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

runtime/lib/integers.cc

Index: runtime/lib/integers.cc
===================================================================
--- runtime/lib/integers.cc	(revision 23032)
+++ runtime/lib/integers.cc	(working copy)
@@ -13,6 +13,9 @@
 
 namespace dart {
 
+DEFINE_FLAG(bool, throw_on_53bit_overflow, false,
+    "Throw an exception when integer arithmetic exceeds 53 bits.");
+
 DEFINE_FLAG(bool, trace_intrinsified_natives, false,
     "Report if any of the intrinsified natives are called");
 
@@ -34,6 +37,17 @@
 }
 
 
+// Throw kFiftyThreeBitOverflow if the result of an operation overflows
+// 53 bits.
+static void ThrowExceptionOnOverflow(const Integer& i, const char* msg) {

[siva, 2013/05/23 01:28:22]

The name ThrowExceptionOnOverflow seems like a generic overflow exception, maybe
call it CheckForFiftyThreeOverflow?

Also could this be a static method in the Integer class. That way you could use
it in double.cc, typed_data.cc etc.

[zra, 2013/05/23 15:59:07]

Done.

+  if (i.FitsIn53Bits()) return;
+  const Array& exc_args = Array::Handle(Array::New(1));
+  exc_args.SetAt(0, Object::Handle(String::New(msg)));
+  Exceptions::ThrowByType(Exceptions::kFiftyThreeBitOverflowError, exc_args);
+  return;
+}
+
+
 DEFINE_NATIVE_ENTRY(Integer_bitAndFromInteger, 2) {
   const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
@@ -45,6 +59,9 @@
   }
   const Integer& result =
       Integer::Handle(left.BitOp(Token::kBIT_AND, right));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_bitAndFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -60,6 +77,9 @@
   }
   const Integer& result =
       Integer::Handle(left.BitOp(Token::kBIT_OR, right));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_bitOrFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -75,6 +95,9 @@
   }
   const Integer& result =
       Integer::Handle(left.BitOp(Token::kBIT_XOR, right));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_bitXorFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -90,6 +113,9 @@
   }
   const Integer& result =
       Integer::Handle(left_int.ArithmeticOp(Token::kADD, right_int));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_addFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -105,6 +131,9 @@
   }
   const Integer& result =
       Integer::Handle(left_int.ArithmeticOp(Token::kSUB, right_int));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_subFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -120,6 +149,9 @@
   }
   const Integer& result =
       Integer::Handle(left_int.ArithmeticOp(Token::kMUL, right_int));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_mulFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -132,6 +164,9 @@
   ASSERT(!right_int.IsZero());
   const Integer& result =
       Integer::Handle(left_int.ArithmeticOp(Token::kTRUNCDIV, right_int));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_trucDivFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -151,6 +186,9 @@
   }
   const Integer& result =
       Integer::Handle(left_int.ArithmeticOp(Token::kMOD, right_int));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_moduloFromInteger");
+  }
   return result.AsValidInteger();
 }
 
@@ -193,7 +231,11 @@
       const int64_t int_value = strtoll(cstr, &p_end, 10);
       if (p_end == (cstr + len)) {
         if ((int_value != LLONG_MIN) && (int_value != LLONG_MAX)) {
-          return Integer::New(int_value);
+          const Integer& i = Integer::Handle(Integer::New(int_value));
+          if (FLAG_throw_on_53bit_overflow) {
+            ThrowExceptionOnOverflow(i, "Integer_parse");
+          }
+          return i.AsValidInteger();
         }
       }
     }
@@ -212,7 +254,11 @@
     }
     String& temp = String::Handle();
     temp = String::Concat(Symbols::Dash(), *int_string);
-    return Integer::New(temp);
+    const Integer& i = Integer::Handle(Integer::New(temp));
+    if (FLAG_throw_on_53bit_overflow) {
+      ThrowExceptionOnOverflow(i, "Integer_parse");
+    }
+    return i.AsValidInteger();
   }
 
   const Array& args = Array::Handle(Array::New(1));
@@ -274,6 +320,9 @@
   ASSERT(CheckInteger(value));
   const Integer& result = Integer::Handle(
       ShiftOperationHelper(Token::kSHR, value, amount));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Smi_shrFromInt");
+  }
   return result.AsValidInteger();
 }
 
@@ -290,6 +339,9 @@
   }
   const Integer& result = Integer::Handle(
       ShiftOperationHelper(Token::kSHL, value, amount));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Smi_shlFromInt");
+  }
   return result.AsValidInteger();
 }
 
@@ -313,7 +365,11 @@
     OS::Print("Mint_bitNegate: %s\n", operand.ToCString());
   }
   int64_t result = ~operand.value();
-  return Integer::New(result);
+  const Integer& i = Integer::Handle(Integer::New(result));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(i, "Integer_bitAndFromInteger");
+  }
+  return i.AsValidInteger();

[siva, 2013/05/23 01:28:22]

Ditto question about the need for AsValidInteger.

[zra, 2013/05/23 15:59:07]

Done.

 }
 
 // Bigint natives.