/// <summary>
/// Gets the type that results from evaluating this expression.
/// </summary>
public override Type GetResultType(OptimizationInfo optimizationInfo)
{
// The result is either the type of the second operand or the third operand.
var a = this.GetOperand(1).GetResultType(optimizationInfo);
var b = this.GetOperand(2).GetResultType(optimizationInfo);
if (a == b)
{
return(a);
}
if (PrimitiveTypeUtilities.IsNumeric(a) == true && PrimitiveTypeUtilities.IsNumeric(b) == true)
{
return(typeof(double));
}
if (StaticResult != null)
{
// Convert it to a bool:
bool result = TypeConverter.ToBoolean(StaticResult);
if (result)
{
return(a);
}
return(b);
}
// Don't know if it'll be a or b, and they're distinctive types.
return(typeof(object));
}
/// <summary>
/// Generates CIL for the logical operators.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
private void GenerateLogical(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// If either evaluates statically to 0 then we also know the correct return type.
object leftEval = Left.Evaluate();
if (leftEval != null)
{
// RHS only.
bool leftTrue = TypeConverter.ToBoolean(leftEval);
// a && b
// If a is false, don't do anything with b.
// If a is true, emit b.
// a || b
// If a is false, emit b. If it's true, emit a.
if (OperatorType == OperatorType.LogicalAnd && !leftTrue)
{
// Don't evaluate the RHS. Just emit a 'false' if one is needed.
if (optimizationInfo.RootExpression != this)
{
// Emit the false:
generator.LoadBoolean(false);
}
}
else if (OperatorType == OperatorType.LogicalOr && leftTrue)
{
// Emit the left object only.
if (optimizationInfo.RootExpression != this)
{
// Load it:
EmitHelpers.EmitValue(generator, leftEval);
}
}
else if (optimizationInfo.RootExpression == this)
{
// Emitting b (no return type required).
// Right will be the root instead.
optimizationInfo.RootExpression = Right;
Right.GenerateCode(generator, optimizationInfo);
optimizationInfo.RootExpression = this;
}
else
{
// Emitting b (return type required).
// Output required.
Right.GenerateCode(generator, optimizationInfo);
}
return;
}
// Evaluate B, just in case we're doing RHS only:
object rightEval = Right.Evaluate();
// Get the statically-determined types of the left and right operands.
Type leftType = this.Left.GetResultType(optimizationInfo);
Type rightType = rightEval == null?this.Right.GetResultType(optimizationInfo) : rightEval.GetType();
// Load the left-hand side operand.
this.Left.GenerateCode(generator, optimizationInfo);
// Make sure the output type is consistant.
if (leftType != rightType)
{
if (PrimitiveTypeUtilities.IsNumeric(leftType) == true && PrimitiveTypeUtilities.IsNumeric(rightType) == true)
{
EmitConversion.ToNumber(generator, leftType);
leftType = typeof(double);
}
else
{
EmitConversion.ToAny(generator, leftType);
leftType = typeof(object);
}
}
// If this is an OR, we might be using the value currently on the stack if it's true.
// So, duplicate:
if (OperatorType == OperatorType.LogicalOr && optimizationInfo.RootExpression != this)
{
generator.Duplicate();
}
// Convert to a boolean:
EmitConversion.ToBool(generator, leftType);
// If this is an AND, we might be using the value currently on the stack if it's false.
// So, duplicate:
if (OperatorType == OperatorType.LogicalAnd && optimizationInfo.RootExpression != this)
{
generator.Duplicate();
}
// Stack contains:
// OR: "left, (bool)left"
// AND: "(bool)left, (bool)left"
var endOfIf = generator.CreateLabel();
if (this.OperatorType == OperatorType.LogicalAnd)
{
generator.BranchIfFalse(endOfIf);
}
else
{
generator.BranchIfTrue(endOfIf);
}
if (optimizationInfo.RootExpression == this)
{
// Right hand side will now be the root (output is not in use).
optimizationInfo.RootExpression = Right;
Right.GenerateCode(generator, optimizationInfo);
// Restore:
optimizationInfo.RootExpression = this;
}
else
{
// Stack contains "left" which we don't need if we fall through here. Pop it off:
generator.Pop();
// Output is in use.
Right.GenerateCode(generator, optimizationInfo);
// Make sure the output type is consistant.
if (leftType != rightType)
{
if (PrimitiveTypeUtilities.IsNumeric(leftType) == true && PrimitiveTypeUtilities.IsNumeric(rightType) == true)
{
EmitConversion.ToNumber(generator, rightType);
}
else
{
EmitConversion.ToAny(generator, rightType);
}
}
}
// Define the label used above.
generator.DefineLabelPosition(endOfIf);
}
/// <summary>
/// Generates CIL for the relational operators.
/// </summary>
/// <param name="generator"> The generator to output the CIL to. </param>
/// <param name="optimizationInfo"> Information about any optimizations that should be performed. </param>
private void GenerateRelational(ILGenerator generator, OptimizationInfo optimizationInfo)
{
// Get the statically-determined types of the left and right operands.
Type leftType = this.Left.GetResultType(optimizationInfo);
Type rightType = this.Right.GetResultType(optimizationInfo);
// The relational operators compare strings if both of the operands are strings.
if (leftType == typeof(string) && rightType == typeof(string))
{
// Both of the operands are strings.
// Load the left hand side operand onto the stack.
this.Left.GenerateCode(generator, optimizationInfo);
// Load the right hand side operand onto the stack.
this.Right.GenerateCode(generator, optimizationInfo);
if (optimizationInfo.RootExpression == this)
{
generator.Pop();
generator.Pop();
return;
}
// Compare the two strings.
generator.Call(ReflectionHelpers.String_CompareOrdinal);
switch (this.OperatorType)
{
case OperatorType.LessThan:
generator.LoadInt32(0);
generator.CompareLessThan();
break;
case OperatorType.LessThanOrEqual:
generator.LoadInt32(1);
generator.CompareLessThan();
break;
case OperatorType.GreaterThan:
generator.LoadInt32(0);
generator.CompareGreaterThan();
break;
case OperatorType.GreaterThanOrEqual:
generator.LoadInt32(-1);
generator.CompareGreaterThan();
break;
}
}
else if (leftType == typeof(int) && rightType == typeof(int))
{
// Both of the operands are integers.
// Load the left hand side operand onto the stack.
this.Left.GenerateCode(generator, optimizationInfo);
// Load the right hand side operand onto the stack.
this.Right.GenerateCode(generator, optimizationInfo);
if (optimizationInfo.RootExpression == this)
{
generator.Pop();
generator.Pop();
return;
}
// Compare the two numbers.
switch (this.OperatorType)
{
case OperatorType.LessThan:
generator.CompareLessThan();
break;
case OperatorType.GreaterThan:
generator.CompareGreaterThan();
break;
case OperatorType.LessThanOrEqual:
// a <= b <--> (a > b) == false
generator.CompareGreaterThan();
generator.LoadBoolean(false);
generator.CompareEqual();
break;
case OperatorType.GreaterThanOrEqual:
// a >= b <--> (a < b) == false
generator.CompareLessThan();
generator.LoadBoolean(false);
generator.CompareEqual();
break;
}
}
else if (PrimitiveTypeUtilities.IsNumeric(leftType) || PrimitiveTypeUtilities.IsNumeric(rightType))
{
// At least one of the operands is a number.
// Load the left hand side operand onto the stack.
this.Left.GenerateCode(generator, optimizationInfo);
// Convert the operand to a number.
EmitConversion.ToNumber(generator, leftType);
// Load the right hand side operand onto the stack.
this.Right.GenerateCode(generator, optimizationInfo);
if (optimizationInfo.RootExpression == this)
{
generator.Pop();
generator.Pop();
return;
}
// Convert the operand to a number.
EmitConversion.ToNumber(generator, rightType);
// Compare the two numbers.
switch (this.OperatorType)
{
case OperatorType.LessThan:
generator.CompareLessThan();
break;
case OperatorType.GreaterThan:
generator.CompareGreaterThan();
break;
case OperatorType.LessThanOrEqual:
// a <= b <--> (a > b) == false
generator.CompareGreaterThanUnsigned();
generator.LoadBoolean(false);
generator.CompareEqual();
break;
case OperatorType.GreaterThanOrEqual:
// a >= b <--> (a < b) == false
generator.CompareLessThanUnsigned();
generator.LoadBoolean(false);
generator.CompareEqual();
break;
}
}
else
{
// It is unknown whether one of the operands is a string.
// Load the left hand side operand onto the stack.
this.Left.GenerateCode(generator, optimizationInfo);
EmitConversion.ToAny(generator, leftType);
// Load the right hand side operand onto the stack.
this.Right.GenerateCode(generator, optimizationInfo);
if (optimizationInfo.RootExpression == this)
{
generator.Pop();
generator.Pop();
return;
}
EmitConversion.ToAny(generator, rightType);
switch (this.OperatorType)
{
case OperatorType.LessThan:
generator.Call(ReflectionHelpers.TypeComparer_LessThan);
break;
case OperatorType.LessThanOrEqual:
generator.Call(ReflectionHelpers.TypeComparer_LessThanOrEqual);
break;
case OperatorType.GreaterThan:
generator.Call(ReflectionHelpers.TypeComparer_GreaterThan);
break;
case OperatorType.GreaterThanOrEqual:
generator.Call(ReflectionHelpers.TypeComparer_GreaterThanOrEqual);
break;
}
}
}
/// <summary>
/// Gets the type that results from evaluating this expression.
/// </summary>
public override Type GetResultType(OptimizationInfo optimizationInfo)
{
var type = this.OperatorType;
switch (this.OperatorType)
{
// Add
case OperatorType.Add:
{
var lhs = this.Left.GetResultType(optimizationInfo);
var rhs = this.Right.GetResultType(optimizationInfo);
if (lhs == typeof(string) || rhs == typeof(string))
{
return(typeof(ConcatenatedString));
}
if (lhs == typeof(ConcatenatedString) || rhs == typeof(ConcatenatedString))
{
return(typeof(ConcatenatedString));
}
// If the two types are numeric integers, retain the one with the most accuracy.
Type numeric = TypeConverter.MostAccurateInteger(lhs, rhs);
if (numeric != null)
{
return(numeric);
}
if (lhs == typeof(object) || lhs == typeof(Library.ObjectInstance) ||
rhs == typeof(object) || rhs == typeof(Library.ObjectInstance))
{
return(typeof(object));
}
return(typeof(double));
}
// Arithmetic operations.
case OperatorType.Subtract:
case OperatorType.Multiply:
case OperatorType.Divide:
case OperatorType.Modulo:
return(typeof(double));
// Bitwise operations.
case OperatorType.BitwiseAnd:
case OperatorType.BitwiseOr:
case OperatorType.BitwiseXor:
case OperatorType.LeftShift:
case OperatorType.SignedRightShift:
return(typeof(int));
case OperatorType.UnsignedRightShift:
return(typeof(double));
// Relational operations.
case OperatorType.LessThan:
case OperatorType.LessThanOrEqual:
case OperatorType.GreaterThan:
case OperatorType.GreaterThanOrEqual:
return(typeof(bool));
// Equality operations.
case OperatorType.Equal:
case OperatorType.StrictlyEqual:
case OperatorType.NotEqual:
case OperatorType.StrictlyNotEqual:
return(typeof(bool));
// Logical operations.
case OperatorType.LogicalAnd:
{
var lhs = this.Left.GetResultType(optimizationInfo);
var rhs = this.Right.GetResultType(optimizationInfo);
// If lhs is true (regardless of whatever it's type is) then we respond with rhs.
// If it's false, we respond with typeof(bool).
// Try and eval left statically:
object leftEval = Left.Evaluate();
if (leftEval == null)
{
// Can't statically eval it.
// If rhs is a bool then great, we know for sure we're returning a bool.
if (rhs == typeof(bool))
{
return(typeof(bool));
}
// Either a bool or rhs. For now this is an error condition.
optimizationInfo.TypeError(
"Ambiguous type && statement. It returns either a boolean or '" + rhs +
"'. Add ==true to the right hand side to make sure it only returns a boolean."
);
return(typeof(object));
}
if (leftEval != null && TypeConverter.ToBoolean(leftEval))
{
// Ok! We'll be returning rhs no matter what.
return(rhs);
}
// Left eval was false so we'll be returning false.
return(typeof(bool));
}
case OperatorType.LogicalOr:
{
// The result is either the left-hand side or the right-hand side.
var lhs = this.Left.GetResultType(optimizationInfo);
var rhs = this.Right.GetResultType(optimizationInfo);
if (lhs == rhs)
{
return(lhs);
}
if (PrimitiveTypeUtilities.IsNumeric(lhs) && PrimitiveTypeUtilities.IsNumeric(rhs))
{
return(typeof(double));
}
// If either evaluates statically to 0 then we also know the correct return type.
object leftEval = Left.Evaluate();
if (leftEval != null && !TypeConverter.ToBoolean(leftEval))
{
return(rhs);
}
object rightEval = Right.Evaluate();
if (rightEval != null && !TypeConverter.ToBoolean(rightEval))
{
return(lhs);
}
return(typeof(object));
}
// Misc
case OperatorType.InstanceOf:
case OperatorType.In:
return(typeof(bool));
}
throw new NotImplementedException();
}
internal override void ResolveVariables(OptimizationInfo optimizationInfo)
{
if (ResolvedProperty != null || propertyName != null)
{
// Already resolved.
return;
}
// Resolve kids:
base.ResolveVariables(optimizationInfo);
// Right-hand-side can be a property name (a.b)
if (this.OperatorType == OperatorType.MemberAccess)
{
var rhs = this.GetOperand(1) as NameExpression;
if (rhs == null)
{
throw new JavaScriptException(optimizationInfo.Engine, "SyntaxError", "Invalid member access", 1, optimizationInfo.Source.Path, optimizationInfo.FunctionName);
}
propertyName = rhs.Name;
}
// Or a constant indexer (a['b'])
if (this.OperatorType == OperatorType.Index)
{
var rhs = this.GetOperand(1);
if (rhs != null)
{
Type rhsType = rhs.GetResultType(optimizationInfo);
if (rhsType == typeof(string))
{
// Try a literal:
LiteralExpression literalStr = rhs as LiteralExpression;
if (literalStr != null)
{
propertyName = TypeConverter.ToString(literalStr.Value);
// Could actually be numeric, so try that:
if (propertyName != null && Nitrassic.Library.Array.ParseArrayIndex(propertyName) != uint.MaxValue)
{
// Yep, it is!
isArrayIndex = true;
}
}
}
else if (PrimitiveTypeUtilities.IsNumeric(rhsType))
{
// array index (a[0])
isArrayIndex = true;
}
}
}
if (isArrayIndex == true)
{
// Array indexer
// -------------
// xxx = object[index]
// Load the left-hand side and convert to an object instance.
var lhs = this.GetOperand(0);
// Get the type of the LHS (the object being read from):
Type lhsType = lhs.GetResultType(optimizationInfo);
// Get the proto for it:
Nitrassic.Library.Prototype proto = optimizationInfo.Engine.Prototypes.Get(lhsType);
// Does that type have an indexer method on it? (this[uint])
ResolvedProperty = proto.Indexer(typeof(uint));
if (ResolvedProperty == null)
{
// Try [int] instead:
ResolvedProperty = proto.Indexer(typeof(int));
}
}
if (ResolvedProperty == null && propertyName != null)
{
// Load the left-hand side and convert to an object instance.
var lhs = this.GetOperand(0);
Type lhsType = lhs.GetResultType(optimizationInfo);
// Get the prototype:
Nitrassic.Library.Prototype proto = optimizationInfo.Engine.Prototypes.Get(lhsType);
// Get the property:
ResolvedProperty = proto.GetProperty(propertyName);
if (ResolvedProperty == null)
{
// Add it now (as undefined):
ResolvedProperty = proto.AddProperty(propertyName, null, Nitrassic.Library.PropertyAttributes.FullAccess);
}
}
}