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 */
38 /* Prototypes for exported functions. */
40 void _initialize_blockframe (void);
42 /* A default FRAME_CHAIN_VALID, in the form that is suitable for most
43 targets. If FRAME_CHAIN_VALID returns zero it means that the given
44 frame is the outermost one and has no caller. */
47 file_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
50 && !inside_entry_file (FRAME_SAVED_PC (thisframe
)));
53 /* Use the alternate method of avoiding running up off the end of the
54 frame chain or following frames back into the startup code. See
55 the comments in objfiles.h. */
58 func_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
61 && !inside_main_func ((thisframe
)->pc
)
62 && !inside_entry_func ((thisframe
)->pc
));
65 /* A very simple method of determining a valid frame */
68 nonnull_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
70 return ((chain
) != 0);
73 /* Is ADDR inside the startup file? Note that if your machine
74 has a way to detect the bottom of the stack, there is no need
75 to call this function from FRAME_CHAIN_VALID; the reason for
76 doing so is that some machines have no way of detecting bottom
79 A PC of zero is always considered to be the bottom of the stack. */
82 inside_entry_file (CORE_ADDR addr
)
86 if (symfile_objfile
== 0)
88 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
90 /* Do not stop backtracing if the pc is in the call dummy
91 at the entry point. */
92 /* FIXME: Won't always work with zeros for the last two arguments */
93 if (PC_IN_CALL_DUMMY (addr
, 0, 0))
96 return (addr
>= symfile_objfile
->ei
.entry_file_lowpc
&&
97 addr
< symfile_objfile
->ei
.entry_file_highpc
);
100 /* Test a specified PC value to see if it is in the range of addresses
101 that correspond to the main() function. See comments above for why
102 we might want to do this.
104 Typically called from FRAME_CHAIN_VALID.
106 A PC of zero is always considered to be the bottom of the stack. */
109 inside_main_func (CORE_ADDR pc
)
113 if (symfile_objfile
== 0)
116 /* If the addr range is not set up at symbol reading time, set it up now.
117 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
118 it is unable to set it up and symbol reading time. */
120 if (symfile_objfile
->ei
.main_func_lowpc
== INVALID_ENTRY_LOWPC
&&
121 symfile_objfile
->ei
.main_func_highpc
== INVALID_ENTRY_HIGHPC
)
123 struct symbol
*mainsym
;
125 mainsym
= lookup_symbol (main_name (), NULL
, VAR_NAMESPACE
, NULL
, NULL
);
126 if (mainsym
&& SYMBOL_CLASS (mainsym
) == LOC_BLOCK
)
128 symfile_objfile
->ei
.main_func_lowpc
=
129 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym
));
130 symfile_objfile
->ei
.main_func_highpc
=
131 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym
));
134 return (symfile_objfile
->ei
.main_func_lowpc
<= pc
&&
135 symfile_objfile
->ei
.main_func_highpc
> pc
);
138 /* Test a specified PC value to see if it is in the range of addresses
139 that correspond to the process entry point function. See comments
140 in objfiles.h for why we might want to do this.
142 Typically called from FRAME_CHAIN_VALID.
144 A PC of zero is always considered to be the bottom of the stack. */
147 inside_entry_func (CORE_ADDR pc
)
151 if (symfile_objfile
== 0)
153 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
155 /* Do not stop backtracing if the pc is in the call dummy
156 at the entry point. */
157 /* FIXME: Won't always work with zeros for the last two arguments */
158 if (PC_IN_CALL_DUMMY (pc
, 0, 0))
161 return (symfile_objfile
->ei
.entry_func_lowpc
<= pc
&&
162 symfile_objfile
->ei
.entry_func_highpc
> pc
);
165 /* Info about the innermost stack frame (contents of FP register) */
167 static struct frame_info
*current_frame
;
169 /* Cache for frame addresses already read by gdb. Valid only while
170 inferior is stopped. Control variables for the frame cache should
171 be local to this module. */
173 static struct obstack frame_cache_obstack
;
176 frame_obstack_alloc (unsigned long size
)
178 return obstack_alloc (&frame_cache_obstack
, size
);
182 frame_saved_regs_zalloc (struct frame_info
*fi
)
184 fi
->saved_regs
= (CORE_ADDR
*)
185 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
186 memset (fi
->saved_regs
, 0, SIZEOF_FRAME_SAVED_REGS
);
190 /* Return the innermost (currently executing) stack frame. */
193 get_current_frame (void)
195 if (current_frame
== NULL
)
197 if (target_has_stack
)
198 current_frame
= create_new_frame (read_fp (), read_pc ());
202 return current_frame
;
206 set_current_frame (struct frame_info
*frame
)
208 current_frame
= frame
;
211 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
212 Always returns a non-NULL value. */
215 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
217 struct frame_info
*fi
;
220 fi
= (struct frame_info
*)
221 obstack_alloc (&frame_cache_obstack
,
222 sizeof (struct frame_info
));
224 /* Zero all fields by default. */
225 memset (fi
, 0, sizeof (struct frame_info
));
229 find_pc_partial_function (pc
, &name
, (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
230 fi
->signal_handler_caller
= PC_IN_SIGTRAMP (fi
->pc
, name
);
232 if (INIT_EXTRA_FRAME_INFO_P ())
233 INIT_EXTRA_FRAME_INFO (0, fi
);
238 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
242 get_next_frame (struct frame_info
*frame
)
247 /* Flush the entire frame cache. */
250 flush_cached_frames (void)
252 /* Since we can't really be sure what the first object allocated was */
253 obstack_free (&frame_cache_obstack
, 0);
254 obstack_init (&frame_cache_obstack
);
256 current_frame
= NULL
; /* Invalidate cache */
257 select_frame (NULL
, -1);
258 annotate_frames_invalid ();
261 /* Flush the frame cache, and start a new one if necessary. */
264 reinit_frame_cache (void)
266 flush_cached_frames ();
268 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
269 if (PIDGET (inferior_ptid
) != 0)
271 select_frame (get_current_frame (), 0);
275 /* Return nonzero if the function for this frame lacks a prologue. Many
276 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
280 frameless_look_for_prologue (struct frame_info
*frame
)
282 CORE_ADDR func_start
, after_prologue
;
284 func_start
= get_pc_function_start (frame
->pc
);
287 func_start
+= FUNCTION_START_OFFSET
;
288 /* This is faster, since only care whether there *is* a
289 prologue, not how long it is. */
290 return PROLOGUE_FRAMELESS_P (func_start
);
292 else if (frame
->pc
== 0)
293 /* A frame with a zero PC is usually created by dereferencing a
294 NULL function pointer, normally causing an immediate core dump
295 of the inferior. Mark function as frameless, as the inferior
296 has no chance of setting up a stack frame. */
299 /* If we can't find the start of the function, we don't really
300 know whether the function is frameless, but we should be able
301 to get a reasonable (i.e. best we can do under the
302 circumstances) backtrace by saying that it isn't. */
306 /* Return a structure containing various interesting information
307 about the frame that called NEXT_FRAME. Returns NULL
308 if there is no such frame. */
311 get_prev_frame (struct frame_info
*next_frame
)
313 CORE_ADDR address
= 0;
314 struct frame_info
*prev
;
318 /* If the requested entry is in the cache, return it.
319 Otherwise, figure out what the address should be for the entry
320 we're about to add to the cache. */
325 /* This screws value_of_variable, which just wants a nice clean
326 NULL return from block_innermost_frame if there are no frames.
327 I don't think I've ever seen this message happen otherwise.
328 And returning NULL here is a perfectly legitimate thing to do. */
331 error ("You haven't set up a process's stack to examine.");
335 return current_frame
;
338 /* If we have the prev one, return it */
339 if (next_frame
->prev
)
340 return next_frame
->prev
;
342 /* On some machines it is possible to call a function without
343 setting up a stack frame for it. On these machines, we
344 define this macro to take two args; a frameinfo pointer
345 identifying a frame and a variable to set or clear if it is
346 or isn't leafless. */
348 /* Still don't want to worry about this except on the innermost
349 frame. This macro will set FROMLEAF if NEXT_FRAME is a
350 frameless function invocation. */
351 if (!(next_frame
->next
))
353 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
355 address
= FRAME_FP (next_frame
);
360 /* Two macros defined in tm.h specify the machine-dependent
361 actions to be performed here.
362 First, get the frame's chain-pointer.
363 If that is zero, the frame is the outermost frame or a leaf
364 called by the outermost frame. This means that if start
365 calls main without a frame, we'll return 0 (which is fine
368 Nope; there's a problem. This also returns when the current
369 routine is a leaf of main. This is unacceptable. We move
370 this to after the ffi test; I'd rather have backtraces from
371 start go curfluy than have an abort called from main not show
373 address
= FRAME_CHAIN (next_frame
);
374 if (!FRAME_CHAIN_VALID (address
, next_frame
))
380 prev
= (struct frame_info
*)
381 obstack_alloc (&frame_cache_obstack
,
382 sizeof (struct frame_info
));
384 /* Zero all fields by default. */
385 memset (prev
, 0, sizeof (struct frame_info
));
388 next_frame
->prev
= prev
;
389 prev
->next
= next_frame
;
390 prev
->frame
= address
;
391 prev
->level
= next_frame
->level
+ 1;
393 /* This change should not be needed, FIXME! We should
394 determine whether any targets *need* INIT_FRAME_PC to happen
395 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
396 express what goes on here.
398 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
399 (where the PC is already set up) and here (where it isn't).
400 INIT_FRAME_PC is only called from here, always after
401 INIT_EXTRA_FRAME_INFO.
403 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
404 value (which hasn't been set yet). Some other machines appear to
405 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
407 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
408 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
410 Assuming that some machines need INIT_FRAME_PC after
411 INIT_EXTRA_FRAME_INFO, one possible scheme:
413 SETUP_INNERMOST_FRAME()
414 Default version is just create_new_frame (read_fp ()),
415 read_pc ()). Machines with extra frame info would do that (or the
416 local equivalent) and then set the extra fields.
417 SETUP_ARBITRARY_FRAME(argc, argv)
418 Only change here is that create_new_frame would no longer init extra
419 frame info; SETUP_ARBITRARY_FRAME would have to do that.
420 INIT_PREV_FRAME(fromleaf, prev)
421 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
422 also return a flag saying whether to keep the new frame, or
423 whether to discard it, because on some machines (e.g. mips) it
424 is really awkward to have FRAME_CHAIN_VALID called *before*
425 INIT_EXTRA_FRAME_INFO (there is no good way to get information
426 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
427 std_frame_pc(fromleaf, prev)
428 This is the default setting for INIT_PREV_FRAME. It just does what
429 the default INIT_FRAME_PC does. Some machines will call it from
430 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
431 Some machines won't use it.
432 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
434 INIT_FRAME_PC_FIRST (fromleaf
, prev
);
436 if (INIT_EXTRA_FRAME_INFO_P ())
437 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
439 /* This entry is in the frame queue now, which is good since
440 FRAME_SAVED_PC may use that queue to figure out its value
441 (see tm-sparc.h). We want the pc saved in the inferior frame. */
442 INIT_FRAME_PC (fromleaf
, prev
);
444 /* If ->frame and ->pc are unchanged, we are in the process of getting
445 ourselves into an infinite backtrace. Some architectures check this
446 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
447 this can't be an architecture-independent check. */
448 if (next_frame
!= NULL
)
450 if (prev
->frame
== next_frame
->frame
451 && prev
->pc
== next_frame
->pc
)
453 next_frame
->prev
= NULL
;
454 obstack_free (&frame_cache_obstack
, prev
);
459 find_pc_partial_function (prev
->pc
, &name
,
460 (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
461 if (PC_IN_SIGTRAMP (prev
->pc
, name
))
462 prev
->signal_handler_caller
= 1;
468 get_frame_pc (struct frame_info
*frame
)
474 #ifdef FRAME_FIND_SAVED_REGS
475 /* XXX - deprecated. This is a compatibility function for targets
476 that do not yet implement FRAME_INIT_SAVED_REGS. */
477 /* Find the addresses in which registers are saved in FRAME. */
480 get_frame_saved_regs (struct frame_info
*frame
,
481 struct frame_saved_regs
*saved_regs_addr
)
483 if (frame
->saved_regs
== NULL
)
485 frame
->saved_regs
= (CORE_ADDR
*)
486 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
488 if (saved_regs_addr
== NULL
)
490 struct frame_saved_regs saved_regs
;
491 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
492 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
496 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
497 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
502 /* Return the innermost lexical block in execution
503 in a specified stack frame. The frame address is assumed valid.
505 If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
506 address we used to choose the block. We use this to find a source
507 line, to decide which macro definitions are in scope.
509 The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
510 PC, and may not really be a valid PC at all. For example, in the
511 caller of a function declared to never return, the code at the
512 return address will never be reached, so the call instruction may
513 be the very last instruction in the block. So the address we use
514 to choose the block is actually one byte before the return address
515 --- hopefully pointing us at the call instruction, or its delay
519 get_frame_block (struct frame_info
*frame
, CORE_ADDR
*addr_in_block
)
524 if (frame
->next
!= 0 && frame
->next
->signal_handler_caller
== 0)
525 /* We are not in the innermost frame and we were not interrupted
526 by a signal. We need to subtract one to get the correct block,
527 in case the call instruction was the last instruction of the block.
528 If there are any machines on which the saved pc does not point to
529 after the call insn, we probably want to make frame->pc point after
530 the call insn anyway. */
536 return block_for_pc (pc
);
540 get_current_block (CORE_ADDR
*addr_in_block
)
542 CORE_ADDR pc
= read_pc ();
547 return block_for_pc (pc
);
551 get_pc_function_start (CORE_ADDR pc
)
553 register struct block
*bl
;
554 register struct symbol
*symbol
;
555 register struct minimal_symbol
*msymbol
;
558 if ((bl
= block_for_pc (pc
)) != NULL
&&
559 (symbol
= block_function (bl
)) != NULL
)
561 bl
= SYMBOL_BLOCK_VALUE (symbol
);
562 fstart
= BLOCK_START (bl
);
564 else if ((msymbol
= lookup_minimal_symbol_by_pc (pc
)) != NULL
)
566 fstart
= SYMBOL_VALUE_ADDRESS (msymbol
);
575 /* Return the symbol for the function executing in frame FRAME. */
578 get_frame_function (struct frame_info
*frame
)
580 register struct block
*bl
= get_frame_block (frame
, 0);
583 return block_function (bl
);
587 /* Return the blockvector immediately containing the innermost lexical block
588 containing the specified pc value and section, or 0 if there is none.
589 PINDEX is a pointer to the index value of the block. If PINDEX
590 is NULL, we don't pass this information back to the caller. */
593 blockvector_for_pc_sect (register CORE_ADDR pc
, struct sec
*section
,
594 int *pindex
, struct symtab
*symtab
)
596 register struct block
*b
;
597 register int bot
, top
, half
;
598 struct blockvector
*bl
;
600 if (symtab
== 0) /* if no symtab specified by caller */
602 /* First search all symtabs for one whose file contains our pc */
603 if ((symtab
= find_pc_sect_symtab (pc
, section
)) == 0)
607 bl
= BLOCKVECTOR (symtab
);
608 b
= BLOCKVECTOR_BLOCK (bl
, 0);
610 /* Then search that symtab for the smallest block that wins. */
611 /* Use binary search to find the last block that starts before PC. */
614 top
= BLOCKVECTOR_NBLOCKS (bl
);
616 while (top
- bot
> 1)
618 half
= (top
- bot
+ 1) >> 1;
619 b
= BLOCKVECTOR_BLOCK (bl
, bot
+ half
);
620 if (BLOCK_START (b
) <= pc
)
626 /* Now search backward for a block that ends after PC. */
630 b
= BLOCKVECTOR_BLOCK (bl
, bot
);
631 if (BLOCK_END (b
) > pc
)
642 /* Return the blockvector immediately containing the innermost lexical block
643 containing the specified pc value, or 0 if there is none.
644 Backward compatibility, no section. */
647 blockvector_for_pc (register CORE_ADDR pc
, int *pindex
)
649 return blockvector_for_pc_sect (pc
, find_pc_mapped_section (pc
),
653 /* Return the innermost lexical block containing the specified pc value
654 in the specified section, or 0 if there is none. */
657 block_for_pc_sect (register CORE_ADDR pc
, struct sec
*section
)
659 register struct blockvector
*bl
;
662 bl
= blockvector_for_pc_sect (pc
, section
, &index
, NULL
);
664 return BLOCKVECTOR_BLOCK (bl
, index
);
668 /* Return the innermost lexical block containing the specified pc value,
669 or 0 if there is none. Backward compatibility, no section. */
672 block_for_pc (register CORE_ADDR pc
)
674 return block_for_pc_sect (pc
, find_pc_mapped_section (pc
));
677 /* Return the function containing pc value PC in section SECTION.
678 Returns 0 if function is not known. */
681 find_pc_sect_function (CORE_ADDR pc
, struct sec
*section
)
683 register struct block
*b
= block_for_pc_sect (pc
, section
);
686 return block_function (b
);
689 /* Return the function containing pc value PC.
690 Returns 0 if function is not known. Backward compatibility, no section */
693 find_pc_function (CORE_ADDR pc
)
695 return find_pc_sect_function (pc
, find_pc_mapped_section (pc
));
698 /* These variables are used to cache the most recent result
699 * of find_pc_partial_function. */
701 static CORE_ADDR cache_pc_function_low
= 0;
702 static CORE_ADDR cache_pc_function_high
= 0;
703 static char *cache_pc_function_name
= 0;
704 static struct sec
*cache_pc_function_section
= NULL
;
706 /* Clear cache, e.g. when symbol table is discarded. */
709 clear_pc_function_cache (void)
711 cache_pc_function_low
= 0;
712 cache_pc_function_high
= 0;
713 cache_pc_function_name
= (char *) 0;
714 cache_pc_function_section
= NULL
;
717 /* Finds the "function" (text symbol) that is smaller than PC but
718 greatest of all of the potential text symbols in SECTION. Sets
719 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
720 If ENDADDR is non-null, then set *ENDADDR to be the end of the
721 function (exclusive), but passing ENDADDR as non-null means that
722 the function might cause symbols to be read. This function either
723 succeeds or fails (not halfway succeeds). If it succeeds, it sets
724 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
725 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
729 find_pc_sect_partial_function (CORE_ADDR pc
, asection
*section
, char **name
,
730 CORE_ADDR
*address
, CORE_ADDR
*endaddr
)
732 struct partial_symtab
*pst
;
734 struct minimal_symbol
*msymbol
;
735 struct partial_symbol
*psb
;
736 struct obj_section
*osect
;
740 mapped_pc
= overlay_mapped_address (pc
, section
);
742 if (mapped_pc
>= cache_pc_function_low
&&
743 mapped_pc
< cache_pc_function_high
&&
744 section
== cache_pc_function_section
)
745 goto return_cached_value
;
747 /* If sigtramp is in the u area, it counts as a function (especially
748 important for step_1). */
749 #if defined SIGTRAMP_START
750 if (PC_IN_SIGTRAMP (mapped_pc
, (char *) NULL
))
752 cache_pc_function_low
= SIGTRAMP_START (mapped_pc
);
753 cache_pc_function_high
= SIGTRAMP_END (mapped_pc
);
754 cache_pc_function_name
= "<sigtramp>";
755 cache_pc_function_section
= section
;
756 goto return_cached_value
;
760 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
761 pst
= find_pc_sect_psymtab (mapped_pc
, section
);
764 /* Need to read the symbols to get a good value for the end address. */
765 if (endaddr
!= NULL
&& !pst
->readin
)
767 /* Need to get the terminal in case symbol-reading produces
769 target_terminal_ours_for_output ();
770 PSYMTAB_TO_SYMTAB (pst
);
775 /* Checking whether the msymbol has a larger value is for the
776 "pathological" case mentioned in print_frame_info. */
777 f
= find_pc_sect_function (mapped_pc
, section
);
780 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
781 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
783 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
784 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
785 cache_pc_function_name
= SYMBOL_NAME (f
);
786 cache_pc_function_section
= section
;
787 goto return_cached_value
;
792 /* Now that static symbols go in the minimal symbol table, perhaps
793 we could just ignore the partial symbols. But at least for now
794 we use the partial or minimal symbol, whichever is larger. */
795 psb
= find_pc_sect_psymbol (pst
, mapped_pc
, section
);
798 && (msymbol
== NULL
||
799 (SYMBOL_VALUE_ADDRESS (psb
)
800 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
802 /* This case isn't being cached currently. */
804 *address
= SYMBOL_VALUE_ADDRESS (psb
);
806 *name
= SYMBOL_NAME (psb
);
807 /* endaddr non-NULL can't happen here. */
813 /* Not in the normal symbol tables, see if the pc is in a known section.
814 If it's not, then give up. This ensures that anything beyond the end
815 of the text seg doesn't appear to be part of the last function in the
818 osect
= find_pc_sect_section (mapped_pc
, section
);
823 /* Must be in the minimal symbol table. */
826 /* No available symbol. */
836 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
837 cache_pc_function_name
= SYMBOL_NAME (msymbol
);
838 cache_pc_function_section
= section
;
840 /* Use the lesser of the next minimal symbol in the same section, or
841 the end of the section, as the end of the function. */
843 /* Step over other symbols at this same address, and symbols in
844 other sections, to find the next symbol in this section with
845 a different address. */
847 for (i
= 1; SYMBOL_NAME (msymbol
+ i
) != NULL
; i
++)
849 if (SYMBOL_VALUE_ADDRESS (msymbol
+ i
) != SYMBOL_VALUE_ADDRESS (msymbol
)
850 && SYMBOL_BFD_SECTION (msymbol
+ i
) == SYMBOL_BFD_SECTION (msymbol
))
854 if (SYMBOL_NAME (msymbol
+ i
) != NULL
855 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
) < osect
->endaddr
)
856 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
858 /* We got the start address from the last msymbol in the objfile.
859 So the end address is the end of the section. */
860 cache_pc_function_high
= osect
->endaddr
;
866 if (pc_in_unmapped_range (pc
, section
))
867 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
869 *address
= cache_pc_function_low
;
873 *name
= cache_pc_function_name
;
877 if (pc_in_unmapped_range (pc
, section
))
879 /* Because the high address is actually beyond the end of
880 the function (and therefore possibly beyond the end of
881 the overlay), we must actually convert (high - 1)
882 and then add one to that. */
884 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
888 *endaddr
= cache_pc_function_high
;
894 /* Backward compatibility, no section argument */
897 find_pc_partial_function (CORE_ADDR pc
, char **name
, CORE_ADDR
*address
,
902 section
= find_pc_overlay (pc
);
903 return find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
);
906 /* Return the innermost stack frame executing inside of BLOCK,
907 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
910 block_innermost_frame (struct block
*block
)
912 struct frame_info
*frame
;
913 register CORE_ADDR start
;
914 register CORE_ADDR end
;
919 start
= BLOCK_START (block
);
920 end
= BLOCK_END (block
);
925 frame
= get_prev_frame (frame
);
928 if (frame
->pc
>= start
&& frame
->pc
< end
)
933 /* Return the full FRAME which corresponds to the given CORE_ADDR
934 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
937 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr
)
939 struct frame_info
*frame
= NULL
;
941 if (frame_addr
== (CORE_ADDR
) 0)
946 frame
= get_prev_frame (frame
);
949 if (FRAME_FP (frame
) == frame_addr
)
954 #ifdef SIGCONTEXT_PC_OFFSET
955 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
958 sigtramp_saved_pc (struct frame_info
*frame
)
960 CORE_ADDR sigcontext_addr
;
962 int ptrbytes
= TARGET_PTR_BIT
/ TARGET_CHAR_BIT
;
963 int sigcontext_offs
= (2 * TARGET_INT_BIT
) / TARGET_CHAR_BIT
;
965 buf
= alloca (ptrbytes
);
966 /* Get sigcontext address, it is the third parameter on the stack. */
968 sigcontext_addr
= read_memory_integer (FRAME_ARGS_ADDRESS (frame
->next
)
973 sigcontext_addr
= read_memory_integer (read_register (SP_REGNUM
)
977 /* Don't cause a memory_error when accessing sigcontext in case the stack
978 layout has changed or the stack is corrupt. */
979 target_read_memory (sigcontext_addr
+ SIGCONTEXT_PC_OFFSET
, buf
, ptrbytes
);
980 return extract_unsigned_integer (buf
, ptrbytes
);
982 #endif /* SIGCONTEXT_PC_OFFSET */
985 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
986 below is for infrun.c, which may give the macro a pc without that
989 extern CORE_ADDR text_end
;
992 pc_in_call_dummy_before_text_end (CORE_ADDR pc
, CORE_ADDR sp
,
993 CORE_ADDR frame_address
)
995 return ((pc
) >= text_end
- CALL_DUMMY_LENGTH
996 && (pc
) <= text_end
+ DECR_PC_AFTER_BREAK
);
1000 pc_in_call_dummy_after_text_end (CORE_ADDR pc
, CORE_ADDR sp
,
1001 CORE_ADDR frame_address
)
1003 return ((pc
) >= text_end
1004 && (pc
) <= text_end
+ CALL_DUMMY_LENGTH
+ DECR_PC_AFTER_BREAK
);
1007 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1008 top of the stack frame which we are checking, where "bottom" and
1009 "top" refer to some section of memory which contains the code for
1010 the call dummy. Calls to this macro assume that the contents of
1011 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1012 are the things to pass.
1014 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1015 have that meaning, but the 29k doesn't use ON_STACK. This could be
1016 fixed by generalizing this scheme, perhaps by passing in a frame
1017 and adding a few fields, at least on machines which need them for
1020 Something simpler, like checking for the stack segment, doesn't work,
1021 since various programs (threads implementations, gcc nested function
1022 stubs, etc) may either allocate stack frames in another segment, or
1023 allocate other kinds of code on the stack. */
1026 pc_in_call_dummy_on_stack (CORE_ADDR pc
, CORE_ADDR sp
, CORE_ADDR frame_address
)
1028 return (INNER_THAN ((sp
), (pc
))
1029 && (frame_address
!= 0)
1030 && INNER_THAN ((pc
), (frame_address
)));
1034 pc_in_call_dummy_at_entry_point (CORE_ADDR pc
, CORE_ADDR sp
,
1035 CORE_ADDR frame_address
)
1037 return ((pc
) >= CALL_DUMMY_ADDRESS ()
1038 && (pc
) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK
));
1043 * GENERIC DUMMY FRAMES
1045 * The following code serves to maintain the dummy stack frames for
1046 * inferior function calls (ie. when gdb calls into the inferior via
1047 * call_function_by_hand). This code saves the machine state before
1048 * the call in host memory, so we must maintain an independent stack
1049 * and keep it consistant etc. I am attempting to make this code
1050 * generic enough to be used by many targets.
1052 * The cheapest and most generic way to do CALL_DUMMY on a new target
1053 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1054 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1055 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1056 * being executed by the target. Also FRAME_CHAIN_VALID as
1057 * generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
1058 * generic_fix_call_dummy. */
1060 /* Dummy frame. This saves the processor state just prior to setting
1061 up the inferior function call. Older targets save the registers
1062 on the target stack (but that really slows down function calls). */
1066 struct dummy_frame
*next
;
1075 static struct dummy_frame
*dummy_frame_stack
= NULL
;
1077 /* Function: find_dummy_frame(pc, fp, sp)
1078 Search the stack of dummy frames for one matching the given PC, FP and SP.
1079 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1082 generic_find_dummy_frame (CORE_ADDR pc
, CORE_ADDR fp
)
1084 struct dummy_frame
*dummyframe
;
1086 if (pc
!= entry_point_address ())
1089 for (dummyframe
= dummy_frame_stack
; dummyframe
!= NULL
;
1090 dummyframe
= dummyframe
->next
)
1091 if (fp
== dummyframe
->fp
1092 || fp
== dummyframe
->sp
1093 || fp
== dummyframe
->top
)
1094 /* The frame in question lies between the saved fp and sp, inclusive */
1095 return dummyframe
->registers
;
1100 /* Function: pc_in_call_dummy (pc, fp)
1101 Return true if this is a dummy frame created by gdb for an inferior call */
1104 generic_pc_in_call_dummy (CORE_ADDR pc
, CORE_ADDR sp
, CORE_ADDR fp
)
1106 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1107 /* Note: SP and not FP is passed on. */
1108 return (generic_find_dummy_frame (pc
, sp
) != 0);
1111 /* Function: read_register_dummy
1112 Find a saved register from before GDB calls a function in the inferior */
1115 generic_read_register_dummy (CORE_ADDR pc
, CORE_ADDR fp
, int regno
)
1117 char *dummy_regs
= generic_find_dummy_frame (pc
, fp
);
1120 return extract_address (&dummy_regs
[REGISTER_BYTE (regno
)],
1121 REGISTER_RAW_SIZE (regno
));
1126 /* Save all the registers on the dummy frame stack. Most ports save the
1127 registers on the target stack. This results in lots of unnecessary memory
1128 references, which are slow when debugging via a serial line. Instead, we
1129 save all the registers internally, and never write them to the stack. The
1130 registers get restored when the called function returns to the entry point,
1131 where a breakpoint is laying in wait. */
1134 generic_push_dummy_frame (void)
1136 struct dummy_frame
*dummy_frame
;
1137 CORE_ADDR fp
= (get_current_frame ())->frame
;
1139 /* check to see if there are stale dummy frames,
1140 perhaps left over from when a longjump took us out of a
1141 function that was called by the debugger */
1143 dummy_frame
= dummy_frame_stack
;
1145 if (INNER_THAN (dummy_frame
->fp
, fp
)) /* stale -- destroy! */
1147 dummy_frame_stack
= dummy_frame
->next
;
1148 xfree (dummy_frame
->registers
);
1149 xfree (dummy_frame
);
1150 dummy_frame
= dummy_frame_stack
;
1153 dummy_frame
= dummy_frame
->next
;
1155 dummy_frame
= xmalloc (sizeof (struct dummy_frame
));
1156 dummy_frame
->registers
= xmalloc (REGISTER_BYTES
);
1158 dummy_frame
->pc
= read_pc ();
1159 dummy_frame
->sp
= read_sp ();
1160 dummy_frame
->top
= dummy_frame
->sp
;
1161 dummy_frame
->fp
= fp
;
1162 read_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1163 dummy_frame
->next
= dummy_frame_stack
;
1164 dummy_frame_stack
= dummy_frame
;
1168 generic_save_dummy_frame_tos (CORE_ADDR sp
)
1170 dummy_frame_stack
->top
= sp
;
1173 /* Restore the machine state from either the saved dummy stack or a
1174 real stack frame. */
1177 generic_pop_current_frame (void (*popper
) (struct frame_info
* frame
))
1179 struct frame_info
*frame
= get_current_frame ();
1181 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1182 generic_pop_dummy_frame ();
1187 /* Function: pop_dummy_frame
1188 Restore the machine state from a saved dummy stack frame. */
1191 generic_pop_dummy_frame (void)
1193 struct dummy_frame
*dummy_frame
= dummy_frame_stack
;
1195 /* FIXME: what if the first frame isn't the right one, eg..
1196 because one call-by-hand function has done a longjmp into another one? */
1199 error ("Can't pop dummy frame!");
1200 dummy_frame_stack
= dummy_frame
->next
;
1201 write_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1202 flush_cached_frames ();
1204 xfree (dummy_frame
->registers
);
1205 xfree (dummy_frame
);
1208 /* Function: frame_chain_valid
1209 Returns true for a user frame or a call_function_by_hand dummy frame,
1210 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1213 generic_file_frame_chain_valid (CORE_ADDR fp
, struct frame_info
*fi
)
1215 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi
), fp
, fp
))
1216 return 1; /* don't prune CALL_DUMMY frames */
1217 else /* fall back to default algorithm (see frame.h) */
1219 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1220 && !inside_entry_file (FRAME_SAVED_PC (fi
)));
1224 generic_func_frame_chain_valid (CORE_ADDR fp
, struct frame_info
*fi
)
1226 if (PC_IN_CALL_DUMMY ((fi
)->pc
, fp
, fp
))
1227 return 1; /* don't prune CALL_DUMMY frames */
1228 else /* fall back to default algorithm (see frame.h) */
1230 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1231 && !inside_main_func ((fi
)->pc
)
1232 && !inside_entry_func ((fi
)->pc
));
1235 /* Function: fix_call_dummy
1236 Stub function. Generic dummy frames typically do not need to fix
1237 the frame being created */
1240 generic_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
1241 struct value
**args
, struct type
*type
, int gcc_p
)
1246 /* Function: get_saved_register
1247 Find register number REGNUM relative to FRAME and put its (raw,
1248 target format) contents in *RAW_BUFFER.
1250 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1251 fetched). Note that this is never set to anything other than zero
1252 in this implementation.
1254 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1255 whether the value was fetched from memory, from a register, or in a
1256 strange and non-modifiable way (e.g. a frame pointer which was
1257 calculated rather than fetched). We will use not_lval for values
1258 fetched from generic dummy frames.
1260 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
1261 offset into the registers array. If the value is stored in a dummy
1262 frame, set *ADDRP to zero.
1264 To use this implementation, define a function called
1265 "get_saved_register" in your target code, which simply passes all
1266 of its arguments to this function.
1268 The argument RAW_BUFFER must point to aligned memory. */
1271 generic_get_saved_register (char *raw_buffer
, int *optimized
, CORE_ADDR
*addrp
,
1272 struct frame_info
*frame
, int regnum
,
1273 enum lval_type
*lval
)
1275 if (!target_has_registers
)
1276 error ("No registers.");
1278 /* Normal systems don't optimize out things with register numbers. */
1279 if (optimized
!= NULL
)
1282 if (addrp
) /* default assumption: not found in memory */
1285 /* Note: since the current frame's registers could only have been
1286 saved by frames INTERIOR TO the current frame, we skip examining
1287 the current frame itself: otherwise, we would be getting the
1288 previous frame's registers which were saved by the current frame. */
1290 while (frame
&& ((frame
= frame
->next
) != NULL
))
1292 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1294 if (lval
) /* found it in a CALL_DUMMY frame */
1298 generic_find_dummy_frame (frame
->pc
, frame
->frame
) +
1299 REGISTER_BYTE (regnum
),
1300 REGISTER_RAW_SIZE (regnum
));
1304 FRAME_INIT_SAVED_REGS (frame
);
1305 if (frame
->saved_regs
!= NULL
1306 && frame
->saved_regs
[regnum
] != 0)
1308 if (lval
) /* found it saved on the stack */
1309 *lval
= lval_memory
;
1310 if (regnum
== SP_REGNUM
)
1312 if (raw_buffer
) /* SP register treated specially */
1313 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
1314 frame
->saved_regs
[regnum
]);
1318 if (addrp
) /* any other register */
1319 *addrp
= frame
->saved_regs
[regnum
];
1321 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
1322 REGISTER_RAW_SIZE (regnum
));
1328 /* If we get thru the loop to this point, it means the register was
1329 not saved in any frame. Return the actual live-register value. */
1331 if (lval
) /* found it in a live register */
1332 *lval
= lval_register
;
1334 *addrp
= REGISTER_BYTE (regnum
);
1336 read_register_gen (regnum
, raw_buffer
);
1340 _initialize_blockframe (void)
1342 obstack_init (&frame_cache_obstack
);