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 /* Implementation of extract return value that grubs around in the
  42    register cache.  */
  43 void
  44 legacy_extract_return_value (struct type *type, struct regcache *regcache,
  45                              gdb_byte *valbuf)
  46 {
  47   gdb_byte *registers = deprecated_grub_regcache_for_registers (regcache);
  48   gdb_byte *buf = valbuf;
  49   DEPRECATED_EXTRACT_RETURN_VALUE (type, registers, buf); /* OK */
  50 }
  51
  52 /* Implementation of store return value that grubs the register cache.
  53    Takes a local copy of the buffer to avoid const problems.  */
  54 void
  55 legacy_store_return_value (struct type *type, struct regcache *regcache,
  56                            const gdb_byte *buf)
  57 {
  58   gdb_byte *b = alloca (TYPE_LENGTH (type));
  59   gdb_assert (regcache == current_regcache);
  60   memcpy (b, buf, TYPE_LENGTH (type));
  61   DEPRECATED_STORE_RETURN_VALUE (type, b);
  62 }
  63
  64 int
  65 always_use_struct_convention (int gcc_p, struct type *value_type)
  66 {
  67   return 1;
  68 }
  69
  70 enum return_value_convention
  71 legacy_return_value (struct gdbarch *gdbarch, struct type *valtype,
  72                      struct regcache *regcache, gdb_byte *readbuf,
  73                      const gdb_byte *writebuf)
  74 {
  75   /* NOTE: cagney/2004-06-13: The gcc_p parameter to
  76      USE_STRUCT_CONVENTION isn't used.  */
  77   int struct_return = ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
  78                         || TYPE_CODE (valtype) == TYPE_CODE_UNION
  79                         || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
  80                        && DEPRECATED_USE_STRUCT_CONVENTION (0, valtype));
  81
  82   if (writebuf != NULL)
  83     {
  84       gdb_assert (!struct_return);
  85       /* NOTE: cagney/2004-06-13: See stack.c:return_command.  Old
  86          architectures don't expect STORE_RETURN_VALUE to handle small
  87          structures.  Should not be called with such types.  */
  88       gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_STRUCT
  89                   && TYPE_CODE (valtype) != TYPE_CODE_UNION);
  90       STORE_RETURN_VALUE (valtype, regcache, writebuf);
  91     }
  92
  93   if (readbuf != NULL)
  94     {
  95       gdb_assert (!struct_return);
  96       EXTRACT_RETURN_VALUE (valtype, regcache, readbuf);
  97     }
  98
  99   if (struct_return)
 100     return RETURN_VALUE_STRUCT_CONVENTION;
 101   else
 102     return RETURN_VALUE_REGISTER_CONVENTION;
 103 }
 104
 105 int
 106 legacy_register_sim_regno (int regnum)
 107 {
 108   /* Only makes sense to supply raw registers.  */
 109   gdb_assert (regnum >= 0 && regnum < NUM_REGS);
 110   /* NOTE: cagney/2002-05-13: The old code did it this way and it is
 111      suspected that some GDB/SIM combinations may rely on this
 112      behavour.  The default should be one2one_register_sim_regno
 113      (below).  */
 114   if (REGISTER_NAME (regnum) != NULL
 115       && REGISTER_NAME (regnum)[0] != '\0')
 116     return regnum;
 117   else
 118     return LEGACY_SIM_REGNO_IGNORE;
 119 }
 120
 121 CORE_ADDR
 122 generic_skip_trampoline_code (CORE_ADDR pc)
 123 {
 124   return 0;
 125 }
 126
 127 CORE_ADDR
 128 generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
 129 {
 130   return 0;
 131 }
 132
 133 int
 134 generic_in_solib_return_trampoline (CORE_ADDR pc, char *name)
 135 {
 136   return 0;
 137 }
 138
 139 int
 140 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
 141 {
 142   return 0;
 143 }
 144
 145 void
 146 generic_remote_translate_xfer_address (struct gdbarch *gdbarch,
 147                                        struct regcache *regcache,
 148                                        CORE_ADDR gdb_addr, int gdb_len,
 149                                        CORE_ADDR * rem_addr, int *rem_len)
 150 {
 151   *rem_addr = gdb_addr;
 152   *rem_len = gdb_len;
 153 }
 154
 155 /* Helper functions for INNER_THAN */
 156
 157 int
 158 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 159 {
 160   return (lhs < rhs);
 161 }
 162
 163 int
 164 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 165 {
 166   return (lhs > rhs);
 167 }
 168
 169
 170 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 171
 172 const struct floatformat *
 173 default_float_format (struct gdbarch *gdbarch)
 174 {
 175   int byte_order = gdbarch_byte_order (gdbarch);
 176   switch (byte_order)
 177     {
 178     case BFD_ENDIAN_BIG:
 179       return &floatformat_ieee_single_big;
 180     case BFD_ENDIAN_LITTLE:
 181       return &floatformat_ieee_single_little;
 182     default:
 183       internal_error (__FILE__, __LINE__,
 184                       _("default_float_format: bad byte order"));
 185     }
 186 }
 187
 188
 189 const struct floatformat *
 190 default_double_format (struct gdbarch *gdbarch)
 191 {
 192   int byte_order = gdbarch_byte_order (gdbarch);
 193   switch (byte_order)
 194     {
 195     case BFD_ENDIAN_BIG:
 196       return &floatformat_ieee_double_big;
 197     case BFD_ENDIAN_LITTLE:
 198       return &floatformat_ieee_double_little;
 199     default:
 200       internal_error (__FILE__, __LINE__,
 201                       _("default_double_format: bad byte order"));
 202     }
 203 }
 204
 205 /* Misc helper functions for targets. */
 206
 207 CORE_ADDR
 208 core_addr_identity (CORE_ADDR addr)
 209 {
 210   return addr;
 211 }
 212
 213 CORE_ADDR
 214 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
 215                                      struct target_ops *targ)
 216 {
 217   return addr;
 218 }
 219
 220 int
 221 no_op_reg_to_regnum (int reg)
 222 {
 223   return reg;
 224 }
 225
 226 void
 227 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
 228 {
 229   return;
 230 }
 231
 232 void
 233 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
 234 {
 235   return;
 236 }
 237
 238 int
 239 cannot_register_not (int regnum)
 240 {
 241   return 0;
 242 }
 243
 244 /* Legacy version of target_virtual_frame_pointer().  Assumes that
 245    there is an DEPRECATED_FP_REGNUM and that it is the same, cooked or
 246    raw.  */
 247
 248 void
 249 legacy_virtual_frame_pointer (CORE_ADDR pc,
 250                               int *frame_regnum,
 251                               LONGEST *frame_offset)
 252 {
 253   /* FIXME: cagney/2002-09-13: This code is used when identifying the
 254      frame pointer of the current PC.  It is assuming that a single
 255      register and an offset can determine this.  I think it should
 256      instead generate a byte code expression as that would work better
 257      with things like Dwarf2's CFI.  */
 258   if (DEPRECATED_FP_REGNUM >= 0 && DEPRECATED_FP_REGNUM < NUM_REGS)
 259     *frame_regnum = DEPRECATED_FP_REGNUM;
 260   else if (SP_REGNUM >= 0 && SP_REGNUM < NUM_REGS)
 261     *frame_regnum = SP_REGNUM;
 262   else
 263     /* Should this be an internal error?  I guess so, it is reflecting
 264        an architectural limitation in the current design.  */
 265     internal_error (__FILE__, __LINE__, _("No virtual frame pointer available"));
 266   *frame_offset = 0;
 267 }
 268
 269 /* Assume the world is sane, every register's virtual and real size
 270    is identical.  */
 271
 272 int
 273 generic_register_size (int regnum)
 274 {
 275   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 276   return TYPE_LENGTH (gdbarch_register_type (current_gdbarch, regnum));
 277 }
 278
 279 /* Assume all registers are adjacent.  */
 280
 281 int
 282 generic_register_byte (int regnum)
 283 {
 284   int byte;
 285   int i;
 286   gdb_assert (regnum >= 0 && regnum < NUM_REGS + NUM_PSEUDO_REGS);
 287   byte = 0;
 288   for (i = 0; i < regnum; i++)
 289     {
 290       byte += generic_register_size (i);
 291     }
 292   return byte;
 293 }
 294
 295 \f
 296 int
 297 legacy_pc_in_sigtramp (CORE_ADDR pc, char *name)
 298 {
 299 #if defined (DEPRECATED_IN_SIGTRAMP)
 300   return DEPRECATED_IN_SIGTRAMP (pc, name);
 301 #else
 302   return name && strcmp ("_sigtramp", name) == 0;
 303 #endif
 304 }
 305
 306 int
 307 generic_convert_register_p (int regnum, struct type *type)
 308 {
 309   return 0;
 310 }
 311
 312 int
 313 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
 314 {
 315   if (DEPRECATED_REG_STRUCT_HAS_ADDR_P ()
 316       && DEPRECATED_REG_STRUCT_HAS_ADDR (processing_gcc_compilation, type))
 317     {
 318       CHECK_TYPEDEF (type);
 319
 320       return (TYPE_CODE (type) == TYPE_CODE_STRUCT
 321               || TYPE_CODE (type) == TYPE_CODE_UNION
 322               || TYPE_CODE (type) == TYPE_CODE_SET
 323               || TYPE_CODE (type) == TYPE_CODE_BITSTRING);
 324     }
 325
 326   return 0;
 327 }
 328
 329 int
 330 generic_instruction_nullified (struct gdbarch *gdbarch,
 331                                struct regcache *regcache)
 332 {
 333   return 0;
 334 }
 335
 336 \f
 337 /* Functions to manipulate the endianness of the target.  */
 338
 339 static int target_byte_order_user = BFD_ENDIAN_UNKNOWN;
 340
 341 static const char endian_big[] = "big";
 342 static const char endian_little[] = "little";
 343 static const char endian_auto[] = "auto";
 344 static const char *endian_enum[] =
 345 {
 346   endian_big,
 347   endian_little,
 348   endian_auto,
 349   NULL,
 350 };
 351 static const char *set_endian_string;
 352
 353 /* Called by ``show endian''.  */
 354
 355 static void
 356 show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c,
 357              const char *value)
 358 {
 359   if (target_byte_order_user != BFD_ENDIAN_UNKNOWN)
 360     if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
 361       fprintf_unfiltered (file, _("The target endianness is set automatically "
 362                                   "(currently big endian)\n"));
 363     else
 364       fprintf_unfiltered (file, _("The target endianness is set automatically "
 365                            "(currently little endian)\n"));
 366   else
 367     if (TARGET_BYTE_ORDER == BFD_ENDIAN_BIG)
 368       fprintf_unfiltered (file,
 369                           _("The target is assumed to be big endian\n"));
 370     else
 371       fprintf_unfiltered (file,
 372                           _("The target is assumed to be little endian\n"));
 373 }
 374
 375 static void
 376 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 377 {
 378   struct gdbarch_info info;
 379
 380   gdbarch_info_init (&info);
 381
 382   if (set_endian_string == endian_auto)
 383     {
 384       target_byte_order_user = BFD_ENDIAN_UNKNOWN;
 385       if (! gdbarch_update_p (info))
 386         internal_error (__FILE__, __LINE__,
 387                         _("set_endian: architecture update failed"));
 388     }
 389   else if (set_endian_string == endian_little)
 390     {
 391       info.byte_order = BFD_ENDIAN_LITTLE;
 392       if (! gdbarch_update_p (info))
 393         printf_unfiltered (_("Little endian target not supported by GDB\n"));
 394       else
 395         target_byte_order_user = BFD_ENDIAN_LITTLE;
 396     }
 397   else if (set_endian_string == endian_big)
 398     {
 399       info.byte_order = BFD_ENDIAN_BIG;
 400       if (! gdbarch_update_p (info))
 401         printf_unfiltered (_("Big endian target not supported by GDB\n"));
 402       else
 403         target_byte_order_user = BFD_ENDIAN_BIG;
 404     }
 405   else
 406     internal_error (__FILE__, __LINE__,
 407                     _("set_endian: bad value"));
 408
 409   show_endian (gdb_stdout, from_tty, NULL, NULL);
 410 }
 411
 412 /* Functions to manipulate the architecture of the target */
 413
 414 enum set_arch { set_arch_auto, set_arch_manual };
 415
 416 static const struct bfd_arch_info *target_architecture_user;
 417
 418 static const char *set_architecture_string;
 419
 420 const char *
 421 selected_architecture_name (void)
 422 {
 423   if (target_architecture_user == NULL)
 424     return NULL;
 425   else
 426     return set_architecture_string;
 427 }
 428
 429 /* Called if the user enters ``show architecture'' without an
 430    argument. */
 431
 432 static void
 433 show_architecture (struct ui_file *file, int from_tty,
 434                    struct cmd_list_element *c, const char *value)
 435 {
 436   const char *arch;
 437   arch = TARGET_ARCHITECTURE->printable_name;
 438   if (target_architecture_user == NULL)
 439     fprintf_filtered (file, _("\
 440 The target architecture is set automatically (currently %s)\n"), arch);
 441   else
 442     fprintf_filtered (file, _("\
 443 The target architecture is assumed to be %s\n"), arch);
 444 }
 445
 446
 447 /* Called if the user enters ``set architecture'' with or without an
 448    argument. */
 449
 450 static void
 451 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 452 {
 453   struct gdbarch_info info;
 454
 455   gdbarch_info_init (&info);
 456
 457   if (strcmp (set_architecture_string, "auto") == 0)
 458     {
 459       target_architecture_user = NULL;
 460       if (!gdbarch_update_p (info))
 461         internal_error (__FILE__, __LINE__,
 462                         _("could not select an architecture automatically"));
 463     }
 464   else
 465     {
 466       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 467       if (info.bfd_arch_info == NULL)
 468         internal_error (__FILE__, __LINE__,
 469                         _("set_architecture: bfd_scan_arch failed"));
 470       if (gdbarch_update_p (info))
 471         target_architecture_user = info.bfd_arch_info;
 472       else
 473         printf_unfiltered (_("Architecture `%s' not recognized.\n"),
 474                            set_architecture_string);
 475     }
 476   show_architecture (gdb_stdout, from_tty, NULL, NULL);
 477 }
 478
 479 /* Try to select a global architecture that matches "info".  Return
 480    non-zero if the attempt succeds.  */
 481 int
 482 gdbarch_update_p (struct gdbarch_info info)
 483 {
 484   struct gdbarch *new_gdbarch = gdbarch_find_by_info (info);
 485
 486   /* If there no architecture by that name, reject the request.  */
 487   if (new_gdbarch == NULL)
 488     {
 489       if (gdbarch_debug)
 490         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 491                             "Architecture not found\n");
 492       return 0;
 493     }
 494
 495   /* If it is the same old architecture, accept the request (but don't
 496      swap anything).  */
 497   if (new_gdbarch == current_gdbarch)
 498     {
 499       if (gdbarch_debug)
 500         fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 501                             "Architecture 0x%08lx (%s) unchanged\n",
 502                             (long) new_gdbarch,
 503                             gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 504       return 1;
 505     }
 506
 507   /* It's a new architecture, swap it in.  */
 508   if (gdbarch_debug)
 509     fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
 510                         "New architecture 0x%08lx (%s) selected\n",
 511                         (long) new_gdbarch,
 512                         gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
 513   deprecated_current_gdbarch_select_hack (new_gdbarch);
 514
 515   return 1;
 516 }
 517
 518 /* Return the architecture for ABFD.  If no suitable architecture
 519    could be find, return NULL.  */
 520
 521 struct gdbarch *
 522 gdbarch_from_bfd (bfd *abfd)
 523 {
 524   struct gdbarch *old_gdbarch = current_gdbarch;
 525   struct gdbarch *new_gdbarch;
 526   struct gdbarch_info info;
 527
 528   /* If we call gdbarch_find_by_info without filling in info.abfd,
 529      then it will use the global exec_bfd.  That's fine if we don't
 530      have one of those either.  And that's the only time we should
 531      reach here with a NULL ABFD argument - when we are discarding
 532      the executable.  */
 533   gdb_assert (abfd != NULL || exec_bfd == NULL);
 534
 535   gdbarch_info_init (&info);
 536   info.abfd = abfd;
 537   return gdbarch_find_by_info (info);
 538 }
 539
 540 /* Set the dynamic target-system-dependent parameters (architecture,
 541    byte-order) using information found in the BFD */
 542
 543 void
 544 set_gdbarch_from_file (bfd *abfd)
 545 {
 546   struct gdbarch *gdbarch;
 547
 548   gdbarch = gdbarch_from_bfd (abfd);
 549   if (gdbarch == NULL)
 550     error (_("Architecture of file not recognized."));
 551   deprecated_current_gdbarch_select_hack (gdbarch);
 552 }
 553
 554 /* Initialize the current architecture.  Update the ``set
 555    architecture'' command so that it specifies a list of valid
 556    architectures.  */
 557
 558 #ifdef DEFAULT_BFD_ARCH
 559 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 560 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 561 #else
 562 static const bfd_arch_info_type *default_bfd_arch;
 563 #endif
 564
 565 #ifdef DEFAULT_BFD_VEC
 566 extern const bfd_target DEFAULT_BFD_VEC;
 567 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 568 #else
 569 static const bfd_target *default_bfd_vec;
 570 #endif
 571
 572 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
 573
 574 void
 575 initialize_current_architecture (void)
 576 {
 577   const char **arches = gdbarch_printable_names ();
 578
 579   /* determine a default architecture and byte order. */
 580   struct gdbarch_info info;
 581   gdbarch_info_init (&info);
 582
 583   /* Find a default architecture. */
 584   if (default_bfd_arch == NULL)
 585     {
 586       /* Choose the architecture by taking the first one
 587          alphabetically. */
 588       const char *chosen = arches[0];
 589       const char **arch;
 590       for (arch = arches; *arch != NULL; arch++)
 591         {
 592           if (strcmp (*arch, chosen) < 0)
 593             chosen = *arch;
 594         }
 595       if (chosen == NULL)
 596         internal_error (__FILE__, __LINE__,
 597                         _("initialize_current_architecture: No arch"));
 598       default_bfd_arch = bfd_scan_arch (chosen);
 599       if (default_bfd_arch == NULL)
 600         internal_error (__FILE__, __LINE__,
 601                         _("initialize_current_architecture: Arch not found"));
 602     }
 603
 604   info.bfd_arch_info = default_bfd_arch;
 605
 606   /* Take several guesses at a byte order.  */
 607   if (default_byte_order == BFD_ENDIAN_UNKNOWN
 608       && default_bfd_vec != NULL)
 609     {
 610       /* Extract BFD's default vector's byte order. */
 611       switch (default_bfd_vec->byteorder)
 612         {
 613         case BFD_ENDIAN_BIG:
 614           default_byte_order = BFD_ENDIAN_BIG;
 615           break;
 616         case BFD_ENDIAN_LITTLE:
 617           default_byte_order = BFD_ENDIAN_LITTLE;
 618           break;
 619         default:
 620           break;
 621         }
 622     }
 623   if (default_byte_order == BFD_ENDIAN_UNKNOWN)
 624     {
 625       /* look for ``*el-*'' in the target name. */
 626       const char *chp;
 627       chp = strchr (target_name, '-');
 628       if (chp != NULL
 629           && chp - 2 >= target_name
 630           && strncmp (chp - 2, "el", 2) == 0)
 631         default_byte_order = BFD_ENDIAN_LITTLE;
 632     }
 633   if (default_byte_order == BFD_ENDIAN_UNKNOWN)
 634     {
 635       /* Wire it to big-endian!!! */
 636       default_byte_order = BFD_ENDIAN_BIG;
 637     }
 638
 639   info.byte_order = default_byte_order;
 640
 641   if (! gdbarch_update_p (info))
 642     internal_error (__FILE__, __LINE__,
 643                     _("initialize_current_architecture: Selection of "
 644                       "initial architecture failed"));
 645
 646   /* Create the ``set architecture'' command appending ``auto'' to the
 647      list of architectures. */
 648   {
 649     struct cmd_list_element *c;
 650     /* Append ``auto''. */
 651     int nr;
 652     for (nr = 0; arches[nr] != NULL; nr++);
 653     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 654     arches[nr + 0] = "auto";
 655     arches[nr + 1] = NULL;
 656     add_setshow_enum_cmd ("architecture", class_support,
 657                           arches, &set_architecture_string, _("\
 658 Set architecture of target."), _("\
 659 Show architecture of target."), NULL,
 660                           set_architecture, show_architecture,
 661                           &setlist, &showlist);
 662     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 663   }
 664 }
 665
 666
 667 /* Initialize a gdbarch info to values that will be automatically
 668    overridden.  Note: Originally, this ``struct info'' was initialized
 669    using memset(0).  Unfortunately, that ran into problems, namely
 670    BFD_ENDIAN_BIG is zero.  An explicit initialization function that
 671    can explicitly set each field to a well defined value is used.  */
 672
 673 void
 674 gdbarch_info_init (struct gdbarch_info *info)
 675 {
 676   memset (info, 0, sizeof (struct gdbarch_info));
 677   info->byte_order = BFD_ENDIAN_UNKNOWN;
 678   info->osabi = GDB_OSABI_UNINITIALIZED;
 679 }
 680
 681 /* Similar to init, but this time fill in the blanks.  Information is
 682    obtained from the global "set ..." options and explicitly
 683    initialized INFO fields.  */
 684
 685 void
 686 gdbarch_info_fill (struct gdbarch_info *info)
 687 {
 688   /* Check for the current file.  */
 689   if (info->abfd == NULL)
 690     info->abfd = exec_bfd;
 691
 692   /* Check for the current target description.  */
 693   if (info->target_desc == NULL)
 694     info->target_desc = target_current_description ();
 695
 696   /* "(gdb) set architecture ...".  */
 697   if (info->bfd_arch_info == NULL
 698       && target_architecture_user)
 699     info->bfd_arch_info = target_architecture_user;
 700   /* From the file.  */
 701   if (info->bfd_arch_info == NULL
 702       && info->abfd != NULL
 703       && bfd_get_arch (info->abfd) != bfd_arch_unknown
 704       && bfd_get_arch (info->abfd) != bfd_arch_obscure)
 705     info->bfd_arch_info = bfd_get_arch_info (info->abfd);
 706   /* From the default.  */
 707   if (info->bfd_arch_info == NULL)
 708     info->bfd_arch_info = default_bfd_arch;
 709
 710   /* "(gdb) set byte-order ...".  */
 711   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 712       && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
 713     info->byte_order = target_byte_order_user;
 714   /* From the INFO struct.  */
 715   if (info->byte_order == BFD_ENDIAN_UNKNOWN
 716       && info->abfd != NULL)
 717     info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
 718                         : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
 719                         : BFD_ENDIAN_UNKNOWN);
 720   /* From the default.  */
 721   if (info->byte_order == BFD_ENDIAN_UNKNOWN)
 722     info->byte_order = default_byte_order;
 723
 724   /* "(gdb) set osabi ...".  Handled by gdbarch_lookup_osabi.  */
 725   if (info->osabi == GDB_OSABI_UNINITIALIZED)
 726     info->osabi = gdbarch_lookup_osabi (info->abfd);
 727
 728   /* Must have at least filled in the architecture.  */
 729   gdb_assert (info->bfd_arch_info != NULL);
 730 }
 731
 732 /* */
 733
 734 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
 735
 736 void
 737 _initialize_gdbarch_utils (void)
 738 {
 739   struct cmd_list_element *c;
 740   add_setshow_enum_cmd ("endian", class_support,
 741                         endian_enum, &set_endian_string, _("\
 742 Set endianness of target."), _("\
 743 Show endianness of target."), NULL,
 744                         set_endian, show_endian,
 745                         &setlist, &showlist);
 746 }