1 /* Cache and manage frames for GDB, the GNU debugger.
3 Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000,
4 2001, 2002, 2003 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 2 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, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
27 #include "inferior.h" /* for inferior_ptid */
29 #include "gdb_assert.h"
30 #include "gdb_string.h"
31 #include "builtin-regs.h"
32 #include "gdb_obstack.h"
33 #include "dummy-frame.h"
34 #include "sentinel-frame.h"
38 #include "frame-unwind.h"
39 #include "frame-base.h"
43 /* Flag to control debugging. */
45 static int frame_debug
;
47 /* Flag to indicate whether backtraces should stop at main. */
49 static int backtrace_below_main
;
51 /* Return a frame uniq ID that can be used to, later, re-find the
55 get_frame_id (struct frame_info
*fi
)
63 gdb_assert (!legacy_frame_p (current_gdbarch
));
64 /* Find THIS frame's ID. */
65 fi
->unwind
->this_id (fi
->next
, &fi
->prologue_cache
, &fi
->id
);
67 /* FIXME: cagney/2002-12-18: Instead of this hack, should only
68 store the frame ID in PREV_FRAME. Unfortunatly, some
69 architectures (HP/UX) still reply on EXTRA_FRAME_INFO and,
70 hence, still poke at the "struct frame_info" object directly. */
71 fi
->frame
= fi
->id
.base
;
73 return frame_id_build (fi
->frame
, fi
->pc
);
76 const struct frame_id null_frame_id
; /* All zeros. */
79 frame_id_build (CORE_ADDR base
, CORE_ADDR func_or_pc
)
88 frame_id_p (struct frame_id l
)
90 /* The .func can be NULL but the .base cannot. */
95 frame_id_eq (struct frame_id l
, struct frame_id r
)
97 /* If .base is different, the frames are different. */
100 /* Add a test to check that the frame ID's are for the same function
106 frame_id_inner (struct frame_id l
, struct frame_id r
)
108 /* Only return non-zero when strictly inner than. Note that, per
109 comment in "frame.h", there is some fuzz here. Frameless
110 functions are not strictly inner than (same .base but different
112 return INNER_THAN (l
.base
, r
.base
);
116 frame_find_by_id (struct frame_id id
)
118 struct frame_info
*frame
;
120 /* ZERO denotes the null frame, let the caller decide what to do
121 about it. Should it instead return get_current_frame()? */
122 if (!frame_id_p (id
))
125 for (frame
= get_current_frame ();
127 frame
= get_prev_frame (frame
))
129 struct frame_id
this = get_frame_id (frame
);
130 if (frame_id_eq (id
, this))
131 /* An exact match. */
133 if (frame_id_inner (id
, this))
136 /* Either, we're not yet gone far enough out along the frame
137 chain (inner(this,id), or we're comparing frameless functions
138 (same .base, different .func, no test available). Struggle
139 on until we've definitly gone to far. */
145 frame_pc_unwind (struct frame_info
*this_frame
)
147 if (!this_frame
->pc_unwind_cache_p
)
150 if (gdbarch_unwind_pc_p (current_gdbarch
))
152 /* The right way. The `pure' way. The one true way. This
153 method depends solely on the register-unwind code to
154 determine the value of registers in THIS frame, and hence
155 the value of this frame's PC (resume address). A typical
156 implementation is no more than:
158 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
159 return extract_address (buf, size of ISA_PC_REGNUM);
161 Note: this method is very heavily dependent on a correct
162 register-unwind implementation, it pays to fix that
163 method first; this method is frame type agnostic, since
164 it only deals with register values, it works with any
165 frame. This is all in stark contrast to the old
166 FRAME_SAVED_PC which would try to directly handle all the
167 different ways that a PC could be unwound. */
168 pc
= gdbarch_unwind_pc (current_gdbarch
, this_frame
);
170 else if (this_frame
->level
< 0)
172 /* FIXME: cagney/2003-03-06: Old code and and a sentinel
173 frame. Do like was always done. Fetch the PC's value
174 direct from the global registers array (via read_pc).
175 This assumes that this frame belongs to the current
176 global register cache. The assumption is dangerous. */
179 else if (DEPRECATED_FRAME_SAVED_PC_P ())
181 /* FIXME: cagney/2003-03-06: Old code, but not a sentinel
182 frame. Do like was always done. Note that this method,
183 unlike unwind_pc(), tries to handle all the different
184 frame cases directly. It fails. */
185 pc
= DEPRECATED_FRAME_SAVED_PC (this_frame
);
188 internal_error (__FILE__
, __LINE__
, "No gdbarch_unwind_pc method");
189 this_frame
->pc_unwind_cache
= pc
;
190 this_frame
->pc_unwind_cache_p
= 1;
192 return this_frame
->pc_unwind_cache
;
196 do_frame_unwind_register (void *src
, int regnum
, void *buf
)
198 frame_unwind_register (src
, regnum
, buf
);
203 frame_pop (struct frame_info
*this_frame
)
205 struct regcache
*scratch_regcache
;
206 struct cleanup
*cleanups
;
208 if (DEPRECATED_POP_FRAME_P ())
210 /* A legacy architecture that has implemented a custom pop
211 function. All new architectures should instead be using the
212 generic code below. */
213 DEPRECATED_POP_FRAME
;
217 /* Make a copy of all the register values unwound from this
218 frame. Save them in a scratch buffer so that there isn't a
219 race betweening trying to extract the old values from the
220 current_regcache while, at the same time writing new values
221 into that same cache. */
222 struct regcache
*scratch
= regcache_xmalloc (current_gdbarch
);
223 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (scratch
);
224 regcache_save (scratch
, do_frame_unwind_register
, this_frame
);
225 /* FIXME: cagney/2003-03-16: It should be possible to tell the
226 target's register cache that it is about to be hit with a
227 burst register transfer and that the sequence of register
228 writes should be batched. The pair target_prepare_to_store()
229 and target_store_registers() kind of suggest this
230 functionality. Unfortunatly, they don't implement it. Their
231 lack of a formal definition can lead to targets writing back
232 bogus values (arguably a bug in the target code mind). */
233 /* Now copy those saved registers into the current regcache.
234 Here, regcache_cpy() calls regcache_restore(). */
235 regcache_cpy (current_regcache
, scratch
);
236 do_cleanups (cleanups
);
238 /* We've made right mess of GDB's local state, just discard
240 flush_cached_frames ();
244 frame_register_unwind (struct frame_info
*frame
, int regnum
,
245 int *optimizedp
, enum lval_type
*lvalp
,
246 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
248 struct frame_unwind_cache
*cache
;
250 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
251 that the value proper does not need to be fetched. */
252 gdb_assert (optimizedp
!= NULL
);
253 gdb_assert (lvalp
!= NULL
);
254 gdb_assert (addrp
!= NULL
);
255 gdb_assert (realnump
!= NULL
);
256 /* gdb_assert (bufferp != NULL); */
258 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
259 is broken. There is always a frame. If there, for some reason,
260 isn't, there is some pretty busted code as it should have
261 detected the problem before calling here. */
262 gdb_assert (frame
!= NULL
);
264 /* Ask this frame to unwind its register. See comment in
265 "frame-unwind.h" for why NEXT frame and this unwind cace are
267 frame
->unwind
->prev_register (frame
->next
, &frame
->prologue_cache
, regnum
,
268 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
273 frame_register (struct frame_info
*frame
, int regnum
,
274 int *optimizedp
, enum lval_type
*lvalp
,
275 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
277 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
278 that the value proper does not need to be fetched. */
279 gdb_assert (optimizedp
!= NULL
);
280 gdb_assert (lvalp
!= NULL
);
281 gdb_assert (addrp
!= NULL
);
282 gdb_assert (realnump
!= NULL
);
283 /* gdb_assert (bufferp != NULL); */
285 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
286 of the register in the register cache. It should instead return
287 the REGNUM corresponding to that register. Translate the . */
288 if (DEPRECATED_GET_SAVED_REGISTER_P ())
290 DEPRECATED_GET_SAVED_REGISTER (bufferp
, optimizedp
, addrp
, frame
,
292 /* Compute the REALNUM if the caller wants it. */
293 if (*lvalp
== lval_register
)
296 for (regnum
= 0; regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
; regnum
++)
298 if (*addrp
== register_offset_hack (current_gdbarch
, regnum
))
304 internal_error (__FILE__
, __LINE__
,
305 "Failed to compute the register number corresponding"
306 " to 0x%s", paddr_d (*addrp
));
312 /* Obtain the register value by unwinding the register from the next
313 (more inner frame). */
314 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
315 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
320 frame_unwind_register (struct frame_info
*frame
, int regnum
, void *buf
)
326 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
331 frame_unwind_signed_register (struct frame_info
*frame
, int regnum
,
334 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
335 frame_unwind_register (frame
, regnum
, buf
);
336 (*val
) = extract_signed_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
340 frame_unwind_unsigned_register (struct frame_info
*frame
, int regnum
,
343 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
344 frame_unwind_register (frame
, regnum
, buf
);
345 (*val
) = extract_unsigned_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
349 frame_read_register (struct frame_info
*frame
, int regnum
, void *buf
)
351 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
352 frame_unwind_register (frame
->next
, regnum
, buf
);
356 frame_read_unsigned_register (struct frame_info
*frame
, int regnum
,
359 /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is
360 always a frame. Both this, and the equivalent
361 frame_read_signed_register() function, can only be called with a
362 valid frame. If, for some reason, this function is called
363 without a frame then the problem isn't here, but rather in the
364 caller. It should of first created a frame and then passed that
366 /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the
367 ``current_frame'' should not be treated as a special case. While
368 ``get_next_frame (current_frame) == NULL'' currently holds, it
369 should, as far as possible, not be relied upon. In the future,
370 ``get_next_frame (current_frame)'' may instead simply return a
371 normal frame object that simply always gets register values from
372 the register cache. Consequently, frame code should try to avoid
373 tests like ``if get_next_frame() == NULL'' and instead just rely
374 on recursive frame calls (like the below code) when manipulating
376 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
377 frame_unwind_unsigned_register (frame
->next
, regnum
, val
);
381 frame_read_signed_register (struct frame_info
*frame
, int regnum
,
384 /* See note above in frame_read_unsigned_register(). */
385 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
386 frame_unwind_signed_register (frame
->next
, regnum
, val
);
390 generic_unwind_get_saved_register (char *raw_buffer
,
393 struct frame_info
*frame
,
395 enum lval_type
*lvalp
)
400 enum lval_type lvalx
;
402 if (!target_has_registers
)
403 error ("No registers.");
405 /* Keep things simple, ensure that all the pointers (except valuep)
407 if (optimizedp
== NULL
)
408 optimizedp
= &optimizedx
;
414 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
415 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
416 &realnumx
, raw_buffer
);
419 /* frame_register_read ()
421 Find and return the value of REGNUM for the specified stack frame.
422 The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
424 Returns 0 if the register value could not be found. */
427 frame_register_read (struct frame_info
*frame
, int regnum
, void *myaddr
)
433 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
435 /* FIXME: cagney/2002-05-15: This test, is just bogus.
437 It indicates that the target failed to supply a value for a
438 register because it was "not available" at this time. Problem
439 is, the target still has the register and so get saved_register()
440 may be returning a value saved on the stack. */
442 if (register_cached (regnum
) < 0)
443 return 0; /* register value not available */
449 /* Map between a frame register number and its name. A frame register
450 space is a superset of the cooked register space --- it also
451 includes builtin registers. */
454 frame_map_name_to_regnum (const char *name
, int len
)
461 /* Search register name space. */
462 for (i
= 0; i
< NUM_REGS
+ NUM_PSEUDO_REGS
; i
++)
463 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
464 && strncmp (name
, REGISTER_NAME (i
), len
) == 0)
469 /* Try builtin registers. */
470 i
= builtin_reg_map_name_to_regnum (name
, len
);
473 /* A builtin register doesn't fall into the architecture's
475 gdb_assert (i
>= NUM_REGS
+ NUM_PSEUDO_REGS
);
483 frame_map_regnum_to_name (int regnum
)
487 if (regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
)
488 return REGISTER_NAME (regnum
);
489 return builtin_reg_map_regnum_to_name (regnum
);
492 /* Create a sentinel frame. */
495 create_sentinel_frame (struct regcache
*regcache
)
497 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
498 frame
->type
= NORMAL_FRAME
;
500 /* Explicitly initialize the sentinel frame's cache. Provide it
501 with the underlying regcache. In the future additional
502 information, such as the frame's thread will be added. */
503 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
504 /* For the moment there is only one sentinel frame implementation. */
505 frame
->unwind
= sentinel_frame_unwind
;
506 /* Link this frame back to itself. The frame is self referential
507 (the unwound PC is the same as the pc), so make it so. */
509 /* Always unwind the PC as part of creating this frame. This
510 ensures that the frame's PC points at something valid. */
511 /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel
512 frame's PC may require information such as the frame's thread's
513 stop reason. Is it possible to get to that? */
514 frame
->pc
= frame_pc_unwind (frame
);
515 /* Make the sentinel frame's ID valid, but invalid. That way all
516 comparisons with it should fail. */
518 frame
->id
= null_frame_id
;
522 /* Info about the innermost stack frame (contents of FP register) */
524 static struct frame_info
*current_frame
;
526 /* Cache for frame addresses already read by gdb. Valid only while
527 inferior is stopped. Control variables for the frame cache should
528 be local to this module. */
530 static struct obstack frame_cache_obstack
;
533 frame_obstack_zalloc (unsigned long size
)
535 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
536 memset (data
, 0, size
);
541 frame_saved_regs_zalloc (struct frame_info
*fi
)
543 fi
->saved_regs
= (CORE_ADDR
*)
544 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
545 return fi
->saved_regs
;
549 get_frame_saved_regs (struct frame_info
*fi
)
551 return fi
->saved_regs
;
554 /* Return the innermost (currently executing) stack frame. This is
555 split into two functions. The function unwind_to_current_frame()
556 is wrapped in catch exceptions so that, even when the unwind of the
557 sentinel frame fails, the function still returns a stack frame. */
560 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
562 struct frame_info
*frame
= get_prev_frame (args
);
563 /* A sentinel frame can fail to unwind, eg, because it's PC value
564 lands in somewhere like start. */
567 current_frame
= frame
;
572 get_current_frame (void)
574 /* First check, and report, the lack of registers. Having GDB
575 report "No stack!" or "No memory" when the target doesn't even
576 have registers is very confusing. Besides, "printcmd.exp"
577 explicitly checks that ``print $pc'' with no registers prints "No
579 if (!target_has_registers
)
580 error ("No registers.");
581 if (!target_has_stack
)
583 if (!target_has_memory
)
584 error ("No memory.");
585 if (current_frame
== NULL
)
587 struct frame_info
*sentinel_frame
=
588 create_sentinel_frame (current_regcache
);
589 if (catch_exceptions (uiout
, unwind_to_current_frame
, sentinel_frame
,
590 NULL
, RETURN_MASK_ERROR
) != 0)
592 /* Oops! Fake a current frame? Is this useful? It has a PC
593 of zero, for instance. */
594 current_frame
= sentinel_frame
;
597 return current_frame
;
600 /* The "selected" stack frame is used by default for local and arg
601 access. May be zero, for no selected frame. */
603 struct frame_info
*deprecated_selected_frame
;
605 /* Return the selected frame. Always non-null (unless there isn't an
606 inferior sufficient for creating a frame) in which case an error is
610 get_selected_frame (void)
612 if (deprecated_selected_frame
== NULL
)
613 /* Hey! Don't trust this. It should really be re-finding the
614 last selected frame of the currently selected thread. This,
615 though, is better than nothing. */
616 select_frame (get_current_frame ());
617 /* There is always a frame. */
618 gdb_assert (deprecated_selected_frame
!= NULL
);
619 return deprecated_selected_frame
;
622 /* Select frame FI (or NULL - to invalidate the current frame). */
625 select_frame (struct frame_info
*fi
)
627 register struct symtab
*s
;
629 deprecated_selected_frame
= fi
;
630 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
631 frame is being invalidated. */
632 if (selected_frame_level_changed_hook
)
633 selected_frame_level_changed_hook (frame_relative_level (fi
));
635 /* FIXME: kseitz/2002-08-28: It would be nice to call
636 selected_frame_level_changed_event right here, but due to limitations
637 in the current interfaces, we would end up flooding UIs with events
638 because select_frame is used extensively internally.
640 Once we have frame-parameterized frame (and frame-related) commands,
641 the event notification can be moved here, since this function will only
642 be called when the users selected frame is being changed. */
644 /* Ensure that symbols for this frame are read in. Also, determine the
645 source language of this frame, and switch to it if desired. */
648 s
= find_pc_symtab (fi
->pc
);
650 && s
->language
!= current_language
->la_language
651 && s
->language
!= language_unknown
652 && language_mode
== language_mode_auto
)
654 set_language (s
->language
);
659 /* Return the register saved in the simplistic ``saved_regs'' cache.
660 If the value isn't here AND a value is needed, try the next inner
664 legacy_saved_regs_prev_register (struct frame_info
*next_frame
,
665 void **this_prologue_cache
,
666 int regnum
, int *optimizedp
,
667 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
668 int *realnump
, void *bufferp
)
670 /* HACK: New code is passed the next frame and this cache.
671 Unfortunatly, old code expects this frame. Since this is a
672 backward compatibility hack, cheat by walking one level along the
673 prologue chain to the frame the old code expects.
675 Do not try this at home. Professional driver, closed course. */
676 struct frame_info
*frame
= next_frame
->prev
;
677 gdb_assert (frame
!= NULL
);
679 /* Only (older) architectures that implement the
680 DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this
682 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
684 /* Load the saved_regs register cache. */
685 if (get_frame_saved_regs (frame
) == NULL
)
686 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
688 if (get_frame_saved_regs (frame
) != NULL
689 && get_frame_saved_regs (frame
)[regnum
] != 0)
691 if (regnum
== SP_REGNUM
)
693 /* SP register treated specially. */
699 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
700 get_frame_saved_regs (frame
)[regnum
]);
704 /* Any other register is saved in memory, fetch it but cache
705 a local copy of its value. */
707 *lvalp
= lval_memory
;
708 *addrp
= get_frame_saved_regs (frame
)[regnum
];
713 /* Save each register value, as it is read in, in a
714 frame based cache. */
715 void **regs
= (*this_prologue_cache
);
718 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
720 regs
= frame_obstack_zalloc (sizeof_cache
);
721 (*this_prologue_cache
) = regs
;
723 if (regs
[regnum
] == NULL
)
726 = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum
));
727 read_memory (get_frame_saved_regs (frame
)[regnum
], regs
[regnum
],
728 REGISTER_RAW_SIZE (regnum
));
730 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
732 /* Read the value in from memory. */
733 read_memory (get_frame_saved_regs (frame
)[regnum
], bufferp
,
734 REGISTER_RAW_SIZE (regnum
));
741 /* No luck. Assume this and the next frame have the same register
742 value. Pass the unwind request down the frame chain to the next
743 frame. Hopefully that frame will find the register's location. */
744 frame_register_unwind (next_frame
, regnum
, optimizedp
, lvalp
, addrp
,
749 legacy_saved_regs_this_id (struct frame_info
*next_frame
,
750 void **this_prologue_cache
,
757 if (frame_relative_level (next_frame
) < 0)
759 /* FIXME: cagney/2003-03-14: We've got the extra special case of
760 unwinding a sentinel frame, the PC of which is pointing at a
761 stack dummy. Fake up the dummy frame's ID using the same
762 sequence as is found a traditional unwinder. */
763 (*id
).base
= read_fp ();
764 (*id
).pc
= read_pc ();
768 /* Start out by assuming it's NULL. */
769 (*id
) = null_frame_id
;
771 if (frame_relative_level (next_frame
) <= 0)
772 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
773 the frame chain, not just the inner most frame! The generic,
774 per-architecture, frame code should handle this and the below
775 should simply be removed. */
776 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
781 /* A frameless inner-most frame. The `FP' (which isn't an
782 architecture frame-pointer register!) of the caller is the same
784 /* FIXME: 2002-11-09: There isn't any reason to special case this
785 edge condition. Instead the per-architecture code should hande
787 base
= get_frame_base (next_frame
);
790 /* Two macros defined in tm.h specify the machine-dependent
791 actions to be performed here.
793 First, get the frame's chain-pointer.
795 If that is zero, the frame is the outermost frame or a leaf
796 called by the outermost frame. This means that if start
797 calls main without a frame, we'll return 0 (which is fine
800 Nope; there's a problem. This also returns when the current
801 routine is a leaf of main. This is unacceptable. We move
802 this to after the ffi test; I'd rather have backtraces from
803 start go curfluy than have an abort called from main not show
805 gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
806 base
= DEPRECATED_FRAME_CHAIN (next_frame
);
808 if (!frame_chain_valid (base
, next_frame
))
814 /* FIXME: cagney/2002-06-08: This should probably return the frame's
815 function and not the PC (a.k.a. resume address). */
816 pc
= frame_pc_unwind (next_frame
);
821 const struct frame_unwind legacy_saved_regs_unwinder
= {
822 legacy_saved_regs_this_id
,
823 legacy_saved_regs_prev_register
825 const struct frame_unwind
*legacy_saved_regs_unwind
= &legacy_saved_regs_unwinder
;
828 /* Function: deprecated_generic_get_saved_register
829 Find register number REGNUM relative to FRAME and put its (raw,
830 target format) contents in *RAW_BUFFER.
832 Set *OPTIMIZED if the variable was optimized out (and thus can't be
833 fetched). Note that this is never set to anything other than zero
834 in this implementation.
836 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
837 whether the value was fetched from memory, from a register, or in a
838 strange and non-modifiable way (e.g. a frame pointer which was
839 calculated rather than fetched). We will use not_lval for values
840 fetched from generic dummy frames.
842 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
843 offset into the registers array. If the value is stored in a dummy
844 frame, set *ADDRP to zero.
846 The argument RAW_BUFFER must point to aligned memory. */
849 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
851 struct frame_info
*frame
, int regnum
,
852 enum lval_type
*lval
)
854 if (!target_has_registers
)
855 error ("No registers.");
857 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
859 /* Normal systems don't optimize out things with register numbers. */
860 if (optimized
!= NULL
)
863 if (addrp
) /* default assumption: not found in memory */
866 /* Note: since the current frame's registers could only have been
867 saved by frames INTERIOR TO the current frame, we skip examining
868 the current frame itself: otherwise, we would be getting the
869 previous frame's registers which were saved by the current frame. */
873 for (frame
= get_next_frame (frame
);
874 frame_relative_level (frame
) >= 0;
875 frame
= get_next_frame (frame
))
877 if (get_frame_type (frame
) == DUMMY_FRAME
)
879 if (lval
) /* found it in a CALL_DUMMY frame */
882 /* FIXME: cagney/2002-06-26: This should be via the
883 gdbarch_register_read() method so that it, on the
884 fly, constructs either a raw or pseudo register
885 from the raw register cache. */
887 (generic_find_dummy_frame (get_frame_pc (frame
),
888 get_frame_base (frame
)),
893 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
894 if (get_frame_saved_regs (frame
) != NULL
895 && get_frame_saved_regs (frame
)[regnum
] != 0)
897 if (lval
) /* found it saved on the stack */
899 if (regnum
== SP_REGNUM
)
901 if (raw_buffer
) /* SP register treated specially */
902 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
903 get_frame_saved_regs (frame
)[regnum
]);
907 if (addrp
) /* any other register */
908 *addrp
= get_frame_saved_regs (frame
)[regnum
];
910 read_memory (get_frame_saved_regs (frame
)[regnum
], raw_buffer
,
911 REGISTER_RAW_SIZE (regnum
));
918 /* If we get thru the loop to this point, it means the register was
919 not saved in any frame. Return the actual live-register value. */
921 if (lval
) /* found it in a live register */
922 *lval
= lval_register
;
924 *addrp
= REGISTER_BYTE (regnum
);
926 deprecated_read_register_gen (regnum
, raw_buffer
);
929 /* Determine the frame's type based on its PC. */
931 static enum frame_type
932 frame_type_from_pc (CORE_ADDR pc
)
934 /* FIXME: cagney/2002-11-24: Can't yet directly call
935 pc_in_dummy_frame() as some architectures don't set
936 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
937 latter is implemented by simply calling pc_in_dummy_frame). */
938 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
939 && DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0))
944 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
945 if (PC_IN_SIGTRAMP (pc
, name
))
946 return SIGTRAMP_FRAME
;
952 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
953 Always returns a non-NULL value. */
956 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
958 struct frame_info
*fi
;
960 fi
= frame_obstack_zalloc (sizeof (struct frame_info
));
964 fi
->next
= create_sentinel_frame (current_regcache
);
965 fi
->type
= frame_type_from_pc (pc
);
967 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
968 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi
);
970 /* Select/initialize an unwind function. */
971 fi
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, fi
->pc
);
976 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
977 innermost frame). Be careful to not fall off the bottom of the
978 frame chain and onto the sentinel frame. */
981 get_next_frame (struct frame_info
*this_frame
)
983 if (this_frame
->level
> 0)
984 return this_frame
->next
;
989 /* Flush the entire frame cache. */
992 flush_cached_frames (void)
994 /* Since we can't really be sure what the first object allocated was */
995 obstack_free (&frame_cache_obstack
, 0);
996 obstack_init (&frame_cache_obstack
);
998 current_frame
= NULL
; /* Invalidate cache */
1000 annotate_frames_invalid ();
1003 /* Flush the frame cache, and start a new one if necessary. */
1006 reinit_frame_cache (void)
1008 flush_cached_frames ();
1010 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
1011 if (PIDGET (inferior_ptid
) != 0)
1013 select_frame (get_current_frame ());
1017 /* Create the previous frame using the deprecated methods
1018 INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
1020 static struct frame_info
*
1021 legacy_get_prev_frame (struct frame_info
*this_frame
)
1023 CORE_ADDR address
= 0;
1024 struct frame_info
*prev
;
1027 /* Allocate the new frame but do not wire it in to the frame chain.
1028 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1029 frame->next to pull some fancy tricks (of course such code is, by
1030 definition, recursive). Try to prevent it.
1032 There is no reason to worry about memory leaks, should the
1033 remainder of the function fail. The allocated memory will be
1034 quickly reclaimed when the frame cache is flushed, and the `we've
1035 been here before' check, in get_prev_frame will stop repeated
1036 memory allocation calls. */
1037 prev
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1038 prev
->level
= this_frame
->level
+ 1;
1040 /* NOTE: cagney/2002-11-18: Should have been correctly setting the
1041 frame's type here, before anything else, and not last, at the
1042 bottom of this function. The various
1043 DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
1044 DEPRECATED_INIT_FRAME_PC_FIRST and
1045 DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
1046 that handle the frame not being correctly set from the start.
1047 Unfortunatly those same work-arounds rely on the type defaulting
1048 to NORMAL_FRAME. Ulgh! The new frame code does not have this
1050 prev
->type
= NORMAL_FRAME
;
1052 /* A legacy frame's ID is always computed here. Mark it as valid. */
1055 /* Handle sentinel frame unwind as a special case. */
1056 if (this_frame
->level
< 0)
1058 /* Try to unwind the PC. If that doesn't work, assume we've reached
1059 the oldest frame and simply return. Is there a better sentinal
1060 value? The unwound PC value is then used to initialize the new
1061 previous frame's type.
1063 Note that the pc-unwind is intentionally performed before the
1064 frame chain. This is ok since, for old targets, both
1065 frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and
1066 DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
1067 have already been initialized (using
1068 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1071 By unwinding the PC first, it becomes possible to, in the case of
1072 a dummy frame, avoid also unwinding the frame ID. This is
1073 because (well ignoring the PPC) a dummy frame can be located
1074 using THIS_FRAME's frame ID. */
1076 prev
->pc
= frame_pc_unwind (this_frame
);
1079 /* The allocated PREV_FRAME will be reclaimed when the frame
1080 obstack is next purged. */
1082 fprintf_unfiltered (gdb_stdlog
,
1083 "Outermost frame - unwound PC zero\n");
1086 prev
->type
= frame_type_from_pc (prev
->pc
);
1088 /* Set the unwind functions based on that identified PC. */
1089 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1091 /* Find the prev's frame's ID. */
1092 if (prev
->type
== DUMMY_FRAME
1093 && gdbarch_unwind_dummy_id_p (current_gdbarch
))
1095 /* When unwinding a normal frame, the stack structure is
1096 determined by analyzing the frame's function's code (be
1097 it using brute force prologue analysis, or the dwarf2
1098 CFI). In the case of a dummy frame, that simply isn't
1099 possible. The The PC is either the program entry point,
1100 or some random address on the stack. Trying to use that
1101 PC to apply standard frame ID unwind techniques is just
1102 asking for trouble. */
1103 /* Assume call_function_by_hand(), via SAVE_DUMMY_FRAME_TOS,
1104 previously saved the dummy frame's ID. Things only work
1105 if the two return the same value. */
1106 gdb_assert (SAVE_DUMMY_FRAME_TOS_P ());
1107 /* Use an architecture specific method to extract the prev's
1108 dummy ID from the next frame. Note that this method uses
1109 frame_register_unwind to obtain the register values
1110 needed to determine the dummy frame's ID. */
1111 prev
->id
= gdbarch_unwind_dummy_id (current_gdbarch
, this_frame
);
1115 /* We're unwinding a sentinel frame, the PC of which is
1116 pointing at a stack dummy. Fake up the dummy frame's ID
1117 using the same sequence as is found a traditional
1118 unwinder. Once all architectures supply the
1119 unwind_dummy_id method, this code can go away. */
1120 prev
->id
.base
= read_fp ();
1121 prev
->id
.pc
= read_pc ();
1124 /* Check that the unwound ID is valid. */
1125 if (!frame_id_p (prev
->id
))
1128 fprintf_unfiltered (gdb_stdlog
,
1129 "Outermost legacy sentinel frame - unwound frame ID invalid\n");
1133 /* Check that the new frame isn't inner to (younger, below,
1134 next) the old frame. If that happens the frame unwind is
1136 /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
1137 that doesn't have a valid frame ID. Should instead set the
1138 sentinel frame's frame ID to a `sentinel'. Leave it until
1139 after the switch to storing the frame ID, instead of the
1140 frame base, in the frame object. */
1142 /* FIXME: cagney/2002-12-18: Instead of this hack, should only
1143 store the frame ID in PREV_FRAME. Unfortunatly, some
1144 architectures (HP/UX) still reply on EXTRA_FRAME_INFO and,
1145 hence, still poke at the "struct frame_info" object directly. */
1146 prev
->frame
= prev
->id
.base
;
1149 this_frame
->prev
= prev
;
1150 prev
->next
= this_frame
;
1152 /* FIXME: cagney/2002-01-19: This call will go away. Instead of
1153 initializing extra info, all frames will use the frame_cache
1154 (passed to the unwind functions) to store additional frame
1155 info. Unfortunatly legacy targets can't use
1156 legacy_get_prev_frame() to unwind the sentinel frame and,
1157 consequently, are forced to take this code path and rely on
1158 the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
1159 initialize the inner-most frame. */
1160 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1162 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev
);
1167 /* This code only works on normal frames. A sentinel frame, where
1168 the level is -1, should never reach this code. */
1169 gdb_assert (this_frame
->level
>= 0);
1171 /* On some machines it is possible to call a function without
1172 setting up a stack frame for it. On these machines, we
1173 define this macro to take two args; a frameinfo pointer
1174 identifying a frame and a variable to set or clear if it is
1175 or isn't leafless. */
1177 /* Still don't want to worry about this except on the innermost
1178 frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
1179 function invocation. */
1180 if (this_frame
->level
== 0)
1181 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
1182 the frame chain, not just the inner most frame! The generic,
1183 per-architecture, frame code should handle this and the below
1184 should simply be removed. */
1185 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (this_frame
);
1190 /* A frameless inner-most frame. The `FP' (which isn't an
1191 architecture frame-pointer register!) of the caller is the same
1193 /* FIXME: 2002-11-09: There isn't any reason to special case this
1194 edge condition. Instead the per-architecture code should hande
1196 address
= get_frame_base (this_frame
);
1199 /* Two macros defined in tm.h specify the machine-dependent
1200 actions to be performed here.
1202 First, get the frame's chain-pointer.
1204 If that is zero, the frame is the outermost frame or a leaf
1205 called by the outermost frame. This means that if start
1206 calls main without a frame, we'll return 0 (which is fine
1209 Nope; there's a problem. This also returns when the current
1210 routine is a leaf of main. This is unacceptable. We move
1211 this to after the ffi test; I'd rather have backtraces from
1212 start go curfluy than have an abort called from main not show
1214 gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
1215 address
= DEPRECATED_FRAME_CHAIN (this_frame
);
1217 if (!frame_chain_valid (address
, this_frame
))
1223 /* Link in the already allocated prev frame. */
1224 this_frame
->prev
= prev
;
1225 prev
->next
= this_frame
;
1226 prev
->frame
= address
;
1228 /* This change should not be needed, FIXME! We should determine
1229 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1230 after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
1231 way to express what goes on here.
1233 DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
1234 create_new_frame (where the PC is already set up) and here (where
1235 it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
1236 always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
1238 The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
1239 requires the PC value (which hasn't been set yet). Some other
1240 machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
1241 before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
1243 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1244 complication to an already overcomplicated part of GDB.
1245 gnu@cygnus.com, 15Sep92.
1247 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1248 DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
1250 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1251 (read_fp ()), read_pc ()). Machines with extra frame info would
1252 do that (or the local equivalent) and then set the extra fields.
1254 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1255 create_new_frame would no longer init extra frame info;
1256 SETUP_ARBITRARY_FRAME would have to do that.
1258 INIT_PREV_FRAME(fromleaf, prev) Replace
1259 DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
1260 This should also return a flag saying whether to keep the new
1261 frame, or whether to discard it, because on some machines (e.g.
1262 mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
1263 called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
1264 way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
1265 into the extra fields of the new frame). std_frame_pc(fromleaf,
1268 This is the default setting for INIT_PREV_FRAME. It just does
1269 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1270 will call it from INIT_PREV_FRAME (either at the beginning, the
1271 end, or in the middle). Some machines won't use it.
1273 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1275 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1276 reason for things to be this complicated.
1278 The trick is to assume that there is always a frame. Instead of
1279 special casing the inner-most frame, create fake frame
1280 (containing the hardware registers) that is inner to the
1281 user-visible inner-most frame (...) and then unwind from that.
1282 That way architecture code can use use the standard
1283 frame_XX_unwind() functions and not differentiate between the
1284 inner most and any other case.
1286 Since there is always a frame to unwind from, there is always
1287 somewhere (THIS_FRAME) to store all the info needed to construct
1288 a new (previous) frame without having to first create it. This
1289 means that the convolution below - needing to carefully order a
1290 frame's initialization - isn't needed.
1292 The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
1293 for a more up-to-date architecture, always calls
1294 FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
1295 without first needing the frame! Instead of the convolution
1296 below, we could have simply called FRAME_SAVED_PC() and been done
1297 with it! Note that FRAME_SAVED_PC() is being superseed by
1298 frame_pc_unwind() and that function does have somewhere to cache
1301 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1302 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1304 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1305 DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1307 /* This entry is in the frame queue now, which is good since
1308 FRAME_SAVED_PC may use that queue to figure out its value (see
1309 tm-sparc.h). We want the pc saved in the inferior frame. */
1310 if (DEPRECATED_INIT_FRAME_PC_P ())
1311 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1313 /* If ->frame and ->pc are unchanged, we are in the process of
1314 getting ourselves into an infinite backtrace. Some architectures
1315 check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
1316 like there is no reason this can't be an architecture-independent
1318 if (prev
->frame
== this_frame
->frame
1319 && prev
->pc
== this_frame
->pc
)
1321 this_frame
->prev
= NULL
;
1322 obstack_free (&frame_cache_obstack
, prev
);
1326 /* Initialize the code used to unwind the frame PREV based on the PC
1327 (and probably other architectural information). The PC lets you
1328 check things like the debug info at that point (dwarf2cfi?) and
1329 use that to decide how the frame should be unwound. */
1330 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1332 /* NOTE: cagney/2002-11-18: The code segments, found in
1333 create_new_frame and get_prev_frame(), that initializes the
1334 frames type is subtly different. The latter only updates ->type
1335 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1336 get_prev_frame() overriding the frame's type when the INIT code
1337 has previously set it. This is really somewhat bogus. The
1338 initialization, as seen in create_new_frame(), should occur
1339 before the INIT function has been called. */
1340 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1341 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1342 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1343 : pc_in_dummy_frame (prev
->pc
)))
1344 prev
->type
= DUMMY_FRAME
;
1347 /* FIXME: cagney/2002-11-10: This should be moved to before the
1348 INIT code above so that the INIT code knows what the frame's
1349 type is (in fact, for a [generic] dummy-frame, the type can
1350 be set and then the entire initialization can be skipped.
1351 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1354 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1355 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1356 prev
->type
= SIGTRAMP_FRAME
;
1357 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1358 architectures are forcing the frame's type in INIT so we
1359 don't want to override it here. Remember, NORMAL_FRAME == 0,
1360 so it all works (just :-/). Once this initialization is
1361 moved to the start of this function, all this nastness will
1368 /* Return a structure containing various interesting information
1369 about the frame that called THIS_FRAME. Returns NULL
1370 if there is no such frame. */
1373 get_prev_frame (struct frame_info
*this_frame
)
1375 struct frame_info
*prev_frame
;
1377 /* Return the inner-most frame, when the caller passes in NULL. */
1378 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1379 caller should have previously obtained a valid frame using
1380 get_selected_frame() and then called this code - only possibility
1381 I can think of is code behaving badly.
1383 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1384 block_innermost_frame(). It does the sequence: frame = NULL;
1385 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1386 it couldn't be written better, I don't know.
1388 NOTE: cagney/2003-01-11: I suspect what is happening is
1389 block_innermost_frame() is, when the target has no state
1390 (registers, memory, ...), still calling this function. The
1391 assumption being that this function will return NULL indicating
1392 that a frame isn't possible, rather than checking that the target
1393 has state and then calling get_current_frame() and
1394 get_prev_frame(). This is a guess mind. */
1395 if (this_frame
== NULL
)
1397 /* NOTE: cagney/2002-11-09: There was a code segment here that
1398 would error out when CURRENT_FRAME was NULL. The comment
1399 that went with it made the claim ...
1401 ``This screws value_of_variable, which just wants a nice
1402 clean NULL return from block_innermost_frame if there are no
1403 frames. I don't think I've ever seen this message happen
1404 otherwise. And returning NULL here is a perfectly legitimate
1407 Per the above, this code shouldn't even be called with a NULL
1409 return current_frame
;
1412 /* There is always a frame. If this assertion fails, suspect that
1413 something should be calling get_selected_frame() or
1414 get_current_frame(). */
1415 gdb_assert (this_frame
!= NULL
);
1417 if (this_frame
->level
>= 0
1418 && !backtrace_below_main
1419 && inside_main_func (get_frame_pc (this_frame
)))
1420 /* Don't unwind past main(), bug always unwind the sentinel frame.
1421 Note, this is done _before_ the frame has been marked as
1422 previously unwound. That way if the user later decides to
1423 allow unwinds past main(), that just happens. */
1426 fprintf_unfiltered (gdb_stdlog
,
1427 "Outermost frame - inside main func.\n");
1431 /* Only try to do the unwind once. */
1432 if (this_frame
->prev_p
)
1433 return this_frame
->prev
;
1434 this_frame
->prev_p
= 1;
1437 /* If we're inside the entry file, it isn't valid. Don't apply this
1438 test to a dummy frame - dummy frame PC's typically land in the
1439 entry file. Don't apply this test to the sentinel frame.
1440 Sentinel frames should always be allowed to unwind. */
1441 /* NOTE: drow/2002-12-25: should there be a way to disable this
1442 check? It assumes a single small entry file, and the way some
1443 debug readers (e.g. dbxread) figure out which object is the
1444 entry file is somewhat hokey. */
1445 /* NOTE: cagney/2003-01-10: If there is a way of disabling this test
1446 then it should probably be moved to before the ->prev_p test,
1448 /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call to
1449 inside_entry_file destroys a meaningful backtrace under some
1450 conditions. E. g. the backtrace tests in the asm-source testcase
1451 are broken for some targets. In this test the functions are all
1452 implemented as part of one file and the testcase is not necessarily
1453 linked with a start file (depending on the target). What happens is,
1454 that the first frame is printed normaly and following frames are
1455 treated as being inside the enttry file then. This way, only the
1456 #0 frame is printed in the backtrace output. */
1457 if (this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1458 && inside_entry_file (get_frame_pc (this_frame
)))
1461 fprintf_unfiltered (gdb_stdlog
,
1462 "Outermost frame - inside entry file\n");
1467 /* If we're already inside the entry function for the main objfile,
1468 then it isn't valid. Don't apply this test to a dummy frame -
1469 dummy frame PC's typically land in the entry func. Don't apply
1470 this test to the sentinel frame. Sentinel frames should always
1471 be allowed to unwind. */
1472 /* NOTE: cagney/2003-02-25: Don't enable until someone has found
1473 hard evidence that this is needed. */
1475 && this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1476 && inside_entry_func (get_frame_pc (this_frame
)))
1479 fprintf_unfiltered (gdb_stdlog
,
1480 "Outermost frame - inside entry func\n");
1484 /* If any of the old frame initialization methods are around, use
1485 the legacy get_prev_frame method. */
1486 if (legacy_frame_p (current_gdbarch
))
1488 prev_frame
= legacy_get_prev_frame (this_frame
);
1489 if (frame_debug
&& prev_frame
== NULL
)
1490 fprintf_unfiltered (gdb_stdlog
,
1491 "Outermost frame - legacy_get_prev_frame NULL.\n");
1495 /* Check that this frame's ID was valid. If it wasn't, don't try to
1496 unwind to the prev frame. Be careful to not apply this test to
1497 the sentinel frame. */
1498 if (this_frame
->level
>= 0 && !frame_id_p (get_frame_id (this_frame
)))
1501 fprintf_filtered (gdb_stdlog
,
1502 "Outermost frame - this ID is NULL\n");
1506 /* Check that this frame's ID isn't inner to (younger, below, next)
1507 the next frame. This happens when frame unwind goes backwards.
1508 Since the sentinel frame isn't valid, don't apply this if this
1509 frame is entier the inner-most or sentinel frame. */
1510 if (this_frame
->level
> 0
1511 && frame_id_inner (get_frame_id (this_frame
),
1512 get_frame_id (this_frame
->next
)))
1513 error ("This frame inner-to next frame (corrupt stack?)");
1515 /* Check that this and the next frame are different. If they are
1516 not, there is most likely a stack cycle. As with the inner-than
1517 test, avoid the inner-most and sentinel frames. */
1518 /* FIXME: cagney/2003-03-17: Can't yet enable this this check. The
1519 frame_id_eq() method doesn't yet use function addresses when
1520 comparing frame IDs. */
1522 && this_frame
->level
> 0
1523 && frame_id_eq (get_frame_id (this_frame
),
1524 get_frame_id (this_frame
->next
)))
1525 error ("This frame identical to next frame (corrupt stack?)");
1527 /* Allocate the new frame but do not wire it in to the frame chain.
1528 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1529 frame->next to pull some fancy tricks (of course such code is, by
1530 definition, recursive). Try to prevent it.
1532 There is no reason to worry about memory leaks, should the
1533 remainder of the function fail. The allocated memory will be
1534 quickly reclaimed when the frame cache is flushed, and the `we've
1535 been here before' check above will stop repeated memory
1536 allocation calls. */
1537 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1538 prev_frame
->level
= this_frame
->level
+ 1;
1540 /* Try to unwind the PC. If that doesn't work, assume we've reached
1541 the oldest frame and simply return. Is there a better sentinal
1542 value? The unwound PC value is then used to initialize the new
1543 previous frame's type.
1545 Note that the pc-unwind is intentionally performed before the
1546 frame chain. This is ok since, for old targets, both
1547 frame_pc_unwind (nee, FRAME_SAVED_PC) and
1548 DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
1549 have already been initialized (using
1550 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1553 By unwinding the PC first, it becomes possible to, in the case of
1554 a dummy frame, avoid also unwinding the frame ID. This is
1555 because (well ignoring the PPC) a dummy frame can be located
1556 using THIS_FRAME's frame ID. */
1558 prev_frame
->pc
= frame_pc_unwind (this_frame
);
1559 if (prev_frame
->pc
== 0)
1561 /* The allocated PREV_FRAME will be reclaimed when the frame
1562 obstack is next purged. */
1564 fprintf_unfiltered (gdb_stdlog
,
1565 "Outermost frame - unwound PC zero\n");
1568 prev_frame
->type
= frame_type_from_pc (prev_frame
->pc
);
1570 /* Set the unwind functions based on that identified PC. */
1571 prev_frame
->unwind
= frame_unwind_find_by_pc (current_gdbarch
,
1574 /* The prev's frame's ID is computed by demand in get_frame_id(). */
1576 /* The unwound frame ID is validate at the start of this function,
1577 as part of the logic to decide if that frame should be further
1578 unwound, and not here while the prev frame is being created.
1579 Doing this makes it possible for the user to examine a frame that
1580 has an invalid frame ID.
1582 The very old VAX frame_args_address_correct() method noted: [...]
1583 For the sake of argument, suppose that the stack is somewhat
1584 trashed (which is one reason that "info frame" exists). So,
1585 return 0 (indicating we don't know the address of the arglist) if
1586 we don't know what frame this frame calls. */
1589 this_frame
->prev
= prev_frame
;
1590 prev_frame
->next
= this_frame
;
1596 get_frame_pc (struct frame_info
*frame
)
1602 pc_notcurrent (struct frame_info
*frame
)
1604 /* If FRAME is not the innermost frame, that normally means that
1605 FRAME->pc points at the return instruction (which is *after* the
1606 call instruction), and we want to get the line containing the
1607 call (because the call is where the user thinks the program is).
1608 However, if the next frame is either a SIGTRAMP_FRAME or a
1609 DUMMY_FRAME, then the next frame will contain a saved interrupt
1610 PC and such a PC indicates the current (rather than next)
1611 instruction/line, consequently, for such cases, want to get the
1612 line containing fi->pc. */
1613 struct frame_info
*next
= get_next_frame (frame
);
1614 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1619 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1621 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1624 /* Per "frame.h", return the ``address'' of the frame. Code should
1625 really be using get_frame_id(). */
1627 get_frame_base (struct frame_info
*fi
)
1631 /* HACK: Force the ID code to (indirectly) initialize the
1638 /* High-level offsets into the frame. Used by the debug info. */
1641 get_frame_base_address (struct frame_info
*fi
)
1643 if (fi
->type
!= NORMAL_FRAME
)
1645 if (fi
->base
== NULL
)
1646 fi
->base
= frame_base_find_by_pc (current_gdbarch
, get_frame_pc (fi
));
1647 /* Sneaky: If the low-level unwind and high-level base code share a
1648 common unwinder, let them share the prologue cache. */
1649 if (fi
->base
->unwind
== fi
->unwind
)
1650 return fi
->base
->this_base (fi
->next
, &fi
->prologue_cache
);
1651 return fi
->base
->this_base (fi
->next
, &fi
->base_cache
);
1655 get_frame_locals_address (struct frame_info
*fi
)
1658 if (fi
->type
!= NORMAL_FRAME
)
1660 /* If there isn't a frame address method, find it. */
1661 if (fi
->base
== NULL
)
1662 fi
->base
= frame_base_find_by_pc (current_gdbarch
, get_frame_pc (fi
));
1663 /* Sneaky: If the low-level unwind and high-level base code share a
1664 common unwinder, let them share the prologue cache. */
1665 if (fi
->base
->unwind
== fi
->unwind
)
1666 cache
= &fi
->prologue_cache
;
1668 cache
= &fi
->base_cache
;
1669 return fi
->base
->this_locals (fi
->next
, cache
);
1673 get_frame_args_address (struct frame_info
*fi
)
1676 if (fi
->type
!= NORMAL_FRAME
)
1678 /* If there isn't a frame address method, find it. */
1679 if (fi
->base
== NULL
)
1680 fi
->base
= frame_base_find_by_pc (current_gdbarch
, get_frame_pc (fi
));
1681 /* Sneaky: If the low-level unwind and high-level base code share a
1682 common unwinder, let them share the prologue cache. */
1683 if (fi
->base
->unwind
== fi
->unwind
)
1684 cache
= &fi
->prologue_cache
;
1686 cache
= &fi
->base_cache
;
1687 return fi
->base
->this_args (fi
->next
, cache
);
1690 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1691 or -1 for a NULL frame. */
1694 frame_relative_level (struct frame_info
*fi
)
1703 get_frame_type (struct frame_info
*frame
)
1705 /* Some targets still don't use [generic] dummy frames. Catch them
1707 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1708 && deprecated_frame_in_dummy (frame
))
1714 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1716 /* Arrrg! See comment in "frame.h". */
1720 #ifdef FRAME_FIND_SAVED_REGS
1721 /* XXX - deprecated. This is a compatibility function for targets
1722 that do not yet implement DEPRECATED_FRAME_INIT_SAVED_REGS. */
1723 /* Find the addresses in which registers are saved in FRAME. */
1726 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1727 struct frame_saved_regs
*saved_regs_addr
)
1729 if (frame
->saved_regs
== NULL
)
1731 frame
->saved_regs
= (CORE_ADDR
*)
1732 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
1734 if (saved_regs_addr
== NULL
)
1736 struct frame_saved_regs saved_regs
;
1737 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1738 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1742 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1743 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1748 struct frame_extra_info
*
1749 get_frame_extra_info (struct frame_info
*fi
)
1751 return fi
->extra_info
;
1754 struct frame_extra_info
*
1755 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1757 fi
->extra_info
= frame_obstack_zalloc (size
);
1758 return fi
->extra_info
;
1762 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
1764 /* See comment in "frame.h". */
1766 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
1767 maintaining a locally allocated frame object. Since such frame's
1768 are not in the frame chain, it isn't possible to assume that the
1769 frame has a next. Sigh. */
1770 if (frame
->next
!= NULL
)
1772 /* While we're at it, update this frame's cached PC value, found
1773 in the next frame. Oh for the day when "struct frame_info"
1774 is opaque and this hack on hack can just go away. */
1775 frame
->next
->pc_unwind_cache
= pc
;
1776 frame
->next
->pc_unwind_cache_p
= 1;
1781 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
1783 /* See comment in "frame.h". */
1784 frame
->frame
= base
;
1788 deprecated_set_frame_saved_regs_hack (struct frame_info
*frame
,
1789 CORE_ADDR
*saved_regs
)
1791 frame
->saved_regs
= saved_regs
;
1795 deprecated_set_frame_extra_info_hack (struct frame_info
*frame
,
1796 struct frame_extra_info
*extra_info
)
1798 frame
->extra_info
= extra_info
;
1802 deprecated_set_frame_next_hack (struct frame_info
*fi
,
1803 struct frame_info
*next
)
1809 deprecated_set_frame_prev_hack (struct frame_info
*fi
,
1810 struct frame_info
*prev
)
1816 deprecated_get_frame_context (struct frame_info
*fi
)
1822 deprecated_set_frame_context (struct frame_info
*fi
,
1823 struct context
*context
)
1825 fi
->context
= context
;
1829 deprecated_frame_xmalloc (void)
1831 struct frame_info
*frame
= XMALLOC (struct frame_info
);
1832 memset (frame
, 0, sizeof (struct frame_info
));
1837 deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs
,
1838 long sizeof_extra_info
)
1840 struct frame_info
*frame
= deprecated_frame_xmalloc ();
1841 make_cleanup (xfree
, frame
);
1842 if (sizeof_saved_regs
> 0)
1844 frame
->saved_regs
= xcalloc (1, sizeof_saved_regs
);
1845 make_cleanup (xfree
, frame
->saved_regs
);
1847 if (sizeof_extra_info
> 0)
1849 frame
->extra_info
= xcalloc (1, sizeof_extra_info
);
1850 make_cleanup (xfree
, frame
->extra_info
);
1856 legacy_frame_p (struct gdbarch
*current_gdbarch
)
1858 return (DEPRECATED_INIT_FRAME_PC_P ()
1859 || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
1860 || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
1861 || DEPRECATED_FRAME_CHAIN_P ()
1862 || !gdbarch_unwind_dummy_id_p (current_gdbarch
)
1863 || !SAVE_DUMMY_FRAME_TOS_P ());
1867 _initialize_frame (void)
1869 obstack_init (&frame_cache_obstack
);
1871 /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest
1872 `set backtrace {past,beyond,...}-main'. Also suggest adding `set
1873 backtrace ...-start' to control backtraces past start. The
1874 problem with `below' is that it stops the `up' command. */
1876 add_setshow_boolean_cmd ("backtrace-below-main", class_obscure
,
1877 &backtrace_below_main
, "\
1878 Set whether backtraces should continue past \"main\".\n\
1879 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1880 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1881 of the stack trace.", "\
1882 Show whether backtraces should continue past \"main\".\n\
1883 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1884 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1885 of the stack trace.",
1886 NULL
, NULL
, &setlist
, &showlist
);
1889 /* Debug this files internals. */
1890 add_show_from_set (add_set_cmd ("frame", class_maintenance
, var_zinteger
,
1891 &frame_debug
, "Set frame debugging.\n\
1892 When non-zero, frame specific internal debugging is enabled.", &setdebuglist
),