[turbolizer] Output correct JSON when source contains a backslash.

src/ostreams.cc

 // Copyright 2014 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.
 
 #include "src/ostreams.h"
 #include "src/objects.h"
 
 #if V8_OS_WIN
 #if _MSC_VER < 1900
 #define snprintf sprintf_s
@@ skipping 43 matching lines @@
 bool IsOK(uint16_t c) { return (IsPrint(c) || IsSpace(c)) && c != '\\'; }
 
 
 std::ostream& PrintUC16(std::ostream& os, uint16_t c, bool (*pred)(uint16_t)) {
   char buf[10];
   const char* format = pred(c) ? "%c" : (c <= 0xff) ? "\\x%02x" : "\\u%04x";
   snprintf(buf, sizeof(buf), format, c);
   return os << buf;
 }
 
+std::ostream& PrintUC16ForJSON(std::ostream& os, uint16_t c,
+                               bool (*pred)(uint16_t)) {
+  // JSON does not allow \x99; must use \u0099.
+  char buf[10];
+  const char* format = pred(c) ? "%c" : "\\u%04x";
+  snprintf(buf, sizeof(buf), format, c);
+  return os << buf;
+}
 
 std::ostream& PrintUC32(std::ostream& os, int32_t c, bool (*pred)(uint16_t)) {
   if (c <= String::kMaxUtf16CodeUnit) {
     return PrintUC16(os, static_cast<uint16_t>(c), pred);
   }
   char buf[13];
   snprintf(buf, sizeof(buf), "\\u{%06x}", c);
   return os << buf;
 }
 
 }  // namespace
 
 
 std::ostream& operator<<(std::ostream& os, const AsReversiblyEscapedUC16& c) {
   return PrintUC16(os, c.value, IsOK);
 }
 
 
 std::ostream& operator<<(std::ostream& os, const AsEscapedUC16ForJSON& c) {
   if (c.value == '\n') return os << "\\n";
   if (c.value == '\r') return os << "\\r";
   if (c.value == '\t') return os << "\\t";
   if (c.value == '\"') return os << "\\\"";
-  return PrintUC16(os, c.value, IsOK);
+  return PrintUC16ForJSON(os, c.value, IsOK);
 }
 
 
 std::ostream& operator<<(std::ostream& os, const AsUC16& c) {
   return PrintUC16(os, c.value, IsPrint);
 }
 
 
 std::ostream& operator<<(std::ostream& os, const AsUC32& c) {
   return PrintUC32(os, c.value, IsPrint);
 }
 
 std::ostream& operator<<(std::ostream& os, const AsHex& hex) {
   char buf[20];
   snprintf(buf, sizeof(buf), "%.*" PRIx64, hex.min_width, hex.value);
   return os << buf;
 }
 
 }  // namespace internal
 }  // namespace v8