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 /* Return the frame's type.  Some are real, some are signal
  97    trampolines, and some are completly artificial (dummy).  */
  98
  99 enum frame_type
 100 {
 101   /* A true stack frame, created by the target program during normal
 102      execution.  */
 103   NORMAL_FRAME,
 104   /* A fake frame, created by GDB when performing an inferior function
 105      call.  */
 106   DUMMY_FRAME,
 107   /* In a signal handler, various OSs handle this in various ways.
 108      The main thing is that the frame may be far from normal.  */
 109   SIGTRAMP_FRAME
 110 };
 111 extern enum frame_type get_frame_type (struct frame_info *);
 112
 113 /* FIXME: cagney/2002-11-10: Some targets want to directly mark a
 114    frame as being of a specific type.  This shouldn't be necessary.
 115    PC_IN_SIGTRAMP() indicates a SIGTRAMP_FRAME and PC_IN_CALL_DUMMY()
 116    indicates a DUMMY_FRAME.  I suspect the real problem here is that
 117    get_prev_frame() only sets initialized after INIT_EXTRA_FRAME_INFO
 118    as been called.  Consequently, some targets found that the frame's
 119    type was wrong and tried to fix it.  The correct fix is to modify
 120    get_prev_frame() so that it initializes the frame's type before
 121    calling any other functions.  */
 122 extern void deprecated_set_frame_type (struct frame_info *,
 123                                        enum frame_type type);
 124
 125 /* Unwind the stack frame so that the value of REGNUM, in the previous
 126    (up, older) frame is returned.  If VALUEP is NULL, don't
 127    fetch/compute the value.  Instead just return the location of the
 128    value.  */
 129 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 130                                    int *optimizedp, enum lval_type *lvalp,
 131                                    CORE_ADDR *addrp, int *realnump,
 132                                    void *valuep);
 133
 134 /* More convenient interface to frame_register_unwind().  */
 135 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
 136    be changed to return an indication that the read succeeded.  */
 137
 138 extern void frame_unwind_signed_register (struct frame_info *frame,
 139                                           int regnum, LONGEST *val);
 140
 141 extern void frame_unwind_unsigned_register (struct frame_info *frame,
 142                                             int regnum, ULONGEST *val);
 143
 144 /* Get the value of the register that belongs to this FRAME.  This
 145    function is a wrapper to the call sequence ``frame_unwind_register
 146    (get_next_frame (FRAME))''.  As per frame_register_unwind(), if
 147    VALUEP is NULL, the registers value is not fetched/computed.  */
 148
 149 extern void frame_register (struct frame_info *frame, int regnum,
 150                             int *optimizedp, enum lval_type *lvalp,
 151                             CORE_ADDR *addrp, int *realnump,
 152                             void *valuep);
 153
 154 /* More convenient interface to frame_register().  */
 155 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
 156    be changed to return an indication that the read succeeded.  */
 157
 158 extern void frame_read_signed_register (struct frame_info *frame,
 159                                         int regnum, LONGEST *val);
 160
 161 extern void frame_read_unsigned_register (struct frame_info *frame,
 162                                           int regnum, ULONGEST *val);
 163
 164 /* Map between a frame register number and its name.  A frame register
 165    space is a superset of the cooked register space --- it also
 166    includes builtin registers.  */
 167
 168 extern int frame_map_name_to_regnum (const char *name, int strlen);
 169 extern const char *frame_map_regnum_to_name (int regnum);
 170
 171 /* Unwind the PC.  Strictly speaking return the resume address of the
 172    calling frame.  For GDB, `pc' is the resume address and not a
 173    specific register.  */
 174
 175 extern CORE_ADDR frame_pc_unwind (struct frame_info *frame);
 176
 177 \f
 178 /* Return the location (and possibly value) of REGNUM for the previous
 179    (older, up) frame.  All parameters except VALUEP can be assumed to
 180    be non NULL.  When VALUEP is NULL, just the location of the
 181    register should be returned.
 182
 183    UNWIND_CACHE is provided as mechanism for implementing a per-frame
 184    local cache.  It's initial value being NULL.  Memory for that cache
 185    should be allocated using frame_obstack_alloc().
 186
 187    Register window architectures (eg SPARC) should note that REGNUM
 188    identifies the register for the previous frame.  For instance, a
 189    request for the value of "o1" for the previous frame would be found
 190    in the register "i1" in this FRAME.  */
 191
 192 typedef void (frame_register_unwind_ftype) (struct frame_info *frame,
 193                                             void **unwind_cache,
 194                                             int regnum,
 195                                             int *optimized,
 196                                             enum lval_type *lvalp,
 197                                             CORE_ADDR *addrp,
 198                                             int *realnump,
 199                                             void *valuep);
 200
 201 /* Same as for registers above, but return the address at which the
 202    calling frame would resume.  */
 203
 204 typedef CORE_ADDR (frame_pc_unwind_ftype) (struct frame_info *frame,
 205                                            void **unwind_cache);
 206
 207 /* Describe the saved registers of a frame.  */
 208
 209 #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS)
 210 /* XXXX - deprecated */
 211 struct frame_saved_regs
 212   {
 213     /* For each register R (except the SP), regs[R] is the address at
 214        which it was saved on entry to the frame, or zero if it was not
 215        saved on entry to this frame.  This includes special registers
 216        such as pc and fp saved in special ways in the stack frame.
 217
 218        regs[SP_REGNUM] is different.  It holds the actual SP, not the
 219        address at which it was saved.  */
 220
 221     CORE_ADDR regs[NUM_REGS];
 222   };
 223 #endif
 224
 225 /* We keep a cache of stack frames, each of which is a "struct
 226    frame_info".  The innermost one gets allocated (in
 227    wait_for_inferior) each time the inferior stops; current_frame
 228    points to it.  Additional frames get allocated (in
 229    get_prev_frame) as needed, and are chained through the next
 230    and prev fields.  Any time that the frame cache becomes invalid
 231    (most notably when we execute something, but also if we change how
 232    we interpret the frames (e.g. "set heuristic-fence-post" in
 233    mips-tdep.c, or anything which reads new symbols)), we should call
 234    reinit_frame_cache.  */
 235
 236 struct frame_info
 237   {
 238     /* Nominal address of the frame described.  See comments at FRAME_FP
 239        about what this means outside the *FRAME* macros; in the *FRAME*
 240        macros, it can mean whatever makes most sense for this machine.  */
 241     CORE_ADDR frame;
 242
 243     /* Address at which execution is occurring in this frame.
 244        For the innermost frame, it's the current pc.
 245        For other frames, it is a pc saved in the next frame.  */
 246     CORE_ADDR pc;
 247
 248     /* Level of this frame.  The inner-most (youngest) frame is at
 249        level 0.  As you move towards the outer-most (oldest) frame,
 250        the level increases.  This is a cached value.  It could just as
 251        easily be computed by counting back from the selected frame to
 252        the inner most frame.  */
 253     /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
 254        reserved to indicate a bogus frame - one that has been created
 255        just to keep GDB happy (GDB always needs a frame).  For the
 256        moment leave this as speculation.  */
 257     int level;
 258
 259     /* The frame's type.  */
 260     enum frame_type type;
 261
 262     /* For each register, address of where it was saved on entry to
 263        the frame, or zero if it was not saved on entry to this frame.
 264        This includes special registers such as pc and fp saved in
 265        special ways in the stack frame.  The SP_REGNUM is even more
 266        special, the address here is the sp for the previous frame, not
 267        the address where the sp was saved.  */
 268     /* Allocated by frame_saved_regs_zalloc () which is called /
 269        initialized by FRAME_INIT_SAVED_REGS(). */
 270     CORE_ADDR *saved_regs;      /*NUM_REGS + NUM_PSEUDO_REGS*/
 271
 272 #ifdef EXTRA_FRAME_INFO
 273     /* XXXX - deprecated */
 274     /* Anything extra for this structure that may have been defined
 275        in the machine dependent files. */
 276       EXTRA_FRAME_INFO
 277 #endif
 278
 279     /* Anything extra for this structure that may have been defined
 280        in the machine dependent files. */
 281     /* Allocated by frame_obstack_alloc () which is called /
 282        initialized by INIT_EXTRA_FRAME_INFO */
 283     struct frame_extra_info *extra_info;
 284
 285     /* If dwarf2 unwind frame informations is used, this structure holds all
 286        related unwind data.  */
 287     struct context *context;
 288
 289     /* Unwind cache shared between the unwind functions - they had
 290        better all agree as to the contents.  */
 291     void *unwind_cache;
 292
 293     /* See description above.  The previous frame's registers.  */
 294     frame_register_unwind_ftype *register_unwind;
 295
 296     /* See description above.  The previous frame's resume address.
 297        Save the previous PC in a local cache.  */
 298     frame_pc_unwind_ftype *pc_unwind;
 299     int pc_unwind_cache_p;
 300     CORE_ADDR pc_unwind_cache;
 301
 302     /* Pointers to the next (down, inner, younger) and previous (up,
 303        outer, older) frame_info's in the frame cache.  */
 304     struct frame_info *next; /* down, inner, younger */
 305     int prev_p;
 306     struct frame_info *prev; /* up, outer, older */
 307   };
 308
 309 /* Values for the source flag to be used in print_frame_info_base(). */
 310 enum print_what
 311   {
 312     /* Print only the source line, like in stepi. */
 313     SRC_LINE = -1,
 314     /* Print only the location, i.e. level, address (sometimes)
 315        function, args, file, line, line num. */
 316     LOCATION,
 317     /* Print both of the above. */
 318     SRC_AND_LOC,
 319     /* Print location only, but always include the address. */
 320     LOC_AND_ADDRESS
 321   };
 322
 323 /* Allocate additional space for appendices to a struct frame_info.
 324    NOTE: Much of GDB's code works on the assumption that the allocated
 325    saved_regs[] array is the size specified below.  If you try to make
 326    that array smaller, GDB will happily walk off its end. */
 327
 328 #ifdef SIZEOF_FRAME_SAVED_REGS
 329 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 330 #endif
 331 #define SIZEOF_FRAME_SAVED_REGS \
 332         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 333
 334 extern void *frame_obstack_alloc (unsigned long size);
 335 extern void frame_saved_regs_zalloc (struct frame_info *);
 336
 337 /* Return the frame address from FI.  Except in the machine-dependent
 338    *FRAME* macros, a frame address has no defined meaning other than
 339    as a magic cookie which identifies a frame over calls to the
 340    inferior.  The only known exception is inferior.h
 341    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
 342    assume that a frame address contains enough information to
 343    reconstruct the frame; if you want more than just to identify the
 344    frame (e.g. be able to fetch variables relative to that frame),
 345    then save the whole struct frame_info (and the next struct
 346    frame_info, since the latter is used for fetching variables on some
 347    machines).  */
 348
 349 #define FRAME_FP(fi) ((fi)->frame)
 350
 351 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 352    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 353    is the outermost one and has no caller.
 354
 355    XXXX - both default and alternate frame_chain_valid functions are
 356    deprecated.  New code should use dummy frames and one of the
 357    generic functions. */
 358
 359 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 360 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 361 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
 362 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 363 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 364 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
 365
 366 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
 367
 368
 369 #ifdef FRAME_FIND_SAVED_REGS
 370 /* XXX - deprecated */
 371 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
 372 extern void get_frame_saved_regs (struct frame_info *,
 373                                   struct frame_saved_regs *);
 374 #endif
 375
 376 extern struct block *get_frame_block (struct frame_info *,
 377                                       CORE_ADDR *addr_in_block);
 378
 379 extern struct block *get_current_block (CORE_ADDR *addr_in_block);
 380
 381 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 382
 383 extern struct symbol *get_frame_function (struct frame_info *);
 384
 385 extern CORE_ADDR frame_address_in_block (struct frame_info *);
 386
 387 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 388
 389 extern struct block *block_for_pc (CORE_ADDR);
 390
 391 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 392
 393 extern int frameless_look_for_prologue (struct frame_info *);
 394
 395 extern void print_frame_args (struct symbol *, struct frame_info *,
 396                               int, struct ui_file *);
 397
 398 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 399
 400 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
 401                                         int source);
 402
 403 extern void print_stack_frame (struct frame_info *, int, int);
 404
 405 extern void print_only_stack_frame (struct frame_info *, int, int);
 406
 407 extern void show_stack_frame (struct frame_info *);
 408
 409 extern void print_frame_info (struct frame_info *, int, int, int);
 410
 411 extern void show_frame_info (struct frame_info *, int, int, int);
 412
 413 extern struct frame_info *block_innermost_frame (struct block *);
 414
 415 extern struct frame_info *find_frame_addr_in_frame_chain (CORE_ADDR);
 416
 417 /* NOTE: cagney/2002-09-13: There is no need for this function.
 418    Instead either of frame_unwind_signed_register() or
 419    frame_unwind_unsigned_register() can be used.  */
 420 extern CORE_ADDR deprecated_read_register_dummy (CORE_ADDR pc,
 421                                                  CORE_ADDR fp, int);
 422 extern void generic_push_dummy_frame (void);
 423 extern void generic_pop_current_frame (void (*)(struct frame_info *));
 424 extern void generic_pop_dummy_frame (void);
 425
 426 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
 427                                      CORE_ADDR sp, CORE_ADDR fp);
 428
 429 /* NOTE: cagney/2002-06-26: Targets should no longer use this
 430    function.  Instead, the contents of a dummy frames registers can be
 431    obtained by applying: frame_register_unwind to the dummy frame; or
 432    get_saved_register to the next outer frame.  */
 433
 434 extern char *deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
 435
 436 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 437                                     int nargs, struct value **args,
 438                                     struct type *type, int gcc_p);
 439
 440 /* The function generic_get_saved_register() has been made obsolete.
 441    GET_SAVED_REGISTER now defaults to the recursive equivalent -
 442    generic_unwind_get_saved_register() - so there is no need to even
 443    set GET_SAVED_REGISTER.  Architectures that need to override the
 444    register unwind mechanism should modify frame->unwind().  */
 445 extern void deprecated_generic_get_saved_register (char *, int *, CORE_ADDR *,
 446                                                    struct frame_info *, int,
 447                                                    enum lval_type *);
 448
 449 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
 450
 451 extern void get_saved_register (char *raw_buffer, int *optimized,
 452                                 CORE_ADDR * addrp,
 453                                 struct frame_info *frame,
 454                                 int regnum, enum lval_type *lval);
 455
 456 extern int frame_register_read (struct frame_info *frame, int regnum,
 457                                 void *buf);
 458
 459 /* From stack.c.  */
 460 extern void args_info (char *, int);
 461
 462 extern void locals_info (char *, int);
 463
 464 extern void (*selected_frame_level_changed_hook) (int);
 465
 466 extern void return_command (char *, int);
 467
 468 #endif /* !defined (FRAME_H)  */