Add function that retrieves first FunctionDefinition up the scope path

libsolidity/ast/AST.cpp

@@ -400,6 +400,21 @@ SourceUnit const& Scopable::sourceUnit() const
 	return dynamic_cast<SourceUnit const&>(*s);
 }
 
+CallableDeclaration const* Scopable::functionOrModifierDefinition() const
+{
+	ASTNode const* s = scope();
+	solAssert(s, "");
+	while (dynamic_cast<Scopable const*>(s))
+	{
+		if (auto funDef = dynamic_cast<FunctionDefinition const*>(s))
+			return funDef;
+		if (auto modDef = dynamic_cast<ModifierDefinition const*>(s))
+			return modDef;
+		s = dynamic_cast<Scopable const*>(s)->scope();
+	}
+	return nullptr;
+}
+
 string Scopable::sourceUnitName() const
 {
 	return sourceUnit().annotation().path;

libsolidity/ast/AST.h

@@ -161,6 +161,9 @@ public:
 	/// @returns the source unit this scopable is present in.
 	SourceUnit const& sourceUnit() const;
 
+	/// @returns the function or modifier definition this scopable is present in or nullptr.
+	CallableDeclaration const* functionOrModifierDefinition() const;
+
 	/// @returns the source name this scopable is present in.
 	/// Can be combined with annotation().canonicalName (if present) to form a globally unique name.
 	std::string sourceUnitName() const;

libsolidity/ast/ASTForward.h

@@ -38,6 +38,7 @@ class SourceUnit;
 class PragmaDirective;
 class ImportDirective;
 class Declaration;
+class CallableDeclaration;
 class ContractDefinition;
 class InheritanceSpecifier;
 class UsingForDirective;