Implement ES2015 class feature (part I.)

This patch is the first milestone of the implementation of this new language element.

Currently supported:
 - Class statement
 - Class expression
 - Static methods

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

Author: rerobika

jerry-core/config.h

@@ -37,6 +37,7 @@
  */
 #ifdef CONFIG_DISABLE_ES2015
 # define CONFIG_DISABLE_ES2015_ARROW_FUNCTION
+# define CONFIG_DISABLE_ES2015_CLASS
 # define CONFIG_DISABLE_ES2015_BUILTIN
 # define CONFIG_DISABLE_ES2015_PROMISE_BUILTIN
 # define CONFIG_DISABLE_ES2015_TEMPLATE_STRINGS

jerry-core/ecma/operations/ecma-function-object.c

@@ -448,6 +448,13 @@ ecma_op_function_call (ecma_object_t *func_obj_p, /**< Function object */
 
       const ecma_compiled_code_t *bytecode_data_p = ecma_op_function_get_compiled_code (ext_func_p);
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+      if (bytecode_data_p->status_flags & CBC_CODE_FLAGS_CLASS_CONSTRUCTOR && !JERRY_CONTEXT (class_invoked_with_new))
+      {
+        return ecma_raise_type_error (ECMA_ERR_MSG ("Class constructor cannot be invoked without 'new'."));
+      }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
       is_strict = (bytecode_data_p->status_flags & CBC_CODE_FLAGS_STRICT_MODE) ? true : false;
       is_no_lex_env = (bytecode_data_p->status_flags & CBC_CODE_FLAGS_LEXICAL_ENV_NOT_NEEDED) ? true : false;
 
@@ -682,6 +689,10 @@ ecma_op_function_construct_simple_or_external (ecma_object_t *func_obj_p, /**< F
    * See also: ecma_object_get_class_name.
    */
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  JERRY_CONTEXT (class_invoked_with_new) = true;
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
   /* 8. */
   ECMA_TRY_CATCH (call_completion,
                   ecma_op_function_call (func_obj_p,
@@ -690,6 +701,10 @@ ecma_op_function_construct_simple_or_external (ecma_object_t *func_obj_p, /**< F
                                          arguments_list_len),
                   ret_value);
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  JERRY_CONTEXT (class_invoked_with_new) = false;
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
   /* 9. */
   if (ecma_is_value_object (call_completion))
   {

jerry-core/jcontext/jcontext.h

@@ -131,6 +131,9 @@ typedef struct
 #ifdef JMEM_STATS
   jmem_heap_stats_t jmem_heap_stats; /**< heap's memory usage statistics */
 #endif /* JMEM_STATS */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  bool class_invoked_with_new; /**< true if class invoked with 'new', false otherwise */
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 } jerry_context_t;
 
 #ifndef CONFIG_ECMA_LCACHE_DISABLE

jerry-core/parser/js/byte-code.h

@@ -549,6 +549,12 @@
               VM_OC_RESOURCE_NAME) \
   CBC_OPCODE (CBC_EXT_LINE, CBC_NO_FLAG, 0, \
               VM_OC_LINE) \
+  CBC_OPCODE (CBC_EXT_SET_UP_PROPERTY, CBC_HAS_LITERAL_ARG, -1, \
+              VM_OC_SET_UP_PROPERTY | VM_OC_GET_STACK_LITERAL) \
+  CBC_OPCODE (CBC_EXT_SET_UP_SETTER, CBC_HAS_LITERAL_ARG | CBC_HAS_LITERAL_ARG2, 0, \
+              VM_OC_SET_UP_SETTER | VM_OC_GET_LITERAL_LITERAL) \
+  CBC_OPCODE (CBC_EXT_SET_UP_GETTER, CBC_HAS_LITERAL_ARG | CBC_HAS_LITERAL_ARG2, 0, \
+              VM_OC_SET_UP_GETTER | VM_OC_GET_LITERAL_LITERAL) \
   \
   /* Binary compound assignment opcodes with pushing the result. */ \
   CBC_EXT_BINARY_LVALUE_OPERATION (CBC_EXT_ASSIGN_ADD, \
@@ -665,6 +671,9 @@ typedef enum
   CBC_CODE_FLAGS_ARROW_FUNCTION = (1u << 7), /**< this function is an arrow function */
   CBC_CODE_FLAGS_STATIC_FUNCTION = (1u << 8), /**< this function is a static snapshot function */
   CBC_CODE_FLAGS_DEBUGGER_IGNORE = (1u << 9), /**< this function should be ignored by debugger */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  CBC_CODE_FLAGS_CLASS_CONSTRUCTOR = (1u << 10), /**< this function is a class constructor */
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 } cbc_code_flags;
 
 #define CBC_OPCODE(arg1, arg2, arg3, arg4) arg1,

jerry-core/parser/js/js-lexer.c

@@ -430,6 +430,16 @@ static const keyword_string_t * const keyword_string_list[9] =
 #undef LEXER_KEYWORD
 #undef LEXER_KEYWORD_END
 
+/**
+ * This macro allows to parse future reserved strict words if the keyword is inside the class body.
+ */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+#define LEXER_INSIDE_CLASS (context_p->status_flags & PARSER_IS_CLASS)
+#else
+#define LEXER_INSIDE_CLASS false
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
+
 /**
  * Parse identifier.
  */
@@ -531,7 +541,7 @@ lexer_parse_identifier (parser_context_t *context_p, /**< context */
       {
         if (keyword_p->type >= LEXER_FIRST_FUTURE_STRICT_RESERVED_WORD)
         {
-          if (context_p->status_flags & PARSER_IS_STRICT)
+          if (context_p->status_flags & PARSER_IS_STRICT && !LEXER_INSIDE_CLASS)
           {
             parser_raise_error (context_p, PARSER_ERR_STRICT_IDENT_NOT_ALLOWED);
           }
@@ -1939,6 +1949,16 @@ lexer_construct_function_object (parser_context_t *context_p, /**< context */
   result_index = context_p->literal_count;
   context_p->literal_count++;
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  if ((extra_status_flags & PARSER_CLASS_IMPLICIT_CONSTRUCTOR) == PARSER_CLASS_IMPLICIT_CONSTRUCTOR)
+  {
+    literal_p->u.bytecode_p = parser_create_class_implicit_constructor (context_p, extra_status_flags);
+    literal_p->type = LEXER_FUNCTION_LITERAL;
+
+    return result_index;
+  }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
 #ifndef CONFIG_DISABLE_ES2015_ARROW_FUNCTION
   if (!(extra_status_flags & PARSER_IS_ARROW_FUNCTION))
   {
@@ -2222,6 +2242,7 @@ lexer_expect_identifier (parser_context_t *context_p, /**< context */
   parser_raise_error (context_p, PARSER_ERR_IDENTIFIER_EXPECTED);
 } /* lexer_expect_identifier */
 
+#ifdef CONFIG_DISABLE_ES2015_CLASS
 /**
  * Description of "get" literal string.
  */
@@ -2238,6 +2259,8 @@ static const lexer_lit_location_t lexer_set_literal =
   (const uint8_t *) "set", 3, LEXER_IDENT_LITERAL, false
 };
 
+#endif /* CONFIG_DISABLE_ES2015_CLASS */
+
 /**
  * Next token must be an identifier.
  */
@@ -2247,6 +2270,15 @@ lexer_expect_object_literal_id (parser_context_t *context_p, /**< context */
 {
   lexer_skip_spaces (context_p);
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  /* Skip empty statements */
+  while (context_p->status_flags & PARSER_IS_CLASS && *context_p->source_p == LIT_CHAR_SEMICOLON)
+  {
+    lexer_next_token (context_p);
+    lexer_skip_spaces (context_p);
+  }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
   context_p->token.line = context_p->line;
   context_p->token.column = context_p->column;
 
@@ -2278,6 +2310,24 @@ lexer_expect_object_literal_id (parser_context_t *context_p, /**< context */
           }
         }
       }
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+      if (!must_be_identifier
+          && context_p->status_flags & PARSER_IS_CLASS
+          && context_p->token.lit_location.length == 6)
+      {
+        lexer_skip_spaces (context_p);
+
+        if (context_p->source_p < context_p->source_end_p
+            && context_p->source_p[0] != LIT_CHAR_COLON)
+        {
+          if (lexer_compare_identifier_to_current (context_p, &lexer_static_literal))
+          {
+            context_p->token.type = LEXER_KEYW_STATIC;
+            return;
+          }
+        }
+      }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 
       create_literal_object = true;
     }
@@ -2313,6 +2363,15 @@ lexer_expect_object_literal_id (parser_context_t *context_p, /**< context */
       }
     }
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+    if (context_p->status_flags & PARSER_IS_CLASS
+        && lexer_compare_identifier_to_current (context_p, &lexer_constructor_literal))
+    {
+      context_p->status_flags |= PARSER_CLASS_CONSTRUCTOR;
+      return;
+    }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
     if (create_literal_object)
     {
       lexer_construct_literal_object (context_p,

jerry-core/parser/js/js-lexer.h

@@ -274,6 +274,48 @@ typedef struct
   uint8_t type;                              /**< literal object type */
 } lexer_lit_object_t;
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+/**
+ * Description of "get" literal string.
+ */
+static const lexer_lit_location_t lexer_get_literal =
+{
+  (const uint8_t *) "get", 3, LEXER_IDENT_LITERAL, false
+};
+
+/**
+ * Description of "set" literal string.
+ */
+static const lexer_lit_location_t lexer_set_literal =
+{
+  (const uint8_t *) "set", 3, LEXER_IDENT_LITERAL, false
+};
+
+/**
+ * Description of "constructor" literal string.
+ */
+static const lexer_lit_location_t lexer_constructor_literal =
+{
+  (const uint8_t *) "constructor", 11, LEXER_STRING_LITERAL, false
+};
+
+/**
+ * Description of "prototype" literal string.
+ */
+static const lexer_lit_location_t lexer_prototype_literal =
+{
+  (const uint8_t *) "prototype", 9, LEXER_STRING_LITERAL, false
+};
+
+/**
+ * Description of "static" literal string.
+ */
+static const lexer_lit_location_t lexer_static_literal =
+{
+  (const uint8_t *) "static", 6, LEXER_IDENT_LITERAL, false
+};
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
 /**
  * @}
  * @}