1 /* Cache and manage frames for GDB, the GNU debugger.
3 Copyright 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000,
4 2001, 2002 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 /* FIXME: cagney/2002-06-08: There should be two tests here.
697 The first would check for a valid frame chain based on a user
698 selectable policy. The default being ``stop at main'' (as
699 implemented by generic_func_frame_chain_valid()). Other
700 policies would be available - stop at NULL, .... The second
701 test, if provided by the target architecture, would check for
702 more exotic cases - most target architectures wouldn't bother
703 with this second case. */
704 if (!FRAME_CHAIN_VALID (id
.base
, next_frame
))
705 return null_frame_id
;
708 return null_frame_id
;
710 /* FIXME: cagney/2002-06-08: This should probably return the frame's
711 function and not the PC (a.k.a. resume address). */
712 id
.pc
= frame_pc_unwind (next_frame
);
716 /* Function: get_saved_register
717 Find register number REGNUM relative to FRAME and put its (raw,
718 target format) contents in *RAW_BUFFER.
720 Set *OPTIMIZED if the variable was optimized out (and thus can't be
721 fetched). Note that this is never set to anything other than zero
722 in this implementation.
724 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
725 whether the value was fetched from memory, from a register, or in a
726 strange and non-modifiable way (e.g. a frame pointer which was
727 calculated rather than fetched). We will use not_lval for values
728 fetched from generic dummy frames.
730 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
731 offset into the registers array. If the value is stored in a dummy
732 frame, set *ADDRP to zero.
734 To use this implementation, define a function called
735 "get_saved_register" in your target code, which simply passes all
736 of its arguments to this function.
738 The argument RAW_BUFFER must point to aligned memory. */
741 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
743 struct frame_info
*frame
, int regnum
,
744 enum lval_type
*lval
)
746 if (!target_has_registers
)
747 error ("No registers.");
749 /* Normal systems don't optimize out things with register numbers. */
750 if (optimized
!= NULL
)
753 if (addrp
) /* default assumption: not found in memory */
756 /* Note: since the current frame's registers could only have been
757 saved by frames INTERIOR TO the current frame, we skip examining
758 the current frame itself: otherwise, we would be getting the
759 previous frame's registers which were saved by the current frame. */
761 while (frame
&& ((frame
= frame
->next
) != NULL
))
763 if (get_frame_type (frame
) == DUMMY_FRAME
)
765 if (lval
) /* found it in a CALL_DUMMY frame */
768 /* FIXME: cagney/2002-06-26: This should be via the
769 gdbarch_register_read() method so that it, on the fly,
770 constructs either a raw or pseudo register from the raw
772 regcache_raw_read (generic_find_dummy_frame (frame
->pc
,
778 FRAME_INIT_SAVED_REGS (frame
);
779 if (frame
->saved_regs
!= NULL
780 && frame
->saved_regs
[regnum
] != 0)
782 if (lval
) /* found it saved on the stack */
784 if (regnum
== SP_REGNUM
)
786 if (raw_buffer
) /* SP register treated specially */
787 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
788 frame
->saved_regs
[regnum
]);
792 if (addrp
) /* any other register */
793 *addrp
= frame
->saved_regs
[regnum
];
795 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
796 REGISTER_RAW_SIZE (regnum
));
802 /* If we get thru the loop to this point, it means the register was
803 not saved in any frame. Return the actual live-register value. */
805 if (lval
) /* found it in a live register */
806 *lval
= lval_register
;
808 *addrp
= REGISTER_BYTE (regnum
);
810 deprecated_read_register_gen (regnum
, raw_buffer
);
813 /* Using the PC, select a mechanism for unwinding a frame returning
814 the previous frame. The register unwind function should, on
815 demand, initialize the ->context object. */
818 set_unwind_by_pc (CORE_ADDR pc
, CORE_ADDR fp
,
819 frame_register_unwind_ftype
**unwind_register
,
820 frame_pc_unwind_ftype
**unwind_pc
,
821 frame_id_unwind_ftype
**unwind_id
)
823 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
)
825 /* Still need to set this to something. The ``info frame'' code
826 calls this function to find out where the saved registers are.
827 Hopefully this is robust enough to stop any core dumps and
828 return vaguely correct values.. */
829 *unwind_register
= frame_saved_regs_register_unwind
;
830 *unwind_pc
= frame_saved_regs_pc_unwind
;
831 *unwind_id
= frame_saved_regs_id_unwind
;
833 else if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
834 ? DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0)
835 : pc_in_dummy_frame (pc
))
837 *unwind_register
= dummy_frame_register_unwind
;
838 *unwind_pc
= dummy_frame_pc_unwind
;
839 *unwind_id
= dummy_frame_id_unwind
;
843 *unwind_register
= frame_saved_regs_register_unwind
;
844 *unwind_pc
= frame_saved_regs_pc_unwind
;
845 *unwind_id
= frame_saved_regs_id_unwind
;
849 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
850 Always returns a non-NULL value. */
853 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
855 struct frame_info
*fi
;
856 enum frame_type type
;
858 fi
= (struct frame_info
*)
859 obstack_alloc (&frame_cache_obstack
,
860 sizeof (struct frame_info
));
862 /* Zero all fields by default. */
863 memset (fi
, 0, sizeof (struct frame_info
));
867 /* NOTE: cagney/2002-11-18: The code segments, found in
868 create_new_frame and get_prev_frame(), that initializes the
869 frames type is subtly different. The latter only updates ->type
870 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
871 get_prev_frame() overriding the frame's type when the INIT code
872 has previously set it. This is really somewhat bogus. The
873 initialization, as seen in create_new_frame(), should occur
874 before the INIT function has been called. */
875 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
876 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
877 ? DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0)
878 : pc_in_dummy_frame (pc
)))
879 /* NOTE: cagney/2002-11-11: Does this even occure? */
884 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
885 if (PC_IN_SIGTRAMP (fi
->pc
, name
))
886 type
= SIGTRAMP_FRAME
;
892 if (INIT_EXTRA_FRAME_INFO_P ())
893 INIT_EXTRA_FRAME_INFO (0, fi
);
895 /* Select/initialize an unwind function. */
896 set_unwind_by_pc (fi
->pc
, fi
->frame
, &fi
->register_unwind
,
897 &fi
->pc_unwind
, &fi
->id_unwind
);
902 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
906 get_next_frame (struct frame_info
*frame
)
911 /* Flush the entire frame cache. */
914 flush_cached_frames (void)
916 /* Since we can't really be sure what the first object allocated was */
917 obstack_free (&frame_cache_obstack
, 0);
918 obstack_init (&frame_cache_obstack
);
920 current_frame
= NULL
; /* Invalidate cache */
922 annotate_frames_invalid ();
925 /* Flush the frame cache, and start a new one if necessary. */
928 reinit_frame_cache (void)
930 flush_cached_frames ();
932 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
933 if (PIDGET (inferior_ptid
) != 0)
935 select_frame (get_current_frame ());
939 /* Return a structure containing various interesting information
940 about the frame that called NEXT_FRAME. Returns NULL
941 if there is no such frame. */
944 get_prev_frame (struct frame_info
*next_frame
)
946 CORE_ADDR address
= 0;
947 struct frame_info
*prev
;
950 /* Return the inner-most frame, when the caller passes in NULL. */
951 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
952 caller should have previously obtained a valid frame using
953 get_selected_frame() and then called this code - only possibility
954 I can think of is code behaving badly. */
955 if (next_frame
== NULL
)
957 /* NOTE: cagney/2002-11-09: There was a code segment here that
958 would error out when CURRENT_FRAME was NULL. The comment
959 that went with it made the claim ...
961 ``This screws value_of_variable, which just wants a nice
962 clean NULL return from block_innermost_frame if there are no
963 frames. I don't think I've ever seen this message happen
964 otherwise. And returning NULL here is a perfectly legitimate
967 Per the above, this code shouldn't even be called with a NULL
969 return current_frame
;
972 /* Only try to do the unwind once. */
973 if (next_frame
->prev_p
)
974 return next_frame
->prev
;
975 next_frame
->prev_p
= 1;
977 /* On some machines it is possible to call a function without
978 setting up a stack frame for it. On these machines, we
979 define this macro to take two args; a frameinfo pointer
980 identifying a frame and a variable to set or clear if it is
981 or isn't leafless. */
983 /* Still don't want to worry about this except on the innermost
984 frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
985 function invocation. */
986 if (next_frame
->next
== NULL
)
987 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
988 the frame chain, not just the inner most frame! The generic,
989 per-architecture, frame code should handle this and the below
990 should simply be removed. */
991 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
996 /* A frameless inner-most frame. The `FP' (which isn't an
997 architecture frame-pointer register!) of the caller is the same
999 /* FIXME: 2002-11-09: There isn't any reason to special case this
1000 edge condition. Instead the per-architecture code should hande
1002 address
= get_frame_base (next_frame
);
1005 /* Two macros defined in tm.h specify the machine-dependent
1006 actions to be performed here.
1008 First, get the frame's chain-pointer.
1010 If that is zero, the frame is the outermost frame or a leaf
1011 called by the outermost frame. This means that if start
1012 calls main without a frame, we'll return 0 (which is fine
1015 Nope; there's a problem. This also returns when the current
1016 routine is a leaf of main. This is unacceptable. We move
1017 this to after the ffi test; I'd rather have backtraces from
1018 start go curfluy than have an abort called from main not show
1020 address
= FRAME_CHAIN (next_frame
);
1022 /* FIXME: cagney/2002-06-08: There should be two tests here.
1023 The first would check for a valid frame chain based on a user
1024 selectable policy. The default being ``stop at main'' (as
1025 implemented by generic_func_frame_chain_valid()). Other
1026 policies would be available - stop at NULL, .... The second
1027 test, if provided by the target architecture, would check for
1028 more exotic cases - most target architectures wouldn't bother
1029 with this second case. */
1030 if (!FRAME_CHAIN_VALID (address
, next_frame
))
1036 /* Create an initially zero previous frame. */
1037 prev
= (struct frame_info
*)
1038 obstack_alloc (&frame_cache_obstack
,
1039 sizeof (struct frame_info
));
1040 memset (prev
, 0, sizeof (struct frame_info
));
1043 next_frame
->prev
= prev
;
1044 prev
->next
= next_frame
;
1045 prev
->frame
= address
;
1046 prev
->level
= next_frame
->level
+ 1;
1047 /* FIXME: cagney/2002-11-18: Should be setting the frame's type
1048 here, before anything else, and not last. Various INIT functions
1049 are full of work-arounds for the frames type not being set
1050 correctly from the word go. Ulgh! */
1051 prev
->type
= NORMAL_FRAME
;
1053 /* This change should not be needed, FIXME! We should determine
1054 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1055 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
1056 express what goes on here.
1058 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
1059 (where the PC is already set up) and here (where it isn't).
1060 DEPRECATED_INIT_FRAME_PC is only called from here, always after
1061 INIT_EXTRA_FRAME_INFO.
1063 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
1064 PC value (which hasn't been set yet). Some other machines appear
1065 to require INIT_EXTRA_FRAME_INFO before they can do
1066 DEPRECATED_INIT_FRAME_PC. Phoo.
1068 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1069 complication to an already overcomplicated part of GDB.
1070 gnu@cygnus.com, 15Sep92.
1072 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1073 INIT_EXTRA_FRAME_INFO, one possible scheme:
1075 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1076 (read_fp ()), read_pc ()). Machines with extra frame info would
1077 do that (or the local equivalent) and then set the extra fields.
1079 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1080 create_new_frame would no longer init extra frame info;
1081 SETUP_ARBITRARY_FRAME would have to do that.
1083 INIT_PREV_FRAME(fromleaf, prev) Replace INIT_EXTRA_FRAME_INFO and
1084 DEPRECATED_INIT_FRAME_PC. This should also return a flag saying
1085 whether to keep the new frame, or whether to discard it, because
1086 on some machines (e.g. mips) it is really awkward to have
1087 FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
1088 no good way to get information deduced in FRAME_CHAIN_VALID into
1089 the extra fields of the new frame). std_frame_pc(fromleaf, prev)
1091 This is the default setting for INIT_PREV_FRAME. It just does
1092 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1093 will call it from INIT_PREV_FRAME (either at the beginning, the
1094 end, or in the middle). Some machines won't use it.
1096 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1098 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1099 reason for things to be this complicated.
1101 The trick is to assume that there is always a frame. Instead of
1102 special casing the inner-most frame, create fake frame
1103 (containing the hardware registers) that is inner to the
1104 user-visible inner-most frame (...) and then unwind from that.
1105 That way architecture code can use use the standard
1106 frame_XX_unwind() functions and not differentiate between the
1107 inner most and any other case.
1109 Since there is always a frame to unwind from, there is always
1110 somewhere (NEXT_FRAME) to store all the info needed to construct
1111 a new (previous) frame without having to first create it. This
1112 means that the convolution below - needing to carefully order a
1113 frame's initialization - isn't needed.
1115 The irony here though, is that FRAME_CHAIN(), at least for a more
1116 up-to-date architecture, always calls FRAME_SAVED_PC(), and
1117 FRAME_SAVED_PC() computes the PC but without first needing the
1118 frame! Instead of the convolution below, we could have simply
1119 called FRAME_SAVED_PC() and been done with it! Note that
1120 FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
1121 function does have somewhere to cache that PC value. */
1123 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1124 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1126 if (INIT_EXTRA_FRAME_INFO_P ())
1127 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1129 /* This entry is in the frame queue now, which is good since
1130 FRAME_SAVED_PC may use that queue to figure out its value (see
1131 tm-sparc.h). We want the pc saved in the inferior frame. */
1132 if (DEPRECATED_INIT_FRAME_PC_P ())
1133 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1135 /* If ->frame and ->pc are unchanged, we are in the process of
1136 getting ourselves into an infinite backtrace. Some architectures
1137 check this in FRAME_CHAIN or thereabouts, but it seems like there
1138 is no reason this can't be an architecture-independent check. */
1139 if (prev
->frame
== next_frame
->frame
1140 && prev
->pc
== next_frame
->pc
)
1142 next_frame
->prev
= NULL
;
1143 obstack_free (&frame_cache_obstack
, prev
);
1147 /* Initialize the code used to unwind the frame PREV based on the PC
1148 (and probably other architectural information). The PC lets you
1149 check things like the debug info at that point (dwarf2cfi?) and
1150 use that to decide how the frame should be unwound. */
1151 set_unwind_by_pc (prev
->pc
, prev
->frame
, &prev
->register_unwind
,
1152 &prev
->pc_unwind
, &prev
->id_unwind
);
1154 /* NOTE: cagney/2002-11-18: The code segments, found in
1155 create_new_frame and get_prev_frame(), that initializes the
1156 frames type is subtly different. The latter only updates ->type
1157 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1158 get_prev_frame() overriding the frame's type when the INIT code
1159 has previously set it. This is really somewhat bogus. The
1160 initialization, as seen in create_new_frame(), should occur
1161 before the INIT function has been called. */
1162 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1163 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1164 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1165 : pc_in_dummy_frame (prev
->pc
)))
1166 prev
->type
= DUMMY_FRAME
;
1169 /* FIXME: cagney/2002-11-10: This should be moved to before the
1170 INIT code above so that the INIT code knows what the frame's
1171 type is (in fact, for a [generic] dummy-frame, the type can
1172 be set and then the entire initialization can be skipped.
1173 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1176 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1177 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1178 prev
->type
= SIGTRAMP_FRAME
;
1179 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1180 architectures are forcing the frame's type in INIT so we
1181 don't want to override it here. Remember, NORMAL_FRAME == 0,
1182 so it all works (just :-/). Once this initialization is
1183 moved to the start of this function, all this nastness will
1191 get_frame_pc (struct frame_info
*frame
)
1197 pc_notcurrent (struct frame_info
*frame
)
1199 /* If FRAME is not the innermost frame, that normally means that
1200 FRAME->pc points at the return instruction (which is *after* the
1201 call instruction), and we want to get the line containing the
1202 call (because the call is where the user thinks the program is).
1203 However, if the next frame is either a SIGTRAMP_FRAME or a
1204 DUMMY_FRAME, then the next frame will contain a saved interrupt
1205 PC and such a PC indicates the current (rather than next)
1206 instruction/line, consequently, for such cases, want to get the
1207 line containing fi->pc. */
1208 struct frame_info
*next
= get_next_frame (frame
);
1209 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1214 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1216 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1219 /* Per "frame.h", return the ``address'' of the frame. Code should
1220 really be using get_frame_id(). */
1222 get_frame_base (struct frame_info
*fi
)
1227 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1228 or -1 for a NULL frame. */
1231 frame_relative_level (struct frame_info
*fi
)
1240 get_frame_type (struct frame_info
*frame
)
1242 /* Some targets still don't use [generic] dummy frames. Catch them
1244 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1245 && deprecated_frame_in_dummy (frame
))
1251 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1253 /* Arrrg! See comment in "frame.h". */
1257 #ifdef FRAME_FIND_SAVED_REGS
1258 /* XXX - deprecated. This is a compatibility function for targets
1259 that do not yet implement FRAME_INIT_SAVED_REGS. */
1260 /* Find the addresses in which registers are saved in FRAME. */
1263 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1264 struct frame_saved_regs
*saved_regs_addr
)
1266 if (frame
->saved_regs
== NULL
)
1268 frame
->saved_regs
= (CORE_ADDR
*)
1269 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
1271 if (saved_regs_addr
== NULL
)
1273 struct frame_saved_regs saved_regs
;
1274 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1275 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1279 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1280 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1285 struct frame_extra_info
*
1286 get_frame_extra_info (struct frame_info
*fi
)
1288 return fi
->extra_info
;
1291 struct frame_extra_info
*
1292 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1294 fi
->extra_info
= frame_obstack_alloc (size
);
1295 memset (fi
->extra_info
, 0, size
);
1296 return fi
->extra_info
;
1300 deprecated_update_current_frame_pc_hack (CORE_ADDR pc
)
1302 /* FIXME: cagney/2002-12-06: Has the PC in the current frame
1303 changed? "infrun.c", Thanks to DECR_PC_AFTER_BREAK, can change
1304 the PC after the initial frame create. This puts things back in
1306 if (current_frame
!= NULL
)
1307 current_frame
->pc
= pc
;
1311 _initialize_frame (void)
1313 obstack_init (&frame_cache_obstack
);