4 files changed, 114 insertions, 9 deletions
diff --git a/libsolidity/interface/CompilerStack.cpp b/libsolidity/interface/CompilerStack.cpp
index 3b5e65e8..7bc31c17 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();
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..1ddcd218
--- /dev/null
+++ b/libsolidity/interface/EVMVersion.h
@@ -0,0 +1,81 @@
+/*
+	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>
+
+namespace dev
+{
+namespace solidity
+{
+
+/**
+ * A version specifier of the EVM we want to compile to.
+ * Defaults to the latest version.
+ */
+class EVMVersion
+{
+public:
+	EVMVersion() {}
+
+	static EVMVersion homestead() { return {Version::Homestead}; }
+	static EVMVersion byzantium() { return {Version::Byzantium}; }
+
+	static boost::optional<EVMVersion> fromString(std::string const& _version)
+	{
+		if (_version == "homestead")
+			return homestead();
+		else if (_version == "byzantium")
+			return byzantium();
+		else
+			return {};
+	}
+
+	bool operator==(EVMVersion const& _other) const { return m_version == _other.m_version; }
+	bool operator!=(EVMVersion const& _other) const { return !this->operator==(_other); }
+
+	std::string name() const { return m_version == Version::Byzantium ? "byzantium" : "homestead"; }
+
+	/// Has the RETURNDATACOPY and RETURNDATASIZE opcodes.
+	bool supportsReturndata() const { return *this >= byzantium(); }
+	bool hasStaticCall() const { return *this >= byzantium(); }
+
+	/// 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
+	{
+		// @TODO when exactly was this introduced? Was together with the call stack fix.
+		return m_version == Version::Byzantium;
+	}
+
+private:
+	enum class Version { Homestead, Byzantium };
+
+	EVMVersion(Version _version): m_version(_version) {}
+
+	Version m_version = Version::Byzantium;
+};
+
+
+}
+}
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());