gdb/config/i386/tm-i386.h

   1 /* Macro definitions for GDB on an Intel i[345]86.
   2    Copyright (C) 1995 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 #ifndef TM_I386_H
  21 #define TM_I386_H 1
  22
  23 #ifdef __STDC__         /* Forward decl's for prototypes */
  24 struct frame_info;
  25 struct frame_saved_regs;
  26 struct type;
  27 #endif
  28
  29 #define TARGET_BYTE_ORDER LITTLE_ENDIAN
  30
  31 /* Used for example in valprint.c:print_floating() to enable checking
  32    for NaN's */
  33
  34 #define IEEE_FLOAT
  35
  36 /* Number of traps that happen between exec'ing the shell to run an
  37    inferior, and when we finally get to the inferior code.  This is 2
  38    on most implementations. */
  39
  40 #define START_INFERIOR_TRAPS_EXPECTED 2
  41
  42 /* Offset from address of function to start of its code.
  43    Zero on most machines.  */
  44
  45 #define FUNCTION_START_OFFSET 0
  46
  47 /* Advance PC across any function entry prologue instructions to reach some
  48    "real" code.  */
  49
  50 #define SKIP_PROLOGUE(frompc)   {(frompc) = i386_skip_prologue((frompc));}
  51
  52 extern int i386_skip_prologue PARAMS ((int));
  53
  54 /* Immediately after a function call, return the saved pc.  Can't always go
  55    through the frames for this because on some machines the new frame is not
  56    set up until the new function executes some instructions.  */
  57
  58 #define SAVED_PC_AFTER_CALL(frame) (read_memory_integer (read_register (SP_REGNUM), 4))
  59
  60 /* Stack grows downward.  */
  61
  62 #define INNER_THAN <
  63
  64 /* Sequence of bytes for breakpoint instruction.  */
  65
  66 #define BREAKPOINT {0xcc}
  67
  68 /* Amount PC must be decremented by after a breakpoint.  This is often the
  69    number of bytes in BREAKPOINT but not always. */
  70
  71 #define DECR_PC_AFTER_BREAK 1
  72
  73 /* Nonzero if instruction at PC is a return instruction.  */
  74
  75 #define ABOUT_TO_RETURN(pc) (read_memory_integer ((pc), 1) == 0xc3)
  76
  77 /* Say how long (ordinary) registers are.  This is a piece of bogosity
  78    used in push_word and a few other places; REGISTER_RAW_SIZE is the
  79    real way to know how big a register is.  */
  80
  81 #define REGISTER_SIZE 4
  82
  83 /* Number of machine registers */
  84
  85 #define NUM_FREGS 0 /*8*/               /* Number of FP regs */
  86 #define NUM_REGS (16 + NUM_FREGS)       /* Basic i*86 regs + FP regs */
  87
  88 /* Initializer for an array of names of registers.  There should be at least
  89    NUM_REGS strings in this initializer.  Any excess ones are simply ignored.
  90    The order of the first 8 registers must match the compiler's numbering
  91    scheme (which is the same as the 386 scheme) and also regmap in the various
  92    *-nat.c files. */
  93
  94 #define REGISTER_NAMES { "eax",   "ecx",    "edx",   "ebx", \
  95                          "esp",   "ebp",    "esi",   "edi", \
  96                          "eip",   "eflags", "cs",    "ss", \
  97                          "ds",    "es",     "fs",    "gs", \
  98                          "st0",   "st1",    "st2",   "st3", \
  99                          "st4",   "st5",    "st6",   "st7", \
 100                          }
 101
 102 /* Register numbers of various important registers.
 103    Note that some of these values are "real" register numbers,
 104    and correspond to the general registers of the machine,
 105    and some are "phony" register numbers which are too large
 106    to be actual register numbers as far as the user is concerned
 107    but do serve to get the desired values when passed to read_register.  */
 108
 109 #define FP_REGNUM 5     /* (ebp) Contains address of executing stack frame */
 110 #define SP_REGNUM 4     /* (usp) Contains address of top of stack */
 111 #define PC_REGNUM 8     /* (eip) Contains program counter */
 112 #define PS_REGNUM 9     /* (ps)  Contains processor status */
 113
 114 #define FP0_REGNUM 16   /* (st0) 387 register */
 115 #define FPC_REGNUM 25   /* 80387 control register */
 116
 117 /* Total amount of space needed to store our copies of the machine's register
 118    state, the array `registers'.  Default is 16 i*86 registers and 8 floating
 119    point registers. */
 120
 121 #define REGISTER_BYTES (16*4 + 8*10)
 122
 123 /* Index within `registers' of the first byte of the space for register N. */
 124
 125 #define REGISTER_BYTE(N) \
 126   (((N) < FP0_REGNUM) ? ((N) * 4) : ((((N) - FP0_REGNUM) * 10) + 64))
 127
 128 /* Number of bytes of storage in the actual machine representation for
 129    register N.  All registers are 4 bytes, except 387 st(0) - st(7),
 130    which are 80 bits each. */
 131
 132 #define REGISTER_RAW_SIZE(N) (((N) < FP0_REGNUM) ? 4 : 10)
 133
 134 /* Largest value REGISTER_RAW_SIZE can have.  */
 135
 136 #define MAX_REGISTER_RAW_SIZE 10
 137
 138 /* Number of bytes of storage in the program's representation
 139    for register N. */
 140
 141 #define REGISTER_VIRTUAL_SIZE(N) (((N) < FP0_REGNUM) ? 4 : 8)
 142
 143 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 144
 145 #define MAX_REGISTER_VIRTUAL_SIZE 8
 146
 147 /* Return the GDB type object for the "standard" data type of data in
 148    register N.  Perhaps si and di should go here, but potentially they
 149    could be used for things other than address.  */
 150
 151 #define REGISTER_VIRTUAL_TYPE(N) \
 152   (((N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM) \
 153    ? lookup_pointer_type (builtin_type_void) \
 154    : (((N) < FP0_REGNUM) \
 155       ? builtin_type_int \
 156       : builtin_type_double))
 157
 158 /* Store the address of the place in which to copy the structure the
 159    subroutine will return.  This is called from call_function. */
 160
 161 #define STORE_STRUCT_RETURN(ADDR, SP) \
 162   { (SP) -= sizeof (ADDR);              \
 163     write_memory ((SP), (char *) &(ADDR), sizeof (ADDR)); }
 164
 165 /* Extract from an array REGBUF containing the (raw) register state
 166    a function return value of type TYPE, and copy that, in virtual format,
 167    into VALBUF.  */
 168
 169 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 170    i386_extract_return_value ((TYPE),(REGBUF),(VALBUF))
 171
 172 extern void i386_extract_return_value PARAMS ((struct type *, char [], char *));
 173
 174 /* Write into appropriate registers a function return value of type TYPE, given
 175    in virtual format.  */
 176
 177 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 178   {                                                                          \
 179     if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)                                   \
 180       write_register_bytes (REGISTER_BYTE (FP0_REGNUM), (VALBUF),            \
 181                             TYPE_LENGTH (TYPE));                             \
 182     else                                                                     \
 183       write_register_bytes (0, (VALBUF), TYPE_LENGTH (TYPE));                \
 184   }
 185
 186 /* Extract from an array REGBUF containing the (raw) register state the address
 187    in which a function should return its structure value, as a CORE_ADDR (or an
 188    expression that can be used as one).  */
 189
 190 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 191
 192 /* The following redefines make backtracing through sigtramp work.
 193    They manufacture a fake sigtramp frame and obtain the saved pc in sigtramp
 194    from the sigcontext structure which is pushed by the kernel on the
 195    user stack, along with a pointer to it.  */
 196
 197 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 198    chain-pointer.
 199    In the case of the i386, the frame's nominal address
 200    is the address of a 4-byte word containing the calling frame's address.  */
 201
 202 #define FRAME_CHAIN(thisframe)  \
 203   ((thisframe)->signal_handler_caller \
 204    ? (thisframe)->frame \
 205    : (!inside_entry_file ((thisframe)->pc) \
 206       ? read_memory_integer ((thisframe)->frame, 4) \
 207       : 0))
 208
 209 /* A macro that tells us whether the function invocation represented
 210    by FI does not have a frame on the stack associated with it.  If it
 211    does not, FRAMELESS is set to 1, else 0.  */
 212
 213 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
 214   do { \
 215     if ((FI)->signal_handler_caller) \
 216       (FRAMELESS) = 0; \
 217     else \
 218       (FRAMELESS) = frameless_look_for_prologue(FI); \
 219   } while (0)
 220
 221 /* Saved Pc.  Get it from sigcontext if within sigtramp.  */
 222
 223 #define FRAME_SAVED_PC(FRAME) \
 224   (((FRAME)->signal_handler_caller \
 225     ? sigtramp_saved_pc (FRAME) \
 226     : read_memory_integer ((FRAME)->frame + 4, 4)) \
 227    )
 228
 229 extern CORE_ADDR sigtramp_saved_pc PARAMS ((struct frame_info *));
 230
 231 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
 232
 233 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 234
 235 /* Return number of args passed to a frame.  Can return -1, meaning no way
 236    to tell, which is typical now that the C compiler delays popping them.  */
 237
 238 #define FRAME_NUM_ARGS(numargs, fi) (numargs) = i386_frame_num_args(fi)
 239
 240 extern int i386_frame_num_args PARAMS ((struct frame_info *));
 241
 242 /* Return number of bytes at start of arglist that are not really args.  */
 243
 244 #define FRAME_ARGS_SKIP 8
 245
 246 /* Put here the code to store, into a struct frame_saved_regs,
 247    the addresses of the saved registers of frame described by FRAME_INFO.
 248    This includes special registers such as pc and fp saved in special
 249    ways in the stack frame.  sp is even more special:
 250    the address we return for it IS the sp for the next frame.  */
 251
 252 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 253 { i386_frame_find_saved_regs ((frame_info), &(frame_saved_regs)); }
 254
 255 extern void i386_frame_find_saved_regs PARAMS ((struct frame_info *,
 256                                                 struct frame_saved_regs *));
 257
 258 \f
 259 /* Things needed for making the inferior call functions.  */
 260
 261 /* Push an empty stack frame, to record the current PC, etc.  */
 262
 263 #define PUSH_DUMMY_FRAME { i386_push_dummy_frame (); }
 264
 265 extern void i386_push_dummy_frame PARAMS ((void));
 266
 267 /* Discard from the stack the innermost frame, restoring all registers.  */
 268
 269 #define POP_FRAME  { i386_pop_frame (); }
 270
 271 extern void i386_pop_frame PARAMS ((void));
 272
 273 \f
 274 /* this is
 275  *   call 11223344 (32 bit relative)
 276  *   int3
 277  */
 278
 279 #define CALL_DUMMY { 0x223344e8, 0xcc11 }
 280
 281 #define CALL_DUMMY_LENGTH 8
 282
 283 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 284
 285 #define CALL_DUMMY_BREAKPOINT_OFFSET 5
 286
 287 /* Insert the specified number of args and function address
 288    into a call sequence of the above form stored at DUMMYNAME.  */
 289
 290 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)   \
 291 { \
 292         int from, to, delta, loc; \
 293         loc = (int)(read_register (SP_REGNUM) - CALL_DUMMY_LENGTH); \
 294         from = loc + 5; \
 295         to = (int)(fun); \
 296         delta = to - from; \
 297         *((char *)(dummyname) + 1) = (delta & 0xff); \
 298         *((char *)(dummyname) + 2) = ((delta >> 8) & 0xff); \
 299         *((char *)(dummyname) + 3) = ((delta >> 16) & 0xff); \
 300         *((char *)(dummyname) + 4) = ((delta >> 24) & 0xff); \
 301 }
 302
 303 extern void print_387_control_word PARAMS ((unsigned int));
 304 extern void print_387_status_word PARAMS ((unsigned int));
 305
 306 /* Offset from SP to first arg on stack at first instruction of a function */
 307
 308 #define SP_ARG0 (1 * 4)
 309
 310 #endif /* ifndef TM_I386_H */