gdb/config/vax/tm-vax.h

   1 /* Definitions to make GDB run on a vax under 4.2bsd.
   2    Copyright 1986, 1987, 1989, 1991, 1993 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20
  21 #define TARGET_BYTE_ORDER LITTLE_ENDIAN
  22
  23 /* Offset from address of function to start of its code.
  24    Zero on most machines.  */
  25
  26 #define FUNCTION_START_OFFSET 2
  27
  28 /* Advance PC across any function entry prologue instructions
  29    to reach some "real" code.  */
  30
  31 #define SKIP_PROLOGUE(pc)       \
  32 { register int op = (unsigned char) read_memory_integer (pc, 1);  \
  33   if (op == 0x11) pc += 2;  /* skip brb */                        \
  34   if (op == 0x31) pc += 3;  /* skip brw */                        \
  35   if (op == 0xC2 &&                                               \
  36       ((unsigned char) read_memory_integer (pc+2, 1)) == 0x5E)    \
  37     pc += 3;  /* skip subl2 */                                    \
  38   if (op == 0x9E &&                                               \
  39       ((unsigned char) read_memory_integer (pc+1, 1)) == 0xAE &&  \
  40       ((unsigned char) read_memory_integer(pc+3, 1)) == 0x5E)     \
  41      pc += 4;  /* skip movab */                                   \
  42   if (op == 0x9E &&                                               \
  43       ((unsigned char) read_memory_integer (pc+1, 1)) == 0xCE &&  \
  44       ((unsigned char) read_memory_integer(pc+4, 1)) == 0x5E)     \
  45     pc += 5;  /* skip movab */                                    \
  46   if (op == 0x9E &&                                               \
  47       ((unsigned char) read_memory_integer (pc+1, 1)) == 0xEE &&  \
  48       ((unsigned char) read_memory_integer(pc+6, 1)) == 0x5E)     \
  49     pc += 7;  /* skip movab */                                    \
  50 }
  51
  52 /* Immediately after a function call, return the saved pc.
  53    Can't always go through the frames for this because on some machines
  54    the new frame is not set up until the new function executes
  55    some instructions.  */
  56
  57 #define SAVED_PC_AFTER_CALL(frame) FRAME_SAVED_PC(frame)
  58
  59 #define TARGET_UPAGES 14
  60 #define TARGET_NBPG 512
  61 #define STACK_END_ADDR (0x80000000 - (TARGET_UPAGES * TARGET_NBPG))
  62
  63 /* On the VAX, sigtramp is in the u area.  Can't check the exact
  64    addresses because for cross-debugging we don't have VAX include
  65    files around.  This should be close enough.  */
  66 #define SIGTRAMP_START(pc)      STACK_END_ADDR
  67 #define SIGTRAMP_END(pc)        0x80000000
  68
  69 /* Stack grows downward.  */
  70
  71 #define INNER_THAN <
  72
  73 /* Sequence of bytes for breakpoint instruction.  */
  74
  75 #define BREAKPOINT {3}
  76
  77 /* Amount PC must be decremented by after a breakpoint.
  78    This is often the number of bytes in BREAKPOINT
  79    but not always.  */
  80
  81 #define DECR_PC_AFTER_BREAK 0
  82
  83 /* Nonzero if instruction at PC is a return instruction.  */
  84
  85 #define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 1) == 04)
  86
  87 /* Return 1 if P points to an invalid floating point value.
  88    LEN is the length in bytes -- not relevant on the Vax.  */
  89
  90 #define INVALID_FLOAT(p, len) ((*(short *) p & 0xff80) == 0x8000)
  91
  92 /* Say how long (ordinary) registers are.  This is a piece of bogosity
  93    used in push_word and a few other places; REGISTER_RAW_SIZE is the
  94    real way to know how big a register is.  */
  95
  96 #define REGISTER_SIZE 4
  97
  98 /* Number of machine registers */
  99
 100 #define NUM_REGS 17
 101
 102 /* Initializer for an array of names of registers.
 103    There should be NUM_REGS strings in this initializer.  */
 104
 105 #define REGISTER_NAMES {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc", "ps"}
 106
 107 /* Register numbers of various important registers.
 108    Note that some of these values are "real" register numbers,
 109    and correspond to the general registers of the machine,
 110    and some are "phony" register numbers which are too large
 111    to be actual register numbers as far as the user is concerned
 112    but do serve to get the desired values when passed to read_register.  */
 113
 114 #define AP_REGNUM 12
 115 #define FP_REGNUM 13            /* Contains address of executing stack frame */
 116 #define SP_REGNUM 14            /* Contains address of top of stack */
 117 #define PC_REGNUM 15            /* Contains program counter */
 118 #define PS_REGNUM 16            /* Contains processor status */
 119
 120 /* Total amount of space needed to store our copies of the machine's
 121    register state, the array `registers'.  */
 122 #define REGISTER_BYTES (17*4)
 123
 124 /* Index within `registers' of the first byte of the space for
 125    register N.  */
 126
 127 #define REGISTER_BYTE(N) ((N) * 4)
 128
 129 /* Number of bytes of storage in the actual machine representation
 130    for register N.  On the vax, all regs are 4 bytes.  */
 131
 132 #define REGISTER_RAW_SIZE(N) 4
 133
 134 /* Number of bytes of storage in the program's representation
 135    for register N.  On the vax, all regs are 4 bytes.  */
 136
 137 #define REGISTER_VIRTUAL_SIZE(N) 4
 138
 139 /* Largest value REGISTER_RAW_SIZE can have.  */
 140
 141 #define MAX_REGISTER_RAW_SIZE 4
 142
 143 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 144
 145 #define MAX_REGISTER_VIRTUAL_SIZE 4
 146
 147 /* Return the GDB type object for the "standard" data type
 148    of data in register N.  */
 149
 150 #define REGISTER_VIRTUAL_TYPE(N) builtin_type_int
 151
 152 /* Store the address of the place in which to copy the structure the
 153    subroutine will return.  This is called from call_function. */
 154
 155 #define STORE_STRUCT_RETURN(ADDR, SP) \
 156   { write_register (1, (ADDR)); }
 157
 158 /* Extract from an array REGBUF containing the (raw) register state
 159    a function return value of type TYPE, and copy that, in virtual format,
 160    into VALBUF.  */
 161
 162 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 163   memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE))
 164
 165 /* Write into appropriate registers a function return value
 166    of type TYPE, given in virtual format.  */
 167
 168 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 169   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 170
 171 /* Extract from an array REGBUF containing the (raw) register state
 172    the address in which a function should return its structure value,
 173    as a CORE_ADDR (or an expression that can be used as one).  */
 174
 175 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 176
 177 \f
 178 /* Describe the pointer in each stack frame to the previous stack frame
 179    (its caller).  */
 180
 181 /* FRAME_CHAIN takes a frame's nominal address
 182    and produces the frame's chain-pointer. */
 183
 184 /* In the case of the Vax, the frame's nominal address is the FP value,
 185    and 12 bytes later comes the saved previous FP value as a 4-byte word.  */
 186
 187 #define FRAME_CHAIN(thisframe)  \
 188   (!inside_entry_file ((thisframe)->pc) ? \
 189    read_memory_integer ((thisframe)->frame + 12, 4) :\
 190    0)
 191
 192 /* Define other aspects of the stack frame.  */
 193
 194 /* A macro that tells us whether the function invocation represented
 195    by FI does not have a frame on the stack associated with it.  If it
 196    does not, FRAMELESS is set to 1, else 0.  */
 197 /* On the vax, all functions have frames.  */
 198 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS)  {(FRAMELESS) = 0;}
 199
 200 /* Saved Pc.  Get it from sigcontext if within sigtramp.  */
 201
 202 /* Offset to saved PC in sigcontext, from <sys/signal.h>.  */
 203 #define SIGCONTEXT_PC_OFFSET 12
 204
 205 #define FRAME_SAVED_PC(FRAME) \
 206   (((FRAME)->signal_handler_caller \
 207     ? sigtramp_saved_pc (FRAME) \
 208     : read_memory_integer ((FRAME)->frame + 16, 4)) \
 209    )
 210
 211 /* Cannot find the AP register value directly from the FP value.  Must
 212    find it saved in the frame called by this one, or in the AP
 213    register for the innermost frame.  However, there is no way to tell
 214    the difference between the innermost frame and a frame for which we
 215    just don't know the frame that it called (e.g. "info frame
 216    0x7ffec789").  For the sake of argument suppose that the stack is
 217    somewhat trashed (which is one reason that "info frame" exists).
 218    So return 0 (indicating we don't know the address of
 219    the arglist) if we don't know what frame this frame calls.  */
 220 #define FRAME_ARGS_ADDRESS_CORRECT(fi) \
 221  (((fi)->next                                  \
 222    ? read_memory_integer ((fi)->next->frame + 8, 4)   \
 223    : /* read_register (AP_REGNUM) */ 0))
 224
 225 /* In most of GDB, getting the args address is too important to
 226    just say "I don't know".  This is sometimes wrong for functions
 227    that aren't on top of the stack, but c'est la vie.  */
 228 #define FRAME_ARGS_ADDRESS(fi) \
 229  (((fi)->next                                  \
 230    ? read_memory_integer ((fi)->next->frame + 8, 4)   \
 231    : read_register (AP_REGNUM) /* 0 */))
 232
 233 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 234
 235 /* Return number of args passed to a frame.
 236    Can return -1, meaning no way to tell.  */
 237
 238 #define FRAME_NUM_ARGS(numargs, fi)  \
 239 { numargs = (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1)); }
 240
 241 /* Return number of bytes at start of arglist that are not really args.  */
 242
 243 #define FRAME_ARGS_SKIP 4
 244
 245 /* Put here the code to store, into a struct frame_saved_regs,
 246    the addresses of the saved registers of frame described by FRAME_INFO.
 247    This includes special registers such as pc and fp saved in special
 248    ways in the stack frame.  sp is even more special:
 249    the address we return for it IS the sp for the next frame.  */
 250
 251 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 252 { register int regnum;     \
 253   register int regmask = read_memory_integer ((frame_info)->frame+4, 4) >> 16; \
 254   register CORE_ADDR next_addr;     \
 255   memset (&frame_saved_regs, '\0', sizeof frame_saved_regs);     \
 256   next_addr = (frame_info)->frame + 16;     \
 257   /* Regmask's low bit is for register 0,     \
 258      which is the first one that would be pushed.  */     \
 259   for (regnum = 0; regnum < 12; regnum++, regmask >>= 1)  \
 260     (frame_saved_regs).regs[regnum] = (regmask & 1) ? (next_addr += 4) : 0;  \
 261   (frame_saved_regs).regs[SP_REGNUM] = next_addr + 4;  \
 262   if (read_memory_integer ((frame_info)->frame + 4, 4) & 0x20000000)   \
 263     (frame_saved_regs).regs[SP_REGNUM] += 4 + 4 * read_memory_integer (next_addr + 4, 4);  \
 264   (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 16;  \
 265   (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame + 12;  \
 266   (frame_saved_regs).regs[AP_REGNUM] = (frame_info)->frame + 8;  \
 267   (frame_saved_regs).regs[PS_REGNUM] = (frame_info)->frame + 4;  \
 268 }
 269 \f
 270 /* Things needed for making the inferior call functions.  */
 271
 272 /* Push an empty stack frame, to record the current PC, etc.  */
 273
 274 #define PUSH_DUMMY_FRAME \
 275 { register CORE_ADDR sp = read_register (SP_REGNUM);\
 276   register int regnum;                              \
 277   sp = push_word (sp, 0); /* arglist */             \
 278   for (regnum = 11; regnum >= 0; regnum--)          \
 279     sp = push_word (sp, read_register (regnum));    \
 280   sp = push_word (sp, read_register (PC_REGNUM));   \
 281   sp = push_word (sp, read_register (FP_REGNUM));   \
 282   sp = push_word (sp, read_register (AP_REGNUM));   \
 283   sp = push_word (sp, (read_register (PS_REGNUM) & 0xffef)   \
 284                       + 0x2fff0000);                \
 285   sp = push_word (sp, 0);                           \
 286   write_register (SP_REGNUM, sp);                   \
 287   write_register (FP_REGNUM, sp);                   \
 288   write_register (AP_REGNUM, sp + 17 * sizeof (int)); }
 289
 290 /* Discard from the stack the innermost frame, restoring all registers.  */
 291
 292 #define POP_FRAME  \
 293 { register CORE_ADDR fp = read_register (FP_REGNUM);             \
 294   register int regnum;                                           \
 295   register int regmask = read_memory_integer (fp + 4, 4);        \
 296   write_register (PS_REGNUM,                                     \
 297                   (regmask & 0xffff)                             \
 298                   | (read_register (PS_REGNUM) & 0xffff0000));   \
 299   write_register (PC_REGNUM, read_memory_integer (fp + 16, 4));  \
 300   write_register (FP_REGNUM, read_memory_integer (fp + 12, 4));  \
 301   write_register (AP_REGNUM, read_memory_integer (fp + 8, 4));   \
 302   fp += 16;                                                      \
 303   for (regnum = 0; regnum < 12; regnum++)                        \
 304     if (regmask & (0x10000 << regnum))                           \
 305       write_register (regnum, read_memory_integer (fp += 4, 4)); \
 306   fp = fp + 4 + ((regmask >> 30) & 3);                           \
 307   if (regmask & 0x20000000)                                      \
 308     { regnum = read_memory_integer (fp, 4);                      \
 309       fp += (regnum + 1) * 4; }                                  \
 310   write_register (SP_REGNUM, fp);                                \
 311   flush_cached_frames ();                                        \
 312 }
 313
 314 /* This sequence of words is the instructions
 315      calls #69, @#32323232
 316      bpt
 317    Note this is 8 bytes.  */
 318
 319 #define CALL_DUMMY {0x329f69fb, 0x03323232}
 320
 321 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 322
 323 #define CALL_DUMMY_BREAKPOINT_OFFSET 7
 324
 325 /* Insert the specified number of args and function address
 326    into a call sequence of the above form stored at DUMMYNAME.  */
 327
 328 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)   \
 329 { *((char *) dummyname + 1) = nargs;            \
 330   *(int *)((char *) dummyname + 3) = fun; }
 331
 332 /* If vax pcc says CHAR or SHORT, it provides the correct address.  */
 333
 334 #define BELIEVE_PCC_PROMOTION 1