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"
37 #include "frame-unwind.h"
41 /* Flag to indicate whether backtraces should stop at main. */
43 static int backtrace_below_main
;
45 /* Return a frame uniq ID that can be used to, later, re-find the
49 get_frame_id (struct frame_info
*fi
)
64 const struct frame_id null_frame_id
; /* All zeros. */
67 frame_id_build (CORE_ADDR base
, CORE_ADDR func_or_pc
)
76 frame_id_p (struct frame_id l
)
78 /* The .func can be NULL but the .base cannot. */
83 frame_id_eq (struct frame_id l
, struct frame_id r
)
85 /* If .base is different, the frames are different. */
88 /* Add a test to check that the frame ID's are for the same function
94 frame_id_inner (struct frame_id l
, struct frame_id r
)
96 /* Only return non-zero when strictly inner than. Note that, per
97 comment in "frame.h", there is some fuzz here. Frameless
98 functions are not strictly inner than (same .base but different
100 return INNER_THAN (l
.base
, r
.base
);
104 frame_find_by_id (struct frame_id id
)
106 struct frame_info
*frame
;
108 /* ZERO denotes the null frame, let the caller decide what to do
109 about it. Should it instead return get_current_frame()? */
110 if (!frame_id_p (id
))
113 for (frame
= get_current_frame ();
115 frame
= get_prev_frame (frame
))
117 struct frame_id
this = get_frame_id (frame
);
118 if (frame_id_eq (id
, this))
119 /* An exact match. */
121 if (frame_id_inner (id
, this))
124 /* Either, we're not yet gone far enough out along the frame
125 chain (inner(this,id), or we're comparing frameless functions
126 (same .base, different .func, no test available). Struggle
127 on until we've definitly gone to far. */
133 frame_pc_unwind (struct frame_info
*frame
)
135 if (!frame
->pc_unwind_cache_p
)
137 frame
->pc_unwind_cache
= frame
->unwind
->pc (frame
, &frame
->unwind_cache
);
138 frame
->pc_unwind_cache_p
= 1;
140 return frame
->pc_unwind_cache
;
144 frame_id_unwind (struct frame_info
*frame
)
146 if (!frame
->id_unwind_cache_p
)
148 frame
->unwind
->id (frame
, &frame
->unwind_cache
, &frame
->id_unwind_cache
);
149 frame
->id_unwind_cache_p
= 1;
151 return frame
->id_unwind_cache
;
155 frame_pop (struct frame_info
*frame
)
157 /* FIXME: cagney/2003-01-18: There is probably a chicken-egg problem
158 with passing in current_regcache. The pop function needs to be
159 written carefully so as to not overwrite registers whose [old]
160 values are needed to restore other registers. Instead, this code
161 should pass in a scratch cache and, as a second step, restore the
162 registers using that. */
163 frame
->unwind
->pop (frame
, &frame
->unwind_cache
, current_regcache
);
164 flush_cached_frames ();
168 frame_register_unwind (struct frame_info
*frame
, int regnum
,
169 int *optimizedp
, enum lval_type
*lvalp
,
170 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
172 struct frame_unwind_cache
*cache
;
174 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
175 that the value proper does not need to be fetched. */
176 gdb_assert (optimizedp
!= NULL
);
177 gdb_assert (lvalp
!= NULL
);
178 gdb_assert (addrp
!= NULL
);
179 gdb_assert (realnump
!= NULL
);
180 /* gdb_assert (bufferp != NULL); */
182 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
183 special case, there was always an inner frame dedicated to the
184 hardware registers. Unfortunatly, there is too much unwind code
185 around that looks up/down the frame chain while making the
186 assumption that each frame level is using the same unwind code. */
190 /* We're in the inner-most frame, get the value direct from the
193 *lvalp
= lval_register
;
194 /* ULGH! Code uses the offset into the raw register byte array
195 as a way of identifying a register. */
196 *addrp
= REGISTER_BYTE (regnum
);
197 /* Should this code test ``register_cached (regnum) < 0'' and do
198 something like set realnum to -1 when the register isn't
202 deprecated_read_register_gen (regnum
, bufferp
);
206 /* Ask this frame to unwind its register. */
207 frame
->unwind
->reg (frame
, &frame
->unwind_cache
, regnum
,
208 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
212 frame_register (struct frame_info
*frame
, int regnum
,
213 int *optimizedp
, enum lval_type
*lvalp
,
214 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
216 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
217 that the value proper does not need to be fetched. */
218 gdb_assert (optimizedp
!= NULL
);
219 gdb_assert (lvalp
!= NULL
);
220 gdb_assert (addrp
!= NULL
);
221 gdb_assert (realnump
!= NULL
);
222 /* gdb_assert (bufferp != NULL); */
224 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
225 of the register in the register cache. It should instead return
226 the REGNUM corresponding to that register. Translate the . */
227 if (GET_SAVED_REGISTER_P ())
229 GET_SAVED_REGISTER (bufferp
, optimizedp
, addrp
, frame
, regnum
, lvalp
);
230 /* Compute the REALNUM if the caller wants it. */
231 if (*lvalp
== lval_register
)
234 for (regnum
= 0; regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
; regnum
++)
236 if (*addrp
== register_offset_hack (current_gdbarch
, regnum
))
242 internal_error (__FILE__
, __LINE__
,
243 "Failed to compute the register number corresponding"
244 " to 0x%s", paddr_d (*addrp
));
250 /* Reached the the bottom (youngest, inner most) of the frame chain
251 (youngest, inner most) frame, go direct to the hardware register
252 cache (do not pass go, do not try to cache the value, ...). The
253 unwound value would have been cached in frame->next but that
254 doesn't exist. This doesn't matter as the hardware register
255 cache is stopping any unnecessary accesses to the target. */
257 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
258 special case, there was always an inner frame dedicated to the
259 hardware registers. Unfortunatly, there is too much unwind code
260 around that looks up/down the frame chain while making the
261 assumption that each frame level is using the same unwind code. */
264 frame_register_unwind (NULL
, regnum
, optimizedp
, lvalp
, addrp
, realnump
,
267 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
272 frame_unwind_signed_register (struct frame_info
*frame
, int regnum
,
279 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
280 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
282 (*val
) = extract_signed_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
286 frame_unwind_unsigned_register (struct frame_info
*frame
, int regnum
,
293 void *buf
= alloca (MAX_REGISTER_RAW_SIZE
);
294 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
296 (*val
) = extract_unsigned_integer (buf
, REGISTER_VIRTUAL_SIZE (regnum
));
300 frame_read_unsigned_register (struct frame_info
*frame
, int regnum
,
303 /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is
304 always a frame. Both this, and the equivalent
305 frame_read_signed_register() function, can only be called with a
306 valid frame. If, for some reason, this function is called
307 without a frame then the problem isn't here, but rather in the
308 caller. It should of first created a frame and then passed that
310 /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the
311 ``current_frame'' should not be treated as a special case. While
312 ``get_next_frame (current_frame) == NULL'' currently holds, it
313 should, as far as possible, not be relied upon. In the future,
314 ``get_next_frame (current_frame)'' may instead simply return a
315 normal frame object that simply always gets register values from
316 the register cache. Consequently, frame code should try to avoid
317 tests like ``if get_next_frame() == NULL'' and instead just rely
318 on recursive frame calls (like the below code) when manipulating
320 gdb_assert (frame
!= NULL
);
321 frame_unwind_unsigned_register (get_next_frame (frame
), regnum
, val
);
325 frame_read_signed_register (struct frame_info
*frame
, int regnum
,
328 /* See note in frame_read_unsigned_register(). */
329 gdb_assert (frame
!= NULL
);
330 frame_unwind_signed_register (get_next_frame (frame
), regnum
, val
);
334 generic_unwind_get_saved_register (char *raw_buffer
,
337 struct frame_info
*frame
,
339 enum lval_type
*lvalp
)
344 enum lval_type lvalx
;
346 if (!target_has_registers
)
347 error ("No registers.");
349 /* Keep things simple, ensure that all the pointers (except valuep)
351 if (optimizedp
== NULL
)
352 optimizedp
= &optimizedx
;
358 /* Reached the the bottom (youngest, inner most) of the frame chain
359 (youngest, inner most) frame, go direct to the hardware register
360 cache (do not pass go, do not try to cache the value, ...). The
361 unwound value would have been cached in frame->next but that
362 doesn't exist. This doesn't matter as the hardware register
363 cache is stopping any unnecessary accesses to the target. */
365 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
366 special case, there was always an inner frame dedicated to the
367 hardware registers. Unfortunatly, there is too much unwind code
368 around that looks up/down the frame chain while making the
369 assumption that each frame level is using the same unwind code. */
372 frame_register_unwind (NULL
, regnum
, optimizedp
, lvalp
, addrp
, &realnumx
,
375 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
376 &realnumx
, raw_buffer
);
380 get_saved_register (char *raw_buffer
,
383 struct frame_info
*frame
,
385 enum lval_type
*lval
)
387 if (GET_SAVED_REGISTER_P ())
389 GET_SAVED_REGISTER (raw_buffer
, optimized
, addrp
, frame
, regnum
, lval
);
392 generic_unwind_get_saved_register (raw_buffer
, optimized
, addrp
, frame
,
396 /* frame_register_read ()
398 Find and return the value of REGNUM for the specified stack frame.
399 The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
401 Returns 0 if the register value could not be found. */
404 frame_register_read (struct frame_info
*frame
, int regnum
, void *myaddr
)
410 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
412 /* FIXME: cagney/2002-05-15: This test, is just bogus.
414 It indicates that the target failed to supply a value for a
415 register because it was "not available" at this time. Problem
416 is, the target still has the register and so get saved_register()
417 may be returning a value saved on the stack. */
419 if (register_cached (regnum
) < 0)
420 return 0; /* register value not available */
426 /* Map between a frame register number and its name. A frame register
427 space is a superset of the cooked register space --- it also
428 includes builtin registers. */
431 frame_map_name_to_regnum (const char *name
, int len
)
435 /* Search register name space. */
436 for (i
= 0; i
< NUM_REGS
+ NUM_PSEUDO_REGS
; i
++)
437 if (REGISTER_NAME (i
) && len
== strlen (REGISTER_NAME (i
))
438 && strncmp (name
, REGISTER_NAME (i
), len
) == 0)
443 /* Try builtin registers. */
444 i
= builtin_reg_map_name_to_regnum (name
, len
);
447 /* A builtin register doesn't fall into the architecture's
449 gdb_assert (i
>= NUM_REGS
+ NUM_PSEUDO_REGS
);
457 frame_map_regnum_to_name (int regnum
)
461 if (regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
)
462 return REGISTER_NAME (regnum
);
463 return builtin_reg_map_regnum_to_name (regnum
);
466 /* Info about the innermost stack frame (contents of FP register) */
468 static struct frame_info
*current_frame
;
470 /* Cache for frame addresses already read by gdb. Valid only while
471 inferior is stopped. Control variables for the frame cache should
472 be local to this module. */
474 static struct obstack frame_cache_obstack
;
477 frame_obstack_zalloc (unsigned long size
)
479 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
480 memset (data
, 0, size
);
485 frame_saved_regs_zalloc (struct frame_info
*fi
)
487 fi
->saved_regs
= (CORE_ADDR
*)
488 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
489 return fi
->saved_regs
;
493 get_frame_saved_regs (struct frame_info
*fi
)
495 return fi
->saved_regs
;
498 /* Return the innermost (currently executing) stack frame. */
501 get_current_frame (void)
503 if (current_frame
== NULL
)
505 if (target_has_stack
)
506 current_frame
= create_new_frame (read_fp (), read_pc ());
510 return current_frame
;
513 /* The "selected" stack frame is used by default for local and arg
514 access. May be zero, for no selected frame. */
516 struct frame_info
*deprecated_selected_frame
;
518 /* Return the selected frame. Always non-null (unless there isn't an
519 inferior sufficient for creating a frame) in which case an error is
523 get_selected_frame (void)
525 if (deprecated_selected_frame
== NULL
)
526 /* Hey! Don't trust this. It should really be re-finding the
527 last selected frame of the currently selected thread. This,
528 though, is better than nothing. */
529 select_frame (get_current_frame ());
530 /* There is always a frame. */
531 gdb_assert (deprecated_selected_frame
!= NULL
);
532 return deprecated_selected_frame
;
535 /* Select frame FI (or NULL - to invalidate the current frame). */
538 select_frame (struct frame_info
*fi
)
540 register struct symtab
*s
;
542 deprecated_selected_frame
= fi
;
543 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
544 frame is being invalidated. */
545 if (selected_frame_level_changed_hook
)
546 selected_frame_level_changed_hook (frame_relative_level (fi
));
548 /* FIXME: kseitz/2002-08-28: It would be nice to call
549 selected_frame_level_changed_event right here, but due to limitations
550 in the current interfaces, we would end up flooding UIs with events
551 because select_frame is used extensively internally.
553 Once we have frame-parameterized frame (and frame-related) commands,
554 the event notification can be moved here, since this function will only
555 be called when the users selected frame is being changed. */
557 /* Ensure that symbols for this frame are read in. Also, determine the
558 source language of this frame, and switch to it if desired. */
561 s
= find_pc_symtab (fi
->pc
);
563 && s
->language
!= current_language
->la_language
564 && s
->language
!= language_unknown
565 && language_mode
== language_mode_auto
)
567 set_language (s
->language
);
572 /* Return the register saved in the simplistic ``saved_regs'' cache.
573 If the value isn't here AND a value is needed, try the next inner
577 frame_saved_regs_register_unwind (struct frame_info
*frame
, void **cache
,
578 int regnum
, int *optimizedp
,
579 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
580 int *realnump
, void *bufferp
)
582 /* There is always a frame at this point. And THIS is the frame
583 we're interested in. */
584 gdb_assert (frame
!= NULL
);
585 /* If we're using generic dummy frames, we'd better not be in a call
586 dummy. (generic_call_dummy_register_unwind ought to have been called
588 gdb_assert (!(DEPRECATED_USE_GENERIC_DUMMY_FRAMES
589 && (get_frame_type (frame
) == DUMMY_FRAME
)));
591 /* Only (older) architectures that implement the
592 FRAME_INIT_SAVED_REGS method should be using this function. */
593 gdb_assert (FRAME_INIT_SAVED_REGS_P ());
595 /* Load the saved_regs register cache. */
596 if (frame
->saved_regs
== NULL
)
597 FRAME_INIT_SAVED_REGS (frame
);
599 if (frame
->saved_regs
!= NULL
600 && frame
->saved_regs
[regnum
] != 0)
602 if (regnum
== SP_REGNUM
)
604 /* SP register treated specially. */
610 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
611 frame
->saved_regs
[regnum
]);
615 /* Any other register is saved in memory, fetch it but cache
616 a local copy of its value. */
618 *lvalp
= lval_memory
;
619 *addrp
= frame
->saved_regs
[regnum
];
624 /* Save each register value, as it is read in, in a
625 frame based cache. */
626 void **regs
= (*cache
);
629 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
631 regs
= frame_obstack_zalloc (sizeof_cache
);
634 if (regs
[regnum
] == NULL
)
637 = frame_obstack_zalloc (REGISTER_RAW_SIZE (regnum
));
638 read_memory (frame
->saved_regs
[regnum
], regs
[regnum
],
639 REGISTER_RAW_SIZE (regnum
));
641 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
643 /* Read the value in from memory. */
644 read_memory (frame
->saved_regs
[regnum
], bufferp
,
645 REGISTER_RAW_SIZE (regnum
));
652 /* No luck, assume this and the next frame have the same register
653 value. If a value is needed, pass the request on down the chain;
654 otherwise just return an indication that the value is in the same
655 register as the next frame. */
659 *lvalp
= lval_register
;
665 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
671 frame_saved_regs_pc_unwind (struct frame_info
*frame
, void **cache
)
673 return FRAME_SAVED_PC (frame
);
677 frame_saved_regs_id_unwind (struct frame_info
*next_frame
, void **cache
,
684 /* Start out by assuming it's NULL. */
685 (*id
) = null_frame_id
;
687 if (next_frame
->next
== NULL
)
688 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
689 the frame chain, not just the inner most frame! The generic,
690 per-architecture, frame code should handle this and the below
691 should simply be removed. */
692 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
697 /* A frameless inner-most frame. The `FP' (which isn't an
698 architecture frame-pointer register!) of the caller is the same
700 /* FIXME: 2002-11-09: There isn't any reason to special case this
701 edge condition. Instead the per-architecture code should hande
703 base
= get_frame_base (next_frame
);
706 /* Two macros defined in tm.h specify the machine-dependent
707 actions to be performed here.
709 First, get the frame's chain-pointer.
711 If that is zero, the frame is the outermost frame or a leaf
712 called by the outermost frame. This means that if start
713 calls main without a frame, we'll return 0 (which is fine
716 Nope; there's a problem. This also returns when the current
717 routine is a leaf of main. This is unacceptable. We move
718 this to after the ffi test; I'd rather have backtraces from
719 start go curfluy than have an abort called from main not show
721 base
= FRAME_CHAIN (next_frame
);
723 if (!frame_chain_valid (base
, next_frame
))
729 /* FIXME: cagney/2002-06-08: This should probably return the frame's
730 function and not the PC (a.k.a. resume address). */
731 pc
= frame_pc_unwind (next_frame
);
737 frame_saved_regs_pop (struct frame_info
*fi
, void **cache
,
738 struct regcache
*regcache
)
740 gdb_assert (POP_FRAME_P ());
744 const struct frame_unwind trad_frame_unwinder
= {
745 frame_saved_regs_pop
,
746 frame_saved_regs_pc_unwind
,
747 frame_saved_regs_id_unwind
,
748 frame_saved_regs_register_unwind
750 const struct frame_unwind
*trad_frame_unwind
= &trad_frame_unwinder
;
753 /* Function: get_saved_register
754 Find register number REGNUM relative to FRAME and put its (raw,
755 target format) contents in *RAW_BUFFER.
757 Set *OPTIMIZED if the variable was optimized out (and thus can't be
758 fetched). Note that this is never set to anything other than zero
759 in this implementation.
761 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
762 whether the value was fetched from memory, from a register, or in a
763 strange and non-modifiable way (e.g. a frame pointer which was
764 calculated rather than fetched). We will use not_lval for values
765 fetched from generic dummy frames.
767 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
768 offset into the registers array. If the value is stored in a dummy
769 frame, set *ADDRP to zero.
771 To use this implementation, define a function called
772 "get_saved_register" in your target code, which simply passes all
773 of its arguments to this function.
775 The argument RAW_BUFFER must point to aligned memory. */
778 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
780 struct frame_info
*frame
, int regnum
,
781 enum lval_type
*lval
)
783 if (!target_has_registers
)
784 error ("No registers.");
786 gdb_assert (FRAME_INIT_SAVED_REGS_P ());
788 /* Normal systems don't optimize out things with register numbers. */
789 if (optimized
!= NULL
)
792 if (addrp
) /* default assumption: not found in memory */
795 /* Note: since the current frame's registers could only have been
796 saved by frames INTERIOR TO the current frame, we skip examining
797 the current frame itself: otherwise, we would be getting the
798 previous frame's registers which were saved by the current frame. */
800 while (frame
&& ((frame
= frame
->next
) != NULL
))
802 if (get_frame_type (frame
) == DUMMY_FRAME
)
804 if (lval
) /* found it in a CALL_DUMMY frame */
807 /* FIXME: cagney/2002-06-26: This should be via the
808 gdbarch_register_read() method so that it, on the fly,
809 constructs either a raw or pseudo register from the raw
811 regcache_raw_read (generic_find_dummy_frame (frame
->pc
,
817 FRAME_INIT_SAVED_REGS (frame
);
818 if (frame
->saved_regs
!= NULL
819 && frame
->saved_regs
[regnum
] != 0)
821 if (lval
) /* found it saved on the stack */
823 if (regnum
== SP_REGNUM
)
825 if (raw_buffer
) /* SP register treated specially */
826 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
827 frame
->saved_regs
[regnum
]);
831 if (addrp
) /* any other register */
832 *addrp
= frame
->saved_regs
[regnum
];
834 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
835 REGISTER_RAW_SIZE (regnum
));
841 /* If we get thru the loop to this point, it means the register was
842 not saved in any frame. Return the actual live-register value. */
844 if (lval
) /* found it in a live register */
845 *lval
= lval_register
;
847 *addrp
= REGISTER_BYTE (regnum
);
849 deprecated_read_register_gen (regnum
, raw_buffer
);
852 /* Determine the frame's type based on its PC. */
854 static enum frame_type
855 frame_type_from_pc (CORE_ADDR pc
)
857 /* FIXME: cagney/2002-11-24: Can't yet directly call
858 pc_in_dummy_frame() as some architectures don't set
859 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
860 latter is implemented by simply calling pc_in_dummy_frame). */
861 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
862 && DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0))
867 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
868 if (PC_IN_SIGTRAMP (pc
, name
))
869 return SIGTRAMP_FRAME
;
875 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
876 Always returns a non-NULL value. */
879 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
881 struct frame_info
*fi
;
883 fi
= frame_obstack_zalloc (sizeof (struct frame_info
));
887 fi
->type
= frame_type_from_pc (pc
);
889 if (INIT_EXTRA_FRAME_INFO_P ())
890 INIT_EXTRA_FRAME_INFO (0, fi
);
892 /* Select/initialize an unwind function. */
893 fi
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, fi
->pc
);
898 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
902 get_next_frame (struct frame_info
*frame
)
907 /* Flush the entire frame cache. */
910 flush_cached_frames (void)
912 /* Since we can't really be sure what the first object allocated was */
913 obstack_free (&frame_cache_obstack
, 0);
914 obstack_init (&frame_cache_obstack
);
916 current_frame
= NULL
; /* Invalidate cache */
918 annotate_frames_invalid ();
921 /* Flush the frame cache, and start a new one if necessary. */
924 reinit_frame_cache (void)
926 flush_cached_frames ();
928 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
929 if (PIDGET (inferior_ptid
) != 0)
931 select_frame (get_current_frame ());
935 /* Create the previous frame using the deprecated methods
936 INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
938 static struct frame_info
*
939 legacy_get_prev_frame (struct frame_info
*next_frame
)
941 CORE_ADDR address
= 0;
942 struct frame_info
*prev
;
945 /* This code only works on normal frames. A sentinel frame, where
946 the level is -1, should never reach this code. */
947 gdb_assert (next_frame
->level
>= 0);
949 /* On some machines it is possible to call a function without
950 setting up a stack frame for it. On these machines, we
951 define this macro to take two args; a frameinfo pointer
952 identifying a frame and a variable to set or clear if it is
953 or isn't leafless. */
955 /* Still don't want to worry about this except on the innermost
956 frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
957 function invocation. */
958 if (next_frame
->level
== 0)
959 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
960 the frame chain, not just the inner most frame! The generic,
961 per-architecture, frame code should handle this and the below
962 should simply be removed. */
963 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
968 /* A frameless inner-most frame. The `FP' (which isn't an
969 architecture frame-pointer register!) of the caller is the same
971 /* FIXME: 2002-11-09: There isn't any reason to special case this
972 edge condition. Instead the per-architecture code should hande
974 address
= get_frame_base (next_frame
);
977 /* Two macros defined in tm.h specify the machine-dependent
978 actions to be performed here.
980 First, get the frame's chain-pointer.
982 If that is zero, the frame is the outermost frame or a leaf
983 called by the outermost frame. This means that if start
984 calls main without a frame, we'll return 0 (which is fine
987 Nope; there's a problem. This also returns when the current
988 routine is a leaf of main. This is unacceptable. We move
989 this to after the ffi test; I'd rather have backtraces from
990 start go curfluy than have an abort called from main not show
992 address
= FRAME_CHAIN (next_frame
);
994 if (!frame_chain_valid (address
, next_frame
))
1000 /* Create an initially zero previous frame. */
1001 prev
= frame_obstack_zalloc (sizeof (struct frame_info
));
1004 next_frame
->prev
= prev
;
1005 prev
->next
= next_frame
;
1006 prev
->frame
= address
;
1007 prev
->level
= next_frame
->level
+ 1;
1008 /* FIXME: cagney/2002-11-18: Should be setting the frame's type
1009 here, before anything else, and not last. Various INIT functions
1010 are full of work-arounds for the frames type not being set
1011 correctly from the word go. Ulgh! */
1012 prev
->type
= NORMAL_FRAME
;
1014 /* This change should not be needed, FIXME! We should determine
1015 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1016 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
1017 express what goes on here.
1019 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
1020 (where the PC is already set up) and here (where it isn't).
1021 DEPRECATED_INIT_FRAME_PC is only called from here, always after
1022 INIT_EXTRA_FRAME_INFO.
1024 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
1025 PC value (which hasn't been set yet). Some other machines appear
1026 to require INIT_EXTRA_FRAME_INFO before they can do
1027 DEPRECATED_INIT_FRAME_PC. Phoo.
1029 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1030 complication to an already overcomplicated part of GDB.
1031 gnu@cygnus.com, 15Sep92.
1033 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1034 INIT_EXTRA_FRAME_INFO, one possible scheme:
1036 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1037 (read_fp ()), read_pc ()). Machines with extra frame info would
1038 do that (or the local equivalent) and then set the extra fields.
1040 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1041 create_new_frame would no longer init extra frame info;
1042 SETUP_ARBITRARY_FRAME would have to do that.
1044 INIT_PREV_FRAME(fromleaf, prev) Replace INIT_EXTRA_FRAME_INFO and
1045 DEPRECATED_INIT_FRAME_PC. This should also return a flag saying
1046 whether to keep the new frame, or whether to discard it, because
1047 on some machines (e.g. mips) it is really awkward to have
1048 FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
1049 no good way to get information deduced in FRAME_CHAIN_VALID into
1050 the extra fields of the new frame). std_frame_pc(fromleaf, prev)
1052 This is the default setting for INIT_PREV_FRAME. It just does
1053 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1054 will call it from INIT_PREV_FRAME (either at the beginning, the
1055 end, or in the middle). Some machines won't use it.
1057 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1059 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1060 reason for things to be this complicated.
1062 The trick is to assume that there is always a frame. Instead of
1063 special casing the inner-most frame, create fake frame
1064 (containing the hardware registers) that is inner to the
1065 user-visible inner-most frame (...) and then unwind from that.
1066 That way architecture code can use use the standard
1067 frame_XX_unwind() functions and not differentiate between the
1068 inner most and any other case.
1070 Since there is always a frame to unwind from, there is always
1071 somewhere (NEXT_FRAME) to store all the info needed to construct
1072 a new (previous) frame without having to first create it. This
1073 means that the convolution below - needing to carefully order a
1074 frame's initialization - isn't needed.
1076 The irony here though, is that FRAME_CHAIN(), at least for a more
1077 up-to-date architecture, always calls FRAME_SAVED_PC(), and
1078 FRAME_SAVED_PC() computes the PC but without first needing the
1079 frame! Instead of the convolution below, we could have simply
1080 called FRAME_SAVED_PC() and been done with it! Note that
1081 FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
1082 function does have somewhere to cache that PC value. */
1084 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1085 prev
->pc
= (DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
, prev
));
1087 if (INIT_EXTRA_FRAME_INFO_P ())
1088 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1090 /* This entry is in the frame queue now, which is good since
1091 FRAME_SAVED_PC may use that queue to figure out its value (see
1092 tm-sparc.h). We want the pc saved in the inferior frame. */
1093 if (DEPRECATED_INIT_FRAME_PC_P ())
1094 prev
->pc
= DEPRECATED_INIT_FRAME_PC (fromleaf
, prev
);
1096 /* If ->frame and ->pc are unchanged, we are in the process of
1097 getting ourselves into an infinite backtrace. Some architectures
1098 check this in FRAME_CHAIN or thereabouts, but it seems like there
1099 is no reason this can't be an architecture-independent check. */
1100 if (prev
->frame
== next_frame
->frame
1101 && prev
->pc
== next_frame
->pc
)
1103 next_frame
->prev
= NULL
;
1104 obstack_free (&frame_cache_obstack
, prev
);
1108 /* Initialize the code used to unwind the frame PREV based on the PC
1109 (and probably other architectural information). The PC lets you
1110 check things like the debug info at that point (dwarf2cfi?) and
1111 use that to decide how the frame should be unwound. */
1112 prev
->unwind
= frame_unwind_find_by_pc (current_gdbarch
, prev
->pc
);
1114 /* NOTE: cagney/2002-11-18: The code segments, found in
1115 create_new_frame and get_prev_frame(), that initializes the
1116 frames type is subtly different. The latter only updates ->type
1117 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1118 get_prev_frame() overriding the frame's type when the INIT code
1119 has previously set it. This is really somewhat bogus. The
1120 initialization, as seen in create_new_frame(), should occur
1121 before the INIT function has been called. */
1122 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1123 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1124 ? DEPRECATED_PC_IN_CALL_DUMMY (prev
->pc
, 0, 0)
1125 : pc_in_dummy_frame (prev
->pc
)))
1126 prev
->type
= DUMMY_FRAME
;
1129 /* FIXME: cagney/2002-11-10: This should be moved to before the
1130 INIT code above so that the INIT code knows what the frame's
1131 type is (in fact, for a [generic] dummy-frame, the type can
1132 be set and then the entire initialization can be skipped.
1133 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1136 find_pc_partial_function (prev
->pc
, &name
, NULL
, NULL
);
1137 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
1138 prev
->type
= SIGTRAMP_FRAME
;
1139 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1140 architectures are forcing the frame's type in INIT so we
1141 don't want to override it here. Remember, NORMAL_FRAME == 0,
1142 so it all works (just :-/). Once this initialization is
1143 moved to the start of this function, all this nastness will
1150 /* Return a structure containing various interesting information
1151 about the frame that called NEXT_FRAME. Returns NULL
1152 if there is no such frame. */
1155 get_prev_frame (struct frame_info
*next_frame
)
1157 struct frame_info
*prev_frame
;
1159 /* Return the inner-most frame, when the caller passes in NULL. */
1160 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1161 caller should have previously obtained a valid frame using
1162 get_selected_frame() and then called this code - only possibility
1163 I can think of is code behaving badly.
1165 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1166 block_innermost_frame(). It does the sequence: frame = NULL;
1167 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1168 it couldn't be written better, I don't know.
1170 NOTE: cagney/2003-01-11: I suspect what is happening is
1171 block_innermost_frame() is, when the target has no state
1172 (registers, memory, ...), still calling this function. The
1173 assumption being that this function will return NULL indicating
1174 that a frame isn't possible, rather than checking that the target
1175 has state and then calling get_current_frame() and
1176 get_prev_frame(). This is a guess mind. */
1177 if (next_frame
== NULL
)
1179 /* NOTE: cagney/2002-11-09: There was a code segment here that
1180 would error out when CURRENT_FRAME was NULL. The comment
1181 that went with it made the claim ...
1183 ``This screws value_of_variable, which just wants a nice
1184 clean NULL return from block_innermost_frame if there are no
1185 frames. I don't think I've ever seen this message happen
1186 otherwise. And returning NULL here is a perfectly legitimate
1189 Per the above, this code shouldn't even be called with a NULL
1191 return current_frame
;
1194 /* There is always a frame. If this assertion fails, suspect that
1195 something should be calling get_selected_frame() or
1196 get_current_frame(). */
1197 gdb_assert (next_frame
!= NULL
);
1199 if (next_frame
->level
>= 0
1200 && !backtrace_below_main
1201 && inside_main_func (get_frame_pc (next_frame
)))
1202 /* Don't unwind past main(), bug always unwind the sentinel frame.
1203 Note, this is done _before_ the frame has been marked as
1204 previously unwound. That way if the user later decides to
1205 allow unwinds past main(), that just happens. */
1208 /* Only try to do the unwind once. */
1209 if (next_frame
->prev_p
)
1210 return next_frame
->prev
;
1211 next_frame
->prev_p
= 1;
1213 /* If we're inside the entry file, it isn't valid. */
1214 /* NOTE: drow/2002-12-25: should there be a way to disable this
1215 check? It assumes a single small entry file, and the way some
1216 debug readers (e.g. dbxread) figure out which object is the
1217 entry file is somewhat hokey. */
1218 /* NOTE: cagney/2003-01-10: If there is a way of disabling this test
1219 then it should probably be moved to before the ->prev_p test,
1221 if (inside_entry_file (get_frame_pc (next_frame
)))
1224 /* If any of the old frame initialization methods are around, use
1225 the legacy get_prev_frame method. Just don't try to unwind a
1226 sentinel frame using that method - it doesn't work. All sentinal
1227 frames use the new unwind code. */
1228 if ((DEPRECATED_INIT_FRAME_PC_P ()
1229 || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
1230 || INIT_EXTRA_FRAME_INFO_P ())
1231 && next_frame
->level
>= 0)
1232 return legacy_get_prev_frame (next_frame
);
1234 /* Allocate the new frame but do not wire it in to the frame chain.
1235 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1236 frame->next to pull some fancy tricks (of course such code is, by
1237 definition, recursive). Try to prevent it.
1239 There is no reason to worry about memory leaks, should the
1240 remainder of the function fail. The allocated memory will be
1241 quickly reclaimed when the frame cache is flushed, and the `we've
1242 been here before' check above will stop repeated memory
1243 allocation calls. */
1244 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1245 prev_frame
->level
= next_frame
->level
+ 1;
1247 /* Try to unwind the PC. If that doesn't work, assume we've reached
1248 the oldest frame and simply return. Is there a better sentinal
1249 value? The unwound PC value is then used to initialize the new
1250 previous frame's type.
1252 Note that the pc-unwind is intentionally performed before the
1253 frame chain. This is ok since, for old targets, both
1254 frame_pc_unwind (nee, FRAME_SAVED_PC) and FRAME_CHAIN()) assume
1255 NEXT_FRAME's data structures have already been initialized (using
1256 INIT_EXTRA_FRAME_INFO) and hence the call order doesn't matter.
1258 By unwinding the PC first, it becomes possible to, in the case of
1259 a dummy frame, avoid also unwinding the frame ID. This is
1260 because (well ignoring the PPC) a dummy frame can be located
1261 using NEXT_FRAME's frame ID. */
1263 prev_frame
->pc
= frame_pc_unwind (next_frame
);
1264 if (prev_frame
->pc
== 0)
1265 /* The allocated PREV_FRAME will be reclaimed when the frame
1266 obstack is next purged. */
1268 prev_frame
->type
= frame_type_from_pc (prev_frame
->pc
);
1270 /* Set the unwind functions based on that identified PC. */
1271 prev_frame
->unwind
= frame_unwind_find_by_pc (current_gdbarch
,
1274 /* FIXME: cagney/2003-01-13: A dummy frame doesn't need to unwind
1275 the frame ID because the frame ID comes from the previous frame.
1276 The other frames do though. True? */
1278 /* FIXME: cagney/2002-12-18: Instead of this hack, should just
1279 save the frame ID directly. */
1280 struct frame_id id
= frame_id_unwind (next_frame
);
1281 if (!frame_id_p (id
))
1283 prev_frame
->frame
= id
.base
;
1287 next_frame
->prev
= prev_frame
;
1288 prev_frame
->next
= next_frame
;
1290 /* FIXME: cagney/2002-01-19: This call will go away. Instead of
1291 initializing extra info, all frames will use the frame_cache
1292 (passed to the unwind functions) to store additional frame info.
1293 Unfortunatly legacy targets can't use legacy_get_prev_frame() to
1294 unwind the sentinel frame and, consequently, are forced to take
1295 this code path and rely on the below call to INIT_EXTR_FRAME_INFO
1296 to initialize the inner-most frame. */
1297 if (INIT_EXTRA_FRAME_INFO_P ())
1299 gdb_assert (prev_frame
->level
== 0);
1300 INIT_EXTRA_FRAME_INFO (0, prev_frame
);
1307 get_frame_pc (struct frame_info
*frame
)
1313 pc_notcurrent (struct frame_info
*frame
)
1315 /* If FRAME is not the innermost frame, that normally means that
1316 FRAME->pc points at the return instruction (which is *after* the
1317 call instruction), and we want to get the line containing the
1318 call (because the call is where the user thinks the program is).
1319 However, if the next frame is either a SIGTRAMP_FRAME or a
1320 DUMMY_FRAME, then the next frame will contain a saved interrupt
1321 PC and such a PC indicates the current (rather than next)
1322 instruction/line, consequently, for such cases, want to get the
1323 line containing fi->pc. */
1324 struct frame_info
*next
= get_next_frame (frame
);
1325 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
1330 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
1332 (*sal
) = find_pc_line (frame
->pc
, pc_notcurrent (frame
));
1335 /* Per "frame.h", return the ``address'' of the frame. Code should
1336 really be using get_frame_id(). */
1338 get_frame_base (struct frame_info
*fi
)
1343 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1344 or -1 for a NULL frame. */
1347 frame_relative_level (struct frame_info
*fi
)
1356 get_frame_type (struct frame_info
*frame
)
1358 /* Some targets still don't use [generic] dummy frames. Catch them
1360 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1361 && deprecated_frame_in_dummy (frame
))
1367 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
1369 /* Arrrg! See comment in "frame.h". */
1373 #ifdef FRAME_FIND_SAVED_REGS
1374 /* XXX - deprecated. This is a compatibility function for targets
1375 that do not yet implement FRAME_INIT_SAVED_REGS. */
1376 /* Find the addresses in which registers are saved in FRAME. */
1379 deprecated_get_frame_saved_regs (struct frame_info
*frame
,
1380 struct frame_saved_regs
*saved_regs_addr
)
1382 if (frame
->saved_regs
== NULL
)
1384 frame
->saved_regs
= (CORE_ADDR
*)
1385 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
1387 if (saved_regs_addr
== NULL
)
1389 struct frame_saved_regs saved_regs
;
1390 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
1391 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
1395 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
1396 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
1401 struct frame_extra_info
*
1402 get_frame_extra_info (struct frame_info
*fi
)
1404 return fi
->extra_info
;
1407 struct frame_extra_info
*
1408 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
1410 fi
->extra_info
= frame_obstack_zalloc (size
);
1411 return fi
->extra_info
;
1415 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
1417 /* See comment in "frame.h". */
1422 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
1424 /* See comment in "frame.h". */
1425 frame
->frame
= base
;
1429 deprecated_set_frame_saved_regs_hack (struct frame_info
*frame
,
1430 CORE_ADDR
*saved_regs
)
1432 frame
->saved_regs
= saved_regs
;
1436 deprecated_set_frame_extra_info_hack (struct frame_info
*frame
,
1437 struct frame_extra_info
*extra_info
)
1439 frame
->extra_info
= extra_info
;
1443 deprecated_set_frame_next_hack (struct frame_info
*fi
,
1444 struct frame_info
*next
)
1450 deprecated_set_frame_prev_hack (struct frame_info
*fi
,
1451 struct frame_info
*prev
)
1457 deprecated_get_frame_context (struct frame_info
*fi
)
1463 deprecated_set_frame_context (struct frame_info
*fi
,
1464 struct context
*context
)
1466 fi
->context
= context
;
1470 deprecated_frame_xmalloc (void)
1472 struct frame_info
*frame
= XMALLOC (struct frame_info
);
1473 memset (frame
, 0, sizeof (struct frame_info
));
1478 deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs
,
1479 long sizeof_extra_info
)
1481 struct frame_info
*frame
= deprecated_frame_xmalloc ();
1482 make_cleanup (xfree
, frame
);
1483 if (sizeof_saved_regs
> 0)
1485 frame
->saved_regs
= xcalloc (1, sizeof_saved_regs
);
1486 make_cleanup (xfree
, frame
->saved_regs
);
1488 if (sizeof_extra_info
> 0)
1490 frame
->extra_info
= xcalloc (1, sizeof_extra_info
);
1491 make_cleanup (xfree
, frame
->extra_info
);
1497 _initialize_frame (void)
1499 obstack_init (&frame_cache_obstack
);
1501 /* FIXME: cagney/2003-01-19: This command needs a rename. Suggest
1502 `set backtrace {past,beyond,...}-main'. Also suggest adding `set
1503 backtrace ...-start' to control backtraces past start. The
1504 problem with `below' is that it stops the `up' command. */
1506 add_setshow_boolean_cmd ("backtrace-below-main", class_obscure
,
1507 &backtrace_below_main
, "\
1508 Set whether backtraces should continue past \"main\".\n\
1509 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1510 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1511 of the stack trace.", "\
1512 Show whether backtraces should continue past \"main\".\n\
1513 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1514 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1515 of the stack trace.",
1516 NULL
, NULL
, &setlist
, &showlist
);