1 /* Get info from stack frames; convert between frames, blocks,
2 functions and pc values.
4 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994,
5 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 Free Software
8 This file is part of GDB.
10 This program is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or
13 (at your option) any later version.
15 This program is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 59 Temple Place - Suite 330,
23 Boston, MA 02111-1307, USA. */
32 #include "value.h" /* for read_register */
33 #include "target.h" /* for target_has_stack */
34 #include "inferior.h" /* for read_pc */
37 #include "gdb_assert.h"
39 /* Prototypes for exported functions. */
41 static void generic_call_dummy_register_unwind (struct frame_info
*frame
,
49 static void frame_saved_regs_register_unwind (struct frame_info
*frame
,
59 void _initialize_blockframe (void);
61 /* A default FRAME_CHAIN_VALID, in the form that is suitable for most
62 targets. If FRAME_CHAIN_VALID returns zero it means that the given
63 frame is the outermost one and has no caller. */
66 file_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
69 && !inside_entry_file (FRAME_SAVED_PC (thisframe
)));
72 /* Use the alternate method of avoiding running up off the end of the
73 frame chain or following frames back into the startup code. See
74 the comments in objfiles.h. */
77 func_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
80 && !inside_main_func ((thisframe
)->pc
)
81 && !inside_entry_func ((thisframe
)->pc
));
84 /* A very simple method of determining a valid frame */
87 nonnull_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
89 return ((chain
) != 0);
92 /* Is ADDR inside the startup file? Note that if your machine
93 has a way to detect the bottom of the stack, there is no need
94 to call this function from FRAME_CHAIN_VALID; the reason for
95 doing so is that some machines have no way of detecting bottom
98 A PC of zero is always considered to be the bottom of the stack. */
101 inside_entry_file (CORE_ADDR addr
)
105 if (symfile_objfile
== 0)
107 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
109 /* Do not stop backtracing if the pc is in the call dummy
110 at the entry point. */
111 /* FIXME: Won't always work with zeros for the last two arguments */
112 if (PC_IN_CALL_DUMMY (addr
, 0, 0))
115 return (addr
>= symfile_objfile
->ei
.entry_file_lowpc
&&
116 addr
< symfile_objfile
->ei
.entry_file_highpc
);
119 /* Test a specified PC value to see if it is in the range of addresses
120 that correspond to the main() function. See comments above for why
121 we might want to do this.
123 Typically called from FRAME_CHAIN_VALID.
125 A PC of zero is always considered to be the bottom of the stack. */
128 inside_main_func (CORE_ADDR pc
)
132 if (symfile_objfile
== 0)
135 /* If the addr range is not set up at symbol reading time, set it up now.
136 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
137 it is unable to set it up and symbol reading time. */
139 if (symfile_objfile
->ei
.main_func_lowpc
== INVALID_ENTRY_LOWPC
&&
140 symfile_objfile
->ei
.main_func_highpc
== INVALID_ENTRY_HIGHPC
)
142 struct symbol
*mainsym
;
144 mainsym
= lookup_symbol (main_name (), NULL
, VAR_NAMESPACE
, NULL
, NULL
);
145 if (mainsym
&& SYMBOL_CLASS (mainsym
) == LOC_BLOCK
)
147 symfile_objfile
->ei
.main_func_lowpc
=
148 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym
));
149 symfile_objfile
->ei
.main_func_highpc
=
150 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym
));
153 return (symfile_objfile
->ei
.main_func_lowpc
<= pc
&&
154 symfile_objfile
->ei
.main_func_highpc
> pc
);
157 /* Test a specified PC value to see if it is in the range of addresses
158 that correspond to the process entry point function. See comments
159 in objfiles.h for why we might want to do this.
161 Typically called from FRAME_CHAIN_VALID.
163 A PC of zero is always considered to be the bottom of the stack. */
166 inside_entry_func (CORE_ADDR pc
)
170 if (symfile_objfile
== 0)
172 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
174 /* Do not stop backtracing if the pc is in the call dummy
175 at the entry point. */
176 /* FIXME: Won't always work with zeros for the last two arguments */
177 if (PC_IN_CALL_DUMMY (pc
, 0, 0))
180 return (symfile_objfile
->ei
.entry_func_lowpc
<= pc
&&
181 symfile_objfile
->ei
.entry_func_highpc
> pc
);
184 /* Info about the innermost stack frame (contents of FP register) */
186 static struct frame_info
*current_frame
;
188 /* Cache for frame addresses already read by gdb. Valid only while
189 inferior is stopped. Control variables for the frame cache should
190 be local to this module. */
192 static struct obstack frame_cache_obstack
;
195 frame_obstack_alloc (unsigned long size
)
197 return obstack_alloc (&frame_cache_obstack
, size
);
201 frame_saved_regs_zalloc (struct frame_info
*fi
)
203 fi
->saved_regs
= (CORE_ADDR
*)
204 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
205 memset (fi
->saved_regs
, 0, SIZEOF_FRAME_SAVED_REGS
);
209 /* Return the innermost (currently executing) stack frame. */
212 get_current_frame (void)
214 if (current_frame
== NULL
)
216 if (target_has_stack
)
217 current_frame
= create_new_frame (read_fp (), read_pc ());
221 return current_frame
;
225 set_current_frame (struct frame_info
*frame
)
227 current_frame
= frame
;
231 /* Using the PC, select a mechanism for unwinding a frame returning
232 the previous frame. The register unwind function should, on
233 demand, initialize the ->context object. */
236 set_unwind_by_pc (CORE_ADDR pc
, CORE_ADDR fp
,
237 frame_register_unwind_ftype
**unwind
)
239 if (!USE_GENERIC_DUMMY_FRAMES
)
240 /* Still need to set this to something. The ``info frame'' code
241 calls this function to find out where the saved registers are.
242 Hopefully this is robust enough to stop any core dumps and
243 return vaguely correct values.. */
244 *unwind
= frame_saved_regs_register_unwind
;
245 else if (PC_IN_CALL_DUMMY (pc
, fp
, fp
))
246 *unwind
= generic_call_dummy_register_unwind
;
248 *unwind
= frame_saved_regs_register_unwind
;
251 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
252 Always returns a non-NULL value. */
255 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
257 struct frame_info
*fi
;
260 fi
= (struct frame_info
*)
261 obstack_alloc (&frame_cache_obstack
,
262 sizeof (struct frame_info
));
264 /* Zero all fields by default. */
265 memset (fi
, 0, sizeof (struct frame_info
));
269 find_pc_partial_function (pc
, &name
, (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
270 fi
->signal_handler_caller
= PC_IN_SIGTRAMP (fi
->pc
, name
);
272 if (INIT_EXTRA_FRAME_INFO_P ())
273 INIT_EXTRA_FRAME_INFO (0, fi
);
275 /* Select/initialize an unwind function. */
276 set_unwind_by_pc (fi
->pc
, fi
->frame
, &fi
->register_unwind
);
281 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
285 get_next_frame (struct frame_info
*frame
)
290 /* Flush the entire frame cache. */
293 flush_cached_frames (void)
295 /* Since we can't really be sure what the first object allocated was */
296 obstack_free (&frame_cache_obstack
, 0);
297 obstack_init (&frame_cache_obstack
);
299 current_frame
= NULL
; /* Invalidate cache */
301 annotate_frames_invalid ();
304 /* Flush the frame cache, and start a new one if necessary. */
307 reinit_frame_cache (void)
309 flush_cached_frames ();
311 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
312 if (PIDGET (inferior_ptid
) != 0)
314 select_frame (get_current_frame ());
318 /* Return nonzero if the function for this frame lacks a prologue. Many
319 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
323 frameless_look_for_prologue (struct frame_info
*frame
)
325 CORE_ADDR func_start
, after_prologue
;
327 func_start
= get_pc_function_start (frame
->pc
);
330 func_start
+= FUNCTION_START_OFFSET
;
331 /* This is faster, since only care whether there *is* a
332 prologue, not how long it is. */
333 return PROLOGUE_FRAMELESS_P (func_start
);
335 else if (frame
->pc
== 0)
336 /* A frame with a zero PC is usually created by dereferencing a
337 NULL function pointer, normally causing an immediate core dump
338 of the inferior. Mark function as frameless, as the inferior
339 has no chance of setting up a stack frame. */
342 /* If we can't find the start of the function, we don't really
343 know whether the function is frameless, but we should be able
344 to get a reasonable (i.e. best we can do under the
345 circumstances) backtrace by saying that it isn't. */
349 /* Return a structure containing various interesting information
350 about the frame that called NEXT_FRAME. Returns NULL
351 if there is no such frame. */
354 get_prev_frame (struct frame_info
*next_frame
)
356 CORE_ADDR address
= 0;
357 struct frame_info
*prev
;
361 /* If the requested entry is in the cache, return it.
362 Otherwise, figure out what the address should be for the entry
363 we're about to add to the cache. */
368 /* This screws value_of_variable, which just wants a nice clean
369 NULL return from block_innermost_frame if there are no frames.
370 I don't think I've ever seen this message happen otherwise.
371 And returning NULL here is a perfectly legitimate thing to do. */
374 error ("You haven't set up a process's stack to examine.");
378 return current_frame
;
381 /* If we have the prev one, return it */
382 if (next_frame
->prev
)
383 return next_frame
->prev
;
385 /* On some machines it is possible to call a function without
386 setting up a stack frame for it. On these machines, we
387 define this macro to take two args; a frameinfo pointer
388 identifying a frame and a variable to set or clear if it is
389 or isn't leafless. */
391 /* Still don't want to worry about this except on the innermost
392 frame. This macro will set FROMLEAF if NEXT_FRAME is a
393 frameless function invocation. */
394 if (!(next_frame
->next
))
396 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
398 address
= FRAME_FP (next_frame
);
403 /* Two macros defined in tm.h specify the machine-dependent
404 actions to be performed here.
405 First, get the frame's chain-pointer.
406 If that is zero, the frame is the outermost frame or a leaf
407 called by the outermost frame. This means that if start
408 calls main without a frame, we'll return 0 (which is fine
411 Nope; there's a problem. This also returns when the current
412 routine is a leaf of main. This is unacceptable. We move
413 this to after the ffi test; I'd rather have backtraces from
414 start go curfluy than have an abort called from main not show
416 address
= FRAME_CHAIN (next_frame
);
417 if (!FRAME_CHAIN_VALID (address
, next_frame
))
423 prev
= (struct frame_info
*)
424 obstack_alloc (&frame_cache_obstack
,
425 sizeof (struct frame_info
));
427 /* Zero all fields by default. */
428 memset (prev
, 0, sizeof (struct frame_info
));
431 next_frame
->prev
= prev
;
432 prev
->next
= next_frame
;
433 prev
->frame
= address
;
434 prev
->level
= next_frame
->level
+ 1;
436 /* This change should not be needed, FIXME! We should
437 determine whether any targets *need* INIT_FRAME_PC to happen
438 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
439 express what goes on here.
441 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
442 (where the PC is already set up) and here (where it isn't).
443 INIT_FRAME_PC is only called from here, always after
444 INIT_EXTRA_FRAME_INFO.
446 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
447 value (which hasn't been set yet). Some other machines appear to
448 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
450 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
451 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
453 Assuming that some machines need INIT_FRAME_PC after
454 INIT_EXTRA_FRAME_INFO, one possible scheme:
456 SETUP_INNERMOST_FRAME()
457 Default version is just create_new_frame (read_fp ()),
458 read_pc ()). Machines with extra frame info would do that (or the
459 local equivalent) and then set the extra fields.
460 SETUP_ARBITRARY_FRAME(argc, argv)
461 Only change here is that create_new_frame would no longer init extra
462 frame info; SETUP_ARBITRARY_FRAME would have to do that.
463 INIT_PREV_FRAME(fromleaf, prev)
464 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
465 also return a flag saying whether to keep the new frame, or
466 whether to discard it, because on some machines (e.g. mips) it
467 is really awkward to have FRAME_CHAIN_VALID called *before*
468 INIT_EXTRA_FRAME_INFO (there is no good way to get information
469 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
470 std_frame_pc(fromleaf, prev)
471 This is the default setting for INIT_PREV_FRAME. It just does what
472 the default INIT_FRAME_PC does. Some machines will call it from
473 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
474 Some machines won't use it.
475 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
477 INIT_FRAME_PC_FIRST (fromleaf
, prev
);
479 if (INIT_EXTRA_FRAME_INFO_P ())
480 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
482 /* This entry is in the frame queue now, which is good since
483 FRAME_SAVED_PC may use that queue to figure out its value
484 (see tm-sparc.h). We want the pc saved in the inferior frame. */
485 INIT_FRAME_PC (fromleaf
, prev
);
487 /* If ->frame and ->pc are unchanged, we are in the process of getting
488 ourselves into an infinite backtrace. Some architectures check this
489 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
490 this can't be an architecture-independent check. */
491 if (next_frame
!= NULL
)
493 if (prev
->frame
== next_frame
->frame
494 && prev
->pc
== next_frame
->pc
)
496 next_frame
->prev
= NULL
;
497 obstack_free (&frame_cache_obstack
, prev
);
502 /* Initialize the code used to unwind the frame PREV based on the PC
503 (and probably other architectural information). The PC lets you
504 check things like the debug info at that point (dwarf2cfi?) and
505 use that to decide how the frame should be unwound. */
506 set_unwind_by_pc (prev
->pc
, prev
->frame
, &prev
->register_unwind
);
508 find_pc_partial_function (prev
->pc
, &name
,
509 (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
510 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
511 prev
->signal_handler_caller
= 1;
517 get_frame_pc (struct frame_info
*frame
)
523 #ifdef FRAME_FIND_SAVED_REGS
524 /* XXX - deprecated. This is a compatibility function for targets
525 that do not yet implement FRAME_INIT_SAVED_REGS. */
526 /* Find the addresses in which registers are saved in FRAME. */
529 get_frame_saved_regs (struct frame_info
*frame
,
530 struct frame_saved_regs
*saved_regs_addr
)
532 if (frame
->saved_regs
== NULL
)
534 frame
->saved_regs
= (CORE_ADDR
*)
535 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
537 if (saved_regs_addr
== NULL
)
539 struct frame_saved_regs saved_regs
;
540 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
541 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
545 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
546 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
551 /* Return the innermost lexical block in execution
552 in a specified stack frame. The frame address is assumed valid.
554 If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
555 address we used to choose the block. We use this to find a source
556 line, to decide which macro definitions are in scope.
558 The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
559 PC, and may not really be a valid PC at all. For example, in the
560 caller of a function declared to never return, the code at the
561 return address will never be reached, so the call instruction may
562 be the very last instruction in the block. So the address we use
563 to choose the block is actually one byte before the return address
564 --- hopefully pointing us at the call instruction, or its delay
568 get_frame_block (struct frame_info
*frame
, CORE_ADDR
*addr_in_block
)
573 if (frame
->next
!= 0 && frame
->next
->signal_handler_caller
== 0)
574 /* We are not in the innermost frame and we were not interrupted
575 by a signal. We need to subtract one to get the correct block,
576 in case the call instruction was the last instruction of the block.
577 If there are any machines on which the saved pc does not point to
578 after the call insn, we probably want to make frame->pc point after
579 the call insn anyway. */
585 return block_for_pc (pc
);
589 get_current_block (CORE_ADDR
*addr_in_block
)
591 CORE_ADDR pc
= read_pc ();
596 return block_for_pc (pc
);
600 get_pc_function_start (CORE_ADDR pc
)
602 register struct block
*bl
;
603 register struct symbol
*symbol
;
604 register struct minimal_symbol
*msymbol
;
607 if ((bl
= block_for_pc (pc
)) != NULL
&&
608 (symbol
= block_function (bl
)) != NULL
)
610 bl
= SYMBOL_BLOCK_VALUE (symbol
);
611 fstart
= BLOCK_START (bl
);
613 else if ((msymbol
= lookup_minimal_symbol_by_pc (pc
)) != NULL
)
615 fstart
= SYMBOL_VALUE_ADDRESS (msymbol
);
624 /* Return the symbol for the function executing in frame FRAME. */
627 get_frame_function (struct frame_info
*frame
)
629 register struct block
*bl
= get_frame_block (frame
, 0);
632 return block_function (bl
);
636 /* Return the blockvector immediately containing the innermost lexical block
637 containing the specified pc value and section, or 0 if there is none.
638 PINDEX is a pointer to the index value of the block. If PINDEX
639 is NULL, we don't pass this information back to the caller. */
642 blockvector_for_pc_sect (register CORE_ADDR pc
, struct sec
*section
,
643 int *pindex
, struct symtab
*symtab
)
645 register struct block
*b
;
646 register int bot
, top
, half
;
647 struct blockvector
*bl
;
649 if (symtab
== 0) /* if no symtab specified by caller */
651 /* First search all symtabs for one whose file contains our pc */
652 if ((symtab
= find_pc_sect_symtab (pc
, section
)) == 0)
656 bl
= BLOCKVECTOR (symtab
);
657 b
= BLOCKVECTOR_BLOCK (bl
, 0);
659 /* Then search that symtab for the smallest block that wins. */
660 /* Use binary search to find the last block that starts before PC. */
663 top
= BLOCKVECTOR_NBLOCKS (bl
);
665 while (top
- bot
> 1)
667 half
= (top
- bot
+ 1) >> 1;
668 b
= BLOCKVECTOR_BLOCK (bl
, bot
+ half
);
669 if (BLOCK_START (b
) <= pc
)
675 /* Now search backward for a block that ends after PC. */
679 b
= BLOCKVECTOR_BLOCK (bl
, bot
);
680 if (BLOCK_END (b
) > pc
)
691 /* Return the blockvector immediately containing the innermost lexical block
692 containing the specified pc value, or 0 if there is none.
693 Backward compatibility, no section. */
696 blockvector_for_pc (register CORE_ADDR pc
, int *pindex
)
698 return blockvector_for_pc_sect (pc
, find_pc_mapped_section (pc
),
702 /* Return the innermost lexical block containing the specified pc value
703 in the specified section, or 0 if there is none. */
706 block_for_pc_sect (register CORE_ADDR pc
, struct sec
*section
)
708 register struct blockvector
*bl
;
711 bl
= blockvector_for_pc_sect (pc
, section
, &index
, NULL
);
713 return BLOCKVECTOR_BLOCK (bl
, index
);
717 /* Return the innermost lexical block containing the specified pc value,
718 or 0 if there is none. Backward compatibility, no section. */
721 block_for_pc (register CORE_ADDR pc
)
723 return block_for_pc_sect (pc
, find_pc_mapped_section (pc
));
726 /* Return the function containing pc value PC in section SECTION.
727 Returns 0 if function is not known. */
730 find_pc_sect_function (CORE_ADDR pc
, struct sec
*section
)
732 register struct block
*b
= block_for_pc_sect (pc
, section
);
735 return block_function (b
);
738 /* Return the function containing pc value PC.
739 Returns 0 if function is not known. Backward compatibility, no section */
742 find_pc_function (CORE_ADDR pc
)
744 return find_pc_sect_function (pc
, find_pc_mapped_section (pc
));
747 /* These variables are used to cache the most recent result
748 * of find_pc_partial_function. */
750 static CORE_ADDR cache_pc_function_low
= 0;
751 static CORE_ADDR cache_pc_function_high
= 0;
752 static char *cache_pc_function_name
= 0;
753 static struct sec
*cache_pc_function_section
= NULL
;
755 /* Clear cache, e.g. when symbol table is discarded. */
758 clear_pc_function_cache (void)
760 cache_pc_function_low
= 0;
761 cache_pc_function_high
= 0;
762 cache_pc_function_name
= (char *) 0;
763 cache_pc_function_section
= NULL
;
766 /* Finds the "function" (text symbol) that is smaller than PC but
767 greatest of all of the potential text symbols in SECTION. Sets
768 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
769 If ENDADDR is non-null, then set *ENDADDR to be the end of the
770 function (exclusive), but passing ENDADDR as non-null means that
771 the function might cause symbols to be read. This function either
772 succeeds or fails (not halfway succeeds). If it succeeds, it sets
773 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
774 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
778 find_pc_sect_partial_function (CORE_ADDR pc
, asection
*section
, char **name
,
779 CORE_ADDR
*address
, CORE_ADDR
*endaddr
)
781 struct partial_symtab
*pst
;
783 struct minimal_symbol
*msymbol
;
784 struct partial_symbol
*psb
;
785 struct obj_section
*osect
;
789 mapped_pc
= overlay_mapped_address (pc
, section
);
791 if (mapped_pc
>= cache_pc_function_low
&&
792 mapped_pc
< cache_pc_function_high
&&
793 section
== cache_pc_function_section
)
794 goto return_cached_value
;
796 /* If sigtramp is in the u area, it counts as a function (especially
797 important for step_1). */
798 #if defined SIGTRAMP_START
799 if (PC_IN_SIGTRAMP (mapped_pc
, (char *) NULL
))
801 cache_pc_function_low
= SIGTRAMP_START (mapped_pc
);
802 cache_pc_function_high
= SIGTRAMP_END (mapped_pc
);
803 cache_pc_function_name
= "<sigtramp>";
804 cache_pc_function_section
= section
;
805 goto return_cached_value
;
809 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
810 pst
= find_pc_sect_psymtab (mapped_pc
, section
);
813 /* Need to read the symbols to get a good value for the end address. */
814 if (endaddr
!= NULL
&& !pst
->readin
)
816 /* Need to get the terminal in case symbol-reading produces
818 target_terminal_ours_for_output ();
819 PSYMTAB_TO_SYMTAB (pst
);
824 /* Checking whether the msymbol has a larger value is for the
825 "pathological" case mentioned in print_frame_info. */
826 f
= find_pc_sect_function (mapped_pc
, section
);
829 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
830 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
832 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
833 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
834 cache_pc_function_name
= SYMBOL_NAME (f
);
835 cache_pc_function_section
= section
;
836 goto return_cached_value
;
841 /* Now that static symbols go in the minimal symbol table, perhaps
842 we could just ignore the partial symbols. But at least for now
843 we use the partial or minimal symbol, whichever is larger. */
844 psb
= find_pc_sect_psymbol (pst
, mapped_pc
, section
);
847 && (msymbol
== NULL
||
848 (SYMBOL_VALUE_ADDRESS (psb
)
849 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
851 /* This case isn't being cached currently. */
853 *address
= SYMBOL_VALUE_ADDRESS (psb
);
855 *name
= SYMBOL_NAME (psb
);
856 /* endaddr non-NULL can't happen here. */
862 /* Not in the normal symbol tables, see if the pc is in a known section.
863 If it's not, then give up. This ensures that anything beyond the end
864 of the text seg doesn't appear to be part of the last function in the
867 osect
= find_pc_sect_section (mapped_pc
, section
);
872 /* Must be in the minimal symbol table. */
875 /* No available symbol. */
885 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
886 cache_pc_function_name
= SYMBOL_NAME (msymbol
);
887 cache_pc_function_section
= section
;
889 /* Use the lesser of the next minimal symbol in the same section, or
890 the end of the section, as the end of the function. */
892 /* Step over other symbols at this same address, and symbols in
893 other sections, to find the next symbol in this section with
894 a different address. */
896 for (i
= 1; SYMBOL_NAME (msymbol
+ i
) != NULL
; i
++)
898 if (SYMBOL_VALUE_ADDRESS (msymbol
+ i
) != SYMBOL_VALUE_ADDRESS (msymbol
)
899 && SYMBOL_BFD_SECTION (msymbol
+ i
) == SYMBOL_BFD_SECTION (msymbol
))
903 if (SYMBOL_NAME (msymbol
+ i
) != NULL
904 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
) < osect
->endaddr
)
905 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
907 /* We got the start address from the last msymbol in the objfile.
908 So the end address is the end of the section. */
909 cache_pc_function_high
= osect
->endaddr
;
915 if (pc_in_unmapped_range (pc
, section
))
916 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
918 *address
= cache_pc_function_low
;
922 *name
= cache_pc_function_name
;
926 if (pc_in_unmapped_range (pc
, section
))
928 /* Because the high address is actually beyond the end of
929 the function (and therefore possibly beyond the end of
930 the overlay), we must actually convert (high - 1)
931 and then add one to that. */
933 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
937 *endaddr
= cache_pc_function_high
;
943 /* Backward compatibility, no section argument */
946 find_pc_partial_function (CORE_ADDR pc
, char **name
, CORE_ADDR
*address
,
951 section
= find_pc_overlay (pc
);
952 return find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
);
955 /* Return the innermost stack frame executing inside of BLOCK,
956 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
959 block_innermost_frame (struct block
*block
)
961 struct frame_info
*frame
;
962 register CORE_ADDR start
;
963 register CORE_ADDR end
;
968 start
= BLOCK_START (block
);
969 end
= BLOCK_END (block
);
974 frame
= get_prev_frame (frame
);
977 if (frame
->pc
>= start
&& frame
->pc
< end
)
982 /* Return the full FRAME which corresponds to the given CORE_ADDR
983 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
986 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr
)
988 struct frame_info
*frame
= NULL
;
990 if (frame_addr
== (CORE_ADDR
) 0)
995 frame
= get_prev_frame (frame
);
998 if (FRAME_FP (frame
) == frame_addr
)
1003 #ifdef SIGCONTEXT_PC_OFFSET
1004 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
1007 sigtramp_saved_pc (struct frame_info
*frame
)
1009 CORE_ADDR sigcontext_addr
;
1011 int ptrbytes
= TARGET_PTR_BIT
/ TARGET_CHAR_BIT
;
1012 int sigcontext_offs
= (2 * TARGET_INT_BIT
) / TARGET_CHAR_BIT
;
1014 buf
= alloca (ptrbytes
);
1015 /* Get sigcontext address, it is the third parameter on the stack. */
1017 sigcontext_addr
= read_memory_integer (FRAME_ARGS_ADDRESS (frame
->next
)
1022 sigcontext_addr
= read_memory_integer (read_register (SP_REGNUM
)
1026 /* Don't cause a memory_error when accessing sigcontext in case the stack
1027 layout has changed or the stack is corrupt. */
1028 target_read_memory (sigcontext_addr
+ SIGCONTEXT_PC_OFFSET
, buf
, ptrbytes
);
1029 return extract_unsigned_integer (buf
, ptrbytes
);
1031 #endif /* SIGCONTEXT_PC_OFFSET */
1034 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
1035 below is for infrun.c, which may give the macro a pc without that
1038 extern CORE_ADDR text_end
;
1041 pc_in_call_dummy_before_text_end (CORE_ADDR pc
, CORE_ADDR sp
,
1042 CORE_ADDR frame_address
)
1044 return ((pc
) >= text_end
- CALL_DUMMY_LENGTH
1045 && (pc
) <= text_end
+ DECR_PC_AFTER_BREAK
);
1049 pc_in_call_dummy_after_text_end (CORE_ADDR pc
, CORE_ADDR sp
,
1050 CORE_ADDR frame_address
)
1052 return ((pc
) >= text_end
1053 && (pc
) <= text_end
+ CALL_DUMMY_LENGTH
+ DECR_PC_AFTER_BREAK
);
1056 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1057 top of the stack frame which we are checking, where "bottom" and
1058 "top" refer to some section of memory which contains the code for
1059 the call dummy. Calls to this macro assume that the contents of
1060 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1061 are the things to pass.
1063 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1064 have that meaning, but the 29k doesn't use ON_STACK. This could be
1065 fixed by generalizing this scheme, perhaps by passing in a frame
1066 and adding a few fields, at least on machines which need them for
1069 Something simpler, like checking for the stack segment, doesn't work,
1070 since various programs (threads implementations, gcc nested function
1071 stubs, etc) may either allocate stack frames in another segment, or
1072 allocate other kinds of code on the stack. */
1075 pc_in_call_dummy_on_stack (CORE_ADDR pc
, CORE_ADDR sp
, CORE_ADDR frame_address
)
1077 return (INNER_THAN ((sp
), (pc
))
1078 && (frame_address
!= 0)
1079 && INNER_THAN ((pc
), (frame_address
)));
1083 pc_in_call_dummy_at_entry_point (CORE_ADDR pc
, CORE_ADDR sp
,
1084 CORE_ADDR frame_address
)
1086 return ((pc
) >= CALL_DUMMY_ADDRESS ()
1087 && (pc
) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK
));
1092 * GENERIC DUMMY FRAMES
1094 * The following code serves to maintain the dummy stack frames for
1095 * inferior function calls (ie. when gdb calls into the inferior via
1096 * call_function_by_hand). This code saves the machine state before
1097 * the call in host memory, so we must maintain an independent stack
1098 * and keep it consistant etc. I am attempting to make this code
1099 * generic enough to be used by many targets.
1101 * The cheapest and most generic way to do CALL_DUMMY on a new target
1102 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1103 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1104 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1105 * being executed by the target. Also FRAME_CHAIN_VALID as
1106 * generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
1107 * generic_fix_call_dummy. */
1109 /* Dummy frame. This saves the processor state just prior to setting
1110 up the inferior function call. Older targets save the registers
1111 on the target stack (but that really slows down function calls). */
1115 struct dummy_frame
*next
;
1123 /* Address range of the call dummy code. Look for PC in the range
1124 [LO..HI) (after allowing for DECR_PC_AFTER_BREAK). */
1129 static struct dummy_frame
*dummy_frame_stack
= NULL
;
1131 /* Function: find_dummy_frame(pc, fp, sp)
1133 Search the stack of dummy frames for one matching the given PC, FP
1134 and SP. Unlike PC_IN_CALL_DUMMY, this function doesn't need to
1135 adjust for DECR_PC_AFTER_BREAK. This is because it is only legal
1136 to call this function after the PC has been adjusted. */
1139 generic_find_dummy_frame (CORE_ADDR pc
, CORE_ADDR fp
)
1141 struct dummy_frame
*dummyframe
;
1143 for (dummyframe
= dummy_frame_stack
; dummyframe
!= NULL
;
1144 dummyframe
= dummyframe
->next
)
1145 if ((pc
>= dummyframe
->call_lo
&& pc
< dummyframe
->call_hi
)
1146 && (fp
== dummyframe
->fp
1147 || fp
== dummyframe
->sp
1148 || fp
== dummyframe
->top
))
1149 /* The frame in question lies between the saved fp and sp, inclusive */
1150 return dummyframe
->registers
;
1155 /* Function: pc_in_call_dummy (pc, sp, fp)
1157 Return true if the PC falls in a dummy frame created by gdb for an
1158 inferior call. The code below which allows DECR_PC_AFTER_BREAK is
1159 for infrun.c, which may give the function a PC without that
1163 generic_pc_in_call_dummy (CORE_ADDR pc
, CORE_ADDR sp
, CORE_ADDR fp
)
1165 struct dummy_frame
*dummyframe
;
1166 for (dummyframe
= dummy_frame_stack
;
1168 dummyframe
= dummyframe
->next
)
1170 if ((pc
>= dummyframe
->call_lo
)
1171 && (pc
< dummyframe
->call_hi
+ DECR_PC_AFTER_BREAK
))
1177 /* Function: read_register_dummy
1178 Find a saved register from before GDB calls a function in the inferior */
1181 generic_read_register_dummy (CORE_ADDR pc
, CORE_ADDR fp
, int regno
)
1183 char *dummy_regs
= generic_find_dummy_frame (pc
, fp
);
1186 return extract_address (&dummy_regs
[REGISTER_BYTE (regno
)],
1187 REGISTER_RAW_SIZE (regno
));
1192 /* Save all the registers on the dummy frame stack. Most ports save the
1193 registers on the target stack. This results in lots of unnecessary memory
1194 references, which are slow when debugging via a serial line. Instead, we
1195 save all the registers internally, and never write them to the stack. The
1196 registers get restored when the called function returns to the entry point,
1197 where a breakpoint is laying in wait. */
1200 generic_push_dummy_frame (void)
1202 struct dummy_frame
*dummy_frame
;
1203 CORE_ADDR fp
= (get_current_frame ())->frame
;
1205 /* check to see if there are stale dummy frames,
1206 perhaps left over from when a longjump took us out of a
1207 function that was called by the debugger */
1209 dummy_frame
= dummy_frame_stack
;
1211 if (INNER_THAN (dummy_frame
->fp
, fp
)) /* stale -- destroy! */
1213 dummy_frame_stack
= dummy_frame
->next
;
1214 xfree (dummy_frame
->registers
);
1215 xfree (dummy_frame
);
1216 dummy_frame
= dummy_frame_stack
;
1219 dummy_frame
= dummy_frame
->next
;
1221 dummy_frame
= xmalloc (sizeof (struct dummy_frame
));
1222 dummy_frame
->registers
= xmalloc (REGISTER_BYTES
);
1224 dummy_frame
->pc
= read_pc ();
1225 dummy_frame
->sp
= read_sp ();
1226 dummy_frame
->top
= dummy_frame
->sp
;
1227 dummy_frame
->fp
= fp
;
1228 read_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1229 dummy_frame
->next
= dummy_frame_stack
;
1230 dummy_frame_stack
= dummy_frame
;
1234 generic_save_dummy_frame_tos (CORE_ADDR sp
)
1236 dummy_frame_stack
->top
= sp
;
1239 /* Record the upper/lower bounds on the address of the call dummy. */
1242 generic_save_call_dummy_addr (CORE_ADDR lo
, CORE_ADDR hi
)
1244 dummy_frame_stack
->call_lo
= lo
;
1245 dummy_frame_stack
->call_hi
= hi
;
1248 /* Restore the machine state from either the saved dummy stack or a
1249 real stack frame. */
1252 generic_pop_current_frame (void (*popper
) (struct frame_info
* frame
))
1254 struct frame_info
*frame
= get_current_frame ();
1256 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1257 generic_pop_dummy_frame ();
1262 /* Function: pop_dummy_frame
1263 Restore the machine state from a saved dummy stack frame. */
1266 generic_pop_dummy_frame (void)
1268 struct dummy_frame
*dummy_frame
= dummy_frame_stack
;
1270 /* FIXME: what if the first frame isn't the right one, eg..
1271 because one call-by-hand function has done a longjmp into another one? */
1274 error ("Can't pop dummy frame!");
1275 dummy_frame_stack
= dummy_frame
->next
;
1276 write_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1277 flush_cached_frames ();
1279 xfree (dummy_frame
->registers
);
1280 xfree (dummy_frame
);
1283 /* Function: frame_chain_valid
1284 Returns true for a user frame or a call_function_by_hand dummy frame,
1285 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1288 generic_file_frame_chain_valid (CORE_ADDR fp
, struct frame_info
*fi
)
1290 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi
), fp
, fp
))
1291 return 1; /* don't prune CALL_DUMMY frames */
1292 else /* fall back to default algorithm (see frame.h) */
1294 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1295 && !inside_entry_file (FRAME_SAVED_PC (fi
)));
1299 generic_func_frame_chain_valid (CORE_ADDR fp
, struct frame_info
*fi
)
1301 if (PC_IN_CALL_DUMMY ((fi
)->pc
, fp
, fp
))
1302 return 1; /* don't prune CALL_DUMMY frames */
1303 else /* fall back to default algorithm (see frame.h) */
1305 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1306 && !inside_main_func ((fi
)->pc
)
1307 && !inside_entry_func ((fi
)->pc
));
1310 /* Function: fix_call_dummy
1311 Stub function. Generic dummy frames typically do not need to fix
1312 the frame being created */
1315 generic_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
1316 struct value
**args
, struct type
*type
, int gcc_p
)
1321 /* Given a call-dummy dummy-frame, return the registers. Here the
1322 register value is taken from the local copy of the register buffer. */
1325 generic_call_dummy_register_unwind (struct frame_info
*frame
, void **cache
,
1326 int regnum
, int *optimized
,
1327 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
1328 int *realnum
, void *bufferp
)
1330 gdb_assert (frame
!= NULL
);
1331 gdb_assert (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
));
1333 /* Describe the register's location. Generic dummy frames always
1334 have the register value in an ``expression''. */
1340 /* If needed, find and return the value of the register. */
1341 if (bufferp
!= NULL
)
1345 /* Get the address of the register buffer that contains all the
1346 saved registers for this dummy frame. Cache that address. */
1347 registers
= (*cache
);
1348 if (registers
== NULL
)
1350 registers
= generic_find_dummy_frame (frame
->pc
, frame
->frame
);
1351 (*cache
) = registers
;
1354 /* Get the address of the register buffer that contains the
1355 saved registers and then extract the value from that. */
1356 registers
= generic_find_dummy_frame (frame
->pc
, frame
->frame
);
1358 gdb_assert (registers
!= NULL
);
1359 /* Return the actual value. */
1360 memcpy (bufferp
, registers
+ REGISTER_BYTE (regnum
),
1361 REGISTER_RAW_SIZE (regnum
));
1365 /* Return the register saved in the simplistic ``saved_regs'' cache.
1366 If the value isn't here AND a value is needed, try the next inner
1370 frame_saved_regs_register_unwind (struct frame_info
*frame
, void **cache
,
1371 int regnum
, int *optimizedp
,
1372 enum lval_type
*lvalp
, CORE_ADDR
*addrp
,
1373 int *realnump
, void *bufferp
)
1375 /* There is always a frame at this point. And THIS is the frame
1376 we're interested in. */
1377 gdb_assert (frame
!= NULL
);
1378 gdb_assert (!PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
));
1380 /* Load the saved_regs register cache. */
1381 if (frame
->saved_regs
== NULL
)
1382 FRAME_INIT_SAVED_REGS (frame
);
1384 if (frame
->saved_regs
!= NULL
1385 && frame
->saved_regs
[regnum
] != 0)
1387 if (regnum
== SP_REGNUM
)
1389 /* SP register treated specially. */
1394 if (bufferp
!= NULL
)
1395 store_address (bufferp
, REGISTER_RAW_SIZE (regnum
),
1396 frame
->saved_regs
[regnum
]);
1400 /* Any other register is saved in memory, fetch it but cache
1401 a local copy of its value. */
1403 *lvalp
= lval_memory
;
1404 *addrp
= frame
->saved_regs
[regnum
];
1406 if (bufferp
!= NULL
)
1409 /* Save each register value, as it is read in, in a
1410 frame based cache. */
1411 void **regs
= (*cache
);
1414 int sizeof_cache
= ((NUM_REGS
+ NUM_PSEUDO_REGS
)
1416 regs
= frame_obstack_alloc (sizeof_cache
);
1417 memset (regs
, 0, sizeof_cache
);
1420 if (regs
[regnum
] == NULL
)
1423 = frame_obstack_alloc (REGISTER_RAW_SIZE (regnum
));
1424 read_memory (frame
->saved_regs
[regnum
], regs
[regnum
],
1425 REGISTER_RAW_SIZE (regnum
));
1427 memcpy (bufferp
, regs
[regnum
], REGISTER_RAW_SIZE (regnum
));
1429 /* Read the value in from memory. */
1430 read_memory (frame
->saved_regs
[regnum
], bufferp
,
1431 REGISTER_RAW_SIZE (regnum
));
1438 /* No luck, assume this and the next frame have the same register
1439 value. If a value is needed, pass the request on down the chain;
1440 otherwise just return an indication that the value is in the same
1441 register as the next frame. */
1442 if (bufferp
== NULL
)
1445 *lvalp
= lval_register
;
1451 frame_register_unwind (frame
->next
, regnum
, optimizedp
, lvalp
, addrp
,
1456 /* Function: get_saved_register
1457 Find register number REGNUM relative to FRAME and put its (raw,
1458 target format) contents in *RAW_BUFFER.
1460 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1461 fetched). Note that this is never set to anything other than zero
1462 in this implementation.
1464 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1465 whether the value was fetched from memory, from a register, or in a
1466 strange and non-modifiable way (e.g. a frame pointer which was
1467 calculated rather than fetched). We will use not_lval for values
1468 fetched from generic dummy frames.
1470 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
1471 offset into the registers array. If the value is stored in a dummy
1472 frame, set *ADDRP to zero.
1474 To use this implementation, define a function called
1475 "get_saved_register" in your target code, which simply passes all
1476 of its arguments to this function.
1478 The argument RAW_BUFFER must point to aligned memory. */
1481 generic_get_saved_register (char *raw_buffer
, int *optimized
, CORE_ADDR
*addrp
,
1482 struct frame_info
*frame
, int regnum
,
1483 enum lval_type
*lval
)
1485 if (!target_has_registers
)
1486 error ("No registers.");
1488 /* Normal systems don't optimize out things with register numbers. */
1489 if (optimized
!= NULL
)
1492 if (addrp
) /* default assumption: not found in memory */
1495 /* Note: since the current frame's registers could only have been
1496 saved by frames INTERIOR TO the current frame, we skip examining
1497 the current frame itself: otherwise, we would be getting the
1498 previous frame's registers which were saved by the current frame. */
1500 while (frame
&& ((frame
= frame
->next
) != NULL
))
1502 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1504 if (lval
) /* found it in a CALL_DUMMY frame */
1508 generic_find_dummy_frame (frame
->pc
, frame
->frame
) +
1509 REGISTER_BYTE (regnum
),
1510 REGISTER_RAW_SIZE (regnum
));
1514 FRAME_INIT_SAVED_REGS (frame
);
1515 if (frame
->saved_regs
!= NULL
1516 && frame
->saved_regs
[regnum
] != 0)
1518 if (lval
) /* found it saved on the stack */
1519 *lval
= lval_memory
;
1520 if (regnum
== SP_REGNUM
)
1522 if (raw_buffer
) /* SP register treated specially */
1523 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
1524 frame
->saved_regs
[regnum
]);
1528 if (addrp
) /* any other register */
1529 *addrp
= frame
->saved_regs
[regnum
];
1531 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
1532 REGISTER_RAW_SIZE (regnum
));
1538 /* If we get thru the loop to this point, it means the register was
1539 not saved in any frame. Return the actual live-register value. */
1541 if (lval
) /* found it in a live register */
1542 *lval
= lval_register
;
1544 *addrp
= REGISTER_BYTE (regnum
);
1546 read_register_gen (regnum
, raw_buffer
);
1550 _initialize_blockframe (void)
1552 obstack_init (&frame_cache_obstack
);