3 files changed, 35 insertions, 0 deletions
diff --git a/libyul/backends/evm/AbstractAssembly.h b/libyul/backends/evm/AbstractAssembly.h
index 97b1d305..1f224ded 100644
--- a/libyul/backends/evm/AbstractAssembly.h
+++ b/libyul/backends/evm/AbstractAssembly.h
@@ -26,6 +26,7 @@
 #include <libdevcore/CommonData.h>
 
 #include <functional>
+#include <memory>
 
 namespace langutil
 {
@@ -52,6 +53,7 @@ class AbstractAssembly
 {
 public:
 	using LabelID = size_t;
+	using SubID = size_t;
 
 	virtual ~AbstractAssembly() {}
 
@@ -98,6 +100,14 @@ public:
 
 	/// Append the assembled size as a constant.
 	virtual void appendAssemblySize() = 0;
+	/// Creates a new sub-assembly, which can be referenced using dataSize and dataOffset.
+	virtual std::pair<std::shared_ptr<AbstractAssembly>, SubID> createSubAssembly() = 0;
+	/// Appends the offset of the given sub-assembly or data.
+	virtual void appendDataOffset(SubID _sub) = 0;
+	/// Appends the size of the given sub-assembly or data.
+	virtual void appendDataSize(SubID _sub) = 0;
+	/// Appends the given data to the assembly and returns its ID.
+	virtual SubID appendData(dev::bytes const& _data) = 0;
 };
 
 enum class IdentifierContext { LValue, RValue };
diff --git a/libyul/backends/evm/EVMAssembly.cpp b/libyul/backends/evm/EVMAssembly.cpp
index 99506317..2cf9f001 100644
--- a/libyul/backends/evm/EVMAssembly.cpp
+++ b/libyul/backends/evm/EVMAssembly.cpp
@@ -194,6 +194,27 @@ void EVMAssembly::appendAssemblySize()
 	m_bytecode += bytes(assemblySizeReferenceSize);
 }
 
+pair<shared_ptr<AbstractAssembly>, AbstractAssembly::SubID> EVMAssembly::createSubAssembly()
+{
+	solAssert(false, "Sub assemblies not implemented.");
+	return {};
+}
+
+void EVMAssembly::appendDataOffset(AbstractAssembly::SubID)
+{
+	solAssert(false, "Data not implemented.");
+}
+
+void EVMAssembly::appendDataSize(AbstractAssembly::SubID)
+{
+	solAssert(false, "Data not implemented.");
+}
+
+AbstractAssembly::SubID EVMAssembly::appendData(bytes const&)
+{
+	solAssert(false, "Data not implemented.");
+}
+
 void EVMAssembly::updateReference(size_t pos, size_t size, u256 value)
 {
 	solAssert(m_bytecode.size() >= size && pos <= m_bytecode.size() - size, "");
diff --git a/libyul/backends/evm/EVMAssembly.h b/libyul/backends/evm/EVMAssembly.h
index d0a437cc..cef9c19a 100644
--- a/libyul/backends/evm/EVMAssembly.h
+++ b/libyul/backends/evm/EVMAssembly.h
@@ -77,6 +77,10 @@ public:
 
 	/// Append the assembled size as a constant.
 	void appendAssemblySize() override;
+	std::pair<std::shared_ptr<AbstractAssembly>, SubID> createSubAssembly() override;
+	void appendDataOffset(SubID _sub) override;
+	void appendDataSize(SubID _sub) override;
+	SubID appendData(dev::bytes const& _data) override;
 
 	/// Resolves references inside the bytecode and returns the linker object.
 	dev::eth::LinkerObject finalize();