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 /* Describe the saved registers of a frame.  */
  27
  28 #if defined (EXTRA_FRAME_INFO) || defined (FRAME_FIND_SAVED_REGS)
  29 /* XXXX - deprecated */
  30 struct frame_saved_regs
  31   {
  32     /* For each register R (except the SP), regs[R] is the address at
  33        which it was saved on entry to the frame, or zero if it was not
  34        saved on entry to this frame.  This includes special registers
  35        such as pc and fp saved in special ways in the stack frame.
  36
  37        regs[SP_REGNUM] is different.  It holds the actual SP, not the
  38        address at which it was saved.  */
  39
  40     CORE_ADDR regs[NUM_REGS];
  41   };
  42 #endif
  43
  44 /* We keep a cache of stack frames, each of which is a "struct
  45    frame_info".  The innermost one gets allocated (in
  46    wait_for_inferior) each time the inferior stops; current_frame
  47    points to it.  Additional frames get allocated (in
  48    get_prev_frame) as needed, and are chained through the next
  49    and prev fields.  Any time that the frame cache becomes invalid
  50    (most notably when we execute something, but also if we change how
  51    we interpret the frames (e.g. "set heuristic-fence-post" in
  52    mips-tdep.c, or anything which reads new symbols)), we should call
  53    reinit_frame_cache.  */
  54
  55 struct frame_info
  56   {
  57     /* Nominal address of the frame described.  See comments at FRAME_FP
  58        about what this means outside the *FRAME* macros; in the *FRAME*
  59        macros, it can mean whatever makes most sense for this machine.  */
  60     CORE_ADDR frame;
  61
  62     /* Address at which execution is occurring in this frame.
  63        For the innermost frame, it's the current pc.
  64        For other frames, it is a pc saved in the next frame.  */
  65     CORE_ADDR pc;
  66
  67     /* Level of this frame.  The inner-most (youngest) frame is at
  68        level 0.  As you move towards the outer-most (oldest) frame,
  69        the level increases.  This is a cached value.  It could just as
  70        easily be computed by counting back from the selected frame to
  71        the inner most frame.  */
  72     /* NOTE: cagney/2002-04-05: Perhaphs a level of ``-1'' should be
  73        reserved to indicate a bogus frame - one that has been created
  74        just to keep GDB happy (GDB always needs a frame).  For the
  75        moment leave this as speculation.  */
  76     int level;
  77
  78     /* Nonzero if this is a frame associated with calling a signal handler.
  79
  80        Set by machine-dependent code.  On some machines, if
  81        the machine-dependent code fails to check for this, the backtrace
  82        will look relatively normal.  For example, on the i386
  83        #3  0x158728 in sighold ()
  84        On other machines (e.g. rs6000), the machine-dependent code better
  85        set this to prevent us from trying to print it like a normal frame.  */
  86     int signal_handler_caller;
  87
  88     /* For each register, address of where it was saved on entry to
  89        the frame, or zero if it was not saved on entry to this frame.
  90        This includes special registers such as pc and fp saved in
  91        special ways in the stack frame.  The SP_REGNUM is even more
  92        special, the address here is the sp for the previous frame, not
  93        the address where the sp was saved.  */
  94     /* Allocated by frame_saved_regs_zalloc () which is called /
  95        initialized by FRAME_INIT_SAVED_REGS(). */
  96     CORE_ADDR *saved_regs;      /*NUM_REGS + NUM_PSEUDO_REGS*/
  97
  98 #ifdef EXTRA_FRAME_INFO
  99     /* XXXX - deprecated */
 100     /* Anything extra for this structure that may have been defined
 101        in the machine dependent files. */
 102       EXTRA_FRAME_INFO
 103 #endif
 104
 105     /* Anything extra for this structure that may have been defined
 106        in the machine dependent files. */
 107     /* Allocated by frame_obstack_alloc () which is called /
 108        initialized by INIT_EXTRA_FRAME_INFO */
 109     struct frame_extra_info *extra_info;
 110
 111     /* If dwarf2 unwind frame informations is used, this structure holds all
 112        related unwind data.  */
 113     struct unwind_contect *context;
 114
 115     /* Pointers to the next (down, inner) and previous (up, outer)
 116        frame_info's in the frame cache.  */
 117     struct frame_info *next; /* down, inner */
 118     struct frame_info *prev; /* up, outer */
 119   };
 120
 121 /* Values for the source flag to be used in print_frame_info_base(). */
 122 enum print_what
 123   {
 124     /* Print only the source line, like in stepi. */
 125     SRC_LINE = -1,
 126     /* Print only the location, i.e. level, address (sometimes)
 127        function, args, file, line, line num. */
 128     LOCATION,
 129     /* Print both of the above. */
 130     SRC_AND_LOC,
 131     /* Print location only, but always include the address. */
 132     LOC_AND_ADDRESS
 133   };
 134
 135 /* Allocate additional space for appendices to a struct frame_info.
 136    NOTE: Much of GDB's code works on the assumption that the allocated
 137    saved_regs[] array is the size specified below.  If you try to make
 138    that array smaller, GDB will happily walk off its end. */
 139
 140 #ifdef SIZEOF_FRAME_SAVED_REGS
 141 #error "SIZEOF_FRAME_SAVED_REGS can not be re-defined"
 142 #endif
 143 #define SIZEOF_FRAME_SAVED_REGS \
 144         (sizeof (CORE_ADDR) * (NUM_REGS+NUM_PSEUDO_REGS))
 145
 146 extern void *frame_obstack_alloc (unsigned long size);
 147 extern void frame_saved_regs_zalloc (struct frame_info *);
 148
 149 /* Return the frame address from FI.  Except in the machine-dependent
 150    *FRAME* macros, a frame address has no defined meaning other than
 151    as a magic cookie which identifies a frame over calls to the
 152    inferior.  The only known exception is inferior.h
 153    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
 154    assume that a frame address contains enough information to
 155    reconstruct the frame; if you want more than just to identify the
 156    frame (e.g. be able to fetch variables relative to that frame),
 157    then save the whole struct frame_info (and the next struct
 158    frame_info, since the latter is used for fetching variables on some
 159    machines).  */
 160
 161 #define FRAME_FP(fi) ((fi)->frame)
 162
 163 /* Level of the frame: 0 for innermost, 1 for its caller, ...; or -1
 164    for an invalid frame.  */
 165
 166 extern int frame_relative_level (struct frame_info *fi);
 167
 168 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 169    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 170    is the outermost one and has no caller.
 171
 172    XXXX - both default and alternate frame_chain_valid functions are
 173    deprecated.  New code should use dummy frames and one of the
 174    generic functions. */
 175
 176 extern int file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 177 extern int func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 178 extern int nonnull_frame_chain_valid (CORE_ADDR, struct frame_info *);
 179 extern int generic_file_frame_chain_valid (CORE_ADDR, struct frame_info *);
 180 extern int generic_func_frame_chain_valid (CORE_ADDR, struct frame_info *);
 181 extern void generic_save_dummy_frame_tos (CORE_ADDR sp);
 182
 183 /* The stack frame that the user has specified for commands to act on.
 184    Note that one cannot assume this is the address of valid data.  */
 185
 186 extern struct frame_info *selected_frame;
 187
 188 /* Level of the selected frame:
 189    0 for innermost, 1 for its caller, ...
 190    or -1 for frame specified by address with no defined level.  */
 191
 192 extern struct frame_info *create_new_frame (CORE_ADDR, CORE_ADDR);
 193
 194 extern void flush_cached_frames (void);
 195
 196 extern void reinit_frame_cache (void);
 197
 198
 199 #ifdef FRAME_FIND_SAVED_REGS
 200 /* XXX - deprecated */
 201 #define FRAME_INIT_SAVED_REGS(FI) get_frame_saved_regs (FI, NULL)
 202 extern void get_frame_saved_regs (struct frame_info *,
 203                                   struct frame_saved_regs *);
 204 #endif
 205
 206 extern void set_current_frame (struct frame_info *);
 207
 208 extern struct frame_info *get_prev_frame (struct frame_info *);
 209
 210 extern struct frame_info *get_current_frame (void);
 211
 212 extern struct frame_info *get_next_frame (struct frame_info *);
 213
 214 extern struct block *get_frame_block (struct frame_info *,
 215                                       CORE_ADDR *addr_in_block);
 216
 217 extern struct block *get_current_block (CORE_ADDR *addr_in_block);
 218
 219 extern struct block *get_selected_block (CORE_ADDR *addr_in_block);
 220
 221 extern struct symbol *get_frame_function (struct frame_info *);
 222
 223 extern CORE_ADDR get_frame_pc (struct frame_info *);
 224
 225 extern CORE_ADDR get_pc_function_start (CORE_ADDR);
 226
 227 extern struct block *block_for_pc (CORE_ADDR);
 228
 229 extern struct block *block_for_pc_sect (CORE_ADDR, asection *);
 230
 231 extern int frameless_look_for_prologue (struct frame_info *);
 232
 233 extern void print_frame_args (struct symbol *, struct frame_info *,
 234                               int, struct ui_file *);
 235
 236 extern struct frame_info *find_relative_frame (struct frame_info *, int *);
 237
 238 extern void show_and_print_stack_frame (struct frame_info *fi, int level,
 239                                         int source);
 240
 241 extern void print_stack_frame (struct frame_info *, int, int);
 242
 243 extern void print_only_stack_frame (struct frame_info *, int, int);
 244
 245 extern void show_stack_frame (struct frame_info *);
 246
 247 extern void select_frame (struct frame_info *, int);
 248
 249 extern void record_selected_frame (CORE_ADDR *, int *);
 250
 251 extern void select_and_print_frame (struct frame_info *, int);
 252
 253 extern void print_frame_info (struct frame_info *, int, int, int);
 254
 255 extern void show_frame_info (struct frame_info *, int, int, int);
 256
 257 extern CORE_ADDR find_saved_register (struct frame_info *, int);
 258
 259 extern struct frame_info *block_innermost_frame (struct block *);
 260
 261 extern struct frame_info *find_frame_addr_in_frame_chain (CORE_ADDR);
 262
 263 extern CORE_ADDR sigtramp_saved_pc (struct frame_info *);
 264
 265 extern CORE_ADDR generic_read_register_dummy (CORE_ADDR pc,
 266                                               CORE_ADDR fp, int);
 267 extern void generic_push_dummy_frame (void);
 268 extern void generic_pop_current_frame (void (*)(struct frame_info *));
 269 extern void generic_pop_dummy_frame (void);
 270
 271 extern int generic_pc_in_call_dummy (CORE_ADDR pc,
 272                                      CORE_ADDR sp, CORE_ADDR fp);
 273 extern char *generic_find_dummy_frame (CORE_ADDR pc, CORE_ADDR fp);
 274
 275 extern void generic_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun,
 276                                     int nargs, struct value **args,
 277                                     struct type *type, int gcc_p);
 278
 279 extern void generic_get_saved_register (char *, int *, CORE_ADDR *,
 280                                         struct frame_info *, int,
 281                                         enum lval_type *);
 282
 283 extern void generic_save_call_dummy_addr (CORE_ADDR lo, CORE_ADDR hi);
 284
 285 extern void get_saved_register (char *raw_buffer, int *optimized,
 286                                 CORE_ADDR * addrp,
 287                                 struct frame_info *frame,
 288                                 int regnum, enum lval_type *lval);
 289
 290 /* Return the register as found on the FRAME.  Return zero if the
 291    register could not be found.  */
 292 extern int frame_register_read (struct frame_info *frame, int regnum,
 293                                 void *buf);
 294
 295 #endif /* !defined (FRAME_H)  */