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   { "CMP_EQL", vm_cmp_eql },
  18   { "CMP_NE", vm_cmp_ne },
  19   { "CMP_GEQL", vm_cmp_geql },
  20   { "CMP_LEQL", vm_cmp_leql },
  21   { "CMP_GT", vm_cmp_gt },
  22   { "CMP_LT", vm_cmp_lt },
  23   { "LOAD_VAR", vm_load_var },
  24   { "LOAD_INT", vm_load_int },
  25   { "LOAD_OFF", vm_load_off },
  26   { "STORE", vm_store },
  27   { "JMP_FALSE", vm_jmp_false },
  28   { "GOTO", vm_goto },
  29   { "WRITE_INT", vm_write_int },
  30   { "PUSH_INT", vm_push_int },
  31   { "PUSH_VAR", vm_push_var },
  32   { "CALL", vm_call },
  33   { "RET", vm_ret }
  34 };
  35
  36 int
  37 reserve_loc(void)
  38 {
  39   return code_offset++;
  40 }
  41
  42 int
  43 gen_label(void)
  44 {
  45   return code_offset;
  46 }
  47
  48 void
  49 gen_code(int op, int arg)
  50 {
  51   code[code_offset].op = op;
  52   code[code_offset++].arg = arg;
  53 }
  54
  55 void
  56 back_patch(int addr, int op, int arg)
  57 {
  58   code[addr].op = op;
  59   code[addr].arg = arg;
  60 }
  61
  62 void
  63 print_code(char *outfile)
  64 {
  65   int i;
  66   FILE *fp;
  67
  68   if (outfile) {
  69     fp = fopen(outfile, "w");
  70     if (! fp) {
  71       perror("fopen");
  72       fprintf(stderr, "Erro ao abrir %s\n", outfile);
  73     }
  74   } else {
  75     fp = stdout;
  76   }
  77
  78   for (i = 0; i < code_offset; ++i) {
  79     fprintf(fp, "%d: %s %d\n", i, ops[code[i].op].opname, code[i].arg);
  80   }
  81 }
  82