gdb/mips-pinsn.c

   1 /* Print mips instructions for GDB, the GNU debugger.
   2    Copyright 1989, 1991 Free Software Foundation, Inc.
   3    Contributed by Nobuyuki Hikichi(hikichi@sra.co.jp)
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #include <stdio.h>
  22
  23 #include "defs.h"
  24 #include "symtab.h"
  25 #include "mips-opcode.h"
  26
  27 /* Mips instructions are never longer than this many bytes.  */
  28 #define MAXLEN 4
  29
  30 /* Number of elements in the opcode table.  */
  31 #define NOPCODES (sizeof mips_opcodes / sizeof mips_opcodes[0])
  32
  33 #define MKLONG(p)  *(unsigned long*)p
  34
  35 extern char *reg_names[];
  36
  37 \f
  38 /* subroutine */
  39 static unsigned char *
  40 print_insn_arg (d, l, stream, pc)
  41      char *d;
  42      register unsigned long int *l;
  43      FILE *stream;
  44      CORE_ADDR pc;
  45 {
  46   switch (*d)
  47     {
  48     case ',':
  49     case '(':
  50     case ')':
  51       fputc (*d, stream);
  52       break;
  53
  54     case 's':
  55       fprintf (stream, "$%s", reg_names[((struct op_i_fmt *) l)->rs]);
  56       break;
  57
  58     case 't':
  59       fprintf (stream, "$%s", reg_names[((struct op_i_fmt *) l)->rt]);
  60       break;
  61
  62     case 'i':
  63       fprintf (stream, "%d", ((struct op_i_fmt *) l)->immediate);
  64       break;
  65
  66     case 'j': /* same as i, but sign-extended */
  67       fprintf (stream, "%d", ((struct op_b_fmt *) l)->delta);
  68       break;
  69
  70     case 'a':
  71       print_address ((pc & 0xF0000000) | (((struct op_j_fmt *)l)->target << 2),
  72                      stream);
  73       break;
  74
  75     case 'b':
  76       print_address ((((struct op_b_fmt *) l)->delta << 2) + pc + 4, stream);
  77       break;
  78
  79     case 'd':
  80       fprintf (stream, "$%s", reg_names[((struct op_r_fmt *) l)->rd]);
  81       break;
  82
  83     case 'h':
  84       fprintf (stream, "0x%x", ((struct op_r_fmt *) l)->shamt);
  85       break;
  86
  87     case 'S':
  88       fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->fs);
  89       break;
  90
  91     case 'T':
  92       fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->ft);
  93       break;
  94
  95     case 'D':
  96       fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->fd);
  97       break;
  98
  99     default:
 100       fprintf (stream, "# internal error, undefined modifier(%c)", *d);
 101       break;
 102     }
 103 }
 104 \f
 105 /* Print the mips instruction at address MEMADDR in debugged memory,
 106    on STREAM.  Returns length of the instruction, in bytes, which
 107    is always 4.  */
 108
 109 int
 110 print_insn (memaddr, stream)
 111      CORE_ADDR memaddr;
 112      FILE *stream;
 113 {
 114   unsigned char buffer[MAXLEN];
 115   register int i;
 116   register char *d;
 117   unsigned long int l;
 118
 119   read_memory (memaddr, buffer, MAXLEN);
 120
 121   for (i = 0; i < NOPCODES; i++)
 122     {
 123       register unsigned int opcode = mips_opcodes[i].opcode;
 124       register unsigned int match = mips_opcodes[i].match;
 125       if ((*(unsigned int*)buffer & match) == opcode)
 126         break;
 127     }
 128
 129   l = MKLONG (buffer);
 130   /* Handle undefined instructions.  */
 131   if (i == NOPCODES)
 132     {
 133       fprintf (stream, "0x%x",l);
 134       return 4;
 135     }
 136
 137   fprintf (stream, "%s", mips_opcodes[i].name);
 138
 139   if (!(d = mips_opcodes[i].args))
 140     return 4;
 141
 142   fputc (' ', stream);
 143
 144   while (*d)
 145     print_insn_arg (d++, &l, stream, memaddr);
 146
 147   return 4;
 148 }