gdb/arch-utils.c

   1 /* Dynamic architecture support for GDB, the GNU debugger.
   2    Copyright 1998-1999, Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22
  23 #if GDB_MULTI_ARCH
  24 #include "gdbcmd.h"
  25 #include "inferior.h"           /* enum CALL_DUMMY_LOCATION et.al. */
  26 #else
  27 /* Just include everything in sight so that the every old definition
  28    of macro is visible. */
  29 #include "gdb_string.h"
  30 #include <ctype.h>
  31 #include "symtab.h"
  32 #include "frame.h"
  33 #include "inferior.h"
  34 #include "breakpoint.h"
  35 #include "gdb_wait.h"
  36 #include "gdbcore.h"
  37 #include "gdbcmd.h"
  38 #include "target.h"
  39 #include "gdbthread.h"
  40 #include "annotate.h"
  41 #include "symfile.h"            /* for overlay functions */
  42 #endif
  43
  44 #include "version.h"
  45
  46 #include "floatformat.h"
  47
  48 /* Convenience macro for allocting typesafe memory. */
  49
  50 #ifndef XMALLOC
  51 #define XMALLOC(TYPE) (TYPE*) xmalloc (sizeof (TYPE))
  52 #endif
  53
  54
  55 /* Use the program counter to determine the contents and size
  56    of a breakpoint instruction.  If no target-dependent macro
  57    BREAKPOINT_FROM_PC has been defined to implement this function,
  58    assume that the breakpoint doesn't depend on the PC, and
  59    use the values of the BIG_BREAKPOINT and LITTLE_BREAKPOINT macros.
  60    Return a pointer to a string of bytes that encode a breakpoint
  61    instruction, stores the length of the string to *lenptr,
  62    and optionally adjust the pc to point to the correct memory location
  63    for inserting the breakpoint.  */
  64
  65 unsigned char *
  66 legacy_breakpoint_from_pc (CORE_ADDR * pcptr, int *lenptr)
  67 {
  68   /* {BIG_,LITTLE_}BREAKPOINT is the sequence of bytes we insert for a
  69      breakpoint.  On some machines, breakpoints are handled by the
  70      target environment and we don't have to worry about them here.  */
  71 #ifdef BIG_BREAKPOINT
  72   if (TARGET_BYTE_ORDER == BIG_ENDIAN)
  73     {
  74       static unsigned char big_break_insn[] = BIG_BREAKPOINT;
  75       *lenptr = sizeof (big_break_insn);
  76       return big_break_insn;
  77     }
  78 #endif
  79 #ifdef LITTLE_BREAKPOINT
  80   if (TARGET_BYTE_ORDER != BIG_ENDIAN)
  81     {
  82       static unsigned char little_break_insn[] = LITTLE_BREAKPOINT;
  83       *lenptr = sizeof (little_break_insn);
  84       return little_break_insn;
  85     }
  86 #endif
  87 #ifdef BREAKPOINT
  88   {
  89     static unsigned char break_insn[] = BREAKPOINT;
  90     *lenptr = sizeof (break_insn);
  91     return break_insn;
  92   }
  93 #endif
  94   *lenptr = 0;
  95   return NULL;
  96 }
  97
  98 int
  99 generic_frameless_function_invocation_not (struct frame_info *fi)
 100 {
 101   return 0;
 102 }
 103
 104 int
 105 generic_return_value_on_stack_not (struct type *type)
 106 {
 107   return 0;
 108 }
 109
 110 char *
 111 legacy_register_name (int i)
 112 {
 113 #ifdef REGISTER_NAMES
 114   static char *names[] = REGISTER_NAMES;
 115   if (i < 0 || i >= (sizeof (names) / sizeof (*names)))
 116     return NULL;
 117   else
 118     return names[i];
 119 #else
 120   internal_error ("legacy_register_name: called.");
 121   return NULL;
 122 #endif
 123 }
 124
 125 #if defined (CALL_DUMMY)
 126 LONGEST legacy_call_dummy_words[] = CALL_DUMMY;
 127 #else
 128 LONGEST legacy_call_dummy_words[1];
 129 #endif
 130 int legacy_sizeof_call_dummy_words = sizeof (legacy_call_dummy_words);
 131
 132 void
 133 generic_remote_translate_xfer_address (CORE_ADDR gdb_addr, int gdb_len,
 134                                        CORE_ADDR * rem_addr, int *rem_len)
 135 {
 136   *rem_addr = gdb_addr;
 137   *rem_len = gdb_len;
 138 }
 139
 140 int
 141 generic_prologue_frameless_p (CORE_ADDR ip)
 142 {
 143 #ifdef SKIP_PROLOGUE_FRAMELESS_P
 144   return ip == SKIP_PROLOGUE_FRAMELESS_P (ip);
 145 #else
 146   return ip == SKIP_PROLOGUE (ip);
 147 #endif
 148 }
 149
 150
 151 /* Helper functions for INNER_THAN */
 152
 153 int
 154 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
 155 {
 156   return (lhs < rhs);
 157 }
 158
 159 int
 160 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
 161 {
 162   return (lhs > rhs);
 163 }
 164
 165
 166 /* Helper functions for TARGET_{FLOAT,DOUBLE}_FORMAT */
 167
 168 const struct floatformat *
 169 default_float_format (struct gdbarch *gdbarch)
 170 {
 171 #if GDB_MULTI_ARCH
 172   int byte_order = gdbarch_byte_order (gdbarch);
 173 #else
 174   int byte_order = TARGET_BYTE_ORDER;
 175 #endif
 176   switch (byte_order)
 177     {
 178     case BIG_ENDIAN:
 179       return &floatformat_ieee_single_big;
 180     case LITTLE_ENDIAN:
 181       return &floatformat_ieee_single_little;
 182     default:
 183       internal_error ("default_float_format: bad byte order");
 184     }
 185 }
 186
 187
 188 const struct floatformat *
 189 default_double_format (struct gdbarch *gdbarch)
 190 {
 191 #if GDB_MULTI_ARCH
 192   int byte_order = gdbarch_byte_order (gdbarch);
 193 #else
 194   int byte_order = TARGET_BYTE_ORDER;
 195 #endif
 196   switch (byte_order)
 197     {
 198     case BIG_ENDIAN:
 199       return &floatformat_ieee_double_big;
 200     case LITTLE_ENDIAN:
 201       return &floatformat_ieee_double_little;
 202     default:
 203       internal_error ("default_double_format: bad byte order");
 204     }
 205 }
 206
 207 /* Misc helper functions for targets. */
 208
 209 int
 210 frame_num_args_unknown (struct frame_info *fi)
 211 {
 212   return -1;
 213 }
 214
 215
 216 int
 217 generic_register_convertible_not (int num)
 218 {
 219   return 0;
 220 }
 221
 222
 223 int
 224 default_register_sim_regno (int num)
 225 {
 226   return num;
 227 }
 228
 229 /* Functions to manipulate the endianness of the target.  */
 230
 231 #ifdef TARGET_BYTE_ORDER_SELECTABLE
 232 /* compat - Catch old targets that expect a selectable byte-order to
 233    default to BIG_ENDIAN */
 234 #ifndef TARGET_BYTE_ORDER_DEFAULT
 235 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN
 236 #endif
 237 #endif
 238 #if !TARGET_BYTE_ORDER_SELECTABLE_P
 239 #ifndef TARGET_BYTE_ORDER_DEFAULT
 240 /* compat - Catch old non byte-order selectable targets that do not
 241    define TARGET_BYTE_ORDER_DEFAULT and instead expect
 242    TARGET_BYTE_ORDER to be used as the default.  For targets that
 243    defined neither TARGET_BYTE_ORDER nor TARGET_BYTE_ORDER_DEFAULT the
 244    below will get a strange compiler warning. */
 245 #define TARGET_BYTE_ORDER_DEFAULT TARGET_BYTE_ORDER
 246 #endif
 247 #endif
 248 #ifndef TARGET_BYTE_ORDER_DEFAULT
 249 #define TARGET_BYTE_ORDER_DEFAULT BIG_ENDIAN /* arbitrary */
 250 #endif
 251 /* ``target_byte_order'' is only used when non- multi-arch.
 252    Multi-arch targets obtain the current byte order using
 253    TARGET_BYTE_ORDER which is controlled by gdbarch.*. */
 254 int target_byte_order = TARGET_BYTE_ORDER_DEFAULT;
 255 int target_byte_order_auto = 1;
 256
 257 static const char endian_big[] = "big";
 258 static const char endian_little[] = "little";
 259 static const char endian_auto[] = "auto";
 260 static const char *endian_enum[] =
 261 {
 262   endian_big,
 263   endian_little,
 264   endian_auto,
 265   NULL,
 266 };
 267 static const char *set_endian_string;
 268
 269 /* Called by ``show endian''.  */
 270
 271 static void
 272 show_endian (char *args, int from_tty)
 273 {
 274   if (TARGET_BYTE_ORDER_AUTO)
 275     printf_unfiltered ("The target endianness is set automatically (currently %s endian)\n",
 276                        (TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little"));
 277   else
 278     printf_unfiltered ("The target is assumed to be %s endian\n",
 279                        (TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little"));
 280 }
 281
 282 static void
 283 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
 284 {
 285   if (!TARGET_BYTE_ORDER_SELECTABLE_P)
 286     {
 287       printf_unfiltered ("Byte order is not selectable.");
 288     }
 289   else if (set_endian_string == endian_auto)
 290     {
 291       target_byte_order_auto = 1;
 292     }
 293   else if (set_endian_string == endian_little)
 294     {
 295       target_byte_order_auto = 0;
 296       if (GDB_MULTI_ARCH)
 297         {
 298           struct gdbarch_info info;
 299           memset (&info, 0, sizeof info);
 300           info.byte_order = LITTLE_ENDIAN;
 301           gdbarch_update (info);
 302         }
 303       else
 304         {
 305           target_byte_order = LITTLE_ENDIAN;
 306         }
 307     }
 308   else if (set_endian_string == endian_big)
 309     {
 310       target_byte_order_auto = 0;
 311       if (GDB_MULTI_ARCH)
 312         {
 313           struct gdbarch_info info;
 314           memset (&info, 0, sizeof info);
 315           info.byte_order = BIG_ENDIAN;
 316           gdbarch_update (info);
 317         }
 318       else
 319         {
 320           target_byte_order = BIG_ENDIAN;
 321         }
 322     }
 323   else
 324     internal_error ("set_endian: bad value");
 325   show_endian (NULL, from_tty);
 326 }
 327
 328 /* Set the endianness from a BFD.  */
 329
 330 static void
 331 set_endian_from_file (bfd *abfd)
 332 {
 333   if (GDB_MULTI_ARCH)
 334     internal_error ("set_endian_from_file: not for multi-arch");
 335   if (TARGET_BYTE_ORDER_SELECTABLE_P)
 336     {
 337       int want;
 338
 339       if (bfd_big_endian (abfd))
 340         want = BIG_ENDIAN;
 341       else
 342         want = LITTLE_ENDIAN;
 343       if (TARGET_BYTE_ORDER_AUTO)
 344         target_byte_order = want;
 345       else if (TARGET_BYTE_ORDER != want)
 346         warning ("%s endian file does not match %s endian target.",
 347                  want == BIG_ENDIAN ? "big" : "little",
 348                  TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little");
 349     }
 350   else
 351     {
 352       if (bfd_big_endian (abfd)
 353           ? TARGET_BYTE_ORDER != BIG_ENDIAN
 354           : TARGET_BYTE_ORDER == BIG_ENDIAN)
 355         warning ("%s endian file does not match %s endian target.",
 356                  bfd_big_endian (abfd) ? "big" : "little",
 357                  TARGET_BYTE_ORDER == BIG_ENDIAN ? "big" : "little");
 358     }
 359 }
 360
 361
 362 /* Functions to manipulate the architecture of the target */
 363
 364 enum set_arch { set_arch_auto, set_arch_manual };
 365
 366 int target_architecture_auto = 1;
 367
 368 const char *set_architecture_string;
 369
 370 /* Old way of changing the current architecture. */
 371
 372 extern const struct bfd_arch_info bfd_default_arch_struct;
 373 const struct bfd_arch_info *target_architecture = &bfd_default_arch_struct;
 374 int (*target_architecture_hook) (const struct bfd_arch_info *ap);
 375
 376 static int
 377 arch_ok (const struct bfd_arch_info *arch)
 378 {
 379   if (GDB_MULTI_ARCH)
 380     internal_error ("arch_ok: not multi-arched");
 381   /* Should be performing the more basic check that the binary is
 382      compatible with GDB. */
 383   /* Check with the target that the architecture is valid. */
 384   return (target_architecture_hook == NULL
 385           || target_architecture_hook (arch));
 386 }
 387
 388 static void
 389 set_arch (const struct bfd_arch_info *arch,
 390           enum set_arch type)
 391 {
 392   if (GDB_MULTI_ARCH)
 393     internal_error ("set_arch: not multi-arched");
 394   switch (type)
 395     {
 396     case set_arch_auto:
 397       if (!arch_ok (arch))
 398         warning ("Target may not support %s architecture",
 399                  arch->printable_name);
 400       target_architecture = arch;
 401       break;
 402     case set_arch_manual:
 403       if (!arch_ok (arch))
 404         {
 405           printf_unfiltered ("Target does not support `%s' architecture.\n",
 406                              arch->printable_name);
 407         }
 408       else
 409         {
 410           target_architecture_auto = 0;
 411           target_architecture = arch;
 412         }
 413       break;
 414     }
 415   if (gdbarch_debug)
 416     gdbarch_dump (current_gdbarch, gdb_stdlog);
 417 }
 418
 419 /* Set the architecture from arch/machine (deprecated) */
 420
 421 void
 422 set_architecture_from_arch_mach (enum bfd_architecture arch,
 423                                  unsigned long mach)
 424 {
 425   const struct bfd_arch_info *wanted = bfd_lookup_arch (arch, mach);
 426   if (GDB_MULTI_ARCH)
 427     internal_error ("set_architecture_from_arch_mach: not multi-arched");
 428   if (wanted != NULL)
 429     set_arch (wanted, set_arch_manual);
 430   else
 431     internal_error ("gdbarch: hardwired architecture/machine not reconized");
 432 }
 433
 434 /* Set the architecture from a BFD (deprecated) */
 435
 436 static void
 437 set_architecture_from_file (bfd *abfd)
 438 {
 439   const struct bfd_arch_info *wanted = bfd_get_arch_info (abfd);
 440   if (GDB_MULTI_ARCH)
 441     internal_error ("set_architecture_from_file: not multi-arched");
 442   if (target_architecture_auto)
 443     {
 444       set_arch (wanted, set_arch_auto);
 445     }
 446   else if (wanted != target_architecture)
 447     {
 448       warning ("%s architecture file may be incompatible with %s target.",
 449                wanted->printable_name,
 450                target_architecture->printable_name);
 451     }
 452 }
 453
 454
 455 /* Called if the user enters ``show architecture'' without an
 456    argument. */
 457
 458 static void
 459 show_architecture (char *args, int from_tty)
 460 {
 461   const char *arch;
 462   arch = TARGET_ARCHITECTURE->printable_name;
 463   if (target_architecture_auto)
 464     printf_filtered ("The target architecture is set automatically (currently %s)\n", arch);
 465   else
 466     printf_filtered ("The target architecture is assumed to be %s\n", arch);
 467 }
 468
 469
 470 /* Called if the user enters ``set architecture'' with or without an
 471    argument. */
 472
 473 static void
 474 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
 475 {
 476   if (strcmp (set_architecture_string, "auto") == 0)
 477     {
 478       target_architecture_auto = 1;
 479     }
 480   else if (GDB_MULTI_ARCH)
 481     {
 482       struct gdbarch_info info;
 483       memset (&info, 0, sizeof info);
 484       info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
 485       if (info.bfd_arch_info == NULL)
 486         internal_error ("set_architecture: bfd_scan_arch failed");
 487       if (gdbarch_update (info))
 488         target_architecture_auto = 0;
 489       else
 490         printf_unfiltered ("Architecture `%s' not reconized.\n",
 491                            set_architecture_string);
 492     }
 493   else
 494     {
 495       const struct bfd_arch_info *arch
 496         = bfd_scan_arch (set_architecture_string);
 497       if (arch == NULL)
 498         internal_error ("set_architecture: bfd_scan_arch failed");
 499       set_arch (arch, set_arch_manual);
 500     }
 501   show_architecture (NULL, from_tty);
 502 }
 503
 504 /* Called if the user enters ``info architecture'' without an argument. */
 505
 506 static void
 507 info_architecture (char *args, int from_tty)
 508 {
 509   printf_filtered ("Available architectures are:\n");
 510   if (GDB_MULTI_ARCH)
 511     {
 512       const char **arches = gdbarch_printable_names ();
 513       const char **arch;
 514       for (arch = arches; *arch != NULL; arch++)
 515         {
 516           printf_filtered (" %s", *arch);
 517         }
 518       free (arches);
 519     }
 520   else
 521     {
 522       enum bfd_architecture a;
 523       for (a = bfd_arch_obscure + 1; a < bfd_arch_last; a++)
 524         {
 525           const struct bfd_arch_info *ap;
 526           for (ap = bfd_lookup_arch (a, 0);
 527                ap != NULL;
 528                ap = ap->next)
 529             {
 530               printf_filtered (" %s", ap->printable_name);
 531               ap = ap->next;
 532             }
 533         }
 534     }
 535   printf_filtered ("\n");
 536 }
 537
 538 /* Set the dynamic target-system-dependant parameters (architecture,
 539    byte-order) using information found in the BFD */
 540
 541 void
 542 set_gdbarch_from_file (bfd *abfd)
 543 {
 544   if (GDB_MULTI_ARCH)
 545     {
 546       struct gdbarch_info info;
 547       memset (&info, 0, sizeof info);
 548       info.abfd = abfd;
 549       gdbarch_update (info);
 550     }
 551   else
 552     {
 553       set_architecture_from_file (abfd);
 554       set_endian_from_file (abfd);
 555     }
 556 }
 557
 558 /* Initialize the current architecture.  Update the ``set
 559    architecture'' command so that it specifies a list of valid
 560    architectures.  */
 561
 562 #ifdef DEFAULT_BFD_ARCH
 563 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
 564 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
 565 #else
 566 static const bfd_arch_info_type *default_bfd_arch;
 567 #endif
 568
 569 #ifdef DEFAULT_BFD_VEC
 570 extern const bfd_target DEFAULT_BFD_VEC;
 571 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
 572 #else
 573 static const bfd_target *default_bfd_vec;
 574 #endif
 575
 576 void
 577 initialize_current_architecture (void)
 578 {
 579   const char **arches = gdbarch_printable_names ();
 580
 581   /* determine a default architecture and byte order. */
 582   struct gdbarch_info info;
 583   memset (&info, 0, sizeof (info));
 584
 585   /* Find a default architecture. */
 586   if (info.bfd_arch_info == NULL
 587       && default_bfd_arch != NULL)
 588     info.bfd_arch_info = default_bfd_arch;
 589   if (info.bfd_arch_info == NULL)
 590     {
 591       /* Choose the architecture by taking the first one
 592          alphabetically. */
 593       const char *chosen = arches[0];
 594       const char **arch;
 595       for (arch = arches; *arch != NULL; arch++)
 596         {
 597           if (strcmp (*arch, chosen) < 0)
 598             chosen = *arch;
 599         }
 600       if (chosen == NULL)
 601         internal_error ("initialize_current_architecture: No arch");
 602       info.bfd_arch_info = bfd_scan_arch (chosen);
 603       if (info.bfd_arch_info == NULL)
 604         internal_error ("initialize_current_architecture: Arch not found");
 605     }
 606
 607   /* take several guesses at a byte order. */
 608   /* NB: can't use TARGET_BYTE_ORDER_DEFAULT as its definition is
 609      forced above. */
 610   if (info.byte_order == 0
 611       && default_bfd_vec != NULL)
 612     {
 613       /* Extract BFD's default vector's byte order. */
 614       switch (default_bfd_vec->byteorder)
 615         {
 616         case BFD_ENDIAN_BIG:
 617           info.byte_order = BIG_ENDIAN;
 618           break;
 619         case BFD_ENDIAN_LITTLE:
 620           info.byte_order = LITTLE_ENDIAN;
 621           break;
 622         default:
 623           break;
 624         }
 625     }
 626   if (info.byte_order == 0)
 627     {
 628       /* look for ``*el-*'' in the target name. */
 629       const char *chp;
 630       chp = strchr (target_name, '-');
 631       if (chp != NULL
 632           && chp - 2 >= target_name
 633           && strncmp (chp - 2, "el", 2) == 0)
 634         info.byte_order = LITTLE_ENDIAN;
 635     }
 636   if (info.byte_order == 0)
 637     {
 638       /* Wire it to big-endian!!! */
 639       info.byte_order = BIG_ENDIAN;
 640     }
 641
 642   if (GDB_MULTI_ARCH)
 643     {
 644       gdbarch_update (info);
 645     }
 646
 647   /* Create the ``set architecture'' command appending ``auto'' to the
 648      list of architectures. */
 649   {
 650     struct cmd_list_element *c;
 651     /* Append ``auto''. */
 652     int nr;
 653     for (nr = 0; arches[nr] != NULL; nr++);
 654     arches = xrealloc (arches, sizeof (char*) * (nr + 2));
 655     arches[nr + 0] = "auto";
 656     arches[nr + 1] = NULL;
 657     /* FIXME: add_set_enum_cmd() uses an array of ``char *'' instead
 658        of ``const char *''.  We just happen to know that the casts are
 659        safe. */
 660     c = add_set_enum_cmd ("architecture", class_support,
 661                           arches, &set_architecture_string,
 662                           "Set architecture of target.",
 663                           &setlist);
 664     c->function.sfunc = set_architecture;
 665     add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
 666     /* Don't use set_from_show - need to print both auto/manual and
 667        current setting. */
 668     add_cmd ("architecture", class_support, show_architecture,
 669              "Show the current target architecture", &showlist);
 670     c = add_cmd ("architecture", class_support, info_architecture,
 671                  "List supported target architectures", &infolist);
 672     deprecate_cmd (c, "set architecture");
 673   }
 674 }
 675
 676
 677 /* */
 678
 679 extern initialize_file_ftype _initialize_gdbarch_utils;
 680
 681 void
 682 _initialize_gdbarch_utils (void)
 683 {
 684   struct cmd_list_element *c;
 685   c = add_set_enum_cmd ("endian", class_support,
 686                         endian_enum, &set_endian_string,
 687                         "Set endianness of target.",
 688                         &setlist);
 689   c->function.sfunc = set_endian;
 690   /* Don't use set_from_show - need to print both auto/manual and
 691      current setting. */
 692   add_cmd ("endian", class_support, show_endian,
 693            "Show the current byte-order", &showlist);
 694 }