1 /* Dynamic architecture support for GDB, the GNU debugger.
3 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
4 2008 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 0x%s->0x%s: ",
55 paddr_nz (from), paddr_nz (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 /* Make certain that the address points at real code, and not a
80 function descriptor. */
81 addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, ¤t_target);
83 /* Inferior calls also use the entry point as a breakpoint location.
84 We don't want displaced stepping to interfere with those
85 breakpoints, so leave space. */
86 gdbarch_breakpoint_from_pc (gdbarch, &addr, &bp_len);
93 legacy_register_sim_regno (struct gdbarch *gdbarch, int regnum)
95 /* Only makes sense to supply raw registers. */
96 gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (gdbarch));
97 /* NOTE: cagney/2002-05-13: The old code did it this way and it is
98 suspected that some GDB/SIM combinations may rely on this
99 behavour. The default should be one2one_register_sim_regno
101 if (gdbarch_register_name (gdbarch, regnum) != NULL
102 && gdbarch_register_name (gdbarch, regnum)[0] != '\0')
105 return LEGACY_SIM_REGNO_IGNORE;
109 generic_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
115 generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
121 generic_in_solib_return_trampoline (CORE_ADDR pc, char *name)
127 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
132 /* Helper functions for gdbarch_inner_than */
135 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
141 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
146 /* Misc helper functions for targets. */
149 core_addr_identity (CORE_ADDR addr)
155 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
156 struct target_ops *targ)
162 no_op_reg_to_regnum (struct gdbarch *gdbarch, int reg)
168 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
174 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
180 cannot_register_not (struct gdbarch *gdbarch, int regnum)
185 /* Legacy version of target_virtual_frame_pointer(). Assumes that
186 there is an gdbarch_deprecated_fp_regnum and that it is the same, cooked or
190 legacy_virtual_frame_pointer (struct gdbarch *gdbarch,
193 LONGEST *frame_offset)
195 /* FIXME: cagney/2002-09-13: This code is used when identifying the
196 frame pointer of the current PC. It is assuming that a single
197 register and an offset can determine this. I think it should
198 instead generate a byte code expression as that would work better
199 with things like Dwarf2's CFI. */
200 if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0
201 && gdbarch_deprecated_fp_regnum (gdbarch)
202 < gdbarch_num_regs (gdbarch))
203 *frame_regnum = gdbarch_deprecated_fp_regnum (gdbarch);
204 else if (gdbarch_sp_regnum (gdbarch) >= 0
205 && gdbarch_sp_regnum (gdbarch)
206 < gdbarch_num_regs (gdbarch))
207 *frame_regnum = gdbarch_sp_regnum (gdbarch);
209 /* Should this be an internal error? I guess so, it is reflecting
210 an architectural limitation in the current design. */
211 internal_error (__FILE__, __LINE__, _("No virtual frame pointer available"));
217 generic_convert_register_p (struct gdbarch *gdbarch, int regnum,
224 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
230 generic_instruction_nullified (struct gdbarch *gdbarch,
231 struct regcache *regcache)
237 default_remote_register_number (struct gdbarch *gdbarch,
244 /* Functions to manipulate the endianness of the target. */
246 static int target_byte_order_user = BFD_ENDIAN_UNKNOWN;
248 static const char endian_big[] = "big";
249 static const char endian_little[] = "little";
250 static const char endian_auto[] = "auto";
251 static const char *endian_enum[] =
258 static const char *set_endian_string;
261 selected_byte_order (void)
263 if (target_byte_order_user != BFD_ENDIAN_UNKNOWN)
264 return gdbarch_byte_order (current_gdbarch);
266 return BFD_ENDIAN_UNKNOWN;
269 /* Called by ``show endian''. */
272 show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c,
275 if (target_byte_order_user == BFD_ENDIAN_UNKNOWN)
276 if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
277 fprintf_unfiltered (file, _("The target endianness is set automatically "
278 "(currently big endian)\n"));
280 fprintf_unfiltered (file, _("The target endianness is set automatically "
281 "(currently little endian)\n"));
283 if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
284 fprintf_unfiltered (file,
285 _("The target is assumed to be big endian\n"));
287 fprintf_unfiltered (file,
288 _("The target is assumed to be little endian\n"));
292 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
294 struct gdbarch_info info;
296 gdbarch_info_init (&info);
298 if (set_endian_string == endian_auto)
300 target_byte_order_user = BFD_ENDIAN_UNKNOWN;
301 if (! gdbarch_update_p (info))
302 internal_error (__FILE__, __LINE__,
303 _("set_endian: architecture update failed"));
305 else if (set_endian_string == endian_little)
307 info.byte_order = BFD_ENDIAN_LITTLE;
308 if (! gdbarch_update_p (info))
309 printf_unfiltered (_("Little endian target not supported by GDB\n"));
311 target_byte_order_user = BFD_ENDIAN_LITTLE;
313 else if (set_endian_string == endian_big)
315 info.byte_order = BFD_ENDIAN_BIG;
316 if (! gdbarch_update_p (info))
317 printf_unfiltered (_("Big endian target not supported by GDB\n"));
319 target_byte_order_user = BFD_ENDIAN_BIG;
322 internal_error (__FILE__, __LINE__,
323 _("set_endian: bad value"));
325 show_endian (gdb_stdout, from_tty, NULL, NULL);
328 /* Given SELECTED, a currently selected BFD architecture, and
329 FROM_TARGET, a BFD architecture reported by the target description,
330 return what architecture to use. Either may be NULL; if both are
331 specified, we use the more specific. If the two are obviously
332 incompatible, warn the user. */
334 static const struct bfd_arch_info *
335 choose_architecture_for_target (const struct bfd_arch_info *selected,
336 const struct bfd_arch_info *from_target)
338 const struct bfd_arch_info *compat1, *compat2;
340 if (selected == NULL)
343 if (from_target == NULL)
346 /* struct bfd_arch_info objects are singletons: that is, there's
347 supposed to be exactly one instance for a given machine. So you
348 can tell whether two are equivalent by comparing pointers. */
349 if (from_target == selected)
352 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
353 incompatible. But if they are compatible, it returns the 'more
354 featureful' of the two arches. That is, if A can run code
355 written for B, but B can't run code written for A, then it'll
358 Some targets (e.g. MIPS as of 2006-12-04) don't fully
359 implement this, instead always returning NULL or the first
360 argument. We detect that case by checking both directions. */
362 compat1 = selected->compatible (selected, from_target);
363 compat2 = from_target->compatible (from_target, selected);
365 if (compat1 == NULL && compat2 == NULL)
367 warning (_("Selected architecture %s is not compatible "
368 "with reported target architecture %s"),
369 selected->printable_name, from_target->printable_name);
377 if (compat1 == compat2)
380 /* If the two didn't match, but one of them was a default architecture,
381 assume the more specific one is correct. This handles the case
382 where an executable or target description just says "mips", but
383 the other knows which MIPS variant. */
384 if (compat1->the_default)
386 if (compat2->the_default)
389 /* We have no idea which one is better. This is a bug, but not
390 a critical problem; warn the user. */
391 warning (_("Selected architecture %s is ambiguous with "
392 "reported target architecture %s"),
393 selected->printable_name, from_target->printable_name);
397 /* Functions to manipulate the architecture of the target */
399 enum set_arch { set_arch_auto, set_arch_manual };
401 static const struct bfd_arch_info *target_architecture_user;
403 static const char *set_architecture_string;
406 selected_architecture_name (void)
408 if (target_architecture_user == NULL)
411 return set_architecture_string;
414 /* Called if the user enters ``show architecture'' without an
418 show_architecture (struct ui_file *file, int from_tty,
419 struct cmd_list_element *c, const char *value)
422 arch = gdbarch_bfd_arch_info (current_gdbarch)->printable_name;
423 if (target_architecture_user == NULL)
424 fprintf_filtered (file, _("\
425 The target architecture is set automatically (currently %s)\n"), arch);
427 fprintf_filtered (file, _("\
428 The target architecture is assumed to be %s\n"), arch);
432 /* Called if the user enters ``set architecture'' with or without an
436 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
438 struct gdbarch_info info;
440 gdbarch_info_init (&info);
442 if (strcmp (set_architecture_string, "auto") == 0)
444 target_architecture_user = NULL;
445 if (!gdbarch_update_p (info))
446 internal_error (__FILE__, __LINE__,
447 _("could not select an architecture automatically"));
451 info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
452 if (info.bfd_arch_info == NULL)
453 internal_error (__FILE__, __LINE__,
454 _("set_architecture: bfd_scan_arch failed"));
455 if (gdbarch_update_p (info))
456 target_architecture_user = info.bfd_arch_info;
458 printf_unfiltered (_("Architecture `%s' not recognized.\n"),
459 set_architecture_string);
461 show_architecture (gdb_stdout, from_tty, NULL, NULL);
464 /* Try to select a global architecture that matches "info". Return
465 non-zero if the attempt succeds. */
467 gdbarch_update_p (struct gdbarch_info info)
469 struct gdbarch *new_gdbarch;
471 /* Check for the current file. */
472 if (info.abfd == NULL)
473 info.abfd = exec_bfd;
474 if (info.abfd == NULL)
475 info.abfd = core_bfd;
477 /* Check for the current target description. */
478 if (info.target_desc == NULL)
479 info.target_desc = target_current_description ();
481 new_gdbarch = gdbarch_find_by_info (info);
483 /* If there no architecture by that name, reject the request. */
484 if (new_gdbarch == NULL)
487 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
488 "Architecture not found\n");
492 /* If it is the same old architecture, accept the request (but don't
494 if (new_gdbarch == current_gdbarch)
497 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
498 "Architecture 0x%08lx (%s) unchanged\n",
500 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
504 /* It's a new architecture, swap it in. */
506 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
507 "New architecture 0x%08lx (%s) selected\n",
509 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
510 deprecated_current_gdbarch_select_hack (new_gdbarch);
515 /* Return the architecture for ABFD. If no suitable architecture
516 could be find, return NULL. */
519 gdbarch_from_bfd (bfd *abfd)
521 struct gdbarch_info info;
522 gdbarch_info_init (&info);
524 return gdbarch_find_by_info (info);
527 /* Set the dynamic target-system-dependent parameters (architecture,
528 byte-order) using information found in the BFD */
531 set_gdbarch_from_file (bfd *abfd)
533 struct gdbarch_info info;
534 struct gdbarch *gdbarch;
536 gdbarch_info_init (&info);
538 info.target_desc = target_current_description ();
539 gdbarch = gdbarch_find_by_info (info);
542 error (_("Architecture of file not recognized."));
543 deprecated_current_gdbarch_select_hack (gdbarch);
546 /* Initialize the current architecture. Update the ``set
547 architecture'' command so that it specifies a list of valid
550 #ifdef DEFAULT_BFD_ARCH
551 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
552 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
554 static const bfd_arch_info_type *default_bfd_arch;
557 #ifdef DEFAULT_BFD_VEC
558 extern const bfd_target DEFAULT_BFD_VEC;
559 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
561 static const bfd_target *default_bfd_vec;
564 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
567 initialize_current_architecture (void)
569 const char **arches = gdbarch_printable_names ();
571 /* determine a default architecture and byte order. */
572 struct gdbarch_info info;
573 gdbarch_info_init (&info);
575 /* Find a default architecture. */
576 if (default_bfd_arch == NULL)
578 /* Choose the architecture by taking the first one
580 const char *chosen = arches[0];
582 for (arch = arches; *arch != NULL; arch++)
584 if (strcmp (*arch, chosen) < 0)
588 internal_error (__FILE__, __LINE__,
589 _("initialize_current_architecture: No arch"));
590 default_bfd_arch = bfd_scan_arch (chosen);
591 if (default_bfd_arch == NULL)
592 internal_error (__FILE__, __LINE__,
593 _("initialize_current_architecture: Arch not found"));
596 info.bfd_arch_info = default_bfd_arch;
598 /* Take several guesses at a byte order. */
599 if (default_byte_order == BFD_ENDIAN_UNKNOWN
600 && default_bfd_vec != NULL)
602 /* Extract BFD's default vector's byte order. */
603 switch (default_bfd_vec->byteorder)
606 default_byte_order = BFD_ENDIAN_BIG;
608 case BFD_ENDIAN_LITTLE:
609 default_byte_order = BFD_ENDIAN_LITTLE;
615 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
617 /* look for ``*el-*'' in the target name. */
619 chp = strchr (target_name, '-');
621 && chp - 2 >= target_name
622 && strncmp (chp - 2, "el", 2) == 0)
623 default_byte_order = BFD_ENDIAN_LITTLE;
625 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
627 /* Wire it to big-endian!!! */
628 default_byte_order = BFD_ENDIAN_BIG;
631 info.byte_order = default_byte_order;
633 if (! gdbarch_update_p (info))
634 internal_error (__FILE__, __LINE__,
635 _("initialize_current_architecture: Selection of "
636 "initial architecture failed"));
638 /* Create the ``set architecture'' command appending ``auto'' to the
639 list of architectures. */
641 struct cmd_list_element *c;
642 /* Append ``auto''. */
644 for (nr = 0; arches[nr] != NULL; nr++);
645 arches = xrealloc (arches, sizeof (char*) * (nr + 2));
646 arches[nr + 0] = "auto";
647 arches[nr + 1] = NULL;
648 add_setshow_enum_cmd ("architecture", class_support,
649 arches, &set_architecture_string, _("\
650 Set architecture of target."), _("\
651 Show architecture of target."), NULL,
652 set_architecture, show_architecture,
653 &setlist, &showlist);
654 add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
659 /* Initialize a gdbarch info to values that will be automatically
660 overridden. Note: Originally, this ``struct info'' was initialized
661 using memset(0). Unfortunately, that ran into problems, namely
662 BFD_ENDIAN_BIG is zero. An explicit initialization function that
663 can explicitly set each field to a well defined value is used. */
666 gdbarch_info_init (struct gdbarch_info *info)
668 memset (info, 0, sizeof (struct gdbarch_info));
669 info->byte_order = BFD_ENDIAN_UNKNOWN;
670 info->osabi = GDB_OSABI_UNINITIALIZED;
673 /* Similar to init, but this time fill in the blanks. Information is
674 obtained from the global "set ..." options and explicitly
675 initialized INFO fields. */
678 gdbarch_info_fill (struct gdbarch_info *info)
680 /* "(gdb) set architecture ...". */
681 if (info->bfd_arch_info == NULL
682 && target_architecture_user)
683 info->bfd_arch_info = target_architecture_user;
685 if (info->bfd_arch_info == NULL
686 && info->abfd != NULL
687 && bfd_get_arch (info->abfd) != bfd_arch_unknown
688 && bfd_get_arch (info->abfd) != bfd_arch_obscure)
689 info->bfd_arch_info = bfd_get_arch_info (info->abfd);
690 /* From the target. */
691 if (info->target_desc != NULL)
692 info->bfd_arch_info = choose_architecture_for_target
693 (info->bfd_arch_info, tdesc_architecture (info->target_desc));
694 /* From the default. */
695 if (info->bfd_arch_info == NULL)
696 info->bfd_arch_info = default_bfd_arch;
698 /* "(gdb) set byte-order ...". */
699 if (info->byte_order == BFD_ENDIAN_UNKNOWN
700 && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
701 info->byte_order = target_byte_order_user;
702 /* From the INFO struct. */
703 if (info->byte_order == BFD_ENDIAN_UNKNOWN
704 && info->abfd != NULL)
705 info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
706 : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
707 : BFD_ENDIAN_UNKNOWN);
708 /* From the default. */
709 if (info->byte_order == BFD_ENDIAN_UNKNOWN)
710 info->byte_order = default_byte_order;
712 /* "(gdb) set osabi ...". Handled by gdbarch_lookup_osabi. */
713 if (info->osabi == GDB_OSABI_UNINITIALIZED)
714 info->osabi = gdbarch_lookup_osabi (info->abfd);
716 /* Must have at least filled in the architecture. */
717 gdb_assert (info->bfd_arch_info != NULL);
722 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
725 _initialize_gdbarch_utils (void)
727 struct cmd_list_element *c;
728 add_setshow_enum_cmd ("endian", class_support,
729 endian_enum, &set_endian_string, _("\
730 Set endianness of target."), _("\
731 Show endianness of target."), NULL,
732 set_endian, show_endian,
733 &setlist, &showlist);