public ValType CheckValueType(Node node, Scope inner, Scope outer)
{
switch (node.GetNodeType())
{
case NodeType.Variable:
VariableNode variableNode = node as VariableNode;
if (!inner.variables.TryGetValue(variableNode.name, out VariableNode val))
{
if (!outer.variables.TryGetValue(variableNode.name, out val))
{
throw new SemanticException(SemanticErrorCode.UndeclaredVariable, "Variable \"" + variableNode.name + "\" is not declared.", node.Line);
}
else
{
variableNode.ValType = val.ValType;
variableNode.LocalIndex = val.LocalIndex;
}
}
else
{
variableNode.ValType = val.ValType;
variableNode.LocalIndex = val.LocalIndex;
}
return(variableNode.ValType);
case NodeType.Assign:
AssignNode assignNode = node as AssignNode;
ValType left = CheckValueType(assignNode.left, inner, outer);
ValType right = CheckValueType(assignNode.right, inner, outer);
if (assignNode.left.ValType != right && !(assignNode.left.ValType == ValType.Double && right == ValType.Int))
{
throw new SemanticException(SemanticErrorCode.IllegalCast, "Cannot cast " + Enum.GetName(typeof(ValType), right) +
" to " + Enum.GetName(typeof(ValType), assignNode.left.ValType) + ".", assignNode.right.Line);
}
if (right == ValType.Int && assignNode.left.ValType == ValType.Double)
{
DoubleCastNode dcn = new DoubleCastNode(assignNode.right.Line);
dcn.content = assignNode.right;
assignNode.right = dcn;
}
assignNode.ValType = left;
return(left);
case NodeType.Int:
return(ValType.Int);
case NodeType.Double:
return(ValType.Double);
case NodeType.Bool:
return(ValType.Bool);
case NodeType.BinaryOp:
BinaryOpNode binaryOpNode = node as BinaryOpNode;
ValType l = CheckValueType(binaryOpNode.left, inner, outer);
ValType r = CheckValueType(binaryOpNode.right, inner, outer);
int v = (int)l * (int)r;
if (binaryOpNode.type == BinaryOpType.BitAnd || binaryOpNode.type == BinaryOpType.BitOr)
{
if (v != 1)
{
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Int value.", node.Line);
}
return(ValType.Int);
}
else
{
if (v > 1 && v < 4)
{
if (l == ValType.Double)
{
DoubleCastNode dcn = new DoubleCastNode(binaryOpNode.right.Line);
dcn.content = binaryOpNode.right;
binaryOpNode.right = dcn;
}
else
{
DoubleCastNode dcn = new DoubleCastNode(binaryOpNode.left.Line);
dcn.content = binaryOpNode.left;
binaryOpNode.left = dcn;
}
binaryOpNode.ValType = ValType.Double;
return(ValType.Double);
}
else if (l == ValType.Bool || r == ValType.Bool)
{
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Int or Double.", binaryOpNode.Line);
}
}
binaryOpNode.ValType = l;
return(l);
case NodeType.LogicOp:
LogicOpNode logicOpNode = node as LogicOpNode;
left = CheckValueType(logicOpNode.left, inner, outer);
right = CheckValueType(logicOpNode.right, inner, outer);
if (left != ValType.Bool)
{
string typeString = Enum.GetName(typeof(ValType), left);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Bool, but got " + typeString + ".", logicOpNode.left.Line);
}
if (right != ValType.Bool)
{
string typeString = Enum.GetName(typeof(ValType), right);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Bool, but got " + typeString + ".", logicOpNode.right.Line);
}
logicOpNode.ValType = ValType.Bool;
return(ValType.Bool);
case NodeType.Comparison:
ComparisonNode comparisonNode = node as ComparisonNode;
left = CheckValueType(comparisonNode.left, inner, outer);
right = CheckValueType(comparisonNode.right, inner, outer);
if (left != right)
{
if (left == ValType.Bool || right == ValType.Bool)
{
throw new SemanticException(SemanticErrorCode.IllegalCast, "Comparison arguments are not the same type.", comparisonNode.Line);
}
else if (left == ValType.Int && right == ValType.Double)
{
DoubleCastNode dcn = new DoubleCastNode(comparisonNode.left.Line);
dcn.content = comparisonNode.left;
comparisonNode.left = dcn;
}
else if (right == ValType.Int && left == ValType.Double)
{
DoubleCastNode dcn = new DoubleCastNode(comparisonNode.right.Line);
dcn.content = comparisonNode.right;
comparisonNode.right = dcn;
}
}
comparisonNode.ValType = ValType.Bool;
return(ValType.Bool);
case NodeType.Parenthesis:
ParenthesisNode parenthesisNode = node as ParenthesisNode;
ValType type = CheckValueType(parenthesisNode.content, inner, outer);
parenthesisNode.ValType = type;
return(type);
case NodeType.IntCast:
IntCastNode intCastNode = node as IntCastNode;
CheckInScope(intCastNode.content, inner, outer);
intCastNode.ValType = ValType.Int;
return(ValType.Int);
case NodeType.DoubleCast:
DoubleCastNode doubleCastNode = node as DoubleCastNode;
CheckInScope(doubleCastNode.content, inner, outer);
doubleCastNode.ValType = ValType.Double;
return(ValType.Double);
case NodeType.Not:
NotNode notNode = node as NotNode;
type = CheckValueType(notNode.content, inner, outer);
if (type != ValType.Bool)
{
string typeString = Enum.GetName(typeof(ValType), type);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Bool, but got " + typeString + ".", notNode.content.Line);
}
notNode.ValType = ValType.Bool;
return(ValType.Bool);
case NodeType.Minus:
MinusNode minusNode = node as MinusNode;
type = CheckValueType(minusNode.content, inner, outer);
if (type == ValType.Bool)
{
string typeString = Enum.GetName(typeof(ValType), type);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Int or Double.", minusNode.content.Line);
}
minusNode.ValType = type;
return(type);
case NodeType.Neg:
NegNode negNode = node as NegNode;
type = CheckValueType(negNode.content, inner, outer);
if (type != ValType.Int)
{
string typeString = Enum.GetName(typeof(ValType), type);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Int, but got " + typeString + ".", negNode.content.Line);
}
negNode.ValType = type;
return(ValType.Int);
}
return(ValType.None);
}
public void CheckInScope(Node node, Scope inner, Scope outer)
{
switch (node.GetNodeType())
{
case NodeType.Block:
Scope newOuter = new Scope(outer);
newOuter.AddScope(inner);
GoDeeperInScope(node as BlockNode, newOuter);
break;
case NodeType.If:
IfNode ifNode = node as IfNode;
ValType type = CheckValueType(ifNode.check, inner, outer);
if (type == ValType.Bool)
{
CheckInScope(ifNode.ifBlock, inner, outer);
if (!(ifNode.elseBlock is null))
{
CheckInScope(ifNode.elseBlock, inner, outer);
}
}
else
{
string typeString = Enum.GetName(typeof(ValType), type);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Bool, but got " + typeString + ".", node.Line);
}
break;
case NodeType.While:
WhileNode whileNode = node as WhileNode;
type = CheckValueType(whileNode.check, inner, outer);
if (type == ValType.Bool)
{
CheckInScope(whileNode.block, inner, outer);
}
else
{
string typeString = Enum.GetName(typeof(ValType), type);
throw new SemanticException(SemanticErrorCode.IllegalCast, "Expected Bool, but got " + typeString + ".", node.Line);
}
break;
case NodeType.Read:
ReadNode readNode = node as ReadNode;
CheckInScope(readNode.target, inner, outer);
break;
case NodeType.Write:
WriteNode writeNode = node as WriteNode;
if (!(writeNode.content is StringNode))
{
CheckInScope(writeNode.content, inner, outer);
}
break;
case NodeType.Variable:
VariableNode variableNode = node as VariableNode;
CheckValueType(variableNode, inner, outer);
break;
case NodeType.Init:
InitNode initNode = node as InitNode;
if (inner.variables.ContainsKey(initNode.variable.name))
{
throw new SemanticException(SemanticErrorCode.VariableAlreadyDeclared, "Variable \"" + initNode.variable.name + "\" already declared in scope", initNode.variable.Line);
}
else
{
inner.variables.Add(initNode.variable.name, initNode.variable);
}
initNode.variable.LocalIndex = locals.Count;
locals.Add(new LocalVariable {
Name = initNode.variable.name, Type = initNode.variable.ValType
});
break;
case NodeType.Assign:
AssignNode assignNode = node as AssignNode;
CheckValueType(assignNode, inner, outer);
break;
case NodeType.BinaryOp:
BinaryOpNode binaryOpNode = node as BinaryOpNode;
CheckValueType(binaryOpNode, inner, outer);
break;
case NodeType.Comparison:
ComparisonNode comparisonNode = node as ComparisonNode;
CheckValueType(comparisonNode, inner, outer);
break;
case NodeType.Parenthesis:
ParenthesisNode parenthesisNode = node as ParenthesisNode;
CheckInScope(parenthesisNode.content, inner, outer);
break;
case NodeType.Int:
case NodeType.Double:
case NodeType.Bool:
case NodeType.String:
break;
case NodeType.LogicOp:
LogicOpNode logicNode = node as LogicOpNode;
CheckValueType(logicNode, inner, outer);
break;
case NodeType.IntCast:
IntCastNode intCastNode = node as IntCastNode;
CheckValueType(intCastNode, inner, outer);
break;
case NodeType.DoubleCast:
DoubleCastNode doubleCastNode = node as DoubleCastNode;
CheckValueType(doubleCastNode, inner, outer);
break;
case NodeType.Not:
NotNode notNode = node as NotNode;
CheckValueType(notNode, inner, outer);
break;
case NodeType.Minus:
MinusNode minusNode = node as MinusNode;
CheckValueType(minusNode, inner, outer);
break;
case NodeType.Neg:
NegNode negNode = node as NegNode;
CheckValueType(negNode, inner, outer);
break;
}
}