gdb/vax-tdep.c

   1 /* Print VAX instructions for GDB, the GNU debugger.
   2    Copyright 1986, 1989, 1991, 1992, 1996 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 #include "defs.h"
  21 #include "symtab.h"
  22 #include "opcode/vax.h"
  23
  24 /* Vax instructions are never longer than this.  */
  25 #define MAXLEN 62
  26
  27 /* Number of elements in the opcode table.  */
  28 #define NOPCODES (sizeof votstrs / sizeof votstrs[0])
  29
  30 static unsigned char *print_insn_arg ();
  31 \f
  32 /* Print the vax instruction at address MEMADDR in debugged memory,
  33    from disassembler info INFO.
  34    Returns length of the instruction, in bytes.  */
  35
  36 static int
  37 vax_print_insn (memaddr, info)
  38      CORE_ADDR memaddr;
  39      disassemble_info *info;
  40 {
  41   unsigned char buffer[MAXLEN];
  42   register int i;
  43   register unsigned char *p;
  44   register char *d;
  45
  46   int status = (*info->read_memory_func) (memaddr, buffer, MAXLEN, info);
  47   if (status != 0)
  48     {
  49       (*info->memory_error_func) (status, memaddr, info);
  50       return -1;
  51     }
  52
  53   for (i = 0; i < NOPCODES; i++)
  54     if (votstrs[i].detail.code == buffer[0]
  55         || votstrs[i].detail.code == *(unsigned short *)buffer)
  56       break;
  57
  58   /* Handle undefined instructions.  */
  59   if (i == NOPCODES)
  60     {
  61       (*info->fprintf_func) (info->stream, "0%o", buffer[0]);
  62       return 1;
  63     }
  64
  65   (*info->fprintf_func) (info->stream, "%s", votstrs[i].name);
  66
  67   /* Point at first byte of argument data,
  68      and at descriptor for first argument.  */
  69   p = buffer + 1 + (votstrs[i].detail.code >= 0x100);
  70   d = votstrs[i].detail.args;
  71
  72   if (*d)
  73     (*info->fprintf_func) (info->stream, " ");
  74
  75   while (*d)
  76     {
  77       p = print_insn_arg (d, p, memaddr + (p - buffer), info);
  78       d += 2;
  79       if (*d)
  80         (*info->fprintf_func) (info->stream, ",");
  81     }
  82   return p - buffer;
  83 }
  84
  85 static unsigned char *
  86 print_insn_arg (d, p, addr, info)
  87      char *d;
  88      register char *p;
  89      CORE_ADDR addr;
  90      disassemble_info *info;
  91 {
  92   register int regnum = *p & 0xf;
  93   float floatlitbuf;
  94
  95   if (*d == 'b')
  96     {
  97       if (d[1] == 'b')
  98         (*info->fprintf_func) (info->stream, "0x%x", addr + *p++ + 1);
  99       else
 100         {
 101           (*info->fprintf_func) (info->stream, "0x%x", addr + *(short *)p + 2);
 102           p += 2;
 103         }
 104     }
 105   else
 106     switch ((*p++ >> 4) & 0xf)
 107       {
 108       case 0:
 109       case 1:
 110       case 2:
 111       case 3:                   /* Literal mode */
 112         if (d[1] == 'd' || d[1] == 'f' || d[1] == 'g' || d[1] == 'h')
 113           {
 114             *(int *)&floatlitbuf = 0x4000 + ((p[-1] & 0x3f) << 4);
 115             (*info->fprintf_func) (info->stream, "$%f", floatlitbuf);
 116           }
 117         else
 118           (*info->fprintf_func) (info->stream, "$%d", p[-1] & 0x3f);
 119         break;
 120
 121       case 4:                   /* Indexed */
 122         p = (char *) print_insn_arg (d, p, addr + 1, info);
 123         (*info->fprintf_func) (info->stream, "[%s]", REGISTER_NAME (regnum));
 124         break;
 125
 126       case 5:                   /* Register */
 127         (*info->fprintf_func) (info->stream, REGISTER_NAME (regnum));
 128         break;
 129
 130       case 7:                   /* Autodecrement */
 131         (*info->fprintf_func) (info->stream, "-");
 132       case 6:                   /* Register deferred */
 133         (*info->fprintf_func) (info->stream, "(%s)", REGISTER_NAME (regnum));
 134         break;
 135
 136       case 9:                   /* Autoincrement deferred */
 137         (*info->fprintf_func) (info->stream, "@");
 138         if (regnum == PC_REGNUM)
 139           {
 140             (*info->fprintf_func) (info->stream, "#");
 141             info->target = *(long *)p;
 142             (*info->print_address_func) (info->target, info);
 143             p += 4;
 144             break;
 145           }
 146       case 8:                   /* Autoincrement */
 147         if (regnum == PC_REGNUM)
 148           {
 149             (*info->fprintf_func) (info->stream, "#");
 150             switch (d[1])
 151               {
 152               case 'b':
 153                 (*info->fprintf_func) (info->stream, "%d", *p++);
 154                 break;
 155
 156               case 'w':
 157                 (*info->fprintf_func) (info->stream, "%d", *(short *)p);
 158                 p += 2;
 159                 break;
 160
 161               case 'l':
 162                 (*info->fprintf_func) (info->stream, "%d", *(long *)p);
 163                 p += 4;
 164                 break;
 165
 166               case 'q':
 167                 (*info->fprintf_func) (info->stream, "0x%x%08x",
 168                                        ((long *)p)[1], ((long *)p)[0]);
 169                 p += 8;
 170                 break;
 171
 172               case 'o':
 173                 (*info->fprintf_func) (info->stream, "0x%x%08x%08x%08x",
 174                                        ((long *)p)[3], ((long *)p)[2],
 175                                        ((long *)p)[1], ((long *)p)[0]);
 176                 p += 16;
 177                 break;
 178
 179               case 'f':
 180                 if (INVALID_FLOAT (p, 4))
 181                   (*info->fprintf_func) (info->stream,
 182                                          "<<invalid float 0x%x>>",
 183                                          *(int *) p);
 184                 else
 185                   (*info->fprintf_func) (info->stream, "%f", *(float *) p);
 186                 p += 4;
 187                 break;
 188
 189               case 'd':
 190                 if (INVALID_FLOAT (p, 8))
 191                   (*info->fprintf_func) (info->stream,
 192                                          "<<invalid float 0x%x%08x>>",
 193                                          ((long *)p)[1], ((long *)p)[0]);
 194                 else
 195                   (*info->fprintf_func) (info->stream, "%f", *(double *) p);
 196                 p += 8;
 197                 break;
 198
 199               case 'g':
 200                 (*info->fprintf_func) (info->stream, "g-float");
 201                 p += 8;
 202                 break;
 203
 204               case 'h':
 205                 (*info->fprintf_func) (info->stream, "h-float");
 206                 p += 16;
 207                 break;
 208
 209               }
 210           }
 211         else
 212           (*info->fprintf_func) (info->stream, "(%s)+", REGISTER_NAME (regnum));
 213         break;
 214
 215       case 11:                  /* Byte displacement deferred */
 216         (*info->fprintf_func) (info->stream, "@");
 217       case 10:                  /* Byte displacement */
 218         if (regnum == PC_REGNUM)
 219           {
 220             info->target = addr + *p + 2;
 221             (*info->print_address_func) (info->target, info);
 222           }
 223         else
 224           (*info->fprintf_func) (info->stream, "%d(%s)", *p, REGISTER_NAME (regnum));
 225         p += 1;
 226         break;
 227
 228       case 13:                  /* Word displacement deferred */
 229         (*info->fprintf_func) (info->stream, "@");
 230       case 12:                  /* Word displacement */
 231         if (regnum == PC_REGNUM)
 232           {
 233             info->target = addr + *(short *)p + 3;
 234             (*info->print_address_func) (info->target, info);
 235           }
 236         else
 237           (*info->fprintf_func) (info->stream, "%d(%s)",
 238                                  *(short *)p, REGISTER_NAME (regnum));
 239         p += 2;
 240         break;
 241
 242       case 15:                  /* Long displacement deferred */
 243         (*info->fprintf_func) (info->stream, "@");
 244       case 14:                  /* Long displacement */
 245         if (regnum == PC_REGNUM)
 246           {
 247             info->target = addr + *(short *)p + 5;
 248             (*info->print_address_func) (info->target, info);
 249           }
 250         else
 251           (*info->fprintf_func) (info->stream, "%d(%s)",
 252                                  *(long *)p, REGISTER_NAME (regnum));
 253         p += 4;
 254       }
 255
 256   return (unsigned char *) p;
 257 }
 258
 259 void
 260 _initialize_vax_tdep ()
 261 {
 262   tm_print_insn = vax_print_insn;
 263 }