1 /* Cache and manage frames for GDB, the GNU debugger.
3 Copyright (C) 1986-2013 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include "inferior.h" /* for inferior_ptid */
26 #include "gdb_assert.h"
28 #include "user-regs.h"
29 #include "gdb_obstack.h"
30 #include "dummy-frame.h"
31 #include "sentinel-frame.h"
35 #include "frame-unwind.h"
36 #include "frame-base.h"
41 #include "exceptions.h"
42 #include "gdbthread.h"
44 #include "inline-frame.h"
45 #include "tracepoint.h"
49 static struct frame_info
*get_prev_frame_1 (struct frame_info
*this_frame
);
50 static struct frame_info
*get_prev_frame_raw (struct frame_info
*this_frame
);
51 static const char *frame_stop_reason_symbol_string (enum unwind_stop_reason reason
);
53 /* We keep a cache of stack frames, each of which is a "struct
54 frame_info". The innermost one gets allocated (in
55 wait_for_inferior) each time the inferior stops; current_frame
56 points to it. Additional frames get allocated (in get_prev_frame)
57 as needed, and are chained through the next and prev fields. Any
58 time that the frame cache becomes invalid (most notably when we
59 execute something, but also if we change how we interpret the
60 frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
61 which reads new symbols)), we should call reinit_frame_cache. */
65 /* Level of this frame. The inner-most (youngest) frame is at level
66 0. As you move towards the outer-most (oldest) frame, the level
67 increases. This is a cached value. It could just as easily be
68 computed by counting back from the selected frame to the inner
70 /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be
71 reserved to indicate a bogus frame - one that has been created
72 just to keep GDB happy (GDB always needs a frame). For the
73 moment leave this as speculation. */
76 /* The frame's program space. */
77 struct program_space
*pspace
;
79 /* The frame's address space. */
80 struct address_space
*aspace
;
82 /* The frame's low-level unwinder and corresponding cache. The
83 low-level unwinder is responsible for unwinding register values
84 for the previous frame. The low-level unwind methods are
85 selected based on the presence, or otherwise, of register unwind
86 information such as CFI. */
88 const struct frame_unwind
*unwind
;
90 /* Cached copy of the previous frame's architecture. */
97 /* Cached copy of the previous frame's resume address. */
103 /* Cached copy of the previous frame's function address. */
110 /* This frame's ID. */
114 struct frame_id value
;
117 /* The frame's high-level base methods, and corresponding cache.
118 The high level base methods are selected based on the frame's
120 const struct frame_base
*base
;
123 /* Pointers to the next (down, inner, younger) and previous (up,
124 outer, older) frame_info's in the frame cache. */
125 struct frame_info
*next
; /* down, inner, younger */
127 struct frame_info
*prev
; /* up, outer, older */
129 /* The reason why we could not set PREV, or UNWIND_NO_REASON if we
130 could. Only valid when PREV_P is set. */
131 enum unwind_stop_reason stop_reason
;
134 /* A frame stash used to speed up frame lookups. Create a hash table
135 to stash frames previously accessed from the frame cache for
136 quicker subsequent retrieval. The hash table is emptied whenever
137 the frame cache is invalidated. */
139 static htab_t frame_stash
;
141 /* Internal function to calculate a hash from the frame_id addresses,
142 using as many valid addresses as possible. Frames below level 0
143 are not stored in the hash table. */
146 frame_addr_hash (const void *ap
)
148 const struct frame_info
*frame
= ap
;
149 const struct frame_id f_id
= frame
->this_id
.value
;
152 gdb_assert (f_id
.stack_addr_p
|| f_id
.code_addr_p
153 || f_id
.special_addr_p
);
155 if (f_id
.stack_addr_p
)
156 hash
= iterative_hash (&f_id
.stack_addr
,
157 sizeof (f_id
.stack_addr
), hash
);
158 if (f_id
.code_addr_p
)
159 hash
= iterative_hash (&f_id
.code_addr
,
160 sizeof (f_id
.code_addr
), hash
);
161 if (f_id
.special_addr_p
)
162 hash
= iterative_hash (&f_id
.special_addr
,
163 sizeof (f_id
.special_addr
), hash
);
168 /* Internal equality function for the hash table. This function
169 defers equality operations to frame_id_eq. */
172 frame_addr_hash_eq (const void *a
, const void *b
)
174 const struct frame_info
*f_entry
= a
;
175 const struct frame_info
*f_element
= b
;
177 return frame_id_eq (f_entry
->this_id
.value
,
178 f_element
->this_id
.value
);
181 /* Internal function to create the frame_stash hash table. 100 seems
182 to be a good compromise to start the hash table at. */
185 frame_stash_create (void)
187 frame_stash
= htab_create (100,
193 /* Internal function to add a frame to the frame_stash hash table.
194 Returns false if a frame with the same ID was already stashed, true
198 frame_stash_add (struct frame_info
*frame
)
200 struct frame_info
**slot
;
202 /* Do not try to stash the sentinel frame. */
203 gdb_assert (frame
->level
>= 0);
205 slot
= (struct frame_info
**) htab_find_slot (frame_stash
,
209 /* If we already have a frame in the stack with the same id, we
210 either have a stack cycle (corrupted stack?), or some bug
211 elsewhere in GDB. In any case, ignore the duplicate and return
212 an indication to the caller. */
220 /* Internal function to search the frame stash for an entry with the
221 given frame ID. If found, return that frame. Otherwise return
224 static struct frame_info
*
225 frame_stash_find (struct frame_id id
)
227 struct frame_info dummy
;
228 struct frame_info
*frame
;
230 dummy
.this_id
.value
= id
;
231 frame
= htab_find (frame_stash
, &dummy
);
235 /* Internal function to invalidate the frame stash by removing all
236 entries in it. This only occurs when the frame cache is
240 frame_stash_invalidate (void)
242 htab_empty (frame_stash
);
245 /* Flag to control debugging. */
247 unsigned int frame_debug
;
249 show_frame_debug (struct ui_file
*file
, int from_tty
,
250 struct cmd_list_element
*c
, const char *value
)
252 fprintf_filtered (file
, _("Frame debugging is %s.\n"), value
);
255 /* Flag to indicate whether backtraces should stop at main et.al. */
257 static int backtrace_past_main
;
259 show_backtrace_past_main (struct ui_file
*file
, int from_tty
,
260 struct cmd_list_element
*c
, const char *value
)
262 fprintf_filtered (file
,
263 _("Whether backtraces should "
264 "continue past \"main\" is %s.\n"),
268 static int backtrace_past_entry
;
270 show_backtrace_past_entry (struct ui_file
*file
, int from_tty
,
271 struct cmd_list_element
*c
, const char *value
)
273 fprintf_filtered (file
, _("Whether backtraces should continue past the "
274 "entry point of a program is %s.\n"),
278 static unsigned int backtrace_limit
= UINT_MAX
;
280 show_backtrace_limit (struct ui_file
*file
, int from_tty
,
281 struct cmd_list_element
*c
, const char *value
)
283 fprintf_filtered (file
,
284 _("An upper bound on the number "
285 "of backtrace levels is %s.\n"),
291 fprint_field (struct ui_file
*file
, const char *name
, int p
, CORE_ADDR addr
)
294 fprintf_unfiltered (file
, "%s=%s", name
, hex_string (addr
));
296 fprintf_unfiltered (file
, "!%s", name
);
300 fprint_frame_id (struct ui_file
*file
, struct frame_id id
)
302 fprintf_unfiltered (file
, "{");
303 fprint_field (file
, "stack", id
.stack_addr_p
, id
.stack_addr
);
304 fprintf_unfiltered (file
, ",");
305 fprint_field (file
, "code", id
.code_addr_p
, id
.code_addr
);
306 fprintf_unfiltered (file
, ",");
307 fprint_field (file
, "special", id
.special_addr_p
, id
.special_addr
);
308 if (id
.artificial_depth
)
309 fprintf_unfiltered (file
, ",artificial=%d", id
.artificial_depth
);
310 fprintf_unfiltered (file
, "}");
314 fprint_frame_type (struct ui_file
*file
, enum frame_type type
)
319 fprintf_unfiltered (file
, "NORMAL_FRAME");
322 fprintf_unfiltered (file
, "DUMMY_FRAME");
325 fprintf_unfiltered (file
, "INLINE_FRAME");
328 fprintf_unfiltered (file
, "TAILCALL_FRAME");
331 fprintf_unfiltered (file
, "SIGTRAMP_FRAME");
334 fprintf_unfiltered (file
, "ARCH_FRAME");
337 fprintf_unfiltered (file
, "SENTINEL_FRAME");
340 fprintf_unfiltered (file
, "<unknown type>");
346 fprint_frame (struct ui_file
*file
, struct frame_info
*fi
)
350 fprintf_unfiltered (file
, "<NULL frame>");
353 fprintf_unfiltered (file
, "{");
354 fprintf_unfiltered (file
, "level=%d", fi
->level
);
355 fprintf_unfiltered (file
, ",");
356 fprintf_unfiltered (file
, "type=");
357 if (fi
->unwind
!= NULL
)
358 fprint_frame_type (file
, fi
->unwind
->type
);
360 fprintf_unfiltered (file
, "<unknown>");
361 fprintf_unfiltered (file
, ",");
362 fprintf_unfiltered (file
, "unwind=");
363 if (fi
->unwind
!= NULL
)
364 gdb_print_host_address (fi
->unwind
, file
);
366 fprintf_unfiltered (file
, "<unknown>");
367 fprintf_unfiltered (file
, ",");
368 fprintf_unfiltered (file
, "pc=");
369 if (fi
->next
!= NULL
&& fi
->next
->prev_pc
.p
)
370 fprintf_unfiltered (file
, "%s", hex_string (fi
->next
->prev_pc
.value
));
372 fprintf_unfiltered (file
, "<unknown>");
373 fprintf_unfiltered (file
, ",");
374 fprintf_unfiltered (file
, "id=");
376 fprint_frame_id (file
, fi
->this_id
.value
);
378 fprintf_unfiltered (file
, "<unknown>");
379 fprintf_unfiltered (file
, ",");
380 fprintf_unfiltered (file
, "func=");
381 if (fi
->next
!= NULL
&& fi
->next
->prev_func
.p
)
382 fprintf_unfiltered (file
, "%s", hex_string (fi
->next
->prev_func
.addr
));
384 fprintf_unfiltered (file
, "<unknown>");
385 fprintf_unfiltered (file
, "}");
388 /* Given FRAME, return the enclosing frame as found in real frames read-in from
389 inferior memory. Skip any previous frames which were made up by GDB.
390 Return the original frame if no immediate previous frames exist. */
392 static struct frame_info
*
393 skip_artificial_frames (struct frame_info
*frame
)
395 while (get_frame_type (frame
) == INLINE_FRAME
396 || get_frame_type (frame
) == TAILCALL_FRAME
)
397 frame
= get_prev_frame (frame
);
402 /* Compute the frame's uniq ID that can be used to, later, re-find the
406 compute_frame_id (struct frame_info
*fi
)
408 gdb_assert (!fi
->this_id
.p
);
411 fprintf_unfiltered (gdb_stdlog
, "{ compute_frame_id (fi=%d) ",
413 /* Find the unwinder. */
414 if (fi
->unwind
== NULL
)
415 frame_unwind_find_by_frame (fi
, &fi
->prologue_cache
);
416 /* Find THIS frame's ID. */
417 /* Default to outermost if no ID is found. */
418 fi
->this_id
.value
= outer_frame_id
;
419 fi
->unwind
->this_id (fi
, &fi
->prologue_cache
, &fi
->this_id
.value
);
420 gdb_assert (frame_id_p (fi
->this_id
.value
));
424 fprintf_unfiltered (gdb_stdlog
, "-> ");
425 fprint_frame_id (gdb_stdlog
, fi
->this_id
.value
);
426 fprintf_unfiltered (gdb_stdlog
, " }\n");
430 /* Return a frame uniq ID that can be used to, later, re-find the
434 get_frame_id (struct frame_info
*fi
)
437 return null_frame_id
;
439 gdb_assert (fi
->this_id
.p
);
440 return fi
->this_id
.value
;
444 get_stack_frame_id (struct frame_info
*next_frame
)
446 return get_frame_id (skip_artificial_frames (next_frame
));
450 frame_unwind_caller_id (struct frame_info
*next_frame
)
452 struct frame_info
*this_frame
;
454 /* Use get_prev_frame_1, and not get_prev_frame. The latter will truncate
455 the frame chain, leading to this function unintentionally
456 returning a null_frame_id (e.g., when a caller requests the frame
457 ID of "main()"s caller. */
459 next_frame
= skip_artificial_frames (next_frame
);
460 this_frame
= get_prev_frame_1 (next_frame
);
462 return get_frame_id (skip_artificial_frames (this_frame
));
464 return null_frame_id
;
467 const struct frame_id null_frame_id
; /* All zeros. */
468 const struct frame_id outer_frame_id
= { 0, 0, 0, 0, 0, 1, 0 };
471 frame_id_build_special (CORE_ADDR stack_addr
, CORE_ADDR code_addr
,
472 CORE_ADDR special_addr
)
474 struct frame_id id
= null_frame_id
;
476 id
.stack_addr
= stack_addr
;
478 id
.code_addr
= code_addr
;
480 id
.special_addr
= special_addr
;
481 id
.special_addr_p
= 1;
486 frame_id_build (CORE_ADDR stack_addr
, CORE_ADDR code_addr
)
488 struct frame_id id
= null_frame_id
;
490 id
.stack_addr
= stack_addr
;
492 id
.code_addr
= code_addr
;
498 frame_id_build_wild (CORE_ADDR stack_addr
)
500 struct frame_id id
= null_frame_id
;
502 id
.stack_addr
= stack_addr
;
508 frame_id_p (struct frame_id l
)
512 /* The frame is valid iff it has a valid stack address. */
514 /* outer_frame_id is also valid. */
515 if (!p
&& memcmp (&l
, &outer_frame_id
, sizeof (l
)) == 0)
519 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_p (l=");
520 fprint_frame_id (gdb_stdlog
, l
);
521 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", p
);
527 frame_id_artificial_p (struct frame_id l
)
532 return (l
.artificial_depth
!= 0);
536 frame_id_eq (struct frame_id l
, struct frame_id r
)
540 if (!l
.stack_addr_p
&& l
.special_addr_p
541 && !r
.stack_addr_p
&& r
.special_addr_p
)
542 /* The outermost frame marker is equal to itself. This is the
543 dodgy thing about outer_frame_id, since between execution steps
544 we might step into another function - from which we can't
545 unwind either. More thought required to get rid of
548 else if (!l
.stack_addr_p
|| !r
.stack_addr_p
)
549 /* Like a NaN, if either ID is invalid, the result is false.
550 Note that a frame ID is invalid iff it is the null frame ID. */
552 else if (l
.stack_addr
!= r
.stack_addr
)
553 /* If .stack addresses are different, the frames are different. */
555 else if (l
.code_addr_p
&& r
.code_addr_p
&& l
.code_addr
!= r
.code_addr
)
556 /* An invalid code addr is a wild card. If .code addresses are
557 different, the frames are different. */
559 else if (l
.special_addr_p
&& r
.special_addr_p
560 && l
.special_addr
!= r
.special_addr
)
561 /* An invalid special addr is a wild card (or unused). Otherwise
562 if special addresses are different, the frames are different. */
564 else if (l
.artificial_depth
!= r
.artificial_depth
)
565 /* If artifical depths are different, the frames must be different. */
568 /* Frames are equal. */
573 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_eq (l=");
574 fprint_frame_id (gdb_stdlog
, l
);
575 fprintf_unfiltered (gdb_stdlog
, ",r=");
576 fprint_frame_id (gdb_stdlog
, r
);
577 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", eq
);
582 /* Safety net to check whether frame ID L should be inner to
583 frame ID R, according to their stack addresses.
585 This method cannot be used to compare arbitrary frames, as the
586 ranges of valid stack addresses may be discontiguous (e.g. due
589 However, it can be used as safety net to discover invalid frame
590 IDs in certain circumstances. Assuming that NEXT is the immediate
591 inner frame to THIS and that NEXT and THIS are both NORMAL frames:
593 * The stack address of NEXT must be inner-than-or-equal to the stack
596 Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind
599 * If NEXT and THIS have different stack addresses, no other frame
600 in the frame chain may have a stack address in between.
602 Therefore, if frame_id_inner (TEST, THIS) holds, but
603 frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer
604 to a valid frame in the frame chain.
606 The sanity checks above cannot be performed when a SIGTRAMP frame
607 is involved, because signal handlers might be executed on a different
608 stack than the stack used by the routine that caused the signal
609 to be raised. This can happen for instance when a thread exceeds
610 its maximum stack size. In this case, certain compilers implement
611 a stack overflow strategy that cause the handler to be run on a
615 frame_id_inner (struct gdbarch
*gdbarch
, struct frame_id l
, struct frame_id r
)
619 if (!l
.stack_addr_p
|| !r
.stack_addr_p
)
620 /* Like NaN, any operation involving an invalid ID always fails. */
622 else if (l
.artificial_depth
> r
.artificial_depth
623 && l
.stack_addr
== r
.stack_addr
624 && l
.code_addr_p
== r
.code_addr_p
625 && l
.special_addr_p
== r
.special_addr_p
626 && l
.special_addr
== r
.special_addr
)
628 /* Same function, different inlined functions. */
629 struct block
*lb
, *rb
;
631 gdb_assert (l
.code_addr_p
&& r
.code_addr_p
);
633 lb
= block_for_pc (l
.code_addr
);
634 rb
= block_for_pc (r
.code_addr
);
636 if (lb
== NULL
|| rb
== NULL
)
637 /* Something's gone wrong. */
640 /* This will return true if LB and RB are the same block, or
641 if the block with the smaller depth lexically encloses the
642 block with the greater depth. */
643 inner
= contained_in (lb
, rb
);
646 /* Only return non-zero when strictly inner than. Note that, per
647 comment in "frame.h", there is some fuzz here. Frameless
648 functions are not strictly inner than (same .stack but
649 different .code and/or .special address). */
650 inner
= gdbarch_inner_than (gdbarch
, l
.stack_addr
, r
.stack_addr
);
653 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_inner (l=");
654 fprint_frame_id (gdb_stdlog
, l
);
655 fprintf_unfiltered (gdb_stdlog
, ",r=");
656 fprint_frame_id (gdb_stdlog
, r
);
657 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", inner
);
663 frame_find_by_id (struct frame_id id
)
665 struct frame_info
*frame
, *prev_frame
;
667 /* ZERO denotes the null frame, let the caller decide what to do
668 about it. Should it instead return get_current_frame()? */
669 if (!frame_id_p (id
))
672 /* Try using the frame stash first. Finding it there removes the need
673 to perform the search by looping over all frames, which can be very
674 CPU-intensive if the number of frames is very high (the loop is O(n)
675 and get_prev_frame performs a series of checks that are relatively
676 expensive). This optimization is particularly useful when this function
677 is called from another function (such as value_fetch_lazy, case
678 VALUE_LVAL (val) == lval_register) which already loops over all frames,
679 making the overall behavior O(n^2). */
680 frame
= frame_stash_find (id
);
684 for (frame
= get_current_frame (); ; frame
= prev_frame
)
686 struct frame_id
this = get_frame_id (frame
);
688 if (frame_id_eq (id
, this))
689 /* An exact match. */
692 prev_frame
= get_prev_frame (frame
);
696 /* As a safety net to avoid unnecessary backtracing while trying
697 to find an invalid ID, we check for a common situation where
698 we can detect from comparing stack addresses that no other
699 frame in the current frame chain can have this ID. See the
700 comment at frame_id_inner for details. */
701 if (get_frame_type (frame
) == NORMAL_FRAME
702 && !frame_id_inner (get_frame_arch (frame
), id
, this)
703 && frame_id_inner (get_frame_arch (prev_frame
), id
,
704 get_frame_id (prev_frame
)))
711 frame_unwind_pc_if_available (struct frame_info
*this_frame
, CORE_ADDR
*pc
)
713 if (!this_frame
->prev_pc
.p
)
715 if (gdbarch_unwind_pc_p (frame_unwind_arch (this_frame
)))
717 volatile struct gdb_exception ex
;
718 struct gdbarch
*prev_gdbarch
;
721 /* The right way. The `pure' way. The one true way. This
722 method depends solely on the register-unwind code to
723 determine the value of registers in THIS frame, and hence
724 the value of this frame's PC (resume address). A typical
725 implementation is no more than:
727 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
728 return extract_unsigned_integer (buf, size of ISA_PC_REGNUM);
730 Note: this method is very heavily dependent on a correct
731 register-unwind implementation, it pays to fix that
732 method first; this method is frame type agnostic, since
733 it only deals with register values, it works with any
734 frame. This is all in stark contrast to the old
735 FRAME_SAVED_PC which would try to directly handle all the
736 different ways that a PC could be unwound. */
737 prev_gdbarch
= frame_unwind_arch (this_frame
);
739 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
741 pc
= gdbarch_unwind_pc (prev_gdbarch
, this_frame
);
743 if (ex
.reason
< 0 && ex
.error
== NOT_AVAILABLE_ERROR
)
745 this_frame
->prev_pc
.p
= -1;
748 fprintf_unfiltered (gdb_stdlog
,
749 "{ frame_unwind_pc (this_frame=%d)"
750 " -> <unavailable> }\n",
753 else if (ex
.reason
< 0)
755 throw_exception (ex
);
759 this_frame
->prev_pc
.value
= pc
;
760 this_frame
->prev_pc
.p
= 1;
762 fprintf_unfiltered (gdb_stdlog
,
763 "{ frame_unwind_pc (this_frame=%d) "
766 hex_string (this_frame
->prev_pc
.value
));
770 internal_error (__FILE__
, __LINE__
, _("No unwind_pc method"));
772 if (this_frame
->prev_pc
.p
< 0)
779 *pc
= this_frame
->prev_pc
.value
;
785 frame_unwind_pc (struct frame_info
*this_frame
)
789 if (!frame_unwind_pc_if_available (this_frame
, &pc
))
790 throw_error (NOT_AVAILABLE_ERROR
, _("PC not available"));
796 frame_unwind_caller_pc (struct frame_info
*this_frame
)
798 return frame_unwind_pc (skip_artificial_frames (this_frame
));
802 frame_unwind_caller_pc_if_available (struct frame_info
*this_frame
,
805 return frame_unwind_pc_if_available (skip_artificial_frames (this_frame
), pc
);
809 get_frame_func_if_available (struct frame_info
*this_frame
, CORE_ADDR
*pc
)
811 struct frame_info
*next_frame
= this_frame
->next
;
813 if (!next_frame
->prev_func
.p
)
815 CORE_ADDR addr_in_block
;
817 /* Make certain that this, and not the adjacent, function is
819 if (!get_frame_address_in_block_if_available (this_frame
, &addr_in_block
))
821 next_frame
->prev_func
.p
= -1;
823 fprintf_unfiltered (gdb_stdlog
,
824 "{ get_frame_func (this_frame=%d)"
825 " -> unavailable }\n",
830 next_frame
->prev_func
.p
= 1;
831 next_frame
->prev_func
.addr
= get_pc_function_start (addr_in_block
);
833 fprintf_unfiltered (gdb_stdlog
,
834 "{ get_frame_func (this_frame=%d) -> %s }\n",
836 hex_string (next_frame
->prev_func
.addr
));
840 if (next_frame
->prev_func
.p
< 0)
847 *pc
= next_frame
->prev_func
.addr
;
853 get_frame_func (struct frame_info
*this_frame
)
857 if (!get_frame_func_if_available (this_frame
, &pc
))
858 throw_error (NOT_AVAILABLE_ERROR
, _("PC not available"));
863 static enum register_status
864 do_frame_register_read (void *src
, int regnum
, gdb_byte
*buf
)
866 if (!deprecated_frame_register_read (src
, regnum
, buf
))
867 return REG_UNAVAILABLE
;
873 frame_save_as_regcache (struct frame_info
*this_frame
)
875 struct address_space
*aspace
= get_frame_address_space (this_frame
);
876 struct regcache
*regcache
= regcache_xmalloc (get_frame_arch (this_frame
),
878 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (regcache
);
880 regcache_save (regcache
, do_frame_register_read
, this_frame
);
881 discard_cleanups (cleanups
);
886 frame_pop (struct frame_info
*this_frame
)
888 struct frame_info
*prev_frame
;
889 struct regcache
*scratch
;
890 struct cleanup
*cleanups
;
892 if (get_frame_type (this_frame
) == DUMMY_FRAME
)
894 /* Popping a dummy frame involves restoring more than just registers.
895 dummy_frame_pop does all the work. */
896 dummy_frame_pop (get_frame_id (this_frame
));
900 /* Ensure that we have a frame to pop to. */
901 prev_frame
= get_prev_frame_1 (this_frame
);
904 error (_("Cannot pop the initial frame."));
906 /* Ignore TAILCALL_FRAME type frames, they were executed already before
907 entering THISFRAME. */
908 while (get_frame_type (prev_frame
) == TAILCALL_FRAME
)
909 prev_frame
= get_prev_frame (prev_frame
);
911 /* Make a copy of all the register values unwound from this frame.
912 Save them in a scratch buffer so that there isn't a race between
913 trying to extract the old values from the current regcache while
914 at the same time writing new values into that same cache. */
915 scratch
= frame_save_as_regcache (prev_frame
);
916 cleanups
= make_cleanup_regcache_xfree (scratch
);
918 /* FIXME: cagney/2003-03-16: It should be possible to tell the
919 target's register cache that it is about to be hit with a burst
920 register transfer and that the sequence of register writes should
921 be batched. The pair target_prepare_to_store() and
922 target_store_registers() kind of suggest this functionality.
923 Unfortunately, they don't implement it. Their lack of a formal
924 definition can lead to targets writing back bogus values
925 (arguably a bug in the target code mind). */
926 /* Now copy those saved registers into the current regcache.
927 Here, regcache_cpy() calls regcache_restore(). */
928 regcache_cpy (get_current_regcache (), scratch
);
929 do_cleanups (cleanups
);
931 /* We've made right mess of GDB's local state, just discard
933 reinit_frame_cache ();
937 frame_register_unwind (struct frame_info
*frame
, int regnum
,
938 int *optimizedp
, int *unavailablep
,
939 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
940 int *realnump
, gdb_byte
*bufferp
)
944 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
945 that the value proper does not need to be fetched. */
946 gdb_assert (optimizedp
!= NULL
);
947 gdb_assert (lvalp
!= NULL
);
948 gdb_assert (addrp
!= NULL
);
949 gdb_assert (realnump
!= NULL
);
950 /* gdb_assert (bufferp != NULL); */
952 value
= frame_unwind_register_value (frame
, regnum
);
954 gdb_assert (value
!= NULL
);
956 *optimizedp
= value_optimized_out (value
);
957 *unavailablep
= !value_entirely_available (value
);
958 *lvalp
= VALUE_LVAL (value
);
959 *addrp
= value_address (value
);
960 *realnump
= VALUE_REGNUM (value
);
964 if (!*optimizedp
&& !*unavailablep
)
965 memcpy (bufferp
, value_contents_all (value
),
966 TYPE_LENGTH (value_type (value
)));
968 memset (bufferp
, 0, TYPE_LENGTH (value_type (value
)));
971 /* Dispose of the new value. This prevents watchpoints from
972 trying to watch the saved frame pointer. */
973 release_value (value
);
978 frame_register (struct frame_info
*frame
, int regnum
,
979 int *optimizedp
, int *unavailablep
, enum lval_type
*lvalp
,
980 CORE_ADDR
*addrp
, int *realnump
, gdb_byte
*bufferp
)
982 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
983 that the value proper does not need to be fetched. */
984 gdb_assert (optimizedp
!= NULL
);
985 gdb_assert (lvalp
!= NULL
);
986 gdb_assert (addrp
!= NULL
);
987 gdb_assert (realnump
!= NULL
);
988 /* gdb_assert (bufferp != NULL); */
990 /* Obtain the register value by unwinding the register from the next
991 (more inner frame). */
992 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
993 frame_register_unwind (frame
->next
, regnum
, optimizedp
, unavailablep
,
994 lvalp
, addrp
, realnump
, bufferp
);
998 frame_unwind_register (struct frame_info
*frame
, int regnum
, gdb_byte
*buf
)
1004 enum lval_type lval
;
1006 frame_register_unwind (frame
, regnum
, &optimized
, &unavailable
,
1007 &lval
, &addr
, &realnum
, buf
);
1010 error (_("Register %d was not saved"), regnum
);
1012 throw_error (NOT_AVAILABLE_ERROR
,
1013 _("Register %d is not available"), regnum
);
1017 get_frame_register (struct frame_info
*frame
,
1018 int regnum
, gdb_byte
*buf
)
1020 frame_unwind_register (frame
->next
, regnum
, buf
);
1024 frame_unwind_register_value (struct frame_info
*frame
, int regnum
)
1026 struct gdbarch
*gdbarch
;
1027 struct value
*value
;
1029 gdb_assert (frame
!= NULL
);
1030 gdbarch
= frame_unwind_arch (frame
);
1034 fprintf_unfiltered (gdb_stdlog
,
1035 "{ frame_unwind_register_value "
1036 "(frame=%d,regnum=%d(%s),...) ",
1037 frame
->level
, regnum
,
1038 user_reg_map_regnum_to_name (gdbarch
, regnum
));
1041 /* Find the unwinder. */
1042 if (frame
->unwind
== NULL
)
1043 frame_unwind_find_by_frame (frame
, &frame
->prologue_cache
);
1045 /* Ask this frame to unwind its register. */
1046 value
= frame
->unwind
->prev_register (frame
, &frame
->prologue_cache
, regnum
);
1050 fprintf_unfiltered (gdb_stdlog
, "->");
1051 if (value_optimized_out (value
))
1053 fprintf_unfiltered (gdb_stdlog
, " ");
1054 val_print_optimized_out (value
, gdb_stdlog
);
1058 if (VALUE_LVAL (value
) == lval_register
)
1059 fprintf_unfiltered (gdb_stdlog
, " register=%d",
1060 VALUE_REGNUM (value
));
1061 else if (VALUE_LVAL (value
) == lval_memory
)
1062 fprintf_unfiltered (gdb_stdlog
, " address=%s",
1064 value_address (value
)));
1066 fprintf_unfiltered (gdb_stdlog
, " computed");
1068 if (value_lazy (value
))
1069 fprintf_unfiltered (gdb_stdlog
, " lazy");
1073 const gdb_byte
*buf
= value_contents (value
);
1075 fprintf_unfiltered (gdb_stdlog
, " bytes=");
1076 fprintf_unfiltered (gdb_stdlog
, "[");
1077 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
1078 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
1079 fprintf_unfiltered (gdb_stdlog
, "]");
1083 fprintf_unfiltered (gdb_stdlog
, " }\n");
1090 get_frame_register_value (struct frame_info
*frame
, int regnum
)
1092 return frame_unwind_register_value (frame
->next
, regnum
);
1096 frame_unwind_register_signed (struct frame_info
*frame
, int regnum
)
1098 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
1099 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
1100 int size
= register_size (gdbarch
, regnum
);
1101 gdb_byte buf
[MAX_REGISTER_SIZE
];
1103 frame_unwind_register (frame
, regnum
, buf
);
1104 return extract_signed_integer (buf
, size
, byte_order
);
1108 get_frame_register_signed (struct frame_info
*frame
, int regnum
)
1110 return frame_unwind_register_signed (frame
->next
, regnum
);
1114 frame_unwind_register_unsigned (struct frame_info
*frame
, int regnum
)
1116 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
1117 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
1118 int size
= register_size (gdbarch
, regnum
);
1119 gdb_byte buf
[MAX_REGISTER_SIZE
];
1121 frame_unwind_register (frame
, regnum
, buf
);
1122 return extract_unsigned_integer (buf
, size
, byte_order
);
1126 get_frame_register_unsigned (struct frame_info
*frame
, int regnum
)
1128 return frame_unwind_register_unsigned (frame
->next
, regnum
);
1132 read_frame_register_unsigned (struct frame_info
*frame
, int regnum
,
1135 struct value
*regval
= get_frame_register_value (frame
, regnum
);
1137 if (!value_optimized_out (regval
)
1138 && value_entirely_available (regval
))
1140 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1141 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
1142 int size
= register_size (gdbarch
, VALUE_REGNUM (regval
));
1144 *val
= extract_unsigned_integer (value_contents (regval
), size
, byte_order
);
1152 put_frame_register (struct frame_info
*frame
, int regnum
,
1153 const gdb_byte
*buf
)
1155 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1159 enum lval_type lval
;
1162 frame_register (frame
, regnum
, &optim
, &unavail
,
1163 &lval
, &addr
, &realnum
, NULL
);
1165 error (_("Attempt to assign to a register that was not saved."));
1170 write_memory (addr
, buf
, register_size (gdbarch
, regnum
));
1174 regcache_cooked_write (get_current_regcache (), realnum
, buf
);
1177 error (_("Attempt to assign to an unmodifiable value."));
1181 /* This function is deprecated. Use get_frame_register_value instead,
1182 which provides more accurate information.
1184 Find and return the value of REGNUM for the specified stack frame.
1185 The number of bytes copied is REGISTER_SIZE (REGNUM).
1187 Returns 0 if the register value could not be found. */
1190 deprecated_frame_register_read (struct frame_info
*frame
, int regnum
,
1195 enum lval_type lval
;
1199 frame_register (frame
, regnum
, &optimized
, &unavailable
,
1200 &lval
, &addr
, &realnum
, myaddr
);
1202 return !optimized
&& !unavailable
;
1206 get_frame_register_bytes (struct frame_info
*frame
, int regnum
,
1207 CORE_ADDR offset
, int len
, gdb_byte
*myaddr
,
1208 int *optimizedp
, int *unavailablep
)
1210 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1215 /* Skip registers wholly inside of OFFSET. */
1216 while (offset
>= register_size (gdbarch
, regnum
))
1218 offset
-= register_size (gdbarch
, regnum
);
1222 /* Ensure that we will not read beyond the end of the register file.
1223 This can only ever happen if the debug information is bad. */
1225 numregs
= gdbarch_num_regs (gdbarch
) + gdbarch_num_pseudo_regs (gdbarch
);
1226 for (i
= regnum
; i
< numregs
; i
++)
1228 int thissize
= register_size (gdbarch
, i
);
1231 break; /* This register is not available on this architecture. */
1232 maxsize
+= thissize
;
1235 error (_("Bad debug information detected: "
1236 "Attempt to read %d bytes from registers."), len
);
1238 /* Copy the data. */
1241 int curr_len
= register_size (gdbarch
, regnum
) - offset
;
1246 if (curr_len
== register_size (gdbarch
, regnum
))
1248 enum lval_type lval
;
1252 frame_register (frame
, regnum
, optimizedp
, unavailablep
,
1253 &lval
, &addr
, &realnum
, myaddr
);
1254 if (*optimizedp
|| *unavailablep
)
1259 gdb_byte buf
[MAX_REGISTER_SIZE
];
1260 enum lval_type lval
;
1264 frame_register (frame
, regnum
, optimizedp
, unavailablep
,
1265 &lval
, &addr
, &realnum
, buf
);
1266 if (*optimizedp
|| *unavailablep
)
1268 memcpy (myaddr
, buf
+ offset
, curr_len
);
1283 put_frame_register_bytes (struct frame_info
*frame
, int regnum
,
1284 CORE_ADDR offset
, int len
, const gdb_byte
*myaddr
)
1286 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1288 /* Skip registers wholly inside of OFFSET. */
1289 while (offset
>= register_size (gdbarch
, regnum
))
1291 offset
-= register_size (gdbarch
, regnum
);
1295 /* Copy the data. */
1298 int curr_len
= register_size (gdbarch
, regnum
) - offset
;
1303 if (curr_len
== register_size (gdbarch
, regnum
))
1305 put_frame_register (frame
, regnum
, myaddr
);
1309 gdb_byte buf
[MAX_REGISTER_SIZE
];
1311 deprecated_frame_register_read (frame
, regnum
, buf
);
1312 memcpy (buf
+ offset
, myaddr
, curr_len
);
1313 put_frame_register (frame
, regnum
, buf
);
1323 /* Create a sentinel frame. */
1325 static struct frame_info
*
1326 create_sentinel_frame (struct program_space
*pspace
, struct regcache
*regcache
)
1328 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1331 frame
->pspace
= pspace
;
1332 frame
->aspace
= get_regcache_aspace (regcache
);
1333 /* Explicitly initialize the sentinel frame's cache. Provide it
1334 with the underlying regcache. In the future additional
1335 information, such as the frame's thread will be added. */
1336 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
1337 /* For the moment there is only one sentinel frame implementation. */
1338 frame
->unwind
= &sentinel_frame_unwind
;
1339 /* Link this frame back to itself. The frame is self referential
1340 (the unwound PC is the same as the pc), so make it so. */
1341 frame
->next
= frame
;
1342 /* Make the sentinel frame's ID valid, but invalid. That way all
1343 comparisons with it should fail. */
1344 frame
->this_id
.p
= 1;
1345 frame
->this_id
.value
= null_frame_id
;
1348 fprintf_unfiltered (gdb_stdlog
, "{ create_sentinel_frame (...) -> ");
1349 fprint_frame (gdb_stdlog
, frame
);
1350 fprintf_unfiltered (gdb_stdlog
, " }\n");
1355 /* Info about the innermost stack frame (contents of FP register). */
1357 static struct frame_info
*current_frame
;
1359 /* Cache for frame addresses already read by gdb. Valid only while
1360 inferior is stopped. Control variables for the frame cache should
1361 be local to this module. */
1363 static struct obstack frame_cache_obstack
;
1366 frame_obstack_zalloc (unsigned long size
)
1368 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
1370 memset (data
, 0, size
);
1374 /* Return the innermost (currently executing) stack frame. This is
1375 split into two functions. The function unwind_to_current_frame()
1376 is wrapped in catch exceptions so that, even when the unwind of the
1377 sentinel frame fails, the function still returns a stack frame. */
1380 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
1382 struct frame_info
*frame
= get_prev_frame (args
);
1384 /* A sentinel frame can fail to unwind, e.g., because its PC value
1385 lands in somewhere like start. */
1388 current_frame
= frame
;
1393 get_current_frame (void)
1395 /* First check, and report, the lack of registers. Having GDB
1396 report "No stack!" or "No memory" when the target doesn't even
1397 have registers is very confusing. Besides, "printcmd.exp"
1398 explicitly checks that ``print $pc'' with no registers prints "No
1400 if (!target_has_registers
)
1401 error (_("No registers."));
1402 if (!target_has_stack
)
1403 error (_("No stack."));
1404 if (!target_has_memory
)
1405 error (_("No memory."));
1406 /* Traceframes are effectively a substitute for the live inferior. */
1407 if (get_traceframe_number () < 0)
1409 if (ptid_equal (inferior_ptid
, null_ptid
))
1410 error (_("No selected thread."));
1411 if (is_exited (inferior_ptid
))
1412 error (_("Invalid selected thread."));
1413 if (is_executing (inferior_ptid
))
1414 error (_("Target is executing."));
1417 if (current_frame
== NULL
)
1419 struct frame_info
*sentinel_frame
=
1420 create_sentinel_frame (current_program_space
, get_current_regcache ());
1421 if (catch_exceptions (current_uiout
, unwind_to_current_frame
,
1422 sentinel_frame
, RETURN_MASK_ERROR
) != 0)
1424 /* Oops! Fake a current frame? Is this useful? It has a PC
1425 of zero, for instance. */
1426 current_frame
= sentinel_frame
;
1429 return current_frame
;
1432 /* The "selected" stack frame is used by default for local and arg
1433 access. May be zero, for no selected frame. */
1435 static struct frame_info
*selected_frame
;
1438 has_stack_frames (void)
1440 if (!target_has_registers
|| !target_has_stack
|| !target_has_memory
)
1443 /* Traceframes are effectively a substitute for the live inferior. */
1444 if (get_traceframe_number () < 0)
1446 /* No current inferior, no frame. */
1447 if (ptid_equal (inferior_ptid
, null_ptid
))
1450 /* Don't try to read from a dead thread. */
1451 if (is_exited (inferior_ptid
))
1454 /* ... or from a spinning thread. */
1455 if (is_executing (inferior_ptid
))
1462 /* Return the selected frame. Always non-NULL (unless there isn't an
1463 inferior sufficient for creating a frame) in which case an error is
1467 get_selected_frame (const char *message
)
1469 if (selected_frame
== NULL
)
1471 if (message
!= NULL
&& !has_stack_frames ())
1472 error (("%s"), message
);
1473 /* Hey! Don't trust this. It should really be re-finding the
1474 last selected frame of the currently selected thread. This,
1475 though, is better than nothing. */
1476 select_frame (get_current_frame ());
1478 /* There is always a frame. */
1479 gdb_assert (selected_frame
!= NULL
);
1480 return selected_frame
;
1483 /* If there is a selected frame, return it. Otherwise, return NULL. */
1486 get_selected_frame_if_set (void)
1488 return selected_frame
;
1491 /* This is a variant of get_selected_frame() which can be called when
1492 the inferior does not have a frame; in that case it will return
1493 NULL instead of calling error(). */
1496 deprecated_safe_get_selected_frame (void)
1498 if (!has_stack_frames ())
1500 return get_selected_frame (NULL
);
1503 /* Select frame FI (or NULL - to invalidate the current frame). */
1506 select_frame (struct frame_info
*fi
)
1508 selected_frame
= fi
;
1509 /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
1510 frame is being invalidated. */
1511 if (deprecated_selected_frame_level_changed_hook
)
1512 deprecated_selected_frame_level_changed_hook (frame_relative_level (fi
));
1514 /* FIXME: kseitz/2002-08-28: It would be nice to call
1515 selected_frame_level_changed_event() right here, but due to limitations
1516 in the current interfaces, we would end up flooding UIs with events
1517 because select_frame() is used extensively internally.
1519 Once we have frame-parameterized frame (and frame-related) commands,
1520 the event notification can be moved here, since this function will only
1521 be called when the user's selected frame is being changed. */
1523 /* Ensure that symbols for this frame are read in. Also, determine the
1524 source language of this frame, and switch to it if desired. */
1529 /* We retrieve the frame's symtab by using the frame PC.
1530 However we cannot use the frame PC as-is, because it usually
1531 points to the instruction following the "call", which is
1532 sometimes the first instruction of another function. So we
1533 rely on get_frame_address_in_block() which provides us with a
1534 PC which is guaranteed to be inside the frame's code
1536 if (get_frame_address_in_block_if_available (fi
, &pc
))
1538 struct symtab
*s
= find_pc_symtab (pc
);
1541 && s
->language
!= current_language
->la_language
1542 && s
->language
!= language_unknown
1543 && language_mode
== language_mode_auto
)
1544 set_language (s
->language
);
1549 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
1550 Always returns a non-NULL value. */
1553 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
1555 struct frame_info
*fi
;
1559 fprintf_unfiltered (gdb_stdlog
,
1560 "{ create_new_frame (addr=%s, pc=%s) ",
1561 hex_string (addr
), hex_string (pc
));
1564 fi
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1566 fi
->next
= create_sentinel_frame (current_program_space
,
1567 get_current_regcache ());
1569 /* Set/update this frame's cached PC value, found in the next frame.
1570 Do this before looking for this frame's unwinder. A sniffer is
1571 very likely to read this, and the corresponding unwinder is
1572 entitled to rely that the PC doesn't magically change. */
1573 fi
->next
->prev_pc
.value
= pc
;
1574 fi
->next
->prev_pc
.p
= 1;
1576 /* We currently assume that frame chain's can't cross spaces. */
1577 fi
->pspace
= fi
->next
->pspace
;
1578 fi
->aspace
= fi
->next
->aspace
;
1580 /* Select/initialize both the unwind function and the frame's type
1582 frame_unwind_find_by_frame (fi
, &fi
->prologue_cache
);
1585 fi
->this_id
.value
= frame_id_build (addr
, pc
);
1589 fprintf_unfiltered (gdb_stdlog
, "-> ");
1590 fprint_frame (gdb_stdlog
, fi
);
1591 fprintf_unfiltered (gdb_stdlog
, " }\n");
1597 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
1598 innermost frame). Be careful to not fall off the bottom of the
1599 frame chain and onto the sentinel frame. */
1602 get_next_frame (struct frame_info
*this_frame
)
1604 if (this_frame
->level
> 0)
1605 return this_frame
->next
;
1610 /* Observer for the target_changed event. */
1613 frame_observer_target_changed (struct target_ops
*target
)
1615 reinit_frame_cache ();
1618 /* Flush the entire frame cache. */
1621 reinit_frame_cache (void)
1623 struct frame_info
*fi
;
1625 /* Tear down all frame caches. */
1626 for (fi
= current_frame
; fi
!= NULL
; fi
= fi
->prev
)
1628 if (fi
->prologue_cache
&& fi
->unwind
->dealloc_cache
)
1629 fi
->unwind
->dealloc_cache (fi
, fi
->prologue_cache
);
1630 if (fi
->base_cache
&& fi
->base
->unwind
->dealloc_cache
)
1631 fi
->base
->unwind
->dealloc_cache (fi
, fi
->base_cache
);
1634 /* Since we can't really be sure what the first object allocated was. */
1635 obstack_free (&frame_cache_obstack
, 0);
1636 obstack_init (&frame_cache_obstack
);
1638 if (current_frame
!= NULL
)
1639 annotate_frames_invalid ();
1641 current_frame
= NULL
; /* Invalidate cache */
1642 select_frame (NULL
);
1643 frame_stash_invalidate ();
1645 fprintf_unfiltered (gdb_stdlog
, "{ reinit_frame_cache () }\n");
1648 /* Find where a register is saved (in memory or another register).
1649 The result of frame_register_unwind is just where it is saved
1650 relative to this particular frame. */
1653 frame_register_unwind_location (struct frame_info
*this_frame
, int regnum
,
1654 int *optimizedp
, enum lval_type
*lvalp
,
1655 CORE_ADDR
*addrp
, int *realnump
)
1657 gdb_assert (this_frame
== NULL
|| this_frame
->level
>= 0);
1659 while (this_frame
!= NULL
)
1663 frame_register_unwind (this_frame
, regnum
, optimizedp
, &unavailable
,
1664 lvalp
, addrp
, realnump
, NULL
);
1669 if (*lvalp
!= lval_register
)
1673 this_frame
= get_next_frame (this_frame
);
1677 /* Get the previous raw frame, and check that it is not identical to
1678 same other frame frame already in the chain. If it is, there is
1679 most likely a stack cycle, so we discard it, and mark THIS_FRAME as
1680 outermost, with UNWIND_SAME_ID stop reason. Unlike the other
1681 validity tests, that compare THIS_FRAME and the next frame, we do
1682 this right after creating the previous frame, to avoid ever ending
1683 up with two frames with the same id in the frame chain. */
1685 static struct frame_info
*
1686 get_prev_frame_if_no_cycle (struct frame_info
*this_frame
)
1688 struct frame_info
*prev_frame
;
1690 prev_frame
= get_prev_frame_raw (this_frame
);
1691 if (prev_frame
== NULL
)
1694 compute_frame_id (prev_frame
);
1695 if (frame_stash_add (prev_frame
))
1698 /* Another frame with the same id was already in the stash. We just
1699 detected a cycle. */
1702 fprintf_unfiltered (gdb_stdlog
, "-> ");
1703 fprint_frame (gdb_stdlog
, NULL
);
1704 fprintf_unfiltered (gdb_stdlog
, " // this frame has same ID }\n");
1706 this_frame
->stop_reason
= UNWIND_SAME_ID
;
1708 prev_frame
->next
= NULL
;
1709 this_frame
->prev
= NULL
;
1713 /* Return a "struct frame_info" corresponding to the frame that called
1714 THIS_FRAME. Returns NULL if there is no such frame.
1716 Unlike get_prev_frame, this function always tries to unwind the
1719 static struct frame_info
*
1720 get_prev_frame_1 (struct frame_info
*this_frame
)
1722 struct frame_id this_id
;
1723 struct gdbarch
*gdbarch
;
1725 gdb_assert (this_frame
!= NULL
);
1726 gdbarch
= get_frame_arch (this_frame
);
1730 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame_1 (this_frame=");
1731 if (this_frame
!= NULL
)
1732 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1734 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1735 fprintf_unfiltered (gdb_stdlog
, ") ");
1738 /* Only try to do the unwind once. */
1739 if (this_frame
->prev_p
)
1743 fprintf_unfiltered (gdb_stdlog
, "-> ");
1744 fprint_frame (gdb_stdlog
, this_frame
->prev
);
1745 fprintf_unfiltered (gdb_stdlog
, " // cached \n");
1747 return this_frame
->prev
;
1750 /* If the frame unwinder hasn't been selected yet, we must do so
1751 before setting prev_p; otherwise the check for misbehaved
1752 sniffers will think that this frame's sniffer tried to unwind
1753 further (see frame_cleanup_after_sniffer). */
1754 if (this_frame
->unwind
== NULL
)
1755 frame_unwind_find_by_frame (this_frame
, &this_frame
->prologue_cache
);
1757 this_frame
->prev_p
= 1;
1758 this_frame
->stop_reason
= UNWIND_NO_REASON
;
1760 /* If we are unwinding from an inline frame, all of the below tests
1761 were already performed when we unwound from the next non-inline
1762 frame. We must skip them, since we can not get THIS_FRAME's ID
1763 until we have unwound all the way down to the previous non-inline
1765 if (get_frame_type (this_frame
) == INLINE_FRAME
)
1766 return get_prev_frame_if_no_cycle (this_frame
);
1768 /* Check that this frame is unwindable. If it isn't, don't try to
1769 unwind to the prev frame. */
1770 this_frame
->stop_reason
1771 = this_frame
->unwind
->stop_reason (this_frame
,
1772 &this_frame
->prologue_cache
);
1774 if (this_frame
->stop_reason
!= UNWIND_NO_REASON
)
1778 enum unwind_stop_reason reason
= this_frame
->stop_reason
;
1780 fprintf_unfiltered (gdb_stdlog
, "-> ");
1781 fprint_frame (gdb_stdlog
, NULL
);
1782 fprintf_unfiltered (gdb_stdlog
, " // %s }\n",
1783 frame_stop_reason_symbol_string (reason
));
1788 /* Check that this frame's ID isn't inner to (younger, below, next)
1789 the next frame. This happens when a frame unwind goes backwards.
1790 This check is valid only if this frame and the next frame are NORMAL.
1791 See the comment at frame_id_inner for details. */
1792 if (get_frame_type (this_frame
) == NORMAL_FRAME
1793 && this_frame
->next
->unwind
->type
== NORMAL_FRAME
1794 && frame_id_inner (get_frame_arch (this_frame
->next
), this_id
,
1795 get_frame_id (this_frame
->next
)))
1797 CORE_ADDR this_pc_in_block
;
1798 struct minimal_symbol
*morestack_msym
;
1799 const char *morestack_name
= NULL
;
1801 /* gcc -fsplit-stack __morestack can continue the stack anywhere. */
1802 this_pc_in_block
= get_frame_address_in_block (this_frame
);
1803 morestack_msym
= lookup_minimal_symbol_by_pc (this_pc_in_block
).minsym
;
1805 morestack_name
= SYMBOL_LINKAGE_NAME (morestack_msym
);
1806 if (!morestack_name
|| strcmp (morestack_name
, "__morestack") != 0)
1810 fprintf_unfiltered (gdb_stdlog
, "-> ");
1811 fprint_frame (gdb_stdlog
, NULL
);
1812 fprintf_unfiltered (gdb_stdlog
,
1813 " // this frame ID is inner }\n");
1815 this_frame
->stop_reason
= UNWIND_INNER_ID
;
1820 /* Check that this and the next frame do not unwind the PC register
1821 to the same memory location. If they do, then even though they
1822 have different frame IDs, the new frame will be bogus; two
1823 functions can't share a register save slot for the PC. This can
1824 happen when the prologue analyzer finds a stack adjustment, but
1827 This check does assume that the "PC register" is roughly a
1828 traditional PC, even if the gdbarch_unwind_pc method adjusts
1829 it (we do not rely on the value, only on the unwound PC being
1830 dependent on this value). A potential improvement would be
1831 to have the frame prev_pc method and the gdbarch unwind_pc
1832 method set the same lval and location information as
1833 frame_register_unwind. */
1834 if (this_frame
->level
> 0
1835 && gdbarch_pc_regnum (gdbarch
) >= 0
1836 && get_frame_type (this_frame
) == NORMAL_FRAME
1837 && (get_frame_type (this_frame
->next
) == NORMAL_FRAME
1838 || get_frame_type (this_frame
->next
) == INLINE_FRAME
))
1840 int optimized
, realnum
, nrealnum
;
1841 enum lval_type lval
, nlval
;
1842 CORE_ADDR addr
, naddr
;
1844 frame_register_unwind_location (this_frame
,
1845 gdbarch_pc_regnum (gdbarch
),
1846 &optimized
, &lval
, &addr
, &realnum
);
1847 frame_register_unwind_location (get_next_frame (this_frame
),
1848 gdbarch_pc_regnum (gdbarch
),
1849 &optimized
, &nlval
, &naddr
, &nrealnum
);
1851 if ((lval
== lval_memory
&& lval
== nlval
&& addr
== naddr
)
1852 || (lval
== lval_register
&& lval
== nlval
&& realnum
== nrealnum
))
1856 fprintf_unfiltered (gdb_stdlog
, "-> ");
1857 fprint_frame (gdb_stdlog
, NULL
);
1858 fprintf_unfiltered (gdb_stdlog
, " // no saved PC }\n");
1861 this_frame
->stop_reason
= UNWIND_NO_SAVED_PC
;
1862 this_frame
->prev
= NULL
;
1867 return get_prev_frame_if_no_cycle (this_frame
);
1870 /* Construct a new "struct frame_info" and link it previous to
1873 static struct frame_info
*
1874 get_prev_frame_raw (struct frame_info
*this_frame
)
1876 struct frame_info
*prev_frame
;
1878 /* Allocate the new frame but do not wire it in to the frame chain.
1879 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1880 frame->next to pull some fancy tricks (of course such code is, by
1881 definition, recursive). Try to prevent it.
1883 There is no reason to worry about memory leaks, should the
1884 remainder of the function fail. The allocated memory will be
1885 quickly reclaimed when the frame cache is flushed, and the `we've
1886 been here before' check above will stop repeated memory
1887 allocation calls. */
1888 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1889 prev_frame
->level
= this_frame
->level
+ 1;
1891 /* For now, assume we don't have frame chains crossing address
1893 prev_frame
->pspace
= this_frame
->pspace
;
1894 prev_frame
->aspace
= this_frame
->aspace
;
1896 /* Don't yet compute ->unwind (and hence ->type). It is computed
1897 on-demand in get_frame_type, frame_register_unwind, and
1900 /* Don't yet compute the frame's ID. It is computed on-demand by
1903 /* The unwound frame ID is validate at the start of this function,
1904 as part of the logic to decide if that frame should be further
1905 unwound, and not here while the prev frame is being created.
1906 Doing this makes it possible for the user to examine a frame that
1907 has an invalid frame ID.
1909 Some very old VAX code noted: [...] For the sake of argument,
1910 suppose that the stack is somewhat trashed (which is one reason
1911 that "info frame" exists). So, return 0 (indicating we don't
1912 know the address of the arglist) if we don't know what frame this
1916 this_frame
->prev
= prev_frame
;
1917 prev_frame
->next
= this_frame
;
1921 fprintf_unfiltered (gdb_stdlog
, "-> ");
1922 fprint_frame (gdb_stdlog
, prev_frame
);
1923 fprintf_unfiltered (gdb_stdlog
, " }\n");
1929 /* Debug routine to print a NULL frame being returned. */
1932 frame_debug_got_null_frame (struct frame_info
*this_frame
,
1937 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame (this_frame=");
1938 if (this_frame
!= NULL
)
1939 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1941 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1942 fprintf_unfiltered (gdb_stdlog
, ") -> // %s}\n", reason
);
1946 /* Is this (non-sentinel) frame in the "main"() function? */
1949 inside_main_func (struct frame_info
*this_frame
)
1951 struct minimal_symbol
*msymbol
;
1954 if (symfile_objfile
== 0)
1956 msymbol
= lookup_minimal_symbol (main_name (), NULL
, symfile_objfile
);
1957 if (msymbol
== NULL
)
1959 /* Make certain that the code, and not descriptor, address is
1961 maddr
= gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame
),
1962 SYMBOL_VALUE_ADDRESS (msymbol
),
1964 return maddr
== get_frame_func (this_frame
);
1967 /* Test whether THIS_FRAME is inside the process entry point function. */
1970 inside_entry_func (struct frame_info
*this_frame
)
1972 CORE_ADDR entry_point
;
1974 if (!entry_point_address_query (&entry_point
))
1977 return get_frame_func (this_frame
) == entry_point
;
1980 /* Return a structure containing various interesting information about
1981 the frame that called THIS_FRAME. Returns NULL if there is entier
1982 no such frame or the frame fails any of a set of target-independent
1983 condition that should terminate the frame chain (e.g., as unwinding
1986 This function should not contain target-dependent tests, such as
1987 checking whether the program-counter is zero. */
1990 get_prev_frame (struct frame_info
*this_frame
)
1995 /* There is always a frame. If this assertion fails, suspect that
1996 something should be calling get_selected_frame() or
1997 get_current_frame(). */
1998 gdb_assert (this_frame
!= NULL
);
1999 frame_pc_p
= get_frame_pc_if_available (this_frame
, &frame_pc
);
2001 /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much
2002 sense to stop unwinding at a dummy frame. One place where a dummy
2003 frame may have an address "inside_main_func" is on HPUX. On HPUX, the
2004 pcsqh register (space register for the instruction at the head of the
2005 instruction queue) cannot be written directly; the only way to set it
2006 is to branch to code that is in the target space. In order to implement
2007 frame dummies on HPUX, the called function is made to jump back to where
2008 the inferior was when the user function was called. If gdb was inside
2009 the main function when we created the dummy frame, the dummy frame will
2010 point inside the main function. */
2011 if (this_frame
->level
>= 0
2012 && get_frame_type (this_frame
) == NORMAL_FRAME
2013 && !backtrace_past_main
2015 && inside_main_func (this_frame
))
2016 /* Don't unwind past main(). Note, this is done _before_ the
2017 frame has been marked as previously unwound. That way if the
2018 user later decides to enable unwinds past main(), that will
2019 automatically happen. */
2021 frame_debug_got_null_frame (this_frame
, "inside main func");
2025 /* If the user's backtrace limit has been exceeded, stop. We must
2026 add two to the current level; one of those accounts for backtrace_limit
2027 being 1-based and the level being 0-based, and the other accounts for
2028 the level of the new frame instead of the level of the current
2030 if (this_frame
->level
+ 2 > backtrace_limit
)
2032 frame_debug_got_null_frame (this_frame
, "backtrace limit exceeded");
2036 /* If we're already inside the entry function for the main objfile,
2037 then it isn't valid. Don't apply this test to a dummy frame -
2038 dummy frame PCs typically land in the entry func. Don't apply
2039 this test to the sentinel frame. Sentinel frames should always
2040 be allowed to unwind. */
2041 /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
2042 wasn't checking for "main" in the minimal symbols. With that
2043 fixed asm-source tests now stop in "main" instead of halting the
2044 backtrace in weird and wonderful ways somewhere inside the entry
2045 file. Suspect that tests for inside the entry file/func were
2046 added to work around that (now fixed) case. */
2047 /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
2048 suggested having the inside_entry_func test use the
2049 inside_main_func() msymbol trick (along with entry_point_address()
2050 I guess) to determine the address range of the start function.
2051 That should provide a far better stopper than the current
2053 /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler
2054 applied tail-call optimizations to main so that a function called
2055 from main returns directly to the caller of main. Since we don't
2056 stop at main, we should at least stop at the entry point of the
2058 if (this_frame
->level
>= 0
2059 && get_frame_type (this_frame
) == NORMAL_FRAME
2060 && !backtrace_past_entry
2062 && inside_entry_func (this_frame
))
2064 frame_debug_got_null_frame (this_frame
, "inside entry func");
2068 /* Assume that the only way to get a zero PC is through something
2069 like a SIGSEGV or a dummy frame, and hence that NORMAL frames
2070 will never unwind a zero PC. */
2071 if (this_frame
->level
> 0
2072 && (get_frame_type (this_frame
) == NORMAL_FRAME
2073 || get_frame_type (this_frame
) == INLINE_FRAME
)
2074 && get_frame_type (get_next_frame (this_frame
)) == NORMAL_FRAME
2075 && frame_pc_p
&& frame_pc
== 0)
2077 frame_debug_got_null_frame (this_frame
, "zero PC");
2081 return get_prev_frame_1 (this_frame
);
2085 get_frame_pc (struct frame_info
*frame
)
2087 gdb_assert (frame
->next
!= NULL
);
2088 return frame_unwind_pc (frame
->next
);
2092 get_frame_pc_if_available (struct frame_info
*frame
, CORE_ADDR
*pc
)
2094 volatile struct gdb_exception ex
;
2096 gdb_assert (frame
->next
!= NULL
);
2098 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2100 *pc
= frame_unwind_pc (frame
->next
);
2104 if (ex
.error
== NOT_AVAILABLE_ERROR
)
2107 throw_exception (ex
);
2113 /* Return an address that falls within THIS_FRAME's code block. */
2116 get_frame_address_in_block (struct frame_info
*this_frame
)
2118 /* A draft address. */
2119 CORE_ADDR pc
= get_frame_pc (this_frame
);
2121 struct frame_info
*next_frame
= this_frame
->next
;
2123 /* Calling get_frame_pc returns the resume address for THIS_FRAME.
2124 Normally the resume address is inside the body of the function
2125 associated with THIS_FRAME, but there is a special case: when
2126 calling a function which the compiler knows will never return
2127 (for instance abort), the call may be the very last instruction
2128 in the calling function. The resume address will point after the
2129 call and may be at the beginning of a different function
2132 If THIS_FRAME is a signal frame or dummy frame, then we should
2133 not adjust the unwound PC. For a dummy frame, GDB pushed the
2134 resume address manually onto the stack. For a signal frame, the
2135 OS may have pushed the resume address manually and invoked the
2136 handler (e.g. GNU/Linux), or invoked the trampoline which called
2137 the signal handler - but in either case the signal handler is
2138 expected to return to the trampoline. So in both of these
2139 cases we know that the resume address is executable and
2140 related. So we only need to adjust the PC if THIS_FRAME
2141 is a normal function.
2143 If the program has been interrupted while THIS_FRAME is current,
2144 then clearly the resume address is inside the associated
2145 function. There are three kinds of interruption: debugger stop
2146 (next frame will be SENTINEL_FRAME), operating system
2147 signal or exception (next frame will be SIGTRAMP_FRAME),
2148 or debugger-induced function call (next frame will be
2149 DUMMY_FRAME). So we only need to adjust the PC if
2150 NEXT_FRAME is a normal function.
2152 We check the type of NEXT_FRAME first, since it is already
2153 known; frame type is determined by the unwinder, and since
2154 we have THIS_FRAME we've already selected an unwinder for
2157 If the next frame is inlined, we need to keep going until we find
2158 the real function - for instance, if a signal handler is invoked
2159 while in an inlined function, then the code address of the
2160 "calling" normal function should not be adjusted either. */
2162 while (get_frame_type (next_frame
) == INLINE_FRAME
)
2163 next_frame
= next_frame
->next
;
2165 if ((get_frame_type (next_frame
) == NORMAL_FRAME
2166 || get_frame_type (next_frame
) == TAILCALL_FRAME
)
2167 && (get_frame_type (this_frame
) == NORMAL_FRAME
2168 || get_frame_type (this_frame
) == TAILCALL_FRAME
2169 || get_frame_type (this_frame
) == INLINE_FRAME
))
2176 get_frame_address_in_block_if_available (struct frame_info
*this_frame
,
2179 volatile struct gdb_exception ex
;
2181 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2183 *pc
= get_frame_address_in_block (this_frame
);
2185 if (ex
.reason
< 0 && ex
.error
== NOT_AVAILABLE_ERROR
)
2187 else if (ex
.reason
< 0)
2188 throw_exception (ex
);
2194 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
2196 struct frame_info
*next_frame
;
2200 /* If the next frame represents an inlined function call, this frame's
2201 sal is the "call site" of that inlined function, which can not
2202 be inferred from get_frame_pc. */
2203 next_frame
= get_next_frame (frame
);
2204 if (frame_inlined_callees (frame
) > 0)
2209 sym
= get_frame_function (next_frame
);
2211 sym
= inline_skipped_symbol (inferior_ptid
);
2213 /* If frame is inline, it certainly has symbols. */
2216 if (SYMBOL_LINE (sym
) != 0)
2218 sal
->symtab
= SYMBOL_SYMTAB (sym
);
2219 sal
->line
= SYMBOL_LINE (sym
);
2222 /* If the symbol does not have a location, we don't know where
2223 the call site is. Do not pretend to. This is jarring, but
2224 we can't do much better. */
2225 sal
->pc
= get_frame_pc (frame
);
2227 sal
->pspace
= get_frame_program_space (frame
);
2232 /* If FRAME is not the innermost frame, that normally means that
2233 FRAME->pc points at the return instruction (which is *after* the
2234 call instruction), and we want to get the line containing the
2235 call (because the call is where the user thinks the program is).
2236 However, if the next frame is either a SIGTRAMP_FRAME or a
2237 DUMMY_FRAME, then the next frame will contain a saved interrupt
2238 PC and such a PC indicates the current (rather than next)
2239 instruction/line, consequently, for such cases, want to get the
2240 line containing fi->pc. */
2241 if (!get_frame_pc_if_available (frame
, &pc
))
2247 notcurrent
= (pc
!= get_frame_address_in_block (frame
));
2248 (*sal
) = find_pc_line (pc
, notcurrent
);
2251 /* Per "frame.h", return the ``address'' of the frame. Code should
2252 really be using get_frame_id(). */
2254 get_frame_base (struct frame_info
*fi
)
2256 return get_frame_id (fi
).stack_addr
;
2259 /* High-level offsets into the frame. Used by the debug info. */
2262 get_frame_base_address (struct frame_info
*fi
)
2264 if (get_frame_type (fi
) != NORMAL_FRAME
)
2266 if (fi
->base
== NULL
)
2267 fi
->base
= frame_base_find_by_frame (fi
);
2268 /* Sneaky: If the low-level unwind and high-level base code share a
2269 common unwinder, let them share the prologue cache. */
2270 if (fi
->base
->unwind
== fi
->unwind
)
2271 return fi
->base
->this_base (fi
, &fi
->prologue_cache
);
2272 return fi
->base
->this_base (fi
, &fi
->base_cache
);
2276 get_frame_locals_address (struct frame_info
*fi
)
2278 if (get_frame_type (fi
) != NORMAL_FRAME
)
2280 /* If there isn't a frame address method, find it. */
2281 if (fi
->base
== NULL
)
2282 fi
->base
= frame_base_find_by_frame (fi
);
2283 /* Sneaky: If the low-level unwind and high-level base code share a
2284 common unwinder, let them share the prologue cache. */
2285 if (fi
->base
->unwind
== fi
->unwind
)
2286 return fi
->base
->this_locals (fi
, &fi
->prologue_cache
);
2287 return fi
->base
->this_locals (fi
, &fi
->base_cache
);
2291 get_frame_args_address (struct frame_info
*fi
)
2293 if (get_frame_type (fi
) != NORMAL_FRAME
)
2295 /* If there isn't a frame address method, find it. */
2296 if (fi
->base
== NULL
)
2297 fi
->base
= frame_base_find_by_frame (fi
);
2298 /* Sneaky: If the low-level unwind and high-level base code share a
2299 common unwinder, let them share the prologue cache. */
2300 if (fi
->base
->unwind
== fi
->unwind
)
2301 return fi
->base
->this_args (fi
, &fi
->prologue_cache
);
2302 return fi
->base
->this_args (fi
, &fi
->base_cache
);
2305 /* Return true if the frame unwinder for frame FI is UNWINDER; false
2309 frame_unwinder_is (struct frame_info
*fi
, const struct frame_unwind
*unwinder
)
2311 if (fi
->unwind
== NULL
)
2312 frame_unwind_find_by_frame (fi
, &fi
->prologue_cache
);
2313 return fi
->unwind
== unwinder
;
2316 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
2317 or -1 for a NULL frame. */
2320 frame_relative_level (struct frame_info
*fi
)
2329 get_frame_type (struct frame_info
*frame
)
2331 if (frame
->unwind
== NULL
)
2332 /* Initialize the frame's unwinder because that's what
2333 provides the frame's type. */
2334 frame_unwind_find_by_frame (frame
, &frame
->prologue_cache
);
2335 return frame
->unwind
->type
;
2338 struct program_space
*
2339 get_frame_program_space (struct frame_info
*frame
)
2341 return frame
->pspace
;
2344 struct program_space
*
2345 frame_unwind_program_space (struct frame_info
*this_frame
)
2347 gdb_assert (this_frame
);
2349 /* This is really a placeholder to keep the API consistent --- we
2350 assume for now that we don't have frame chains crossing
2352 return this_frame
->pspace
;
2355 struct address_space
*
2356 get_frame_address_space (struct frame_info
*frame
)
2358 return frame
->aspace
;
2361 /* Memory access methods. */
2364 get_frame_memory (struct frame_info
*this_frame
, CORE_ADDR addr
,
2365 gdb_byte
*buf
, int len
)
2367 read_memory (addr
, buf
, len
);
2371 get_frame_memory_signed (struct frame_info
*this_frame
, CORE_ADDR addr
,
2374 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
2375 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
2377 return read_memory_integer (addr
, len
, byte_order
);
2381 get_frame_memory_unsigned (struct frame_info
*this_frame
, CORE_ADDR addr
,
2384 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
2385 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
2387 return read_memory_unsigned_integer (addr
, len
, byte_order
);
2391 safe_frame_unwind_memory (struct frame_info
*this_frame
,
2392 CORE_ADDR addr
, gdb_byte
*buf
, int len
)
2394 /* NOTE: target_read_memory returns zero on success! */
2395 return !target_read_memory (addr
, buf
, len
);
2398 /* Architecture methods. */
2401 get_frame_arch (struct frame_info
*this_frame
)
2403 return frame_unwind_arch (this_frame
->next
);
2407 frame_unwind_arch (struct frame_info
*next_frame
)
2409 if (!next_frame
->prev_arch
.p
)
2411 struct gdbarch
*arch
;
2413 if (next_frame
->unwind
== NULL
)
2414 frame_unwind_find_by_frame (next_frame
, &next_frame
->prologue_cache
);
2416 if (next_frame
->unwind
->prev_arch
!= NULL
)
2417 arch
= next_frame
->unwind
->prev_arch (next_frame
,
2418 &next_frame
->prologue_cache
);
2420 arch
= get_frame_arch (next_frame
);
2422 next_frame
->prev_arch
.arch
= arch
;
2423 next_frame
->prev_arch
.p
= 1;
2425 fprintf_unfiltered (gdb_stdlog
,
2426 "{ frame_unwind_arch (next_frame=%d) -> %s }\n",
2428 gdbarch_bfd_arch_info (arch
)->printable_name
);
2431 return next_frame
->prev_arch
.arch
;
2435 frame_unwind_caller_arch (struct frame_info
*next_frame
)
2437 return frame_unwind_arch (skip_artificial_frames (next_frame
));
2440 /* Stack pointer methods. */
2443 get_frame_sp (struct frame_info
*this_frame
)
2445 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
2447 /* Normality - an architecture that provides a way of obtaining any
2448 frame inner-most address. */
2449 if (gdbarch_unwind_sp_p (gdbarch
))
2450 /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to
2451 operate on THIS_FRAME now. */
2452 return gdbarch_unwind_sp (gdbarch
, this_frame
->next
);
2453 /* Now things are really are grim. Hope that the value returned by
2454 the gdbarch_sp_regnum register is meaningful. */
2455 if (gdbarch_sp_regnum (gdbarch
) >= 0)
2456 return get_frame_register_unsigned (this_frame
,
2457 gdbarch_sp_regnum (gdbarch
));
2458 internal_error (__FILE__
, __LINE__
, _("Missing unwind SP method"));
2461 /* Return the reason why we can't unwind past FRAME. */
2463 enum unwind_stop_reason
2464 get_frame_unwind_stop_reason (struct frame_info
*frame
)
2466 /* If we haven't tried to unwind past this point yet, then assume
2467 that unwinding would succeed. */
2468 if (frame
->prev_p
== 0)
2469 return UNWIND_NO_REASON
;
2471 /* Otherwise, we set a reason when we succeeded (or failed) to
2473 return frame
->stop_reason
;
2476 /* Return a string explaining REASON. */
2479 frame_stop_reason_string (enum unwind_stop_reason reason
)
2483 #define SET(name, description) \
2484 case name: return _(description);
2485 #include "unwind_stop_reasons.def"
2489 internal_error (__FILE__
, __LINE__
,
2490 "Invalid frame stop reason");
2494 /* Return the enum symbol name of REASON as a string, to use in debug
2498 frame_stop_reason_symbol_string (enum unwind_stop_reason reason
)
2502 #define SET(name, description) \
2503 case name: return #name;
2504 #include "unwind_stop_reasons.def"
2508 internal_error (__FILE__
, __LINE__
,
2509 "Invalid frame stop reason");
2513 /* Clean up after a failed (wrong unwinder) attempt to unwind past
2517 frame_cleanup_after_sniffer (void *arg
)
2519 struct frame_info
*frame
= arg
;
2521 /* The sniffer should not allocate a prologue cache if it did not
2522 match this frame. */
2523 gdb_assert (frame
->prologue_cache
== NULL
);
2525 /* No sniffer should extend the frame chain; sniff based on what is
2527 gdb_assert (!frame
->prev_p
);
2529 /* The sniffer should not check the frame's ID; that's circular. */
2530 gdb_assert (!frame
->this_id
.p
);
2532 /* Clear cached fields dependent on the unwinder.
2534 The previous PC is independent of the unwinder, but the previous
2535 function is not (see get_frame_address_in_block). */
2536 frame
->prev_func
.p
= 0;
2537 frame
->prev_func
.addr
= 0;
2539 /* Discard the unwinder last, so that we can easily find it if an assertion
2540 in this function triggers. */
2541 frame
->unwind
= NULL
;
2544 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
2545 Return a cleanup which should be called if unwinding fails, and
2546 discarded if it succeeds. */
2549 frame_prepare_for_sniffer (struct frame_info
*frame
,
2550 const struct frame_unwind
*unwind
)
2552 gdb_assert (frame
->unwind
== NULL
);
2553 frame
->unwind
= unwind
;
2554 return make_cleanup (frame_cleanup_after_sniffer
, frame
);
2557 extern initialize_file_ftype _initialize_frame
; /* -Wmissing-prototypes */
2559 static struct cmd_list_element
*set_backtrace_cmdlist
;
2560 static struct cmd_list_element
*show_backtrace_cmdlist
;
2563 set_backtrace_cmd (char *args
, int from_tty
)
2565 help_list (set_backtrace_cmdlist
, "set backtrace ", -1, gdb_stdout
);
2569 show_backtrace_cmd (char *args
, int from_tty
)
2571 cmd_show_list (show_backtrace_cmdlist
, from_tty
, "");
2575 _initialize_frame (void)
2577 obstack_init (&frame_cache_obstack
);
2579 frame_stash_create ();
2581 observer_attach_target_changed (frame_observer_target_changed
);
2583 add_prefix_cmd ("backtrace", class_maintenance
, set_backtrace_cmd
, _("\
2584 Set backtrace specific variables.\n\
2585 Configure backtrace variables such as the backtrace limit"),
2586 &set_backtrace_cmdlist
, "set backtrace ",
2587 0/*allow-unknown*/, &setlist
);
2588 add_prefix_cmd ("backtrace", class_maintenance
, show_backtrace_cmd
, _("\
2589 Show backtrace specific variables\n\
2590 Show backtrace variables such as the backtrace limit"),
2591 &show_backtrace_cmdlist
, "show backtrace ",
2592 0/*allow-unknown*/, &showlist
);
2594 add_setshow_boolean_cmd ("past-main", class_obscure
,
2595 &backtrace_past_main
, _("\
2596 Set whether backtraces should continue past \"main\"."), _("\
2597 Show whether backtraces should continue past \"main\"."), _("\
2598 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
2599 the backtrace at \"main\". Set this variable if you need to see the rest\n\
2600 of the stack trace."),
2602 show_backtrace_past_main
,
2603 &set_backtrace_cmdlist
,
2604 &show_backtrace_cmdlist
);
2606 add_setshow_boolean_cmd ("past-entry", class_obscure
,
2607 &backtrace_past_entry
, _("\
2608 Set whether backtraces should continue past the entry point of a program."),
2610 Show whether backtraces should continue past the entry point of a program."),
2612 Normally there are no callers beyond the entry point of a program, so GDB\n\
2613 will terminate the backtrace there. Set this variable if you need to see\n\
2614 the rest of the stack trace."),
2616 show_backtrace_past_entry
,
2617 &set_backtrace_cmdlist
,
2618 &show_backtrace_cmdlist
);
2620 add_setshow_uinteger_cmd ("limit", class_obscure
,
2621 &backtrace_limit
, _("\
2622 Set an upper bound on the number of backtrace levels."), _("\
2623 Show the upper bound on the number of backtrace levels."), _("\
2624 No more than the specified number of frames can be displayed or examined.\n\
2625 Literal \"unlimited\" or zero means no limit."),
2627 show_backtrace_limit
,
2628 &set_backtrace_cmdlist
,
2629 &show_backtrace_cmdlist
);
2631 /* Debug this files internals. */
2632 add_setshow_zuinteger_cmd ("frame", class_maintenance
, &frame_debug
, _("\
2633 Set frame debugging."), _("\
2634 Show frame debugging."), _("\
2635 When non-zero, frame specific internal debugging is enabled."),
2638 &setdebuglist
, &showdebuglist
);