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 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
25 #include "inferior.h" /* for inferior_ptid */
27 #include "gdb_assert.h"
28 #include "gdb_string.h"
29 #include "user-regs.h"
30 #include "gdb_obstack.h"
31 #include "dummy-frame.h"
32 #include "sentinel-frame.h"
36 #include "frame-unwind.h"
37 #include "frame-base.h"
42 #include "exceptions.h"
44 static struct frame_info
*get_prev_frame_1 (struct frame_info
*this_frame
);
46 /* We keep a cache of stack frames, each of which is a "struct
47 frame_info". The innermost one gets allocated (in
48 wait_for_inferior) each time the inferior stops; current_frame
49 points to it. Additional frames get allocated (in get_prev_frame)
50 as needed, and are chained through the next and prev fields. Any
51 time that the frame cache becomes invalid (most notably when we
52 execute something, but also if we change how we interpret the
53 frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
54 which reads new symbols)), we should call reinit_frame_cache. */
58 /* Level of this frame. The inner-most (youngest) frame is at level
59 0. As you move towards the outer-most (oldest) frame, the level
60 increases. This is a cached value. It could just as easily be
61 computed by counting back from the selected frame to the inner
63 /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be
64 reserved to indicate a bogus frame - one that has been created
65 just to keep GDB happy (GDB always needs a frame). For the
66 moment leave this as speculation. */
69 /* The frame's low-level unwinder and corresponding cache. The
70 low-level unwinder is responsible for unwinding register values
71 for the previous frame. The low-level unwind methods are
72 selected based on the presence, or otherwise, of register unwind
73 information such as CFI. */
75 const struct frame_unwind
*unwind
;
77 /* Cached copy of the previous frame's resume address. */
83 /* Cached copy of the previous frame's function address. */
90 /* This frame's ID. */
94 struct frame_id value
;
97 /* The frame's high-level base methods, and corresponding cache.
98 The high level base methods are selected based on the frame's
100 const struct frame_base
*base
;
103 /* Pointers to the next (down, inner, younger) and previous (up,
104 outer, older) frame_info's in the frame cache. */
105 struct frame_info
*next
; /* down, inner, younger */
107 struct frame_info
*prev
; /* up, outer, older */
109 /* The reason why we could not set PREV, or UNWIND_NO_REASON if we
110 could. Only valid when PREV_P is set. */
111 enum unwind_stop_reason stop_reason
;
114 /* Flag to control debugging. */
116 static int frame_debug
;
118 show_frame_debug (struct ui_file
*file
, int from_tty
,
119 struct cmd_list_element
*c
, const char *value
)
121 fprintf_filtered (file
, _("Frame debugging is %s.\n"), value
);
124 /* Flag to indicate whether backtraces should stop at main et.al. */
126 static int backtrace_past_main
;
128 show_backtrace_past_main (struct ui_file
*file
, int from_tty
,
129 struct cmd_list_element
*c
, const char *value
)
131 fprintf_filtered (file
, _("\
132 Whether backtraces should continue past \"main\" is %s.\n"),
136 static int backtrace_past_entry
;
138 show_backtrace_past_entry (struct ui_file
*file
, int from_tty
,
139 struct cmd_list_element
*c
, const char *value
)
141 fprintf_filtered (file
, _("\
142 Whether backtraces should continue past the entry point of a program is %s.\n"),
146 static int backtrace_limit
= INT_MAX
;
148 show_backtrace_limit (struct ui_file
*file
, int from_tty
,
149 struct cmd_list_element
*c
, const char *value
)
151 fprintf_filtered (file
, _("\
152 An upper bound on the number of backtrace levels is %s.\n"),
158 fprint_field (struct ui_file
*file
, const char *name
, int p
, CORE_ADDR addr
)
161 fprintf_unfiltered (file
, "%s=0x%s", name
, paddr_nz (addr
));
163 fprintf_unfiltered (file
, "!%s", name
);
167 fprint_frame_id (struct ui_file
*file
, struct frame_id id
)
169 fprintf_unfiltered (file
, "{");
170 fprint_field (file
, "stack", id
.stack_addr_p
, id
.stack_addr
);
171 fprintf_unfiltered (file
, ",");
172 fprint_field (file
, "code", id
.code_addr_p
, id
.code_addr
);
173 fprintf_unfiltered (file
, ",");
174 fprint_field (file
, "special", id
.special_addr_p
, id
.special_addr
);
175 fprintf_unfiltered (file
, "}");
179 fprint_frame_type (struct ui_file
*file
, enum frame_type type
)
184 fprintf_unfiltered (file
, "NORMAL_FRAME");
187 fprintf_unfiltered (file
, "DUMMY_FRAME");
190 fprintf_unfiltered (file
, "SIGTRAMP_FRAME");
193 fprintf_unfiltered (file
, "<unknown type>");
199 fprint_frame (struct ui_file
*file
, struct frame_info
*fi
)
203 fprintf_unfiltered (file
, "<NULL frame>");
206 fprintf_unfiltered (file
, "{");
207 fprintf_unfiltered (file
, "level=%d", fi
->level
);
208 fprintf_unfiltered (file
, ",");
209 fprintf_unfiltered (file
, "type=");
210 if (fi
->unwind
!= NULL
)
211 fprint_frame_type (file
, fi
->unwind
->type
);
213 fprintf_unfiltered (file
, "<unknown>");
214 fprintf_unfiltered (file
, ",");
215 fprintf_unfiltered (file
, "unwind=");
216 if (fi
->unwind
!= NULL
)
217 gdb_print_host_address (fi
->unwind
, file
);
219 fprintf_unfiltered (file
, "<unknown>");
220 fprintf_unfiltered (file
, ",");
221 fprintf_unfiltered (file
, "pc=");
222 if (fi
->next
!= NULL
&& fi
->next
->prev_pc
.p
)
223 fprintf_unfiltered (file
, "0x%s", paddr_nz (fi
->next
->prev_pc
.value
));
225 fprintf_unfiltered (file
, "<unknown>");
226 fprintf_unfiltered (file
, ",");
227 fprintf_unfiltered (file
, "id=");
229 fprint_frame_id (file
, fi
->this_id
.value
);
231 fprintf_unfiltered (file
, "<unknown>");
232 fprintf_unfiltered (file
, ",");
233 fprintf_unfiltered (file
, "func=");
234 if (fi
->next
!= NULL
&& fi
->next
->prev_func
.p
)
235 fprintf_unfiltered (file
, "0x%s", paddr_nz (fi
->next
->prev_func
.addr
));
237 fprintf_unfiltered (file
, "<unknown>");
238 fprintf_unfiltered (file
, "}");
241 /* Return a frame uniq ID that can be used to, later, re-find the
245 get_frame_id (struct frame_info
*fi
)
249 return null_frame_id
;
254 fprintf_unfiltered (gdb_stdlog
, "{ get_frame_id (fi=%d) ",
256 /* Find the unwinder. */
257 if (fi
->unwind
== NULL
)
258 fi
->unwind
= frame_unwind_find_by_frame (fi
->next
,
259 &fi
->prologue_cache
);
260 /* Find THIS frame's ID. */
261 fi
->unwind
->this_id (fi
->next
, &fi
->prologue_cache
, &fi
->this_id
.value
);
265 fprintf_unfiltered (gdb_stdlog
, "-> ");
266 fprint_frame_id (gdb_stdlog
, fi
->this_id
.value
);
267 fprintf_unfiltered (gdb_stdlog
, " }\n");
270 return fi
->this_id
.value
;
274 frame_unwind_id (struct frame_info
*next_frame
)
276 /* Use prev_frame, and not get_prev_frame. The latter will truncate
277 the frame chain, leading to this function unintentionally
278 returning a null_frame_id (e.g., when a caller requests the frame
279 ID of "main()"s caller. */
280 return get_frame_id (get_prev_frame_1 (next_frame
));
283 const struct frame_id null_frame_id
; /* All zeros. */
286 frame_id_build_special (CORE_ADDR stack_addr
, CORE_ADDR code_addr
,
287 CORE_ADDR special_addr
)
289 struct frame_id id
= null_frame_id
;
290 id
.stack_addr
= stack_addr
;
292 id
.code_addr
= code_addr
;
294 id
.special_addr
= special_addr
;
295 id
.special_addr_p
= 1;
300 frame_id_build (CORE_ADDR stack_addr
, CORE_ADDR code_addr
)
302 struct frame_id id
= null_frame_id
;
303 id
.stack_addr
= stack_addr
;
305 id
.code_addr
= code_addr
;
311 frame_id_build_wild (CORE_ADDR stack_addr
)
313 struct frame_id id
= null_frame_id
;
314 id
.stack_addr
= stack_addr
;
320 frame_id_p (struct frame_id l
)
323 /* The frame is valid iff it has a valid stack address. */
327 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_p (l=");
328 fprint_frame_id (gdb_stdlog
, l
);
329 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", p
);
335 frame_id_eq (struct frame_id l
, struct frame_id r
)
338 if (!l
.stack_addr_p
|| !r
.stack_addr_p
)
339 /* Like a NaN, if either ID is invalid, the result is false.
340 Note that a frame ID is invalid iff it is the null frame ID. */
342 else if (l
.stack_addr
!= r
.stack_addr
)
343 /* If .stack addresses are different, the frames are different. */
345 else if (!l
.code_addr_p
|| !r
.code_addr_p
)
346 /* An invalid code addr is a wild card, always succeed. */
348 else if (l
.code_addr
!= r
.code_addr
)
349 /* If .code addresses are different, the frames are different. */
351 else if (!l
.special_addr_p
|| !r
.special_addr_p
)
352 /* An invalid special addr is a wild card (or unused), always succeed. */
354 else if (l
.special_addr
== r
.special_addr
)
355 /* Frames are equal. */
362 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_eq (l=");
363 fprint_frame_id (gdb_stdlog
, l
);
364 fprintf_unfiltered (gdb_stdlog
, ",r=");
365 fprint_frame_id (gdb_stdlog
, r
);
366 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", eq
);
372 frame_id_inner (struct gdbarch
*gdbarch
, struct frame_id l
, struct frame_id r
)
375 if (!l
.stack_addr_p
|| !r
.stack_addr_p
)
376 /* Like NaN, any operation involving an invalid ID always fails. */
379 /* Only return non-zero when strictly inner than. Note that, per
380 comment in "frame.h", there is some fuzz here. Frameless
381 functions are not strictly inner than (same .stack but
382 different .code and/or .special address). */
383 inner
= gdbarch_inner_than (gdbarch
, l
.stack_addr
, r
.stack_addr
);
386 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_inner (l=");
387 fprint_frame_id (gdb_stdlog
, l
);
388 fprintf_unfiltered (gdb_stdlog
, ",r=");
389 fprint_frame_id (gdb_stdlog
, r
);
390 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", inner
);
396 frame_find_by_id (struct frame_id id
)
398 struct frame_info
*frame
;
400 /* ZERO denotes the null frame, let the caller decide what to do
401 about it. Should it instead return get_current_frame()? */
402 if (!frame_id_p (id
))
405 for (frame
= get_current_frame ();
407 frame
= get_prev_frame (frame
))
409 struct frame_id
this = get_frame_id (frame
);
410 if (frame_id_eq (id
, this))
411 /* An exact match. */
413 if (frame_id_inner (get_frame_arch (frame
), id
, this))
416 /* Either we're not yet gone far enough out along the frame
417 chain (inner(this,id)), or we're comparing frameless functions
418 (same .base, different .func, no test available). Struggle
419 on until we've definitly gone to far. */
425 frame_pc_unwind (struct frame_info
*this_frame
)
427 if (!this_frame
->prev_pc
.p
)
430 if (this_frame
->unwind
== NULL
)
432 = frame_unwind_find_by_frame (this_frame
->next
,
433 &this_frame
->prologue_cache
);
434 if (this_frame
->unwind
->prev_pc
!= NULL
)
435 /* A per-frame unwinder, prefer it. */
436 pc
= this_frame
->unwind
->prev_pc (this_frame
->next
,
437 &this_frame
->prologue_cache
);
438 else if (gdbarch_unwind_pc_p (get_frame_arch (this_frame
)))
440 /* The right way. The `pure' way. The one true way. This
441 method depends solely on the register-unwind code to
442 determine the value of registers in THIS frame, and hence
443 the value of this frame's PC (resume address). A typical
444 implementation is no more than:
446 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
447 return extract_unsigned_integer (buf, size of ISA_PC_REGNUM);
449 Note: this method is very heavily dependent on a correct
450 register-unwind implementation, it pays to fix that
451 method first; this method is frame type agnostic, since
452 it only deals with register values, it works with any
453 frame. This is all in stark contrast to the old
454 FRAME_SAVED_PC which would try to directly handle all the
455 different ways that a PC could be unwound. */
456 pc
= gdbarch_unwind_pc (get_frame_arch (this_frame
), this_frame
);
459 internal_error (__FILE__
, __LINE__
, _("No unwind_pc method"));
460 this_frame
->prev_pc
.value
= pc
;
461 this_frame
->prev_pc
.p
= 1;
463 fprintf_unfiltered (gdb_stdlog
,
464 "{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n",
466 paddr_nz (this_frame
->prev_pc
.value
));
468 return this_frame
->prev_pc
.value
;
472 frame_func_unwind (struct frame_info
*fi
, enum frame_type this_type
)
474 if (!fi
->prev_func
.p
)
476 /* Make certain that this, and not the adjacent, function is
478 CORE_ADDR addr_in_block
= frame_unwind_address_in_block (fi
, this_type
);
480 fi
->prev_func
.addr
= get_pc_function_start (addr_in_block
);
482 fprintf_unfiltered (gdb_stdlog
,
483 "{ frame_func_unwind (fi=%d) -> 0x%s }\n",
484 fi
->level
, paddr_nz (fi
->prev_func
.addr
));
486 return fi
->prev_func
.addr
;
490 get_frame_func (struct frame_info
*fi
)
492 return frame_func_unwind (fi
->next
, get_frame_type (fi
));
496 do_frame_register_read (void *src
, int regnum
, gdb_byte
*buf
)
498 frame_register_read (src
, regnum
, buf
);
503 frame_save_as_regcache (struct frame_info
*this_frame
)
505 struct regcache
*regcache
= regcache_xmalloc (get_frame_arch (this_frame
));
506 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (regcache
);
507 regcache_save (regcache
, do_frame_register_read
, this_frame
);
508 discard_cleanups (cleanups
);
513 frame_pop (struct frame_info
*this_frame
)
515 struct frame_info
*prev_frame
;
516 struct regcache
*scratch
;
517 struct cleanup
*cleanups
;
519 /* Ensure that we have a frame to pop to. */
520 prev_frame
= get_prev_frame_1 (this_frame
);
523 error (_("Cannot pop the initial frame."));
525 /* Make a copy of all the register values unwound from this frame.
526 Save them in a scratch buffer so that there isn't a race between
527 trying to extract the old values from the current regcache while
528 at the same time writing new values into that same cache. */
529 scratch
= frame_save_as_regcache (prev_frame
);
530 cleanups
= make_cleanup_regcache_xfree (scratch
);
532 /* FIXME: cagney/2003-03-16: It should be possible to tell the
533 target's register cache that it is about to be hit with a burst
534 register transfer and that the sequence of register writes should
535 be batched. The pair target_prepare_to_store() and
536 target_store_registers() kind of suggest this functionality.
537 Unfortunately, they don't implement it. Their lack of a formal
538 definition can lead to targets writing back bogus values
539 (arguably a bug in the target code mind). */
540 /* Now copy those saved registers into the current regcache.
541 Here, regcache_cpy() calls regcache_restore(). */
542 regcache_cpy (get_current_regcache (), scratch
);
543 do_cleanups (cleanups
);
545 /* We've made right mess of GDB's local state, just discard
547 reinit_frame_cache ();
551 frame_register_unwind (struct frame_info
*frame
, int regnum
,
552 int *optimizedp
, enum lval_type
*lvalp
,
553 CORE_ADDR
*addrp
, int *realnump
, gdb_byte
*bufferp
)
555 struct frame_unwind_cache
*cache
;
559 fprintf_unfiltered (gdb_stdlog
, "\
560 { frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
561 frame
->level
, regnum
,
562 frame_map_regnum_to_name (frame
, regnum
));
565 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
566 that the value proper does not need to be fetched. */
567 gdb_assert (optimizedp
!= NULL
);
568 gdb_assert (lvalp
!= NULL
);
569 gdb_assert (addrp
!= NULL
);
570 gdb_assert (realnump
!= NULL
);
571 /* gdb_assert (bufferp != NULL); */
573 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
574 is broken. There is always a frame. If there, for some reason,
575 isn't a frame, there is some pretty busted code as it should have
576 detected the problem before calling here. */
577 gdb_assert (frame
!= NULL
);
579 /* Find the unwinder. */
580 if (frame
->unwind
== NULL
)
581 frame
->unwind
= frame_unwind_find_by_frame (frame
->next
,
582 &frame
->prologue_cache
);
584 /* Ask this frame to unwind its register. See comment in
585 "frame-unwind.h" for why NEXT frame and this unwind cache are
587 frame
->unwind
->prev_register (frame
->next
, &frame
->prologue_cache
, regnum
,
588 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
592 fprintf_unfiltered (gdb_stdlog
, "->");
593 fprintf_unfiltered (gdb_stdlog
, " *optimizedp=%d", (*optimizedp
));
594 fprintf_unfiltered (gdb_stdlog
, " *lvalp=%d", (int) (*lvalp
));
595 fprintf_unfiltered (gdb_stdlog
, " *addrp=0x%s", paddr_nz ((*addrp
)));
596 fprintf_unfiltered (gdb_stdlog
, " *bufferp=");
598 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
602 const unsigned char *buf
= bufferp
;
603 fprintf_unfiltered (gdb_stdlog
, "[");
604 for (i
= 0; i
< register_size (get_frame_arch (frame
), regnum
); i
++)
605 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
606 fprintf_unfiltered (gdb_stdlog
, "]");
608 fprintf_unfiltered (gdb_stdlog
, " }\n");
613 frame_register (struct frame_info
*frame
, int regnum
,
614 int *optimizedp
, enum lval_type
*lvalp
,
615 CORE_ADDR
*addrp
, int *realnump
, gdb_byte
*bufferp
)
617 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
618 that the value proper does not need to be fetched. */
619 gdb_assert (optimizedp
!= NULL
);
620 gdb_assert (lvalp
!= NULL
);
621 gdb_assert (addrp
!= NULL
);
622 gdb_assert (realnump
!= NULL
);
623 /* gdb_assert (bufferp != NULL); */
625 /* Obtain the register value by unwinding the register from the next
626 (more inner frame). */
627 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
628 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
633 frame_unwind_register (struct frame_info
*frame
, int regnum
, gdb_byte
*buf
)
639 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
644 get_frame_register (struct frame_info
*frame
,
645 int regnum
, gdb_byte
*buf
)
647 frame_unwind_register (frame
->next
, regnum
, buf
);
651 frame_unwind_register_signed (struct frame_info
*frame
, int regnum
)
653 gdb_byte buf
[MAX_REGISTER_SIZE
];
654 frame_unwind_register (frame
, regnum
, buf
);
655 return extract_signed_integer (buf
, register_size (get_frame_arch (frame
),
660 get_frame_register_signed (struct frame_info
*frame
, int regnum
)
662 return frame_unwind_register_signed (frame
->next
, regnum
);
666 frame_unwind_register_unsigned (struct frame_info
*frame
, int regnum
)
668 gdb_byte buf
[MAX_REGISTER_SIZE
];
669 frame_unwind_register (frame
, regnum
, buf
);
670 return extract_unsigned_integer (buf
, register_size (get_frame_arch (frame
),
675 get_frame_register_unsigned (struct frame_info
*frame
, int regnum
)
677 return frame_unwind_register_unsigned (frame
->next
, regnum
);
681 put_frame_register (struct frame_info
*frame
, int regnum
,
684 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
689 frame_register (frame
, regnum
, &optim
, &lval
, &addr
, &realnum
, NULL
);
691 error (_("Attempt to assign to a value that was optimized out."));
696 /* FIXME: write_memory doesn't yet take constant buffers.
698 gdb_byte tmp
[MAX_REGISTER_SIZE
];
699 memcpy (tmp
, buf
, register_size (gdbarch
, regnum
));
700 write_memory (addr
, tmp
, register_size (gdbarch
, regnum
));
704 regcache_cooked_write (get_current_regcache (), realnum
, buf
);
707 error (_("Attempt to assign to an unmodifiable value."));
711 /* frame_register_read ()
713 Find and return the value of REGNUM for the specified stack frame.
714 The number of bytes copied is REGISTER_SIZE (REGNUM).
716 Returns 0 if the register value could not be found. */
719 frame_register_read (struct frame_info
*frame
, int regnum
,
726 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
732 get_frame_register_bytes (struct frame_info
*frame
, int regnum
,
733 CORE_ADDR offset
, int len
, gdb_byte
*myaddr
)
735 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
737 /* Skip registers wholly inside of OFFSET. */
738 while (offset
>= register_size (gdbarch
, regnum
))
740 offset
-= register_size (gdbarch
, regnum
);
747 int curr_len
= register_size (gdbarch
, regnum
) - offset
;
751 if (curr_len
== register_size (gdbarch
, regnum
))
753 if (!frame_register_read (frame
, regnum
, myaddr
))
758 gdb_byte buf
[MAX_REGISTER_SIZE
];
759 if (!frame_register_read (frame
, regnum
, buf
))
761 memcpy (myaddr
, buf
+ offset
, curr_len
);
774 put_frame_register_bytes (struct frame_info
*frame
, int regnum
,
775 CORE_ADDR offset
, int len
, const gdb_byte
*myaddr
)
777 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
779 /* Skip registers wholly inside of OFFSET. */
780 while (offset
>= register_size (gdbarch
, regnum
))
782 offset
-= register_size (gdbarch
, regnum
);
789 int curr_len
= register_size (gdbarch
, regnum
) - offset
;
793 if (curr_len
== register_size (gdbarch
, regnum
))
795 put_frame_register (frame
, regnum
, myaddr
);
799 gdb_byte buf
[MAX_REGISTER_SIZE
];
800 frame_register_read (frame
, regnum
, buf
);
801 memcpy (buf
+ offset
, myaddr
, curr_len
);
802 put_frame_register (frame
, regnum
, buf
);
812 /* Map between a frame register number and its name. A frame register
813 space is a superset of the cooked register space --- it also
814 includes builtin registers. */
817 frame_map_name_to_regnum (struct frame_info
*frame
, const char *name
, int len
)
819 return user_reg_map_name_to_regnum (get_frame_arch (frame
), name
, len
);
823 frame_map_regnum_to_name (struct frame_info
*frame
, int regnum
)
825 return user_reg_map_regnum_to_name (get_frame_arch (frame
), regnum
);
828 /* Create a sentinel frame. */
830 static struct frame_info
*
831 create_sentinel_frame (struct regcache
*regcache
)
833 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
835 /* Explicitly initialize the sentinel frame's cache. Provide it
836 with the underlying regcache. In the future additional
837 information, such as the frame's thread will be added. */
838 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
839 /* For the moment there is only one sentinel frame implementation. */
840 frame
->unwind
= sentinel_frame_unwind
;
841 /* Link this frame back to itself. The frame is self referential
842 (the unwound PC is the same as the pc), so make it so. */
844 /* Make the sentinel frame's ID valid, but invalid. That way all
845 comparisons with it should fail. */
846 frame
->this_id
.p
= 1;
847 frame
->this_id
.value
= null_frame_id
;
850 fprintf_unfiltered (gdb_stdlog
, "{ create_sentinel_frame (...) -> ");
851 fprint_frame (gdb_stdlog
, frame
);
852 fprintf_unfiltered (gdb_stdlog
, " }\n");
857 /* Info about the innermost stack frame (contents of FP register) */
859 static struct frame_info
*current_frame
;
861 /* Cache for frame addresses already read by gdb. Valid only while
862 inferior is stopped. Control variables for the frame cache should
863 be local to this module. */
865 static struct obstack frame_cache_obstack
;
868 frame_obstack_zalloc (unsigned long size
)
870 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
871 memset (data
, 0, size
);
875 /* Return the innermost (currently executing) stack frame. This is
876 split into two functions. The function unwind_to_current_frame()
877 is wrapped in catch exceptions so that, even when the unwind of the
878 sentinel frame fails, the function still returns a stack frame. */
881 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
883 struct frame_info
*frame
= get_prev_frame (args
);
884 /* A sentinel frame can fail to unwind, e.g., because its PC value
885 lands in somewhere like start. */
888 current_frame
= frame
;
893 get_current_frame (void)
895 /* First check, and report, the lack of registers. Having GDB
896 report "No stack!" or "No memory" when the target doesn't even
897 have registers is very confusing. Besides, "printcmd.exp"
898 explicitly checks that ``print $pc'' with no registers prints "No
900 if (!target_has_registers
)
901 error (_("No registers."));
902 if (!target_has_stack
)
903 error (_("No stack."));
904 if (!target_has_memory
)
905 error (_("No memory."));
906 if (current_frame
== NULL
)
908 struct frame_info
*sentinel_frame
=
909 create_sentinel_frame (get_current_regcache ());
910 if (catch_exceptions (uiout
, unwind_to_current_frame
, sentinel_frame
,
911 RETURN_MASK_ERROR
) != 0)
913 /* Oops! Fake a current frame? Is this useful? It has a PC
914 of zero, for instance. */
915 current_frame
= sentinel_frame
;
918 return current_frame
;
921 /* The "selected" stack frame is used by default for local and arg
922 access. May be zero, for no selected frame. */
924 static struct frame_info
*selected_frame
;
926 /* Return the selected frame. Always non-NULL (unless there isn't an
927 inferior sufficient for creating a frame) in which case an error is
931 get_selected_frame (const char *message
)
933 if (selected_frame
== NULL
)
935 if (message
!= NULL
&& (!target_has_registers
937 || !target_has_memory
))
938 error (("%s"), message
);
939 /* Hey! Don't trust this. It should really be re-finding the
940 last selected frame of the currently selected thread. This,
941 though, is better than nothing. */
942 select_frame (get_current_frame ());
944 /* There is always a frame. */
945 gdb_assert (selected_frame
!= NULL
);
946 return selected_frame
;
949 /* This is a variant of get_selected_frame() which can be called when
950 the inferior does not have a frame; in that case it will return
951 NULL instead of calling error(). */
954 deprecated_safe_get_selected_frame (void)
956 if (!target_has_registers
|| !target_has_stack
|| !target_has_memory
)
958 return get_selected_frame (NULL
);
961 /* Select frame FI (or NULL - to invalidate the current frame). */
964 select_frame (struct frame_info
*fi
)
969 /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
970 frame is being invalidated. */
971 if (deprecated_selected_frame_level_changed_hook
)
972 deprecated_selected_frame_level_changed_hook (frame_relative_level (fi
));
974 /* FIXME: kseitz/2002-08-28: It would be nice to call
975 selected_frame_level_changed_event() right here, but due to limitations
976 in the current interfaces, we would end up flooding UIs with events
977 because select_frame() is used extensively internally.
979 Once we have frame-parameterized frame (and frame-related) commands,
980 the event notification can be moved here, since this function will only
981 be called when the user's selected frame is being changed. */
983 /* Ensure that symbols for this frame are read in. Also, determine the
984 source language of this frame, and switch to it if desired. */
987 /* We retrieve the frame's symtab by using the frame PC. However
988 we cannot use the frame PC as-is, because it usually points to
989 the instruction following the "call", which is sometimes the
990 first instruction of another function. So we rely on
991 get_frame_address_in_block() which provides us with a PC which
992 is guaranteed to be inside the frame's code block. */
993 s
= find_pc_symtab (get_frame_address_in_block (fi
));
995 && s
->language
!= current_language
->la_language
996 && s
->language
!= language_unknown
997 && language_mode
== language_mode_auto
)
999 set_language (s
->language
);
1004 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
1005 Always returns a non-NULL value. */
1008 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
1010 struct frame_info
*fi
;
1014 fprintf_unfiltered (gdb_stdlog
,
1015 "{ create_new_frame (addr=0x%s, pc=0x%s) ",
1016 paddr_nz (addr
), paddr_nz (pc
));
1019 fi
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1021 fi
->next
= create_sentinel_frame (get_current_regcache ());
1023 /* Select/initialize both the unwind function and the frame's type
1025 fi
->unwind
= frame_unwind_find_by_frame (fi
->next
, &fi
->prologue_cache
);
1028 deprecated_update_frame_base_hack (fi
, addr
);
1029 deprecated_update_frame_pc_hack (fi
, pc
);
1033 fprintf_unfiltered (gdb_stdlog
, "-> ");
1034 fprint_frame (gdb_stdlog
, fi
);
1035 fprintf_unfiltered (gdb_stdlog
, " }\n");
1041 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
1042 innermost frame). Be careful to not fall off the bottom of the
1043 frame chain and onto the sentinel frame. */
1046 get_next_frame (struct frame_info
*this_frame
)
1048 if (this_frame
->level
> 0)
1049 return this_frame
->next
;
1054 /* Observer for the target_changed event. */
1057 frame_observer_target_changed (struct target_ops
*target
)
1059 reinit_frame_cache ();
1062 /* Flush the entire frame cache. */
1065 reinit_frame_cache (void)
1067 struct frame_info
*fi
;
1069 /* Tear down all frame caches. */
1070 for (fi
= current_frame
; fi
!= NULL
; fi
= fi
->prev
)
1072 if (fi
->prologue_cache
&& fi
->unwind
->dealloc_cache
)
1073 fi
->unwind
->dealloc_cache (fi
, fi
->prologue_cache
);
1074 if (fi
->base_cache
&& fi
->base
->unwind
->dealloc_cache
)
1075 fi
->base
->unwind
->dealloc_cache (fi
, fi
->base_cache
);
1078 /* Since we can't really be sure what the first object allocated was */
1079 obstack_free (&frame_cache_obstack
, 0);
1080 obstack_init (&frame_cache_obstack
);
1082 if (current_frame
!= NULL
)
1083 annotate_frames_invalid ();
1085 current_frame
= NULL
; /* Invalidate cache */
1086 select_frame (NULL
);
1088 fprintf_unfiltered (gdb_stdlog
, "{ reinit_frame_cache () }\n");
1091 /* Find where a register is saved (in memory or another register).
1092 The result of frame_register_unwind is just where it is saved
1093 relative to this particular frame. */
1096 frame_register_unwind_location (struct frame_info
*this_frame
, int regnum
,
1097 int *optimizedp
, enum lval_type
*lvalp
,
1098 CORE_ADDR
*addrp
, int *realnump
)
1100 gdb_assert (this_frame
== NULL
|| this_frame
->level
>= 0);
1102 while (this_frame
!= NULL
)
1104 frame_register_unwind (this_frame
, regnum
, optimizedp
, lvalp
,
1105 addrp
, realnump
, NULL
);
1110 if (*lvalp
!= lval_register
)
1114 this_frame
= get_next_frame (this_frame
);
1118 /* Return a "struct frame_info" corresponding to the frame that called
1119 THIS_FRAME. Returns NULL if there is no such frame.
1121 Unlike get_prev_frame, this function always tries to unwind the
1124 static struct frame_info
*
1125 get_prev_frame_1 (struct frame_info
*this_frame
)
1127 struct frame_info
*prev_frame
;
1128 struct frame_id this_id
;
1129 struct gdbarch
*gdbarch
;
1131 gdb_assert (this_frame
!= NULL
);
1132 gdbarch
= get_frame_arch (this_frame
);
1136 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame_1 (this_frame=");
1137 if (this_frame
!= NULL
)
1138 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1140 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1141 fprintf_unfiltered (gdb_stdlog
, ") ");
1144 /* Only try to do the unwind once. */
1145 if (this_frame
->prev_p
)
1149 fprintf_unfiltered (gdb_stdlog
, "-> ");
1150 fprint_frame (gdb_stdlog
, this_frame
->prev
);
1151 fprintf_unfiltered (gdb_stdlog
, " // cached \n");
1153 return this_frame
->prev
;
1155 this_frame
->prev_p
= 1;
1156 this_frame
->stop_reason
= UNWIND_NO_REASON
;
1158 /* Check that this frame's ID was valid. If it wasn't, don't try to
1159 unwind to the prev frame. Be careful to not apply this test to
1160 the sentinel frame. */
1161 this_id
= get_frame_id (this_frame
);
1162 if (this_frame
->level
>= 0 && !frame_id_p (this_id
))
1166 fprintf_unfiltered (gdb_stdlog
, "-> ");
1167 fprint_frame (gdb_stdlog
, NULL
);
1168 fprintf_unfiltered (gdb_stdlog
, " // this ID is NULL }\n");
1170 this_frame
->stop_reason
= UNWIND_NULL_ID
;
1174 /* Check that this frame's ID isn't inner to (younger, below, next)
1175 the next frame. This happens when a frame unwind goes backwards.
1176 Exclude signal trampolines (due to sigaltstack the frame ID can
1177 go backwards) and sentinel frames (the test is meaningless). */
1178 if (this_frame
->next
->level
>= 0
1179 && this_frame
->next
->unwind
->type
!= SIGTRAMP_FRAME
1180 && frame_id_inner (get_frame_arch (this_frame
), this_id
,
1181 get_frame_id (this_frame
->next
)))
1185 fprintf_unfiltered (gdb_stdlog
, "-> ");
1186 fprint_frame (gdb_stdlog
, NULL
);
1187 fprintf_unfiltered (gdb_stdlog
, " // this frame ID is inner }\n");
1189 this_frame
->stop_reason
= UNWIND_INNER_ID
;
1193 /* Check that this and the next frame are not identical. If they
1194 are, there is most likely a stack cycle. As with the inner-than
1195 test above, avoid comparing the inner-most and sentinel frames. */
1196 if (this_frame
->level
> 0
1197 && frame_id_eq (this_id
, get_frame_id (this_frame
->next
)))
1201 fprintf_unfiltered (gdb_stdlog
, "-> ");
1202 fprint_frame (gdb_stdlog
, NULL
);
1203 fprintf_unfiltered (gdb_stdlog
, " // this frame has same ID }\n");
1205 this_frame
->stop_reason
= UNWIND_SAME_ID
;
1209 /* Check that this and the next frame do not unwind the PC register
1210 to the same memory location. If they do, then even though they
1211 have different frame IDs, the new frame will be bogus; two
1212 functions can't share a register save slot for the PC. This can
1213 happen when the prologue analyzer finds a stack adjustment, but
1216 This check does assume that the "PC register" is roughly a
1217 traditional PC, even if the gdbarch_unwind_pc method adjusts
1218 it (we do not rely on the value, only on the unwound PC being
1219 dependent on this value). A potential improvement would be
1220 to have the frame prev_pc method and the gdbarch unwind_pc
1221 method set the same lval and location information as
1222 frame_register_unwind. */
1223 if (this_frame
->level
> 0
1224 && gdbarch_pc_regnum (gdbarch
) >= 0
1225 && get_frame_type (this_frame
) == NORMAL_FRAME
1226 && get_frame_type (this_frame
->next
) == NORMAL_FRAME
)
1228 int optimized
, realnum
, nrealnum
;
1229 enum lval_type lval
, nlval
;
1230 CORE_ADDR addr
, naddr
;
1232 frame_register_unwind_location (this_frame
,
1233 gdbarch_pc_regnum (gdbarch
),
1234 &optimized
, &lval
, &addr
, &realnum
);
1235 frame_register_unwind_location (get_next_frame (this_frame
),
1236 gdbarch_pc_regnum (gdbarch
),
1237 &optimized
, &nlval
, &naddr
, &nrealnum
);
1239 if ((lval
== lval_memory
&& lval
== nlval
&& addr
== naddr
)
1240 || (lval
== lval_register
&& lval
== nlval
&& realnum
== nrealnum
))
1244 fprintf_unfiltered (gdb_stdlog
, "-> ");
1245 fprint_frame (gdb_stdlog
, NULL
);
1246 fprintf_unfiltered (gdb_stdlog
, " // no saved PC }\n");
1249 this_frame
->stop_reason
= UNWIND_NO_SAVED_PC
;
1250 this_frame
->prev
= NULL
;
1255 /* Allocate the new frame but do not wire it in to the frame chain.
1256 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1257 frame->next to pull some fancy tricks (of course such code is, by
1258 definition, recursive). Try to prevent it.
1260 There is no reason to worry about memory leaks, should the
1261 remainder of the function fail. The allocated memory will be
1262 quickly reclaimed when the frame cache is flushed, and the `we've
1263 been here before' check above will stop repeated memory
1264 allocation calls. */
1265 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1266 prev_frame
->level
= this_frame
->level
+ 1;
1268 /* Don't yet compute ->unwind (and hence ->type). It is computed
1269 on-demand in get_frame_type, frame_register_unwind, and
1272 /* Don't yet compute the frame's ID. It is computed on-demand by
1275 /* The unwound frame ID is validate at the start of this function,
1276 as part of the logic to decide if that frame should be further
1277 unwound, and not here while the prev frame is being created.
1278 Doing this makes it possible for the user to examine a frame that
1279 has an invalid frame ID.
1281 Some very old VAX code noted: [...] For the sake of argument,
1282 suppose that the stack is somewhat trashed (which is one reason
1283 that "info frame" exists). So, return 0 (indicating we don't
1284 know the address of the arglist) if we don't know what frame this
1288 this_frame
->prev
= prev_frame
;
1289 prev_frame
->next
= this_frame
;
1293 fprintf_unfiltered (gdb_stdlog
, "-> ");
1294 fprint_frame (gdb_stdlog
, prev_frame
);
1295 fprintf_unfiltered (gdb_stdlog
, " }\n");
1301 /* Debug routine to print a NULL frame being returned. */
1304 frame_debug_got_null_frame (struct ui_file
*file
,
1305 struct frame_info
*this_frame
,
1310 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame (this_frame=");
1311 if (this_frame
!= NULL
)
1312 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1314 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1315 fprintf_unfiltered (gdb_stdlog
, ") -> // %s}\n", reason
);
1319 /* Is this (non-sentinel) frame in the "main"() function? */
1322 inside_main_func (struct frame_info
*this_frame
)
1324 struct minimal_symbol
*msymbol
;
1327 if (symfile_objfile
== 0)
1329 msymbol
= lookup_minimal_symbol (main_name (), NULL
, symfile_objfile
);
1330 if (msymbol
== NULL
)
1332 /* Make certain that the code, and not descriptor, address is
1334 maddr
= gdbarch_convert_from_func_ptr_addr (get_frame_arch (this_frame
),
1335 SYMBOL_VALUE_ADDRESS (msymbol
),
1337 return maddr
== get_frame_func (this_frame
);
1340 /* Test whether THIS_FRAME is inside the process entry point function. */
1343 inside_entry_func (struct frame_info
*this_frame
)
1345 return (get_frame_func (this_frame
) == entry_point_address ());
1348 /* Return a structure containing various interesting information about
1349 the frame that called THIS_FRAME. Returns NULL if there is entier
1350 no such frame or the frame fails any of a set of target-independent
1351 condition that should terminate the frame chain (e.g., as unwinding
1354 This function should not contain target-dependent tests, such as
1355 checking whether the program-counter is zero. */
1358 get_prev_frame (struct frame_info
*this_frame
)
1360 struct frame_info
*prev_frame
;
1362 /* Return the inner-most frame, when the caller passes in NULL. */
1363 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1364 caller should have previously obtained a valid frame using
1365 get_selected_frame() and then called this code - only possibility
1366 I can think of is code behaving badly.
1368 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1369 block_innermost_frame(). It does the sequence: frame = NULL;
1370 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1371 it couldn't be written better, I don't know.
1373 NOTE: cagney/2003-01-11: I suspect what is happening in
1374 block_innermost_frame() is, when the target has no state
1375 (registers, memory, ...), it is still calling this function. The
1376 assumption being that this function will return NULL indicating
1377 that a frame isn't possible, rather than checking that the target
1378 has state and then calling get_current_frame() and
1379 get_prev_frame(). This is a guess mind. */
1380 if (this_frame
== NULL
)
1382 /* NOTE: cagney/2002-11-09: There was a code segment here that
1383 would error out when CURRENT_FRAME was NULL. The comment
1384 that went with it made the claim ...
1386 ``This screws value_of_variable, which just wants a nice
1387 clean NULL return from block_innermost_frame if there are no
1388 frames. I don't think I've ever seen this message happen
1389 otherwise. And returning NULL here is a perfectly legitimate
1392 Per the above, this code shouldn't even be called with a NULL
1394 frame_debug_got_null_frame (gdb_stdlog
, this_frame
, "this_frame NULL");
1395 return current_frame
;
1398 /* There is always a frame. If this assertion fails, suspect that
1399 something should be calling get_selected_frame() or
1400 get_current_frame(). */
1401 gdb_assert (this_frame
!= NULL
);
1403 /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much
1404 sense to stop unwinding at a dummy frame. One place where a dummy
1405 frame may have an address "inside_main_func" is on HPUX. On HPUX, the
1406 pcsqh register (space register for the instruction at the head of the
1407 instruction queue) cannot be written directly; the only way to set it
1408 is to branch to code that is in the target space. In order to implement
1409 frame dummies on HPUX, the called function is made to jump back to where
1410 the inferior was when the user function was called. If gdb was inside
1411 the main function when we created the dummy frame, the dummy frame will
1412 point inside the main function. */
1413 if (this_frame
->level
>= 0
1414 && get_frame_type (this_frame
) != DUMMY_FRAME
1415 && !backtrace_past_main
1416 && inside_main_func (this_frame
))
1417 /* Don't unwind past main(). Note, this is done _before_ the
1418 frame has been marked as previously unwound. That way if the
1419 user later decides to enable unwinds past main(), that will
1420 automatically happen. */
1422 frame_debug_got_null_frame (gdb_stdlog
, this_frame
, "inside main func");
1426 /* If the user's backtrace limit has been exceeded, stop. We must
1427 add two to the current level; one of those accounts for backtrace_limit
1428 being 1-based and the level being 0-based, and the other accounts for
1429 the level of the new frame instead of the level of the current
1431 if (this_frame
->level
+ 2 > backtrace_limit
)
1433 frame_debug_got_null_frame (gdb_stdlog
, this_frame
,
1434 "backtrace limit exceeded");
1438 /* If we're already inside the entry function for the main objfile,
1439 then it isn't valid. Don't apply this test to a dummy frame -
1440 dummy frame PCs typically land in the entry func. Don't apply
1441 this test to the sentinel frame. Sentinel frames should always
1442 be allowed to unwind. */
1443 /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
1444 wasn't checking for "main" in the minimal symbols. With that
1445 fixed asm-source tests now stop in "main" instead of halting the
1446 backtrace in weird and wonderful ways somewhere inside the entry
1447 file. Suspect that tests for inside the entry file/func were
1448 added to work around that (now fixed) case. */
1449 /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
1450 suggested having the inside_entry_func test use the
1451 inside_main_func() msymbol trick (along with entry_point_address()
1452 I guess) to determine the address range of the start function.
1453 That should provide a far better stopper than the current
1455 /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler
1456 applied tail-call optimizations to main so that a function called
1457 from main returns directly to the caller of main. Since we don't
1458 stop at main, we should at least stop at the entry point of the
1460 if (!backtrace_past_entry
1461 && get_frame_type (this_frame
) != DUMMY_FRAME
&& this_frame
->level
>= 0
1462 && inside_entry_func (this_frame
))
1464 frame_debug_got_null_frame (gdb_stdlog
, this_frame
, "inside entry func");
1468 /* Assume that the only way to get a zero PC is through something
1469 like a SIGSEGV or a dummy frame, and hence that NORMAL frames
1470 will never unwind a zero PC. */
1471 if (this_frame
->level
> 0
1472 && get_frame_type (this_frame
) == NORMAL_FRAME
1473 && get_frame_type (get_next_frame (this_frame
)) == NORMAL_FRAME
1474 && get_frame_pc (this_frame
) == 0)
1476 frame_debug_got_null_frame (gdb_stdlog
, this_frame
, "zero PC");
1480 return get_prev_frame_1 (this_frame
);
1484 get_frame_pc (struct frame_info
*frame
)
1486 gdb_assert (frame
->next
!= NULL
);
1487 return frame_pc_unwind (frame
->next
);
1490 /* Return an address that falls within NEXT_FRAME's caller's code
1491 block, assuming that the caller is a THIS_TYPE frame. */
1494 frame_unwind_address_in_block (struct frame_info
*next_frame
,
1495 enum frame_type this_type
)
1497 /* A draft address. */
1498 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
1500 /* If NEXT_FRAME was called by a signal frame or dummy frame, then
1501 we shold not adjust the unwound PC. These frames may not call
1502 their next frame in the normal way; the operating system or GDB
1503 may have pushed their resume address manually onto the stack, so
1504 it may be the very first instruction. Even if the resume address
1505 was not manually pushed, they expect to be returned to. */
1506 if (this_type
!= NORMAL_FRAME
)
1509 /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
1510 and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
1511 frame's PC ends up pointing at the instruction fallowing the
1512 "call". Adjust that PC value so that it falls on the call
1513 instruction (which, hopefully, falls within THIS frame's code
1514 block). So far it's proved to be a very good approximation. See
1515 get_frame_type() for why ->type can't be used. */
1516 if (next_frame
->level
>= 0
1517 && get_frame_type (next_frame
) == NORMAL_FRAME
)
1523 get_frame_address_in_block (struct frame_info
*this_frame
)
1525 return frame_unwind_address_in_block (this_frame
->next
,
1526 get_frame_type (this_frame
));
1530 pc_notcurrent (struct frame_info
*frame
)
1532 /* If FRAME is not the innermost frame, that normally means that
1533 FRAME->pc points at the return instruction (which is *after* the
1534 call instruction), and we want to get the line containing the
1535 call (because the call is where the user thinks the program is).
1536 However, if the next frame is either a SIGTRAMP_FRAME or a
1537 DUMMY_FRAME, then the next frame will contain a saved interrupt
1538 PC and such a PC indicates the current (rather than next)
1539 instruction/line, consequently, for such cases, want to get the
1540 line containing fi->pc. */
1541 struct frame_info
*next
= get_next_frame (frame
);
1542 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1547 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1549 (*sal
) = find_pc_line (get_frame_pc (frame
), pc_notcurrent (frame
));
1552 /* Per "frame.h", return the ``address'' of the frame. Code should
1553 really be using get_frame_id(). */
1555 get_frame_base (struct frame_info
*fi
)
1557 return get_frame_id (fi
).stack_addr
;
1560 /* High-level offsets into the frame. Used by the debug info. */
1563 get_frame_base_address (struct frame_info
*fi
)
1565 if (get_frame_type (fi
) != NORMAL_FRAME
)
1567 if (fi
->base
== NULL
)
1568 fi
->base
= frame_base_find_by_frame (fi
->next
);
1569 /* Sneaky: If the low-level unwind and high-level base code share a
1570 common unwinder, let them share the prologue cache. */
1571 if (fi
->base
->unwind
== fi
->unwind
)
1572 return fi
->base
->this_base (fi
->next
, &fi
->prologue_cache
);
1573 return fi
->base
->this_base (fi
->next
, &fi
->base_cache
);
1577 get_frame_locals_address (struct frame_info
*fi
)
1580 if (get_frame_type (fi
) != NORMAL_FRAME
)
1582 /* If there isn't a frame address method, find it. */
1583 if (fi
->base
== NULL
)
1584 fi
->base
= frame_base_find_by_frame (fi
->next
);
1585 /* Sneaky: If the low-level unwind and high-level base code share a
1586 common unwinder, let them share the prologue cache. */
1587 if (fi
->base
->unwind
== fi
->unwind
)
1588 cache
= &fi
->prologue_cache
;
1590 cache
= &fi
->base_cache
;
1591 return fi
->base
->this_locals (fi
->next
, cache
);
1595 get_frame_args_address (struct frame_info
*fi
)
1598 if (get_frame_type (fi
) != NORMAL_FRAME
)
1600 /* If there isn't a frame address method, find it. */
1601 if (fi
->base
== NULL
)
1602 fi
->base
= frame_base_find_by_frame (fi
->next
);
1603 /* Sneaky: If the low-level unwind and high-level base code share a
1604 common unwinder, let them share the prologue cache. */
1605 if (fi
->base
->unwind
== fi
->unwind
)
1606 cache
= &fi
->prologue_cache
;
1608 cache
= &fi
->base_cache
;
1609 return fi
->base
->this_args (fi
->next
, cache
);
1612 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1613 or -1 for a NULL frame. */
1616 frame_relative_level (struct frame_info
*fi
)
1625 get_frame_type (struct frame_info
*frame
)
1627 if (frame
->unwind
== NULL
)
1628 /* Initialize the frame's unwinder because that's what
1629 provides the frame's type. */
1630 frame
->unwind
= frame_unwind_find_by_frame (frame
->next
,
1631 &frame
->prologue_cache
);
1632 return frame
->unwind
->type
;
1636 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
1639 fprintf_unfiltered (gdb_stdlog
,
1640 "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
1641 frame
->level
, paddr_nz (pc
));
1642 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
1643 maintaining a locally allocated frame object. Since such frames
1644 are not in the frame chain, it isn't possible to assume that the
1645 frame has a next. Sigh. */
1646 if (frame
->next
!= NULL
)
1648 /* While we're at it, update this frame's cached PC value, found
1649 in the next frame. Oh for the day when "struct frame_info"
1650 is opaque and this hack on hack can just go away. */
1651 frame
->next
->prev_pc
.value
= pc
;
1652 frame
->next
->prev_pc
.p
= 1;
1657 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
1660 fprintf_unfiltered (gdb_stdlog
,
1661 "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
1662 frame
->level
, paddr_nz (base
));
1663 /* See comment in "frame.h". */
1664 frame
->this_id
.value
.stack_addr
= base
;
1667 /* Memory access methods. */
1670 get_frame_memory (struct frame_info
*this_frame
, CORE_ADDR addr
,
1671 gdb_byte
*buf
, int len
)
1673 read_memory (addr
, buf
, len
);
1677 get_frame_memory_signed (struct frame_info
*this_frame
, CORE_ADDR addr
,
1680 return read_memory_integer (addr
, len
);
1684 get_frame_memory_unsigned (struct frame_info
*this_frame
, CORE_ADDR addr
,
1687 return read_memory_unsigned_integer (addr
, len
);
1691 safe_frame_unwind_memory (struct frame_info
*this_frame
,
1692 CORE_ADDR addr
, gdb_byte
*buf
, int len
)
1694 /* NOTE: target_read_memory returns zero on success! */
1695 return !target_read_memory (addr
, buf
, len
);
1698 /* Architecture method. */
1701 get_frame_arch (struct frame_info
*this_frame
)
1703 return current_gdbarch
;
1706 /* Stack pointer methods. */
1709 get_frame_sp (struct frame_info
*this_frame
)
1711 return frame_sp_unwind (this_frame
->next
);
1715 frame_sp_unwind (struct frame_info
*next_frame
)
1717 struct gdbarch
*gdbarch
= get_frame_arch (next_frame
);
1718 /* Normality - an architecture that provides a way of obtaining any
1719 frame inner-most address. */
1720 if (gdbarch_unwind_sp_p (gdbarch
))
1721 return gdbarch_unwind_sp (gdbarch
, next_frame
);
1722 /* Now things are really are grim. Hope that the value returned by
1723 the gdbarch_sp_regnum register is meaningful. */
1724 if (gdbarch_sp_regnum (gdbarch
) >= 0)
1725 return frame_unwind_register_unsigned (next_frame
,
1726 gdbarch_sp_regnum (gdbarch
));
1727 internal_error (__FILE__
, __LINE__
, _("Missing unwind SP method"));
1730 /* Return the reason why we can't unwind past FRAME. */
1732 enum unwind_stop_reason
1733 get_frame_unwind_stop_reason (struct frame_info
*frame
)
1735 /* If we haven't tried to unwind past this point yet, then assume
1736 that unwinding would succeed. */
1737 if (frame
->prev_p
== 0)
1738 return UNWIND_NO_REASON
;
1740 /* Otherwise, we set a reason when we succeeded (or failed) to
1742 return frame
->stop_reason
;
1745 /* Return a string explaining REASON. */
1748 frame_stop_reason_string (enum unwind_stop_reason reason
)
1752 case UNWIND_NULL_ID
:
1753 return _("unwinder did not report frame ID");
1755 case UNWIND_INNER_ID
:
1756 return _("previous frame inner to this frame (corrupt stack?)");
1758 case UNWIND_SAME_ID
:
1759 return _("previous frame identical to this frame (corrupt stack?)");
1761 case UNWIND_NO_SAVED_PC
:
1762 return _("frame did not save the PC");
1764 case UNWIND_NO_REASON
:
1765 case UNWIND_FIRST_ERROR
:
1767 internal_error (__FILE__
, __LINE__
,
1768 "Invalid frame stop reason");
1772 extern initialize_file_ftype _initialize_frame
; /* -Wmissing-prototypes */
1774 static struct cmd_list_element
*set_backtrace_cmdlist
;
1775 static struct cmd_list_element
*show_backtrace_cmdlist
;
1778 set_backtrace_cmd (char *args
, int from_tty
)
1780 help_list (set_backtrace_cmdlist
, "set backtrace ", -1, gdb_stdout
);
1784 show_backtrace_cmd (char *args
, int from_tty
)
1786 cmd_show_list (show_backtrace_cmdlist
, from_tty
, "");
1790 _initialize_frame (void)
1792 obstack_init (&frame_cache_obstack
);
1794 observer_attach_target_changed (frame_observer_target_changed
);
1796 add_prefix_cmd ("backtrace", class_maintenance
, set_backtrace_cmd
, _("\
1797 Set backtrace specific variables.\n\
1798 Configure backtrace variables such as the backtrace limit"),
1799 &set_backtrace_cmdlist
, "set backtrace ",
1800 0/*allow-unknown*/, &setlist
);
1801 add_prefix_cmd ("backtrace", class_maintenance
, show_backtrace_cmd
, _("\
1802 Show backtrace specific variables\n\
1803 Show backtrace variables such as the backtrace limit"),
1804 &show_backtrace_cmdlist
, "show backtrace ",
1805 0/*allow-unknown*/, &showlist
);
1807 add_setshow_boolean_cmd ("past-main", class_obscure
,
1808 &backtrace_past_main
, _("\
1809 Set whether backtraces should continue past \"main\"."), _("\
1810 Show whether backtraces should continue past \"main\"."), _("\
1811 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1812 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1813 of the stack trace."),
1815 show_backtrace_past_main
,
1816 &set_backtrace_cmdlist
,
1817 &show_backtrace_cmdlist
);
1819 add_setshow_boolean_cmd ("past-entry", class_obscure
,
1820 &backtrace_past_entry
, _("\
1821 Set whether backtraces should continue past the entry point of a program."),
1823 Show whether backtraces should continue past the entry point of a program."),
1825 Normally there are no callers beyond the entry point of a program, so GDB\n\
1826 will terminate the backtrace there. Set this variable if you need to see \n\
1827 the rest of the stack trace."),
1829 show_backtrace_past_entry
,
1830 &set_backtrace_cmdlist
,
1831 &show_backtrace_cmdlist
);
1833 add_setshow_integer_cmd ("limit", class_obscure
,
1834 &backtrace_limit
, _("\
1835 Set an upper bound on the number of backtrace levels."), _("\
1836 Show the upper bound on the number of backtrace levels."), _("\
1837 No more than the specified number of frames can be displayed or examined.\n\
1838 Zero is unlimited."),
1840 show_backtrace_limit
,
1841 &set_backtrace_cmdlist
,
1842 &show_backtrace_cmdlist
);
1844 /* Debug this files internals. */
1845 add_setshow_zinteger_cmd ("frame", class_maintenance
, &frame_debug
, _("\
1846 Set frame debugging."), _("\
1847 Show frame debugging."), _("\
1848 When non-zero, frame specific internal debugging is enabled."),
1851 &setdebuglist
, &showdebuglist
);