1 /* Cache and manage frames for GDB, the GNU debugger.
3 Copyright (C) 1986, 1987, 1989, 1991, 1994, 1995, 1996, 1998, 2000, 2001,
4 2002, 2003, 2004, 2007 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 = gdbarch_inner_than (current_gdbarch, 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, enum frame_type this_type)
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, this_type);
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, get_frame_type (fi));
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 struct frame_info *prev_frame;
518 struct regcache *scratch;
519 struct cleanup *cleanups;
521 /* Ensure that we have a frame to pop to. */
522 prev_frame = get_prev_frame_1 (this_frame);
525 error (_("Cannot pop the initial frame."));
527 /* Make a copy of all the register values unwound from this frame.
528 Save them in a scratch buffer so that there isn't a race between
529 trying to extract the old values from the current_regcache while
530 at the same time writing new values into that same cache. */
531 scratch = frame_save_as_regcache (prev_frame);
532 cleanups = make_cleanup_regcache_xfree (scratch);
534 /* FIXME: cagney/2003-03-16: It should be possible to tell the
535 target's register cache that it is about to be hit with a burst
536 register transfer and that the sequence of register writes should
537 be batched. The pair target_prepare_to_store() and
538 target_store_registers() kind of suggest this functionality.
539 Unfortunately, they don't implement it. Their lack of a formal
540 definition can lead to targets writing back bogus values
541 (arguably a bug in the target code mind). */
542 /* Now copy those saved registers into the current regcache.
543 Here, regcache_cpy() calls regcache_restore(). */
544 regcache_cpy (current_regcache, scratch);
545 do_cleanups (cleanups);
547 /* We've made right mess of GDB's local state, just discard
549 reinit_frame_cache ();
553 frame_register_unwind (struct frame_info *frame, int regnum,
554 int *optimizedp, enum lval_type *lvalp,
555 CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp)
557 struct frame_unwind_cache *cache;
561 fprintf_unfiltered (gdb_stdlog, "\
562 { frame_register_unwind (frame=%d,regnum=%d(%s),...) ",
563 frame->level, regnum,
564 frame_map_regnum_to_name (frame, regnum));
567 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
568 that the value proper does not need to be fetched. */
569 gdb_assert (optimizedp != NULL);
570 gdb_assert (lvalp != NULL);
571 gdb_assert (addrp != NULL);
572 gdb_assert (realnump != NULL);
573 /* gdb_assert (bufferp != NULL); */
575 /* NOTE: cagney/2002-11-27: A program trying to unwind a NULL frame
576 is broken. There is always a frame. If there, for some reason,
577 isn't a frame, there is some pretty busted code as it should have
578 detected the problem before calling here. */
579 gdb_assert (frame != NULL);
581 /* Find the unwinder. */
582 if (frame->unwind == NULL)
583 frame->unwind = frame_unwind_find_by_frame (frame->next,
584 &frame->prologue_cache);
586 /* Ask this frame to unwind its register. See comment in
587 "frame-unwind.h" for why NEXT frame and this unwind cache are
589 frame->unwind->prev_register (frame->next, &frame->prologue_cache, regnum,
590 optimizedp, lvalp, addrp, realnump, bufferp);
594 fprintf_unfiltered (gdb_stdlog, "->");
595 fprintf_unfiltered (gdb_stdlog, " *optimizedp=%d", (*optimizedp));
596 fprintf_unfiltered (gdb_stdlog, " *lvalp=%d", (int) (*lvalp));
597 fprintf_unfiltered (gdb_stdlog, " *addrp=0x%s", paddr_nz ((*addrp)));
598 fprintf_unfiltered (gdb_stdlog, " *bufferp=");
600 fprintf_unfiltered (gdb_stdlog, "<NULL>");
604 const unsigned char *buf = bufferp;
605 fprintf_unfiltered (gdb_stdlog, "[");
606 for (i = 0; i < register_size (current_gdbarch, regnum); i++)
607 fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
608 fprintf_unfiltered (gdb_stdlog, "]");
610 fprintf_unfiltered (gdb_stdlog, " }\n");
615 frame_register (struct frame_info *frame, int regnum,
616 int *optimizedp, enum lval_type *lvalp,
617 CORE_ADDR *addrp, int *realnump, gdb_byte *bufferp)
619 /* Require all but BUFFERP to be valid. A NULL BUFFERP indicates
620 that the value proper does not need to be fetched. */
621 gdb_assert (optimizedp != NULL);
622 gdb_assert (lvalp != NULL);
623 gdb_assert (addrp != NULL);
624 gdb_assert (realnump != NULL);
625 /* gdb_assert (bufferp != NULL); */
627 /* Obtain the register value by unwinding the register from the next
628 (more inner frame). */
629 gdb_assert (frame != NULL && frame->next != NULL);
630 frame_register_unwind (frame->next, regnum, optimizedp, lvalp, addrp,
635 frame_unwind_register (struct frame_info *frame, int regnum, gdb_byte *buf)
641 frame_register_unwind (frame, regnum, &optimized, &lval, &addr,
646 get_frame_register (struct frame_info *frame,
647 int regnum, gdb_byte *buf)
649 frame_unwind_register (frame->next, regnum, buf);
653 frame_unwind_register_signed (struct frame_info *frame, int regnum)
655 gdb_byte buf[MAX_REGISTER_SIZE];
656 frame_unwind_register (frame, regnum, buf);
657 return extract_signed_integer (buf, register_size (get_frame_arch (frame),
662 get_frame_register_signed (struct frame_info *frame, int regnum)
664 return frame_unwind_register_signed (frame->next, regnum);
668 frame_unwind_register_unsigned (struct frame_info *frame, int regnum)
670 gdb_byte buf[MAX_REGISTER_SIZE];
671 frame_unwind_register (frame, regnum, buf);
672 return extract_unsigned_integer (buf, register_size (get_frame_arch (frame),
677 get_frame_register_unsigned (struct frame_info *frame, int regnum)
679 return frame_unwind_register_unsigned (frame->next, regnum);
683 frame_unwind_unsigned_register (struct frame_info *frame, int regnum,
686 gdb_byte buf[MAX_REGISTER_SIZE];
687 frame_unwind_register (frame, regnum, buf);
688 (*val) = extract_unsigned_integer (buf,
689 register_size (get_frame_arch (frame),
694 put_frame_register (struct frame_info *frame, int regnum,
697 struct gdbarch *gdbarch = get_frame_arch (frame);
702 frame_register (frame, regnum, &optim, &lval, &addr, &realnum, NULL);
704 error (_("Attempt to assign to a value that was optimized out."));
709 /* FIXME: write_memory doesn't yet take constant buffers.
711 gdb_byte tmp[MAX_REGISTER_SIZE];
712 memcpy (tmp, buf, register_size (gdbarch, regnum));
713 write_memory (addr, tmp, register_size (gdbarch, regnum));
717 regcache_cooked_write (current_regcache, realnum, buf);
720 error (_("Attempt to assign to an unmodifiable value."));
724 /* frame_register_read ()
726 Find and return the value of REGNUM for the specified stack frame.
727 The number of bytes copied is REGISTER_SIZE (REGNUM).
729 Returns 0 if the register value could not be found. */
732 frame_register_read (struct frame_info *frame, int regnum,
739 frame_register (frame, regnum, &optimized, &lval, &addr, &realnum, myaddr);
745 get_frame_register_bytes (struct frame_info *frame, int regnum,
746 CORE_ADDR offset, int len, gdb_byte *myaddr)
748 struct gdbarch *gdbarch = get_frame_arch (frame);
750 /* Skip registers wholly inside of OFFSET. */
751 while (offset >= register_size (gdbarch, regnum))
753 offset -= register_size (gdbarch, regnum);
760 int curr_len = register_size (gdbarch, regnum) - offset;
764 if (curr_len == register_size (gdbarch, regnum))
766 if (!frame_register_read (frame, regnum, myaddr))
771 gdb_byte buf[MAX_REGISTER_SIZE];
772 if (!frame_register_read (frame, regnum, buf))
774 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);
825 /* Map between a frame register number and its name. A frame register
826 space is a superset of the cooked register space --- it also
827 includes builtin registers. */
830 frame_map_name_to_regnum (struct frame_info *frame, const char *name, int len)
832 return user_reg_map_name_to_regnum (get_frame_arch (frame), name, len);
836 frame_map_regnum_to_name (struct frame_info *frame, int regnum)
838 return user_reg_map_regnum_to_name (get_frame_arch (frame), regnum);
841 /* Create a sentinel frame. */
843 static struct frame_info *
844 create_sentinel_frame (struct regcache *regcache)
846 struct frame_info *frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
848 /* Explicitly initialize the sentinel frame's cache. Provide it
849 with the underlying regcache. In the future additional
850 information, such as the frame's thread will be added. */
851 frame->prologue_cache = sentinel_frame_cache (regcache);
852 /* For the moment there is only one sentinel frame implementation. */
853 frame->unwind = sentinel_frame_unwind;
854 /* Link this frame back to itself. The frame is self referential
855 (the unwound PC is the same as the pc), so make it so. */
857 /* Make the sentinel frame's ID valid, but invalid. That way all
858 comparisons with it should fail. */
859 frame->this_id.p = 1;
860 frame->this_id.value = null_frame_id;
863 fprintf_unfiltered (gdb_stdlog, "{ create_sentinel_frame (...) -> ");
864 fprint_frame (gdb_stdlog, frame);
865 fprintf_unfiltered (gdb_stdlog, " }\n");
870 /* Info about the innermost stack frame (contents of FP register) */
872 static struct frame_info *current_frame;
874 /* Cache for frame addresses already read by gdb. Valid only while
875 inferior is stopped. Control variables for the frame cache should
876 be local to this module. */
878 static struct obstack frame_cache_obstack;
881 frame_obstack_zalloc (unsigned long size)
883 void *data = obstack_alloc (&frame_cache_obstack, size);
884 memset (data, 0, size);
888 /* Return the innermost (currently executing) stack frame. This is
889 split into two functions. The function unwind_to_current_frame()
890 is wrapped in catch exceptions so that, even when the unwind of the
891 sentinel frame fails, the function still returns a stack frame. */
894 unwind_to_current_frame (struct ui_out *ui_out, void *args)
896 struct frame_info *frame = get_prev_frame (args);
897 /* A sentinel frame can fail to unwind, e.g., because its PC value
898 lands in somewhere like start. */
901 current_frame = frame;
906 get_current_frame (void)
908 /* First check, and report, the lack of registers. Having GDB
909 report "No stack!" or "No memory" when the target doesn't even
910 have registers is very confusing. Besides, "printcmd.exp"
911 explicitly checks that ``print $pc'' with no registers prints "No
913 if (!target_has_registers)
914 error (_("No registers."));
915 if (!target_has_stack)
916 error (_("No stack."));
917 if (!target_has_memory)
918 error (_("No memory."));
919 if (current_frame == NULL)
921 struct frame_info *sentinel_frame =
922 create_sentinel_frame (current_regcache);
923 if (catch_exceptions (uiout, unwind_to_current_frame, sentinel_frame,
924 RETURN_MASK_ERROR) != 0)
926 /* Oops! Fake a current frame? Is this useful? It has a PC
927 of zero, for instance. */
928 current_frame = sentinel_frame;
931 return current_frame;
934 /* The "selected" stack frame is used by default for local and arg
935 access. May be zero, for no selected frame. */
937 static struct frame_info *selected_frame;
939 /* Return the selected frame. Always non-NULL (unless there isn't an
940 inferior sufficient for creating a frame) in which case an error is
944 get_selected_frame (const char *message)
946 if (selected_frame == NULL)
948 if (message != NULL && (!target_has_registers
950 || !target_has_memory))
951 error (("%s"), message);
952 /* Hey! Don't trust this. It should really be re-finding the
953 last selected frame of the currently selected thread. This,
954 though, is better than nothing. */
955 select_frame (get_current_frame ());
957 /* There is always a frame. */
958 gdb_assert (selected_frame != NULL);
959 return selected_frame;
962 /* This is a variant of get_selected_frame() which can be called when
963 the inferior does not have a frame; in that case it will return
964 NULL instead of calling error(). */
967 deprecated_safe_get_selected_frame (void)
969 if (!target_has_registers || !target_has_stack || !target_has_memory)
971 return get_selected_frame (NULL);
974 /* Select frame FI (or NULL - to invalidate the current frame). */
977 select_frame (struct frame_info *fi)
982 /* NOTE: cagney/2002-05-04: FI can be NULL. This occurs when the
983 frame is being invalidated. */
984 if (deprecated_selected_frame_level_changed_hook)
985 deprecated_selected_frame_level_changed_hook (frame_relative_level (fi));
987 /* FIXME: kseitz/2002-08-28: It would be nice to call
988 selected_frame_level_changed_event() right here, but due to limitations
989 in the current interfaces, we would end up flooding UIs with events
990 because select_frame() is used extensively internally.
992 Once we have frame-parameterized frame (and frame-related) commands,
993 the event notification can be moved here, since this function will only
994 be called when the user's selected frame is being changed. */
996 /* Ensure that symbols for this frame are read in. Also, determine the
997 source language of this frame, and switch to it if desired. */
1000 /* We retrieve the frame's symtab by using the frame PC. However
1001 we cannot use the frame PC as-is, because it usually points to
1002 the instruction following the "call", which is sometimes the
1003 first instruction of another function. So we rely on
1004 get_frame_address_in_block() which provides us with a PC which
1005 is guaranteed to be inside the frame's code block. */
1006 s = find_pc_symtab (get_frame_address_in_block (fi));
1008 && s->language != current_language->la_language
1009 && s->language != language_unknown
1010 && language_mode == language_mode_auto)
1012 set_language (s->language);
1017 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
1018 Always returns a non-NULL value. */
1021 create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
1023 struct frame_info *fi;
1027 fprintf_unfiltered (gdb_stdlog,
1028 "{ create_new_frame (addr=0x%s, pc=0x%s) ",
1029 paddr_nz (addr), paddr_nz (pc));
1032 fi = FRAME_OBSTACK_ZALLOC (struct frame_info);
1034 fi->next = create_sentinel_frame (current_regcache);
1036 /* Select/initialize both the unwind function and the frame's type
1038 fi->unwind = frame_unwind_find_by_frame (fi->next, &fi->prologue_cache);
1041 deprecated_update_frame_base_hack (fi, addr);
1042 deprecated_update_frame_pc_hack (fi, pc);
1046 fprintf_unfiltered (gdb_stdlog, "-> ");
1047 fprint_frame (gdb_stdlog, fi);
1048 fprintf_unfiltered (gdb_stdlog, " }\n");
1054 /* Return the frame that THIS_FRAME calls (NULL if THIS_FRAME is the
1055 innermost frame). Be careful to not fall off the bottom of the
1056 frame chain and onto the sentinel frame. */
1059 get_next_frame (struct frame_info *this_frame)
1061 if (this_frame->level > 0)
1062 return this_frame->next;
1067 /* Observer for the target_changed event. */
1070 frame_observer_target_changed (struct target_ops *target)
1072 reinit_frame_cache ();
1075 /* Flush the entire frame cache. */
1078 reinit_frame_cache (void)
1080 /* Since we can't really be sure what the first object allocated was */
1081 obstack_free (&frame_cache_obstack, 0);
1082 obstack_init (&frame_cache_obstack);
1084 current_frame = NULL; /* Invalidate cache */
1085 select_frame (NULL);
1086 annotate_frames_invalid ();
1088 fprintf_unfiltered (gdb_stdlog, "{ reinit_frame_cache () }\n");
1091 /* Find where a register is saved (in memory or another register).
1092 The result of frame_register_unwind is just where it is saved
1093 relative to this particular frame. */
1096 frame_register_unwind_location (struct frame_info *this_frame, int regnum,
1097 int *optimizedp, enum lval_type *lvalp,
1098 CORE_ADDR *addrp, int *realnump)
1100 gdb_assert (this_frame == NULL || this_frame->level >= 0);
1102 while (this_frame != NULL)
1104 frame_register_unwind (this_frame, regnum, optimizedp, lvalp,
1105 addrp, realnump, NULL);
1110 if (*lvalp != lval_register)
1114 this_frame = get_next_frame (this_frame);
1118 /* Return a "struct frame_info" corresponding to the frame that called
1119 THIS_FRAME. Returns NULL if there is no such frame.
1121 Unlike get_prev_frame, this function always tries to unwind the
1124 static struct frame_info *
1125 get_prev_frame_1 (struct frame_info *this_frame)
1127 struct frame_info *prev_frame;
1128 struct frame_id this_id;
1130 gdb_assert (this_frame != NULL);
1134 fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame_1 (this_frame=");
1135 if (this_frame != NULL)
1136 fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
1138 fprintf_unfiltered (gdb_stdlog, "<NULL>");
1139 fprintf_unfiltered (gdb_stdlog, ") ");
1142 /* Only try to do the unwind once. */
1143 if (this_frame->prev_p)
1147 fprintf_unfiltered (gdb_stdlog, "-> ");
1148 fprint_frame (gdb_stdlog, this_frame->prev);
1149 fprintf_unfiltered (gdb_stdlog, " // cached \n");
1151 return this_frame->prev;
1153 this_frame->prev_p = 1;
1154 this_frame->stop_reason = UNWIND_NO_REASON;
1156 /* Check that this frame's ID was valid. If it wasn't, don't try to
1157 unwind to the prev frame. Be careful to not apply this test to
1158 the sentinel frame. */
1159 this_id = get_frame_id (this_frame);
1160 if (this_frame->level >= 0 && !frame_id_p (this_id))
1164 fprintf_unfiltered (gdb_stdlog, "-> ");
1165 fprint_frame (gdb_stdlog, NULL);
1166 fprintf_unfiltered (gdb_stdlog, " // this ID is NULL }\n");
1168 this_frame->stop_reason = UNWIND_NULL_ID;
1172 /* Check that this frame's ID isn't inner to (younger, below, next)
1173 the next frame. This happens when a frame unwind goes backwards.
1174 Exclude signal trampolines (due to sigaltstack the frame ID can
1175 go backwards) and sentinel frames (the test is meaningless). */
1176 if (this_frame->next->level >= 0
1177 && this_frame->next->unwind->type != SIGTRAMP_FRAME
1178 && frame_id_inner (this_id, get_frame_id (this_frame->next)))
1182 fprintf_unfiltered (gdb_stdlog, "-> ");
1183 fprint_frame (gdb_stdlog, NULL);
1184 fprintf_unfiltered (gdb_stdlog, " // this frame ID is inner }\n");
1186 this_frame->stop_reason = UNWIND_INNER_ID;
1190 /* Check that this and the next frame are not identical. If they
1191 are, there is most likely a stack cycle. As with the inner-than
1192 test above, avoid comparing the inner-most and sentinel frames. */
1193 if (this_frame->level > 0
1194 && frame_id_eq (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 has same ID }\n");
1202 this_frame->stop_reason = UNWIND_SAME_ID;
1206 /* Check that this and the next frame do not unwind the PC register
1207 to the same memory location. If they do, then even though they
1208 have different frame IDs, the new frame will be bogus; two
1209 functions can't share a register save slot for the PC. This can
1210 happen when the prologue analyzer finds a stack adjustment, but
1213 This check does assume that the "PC register" is roughly a
1214 traditional PC, even if the gdbarch_unwind_pc method adjusts
1215 it (we do not rely on the value, only on the unwound PC being
1216 dependent on this value). A potential improvement would be
1217 to have the frame prev_pc method and the gdbarch unwind_pc
1218 method set the same lval and location information as
1219 frame_register_unwind. */
1220 if (this_frame->level > 0
1222 && get_frame_type (this_frame) == NORMAL_FRAME
1223 && get_frame_type (this_frame->next) == NORMAL_FRAME)
1225 int optimized, realnum;
1226 enum lval_type lval, nlval;
1227 CORE_ADDR addr, naddr;
1229 frame_register_unwind_location (this_frame, PC_REGNUM, &optimized,
1230 &lval, &addr, &realnum);
1231 frame_register_unwind_location (get_next_frame (this_frame), PC_REGNUM,
1232 &optimized, &nlval, &naddr, &realnum);
1234 if (lval == lval_memory && lval == nlval && addr == naddr)
1238 fprintf_unfiltered (gdb_stdlog, "-> ");
1239 fprint_frame (gdb_stdlog, NULL);
1240 fprintf_unfiltered (gdb_stdlog, " // no saved PC }\n");
1243 this_frame->stop_reason = UNWIND_NO_SAVED_PC;
1244 this_frame->prev = NULL;
1249 /* Allocate the new frame but do not wire it in to the frame chain.
1250 Some (bad) code in INIT_FRAME_EXTRA_INFO tries to look along
1251 frame->next to pull some fancy tricks (of course such code is, by
1252 definition, recursive). Try to prevent it.
1254 There is no reason to worry about memory leaks, should the
1255 remainder of the function fail. The allocated memory will be
1256 quickly reclaimed when the frame cache is flushed, and the `we've
1257 been here before' check above will stop repeated memory
1258 allocation calls. */
1259 prev_frame = FRAME_OBSTACK_ZALLOC (struct frame_info);
1260 prev_frame->level = this_frame->level + 1;
1262 /* Don't yet compute ->unwind (and hence ->type). It is computed
1263 on-demand in get_frame_type, frame_register_unwind, and
1266 /* Don't yet compute the frame's ID. It is computed on-demand by
1269 /* The unwound frame ID is validate at the start of this function,
1270 as part of the logic to decide if that frame should be further
1271 unwound, and not here while the prev frame is being created.
1272 Doing this makes it possible for the user to examine a frame that
1273 has an invalid frame ID.
1275 Some very old VAX code noted: [...] For the sake of argument,
1276 suppose that the stack is somewhat trashed (which is one reason
1277 that "info frame" exists). So, return 0 (indicating we don't
1278 know the address of the arglist) if we don't know what frame this
1282 this_frame->prev = prev_frame;
1283 prev_frame->next = this_frame;
1287 fprintf_unfiltered (gdb_stdlog, "-> ");
1288 fprint_frame (gdb_stdlog, prev_frame);
1289 fprintf_unfiltered (gdb_stdlog, " }\n");
1295 /* Debug routine to print a NULL frame being returned. */
1298 frame_debug_got_null_frame (struct ui_file *file,
1299 struct frame_info *this_frame,
1304 fprintf_unfiltered (gdb_stdlog, "{ get_prev_frame (this_frame=");
1305 if (this_frame != NULL)
1306 fprintf_unfiltered (gdb_stdlog, "%d", this_frame->level);
1308 fprintf_unfiltered (gdb_stdlog, "<NULL>");
1309 fprintf_unfiltered (gdb_stdlog, ") -> // %s}\n", reason);
1313 /* Is this (non-sentinel) frame in the "main"() function? */
1316 inside_main_func (struct frame_info *this_frame)
1318 struct minimal_symbol *msymbol;
1321 if (symfile_objfile == 0)
1323 msymbol = lookup_minimal_symbol (main_name (), NULL, symfile_objfile);
1324 if (msymbol == NULL)
1326 /* Make certain that the code, and not descriptor, address is
1328 maddr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
1329 SYMBOL_VALUE_ADDRESS (msymbol),
1331 return maddr == get_frame_func (this_frame);
1334 /* Test whether THIS_FRAME is inside the process entry point function. */
1337 inside_entry_func (struct frame_info *this_frame)
1339 return (get_frame_func (this_frame) == entry_point_address ());
1342 /* Return a structure containing various interesting information about
1343 the frame that called THIS_FRAME. Returns NULL if there is entier
1344 no such frame or the frame fails any of a set of target-independent
1345 condition that should terminate the frame chain (e.g., as unwinding
1348 This function should not contain target-dependent tests, such as
1349 checking whether the program-counter is zero. */
1352 get_prev_frame (struct frame_info *this_frame)
1354 struct frame_info *prev_frame;
1356 /* Return the inner-most frame, when the caller passes in NULL. */
1357 /* NOTE: cagney/2002-11-09: Not sure how this would happen. The
1358 caller should have previously obtained a valid frame using
1359 get_selected_frame() and then called this code - only possibility
1360 I can think of is code behaving badly.
1362 NOTE: cagney/2003-01-10: Talk about code behaving badly. Check
1363 block_innermost_frame(). It does the sequence: frame = NULL;
1364 while (1) { frame = get_prev_frame (frame); .... }. Ulgh! Why
1365 it couldn't be written better, I don't know.
1367 NOTE: cagney/2003-01-11: I suspect what is happening in
1368 block_innermost_frame() is, when the target has no state
1369 (registers, memory, ...), it is still calling this function. The
1370 assumption being that this function will return NULL indicating
1371 that a frame isn't possible, rather than checking that the target
1372 has state and then calling get_current_frame() and
1373 get_prev_frame(). This is a guess mind. */
1374 if (this_frame == NULL)
1376 /* NOTE: cagney/2002-11-09: There was a code segment here that
1377 would error out when CURRENT_FRAME was NULL. The comment
1378 that went with it made the claim ...
1380 ``This screws value_of_variable, which just wants a nice
1381 clean NULL return from block_innermost_frame if there are no
1382 frames. I don't think I've ever seen this message happen
1383 otherwise. And returning NULL here is a perfectly legitimate
1386 Per the above, this code shouldn't even be called with a NULL
1388 frame_debug_got_null_frame (gdb_stdlog, this_frame, "this_frame NULL");
1389 return current_frame;
1392 /* There is always a frame. If this assertion fails, suspect that
1393 something should be calling get_selected_frame() or
1394 get_current_frame(). */
1395 gdb_assert (this_frame != NULL);
1397 /* tausq/2004-12-07: Dummy frames are skipped because it doesn't make much
1398 sense to stop unwinding at a dummy frame. One place where a dummy
1399 frame may have an address "inside_main_func" is on HPUX. On HPUX, the
1400 pcsqh register (space register for the instruction at the head of the
1401 instruction queue) cannot be written directly; the only way to set it
1402 is to branch to code that is in the target space. In order to implement
1403 frame dummies on HPUX, the called function is made to jump back to where
1404 the inferior was when the user function was called. If gdb was inside
1405 the main function when we created the dummy frame, the dummy frame will
1406 point inside the main function. */
1407 if (this_frame->level >= 0
1408 && get_frame_type (this_frame) != DUMMY_FRAME
1409 && !backtrace_past_main
1410 && inside_main_func (this_frame))
1411 /* Don't unwind past main(). Note, this is done _before_ the
1412 frame has been marked as previously unwound. That way if the
1413 user later decides to enable unwinds past main(), that will
1414 automatically happen. */
1416 frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside main func");
1420 /* If the user's backtrace limit has been exceeded, stop. We must
1421 add two to the current level; one of those accounts for backtrace_limit
1422 being 1-based and the level being 0-based, and the other accounts for
1423 the level of the new frame instead of the level of the current
1425 if (this_frame->level + 2 > backtrace_limit)
1427 frame_debug_got_null_frame (gdb_stdlog, this_frame,
1428 "backtrace limit exceeded");
1432 /* If we're already inside the entry function for the main objfile,
1433 then it isn't valid. Don't apply this test to a dummy frame -
1434 dummy frame PCs typically land in the entry func. Don't apply
1435 this test to the sentinel frame. Sentinel frames should always
1436 be allowed to unwind. */
1437 /* NOTE: cagney/2003-07-07: Fixed a bug in inside_main_func() -
1438 wasn't checking for "main" in the minimal symbols. With that
1439 fixed asm-source tests now stop in "main" instead of halting the
1440 backtrace in weird and wonderful ways somewhere inside the entry
1441 file. Suspect that tests for inside the entry file/func were
1442 added to work around that (now fixed) case. */
1443 /* NOTE: cagney/2003-07-15: danielj (if I'm reading it right)
1444 suggested having the inside_entry_func test use the
1445 inside_main_func() msymbol trick (along with entry_point_address()
1446 I guess) to determine the address range of the start function.
1447 That should provide a far better stopper than the current
1449 /* NOTE: tausq/2004-10-09: this is needed if, for example, the compiler
1450 applied tail-call optimizations to main so that a function called
1451 from main returns directly to the caller of main. Since we don't
1452 stop at main, we should at least stop at the entry point of the
1454 if (!backtrace_past_entry
1455 && get_frame_type (this_frame) != DUMMY_FRAME && this_frame->level >= 0
1456 && inside_entry_func (this_frame))
1458 frame_debug_got_null_frame (gdb_stdlog, this_frame, "inside entry func");
1462 /* Assume that the only way to get a zero PC is through something
1463 like a SIGSEGV or a dummy frame, and hence that NORMAL frames
1464 will never unwind a zero PC. */
1465 if (this_frame->level > 0
1466 && get_frame_type (this_frame) == NORMAL_FRAME
1467 && get_frame_type (get_next_frame (this_frame)) == NORMAL_FRAME
1468 && get_frame_pc (this_frame) == 0)
1470 frame_debug_got_null_frame (gdb_stdlog, this_frame, "zero PC");
1474 return get_prev_frame_1 (this_frame);
1478 get_frame_pc (struct frame_info *frame)
1480 gdb_assert (frame->next != NULL);
1481 return frame_pc_unwind (frame->next);
1484 /* Return an address that falls within NEXT_FRAME's caller's code
1485 block, assuming that the caller is a THIS_TYPE frame. */
1488 frame_unwind_address_in_block (struct frame_info *next_frame,
1489 enum frame_type this_type)
1491 /* A draft address. */
1492 CORE_ADDR pc = frame_pc_unwind (next_frame);
1494 /* If NEXT_FRAME was called by a signal frame or dummy frame, then
1495 we shold not adjust the unwound PC. These frames may not call
1496 their next frame in the normal way; the operating system or GDB
1497 may have pushed their resume address manually onto the stack, so
1498 it may be the very first instruction. Even if the resume address
1499 was not manually pushed, they expect to be returned to. */
1500 if (this_type != NORMAL_FRAME)
1503 /* If THIS frame is not inner most (i.e., NEXT isn't the sentinel),
1504 and NEXT is `normal' (i.e., not a sigtramp, dummy, ....) THIS
1505 frame's PC ends up pointing at the instruction fallowing the
1506 "call". Adjust that PC value so that it falls on the call
1507 instruction (which, hopefully, falls within THIS frame's code
1508 block). So far it's proved to be a very good approximation. See
1509 get_frame_type() for why ->type can't be used. */
1510 if (next_frame->level >= 0
1511 && get_frame_type (next_frame) == NORMAL_FRAME)
1517 get_frame_address_in_block (struct frame_info *this_frame)
1519 return frame_unwind_address_in_block (this_frame->next,
1520 get_frame_type (this_frame));
1524 pc_notcurrent (struct frame_info *frame)
1526 /* If FRAME is not the innermost frame, that normally means that
1527 FRAME->pc points at the return instruction (which is *after* the
1528 call instruction), and we want to get the line containing the
1529 call (because the call is where the user thinks the program is).
1530 However, if the next frame is either a SIGTRAMP_FRAME or a
1531 DUMMY_FRAME, then the next frame will contain a saved interrupt
1532 PC and such a PC indicates the current (rather than next)
1533 instruction/line, consequently, for such cases, want to get the
1534 line containing fi->pc. */
1535 struct frame_info *next = get_next_frame (frame);
1536 int notcurrent = (next != NULL && get_frame_type (next) == NORMAL_FRAME);
1541 find_frame_sal (struct frame_info *frame, struct symtab_and_line *sal)
1543 (*sal) = find_pc_line (get_frame_pc (frame), pc_notcurrent (frame));
1546 /* Per "frame.h", return the ``address'' of the frame. Code should
1547 really be using get_frame_id(). */
1549 get_frame_base (struct frame_info *fi)
1551 return get_frame_id (fi).stack_addr;
1554 /* High-level offsets into the frame. Used by the debug info. */
1557 get_frame_base_address (struct frame_info *fi)
1559 if (get_frame_type (fi) != NORMAL_FRAME)
1561 if (fi->base == NULL)
1562 fi->base = frame_base_find_by_frame (fi->next);
1563 /* Sneaky: If the low-level unwind and high-level base code share a
1564 common unwinder, let them share the prologue cache. */
1565 if (fi->base->unwind == fi->unwind)
1566 return fi->base->this_base (fi->next, &fi->prologue_cache);
1567 return fi->base->this_base (fi->next, &fi->base_cache);
1571 get_frame_locals_address (struct frame_info *fi)
1574 if (get_frame_type (fi) != NORMAL_FRAME)
1576 /* If there isn't a frame address method, find it. */
1577 if (fi->base == NULL)
1578 fi->base = frame_base_find_by_frame (fi->next);
1579 /* Sneaky: If the low-level unwind and high-level base code share a
1580 common unwinder, let them share the prologue cache. */
1581 if (fi->base->unwind == fi->unwind)
1582 cache = &fi->prologue_cache;
1584 cache = &fi->base_cache;
1585 return fi->base->this_locals (fi->next, cache);
1589 get_frame_args_address (struct frame_info *fi)
1592 if (get_frame_type (fi) != NORMAL_FRAME)
1594 /* If there isn't a frame address method, find it. */
1595 if (fi->base == NULL)
1596 fi->base = frame_base_find_by_frame (fi->next);
1597 /* Sneaky: If the low-level unwind and high-level base code share a
1598 common unwinder, let them share the prologue cache. */
1599 if (fi->base->unwind == fi->unwind)
1600 cache = &fi->prologue_cache;
1602 cache = &fi->base_cache;
1603 return fi->base->this_args (fi->next, cache);
1606 /* Level of the selected frame: 0 for innermost, 1 for its caller, ...
1607 or -1 for a NULL frame. */
1610 frame_relative_level (struct frame_info *fi)
1619 get_frame_type (struct frame_info *frame)
1621 if (frame->unwind == NULL)
1622 /* Initialize the frame's unwinder because that's what
1623 provides the frame's type. */
1624 frame->unwind = frame_unwind_find_by_frame (frame->next,
1625 &frame->prologue_cache);
1626 return frame->unwind->type;
1630 deprecated_update_frame_pc_hack (struct frame_info *frame, CORE_ADDR pc)
1633 fprintf_unfiltered (gdb_stdlog,
1634 "{ deprecated_update_frame_pc_hack (frame=%d,pc=0x%s) }\n",
1635 frame->level, paddr_nz (pc));
1636 /* NOTE: cagney/2003-03-11: Some architectures (e.g., Arm) are
1637 maintaining a locally allocated frame object. Since such frames
1638 are not in the frame chain, it isn't possible to assume that the
1639 frame has a next. Sigh. */
1640 if (frame->next != NULL)
1642 /* While we're at it, update this frame's cached PC value, found
1643 in the next frame. Oh for the day when "struct frame_info"
1644 is opaque and this hack on hack can just go away. */
1645 frame->next->prev_pc.value = pc;
1646 frame->next->prev_pc.p = 1;
1651 deprecated_update_frame_base_hack (struct frame_info *frame, CORE_ADDR base)
1654 fprintf_unfiltered (gdb_stdlog,
1655 "{ deprecated_update_frame_base_hack (frame=%d,base=0x%s) }\n",
1656 frame->level, paddr_nz (base));
1657 /* See comment in "frame.h". */
1658 frame->this_id.value.stack_addr = base;
1661 /* Memory access methods. */
1664 get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
1665 gdb_byte *buf, int len)
1667 read_memory (addr, buf, len);
1671 get_frame_memory_signed (struct frame_info *this_frame, CORE_ADDR addr,
1674 return read_memory_integer (addr, len);
1678 get_frame_memory_unsigned (struct frame_info *this_frame, CORE_ADDR addr,
1681 return read_memory_unsigned_integer (addr, len);
1685 safe_frame_unwind_memory (struct frame_info *this_frame,
1686 CORE_ADDR addr, gdb_byte *buf, int len)
1688 /* NOTE: read_memory_nobpt returns zero on success! */
1689 return !read_memory_nobpt (addr, buf, len);
1692 /* Architecture method. */
1695 get_frame_arch (struct frame_info *this_frame)
1697 return current_gdbarch;
1700 /* Stack pointer methods. */
1703 get_frame_sp (struct frame_info *this_frame)
1705 return frame_sp_unwind (this_frame->next);
1709 frame_sp_unwind (struct frame_info *next_frame)
1711 /* Normality - an architecture that provides a way of obtaining any
1712 frame inner-most address. */
1713 if (gdbarch_unwind_sp_p (current_gdbarch))
1714 return gdbarch_unwind_sp (current_gdbarch, next_frame);
1715 /* Now things are really are grim. Hope that the value returned by
1716 the SP_REGNUM register is meaningful. */
1720 frame_unwind_unsigned_register (next_frame, SP_REGNUM, &sp);
1723 internal_error (__FILE__, __LINE__, _("Missing unwind SP method"));
1726 /* Return the reason why we can't unwind past FRAME. */
1728 enum unwind_stop_reason
1729 get_frame_unwind_stop_reason (struct frame_info *frame)
1731 /* If we haven't tried to unwind past this point yet, then assume
1732 that unwinding would succeed. */
1733 if (frame->prev_p == 0)
1734 return UNWIND_NO_REASON;
1736 /* Otherwise, we set a reason when we succeeded (or failed) to
1738 return frame->stop_reason;
1741 /* Return a string explaining REASON. */
1744 frame_stop_reason_string (enum unwind_stop_reason reason)
1748 case UNWIND_NULL_ID:
1749 return _("unwinder did not report frame ID");
1751 case UNWIND_INNER_ID:
1752 return _("previous frame inner to this frame (corrupt stack?)");
1754 case UNWIND_SAME_ID:
1755 return _("previous frame identical to this frame (corrupt stack?)");
1757 case UNWIND_NO_SAVED_PC:
1758 return _("frame did not save the PC");
1760 case UNWIND_NO_REASON:
1761 case UNWIND_FIRST_ERROR:
1763 internal_error (__FILE__, __LINE__,
1764 "Invalid frame stop reason");
1768 extern initialize_file_ftype _initialize_frame; /* -Wmissing-prototypes */
1770 static struct cmd_list_element *set_backtrace_cmdlist;
1771 static struct cmd_list_element *show_backtrace_cmdlist;
1774 set_backtrace_cmd (char *args, int from_tty)
1776 help_list (set_backtrace_cmdlist, "set backtrace ", -1, gdb_stdout);
1780 show_backtrace_cmd (char *args, int from_tty)
1782 cmd_show_list (show_backtrace_cmdlist, from_tty, "");
1786 _initialize_frame (void)
1788 obstack_init (&frame_cache_obstack);
1790 observer_attach_target_changed (frame_observer_target_changed);
1792 add_prefix_cmd ("backtrace", class_maintenance, set_backtrace_cmd, _("\
1793 Set backtrace specific variables.\n\
1794 Configure backtrace variables such as the backtrace limit"),
1795 &set_backtrace_cmdlist, "set backtrace ",
1796 0/*allow-unknown*/, &setlist);
1797 add_prefix_cmd ("backtrace", class_maintenance, show_backtrace_cmd, _("\
1798 Show backtrace specific variables\n\
1799 Show backtrace variables such as the backtrace limit"),
1800 &show_backtrace_cmdlist, "show backtrace ",
1801 0/*allow-unknown*/, &showlist);
1803 add_setshow_boolean_cmd ("past-main", class_obscure,
1804 &backtrace_past_main, _("\
1805 Set whether backtraces should continue past \"main\"."), _("\
1806 Show whether backtraces should continue past \"main\"."), _("\
1807 Normally the caller of \"main\" is not of interest, so GDB will terminate\n\
1808 the backtrace at \"main\". Set this variable if you need to see the rest\n\
1809 of the stack trace."),
1811 show_backtrace_past_main,
1812 &set_backtrace_cmdlist,
1813 &show_backtrace_cmdlist);
1815 add_setshow_boolean_cmd ("past-entry", class_obscure,
1816 &backtrace_past_entry, _("\
1817 Set whether backtraces should continue past the entry point of a program."),
1819 Show whether backtraces should continue past the entry point of a program."),
1821 Normally there are no callers beyond the entry point of a program, so GDB\n\
1822 will terminate the backtrace there. Set this variable if you need to see \n\
1823 the rest of the stack trace."),
1825 show_backtrace_past_entry,
1826 &set_backtrace_cmdlist,
1827 &show_backtrace_cmdlist);
1829 add_setshow_integer_cmd ("limit", class_obscure,
1830 &backtrace_limit, _("\
1831 Set an upper bound on the number of backtrace levels."), _("\
1832 Show the upper bound on the number of backtrace levels."), _("\
1833 No more than the specified number of frames can be displayed or examined.\n\
1834 Zero is unlimited."),
1836 show_backtrace_limit,
1837 &set_backtrace_cmdlist,
1838 &show_backtrace_cmdlist);
1840 /* Debug this files internals. */
1841 add_setshow_zinteger_cmd ("frame", class_maintenance, &frame_debug, _("\
1842 Set frame debugging."), _("\
1843 Show frame debugging."), _("\
1844 When non-zero, frame specific internal debugging is enabled."),
1847 &setdebuglist, &showdebuglist);