Provide generic access to type definition for user-defined types.

Author: chriseth

libsolidity/ast/Types.cpp

@@ -2341,6 +2341,11 @@ TypeResult StructType::interfaceType(bool _inLibrary) const
 	return *m_interfaceType_library;
 }
 
+Declaration const* StructType::typeDefinition() const
+{
+	return &structDefinition();
+}
+
 BoolResult StructType::validForLocation(DataLocation _loc) const
 {
 	for (auto const& member: m_struct.members())
@@ -2473,6 +2478,11 @@ Type const* EnumType::encodingType() const
 	return TypeProvider::uint(8);
 }
 
+Declaration const* EnumType::typeDefinition() const
+{
+	return &enumDefinition();
+}
+
 TypeResult EnumType::unaryOperatorResult(Token _operator) const
 {
 	return _operator == Token::Delete ? TypeProvider::emptyTuple() : nullptr;
@@ -2541,6 +2551,11 @@ Type const& UserDefinedValueType::underlyingType() const
 	return *type;
 }
 
+Declaration const* UserDefinedValueType::typeDefinition() const
+{
+	return &m_definition;
+}
+
 string UserDefinedValueType::richIdentifier() const
 {
 	return "t_userDefinedValueType" + parenthesizeIdentifier(m_definition.name()) + to_string(m_definition.id());

libsolidity/ast/Types.h

@@ -369,6 +369,10 @@ class Type
 	/// are returned without modification.
 	virtual TypeResult interfaceType(bool /*_inLibrary*/) const { return nullptr; }
 
+	/// @returns the declaration of a user defined type (enum, struct, user defined value type).
+	/// Returns nullptr otherwise.
+	virtual Declaration const* typeDefinition() const { return nullptr; }
+
 	/// Clears all internally cached values (if any).
 	virtual void clearCache() const;
 
@@ -1004,6 +1008,8 @@ class StructType: public ReferenceType
 	Type const* encodingType() const override;
 	TypeResult interfaceType(bool _inLibrary) const override;
 
+	Declaration const* typeDefinition() const override;
+
 	BoolResult validForLocation(DataLocation _loc) const override;
 
 	bool recursive() const;
@@ -1069,6 +1075,8 @@ class EnumType: public Type
 		return _inLibrary ? this : encodingType();
 	}
 
+	Declaration const* typeDefinition() const override;
+
 	EnumDefinition const& enumDefinition() const { return m_enum; }
 	/// @returns the value that the string has in the Enum
 	unsigned int memberValue(ASTString const& _member) const;
@@ -1101,6 +1109,9 @@ class UserDefinedValueType: public Type
 	TypeResult binaryOperatorResult(Token, Type const*) const override { return nullptr; }
 	Type const* encodingType() const override { return &underlyingType(); }
 	TypeResult interfaceType(bool /* _inLibrary */) const override {return &underlyingType(); }
+
+	Declaration const* typeDefinition() const override;
+
 	std::string richIdentifier() const override;
 	bool operator==(Type const& _other) const override;