Support metadata via IR.

libyul/Object.cpp

@@ -65,10 +65,15 @@ string Object::toString(Dialect const* _dialect) const
 
 set<YulString> Object::qualifiedDataNames() const
 {
-	set<YulString> qualifiedNames = name.empty() ? set<YulString>{} : set<YulString>{name};
+	set<YulString> qualifiedNames =
+		name.empty() || contains(name.str(), '.') ?
+		set<YulString>{} :
+		set<YulString>{name};
 	for (shared_ptr<ObjectNode> const& subObjectNode: subObjects)
 	{
 		yulAssert(qualifiedNames.count(subObjectNode->name) == 0, "");
+		if (contains(subObjectNode->name.str(), '.'))
+			continue;
 		qualifiedNames.insert(subObjectNode->name);
 		if (auto const* subObject = dynamic_cast<Object const*>(subObjectNode.get()))
 			for (YulString const& subSubObj: subObject->qualifiedDataNames())

libyul/Object.h

@@ -71,6 +71,7 @@ public:
 
 	/// @returns the set of names of data objects accessible from within the code of
 	/// this object, including the name of object itself
+	/// Handles all names containing dots as reserved identifiers, not accessible as data.
 	std::set<YulString> qualifiedDataNames() const;
 
 	/// @returns vector of subIDs if possible to reach subobject with @a _qualifiedName, throws otherwise
@@ -92,6 +93,9 @@ public:
 	std::vector<std::shared_ptr<ObjectNode>> subObjects;
 	std::map<YulString, size_t> subIndexByName;
 	std::shared_ptr<yul::AsmAnalysisInfo> analysisInfo;
+
+	/// @returns the name of the special metadata data object.
+	static std::string metadataName() { return ".metadata"; }
 };
 
 }

libyul/backends/evm/AbstractAssembly.h

@@ -110,6 +110,9 @@ public:
 	/// Appends an assignment to an immutable variable.
 	virtual void appendImmutableAssignment(std::string const& _identifier) = 0;
 
+	/// Appends data to the very end of the bytecode. Repeated calls concatenate.
+	virtual void appendToAuxiliaryData(bytes const& _data) = 0;
+
 	/// Mark this assembly as invalid. Any attempt to request bytecode from it should throw.
 	virtual void markAsInvalid() = 0;
 };

libyul/backends/evm/EVMObjectCompiler.cpp

@@ -53,7 +53,11 @@ void EVMObjectCompiler::run(Object& _object, bool _optimize)
 		else
 		{
 			Data const& data = dynamic_cast<Data const&>(*subNode);
-			context.subIDs[data.name] = m_assembly.appendData(data.data);
+			// Special handling of metadata.
+			if (data.name.str() == Object::metadataName())
+				m_assembly.appendToAuxiliaryData(data.data);
+			else
+				context.subIDs[data.name] = m_assembly.appendData(data.data);
 		}
 
 	yulAssert(_object.analysisInfo, "No analysis info.");

libyul/backends/evm/EthAssemblyAdapter.cpp

@@ -161,6 +161,11 @@ AbstractAssembly::SubID EthAssemblyAdapter::appendData(bytes const& _data)
 	return subID;
 }
 
+void EthAssemblyAdapter::appendToAuxiliaryData(bytes const& _data)
+{
+	m_assembly.appendToAuxiliaryData(_data);
+}
+
 void EthAssemblyAdapter::appendImmutable(std::string const& _identifier)
 {
 	m_assembly.appendImmutable(_identifier);

libyul/backends/evm/EthAssemblyAdapter.h

@@ -58,6 +58,8 @@ public:
 	void appendDataSize(std::vector<SubID> const& _subPath) override;
 	SubID appendData(bytes const& _data) override;
 
+	void appendToAuxiliaryData(bytes const& _data) override;
+
 	void appendImmutable(std::string const& _identifier) override;
 	void appendImmutableAssignment(std::string const& _identifier) override;
 

libyul/backends/evm/NoOutputAssembly.h

@@ -70,6 +70,8 @@ public:
 	void appendDataSize(std::vector<SubID> const& _subPath) override;
 	SubID appendData(bytes const& _data) override;
 
+	void appendToAuxiliaryData(bytes const&) override {}
+
 	void appendImmutable(std::string const& _identifier) override;
 	void appendImmutableAssignment(std::string const& _identifier) override;