1 /* Get info from stack frames;
2 convert between frames, blocks, functions and pc values.
3 Copyright 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
30 #include "value.h" /* for read_register */
31 #include "target.h" /* for target_has_stack */
32 #include "inferior.h" /* for read_pc */
36 /* Prototypes for exported functions. */
38 void _initialize_blockframe (void);
40 /* A default FRAME_CHAIN_VALID, in the form that is suitable for most
41 targets. If FRAME_CHAIN_VALID returns zero it means that the given
42 frame is the outermost one and has no caller. */
45 file_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
48 && !inside_entry_file (FRAME_SAVED_PC (thisframe)));
51 /* Use the alternate method of avoiding running up off the end of the
52 frame chain or following frames back into the startup code. See
53 the comments in objfiles.h. */
56 func_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
59 && !inside_main_func ((thisframe)->pc)
60 && !inside_entry_func ((thisframe)->pc));
63 /* A very simple method of determining a valid frame */
66 nonnull_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
68 return ((chain) != 0);
71 /* Is ADDR inside the startup file? Note that if your machine
72 has a way to detect the bottom of the stack, there is no need
73 to call this function from FRAME_CHAIN_VALID; the reason for
74 doing so is that some machines have no way of detecting bottom
77 A PC of zero is always considered to be the bottom of the stack. */
80 inside_entry_file (CORE_ADDR addr)
84 if (symfile_objfile == 0)
86 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
88 /* Do not stop backtracing if the pc is in the call dummy
89 at the entry point. */
90 /* FIXME: Won't always work with zeros for the last two arguments */
91 if (PC_IN_CALL_DUMMY (addr, 0, 0))
94 return (addr >= symfile_objfile->ei.entry_file_lowpc &&
95 addr < symfile_objfile->ei.entry_file_highpc);
98 /* Test a specified PC value to see if it is in the range of addresses
99 that correspond to the main() function. See comments above for why
100 we might want to do this.
102 Typically called from FRAME_CHAIN_VALID.
104 A PC of zero is always considered to be the bottom of the stack. */
107 inside_main_func (CORE_ADDR pc)
111 if (symfile_objfile == 0)
114 /* If the addr range is not set up at symbol reading time, set it up now.
115 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
116 it is unable to set it up and symbol reading time. */
118 if (symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC &&
119 symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
121 struct symbol *mainsym;
123 mainsym = lookup_symbol (main_name (), NULL, VAR_NAMESPACE, NULL, NULL);
124 if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
126 symfile_objfile->ei.main_func_lowpc =
127 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
128 symfile_objfile->ei.main_func_highpc =
129 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
132 return (symfile_objfile->ei.main_func_lowpc <= pc &&
133 symfile_objfile->ei.main_func_highpc > pc);
136 /* Test a specified PC value to see if it is in the range of addresses
137 that correspond to the process entry point function. See comments
138 in objfiles.h for why we might want to do this.
140 Typically called from FRAME_CHAIN_VALID.
142 A PC of zero is always considered to be the bottom of the stack. */
145 inside_entry_func (CORE_ADDR pc)
149 if (symfile_objfile == 0)
151 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
153 /* Do not stop backtracing if the pc is in the call dummy
154 at the entry point. */
155 /* FIXME: Won't always work with zeros for the last two arguments */
156 if (PC_IN_CALL_DUMMY (pc, 0, 0))
159 return (symfile_objfile->ei.entry_func_lowpc <= pc &&
160 symfile_objfile->ei.entry_func_highpc > pc);
163 /* Info about the innermost stack frame (contents of FP register) */
165 static struct frame_info *current_frame;
167 /* Cache for frame addresses already read by gdb. Valid only while
168 inferior is stopped. Control variables for the frame cache should
169 be local to this module. */
171 static struct obstack frame_cache_obstack;
174 frame_obstack_alloc (unsigned long size)
176 return obstack_alloc (&frame_cache_obstack, size);
180 frame_saved_regs_zalloc (struct frame_info *fi)
182 fi->saved_regs = (CORE_ADDR *)
183 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
184 memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);
188 /* Return the innermost (currently executing) stack frame. */
191 get_current_frame (void)
193 if (current_frame == NULL)
195 if (target_has_stack)
196 current_frame = create_new_frame (read_fp (), read_pc ());
200 return current_frame;
204 set_current_frame (struct frame_info *frame)
206 current_frame = frame;
209 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
210 Always returns a non-NULL value. */
213 create_new_frame (CORE_ADDR addr, CORE_ADDR pc)
215 struct frame_info *fi;
218 fi = (struct frame_info *)
219 obstack_alloc (&frame_cache_obstack,
220 sizeof (struct frame_info));
222 /* Zero all fields by default. */
223 memset (fi, 0, sizeof (struct frame_info));
227 find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
228 fi->signal_handler_caller = IN_SIGTRAMP (fi->pc, name);
230 if (INIT_EXTRA_FRAME_INFO_P ())
231 INIT_EXTRA_FRAME_INFO (0, fi);
236 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
240 get_next_frame (struct frame_info *frame)
245 /* Flush the entire frame cache. */
248 flush_cached_frames (void)
250 /* Since we can't really be sure what the first object allocated was */
251 obstack_free (&frame_cache_obstack, 0);
252 obstack_init (&frame_cache_obstack);
254 current_frame = NULL; /* Invalidate cache */
255 select_frame (NULL, -1);
256 annotate_frames_invalid ();
259 /* Flush the frame cache, and start a new one if necessary. */
262 reinit_frame_cache (void)
264 flush_cached_frames ();
266 /* FIXME: The inferior_ptid test is wrong if there is a corefile. */
267 if (PIDGET (inferior_ptid) != 0)
269 select_frame (get_current_frame (), 0);
273 /* Return nonzero if the function for this frame lacks a prologue. Many
274 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
278 frameless_look_for_prologue (struct frame_info *frame)
280 CORE_ADDR func_start, after_prologue;
282 func_start = get_pc_function_start (frame->pc);
285 func_start += FUNCTION_START_OFFSET;
286 /* This is faster, since only care whether there *is* a
287 prologue, not how long it is. */
288 return PROLOGUE_FRAMELESS_P (func_start);
290 else if (frame->pc == 0)
291 /* A frame with a zero PC is usually created by dereferencing a
292 NULL function pointer, normally causing an immediate core dump
293 of the inferior. Mark function as frameless, as the inferior
294 has no chance of setting up a stack frame. */
297 /* If we can't find the start of the function, we don't really
298 know whether the function is frameless, but we should be able
299 to get a reasonable (i.e. best we can do under the
300 circumstances) backtrace by saying that it isn't. */
304 /* Default a few macros that people seldom redefine. */
306 #ifndef FRAME_CHAIN_COMBINE
307 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
310 /* Return a structure containing various interesting information
311 about the frame that called NEXT_FRAME. Returns NULL
312 if there is no such frame. */
315 get_prev_frame (struct frame_info *next_frame)
317 CORE_ADDR address = 0;
318 struct frame_info *prev;
322 /* If the requested entry is in the cache, return it.
323 Otherwise, figure out what the address should be for the entry
324 we're about to add to the cache. */
329 /* This screws value_of_variable, which just wants a nice clean
330 NULL return from block_innermost_frame if there are no frames.
331 I don't think I've ever seen this message happen otherwise.
332 And returning NULL here is a perfectly legitimate thing to do. */
335 error ("You haven't set up a process's stack to examine.");
339 return current_frame;
342 /* If we have the prev one, return it */
343 if (next_frame->prev)
344 return next_frame->prev;
346 /* On some machines it is possible to call a function without
347 setting up a stack frame for it. On these machines, we
348 define this macro to take two args; a frameinfo pointer
349 identifying a frame and a variable to set or clear if it is
350 or isn't leafless. */
352 /* Still don't want to worry about this except on the innermost
353 frame. This macro will set FROMLEAF if NEXT_FRAME is a
354 frameless function invocation. */
355 if (!(next_frame->next))
357 fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame);
359 address = FRAME_FP (next_frame);
364 /* Two macros defined in tm.h specify the machine-dependent
365 actions to be performed here.
366 First, get the frame's chain-pointer.
367 If that is zero, the frame is the outermost frame or a leaf
368 called by the outermost frame. This means that if start
369 calls main without a frame, we'll return 0 (which is fine
372 Nope; there's a problem. This also returns when the current
373 routine is a leaf of main. This is unacceptable. We move
374 this to after the ffi test; I'd rather have backtraces from
375 start go curfluy than have an abort called from main not show
377 address = FRAME_CHAIN (next_frame);
378 if (!FRAME_CHAIN_VALID (address, next_frame))
380 address = FRAME_CHAIN_COMBINE (address, next_frame);
385 prev = (struct frame_info *)
386 obstack_alloc (&frame_cache_obstack,
387 sizeof (struct frame_info));
389 /* Zero all fields by default. */
390 memset (prev, 0, sizeof (struct frame_info));
393 next_frame->prev = prev;
394 prev->next = next_frame;
395 prev->frame = address;
397 /* This change should not be needed, FIXME! We should
398 determine whether any targets *need* INIT_FRAME_PC to happen
399 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
400 express what goes on here.
402 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
403 (where the PC is already set up) and here (where it isn't).
404 INIT_FRAME_PC is only called from here, always after
405 INIT_EXTRA_FRAME_INFO.
407 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
408 value (which hasn't been set yet). Some other machines appear to
409 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
411 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
412 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
414 Assuming that some machines need INIT_FRAME_PC after
415 INIT_EXTRA_FRAME_INFO, one possible scheme:
417 SETUP_INNERMOST_FRAME()
418 Default version is just create_new_frame (read_fp ()),
419 read_pc ()). Machines with extra frame info would do that (or the
420 local equivalent) and then set the extra fields.
421 SETUP_ARBITRARY_FRAME(argc, argv)
422 Only change here is that create_new_frame would no longer init extra
423 frame info; SETUP_ARBITRARY_FRAME would have to do that.
424 INIT_PREV_FRAME(fromleaf, prev)
425 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
426 also return a flag saying whether to keep the new frame, or
427 whether to discard it, because on some machines (e.g. mips) it
428 is really awkward to have FRAME_CHAIN_VALID called *before*
429 INIT_EXTRA_FRAME_INFO (there is no good way to get information
430 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
431 std_frame_pc(fromleaf, prev)
432 This is the default setting for INIT_PREV_FRAME. It just does what
433 the default INIT_FRAME_PC does. Some machines will call it from
434 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
435 Some machines won't use it.
436 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
438 INIT_FRAME_PC_FIRST (fromleaf, prev);
440 if (INIT_EXTRA_FRAME_INFO_P ())
441 INIT_EXTRA_FRAME_INFO (fromleaf, prev);
443 /* This entry is in the frame queue now, which is good since
444 FRAME_SAVED_PC may use that queue to figure out its value
445 (see tm-sparc.h). We want the pc saved in the inferior frame. */
446 INIT_FRAME_PC (fromleaf, prev);
448 /* If ->frame and ->pc are unchanged, we are in the process of getting
449 ourselves into an infinite backtrace. Some architectures check this
450 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
451 this can't be an architecture-independent check. */
452 if (next_frame != NULL)
454 if (prev->frame == next_frame->frame
455 && prev->pc == next_frame->pc)
457 next_frame->prev = NULL;
458 obstack_free (&frame_cache_obstack, prev);
463 find_pc_partial_function (prev->pc, &name,
464 (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
465 if (IN_SIGTRAMP (prev->pc, name))
466 prev->signal_handler_caller = 1;
472 get_frame_pc (struct frame_info *frame)
478 #ifdef FRAME_FIND_SAVED_REGS
479 /* XXX - deprecated. This is a compatibility function for targets
480 that do not yet implement FRAME_INIT_SAVED_REGS. */
481 /* Find the addresses in which registers are saved in FRAME. */
484 get_frame_saved_regs (struct frame_info *frame,
485 struct frame_saved_regs *saved_regs_addr)
487 if (frame->saved_regs == NULL)
489 frame->saved_regs = (CORE_ADDR *)
490 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
492 if (saved_regs_addr == NULL)
494 struct frame_saved_regs saved_regs;
495 FRAME_FIND_SAVED_REGS (frame, saved_regs);
496 memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS);
500 FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr);
501 memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS);
506 /* Return the innermost lexical block in execution
507 in a specified stack frame. The frame address is assumed valid.
509 If ADDR_IN_BLOCK is non-zero, set *ADDR_IN_BLOCK to the exact code
510 address we used to choose the block. We use this to find a source
511 line, to decide which macro definitions are in scope.
513 The value returned in *ADDR_IN_BLOCK isn't necessarily the frame's
514 PC, and may not really be a valid PC at all. For example, in the
515 caller of a function declared to never return, the code at the
516 return address will never be reached, so the call instruction may
517 be the very last instruction in the block. So the address we use
518 to choose the block is actually one byte before the return address
519 --- hopefully pointing us at the call instruction, or its delay
523 get_frame_block (struct frame_info *frame, CORE_ADDR *addr_in_block)
528 if (frame->next != 0 && frame->next->signal_handler_caller == 0)
529 /* We are not in the innermost frame and we were not interrupted
530 by a signal. We need to subtract one to get the correct block,
531 in case the call instruction was the last instruction of the block.
532 If there are any machines on which the saved pc does not point to
533 after the call insn, we probably want to make frame->pc point after
534 the call insn anyway. */
540 return block_for_pc (pc);
544 get_current_block (CORE_ADDR *addr_in_block)
546 CORE_ADDR pc = read_pc ();
551 return block_for_pc (pc);
555 get_pc_function_start (CORE_ADDR pc)
557 register struct block *bl;
558 register struct symbol *symbol;
559 register struct minimal_symbol *msymbol;
562 if ((bl = block_for_pc (pc)) != NULL &&
563 (symbol = block_function (bl)) != NULL)
565 bl = SYMBOL_BLOCK_VALUE (symbol);
566 fstart = BLOCK_START (bl);
568 else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL)
570 fstart = SYMBOL_VALUE_ADDRESS (msymbol);
579 /* Return the symbol for the function executing in frame FRAME. */
582 get_frame_function (struct frame_info *frame)
584 register struct block *bl = get_frame_block (frame, 0);
587 return block_function (bl);
591 /* Return the blockvector immediately containing the innermost lexical block
592 containing the specified pc value and section, or 0 if there is none.
593 PINDEX is a pointer to the index value of the block. If PINDEX
594 is NULL, we don't pass this information back to the caller. */
597 blockvector_for_pc_sect (register CORE_ADDR pc, struct sec *section,
598 int *pindex, struct symtab *symtab)
600 register struct block *b;
601 register int bot, top, half;
602 struct blockvector *bl;
604 if (symtab == 0) /* if no symtab specified by caller */
606 /* First search all symtabs for one whose file contains our pc */
607 if ((symtab = find_pc_sect_symtab (pc, section)) == 0)
611 bl = BLOCKVECTOR (symtab);
612 b = BLOCKVECTOR_BLOCK (bl, 0);
614 /* Then search that symtab for the smallest block that wins. */
615 /* Use binary search to find the last block that starts before PC. */
618 top = BLOCKVECTOR_NBLOCKS (bl);
620 while (top - bot > 1)
622 half = (top - bot + 1) >> 1;
623 b = BLOCKVECTOR_BLOCK (bl, bot + half);
624 if (BLOCK_START (b) <= pc)
630 /* Now search backward for a block that ends after PC. */
634 b = BLOCKVECTOR_BLOCK (bl, bot);
635 if (BLOCK_END (b) > pc)
646 /* Return the blockvector immediately containing the innermost lexical block
647 containing the specified pc value, or 0 if there is none.
648 Backward compatibility, no section. */
651 blockvector_for_pc (register CORE_ADDR pc, int *pindex)
653 return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
657 /* Return the innermost lexical block containing the specified pc value
658 in the specified section, or 0 if there is none. */
661 block_for_pc_sect (register CORE_ADDR pc, struct sec *section)
663 register struct blockvector *bl;
666 bl = blockvector_for_pc_sect (pc, section, &index, NULL);
668 return BLOCKVECTOR_BLOCK (bl, index);
672 /* Return the innermost lexical block containing the specified pc value,
673 or 0 if there is none. Backward compatibility, no section. */
676 block_for_pc (register CORE_ADDR pc)
678 return block_for_pc_sect (pc, find_pc_mapped_section (pc));
681 /* Return the function containing pc value PC in section SECTION.
682 Returns 0 if function is not known. */
685 find_pc_sect_function (CORE_ADDR pc, struct sec *section)
687 register struct block *b = block_for_pc_sect (pc, section);
690 return block_function (b);
693 /* Return the function containing pc value PC.
694 Returns 0 if function is not known. Backward compatibility, no section */
697 find_pc_function (CORE_ADDR pc)
699 return find_pc_sect_function (pc, find_pc_mapped_section (pc));
702 /* These variables are used to cache the most recent result
703 * of find_pc_partial_function. */
705 static CORE_ADDR cache_pc_function_low = 0;
706 static CORE_ADDR cache_pc_function_high = 0;
707 static char *cache_pc_function_name = 0;
708 static struct sec *cache_pc_function_section = NULL;
710 /* Clear cache, e.g. when symbol table is discarded. */
713 clear_pc_function_cache (void)
715 cache_pc_function_low = 0;
716 cache_pc_function_high = 0;
717 cache_pc_function_name = (char *) 0;
718 cache_pc_function_section = NULL;
721 /* Finds the "function" (text symbol) that is smaller than PC but
722 greatest of all of the potential text symbols in SECTION. Sets
723 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
724 If ENDADDR is non-null, then set *ENDADDR to be the end of the
725 function (exclusive), but passing ENDADDR as non-null means that
726 the function might cause symbols to be read. This function either
727 succeeds or fails (not halfway succeeds). If it succeeds, it sets
728 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
729 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
733 find_pc_sect_partial_function (CORE_ADDR pc, asection *section, char **name,
734 CORE_ADDR *address, CORE_ADDR *endaddr)
736 struct partial_symtab *pst;
738 struct minimal_symbol *msymbol;
739 struct partial_symbol *psb;
740 struct obj_section *osect;
744 mapped_pc = overlay_mapped_address (pc, section);
746 if (mapped_pc >= cache_pc_function_low &&
747 mapped_pc < cache_pc_function_high &&
748 section == cache_pc_function_section)
749 goto return_cached_value;
751 /* If sigtramp is in the u area, it counts as a function (especially
752 important for step_1). */
753 #if defined SIGTRAMP_START
754 if (IN_SIGTRAMP (mapped_pc, (char *) NULL))
756 cache_pc_function_low = SIGTRAMP_START (mapped_pc);
757 cache_pc_function_high = SIGTRAMP_END (mapped_pc);
758 cache_pc_function_name = "<sigtramp>";
759 cache_pc_function_section = section;
760 goto return_cached_value;
764 msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section);
765 pst = find_pc_sect_psymtab (mapped_pc, section);
768 /* Need to read the symbols to get a good value for the end address. */
769 if (endaddr != NULL && !pst->readin)
771 /* Need to get the terminal in case symbol-reading produces
773 target_terminal_ours_for_output ();
774 PSYMTAB_TO_SYMTAB (pst);
779 /* Checking whether the msymbol has a larger value is for the
780 "pathological" case mentioned in print_frame_info. */
781 f = find_pc_sect_function (mapped_pc, section);
784 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
785 >= SYMBOL_VALUE_ADDRESS (msymbol))))
787 cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
788 cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
789 cache_pc_function_name = SYMBOL_NAME (f);
790 cache_pc_function_section = section;
791 goto return_cached_value;
796 /* Now that static symbols go in the minimal symbol table, perhaps
797 we could just ignore the partial symbols. But at least for now
798 we use the partial or minimal symbol, whichever is larger. */
799 psb = find_pc_sect_psymbol (pst, mapped_pc, section);
802 && (msymbol == NULL ||
803 (SYMBOL_VALUE_ADDRESS (psb)
804 >= SYMBOL_VALUE_ADDRESS (msymbol))))
806 /* This case isn't being cached currently. */
808 *address = SYMBOL_VALUE_ADDRESS (psb);
810 *name = SYMBOL_NAME (psb);
811 /* endaddr non-NULL can't happen here. */
817 /* Not in the normal symbol tables, see if the pc is in a known section.
818 If it's not, then give up. This ensures that anything beyond the end
819 of the text seg doesn't appear to be part of the last function in the
822 osect = find_pc_sect_section (mapped_pc, section);
827 /* Must be in the minimal symbol table. */
830 /* No available symbol. */
840 cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
841 cache_pc_function_name = SYMBOL_NAME (msymbol);
842 cache_pc_function_section = section;
844 /* Use the lesser of the next minimal symbol in the same section, or
845 the end of the section, as the end of the function. */
847 /* Step over other symbols at this same address, and symbols in
848 other sections, to find the next symbol in this section with
849 a different address. */
851 for (i = 1; SYMBOL_NAME (msymbol + i) != NULL; i++)
853 if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
854 && SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
858 if (SYMBOL_NAME (msymbol + i) != NULL
859 && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
860 cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
862 /* We got the start address from the last msymbol in the objfile.
863 So the end address is the end of the section. */
864 cache_pc_function_high = osect->endaddr;
870 if (pc_in_unmapped_range (pc, section))
871 *address = overlay_unmapped_address (cache_pc_function_low, section);
873 *address = cache_pc_function_low;
877 *name = cache_pc_function_name;
881 if (pc_in_unmapped_range (pc, section))
883 /* Because the high address is actually beyond the end of
884 the function (and therefore possibly beyond the end of
885 the overlay), we must actually convert (high - 1)
886 and then add one to that. */
888 *endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1,
892 *endaddr = cache_pc_function_high;
898 /* Backward compatibility, no section argument */
901 find_pc_partial_function (CORE_ADDR pc, char **name, CORE_ADDR *address,
906 section = find_pc_overlay (pc);
907 return find_pc_sect_partial_function (pc, section, name, address, endaddr);
910 /* Return the innermost stack frame executing inside of BLOCK,
911 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
914 block_innermost_frame (struct block *block)
916 struct frame_info *frame;
917 register CORE_ADDR start;
918 register CORE_ADDR end;
923 start = BLOCK_START (block);
924 end = BLOCK_END (block);
929 frame = get_prev_frame (frame);
932 if (frame->pc >= start && frame->pc < end)
937 /* Return the full FRAME which corresponds to the given CORE_ADDR
938 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
941 find_frame_addr_in_frame_chain (CORE_ADDR frame_addr)
943 struct frame_info *frame = NULL;
945 if (frame_addr == (CORE_ADDR) 0)
950 frame = get_prev_frame (frame);
953 if (FRAME_FP (frame) == frame_addr)
958 #ifdef SIGCONTEXT_PC_OFFSET
959 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
962 sigtramp_saved_pc (struct frame_info *frame)
964 CORE_ADDR sigcontext_addr;
966 int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
967 int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
969 buf = alloca (ptrbytes);
970 /* Get sigcontext address, it is the third parameter on the stack. */
972 sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
977 sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
981 /* Don't cause a memory_error when accessing sigcontext in case the stack
982 layout has changed or the stack is corrupt. */
983 target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
984 return extract_unsigned_integer (buf, ptrbytes);
986 #endif /* SIGCONTEXT_PC_OFFSET */
989 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
990 below is for infrun.c, which may give the macro a pc without that
993 extern CORE_ADDR text_end;
996 pc_in_call_dummy_before_text_end (CORE_ADDR pc, CORE_ADDR sp,
997 CORE_ADDR frame_address)
999 return ((pc) >= text_end - CALL_DUMMY_LENGTH
1000 && (pc) <= text_end + DECR_PC_AFTER_BREAK);
1004 pc_in_call_dummy_after_text_end (CORE_ADDR pc, CORE_ADDR sp,
1005 CORE_ADDR frame_address)
1007 return ((pc) >= text_end
1008 && (pc) <= text_end + CALL_DUMMY_LENGTH + DECR_PC_AFTER_BREAK);
1011 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1012 top of the stack frame which we are checking, where "bottom" and
1013 "top" refer to some section of memory which contains the code for
1014 the call dummy. Calls to this macro assume that the contents of
1015 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1016 are the things to pass.
1018 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1019 have that meaning, but the 29k doesn't use ON_STACK. This could be
1020 fixed by generalizing this scheme, perhaps by passing in a frame
1021 and adding a few fields, at least on machines which need them for
1024 Something simpler, like checking for the stack segment, doesn't work,
1025 since various programs (threads implementations, gcc nested function
1026 stubs, etc) may either allocate stack frames in another segment, or
1027 allocate other kinds of code on the stack. */
1030 pc_in_call_dummy_on_stack (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR frame_address)
1032 return (INNER_THAN ((sp), (pc))
1033 && (frame_address != 0)
1034 && INNER_THAN ((pc), (frame_address)));
1038 pc_in_call_dummy_at_entry_point (CORE_ADDR pc, CORE_ADDR sp,
1039 CORE_ADDR frame_address)
1041 return ((pc) >= CALL_DUMMY_ADDRESS ()
1042 && (pc) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK));
1047 * GENERIC DUMMY FRAMES
1049 * The following code serves to maintain the dummy stack frames for
1050 * inferior function calls (ie. when gdb calls into the inferior via
1051 * call_function_by_hand). This code saves the machine state before
1052 * the call in host memory, so we must maintain an independent stack
1053 * and keep it consistant etc. I am attempting to make this code
1054 * generic enough to be used by many targets.
1056 * The cheapest and most generic way to do CALL_DUMMY on a new target
1057 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1058 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1059 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1060 * being executed by the target. Also FRAME_CHAIN_VALID as
1061 * generic_{file,func}_frame_chain_valid and FIX_CALL_DUMMY as
1062 * generic_fix_call_dummy. */
1064 /* Dummy frame. This saves the processor state just prior to setting
1065 up the inferior function call. Older targets save the registers
1066 on the target stack (but that really slows down function calls). */
1070 struct dummy_frame *next;
1079 static struct dummy_frame *dummy_frame_stack = NULL;
1081 /* Function: find_dummy_frame(pc, fp, sp)
1082 Search the stack of dummy frames for one matching the given PC, FP and SP.
1083 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1086 generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp)
1088 struct dummy_frame *dummyframe;
1090 if (pc != entry_point_address ())
1093 for (dummyframe = dummy_frame_stack; dummyframe != NULL;
1094 dummyframe = dummyframe->next)
1095 if (fp == dummyframe->fp
1096 || fp == dummyframe->sp
1097 || fp == dummyframe->top)
1098 /* The frame in question lies between the saved fp and sp, inclusive */
1099 return dummyframe->registers;
1104 /* Function: pc_in_call_dummy (pc, fp)
1105 Return true if this is a dummy frame created by gdb for an inferior call */
1108 generic_pc_in_call_dummy (CORE_ADDR pc, CORE_ADDR sp, CORE_ADDR fp)
1110 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1111 /* Note: SP and not FP is passed on. */
1112 return (generic_find_dummy_frame (pc, sp) != 0);
1115 /* Function: read_register_dummy
1116 Find a saved register from before GDB calls a function in the inferior */
1119 generic_read_register_dummy (CORE_ADDR pc, CORE_ADDR fp, int regno)
1121 char *dummy_regs = generic_find_dummy_frame (pc, fp);
1124 return extract_address (&dummy_regs[REGISTER_BYTE (regno)],
1125 REGISTER_RAW_SIZE (regno));
1130 /* Save all the registers on the dummy frame stack. Most ports save the
1131 registers on the target stack. This results in lots of unnecessary memory
1132 references, which are slow when debugging via a serial line. Instead, we
1133 save all the registers internally, and never write them to the stack. The
1134 registers get restored when the called function returns to the entry point,
1135 where a breakpoint is laying in wait. */
1138 generic_push_dummy_frame (void)
1140 struct dummy_frame *dummy_frame;
1141 CORE_ADDR fp = (get_current_frame ())->frame;
1143 /* check to see if there are stale dummy frames,
1144 perhaps left over from when a longjump took us out of a
1145 function that was called by the debugger */
1147 dummy_frame = dummy_frame_stack;
1149 if (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */
1151 dummy_frame_stack = dummy_frame->next;
1152 xfree (dummy_frame->registers);
1153 xfree (dummy_frame);
1154 dummy_frame = dummy_frame_stack;
1157 dummy_frame = dummy_frame->next;
1159 dummy_frame = xmalloc (sizeof (struct dummy_frame));
1160 dummy_frame->registers = xmalloc (REGISTER_BYTES);
1162 dummy_frame->pc = read_pc ();
1163 dummy_frame->sp = read_sp ();
1164 dummy_frame->top = dummy_frame->sp;
1165 dummy_frame->fp = fp;
1166 read_register_bytes (0, dummy_frame->registers, REGISTER_BYTES);
1167 dummy_frame->next = dummy_frame_stack;
1168 dummy_frame_stack = dummy_frame;
1172 generic_save_dummy_frame_tos (CORE_ADDR sp)
1174 dummy_frame_stack->top = sp;
1177 /* Restore the machine state from either the saved dummy stack or a
1178 real stack frame. */
1181 generic_pop_current_frame (void (*popper) (struct frame_info * frame))
1183 struct frame_info *frame = get_current_frame ();
1185 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
1186 generic_pop_dummy_frame ();
1191 /* Function: pop_dummy_frame
1192 Restore the machine state from a saved dummy stack frame. */
1195 generic_pop_dummy_frame (void)
1197 struct dummy_frame *dummy_frame = dummy_frame_stack;
1199 /* FIXME: what if the first frame isn't the right one, eg..
1200 because one call-by-hand function has done a longjmp into another one? */
1203 error ("Can't pop dummy frame!");
1204 dummy_frame_stack = dummy_frame->next;
1205 write_register_bytes (0, dummy_frame->registers, REGISTER_BYTES);
1206 flush_cached_frames ();
1208 xfree (dummy_frame->registers);
1209 xfree (dummy_frame);
1212 /* Function: frame_chain_valid
1213 Returns true for a user frame or a call_function_by_hand dummy frame,
1214 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1217 generic_file_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
1219 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi), fp, fp))
1220 return 1; /* don't prune CALL_DUMMY frames */
1221 else /* fall back to default algorithm (see frame.h) */
1223 && (INNER_THAN (fi->frame, fp) || fi->frame == fp)
1224 && !inside_entry_file (FRAME_SAVED_PC (fi)));
1228 generic_func_frame_chain_valid (CORE_ADDR fp, struct frame_info *fi)
1230 if (PC_IN_CALL_DUMMY ((fi)->pc, fp, fp))
1231 return 1; /* don't prune CALL_DUMMY frames */
1232 else /* fall back to default algorithm (see frame.h) */
1234 && (INNER_THAN (fi->frame, fp) || fi->frame == fp)
1235 && !inside_main_func ((fi)->pc)
1236 && !inside_entry_func ((fi)->pc));
1239 /* Function: fix_call_dummy
1240 Stub function. Generic dummy frames typically do not need to fix
1241 the frame being created */
1244 generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
1245 struct value **args, struct type *type, int gcc_p)
1250 /* Function: get_saved_register
1251 Find register number REGNUM relative to FRAME and put its (raw,
1252 target format) contents in *RAW_BUFFER.
1254 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1255 fetched). Note that this is never set to anything other than zero
1256 in this implementation.
1258 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1259 whether the value was fetched from memory, from a register, or in a
1260 strange and non-modifiable way (e.g. a frame pointer which was
1261 calculated rather than fetched). We will use not_lval for values
1262 fetched from generic dummy frames.
1264 Set *ADDRP to the address, either in memory or as a REGISTER_BYTE
1265 offset into the registers array. If the value is stored in a dummy
1266 frame, set *ADDRP to zero.
1268 To use this implementation, define a function called
1269 "get_saved_register" in your target code, which simply passes all
1270 of its arguments to this function.
1272 The argument RAW_BUFFER must point to aligned memory. */
1275 generic_get_saved_register (char *raw_buffer, int *optimized, CORE_ADDR *addrp,
1276 struct frame_info *frame, int regnum,
1277 enum lval_type *lval)
1279 if (!target_has_registers)
1280 error ("No registers.");
1282 /* Normal systems don't optimize out things with register numbers. */
1283 if (optimized != NULL)
1286 if (addrp) /* default assumption: not found in memory */
1289 /* Note: since the current frame's registers could only have been
1290 saved by frames INTERIOR TO the current frame, we skip examining
1291 the current frame itself: otherwise, we would be getting the
1292 previous frame's registers which were saved by the current frame. */
1294 while (frame && ((frame = frame->next) != NULL))
1296 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
1298 if (lval) /* found it in a CALL_DUMMY frame */
1302 generic_find_dummy_frame (frame->pc, frame->frame) +
1303 REGISTER_BYTE (regnum),
1304 REGISTER_RAW_SIZE (regnum));
1308 FRAME_INIT_SAVED_REGS (frame);
1309 if (frame->saved_regs != NULL
1310 && frame->saved_regs[regnum] != 0)
1312 if (lval) /* found it saved on the stack */
1313 *lval = lval_memory;
1314 if (regnum == SP_REGNUM)
1316 if (raw_buffer) /* SP register treated specially */
1317 store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
1318 frame->saved_regs[regnum]);
1322 if (addrp) /* any other register */
1323 *addrp = frame->saved_regs[regnum];
1325 read_memory (frame->saved_regs[regnum], raw_buffer,
1326 REGISTER_RAW_SIZE (regnum));
1332 /* If we get thru the loop to this point, it means the register was
1333 not saved in any frame. Return the actual live-register value. */
1335 if (lval) /* found it in a live register */
1336 *lval = lval_register;
1338 *addrp = REGISTER_BYTE (regnum);
1340 read_register_gen (regnum, raw_buffer);
1344 _initialize_blockframe (void)
1346 obstack_init (&frame_cache_obstack);