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, Boston, MA 02111-1307, USA. */
29 #include "value.h" /* for read_register */
30 #include "target.h" /* for target_has_stack */
31 #include "inferior.h" /* for read_pc */
34 /* Prototypes for exported functions. */
36 void _initialize_blockframe
PARAMS ((void));
38 /* A default FRAME_CHAIN_VALID, in the form that is suitable for most
39 targets. If FRAME_CHAIN_VALID returns zero it means that the given
40 frame is the outermost one and has no caller. */
43 default_frame_chain_valid (chain
, thisframe
)
45 struct frame_info
*thisframe
;
48 && !inside_main_func ((thisframe
) -> pc
)
49 && !inside_entry_func ((thisframe
) -> pc
));
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 alternate_frame_chain_valid (chain
, thisframe
)
59 struct frame_info
*thisframe
;
62 && !inside_entry_file (FRAME_SAVED_PC (thisframe
)));
65 /* A very simple method of determining a valid frame */
68 nonnull_frame_chain_valid (chain
, thisframe
)
70 struct frame_info
*thisframe
;
72 return ((chain
) != 0);
75 /* Is ADDR inside the startup file? Note that if your machine
76 has a way to detect the bottom of the stack, there is no need
77 to call this function from FRAME_CHAIN_VALID; the reason for
78 doing so is that some machines have no way of detecting bottom
81 A PC of zero is always considered to be the bottom of the stack. */
84 inside_entry_file (addr
)
89 if (symfile_objfile
== 0)
91 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
93 /* Do not stop backtracing if the pc is in the call dummy
94 at the entry point. */
95 /* FIXME: Won't always work with zeros for the last two arguments */
96 if (PC_IN_CALL_DUMMY (addr
, 0, 0))
99 return (addr
>= symfile_objfile
-> ei
.entry_file_lowpc
&&
100 addr
< symfile_objfile
-> ei
.entry_file_highpc
);
103 /* Test a specified PC value to see if it is in the range of addresses
104 that correspond to the main() function. See comments above for why
105 we might want to do this.
107 Typically called from FRAME_CHAIN_VALID.
109 A PC of zero is always considered to be the bottom of the stack. */
112 inside_main_func (pc
)
117 if (symfile_objfile
== 0)
120 /* If the addr range is not set up at symbol reading time, set it up now.
121 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
122 it is unable to set it up and symbol reading time. */
124 if (symfile_objfile
-> ei
.main_func_lowpc
== INVALID_ENTRY_LOWPC
&&
125 symfile_objfile
-> ei
.main_func_highpc
== INVALID_ENTRY_HIGHPC
)
127 struct symbol
*mainsym
;
129 mainsym
= lookup_symbol ("main", NULL
, VAR_NAMESPACE
, NULL
, NULL
);
130 if (mainsym
&& SYMBOL_CLASS(mainsym
) == LOC_BLOCK
)
132 symfile_objfile
->ei
.main_func_lowpc
=
133 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym
));
134 symfile_objfile
->ei
.main_func_highpc
=
135 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym
));
138 return (symfile_objfile
-> ei
.main_func_lowpc
<= pc
&&
139 symfile_objfile
-> ei
.main_func_highpc
> pc
);
142 /* Test a specified PC value to see if it is in the range of addresses
143 that correspond to the process entry point function. See comments
144 in objfiles.h for why we might want to do this.
146 Typically called from FRAME_CHAIN_VALID.
148 A PC of zero is always considered to be the bottom of the stack. */
151 inside_entry_func (pc
)
156 if (symfile_objfile
== 0)
158 if (CALL_DUMMY_LOCATION
== AT_ENTRY_POINT
)
160 /* Do not stop backtracing if the pc is in the call dummy
161 at the entry point. */
162 /* FIXME: Won't always work with zeros for the last two arguments */
163 if (PC_IN_CALL_DUMMY (pc
, 0, 0))
166 return (symfile_objfile
-> ei
.entry_func_lowpc
<= pc
&&
167 symfile_objfile
-> ei
.entry_func_highpc
> pc
);
170 /* Info about the innermost stack frame (contents of FP register) */
172 static struct frame_info
*current_frame
;
174 /* Cache for frame addresses already read by gdb. Valid only while
175 inferior is stopped. Control variables for the frame cache should
176 be local to this module. */
178 static struct obstack frame_cache_obstack
;
181 frame_obstack_alloc (size
)
184 return obstack_alloc (&frame_cache_obstack
, size
);
188 frame_saved_regs_zalloc (fi
)
189 struct frame_info
*fi
;
191 fi
->saved_regs
= (CORE_ADDR
*)
192 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
193 memset (fi
->saved_regs
, 0, SIZEOF_FRAME_SAVED_REGS
);
197 /* Return the innermost (currently executing) stack frame. */
202 if (current_frame
== NULL
)
204 if (target_has_stack
)
205 current_frame
= create_new_frame (read_fp (), read_pc ());
209 return current_frame
;
213 set_current_frame (frame
)
214 struct frame_info
*frame
;
216 current_frame
= frame
;
219 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
220 Always returns a non-NULL value. */
223 create_new_frame (addr
, pc
)
227 struct frame_info
*fi
;
230 fi
= (struct frame_info
*)
231 obstack_alloc (&frame_cache_obstack
,
232 sizeof (struct frame_info
));
234 /* Arbitrary frame */
235 fi
->saved_regs
= NULL
;
240 find_pc_partial_function (pc
, &name
, (CORE_ADDR
*)NULL
,(CORE_ADDR
*)NULL
);
241 fi
->signal_handler_caller
= IN_SIGTRAMP (fi
->pc
, name
);
243 #ifdef INIT_EXTRA_FRAME_INFO
244 INIT_EXTRA_FRAME_INFO (0, fi
);
250 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
254 get_next_frame (frame
)
255 struct frame_info
*frame
;
260 /* Flush the entire frame cache. */
263 flush_cached_frames ()
265 /* Since we can't really be sure what the first object allocated was */
266 obstack_free (&frame_cache_obstack
, 0);
267 obstack_init (&frame_cache_obstack
);
269 current_frame
= NULL
; /* Invalidate cache */
270 select_frame (NULL
, -1);
271 annotate_frames_invalid ();
274 /* Flush the frame cache, and start a new one if necessary. */
277 reinit_frame_cache ()
279 flush_cached_frames ();
281 /* FIXME: The inferior_pid test is wrong if there is a corefile. */
282 if (inferior_pid
!= 0)
284 select_frame (get_current_frame (), 0);
288 /* If a machine allows frameless functions, it should define a macro
289 FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct
290 frame_info for the frame, and FRAMELESS should be set to nonzero
291 if it represents a frameless function invocation. */
293 /* Return nonzero if the function for this frame lacks a prologue. Many
294 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
298 frameless_look_for_prologue (frame
)
299 struct frame_info
*frame
;
301 CORE_ADDR func_start
, after_prologue
;
302 func_start
= get_pc_function_start (frame
->pc
);
305 func_start
+= FUNCTION_START_OFFSET
;
306 after_prologue
= func_start
;
307 #ifdef SKIP_PROLOGUE_FRAMELESS_P
308 /* This is faster, since only care whether there *is* a prologue,
309 not how long it is. */
310 after_prologue
= SKIP_PROLOGUE_FRAMELESS_P (after_prologue
);
312 after_prologue
= SKIP_PROLOGUE (after_prologue
);
314 return after_prologue
== func_start
;
316 else if (frame
->pc
== 0)
317 /* A frame with a zero PC is usually created by dereferencing a NULL
318 function pointer, normally causing an immediate core dump of the
319 inferior. Mark function as frameless, as the inferior has no chance
320 of setting up a stack frame. */
323 /* If we can't find the start of the function, we don't really
324 know whether the function is frameless, but we should be able
325 to get a reasonable (i.e. best we can do under the
326 circumstances) backtrace by saying that it isn't. */
330 /* Default a few macros that people seldom redefine. */
332 #if !defined (INIT_FRAME_PC)
333 #define INIT_FRAME_PC(fromleaf, prev) \
334 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
335 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
338 #ifndef FRAME_CHAIN_COMBINE
339 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
342 /* Return a structure containing various interesting information
343 about the frame that called NEXT_FRAME. Returns NULL
344 if there is no such frame. */
347 get_prev_frame (next_frame
)
348 struct frame_info
*next_frame
;
350 CORE_ADDR address
= 0;
351 struct frame_info
*prev
;
355 /* If the requested entry is in the cache, return it.
356 Otherwise, figure out what the address should be for the entry
357 we're about to add to the cache. */
362 /* This screws value_of_variable, which just wants a nice clean
363 NULL return from block_innermost_frame if there are no frames.
364 I don't think I've ever seen this message happen otherwise.
365 And returning NULL here is a perfectly legitimate thing to do. */
368 error ("You haven't set up a process's stack to examine.");
372 return current_frame
;
375 /* If we have the prev one, return it */
376 if (next_frame
->prev
)
377 return next_frame
->prev
;
379 /* On some machines it is possible to call a function without
380 setting up a stack frame for it. On these machines, we
381 define this macro to take two args; a frameinfo pointer
382 identifying a frame and a variable to set or clear if it is
383 or isn't leafless. */
385 /* Still don't want to worry about this except on the innermost
386 frame. This macro will set FROMLEAF if NEXT_FRAME is a
387 frameless function invocation. */
388 if (!(next_frame
->next
))
390 fromleaf
= FRAMELESS_FUNCTION_INVOCATION (next_frame
);
392 address
= FRAME_FP (next_frame
);
397 /* Two macros defined in tm.h specify the machine-dependent
398 actions to be performed here.
399 First, get the frame's chain-pointer.
400 If that is zero, the frame is the outermost frame or a leaf
401 called by the outermost frame. This means that if start
402 calls main without a frame, we'll return 0 (which is fine
405 Nope; there's a problem. This also returns when the current
406 routine is a leaf of main. This is unacceptable. We move
407 this to after the ffi test; I'd rather have backtraces from
408 start go curfluy than have an abort called from main not show
410 address
= FRAME_CHAIN (next_frame
);
411 if (!FRAME_CHAIN_VALID (address
, next_frame
))
413 address
= FRAME_CHAIN_COMBINE (address
, next_frame
);
418 prev
= (struct frame_info
*)
419 obstack_alloc (&frame_cache_obstack
,
420 sizeof (struct frame_info
));
422 prev
->saved_regs
= NULL
;
424 next_frame
->prev
= prev
;
425 prev
->next
= next_frame
;
426 prev
->prev
= (struct frame_info
*) 0;
427 prev
->frame
= address
;
428 prev
->signal_handler_caller
= 0;
430 /* This change should not be needed, FIXME! We should
431 determine whether any targets *need* INIT_FRAME_PC to happen
432 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
433 express what goes on here.
435 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
436 (where the PC is already set up) and here (where it isn't).
437 INIT_FRAME_PC is only called from here, always after
438 INIT_EXTRA_FRAME_INFO.
440 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
441 value (which hasn't been set yet). Some other machines appear to
442 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
444 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
445 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
447 Assuming that some machines need INIT_FRAME_PC after
448 INIT_EXTRA_FRAME_INFO, one possible scheme:
450 SETUP_INNERMOST_FRAME()
451 Default version is just create_new_frame (read_fp ()),
452 read_pc ()). Machines with extra frame info would do that (or the
453 local equivalent) and then set the extra fields.
454 SETUP_ARBITRARY_FRAME(argc, argv)
455 Only change here is that create_new_frame would no longer init extra
456 frame info; SETUP_ARBITRARY_FRAME would have to do that.
457 INIT_PREV_FRAME(fromleaf, prev)
458 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
459 also return a flag saying whether to keep the new frame, or
460 whether to discard it, because on some machines (e.g. mips) it
461 is really awkward to have FRAME_CHAIN_VALID called *before*
462 INIT_EXTRA_FRAME_INFO (there is no good way to get information
463 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
464 std_frame_pc(fromleaf, prev)
465 This is the default setting for INIT_PREV_FRAME. It just does what
466 the default INIT_FRAME_PC does. Some machines will call it from
467 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
468 Some machines won't use it.
469 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
471 #ifdef INIT_FRAME_PC_FIRST
472 INIT_FRAME_PC_FIRST (fromleaf
, prev
);
475 #ifdef INIT_EXTRA_FRAME_INFO
476 INIT_EXTRA_FRAME_INFO(fromleaf
, prev
);
479 /* This entry is in the frame queue now, which is good since
480 FRAME_SAVED_PC may use that queue to figure out its value
481 (see tm-sparc.h). We want the pc saved in the inferior frame. */
482 INIT_FRAME_PC(fromleaf
, prev
);
484 /* If ->frame and ->pc are unchanged, we are in the process of getting
485 ourselves into an infinite backtrace. Some architectures check this
486 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
487 this can't be an architecture-independent check. */
488 if (next_frame
!= NULL
)
490 if (prev
->frame
== next_frame
->frame
491 && prev
->pc
== next_frame
->pc
)
493 next_frame
->prev
= NULL
;
494 obstack_free (&frame_cache_obstack
, prev
);
499 find_pc_partial_function (prev
->pc
, &name
,
500 (CORE_ADDR
*)NULL
,(CORE_ADDR
*)NULL
);
501 if (IN_SIGTRAMP (prev
->pc
, name
))
502 prev
->signal_handler_caller
= 1;
509 struct frame_info
*frame
;
515 #ifdef FRAME_FIND_SAVED_REGS
516 /* XXX - deprecated. This is a compatibility function for targets
517 that do not yet implement FRAME_INIT_SAVED_REGS. */
518 /* Find the addresses in which registers are saved in FRAME. */
521 get_frame_saved_regs (frame
, saved_regs_addr
)
522 struct frame_info
*frame
;
523 struct frame_saved_regs
*saved_regs_addr
;
525 if (frame
->saved_regs
== NULL
)
527 frame
->saved_regs
= (CORE_ADDR
*)
528 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS
);
530 if (saved_regs_addr
== NULL
)
532 struct frame_saved_regs saved_regs
;
533 FRAME_FIND_SAVED_REGS (frame
, saved_regs
);
534 memcpy (frame
->saved_regs
, &saved_regs
, SIZEOF_FRAME_SAVED_REGS
);
538 FRAME_FIND_SAVED_REGS (frame
, *saved_regs_addr
);
539 memcpy (frame
->saved_regs
, saved_regs_addr
, SIZEOF_FRAME_SAVED_REGS
);
544 /* Return the innermost lexical block in execution
545 in a specified stack frame. The frame address is assumed valid. */
548 get_frame_block (frame
)
549 struct frame_info
*frame
;
554 if (frame
->next
!= 0 && frame
->next
->signal_handler_caller
== 0)
555 /* We are not in the innermost frame and we were not interrupted
556 by a signal. We need to subtract one to get the correct block,
557 in case the call instruction was the last instruction of the block.
558 If there are any machines on which the saved pc does not point to
559 after the call insn, we probably want to make frame->pc point after
560 the call insn anyway. */
562 return block_for_pc (pc
);
568 return block_for_pc (read_pc ());
572 get_pc_function_start (pc
)
575 register struct block
*bl
;
576 register struct symbol
*symbol
;
577 register struct minimal_symbol
*msymbol
;
580 if ((bl
= block_for_pc (pc
)) != NULL
&&
581 (symbol
= block_function (bl
)) != NULL
)
583 bl
= SYMBOL_BLOCK_VALUE (symbol
);
584 fstart
= BLOCK_START (bl
);
586 else if ((msymbol
= lookup_minimal_symbol_by_pc (pc
)) != NULL
)
588 fstart
= SYMBOL_VALUE_ADDRESS (msymbol
);
597 /* Return the symbol for the function executing in frame FRAME. */
600 get_frame_function (frame
)
601 struct frame_info
*frame
;
603 register struct block
*bl
= get_frame_block (frame
);
606 return block_function (bl
);
610 /* Return the blockvector immediately containing the innermost lexical block
611 containing the specified pc value and section, or 0 if there is none.
612 PINDEX is a pointer to the index value of the block. If PINDEX
613 is NULL, we don't pass this information back to the caller. */
616 blockvector_for_pc_sect (pc
, section
, pindex
, symtab
)
617 register CORE_ADDR pc
;
620 struct symtab
*symtab
;
623 register struct block
*b
;
624 register int bot
, top
, half
;
625 struct blockvector
*bl
;
627 if (symtab
== 0) /* if no symtab specified by caller */
629 /* First search all symtabs for one whose file contains our pc */
630 if ((symtab
= find_pc_sect_symtab (pc
, section
)) == 0)
634 bl
= BLOCKVECTOR (symtab
);
635 b
= BLOCKVECTOR_BLOCK (bl
, 0);
637 /* Then search that symtab for the smallest block that wins. */
638 /* Use binary search to find the last block that starts before PC. */
641 top
= BLOCKVECTOR_NBLOCKS (bl
);
643 while (top
- bot
> 1)
645 half
= (top
- bot
+ 1) >> 1;
646 b
= BLOCKVECTOR_BLOCK (bl
, bot
+ half
);
647 if (BLOCK_START (b
) <= pc
)
653 /* Now search backward for a block that ends after PC. */
657 b
= BLOCKVECTOR_BLOCK (bl
, bot
);
658 if (BLOCK_END (b
) >= pc
)
669 /* Return the blockvector immediately containing the innermost lexical block
670 containing the specified pc value, or 0 if there is none.
671 Backward compatibility, no section. */
674 blockvector_for_pc (pc
, pindex
)
675 register CORE_ADDR pc
;
678 return blockvector_for_pc_sect (pc
, find_pc_mapped_section (pc
),
682 /* Return the innermost lexical block containing the specified pc value
683 in the specified section, or 0 if there is none. */
686 block_for_pc_sect (pc
, section
)
687 register CORE_ADDR pc
;
690 register struct blockvector
*bl
;
693 bl
= blockvector_for_pc_sect (pc
, section
, &index
, NULL
);
695 return BLOCKVECTOR_BLOCK (bl
, index
);
699 /* Return the innermost lexical block containing the specified pc value,
700 or 0 if there is none. Backward compatibility, no section. */
704 register CORE_ADDR pc
;
706 return block_for_pc_sect (pc
, find_pc_mapped_section (pc
));
709 /* Return the function containing pc value PC in section SECTION.
710 Returns 0 if function is not known. */
713 find_pc_sect_function (pc
, section
)
717 register struct block
*b
= block_for_pc_sect (pc
, section
);
720 return block_function (b
);
723 /* Return the function containing pc value PC.
724 Returns 0 if function is not known. Backward compatibility, no section */
727 find_pc_function (pc
)
730 return find_pc_sect_function (pc
, find_pc_mapped_section (pc
));
733 /* These variables are used to cache the most recent result
734 * of find_pc_partial_function. */
736 static CORE_ADDR cache_pc_function_low
= 0;
737 static CORE_ADDR cache_pc_function_high
= 0;
738 static char *cache_pc_function_name
= 0;
739 static struct sec
*cache_pc_function_section
= NULL
;
741 /* Clear cache, e.g. when symbol table is discarded. */
744 clear_pc_function_cache()
746 cache_pc_function_low
= 0;
747 cache_pc_function_high
= 0;
748 cache_pc_function_name
= (char *)0;
749 cache_pc_function_section
= NULL
;
752 /* Finds the "function" (text symbol) that is smaller than PC but
753 greatest of all of the potential text symbols in SECTION. Sets
754 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
755 If ENDADDR is non-null, then set *ENDADDR to be the end of the
756 function (exclusive), but passing ENDADDR as non-null means that
757 the function might cause symbols to be read. This function either
758 succeeds or fails (not halfway succeeds). If it succeeds, it sets
759 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
760 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
764 find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
)
771 struct partial_symtab
*pst
;
773 struct minimal_symbol
*msymbol
;
774 struct partial_symbol
*psb
;
775 struct obj_section
*osect
;
779 mapped_pc
= overlay_mapped_address (pc
, section
);
781 if (mapped_pc
>= cache_pc_function_low
&&
782 mapped_pc
< cache_pc_function_high
&&
783 section
== cache_pc_function_section
)
784 goto return_cached_value
;
786 /* If sigtramp is in the u area, it counts as a function (especially
787 important for step_1). */
788 #if defined SIGTRAMP_START
789 if (IN_SIGTRAMP (mapped_pc
, (char *)NULL
))
791 cache_pc_function_low
= SIGTRAMP_START (mapped_pc
);
792 cache_pc_function_high
= SIGTRAMP_END (mapped_pc
);
793 cache_pc_function_name
= "<sigtramp>";
794 cache_pc_function_section
= section
;
795 goto return_cached_value
;
799 msymbol
= lookup_minimal_symbol_by_pc_section (mapped_pc
, section
);
800 pst
= find_pc_sect_psymtab (mapped_pc
, section
);
803 /* Need to read the symbols to get a good value for the end address. */
804 if (endaddr
!= NULL
&& !pst
->readin
)
806 /* Need to get the terminal in case symbol-reading produces
808 target_terminal_ours_for_output ();
809 PSYMTAB_TO_SYMTAB (pst
);
814 /* Checking whether the msymbol has a larger value is for the
815 "pathological" case mentioned in print_frame_info. */
816 f
= find_pc_sect_function (mapped_pc
, section
);
819 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f
))
820 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
822 cache_pc_function_low
= BLOCK_START (SYMBOL_BLOCK_VALUE (f
));
823 cache_pc_function_high
= BLOCK_END (SYMBOL_BLOCK_VALUE (f
));
824 cache_pc_function_name
= SYMBOL_NAME (f
);
825 cache_pc_function_section
= section
;
826 goto return_cached_value
;
831 /* Now that static symbols go in the minimal symbol table, perhaps
832 we could just ignore the partial symbols. But at least for now
833 we use the partial or minimal symbol, whichever is larger. */
834 psb
= find_pc_sect_psymbol (pst
, mapped_pc
, section
);
837 && (msymbol
== NULL
||
838 (SYMBOL_VALUE_ADDRESS (psb
)
839 >= SYMBOL_VALUE_ADDRESS (msymbol
))))
841 /* This case isn't being cached currently. */
843 *address
= SYMBOL_VALUE_ADDRESS (psb
);
845 *name
= SYMBOL_NAME (psb
);
846 /* endaddr non-NULL can't happen here. */
852 /* Not in the normal symbol tables, see if the pc is in a known section.
853 If it's not, then give up. This ensures that anything beyond the end
854 of the text seg doesn't appear to be part of the last function in the
857 osect
= find_pc_sect_section (mapped_pc
, section
);
862 /* Must be in the minimal symbol table. */
865 /* No available symbol. */
875 cache_pc_function_low
= SYMBOL_VALUE_ADDRESS (msymbol
);
876 cache_pc_function_name
= SYMBOL_NAME (msymbol
);
877 cache_pc_function_section
= section
;
879 /* Use the lesser of the next minimal symbol in the same section, or
880 the end of the section, as the end of the function. */
882 /* Step over other symbols at this same address, and symbols in
883 other sections, to find the next symbol in this section with
884 a different address. */
886 for (i
=1; SYMBOL_NAME (msymbol
+i
) != NULL
; i
++)
888 if (SYMBOL_VALUE_ADDRESS (msymbol
+i
) != SYMBOL_VALUE_ADDRESS (msymbol
)
889 && SYMBOL_BFD_SECTION (msymbol
+i
) == SYMBOL_BFD_SECTION (msymbol
))
893 if (SYMBOL_NAME (msymbol
+ i
) != NULL
894 && SYMBOL_VALUE_ADDRESS (msymbol
+ i
) < osect
->endaddr
)
895 cache_pc_function_high
= SYMBOL_VALUE_ADDRESS (msymbol
+ i
);
897 /* We got the start address from the last msymbol in the objfile.
898 So the end address is the end of the section. */
899 cache_pc_function_high
= osect
->endaddr
;
905 if (pc_in_unmapped_range (pc
, section
))
906 *address
= overlay_unmapped_address (cache_pc_function_low
, section
);
908 *address
= cache_pc_function_low
;
912 *name
= cache_pc_function_name
;
916 if (pc_in_unmapped_range (pc
, section
))
918 /* Because the high address is actually beyond the end of
919 the function (and therefore possibly beyond the end of
920 the overlay), we must actually convert (high - 1)
921 and then add one to that. */
923 *endaddr
= 1 + overlay_unmapped_address (cache_pc_function_high
- 1,
927 *endaddr
= cache_pc_function_high
;
933 /* Backward compatibility, no section argument */
936 find_pc_partial_function (pc
, name
, address
, endaddr
)
944 section
= find_pc_overlay (pc
);
945 return find_pc_sect_partial_function (pc
, section
, name
, address
, endaddr
);
948 /* Return the innermost stack frame executing inside of BLOCK,
949 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
952 block_innermost_frame (block
)
955 struct frame_info
*frame
;
956 register CORE_ADDR start
;
957 register CORE_ADDR end
;
962 start
= BLOCK_START (block
);
963 end
= BLOCK_END (block
);
968 frame
= get_prev_frame (frame
);
971 if (frame
->pc
>= start
&& frame
->pc
< end
)
976 /* Return the full FRAME which corresponds to the given CORE_ADDR
977 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
980 find_frame_addr_in_frame_chain (frame_addr
)
981 CORE_ADDR frame_addr
;
983 struct frame_info
*frame
= NULL
;
985 if (frame_addr
== (CORE_ADDR
)0)
990 frame
= get_prev_frame (frame
);
993 if (FRAME_FP (frame
) == frame_addr
)
998 #ifdef SIGCONTEXT_PC_OFFSET
999 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
1002 sigtramp_saved_pc (frame
)
1003 struct frame_info
*frame
;
1005 CORE_ADDR sigcontext_addr
;
1006 char buf
[TARGET_PTR_BIT
/ TARGET_CHAR_BIT
];
1007 int ptrbytes
= TARGET_PTR_BIT
/ TARGET_CHAR_BIT
;
1008 int sigcontext_offs
= (2 * TARGET_INT_BIT
) / TARGET_CHAR_BIT
;
1010 /* Get sigcontext address, it is the third parameter on the stack. */
1012 sigcontext_addr
= read_memory_integer (FRAME_ARGS_ADDRESS (frame
->next
)
1017 sigcontext_addr
= read_memory_integer (read_register (SP_REGNUM
)
1021 /* Don't cause a memory_error when accessing sigcontext in case the stack
1022 layout has changed or the stack is corrupt. */
1023 target_read_memory (sigcontext_addr
+ SIGCONTEXT_PC_OFFSET
, buf
, ptrbytes
);
1024 return extract_unsigned_integer (buf
, ptrbytes
);
1026 #endif /* SIGCONTEXT_PC_OFFSET */
1029 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
1030 below is for infrun.c, which may give the macro a pc without that
1033 extern CORE_ADDR text_end
;
1036 pc_in_call_dummy_before_text_end (pc
, sp
, frame_address
)
1039 CORE_ADDR frame_address
;
1041 return ((pc
) >= text_end
- CALL_DUMMY_LENGTH
1042 && (pc
) <= text_end
+ DECR_PC_AFTER_BREAK
);
1046 pc_in_call_dummy_after_text_end (pc
, sp
, frame_address
)
1049 CORE_ADDR frame_address
;
1051 return ((pc
) >= text_end
1052 && (pc
) <= text_end
+ CALL_DUMMY_LENGTH
+ DECR_PC_AFTER_BREAK
);
1055 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1056 top of the stack frame which we are checking, where "bottom" and
1057 "top" refer to some section of memory which contains the code for
1058 the call dummy. Calls to this macro assume that the contents of
1059 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1060 are the things to pass.
1062 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1063 have that meaning, but the 29k doesn't use ON_STACK. This could be
1064 fixed by generalizing this scheme, perhaps by passing in a frame
1065 and adding a few fields, at least on machines which need them for
1068 Something simpler, like checking for the stack segment, doesn't work,
1069 since various programs (threads implementations, gcc nested function
1070 stubs, etc) may either allocate stack frames in another segment, or
1071 allocate other kinds of code on the stack. */
1074 pc_in_call_dummy_on_stack (pc
, sp
, frame_address
)
1077 CORE_ADDR frame_address
;
1079 return (INNER_THAN ((sp
), (pc
))
1080 && (frame_address
!= 0)
1081 && INNER_THAN ((pc
), (frame_address
)));
1085 pc_in_call_dummy_at_entry_point (pc
, sp
, frame_address
)
1088 CORE_ADDR frame_address
;
1090 return ((pc
) >= CALL_DUMMY_ADDRESS ()
1091 && (pc
) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK
));
1096 * GENERIC DUMMY FRAMES
1098 * The following code serves to maintain the dummy stack frames for
1099 * inferior function calls (ie. when gdb calls into the inferior via
1100 * call_function_by_hand). This code saves the machine state before
1101 * the call in host memory, so we must maintain an independant stack
1102 * and keep it consistant etc. I am attempting to make this code
1103 * generic enough to be used by many targets.
1105 * The cheapest and most generic way to do CALL_DUMMY on a new target
1106 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1107 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1108 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1109 * being executed by the target. Also FRAME_CHAIN_VALID as
1110 * generic_frame_chain_valid. */
1112 /* Dummy frame. This saves the processor state just prior to setting
1113 up the inferior function call. Older targets save the registers
1114 target stack (but that really slows down function calls). */
1118 struct dummy_frame
*next
;
1126 static struct dummy_frame
*dummy_frame_stack
= NULL
;
1128 /* Function: find_dummy_frame(pc, fp, sp)
1129 Search the stack of dummy frames for one matching the given PC, FP and SP.
1130 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1133 generic_find_dummy_frame (pc
, fp
)
1137 struct dummy_frame
* dummyframe
;
1139 if (pc
!= entry_point_address ())
1142 for (dummyframe
= dummy_frame_stack
; dummyframe
!= NULL
;
1143 dummyframe
= dummyframe
->next
)
1144 if (fp
== dummyframe
->fp
|| fp
== dummyframe
->sp
)
1145 /* The frame in question lies between the saved fp and sp, inclusive */
1146 return dummyframe
->registers
;
1151 /* Function: pc_in_call_dummy (pc, fp)
1152 Return true if this is a dummy frame created by gdb for an inferior call */
1155 generic_pc_in_call_dummy (pc
, sp
, fp
)
1160 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1161 /* Note: SP and not FP is passed on. */
1162 return (generic_find_dummy_frame (pc
, sp
) != 0);
1165 /* Function: read_register_dummy
1166 Find a saved register from before GDB calls a function in the inferior */
1169 generic_read_register_dummy (pc
, fp
, regno
)
1174 char *dummy_regs
= generic_find_dummy_frame (pc
, fp
);
1177 return extract_address (&dummy_regs
[REGISTER_BYTE (regno
)],
1178 REGISTER_RAW_SIZE(regno
));
1183 /* Save all the registers on the dummy frame stack. Most ports save the
1184 registers on the target stack. This results in lots of unnecessary memory
1185 references, which are slow when debugging via a serial line. Instead, we
1186 save all the registers internally, and never write them to the stack. The
1187 registers get restored when the called function returns to the entry point,
1188 where a breakpoint is laying in wait. */
1191 generic_push_dummy_frame ()
1193 struct dummy_frame
*dummy_frame
;
1194 CORE_ADDR fp
= (get_current_frame ())->frame
;
1196 /* check to see if there are stale dummy frames,
1197 perhaps left over from when a longjump took us out of a
1198 function that was called by the debugger */
1200 dummy_frame
= dummy_frame_stack
;
1202 if (INNER_THAN (dummy_frame
->fp
, fp
)) /* stale -- destroy! */
1204 dummy_frame_stack
= dummy_frame
->next
;
1206 dummy_frame
= dummy_frame_stack
;
1209 dummy_frame
= dummy_frame
->next
;
1211 dummy_frame
= xmalloc (sizeof (struct dummy_frame
));
1212 dummy_frame
->registers
= xmalloc (REGISTER_BYTES
);
1214 dummy_frame
->pc
= read_register (PC_REGNUM
);
1215 dummy_frame
->sp
= read_register (SP_REGNUM
);
1216 dummy_frame
->fp
= fp
;
1217 read_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1218 dummy_frame
->next
= dummy_frame_stack
;
1219 dummy_frame_stack
= dummy_frame
;
1222 /* Function: pop_frame
1223 Restore the machine state from either the saved dummy stack or a
1224 real stack frame. */
1227 generic_pop_current_frame (pop
)
1228 void (*pop
) PARAMS ((struct frame_info
*frame
));
1230 struct frame_info
*frame
= get_current_frame ();
1231 if (PC_IN_CALL_DUMMY(frame
->pc
, frame
->frame
, frame
->frame
))
1232 generic_pop_dummy_frame ();
1237 /* Function: pop_dummy_frame
1238 Restore the machine state from a saved dummy stack frame. */
1241 generic_pop_dummy_frame ()
1243 struct dummy_frame
*dummy_frame
= dummy_frame_stack
;
1245 /* FIXME: what if the first frame isn't the right one, eg..
1246 because one call-by-hand function has done a longjmp into another one? */
1249 error ("Can't pop dummy frame!");
1250 dummy_frame_stack
= dummy_frame
->next
;
1251 write_register_bytes (0, dummy_frame
->registers
, REGISTER_BYTES
);
1252 flush_cached_frames ();
1254 free (dummy_frame
->registers
);
1258 /* Function: frame_chain_valid
1259 Returns true for a user frame or a call_function_by_hand dummy frame,
1260 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1263 generic_frame_chain_valid (fp
, fi
)
1265 struct frame_info
*fi
;
1267 if (PC_IN_CALL_DUMMY(FRAME_SAVED_PC(fi
), fp
, fp
))
1268 return 1; /* don't prune CALL_DUMMY frames */
1269 else /* fall back to default algorithm (see frame.h) */
1271 && (INNER_THAN (fi
->frame
, fp
) || fi
->frame
== fp
)
1272 && !inside_entry_file (FRAME_SAVED_PC(fi
)));
1275 /* Function: get_saved_register
1276 Find register number REGNUM relative to FRAME and put its (raw,
1277 target format) contents in *RAW_BUFFER.
1279 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1280 fetched). Note that this is never set to anything other than zero
1281 in this implementation.
1283 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1284 whether the value was fetched from memory, from a register, or in a
1285 strange and non-modifiable way (e.g. a frame pointer which was
1286 calculated rather than fetched). We will use not_lval for values
1287 fetched from generic dummy frames.
1289 Set *ADDRP to the address, either in memory on as a REGISTER_BYTE
1290 offset into the registers array. If the value is stored in a dummy
1291 frame, set *ADDRP to zero.
1293 To use this implementation, define a function called
1294 "get_saved_register" in your target code, which simply passes all
1295 of its arguments to this function.
1297 The argument RAW_BUFFER must point to aligned memory. */
1300 generic_get_saved_register (raw_buffer
, optimized
, addrp
, frame
, regnum
, lval
)
1304 struct frame_info
*frame
;
1306 enum lval_type
*lval
;
1308 if (!target_has_registers
)
1309 error ("No registers.");
1311 /* Normal systems don't optimize out things with register numbers. */
1312 if (optimized
!= NULL
)
1315 if (addrp
) /* default assumption: not found in memory */
1318 /* Note: since the current frame's registers could only have been
1319 saved by frames INTERIOR TO the current frame, we skip examining
1320 the current frame itself: otherwise, we would be getting the
1321 previous frame's registers which were saved by the current frame. */
1323 while (frame
&& ((frame
= frame
->next
) != NULL
))
1325 if (PC_IN_CALL_DUMMY (frame
->pc
, frame
->frame
, frame
->frame
))
1327 if (lval
) /* found it in a CALL_DUMMY frame */
1331 generic_find_dummy_frame (frame
->pc
, frame
->frame
) +
1332 REGISTER_BYTE (regnum
),
1333 REGISTER_RAW_SIZE (regnum
));
1337 FRAME_INIT_SAVED_REGS (frame
);
1338 if (frame
->saved_regs
!= NULL
1339 && frame
->saved_regs
[regnum
] != 0)
1341 if (lval
) /* found it saved on the stack */
1342 *lval
= lval_memory
;
1343 if (regnum
== SP_REGNUM
)
1345 if (raw_buffer
) /* SP register treated specially */
1346 store_address (raw_buffer
, REGISTER_RAW_SIZE (regnum
),
1347 frame
->saved_regs
[regnum
]);
1351 if (addrp
) /* any other register */
1352 *addrp
= frame
->saved_regs
[regnum
];
1354 read_memory (frame
->saved_regs
[regnum
], raw_buffer
,
1355 REGISTER_RAW_SIZE (regnum
));
1361 /* If we get thru the loop to this point, it means the register was
1362 not saved in any frame. Return the actual live-register value. */
1364 if (lval
) /* found it in a live register */
1365 *lval
= lval_register
;
1367 *addrp
= REGISTER_BYTE (regnum
);
1369 read_register_gen (regnum
, raw_buffer
);
1373 _initialize_blockframe ()
1375 obstack_init (&frame_cache_obstack
);