Merge pull request #5589 from ethereum/yulObjectCodegen

Yul object codegen

24 files changed, 755 insertions, 101 deletions

diff --git a/libsolidity/codegen/AsmCodeGen.cpp b/libsolidity/codegen/AsmCodeGen.cpp
index 83dd08fb..dfcc900b 100644
--- a/libsolidity/codegen/AsmCodeGen.cpp
+++ b/libsolidity/codegen/AsmCodeGen.cpp
@@ -27,10 +27,13 @@
 #include <libyul/backends/evm/EVMCodeTransform.h>
 
 #include <libevmasm/Assembly.h>
+#include <libevmasm/AssemblyItem.h>
 #include <libevmasm/Instruction.h>
 
 #include <liblangutil/SourceLocation.h>
 
+#include <libdevcore/FixedHash.h>
+
 #include <memory>
 #include <functional>
 
@@ -40,97 +43,136 @@ using namespace langutil;
 using namespace yul;
 using namespace dev::solidity;
 
-class EthAssemblyAdapter: public AbstractAssembly
-{
-public:
-	explicit EthAssemblyAdapter(eth::Assembly& _assembly):
-		m_assembly(_assembly)
-	{
-	}
-	virtual void setSourceLocation(SourceLocation const& _location) override
-	{
-		m_assembly.setSourceLocation(_location);
-	}
-	virtual int stackHeight() const override { return m_assembly.deposit(); }
-	virtual void appendInstruction(solidity::Instruction _instruction) override
-	{
-		m_assembly.append(_instruction);
-	}
-	virtual void appendConstant(u256 const& _constant) override
-	{
-		m_assembly.append(_constant);
-	}
-	/// Append a label.
-	virtual void appendLabel(LabelID _labelId) override
-	{
-		m_assembly.append(eth::AssemblyItem(eth::Tag, _labelId));
-	}
-	/// Append a label reference.
-	virtual void appendLabelReference(LabelID _labelId) override
-	{
-		m_assembly.append(eth::AssemblyItem(eth::PushTag, _labelId));
-	}
-	virtual size_t newLabelId() override
-	{
-		return assemblyTagToIdentifier(m_assembly.newTag());
-	}
-	virtual size_t namedLabel(std::string const& _name) override
-	{
-		return assemblyTagToIdentifier(m_assembly.namedTag(_name));
-	}
-	virtual void appendLinkerSymbol(std::string const& _linkerSymbol) override
-	{
-		m_assembly.appendLibraryAddress(_linkerSymbol);
-	}
-	virtual void appendJump(int _stackDiffAfter) override
-	{
-		appendInstruction(solidity::Instruction::JUMP);
-		m_assembly.adjustDeposit(_stackDiffAfter);
-	}
-	virtual void appendJumpTo(LabelID _labelId, int _stackDiffAfter) override
-	{
-		appendLabelReference(_labelId);
-		appendJump(_stackDiffAfter);
-	}
-	virtual void appendJumpToIf(LabelID _labelId) override
-	{
-		appendLabelReference(_labelId);
-		appendInstruction(solidity::Instruction::JUMPI);
-	}
-	virtual void appendBeginsub(LabelID, int) override
-	{
-		// TODO we could emulate that, though
-		solAssert(false, "BEGINSUB not implemented for EVM 1.0");
-	}
-	/// Call a subroutine.
-	virtual void appendJumpsub(LabelID, int, int) override
-	{
-		// TODO we could emulate that, though
-		solAssert(false, "JUMPSUB not implemented for EVM 1.0");
-	}
-
-	/// Return from a subroutine.
-	virtual void appendReturnsub(int, int) override
-	{
-		// TODO we could emulate that, though
-		solAssert(false, "RETURNSUB not implemented for EVM 1.0");
-	}
-
-	virtual void appendAssemblySize() override
-	{
-		m_assembly.appendProgramSize();
-	}
-
-private:
-	static LabelID assemblyTagToIdentifier(eth::AssemblyItem const& _tag)
-	{
-		u256 id = _tag.data();
-		solAssert(id <= std::numeric_limits<LabelID>::max(), "Tag id too large.");
-		return LabelID(id);
-	}
-
-	eth::Assembly& m_assembly;
-};
+EthAssemblyAdapter::EthAssemblyAdapter(eth::Assembly& _assembly):
+	m_assembly(_assembly)
+{
+}
+
+void EthAssemblyAdapter::setSourceLocation(SourceLocation const& _location)
+{
+	m_assembly.setSourceLocation(_location);
+}
+
+int EthAssemblyAdapter::stackHeight() const
+{
+	return m_assembly.deposit();
+}
+
+void EthAssemblyAdapter::appendInstruction(solidity::Instruction _instruction)
+{
+	m_assembly.append(_instruction);
+}
+
+void EthAssemblyAdapter::appendConstant(u256 const& _constant)
+{
+	m_assembly.append(_constant);
+}
+
+void EthAssemblyAdapter::appendLabel(LabelID _labelId)
+{
+	m_assembly.append(eth::AssemblyItem(eth::Tag, _labelId));
+}
+
+void EthAssemblyAdapter::appendLabelReference(LabelID _labelId)
+{
+	m_assembly.append(eth::AssemblyItem(eth::PushTag, _labelId));
+}
+
+size_t EthAssemblyAdapter::newLabelId()
+{
+	return assemblyTagToIdentifier(m_assembly.newTag());
+}
+
+size_t EthAssemblyAdapter::namedLabel(std::string const& _name)
+{
+	return assemblyTagToIdentifier(m_assembly.namedTag(_name));
+}
+
+void EthAssemblyAdapter::appendLinkerSymbol(std::string const& _linkerSymbol)
+{
+	m_assembly.appendLibraryAddress(_linkerSymbol);
+}
+
+void EthAssemblyAdapter::appendJump(int _stackDiffAfter)
+{
+	appendInstruction(solidity::Instruction::JUMP);
+	m_assembly.adjustDeposit(_stackDiffAfter);
+}
+
+void EthAssemblyAdapter::appendJumpTo(LabelID _labelId, int _stackDiffAfter)
+{
+	appendLabelReference(_labelId);
+	appendJump(_stackDiffAfter);
+}
+
+void EthAssemblyAdapter::appendJumpToIf(LabelID _labelId)
+{
+	appendLabelReference(_labelId);
+	appendInstruction(solidity::Instruction::JUMPI);
+}
+
+void EthAssemblyAdapter::appendBeginsub(LabelID, int)
+{
+	// TODO we could emulate that, though
+	solAssert(false, "BEGINSUB not implemented for EVM 1.0");
+}
+
+void EthAssemblyAdapter::appendJumpsub(LabelID, int, int)
+{
+	// TODO we could emulate that, though
+	solAssert(false, "JUMPSUB not implemented for EVM 1.0");
+}
+
+void EthAssemblyAdapter::appendReturnsub(int, int)
+{
+	// TODO we could emulate that, though
+	solAssert(false, "RETURNSUB not implemented for EVM 1.0");
+}
+
+void EthAssemblyAdapter::appendAssemblySize()
+{
+	m_assembly.appendProgramSize();
+}
+
+pair<shared_ptr<AbstractAssembly>, AbstractAssembly::SubID> EthAssemblyAdapter::createSubAssembly()
+{
+	shared_ptr<eth::Assembly> assembly{make_shared<eth::Assembly>()};
+	auto sub = m_assembly.newSub(assembly);
+	return {make_shared<EthAssemblyAdapter>(*assembly), size_t(sub.data())};
+}
+
+void EthAssemblyAdapter::appendDataOffset(AbstractAssembly::SubID _sub)
+{
+	auto it = m_dataHashBySubId.find(_sub);
+	if (it == m_dataHashBySubId.end())
+		m_assembly.pushSubroutineOffset(size_t(_sub));
+	else
+		m_assembly << eth::AssemblyItem(eth::PushData, it->second);
+}
+
+void EthAssemblyAdapter::appendDataSize(AbstractAssembly::SubID _sub)
+{
+	auto it = m_dataHashBySubId.find(_sub);
+	if (it == m_dataHashBySubId.end())
+		m_assembly.pushSubroutineSize(size_t(_sub));
+	else
+		m_assembly << u256(m_assembly.data(h256(it->second)).size());
+}
+
+AbstractAssembly::SubID EthAssemblyAdapter::appendData(bytes const& _data)
+{
+	eth::AssemblyItem pushData = m_assembly.newData(_data);
+	SubID subID = m_nextDataCounter++;
+	m_dataHashBySubId[subID] = pushData.data();
+	return subID;
+}
+
+EthAssemblyAdapter::LabelID EthAssemblyAdapter::assemblyTagToIdentifier(eth::AssemblyItem const& _tag)
+{
+	u256 id = _tag.data();
+	solAssert(id <= std::numeric_limits<LabelID>::max(), "Tag id too large.");
+	return LabelID(id);
+}
 
 void CodeGenerator::assemble(
 	Block const& _parsedData,
diff --git a/libsolidity/codegen/AsmCodeGen.h b/libsolidity/codegen/AsmCodeGen.h
index dc529e10..4c6d97f4 100644
--- a/libsolidity/codegen/AsmCodeGen.h
+++ b/libsolidity/codegen/AsmCodeGen.h
@@ -21,6 +21,9 @@
 #pragma once
 
 #include <libyul/AsmAnalysis.h>
+#include <libyul/backends/evm/AbstractAssembly.h>
+
+#include <liblangutil/SourceLocation.h>
 
 #include <functional>
 
@@ -34,11 +37,45 @@ namespace dev
 namespace eth
 {
 class Assembly;
+class AssemblyItem;
 }
 
 namespace solidity
 {
 
+class EthAssemblyAdapter: public yul::AbstractAssembly
+{
+public:
+	explicit EthAssemblyAdapter(eth::Assembly& _assembly);
+	void setSourceLocation(langutil::SourceLocation const& _location) override;
+	int stackHeight() const override;
+	void appendInstruction(solidity::Instruction _instruction) override;
+	void appendConstant(u256 const& _constant) override;
+	void appendLabel(LabelID _labelId) override;
+	void appendLabelReference(LabelID _labelId) override;
+	size_t newLabelId() override;
+	size_t namedLabel(std::string const& _name) override;
+	void appendLinkerSymbol(std::string const& _linkerSymbol) override;
+	void appendJump(int _stackDiffAfter) override;
+	void appendJumpTo(LabelID _labelId, int _stackDiffAfter) override;
+	void appendJumpToIf(LabelID _labelId) override;
+	void appendBeginsub(LabelID, int) override;
+	void appendJumpsub(LabelID, int, int) override;
+	void appendReturnsub(int, int) override;
+	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;
+
+private:
+	static LabelID assemblyTagToIdentifier(eth::AssemblyItem const& _tag);
+
+	eth::Assembly& m_assembly;
+	std::map<SubID, dev::u256> m_dataHashBySubId;
+	size_t m_nextDataCounter = std::numeric_limits<size_t>::max() / 2;
+};
+
 class CodeGenerator
 {
 public:
diff --git a/libsolidity/interface/AssemblyStack.cpp b/libsolidity/interface/AssemblyStack.cpp
index c15a192a..0fe57a45 100644
--- a/libsolidity/interface/AssemblyStack.cpp
+++ b/libsolidity/interface/AssemblyStack.cpp
@@ -29,6 +29,7 @@
 #include <libyul/AsmParser.h>
 #include <libyul/AsmAnalysis.h>
 #include <libyul/AsmAnalysisInfo.h>
+#include <libyul/backends/evm/EVMObjectCompiler.h>
 #include <libyul/backends/evm/EVMCodeTransform.h>
 #include <libyul/backends/evm/EVMAssembly.h>
 #include <libyul/ObjectParser.h>
@@ -85,20 +86,42 @@ bool AssemblyStack::parseAndAnalyze(std::string const& _sourceName, std::string
 void AssemblyStack::optimize()
 {
 	solAssert(m_language != Language::Assembly, "Optimization requested for loose assembly.");
-	yul::OptimiserSuite::run(*m_parserResult->code, *m_parserResult->analysisInfo);
+	solAssert(m_analysisSuccessful, "Analysis was not successful.");
+	m_analysisSuccessful = false;
+	optimize(*m_parserResult);
 	solAssert(analyzeParsed(), "Invalid source code after optimization.");
 }
 
 bool AssemblyStack::analyzeParsed()
 {
 	solAssert(m_parserResult, "");
-	solAssert(m_parserResult->code, "");
-	m_parserResult->analysisInfo = make_shared<yul::AsmAnalysisInfo>();
-	yul::AsmAnalyzer analyzer(*m_parserResult->analysisInfo, m_errorReporter, m_evmVersion, boost::none, languageToDialect(m_language));
-	m_analysisSuccessful = analyzer.analyze(*m_parserResult->code);
+	m_analysisSuccessful = analyzeParsed(*m_parserResult);
 	return m_analysisSuccessful;
 }
 
+bool AssemblyStack::analyzeParsed(yul::Object& _object)
+{
+	solAssert(_object.code, "");
+	_object.analysisInfo = make_shared<yul::AsmAnalysisInfo>();
+	yul::AsmAnalyzer analyzer(*_object.analysisInfo, m_errorReporter, m_evmVersion, boost::none, languageToDialect(m_language));
+	bool success = analyzer.analyze(*_object.code);
+	for (auto& subNode: _object.subObjects)
+		if (auto subObject = dynamic_cast<yul::Object*>(subNode.get()))
+			if (!analyzeParsed(*subObject))
+				success = false;
+	return success;
+}
+
+void AssemblyStack::optimize(yul::Object& _object)
+{
+	solAssert(_object.code, "");
+	solAssert(_object.analysisInfo, "");
+	for (auto& subNode: _object.subObjects)
+		if (auto subObject = dynamic_cast<yul::Object*>(subNode.get()))
+			optimize(*subObject);
+	yul::OptimiserSuite::run(*_object.code, *_object.analysisInfo);
+}
+
 MachineAssemblyObject AssemblyStack::assemble(Machine _machine) const
 {
 	solAssert(m_analysisSuccessful, "");
@@ -112,7 +135,8 @@ MachineAssemblyObject AssemblyStack::assemble(Machine _machine) const
 	{
 		MachineAssemblyObject object;
 		eth::Assembly assembly;
-		CodeGenerator::assemble(*m_parserResult->code, *m_parserResult->analysisInfo, assembly);
+		EthAssemblyAdapter adapter(assembly);
+		yul::EVMObjectCompiler::compile(*m_parserResult, adapter, m_language == Language::Yul, false);
 		object.bytecode = make_shared<eth::LinkerObject>(assembly.assemble());
 		object.assembly = assembly.assemblyString();
 		return object;
@@ -121,7 +145,7 @@ MachineAssemblyObject AssemblyStack::assemble(Machine _machine) const
 	{
 		MachineAssemblyObject object;
 		yul::EVMAssembly assembly(true);
-		yul::CodeTransform(assembly, *m_parserResult->analysisInfo, m_language == Language::Yul, true)(*m_parserResult->code);
+		yul::EVMObjectCompiler::compile(*m_parserResult, assembly, m_language == Language::Yul, true);
 		object.bytecode = make_shared<eth::LinkerObject>(assembly.finalize());
 		/// TODO: fill out text representation
 		return object;
diff --git a/libsolidity/interface/AssemblyStack.h b/libsolidity/interface/AssemblyStack.h
index 0d04ffec..485ec1e7 100644
--- a/libsolidity/interface/AssemblyStack.h
+++ b/libsolidity/interface/AssemblyStack.h
@@ -83,6 +83,9 @@ public:
 
 private:
 	bool analyzeParsed();
+	bool analyzeParsed(yul::Object& _object);
+
+	void optimize(yul::Object& _object);
 
 	Language m_language = Language::Assembly;
 	EVMVersion m_evmVersion;
diff --git a/libyul/CMakeLists.txt b/libyul/CMakeLists.txt
index 2dec0a44..4be8155f 100644
--- a/libyul/CMakeLists.txt
+++ b/libyul/CMakeLists.txt
@@ -9,6 +9,7 @@ add_library(yul
 	ObjectParser.cpp
 	backends/evm/EVMAssembly.cpp
 	backends/evm/EVMCodeTransform.cpp
+	backends/evm/EVMObjectCompiler.cpp
 	optimiser/ASTCopier.cpp
 	optimiser/ASTWalker.cpp
 	optimiser/BlockFlattener.cpp
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();
diff --git a/libyul/backends/evm/EVMObjectCompiler.cpp b/libyul/backends/evm/EVMObjectCompiler.cpp
new file mode 100644
index 00000000..e7e8ad99
--- /dev/null
+++ b/libyul/backends/evm/EVMObjectCompiler.cpp
@@ -0,0 +1,55 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Compiler that transforms Yul Objects to EVM bytecode objects.
+ */
+
+#include <libyul/backends/evm/EVMObjectCompiler.h>
+
+#include <libyul/backends/evm/EVMCodeTransform.h>
+#include <libyul/Object.h>
+#include <libyul/Exceptions.h>
+
+using namespace yul;
+using namespace std;
+
+void EVMObjectCompiler::compile(Object& _object, AbstractAssembly& _assembly, bool _yul, bool _evm15)
+{
+	EVMObjectCompiler compiler(_assembly, _yul, _evm15);
+	compiler.run(_object);
+}
+
+void EVMObjectCompiler::run(Object& _object)
+{
+	map<YulString, AbstractAssembly::SubID> subIDs;
+
+	for (auto& subNode: _object.subObjects)
+		if (Object* subObject = dynamic_cast<Object*>(subNode.get()))
+		{
+			auto subAssemblyAndID = m_assembly.createSubAssembly();
+			subIDs[subObject->name] = subAssemblyAndID.second;
+			compile(*subObject, *subAssemblyAndID.first, m_yul, m_evm15);
+		}
+		else
+		{
+			Data const& data = dynamic_cast<Data const&>(*subNode);
+			subIDs[data.name] = m_assembly.appendData(data.data);
+		}
+
+	yulAssert(_object.analysisInfo, "No analysis info.");
+	CodeTransform{m_assembly, *_object.analysisInfo, m_yul, m_evm15}(*_object.code);
+}
diff --git a/libyul/backends/evm/EVMObjectCompiler.h b/libyul/backends/evm/EVMObjectCompiler.h
new file mode 100644
index 00000000..c7172e47
--- /dev/null
+++ b/libyul/backends/evm/EVMObjectCompiler.h
@@ -0,0 +1,43 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * Compiler that transforms Yul Objects to EVM bytecode objects.
+ */
+
+
+namespace yul
+{
+struct Object;
+class AbstractAssembly;
+
+class EVMObjectCompiler
+{
+public:
+	static void compile(Object& _object, AbstractAssembly& _assembly, bool _yul, bool _evm15);
+private:
+	EVMObjectCompiler(AbstractAssembly& _assembly, bool _yul, bool _evm15):
+		m_assembly(_assembly), m_yul(_yul), m_evm15(_evm15)
+	{}
+
+	void run(Object& _object);
+
+	AbstractAssembly& m_assembly;
+	bool m_yul = false;
+	bool m_evm15 = false;
+};
+
+}
diff --git a/test/boostTest.cpp b/test/boostTest.cpp
index 7cb0c143..ff443d11 100644
--- a/test/boostTest.cpp
+++ b/test/boostTest.cpp
@@ -40,6 +40,7 @@
 #include <test/libsolidity/SyntaxTest.h>
 #include <test/libsolidity/SMTCheckerJSONTest.h>
 #include <test/libyul/YulOptimizerTest.h>
+#include <test/libyul/ObjectCompilerTest.h>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/algorithm/string/predicate.hpp>
@@ -146,6 +147,12 @@ test_suite* init_unit_test_suite( int /*argc*/, char* /*argv*/[] )
 		"yulOptimizerTests",
 		yul::test::YulOptimizerTest::create
 	) > 0, "no Yul Optimizer tests found");
+	solAssert(registerTests(
+		master,
+		dev::test::Options::get().testPath / "libyul",
+		"objectCompiler",
+		yul::test::ObjectCompilerTest::create
+	) > 0, "no Yul Object compiler tests found");
 	if (!dev::test::Options::get().disableSMT)
 	{
 		solAssert(registerTests(
diff --git a/test/libyul/ObjectCompilerTest.cpp b/test/libyul/ObjectCompilerTest.cpp
new file mode 100644
index 00000000..e60f718d
--- /dev/null
+++ b/test/libyul/ObjectCompilerTest.cpp
@@ -0,0 +1,134 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <test/libyul/ObjectCompilerTest.h>
+
+#include <test/libsolidity/FormattedScope.h>
+
+#include <libsolidity/interface/AssemblyStack.h>
+
+#include <libevmasm/Instruction.h>
+
+#include <liblangutil/SourceReferenceFormatter.h>
+
+#include <boost/algorithm/string.hpp>
+
+#include <fstream>
+
+using namespace dev;
+using namespace langutil;
+using namespace yul;
+using namespace yul::test;
+using namespace dev::solidity;
+using namespace dev::solidity::test;
+using namespace std;
+
+ObjectCompilerTest::ObjectCompilerTest(string const& _filename)
+{
+	boost::filesystem::path path(_filename);
+
+	ifstream file(_filename);
+	if (!file)
+		BOOST_THROW_EXCEPTION(runtime_error("Cannot open test case: \"" + _filename + "\"."));
+	file.exceptions(ios::badbit);
+
+	string line;
+	while (getline(file, line))
+	{
+		if (boost::algorithm::starts_with(line, "// ----"))
+			break;
+		if (m_source.empty() && boost::algorithm::starts_with(line, "// optimize"))
+			m_optimize = true;
+		m_source += line + "\n";
+	}
+	while (getline(file, line))
+		if (boost::algorithm::starts_with(line, "//"))
+			m_expectation += line.substr((line.size() >= 3 && line[2] == ' ') ? 3 : 2) + "\n";
+		else
+			m_expectation += line + "\n";
+}
+
+bool ObjectCompilerTest::run(ostream& _stream, string const& _linePrefix, bool const _formatted)
+{
+	AssemblyStack stack(EVMVersion(), AssemblyStack::Language::StrictAssembly);
+	if (!stack.parseAndAnalyze("source", m_source))
+	{
+		FormattedScope(_stream, _formatted, {formatting::BOLD, formatting::RED}) << _linePrefix << "Error parsing source." << endl;
+		printErrors(_stream, stack.errors());
+		return false;
+	}
+	if (m_optimize)
+		stack.optimize();
+
+	MachineAssemblyObject obj = stack.assemble(AssemblyStack::Machine::EVM);
+	solAssert(obj.bytecode, "");
+
+	m_obtainedResult = "Assembly:\n" + obj.assembly;
+	if (obj.bytecode->bytecode.empty())
+		m_obtainedResult += "-- empty bytecode --\n";
+	else
+		m_obtainedResult +=
+			"Bytecode: " +
+			toHex(obj.bytecode->bytecode) +
+			"\nOpcodes: " +
+			boost::trim_copy(solidity::disassemble(obj.bytecode->bytecode)) +
+			"\n";
+
+	if (m_expectation != m_obtainedResult)
+	{
+		string nextIndentLevel = _linePrefix + "  ";
+		FormattedScope(_stream, _formatted, {formatting::BOLD, formatting::CYAN}) << _linePrefix << "Expected result:" << endl;
+		printIndented(_stream, m_expectation, nextIndentLevel);
+		FormattedScope(_stream, _formatted, {formatting::BOLD, formatting::CYAN}) << _linePrefix << "Obtained result:" << endl;
+		printIndented(_stream, m_obtainedResult, nextIndentLevel);
+		return false;
+	}
+	return true;
+}
+
+void ObjectCompilerTest::printSource(ostream& _stream, string const& _linePrefix, bool const) const
+{
+	printIndented(_stream, m_source, _linePrefix);
+}
+
+void ObjectCompilerTest::printUpdatedExpectations(ostream& _stream, string const& _linePrefix) const
+{
+	printIndented(_stream, m_obtainedResult, _linePrefix);
+}
+
+void ObjectCompilerTest::printIndented(ostream& _stream, string const& _output, string const& _linePrefix) const
+{
+	stringstream output(_output);
+	string line;
+	while (getline(output, line))
+		if (line.empty())
+			// Avoid trailing spaces.
+			_stream << boost::trim_right_copy(_linePrefix) << endl;
+		else
+			_stream << _linePrefix << line << endl;
+}
+
+void ObjectCompilerTest::printErrors(ostream& _stream, ErrorList const& _errors)
+{
+	SourceReferenceFormatter formatter(_stream);
+
+	for (auto const& error: _errors)
+		formatter.printExceptionInformation(
+			*error,
+			(error->type() == Error::Type::Warning) ? "Warning" : "Error"
+		);
+}
diff --git a/test/libyul/ObjectCompilerTest.h b/test/libyul/ObjectCompilerTest.h
new file mode 100644
index 00000000..a5f8d777
--- /dev/null
+++ b/test/libyul/ObjectCompilerTest.h
@@ -0,0 +1,69 @@
+/*
+	This file is part of solidity.
+
+	solidity is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	solidity is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include <test/TestCase.h>
+
+namespace langutil
+{
+class Scanner;
+class Error;
+using ErrorList = std::vector<std::shared_ptr<Error const>>;
+}
+
+namespace yul
+{
+struct AsmAnalysisInfo;
+struct Block;
+}
+
+namespace yul
+{
+namespace test
+{
+
+class ObjectCompilerTest: public dev::solidity::test::TestCase
+{
+public:
+	static std::unique_ptr<TestCase> create(std::string const& _filename)
+	{
+		return std::unique_ptr<TestCase>(new ObjectCompilerTest(_filename));
+	}
+
+	explicit ObjectCompilerTest(std::string const& _filename);
+
+	bool run(std::ostream& _stream, std::string const& _linePrefix = "", bool const _formatted = false) override;
+
+	void printSource(std::ostream& _stream, std::string const &_linePrefix = "", bool const _formatted = false) const override;
+	void printUpdatedExpectations(std::ostream& _stream, std::string const& _linePrefix) const override;
+
+private:
+	void printIndented(std::ostream& _stream, std::string const& _output, std::string const& _linePrefix = "") const;
+	bool parse(std::ostream& _stream, std::string const& _linePrefix, bool const _formatted);
+	void disambiguate();
+
+	static void printErrors(std::ostream& _stream, langutil::ErrorList const& _errors);
+
+	std::string m_source;
+	bool m_optimize = false;
+	std::string m_expectation;
+	std::string m_obtainedResult;
+};
+
+}
+}
diff --git a/test/libyul/objectCompiler/data.yul b/test/libyul/objectCompiler/data.yul
new file mode 100644
index 00000000..daa22d21
--- /dev/null
+++ b/test/libyul/objectCompiler/data.yul
@@ -0,0 +1,11 @@
+object "a" {
+  code {}
+  // Unreferenced data is not added to the assembled bytecode.
+  data "str" "Hello, World!"
+}
+// ----
+// Assembly:
+// stop
+// data_acaf3289d7b601cbd114fb36c4d29c85bbfd5e133f14cb355c3fd8d99367964f 48656c6c6f2c20576f726c6421
+// Bytecode: fe
+// Opcodes: INVALID
diff --git a/test/libyul/objectCompiler/namedObject.yul b/test/libyul/objectCompiler/namedObject.yul
new file mode 100644
index 00000000..940160fd
--- /dev/null
+++ b/test/libyul/objectCompiler/namedObject.yul
@@ -0,0 +1,6 @@
+object "a" {
+  code {}
+}
+// ----
+// Assembly:
+// -- empty bytecode --
diff --git a/test/libyul/objectCompiler/namedObjectCode.yul b/test/libyul/objectCompiler/namedObjectCode.yul
new file mode 100644
index 00000000..4fc6891c
--- /dev/null
+++ b/test/libyul/objectCompiler/namedObjectCode.yul
@@ -0,0 +1,13 @@
+object "a" {
+  code { sstore(0, 1) }
+}
+// ----
+// Assembly:
+//     /* "source":32:33   */
+//   0x01
+//     /* "source":29:30   */
+//   0x00
+//     /* "source":22:34   */
+//   sstore
+// Bytecode: 6001600055
+// Opcodes: PUSH1 0x1 PUSH1 0x0 SSTORE
diff --git a/test/libyul/objectCompiler/nested_optimizer.yul b/test/libyul/objectCompiler/nested_optimizer.yul
new file mode 100644
index 00000000..7739ce61
--- /dev/null
+++ b/test/libyul/objectCompiler/nested_optimizer.yul
@@ -0,0 +1,49 @@
+// optimize
+object "a" {
+  code {
+    let x := calldataload(0)
+    let y := calldataload(0)
+    let z := sub(y, x)
+    sstore(add(x, 0), z)
+  }
+  object "sub" {
+    code {
+      let x := calldataload(0)
+      let y := calldataload(0)
+      let z := sub(y, x)
+      sstore(add(x, 0), z)
+    }
+  }
+}
+// ----
+// Assembly:
+//     /* "source":60:61   */
+//   0x00
+//     /* "source":137:138   */
+//   dup1
+//     /* "source":60:61   */
+//   dup2
+//     /* "source":47:62   */
+//   calldataload
+//     /* "source":119:139   */
+//   sstore
+//     /* "source":32:143   */
+//   pop
+// stop
+//
+// sub_0: assembly {
+//         /* "source":200:201   */
+//       0x00
+//         /* "source":283:284   */
+//       dup1
+//         /* "source":200:201   */
+//       dup2
+//         /* "source":187:202   */
+//       calldataload
+//         /* "source":265:285   */
+//       sstore
+//         /* "source":170:291   */
+//       pop
+// }
+// Bytecode: 60008081355550fe
+// Opcodes: PUSH1 0x0 DUP1 DUP2 CALLDATALOAD SSTORE POP INVALID
diff --git a/test/libyul/objectCompiler/simple.yul b/test/libyul/objectCompiler/simple.yul
new file mode 100644
index 00000000..d41b527c
--- /dev/null
+++ b/test/libyul/objectCompiler/simple.yul
@@ -0,0 +1,13 @@
+{
+  sstore(0, 1)
+}
+// ----
+// Assembly:
+//     /* "source":14:15   */
+//   0x01
+//     /* "source":11:12   */
+//   0x00
+//     /* "source":4:16   */
+//   sstore
+// Bytecode: 6001600055
+// Opcodes: PUSH1 0x1 PUSH1 0x0 SSTORE
diff --git a/test/libyul/objectCompiler/simple_optimizer.yul b/test/libyul/objectCompiler/simple_optimizer.yul
new file mode 100644
index 00000000..43b33553
--- /dev/null
+++ b/test/libyul/objectCompiler/simple_optimizer.yul
@@ -0,0 +1,23 @@
+// optimize
+{
+  let x := calldataload(0)
+  let y := calldataload(0)
+  let z := sub(y, x)
+  sstore(add(x, 0), z)
+}
+// ----
+// Assembly:
+//     /* "source":38:39   */
+//   0x00
+//     /* "source":109:110   */
+//   dup1
+//     /* "source":38:39   */
+//   dup2
+//     /* "source":25:40   */
+//   calldataload
+//     /* "source":91:111   */
+//   sstore
+//     /* "source":12:113   */
+//   pop
+// Bytecode: 60008081355550
+// Opcodes: PUSH1 0x0 DUP1 DUP2 CALLDATALOAD SSTORE POP
diff --git a/test/libyul/objectCompiler/smoke.yul b/test/libyul/objectCompiler/smoke.yul
new file mode 100644
index 00000000..b2e44d4d
--- /dev/null
+++ b/test/libyul/objectCompiler/smoke.yul
@@ -0,0 +1,5 @@
+{
+}
+// ----
+// Assembly:
+// -- empty bytecode --
diff --git a/test/libyul/objectCompiler/subObject.yul b/test/libyul/objectCompiler/subObject.yul
new file mode 100644
index 00000000..98ea4d07
--- /dev/null
+++ b/test/libyul/objectCompiler/subObject.yul
@@ -0,0 +1,21 @@
+object "a" {
+  code {}
+  // Unreferenced data is not added to the assembled bytecode.
+  data "str" "Hello, World!"
+  object "sub" { code { sstore(0, 1) } }
+}
+// ----
+// Assembly:
+// stop
+// data_acaf3289d7b601cbd114fb36c4d29c85bbfd5e133f14cb355c3fd8d99367964f 48656c6c6f2c20576f726c6421
+//
+// sub_0: assembly {
+//         /* "source":149:150   */
+//       0x01
+//         /* "source":146:147   */
+//       0x00
+//         /* "source":139:151   */
+//       sstore
+// }
+// Bytecode: fe
+// Opcodes: INVALID
diff --git a/test/libyul/objectCompiler/subSubObject.yul b/test/libyul/objectCompiler/subSubObject.yul
new file mode 100644
index 00000000..5e01f6dd
--- /dev/null
+++ b/test/libyul/objectCompiler/subSubObject.yul
@@ -0,0 +1,39 @@
+object "a" {
+  code {}
+  // Unreferenced data is not added to the assembled bytecode.
+  data "str" "Hello, World!"
+  object "sub" {
+    code { sstore(0, 1) }
+    object "subsub" {
+      code { sstore(2, 3) }
+      data "str" hex"123456"
+    }
+  }
+}
+// ----
+// Assembly:
+// stop
+// data_acaf3289d7b601cbd114fb36c4d29c85bbfd5e133f14cb355c3fd8d99367964f 48656c6c6f2c20576f726c6421
+//
+// sub_0: assembly {
+//         /* "source":153:154   */
+//       0x01
+//         /* "source":150:151   */
+//       0x00
+//         /* "source":143:155   */
+//       sstore
+//     stop
+//
+//     sub_0: assembly {
+//             /* "source":203:204   */
+//           0x03
+//             /* "source":200:201   */
+//           0x02
+//             /* "source":193:205   */
+//           sstore
+//         stop
+//         data_6adf031833174bbe4c85eafe59ddb54e6584648c2c962c6f94791ab49caa0ad4 123456
+//     }
+// }
+// Bytecode: fe
+// Opcodes: INVALID
diff --git a/test/tools/CMakeLists.txt b/test/tools/CMakeLists.txt
index 736212fc..da8e0b39 100644
--- a/test/tools/CMakeLists.txt
+++ b/test/tools/CMakeLists.txt
@@ -4,7 +4,19 @@ target_link_libraries(solfuzzer PRIVATE libsolc evmasm ${Boost_PROGRAM_OPTIONS_L
 add_executable(yulopti yulopti.cpp)
 target_link_libraries(yulopti PRIVATE solidity ${Boost_PROGRAM_OPTIONS_LIBRARIES} ${Boost_SYSTEM_LIBRARIES})
 
-add_executable(isoltest isoltest.cpp ../Options.cpp ../Common.cpp ../TestCase.cpp ../libsolidity/SyntaxTest.cpp
-        ../libsolidity/AnalysisFramework.cpp ../libsolidity/SolidityExecutionFramework.cpp ../ExecutionFramework.cpp
-        ../RPCSession.cpp ../libsolidity/ASTJSONTest.cpp ../libsolidity/SMTCheckerJSONTest.cpp ../libyul/YulOptimizerTest.cpp)
+add_executable(isoltest
+	isoltest.cpp
+	../Options.cpp
+	../Common.cpp
+	../TestCase.cpp
+	../libsolidity/SyntaxTest.cpp
+	../libsolidity/AnalysisFramework.cpp
+	../libsolidity/SolidityExecutionFramework.cpp
+	../ExecutionFramework.cpp
+	../RPCSession.cpp
+	../libsolidity/ASTJSONTest.cpp
+	../libsolidity/SMTCheckerJSONTest.cpp
+	../libyul/ObjectCompilerTest.cpp
+	../libyul/YulOptimizerTest.cpp
+)
 target_link_libraries(isoltest PRIVATE libsolc solidity evmasm ${Boost_PROGRAM_OPTIONS_LIBRARIES} ${Boost_UNIT_TEST_FRAMEWORK_LIBRARIES})
diff --git a/test/tools/isoltest.cpp b/test/tools/isoltest.cpp
index f8e2dc58..13585887 100644
--- a/test/tools/isoltest.cpp
+++ b/test/tools/isoltest.cpp
@@ -23,6 +23,7 @@
 #include <test/libsolidity/ASTJSONTest.h>
 #include <test/libsolidity/SMTCheckerJSONTest.h>
 #include <test/libyul/YulOptimizerTest.h>
+#include <test/libyul/ObjectCompilerTest.h>
 
 #include <boost/algorithm/string.hpp>
 #include <boost/algorithm/string/replace.hpp>
@@ -401,6 +402,17 @@ Allowed options)",
 	else
 		return 1;
 
+	if (auto stats = runTestSuite(
+		"Yul Object Compiler",
+		testPath / "libyul",
+		"objectCompiler",
+		yul::test::ObjectCompilerTest::create,
+		formatted
+	))
+		global_stats += *stats;
+	else
+		return 1;
+
 	if (!disableSMT)
 	{
 		if (auto stats = runTestSuite(