Allow identifier code points from supplementary multilingual planes.

src/char-predicates.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CHAR_PREDICATES_H_
 #define V8_CHAR_PREDICATES_H_
 
 #include "src/unicode.h"
 
 namespace v8 {
 namespace internal {
 
 // Unicode character predicates as defined by ECMA-262, 3rd,
 // used for lexical analysis.
 
 inline bool IsCarriageReturn(uc32 c);
 inline bool IsLineFeed(uc32 c);
 inline bool IsDecimalDigit(uc32 c);
 inline bool IsHexDigit(uc32 c);
 inline bool IsOctalDigit(uc32 c);
 inline bool IsBinaryDigit(uc32 c);
 inline bool IsRegExpWord(uc32 c);
 inline bool IsRegExpNewline(uc32 c);
 
+
+struct SupplementaryPlanes {
+  static bool IsIDStart(uc32 c);
+  static bool IsIDPart(uc32 c);
+};
+
+
 // ES6 draft section 11.6
 // This includes '_', '$' and '\', and ID_Start according to
 // http://www.unicode.org/reports/tr31/, which consists of categories
 // 'Lu', 'Ll', 'Lt', 'Lm', 'Lo', 'Nl', but excluding properties
 // 'Pattern_Syntax' or 'Pattern_White_Space'.
+// For code points in the SMPs, we can resort to ICU (if available).
 struct IdentifierStart {
-  static inline bool Is(uc32 c) { return unibrow::ID_Start::Is(c); }
+  static inline bool Is(uc32 c) {
+    if (c > 0xFFFF) return SupplementaryPlanes::IsIDStart(c);
+    return unibrow::ID_Start::Is(c);
+  }
 };
 
 
 // ES6 draft section 11.6
 // This includes \u200c and \u200d, and ID_Continue according to
 // http://www.unicode.org/reports/tr31/, which consists of ID_Start,
 // the categories 'Mn', 'Mc', 'Nd', 'Pc', but excluding properties
 // 'Pattern_Syntax' or 'Pattern_White_Space'.
+// For code points in the SMPs, we can resort to ICU (if available).
 struct IdentifierPart {
   static inline bool Is(uc32 c) {
+    if (c > 0xFFFF) return SupplementaryPlanes::IsIDPart(c);
     return unibrow::ID_Start::Is(c) || unibrow::ID_Continue::Is(c);
   }
 };
 
 
 // ES6 draft section 11.2
 // This includes all code points of Unicode category 'Zs'.
 // \u180e stops being one as of Unicode 6.3.0, but ES6 adheres to Unicode 5.1,
 // so it is also included.
 // Further included are \u0009, \u000b, \u0020, \u00a0, \u000c, and \ufeff.
+// There are no category 'Zs' code points in the SMPs.
 struct WhiteSpace {
   static inline bool Is(uc32 c) { return unibrow::WhiteSpace::Is(c); }
 };
 
 
 // WhiteSpace and LineTerminator according to ES6 draft section 11.2 and 11.3
 // This consists of \000a, \000d, \u2028, and \u2029.
 struct WhiteSpaceOrLineTerminator {
   static inline bool Is(uc32 c) {
     return WhiteSpace::Is(c) || unibrow::LineTerminator::Is(c);
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_CHAR_PREDICATES_H_