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
)
69 const struct frame_id null_frame_id
; /* All zeros. */
72 frame_id_build (CORE_ADDR base
, CORE_ADDR func_or_pc
)
81 frame_id_p (struct frame_id l
)
83 /* The .func can be NULL but the .base cannot. */
88 frame_id_eq (struct frame_id l
, struct frame_id r
)
90 /* If .base is different, the frames are different. */
93 /* Add a test to check that the frame ID's are for the same function
99 frame_id_inner (struct frame_id l
, struct frame_id r
)
101 /* Only return non-zero when strictly inner than. Note that, per
102 comment in "frame.h", there is some fuzz here. Frameless
103 functions are not strictly inner than (same .base but different
105 return INNER_THAN (l
.base
, r
.base
);
109 frame_find_by_id (struct frame_id id
)
111 struct frame_info
*frame
;
113 /* ZERO denotes the null frame, let the caller decide what to do
114 about it. Should it instead return get_current_frame()? */
115 if (!frame_id_p (id
))
118 for (frame
= get_current_frame ();
120 frame
= get_prev_frame (frame
))
122 struct frame_id
this = get_frame_id (frame
);
123 if (frame_id_eq (id
, this))
124 /* An exact match. */
126 if (frame_id_inner (id
, this))
129 /* Either, we're not yet gone far enough out along the frame
130 chain (inner(this,id), or we're comparing frameless functions
131 (same .base, different .func, no test available). Struggle
132 on until we've definitly gone to far. */
138 frame_pc_unwind (struct frame_info
*this_frame
)
140 if (!this_frame
->pc_unwind_cache_p
)
143 if (gdbarch_unwind_pc_p (current_gdbarch
))
145 /* The right way. The `pure' way. The one true way. This
146 method depends solely on the register-unwind code to
147 determine the value of registers in THIS frame, and hence
148 the value of this frame's PC (resume address). A typical
149 implementation is no more than:
151 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
152 return extract_address (buf, size of ISA_PC_REGNUM);
154 Note: this method is very heavily dependent on a correct
155 register-unwind implementation, it pays to fix that
156 method first; this method is frame type agnostic, since
157 it only deals with register values, it works with any
158 frame. This is all in stark contrast to the old
159 FRAME_SAVED_PC which would try to directly handle all the
160 different ways that a PC could be unwound. */
161 pc
= gdbarch_unwind_pc (current_gdbarch
, this_frame
);
163 else if (this_frame
->level
< 0)
165 /* FIXME: cagney/2003-03-06: Old code and and a sentinel
166 frame. Do like was always done. Fetch the PC's value
167 direct from the global registers array (via read_pc).
168 This assumes that this frame belongs to the current
169 global register cache. The assumption is dangerous. */
172 else if (DEPRECATED_FRAME_SAVED_PC_P ())
174 /* FIXME: cagney/2003-03-06: Old code, but not a sentinel
175 frame. Do like was always done. Note that this method,
176 unlike unwind_pc(), tries to handle all the different
177 frame cases directly. It fails. */
178 pc
= DEPRECATED_FRAME_SAVED_PC (this_frame
);
181 internal_error (__FILE__
, __LINE__
, "No gdbarch_unwind_pc method");
182 this_frame
->pc_unwind_cache
= pc
;
183 this_frame
->pc_unwind_cache_p
= 1;
185 return this_frame
->pc_unwind_cache
;
189 do_frame_unwind_register (void *src
, int regnum
, void *buf
)
191 frame_unwind_register (src
, regnum
, buf
);
196 frame_pop (struct frame_info
*this_frame
)
198 struct regcache
*scratch_regcache
;
199 struct cleanup
*cleanups
;
201 if (DEPRECATED_POP_FRAME_P ())
203 /* A legacy architecture that has implemented a custom pop
204 function. All new architectures should instead be using the
205 generic code below. */
206 DEPRECATED_POP_FRAME
;
210 /* Make a copy of all the register values unwound from this
211 frame. Save them in a scratch buffer so that there isn't a
212 race betweening trying to extract the old values from the
213 current_regcache while, at the same time writing new values
214 into that same cache. */
215 struct regcache
*scratch
= regcache_xmalloc (current_gdbarch
);
216 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (scratch
);
217 regcache_save (scratch
, do_frame_unwind_register
, this_frame
);
218 /* FIXME: cagney/2003-03-16: It should be possible to tell the
219 target's register cache that it is about to be hit with a
220 burst register transfer and that the sequence of register
221 writes should be batched. The pair target_prepare_to_store()
222 and target_store_registers() kind of suggest this
223 functionality. Unfortunatly, they don't implement it. Their
224 lack of a formal definition can lead to targets writing back
225 bogus values (arguably a bug in the target code mind). */
226 /* Now copy those saved registers into the current regcache.
227 Here, regcache_cpy() calls regcache_restore(). */
228 regcache_cpy (current_regcache
, scratch
);
229 do_cleanups (cleanups
);
231 /* We've made right mess of GDB's local state, just discard
233 flush_cached_frames ();
237 frame_register_unwind (struct frame_info
*frame
, int regnum
,
238 int *optimizedp
, enum lval_type
*lvalp
,
239 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
241 struct frame_unwind_cache
*cache
;
243 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
244 that the value proper does not need to be fetched. */
245 gdb_assert (optimizedp
!= NULL
);
246 gdb_assert (lvalp
!= NULL
);
247 gdb_assert (addrp
!= NULL
);
248 gdb_assert (realnump
!= NULL
);
249 /* gdb_assert (bufferp != NULL); */
251 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
252 is broken. There is always a frame. If there, for some reason,
253 isn't, there is some pretty busted code as it should have
254 detected the problem before calling here. */
255 gdb_assert (frame
!= NULL
);
257 /* Ask this frame to unwind its register. See comment in
258 "frame-unwind.h" for why NEXT frame and this unwind cace are
260 frame
->unwind
->prev_register (frame
->next
, &frame
->prologue_cache
, regnum
,
261 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
266 frame_register (struct frame_info
*frame
, int regnum
,
267 int *optimizedp
, enum lval_type
*lvalp
,
268 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
270 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
271 that the value proper does not need to be fetched. */
272 gdb_assert (optimizedp
!= NULL
);
273 gdb_assert (lvalp
!= NULL
);
274 gdb_assert (addrp
!= NULL
);
275 gdb_assert (realnump
!= NULL
);
276 /* gdb_assert (bufferp != NULL); */
278 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
279 of the register in the register cache. It should instead return
280 the REGNUM corresponding to that register. Translate the . */
281 if (DEPRECATED_GET_SAVED_REGISTER_P ())
283 DEPRECATED_GET_SAVED_REGISTER (bufferp
, optimizedp
, addrp
, frame
,
285 /* Compute the REALNUM if the caller wants it. */
286 if (*lvalp
== lval_register
)
289 for (regnum
= 0; regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
; regnum
++)
291 if (*addrp
== register_offset_hack (current_gdbarch
, regnum
))
297 internal_error (__FILE__
, __LINE__
,
298 "Failed to compute the register number corresponding"
299 " to 0x%s", paddr_d (*addrp
));
305 /* Obtain the register value by unwinding the register from the next
306 (more inner frame). */
307 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
308 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
313 frame_unwind_register (struct frame_info
*frame
, int regnum
, void *buf
)
319 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
324 frame_unwind_signed_register (struct frame_info
*frame
, int regnum
,
327 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
328 frame_unwind_register (frame
, regnum
, buf
);
329 (*val
) = extract_signed_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
333 frame_unwind_unsigned_register (struct frame_info
*frame
, int regnum
,
336 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
337 frame_unwind_register (frame
, regnum
, buf
);
338 (*val
) = extract_unsigned_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
342 frame_read_register (struct frame_info
*frame
, int regnum
, void *buf
)
344 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
345 frame_unwind_register (frame
->next
, regnum
, buf
);
349 frame_read_unsigned_register (struct frame_info
*frame
, int regnum
,
352 /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is
353 always a frame. Both this, and the equivalent
354 frame_read_signed_register() function, can only be called with a
355 valid frame. If, for some reason, this function is called
356 without a frame then the problem isn't here, but rather in the
357 caller. It should of first created a frame and then passed that
359 /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the
360 ``current_frame'' should not be treated as a special case. While
361 ``get_next_frame (current_frame) == NULL'' currently holds, it
362 should, as far as possible, not be relied upon. In the future,
363 ``get_next_frame (current_frame)'' may instead simply return a
364 normal frame object that simply always gets register values from
365 the register cache. Consequently, frame code should try to avoid
366 tests like ``if get_next_frame() == NULL'' and instead just rely
367 on recursive frame calls (like the below code) when manipulating
369 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
370 frame_unwind_unsigned_register (frame
->next
, regnum
, val
);
374 frame_read_signed_register (struct frame_info
*frame
, int regnum
,
377 /* See note above in frame_read_unsigned_register(). */
378 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
379 frame_unwind_signed_register (frame
->next
, regnum
, val
);
383 generic_unwind_get_saved_register (char *raw_buffer
,
386 struct frame_info
*frame
,
388 enum lval_type
*lvalp
)
393 enum lval_type lvalx
;
395 if (!target_has_registers
)
396 error ("No registers.");
398 /* Keep things simple, ensure that all the pointers (except valuep)
400 if (optimizedp
== NULL
)
401 optimizedp
= &optimizedx
;
407 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
408 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
409 &realnumx
, raw_buffer
);
412 /* frame_register_read ()
414 Find and return the value of REGNUM for the specified stack frame.
415 The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
417 Returns 0 if the register value could not be found. */
420 frame_register_read (struct frame_info
*frame
, int regnum
, void *myaddr
)
426 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
428 /* FIXME: cagney/2002-05-15: This test, is just bogus.
430 It indicates that the target failed to supply a value for a
431 register because it was "not available" at this time. Problem
432 is, the target still has the register and so get saved_register()
433 may be returning a value saved on the stack. */
435 if (register_cached (regnum
) < 0)
436 return 0; /* register value not available */
442 /* Map between a frame register number and its name. A frame register
443 space is a superset of the cooked register space --- it also
444 includes builtin registers. */
447 frame_map_name_to_regnum (const char *name
, int len
)
454 /* Search register name space. */
455 for (i
= 0; i
< NUM_REGS
+ NUM_PSEUDO_REGS
; i
++)
456 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
457 && strncmp (name
, REGISTER_NAME (i
), len
) == 0)
462 /* Try builtin registers. */
463 i
= builtin_reg_map_name_to_regnum (name
, len
);
466 /* A builtin register doesn't fall into the architecture's
468 gdb_assert (i
>= NUM_REGS
+ NUM_PSEUDO_REGS
);
476 frame_map_regnum_to_name (int regnum
)
480 if (regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
)
481 return REGISTER_NAME (regnum
);
482 return builtin_reg_map_regnum_to_name (regnum
);
485 /* Create a sentinel frame. */
488 create_sentinel_frame (struct regcache
*regcache
)
490 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
491 frame
->type
= NORMAL_FRAME
;
493 /* Explicitly initialize the sentinel frame's cache. Provide it
494 with the underlying regcache. In the future additional
495 information, such as the frame's thread will be added. */
496 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
497 /* For the moment there is only one sentinel frame implementation. */
498 frame
->unwind
= sentinel_frame_unwind
;
499 /* Link this frame back to itself. The frame is self referential
500 (the unwound PC is the same as the pc), so make it so. */
502 /* Always unwind the PC as part of creating this frame. This
503 ensures that the frame's PC points at something valid. */
504 /* FIXME: cagney/2003-01-10: Problem here. Unwinding a sentinel
505 frame's PC may require information such as the frame's thread's
506 stop reason. Is it possible to get to that? */
507 frame
->pc
= frame_pc_unwind (frame
);
511 /* Info about the innermost stack frame (contents of FP register) */
513 static struct frame_info
*current_frame
;
515 /* Cache for frame addresses already read by gdb. Valid only while
516 inferior is stopped. Control variables for the frame cache should
517 be local to this module. */
519 static struct obstack frame_cache_obstack
;
522 frame_obstack_zalloc (unsigned long size
)
524 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
525 memset (data
, 0, size
);
530 frame_saved_regs_zalloc (struct frame_info
*fi
)
532 fi
->saved_regs
= (CORE_ADDR
*)
533 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
534 return fi
->saved_regs
;
538 get_frame_saved_regs (struct frame_info
*fi
)
540 return fi
->saved_regs
;
543 /* Return the innermost (currently executing) stack frame. This is
544 split into two functions. The function unwind_to_current_frame()
545 is wrapped in catch exceptions so that, even when the unwind of the
546 sentinel frame fails, the function still returns a stack frame. */
549 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
551 struct frame_info
*frame
= get_prev_frame (args
);
552 /* A sentinel frame can fail to unwind, eg, because it's PC value
553 lands in somewhere like start. */
556 current_frame
= frame
;
561 get_current_frame (void)
563 /* First check, and report, the lack of registers. Having GDB
564 report "No stack!" or "No memory" when the target doesn't even
565 have registers is very confusing. Besides, "printcmd.exp"
566 explicitly checks that ``print $pc'' with no registers prints "No
568 if (!target_has_registers
)
569 error ("No registers.");
570 if (!target_has_stack
)
572 if (!target_has_memory
)
573 error ("No memory.");
574 if (current_frame
== NULL
)
576 struct frame_info
*sentinel_frame
=
577 create_sentinel_frame (current_regcache
);
578 if (catch_exceptions (uiout
, unwind_to_current_frame
, sentinel_frame
,
579 NULL
, RETURN_MASK_ERROR
) != 0)
581 /* Oops! Fake a current frame? Is this useful? It has a PC
582 of zero, for instance. */
583 current_frame
= sentinel_frame
;
586 return current_frame
;
589 /* The "selected" stack frame is used by default for local and arg
590 access. May be zero, for no selected frame. */
592 struct frame_info
*deprecated_selected_frame
;
594 /* Return the selected frame. Always non-null (unless there isn't an
595 inferior sufficient for creating a frame) in which case an error is
599 get_selected_frame (void)
601 if (deprecated_selected_frame
== NULL
)
602 /* Hey! Don't trust this. It should really be re-finding the
603 last selected frame of the currently selected thread. This,
604 though, is better than nothing. */
605 select_frame (get_current_frame ());
606 /* There is always a frame. */
607 gdb_assert (deprecated_selected_frame
!= NULL
);
608 return deprecated_selected_frame
;
611 /* Select frame FI (or NULL - to invalidate the current frame). */
614 select_frame (struct frame_info
*fi
)
616 register struct symtab
*s
;
618 deprecated_selected_frame
= fi
;
619 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
620 frame is being invalidated. */
621 if (selected_frame_level_changed_hook
)
622 selected_frame_level_changed_hook (frame_relative_level (fi
));
624 /* FIXME: kseitz/2002-08-28: It would be nice to call
625 selected_frame_level_changed_event right here, but due to limitations
626 in the current interfaces, we would end up flooding UIs with events
627 because select_frame is used extensively internally.
629 Once we have frame-parameterized frame (and frame-related) commands,
630 the event notification can be moved here, since this function will only
631 be called when the users selected frame is being changed. */
633 /* Ensure that symbols for this frame are read in. Also, determine the
634 source language of this frame, and switch to it if desired. */
637 s
= find_pc_symtab (fi
->pc
);
639 && s
->language
!= current_language
->la_language
640 && s
->language
!= language_unknown
641 && language_mode
== language_mode_auto
)
643 set_language (s
->language
);
648 /* Return the register saved in the simplistic ``saved_regs'' cache.
649 If the value isn't here AND a value is needed, try the next inner
653 legacy_saved_regs_prev_register (struct frame_info
*next_frame
,
654 void **this_prologue_cache
,
655 int regnum
, int *optimizedp
,
656 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
657 int *realnump
, void *bufferp
)
659 /* HACK: New code is passed the next frame and this cache.
660 Unfortunatly, old code expects this frame. Since this is a
661 backward compatibility hack, cheat by walking one level along the
662 prologue chain to the frame the old code expects.
664 Do not try this at home. Professional driver, closed course. */
665 struct frame_info
*frame
= next_frame
->prev
;
666 gdb_assert (frame
!= NULL
);
668 /* Only (older) architectures that implement the
669 DEPRECATED_FRAME_INIT_SAVED_REGS method should be using this
671 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
673 /* Load the saved_regs register cache. */
674 if (get_frame_saved_regs (frame
) == NULL
)
675 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
677 if (get_frame_saved_regs (frame
) != NULL
678 && get_frame_saved_regs (frame
)[regnum
] != 0)
680 if (regnum
== SP_REGNUM
)
682 /* SP register treated specially. */
688 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
689 get_frame_saved_regs (frame
)[regnum
]);
693 /* Any other register is saved in memory, fetch it but cache
694 a local copy of its value. */
696 *lvalp
= lval_memory
;
697 *addrp
= get_frame_saved_regs (frame
)[regnum
];
702 /* Save each register value, as it is read in, in a
703 frame based cache. */
704 void **regs
= (*this_prologue_cache
);
707 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
709 regs
= frame_obstack_zalloc (sizeof_cache
);
710 (*this_prologue_cache
) = regs
;
712 if (regs
[regnum
] == NULL
)
715 = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum
));
716 read_memory (get_frame_saved_regs (frame
)[regnum
], regs
[regnum
],
717 REGISTER_RAW_SIZE (regnum
));
719 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
721 /* Read the value in from memory. */
722 read_memory (get_frame_saved_regs (frame
)[regnum
], bufferp
,
723 REGISTER_RAW_SIZE (regnum
));
730 /* No luck. Assume this and the next frame have the same register
731 value. Pass the unwind request down the frame chain to the next
732 frame. Hopefully that frame will find the register's location. */
733 frame_register_unwind (next_frame
, regnum
, optimizedp
, lvalp
, addrp
,
738 legacy_saved_regs_this_id (struct frame_info
*next_frame
,
739 void **this_prologue_cache
,
746 if (frame_relative_level (next_frame
) < 0)
748 /* FIXME: cagney/2003-03-14: We've got the extra special case of
749 unwinding a sentinel frame, the PC of which is pointing at a
750 stack dummy. Fake up the dummy frame's ID using the same
751 sequence as is found a traditional unwinder. */
752 (*id
).base
= read_fp ();
753 (*id
).pc
= read_pc ();
757 /* Start out by assuming it's NULL. */
758 (*id
) = null_frame_id
;
760 if (frame_relative_level (next_frame
) <= 0)
761 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
762 the frame chain, not just the inner most frame! The generic,
763 per-architecture, frame code should handle this and the below
764 should simply be removed. */
765 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
770 /* A frameless inner-most frame. The `FP' (which isn't an
771 architecture frame-pointer register!) of the caller is the same
773 /* FIXME: 2002-11-09: There isn't any reason to special case this
774 edge condition. Instead the per-architecture code should hande
776 base
= get_frame_base (next_frame
);
779 /* Two macros defined in tm.h specify the machine-dependent
780 actions to be performed here.
782 First, get the frame's chain-pointer.
784 If that is zero, the frame is the outermost frame or a leaf
785 called by the outermost frame. This means that if start
786 calls main without a frame, we'll return 0 (which is fine
789 Nope; there's a problem. This also returns when the current
790 routine is a leaf of main. This is unacceptable. We move
791 this to after the ffi test; I'd rather have backtraces from
792 start go curfluy than have an abort called from main not show
794 gdb_assert (FRAME_CHAIN_P ());
795 base
= FRAME_CHAIN (next_frame
);
797 if (!frame_chain_valid (base
, next_frame
))
803 /* FIXME: cagney/2002-06-08: This should probably return the frame's
804 function and not the PC (a.k.a. resume address). */
805 pc
= frame_pc_unwind (next_frame
);
810 const struct frame_unwind legacy_saved_regs_unwinder
= {
811 legacy_saved_regs_this_id
,
812 legacy_saved_regs_prev_register
814 const struct frame_unwind
*legacy_saved_regs_unwind
= &legacy_saved_regs_unwinder
;
817 /* Function: deprecated_generic_get_saved_register
818 Find register number REGNUM relative to FRAME and put its (raw,
819 target format) contents in *RAW_BUFFER.
821 Set *OPTIMIZED if the variable was optimized out (and thus can't be
822 fetched). Note that this is never set to anything other than zero
823 in this implementation.
825 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
826 whether the value was fetched from memory, from a register, or in a
827 strange and non-modifiable way (e.g. a frame pointer which was
828 calculated rather than fetched). We will use not_lval for values
829 fetched from generic dummy frames.
831 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
832 offset into the registers array. If the value is stored in a dummy
833 frame, set *ADDRP to zero.
835 The argument RAW_BUFFER must point to aligned memory. */
838 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
840 struct frame_info
*frame
, int regnum
,
841 enum lval_type
*lval
)
843 if (!target_has_registers
)
844 error ("No registers.");
846 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
848 /* Normal systems don't optimize out things with register numbers. */
849 if (optimized
!= NULL
)
852 if (addrp
) /* default assumption: not found in memory */
855 /* Note: since the current frame's registers could only have been
856 saved by frames INTERIOR TO the current frame, we skip examining
857 the current frame itself: otherwise, we would be getting the
858 previous frame's registers which were saved by the current frame. */
862 for (frame
= get_next_frame (frame
);
863 frame_relative_level (frame
) >= 0;
864 frame
= get_next_frame (frame
))
866 if (get_frame_type (frame
) == DUMMY_FRAME
)
868 if (lval
) /* found it in a CALL_DUMMY frame */
871 /* FIXME: cagney/2002-06-26: This should be via the
872 gdbarch_register_read() method so that it, on the
873 fly, constructs either a raw or pseudo register
874 from the raw register cache. */
876 (generic_find_dummy_frame (get_frame_pc (frame
),
877 get_frame_base (frame
)),
882 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
883 if (get_frame_saved_regs (frame
) != NULL
884 && get_frame_saved_regs (frame
)[regnum
] != 0)
886 if (lval
) /* found it saved on the stack */
888 if (regnum
== SP_REGNUM
)
890 if (raw_buffer
) /* SP register treated specially */
891 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
892 get_frame_saved_regs (frame
)[regnum
]);
896 if (addrp
) /* any other register */
897 *addrp
= get_frame_saved_regs (frame
)[regnum
];
899 read_memory (get_frame_saved_regs (frame
)[regnum
], raw_buffer
,
900 REGISTER_RAW_SIZE (regnum
));
907 /* If we get thru the loop to this point, it means the register was
908 not saved in any frame. Return the actual live-register value. */
910 if (lval
) /* found it in a live register */
911 *lval
= lval_register
;
913 *addrp
= REGISTER_BYTE (regnum
);
915 deprecated_read_register_gen (regnum
, raw_buffer
);
918 /* Determine the frame's type based on its PC. */
920 static enum frame_type
921 frame_type_from_pc (CORE_ADDR pc
)
923 /* FIXME: cagney/2002-11-24: Can't yet directly call
924 pc_in_dummy_frame() as some architectures don't set
925 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
926 latter is implemented by simply calling pc_in_dummy_frame). */
927 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
928 && DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0))
933 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
934 if (PC_IN_SIGTRAMP (pc
, name
))
935 return SIGTRAMP_FRAME
;
941 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
942 Always returns a non-NULL value. */
945 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
947 struct frame_info
*fi
;
949 fi
= frame_obstack_zalloc (sizeof (struct frame_info
));
953 fi
->next
= create_sentinel_frame (current_regcache
);
954 fi
->type
= frame_type_from_pc (pc
);
956 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
957 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi
);
959 /* Select/initialize an unwind function. */
960 fi
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, fi
->pc
);
965 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
966 innermost frame). Be careful to not fall off the bottom of the
967 frame chain and onto the sentinel frame. */
970 get_next_frame (struct frame_info
*this_frame
)
972 if (this_frame
->level
> 0)
973 return this_frame
->next
;
978 /* Flush the entire frame cache. */
981 flush_cached_frames (void)
983 /* Since we can't really be sure what the first object allocated was */
984 obstack_free (&frame_cache_obstack
, 0);
985 obstack_init (&frame_cache_obstack
);
987 current_frame
= NULL
; /* Invalidate cache */
989 annotate_frames_invalid ();
992 /* Flush the frame cache, and start a new one if necessary. */
995 reinit_frame_cache (void)
997 flush_cached_frames ();
999 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
1000 if (PIDGET (inferior_ptid
) != 0)
1002 select_frame (get_current_frame ());
1006 /* Create the previous frame using the deprecated methods
1007 INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
1009 static struct frame_info
*
1010 legacy_get_prev_frame (struct frame_info
*this_frame
)
1012 CORE_ADDR address
= 0;
1013 struct frame_info
*prev
;
1016 /* Allocate the new frame but do not wire it in to the frame chain.
1017 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1018 frame->next to pull some fancy tricks (of course such code is, by
1019 definition, recursive). Try to prevent it.
1021 There is no reason to worry about memory leaks, should the
1022 remainder of the function fail. The allocated memory will be
1023 quickly reclaimed when the frame cache is flushed, and the `we've
1024 been here before' check, in get_prev_frame will stop repeated
1025 memory allocation calls. */
1026 prev
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1027 prev
->level
= this_frame
->level
+ 1;
1029 /* NOTE: cagney/2002-11-18: Should have been correctly setting the
1030 frame's type here, before anything else, and not last, at the
1031 bottom of this function. The various
1032 DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
1033 DEPRECATED_INIT_FRAME_PC_FIRST and
1034 DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
1035 that handle the frame not being correctly set from the start.
1036 Unfortunatly those same work-arounds rely on the type defaulting
1037 to NORMAL_FRAME. Ulgh! The new frame code does not have this
1039 prev
->type
= NORMAL_FRAME
;
1041 /* Handle sentinel frame unwind as a special case. */
1042 if (this_frame
->level
< 0)
1044 /* Try to unwind the PC. If that doesn't work, assume we've reached
1045 the oldest frame and simply return. Is there a better sentinal
1046 value? The unwound PC value is then used to initialize the new
1047 previous frame's type.
1049 Note that the pc-unwind is intentionally performed before the
1050 frame chain. This is ok since, for old targets, both
1051 frame_pc_unwind (nee, FRAME_SAVED_PC) and FRAME_CHAIN()) assume
1052 THIS_FRAME's data structures have already been initialized (using
1053 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1056 By unwinding the PC first, it becomes possible to, in the case of
1057 a dummy frame, avoid also unwinding the frame ID. This is
1058 because (well ignoring the PPC) a dummy frame can be located
1059 using THIS_FRAME's frame ID. */
1061 prev
->pc
= frame_pc_unwind (this_frame
);
1064 /* The allocated PREV_FRAME will be reclaimed when the frame
1065 obstack is next purged. */
1067 fprintf_unfiltered (gdb_stdlog
,
1068 "Outermost frame - unwound PC zero\n");
1071 prev
->type
= frame_type_from_pc (prev
->pc
);
1073 /* Set the unwind functions based on that identified PC. */
1074 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1076 /* Find the prev's frame's ID. */
1077 if (prev
->type
== DUMMY_FRAME
1078 && gdbarch_unwind_dummy_id_p (current_gdbarch
))
1080 /* When unwinding a normal frame, the stack structure is
1081 determined by analyzing the frame's function's code (be
1082 it using brute force prologue analysis, or the dwarf2
1083 CFI). In the case of a dummy frame, that simply isn't
1084 possible. The The PC is either the program entry point,
1085 or some random address on the stack. Trying to use that
1086 PC to apply standard frame ID unwind techniques is just
1087 asking for trouble. */
1088 /* Assume hand_function_call(), via SAVE_DUMMY_FRAME_TOS,
1089 previously saved the dummy frame's ID. Things only work
1090 if the two return the same value. */
1091 gdb_assert (SAVE_DUMMY_FRAME_TOS_P ());
1092 /* Use an architecture specific method to extract the prev's
1093 dummy ID from the next frame. Note that this method uses
1094 frame_register_unwind to obtain the register values
1095 needed to determine the dummy frame's ID. */
1096 prev
->id
= gdbarch_unwind_dummy_id (current_gdbarch
, this_frame
);
1100 /* We're unwinding a sentinel frame, the PC of which is
1101 pointing at a stack dummy. Fake up the dummy frame's ID
1102 using the same sequence as is found a traditional
1103 unwinder. Once all architectures supply the
1104 unwind_dummy_id method, this code can go away. */
1105 prev
->id
.base
= read_fp ();
1106 prev
->id
.pc
= read_pc ();
1109 /* Check that the unwound ID is valid. */
1110 if (!frame_id_p (prev
->id
))
1113 fprintf_unfiltered (gdb_stdlog
,
1114 "Outermost legacy sentinel frame - unwound frame ID invalid\n");
1118 /* Check that the new frame isn't inner to (younger, below,
1119 next) the old frame. If that happens the frame unwind is
1121 /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
1122 that doesn't have a valid frame ID. Should instead set the
1123 sentinel frame's frame ID to a `sentinel'. Leave it until
1124 after the switch to storing the frame ID, instead of the
1125 frame base, in the frame object. */
1127 /* FIXME: cagney/2002-12-18: Instead of this hack, should only
1128 store the frame ID in PREV_FRAME. Unfortunatly, some
1129 architectures (HP/UX) still reply on EXTRA_FRAME_INFO and,
1130 hence, still poke at the "struct frame_info" object directly. */
1131 prev
->frame
= prev
->id
.base
;
1134 this_frame
->prev
= prev
;
1135 prev
->next
= this_frame
;
1137 /* FIXME: cagney/2002-01-19: This call will go away. Instead of
1138 initializing extra info, all frames will use the frame_cache
1139 (passed to the unwind functions) to store additional frame
1140 info. Unfortunatly legacy targets can't use
1141 legacy_get_prev_frame() to unwind the sentinel frame and,
1142 consequently, are forced to take this code path and rely on
1143 the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
1144 initialize the inner-most frame. */
1145 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1147 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev
);
1152 /* This code only works on normal frames. A sentinel frame, where
1153 the level is -1, should never reach this code. */
1154 gdb_assert (this_frame
->level
>= 0);
1156 /* On some machines it is possible to call a function without
1157 setting up a stack frame for it. On these machines, we
1158 define this macro to take two args; a frameinfo pointer
1159 identifying a frame and a variable to set or clear if it is
1160 or isn't leafless. */
1162 /* Still don't want to worry about this except on the innermost
1163 frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
1164 function invocation. */
1165 if (this_frame
->level
== 0)
1166 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
1167 the frame chain, not just the inner most frame! The generic,
1168 per-architecture, frame code should handle this and the below
1169 should simply be removed. */
1170 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (this_frame
);
1175 /* A frameless inner-most frame. The `FP' (which isn't an
1176 architecture frame-pointer register!) of the caller is the same
1178 /* FIXME: 2002-11-09: There isn't any reason to special case this
1179 edge condition. Instead the per-architecture code should hande
1181 address
= get_frame_base (this_frame
);
1184 /* Two macros defined in tm.h specify the machine-dependent
1185 actions to be performed here.
1187 First, get the frame's chain-pointer.
1189 If that is zero, the frame is the outermost frame or a leaf
1190 called by the outermost frame. This means that if start
1191 calls main without a frame, we'll return 0 (which is fine
1194 Nope; there's a problem. This also returns when the current
1195 routine is a leaf of main. This is unacceptable. We move
1196 this to after the ffi test; I'd rather have backtraces from
1197 start go curfluy than have an abort called from main not show
1199 gdb_assert (FRAME_CHAIN_P ());
1200 address
= FRAME_CHAIN (this_frame
);
1202 if (!frame_chain_valid (address
, this_frame
))
1208 /* Link in the already allocated prev frame. */
1209 this_frame
->prev
= prev
;
1210 prev
->next
= this_frame
;
1211 prev
->frame
= address
;
1213 /* This change should not be needed, FIXME! We should determine
1214 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1215 after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
1216 way to express what goes on here.
1218 DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
1219 create_new_frame (where the PC is already set up) and here (where
1220 it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
1221 always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
1223 The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
1224 requires the PC value (which hasn't been set yet). Some other
1225 machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
1226 before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
1228 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1229 complication to an already overcomplicated part of GDB.
1230 gnu@cygnus.com, 15Sep92.
1232 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1233 DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
1235 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1236 (read_fp ()), read_pc ()). Machines with extra frame info would
1237 do that (or the local equivalent) and then set the extra fields.
1239 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1240 create_new_frame would no longer init extra frame info;
1241 SETUP_ARBITRARY_FRAME would have to do that.
1243 INIT_PREV_FRAME(fromleaf, prev) Replace
1244 DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
1245 This should also return a flag saying whether to keep the new
1246 frame, or whether to discard it, because on some machines (e.g.
1247 mips) it is really awkward to have FRAME_CHAIN_VALID called
1248 BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good way to
1249 get information deduced in FRAME_CHAIN_VALID into the extra
1250 fields of the new frame). std_frame_pc(fromleaf, prev)
1252 This is the default setting for INIT_PREV_FRAME. It just does
1253 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1254 will call it from INIT_PREV_FRAME (either at the beginning, the
1255 end, or in the middle). Some machines won't use it.
1257 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1259 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1260 reason for things to be this complicated.
1262 The trick is to assume that there is always a frame. Instead of
1263 special casing the inner-most frame, create fake frame
1264 (containing the hardware registers) that is inner to the
1265 user-visible inner-most frame (...) and then unwind from that.
1266 That way architecture code can use use the standard
1267 frame_XX_unwind() functions and not differentiate between the
1268 inner most and any other case.
1270 Since there is always a frame to unwind from, there is always
1271 somewhere (THIS_FRAME) to store all the info needed to construct
1272 a new (previous) frame without having to first create it. This
1273 means that the convolution below - needing to carefully order a
1274 frame's initialization - isn't needed.
1276 The irony here though, is that FRAME_CHAIN(), at least for a more
1277 up-to-date architecture, always calls FRAME_SAVED_PC(), and
1278 FRAME_SAVED_PC() computes the PC but without first needing the
1279 frame! Instead of the convolution below, we could have simply
1280 called FRAME_SAVED_PC() and been done with it! Note that
1281 FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
1282 function does have somewhere to cache that PC value. */
1284 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1285 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1287 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1288 DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1290 /* This entry is in the frame queue now, which is good since
1291 FRAME_SAVED_PC may use that queue to figure out its value (see
1292 tm-sparc.h). We want the pc saved in the inferior frame. */
1293 if (DEPRECATED_INIT_FRAME_PC_P ())
1294 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1296 /* If ->frame and ->pc are unchanged, we are in the process of
1297 getting ourselves into an infinite backtrace. Some architectures
1298 check this in FRAME_CHAIN or thereabouts, but it seems like there
1299 is no reason this can't be an architecture-independent check. */
1300 if (prev
->frame
== this_frame
->frame
1301 && prev
->pc
== this_frame
->pc
)
1303 this_frame
->prev
= NULL
;
1304 obstack_free (&frame_cache_obstack
, prev
);
1308 /* Initialize the code used to unwind the frame PREV based on the PC
1309 (and probably other architectural information). The PC lets you
1310 check things like the debug info at that point (dwarf2cfi?) and
1311 use that to decide how the frame should be unwound. */
1312 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1314 /* NOTE: cagney/2002-11-18: The code segments, found in
1315 create_new_frame and get_prev_frame(), that initializes the
1316 frames type is subtly different. The latter only updates ->type
1317 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1318 get_prev_frame() overriding the frame's type when the INIT code
1319 has previously set it. This is really somewhat bogus. The
1320 initialization, as seen in create_new_frame(), should occur
1321 before the INIT function has been called. */
1322 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1323 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1324 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1325 : pc_in_dummy_frame (prev
->pc
)))
1326 prev
->type
= DUMMY_FRAME
;
1329 /* FIXME: cagney/2002-11-10: This should be moved to before the
1330 INIT code above so that the INIT code knows what the frame's
1331 type is (in fact, for a [generic] dummy-frame, the type can
1332 be set and then the entire initialization can be skipped.
1333 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1336 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1337 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1338 prev
->type
= SIGTRAMP_FRAME
;
1339 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1340 architectures are forcing the frame's type in INIT so we
1341 don't want to override it here. Remember, NORMAL_FRAME == 0,
1342 so it all works (just :-/). Once this initialization is
1343 moved to the start of this function, all this nastness will
1350 /* Return a structure containing various interesting information
1351 about the frame that called THIS_FRAME. Returns NULL
1352 if there is no such frame. */
1355 get_prev_frame (struct frame_info
*this_frame
)
1357 struct frame_info
*prev_frame
;
1359 /* Return the inner-most frame, when the caller passes in NULL. */
1360 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1361 caller should have previously obtained a valid frame using
1362 get_selected_frame() and then called this code - only possibility
1363 I can think of is code behaving badly.
1365 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1366 block_innermost_frame(). It does the sequence: frame = NULL;
1367 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1368 it couldn't be written better, I don't know.
1370 NOTE: cagney/2003-01-11: I suspect what is happening is
1371 block_innermost_frame() is, when the target has no state
1372 (registers, memory, ...), still calling this function. The
1373 assumption being that this function will return NULL indicating
1374 that a frame isn't possible, rather than checking that the target
1375 has state and then calling get_current_frame() and
1376 get_prev_frame(). This is a guess mind. */
1377 if (this_frame
== NULL
)
1379 /* NOTE: cagney/2002-11-09: There was a code segment here that
1380 would error out when CURRENT_FRAME was NULL. The comment
1381 that went with it made the claim ...
1383 ``This screws value_of_variable, which just wants a nice
1384 clean NULL return from block_innermost_frame if there are no
1385 frames. I don't think I've ever seen this message happen
1386 otherwise. And returning NULL here is a perfectly legitimate
1389 Per the above, this code shouldn't even be called with a NULL
1391 return current_frame
;
1394 /* There is always a frame. If this assertion fails, suspect that
1395 something should be calling get_selected_frame() or
1396 get_current_frame(). */
1397 gdb_assert (this_frame
!= NULL
);
1399 if (this_frame
->level
>= 0
1400 && !backtrace_below_main
1401 && inside_main_func (get_frame_pc (this_frame
)))
1402 /* Don't unwind past main(), bug always unwind the sentinel frame.
1403 Note, this is done _before_ the frame has been marked as
1404 previously unwound. That way if the user later decides to
1405 allow unwinds past main(), that just happens. */
1408 fprintf_unfiltered (gdb_stdlog
,
1409 "Outermost frame - inside main func.\n");
1413 /* Only try to do the unwind once. */
1414 if (this_frame
->prev_p
)
1415 return this_frame
->prev
;
1416 this_frame
->prev_p
= 1;
1418 /* If we're inside the entry file, it isn't valid. Don't apply this
1419 test to a dummy frame - dummy frame PC's typically land in the
1420 entry file. Don't apply this test to the sentinel frame.
1421 Sentinel frames should always be allowed to unwind. */
1422 /* NOTE: drow/2002-12-25: should there be a way to disable this
1423 check? It assumes a single small entry file, and the way some
1424 debug readers (e.g. dbxread) figure out which object is the
1425 entry file is somewhat hokey. */
1426 /* NOTE: cagney/2003-01-10: If there is a way of disabling this test
1427 then it should probably be moved to before the ->prev_p test,
1429 if (this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1430 && inside_entry_file (get_frame_pc (this_frame
)))
1433 fprintf_unfiltered (gdb_stdlog
,
1434 "Outermost frame - inside entry file\n");
1438 /* If we're already inside the entry function for the main objfile,
1439 then it isn't valid. Don't apply this test to a dummy frame -
1440 dummy frame PC's typically land in the entry func. Don't apply
1441 this test to the sentinel frame. Sentinel frames should always
1442 be allowed to unwind. */
1443 /* NOTE: cagney/2003-02-25: Don't enable until someone has found
1444 hard evidence that this is needed. */
1446 && this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1447 && inside_entry_func (get_frame_pc (this_frame
)))
1450 fprintf_unfiltered (gdb_stdlog
,
1451 "Outermost frame - inside entry func\n");
1455 /* If any of the old frame initialization methods are around, use
1456 the legacy get_prev_frame method. */
1457 if (legacy_frame_p (current_gdbarch
))
1459 prev_frame
= legacy_get_prev_frame (this_frame
);
1460 if (frame_debug
&& prev_frame
== NULL
)
1461 fprintf_unfiltered (gdb_stdlog
,
1462 "Outermost frame - legacy_get_prev_frame NULL.\n");
1466 /* Allocate the new frame but do not wire it in to the frame chain.
1467 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1468 frame->next to pull some fancy tricks (of course such code is, by
1469 definition, recursive). Try to prevent it.
1471 There is no reason to worry about memory leaks, should the
1472 remainder of the function fail. The allocated memory will be
1473 quickly reclaimed when the frame cache is flushed, and the `we've
1474 been here before' check above will stop repeated memory
1475 allocation calls. */
1476 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1477 prev_frame
->level
= this_frame
->level
+ 1;
1479 /* Try to unwind the PC. If that doesn't work, assume we've reached
1480 the oldest frame and simply return. Is there a better sentinal
1481 value? The unwound PC value is then used to initialize the new
1482 previous frame's type.
1484 Note that the pc-unwind is intentionally performed before the
1485 frame chain. This is ok since, for old targets, both
1486 frame_pc_unwind (nee, FRAME_SAVED_PC) and FRAME_CHAIN()) assume
1487 THIS_FRAME's data structures have already been initialized (using
1488 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1491 By unwinding the PC first, it becomes possible to, in the case of
1492 a dummy frame, avoid also unwinding the frame ID. This is
1493 because (well ignoring the PPC) a dummy frame can be located
1494 using THIS_FRAME's frame ID. */
1496 prev_frame
->pc
= frame_pc_unwind (this_frame
);
1497 if (prev_frame
->pc
== 0)
1499 /* The allocated PREV_FRAME will be reclaimed when the frame
1500 obstack is next purged. */
1502 fprintf_unfiltered (gdb_stdlog
,
1503 "Outermost frame - unwound PC zero\n");
1506 prev_frame
->type
= frame_type_from_pc (prev_frame
->pc
);
1508 /* Set the unwind functions based on that identified PC. */
1509 prev_frame
->unwind
= frame_unwind_find_by_pc (current_gdbarch
,
1512 /* Find the prev's frame's ID. */
1514 /* The callee expects to be invoked with:
1516 this->unwind->this_id (this->next, &this->cache, &this->id);
1518 The below is carefully shifted one frame `to the left' so that
1519 both the unwind->this_id and unwind->prev_register methods are
1520 consistently invoked with NEXT_FRAME and THIS_PROLOGUE_CACHE.
1522 Also note that, while the PC for this new previous frame was
1523 unwound first (see above), the below is the first call that
1524 [potentially] requires analysis of the new previous frame's
1525 prologue. Consequently, it is this call, that typically ends up
1526 initializing the previous frame's prologue cache. */
1527 prev_frame
->unwind
->this_id (this_frame
,
1528 &prev_frame
->prologue_cache
,
1531 /* Check that the unwound ID is valid. */
1532 if (!frame_id_p (prev_frame
->id
))
1535 fprintf_unfiltered (gdb_stdlog
,
1536 "Outermost frame - unwound frame ID invalid\n");
1540 /* Check that the new frame isn't inner to (younger, below, next)
1541 the old frame. If that happens the frame unwind is going
1543 /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since that
1544 doesn't have a valid frame ID. Should instead set the sentinel
1545 frame's frame ID to a true `sentinel'. Leave it until after the
1546 switch to storing the frame ID, instead of the frame base, in the
1548 if (this_frame
->level
>= 0
1549 && frame_id_inner (prev_frame
->id
, get_frame_id (this_frame
)))
1550 error ("Unwound frame inner-to selected frame (corrupt stack?)");
1552 /* FIXME: cagney/2003-03-14: Should check that this and next frame's
1553 IDs are different (i.e., !frame_id_eq()). Can't yet do that as
1554 the EQ function doesn't yet compare PC values. */
1556 /* FIXME: cagney/2003-03-14: Should delay the evaluation of the
1557 frame ID until when it is needed. That way the inner most frame
1558 can be created without needing to do prologue analysis. */
1560 /* Note that, due to frameless functions, the stronger test of the
1561 new frame being outer to the old frame can't be used - frameless
1562 functions differ by only their PC value. */
1564 /* FIXME: cagney/2002-12-18: Instead of this hack, should only store
1565 the frame ID in PREV_FRAME. Unfortunatly, some architectures
1566 (HP/UX) still reply on EXTRA_FRAME_INFO and, hence, still poke at
1567 the "struct frame_info" object directly. */
1568 prev_frame
->frame
= prev_frame
->id
.base
;
1571 this_frame
->prev
= prev_frame
;
1572 prev_frame
->next
= this_frame
;
1578 get_frame_pc (struct frame_info
*frame
)
1584 pc_notcurrent (struct frame_info
*frame
)
1586 /* If FRAME is not the innermost frame, that normally means that
1587 FRAME->pc points at the return instruction (which is *after* the
1588 call instruction), and we want to get the line containing the
1589 call (because the call is where the user thinks the program is).
1590 However, if the next frame is either a SIGTRAMP_FRAME or a
1591 DUMMY_FRAME, then the next frame will contain a saved interrupt
1592 PC and such a PC indicates the current (rather than next)
1593 instruction/line, consequently, for such cases, want to get the
1594 line containing fi->pc. */
1595 struct frame_info
*next
= get_next_frame (frame
);
1596 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1601 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1603 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1606 /* Per "frame.h", return the ``address'' of the frame. Code should
1607 really be using get_frame_id(). */
1609 get_frame_base (struct frame_info
*fi
)
1614 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1615 or -1 for a NULL frame. */
1618 frame_relative_level (struct frame_info
*fi
)
1627 get_frame_type (struct frame_info
*frame
)
1629 /* Some targets still don't use [generic] dummy frames. Catch them
1631 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1632 && deprecated_frame_in_dummy (frame
))
1638 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1640 /* Arrrg! See comment in "frame.h". */
1644 #ifdef FRAME_FIND_SAVED_REGS
1645 /* XXX - deprecated. This is a compatibility function for targets
1646 that do not yet implement DEPRECATED_FRAME_INIT_SAVED_REGS. */
1647 /* Find the addresses in which registers are saved in FRAME. */
1650 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1651 struct frame_saved_regs
*saved_regs_addr
)
1653 if (frame
->saved_regs
== NULL
)
1655 frame
->saved_regs
= (CORE_ADDR
*)
1656 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
1658 if (saved_regs_addr
== NULL
)
1660 struct frame_saved_regs saved_regs
;
1661 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1662 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1666 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1667 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1672 struct frame_extra_info
*
1673 get_frame_extra_info (struct frame_info
*fi
)
1675 return fi
->extra_info
;
1678 struct frame_extra_info
*
1679 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1681 fi
->extra_info
= frame_obstack_zalloc (size
);
1682 return fi
->extra_info
;
1686 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
1688 /* See comment in "frame.h". */
1690 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
1691 maintaining a locally allocated frame object. Since such frame's
1692 are not in the frame chain, it isn't possible to assume that the
1693 frame has a next. Sigh. */
1694 if (frame
->next
!= NULL
)
1696 /* While we're at it, update this frame's cached PC value, found
1697 in the next frame. Oh for the day when "struct frame_info"
1698 is opaque and this hack on hack can just go away. */
1699 frame
->next
->pc_unwind_cache
= pc
;
1700 frame
->next
->pc_unwind_cache_p
= 1;
1705 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
1707 /* See comment in "frame.h". */
1708 frame
->frame
= base
;
1712 deprecated_set_frame_saved_regs_hack (struct frame_info
*frame
,
1713 CORE_ADDR
*saved_regs
)
1715 frame
->saved_regs
= saved_regs
;
1719 deprecated_set_frame_extra_info_hack (struct frame_info
*frame
,
1720 struct frame_extra_info
*extra_info
)
1722 frame
->extra_info
= extra_info
;
1726 deprecated_set_frame_next_hack (struct frame_info
*fi
,
1727 struct frame_info
*next
)
1733 deprecated_set_frame_prev_hack (struct frame_info
*fi
,
1734 struct frame_info
*prev
)
1740 deprecated_get_frame_context (struct frame_info
*fi
)
1746 deprecated_set_frame_context (struct frame_info
*fi
,
1747 struct context
*context
)
1749 fi
->context
= context
;
1753 deprecated_frame_xmalloc (void)
1755 struct frame_info
*frame
= XMALLOC (struct frame_info
);
1756 memset (frame
, 0, sizeof (struct frame_info
));
1761 deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs
,
1762 long sizeof_extra_info
)
1764 struct frame_info
*frame
= deprecated_frame_xmalloc ();
1765 make_cleanup (xfree
, frame
);
1766 if (sizeof_saved_regs
> 0)
1768 frame
->saved_regs
= xcalloc (1, sizeof_saved_regs
);
1769 make_cleanup (xfree
, frame
->saved_regs
);
1771 if (sizeof_extra_info
> 0)
1773 frame
->extra_info
= xcalloc (1, sizeof_extra_info
);
1774 make_cleanup (xfree
, frame
->extra_info
);
1780 legacy_frame_p (struct gdbarch
*current_gdbarch
)
1782 return (DEPRECATED_INIT_FRAME_PC_P ()
1783 || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
1784 || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
1786 || !gdbarch_unwind_dummy_id_p (current_gdbarch
)
1787 || !SAVE_DUMMY_FRAME_TOS_P ());
1791 _initialize_frame (void)
1793 obstack_init (&frame_cache_obstack
);
1795 /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest
1796 `set backtrace {past,beyond,...}-main'. Also suggest adding `set
1797 backtrace ...-start' to control backtraces past start. The
1798 problem with `below' is that it stops the `up' command. */
1800 add_setshow_boolean_cmd ("backtrace-below-main", class_obscure
,
1801 &backtrace_below_main
, "\
1802 Set whether backtraces should continue past \"main\".\n\
1803 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1804 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1805 of the stack trace.", "\
1806 Show whether backtraces should continue past \"main\".\n\
1807 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1808 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1809 of the stack trace.",
1810 NULL
, NULL
, &setlist
, &showlist
);
1813 /* Debug this files internals. */
1814 add_show_from_set (add_set_cmd ("frame", class_maintenance
, var_zinteger
,
1815 &frame_debug
, "Set frame debugging.\n\
1816 When non-zero, frame specific internal debugging is enabled.", &setdebuglist
),