Adds a flag to the standalone vm to throw an exception on 53-bit integer overflow.

runtime/lib/typed_data.cc

Index: runtime/lib/typed_data.cc
===================================================================
--- runtime/lib/typed_data.cc	(revision 23032)
+++ runtime/lib/typed_data.cc	(working copy)
@@ -13,6 +13,8 @@
 
 namespace dart {
 
+DECLARE_FLAG(bool, throw_on_javascript_int_overflow);
+
 // TypedData.
 
 // Checks to see if offset_in_bytes is in the range.
@@ -261,6 +263,9 @@
   } else {                                                                     \
     result = Integer::New(value);                                              \
   }                                                                            \
+  if (FLAG_throw_on_javascript_int_overflow && !result.FitsIn53Bits()) {       \

[siva, 2013/05/23 17:38:57]

Ditto comment about the FitsIn53Bits check here.

+    Integer::CheckForFiftyThreeBitOverflow(result, "TypedData_getter");        \
+  }                                                                            \
   return result.raw();                                                         \
 }                                                                              \
 
@@ -384,7 +389,11 @@
   } else {
     value = Utils::HostToBigEndian64(value);
   }
-  return Integer::New(value);
+  const Integer& i = Integer::Handle(Integer::New(value));
+  if (FLAG_throw_on_javascript_int_overflow && !i.FitsIn53Bits()) {

[siva, 2013/05/23 17:38:57]

Ditto comment about the FitsIn53Bits check here.

+    Integer::CheckForFiftyThreeBitOverflow(i, "ByteData_ToEndianInt64");
+  }
+  return i.raw();
 }
 
 
@@ -406,9 +415,19 @@
     value = Utils::HostToBigEndian64(value);
   }
   if (value > static_cast<uint64_t>(Mint::kMaxValue)) {
-    return BigintOperations::NewFromUint64(value);
+    if (FLAG_throw_on_javascript_int_overflow) {
+      const Array& arg = Array::Handle(Array::New(1));
+      arg.SetAt(0, Object::Handle(String::New("ByteData_ToEndianUint64")));
+      Exceptions::ThrowByType(Exceptions::kFiftyThreeBitOverflowError, arg);
+    } else {
+      return BigintOperations::NewFromUint64(value);
+    }
   }
-  return Integer::New(value);
+  const Integer& i = Integer::Handle(Integer::New(value));
+  if (FLAG_throw_on_javascript_int_overflow && !i.FitsIn53Bits()) {

[siva, 2013/05/23 17:38:57]

Ditto comment about FitsIn53Bits check here.

+    Integer::CheckForFiftyThreeBitOverflow(i, "ByteData_ToEndianUint64");
+  }
+  return i.raw();
 }