code.c

   1 #include <stdio.h>
   2 #include "code.h"
   3 #include "vm.h"
   4
   5 #define SEG_SIZE 4096
   6
   7 int code_offset = 0;
   8 code_t code[SEG_SIZE];
   9
  10 struct ops ops[] = {
  11   { "HALT", vm_halt },
  12   { "ADD", vm_add },
  13   { "SUB", vm_sub },
  14   { "MUL", vm_mul },
  15   { "DIV", vm_div },
  16   { "MOD", vm_mod },
  17   { "LOAD_VAR", vm_load_var },
  18   { "LOAD_INT", vm_load_int },
  19   { "STORE", vm_store },
  20   { "JMP_FALSE", vm_jmp_false },
  21   { "GOTO", vm_goto },
  22   { "WRITE_INT", vm_write_int },
  23   { "PUSH_INT", vm_push_int },
  24   { "PUSH_VAR", vm_push_var },
  25   { "CALL", vm_call },
  26   { "RET", vm_ret }
  27 };
  28
  29 int
  30 reserve_loc(void)
  31 {
  32   return code_offset++;
  33 }
  34
  35 int
  36 gen_label(void)
  37 {
  38   return code_offset;
  39 }
  40
  41 void
  42 gen_code(int op, int arg)
  43 {
  44   code[code_offset].op = op;
  45   code[code_offset++].arg = arg;
  46 }
  47
  48 void
  49 back_patch(int addr, int op, int arg)
  50 {
  51   code[addr].op = op;
  52   code[addr].arg = arg;
  53 }
  54
  55 void
  56 print_code(char *outfile)
  57 {
  58   int i;
  59   FILE *fp;
  60
  61   if (outfile) {
  62     fp = fopen(outfile, "w");
  63     if (! fp) {
  64       perror("fopen");
  65       fprintf(stderr, "Erro ao abrir %s\n", outfile);
  66     }
  67   } else {
  68     fp = stdout;
  69   }
  70
  71   for (i = 0; i < code_offset; ++i) {
  72     fprintf(fp, "%d: %s %d\n", i, ops[code[i].op].opname, code[i].arg);
  73   }
  74 }
  75