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
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   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)
40
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.
44
45   Suffixes:
46
47   void /frame/_WHAT(): Read WHAT's value into the buffer parameter.
48
49   ULONGEST /frame/_WHAT_unsigned(): Return an unsigned value (the
50   alternative is *frame_unsigned_WHAT).
51
52   LONGEST /frame/_WHAT_signed(): Return WHAT signed value.
53
54   What:
55
56   /frame/_memory* (frame, coreaddr, len [, buf]): Extract/return
57   *memory.
58
59   /frame/_register* (frame, regnum [, buf]): extract/return register.
60
61   CORE_ADDR /frame/_{pc,sp,...} (frame): Resume address, innner most
62   stack *address, ...
63
64   */
65
66struct symtab_and_line;
67struct frame_unwind;
68struct frame_base;
69struct block;
70struct gdbarch;
71struct ui_file;
72
73/* The frame object.  */
74
75struct frame_info;
76
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.  */
81
82struct frame_id
83{
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
92     wrong.
93
94     This field is valid only if stack_addr_p is true.  Otherwise, this
95     frame represents the null frame.  */
96  CORE_ADDR stack_addr;
97
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 frame_func_unwind().
103
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.  */
107  CORE_ADDR code_addr;
108
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 such as frame_id_inner().
115
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;
120
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;
125};
126
127/* Methods for constructing and comparing Frame IDs.
128
129   NOTE: Given stackless functions A and B, where A calls B (and hence
130   B is inner-to A).  The relationships: !eq(A,B); !eq(B,A);
131   !inner(A,B); !inner(B,A); all hold.
132
133   This is because, while B is inner-to A, B is not strictly inner-to A.
134   Being stackless, they have an identical .stack_addr value, and differ
135   only by their unordered .code_addr and/or .special_addr values.
136
137   Because frame_id_inner is only used as a safety net (e.g.,
138   detect a corrupt stack) the lack of strictness is not a problem.
139   Code needing to determine an exact relationship between two frames
140   must instead use frame_id_eq and frame_id_unwind.  For instance,
141   in the above, to determine that A stepped-into B, the equation
142   "A.id != B.id && A.id == id_unwind (B)" can be used.  */
143
144/* For convenience.  All fields are zero.  */
145extern const struct frame_id null_frame_id;
146
147/* Construct a frame ID.  The first parameter is the frame's constant
148   stack address (typically the outer-bound), and the second the
149   frame's constant code address (typically the entry point).
150   The special identifier address is set to indicate a wild card.  */
151extern struct frame_id frame_id_build (CORE_ADDR stack_addr,
152				       CORE_ADDR code_addr);
153
154/* Construct a special frame ID.  The first parameter is the frame's constant
155   stack address (typically the outer-bound), the second is the
156   frame's constant code address (typically the entry point),
157   and the third parameter is the frame's special identifier address. */
158extern struct frame_id frame_id_build_special (CORE_ADDR stack_addr,
159					       CORE_ADDR code_addr,
160					       CORE_ADDR special_addr);
161
162/* Construct a wild card frame ID.  The parameter is the frame's constant
163   stack address (typically the outer-bound).  The code address as well
164   as the special identifier address are set to indicate wild cards.  */
165extern struct frame_id frame_id_build_wild (CORE_ADDR stack_addr);
166
167/* Returns non-zero when L is a valid frame (a valid frame has a
168   non-zero .base).  */
169extern int frame_id_p (struct frame_id l);
170
171/* Returns non-zero when L and R identify the same frame, or, if
172   either L or R have a zero .func, then the same frame base.  */
173extern int frame_id_eq (struct frame_id l, struct frame_id r);
174
175/* Returns non-zero when L is strictly inner-than R (they have
176   different frame .bases).  Neither L, nor R can be `null'.  See note
177   above about frameless functions.  */
178extern int frame_id_inner (struct frame_id l, struct frame_id r);
179
180/* Write the internal representation of a frame ID on the specified
181   stream.  */
182extern void fprint_frame_id (struct ui_file *file, struct frame_id id);
183
184
185/* Frame types.  Some are real, some are signal trampolines, and some
186   are completely artificial (dummy).  */
187
188enum frame_type
189{
190  /* A true stack frame, created by the target program during normal
191     execution.  */
192  NORMAL_FRAME,
193  /* A fake frame, created by GDB when performing an inferior function
194     call.  */
195  DUMMY_FRAME,
196  /* In a signal handler, various OSs handle this in various ways.
197     The main thing is that the frame may be far from normal.  */
198  SIGTRAMP_FRAME,
199  /* Sentinel or registers frame.  This frame obtains register values
200     direct from the inferior's registers.  */
201  SENTINEL_FRAME
202};
203
204/* For every stopped thread, GDB tracks two frames: current and
205   selected.  Current frame is the inner most frame of the selected
206   thread.  Selected frame is the one being examined by the the GDB
207   CLI (selected using `up', `down', ...).  The frames are created
208   on-demand (via get_prev_frame()) and then held in a frame cache.  */
209/* FIXME: cagney/2002-11-28: Er, there is a lie here.  If you do the
210   sequence: `thread 1; up; thread 2; thread 1' you lose thread 1's
211   selected frame.  At present GDB only tracks the selected frame of
212   the current thread.  But be warned, that might change.  */
213/* FIXME: cagney/2002-11-14: At any time, only one thread's selected
214   and current frame can be active.  Switching threads causes gdb to
215   discard all that cached frame information.  Ulgh!  Instead, current
216   and selected frame should be bound to a thread.  */
217
218/* On demand, create the inner most frame using information found in
219   the inferior.  If the inner most frame can't be created, throw an
220   error.  */
221extern struct frame_info *get_current_frame (void);
222
223/* Invalidates the frame cache (this function should have been called
224   invalidate_cached_frames).
225
226   FIXME: cagney/2002-11-28: There should be two methods: one that
227   reverts the thread's selected frame back to current frame (for when
228   the inferior resumes) and one that does not (for when the user
229   modifies the target invalidating the frame cache).  */
230extern void reinit_frame_cache (void);
231
232/* On demand, create the selected frame and then return it.  If the
233   selected frame can not be created, this function prints then throws
234   an error.  When MESSAGE is non-NULL, use it for the error message,
235   otherwize use a generic error message.  */
236/* FIXME: cagney/2002-11-28: At present, when there is no selected
237   frame, this function always returns the current (inner most) frame.
238   It should instead, when a thread has previously had its frame
239   selected (but not resumed) and the frame cache invalidated, find
240   and then return that thread's previously selected frame.  */
241extern struct frame_info *get_selected_frame (const char *message);
242
243/* Select a specific frame.  NULL, apparently implies re-select the
244   inner most frame.  */
245extern void select_frame (struct frame_info *);
246
247/* Given a FRAME, return the next (more inner, younger) or previous
248   (more outer, older) frame.  */
249extern struct frame_info *get_prev_frame (struct frame_info *);
250extern struct frame_info *get_next_frame (struct frame_info *);
251
252/* Given a frame's ID, relocate the frame.  Returns NULL if the frame
253   is not found.  */
254extern struct frame_info *frame_find_by_id (struct frame_id id);
255
256/* Base attributes of a frame: */
257
258/* The frame's `resume' address.  Where the program will resume in
259   this frame.
260
261   This replaced: frame->pc; */
262extern CORE_ADDR get_frame_pc (struct frame_info *);
263
264/* An address (not necessarily aligned to an instruction boundary)
265   that falls within THIS frame's code block.
266
267   When a function call is the last statement in a block, the return
268   address for the call may land at the start of the next block.
269   Similarly, if a no-return function call is the last statement in
270   the function, the return address may end up pointing beyond the
271   function, and possibly at the start of the next function.
272
273   These methods make an allowance for this.  For call frames, this
274   function returns the frame's PC-1 which "should" be an address in
275   the frame's block.  */
276
277extern CORE_ADDR get_frame_address_in_block (struct frame_info *this_frame);
278
279/* Similar to get_frame_address_in_block, find an address in the
280   block which logically called NEXT_FRAME, assuming it is a THIS_TYPE
281   frame.  */
282
283extern CORE_ADDR frame_unwind_address_in_block (struct frame_info *next_frame,
284						enum frame_type this_type);
285
286/* The frame's inner-most bound.  AKA the stack-pointer.  Confusingly
287   known as top-of-stack.  */
288
289extern CORE_ADDR get_frame_sp (struct frame_info *);
290extern CORE_ADDR frame_sp_unwind (struct frame_info *);
291
292
293/* Following on from the `resume' address.  Return the entry point
294   address of the function containing that resume address, or zero if
295   that function isn't known.  */
296extern CORE_ADDR get_frame_func (struct frame_info *fi);
297
298/* Similar to get_frame_func, find the start of the function which
299   logically called NEXT_FRAME, assuming it is a THIS_TYPE frame.  */
300extern CORE_ADDR frame_func_unwind (struct frame_info *next_frame,
301				    enum frame_type this_type);
302
303/* Closely related to the resume address, various symbol table
304   attributes that are determined by the PC.  Note that for a normal
305   frame, the PC refers to the resume address after the return, and
306   not the call instruction.  In such a case, the address is adjusted
307   so that it (approximately) identifies the call site (and not the
308   return site).
309
310   NOTE: cagney/2002-11-28: The frame cache could be used to cache the
311   computed value.  Working on the assumption that the bottle-neck is
312   in the single step code, and that code causes the frame cache to be
313   constantly flushed, caching things in a frame is probably of little
314   benefit.  As they say `show us the numbers'.
315
316   NOTE: cagney/2002-11-28: Plenty more where this one came from:
317   find_frame_block(), find_frame_partial_function(),
318   find_frame_symtab(), find_frame_function().  Each will need to be
319   carefully considered to determine if the real intent was for it to
320   apply to the PC or the adjusted PC.  */
321extern void find_frame_sal (struct frame_info *frame,
322			    struct symtab_and_line *sal);
323
324/* Set the current source and line to the location given by frame
325   FRAME, if possible.  When CENTER is true, adjust so the relevant
326   line is in the center of the next 'list'.  */
327
328void set_current_sal_from_frame (struct frame_info *, int);
329
330/* Return the frame base (what ever that is) (DEPRECATED).
331
332   Old code was trying to use this single method for two conflicting
333   purposes.  Such code needs to be updated to use either of:
334
335   get_frame_id: A low level frame unique identifier, that consists of
336   both a stack and a function address, that can be used to uniquely
337   identify a frame.  This value is determined by the frame's
338   low-level unwinder, the stack part [typically] being the
339   top-of-stack of the previous frame, and the function part being the
340   function's start address.  Since the correct identification of a
341   frameless function requires both the a stack and function address,
342   the old get_frame_base method was not sufficient.
343
344   get_frame_base_address: get_frame_locals_address:
345   get_frame_args_address: A set of high-level debug-info dependant
346   addresses that fall within the frame.  These addresses almost
347   certainly will not match the stack address part of a frame ID (as
348   returned by get_frame_base).
349
350   This replaced: frame->frame; */
351
352extern CORE_ADDR get_frame_base (struct frame_info *);
353
354/* Return the per-frame unique identifer.  Can be used to relocate a
355   frame after a frame cache flush (and other similar operations).  If
356   FI is NULL, return the null_frame_id.
357
358   NOTE: kettenis/20040508: These functions return a structure.  On
359   platforms where structures are returned in static storage (vax,
360   m68k), this may trigger compiler bugs in code like:
361
362   if (frame_id_eq (get_frame_id (l), get_frame_id (r)))
363
364   where the return value from the first get_frame_id (l) gets
365   overwritten by the second get_frame_id (r).  Please avoid writing
366   code like this.  Use code like:
367
368   struct frame_id id = get_frame_id (l);
369   if (frame_id_eq (id, get_frame_id (r)))
370
371   instead, since that avoids the bug.  */
372extern struct frame_id get_frame_id (struct frame_info *fi);
373extern struct frame_id frame_unwind_id (struct frame_info *next_frame);
374
375/* Assuming that a frame is `normal', return its base-address, or 0 if
376   the information isn't available.  NOTE: This address is really only
377   meaningful to the frame's high-level debug info.  */
378extern CORE_ADDR get_frame_base_address (struct frame_info *);
379
380/* Assuming that a frame is `normal', return the base-address of the
381   local variables, or 0 if the information isn't available.  NOTE:
382   This address is really only meaningful to the frame's high-level
383   debug info.  Typically, the argument and locals share a single
384   base-address.  */
385extern CORE_ADDR get_frame_locals_address (struct frame_info *);
386
387/* Assuming that a frame is `normal', return the base-address of the
388   parameter list, or 0 if that information isn't available.  NOTE:
389   This address is really only meaningful to the frame's high-level
390   debug info.  Typically, the argument and locals share a single
391   base-address.  */
392extern CORE_ADDR get_frame_args_address (struct frame_info *);
393
394/* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
395   for an invalid frame).  */
396extern int frame_relative_level (struct frame_info *fi);
397
398/* Return the frame's type.  */
399
400extern enum frame_type get_frame_type (struct frame_info *);
401
402/* For frames where we can not unwind further, describe why.  */
403
404enum unwind_stop_reason
405  {
406    /* No particular reason; either we haven't tried unwinding yet,
407       or we didn't fail.  */
408    UNWIND_NO_REASON,
409
410    /* The previous frame's analyzer returns an invalid result
411       from this_id.
412
413       FIXME drow/2006-08-16: This is how GDB used to indicate end of
414       stack.  We should migrate to a model where frames always have a
415       valid ID, and this becomes not just an error but an internal
416       error.  But that's a project for another day.  */
417    UNWIND_NULL_ID,
418
419    /* All the conditions after this point are considered errors;
420       abnormal stack termination.  If a backtrace stops for one
421       of these reasons, we'll let the user know.  This marker
422       is not a valid stop reason.  */
423    UNWIND_FIRST_ERROR,
424
425    /* This frame ID looks like it ought to belong to a NEXT frame,
426       but we got it for a PREV frame.  Normally, this is a sign of
427       unwinder failure.  It could also indicate stack corruption.  */
428    UNWIND_INNER_ID,
429
430    /* This frame has the same ID as the previous one.  That means
431       that unwinding further would almost certainly give us another
432       frame with exactly the same ID, so break the chain.  Normally,
433       this is a sign of unwinder failure.  It could also indicate
434       stack corruption.  */
435    UNWIND_SAME_ID,
436
437    /* The frame unwinder didn't find any saved PC, but we needed
438       one to unwind further.  */
439    UNWIND_NO_SAVED_PC,
440  };
441
442/* Return the reason why we can't unwind past this frame.  */
443
444enum unwind_stop_reason get_frame_unwind_stop_reason (struct frame_info *);
445
446/* Translate a reason code to an informative string.  */
447
448const char *frame_stop_reason_string (enum unwind_stop_reason);
449
450/* Unwind the stack frame so that the value of REGNUM, in the previous
451   (up, older) frame is returned.  If VALUEP is NULL, don't
452   fetch/compute the value.  Instead just return the location of the
453   value.  */
454extern void frame_register_unwind (struct frame_info *frame, int regnum,
455				   int *optimizedp, enum lval_type *lvalp,
456				   CORE_ADDR *addrp, int *realnump,
457				   gdb_byte *valuep);
458
459/* Fetch a register from this, or unwind a register from the next
460   frame.  Note that the get_frame methods are wrappers to
461   frame->next->unwind.  They all [potentially] throw an error if the
462   fetch fails.  */
463
464extern void frame_unwind_register (struct frame_info *frame,
465				   int regnum, gdb_byte *buf);
466extern void get_frame_register (struct frame_info *frame,
467				int regnum, gdb_byte *buf);
468
469extern LONGEST frame_unwind_register_signed (struct frame_info *frame,
470					     int regnum);
471extern LONGEST get_frame_register_signed (struct frame_info *frame,
472					  int regnum);
473extern ULONGEST frame_unwind_register_unsigned (struct frame_info *frame,
474					       int regnum);
475extern ULONGEST get_frame_register_unsigned (struct frame_info *frame,
476					     int regnum);
477
478
479/* Use frame_unwind_register_signed.  */
480extern void frame_unwind_unsigned_register (struct frame_info *frame,
481					    int regnum, ULONGEST *val);
482
483/* Get the value of the register that belongs to this FRAME.  This
484   function is a wrapper to the call sequence ``frame_register_unwind
485   (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
486   VALUEP is NULL, the registers value is not fetched/computed.  */
487
488extern void frame_register (struct frame_info *frame, int regnum,
489			    int *optimizedp, enum lval_type *lvalp,
490			    CORE_ADDR *addrp, int *realnump,
491			    gdb_byte *valuep);
492
493/* The reverse.  Store a register value relative to the specified
494   frame.  Note: this call makes the frame's state undefined.  The
495   register and frame caches must be flushed.  */
496extern void put_frame_register (struct frame_info *frame, int regnum,
497				const gdb_byte *buf);
498
499/* Read LEN bytes from one or multiple registers starting with REGNUM
500   in frame FRAME, starting at OFFSET, into BUF.  */
501extern int get_frame_register_bytes (struct frame_info *frame, int regnum,
502				     CORE_ADDR offset, int len,
503				     gdb_byte *myaddr);
504
505/* Write LEN bytes to one or multiple registers starting with REGNUM
506   in frame FRAME, starting at OFFSET, into BUF.  */
507extern void put_frame_register_bytes (struct frame_info *frame, int regnum,
508				      CORE_ADDR offset, int len,
509				      const gdb_byte *myaddr);
510
511/* Map between a frame register number and its name.  A frame register
512   space is a superset of the cooked register space --- it also
513   includes builtin registers.  If NAMELEN is negative, use the NAME's
514   length when doing the comparison.  */
515
516extern int frame_map_name_to_regnum (struct frame_info *frame,
517				     const char *name, int namelen);
518extern const char *frame_map_regnum_to_name (struct frame_info *frame,
519					     int regnum);
520
521/* Unwind the PC.  Strictly speaking return the resume address of the
522   calling frame.  For GDB, `pc' is the resume address and not a
523   specific register.  */
524
525extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
526
527/* Discard the specified frame.  Restoring the registers to the state
528   of the caller.  */
529extern void frame_pop (struct frame_info *frame);
530
531/* Return memory from the specified frame.  A frame knows its thread /
532   LWP and hence can find its way down to a target.  The assumption
533   here is that the current and previous frame share a common address
534   space.
535
536   If the memory read fails, these methods throw an error.
537
538   NOTE: cagney/2003-06-03: Should there be unwind versions of these
539   methods?  That isn't clear.  Can code, for instance, assume that
540   this and the previous frame's memory or architecture are identical?
541   If architecture / memory changes are always separated by special
542   adaptor frames this should be ok.  */
543
544extern void get_frame_memory (struct frame_info *this_frame, CORE_ADDR addr,
545			      gdb_byte *buf, int len);
546extern LONGEST get_frame_memory_signed (struct frame_info *this_frame,
547					CORE_ADDR memaddr, int len);
548extern ULONGEST get_frame_memory_unsigned (struct frame_info *this_frame,
549					   CORE_ADDR memaddr, int len);
550
551/* Same as above, but return non-zero when the entire memory read
552   succeeds, zero otherwize.  */
553extern int safe_frame_unwind_memory (struct frame_info *this_frame,
554				     CORE_ADDR addr, gdb_byte *buf, int len);
555
556/* Return this frame's architecture.  */
557
558extern struct gdbarch *get_frame_arch (struct frame_info *this_frame);
559
560
561/* Values for the source flag to be used in print_frame_info_base().  */
562enum print_what
563  {
564    /* Print only the source line, like in stepi. */
565    SRC_LINE = -1,
566    /* Print only the location, i.e. level, address (sometimes)
567       function, args, file, line, line num. */
568    LOCATION,
569    /* Print both of the above. */
570    SRC_AND_LOC,
571    /* Print location only, but always include the address. */
572    LOC_AND_ADDRESS
573  };
574
575/* Allocate additional space for appendices to a struct frame_info.
576   NOTE: Much of GDB's code works on the assumption that the allocated
577   saved_regs[] array is the size specified below.  If you try to make
578   that array smaller, GDB will happily walk off its end.  */
579
580#ifdef SIZEOF_FRAME_SAVED_REGS
581#error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
582#endif
583#define SIZEOF_FRAME_SAVED_REGS \
584        (sizeof (CORE_ADDR) * (gdbarch_num_regs (current_gdbarch)\
585			       + gdbarch_num_pseudo_regs (current_gdbarch)))
586
587/* Allocate zero initialized memory from the frame cache obstack.
588   Appendices to the frame info (such as the unwind cache) should
589   allocate memory using this method.  */
590
591extern void *frame_obstack_zalloc (unsigned long size);
592#define FRAME_OBSTACK_ZALLOC(TYPE) ((TYPE *) frame_obstack_zalloc (sizeof (TYPE)))
593#define FRAME_OBSTACK_CALLOC(NUMBER,TYPE) ((TYPE *) frame_obstack_zalloc ((NUMBER) * sizeof (TYPE)))
594
595/* Create a regcache, and copy the frame's registers into it.  */
596struct regcache *frame_save_as_regcache (struct frame_info *this_frame);
597
598extern struct block *get_frame_block (struct frame_info *,
599                                      CORE_ADDR *addr_in_block);
600
601/* Return the `struct block' that belongs to the selected thread's
602   selected frame.  If the inferior has no state, return NULL.
603
604   NOTE: cagney/2002-11-29:
605
606   No state?  Does the inferior have any execution state (a core file
607   does, an executable does not).  At present the code tests
608   `target_has_stack' but I'm left wondering if it should test
609   `target_has_registers' or, even, a merged target_has_state.
610
611   Should it look at the most recently specified SAL?  If the target
612   has no state, should this function try to extract a block from the
613   most recently selected SAL?  That way `list foo' would give it some
614   sort of reference point.  Then again, perhaps that would confuse
615   things.
616
617   Calls to this function can be broken down into two categories: Code
618   that uses the selected block as an additional, but optional, data
619   point; Code that uses the selected block as a prop, when it should
620   have the relevant frame/block/pc explicitly passed in.
621
622   The latter can be eliminated by correctly parameterizing the code,
623   the former though is more interesting.  Per the "address" command,
624   it occurs in the CLI code and makes it possible for commands to
625   work, even when the inferior has no state.  */
626
627extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
628
629extern struct symbol *get_frame_function (struct frame_info *);
630
631extern CORE_ADDR get_pc_function_start (CORE_ADDR);
632
633extern struct frame_info *find_relative_frame (struct frame_info *, int *);
634
635extern void show_and_print_stack_frame (struct frame_info *fi, int print_level,
636					enum print_what print_what);
637
638extern void print_stack_frame (struct frame_info *, int print_level,
639			       enum print_what print_what);
640
641extern void show_stack_frame (struct frame_info *);
642
643extern void print_frame_info (struct frame_info *, int print_level,
644			      enum print_what print_what, int args);
645
646extern struct frame_info *block_innermost_frame (struct block *);
647
648extern int deprecated_pc_in_call_dummy (CORE_ADDR pc);
649
650/* FIXME: cagney/2003-02-02: Should be deprecated or replaced with a
651   function called get_frame_register_p().  This slightly weird (and
652   older) variant of get_frame_register() returns zero (indicating the
653   register is unavailable) if either: the register isn't cached; or
654   the register has been optimized out.  Problem is, neither check is
655   exactly correct.  A register can't be optimized out (it may not
656   have been saved as part of a function call); The fact that a
657   register isn't in the register cache doesn't mean that the register
658   isn't available (it could have been fetched from memory).  */
659
660extern int frame_register_read (struct frame_info *frame, int regnum,
661				gdb_byte *buf);
662
663/* From stack.c.  */
664extern void args_info (char *, int);
665
666extern void locals_info (char *, int);
667
668extern void (*deprecated_selected_frame_level_changed_hook) (int);
669
670extern void return_command (char *, int);
671
672
673/* Notes (cagney/2002-11-27, drow/2003-09-06):
674
675   You might think that calls to this function can simply be replaced by a
676   call to get_selected_frame().
677
678   Unfortunately, it isn't that easy.
679
680   The relevant code needs to be audited to determine if it is
681   possible (or practical) to instead pass the applicable frame in as a
682   parameter.  For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
683   the deprecated_selected_frame global, while its replacement,
684   PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
685   The only real exceptions occur at the edge (in the CLI code) where
686   user commands need to pick up the selected frame before proceeding.
687
688   There are also some functions called with a NULL frame meaning either "the
689   program is not running" or "use the selected frame".
690
691   This is important.  GDB is trying to stamp out the hack:
692
693   saved_frame = deprecated_safe_get_selected_frame ();
694   select_frame (...);
695   hack_using_global_selected_frame ();
696   select_frame (saved_frame);
697
698   Take care!
699
700   This function calls get_selected_frame if the inferior should have a
701   frame, or returns NULL otherwise.  */
702
703extern struct frame_info *deprecated_safe_get_selected_frame (void);
704
705/* Create a frame using the specified BASE and PC.  */
706
707extern struct frame_info *create_new_frame (CORE_ADDR base, CORE_ADDR pc);
708
709/* FIXME: cagney/2002-12-06: Has the PC in the current frame changed?
710   "infrun.c", Thanks to gdbarch_decr_pc_after_break, can change the PC after
711   the initial frame create.  This puts things back in sync.
712
713   This replaced: frame->pc = ....; */
714extern void deprecated_update_frame_pc_hack (struct frame_info *frame,
715					     CORE_ADDR pc);
716
717/* FIXME: cagney/2002-12-18: Has the frame's base changed?  Or to be
718   more exact, was that initial guess at the frame's base as returned
719   by the deleted read_fp() wrong?  If it was, fix it.  This shouldn't
720   be necessary since the code should be getting the frame's base
721   correct from the outset.
722
723   This replaced: frame->frame = ....; */
724extern void deprecated_update_frame_base_hack (struct frame_info *frame,
725					       CORE_ADDR base);
726
727#endif /* !defined (FRAME_H)  */
728