Add some support for the code-point code-unit distinction.

runtime/vm/scanner.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/scanner.h"
 
 #include "platform/assert.h"
 #include "vm/flags.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ skipping 480 matching lines @@
   }
   if (is_valid &&
       ((*code_point > 0x10FFFF) ||
        ((*code_point & 0xFFFFF800) == 0xD800))) {
     ErrorMsg("invalid code point");
   }
 }
 
 
 void Scanner::ScanLiteralStringChars(bool is_raw) {
-  GrowableArray<uint32_t> string_chars(64);
+  GrowableArray<uint16_t> string_chars(64);
 
   ASSERT(IsScanningString());
   // We are at the first character of a string literal piece. A string literal
   // can be broken up into multiple pieces by string interpolation.
   while (true) {
     if ((c0_ == '\0') || ((c0_ == '\n') && !string_is_multiline_)) {
       ErrorMsg("unterminated string literal");
       EndStringLiteral();
       return;
     }
@@ skipping 15 matching lines @@
           escape_char = '\t';
           break;
         case 'b':
           escape_char = '\b';
           break;
         case 'v':
           escape_char = '\v';
           break;
         case 'u':
         case 'x': {
-          ScanEscapedCodePoint(&escape_char);
+          uint32_t ch;
+          ScanEscapedCodePoint(&ch);
+          int32_t code_point = ch;
+          if (code_point > Utf16::kMaxCodeUnit) {
+            string_chars.Add(Utf16::LeadFromCodePoint(code_point));
+            escape_char = Utf16::TrailFromCodePoint(code_point);
+          } else {
+            escape_char = code_point;
+          }
           break;
         }
         default:
           if ((c0_ == '\0') || ((c0_ == '\n') && !string_is_multiline_)) {
             ErrorMsg("unterminated string literal");
             EndStringLiteral();
             return;
           }
           escape_char = c0_;
           break;
       }
       string_chars.Add(escape_char);
     } else if (c0_ == '$' && !is_raw) {
       // Scanned a string piece.
       ASSERT(string_chars.data() != NULL);
       // Strings are canonicalized: Allocate a symbol.
       current_token_.literal = &String::ZoneHandle(
           Symbols::New(string_chars.data(), string_chars.length()));

[siva, 2012/11/20 00:48:00]

Is the change above necessary considering that this
method calls the uint32 version of String::New which accounts
for supplementary characters.

       // Preserve error tokens.
       if (current_token_.kind != Token::kERROR) {
         current_token_.kind = Token::kSTRING;
       }
       return;
     } else if (c0_ == string_delimiter_) {
       // Check if we are at the end of the string literal.
       if (!string_is_multiline_ ||
           ((LookaheadChar(1) == string_delimiter_) &&
            (LookaheadChar(2) == string_delimiter_))) {
@@ skipping 386 matching lines @@
               "%c%#"Px"", kPrivateKeySeparator, key_value);
   const String& result = String::Handle(String::New(private_key, Heap::kOld));
   return result.raw();
 }
 
 
 void Scanner::InitOnce() {
 }
 
 }  // namespace dart