gdb/mips-pinsn.c

   1 /* Print mips instructions for GDB, the GNU debugger.
   2    Copyright 1989, 1991, 1992 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 "defs.h"
  22 #include "symtab.h"
  23 #include "opcode/mips.h"
  24
  25 /* Mips instructions are never longer than this many bytes.  */
  26 #define MAXLEN 4
  27
  28 /* Number of elements in the opcode table.  */
  29 #define NOPCODES (sizeof mips_opcodes / sizeof mips_opcodes[0])
  30
  31 #define MKLONG(p)  *(unsigned long*)p
  32
  33 extern char *reg_names[];
  34
  35 \f
  36 /* subroutine */
  37 static unsigned char *
  38 print_insn_arg (d, l, stream, pc)
  39      char *d;
  40      register unsigned long int *l;
  41      FILE *stream;
  42      CORE_ADDR pc;
  43 {
  44   switch (*d)
  45     {
  46     case ',':
  47     case '(':
  48     case ')':
  49       fputc (*d, stream);
  50       break;
  51
  52     case 's':
  53       fprintf (stream, "$%s", reg_names[((struct op_i_fmt *) l)->rs]);
  54       break;
  55
  56     case 't':
  57       fprintf (stream, "$%s", reg_names[((struct op_i_fmt *) l)->rt]);
  58       break;
  59
  60     case 'i':
  61       fprintf (stream, "%d", ((struct op_i_fmt *) l)->immediate);
  62       break;
  63
  64     case 'j': /* same as i, but sign-extended */
  65       fprintf (stream, "%d", ((struct op_b_fmt *) l)->delta);
  66       break;
  67
  68     case 'a':
  69       print_address ((pc & 0xF0000000) | (((struct op_j_fmt *)l)->target << 2),
  70                      stream);
  71       break;
  72
  73     case 'b':
  74       print_address ((((struct op_b_fmt *) l)->delta << 2) + pc + 4, stream);
  75       break;
  76
  77     case 'd':
  78       fprintf (stream, "$%s", reg_names[((struct op_r_fmt *) l)->rd]);
  79       break;
  80
  81     case 'h':
  82       fprintf (stream, "0x%x", ((struct op_r_fmt *) l)->shamt);
  83       break;
  84
  85     case 'S':
  86       fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->fs);
  87       break;
  88
  89     case 'T':
  90       fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->ft);
  91       break;
  92
  93     case 'D':
  94       fprintf (stream, "$f%d", ((struct fop_r_fmt *) l)->fd);
  95       break;
  96
  97     default:
  98       fprintf (stream, "# internal error, undefined modifier(%c)", *d);
  99       break;
 100     }
 101 }
 102 \f
 103 /* Print the mips instruction at address MEMADDR in debugged memory,
 104    on STREAM.  Returns length of the instruction, in bytes, which
 105    is always 4.  */
 106
 107 int
 108 print_insn (memaddr, stream)
 109      CORE_ADDR memaddr;
 110      FILE *stream;
 111 {
 112   unsigned char buffer[MAXLEN];
 113   register int i;
 114   register char *d;
 115   unsigned long int l;
 116
 117   read_memory (memaddr, buffer, MAXLEN);
 118   SWAP_TARGET_AND_HOST (buffer, MAXLEN);
 119
 120   for (i = 0; i < NOPCODES; i++)
 121     {
 122       register unsigned int opcode = mips_opcodes[i].opcode;
 123       register unsigned int match = mips_opcodes[i].match;
 124       if ((*(unsigned int*)buffer & match) == opcode)
 125         break;
 126     }
 127
 128   l = MKLONG (buffer);
 129   /* Handle undefined instructions.  */
 130   if (i == NOPCODES)
 131     {
 132       fprintf (stream, "0x%x",l);
 133       return 4;
 134     }
 135
 136   fprintf (stream, "%s", mips_opcodes[i].name);
 137
 138   if (!(d = mips_opcodes[i].args))
 139     return 4;
 140
 141   fputc (' ', stream);
 142
 143   while (*d)
 144     print_insn_arg (d++, &l, stream, memaddr);
 145
 146   return 4;
 147 }