better codedump format

src/codegen.c

@@ -2734,7 +2734,7 @@ codedump(mrb_state *mrb, mrb_irep *irep)
       break;
 
     case OP_LAMBDA:
-      printf("OP_LAMBDA\tR%d\tI(%+d)\t%d\n", GETARG_A(c), GETARG_b(c), GETARG_c(c));
+      printf("OP_LAMBDA\tR%d\tI(%+d)\t%d\n", GETARG_A(c), GETARG_b(c)+1, GETARG_c(c));
       break;
     case OP_RANGE:
       printf("OP_RANGE\tR%d\tR%d\t%d\n", GETARG_A(c), GETARG_B(c), GETARG_C(c));
@@ -2845,7 +2845,7 @@ codedump(mrb_state *mrb, mrb_irep *irep)
              mrb_sym2name(mrb, irep->syms[GETARG_B(c)]));
       break;
     case OP_EXEC:
-      printf("OP_EXEC\tR%d\tI(%+d)\n", GETARG_A(c), GETARG_Bx(c));
+      printf("OP_EXEC\tR%d\tI(%+d)\n", GETARG_A(c), GETARG_Bx(c)+1);
       break;
     case OP_SCLASS:
       printf("OP_SCLASS\tR%d\tR%d\n", GETARG_A(c), GETARG_B(c));
@@ -2854,10 +2854,14 @@ codedump(mrb_state *mrb, mrb_irep *irep)
       printf("OP_TCLASS\tR%d\n", GETARG_A(c));
       break;
     case OP_ERR:
-      printf("OP_ERR\tL(%d)\n", GETARG_Bx(c));
+      {
+        mrb_value v = irep->pool[GETARG_Bx(c)];
+        mrb_value s = mrb_str_dump(mrb, mrb_str_new(mrb, RSTRING_PTR(v), RSTRING_LEN(v)));
+        printf("OP_ERR\t%s\n", RSTRING_PTR(s));
+      }
       break;
     case OP_EPUSH:
-      printf("OP_EPUSH\t:I(%+d)\n", GETARG_Bx(c));
+      printf("OP_EPUSH\t:I(%+d)\n", GETARG_Bx(c)+1);
       break;
     case OP_ONERR:
       printf("OP_ONERR\t%03d\n", i+GETARG_sBx(c));