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"
38 /* Return a frame uniq ID that can be used to, later, re-find the
42 get_frame_id (struct frame_info
*fi
)
57 const struct frame_id null_frame_id
; /* All zeros. */
60 frame_id_build (CORE_ADDR base
, CORE_ADDR func_or_pc
)
69 frame_id_p (struct frame_id l
)
71 /* The .func can be NULL but the .base cannot. */
76 frame_id_eq (struct frame_id l
, struct frame_id r
)
78 /* If .base is different, the frames are different. */
81 /* Add a test to check that the frame ID's are for the same function
87 frame_id_inner (struct frame_id l
, struct frame_id r
)
89 /* Only return non-zero when strictly inner than. Note that, per
90 comment in "frame.h", there is some fuzz here. Frameless
91 functions are not strictly inner than (same .base but different
93 return INNER_THAN (l
.base
, r
.base
);
97 frame_find_by_id (struct frame_id id
)
99 struct frame_info
*frame
;
101 /* ZERO denotes the null frame, let the caller decide what to do
102 about it. Should it instead return get_current_frame()? */
103 if (!frame_id_p (id
))
106 for (frame
= get_current_frame ();
108 frame
= get_prev_frame (frame
))
110 struct frame_id
this = get_frame_id (frame
);
111 if (frame_id_eq (id
, this))
112 /* An exact match. */
114 if (frame_id_inner (id
, this))
117 /* Either, we're not yet gone far enough out along the frame
118 chain (inner(this,id), or we're comparing frameless functions
119 (same .base, different .func, no test available). Struggle
120 on until we've definitly gone to far. */
126 frame_pc_unwind (struct frame_info
*frame
)
128 if (!frame
->pc_unwind_cache_p
)
130 frame
->pc_unwind_cache
= frame
->pc_unwind (frame
, &frame
->unwind_cache
);
131 frame
->pc_unwind_cache_p
= 1;
133 return frame
->pc_unwind_cache
;
137 frame_id_unwind (struct frame_info
*frame
)
139 if (!frame
->id_unwind_cache_p
)
141 frame
->id_unwind_cache
=
142 frame
->id_unwind (frame
, &frame
->unwind_cache
);
143 frame
->id_unwind_cache_p
= 1;
145 return frame
->id_unwind_cache
;
150 frame_register_unwind (struct frame_info
*frame
, int regnum
,
151 int *optimizedp
, enum lval_type
*lvalp
,
152 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
154 struct frame_unwind_cache
*cache
;
156 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
157 that the value proper does not need to be fetched. */
158 gdb_assert (optimizedp
!= NULL
);
159 gdb_assert (lvalp
!= NULL
);
160 gdb_assert (addrp
!= NULL
);
161 gdb_assert (realnump
!= NULL
);
162 /* gdb_assert (bufferp != NULL); */
164 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
165 special case, there was always an inner frame dedicated to the
166 hardware registers. Unfortunatly, there is too much unwind code
167 around that looks up/down the frame chain while making the
168 assumption that each frame level is using the same unwind code. */
172 /* We're in the inner-most frame, get the value direct from the
175 *lvalp
= lval_register
;
176 /* ULGH! Code uses the offset into the raw register byte array
177 as a way of identifying a register. */
178 *addrp
= REGISTER_BYTE (regnum
);
179 /* Should this code test ``register_cached (regnum) < 0'' and do
180 something like set realnum to -1 when the register isn't
184 deprecated_read_register_gen (regnum
, bufferp
);
188 /* Ask this frame to unwind its register. */
189 frame
->register_unwind (frame
, &frame
->unwind_cache
, regnum
,
190 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
194 frame_register (struct frame_info
*frame
, int regnum
,
195 int *optimizedp
, enum lval_type
*lvalp
,
196 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
198 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
199 that the value proper does not need to be fetched. */
200 gdb_assert (optimizedp
!= NULL
);
201 gdb_assert (lvalp
!= NULL
);
202 gdb_assert (addrp
!= NULL
);
203 gdb_assert (realnump
!= NULL
);
204 /* gdb_assert (bufferp != NULL); */
206 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
207 of the register in the register cache. It should instead return
208 the REGNUM corresponding to that register. Translate the . */
209 if (GET_SAVED_REGISTER_P ())
211 GET_SAVED_REGISTER (bufferp
, optimizedp
, addrp
, frame
, regnum
, lvalp
);
212 /* Compute the REALNUM if the caller wants it. */
213 if (*lvalp
== lval_register
)
216 for (regnum
= 0; regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
; regnum
++)
218 if (*addrp
== register_offset_hack (current_gdbarch
, regnum
))
224 internal_error (__FILE__
, __LINE__
,
225 "Failed to compute the register number corresponding"
226 " to 0x%s", paddr_d (*addrp
));
232 /* Reached the the bottom (youngest, inner most) of the frame chain
233 (youngest, inner most) frame, go direct to the hardware register
234 cache (do not pass go, do not try to cache the value, ...). The
235 unwound value would have been cached in frame->next but that
236 doesn't exist. This doesn't matter as the hardware register
237 cache is stopping any unnecessary accesses to the target. */
239 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
240 special case, there was always an inner frame dedicated to the
241 hardware registers. Unfortunatly, there is too much unwind code
242 around that looks up/down the frame chain while making the
243 assumption that each frame level is using the same unwind code. */
246 frame_register_unwind (NULL
, regnum
, optimizedp
, lvalp
, addrp
, realnump
,
249 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
254 frame_unwind_signed_register (struct frame_info
*frame
, int regnum
,
261 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
262 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
264 (*val
) = extract_signed_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
268 frame_unwind_unsigned_register (struct frame_info
*frame
, int regnum
,
275 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
276 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
278 (*val
) = extract_unsigned_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
282 frame_read_unsigned_register (struct frame_info
*frame
, int regnum
,
285 /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is
286 always a frame. Both this, and the equivalent
287 frame_read_signed_register() function, can only be called with a
288 valid frame. If, for some reason, this function is called
289 without a frame then the problem isn't here, but rather in the
290 caller. It should of first created a frame and then passed that
292 /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the
293 ``current_frame'' should not be treated as a special case. While
294 ``get_next_frame (current_frame) == NULL'' currently holds, it
295 should, as far as possible, not be relied upon. In the future,
296 ``get_next_frame (current_frame)'' may instead simply return a
297 normal frame object that simply always gets register values from
298 the register cache. Consequently, frame code should try to avoid
299 tests like ``if get_next_frame() == NULL'' and instead just rely
300 on recursive frame calls (like the below code) when manipulating
302 gdb_assert (frame
!= NULL
);
303 frame_unwind_unsigned_register (get_next_frame (frame
), regnum
, val
);
307 frame_read_signed_register (struct frame_info
*frame
, int regnum
,
310 /* See note in frame_read_unsigned_register(). */
311 gdb_assert (frame
!= NULL
);
312 frame_unwind_signed_register (get_next_frame (frame
), regnum
, val
);
316 generic_unwind_get_saved_register (char *raw_buffer
,
319 struct frame_info
*frame
,
321 enum lval_type
*lvalp
)
326 enum lval_type lvalx
;
328 if (!target_has_registers
)
329 error ("No registers.");
331 /* Keep things simple, ensure that all the pointers (except valuep)
333 if (optimizedp
== NULL
)
334 optimizedp
= &optimizedx
;
340 /* Reached the the bottom (youngest, inner most) of the frame chain
341 (youngest, inner most) frame, go direct to the hardware register
342 cache (do not pass go, do not try to cache the value, ...). The
343 unwound value would have been cached in frame->next but that
344 doesn't exist. This doesn't matter as the hardware register
345 cache is stopping any unnecessary accesses to the target. */
347 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
348 special case, there was always an inner frame dedicated to the
349 hardware registers. Unfortunatly, there is too much unwind code
350 around that looks up/down the frame chain while making the
351 assumption that each frame level is using the same unwind code. */
354 frame_register_unwind (NULL
, regnum
, optimizedp
, lvalp
, addrp
, &realnumx
,
357 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
358 &realnumx
, raw_buffer
);
362 get_saved_register (char *raw_buffer
,
365 struct frame_info
*frame
,
367 enum lval_type
*lval
)
369 if (GET_SAVED_REGISTER_P ())
371 GET_SAVED_REGISTER (raw_buffer
, optimized
, addrp
, frame
, regnum
, lval
);
374 generic_unwind_get_saved_register (raw_buffer
, optimized
, addrp
, frame
,
378 /* frame_register_read ()
380 Find and return the value of REGNUM for the specified stack frame.
381 The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
383 Returns 0 if the register value could not be found. */
386 frame_register_read (struct frame_info
*frame
, int regnum
, void *myaddr
)
392 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
394 /* FIXME: cagney/2002-05-15: This test, is just bogus.
396 It indicates that the target failed to supply a value for a
397 register because it was "not available" at this time. Problem
398 is, the target still has the register and so get saved_register()
399 may be returning a value saved on the stack. */
401 if (register_cached (regnum
) < 0)
402 return 0; /* register value not available */
408 /* Map between a frame register number and its name. A frame register
409 space is a superset of the cooked register space --- it also
410 includes builtin registers. */
413 frame_map_name_to_regnum (const char *name
, int len
)
417 /* Search register name space. */
418 for (i
= 0; i
< NUM_REGS
+ NUM_PSEUDO_REGS
; i
++)
419 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
420 && strncmp (name
, REGISTER_NAME (i
), len
) == 0)
425 /* Try builtin registers. */
426 i
= builtin_reg_map_name_to_regnum (name
, len
);
429 /* A builtin register doesn't fall into the architecture's
431 gdb_assert (i
>= NUM_REGS
+ NUM_PSEUDO_REGS
);
439 frame_map_regnum_to_name (int regnum
)
443 if (regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
)
444 return REGISTER_NAME (regnum
);
445 return builtin_reg_map_regnum_to_name (regnum
);
448 /* Info about the innermost stack frame (contents of FP register) */
450 static struct frame_info
*current_frame
;
452 /* Cache for frame addresses already read by gdb. Valid only while
453 inferior is stopped. Control variables for the frame cache should
454 be local to this module. */
456 static struct obstack frame_cache_obstack
;
459 frame_obstack_alloc (unsigned long size
)
461 return obstack_alloc (&frame_cache_obstack
, size
);
465 frame_saved_regs_zalloc (struct frame_info
*fi
)
467 fi
->saved_regs
= (CORE_ADDR
*)
468 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
469 memset (fi
->saved_regs
, 0, SIZEOF_FRAME_SAVED_REGS
);
470 return fi
->saved_regs
;
474 get_frame_saved_regs (struct frame_info
*fi
)
476 return fi
->saved_regs
;
479 /* Return the innermost (currently executing) stack frame. */
482 get_current_frame (void)
484 if (current_frame
== NULL
)
486 if (target_has_stack
)
487 current_frame
= create_new_frame (read_fp (), read_pc ());
491 return current_frame
;
494 /* The "selected" stack frame is used by default for local and arg
495 access. May be zero, for no selected frame. */
497 struct frame_info
*deprecated_selected_frame
;
499 /* Return the selected frame. Always non-null (unless there isn't an
500 inferior sufficient for creating a frame) in which case an error is
504 get_selected_frame (void)
506 if (deprecated_selected_frame
== NULL
)
507 /* Hey! Don't trust this. It should really be re-finding the
508 last selected frame of the currently selected thread. This,
509 though, is better than nothing. */
510 select_frame (get_current_frame ());
511 /* There is always a frame. */
512 gdb_assert (deprecated_selected_frame
!= NULL
);
513 return deprecated_selected_frame
;
516 /* Select frame FI (or NULL - to invalidate the current frame). */
519 select_frame (struct frame_info
*fi
)
521 register struct symtab
*s
;
523 deprecated_selected_frame
= fi
;
524 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
525 frame is being invalidated. */
526 if (selected_frame_level_changed_hook
)
527 selected_frame_level_changed_hook (frame_relative_level (fi
));
529 /* FIXME: kseitz/2002-08-28: It would be nice to call
530 selected_frame_level_changed_event right here, but due to limitations
531 in the current interfaces, we would end up flooding UIs with events
532 because select_frame is used extensively internally.
534 Once we have frame-parameterized frame (and frame-related) commands,
535 the event notification can be moved here, since this function will only
536 be called when the users selected frame is being changed. */
538 /* Ensure that symbols for this frame are read in. Also, determine the
539 source language of this frame, and switch to it if desired. */
542 s
= find_pc_symtab (fi
->pc
);
544 && s
->language
!= current_language
->la_language
545 && s
->language
!= language_unknown
546 && language_mode
== language_mode_auto
)
548 set_language (s
->language
);
553 /* Return the register saved in the simplistic ``saved_regs'' cache.
554 If the value isn't here AND a value is needed, try the next inner
558 frame_saved_regs_register_unwind (struct frame_info
*frame
, void **cache
,
559 int regnum
, int *optimizedp
,
560 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
561 int *realnump
, void *bufferp
)
563 /* There is always a frame at this point. And THIS is the frame
564 we're interested in. */
565 gdb_assert (frame
!= NULL
);
566 /* If we're using generic dummy frames, we'd better not be in a call
567 dummy. (generic_call_dummy_register_unwind ought to have been called
569 gdb_assert (!(DEPRECATED_USE_GENERIC_DUMMY_FRAMES
570 && (get_frame_type (frame
) == DUMMY_FRAME
)));
572 /* Load the saved_regs register cache. */
573 if (frame
->saved_regs
== NULL
)
574 FRAME_INIT_SAVED_REGS (frame
);
576 if (frame
->saved_regs
!= NULL
577 && frame
->saved_regs
[regnum
] != 0)
579 if (regnum
== SP_REGNUM
)
581 /* SP register treated specially. */
587 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
588 frame
->saved_regs
[regnum
]);
592 /* Any other register is saved in memory, fetch it but cache
593 a local copy of its value. */
595 *lvalp
= lval_memory
;
596 *addrp
= frame
->saved_regs
[regnum
];
601 /* Save each register value, as it is read in, in a
602 frame based cache. */
603 void **regs
= (*cache
);
606 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
608 regs
= frame_obstack_alloc (sizeof_cache
);
609 memset (regs
, 0, sizeof_cache
);
612 if (regs
[regnum
] == NULL
)
615 = frame_obstack_alloc (REGISTER_RAW_SIZE (regnum
));
616 read_memory (frame
->saved_regs
[regnum
], regs
[regnum
],
617 REGISTER_RAW_SIZE (regnum
));
619 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
621 /* Read the value in from memory. */
622 read_memory (frame
->saved_regs
[regnum
], bufferp
,
623 REGISTER_RAW_SIZE (regnum
));
630 /* No luck, assume this and the next frame have the same register
631 value. If a value is needed, pass the request on down the chain;
632 otherwise just return an indication that the value is in the same
633 register as the next frame. */
637 *lvalp
= lval_register
;
643 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
649 frame_saved_regs_pc_unwind (struct frame_info
*frame
, void **cache
)
651 return FRAME_SAVED_PC (frame
);
654 static struct frame_id
655 frame_saved_regs_id_unwind (struct frame_info
*next_frame
, void **cache
)
660 if (next_frame
->next
== NULL
)
661 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
662 the frame chain, not just the inner most frame! The generic,
663 per-architecture, frame code should handle this and the below
664 should simply be removed. */
665 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
670 /* A frameless inner-most frame. The `FP' (which isn't an
671 architecture frame-pointer register!) of the caller is the same
673 /* FIXME: 2002-11-09: There isn't any reason to special case this
674 edge condition. Instead the per-architecture code should hande
676 id
.base
= get_frame_base (next_frame
);
679 /* Two macros defined in tm.h specify the machine-dependent
680 actions to be performed here.
682 First, get the frame's chain-pointer.
684 If that is zero, the frame is the outermost frame or a leaf
685 called by the outermost frame. This means that if start
686 calls main without a frame, we'll return 0 (which is fine
689 Nope; there's a problem. This also returns when the current
690 routine is a leaf of main. This is unacceptable. We move
691 this to after the ffi test; I'd rather have backtraces from
692 start go curfluy than have an abort called from main not show
694 id
.base
= FRAME_CHAIN (next_frame
);
696 if (!frame_chain_valid (id
.base
, next_frame
))
697 return null_frame_id
;
700 return null_frame_id
;
702 /* FIXME: cagney/2002-06-08: This should probably return the frame's
703 function and not the PC (a.k.a. resume address). */
704 id
.pc
= frame_pc_unwind (next_frame
);
708 /* Function: get_saved_register
709 Find register number REGNUM relative to FRAME and put its (raw,
710 target format) contents in *RAW_BUFFER.
712 Set *OPTIMIZED if the variable was optimized out (and thus can't be
713 fetched). Note that this is never set to anything other than zero
714 in this implementation.
716 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
717 whether the value was fetched from memory, from a register, or in a
718 strange and non-modifiable way (e.g. a frame pointer which was
719 calculated rather than fetched). We will use not_lval for values
720 fetched from generic dummy frames.
722 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
723 offset into the registers array. If the value is stored in a dummy
724 frame, set *ADDRP to zero.
726 To use this implementation, define a function called
727 "get_saved_register" in your target code, which simply passes all
728 of its arguments to this function.
730 The argument RAW_BUFFER must point to aligned memory. */
733 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
735 struct frame_info
*frame
, int regnum
,
736 enum lval_type
*lval
)
738 if (!target_has_registers
)
739 error ("No registers.");
741 /* Normal systems don't optimize out things with register numbers. */
742 if (optimized
!= NULL
)
745 if (addrp
) /* default assumption: not found in memory */
748 /* Note: since the current frame's registers could only have been
749 saved by frames INTERIOR TO the current frame, we skip examining
750 the current frame itself: otherwise, we would be getting the
751 previous frame's registers which were saved by the current frame. */
753 while (frame
&& ((frame
= frame
->next
) != NULL
))
755 if (get_frame_type (frame
) == DUMMY_FRAME
)
757 if (lval
) /* found it in a CALL_DUMMY frame */
760 /* FIXME: cagney/2002-06-26: This should be via the
761 gdbarch_register_read() method so that it, on the fly,
762 constructs either a raw or pseudo register from the raw
764 regcache_raw_read (generic_find_dummy_frame (frame
->pc
,
770 FRAME_INIT_SAVED_REGS (frame
);
771 if (frame
->saved_regs
!= NULL
772 && frame
->saved_regs
[regnum
] != 0)
774 if (lval
) /* found it saved on the stack */
776 if (regnum
== SP_REGNUM
)
778 if (raw_buffer
) /* SP register treated specially */
779 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
780 frame
->saved_regs
[regnum
]);
784 if (addrp
) /* any other register */
785 *addrp
= frame
->saved_regs
[regnum
];
787 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
788 REGISTER_RAW_SIZE (regnum
));
794 /* If we get thru the loop to this point, it means the register was
795 not saved in any frame. Return the actual live-register value. */
797 if (lval
) /* found it in a live register */
798 *lval
= lval_register
;
800 *addrp
= REGISTER_BYTE (regnum
);
802 deprecated_read_register_gen (regnum
, raw_buffer
);
805 /* Using the PC, select a mechanism for unwinding a frame returning
806 the previous frame. The register unwind function should, on
807 demand, initialize the ->context object. */
810 set_unwind_by_pc (CORE_ADDR pc
, CORE_ADDR fp
,
811 frame_register_unwind_ftype
**unwind_register
,
812 frame_pc_unwind_ftype
**unwind_pc
,
813 frame_id_unwind_ftype
**unwind_id
)
815 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
)
817 /* Still need to set this to something. The ``info frame'' code
818 calls this function to find out where the saved registers are.
819 Hopefully this is robust enough to stop any core dumps and
820 return vaguely correct values.. */
821 *unwind_register
= frame_saved_regs_register_unwind
;
822 *unwind_pc
= frame_saved_regs_pc_unwind
;
823 *unwind_id
= frame_saved_regs_id_unwind
;
825 else if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
826 ? DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0)
827 : pc_in_dummy_frame (pc
))
829 *unwind_register
= dummy_frame_register_unwind
;
830 *unwind_pc
= dummy_frame_pc_unwind
;
831 *unwind_id
= dummy_frame_id_unwind
;
835 *unwind_register
= frame_saved_regs_register_unwind
;
836 *unwind_pc
= frame_saved_regs_pc_unwind
;
837 *unwind_id
= frame_saved_regs_id_unwind
;
841 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
842 Always returns a non-NULL value. */
845 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
847 struct frame_info
*fi
;
848 enum frame_type type
;
850 fi
= (struct frame_info
*)
851 obstack_alloc (&frame_cache_obstack
,
852 sizeof (struct frame_info
));
854 /* Zero all fields by default. */
855 memset (fi
, 0, sizeof (struct frame_info
));
859 /* NOTE: cagney/2002-11-18: The code segments, found in
860 create_new_frame and get_prev_frame(), that initializes the
861 frames type is subtly different. The latter only updates ->type
862 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
863 get_prev_frame() overriding the frame's type when the INIT code
864 has previously set it. This is really somewhat bogus. The
865 initialization, as seen in create_new_frame(), should occur
866 before the INIT function has been called. */
867 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
868 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
869 ? DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0)
870 : pc_in_dummy_frame (pc
)))
871 /* NOTE: cagney/2002-11-11: Does this even occure? */
876 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
877 if (PC_IN_SIGTRAMP (fi
->pc
, name
))
878 type
= SIGTRAMP_FRAME
;
884 if (INIT_EXTRA_FRAME_INFO_P ())
885 INIT_EXTRA_FRAME_INFO (0, fi
);
887 /* Select/initialize an unwind function. */
888 set_unwind_by_pc (fi
->pc
, fi
->frame
, &fi
->register_unwind
,
889 &fi
->pc_unwind
, &fi
->id_unwind
);
894 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
898 get_next_frame (struct frame_info
*frame
)
903 /* Flush the entire frame cache. */
906 flush_cached_frames (void)
908 /* Since we can't really be sure what the first object allocated was */
909 obstack_free (&frame_cache_obstack
, 0);
910 obstack_init (&frame_cache_obstack
);
912 current_frame
= NULL
; /* Invalidate cache */
914 annotate_frames_invalid ();
917 /* Flush the frame cache, and start a new one if necessary. */
920 reinit_frame_cache (void)
922 flush_cached_frames ();
924 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
925 if (PIDGET (inferior_ptid
) != 0)
927 select_frame (get_current_frame ());
931 /* Return a structure containing various interesting information
932 about the frame that called NEXT_FRAME. Returns NULL
933 if there is no such frame. */
936 get_prev_frame (struct frame_info
*next_frame
)
938 CORE_ADDR address
= 0;
939 struct frame_info
*prev
;
942 /* Return the inner-most frame, when the caller passes in NULL. */
943 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
944 caller should have previously obtained a valid frame using
945 get_selected_frame() and then called this code - only possibility
946 I can think of is code behaving badly. */
947 if (next_frame
== NULL
)
949 /* NOTE: cagney/2002-11-09: There was a code segment here that
950 would error out when CURRENT_FRAME was NULL. The comment
951 that went with it made the claim ...
953 ``This screws value_of_variable, which just wants a nice
954 clean NULL return from block_innermost_frame if there are no
955 frames. I don't think I've ever seen this message happen
956 otherwise. And returning NULL here is a perfectly legitimate
959 Per the above, this code shouldn't even be called with a NULL
961 return current_frame
;
964 /* Only try to do the unwind once. */
965 if (next_frame
->prev_p
)
966 return next_frame
->prev
;
967 next_frame
->prev_p
= 1;
969 /* On some machines it is possible to call a function without
970 setting up a stack frame for it. On these machines, we
971 define this macro to take two args; a frameinfo pointer
972 identifying a frame and a variable to set or clear if it is
973 or isn't leafless. */
975 /* Still don't want to worry about this except on the innermost
976 frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
977 function invocation. */
978 if (next_frame
->next
== NULL
)
979 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
980 the frame chain, not just the inner most frame! The generic,
981 per-architecture, frame code should handle this and the below
982 should simply be removed. */
983 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
988 /* A frameless inner-most frame. The `FP' (which isn't an
989 architecture frame-pointer register!) of the caller is the same
991 /* FIXME: 2002-11-09: There isn't any reason to special case this
992 edge condition. Instead the per-architecture code should hande
994 address
= get_frame_base (next_frame
);
997 /* Two macros defined in tm.h specify the machine-dependent
998 actions to be performed here.
1000 First, get the frame's chain-pointer.
1002 If that is zero, the frame is the outermost frame or a leaf
1003 called by the outermost frame. This means that if start
1004 calls main without a frame, we'll return 0 (which is fine
1007 Nope; there's a problem. This also returns when the current
1008 routine is a leaf of main. This is unacceptable. We move
1009 this to after the ffi test; I'd rather have backtraces from
1010 start go curfluy than have an abort called from main not show
1012 address
= FRAME_CHAIN (next_frame
);
1014 if (!frame_chain_valid (address
, next_frame
))
1020 /* Create an initially zero previous frame. */
1021 prev
= (struct frame_info
*)
1022 obstack_alloc (&frame_cache_obstack
,
1023 sizeof (struct frame_info
));
1024 memset (prev
, 0, sizeof (struct frame_info
));
1027 next_frame
->prev
= prev
;
1028 prev
->next
= next_frame
;
1029 prev
->frame
= address
;
1030 prev
->level
= next_frame
->level
+ 1;
1031 /* FIXME: cagney/2002-11-18: Should be setting the frame's type
1032 here, before anything else, and not last. Various INIT functions
1033 are full of work-arounds for the frames type not being set
1034 correctly from the word go. Ulgh! */
1035 prev
->type
= NORMAL_FRAME
;
1037 /* This change should not be needed, FIXME! We should determine
1038 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1039 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
1040 express what goes on here.
1042 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
1043 (where the PC is already set up) and here (where it isn't).
1044 DEPRECATED_INIT_FRAME_PC is only called from here, always after
1045 INIT_EXTRA_FRAME_INFO.
1047 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
1048 PC value (which hasn't been set yet). Some other machines appear
1049 to require INIT_EXTRA_FRAME_INFO before they can do
1050 DEPRECATED_INIT_FRAME_PC. Phoo.
1052 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1053 complication to an already overcomplicated part of GDB.
1054 gnu@cygnus.com, 15Sep92.
1056 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1057 INIT_EXTRA_FRAME_INFO, one possible scheme:
1059 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1060 (read_fp ()), read_pc ()). Machines with extra frame info would
1061 do that (or the local equivalent) and then set the extra fields.
1063 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1064 create_new_frame would no longer init extra frame info;
1065 SETUP_ARBITRARY_FRAME would have to do that.
1067 INIT_PREV_FRAME(fromleaf, prev) Replace INIT_EXTRA_FRAME_INFO and
1068 DEPRECATED_INIT_FRAME_PC. This should also return a flag saying
1069 whether to keep the new frame, or whether to discard it, because
1070 on some machines (e.g. mips) it is really awkward to have
1071 FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
1072 no good way to get information deduced in FRAME_CHAIN_VALID into
1073 the extra fields of the new frame). std_frame_pc(fromleaf, prev)
1075 This is the default setting for INIT_PREV_FRAME. It just does
1076 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1077 will call it from INIT_PREV_FRAME (either at the beginning, the
1078 end, or in the middle). Some machines won't use it.
1080 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1082 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1083 reason for things to be this complicated.
1085 The trick is to assume that there is always a frame. Instead of
1086 special casing the inner-most frame, create fake frame
1087 (containing the hardware registers) that is inner to the
1088 user-visible inner-most frame (...) and then unwind from that.
1089 That way architecture code can use use the standard
1090 frame_XX_unwind() functions and not differentiate between the
1091 inner most and any other case.
1093 Since there is always a frame to unwind from, there is always
1094 somewhere (NEXT_FRAME) to store all the info needed to construct
1095 a new (previous) frame without having to first create it. This
1096 means that the convolution below - needing to carefully order a
1097 frame's initialization - isn't needed.
1099 The irony here though, is that FRAME_CHAIN(), at least for a more
1100 up-to-date architecture, always calls FRAME_SAVED_PC(), and
1101 FRAME_SAVED_PC() computes the PC but without first needing the
1102 frame! Instead of the convolution below, we could have simply
1103 called FRAME_SAVED_PC() and been done with it! Note that
1104 FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
1105 function does have somewhere to cache that PC value. */
1107 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1108 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1110 if (INIT_EXTRA_FRAME_INFO_P ())
1111 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1113 /* This entry is in the frame queue now, which is good since
1114 FRAME_SAVED_PC may use that queue to figure out its value (see
1115 tm-sparc.h). We want the pc saved in the inferior frame. */
1116 if (DEPRECATED_INIT_FRAME_PC_P ())
1117 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1119 /* If ->frame and ->pc are unchanged, we are in the process of
1120 getting ourselves into an infinite backtrace. Some architectures
1121 check this in FRAME_CHAIN or thereabouts, but it seems like there
1122 is no reason this can't be an architecture-independent check. */
1123 if (prev
->frame
== next_frame
->frame
1124 && prev
->pc
== next_frame
->pc
)
1126 next_frame
->prev
= NULL
;
1127 obstack_free (&frame_cache_obstack
, prev
);
1131 /* Initialize the code used to unwind the frame PREV based on the PC
1132 (and probably other architectural information). The PC lets you
1133 check things like the debug info at that point (dwarf2cfi?) and
1134 use that to decide how the frame should be unwound. */
1135 set_unwind_by_pc (prev
->pc
, prev
->frame
, &prev
->register_unwind
,
1136 &prev
->pc_unwind
, &prev
->id_unwind
);
1138 /* NOTE: cagney/2002-11-18: The code segments, found in
1139 create_new_frame and get_prev_frame(), that initializes the
1140 frames type is subtly different. The latter only updates ->type
1141 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1142 get_prev_frame() overriding the frame's type when the INIT code
1143 has previously set it. This is really somewhat bogus. The
1144 initialization, as seen in create_new_frame(), should occur
1145 before the INIT function has been called. */
1146 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1147 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1148 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1149 : pc_in_dummy_frame (prev
->pc
)))
1150 prev
->type
= DUMMY_FRAME
;
1153 /* FIXME: cagney/2002-11-10: This should be moved to before the
1154 INIT code above so that the INIT code knows what the frame's
1155 type is (in fact, for a [generic] dummy-frame, the type can
1156 be set and then the entire initialization can be skipped.
1157 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1160 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1161 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1162 prev
->type
= SIGTRAMP_FRAME
;
1163 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1164 architectures are forcing the frame's type in INIT so we
1165 don't want to override it here. Remember, NORMAL_FRAME == 0,
1166 so it all works (just :-/). Once this initialization is
1167 moved to the start of this function, all this nastness will
1175 get_frame_pc (struct frame_info
*frame
)
1181 pc_notcurrent (struct frame_info
*frame
)
1183 /* If FRAME is not the innermost frame, that normally means that
1184 FRAME->pc points at the return instruction (which is *after* the
1185 call instruction), and we want to get the line containing the
1186 call (because the call is where the user thinks the program is).
1187 However, if the next frame is either a SIGTRAMP_FRAME or a
1188 DUMMY_FRAME, then the next frame will contain a saved interrupt
1189 PC and such a PC indicates the current (rather than next)
1190 instruction/line, consequently, for such cases, want to get the
1191 line containing fi->pc. */
1192 struct frame_info
*next
= get_next_frame (frame
);
1193 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1198 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1200 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1203 /* Per "frame.h", return the ``address'' of the frame. Code should
1204 really be using get_frame_id(). */
1206 get_frame_base (struct frame_info
*fi
)
1211 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1212 or -1 for a NULL frame. */
1215 frame_relative_level (struct frame_info
*fi
)
1224 get_frame_type (struct frame_info
*frame
)
1226 /* Some targets still don't use [generic] dummy frames. Catch them
1228 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1229 && deprecated_frame_in_dummy (frame
))
1235 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1237 /* Arrrg! See comment in "frame.h". */
1241 #ifdef FRAME_FIND_SAVED_REGS
1242 /* XXX - deprecated. This is a compatibility function for targets
1243 that do not yet implement FRAME_INIT_SAVED_REGS. */
1244 /* Find the addresses in which registers are saved in FRAME. */
1247 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1248 struct frame_saved_regs
*saved_regs_addr
)
1250 if (frame
->saved_regs
== NULL
)
1252 frame
->saved_regs
= (CORE_ADDR
*)
1253 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
1255 if (saved_regs_addr
== NULL
)
1257 struct frame_saved_regs saved_regs
;
1258 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1259 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1263 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1264 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1269 struct frame_extra_info
*
1270 get_frame_extra_info (struct frame_info
*fi
)
1272 return fi
->extra_info
;
1275 struct frame_extra_info
*
1276 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1278 fi
->extra_info
= frame_obstack_alloc (size
);
1279 memset (fi
->extra_info
, 0, size
);
1280 return fi
->extra_info
;
1284 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
1286 /* See comment in "frame.h". */
1291 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
1293 /* See comment in "frame.h". */
1294 frame
->frame
= base
;
1298 deprecated_set_frame_saved_regs_hack (struct frame_info
*frame
,
1299 CORE_ADDR
*saved_regs
)
1301 frame
->saved_regs
= saved_regs
;
1305 deprecated_set_frame_extra_info_hack (struct frame_info
*frame
,
1306 struct frame_extra_info
*extra_info
)
1308 frame
->extra_info
= extra_info
;
1312 deprecated_frame_xmalloc (void)
1314 struct frame_info
*frame
= XMALLOC (struct frame_info
);
1315 memset (frame
, 0, sizeof (struct frame_info
));
1320 deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs
,
1321 long sizeof_extra_info
)
1323 struct frame_info
*frame
= deprecated_frame_xmalloc ();
1324 make_cleanup (xfree
, frame
);
1325 if (sizeof_saved_regs
> 0)
1327 frame
->saved_regs
= xcalloc (1, sizeof_saved_regs
);
1328 make_cleanup (xfree
, frame
->saved_regs
);
1330 if (sizeof_extra_info
> 0)
1332 frame
->extra_info
= xcalloc (1, sizeof_extra_info
);
1333 make_cleanup (xfree
, frame
->extra_info
);
1339 _initialize_frame (void)
1341 obstack_init (&frame_cache_obstack
);