Check that no internals are used in any external function type.

3 files changed, 17 insertions, 1 deletions

diff --git a/libsolidity/analysis/ReferencesResolver.cpp b/libsolidity/analysis/ReferencesResolver.cpp
index c49af013..a0768a34 100644
--- a/libsolidity/analysis/ReferencesResolver.cpp
+++ b/libsolidity/analysis/ReferencesResolver.cpp
@@ -96,7 +96,14 @@ void ReferencesResolver::endVisit(FunctionTypeName const& _typeName)
 	}
 
 	if (_typeName.isPayable() && _typeName.visibility() != VariableDeclaration::Visibility::External)
-			fatalTypeError(_typeName.location(), "Only external function types can be payable.");
+		fatalTypeError(_typeName.location(), "Only external function types can be payable.");
+	if (_typeName.visibility() == VariableDeclaration::Visibility::External)
+		for (auto const& t: _typeName.parameterTypes() + _typeName.returnParameterTypes())
+		{
+			solAssert(t->annotation().type, "Type not set for parameter.");
+			if (!t->annotation().type->canBeUsedExternally(false))
+				fatalTypeError(t->location(), "Internal type cannot be used for external function type.");
+		}
 
 	_typeName.annotation().type = make_shared<FunctionType>(_typeName);
 }
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index f934b2c8..8b6d45e2 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -574,6 +574,14 @@ bool TypeChecker::visit(EventDefinition const& _eventDef)
 	return false;
 }
 
+void TypeChecker::endVisit(FunctionTypeName const& _funType)
+{
+	FunctionType const& fun = dynamic_cast<FunctionType const&>(*_funType.annotation().type);
+	if (fun.location() == FunctionType::Location::External)
+		if (!fun.canBeUsedExternally(false))
+			typeError(_funType.location(), "External function type uses internal types.");
+}
+
 bool TypeChecker::visit(InlineAssembly const& _inlineAssembly)
 {
 	// Inline assembly does not have its own type-checking phase, so we just run the
diff --git a/libsolidity/analysis/TypeChecker.h b/libsolidity/analysis/TypeChecker.h
index be1e02be..5874bb50 100644
--- a/libsolidity/analysis/TypeChecker.h
+++ b/libsolidity/analysis/TypeChecker.h
@@ -87,6 +87,7 @@ private:
 	/// case this is a base constructor call.
 	void visitManually(ModifierInvocation const& _modifier, std::vector<ContractDefinition const*> const& _bases);
 	virtual bool visit(EventDefinition const& _eventDef) override;
+	virtual void endVisit(FunctionTypeName const& _funType) override;
 	virtual bool visit(InlineAssembly const& _inlineAssembly) override;
 	virtual bool visit(IfStatement const& _ifStatement) override;
 	virtual bool visit(WhileStatement const& _whileStatement) override;