Introducing 'scope flags' opcode containing set of flags that indicate various properties of a scope; replacing 'strict mode' meta opcode with a flag in the flags set.

JerryScript-DCO-1.0-Signed-off-by: Ruben Ayrapetyan r.ayrapetyan@samsung.com

jerry-core/vm/opcodes.cpp

@@ -449,13 +449,11 @@ function_declaration (int_data_t *int_data, /**< interpreter context */
     read_meta_opcode_counter (OPCODE_META_TYPE_FUNCTION_END, int_data) + int_data->pos);
   int_data->pos++;
 
-  opcode_t next_opcode = vm_get_opcode (int_data->pos);
-  if (next_opcode.op_idx == __op__idx_meta
-      && next_opcode.data.meta.type == OPCODE_META_TYPE_STRICT_CODE)
+  opcode_scope_code_flags_t scope_flags = vm_get_scope_flags (int_data->pos++);
+
+  if (scope_flags & OPCODE_SCOPE_CODE_FLAGS_STRICT)
   {
     is_strict = true;
-
-    int_data->pos++;
   }
 
   ecma_string_t *function_name_string_p = ecma_new_ecma_string_from_lit_index (function_name_lit_id);
@@ -548,13 +546,11 @@ opfunc_func_expr_n (opcode_t opdata, /**< operation data */
                                                                        int_data) + int_data->pos);
   int_data->pos++;
 
-  opcode_t next_opcode = vm_get_opcode (int_data->pos);
-  if (next_opcode.op_idx == __op__idx_meta
-      && next_opcode.data.meta.type == OPCODE_META_TYPE_STRICT_CODE)
+  opcode_scope_code_flags_t scope_flags = vm_get_scope_flags (int_data->pos++);
+
+  if (scope_flags & OPCODE_SCOPE_CODE_FLAGS_STRICT)
   {
     is_strict = true;
-
-    int_data->pos++;
   }
 
   ecma_object_t *scope_p;
@@ -1651,7 +1647,7 @@ opfunc_meta (opcode_t opdata, /**< operation data */
       return ecma_make_meta_completion_value ();
     }
 
-    case OPCODE_META_TYPE_STRICT_CODE:
+    case OPCODE_META_TYPE_SCOPE_CODE_FLAGS:
     case OPCODE_META_TYPE_UNDEFINED:
     case OPCODE_META_TYPE_THIS_ARG:
     case OPCODE_META_TYPE_FUNCTION_END:

jerry-core/vm/opcodes.h

@@ -70,9 +70,19 @@ typedef enum
   OPCODE_META_TYPE_CATCH_EXCEPTION_IDENTIFIER, /**< literal index containing name of variable with exception object */
   OPCODE_META_TYPE_FINALLY, /**< mark of beginning of finally block containing pointer to end of finally block */
   OPCODE_META_TYPE_END_TRY_CATCH_FINALLY, /**< mark of end of try-catch, try-finally, try-catch-finally blocks */
-  OPCODE_META_TYPE_STRICT_CODE /**< mark of beginning of strict code */
+  OPCODE_META_TYPE_SCOPE_CODE_FLAGS /**< set of flags indicating various properties of the scope's code
+                                     *   (See also: opcode_scope_code_flags_t) */
 } opcode_meta_type;
 
+/**
+ * Flags indicating various properties of a scope's code
+ */
+typedef enum : idx_t
+{
+  OPCODE_SCOPE_CODE_FLAGS__NO_FLAGS         = (0u),      /**< initializer for empty flag set */
+  OPCODE_SCOPE_CODE_FLAGS_STRICT            = (1u << 0), /**< code is strict mode code */
+} opcode_scope_code_flags_t;
+
 /**
  * Interpreter context
  */

jerry-core/vm/pretty-printer.cpp

@@ -625,9 +625,18 @@ pp_op_meta (opcode_counter_t oc, op_meta opm, bool rewrite)
           printf ("end try");
           break;
         }
-        case OPCODE_META_TYPE_STRICT_CODE:
+        case OPCODE_META_TYPE_SCOPE_CODE_FLAGS:
         {
-          printf ("use strict;");
+          idx_t scope_flags = opm.op.data.meta.data_1;
+
+          if (scope_flags & OPCODE_SCOPE_CODE_FLAGS_STRICT)
+          {
+            printf ("[use strict] ");
+            scope_flags &= (idx_t) ~(OPCODE_SCOPE_CODE_FLAGS_STRICT);
+          }
+
+          JERRY_ASSERT (scope_flags == 0);
+
           break;
         }
         default:

jerry-core/vm/vm.cpp

@@ -366,12 +366,11 @@ vm_run_global (void)
   bool is_strict = false;
   opcode_counter_t start_pos = 0;
 
-  opcode_t first_opcode = vm_get_opcode (start_pos);
-  if (first_opcode.op_idx == __op__idx_meta
-      && first_opcode.data.meta.type == OPCODE_META_TYPE_STRICT_CODE)
+  opcode_scope_code_flags_t scope_flags = vm_get_scope_flags (start_pos++);
+
+  if (scope_flags & OPCODE_SCOPE_CODE_FLAGS_STRICT)
   {
     is_strict = true;
-    start_pos++;
   }
 
   ecma_object_t *glob_obj_p = ecma_builtin_get (ECMA_BUILTIN_ID_GLOBAL);
@@ -557,6 +556,20 @@ vm_get_opcode (opcode_counter_t counter) /**< opcode counter */
   return __program[ counter ];
 } /* vm_get_opcode */
 
+/**
+ * Get scope code flags from opcode specified by opcode counter
+ *
+ * @return mask of scope code flags
+ */
+opcode_scope_code_flags_t
+vm_get_scope_flags (opcode_counter_t counter) /**< opcode counter */
+{
+  opcode_t flags_opcode = vm_get_opcode (counter);
+  JERRY_ASSERT (flags_opcode.op_idx == __op__idx_meta
+                && flags_opcode.data.meta.type == OPCODE_META_TYPE_SCOPE_CODE_FLAGS);
+  return (opcode_scope_code_flags_t) flags_opcode.data.meta.data_1;
+} /* vm_get_scope_flags */
+
 /**
  * Get this binding of current execution context
  *

jerry-core/vm/vm.h

@@ -30,6 +30,7 @@ extern ecma_completion_value_t vm_run_from_pos (opcode_counter_t start_pos,
                                                 bool is_eval_code);
 
 extern opcode_t vm_get_opcode (opcode_counter_t counter);
+extern opcode_scope_code_flags_t vm_get_scope_flags (opcode_counter_t counter);
 
 extern ecma_value_t vm_get_this_binding (void);
 extern ecma_object_t* vm_get_lex_env (void);