1 /* Dynamic architecture support for GDB, the GNU debugger.
3 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4 2008, 2009 Free Software Foundation, Inc.
6 This file is part of GDB.
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 3 of the License, or
11 (at your option) any later version.
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.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "arch-utils.h"
26 #include "inferior.h" /* enum CALL_DUMMY_LOCATION et.al. */
27 #include "gdb_string.h"
29 #include "gdb_assert.h"
30 #include "sim-regno.h"
33 #include "target-descriptions.h"
38 #include "floatformat.h"
41 struct displaced_step_closure *
42 simple_displaced_step_copy_insn (struct gdbarch *gdbarch,
43 CORE_ADDR from, CORE_ADDR to,
44 struct regcache *regs)
46 size_t len = gdbarch_max_insn_length (gdbarch);
47 gdb_byte *buf = xmalloc (len);
49 read_memory (from, buf, len);
50 write_memory (to, buf, len);
54 fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ",
55 paddress (gdbarch, from), paddress (gdbarch, to));
56 displaced_step_dump_bytes (gdb_stdlog, buf, len);
59 return (struct displaced_step_closure *) buf;
64 simple_displaced_step_free_closure (struct gdbarch *gdbarch,
65 struct displaced_step_closure *closure)
72 displaced_step_at_entry_point (struct gdbarch *gdbarch)
77 addr = entry_point_address ();
79 /* Inferior calls also use the entry point as a breakpoint location.
80 We don't want displaced stepping to interfere with those
81 breakpoints, so leave space. */
82 gdbarch_breakpoint_from_pc (gdbarch, &addr, &bp_len);
89 legacy_register_sim_regno (struct gdbarch *gdbarch, int regnum)
91 /* Only makes sense to supply raw registers. */
92 gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (gdbarch));
93 /* NOTE: cagney/2002-05-13: The old code did it this way and it is
94 suspected that some GDB/SIM combinations may rely on this
95 behavour. The default should be one2one_register_sim_regno
97 if (gdbarch_register_name (gdbarch, regnum) != NULL
98 && gdbarch_register_name (gdbarch, regnum)[0] != '\0')
101 return LEGACY_SIM_REGNO_IGNORE;
105 generic_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
111 generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
117 generic_in_solib_return_trampoline (struct gdbarch *gdbarch,
118 CORE_ADDR pc, char *name)
124 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
129 /* Helper functions for gdbarch_inner_than */
132 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
138 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
143 /* Misc helper functions for targets. */
146 core_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr)
152 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
153 struct target_ops *targ)
159 no_op_reg_to_regnum (struct gdbarch *gdbarch, int reg)
165 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
171 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
177 cannot_register_not (struct gdbarch *gdbarch, int regnum)
182 /* Legacy version of target_virtual_frame_pointer(). Assumes that
183 there is an gdbarch_deprecated_fp_regnum and that it is the same, cooked or
187 legacy_virtual_frame_pointer (struct gdbarch *gdbarch,
190 LONGEST *frame_offset)
192 /* FIXME: cagney/2002-09-13: This code is used when identifying the
193 frame pointer of the current PC. It is assuming that a single
194 register and an offset can determine this. I think it should
195 instead generate a byte code expression as that would work better
196 with things like Dwarf2's CFI. */
197 if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0
198 && gdbarch_deprecated_fp_regnum (gdbarch)
199 < gdbarch_num_regs (gdbarch))
200 *frame_regnum = gdbarch_deprecated_fp_regnum (gdbarch);
201 else if (gdbarch_sp_regnum (gdbarch) >= 0
202 && gdbarch_sp_regnum (gdbarch)
203 < gdbarch_num_regs (gdbarch))
204 *frame_regnum = gdbarch_sp_regnum (gdbarch);
206 /* Should this be an internal error? I guess so, it is reflecting
207 an architectural limitation in the current design. */
208 internal_error (__FILE__, __LINE__, _("No virtual frame pointer available"));
214 generic_convert_register_p (struct gdbarch *gdbarch, int regnum,
221 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
227 generic_instruction_nullified (struct gdbarch *gdbarch,
228 struct regcache *regcache)
234 default_remote_register_number (struct gdbarch *gdbarch,
241 /* Functions to manipulate the endianness of the target. */
243 static int target_byte_order_user = BFD_ENDIAN_UNKNOWN;
245 static const char endian_big[] = "big";
246 static const char endian_little[] = "little";
247 static const char endian_auto[] = "auto";
248 static const char *endian_enum[] =
255 static const char *set_endian_string;
258 selected_byte_order (void)
260 return target_byte_order_user;
263 /* Called by ``show endian''. */
266 show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c,
269 if (target_byte_order_user == BFD_ENDIAN_UNKNOWN)
270 if (gdbarch_byte_order (get_current_arch ()) == BFD_ENDIAN_BIG)
271 fprintf_unfiltered (file, _("The target endianness is set automatically "
272 "(currently big endian)\n"));
274 fprintf_unfiltered (file, _("The target endianness is set automatically "
275 "(currently little endian)\n"));
277 if (target_byte_order_user == BFD_ENDIAN_BIG)
278 fprintf_unfiltered (file,
279 _("The target is assumed to be big endian\n"));
281 fprintf_unfiltered (file,
282 _("The target is assumed to be little endian\n"));
286 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
288 struct gdbarch_info info;
290 gdbarch_info_init (&info);
292 if (set_endian_string == endian_auto)
294 target_byte_order_user = BFD_ENDIAN_UNKNOWN;
295 if (! gdbarch_update_p (info))
296 internal_error (__FILE__, __LINE__,
297 _("set_endian: architecture update failed"));
299 else if (set_endian_string == endian_little)
301 info.byte_order = BFD_ENDIAN_LITTLE;
302 if (! gdbarch_update_p (info))
303 printf_unfiltered (_("Little endian target not supported by GDB\n"));
305 target_byte_order_user = BFD_ENDIAN_LITTLE;
307 else if (set_endian_string == endian_big)
309 info.byte_order = BFD_ENDIAN_BIG;
310 if (! gdbarch_update_p (info))
311 printf_unfiltered (_("Big endian target not supported by GDB\n"));
313 target_byte_order_user = BFD_ENDIAN_BIG;
316 internal_error (__FILE__, __LINE__,
317 _("set_endian: bad value"));
319 show_endian (gdb_stdout, from_tty, NULL, NULL);
322 /* Given SELECTED, a currently selected BFD architecture, and
323 FROM_TARGET, a BFD architecture reported by the target description,
324 return what architecture to use. Either may be NULL; if both are
325 specified, we use the more specific. If the two are obviously
326 incompatible, warn the user. */
328 static const struct bfd_arch_info *
329 choose_architecture_for_target (const struct bfd_arch_info *selected,
330 const struct bfd_arch_info *from_target)
332 const struct bfd_arch_info *compat1, *compat2;
334 if (selected == NULL)
337 if (from_target == NULL)
340 /* struct bfd_arch_info objects are singletons: that is, there's
341 supposed to be exactly one instance for a given machine. So you
342 can tell whether two are equivalent by comparing pointers. */
343 if (from_target == selected)
346 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
347 incompatible. But if they are compatible, it returns the 'more
348 featureful' of the two arches. That is, if A can run code
349 written for B, but B can't run code written for A, then it'll
352 Some targets (e.g. MIPS as of 2006-12-04) don't fully
353 implement this, instead always returning NULL or the first
354 argument. We detect that case by checking both directions. */
356 compat1 = selected->compatible (selected, from_target);
357 compat2 = from_target->compatible (from_target, selected);
359 if (compat1 == NULL && compat2 == NULL)
361 warning (_("Selected architecture %s is not compatible "
362 "with reported target architecture %s"),
363 selected->printable_name, from_target->printable_name);
371 if (compat1 == compat2)
374 /* If the two didn't match, but one of them was a default architecture,
375 assume the more specific one is correct. This handles the case
376 where an executable or target description just says "mips", but
377 the other knows which MIPS variant. */
378 if (compat1->the_default)
380 if (compat2->the_default)
383 /* We have no idea which one is better. This is a bug, but not
384 a critical problem; warn the user. */
385 warning (_("Selected architecture %s is ambiguous with "
386 "reported target architecture %s"),
387 selected->printable_name, from_target->printable_name);
391 /* Functions to manipulate the architecture of the target */
393 enum set_arch { set_arch_auto, set_arch_manual };
395 static const struct bfd_arch_info *target_architecture_user;
397 static const char *set_architecture_string;
400 selected_architecture_name (void)
402 if (target_architecture_user == NULL)
405 return set_architecture_string;
408 /* Called if the user enters ``show architecture'' without an
412 show_architecture (struct ui_file *file, int from_tty,
413 struct cmd_list_element *c, const char *value)
415 if (target_architecture_user == NULL)
416 fprintf_filtered (file, _("\
417 The target architecture is set automatically (currently %s)\n"),
418 gdbarch_bfd_arch_info (get_current_arch ())->printable_name);
420 fprintf_filtered (file, _("\
421 The target architecture is assumed to be %s\n"), set_architecture_string);
425 /* Called if the user enters ``set architecture'' with or without an
429 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
431 struct gdbarch_info info;
433 gdbarch_info_init (&info);
435 if (strcmp (set_architecture_string, "auto") == 0)
437 target_architecture_user = NULL;
438 if (!gdbarch_update_p (info))
439 internal_error (__FILE__, __LINE__,
440 _("could not select an architecture automatically"));
444 info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
445 if (info.bfd_arch_info == NULL)
446 internal_error (__FILE__, __LINE__,
447 _("set_architecture: bfd_scan_arch failed"));
448 if (gdbarch_update_p (info))
449 target_architecture_user = info.bfd_arch_info;
451 printf_unfiltered (_("Architecture `%s' not recognized.\n"),
452 set_architecture_string);
454 show_architecture (gdb_stdout, from_tty, NULL, NULL);
457 /* Try to select a global architecture that matches "info". Return
458 non-zero if the attempt succeds. */
460 gdbarch_update_p (struct gdbarch_info info)
462 struct gdbarch *new_gdbarch;
464 /* Check for the current file. */
465 if (info.abfd == NULL)
466 info.abfd = exec_bfd;
467 if (info.abfd == NULL)
468 info.abfd = core_bfd;
470 /* Check for the current target description. */
471 if (info.target_desc == NULL)
472 info.target_desc = target_current_description ();
474 new_gdbarch = gdbarch_find_by_info (info);
476 /* If there no architecture by that name, reject the request. */
477 if (new_gdbarch == NULL)
480 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
481 "Architecture not found\n");
485 /* If it is the same old architecture, accept the request (but don't
487 if (new_gdbarch == target_gdbarch)
490 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
491 "Architecture %s (%s) unchanged\n",
492 host_address_to_string (new_gdbarch),
493 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
497 /* It's a new architecture, swap it in. */
499 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
500 "New architecture %s (%s) selected\n",
501 host_address_to_string (new_gdbarch),
502 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
503 deprecated_target_gdbarch_select_hack (new_gdbarch);
508 /* Return the architecture for ABFD. If no suitable architecture
509 could be find, return NULL. */
512 gdbarch_from_bfd (bfd *abfd)
514 struct gdbarch_info info;
515 gdbarch_info_init (&info);
517 return gdbarch_find_by_info (info);
520 /* Set the dynamic target-system-dependent parameters (architecture,
521 byte-order) using information found in the BFD */
524 set_gdbarch_from_file (bfd *abfd)
526 struct gdbarch_info info;
527 struct gdbarch *gdbarch;
529 gdbarch_info_init (&info);
531 info.target_desc = target_current_description ();
532 gdbarch = gdbarch_find_by_info (info);
535 error (_("Architecture of file not recognized."));
536 deprecated_target_gdbarch_select_hack (gdbarch);
539 /* Initialize the current architecture. Update the ``set
540 architecture'' command so that it specifies a list of valid
543 #ifdef DEFAULT_BFD_ARCH
544 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
545 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
547 static const bfd_arch_info_type *default_bfd_arch;
550 #ifdef DEFAULT_BFD_VEC
551 extern const bfd_target DEFAULT_BFD_VEC;
552 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
554 static const bfd_target *default_bfd_vec;
557 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
560 initialize_current_architecture (void)
562 const char **arches = gdbarch_printable_names ();
564 /* determine a default architecture and byte order. */
565 struct gdbarch_info info;
566 gdbarch_info_init (&info);
568 /* Find a default architecture. */
569 if (default_bfd_arch == NULL)
571 /* Choose the architecture by taking the first one
573 const char *chosen = arches[0];
575 for (arch = arches; *arch != NULL; arch++)
577 if (strcmp (*arch, chosen) < 0)
581 internal_error (__FILE__, __LINE__,
582 _("initialize_current_architecture: No arch"));
583 default_bfd_arch = bfd_scan_arch (chosen);
584 if (default_bfd_arch == NULL)
585 internal_error (__FILE__, __LINE__,
586 _("initialize_current_architecture: Arch not found"));
589 info.bfd_arch_info = default_bfd_arch;
591 /* Take several guesses at a byte order. */
592 if (default_byte_order == BFD_ENDIAN_UNKNOWN
593 && default_bfd_vec != NULL)
595 /* Extract BFD's default vector's byte order. */
596 switch (default_bfd_vec->byteorder)
599 default_byte_order = BFD_ENDIAN_BIG;
601 case BFD_ENDIAN_LITTLE:
602 default_byte_order = BFD_ENDIAN_LITTLE;
608 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
610 /* look for ``*el-*'' in the target name. */
612 chp = strchr (target_name, '-');
614 && chp - 2 >= target_name
615 && strncmp (chp - 2, "el", 2) == 0)
616 default_byte_order = BFD_ENDIAN_LITTLE;
618 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
620 /* Wire it to big-endian!!! */
621 default_byte_order = BFD_ENDIAN_BIG;
624 info.byte_order = default_byte_order;
625 info.byte_order_for_code = info.byte_order;
627 if (! gdbarch_update_p (info))
628 internal_error (__FILE__, __LINE__,
629 _("initialize_current_architecture: Selection of "
630 "initial architecture failed"));
632 /* Create the ``set architecture'' command appending ``auto'' to the
633 list of architectures. */
635 struct cmd_list_element *c;
636 /* Append ``auto''. */
638 for (nr = 0; arches[nr] != NULL; nr++);
639 arches = xrealloc (arches, sizeof (char*) * (nr + 2));
640 arches[nr + 0] = "auto";
641 arches[nr + 1] = NULL;
642 add_setshow_enum_cmd ("architecture", class_support,
643 arches, &set_architecture_string, _("\
644 Set architecture of target."), _("\
645 Show architecture of target."), NULL,
646 set_architecture, show_architecture,
647 &setlist, &showlist);
648 add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
653 /* Initialize a gdbarch info to values that will be automatically
654 overridden. Note: Originally, this ``struct info'' was initialized
655 using memset(0). Unfortunately, that ran into problems, namely
656 BFD_ENDIAN_BIG is zero. An explicit initialization function that
657 can explicitly set each field to a well defined value is used. */
660 gdbarch_info_init (struct gdbarch_info *info)
662 memset (info, 0, sizeof (struct gdbarch_info));
663 info->byte_order = BFD_ENDIAN_UNKNOWN;
664 info->byte_order_for_code = info->byte_order;
665 info->osabi = GDB_OSABI_UNINITIALIZED;
668 /* Similar to init, but this time fill in the blanks. Information is
669 obtained from the global "set ..." options and explicitly
670 initialized INFO fields. */
673 gdbarch_info_fill (struct gdbarch_info *info)
675 /* "(gdb) set architecture ...". */
676 if (info->bfd_arch_info == NULL
677 && target_architecture_user)
678 info->bfd_arch_info = target_architecture_user;
680 if (info->bfd_arch_info == NULL
681 && info->abfd != NULL
682 && bfd_get_arch (info->abfd) != bfd_arch_unknown
683 && bfd_get_arch (info->abfd) != bfd_arch_obscure)
684 info->bfd_arch_info = bfd_get_arch_info (info->abfd);
685 /* From the target. */
686 if (info->target_desc != NULL)
687 info->bfd_arch_info = choose_architecture_for_target
688 (info->bfd_arch_info, tdesc_architecture (info->target_desc));
689 /* From the default. */
690 if (info->bfd_arch_info == NULL)
691 info->bfd_arch_info = default_bfd_arch;
693 /* "(gdb) set byte-order ...". */
694 if (info->byte_order == BFD_ENDIAN_UNKNOWN
695 && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
696 info->byte_order = target_byte_order_user;
697 /* From the INFO struct. */
698 if (info->byte_order == BFD_ENDIAN_UNKNOWN
699 && info->abfd != NULL)
700 info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
701 : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
702 : BFD_ENDIAN_UNKNOWN);
703 /* From the default. */
704 if (info->byte_order == BFD_ENDIAN_UNKNOWN)
705 info->byte_order = default_byte_order;
706 info->byte_order_for_code = info->byte_order;
708 /* "(gdb) set osabi ...". Handled by gdbarch_lookup_osabi. */
709 /* From the manual override, or from file. */
710 if (info->osabi == GDB_OSABI_UNINITIALIZED)
711 info->osabi = gdbarch_lookup_osabi (info->abfd);
712 /* From the target. */
713 if (info->osabi == GDB_OSABI_UNKNOWN && info->target_desc != NULL)
714 info->osabi = tdesc_osabi (info->target_desc);
715 /* From the configured default. */
716 #ifdef GDB_OSABI_DEFAULT
717 if (info->osabi == GDB_OSABI_UNKNOWN)
718 info->osabi = GDB_OSABI_DEFAULT;
721 /* Must have at least filled in the architecture. */
722 gdb_assert (info->bfd_arch_info != NULL);
725 /* Return "current" architecture. If the target is running, this is the
726 architecture of the selected frame. Otherwise, the "current" architecture
727 defaults to the target architecture.
729 This function should normally be called solely by the command interpreter
730 routines to determine the architecture to execute a command in. */
732 get_current_arch (void)
734 if (has_stack_frames ())
735 return get_frame_arch (get_selected_frame (NULL));
737 return target_gdbarch;
742 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
745 _initialize_gdbarch_utils (void)
747 struct cmd_list_element *c;
748 add_setshow_enum_cmd ("endian", class_support,
749 endian_enum, &set_endian_string, _("\
750 Set endianness of target."), _("\
751 Show endianness of target."), NULL,
752 set_endian, show_endian,
753 &setlist, &showlist);