Add string encoding to wire protocol

runtime/platform/json.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 "platform/json.h"
 
 #include "platform/assert.h"
 #include "platform/globals.h"
 #include "platform/utils.h"
 #include "vm/os.h"
@@ skipping 74 matching lines @@
 void JSONScanner::ScanString() {
   ASSERT(*current_pos_ == '"');
   ++current_pos_;
   token_start_ = current_pos_;
   while (*current_pos_ != '"') {
     if (*current_pos_ == '\0') {
       token_length_ = 0;
       token_ = TokenIllegal;
       return;
     } else if (*current_pos_ == '\\') {
-      // TODO(hausner): Implement escape sequence.
-      UNIMPLEMENTED();
+      ++current_pos_;
+      if (*current_pos_ == '"') {
+        // Consume escaped double quote.
+        ++current_pos_;
+      }
     } else if (*current_pos_ < 0) {
       // UTF-8 not supported.
       token_length_ = 0;
       token_ = TokenIllegal;
       return;
     } else {
       ++current_pos_;
     }
   }
   token_ = TokenString;
@@ skipping 259 matching lines @@
     intptr_t len2 = OS::VSNPrint(buf_ + msg_len_, remaining, format, args2);
     va_end(args2);
     ASSERT(len == len2);
   }
   msg_len_ += len;
   buf_[msg_len_] = '\0';
   return len;
 }
 
 
+void TextBuffer::PrintJsonString8(const uint8_t* codepoints, intptr_t length) {
+  for (intptr_t i = 0; i < length; i++) {
+    uint8_t cp = codepoints[i];
+    switch (cp) {
+      case '"':
+        Printf("%s", "\\\"");
+        break;
+      case '\\':
+        Printf("%s", "\\\\");
+        break;
+      case '/':
+        Printf("%s", "\\/");
+        break;
+      case '\b':
+        Printf("%s", "\\b");
+        break;
+      case '\f':
+        Printf("%s", "\\f");
+        break;
+      case '\n':
+        Printf("%s", "\\n");
+        break;
+      case '\r':
+        Printf("%s", "\\r");
+        break;
+      case '\t':
+        Printf("%s", "\\t");
+        break;
+      default:
+        if ((0x20 <= cp) && (cp <= 0x7e)) {
+          Printf("%c", cp);
+        } else {
+          // Encode character as \u00HH.
+          uint8_t digit2 = (cp & 0xf0) >> 4;
+          uint8_t digit3 = cp & 0xf;
+          Printf("\\u00%c%c",
+            digit2 > 9 ? 'A' + (digit2 - 10) : '0' + digit2,
+            digit3 > 9 ? 'A' + (digit3 - 10) : '0' + digit3);
+        }
+    }
+  }
+}
+
+
 void TextBuffer::GrowBuffer(intptr_t len) {
   intptr_t new_size = buf_size_ + len;
   char* new_buf = reinterpret_cast<char*>(realloc(buf_, new_size));
   ASSERT(new_buf != NULL);
   buf_ = new_buf;
   buf_size_ = new_size;
 }
 
 }  // namespace dart