* frame.c (frame_unwind_id): Renamed to ...
[binutils-gdb.git] / gdb / frame.h
1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
2
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.
6
7 This file is part of GDB.
8
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.
13
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.
18
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/>. */
21
22 #if !defined (FRAME_H)
23 #define FRAME_H 1
24
25 /* The following is the intended naming schema for frame functions.
26 It isn't 100% consistent, but it is aproaching that. Frame naming
27 schema:
28
29 Prefixes:
30
31 get_frame_WHAT...(): Get WHAT from the THIS frame (functionaly
32 equivalent to THIS->next->unwind->what)
33
34 frame_unwind_WHAT...(): Unwind THIS frame's WHAT from the NEXT
35 frame.
36
37 frame_unwind_caller_WHAT...(): Unwind WHAT for NEXT stack frame's
38 real caller. Any inlined functions in NEXT's stack frame are
39 skipped. Use these to ignore any potentially inlined functions,
40 e.g. inlined into the first instruction of a library trampoline.
41
42 put_frame_WHAT...(): Put a value into this frame (unsafe, need to
43 invalidate the frame / regcache afterwards) (better name more
44 strongly hinting at its unsafeness)
45
46 safe_....(): Safer version of various functions, doesn't throw an
47 error (leave this for later?). Returns non-zero / non-NULL if the
48 request succeeds, zero / NULL otherwize.
49
50 Suffixes:
51
52 void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
53
54 ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
55 alternative is *frame_unsigned_WHAT).
56
57 LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
58
59 What:
60
61 /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
62 *memory.
63
64 /frame/_register* (frame, regnum [, buf]): extract/return register.
65
66 CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
67 stack *address, ...
68
69 */
70
71 struct symtab_and_line;
72 struct frame_unwind;
73 struct frame_base;
74 struct block;
75 struct gdbarch;
76 struct ui_file;
77
78 /* The frame object. */
79
80 struct frame_info;
81
82 /* The frame object's ID. This provides a per-frame unique identifier
83 that can be used to relocate a `struct frame_info' after a target
84 resume or a frame cache destruct. It of course assumes that the
85 inferior hasn't unwound the stack past that frame. */
86
87 struct frame_id
88 {
89 /* The frame's stack address. This shall be constant through out
90 the lifetime of a frame. Note that this requirement applies to
91 not just the function body, but also the prologue and (in theory
92 at least) the epilogue. Since that value needs to fall either on
93 the boundary, or within the frame's address range, the frame's
94 outer-most address (the inner-most address of the previous frame)
95 is used. Watch out for all the legacy targets that still use the
96 function pointer register or stack pointer register. They are
97 wrong.
98
99 This field is valid only if stack_addr_p is true. Otherwise, this
100 frame represents the null frame. */
101 CORE_ADDR stack_addr;
102
103 /* The frame's code address. This shall be constant through out the
104 lifetime of the frame. While the PC (a.k.a. resume address)
105 changes as the function is executed, this code address cannot.
106 Typically, it is set to the address of the entry point of the
107 frame's function (as returned by get_frame_func).
108
109 This field is valid only if code_addr_p is true. Otherwise, this
110 frame is considered to have a wildcard code address, i.e. one that
111 matches every address value in frame comparisons. */
112 CORE_ADDR code_addr;
113
114 /* The frame's special address. This shall be constant through out the
115 lifetime of the frame. This is used for architectures that may have
116 frames that do not change the stack but are still distinct and have
117 some form of distinct identifier (e.g. the ia64 which uses a 2nd
118 stack for registers). This field is treated as unordered - i.e. will
119 not be used in frame ordering comparisons.
120
121 This field is valid only if special_addr_p is true. Otherwise, this
122 frame is considered to have a wildcard special address, i.e. one that
123 matches every address value in frame comparisons. */
124 CORE_ADDR special_addr;
125
126 /* Flags to indicate the above fields have valid contents. */
127 unsigned int stack_addr_p : 1;
128 unsigned int code_addr_p : 1;
129 unsigned int special_addr_p : 1;
130 };
131
132 /* Methods for constructing and comparing Frame IDs. */
133
134 /* For convenience. All fields are zero. */
135 extern const struct frame_id null_frame_id;
136
137 /* Flag to control debugging. */
138
139 extern int frame_debug;
140
141 /* Construct a frame ID. The first parameter is the frame's constant
142 stack address (typically the outer-bound), and the second the
143 frame's constant code address (typically the entry point).
144 The special identifier address is set to indicate a wild card. */
145 extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
146 CORE_ADDR code_addr);
147
148 /* Construct a special frame ID. The first parameter is the frame's constant
149 stack address (typically the outer-bound), the second is the
150 frame's constant code address (typically the entry point),
151 and the third parameter is the frame's special identifier address. */
152 extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
153 CORE_ADDR code_addr,
154 CORE_ADDR special_addr);
155
156 /* Construct a wild card frame ID. The parameter is the frame's constant
157 stack address (typically the outer-bound). The code address as well
158 as the special identifier address are set to indicate wild cards. */
159 extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
160
161 /* Returns non-zero when L is a valid frame (a valid frame has a
162 non-zero .base). */
163 extern int frame_id_p (struct frame_id l);
164
165 /* Returns non-zero when L and R identify the same frame, or, if
166 either L or R have a zero .func, then the same frame base. */
167 extern int frame_id_eq (struct frame_id l, struct frame_id r);
168
169 /* Write the internal representation of a frame ID on the specified
170 stream. */
171 extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
172
173
174 /* Frame types. Some are real, some are signal trampolines, and some
175 are completely artificial (dummy). */
176
177 enum frame_type
178 {
179 /* A true stack frame, created by the target program during normal
180 execution. */
181 NORMAL_FRAME,
182 /* A fake frame, created by GDB when performing an inferior function
183 call. */
184 DUMMY_FRAME,
185 /* In a signal handler, various OSs handle this in various ways.
186 The main thing is that the frame may be far from normal. */
187 SIGTRAMP_FRAME,
188 /* Sentinel or registers frame. This frame obtains register values
189 direct from the inferior's registers. */
190 SENTINEL_FRAME
191 };
192
193 /* For every stopped thread, GDB tracks two frames: current and
194 selected. Current frame is the inner most frame of the selected
195 thread. Selected frame is the one being examined by the the GDB
196 CLI (selected using `up', `down', ...). The frames are created
197 on-demand (via get_prev_frame()) and then held in a frame cache. */
198 /* FIXME: cagney/2002-11-28: Er, there is a lie here. If you do the
199 sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
200 selected frame. At present GDB only tracks the selected frame of
201 the current thread. But be warned, that might change. */
202 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
203 and current frame can be active. Switching threads causes gdb to
204 discard all that cached frame information. Ulgh! Instead, current
205 and selected frame should be bound to a thread. */
206
207 /* On demand, create the inner most frame using information found in
208 the inferior. If the inner most frame can't be created, throw an
209 error. */
210 extern struct frame_info *get_current_frame (void);
211
212 /* Does the current target interface have enough state to be able to
213 query the current inferior for frame info, and is the inferior in a
214 state where that is possible? */
215 extern int has_stack_frames (void);
216
217 /* Invalidates the frame cache (this function should have been called
218 invalidate_cached_frames).
219
220 FIXME: cagney/2002-11-28: There should be two methods: one that
221 reverts the thread's selected frame back to current frame (for when
222 the inferior resumes) and one that does not (for when the user
223 modifies the target invalidating the frame cache). */
224 extern void reinit_frame_cache (void);
225
226 /* On demand, create the selected frame and then return it. If the
227 selected frame can not be created, this function prints then throws
228 an error. When MESSAGE is non-NULL, use it for the error message,
229 otherwize use a generic error message. */
230 /* FIXME: cagney/2002-11-28: At present, when there is no selected
231 frame, this function always returns the current (inner most) frame.
232 It should instead, when a thread has previously had its frame
233 selected (but not resumed) and the frame cache invalidated, find
234 and then return that thread's previously selected frame. */
235 extern struct frame_info *get_selected_frame (const char *message);
236
237 /* Select a specific frame. NULL, apparently implies re-select the
238 inner most frame. */
239 extern void select_frame (struct frame_info *);
240
241 /* Given a FRAME, return the next (more inner, younger) or previous
242 (more outer, older) frame. */
243 extern struct frame_info *get_prev_frame (struct frame_info *);
244 extern struct frame_info *get_next_frame (struct frame_info *);
245
246 /* Given a frame's ID, relocate the frame. Returns NULL if the frame
247 is not found. */
248 extern struct frame_info *frame_find_by_id (struct frame_id id);
249
250 /* Base attributes of a frame: */
251
252 /* The frame's `resume' address. Where the program will resume in
253 this frame.
254
255 This replaced: frame->pc; */
256 extern CORE_ADDR get_frame_pc (struct frame_info *);
257
258 /* An address (not necessarily aligned to an instruction boundary)
259 that falls within THIS frame's code block.
260
261 When a function call is the last statement in a block, the return
262 address for the call may land at the start of the next block.
263 Similarly, if a no-return function call is the last statement in
264 the function, the return address may end up pointing beyond the
265 function, and possibly at the start of the next function.
266
267 These methods make an allowance for this. For call frames, this
268 function returns the frame's PC-1 which "should" be an address in
269 the frame's block. */
270
271 extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
272
273 /* The frame's inner-most bound. AKA the stack-pointer. Confusingly
274 known as top-of-stack. */
275
276 extern CORE_ADDR get_frame_sp (struct frame_info *);
277
278 /* Following on from the `resume' address. Return the entry point
279 address of the function containing that resume address, or zero if
280 that function isn't known. */
281 extern CORE_ADDR get_frame_func (struct frame_info *fi);
282
283 /* Closely related to the resume address, various symbol table
284 attributes that are determined by the PC. Note that for a normal
285 frame, the PC refers to the resume address after the return, and
286 not the call instruction. In such a case, the address is adjusted
287 so that it (approximately) identifies the call site (and not the
288 return site).
289
290 NOTE: cagney/2002-11-28: The frame cache could be used to cache the
291 computed value. Working on the assumption that the bottle-neck is
292 in the single step code, and that code causes the frame cache to be
293 constantly flushed, caching things in a frame is probably of little
294 benefit. As they say `show us the numbers'.
295
296 NOTE: cagney/2002-11-28: Plenty more where this one came from:
297 find_frame_block(), find_frame_partial_function(),
298 find_frame_symtab(), find_frame_function(). Each will need to be
299 carefully considered to determine if the real intent was for it to
300 apply to the PC or the adjusted PC. */
301 extern void find_frame_sal (struct frame_info *frame,
302 struct symtab_and_line *sal);
303
304 /* Set the current source and line to the location given by frame
305 FRAME, if possible. When CENTER is true, adjust so the relevant
306 line is in the center of the next 'list'. */
307
308 void set_current_sal_from_frame (struct frame_info *, int);
309
310 /* Return the frame base (what ever that is) (DEPRECATED).
311
312 Old code was trying to use this single method for two conflicting
313 purposes. Such code needs to be updated to use either of:
314
315 get_frame_id: A low level frame unique identifier, that consists of
316 both a stack and a function address, that can be used to uniquely
317 identify a frame. This value is determined by the frame's
318 low-level unwinder, the stack part [typically] being the
319 top-of-stack of the previous frame, and the function part being the
320 function's start address. Since the correct identification of a
321 frameless function requires both the a stack and function address,
322 the old get_frame_base method was not sufficient.
323
324 get_frame_base_address: get_frame_locals_address:
325 get_frame_args_address: A set of high-level debug-info dependant
326 addresses that fall within the frame. These addresses almost
327 certainly will not match the stack address part of a frame ID (as
328 returned by get_frame_base).
329
330 This replaced: frame->frame; */
331
332 extern CORE_ADDR get_frame_base (struct frame_info *);
333
334 /* Return the per-frame unique identifer. Can be used to relocate a
335 frame after a frame cache flush (and other similar operations). If
336 FI is NULL, return the null_frame_id.
337
338 NOTE: kettenis/20040508: These functions return a structure. On
339 platforms where structures are returned in static storage (vax,
340 m68k), this may trigger compiler bugs in code like:
341
342 if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
343
344 where the return value from the first get_frame_id (l) gets
345 overwritten by the second get_frame_id (r). Please avoid writing
346 code like this. Use code like:
347
348 struct frame_id id = get_frame_id (l);
349 if (frame_id_eq (id, get_frame_id (r)))
350
351 instead, since that avoids the bug. */
352 extern struct frame_id get_frame_id (struct frame_info *fi);
353 extern struct frame_id frame_unwind_caller_id (struct frame_info *next_frame);
354
355 /* Assuming that a frame is `normal', return its base-address, or 0 if
356 the information isn't available. NOTE: This address is really only
357 meaningful to the frame's high-level debug info. */
358 extern CORE_ADDR get_frame_base_address (struct frame_info *);
359
360 /* Assuming that a frame is `normal', return the base-address of the
361 local variables, or 0 if the information isn't available. NOTE:
362 This address is really only meaningful to the frame's high-level
363 debug info. Typically, the argument and locals share a single
364 base-address. */
365 extern CORE_ADDR get_frame_locals_address (struct frame_info *);
366
367 /* Assuming that a frame is `normal', return the base-address of the
368 parameter list, or 0 if that information isn't available. NOTE:
369 This address is really only meaningful to the frame's high-level
370 debug info. Typically, the argument and locals share a single
371 base-address. */
372 extern CORE_ADDR get_frame_args_address (struct frame_info *);
373
374 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
375 for an invalid frame). */
376 extern int frame_relative_level (struct frame_info *fi);
377
378 /* Return the frame's type. */
379
380 extern enum frame_type get_frame_type (struct frame_info *);
381
382 /* For frames where we can not unwind further, describe why. */
383
384 enum unwind_stop_reason
385 {
386 /* No particular reason; either we haven't tried unwinding yet,
387 or we didn't fail. */
388 UNWIND_NO_REASON,
389
390 /* The previous frame's analyzer returns an invalid result
391 from this_id.
392
393 FIXME drow/2006-08-16: This is how GDB used to indicate end of
394 stack. We should migrate to a model where frames always have a
395 valid ID, and this becomes not just an error but an internal
396 error. But that's a project for another day. */
397 UNWIND_NULL_ID,
398
399 /* All the conditions after this point are considered errors;
400 abnormal stack termination. If a backtrace stops for one
401 of these reasons, we'll let the user know. This marker
402 is not a valid stop reason. */
403 UNWIND_FIRST_ERROR,
404
405 /* This frame ID looks like it ought to belong to a NEXT frame,
406 but we got it for a PREV frame. Normally, this is a sign of
407 unwinder failure. It could also indicate stack corruption. */
408 UNWIND_INNER_ID,
409
410 /* This frame has the same ID as the previous one. That means
411 that unwinding further would almost certainly give us another
412 frame with exactly the same ID, so break the chain. Normally,
413 this is a sign of unwinder failure. It could also indicate
414 stack corruption. */
415 UNWIND_SAME_ID,
416
417 /* The frame unwinder didn't find any saved PC, but we needed
418 one to unwind further. */
419 UNWIND_NO_SAVED_PC,
420 };
421
422 /* Return the reason why we can't unwind past this frame. */
423
424 enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
425
426 /* Translate a reason code to an informative string. */
427
428 const char *frame_stop_reason_string (enum unwind_stop_reason);
429
430 /* Unwind the stack frame so that the value of REGNUM, in the previous
431 (up, older) frame is returned. If VALUEP is NULL, don't
432 fetch/compute the value. Instead just return the location of the
433 value. */
434 extern void frame_register_unwind (struct frame_info *frame, int regnum,
435 int *optimizedp, enum lval_type *lvalp,
436 CORE_ADDR *addrp, int *realnump,
437 gdb_byte *valuep);
438
439 /* Fetch a register from this, or unwind a register from the next
440 frame. Note that the get_frame methods are wrappers to
441 frame->next->unwind. They all [potentially] throw an error if the
442 fetch fails. The value methods never return NULL, but usually
443 do return a lazy value. */
444
445 extern void frame_unwind_register (struct frame_info *frame,
446 int regnum, gdb_byte *buf);
447 extern void get_frame_register (struct frame_info *frame,
448 int regnum, gdb_byte *buf);
449
450 struct value *frame_unwind_register_value (struct frame_info *frame,
451 int regnum);
452 struct value *get_frame_register_value (struct frame_info *frame,
453 int regnum);
454
455 extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
456 int regnum);
457 extern LONGEST get_frame_register_signed (struct frame_info *frame,
458 int regnum);
459 extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
460 int regnum);
461 extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
462 int regnum);
463
464
465 /* Get the value of the register that belongs to this FRAME. This
466 function is a wrapper to the call sequence ``frame_register_unwind
467 (get_next_frame (FRAME))''. As per frame_register_unwind(), if
468 VALUEP is NULL, the registers value is not fetched/computed. */
469
470 extern void frame_register (struct frame_info *frame, int regnum,
471 int *optimizedp, enum lval_type *lvalp,
472 CORE_ADDR *addrp, int *realnump,
473 gdb_byte *valuep);
474
475 /* The reverse. Store a register value relative to the specified
476 frame. Note: this call makes the frame's state undefined. The
477 register and frame caches must be flushed. */
478 extern void put_frame_register (struct frame_info *frame, int regnum,
479 const gdb_byte *buf);
480
481 /* Read LEN bytes from one or multiple registers starting with REGNUM
482 in frame FRAME, starting at OFFSET, into BUF. */
483 extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
484 CORE_ADDR offset, int len,
485 gdb_byte *myaddr);
486
487 /* Write LEN bytes to one or multiple registers starting with REGNUM
488 in frame FRAME, starting at OFFSET, into BUF. */
489 extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
490 CORE_ADDR offset, int len,
491 const gdb_byte *myaddr);
492
493 /* Unwind the PC. Strictly speaking return the resume address of the
494 calling frame. For GDB, `pc' is the resume address and not a
495 specific register. */
496
497 extern CORE_ADDR frame_unwind_caller_pc (struct frame_info *frame);
498
499 /* Discard the specified frame. Restoring the registers to the state
500 of the caller. */
501 extern void frame_pop (struct frame_info *frame);
502
503 /* Return memory from the specified frame. A frame knows its thread /
504 LWP and hence can find its way down to a target. The assumption
505 here is that the current and previous frame share a common address
506 space.
507
508 If the memory read fails, these methods throw an error.
509
510 NOTE: cagney/2003-06-03: Should there be unwind versions of these
511 methods? That isn't clear. Can code, for instance, assume that
512 this and the previous frame's memory or architecture are identical?
513 If architecture / memory changes are always separated by special
514 adaptor frames this should be ok. */
515
516 extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
517 gdb_byte *buf, int len);
518 extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
519 CORE_ADDR memaddr, int len);
520 extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
521 CORE_ADDR memaddr, int len);
522
523 /* Same as above, but return non-zero when the entire memory read
524 succeeds, zero otherwize. */
525 extern int safe_frame_unwind_memory (struct frame_info *this_frame,
526 CORE_ADDR addr, gdb_byte *buf, int len);
527
528 /* Return this frame's architecture. */
529
530 extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
531
532
533 /* Values for the source flag to be used in print_frame_info_base(). */
534 enum print_what
535 {
536 /* Print only the source line, like in stepi. */
537 SRC_LINE = -1,
538 /* Print only the location, i.e. level, address (sometimes)
539 function, args, file, line, line num. */
540 LOCATION,
541 /* Print both of the above. */
542 SRC_AND_LOC,
543 /* Print location only, but always include the address. */
544 LOC_AND_ADDRESS
545 };
546
547 /* Allocate zero initialized memory from the frame cache obstack.
548 Appendices to the frame info (such as the unwind cache) should
549 allocate memory using this method. */
550
551 extern void *frame_obstack_zalloc (unsigned long size);
552 #define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
553 #define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
554
555 /* Create a regcache, and copy the frame's registers into it. */
556 struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
557
558 extern struct block *get_frame_block (struct frame_info *,
559 CORE_ADDR *addr_in_block);
560
561 /* Return the `struct block' that belongs to the selected thread's
562 selected frame. If the inferior has no state, return NULL.
563
564 NOTE: cagney/2002-11-29:
565
566 No state? Does the inferior have any execution state (a core file
567 does, an executable does not). At present the code tests
568 `target_has_stack' but I'm left wondering if it should test
569 `target_has_registers' or, even, a merged target_has_state.
570
571 Should it look at the most recently specified SAL? If the target
572 has no state, should this function try to extract a block from the
573 most recently selected SAL? That way `list foo' would give it some
574 sort of reference point. Then again, perhaps that would confuse
575 things.
576
577 Calls to this function can be broken down into two categories: Code
578 that uses the selected block as an additional, but optional, data
579 point; Code that uses the selected block as a prop, when it should
580 have the relevant frame/block/pc explicitly passed in.
581
582 The latter can be eliminated by correctly parameterizing the code,
583 the former though is more interesting. Per the "address" command,
584 it occurs in the CLI code and makes it possible for commands to
585 work, even when the inferior has no state. */
586
587 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
588
589 extern struct symbol *get_frame_function (struct frame_info *);
590
591 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
592
593 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
594
595 extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
596 enum print_what print_what);
597
598 extern void print_stack_frame (struct frame_info *, int print_level,
599 enum print_what print_what);
600
601 extern void print_frame_info (struct frame_info *, int print_level,
602 enum print_what print_what, int args);
603
604 extern struct frame_info *block_innermost_frame (struct block *);
605
606 extern int deprecated_pc_in_call_dummy (struct gdbarch *gdbarch, CORE_ADDR pc);
607
608 /* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
609 function called get_frame_register_p(). This slightly weird (and
610 older) variant of get_frame_register() returns zero (indicating the
611 register is unavailable) if either: the register isn't cached; or
612 the register has been optimized out. Problem is, neither check is
613 exactly correct. A register can't be optimized out (it may not
614 have been saved as part of a function call); The fact that a
615 register isn't in the register cache doesn't mean that the register
616 isn't available (it could have been fetched from memory). */
617
618 extern int frame_register_read (struct frame_info *frame, int regnum,
619 gdb_byte *buf);
620
621 /* From stack.c. */
622 extern void args_info (char *, int);
623
624 extern void locals_info (char *, int);
625
626 extern void (*deprecated_selected_frame_level_changed_hook) (int);
627
628 extern void return_command (char *, int);
629
630 /* Set FRAME's unwinder temporarily, so that we can call a sniffer.
631 Return a cleanup which should be called if unwinding fails, and
632 discarded if it succeeds. */
633
634 struct cleanup *frame_prepare_for_sniffer (struct frame_info *frame,
635 const struct frame_unwind *unwind);
636
637 /* Notes (cagney/2002-11-27, drow/2003-09-06):
638
639 You might think that calls to this function can simply be replaced by a
640 call to get_selected_frame().
641
642 Unfortunately, it isn't that easy.
643
644 The relevant code needs to be audited to determine if it is
645 possible (or practical) to instead pass the applicable frame in as a
646 parameter. For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
647 the deprecated_selected_frame global, while its replacement,
648 PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
649 The only real exceptions occur at the edge (in the CLI code) where
650 user commands need to pick up the selected frame before proceeding.
651
652 There are also some functions called with a NULL frame meaning either "the
653 program is not running" or "use the selected frame".
654
655 This is important. GDB is trying to stamp out the hack:
656
657 saved_frame = deprecated_safe_get_selected_frame ();
658 select_frame (...);
659 hack_using_global_selected_frame ();
660 select_frame (saved_frame);
661
662 Take care!
663
664 This function calls get_selected_frame if the inferior should have a
665 frame, or returns NULL otherwise. */
666
667 extern struct frame_info *deprecated_safe_get_selected_frame (void);
668
669 /* Create a frame using the specified BASE and PC. */
670
671 extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
672
673 #endif /* !defined (FRAME_H) */