gdb/arch-utils.c

   1 /* Dynamic architecture support for GDB, the GNU debugger.
   2
   3    Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
   4    Free Software Foundation, 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., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, 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 #include "gdbcore.h"
  34 #include "osabi.h"
  35 #include "target-descriptions.h"
  36
  37 #include "version.h"
  38
  39 #include "floatformat.h"
  40
  41 int
  42 always_use_struct_convention (int gcc_p, struct type *value_type)
  43 {
  44   return 1;
  45 }
  46
  47 enum return_value_convention
  48 legacy_return_value (struct gdbarch *gdbarch, struct type *valtype,
  49                      struct regcache *regcache, gdb_byte *readbuf,
  50                      const gdb_byte *writebuf)
  51 {
  52   /* NOTE: cagney/2004-06-13: The gcc_p parameter to
  53      USE_STRUCT_CONVENTION isn't used.  */
  54   int struct_return = ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  55                         || TYPE_CODE (valtype) == TYPE_CODE_UNION
  56                         || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
  57                        && DEPRECATED_USE_STRUCT_CONVENTION (0, valtype));
  58
  59   if (writebuf != NULL)
  60     {
  61       gdb_assert (!struct_return);
  62       /* NOTE: cagney/2004-06-13: See stack.c:return_command.  Old
  63          architectures don't expect STORE_RETURN_VALUE to handle small
  64          structures.  Should not be called with such types.  */
  65       gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_STRUCT
  66                   && TYPE_CODE (valtype) != TYPE_CODE_UNION);
  67       STORE_RETURN_VALUE (valtype, regcache, writebuf);
  68     }
  69
  70   if (readbuf != NULL)
  71     {
  72       gdb_assert (!struct_return);
  73       EXTRACT_RETURN_VALUE (valtype, regcache, readbuf);
  74     }
  75
  76   if (struct_return)
  77     return RETURN_VALUE_STRUCT_CONVENTION;
  78   else
  79     return RETURN_VALUE_REGISTER_CONVENTION;
  80 }
  81
  82 int
  83 legacy_register_sim_regno (int regnum)
  84 {
  85   /* Only makes sense to supply raw registers.  */
  86   gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (current_gdbarch));
  87   /* NOTE: cagney/2002-05-13: The old code did it this way and it is
  88      suspected that some GDB/SIM combinations may rely on this
  89      behavour.  The default should be one2one_register_sim_regno
  90      (below).  */
  91   if (gdbarch_register_name (current_gdbarch, regnum) != NULL
  92       && gdbarch_register_name (current_gdbarch, regnum)[0] != '\0')
  93     return regnum;
  94   else
  95     return LEGACY_SIM_REGNO_IGNORE;
  96 }
  97
  98 CORE_ADDR
  99 generic_skip_trampoline_code (CORE_ADDR pc)
 100 {
 101   return 0;
 102 }
 103
 104 CORE_ADDR
 105 generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
 106 {
 107   return 0;
 108 }
 109
 110 int
 111 generic_in_solib_return_trampoline (CORE_ADDR pc, char *name)
 112 {
 113   return 0;
 114 }
 115
 116 int
 117 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 118 {
 119   return 0;
 120 }
 121
 122 /* Helper functions for gdbarch_inner_than */
 123
 124 int
 125 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 126 {
 127   return (lhs < rhs);
 128 }
 129
 130 int
 131 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 132 {
 133   return (lhs > rhs);
 134 }
 135
 136 /* Misc helper functions for targets. */
 137
 138 CORE_ADDR
 139 core_addr_identity (CORE_ADDR addr)
 140 {
 141   return addr;
 142 }
 143
 144 CORE_ADDR
 145 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
 146                                      struct target_ops *targ)
 147 {
 148   return addr;
 149 }
 150
 151 int
 152 no_op_reg_to_regnum (int reg)
 153 {
 154   return reg;
 155 }
 156
 157 void
 158 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 159 {
 160   return;
 161 }
 162
 163 void
 164 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 165 {
 166   return;
 167 }
 168
 169 int
 170 cannot_register_not (int regnum)
 171 {
 172   return 0;
 173 }
 174
 175 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 176    there is an DEPRECATED_FP_REGNUM and that it is the same, cooked or
 177    raw.  */
 178
 179 void
 180 legacy_virtual_frame_pointer (CORE_ADDR pc,
 181                               int *frame_regnum,
 182                               LONGEST *frame_offset)
 183 {
 184   /* FIXME: cagney/2002-09-13: This code is used when identifying the
 185      frame pointer of the current PC.  It is assuming that a single
 186      register and an offset can determine this.  I think it should
 187      instead generate a byte code expression as that would work better
 188      with things like Dwarf2's CFI.  */
 189   if (DEPRECATED_FP_REGNUM >= 0
 190       && DEPRECATED_FP_REGNUM < gdbarch_num_regs (current_gdbarch))
 191     *frame_regnum = DEPRECATED_FP_REGNUM;
 192   else if (SP_REGNUM >= 0 && SP_REGNUM < gdbarch_num_regs (current_gdbarch))
 193     *frame_regnum = SP_REGNUM;
 194   else
 195     /* Should this be an internal error?  I guess so, it is reflecting
 196        an architectural limitation in the current design.  */
 197     internal_error (__FILE__, __LINE__, _("No virtual frame pointer available"));
 198   *frame_offset = 0;
 199 }
 200
 201 \f
 202 int
 203 generic_convert_register_p (int regnum, struct type *type)
 204 {
 205   return 0;
 206 }
 207
 208 int
 209 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
 210 {
 211   return 0;
 212 }
 213
 214 int
 215 generic_instruction_nullified (struct gdbarch *gdbarch,
 216                                struct regcache *regcache)
 217 {
 218   return 0;
 219 }
 220
 221 int
 222 default_remote_register_number (struct gdbarch *gdbarch,
 223                                 int regno)
 224 {
 225   return regno;
 226 }
 227
 228 \f
 229 /* Functions to manipulate the endianness of the target.  */
 230
 231 static int target_byte_order_user = BFD_ENDIAN_UNKNOWN;
 232
 233 static const char endian_big[] = "big";
 234 static const char endian_little[] = "little";
 235 static const char endian_auto[] = "auto";
 236 static const char *endian_enum[] =
 237 {
 238   endian_big,
 239   endian_little,
 240   endian_auto,
 241   NULL,
 242 };
 243 static const char *set_endian_string;
 244
 245 enum bfd_endian
 246 selected_byte_order (void)
 247 {
 248   if (target_byte_order_user != BFD_ENDIAN_UNKNOWN)
 249     return gdbarch_byte_order (current_gdbarch);
 250   else
 251     return BFD_ENDIAN_UNKNOWN;
 252 }
 253
 254 /* Called by ``show endian''.  */
 255
 256 static void
 257 show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c,
 258              const char *value)
 259 {
 260   if (target_byte_order_user == BFD_ENDIAN_UNKNOWN)
 261     if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
 262       fprintf_unfiltered (file, _("The target endianness is set automatically "
 263                                   "(currently big endian)\n"));
 264     else
 265       fprintf_unfiltered (file, _("The target endianness is set automatically "
 266                            "(currently little endian)\n"));
 267   else
 268     if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
 269       fprintf_unfiltered (file,
 270                           _("The target is assumed to be big endian\n"));
 271     else
 272       fprintf_unfiltered (file,
 273                           _("The target is assumed to be little endian\n"));
 274 }
 275
 276 static void
 277 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 278 {
 279   struct gdbarch_info info;
 280
 281   gdbarch_info_init (&info);
 282
 283   if (set_endian_string == endian_auto)
 284     {
 285       target_byte_order_user = BFD_ENDIAN_UNKNOWN;
 286       if (! gdbarch_update_p (info))
 287         internal_error (__FILE__, __LINE__,
 288                         _("set_endian: architecture update failed"));
 289     }
 290   else if (set_endian_string == endian_little)
 291     {
 292       info.byte_order = BFD_ENDIAN_LITTLE;
 293       if (! gdbarch_update_p (info))
 294         printf_unfiltered (_("Little endian target not supported by GDB\n"));
 295       else
 296         target_byte_order_user = BFD_ENDIAN_LITTLE;
 297     }
 298   else if (set_endian_string == endian_big)
 299     {
 300       info.byte_order = BFD_ENDIAN_BIG;
 301       if (! gdbarch_update_p (info))
 302         printf_unfiltered (_("Big endian target not supported by GDB\n"));
 303       else
 304         target_byte_order_user = BFD_ENDIAN_BIG;
 305     }
 306   else
 307     internal_error (__FILE__, __LINE__,
 308                     _("set_endian: bad value"));
 309
 310   show_endian (gdb_stdout, from_tty, NULL, NULL);
 311 }
 312
 313 /* Given SELECTED, a currently selected BFD architecture, and
 314    FROM_TARGET, a BFD architecture reported by the target description,
 315    return what architecture to use.  Either may be NULL; if both are
 316    specified, we use the more specific.  If the two are obviously
 317    incompatible, warn the user.  */
 318
 319 static const struct bfd_arch_info *
 320 choose_architecture_for_target (const struct bfd_arch_info *selected,
 321                                 const struct bfd_arch_info *from_target)
 322 {
 323   const struct bfd_arch_info *compat1, *compat2;
 324
 325   if (selected == NULL)
 326     return from_target;
 327
 328   if (from_target == NULL)
 329     return selected;
 330
 331   /* struct bfd_arch_info objects are singletons: that is, there's
 332      supposed to be exactly one instance for a given machine.  So you
 333      can tell whether two are equivalent by comparing pointers.  */
 334   if (from_target == selected)
 335     return selected;
 336
 337   /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
 338      incompatible.  But if they are compatible, it returns the 'more
 339      featureful' of the two arches.  That is, if A can run code
 340      written for B, but B can't run code written for A, then it'll
 341      return A.
 342
 343      Some targets (e.g. MIPS as of 2006-12-04) don't fully
 344      implement this, instead always returning NULL or the first
 345      argument.  We detect that case by checking both directions.  */
 346
 347   compat1 = selected->compatible (selected, from_target);
 348   compat2 = from_target->compatible (from_target, selected);
 349
 350   if (compat1 == NULL && compat2 == NULL)
 351     {
 352       warning (_("Selected architecture %s is not compatible "
 353                  "with reported target architecture %s"),
 354                selected->printable_name, from_target->printable_name);
 355       return selected;
 356     }
 357
 358   if (compat1 == NULL)
 359     return compat2;
 360   if (compat2 == NULL)
 361     return compat1;
 362   if (compat1 == compat2)
 363     return compat1;
 364
 365   /* If the two didn't match, but one of them was a default architecture,
 366      assume the more specific one is correct.  This handles the case
 367      where an executable or target description just says "mips", but
 368      the other knows which MIPS variant.  */
 369   if (compat1->the_default)
 370     return compat2;
 371   if (compat2->the_default)
 372     return compat1;
 373
 374   /* We have no idea which one is better.  This is a bug, but not
 375      a critical problem; warn the user.  */
 376   warning (_("Selected architecture %s is ambiguous with "
 377              "reported target architecture %s"),
 378            selected->printable_name, from_target->printable_name);
 379   return selected;
 380 }
 381
 382 /* Functions to manipulate the architecture of the target */
 383
 384 enum set_arch { set_arch_auto, set_arch_manual };
 385
 386 static const struct bfd_arch_info *target_architecture_user;
 387
 388 static const char *set_architecture_string;
 389
 390 const char *
 391 selected_architecture_name (void)
 392 {
 393   if (target_architecture_user == NULL)
 394     return NULL;
 395   else
 396     return set_architecture_string;
 397 }
 398
 399 /* Called if the user enters ``show architecture'' without an
 400    argument. */
 401
 402 static void
 403 show_architecture (struct ui_file *file, int from_tty,
 404                    struct cmd_list_element *c, const char *value)
 405 {
 406   const char *arch;
 407   arch = gdbarch_bfd_arch_info (current_gdbarch)->printable_name;
 408   if (target_architecture_user == NULL)
 409     fprintf_filtered (file, _("\
 410 The target architecture is set automatically (currently %s)\n"), arch);
 411   else
 412     fprintf_filtered (file, _("\
 413 The target architecture is assumed to be %s\n"), arch);
 414 }
 415
 416
 417 /* Called if the user enters ``set architecture'' with or without an
 418    argument. */
 419
 420 static void
 421 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 422 {
 423   struct gdbarch_info info;
 424
 425   gdbarch_info_init (&info);
 426
 427   if (strcmp (set_architecture_string, "auto") == 0)
 428     {
 429       target_architecture_user = NULL;
 430       if (!gdbarch_update_p (info))
 431         internal_error (__FILE__, __LINE__,
 432                         _("could not select an architecture automatically"));
 433     }
 434   else
 435     {
 436       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 437       if (info.bfd_arch_info == NULL)
 438         internal_error (__FILE__, __LINE__,
 439                         _("set_architecture: bfd_scan_arch failed"));
 440       if (gdbarch_update_p (info))
 441         target_architecture_user = info.bfd_arch_info;
 442       else
 443         printf_unfiltered (_("Architecture `%s' not recognized.\n"),
 444                            set_architecture_string);
 445     }
 446   show_architecture (gdb_stdout, from_tty, NULL, NULL);
 447 }
 448
 449 /* Try to select a global architecture that matches "info".  Return
 450    non-zero if the attempt succeds.  */
 451 int
 452 gdbarch_update_p (struct gdbarch_info info)
 453 {
 454   struct gdbarch *new_gdbarch = gdbarch_find_by_info (info);
 455
 456   /* If there no architecture by that name, reject the request.  */
 457   if (new_gdbarch == NULL)
 458     {
 459       if (gdbarch_debug)
 460         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 461                             "Architecture not found\n");
 462       return 0;
 463     }
 464
 465   /* If it is the same old architecture, accept the request (but don't
 466      swap anything).  */
 467   if (new_gdbarch == current_gdbarch)
 468     {
 469       if (gdbarch_debug)
 470         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 471                             "Architecture 0x%08lx (%s) unchanged\n",
 472                             (long) new_gdbarch,
 473                             gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 474       return 1;
 475     }
 476
 477   /* It's a new architecture, swap it in.  */
 478   if (gdbarch_debug)
 479     fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 480                         "New architecture 0x%08lx (%s) selected\n",
 481                         (long) new_gdbarch,
 482                         gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 483   deprecated_current_gdbarch_select_hack (new_gdbarch);
 484
 485   return 1;
 486 }
 487
 488 /* Return the architecture for ABFD.  If no suitable architecture
 489    could be find, return NULL.  */
 490
 491 struct gdbarch *
 492 gdbarch_from_bfd (bfd *abfd)
 493 {
 494   struct gdbarch *old_gdbarch = current_gdbarch;
 495   struct gdbarch *new_gdbarch;
 496   struct gdbarch_info info;
 497
 498   /* If we call gdbarch_find_by_info without filling in info.abfd,
 499      then it will use the global exec_bfd.  That's fine if we don't
 500      have one of those either.  And that's the only time we should
 501      reach here with a NULL ABFD argument - when we are discarding
 502      the executable.  */
 503   gdb_assert (abfd != NULL || exec_bfd == NULL);
 504
 505   gdbarch_info_init (&info);
 506   info.abfd = abfd;
 507   return gdbarch_find_by_info (info);
 508 }
 509
 510 /* Set the dynamic target-system-dependent parameters (architecture,
 511    byte-order) using information found in the BFD */
 512
 513 void
 514 set_gdbarch_from_file (bfd *abfd)
 515 {
 516   struct gdbarch *gdbarch;
 517
 518   gdbarch = gdbarch_from_bfd (abfd);
 519   if (gdbarch == NULL)
 520     error (_("Architecture of file not recognized."));
 521   deprecated_current_gdbarch_select_hack (gdbarch);
 522 }
 523
 524 /* Initialize the current architecture.  Update the ``set
 525    architecture'' command so that it specifies a list of valid
 526    architectures.  */
 527
 528 #ifdef DEFAULT_BFD_ARCH
 529 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 530 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 531 #else
 532 static const bfd_arch_info_type *default_bfd_arch;
 533 #endif
 534
 535 #ifdef DEFAULT_BFD_VEC
 536 extern const bfd_target DEFAULT_BFD_VEC;
 537 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 538 #else
 539 static const bfd_target *default_bfd_vec;
 540 #endif
 541
 542 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
 543
 544 void
 545 initialize_current_architecture (void)
 546 {
 547   const char **arches = gdbarch_printable_names ();
 548
 549   /* determine a default architecture and byte order. */
 550   struct gdbarch_info info;
 551   gdbarch_info_init (&info);
 552
 553   /* Find a default architecture. */
 554   if (default_bfd_arch == NULL)
 555     {
 556       /* Choose the architecture by taking the first one
 557          alphabetically. */
 558       const char *chosen = arches[0];
 559       const char **arch;
 560       for (arch = arches; *arch != NULL; arch++)
 561         {
 562           if (strcmp (*arch, chosen) < 0)
 563             chosen = *arch;
 564         }
 565       if (chosen == NULL)
 566         internal_error (__FILE__, __LINE__,
 567                         _("initialize_current_architecture: No arch"));
 568       default_bfd_arch = bfd_scan_arch (chosen);
 569       if (default_bfd_arch == NULL)
 570         internal_error (__FILE__, __LINE__,
 571                         _("initialize_current_architecture: Arch not found"));
 572     }
 573
 574   info.bfd_arch_info = default_bfd_arch;
 575
 576   /* Take several guesses at a byte order.  */
 577   if (default_byte_order == BFD_ENDIAN_UNKNOWN
 578       && default_bfd_vec != NULL)
 579     {
 580       /* Extract BFD's default vector's byte order. */
 581       switch (default_bfd_vec->byteorder)
 582         {
 583         case BFD_ENDIAN_BIG:
 584           default_byte_order = BFD_ENDIAN_BIG;
 585           break;
 586         case BFD_ENDIAN_LITTLE:
 587           default_byte_order = BFD_ENDIAN_LITTLE;
 588           break;
 589         default:
 590           break;
 591         }
 592     }
 593   if (default_byte_order == BFD_ENDIAN_UNKNOWN)
 594     {
 595       /* look for ``*el-*'' in the target name. */
 596       const char *chp;
 597       chp = strchr (target_name, '-');
 598       if (chp != NULL
 599           && chp - 2 >= target_name
 600           && strncmp (chp - 2, "el", 2) == 0)
 601         default_byte_order = BFD_ENDIAN_LITTLE;
 602     }
 603   if (default_byte_order == BFD_ENDIAN_UNKNOWN)
 604     {
 605       /* Wire it to big-endian!!! */
 606       default_byte_order = BFD_ENDIAN_BIG;
 607     }
 608
 609   info.byte_order = default_byte_order;
 610
 611   if (! gdbarch_update_p (info))
 612     internal_error (__FILE__, __LINE__,
 613                     _("initialize_current_architecture: Selection of "
 614                       "initial architecture failed"));
 615
 616   /* Create the ``set architecture'' command appending ``auto'' to the
 617      list of architectures. */
 618   {
 619     struct cmd_list_element *c;
 620     /* Append ``auto''. */
 621     int nr;
 622     for (nr = 0; arches[nr] != NULL; nr++);
 623     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 624     arches[nr + 0] = "auto";
 625     arches[nr + 1] = NULL;
 626     add_setshow_enum_cmd ("architecture", class_support,
 627                           arches, &set_architecture_string, _("\
 628 Set architecture of target."), _("\
 629 Show architecture of target."), NULL,
 630                           set_architecture, show_architecture,
 631                           &setlist, &showlist);
 632     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 633   }
 634 }
 635
 636
 637 /* Initialize a gdbarch info to values that will be automatically
 638    overridden.  Note: Originally, this ``struct info'' was initialized
 639    using memset(0).  Unfortunately, that ran into problems, namely
 640    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 641    can explicitly set each field to a well defined value is used.  */
 642
 643 void
 644 gdbarch_info_init (struct gdbarch_info *info)
 645 {
 646   memset (info, 0, sizeof (struct gdbarch_info));
 647   info->byte_order = BFD_ENDIAN_UNKNOWN;
 648   info->osabi = GDB_OSABI_UNINITIALIZED;
 649 }
 650
 651 /* Similar to init, but this time fill in the blanks.  Information is
 652    obtained from the global "set ..." options and explicitly
 653    initialized INFO fields.  */
 654
 655 void
 656 gdbarch_info_fill (struct gdbarch_info *info)
 657 {
 658   /* Check for the current file.  */
 659   if (info->abfd == NULL)
 660     info->abfd = exec_bfd;
 661
 662   /* Check for the current target description.  */
 663   if (info->target_desc == NULL)
 664     info->target_desc = target_current_description ();
 665
 666   /* "(gdb) set architecture ...".  */
 667   if (info->bfd_arch_info == NULL
 668       && target_architecture_user)
 669     info->bfd_arch_info = target_architecture_user;
 670   /* From the file.  */
 671   if (info->bfd_arch_info == NULL
 672       && info->abfd != NULL
 673       && bfd_get_arch (info->abfd) != bfd_arch_unknown
 674       && bfd_get_arch (info->abfd) != bfd_arch_obscure)
 675     info->bfd_arch_info = bfd_get_arch_info (info->abfd);
 676   /* From the target.  */
 677   if (info->target_desc != NULL)
 678     info->bfd_arch_info = choose_architecture_for_target
 679       (info->bfd_arch_info, tdesc_architecture (info->target_desc));
 680   /* From the default.  */
 681   if (info->bfd_arch_info == NULL)
 682     info->bfd_arch_info = default_bfd_arch;
 683
 684   /* "(gdb) set byte-order ...".  */
 685   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 686       && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
 687     info->byte_order = target_byte_order_user;
 688   /* From the INFO struct.  */
 689   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 690       && info->abfd != NULL)
 691     info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
 692                         : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
 693                         : BFD_ENDIAN_UNKNOWN);
 694   /* From the default.  */
 695   if (info->byte_order == BFD_ENDIAN_UNKNOWN)
 696     info->byte_order = default_byte_order;
 697
 698   /* "(gdb) set osabi ...".  Handled by gdbarch_lookup_osabi.  */
 699   if (info->osabi == GDB_OSABI_UNINITIALIZED)
 700     info->osabi = gdbarch_lookup_osabi (info->abfd);
 701
 702   /* Must have at least filled in the architecture.  */
 703   gdb_assert (info->bfd_arch_info != NULL);
 704 }
 705
 706 /* */
 707
 708 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
 709
 710 void
 711 _initialize_gdbarch_utils (void)
 712 {
 713   struct cmd_list_element *c;
 714   add_setshow_enum_cmd ("endian", class_support,
 715                         endian_enum, &set_endian_string, _("\
 716 Set endianness of target."), _("\
 717 Show endianness of target."), NULL,
 718                         set_endian, show_endian,
 719                         &setlist, &showlist);
 720 }