1 /* Cache and manage frames for GDB, the GNU debugger.
3 Copyright (C) 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001,
4 2002, 2003, 2004, 2007, 2008, 2009, 2010, 2011
5 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
26 #include "inferior.h" /* for inferior_ptid */
28 #include "gdb_assert.h"
29 #include "gdb_string.h"
30 #include "user-regs.h"
31 #include "gdb_obstack.h"
32 #include "dummy-frame.h"
33 #include "sentinel-frame.h"
37 #include "frame-unwind.h"
38 #include "frame-base.h"
43 #include "exceptions.h"
44 #include "gdbthread.h"
46 #include "inline-frame.h"
47 #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
);
52 /* We keep a cache of stack frames, each of which is a "struct
53 frame_info". The innermost one gets allocated (in
54 wait_for_inferior) each time the inferior stops; current_frame
55 points to it. Additional frames get allocated (in get_prev_frame)
56 as needed, and are chained through the next and prev fields. Any
57 time that the frame cache becomes invalid (most notably when we
58 execute something, but also if we change how we interpret the
59 frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
60 which reads new symbols)), we should call reinit_frame_cache. */
64 /* Level of this frame. The inner-most (youngest) frame is at level
65 0. As you move towards the outer-most (oldest) frame, the level
66 increases. This is a cached value. It could just as easily be
67 computed by counting back from the selected frame to the inner
69 /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be
70 reserved to indicate a bogus frame - one that has been created
71 just to keep GDB happy (GDB always needs a frame). For the
72 moment leave this as speculation. */
75 /* The frame's program space. */
76 struct program_space
*pspace
;
78 /* The frame's address space. */
79 struct address_space
*aspace
;
81 /* The frame's low-level unwinder and corresponding cache. The
82 low-level unwinder is responsible for unwinding register values
83 for the previous frame. The low-level unwind methods are
84 selected based on the presence, or otherwise, of register unwind
85 information such as CFI. */
87 const struct frame_unwind
*unwind
;
89 /* Cached copy of the previous frame's architecture. */
96 /* Cached copy of the previous frame's resume address. */
102 /* Cached copy of the previous frame's function address. */
109 /* This frame's ID. */
113 struct frame_id value
;
116 /* The frame's high-level base methods, and corresponding cache.
117 The high level base methods are selected based on the frame's
119 const struct frame_base
*base
;
122 /* Pointers to the next (down, inner, younger) and previous (up,
123 outer, older) frame_info's in the frame cache. */
124 struct frame_info
*next
; /* down, inner, younger */
126 struct frame_info
*prev
; /* up, outer, older */
128 /* The reason why we could not set PREV, or UNWIND_NO_REASON if we
129 could. Only valid when PREV_P is set. */
130 enum unwind_stop_reason stop_reason
;
133 /* A frame stash used to speed up frame lookups. */
135 /* We currently only stash one frame at a time, as this seems to be
136 sufficient for now. */
137 static struct frame_info
*frame_stash
= NULL
;
139 /* Add the following FRAME to the frame stash. */
142 frame_stash_add (struct frame_info
*frame
)
147 /* Search the frame stash for an entry with the given frame ID.
148 If found, return that frame. Otherwise return NULL. */
150 static struct frame_info
*
151 frame_stash_find (struct frame_id id
)
153 if (frame_stash
&& frame_id_eq (frame_stash
->this_id
.value
, id
))
159 /* Invalidate the frame stash by removing all entries in it. */
162 frame_stash_invalidate (void)
167 /* Flag to control debugging. */
171 show_frame_debug (struct ui_file
*file
, int from_tty
,
172 struct cmd_list_element
*c
, const char *value
)
174 fprintf_filtered (file
, _("Frame debugging is %s.\n"), value
);
177 /* Flag to indicate whether backtraces should stop at main et.al. */
179 static int backtrace_past_main
;
181 show_backtrace_past_main (struct ui_file
*file
, int from_tty
,
182 struct cmd_list_element
*c
, const char *value
)
184 fprintf_filtered (file
,
185 _("Whether backtraces should "
186 "continue past \"main\" is %s.\n"),
190 static int backtrace_past_entry
;
192 show_backtrace_past_entry (struct ui_file
*file
, int from_tty
,
193 struct cmd_list_element
*c
, const char *value
)
195 fprintf_filtered (file
, _("Whether backtraces should continue past the "
196 "entry point of a program is %s.\n"),
200 static int backtrace_limit
= INT_MAX
;
202 show_backtrace_limit (struct ui_file
*file
, int from_tty
,
203 struct cmd_list_element
*c
, const char *value
)
205 fprintf_filtered (file
,
206 _("An upper bound on the number "
207 "of backtrace levels is %s.\n"),
213 fprint_field (struct ui_file
*file
, const char *name
, int p
, CORE_ADDR addr
)
216 fprintf_unfiltered (file
, "%s=%s", name
, hex_string (addr
));
218 fprintf_unfiltered (file
, "!%s", name
);
222 fprint_frame_id (struct ui_file
*file
, struct frame_id id
)
224 fprintf_unfiltered (file
, "{");
225 fprint_field (file
, "stack", id
.stack_addr_p
, id
.stack_addr
);
226 fprintf_unfiltered (file
, ",");
227 fprint_field (file
, "code", id
.code_addr_p
, id
.code_addr
);
228 fprintf_unfiltered (file
, ",");
229 fprint_field (file
, "special", id
.special_addr_p
, id
.special_addr
);
231 fprintf_unfiltered (file
, ",inlined=%d", id
.inline_depth
);
232 fprintf_unfiltered (file
, "}");
236 fprint_frame_type (struct ui_file
*file
, enum frame_type type
)
241 fprintf_unfiltered (file
, "NORMAL_FRAME");
244 fprintf_unfiltered (file
, "DUMMY_FRAME");
247 fprintf_unfiltered (file
, "INLINE_FRAME");
250 fprintf_unfiltered (file
, "SENTINEL_FRAME");
253 fprintf_unfiltered (file
, "SIGTRAMP_FRAME");
256 fprintf_unfiltered (file
, "ARCH_FRAME");
259 fprintf_unfiltered (file
, "<unknown type>");
265 fprint_frame (struct ui_file
*file
, struct frame_info
*fi
)
269 fprintf_unfiltered (file
, "<NULL frame>");
272 fprintf_unfiltered (file
, "{");
273 fprintf_unfiltered (file
, "level=%d", fi
->level
);
274 fprintf_unfiltered (file
, ",");
275 fprintf_unfiltered (file
, "type=");
276 if (fi
->unwind
!= NULL
)
277 fprint_frame_type (file
, fi
->unwind
->type
);
279 fprintf_unfiltered (file
, "<unknown>");
280 fprintf_unfiltered (file
, ",");
281 fprintf_unfiltered (file
, "unwind=");
282 if (fi
->unwind
!= NULL
)
283 gdb_print_host_address (fi
->unwind
, file
);
285 fprintf_unfiltered (file
, "<unknown>");
286 fprintf_unfiltered (file
, ",");
287 fprintf_unfiltered (file
, "pc=");
288 if (fi
->next
!= NULL
&& fi
->next
->prev_pc
.p
)
289 fprintf_unfiltered (file
, "%s", hex_string (fi
->next
->prev_pc
.value
));
291 fprintf_unfiltered (file
, "<unknown>");
292 fprintf_unfiltered (file
, ",");
293 fprintf_unfiltered (file
, "id=");
295 fprint_frame_id (file
, fi
->this_id
.value
);
297 fprintf_unfiltered (file
, "<unknown>");
298 fprintf_unfiltered (file
, ",");
299 fprintf_unfiltered (file
, "func=");
300 if (fi
->next
!= NULL
&& fi
->next
->prev_func
.p
)
301 fprintf_unfiltered (file
, "%s", hex_string (fi
->next
->prev_func
.addr
));
303 fprintf_unfiltered (file
, "<unknown>");
304 fprintf_unfiltered (file
, "}");
307 /* Given FRAME, return the enclosing normal frame for inlined
308 function frames. Otherwise return the original frame. */
310 static struct frame_info
*
311 skip_inlined_frames (struct frame_info
*frame
)
313 while (get_frame_type (frame
) == INLINE_FRAME
)
314 frame
= get_prev_frame (frame
);
319 /* Return a frame uniq ID that can be used to, later, re-find the
323 get_frame_id (struct frame_info
*fi
)
326 return null_frame_id
;
331 fprintf_unfiltered (gdb_stdlog
, "{ get_frame_id (fi=%d) ",
333 /* Find the unwinder. */
334 if (fi
->unwind
== NULL
)
335 frame_unwind_find_by_frame (fi
, &fi
->prologue_cache
);
336 /* Find THIS frame's ID. */
337 /* Default to outermost if no ID is found. */
338 fi
->this_id
.value
= outer_frame_id
;
339 fi
->unwind
->this_id (fi
, &fi
->prologue_cache
, &fi
->this_id
.value
);
340 gdb_assert (frame_id_p (fi
->this_id
.value
));
344 fprintf_unfiltered (gdb_stdlog
, "-> ");
345 fprint_frame_id (gdb_stdlog
, fi
->this_id
.value
);
346 fprintf_unfiltered (gdb_stdlog
, " }\n");
350 frame_stash_add (fi
);
352 return fi
->this_id
.value
;
356 get_stack_frame_id (struct frame_info
*next_frame
)
358 return get_frame_id (skip_inlined_frames (next_frame
));
362 frame_unwind_caller_id (struct frame_info
*next_frame
)
364 struct frame_info
*this_frame
;
366 /* Use get_prev_frame_1, and not get_prev_frame. The latter will truncate
367 the frame chain, leading to this function unintentionally
368 returning a null_frame_id (e.g., when a caller requests the frame
369 ID of "main()"s caller. */
371 next_frame
= skip_inlined_frames (next_frame
);
372 this_frame
= get_prev_frame_1 (next_frame
);
374 return get_frame_id (skip_inlined_frames (this_frame
));
376 return null_frame_id
;
379 const struct frame_id null_frame_id
; /* All zeros. */
380 const struct frame_id outer_frame_id
= { 0, 0, 0, 0, 0, 1, 0 };
383 frame_id_build_special (CORE_ADDR stack_addr
, CORE_ADDR code_addr
,
384 CORE_ADDR special_addr
)
386 struct frame_id id
= null_frame_id
;
388 id
.stack_addr
= stack_addr
;
390 id
.code_addr
= code_addr
;
392 id
.special_addr
= special_addr
;
393 id
.special_addr_p
= 1;
398 frame_id_build (CORE_ADDR stack_addr
, CORE_ADDR code_addr
)
400 struct frame_id id
= null_frame_id
;
402 id
.stack_addr
= stack_addr
;
404 id
.code_addr
= code_addr
;
410 frame_id_build_wild (CORE_ADDR stack_addr
)
412 struct frame_id id
= null_frame_id
;
414 id
.stack_addr
= stack_addr
;
420 frame_id_p (struct frame_id l
)
424 /* The frame is valid iff it has a valid stack address. */
426 /* outer_frame_id is also valid. */
427 if (!p
&& memcmp (&l
, &outer_frame_id
, sizeof (l
)) == 0)
431 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_p (l=");
432 fprint_frame_id (gdb_stdlog
, l
);
433 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", p
);
439 frame_id_inlined_p (struct frame_id l
)
444 return (l
.inline_depth
!= 0);
448 frame_id_eq (struct frame_id l
, struct frame_id r
)
452 if (!l
.stack_addr_p
&& l
.special_addr_p
453 && !r
.stack_addr_p
&& r
.special_addr_p
)
454 /* The outermost frame marker is equal to itself. This is the
455 dodgy thing about outer_frame_id, since between execution steps
456 we might step into another function - from which we can't
457 unwind either. More thought required to get rid of
460 else if (!l
.stack_addr_p
|| !r
.stack_addr_p
)
461 /* Like a NaN, if either ID is invalid, the result is false.
462 Note that a frame ID is invalid iff it is the null frame ID. */
464 else if (l
.stack_addr
!= r
.stack_addr
)
465 /* If .stack addresses are different, the frames are different. */
467 else if (l
.code_addr_p
&& r
.code_addr_p
&& l
.code_addr
!= r
.code_addr
)
468 /* An invalid code addr is a wild card. If .code addresses are
469 different, the frames are different. */
471 else if (l
.special_addr_p
&& r
.special_addr_p
472 && l
.special_addr
!= r
.special_addr
)
473 /* An invalid special addr is a wild card (or unused). Otherwise
474 if special addresses are different, the frames are different. */
476 else if (l
.inline_depth
!= r
.inline_depth
)
477 /* If inline depths are different, the frames must be different. */
480 /* Frames are equal. */
485 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_eq (l=");
486 fprint_frame_id (gdb_stdlog
, l
);
487 fprintf_unfiltered (gdb_stdlog
, ",r=");
488 fprint_frame_id (gdb_stdlog
, r
);
489 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", eq
);
494 /* Safety net to check whether frame ID L should be inner to
495 frame ID R, according to their stack addresses.
497 This method cannot be used to compare arbitrary frames, as the
498 ranges of valid stack addresses may be discontiguous (e.g. due
501 However, it can be used as safety net to discover invalid frame
502 IDs in certain circumstances. Assuming that NEXT is the immediate
503 inner frame to THIS and that NEXT and THIS are both NORMAL frames:
505 * The stack address of NEXT must be inner-than-or-equal to the stack
508 Therefore, if frame_id_inner (THIS, NEXT) holds, some unwind
511 * If NEXT and THIS have different stack addresses, no other frame
512 in the frame chain may have a stack address in between.
514 Therefore, if frame_id_inner (TEST, THIS) holds, but
515 frame_id_inner (TEST, NEXT) does not hold, TEST cannot refer
516 to a valid frame in the frame chain.
518 The sanity checks above cannot be performed when a SIGTRAMP frame
519 is involved, because signal handlers might be executed on a different
520 stack than the stack used by the routine that caused the signal
521 to be raised. This can happen for instance when a thread exceeds
522 its maximum stack size. In this case, certain compilers implement
523 a stack overflow strategy that cause the handler to be run on a
527 frame_id_inner (struct gdbarch
*gdbarch
, struct frame_id l
, struct frame_id r
)
531 if (!l
.stack_addr_p
|| !r
.stack_addr_p
)
532 /* Like NaN, any operation involving an invalid ID always fails. */
534 else if (l
.inline_depth
> r
.inline_depth
535 && l
.stack_addr
== r
.stack_addr
536 && l
.code_addr_p
== r
.code_addr_p
537 && l
.special_addr_p
== r
.special_addr_p
538 && l
.special_addr
== r
.special_addr
)
540 /* Same function, different inlined functions. */
541 struct block
*lb
, *rb
;
543 gdb_assert (l
.code_addr_p
&& r
.code_addr_p
);
545 lb
= block_for_pc (l
.code_addr
);
546 rb
= block_for_pc (r
.code_addr
);
548 if (lb
== NULL
|| rb
== NULL
)
549 /* Something's gone wrong. */
552 /* This will return true if LB and RB are the same block, or
553 if the block with the smaller depth lexically encloses the
554 block with the greater depth. */
555 inner
= contained_in (lb
, rb
);
558 /* Only return non-zero when strictly inner than. Note that, per
559 comment in "frame.h", there is some fuzz here. Frameless
560 functions are not strictly inner than (same .stack but
561 different .code and/or .special address). */
562 inner
= gdbarch_inner_than (gdbarch
, l
.stack_addr
, r
.stack_addr
);
565 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_inner (l=");
566 fprint_frame_id (gdb_stdlog
, l
);
567 fprintf_unfiltered (gdb_stdlog
, ",r=");
568 fprint_frame_id (gdb_stdlog
, r
);
569 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", inner
);
575 frame_find_by_id (struct frame_id id
)
577 struct frame_info
*frame
, *prev_frame
;
579 /* ZERO denotes the null frame, let the caller decide what to do
580 about it. Should it instead return get_current_frame()? */
581 if (!frame_id_p (id
))
584 /* Try using the frame stash first. Finding it there removes the need
585 to perform the search by looping over all frames, which can be very
586 CPU-intensive if the number of frames is very high (the loop is O(n)
587 and get_prev_frame performs a series of checks that are relatively
588 expensive). This optimization is particularly useful when this function
589 is called from another function (such as value_fetch_lazy, case
590 VALUE_LVAL (val) == lval_register) which already loops over all frames,
591 making the overall behavior O(n^2). */
592 frame
= frame_stash_find (id
);
596 for (frame
= get_current_frame (); ; frame
= prev_frame
)
598 struct frame_id
this = get_frame_id (frame
);
600 if (frame_id_eq (id
, this))
601 /* An exact match. */
604 prev_frame
= get_prev_frame (frame
);
608 /* As a safety net to avoid unnecessary backtracing while trying
609 to find an invalid ID, we check for a common situation where
610 we can detect from comparing stack addresses that no other
611 frame in the current frame chain can have this ID. See the
612 comment at frame_id_inner for details. */
613 if (get_frame_type (frame
) == NORMAL_FRAME
614 && !frame_id_inner (get_frame_arch (frame
), id
, this)
615 && frame_id_inner (get_frame_arch (prev_frame
), id
,
616 get_frame_id (prev_frame
)))
623 frame_unwind_pc_if_available (struct frame_info
*this_frame
, CORE_ADDR
*pc
)
625 if (!this_frame
->prev_pc
.p
)
627 if (gdbarch_unwind_pc_p (frame_unwind_arch (this_frame
)))
629 volatile struct gdb_exception ex
;
630 struct gdbarch
*prev_gdbarch
;
633 /* The right way. The `pure' way. The one true way. This
634 method depends solely on the register-unwind code to
635 determine the value of registers in THIS frame, and hence
636 the value of this frame's PC (resume address). A typical
637 implementation is no more than:
639 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
640 return extract_unsigned_integer (buf, size of ISA_PC_REGNUM);
642 Note: this method is very heavily dependent on a correct
643 register-unwind implementation, it pays to fix that
644 method first; this method is frame type agnostic, since
645 it only deals with register values, it works with any
646 frame. This is all in stark contrast to the old
647 FRAME_SAVED_PC which would try to directly handle all the
648 different ways that a PC could be unwound. */
649 prev_gdbarch
= frame_unwind_arch (this_frame
);
651 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
653 pc
= gdbarch_unwind_pc (prev_gdbarch
, this_frame
);
655 if (ex
.reason
< 0 && ex
.error
== NOT_AVAILABLE_ERROR
)
657 this_frame
->prev_pc
.p
= -1;
660 fprintf_unfiltered (gdb_stdlog
,
661 "{ frame_unwind_pc (this_frame=%d)"
662 " -> <unavailable> }\n",
665 else if (ex
.reason
< 0)
667 throw_exception (ex
);
671 this_frame
->prev_pc
.value
= pc
;
672 this_frame
->prev_pc
.p
= 1;
674 fprintf_unfiltered (gdb_stdlog
,
675 "{ frame_unwind_pc (this_frame=%d) "
678 hex_string (this_frame
->prev_pc
.value
));
682 internal_error (__FILE__
, __LINE__
, _("No unwind_pc method"));
684 if (this_frame
->prev_pc
.p
< 0)
691 *pc
= this_frame
->prev_pc
.value
;
697 frame_unwind_pc (struct frame_info
*this_frame
)
701 if (!frame_unwind_pc_if_available (this_frame
, &pc
))
702 throw_error (NOT_AVAILABLE_ERROR
, _("PC not available"));
708 frame_unwind_caller_pc (struct frame_info
*this_frame
)
710 return frame_unwind_pc (skip_inlined_frames (this_frame
));
714 frame_unwind_caller_pc_if_available (struct frame_info
*this_frame
,
717 return frame_unwind_pc_if_available (skip_inlined_frames (this_frame
), pc
);
721 get_frame_func_if_available (struct frame_info
*this_frame
, CORE_ADDR
*pc
)
723 struct frame_info
*next_frame
= this_frame
->next
;
725 if (!next_frame
->prev_func
.p
)
727 CORE_ADDR addr_in_block
;
729 /* Make certain that this, and not the adjacent, function is
731 if (!get_frame_address_in_block_if_available (this_frame
, &addr_in_block
))
733 next_frame
->prev_func
.p
= -1;
735 fprintf_unfiltered (gdb_stdlog
,
736 "{ get_frame_func (this_frame=%d)"
737 " -> unavailable }\n",
742 next_frame
->prev_func
.p
= 1;
743 next_frame
->prev_func
.addr
= get_pc_function_start (addr_in_block
);
745 fprintf_unfiltered (gdb_stdlog
,
746 "{ get_frame_func (this_frame=%d) -> %s }\n",
748 hex_string (next_frame
->prev_func
.addr
));
752 if (next_frame
->prev_func
.p
< 0)
759 *pc
= next_frame
->prev_func
.addr
;
765 get_frame_func (struct frame_info
*this_frame
)
769 if (!get_frame_func_if_available (this_frame
, &pc
))
770 throw_error (NOT_AVAILABLE_ERROR
, _("PC not available"));
775 static enum register_status
776 do_frame_register_read (void *src
, int regnum
, gdb_byte
*buf
)
778 if (!frame_register_read (src
, regnum
, buf
))
779 return REG_UNAVAILABLE
;
785 frame_save_as_regcache (struct frame_info
*this_frame
)
787 struct address_space
*aspace
= get_frame_address_space (this_frame
);
788 struct regcache
*regcache
= regcache_xmalloc (get_frame_arch (this_frame
),
790 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (regcache
);
792 regcache_save (regcache
, do_frame_register_read
, this_frame
);
793 discard_cleanups (cleanups
);
798 frame_pop (struct frame_info
*this_frame
)
800 struct frame_info
*prev_frame
;
801 struct regcache
*scratch
;
802 struct cleanup
*cleanups
;
804 if (get_frame_type (this_frame
) == DUMMY_FRAME
)
806 /* Popping a dummy frame involves restoring more than just registers.
807 dummy_frame_pop does all the work. */
808 dummy_frame_pop (get_frame_id (this_frame
));
812 /* Ensure that we have a frame to pop to. */
813 prev_frame
= get_prev_frame_1 (this_frame
);
816 error (_("Cannot pop the initial frame."));
818 /* Make a copy of all the register values unwound from this frame.
819 Save them in a scratch buffer so that there isn't a race between
820 trying to extract the old values from the current regcache while
821 at the same time writing new values into that same cache. */
822 scratch
= frame_save_as_regcache (prev_frame
);
823 cleanups
= make_cleanup_regcache_xfree (scratch
);
825 /* FIXME: cagney/2003-03-16: It should be possible to tell the
826 target's register cache that it is about to be hit with a burst
827 register transfer and that the sequence of register writes should
828 be batched. The pair target_prepare_to_store() and
829 target_store_registers() kind of suggest this functionality.
830 Unfortunately, they don't implement it. Their lack of a formal
831 definition can lead to targets writing back bogus values
832 (arguably a bug in the target code mind). */
833 /* Now copy those saved registers into the current regcache.
834 Here, regcache_cpy() calls regcache_restore(). */
835 regcache_cpy (get_current_regcache (), scratch
);
836 do_cleanups (cleanups
);
838 /* We've made right mess of GDB's local state, just discard
840 reinit_frame_cache ();
844 frame_register_unwind (struct frame_info
*frame
, int regnum
,
845 int *optimizedp
, int *unavailablep
,
846 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
847 int *realnump
, gdb_byte
*bufferp
)
851 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
852 that the value proper does not need to be fetched. */
853 gdb_assert (optimizedp
!= NULL
);
854 gdb_assert (lvalp
!= NULL
);
855 gdb_assert (addrp
!= NULL
);
856 gdb_assert (realnump
!= NULL
);
857 /* gdb_assert (bufferp != NULL); */
859 value
= frame_unwind_register_value (frame
, regnum
);
861 gdb_assert (value
!= NULL
);
863 *optimizedp
= value_optimized_out (value
);
864 *unavailablep
= !value_entirely_available (value
);
865 *lvalp
= VALUE_LVAL (value
);
866 *addrp
= value_address (value
);
867 *realnump
= VALUE_REGNUM (value
);
871 if (!*optimizedp
&& !*unavailablep
)
872 memcpy (bufferp
, value_contents_all (value
),
873 TYPE_LENGTH (value_type (value
)));
875 memset (bufferp
, 0, TYPE_LENGTH (value_type (value
)));
878 /* Dispose of the new value. This prevents watchpoints from
879 trying to watch the saved frame pointer. */
880 release_value (value
);
885 frame_register (struct frame_info
*frame
, int regnum
,
886 int *optimizedp
, int *unavailablep
, enum lval_type
*lvalp
,
887 CORE_ADDR
*addrp
, int *realnump
, gdb_byte
*bufferp
)
889 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
890 that the value proper does not need to be fetched. */
891 gdb_assert (optimizedp
!= NULL
);
892 gdb_assert (lvalp
!= NULL
);
893 gdb_assert (addrp
!= NULL
);
894 gdb_assert (realnump
!= NULL
);
895 /* gdb_assert (bufferp != NULL); */
897 /* Obtain the register value by unwinding the register from the next
898 (more inner frame). */
899 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
900 frame_register_unwind (frame
->next
, regnum
, optimizedp
, unavailablep
,
901 lvalp
, addrp
, realnump
, bufferp
);
905 frame_unwind_register (struct frame_info
*frame
, int regnum
, gdb_byte
*buf
)
913 frame_register_unwind (frame
, regnum
, &optimized
, &unavailable
,
914 &lval
, &addr
, &realnum
, buf
);
917 error (_("Register %d was optimized out"), regnum
);
919 throw_error (NOT_AVAILABLE_ERROR
,
920 _("Register %d is not available"), regnum
);
924 get_frame_register (struct frame_info
*frame
,
925 int regnum
, gdb_byte
*buf
)
927 frame_unwind_register (frame
->next
, regnum
, buf
);
931 frame_unwind_register_value (struct frame_info
*frame
, int regnum
)
933 struct gdbarch
*gdbarch
;
936 gdb_assert (frame
!= NULL
);
937 gdbarch
= frame_unwind_arch (frame
);
941 fprintf_unfiltered (gdb_stdlog
,
942 "{ frame_unwind_register_value "
943 "(frame=%d,regnum=%d(%s),...) ",
944 frame
->level
, regnum
,
945 user_reg_map_regnum_to_name (gdbarch
, regnum
));
948 /* Find the unwinder. */
949 if (frame
->unwind
== NULL
)
950 frame_unwind_find_by_frame (frame
, &frame
->prologue_cache
);
952 /* Ask this frame to unwind its register. */
953 value
= frame
->unwind
->prev_register (frame
, &frame
->prologue_cache
, regnum
);
957 fprintf_unfiltered (gdb_stdlog
, "->");
958 if (value_optimized_out (value
))
959 fprintf_unfiltered (gdb_stdlog
, " optimized out");
962 if (VALUE_LVAL (value
) == lval_register
)
963 fprintf_unfiltered (gdb_stdlog
, " register=%d",
964 VALUE_REGNUM (value
));
965 else if (VALUE_LVAL (value
) == lval_memory
)
966 fprintf_unfiltered (gdb_stdlog
, " address=%s",
968 value_address (value
)));
970 fprintf_unfiltered (gdb_stdlog
, " computed");
972 if (value_lazy (value
))
973 fprintf_unfiltered (gdb_stdlog
, " lazy");
977 const gdb_byte
*buf
= value_contents (value
);
979 fprintf_unfiltered (gdb_stdlog
, " bytes=");
980 fprintf_unfiltered (gdb_stdlog
, "[");
981 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
982 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
983 fprintf_unfiltered (gdb_stdlog
, "]");
987 fprintf_unfiltered (gdb_stdlog
, " }\n");
994 get_frame_register_value (struct frame_info
*frame
, int regnum
)
996 return frame_unwind_register_value (frame
->next
, regnum
);
1000 frame_unwind_register_signed (struct frame_info
*frame
, int regnum
)
1002 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
1003 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
1004 int size
= register_size (gdbarch
, regnum
);
1005 gdb_byte buf
[MAX_REGISTER_SIZE
];
1007 frame_unwind_register (frame
, regnum
, buf
);
1008 return extract_signed_integer (buf
, size
, byte_order
);
1012 get_frame_register_signed (struct frame_info
*frame
, int regnum
)
1014 return frame_unwind_register_signed (frame
->next
, regnum
);
1018 frame_unwind_register_unsigned (struct frame_info
*frame
, int regnum
)
1020 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
1021 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
1022 int size
= register_size (gdbarch
, regnum
);
1023 gdb_byte buf
[MAX_REGISTER_SIZE
];
1025 frame_unwind_register (frame
, regnum
, buf
);
1026 return extract_unsigned_integer (buf
, size
, byte_order
);
1030 get_frame_register_unsigned (struct frame_info
*frame
, int regnum
)
1032 return frame_unwind_register_unsigned (frame
->next
, regnum
);
1036 put_frame_register (struct frame_info
*frame
, int regnum
,
1037 const gdb_byte
*buf
)
1039 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1043 enum lval_type lval
;
1046 frame_register (frame
, regnum
, &optim
, &unavail
,
1047 &lval
, &addr
, &realnum
, NULL
);
1049 error (_("Attempt to assign to a value that was optimized out."));
1054 /* FIXME: write_memory doesn't yet take constant buffers.
1056 gdb_byte tmp
[MAX_REGISTER_SIZE
];
1058 memcpy (tmp
, buf
, register_size (gdbarch
, regnum
));
1059 write_memory (addr
, tmp
, register_size (gdbarch
, regnum
));
1063 regcache_cooked_write (get_current_regcache (), realnum
, buf
);
1066 error (_("Attempt to assign to an unmodifiable value."));
1070 /* frame_register_read ()
1072 Find and return the value of REGNUM for the specified stack frame.
1073 The number of bytes copied is REGISTER_SIZE (REGNUM).
1075 Returns 0 if the register value could not be found. */
1078 frame_register_read (struct frame_info
*frame
, int regnum
,
1083 enum lval_type lval
;
1087 frame_register (frame
, regnum
, &optimized
, &unavailable
,
1088 &lval
, &addr
, &realnum
, myaddr
);
1090 return !optimized
&& !unavailable
;
1094 get_frame_register_bytes (struct frame_info
*frame
, int regnum
,
1095 CORE_ADDR offset
, int len
, gdb_byte
*myaddr
,
1096 int *optimizedp
, int *unavailablep
)
1098 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1103 /* Skip registers wholly inside of OFFSET. */
1104 while (offset
>= register_size (gdbarch
, regnum
))
1106 offset
-= register_size (gdbarch
, regnum
);
1110 /* Ensure that we will not read beyond the end of the register file.
1111 This can only ever happen if the debug information is bad. */
1113 numregs
= gdbarch_num_regs (gdbarch
) + gdbarch_num_pseudo_regs (gdbarch
);
1114 for (i
= regnum
; i
< numregs
; i
++)
1116 int thissize
= register_size (gdbarch
, i
);
1119 break; /* This register is not available on this architecture. */
1120 maxsize
+= thissize
;
1123 error (_("Bad debug information detected: "
1124 "Attempt to read %d bytes from registers."), len
);
1126 /* Copy the data. */
1129 int curr_len
= register_size (gdbarch
, regnum
) - offset
;
1134 if (curr_len
== register_size (gdbarch
, regnum
))
1136 enum lval_type lval
;
1140 frame_register (frame
, regnum
, optimizedp
, unavailablep
,
1141 &lval
, &addr
, &realnum
, myaddr
);
1142 if (*optimizedp
|| *unavailablep
)
1147 gdb_byte buf
[MAX_REGISTER_SIZE
];
1148 enum lval_type lval
;
1152 frame_register (frame
, regnum
, optimizedp
, unavailablep
,
1153 &lval
, &addr
, &realnum
, buf
);
1154 if (*optimizedp
|| *unavailablep
)
1156 memcpy (myaddr
, buf
+ offset
, curr_len
);
1171 put_frame_register_bytes (struct frame_info
*frame
, int regnum
,
1172 CORE_ADDR offset
, int len
, const gdb_byte
*myaddr
)
1174 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
1176 /* Skip registers wholly inside of OFFSET. */
1177 while (offset
>= register_size (gdbarch
, regnum
))
1179 offset
-= register_size (gdbarch
, regnum
);
1183 /* Copy the data. */
1186 int curr_len
= register_size (gdbarch
, regnum
) - offset
;
1191 if (curr_len
== register_size (gdbarch
, regnum
))
1193 put_frame_register (frame
, regnum
, myaddr
);
1197 gdb_byte buf
[MAX_REGISTER_SIZE
];
1199 frame_register_read (frame
, regnum
, buf
);
1200 memcpy (buf
+ offset
, myaddr
, curr_len
);
1201 put_frame_register (frame
, regnum
, buf
);
1211 /* Create a sentinel frame. */
1213 static struct frame_info
*
1214 create_sentinel_frame (struct program_space
*pspace
, struct regcache
*regcache
)
1216 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1219 frame
->pspace
= pspace
;
1220 frame
->aspace
= get_regcache_aspace (regcache
);
1221 /* Explicitly initialize the sentinel frame's cache. Provide it
1222 with the underlying regcache. In the future additional
1223 information, such as the frame's thread will be added. */
1224 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
1225 /* For the moment there is only one sentinel frame implementation. */
1226 frame
->unwind
= &sentinel_frame_unwind
;
1227 /* Link this frame back to itself. The frame is self referential
1228 (the unwound PC is the same as the pc), so make it so. */
1229 frame
->next
= frame
;
1230 /* Make the sentinel frame's ID valid, but invalid. That way all
1231 comparisons with it should fail. */
1232 frame
->this_id
.p
= 1;
1233 frame
->this_id
.value
= null_frame_id
;
1236 fprintf_unfiltered (gdb_stdlog
, "{ create_sentinel_frame (...) -> ");
1237 fprint_frame (gdb_stdlog
, frame
);
1238 fprintf_unfiltered (gdb_stdlog
, " }\n");
1243 /* Info about the innermost stack frame (contents of FP register). */
1245 static struct frame_info
*current_frame
;
1247 /* Cache for frame addresses already read by gdb. Valid only while
1248 inferior is stopped. Control variables for the frame cache should
1249 be local to this module. */
1251 static struct obstack frame_cache_obstack
;
1254 frame_obstack_zalloc (unsigned long size
)
1256 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
1258 memset (data
, 0, size
);
1262 /* Return the innermost (currently executing) stack frame. This is
1263 split into two functions. The function unwind_to_current_frame()
1264 is wrapped in catch exceptions so that, even when the unwind of the
1265 sentinel frame fails, the function still returns a stack frame. */
1268 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
1270 struct frame_info
*frame
= get_prev_frame (args
);
1272 /* A sentinel frame can fail to unwind, e.g., because its PC value
1273 lands in somewhere like start. */
1276 current_frame
= frame
;
1281 get_current_frame (void)
1283 /* First check, and report, the lack of registers. Having GDB
1284 report "No stack!" or "No memory" when the target doesn't even
1285 have registers is very confusing. Besides, "printcmd.exp"
1286 explicitly checks that ``print $pc'' with no registers prints "No
1288 if (!target_has_registers
)
1289 error (_("No registers."));
1290 if (!target_has_stack
)
1291 error (_("No stack."));
1292 if (!target_has_memory
)
1293 error (_("No memory."));
1294 /* Traceframes are effectively a substitute for the live inferior. */
1295 if (get_traceframe_number () < 0)
1297 if (ptid_equal (inferior_ptid
, null_ptid
))
1298 error (_("No selected thread."));
1299 if (is_exited (inferior_ptid
))
1300 error (_("Invalid selected thread."));
1301 if (is_executing (inferior_ptid
))
1302 error (_("Target is executing."));
1305 if (current_frame
== NULL
)
1307 struct frame_info
*sentinel_frame
=
1308 create_sentinel_frame (current_program_space
, get_current_regcache ());
1309 if (catch_exceptions (current_uiout
, unwind_to_current_frame
,
1310 sentinel_frame
, RETURN_MASK_ERROR
) != 0)
1312 /* Oops! Fake a current frame? Is this useful? It has a PC
1313 of zero, for instance. */
1314 current_frame
= sentinel_frame
;
1317 return current_frame
;
1320 /* The "selected" stack frame is used by default for local and arg
1321 access. May be zero, for no selected frame. */
1323 static struct frame_info
*selected_frame
;
1326 has_stack_frames (void)
1328 if (!target_has_registers
|| !target_has_stack
|| !target_has_memory
)
1331 /* Traceframes are effectively a substitute for the live inferior. */
1332 if (get_traceframe_number () < 0)
1334 /* No current inferior, no frame. */
1335 if (ptid_equal (inferior_ptid
, null_ptid
))
1338 /* Don't try to read from a dead thread. */
1339 if (is_exited (inferior_ptid
))
1342 /* ... or from a spinning thread. */
1343 if (is_executing (inferior_ptid
))
1350 /* Return the selected frame. Always non-NULL (unless there isn't an
1351 inferior sufficient for creating a frame) in which case an error is
1355 get_selected_frame (const char *message
)
1357 if (selected_frame
== NULL
)
1359 if (message
!= NULL
&& !has_stack_frames ())
1360 error (("%s"), message
);
1361 /* Hey! Don't trust this. It should really be re-finding the
1362 last selected frame of the currently selected thread. This,
1363 though, is better than nothing. */
1364 select_frame (get_current_frame ());
1366 /* There is always a frame. */
1367 gdb_assert (selected_frame
!= NULL
);
1368 return selected_frame
;
1371 /* If there is a selected frame, return it. Otherwise, return NULL. */
1374 get_selected_frame_if_set (void)
1376 return selected_frame
;
1379 /* This is a variant of get_selected_frame() which can be called when
1380 the inferior does not have a frame; in that case it will return
1381 NULL instead of calling error(). */
1384 deprecated_safe_get_selected_frame (void)
1386 if (!has_stack_frames ())
1388 return get_selected_frame (NULL
);
1391 /* Select frame FI (or NULL - to invalidate the current frame). */
1394 select_frame (struct frame_info
*fi
)
1396 selected_frame
= fi
;
1397 /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
1398 frame is being invalidated. */
1399 if (deprecated_selected_frame_level_changed_hook
)
1400 deprecated_selected_frame_level_changed_hook (frame_relative_level (fi
));
1402 /* FIXME: kseitz/2002-08-28: It would be nice to call
1403 selected_frame_level_changed_event() right here, but due to limitations
1404 in the current interfaces, we would end up flooding UIs with events
1405 because select_frame() is used extensively internally.
1407 Once we have frame-parameterized frame (and frame-related) commands,
1408 the event notification can be moved here, since this function will only
1409 be called when the user's selected frame is being changed. */
1411 /* Ensure that symbols for this frame are read in. Also, determine the
1412 source language of this frame, and switch to it if desired. */
1417 /* We retrieve the frame's symtab by using the frame PC.
1418 However we cannot use the frame PC as-is, because it usually
1419 points to the instruction following the "call", which is
1420 sometimes the first instruction of another function. So we
1421 rely on get_frame_address_in_block() which provides us with a
1422 PC which is guaranteed to be inside the frame's code
1424 if (get_frame_address_in_block_if_available (fi
, &pc
))
1426 struct symtab
*s
= find_pc_symtab (pc
);
1429 && s
->language
!= current_language
->la_language
1430 && s
->language
!= language_unknown
1431 && language_mode
== language_mode_auto
)
1432 set_language (s
->language
);
1437 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
1438 Always returns a non-NULL value. */
1441 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
1443 struct frame_info
*fi
;
1447 fprintf_unfiltered (gdb_stdlog
,
1448 "{ create_new_frame (addr=%s, pc=%s) ",
1449 hex_string (addr
), hex_string (pc
));
1452 fi
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1454 fi
->next
= create_sentinel_frame (current_program_space
,
1455 get_current_regcache ());
1457 /* Set/update this frame's cached PC value, found in the next frame.
1458 Do this before looking for this frame's unwinder. A sniffer is
1459 very likely to read this, and the corresponding unwinder is
1460 entitled to rely that the PC doesn't magically change. */
1461 fi
->next
->prev_pc
.value
= pc
;
1462 fi
->next
->prev_pc
.p
= 1;
1464 /* We currently assume that frame chain's can't cross spaces. */
1465 fi
->pspace
= fi
->next
->pspace
;
1466 fi
->aspace
= fi
->next
->aspace
;
1468 /* Select/initialize both the unwind function and the frame's type
1470 frame_unwind_find_by_frame (fi
, &fi
->prologue_cache
);
1473 fi
->this_id
.value
= frame_id_build (addr
, pc
);
1477 fprintf_unfiltered (gdb_stdlog
, "-> ");
1478 fprint_frame (gdb_stdlog
, fi
);
1479 fprintf_unfiltered (gdb_stdlog
, " }\n");
1485 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
1486 innermost frame). Be careful to not fall off the bottom of the
1487 frame chain and onto the sentinel frame. */
1490 get_next_frame (struct frame_info
*this_frame
)
1492 if (this_frame
->level
> 0)
1493 return this_frame
->next
;
1498 /* Observer for the target_changed event. */
1501 frame_observer_target_changed (struct target_ops
*target
)
1503 reinit_frame_cache ();
1506 /* Flush the entire frame cache. */
1509 reinit_frame_cache (void)
1511 struct frame_info
*fi
;
1513 /* Tear down all frame caches. */
1514 for (fi
= current_frame
; fi
!= NULL
; fi
= fi
->prev
)
1516 if (fi
->prologue_cache
&& fi
->unwind
->dealloc_cache
)
1517 fi
->unwind
->dealloc_cache (fi
, fi
->prologue_cache
);
1518 if (fi
->base_cache
&& fi
->base
->unwind
->dealloc_cache
)
1519 fi
->base
->unwind
->dealloc_cache (fi
, fi
->base_cache
);
1522 /* Since we can't really be sure what the first object allocated was. */
1523 obstack_free (&frame_cache_obstack
, 0);
1524 obstack_init (&frame_cache_obstack
);
1526 if (current_frame
!= NULL
)
1527 annotate_frames_invalid ();
1529 current_frame
= NULL
; /* Invalidate cache */
1530 select_frame (NULL
);
1531 frame_stash_invalidate ();
1533 fprintf_unfiltered (gdb_stdlog
, "{ reinit_frame_cache () }\n");
1536 /* Find where a register is saved (in memory or another register).
1537 The result of frame_register_unwind is just where it is saved
1538 relative to this particular frame. */
1541 frame_register_unwind_location (struct frame_info
*this_frame
, int regnum
,
1542 int *optimizedp
, enum lval_type
*lvalp
,
1543 CORE_ADDR
*addrp
, int *realnump
)
1545 gdb_assert (this_frame
== NULL
|| this_frame
->level
>= 0);
1547 while (this_frame
!= NULL
)
1551 frame_register_unwind (this_frame
, regnum
, optimizedp
, &unavailable
,
1552 lvalp
, addrp
, realnump
, NULL
);
1557 if (*lvalp
!= lval_register
)
1561 this_frame
= get_next_frame (this_frame
);
1565 /* Return a "struct frame_info" corresponding to the frame that called
1566 THIS_FRAME. Returns NULL if there is no such frame.
1568 Unlike get_prev_frame, this function always tries to unwind the
1571 static struct frame_info
*
1572 get_prev_frame_1 (struct frame_info
*this_frame
)
1574 struct frame_id this_id
;
1575 struct gdbarch
*gdbarch
;
1577 gdb_assert (this_frame
!= NULL
);
1578 gdbarch
= get_frame_arch (this_frame
);
1582 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame_1 (this_frame=");
1583 if (this_frame
!= NULL
)
1584 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1586 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1587 fprintf_unfiltered (gdb_stdlog
, ") ");
1590 /* Only try to do the unwind once. */
1591 if (this_frame
->prev_p
)
1595 fprintf_unfiltered (gdb_stdlog
, "-> ");
1596 fprint_frame (gdb_stdlog
, this_frame
->prev
);
1597 fprintf_unfiltered (gdb_stdlog
, " // cached \n");
1599 return this_frame
->prev
;
1602 /* If the frame unwinder hasn't been selected yet, we must do so
1603 before setting prev_p; otherwise the check for misbehaved
1604 sniffers will think that this frame's sniffer tried to unwind
1605 further (see frame_cleanup_after_sniffer). */
1606 if (this_frame
->unwind
== NULL
)
1607 frame_unwind_find_by_frame (this_frame
, &this_frame
->prologue_cache
);
1609 this_frame
->prev_p
= 1;
1610 this_frame
->stop_reason
= UNWIND_NO_REASON
;
1612 /* If we are unwinding from an inline frame, all of the below tests
1613 were already performed when we unwound from the next non-inline
1614 frame. We must skip them, since we can not get THIS_FRAME's ID
1615 until we have unwound all the way down to the previous non-inline
1617 if (get_frame_type (this_frame
) == INLINE_FRAME
)
1618 return get_prev_frame_raw (this_frame
);
1620 /* Check that this frame is unwindable. If it isn't, don't try to
1621 unwind to the prev frame. */
1622 this_frame
->stop_reason
1623 = this_frame
->unwind
->stop_reason (this_frame
,
1624 &this_frame
->prologue_cache
);
1626 if (this_frame
->stop_reason
!= UNWIND_NO_REASON
)
1629 /* Check that this frame's ID was valid. If it wasn't, don't try to
1630 unwind to the prev frame. Be careful to not apply this test to
1631 the sentinel frame. */
1632 this_id
= get_frame_id (this_frame
);
1633 if (this_frame
->level
>= 0 && frame_id_eq (this_id
, outer_frame_id
))
1637 fprintf_unfiltered (gdb_stdlog
, "-> ");
1638 fprint_frame (gdb_stdlog
, NULL
);
1639 fprintf_unfiltered (gdb_stdlog
, " // this ID is NULL }\n");
1641 this_frame
->stop_reason
= UNWIND_NULL_ID
;
1645 /* Check that this frame's ID isn't inner to (younger, below, next)
1646 the next frame. This happens when a frame unwind goes backwards.
1647 This check is valid only if this frame and the next frame are NORMAL.
1648 See the comment at frame_id_inner for details. */
1649 if (get_frame_type (this_frame
) == NORMAL_FRAME
1650 && this_frame
->next
->unwind
->type
== NORMAL_FRAME
1651 && frame_id_inner (get_frame_arch (this_frame
->next
), this_id
,
1652 get_frame_id (this_frame
->next
)))
1654 CORE_ADDR this_pc_in_block
;
1655 struct minimal_symbol
*morestack_msym
;
1656 const char *morestack_name
= NULL
;
1658 /* gcc -fsplit-stack __morestack can continue the stack anywhere. */
1659 this_pc_in_block
= get_frame_address_in_block (this_frame
);
1660 morestack_msym
= lookup_minimal_symbol_by_pc (this_pc_in_block
);
1662 morestack_name
= SYMBOL_LINKAGE_NAME (morestack_msym
);
1663 if (!morestack_name
|| strcmp (morestack_name
, "__morestack") != 0)
1667 fprintf_unfiltered (gdb_stdlog
, "-> ");
1668 fprint_frame (gdb_stdlog
, NULL
);
1669 fprintf_unfiltered (gdb_stdlog
,
1670 " // this frame ID is inner }\n");
1672 this_frame
->stop_reason
= UNWIND_INNER_ID
;
1677 /* Check that this and the next frame are not identical. If they
1678 are, there is most likely a stack cycle. As with the inner-than
1679 test above, avoid comparing the inner-most and sentinel frames. */
1680 if (this_frame
->level
> 0
1681 && frame_id_eq (this_id
, get_frame_id (this_frame
->next
)))
1685 fprintf_unfiltered (gdb_stdlog
, "-> ");
1686 fprint_frame (gdb_stdlog
, NULL
);
1687 fprintf_unfiltered (gdb_stdlog
, " // this frame has same ID }\n");
1689 this_frame
->stop_reason
= UNWIND_SAME_ID
;
1693 /* Check that this and the next frame do not unwind the PC register
1694 to the same memory location. If they do, then even though they
1695 have different frame IDs, the new frame will be bogus; two
1696 functions can't share a register save slot for the PC. This can
1697 happen when the prologue analyzer finds a stack adjustment, but
1700 This check does assume that the "PC register" is roughly a
1701 traditional PC, even if the gdbarch_unwind_pc method adjusts
1702 it (we do not rely on the value, only on the unwound PC being
1703 dependent on this value). A potential improvement would be
1704 to have the frame prev_pc method and the gdbarch unwind_pc
1705 method set the same lval and location information as
1706 frame_register_unwind. */
1707 if (this_frame
->level
> 0
1708 && gdbarch_pc_regnum (gdbarch
) >= 0
1709 && get_frame_type (this_frame
) == NORMAL_FRAME
1710 && (get_frame_type (this_frame
->next
) == NORMAL_FRAME
1711 || get_frame_type (this_frame
->next
) == INLINE_FRAME
))
1713 int optimized
, realnum
, nrealnum
;
1714 enum lval_type lval
, nlval
;
1715 CORE_ADDR addr
, naddr
;
1717 frame_register_unwind_location (this_frame
,
1718 gdbarch_pc_regnum (gdbarch
),
1719 &optimized
, &lval
, &addr
, &realnum
);
1720 frame_register_unwind_location (get_next_frame (this_frame
),
1721 gdbarch_pc_regnum (gdbarch
),
1722 &optimized
, &nlval
, &naddr
, &nrealnum
);
1724 if ((lval
== lval_memory
&& lval
== nlval
&& addr
== naddr
)
1725 || (lval
== lval_register
&& lval
== nlval
&& realnum
== nrealnum
))
1729 fprintf_unfiltered (gdb_stdlog
, "-> ");
1730 fprint_frame (gdb_stdlog
, NULL
);
1731 fprintf_unfiltered (gdb_stdlog
, " // no saved PC }\n");
1734 this_frame
->stop_reason
= UNWIND_NO_SAVED_PC
;
1735 this_frame
->prev
= NULL
;
1740 return get_prev_frame_raw (this_frame
);
1743 /* Construct a new "struct frame_info" and link it previous to
1746 static struct frame_info
*
1747 get_prev_frame_raw (struct frame_info
*this_frame
)
1749 struct frame_info
*prev_frame
;
1751 /* Allocate the new frame but do not wire it in to the frame chain.
1752 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1753 frame->next to pull some fancy tricks (of course such code is, by
1754 definition, recursive). Try to prevent it.
1756 There is no reason to worry about memory leaks, should the
1757 remainder of the function fail. The allocated memory will be
1758 quickly reclaimed when the frame cache is flushed, and the `we've
1759 been here before' check above will stop repeated memory
1760 allocation calls. */
1761 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1762 prev_frame
->level
= this_frame
->level
+ 1;
1764 /* For now, assume we don't have frame chains crossing address
1766 prev_frame
->pspace
= this_frame
->pspace
;
1767 prev_frame
->aspace
= this_frame
->aspace
;
1769 /* Don't yet compute ->unwind (and hence ->type). It is computed
1770 on-demand in get_frame_type, frame_register_unwind, and
1773 /* Don't yet compute the frame's ID. It is computed on-demand by
1776 /* The unwound frame ID is validate at the start of this function,
1777 as part of the logic to decide if that frame should be further
1778 unwound, and not here while the prev frame is being created.
1779 Doing this makes it possible for the user to examine a frame that
1780 has an invalid frame ID.
1782 Some very old VAX code noted: [...] For the sake of argument,
1783 suppose that the stack is somewhat trashed (which is one reason
1784 that "info frame" exists). So, return 0 (indicating we don't
1785 know the address of the arglist) if we don't know what frame this
1789 this_frame
->prev
= prev_frame
;
1790 prev_frame
->next
= this_frame
;
1794 fprintf_unfiltered (gdb_stdlog
, "-> ");
1795 fprint_frame (gdb_stdlog
, prev_frame
);
1796 fprintf_unfiltered (gdb_stdlog
, " }\n");
1802 /* Debug routine to print a NULL frame being returned. */
1805 frame_debug_got_null_frame (struct frame_info
*this_frame
,
1810 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame (this_frame=");
1811 if (this_frame
!= NULL
)
1812 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1814 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1815 fprintf_unfiltered (gdb_stdlog
, ") -> // %s}\n", reason
);
1819 /* Is this (non-sentinel) frame in the "main"() function? */
1822 inside_main_func (struct frame_info
*this_frame
)
1824 struct minimal_symbol
*msymbol
;
1827 if (symfile_objfile
== 0)
1829 msymbol
= lookup_minimal_symbol (main_name (), NULL
, symfile_objfile
);
1830 if (msymbol
== NULL
)
1832 /* Make certain that the code, and not descriptor, address is
1834 maddr
= gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame
),
1835 SYMBOL_VALUE_ADDRESS (msymbol
),
1837 return maddr
== get_frame_func (this_frame
);
1840 /* Test whether THIS_FRAME is inside the process entry point function. */
1843 inside_entry_func (struct frame_info
*this_frame
)
1845 CORE_ADDR entry_point
;
1847 if (!entry_point_address_query (&entry_point
))
1850 return get_frame_func (this_frame
) == entry_point
;
1853 /* Return a structure containing various interesting information about
1854 the frame that called THIS_FRAME. Returns NULL if there is entier
1855 no such frame or the frame fails any of a set of target-independent
1856 condition that should terminate the frame chain (e.g., as unwinding
1859 This function should not contain target-dependent tests, such as
1860 checking whether the program-counter is zero. */
1863 get_prev_frame (struct frame_info
*this_frame
)
1868 /* There is always a frame. If this assertion fails, suspect that
1869 something should be calling get_selected_frame() or
1870 get_current_frame(). */
1871 gdb_assert (this_frame
!= NULL
);
1872 frame_pc_p
= get_frame_pc_if_available (this_frame
, &frame_pc
);
1874 /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much
1875 sense to stop unwinding at a dummy frame. One place where a dummy
1876 frame may have an address "inside_main_func" is on HPUX. On HPUX, the
1877 pcsqh register (space register for the instruction at the head of the
1878 instruction queue) cannot be written directly; the only way to set it
1879 is to branch to code that is in the target space. In order to implement
1880 frame dummies on HPUX, the called function is made to jump back to where
1881 the inferior was when the user function was called. If gdb was inside
1882 the main function when we created the dummy frame, the dummy frame will
1883 point inside the main function. */
1884 if (this_frame
->level
>= 0
1885 && get_frame_type (this_frame
) == NORMAL_FRAME
1886 && !backtrace_past_main
1888 && inside_main_func (this_frame
))
1889 /* Don't unwind past main(). Note, this is done _before_ the
1890 frame has been marked as previously unwound. That way if the
1891 user later decides to enable unwinds past main(), that will
1892 automatically happen. */
1894 frame_debug_got_null_frame (this_frame
, "inside main func");
1898 /* If the user's backtrace limit has been exceeded, stop. We must
1899 add two to the current level; one of those accounts for backtrace_limit
1900 being 1-based and the level being 0-based, and the other accounts for
1901 the level of the new frame instead of the level of the current
1903 if (this_frame
->level
+ 2 > backtrace_limit
)
1905 frame_debug_got_null_frame (this_frame
, "backtrace limit exceeded");
1909 /* If we're already inside the entry function for the main objfile,
1910 then it isn't valid. Don't apply this test to a dummy frame -
1911 dummy frame PCs typically land in the entry func. Don't apply
1912 this test to the sentinel frame. Sentinel frames should always
1913 be allowed to unwind. */
1914 /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
1915 wasn't checking for "main" in the minimal symbols. With that
1916 fixed asm-source tests now stop in "main" instead of halting the
1917 backtrace in weird and wonderful ways somewhere inside the entry
1918 file. Suspect that tests for inside the entry file/func were
1919 added to work around that (now fixed) case. */
1920 /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
1921 suggested having the inside_entry_func test use the
1922 inside_main_func() msymbol trick (along with entry_point_address()
1923 I guess) to determine the address range of the start function.
1924 That should provide a far better stopper than the current
1926 /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler
1927 applied tail-call optimizations to main so that a function called
1928 from main returns directly to the caller of main. Since we don't
1929 stop at main, we should at least stop at the entry point of the
1931 if (this_frame
->level
>= 0
1932 && get_frame_type (this_frame
) == NORMAL_FRAME
1933 && !backtrace_past_entry
1935 && inside_entry_func (this_frame
))
1937 frame_debug_got_null_frame (this_frame
, "inside entry func");
1941 /* Assume that the only way to get a zero PC is through something
1942 like a SIGSEGV or a dummy frame, and hence that NORMAL frames
1943 will never unwind a zero PC. */
1944 if (this_frame
->level
> 0
1945 && (get_frame_type (this_frame
) == NORMAL_FRAME
1946 || get_frame_type (this_frame
) == INLINE_FRAME
)
1947 && get_frame_type (get_next_frame (this_frame
)) == NORMAL_FRAME
1948 && frame_pc_p
&& frame_pc
== 0)
1950 frame_debug_got_null_frame (this_frame
, "zero PC");
1954 return get_prev_frame_1 (this_frame
);
1958 get_frame_pc (struct frame_info
*frame
)
1960 gdb_assert (frame
->next
!= NULL
);
1961 return frame_unwind_pc (frame
->next
);
1965 get_frame_pc_if_available (struct frame_info
*frame
, CORE_ADDR
*pc
)
1967 volatile struct gdb_exception ex
;
1969 gdb_assert (frame
->next
!= NULL
);
1971 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
1973 *pc
= frame_unwind_pc (frame
->next
);
1977 if (ex
.error
== NOT_AVAILABLE_ERROR
)
1980 throw_exception (ex
);
1986 /* Return an address that falls within THIS_FRAME's code block. */
1989 get_frame_address_in_block (struct frame_info
*this_frame
)
1991 /* A draft address. */
1992 CORE_ADDR pc
= get_frame_pc (this_frame
);
1994 struct frame_info
*next_frame
= this_frame
->next
;
1996 /* Calling get_frame_pc returns the resume address for THIS_FRAME.
1997 Normally the resume address is inside the body of the function
1998 associated with THIS_FRAME, but there is a special case: when
1999 calling a function which the compiler knows will never return
2000 (for instance abort), the call may be the very last instruction
2001 in the calling function. The resume address will point after the
2002 call and may be at the beginning of a different function
2005 If THIS_FRAME is a signal frame or dummy frame, then we should
2006 not adjust the unwound PC. For a dummy frame, GDB pushed the
2007 resume address manually onto the stack. For a signal frame, the
2008 OS may have pushed the resume address manually and invoked the
2009 handler (e.g. GNU/Linux), or invoked the trampoline which called
2010 the signal handler - but in either case the signal handler is
2011 expected to return to the trampoline. So in both of these
2012 cases we know that the resume address is executable and
2013 related. So we only need to adjust the PC if THIS_FRAME
2014 is a normal function.
2016 If the program has been interrupted while THIS_FRAME is current,
2017 then clearly the resume address is inside the associated
2018 function. There are three kinds of interruption: debugger stop
2019 (next frame will be SENTINEL_FRAME), operating system
2020 signal or exception (next frame will be SIGTRAMP_FRAME),
2021 or debugger-induced function call (next frame will be
2022 DUMMY_FRAME). So we only need to adjust the PC if
2023 NEXT_FRAME is a normal function.
2025 We check the type of NEXT_FRAME first, since it is already
2026 known; frame type is determined by the unwinder, and since
2027 we have THIS_FRAME we've already selected an unwinder for
2030 If the next frame is inlined, we need to keep going until we find
2031 the real function - for instance, if a signal handler is invoked
2032 while in an inlined function, then the code address of the
2033 "calling" normal function should not be adjusted either. */
2035 while (get_frame_type (next_frame
) == INLINE_FRAME
)
2036 next_frame
= next_frame
->next
;
2038 if ((get_frame_type (next_frame
) == NORMAL_FRAME
2039 || get_frame_type (next_frame
) == TAILCALL_FRAME
)
2040 && (get_frame_type (this_frame
) == NORMAL_FRAME
2041 || get_frame_type (this_frame
) == TAILCALL_FRAME
2042 || get_frame_type (this_frame
) == INLINE_FRAME
))
2049 get_frame_address_in_block_if_available (struct frame_info
*this_frame
,
2052 volatile struct gdb_exception ex
;
2054 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2056 *pc
= get_frame_address_in_block (this_frame
);
2058 if (ex
.reason
< 0 && ex
.error
== NOT_AVAILABLE_ERROR
)
2060 else if (ex
.reason
< 0)
2061 throw_exception (ex
);
2067 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
2069 struct frame_info
*next_frame
;
2073 /* If the next frame represents an inlined function call, this frame's
2074 sal is the "call site" of that inlined function, which can not
2075 be inferred from get_frame_pc. */
2076 next_frame
= get_next_frame (frame
);
2077 if (frame_inlined_callees (frame
) > 0)
2082 sym
= get_frame_function (next_frame
);
2084 sym
= inline_skipped_symbol (inferior_ptid
);
2086 /* If frame is inline, it certainly has symbols. */
2089 if (SYMBOL_LINE (sym
) != 0)
2091 sal
->symtab
= SYMBOL_SYMTAB (sym
);
2092 sal
->line
= SYMBOL_LINE (sym
);
2095 /* If the symbol does not have a location, we don't know where
2096 the call site is. Do not pretend to. This is jarring, but
2097 we can't do much better. */
2098 sal
->pc
= get_frame_pc (frame
);
2103 /* If FRAME is not the innermost frame, that normally means that
2104 FRAME->pc points at the return instruction (which is *after* the
2105 call instruction), and we want to get the line containing the
2106 call (because the call is where the user thinks the program is).
2107 However, if the next frame is either a SIGTRAMP_FRAME or a
2108 DUMMY_FRAME, then the next frame will contain a saved interrupt
2109 PC and such a PC indicates the current (rather than next)
2110 instruction/line, consequently, for such cases, want to get the
2111 line containing fi->pc. */
2112 if (!get_frame_pc_if_available (frame
, &pc
))
2118 notcurrent
= (pc
!= get_frame_address_in_block (frame
));
2119 (*sal
) = find_pc_line (pc
, notcurrent
);
2122 /* Per "frame.h", return the ``address'' of the frame. Code should
2123 really be using get_frame_id(). */
2125 get_frame_base (struct frame_info
*fi
)
2127 return get_frame_id (fi
).stack_addr
;
2130 /* High-level offsets into the frame. Used by the debug info. */
2133 get_frame_base_address (struct frame_info
*fi
)
2135 if (get_frame_type (fi
) != NORMAL_FRAME
)
2137 if (fi
->base
== NULL
)
2138 fi
->base
= frame_base_find_by_frame (fi
);
2139 /* Sneaky: If the low-level unwind and high-level base code share a
2140 common unwinder, let them share the prologue cache. */
2141 if (fi
->base
->unwind
== fi
->unwind
)
2142 return fi
->base
->this_base (fi
, &fi
->prologue_cache
);
2143 return fi
->base
->this_base (fi
, &fi
->base_cache
);
2147 get_frame_locals_address (struct frame_info
*fi
)
2149 if (get_frame_type (fi
) != NORMAL_FRAME
)
2151 /* If there isn't a frame address method, find it. */
2152 if (fi
->base
== NULL
)
2153 fi
->base
= frame_base_find_by_frame (fi
);
2154 /* Sneaky: If the low-level unwind and high-level base code share a
2155 common unwinder, let them share the prologue cache. */
2156 if (fi
->base
->unwind
== fi
->unwind
)
2157 return fi
->base
->this_locals (fi
, &fi
->prologue_cache
);
2158 return fi
->base
->this_locals (fi
, &fi
->base_cache
);
2162 get_frame_args_address (struct frame_info
*fi
)
2164 if (get_frame_type (fi
) != NORMAL_FRAME
)
2166 /* If there isn't a frame address method, find it. */
2167 if (fi
->base
== NULL
)
2168 fi
->base
= frame_base_find_by_frame (fi
);
2169 /* Sneaky: If the low-level unwind and high-level base code share a
2170 common unwinder, let them share the prologue cache. */
2171 if (fi
->base
->unwind
== fi
->unwind
)
2172 return fi
->base
->this_args (fi
, &fi
->prologue_cache
);
2173 return fi
->base
->this_args (fi
, &fi
->base_cache
);
2176 /* Return true if the frame unwinder for frame FI is UNWINDER; false
2180 frame_unwinder_is (struct frame_info
*fi
, const struct frame_unwind
*unwinder
)
2182 if (fi
->unwind
== NULL
)
2183 frame_unwind_find_by_frame (fi
, &fi
->prologue_cache
);
2184 return fi
->unwind
== unwinder
;
2187 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
2188 or -1 for a NULL frame. */
2191 frame_relative_level (struct frame_info
*fi
)
2200 get_frame_type (struct frame_info
*frame
)
2202 if (frame
->unwind
== NULL
)
2203 /* Initialize the frame's unwinder because that's what
2204 provides the frame's type. */
2205 frame_unwind_find_by_frame (frame
, &frame
->prologue_cache
);
2206 return frame
->unwind
->type
;
2209 struct program_space
*
2210 get_frame_program_space (struct frame_info
*frame
)
2212 return frame
->pspace
;
2215 struct program_space
*
2216 frame_unwind_program_space (struct frame_info
*this_frame
)
2218 gdb_assert (this_frame
);
2220 /* This is really a placeholder to keep the API consistent --- we
2221 assume for now that we don't have frame chains crossing
2223 return this_frame
->pspace
;
2226 struct address_space
*
2227 get_frame_address_space (struct frame_info
*frame
)
2229 return frame
->aspace
;
2232 /* Memory access methods. */
2235 get_frame_memory (struct frame_info
*this_frame
, CORE_ADDR addr
,
2236 gdb_byte
*buf
, int len
)
2238 read_memory (addr
, buf
, len
);
2242 get_frame_memory_signed (struct frame_info
*this_frame
, CORE_ADDR addr
,
2245 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
2246 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
2248 return read_memory_integer (addr
, len
, byte_order
);
2252 get_frame_memory_unsigned (struct frame_info
*this_frame
, CORE_ADDR addr
,
2255 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
2256 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
2258 return read_memory_unsigned_integer (addr
, len
, byte_order
);
2262 safe_frame_unwind_memory (struct frame_info
*this_frame
,
2263 CORE_ADDR addr
, gdb_byte
*buf
, int len
)
2265 /* NOTE: target_read_memory returns zero on success! */
2266 return !target_read_memory (addr
, buf
, len
);
2269 /* Architecture methods. */
2272 get_frame_arch (struct frame_info
*this_frame
)
2274 return frame_unwind_arch (this_frame
->next
);
2278 frame_unwind_arch (struct frame_info
*next_frame
)
2280 if (!next_frame
->prev_arch
.p
)
2282 struct gdbarch
*arch
;
2284 if (next_frame
->unwind
== NULL
)
2285 frame_unwind_find_by_frame (next_frame
, &next_frame
->prologue_cache
);
2287 if (next_frame
->unwind
->prev_arch
!= NULL
)
2288 arch
= next_frame
->unwind
->prev_arch (next_frame
,
2289 &next_frame
->prologue_cache
);
2291 arch
= get_frame_arch (next_frame
);
2293 next_frame
->prev_arch
.arch
= arch
;
2294 next_frame
->prev_arch
.p
= 1;
2296 fprintf_unfiltered (gdb_stdlog
,
2297 "{ frame_unwind_arch (next_frame=%d) -> %s }\n",
2299 gdbarch_bfd_arch_info (arch
)->printable_name
);
2302 return next_frame
->prev_arch
.arch
;
2306 frame_unwind_caller_arch (struct frame_info
*next_frame
)
2308 return frame_unwind_arch (skip_inlined_frames (next_frame
));
2311 /* Stack pointer methods. */
2314 get_frame_sp (struct frame_info
*this_frame
)
2316 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
2318 /* Normality - an architecture that provides a way of obtaining any
2319 frame inner-most address. */
2320 if (gdbarch_unwind_sp_p (gdbarch
))
2321 /* NOTE drow/2008-06-28: gdbarch_unwind_sp could be converted to
2322 operate on THIS_FRAME now. */
2323 return gdbarch_unwind_sp (gdbarch
, this_frame
->next
);
2324 /* Now things are really are grim. Hope that the value returned by
2325 the gdbarch_sp_regnum register is meaningful. */
2326 if (gdbarch_sp_regnum (gdbarch
) >= 0)
2327 return get_frame_register_unsigned (this_frame
,
2328 gdbarch_sp_regnum (gdbarch
));
2329 internal_error (__FILE__
, __LINE__
, _("Missing unwind SP method"));
2332 /* Return the reason why we can't unwind past FRAME. */
2334 enum unwind_stop_reason
2335 get_frame_unwind_stop_reason (struct frame_info
*frame
)
2337 /* If we haven't tried to unwind past this point yet, then assume
2338 that unwinding would succeed. */
2339 if (frame
->prev_p
== 0)
2340 return UNWIND_NO_REASON
;
2342 /* Otherwise, we set a reason when we succeeded (or failed) to
2344 return frame
->stop_reason
;
2347 /* Return a string explaining REASON. */
2350 frame_stop_reason_string (enum unwind_stop_reason reason
)
2354 case UNWIND_NULL_ID
:
2355 return _("unwinder did not report frame ID");
2357 case UNWIND_UNAVAILABLE
:
2358 return _("Not enough registers or memory available to unwind further");
2360 case UNWIND_INNER_ID
:
2361 return _("previous frame inner to this frame (corrupt stack?)");
2363 case UNWIND_SAME_ID
:
2364 return _("previous frame identical to this frame (corrupt stack?)");
2366 case UNWIND_NO_SAVED_PC
:
2367 return _("frame did not save the PC");
2369 case UNWIND_NO_REASON
:
2370 case UNWIND_FIRST_ERROR
:
2372 internal_error (__FILE__
, __LINE__
,
2373 "Invalid frame stop reason");
2377 /* Clean up after a failed (wrong unwinder) attempt to unwind past
2381 frame_cleanup_after_sniffer (void *arg
)
2383 struct frame_info
*frame
= arg
;
2385 /* The sniffer should not allocate a prologue cache if it did not
2386 match this frame. */
2387 gdb_assert (frame
->prologue_cache
== NULL
);
2389 /* No sniffer should extend the frame chain; sniff based on what is
2391 gdb_assert (!frame
->prev_p
);
2393 /* The sniffer should not check the frame's ID; that's circular. */
2394 gdb_assert (!frame
->this_id
.p
);
2396 /* Clear cached fields dependent on the unwinder.
2398 The previous PC is independent of the unwinder, but the previous
2399 function is not (see get_frame_address_in_block). */
2400 frame
->prev_func
.p
= 0;
2401 frame
->prev_func
.addr
= 0;
2403 /* Discard the unwinder last, so that we can easily find it if an assertion
2404 in this function triggers. */
2405 frame
->unwind
= NULL
;
2408 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
2409 Return a cleanup which should be called if unwinding fails, and
2410 discarded if it succeeds. */
2413 frame_prepare_for_sniffer (struct frame_info
*frame
,
2414 const struct frame_unwind
*unwind
)
2416 gdb_assert (frame
->unwind
== NULL
);
2417 frame
->unwind
= unwind
;
2418 return make_cleanup (frame_cleanup_after_sniffer
, frame
);
2421 extern initialize_file_ftype _initialize_frame
; /* -Wmissing-prototypes */
2423 static struct cmd_list_element
*set_backtrace_cmdlist
;
2424 static struct cmd_list_element
*show_backtrace_cmdlist
;
2427 set_backtrace_cmd (char *args
, int from_tty
)
2429 help_list (set_backtrace_cmdlist
, "set backtrace ", -1, gdb_stdout
);
2433 show_backtrace_cmd (char *args
, int from_tty
)
2435 cmd_show_list (show_backtrace_cmdlist
, from_tty
, "");
2439 _initialize_frame (void)
2441 obstack_init (&frame_cache_obstack
);
2443 observer_attach_target_changed (frame_observer_target_changed
);
2445 add_prefix_cmd ("backtrace", class_maintenance
, set_backtrace_cmd
, _("\
2446 Set backtrace specific variables.\n\
2447 Configure backtrace variables such as the backtrace limit"),
2448 &set_backtrace_cmdlist
, "set backtrace ",
2449 0/*allow-unknown*/, &setlist
);
2450 add_prefix_cmd ("backtrace", class_maintenance
, show_backtrace_cmd
, _("\
2451 Show backtrace specific variables\n\
2452 Show backtrace variables such as the backtrace limit"),
2453 &show_backtrace_cmdlist
, "show backtrace ",
2454 0/*allow-unknown*/, &showlist
);
2456 add_setshow_boolean_cmd ("past-main", class_obscure
,
2457 &backtrace_past_main
, _("\
2458 Set whether backtraces should continue past \"main\"."), _("\
2459 Show whether backtraces should continue past \"main\"."), _("\
2460 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
2461 the backtrace at \"main\". Set this variable if you need to see the rest\n\
2462 of the stack trace."),
2464 show_backtrace_past_main
,
2465 &set_backtrace_cmdlist
,
2466 &show_backtrace_cmdlist
);
2468 add_setshow_boolean_cmd ("past-entry", class_obscure
,
2469 &backtrace_past_entry
, _("\
2470 Set whether backtraces should continue past the entry point of a program."),
2472 Show whether backtraces should continue past the entry point of a program."),
2474 Normally there are no callers beyond the entry point of a program, so GDB\n\
2475 will terminate the backtrace there. Set this variable if you need to see\n\
2476 the rest of the stack trace."),
2478 show_backtrace_past_entry
,
2479 &set_backtrace_cmdlist
,
2480 &show_backtrace_cmdlist
);
2482 add_setshow_integer_cmd ("limit", class_obscure
,
2483 &backtrace_limit
, _("\
2484 Set an upper bound on the number of backtrace levels."), _("\
2485 Show the upper bound on the number of backtrace levels."), _("\
2486 No more than the specified number of frames can be displayed or examined.\n\
2487 Zero is unlimited."),
2489 show_backtrace_limit
,
2490 &set_backtrace_cmdlist
,
2491 &show_backtrace_cmdlist
);
2493 /* Debug this files internals. */
2494 add_setshow_zinteger_cmd ("frame", class_maintenance
, &frame_debug
, _("\
2495 Set frame debugging."), _("\
2496 Show frame debugging."), _("\
2497 When non-zero, frame specific internal debugging is enabled."),
2500 &setdebuglist
, &showdebuglist
);