1 /* Get info from stack frames;
2 convert between frames, blocks, functions and pc values.
3 Copyright 1986, 87, 88, 89, 91, 94, 95, 96, 97, 1998
4 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 */
35 /* Prototypes for exported functions. */
37 void _initialize_blockframe (void);
39 /* A default FRAME_CHAIN_VALID, in the form that is suitable for most
40 targets. If FRAME_CHAIN_VALID returns zero it means that the given
41 frame is the outermost one and has no caller. */
44 file_frame_chain_valid (chain
, thisframe
)
46 struct frame_info
*thisframe
;
49 && !inside_entry_file (FRAME_SAVED_PC (thisframe
)));
52 /* Use the alternate method of avoiding running up off the end of the
53 frame chain or following frames back into the startup code. See
54 the comments in objfiles.h. */
57 func_frame_chain_valid (chain
, thisframe
)
59 struct frame_info
*thisframe
;
62 && !inside_main_func ((thisframe
)->pc
)
63 && !inside_entry_func ((thisframe
)->pc
));
66 /* A very simple method of determining a valid frame */
69 nonnull_frame_chain_valid (chain
, thisframe
)
71 struct frame_info
*thisframe
;
73 return ((chain
) != 0);
76 /* Is ADDR inside the startup file? Note that if your machine
77 has a way to detect the bottom of the stack, there is no need
78 to call this function from FRAME_CHAIN_VALID; the reason for
79 doing so is that some machines have no way of detecting bottom
82 A PC of zero is always considered to be the bottom of the stack. */
85 inside_entry_file (addr
)
90 if (symfile_objfile
== 0)
92 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
94 /* Do not stop backtracing if the pc is in the call dummy
95 at the entry point. */
96 /* FIXME: Won't always work with zeros for the last two arguments */
97 if (PC_IN_CALL_DUMMY (addr
, 0, 0))
100 return (addr
>= symfile_objfile
->ei
.entry_file_lowpc
&&
101 addr
< symfile_objfile
->ei
.entry_file_highpc
);
104 /* Test a specified PC value to see if it is in the range of addresses
105 that correspond to the main() function. See comments above for why
106 we might want to do this.
108 Typically called from FRAME_CHAIN_VALID.
110 A PC of zero is always considered to be the bottom of the stack. */
113 inside_main_func (pc
)
118 if (symfile_objfile
== 0)
121 /* If the addr range is not set up at symbol reading time, set it up now.
122 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
123 it is unable to set it up and symbol reading time. */
125 if (symfile_objfile
->ei
.main_func_lowpc
== INVALID_ENTRY_LOWPC
&&
126 symfile_objfile
->ei
.main_func_highpc
== INVALID_ENTRY_HIGHPC
)
128 struct symbol
*mainsym
;
130 mainsym
= lookup_symbol ("main", NULL
, VAR_NAMESPACE
, NULL
, NULL
);
131 if (mainsym
&& SYMBOL_CLASS (mainsym
) == LOC_BLOCK
)
133 symfile_objfile
->ei
.main_func_lowpc
=
134 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym
));
135 symfile_objfile
->ei
.main_func_highpc
=
136 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym
));
139 return (symfile_objfile
->ei
.main_func_lowpc
<= pc
&&
140 symfile_objfile
->ei
.main_func_highpc
> pc
);
143 /* Test a specified PC value to see if it is in the range of addresses
144 that correspond to the process entry point function. See comments
145 in objfiles.h for why we might want to do this.
147 Typically called from FRAME_CHAIN_VALID.
149 A PC of zero is always considered to be the bottom of the stack. */
152 inside_entry_func (pc
)
157 if (symfile_objfile
== 0)
159 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
161 /* Do not stop backtracing if the pc is in the call dummy
162 at the entry point. */
163 /* FIXME: Won't always work with zeros for the last two arguments */
164 if (PC_IN_CALL_DUMMY (pc
, 0, 0))
167 return (symfile_objfile
->ei
.entry_func_lowpc
<= pc
&&
168 symfile_objfile
->ei
.entry_func_highpc
> pc
);
171 /* Info about the innermost stack frame (contents of FP register) */
173 static struct frame_info
*current_frame
;
175 /* Cache for frame addresses already read by gdb. Valid only while
176 inferior is stopped. Control variables for the frame cache should
177 be local to this module. */
179 static struct obstack frame_cache_obstack
;
182 frame_obstack_alloc (size
)
185 return obstack_alloc (&frame_cache_obstack
, size
);
189 frame_saved_regs_zalloc (fi
)
190 struct frame_info
*fi
;
192 fi
->saved_regs
= (CORE_ADDR
*)
193 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
194 memset (fi
->saved_regs
, 0, SIZEOF_FRAME_SAVED_REGS
);
198 /* Return the innermost (currently executing) stack frame. */
203 if (current_frame
== NULL
)
205 if (target_has_stack
)
206 current_frame
= create_new_frame (read_fp (), read_pc ());
210 return current_frame
;
214 set_current_frame (frame
)
215 struct frame_info
*frame
;
217 current_frame
= frame
;
220 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
221 Always returns a non-NULL value. */
224 create_new_frame (addr
, pc
)
228 struct frame_info
*fi
;
231 fi
= (struct frame_info
*)
232 obstack_alloc (&frame_cache_obstack
,
233 sizeof (struct frame_info
));
235 /* Arbitrary frame */
236 fi
->saved_regs
= NULL
;
241 find_pc_partial_function (pc
, &name
, (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
242 fi
->signal_handler_caller
= IN_SIGTRAMP (fi
->pc
, name
);
244 #ifdef INIT_EXTRA_FRAME_INFO
245 INIT_EXTRA_FRAME_INFO (0, fi
);
251 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
255 get_next_frame (frame
)
256 struct frame_info
*frame
;
261 /* Flush the entire frame cache. */
264 flush_cached_frames ()
266 /* Since we can't really be sure what the first object allocated was */
267 obstack_free (&frame_cache_obstack
, 0);
268 obstack_init (&frame_cache_obstack
);
270 current_frame
= NULL
; /* Invalidate cache */
271 select_frame (NULL
, -1);
272 annotate_frames_invalid ();
275 /* Flush the frame cache, and start a new one if necessary. */
278 reinit_frame_cache ()
280 flush_cached_frames ();
282 /* FIXME: The inferior_pid test is wrong if there is a corefile. */
283 if (inferior_pid
!= 0)
285 select_frame (get_current_frame (), 0);
289 /* Return nonzero if the function for this frame lacks a prologue. Many
290 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
294 frameless_look_for_prologue (frame
)
295 struct frame_info
*frame
;
297 CORE_ADDR func_start
, after_prologue
;
299 func_start
= get_pc_function_start (frame
->pc
);
302 func_start
+= FUNCTION_START_OFFSET
;
303 /* This is faster, since only care whether there *is* a
304 prologue, not how long it is. */
305 return PROLOGUE_FRAMELESS_P (func_start
);
307 else if (frame
->pc
== 0)
308 /* A frame with a zero PC is usually created by dereferencing a
309 NULL function pointer, normally causing an immediate core dump
310 of the inferior. Mark function as frameless, as the inferior
311 has no chance of setting up a stack frame. */
314 /* If we can't find the start of the function, we don't really
315 know whether the function is frameless, but we should be able
316 to get a reasonable (i.e. best we can do under the
317 circumstances) backtrace by saying that it isn't. */
321 /* Default a few macros that people seldom redefine. */
323 #if !defined (INIT_FRAME_PC)
324 #define INIT_FRAME_PC(fromleaf, prev) \
325 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
326 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
329 #ifndef FRAME_CHAIN_COMBINE
330 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
333 /* Return a structure containing various interesting information
334 about the frame that called NEXT_FRAME. Returns NULL
335 if there is no such frame. */
338 get_prev_frame (next_frame
)
339 struct frame_info
*next_frame
;
341 CORE_ADDR address
= 0;
342 struct frame_info
*prev
;
346 /* If the requested entry is in the cache, return it.
347 Otherwise, figure out what the address should be for the entry
348 we're about to add to the cache. */
353 /* This screws value_of_variable, which just wants a nice clean
354 NULL return from block_innermost_frame if there are no frames.
355 I don't think I've ever seen this message happen otherwise.
356 And returning NULL here is a perfectly legitimate thing to do. */
359 error ("You haven't set up a process's stack to examine.");
363 return current_frame
;
366 /* If we have the prev one, return it */
367 if (next_frame
->prev
)
368 return next_frame
->prev
;
370 /* On some machines it is possible to call a function without
371 setting up a stack frame for it. On these machines, we
372 define this macro to take two args; a frameinfo pointer
373 identifying a frame and a variable to set or clear if it is
374 or isn't leafless. */
376 /* Still don't want to worry about this except on the innermost
377 frame. This macro will set FROMLEAF if NEXT_FRAME is a
378 frameless function invocation. */
379 if (!(next_frame
->next
))
381 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
383 address
= FRAME_FP (next_frame
);
388 /* Two macros defined in tm.h specify the machine-dependent
389 actions to be performed here.
390 First, get the frame's chain-pointer.
391 If that is zero, the frame is the outermost frame or a leaf
392 called by the outermost frame. This means that if start
393 calls main without a frame, we'll return 0 (which is fine
396 Nope; there's a problem. This also returns when the current
397 routine is a leaf of main. This is unacceptable. We move
398 this to after the ffi test; I'd rather have backtraces from
399 start go curfluy than have an abort called from main not show
401 address
= FRAME_CHAIN (next_frame
);
402 if (!FRAME_CHAIN_VALID (address
, next_frame
))
404 address
= FRAME_CHAIN_COMBINE (address
, next_frame
);
409 prev
= (struct frame_info
*)
410 obstack_alloc (&frame_cache_obstack
,
411 sizeof (struct frame_info
));
413 prev
->saved_regs
= NULL
;
415 next_frame
->prev
= prev
;
416 prev
->next
= next_frame
;
417 prev
->prev
= (struct frame_info
*) 0;
418 prev
->frame
= address
;
419 prev
->signal_handler_caller
= 0;
421 /* This change should not be needed, FIXME! We should
422 determine whether any targets *need* INIT_FRAME_PC to happen
423 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
424 express what goes on here.
426 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
427 (where the PC is already set up) and here (where it isn't).
428 INIT_FRAME_PC is only called from here, always after
429 INIT_EXTRA_FRAME_INFO.
431 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
432 value (which hasn't been set yet). Some other machines appear to
433 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
435 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
436 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
438 Assuming that some machines need INIT_FRAME_PC after
439 INIT_EXTRA_FRAME_INFO, one possible scheme:
441 SETUP_INNERMOST_FRAME()
442 Default version is just create_new_frame (read_fp ()),
443 read_pc ()). Machines with extra frame info would do that (or the
444 local equivalent) and then set the extra fields.
445 SETUP_ARBITRARY_FRAME(argc, argv)
446 Only change here is that create_new_frame would no longer init extra
447 frame info; SETUP_ARBITRARY_FRAME would have to do that.
448 INIT_PREV_FRAME(fromleaf, prev)
449 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
450 also return a flag saying whether to keep the new frame, or
451 whether to discard it, because on some machines (e.g. mips) it
452 is really awkward to have FRAME_CHAIN_VALID called *before*
453 INIT_EXTRA_FRAME_INFO (there is no good way to get information
454 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
455 std_frame_pc(fromleaf, prev)
456 This is the default setting for INIT_PREV_FRAME. It just does what
457 the default INIT_FRAME_PC does. Some machines will call it from
458 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
459 Some machines won't use it.
460 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
462 #ifdef INIT_FRAME_PC_FIRST
463 INIT_FRAME_PC_FIRST (fromleaf
, prev
);
466 #ifdef INIT_EXTRA_FRAME_INFO
467 INIT_EXTRA_FRAME_INFO (fromleaf
, prev
);
470 /* This entry is in the frame queue now, which is good since
471 FRAME_SAVED_PC may use that queue to figure out its value
472 (see tm-sparc.h). We want the pc saved in the inferior frame. */
473 INIT_FRAME_PC (fromleaf
, prev
);
475 /* If ->frame and ->pc are unchanged, we are in the process of getting
476 ourselves into an infinite backtrace. Some architectures check this
477 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
478 this can't be an architecture-independent check. */
479 if (next_frame
!= NULL
)
481 if (prev
->frame
== next_frame
->frame
482 && prev
->pc
== next_frame
->pc
)
484 next_frame
->prev
= NULL
;
485 obstack_free (&frame_cache_obstack
, prev
);
490 find_pc_partial_function (prev
->pc
, &name
,
491 (CORE_ADDR
*) NULL
, (CORE_ADDR
*) NULL
);
492 if (IN_SIGTRAMP (prev
->pc
, name
))
493 prev
->signal_handler_caller
= 1;
500 struct frame_info
*frame
;
506 #ifdef FRAME_FIND_SAVED_REGS
507 /* XXX - deprecated. This is a compatibility function for targets
508 that do not yet implement FRAME_INIT_SAVED_REGS. */
509 /* Find the addresses in which registers are saved in FRAME. */
512 get_frame_saved_regs (frame
, saved_regs_addr
)
513 struct frame_info
*frame
;
514 struct frame_saved_regs
*saved_regs_addr
;
516 if (frame
->saved_regs
== NULL
)
518 frame
->saved_regs
= (CORE_ADDR
*)
519 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
521 if (saved_regs_addr
== NULL
)
523 struct frame_saved_regs saved_regs
;
524 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
525 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
529 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
530 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
535 /* Return the innermost lexical block in execution
536 in a specified stack frame. The frame address is assumed valid. */
539 get_frame_block (frame
)
540 struct frame_info
*frame
;
545 if (frame
->next
!= 0 && frame
->next
->signal_handler_caller
== 0)
546 /* We are not in the innermost frame and we were not interrupted
547 by a signal. We need to subtract one to get the correct block,
548 in case the call instruction was the last instruction of the block.
549 If there are any machines on which the saved pc does not point to
550 after the call insn, we probably want to make frame->pc point after
551 the call insn anyway. */
553 return block_for_pc (pc
);
559 return block_for_pc (read_pc ());
563 get_pc_function_start (pc
)
566 register struct block
*bl
;
567 register struct symbol
*symbol
;
568 register struct minimal_symbol
*msymbol
;
571 if ((bl
= block_for_pc (pc
)) != NULL
&&
572 (symbol
= block_function (bl
)) != NULL
)
574 bl
= SYMBOL_BLOCK_VALUE (symbol
);
575 fstart
= BLOCK_START (bl
);
577 else if ((msymbol
= lookup_minimal_symbol_by_pc (pc
)) != NULL
)
579 fstart
= SYMBOL_VALUE_ADDRESS (msymbol
);
588 /* Return the symbol for the function executing in frame FRAME. */
591 get_frame_function (frame
)
592 struct frame_info
*frame
;
594 register struct block
*bl
= get_frame_block (frame
);
597 return block_function (bl
);
601 /* Return the blockvector immediately containing the innermost lexical block
602 containing the specified pc value and section, or 0 if there is none.
603 PINDEX is a pointer to the index value of the block. If PINDEX
604 is NULL, we don't pass this information back to the caller. */
607 blockvector_for_pc_sect (pc
, section
, pindex
, symtab
)
608 register CORE_ADDR pc
;
611 struct symtab
*symtab
;
614 register struct block
*b
;
615 register int bot
, top
, half
;
616 struct blockvector
*bl
;
618 if (symtab
== 0) /* if no symtab specified by caller */
620 /* First search all symtabs for one whose file contains our pc */
621 if ((symtab
= find_pc_sect_symtab (pc
, section
)) == 0)
625 bl
= BLOCKVECTOR (symtab
);
626 b
= BLOCKVECTOR_BLOCK (bl
, 0);
628 /* Then search that symtab for the smallest block that wins. */
629 /* Use binary search to find the last block that starts before PC. */
632 top
= BLOCKVECTOR_NBLOCKS (bl
);
634 while (top
- bot
> 1)
636 half
= (top
- bot
+ 1) >> 1;
637 b
= BLOCKVECTOR_BLOCK (bl
, bot
+ half
);
638 if (BLOCK_START (b
) <= pc
)
644 /* Now search backward for a block that ends after PC. */
648 b
= BLOCKVECTOR_BLOCK (bl
, bot
);
649 if (BLOCK_END (b
) > pc
)
660 /* Return the blockvector immediately containing the innermost lexical block
661 containing the specified pc value, or 0 if there is none.
662 Backward compatibility, no section. */
665 blockvector_for_pc (pc
, pindex
)
666 register CORE_ADDR pc
;
669 return blockvector_for_pc_sect (pc
, find_pc_mapped_section (pc
),
673 /* Return the innermost lexical block containing the specified pc value
674 in the specified section, or 0 if there is none. */
677 block_for_pc_sect (pc
, section
)
678 register CORE_ADDR pc
;
681 register struct blockvector
*bl
;
684 bl
= blockvector_for_pc_sect (pc
, section
, &index
, NULL
);
686 return BLOCKVECTOR_BLOCK (bl
, index
);
690 /* Return the innermost lexical block containing the specified pc value,
691 or 0 if there is none. Backward compatibility, no section. */
695 register CORE_ADDR pc
;
697 return block_for_pc_sect (pc
, find_pc_mapped_section (pc
));
700 /* Return the function containing pc value PC in section SECTION.
701 Returns 0 if function is not known. */
704 find_pc_sect_function (pc
, section
)
708 register struct block
*b
= block_for_pc_sect (pc
, section
);
711 return block_function (b
);
714 /* Return the function containing pc value PC.
715 Returns 0 if function is not known. Backward compatibility, no section */
718 find_pc_function (pc
)
721 return find_pc_sect_function (pc
, find_pc_mapped_section (pc
));
724 /* These variables are used to cache the most recent result
725 * of find_pc_partial_function. */
727 static CORE_ADDR cache_pc_function_low
= 0;
728 static CORE_ADDR cache_pc_function_high
= 0;
729 static char *cache_pc_function_name
= 0;
730 static struct sec
*cache_pc_function_section
= NULL
;
732 /* Clear cache, e.g. when symbol table is discarded. */
735 clear_pc_function_cache ()
737 cache_pc_function_low
= 0;
738 cache_pc_function_high
= 0;
739 cache_pc_function_name
= (char *) 0;
740 cache_pc_function_section
= NULL
;
743 /* Finds the "function" (text symbol) that is smaller than PC but
744 greatest of all of the potential text symbols in SECTION. Sets
745 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
746 If ENDADDR is non-null, then set *ENDADDR to be the end of the
747 function (exclusive), but passing ENDADDR as non-null means that
748 the function might cause symbols to be read. This function either
749 succeeds or fails (not halfway succeeds). If it succeeds, it sets
750 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
751 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
755 find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
)
762 struct partial_symtab
*pst
;
764 struct minimal_symbol
*msymbol
;
765 struct partial_symbol
*psb
;
766 struct obj_section
*osect
;
770 mapped_pc
= overlay_mapped_address (pc
, section
);
772 if (mapped_pc
>= cache_pc_function_low
&&
773 mapped_pc
< cache_pc_function_high
&&
774 section
== cache_pc_function_section
)
775 goto return_cached_value
;
777 /* If sigtramp is in the u area, it counts as a function (especially
778 important for step_1). */
779 #if defined SIGTRAMP_START
780 if (IN_SIGTRAMP (mapped_pc
, (char *) NULL
))
782 cache_pc_function_low
= SIGTRAMP_START (mapped_pc
);
783 cache_pc_function_high
= SIGTRAMP_END (mapped_pc
);
784 cache_pc_function_name
= "<sigtramp>";
785 cache_pc_function_section
= section
;
786 goto return_cached_value
;
790 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
791 pst
= find_pc_sect_psymtab (mapped_pc
, section
);
794 /* Need to read the symbols to get a good value for the end address. */
795 if (endaddr
!= NULL
&& !pst
->readin
)
797 /* Need to get the terminal in case symbol-reading produces
799 target_terminal_ours_for_output ();
800 PSYMTAB_TO_SYMTAB (pst
);
805 /* Checking whether the msymbol has a larger value is for the
806 "pathological" case mentioned in print_frame_info. */
807 f
= find_pc_sect_function (mapped_pc
, section
);
810 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
811 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
813 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
814 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
815 cache_pc_function_name
= SYMBOL_NAME (f
);
816 cache_pc_function_section
= section
;
817 goto return_cached_value
;
822 /* Now that static symbols go in the minimal symbol table, perhaps
823 we could just ignore the partial symbols. But at least for now
824 we use the partial or minimal symbol, whichever is larger. */
825 psb
= find_pc_sect_psymbol (pst
, mapped_pc
, section
);
828 && (msymbol
== NULL
||
829 (SYMBOL_VALUE_ADDRESS (psb
)
830 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
832 /* This case isn't being cached currently. */
834 *address
= SYMBOL_VALUE_ADDRESS (psb
);
836 *name
= SYMBOL_NAME (psb
);
837 /* endaddr non-NULL can't happen here. */
843 /* Not in the normal symbol tables, see if the pc is in a known section.
844 If it's not, then give up. This ensures that anything beyond the end
845 of the text seg doesn't appear to be part of the last function in the
848 osect
= find_pc_sect_section (mapped_pc
, section
);
853 /* Must be in the minimal symbol table. */
856 /* No available symbol. */
866 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
867 cache_pc_function_name
= SYMBOL_NAME (msymbol
);
868 cache_pc_function_section
= section
;
870 /* Use the lesser of the next minimal symbol in the same section, or
871 the end of the section, as the end of the function. */
873 /* Step over other symbols at this same address, and symbols in
874 other sections, to find the next symbol in this section with
875 a different address. */
877 for (i
= 1; SYMBOL_NAME (msymbol
+ i
) != NULL
; i
++)
879 if (SYMBOL_VALUE_ADDRESS (msymbol
+ i
) != SYMBOL_VALUE_ADDRESS (msymbol
)
880 && SYMBOL_BFD_SECTION (msymbol
+ i
) == SYMBOL_BFD_SECTION (msymbol
))
884 if (SYMBOL_NAME (msymbol
+ i
) != NULL
885 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
) < osect
->endaddr
)
886 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
888 /* We got the start address from the last msymbol in the objfile.
889 So the end address is the end of the section. */
890 cache_pc_function_high
= osect
->endaddr
;
896 if (pc_in_unmapped_range (pc
, section
))
897 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
899 *address
= cache_pc_function_low
;
903 *name
= cache_pc_function_name
;
907 if (pc_in_unmapped_range (pc
, section
))
909 /* Because the high address is actually beyond the end of
910 the function (and therefore possibly beyond the end of
911 the overlay), we must actually convert (high - 1)
912 and then add one to that. */
914 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
918 *endaddr
= cache_pc_function_high
;
924 /* Backward compatibility, no section argument */
927 find_pc_partial_function (pc
, name
, address
, endaddr
)
935 section
= find_pc_overlay (pc
);
936 return find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
);
939 /* Return the innermost stack frame executing inside of BLOCK,
940 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
943 block_innermost_frame (block
)
946 struct frame_info
*frame
;
947 register CORE_ADDR start
;
948 register CORE_ADDR end
;
953 start
= BLOCK_START (block
);
954 end
= BLOCK_END (block
);
959 frame
= get_prev_frame (frame
);
962 if (frame
->pc
>= start
&& frame
->pc
< end
)
967 /* Return the full FRAME which corresponds to the given CORE_ADDR
968 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
971 find_frame_addr_in_frame_chain (frame_addr
)
972 CORE_ADDR frame_addr
;
974 struct frame_info
*frame
= NULL
;
976 if (frame_addr
== (CORE_ADDR
) 0)
981 frame
= get_prev_frame (frame
);
984 if (FRAME_FP (frame
) == frame_addr
)
989 #ifdef SIGCONTEXT_PC_OFFSET
990 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
993 sigtramp_saved_pc (frame
)
994 struct frame_info
*frame
;
996 CORE_ADDR sigcontext_addr
;
997 char buf
[TARGET_PTR_BIT
/ TARGET_CHAR_BIT
];
998 int ptrbytes
= TARGET_PTR_BIT
/ TARGET_CHAR_BIT
;
999 int sigcontext_offs
= (2 * TARGET_INT_BIT
) / TARGET_CHAR_BIT
;
1001 /* Get sigcontext address, it is the third parameter on the stack. */
1003 sigcontext_addr
= read_memory_integer (FRAME_ARGS_ADDRESS (frame
->next
)
1008 sigcontext_addr
= read_memory_integer (read_register (SP_REGNUM
)
1012 /* Don't cause a memory_error when accessing sigcontext in case the stack
1013 layout has changed or the stack is corrupt. */
1014 target_read_memory (sigcontext_addr
+ SIGCONTEXT_PC_OFFSET
, buf
, ptrbytes
);
1015 return extract_unsigned_integer (buf
, ptrbytes
);
1017 #endif /* SIGCONTEXT_PC_OFFSET */
1020 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
1021 below is for infrun.c, which may give the macro a pc without that
1024 extern CORE_ADDR text_end
;
1027 pc_in_call_dummy_before_text_end (pc
, sp
, frame_address
)
1030 CORE_ADDR frame_address
;
1032 return ((pc
) >= text_end
- CALL_DUMMY_LENGTH
1033 && (pc
) <= text_end
+ DECR_PC_AFTER_BREAK
);
1037 pc_in_call_dummy_after_text_end (pc
, sp
, frame_address
)
1040 CORE_ADDR frame_address
;
1042 return ((pc
) >= text_end
1043 && (pc
) <= text_end
+ CALL_DUMMY_LENGTH
+ DECR_PC_AFTER_BREAK
);
1046 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1047 top of the stack frame which we are checking, where "bottom" and
1048 "top" refer to some section of memory which contains the code for
1049 the call dummy. Calls to this macro assume that the contents of
1050 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1051 are the things to pass.
1053 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1054 have that meaning, but the 29k doesn't use ON_STACK. This could be
1055 fixed by generalizing this scheme, perhaps by passing in a frame
1056 and adding a few fields, at least on machines which need them for
1059 Something simpler, like checking for the stack segment, doesn't work,
1060 since various programs (threads implementations, gcc nested function
1061 stubs, etc) may either allocate stack frames in another segment, or
1062 allocate other kinds of code on the stack. */
1065 pc_in_call_dummy_on_stack (pc
, sp
, frame_address
)
1068 CORE_ADDR frame_address
;
1070 return (INNER_THAN ((sp
), (pc
))
1071 && (frame_address
!= 0)
1072 && INNER_THAN ((pc
), (frame_address
)));
1076 pc_in_call_dummy_at_entry_point (pc
, sp
, frame_address
)
1079 CORE_ADDR frame_address
;
1081 return ((pc
) >= CALL_DUMMY_ADDRESS ()
1082 && (pc
) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK
));
1087 * GENERIC DUMMY FRAMES
1089 * The following code serves to maintain the dummy stack frames for
1090 * inferior function calls (ie. when gdb calls into the inferior via
1091 * call_function_by_hand). This code saves the machine state before
1092 * the call in host memory, so we must maintain an independant stack
1093 * and keep it consistant etc. I am attempting to make this code
1094 * generic enough to be used by many targets.
1096 * The cheapest and most generic way to do CALL_DUMMY on a new target
1097 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1098 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1099 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1100 * being executed by the target. Also FRAME_CHAIN_VALID as
1101 * generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
1102 * generic_fix_call_dummy. */
1104 /* Dummy frame. This saves the processor state just prior to setting
1105 up the inferior function call. Older targets save the registers
1106 on the target stack (but that really slows down function calls). */
1110 struct dummy_frame
*next
;
1119 static struct dummy_frame
*dummy_frame_stack
= NULL
;
1121 /* Function: find_dummy_frame(pc, fp, sp)
1122 Search the stack of dummy frames for one matching the given PC, FP and SP.
1123 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1126 generic_find_dummy_frame (pc
, fp
)
1130 struct dummy_frame
*dummyframe
;
1132 if (pc
!= entry_point_address ())
1135 for (dummyframe
= dummy_frame_stack
; dummyframe
!= NULL
;
1136 dummyframe
= dummyframe
->next
)
1137 if (fp
== dummyframe
->fp
1138 || fp
== dummyframe
->sp
1139 || fp
== dummyframe
->top
)
1140 /* The frame in question lies between the saved fp and sp, inclusive */
1141 return dummyframe
->registers
;
1146 /* Function: pc_in_call_dummy (pc, fp)
1147 Return true if this is a dummy frame created by gdb for an inferior call */
1150 generic_pc_in_call_dummy (pc
, sp
, fp
)
1155 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1156 /* Note: SP and not FP is passed on. */
1157 return (generic_find_dummy_frame (pc
, sp
) != 0);
1160 /* Function: read_register_dummy
1161 Find a saved register from before GDB calls a function in the inferior */
1164 generic_read_register_dummy (pc
, fp
, regno
)
1169 char *dummy_regs
= generic_find_dummy_frame (pc
, fp
);
1172 return extract_address (&dummy_regs
[REGISTER_BYTE (regno
)],
1173 REGISTER_RAW_SIZE (regno
));
1178 /* Save all the registers on the dummy frame stack. Most ports save the
1179 registers on the target stack. This results in lots of unnecessary memory
1180 references, which are slow when debugging via a serial line. Instead, we
1181 save all the registers internally, and never write them to the stack. The
1182 registers get restored when the called function returns to the entry point,
1183 where a breakpoint is laying in wait. */
1186 generic_push_dummy_frame ()
1188 struct dummy_frame
*dummy_frame
;
1189 CORE_ADDR fp
= (get_current_frame ())->frame
;
1191 /* check to see if there are stale dummy frames,
1192 perhaps left over from when a longjump took us out of a
1193 function that was called by the debugger */
1195 dummy_frame
= dummy_frame_stack
;
1197 if (INNER_THAN (dummy_frame
->fp
, fp
)) /* stale -- destroy! */
1199 dummy_frame_stack
= dummy_frame
->next
;
1200 free (dummy_frame
->registers
);
1202 dummy_frame
= dummy_frame_stack
;
1205 dummy_frame
= dummy_frame
->next
;
1207 dummy_frame
= xmalloc (sizeof (struct dummy_frame
));
1208 dummy_frame
->registers
= xmalloc (REGISTER_BYTES
);
1210 dummy_frame
->pc
= read_pc ();
1211 dummy_frame
->sp
= read_sp ();
1212 dummy_frame
->top
= dummy_frame
->sp
;
1213 dummy_frame
->fp
= fp
;
1214 read_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1215 dummy_frame
->next
= dummy_frame_stack
;
1216 dummy_frame_stack
= dummy_frame
;
1220 generic_save_dummy_frame_tos (sp
)
1223 dummy_frame_stack
->top
= sp
;
1226 /* Restore the machine state from either the saved dummy stack or a
1227 real stack frame. */
1230 generic_pop_current_frame (void (*popper
) (struct frame_info
* frame
))
1232 struct frame_info
*frame
= get_current_frame ();
1234 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1235 generic_pop_dummy_frame ();
1240 /* Function: pop_dummy_frame
1241 Restore the machine state from a saved dummy stack frame. */
1244 generic_pop_dummy_frame ()
1246 struct dummy_frame
*dummy_frame
= dummy_frame_stack
;
1248 /* FIXME: what if the first frame isn't the right one, eg..
1249 because one call-by-hand function has done a longjmp into another one? */
1252 error ("Can't pop dummy frame!");
1253 dummy_frame_stack
= dummy_frame
->next
;
1254 write_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1255 flush_cached_frames ();
1257 free (dummy_frame
->registers
);
1261 /* Function: frame_chain_valid
1262 Returns true for a user frame or a call_function_by_hand dummy frame,
1263 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1266 generic_file_frame_chain_valid (fp
, fi
)
1268 struct frame_info
*fi
;
1270 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi
), fp
, fp
))
1271 return 1; /* don't prune CALL_DUMMY frames */
1272 else /* fall back to default algorithm (see frame.h) */
1274 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1275 && !inside_entry_file (FRAME_SAVED_PC (fi
)));
1279 generic_func_frame_chain_valid (fp
, fi
)
1281 struct frame_info
*fi
;
1283 if (PC_IN_CALL_DUMMY ((fi
)->pc
, fp
, fp
))
1284 return 1; /* don't prune CALL_DUMMY frames */
1285 else /* fall back to default algorithm (see frame.h) */
1287 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1288 && !inside_main_func ((fi
)->pc
)
1289 && !inside_entry_func ((fi
)->pc
));
1292 /* Function: fix_call_dummy
1293 Stub function. Generic dumy frames typically do not need to fix
1294 the frame being created */
1297 generic_fix_call_dummy (dummy
, pc
, fun
, nargs
, args
, type
, gcc_p
)
1302 struct value
**args
;
1309 /* Function: get_saved_register
1310 Find register number REGNUM relative to FRAME and put its (raw,
1311 target format) contents in *RAW_BUFFER.
1313 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1314 fetched). Note that this is never set to anything other than zero
1315 in this implementation.
1317 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1318 whether the value was fetched from memory, from a register, or in a
1319 strange and non-modifiable way (e.g. a frame pointer which was
1320 calculated rather than fetched). We will use not_lval for values
1321 fetched from generic dummy frames.
1323 Set *ADDRP to the address, either in memory on as a REGISTER_BYTE
1324 offset into the registers array. If the value is stored in a dummy
1325 frame, set *ADDRP to zero.
1327 To use this implementation, define a function called
1328 "get_saved_register" in your target code, which simply passes all
1329 of its arguments to this function.
1331 The argument RAW_BUFFER must point to aligned memory. */
1334 generic_get_saved_register (raw_buffer
, optimized
, addrp
, frame
, regnum
, lval
)
1338 struct frame_info
*frame
;
1340 enum lval_type
*lval
;
1342 if (!target_has_registers
)
1343 error ("No registers.");
1345 /* Normal systems don't optimize out things with register numbers. */
1346 if (optimized
!= NULL
)
1349 if (addrp
) /* default assumption: not found in memory */
1352 /* Note: since the current frame's registers could only have been
1353 saved by frames INTERIOR TO the current frame, we skip examining
1354 the current frame itself: otherwise, we would be getting the
1355 previous frame's registers which were saved by the current frame. */
1357 while (frame
&& ((frame
= frame
->next
) != NULL
))
1359 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1361 if (lval
) /* found it in a CALL_DUMMY frame */
1365 generic_find_dummy_frame (frame
->pc
, frame
->frame
) +
1366 REGISTER_BYTE (regnum
),
1367 REGISTER_RAW_SIZE (regnum
));
1371 FRAME_INIT_SAVED_REGS (frame
);
1372 if (frame
->saved_regs
!= NULL
1373 && frame
->saved_regs
[regnum
] != 0)
1375 if (lval
) /* found it saved on the stack */
1376 *lval
= lval_memory
;
1377 if (regnum
== SP_REGNUM
)
1379 if (raw_buffer
) /* SP register treated specially */
1380 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
1381 frame
->saved_regs
[regnum
]);
1385 if (addrp
) /* any other register */
1386 *addrp
= frame
->saved_regs
[regnum
];
1388 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
1389 REGISTER_RAW_SIZE (regnum
));
1395 /* If we get thru the loop to this point, it means the register was
1396 not saved in any frame. Return the actual live-register value. */
1398 if (lval
) /* found it in a live register */
1399 *lval
= lval_register
;
1401 *addrp
= REGISTER_BYTE (regnum
);
1403 read_register_gen (regnum
, raw_buffer
);
1407 _initialize_blockframe (void)
1409 obstack_init (&frame_cache_obstack
);