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 PARAMS ((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 default_frame_chain_valid (chain, thisframe)
46 struct frame_info *thisframe;
49 && !inside_main_func ((thisframe)->pc)
50 && !inside_entry_func ((thisframe)->pc));
53 /* Use the alternate method of avoiding running up off the end of the
54 frame chain or following frames back into the startup code. See
55 the comments in objfiles.h. */
58 alternate_frame_chain_valid (chain, thisframe)
60 struct frame_info *thisframe;
63 && !inside_entry_file (FRAME_SAVED_PC (thisframe)));
66 /* A very simple method of determining a valid frame */
69 nonnull_frame_chain_valid (chain, thisframe)
71 struct frame_info *thisframe;
73 return ((chain) != 0);
76 /* Is ADDR inside the startup file? Note that if your machine
77 has a way to detect the bottom of the stack, there is no need
78 to call this function from FRAME_CHAIN_VALID; the reason for
79 doing so is that some machines have no way of detecting bottom
82 A PC of zero is always considered to be the bottom of the stack. */
85 inside_entry_file (addr)
90 if (symfile_objfile == 0)
92 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
94 /* Do not stop backtracing if the pc is in the call dummy
95 at the entry point. */
96 /* FIXME: Won't always work with zeros for the last two arguments */
97 if (PC_IN_CALL_DUMMY (addr, 0, 0))
100 return (addr >= symfile_objfile->ei.entry_file_lowpc &&
101 addr < symfile_objfile->ei.entry_file_highpc);
104 /* Test a specified PC value to see if it is in the range of addresses
105 that correspond to the main() function. See comments above for why
106 we might want to do this.
108 Typically called from FRAME_CHAIN_VALID.
110 A PC of zero is always considered to be the bottom of the stack. */
113 inside_main_func (pc)
118 if (symfile_objfile == 0)
121 /* If the addr range is not set up at symbol reading time, set it up now.
122 This is for FRAME_CHAIN_VALID_ALTERNATE. I do this for coff, because
123 it is unable to set it up and symbol reading time. */
125 if (symfile_objfile->ei.main_func_lowpc == INVALID_ENTRY_LOWPC &&
126 symfile_objfile->ei.main_func_highpc == INVALID_ENTRY_HIGHPC)
128 struct symbol *mainsym;
130 mainsym = lookup_symbol ("main", NULL, VAR_NAMESPACE, NULL, NULL);
131 if (mainsym && SYMBOL_CLASS (mainsym) == LOC_BLOCK)
133 symfile_objfile->ei.main_func_lowpc =
134 BLOCK_START (SYMBOL_BLOCK_VALUE (mainsym));
135 symfile_objfile->ei.main_func_highpc =
136 BLOCK_END (SYMBOL_BLOCK_VALUE (mainsym));
139 return (symfile_objfile->ei.main_func_lowpc <= pc &&
140 symfile_objfile->ei.main_func_highpc > pc);
143 /* Test a specified PC value to see if it is in the range of addresses
144 that correspond to the process entry point function. See comments
145 in objfiles.h for why we might want to do this.
147 Typically called from FRAME_CHAIN_VALID.
149 A PC of zero is always considered to be the bottom of the stack. */
152 inside_entry_func (pc)
157 if (symfile_objfile == 0)
159 if (CALL_DUMMY_LOCATION == AT_ENTRY_POINT)
161 /* Do not stop backtracing if the pc is in the call dummy
162 at the entry point. */
163 /* FIXME: Won't always work with zeros for the last two arguments */
164 if (PC_IN_CALL_DUMMY (pc, 0, 0))
167 return (symfile_objfile->ei.entry_func_lowpc <= pc &&
168 symfile_objfile->ei.entry_func_highpc > pc);
171 /* Info about the innermost stack frame (contents of FP register) */
173 static struct frame_info *current_frame;
175 /* Cache for frame addresses already read by gdb. Valid only while
176 inferior is stopped. Control variables for the frame cache should
177 be local to this module. */
179 static struct obstack frame_cache_obstack;
182 frame_obstack_alloc (size)
185 return obstack_alloc (&frame_cache_obstack, size);
189 frame_saved_regs_zalloc (fi)
190 struct frame_info *fi;
192 fi->saved_regs = (CORE_ADDR *)
193 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
194 memset (fi->saved_regs, 0, SIZEOF_FRAME_SAVED_REGS);
198 /* Return the innermost (currently executing) stack frame. */
203 if (current_frame == NULL)
205 if (target_has_stack)
206 current_frame = create_new_frame (read_fp (), read_pc ());
210 return current_frame;
214 set_current_frame (frame)
215 struct frame_info *frame;
217 current_frame = frame;
220 /* Create an arbitrary (i.e. address specified by user) or innermost frame.
221 Always returns a non-NULL value. */
224 create_new_frame (addr, pc)
228 struct frame_info *fi;
231 fi = (struct frame_info *)
232 obstack_alloc (&frame_cache_obstack,
233 sizeof (struct frame_info));
235 /* Arbitrary frame */
236 fi->saved_regs = NULL;
241 find_pc_partial_function (pc, &name, (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
242 fi->signal_handler_caller = IN_SIGTRAMP (fi->pc, name);
244 #ifdef INIT_EXTRA_FRAME_INFO
245 INIT_EXTRA_FRAME_INFO (0, fi);
251 /* Return the frame that FRAME calls (NULL if FRAME is the innermost
255 get_next_frame (frame)
256 struct frame_info *frame;
261 /* Flush the entire frame cache. */
264 flush_cached_frames ()
266 /* Since we can't really be sure what the first object allocated was */
267 obstack_free (&frame_cache_obstack, 0);
268 obstack_init (&frame_cache_obstack);
270 current_frame = NULL; /* Invalidate cache */
271 select_frame (NULL, -1);
272 annotate_frames_invalid ();
275 /* Flush the frame cache, and start a new one if necessary. */
278 reinit_frame_cache ()
280 flush_cached_frames ();
282 /* FIXME: The inferior_pid test is wrong if there is a corefile. */
283 if (inferior_pid != 0)
285 select_frame (get_current_frame (), 0);
289 /* If a machine allows frameless functions, it should define a macro
290 FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) in param.h. FI is the struct
291 frame_info for the frame, and FRAMELESS should be set to nonzero
292 if it represents a frameless function invocation. */
294 /* Return nonzero if the function for this frame lacks a prologue. Many
295 machines can define FRAMELESS_FUNCTION_INVOCATION to just call this
299 frameless_look_for_prologue (frame)
300 struct frame_info *frame;
302 CORE_ADDR func_start, after_prologue;
303 func_start = get_pc_function_start (frame->pc);
306 func_start += FUNCTION_START_OFFSET;
307 after_prologue = func_start;
308 #ifdef SKIP_PROLOGUE_FRAMELESS_P
309 /* This is faster, since only care whether there *is* a prologue,
310 not how long it is. */
311 after_prologue = SKIP_PROLOGUE_FRAMELESS_P (after_prologue);
313 after_prologue = SKIP_PROLOGUE (after_prologue);
315 return after_prologue == func_start;
317 else if (frame->pc == 0)
318 /* A frame with a zero PC is usually created by dereferencing a NULL
319 function pointer, normally causing an immediate core dump of the
320 inferior. Mark function as frameless, as the inferior has no chance
321 of setting up a stack frame. */
324 /* If we can't find the start of the function, we don't really
325 know whether the function is frameless, but we should be able
326 to get a reasonable (i.e. best we can do under the
327 circumstances) backtrace by saying that it isn't. */
331 /* Default a few macros that people seldom redefine. */
333 #if !defined (INIT_FRAME_PC)
334 #define INIT_FRAME_PC(fromleaf, prev) \
335 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
336 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
339 #ifndef FRAME_CHAIN_COMBINE
340 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
343 /* Return a structure containing various interesting information
344 about the frame that called NEXT_FRAME. Returns NULL
345 if there is no such frame. */
348 get_prev_frame (next_frame)
349 struct frame_info *next_frame;
351 CORE_ADDR address = 0;
352 struct frame_info *prev;
356 /* If the requested entry is in the cache, return it.
357 Otherwise, figure out what the address should be for the entry
358 we're about to add to the cache. */
363 /* This screws value_of_variable, which just wants a nice clean
364 NULL return from block_innermost_frame if there are no frames.
365 I don't think I've ever seen this message happen otherwise.
366 And returning NULL here is a perfectly legitimate thing to do. */
369 error ("You haven't set up a process's stack to examine.");
373 return current_frame;
376 /* If we have the prev one, return it */
377 if (next_frame->prev)
378 return next_frame->prev;
380 /* On some machines it is possible to call a function without
381 setting up a stack frame for it. On these machines, we
382 define this macro to take two args; a frameinfo pointer
383 identifying a frame and a variable to set or clear if it is
384 or isn't leafless. */
386 /* Still don't want to worry about this except on the innermost
387 frame. This macro will set FROMLEAF if NEXT_FRAME is a
388 frameless function invocation. */
389 if (!(next_frame->next))
391 fromleaf = FRAMELESS_FUNCTION_INVOCATION (next_frame);
393 address = FRAME_FP (next_frame);
398 /* Two macros defined in tm.h specify the machine-dependent
399 actions to be performed here.
400 First, get the frame's chain-pointer.
401 If that is zero, the frame is the outermost frame or a leaf
402 called by the outermost frame. This means that if start
403 calls main without a frame, we'll return 0 (which is fine
406 Nope; there's a problem. This also returns when the current
407 routine is a leaf of main. This is unacceptable. We move
408 this to after the ffi test; I'd rather have backtraces from
409 start go curfluy than have an abort called from main not show
411 address = FRAME_CHAIN (next_frame);
412 if (!FRAME_CHAIN_VALID (address, next_frame))
414 address = FRAME_CHAIN_COMBINE (address, next_frame);
419 prev = (struct frame_info *)
420 obstack_alloc (&frame_cache_obstack,
421 sizeof (struct frame_info));
423 prev->saved_regs = NULL;
425 next_frame->prev = prev;
426 prev->next = next_frame;
427 prev->prev = (struct frame_info *) 0;
428 prev->frame = address;
429 prev->signal_handler_caller = 0;
431 /* This change should not be needed, FIXME! We should
432 determine whether any targets *need* INIT_FRAME_PC to happen
433 after INIT_EXTRA_FRAME_INFO and come up with a simple way to
434 express what goes on here.
436 INIT_EXTRA_FRAME_INFO is called from two places: create_new_frame
437 (where the PC is already set up) and here (where it isn't).
438 INIT_FRAME_PC is only called from here, always after
439 INIT_EXTRA_FRAME_INFO.
441 The catch is the MIPS, where INIT_EXTRA_FRAME_INFO requires the PC
442 value (which hasn't been set yet). Some other machines appear to
443 require INIT_EXTRA_FRAME_INFO before they can do INIT_FRAME_PC. Phoo.
445 We shouldn't need INIT_FRAME_PC_FIRST to add more complication to
446 an already overcomplicated part of GDB. gnu@cygnus.com, 15Sep92.
448 Assuming that some machines need INIT_FRAME_PC after
449 INIT_EXTRA_FRAME_INFO, one possible scheme:
451 SETUP_INNERMOST_FRAME()
452 Default version is just create_new_frame (read_fp ()),
453 read_pc ()). Machines with extra frame info would do that (or the
454 local equivalent) and then set the extra fields.
455 SETUP_ARBITRARY_FRAME(argc, argv)
456 Only change here is that create_new_frame would no longer init extra
457 frame info; SETUP_ARBITRARY_FRAME would have to do that.
458 INIT_PREV_FRAME(fromleaf, prev)
459 Replace INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC. This should
460 also return a flag saying whether to keep the new frame, or
461 whether to discard it, because on some machines (e.g. mips) it
462 is really awkward to have FRAME_CHAIN_VALID called *before*
463 INIT_EXTRA_FRAME_INFO (there is no good way to get information
464 deduced in FRAME_CHAIN_VALID into the extra fields of the new frame).
465 std_frame_pc(fromleaf, prev)
466 This is the default setting for INIT_PREV_FRAME. It just does what
467 the default INIT_FRAME_PC does. Some machines will call it from
468 INIT_PREV_FRAME (either at the beginning, the end, or in the middle).
469 Some machines won't use it.
470 kingdon@cygnus.com, 13Apr93, 31Jan94, 14Dec94. */
472 #ifdef INIT_FRAME_PC_FIRST
473 INIT_FRAME_PC_FIRST (fromleaf, prev);
476 #ifdef INIT_EXTRA_FRAME_INFO
477 INIT_EXTRA_FRAME_INFO (fromleaf, prev);
480 /* This entry is in the frame queue now, which is good since
481 FRAME_SAVED_PC may use that queue to figure out its value
482 (see tm-sparc.h). We want the pc saved in the inferior frame. */
483 INIT_FRAME_PC (fromleaf, prev);
485 /* If ->frame and ->pc are unchanged, we are in the process of getting
486 ourselves into an infinite backtrace. Some architectures check this
487 in FRAME_CHAIN or thereabouts, but it seems like there is no reason
488 this can't be an architecture-independent check. */
489 if (next_frame != NULL)
491 if (prev->frame == next_frame->frame
492 && prev->pc == next_frame->pc)
494 next_frame->prev = NULL;
495 obstack_free (&frame_cache_obstack, prev);
500 find_pc_partial_function (prev->pc, &name,
501 (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
502 if (IN_SIGTRAMP (prev->pc, name))
503 prev->signal_handler_caller = 1;
510 struct frame_info *frame;
516 #ifdef FRAME_FIND_SAVED_REGS
517 /* XXX - deprecated. This is a compatibility function for targets
518 that do not yet implement FRAME_INIT_SAVED_REGS. */
519 /* Find the addresses in which registers are saved in FRAME. */
522 get_frame_saved_regs (frame, saved_regs_addr)
523 struct frame_info *frame;
524 struct frame_saved_regs *saved_regs_addr;
526 if (frame->saved_regs == NULL)
528 frame->saved_regs = (CORE_ADDR *)
529 frame_obstack_alloc (SIZEOF_FRAME_SAVED_REGS);
531 if (saved_regs_addr == NULL)
533 struct frame_saved_regs saved_regs;
534 FRAME_FIND_SAVED_REGS (frame, saved_regs);
535 memcpy (frame->saved_regs, &saved_regs, SIZEOF_FRAME_SAVED_REGS);
539 FRAME_FIND_SAVED_REGS (frame, *saved_regs_addr);
540 memcpy (frame->saved_regs, saved_regs_addr, SIZEOF_FRAME_SAVED_REGS);
545 /* Return the innermost lexical block in execution
546 in a specified stack frame. The frame address is assumed valid. */
549 get_frame_block (frame)
550 struct frame_info *frame;
555 if (frame->next != 0 && frame->next->signal_handler_caller == 0)
556 /* We are not in the innermost frame and we were not interrupted
557 by a signal. We need to subtract one to get the correct block,
558 in case the call instruction was the last instruction of the block.
559 If there are any machines on which the saved pc does not point to
560 after the call insn, we probably want to make frame->pc point after
561 the call insn anyway. */
563 return block_for_pc (pc);
569 return block_for_pc (read_pc ());
573 get_pc_function_start (pc)
576 register struct block *bl;
577 register struct symbol *symbol;
578 register struct minimal_symbol *msymbol;
581 if ((bl = block_for_pc (pc)) != NULL &&
582 (symbol = block_function (bl)) != NULL)
584 bl = SYMBOL_BLOCK_VALUE (symbol);
585 fstart = BLOCK_START (bl);
587 else if ((msymbol = lookup_minimal_symbol_by_pc (pc)) != NULL)
589 fstart = SYMBOL_VALUE_ADDRESS (msymbol);
598 /* Return the symbol for the function executing in frame FRAME. */
601 get_frame_function (frame)
602 struct frame_info *frame;
604 register struct block *bl = get_frame_block (frame);
607 return block_function (bl);
611 /* Return the blockvector immediately containing the innermost lexical block
612 containing the specified pc value and section, or 0 if there is none.
613 PINDEX is a pointer to the index value of the block. If PINDEX
614 is NULL, we don't pass this information back to the caller. */
617 blockvector_for_pc_sect (pc, section, pindex, symtab)
618 register CORE_ADDR pc;
621 struct symtab *symtab;
624 register struct block *b;
625 register int bot, top, half;
626 struct blockvector *bl;
628 if (symtab == 0) /* if no symtab specified by caller */
630 /* First search all symtabs for one whose file contains our pc */
631 if ((symtab = find_pc_sect_symtab (pc, section)) == 0)
635 bl = BLOCKVECTOR (symtab);
636 b = BLOCKVECTOR_BLOCK (bl, 0);
638 /* Then search that symtab for the smallest block that wins. */
639 /* Use binary search to find the last block that starts before PC. */
642 top = BLOCKVECTOR_NBLOCKS (bl);
644 while (top - bot > 1)
646 half = (top - bot + 1) >> 1;
647 b = BLOCKVECTOR_BLOCK (bl, bot + half);
648 if (BLOCK_START (b) <= pc)
654 /* Now search backward for a block that ends after PC. */
658 b = BLOCKVECTOR_BLOCK (bl, bot);
659 if (BLOCK_END (b) >= pc)
670 /* Return the blockvector immediately containing the innermost lexical block
671 containing the specified pc value, or 0 if there is none.
672 Backward compatibility, no section. */
675 blockvector_for_pc (pc, pindex)
676 register CORE_ADDR pc;
679 return blockvector_for_pc_sect (pc, find_pc_mapped_section (pc),
683 /* Return the innermost lexical block containing the specified pc value
684 in the specified section, or 0 if there is none. */
687 block_for_pc_sect (pc, section)
688 register CORE_ADDR pc;
691 register struct blockvector *bl;
694 bl = blockvector_for_pc_sect (pc, section, &index, NULL);
696 return BLOCKVECTOR_BLOCK (bl, index);
700 /* Return the innermost lexical block containing the specified pc value,
701 or 0 if there is none. Backward compatibility, no section. */
705 register CORE_ADDR pc;
707 return block_for_pc_sect (pc, find_pc_mapped_section (pc));
710 /* Return the function containing pc value PC in section SECTION.
711 Returns 0 if function is not known. */
714 find_pc_sect_function (pc, section)
718 register struct block *b = block_for_pc_sect (pc, section);
721 return block_function (b);
724 /* Return the function containing pc value PC.
725 Returns 0 if function is not known. Backward compatibility, no section */
728 find_pc_function (pc)
731 return find_pc_sect_function (pc, find_pc_mapped_section (pc));
734 /* These variables are used to cache the most recent result
735 * of find_pc_partial_function. */
737 static CORE_ADDR cache_pc_function_low = 0;
738 static CORE_ADDR cache_pc_function_high = 0;
739 static char *cache_pc_function_name = 0;
740 static struct sec *cache_pc_function_section = NULL;
742 /* Clear cache, e.g. when symbol table is discarded. */
745 clear_pc_function_cache ()
747 cache_pc_function_low = 0;
748 cache_pc_function_high = 0;
749 cache_pc_function_name = (char *) 0;
750 cache_pc_function_section = NULL;
753 /* Finds the "function" (text symbol) that is smaller than PC but
754 greatest of all of the potential text symbols in SECTION. Sets
755 *NAME and/or *ADDRESS conditionally if that pointer is non-null.
756 If ENDADDR is non-null, then set *ENDADDR to be the end of the
757 function (exclusive), but passing ENDADDR as non-null means that
758 the function might cause symbols to be read. This function either
759 succeeds or fails (not halfway succeeds). If it succeeds, it sets
760 *NAME, *ADDRESS, and *ENDADDR to real information and returns 1.
761 If it fails, it sets *NAME, *ADDRESS, and *ENDADDR to zero and
765 find_pc_sect_partial_function (pc, section, name, address, endaddr)
772 struct partial_symtab *pst;
774 struct minimal_symbol *msymbol;
775 struct partial_symbol *psb;
776 struct obj_section *osect;
780 mapped_pc = overlay_mapped_address (pc, section);
782 if (mapped_pc >= cache_pc_function_low &&
783 mapped_pc < cache_pc_function_high &&
784 section == cache_pc_function_section)
785 goto return_cached_value;
787 /* If sigtramp is in the u area, it counts as a function (especially
788 important for step_1). */
789 #if defined SIGTRAMP_START
790 if (IN_SIGTRAMP (mapped_pc, (char *) NULL))
792 cache_pc_function_low = SIGTRAMP_START (mapped_pc);
793 cache_pc_function_high = SIGTRAMP_END (mapped_pc);
794 cache_pc_function_name = "<sigtramp>";
795 cache_pc_function_section = section;
796 goto return_cached_value;
800 msymbol = lookup_minimal_symbol_by_pc_section (mapped_pc, section);
801 pst = find_pc_sect_psymtab (mapped_pc, section);
804 /* Need to read the symbols to get a good value for the end address. */
805 if (endaddr != NULL && !pst->readin)
807 /* Need to get the terminal in case symbol-reading produces
809 target_terminal_ours_for_output ();
810 PSYMTAB_TO_SYMTAB (pst);
815 /* Checking whether the msymbol has a larger value is for the
816 "pathological" case mentioned in print_frame_info. */
817 f = find_pc_sect_function (mapped_pc, section);
820 || (BLOCK_START (SYMBOL_BLOCK_VALUE (f))
821 >= SYMBOL_VALUE_ADDRESS (msymbol))))
823 cache_pc_function_low = BLOCK_START (SYMBOL_BLOCK_VALUE (f));
824 cache_pc_function_high = BLOCK_END (SYMBOL_BLOCK_VALUE (f));
825 cache_pc_function_name = SYMBOL_NAME (f);
826 cache_pc_function_section = section;
827 goto return_cached_value;
832 /* Now that static symbols go in the minimal symbol table, perhaps
833 we could just ignore the partial symbols. But at least for now
834 we use the partial or minimal symbol, whichever is larger. */
835 psb = find_pc_sect_psymbol (pst, mapped_pc, section);
838 && (msymbol == NULL ||
839 (SYMBOL_VALUE_ADDRESS (psb)
840 >= SYMBOL_VALUE_ADDRESS (msymbol))))
842 /* This case isn't being cached currently. */
844 *address = SYMBOL_VALUE_ADDRESS (psb);
846 *name = SYMBOL_NAME (psb);
847 /* endaddr non-NULL can't happen here. */
853 /* Not in the normal symbol tables, see if the pc is in a known section.
854 If it's not, then give up. This ensures that anything beyond the end
855 of the text seg doesn't appear to be part of the last function in the
858 osect = find_pc_sect_section (mapped_pc, section);
863 /* Must be in the minimal symbol table. */
866 /* No available symbol. */
876 cache_pc_function_low = SYMBOL_VALUE_ADDRESS (msymbol);
877 cache_pc_function_name = SYMBOL_NAME (msymbol);
878 cache_pc_function_section = section;
880 /* Use the lesser of the next minimal symbol in the same section, or
881 the end of the section, as the end of the function. */
883 /* Step over other symbols at this same address, and symbols in
884 other sections, to find the next symbol in this section with
885 a different address. */
887 for (i = 1; SYMBOL_NAME (msymbol + i) != NULL; i++)
889 if (SYMBOL_VALUE_ADDRESS (msymbol + i) != SYMBOL_VALUE_ADDRESS (msymbol)
890 && SYMBOL_BFD_SECTION (msymbol + i) == SYMBOL_BFD_SECTION (msymbol))
894 if (SYMBOL_NAME (msymbol + i) != NULL
895 && SYMBOL_VALUE_ADDRESS (msymbol + i) < osect->endaddr)
896 cache_pc_function_high = SYMBOL_VALUE_ADDRESS (msymbol + i);
898 /* We got the start address from the last msymbol in the objfile.
899 So the end address is the end of the section. */
900 cache_pc_function_high = osect->endaddr;
906 if (pc_in_unmapped_range (pc, section))
907 *address = overlay_unmapped_address (cache_pc_function_low, section);
909 *address = cache_pc_function_low;
913 *name = cache_pc_function_name;
917 if (pc_in_unmapped_range (pc, section))
919 /* Because the high address is actually beyond the end of
920 the function (and therefore possibly beyond the end of
921 the overlay), we must actually convert (high - 1)
922 and then add one to that. */
924 *endaddr = 1 + overlay_unmapped_address (cache_pc_function_high - 1,
928 *endaddr = cache_pc_function_high;
934 /* Backward compatibility, no section argument */
937 find_pc_partial_function (pc, name, address, endaddr)
945 section = find_pc_overlay (pc);
946 return find_pc_sect_partial_function (pc, section, name, address, endaddr);
949 /* Return the innermost stack frame executing inside of BLOCK,
950 or NULL if there is no such frame. If BLOCK is NULL, just return NULL. */
953 block_innermost_frame (block)
956 struct frame_info *frame;
957 register CORE_ADDR start;
958 register CORE_ADDR end;
963 start = BLOCK_START (block);
964 end = BLOCK_END (block);
969 frame = get_prev_frame (frame);
972 if (frame->pc >= start && frame->pc < end)
977 /* Return the full FRAME which corresponds to the given CORE_ADDR
978 or NULL if no FRAME on the chain corresponds to CORE_ADDR. */
981 find_frame_addr_in_frame_chain (frame_addr)
982 CORE_ADDR frame_addr;
984 struct frame_info *frame = NULL;
986 if (frame_addr == (CORE_ADDR) 0)
991 frame = get_prev_frame (frame);
994 if (FRAME_FP (frame) == frame_addr)
999 #ifdef SIGCONTEXT_PC_OFFSET
1000 /* Get saved user PC for sigtramp from sigcontext for BSD style sigtramp. */
1003 sigtramp_saved_pc (frame)
1004 struct frame_info *frame;
1006 CORE_ADDR sigcontext_addr;
1007 char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
1008 int ptrbytes = TARGET_PTR_BIT / TARGET_CHAR_BIT;
1009 int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
1011 /* Get sigcontext address, it is the third parameter on the stack. */
1013 sigcontext_addr = read_memory_integer (FRAME_ARGS_ADDRESS (frame->next)
1018 sigcontext_addr = read_memory_integer (read_register (SP_REGNUM)
1022 /* Don't cause a memory_error when accessing sigcontext in case the stack
1023 layout has changed or the stack is corrupt. */
1024 target_read_memory (sigcontext_addr + SIGCONTEXT_PC_OFFSET, buf, ptrbytes);
1025 return extract_unsigned_integer (buf, ptrbytes);
1027 #endif /* SIGCONTEXT_PC_OFFSET */
1030 /* Are we in a call dummy? The code below which allows DECR_PC_AFTER_BREAK
1031 below is for infrun.c, which may give the macro a pc without that
1034 extern CORE_ADDR text_end;
1037 pc_in_call_dummy_before_text_end (pc, sp, frame_address)
1040 CORE_ADDR frame_address;
1042 return ((pc) >= text_end - CALL_DUMMY_LENGTH
1043 && (pc) <= text_end + DECR_PC_AFTER_BREAK);
1047 pc_in_call_dummy_after_text_end (pc, sp, frame_address)
1050 CORE_ADDR frame_address;
1052 return ((pc) >= text_end
1053 && (pc) <= text_end + CALL_DUMMY_LENGTH + DECR_PC_AFTER_BREAK);
1056 /* Is the PC in a call dummy? SP and FRAME_ADDRESS are the bottom and
1057 top of the stack frame which we are checking, where "bottom" and
1058 "top" refer to some section of memory which contains the code for
1059 the call dummy. Calls to this macro assume that the contents of
1060 SP_REGNUM and FP_REGNUM (or the saved values thereof), respectively,
1061 are the things to pass.
1063 This won't work on the 29k, where SP_REGNUM and FP_REGNUM don't
1064 have that meaning, but the 29k doesn't use ON_STACK. This could be
1065 fixed by generalizing this scheme, perhaps by passing in a frame
1066 and adding a few fields, at least on machines which need them for
1069 Something simpler, like checking for the stack segment, doesn't work,
1070 since various programs (threads implementations, gcc nested function
1071 stubs, etc) may either allocate stack frames in another segment, or
1072 allocate other kinds of code on the stack. */
1075 pc_in_call_dummy_on_stack (pc, sp, frame_address)
1078 CORE_ADDR frame_address;
1080 return (INNER_THAN ((sp), (pc))
1081 && (frame_address != 0)
1082 && INNER_THAN ((pc), (frame_address)));
1086 pc_in_call_dummy_at_entry_point (pc, sp, frame_address)
1089 CORE_ADDR frame_address;
1091 return ((pc) >= CALL_DUMMY_ADDRESS ()
1092 && (pc) <= (CALL_DUMMY_ADDRESS () + DECR_PC_AFTER_BREAK));
1097 * GENERIC DUMMY FRAMES
1099 * The following code serves to maintain the dummy stack frames for
1100 * inferior function calls (ie. when gdb calls into the inferior via
1101 * call_function_by_hand). This code saves the machine state before
1102 * the call in host memory, so we must maintain an independant stack
1103 * and keep it consistant etc. I am attempting to make this code
1104 * generic enough to be used by many targets.
1106 * The cheapest and most generic way to do CALL_DUMMY on a new target
1107 * is probably to define CALL_DUMMY to be empty, CALL_DUMMY_LENGTH to
1108 * zero, and CALL_DUMMY_LOCATION to AT_ENTRY. Then you must remember
1109 * to define PUSH_RETURN_ADDRESS, because no call instruction will be
1110 * being executed by the target. Also FRAME_CHAIN_VALID as
1111 * generic_frame_chain_valid and FIX_CALL_DUMMY as
1112 * generic_fix_call_dummy. */
1114 /* Dummy frame. This saves the processor state just prior to setting
1115 up the inferior function call. Older targets save the registers
1116 target stack (but that really slows down function calls). */
1120 struct dummy_frame *next;
1129 static struct dummy_frame *dummy_frame_stack = NULL;
1131 /* Function: find_dummy_frame(pc, fp, sp)
1132 Search the stack of dummy frames for one matching the given PC, FP and SP.
1133 This is the work-horse for pc_in_call_dummy and read_register_dummy */
1136 generic_find_dummy_frame (pc, fp)
1140 struct dummy_frame *dummyframe;
1142 if (pc != entry_point_address ())
1145 for (dummyframe = dummy_frame_stack; dummyframe != NULL;
1146 dummyframe = dummyframe->next)
1147 if (fp == dummyframe->fp
1148 || fp == dummyframe->sp
1149 || fp == dummyframe->top)
1150 /* The frame in question lies between the saved fp and sp, inclusive */
1151 return dummyframe->registers;
1156 /* Function: pc_in_call_dummy (pc, fp)
1157 Return true if this is a dummy frame created by gdb for an inferior call */
1160 generic_pc_in_call_dummy (pc, sp, fp)
1165 /* if find_dummy_frame succeeds, then PC is in a call dummy */
1166 /* Note: SP and not FP is passed on. */
1167 return (generic_find_dummy_frame (pc, sp) != 0);
1170 /* Function: read_register_dummy
1171 Find a saved register from before GDB calls a function in the inferior */
1174 generic_read_register_dummy (pc, fp, regno)
1179 char *dummy_regs = generic_find_dummy_frame (pc, fp);
1182 return extract_address (&dummy_regs[REGISTER_BYTE (regno)],
1183 REGISTER_RAW_SIZE (regno));
1188 /* Save all the registers on the dummy frame stack. Most ports save the
1189 registers on the target stack. This results in lots of unnecessary memory
1190 references, which are slow when debugging via a serial line. Instead, we
1191 save all the registers internally, and never write them to the stack. The
1192 registers get restored when the called function returns to the entry point,
1193 where a breakpoint is laying in wait. */
1196 generic_push_dummy_frame ()
1198 struct dummy_frame *dummy_frame;
1199 CORE_ADDR fp = (get_current_frame ())->frame;
1201 /* check to see if there are stale dummy frames,
1202 perhaps left over from when a longjump took us out of a
1203 function that was called by the debugger */
1205 dummy_frame = dummy_frame_stack;
1207 if (INNER_THAN (dummy_frame->fp, fp)) /* stale -- destroy! */
1209 dummy_frame_stack = dummy_frame->next;
1210 free (dummy_frame->registers);
1212 dummy_frame = dummy_frame_stack;
1215 dummy_frame = dummy_frame->next;
1217 dummy_frame = xmalloc (sizeof (struct dummy_frame));
1218 dummy_frame->registers = xmalloc (REGISTER_BYTES);
1220 dummy_frame->pc = read_register (PC_REGNUM);
1221 dummy_frame->sp = read_register (SP_REGNUM);
1222 dummy_frame->top = dummy_frame->sp;
1223 dummy_frame->fp = fp;
1224 read_register_bytes (0, dummy_frame->registers, REGISTER_BYTES);
1225 dummy_frame->next = dummy_frame_stack;
1226 dummy_frame_stack = dummy_frame;
1230 generic_save_dummy_frame_tos (sp)
1233 dummy_frame_stack->top = sp;
1236 /* Function: pop_frame
1237 Restore the machine state from either the saved dummy stack or a
1238 real stack frame. */
1241 generic_pop_current_frame (pop)
1242 void (*pop) PARAMS ((struct frame_info * frame));
1244 struct frame_info *frame = get_current_frame ();
1245 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
1246 generic_pop_dummy_frame ();
1251 /* Function: pop_dummy_frame
1252 Restore the machine state from a saved dummy stack frame. */
1255 generic_pop_dummy_frame ()
1257 struct dummy_frame *dummy_frame = dummy_frame_stack;
1259 /* FIXME: what if the first frame isn't the right one, eg..
1260 because one call-by-hand function has done a longjmp into another one? */
1263 error ("Can't pop dummy frame!");
1264 dummy_frame_stack = dummy_frame->next;
1265 write_register_bytes (0, dummy_frame->registers, REGISTER_BYTES);
1266 flush_cached_frames ();
1268 free (dummy_frame->registers);
1272 /* Function: frame_chain_valid
1273 Returns true for a user frame or a call_function_by_hand dummy frame,
1274 and false for the CRT0 start-up frame. Purpose is to terminate backtrace */
1277 generic_frame_chain_valid (fp, fi)
1279 struct frame_info *fi;
1281 if (PC_IN_CALL_DUMMY (FRAME_SAVED_PC (fi), fp, fp))
1282 return 1; /* don't prune CALL_DUMMY frames */
1283 else /* fall back to default algorithm (see frame.h) */
1285 && (INNER_THAN (fi->frame, fp) || fi->frame == fp)
1286 && !inside_entry_file (FRAME_SAVED_PC (fi)));
1289 /* Function: fix_call_dummy
1290 Stub function. Generic dumy frames typically do not need to fix
1291 the frame being created */
1294 generic_fix_call_dummy (dummy, pc, fun, nargs, args, type, gcc_p)
1299 struct value **args;
1306 /* Function: get_saved_register
1307 Find register number REGNUM relative to FRAME and put its (raw,
1308 target format) contents in *RAW_BUFFER.
1310 Set *OPTIMIZED if the variable was optimized out (and thus can't be
1311 fetched). Note that this is never set to anything other than zero
1312 in this implementation.
1314 Set *LVAL to lval_memory, lval_register, or not_lval, depending on
1315 whether the value was fetched from memory, from a register, or in a
1316 strange and non-modifiable way (e.g. a frame pointer which was
1317 calculated rather than fetched). We will use not_lval for values
1318 fetched from generic dummy frames.
1320 Set *ADDRP to the address, either in memory on as a REGISTER_BYTE
1321 offset into the registers array. If the value is stored in a dummy
1322 frame, set *ADDRP to zero.
1324 To use this implementation, define a function called
1325 "get_saved_register" in your target code, which simply passes all
1326 of its arguments to this function.
1328 The argument RAW_BUFFER must point to aligned memory. */
1331 generic_get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval)
1335 struct frame_info *frame;
1337 enum lval_type *lval;
1339 if (!target_has_registers)
1340 error ("No registers.");
1342 /* Normal systems don't optimize out things with register numbers. */
1343 if (optimized != NULL)
1346 if (addrp) /* default assumption: not found in memory */
1349 /* Note: since the current frame's registers could only have been
1350 saved by frames INTERIOR TO the current frame, we skip examining
1351 the current frame itself: otherwise, we would be getting the
1352 previous frame's registers which were saved by the current frame. */
1354 while (frame && ((frame = frame->next) != NULL))
1356 if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame))
1358 if (lval) /* found it in a CALL_DUMMY frame */
1362 generic_find_dummy_frame (frame->pc, frame->frame) +
1363 REGISTER_BYTE (regnum),
1364 REGISTER_RAW_SIZE (regnum));
1368 FRAME_INIT_SAVED_REGS (frame);
1369 if (frame->saved_regs != NULL
1370 && frame->saved_regs[regnum] != 0)
1372 if (lval) /* found it saved on the stack */
1373 *lval = lval_memory;
1374 if (regnum == SP_REGNUM)
1376 if (raw_buffer) /* SP register treated specially */
1377 store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
1378 frame->saved_regs[regnum]);
1382 if (addrp) /* any other register */
1383 *addrp = frame->saved_regs[regnum];
1385 read_memory (frame->saved_regs[regnum], raw_buffer,
1386 REGISTER_RAW_SIZE (regnum));
1392 /* If we get thru the loop to this point, it means the register was
1393 not saved in any frame. Return the actual live-register value. */
1395 if (lval) /* found it in a live register */
1396 *lval = lval_register;
1398 *addrp = REGISTER_BYTE (regnum);
1400 read_register_gen (regnum, raw_buffer);
1404 _initialize_blockframe ()
1406 obstack_init (&frame_cache_obstack);