Introducing interpreter context flag, indicating if there is call of 'Direct call to eval' form in process, and interfaces for accessing the flag and 'strict mode' flag.

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

Author: Ruben Ayrapetyan

jerry-core/vm/opcodes.cpp

@@ -657,6 +657,8 @@ opfunc_call_n (opcode_t opdata, /**< operation data */
 
   opcode_call_flags_t call_flags = OPCODE_CALL_FLAGS__EMPTY;
 
+  JERRY_ASSERT (!int_data->is_call_in_direct_eval_form);
+
   opcode_t next_opcode = vm_get_opcode (int_data->opcodes_p, int_data->pos);
   if (next_opcode.op_idx == __op__idx_meta
       && next_opcode.data.meta.type == OPCODE_META_TYPE_CALL_SITE_INFO)
@@ -667,6 +669,8 @@ opfunc_call_n (opcode_t opdata, /**< operation data */
     {
       this_arg_var_idx = next_opcode.data.meta.data_2;
       JERRY_ASSERT (is_reg_variable (int_data, this_arg_var_idx));
+
+      JERRY_ASSERT ((call_flags & OPCODE_CALL_FLAGS_DIRECT_CALL_TO_EVAL_FORM) == 0);
     }
 
     int_data->pos++;
@@ -704,6 +708,11 @@ opfunc_call_n (opcode_t opdata, /**< operation data */
     }
     else
     {
+      if (call_flags & OPCODE_CALL_FLAGS_DIRECT_CALL_TO_EVAL_FORM)
+      {
+        int_data->is_call_in_direct_eval_form = true;
+      }
+
       ecma_object_t *func_obj_p = ecma_get_object_from_value (func_value);
 
       ECMA_TRY_CATCH (call_ret_value,
@@ -719,6 +728,15 @@ opfunc_call_n (opcode_t opdata, /**< operation data */
 
       ECMA_FINALIZE (call_ret_value);
 
+      if (call_flags & OPCODE_CALL_FLAGS_DIRECT_CALL_TO_EVAL_FORM)
+      {
+        JERRY_ASSERT (int_data->is_call_in_direct_eval_form);
+        int_data->is_call_in_direct_eval_form = false;
+      }
+      else
+      {
+        JERRY_ASSERT (!int_data->is_call_in_direct_eval_form);
+      }
     }
 
     ecma_free_completion_value (get_this_completion_value);

jerry-core/vm/opcodes.h

@@ -83,7 +83,9 @@ typedef enum : idx_t
   OPCODE_CALL_FLAGS_DIRECT_CALL_TO_EVAL_FORM = (1u << 1)  /**< flag, indicating that call is performed
                                                            *   in form 'eval (...)', i.e. through 'eval' string
                                                            *   without object base (i.e. with lexical environment
-                                                           *   as base), so it can be a direct call to eval */
+                                                           *   as base), so it can be a direct call to eval
+                                                           *   See also: ECMA-262 v5, 15.1.2.1.1
+                                                           */
 } opcode_call_flags_t;
 
 /**
@@ -115,6 +117,8 @@ typedef struct
   ecma_object_t *lex_env_p; /**< current lexical environment */
   bool is_strict; /**< is current code execution mode strict? */
   bool is_eval_code; /**< is current code executed with eval */
+  bool is_call_in_direct_eval_form; /** flag, indicating if there is call of 'Direct call to eval' form in
+                                     *  process (see also: OPCODE_CALL_FLAGS_DIRECT_CALL_TO_EVAL_FORM) */
   idx_t min_reg_num; /**< minimum idx used for register identification */
   idx_t max_reg_num; /**< maximum idx used for register identification */
   ecma_number_t* tmp_num_p; /**< an allocated number (to reduce temporary allocations) */

jerry-core/vm/vm.cpp

@@ -545,6 +545,7 @@ vm_run_from_pos (const opcode_t *opcodes_p, /**< byte-code array */
   int_data.lex_env_p = lex_env_p;
   int_data.is_strict = is_strict;
   int_data.is_eval_code = is_eval_code;
+  int_data.is_call_in_direct_eval_form = false;
   int_data.min_reg_num = min_reg_num;
   int_data.max_reg_num = max_reg_num;
   int_data.tmp_num_p = ecma_alloc_number ();
@@ -604,6 +605,49 @@ vm_get_scope_flags (const opcode_t *opcodes_p, /**< byte-code array */
   return (opcode_scope_code_flags_t) flags_opcode.data.meta.data_1;
 } /* vm_get_scope_flags */
 
+/**
+ * Check whether currently executed code is strict mode code
+ *
+ * @return true - current code is executed in strict mode,
+ *         false - otherwise.
+ */
+bool
+vm_is_strict_mode (void)
+{
+  JERRY_ASSERT (vm_top_context_p != NULL);
+
+  return vm_top_context_p->is_strict;
+} /* vm_is_strict_mode */
+
+/**
+ * Check whether currently performed call (on top of call-stack) is performed in form,
+ * meeting conditions of 'Direct Call to Eval' (see also: ECMA-262 v5, 15.1.2.1.1)
+ *
+ * Warning:
+ *         the function should only be called from implementation
+ *         of built-in 'eval' routine of Global object
+ *
+ * @return true - currently performed call is performed through 'eval' identifier,
+ *                without 'this' argument,
+ *         false - otherwise.
+ */
+bool
+vm_is_direct_eval_form_call (void)
+{
+  if (vm_top_context_p != NULL)
+  {
+    return vm_top_context_p->is_call_in_direct_eval_form;
+  }
+  else
+  {
+    /*
+     * There is no any interpreter context, so call is performed not from a script.
+     * This implies that the call is indirect.
+     */
+    return false;
+  }
+} /* vm_is_direct_eval_form_call */
+
 /**
  * Get this binding of current execution context
  *

jerry-core/vm/vm.h

@@ -34,6 +34,9 @@ extern ecma_completion_value_t vm_run_from_pos (const opcode_t *opcodes_p,
 extern opcode_t vm_get_opcode (const opcode_t*, opcode_counter_t counter);
 extern opcode_scope_code_flags_t vm_get_scope_flags (const opcode_t*, opcode_counter_t counter);
 
+extern bool vm_is_strict_mode (void);
+extern bool vm_is_direct_eval_form_call (void);
+
 extern ecma_value_t vm_get_this_binding (void);
 extern ecma_object_t* vm_get_lex_env (void);