Merge pull request #3569 from ethereum/evmVersion

EVM version

19 files changed, 231 insertions, 66 deletions

diff --git a/libsolidity/analysis/ReferencesResolver.cpp b/libsolidity/analysis/ReferencesResolver.cpp
index 985c44d0..296a39c2 100644
--- a/libsolidity/analysis/ReferencesResolver.cpp
+++ b/libsolidity/analysis/ReferencesResolver.cpp
@@ -278,8 +278,9 @@ bool ReferencesResolver::visit(InlineAssembly const& _inlineAssembly)
 	};
 
 	// Will be re-generated later with correct information
+	// We use the latest EVM version because we will re-run it anyway.
 	assembly::AsmAnalysisInfo analysisInfo;
-	assembly::AsmAnalyzer(analysisInfo, errorsIgnored, assembly::AsmFlavour::Loose, resolver).analyze(_inlineAssembly.operations());
+	assembly::AsmAnalyzer(analysisInfo, errorsIgnored, EVMVersion(), assembly::AsmFlavour::Loose, resolver).analyze(_inlineAssembly.operations());
 	return false;
 }
 
diff --git a/libsolidity/analysis/TypeChecker.cpp b/libsolidity/analysis/TypeChecker.cpp
index cc7492dd..9846a0d0 100644
--- a/libsolidity/analysis/TypeChecker.cpp
+++ b/libsolidity/analysis/TypeChecker.cpp
@@ -875,6 +875,7 @@ bool TypeChecker::visit(InlineAssembly const& _inlineAssembly)
 	assembly::AsmAnalyzer analyzer(
 		*_inlineAssembly.annotation().analysisInfo,
 		m_errorReporter,
+		m_evmVersion,
 		assembly::AsmFlavour::Loose,
 		identifierAccess
 	);
diff --git a/libsolidity/analysis/TypeChecker.h b/libsolidity/analysis/TypeChecker.h
index 16796b63..2ba31232 100644
--- a/libsolidity/analysis/TypeChecker.h
+++ b/libsolidity/analysis/TypeChecker.h
@@ -22,6 +22,8 @@
 
 #pragma once
 
+#include <libsolidity/interface/EVMVersion.h>
+
 #include <libsolidity/ast/Types.h>
 #include <libsolidity/ast/ASTAnnotations.h>
 #include <libsolidity/ast/ASTForward.h>
@@ -43,7 +45,10 @@ class TypeChecker: private ASTConstVisitor
 {
 public:
 	/// @param _errorReporter provides the error logging functionality.
-	TypeChecker(ErrorReporter& _errorReporter): m_errorReporter(_errorReporter) {}
+	TypeChecker(EVMVersion _evmVersion, ErrorReporter& _errorReporter):
+		m_evmVersion(_evmVersion),
+		m_errorReporter(_errorReporter)
+	{}
 
 	/// Performs type checking on the given contract and all of its sub-nodes.
 	/// @returns true iff all checks passed. Note even if all checks passed, errors() can still contain warnings
@@ -132,6 +137,8 @@ private:
 
 	ContractDefinition const* m_scope = nullptr;
 
+	EVMVersion m_evmVersion;
+
 	/// Flag indicating whether we are currently inside an EmitStatement.
 	bool m_insideEmitStatement = false;
 
diff --git a/libsolidity/codegen/Compiler.h b/libsolidity/codegen/Compiler.h
index 06654486..f6865d75 100644
--- a/libsolidity/codegen/Compiler.h
+++ b/libsolidity/codegen/Compiler.h
@@ -22,22 +22,25 @@
 
 #pragma once
 
-#include <ostream>
-#include <functional>
 #include <libsolidity/codegen/CompilerContext.h>
+#include <libsolidity/interface/EVMVersion.h>
+
 #include <libevmasm/Assembly.h>
 
+#include <ostream>
+#include <functional>
+
 namespace dev {
 namespace solidity {
 
 class Compiler
 {
 public:
-	explicit Compiler(bool _optimize = false, unsigned _runs = 200):
+	explicit Compiler(EVMVersion _evmVersion = EVMVersion{}, bool _optimize = false, unsigned _runs = 200):
 		m_optimize(_optimize),
 		m_optimizeRuns(_runs),
-		m_runtimeContext(),
-		m_context(&m_runtimeContext)
+		m_runtimeContext(_evmVersion),
+		m_context(_evmVersion, &m_runtimeContext)
 	{ }
 
 	/// Compiles a contract.
diff --git a/libsolidity/codegen/CompilerContext.cpp b/libsolidity/codegen/CompilerContext.cpp
index 0198a107..ebf0213a 100644
--- a/libsolidity/codegen/CompilerContext.cpp
+++ b/libsolidity/codegen/CompilerContext.cpp
@@ -329,6 +329,7 @@ void CompilerContext::appendInlineAssembly(
 		analyzerResult = assembly::AsmAnalyzer(
 			analysisInfo,
 			errorReporter,
+			m_evmVersion,
 			assembly::AsmFlavour::Strict,
 			identifierAccess.resolve
 		).analyze(*parserResult);
diff --git a/libsolidity/codegen/CompilerContext.h b/libsolidity/codegen/CompilerContext.h
index a155a3a5..cf626683 100644
--- a/libsolidity/codegen/CompilerContext.h
+++ b/libsolidity/codegen/CompilerContext.h
@@ -24,6 +24,8 @@
 
 #include <libsolidity/codegen/ABIFunctions.h>
 
+#include <libsolidity/interface/EVMVersion.h>
+
 #include <libsolidity/ast/ASTForward.h>
 #include <libsolidity/ast/Types.h>
 #include <libsolidity/ast/ASTAnnotations.h>
@@ -50,14 +52,17 @@ namespace solidity {
 class CompilerContext
 {
 public:
-	explicit CompilerContext(CompilerContext* _runtimeContext = nullptr):
+	explicit CompilerContext(EVMVersion _evmVersion = EVMVersion{}, CompilerContext* _runtimeContext = nullptr):
 		m_asm(std::make_shared<eth::Assembly>()),
+		m_evmVersion(_evmVersion),
 		m_runtimeContext(_runtimeContext)
 	{
 		if (m_runtimeContext)
 			m_runtimeSub = size_t(m_asm->newSub(m_runtimeContext->m_asm).data());
 	}
 
+	EVMVersion const& evmVersion() const { return m_evmVersion; }
+
 	/// Update currently enabled set of experimental features.
 	void setExperimentalFeatures(std::set<ExperimentalFeature> const& _features) { m_experimentalFeatures = _features; }
 	/// @returns true if the given feature is enabled.
@@ -204,7 +209,7 @@ public:
 	void appendAuxiliaryData(bytes const& _data) { m_asm->appendAuxiliaryDataToEnd(_data); }
 
 	/// Run optimisation step.
-	void optimise(bool _fullOptimsation, unsigned _runs = 200) { m_asm->optimise(_fullOptimsation, true, _runs); }
+	void optimise(bool _fullOptimsation, unsigned _runs = 200) { m_asm->optimise(_fullOptimsation, m_evmVersion, true, _runs); }
 
 	/// @returns the runtime context if in creation mode and runtime context is set, nullptr otherwise.
 	CompilerContext* runtimeContext() { return m_runtimeContext; }
@@ -287,6 +292,8 @@ private:
 	} m_functionCompilationQueue;
 
 	eth::AssemblyPointer m_asm;
+	/// Version of the EVM to compile against.
+	EVMVersion m_evmVersion;
 	/// Activated experimental features.
 	std::set<ExperimentalFeature> m_experimentalFeatures;
 	/// Other already compiled contracts to be used in contract creation calls.
diff --git a/libsolidity/codegen/ContractCompiler.cpp b/libsolidity/codegen/ContractCompiler.cpp
index ebb718a5..5a9498f0 100644
--- a/libsolidity/codegen/ContractCompiler.cpp
+++ b/libsolidity/codegen/ContractCompiler.cpp
@@ -1059,7 +1059,7 @@ void ContractCompiler::compileExpression(Expression const& _expression, TypePoin
 		CompilerUtils(m_context).convertType(*_expression.annotation().type, *_targetType);
 }
 
-eth::AssemblyPointer ContractCompiler::cloneRuntime()
+eth::AssemblyPointer ContractCompiler::cloneRuntime() const
 {
 	eth::Assembly a;
 	a << Instruction::CALLDATASIZE;
@@ -1070,7 +1070,7 @@ eth::AssemblyPointer ContractCompiler::cloneRuntime()
 	// this is the address which has to be substituted by the linker.
 	//@todo implement as special "marker" AssemblyItem.
 	a << u256("0xcafecafecafecafecafecafecafecafecafecafe");
-	a << u256(eth::GasCosts::callGas + 10) << Instruction::GAS << Instruction::SUB;
+	a << u256(eth::GasCosts::callGas(m_context.evmVersion()) + 10) << Instruction::GAS << Instruction::SUB;
 	a << Instruction::DELEGATECALL;
 	//Propagate error condition (if DELEGATECALL pushes 0 on stack).
 	a << Instruction::ISZERO;
diff --git a/libsolidity/codegen/ContractCompiler.h b/libsolidity/codegen/ContractCompiler.h
index d698dc71..8559ea58 100644
--- a/libsolidity/codegen/ContractCompiler.h
+++ b/libsolidity/codegen/ContractCompiler.h
@@ -43,7 +43,7 @@ public:
 		m_runtimeCompiler(_runtimeCompiler),
 		m_context(_context)
 	{
-		m_context = CompilerContext(_runtimeCompiler ? &_runtimeCompiler->m_context : nullptr);
+		m_context = CompilerContext(_context.evmVersion(), _runtimeCompiler ? &_runtimeCompiler->m_context : nullptr);
 	}
 
 	void compileContract(
@@ -125,7 +125,7 @@ private:
 	void compileExpression(Expression const& _expression, TypePointer const& _targetType = TypePointer());
 
 	/// @returns the runtime assembly for clone contracts.
-	static eth::AssemblyPointer cloneRuntime();
+	eth::AssemblyPointer cloneRuntime() const;
 
 	bool const m_optimise;
 	/// Pointer to the runtime compiler in case this is a creation compiler.
diff --git a/libsolidity/codegen/ExpressionCompiler.cpp b/libsolidity/codegen/ExpressionCompiler.cpp
index 61920592..12881d63 100644
--- a/libsolidity/codegen/ExpressionCompiler.cpp
+++ b/libsolidity/codegen/ExpressionCompiler.cpp
@@ -1756,7 +1756,7 @@ void ExpressionCompiler::appendExternalFunctionCall(
 	{
 		// send all gas except the amount needed to execute "SUB" and "CALL"
 		// @todo this retains too much gas for now, needs to be fine-tuned.
-		u256 gasNeededByCaller = eth::GasCosts::callGas + 10;
+		u256 gasNeededByCaller = eth::GasCosts::callGas(m_context.evmVersion()) + 10;
 		if (_functionType.valueSet())
 			gasNeededByCaller += eth::GasCosts::callValueTransferGas;
 		if (!existenceChecked)
diff --git a/libsolidity/inlineasm/AsmAnalysis.cpp b/libsolidity/inlineasm/AsmAnalysis.cpp
index 1030523a..a7f764a5 100644
--- a/libsolidity/inlineasm/AsmAnalysis.cpp
+++ b/libsolidity/inlineasm/AsmAnalysis.cpp
@@ -533,33 +533,47 @@ void AsmAnalyzer::expectValidType(string const& type, SourceLocation const& _loc
 
 void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocation const& _location)
 {
-	static set<solidity::Instruction> futureInstructions{
-		solidity::Instruction::CREATE2,
-		solidity::Instruction::RETURNDATACOPY,
-		solidity::Instruction::RETURNDATASIZE,
-		solidity::Instruction::STATICCALL
-	};
-	if (futureInstructions.count(_instr))
+	// We assume that returndatacopy, returndatasize and staticcall are either all available
+	// or all not available.
+	solAssert(m_evmVersion.supportsReturndata() == m_evmVersion.hasStaticCall(), "");
+
+	if (_instr == solidity::Instruction::CREATE2)
 		m_errorReporter.warning(
 			_location,
 			"The \"" +
 			boost::to_lower_copy(instructionInfo(_instr).name)
-			+ "\" instruction is only available after " +
-			"the Metropolis hard fork. Before that it acts as an invalid instruction."
+			+ "\" instruction is not supported by the VM version \"" +
+			"" + m_evmVersion.name() +
+			"\" you are currently compiling for. " +
+			"It will be interpreted as an invalid instruction on this VM."
 		);
-
-	static set<solidity::Instruction> experimentalInstructions{
-		solidity::Instruction::SHL,
-		solidity::Instruction::SHR,
-		solidity::Instruction::SAR
-	};
-	if (experimentalInstructions.count(_instr))
+	else if ((
+		_instr == solidity::Instruction::RETURNDATACOPY ||
+		_instr == solidity::Instruction::RETURNDATASIZE ||
+		_instr == solidity::Instruction::STATICCALL
+	) && !m_evmVersion.supportsReturndata())
+		m_errorReporter.warning(
+			_location,
+			"The \"" +
+			boost::to_lower_copy(instructionInfo(_instr).name)
+			+ "\" instruction is only available for Byzantium-compatible VMs. " +
+			"You are currently compiling for \"" +
+			m_evmVersion.name() +
+			"\", where it will be interpreted as an invalid instruction."
+		);
+	else if ((
+		_instr == solidity::Instruction::SHL ||
+		_instr == solidity::Instruction::SHR ||
+		_instr == solidity::Instruction::SAR
+	) && !m_evmVersion.hasBitwiseShifting())
 		m_errorReporter.warning(
 			_location,
 			"The \"" +
 			boost::to_lower_copy(instructionInfo(_instr).name)
-			+ "\" instruction is only available after " +
-			"the Constantinople hard fork. Before that it acts as an invalid instruction."
+			+ "\" instruction is only available for Constantinople-compatible VMs. " +
+			"You are currently compiling for \"" +
+			m_evmVersion.name() +
+			"\", where it will be interpreted as an invalid instruction."
 		);
 
 	if (_instr == solidity::Instruction::JUMP || _instr == solidity::Instruction::JUMPI || _instr == solidity::Instruction::JUMPDEST)
diff --git a/libsolidity/inlineasm/AsmAnalysis.h b/libsolidity/inlineasm/AsmAnalysis.h
index 7a81dbf8..867711c7 100644
--- a/libsolidity/inlineasm/AsmAnalysis.h
+++ b/libsolidity/inlineasm/AsmAnalysis.h
@@ -21,6 +21,7 @@
 #pragma once
 
 #include <libsolidity/interface/Exceptions.h>
+#include <libsolidity/interface/EVMVersion.h>
 
 #include <libsolidity/inlineasm/AsmScope.h>
 
@@ -54,9 +55,10 @@ public:
 	explicit AsmAnalyzer(
 		AsmAnalysisInfo& _analysisInfo,
 		ErrorReporter& _errorReporter,
+		EVMVersion _evmVersion,
 		AsmFlavour _flavour = AsmFlavour::Loose,
 		julia::ExternalIdentifierAccess::Resolver const& _resolver = julia::ExternalIdentifierAccess::Resolver()
-	): m_resolver(_resolver), m_info(_analysisInfo), m_errorReporter(_errorReporter), m_flavour(_flavour) {}
+	): m_resolver(_resolver), m_info(_analysisInfo), m_errorReporter(_errorReporter), m_evmVersion(_evmVersion), m_flavour(_flavour) {}
 
 	bool analyze(assembly::Block const& _block);
 
@@ -97,6 +99,7 @@ private:
 	std::set<Scope::Variable const*> m_activeVariables;
 	AsmAnalysisInfo& m_info;
 	ErrorReporter& m_errorReporter;
+	EVMVersion m_evmVersion;
 	AsmFlavour m_flavour = AsmFlavour::Loose;
 };
 
diff --git a/libsolidity/interface/AssemblyStack.cpp b/libsolidity/interface/AssemblyStack.cpp
index c9e534c7..7a9fffbf 100644
--- a/libsolidity/interface/AssemblyStack.cpp
+++ b/libsolidity/interface/AssemblyStack.cpp
@@ -91,7 +91,7 @@ bool AssemblyStack::analyze(assembly::Block const& _block, Scanner const* _scann
 bool AssemblyStack::analyzeParsed()
 {
 	m_analysisInfo = make_shared<assembly::AsmAnalysisInfo>();
-	assembly::AsmAnalyzer analyzer(*m_analysisInfo, m_errorReporter, languageToAsmFlavour(m_language));
+	assembly::AsmAnalyzer analyzer(*m_analysisInfo, m_errorReporter, m_evmVersion, languageToAsmFlavour(m_language));
 	m_analysisSuccessful = analyzer.analyze(*m_parserResult);
 	return m_analysisSuccessful;
 }
diff --git a/libsolidity/interface/AssemblyStack.h b/libsolidity/interface/AssemblyStack.h
index 6ae7e8d1..720220ab 100644
--- a/libsolidity/interface/AssemblyStack.h
+++ b/libsolidity/interface/AssemblyStack.h
@@ -22,6 +22,8 @@
 #pragma once
 
 #include <libsolidity/interface/ErrorReporter.h>
+#include <libsolidity/interface/EVMVersion.h>
+
 #include <libevmasm/LinkerObject.h>
 
 #include <string>
@@ -54,8 +56,8 @@ public:
 	enum class Language { JULIA, Assembly, StrictAssembly };
 	enum class Machine { EVM, EVM15, eWasm };
 
-	explicit AssemblyStack(Language _language = Language::Assembly):
-		m_language(_language), m_errorReporter(m_errors)
+	explicit AssemblyStack(EVMVersion _evmVersion = EVMVersion(), Language _language = Language::Assembly):
+		m_language(_language), m_evmVersion(_evmVersion), m_errorReporter(m_errors)
 	{}
 
 	/// @returns the scanner used during parsing
@@ -82,6 +84,7 @@ private:
 	bool analyzeParsed();
 
 	Language m_language = Language::Assembly;
+	EVMVersion m_evmVersion;
 
 	std::shared_ptr<Scanner> m_scanner;
 
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 3b5e65e8..eacfca9c 100644
--- a/libsolidity/interface/CompilerStack.cpp
+++ b/libsolidity/interface/CompilerStack.cpp
@@ -74,6 +74,12 @@ void CompilerStack::setRemappings(vector<string> const& _remappings)
 	swap(m_remappings, remappings);
 }
 
+void CompilerStack::setEVMVersion(EVMVersion _version)
+{
+	solAssert(m_stackState < State::ParsingSuccessful, "Set EVM version after parsing.");
+	m_evmVersion = _version;
+}
+
 void CompilerStack::reset(bool _keepSources)
 {
 	if (_keepSources)
@@ -88,6 +94,7 @@ void CompilerStack::reset(bool _keepSources)
 		m_sources.clear();
 	}
 	m_libraries.clear();
+	m_evmVersion = EVMVersion();
 	m_optimize = false;
 	m_optimizeRuns = 200;
 	m_globalContext.reset();
@@ -198,7 +205,7 @@ bool CompilerStack::analyze()
 					m_contracts[contract->fullyQualifiedName()].contract = contract;
 			}
 
-	TypeChecker typeChecker(m_errorReporter);
+	TypeChecker typeChecker(m_evmVersion, m_errorReporter);
 	for (Source const* source: m_sourceOrder)
 		for (ASTPointer<ASTNode> const& node: source->ast->nodes())
 			if (ContractDefinition* contract = dynamic_cast<ContractDefinition*>(node.get()))
@@ -677,7 +684,7 @@ void CompilerStack::compileContract(
 	for (auto const* dependency: _contract.annotation().contractDependencies)
 		compileContract(*dependency, _compiledContracts);
 
-	shared_ptr<Compiler> compiler = make_shared<Compiler>(m_optimize, m_optimizeRuns);
+	shared_ptr<Compiler> compiler = make_shared<Compiler>(m_evmVersion, m_optimize, m_optimizeRuns);
 	Contract& compiledContract = m_contracts.at(_contract.fullyQualifiedName());
 	string metadata = createMetadata(compiledContract);
 	bytes cborEncodedHash =
@@ -736,7 +743,7 @@ void CompilerStack::compileContract(
 	{
 		if (!_contract.isLibrary())
 		{
-			Compiler cloneCompiler(m_optimize, m_optimizeRuns);
+			Compiler cloneCompiler(m_evmVersion, m_optimize, m_optimizeRuns);
 			cloneCompiler.compileClone(_contract, _compiledContracts);
 			compiledContract.cloneObject = cloneCompiler.assembledObject();
 		}
@@ -838,6 +845,7 @@ string CompilerStack::createMetadata(Contract const& _contract) const
 	}
 	meta["settings"]["optimizer"]["enabled"] = m_optimize;
 	meta["settings"]["optimizer"]["runs"] = m_optimizeRuns;
+	meta["settings"]["evmVersion"] = m_evmVersion.name();
 	meta["settings"]["compilationTarget"][_contract.contract->sourceUnitName()] =
 		_contract.contract->annotation().canonicalName;
 
@@ -951,11 +959,12 @@ Json::Value CompilerStack::gasEstimates(string const& _contractName) const
 		return Json::Value();
 
 	using Gas = GasEstimator::GasConsumption;
+	GasEstimator gasEstimator(m_evmVersion);
 	Json::Value output(Json::objectValue);
 
 	if (eth::AssemblyItems const* items = assemblyItems(_contractName))
 	{
-		Gas executionGas = GasEstimator::functionalEstimation(*items);
+		Gas executionGas = gasEstimator.functionalEstimation(*items);
 		u256 bytecodeSize(runtimeObject(_contractName).bytecode.size());
 		Gas codeDepositGas = bytecodeSize * eth::GasCosts::createDataGas;
 
@@ -976,14 +985,14 @@ Json::Value CompilerStack::gasEstimates(string const& _contractName) const
 		for (auto it: contract.interfaceFunctions())
 		{
 			string sig = it.second->externalSignature();
-			externalFunctions[sig] = gasToJson(GasEstimator::functionalEstimation(*items, sig));
+			externalFunctions[sig] = gasToJson(gasEstimator.functionalEstimation(*items, sig));
 		}
 
 		if (contract.fallbackFunction())
 			/// This needs to be set to an invalid signature in order to trigger the fallback,
 			/// without the shortcut (of CALLDATSIZE == 0), and therefore to receive the upper bound.
 			/// An empty string ("") would work to trigger the shortcut only.
-			externalFunctions[""] = gasToJson(GasEstimator::functionalEstimation(*items, "INVALID"));
+			externalFunctions[""] = gasToJson(gasEstimator.functionalEstimation(*items, "INVALID"));
 
 		if (!externalFunctions.empty())
 			output["external"] = externalFunctions;
@@ -999,7 +1008,7 @@ Json::Value CompilerStack::gasEstimates(string const& _contractName) const
 			size_t entry = functionEntryPoint(_contractName, *it);
 			GasEstimator::GasConsumption gas = GasEstimator::GasConsumption::infinite();
 			if (entry > 0)
-				gas = GasEstimator::functionalEstimation(*items, entry, *it);
+				gas = gasEstimator.functionalEstimation(*items, entry, *it);
 
 			/// TODO: This could move into a method shared with externalSignature()
 			FunctionType type(*it);
diff --git a/libsolidity/interface/CompilerStack.h b/libsolidity/interface/CompilerStack.h
index b377b3aa..13c9cc7a 100644
--- a/libsolidity/interface/CompilerStack.h
+++ b/libsolidity/interface/CompilerStack.h
@@ -23,20 +23,26 @@
 
 #pragma once
 
+#include <libsolidity/interface/ErrorReporter.h>
+#include <libsolidity/interface/ReadFile.h>
+#include <libsolidity/interface/EVMVersion.h>
+
+#include <libevmasm/SourceLocation.h>
+#include <libevmasm/LinkerObject.h>
+
+#include <libdevcore/Common.h>
+#include <libdevcore/FixedHash.h>
+
+#include <json/json.h>
+
+#include <boost/noncopyable.hpp>
+#include <boost/filesystem.hpp>
+
 #include <ostream>
 #include <string>
 #include <memory>
 #include <vector>
 #include <functional>
-#include <boost/noncopyable.hpp>
-#include <boost/filesystem.hpp>
-#include <json/json.h>
-#include <libdevcore/Common.h>
-#include <libdevcore/FixedHash.h>
-#include <libevmasm/SourceLocation.h>
-#include <libevmasm/LinkerObject.h>
-#include <libsolidity/interface/ErrorReporter.h>
-#include <libsolidity/interface/ReadFile.h>
 
 namespace dev
 {
@@ -116,6 +122,8 @@ public:
 		m_optimizeRuns = _runs;
 	}
 
+	void setEVMVersion(EVMVersion _version = EVMVersion{});
+
 	/// Sets the list of requested contract names. If empty, no filtering is performed and every contract
 	/// found in the supplied sources is compiled. Names are cleared iff @a _contractNames is missing.
 	void setRequestedContractNames(std::set<std::string> const& _contractNames = std::set<std::string>{})
@@ -310,6 +318,7 @@ private:
 	ReadCallback::Callback m_smtQuery;
 	bool m_optimize = false;
 	unsigned m_optimizeRuns = 200;
+	EVMVersion m_evmVersion;
 	std::set<std::string> m_requestedContractNames;
 	std::map<std::string, h160> m_libraries;
 	/// list of path prefix remappings, e.g. mylibrary: github.com/ethereum = /usr/local/ethereum
diff --git a/libsolidity/interface/EVMVersion.h b/libsolidity/interface/EVMVersion.h
new file mode 100644
index 00000000..13c4ec94
--- /dev/null
+++ b/libsolidity/interface/EVMVersion.h
@@ -0,0 +1,93 @@
+/*
+	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/>.
+*/
+/**
+ * EVM versioning.
+ */
+
+#pragma once
+
+#include <string>
+
+#include <boost/optional.hpp>
+#include <boost/operators.hpp>
+
+namespace dev
+{
+namespace solidity
+{
+
+/**
+ * A version specifier of the EVM we want to compile to.
+ * Defaults to the latest version.
+ */
+class EVMVersion:
+	boost::less_than_comparable<EVMVersion>,
+	boost::equality_comparable<EVMVersion>
+{
+public:
+	EVMVersion() {}
+
+	static EVMVersion homestead() { return {Version::Homestead}; }
+	static EVMVersion tangerineWhistle() { return {Version::TangerineWhistle}; }
+	static EVMVersion spuriousDragon() { return {Version::SpuriousDragon}; }
+	static EVMVersion byzantium() { return {Version::Byzantium}; }
+	static EVMVersion constantinople() { return {Version::Constantinople}; }
+
+	static boost::optional<EVMVersion> fromString(std::string const& _version)
+	{
+		for (auto const& v: {homestead(), tangerineWhistle(), spuriousDragon(), byzantium()})
+			if (_version == v.name())
+				return v;
+		return {};
+	}
+
+	bool operator==(EVMVersion const& _other) const { return m_version == _other.m_version; }
+	bool operator<(EVMVersion const& _other) const { return m_version < _other.m_version; }
+
+	std::string name() const
+	{
+		switch (m_version)
+		{
+		case Version::Homestead: return "homestead";
+		case Version::TangerineWhistle: return "tangerineWhistle";
+		case Version::SpuriousDragon: return "spuriousDragon";
+		case Version::Byzantium: return "byzantium";
+		case Version::Constantinople: return "constantinople";
+		}
+		return "INVALID";
+	}
+
+	/// Has the RETURNDATACOPY and RETURNDATASIZE opcodes.
+	bool supportsReturndata() const { return *this >= byzantium(); }
+	bool hasStaticCall() const { return *this >= byzantium(); }
+	bool hasBitwiseShifting() const { return *this >= constantinople(); }
+
+	/// Whether we have to retain the costs for the call opcode itself (false),
+	/// or whether we can just forward easily all remaining gas (true).
+	bool canOverchargeGasForCall() const { return *this >= tangerineWhistle(); }
+
+private:
+	enum class Version { Homestead, TangerineWhistle, SpuriousDragon, Byzantium, Constantinople };
+
+	EVMVersion(Version _version): m_version(_version) {}
+
+	Version m_version = Version::Byzantium;
+};
+
+
+}
+}
diff --git a/libsolidity/interface/GasEstimator.cpp b/libsolidity/interface/GasEstimator.cpp
index 22cc0266..2139395f 100644
--- a/libsolidity/interface/GasEstimator.cpp
+++ b/libsolidity/interface/GasEstimator.cpp
@@ -40,7 +40,7 @@ using namespace dev::solidity;
 GasEstimator::ASTGasConsumptionSelfAccumulated GasEstimator::structuralEstimation(
 	AssemblyItems const& _items,
 	vector<ASTNode const*> const& _ast
-)
+) const
 {
 	solAssert(std::count(_ast.begin(), _ast.end(), nullptr) == 0, "");
 	map<SourceLocation, GasConsumption> particularCosts;
@@ -49,7 +49,7 @@ GasEstimator::ASTGasConsumptionSelfAccumulated GasEstimator::structuralEstimatio
 	for (BasicBlock const& block: cfg.optimisedBlocks())
 	{
 		solAssert(!!block.startState, "");
-		GasMeter meter(block.startState->copy());
+		GasMeter meter(block.startState->copy(), m_evmVersion);
 		auto const end = _items.begin() + block.end;
 		for (auto iter = _items.begin() + block.begin; iter != end; ++iter)
 			particularCosts[iter->location()] += meter.estimateMax(*iter);
@@ -127,7 +127,7 @@ map<ASTNode const*, GasMeter::GasConsumption> GasEstimator::breakToStatementLeve
 GasEstimator::GasConsumption GasEstimator::functionalEstimation(
 	AssemblyItems const& _items,
 	string const& _signature
-)
+) const
 {
 	auto state = make_shared<KnownState>();
 
@@ -144,7 +144,7 @@ GasEstimator::GasConsumption GasEstimator::functionalEstimation(
 		});
 	}
 
-	PathGasMeter meter(_items);
+	PathGasMeter meter(_items, m_evmVersion);
 	return meter.estimateMax(0, state);
 }
 
@@ -152,7 +152,7 @@ GasEstimator::GasConsumption GasEstimator::functionalEstimation(
 	AssemblyItems const& _items,
 	size_t const& _offset,
 	FunctionDefinition const& _function
-)
+) const
 {
 	auto state = make_shared<KnownState>();
 
@@ -167,7 +167,7 @@ GasEstimator::GasConsumption GasEstimator::functionalEstimation(
 	if (parametersSize > 0)
 		state->feedItem(swapInstruction(parametersSize));
 
-	return PathGasMeter(_items).estimateMax(_offset, state);
+	return PathGasMeter(_items, m_evmVersion).estimateMax(_offset, state);
 }
 
 set<ASTNode const*> GasEstimator::finestNodesAtLocation(
diff --git a/libsolidity/interface/GasEstimator.h b/libsolidity/interface/GasEstimator.h
index bf63df96..ea94d988 100644
--- a/libsolidity/interface/GasEstimator.h
+++ b/libsolidity/interface/GasEstimator.h
@@ -22,11 +22,14 @@
 
 #pragma once
 
+#include <libsolidity/interface/EVMVersion.h>
+
+#include <libevmasm/GasMeter.h>
+#include <libevmasm/Assembly.h>
+
 #include <vector>
 #include <map>
 #include <array>
-#include <libevmasm/GasMeter.h>
-#include <libevmasm/Assembly.h>
 
 namespace dev
 {
@@ -44,13 +47,15 @@ public:
 	using ASTGasConsumptionSelfAccumulated =
 		std::map<ASTNode const*, std::array<GasConsumption, 2>>;
 
+	explicit GasEstimator(EVMVersion _evmVersion): m_evmVersion(_evmVersion) {}
+
 	/// Estimates the gas consumption for every assembly item in the given assembly and stores
 	/// it by source location.
 	/// @returns a mapping from each AST node to a pair of its particular and syntactically accumulated gas costs.
-	static ASTGasConsumptionSelfAccumulated structuralEstimation(
+	ASTGasConsumptionSelfAccumulated structuralEstimation(
 		eth::AssemblyItems const& _items,
 		std::vector<ASTNode const*> const& _ast
-	);
+	) const;
 	/// @returns a mapping from nodes with non-overlapping source locations to gas consumptions such that
 	/// the following source locations are part of the mapping:
 	/// 1. source locations of statements that do not contain other statements
@@ -62,23 +67,24 @@ public:
 
 	/// @returns the estimated gas consumption by the (public or external) function with the
 	/// given signature. If no signature is given, estimates the maximum gas usage.
-	static GasConsumption functionalEstimation(
+	GasConsumption functionalEstimation(
 		eth::AssemblyItems const& _items,
 		std::string const& _signature = ""
-	);
+	) const;
 
 	/// @returns the estimated gas consumption by the given function which starts at the given
 	/// offset into the list of assembly items.
 	/// @note this does not work correctly for recursive functions.
-	static GasConsumption functionalEstimation(
+	GasConsumption functionalEstimation(
 		eth::AssemblyItems const& _items,
 		size_t const& _offset,
 		FunctionDefinition const& _function
-	);
+	) const;
 
 private:
 	/// @returns the set of AST nodes which are the finest nodes at their location.
 	static std::set<ASTNode const*> finestNodesAtLocation(std::vector<ASTNode const*> const& _roots);
+	EVMVersion m_evmVersion;
 };
 
 }
diff --git a/libsolidity/interface/StandardCompiler.cpp b/libsolidity/interface/StandardCompiler.cpp
index 91fe72ae..ee9b1440 100644
--- a/libsolidity/interface/StandardCompiler.cpp
+++ b/libsolidity/interface/StandardCompiler.cpp
@@ -318,6 +318,14 @@ Json::Value StandardCompiler::compileInternal(Json::Value const& _input)
 
 	Json::Value const& settings = _input.get("settings", Json::Value());
 
+	if (settings.isMember("evmVersion"))
+	{
+		boost::optional<EVMVersion> version = EVMVersion::fromString(settings.get("evmVersion", {}).asString());
+		if (!version)
+			return formatFatalError("JSONError", "Invalid EVM version requested.");
+		m_compilerStack.setEVMVersion(*version);
+	}
+
 	vector<string> remappings;
 	for (auto const& remapping: settings.get("remappings", Json::Value()))
 		remappings.push_back(remapping.asString());