/// <summary>
/// Gets expression representing cost of argument binding operation.
/// The expression can be constant.
/// </summary>
public virtual Expression BindCostOf(int srcarg, Type ptype, bool ismandatory, bool ignorecost)
{
var key = new TmpVarKey()
{
Priority = 100, ArgIndex = srcarg, TargetTypeOpt = ptype, Prefix = "costOf" + (ismandatory ? "" : "Opt")
};
// lookup cache
TmpVarValue value;
if (!_tmpvars.TryGetValue(key, out value))
{
// bind cost expression
value = new TmpVarValue();
var expr_cost = ignorecost ? Expression.Constant(ConversionCost.Pass) : ConvertExpression.BindCost(BindArgument(srcarg), ptype);
if (expr_cost is ConstantExpression)
{
value.Expression = expr_cost;
}
else
{
value.TrueInitializer = expr_cost;
value.FalseInitializer = Expression.Constant(ismandatory ? ConversionCost.MissingArgs : ConversionCost.DefaultValue);
value.Expression = Expression.Variable(typeof(ConversionCost), key.VariableName);
}
_tmpvars[key] = value;
}
//
return(value.Expression);
}
/// <summary>
/// Gets expression resulting in <see cref="ConversionCost.Pass"/> or <see cref="ConversionCost.TooManyArgs"/> based on actual arguments count.
/// </summary>
public virtual Expression BindCostOfTooManyArgs(int expectedargs)
{
var key = new TmpVarKey()
{
Priority = 100, ArgIndex = expectedargs, Prefix = "istoomany"
};
// lookup cache
TmpVarValue value;
if (!_tmpvars.TryGetValue(key, out value))
{
// bind cost expression
value = new TmpVarValue();
var expr_argc = BindArgsCount();
if (expr_argc is ConstantExpression)
{
var argc = (int)((ConstantExpression)expr_argc).Value;
value.Expression = Expression.Constant((argc > expectedargs) ? ConversionCost.TooManyArgs : ConversionCost.Pass);
}
else
{
// istoomanyX = TooManyArgs; in case we endup in this condition
value.TrueInitializer = Expression.Constant(ConversionCost.TooManyArgs);
value.FalseInitializer = Expression.Constant(ConversionCost.Pass);
value.Expression = Expression.Variable(typeof(ConversionCost), key.VariableName);
}
_tmpvars[key] = value;
}
//
return(value.Expression);
}
public override Expression BindArgument(int srcarg, ParameterInfo targetparam = null)
{
Debug.Assert(srcarg >= 0);
// cache the argument value
var key = new TmpVarKey()
{
Priority = 0 /*first*/, ArgIndex = srcarg, Prefix = "arg"
};
TmpVarValue value;
if (!_tmpvars.TryGetValue(key, out value))
{
value = new TmpVarValue();
value.TrueInitializer = Expression.ArrayIndex(_argsarray, Expression.Constant(srcarg));
value.FalseInitializer = ConvertExpression.BindDefault(value.TrueInitializer.Type); // ~ default(_argsarray.Type.GetElementType())
value.Expression = Expression.Variable(value.TrueInitializer.Type, "arg_" + srcarg);
//
_tmpvars[key] = value;
}
if (targetparam != null)
{
// create specialized variable with default value
if (targetparam.HasDefaultValue)
{
var @default = targetparam.DefaultValue;
var defaultValueExpr = Expression.Constant(@default);
var defaultValueStr = (@default != null) ? @default.ToString() : "NULL";
//
var key2 = new TmpVarKey()
{
Priority = 1 /*after key*/, ArgIndex = srcarg, Prefix = "arg(" + defaultValueStr + ")"
};
TmpVarValue value2;
if (!_tmpvars.TryGetValue(key2, out value2))
{
value2 = new TmpVarValue();
value2.TrueInitializer = ConvertExpression.Bind(value.Expression, targetparam.ParameterType, _ctx); // reuse the value already obtained from argv
value2.FalseInitializer = ConvertExpression.Bind(defaultValueExpr, value2.TrueInitializer.Type, _ctx); // ~ default(targetparam)
value2.Expression = Expression.Variable(value2.TrueInitializer.Type, "arg_" + srcarg + "_" + defaultValueStr);
//
_tmpvars[key2] = value2;
}
return(value2.Expression); // already converted to targetparam.ParameterType
}
}
return((targetparam == null)
? value.Expression
: ConvertExpression.Bind(value.Expression, targetparam.ParameterType, _ctx));
}
public override Expression BindArgument(int srcarg, ParameterInfo targetparam = null)
{
Debug.Assert(srcarg >= 0);
// cache the argument value
var key = new TmpVarKey()
{
Priority = 0 /*first*/, ArgIndex = srcarg, Prefix = "arg"
};
TmpVarValue value;
if (!_tmpvars.TryGetValue(key, out value))
{
value = new TmpVarValue();
value.TrueInitializer = Expression.ArrayIndex(_argsarray, Expression.Constant(srcarg));
value.FalseInitializer = ConvertExpression.BindDefault(value.TrueInitializer.Type); // ~ default(_argsarray.Type.GetElementType())
value.Expression = Expression.Variable(value.TrueInitializer.Type, "arg_" + srcarg);
//
_tmpvars[key] = value;
}
if (targetparam != null)
{
DefaultValueAttribute defaultValueAttr = null;
// create specialized variable with default value
if (targetparam.HasDefaultValue || (defaultValueAttr = targetparam.GetCustomAttribute <DefaultValueAttribute>()) != null)
{
Debug.Assert(!targetparam.ParameterType.IsByRef); // parameter with a default value cannot be byref (at least we don't expect it)
// just for debugging purposes:
var defaultValueStr = defaultValueAttr != null
? defaultValueAttr.FieldName
: targetparam.DefaultValue?.ToString() ?? "NULL";
// the default value expression
var defaultValueExpr = defaultValueAttr != null
? BindDefaultValue(targetparam.Member.DeclaringType, defaultValueAttr)
: Expression.Constant(targetparam.DefaultValue);
//
var key2 = new TmpVarKey()
{
Priority = 1 /*after key*/, ArgIndex = srcarg, Prefix = "default(" + defaultValueStr + ")"
};
TmpVarValue value2;
if (!_tmpvars.TryGetValue(key2, out value2))
{
value2 = new TmpVarValue();
value2.TrueInitializer = ConvertExpression.Bind(value.Expression, targetparam.ParameterType, _ctx); // reuse the value already obtained from argv
value2.FalseInitializer = ConvertExpression.Bind(defaultValueExpr, value2.TrueInitializer.Type, _ctx); // ~ default(targetparam)
value2.Expression = Expression.Variable(value2.TrueInitializer.Type, "default_" + srcarg + "_" + defaultValueStr);
//
_tmpvars[key2] = value2;
}
return(value2.Expression); // already converted to targetparam.ParameterType
}
}
if (targetparam == null)
{
return(value.Expression);
}
else
{
var ptype = targetparam.ParameterType;
// TODO: ptype.IsByRef -> implement write-back after the invocation
if (ptype.IsByRef)
{
ptype = ptype.GetElementType(); // LINQ will create a local variable for it implicitly
}
return(ConvertExpression.Bind(value.Expression, ptype, _ctx));
}
}
