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) and previous (up, outer)
 144        frame_info's in the frame cache.  */
 145     struct frame_info *next; /* down, inner */
 146     struct frame_info *prev; /* up, outer */
 147   };
 148
 149 /* Values for the source flag to be used in print_frame_info_base(). */
 150 enum print_what
 151   {
 152     /* Print only the source line, like in stepi. */
 153     SRC_LINE = -1,
 154     /* Print only the location, i.e. level, address (sometimes)
 155        function, args, file, line, line num. */
 156     LOCATION,
 157     /* Print both of the above. */
 158     SRC_AND_LOC,
 159     /* Print location only, but always include the address. */
 160     LOC_AND_ADDRESS
 161   };
 162
 163 /* Allocate additional space for appendices to a struct frame_info.
 164    NOTE: Much of GDB's code works on the assumption that the allocated
 165    saved_regs[] array is the size specified below.  If you try to make
 166    that array smaller, GDB will happily walk off its end. */
 167
 168 #ifdef SIZEOF_FRAME_SAVED_REGS
 169 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 170 #endif
 171 #define SIZEOF_FRAME_SAVED_REGS \
 172         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 173
 174 extern void *frame_obstack_alloc (unsigned long size);
 175 extern void frame_saved_regs_zalloc (struct frame_info *);
 176
 177 /* Return the frame address from FI.  Except in the machine-dependent
 178    *FRAME* macros, a frame address has no defined meaning other than
 179    as a magic cookie which identifies a frame over calls to the
 180    inferior.  The only known exception is inferior.h
 181    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
 182    assume that a frame address contains enough information to
 183    reconstruct the frame; if you want more than just to identify the
 184    frame (e.g. be able to fetch variables relative to that frame),
 185    then save the whole struct frame_info (and the next struct
 186    frame_info, since the latter is used for fetching variables on some
 187    machines).  */
 188
 189 #define FRAME_FP(fi) ((fi)->frame)
 190
 191 /* Level of the frame: 0 for innermost, 1 for its caller, ...; or -1
 192    for an invalid frame.  */
 193
 194 extern int frame_relative_level (struct frame_info *fi);
 195
 196 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 197    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 198    is the outermost one and has no caller.
 199
 200    XXXX - both default and alternate frame_chain_valid functions are
 201    deprecated.  New code should use dummy frames and one of the
 202    generic functions. */
 203
 204 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 205 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 206 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
 207 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 208 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 209 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
 210
 211 /* The stack frame that the user has specified for commands to act on.
 212    Note that one cannot assume this is the address of valid data.  */
 213
 214 extern struct frame_info *selected_frame;
 215
 216 /* Level of the selected frame:
 217    0 for innermost, 1 for its caller, ...
 218    or -1 for frame specified by address with no defined level.  */
 219
 220 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
 221
 222 extern void flush_cached_frames (void);
 223
 224 extern void reinit_frame_cache (void);
 225
 226
 227 #ifdef FRAME_FIND_SAVED_REGS
 228 /* XXX - deprecated */
 229 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
 230 extern void get_frame_saved_regs (struct frame_info *,
 231                                   struct frame_saved_regs *);
 232 #endif
 233
 234 extern void set_current_frame (struct frame_info *);
 235
 236 extern struct frame_info *get_prev_frame (struct frame_info *);
 237
 238 extern struct frame_info *get_current_frame (void);
 239
 240 extern struct frame_info *get_next_frame (struct frame_info *);
 241
 242 extern struct block *get_frame_block (struct frame_info *,
 243                                       CORE_ADDR *addr_in_block);
 244
 245 extern struct block *get_current_block (CORE_ADDR *addr_in_block);
 246
 247 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 248
 249 extern struct symbol *get_frame_function (struct frame_info *);
 250
 251 extern CORE_ADDR get_frame_pc (struct frame_info *);
 252
 253 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 254
 255 extern struct block *block_for_pc (CORE_ADDR);
 256
 257 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 258
 259 extern int frameless_look_for_prologue (struct frame_info *);
 260
 261 extern void print_frame_args (struct symbol *, struct frame_info *,
 262                               int, struct ui_file *);
 263
 264 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 265
 266 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
 267                                         int source);
 268
 269 extern void print_stack_frame (struct frame_info *, int, int);
 270
 271 extern void print_only_stack_frame (struct frame_info *, int, int);
 272
 273 extern void show_stack_frame (struct frame_info *);
 274
 275 extern void select_frame (struct frame_info *);
 276
 277 /* Return an ID that can be used to re-find a frame.  */
 278
 279 struct frame_id
 280 {
 281   /* The frame's address.  This should be constant through out the
 282      lifetime of a frame.  */
 283   CORE_ADDR base;
 284   /* The frame's current PC.  While this changes, the function that
 285      the PC falls into, does not.  */
 286   CORE_ADDR pc;
 287 };
 288
 289 extern void get_frame_id (struct frame_info *fi, struct frame_id *id);
 290
 291 extern struct frame_info *frame_find_by_id (struct frame_id id);
 292
 293 extern void print_frame_info (struct frame_info *, int, int, int);
 294
 295 extern void show_frame_info (struct frame_info *, int, int, int);
 296
 297 extern CORE_ADDR find_saved_register (struct frame_info *, int);
 298
 299 extern struct frame_info *block_innermost_frame (struct block *);
 300
 301 extern struct frame_info *find_frame_addr_in_frame_chain (CORE_ADDR);
 302
 303 extern CORE_ADDR sigtramp_saved_pc (struct frame_info *);
 304
 305 extern CORE_ADDR generic_read_register_dummy (CORE_ADDR pc,
 306                                               CORE_ADDR fp, int);
 307 extern void generic_push_dummy_frame (void);
 308 extern void generic_pop_current_frame (void (*)(struct frame_info *));
 309 extern void generic_pop_dummy_frame (void);
 310
 311 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
 312                                      CORE_ADDR sp, CORE_ADDR fp);
 313 extern char *generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
 314
 315 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 316                                     int nargs, struct value **args,
 317                                     struct type *type, int gcc_p);
 318
 319 extern void generic_get_saved_register (char *, int *, CORE_ADDR *,
 320                                         struct frame_info *, int,
 321                                         enum lval_type *);
 322
 323 extern void generic_unwind_get_saved_register (char *raw_buffer,
 324                                                int *optimized,
 325                                                CORE_ADDR * addrp,
 326                                                struct frame_info *frame,
 327                                                int regnum,
 328                                                enum lval_type *lval);
 329
 330 /* Unwind the stack frame so that the value of REGNUM, in the previous
 331    frame is returned.  If VALUEP is NULL, don't fetch/compute the
 332    value.  Instead just return the location of the value.  */
 333
 334 extern void frame_register_unwind (struct frame_info *frame, int regnum,
 335                                    int *optimizedp, enum lval_type *lvalp,
 336                                    CORE_ADDR *addrp, int *realnump,
 337                                    void *valuep);
 338
 339 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
 340
 341 extern void get_saved_register (char *raw_buffer, int *optimized,
 342                                 CORE_ADDR * addrp,
 343                                 struct frame_info *frame,
 344                                 int regnum, enum lval_type *lval);
 345
 346 /* Return the register as found on the FRAME.  Return zero if the
 347    register could not be found.  */
 348 extern int frame_register_read (struct frame_info *frame, int regnum,
 349                                 void *buf);
 350
 351 #endif /* !defined (FRAME_H)  */