public override AstNode Visit(AssignmentExpression node)
{
// Begin the node.
builder.BeginNode(node);
// Get the variable and his value.
Expression variable = node.GetVariable();
Expression value = node.GetValue();
// Get the types.
//IChelaType variableType = variable.GetNodeType();
IChelaType valueType = value.GetNodeType();
IChelaType coercionType = node.GetCoercionType();
// Get the variable data.
Variable variableData = (Variable)variable.GetNodeValue();
// Visit the variable.
variable.Accept(this);
// Duplicate the reference.
DuplicateReference(node, variableData);
// Visit the value.
value.Accept(this);
// Check for delayed coercion
if(node.DelayedCoercion)
{
ConstantValue constant = (ConstantValue) value.GetNodeValue();
uint size = coercionType.GetSize();
if(coercionType.IsUnsigned())
{
// Check unsigned ranges.
ulong cval = constant.GetULongValue();
if(size <= 1 && cval > 0xFFu ||
size <= 2 && cval > 0xFFFFu ||
size <= 4 && cval > 0xFFFFFFFFu)
Error(node, "cannot implicitly convert {0} into a {1}.", cval, coercionType.GetName());
}
else
{
// Check for unsigned constraint.
long cval = constant.GetLongValue();
if(cval < 0)
{
if(coercionType.IsUnsigned())
Error(node, "cannot convert signed {0} into {1}.", cval, coercionType.GetName());
cval = -cval;
}
// Check signed ranges.
if(size <= 1 && cval > 0x7Fu ||
size <= 2 && cval > 0x7FFFu ||
size <= 4 && cval > 0x7FFFFFFFu)
Error(node, "cannot implicitly convert {0} into a {1}.", cval, coercionType.GetName());
}
}
// Cast the value.
if(valueType != coercionType)
Cast(node, value.GetNodeValue(), valueType, coercionType);
// Store the value into the variable.
PerformAssignment(node, variableData);
// Set the node value.
node.SetNodeValue(variableData);
return builder.EndNode();
}
public override AstNode Visit(AssignmentExpression node)
{
// Get the variable and value expression.
Expression variable = node.GetVariable();
Expression value = node.GetValue();
// Visit them.
variable.Accept(this);
value.Accept(this);
// Get their types.
IChelaType variableType = variable.GetNodeType();
IChelaType valueType = value.GetNodeType();
// Set the node type.
node.SetNodeType(variableType);
// The variable must be a reference.
if(!variableType.IsReference())
Error(node, "trying to set something that isn't a reference.");
// Check the variable is not a constant.
variableType = DeReferenceType(variableType);
if(variableType.IsConstant())
Error(node, "cannot modify constants.");
// Check for the read-only constraint.
Variable variableSlot = variable.GetNodeValue() as Variable;
if(variableSlot != null && variableSlot.IsReadOnly())
CheckReadOnlyConstraint(node, variableSlot);
// Set the coercion type.
node.SetCoercionType(variableType);
// Check the type compatibility.
//System.Console.WriteLine("{0}->{1}", valueType, variableType);
if(variableType != valueType &&
Coerce(node, variableType, valueType, value.GetNodeValue()) != variableType)
{
// Delay integer constants casting.
if(valueType.IsConstant())
{
valueType = DeConstType(valueType);
if(valueType.IsInteger() &&
valueType != ChelaType.GetBoolType() &&
valueType != ChelaType.GetCharType())
node.DelayedCoercion = true;
}
if(!node.DelayedCoercion)
Error(value, "cannot implicitly cast from {0} to {1}.",
valueType.GetDisplayName(), variableType.GetDisplayName());
}
return node;
}
