Move modifier context check to PostTypeChecker

refs #7566

libsolidity/analysis/PostTypeChecker.cpp

@@ -67,6 +67,15 @@ bool PostTypeChecker::visit(Identifier const& _identifier)
 	return callVisit(_identifier);
 }
 
+bool PostTypeChecker::visit(ModifierInvocation const& _modifierInvocation)
+{
+	return callVisit(_modifierInvocation);
+}
+
+void PostTypeChecker::endVisit(ModifierInvocation const& _modifierInvocation)
+{
+	callEndVisit(_modifierInvocation);
+}
 
 namespace
 {
@@ -183,11 +192,48 @@ struct OverrideSpecifierChecker: public PostTypeChecker::Checker
 		}
 	}
 };
-}
 
+struct ModifierContextChecker: public PostTypeChecker::Checker
+{
+	ModifierContextChecker(ErrorReporter& _errorReporter):
+		Checker(_errorReporter) {}
+
+	bool visit(ModifierInvocation const&) override
+	{
+		m_insideModifierInvocation = true;
+
+		return true;
+	}
+
+	void endVisit(ModifierInvocation const&) override
+	{
+		m_insideModifierInvocation = false;
+	}
+
+	bool visit(Identifier const& _identifier) override
+	{
+		if (m_insideModifierInvocation)
+			return true;
+
+		if (ModifierType const* type = dynamic_cast<decltype(type)>(_identifier.annotation().type))
+		{
+			m_errorReporter.typeError(
+				_identifier.location(),
+				"Modifier can only be referenced in function headers."
+			);
+		}
+
+		return false;
+	}
+private:
+	/// Flag indicating whether we are currently inside the invocation of a modifier
+	bool m_insideModifierInvocation = false;
+};
+}
 
 PostTypeChecker::PostTypeChecker(langutil::ErrorReporter& _errorReporter): m_errorReporter(_errorReporter)
 {
 	m_checkers.push_back(make_shared<ConstStateVarCircularReferenceChecker>(_errorReporter));
 	m_checkers.push_back(make_shared<OverrideSpecifierChecker>(_errorReporter));
+	m_checkers.push_back(make_shared<ModifierContextChecker>(_errorReporter));
 }

libsolidity/analysis/PostTypeChecker.h

@@ -36,6 +36,7 @@ namespace solidity::frontend
  * This module performs analyses on the AST that are done after type checking and assignments of types:
  *  - whether there are circular references in constant state variables
  *  - whether override specifiers are actually contracts
+ *  - whether a modifier is in a function header
  *
  *  When adding a new checker, make sure a visitor that forwards calls that your
  *  checker uses exists in PostTypeChecker. Add missing ones.
@@ -69,6 +70,9 @@ private:
 
 	bool visit(Identifier const& _identifier) override;
 
+	bool visit(ModifierInvocation const& _modifierInvocation) override;
+	void endVisit(ModifierInvocation const& _modifierInvocation) override;
+
 	template <class T>
 	bool callVisit(T const& _node)
 	{

libsolidity/analysis/TypeChecker.cpp

@@ -547,11 +547,7 @@ void TypeChecker::visitManually(
 	for (ASTPointer<Expression> const& argument: arguments)
 		argument->accept(*this);
 
-	{
-		m_insideModifierInvocation = true;
-		ScopeGuard resetFlag{[&] () { m_insideModifierInvocation = false; }};
-		_modifier.name()->accept(*this);
-	}
+	_modifier.name()->accept(*this);
 
 	auto const* declaration = &dereference(*_modifier.name());
 	vector<ASTPointer<VariableDeclaration>> emptyParameterList;
@@ -2704,15 +2700,6 @@ bool TypeChecker::visit(Identifier const& _identifier)
 			);
 	}
 
-	if (!m_insideModifierInvocation)
-		if (ModifierType const* type = dynamic_cast<decltype(type)>(_identifier.annotation().type))
-		{
-			m_errorReporter.typeError(
-				_identifier.location(),
-				"Modifier can only be referenced in function headers."
-			);
-		}
-
 	return false;
 }
 

libsolidity/analysis/TypeChecker.h

@@ -170,9 +170,6 @@ private:
 	/// Flag indicating whether we are currently inside a StructDefinition.
 	bool m_insideStruct = false;
 
-	/// Flag indicating whether we are currently inside the invocation of a modifier
-	bool m_insideModifierInvocation = false;
-
 	langutil::ErrorReporter& m_errorReporter;
 };