Merge pull request #8436 from ethereum/fixCallingBaseFunction

Fix calling unimplemented base function.

Changelog.md

@@ -10,6 +10,7 @@ Compiler Features:
 
 
 Bugfixes:
+ * Inheritance: Fix incorrect error on calling unimplemented base functions.
  * isoltest: Added new keyword `wei` to express function value in semantic tests
  * Standard-JSON-Interface: Fix a bug related to empty filenames and imports.
  * SMTChecker: Fix internal errors when analysing tuples.

libsolidity/analysis/TypeChecker.cpp

@@ -1703,22 +1703,21 @@ void TypeChecker::typeCheckFunctionCall(
 
 	if (_functionType->kind() == FunctionType::Kind::Declaration)
 	{
-		m_errorReporter.typeError(
+		if (
-			_functionCall.location(),
+			m_scope->derivesFrom(*_functionType->declaration().annotation().contract) &&
-			"Cannot call function via contract type name."
+			!dynamic_cast<FunctionDefinition const&>(_functionType->declaration()).isImplemented()
-		);
+		)
+			m_errorReporter.typeError(
+				_functionCall.location(),
+				"Cannot call unimplemented base function."
+			);
+		else
+			m_errorReporter.typeError(
+				_functionCall.location(),
+				"Cannot call function via contract type name."
+			);
 		return;
 	}
-	if (_functionType->kind() == FunctionType::Kind::Internal && _functionType->hasDeclaration())
-		if (auto const* functionDefinition = dynamic_cast<FunctionDefinition const*>(&_functionType->declaration()))
-			// functionDefinition->annotation().contract != m_scope ensures that this is a qualified access,
-			// e.g. ``A.f();`` instead of a simple function call like ``f();`` (the latter is valid for unimplemented
-			// functions).
-			if (functionDefinition->annotation().contract != m_scope && !functionDefinition->isImplemented())
-				m_errorReporter.typeError(
-					_functionCall.location(),
-					"Cannot call unimplemented base function."
-				);
 
 	// Check for unsupported use of bare static call
 	if (

libsolidity/ast/Types.cpp

@@ -3471,7 +3471,15 @@ MemberList::MemberMap TypeType::nativeMembers(ContractDefinition const* _current
 				continue;
 
 			if (!contract.isLibrary() && inDerivingScope && declaration->isVisibleInDerivedContracts())
-				members.emplace_back(declaration->name(), declaration->type(), declaration);
+			{
+				if (
+					auto const* functionDefinition = dynamic_cast<FunctionDefinition const*>(declaration);
+					functionDefinition && !functionDefinition->isImplemented()
+				)
+					members.emplace_back(declaration->name(), declaration->typeViaContractName(), declaration);
+				else
+					members.emplace_back(declaration->name(), declaration->type(), declaration);
+			}
 			else if (
 				(contract.isLibrary() && declaration->isVisibleAsLibraryMember()) ||
 				declaration->isVisibleViaContractTypeAccess()

test/libsolidity/semanticTests/functionCall/call_unimplemented_base.sol

@@ -0,0 +1,14 @@
+abstract contract I
+{
+    function a() internal view virtual returns(uint256);
+}
+abstract contract V is I
+{
+    function b() public view returns(uint256) { return a(); }
+}
+contract C is V
+{
+    function a() internal view override returns (uint256) { return 42;}
+}
+// ----
+// b() -> 42

test/libsolidity/syntaxTests/functionCalls/call_unimplemented_base.sol

@@ -0,0 +1,8 @@
+abstract contract I
+{
+    function a() internal view virtual returns(uint256);
+}
+abstract contract V is I
+{
+    function b() public view returns(uint256) { return a(); }
+}