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"
42 /* Flag to control debugging. */
44 static int frame_debug
;
46 /* Flag to indicate whether backtraces should stop at main. */
48 static int backtrace_below_main
;
50 /* Return a frame uniq ID that can be used to, later, re-find the
54 get_frame_id (struct frame_info
*fi
)
62 gdb_assert (!legacy_frame_p (current_gdbarch
));
63 /* Find THIS frame's ID. */
64 fi
->unwind
->this_id (fi
->next
, &fi
->prologue_cache
, &fi
->id
);
66 /* FIXME: cagney/2002-12-18: Instead of this hack, should only
67 store the frame ID in PREV_FRAME. Unfortunatly, some
68 architectures (HP/UX) still reply on EXTRA_FRAME_INFO and,
69 hence, still poke at the "struct frame_info" object directly. */
70 fi
->frame
= fi
->id
.base
;
72 return frame_id_build (fi
->frame
, fi
->pc
);
75 const struct frame_id null_frame_id
; /* All zeros. */
78 frame_id_build (CORE_ADDR base
, CORE_ADDR func_or_pc
)
87 frame_id_p (struct frame_id l
)
89 /* The .func can be NULL but the .base cannot. */
94 frame_id_eq (struct frame_id l
, struct frame_id r
)
96 /* If .base is different, the frames are different. */
99 /* Add a test to check that the frame ID's are for the same function
105 frame_id_inner (struct frame_id l
, struct frame_id r
)
107 /* Only return non-zero when strictly inner than. Note that, per
108 comment in "frame.h", there is some fuzz here. Frameless
109 functions are not strictly inner than (same .base but different
111 return INNER_THAN (l
.base
, r
.base
);
115 frame_find_by_id (struct frame_id id
)
117 struct frame_info
*frame
;
119 /* ZERO denotes the null frame, let the caller decide what to do
120 about it. Should it instead return get_current_frame()? */
121 if (!frame_id_p (id
))
124 for (frame
= get_current_frame ();
126 frame
= get_prev_frame (frame
))
128 struct frame_id
this = get_frame_id (frame
);
129 if (frame_id_eq (id
, this))
130 /* An exact match. */
132 if (frame_id_inner (id
, this))
135 /* Either, we're not yet gone far enough out along the frame
136 chain (inner(this,id), or we're comparing frameless functions
137 (same .base, different .func, no test available). Struggle
138 on until we've definitly gone to far. */
144 frame_pc_unwind (struct frame_info
*this_frame
)
146 if (!this_frame
->pc_unwind_cache_p
)
149 if (gdbarch_unwind_pc_p (current_gdbarch
))
151 /* The right way. The `pure' way. The one true way. This
152 method depends solely on the register-unwind code to
153 determine the value of registers in THIS frame, and hence
154 the value of this frame's PC (resume address). A typical
155 implementation is no more than:
157 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
158 return extract_address (buf, size of ISA_PC_REGNUM);
160 Note: this method is very heavily dependent on a correct
161 register-unwind implementation, it pays to fix that
162 method first; this method is frame type agnostic, since
163 it only deals with register values, it works with any
164 frame. This is all in stark contrast to the old
165 FRAME_SAVED_PC which would try to directly handle all the
166 different ways that a PC could be unwound. */
167 pc
= gdbarch_unwind_pc (current_gdbarch
, this_frame
);
169 else if (this_frame
->level
< 0)
171 /* FIXME: cagney/2003-03-06: Old code and and a sentinel
172 frame. Do like was always done. Fetch the PC's value
173 direct from the global registers array (via read_pc).
174 This assumes that this frame belongs to the current
175 global register cache. The assumption is dangerous. */
178 else if (DEPRECATED_FRAME_SAVED_PC_P ())
180 /* FIXME: cagney/2003-03-06: Old code, but not a sentinel
181 frame. Do like was always done. Note that this method,
182 unlike unwind_pc(), tries to handle all the different
183 frame cases directly. It fails. */
184 pc
= DEPRECATED_FRAME_SAVED_PC (this_frame
);
187 internal_error (__FILE__
, __LINE__
, "No gdbarch_unwind_pc method");
188 this_frame
->pc_unwind_cache
= pc
;
189 this_frame
->pc_unwind_cache_p
= 1;
191 return this_frame
->pc_unwind_cache
;
195 do_frame_unwind_register (void *src
, int regnum
, void *buf
)
197 frame_unwind_register (src
, regnum
, buf
);
202 frame_pop (struct frame_info
*this_frame
)
204 struct regcache
*scratch_regcache
;
205 struct cleanup
*cleanups
;
207 if (DEPRECATED_POP_FRAME_P ())
209 /* A legacy architecture that has implemented a custom pop
210 function. All new architectures should instead be using the
211 generic code below. */
212 DEPRECATED_POP_FRAME
;
216 /* Make a copy of all the register values unwound from this
217 frame. Save them in a scratch buffer so that there isn't a
218 race betweening trying to extract the old values from the
219 current_regcache while, at the same time writing new values
220 into that same cache. */
221 struct regcache
*scratch
= regcache_xmalloc (current_gdbarch
);
222 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (scratch
);
223 regcache_save (scratch
, do_frame_unwind_register
, this_frame
);
224 /* FIXME: cagney/2003-03-16: It should be possible to tell the
225 target's register cache that it is about to be hit with a
226 burst register transfer and that the sequence of register
227 writes should be batched. The pair target_prepare_to_store()
228 and target_store_registers() kind of suggest this
229 functionality. Unfortunatly, they don't implement it. Their
230 lack of a formal definition can lead to targets writing back
231 bogus values (arguably a bug in the target code mind). */
232 /* Now copy those saved registers into the current regcache.
233 Here, regcache_cpy() calls regcache_restore(). */
234 regcache_cpy (current_regcache
, scratch
);
235 do_cleanups (cleanups
);
237 /* We've made right mess of GDB's local state, just discard
239 flush_cached_frames ();
243 frame_register_unwind (struct frame_info
*frame
, int regnum
,
244 int *optimizedp
, enum lval_type
*lvalp
,
245 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
247 struct frame_unwind_cache
*cache
;
249 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
250 that the value proper does not need to be fetched. */
251 gdb_assert (optimizedp
!= NULL
);
252 gdb_assert (lvalp
!= NULL
);
253 gdb_assert (addrp
!= NULL
);
254 gdb_assert (realnump
!= NULL
);
255 /* gdb_assert (bufferp != NULL); */
257 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
258 is broken. There is always a frame. If there, for some reason,
259 isn't, there is some pretty busted code as it should have
260 detected the problem before calling here. */
261 gdb_assert (frame
!= NULL
);
263 /* Ask this frame to unwind its register. See comment in
264 "frame-unwind.h" for why NEXT frame and this unwind cace are
266 frame
->unwind
->prev_register (frame
->next
, &frame
->prologue_cache
, regnum
,
267 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
272 frame_register (struct frame_info
*frame
, int regnum
,
273 int *optimizedp
, enum lval_type
*lvalp
,
274 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
276 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
277 that the value proper does not need to be fetched. */
278 gdb_assert (optimizedp
!= NULL
);
279 gdb_assert (lvalp
!= NULL
);
280 gdb_assert (addrp
!= NULL
);
281 gdb_assert (realnump
!= NULL
);
282 /* gdb_assert (bufferp != NULL); */
284 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
285 of the register in the register cache. It should instead return
286 the REGNUM corresponding to that register. Translate the . */
287 if (DEPRECATED_GET_SAVED_REGISTER_P ())
289 DEPRECATED_GET_SAVED_REGISTER (bufferp
, optimizedp
, addrp
, frame
,
291 /* Compute the REALNUM if the caller wants it. */
292 if (*lvalp
== lval_register
)
295 for (regnum
= 0; regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
; regnum
++)
297 if (*addrp
== register_offset_hack (current_gdbarch
, regnum
))
303 internal_error (__FILE__
, __LINE__
,
304 "Failed to compute the register number corresponding"
305 " to 0x%s", paddr_d (*addrp
));
311 /* Obtain the register value by unwinding the register from the next
312 (more inner frame). */
313 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
314 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
319 frame_unwind_register (struct frame_info
*frame
, int regnum
, void *buf
)
325 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
330 frame_unwind_signed_register (struct frame_info
*frame
, int regnum
,
333 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
334 frame_unwind_register (frame
, regnum
, buf
);
335 (*val
) = extract_signed_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
339 frame_unwind_unsigned_register (struct frame_info
*frame
, int regnum
,
342 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
343 frame_unwind_register (frame
, regnum
, buf
);
344 (*val
) = extract_unsigned_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
348 frame_read_register (struct frame_info
*frame
, int regnum
, void *buf
)
350 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
351 frame_unwind_register (frame
->next
, regnum
, buf
);
355 frame_read_unsigned_register (struct frame_info
*frame
, int regnum
,
358 /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is
359 always a frame. Both this, and the equivalent
360 frame_read_signed_register() function, can only be called with a
361 valid frame. If, for some reason, this function is called
362 without a frame then the problem isn't here, but rather in the
363 caller. It should of first created a frame and then passed that
365 /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the
366 ``current_frame'' should not be treated as a special case. While
367 ``get_next_frame (current_frame) == NULL'' currently holds, it
368 should, as far as possible, not be relied upon. In the future,
369 ``get_next_frame (current_frame)'' may instead simply return a
370 normal frame object that simply always gets register values from
371 the register cache. Consequently, frame code should try to avoid
372 tests like ``if get_next_frame() == NULL'' and instead just rely
373 on recursive frame calls (like the below code) when manipulating
375 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
376 frame_unwind_unsigned_register (frame
->next
, regnum
, val
);
380 frame_read_signed_register (struct frame_info
*frame
, int regnum
,
383 /* See note above in frame_read_unsigned_register(). */
384 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
385 frame_unwind_signed_register (frame
->next
, regnum
, val
);
389 generic_unwind_get_saved_register (char *raw_buffer
,
392 struct frame_info
*frame
,
394 enum lval_type
*lvalp
)
399 enum lval_type lvalx
;
401 if (!target_has_registers
)
402 error ("No registers.");
404 /* Keep things simple, ensure that all the pointers (except valuep)
406 if (optimizedp
== NULL
)
407 optimizedp
= &optimizedx
;
413 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
414 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
415 &realnumx
, raw_buffer
);
418 /* frame_register_read ()
420 Find and return the value of REGNUM for the specified stack frame.
421 The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
423 Returns 0 if the register value could not be found. */
426 frame_register_read (struct frame_info
*frame
, int regnum
, void *myaddr
)
432 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
434 /* FIXME: cagney/2002-05-15: This test, is just bogus.
436 It indicates that the target failed to supply a value for a
437 register because it was "not available" at this time. Problem
438 is, the target still has the register and so get saved_register()
439 may be returning a value saved on the stack. */
441 if (register_cached (regnum
) < 0)
442 return 0; /* register value not available */
448 /* Map between a frame register number and its name. A frame register
449 space is a superset of the cooked register space --- it also
450 includes builtin registers. */
453 frame_map_name_to_regnum (const char *name
, int len
)
460 /* Search register name space. */
461 for (i
= 0; i
< NUM_REGS
+ NUM_PSEUDO_REGS
; i
++)
462 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
463 && strncmp (name
, REGISTER_NAME (i
), len
) == 0)
468 /* Try builtin registers. */
469 i
= builtin_reg_map_name_to_regnum (name
, len
);
472 /* A builtin register doesn't fall into the architecture's
474 gdb_assert (i
>= NUM_REGS
+ NUM_PSEUDO_REGS
);
482 frame_map_regnum_to_name (int regnum
)
486 if (regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
)
487 return REGISTER_NAME (regnum
);
488 return builtin_reg_map_regnum_to_name (regnum
);
491 /* Create a sentinel frame. */
494 create_sentinel_frame (struct regcache
*regcache
)
496 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
497 frame
->type
= NORMAL_FRAME
;
499 /* Explicitly initialize the sentinel frame's cache. Provide it
500 with the underlying regcache. In the future additional
501 information, such as the frame's thread will be added. */
502 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
503 /* For the moment there is only one sentinel frame implementation. */
504 frame
->unwind
= sentinel_frame_unwind
;
505 /* Link this frame back to itself. The frame is self referential
506 (the unwound PC is the same as the pc), so make it so. */
508 /* Always unwind the PC as part of creating this frame. This
509 ensures that the frame's PC points at something valid. */
510 /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel
511 frame's PC may require information such as the frame's thread's
512 stop reason. Is it possible to get to that? */
513 frame
->pc
= frame_pc_unwind (frame
);
517 /* Info about the innermost stack frame (contents of FP register) */
519 static struct frame_info
*current_frame
;
521 /* Cache for frame addresses already read by gdb. Valid only while
522 inferior is stopped. Control variables for the frame cache should
523 be local to this module. */
525 static struct obstack frame_cache_obstack
;
528 frame_obstack_zalloc (unsigned long size
)
530 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
531 memset (data
, 0, size
);
536 frame_saved_regs_zalloc (struct frame_info
*fi
)
538 fi
->saved_regs
= (CORE_ADDR
*)
539 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
540 return fi
->saved_regs
;
544 get_frame_saved_regs (struct frame_info
*fi
)
546 return fi
->saved_regs
;
549 /* Return the innermost (currently executing) stack frame. This is
550 split into two functions. The function unwind_to_current_frame()
551 is wrapped in catch exceptions so that, even when the unwind of the
552 sentinel frame fails, the function still returns a stack frame. */
555 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
557 struct frame_info
*frame
= get_prev_frame (args
);
558 /* A sentinel frame can fail to unwind, eg, because it's PC value
559 lands in somewhere like start. */
562 current_frame
= frame
;
567 get_current_frame (void)
569 /* First check, and report, the lack of registers. Having GDB
570 report "No stack!" or "No memory" when the target doesn't even
571 have registers is very confusing. Besides, "printcmd.exp"
572 explicitly checks that ``print $pc'' with no registers prints "No
574 if (!target_has_registers
)
575 error ("No registers.");
576 if (!target_has_stack
)
578 if (!target_has_memory
)
579 error ("No memory.");
580 if (current_frame
== NULL
)
582 struct frame_info
*sentinel_frame
=
583 create_sentinel_frame (current_regcache
);
584 if (catch_exceptions (uiout
, unwind_to_current_frame
, sentinel_frame
,
585 NULL
, RETURN_MASK_ERROR
) != 0)
587 /* Oops! Fake a current frame? Is this useful? It has a PC
588 of zero, for instance. */
589 current_frame
= sentinel_frame
;
592 return current_frame
;
595 /* The "selected" stack frame is used by default for local and arg
596 access. May be zero, for no selected frame. */
598 struct frame_info
*deprecated_selected_frame
;
600 /* Return the selected frame. Always non-null (unless there isn't an
601 inferior sufficient for creating a frame) in which case an error is
605 get_selected_frame (void)
607 if (deprecated_selected_frame
== NULL
)
608 /* Hey! Don't trust this. It should really be re-finding the
609 last selected frame of the currently selected thread. This,
610 though, is better than nothing. */
611 select_frame (get_current_frame ());
612 /* There is always a frame. */
613 gdb_assert (deprecated_selected_frame
!= NULL
);
614 return deprecated_selected_frame
;
617 /* Select frame FI (or NULL - to invalidate the current frame). */
620 select_frame (struct frame_info
*fi
)
622 register struct symtab
*s
;
624 deprecated_selected_frame
= fi
;
625 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
626 frame is being invalidated. */
627 if (selected_frame_level_changed_hook
)
628 selected_frame_level_changed_hook (frame_relative_level (fi
));
630 /* FIXME: kseitz/2002-08-28: It would be nice to call
631 selected_frame_level_changed_event right here, but due to limitations
632 in the current interfaces, we would end up flooding UIs with events
633 because select_frame is used extensively internally.
635 Once we have frame-parameterized frame (and frame-related) commands,
636 the event notification can be moved here, since this function will only
637 be called when the users selected frame is being changed. */
639 /* Ensure that symbols for this frame are read in. Also, determine the
640 source language of this frame, and switch to it if desired. */
643 s
= find_pc_symtab (fi
->pc
);
645 && s
->language
!= current_language
->la_language
646 && s
->language
!= language_unknown
647 && language_mode
== language_mode_auto
)
649 set_language (s
->language
);
654 /* Return the register saved in the simplistic ``saved_regs'' cache.
655 If the value isn't here AND a value is needed, try the next inner
659 legacy_saved_regs_prev_register (struct frame_info
*next_frame
,
660 void **this_prologue_cache
,
661 int regnum
, int *optimizedp
,
662 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
663 int *realnump
, void *bufferp
)
665 /* HACK: New code is passed the next frame and this cache.
666 Unfortunatly, old code expects this frame. Since this is a
667 backward compatibility hack, cheat by walking one level along the
668 prologue chain to the frame the old code expects.
670 Do not try this at home. Professional driver, closed course. */
671 struct frame_info
*frame
= next_frame
->prev
;
672 gdb_assert (frame
!= NULL
);
674 /* Only (older) architectures that implement the
675 DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this
677 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
679 /* Load the saved_regs register cache. */
680 if (get_frame_saved_regs (frame
) == NULL
)
681 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
683 if (get_frame_saved_regs (frame
) != NULL
684 && get_frame_saved_regs (frame
)[regnum
] != 0)
686 if (regnum
== SP_REGNUM
)
688 /* SP register treated specially. */
694 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
695 get_frame_saved_regs (frame
)[regnum
]);
699 /* Any other register is saved in memory, fetch it but cache
700 a local copy of its value. */
702 *lvalp
= lval_memory
;
703 *addrp
= get_frame_saved_regs (frame
)[regnum
];
708 /* Save each register value, as it is read in, in a
709 frame based cache. */
710 void **regs
= (*this_prologue_cache
);
713 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
715 regs
= frame_obstack_zalloc (sizeof_cache
);
716 (*this_prologue_cache
) = regs
;
718 if (regs
[regnum
] == NULL
)
721 = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum
));
722 read_memory (get_frame_saved_regs (frame
)[regnum
], regs
[regnum
],
723 REGISTER_RAW_SIZE (regnum
));
725 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
727 /* Read the value in from memory. */
728 read_memory (get_frame_saved_regs (frame
)[regnum
], bufferp
,
729 REGISTER_RAW_SIZE (regnum
));
736 /* No luck. Assume this and the next frame have the same register
737 value. Pass the unwind request down the frame chain to the next
738 frame. Hopefully that frame will find the register's location. */
739 frame_register_unwind (next_frame
, regnum
, optimizedp
, lvalp
, addrp
,
744 legacy_saved_regs_this_id (struct frame_info
*next_frame
,
745 void **this_prologue_cache
,
752 if (frame_relative_level (next_frame
) < 0)
754 /* FIXME: cagney/2003-03-14: We've got the extra special case of
755 unwinding a sentinel frame, the PC of which is pointing at a
756 stack dummy. Fake up the dummy frame's ID using the same
757 sequence as is found a traditional unwinder. */
758 (*id
).base
= read_fp ();
759 (*id
).pc
= read_pc ();
763 /* Start out by assuming it's NULL. */
764 (*id
) = null_frame_id
;
766 if (frame_relative_level (next_frame
) <= 0)
767 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
768 the frame chain, not just the inner most frame! The generic,
769 per-architecture, frame code should handle this and the below
770 should simply be removed. */
771 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
776 /* A frameless inner-most frame. The `FP' (which isn't an
777 architecture frame-pointer register!) of the caller is the same
779 /* FIXME: 2002-11-09: There isn't any reason to special case this
780 edge condition. Instead the per-architecture code should hande
782 base
= get_frame_base (next_frame
);
785 /* Two macros defined in tm.h specify the machine-dependent
786 actions to be performed here.
788 First, get the frame's chain-pointer.
790 If that is zero, the frame is the outermost frame or a leaf
791 called by the outermost frame. This means that if start
792 calls main without a frame, we'll return 0 (which is fine
795 Nope; there's a problem. This also returns when the current
796 routine is a leaf of main. This is unacceptable. We move
797 this to after the ffi test; I'd rather have backtraces from
798 start go curfluy than have an abort called from main not show
800 gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
801 base
= DEPRECATED_FRAME_CHAIN (next_frame
);
803 if (!frame_chain_valid (base
, next_frame
))
809 /* FIXME: cagney/2002-06-08: This should probably return the frame's
810 function and not the PC (a.k.a. resume address). */
811 pc
= frame_pc_unwind (next_frame
);
816 const struct frame_unwind legacy_saved_regs_unwinder
= {
817 legacy_saved_regs_this_id
,
818 legacy_saved_regs_prev_register
820 const struct frame_unwind
*legacy_saved_regs_unwind
= &legacy_saved_regs_unwinder
;
823 /* Function: deprecated_generic_get_saved_register
824 Find register number REGNUM relative to FRAME and put its (raw,
825 target format) contents in *RAW_BUFFER.
827 Set *OPTIMIZED if the variable was optimized out (and thus can't be
828 fetched). Note that this is never set to anything other than zero
829 in this implementation.
831 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
832 whether the value was fetched from memory, from a register, or in a
833 strange and non-modifiable way (e.g. a frame pointer which was
834 calculated rather than fetched). We will use not_lval for values
835 fetched from generic dummy frames.
837 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
838 offset into the registers array. If the value is stored in a dummy
839 frame, set *ADDRP to zero.
841 The argument RAW_BUFFER must point to aligned memory. */
844 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
846 struct frame_info
*frame
, int regnum
,
847 enum lval_type
*lval
)
849 if (!target_has_registers
)
850 error ("No registers.");
852 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
854 /* Normal systems don't optimize out things with register numbers. */
855 if (optimized
!= NULL
)
858 if (addrp
) /* default assumption: not found in memory */
861 /* Note: since the current frame's registers could only have been
862 saved by frames INTERIOR TO the current frame, we skip examining
863 the current frame itself: otherwise, we would be getting the
864 previous frame's registers which were saved by the current frame. */
868 for (frame
= get_next_frame (frame
);
869 frame_relative_level (frame
) >= 0;
870 frame
= get_next_frame (frame
))
872 if (get_frame_type (frame
) == DUMMY_FRAME
)
874 if (lval
) /* found it in a CALL_DUMMY frame */
877 /* FIXME: cagney/2002-06-26: This should be via the
878 gdbarch_register_read() method so that it, on the
879 fly, constructs either a raw or pseudo register
880 from the raw register cache. */
882 (generic_find_dummy_frame (get_frame_pc (frame
),
883 get_frame_base (frame
)),
888 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
889 if (get_frame_saved_regs (frame
) != NULL
890 && get_frame_saved_regs (frame
)[regnum
] != 0)
892 if (lval
) /* found it saved on the stack */
894 if (regnum
== SP_REGNUM
)
896 if (raw_buffer
) /* SP register treated specially */
897 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
898 get_frame_saved_regs (frame
)[regnum
]);
902 if (addrp
) /* any other register */
903 *addrp
= get_frame_saved_regs (frame
)[regnum
];
905 read_memory (get_frame_saved_regs (frame
)[regnum
], raw_buffer
,
906 REGISTER_RAW_SIZE (regnum
));
913 /* If we get thru the loop to this point, it means the register was
914 not saved in any frame. Return the actual live-register value. */
916 if (lval
) /* found it in a live register */
917 *lval
= lval_register
;
919 *addrp
= REGISTER_BYTE (regnum
);
921 deprecated_read_register_gen (regnum
, raw_buffer
);
924 /* Determine the frame's type based on its PC. */
926 static enum frame_type
927 frame_type_from_pc (CORE_ADDR pc
)
929 /* FIXME: cagney/2002-11-24: Can't yet directly call
930 pc_in_dummy_frame() as some architectures don't set
931 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
932 latter is implemented by simply calling pc_in_dummy_frame). */
933 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
934 && DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0))
939 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
940 if (PC_IN_SIGTRAMP (pc
, name
))
941 return SIGTRAMP_FRAME
;
947 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
948 Always returns a non-NULL value. */
951 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
953 struct frame_info
*fi
;
955 fi
= frame_obstack_zalloc (sizeof (struct frame_info
));
959 fi
->next
= create_sentinel_frame (current_regcache
);
960 fi
->type
= frame_type_from_pc (pc
);
962 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
963 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi
);
965 /* Select/initialize an unwind function. */
966 fi
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, fi
->pc
);
971 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
972 innermost frame). Be careful to not fall off the bottom of the
973 frame chain and onto the sentinel frame. */
976 get_next_frame (struct frame_info
*this_frame
)
978 if (this_frame
->level
> 0)
979 return this_frame
->next
;
984 /* Flush the entire frame cache. */
987 flush_cached_frames (void)
989 /* Since we can't really be sure what the first object allocated was */
990 obstack_free (&frame_cache_obstack
, 0);
991 obstack_init (&frame_cache_obstack
);
993 current_frame
= NULL
; /* Invalidate cache */
995 annotate_frames_invalid ();
998 /* Flush the frame cache, and start a new one if necessary. */
1001 reinit_frame_cache (void)
1003 flush_cached_frames ();
1005 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
1006 if (PIDGET (inferior_ptid
) != 0)
1008 select_frame (get_current_frame ());
1012 /* Create the previous frame using the deprecated methods
1013 INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
1015 static struct frame_info
*
1016 legacy_get_prev_frame (struct frame_info
*this_frame
)
1018 CORE_ADDR address
= 0;
1019 struct frame_info
*prev
;
1022 /* Allocate the new frame but do not wire it in to the frame chain.
1023 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1024 frame->next to pull some fancy tricks (of course such code is, by
1025 definition, recursive). Try to prevent it.
1027 There is no reason to worry about memory leaks, should the
1028 remainder of the function fail. The allocated memory will be
1029 quickly reclaimed when the frame cache is flushed, and the `we've
1030 been here before' check, in get_prev_frame will stop repeated
1031 memory allocation calls. */
1032 prev
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1033 prev
->level
= this_frame
->level
+ 1;
1035 /* NOTE: cagney/2002-11-18: Should have been correctly setting the
1036 frame's type here, before anything else, and not last, at the
1037 bottom of this function. The various
1038 DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
1039 DEPRECATED_INIT_FRAME_PC_FIRST and
1040 DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
1041 that handle the frame not being correctly set from the start.
1042 Unfortunatly those same work-arounds rely on the type defaulting
1043 to NORMAL_FRAME. Ulgh! The new frame code does not have this
1045 prev
->type
= NORMAL_FRAME
;
1047 /* A legacy frame's ID is always computed here. Mark it as valid. */
1050 /* Handle sentinel frame unwind as a special case. */
1051 if (this_frame
->level
< 0)
1053 /* Try to unwind the PC. If that doesn't work, assume we've reached
1054 the oldest frame and simply return. Is there a better sentinal
1055 value? The unwound PC value is then used to initialize the new
1056 previous frame's type.
1058 Note that the pc-unwind is intentionally performed before the
1059 frame chain. This is ok since, for old targets, both
1060 frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and
1061 DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
1062 have already been initialized (using
1063 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1066 By unwinding the PC first, it becomes possible to, in the case of
1067 a dummy frame, avoid also unwinding the frame ID. This is
1068 because (well ignoring the PPC) a dummy frame can be located
1069 using THIS_FRAME's frame ID. */
1071 prev
->pc
= frame_pc_unwind (this_frame
);
1074 /* The allocated PREV_FRAME will be reclaimed when the frame
1075 obstack is next purged. */
1077 fprintf_unfiltered (gdb_stdlog
,
1078 "Outermost frame - unwound PC zero\n");
1081 prev
->type
= frame_type_from_pc (prev
->pc
);
1083 /* Set the unwind functions based on that identified PC. */
1084 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1086 /* Find the prev's frame's ID. */
1087 if (prev
->type
== DUMMY_FRAME
1088 && gdbarch_unwind_dummy_id_p (current_gdbarch
))
1090 /* When unwinding a normal frame, the stack structure is
1091 determined by analyzing the frame's function's code (be
1092 it using brute force prologue analysis, or the dwarf2
1093 CFI). In the case of a dummy frame, that simply isn't
1094 possible. The The PC is either the program entry point,
1095 or some random address on the stack. Trying to use that
1096 PC to apply standard frame ID unwind techniques is just
1097 asking for trouble. */
1098 /* Assume hand_function_call(), via SAVE_DUMMY_FRAME_TOS,
1099 previously saved the dummy frame's ID. Things only work
1100 if the two return the same value. */
1101 gdb_assert (SAVE_DUMMY_FRAME_TOS_P ());
1102 /* Use an architecture specific method to extract the prev's
1103 dummy ID from the next frame. Note that this method uses
1104 frame_register_unwind to obtain the register values
1105 needed to determine the dummy frame's ID. */
1106 prev
->id
= gdbarch_unwind_dummy_id (current_gdbarch
, this_frame
);
1110 /* We're unwinding a sentinel frame, the PC of which is
1111 pointing at a stack dummy. Fake up the dummy frame's ID
1112 using the same sequence as is found a traditional
1113 unwinder. Once all architectures supply the
1114 unwind_dummy_id method, this code can go away. */
1115 prev
->id
.base
= read_fp ();
1116 prev
->id
.pc
= read_pc ();
1119 /* Check that the unwound ID is valid. */
1120 if (!frame_id_p (prev
->id
))
1123 fprintf_unfiltered (gdb_stdlog
,
1124 "Outermost legacy sentinel frame - unwound frame ID invalid\n");
1128 /* Check that the new frame isn't inner to (younger, below,
1129 next) the old frame. If that happens the frame unwind is
1131 /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
1132 that doesn't have a valid frame ID. Should instead set the
1133 sentinel frame's frame ID to a `sentinel'. Leave it until
1134 after the switch to storing the frame ID, instead of the
1135 frame base, in the frame object. */
1137 /* FIXME: cagney/2002-12-18: Instead of this hack, should only
1138 store the frame ID in PREV_FRAME. Unfortunatly, some
1139 architectures (HP/UX) still reply on EXTRA_FRAME_INFO and,
1140 hence, still poke at the "struct frame_info" object directly. */
1141 prev
->frame
= prev
->id
.base
;
1144 this_frame
->prev
= prev
;
1145 prev
->next
= this_frame
;
1147 /* FIXME: cagney/2002-01-19: This call will go away. Instead of
1148 initializing extra info, all frames will use the frame_cache
1149 (passed to the unwind functions) to store additional frame
1150 info. Unfortunatly legacy targets can't use
1151 legacy_get_prev_frame() to unwind the sentinel frame and,
1152 consequently, are forced to take this code path and rely on
1153 the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
1154 initialize the inner-most frame. */
1155 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1157 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev
);
1162 /* This code only works on normal frames. A sentinel frame, where
1163 the level is -1, should never reach this code. */
1164 gdb_assert (this_frame
->level
>= 0);
1166 /* On some machines it is possible to call a function without
1167 setting up a stack frame for it. On these machines, we
1168 define this macro to take two args; a frameinfo pointer
1169 identifying a frame and a variable to set or clear if it is
1170 or isn't leafless. */
1172 /* Still don't want to worry about this except on the innermost
1173 frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
1174 function invocation. */
1175 if (this_frame
->level
== 0)
1176 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
1177 the frame chain, not just the inner most frame! The generic,
1178 per-architecture, frame code should handle this and the below
1179 should simply be removed. */
1180 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (this_frame
);
1185 /* A frameless inner-most frame. The `FP' (which isn't an
1186 architecture frame-pointer register!) of the caller is the same
1188 /* FIXME: 2002-11-09: There isn't any reason to special case this
1189 edge condition. Instead the per-architecture code should hande
1191 address
= get_frame_base (this_frame
);
1194 /* Two macros defined in tm.h specify the machine-dependent
1195 actions to be performed here.
1197 First, get the frame's chain-pointer.
1199 If that is zero, the frame is the outermost frame or a leaf
1200 called by the outermost frame. This means that if start
1201 calls main without a frame, we'll return 0 (which is fine
1204 Nope; there's a problem. This also returns when the current
1205 routine is a leaf of main. This is unacceptable. We move
1206 this to after the ffi test; I'd rather have backtraces from
1207 start go curfluy than have an abort called from main not show
1209 gdb_assert (DEPRECATED_FRAME_CHAIN_P ());
1210 address
= DEPRECATED_FRAME_CHAIN (this_frame
);
1212 if (!frame_chain_valid (address
, this_frame
))
1218 /* Link in the already allocated prev frame. */
1219 this_frame
->prev
= prev
;
1220 prev
->next
= this_frame
;
1221 prev
->frame
= address
;
1223 /* This change should not be needed, FIXME! We should determine
1224 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1225 after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
1226 way to express what goes on here.
1228 DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
1229 create_new_frame (where the PC is already set up) and here (where
1230 it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
1231 always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
1233 The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
1234 requires the PC value (which hasn't been set yet). Some other
1235 machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
1236 before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
1238 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1239 complication to an already overcomplicated part of GDB.
1240 gnu@cygnus.com, 15Sep92.
1242 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1243 DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
1245 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1246 (read_fp ()), read_pc ()). Machines with extra frame info would
1247 do that (or the local equivalent) and then set the extra fields.
1249 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1250 create_new_frame would no longer init extra frame info;
1251 SETUP_ARBITRARY_FRAME would have to do that.
1253 INIT_PREV_FRAME(fromleaf, prev) Replace
1254 DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
1255 This should also return a flag saying whether to keep the new
1256 frame, or whether to discard it, because on some machines (e.g.
1257 mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
1258 called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
1259 way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
1260 into the extra fields of the new frame). std_frame_pc(fromleaf,
1263 This is the default setting for INIT_PREV_FRAME. It just does
1264 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1265 will call it from INIT_PREV_FRAME (either at the beginning, the
1266 end, or in the middle). Some machines won't use it.
1268 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1270 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1271 reason for things to be this complicated.
1273 The trick is to assume that there is always a frame. Instead of
1274 special casing the inner-most frame, create fake frame
1275 (containing the hardware registers) that is inner to the
1276 user-visible inner-most frame (...) and then unwind from that.
1277 That way architecture code can use use the standard
1278 frame_XX_unwind() functions and not differentiate between the
1279 inner most and any other case.
1281 Since there is always a frame to unwind from, there is always
1282 somewhere (THIS_FRAME) to store all the info needed to construct
1283 a new (previous) frame without having to first create it. This
1284 means that the convolution below - needing to carefully order a
1285 frame's initialization - isn't needed.
1287 The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
1288 for a more up-to-date architecture, always calls
1289 FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
1290 without first needing the frame! Instead of the convolution
1291 below, we could have simply called FRAME_SAVED_PC() and been done
1292 with it! Note that FRAME_SAVED_PC() is being superseed by
1293 frame_pc_unwind() and that function does have somewhere to cache
1296 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1297 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1299 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1300 DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1302 /* This entry is in the frame queue now, which is good since
1303 FRAME_SAVED_PC may use that queue to figure out its value (see
1304 tm-sparc.h). We want the pc saved in the inferior frame. */
1305 if (DEPRECATED_INIT_FRAME_PC_P ())
1306 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1308 /* If ->frame and ->pc are unchanged, we are in the process of
1309 getting ourselves into an infinite backtrace. Some architectures
1310 check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
1311 like there is no reason this can't be an architecture-independent
1313 if (prev
->frame
== this_frame
->frame
1314 && prev
->pc
== this_frame
->pc
)
1316 this_frame
->prev
= NULL
;
1317 obstack_free (&frame_cache_obstack
, prev
);
1321 /* Initialize the code used to unwind the frame PREV based on the PC
1322 (and probably other architectural information). The PC lets you
1323 check things like the debug info at that point (dwarf2cfi?) and
1324 use that to decide how the frame should be unwound. */
1325 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1327 /* NOTE: cagney/2002-11-18: The code segments, found in
1328 create_new_frame and get_prev_frame(), that initializes the
1329 frames type is subtly different. The latter only updates ->type
1330 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1331 get_prev_frame() overriding the frame's type when the INIT code
1332 has previously set it. This is really somewhat bogus. The
1333 initialization, as seen in create_new_frame(), should occur
1334 before the INIT function has been called. */
1335 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1336 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1337 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1338 : pc_in_dummy_frame (prev
->pc
)))
1339 prev
->type
= DUMMY_FRAME
;
1342 /* FIXME: cagney/2002-11-10: This should be moved to before the
1343 INIT code above so that the INIT code knows what the frame's
1344 type is (in fact, for a [generic] dummy-frame, the type can
1345 be set and then the entire initialization can be skipped.
1346 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1349 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1350 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1351 prev
->type
= SIGTRAMP_FRAME
;
1352 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1353 architectures are forcing the frame's type in INIT so we
1354 don't want to override it here. Remember, NORMAL_FRAME == 0,
1355 so it all works (just :-/). Once this initialization is
1356 moved to the start of this function, all this nastness will
1363 /* Return a structure containing various interesting information
1364 about the frame that called THIS_FRAME. Returns NULL
1365 if there is no such frame. */
1368 get_prev_frame (struct frame_info
*this_frame
)
1370 struct frame_info
*prev_frame
;
1372 /* Return the inner-most frame, when the caller passes in NULL. */
1373 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1374 caller should have previously obtained a valid frame using
1375 get_selected_frame() and then called this code - only possibility
1376 I can think of is code behaving badly.
1378 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1379 block_innermost_frame(). It does the sequence: frame = NULL;
1380 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1381 it couldn't be written better, I don't know.
1383 NOTE: cagney/2003-01-11: I suspect what is happening is
1384 block_innermost_frame() is, when the target has no state
1385 (registers, memory, ...), still calling this function. The
1386 assumption being that this function will return NULL indicating
1387 that a frame isn't possible, rather than checking that the target
1388 has state and then calling get_current_frame() and
1389 get_prev_frame(). This is a guess mind. */
1390 if (this_frame
== NULL
)
1392 /* NOTE: cagney/2002-11-09: There was a code segment here that
1393 would error out when CURRENT_FRAME was NULL. The comment
1394 that went with it made the claim ...
1396 ``This screws value_of_variable, which just wants a nice
1397 clean NULL return from block_innermost_frame if there are no
1398 frames. I don't think I've ever seen this message happen
1399 otherwise. And returning NULL here is a perfectly legitimate
1402 Per the above, this code shouldn't even be called with a NULL
1404 return current_frame
;
1407 /* There is always a frame. If this assertion fails, suspect that
1408 something should be calling get_selected_frame() or
1409 get_current_frame(). */
1410 gdb_assert (this_frame
!= NULL
);
1412 if (this_frame
->level
>= 0
1413 && !backtrace_below_main
1414 && inside_main_func (get_frame_pc (this_frame
)))
1415 /* Don't unwind past main(), bug always unwind the sentinel frame.
1416 Note, this is done _before_ the frame has been marked as
1417 previously unwound. That way if the user later decides to
1418 allow unwinds past main(), that just happens. */
1421 fprintf_unfiltered (gdb_stdlog
,
1422 "Outermost frame - inside main func.\n");
1426 /* Only try to do the unwind once. */
1427 if (this_frame
->prev_p
)
1428 return this_frame
->prev
;
1429 this_frame
->prev_p
= 1;
1431 /* If we're inside the entry file, it isn't valid. Don't apply this
1432 test to a dummy frame - dummy frame PC's typically land in the
1433 entry file. Don't apply this test to the sentinel frame.
1434 Sentinel frames should always be allowed to unwind. */
1435 /* NOTE: drow/2002-12-25: should there be a way to disable this
1436 check? It assumes a single small entry file, and the way some
1437 debug readers (e.g. dbxread) figure out which object is the
1438 entry file is somewhat hokey. */
1439 /* NOTE: cagney/2003-01-10: If there is a way of disabling this test
1440 then it should probably be moved to before the ->prev_p test,
1442 if (this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1443 && inside_entry_file (get_frame_pc (this_frame
)))
1446 fprintf_unfiltered (gdb_stdlog
,
1447 "Outermost frame - inside entry file\n");
1451 /* If we're already inside the entry function for the main objfile,
1452 then it isn't valid. Don't apply this test to a dummy frame -
1453 dummy frame PC's typically land in the entry func. Don't apply
1454 this test to the sentinel frame. Sentinel frames should always
1455 be allowed to unwind. */
1456 /* NOTE: cagney/2003-02-25: Don't enable until someone has found
1457 hard evidence that this is needed. */
1459 && this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1460 && inside_entry_func (get_frame_pc (this_frame
)))
1463 fprintf_unfiltered (gdb_stdlog
,
1464 "Outermost frame - inside entry func\n");
1468 /* If any of the old frame initialization methods are around, use
1469 the legacy get_prev_frame method. */
1470 if (legacy_frame_p (current_gdbarch
))
1472 prev_frame
= legacy_get_prev_frame (this_frame
);
1473 if (frame_debug
&& prev_frame
== NULL
)
1474 fprintf_unfiltered (gdb_stdlog
,
1475 "Outermost frame - legacy_get_prev_frame NULL.\n");
1479 /* Check that this frame's ID was valid. If it wasn't, don't try to
1480 unwind to the prev frame. Be careful to not apply this test to
1481 the sentinel frame. */
1482 if (this_frame
->level
>= 0 && !frame_id_p (get_frame_id (this_frame
)))
1485 fprintf_filtered (gdb_stdlog
,
1486 "Outermost frame - this ID is NULL\n");
1490 /* Check that this frame's ID isn't inner to (younger, below, next)
1491 the next frame. This happens when frame unwind goes backwards.
1492 Since the sentinel frame isn't valid, don't apply this if this
1493 frame is entier the inner-most or sentinel frame. */
1494 if (this_frame
->level
> 0
1495 && frame_id_inner (get_frame_id (this_frame
),
1496 get_frame_id (this_frame
->next
)))
1497 error ("This frame inner-to next frame (corrupt stack?)");
1499 /* Check that this and the next frame are different. If they are
1500 not, there is most likely a stack cycle. As with the inner-than
1501 test, avoid the inner-most and sentinel frames. */
1502 /* FIXME: cagney/2003-03-17: Can't yet enable this this check. The
1503 frame_id_eq() method doesn't yet use function addresses when
1504 comparing frame IDs. */
1506 && this_frame
->level
> 0
1507 && frame_id_eq (get_frame_id (this_frame
),
1508 get_frame_id (this_frame
->next
)))
1509 error ("This frame identical to next frame (corrupt stack?)");
1511 /* Allocate the new frame but do not wire it in to the frame chain.
1512 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1513 frame->next to pull some fancy tricks (of course such code is, by
1514 definition, recursive). Try to prevent it.
1516 There is no reason to worry about memory leaks, should the
1517 remainder of the function fail. The allocated memory will be
1518 quickly reclaimed when the frame cache is flushed, and the `we've
1519 been here before' check above will stop repeated memory
1520 allocation calls. */
1521 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1522 prev_frame
->level
= this_frame
->level
+ 1;
1524 /* Try to unwind the PC. If that doesn't work, assume we've reached
1525 the oldest frame and simply return. Is there a better sentinal
1526 value? The unwound PC value is then used to initialize the new
1527 previous frame's type.
1529 Note that the pc-unwind is intentionally performed before the
1530 frame chain. This is ok since, for old targets, both
1531 frame_pc_unwind (nee, FRAME_SAVED_PC) and
1532 DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
1533 have already been initialized (using
1534 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1537 By unwinding the PC first, it becomes possible to, in the case of
1538 a dummy frame, avoid also unwinding the frame ID. This is
1539 because (well ignoring the PPC) a dummy frame can be located
1540 using THIS_FRAME's frame ID. */
1542 prev_frame
->pc
= frame_pc_unwind (this_frame
);
1543 if (prev_frame
->pc
== 0)
1545 /* The allocated PREV_FRAME will be reclaimed when the frame
1546 obstack is next purged. */
1548 fprintf_unfiltered (gdb_stdlog
,
1549 "Outermost frame - unwound PC zero\n");
1552 prev_frame
->type
= frame_type_from_pc (prev_frame
->pc
);
1554 /* Set the unwind functions based on that identified PC. */
1555 prev_frame
->unwind
= frame_unwind_find_by_pc (current_gdbarch
,
1558 /* The prev's frame's ID is computed by demand in get_frame_id(). */
1560 /* The unwound frame ID is validate at the start of this function,
1561 as part of the logic to decide if that frame should be further
1562 unwound, and not here while the prev frame is being created.
1563 Doing this makes it possible for the user to examine a frame that
1564 has an invalid frame ID.
1566 The very old VAX frame_args_address_correct() method noted: [...]
1567 For the sake of argument, suppose that the stack is somewhat
1568 trashed (which is one reason that "info frame" exists). So,
1569 return 0 (indicating we don't know the address of the arglist) if
1570 we don't know what frame this frame calls. */
1573 this_frame
->prev
= prev_frame
;
1574 prev_frame
->next
= this_frame
;
1580 get_frame_pc (struct frame_info
*frame
)
1586 pc_notcurrent (struct frame_info
*frame
)
1588 /* If FRAME is not the innermost frame, that normally means that
1589 FRAME->pc points at the return instruction (which is *after* the
1590 call instruction), and we want to get the line containing the
1591 call (because the call is where the user thinks the program is).
1592 However, if the next frame is either a SIGTRAMP_FRAME or a
1593 DUMMY_FRAME, then the next frame will contain a saved interrupt
1594 PC and such a PC indicates the current (rather than next)
1595 instruction/line, consequently, for such cases, want to get the
1596 line containing fi->pc. */
1597 struct frame_info
*next
= get_next_frame (frame
);
1598 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1603 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1605 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1608 /* Per "frame.h", return the ``address'' of the frame. Code should
1609 really be using get_frame_id(). */
1611 get_frame_base (struct frame_info
*fi
)
1615 /* HACK: Force the ID code to (indirectly) initialize the
1622 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1623 or -1 for a NULL frame. */
1626 frame_relative_level (struct frame_info
*fi
)
1635 get_frame_type (struct frame_info
*frame
)
1637 /* Some targets still don't use [generic] dummy frames. Catch them
1639 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1640 && deprecated_frame_in_dummy (frame
))
1646 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1648 /* Arrrg! See comment in "frame.h". */
1652 #ifdef FRAME_FIND_SAVED_REGS
1653 /* XXX - deprecated. This is a compatibility function for targets
1654 that do not yet implement DEPRECATED_FRAME_INIT_SAVED_REGS. */
1655 /* Find the addresses in which registers are saved in FRAME. */
1658 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1659 struct frame_saved_regs
*saved_regs_addr
)
1661 if (frame
->saved_regs
== NULL
)
1663 frame
->saved_regs
= (CORE_ADDR
*)
1664 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
1666 if (saved_regs_addr
== NULL
)
1668 struct frame_saved_regs saved_regs
;
1669 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1670 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1674 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1675 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1680 struct frame_extra_info
*
1681 get_frame_extra_info (struct frame_info
*fi
)
1683 return fi
->extra_info
;
1686 struct frame_extra_info
*
1687 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1689 fi
->extra_info
= frame_obstack_zalloc (size
);
1690 return fi
->extra_info
;
1694 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
1696 /* See comment in "frame.h". */
1698 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
1699 maintaining a locally allocated frame object. Since such frame's
1700 are not in the frame chain, it isn't possible to assume that the
1701 frame has a next. Sigh. */
1702 if (frame
->next
!= NULL
)
1704 /* While we're at it, update this frame's cached PC value, found
1705 in the next frame. Oh for the day when "struct frame_info"
1706 is opaque and this hack on hack can just go away. */
1707 frame
->next
->pc_unwind_cache
= pc
;
1708 frame
->next
->pc_unwind_cache_p
= 1;
1713 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
1715 /* See comment in "frame.h". */
1716 frame
->frame
= base
;
1720 deprecated_set_frame_saved_regs_hack (struct frame_info
*frame
,
1721 CORE_ADDR
*saved_regs
)
1723 frame
->saved_regs
= saved_regs
;
1727 deprecated_set_frame_extra_info_hack (struct frame_info
*frame
,
1728 struct frame_extra_info
*extra_info
)
1730 frame
->extra_info
= extra_info
;
1734 deprecated_set_frame_next_hack (struct frame_info
*fi
,
1735 struct frame_info
*next
)
1741 deprecated_set_frame_prev_hack (struct frame_info
*fi
,
1742 struct frame_info
*prev
)
1748 deprecated_get_frame_context (struct frame_info
*fi
)
1754 deprecated_set_frame_context (struct frame_info
*fi
,
1755 struct context
*context
)
1757 fi
->context
= context
;
1761 deprecated_frame_xmalloc (void)
1763 struct frame_info
*frame
= XMALLOC (struct frame_info
);
1764 memset (frame
, 0, sizeof (struct frame_info
));
1769 deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs
,
1770 long sizeof_extra_info
)
1772 struct frame_info
*frame
= deprecated_frame_xmalloc ();
1773 make_cleanup (xfree
, frame
);
1774 if (sizeof_saved_regs
> 0)
1776 frame
->saved_regs
= xcalloc (1, sizeof_saved_regs
);
1777 make_cleanup (xfree
, frame
->saved_regs
);
1779 if (sizeof_extra_info
> 0)
1781 frame
->extra_info
= xcalloc (1, sizeof_extra_info
);
1782 make_cleanup (xfree
, frame
->extra_info
);
1788 legacy_frame_p (struct gdbarch
*current_gdbarch
)
1790 return (DEPRECATED_INIT_FRAME_PC_P ()
1791 || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
1792 || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
1793 || DEPRECATED_FRAME_CHAIN_P ()
1794 || !gdbarch_unwind_dummy_id_p (current_gdbarch
)
1795 || !SAVE_DUMMY_FRAME_TOS_P ());
1799 _initialize_frame (void)
1801 obstack_init (&frame_cache_obstack
);
1803 /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest
1804 `set backtrace {past,beyond,...}-main'. Also suggest adding `set
1805 backtrace ...-start' to control backtraces past start. The
1806 problem with `below' is that it stops the `up' command. */
1808 add_setshow_boolean_cmd ("backtrace-below-main", class_obscure
,
1809 &backtrace_below_main
, "\
1810 Set whether backtraces should continue past \"main\".\n\
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.", "\
1814 Show whether backtraces should continue past \"main\".\n\
1815 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1816 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1817 of the stack trace.",
1818 NULL
, NULL
, &setlist
, &showlist
);
1821 /* Debug this files internals. */
1822 add_show_from_set (add_set_cmd ("frame", class_maintenance
, var_zinteger
,
1823 &frame_debug
, "Set frame debugging.\n\
1824 When non-zero, frame specific internal debugging is enabled.", &setdebuglist
),