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                        && gdbarch_deprecated_use_struct_convention
  58                             (current_gdbarch, 0, valtype));
  59
  60   if (writebuf != NULL)
  61     {
  62       gdb_assert (!struct_return);
  63       /* NOTE: cagney/2004-06-13: See stack.c:return_command.  Old
  64          architectures don't expect store_return_value to handle small
  65          structures.  Should not be called with such types.  */
  66       gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_STRUCT
  67                   && TYPE_CODE (valtype) != TYPE_CODE_UNION);
  68       gdbarch_store_return_value (current_gdbarch, valtype, regcache, writebuf);
  69     }
  70
  71   if (readbuf != NULL)
  72     {
  73       gdb_assert (!struct_return);
  74       gdbarch_extract_return_value (current_gdbarch,
  75                                     valtype, regcache, readbuf);
  76     }
  77
  78   if (struct_return)
  79     return RETURN_VALUE_STRUCT_CONVENTION;
  80   else
  81     return RETURN_VALUE_REGISTER_CONVENTION;
  82 }
  83
  84 int
  85 legacy_register_sim_regno (int regnum)
  86 {
  87   /* Only makes sense to supply raw registers.  */
  88   gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (current_gdbarch));
  89   /* NOTE: cagney/2002-05-13: The old code did it this way and it is
  90      suspected that some GDB/SIM combinations may rely on this
  91      behavour.  The default should be one2one_register_sim_regno
  92      (below).  */
  93   if (gdbarch_register_name (current_gdbarch, regnum) != NULL
  94       && gdbarch_register_name (current_gdbarch, regnum)[0] != '\0')
  95     return regnum;
  96   else
  97     return LEGACY_SIM_REGNO_IGNORE;
  98 }
  99
 100 CORE_ADDR
 101 generic_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
 102 {
 103   return 0;
 104 }
 105
 106 CORE_ADDR
 107 generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
 108 {
 109   return 0;
 110 }
 111
 112 int
 113 generic_in_solib_return_trampoline (CORE_ADDR pc, char *name)
 114 {
 115   return 0;
 116 }
 117
 118 int
 119 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 120 {
 121   return 0;
 122 }
 123
 124 /* Helper functions for gdbarch_inner_than */
 125
 126 int
 127 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 128 {
 129   return (lhs < rhs);
 130 }
 131
 132 int
 133 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 134 {
 135   return (lhs > rhs);
 136 }
 137
 138 /* Misc helper functions for targets. */
 139
 140 CORE_ADDR
 141 core_addr_identity (CORE_ADDR addr)
 142 {
 143   return addr;
 144 }
 145
 146 CORE_ADDR
 147 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
 148                                      struct target_ops *targ)
 149 {
 150   return addr;
 151 }
 152
 153 int
 154 no_op_reg_to_regnum (int reg)
 155 {
 156   return reg;
 157 }
 158
 159 void
 160 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 161 {
 162   return;
 163 }
 164
 165 void
 166 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 167 {
 168   return;
 169 }
 170
 171 int
 172 cannot_register_not (int regnum)
 173 {
 174   return 0;
 175 }
 176
 177 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 178    there is an gdbarch_deprecated_fp_regnum and that it is the same, cooked or
 179    raw.  */
 180
 181 void
 182 legacy_virtual_frame_pointer (CORE_ADDR pc,
 183                               int *frame_regnum,
 184                               LONGEST *frame_offset)
 185 {
 186   /* FIXME: cagney/2002-09-13: This code is used when identifying the
 187      frame pointer of the current PC.  It is assuming that a single
 188      register and an offset can determine this.  I think it should
 189      instead generate a byte code expression as that would work better
 190      with things like Dwarf2's CFI.  */
 191   if (gdbarch_deprecated_fp_regnum (current_gdbarch) >= 0
 192       && gdbarch_deprecated_fp_regnum (current_gdbarch)
 193            < gdbarch_num_regs (current_gdbarch))
 194     *frame_regnum = gdbarch_deprecated_fp_regnum (current_gdbarch);
 195   else if (gdbarch_sp_regnum (current_gdbarch) >= 0
 196            && gdbarch_sp_regnum (current_gdbarch)
 197                 < gdbarch_num_regs (current_gdbarch))
 198     *frame_regnum = gdbarch_sp_regnum (current_gdbarch);
 199   else
 200     /* Should this be an internal error?  I guess so, it is reflecting
 201        an architectural limitation in the current design.  */
 202     internal_error (__FILE__, __LINE__, _("No virtual frame pointer available"));
 203   *frame_offset = 0;
 204 }
 205
 206 \f
 207 int
 208 generic_convert_register_p (int regnum, struct type *type)
 209 {
 210   return 0;
 211 }
 212
 213 int
 214 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
 215 {
 216   return 0;
 217 }
 218
 219 int
 220 generic_instruction_nullified (struct gdbarch *gdbarch,
 221                                struct regcache *regcache)
 222 {
 223   return 0;
 224 }
 225
 226 int
 227 default_remote_register_number (struct gdbarch *gdbarch,
 228                                 int regno)
 229 {
 230   return regno;
 231 }
 232
 233 \f
 234 /* Functions to manipulate the endianness of the target.  */
 235
 236 static int target_byte_order_user = BFD_ENDIAN_UNKNOWN;
 237
 238 static const char endian_big[] = "big";
 239 static const char endian_little[] = "little";
 240 static const char endian_auto[] = "auto";
 241 static const char *endian_enum[] =
 242 {
 243   endian_big,
 244   endian_little,
 245   endian_auto,
 246   NULL,
 247 };
 248 static const char *set_endian_string;
 249
 250 enum bfd_endian
 251 selected_byte_order (void)
 252 {
 253   if (target_byte_order_user != BFD_ENDIAN_UNKNOWN)
 254     return gdbarch_byte_order (current_gdbarch);
 255   else
 256     return BFD_ENDIAN_UNKNOWN;
 257 }
 258
 259 /* Called by ``show endian''.  */
 260
 261 static void
 262 show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c,
 263              const char *value)
 264 {
 265   if (target_byte_order_user == BFD_ENDIAN_UNKNOWN)
 266     if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
 267       fprintf_unfiltered (file, _("The target endianness is set automatically "
 268                                   "(currently big endian)\n"));
 269     else
 270       fprintf_unfiltered (file, _("The target endianness is set automatically "
 271                            "(currently little endian)\n"));
 272   else
 273     if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
 274       fprintf_unfiltered (file,
 275                           _("The target is assumed to be big endian\n"));
 276     else
 277       fprintf_unfiltered (file,
 278                           _("The target is assumed to be little endian\n"));
 279 }
 280
 281 static void
 282 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 283 {
 284   struct gdbarch_info info;
 285
 286   gdbarch_info_init (&info);
 287
 288   if (set_endian_string == endian_auto)
 289     {
 290       target_byte_order_user = BFD_ENDIAN_UNKNOWN;
 291       if (! gdbarch_update_p (info))
 292         internal_error (__FILE__, __LINE__,
 293                         _("set_endian: architecture update failed"));
 294     }
 295   else if (set_endian_string == endian_little)
 296     {
 297       info.byte_order = BFD_ENDIAN_LITTLE;
 298       if (! gdbarch_update_p (info))
 299         printf_unfiltered (_("Little endian target not supported by GDB\n"));
 300       else
 301         target_byte_order_user = BFD_ENDIAN_LITTLE;
 302     }
 303   else if (set_endian_string == endian_big)
 304     {
 305       info.byte_order = BFD_ENDIAN_BIG;
 306       if (! gdbarch_update_p (info))
 307         printf_unfiltered (_("Big endian target not supported by GDB\n"));
 308       else
 309         target_byte_order_user = BFD_ENDIAN_BIG;
 310     }
 311   else
 312     internal_error (__FILE__, __LINE__,
 313                     _("set_endian: bad value"));
 314
 315   show_endian (gdb_stdout, from_tty, NULL, NULL);
 316 }
 317
 318 /* Given SELECTED, a currently selected BFD architecture, and
 319    FROM_TARGET, a BFD architecture reported by the target description,
 320    return what architecture to use.  Either may be NULL; if both are
 321    specified, we use the more specific.  If the two are obviously
 322    incompatible, warn the user.  */
 323
 324 static const struct bfd_arch_info *
 325 choose_architecture_for_target (const struct bfd_arch_info *selected,
 326                                 const struct bfd_arch_info *from_target)
 327 {
 328   const struct bfd_arch_info *compat1, *compat2;
 329
 330   if (selected == NULL)
 331     return from_target;
 332
 333   if (from_target == NULL)
 334     return selected;
 335
 336   /* struct bfd_arch_info objects are singletons: that is, there's
 337      supposed to be exactly one instance for a given machine.  So you
 338      can tell whether two are equivalent by comparing pointers.  */
 339   if (from_target == selected)
 340     return selected;
 341
 342   /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
 343      incompatible.  But if they are compatible, it returns the 'more
 344      featureful' of the two arches.  That is, if A can run code
 345      written for B, but B can't run code written for A, then it'll
 346      return A.
 347
 348      Some targets (e.g. MIPS as of 2006-12-04) don't fully
 349      implement this, instead always returning NULL or the first
 350      argument.  We detect that case by checking both directions.  */
 351
 352   compat1 = selected->compatible (selected, from_target);
 353   compat2 = from_target->compatible (from_target, selected);
 354
 355   if (compat1 == NULL && compat2 == NULL)
 356     {
 357       warning (_("Selected architecture %s is not compatible "
 358                  "with reported target architecture %s"),
 359                selected->printable_name, from_target->printable_name);
 360       return selected;
 361     }
 362
 363   if (compat1 == NULL)
 364     return compat2;
 365   if (compat2 == NULL)
 366     return compat1;
 367   if (compat1 == compat2)
 368     return compat1;
 369
 370   /* If the two didn't match, but one of them was a default architecture,
 371      assume the more specific one is correct.  This handles the case
 372      where an executable or target description just says "mips", but
 373      the other knows which MIPS variant.  */
 374   if (compat1->the_default)
 375     return compat2;
 376   if (compat2->the_default)
 377     return compat1;
 378
 379   /* We have no idea which one is better.  This is a bug, but not
 380      a critical problem; warn the user.  */
 381   warning (_("Selected architecture %s is ambiguous with "
 382              "reported target architecture %s"),
 383            selected->printable_name, from_target->printable_name);
 384   return selected;
 385 }
 386
 387 /* Functions to manipulate the architecture of the target */
 388
 389 enum set_arch { set_arch_auto, set_arch_manual };
 390
 391 static const struct bfd_arch_info *target_architecture_user;
 392
 393 static const char *set_architecture_string;
 394
 395 const char *
 396 selected_architecture_name (void)
 397 {
 398   if (target_architecture_user == NULL)
 399     return NULL;
 400   else
 401     return set_architecture_string;
 402 }
 403
 404 /* Called if the user enters ``show architecture'' without an
 405    argument. */
 406
 407 static void
 408 show_architecture (struct ui_file *file, int from_tty,
 409                    struct cmd_list_element *c, const char *value)
 410 {
 411   const char *arch;
 412   arch = gdbarch_bfd_arch_info (current_gdbarch)->printable_name;
 413   if (target_architecture_user == NULL)
 414     fprintf_filtered (file, _("\
 415 The target architecture is set automatically (currently %s)\n"), arch);
 416   else
 417     fprintf_filtered (file, _("\
 418 The target architecture is assumed to be %s\n"), arch);
 419 }
 420
 421
 422 /* Called if the user enters ``set architecture'' with or without an
 423    argument. */
 424
 425 static void
 426 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 427 {
 428   struct gdbarch_info info;
 429
 430   gdbarch_info_init (&info);
 431
 432   if (strcmp (set_architecture_string, "auto") == 0)
 433     {
 434       target_architecture_user = NULL;
 435       if (!gdbarch_update_p (info))
 436         internal_error (__FILE__, __LINE__,
 437                         _("could not select an architecture automatically"));
 438     }
 439   else
 440     {
 441       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 442       if (info.bfd_arch_info == NULL)
 443         internal_error (__FILE__, __LINE__,
 444                         _("set_architecture: bfd_scan_arch failed"));
 445       if (gdbarch_update_p (info))
 446         target_architecture_user = info.bfd_arch_info;
 447       else
 448         printf_unfiltered (_("Architecture `%s' not recognized.\n"),
 449                            set_architecture_string);
 450     }
 451   show_architecture (gdb_stdout, from_tty, NULL, NULL);
 452 }
 453
 454 /* Try to select a global architecture that matches "info".  Return
 455    non-zero if the attempt succeds.  */
 456 int
 457 gdbarch_update_p (struct gdbarch_info info)
 458 {
 459   struct gdbarch *new_gdbarch = gdbarch_find_by_info (info);
 460
 461   /* If there no architecture by that name, reject the request.  */
 462   if (new_gdbarch == NULL)
 463     {
 464       if (gdbarch_debug)
 465         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 466                             "Architecture not found\n");
 467       return 0;
 468     }
 469
 470   /* If it is the same old architecture, accept the request (but don't
 471      swap anything).  */
 472   if (new_gdbarch == current_gdbarch)
 473     {
 474       if (gdbarch_debug)
 475         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 476                             "Architecture 0x%08lx (%s) unchanged\n",
 477                             (long) new_gdbarch,
 478                             gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 479       return 1;
 480     }
 481
 482   /* It's a new architecture, swap it in.  */
 483   if (gdbarch_debug)
 484     fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 485                         "New architecture 0x%08lx (%s) selected\n",
 486                         (long) new_gdbarch,
 487                         gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 488   deprecated_current_gdbarch_select_hack (new_gdbarch);
 489
 490   return 1;
 491 }
 492
 493 /* Return the architecture for ABFD.  If no suitable architecture
 494    could be find, return NULL.  */
 495
 496 struct gdbarch *
 497 gdbarch_from_bfd (bfd *abfd)
 498 {
 499   struct gdbarch *old_gdbarch = current_gdbarch;
 500   struct gdbarch *new_gdbarch;
 501   struct gdbarch_info info;
 502
 503   /* If we call gdbarch_find_by_info without filling in info.abfd,
 504      then it will use the global exec_bfd.  That's fine if we don't
 505      have one of those either.  And that's the only time we should
 506      reach here with a NULL ABFD argument - when we are discarding
 507      the executable.  */
 508   gdb_assert (abfd != NULL || exec_bfd == NULL);
 509
 510   gdbarch_info_init (&info);
 511   info.abfd = abfd;
 512   return gdbarch_find_by_info (info);
 513 }
 514
 515 /* Set the dynamic target-system-dependent parameters (architecture,
 516    byte-order) using information found in the BFD */
 517
 518 void
 519 set_gdbarch_from_file (bfd *abfd)
 520 {
 521   struct gdbarch *gdbarch;
 522
 523   gdbarch = gdbarch_from_bfd (abfd);
 524   if (gdbarch == NULL)
 525     error (_("Architecture of file not recognized."));
 526   deprecated_current_gdbarch_select_hack (gdbarch);
 527 }
 528
 529 /* Initialize the current architecture.  Update the ``set
 530    architecture'' command so that it specifies a list of valid
 531    architectures.  */
 532
 533 #ifdef DEFAULT_BFD_ARCH
 534 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 535 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 536 #else
 537 static const bfd_arch_info_type *default_bfd_arch;
 538 #endif
 539
 540 #ifdef DEFAULT_BFD_VEC
 541 extern const bfd_target DEFAULT_BFD_VEC;
 542 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 543 #else
 544 static const bfd_target *default_bfd_vec;
 545 #endif
 546
 547 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
 548
 549 void
 550 initialize_current_architecture (void)
 551 {
 552   const char **arches = gdbarch_printable_names ();
 553
 554   /* determine a default architecture and byte order. */
 555   struct gdbarch_info info;
 556   gdbarch_info_init (&info);
 557
 558   /* Find a default architecture. */
 559   if (default_bfd_arch == NULL)
 560     {
 561       /* Choose the architecture by taking the first one
 562          alphabetically. */
 563       const char *chosen = arches[0];
 564       const char **arch;
 565       for (arch = arches; *arch != NULL; arch++)
 566         {
 567           if (strcmp (*arch, chosen) < 0)
 568             chosen = *arch;
 569         }
 570       if (chosen == NULL)
 571         internal_error (__FILE__, __LINE__,
 572                         _("initialize_current_architecture: No arch"));
 573       default_bfd_arch = bfd_scan_arch (chosen);
 574       if (default_bfd_arch == NULL)
 575         internal_error (__FILE__, __LINE__,
 576                         _("initialize_current_architecture: Arch not found"));
 577     }
 578
 579   info.bfd_arch_info = default_bfd_arch;
 580
 581   /* Take several guesses at a byte order.  */
 582   if (default_byte_order == BFD_ENDIAN_UNKNOWN
 583       && default_bfd_vec != NULL)
 584     {
 585       /* Extract BFD's default vector's byte order. */
 586       switch (default_bfd_vec->byteorder)
 587         {
 588         case BFD_ENDIAN_BIG:
 589           default_byte_order = BFD_ENDIAN_BIG;
 590           break;
 591         case BFD_ENDIAN_LITTLE:
 592           default_byte_order = BFD_ENDIAN_LITTLE;
 593           break;
 594         default:
 595           break;
 596         }
 597     }
 598   if (default_byte_order == BFD_ENDIAN_UNKNOWN)
 599     {
 600       /* look for ``*el-*'' in the target name. */
 601       const char *chp;
 602       chp = strchr (target_name, '-');
 603       if (chp != NULL
 604           && chp - 2 >= target_name
 605           && strncmp (chp - 2, "el", 2) == 0)
 606         default_byte_order = BFD_ENDIAN_LITTLE;
 607     }
 608   if (default_byte_order == BFD_ENDIAN_UNKNOWN)
 609     {
 610       /* Wire it to big-endian!!! */
 611       default_byte_order = BFD_ENDIAN_BIG;
 612     }
 613
 614   info.byte_order = default_byte_order;
 615
 616   if (! gdbarch_update_p (info))
 617     internal_error (__FILE__, __LINE__,
 618                     _("initialize_current_architecture: Selection of "
 619                       "initial architecture failed"));
 620
 621   /* Create the ``set architecture'' command appending ``auto'' to the
 622      list of architectures. */
 623   {
 624     struct cmd_list_element *c;
 625     /* Append ``auto''. */
 626     int nr;
 627     for (nr = 0; arches[nr] != NULL; nr++);
 628     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 629     arches[nr + 0] = "auto";
 630     arches[nr + 1] = NULL;
 631     add_setshow_enum_cmd ("architecture", class_support,
 632                           arches, &set_architecture_string, _("\
 633 Set architecture of target."), _("\
 634 Show architecture of target."), NULL,
 635                           set_architecture, show_architecture,
 636                           &setlist, &showlist);
 637     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 638   }
 639 }
 640
 641
 642 /* Initialize a gdbarch info to values that will be automatically
 643    overridden.  Note: Originally, this ``struct info'' was initialized
 644    using memset(0).  Unfortunately, that ran into problems, namely
 645    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 646    can explicitly set each field to a well defined value is used.  */
 647
 648 void
 649 gdbarch_info_init (struct gdbarch_info *info)
 650 {
 651   memset (info, 0, sizeof (struct gdbarch_info));
 652   info->byte_order = BFD_ENDIAN_UNKNOWN;
 653   info->osabi = GDB_OSABI_UNINITIALIZED;
 654 }
 655
 656 /* Similar to init, but this time fill in the blanks.  Information is
 657    obtained from the global "set ..." options and explicitly
 658    initialized INFO fields.  */
 659
 660 void
 661 gdbarch_info_fill (struct gdbarch_info *info)
 662 {
 663   /* Check for the current file.  */
 664   if (info->abfd == NULL)
 665     info->abfd = exec_bfd;
 666
 667   /* Check for the current target description.  */
 668   if (info->target_desc == NULL)
 669     info->target_desc = target_current_description ();
 670
 671   /* "(gdb) set architecture ...".  */
 672   if (info->bfd_arch_info == NULL
 673       && target_architecture_user)
 674     info->bfd_arch_info = target_architecture_user;
 675   /* From the file.  */
 676   if (info->bfd_arch_info == NULL
 677       && info->abfd != NULL
 678       && bfd_get_arch (info->abfd) != bfd_arch_unknown
 679       && bfd_get_arch (info->abfd) != bfd_arch_obscure)
 680     info->bfd_arch_info = bfd_get_arch_info (info->abfd);
 681   /* From the target.  */
 682   if (info->target_desc != NULL)
 683     info->bfd_arch_info = choose_architecture_for_target
 684       (info->bfd_arch_info, tdesc_architecture (info->target_desc));
 685   /* From the default.  */
 686   if (info->bfd_arch_info == NULL)
 687     info->bfd_arch_info = default_bfd_arch;
 688
 689   /* "(gdb) set byte-order ...".  */
 690   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 691       && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
 692     info->byte_order = target_byte_order_user;
 693   /* From the INFO struct.  */
 694   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 695       && info->abfd != NULL)
 696     info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
 697                         : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
 698                         : BFD_ENDIAN_UNKNOWN);
 699   /* From the default.  */
 700   if (info->byte_order == BFD_ENDIAN_UNKNOWN)
 701     info->byte_order = default_byte_order;
 702
 703   /* "(gdb) set osabi ...".  Handled by gdbarch_lookup_osabi.  */
 704   if (info->osabi == GDB_OSABI_UNINITIALIZED)
 705     info->osabi = gdbarch_lookup_osabi (info->abfd);
 706
 707   /* Must have at least filled in the architecture.  */
 708   gdb_assert (info->bfd_arch_info != NULL);
 709 }
 710
 711 /* */
 712
 713 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
 714
 715 void
 716 _initialize_gdbarch_utils (void)
 717 {
 718   struct cmd_list_element *c;
 719   add_setshow_enum_cmd ("endian", class_support,
 720                         endian_enum, &set_endian_string, _("\
 721 Set endianness of target."), _("\
 722 Show endianness of target."), NULL,
 723                         set_endian, show_endian,
 724                         &setlist, &showlist);
 725 }