1 /* Get info from stack frames;
2 convert between frames, blocks, functions and pc values.
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
30 #include "value.h" /* for read_register */
31 #include "target.h" /* for target_has_stack */
32 #include "inferior.h" /* for read_pc */
36 /* Prototypes for exported functions. */
38 void _initialize_blockframe (void);
40 /* A default FRAME_CHAIN_VALID, in the form that is suitable for most
41 targets. If FRAME_CHAIN_VALID returns zero it means that the given
42 frame is the outermost one and has no caller. */
45 file_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
48 && !inside_entry_file (FRAME_SAVED_PC (thisframe
)));
51 /* Use the alternate method of avoiding running up off the end of the
52 frame chain or following frames back into the startup code. See
53 the comments in objfiles.h. */
56 func_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
59 && !inside_main_func ((thisframe
)->pc
)
60 && !inside_entry_func ((thisframe
)->pc
));
63 /* A very simple method of determining a valid frame */
66 nonnull_frame_chain_valid (CORE_ADDR chain
, struct frame_info
*thisframe
)
68 return ((chain
) != 0);
71 /* Is ADDR inside the startup file? Note that if your machine
72 has a way to detect the bottom of the stack, there is no need
73 to call this function from FRAME_CHAIN_VALID; the reason for
74 doing so is that some machines have no way of detecting bottom
77 A PC of zero is always considered to be the bottom of the stack. */
80 inside_entry_file (CORE_ADDR addr
)
84 if (symfile_objfile
== 0)
86 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
88 /* Do not stop backtracing if the pc is in the call dummy
89 at the entry point. */
90 /* FIXME: Won't always work with zeros for the last two arguments */
91 if (PC_IN_CALL_DUMMY (addr
, 0, 0))
94 return (addr
>= symfile_objfile
->ei
.entry_file_lowpc
&&
95 addr
< symfile_objfile
->ei
.entry_file_highpc
);
98 /* Test a specified PC value to see if it is in the range of addresses
99 that correspond to the main() function. See comments above for why
100 we might want to do this.
102 Typically called from FRAME_CHAIN_VALID.
104 A PC of zero is always considered to be the bottom of the stack. */
107 inside_main_func (CORE_ADDR pc
)
111 if (symfile_objfile
== 0)
114 /* If the addr range is not set up at symbol reading time, set it up now.
115 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
116 it is unable to set it up and symbol reading time. */
118 if (symfile_objfile
->ei
.main_func_lowpc
== INVALID_ENTRY_LOWPC
&&
119 symfile_objfile
->ei
.main_func_highpc
== INVALID_ENTRY_HIGHPC
)
121 struct symbol
*mainsym
;
123 mainsym
= lookup_symbol ("main", NULL
, VAR_NAMESPACE
, NULL
, NULL
);
124 if (mainsym
&& SYMBOL_CLASS (mainsym
) == LOC_BLOCK
)
126 symfile_objfile
->ei
.main_func_lowpc
=
127 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym
));
128 symfile_objfile
->ei
.main_func_highpc
=
129 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym
));
132 return (symfile_objfile
->ei
.main_func_lowpc
<= pc
&&
133 symfile_objfile
->ei
.main_func_highpc
> pc
);
136 /* Test a specified PC value to see if it is in the range of addresses
137 that correspond to the process entry point function. See comments
138 in objfiles.h for why we might want to do this.
140 Typically called from FRAME_CHAIN_VALID.
142 A PC of zero is always considered to be the bottom of the stack. */
145 inside_entry_func (CORE_ADDR pc
)
149 if (symfile_objfile
== 0)
151 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
153 /* Do not stop backtracing if the pc is in the call dummy
154 at the entry point. */
155 /* FIXME: Won't always work with zeros for the last two arguments */
156 if (PC_IN_CALL_DUMMY (pc
, 0, 0))
159 return (symfile_objfile
->ei
.entry_func_lowpc
<= pc
&&
160 symfile_objfile
->ei
.entry_func_highpc
> pc
);
163 /* Info about the innermost stack frame (contents of FP register) */
165 static struct frame_info
*current_frame
;
167 /* Cache for frame addresses already read by gdb. Valid only while
168 inferior is stopped. Control variables for the frame cache should
169 be local to this module. */
171 static struct obstack frame_cache_obstack
;
174 frame_obstack_alloc (unsigned long size
)
176 return obstack_alloc (&frame_cache_obstack
, size
);
180 frame_saved_regs_zalloc (struct frame_info
*fi
)
182 fi
->saved_regs
= (CORE_ADDR
*)
183 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
184 memset (fi
->saved_regs
, 0, SIZEOF_FRAME_SAVED_REGS
);
188 /* Return the innermost (currently executing) stack frame. */
191 get_current_frame (void)
193 if (current_frame
== NULL
)
195 if (target_has_stack
)
196 current_frame
= create_new_frame (read_fp (), read_pc ());
200 return current_frame
;
204 set_current_frame (struct frame_info
*frame
)
206 current_frame
= frame
;
209 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
210 Always returns a non-NULL value. */
213 create_new_frame (CORE_ADDR addr
, CORE_ADDR pc
)
215 struct frame_info
*fi
;
218 fi
= (struct frame_info
*)
219 obstack_alloc (&frame_cache_obstack
,
220 sizeof (struct frame_info
));
222 /* Zero all fields by default. */
223 memset (fi
, 0, sizeof (struct frame_info
));
227 find_pc_partial_function (pc
, &name
, (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
228 fi
->signal_handler_caller
= IN_SIGTRAMP (fi
->pc
, name
);
230 #ifdef INIT_EXTRA_FRAME_INFO
231 INIT_EXTRA_FRAME_INFO (0, fi
);
237 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
241 get_next_frame (struct frame_info
*frame
)
246 /* Flush the entire frame cache. */
249 flush_cached_frames (void)
251 /* Since we can't really be sure what the first object allocated was */
252 obstack_free (&frame_cache_obstack
, 0);
253 obstack_init (&frame_cache_obstack
);
255 current_frame
= NULL
; /* Invalidate cache */
256 select_frame (NULL
, -1);
257 annotate_frames_invalid ();
260 /* Flush the frame cache, and start a new one if necessary. */
263 reinit_frame_cache (void)
265 flush_cached_frames ();
267 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
268 if (PIDGET (inferior_ptid
) != 0)
270 select_frame (get_current_frame (), 0);
274 /* Return nonzero if the function for this frame lacks a prologue. Many
275 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
279 frameless_look_for_prologue (struct frame_info
*frame
)
281 CORE_ADDR func_start
, after_prologue
;
283 func_start
= get_pc_function_start (frame
->pc
);
286 func_start
+= FUNCTION_START_OFFSET
;
287 /* This is faster, since only care whether there *is* a
288 prologue, not how long it is. */
289 return PROLOGUE_FRAMELESS_P (func_start
);
291 else if (frame
->pc
== 0)
292 /* A frame with a zero PC is usually created by dereferencing a
293 NULL function pointer, normally causing an immediate core dump
294 of the inferior. Mark function as frameless, as the inferior
295 has no chance of setting up a stack frame. */
298 /* If we can't find the start of the function, we don't really
299 know whether the function is frameless, but we should be able
300 to get a reasonable (i.e. best we can do under the
301 circumstances) backtrace by saying that it isn't. */
305 /* Default a few macros that people seldom redefine. */
307 #ifndef FRAME_CHAIN_COMBINE
308 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
311 /* Return a structure containing various interesting information
312 about the frame that called NEXT_FRAME. Returns NULL
313 if there is no such frame. */
316 get_prev_frame (struct frame_info
*next_frame
)
318 CORE_ADDR address
= 0;
319 struct frame_info
*prev
;
323 /* If the requested entry is in the cache, return it.
324 Otherwise, figure out what the address should be for the entry
325 we're about to add to the cache. */
330 /* This screws value_of_variable, which just wants a nice clean
331 NULL return from block_innermost_frame if there are no frames.
332 I don't think I've ever seen this message happen otherwise.
333 And returning NULL here is a perfectly legitimate thing to do. */
336 error ("You haven't set up a process's stack to examine.");
340 return current_frame
;
343 /* If we have the prev one, return it */
344 if (next_frame
->prev
)
345 return next_frame
->prev
;
347 /* On some machines it is possible to call a function without
348 setting up a stack frame for it. On these machines, we
349 define this macro to take two args; a frameinfo pointer
350 identifying a frame and a variable to set or clear if it is
351 or isn't leafless. */
353 /* Still don't want to worry about this except on the innermost
354 frame. This macro will set FROMLEAF if NEXT_FRAME is a
355 frameless function invocation. */
356 if (!(next_frame
->next
))
358 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
360 address
= FRAME_FP (next_frame
);
365 /* Two macros defined in tm.h specify the machine-dependent
366 actions to be performed here.
367 First, get the frame's chain-pointer.
368 If that is zero, the frame is the outermost frame or a leaf
369 called by the outermost frame. This means that if start
370 calls main without a frame, we'll return 0 (which is fine
373 Nope; there's a problem. This also returns when the current
374 routine is a leaf of main. This is unacceptable. We move
375 this to after the ffi test; I'd rather have backtraces from
376 start go curfluy than have an abort called from main not show
378 address
= FRAME_CHAIN (next_frame
);
379 if (!FRAME_CHAIN_VALID (address
, next_frame
))
381 address
= FRAME_CHAIN_COMBINE (address
, next_frame
);
386 prev
= (struct frame_info
*)
387 obstack_alloc (&frame_cache_obstack
,
388 sizeof (struct frame_info
));
390 /* Zero all fields by default. */
391 memset (prev
, 0, sizeof (struct frame_info
));
394 next_frame
->prev
= prev
;
395 prev
->next
= next_frame
;
396 prev
->frame
= address
;
398 /* This change should not be needed, FIXME! We should
399 determine whether any targets *need* INIT_FRAME_PC to happen
400 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
401 express what goes on here.
403 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
404 (where the PC is already set up) and here (where it isn't).
405 INIT_FRAME_PC is only called from here, always after
406 INIT_EXTRA_FRAME_INFO.
408 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
409 value (which hasn't been set yet). Some other machines appear to
410 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
412 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
413 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
415 Assuming that some machines need INIT_FRAME_PC after
416 INIT_EXTRA_FRAME_INFO, one possible scheme:
418 SETUP_INNERMOST_FRAME()
419 Default version is just create_new_frame (read_fp ()),
420 read_pc ()). Machines with extra frame info would do that (or the
421 local equivalent) and then set the extra fields.
422 SETUP_ARBITRARY_FRAME(argc, argv)
423 Only change here is that create_new_frame would no longer init extra
424 frame info; SETUP_ARBITRARY_FRAME would have to do that.
425 INIT_PREV_FRAME(fromleaf, prev)
426 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
427 also return a flag saying whether to keep the new frame, or
428 whether to discard it, because on some machines (e.g. mips) it
429 is really awkward to have FRAME_CHAIN_VALID called *before*
430 INIT_EXTRA_FRAME_INFO (there is no good way to get information
431 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
432 std_frame_pc(fromleaf, prev)
433 This is the default setting for INIT_PREV_FRAME. It just does what
434 the default INIT_FRAME_PC does. Some machines will call it from
435 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
436 Some machines won't use it.
437 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
439 INIT_FRAME_PC_FIRST (fromleaf
, prev
);
441 #ifdef INIT_EXTRA_FRAME_INFO
442 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
445 /* This entry is in the frame queue now, which is good since
446 FRAME_SAVED_PC may use that queue to figure out its value
447 (see tm-sparc.h). We want the pc saved in the inferior frame. */
448 INIT_FRAME_PC (fromleaf
, prev
);
450 /* If ->frame and ->pc are unchanged, we are in the process of getting
451 ourselves into an infinite backtrace. Some architectures check this
452 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
453 this can't be an architecture-independent check. */
454 if (next_frame
!= NULL
)
456 if (prev
->frame
== next_frame
->frame
457 && prev
->pc
== next_frame
->pc
)
459 next_frame
->prev
= NULL
;
460 obstack_free (&frame_cache_obstack
, prev
);
465 find_pc_partial_function (prev
->pc
, &name
,
466 (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
467 if (IN_SIGTRAMP (prev
->pc
, name
))
468 prev
->signal_handler_caller
= 1;
474 get_frame_pc (struct frame_info
*frame
)
480 #ifdef FRAME_FIND_SAVED_REGS
481 /* XXX - deprecated. This is a compatibility function for targets
482 that do not yet implement FRAME_INIT_SAVED_REGS. */
483 /* Find the addresses in which registers are saved in FRAME. */
486 get_frame_saved_regs (struct frame_info
*frame
,
487 struct frame_saved_regs
*saved_regs_addr
)
489 if (frame
->saved_regs
== NULL
)
491 frame
->saved_regs
= (CORE_ADDR
*)
492 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
494 if (saved_regs_addr
== NULL
)
496 struct frame_saved_regs saved_regs
;
497 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
498 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
502 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
503 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
508 /* Return the innermost lexical block in execution
509 in a specified stack frame. The frame address is assumed valid. */
512 get_frame_block (struct frame_info
*frame
)
517 if (frame
->next
!= 0 && frame
->next
->signal_handler_caller
== 0)
518 /* We are not in the innermost frame and we were not interrupted
519 by a signal. We need to subtract one to get the correct block,
520 in case the call instruction was the last instruction of the block.
521 If there are any machines on which the saved pc does not point to
522 after the call insn, we probably want to make frame->pc point after
523 the call insn anyway. */
525 return block_for_pc (pc
);
529 get_current_block (void)
531 return block_for_pc (read_pc ());
535 get_pc_function_start (CORE_ADDR pc
)
537 register struct block
*bl
;
538 register struct symbol
*symbol
;
539 register struct minimal_symbol
*msymbol
;
542 if ((bl
= block_for_pc (pc
)) != NULL
&&
543 (symbol
= block_function (bl
)) != NULL
)
545 bl
= SYMBOL_BLOCK_VALUE (symbol
);
546 fstart
= BLOCK_START (bl
);
548 else if ((msymbol
= lookup_minimal_symbol_by_pc (pc
)) != NULL
)
550 fstart
= SYMBOL_VALUE_ADDRESS (msymbol
);
559 /* Return the symbol for the function executing in frame FRAME. */
562 get_frame_function (struct frame_info
*frame
)
564 register struct block
*bl
= get_frame_block (frame
);
567 return block_function (bl
);
571 /* Return the blockvector immediately containing the innermost lexical block
572 containing the specified pc value and section, or 0 if there is none.
573 PINDEX is a pointer to the index value of the block. If PINDEX
574 is NULL, we don't pass this information back to the caller. */
577 blockvector_for_pc_sect (register CORE_ADDR pc
, struct sec
*section
,
578 int *pindex
, struct symtab
*symtab
)
580 register struct block
*b
;
581 register int bot
, top
, half
;
582 struct blockvector
*bl
;
584 if (symtab
== 0) /* if no symtab specified by caller */
586 /* First search all symtabs for one whose file contains our pc */
587 if ((symtab
= find_pc_sect_symtab (pc
, section
)) == 0)
591 bl
= BLOCKVECTOR (symtab
);
592 b
= BLOCKVECTOR_BLOCK (bl
, 0);
594 /* Then search that symtab for the smallest block that wins. */
595 /* Use binary search to find the last block that starts before PC. */
598 top
= BLOCKVECTOR_NBLOCKS (bl
);
600 while (top
- bot
> 1)
602 half
= (top
- bot
+ 1) >> 1;
603 b
= BLOCKVECTOR_BLOCK (bl
, bot
+ half
);
604 if (BLOCK_START (b
) <= pc
)
610 /* Now search backward for a block that ends after PC. */
614 b
= BLOCKVECTOR_BLOCK (bl
, bot
);
615 if (BLOCK_END (b
) > pc
)
626 /* Return the blockvector immediately containing the innermost lexical block
627 containing the specified pc value, or 0 if there is none.
628 Backward compatibility, no section. */
631 blockvector_for_pc (register CORE_ADDR pc
, int *pindex
)
633 return blockvector_for_pc_sect (pc
, find_pc_mapped_section (pc
),
637 /* Return the innermost lexical block containing the specified pc value
638 in the specified section, or 0 if there is none. */
641 block_for_pc_sect (register CORE_ADDR pc
, struct sec
*section
)
643 register struct blockvector
*bl
;
646 bl
= blockvector_for_pc_sect (pc
, section
, &index
, NULL
);
648 return BLOCKVECTOR_BLOCK (bl
, index
);
652 /* Return the innermost lexical block containing the specified pc value,
653 or 0 if there is none. Backward compatibility, no section. */
656 block_for_pc (register CORE_ADDR pc
)
658 return block_for_pc_sect (pc
, find_pc_mapped_section (pc
));
661 /* Return the function containing pc value PC in section SECTION.
662 Returns 0 if function is not known. */
665 find_pc_sect_function (CORE_ADDR pc
, struct sec
*section
)
667 register struct block
*b
= block_for_pc_sect (pc
, section
);
670 return block_function (b
);
673 /* Return the function containing pc value PC.
674 Returns 0 if function is not known. Backward compatibility, no section */
677 find_pc_function (CORE_ADDR pc
)
679 return find_pc_sect_function (pc
, find_pc_mapped_section (pc
));
682 /* These variables are used to cache the most recent result
683 * of find_pc_partial_function. */
685 static CORE_ADDR cache_pc_function_low
= 0;
686 static CORE_ADDR cache_pc_function_high
= 0;
687 static char *cache_pc_function_name
= 0;
688 static struct sec
*cache_pc_function_section
= NULL
;
690 /* Clear cache, e.g. when symbol table is discarded. */
693 clear_pc_function_cache (void)
695 cache_pc_function_low
= 0;
696 cache_pc_function_high
= 0;
697 cache_pc_function_name
= (char *) 0;
698 cache_pc_function_section
= NULL
;
701 /* Finds the "function" (text symbol) that is smaller than PC but
702 greatest of all of the potential text symbols in SECTION. Sets
703 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
704 If ENDADDR is non-null, then set *ENDADDR to be the end of the
705 function (exclusive), but passing ENDADDR as non-null means that
706 the function might cause symbols to be read. This function either
707 succeeds or fails (not halfway succeeds). If it succeeds, it sets
708 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
709 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
713 find_pc_sect_partial_function (CORE_ADDR pc
, asection
*section
, char **name
,
714 CORE_ADDR
*address
, CORE_ADDR
*endaddr
)
716 struct partial_symtab
*pst
;
718 struct minimal_symbol
*msymbol
;
719 struct partial_symbol
*psb
;
720 struct obj_section
*osect
;
724 mapped_pc
= overlay_mapped_address (pc
, section
);
726 if (mapped_pc
>= cache_pc_function_low
&&
727 mapped_pc
< cache_pc_function_high
&&
728 section
== cache_pc_function_section
)
729 goto return_cached_value
;
731 /* If sigtramp is in the u area, it counts as a function (especially
732 important for step_1). */
733 #if defined SIGTRAMP_START
734 if (IN_SIGTRAMP (mapped_pc
, (char *) NULL
))
736 cache_pc_function_low
= SIGTRAMP_START (mapped_pc
);
737 cache_pc_function_high
= SIGTRAMP_END (mapped_pc
);
738 cache_pc_function_name
= "<sigtramp>";
739 cache_pc_function_section
= section
;
740 goto return_cached_value
;
744 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
745 pst
= find_pc_sect_psymtab (mapped_pc
, section
);
748 /* Need to read the symbols to get a good value for the end address. */
749 if (endaddr
!= NULL
&& !pst
->readin
)
751 /* Need to get the terminal in case symbol-reading produces
753 target_terminal_ours_for_output ();
754 PSYMTAB_TO_SYMTAB (pst
);
759 /* Checking whether the msymbol has a larger value is for the
760 "pathological" case mentioned in print_frame_info. */
761 f
= find_pc_sect_function (mapped_pc
, section
);
764 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
765 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
767 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
768 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
769 cache_pc_function_name
= SYMBOL_NAME (f
);
770 cache_pc_function_section
= section
;
771 goto return_cached_value
;
776 /* Now that static symbols go in the minimal symbol table, perhaps
777 we could just ignore the partial symbols. But at least for now
778 we use the partial or minimal symbol, whichever is larger. */
779 psb
= find_pc_sect_psymbol (pst
, mapped_pc
, section
);
782 && (msymbol
== NULL
||
783 (SYMBOL_VALUE_ADDRESS (psb
)
784 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
786 /* This case isn't being cached currently. */
788 *address
= SYMBOL_VALUE_ADDRESS (psb
);
790 *name
= SYMBOL_NAME (psb
);
791 /* endaddr non-NULL can't happen here. */
797 /* Not in the normal symbol tables, see if the pc is in a known section.
798 If it's not, then give up. This ensures that anything beyond the end
799 of the text seg doesn't appear to be part of the last function in the
802 osect
= find_pc_sect_section (mapped_pc
, section
);
807 /* Must be in the minimal symbol table. */
810 /* No available symbol. */
820 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
821 cache_pc_function_name
= SYMBOL_NAME (msymbol
);
822 cache_pc_function_section
= section
;
824 /* Use the lesser of the next minimal symbol in the same section, or
825 the end of the section, as the end of the function. */
827 /* Step over other symbols at this same address, and symbols in
828 other sections, to find the next symbol in this section with
829 a different address. */
831 for (i
= 1; SYMBOL_NAME (msymbol
+ i
) != NULL
; i
++)
833 if (SYMBOL_VALUE_ADDRESS (msymbol
+ i
) != SYMBOL_VALUE_ADDRESS (msymbol
)
834 && SYMBOL_BFD_SECTION (msymbol
+ i
) == SYMBOL_BFD_SECTION (msymbol
))
838 if (SYMBOL_NAME (msymbol
+ i
) != NULL
839 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
) < osect
->endaddr
)
840 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
842 /* We got the start address from the last msymbol in the objfile.
843 So the end address is the end of the section. */
844 cache_pc_function_high
= osect
->endaddr
;
850 if (pc_in_unmapped_range (pc
, section
))
851 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
853 *address
= cache_pc_function_low
;
857 *name
= cache_pc_function_name
;
861 if (pc_in_unmapped_range (pc
, section
))
863 /* Because the high address is actually beyond the end of
864 the function (and therefore possibly beyond the end of
865 the overlay), we must actually convert (high - 1)
866 and then add one to that. */
868 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
872 *endaddr
= cache_pc_function_high
;
878 /* Backward compatibility, no section argument */
881 find_pc_partial_function (CORE_ADDR pc
, char **name
, CORE_ADDR
*address
,
886 section
= find_pc_overlay (pc
);
887 return find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
);
890 /* Return the innermost stack frame executing inside of BLOCK,
891 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
894 block_innermost_frame (struct block
*block
)
896 struct frame_info
*frame
;
897 register CORE_ADDR start
;
898 register CORE_ADDR end
;
903 start
= BLOCK_START (block
);
904 end
= BLOCK_END (block
);
909 frame
= get_prev_frame (frame
);
912 if (frame
->pc
>= start
&& frame
->pc
< end
)
917 /* Return the full FRAME which corresponds to the given CORE_ADDR
918 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
921 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr
)
923 struct frame_info
*frame
= NULL
;
925 if (frame_addr
== (CORE_ADDR
) 0)
930 frame
= get_prev_frame (frame
);
933 if (FRAME_FP (frame
) == frame_addr
)
938 #ifdef SIGCONTEXT_PC_OFFSET
939 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
942 sigtramp_saved_pc (struct frame_info
*frame
)
944 CORE_ADDR sigcontext_addr
;
946 int ptrbytes
= TARGET_PTR_BIT
/ TARGET_CHAR_BIT
;
947 int sigcontext_offs
= (2 * TARGET_INT_BIT
) / TARGET_CHAR_BIT
;
949 buf
= alloca (ptrbytes
);
950 /* Get sigcontext address, it is the third parameter on the stack. */
952 sigcontext_addr
= read_memory_integer (FRAME_ARGS_ADDRESS (frame
->next
)
957 sigcontext_addr
= read_memory_integer (read_register (SP_REGNUM
)
961 /* Don't cause a memory_error when accessing sigcontext in case the stack
962 layout has changed or the stack is corrupt. */
963 target_read_memory (sigcontext_addr
+ SIGCONTEXT_PC_OFFSET
, buf
, ptrbytes
);
964 return extract_unsigned_integer (buf
, ptrbytes
);
966 #endif /* SIGCONTEXT_PC_OFFSET */
969 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
970 below is for infrun.c, which may give the macro a pc without that
973 extern CORE_ADDR text_end
;
976 pc_in_call_dummy_before_text_end (CORE_ADDR pc
, CORE_ADDR sp
,
977 CORE_ADDR frame_address
)
979 return ((pc
) >= text_end
- CALL_DUMMY_LENGTH
980 && (pc
) <= text_end
+ DECR_PC_AFTER_BREAK
);
984 pc_in_call_dummy_after_text_end (CORE_ADDR pc
, CORE_ADDR sp
,
985 CORE_ADDR frame_address
)
987 return ((pc
) >= text_end
988 && (pc
) <= text_end
+ CALL_DUMMY_LENGTH
+ DECR_PC_AFTER_BREAK
);
991 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
992 top of the stack frame which we are checking, where "bottom" and
993 "top" refer to some section of memory which contains the code for
994 the call dummy. Calls to this macro assume that the contents of
995 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
996 are the things to pass.
998 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
999 have that meaning, but the 29k doesn't use ON_STACK. This could be
1000 fixed by generalizing this scheme, perhaps by passing in a frame
1001 and adding a few fields, at least on machines which need them for
1004 Something simpler, like checking for the stack segment, doesn't work,
1005 since various programs (threads implementations, gcc nested function
1006 stubs, etc) may either allocate stack frames in another segment, or
1007 allocate other kinds of code on the stack. */
1010 pc_in_call_dummy_on_stack (CORE_ADDR pc
, CORE_ADDR sp
, CORE_ADDR frame_address
)
1012 return (INNER_THAN ((sp
), (pc
))
1013 && (frame_address
!= 0)
1014 && INNER_THAN ((pc
), (frame_address
)));
1018 pc_in_call_dummy_at_entry_point (CORE_ADDR pc
, CORE_ADDR sp
,
1019 CORE_ADDR frame_address
)
1021 return ((pc
) >= CALL_DUMMY_ADDRESS ()
1022 && (pc
) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK
));
1027 * GENERIC DUMMY FRAMES
1029 * The following code serves to maintain the dummy stack frames for
1030 * inferior function calls (ie. when gdb calls into the inferior via
1031 * call_function_by_hand). This code saves the machine state before
1032 * the call in host memory, so we must maintain an independent stack
1033 * and keep it consistant etc. I am attempting to make this code
1034 * generic enough to be used by many targets.
1036 * The cheapest and most generic way to do CALL_DUMMY on a new target
1037 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1038 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1039 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1040 * being executed by the target. Also FRAME_CHAIN_VALID as
1041 * generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
1042 * generic_fix_call_dummy. */
1044 /* Dummy frame. This saves the processor state just prior to setting
1045 up the inferior function call. Older targets save the registers
1046 on the target stack (but that really slows down function calls). */
1050 struct dummy_frame
*next
;
1059 static struct dummy_frame
*dummy_frame_stack
= NULL
;
1061 /* Function: find_dummy_frame(pc, fp, sp)
1062 Search the stack of dummy frames for one matching the given PC, FP and SP.
1063 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1066 generic_find_dummy_frame (CORE_ADDR pc
, CORE_ADDR fp
)
1068 struct dummy_frame
*dummyframe
;
1070 if (pc
!= entry_point_address ())
1073 for (dummyframe
= dummy_frame_stack
; dummyframe
!= NULL
;
1074 dummyframe
= dummyframe
->next
)
1075 if (fp
== dummyframe
->fp
1076 || fp
== dummyframe
->sp
1077 || fp
== dummyframe
->top
)
1078 /* The frame in question lies between the saved fp and sp, inclusive */
1079 return dummyframe
->registers
;
1084 /* Function: pc_in_call_dummy (pc, fp)
1085 Return true if this is a dummy frame created by gdb for an inferior call */
1088 generic_pc_in_call_dummy (CORE_ADDR pc
, CORE_ADDR sp
, CORE_ADDR fp
)
1090 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1091 /* Note: SP and not FP is passed on. */
1092 return (generic_find_dummy_frame (pc
, sp
) != 0);
1095 /* Function: read_register_dummy
1096 Find a saved register from before GDB calls a function in the inferior */
1099 generic_read_register_dummy (CORE_ADDR pc
, CORE_ADDR fp
, int regno
)
1101 char *dummy_regs
= generic_find_dummy_frame (pc
, fp
);
1104 return extract_address (&dummy_regs
[REGISTER_BYTE (regno
)],
1105 REGISTER_RAW_SIZE (regno
));
1110 /* Save all the registers on the dummy frame stack. Most ports save the
1111 registers on the target stack. This results in lots of unnecessary memory
1112 references, which are slow when debugging via a serial line. Instead, we
1113 save all the registers internally, and never write them to the stack. The
1114 registers get restored when the called function returns to the entry point,
1115 where a breakpoint is laying in wait. */
1118 generic_push_dummy_frame (void)
1120 struct dummy_frame
*dummy_frame
;
1121 CORE_ADDR fp
= (get_current_frame ())->frame
;
1123 /* check to see if there are stale dummy frames,
1124 perhaps left over from when a longjump took us out of a
1125 function that was called by the debugger */
1127 dummy_frame
= dummy_frame_stack
;
1129 if (INNER_THAN (dummy_frame
->fp
, fp
)) /* stale -- destroy! */
1131 dummy_frame_stack
= dummy_frame
->next
;
1132 xfree (dummy_frame
->registers
);
1133 xfree (dummy_frame
);
1134 dummy_frame
= dummy_frame_stack
;
1137 dummy_frame
= dummy_frame
->next
;
1139 dummy_frame
= xmalloc (sizeof (struct dummy_frame
));
1140 dummy_frame
->registers
= xmalloc (REGISTER_BYTES
);
1142 dummy_frame
->pc
= read_pc ();
1143 dummy_frame
->sp
= read_sp ();
1144 dummy_frame
->top
= dummy_frame
->sp
;
1145 dummy_frame
->fp
= fp
;
1146 read_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1147 dummy_frame
->next
= dummy_frame_stack
;
1148 dummy_frame_stack
= dummy_frame
;
1152 generic_save_dummy_frame_tos (CORE_ADDR sp
)
1154 dummy_frame_stack
->top
= sp
;
1157 /* Restore the machine state from either the saved dummy stack or a
1158 real stack frame. */
1161 generic_pop_current_frame (void (*popper
) (struct frame_info
* frame
))
1163 struct frame_info
*frame
= get_current_frame ();
1165 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1166 generic_pop_dummy_frame ();
1171 /* Function: pop_dummy_frame
1172 Restore the machine state from a saved dummy stack frame. */
1175 generic_pop_dummy_frame (void)
1177 struct dummy_frame
*dummy_frame
= dummy_frame_stack
;
1179 /* FIXME: what if the first frame isn't the right one, eg..
1180 because one call-by-hand function has done a longjmp into another one? */
1183 error ("Can't pop dummy frame!");
1184 dummy_frame_stack
= dummy_frame
->next
;
1185 write_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1186 flush_cached_frames ();
1188 xfree (dummy_frame
->registers
);
1189 xfree (dummy_frame
);
1192 /* Function: frame_chain_valid
1193 Returns true for a user frame or a call_function_by_hand dummy frame,
1194 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1197 generic_file_frame_chain_valid (CORE_ADDR fp
, struct frame_info
*fi
)
1199 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi
), fp
, fp
))
1200 return 1; /* don't prune CALL_DUMMY frames */
1201 else /* fall back to default algorithm (see frame.h) */
1203 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1204 && !inside_entry_file (FRAME_SAVED_PC (fi
)));
1208 generic_func_frame_chain_valid (CORE_ADDR fp
, struct frame_info
*fi
)
1210 if (PC_IN_CALL_DUMMY ((fi
)->pc
, fp
, fp
))
1211 return 1; /* don't prune CALL_DUMMY frames */
1212 else /* fall back to default algorithm (see frame.h) */
1214 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1215 && !inside_main_func ((fi
)->pc
)
1216 && !inside_entry_func ((fi
)->pc
));
1219 /* Function: fix_call_dummy
1220 Stub function. Generic dumy frames typically do not need to fix
1221 the frame being created */
1224 generic_fix_call_dummy (char *dummy
, CORE_ADDR pc
, CORE_ADDR fun
, int nargs
,
1225 struct value
**args
, struct type
*type
, int gcc_p
)
1230 /* Function: get_saved_register
1231 Find register number REGNUM relative to FRAME and put its (raw,
1232 target format) contents in *RAW_BUFFER.
1234 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1235 fetched). Note that this is never set to anything other than zero
1236 in this implementation.
1238 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1239 whether the value was fetched from memory, from a register, or in a
1240 strange and non-modifiable way (e.g. a frame pointer which was
1241 calculated rather than fetched). We will use not_lval for values
1242 fetched from generic dummy frames.
1244 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
1245 offset into the registers array. If the value is stored in a dummy
1246 frame, set *ADDRP to zero.
1248 To use this implementation, define a function called
1249 "get_saved_register" in your target code, which simply passes all
1250 of its arguments to this function.
1252 The argument RAW_BUFFER must point to aligned memory. */
1255 generic_get_saved_register (char *raw_buffer
, int *optimized
, CORE_ADDR
*addrp
,
1256 struct frame_info
*frame
, int regnum
,
1257 enum lval_type
*lval
)
1259 if (!target_has_registers
)
1260 error ("No registers.");
1262 /* Normal systems don't optimize out things with register numbers. */
1263 if (optimized
!= NULL
)
1266 if (addrp
) /* default assumption: not found in memory */
1269 /* Note: since the current frame's registers could only have been
1270 saved by frames INTERIOR TO the current frame, we skip examining
1271 the current frame itself: otherwise, we would be getting the
1272 previous frame's registers which were saved by the current frame. */
1274 while (frame
&& ((frame
= frame
->next
) != NULL
))
1276 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1278 if (lval
) /* found it in a CALL_DUMMY frame */
1282 generic_find_dummy_frame (frame
->pc
, frame
->frame
) +
1283 REGISTER_BYTE (regnum
),
1284 REGISTER_RAW_SIZE (regnum
));
1288 FRAME_INIT_SAVED_REGS (frame
);
1289 if (frame
->saved_regs
!= NULL
1290 && frame
->saved_regs
[regnum
] != 0)
1292 if (lval
) /* found it saved on the stack */
1293 *lval
= lval_memory
;
1294 if (regnum
== SP_REGNUM
)
1296 if (raw_buffer
) /* SP register treated specially */
1297 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
1298 frame
->saved_regs
[regnum
]);
1302 if (addrp
) /* any other register */
1303 *addrp
= frame
->saved_regs
[regnum
];
1305 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
1306 REGISTER_RAW_SIZE (regnum
));
1312 /* If we get thru the loop to this point, it means the register was
1313 not saved in any frame. Return the actual live-register value. */
1315 if (lval
) /* found it in a live register */
1316 *lval
= lval_register
;
1318 *addrp
= REGISTER_BYTE (regnum
);
1320 read_register_gen (regnum
, raw_buffer
);
1324 _initialize_blockframe (void)
1326 obstack_init (&frame_cache_obstack
);