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"
37 /* Return a frame uniq ID that can be used to, later re-find the
41 get_frame_id (struct frame_info *fi, struct frame_id *id)
56 frame_find_by_id (struct frame_id id)
58 struct frame_info *frame;
60 /* ZERO denotes the null frame, let the caller decide what to do
61 about it. Should it instead return get_current_frame()? */
62 if (id.base == 0 && id.pc == 0)
65 for (frame = get_current_frame ();
67 frame = get_prev_frame (frame))
70 get_frame_id (frame, &this);
71 if (INNER_THAN (this.base, id.base))
72 /* ``inner/current < frame < id.base''. Keep looking along
75 if (INNER_THAN (id.base, this.base))
76 /* ``inner/current < id.base < frame''. Oops, gone past it.
79 /* FIXME: cagney/2002-04-21: This isn't sufficient. It should
80 use id.pc / this.pc to check that the two frames belong to
81 the same function. Otherwise we'll do things like match
82 dummy frames or mis-match frameless functions. However,
83 until someone notices, stick with the existing behavour. */
90 frame_pc_unwind (struct frame_info *frame)
92 if (!frame->pc_unwind_cache_p)
94 frame->pc_unwind_cache = frame->pc_unwind (frame, &frame->unwind_cache);
95 frame->pc_unwind_cache_p = 1;
97 return frame->pc_unwind_cache;
101 frame_register_unwind (struct frame_info *frame, int regnum,
102 int *optimizedp, enum lval_type *lvalp,
103 CORE_ADDR *addrp, int *realnump, void *bufferp)
105 struct frame_unwind_cache *cache;
107 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
108 that the value proper does not need to be fetched. */
109 gdb_assert (optimizedp != NULL);
110 gdb_assert (lvalp != NULL);
111 gdb_assert (addrp != NULL);
112 gdb_assert (realnump != NULL);
113 /* gdb_assert (bufferp != NULL); */
115 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
116 special case, there was always an inner frame dedicated to the
117 hardware registers. Unfortunatly, there is too much unwind code
118 around that looks up/down the frame chain while making the
119 assumption that each frame level is using the same unwind code. */
123 /* We're in the inner-most frame, get the value direct from the
126 *lvalp = lval_register;
127 /* ULGH! Code uses the offset into the raw register byte array
128 as a way of identifying a register. */
129 *addrp = REGISTER_BYTE (regnum);
130 /* Should this code test ``register_cached (regnum) < 0'' and do
131 something like set realnum to -1 when the register isn't
135 deprecated_read_register_gen (regnum, bufferp);
139 /* Ask this frame to unwind its register. */
140 frame->register_unwind (frame, &frame->unwind_cache, regnum,
141 optimizedp, lvalp, addrp, realnump, bufferp);
145 frame_register (struct frame_info *frame, int regnum,
146 int *optimizedp, enum lval_type *lvalp,
147 CORE_ADDR *addrp, int *realnump, void *bufferp)
149 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
150 that the value proper does not need to be fetched. */
151 gdb_assert (optimizedp != NULL);
152 gdb_assert (lvalp != NULL);
153 gdb_assert (addrp != NULL);
154 gdb_assert (realnump != NULL);
155 /* gdb_assert (bufferp != NULL); */
157 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
158 of the register in the register cache. It should instead return
159 the REGNUM corresponding to that register. Translate the . */
160 if (GET_SAVED_REGISTER_P ())
162 GET_SAVED_REGISTER (bufferp, optimizedp, addrp, frame, regnum, lvalp);
163 /* Compute the REALNUM if the caller wants it. */
164 if (*lvalp == lval_register)
167 for (regnum = 0; regnum < NUM_REGS + NUM_PSEUDO_REGS; regnum++)
169 if (*addrp == register_offset_hack (current_gdbarch, regnum))
175 internal_error (__FILE__, __LINE__,
176 "Failed to compute the register number corresponding"
177 " to 0x%s", paddr_d (*addrp));
183 /* Reached the the bottom (youngest, inner most) of the frame chain
184 (youngest, inner most) frame, go direct to the hardware register
185 cache (do not pass go, do not try to cache the value, ...). The
186 unwound value would have been cached in frame->next but that
187 doesn't exist. This doesn't matter as the hardware register
188 cache is stopping any unnecessary accesses to the target. */
190 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
191 special case, there was always an inner frame dedicated to the
192 hardware registers. Unfortunatly, there is too much unwind code
193 around that looks up/down the frame chain while making the
194 assumption that each frame level is using the same unwind code. */
197 frame_register_unwind (NULL, regnum, optimizedp, lvalp, addrp, realnump,
200 frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
205 frame_unwind_signed_register (struct frame_info *frame, int regnum,
212 void *buf = alloca (MAX_REGISTER_RAW_SIZE);
213 frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
215 (*val) = extract_signed_integer (buf, REGISTER_VIRTUAL_SIZE (regnum));
219 frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
226 void *buf = alloca (MAX_REGISTER_RAW_SIZE);
227 frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
229 (*val) = extract_unsigned_integer (buf, REGISTER_VIRTUAL_SIZE (regnum));
233 frame_read_unsigned_register (struct frame_info *frame, int regnum,
236 /* NOTE: cagney/2002-10-31: There is a bit of dogma here - there is
237 always a frame. Both this, and the equivalent
238 frame_read_signed_register() function, can only be called with a
239 valid frame. If, for some reason, this function is called
240 without a frame then the problem isn't here, but rather in the
241 caller. It should of first created a frame and then passed that
243 /* NOTE: cagney/2002-10-31: As a side bar, keep in mind that the
244 ``current_frame'' should not be treated as a special case. While
245 ``get_next_frame (current_frame) == NULL'' currently holds, it
246 should, as far as possible, not be relied upon. In the future,
247 ``get_next_frame (current_frame)'' may instead simply return a
248 normal frame object that simply always gets register values from
249 the register cache. Consequently, frame code should try to avoid
250 tests like ``if get_next_frame() == NULL'' and instead just rely
251 on recursive frame calls (like the below code) when manipulating
253 gdb_assert (frame != NULL);
254 frame_unwind_unsigned_register (get_next_frame (frame), regnum, val);
258 frame_read_signed_register (struct frame_info *frame, int regnum,
261 /* See note in frame_read_unsigned_register(). */
262 gdb_assert (frame != NULL);
263 frame_unwind_signed_register (get_next_frame (frame), regnum, val);
267 generic_unwind_get_saved_register (char *raw_buffer,
270 struct frame_info *frame,
272 enum lval_type *lvalp)
277 enum lval_type lvalx;
279 if (!target_has_registers)
280 error ("No registers.");
282 /* Keep things simple, ensure that all the pointers (except valuep)
284 if (optimizedp == NULL)
285 optimizedp = &optimizedx;
291 /* Reached the the bottom (youngest, inner most) of the frame chain
292 (youngest, inner most) frame, go direct to the hardware register
293 cache (do not pass go, do not try to cache the value, ...). The
294 unwound value would have been cached in frame->next but that
295 doesn't exist. This doesn't matter as the hardware register
296 cache is stopping any unnecessary accesses to the target. */
298 /* NOTE: cagney/2002-04-14: It would be nice if, instead of a
299 special case, there was always an inner frame dedicated to the
300 hardware registers. Unfortunatly, there is too much unwind code
301 around that looks up/down the frame chain while making the
302 assumption that each frame level is using the same unwind code. */
305 frame_register_unwind (NULL, regnum, optimizedp, lvalp, addrp, &realnumx,
308 frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
309 &realnumx, raw_buffer);
313 get_saved_register (char *raw_buffer,
316 struct frame_info *frame,
318 enum lval_type *lval)
320 if (GET_SAVED_REGISTER_P ())
322 GET_SAVED_REGISTER (raw_buffer, optimized, addrp, frame, regnum, lval);
325 generic_unwind_get_saved_register (raw_buffer, optimized, addrp, frame,
329 /* frame_register_read ()
331 Find and return the value of REGNUM for the specified stack frame.
332 The number of bytes copied is REGISTER_RAW_SIZE (REGNUM).
334 Returns 0 if the register value could not be found. */
337 frame_register_read (struct frame_info *frame, int regnum, void *myaddr)
343 frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
345 /* FIXME: cagney/2002-05-15: This test, is just bogus.
347 It indicates that the target failed to supply a value for a
348 register because it was "not available" at this time. Problem
349 is, the target still has the register and so get saved_register()
350 may be returning a value saved on the stack. */
352 if (register_cached (regnum) < 0)
353 return 0; /* register value not available */
359 /* Map between a frame register number and its name. A frame register
360 space is a superset of the cooked register space --- it also
361 includes builtin registers. */
364 frame_map_name_to_regnum (const char *name, int len)
368 /* Search register name space. */
369 for (i = 0; i < NUM_REGS + NUM_PSEUDO_REGS; i++)
370 if (REGISTER_NAME (i) && len == strlen (REGISTER_NAME (i))
371 && strncmp (name, REGISTER_NAME (i), len) == 0)
376 /* Try builtin registers. */
377 i = builtin_reg_map_name_to_regnum (name, len);
380 /* A builtin register doesn't fall into the architecture's
382 gdb_assert (i >= NUM_REGS + NUM_PSEUDO_REGS);
390 frame_map_regnum_to_name (int regnum)
394 if (regnum < NUM_REGS + NUM_PSEUDO_REGS)
395 return REGISTER_NAME (regnum);
396 return builtin_reg_map_regnum_to_name (regnum);
399 /* Info about the innermost stack frame (contents of FP register) */
401 static struct frame_info *current_frame;
403 /* Cache for frame addresses already read by gdb. Valid only while
404 inferior is stopped. Control variables for the frame cache should
405 be local to this module. */
407 static struct obstack frame_cache_obstack;
410 frame_obstack_alloc (unsigned long size)
412 return obstack_alloc (&frame_cache_obstack, size);
416 frame_saved_regs_zalloc (struct frame_info *fi)
418 fi->saved_regs = (CORE_ADDR *)
419 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
420 memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);
424 /* Return the innermost (currently executing) stack frame. */
427 get_current_frame (void)
429 if (current_frame == NULL)
431 if (target_has_stack)
432 current_frame = create_new_frame (read_fp (), read_pc ());
436 return current_frame;
440 set_current_frame (struct frame_info *frame)
442 current_frame = frame;
445 /* Return the register saved in the simplistic ``saved_regs'' cache.
446 If the value isn't here AND a value is needed, try the next inner
450 frame_saved_regs_register_unwind (struct frame_info *frame, void **cache,
451 int regnum, int *optimizedp,
452 enum lval_type *lvalp, CORE_ADDR *addrp,
453 int *realnump, void *bufferp)
455 /* There is always a frame at this point. And THIS is the frame
456 we're interested in. */
457 gdb_assert (frame != NULL);
458 /* If we're using generic dummy frames, we'd better not be in a call
459 dummy. (generic_call_dummy_register_unwind ought to have been called
461 gdb_assert (!(DEPRECATED_USE_GENERIC_DUMMY_FRAMES
462 && (get_frame_type (frame) == DUMMY_FRAME)));
464 /* Load the saved_regs register cache. */
465 if (frame->saved_regs == NULL)
466 FRAME_INIT_SAVED_REGS (frame);
468 if (frame->saved_regs != NULL
469 && frame->saved_regs[regnum] != 0)
471 if (regnum == SP_REGNUM)
473 /* SP register treated specially. */
479 store_address (bufferp, REGISTER_RAW_SIZE (regnum),
480 frame->saved_regs[regnum]);
484 /* Any other register is saved in memory, fetch it but cache
485 a local copy of its value. */
487 *lvalp = lval_memory;
488 *addrp = frame->saved_regs[regnum];
493 /* Save each register value, as it is read in, in a
494 frame based cache. */
495 void **regs = (*cache);
498 int sizeof_cache = ((NUM_REGS + NUM_PSEUDO_REGS)
500 regs = frame_obstack_alloc (sizeof_cache);
501 memset (regs, 0, sizeof_cache);
504 if (regs[regnum] == NULL)
507 = frame_obstack_alloc (REGISTER_RAW_SIZE (regnum));
508 read_memory (frame->saved_regs[regnum], regs[regnum],
509 REGISTER_RAW_SIZE (regnum));
511 memcpy (bufferp, regs[regnum], REGISTER_RAW_SIZE (regnum));
513 /* Read the value in from memory. */
514 read_memory (frame->saved_regs[regnum], bufferp,
515 REGISTER_RAW_SIZE (regnum));
522 /* No luck, assume this and the next frame have the same register
523 value. If a value is needed, pass the request on down the chain;
524 otherwise just return an indication that the value is in the same
525 register as the next frame. */
529 *lvalp = lval_register;
535 frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
541 frame_saved_regs_pc_unwind (struct frame_info *frame, void **cache)
543 return FRAME_SAVED_PC (frame);
546 /* Function: get_saved_register
547 Find register number REGNUM relative to FRAME and put its (raw,
548 target format) contents in *RAW_BUFFER.
550 Set *OPTIMIZED if the variable was optimized out (and thus can't be
551 fetched). Note that this is never set to anything other than zero
552 in this implementation.
554 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
555 whether the value was fetched from memory, from a register, or in a
556 strange and non-modifiable way (e.g. a frame pointer which was
557 calculated rather than fetched). We will use not_lval for values
558 fetched from generic dummy frames.
560 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
561 offset into the registers array. If the value is stored in a dummy
562 frame, set *ADDRP to zero.
564 To use this implementation, define a function called
565 "get_saved_register" in your target code, which simply passes all
566 of its arguments to this function.
568 The argument RAW_BUFFER must point to aligned memory. */
571 deprecated_generic_get_saved_register (char *raw_buffer, int *optimized,
573 struct frame_info *frame, int regnum,
574 enum lval_type *lval)
576 if (!target_has_registers)
577 error ("No registers.");
579 /* Normal systems don't optimize out things with register numbers. */
580 if (optimized != NULL)
583 if (addrp) /* default assumption: not found in memory */
586 /* Note: since the current frame's registers could only have been
587 saved by frames INTERIOR TO the current frame, we skip examining
588 the current frame itself: otherwise, we would be getting the
589 previous frame's registers which were saved by the current frame. */
591 while (frame && ((frame = frame->next) != NULL))
593 if (get_frame_type (frame) == DUMMY_FRAME)
595 if (lval) /* found it in a CALL_DUMMY frame */
598 /* FIXME: cagney/2002-06-26: This should be via the
599 gdbarch_register_read() method so that it, on the fly,
600 constructs either a raw or pseudo register from the raw
602 regcache_raw_read (generic_find_dummy_frame (frame->pc,
608 FRAME_INIT_SAVED_REGS (frame);
609 if (frame->saved_regs != NULL
610 && frame->saved_regs[regnum] != 0)
612 if (lval) /* found it saved on the stack */
614 if (regnum == SP_REGNUM)
616 if (raw_buffer) /* SP register treated specially */
617 store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
618 frame->saved_regs[regnum]);
622 if (addrp) /* any other register */
623 *addrp = frame->saved_regs[regnum];
625 read_memory (frame->saved_regs[regnum], raw_buffer,
626 REGISTER_RAW_SIZE (regnum));
632 /* If we get thru the loop to this point, it means the register was
633 not saved in any frame. Return the actual live-register value. */
635 if (lval) /* found it in a live register */
636 *lval = lval_register;
638 *addrp = REGISTER_BYTE (regnum);
640 deprecated_read_register_gen (regnum, raw_buffer);
643 /* Using the PC, select a mechanism for unwinding a frame returning
644 the previous frame. The register unwind function should, on
645 demand, initialize the ->context object. */
648 set_unwind_by_pc (CORE_ADDR pc, CORE_ADDR fp,
649 frame_register_unwind_ftype **unwind_register,
650 frame_pc_unwind_ftype **unwind_pc)
652 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES)
654 /* Still need to set this to something. The ``info frame'' code
655 calls this function to find out where the saved registers are.
656 Hopefully this is robust enough to stop any core dumps and
657 return vaguely correct values.. */
658 *unwind_register = frame_saved_regs_register_unwind;
659 *unwind_pc = frame_saved_regs_pc_unwind;
661 /* FIXME: cagney/2002-11-24: Can't yet directly call
662 pc_in_dummy_frame() as some architectures don't set
663 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
664 latter is implemented by simply calling pc_in_dummy_frame). */
665 else if (PC_IN_CALL_DUMMY (pc, 0, 0))
667 *unwind_register = dummy_frame_register_unwind;
668 *unwind_pc = dummy_frame_pc_unwind;
672 *unwind_register = frame_saved_regs_register_unwind;
673 *unwind_pc = frame_saved_regs_pc_unwind;
677 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
678 Always returns a non-NULL value. */
681 create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
683 struct frame_info *fi;
684 enum frame_type type;
686 fi = (struct frame_info *)
687 obstack_alloc (&frame_cache_obstack,
688 sizeof (struct frame_info));
690 /* Zero all fields by default. */
691 memset (fi, 0, sizeof (struct frame_info));
695 /* NOTE: cagney/2002-11-18: The code segments, found in
696 create_new_frame and get_prev_frame(), that initializes the
697 frames type is subtly different. The latter only updates ->type
698 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
699 get_prev_frame() overriding the frame's type when the INIT code
700 has previously set it. This is really somewhat bogus. The
701 initialization, as seen in create_new_frame(), should occur
702 before the INIT function has been called. */
703 /* FIXME: cagney/2002-11-24: Can't yet directly call
704 pc_in_dummy_frame() as some architectures don't set
705 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
706 latter is implemented by simply calling pc_in_dummy_frame). */
707 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES && PC_IN_CALL_DUMMY (pc, 0, 0))
708 /* NOTE: cagney/2002-11-11: Does this even occure? */
713 find_pc_partial_function (pc, &name, NULL, NULL);
714 if (PC_IN_SIGTRAMP (fi->pc, name))
715 type = SIGTRAMP_FRAME;
721 if (INIT_EXTRA_FRAME_INFO_P ())
722 INIT_EXTRA_FRAME_INFO (0, fi);
724 /* Select/initialize an unwind function. */
725 set_unwind_by_pc (fi->pc, fi->frame, &fi->register_unwind,
731 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
735 get_next_frame (struct frame_info *frame)
740 /* Flush the entire frame cache. */
743 flush_cached_frames (void)
745 /* Since we can't really be sure what the first object allocated was */
746 obstack_free (&frame_cache_obstack, 0);
747 obstack_init (&frame_cache_obstack);
749 current_frame = NULL; /* Invalidate cache */
751 annotate_frames_invalid ();
754 /* Flush the frame cache, and start a new one if necessary. */
757 reinit_frame_cache (void)
759 flush_cached_frames ();
761 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
762 if (PIDGET (inferior_ptid) != 0)
764 select_frame (get_current_frame ());
768 /* Return a structure containing various interesting information
769 about the frame that called NEXT_FRAME. Returns NULL
770 if there is no such frame. */
773 get_prev_frame (struct frame_info *next_frame)
775 CORE_ADDR address = 0;
776 struct frame_info *prev;
779 /* Return the inner-most frame, when the caller passes in NULL. */
780 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
781 caller should have previously obtained a valid frame using
782 get_selected_frame() and then called this code - only possibility
783 I can think of is code behaving badly. */
784 if (next_frame == NULL)
786 /* NOTE: cagney/2002-11-09: There was a code segment here that
787 would error out when CURRENT_FRAME was NULL. The comment
788 that went with it made the claim ...
790 ``This screws value_of_variable, which just wants a nice
791 clean NULL return from block_innermost_frame if there are no
792 frames. I don't think I've ever seen this message happen
793 otherwise. And returning NULL here is a perfectly legitimate
796 Per the above, this code shouldn't even be called with a NULL
798 return current_frame;
801 /* Only try to do the unwind once. */
802 if (next_frame->prev_p)
803 return next_frame->prev;
804 next_frame->prev_p = 1;
806 /* On some machines it is possible to call a function without
807 setting up a stack frame for it. On these machines, we
808 define this macro to take two args; a frameinfo pointer
809 identifying a frame and a variable to set or clear if it is
810 or isn't leafless. */
812 /* Still don't want to worry about this except on the innermost
813 frame. This macro will set FROMLEAF if NEXT_FRAME is a frameless
814 function invocation. */
815 if (next_frame->next == NULL)
816 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
817 the frame chain, not just the inner most frame! The generic,
818 per-architecture, frame code should handle this and the below
819 should simply be removed. */
820 fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame);
825 /* A frameless inner-most frame. The `FP' (which isn't an
826 architecture frame-pointer register!) of the caller is the same
828 /* FIXME: 2002-11-09: There isn't any reason to special case this
829 edge condition. Instead the per-architecture code should hande
831 address = get_frame_base (next_frame);
834 /* Two macros defined in tm.h specify the machine-dependent
835 actions to be performed here.
837 First, get the frame's chain-pointer.
839 If that is zero, the frame is the outermost frame or a leaf
840 called by the outermost frame. This means that if start
841 calls main without a frame, we'll return 0 (which is fine
844 Nope; there's a problem. This also returns when the current
845 routine is a leaf of main. This is unacceptable. We move
846 this to after the ffi test; I'd rather have backtraces from
847 start go curfluy than have an abort called from main not show
849 address = FRAME_CHAIN (next_frame);
851 /* FIXME: cagney/2002-06-08: There should be two tests here.
852 The first would check for a valid frame chain based on a user
853 selectable policy. The default being ``stop at main'' (as
854 implemented by generic_func_frame_chain_valid()). Other
855 policies would be available - stop at NULL, .... The second
856 test, if provided by the target architecture, would check for
857 more exotic cases - most target architectures wouldn't bother
858 with this second case. */
859 if (!FRAME_CHAIN_VALID (address, next_frame))
865 /* Create an initially zero previous frame. */
866 prev = (struct frame_info *)
867 obstack_alloc (&frame_cache_obstack,
868 sizeof (struct frame_info));
869 memset (prev, 0, sizeof (struct frame_info));
872 next_frame->prev = prev;
873 prev->next = next_frame;
874 prev->frame = address;
875 prev->level = next_frame->level + 1;
876 /* FIXME: cagney/2002-11-18: Should be setting the frame's type
877 here, before anything else, and not last. Various INIT functions
878 are full of work-arounds for the frames type not being set
879 correctly from the word go. Ulgh! */
880 prev->type = NORMAL_FRAME;
882 /* This change should not be needed, FIXME! We should determine
883 whether any targets *need* INIT_FRAME_PC to happen after
884 INIT_EXTRA_FRAME_INFO and come up with a simple way to express
887 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
888 (where the PC is already set up) and here (where it isn't).
889 INIT_FRAME_PC is only called from here, always after
890 INIT_EXTRA_FRAME_INFO.
892 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the
893 PC value (which hasn't been set yet). Some other machines appear
894 to require INIT_EXTRA_FRAME_INFO before they can do
897 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
898 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
900 Assuming that some machines need INIT_FRAME_PC after
901 INIT_EXTRA_FRAME_INFO, one possible scheme:
903 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
904 (read_fp ()), read_pc ()). Machines with extra frame info would
905 do that (or the local equivalent) and then set the extra fields.
907 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
908 create_new_frame would no longer init extra frame info;
909 SETUP_ARBITRARY_FRAME would have to do that.
911 INIT_PREV_FRAME(fromleaf, prev) Replace INIT_EXTRA_FRAME_INFO and
912 INIT_FRAME_PC. This should also return a flag saying whether to
913 keep the new frame, or whether to discard it, because on some
914 machines (e.g. mips) it is really awkward to have
915 FRAME_CHAIN_VALID called *before* INIT_EXTRA_FRAME_INFO (there is
916 no good way to get information deduced in FRAME_CHAIN_VALID into
917 the extra fields of the new frame). std_frame_pc(fromleaf, prev)
919 This is the default setting for INIT_PREV_FRAME. It just does
920 what the default INIT_FRAME_PC does. Some machines will call it
921 from INIT_PREV_FRAME (either at the beginning, the end, or in the
922 middle). Some machines won't use it.
924 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
926 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
927 reason for things to be this complicated.
929 The trick is to assume that there is always a frame. Instead of
930 special casing the inner-most frame, create fake frame
931 (containing the hardware registers) that is inner to the
932 user-visible inner-most frame (...) and then unwind from that.
933 That way architecture code can use use the standard
934 frame_XX_unwind() functions and not differentiate between the
935 inner most and any other case.
937 Since there is always a frame to unwind from, there is always
938 somewhere (NEXT_FRAME) to store all the info needed to construct
939 a new (previous) frame without having to first create it. This
940 means that the convolution below - needing to carefully order a
941 frame's initialization - isn't needed.
943 The irony here though, is that FRAME_CHAIN(), at least for a more
944 up-to-date architecture, always calls FRAME_SAVED_PC(), and
945 FRAME_SAVED_PC() computes the PC but without first needing the
946 frame! Instead of the convolution below, we could have simply
947 called FRAME_SAVED_PC() and been done with it! Note that
948 FRAME_SAVED_PC() is being superseed by frame_pc_unwind() and that
949 function does have somewhere to cache that PC value. */
951 INIT_FRAME_PC_FIRST (fromleaf, prev);
953 if (INIT_EXTRA_FRAME_INFO_P ())
954 INIT_EXTRA_FRAME_INFO (fromleaf, prev);
956 /* This entry is in the frame queue now, which is good since
957 FRAME_SAVED_PC may use that queue to figure out its value (see
958 tm-sparc.h). We want the pc saved in the inferior frame. */
959 INIT_FRAME_PC (fromleaf, prev);
961 /* If ->frame and ->pc are unchanged, we are in the process of
962 getting ourselves into an infinite backtrace. Some architectures
963 check this in FRAME_CHAIN or thereabouts, but it seems like there
964 is no reason this can't be an architecture-independent check. */
965 if (prev->frame == next_frame->frame
966 && prev->pc == next_frame->pc)
968 next_frame->prev = NULL;
969 obstack_free (&frame_cache_obstack, prev);
973 /* Initialize the code used to unwind the frame PREV based on the PC
974 (and probably other architectural information). The PC lets you
975 check things like the debug info at that point (dwarf2cfi?) and
976 use that to decide how the frame should be unwound. */
977 set_unwind_by_pc (prev->pc, prev->frame, &prev->register_unwind,
980 /* NOTE: cagney/2002-11-18: The code segments, found in
981 create_new_frame and get_prev_frame(), that initializes the
982 frames type is subtly different. The latter only updates ->type
983 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
984 get_prev_frame() overriding the frame's type when the INIT code
985 has previously set it. This is really somewhat bogus. The
986 initialization, as seen in create_new_frame(), should occur
987 before the INIT function has been called. */
988 /* FIXME: cagney/2002-11-24: Can't yet directly call
989 pc_in_dummy_frame() as some architectures don't set
990 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
991 latter is implemented by simply calling pc_in_dummy_frame). */
992 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
993 && PC_IN_CALL_DUMMY (prev->pc, 0, 0))
994 prev->type = DUMMY_FRAME;
997 /* FIXME: cagney/2002-11-10: This should be moved to before the
998 INIT code above so that the INIT code knows what the frame's
999 type is (in fact, for a [generic] dummy-frame, the type can
1000 be set and then the entire initialization can be skipped.
1001 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1004 find_pc_partial_function (prev->pc, &name, NULL, NULL);
1005 if (PC_IN_SIGTRAMP (prev->pc, name))
1006 prev->type = SIGTRAMP_FRAME;
1007 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1008 architectures are forcing the frame's type in INIT so we
1009 don't want to override it here. Remember, NORMAL_FRAME == 0,
1010 so it all works (just :-/). Once this initialization is
1011 moved to the start of this function, all this nastness will
1019 get_frame_pc (struct frame_info *frame)
1025 pc_notcurrent (struct frame_info *frame)
1027 /* If FRAME is not the innermost frame, that normally means that
1028 FRAME->pc points at the return instruction (which is *after* the
1029 call instruction), and we want to get the line containing the
1030 call (because the call is where the user thinks the program is).
1031 However, if the next frame is either a SIGTRAMP_FRAME or a
1032 DUMMY_FRAME, then the next frame will contain a saved interrupt
1033 PC and such a PC indicates the current (rather than next)
1034 instruction/line, consequently, for such cases, want to get the
1035 line containing fi->pc. */
1036 struct frame_info *next = get_next_frame (frame);
1037 int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME);
1042 find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal)
1044 (*sal) = find_pc_line (frame->pc, pc_notcurrent (frame));
1047 /* Per "frame.h", return the ``address'' of the frame. Code should
1048 really be using get_frame_id(). */
1050 get_frame_base (struct frame_info *fi)
1055 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1056 or -1 for a NULL frame. */
1059 frame_relative_level (struct frame_info *fi)
1068 get_frame_type (struct frame_info *frame)
1070 /* Some targets still don't use [generic] dummy frames. Catch them
1072 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1073 && deprecated_frame_in_dummy (frame))
1079 deprecated_set_frame_type (struct frame_info *frame, enum frame_type type)
1081 /* Arrrg! See comment in "frame.h". */
1085 #ifdef FRAME_FIND_SAVED_REGS
1086 /* XXX - deprecated. This is a compatibility function for targets
1087 that do not yet implement FRAME_INIT_SAVED_REGS. */
1088 /* Find the addresses in which registers are saved in FRAME. */
1091 get_frame_saved_regs (struct frame_info *frame,
1092 struct frame_saved_regs *saved_regs_addr)
1094 if (frame->saved_regs == NULL)
1096 frame->saved_regs = (CORE_ADDR *)
1097 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
1099 if (saved_regs_addr == NULL)
1101 struct frame_saved_regs saved_regs;
1102 FRAME_FIND_SAVED_REGS (frame, saved_regs);
1103 memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS);
1107 FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr);
1108 memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS);
1114 _initialize_frame (void)
1116 obstack_init (&frame_cache_obstack);