private void VisitWhileStatement(ASTWhileStatementNode whileNode)
{
if (whileNode.Body != null)
{
VisitBodyStatement(whileNode.Body);
}
}
/// <summary>
/// Builds while loop statement
/// </summary>
/// <param name="whileNode">While statement node</param>
private void BuildWhileStatement(ASTWhileStatementNode whileNode)
{
var condition = _emitter.DefineLabel();
var body = _emitter.DefineLabel();
var exitWhile = _emitter.DefineLabel();
//calc condition
_emitter.MarkLabel(condition);
BuildExpression(whileNode.Condition);
_emitter.Box();
if (_emitter.StackPeek() != typeof(bool))
{
_emitter.ToBool();
}
//check condition
_emitter.JumpFalse(exitWhile);
//body
_loopsEnds.Push(exitWhile);
if (whileNode.Body != null)
{
BuildStatement(whileNode.Body);
//jump back
_emitter.Jump(condition);
}
_loopsEnds.Pop();
//while exit
_emitter.MarkLabel(exitWhile);
}
private void CheckWhileStatement(ASTWhileStatementNode whileNode)
{
//check condition type
CheckImplicitCast(whileNode.Condition, typeof(bool));
CheckExpression(whileNode.Condition);
//CheckImplicitCast(whileNode.Condition, typeof(bool));
if (whileNode.Body != null)
{
//check infinity loop or dead code
if (ASTExprHelper.IsValuable(whileNode.Condition))
{
//infinity loop
if (Convert.ToBoolean(ASTExprHelper.GetValue(whileNode.Condition)))
{
_messages.Add(new MessageRecord(
MsgCode.InfinityLoop,
whileNode.Body.SourcePath,
whileNode.Body.StartLine,
whileNode.Body.StartPos
));
}
else //unreachable code
{
_messages.Add(new MessageRecord(
MsgCode.UnreachableCode,
whileNode.Body.SourcePath,
whileNode.Body.StartLine,
whileNode.Body.StartPos
));
}
}
//body check
_inLoop = true;
CheckBody(whileNode.Body);
_inLoop = false;
}
else
{
_messages.Add(new MessageRecord(
MsgCode.EmptyBody,
whileNode.SourcePath,
whileNode.StartLine,
whileNode.StartPos
));
}
}
