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
);
473 /* Return the innermost (currently executing) stack frame. */
476 get_current_frame (void)
478 if (current_frame
== NULL
)
480 if (target_has_stack
)
481 current_frame
= create_new_frame (read_fp (), read_pc ());
485 return current_frame
;
488 /* The "selected" stack frame is used by default for local and arg
489 access. May be zero, for no selected frame. */
491 struct frame_info
*deprecated_selected_frame
;
493 /* Return the selected frame. Always non-null (unless there isn't an
494 inferior sufficient for creating a frame) in which case an error is
498 get_selected_frame (void)
500 if (deprecated_selected_frame
== NULL
)
501 /* Hey! Don't trust this. It should really be re-finding the
502 last selected frame of the currently selected thread. This,
503 though, is better than nothing. */
504 select_frame (get_current_frame ());
505 /* There is always a frame. */
506 gdb_assert (deprecated_selected_frame
!= NULL
);
507 return deprecated_selected_frame
;
510 /* Select frame FI (or NULL - to invalidate the current frame). */
513 select_frame (struct frame_info
*fi
)
515 register struct symtab
*s
;
517 deprecated_selected_frame
= fi
;
518 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
519 frame is being invalidated. */
520 if (selected_frame_level_changed_hook
)
521 selected_frame_level_changed_hook (frame_relative_level (fi
));
523 /* FIXME: kseitz/2002-08-28: It would be nice to call
524 selected_frame_level_changed_event right here, but due to limitations
525 in the current interfaces, we would end up flooding UIs with events
526 because select_frame is used extensively internally.
528 Once we have frame-parameterized frame (and frame-related) commands,
529 the event notification can be moved here, since this function will only
530 be called when the users selected frame is being changed. */
532 /* Ensure that symbols for this frame are read in. Also, determine the
533 source language of this frame, and switch to it if desired. */
536 s
= find_pc_symtab (fi
->pc
);
538 && s
->language
!= current_language
->la_language
539 && s
->language
!= language_unknown
540 && language_mode
== language_mode_auto
)
542 set_language (s
->language
);
547 /* Return the register saved in the simplistic ``saved_regs'' cache.
548 If the value isn't here AND a value is needed, try the next inner
552 frame_saved_regs_register_unwind (struct frame_info
*frame
, void **cache
,
553 int regnum
, int *optimizedp
,
554 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
555 int *realnump
, void *bufferp
)
557 /* There is always a frame at this point. And THIS is the frame
558 we're interested in. */
559 gdb_assert (frame
!= NULL
);
560 /* If we're using generic dummy frames, we'd better not be in a call
561 dummy. (generic_call_dummy_register_unwind ought to have been called
563 gdb_assert (!(DEPRECATED_USE_GENERIC_DUMMY_FRAMES
564 && (get_frame_type (frame
) == DUMMY_FRAME
)));
566 /* Load the saved_regs register cache. */
567 if (frame
->saved_regs
== NULL
)
568 FRAME_INIT_SAVED_REGS (frame
);
570 if (frame
->saved_regs
!= NULL
571 && frame
->saved_regs
[regnum
] != 0)
573 if (regnum
== SP_REGNUM
)
575 /* SP register treated specially. */
581 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
582 frame
->saved_regs
[regnum
]);
586 /* Any other register is saved in memory, fetch it but cache
587 a local copy of its value. */
589 *lvalp
= lval_memory
;
590 *addrp
= frame
->saved_regs
[regnum
];
595 /* Save each register value, as it is read in, in a
596 frame based cache. */
597 void **regs
= (*cache
);
600 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
602 regs
= frame_obstack_alloc (sizeof_cache
);
603 memset (regs
, 0, sizeof_cache
);
606 if (regs
[regnum
] == NULL
)
609 = frame_obstack_alloc (REGISTER_RAW_SIZE (regnum
));
610 read_memory (frame
->saved_regs
[regnum
], regs
[regnum
],
611 REGISTER_RAW_SIZE (regnum
));
613 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
615 /* Read the value in from memory. */
616 read_memory (frame
->saved_regs
[regnum
], bufferp
,
617 REGISTER_RAW_SIZE (regnum
));
624 /* No luck, assume this and the next frame have the same register
625 value. If a value is needed, pass the request on down the chain;
626 otherwise just return an indication that the value is in the same
627 register as the next frame. */
631 *lvalp
= lval_register
;
637 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
643 frame_saved_regs_pc_unwind (struct frame_info
*frame
, void **cache
)
645 return FRAME_SAVED_PC (frame
);
648 static struct frame_id
649 frame_saved_regs_id_unwind (struct frame_info
*next_frame
, void **cache
)
654 if (next_frame
->next
== NULL
)
655 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
656 the frame chain, not just the inner most frame! The generic,
657 per-architecture, frame code should handle this and the below
658 should simply be removed. */
659 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
664 /* A frameless inner-most frame. The `FP' (which isn't an
665 architecture frame-pointer register!) of the caller is the same
667 /* FIXME: 2002-11-09: There isn't any reason to special case this
668 edge condition. Instead the per-architecture code should hande
670 id
.base
= get_frame_base (next_frame
);
673 /* Two macros defined in tm.h specify the machine-dependent
674 actions to be performed here.
676 First, get the frame's chain-pointer.
678 If that is zero, the frame is the outermost frame or a leaf
679 called by the outermost frame. This means that if start
680 calls main without a frame, we'll return 0 (which is fine
683 Nope; there's a problem. This also returns when the current
684 routine is a leaf of main. This is unacceptable. We move
685 this to after the ffi test; I'd rather have backtraces from
686 start go curfluy than have an abort called from main not show
688 id
.base
= FRAME_CHAIN (next_frame
);
690 /* FIXME: cagney/2002-06-08: There should be two tests here.
691 The first would check for a valid frame chain based on a user
692 selectable policy. The default being ``stop at main'' (as
693 implemented by generic_func_frame_chain_valid()). Other
694 policies would be available - stop at NULL, .... The second
695 test, if provided by the target architecture, would check for
696 more exotic cases - most target architectures wouldn't bother
697 with this second case. */
698 if (!FRAME_CHAIN_VALID (id
.base
, next_frame
))
699 return null_frame_id
;
702 return null_frame_id
;
704 /* FIXME: cagney/2002-06-08: This should probably return the frame's
705 function and not the PC (a.k.a. resume address). */
706 id
.pc
= frame_pc_unwind (next_frame
);
710 /* Function: get_saved_register
711 Find register number REGNUM relative to FRAME and put its (raw,
712 target format) contents in *RAW_BUFFER.
714 Set *OPTIMIZED if the variable was optimized out (and thus can't be
715 fetched). Note that this is never set to anything other than zero
716 in this implementation.
718 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
719 whether the value was fetched from memory, from a register, or in a
720 strange and non-modifiable way (e.g. a frame pointer which was
721 calculated rather than fetched). We will use not_lval for values
722 fetched from generic dummy frames.
724 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
725 offset into the registers array. If the value is stored in a dummy
726 frame, set *ADDRP to zero.
728 To use this implementation, define a function called
729 "get_saved_register" in your target code, which simply passes all
730 of its arguments to this function.
732 The argument RAW_BUFFER must point to aligned memory. */
735 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
737 struct frame_info
*frame
, int regnum
,
738 enum lval_type
*lval
)
740 if (!target_has_registers
)
741 error ("No registers.");
743 /* Normal systems don't optimize out things with register numbers. */
744 if (optimized
!= NULL
)
747 if (addrp
) /* default assumption: not found in memory */
750 /* Note: since the current frame's registers could only have been
751 saved by frames INTERIOR TO the current frame, we skip examining
752 the current frame itself: otherwise, we would be getting the
753 previous frame's registers which were saved by the current frame. */
755 while (frame
&& ((frame
= frame
->next
) != NULL
))
757 if (get_frame_type (frame
) == DUMMY_FRAME
)
759 if (lval
) /* found it in a CALL_DUMMY frame */
762 /* FIXME: cagney/2002-06-26: This should be via the
763 gdbarch_register_read() method so that it, on the fly,
764 constructs either a raw or pseudo register from the raw
766 regcache_raw_read (generic_find_dummy_frame (frame
->pc
,
772 FRAME_INIT_SAVED_REGS (frame
);
773 if (frame
->saved_regs
!= NULL
774 && frame
->saved_regs
[regnum
] != 0)
776 if (lval
) /* found it saved on the stack */
778 if (regnum
== SP_REGNUM
)
780 if (raw_buffer
) /* SP register treated specially */
781 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
782 frame
->saved_regs
[regnum
]);
786 if (addrp
) /* any other register */
787 *addrp
= frame
->saved_regs
[regnum
];
789 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
790 REGISTER_RAW_SIZE (regnum
));
796 /* If we get thru the loop to this point, it means the register was
797 not saved in any frame. Return the actual live-register value. */
799 if (lval
) /* found it in a live register */
800 *lval
= lval_register
;
802 *addrp
= REGISTER_BYTE (regnum
);
804 deprecated_read_register_gen (regnum
, raw_buffer
);
807 /* Using the PC, select a mechanism for unwinding a frame returning
808 the previous frame. The register unwind function should, on
809 demand, initialize the ->context object. */
812 set_unwind_by_pc (CORE_ADDR pc
, CORE_ADDR fp
,
813 frame_register_unwind_ftype
**unwind_register
,
814 frame_pc_unwind_ftype
**unwind_pc
,
815 frame_id_unwind_ftype
**unwind_id
)
817 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
)
819 /* Still need to set this to something. The ``info frame'' code
820 calls this function to find out where the saved registers are.
821 Hopefully this is robust enough to stop any core dumps and
822 return vaguely correct values.. */
823 *unwind_register
= frame_saved_regs_register_unwind
;
824 *unwind_pc
= frame_saved_regs_pc_unwind
;
825 *unwind_id
= frame_saved_regs_id_unwind
;
827 else if (DEPRECATED_PC_IN_CALL_DUMMY_P ()
828 ? DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0)
829 : pc_in_dummy_frame (pc
))
831 *unwind_register
= dummy_frame_register_unwind
;
832 *unwind_pc
= dummy_frame_pc_unwind
;
833 *unwind_id
= dummy_frame_id_unwind
;
837 *unwind_register
= frame_saved_regs_register_unwind
;
838 *unwind_pc
= frame_saved_regs_pc_unwind
;
839 *unwind_id
= frame_saved_regs_id_unwind
;
843 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
844 Always returns a non-NULL value. */
847 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
849 struct frame_info
*fi
;
850 enum frame_type type
;
852 fi
= (struct frame_info
*)
853 obstack_alloc (&frame_cache_obstack
,
854 sizeof (struct frame_info
));
856 /* Zero all fields by default. */
857 memset (fi
, 0, sizeof (struct frame_info
));
861 /* NOTE: cagney/2002-11-18: The code segments, found in
862 create_new_frame and get_prev_frame(), that initializes the
863 frames type is subtly different. The latter only updates ->type
864 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
865 get_prev_frame() overriding the frame's type when the INIT code
866 has previously set it. This is really somewhat bogus. The
867 initialization, as seen in create_new_frame(), should occur
868 before the INIT function has been called. */
869 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
870 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
871 ? DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0)
872 : pc_in_dummy_frame (pc
)))
873 /* NOTE: cagney/2002-11-11: Does this even occure? */
878 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
879 if (PC_IN_SIGTRAMP (fi
->pc
, name
))
880 type
= SIGTRAMP_FRAME
;
886 if (INIT_EXTRA_FRAME_INFO_P ())
887 INIT_EXTRA_FRAME_INFO (0, fi
);
889 /* Select/initialize an unwind function. */
890 set_unwind_by_pc (fi
->pc
, fi
->frame
, &fi
->register_unwind
,
891 &fi
->pc_unwind
, &fi
->id_unwind
);
896 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
900 get_next_frame (struct frame_info
*frame
)
905 /* Flush the entire frame cache. */
908 flush_cached_frames (void)
910 /* Since we can't really be sure what the first object allocated was */
911 obstack_free (&frame_cache_obstack
, 0);
912 obstack_init (&frame_cache_obstack
);
914 current_frame
= NULL
; /* Invalidate cache */
916 annotate_frames_invalid ();
919 /* Flush the frame cache, and start a new one if necessary. */
922 reinit_frame_cache (void)
924 flush_cached_frames ();
926 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
927 if (PIDGET (inferior_ptid
) != 0)
929 select_frame (get_current_frame ());
933 /* Return a structure containing various interesting information
934 about the frame that called NEXT_FRAME. Returns NULL
935 if there is no such frame. */
938 get_prev_frame (struct frame_info
*next_frame
)
940 CORE_ADDR address
= 0;
941 struct frame_info
*prev
;
944 /* Return the inner-most frame, when the caller passes in NULL. */
945 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
946 caller should have previously obtained a valid frame using
947 get_selected_frame() and then called this code - only possibility
948 I can think of is code behaving badly. */
949 if (next_frame
== NULL
)
951 /* NOTE: cagney/2002-11-09: There was a code segment here that
952 would error out when CURRENT_FRAME was NULL. The comment
953 that went with it made the claim ...
955 ``This screws value_of_variable, which just wants a nice
956 clean NULL return from block_innermost_frame if there are no
957 frames. I don't think I've ever seen this message happen
958 otherwise. And returning NULL here is a perfectly legitimate
961 Per the above, this code shouldn't even be called with a NULL
963 return current_frame
;
966 /* Only try to do the unwind once. */
967 if (next_frame
->prev_p
)
968 return next_frame
->prev
;
969 next_frame
->prev_p
= 1;
971 /* On some machines it is possible to call a function without
972 setting up a stack frame for it. On these machines, we
973 define this macro to take two args; a frameinfo pointer
974 identifying a frame and a variable to set or clear if it is
975 or isn't leafless. */
977 /* Still don't want to worry about this except on the innermost
978 frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
979 function invocation. */
980 if (next_frame
->next
== NULL
)
981 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
982 the frame chain, not just the inner most frame! The generic,
983 per-architecture, frame code should handle this and the below
984 should simply be removed. */
985 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
990 /* A frameless inner-most frame. The `FP' (which isn't an
991 architecture frame-pointer register!) of the caller is the same
993 /* FIXME: 2002-11-09: There isn't any reason to special case this
994 edge condition. Instead the per-architecture code should hande
996 address
= get_frame_base (next_frame
);
999 /* Two macros defined in tm.h specify the machine-dependent
1000 actions to be performed here.
1002 First, get the frame's chain-pointer.
1004 If that is zero, the frame is the outermost frame or a leaf
1005 called by the outermost frame. This means that if start
1006 calls main without a frame, we'll return 0 (which is fine
1009 Nope; there's a problem. This also returns when the current
1010 routine is a leaf of main. This is unacceptable. We move
1011 this to after the ffi test; I'd rather have backtraces from
1012 start go curfluy than have an abort called from main not show
1014 address
= FRAME_CHAIN (next_frame
);
1016 /* FIXME: cagney/2002-06-08: There should be two tests here.
1017 The first would check for a valid frame chain based on a user
1018 selectable policy. The default being ``stop at main'' (as
1019 implemented by generic_func_frame_chain_valid()). Other
1020 policies would be available - stop at NULL, .... The second
1021 test, if provided by the target architecture, would check for
1022 more exotic cases - most target architectures wouldn't bother
1023 with this second case. */
1024 if (!FRAME_CHAIN_VALID (address
, next_frame
))
1030 /* Create an initially zero previous frame. */
1031 prev
= (struct frame_info
*)
1032 obstack_alloc (&frame_cache_obstack
,
1033 sizeof (struct frame_info
));
1034 memset (prev
, 0, sizeof (struct frame_info
));
1037 next_frame
->prev
= prev
;
1038 prev
->next
= next_frame
;
1039 prev
->frame
= address
;
1040 prev
->level
= next_frame
->level
+ 1;
1041 /* FIXME: cagney/2002-11-18: Should be setting the frame's type
1042 here, before anything else, and not last. Various INIT functions
1043 are full of work-arounds for the frames type not being set
1044 correctly from the word go. Ulgh! */
1045 prev
->type
= NORMAL_FRAME
;
1047 /* This change should not be needed, FIXME! We should determine
1048 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1049 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
1050 express what goes on here.
1052 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
1053 (where the PC is already set up) and here (where it isn't).
1054 DEPRECATED_INIT_FRAME_PC is only called from here, always after
1055 INIT_EXTRA_FRAME_INFO.
1057 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
1058 PC value (which hasn't been set yet). Some other machines appear
1059 to require INIT_EXTRA_FRAME_INFO before they can do
1060 DEPRECATED_INIT_FRAME_PC. Phoo.
1062 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1063 complication to an already overcomplicated part of GDB.
1064 gnu@cygnus.com, 15Sep92.
1066 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1067 INIT_EXTRA_FRAME_INFO, one possible scheme:
1069 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1070 (read_fp ()), read_pc ()). Machines with extra frame info would
1071 do that (or the local equivalent) and then set the extra fields.
1073 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1074 create_new_frame would no longer init extra frame info;
1075 SETUP_ARBITRARY_FRAME would have to do that.
1077 INIT_PREV_FRAME(fromleaf, prev) Replace INIT_EXTRA_FRAME_INFO and
1078 DEPRECATED_INIT_FRAME_PC. This should also return a flag saying
1079 whether to keep the new frame, or whether to discard it, because
1080 on some machines (e.g. mips) it is really awkward to have
1081 FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
1082 no good way to get information deduced in FRAME_CHAIN_VALID into
1083 the extra fields of the new frame). std_frame_pc(fromleaf, prev)
1085 This is the default setting for INIT_PREV_FRAME. It just does
1086 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1087 will call it from INIT_PREV_FRAME (either at the beginning, the
1088 end, or in the middle). Some machines won't use it.
1090 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1092 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1093 reason for things to be this complicated.
1095 The trick is to assume that there is always a frame. Instead of
1096 special casing the inner-most frame, create fake frame
1097 (containing the hardware registers) that is inner to the
1098 user-visible inner-most frame (...) and then unwind from that.
1099 That way architecture code can use use the standard
1100 frame_XX_unwind() functions and not differentiate between the
1101 inner most and any other case.
1103 Since there is always a frame to unwind from, there is always
1104 somewhere (NEXT_FRAME) to store all the info needed to construct
1105 a new (previous) frame without having to first create it. This
1106 means that the convolution below - needing to carefully order a
1107 frame's initialization - isn't needed.
1109 The irony here though, is that FRAME_CHAIN(), at least for a more
1110 up-to-date architecture, always calls FRAME_SAVED_PC(), and
1111 FRAME_SAVED_PC() computes the PC but without first needing the
1112 frame! Instead of the convolution below, we could have simply
1113 called FRAME_SAVED_PC() and been done with it! Note that
1114 FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
1115 function does have somewhere to cache that PC value. */
1117 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1118 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1120 if (INIT_EXTRA_FRAME_INFO_P ())
1121 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1123 /* This entry is in the frame queue now, which is good since
1124 FRAME_SAVED_PC may use that queue to figure out its value (see
1125 tm-sparc.h). We want the pc saved in the inferior frame. */
1126 if (DEPRECATED_INIT_FRAME_PC_P ())
1127 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1129 /* If ->frame and ->pc are unchanged, we are in the process of
1130 getting ourselves into an infinite backtrace. Some architectures
1131 check this in FRAME_CHAIN or thereabouts, but it seems like there
1132 is no reason this can't be an architecture-independent check. */
1133 if (prev
->frame
== next_frame
->frame
1134 && prev
->pc
== next_frame
->pc
)
1136 next_frame
->prev
= NULL
;
1137 obstack_free (&frame_cache_obstack
, prev
);
1141 /* Initialize the code used to unwind the frame PREV based on the PC
1142 (and probably other architectural information). The PC lets you
1143 check things like the debug info at that point (dwarf2cfi?) and
1144 use that to decide how the frame should be unwound. */
1145 set_unwind_by_pc (prev
->pc
, prev
->frame
, &prev
->register_unwind
,
1146 &prev
->pc_unwind
, &prev
->id_unwind
);
1148 /* NOTE: cagney/2002-11-18: The code segments, found in
1149 create_new_frame and get_prev_frame(), that initializes the
1150 frames type is subtly different. The latter only updates ->type
1151 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1152 get_prev_frame() overriding the frame's type when the INIT code
1153 has previously set it. This is really somewhat bogus. The
1154 initialization, as seen in create_new_frame(), should occur
1155 before the INIT function has been called. */
1156 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1157 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1158 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1159 : pc_in_dummy_frame (prev
->pc
)))
1160 prev
->type
= DUMMY_FRAME
;
1163 /* FIXME: cagney/2002-11-10: This should be moved to before the
1164 INIT code above so that the INIT code knows what the frame's
1165 type is (in fact, for a [generic] dummy-frame, the type can
1166 be set and then the entire initialization can be skipped.
1167 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1170 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1171 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1172 prev
->type
= SIGTRAMP_FRAME
;
1173 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1174 architectures are forcing the frame's type in INIT so we
1175 don't want to override it here. Remember, NORMAL_FRAME == 0,
1176 so it all works (just :-/). Once this initialization is
1177 moved to the start of this function, all this nastness will
1185 get_frame_pc (struct frame_info
*frame
)
1191 pc_notcurrent (struct frame_info
*frame
)
1193 /* If FRAME is not the innermost frame, that normally means that
1194 FRAME->pc points at the return instruction (which is *after* the
1195 call instruction), and we want to get the line containing the
1196 call (because the call is where the user thinks the program is).
1197 However, if the next frame is either a SIGTRAMP_FRAME or a
1198 DUMMY_FRAME, then the next frame will contain a saved interrupt
1199 PC and such a PC indicates the current (rather than next)
1200 instruction/line, consequently, for such cases, want to get the
1201 line containing fi->pc. */
1202 struct frame_info
*next
= get_next_frame (frame
);
1203 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1208 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1210 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1213 /* Per "frame.h", return the ``address'' of the frame. Code should
1214 really be using get_frame_id(). */
1216 get_frame_base (struct frame_info
*fi
)
1221 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1222 or -1 for a NULL frame. */
1225 frame_relative_level (struct frame_info
*fi
)
1234 get_frame_type (struct frame_info
*frame
)
1236 /* Some targets still don't use [generic] dummy frames. Catch them
1238 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1239 && deprecated_frame_in_dummy (frame
))
1245 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1247 /* Arrrg! See comment in "frame.h". */
1251 #ifdef FRAME_FIND_SAVED_REGS
1252 /* XXX - deprecated. This is a compatibility function for targets
1253 that do not yet implement FRAME_INIT_SAVED_REGS. */
1254 /* Find the addresses in which registers are saved in FRAME. */
1257 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1258 struct frame_saved_regs
*saved_regs_addr
)
1260 if (frame
->saved_regs
== NULL
)
1262 frame
->saved_regs
= (CORE_ADDR
*)
1263 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
1265 if (saved_regs_addr
== NULL
)
1267 struct frame_saved_regs saved_regs
;
1268 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1269 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1273 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1274 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1279 struct frame_extra_info
*
1280 get_frame_extra_info (struct frame_info
*fi
)
1282 return fi
->extra_info
;
1285 struct frame_extra_info
*
1286 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1288 fi
->extra_info
= frame_obstack_alloc (size
);
1289 memset (fi
->extra_info
, 0, size
);
1290 return fi
->extra_info
;
1294 deprecated_update_current_frame_pc_hack (CORE_ADDR pc
)
1296 /* FIXME: cagney/2002-12-06: Has the PC in the current frame
1297 changed? "infrun.c", Thanks to DECR_PC_AFTER_BREAK, can change
1298 the PC after the initial frame create. This puts things back in
1300 if (current_frame
!= NULL
)
1301 current_frame
->pc
= pc
;
1305 _initialize_frame (void)
1307 obstack_init (&frame_cache_obstack
);