/// <summary>
/// Emits code for comparing a nullable
/// </summary>
private void compileNullable(Context ctx, NodeBase nullValue, NodeBase otherValue)
{
var gen = ctx.CurrentILGenerator;
var nullType = nullValue.GetExpressionType(ctx);
var otherType = otherValue.GetExpressionType(ctx);
var otherNull = otherType.IsNullableType();
var getValOrDefault = nullType.GetMethod("GetValueOrDefault", Type.EmptyTypes);
var hasValueGetter = nullType.GetProperty("HasValue").GetGetMethod();
var falseLabel = gen.DefineLabel();
var endLabel = gen.DefineLabel();
LocalName nullVar, otherVar = null;
nullVar = ctx.CurrentScope.DeclareImplicitName(ctx, nullType, true);
if (otherNull)
otherVar = ctx.CurrentScope.DeclareImplicitName(ctx, otherType, true);
// if (otherNull)
// {
// otherVar = ctx.CurrentScope.DeclareImplicitName(ctx, otherType, true);
//
// var code = Expr.Block(
// Expr.Let(nullVar, nullValue),
// Expr.Let(otherVar, otherValue),
// Expr.Binary(
// Kind == ComparisonOperatorKind.Equals ? BooleanOperatorKind.And : BooleanOperatorKind.Or,
// Expr.Compare(
// Kind,
// Expr.Invoke(Expr.GetIdentifier(nullVar), "GetValueOrDefault"),
// Expr.Invoke(Expr.GetIdentifier(otherVar), "GetValueOrDefault")
// ),
// Expr.Compare(
// Kind,
// Expr.Invoke(Expr.GetIdentifier(nullVar), "get_HasValue"),
// Expr.Invoke(Expr.GetIdentifier(otherVar), "get_HasValue")
// )
// )
// );
//
// code.Compile(ctx, true);
// }
// else
// {
// var code = Expr.Block(
// Expr.Let(nullVar, nullValue),
// Expr.Binary(
// Kind == ComparisonOperatorKind.Equals ? BooleanOperatorKind.And : BooleanOperatorKind.Or,
// Expr.Compare(
// Kind,
// Expr.Invoke(Expr.GetIdentifier(nullVar), "GetValueOrDefault"),
// Expr.Cast(otherValue, Nullable.GetUnderlyingType(nullType))
// ),
// Expr.Invoke(Expr.GetIdentifier(nullVar), "get_HasValue")
// )
// );
//
// code.Compile(ctx, true);
// }
// $tmp = nullValue
nullValue.Compile(ctx, true);
gen.EmitSaveLocal(nullVar);
if (otherNull)
{
// $tmp2 = otherValue
otherValue.Compile(ctx, true);
gen.EmitSaveLocal(otherVar);
}
// $tmp == $tmp2
gen.EmitLoadLocal(nullVar, true);
gen.EmitCall(getValOrDefault);
if (otherNull)
{
gen.EmitLoadLocal(otherVar, true);
gen.EmitCall(getValOrDefault);
}
else
{
otherValue.Compile(ctx, true);
}
gen.EmitBranchNotEquals(falseLabel);
// otherwise, compare HasValues
gen.EmitLoadLocal(nullVar, true);
gen.EmitCall(hasValueGetter);
if (otherNull)
{
gen.EmitLoadLocal(otherVar, true);
gen.EmitCall(hasValueGetter);
gen.EmitCompareEqual();
}
if(Kind == ComparisonOperatorKind.NotEquals)
emitInversion(gen);
gen.EmitJump(endLabel);
gen.MarkLabel(falseLabel);
gen.EmitConstant(false);
gen.MarkLabel(endLabel);
gen.EmitNop();
}
private void resolveGetMember(Context ctx, GetMemberNode node)
{
m_InvocationSource = node.Expression;
var type = m_InvocationSource != null
? m_InvocationSource.GetExpressionType(ctx)
: ctx.ResolveType(node.StaticType);
SafeModeCheckType(ctx, type);
if (node.TypeHints.Any())
m_TypeHints = node.TypeHints.Select(x => x.FullSignature == "_" ? null : ctx.ResolveType(x)).ToArray();
try
{
// resolve a normal method
try
{
m_Method = ctx.ResolveMethod(type, node.MemberName, m_ArgTypes, m_TypeHints);
if (m_Method.IsStatic)
m_InvocationSource = null;
return;
}
catch (KeyNotFoundException)
{
if (m_InvocationSource == null)
throw;
}
// resolve a callable field
try
{
ctx.ResolveField(type, node.MemberName);
resolveExpression(ctx, node);
return;
}
catch (KeyNotFoundException) { }
// resolve a callable field
try
{
ctx.ResolveProperty(type, node.MemberName);
resolveExpression(ctx, node);
return;
}
catch (KeyNotFoundException) { }
// resolve a local function that is implicitly used as an extension method
// move invocation source to arguments
if (Arguments[0] is UnitNode)
Arguments[0] = m_InvocationSource;
else
Arguments.Insert(0, m_InvocationSource);
var oldArgTypes = m_ArgTypes;
m_ArgTypes = Arguments.Select(a => a.GetExpressionType(ctx)).ToArray();
m_InvocationSource = null;
try
{
m_Method = ctx.ResolveMethod(ctx.MainType.TypeInfo, node.MemberName, m_ArgTypes);
}
catch (KeyNotFoundException)
{
// resolve a declared extension method
// most time-consuming operation, therefore is last checked
if(ctx.Options.AllowExtensionMethods)
m_Method = ctx.ResolveExtensionMethod(type, node.MemberName, oldArgTypes, m_TypeHints);
}
}
catch (AmbiguousMatchException)
{
Error(CompilerMessages.TypeMethodInvocationAmbiguous, type, node.MemberName);
}
catch (KeyNotFoundException)
{
var msg = node.StaticType != null
? CompilerMessages.TypeStaticMethodNotFound
: CompilerMessages.TypeMethodNotFound;
Error(msg, type, node.MemberName);
}
}
/// <summary>
/// Checks if the nullable expression is null.
/// </summary>
private void compileHasValue(Context ctx, NodeBase nullValue)
{
var gen = ctx.CurrentILGenerator;
var nullType = nullValue.GetExpressionType(ctx);
var nullVar = ctx.CurrentScope.DeclareImplicitName(ctx, nullType, true);
var hasValueGetter = nullType.GetProperty("HasValue").GetGetMethod();
nullValue.Compile(ctx, true);
gen.EmitSaveLocal(nullVar);
gen.EmitLoadLocal(nullVar, true);
gen.EmitCall(hasValueGetter);
// sic! get_HasValue == true when value != null
if(Kind == ComparisonOperatorKind.Equals)
emitInversion(gen);
}
private void resolveExpression(Context ctx, NodeBase node)
{
var exprType = node.GetExpressionType(ctx);
if (!exprType.IsCallableType())
Error(CompilerMessages.TypeNotCallable, exprType);
m_Method = ctx.ResolveMethod(exprType, "Invoke");
var argTypes = m_Method.ArgumentTypes;
if (argTypes.Length != m_ArgTypes.Length)
Error(CompilerMessages.DelegateArgumentsCountMismatch, exprType, argTypes.Length, m_ArgTypes.Length);
for (var idx = 0; idx < argTypes.Length; idx++)
{
var fromType = m_ArgTypes[idx];
var toType = argTypes[idx];
if (!toType.IsExtendablyAssignableFrom(fromType))
Error(Arguments[idx], CompilerMessages.ArgumentTypeMismatch, fromType, toType);
}
m_InvocationSource = node;
}