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, 2004 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 "user-regs.h"
32 #include "gdb_obstack.h"
33 #include "dummy-frame.h"
34 #include "sentinel-frame.h"
38 #include "frame-unwind.h"
39 #include "frame-base.h"
43 /* We keep a cache of stack frames, each of which is a "struct
44 frame_info". The innermost one gets allocated (in
45 wait_for_inferior) each time the inferior stops; current_frame
46 points to it. Additional frames get allocated (in get_prev_frame)
47 as needed, and are chained through the next and prev fields. Any
48 time that the frame cache becomes invalid (most notably when we
49 execute something, but also if we change how we interpret the
50 frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
51 which reads new symbols)), we should call reinit_frame_cache. */
55 /* Level of this frame. The inner-most (youngest) frame is at level
56 0. As you move towards the outer-most (oldest) frame, the level
57 increases. This is a cached value. It could just as easily be
58 computed by counting back from the selected frame to the inner
60 /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
61 reserved to indicate a bogus frame - one that has been created
62 just to keep GDB happy (GDB always needs a frame). For the
63 moment leave this as speculation. */
66 /* The frame's type. */
67 /* FIXME: cagney/2003-04-02: Should instead be returning
68 ->unwind->type. Unfortunately, legacy code is still explicitly
69 setting the type using the method deprecated_set_frame_type.
70 Eliminate that method and this field can be eliminated. */
73 /* For each register, address of where it was saved on entry to the
74 frame, or zero if it was not saved on entry to this frame. This
75 includes special registers such as pc and fp saved in special
76 ways in the stack frame. The SP_REGNUM is even more special, the
77 address here is the sp for the previous frame, not the address
78 where the sp was saved. */
79 /* Allocated by frame_saved_regs_zalloc () which is called /
80 initialized by DEPRECATED_FRAME_INIT_SAVED_REGS(). */
81 CORE_ADDR
*saved_regs
; /*NUM_REGS + NUM_PSEUDO_REGS*/
83 /* Anything extra for this structure that may have been defined in
84 the machine dependent files. */
85 /* Allocated by frame_extra_info_zalloc () which is called /
86 initialized by DEPRECATED_INIT_EXTRA_FRAME_INFO */
87 struct frame_extra_info
*extra_info
;
89 /* The frame's low-level unwinder and corresponding cache. The
90 low-level unwinder is responsible for unwinding register values
91 for the previous frame. The low-level unwind methods are
92 selected based on the presence, or otherwize, of register unwind
93 information such as CFI. */
95 const struct frame_unwind
*unwind
;
97 /* Cached copy of the previous frame's resume address. */
103 /* Cached copy of the previous frame's function address. */
110 /* This frame's ID. */
114 struct frame_id value
;
117 /* The frame's high-level base methods, and corresponding cache.
118 The high level base methods are selected based on the frame's
120 const struct frame_base
*base
;
123 /* Pointers to the next (down, inner, younger) and previous (up,
124 outer, older) frame_info's in the frame cache. */
125 struct frame_info
*next
; /* down, inner, younger */
127 struct frame_info
*prev
; /* up, outer, older */
130 /* Flag to control debugging. */
132 static int frame_debug
;
134 /* Flag to indicate whether backtraces should stop at main et.al. */
136 static int backtrace_past_main
;
137 static unsigned int backtrace_limit
= UINT_MAX
;
141 fprint_frame_id (struct ui_file
*file
, struct frame_id id
)
143 fprintf_unfiltered (file
, "{stack=0x%s,code=0x%s,special=0x%s}",
144 paddr_nz (id
.stack_addr
),
145 paddr_nz (id
.code_addr
),
146 paddr_nz (id
.special_addr
));
150 fprint_frame_type (struct ui_file
*file
, enum frame_type type
)
155 fprintf_unfiltered (file
, "UNKNOWN_FRAME");
158 fprintf_unfiltered (file
, "NORMAL_FRAME");
161 fprintf_unfiltered (file
, "DUMMY_FRAME");
164 fprintf_unfiltered (file
, "SIGTRAMP_FRAME");
167 fprintf_unfiltered (file
, "<unknown type>");
173 fprint_frame (struct ui_file
*file
, struct frame_info
*fi
)
177 fprintf_unfiltered (file
, "<NULL frame>");
180 fprintf_unfiltered (file
, "{");
181 fprintf_unfiltered (file
, "level=%d", fi
->level
);
182 fprintf_unfiltered (file
, ",");
183 fprintf_unfiltered (file
, "type=");
184 fprint_frame_type (file
, fi
->type
);
185 fprintf_unfiltered (file
, ",");
186 fprintf_unfiltered (file
, "unwind=");
187 if (fi
->unwind
!= NULL
)
188 gdb_print_host_address (fi
->unwind
, file
);
190 fprintf_unfiltered (file
, "<unknown>");
191 fprintf_unfiltered (file
, ",");
192 fprintf_unfiltered (file
, "pc=");
193 if (fi
->next
!= NULL
&& fi
->next
->prev_pc
.p
)
194 fprintf_unfiltered (file
, "0x%s", paddr_nz (fi
->next
->prev_pc
.value
));
196 fprintf_unfiltered (file
, "<unknown>");
197 fprintf_unfiltered (file
, ",");
198 fprintf_unfiltered (file
, "id=");
200 fprint_frame_id (file
, fi
->this_id
.value
);
202 fprintf_unfiltered (file
, "<unknown>");
203 fprintf_unfiltered (file
, ",");
204 fprintf_unfiltered (file
, "func=");
205 if (fi
->next
!= NULL
&& fi
->next
->prev_func
.p
)
206 fprintf_unfiltered (file
, "0x%s", paddr_nz (fi
->next
->prev_func
.addr
));
208 fprintf_unfiltered (file
, "<unknown>");
209 fprintf_unfiltered (file
, "}");
212 /* Return a frame uniq ID that can be used to, later, re-find the
216 get_frame_id (struct frame_info
*fi
)
220 return null_frame_id
;
224 gdb_assert (!legacy_frame_p (current_gdbarch
));
226 fprintf_unfiltered (gdb_stdlog
, "{ get_frame_id (fi=%d) ",
228 /* Find the unwinder. */
229 if (fi
->unwind
== NULL
)
231 fi
->unwind
= frame_unwind_find_by_frame (fi
->next
);
232 /* FIXME: cagney/2003-04-02: Rather than storing the frame's
233 type in the frame, the unwinder's type should be returned
234 directly. Unfortunately, legacy code, called by
235 legacy_get_prev_frame, explicitly set the frames type
236 using the method deprecated_set_frame_type(). */
237 fi
->type
= fi
->unwind
->type
;
239 /* Find THIS frame's ID. */
240 fi
->unwind
->this_id (fi
->next
, &fi
->prologue_cache
, &fi
->this_id
.value
);
244 fprintf_unfiltered (gdb_stdlog
, "-> ");
245 fprint_frame_id (gdb_stdlog
, fi
->this_id
.value
);
246 fprintf_unfiltered (gdb_stdlog
, " }\n");
249 return fi
->this_id
.value
;
252 const struct frame_id null_frame_id
; /* All zeros. */
255 frame_id_build_special (CORE_ADDR stack_addr
, CORE_ADDR code_addr
,
256 CORE_ADDR special_addr
)
259 id
.stack_addr
= stack_addr
;
260 id
.code_addr
= code_addr
;
261 id
.special_addr
= special_addr
;
266 frame_id_build (CORE_ADDR stack_addr
, CORE_ADDR code_addr
)
268 return frame_id_build_special (stack_addr
, code_addr
, 0);
272 frame_id_p (struct frame_id l
)
275 /* The .code can be NULL but the .stack cannot. */
276 p
= (l
.stack_addr
!= 0);
279 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_p (l=");
280 fprint_frame_id (gdb_stdlog
, l
);
281 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", p
);
287 frame_id_eq (struct frame_id l
, struct frame_id r
)
290 if (l
.stack_addr
== 0 || r
.stack_addr
== 0)
291 /* Like a NaN, if either ID is invalid, the result is false. */
293 else if (l
.stack_addr
!= r
.stack_addr
)
294 /* If .stack addresses are different, the frames are different. */
296 else if (l
.code_addr
== 0 || r
.code_addr
== 0)
297 /* A zero code addr is a wild card, always succeed. */
299 else if (l
.code_addr
!= r
.code_addr
)
300 /* If .code addresses are different, the frames are different. */
302 else if (l
.special_addr
== 0 || r
.special_addr
== 0)
303 /* A zero special addr is a wild card (or unused), always succeed. */
305 else if (l
.special_addr
== r
.special_addr
)
306 /* Frames are equal. */
313 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_eq (l=");
314 fprint_frame_id (gdb_stdlog
, l
);
315 fprintf_unfiltered (gdb_stdlog
, ",r=");
316 fprint_frame_id (gdb_stdlog
, r
);
317 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", eq
);
323 frame_id_inner (struct frame_id l
, struct frame_id r
)
326 if (l
.stack_addr
== 0 || r
.stack_addr
== 0)
327 /* Like NaN, any operation involving an invalid ID always fails. */
330 /* Only return non-zero when strictly inner than. Note that, per
331 comment in "frame.h", there is some fuzz here. Frameless
332 functions are not strictly inner than (same .stack but
333 different .code and/or .special address). */
334 inner
= INNER_THAN (l
.stack_addr
, r
.stack_addr
);
337 fprintf_unfiltered (gdb_stdlog
, "{ frame_id_inner (l=");
338 fprint_frame_id (gdb_stdlog
, l
);
339 fprintf_unfiltered (gdb_stdlog
, ",r=");
340 fprint_frame_id (gdb_stdlog
, r
);
341 fprintf_unfiltered (gdb_stdlog
, ") -> %d }\n", inner
);
347 frame_find_by_id (struct frame_id id
)
349 struct frame_info
*frame
;
351 /* ZERO denotes the null frame, let the caller decide what to do
352 about it. Should it instead return get_current_frame()? */
353 if (!frame_id_p (id
))
356 for (frame
= get_current_frame ();
358 frame
= get_prev_frame (frame
))
360 struct frame_id
this = get_frame_id (frame
);
361 if (frame_id_eq (id
, this))
362 /* An exact match. */
364 if (frame_id_inner (id
, this))
367 /* Either, we're not yet gone far enough out along the frame
368 chain (inner(this,id), or we're comparing frameless functions
369 (same .base, different .func, no test available). Struggle
370 on until we've definitly gone to far. */
376 frame_pc_unwind (struct frame_info
*this_frame
)
378 if (!this_frame
->prev_pc
.p
)
381 if (gdbarch_unwind_pc_p (current_gdbarch
))
383 /* The right way. The `pure' way. The one true way. This
384 method depends solely on the register-unwind code to
385 determine the value of registers in THIS frame, and hence
386 the value of this frame's PC (resume address). A typical
387 implementation is no more than:
389 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
390 return extract_unsigned_integer (buf, size of ISA_PC_REGNUM);
392 Note: this method is very heavily dependent on a correct
393 register-unwind implementation, it pays to fix that
394 method first; this method is frame type agnostic, since
395 it only deals with register values, it works with any
396 frame. This is all in stark contrast to the old
397 FRAME_SAVED_PC which would try to directly handle all the
398 different ways that a PC could be unwound. */
399 pc
= gdbarch_unwind_pc (current_gdbarch
, this_frame
);
401 else if (this_frame
->level
< 0)
403 /* FIXME: cagney/2003-03-06: Old code and and a sentinel
404 frame. Do like was always done. Fetch the PC's value
405 direct from the global registers array (via read_pc).
406 This assumes that this frame belongs to the current
407 global register cache. The assumption is dangerous. */
410 else if (DEPRECATED_FRAME_SAVED_PC_P ())
412 /* FIXME: cagney/2003-03-06: Old code, but not a sentinel
413 frame. Do like was always done. Note that this method,
414 unlike unwind_pc(), tries to handle all the different
415 frame cases directly. It fails. */
416 pc
= DEPRECATED_FRAME_SAVED_PC (this_frame
);
419 internal_error (__FILE__
, __LINE__
, "No gdbarch_unwind_pc method");
420 this_frame
->prev_pc
.value
= pc
;
421 this_frame
->prev_pc
.p
= 1;
423 fprintf_unfiltered (gdb_stdlog
,
424 "{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n",
426 paddr_nz (this_frame
->prev_pc
.value
));
428 return this_frame
->prev_pc
.value
;
432 frame_func_unwind (struct frame_info
*fi
)
434 if (!fi
->prev_func
.p
)
436 /* Make certain that this, and not the adjacent, function is
438 CORE_ADDR addr_in_block
= frame_unwind_address_in_block (fi
);
440 fi
->prev_func
.addr
= get_pc_function_start (addr_in_block
);
442 fprintf_unfiltered (gdb_stdlog
,
443 "{ frame_func_unwind (fi=%d) -> 0x%s }\n",
444 fi
->level
, paddr_nz (fi
->prev_func
.addr
));
446 return fi
->prev_func
.addr
;
450 get_frame_func (struct frame_info
*fi
)
452 return frame_func_unwind (fi
->next
);
456 do_frame_unwind_register (void *src
, int regnum
, void *buf
)
458 frame_unwind_register (src
, regnum
, buf
);
463 frame_pop (struct frame_info
*this_frame
)
465 struct regcache
*scratch_regcache
;
466 struct cleanup
*cleanups
;
468 if (DEPRECATED_POP_FRAME_P ())
470 /* A legacy architecture that has implemented a custom pop
471 function. All new architectures should instead be using the
472 generic code below. */
473 DEPRECATED_POP_FRAME
;
477 /* Make a copy of all the register values unwound from this
478 frame. Save them in a scratch buffer so that there isn't a
479 race betweening trying to extract the old values from the
480 current_regcache while, at the same time writing new values
481 into that same cache. */
482 struct regcache
*scratch
= regcache_xmalloc (current_gdbarch
);
483 struct cleanup
*cleanups
= make_cleanup_regcache_xfree (scratch
);
484 regcache_save (scratch
, do_frame_unwind_register
, this_frame
);
485 /* FIXME: cagney/2003-03-16: It should be possible to tell the
486 target's register cache that it is about to be hit with a
487 burst register transfer and that the sequence of register
488 writes should be batched. The pair target_prepare_to_store()
489 and target_store_registers() kind of suggest this
490 functionality. Unfortunately, they don't implement it. Their
491 lack of a formal definition can lead to targets writing back
492 bogus values (arguably a bug in the target code mind). */
493 /* Now copy those saved registers into the current regcache.
494 Here, regcache_cpy() calls regcache_restore(). */
495 regcache_cpy (current_regcache
, scratch
);
496 do_cleanups (cleanups
);
498 /* We've made right mess of GDB's local state, just discard
500 flush_cached_frames ();
504 frame_register_unwind (struct frame_info
*frame
, int regnum
,
505 int *optimizedp
, enum lval_type
*lvalp
,
506 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
508 struct frame_unwind_cache
*cache
;
512 fprintf_unfiltered (gdb_stdlog
, "\
513 { frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
514 frame
->level
, regnum
,
515 frame_map_regnum_to_name (frame
, regnum
));
518 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
519 that the value proper does not need to be fetched. */
520 gdb_assert (optimizedp
!= NULL
);
521 gdb_assert (lvalp
!= NULL
);
522 gdb_assert (addrp
!= NULL
);
523 gdb_assert (realnump
!= NULL
);
524 /* gdb_assert (bufferp != NULL); */
526 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
527 is broken. There is always a frame. If there, for some reason,
528 isn't, there is some pretty busted code as it should have
529 detected the problem before calling here. */
530 gdb_assert (frame
!= NULL
);
532 /* Find the unwinder. */
533 if (frame
->unwind
== NULL
)
535 frame
->unwind
= frame_unwind_find_by_frame (frame
->next
);
536 /* FIXME: cagney/2003-04-02: Rather than storing the frame's
537 type in the frame, the unwinder's type should be returned
538 directly. Unfortunately, legacy code, called by
539 legacy_get_prev_frame, explicitly set the frames type using
540 the method deprecated_set_frame_type(). */
541 frame
->type
= frame
->unwind
->type
;
544 /* Ask this frame to unwind its register. See comment in
545 "frame-unwind.h" for why NEXT frame and this unwind cace are
547 frame
->unwind
->prev_register (frame
->next
, &frame
->prologue_cache
, regnum
,
548 optimizedp
, lvalp
, addrp
, realnump
, bufferp
);
552 fprintf_unfiltered (gdb_stdlog
, "->");
553 fprintf_unfiltered (gdb_stdlog
, " *optimizedp=%d", (*optimizedp
));
554 fprintf_unfiltered (gdb_stdlog
, " *lvalp=%d", (int) (*lvalp
));
555 fprintf_unfiltered (gdb_stdlog
, " *addrp=0x%s", paddr_nz ((*addrp
)));
556 fprintf_unfiltered (gdb_stdlog
, " *bufferp=");
558 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
562 const unsigned char *buf
= bufferp
;
563 fprintf_unfiltered (gdb_stdlog
, "[");
564 for (i
= 0; i
< register_size (current_gdbarch
, regnum
); i
++)
565 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
566 fprintf_unfiltered (gdb_stdlog
, "]");
568 fprintf_unfiltered (gdb_stdlog
, " }\n");
573 frame_register (struct frame_info
*frame
, int regnum
,
574 int *optimizedp
, enum lval_type
*lvalp
,
575 CORE_ADDR
*addrp
, int *realnump
, void *bufferp
)
577 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
578 that the value proper does not need to be fetched. */
579 gdb_assert (optimizedp
!= NULL
);
580 gdb_assert (lvalp
!= NULL
);
581 gdb_assert (addrp
!= NULL
);
582 gdb_assert (realnump
!= NULL
);
583 /* gdb_assert (bufferp != NULL); */
585 /* Ulgh! Old code that, for lval_register, sets ADDRP to the offset
586 of the register in the register cache. It should instead return
587 the REGNUM corresponding to that register. Translate the . */
588 if (DEPRECATED_GET_SAVED_REGISTER_P ())
590 DEPRECATED_GET_SAVED_REGISTER (bufferp
, optimizedp
, addrp
, frame
,
592 /* Compute the REALNUM if the caller wants it. */
593 if (*lvalp
== lval_register
)
596 for (regnum
= 0; regnum
< NUM_REGS
+ NUM_PSEUDO_REGS
; regnum
++)
598 if (*addrp
== register_offset_hack (current_gdbarch
, regnum
))
604 internal_error (__FILE__
, __LINE__
,
605 "Failed to compute the register number corresponding"
606 " to 0x%s", paddr_d (*addrp
));
612 /* Obtain the register value by unwinding the register from the next
613 (more inner frame). */
614 gdb_assert (frame
!= NULL
&& frame
->next
!= NULL
);
615 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
620 frame_unwind_register (struct frame_info
*frame
, int regnum
, void *buf
)
626 frame_register_unwind (frame
, regnum
, &optimized
, &lval
, &addr
,
631 get_frame_register (struct frame_info
*frame
,
632 int regnum
, void *buf
)
634 frame_unwind_register (frame
->next
, regnum
, buf
);
638 frame_unwind_register_signed (struct frame_info
*frame
, int regnum
)
640 char buf
[MAX_REGISTER_SIZE
];
641 frame_unwind_register (frame
, regnum
, buf
);
642 return extract_signed_integer (buf
, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum
));
646 get_frame_register_signed (struct frame_info
*frame
, int regnum
)
648 return frame_unwind_register_signed (frame
->next
, regnum
);
652 frame_unwind_register_unsigned (struct frame_info
*frame
, int regnum
)
654 char buf
[MAX_REGISTER_SIZE
];
655 frame_unwind_register (frame
, regnum
, buf
);
656 return extract_unsigned_integer (buf
, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum
));
660 get_frame_register_unsigned (struct frame_info
*frame
, int regnum
)
662 return frame_unwind_register_unsigned (frame
->next
, regnum
);
666 frame_unwind_unsigned_register (struct frame_info
*frame
, int regnum
,
669 char buf
[MAX_REGISTER_SIZE
];
670 frame_unwind_register (frame
, regnum
, buf
);
671 (*val
) = extract_unsigned_integer (buf
, DEPRECATED_REGISTER_VIRTUAL_SIZE (regnum
));
675 put_frame_register (struct frame_info
*frame
, int regnum
, const void *buf
)
677 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
682 frame_register (frame
, regnum
, &optim
, &lval
, &addr
, &realnum
, NULL
);
684 error ("Attempt to assign to a value that was optimized out.");
689 /* FIXME: write_memory doesn't yet take constant buffers.
691 char tmp
[MAX_REGISTER_SIZE
];
692 memcpy (tmp
, buf
, register_size (gdbarch
, regnum
));
693 write_memory (addr
, tmp
, register_size (gdbarch
, regnum
));
697 regcache_cooked_write (current_regcache
, realnum
, buf
);
700 error ("Attempt to assign to an unmodifiable value.");
704 /* frame_register_read ()
706 Find and return the value of REGNUM for the specified stack frame.
707 The number of bytes copied is DEPRECATED_REGISTER_RAW_SIZE
710 Returns 0 if the register value could not be found. */
713 frame_register_read (struct frame_info
*frame
, int regnum
, void *myaddr
)
719 frame_register (frame
, regnum
, &optimized
, &lval
, &addr
, &realnum
, myaddr
);
721 /* FIXME: cagney/2002-05-15: This test, is just bogus.
723 It indicates that the target failed to supply a value for a
724 register because it was "not available" at this time. Problem
725 is, the target still has the register and so get saved_register()
726 may be returning a value saved on the stack. */
728 if (register_cached (regnum
) < 0)
729 return 0; /* register value not available */
735 /* Map between a frame register number and its name. A frame register
736 space is a superset of the cooked register space --- it also
737 includes builtin registers. */
740 frame_map_name_to_regnum (struct frame_info
*frame
, const char *name
, int len
)
742 return user_reg_map_name_to_regnum (get_frame_arch (frame
), name
, len
);
746 frame_map_regnum_to_name (struct frame_info
*frame
, int regnum
)
748 return user_reg_map_regnum_to_name (get_frame_arch (frame
), regnum
);
751 /* Create a sentinel frame. */
753 static struct frame_info
*
754 create_sentinel_frame (struct regcache
*regcache
)
756 struct frame_info
*frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
757 frame
->type
= NORMAL_FRAME
;
759 /* Explicitly initialize the sentinel frame's cache. Provide it
760 with the underlying regcache. In the future additional
761 information, such as the frame's thread will be added. */
762 frame
->prologue_cache
= sentinel_frame_cache (regcache
);
763 /* For the moment there is only one sentinel frame implementation. */
764 frame
->unwind
= sentinel_frame_unwind
;
765 /* Link this frame back to itself. The frame is self referential
766 (the unwound PC is the same as the pc), so make it so. */
768 /* Make the sentinel frame's ID valid, but invalid. That way all
769 comparisons with it should fail. */
770 frame
->this_id
.p
= 1;
771 frame
->this_id
.value
= null_frame_id
;
774 fprintf_unfiltered (gdb_stdlog
, "{ create_sentinel_frame (...) -> ");
775 fprint_frame (gdb_stdlog
, frame
);
776 fprintf_unfiltered (gdb_stdlog
, " }\n");
781 /* Info about the innermost stack frame (contents of FP register) */
783 static struct frame_info
*current_frame
;
785 /* Cache for frame addresses already read by gdb. Valid only while
786 inferior is stopped. Control variables for the frame cache should
787 be local to this module. */
789 static struct obstack frame_cache_obstack
;
792 frame_obstack_zalloc (unsigned long size
)
794 void *data
= obstack_alloc (&frame_cache_obstack
, size
);
795 memset (data
, 0, size
);
800 frame_saved_regs_zalloc (struct frame_info
*fi
)
802 fi
->saved_regs
= (CORE_ADDR
*)
803 frame_obstack_zalloc (SIZEOF_FRAME_SAVED_REGS
);
804 return fi
->saved_regs
;
808 deprecated_get_frame_saved_regs (struct frame_info
*fi
)
810 return fi
->saved_regs
;
813 /* Return the innermost (currently executing) stack frame. This is
814 split into two functions. The function unwind_to_current_frame()
815 is wrapped in catch exceptions so that, even when the unwind of the
816 sentinel frame fails, the function still returns a stack frame. */
819 unwind_to_current_frame (struct ui_out
*ui_out
, void *args
)
821 struct frame_info
*frame
= get_prev_frame (args
);
822 /* A sentinel frame can fail to unwind, eg, because it's PC value
823 lands in somewhere like start. */
826 current_frame
= frame
;
831 get_current_frame (void)
833 /* First check, and report, the lack of registers. Having GDB
834 report "No stack!" or "No memory" when the target doesn't even
835 have registers is very confusing. Besides, "printcmd.exp"
836 explicitly checks that ``print $pc'' with no registers prints "No
838 if (!target_has_registers
)
839 error ("No registers.");
840 if (!target_has_stack
)
842 if (!target_has_memory
)
843 error ("No memory.");
844 if (current_frame
== NULL
)
846 struct frame_info
*sentinel_frame
=
847 create_sentinel_frame (current_regcache
);
848 if (catch_exceptions (uiout
, unwind_to_current_frame
, sentinel_frame
,
849 NULL
, RETURN_MASK_ERROR
) != 0)
851 /* Oops! Fake a current frame? Is this useful? It has a PC
852 of zero, for instance. */
853 current_frame
= sentinel_frame
;
856 return current_frame
;
859 /* The "selected" stack frame is used by default for local and arg
860 access. May be zero, for no selected frame. */
862 struct frame_info
*deprecated_selected_frame
;
864 /* Return the selected frame. Always non-null (unless there isn't an
865 inferior sufficient for creating a frame) in which case an error is
869 get_selected_frame (void)
871 if (deprecated_selected_frame
== NULL
)
872 /* Hey! Don't trust this. It should really be re-finding the
873 last selected frame of the currently selected thread. This,
874 though, is better than nothing. */
875 select_frame (get_current_frame ());
876 /* There is always a frame. */
877 gdb_assert (deprecated_selected_frame
!= NULL
);
878 return deprecated_selected_frame
;
881 /* This is a variant of get_selected_frame which can be called when
882 the inferior does not have a frame; in that case it will return
883 NULL instead of calling error (). */
886 deprecated_safe_get_selected_frame (void)
888 if (!target_has_registers
|| !target_has_stack
|| !target_has_memory
)
890 return get_selected_frame ();
893 /* Select frame FI (or NULL - to invalidate the current frame). */
896 select_frame (struct frame_info
*fi
)
900 deprecated_selected_frame
= fi
;
901 /* NOTE: cagney/2002-05-04: FI can be NULL. This occures when the
902 frame is being invalidated. */
903 if (selected_frame_level_changed_hook
)
904 selected_frame_level_changed_hook (frame_relative_level (fi
));
906 /* FIXME: kseitz/2002-08-28: It would be nice to call
907 selected_frame_level_changed_event right here, but due to limitations
908 in the current interfaces, we would end up flooding UIs with events
909 because select_frame is used extensively internally.
911 Once we have frame-parameterized frame (and frame-related) commands,
912 the event notification can be moved here, since this function will only
913 be called when the users selected frame is being changed. */
915 /* Ensure that symbols for this frame are read in. Also, determine the
916 source language of this frame, and switch to it if desired. */
919 /* We retrieve the frame's symtab by using the frame PC. However
920 we cannot use the frame pc as is, because it usually points to
921 the instruction following the "call", which is sometimes the
922 first instruction of another function. So we rely on
923 get_frame_address_in_block() which provides us with a PC which
924 is guaranteed to be inside the frame's code block. */
925 s
= find_pc_symtab (get_frame_address_in_block (fi
));
927 && s
->language
!= current_language
->la_language
928 && s
->language
!= language_unknown
929 && language_mode
== language_mode_auto
)
931 set_language (s
->language
);
936 /* Return the register saved in the simplistic ``saved_regs'' cache.
937 If the value isn't here AND a value is needed, try the next inner
941 legacy_saved_regs_prev_register (struct frame_info
*next_frame
,
942 void **this_prologue_cache
,
943 int regnum
, int *optimizedp
,
944 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
945 int *realnump
, void *bufferp
)
947 /* HACK: New code is passed the next frame and this cache.
948 Unfortunately, old code expects this frame. Since this is a
949 backward compatibility hack, cheat by walking one level along the
950 prologue chain to the frame the old code expects.
952 Do not try this at home. Professional driver, closed course. */
953 struct frame_info
*frame
= next_frame
->prev
;
954 gdb_assert (frame
!= NULL
);
956 if (deprecated_get_frame_saved_regs (frame
) == NULL
)
958 /* If nothing's initialized the saved regs, do it now. */
959 gdb_assert (DEPRECATED_FRAME_INIT_SAVED_REGS_P ());
960 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
961 gdb_assert (deprecated_get_frame_saved_regs (frame
) != NULL
);
964 if (deprecated_get_frame_saved_regs (frame
) != NULL
965 && deprecated_get_frame_saved_regs (frame
)[regnum
] != 0)
967 if (regnum
== SP_REGNUM
)
969 /* SP register treated specially. */
975 /* NOTE: cagney/2003-05-09: In-lined store_address with
976 it's body - store_unsigned_integer. */
977 store_unsigned_integer (bufferp
, DEPRECATED_REGISTER_RAW_SIZE (regnum
),
978 deprecated_get_frame_saved_regs (frame
)[regnum
]);
982 /* Any other register is saved in memory, fetch it but cache
983 a local copy of its value. */
985 *lvalp
= lval_memory
;
986 *addrp
= deprecated_get_frame_saved_regs (frame
)[regnum
];
991 /* Save each register value, as it is read in, in a
992 frame based cache. */
993 void **regs
= (*this_prologue_cache
);
996 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
998 regs
= frame_obstack_zalloc (sizeof_cache
);
999 (*this_prologue_cache
) = regs
;
1001 if (regs
[regnum
] == NULL
)
1004 = frame_obstack_zalloc (DEPRECATED_REGISTER_RAW_SIZE (regnum
));
1005 read_memory (deprecated_get_frame_saved_regs (frame
)[regnum
], regs
[regnum
],
1006 DEPRECATED_REGISTER_RAW_SIZE (regnum
));
1008 memcpy (bufferp
, regs
[regnum
], DEPRECATED_REGISTER_RAW_SIZE (regnum
));
1010 /* Read the value in from memory. */
1011 read_memory (deprecated_get_frame_saved_regs (frame
)[regnum
], bufferp
,
1012 DEPRECATED_REGISTER_RAW_SIZE (regnum
));
1019 /* No luck. Assume this and the next frame have the same register
1020 value. Pass the unwind request down the frame chain to the next
1021 frame. Hopefully that frame will find the register's location. */
1022 frame_register_unwind (next_frame
, regnum
, optimizedp
, lvalp
, addrp
,
1027 legacy_saved_regs_this_id (struct frame_info
*next_frame
,
1028 void **this_prologue_cache
,
1029 struct frame_id
*id
)
1031 /* A developer is trying to bring up a new architecture, help them
1032 by providing a default unwinder that refuses to unwind anything
1033 (the ID is always NULL). In the case of legacy code,
1034 legacy_get_prev_frame() will have previously set ->this_id.p, so
1035 this code won't be called. */
1036 (*id
) = null_frame_id
;
1039 const struct frame_unwind legacy_saved_regs_unwinder
= {
1040 /* Not really. It gets overridden by legacy_get_prev_frame. */
1042 legacy_saved_regs_this_id
,
1043 legacy_saved_regs_prev_register
1045 const struct frame_unwind
*legacy_saved_regs_unwind
= &legacy_saved_regs_unwinder
;
1048 /* Function: deprecated_generic_get_saved_register
1049 Find register number REGNUM relative to FRAME and put its (raw,
1050 target format) contents in *RAW_BUFFER.
1052 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1053 fetched). Note that this is never set to anything other than zero
1054 in this implementation.
1056 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1057 whether the value was fetched from memory, from a register, or in a
1058 strange and non-modifiable way (e.g. a frame pointer which was
1059 calculated rather than fetched). We will use not_lval for values
1060 fetched from generic dummy frames.
1062 Set *ADDRP to the address, either in memory or as a
1063 DEPRECATED_REGISTER_BYTE offset into the registers array. If the
1064 value is stored in a dummy frame, set *ADDRP to zero.
1066 The argument RAW_BUFFER must point to aligned memory. */
1069 deprecated_generic_get_saved_register (char *raw_buffer
, int *optimized
,
1071 struct frame_info
*frame
, int regnum
,
1072 enum lval_type
*lval
)
1074 if (!target_has_registers
)
1075 error ("No registers.");
1077 /* Normal systems don't optimize out things with register numbers. */
1078 if (optimized
!= NULL
)
1081 if (addrp
) /* default assumption: not found in memory */
1084 /* Note: since the current frame's registers could only have been
1085 saved by frames INTERIOR TO the current frame, we skip examining
1086 the current frame itself: otherwise, we would be getting the
1087 previous frame's registers which were saved by the current frame. */
1091 for (frame
= get_next_frame (frame
);
1092 frame_relative_level (frame
) >= 0;
1093 frame
= get_next_frame (frame
))
1095 if (get_frame_type (frame
) == DUMMY_FRAME
)
1097 if (lval
) /* found it in a CALL_DUMMY frame */
1100 /* FIXME: cagney/2002-06-26: This should be via the
1101 gdbarch_register_read() method so that it, on the
1102 fly, constructs either a raw or pseudo register
1103 from the raw register cache. */
1105 (deprecated_find_dummy_frame_regcache (get_frame_pc (frame
),
1106 get_frame_base (frame
)),
1107 regnum
, raw_buffer
);
1111 DEPRECATED_FRAME_INIT_SAVED_REGS (frame
);
1112 if (deprecated_get_frame_saved_regs (frame
) != NULL
1113 && deprecated_get_frame_saved_regs (frame
)[regnum
] != 0)
1115 if (lval
) /* found it saved on the stack */
1116 *lval
= lval_memory
;
1117 if (regnum
== SP_REGNUM
)
1119 if (raw_buffer
) /* SP register treated specially */
1120 /* NOTE: cagney/2003-05-09: In-line store_address
1121 with it's body - store_unsigned_integer. */
1122 store_unsigned_integer (raw_buffer
,
1123 DEPRECATED_REGISTER_RAW_SIZE (regnum
),
1124 deprecated_get_frame_saved_regs (frame
)[regnum
]);
1128 if (addrp
) /* any other register */
1129 *addrp
= deprecated_get_frame_saved_regs (frame
)[regnum
];
1131 read_memory (deprecated_get_frame_saved_regs (frame
)[regnum
], raw_buffer
,
1132 DEPRECATED_REGISTER_RAW_SIZE (regnum
));
1139 /* If we get thru the loop to this point, it means the register was
1140 not saved in any frame. Return the actual live-register value. */
1142 if (lval
) /* found it in a live register */
1143 *lval
= lval_register
;
1145 *addrp
= DEPRECATED_REGISTER_BYTE (regnum
);
1147 deprecated_read_register_gen (regnum
, raw_buffer
);
1150 /* Determine the frame's type based on its PC. */
1152 static enum frame_type
1153 frame_type_from_pc (CORE_ADDR pc
)
1155 /* FIXME: cagney/2002-11-24: Can't yet directly call
1156 pc_in_dummy_frame() as some architectures don't set
1157 PC_IN_CALL_DUMMY() to generic_pc_in_call_dummy() (remember the
1158 latter is implemented by simply calling pc_in_dummy_frame). */
1159 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1160 && DEPRECATED_PC_IN_CALL_DUMMY (pc
, 0, 0))
1165 find_pc_partial_function (pc
, &name
, NULL
, NULL
);
1166 if (PC_IN_SIGTRAMP (pc
, name
))
1167 return SIGTRAMP_FRAME
;
1169 return NORMAL_FRAME
;
1173 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
1174 Always returns a non-NULL value. */
1177 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
1179 struct frame_info
*fi
;
1183 fprintf_unfiltered (gdb_stdlog
,
1184 "{ create_new_frame (addr=0x%s, pc=0x%s) ",
1185 paddr_nz (addr
), paddr_nz (pc
));
1188 fi
= frame_obstack_zalloc (sizeof (struct frame_info
));
1190 fi
->next
= create_sentinel_frame (current_regcache
);
1192 /* Select/initialize both the unwind function and the frame's type
1194 fi
->unwind
= frame_unwind_find_by_frame (fi
->next
);
1195 if (fi
->unwind
->type
!= UNKNOWN_FRAME
)
1196 fi
->type
= fi
->unwind
->type
;
1198 fi
->type
= frame_type_from_pc (pc
);
1201 deprecated_update_frame_base_hack (fi
, addr
);
1202 deprecated_update_frame_pc_hack (fi
, pc
);
1204 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1205 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, fi
);
1209 fprintf_unfiltered (gdb_stdlog
, "-> ");
1210 fprint_frame (gdb_stdlog
, fi
);
1211 fprintf_unfiltered (gdb_stdlog
, " }\n");
1217 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
1218 innermost frame). Be careful to not fall off the bottom of the
1219 frame chain and onto the sentinel frame. */
1222 get_next_frame (struct frame_info
*this_frame
)
1224 if (this_frame
->level
> 0)
1225 return this_frame
->next
;
1230 /* Flush the entire frame cache. */
1233 flush_cached_frames (void)
1235 /* Since we can't really be sure what the first object allocated was */
1236 obstack_free (&frame_cache_obstack
, 0);
1237 obstack_init (&frame_cache_obstack
);
1239 current_frame
= NULL
; /* Invalidate cache */
1240 select_frame (NULL
);
1241 annotate_frames_invalid ();
1243 fprintf_unfiltered (gdb_stdlog
, "{ flush_cached_frames () }\n");
1246 /* Flush the frame cache, and start a new one if necessary. */
1249 reinit_frame_cache (void)
1251 flush_cached_frames ();
1253 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
1254 if (PIDGET (inferior_ptid
) != 0)
1256 select_frame (get_current_frame ());
1260 /* Create the previous frame using the deprecated methods
1261 INIT_EXTRA_INFO, INIT_FRAME_PC and INIT_FRAME_PC_FIRST. */
1263 static struct frame_info
*
1264 legacy_get_prev_frame (struct frame_info
*this_frame
)
1266 CORE_ADDR address
= 0;
1267 struct frame_info
*prev
;
1270 /* Don't frame_debug print legacy_get_prev_frame() here, just
1271 confuses the output. */
1273 /* Allocate the new frame.
1275 There is no reason to worry about memory leaks, should the
1276 remainder of the function fail. The allocated memory will be
1277 quickly reclaimed when the frame cache is flushed, and the `we've
1278 been here before' check, in get_prev_frame will stop repeated
1279 memory allocation calls. */
1280 prev
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1281 prev
->level
= this_frame
->level
+ 1;
1283 /* Do not completely wire it in to the frame chain. Some (bad) code
1284 in INIT_FRAME_EXTRA_INFO tries to look along frame->prev to pull
1285 some fancy tricks (of course such code is, by definition,
1288 On the other hand, methods, such as get_frame_pc() and
1289 get_frame_base() rely on being able to walk along the frame
1290 chain. Make certain that at least they work by providing that
1291 link. Of course things manipulating prev can't go back. */
1292 prev
->next
= this_frame
;
1294 /* NOTE: cagney/2002-11-18: Should have been correctly setting the
1295 frame's type here, before anything else, and not last, at the
1296 bottom of this function. The various
1297 DEPRECATED_INIT_EXTRA_FRAME_INFO, DEPRECATED_INIT_FRAME_PC,
1298 DEPRECATED_INIT_FRAME_PC_FIRST and
1299 DEPRECATED_FRAME_INIT_SAVED_REGS methods are full of work-arounds
1300 that handle the frame not being correctly set from the start.
1301 Unfortunately those same work-arounds rely on the type defaulting
1302 to NORMAL_FRAME. Ulgh! The new frame code does not have this
1304 prev
->type
= UNKNOWN_FRAME
;
1306 /* A legacy frame's ID is always computed here. Mark it as valid. */
1307 prev
->this_id
.p
= 1;
1309 /* Handle sentinel frame unwind as a special case. */
1310 if (this_frame
->level
< 0)
1312 /* Try to unwind the PC. If that doesn't work, assume we've reached
1313 the oldest frame and simply return. Is there a better sentinal
1314 value? The unwound PC value is then used to initialize the new
1315 previous frame's type.
1317 Note that the pc-unwind is intentionally performed before the
1318 frame chain. This is ok since, for old targets, both
1319 frame_pc_unwind (nee, DEPRECATED_FRAME_SAVED_PC) and
1320 DEPRECATED_FRAME_CHAIN()) assume THIS_FRAME's data structures
1321 have already been initialized (using
1322 DEPRECATED_INIT_EXTRA_FRAME_INFO) and hence the call order
1325 By unwinding the PC first, it becomes possible to, in the case of
1326 a dummy frame, avoid also unwinding the frame ID. This is
1327 because (well ignoring the PPC) a dummy frame can be located
1328 using THIS_FRAME's frame ID. */
1330 deprecated_update_frame_pc_hack (prev
, frame_pc_unwind (this_frame
));
1331 if (get_frame_pc (prev
) == 0)
1333 /* The allocated PREV_FRAME will be reclaimed when the frame
1334 obstack is next purged. */
1337 fprintf_unfiltered (gdb_stdlog
, "-> ");
1338 fprint_frame (gdb_stdlog
, NULL
);
1339 fprintf_unfiltered (gdb_stdlog
,
1340 " // unwound legacy PC zero }\n");
1345 /* Set the unwind functions based on that identified PC. Ditto
1346 for the "type" but strongly prefer the unwinder's frame type. */
1347 prev
->unwind
= frame_unwind_find_by_frame (prev
->next
);
1348 if (prev
->unwind
->type
== UNKNOWN_FRAME
)
1349 prev
->type
= frame_type_from_pc (get_frame_pc (prev
));
1351 prev
->type
= prev
->unwind
->type
;
1353 /* Find the prev's frame's ID. */
1354 if (prev
->type
== DUMMY_FRAME
1355 && gdbarch_unwind_dummy_id_p (current_gdbarch
))
1357 /* When unwinding a normal frame, the stack structure is
1358 determined by analyzing the frame's function's code (be
1359 it using brute force prologue analysis, or the dwarf2
1360 CFI). In the case of a dummy frame, that simply isn't
1361 possible. The The PC is either the program entry point,
1362 or some random address on the stack. Trying to use that
1363 PC to apply standard frame ID unwind techniques is just
1364 asking for trouble. */
1365 /* Use an architecture specific method to extract the prev's
1366 dummy ID from the next frame. Note that this method uses
1367 frame_register_unwind to obtain the register values
1368 needed to determine the dummy frame's ID. */
1369 prev
->this_id
.value
= gdbarch_unwind_dummy_id (current_gdbarch
,
1374 /* We're unwinding a sentinel frame, the PC of which is
1375 pointing at a stack dummy. Fake up the dummy frame's ID
1376 using the same sequence as is found a traditional
1377 unwinder. Once all architectures supply the
1378 unwind_dummy_id method, this code can go away. */
1379 prev
->this_id
.value
= frame_id_build (deprecated_read_fp (),
1383 /* Check that the unwound ID is valid. */
1384 if (!frame_id_p (prev
->this_id
.value
))
1388 fprintf_unfiltered (gdb_stdlog
, "-> ");
1389 fprint_frame (gdb_stdlog
, NULL
);
1390 fprintf_unfiltered (gdb_stdlog
,
1391 " // unwound legacy ID invalid }\n");
1396 /* Check that the new frame isn't inner to (younger, below,
1397 next) the old frame. If that happens the frame unwind is
1399 /* FIXME: cagney/2003-02-25: Ignore the sentinel frame since
1400 that doesn't have a valid frame ID. Should instead set the
1401 sentinel frame's frame ID to a `sentinel'. Leave it until
1402 after the switch to storing the frame ID, instead of the
1403 frame base, in the frame object. */
1406 this_frame
->prev
= prev
;
1408 /* FIXME: cagney/2002-01-19: This call will go away. Instead of
1409 initializing extra info, all frames will use the frame_cache
1410 (passed to the unwind functions) to store additional frame
1411 info. Unfortunately legacy targets can't use
1412 legacy_get_prev_frame() to unwind the sentinel frame and,
1413 consequently, are forced to take this code path and rely on
1414 the below call to DEPRECATED_INIT_EXTRA_FRAME_INFO to
1415 initialize the inner-most frame. */
1416 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1418 DEPRECATED_INIT_EXTRA_FRAME_INFO (0, prev
);
1421 if (prev
->type
== NORMAL_FRAME
)
1422 prev
->this_id
.value
.code_addr
1423 = get_pc_function_start (prev
->this_id
.value
.code_addr
);
1427 fprintf_unfiltered (gdb_stdlog
, "-> ");
1428 fprint_frame (gdb_stdlog
, prev
);
1429 fprintf_unfiltered (gdb_stdlog
, " } // legacy innermost frame\n");
1434 /* This code only works on normal frames. A sentinel frame, where
1435 the level is -1, should never reach this code. */
1436 gdb_assert (this_frame
->level
>= 0);
1438 /* On some machines it is possible to call a function without
1439 setting up a stack frame for it. On these machines, we
1440 define this macro to take two args; a frameinfo pointer
1441 identifying a frame and a variable to set or clear if it is
1442 or isn't leafless. */
1444 /* Still don't want to worry about this except on the innermost
1445 frame. This macro will set FROMLEAF if THIS_FRAME is a frameless
1446 function invocation. */
1447 if (this_frame
->level
== 0)
1448 /* FIXME: 2002-11-09: Frameless functions can occure anywhere in
1449 the frame chain, not just the inner most frame! The generic,
1450 per-architecture, frame code should handle this and the below
1451 should simply be removed. */
1452 fromleaf
= (DEPRECATED_FRAMELESS_FUNCTION_INVOCATION_P ()
1453 && DEPRECATED_FRAMELESS_FUNCTION_INVOCATION (this_frame
));
1458 /* A frameless inner-most frame. The `FP' (which isn't an
1459 architecture frame-pointer register!) of the caller is the same
1461 /* FIXME: 2002-11-09: There isn't any reason to special case this
1462 edge condition. Instead the per-architecture code should hande
1464 /* FIXME: cagney/2003-06-16: This returns the inner most stack
1465 address for the previous frame, that, however, is wrong. It
1466 should be the inner most stack address for the previous to
1467 previous frame. This is because it is the previous to previous
1468 frame's innermost stack address that is constant through out
1469 the lifetime of the previous frame (trust me :-). */
1470 address
= get_frame_base (this_frame
);
1473 /* Two macros defined in tm.h specify the machine-dependent
1474 actions to be performed here.
1476 First, get the frame's chain-pointer.
1478 If that is zero, the frame is the outermost frame or a leaf
1479 called by the outermost frame. This means that if start
1480 calls main without a frame, we'll return 0 (which is fine
1483 Nope; there's a problem. This also returns when the current
1484 routine is a leaf of main. This is unacceptable. We move
1485 this to after the ffi test; I'd rather have backtraces from
1486 start go curfluy than have an abort called from main not show
1488 if (DEPRECATED_FRAME_CHAIN_P ())
1489 address
= DEPRECATED_FRAME_CHAIN (this_frame
);
1492 /* Someone is part way through coverting an old architecture
1493 to the new frame code. Implement FRAME_CHAIN the way the
1495 /* Find PREV frame's unwinder. */
1496 prev
->unwind
= frame_unwind_find_by_frame (this_frame
->next
);
1497 /* FIXME: cagney/2003-04-02: Rather than storing the frame's
1498 type in the frame, the unwinder's type should be returned
1499 directly. Unfortunately, legacy code, called by
1500 legacy_get_prev_frame, explicitly set the frames type
1501 using the method deprecated_set_frame_type(). */
1502 prev
->type
= prev
->unwind
->type
;
1503 /* Find PREV frame's ID. */
1504 prev
->unwind
->this_id (this_frame
,
1505 &prev
->prologue_cache
,
1506 &prev
->this_id
.value
);
1507 prev
->this_id
.p
= 1;
1508 address
= prev
->this_id
.value
.stack_addr
;
1511 if (!legacy_frame_chain_valid (address
, this_frame
))
1515 fprintf_unfiltered (gdb_stdlog
, "-> ");
1516 fprint_frame (gdb_stdlog
, NULL
);
1517 fprintf_unfiltered (gdb_stdlog
,
1518 " // legacy frame chain invalid }\n");
1527 fprintf_unfiltered (gdb_stdlog
, "-> ");
1528 fprint_frame (gdb_stdlog
, NULL
);
1529 fprintf_unfiltered (gdb_stdlog
,
1530 " // legacy frame chain NULL }\n");
1535 /* Link in the already allocated prev frame. */
1536 this_frame
->prev
= prev
;
1537 deprecated_update_frame_base_hack (prev
, address
);
1539 /* This change should not be needed, FIXME! We should determine
1540 whether any targets *need* DEPRECATED_INIT_FRAME_PC to happen
1541 after DEPRECATED_INIT_EXTRA_FRAME_INFO and come up with a simple
1542 way to express what goes on here.
1544 DEPRECATED_INIT_EXTRA_FRAME_INFO is called from two places:
1545 create_new_frame (where the PC is already set up) and here (where
1546 it isn't). DEPRECATED_INIT_FRAME_PC is only called from here,
1547 always after DEPRECATED_INIT_EXTRA_FRAME_INFO.
1549 The catch is the MIPS, where DEPRECATED_INIT_EXTRA_FRAME_INFO
1550 requires the PC value (which hasn't been set yet). Some other
1551 machines appear to require DEPRECATED_INIT_EXTRA_FRAME_INFO
1552 before they can do DEPRECATED_INIT_FRAME_PC. Phoo.
1554 We shouldn't need DEPRECATED_INIT_FRAME_PC_FIRST to add more
1555 complication to an already overcomplicated part of GDB.
1556 gnu@cygnus.com, 15Sep92.
1558 Assuming that some machines need DEPRECATED_INIT_FRAME_PC after
1559 DEPRECATED_INIT_EXTRA_FRAME_INFO, one possible scheme:
1561 SETUP_INNERMOST_FRAME(): Default version is just create_new_frame
1562 (deprecated_read_fp ()), read_pc ()). Machines with extra frame
1563 info would do that (or the local equivalent) and then set the
1566 SETUP_ARBITRARY_FRAME(argc, argv): Only change here is that
1567 create_new_frame would no longer init extra frame info;
1568 SETUP_ARBITRARY_FRAME would have to do that.
1570 INIT_PREV_FRAME(fromleaf, prev) Replace
1571 DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC.
1572 This should also return a flag saying whether to keep the new
1573 frame, or whether to discard it, because on some machines (e.g.
1574 mips) it is really awkward to have DEPRECATED_FRAME_CHAIN_VALID
1575 called BEFORE DEPRECATED_INIT_EXTRA_FRAME_INFO (there is no good
1576 way to get information deduced in DEPRECATED_FRAME_CHAIN_VALID
1577 into the extra fields of the new frame). std_frame_pc(fromleaf,
1580 This is the default setting for INIT_PREV_FRAME. It just does
1581 what the default DEPRECATED_INIT_FRAME_PC does. Some machines
1582 will call it from INIT_PREV_FRAME (either at the beginning, the
1583 end, or in the middle). Some machines won't use it.
1585 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
1587 /* NOTE: cagney/2002-11-09: Just ignore the above! There is no
1588 reason for things to be this complicated.
1590 The trick is to assume that there is always a frame. Instead of
1591 special casing the inner-most frame, create fake frame
1592 (containing the hardware registers) that is inner to the
1593 user-visible inner-most frame (...) and then unwind from that.
1594 That way architecture code can use use the standard
1595 frame_XX_unwind() functions and not differentiate between the
1596 inner most and any other case.
1598 Since there is always a frame to unwind from, there is always
1599 somewhere (THIS_FRAME) to store all the info needed to construct
1600 a new (previous) frame without having to first create it. This
1601 means that the convolution below - needing to carefully order a
1602 frame's initialization - isn't needed.
1604 The irony here though, is that DEPRECATED_FRAME_CHAIN(), at least
1605 for a more up-to-date architecture, always calls
1606 FRAME_SAVED_PC(), and FRAME_SAVED_PC() computes the PC but
1607 without first needing the frame! Instead of the convolution
1608 below, we could have simply called FRAME_SAVED_PC() and been done
1609 with it! Note that FRAME_SAVED_PC() is being superseed by
1610 frame_pc_unwind() and that function does have somewhere to cache
1613 if (DEPRECATED_INIT_FRAME_PC_FIRST_P ())
1614 deprecated_update_frame_pc_hack (prev
,
1615 DEPRECATED_INIT_FRAME_PC_FIRST (fromleaf
,
1618 if (DEPRECATED_INIT_EXTRA_FRAME_INFO_P ())
1619 DEPRECATED_INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
1621 /* This entry is in the frame queue now, which is good since
1622 FRAME_SAVED_PC may use that queue to figure out its value (see
1623 tm-sparc.h). We want the pc saved in the inferior frame. */
1624 if (DEPRECATED_INIT_FRAME_PC_P ())
1625 deprecated_update_frame_pc_hack (prev
,
1626 DEPRECATED_INIT_FRAME_PC (fromleaf
,
1629 /* If ->frame and ->pc are unchanged, we are in the process of
1630 getting ourselves into an infinite backtrace. Some architectures
1631 check this in DEPRECATED_FRAME_CHAIN or thereabouts, but it seems
1632 like there is no reason this can't be an architecture-independent
1634 if (get_frame_base (prev
) == get_frame_base (this_frame
)
1635 && get_frame_pc (prev
) == get_frame_pc (this_frame
))
1637 this_frame
->prev
= NULL
;
1638 obstack_free (&frame_cache_obstack
, prev
);
1641 fprintf_unfiltered (gdb_stdlog
, "-> ");
1642 fprint_frame (gdb_stdlog
, NULL
);
1643 fprintf_unfiltered (gdb_stdlog
,
1644 " // legacy this.id == prev.id }\n");
1649 /* Initialize the code used to unwind the frame PREV based on the PC
1650 (and probably other architectural information). The PC lets you
1651 check things like the debug info at that point (dwarf2cfi?) and
1652 use that to decide how the frame should be unwound.
1654 If there isn't a FRAME_CHAIN, the code above will have already
1656 if (prev
->unwind
== NULL
)
1657 prev
->unwind
= frame_unwind_find_by_frame (prev
->next
);
1659 /* If the unwinder provides a frame type, use it. Otherwize
1660 continue on to that heuristic mess. */
1661 if (prev
->unwind
->type
!= UNKNOWN_FRAME
)
1663 prev
->type
= prev
->unwind
->type
;
1664 if (prev
->type
== NORMAL_FRAME
)
1665 /* FIXME: cagney/2003-06-16: would get_frame_pc() be better? */
1666 prev
->this_id
.value
.code_addr
1667 = get_pc_function_start (prev
->this_id
.value
.code_addr
);
1670 fprintf_unfiltered (gdb_stdlog
, "-> ");
1671 fprint_frame (gdb_stdlog
, prev
);
1672 fprintf_unfiltered (gdb_stdlog
, " } // legacy with unwound type\n");
1677 /* NOTE: cagney/2002-11-18: The code segments, found in
1678 create_new_frame and get_prev_frame(), that initializes the
1679 frames type is subtly different. The latter only updates ->type
1680 when it encounters a SIGTRAMP_FRAME or DUMMY_FRAME. This stops
1681 get_prev_frame() overriding the frame's type when the INIT code
1682 has previously set it. This is really somewhat bogus. The
1683 initialization, as seen in create_new_frame(), should occur
1684 before the INIT function has been called. */
1685 if (DEPRECATED_USE_GENERIC_DUMMY_FRAMES
1686 && (DEPRECATED_PC_IN_CALL_DUMMY_P ()
1687 ? DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (prev
), 0, 0)
1688 : pc_in_dummy_frame (get_frame_pc (prev
))))
1689 prev
->type
= DUMMY_FRAME
;
1692 /* FIXME: cagney/2002-11-10: This should be moved to before the
1693 INIT code above so that the INIT code knows what the frame's
1694 type is (in fact, for a [generic] dummy-frame, the type can
1695 be set and then the entire initialization can be skipped.
1696 Unforunatly, its the INIT code that sets the PC (Hmm, catch
1699 find_pc_partial_function (get_frame_pc (prev
), &name
, NULL
, NULL
);
1700 if (PC_IN_SIGTRAMP (get_frame_pc (prev
), name
))
1701 prev
->type
= SIGTRAMP_FRAME
;
1702 /* FIXME: cagney/2002-11-11: Leave prev->type alone. Some
1703 architectures are forcing the frame's type in INIT so we
1704 don't want to override it here. Remember, NORMAL_FRAME == 0,
1705 so it all works (just :-/). Once this initialization is
1706 moved to the start of this function, all this nastness will
1710 if (prev
->type
== NORMAL_FRAME
)
1711 prev
->this_id
.value
.code_addr
1712 = get_pc_function_start (prev
->this_id
.value
.code_addr
);
1716 fprintf_unfiltered (gdb_stdlog
, "-> ");
1717 fprint_frame (gdb_stdlog
, prev
);
1718 fprintf_unfiltered (gdb_stdlog
, " } // legacy with confused type\n");
1724 /* Return a structure containing various interesting information
1725 about the frame that called THIS_FRAME. Returns NULL
1726 if there is no such frame.
1728 This function tests some target-independent conditions that should
1729 terminate the frame chain, such as unwinding past main(). It
1730 should not contain any target-dependent tests, such as checking
1731 whether the program-counter is zero. */
1734 get_prev_frame (struct frame_info
*this_frame
)
1736 struct frame_info
*prev_frame
;
1740 fprintf_unfiltered (gdb_stdlog
, "{ get_prev_frame (this_frame=");
1741 if (this_frame
!= NULL
)
1742 fprintf_unfiltered (gdb_stdlog
, "%d", this_frame
->level
);
1744 fprintf_unfiltered (gdb_stdlog
, "<NULL>");
1745 fprintf_unfiltered (gdb_stdlog
, ") ");
1748 /* Return the inner-most frame, when the caller passes in NULL. */
1749 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1750 caller should have previously obtained a valid frame using
1751 get_selected_frame() and then called this code - only possibility
1752 I can think of is code behaving badly.
1754 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1755 block_innermost_frame(). It does the sequence: frame = NULL;
1756 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1757 it couldn't be written better, I don't know.
1759 NOTE: cagney/2003-01-11: I suspect what is happening is
1760 block_innermost_frame() is, when the target has no state
1761 (registers, memory, ...), still calling this function. The
1762 assumption being that this function will return NULL indicating
1763 that a frame isn't possible, rather than checking that the target
1764 has state and then calling get_current_frame() and
1765 get_prev_frame(). This is a guess mind. */
1766 if (this_frame
== NULL
)
1768 /* NOTE: cagney/2002-11-09: There was a code segment here that
1769 would error out when CURRENT_FRAME was NULL. The comment
1770 that went with it made the claim ...
1772 ``This screws value_of_variable, which just wants a nice
1773 clean NULL return from block_innermost_frame if there are no
1774 frames. I don't think I've ever seen this message happen
1775 otherwise. And returning NULL here is a perfectly legitimate
1778 Per the above, this code shouldn't even be called with a NULL
1780 return current_frame
;
1783 /* There is always a frame. If this assertion fails, suspect that
1784 something should be calling get_selected_frame() or
1785 get_current_frame(). */
1786 gdb_assert (this_frame
!= NULL
);
1788 /* Make sure we pass an address within THIS_FRAME's code block to
1789 inside_main_func. Otherwise, we might stop unwinding at a
1790 function which has a call instruction as its last instruction if
1791 that function immediately precedes main(). */
1792 if (this_frame
->level
>= 0
1793 && !backtrace_past_main
1794 && inside_main_func (get_frame_address_in_block (this_frame
)))
1795 /* Don't unwind past main(), bug always unwind the sentinel frame.
1796 Note, this is done _before_ the frame has been marked as
1797 previously unwound. That way if the user later decides to
1798 allow unwinds past main(), that just happens. */
1801 fprintf_unfiltered (gdb_stdlog
, "-> NULL // inside main func }\n");
1805 if (this_frame
->level
> backtrace_limit
)
1807 error ("Backtrace limit of %d exceeded", backtrace_limit
);
1810 /* If we're already inside the entry function for the main objfile,
1811 then it isn't valid. Don't apply this test to a dummy frame -
1812 dummy frame PC's typically land in the entry func. Don't apply
1813 this test to the sentinel frame. Sentinel frames should always
1814 be allowed to unwind. */
1815 /* NOTE: cagney/2003-02-25: Don't enable until someone has found
1816 hard evidence that this is needed. */
1817 /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func - wasn't
1818 checking for "main" in the minimal symbols. With that fixed
1819 asm-source tests now stop in "main" instead of halting the
1820 backtrace in wierd and wonderful ways somewhere inside the entry
1821 file. Suspect that deprecated_inside_entry_file and
1822 inside_entry_func tests were added to work around that (now
1824 /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
1825 suggested having the inside_entry_func test use the
1826 inside_main_func msymbol trick (along with entry_point_address I
1827 guess) to determine the address range of the start function.
1828 That should provide a far better stopper than the current
1830 /* NOTE: cagney/2003-07-15: Need to add a "set backtrace
1831 beyond-entry-func" command so that this can be selectively
1835 && backtrace_beyond_entry_func
1837 && this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1838 && inside_entry_func (this_frame
))
1842 fprintf_unfiltered (gdb_stdlog
, "-> ");
1843 fprint_frame (gdb_stdlog
, NULL
);
1844 fprintf_unfiltered (gdb_stdlog
, "// inside entry func }\n");
1849 /* Only try to do the unwind once. */
1850 if (this_frame
->prev_p
)
1854 fprintf_unfiltered (gdb_stdlog
, "-> ");
1855 fprint_frame (gdb_stdlog
, this_frame
->prev
);
1856 fprintf_unfiltered (gdb_stdlog
, " // cached \n");
1858 return this_frame
->prev
;
1860 this_frame
->prev_p
= 1;
1862 /* If we're inside the entry file, it isn't valid. Don't apply this
1863 test to a dummy frame - dummy frame PC's typically land in the
1864 entry file. Don't apply this test to the sentinel frame.
1865 Sentinel frames should always be allowed to unwind. */
1866 /* NOTE: drow/2002-12-25: should there be a way to disable this
1867 check? It assumes a single small entry file, and the way some
1868 debug readers (e.g. dbxread) figure out which object is the
1869 entry file is somewhat hokey. */
1870 /* NOTE: cagney/2003-01-10: If there is a way of disabling this test
1871 then it should probably be moved to before the ->prev_p test,
1873 /* NOTE: vinschen/2003-04-01: Disabled. It turns out that the call
1874 to deprecated_inside_entry_file destroys a meaningful backtrace
1875 under some conditions. E. g. the backtrace tests in the
1876 asm-source testcase are broken for some targets. In this test
1877 the functions are all implemented as part of one file and the
1878 testcase is not necessarily linked with a start file (depending
1879 on the target). What happens is, that the first frame is printed
1880 normaly and following frames are treated as being inside the
1881 enttry file then. This way, only the #0 frame is printed in the
1882 backtrace output. */
1884 && this_frame
->type
!= DUMMY_FRAME
&& this_frame
->level
>= 0
1885 && deprecated_inside_entry_file (get_frame_pc (this_frame
)))
1889 fprintf_unfiltered (gdb_stdlog
, "-> ");
1890 fprint_frame (gdb_stdlog
, NULL
);
1891 fprintf_unfiltered (gdb_stdlog
, " // inside entry file }\n");
1896 /* If any of the old frame initialization methods are around, use
1897 the legacy get_prev_frame method. */
1898 if (legacy_frame_p (current_gdbarch
))
1900 prev_frame
= legacy_get_prev_frame (this_frame
);
1904 /* Check that this frame's ID was valid. If it wasn't, don't try to
1905 unwind to the prev frame. Be careful to not apply this test to
1906 the sentinel frame. */
1907 if (this_frame
->level
>= 0 && !frame_id_p (get_frame_id (this_frame
)))
1911 fprintf_unfiltered (gdb_stdlog
, "-> ");
1912 fprint_frame (gdb_stdlog
, NULL
);
1913 fprintf_unfiltered (gdb_stdlog
, " // this ID is NULL }\n");
1918 /* Check that this frame's ID isn't inner to (younger, below, next)
1919 the next frame. This happens when a frame unwind goes backwards.
1920 Since the sentinel frame doesn't really exist, don't compare the
1921 inner-most against that sentinel. */
1922 if (this_frame
->level
> 0
1923 && frame_id_inner (get_frame_id (this_frame
),
1924 get_frame_id (this_frame
->next
)))
1925 error ("Previous frame inner to this frame (corrupt stack?)");
1927 /* Check that this and the next frame are not identical. If they
1928 are, there is most likely a stack cycle. As with the inner-than
1929 test above, avoid comparing the inner-most and sentinel frames. */
1930 if (this_frame
->level
> 0
1931 && frame_id_eq (get_frame_id (this_frame
),
1932 get_frame_id (this_frame
->next
)))
1933 error ("Previous frame identical to this frame (corrupt stack?)");
1935 /* Allocate the new frame but do not wire it in to the frame chain.
1936 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1937 frame->next to pull some fancy tricks (of course such code is, by
1938 definition, recursive). Try to prevent it.
1940 There is no reason to worry about memory leaks, should the
1941 remainder of the function fail. The allocated memory will be
1942 quickly reclaimed when the frame cache is flushed, and the `we've
1943 been here before' check above will stop repeated memory
1944 allocation calls. */
1945 prev_frame
= FRAME_OBSTACK_ZALLOC (struct frame_info
);
1946 prev_frame
->level
= this_frame
->level
+ 1;
1948 /* Don't yet compute ->unwind (and hence ->type). It is computed
1949 on-demand in get_frame_type, frame_register_unwind, and
1952 /* Don't yet compute the frame's ID. It is computed on-demand by
1955 /* The unwound frame ID is validate at the start of this function,
1956 as part of the logic to decide if that frame should be further
1957 unwound, and not here while the prev frame is being created.
1958 Doing this makes it possible for the user to examine a frame that
1959 has an invalid frame ID.
1961 Some very old VAX code noted: [...] For the sake of argument,
1962 suppose that the stack is somewhat trashed (which is one reason
1963 that "info frame" exists). So, return 0 (indicating we don't
1964 know the address of the arglist) if we don't know what frame this
1968 this_frame
->prev
= prev_frame
;
1969 prev_frame
->next
= this_frame
;
1973 fprintf_unfiltered (gdb_stdlog
, "-> ");
1974 fprint_frame (gdb_stdlog
, prev_frame
);
1975 fprintf_unfiltered (gdb_stdlog
, " }\n");
1982 get_frame_pc (struct frame_info
*frame
)
1984 gdb_assert (frame
->next
!= NULL
);
1985 return frame_pc_unwind (frame
->next
);
1988 /* Return an address of that falls within the frame's code block. */
1991 frame_unwind_address_in_block (struct frame_info
*next_frame
)
1993 /* A draft address. */
1994 CORE_ADDR pc
= frame_pc_unwind (next_frame
);
1996 /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
1997 and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
1998 frame's PC ends up pointing at the instruction fallowing the
1999 "call". Adjust that PC value so that it falls on the call
2000 instruction (which, hopefully, falls within THIS frame's code
2001 block. So far it's proved to be a very good approximation. See
2002 get_frame_type for why ->type can't be used. */
2003 if (next_frame
->level
>= 0
2004 && get_frame_type (next_frame
) == NORMAL_FRAME
)
2010 get_frame_address_in_block (struct frame_info
*this_frame
)
2012 return frame_unwind_address_in_block (this_frame
->next
);
2016 pc_notcurrent (struct frame_info
*frame
)
2018 /* If FRAME is not the innermost frame, that normally means that
2019 FRAME->pc points at the return instruction (which is *after* the
2020 call instruction), and we want to get the line containing the
2021 call (because the call is where the user thinks the program is).
2022 However, if the next frame is either a SIGTRAMP_FRAME or a
2023 DUMMY_FRAME, then the next frame will contain a saved interrupt
2024 PC and such a PC indicates the current (rather than next)
2025 instruction/line, consequently, for such cases, want to get the
2026 line containing fi->pc. */
2027 struct frame_info
*next
= get_next_frame (frame
);
2028 int notcurrent
= (next
!= NULL
&& get_frame_type (next
) == NORMAL_FRAME
);
2033 find_frame_sal (struct frame_info
*frame
, struct symtab_and_line
*sal
)
2035 (*sal
) = find_pc_line (get_frame_pc (frame
), pc_notcurrent (frame
));
2038 /* Per "frame.h", return the ``address'' of the frame. Code should
2039 really be using get_frame_id(). */
2041 get_frame_base (struct frame_info
*fi
)
2043 return get_frame_id (fi
).stack_addr
;
2046 /* High-level offsets into the frame. Used by the debug info. */
2049 get_frame_base_address (struct frame_info
*fi
)
2051 if (get_frame_type (fi
) != NORMAL_FRAME
)
2053 if (fi
->base
== NULL
)
2054 fi
->base
= frame_base_find_by_frame (fi
->next
);
2055 /* Sneaky: If the low-level unwind and high-level base code share a
2056 common unwinder, let them share the prologue cache. */
2057 if (fi
->base
->unwind
== fi
->unwind
)
2058 return fi
->base
->this_base (fi
->next
, &fi
->prologue_cache
);
2059 return fi
->base
->this_base (fi
->next
, &fi
->base_cache
);
2063 get_frame_locals_address (struct frame_info
*fi
)
2066 if (get_frame_type (fi
) != NORMAL_FRAME
)
2068 /* If there isn't a frame address method, find it. */
2069 if (fi
->base
== NULL
)
2070 fi
->base
= frame_base_find_by_frame (fi
->next
);
2071 /* Sneaky: If the low-level unwind and high-level base code share a
2072 common unwinder, let them share the prologue cache. */
2073 if (fi
->base
->unwind
== fi
->unwind
)
2074 cache
= &fi
->prologue_cache
;
2076 cache
= &fi
->base_cache
;
2077 return fi
->base
->this_locals (fi
->next
, cache
);
2081 get_frame_args_address (struct frame_info
*fi
)
2084 if (get_frame_type (fi
) != NORMAL_FRAME
)
2086 /* If there isn't a frame address method, find it. */
2087 if (fi
->base
== NULL
)
2088 fi
->base
= frame_base_find_by_frame (fi
->next
);
2089 /* Sneaky: If the low-level unwind and high-level base code share a
2090 common unwinder, let them share the prologue cache. */
2091 if (fi
->base
->unwind
== fi
->unwind
)
2092 cache
= &fi
->prologue_cache
;
2094 cache
= &fi
->base_cache
;
2095 return fi
->base
->this_args (fi
->next
, cache
);
2098 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
2099 or -1 for a NULL frame. */
2102 frame_relative_level (struct frame_info
*fi
)
2111 get_frame_type (struct frame_info
*frame
)
2113 /* Some targets still don't use [generic] dummy frames. Catch them
2115 if (!DEPRECATED_USE_GENERIC_DUMMY_FRAMES
2116 && deprecated_frame_in_dummy (frame
))
2119 /* Some legacy code, e.g, mips_init_extra_frame_info() wants
2120 to determine the frame's type prior to it being completely
2121 initialized. Don't attempt to lazily initialize ->unwind for
2122 legacy code. It will be initialized in legacy_get_prev_frame(). */
2123 if (frame
->unwind
== NULL
&& !legacy_frame_p (current_gdbarch
))
2125 /* Initialize the frame's unwinder because it is that which
2126 provides the frame's type. */
2127 frame
->unwind
= frame_unwind_find_by_frame (frame
->next
);
2128 /* FIXME: cagney/2003-04-02: Rather than storing the frame's
2129 type in the frame, the unwinder's type should be returned
2130 directly. Unfortunately, legacy code, called by
2131 legacy_get_prev_frame, explicitly set the frames type using
2132 the method deprecated_set_frame_type(). */
2133 frame
->type
= frame
->unwind
->type
;
2135 if (frame
->type
== UNKNOWN_FRAME
)
2136 return NORMAL_FRAME
;
2142 deprecated_set_frame_type (struct frame_info
*frame
, enum frame_type type
)
2144 /* Arrrg! See comment in "frame.h". */
2148 struct frame_extra_info
*
2149 get_frame_extra_info (struct frame_info
*fi
)
2151 return fi
->extra_info
;
2154 struct frame_extra_info
*
2155 frame_extra_info_zalloc (struct frame_info
*fi
, long size
)
2157 fi
->extra_info
= frame_obstack_zalloc (size
);
2158 return fi
->extra_info
;
2162 deprecated_update_frame_pc_hack (struct frame_info
*frame
, CORE_ADDR pc
)
2165 fprintf_unfiltered (gdb_stdlog
,
2166 "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
2167 frame
->level
, paddr_nz (pc
));
2168 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
2169 maintaining a locally allocated frame object. Since such frame's
2170 are not in the frame chain, it isn't possible to assume that the
2171 frame has a next. Sigh. */
2172 if (frame
->next
!= NULL
)
2174 /* While we're at it, update this frame's cached PC value, found
2175 in the next frame. Oh for the day when "struct frame_info"
2176 is opaque and this hack on hack can just go away. */
2177 frame
->next
->prev_pc
.value
= pc
;
2178 frame
->next
->prev_pc
.p
= 1;
2183 deprecated_update_frame_base_hack (struct frame_info
*frame
, CORE_ADDR base
)
2186 fprintf_unfiltered (gdb_stdlog
,
2187 "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
2188 frame
->level
, paddr_nz (base
));
2189 /* See comment in "frame.h". */
2190 frame
->this_id
.value
.stack_addr
= base
;
2194 deprecated_frame_xmalloc_with_cleanup (long sizeof_saved_regs
,
2195 long sizeof_extra_info
)
2197 struct frame_info
*frame
= XMALLOC (struct frame_info
);
2198 memset (frame
, 0, sizeof (*frame
));
2199 frame
->this_id
.p
= 1;
2200 make_cleanup (xfree
, frame
);
2201 if (sizeof_saved_regs
> 0)
2203 frame
->saved_regs
= xcalloc (1, sizeof_saved_regs
);
2204 make_cleanup (xfree
, frame
->saved_regs
);
2206 if (sizeof_extra_info
> 0)
2208 frame
->extra_info
= xcalloc (1, sizeof_extra_info
);
2209 make_cleanup (xfree
, frame
->extra_info
);
2214 /* Memory access methods. */
2217 get_frame_memory (struct frame_info
*this_frame
, CORE_ADDR addr
, void *buf
,
2220 read_memory (addr
, buf
, len
);
2224 get_frame_memory_signed (struct frame_info
*this_frame
, CORE_ADDR addr
,
2227 return read_memory_integer (addr
, len
);
2231 get_frame_memory_unsigned (struct frame_info
*this_frame
, CORE_ADDR addr
,
2234 return read_memory_unsigned_integer (addr
, len
);
2237 /* Architecture method. */
2240 get_frame_arch (struct frame_info
*this_frame
)
2242 return current_gdbarch
;
2245 /* Stack pointer methods. */
2248 get_frame_sp (struct frame_info
*this_frame
)
2250 return frame_sp_unwind (this_frame
->next
);
2254 frame_sp_unwind (struct frame_info
*next_frame
)
2256 /* Normality, an architecture that provides a way of obtaining any
2257 frame inner-most address. */
2258 if (gdbarch_unwind_sp_p (current_gdbarch
))
2259 return gdbarch_unwind_sp (current_gdbarch
, next_frame
);
2260 /* Things are looking grim. If it's the inner-most frame and there
2261 is a TARGET_READ_SP then that can be used. */
2262 if (next_frame
->level
< 0 && TARGET_READ_SP_P ())
2263 return TARGET_READ_SP ();
2264 /* Now things are really are grim. Hope that the value returned by
2265 the SP_REGNUM register is meaningful. */
2269 frame_unwind_unsigned_register (next_frame
, SP_REGNUM
, &sp
);
2272 internal_error (__FILE__
, __LINE__
, "Missing unwind SP method");
2277 legacy_frame_p (struct gdbarch
*current_gdbarch
)
2279 if (DEPRECATED_INIT_FRAME_PC_P ()
2280 || DEPRECATED_INIT_FRAME_PC_FIRST_P ()
2281 || DEPRECATED_INIT_EXTRA_FRAME_INFO_P ()
2282 || DEPRECATED_FRAME_CHAIN_P ())
2283 /* No question, it's a legacy frame. */
2285 if (gdbarch_unwind_dummy_id_p (current_gdbarch
))
2286 /* No question, it's not a legacy frame (provided none of the
2287 deprecated methods checked above are present that is). */
2289 if (DEPRECATED_TARGET_READ_FP_P ()
2290 || DEPRECATED_FP_REGNUM
>= 0)
2291 /* Assume it's legacy. If you're trying to convert a legacy frame
2292 target to the new mechanism, get rid of these. legacy
2293 get_prev_frame requires these when unwind_frame_id isn't
2296 /* Default to assuming that it's brand new code, and hence not
2297 legacy. Force it down the non-legacy path so that the new code
2298 uses the new frame mechanism from day one. Dummy frame's won't
2299 work very well but we can live with that. */
2303 extern initialize_file_ftype _initialize_frame
; /* -Wmissing-prototypes */
2305 static struct cmd_list_element
*set_backtrace_cmdlist
;
2306 static struct cmd_list_element
*show_backtrace_cmdlist
;
2309 set_backtrace_cmd (char *args
, int from_tty
)
2311 help_list (set_backtrace_cmdlist
, "set backtrace ", -1, gdb_stdout
);
2315 show_backtrace_cmd (char *args
, int from_tty
)
2317 cmd_show_list (show_backtrace_cmdlist
, from_tty
, "");
2321 _initialize_frame (void)
2323 obstack_init (&frame_cache_obstack
);
2325 add_prefix_cmd ("backtrace", class_maintenance
, set_backtrace_cmd
, "\
2326 Set backtrace specific variables.\n\
2327 Configure backtrace variables such as the backtrace limit",
2328 &set_backtrace_cmdlist
, "set backtrace ",
2329 0/*allow-unknown*/, &setlist
);
2330 add_prefix_cmd ("backtrace", class_maintenance
, show_backtrace_cmd
, "\
2331 Show backtrace specific variables\n\
2332 Show backtrace variables such as the backtrace limit",
2333 &show_backtrace_cmdlist
, "show backtrace ",
2334 0/*allow-unknown*/, &showlist
);
2336 add_setshow_boolean_cmd ("past-main", class_obscure
,
2337 &backtrace_past_main
, "\
2338 Set whether backtraces should continue past \"main\".\n\
2339 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
2340 the backtrace at \"main\". Set this variable if you need to see the rest\n\
2341 of the stack trace.", "\
2342 Show whether backtraces should continue past \"main\".\n\
2343 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
2344 the backtrace at \"main\". Set this variable if you need to see the rest\n\
2345 of the stack trace.",
2346 NULL
, NULL
, &set_backtrace_cmdlist
,
2347 &show_backtrace_cmdlist
);
2349 add_setshow_uinteger_cmd ("limit", class_obscure
,
2350 &backtrace_limit
, "\
2351 Set an upper bound on the number of backtrace levels.\n\
2352 No more than the specified number of frames can be displayed or examined.\n\
2353 Zero is unlimited.", "\
2354 Show the upper bound on the number of backtrace levels.",
2355 NULL
, NULL
, &set_backtrace_cmdlist
,
2356 &show_backtrace_cmdlist
);
2358 /* Debug this files internals. */
2359 add_show_from_set (add_set_cmd ("frame", class_maintenance
, var_zinteger
,
2360 &frame_debug
, "Set frame debugging.\n\
2361 When non-zero, frame specific internal debugging is enabled.", &setdebuglist
),