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 /* Unwind the PC.  Strictly speaking return the resume address of the
 143    calling frame.  For GDB, `pc' is the resume address and not a
 144    specific register.  */
 145
 146 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
 147
 148 \f
 149 /* Return the location (and possibly value) of REGNUM for the previous
 150    (older, up) frame.  All parameters except VALUEP can be assumed to
 151    be non NULL.  When VALUEP is NULL, just the location of the
 152    register should be returned.
 153
 154    UNWIND_CACHE is provided as mechanism for implementing a per-frame
 155    local cache.  It's initial value being NULL.  Memory for that cache
 156    should be allocated using frame_obstack_alloc().
 157
 158    Register window architectures (eg SPARC) should note that REGNUM
 159    identifies the register for the previous frame.  For instance, a
 160    request for the value of "o1" for the previous frame would be found
 161    in the register "i1" in this FRAME.  */
 162
 163 typedef void (frame_register_unwind_ftype) (struct frame_info *frame,
 164                                             void **unwind_cache,
 165                                             int regnum,
 166                                             int *optimized,
 167                                             enum lval_type *lvalp,
 168                                             CORE_ADDR *addrp,
 169                                             int *realnump,
 170                                             void *valuep);
 171
 172 /* Same as for registers above, but return the address at which the
 173    calling frame would resume.  */
 174
 175 typedef CORE_ADDR (frame_pc_unwind_ftype) (struct frame_info *frame,
 176                                            void **unwind_cache);
 177
 178 /* Describe the saved registers of a frame.  */
 179
 180 #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS)
 181 /* XXXX - deprecated */
 182 struct frame_saved_regs
 183   {
 184     /* For each register R (except the SP), regs[R] is the address at
 185        which it was saved on entry to the frame, or zero if it was not
 186        saved on entry to this frame.  This includes special registers
 187        such as pc and fp saved in special ways in the stack frame.
 188
 189        regs[SP_REGNUM] is different.  It holds the actual SP, not the
 190        address at which it was saved.  */
 191
 192     CORE_ADDR regs[NUM_REGS];
 193   };
 194 #endif
 195
 196 /* We keep a cache of stack frames, each of which is a "struct
 197    frame_info".  The innermost one gets allocated (in
 198    wait_for_inferior) each time the inferior stops; current_frame
 199    points to it.  Additional frames get allocated (in
 200    get_prev_frame) as needed, and are chained through the next
 201    and prev fields.  Any time that the frame cache becomes invalid
 202    (most notably when we execute something, but also if we change how
 203    we interpret the frames (e.g. "set heuristic-fence-post" in
 204    mips-tdep.c, or anything which reads new symbols)), we should call
 205    reinit_frame_cache.  */
 206
 207 struct frame_info
 208   {
 209     /* Nominal address of the frame described.  See comments at FRAME_FP
 210        about what this means outside the *FRAME* macros; in the *FRAME*
 211        macros, it can mean whatever makes most sense for this machine.  */
 212     CORE_ADDR frame;
 213
 214     /* Address at which execution is occurring in this frame.
 215        For the innermost frame, it's the current pc.
 216        For other frames, it is a pc saved in the next frame.  */
 217     CORE_ADDR pc;
 218
 219     /* Level of this frame.  The inner-most (youngest) frame is at
 220        level 0.  As you move towards the outer-most (oldest) frame,
 221        the level increases.  This is a cached value.  It could just as
 222        easily be computed by counting back from the selected frame to
 223        the inner most frame.  */
 224     /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
 225        reserved to indicate a bogus frame - one that has been created
 226        just to keep GDB happy (GDB always needs a frame).  For the
 227        moment leave this as speculation.  */
 228     int level;
 229
 230     /* Nonzero if this is a frame associated with calling a signal handler.
 231
 232        Set by machine-dependent code.  On some machines, if
 233        the machine-dependent code fails to check for this, the backtrace
 234        will look relatively normal.  For example, on the i386
 235        #3  0x158728 in sighold ()
 236        On other machines (e.g. rs6000), the machine-dependent code better
 237        set this to prevent us from trying to print it like a normal frame.  */
 238     int signal_handler_caller;
 239
 240     /* For each register, address of where it was saved on entry to
 241        the frame, or zero if it was not saved on entry to this frame.
 242        This includes special registers such as pc and fp saved in
 243        special ways in the stack frame.  The SP_REGNUM is even more
 244        special, the address here is the sp for the previous frame, not
 245        the address where the sp was saved.  */
 246     /* Allocated by frame_saved_regs_zalloc () which is called /
 247        initialized by FRAME_INIT_SAVED_REGS(). */
 248     CORE_ADDR *saved_regs;      /*NUM_REGS + NUM_PSEUDO_REGS*/
 249
 250 #ifdef EXTRA_FRAME_INFO
 251     /* XXXX - deprecated */
 252     /* Anything extra for this structure that may have been defined
 253        in the machine dependent files. */
 254       EXTRA_FRAME_INFO
 255 #endif
 256
 257     /* Anything extra for this structure that may have been defined
 258        in the machine dependent files. */
 259     /* Allocated by frame_obstack_alloc () which is called /
 260        initialized by INIT_EXTRA_FRAME_INFO */
 261     struct frame_extra_info *extra_info;
 262
 263     /* If dwarf2 unwind frame informations is used, this structure holds all
 264        related unwind data.  */
 265     struct context *context;
 266
 267     /* Unwind cache shared between the unwind functions - they had
 268        better all agree as to the contents.  */
 269     void *unwind_cache;
 270
 271     /* See description above.  The previous frame's registers.  */
 272     frame_register_unwind_ftype *register_unwind;
 273
 274     /* See description above.  The previous frame's resume address.
 275        Save the previous PC in a local cache.  */
 276     frame_pc_unwind_ftype *pc_unwind;
 277     int pc_unwind_cache_p;
 278     CORE_ADDR pc_unwind_cache;
 279
 280     /* Pointers to the next (down, inner, younger) and previous (up,
 281        outer, older) frame_info's in the frame cache.  */
 282     struct frame_info *next; /* down, inner, younger */
 283     int prev_p;
 284     struct frame_info *prev; /* up, outer, older */
 285   };
 286
 287 /* Values for the source flag to be used in print_frame_info_base(). */
 288 enum print_what
 289   {
 290     /* Print only the source line, like in stepi. */
 291     SRC_LINE = -1,
 292     /* Print only the location, i.e. level, address (sometimes)
 293        function, args, file, line, line num. */
 294     LOCATION,
 295     /* Print both of the above. */
 296     SRC_AND_LOC,
 297     /* Print location only, but always include the address. */
 298     LOC_AND_ADDRESS
 299   };
 300
 301 /* Allocate additional space for appendices to a struct frame_info.
 302    NOTE: Much of GDB's code works on the assumption that the allocated
 303    saved_regs[] array is the size specified below.  If you try to make
 304    that array smaller, GDB will happily walk off its end. */
 305
 306 #ifdef SIZEOF_FRAME_SAVED_REGS
 307 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 308 #endif
 309 #define SIZEOF_FRAME_SAVED_REGS \
 310         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 311
 312 extern void *frame_obstack_alloc (unsigned long size);
 313 extern void frame_saved_regs_zalloc (struct frame_info *);
 314
 315 /* Return the frame address from FI.  Except in the machine-dependent
 316    *FRAME* macros, a frame address has no defined meaning other than
 317    as a magic cookie which identifies a frame over calls to the
 318    inferior.  The only known exception is inferior.h
 319    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
 320    assume that a frame address contains enough information to
 321    reconstruct the frame; if you want more than just to identify the
 322    frame (e.g. be able to fetch variables relative to that frame),
 323    then save the whole struct frame_info (and the next struct
 324    frame_info, since the latter is used for fetching variables on some
 325    machines).  */
 326
 327 #define FRAME_FP(fi) ((fi)->frame)
 328
 329 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 330    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 331    is the outermost one and has no caller.
 332
 333    XXXX - both default and alternate frame_chain_valid functions are
 334    deprecated.  New code should use dummy frames and one of the
 335    generic functions. */
 336
 337 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 338 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 339 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
 340 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 341 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 342 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
 343
 344 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
 345
 346
 347 #ifdef FRAME_FIND_SAVED_REGS
 348 /* XXX - deprecated */
 349 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
 350 extern void get_frame_saved_regs (struct frame_info *,
 351                                   struct frame_saved_regs *);
 352 #endif
 353
 354 extern struct block *get_frame_block (struct frame_info *,
 355                                       CORE_ADDR *addr_in_block);
 356
 357 extern struct block *get_current_block (CORE_ADDR *addr_in_block);
 358
 359 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 360
 361 extern struct symbol *get_frame_function (struct frame_info *);
 362
 363 extern CORE_ADDR frame_address_in_block (struct frame_info *);
 364
 365 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 366
 367 extern struct block *block_for_pc (CORE_ADDR);
 368
 369 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 370
 371 extern int frameless_look_for_prologue (struct frame_info *);
 372
 373 extern void print_frame_args (struct symbol *, struct frame_info *,
 374                               int, struct ui_file *);
 375
 376 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 377
 378 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
 379                                         int source);
 380
 381 extern void print_stack_frame (struct frame_info *, int, int);
 382
 383 extern void print_only_stack_frame (struct frame_info *, int, int);
 384
 385 extern void show_stack_frame (struct frame_info *);
 386
 387 extern void print_frame_info (struct frame_info *, int, int, int);
 388
 389 extern void show_frame_info (struct frame_info *, int, int, int);
 390
 391 extern struct frame_info *block_innermost_frame (struct block *);
 392
 393 extern struct frame_info *find_frame_addr_in_frame_chain (CORE_ADDR);
 394
 395 /* NOTE: cagney/2002-09-13: There is no need for this function.
 396    Instead either of frame_unwind_signed_register() or
 397    frame_unwind_unsigned_register() can be used.  */
 398 extern CORE_ADDR deprecated_read_register_dummy (CORE_ADDR pc,
 399                                                  CORE_ADDR fp, int);
 400 extern void generic_push_dummy_frame (void);
 401 extern void generic_pop_current_frame (void (*)(struct frame_info *));
 402 extern void generic_pop_dummy_frame (void);
 403
 404 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
 405                                      CORE_ADDR sp, CORE_ADDR fp);
 406
 407 /* NOTE: cagney/2002-06-26: Targets should no longer use this
 408    function.  Instead, the contents of a dummy frames registers can be
 409    obtained by applying: frame_register_unwind to the dummy frame; or
 410    get_saved_register to the next outer frame.  */
 411
 412 extern char *deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
 413
 414 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 415                                     int nargs, struct value **args,
 416                                     struct type *type, int gcc_p);
 417
 418 /* The function generic_get_saved_register() has been made obsolete.
 419    GET_SAVED_REGISTER now defaults to the recursive equivalent -
 420    generic_unwind_get_saved_register() - so there is no need to even
 421    set GET_SAVED_REGISTER.  Architectures that need to override the
 422    register unwind mechanism should modify frame->unwind().  */
 423 extern void deprecated_generic_get_saved_register (char *, int *, CORE_ADDR *,
 424                                                    struct frame_info *, int,
 425                                                    enum lval_type *);
 426
 427 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
 428
 429 extern void get_saved_register (char *raw_buffer, int *optimized,
 430                                 CORE_ADDR * addrp,
 431                                 struct frame_info *frame,
 432                                 int regnum, enum lval_type *lval);
 433
 434 extern int frame_register_read (struct frame_info *frame, int regnum,
 435                                 void *buf);
 436
 437 /* From stack.c.  */
 438 extern void args_info (char *, int);
 439
 440 extern void locals_info (char *, int);
 441
 442 extern void (*selected_frame_level_changed_hook) (int);
 443
 444 extern void return_command (char *, int);
 445
 446 #endif /* !defined (FRAME_H)  */