public void VisitNode(SelectionStatement node)
{
Console.Write("<" + node.ClassName() + ">: ");
Console.ForegroundColor = ConsoleColor.Green;
Console.Write("IF");
Console.ResetColor();
PrintAttribute(node);
}
private void VisitNode(SelectionStatement node)
{
AbstractNode ifExp = node.Child;
AbstractNode thanStmt = ifExp.Sib;
AbstractNode elseStmt = thanStmt.Sib; // may be null
ifExp.Accept(this);
++_ifCount;
File.WriteLine("brfalse.s {0}{1}", IF_FALSE, _ifCount);
thanStmt.Accept(this);
File.WriteLine("br.s {0}{1}", IF_END, _ifCount);
File.WriteLine(IF_FALSE + _ifCount + ":");
elseStmt.Accept(this);
File.WriteLine(IF_END + _ifCount + ":");
}
private void VisitNode(SelectionStatement node)
{
AbstractNode ifExp = node.Child;
AbstractNode thanStmt = ifExp.Sib;
AbstractNode elseStmt = thanStmt.Sib; // may be null
SelectionStatementDescriptor ssDesc =
new SelectionStatementDescriptor();
String errMsg = "";
// if expression
ifExp.Accept(this);
ssDesc.IfDescriptor = ifExp.TypeDescriptor;
PrimitiveTypeBooleanDescriptor ifBoolDesc =
ifExp.TypeDescriptor as PrimitiveTypeBooleanDescriptor;
if (ifBoolDesc == null)
{
ifExp.TypeDescriptor = new ErrorDescriptor("If statement " +
"does not evaluate to a Boolean expression. (Has type: " +
ifExp.TypeDescriptor.GetType().Name + ")");
}
// than statement
thanStmt.Accept(this);
thanStmt.TypeDescriptor = thanStmt.Child.TypeDescriptor;
ssDesc.ThanDescriptor = thanStmt.TypeDescriptor;
if (!IsCompatibleStatement(thanStmt.TypeDescriptor))
{
if (errMsg.Length > 0)
{
errMsg += "\n";
}
errMsg += "Non-compatible THAN statement type: " +
thanStmt.TypeDescriptor.GetType().Name;
}
// else statement
if (elseStmt != null)
{
elseStmt.Accept(this);
ssDesc.HasElseStmt = true;
elseStmt.TypeDescriptor = elseStmt.Child.TypeDescriptor;
ssDesc.ElseDescriptor = elseStmt.TypeDescriptor;
if (!IsCompatibleStatement(elseStmt.TypeDescriptor))
{
if (errMsg.Length > 0)
{
errMsg += "\n";
}
errMsg += "Non-compatible ELSE statement type: " +
elseStmt.TypeDescriptor.GetType().Name;
}
}
else
{
ssDesc.HasElseStmt = false;
}
// if any components have errors, propogate them up the tree
if (ifExp.TypeDescriptor is ErrorDescriptor ||
thanStmt.TypeDescriptor is ErrorDescriptor ||
elseStmt?.TypeDescriptor is ErrorDescriptor)
{
// creates an error containing any and all errors lower in tree
if (ifExp.TypeDescriptor is ErrorDescriptor)
{
ssDesc.TypeDescriptor = ifExp.TypeDescriptor;
if (thanStmt.TypeDescriptor is ErrorDescriptor)
{
((ErrorDescriptor)ssDesc.TypeDescriptor).CombineErrors
((ErrorDescriptor)thanStmt.TypeDescriptor);
}
if (elseStmt?.TypeDescriptor is ErrorDescriptor)
{
((ErrorDescriptor)ssDesc.TypeDescriptor).CombineErrors
((ErrorDescriptor)elseStmt.TypeDescriptor);
}
}
else if (thanStmt.TypeDescriptor is ErrorDescriptor)
{
ssDesc.TypeDescriptor = thanStmt.TypeDescriptor;
if (elseStmt?.TypeDescriptor is ErrorDescriptor)
{
((ErrorDescriptor)ssDesc.TypeDescriptor).CombineErrors
((ErrorDescriptor)elseStmt.TypeDescriptor);
}
}
else
{
ssDesc.TypeDescriptor = elseStmt.TypeDescriptor;
}
}
// if IF/THAN/ELSE was incompatible, create new error
else if (errMsg.Length > 0)
{
ssDesc.TypeDescriptor = new ErrorDescriptor(errMsg);
}
// otherwise assign evaluated boolean to selection statement desc
else
{
ssDesc.TypeDescriptor = ifExp.TypeDescriptor;
}
node.TypeDescriptor = ssDesc;
}
private void VisitNode(SelectionStatement node)
{
node.Accept(SemanticsVisitor);
}
