private IfStmt ParseIfStatement()
{
Match(TokenType.KwIf);
IfStmt statement = new IfStmt(AcceptedToken);
statement.TestExpr = ParseExpression();
Match(TokenType.KwThen);
statement.TrueStatement = ParseStatement();
if (Accept(TokenType.KwElse))
{
statement.FalseStatement = ParseStatement();
}
return(statement);
}
private void Visit(IfStmt ifStmt)
{
Visit((dynamic)ifStmt.TestExpr);
TypeInfo testType = TypeStack.Pop();
if (IsNotVoid(testType) && testType.BasicType != ExprType.Bool)
{
AddError("If test expression has to be of type Bool", ifStmt);
}
Visit((dynamic)ifStmt.TrueStatement);
if (ifStmt.FalseStatement != null)
{
Visit((dynamic)ifStmt.FalseStatement);
}
}
private void Visit(IfStmt ifStmt)
{
var il = CurrentMethodIL;
var falseLbl = il.DefineLabel();
var doneLbl = il.DefineLabel();
Visit((dynamic)ifStmt.TestExpr);
il.Emit(OpCodes.Brfalse, falseLbl);
Visit((dynamic)ifStmt.TrueStatement);
il.Emit(OpCodes.Br, doneLbl);
il.MarkLabel(falseLbl);
if (ifStmt.FalseStatement != null)
{
Visit((dynamic)ifStmt.FalseStatement);
}
else
{
il.Emit(OpCodes.Nop);
}
il.MarkLabel(doneLbl);
}