make it work for var x = f;

4 files changed, 32 insertions, 21 deletions

diff --git a/AST.cpp b/AST.cpp
index 2aa57d7e..2fd60f7b 100644
--- a/AST.cpp
+++ b/AST.cpp
@@ -674,15 +674,23 @@ void FunctionCall::checkTypeRequirements()
 	else if (OverloadedFunctionType const* overloadedTypes = dynamic_cast<OverloadedFunctionType const*>(expressionType))
 	{
 		// this only applies to "x(3)" where x is assigned by "var x = f;" where f is an overloaded functions.
-		overloadedTypes->m_identifier->overloadResolution(*this);
-		FunctionType const* functionType = dynamic_cast<FunctionType const*>(overloadedTypes->m_identifier->getType().get());
+		auto identifier = dynamic_cast<Identifier*>(m_expression.get());
+		solAssert(identifier, "only applies to 'var x = f;'");
+
+		Declaration const* function = overloadedTypes->getIdentifier()->overloadResolution(*this);
+		if (!function)
+			BOOST_THROW_EXCEPTION(createTypeError("Can't resolve declarations"));
+
+		identifier->setReferencedDeclaration(*function);
+		identifier->checkTypeRequirements();
+
+		TypePointer type = identifier->getType();
+		FunctionType const* functionType = dynamic_cast<FunctionType const*>(type.get());
 
-		// @todo actually the return type should be an anonymous struct,
-		// but we change it to the type of the first return value until we have structs
 		if (functionType->getReturnParameterTypes().empty())
 			m_type = make_shared<VoidType>();
 		else
-			m_type = functionType->getReturnParameterTypes().front();		
+			m_type = functionType->getReturnParameterTypes().front();
 	}
 	else
 		BOOST_THROW_EXCEPTION(createTypeError("Type is not callable."));
@@ -781,7 +789,7 @@ void Identifier::checkTypeRequirementsWithFunctionCall(FunctionCall const& _func
 	solAssert(m_referencedDeclaration || !m_overloadedDeclarations.empty(), "Identifier not resolved.");
 
 	if (!m_referencedDeclaration)
-		overloadResolution(_functionCall);
+		setReferencedDeclaration(*overloadResolution(_functionCall));
 
 	checkTypeRequirements();
 }
@@ -791,7 +799,7 @@ void Identifier::checkTypeRequirementsFromVariableDeclaration()
 	solAssert(m_referencedDeclaration || !m_overloadedDeclarations.empty(), "Identifier not resolved.");
 
 	if (!m_referencedDeclaration)
-		m_type = make_shared<OverloadedFunctionType>(m_overloadedDeclarations, this);
+		m_type = make_shared<OverloadedFunctionType>(this);
 	else
 		checkTypeRequirements();
 
@@ -808,13 +816,11 @@ void Identifier::checkTypeRequirements()
 		BOOST_THROW_EXCEPTION(createTypeError("Declaration referenced before type could be determined."));
 }
 
-void Identifier::overloadResolution(FunctionCall const& _functionCall)
+Declaration const* Identifier::overloadResolution(FunctionCall const& _functionCall)
 {
 	solAssert(m_overloadedDeclarations.size() > 1, "FunctionIdentifier not resolved.");
 	solAssert(!m_referencedDeclaration, "Referenced declaration should be null before overload resolution.");
 
-	bool resolved = false;
-
 	std::vector<ASTPointer<Expression const>> arguments = _functionCall.getArguments();
 	std::vector<ASTPointer<ASTString>> const& argumentNames = _functionCall.getNames();
 
@@ -844,7 +850,7 @@ void Identifier::overloadResolution(FunctionCall const& _functionCall)
 			{
 				return declaration->getScope() == possibles.front()->getScope();
 			}))
-				setReferencedDeclaration(*possibles.front());
+				return possibles.front();
 		else
 			BOOST_THROW_EXCEPTION(createTypeError("Can't resolve identifier"));
 	}
@@ -852,6 +858,7 @@ void Identifier::overloadResolution(FunctionCall const& _functionCall)
 		// named arguments
 		// TODO: don't support right now
 		BOOST_THROW_EXCEPTION(createTypeError("Named arguments with overloaded functions are not supported yet."));
+	return nullptr;
 }
 
 void ElementaryTypeNameExpression::checkTypeRequirements()
diff --git a/AST.h b/AST.h
index fa1d4a92..6cc7f742 100644
--- a/AST.h
+++ b/AST.h
@@ -1157,7 +1157,7 @@ public:
 	void checkTypeRequirementsWithFunctionCall(FunctionCall const& _functionCall);
 	void checkTypeRequirementsFromVariableDeclaration();
 
-	void overloadResolution(FunctionCall const& _functionCall);
+	Declaration const* overloadResolution(FunctionCall const& _functionCall);
 private:
 
 	ASTPointer<ASTString> m_name;
diff --git a/ExpressionCompiler.cpp b/ExpressionCompiler.cpp
index 5e5442ba..4be461b2 100644
--- a/ExpressionCompiler.cpp
+++ b/ExpressionCompiler.cpp
@@ -822,11 +822,7 @@ bool ExpressionCompiler::visit(IndexAccess const& _indexAccess)
 void ExpressionCompiler::endVisit(Identifier const& _identifier)
 {
 	Declaration const* declaration = _identifier.getReferencedDeclaration();
-	if (declaration == nullptr)
-	{
-		// no-op
-	}
-	else if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
+	if (MagicVariableDeclaration const* magicVar = dynamic_cast<MagicVariableDeclaration const*>(declaration))
 	{
 		if (magicVar->getType()->getCategory() == Type::Category::Contract)
 			// "this" or "super"
@@ -849,6 +845,13 @@ void ExpressionCompiler::endVisit(Identifier const& _identifier)
 	{
 		// no-op
 	}
+	else if (declaration == nullptr && _identifier.getOverloadedDeclarations().size() > 1)
+	{
+		// var x = f;
+		declaration = *_identifier.getOverloadedDeclarations().begin();
+		FunctionDefinition const* functionDef = dynamic_cast<FunctionDefinition const*>(declaration);
+		m_context << m_context.getVirtualFunctionEntryLabel(*functionDef).pushTag();
+	}
 	else
 	{
 		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Identifier type not expected in expression context."));
diff --git a/Types.h b/Types.h
index 5dd742ad..b19f7540 100644
--- a/Types.h
+++ b/Types.h
@@ -527,13 +527,14 @@ private:
 class OverloadedFunctionType: public Type
 {
 public:
-	explicit OverloadedFunctionType(std::set<Declaration const*> const& _overloadedDeclarations, Identifier* _identifier):
-		m_overloadedDeclarations(_overloadedDeclarations), m_identifier(_identifier) {}
+	explicit OverloadedFunctionType(Identifier* _identifier): m_identifier(_identifier) {}
+
 	virtual Category getCategory() const override { return Category::OverloadedFunctions; }
 	virtual std::string toString() const override { return "OverloadedFunctions"; }
 
-// private:
-	std::set<Declaration const*> m_overloadedDeclarations;
+	Identifier* getIdentifier() const { return m_identifier; }
+
+private:
 	Identifier * m_identifier;
 };