1 /* Cache and manage frames for GDB, the GNU debugger.
3 Copyright (C) 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., 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, 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"
44 #include "exceptions.h"
46 static struct frame_info *get_prev_frame_1 (struct frame_info *this_frame);
48 /* We keep a cache of stack frames, each of which is a "struct
49 frame_info". The innermost one gets allocated (in
50 wait_for_inferior) each time the inferior stops; current_frame
51 points to it. Additional frames get allocated (in get_prev_frame)
52 as needed, and are chained through the next and prev fields. Any
53 time that the frame cache becomes invalid (most notably when we
54 execute something, but also if we change how we interpret the
55 frames (e.g. "set heuristic-fence-post" in mips-tdep.c, or anything
56 which reads new symbols)), we should call reinit_frame_cache. */
60 /* Level of this frame. The inner-most (youngest) frame is at level
61 0. As you move towards the outer-most (oldest) frame, the level
62 increases. This is a cached value. It could just as easily be
63 computed by counting back from the selected frame to the inner
65 /* NOTE: cagney/2002-04-05: Perhaps a level of ``-1'' should be
66 reserved to indicate a bogus frame - one that has been created
67 just to keep GDB happy (GDB always needs a frame). For the
68 moment leave this as speculation. */
71 /* The frame's low-level unwinder and corresponding cache. The
72 low-level unwinder is responsible for unwinding register values
73 for the previous frame. The low-level unwind methods are
74 selected based on the presence, or otherwise, of register unwind
75 information such as CFI. */
77 const struct frame_unwind *unwind;
79 /* Cached copy of the previous frame's resume address. */
85 /* Cached copy of the previous frame's function address. */
92 /* This frame's ID. */
96 struct frame_id value;
99 /* The frame's high-level base methods, and corresponding cache.
100 The high level base methods are selected based on the frame's
102 const struct frame_base *base;
105 /* Pointers to the next (down, inner, younger) and previous (up,
106 outer, older) frame_info's in the frame cache. */
107 struct frame_info *next; /* down, inner, younger */
109 struct frame_info *prev; /* up, outer, older */
111 /* The reason why we could not set PREV, or UNWIND_NO_REASON if we
112 could. Only valid when PREV_P is set. */
113 enum unwind_stop_reason stop_reason;
116 /* Flag to control debugging. */
118 static int frame_debug;
120 show_frame_debug (struct ui_file *file, int from_tty,
121 struct cmd_list_element *c, const char *value)
123 fprintf_filtered (file, _("Frame debugging is %s.\n"), value);
126 /* Flag to indicate whether backtraces should stop at main et.al. */
128 static int backtrace_past_main;
130 show_backtrace_past_main (struct ui_file *file, int from_tty,
131 struct cmd_list_element *c, const char *value)
133 fprintf_filtered (file, _("\
134 Whether backtraces should continue past \"main\" is %s.\n"),
138 static int backtrace_past_entry;
140 show_backtrace_past_entry (struct ui_file *file, int from_tty,
141 struct cmd_list_element *c, const char *value)
143 fprintf_filtered (file, _("\
144 Whether backtraces should continue past the entry point of a program is %s.\n"),
148 static int backtrace_limit = INT_MAX;
150 show_backtrace_limit (struct ui_file *file, int from_tty,
151 struct cmd_list_element *c, const char *value)
153 fprintf_filtered (file, _("\
154 An upper bound on the number of backtrace levels is %s.\n"),
160 fprint_field (struct ui_file *file, const char *name, int p, CORE_ADDR addr)
163 fprintf_unfiltered (file, "%s=0x%s", name, paddr_nz (addr));
165 fprintf_unfiltered (file, "!%s", name);
169 fprint_frame_id (struct ui_file *file, struct frame_id id)
171 fprintf_unfiltered (file, "{");
172 fprint_field (file, "stack", id.stack_addr_p, id.stack_addr);
173 fprintf_unfiltered (file, ",");
174 fprint_field (file, "code", id.code_addr_p, id.code_addr);
175 fprintf_unfiltered (file, ",");
176 fprint_field (file, "special", id.special_addr_p, id.special_addr);
177 fprintf_unfiltered (file, "}");
181 fprint_frame_type (struct ui_file *file, enum frame_type type)
186 fprintf_unfiltered (file, "NORMAL_FRAME");
189 fprintf_unfiltered (file, "DUMMY_FRAME");
192 fprintf_unfiltered (file, "SIGTRAMP_FRAME");
195 fprintf_unfiltered (file, "<unknown type>");
201 fprint_frame (struct ui_file *file, struct frame_info *fi)
205 fprintf_unfiltered (file, "<NULL frame>");
208 fprintf_unfiltered (file, "{");
209 fprintf_unfiltered (file, "level=%d", fi->level);
210 fprintf_unfiltered (file, ",");
211 fprintf_unfiltered (file, "type=");
212 if (fi->unwind != NULL)
213 fprint_frame_type (file, fi->unwind->type);
215 fprintf_unfiltered (file, "<unknown>");
216 fprintf_unfiltered (file, ",");
217 fprintf_unfiltered (file, "unwind=");
218 if (fi->unwind != NULL)
219 gdb_print_host_address (fi->unwind, file);
221 fprintf_unfiltered (file, "<unknown>");
222 fprintf_unfiltered (file, ",");
223 fprintf_unfiltered (file, "pc=");
224 if (fi->next != NULL && fi->next->prev_pc.p)
225 fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_pc.value));
227 fprintf_unfiltered (file, "<unknown>");
228 fprintf_unfiltered (file, ",");
229 fprintf_unfiltered (file, "id=");
231 fprint_frame_id (file, fi->this_id.value);
233 fprintf_unfiltered (file, "<unknown>");
234 fprintf_unfiltered (file, ",");
235 fprintf_unfiltered (file, "func=");
236 if (fi->next != NULL && fi->next->prev_func.p)
237 fprintf_unfiltered (file, "0x%s", paddr_nz (fi->next->prev_func.addr));
239 fprintf_unfiltered (file, "<unknown>");
240 fprintf_unfiltered (file, "}");
243 /* Return a frame uniq ID that can be used to, later, re-find the
247 get_frame_id (struct frame_info *fi)
251 return null_frame_id;
256 fprintf_unfiltered (gdb_stdlog, "{ get_frame_id (fi=%d) ",
258 /* Find the unwinder. */
259 if (fi->unwind == NULL)
260 fi->unwind = frame_unwind_find_by_frame (fi->next,
261 &fi->prologue_cache);
262 /* Find THIS frame's ID. */
263 fi->unwind->this_id (fi->next, &fi->prologue_cache, &fi->this_id.value);
267 fprintf_unfiltered (gdb_stdlog, "-> ");
268 fprint_frame_id (gdb_stdlog, fi->this_id.value);
269 fprintf_unfiltered (gdb_stdlog, " }\n");
272 return fi->this_id.value;
276 frame_unwind_id (struct frame_info *next_frame)
278 /* Use prev_frame, and not get_prev_frame. The latter will truncate
279 the frame chain, leading to this function unintentionally
280 returning a null_frame_id (e.g., when a caller requests the frame
281 ID of "main()"s caller. */
282 return get_frame_id (get_prev_frame_1 (next_frame));
285 const struct frame_id null_frame_id; /* All zeros. */
288 frame_id_build_special (CORE_ADDR stack_addr, CORE_ADDR code_addr,
289 CORE_ADDR special_addr)
291 struct frame_id id = null_frame_id;
292 id.stack_addr = stack_addr;
294 id.code_addr = code_addr;
296 id.special_addr = special_addr;
297 id.special_addr_p = 1;
302 frame_id_build (CORE_ADDR stack_addr, CORE_ADDR code_addr)
304 struct frame_id id = null_frame_id;
305 id.stack_addr = stack_addr;
307 id.code_addr = code_addr;
313 frame_id_build_wild (CORE_ADDR stack_addr)
315 struct frame_id id = null_frame_id;
316 id.stack_addr = stack_addr;
322 frame_id_p (struct frame_id l)
325 /* The frame is valid iff it has a valid stack address. */
329 fprintf_unfiltered (gdb_stdlog, "{ frame_id_p (l=");
330 fprint_frame_id (gdb_stdlog, l);
331 fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", p);
337 frame_id_eq (struct frame_id l, struct frame_id r)
340 if (!l.stack_addr_p || !r.stack_addr_p)
341 /* Like a NaN, if either ID is invalid, the result is false.
342 Note that a frame ID is invalid iff it is the null frame ID. */
344 else if (l.stack_addr != r.stack_addr)
345 /* If .stack addresses are different, the frames are different. */
347 else if (!l.code_addr_p || !r.code_addr_p)
348 /* An invalid code addr is a wild card, always succeed. */
350 else if (l.code_addr != r.code_addr)
351 /* If .code addresses are different, the frames are different. */
353 else if (!l.special_addr_p || !r.special_addr_p)
354 /* An invalid special addr is a wild card (or unused), always succeed. */
356 else if (l.special_addr == r.special_addr)
357 /* Frames are equal. */
364 fprintf_unfiltered (gdb_stdlog, "{ frame_id_eq (l=");
365 fprint_frame_id (gdb_stdlog, l);
366 fprintf_unfiltered (gdb_stdlog, ",r=");
367 fprint_frame_id (gdb_stdlog, r);
368 fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", eq);
374 frame_id_inner (struct frame_id l, struct frame_id r)
377 if (!l.stack_addr_p || !r.stack_addr_p)
378 /* Like NaN, any operation involving an invalid ID always fails. */
381 /* Only return non-zero when strictly inner than. Note that, per
382 comment in "frame.h", there is some fuzz here. Frameless
383 functions are not strictly inner than (same .stack but
384 different .code and/or .special address). */
385 inner = INNER_THAN (l.stack_addr, r.stack_addr);
388 fprintf_unfiltered (gdb_stdlog, "{ frame_id_inner (l=");
389 fprint_frame_id (gdb_stdlog, l);
390 fprintf_unfiltered (gdb_stdlog, ",r=");
391 fprint_frame_id (gdb_stdlog, r);
392 fprintf_unfiltered (gdb_stdlog, ") -> %d }\n", inner);
398 frame_find_by_id (struct frame_id id)
400 struct frame_info *frame;
402 /* ZERO denotes the null frame, let the caller decide what to do
403 about it. Should it instead return get_current_frame()? */
404 if (!frame_id_p (id))
407 for (frame = get_current_frame ();
409 frame = get_prev_frame (frame))
411 struct frame_id this = get_frame_id (frame);
412 if (frame_id_eq (id, this))
413 /* An exact match. */
415 if (frame_id_inner (id, this))
418 /* Either we're not yet gone far enough out along the frame
419 chain (inner(this,id)), or we're comparing frameless functions
420 (same .base, different .func, no test available). Struggle
421 on until we've definitly gone to far. */
427 frame_pc_unwind (struct frame_info *this_frame)
429 if (!this_frame->prev_pc.p)
432 if (this_frame->unwind == NULL)
434 = frame_unwind_find_by_frame (this_frame->next,
435 &this_frame->prologue_cache);
436 if (this_frame->unwind->prev_pc != NULL)
437 /* A per-frame unwinder, prefer it. */
438 pc = this_frame->unwind->prev_pc (this_frame->next,
439 &this_frame->prologue_cache);
440 else if (gdbarch_unwind_pc_p (current_gdbarch))
442 /* The right way. The `pure' way. The one true way. This
443 method depends solely on the register-unwind code to
444 determine the value of registers in THIS frame, and hence
445 the value of this frame's PC (resume address). A typical
446 implementation is no more than:
448 frame_unwind_register (this_frame, ISA_PC_REGNUM, buf);
449 return extract_unsigned_integer (buf, size of ISA_PC_REGNUM);
451 Note: this method is very heavily dependent on a correct
452 register-unwind implementation, it pays to fix that
453 method first; this method is frame type agnostic, since
454 it only deals with register values, it works with any
455 frame. This is all in stark contrast to the old
456 FRAME_SAVED_PC which would try to directly handle all the
457 different ways that a PC could be unwound. */
458 pc = gdbarch_unwind_pc (current_gdbarch, this_frame);
461 internal_error (__FILE__, __LINE__, _("No unwind_pc method"));
462 this_frame->prev_pc.value = pc;
463 this_frame->prev_pc.p = 1;
465 fprintf_unfiltered (gdb_stdlog,
466 "{ frame_pc_unwind (this_frame=%d) -> 0x%s }\n",
468 paddr_nz (this_frame->prev_pc.value));
470 return this_frame->prev_pc.value;
474 frame_func_unwind (struct frame_info *fi)
476 if (!fi->prev_func.p)
478 /* Make certain that this, and not the adjacent, function is
480 CORE_ADDR addr_in_block = frame_unwind_address_in_block (fi);
482 fi->prev_func.addr = get_pc_function_start (addr_in_block);
484 fprintf_unfiltered (gdb_stdlog,
485 "{ frame_func_unwind (fi=%d) -> 0x%s }\n",
486 fi->level, paddr_nz (fi->prev_func.addr));
488 return fi->prev_func.addr;
492 get_frame_func (struct frame_info *fi)
494 return frame_func_unwind (fi->next);
498 do_frame_register_read (void *src, int regnum, gdb_byte *buf)
500 frame_register_read (src, regnum, buf);
505 frame_save_as_regcache (struct frame_info *this_frame)
507 struct regcache *regcache = regcache_xmalloc (current_gdbarch);
508 struct cleanup *cleanups = make_cleanup_regcache_xfree (regcache);
509 regcache_save (regcache, do_frame_register_read, this_frame);
510 discard_cleanups (cleanups);
515 frame_pop (struct frame_info *this_frame)
517 /* Make a copy of all the register values unwound from this frame.
518 Save them in a scratch buffer so that there isn't a race between
519 trying to extract the old values from the current_regcache while
520 at the same time writing new values into that same cache. */
521 struct regcache *scratch
522 = frame_save_as_regcache (get_prev_frame_1 (this_frame));
523 struct cleanup *cleanups = make_cleanup_regcache_xfree (scratch);
525 /* FIXME: cagney/2003-03-16: It should be possible to tell the
526 target's register cache that it is about to be hit with a burst
527 register transfer and that the sequence of register writes should
528 be batched. The pair target_prepare_to_store() and
529 target_store_registers() kind of suggest this functionality.
530 Unfortunately, they don't implement it. Their lack of a formal
531 definition can lead to targets writing back bogus values
532 (arguably a bug in the target code mind). */
533 /* Now copy those saved registers into the current regcache.
534 Here, regcache_cpy() calls regcache_restore(). */
535 regcache_cpy (current_regcache, scratch);
536 do_cleanups (cleanups);
538 /* We've made right mess of GDB's local state, just discard
540 flush_cached_frames ();
544 frame_register_unwind (struct frame_info *frame, int regnum,
545 int *optimizedp, enum lval_type *lvalp,
546 CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp)
548 struct frame_unwind_cache *cache;
552 fprintf_unfiltered (gdb_stdlog, "\
553 { frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
554 frame->level, regnum,
555 frame_map_regnum_to_name (frame, regnum));
558 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
559 that the value proper does not need to be fetched. */
560 gdb_assert (optimizedp != NULL);
561 gdb_assert (lvalp != NULL);
562 gdb_assert (addrp != NULL);
563 gdb_assert (realnump != NULL);
564 /* gdb_assert (bufferp != NULL); */
566 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
567 is broken. There is always a frame. If there, for some reason,
568 isn't a frame, there is some pretty busted code as it should have
569 detected the problem before calling here. */
570 gdb_assert (frame != NULL);
572 /* Find the unwinder. */
573 if (frame->unwind == NULL)
574 frame->unwind = frame_unwind_find_by_frame (frame->next,
575 &frame->prologue_cache);
577 /* Ask this frame to unwind its register. See comment in
578 "frame-unwind.h" for why NEXT frame and this unwind cache are
580 frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum,
581 optimizedp, lvalp, addrp, realnump, bufferp);
585 fprintf_unfiltered (gdb_stdlog, "->");
586 fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp));
587 fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp));
588 fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp)));
589 fprintf_unfiltered (gdb_stdlog, " *bufferp=");
591 fprintf_unfiltered (gdb_stdlog, "<NULL>");
595 const unsigned char *buf = bufferp;
596 fprintf_unfiltered (gdb_stdlog, "[");
597 for (i = 0; i < register_size (current_gdbarch, regnum); i++)
598 fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
599 fprintf_unfiltered (gdb_stdlog, "]");
601 fprintf_unfiltered (gdb_stdlog, " }\n");
606 frame_register (struct frame_info *frame, int regnum,
607 int *optimizedp, enum lval_type *lvalp,
608 CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp)
610 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
611 that the value proper does not need to be fetched. */
612 gdb_assert (optimizedp != NULL);
613 gdb_assert (lvalp != NULL);
614 gdb_assert (addrp != NULL);
615 gdb_assert (realnump != NULL);
616 /* gdb_assert (bufferp != NULL); */
618 /* Obtain the register value by unwinding the register from the next
619 (more inner frame). */
620 gdb_assert (frame != NULL && frame->next != NULL);
621 frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
626 frame_unwind_register (struct frame_info *frame, int regnum, gdb_byte *buf)
632 frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
637 get_frame_register (struct frame_info *frame,
638 int regnum, gdb_byte *buf)
640 frame_unwind_register (frame->next, regnum, buf);
644 frame_unwind_register_signed (struct frame_info *frame, int regnum)
646 gdb_byte buf[MAX_REGISTER_SIZE];
647 frame_unwind_register (frame, regnum, buf);
648 return extract_signed_integer (buf, register_size (get_frame_arch (frame),
653 get_frame_register_signed (struct frame_info *frame, int regnum)
655 return frame_unwind_register_signed (frame->next, regnum);
659 frame_unwind_register_unsigned (struct frame_info *frame, int regnum)
661 gdb_byte buf[MAX_REGISTER_SIZE];
662 frame_unwind_register (frame, regnum, buf);
663 return extract_unsigned_integer (buf, register_size (get_frame_arch (frame),
668 get_frame_register_unsigned (struct frame_info *frame, int regnum)
670 return frame_unwind_register_unsigned (frame->next, regnum);
674 frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
677 gdb_byte buf[MAX_REGISTER_SIZE];
678 frame_unwind_register (frame, regnum, buf);
679 (*val) = extract_unsigned_integer (buf,
680 register_size (get_frame_arch (frame),
685 put_frame_register (struct frame_info *frame, int regnum,
688 struct gdbarch *gdbarch = get_frame_arch (frame);
693 frame_register (frame, regnum, &optim, &lval, &addr, &realnum, NULL);
695 error (_("Attempt to assign to a value that was optimized out."));
700 /* FIXME: write_memory doesn't yet take constant buffers.
702 gdb_byte tmp[MAX_REGISTER_SIZE];
703 memcpy (tmp, buf, register_size (gdbarch, regnum));
704 write_memory (addr, tmp, register_size (gdbarch, regnum));
708 regcache_cooked_write (current_regcache, realnum, buf);
711 error (_("Attempt to assign to an unmodifiable value."));
715 /* frame_register_read ()
717 Find and return the value of REGNUM for the specified stack frame.
718 The number of bytes copied is REGISTER_SIZE (REGNUM).
720 Returns 0 if the register value could not be found. */
723 frame_register_read (struct frame_info *frame, int regnum,
730 frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
732 /* FIXME: cagney/2002-05-15: This test is just bogus.
734 It indicates that the target failed to supply a value for a
735 register because it was "not available" at this time. Problem
736 is, the target still has the register and so get saved_register()
737 may be returning a value saved on the stack. */
739 if (register_cached (regnum) < 0)
740 return 0; /* register value not available */
746 get_frame_register_bytes (struct frame_info *frame, int regnum,
747 CORE_ADDR offset, int len, gdb_byte *myaddr)
749 struct gdbarch *gdbarch = get_frame_arch (frame);
751 /* Skip registers wholly inside of OFFSET. */
752 while (offset >= register_size (gdbarch, regnum))
754 offset -= register_size (gdbarch, regnum);
761 int curr_len = register_size (gdbarch, regnum) - offset;
765 if (curr_len == register_size (gdbarch, regnum))
767 if (!frame_register_read (frame, regnum, myaddr))
772 gdb_byte buf[MAX_REGISTER_SIZE];
773 if (!frame_register_read (frame, regnum, buf))
775 memcpy (myaddr, buf + offset, curr_len);
787 put_frame_register_bytes (struct frame_info *frame, int regnum,
788 CORE_ADDR offset, int len, const gdb_byte *myaddr)
790 struct gdbarch *gdbarch = get_frame_arch (frame);
792 /* Skip registers wholly inside of OFFSET. */
793 while (offset >= register_size (gdbarch, regnum))
795 offset -= register_size (gdbarch, regnum);
802 int curr_len = register_size (gdbarch, regnum) - offset;
806 if (curr_len == register_size (gdbarch, regnum))
808 put_frame_register (frame, regnum, myaddr);
812 gdb_byte buf[MAX_REGISTER_SIZE];
813 frame_register_read (frame, regnum, buf);
814 memcpy (buf + offset, myaddr, curr_len);
815 put_frame_register (frame, regnum, buf);
824 /* Map between a frame register number and its name. A frame register
825 space is a superset of the cooked register space --- it also
826 includes builtin registers. */
829 frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len)
831 return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len);
835 frame_map_regnum_to_name (struct frame_info *frame, int regnum)
837 return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum);
840 /* Create a sentinel frame. */
842 static struct frame_info *
843 create_sentinel_frame (struct regcache *regcache)
845 struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
847 /* Explicitly initialize the sentinel frame's cache. Provide it
848 with the underlying regcache. In the future additional
849 information, such as the frame's thread will be added. */
850 frame->prologue_cache = sentinel_frame_cache (regcache);
851 /* For the moment there is only one sentinel frame implementation. */
852 frame->unwind = sentinel_frame_unwind;
853 /* Link this frame back to itself. The frame is self referential
854 (the unwound PC is the same as the pc), so make it so. */
856 /* Make the sentinel frame's ID valid, but invalid. That way all
857 comparisons with it should fail. */
858 frame->this_id.p = 1;
859 frame->this_id.value = null_frame_id;
862 fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> ");
863 fprint_frame (gdb_stdlog, frame);
864 fprintf_unfiltered (gdb_stdlog, " }\n");
869 /* Info about the innermost stack frame (contents of FP register) */
871 static struct frame_info *current_frame;
873 /* Cache for frame addresses already read by gdb. Valid only while
874 inferior is stopped. Control variables for the frame cache should
875 be local to this module. */
877 static struct obstack frame_cache_obstack;
880 frame_obstack_zalloc (unsigned long size)
882 void *data = obstack_alloc (&frame_cache_obstack, size);
883 memset (data, 0, size);
887 /* Return the innermost (currently executing) stack frame. This is
888 split into two functions. The function unwind_to_current_frame()
889 is wrapped in catch exceptions so that, even when the unwind of the
890 sentinel frame fails, the function still returns a stack frame. */
893 unwind_to_current_frame (struct ui_out *ui_out, void *args)
895 struct frame_info *frame = get_prev_frame (args);
896 /* A sentinel frame can fail to unwind, e.g., because its PC value
897 lands in somewhere like start. */
900 current_frame = frame;
905 get_current_frame (void)
907 /* First check, and report, the lack of registers. Having GDB
908 report "No stack!" or "No memory" when the target doesn't even
909 have registers is very confusing. Besides, "printcmd.exp"
910 explicitly checks that ``print $pc'' with no registers prints "No
912 if (!target_has_registers)
913 error (_("No registers."));
914 if (!target_has_stack)
915 error (_("No stack."));
916 if (!target_has_memory)
917 error (_("No memory."));
918 if (current_frame == NULL)
920 struct frame_info *sentinel_frame =
921 create_sentinel_frame (current_regcache);
922 if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame,
923 RETURN_MASK_ERROR) != 0)
925 /* Oops! Fake a current frame? Is this useful? It has a PC
926 of zero, for instance. */
927 current_frame = sentinel_frame;
930 return current_frame;
933 /* The "selected" stack frame is used by default for local and arg
934 access. May be zero, for no selected frame. */
936 struct frame_info *deprecated_selected_frame;
938 /* Return the selected frame. Always non-NULL (unless there isn't an
939 inferior sufficient for creating a frame) in which case an error is
943 get_selected_frame (const char *message)
945 if (deprecated_selected_frame == NULL)
947 if (message != NULL && (!target_has_registers
949 || !target_has_memory))
950 error (("%s"), message);
951 /* Hey! Don't trust this. It should really be re-finding the
952 last selected frame of the currently selected thread. This,
953 though, is better than nothing. */
954 select_frame (get_current_frame ());
956 /* There is always a frame. */
957 gdb_assert (deprecated_selected_frame != NULL);
958 return deprecated_selected_frame;
961 /* This is a variant of get_selected_frame() which can be called when
962 the inferior does not have a frame; in that case it will return
963 NULL instead of calling error(). */
966 deprecated_safe_get_selected_frame (void)
968 if (!target_has_registers || !target_has_stack || !target_has_memory)
970 return get_selected_frame (NULL);
973 /* Select frame FI (or NULL - to invalidate the current frame). */
976 select_frame (struct frame_info *fi)
980 deprecated_selected_frame = fi;
981 /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
982 frame is being invalidated. */
983 if (deprecated_selected_frame_level_changed_hook)
984 deprecated_selected_frame_level_changed_hook (frame_relative_level (fi));
986 /* FIXME: kseitz/2002-08-28: It would be nice to call
987 selected_frame_level_changed_event() right here, but due to limitations
988 in the current interfaces, we would end up flooding UIs with events
989 because select_frame() is used extensively internally.
991 Once we have frame-parameterized frame (and frame-related) commands,
992 the event notification can be moved here, since this function will only
993 be called when the user's selected frame is being changed. */
995 /* Ensure that symbols for this frame are read in. Also, determine the
996 source language of this frame, and switch to it if desired. */
999 /* We retrieve the frame's symtab by using the frame PC. However
1000 we cannot use the frame PC as-is, because it usually points to
1001 the instruction following the "call", which is sometimes the
1002 first instruction of another function. So we rely on
1003 get_frame_address_in_block() which provides us with a PC which
1004 is guaranteed to be inside the frame's code block. */
1005 s = find_pc_symtab (get_frame_address_in_block (fi));
1007 && s->language != current_language->la_language
1008 && s->language != language_unknown
1009 && language_mode == language_mode_auto)
1011 set_language (s->language);
1016 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
1017 Always returns a non-NULL value. */
1020 create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
1022 struct frame_info *fi;
1026 fprintf_unfiltered (gdb_stdlog,
1027 "{ create_new_frame (addr=0x%s, pc=0x%s) ",
1028 paddr_nz (addr), paddr_nz (pc));
1031 fi = FRAME_OBSTACK_ZALLOC (struct frame_info);
1033 fi->next = create_sentinel_frame (current_regcache);
1035 /* Select/initialize both the unwind function and the frame's type
1037 fi->unwind = frame_unwind_find_by_frame (fi->next, &fi->prologue_cache);
1040 deprecated_update_frame_base_hack (fi, addr);
1041 deprecated_update_frame_pc_hack (fi, pc);
1045 fprintf_unfiltered (gdb_stdlog, "-> ");
1046 fprint_frame (gdb_stdlog, fi);
1047 fprintf_unfiltered (gdb_stdlog, " }\n");
1053 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
1054 innermost frame). Be careful to not fall off the bottom of the
1055 frame chain and onto the sentinel frame. */
1058 get_next_frame (struct frame_info *this_frame)
1060 if (this_frame->level > 0)
1061 return this_frame->next;
1066 /* Observer for the target_changed event. */
1069 frame_observer_target_changed (struct target_ops *target)
1071 flush_cached_frames ();
1074 /* Flush the entire frame cache. */
1077 flush_cached_frames (void)
1079 /* Since we can't really be sure what the first object allocated was */
1080 obstack_free (&frame_cache_obstack, 0);
1081 obstack_init (&frame_cache_obstack);
1083 current_frame = NULL; /* Invalidate cache */
1084 select_frame (NULL);
1085 annotate_frames_invalid ();
1087 fprintf_unfiltered (gdb_stdlog, "{ flush_cached_frames () }\n");
1090 /* Flush the frame cache, and start a new one if necessary. */
1093 reinit_frame_cache (void)
1095 flush_cached_frames ();
1097 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
1098 if (PIDGET (inferior_ptid) != 0)
1100 select_frame (get_current_frame ());
1104 /* Find where a register is saved (in memory or another register).
1105 The result of frame_register_unwind is just where it is saved
1106 relative to this particular frame.
1108 FIXME: alpha, m32c, and h8300 actually do the transitive operation
1112 frame_register_unwind_location (struct frame_info *this_frame, int regnum,
1113 int *optimizedp, enum lval_type *lvalp,
1114 CORE_ADDR *addrp, int *realnump)
1116 gdb_assert (this_frame == NULL || this_frame->level >= 0);
1118 while (this_frame != NULL)
1120 frame_register_unwind (this_frame, regnum, optimizedp, lvalp,
1121 addrp, realnump, NULL);
1126 if (*lvalp != lval_register)
1130 this_frame = get_next_frame (this_frame);
1134 /* Return a "struct frame_info" corresponding to the frame that called
1135 THIS_FRAME. Returns NULL if there is no such frame.
1137 Unlike get_prev_frame, this function always tries to unwind the
1140 static struct frame_info *
1141 get_prev_frame_1 (struct frame_info *this_frame)
1143 struct frame_info *prev_frame;
1144 struct frame_id this_id;
1146 gdb_assert (this_frame != NULL);
1150 fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame_1 (this_frame=");
1151 if (this_frame != NULL)
1152 fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
1154 fprintf_unfiltered (gdb_stdlog, "<NULL>");
1155 fprintf_unfiltered (gdb_stdlog, ") ");
1158 /* Only try to do the unwind once. */
1159 if (this_frame->prev_p)
1163 fprintf_unfiltered (gdb_stdlog, "-> ");
1164 fprint_frame (gdb_stdlog, this_frame->prev);
1165 fprintf_unfiltered (gdb_stdlog, " // cached \n");
1167 return this_frame->prev;
1169 this_frame->prev_p = 1;
1170 this_frame->stop_reason = UNWIND_NO_REASON;
1172 /* Check that this frame's ID was valid. If it wasn't, don't try to
1173 unwind to the prev frame. Be careful to not apply this test to
1174 the sentinel frame. */
1175 this_id = get_frame_id (this_frame);
1176 if (this_frame->level >= 0 && !frame_id_p (this_id))
1180 fprintf_unfiltered (gdb_stdlog, "-> ");
1181 fprint_frame (gdb_stdlog, NULL);
1182 fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n");
1184 this_frame->stop_reason = UNWIND_NULL_ID;
1188 /* Check that this frame's ID isn't inner to (younger, below, next)
1189 the next frame. This happens when a frame unwind goes backwards.
1190 Exclude signal trampolines (due to sigaltstack the frame ID can
1191 go backwards) and sentinel frames (the test is meaningless). */
1192 if (this_frame->next->level >= 0
1193 && this_frame->next->unwind->type != SIGTRAMP_FRAME
1194 && frame_id_inner (this_id, get_frame_id (this_frame->next)))
1198 fprintf_unfiltered (gdb_stdlog, "-> ");
1199 fprint_frame (gdb_stdlog, NULL);
1200 fprintf_unfiltered (gdb_stdlog, " // this frame ID is inner }\n");
1202 this_frame->stop_reason = UNWIND_INNER_ID;
1206 /* Check that this and the next frame are not identical. If they
1207 are, there is most likely a stack cycle. As with the inner-than
1208 test above, avoid comparing the inner-most and sentinel frames. */
1209 if (this_frame->level > 0
1210 && frame_id_eq (this_id, get_frame_id (this_frame->next)))
1214 fprintf_unfiltered (gdb_stdlog, "-> ");
1215 fprint_frame (gdb_stdlog, NULL);
1216 fprintf_unfiltered (gdb_stdlog, " // this frame has same ID }\n");
1218 this_frame->stop_reason = UNWIND_SAME_ID;
1222 /* Check that this and the next frame do not unwind the PC register
1223 to the same memory location. If they do, then even though they
1224 have different frame IDs, the new frame will be bogus; two
1225 functions can't share a register save slot for the PC. This can
1226 happen when the prologue analyzer finds a stack adjustment, but
1227 no PC save. This check does assume that the "PC register" is
1228 roughly a traditional PC, even if the gdbarch_unwind_pc method
1230 if (this_frame->level > 0
1231 && get_frame_type (this_frame) == NORMAL_FRAME
1232 && get_frame_type (this_frame->next) == NORMAL_FRAME)
1234 int optimized, realnum;
1235 enum lval_type lval, nlval;
1236 CORE_ADDR addr, naddr;
1238 frame_register_unwind_location (this_frame, PC_REGNUM, &optimized,
1239 &lval, &addr, &realnum);
1240 frame_register_unwind_location (get_next_frame (this_frame), PC_REGNUM,
1241 &optimized, &nlval, &naddr, &realnum);
1243 if (lval == lval_memory && lval == nlval && addr == naddr)
1247 fprintf_unfiltered (gdb_stdlog, "-> ");
1248 fprint_frame (gdb_stdlog, NULL);
1249 fprintf_unfiltered (gdb_stdlog, " // no saved PC }\n");
1252 this_frame->stop_reason = UNWIND_NO_SAVED_PC;
1253 this_frame->prev = NULL;
1258 /* Allocate the new frame but do not wire it in to the frame chain.
1259 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1260 frame->next to pull some fancy tricks (of course such code is, by
1261 definition, recursive). Try to prevent it.
1263 There is no reason to worry about memory leaks, should the
1264 remainder of the function fail. The allocated memory will be
1265 quickly reclaimed when the frame cache is flushed, and the `we've
1266 been here before' check above will stop repeated memory
1267 allocation calls. */
1268 prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
1269 prev_frame->level = this_frame->level + 1;
1271 /* Don't yet compute ->unwind (and hence ->type). It is computed
1272 on-demand in get_frame_type, frame_register_unwind, and
1275 /* Don't yet compute the frame's ID. It is computed on-demand by
1278 /* The unwound frame ID is validate at the start of this function,
1279 as part of the logic to decide if that frame should be further
1280 unwound, and not here while the prev frame is being created.
1281 Doing this makes it possible for the user to examine a frame that
1282 has an invalid frame ID.
1284 Some very old VAX code noted: [...] For the sake of argument,
1285 suppose that the stack is somewhat trashed (which is one reason
1286 that "info frame" exists). So, return 0 (indicating we don't
1287 know the address of the arglist) if we don't know what frame this
1291 this_frame->prev = prev_frame;
1292 prev_frame->next = this_frame;
1296 fprintf_unfiltered (gdb_stdlog, "-> ");
1297 fprint_frame (gdb_stdlog, prev_frame);
1298 fprintf_unfiltered (gdb_stdlog, " }\n");
1304 /* Debug routine to print a NULL frame being returned. */
1307 frame_debug_got_null_frame (struct ui_file *file,
1308 struct frame_info *this_frame,
1313 fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame=");
1314 if (this_frame != NULL)
1315 fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
1317 fprintf_unfiltered (gdb_stdlog, "<NULL>");
1318 fprintf_unfiltered (gdb_stdlog, ") -> // %s}\n", reason);
1322 /* Is this (non-sentinel) frame in the "main"() function? */
1325 inside_main_func (struct frame_info *this_frame)
1327 struct minimal_symbol *msymbol;
1330 if (symfile_objfile == 0)
1332 msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile);
1333 if (msymbol == NULL)
1335 /* Make certain that the code, and not descriptor, address is
1337 maddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
1338 SYMBOL_VALUE_ADDRESS (msymbol),
1340 return maddr == get_frame_func (this_frame);
1343 /* Test whether THIS_FRAME is inside the process entry point function. */
1346 inside_entry_func (struct frame_info *this_frame)
1348 return (get_frame_func (this_frame) == entry_point_address ());
1351 /* Return a structure containing various interesting information about
1352 the frame that called THIS_FRAME. Returns NULL if there is entier
1353 no such frame or the frame fails any of a set of target-independent
1354 condition that should terminate the frame chain (e.g., as unwinding
1357 This function should not contain target-dependent tests, such as
1358 checking whether the program-counter is zero. */
1361 get_prev_frame (struct frame_info *this_frame)
1363 struct frame_info *prev_frame;
1365 /* Return the inner-most frame, when the caller passes in NULL. */
1366 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1367 caller should have previously obtained a valid frame using
1368 get_selected_frame() and then called this code - only possibility
1369 I can think of is code behaving badly.
1371 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1372 block_innermost_frame(). It does the sequence: frame = NULL;
1373 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1374 it couldn't be written better, I don't know.
1376 NOTE: cagney/2003-01-11: I suspect what is happening in
1377 block_innermost_frame() is, when the target has no state
1378 (registers, memory, ...), it is still calling this function. The
1379 assumption being that this function will return NULL indicating
1380 that a frame isn't possible, rather than checking that the target
1381 has state and then calling get_current_frame() and
1382 get_prev_frame(). This is a guess mind. */
1383 if (this_frame == NULL)
1385 /* NOTE: cagney/2002-11-09: There was a code segment here that
1386 would error out when CURRENT_FRAME was NULL. The comment
1387 that went with it made the claim ...
1389 ``This screws value_of_variable, which just wants a nice
1390 clean NULL return from block_innermost_frame if there are no
1391 frames. I don't think I've ever seen this message happen
1392 otherwise. And returning NULL here is a perfectly legitimate
1395 Per the above, this code shouldn't even be called with a NULL
1397 frame_debug_got_null_frame (gdb_stdlog, this_frame, "this_frame NULL");
1398 return current_frame;
1401 /* There is always a frame. If this assertion fails, suspect that
1402 something should be calling get_selected_frame() or
1403 get_current_frame(). */
1404 gdb_assert (this_frame != NULL);
1406 /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much
1407 sense to stop unwinding at a dummy frame. One place where a dummy
1408 frame may have an address "inside_main_func" is on HPUX. On HPUX, the
1409 pcsqh register (space register for the instruction at the head of the
1410 instruction queue) cannot be written directly; the only way to set it
1411 is to branch to code that is in the target space. In order to implement
1412 frame dummies on HPUX, the called function is made to jump back to where
1413 the inferior was when the user function was called. If gdb was inside
1414 the main function when we created the dummy frame, the dummy frame will
1415 point inside the main function. */
1416 if (this_frame->level >= 0
1417 && get_frame_type (this_frame) != DUMMY_FRAME
1418 && !backtrace_past_main
1419 && inside_main_func (this_frame))
1420 /* Don't unwind past main(). Note, this is done _before_ the
1421 frame has been marked as previously unwound. That way if the
1422 user later decides to enable unwinds past main(), that will
1423 automatically happen. */
1425 frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside main func");
1429 /* If the user's backtrace limit has been exceeded, stop. We must
1430 add two to the current level; one of those accounts for backtrace_limit
1431 being 1-based and the level being 0-based, and the other accounts for
1432 the level of the new frame instead of the level of the current
1434 if (this_frame->level + 2 > backtrace_limit)
1436 frame_debug_got_null_frame (gdb_stdlog, this_frame,
1437 "backtrace limit exceeded");
1441 /* If we're already inside the entry function for the main objfile,
1442 then it isn't valid. Don't apply this test to a dummy frame -
1443 dummy frame PCs typically land in the entry func. Don't apply
1444 this test to the sentinel frame. Sentinel frames should always
1445 be allowed to unwind. */
1446 /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
1447 wasn't checking for "main" in the minimal symbols. With that
1448 fixed asm-source tests now stop in "main" instead of halting the
1449 backtrace in weird and wonderful ways somewhere inside the entry
1450 file. Suspect that tests for inside the entry file/func were
1451 added to work around that (now fixed) case. */
1452 /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
1453 suggested having the inside_entry_func test use the
1454 inside_main_func() msymbol trick (along with entry_point_address()
1455 I guess) to determine the address range of the start function.
1456 That should provide a far better stopper than the current
1458 /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler
1459 applied tail-call optimizations to main so that a function called
1460 from main returns directly to the caller of main. Since we don't
1461 stop at main, we should at least stop at the entry point of the
1463 if (!backtrace_past_entry
1464 && get_frame_type (this_frame) != DUMMY_FRAME && this_frame->level >= 0
1465 && inside_entry_func (this_frame))
1467 frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside entry func");
1471 /* Assume that the only way to get a zero PC is through something
1472 like a SIGSEGV or a dummy frame, and hence that NORMAL frames
1473 will never unwind a zero PC. */
1474 if (this_frame->level > 0
1475 && get_frame_type (this_frame) == NORMAL_FRAME
1476 && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME
1477 && get_frame_pc (this_frame) == 0)
1479 frame_debug_got_null_frame (gdb_stdlog, this_frame, "zero PC");
1483 return get_prev_frame_1 (this_frame);
1487 get_frame_pc (struct frame_info *frame)
1489 gdb_assert (frame->next != NULL);
1490 return frame_pc_unwind (frame->next);
1493 /* Return an address of that falls within the frame's code block. */
1496 frame_unwind_address_in_block (struct frame_info *next_frame)
1498 /* A draft address. */
1499 CORE_ADDR pc = frame_pc_unwind (next_frame);
1501 /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
1502 and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
1503 frame's PC ends up pointing at the instruction fallowing the
1504 "call". Adjust that PC value so that it falls on the call
1505 instruction (which, hopefully, falls within THIS frame's code
1506 block. So far it's proved to be a very good approximation. See
1507 get_frame_type() for why ->type can't be used. */
1508 if (next_frame->level >= 0
1509 && get_frame_type (next_frame) == NORMAL_FRAME)
1515 get_frame_address_in_block (struct frame_info *this_frame)
1517 return frame_unwind_address_in_block (this_frame->next);
1521 pc_notcurrent (struct frame_info *frame)
1523 /* If FRAME is not the innermost frame, that normally means that
1524 FRAME->pc points at the return instruction (which is *after* the
1525 call instruction), and we want to get the line containing the
1526 call (because the call is where the user thinks the program is).
1527 However, if the next frame is either a SIGTRAMP_FRAME or a
1528 DUMMY_FRAME, then the next frame will contain a saved interrupt
1529 PC and such a PC indicates the current (rather than next)
1530 instruction/line, consequently, for such cases, want to get the
1531 line containing fi->pc. */
1532 struct frame_info *next = get_next_frame (frame);
1533 int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME);
1538 find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal)
1540 (*sal) = find_pc_line (get_frame_pc (frame), pc_notcurrent (frame));
1543 /* Per "frame.h", return the ``address'' of the frame. Code should
1544 really be using get_frame_id(). */
1546 get_frame_base (struct frame_info *fi)
1548 return get_frame_id (fi).stack_addr;
1551 /* High-level offsets into the frame. Used by the debug info. */
1554 get_frame_base_address (struct frame_info *fi)
1556 if (get_frame_type (fi) != NORMAL_FRAME)
1558 if (fi->base == NULL)
1559 fi->base = frame_base_find_by_frame (fi->next);
1560 /* Sneaky: If the low-level unwind and high-level base code share a
1561 common unwinder, let them share the prologue cache. */
1562 if (fi->base->unwind == fi->unwind)
1563 return fi->base->this_base (fi->next, &fi->prologue_cache);
1564 return fi->base->this_base (fi->next, &fi->base_cache);
1568 get_frame_locals_address (struct frame_info *fi)
1571 if (get_frame_type (fi) != NORMAL_FRAME)
1573 /* If there isn't a frame address method, find it. */
1574 if (fi->base == NULL)
1575 fi->base = frame_base_find_by_frame (fi->next);
1576 /* Sneaky: If the low-level unwind and high-level base code share a
1577 common unwinder, let them share the prologue cache. */
1578 if (fi->base->unwind == fi->unwind)
1579 cache = &fi->prologue_cache;
1581 cache = &fi->base_cache;
1582 return fi->base->this_locals (fi->next, cache);
1586 get_frame_args_address (struct frame_info *fi)
1589 if (get_frame_type (fi) != NORMAL_FRAME)
1591 /* If there isn't a frame address method, find it. */
1592 if (fi->base == NULL)
1593 fi->base = frame_base_find_by_frame (fi->next);
1594 /* Sneaky: If the low-level unwind and high-level base code share a
1595 common unwinder, let them share the prologue cache. */
1596 if (fi->base->unwind == fi->unwind)
1597 cache = &fi->prologue_cache;
1599 cache = &fi->base_cache;
1600 return fi->base->this_args (fi->next, cache);
1603 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1604 or -1 for a NULL frame. */
1607 frame_relative_level (struct frame_info *fi)
1616 get_frame_type (struct frame_info *frame)
1618 if (frame->unwind == NULL)
1619 /* Initialize the frame's unwinder because that's what
1620 provides the frame's type. */
1621 frame->unwind = frame_unwind_find_by_frame (frame->next,
1622 &frame->prologue_cache);
1623 return frame->unwind->type;
1627 deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc)
1630 fprintf_unfiltered (gdb_stdlog,
1631 "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
1632 frame->level, paddr_nz (pc));
1633 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
1634 maintaining a locally allocated frame object. Since such frames
1635 are not in the frame chain, it isn't possible to assume that the
1636 frame has a next. Sigh. */
1637 if (frame->next != NULL)
1639 /* While we're at it, update this frame's cached PC value, found
1640 in the next frame. Oh for the day when "struct frame_info"
1641 is opaque and this hack on hack can just go away. */
1642 frame->next->prev_pc.value = pc;
1643 frame->next->prev_pc.p = 1;
1648 deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base)
1651 fprintf_unfiltered (gdb_stdlog,
1652 "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
1653 frame->level, paddr_nz (base));
1654 /* See comment in "frame.h". */
1655 frame->this_id.value.stack_addr = base;
1658 /* Memory access methods. */
1661 get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
1662 gdb_byte *buf, int len)
1664 read_memory (addr, buf, len);
1668 get_frame_memory_signed (struct frame_info *this_frame, CORE_ADDR addr,
1671 return read_memory_integer (addr, len);
1675 get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr,
1678 return read_memory_unsigned_integer (addr, len);
1682 safe_frame_unwind_memory (struct frame_info *this_frame,
1683 CORE_ADDR addr, gdb_byte *buf, int len)
1685 /* NOTE: read_memory_nobpt returns zero on success! */
1686 return !read_memory_nobpt (addr, buf, len);
1689 /* Architecture method. */
1692 get_frame_arch (struct frame_info *this_frame)
1694 return current_gdbarch;
1697 /* Stack pointer methods. */
1700 get_frame_sp (struct frame_info *this_frame)
1702 return frame_sp_unwind (this_frame->next);
1706 frame_sp_unwind (struct frame_info *next_frame)
1708 /* Normality - an architecture that provides a way of obtaining any
1709 frame inner-most address. */
1710 if (gdbarch_unwind_sp_p (current_gdbarch))
1711 return gdbarch_unwind_sp (current_gdbarch, next_frame);
1712 /* Things are looking grim. If it's the inner-most frame and there
1713 is a TARGET_READ_SP, then that can be used. */
1714 if (next_frame->level < 0 && TARGET_READ_SP_P ())
1715 return TARGET_READ_SP ();
1716 /* Now things are really are grim. Hope that the value returned by
1717 the SP_REGNUM register is meaningful. */
1721 frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp);
1724 internal_error (__FILE__, __LINE__, _("Missing unwind SP method"));
1727 /* Return the reason why we can't unwind past FRAME. */
1729 enum unwind_stop_reason
1730 get_frame_unwind_stop_reason (struct frame_info *frame)
1732 /* If we haven't tried to unwind past this point yet, then assume
1733 that unwinding would succeed. */
1734 if (frame->prev_p == 0)
1735 return UNWIND_NO_REASON;
1737 /* Otherwise, we set a reason when we succeeded (or failed) to
1739 return frame->stop_reason;
1742 /* Return a string explaining REASON. */
1745 frame_stop_reason_string (enum unwind_stop_reason reason)
1749 case UNWIND_NULL_ID:
1750 return _("unwinder did not report frame ID");
1752 case UNWIND_INNER_ID:
1753 return _("previous frame inner to this frame (corrupt stack?)");
1755 case UNWIND_SAME_ID:
1756 return _("previous frame identical to this frame (corrupt stack?)");
1758 case UNWIND_NO_SAVED_PC:
1759 return _("frame did not save the PC");
1761 case UNWIND_NO_REASON:
1762 case UNWIND_FIRST_ERROR:
1764 internal_error (__FILE__, __LINE__,
1765 "Invalid frame stop reason");
1769 extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */
1771 static struct cmd_list_element *set_backtrace_cmdlist;
1772 static struct cmd_list_element *show_backtrace_cmdlist;
1775 set_backtrace_cmd (char *args, int from_tty)
1777 help_list (set_backtrace_cmdlist, "set backtrace ", -1, gdb_stdout);
1781 show_backtrace_cmd (char *args, int from_tty)
1783 cmd_show_list (show_backtrace_cmdlist, from_tty, "");
1787 _initialize_frame (void)
1789 obstack_init (&frame_cache_obstack);
1791 observer_attach_target_changed (frame_observer_target_changed);
1793 add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, _("\
1794 Set backtrace specific variables.\n\
1795 Configure backtrace variables such as the backtrace limit"),
1796 &set_backtrace_cmdlist, "set backtrace ",
1797 0/*allow-unknown*/, &setlist);
1798 add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, _("\
1799 Show backtrace specific variables\n\
1800 Show backtrace variables such as the backtrace limit"),
1801 &show_backtrace_cmdlist, "show backtrace ",
1802 0/*allow-unknown*/, &showlist);
1804 add_setshow_boolean_cmd ("past-main", class_obscure,
1805 &backtrace_past_main, _("\
1806 Set whether backtraces should continue past \"main\"."), _("\
1807 Show whether backtraces should continue past \"main\"."), _("\
1808 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1809 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1810 of the stack trace."),
1812 show_backtrace_past_main,
1813 &set_backtrace_cmdlist,
1814 &show_backtrace_cmdlist);
1816 add_setshow_boolean_cmd ("past-entry", class_obscure,
1817 &backtrace_past_entry, _("\
1818 Set whether backtraces should continue past the entry point of a program."),
1820 Show whether backtraces should continue past the entry point of a program."),
1822 Normally there are no callers beyond the entry point of a program, so GDB\n\
1823 will terminate the backtrace there. Set this variable if you need to see \n\
1824 the rest of the stack trace."),
1826 show_backtrace_past_entry,
1827 &set_backtrace_cmdlist,
1828 &show_backtrace_cmdlist);
1830 add_setshow_integer_cmd ("limit", class_obscure,
1831 &backtrace_limit, _("\
1832 Set an upper bound on the number of backtrace levels."), _("\
1833 Show the upper bound on the number of backtrace levels."), _("\
1834 No more than the specified number of frames can be displayed or examined.\n\
1835 Zero is unlimited."),
1837 show_backtrace_limit,
1838 &set_backtrace_cmdlist,
1839 &show_backtrace_cmdlist);
1841 /* Debug this files internals. */
1842 add_setshow_zinteger_cmd ("frame", class_maintenance, &frame_debug, _("\
1843 Set frame debugging."), _("\
1844 Show frame debugging."), _("\
1845 When non-zero, frame specific internal debugging is enabled."),
1848 &setdebuglist, &showdebuglist);