gdb/arch-utils.c

   1 /* Dynamic architecture support for GDB, the GNU debugger.
   2
   3    Copyright 1998, 1999, 2000, 2001, 2002, 2003 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 #include "arch-utils.h"
  26 #include "buildsym.h"
  27 #include "gdbcmd.h"
  28 #include "inferior.h"           /* enum CALL_DUMMY_LOCATION et.al. */
  29 #include "gdb_string.h"
  30 #include "regcache.h"
  31 #include "gdb_assert.h"
  32 #include "sim-regno.h"
  33
  34 #include "osabi.h"
  35
  36 #include "version.h"
  37
  38 #include "floatformat.h"
  39
  40 /* Implementation of extract return value that grubs around in the
  41    register cache.  */
  42 void
  43 legacy_extract_return_value (struct type *type, struct regcache *regcache,
  44                              void *valbuf)
  45 {
  46   char *registers = deprecated_grub_regcache_for_registers (regcache);
  47   bfd_byte *buf = valbuf;
  48   DEPRECATED_EXTRACT_RETURN_VALUE (type, registers, buf); /* OK */
  49 }
  50
  51 /* Implementation of store return value that grubs the register cache.
  52    Takes a local copy of the buffer to avoid const problems.  */
  53 void
  54 legacy_store_return_value (struct type *type, struct regcache *regcache,
  55                            const void *buf)
  56 {
  57   bfd_byte *b = alloca (TYPE_LENGTH (type));
  58   gdb_assert (regcache == current_regcache);
  59   memcpy (b, buf, TYPE_LENGTH (type));
  60   DEPRECATED_STORE_RETURN_VALUE (type, b);
  61 }
  62
  63
  64 int
  65 always_use_struct_convention (int gcc_p, struct type *value_type)
  66 {
  67   return 1;
  68 }
  69
  70
  71 int
  72 legacy_register_sim_regno (int regnum)
  73 {
  74   /* Only makes sense to supply raw registers.  */
  75   gdb_assert (regnum >= 0 && regnum < NUM_REGS);
  76   /* NOTE: cagney/2002-05-13: The old code did it this way and it is
  77      suspected that some GDB/SIM combinations may rely on this
  78      behavour.  The default should be one2one_register_sim_regno
  79      (below).  */
  80   if (REGISTER_NAME (regnum) != NULL
  81       && REGISTER_NAME (regnum)[0] != '\0')
  82     return regnum;
  83   else
  84     return LEGACY_SIM_REGNO_IGNORE;
  85 }
  86
  87 int
  88 generic_frameless_function_invocation_not (struct frame_info *fi)
  89 {
  90   return 0;
  91 }
  92
  93 int
  94 generic_return_value_on_stack_not (struct type *type)
  95 {
  96   return 0;
  97 }
  98
  99 CORE_ADDR
 100 generic_skip_trampoline_code (CORE_ADDR pc)
 101 {
 102   return 0;
 103 }
 104
 105 CORE_ADDR
 106 generic_skip_solib_resolver (struct gdbarch *gdbarch, 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_solib_return_trampoline (CORE_ADDR pc, char *name)
 119 {
 120   return 0;
 121 }
 122
 123 int
 124 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 125 {
 126   return 0;
 127 }
 128
 129 #if defined (CALL_DUMMY)
 130 LONGEST legacy_call_dummy_words[] = CALL_DUMMY;
 131 #else
 132 LONGEST legacy_call_dummy_words[1];
 133 #endif
 134 int legacy_sizeof_call_dummy_words = sizeof (legacy_call_dummy_words);
 135
 136 void
 137 generic_remote_translate_xfer_address (struct gdbarch *gdbarch,
 138                                        struct regcache *regcache,
 139                                        CORE_ADDR gdb_addr, int gdb_len,
 140                                        CORE_ADDR * rem_addr, int *rem_len)
 141 {
 142   *rem_addr = gdb_addr;
 143   *rem_len = gdb_len;
 144 }
 145
 146 /* Helper functions for INNER_THAN */
 147
 148 int
 149 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 150 {
 151   return (lhs < rhs);
 152 }
 153
 154 int
 155 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 156 {
 157   return (lhs > rhs);
 158 }
 159
 160
 161 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 162
 163 const struct floatformat *
 164 default_float_format (struct gdbarch *gdbarch)
 165 {
 166   int byte_order = gdbarch_byte_order (gdbarch);
 167   switch (byte_order)
 168     {
 169     case BFD_ENDIAN_BIG:
 170       return &floatformat_ieee_single_big;
 171     case BFD_ENDIAN_LITTLE:
 172       return &floatformat_ieee_single_little;
 173     default:
 174       internal_error (__FILE__, __LINE__,
 175                       "default_float_format: bad byte order");
 176     }
 177 }
 178
 179
 180 const struct floatformat *
 181 default_double_format (struct gdbarch *gdbarch)
 182 {
 183   int byte_order = gdbarch_byte_order (gdbarch);
 184   switch (byte_order)
 185     {
 186     case BFD_ENDIAN_BIG:
 187       return &floatformat_ieee_double_big;
 188     case BFD_ENDIAN_LITTLE:
 189       return &floatformat_ieee_double_little;
 190     default:
 191       internal_error (__FILE__, __LINE__,
 192                       "default_double_format: bad byte order");
 193     }
 194 }
 195
 196 /* Misc helper functions for targets. */
 197
 198 int
 199 deprecated_register_convertible_not (int num)
 200 {
 201   return 0;
 202 }
 203
 204
 205 CORE_ADDR
 206 core_addr_identity (CORE_ADDR addr)
 207 {
 208   return addr;
 209 }
 210
 211 CORE_ADDR
 212 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
 213                                      struct target_ops *targ)
 214 {
 215   return addr;
 216 }
 217
 218 int
 219 no_op_reg_to_regnum (int reg)
 220 {
 221   return reg;
 222 }
 223
 224 CORE_ADDR
 225 deprecated_init_frame_pc_default (int fromleaf, struct frame_info *prev)
 226 {
 227   if (fromleaf && DEPRECATED_SAVED_PC_AFTER_CALL_P ())
 228     return DEPRECATED_SAVED_PC_AFTER_CALL (get_next_frame (prev));
 229   else if (get_next_frame (prev) != NULL)
 230     return DEPRECATED_FRAME_SAVED_PC (get_next_frame (prev));
 231   else
 232     return read_pc ();
 233 }
 234
 235 void
 236 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 237 {
 238   return;
 239 }
 240
 241 void
 242 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 243 {
 244   return;
 245 }
 246
 247 int
 248 cannot_register_not (int regnum)
 249 {
 250   return 0;
 251 }
 252
 253 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 254    there is an DEPRECATED_FP_REGNUM and that it is the same, cooked or
 255    raw.  */
 256
 257 void
 258 legacy_virtual_frame_pointer (CORE_ADDR pc,
 259                               int *frame_regnum,
 260                               LONGEST *frame_offset)
 261 {
 262   /* FIXME: cagney/2002-09-13: This code is used when identifying the
 263      frame pointer of the current PC.  It is assuming that a single
 264      register and an offset can determine this.  I think it should
 265      instead generate a byte code expression as that would work better
 266      with things like Dwarf2's CFI.  */
 267   if (DEPRECATED_FP_REGNUM >= 0 && DEPRECATED_FP_REGNUM < NUM_REGS)
 268     *frame_regnum = DEPRECATED_FP_REGNUM;
 269   else if (SP_REGNUM >= 0 && SP_REGNUM < NUM_REGS)
 270     *frame_regnum = SP_REGNUM;
 271   else
 272     /* Should this be an internal error?  I guess so, it is reflecting
 273        an architectural limitation in the current design.  */
 274     internal_error (__FILE__, __LINE__, "No virtual frame pointer available");
 275   *frame_offset = 0;
 276 }
 277
 278 /* Assume the world is sane, every register's virtual and real size
 279    is identical.  */
 280
 281 int
 282 generic_register_size (int regnum)
 283 {
 284   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 285   if (gdbarch_register_type_p (current_gdbarch))
 286     return TYPE_LENGTH (gdbarch_register_type (current_gdbarch, regnum));
 287   else
 288     /* FIXME: cagney/2003-03-01: Once all architectures implement
 289        gdbarch_register_type(), this entire function can go away.  It
 290        is made obsolete by register_size().  */
 291     return TYPE_LENGTH (DEPRECATED_REGISTER_VIRTUAL_TYPE (regnum)); /* OK */
 292 }
 293
 294 /* Assume all registers are adjacent.  */
 295
 296 int
 297 generic_register_byte (int regnum)
 298 {
 299   int byte;
 300   int i;
 301   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 302   byte = 0;
 303   for (i = 0; i < regnum; i++)
 304     {
 305       byte += generic_register_size (i);
 306     }
 307   return byte;
 308 }
 309
 310 \f
 311 int
 312 legacy_pc_in_sigtramp (CORE_ADDR pc, char *name)
 313 {
 314 #if !defined (IN_SIGTRAMP)
 315   if (SIGTRAMP_START_P ())
 316     return (pc) >= SIGTRAMP_START (pc) && (pc) < SIGTRAMP_END (pc);
 317   else
 318     return name && strcmp ("_sigtramp", name) == 0;
 319 #else
 320   return IN_SIGTRAMP (pc, name);
 321 #endif
 322 }
 323
 324 int
 325 legacy_convert_register_p (int regnum, struct type *type)
 326 {
 327   return DEPRECATED_REGISTER_CONVERTIBLE (regnum);
 328 }
 329
 330 void
 331 legacy_register_to_value (struct frame_info *frame, int regnum,
 332                           struct type *type, void *to)
 333 {
 334   char from[MAX_REGISTER_SIZE];
 335   get_frame_register (frame, regnum, from);
 336   DEPRECATED_REGISTER_CONVERT_TO_VIRTUAL (regnum, type, from, to);
 337 }
 338
 339 void
 340 legacy_value_to_register (struct frame_info *frame, int regnum,
 341                           struct type *type, const void *tmp)
 342 {
 343   char to[MAX_REGISTER_SIZE];
 344   char *from = alloca (TYPE_LENGTH (type));
 345   memcpy (from, from, TYPE_LENGTH (type));
 346   DEPRECATED_REGISTER_CONVERT_TO_RAW (type, regnum, from, to);
 347   put_frame_register (frame, regnum, to);
 348 }
 349
 350 int
 351 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
 352 {
 353   if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ()
 354       && DEPRECATED_REG_STRUCT_HAS_ADDR (processing_gcc_compilation, type))
 355     {
 356       CHECK_TYPEDEF (type);
 357
 358       return (TYPE_CODE (type) == TYPE_CODE_STRUCT
 359               || TYPE_CODE (type) == TYPE_CODE_UNION
 360               || TYPE_CODE (type) == TYPE_CODE_SET
 361               || TYPE_CODE (type) == TYPE_CODE_BITSTRING);
 362     }
 363
 364   return 0;
 365 }
 366
 367 \f
 368 /* Functions to manipulate the endianness of the target.  */
 369
 370 /* ``target_byte_order'' is only used when non- multi-arch.
 371    Multi-arch targets obtain the current byte order using the
 372    TARGET_BYTE_ORDER gdbarch method.
 373
 374    The choice of initial value is entirely arbitrary.  During startup,
 375    the function initialize_current_architecture() updates this value
 376    based on default byte-order information extracted from BFD.  */
 377 static int target_byte_order = BFD_ENDIAN_BIG;
 378 static int target_byte_order_auto = 1;
 379
 380 enum bfd_endian
 381 selected_byte_order (void)
 382 {
 383   if (target_byte_order_auto)
 384     return BFD_ENDIAN_UNKNOWN;
 385   else
 386     return target_byte_order;
 387 }
 388
 389 static const char endian_big[] = "big";
 390 static const char endian_little[] = "little";
 391 static const char endian_auto[] = "auto";
 392 static const char *endian_enum[] =
 393 {
 394   endian_big,
 395   endian_little,
 396   endian_auto,
 397   NULL,
 398 };
 399 static const char *set_endian_string;
 400
 401 /* Called by ``show endian''.  */
 402
 403 static void
 404 show_endian (char *args, int from_tty)
 405 {
 406   if (target_byte_order_auto)
 407     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 408                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 409   else
 410     printf_unfiltered ("The target is assumed to be %s endian\n",
 411                        (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG ? "big" : "little"));
 412 }
 413
 414 static void
 415 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 416 {
 417   if (set_endian_string == endian_auto)
 418     {
 419       target_byte_order_auto = 1;
 420     }
 421   else if (set_endian_string == endian_little)
 422     {
 423       struct gdbarch_info info;
 424       target_byte_order_auto = 0;
 425       gdbarch_info_init (&info);
 426       info.byte_order = BFD_ENDIAN_LITTLE;
 427       if (! gdbarch_update_p (info))
 428         printf_unfiltered ("Little endian target not supported by GDB\n");
 429     }
 430   else if (set_endian_string == endian_big)
 431     {
 432       struct gdbarch_info info;
 433       target_byte_order_auto = 0;
 434       gdbarch_info_init (&info);
 435       info.byte_order = BFD_ENDIAN_BIG;
 436       if (! gdbarch_update_p (info))
 437         printf_unfiltered ("Big endian target not supported by GDB\n");
 438     }
 439   else
 440     internal_error (__FILE__, __LINE__,
 441                     "set_endian: bad value");
 442   show_endian (NULL, from_tty);
 443 }
 444
 445 /* Functions to manipulate the architecture of the target */
 446
 447 enum set_arch { set_arch_auto, set_arch_manual };
 448
 449 static int target_architecture_auto = 1;
 450
 451 static const char *set_architecture_string;
 452
 453 const char *
 454 selected_architecture_name (void)
 455 {
 456   if (target_architecture_auto)
 457     return NULL;
 458   else
 459     return set_architecture_string;
 460 }
 461
 462 /* Called if the user enters ``show architecture'' without an
 463    argument. */
 464
 465 static void
 466 show_architecture (char *args, int from_tty)
 467 {
 468   const char *arch;
 469   arch = TARGET_ARCHITECTURE->printable_name;
 470   if (target_architecture_auto)
 471     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 472   else
 473     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 474 }
 475
 476
 477 /* Called if the user enters ``set architecture'' with or without an
 478    argument. */
 479
 480 static void
 481 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 482 {
 483   if (strcmp (set_architecture_string, "auto") == 0)
 484     {
 485       target_architecture_auto = 1;
 486     }
 487   else
 488     {
 489       struct gdbarch_info info;
 490       gdbarch_info_init (&info);
 491       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 492       if (info.bfd_arch_info == NULL)
 493         internal_error (__FILE__, __LINE__,
 494                         "set_architecture: bfd_scan_arch failed");
 495       if (gdbarch_update_p (info))
 496         target_architecture_auto = 0;
 497       else
 498         printf_unfiltered ("Architecture `%s' not recognized.\n",
 499                            set_architecture_string);
 500     }
 501   show_architecture (NULL, from_tty);
 502 }
 503
 504 /* Try to select a global architecture that matches "info".  Return
 505    non-zero if the attempt succeds.  */
 506 int
 507 gdbarch_update_p (struct gdbarch_info info)
 508 {
 509   struct gdbarch *new_gdbarch = gdbarch_find_by_info (info);
 510
 511   /* If there no architecture by that name, reject the request.  */
 512   if (new_gdbarch == NULL)
 513     {
 514       if (gdbarch_debug)
 515         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 516                             "Architecture not found\n");
 517       return 0;
 518     }
 519
 520   /* If it is the same old architecture, accept the request (but don't
 521      swap anything).  */
 522   if (new_gdbarch == current_gdbarch)
 523     {
 524       if (gdbarch_debug)
 525         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 526                             "Architecture 0x%08lx (%s) unchanged\n",
 527                             (long) new_gdbarch,
 528                             gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 529       return 1;
 530     }
 531
 532   /* It's a new architecture, swap it in.  */
 533   if (gdbarch_debug)
 534     fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 535                         "New architecture 0x%08lx (%s) selected\n",
 536                         (long) new_gdbarch,
 537                         gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 538   deprecated_current_gdbarch_select_hack (new_gdbarch);
 539
 540   return 1;
 541 }
 542
 543 /* Return the architecture for ABFD.  If no suitable architecture
 544    could be find, return NULL.  */
 545
 546 struct gdbarch *
 547 gdbarch_from_bfd (bfd *abfd)
 548 {
 549   struct gdbarch *old_gdbarch = current_gdbarch;
 550   struct gdbarch *new_gdbarch;
 551   struct gdbarch_info info;
 552
 553   gdbarch_info_init (&info);
 554   info.abfd = abfd;
 555   return gdbarch_find_by_info (info);
 556 }
 557
 558 /* Set the dynamic target-system-dependent parameters (architecture,
 559    byte-order) using information found in the BFD */
 560
 561 void
 562 set_gdbarch_from_file (bfd *abfd)
 563 {
 564   struct gdbarch *gdbarch;
 565
 566   gdbarch = gdbarch_from_bfd (abfd);
 567   if (gdbarch == NULL)
 568     error ("Architecture of file not recognized.\n");
 569   deprecated_current_gdbarch_select_hack (gdbarch);
 570 }
 571
 572 /* Initialize the current architecture.  Update the ``set
 573    architecture'' command so that it specifies a list of valid
 574    architectures.  */
 575
 576 #ifdef DEFAULT_BFD_ARCH
 577 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 578 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 579 #else
 580 static const bfd_arch_info_type *default_bfd_arch;
 581 #endif
 582
 583 #ifdef DEFAULT_BFD_VEC
 584 extern const bfd_target DEFAULT_BFD_VEC;
 585 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 586 #else
 587 static const bfd_target *default_bfd_vec;
 588 #endif
 589
 590 void
 591 initialize_current_architecture (void)
 592 {
 593   const char **arches = gdbarch_printable_names ();
 594
 595   /* determine a default architecture and byte order. */
 596   struct gdbarch_info info;
 597   gdbarch_info_init (&info);
 598
 599   /* Find a default architecture. */
 600   if (info.bfd_arch_info == NULL
 601       && default_bfd_arch != NULL)
 602     info.bfd_arch_info = default_bfd_arch;
 603   if (info.bfd_arch_info == NULL)
 604     {
 605       /* Choose the architecture by taking the first one
 606          alphabetically. */
 607       const char *chosen = arches[0];
 608       const char **arch;
 609       for (arch = arches; *arch != NULL; arch++)
 610         {
 611           if (strcmp (*arch, chosen) < 0)
 612             chosen = *arch;
 613         }
 614       if (chosen == NULL)
 615         internal_error (__FILE__, __LINE__,
 616                         "initialize_current_architecture: No arch");
 617       info.bfd_arch_info = bfd_scan_arch (chosen);
 618       if (info.bfd_arch_info == NULL)
 619         internal_error (__FILE__, __LINE__,
 620                         "initialize_current_architecture: Arch not found");
 621     }
 622
 623   /* Take several guesses at a byte order.  */
 624   if (info.byte_order == BFD_ENDIAN_UNKNOWN
 625       && default_bfd_vec != NULL)
 626     {
 627       /* Extract BFD's default vector's byte order. */
 628       switch (default_bfd_vec->byteorder)
 629         {
 630         case BFD_ENDIAN_BIG:
 631           info.byte_order = BFD_ENDIAN_BIG;
 632           break;
 633         case BFD_ENDIAN_LITTLE:
 634           info.byte_order = BFD_ENDIAN_LITTLE;
 635           break;
 636         default:
 637           break;
 638         }
 639     }
 640   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 641     {
 642       /* look for ``*el-*'' in the target name. */
 643       const char *chp;
 644       chp = strchr (target_name, '-');
 645       if (chp != NULL
 646           && chp - 2 >= target_name
 647           && strncmp (chp - 2, "el", 2) == 0)
 648         info.byte_order = BFD_ENDIAN_LITTLE;
 649     }
 650   if (info.byte_order == BFD_ENDIAN_UNKNOWN)
 651     {
 652       /* Wire it to big-endian!!! */
 653       info.byte_order = BFD_ENDIAN_BIG;
 654     }
 655
 656   if (! gdbarch_update_p (info))
 657     internal_error (__FILE__, __LINE__,
 658                     "initialize_current_architecture: Selection of initial architecture failed");
 659
 660   /* Create the ``set architecture'' command appending ``auto'' to the
 661      list of architectures. */
 662   {
 663     struct cmd_list_element *c;
 664     /* Append ``auto''. */
 665     int nr;
 666     for (nr = 0; arches[nr] != NULL; nr++);
 667     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 668     arches[nr + 0] = "auto";
 669     arches[nr + 1] = NULL;
 670     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 671        of ``const char *''.  We just happen to know that the casts are
 672        safe. */
 673     c = add_set_enum_cmd ("architecture", class_support,
 674                           arches, &set_architecture_string,
 675                           "Set architecture of target.",
 676                           &setlist);
 677     set_cmd_sfunc (c, set_architecture);
 678     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 679     /* Don't use set_from_show - need to print both auto/manual and
 680        current setting. */
 681     add_cmd ("architecture", class_support, show_architecture,
 682              "Show the current target architecture", &showlist);
 683   }
 684 }
 685
 686
 687 /* Initialize a gdbarch info to values that will be automatically
 688    overridden.  Note: Originally, this ``struct info'' was initialized
 689    using memset(0).  Unfortunately, that ran into problems, namely
 690    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 691    can explicitly set each field to a well defined value is used.  */
 692
 693 void
 694 gdbarch_info_init (struct gdbarch_info *info)
 695 {
 696   memset (info, 0, sizeof (struct gdbarch_info));
 697   info->byte_order = BFD_ENDIAN_UNKNOWN;
 698   info->osabi = GDB_OSABI_UNINITIALIZED;
 699 }
 700
 701 /* Similar to init, but this time fill in the blanks.  Information is
 702    obtained from the specified architecture, global "set ..." options,
 703    and explicitly initialized INFO fields.  */
 704
 705 void
 706 gdbarch_info_fill (struct gdbarch *gdbarch, struct gdbarch_info *info)
 707 {
 708   /* "(gdb) set architecture ...".  */
 709   if (info->bfd_arch_info == NULL
 710       && !target_architecture_auto
 711       && gdbarch != NULL)
 712     info->bfd_arch_info = gdbarch_bfd_arch_info (gdbarch);
 713   if (info->bfd_arch_info == NULL
 714       && info->abfd != NULL
 715       && bfd_get_arch (info->abfd) != bfd_arch_unknown
 716       && bfd_get_arch (info->abfd) != bfd_arch_obscure)
 717     info->bfd_arch_info = bfd_get_arch_info (info->abfd);
 718   if (info->bfd_arch_info == NULL
 719       && gdbarch != NULL)
 720     info->bfd_arch_info = gdbarch_bfd_arch_info (gdbarch);
 721
 722   /* "(gdb) set byte-order ...".  */
 723   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 724       && !target_byte_order_auto
 725       && gdbarch != NULL)
 726     info->byte_order = gdbarch_byte_order (gdbarch);
 727   /* From the INFO struct.  */
 728   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 729       && info->abfd != NULL)
 730     info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
 731                        : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
 732                        : BFD_ENDIAN_UNKNOWN);
 733   /* From the current target.  */
 734   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 735       && gdbarch != NULL)
 736     info->byte_order = gdbarch_byte_order (gdbarch);
 737
 738   /* "(gdb) set osabi ...".  Handled by gdbarch_lookup_osabi.  */
 739   if (info->osabi == GDB_OSABI_UNINITIALIZED)
 740     info->osabi = gdbarch_lookup_osabi (info->abfd);
 741   if (info->osabi == GDB_OSABI_UNINITIALIZED
 742       && gdbarch != NULL)
 743     info->osabi = gdbarch_osabi (gdbarch);
 744
 745   /* Must have at least filled in the architecture.  */
 746   gdb_assert (info->bfd_arch_info != NULL);
 747 }
 748
 749 /* */
 750
 751 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
 752
 753 void
 754 _initialize_gdbarch_utils (void)
 755 {
 756   struct cmd_list_element *c;
 757   c = add_set_enum_cmd ("endian", class_support,
 758                         endian_enum, &set_endian_string,
 759                         "Set endianness of target.",
 760                         &setlist);
 761   set_cmd_sfunc (c, set_endian);
 762   /* Don't use set_from_show - need to print both auto/manual and
 763      current setting. */
 764   add_cmd ("endian", class_support, show_endian,
 765            "Show the current byte-order", &showlist);
 766 }