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

runtime/lib/integers.cc

 // 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.
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/symbols.h"
 
 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");
 
 // Smi natives.
 
 // Returns false if integer is in wrong representation, e.g., as is a Bigint
 // when it could have been a Smi.
 static bool CheckInteger(const Integer& i) {
   if (i.IsBigint()) {
     const Bigint& bigint = Bigint::Cast(i);
     return !BigintOperations::FitsIntoSmi(bigint) &&
         !BigintOperations::FitsIntoInt64(bigint);
   }
   if (i.IsMint()) {
     const Mint& mint = Mint::Cast(i);
     return !Smi::IsValid64(mint.value());
   }
   return true;
 }
 
 
+// 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));
   ASSERT(CheckInteger(right));
   ASSERT(CheckInteger(left));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_bitAndFromInteger %s & %s\n",
         right.ToCString(), left.ToCString());
   }
   const Integer& result =
       Integer::Handle(left.BitOp(Token::kBIT_AND, right));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_bitAndFromInteger");
+  }
   return result.AsValidInteger();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_bitOrFromInteger, 2) {
   const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right));
   ASSERT(CheckInteger(left));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_bitOrFromInteger %s | %s\n",
         left.ToCString(), right.ToCString());
   }
   const Integer& result =
       Integer::Handle(left.BitOp(Token::kBIT_OR, right));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_bitOrFromInteger");
+  }
   return result.AsValidInteger();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_bitXorFromInteger, 2) {
   const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right));
   ASSERT(CheckInteger(left));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_bitXorFromInteger %s ^ %s\n",
         left.ToCString(), right.ToCString());
   }
   const Integer& result =
       Integer::Handle(left.BitOp(Token::kBIT_XOR, right));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Integer_bitXorFromInteger");
+  }
   return result.AsValidInteger();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_addFromInteger, 2) {
   const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right_int));
   ASSERT(CheckInteger(left_int));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_addFromInteger %s + %s\n",
         left_int.ToCString(), right_int.ToCString());
   }
   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();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_subFromInteger, 2) {
   const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right_int));
   ASSERT(CheckInteger(left_int));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_subFromInteger %s - %s\n",
         left_int.ToCString(), right_int.ToCString());
   }
   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();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_mulFromInteger, 2) {
   const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right_int));
   ASSERT(CheckInteger(left_int));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_mulFromInteger %s * %s\n",
         left_int.ToCString(), right_int.ToCString());
   }
   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();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_truncDivFromInteger, 2) {
   const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right_int));
   ASSERT(CheckInteger(left_int));
   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();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_moduloFromInteger, 2) {
   const Integer& right_int = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left_int, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right_int));
   ASSERT(CheckInteger(right_int));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Integer_moduloFromInteger %s mod %s\n",
         left_int.ToCString(), right_int.ToCString());
   }
   if (right_int.IsZero()) {
     // Should have been caught before calling into runtime.
     UNIMPLEMENTED();
   }
   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();
 }
 
 
 DEFINE_NATIVE_ENTRY(Integer_greaterThanFromInteger, 2) {
   const Integer& right = Integer::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, left, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(right));
   ASSERT(CheckInteger(left));
   if (FLAG_trace_intrinsified_natives) {
@@ skipping 22 matching lines @@
   if (value.IsOneByteString()) {
     // Quick conversion for unpadded integers in strings.
     const intptr_t len = value.Length();
     if (len > 0) {
       const char* cstr = value.ToCString();
       ASSERT(cstr != NULL);
       char* p_end = NULL;
       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();
         }
       }
     }
   }
 
   Scanner scanner(value, Symbols::Empty());
   const Scanner::GrowableTokenStream& tokens = scanner.GetStream();
   String* int_string;
   bool is_positive;
   if (Scanner::IsValidLiteral(tokens,
                              Token::kINTEGER,
                              &is_positive,
                              &int_string)) {
     if (is_positive) {
       return Integer::New(*int_string);
     }
     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));
   args.SetAt(0, value);
   Exceptions::ThrowByType(Exceptions::kFormat, args);
   return Object::null();
 }
 
 
 static RawInteger* ShiftOperationHelper(Token::Kind kind,
@@ skipping 41 matching lines @@
 }
 
 
 DEFINE_NATIVE_ENTRY(Smi_shrFromInt, 2) {
   const Smi& amount = Smi::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, value, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(amount));
   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();
 }
 
 
 
 DEFINE_NATIVE_ENTRY(Smi_shlFromInt, 2) {
   const Smi& amount = Smi::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, value, arguments->NativeArgAt(1));
   ASSERT(CheckInteger(amount));
   ASSERT(CheckInteger(value));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Smi_shlFromInt: %s << %s\n",
         value.ToCString(), amount.ToCString());
   }
   const Integer& result = Integer::Handle(
       ShiftOperationHelper(Token::kSHL, value, amount));
+  if (FLAG_throw_on_53bit_overflow) {
+    ThrowExceptionOnOverflow(result, "Smi_shlFromInt");
+  }
   return result.AsValidInteger();
 }
 
 
 DEFINE_NATIVE_ENTRY(Smi_bitNegate, 1) {
   const Smi& operand = Smi::CheckedHandle(arguments->NativeArgAt(0));
   if (FLAG_trace_intrinsified_natives) {
     OS::Print("Smi_bitNegate: %s\n", operand.ToCString());
   }
   intptr_t result = ~operand.Value();
   ASSERT(Smi::IsValid(result));
   return Smi::New(result);
 }
 
 // Mint natives.
 
 DEFINE_NATIVE_ENTRY(Mint_bitNegate, 1) {
   const Mint& operand = Mint::CheckedHandle(arguments->NativeArgAt(0));
   ASSERT(CheckInteger(operand));
   if (FLAG_trace_intrinsified_natives) {
     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.
 
 DEFINE_NATIVE_ENTRY(Bigint_bitNegate, 1) {
   const Bigint& value = Bigint::CheckedHandle(arguments->NativeArgAt(0));
   const Bigint& result = Bigint::Handle(BigintOperations::BitNot(value));
   ASSERT(CheckInteger(value));
   ASSERT(CheckInteger(result));
   return result.AsValidInteger();
 }
 
 }  // namespace dart