gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2
   3    Copyright 1986, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1996,
   4    1997, 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   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.
  12
  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.
  17
  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.  */
  22
  23 #if !defined (FRAME_H)
  24 #define FRAME_H 1
  25
  26 /* The frame object.  */
  27
  28 struct frame_info;
  29
  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).  */
  34
  35 struct frame_id
  36 {
  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.  */
  41   CORE_ADDR base;
  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?  */
  45   CORE_ADDR pc;
  46 };
  47
  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 frame currently being examined via
  51    the GDB CLI (selected using `up', `down', ...).  The frames are
  52    created on-demand (via get_prev_frame()) and then held in a frame
  53    cache.  Provide mechanims for controlling these frames.  */
  54 /* FIXME: cagney/2002-11-14: At any time, only one thread's selected
  55    and current frame can be active.  Switching threads causes gdb to
  56    discard all that cached frame information.  Ulgh!  Instead, current
  57    and selected frame should be bound to a thread.  */
  58
  59 extern struct frame_info *selected_frame;
  60 extern void select_frame (struct frame_info *);
  61 extern void set_current_frame (struct frame_info *);
  62 extern struct frame_info *get_current_frame (void);
  63
  64 /* Invalidates the frame cache.  */
  65 extern void flush_cached_frames (void);
  66
  67 /* Flushes the frame cache and then selects the inner most (aka
  68    current) frame - it changes selected frame.  */
  69 /* FIXME: cagney/2002-11-14: Should this re-select the selected frame
  70    from before the flush?  */
  71 extern void reinit_frame_cache (void);
  72
  73 /* Given a FRAME, return the next (more inner, younger) or previous
  74    (more outer, older) frame.  */
  75 extern struct frame_info *get_prev_frame (struct frame_info *);
  76 extern struct frame_info *get_next_frame (struct frame_info *);
  77
  78 /* Given a frame's ID, relocate the frame.  Returns NULL if the frame
  79    is not found.  */
  80 extern struct frame_info *frame_find_by_id (struct frame_id id);
  81
  82 /* Base attributes of a frame: */
  83
  84 /* The frame's `resume' address.  Where the program will resume in
  85    this frame.  */
  86 extern CORE_ADDR get_frame_pc (struct frame_info *);
  87
  88 /* Return the per-frame unique identifer.  Can be used to relocate a
  89    frame after a frame cache flush (and other similar operations).  */
  90 extern void get_frame_id (struct frame_info *fi, struct frame_id *id);
  91
  92 /* The frame's level: 0 for innermost, 1 for its caller, ...; or -1
  93    for an invalid frame).  */
  94 extern int frame_relative_level (struct frame_info *fi);
  95
  96 /* Unwind the stack frame so that the value of REGNUM, in the previous
  97    (up, older) frame is returned.  If VALUEP is NULL, don't
  98    fetch/compute the value.  Instead just return the location of the
  99    value.  */
 100 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 101                                    int *optimizedp, enum lval_type *lvalp,
 102                                    CORE_ADDR *addrp, int *realnump,
 103                                    void *valuep);
 104
 105 /* More convenient interface to frame_register_unwind().  */
 106 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
 107    be changed to return an indication that the read succeeded.  */
 108
 109 extern void frame_unwind_signed_register (struct frame_info *frame,
 110                                           int regnum, LONGEST *val);
 111
 112 extern void frame_unwind_unsigned_register (struct frame_info *frame,
 113                                             int regnum, ULONGEST *val);
 114
 115 /* Get the value of the register that belongs to this FRAME.  This
 116    function is a wrapper to the call sequence ``frame_unwind_register
 117    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 118    VALUEP is NULL, the registers value is not fetched/computed.  */
 119
 120 extern void frame_register (struct frame_info *frame, int regnum,
 121                             int *optimizedp, enum lval_type *lvalp,
 122                             CORE_ADDR *addrp, int *realnump,
 123                             void *valuep);
 124
 125 /* More convenient interface to frame_register().  */
 126 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
 127    be changed to return an indication that the read succeeded.  */
 128
 129 extern void frame_read_signed_register (struct frame_info *frame,
 130                                         int regnum, LONGEST *val);
 131
 132 extern void frame_read_unsigned_register (struct frame_info *frame,
 133                                           int regnum, ULONGEST *val);
 134
 135 /* Map between a frame register number and its name.  A frame register
 136    space is a superset of the cooked register space --- it also
 137    includes builtin registers.  */
 138
 139 extern int frame_map_name_to_regnum (const char *name, int strlen);
 140 extern const char *frame_map_regnum_to_name (int regnum);
 141
 142 \f
 143 /* Return the location (and possibly value) of REGNUM for the previous
 144    (older, up) frame.  All parameters except VALUEP can be assumed to
 145    be non NULL.  When VALUEP is NULL, just the location of the
 146    register should be returned.
 147
 148    UNWIND_CACHE is provided as mechanism for implementing a per-frame
 149    local cache.  It's initial value being NULL.  Memory for that cache
 150    should be allocated using frame_obstack_alloc().
 151
 152    Register window architectures (eg SPARC) should note that REGNUM
 153    identifies the register for the previous frame.  For instance, a
 154    request for the value of "o1" for the previous frame would be found
 155    in the register "i1" in this FRAME.  */
 156
 157 typedef void (frame_register_unwind_ftype) (struct frame_info *frame,
 158                                             void **unwind_cache,
 159                                             int regnum,
 160                                             int *optimized,
 161                                             enum lval_type *lvalp,
 162                                             CORE_ADDR *addrp,
 163                                             int *realnump,
 164                                             void *valuep);
 165
 166 /* Describe the saved registers of a frame.  */
 167
 168 #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS)
 169 /* XXXX - deprecated */
 170 struct frame_saved_regs
 171   {
 172     /* For each register R (except the SP), regs[R] is the address at
 173        which it was saved on entry to the frame, or zero if it was not
 174        saved on entry to this frame.  This includes special registers
 175        such as pc and fp saved in special ways in the stack frame.
 176
 177        regs[SP_REGNUM] is different.  It holds the actual SP, not the
 178        address at which it was saved.  */
 179
 180     CORE_ADDR regs[NUM_REGS];
 181   };
 182 #endif
 183
 184 /* We keep a cache of stack frames, each of which is a "struct
 185    frame_info".  The innermost one gets allocated (in
 186    wait_for_inferior) each time the inferior stops; current_frame
 187    points to it.  Additional frames get allocated (in
 188    get_prev_frame) as needed, and are chained through the next
 189    and prev fields.  Any time that the frame cache becomes invalid
 190    (most notably when we execute something, but also if we change how
 191    we interpret the frames (e.g. "set heuristic-fence-post" in
 192    mips-tdep.c, or anything which reads new symbols)), we should call
 193    reinit_frame_cache.  */
 194
 195 struct frame_info
 196   {
 197     /* Nominal address of the frame described.  See comments at FRAME_FP
 198        about what this means outside the *FRAME* macros; in the *FRAME*
 199        macros, it can mean whatever makes most sense for this machine.  */
 200     CORE_ADDR frame;
 201
 202     /* Address at which execution is occurring in this frame.
 203        For the innermost frame, it's the current pc.
 204        For other frames, it is a pc saved in the next frame.  */
 205     CORE_ADDR pc;
 206
 207     /* Level of this frame.  The inner-most (youngest) frame is at
 208        level 0.  As you move towards the outer-most (oldest) frame,
 209        the level increases.  This is a cached value.  It could just as
 210        easily be computed by counting back from the selected frame to
 211        the inner most frame.  */
 212     /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
 213        reserved to indicate a bogus frame - one that has been created
 214        just to keep GDB happy (GDB always needs a frame).  For the
 215        moment leave this as speculation.  */
 216     int level;
 217
 218     /* Nonzero if this is a frame associated with calling a signal handler.
 219
 220        Set by machine-dependent code.  On some machines, if
 221        the machine-dependent code fails to check for this, the backtrace
 222        will look relatively normal.  For example, on the i386
 223        #3  0x158728 in sighold ()
 224        On other machines (e.g. rs6000), the machine-dependent code better
 225        set this to prevent us from trying to print it like a normal frame.  */
 226     int signal_handler_caller;
 227
 228     /* For each register, address of where it was saved on entry to
 229        the frame, or zero if it was not saved on entry to this frame.
 230        This includes special registers such as pc and fp saved in
 231        special ways in the stack frame.  The SP_REGNUM is even more
 232        special, the address here is the sp for the previous frame, not
 233        the address where the sp was saved.  */
 234     /* Allocated by frame_saved_regs_zalloc () which is called /
 235        initialized by FRAME_INIT_SAVED_REGS(). */
 236     CORE_ADDR *saved_regs;      /*NUM_REGS + NUM_PSEUDO_REGS*/
 237
 238 #ifdef EXTRA_FRAME_INFO
 239     /* XXXX - deprecated */
 240     /* Anything extra for this structure that may have been defined
 241        in the machine dependent files. */
 242       EXTRA_FRAME_INFO
 243 #endif
 244
 245     /* Anything extra for this structure that may have been defined
 246        in the machine dependent files. */
 247     /* Allocated by frame_obstack_alloc () which is called /
 248        initialized by INIT_EXTRA_FRAME_INFO */
 249     struct frame_extra_info *extra_info;
 250
 251     /* If dwarf2 unwind frame informations is used, this structure holds all
 252        related unwind data.  */
 253     struct context *context;
 254
 255     /* See description above.  Return the register value for the
 256        previous frame.  */
 257     frame_register_unwind_ftype *register_unwind;
 258     void *register_unwind_cache;
 259
 260     /* Pointers to the next (down, inner, younger) and previous (up,
 261        outer, older) frame_info's in the frame cache.  */
 262     struct frame_info *next; /* down, inner, younger */
 263     int prev_p;
 264     struct frame_info *prev; /* up, outer, older */
 265   };
 266
 267 /* Values for the source flag to be used in print_frame_info_base(). */
 268 enum print_what
 269   {
 270     /* Print only the source line, like in stepi. */
 271     SRC_LINE = -1,
 272     /* Print only the location, i.e. level, address (sometimes)
 273        function, args, file, line, line num. */
 274     LOCATION,
 275     /* Print both of the above. */
 276     SRC_AND_LOC,
 277     /* Print location only, but always include the address. */
 278     LOC_AND_ADDRESS
 279   };
 280
 281 /* Allocate additional space for appendices to a struct frame_info.
 282    NOTE: Much of GDB's code works on the assumption that the allocated
 283    saved_regs[] array is the size specified below.  If you try to make
 284    that array smaller, GDB will happily walk off its end. */
 285
 286 #ifdef SIZEOF_FRAME_SAVED_REGS
 287 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 288 #endif
 289 #define SIZEOF_FRAME_SAVED_REGS \
 290         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 291
 292 extern void *frame_obstack_alloc (unsigned long size);
 293 extern void frame_saved_regs_zalloc (struct frame_info *);
 294
 295 /* Return the frame address from FI.  Except in the machine-dependent
 296    *FRAME* macros, a frame address has no defined meaning other than
 297    as a magic cookie which identifies a frame over calls to the
 298    inferior.  The only known exception is inferior.h
 299    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
 300    assume that a frame address contains enough information to
 301    reconstruct the frame; if you want more than just to identify the
 302    frame (e.g. be able to fetch variables relative to that frame),
 303    then save the whole struct frame_info (and the next struct
 304    frame_info, since the latter is used for fetching variables on some
 305    machines).  */
 306
 307 #define FRAME_FP(fi) ((fi)->frame)
 308
 309 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 310    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 311    is the outermost one and has no caller.
 312
 313    XXXX - both default and alternate frame_chain_valid functions are
 314    deprecated.  New code should use dummy frames and one of the
 315    generic functions. */
 316
 317 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 318 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 319 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
 320 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 321 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 322 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
 323
 324 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
 325
 326
 327 #ifdef FRAME_FIND_SAVED_REGS
 328 /* XXX - deprecated */
 329 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
 330 extern void get_frame_saved_regs (struct frame_info *,
 331                                   struct frame_saved_regs *);
 332 #endif
 333
 334 extern struct block *get_frame_block (struct frame_info *,
 335                                       CORE_ADDR *addr_in_block);
 336
 337 extern struct block *get_current_block (CORE_ADDR *addr_in_block);
 338
 339 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 340
 341 extern struct symbol *get_frame_function (struct frame_info *);
 342
 343 extern CORE_ADDR frame_address_in_block (struct frame_info *);
 344
 345 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 346
 347 extern struct block *block_for_pc (CORE_ADDR);
 348
 349 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 350
 351 extern int frameless_look_for_prologue (struct frame_info *);
 352
 353 extern void print_frame_args (struct symbol *, struct frame_info *,
 354                               int, struct ui_file *);
 355
 356 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 357
 358 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
 359                                         int source);
 360
 361 extern void print_stack_frame (struct frame_info *, int, int);
 362
 363 extern void print_only_stack_frame (struct frame_info *, int, int);
 364
 365 extern void show_stack_frame (struct frame_info *);
 366
 367 extern void print_frame_info (struct frame_info *, int, int, int);
 368
 369 extern void show_frame_info (struct frame_info *, int, int, int);
 370
 371 extern struct frame_info *block_innermost_frame (struct block *);
 372
 373 extern struct frame_info *find_frame_addr_in_frame_chain (CORE_ADDR);
 374
 375 extern CORE_ADDR sigtramp_saved_pc (struct frame_info *);
 376
 377 /* NOTE: cagney/2002-09-13: There is no need for this function.
 378    Instead either of frame_unwind_signed_register() or
 379    frame_unwind_unsigned_register() can be used.  */
 380 extern CORE_ADDR deprecated_read_register_dummy (CORE_ADDR pc,
 381                                                  CORE_ADDR fp, int);
 382 extern void generic_push_dummy_frame (void);
 383 extern void generic_pop_current_frame (void (*)(struct frame_info *));
 384 extern void generic_pop_dummy_frame (void);
 385
 386 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
 387                                      CORE_ADDR sp, CORE_ADDR fp);
 388
 389 /* NOTE: cagney/2002-06-26: Targets should no longer use this
 390    function.  Instead, the contents of a dummy frames registers can be
 391    obtained by applying: frame_register_unwind to the dummy frame; or
 392    get_saved_register to the next outer frame.  */
 393
 394 extern char *deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
 395
 396 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 397                                     int nargs, struct value **args,
 398                                     struct type *type, int gcc_p);
 399
 400 /* The function generic_get_saved_register() has been made obsolete.
 401    GET_SAVED_REGISTER now defaults to the recursive equivalent -
 402    generic_unwind_get_saved_register() - so there is no need to even
 403    set GET_SAVED_REGISTER.  Architectures that need to override the
 404    register unwind mechanism should modify frame->unwind().  */
 405 extern void deprecated_generic_get_saved_register (char *, int *, CORE_ADDR *,
 406                                                    struct frame_info *, int,
 407                                                    enum lval_type *);
 408
 409 extern void generic_unwind_get_saved_register (char *raw_buffer,
 410                                                int *optimized,
 411                                                CORE_ADDR * addrp,
 412                                                struct frame_info *frame,
 413                                                int regnum,
 414                                                enum lval_type *lval);
 415
 416 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
 417
 418 extern void get_saved_register (char *raw_buffer, int *optimized,
 419                                 CORE_ADDR * addrp,
 420                                 struct frame_info *frame,
 421                                 int regnum, enum lval_type *lval);
 422
 423 extern int frame_register_read (struct frame_info *frame, int regnum,
 424                                 void *buf);
 425
 426 /* From stack.c.  */
 427 extern void args_info (char *, int);
 428
 429 extern void locals_info (char *, int);
 430
 431 extern void (*selected_frame_level_changed_hook) (int);
 432
 433 extern void return_command (char *, int);
 434
 435 #endif /* !defined (FRAME_H)  */