1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
3 Copyright (C) 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996, 1997,
4 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2007, 2008, 2009
5 Free Software Foundation, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #if !defined (FRAME_H)
25 /* The following is the intended naming schema for frame functions.
26 It isn't 100% consistent, but it is aproaching that. Frame naming
31 get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
32 equivalent to THIS->next->unwind->what)
34 frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
37 put_frame_WHAT...(): Put a value into this frame (unsafe, need to
38 invalidate the frame / regcache afterwards) (better name more
39 strongly hinting at its unsafeness)
41 safe_....(): Safer version of various functions, doesn't throw an
42 error (leave this for later?). Returns non-zero / non-NULL if the
43 request succeeds, zero / NULL otherwize.
47 void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
49 ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
50 alternative is *frame_unsigned_WHAT).
52 LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
56 /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
59 /frame/_register* (frame, regnum [, buf]): extract/return register.
61 CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
66 struct symtab_and_line;
73 /* The frame object. */
77 /* The frame object's ID. This provides a per-frame unique identifier
78 that can be used to relocate a `struct frame_info' after a target
79 resume or a frame cache destruct. It of course assumes that the
80 inferior hasn't unwound the stack past that frame. */
84 /* The frame's stack address. This shall be constant through out
85 the lifetime of a frame. Note that this requirement applies to
86 not just the function body, but also the prologue and (in theory
87 at least) the epilogue. Since that value needs to fall either on
88 the boundary, or within the frame's address range, the frame's
89 outer-most address (the inner-most address of the previous frame)
90 is used. Watch out for all the legacy targets that still use the
91 function pointer register or stack pointer register. They are
94 This field is valid only if stack_addr_p is true. Otherwise, this
95 frame represents the null frame. */
98 /* The frame's code address. This shall be constant through out the
99 lifetime of the frame. While the PC (a.k.a. resume address)
100 changes as the function is executed, this code address cannot.
101 Typically, it is set to the address of the entry point of the
102 frame's function (as returned by get_frame_func).
104 This field is valid only if code_addr_p is true. Otherwise, this
105 frame is considered to have a wildcard code address, i.e. one that
106 matches every address value in frame comparisons. */
109 /* The frame's special address. This shall be constant through out the
110 lifetime of the frame. This is used for architectures that may have
111 frames that do not change the stack but are still distinct and have
112 some form of distinct identifier (e.g. the ia64 which uses a 2nd
113 stack for registers). This field is treated as unordered - i.e. will
114 not be used in frame ordering comparisons.
116 This field is valid only if special_addr_p is true. Otherwise, this
117 frame is considered to have a wildcard special address, i.e. one that
118 matches every address value in frame comparisons. */
119 CORE_ADDR special_addr;
121 /* Flags to indicate the above fields have valid contents. */
122 unsigned int stack_addr_p : 1;
123 unsigned int code_addr_p : 1;
124 unsigned int special_addr_p : 1;
127 /* Methods for constructing and comparing Frame IDs. */
129 /* For convenience. All fields are zero. */
130 extern const struct frame_id null_frame_id;
132 /* Flag to control debugging. */
134 extern int frame_debug;
136 /* Construct a frame ID. The first parameter is the frame's constant
137 stack address (typically the outer-bound), and the second the
138 frame's constant code address (typically the entry point).
139 The special identifier address is set to indicate a wild card. */
140 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
141 CORE_ADDR code_addr);
143 /* Construct a special frame ID. The first parameter is the frame's constant
144 stack address (typically the outer-bound), the second is the
145 frame's constant code address (typically the entry point),
146 and the third parameter is the frame's special identifier address. */
147 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
149 CORE_ADDR special_addr);
151 /* Construct a wild card frame ID. The parameter is the frame's constant
152 stack address (typically the outer-bound). The code address as well
153 as the special identifier address are set to indicate wild cards. */
154 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
156 /* Returns non-zero when L is a valid frame (a valid frame has a
158 extern int frame_id_p (struct frame_id l);
160 /* Returns non-zero when L and R identify the same frame, or, if
161 either L or R have a zero .func, then the same frame base. */
162 extern int frame_id_eq (struct frame_id l, struct frame_id r);
164 /* Write the internal representation of a frame ID on the specified
166 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
169 /* Frame types. Some are real, some are signal trampolines, and some
170 are completely artificial (dummy). */
174 /* A true stack frame, created by the target program during normal
177 /* A fake frame, created by GDB when performing an inferior function
180 /* In a signal handler, various OSs handle this in various ways.
181 The main thing is that the frame may be far from normal. */
183 /* Sentinel or registers frame. This frame obtains register values
184 direct from the inferior's registers. */
188 /* For every stopped thread, GDB tracks two frames: current and
189 selected. Current frame is the inner most frame of the selected
190 thread. Selected frame is the one being examined by the the GDB
191 CLI (selected using `up', `down', ...). The frames are created
192 on-demand (via get_prev_frame()) and then held in a frame cache. */
193 /* FIXME: cagney/2002-11-28: Er, there is a lie here. If you do the
194 sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
195 selected frame. At present GDB only tracks the selected frame of
196 the current thread. But be warned, that might change. */
197 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
198 and current frame can be active. Switching threads causes gdb to
199 discard all that cached frame information. Ulgh! Instead, current
200 and selected frame should be bound to a thread. */
202 /* On demand, create the inner most frame using information found in
203 the inferior. If the inner most frame can't be created, throw an
205 extern struct frame_info *get_current_frame (void);
207 /* Invalidates the frame cache (this function should have been called
208 invalidate_cached_frames).
210 FIXME: cagney/2002-11-28: There should be two methods: one that
211 reverts the thread's selected frame back to current frame (for when
212 the inferior resumes) and one that does not (for when the user
213 modifies the target invalidating the frame cache). */
214 extern void reinit_frame_cache (void);
216 /* On demand, create the selected frame and then return it. If the
217 selected frame can not be created, this function prints then throws
218 an error. When MESSAGE is non-NULL, use it for the error message,
219 otherwize use a generic error message. */
220 /* FIXME: cagney/2002-11-28: At present, when there is no selected
221 frame, this function always returns the current (inner most) frame.
222 It should instead, when a thread has previously had its frame
223 selected (but not resumed) and the frame cache invalidated, find
224 and then return that thread's previously selected frame. */
225 extern struct frame_info *get_selected_frame (const char *message);
227 /* Select a specific frame. NULL, apparently implies re-select the
229 extern void select_frame (struct frame_info *);
231 /* Given a FRAME, return the next (more inner, younger) or previous
232 (more outer, older) frame. */
233 extern struct frame_info *get_prev_frame (struct frame_info *);
234 extern struct frame_info *get_next_frame (struct frame_info *);
236 /* Given a frame's ID, relocate the frame. Returns NULL if the frame
238 extern struct frame_info *frame_find_by_id (struct frame_id id);
240 /* Base attributes of a frame: */
242 /* The frame's `resume' address. Where the program will resume in
245 This replaced: frame->pc; */
246 extern CORE_ADDR get_frame_pc (struct frame_info *);
248 /* An address (not necessarily aligned to an instruction boundary)
249 that falls within THIS frame's code block.
251 When a function call is the last statement in a block, the return
252 address for the call may land at the start of the next block.
253 Similarly, if a no-return function call is the last statement in
254 the function, the return address may end up pointing beyond the
255 function, and possibly at the start of the next function.
257 These methods make an allowance for this. For call frames, this
258 function returns the frame's PC-1 which "should" be an address in
259 the frame's block. */
261 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
263 /* The frame's inner-most bound. AKA the stack-pointer. Confusingly
264 known as top-of-stack. */
266 extern CORE_ADDR get_frame_sp (struct frame_info *);
268 /* Following on from the `resume' address. Return the entry point
269 address of the function containing that resume address, or zero if
270 that function isn't known. */
271 extern CORE_ADDR get_frame_func (struct frame_info *fi);
273 /* Closely related to the resume address, various symbol table
274 attributes that are determined by the PC. Note that for a normal
275 frame, the PC refers to the resume address after the return, and
276 not the call instruction. In such a case, the address is adjusted
277 so that it (approximately) identifies the call site (and not the
280 NOTE: cagney/2002-11-28: The frame cache could be used to cache the
281 computed value. Working on the assumption that the bottle-neck is
282 in the single step code, and that code causes the frame cache to be
283 constantly flushed, caching things in a frame is probably of little
284 benefit. As they say `show us the numbers'.
286 NOTE: cagney/2002-11-28: Plenty more where this one came from:
287 find_frame_block(), find_frame_partial_function(),
288 find_frame_symtab(), find_frame_function(). Each will need to be
289 carefully considered to determine if the real intent was for it to
290 apply to the PC or the adjusted PC. */
291 extern void find_frame_sal (struct frame_info *frame,
292 struct symtab_and_line *sal);
294 /* Set the current source and line to the location given by frame
295 FRAME, if possible. When CENTER is true, adjust so the relevant
296 line is in the center of the next 'list'. */
298 void set_current_sal_from_frame (struct frame_info *, int);
300 /* Return the frame base (what ever that is) (DEPRECATED).
302 Old code was trying to use this single method for two conflicting
303 purposes. Such code needs to be updated to use either of:
305 get_frame_id: A low level frame unique identifier, that consists of
306 both a stack and a function address, that can be used to uniquely
307 identify a frame. This value is determined by the frame's
308 low-level unwinder, the stack part [typically] being the
309 top-of-stack of the previous frame, and the function part being the
310 function's start address. Since the correct identification of a
311 frameless function requires both the a stack and function address,
312 the old get_frame_base method was not sufficient.
314 get_frame_base_address: get_frame_locals_address:
315 get_frame_args_address: A set of high-level debug-info dependant
316 addresses that fall within the frame. These addresses almost
317 certainly will not match the stack address part of a frame ID (as
318 returned by get_frame_base).
320 This replaced: frame->frame; */
322 extern CORE_ADDR get_frame_base (struct frame_info *);
324 /* Return the per-frame unique identifer. Can be used to relocate a
325 frame after a frame cache flush (and other similar operations). If
326 FI is NULL, return the null_frame_id.
328 NOTE: kettenis/20040508: These functions return a structure. On
329 platforms where structures are returned in static storage (vax,
330 m68k), this may trigger compiler bugs in code like:
332 if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
334 where the return value from the first get_frame_id (l) gets
335 overwritten by the second get_frame_id (r). Please avoid writing
336 code like this. Use code like:
338 struct frame_id id = get_frame_id (l);
339 if (frame_id_eq (id, get_frame_id (r)))
341 instead, since that avoids the bug. */
342 extern struct frame_id get_frame_id (struct frame_info *fi);
343 extern struct frame_id frame_unwind_id (struct frame_info *next_frame);
345 /* Assuming that a frame is `normal', return its base-address, or 0 if
346 the information isn't available. NOTE: This address is really only
347 meaningful to the frame's high-level debug info. */
348 extern CORE_ADDR get_frame_base_address (struct frame_info *);
350 /* Assuming that a frame is `normal', return the base-address of the
351 local variables, or 0 if the information isn't available. NOTE:
352 This address is really only meaningful to the frame's high-level
353 debug info. Typically, the argument and locals share a single
355 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
357 /* Assuming that a frame is `normal', return the base-address of the
358 parameter list, or 0 if that information isn't available. NOTE:
359 This address is really only meaningful to the frame's high-level
360 debug info. Typically, the argument and locals share a single
362 extern CORE_ADDR get_frame_args_address (struct frame_info *);
364 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
365 for an invalid frame). */
366 extern int frame_relative_level (struct frame_info *fi);
368 /* Return the frame's type. */
370 extern enum frame_type get_frame_type (struct frame_info *);
372 /* For frames where we can not unwind further, describe why. */
374 enum unwind_stop_reason
376 /* No particular reason; either we haven't tried unwinding yet,
377 or we didn't fail. */
380 /* The previous frame's analyzer returns an invalid result
383 FIXME drow/2006-08-16: This is how GDB used to indicate end of
384 stack. We should migrate to a model where frames always have a
385 valid ID, and this becomes not just an error but an internal
386 error. But that's a project for another day. */
389 /* All the conditions after this point are considered errors;
390 abnormal stack termination. If a backtrace stops for one
391 of these reasons, we'll let the user know. This marker
392 is not a valid stop reason. */
395 /* This frame ID looks like it ought to belong to a NEXT frame,
396 but we got it for a PREV frame. Normally, this is a sign of
397 unwinder failure. It could also indicate stack corruption. */
400 /* This frame has the same ID as the previous one. That means
401 that unwinding further would almost certainly give us another
402 frame with exactly the same ID, so break the chain. Normally,
403 this is a sign of unwinder failure. It could also indicate
407 /* The frame unwinder didn't find any saved PC, but we needed
408 one to unwind further. */
412 /* Return the reason why we can't unwind past this frame. */
414 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
416 /* Translate a reason code to an informative string. */
418 const char *frame_stop_reason_string (enum unwind_stop_reason);
420 /* Unwind the stack frame so that the value of REGNUM, in the previous
421 (up, older) frame is returned. If VALUEP is NULL, don't
422 fetch/compute the value. Instead just return the location of the
424 extern void frame_register_unwind (struct frame_info *frame, int regnum,
425 int *optimizedp, enum lval_type *lvalp,
426 CORE_ADDR *addrp, int *realnump,
429 /* Fetch a register from this, or unwind a register from the next
430 frame. Note that the get_frame methods are wrappers to
431 frame->next->unwind. They all [potentially] throw an error if the
432 fetch fails. The value methods never return NULL, but usually
433 do return a lazy value. */
435 extern void frame_unwind_register (struct frame_info *frame,
436 int regnum, gdb_byte *buf);
437 extern void get_frame_register (struct frame_info *frame,
438 int regnum, gdb_byte *buf);
440 struct value *frame_unwind_register_value (struct frame_info *frame,
442 struct value *get_frame_register_value (struct frame_info *frame,
445 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
447 extern LONGEST get_frame_register_signed (struct frame_info *frame,
449 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
451 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
455 /* Get the value of the register that belongs to this FRAME. This
456 function is a wrapper to the call sequence ``frame_register_unwind
457 (get_next_frame (FRAME))''. As per frame_register_unwind(), if
458 VALUEP is NULL, the registers value is not fetched/computed. */
460 extern void frame_register (struct frame_info *frame, int regnum,
461 int *optimizedp, enum lval_type *lvalp,
462 CORE_ADDR *addrp, int *realnump,
465 /* The reverse. Store a register value relative to the specified
466 frame. Note: this call makes the frame's state undefined. The
467 register and frame caches must be flushed. */
468 extern void put_frame_register (struct frame_info *frame, int regnum,
469 const gdb_byte *buf);
471 /* Read LEN bytes from one or multiple registers starting with REGNUM
472 in frame FRAME, starting at OFFSET, into BUF. */
473 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
474 CORE_ADDR offset, int len,
477 /* Write LEN bytes to one or multiple registers starting with REGNUM
478 in frame FRAME, starting at OFFSET, into BUF. */
479 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
480 CORE_ADDR offset, int len,
481 const gdb_byte *myaddr);
483 /* Unwind the PC. Strictly speaking return the resume address of the
484 calling frame. For GDB, `pc' is the resume address and not a
485 specific register. */
487 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
489 /* Discard the specified frame. Restoring the registers to the state
491 extern void frame_pop (struct frame_info *frame);
493 /* Return memory from the specified frame. A frame knows its thread /
494 LWP and hence can find its way down to a target. The assumption
495 here is that the current and previous frame share a common address
498 If the memory read fails, these methods throw an error.
500 NOTE: cagney/2003-06-03: Should there be unwind versions of these
501 methods? That isn't clear. Can code, for instance, assume that
502 this and the previous frame's memory or architecture are identical?
503 If architecture / memory changes are always separated by special
504 adaptor frames this should be ok. */
506 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
507 gdb_byte *buf, int len);
508 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
509 CORE_ADDR memaddr, int len);
510 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
511 CORE_ADDR memaddr, int len);
513 /* Same as above, but return non-zero when the entire memory read
514 succeeds, zero otherwize. */
515 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
516 CORE_ADDR addr, gdb_byte *buf, int len);
518 /* Return this frame's architecture. */
520 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
523 /* Values for the source flag to be used in print_frame_info_base(). */
526 /* Print only the source line, like in stepi. */
528 /* Print only the location, i.e. level, address (sometimes)
529 function, args, file, line, line num. */
531 /* Print both of the above. */
533 /* Print location only, but always include the address. */
537 /* Allocate zero initialized memory from the frame cache obstack.
538 Appendices to the frame info (such as the unwind cache) should
539 allocate memory using this method. */
541 extern void *frame_obstack_zalloc (unsigned long size);
542 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
543 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
545 /* Create a regcache, and copy the frame's registers into it. */
546 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
548 extern struct block *get_frame_block (struct frame_info *,
549 CORE_ADDR *addr_in_block);
551 /* Return the `struct block' that belongs to the selected thread's
552 selected frame. If the inferior has no state, return NULL.
554 NOTE: cagney/2002-11-29:
556 No state? Does the inferior have any execution state (a core file
557 does, an executable does not). At present the code tests
558 `target_has_stack' but I'm left wondering if it should test
559 `target_has_registers' or, even, a merged target_has_state.
561 Should it look at the most recently specified SAL? If the target
562 has no state, should this function try to extract a block from the
563 most recently selected SAL? That way `list foo' would give it some
564 sort of reference point. Then again, perhaps that would confuse
567 Calls to this function can be broken down into two categories: Code
568 that uses the selected block as an additional, but optional, data
569 point; Code that uses the selected block as a prop, when it should
570 have the relevant frame/block/pc explicitly passed in.
572 The latter can be eliminated by correctly parameterizing the code,
573 the former though is more interesting. Per the "address" command,
574 it occurs in the CLI code and makes it possible for commands to
575 work, even when the inferior has no state. */
577 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
579 extern struct symbol *get_frame_function (struct frame_info *);
581 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
583 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
585 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
586 enum print_what print_what);
588 extern void print_stack_frame (struct frame_info *, int print_level,
589 enum print_what print_what);
591 extern void print_frame_info (struct frame_info *, int print_level,
592 enum print_what print_what, int args);
594 extern struct frame_info *block_innermost_frame (struct block *);
596 extern int deprecated_pc_in_call_dummy (CORE_ADDR pc);
598 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
599 function called get_frame_register_p(). This slightly weird (and
600 older) variant of get_frame_register() returns zero (indicating the
601 register is unavailable) if either: the register isn't cached; or
602 the register has been optimized out. Problem is, neither check is
603 exactly correct. A register can't be optimized out (it may not
604 have been saved as part of a function call); The fact that a
605 register isn't in the register cache doesn't mean that the register
606 isn't available (it could have been fetched from memory). */
608 extern int frame_register_read (struct frame_info *frame, int regnum,
612 extern void args_info (char *, int);
614 extern void locals_info (char *, int);
616 extern void (*deprecated_selected_frame_level_changed_hook) (int);
618 extern void return_command (char *, int);
620 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
621 Return a cleanup which should be called if unwinding fails, and
622 discarded if it succeeds. */
624 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
625 const struct frame_unwind *unwind);
627 /* Notes (cagney/2002-11-27, drow/2003-09-06):
629 You might think that calls to this function can simply be replaced by a
630 call to get_selected_frame().
632 Unfortunately, it isn't that easy.
634 The relevant code needs to be audited to determine if it is
635 possible (or practical) to instead pass the applicable frame in as a
636 parameter. For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
637 the deprecated_selected_frame global, while its replacement,
638 PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
639 The only real exceptions occur at the edge (in the CLI code) where
640 user commands need to pick up the selected frame before proceeding.
642 There are also some functions called with a NULL frame meaning either "the
643 program is not running" or "use the selected frame".
645 This is important. GDB is trying to stamp out the hack:
647 saved_frame = deprecated_safe_get_selected_frame ();
649 hack_using_global_selected_frame ();
650 select_frame (saved_frame);
654 This function calls get_selected_frame if the inferior should have a
655 frame, or returns NULL otherwise. */
657 extern struct frame_info *deprecated_safe_get_selected_frame (void);
659 /* Create a frame using the specified BASE and PC. */
661 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
663 /* FIXME: cagney/2002-12-06: Has the PC in the current frame changed?
664 "infrun.c", Thanks to gdbarch_decr_pc_after_break, can change the PC after
665 the initial frame create. This puts things back in sync.
667 This replaced: frame->pc = ....; */
668 extern void deprecated_update_frame_pc_hack (struct frame_info *frame,
671 /* FIXME: cagney/2002-12-18: Has the frame's base changed? Or to be
672 more exact, was that initial guess at the frame's base as returned
673 by the deleted read_fp() wrong? If it was, fix it. This shouldn't
674 be necessary since the code should be getting the frame's base
675 correct from the outset.
677 This replaced: frame->frame = ....; */
678 extern void deprecated_update_frame_base_hack (struct frame_info *frame,
681 #endif /* !defined (FRAME_H) */