1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
3 Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996,
4 1997, 1998, 1999, 2000, 2001, 2002 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. */
23 #if !defined (FRAME_H)
26 /* The frame object. */
30 /* The frame object's ID. This provides a per-frame unique identifier
31 that can be used to relocate a `struct frame_info' after a target
32 resume or a frame cache destruct (assuming the target hasn't
33 unwound the stack past that frame - a problem handled elsewhere). */
37 /* The frame's address. This should be constant through out the
38 lifetime of a frame. */
39 /* NOTE: cagney/2002-11-16: The ia64 has two stacks and hence two
40 frame bases. This will need to be expanded to accomodate that. */
42 /* The frame's current PC. While the PC within the function may
43 change, the function that contains the PC does not. Should this
44 instead be the frame's function? */
48 /* For every stopped thread, GDB tracks two frames: current and
49 selected. Current frame is the inner most frame of the selected
50 thread. Selected frame is the one being examined by the the GDB
51 CLI (selected using `up', `down', ...). The frames are created
52 on-demand (via get_prev_frame()) and then held in a frame cache. */
53 /* FIXME: cagney/2002-11-28: Er, there is a lie here. If you do the
54 sequence: `thread 1; up; thread 2; thread 1' you loose thread 1's
55 selected frame. At present GDB only tracks the selected frame of
56 the current thread. But be warned, that might change. */
57 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
58 and current frame can be active. Switching threads causes gdb to
59 discard all that cached frame information. Ulgh! Instead, current
60 and selected frame should be bound to a thread. */
62 /* On demand, create the inner most frame using information found in
63 the inferior. If the inner most frame can't be created, throw an
65 extern struct frame_info *get_current_frame (void);
67 /* Invalidates the frame cache (this function should have been called
68 invalidate_cached_frames).
70 FIXME: cagney/2002-11-28: The only difference between
71 flush_cached_frames() and reinit_frame_cache() is that the latter
72 explicitly sets the selected frame back to the current frame there
73 isn't any real difference (except that one delays the selection of
74 a new frame). There should instead be a get_selected_frame()
75 method that reinit's the frame cache on-demand. As for
76 invalidating the cache, there should be two methods one that
77 reverts the thread's selected frame back to current frame (for when
78 the inferior resumes) and one that does not (for when the user
79 modifies the target invalidating the frame cache). */
80 extern void flush_cached_frames (void);
81 extern void reinit_frame_cache (void);
83 /* Select a specific frame. NULL, apparently implies re-select the
85 extern void select_frame (struct frame_info *);
87 /* Given a FRAME, return the next (more inner, younger) or previous
88 (more outer, older) frame. */
89 extern struct frame_info *get_prev_frame (struct frame_info *);
90 extern struct frame_info *get_next_frame (struct frame_info *);
92 /* Given a frame's ID, relocate the frame. Returns NULL if the frame
94 extern struct frame_info *frame_find_by_id (struct frame_id id);
96 /* Base attributes of a frame: */
98 /* The frame's `resume' address. Where the program will resume in
100 extern CORE_ADDR get_frame_pc (struct frame_info *);
102 /* Return the frame address from FI. Except in the machine-dependent
103 *FRAME* macros, a frame address has no defined meaning other than
104 as a magic cookie which identifies a frame over calls to the
105 inferior (um, SEE NOTE BELOW). The only known exception is
106 inferior.h (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there. You
107 cannot assume that a frame address contains enough information to
108 reconstruct the frame; if you want more than just to identify the
109 frame (e.g. be able to fetch variables relative to that frame),
110 then save the whole struct frame_info (and the next struct
111 frame_info, since the latter is used for fetching variables on some
112 machines) (um, again SEE NOTE BELOW).
114 NOTE: cagney/2002-11-18: Actually, the frame address isn't
115 sufficient for identifying a frame, and the counter examples are
118 Code that needs to (re)identify a frame must use get_frame_id() and
119 frame_find_by_id() (and in the future, a frame_compare() function
120 instead of INNER_THAN()). Two reasons: an architecture (e.g.,
121 ia64) can have more than one frame address (due to multiple stack
122 pointers) (frame ID is going to be expanded to accomodate this);
123 successive frameless function calls can only be differientated by
124 comparing both the frame's base and the frame's enclosing function
125 (frame_find_by_id() is going to be modified to perform this test).
127 The generic dummy frame version of PC_IN_CALL_DUMMY() is able to
128 identify a dummy frame using only the PC value. So the frame
129 address is not needed. In fact, most PC_IN_CALL_DUMMY() calls now
130 pass zero as the frame/sp values as the caller knows that those
131 values won't be used. Once all architectures are using generic
132 dummy frames, PC_IN_CALL_DUMMY() can drop the sp/frame parameters.
133 When it comes to finding a dummy frame, the next frame's frame ID
134 (with out duing an unwind) can be used (ok, could if it wasn't for
135 the need to change the way the PPC defined frame base in a strange
138 Modern architectures should be using something like dwarf2's
139 location expression to describe where a variable lives. Such
140 expressions specify their own debug info centric frame address.
141 Consequently, a generic frame address is pretty meaningless. */
143 extern CORE_ADDR get_frame_base (struct frame_info *);
145 /* Return the per-frame unique identifer. Can be used to relocate a
146 frame after a frame cache flush (and other similar operations). */
147 extern void get_frame_id (struct frame_info *fi, struct frame_id *id);
149 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
150 for an invalid frame). */
151 extern int frame_relative_level (struct frame_info *fi);
153 /* Return the frame's type. Some are real, some are signal
154 trampolines, and some are completly artificial (dummy). */
158 /* A true stack frame, created by the target program during normal
161 /* A fake frame, created by GDB when performing an inferior function
164 /* In a signal handler, various OSs handle this in various ways.
165 The main thing is that the frame may be far from normal. */
168 extern enum frame_type get_frame_type (struct frame_info *);
170 /* FIXME: cagney/2002-11-10: Some targets want to directly mark a
171 frame as being of a specific type. This shouldn't be necessary.
172 PC_IN_SIGTRAMP() indicates a SIGTRAMP_FRAME and PC_IN_CALL_DUMMY()
173 indicates a DUMMY_FRAME. I suspect the real problem here is that
174 get_prev_frame() only sets initialized after INIT_EXTRA_FRAME_INFO
175 as been called. Consequently, some targets found that the frame's
176 type was wrong and tried to fix it. The correct fix is to modify
177 get_prev_frame() so that it initializes the frame's type before
178 calling any other functions. */
179 extern void deprecated_set_frame_type (struct frame_info *,
180 enum frame_type type);
182 /* Unwind the stack frame so that the value of REGNUM, in the previous
183 (up, older) frame is returned. If VALUEP is NULL, don't
184 fetch/compute the value. Instead just return the location of the
186 extern void frame_register_unwind (struct frame_info *frame, int regnum,
187 int *optimizedp, enum lval_type *lvalp,
188 CORE_ADDR *addrp, int *realnump,
191 /* More convenient interface to frame_register_unwind(). */
192 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
193 be changed to return an indication that the read succeeded. */
195 extern void frame_unwind_signed_register (struct frame_info *frame,
196 int regnum, LONGEST *val);
198 extern void frame_unwind_unsigned_register (struct frame_info *frame,
199 int regnum, ULONGEST *val);
201 /* Get the value of the register that belongs to this FRAME. This
202 function is a wrapper to the call sequence ``frame_unwind_register
203 (get_next_frame (FRAME))''. As per frame_register_unwind(), if
204 VALUEP is NULL, the registers value is not fetched/computed. */
206 extern void frame_register (struct frame_info *frame, int regnum,
207 int *optimizedp, enum lval_type *lvalp,
208 CORE_ADDR *addrp, int *realnump,
211 /* More convenient interface to frame_register(). */
212 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
213 be changed to return an indication that the read succeeded. */
215 extern void frame_read_signed_register (struct frame_info *frame,
216 int regnum, LONGEST *val);
218 extern void frame_read_unsigned_register (struct frame_info *frame,
219 int regnum, ULONGEST *val);
221 /* Map between a frame register number and its name. A frame register
222 space is a superset of the cooked register space --- it also
223 includes builtin registers. */
225 extern int frame_map_name_to_regnum (const char *name, int strlen);
226 extern const char *frame_map_regnum_to_name (int regnum);
228 /* Unwind the PC. Strictly speaking return the resume address of the
229 calling frame. For GDB, `pc' is the resume address and not a
230 specific register. */
232 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
235 /* Return the location (and possibly value) of REGNUM for the previous
236 (older, up) frame. All parameters except VALUEP can be assumed to
237 be non NULL. When VALUEP is NULL, just the location of the
238 register should be returned.
240 UNWIND_CACHE is provided as mechanism for implementing a per-frame
241 local cache. It's initial value being NULL. Memory for that cache
242 should be allocated using frame_obstack_alloc().
244 Register window architectures (eg SPARC) should note that REGNUM
245 identifies the register for the previous frame. For instance, a
246 request for the value of "o1" for the previous frame would be found
247 in the register "i1" in this FRAME. */
249 typedef void (frame_register_unwind_ftype) (struct frame_info *frame,
253 enum lval_type *lvalp,
258 /* Same as for registers above, but return the address at which the
259 calling frame would resume. */
261 typedef CORE_ADDR (frame_pc_unwind_ftype) (struct frame_info *frame,
262 void **unwind_cache);
264 /* Describe the saved registers of a frame. */
266 #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS)
267 /* XXXX - deprecated */
268 struct frame_saved_regs
270 /* For each register R (except the SP), regs[R] is the address at
271 which it was saved on entry to the frame, or zero if it was not
272 saved on entry to this frame. This includes special registers
273 such as pc and fp saved in special ways in the stack frame.
275 regs[SP_REGNUM] is different. It holds the actual SP, not the
276 address at which it was saved. */
278 CORE_ADDR regs[NUM_REGS];
282 /* We keep a cache of stack frames, each of which is a "struct
283 frame_info". The innermost one gets allocated (in
284 wait_for_inferior) each time the inferior stops; current_frame
285 points to it. Additional frames get allocated (in
286 get_prev_frame) as needed, and are chained through the next
287 and prev fields. Any time that the frame cache becomes invalid
288 (most notably when we execute something, but also if we change how
289 we interpret the frames (e.g. "set heuristic-fence-post" in
290 mips-tdep.c, or anything which reads new symbols)), we should call
291 reinit_frame_cache. */
295 /* Nominal address of the frame described. See comments at
296 get_frame_base() about what this means outside the *FRAME*
297 macros; in the *FRAME* macros, it can mean whatever makes most
298 sense for this machine. */
301 /* Address at which execution is occurring in this frame.
302 For the innermost frame, it's the current pc.
303 For other frames, it is a pc saved in the next frame. */
306 /* Level of this frame. The inner-most (youngest) frame is at
307 level 0. As you move towards the outer-most (oldest) frame,
308 the level increases. This is a cached value. It could just as
309 easily be computed by counting back from the selected frame to
310 the inner most frame. */
311 /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
312 reserved to indicate a bogus frame - one that has been created
313 just to keep GDB happy (GDB always needs a frame). For the
314 moment leave this as speculation. */
317 /* The frame's type. */
318 enum frame_type type;
320 /* For each register, address of where it was saved on entry to
321 the frame, or zero if it was not saved on entry to this frame.
322 This includes special registers such as pc and fp saved in
323 special ways in the stack frame. The SP_REGNUM is even more
324 special, the address here is the sp for the previous frame, not
325 the address where the sp was saved. */
326 /* Allocated by frame_saved_regs_zalloc () which is called /
327 initialized by FRAME_INIT_SAVED_REGS(). */
328 CORE_ADDR *saved_regs; /*NUM_REGS + NUM_PSEUDO_REGS*/
330 #ifdef EXTRA_FRAME_INFO
331 /* XXXX - deprecated */
332 /* Anything extra for this structure that may have been defined
333 in the machine dependent files. */
337 /* Anything extra for this structure that may have been defined
338 in the machine dependent files. */
339 /* Allocated by frame_obstack_alloc () which is called /
340 initialized by INIT_EXTRA_FRAME_INFO */
341 struct frame_extra_info *extra_info;
343 /* If dwarf2 unwind frame informations is used, this structure holds all
344 related unwind data. */
345 struct context *context;
347 /* Unwind cache shared between the unwind functions - they had
348 better all agree as to the contents. */
351 /* See description above. The previous frame's registers. */
352 frame_register_unwind_ftype *register_unwind;
354 /* See description above. The previous frame's resume address.
355 Save the previous PC in a local cache. */
356 frame_pc_unwind_ftype *pc_unwind;
357 int pc_unwind_cache_p;
358 CORE_ADDR pc_unwind_cache;
360 /* Pointers to the next (down, inner, younger) and previous (up,
361 outer, older) frame_info's in the frame cache. */
362 struct frame_info *next; /* down, inner, younger */
364 struct frame_info *prev; /* up, outer, older */
367 /* Values for the source flag to be used in print_frame_info_base(). */
370 /* Print only the source line, like in stepi. */
372 /* Print only the location, i.e. level, address (sometimes)
373 function, args, file, line, line num. */
375 /* Print both of the above. */
377 /* Print location only, but always include the address. */
381 /* Allocate additional space for appendices to a struct frame_info.
382 NOTE: Much of GDB's code works on the assumption that the allocated
383 saved_regs[] array is the size specified below. If you try to make
384 that array smaller, GDB will happily walk off its end. */
386 #ifdef SIZEOF_FRAME_SAVED_REGS
387 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
389 #define SIZEOF_FRAME_SAVED_REGS \
390 (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
392 extern void *frame_obstack_alloc (unsigned long size);
393 extern void frame_saved_regs_zalloc (struct frame_info *);
395 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
396 targets. If FRAME_CHAIN_VALID returns zero it means that the given frame
397 is the outermost one and has no caller.
399 XXXX - both default and alternate frame_chain_valid functions are
400 deprecated. New code should use dummy frames and one of the
401 generic functions. */
403 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
404 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
405 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
406 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
407 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
408 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
412 #ifdef FRAME_FIND_SAVED_REGS
413 /* XXX - deprecated */
414 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
415 extern void get_frame_saved_regs (struct frame_info *,
416 struct frame_saved_regs *);
419 extern struct block *get_frame_block (struct frame_info *,
420 CORE_ADDR *addr_in_block);
422 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
424 extern struct symbol *get_frame_function (struct frame_info *);
426 extern CORE_ADDR frame_address_in_block (struct frame_info *);
428 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
430 extern struct block *block_for_pc (CORE_ADDR);
432 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
434 extern int frameless_look_for_prologue (struct frame_info *);
436 extern void print_frame_args (struct symbol *, struct frame_info *,
437 int, struct ui_file *);
439 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
441 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
444 extern void print_stack_frame (struct frame_info *, int, int);
446 extern void print_only_stack_frame (struct frame_info *, int, int);
448 extern void show_stack_frame (struct frame_info *);
450 extern void print_frame_info (struct frame_info *, int, int, int);
452 extern void show_frame_info (struct frame_info *, int, int, int);
454 extern struct frame_info *block_innermost_frame (struct block *);
456 /* NOTE: cagney/2002-09-13: There is no need for this function.
457 Instead either of frame_unwind_signed_register() or
458 frame_unwind_unsigned_register() can be used. */
459 extern CORE_ADDR deprecated_read_register_dummy (CORE_ADDR pc,
461 extern void generic_push_dummy_frame (void);
462 extern void generic_pop_current_frame (void (*)(struct frame_info *));
463 extern void generic_pop_dummy_frame (void);
465 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
466 CORE_ADDR sp, CORE_ADDR fp);
468 /* NOTE: cagney/2002-06-26: Targets should no longer use this
469 function. Instead, the contents of a dummy frames registers can be
470 obtained by applying: frame_register_unwind to the dummy frame; or
471 get_saved_register to the next outer frame. */
473 extern char *deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
475 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
476 int nargs, struct value **args,
477 struct type *type, int gcc_p);
479 /* The function generic_get_saved_register() has been made obsolete.
480 GET_SAVED_REGISTER now defaults to the recursive equivalent -
481 generic_unwind_get_saved_register() - so there is no need to even
482 set GET_SAVED_REGISTER. Architectures that need to override the
483 register unwind mechanism should modify frame->unwind(). */
484 extern void deprecated_generic_get_saved_register (char *, int *, CORE_ADDR *,
485 struct frame_info *, int,
488 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
490 extern void get_saved_register (char *raw_buffer, int *optimized,
492 struct frame_info *frame,
493 int regnum, enum lval_type *lval);
495 extern int frame_register_read (struct frame_info *frame, int regnum,
499 extern void args_info (char *, int);
501 extern void locals_info (char *, int);
503 extern void (*selected_frame_level_changed_hook) (int);
505 extern void return_command (char *, int);
508 /* NOTE: cagney/2002-11-27:
510 You might think that the below global can simply be replaced by a
511 call to either get_selected_frame() or select_frame().
513 Unfortunatly, it isn't that easy.
515 The relevant code needs to be audited to determine if it is
516 possible (or pratical) to instead pass the applicable frame in as a
517 parameter. For instance, DEPRECATED_DO_REGISTERS_INFO() relied on
518 the selected_frame global, but its replacement,
519 PRINT_REGISTERS_INFO(), is parameterized with the selected frame.
520 The only real exceptions occure at the edge (in the CLI code) where
521 user commands need to pick up the selected frame before proceeding.
523 This is important. GDB is trying to stamp out the hack:
525 saved_frame = selected_frame;
526 selected_frame = ...;
527 hack_using_global_selected_frame ();
528 selected_frame = saved_frame;
532 extern struct frame_info *selected_frame;
535 /* NOTE: cagney/2002-11-28:
537 These functions are used to explicitly create and set the inner
538 most (current) frame vis:
540 set_current_frame (create_new_frame (read_fp(), stop_pc)));
542 Such code should be removed. Instead that task can be left to
543 get_current_frame() which will update things on-demand.
545 The only vague exception is found in "infcmd.c" (and a few
546 architectures specific files) as part of the code implementing the
547 command ``(gdb) frame FRAME PC''. There, the frame should be
548 created/selected in a single shot. */
550 extern void set_current_frame (struct frame_info *);
551 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
553 #endif /* !defined (FRAME_H) */