1 /* Dynamic architecture support for GDB, the GNU debugger.
3 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 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"
37 #include "floatformat.h"
40 always_use_struct_convention (int gcc_p, struct type *value_type)
45 enum return_value_convention
46 legacy_return_value (struct gdbarch *gdbarch, struct type *valtype,
47 struct regcache *regcache, gdb_byte *readbuf,
48 const gdb_byte *writebuf)
50 /* NOTE: cagney/2004-06-13: The gcc_p parameter to
51 USE_STRUCT_CONVENTION isn't used. */
52 int struct_return = ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
53 || TYPE_CODE (valtype) == TYPE_CODE_UNION
54 || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
55 && gdbarch_deprecated_use_struct_convention
56 (current_gdbarch, 0, valtype));
60 gdb_assert (!struct_return);
61 /* NOTE: cagney/2004-06-13: See stack.c:return_command. Old
62 architectures don't expect store_return_value to handle small
63 structures. Should not be called with such types. */
64 gdb_assert (TYPE_CODE (valtype) != TYPE_CODE_STRUCT
65 && TYPE_CODE (valtype) != TYPE_CODE_UNION);
66 gdbarch_store_return_value (current_gdbarch, valtype, regcache, writebuf);
71 gdb_assert (!struct_return);
72 gdbarch_extract_return_value (current_gdbarch,
73 valtype, regcache, readbuf);
77 return RETURN_VALUE_STRUCT_CONVENTION;
79 return RETURN_VALUE_REGISTER_CONVENTION;
83 legacy_register_sim_regno (int regnum)
85 /* Only makes sense to supply raw registers. */
86 gdb_assert (regnum >= 0 && regnum < gdbarch_num_regs (current_gdbarch));
87 /* NOTE: cagney/2002-05-13: The old code did it this way and it is
88 suspected that some GDB/SIM combinations may rely on this
89 behavour. The default should be one2one_register_sim_regno
91 if (gdbarch_register_name (current_gdbarch, regnum) != NULL
92 && gdbarch_register_name (current_gdbarch, regnum)[0] != '\0')
95 return LEGACY_SIM_REGNO_IGNORE;
99 generic_skip_trampoline_code (struct frame_info *frame, CORE_ADDR pc)
105 generic_skip_solib_resolver (struct gdbarch *gdbarch, CORE_ADDR pc)
111 generic_in_solib_return_trampoline (CORE_ADDR pc, char *name)
117 generic_in_function_epilogue_p (struct gdbarch *gdbarch, CORE_ADDR pc)
122 /* Helper functions for gdbarch_inner_than */
125 core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs)
131 core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs)
136 /* Misc helper functions for targets. */
139 core_addr_identity (CORE_ADDR addr)
145 convert_from_func_ptr_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr,
146 struct target_ops *targ)
152 no_op_reg_to_regnum (int reg)
158 default_elf_make_msymbol_special (asymbol *sym, struct minimal_symbol *msym)
164 default_coff_make_msymbol_special (int val, struct minimal_symbol *msym)
170 cannot_register_not (int regnum)
175 /* Legacy version of target_virtual_frame_pointer(). Assumes that
176 there is an gdbarch_deprecated_fp_regnum and that it is the same, cooked or
180 legacy_virtual_frame_pointer (CORE_ADDR pc,
182 LONGEST *frame_offset)
184 /* FIXME: cagney/2002-09-13: This code is used when identifying the
185 frame pointer of the current PC. It is assuming that a single
186 register and an offset can determine this. I think it should
187 instead generate a byte code expression as that would work better
188 with things like Dwarf2's CFI. */
189 if (gdbarch_deprecated_fp_regnum (current_gdbarch) >= 0
190 && gdbarch_deprecated_fp_regnum (current_gdbarch)
191 < gdbarch_num_regs (current_gdbarch))
192 *frame_regnum = gdbarch_deprecated_fp_regnum (current_gdbarch);
193 else if (gdbarch_sp_regnum (current_gdbarch) >= 0
194 && gdbarch_sp_regnum (current_gdbarch)
195 < gdbarch_num_regs (current_gdbarch))
196 *frame_regnum = gdbarch_sp_regnum (current_gdbarch);
198 /* Should this be an internal error? I guess so, it is reflecting
199 an architectural limitation in the current design. */
200 internal_error (__FILE__, __LINE__, _("No virtual frame pointer available"));
206 generic_convert_register_p (int regnum, struct type *type)
212 default_stabs_argument_has_addr (struct gdbarch *gdbarch, struct type *type)
218 generic_instruction_nullified (struct gdbarch *gdbarch,
219 struct regcache *regcache)
225 default_remote_register_number (struct gdbarch *gdbarch,
232 /* Functions to manipulate the endianness of the target. */
234 static int target_byte_order_user = BFD_ENDIAN_UNKNOWN;
236 static const char endian_big[] = "big";
237 static const char endian_little[] = "little";
238 static const char endian_auto[] = "auto";
239 static const char *endian_enum[] =
246 static const char *set_endian_string;
249 selected_byte_order (void)
251 if (target_byte_order_user != BFD_ENDIAN_UNKNOWN)
252 return gdbarch_byte_order (current_gdbarch);
254 return BFD_ENDIAN_UNKNOWN;
257 /* Called by ``show endian''. */
260 show_endian (struct ui_file *file, int from_tty, struct cmd_list_element *c,
263 if (target_byte_order_user == BFD_ENDIAN_UNKNOWN)
264 if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
265 fprintf_unfiltered (file, _("The target endianness is set automatically "
266 "(currently big endian)\n"));
268 fprintf_unfiltered (file, _("The target endianness is set automatically "
269 "(currently little endian)\n"));
271 if (gdbarch_byte_order (current_gdbarch) == BFD_ENDIAN_BIG)
272 fprintf_unfiltered (file,
273 _("The target is assumed to be big endian\n"));
275 fprintf_unfiltered (file,
276 _("The target is assumed to be little endian\n"));
280 set_endian (char *ignore_args, int from_tty, struct cmd_list_element *c)
282 struct gdbarch_info info;
284 gdbarch_info_init (&info);
286 if (set_endian_string == endian_auto)
288 target_byte_order_user = BFD_ENDIAN_UNKNOWN;
289 if (! gdbarch_update_p (info))
290 internal_error (__FILE__, __LINE__,
291 _("set_endian: architecture update failed"));
293 else if (set_endian_string == endian_little)
295 info.byte_order = BFD_ENDIAN_LITTLE;
296 if (! gdbarch_update_p (info))
297 printf_unfiltered (_("Little endian target not supported by GDB\n"));
299 target_byte_order_user = BFD_ENDIAN_LITTLE;
301 else if (set_endian_string == endian_big)
303 info.byte_order = BFD_ENDIAN_BIG;
304 if (! gdbarch_update_p (info))
305 printf_unfiltered (_("Big endian target not supported by GDB\n"));
307 target_byte_order_user = BFD_ENDIAN_BIG;
310 internal_error (__FILE__, __LINE__,
311 _("set_endian: bad value"));
313 show_endian (gdb_stdout, from_tty, NULL, NULL);
316 /* Given SELECTED, a currently selected BFD architecture, and
317 FROM_TARGET, a BFD architecture reported by the target description,
318 return what architecture to use. Either may be NULL; if both are
319 specified, we use the more specific. If the two are obviously
320 incompatible, warn the user. */
322 static const struct bfd_arch_info *
323 choose_architecture_for_target (const struct bfd_arch_info *selected,
324 const struct bfd_arch_info *from_target)
326 const struct bfd_arch_info *compat1, *compat2;
328 if (selected == NULL)
331 if (from_target == NULL)
334 /* struct bfd_arch_info objects are singletons: that is, there's
335 supposed to be exactly one instance for a given machine. So you
336 can tell whether two are equivalent by comparing pointers. */
337 if (from_target == selected)
340 /* BFD's 'A->compatible (A, B)' functions return zero if A and B are
341 incompatible. But if they are compatible, it returns the 'more
342 featureful' of the two arches. That is, if A can run code
343 written for B, but B can't run code written for A, then it'll
346 Some targets (e.g. MIPS as of 2006-12-04) don't fully
347 implement this, instead always returning NULL or the first
348 argument. We detect that case by checking both directions. */
350 compat1 = selected->compatible (selected, from_target);
351 compat2 = from_target->compatible (from_target, selected);
353 if (compat1 == NULL && compat2 == NULL)
355 warning (_("Selected architecture %s is not compatible "
356 "with reported target architecture %s"),
357 selected->printable_name, from_target->printable_name);
365 if (compat1 == compat2)
368 /* If the two didn't match, but one of them was a default architecture,
369 assume the more specific one is correct. This handles the case
370 where an executable or target description just says "mips", but
371 the other knows which MIPS variant. */
372 if (compat1->the_default)
374 if (compat2->the_default)
377 /* We have no idea which one is better. This is a bug, but not
378 a critical problem; warn the user. */
379 warning (_("Selected architecture %s is ambiguous with "
380 "reported target architecture %s"),
381 selected->printable_name, from_target->printable_name);
385 /* Functions to manipulate the architecture of the target */
387 enum set_arch { set_arch_auto, set_arch_manual };
389 static const struct bfd_arch_info *target_architecture_user;
391 static const char *set_architecture_string;
394 selected_architecture_name (void)
396 if (target_architecture_user == NULL)
399 return set_architecture_string;
402 /* Called if the user enters ``show architecture'' without an
406 show_architecture (struct ui_file *file, int from_tty,
407 struct cmd_list_element *c, const char *value)
410 arch = gdbarch_bfd_arch_info (current_gdbarch)->printable_name;
411 if (target_architecture_user == NULL)
412 fprintf_filtered (file, _("\
413 The target architecture is set automatically (currently %s)\n"), arch);
415 fprintf_filtered (file, _("\
416 The target architecture is assumed to be %s\n"), arch);
420 /* Called if the user enters ``set architecture'' with or without an
424 set_architecture (char *ignore_args, int from_tty, struct cmd_list_element *c)
426 struct gdbarch_info info;
428 gdbarch_info_init (&info);
430 if (strcmp (set_architecture_string, "auto") == 0)
432 target_architecture_user = NULL;
433 if (!gdbarch_update_p (info))
434 internal_error (__FILE__, __LINE__,
435 _("could not select an architecture automatically"));
439 info.bfd_arch_info = bfd_scan_arch (set_architecture_string);
440 if (info.bfd_arch_info == NULL)
441 internal_error (__FILE__, __LINE__,
442 _("set_architecture: bfd_scan_arch failed"));
443 if (gdbarch_update_p (info))
444 target_architecture_user = info.bfd_arch_info;
446 printf_unfiltered (_("Architecture `%s' not recognized.\n"),
447 set_architecture_string);
449 show_architecture (gdb_stdout, from_tty, NULL, NULL);
452 /* Try to select a global architecture that matches "info". Return
453 non-zero if the attempt succeds. */
455 gdbarch_update_p (struct gdbarch_info info)
457 struct gdbarch *new_gdbarch = gdbarch_find_by_info (info);
459 /* If there no architecture by that name, reject the request. */
460 if (new_gdbarch == NULL)
463 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
464 "Architecture not found\n");
468 /* If it is the same old architecture, accept the request (but don't
470 if (new_gdbarch == current_gdbarch)
473 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
474 "Architecture 0x%08lx (%s) unchanged\n",
476 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
480 /* It's a new architecture, swap it in. */
482 fprintf_unfiltered (gdb_stdlog, "gdbarch_update_p: "
483 "New architecture 0x%08lx (%s) selected\n",
485 gdbarch_bfd_arch_info (new_gdbarch)->printable_name);
486 deprecated_current_gdbarch_select_hack (new_gdbarch);
491 /* Return the architecture for ABFD. If no suitable architecture
492 could be find, return NULL. */
495 gdbarch_from_bfd (bfd *abfd)
497 struct gdbarch *old_gdbarch = current_gdbarch;
498 struct gdbarch *new_gdbarch;
499 struct gdbarch_info info;
501 /* If we call gdbarch_find_by_info without filling in info.abfd,
502 then it will use the global exec_bfd. That's fine if we don't
503 have one of those either. And that's the only time we should
504 reach here with a NULL ABFD argument - when we are discarding
506 gdb_assert (abfd != NULL || exec_bfd == NULL);
508 gdbarch_info_init (&info);
510 return gdbarch_find_by_info (info);
513 /* Set the dynamic target-system-dependent parameters (architecture,
514 byte-order) using information found in the BFD */
517 set_gdbarch_from_file (bfd *abfd)
519 struct gdbarch *gdbarch;
521 gdbarch = gdbarch_from_bfd (abfd);
523 error (_("Architecture of file not recognized."));
524 deprecated_current_gdbarch_select_hack (gdbarch);
527 /* Initialize the current architecture. Update the ``set
528 architecture'' command so that it specifies a list of valid
531 #ifdef DEFAULT_BFD_ARCH
532 extern const bfd_arch_info_type DEFAULT_BFD_ARCH;
533 static const bfd_arch_info_type *default_bfd_arch = &DEFAULT_BFD_ARCH;
535 static const bfd_arch_info_type *default_bfd_arch;
538 #ifdef DEFAULT_BFD_VEC
539 extern const bfd_target DEFAULT_BFD_VEC;
540 static const bfd_target *default_bfd_vec = &DEFAULT_BFD_VEC;
542 static const bfd_target *default_bfd_vec;
545 static int default_byte_order = BFD_ENDIAN_UNKNOWN;
548 initialize_current_architecture (void)
550 const char **arches = gdbarch_printable_names ();
552 /* determine a default architecture and byte order. */
553 struct gdbarch_info info;
554 gdbarch_info_init (&info);
556 /* Find a default architecture. */
557 if (default_bfd_arch == NULL)
559 /* Choose the architecture by taking the first one
561 const char *chosen = arches[0];
563 for (arch = arches; *arch != NULL; arch++)
565 if (strcmp (*arch, chosen) < 0)
569 internal_error (__FILE__, __LINE__,
570 _("initialize_current_architecture: No arch"));
571 default_bfd_arch = bfd_scan_arch (chosen);
572 if (default_bfd_arch == NULL)
573 internal_error (__FILE__, __LINE__,
574 _("initialize_current_architecture: Arch not found"));
577 info.bfd_arch_info = default_bfd_arch;
579 /* Take several guesses at a byte order. */
580 if (default_byte_order == BFD_ENDIAN_UNKNOWN
581 && default_bfd_vec != NULL)
583 /* Extract BFD's default vector's byte order. */
584 switch (default_bfd_vec->byteorder)
587 default_byte_order = BFD_ENDIAN_BIG;
589 case BFD_ENDIAN_LITTLE:
590 default_byte_order = BFD_ENDIAN_LITTLE;
596 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
598 /* look for ``*el-*'' in the target name. */
600 chp = strchr (target_name, '-');
602 && chp - 2 >= target_name
603 && strncmp (chp - 2, "el", 2) == 0)
604 default_byte_order = BFD_ENDIAN_LITTLE;
606 if (default_byte_order == BFD_ENDIAN_UNKNOWN)
608 /* Wire it to big-endian!!! */
609 default_byte_order = BFD_ENDIAN_BIG;
612 info.byte_order = default_byte_order;
614 if (! gdbarch_update_p (info))
615 internal_error (__FILE__, __LINE__,
616 _("initialize_current_architecture: Selection of "
617 "initial architecture failed"));
619 /* Create the ``set architecture'' command appending ``auto'' to the
620 list of architectures. */
622 struct cmd_list_element *c;
623 /* Append ``auto''. */
625 for (nr = 0; arches[nr] != NULL; nr++);
626 arches = xrealloc (arches, sizeof (char*) * (nr + 2));
627 arches[nr + 0] = "auto";
628 arches[nr + 1] = NULL;
629 add_setshow_enum_cmd ("architecture", class_support,
630 arches, &set_architecture_string, _("\
631 Set architecture of target."), _("\
632 Show architecture of target."), NULL,
633 set_architecture, show_architecture,
634 &setlist, &showlist);
635 add_alias_cmd ("processor", "architecture", class_support, 1, &setlist);
640 /* Initialize a gdbarch info to values that will be automatically
641 overridden. Note: Originally, this ``struct info'' was initialized
642 using memset(0). Unfortunately, that ran into problems, namely
643 BFD_ENDIAN_BIG is zero. An explicit initialization function that
644 can explicitly set each field to a well defined value is used. */
647 gdbarch_info_init (struct gdbarch_info *info)
649 memset (info, 0, sizeof (struct gdbarch_info));
650 info->byte_order = BFD_ENDIAN_UNKNOWN;
651 info->osabi = GDB_OSABI_UNINITIALIZED;
654 /* Similar to init, but this time fill in the blanks. Information is
655 obtained from the global "set ..." options and explicitly
656 initialized INFO fields. */
659 gdbarch_info_fill (struct gdbarch_info *info)
661 /* Check for the current file. */
662 if (info->abfd == NULL)
663 info->abfd = exec_bfd;
664 if (info->abfd == NULL)
665 info->abfd = core_bfd;
667 /* Check for the current target description. */
668 if (info->target_desc == NULL)
669 info->target_desc = target_current_description ();
671 /* "(gdb) set architecture ...". */
672 if (info->bfd_arch_info == NULL
673 && target_architecture_user)
674 info->bfd_arch_info = target_architecture_user;
676 if (info->bfd_arch_info == NULL
677 && info->abfd != NULL
678 && bfd_get_arch (info->abfd) != bfd_arch_unknown
679 && bfd_get_arch (info->abfd) != bfd_arch_obscure)
680 info->bfd_arch_info = bfd_get_arch_info (info->abfd);
681 /* From the target. */
682 if (info->target_desc != NULL)
683 info->bfd_arch_info = choose_architecture_for_target
684 (info->bfd_arch_info, tdesc_architecture (info->target_desc));
685 /* From the default. */
686 if (info->bfd_arch_info == NULL)
687 info->bfd_arch_info = default_bfd_arch;
689 /* "(gdb) set byte-order ...". */
690 if (info->byte_order == BFD_ENDIAN_UNKNOWN
691 && target_byte_order_user != BFD_ENDIAN_UNKNOWN)
692 info->byte_order = target_byte_order_user;
693 /* From the INFO struct. */
694 if (info->byte_order == BFD_ENDIAN_UNKNOWN
695 && info->abfd != NULL)
696 info->byte_order = (bfd_big_endian (info->abfd) ? BFD_ENDIAN_BIG
697 : bfd_little_endian (info->abfd) ? BFD_ENDIAN_LITTLE
698 : BFD_ENDIAN_UNKNOWN);
699 /* From the default. */
700 if (info->byte_order == BFD_ENDIAN_UNKNOWN)
701 info->byte_order = default_byte_order;
703 /* "(gdb) set osabi ...". Handled by gdbarch_lookup_osabi. */
704 if (info->osabi == GDB_OSABI_UNINITIALIZED)
705 info->osabi = gdbarch_lookup_osabi (info->abfd);
707 /* Must have at least filled in the architecture. */
708 gdb_assert (info->bfd_arch_info != NULL);
713 extern initialize_file_ftype _initialize_gdbarch_utils; /* -Wmissing-prototypes */
716 _initialize_gdbarch_utils (void)
718 struct cmd_list_element *c;
719 add_setshow_enum_cmd ("endian", class_support,
720 endian_enum, &set_endian_string, _("\
721 Set endianness of target."), _("\
722 Show endianness of target."), NULL,
723 set_endian, show_endian,
724 &setlist, &showlist);