Propagate errors from DartUtils helper functions

runtime/bin/dartutils.h

 // 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.
 
 #ifndef BIN_DARTUTILS_H_
 #define BIN_DARTUTILS_H_
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 
@@ skipping 60 matching lines @@
   int count_;
   int max_count_;
   const char** arguments_;
 
   DISALLOW_COPY_AND_ASSIGN(CommandLineOptions);
 };
 
 
 class DartUtils {
  public:
-  // TODO(turnidge): Clean up the implementations of these so that
-  // they allow for proper error propagation.
-
-  // Assumes that the value object is known to be an integer object
-  // that fits in a signed 64-bit integer.
+  // Returns the integer value of a Dart object. If the object is not
+  // an integer value an API error is propagated.
   static int64_t GetIntegerValue(Dart_Handle value_obj);
-  // Assumes that the value object is known to be an intptr_t. This should
-  // only be known when the value has been put into Dart as a pointer encoded
-  // in a 64-bit integer. This is the case for file and directory operations.
+  // Returns the intptr_t value of a Dart object. If the object is not
+  // an integer value or the value is outside the intptr_t range an
+  // API error is propagated.
   static intptr_t GetIntptrValue(Dart_Handle value_obj);
   // Checks that the value object is an integer object that fits in a
   // signed 64-bit integer. If it is, the value is returned in the
   // value out parameter and true is returned. Otherwise, false is
   // returned.
   static bool GetInt64Value(Dart_Handle value_obj, int64_t* value);
+  // Returns the string value of a Dart object. If the object is not
+  // a string value an API error is propagated.
   static const char* GetStringValue(Dart_Handle str_obj);
+  // Returns the boolean value of a Dart object. If the object is not
+  // a boolean value an API error is propagated.
   static bool GetBooleanValue(Dart_Handle bool_obj);
+
   static void SetIntegerField(Dart_Handle handle,
                               const char* name,
                               intptr_t val);
   static intptr_t GetIntegerField(Dart_Handle handle,
                                   const char* name);
   static void SetStringField(Dart_Handle handle,
                              const char* name,
                              const char* val);
   static bool IsDartSchemeURL(const char* url_name);
   static bool IsDartExtensionSchemeURL(const char* url_name);
@@ skipping 425 matching lines @@
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CObjectExternalUint8Array);
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_DARTUTILS_H_