gdb/frame.h

   1 /* Definitions for dealing with stack frames, for GDB, the GNU debugger.
   2    Copyright 1986, 1989, 1991, 1992 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #if !defined (FRAME_H)
  21 #define FRAME_H 1
  22
  23 /* A FRAME identifies a specific stack frame.  It is not constant over
  24    calls to the inferior (frame addresses are, see below).
  25
  26    This is implemented as a "struct frame_info *".  This file and
  27    blockframe.c are the only places which are allowed to use the
  28    equivalence between FRAME and struct frame_info *.  Exception:
  29    Prototypes in other files use "struct frame_info *" because this
  30    file might not be included.
  31
  32    The distinction between a FRAME and a "struct frame_info *" is made
  33    with the idea of maybe someday changing a FRAME to be something else,
  34    but seems to me that a "struct frame_info *" is fully general (since
  35    any necessarily fields can be added; changing the meaning of existing
  36    fields is not helped by the FRAME distinction), and this distinction
  37    merely creates unnecessary hair.  -kingdon, 18 May 93.  */
  38 typedef struct frame_info *FRAME;
  39
  40 /* Convert from a "struct frame_info *" into a FRAME.  */
  41 #define FRAME_INFO_ID(f)        (f)
  42
  43 /* Convert from a FRAME into a "struct frame_info *".  */
  44 extern struct frame_info *
  45 get_frame_info PARAMS ((FRAME));
  46
  47 /* Type of the address of a frame.  It is widely assumed (at least in
  48    prototypes in headers which might not include this header) that
  49    this is the same as CORE_ADDR, and no one can think of a case in
  50    which it wouldn't be, so it might be best to remove this typedef.  */
  51 typedef CORE_ADDR       FRAME_ADDR;
  52
  53 /* Convert from a FRAME into a frame address.  Except in the
  54    machine-dependent *FRAME* macros, a frame address has no defined
  55    meaning other than as a magic cookie which identifies a frame over
  56    calls to the inferior.  The only known exception is inferior.h
  57    (PC_IN_CALL_DUMMY) [ON_STACK]; see comments there.  You cannot
  58    assume that a frame address contains enough information to
  59    reconstruct the frame; if you want more than just to identify the
  60    frame (e.g. be able to fetch variables relative to that frame),
  61    then save the whole struct frame_info (and the next struct
  62    frame_info, since the latter is used for fetching variables on some
  63    machines).  */
  64
  65 #define FRAME_FP(fr)    ((fr)->frame)
  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_info) 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     FRAME_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     /* Nonzero if this is a frame associated with calling a signal handler.
  91
  92        Set by machine-dependent code.  On some machines, if
  93        the machine-dependent code fails to check for this, the backtrace
  94        will look relatively normal.  For example, on the i386
  95          #3  0x158728 in sighold ()
  96        On other machines (e.g. rs6000), the machine-dependent code better
  97        set this to prevent us from trying to print it like a normal frame.  */
  98     int signal_handler_caller;
  99
 100     /* Anything extra for this structure that may have been defined
 101        in the machine dependent files. */
 102 #ifdef EXTRA_FRAME_INFO
 103     EXTRA_FRAME_INFO
 104 #endif
 105
 106     /* We should probably also store a "struct frame_saved_regs" here.
 107        This is already done by some machines (e.g. config/m88k/tm-m88k.h)
 108        but there is no reason it couldn't be general.  */
 109
 110     /* Pointers to the next and previous frame_info's in the frame cache.  */
 111     FRAME next, prev;
 112   };
 113
 114 /* Describe the saved registers of a frame.  */
 115
 116 struct frame_saved_regs
 117   {
 118
 119     /* For each register, address of where it was saved on entry to
 120        the frame, or zero if it was not saved on entry to this frame.
 121        This includes special registers such as pc and fp saved in
 122        special ways in the stack frame.  The SP_REGNUM is even more
 123        special, the address here is the sp for the next frame, not the
 124        address where the sp was saved.  */
 125
 126     CORE_ADDR regs[NUM_REGS];
 127   };
 128
 129 /* Define a default FRAME_CHAIN_VALID, in the form that is suitable for most
 130    targets.  If FRAME_CHAIN_VALID returns zero it means that the given frame
 131    is the outermost one and has no caller.
 132
 133    If a particular target needs a different definition, then it can override
 134    the definition here by providing one in the tm file. */
 135
 136 #if !defined (FRAME_CHAIN_VALID)
 137
 138 #if defined (FRAME_CHAIN_VALID_ALTERNATE)
 139
 140 /* Use the alternate method of avoiding running up off the end of the frame
 141    chain or following frames back into the startup code.  See the comments
 142    in objfiles.h. */
 143
 144 #define FRAME_CHAIN_VALID(chain, thisframe)     \
 145   ((chain) != 0                                 \
 146    && !inside_main_func ((thisframe) -> pc)     \
 147    && !inside_entry_func ((thisframe) -> pc))
 148
 149 #else
 150
 151 #define FRAME_CHAIN_VALID(chain, thisframe)     \
 152   ((chain) != 0                                 \
 153    && !inside_entry_file (FRAME_SAVED_PC (thisframe)))
 154
 155 #endif  /* FRAME_CHAIN_VALID_ALTERNATE */
 156
 157 #endif  /* FRAME_CHAIN_VALID */
 158
 159 /* If we encounter a request to use base register addressing of variables
 160    on a machine for which gdb has not been configured to support such
 161    access, report the failure to support this access mode. */
 162
 163 /* FIXME: Code using this should be using get_saved_register, and a
 164    basereg number should just be an ordinary register number.  There
 165    is no reason for this to be machine-specific.  */
 166
 167 #if !defined (FRAME_GET_BASEREG_VALUE)
 168
 169 #define FRAME_GET_BASEREG_VALUE(frame, regno) \
 170   (error ("Missing valid method for finding contents of base register."),0)
 171
 172 #endif
 173
 174 /* The stack frame that the user has specified for commands to act on.
 175    Note that one cannot assume this is the address of valid data.  */
 176
 177 extern FRAME selected_frame;
 178
 179 /* Level of the selected frame:
 180    0 for innermost, 1 for its caller, ...
 181    or -1 for frame specified by address with no defined level.  */
 182
 183 extern int selected_frame_level;
 184
 185 extern struct frame_info *
 186 get_prev_frame_info PARAMS ((FRAME));
 187
 188 extern FRAME
 189 create_new_frame PARAMS ((FRAME_ADDR, CORE_ADDR));
 190
 191 extern void
 192 flush_cached_frames PARAMS ((void));
 193
 194 extern void
 195 reinit_frame_cache PARAMS ((void));
 196
 197 extern void
 198 get_frame_saved_regs PARAMS ((struct frame_info *, struct frame_saved_regs *));
 199
 200 extern void
 201 set_current_frame PARAMS ((FRAME));
 202
 203 extern FRAME
 204 get_prev_frame PARAMS ((FRAME));
 205
 206 extern FRAME
 207 get_current_frame PARAMS ((void));
 208
 209 extern FRAME
 210 get_next_frame PARAMS ((FRAME));
 211
 212 extern struct block *
 213 get_frame_block PARAMS ((FRAME));
 214
 215 extern struct block *
 216 get_current_block PARAMS ((void));
 217
 218 extern struct block *
 219 get_selected_block PARAMS ((void));
 220
 221 extern struct symbol *
 222 get_frame_function PARAMS ((FRAME));
 223
 224 extern CORE_ADDR
 225 get_frame_pc PARAMS ((FRAME));
 226
 227 extern CORE_ADDR
 228 get_pc_function_start PARAMS ((CORE_ADDR));
 229
 230 extern struct block * block_for_pc PARAMS ((CORE_ADDR));
 231
 232 extern int frameless_look_for_prologue PARAMS ((FRAME));
 233
 234 extern void print_frame_args PARAMS ((struct symbol *, struct frame_info *,
 235                                       int, FILE *));
 236
 237 extern FRAME find_relative_frame PARAMS ((FRAME, int*));
 238
 239 extern void print_stack_frame PARAMS ((FRAME, int, int));
 240
 241 extern void select_frame PARAMS ((FRAME, int));
 242
 243 extern void record_selected_frame PARAMS ((FRAME_ADDR *, int *));
 244
 245 extern void print_frame_info PARAMS ((struct frame_info *, int, int, int));
 246
 247 extern CORE_ADDR find_saved_register PARAMS ((FRAME, int));
 248
 249 extern FRAME block_innermost_frame PARAMS ((struct block *));
 250
 251 extern CORE_ADDR sigtramp_saved_pc PARAMS ((FRAME));
 252
 253 #endif /* !defined (FRAME_H)  */