legacy_print_insn (bfd_vma vma, disassemble_info *info)
 181 {
 182   return (*tm_print_insn) (vma, info);
 183 }
 184
 185 /* Helper functions for INNER_THAN */
 186
 187 int
 188 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 189 {
 190   return (lhs < rhs);
 191 }
 192
 193 int
 194 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 195 {
 196   return (lhs > rhs);
 197 }
 198
 199
 200 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 201
 202 const struct floatformat *
 203 default_float_format (struct gdbarch *gdbarch)
 204 {
 205 #if GDB_MULTI_ARCH
 206   int byte_order = gdbarch_byte_order (gdbarch);
 207 #else
 208   int byte_order = TARGET_BYTE_ORDER;
 209 #endif
 210   switch (byte_order)
 211     {
 212     case BFD_ENDIAN_BIG:
 213       return &floatformat_ieee_single_big;
 214     case BFD_ENDIAN_LITTLE:
 215       return &floatformat_ieee_single_little;
 216     default:
 217       internal_error (__FILE__, __LINE__,
 218                       "default_float_format: bad byte order");
 219     }
 220 }
 221
 222
 223 const struct floatformat *
 224 default_double_format (struct gdbarch *gdbarch)
 225 {
 226 #if GDB_MULTI_ARCH
 227   int byte_order = gdbarch_byte_order (gdbarch);
 228 #else
 229   int byte_order = TARGET_BYTE_ORDER;
 230 #endif
 231   switch (byte_order)
 232     {
 233     case BFD_ENDIAN_BIG:
 234       return &floatformat_ieee_double_big;
 235     case BFD_ENDIAN_LITTLE:
 236       return &floatformat_ieee_double_little;
 237     default:
 238       internal_error (__FILE__, __LINE__,
 239                       "default_double_format: bad byte order");
 240     }
 241 }
 242
 243 void
 244 default_print_float_info (void)
 245 {
 246 #ifdef FLOAT_INFO
 247 #if GDB_MULTI_ARCH > GDB_MULTI_ARCH_PARTIAL
 248 #error "FLOAT_INFO defined in multi-arch"
 249 #endif
 250   FLOAT_INFO;
 251 #else
 252   printf_filtered ("No floating point info available for this processor.\n");
 253 #endif
 254 }
 255
 256 /* Misc helper functions for targets. */
 257
 258 int
 259 frame_num_args_unknown (struct frame_info *fi)
 260 {
 261   return -1;
 262 }
 263
 264
 265 int
 266 generic_register_convertible_not (int num)
 267 {
 268   return 0;
 269 }
 270
 271
 272 /* Under some ABI's that specify the `struct convention' for returning
 273    structures by value, by the time we've returned from the function,
 274    the return value is sitting there in the caller's buffer, but GDB
 275    has no way to find the address of that buffer.
 276
 277    On such architectures, use this function as your
 278    extract_struct_value_address method.  When asked to a struct
 279    returned by value in this fashion, GDB will print a nice error
 280    message, instead of garbage.  */
 281 CORE_ADDR
 282 generic_cannot_extract_struct_value_address (char *dummy)
 283 {
 284   return 0;
 285 }
 286
 287 CORE_ADDR
 288 core_addr_identity (CORE_ADDR addr)
 289 {
 290   return addr;
 291 }
 292
 293 int
 294 no_op_reg_to_regnum (int reg)
 295 {
 296   return reg;
 297 }
 298
 299 /* For use by frame_args_address and frame_locals_address.  */
 300 CORE_ADDR
 301 default_frame_address (struct frame_info *fi)
 302 {
 303   return fi->frame;
 304 }
 305
 306 /* Default prepare_to_procced().  */
 307 int
 308 default_prepare_to_proceed (int select_it)
 309 {
 310   return 0;
 311 }
 312
 313 /* Generic prepare_to_proceed().  This one should be suitable for most
 314    targets that support threads. */
 315 int
 316 generic_prepare_to_proceed (int select_it)
 317 {
 318   ptid_t wait_ptid;
 319   struct target_waitstatus wait_status;
 320
 321   /* Get the last target status returned by target_wait().  */
 322   get_last_target_status (&wait_ptid, &wait_status);
 323
 324   /* Make sure we were stopped either at a breakpoint, or because
 325      of a Ctrl-C.  */
 326   if (wait_status.kind != TARGET_WAITKIND_STOPPED
 327       || (wait_status.value.sig != TARGET_SIGNAL_TRAP &&
 328           wait_status.value.sig != TARGET_SIGNAL_INT))
 329     {
 330       return 0;
 331     }
 332
 333   if (!ptid_equal (wait_ptid, minus_one_ptid)
 334       && !ptid_equal (inferior_ptid, wait_ptid))
 335     {
 336       /* Switched over from WAIT_PID.  */
 337       CORE_ADDR wait_pc = read_pc_pid (wait_ptid);
 338
 339       if (wait_pc != read_pc ())
 340         {
 341           if (select_it)
 342             {
 343               /* Switch back to WAIT_PID thread.  */
 344               inferior_ptid = wait_ptid;
 345
 346               /* FIXME: This stuff came from switch_to_thread() in
 347                  thread.c (which should probably be a public function).  */
 348               flush_cached_frames ();
 349               registers_changed ();
 350               stop_pc = wait_pc;
 351               select_frame (get_current_frame ());
 352             }
 353           /* We return 1 to indicate that there is a breakpoint here,
 354              so we need to step over it before continuing to avoid
 355              hitting it straight away. */
 356           if (breakpoint_here_p (wait_pc))
 357             {
 358               return 1;
 359             }
 360         }
 361     }
 362   return 0;
 363
 364 }
 365
 366 void
 367 init_frame_pc_noop (int fromleaf, struct frame_info *prev)
 368 {
 369   return;
 370 }
 371
 372 void
 373 init_frame_pc_default (int fromleaf, struct frame_info *prev)
 374 {
 375   if (fromleaf)
 376     prev->pc = SAVED_PC_AFTER_CALL (prev->next);
 377   else if (prev->next != NULL)
 378     prev->pc = FRAME_SAVED_PC (prev->next);
 379   else
 380     prev->pc = read_pc ();
 381 }
 382
 383 void
 384 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 385 {
 386   return;
 387 }
 388
 389 void
 390 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 391 {
 392   return;
 393 }
 394
 395 int
 396 cannot_register_not (int regnum)
 397 {
 398   return 0;
 399 }
 400
 401 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 402    there is an FP_REGNUM and that it is the same, cooked or raw.  */
 403
 404 void
 405 legacy_virtual_frame_pointer (CORE_ADDR pc,
 406                               int *frame_regnum,
 407                               LONGEST *frame_offset)
 408 {
 409   gdb_assert (FP_REGNUM >= 0);
 410   *frame_regnum = FP_REGNUM;
 411   *frame_offset = 0;
 412 }
 413
 414 /* Assume the world is sane, every register's virtual and real size
 415    is identical.  */
 416
 417 int
 418 generic_register_size (int regnum)
 419 {
 420   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 421   return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (regnum));
 422 }
 423
 424 #if !defined (IN_SIGTRAMP)
 425 #if defined (SIGTRAMP_START)
 426 #define IN_SIGTRAMP(pc, name) \
 427        ((pc) >= SIGTRAMP_START(pc)   \
 428         && (pc) < SIGTRAMP_END(pc) \
 429         )
 430 #else
 431 #define IN_SIGTRAMP(pc, name) \
 432        (name && STREQ ("_sigtramp", name))
 433 #endif
 434 #endif
 435 \f
 436 int
 437 legacy_pc_in_sigtramp (CORE_ADDR pc, char *name)
 438 {
 439   return IN_SIGTRAMP(pc, name);
 440 }
 441
 442 int
 443 legacy_convert_register_p (int regnum)
 444 {
 445   return REGISTER_CONVERTIBLE (regnum);
 446 }
 447
 448 void
 449 legacy_register_to_value (int regnum, struct type *type,
 450                           char *from, char *to)
 451 {
 452   REGISTER_CONVERT_TO_VIRTUAL (regnum, type, from, to);
 453 }
 454
 455 void
 456 legacy_value_to_register (struct type *type, int regnum,
 457                           char *from, char *to)
 458 {
 459   REGISTER_CONVERT_TO_RAW (type, regnum, from, to);
 460 }
 461
 462 \f
 463 /* Functions to manipulate the endianness of the target.  */
 464
 465 /* ``target_byte_order'' is only used when non- multi-arch.
 466    Multi-arch targets obtain the current byte order using the
 467    TARGET_BYTE_ORDER gdbarch method.
 468
 469    The choice of initial value is entirely arbitrary.  During startup,
 470    the function initialize_current_architecture() updates this value
 471    based on default byte-order information extracted from BFD.  */
 472 int target_byte_order = BFD_ENDIAN_BIG;
 473 int target_byte_order_auto = 1;
 474
 475 static const char endian_big[] = "big";
 476 static const char endian_little[] = "little";
 477 static const char endian_auto[] = "auto";
 478 static const char *endian_enum[] =
 479 {
 480   endian_big,
 481   endian_little,
 482   endian_auto,
 483   NULL,
 484 };
 485 static const char *set_endian_string;
 486
 487 /* Called by ``show endian''.  */
 488
 489 static void
 490 show_endian (char *args, int from_tty)
 491 {
 492   if (TARGET_BYTE_ORDER_AUTO)
 493     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 494                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 495   else
 496     printf_unfiltered ("The target is assumed to be %s endian\n",
 497                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 498 }
 499
 500 static void
 501 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 502 {
 503   if (set_endian_string == endian_auto)
 504     {
 505       target_byte_order_auto = 1;
 506     }
 507   else if (set_endian_string == endian_little)
 508     {
 509       target_byte_order_auto = 0;
 510       if (GDB_MULTI_ARCH)
 511         {
 512           struct gdbarch_info info;
 513           gdbarch_info_init (&info);
 514           info.byte_order = BFD_ENDIAN_LITTLE;
 515           if (! gdbarch_update_p (info))
 516             {
 517               printf_unfiltered ("Little endian target not supported by GDB\n");
 518             }
 519         }
 520       else
 521         {
 522           target_byte_order = BFD_ENDIAN_LITTLE;
 523         }
 524     }
 525   else if (set_endian_string == endian_big)
 526     {
 527       target_byte_order_auto = 0;
 528       if (GDB_MULTI_ARCH)
 529         {
 530           struct gdbarch_info info;
 531           gdbarch_info_init (&info);
 532           info.byte_order = BFD_ENDIAN_BIG;
 533           if (! gdbarch_update_p (info))
 534             {
 535               printf_unfiltered ("Big endian target not supported by GDB\n");
 536             }
 537         }
 538       else
 539         {
 540           target_byte_order = BFD_ENDIAN_BIG;
 541         }
 542     }
 543   else
 544     internal_error (__FILE__, __LINE__,
 545                     "set_endian: bad value");
 546   show_endian (NULL, from_tty);
 547 }
 548
 549 /* Set the endianness from a BFD.  */
 550
 551 static void
 552 set_endian_from_file (bfd *abfd)
 553 {
 554   int want;
 555   if (GDB_MULTI_ARCH)
 556     internal_error (__FILE__, __LINE__,
 557                     "set_endian_from_file: not for multi-arch");
 558   if (bfd_big_endian (abfd))
 559     want = BFD_ENDIAN_BIG;
 560   else
 561     want = BFD_ENDIAN_LITTLE;
 562   if (TARGET_BYTE_ORDER_AUTO)
 563     target_byte_order = want;
 564   else if (TARGET_BYTE_ORDER != want)
 565     warning ("%s endian file does not match %s endian target.",
 566              want == BFD_ENDIAN_BIG ? "big" : "little",
 567              TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little");
 568 }
 569
 570
 571 /* Functions to manipulate the architecture of the target */
 572
 573 enum set_arch { set_arch_auto, set_arch_manual };
 574
 575 int target_architecture_auto = 1;
 576
 577 const char *set_architecture_string;
 578
 579 /* Old way of changing the current architecture. */
 580
 581 extern const struct bfd_arch_info bfd_default_arch_struct;
 582 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 583 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 584
 585 static int
 586 arch_ok (const struct bfd_arch_info *arch)
 587 {
 588   if (GDB_MULTI_ARCH)
 589     internal_error (__FILE__, __LINE__,
 590                     "arch_ok: not multi-arched");
 591   /* Should be performing the more basic check that the binary is
 592      compatible with GDB. */
 593   /* Check with the target that the architecture is valid. */
 594   return (target_architecture_hook == NULL
 595           || target_architecture_hook (arch));
 596 }
 597
 598 static void
 599 set_arch (const struct bfd_arch_info *arch,
 600           enum set_arch type)
 601 {
 602   if (GDB_MULTI_ARCH)
 603     internal_error (__FILE__, __LINE__,
 604                     "set_arch: not multi-arched");
 605   switch (type)
 606     {
 607     case set_arch_auto:
 608       if (!arch_ok (arch))
 609         warning ("Target may not support %s architecture",
 610                  arch->printable_name);
 611       target_architecture = arch;
 612       break;
 613     case set_arch_manual:
 614       if (!arch_ok (arch))
 615         {
 616           printf_unfiltered ("Target does not support `%s' architecture.\n",
 617                              arch->printable_name);
 618         }
 619       else
 620         {
 621           target_architecture_auto = 0;
 622           target_architecture = arch;
 623         }
 624       break;
 625     }
 626   if (gdbarch_debug)
 627     gdbarch_dump (current_gdbarch, gdb_stdlog);
 628 }
 629
 630 /* Set the architecture from arch/machine (deprecated) */
 631
 632 void
 633 set_architecture_from_arch_mach (enum bfd_architecture arch,
 634                                  unsigned long mach)
 635 {
 636   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 637   if (GDB_MULTI_ARCH)
 638     internal_error (__FILE__, __LINE__,
 639                     "set_architecture_from_arch_mach: not multi-arched");
 640   if (wanted != NULL)
 641     set_arch (wanted, set_arch_manual);
 642   else
 643     internal_error (__FILE__, __LINE__,
 644                     "gdbarch: hardwired architecture/machine not recognized");
 645 }
 646
 647 /* Set the architecture from a BFD (deprecated) */
 648
 649 static void
 650 set_architecture_from_file (bfd *abfd)
 651 {
 652   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 653   if (GDB_MULTI_ARCH)
 654     internal_error (__FILE__, __LINE__,
 655                     "set_architecture_from_file: not multi-arched");
 656   if (target_architecture_auto)
 657     {
 658       set_arch (wanted, set_arch_auto);
 659     }
 660   else if (wanted != target_architecture)
 661     {
 662       warning ("%s architecture file may be incompatible with %s target.",
 663                wanted->printable_name,
 664                target_architecture->printable_name);
 665     }
 666 }
 667
 668
 669 /* Called if the user enters ``show architecture'' without an
 670    argument. */
 671
 672 static void
 673 show_architecture (char *args, int from_tty)
 674 {
 675   const char *arch;
 676   arch = TARGET_ARCHITECTURE->printable_name;
 677   if (target_architecture_auto)
 678     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 679   else
 680     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 681 }
 682
 683
 684 /* Called if the user enters ``set architecture'' with or without an
 685    argument. */
 686
 687 static void
 688 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 689 {
 690   if (strcmp (set_architecture_string, "auto") == 0)
 691     {
 692       target_architecture_auto = 1;
 693     }
 694   else if (GDB_MULTI_ARCH)
 695     {
 696       struct gdbarch_info info;
 697       gdbarch_info_init (&info);
 698       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 699       if (info.bfd_arch_info == NULL)
 700         internal_error (__FILE__, __LINE__,
 701                         "set_architecture: bfd_scan_arch failed");
 702       if (gdbarch_update_p (info))
 703         target_architecture_auto = 0;
 704       else
 705         printf_unfiltered ("Architecture `%s' not recognized.\n",
 706                            set_architecture_string);
 707     }
 708   else
 709     {
 710       const struct bfd_arch_info *arch
 711         = bfd_scan_arch (set_architecture_string);
 712       if (arch == NULL)
 713         internal_error (__FILE__, __LINE__,
 714                         "set_architecture: bfd_scan_arch failed");
 715       set_arch (arch, set_arch_manual);
 716     }
 717   show_architecture (NULL, from_tty);
 718 }
 719
 720 /* Set the dynamic target-system-dependent parameters (architecture,
 721    byte-order) using information found in the BFD */
 722
 723 void
 724 set_gdbarch_from_file (bfd *abfd)
 725 {
 726   if (GDB_MULTI_ARCH)
 727     {
 728       struct gdbarch_info info;
 729       gdbarch_info_init (&info);
 730       info.abfd = abfd;
 731       if (! gdbarch_update_p (info))
 732         error ("Architecture of file not recognized.\n");
 733     }
 734   else
 735     {
 736       set_architecture_from_file (abfd);
 737       set_endian_from_file (abfd);
 738     }
 739 }
 740
 741 /* Initialize the current architecture.  Update the ``set
 742    architecture'' command so that it specifies a list of valid
 743    architectures.  */
 744
 745 #ifdef DEFAULT_BFD_ARCH
 746 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 747 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 748 #else
 749 static const bfd_arch_info_type *default_bfd_arch;
 750 #endif
 751
 752 #ifdef DEFAULT_BFD_VEC
 753 extern const bfd_target DEFAULT_BFD_VEC;
 754 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 755 #else
 756 static const bfd_target *default_bfd_vec;
 757 #endif
 758
 759 void
 760 initialize_current_architecture (void)
 761 {
 762   const char **arches = gdbarch_printable_names ();
 763
 764   /* determine a default architecture and byte order. */
 765   struct gdbarch_info info;
 766   gdbarch_info_init (&info);
 767
 768   /* Find a default architecture. */
 769   if (info.bfd_arch_info == NULL
 770       && default_bfd_arch != NULL)
 771     info.bfd_arch_info = default_bfd_arch;
 772   if (info.bfd_arch_info == NULL)
 773     {
 774       /* Choose the architecture by taking the first one
 775          alphabetically. */
 776       const char *chosen = arches[0];
 777       const char **arch;
 778       for (arch = arches; *arch != NULL; arch++)
 779         {
 780           if (strcmp (*arch, chosen) < 0)
 781             chosen = *arch;
 782         }
 783       if (chosen == NULL)
 784         internal_error (__FILE__, __LINE__,
 785                         "initialize_current_architecture: No arch");
 786       info.bfd_arch_info = bfd_scan_arch (chosen);
 787       if (info.bfd_arch_info == NULL)
 788         internal_error (__FILE__, __LINE__,
 789                         "initialize_current_architecture: Arch not found");
 790     }
 791
 792   /* Take several guesses at a byte order.  */
 793   if (info.byte_order == BFD_ENDIAN_UNKNOWN
 794       && default_bfd_vec != NULL)
 795     {
 796       /* Extract BFD's default vector's byte order. */
 797       switch (default_bfd_vec->byteorder)
 798         {
 799         case BFD_ENDIAN_BIG:
 800           info.byte_order = BFD_ENDIAN_BIG;
 801           break;
 802         case BFD_ENDIAN_LITTLE:
 803           info.byte_order = BFD_ENDIAN_LITTLE;
 804           break;
 805         default:
 806           break;
 807         }
 808     }
 809   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 810     {
 811       /* look for ``*el-*'' in the target name. */
 812       const char *chp;
 813       chp = strchr (target_name, '-');
 814       if (chp != NULL
 815           && chp - 2 >= target_name
 816           && strncmp (chp - 2, "el", 2) == 0)
 817         info.byte_order = BFD_ENDIAN_LITTLE;
 818     }
 819   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 820     {
 821       /* Wire it to big-endian!!! */
 822       info.byte_order = BFD_ENDIAN_BIG;
 823     }
 824
 825   if (GDB_MULTI_ARCH)
 826     {
 827       if (! gdbarch_update_p (info))
 828         {
 829           internal_error (__FILE__, __LINE__,
 830                           "initialize_current_architecture: Selection of initial architecture failed");
 831         }
 832     }
 833   else
 834     {
 835       /* If the multi-arch logic comes up with a byte-order (from BFD)
 836          use it for the non-multi-arch case.  */
 837       if (info.byte_order != BFD_ENDIAN_UNKNOWN)
 838         target_byte_order = info.byte_order;
 839       initialize_non_multiarch ();
 840     }
 841
 842   /* Create the ``set architecture'' command appending ``auto'' to the
 843      list of architectures. */
 844   {
 845     struct cmd_list_element *c;
 846     /* Append ``auto''. */
 847     int nr;
 848     for (nr = 0; arches[nr] != NULL; nr++);
 849     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 850     arches[nr + 0] = "auto";
 851     arches[nr + 1] = NULL;
 852     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 853        of ``const char *''.  We just happen to know that the casts are
 854        safe. */
 855     c = add_set_enum_cmd ("architecture", class_support,
 856                           arches, &set_architecture_string,
 857                           "Set architecture of target.",
 858                           &setlist);
 859     set_cmd_sfunc (c, set_architecture);
 860     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 861     /* Don't use set_from_show - need to print both auto/manual and
 862        current setting. */
 863     add_cmd ("architecture", class_support, show_architecture,
 864              "Show the current target architecture", &showlist);
 865   }
 866 }
 867
 868
 869 /* Initialize a gdbarch info to values that will be automatically
 870    overridden.  Note: Originally, this ``struct info'' was initialized
 871    using memset(0).  Unfortunatly, that ran into problems, namely
 872    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 873    can explicitly set each field to a well defined value is used.  */
 874
 875 void
 876 gdbarch_info_init (struct gdbarch_info *info)
 877 {
 878   memset (info, 0, sizeof (struct gdbarch_info));
 879   info->byte_order = BFD_ENDIAN_UNKNOWN;
 880 }
 881
 882 /* */
 883
 884 extern initialize_file_ftype _initialize_gdbarch_utils;
 885
 886 void
 887 _initialize_gdbarch_utils (void)
 888 {
 889   struct cmd_list_element *c;
 890   c = add_set_enum_cmd ("endian", class_support,
 891                         endian_enum, &set_endian_string,
 892                         "Set endianness of target.",
 893                         &setlist);
 894   set_cmd_sfunc (c, set_endian);
 895   /* Don't use set_from_show - need to print both auto/manual and
 896      current setting. */
 897   add_cmd ("endian", class_support, show_endian,
 898            "Show the current byte-order", &showlist);
 899 }