Expose JSON parser through V8 API

BUG=v8:2821
TEST=cctest/test-api/JSONParse
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/21959003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16048 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -1254,6 +1254,22 @@ class V8EXPORT StackFrame {
 };
 
 
+/**
+ * A JSON Parser.
+ */
+class V8EXPORT JSON {
+ public:
+  /**
+   * Tries to parse the string |json_string| and returns it as object if
+   * successful.
+   *
+   * \param json_string The string to parse.
+   * \return The corresponding object if successfully parsed.
+   */
+  static Local<Object> Parse(Local<String> json_string);
+};
+
+
 // --- Value ---
 
 

src/api.cc

@@ -46,6 +46,7 @@
 #include "heap-profiler.h"
 #include "heap-snapshot-generator-inl.h"
 #include "icu_util.h"
+#include "json-parser.h"
 #include "messages.h"
 #ifdef COMPRESS_STARTUP_DATA_BZ2
 #include "natives.h"
@@ -2607,6 +2608,29 @@ bool StackFrame::IsConstructor() const {
 }
 
 
+// --- J S O N ---
+
+Local<Object> JSON::Parse(Local<String> json_string) {
+  i::Isolate* isolate = i::Isolate::Current();
+  EnsureInitializedForIsolate(isolate, "v8::JSON::Parse");
+  ENTER_V8(isolate);
+  i::HandleScope scope(isolate);
+  i::Handle<i::String> source = i::Handle<i::String>(
+      FlattenGetString(Utils::OpenHandle(*json_string)));
+  EXCEPTION_PREAMBLE(isolate);
+  i::Handle<i::Object> result;
+  if (source->IsSeqOneByteString()) {
+    result = i::JsonParser<true>::Parse(source);
+  } else {
+    result = i::JsonParser<false>::Parse(source);
+  }
+  has_pending_exception = result.is_null();
+  EXCEPTION_BAILOUT_CHECK(isolate, Local<Object>());
+  return Utils::ToLocal(
+      i::Handle<i::JSObject>::cast(scope.CloseAndEscape(result)));
+}
+
+
 // --- D a t a ---
 
 bool Value::FullIsUndefined() const {

src/runtime.cc

@@ -9483,7 +9483,7 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ParseJson) {
   ASSERT_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, source, 0);
 
-  source = Handle<String>(source->TryFlattenGetString());
+  source = Handle<String>(FlattenGetString(source));
   // Optimized fast case where we only have ASCII characters.
   Handle<Object> result;
   if (source->IsSeqOneByteString()) {

test/cctest/test-api.cc

@@ -19863,6 +19863,16 @@ THREADED_TEST(Regress260106) {
 }
 
 
+THREADED_TEST(JSONParse) {
+  LocalContext context;
+  HandleScope scope(context->GetIsolate());
+  Local<Object> obj = v8::JSON::Parse(v8_str("{\"x\":42}"));
+  Handle<Object> global = context->Global();
+  global->Set(v8_str("obj"), obj);
+  ExpectString("JSON.stringify(obj)", "{\"x\":42}");
+}
+
+
 #ifndef WIN32
 class ThreadInterruptTest {
  public: