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 /* Return the location (and possibly value) of REGNUM for the previous
  27    (older, up) frame.  All parameters except VALUEP can be assumed to
  28    be non NULL.  When VALUEP is NULL, just the location of the
  29    register should be returned.
  30
  31    UNWIND_CACHE is provided as mechanism for implementing a per-frame
  32    local cache.  It's initial value being NULL.  Memory for that cache
  33    should be allocated using frame_obstack_alloc().
  34
  35    Register window architectures (eg SPARC) should note that REGNUM
  36    identifies the register for the previous frame.  For instance, a
  37    request for the value of "o1" for the previous frame would be found
  38    in the register "i1" in this FRAME.  */
  39
  40 typedef void (frame_register_unwind_ftype) (struct frame_info *frame,
  41                                             void **unwind_cache,
  42                                             int regnum,
  43                                             int *optimized,
  44                                             enum lval_type *lvalp,
  45                                             CORE_ADDR *addrp,
  46                                             int *realnump,
  47                                             void *valuep);
  48
  49 /* Describe the saved registers of a frame.  */
  50
  51 #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS)
  52 /* XXXX - deprecated */
  53 struct frame_saved_regs
  54   {
  55     /* For each register R (except the SP), regs[R] is the address at
  56        which it was saved on entry to the frame, or zero if it was not
  57        saved on entry to this frame.  This includes special registers
  58        such as pc and fp saved in special ways in the stack frame.
  59
  60        regs[SP_REGNUM] is different.  It holds the actual SP, not the
  61        address at which it was saved.  */
  62
  63     CORE_ADDR regs[NUM_REGS];
  64   };
  65 #endif
  66
  67 /* We keep a cache of stack frames, each of which is a "struct
  68    frame_info".  The innermost one gets allocated (in
  69    wait_for_inferior) each time the inferior stops; current_frame
  70    points to it.  Additional frames get allocated (in
  71    get_prev_frame) as needed, and are chained through the next
  72    and prev fields.  Any time that the frame cache becomes invalid
  73    (most notably when we execute something, but also if we change how
  74    we interpret the frames (e.g. "set heuristic-fence-post" in
  75    mips-tdep.c, or anything which reads new symbols)), we should call
  76    reinit_frame_cache.  */
  77
  78 struct frame_info
  79   {
  80     /* Nominal address of the frame described.  See comments at FRAME_FP
  81        about what this means outside the *FRAME* macros; in the *FRAME*
  82        macros, it can mean whatever makes most sense for this machine.  */
  83     CORE_ADDR frame;
  84
  85     /* Address at which execution is occurring in this frame.
  86        For the innermost frame, it's the current pc.
  87        For other frames, it is a pc saved in the next frame.  */
  88     CORE_ADDR pc;
  89
  90     /* Level of this frame.  The inner-most (youngest) frame is at
  91        level 0.  As you move towards the outer-most (oldest) frame,
  92        the level increases.  This is a cached value.  It could just as
  93        easily be computed by counting back from the selected frame to
  94        the inner most frame.  */
  95     /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
  96        reserved to indicate a bogus frame - one that has been created
  97        just to keep GDB happy (GDB always needs a frame).  For the
  98        moment leave this as speculation.  */
  99     int level;
 100
 101     /* Nonzero if this is a frame associated with calling a signal handler.
 102
 103        Set by machine-dependent code.  On some machines, if
 104        the machine-dependent code fails to check for this, the backtrace
 105        will look relatively normal.  For example, on the i386
 106        #3  0x158728 in sighold ()
 107        On other machines (e.g. rs6000), the machine-dependent code better
 108        set this to prevent us from trying to print it like a normal frame.  */
 109     int signal_handler_caller;
 110
 111     /* For each register, address of where it was saved on entry to
 112        the frame, or zero if it was not saved on entry to this frame.
 113        This includes special registers such as pc and fp saved in
 114        special ways in the stack frame.  The SP_REGNUM is even more
 115        special, the address here is the sp for the previous frame, not
 116        the address where the sp was saved.  */
 117     /* Allocated by frame_saved_regs_zalloc () which is called /
 118        initialized by FRAME_INIT_SAVED_REGS(). */
 119     CORE_ADDR *saved_regs;      /*NUM_REGS + NUM_PSEUDO_REGS*/
 120
 121 #ifdef EXTRA_FRAME_INFO
 122     /* XXXX - deprecated */
 123     /* Anything extra for this structure that may have been defined
 124        in the machine dependent files. */
 125       EXTRA_FRAME_INFO
 126 #endif
 127
 128     /* Anything extra for this structure that may have been defined
 129        in the machine dependent files. */
 130     /* Allocated by frame_obstack_alloc () which is called /
 131        initialized by INIT_EXTRA_FRAME_INFO */
 132     struct frame_extra_info *extra_info;
 133
 134     /* If dwarf2 unwind frame informations is used, this structure holds all
 135        related unwind data.  */
 136     struct context *context;
 137
 138     /* See description above.  Return the register value for the
 139        previous frame.  */
 140     frame_register_unwind_ftype *register_unwind;
 141     void *register_unwind_cache;
 142
 143     /* Pointers to the next (down, inner, younger) and previous (up,
 144        outer, older) frame_info's in the frame cache.  */
 145     struct frame_info *next; /* down, inner, younger */
 146     int prev_p;
 147     struct frame_info *prev; /* up, outer, older */
 148   };
 149
 150 /* Values for the source flag to be used in print_frame_info_base(). */
 151 enum print_what
 152   {
 153     /* Print only the source line, like in stepi. */
 154     SRC_LINE = -1,
 155     /* Print only the location, i.e. level, address (sometimes)
 156        function, args, file, line, line num. */
 157     LOCATION,
 158     /* Print both of the above. */
 159     SRC_AND_LOC,
 160     /* Print location only, but always include the address. */
 161     LOC_AND_ADDRESS
 162   };
 163
 164 /* Allocate additional space for appendices to a struct frame_info.
 165    NOTE: Much of GDB's code works on the assumption that the allocated
 166    saved_regs[] array is the size specified below.  If you try to make
 167    that array smaller, GDB will happily walk off its end. */
 168
 169 #ifdef SIZEOF_FRAME_SAVED_REGS
 170 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 171 #endif
 172 #define SIZEOF_FRAME_SAVED_REGS \
 173         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 174
 175 extern void *frame_obstack_alloc (unsigned long size);
 176 extern void frame_saved_regs_zalloc (struct frame_info *);
 177
 178 /* Return the frame address from FI.  Except in the machine-dependent
 179    *FRAME* macros, a frame address has no defined meaning other than
 180    as a magic cookie which identifies a frame over calls to the
 181    inferior.  The only known exception is inferior.h
 182    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
 183    assume that a frame address contains enough information to
 184    reconstruct the frame; if you want more than just to identify the
 185    frame (e.g. be able to fetch variables relative to that frame),
 186    then save the whole struct frame_info (and the next struct
 187    frame_info, since the latter is used for fetching variables on some
 188    machines).  */
 189
 190 #define FRAME_FP(fi) ((fi)->frame)
 191
 192 /* Level of the frame: 0 for innermost, 1 for its caller, ...; or -1
 193    for an invalid frame.  */
 194
 195 extern int frame_relative_level (struct frame_info *fi);
 196
 197 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 198    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 199    is the outermost one and has no caller.
 200
 201    XXXX - both default and alternate frame_chain_valid functions are
 202    deprecated.  New code should use dummy frames and one of the
 203    generic functions. */
 204
 205 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 206 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 207 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
 208 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 209 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 210 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
 211
 212 /* The stack frame that the user has specified for commands to act on.
 213    Note that one cannot assume this is the address of valid data.  */
 214
 215 extern struct frame_info *selected_frame;
 216
 217 /* Level of the selected frame:
 218    0 for innermost, 1 for its caller, ...
 219    or -1 for frame specified by address with no defined level.  */
 220
 221 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
 222
 223 extern void flush_cached_frames (void);
 224
 225 extern void reinit_frame_cache (void);
 226
 227
 228 #ifdef FRAME_FIND_SAVED_REGS
 229 /* XXX - deprecated */
 230 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
 231 extern void get_frame_saved_regs (struct frame_info *,
 232                                   struct frame_saved_regs *);
 233 #endif
 234
 235 extern void set_current_frame (struct frame_info *);
 236
 237 extern struct frame_info *get_prev_frame (struct frame_info *);
 238
 239 extern struct frame_info *get_current_frame (void);
 240
 241 extern struct frame_info *get_next_frame (struct frame_info *);
 242
 243 extern struct block *get_frame_block (struct frame_info *,
 244                                       CORE_ADDR *addr_in_block);
 245
 246 extern struct block *get_current_block (CORE_ADDR *addr_in_block);
 247
 248 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 249
 250 extern struct symbol *get_frame_function (struct frame_info *);
 251
 252 extern CORE_ADDR get_frame_pc (struct frame_info *);
 253
 254 extern CORE_ADDR frame_address_in_block (struct frame_info *);
 255
 256 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 257
 258 extern struct block *block_for_pc (CORE_ADDR);
 259
 260 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 261
 262 extern int frameless_look_for_prologue (struct frame_info *);
 263
 264 extern void print_frame_args (struct symbol *, struct frame_info *,
 265                               int, struct ui_file *);
 266
 267 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 268
 269 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
 270                                         int source);
 271
 272 extern void print_stack_frame (struct frame_info *, int, int);
 273
 274 extern void print_only_stack_frame (struct frame_info *, int, int);
 275
 276 extern void show_stack_frame (struct frame_info *);
 277
 278 extern void select_frame (struct frame_info *);
 279
 280 /* Return an ID that can be used to re-find a frame.  */
 281
 282 struct frame_id
 283 {
 284   /* The frame's address.  This should be constant through out the
 285      lifetime of a frame.  */
 286   CORE_ADDR base;
 287   /* The frame's current PC.  While this changes, the function that
 288      the PC falls into, does not.  */
 289   CORE_ADDR pc;
 290 };
 291
 292 extern void get_frame_id (struct frame_info *fi, struct frame_id *id);
 293
 294 extern struct frame_info *frame_find_by_id (struct frame_id id);
 295
 296 extern void print_frame_info (struct frame_info *, int, int, int);
 297
 298 extern void show_frame_info (struct frame_info *, int, int, int);
 299
 300 extern struct frame_info *block_innermost_frame (struct block *);
 301
 302 extern struct frame_info *find_frame_addr_in_frame_chain (CORE_ADDR);
 303
 304 extern CORE_ADDR sigtramp_saved_pc (struct frame_info *);
 305
 306 /* NOTE: cagney/2002-09-13: There is no need for this function.
 307    Instead either of frame_unwind_signed_register() or
 308    frame_unwind_unsigned_register() can be used.  */
 309 extern CORE_ADDR deprecated_read_register_dummy (CORE_ADDR pc,
 310                                                  CORE_ADDR fp, int);
 311 extern void generic_push_dummy_frame (void);
 312 extern void generic_pop_current_frame (void (*)(struct frame_info *));
 313 extern void generic_pop_dummy_frame (void);
 314
 315 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
 316                                      CORE_ADDR sp, CORE_ADDR fp);
 317
 318 /* NOTE: cagney/2002-06-26: Targets should no longer use this
 319    function.  Instead, the contents of a dummy frames registers can be
 320    obtained by applying: frame_register_unwind to the dummy frame; or
 321    get_saved_register to the next outer frame.  */
 322
 323 extern char *deprecated_generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
 324
 325 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 326                                     int nargs, struct value **args,
 327                                     struct type *type, int gcc_p);
 328
 329 /* The function generic_get_saved_register() has been made obsolete.
 330    GET_SAVED_REGISTER now defaults to the recursive equivalent -
 331    generic_unwind_get_saved_register() - so there is no need to even
 332    set GET_SAVED_REGISTER.  Architectures that need to override the
 333    register unwind mechanism should modify frame->unwind().  */
 334 extern void deprecated_generic_get_saved_register (char *, int *, CORE_ADDR *,
 335                                                    struct frame_info *, int,
 336                                                    enum lval_type *);
 337
 338 extern void generic_unwind_get_saved_register (char *raw_buffer,
 339                                                int *optimized,
 340                                                CORE_ADDR * addrp,
 341                                                struct frame_info *frame,
 342                                                int regnum,
 343                                                enum lval_type *lval);
 344
 345 /* Unwind the stack frame so that the value of REGNUM, in the previous
 346    frame is returned.  If VALUEP is NULL, don't fetch/compute the
 347    value.  Instead just return the location of the value.  */
 348
 349 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 350                                    int *optimizedp, enum lval_type *lvalp,
 351                                    CORE_ADDR *addrp, int *realnump,
 352                                    void *valuep);
 353
 354 /* Return the value of the register in this FRAME.  Convenience
 355    function that is equivalent to frame_register_unwind
 356    (get_next_frame (FRAME), ...).  If VALUEP is NULL, don't
 357    fetch/compute the value.  */
 358
 359 extern void frame_register (struct frame_info *frame, int regnum,
 360                             int *optimizedp, enum lval_type *lvalp,
 361                             CORE_ADDR *addrp, int *realnump,
 362                             void *valuep);
 363
 364 /* Unwind FRAME so that the value of register REGNUM, in the previous
 365    frame is returned.  Simplified versions of frame_register_unwind.  */
 366 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
 367    be changed to return an indication that the read succeeded.  */
 368 extern void frame_unwind_signed_register (struct frame_info *frame,
 369                                           int regnum, LONGEST *val);
 370 extern void frame_unwind_unsigned_register (struct frame_info *frame,
 371                                             int regnum, ULONGEST *val);
 372
 373 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
 374
 375 extern void get_saved_register (char *raw_buffer, int *optimized,
 376                                 CORE_ADDR * addrp,
 377                                 struct frame_info *frame,
 378                                 int regnum, enum lval_type *lval);
 379
 380 /* Return the register as found on the FRAME.  Return zero if the
 381    register could not be found.  */
 382 extern int frame_register_read (struct frame_info *frame, int regnum,
 383                                 void *buf);
 384
 385 /* Return the value of register REGNUM that belongs to FRAME.  The
 386    value is obtained by unwinding the register from the next / more
 387    inner frame.  */
 388 /* NOTE: cagney/2002-09-13: Return void as one day these functions may
 389    be changed to return an indication that the read succeeded.  */
 390 extern void frame_read_signed_register (struct frame_info *frame,
 391                                         int regnum, LONGEST *val);
 392 extern void frame_read_unsigned_register (struct frame_info *frame,
 393                                           int regnum, ULONGEST *val);
 394
 395 /* Map between a frame register number and its name.  A frame register
 396    space is a superset of the cooked register space --- it also
 397    includes builtin registers.  */
 398
 399 extern int frame_map_name_to_regnum (const char *name, int strlen);
 400 extern const char *frame_map_regnum_to_name (int regnum);
 401
 402 /* From stack.c.  */
 403 extern void args_info (char *, int);
 404
 405 extern void locals_info (char *, int);
 406
 407 extern void (*selected_frame_level_changed_hook) (int);
 408
 409 extern void return_command (char *, int);
 410
 411 #endif /* !defined (FRAME_H)  */