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 = gdbarch_find_by_info (info);
471 /* If there no architecture by that name, reject the request. */
472 if (new_gdbarch == NULL)
475 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
476 "Architecture not found\n");
480 /* If it is the same old architecture, accept the request (but don't
482 if (new_gdbarch == current_gdbarch)
485 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
486 "Architecture 0x%08lx (%s) unchanged\n",
488 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
492 /* It's a new architecture, swap it in. */
494 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
495 "New architecture 0x%08lx (%s) selected\n",
497 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
498 deprecated_current_gdbarch_select_hack (new_gdbarch);
503 /* Return the architecture for ABFD. If no suitable architecture
504 could be find, return NULL. */
507 gdbarch_from_bfd (bfd *abfd)
509 struct gdbarch_info info;
511 /* If we call gdbarch_find_by_info without filling in info.abfd,
512 then it will use the global exec_bfd. That's fine if we don't
513 have one of those either. And that's the only time we should
514 reach here with a NULL ABFD argument - when we are discarding
516 gdb_assert (abfd != NULL || exec_bfd == NULL);
518 gdbarch_info_init (&info);
520 return gdbarch_find_by_info (info);
523 /* Set the dynamic target-system-dependent parameters (architecture,
524 byte-order) using information found in the BFD */
527 set_gdbarch_from_file (bfd *abfd)
529 struct gdbarch *gdbarch;
531 gdbarch = gdbarch_from_bfd (abfd);
533 error (_("Architecture of file not recognized."));
534 deprecated_current_gdbarch_select_hack (gdbarch);
537 /* Initialize the current architecture. Update the ``set
538 architecture'' command so that it specifies a list of valid
541 #ifdef DEFAULT_BFD_ARCH
542 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
543 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
545 static const bfd_arch_info_type *default_bfd_arch;
548 #ifdef DEFAULT_BFD_VEC
549 extern const bfd_target DEFAULT_BFD_VEC;
550 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
552 static const bfd_target *default_bfd_vec;
555 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
558 initialize_current_architecture (void)
560 const char **arches = gdbarch_printable_names ();
562 /* determine a default architecture and byte order. */
563 struct gdbarch_info info;
564 gdbarch_info_init (&info);
566 /* Find a default architecture. */
567 if (default_bfd_arch == NULL)
569 /* Choose the architecture by taking the first one
571 const char *chosen = arches[0];
573 for (arch = arches; *arch != NULL; arch++)
575 if (strcmp (*arch, chosen) < 0)
579 internal_error (__FILE__, __LINE__,
580 _("initialize_current_architecture: No arch"));
581 default_bfd_arch = bfd_scan_arch (chosen);
582 if (default_bfd_arch == NULL)
583 internal_error (__FILE__, __LINE__,
584 _("initialize_current_architecture: Arch not found"));
587 info.bfd_arch_info = default_bfd_arch;
589 /* Take several guesses at a byte order. */
590 if (default_byte_order == BFD_ENDIAN_UNKNOWN
591 && default_bfd_vec != NULL)
593 /* Extract BFD's default vector's byte order. */
594 switch (default_bfd_vec->byteorder)
597 default_byte_order = BFD_ENDIAN_BIG;
599 case BFD_ENDIAN_LITTLE:
600 default_byte_order = BFD_ENDIAN_LITTLE;
606 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
608 /* look for ``*el-*'' in the target name. */
610 chp = strchr (target_name, '-');
612 && chp - 2 >= target_name
613 && strncmp (chp - 2, "el", 2) == 0)
614 default_byte_order = BFD_ENDIAN_LITTLE;
616 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
618 /* Wire it to big-endian!!! */
619 default_byte_order = BFD_ENDIAN_BIG;
622 info.byte_order = default_byte_order;
624 if (! gdbarch_update_p (info))
625 internal_error (__FILE__, __LINE__,
626 _("initialize_current_architecture: Selection of "
627 "initial architecture failed"));
629 /* Create the ``set architecture'' command appending ``auto'' to the
630 list of architectures. */
632 struct cmd_list_element *c;
633 /* Append ``auto''. */
635 for (nr = 0; arches[nr] != NULL; nr++);
636 arches = xrealloc (arches, sizeof (char*) * (nr + 2));
637 arches[nr + 0] = "auto";
638 arches[nr + 1] = NULL;
639 add_setshow_enum_cmd ("architecture", class_support,
640 arches, &set_architecture_string, _("\
641 Set architecture of target."), _("\
642 Show architecture of target."), NULL,
643 set_architecture, show_architecture,
644 &setlist, &showlist);
645 add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
650 /* Initialize a gdbarch info to values that will be automatically
651 overridden. Note: Originally, this ``struct info'' was initialized
652 using memset(0). Unfortunately, that ran into problems, namely
653 BFD_ENDIAN_BIG is zero. An explicit initialization function that
654 can explicitly set each field to a well defined value is used. */
657 gdbarch_info_init (struct gdbarch_info *info)
659 memset (info, 0, sizeof (struct gdbarch_info));
660 info->byte_order = BFD_ENDIAN_UNKNOWN;
661 info->osabi = GDB_OSABI_UNINITIALIZED;
664 /* Similar to init, but this time fill in the blanks. Information is
665 obtained from the global "set ..." options and explicitly
666 initialized INFO fields. */
669 gdbarch_info_fill (struct gdbarch_info *info)
671 /* Check for the current file. */
672 if (info->abfd == NULL)
673 info->abfd = exec_bfd;
674 if (info->abfd == NULL)
675 info->abfd = core_bfd;
677 /* Check for the current target description. */
678 if (info->target_desc == NULL)
679 info->target_desc = target_current_description ();
681 /* "(gdb) set architecture ...". */
682 if (info->bfd_arch_info == NULL
683 && target_architecture_user)
684 info->bfd_arch_info = target_architecture_user;
686 if (info->bfd_arch_info == NULL
687 && info->abfd != NULL
688 && bfd_get_arch (info->abfd) != bfd_arch_unknown
689 && bfd_get_arch (info->abfd) != bfd_arch_obscure)
690 info->bfd_arch_info = bfd_get_arch_info (info->abfd);
691 /* From the target. */
692 if (info->target_desc != NULL)
693 info->bfd_arch_info = choose_architecture_for_target
694 (info->bfd_arch_info, tdesc_architecture (info->target_desc));
695 /* From the default. */
696 if (info->bfd_arch_info == NULL)
697 info->bfd_arch_info = default_bfd_arch;
699 /* "(gdb) set byte-order ...". */
700 if (info->byte_order == BFD_ENDIAN_UNKNOWN
701 && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
702 info->byte_order = target_byte_order_user;
703 /* From the INFO struct. */
704 if (info->byte_order == BFD_ENDIAN_UNKNOWN
705 && info->abfd != NULL)
706 info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
707 : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
708 : BFD_ENDIAN_UNKNOWN);
709 /* From the default. */
710 if (info->byte_order == BFD_ENDIAN_UNKNOWN)
711 info->byte_order = default_byte_order;
713 /* "(gdb) set osabi ...". Handled by gdbarch_lookup_osabi. */
714 if (info->osabi == GDB_OSABI_UNINITIALIZED)
715 info->osabi = gdbarch_lookup_osabi (info->abfd);
717 /* Must have at least filled in the architecture. */
718 gdb_assert (info->bfd_arch_info != NULL);
723 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
726 _initialize_gdbarch_utils (void)
728 struct cmd_list_element *c;
729 add_setshow_enum_cmd ("endian", class_support,
730 endian_enum, &set_endian_string, _("\
731 Set endianness of target."), _("\
732 Show endianness of target."), NULL,
733 set_endian, show_endian,
734 &setlist, &showlist);