public override INode DoResolve(ResolveContext rc)
{
Label lb = rc.DefineLabel(LabelType.IF);
ExitIf = rc.DefineLabel(lb.Name + "_EXIT");
Else = rc.DefineLabel(lb.Name + "_ELSE");
ParentIf = rc.EnclosingIf;
rc.EnclosingIf = this;
rc.CreateNewState();
rc.CurrentGlobalScope |= ResolveScopes.If;
// enter if
Expression = (Expression)Expression.DoResolve(rc);
TrueStatement = (Statement)TrueStatement.DoResolve(rc);
FalseStatement = (Statement)FalseStatement.DoResolve(rc);
if (Expression.IsVoid)
{
ResolveContext.Report.Error(3, Location, "cannot evaluate void type in if statement");
}
rc.RestoreOldState();
// exit current if
rc.EnclosingIf = ParentIf;
return(base.DoResolve(rc));
}
/// <summary>
/// Emit code
/// </summary>
/// <returns>Success or fail</returns>
public override bool Emit(EmitContext ec)
{
if (Expression is IntegralExpression)
{
EmitIfConstant(ec);
}
else
{
// emit expression branchable
ec.EmitComment("if-expression evaluation");
Expression.EmitBranchable(ec, Else, false);
ec.EmitComment("(" + Expression.CommentString() + ") is true");
TrueStatement.Emit(ec);
ec.EmitInstruction(new Jump()
{
DestinationLabel = ExitIf.Name
});
ec.MarkLabel(Else);
ec.EmitComment("Else ");
FalseStatement.Emit(ec);
ec.MarkLabel(ExitIf);
}
return(true);
}