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

runtime/lib/double.cc

 // Copyright (c) 2011, 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 <math.h>
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/code_generator.h"  // DartModulo.
 #include "vm/double_conversion.h"
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
+DECLARE_FLAG(bool, throw_on_javascript_int_overflow);
 DECLARE_FLAG(bool, trace_intrinsified_natives);
 
 DEFINE_NATIVE_ENTRY(Double_doubleFromInteger, 2) {
   ASSERT(AbstractTypeArguments::CheckedHandle(
       arguments->NativeArgAt(0)).IsNull());
   const Integer& value = Integer::CheckedHandle(arguments->NativeArgAt(1));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Double_doubleFromInteger %s\n", value.ToCString());
   }
   return Double::New(value.AsDoubleValue());
@@ skipping 45 matching lines @@
 
 
 static RawInteger* DoubleToInteger(double val, const char* error_msg) {
   if (isinf(val) || isnan(val)) {
     const Array& args = Array::Handle(Array::New(1));
     args.SetAt(0, String::Handle(String::New(error_msg)));
     Exceptions::ThrowByType(Exceptions::kUnsupported, args);
   }
   const Bigint& big = Bigint::Handle(BigintOperations::NewFromDouble(val));
   if (BigintOperations::FitsIntoInt64(big)) {
-    return Integer::New(BigintOperations::ToInt64(big));
+    const Integer& i = Integer::Handle(
+        Integer::New(BigintOperations::ToInt64(big)));
+    if (FLAG_throw_on_javascript_int_overflow && !i.FitsIn53Bits()) {

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

just
if (FLAG_throw_on_javascript_int_overflow) {
 ....
}

The FitsIn53Bits check is already inside CheckForFifty...

+      Integer::CheckForFiftyThreeBitOverflow(i, "DoubleToInteger");
+    }
+    return i.raw();
   } else {
     return big.raw();
   }
 }
 
 DEFINE_NATIVE_ENTRY(Double_trunc_div, 2) {
   double left = Double::CheckedHandle(arguments->NativeArgAt(0)).value();
   GET_NON_NULL_NATIVE_ARGUMENT(Double, right_object, arguments->NativeArgAt(1));
   double right = right_object.value();
   if (FLAG_trace_intrinsified_natives) {
@@ skipping 261 matching lines @@
 
 DEFINE_NATIVE_ENTRY(Double_getIsNegative, 1) {
   const Double& arg = Double::CheckedHandle(arguments->NativeArgAt(0));
   // Include negative zero, infinity.
   return Bool::Get(signbit(arg.value()) && !isnan(arg.value()));
 }
 
 // Add here only functions using/referring to old-style casts.
 
 }  // namespace dart