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 (CORE_ADDR chain, struct frame_info *thisframe)
47 && !inside_entry_file (FRAME_SAVED_PC (thisframe)));
50 /* Use the alternate method of avoiding running up off the end of the
51 frame chain or following frames back into the startup code. See
52 the comments in objfiles.h. */
55 func_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
58 && !inside_main_func ((thisframe)->pc)
59 && !inside_entry_func ((thisframe)->pc));
62 /* A very simple method of determining a valid frame */
65 nonnull_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
67 return ((chain) != 0);
70 /* Is ADDR inside the startup file? Note that if your machine
71 has a way to detect the bottom of the stack, there is no need
72 to call this function from FRAME_CHAIN_VALID; the reason for
73 doing so is that some machines have no way of detecting bottom
76 A PC of zero is always considered to be the bottom of the stack. */
79 inside_entry_file (CORE_ADDR addr)
83 if (symfile_objfile == 0)
85 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
87 /* Do not stop backtracing if the pc is in the call dummy
88 at the entry point. */
89 /* FIXME: Won't always work with zeros for the last two arguments */
90 if (PC_IN_CALL_DUMMY (addr, 0, 0))
93 return (addr >= symfile_objfile->ei.entry_file_lowpc &&
94 addr < symfile_objfile->ei.entry_file_highpc);
97 /* Test a specified PC value to see if it is in the range of addresses
98 that correspond to the main() function. See comments above for why
99 we might want to do this.
101 Typically called from FRAME_CHAIN_VALID.
103 A PC of zero is always considered to be the bottom of the stack. */
106 inside_main_func (CORE_ADDR pc)
110 if (symfile_objfile == 0)
113 /* If the addr range is not set up at symbol reading time, set it up now.
114 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
115 it is unable to set it up and symbol reading time. */
117 if (symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC &&
118 symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
120 struct symbol *mainsym;
122 mainsym = lookup_symbol ("main", NULL, VAR_NAMESPACE, NULL, NULL);
123 if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
125 symfile_objfile->ei.main_func_lowpc =
126 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
127 symfile_objfile->ei.main_func_highpc =
128 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
131 return (symfile_objfile->ei.main_func_lowpc <= pc &&
132 symfile_objfile->ei.main_func_highpc > pc);
135 /* Test a specified PC value to see if it is in the range of addresses
136 that correspond to the process entry point function. See comments
137 in objfiles.h for why we might want to do this.
139 Typically called from FRAME_CHAIN_VALID.
141 A PC of zero is always considered to be the bottom of the stack. */
144 inside_entry_func (CORE_ADDR pc)
148 if (symfile_objfile == 0)
150 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
152 /* Do not stop backtracing if the pc is in the call dummy
153 at the entry point. */
154 /* FIXME: Won't always work with zeros for the last two arguments */
155 if (PC_IN_CALL_DUMMY (pc, 0, 0))
158 return (symfile_objfile->ei.entry_func_lowpc <= pc &&
159 symfile_objfile->ei.entry_func_highpc > pc);
162 /* Info about the innermost stack frame (contents of FP register) */
164 static struct frame_info *current_frame;
166 /* Cache for frame addresses already read by gdb. Valid only while
167 inferior is stopped. Control variables for the frame cache should
168 be local to this module. */
170 static struct obstack frame_cache_obstack;
173 frame_obstack_alloc (unsigned long size)
175 return obstack_alloc (&frame_cache_obstack, size);
179 frame_saved_regs_zalloc (struct frame_info *fi)
181 fi->saved_regs = (CORE_ADDR *)
182 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
183 memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);
187 /* Return the innermost (currently executing) stack frame. */
190 get_current_frame (void)
192 if (current_frame == NULL)
194 if (target_has_stack)
195 current_frame = create_new_frame (read_fp (), read_pc ());
199 return current_frame;
203 set_current_frame (struct frame_info *frame)
205 current_frame = frame;
208 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
209 Always returns a non-NULL value. */
212 create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
214 struct frame_info *fi;
217 fi = (struct frame_info *)
218 obstack_alloc (&frame_cache_obstack,
219 sizeof (struct frame_info));
221 /* Arbitrary frame */
222 fi->saved_regs = NULL;
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_pid test is wrong if there is a corefile. */
268 if (inferior_pid != 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 #if !defined (INIT_FRAME_PC)
308 #define INIT_FRAME_PC(fromleaf, prev) \
309 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
310 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
313 #ifndef FRAME_CHAIN_COMBINE
314 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
317 /* Return a structure containing various interesting information
318 about the frame that called NEXT_FRAME. Returns NULL
319 if there is no such frame. */
322 get_prev_frame (struct frame_info *next_frame)
324 CORE_ADDR address = 0;
325 struct frame_info *prev;
329 /* If the requested entry is in the cache, return it.
330 Otherwise, figure out what the address should be for the entry
331 we're about to add to the cache. */
336 /* This screws value_of_variable, which just wants a nice clean
337 NULL return from block_innermost_frame if there are no frames.
338 I don't think I've ever seen this message happen otherwise.
339 And returning NULL here is a perfectly legitimate thing to do. */
342 error ("You haven't set up a process's stack to examine.");
346 return current_frame;
349 /* If we have the prev one, return it */
350 if (next_frame->prev)
351 return next_frame->prev;
353 /* On some machines it is possible to call a function without
354 setting up a stack frame for it. On these machines, we
355 define this macro to take two args; a frameinfo pointer
356 identifying a frame and a variable to set or clear if it is
357 or isn't leafless. */
359 /* Still don't want to worry about this except on the innermost
360 frame. This macro will set FROMLEAF if NEXT_FRAME is a
361 frameless function invocation. */
362 if (!(next_frame->next))
364 fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame);
366 address = FRAME_FP (next_frame);
371 /* Two macros defined in tm.h specify the machine-dependent
372 actions to be performed here.
373 First, get the frame's chain-pointer.
374 If that is zero, the frame is the outermost frame or a leaf
375 called by the outermost frame. This means that if start
376 calls main without a frame, we'll return 0 (which is fine
379 Nope; there's a problem. This also returns when the current
380 routine is a leaf of main. This is unacceptable. We move
381 this to after the ffi test; I'd rather have backtraces from
382 start go curfluy than have an abort called from main not show
384 address = FRAME_CHAIN (next_frame);
385 if (!FRAME_CHAIN_VALID (address, next_frame))
387 address = FRAME_CHAIN_COMBINE (address, next_frame);
392 prev = (struct frame_info *)
393 obstack_alloc (&frame_cache_obstack,
394 sizeof (struct frame_info));
396 prev->saved_regs = NULL;
398 next_frame->prev = prev;
399 prev->next = next_frame;
400 prev->prev = (struct frame_info *) 0;
401 prev->frame = address;
402 prev->signal_handler_caller = 0;
404 /* This change should not be needed, FIXME! We should
405 determine whether any targets *need* INIT_FRAME_PC to happen
406 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
407 express what goes on here.
409 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
410 (where the PC is already set up) and here (where it isn't).
411 INIT_FRAME_PC is only called from here, always after
412 INIT_EXTRA_FRAME_INFO.
414 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
415 value (which hasn't been set yet). Some other machines appear to
416 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
418 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
419 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
421 Assuming that some machines need INIT_FRAME_PC after
422 INIT_EXTRA_FRAME_INFO, one possible scheme:
424 SETUP_INNERMOST_FRAME()
425 Default version is just create_new_frame (read_fp ()),
426 read_pc ()). Machines with extra frame info would do that (or the
427 local equivalent) and then set the extra fields.
428 SETUP_ARBITRARY_FRAME(argc, argv)
429 Only change here is that create_new_frame would no longer init extra
430 frame info; SETUP_ARBITRARY_FRAME would have to do that.
431 INIT_PREV_FRAME(fromleaf, prev)
432 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
433 also return a flag saying whether to keep the new frame, or
434 whether to discard it, because on some machines (e.g. mips) it
435 is really awkward to have FRAME_CHAIN_VALID called *before*
436 INIT_EXTRA_FRAME_INFO (there is no good way to get information
437 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
438 std_frame_pc(fromleaf, prev)
439 This is the default setting for INIT_PREV_FRAME. It just does what
440 the default INIT_FRAME_PC does. Some machines will call it from
441 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
442 Some machines won't use it.
443 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
445 #ifdef INIT_FRAME_PC_FIRST
446 INIT_FRAME_PC_FIRST (fromleaf, prev);
449 #ifdef INIT_EXTRA_FRAME_INFO
450 INIT_EXTRA_FRAME_INFO (fromleaf, prev);
453 /* This entry is in the frame queue now, which is good since
454 FRAME_SAVED_PC may use that queue to figure out its value
455 (see tm-sparc.h). We want the pc saved in the inferior frame. */
456 INIT_FRAME_PC (fromleaf, prev);
458 /* If ->frame and ->pc are unchanged, we are in the process of getting
459 ourselves into an infinite backtrace. Some architectures check this
460 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
461 this can't be an architecture-independent check. */
462 if (next_frame != NULL)
464 if (prev->frame == next_frame->frame
465 && prev->pc == next_frame->pc)
467 next_frame->prev = NULL;
468 obstack_free (&frame_cache_obstack, prev);
473 find_pc_partial_function (prev->pc, &name,
474 (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
475 if (IN_SIGTRAMP (prev->pc, name))
476 prev->signal_handler_caller = 1;
482 get_frame_pc (struct frame_info *frame)
488 #ifdef FRAME_FIND_SAVED_REGS
489 /* XXX - deprecated. This is a compatibility function for targets
490 that do not yet implement FRAME_INIT_SAVED_REGS. */
491 /* Find the addresses in which registers are saved in FRAME. */
494 get_frame_saved_regs (struct frame_info *frame,
495 struct frame_saved_regs *saved_regs_addr)
497 if (frame->saved_regs == NULL)
499 frame->saved_regs = (CORE_ADDR *)
500 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
502 if (saved_regs_addr == NULL)
504 struct frame_saved_regs saved_regs;
505 FRAME_FIND_SAVED_REGS (frame, saved_regs);
506 memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS);
510 FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr);
511 memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS);
516 /* Return the innermost lexical block in execution
517 in a specified stack frame. The frame address is assumed valid. */
520 get_frame_block (struct frame_info *frame)
525 if (frame->next != 0 && frame->next->signal_handler_caller == 0)
526 /* We are not in the innermost frame and we were not interrupted
527 by a signal. We need to subtract one to get the correct block,
528 in case the call instruction was the last instruction of the block.
529 If there are any machines on which the saved pc does not point to
530 after the call insn, we probably want to make frame->pc point after
531 the call insn anyway. */
533 return block_for_pc (pc);
537 get_current_block (void)
539 return block_for_pc (read_pc ());
543 get_pc_function_start (CORE_ADDR pc)
545 register struct block *bl;
546 register struct symbol *symbol;
547 register struct minimal_symbol *msymbol;
550 if ((bl = block_for_pc (pc)) != NULL &&
551 (symbol = block_function (bl)) != NULL)
553 bl = SYMBOL_BLOCK_VALUE (symbol);
554 fstart = BLOCK_START (bl);
556 else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL)
558 fstart = SYMBOL_VALUE_ADDRESS (msymbol);
567 /* Return the symbol for the function executing in frame FRAME. */
570 get_frame_function (struct frame_info *frame)
572 register struct block *bl = get_frame_block (frame);
575 return block_function (bl);
579 /* Return the blockvector immediately containing the innermost lexical block
580 containing the specified pc value and section, or 0 if there is none.
581 PINDEX is a pointer to the index value of the block. If PINDEX
582 is NULL, we don't pass this information back to the caller. */
585 blockvector_for_pc_sect (register CORE_ADDR pc, struct sec *section,
586 int *pindex, struct symtab *symtab)
588 register struct block *b;
589 register int bot, top, half;
590 struct blockvector *bl;
592 if (symtab == 0) /* if no symtab specified by caller */
594 /* First search all symtabs for one whose file contains our pc */
595 if ((symtab = find_pc_sect_symtab (pc, section)) == 0)
599 bl = BLOCKVECTOR (symtab);
600 b = BLOCKVECTOR_BLOCK (bl, 0);
602 /* Then search that symtab for the smallest block that wins. */
603 /* Use binary search to find the last block that starts before PC. */
606 top = BLOCKVECTOR_NBLOCKS (bl);
608 while (top - bot > 1)
610 half = (top - bot + 1) >> 1;
611 b = BLOCKVECTOR_BLOCK (bl, bot + half);
612 if (BLOCK_START (b) <= pc)
618 /* Now search backward for a block that ends after PC. */
622 b = BLOCKVECTOR_BLOCK (bl, bot);
623 if (BLOCK_END (b) > pc)
634 /* Return the blockvector immediately containing the innermost lexical block
635 containing the specified pc value, or 0 if there is none.
636 Backward compatibility, no section. */
639 blockvector_for_pc (register CORE_ADDR pc, int *pindex)
641 return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
645 /* Return the innermost lexical block containing the specified pc value
646 in the specified section, or 0 if there is none. */
649 block_for_pc_sect (register CORE_ADDR pc, struct sec *section)
651 register struct blockvector *bl;
654 bl = blockvector_for_pc_sect (pc, section, &index, NULL);
656 return BLOCKVECTOR_BLOCK (bl, index);
660 /* Return the innermost lexical block containing the specified pc value,
661 or 0 if there is none. Backward compatibility, no section. */
664 block_for_pc (register CORE_ADDR pc)
666 return block_for_pc_sect (pc, find_pc_mapped_section (pc));
669 /* Return the function containing pc value PC in section SECTION.
670 Returns 0 if function is not known. */
673 find_pc_sect_function (CORE_ADDR pc, struct sec *section)
675 register struct block *b = block_for_pc_sect (pc, section);
678 return block_function (b);
681 /* Return the function containing pc value PC.
682 Returns 0 if function is not known. Backward compatibility, no section */
685 find_pc_function (CORE_ADDR pc)
687 return find_pc_sect_function (pc, find_pc_mapped_section (pc));
690 /* These variables are used to cache the most recent result
691 * of find_pc_partial_function. */
693 static CORE_ADDR cache_pc_function_low = 0;
694 static CORE_ADDR cache_pc_function_high = 0;
695 static char *cache_pc_function_name = 0;
696 static struct sec *cache_pc_function_section = NULL;
698 /* Clear cache, e.g. when symbol table is discarded. */
701 clear_pc_function_cache (void)
703 cache_pc_function_low = 0;
704 cache_pc_function_high = 0;
705 cache_pc_function_name = (char *) 0;
706 cache_pc_function_section = NULL;
709 /* Finds the "function" (text symbol) that is smaller than PC but
710 greatest of all of the potential text symbols in SECTION. Sets
711 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
712 If ENDADDR is non-null, then set *ENDADDR to be the end of the
713 function (exclusive), but passing ENDADDR as non-null means that
714 the function might cause symbols to be read. This function either
715 succeeds or fails (not halfway succeeds). If it succeeds, it sets
716 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
717 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
721 find_pc_sect_partial_function (CORE_ADDR pc, asection *section, char **name,
722 CORE_ADDR *address, CORE_ADDR *endaddr)
724 struct partial_symtab *pst;
726 struct minimal_symbol *msymbol;
727 struct partial_symbol *psb;
728 struct obj_section *osect;
732 mapped_pc = overlay_mapped_address (pc, section);
734 if (mapped_pc >= cache_pc_function_low &&
735 mapped_pc < cache_pc_function_high &&
736 section == cache_pc_function_section)
737 goto return_cached_value;
739 /* If sigtramp is in the u area, it counts as a function (especially
740 important for step_1). */
741 #if defined SIGTRAMP_START
742 if (IN_SIGTRAMP (mapped_pc, (char *) NULL))
744 cache_pc_function_low = SIGTRAMP_START (mapped_pc);
745 cache_pc_function_high = SIGTRAMP_END (mapped_pc);
746 cache_pc_function_name = "<sigtramp>";
747 cache_pc_function_section = section;
748 goto return_cached_value;
752 msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section);
753 pst = find_pc_sect_psymtab (mapped_pc, section);
756 /* Need to read the symbols to get a good value for the end address. */
757 if (endaddr != NULL && !pst->readin)
759 /* Need to get the terminal in case symbol-reading produces
761 target_terminal_ours_for_output ();
762 PSYMTAB_TO_SYMTAB (pst);
767 /* Checking whether the msymbol has a larger value is for the
768 "pathological" case mentioned in print_frame_info. */
769 f = find_pc_sect_function (mapped_pc, section);
772 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
773 >= SYMBOL_VALUE_ADDRESS (msymbol))))
775 cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
776 cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
777 cache_pc_function_name = SYMBOL_NAME (f);
778 cache_pc_function_section = section;
779 goto return_cached_value;
784 /* Now that static symbols go in the minimal symbol table, perhaps
785 we could just ignore the partial symbols. But at least for now
786 we use the partial or minimal symbol, whichever is larger. */
787 psb = find_pc_sect_psymbol (pst, mapped_pc, section);
790 && (msymbol == NULL ||
791 (SYMBOL_VALUE_ADDRESS (psb)
792 >= SYMBOL_VALUE_ADDRESS (msymbol))))
794 /* This case isn't being cached currently. */
796 *address = SYMBOL_VALUE_ADDRESS (psb);
798 *name = SYMBOL_NAME (psb);
799 /* endaddr non-NULL can't happen here. */
805 /* Not in the normal symbol tables, see if the pc is in a known section.
806 If it's not, then give up. This ensures that anything beyond the end
807 of the text seg doesn't appear to be part of the last function in the
810 osect = find_pc_sect_section (mapped_pc, section);
815 /* Must be in the minimal symbol table. */
818 /* No available symbol. */
828 cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
829 cache_pc_function_name = SYMBOL_NAME (msymbol);
830 cache_pc_function_section = section;
832 /* Use the lesser of the next minimal symbol in the same section, or
833 the end of the section, as the end of the function. */
835 /* Step over other symbols at this same address, and symbols in
836 other sections, to find the next symbol in this section with
837 a different address. */
839 for (i = 1; SYMBOL_NAME (msymbol + i) != NULL; i++)
841 if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
842 && SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
846 if (SYMBOL_NAME (msymbol + i) != NULL
847 && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
848 cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
850 /* We got the start address from the last msymbol in the objfile.
851 So the end address is the end of the section. */
852 cache_pc_function_high = osect->endaddr;
858 if (pc_in_unmapped_range (pc, section))
859 *address = overlay_unmapped_address (cache_pc_function_low, section);
861 *address = cache_pc_function_low;
865 *name = cache_pc_function_name;
869 if (pc_in_unmapped_range (pc, section))
871 /* Because the high address is actually beyond the end of
872 the function (and therefore possibly beyond the end of
873 the overlay), we must actually convert (high - 1)
874 and then add one to that. */
876 *endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1,
880 *endaddr = cache_pc_function_high;
886 /* Backward compatibility, no section argument */
889 find_pc_partial_function (CORE_ADDR pc, char **name, CORE_ADDR *address,
894 section = find_pc_overlay (pc);
895 return find_pc_sect_partial_function (pc, section, name, address, endaddr);
898 /* Return the innermost stack frame executing inside of BLOCK,
899 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
902 block_innermost_frame (struct block *block)
904 struct frame_info *frame;
905 register CORE_ADDR start;
906 register CORE_ADDR end;
911 start = BLOCK_START (block);
912 end = BLOCK_END (block);
917 frame = get_prev_frame (frame);
920 if (frame->pc >= start && frame->pc < end)
925 /* Return the full FRAME which corresponds to the given CORE_ADDR
926 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
929 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr)
931 struct frame_info *frame = NULL;
933 if (frame_addr == (CORE_ADDR) 0)
938 frame = get_prev_frame (frame);
941 if (FRAME_FP (frame) == frame_addr)
946 #ifdef SIGCONTEXT_PC_OFFSET
947 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
950 sigtramp_saved_pc (struct frame_info *frame)
952 CORE_ADDR sigcontext_addr;
954 int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
955 int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
957 buf = alloca (ptrbytes);
958 /* Get sigcontext address, it is the third parameter on the stack. */
960 sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
965 sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
969 /* Don't cause a memory_error when accessing sigcontext in case the stack
970 layout has changed or the stack is corrupt. */
971 target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
972 return extract_unsigned_integer (buf, ptrbytes);
974 #endif /* SIGCONTEXT_PC_OFFSET */
977 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
978 below is for infrun.c, which may give the macro a pc without that
981 extern CORE_ADDR text_end;
984 pc_in_call_dummy_before_text_end (CORE_ADDR pc, CORE_ADDR sp,
985 CORE_ADDR frame_address)
987 return ((pc) >= text_end - CALL_DUMMY_LENGTH
988 && (pc) <= text_end + DECR_PC_AFTER_BREAK);
992 pc_in_call_dummy_after_text_end (CORE_ADDR pc, CORE_ADDR sp,
993 CORE_ADDR frame_address)
995 return ((pc) >= text_end
996 && (pc) <= text_end + CALL_DUMMY_LENGTH + DECR_PC_AFTER_BREAK);
999 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1000 top of the stack frame which we are checking, where "bottom" and
1001 "top" refer to some section of memory which contains the code for
1002 the call dummy. Calls to this macro assume that the contents of
1003 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1004 are the things to pass.
1006 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1007 have that meaning, but the 29k doesn't use ON_STACK. This could be
1008 fixed by generalizing this scheme, perhaps by passing in a frame
1009 and adding a few fields, at least on machines which need them for
1012 Something simpler, like checking for the stack segment, doesn't work,
1013 since various programs (threads implementations, gcc nested function
1014 stubs, etc) may either allocate stack frames in another segment, or
1015 allocate other kinds of code on the stack. */
1018 pc_in_call_dummy_on_stack (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR frame_address)
1020 return (INNER_THAN ((sp), (pc))
1021 && (frame_address != 0)
1022 && INNER_THAN ((pc), (frame_address)));
1026 pc_in_call_dummy_at_entry_point (CORE_ADDR pc, CORE_ADDR sp,
1027 CORE_ADDR frame_address)
1029 return ((pc) >= CALL_DUMMY_ADDRESS ()
1030 && (pc) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK));
1035 * GENERIC DUMMY FRAMES
1037 * The following code serves to maintain the dummy stack frames for
1038 * inferior function calls (ie. when gdb calls into the inferior via
1039 * call_function_by_hand). This code saves the machine state before
1040 * the call in host memory, so we must maintain an independent stack
1041 * and keep it consistant etc. I am attempting to make this code
1042 * generic enough to be used by many targets.
1044 * The cheapest and most generic way to do CALL_DUMMY on a new target
1045 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1046 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1047 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1048 * being executed by the target. Also FRAME_CHAIN_VALID as
1049 * generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
1050 * generic_fix_call_dummy. */
1052 /* Dummy frame. This saves the processor state just prior to setting
1053 up the inferior function call. Older targets save the registers
1054 on the target stack (but that really slows down function calls). */
1058 struct dummy_frame *next;
1067 static struct dummy_frame *dummy_frame_stack = NULL;
1069 /* Function: find_dummy_frame(pc, fp, sp)
1070 Search the stack of dummy frames for one matching the given PC, FP and SP.
1071 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1074 generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
1076 struct dummy_frame *dummyframe;
1078 if (pc != entry_point_address ())
1081 for (dummyframe = dummy_frame_stack; dummyframe != NULL;
1082 dummyframe = dummyframe->next)
1083 if (fp == dummyframe->fp
1084 || fp == dummyframe->sp
1085 || fp == dummyframe->top)
1086 /* The frame in question lies between the saved fp and sp, inclusive */
1087 return dummyframe->registers;
1092 /* Function: pc_in_call_dummy (pc, fp)
1093 Return true if this is a dummy frame created by gdb for an inferior call */
1096 generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
1098 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1099 /* Note: SP and not FP is passed on. */
1100 return (generic_find_dummy_frame (pc, sp) != 0);
1103 /* Function: read_register_dummy
1104 Find a saved register from before GDB calls a function in the inferior */
1107 generic_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
1109 char *dummy_regs = generic_find_dummy_frame (pc, fp);
1112 return extract_address (&dummy_regs[REGISTER_BYTE (regno)],
1113 REGISTER_RAW_SIZE (regno));
1118 /* Save all the registers on the dummy frame stack. Most ports save the
1119 registers on the target stack. This results in lots of unnecessary memory
1120 references, which are slow when debugging via a serial line. Instead, we
1121 save all the registers internally, and never write them to the stack. The
1122 registers get restored when the called function returns to the entry point,
1123 where a breakpoint is laying in wait. */
1126 generic_push_dummy_frame (void)
1128 struct dummy_frame *dummy_frame;
1129 CORE_ADDR fp = (get_current_frame ())->frame;
1131 /* check to see if there are stale dummy frames,
1132 perhaps left over from when a longjump took us out of a
1133 function that was called by the debugger */
1135 dummy_frame = dummy_frame_stack;
1137 if (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */
1139 dummy_frame_stack = dummy_frame->next;
1140 free (dummy_frame->registers);
1142 dummy_frame = dummy_frame_stack;
1145 dummy_frame = dummy_frame->next;
1147 dummy_frame = xmalloc (sizeof (struct dummy_frame));
1148 dummy_frame->registers = xmalloc (REGISTER_BYTES);
1150 dummy_frame->pc = read_pc ();
1151 dummy_frame->sp = read_sp ();
1152 dummy_frame->top = dummy_frame->sp;
1153 dummy_frame->fp = fp;
1154 read_register_bytes (0, dummy_frame->registers, REGISTER_BYTES);
1155 dummy_frame->next = dummy_frame_stack;
1156 dummy_frame_stack = dummy_frame;
1160 generic_save_dummy_frame_tos (CORE_ADDR sp)
1162 dummy_frame_stack->top = sp;
1165 /* Restore the machine state from either the saved dummy stack or a
1166 real stack frame. */
1169 generic_pop_current_frame (void (*popper) (struct frame_info * frame))
1171 struct frame_info *frame = get_current_frame ();
1173 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
1174 generic_pop_dummy_frame ();
1179 /* Function: pop_dummy_frame
1180 Restore the machine state from a saved dummy stack frame. */
1183 generic_pop_dummy_frame (void)
1185 struct dummy_frame *dummy_frame = dummy_frame_stack;
1187 /* FIXME: what if the first frame isn't the right one, eg..
1188 because one call-by-hand function has done a longjmp into another one? */
1191 error ("Can't pop dummy frame!");
1192 dummy_frame_stack = dummy_frame->next;
1193 write_register_bytes (0, dummy_frame->registers, REGISTER_BYTES);
1194 flush_cached_frames ();
1196 free (dummy_frame->registers);
1200 /* Function: frame_chain_valid
1201 Returns true for a user frame or a call_function_by_hand dummy frame,
1202 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1205 generic_file_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
1207 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi), fp, fp))
1208 return 1; /* don't prune CALL_DUMMY frames */
1209 else /* fall back to default algorithm (see frame.h) */
1211 && (INNER_THAN (fi->frame, fp) || fi->frame == fp)
1212 && !inside_entry_file (FRAME_SAVED_PC (fi)));
1216 generic_func_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
1218 if (PC_IN_CALL_DUMMY ((fi)->pc, fp, fp))
1219 return 1; /* don't prune CALL_DUMMY frames */
1220 else /* fall back to default algorithm (see frame.h) */
1222 && (INNER_THAN (fi->frame, fp) || fi->frame == fp)
1223 && !inside_main_func ((fi)->pc)
1224 && !inside_entry_func ((fi)->pc));
1227 /* Function: fix_call_dummy
1228 Stub function. Generic dumy frames typically do not need to fix
1229 the frame being created */
1232 generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
1233 struct value **args, struct type *type, int gcc_p)
1238 /* Function: get_saved_register
1239 Find register number REGNUM relative to FRAME and put its (raw,
1240 target format) contents in *RAW_BUFFER.
1242 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1243 fetched). Note that this is never set to anything other than zero
1244 in this implementation.
1246 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1247 whether the value was fetched from memory, from a register, or in a
1248 strange and non-modifiable way (e.g. a frame pointer which was
1249 calculated rather than fetched). We will use not_lval for values
1250 fetched from generic dummy frames.
1252 Set *ADDRP to the address, either in memory on as a REGISTER_BYTE
1253 offset into the registers array. If the value is stored in a dummy
1254 frame, set *ADDRP to zero.
1256 To use this implementation, define a function called
1257 "get_saved_register" in your target code, which simply passes all
1258 of its arguments to this function.
1260 The argument RAW_BUFFER must point to aligned memory. */
1263 generic_get_saved_register (char *raw_buffer, int *optimized, CORE_ADDR *addrp,
1264 struct frame_info *frame, int regnum,
1265 enum lval_type *lval)
1267 if (!target_has_registers)
1268 error ("No registers.");
1270 /* Normal systems don't optimize out things with register numbers. */
1271 if (optimized != NULL)
1274 if (addrp) /* default assumption: not found in memory */
1277 /* Note: since the current frame's registers could only have been
1278 saved by frames INTERIOR TO the current frame, we skip examining
1279 the current frame itself: otherwise, we would be getting the
1280 previous frame's registers which were saved by the current frame. */
1282 while (frame && ((frame = frame->next) != NULL))
1284 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
1286 if (lval) /* found it in a CALL_DUMMY frame */
1290 generic_find_dummy_frame (frame->pc, frame->frame) +
1291 REGISTER_BYTE (regnum),
1292 REGISTER_RAW_SIZE (regnum));
1296 FRAME_INIT_SAVED_REGS (frame);
1297 if (frame->saved_regs != NULL
1298 && frame->saved_regs[regnum] != 0)
1300 if (lval) /* found it saved on the stack */
1301 *lval = lval_memory;
1302 if (regnum == SP_REGNUM)
1304 if (raw_buffer) /* SP register treated specially */
1305 store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
1306 frame->saved_regs[regnum]);
1310 if (addrp) /* any other register */
1311 *addrp = frame->saved_regs[regnum];
1313 read_memory (frame->saved_regs[regnum], raw_buffer,
1314 REGISTER_RAW_SIZE (regnum));
1320 /* If we get thru the loop to this point, it means the register was
1321 not saved in any frame. Return the actual live-register value. */
1323 if (lval) /* found it in a live register */
1324 *lval = lval_register;
1326 *addrp = REGISTER_BYTE (regnum);
1328 read_register_gen (regnum, raw_buffer);
1332 _initialize_blockframe (void)
1334 obstack_init (&frame_cache_obstack);