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