private JSBinaryOperatorExpression MakeUnaryMutation (
JSExpression expressionToMutate, JSBinaryOperator mutationOperator,
TypeReference type
) {
var newValue = new JSBinaryOperatorExpression(
mutationOperator, expressionToMutate, JSLiteral.New(1),
type
);
var assignment = new JSBinaryOperatorExpression(
JSOperator.Assignment,
MakeLhsForAssignment(expressionToMutate), newValue, type
);
return assignment;
}
public static JSBinaryOperatorExpression MakeUnaryMutation (
JSExpression expressionToMutate, JSBinaryOperator mutationOperator,
TypeReference type, TypeSystem typeSystem
) {
var newValue = new JSBinaryOperatorExpression(
mutationOperator, expressionToMutate, JSLiteral.New(1),
type
);
var assignment = new JSBinaryOperatorExpression(
JSOperator.Assignment,
MakeLhsForAssignment(expressionToMutate), newValue, type
);
assignment = ConvertReadExpressionToWriteExpression(assignment, typeSystem);
return assignment;
}
protected JSExpression Translate_BinaryOp(ILExpression node, JSBinaryOperator op)
{
// Detect attempts to perform pointer arithmetic
if (IsIgnoredType(node.Arguments[0].ExpectedType) ||
IsIgnoredType(node.Arguments[1].ExpectedType) ||
IsIgnoredType(node.Arguments[0].InferredType) ||
IsIgnoredType(node.Arguments[1].InferredType)
) {
return new JSUntranslatableExpression(node);
}
// Detect attempts to perform pointer arithmetic on a local variable.
// (ldloca produces a reference, not a pointer, so the previous check won't catch this.)
if ((node.Arguments[0].Code == ILCode.Ldloca) &&
!(op is JSAssignmentOperator))
return new JSUntranslatableExpression(node);
var lhs = TranslateNode(node.Arguments[0]);
var rhs = TranslateNode(node.Arguments[1]);
var boeLeft = lhs as JSBinaryOperatorExpression;
if (
(op is JSAssignmentOperator) &&
(boeLeft != null) && !(boeLeft.Operator is JSAssignmentOperator)
)
return new JSUntranslatableExpression(node);
return new JSBinaryOperatorExpression(
op, lhs, rhs, node.ExpectedType ?? node.InferredType
);
}
protected JSExpression Translate_ComparisonOperator(ILExpression node, JSBinaryOperator op)
{
if (
(node.Arguments[0].ExpectedType.FullName == "System.Boolean") &&
(node.Arguments[1].ExpectedType.FullName == "System.Boolean") &&
(node.Arguments[1].Code.ToString().Contains("Ldc_"))
) {
// Comparison against boolean constant
bool comparand = Convert.ToInt64(node.Arguments[1].Operand) != 0;
bool checkEquality = (op == JSOperator.Equal);
if (comparand != checkEquality)
return new JSUnaryOperatorExpression(
JSOperator.LogicalNot, TranslateNode(node.Arguments[0])
);
else
return TranslateNode(node.Arguments[0]);
} else if (
(!node.Arguments[0].ExpectedType.IsValueType) &&
(!node.Arguments[1].ExpectedType.IsValueType) &&
(node.Arguments[0].ExpectedType == node.Arguments[1].ExpectedType) &&
(node.Arguments[0].Code == ILCode.Isinst)
) {
// The C# expression 'x is y' translates into roughly '(x is y) > null' in IL,
// because there's no IL opcode for != and the IL isinst opcode returns object, not bool
var value = TranslateNode(node.Arguments[0].Arguments[0]);
var nullLiteral = TranslateNode(node.Arguments[1]) as JSNullLiteral;
var targetType = (TypeReference)node.Arguments[0].Operand;
var targetInfo = TypeInfo.Get(targetType);
JSExpression checkTypeResult;
if ((targetInfo != null) && targetInfo.IsIgnored)
checkTypeResult = JSLiteral.New(false);
else
checkTypeResult = JSIL.CheckType(
value, targetType
);
if (nullLiteral != null) {
if (
(op == JSOperator.Equal) ||
(op == JSOperator.LessThanOrEqual) ||
(op == JSOperator.LessThan)
) {
return new JSUnaryOperatorExpression(
JSOperator.LogicalNot, checkTypeResult, TypeSystem.Boolean
);
} else if (
(op == JSOperator.GreaterThan)
) {
return checkTypeResult;
} else {
return new JSUntranslatableExpression(node);
}
}
}
return Translate_BinaryOp(node, op);
}
private string GetVerb(JSBinaryOperator op)
{
switch (op.Token)
{
case "+": return "op_Addition";
case "-": return "op_Subtraction";
case "/": return "op_Division";
case "*": return "op_Multiplication";
case "%": return "op_Modulus";
case "|": return "op_BitwiseOr";
case "^": return "op_ExclusiveOr";
case "&": return "op_BitwiseAnd";
case "<<": return "op_LeftShift";
case ">>":
case ">>>":
return "op_RightShift";
case "===": return "op_Equality";
case "!==": return "op_Inequality";
case "<": return "op_LessThan";
case "<=": return "op_LessThanOrEqual";
case ">": return "op_GreaterThan";
case ">=": return "op_GreaterThanOrEqual";
default:
return null;
}
}
private JSBinaryOperatorExpression MakeUnaryMutation(
JSExpression expressionToMutate, JSBinaryOperator mutationOperator,
TypeReference type
)
{
var newValue = new JSBinaryOperatorExpression(
mutationOperator, expressionToMutate, JSLiteral.New(1),
TypeSystem.Int32
);
var assignment = new JSBinaryOperatorExpression(
JSOperator.Assignment,
expressionToMutate, JSCastExpression.New(
newValue, type, TypeSystem, true
), type
);
return assignment;
}