public override void GenerateCode(ILCodeGenerator cg)
{
LValue.LoadVariableInTheStack = false;
LValue.GenerateCode(cg);
LValue.LoadVariableInTheStack = true;
//generamos Expression
Expression.GenerateCode(cg);
if (LValue is LValueIdNode)
{
LValueIdNode id = LValue as LValueIdNode;
ILElementInfo ile = cg.ILContextTable.GetDefinedVarOrFunction(id.VariableName);
if (!Object.Equals(ile.FieldBuilder, null))
{
cg.ILGenerator.Emit(OpCodes.Stsfld, ile.FieldBuilder);
}
else if (!Object.Equals(ile.LocalBuilder, null))
{
cg.ILGenerator.Emit(OpCodes.Stloc, ile.LocalBuilder);
}
}
else if (LValue is ArrayIndexAccessNode)
{
ArrayIndexAccessNode arrayElement = LValue as ArrayIndexAccessNode;
cg.ILGenerator.Emit(OpCodes.Stelem, arrayElement.NodeInfo.Type.ILType);
}
else
{
RecordDotAccessNode recordAccess = (LValue as RecordDotAccessNode);
ILElementInfo ile = cg.ILContextTable.GetDefinedType(recordAccess.RecordName);
FieldInfo fi = ile.TypeBuilder.GetField(recordAccess.ID);
cg.ILGenerator.Emit(OpCodes.Stfld, fi);
}
}
public override void CheckSemantic(SymbolTable symbolTable, List <CompileError> errors)
{
///chequeamos la semántica del LValue
LValue.CheckSemantic(symbolTable, errors);
///chequeamos la semántica de la Expression
Expression.CheckSemantic(symbolTable, errors);
///si LValue o Expression evalúan de error este evalua de error
if (Object.Equals(LValue.NodeInfo, SemanticInfo.SemanticError) ||
Object.Equals(Expression.NodeInfo, SemanticInfo.SemanticError))
{
///el nodo evalúa de error
NodeInfo = SemanticInfo.SemanticError;
return;
}
///si Expression no evaluó de error
if (!Object.Equals(Expression.NodeInfo, SemanticInfo.SemanticError))
{
//Expression debe retornar valor
if (Expression.NodeInfo.BuiltInType.IsCompatibleWith(BuiltInType.Void))
{
errors.Add(new CompileError
{
Line = Expression.Line,
Column = Expression.CharPositionInLine,
ErrorMessage = "Assignation expression must return value",
Kind = ErrorKind.Semantic
});
///el nodo evalúa de error
NodeInfo = SemanticInfo.SemanticError;
}
}
//si LValue no evaluó de error
if (!Object.Equals(LValue.NodeInfo, SemanticInfo.SemanticError))
{
//el tipo de Expresion y del LValue tienen que ser compatibles
if (!LValue.NodeInfo.Type.IsCompatibleWith(Expression.NodeInfo.Type))
{
errors.Add(new CompileError
{
Line = Expression.Line,
Column = Expression.CharPositionInLine,
ErrorMessage = string.Format("Cannot implicitly convert type '{0}' to '{1}'", Expression.NodeInfo.Type.Name, LValue.NodeInfo.Type.Name),
Kind = ErrorKind.Semantic
});
///el nodo evalúa de error
NodeInfo = SemanticInfo.SemanticError;
}
///si es solamente un id
if (LValue is LValueIdNode)
{
SemanticInfo variable;
LValueIdNode lvalueId = LValue as LValueIdNode;
if (symbolTable.GetDefinedVariableDeep(lvalueId.VariableName, out variable) && variable.IsReadOnly)
{
//no podemos modificar una variable readonly(en nuestro caso la de un for)
errors.Add(new CompileError
{
Line = LValue.Line,
Column = LValue.CharPositionInLine,
ErrorMessage = "A readonly field cannot be assigned to",
Kind = ErrorKind.Semantic
});
///el nodo evalúa de error
NodeInfo = SemanticInfo.SemanticError;
}
}
}
///el lvalue solo puede ser una variable, el campo de un record o el elemento de un array
if (!IsLValueAssignable())
{
errors.Add(new CompileError
{
Line = LValue.Line,
Column = LValue.CharPositionInLine,
ErrorMessage = "The left-hand side of an assignment must be a variable, field or indexer",
Kind = ErrorKind.Semantic
});
///el nodo evalúa de error
NodeInfo = SemanticInfo.SemanticError;
}
///seteamos los campos necesarios
if (!Object.Equals(NodeInfo, SemanticInfo.SemanticError))
{
NodeInfo.Type = SemanticInfo.Void;
NodeInfo.BuiltInType = BuiltInType.Void;
NodeInfo.ILType = Expression.NodeInfo.ILType;
}
}