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/api/jerry-snapshot.c

@@ -34,9 +34,11 @@
  * @return configuration flags
  */
 static inline uint32_t JERRY_ATTR_ALWAYS_INLINE
-snapshot_get_global_flags (bool has_regex) /**< regex literal is present */
+snapshot_get_global_flags (bool has_regex, /**< regex literal is present */
+                           bool has_class) /**< class literal is present */
 {
   JERRY_UNUSED (has_regex);
+  JERRY_UNUSED (has_class);
 
   uint32_t flags = 0;
 
@@ -45,7 +47,10 @@ snapshot_get_global_flags (bool has_regex) /**< regex literal is present */
 #endif /* JERRY_CPOINTER_32_BIT */
 #ifndef CONFIG_DISABLE_REGEXP_BUILTIN
   flags |= (has_regex ? JERRY_SNAPSHOT_HAS_REGEX_LITERAL : 0);
-#endif /* CONFIG_DISABLE_REGEXP_BUILTIN */
+#endif /* !CONFIG_DISABLE_REGEXP_BUILTIN */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  flags |= (has_class ? JERRY_SNAPSHOT_HAS_CLASS_LITERAL : 0);
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 
   return flags;
 } /* snapshot_get_global_flags */
@@ -61,8 +66,11 @@ snapshot_check_global_flags (uint32_t global_flags) /**< global flags */
 #ifndef CONFIG_DISABLE_REGEXP_BUILTIN
   global_flags &= (uint32_t) ~JERRY_SNAPSHOT_HAS_REGEX_LITERAL;
 #endif /* !CONFIG_DISABLE_REGEXP_BUILTIN */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  global_flags &= (uint32_t) ~JERRY_SNAPSHOT_HAS_CLASS_LITERAL;
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 
-  return global_flags == snapshot_get_global_flags (false);
+  return global_flags == snapshot_get_global_flags (false, false);
 } /* snapshot_check_global_flags */
 
 #endif /* JERRY_ENABLE_SNAPSHOT_SAVE || JERRY_ENABLE_SNAPSHOT_EXEC */
@@ -77,6 +85,7 @@ typedef struct
   size_t snapshot_buffer_write_offset;
   ecma_value_t snapshot_error;
   bool regex_found;
+  bool class_found;
 } snapshot_globals_t;
 
 /** \addtogroup jerrysnapshot Jerry snapshot operations
@@ -154,6 +163,13 @@ snapshot_add_compiled_code (ecma_compiled_code_t *compiled_code_p, /**< compiled
   uint8_t *copied_code_start_p = snapshot_buffer_p + globals_p->snapshot_buffer_write_offset;
   ecma_compiled_code_t *copied_code_p = (ecma_compiled_code_t *) copied_code_start_p;
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  if (compiled_code_p->status_flags & CBC_CODE_FLAGS_CONSTRUCTOR)
+  {
+    globals_p->class_found = true;
+  }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
 #ifndef CONFIG_DISABLE_REGEXP_BUILTIN
   if (!(compiled_code_p->status_flags & CBC_CODE_FLAGS_FUNCTION))
   {
@@ -739,6 +755,7 @@ jerry_generate_snapshot_with_args (const jerry_char_t *resource_name_p, /**< scr
   globals.snapshot_buffer_write_offset = aligned_header_size;
   globals.snapshot_error = ECMA_VALUE_EMPTY;
   globals.regex_found = false;
+  globals.class_found = false;
 
   parse_status = parser_parse_script (args_p,
                                       args_size,
@@ -769,7 +786,7 @@ jerry_generate_snapshot_with_args (const jerry_char_t *resource_name_p, /**< scr
   jerry_snapshot_header_t header;
   header.magic = JERRY_SNAPSHOT_MAGIC;
   header.version = JERRY_SNAPSHOT_VERSION;
-  header.global_flags = snapshot_get_global_flags (globals.regex_found);
+  header.global_flags = snapshot_get_global_flags (globals.regex_found, globals.class_found);
   header.lit_table_offset = (uint32_t) globals.snapshot_buffer_write_offset;
   header.number_of_funcs = 1;
   header.func_offsets[0] = aligned_header_size;

jerry-core/api/jerry-snapshot.h

@@ -41,7 +41,7 @@ typedef struct
 /**
  * Jerry snapshot format version.
  */
-#define JERRY_SNAPSHOT_VERSION (14u)
+#define JERRY_SNAPSHOT_VERSION (15u)
 
 /**
  * Snapshot configuration flags.
@@ -50,6 +50,7 @@ typedef enum
 {
   /* 8 bits are reserved for dynamic features */
   JERRY_SNAPSHOT_HAS_REGEX_LITERAL = (1u << 0), /**< byte code has regex literal */
+  JERRY_SNAPSHOT_HAS_CLASS_LITERAL = (1u << 1), /**< byte code has class literal */
   /* 24 bits are reserved for compile time features */
   JERRY_SNAPSHOT_FOUR_BYTE_CPOINTER = (1u << 8) /**< compressed pointers are four byte long */
 } jerry_snapshot_global_flags_t;

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

@@ -402,6 +402,14 @@ ecma_op_function_has_instance (ecma_object_t *func_obj_p, /**< Function object *
   return ecma_make_boolean_value (result);
 } /* ecma_op_function_has_instance */
 
+
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+/**
+ * Indicates whether the class has been invoked with 'new'.
+ */
+#define ECMA_CLASS_CONSTRUCT_FLAG ((uintptr_t) 0x01u)
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
 /**
  * Sets the construct flag in the arguments list pointer.
  *
@@ -413,8 +421,10 @@ ecma_op_function_set_construct_flag (const ecma_value_t *arguments_list_p) /**<
   /* Any ecma value list must be aligned to 4 byte. */
   JERRY_ASSERT ((((uintptr_t) arguments_list_p) & 0x3) == 0);
 
-  /* Currently it returns with the same pointer. When classes
-   * will be enabled, it will set the lowest bit. */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  arguments_list_p = (const ecma_value_t *)(((uintptr_t) arguments_list_p) | ECMA_CLASS_CONSTRUCT_FLAG);
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
   return arguments_list_p;
 } /* ecma_op_function_set_construct_flag */
 
@@ -426,8 +436,10 @@ ecma_op_function_set_construct_flag (const ecma_value_t *arguments_list_p) /**<
 static inline const ecma_value_t * JERRY_ATTR_ALWAYS_INLINE
 ecma_op_function_clear_construct_flag (const ecma_value_t *arguments_list_p) /**< modified arguments list pointer */
 {
-  /* Currently it returns with the same pointer. When classes
-   * will be enabled, the lowest bit will be cleared. */
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  arguments_list_p = (const ecma_value_t *)(((uintptr_t) arguments_list_p) & ~ECMA_CLASS_CONSTRUCT_FLAG);
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
   return arguments_list_p;
 } /* ecma_op_function_clear_construct_flag */
 
@@ -439,8 +451,12 @@ ecma_op_function_clear_construct_flag (const ecma_value_t *arguments_list_p) /**
 static inline bool JERRY_ATTR_ALWAYS_INLINE
 ecma_op_function_has_construct_flag (const ecma_value_t *arguments_list_p) /**< modified arguments list pointer */
 {
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  return (((uintptr_t) arguments_list_p) & ECMA_CLASS_CONSTRUCT_FLAG);
+#else
   JERRY_UNUSED (arguments_list_p);
   return false;
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 } /* ecma_op_function_has_construct_flag */
 
 /**
@@ -496,6 +512,14 @@ 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_CONSTRUCTOR &&
+          !ecma_op_function_has_construct_flag (arguments_list_p))
+      {
+        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;
 

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

@@ -551,6 +551,12 @@
               VM_OC_RESOURCE_NAME) \
   CBC_OPCODE (CBC_EXT_LINE, CBC_NO_FLAG, 0, \
               VM_OC_LINE) \
+  CBC_OPCODE (CBC_EXT_SET_STATIC_PROPERTY, CBC_HAS_LITERAL_ARG | CBC_HAS_LITERAL_ARG2, 0, \
+              VM_OC_SET_PROPERTY | VM_OC_GET_LITERAL_LITERAL) \
+  CBC_OPCODE (CBC_EXT_SET_STATIC_SETTER, CBC_HAS_LITERAL_ARG | CBC_HAS_LITERAL_ARG2, 0, \
+              VM_OC_SET_SETTER | VM_OC_GET_LITERAL_LITERAL) \
+  CBC_OPCODE (CBC_EXT_SET_STATIC_GETTER, CBC_HAS_LITERAL_ARG | CBC_HAS_LITERAL_ARG2, 0, \
+              VM_OC_SET_GETTER | VM_OC_GET_LITERAL_LITERAL) \
   \
   /* Binary compound assignment opcodes with pushing the result. */ \
   CBC_EXT_BINARY_LVALUE_OPERATION (CBC_EXT_ASSIGN_ADD, \
@@ -667,6 +673,7 @@ 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 */
+  CBC_CODE_FLAGS_CONSTRUCTOR = (1u << 10), /**< this function is a constructor */
 } cbc_code_flags;
 
 #define CBC_OPCODE(arg1, arg2, arg3, arg4) arg1,

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

@@ -277,6 +277,23 @@ lexer_skip_spaces (parser_context_t *context_p) /**< context */
   }
 } /* lexer_skip_spaces */
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+/**
+ * Skip all the continuous empty statements.
+ */
+void
+lexer_skip_empty_statements (parser_context_t *context_p) /**< context */
+{
+  lexer_skip_spaces (context_p);
+
+  while (*context_p->source_p == LIT_CHAR_SEMICOLON)
+  {
+    lexer_next_token (context_p);
+    lexer_skip_spaces (context_p);
+  }
+} /* lexer_skip_empty_statements */
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
 /**
  * Keyword data.
  */
@@ -1308,6 +1325,25 @@ lexer_check_colon (parser_context_t *context_p) /**< context */
           && context_p->source_p[0] == (uint8_t) LIT_CHAR_COLON);
 } /* lexer_check_colon */
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+/**
+ * Checks whether the next token is a left parenthesis.
+ *
+ * @return true - if the next token is a left parenthesis
+ *         false - otherwise
+ */
+bool
+lexer_check_left_paren (parser_context_t *context_p) /**< context */
+{
+  lexer_skip_spaces (context_p);
+
+  context_p->token.flags = (uint8_t) (context_p->token.flags | LEXER_NO_SKIP_SPACES);
+
+  return (context_p->source_p < context_p->source_end_p
+          && context_p->source_p[0] == (uint8_t) LIT_CHAR_LEFT_PAREN);
+} /* lexer_check_left_paren */
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
 #ifndef CONFIG_DISABLE_ES2015_ARROW_FUNCTION
 
 /**
@@ -2231,6 +2267,10 @@ lexer_expect_object_literal_id (parser_context_t *context_p, /**< context */
 {
   lexer_skip_spaces (context_p);
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+  bool is_static_method = (context_p->token.type == LEXER_KEYW_STATIC);
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
+
   context_p->token.line = context_p->line;
   context_p->token.column = context_p->column;
 
@@ -2262,6 +2302,17 @@ lexer_expect_object_literal_id (parser_context_t *context_p, /**< context */
           }
         }
       }
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+      if ((context_p->status_flags & PARSER_IS_CLASS)
+          && !must_be_identifier
+          && !is_static_method
+          && context_p->token.lit_location.length == 6
+          && lexer_compare_raw_identifier_to_current (context_p, "static", 6))
+      {
+        context_p->token.type = LEXER_KEYW_STATIC;
+        return;
+      }
+#endif /* !CONFIG_DISABLE_ES2015_CLASS */
 
       create_literal_object = true;
     }
@@ -2297,6 +2348,17 @@ lexer_expect_object_literal_id (parser_context_t *context_p, /**< context */
       }
     }
 
+#ifndef CONFIG_DISABLE_ES2015_CLASS
+    if ((context_p->status_flags & PARSER_IS_CLASS)
+        && !must_be_identifier
+        && !is_static_method
+        && lexer_compare_raw_identifier_to_current (context_p, "constructor", 11))
+    {
+      context_p->token.type = LEXER_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

@@ -149,6 +149,7 @@ typedef enum
   LEXER_PROPERTY_SETTER,         /**< property setter function */
   LEXER_COMMA_SEP_LIST,          /**< comma separated bracketed expression list */
   LEXER_SCAN_SWITCH,             /**< special value for switch pre-scan */
+  LEXER_CLASS_CONSTRUCTOR,       /**< special value for class constructor method */
 
   /* Future reserved words: these keywords
    * must form a group after all other keywords. */