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