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., 675 Mass Ave, Cambridge, MA 02139, 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  STACK_END_ADDR
  67 #define SIGTRAMP_END    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.  */
  93
  94 #define REGISTER_TYPE long
  95
  96 /* Number of machine registers */
  97
  98 #define NUM_REGS 17
  99
 100 /* Initializer for an array of names of registers.
 101    There should be NUM_REGS strings in this initializer.  */
 102
 103 #define REGISTER_NAMES {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc", "ps"}
 104
 105 /* Register numbers of various important registers.
 106    Note that some of these values are "real" register numbers,
 107    and correspond to the general registers of the machine,
 108    and some are "phony" register numbers which are too large
 109    to be actual register numbers as far as the user is concerned
 110    but do serve to get the desired values when passed to read_register.  */
 111
 112 #define AP_REGNUM 12
 113 #define FP_REGNUM 13            /* Contains address of executing stack frame */
 114 #define SP_REGNUM 14            /* Contains address of top of stack */
 115 #define PC_REGNUM 15            /* Contains program counter */
 116 #define PS_REGNUM 16            /* Contains processor status */
 117
 118 /* Total amount of space needed to store our copies of the machine's
 119    register state, the array `registers'.  */
 120 #define REGISTER_BYTES (17*4)
 121
 122 /* Index within `registers' of the first byte of the space for
 123    register N.  */
 124
 125 #define REGISTER_BYTE(N) ((N) * 4)
 126
 127 /* Number of bytes of storage in the actual machine representation
 128    for register N.  On the vax, all regs are 4 bytes.  */
 129
 130 #define REGISTER_RAW_SIZE(N) 4
 131
 132 /* Number of bytes of storage in the program's representation
 133    for register N.  On the vax, all regs are 4 bytes.  */
 134
 135 #define REGISTER_VIRTUAL_SIZE(N) 4
 136
 137 /* Largest value REGISTER_RAW_SIZE can have.  */
 138
 139 #define MAX_REGISTER_RAW_SIZE 4
 140
 141 /* Largest value REGISTER_VIRTUAL_SIZE can have.  */
 142
 143 #define MAX_REGISTER_VIRTUAL_SIZE 4
 144
 145 /* Nonzero if register N requires conversion
 146    from raw format to virtual format.  */
 147
 148 #define REGISTER_CONVERTIBLE(N) 0
 149
 150 /* Convert data from raw format for register REGNUM
 151    to virtual format for register REGNUM.  */
 152
 153 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)     \
 154   bcopy ((FROM), (TO), 4);
 155
 156 /* Convert data from virtual format for register REGNUM
 157    to raw format for register REGNUM.  */
 158
 159 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
 160   bcopy ((FROM), (TO), 4);
 161
 162 /* Return the GDB type object for the "standard" data type
 163    of data in register N.  */
 164
 165 #define REGISTER_VIRTUAL_TYPE(N) builtin_type_int
 166
 167 /* Store the address of the place in which to copy the structure the
 168    subroutine will return.  This is called from call_function. */
 169
 170 #define STORE_STRUCT_RETURN(ADDR, SP) \
 171   { write_register (1, (ADDR)); }
 172
 173 /* Extract from an array REGBUF containing the (raw) register state
 174    a function return value of type TYPE, and copy that, in virtual format,
 175    into VALBUF.  */
 176
 177 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
 178   bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))
 179
 180 /* Write into appropriate registers a function return value
 181    of type TYPE, given in virtual format.  */
 182
 183 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
 184   write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
 185
 186 /* Extract from an array REGBUF containing the (raw) register state
 187    the address in which a function should return its structure value,
 188    as a CORE_ADDR (or an expression that can be used as one).  */
 189
 190 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
 191
 192 \f
 193 /* Describe the pointer in each stack frame to the previous stack frame
 194    (its caller).  */
 195
 196 /* FRAME_CHAIN takes a frame's nominal address
 197    and produces the frame's chain-pointer. */
 198
 199 /* In the case of the Vax, the frame's nominal address is the FP value,
 200    and 12 bytes later comes the saved previous FP value as a 4-byte word.  */
 201
 202 #define FRAME_CHAIN(thisframe)  \
 203   (!inside_entry_file ((thisframe)->pc) ? \
 204    read_memory_integer ((thisframe)->frame + 12, 4) :\
 205    0)
 206
 207 /* Define other aspects of the stack frame.  */
 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 /* On the vax, all functions have frames.  */
 213 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS)  {(FRAMELESS) = 0;}
 214
 215 /* Saved Pc.  Get it from sigcontext if within sigtramp.  */
 216
 217 /* Offset to saved PC in sigcontext, from <sys/signal.h>.  */
 218 #define SIGCONTEXT_PC_OFFSET 12
 219
 220 #define FRAME_SAVED_PC(FRAME) \
 221   (((FRAME)->signal_handler_caller \
 222     ? sigtramp_saved_pc (FRAME) \
 223     : read_memory_integer ((FRAME)->frame + 16, 4)) \
 224    )
 225
 226 /* Cannot find the AP register value directly from the FP value.  Must
 227    find it saved in the frame called by this one, or in the AP
 228    register for the innermost frame.  However, there is no way to tell
 229    the difference between the innermost frame and a frame for which we
 230    just don't know the frame that it called (e.g. "info frame
 231    0x7ffec789").  For the sake of argument suppose that the stack is
 232    somewhat trashed (which is one reason that "info frame" exists).
 233    So return 0 (indicating we don't know the address of
 234    the arglist) if we don't know what frame this frame calls.  */
 235 #define FRAME_ARGS_ADDRESS_CORRECT(fi) \
 236  (((fi)->next                                  \
 237    ? read_memory_integer ((fi)->next->frame + 8, 4)   \
 238    : /* read_register (AP_REGNUM) */ 0))
 239
 240 /* In most of GDB, getting the args address is too important to
 241    just say "I don't know".  This is sometimes wrong for functions
 242    that aren't on top of the stack, but c'est la vie.  */
 243 #define FRAME_ARGS_ADDRESS(fi) \
 244  (((fi)->next                                  \
 245    ? read_memory_integer ((fi)->next->frame + 8, 4)   \
 246    : read_register (AP_REGNUM) /* 0 */))
 247
 248 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
 249
 250 /* Return number of args passed to a frame.
 251    Can return -1, meaning no way to tell.  */
 252
 253 #define FRAME_NUM_ARGS(numargs, fi)  \
 254 { numargs = (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1)); }
 255
 256 /* Return number of bytes at start of arglist that are not really args.  */
 257
 258 #define FRAME_ARGS_SKIP 4
 259
 260 /* Put here the code to store, into a struct frame_saved_regs,
 261    the addresses of the saved registers of frame described by FRAME_INFO.
 262    This includes special registers such as pc and fp saved in special
 263    ways in the stack frame.  sp is even more special:
 264    the address we return for it IS the sp for the next frame.  */
 265
 266 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
 267 { register int regnum;     \
 268   register int regmask = read_memory_integer ((frame_info)->frame+4, 4) >> 16; \
 269   register CORE_ADDR next_addr;     \
 270   bzero (&frame_saved_regs, sizeof frame_saved_regs);     \
 271   next_addr = (frame_info)->frame + 16;     \
 272   /* Regmask's low bit is for register 0,     \
 273      which is the first one that would be pushed.  */     \
 274   for (regnum = 0; regnum < 12; regnum++, regmask >>= 1)  \
 275     (frame_saved_regs).regs[regnum] = (regmask & 1) ? (next_addr += 4) : 0;  \
 276   (frame_saved_regs).regs[SP_REGNUM] = next_addr + 4;  \
 277   if (read_memory_integer ((frame_info)->frame + 4, 4) & 0x20000000)   \
 278     (frame_saved_regs).regs[SP_REGNUM] += 4 + 4 * read_memory_integer (next_addr + 4, 4);  \
 279   (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 16;  \
 280   (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame + 12;  \
 281   (frame_saved_regs).regs[AP_REGNUM] = (frame_info)->frame + 8;  \
 282   (frame_saved_regs).regs[PS_REGNUM] = (frame_info)->frame + 4;  \
 283 }
 284 \f
 285 /* Things needed for making the inferior call functions.  */
 286
 287 /* Push an empty stack frame, to record the current PC, etc.  */
 288
 289 #define PUSH_DUMMY_FRAME \
 290 { register CORE_ADDR sp = read_register (SP_REGNUM);\
 291   register int regnum;                              \
 292   sp = push_word (sp, 0); /* arglist */             \
 293   for (regnum = 11; regnum >= 0; regnum--)          \
 294     sp = push_word (sp, read_register (regnum));    \
 295   sp = push_word (sp, read_register (PC_REGNUM));   \
 296   sp = push_word (sp, read_register (FP_REGNUM));   \
 297   sp = push_word (sp, read_register (AP_REGNUM));   \
 298   sp = push_word (sp, (read_register (PS_REGNUM) & 0xffef)   \
 299                       + 0x2fff0000);                \
 300   sp = push_word (sp, 0);                           \
 301   write_register (SP_REGNUM, sp);                   \
 302   write_register (FP_REGNUM, sp);                   \
 303   write_register (AP_REGNUM, sp + 17 * sizeof (int)); }
 304
 305 /* Discard from the stack the innermost frame, restoring all registers.  */
 306
 307 #define POP_FRAME  \
 308 { register CORE_ADDR fp = read_register (FP_REGNUM);             \
 309   register int regnum;                                           \
 310   register int regmask = read_memory_integer (fp + 4, 4);        \
 311   write_register (PS_REGNUM,                                     \
 312                   (regmask & 0xffff)                             \
 313                   | (read_register (PS_REGNUM) & 0xffff0000));   \
 314   write_register (PC_REGNUM, read_memory_integer (fp + 16, 4));  \
 315   write_register (FP_REGNUM, read_memory_integer (fp + 12, 4));  \
 316   write_register (AP_REGNUM, read_memory_integer (fp + 8, 4));   \
 317   fp += 16;                                                      \
 318   for (regnum = 0; regnum < 12; regnum++)                        \
 319     if (regmask & (0x10000 << regnum))                           \
 320       write_register (regnum, read_memory_integer (fp += 4, 4)); \
 321   fp = fp + 4 + ((regmask >> 30) & 3);                           \
 322   if (regmask & 0x20000000)                                      \
 323     { regnum = read_memory_integer (fp, 4);                      \
 324       fp += (regnum + 1) * 4; }                                  \
 325   write_register (SP_REGNUM, fp);                                \
 326   flush_cached_frames ();                                        \
 327   set_current_frame (create_new_frame (read_register (FP_REGNUM),\
 328                                         read_pc ())); }
 329
 330 /* This sequence of words is the instructions
 331      calls #69, @#32323232
 332      bpt
 333    Note this is 8 bytes.  */
 334
 335 #define CALL_DUMMY {0x329f69fb, 0x03323232}
 336
 337 #define CALL_DUMMY_START_OFFSET 0  /* Start execution at beginning of dummy */
 338
 339 /* Insert the specified number of args and function address
 340    into a call sequence of the above form stored at DUMMYNAME.  */
 341
 342 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)   \
 343 { *((char *) dummyname + 1) = nargs;            \
 344   *(int *)((char *) dummyname + 3) = fun; }
 345
 346 /* If vax pcc says CHAR or SHORT, it provides the correct address.  */
 347
 348 #define BELIEVE_PCC_PROMOTION 1