solidity/solc/CommandLineInterface.cpp

/*
	This file is part of cpp-ethereum.

	cpp-ethereum 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.

	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
 * @author Lefteris <lefteris@ethdev.com>
 * @author Gav Wood <g@ethdev.com>
 * @date 2014
 * Solidity command line interface.
 */
#include "CommandLineInterface.h"

#ifdef _WIN32 // windows
	#include <io.h>
	#define isatty _isatty
	#define fileno _fileno
#else // unix
	#include <unistd.h>
#endif
#include <string>
#include <iostream>
#include <fstream>

#include <boost/filesystem.hpp>
#include <boost/filesystem/operations.hpp>
#include <boost/algorithm/string.hpp>

#include "solidity/BuildInfo.h"
#include <libdevcore/Common.h>
#include <libdevcore/CommonData.h>
#include <libdevcore/CommonIO.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/GasMeter.h>
#include <libsolidity/interface/Version.h>
#include <libsolidity/parsing/Scanner.h>
#include <libsolidity/parsing/Parser.h>
#include <libsolidity/ast/ASTPrinter.h>
#include <libsolidity/ast/ASTJsonConverter.h>
#include <libsolidity/analysis/NameAndTypeResolver.h>
#include <libsolidity/interface/Exceptions.h>
#include <libsolidity/interface/CompilerStack.h>
#include <libsolidity/interface/SourceReferenceFormatter.h>
#include <libsolidity/interface/GasEstimator.h>
#include <libsolidity/inlineasm/AsmParser.h>
#include <libsolidity/formal/Why3Translator.h>

using namespace std;
namespace po = boost::program_options;

namespace dev
{
namespace solidity
{

static string const g_argAbiStr = "abi";
static string const g_argSignatureHashes = "hashes";
static string const g_argGas = "gas";
static string const g_argAsmStr = "asm";
static string const g_argAsmJsonStr = "asm-json";
static string const g_argAstStr = "ast";
static string const g_argAstJson = "ast-json";
static string const g_argBinaryStr = "bin";
static string const g_argRuntimeBinaryStr = "bin-runtime";
static string const g_argCloneBinaryStr = "clone-bin";
static string const g_argOpcodesStr = "opcodes";
static string const g_argNatspecDevStr = "devdoc";
static string const g_argNatspecUserStr = "userdoc";
static string const g_argAddStandard = "add-std";
static string const g_stdinFileName = "<stdin>";

/// Possible arguments to for --combined-json
static set<string> const g_combinedJsonArgs{
	"bin",
	"bin-runtime",
	"clone-bin",
	"srcmap",
	"srcmap-runtime",
	"opcodes",
	"abi",
	"interface",
	"asm",
	"ast",
	"userdoc",
	"devdoc"
};

static void version()
{
	cout <<
		"solc, the solidity compiler commandline interface" <<
		endl <<
		"Version: " <<
		dev::solidity::VersionString <<
		endl;
	exit(0);
}

static bool needsHumanTargetedStdout(po::variables_map const& _args)
{
	if (_args.count(g_argGas))
		return true;
	if (_args.count("output-dir"))
		return false;
	for (string const& arg: {
		g_argAbiStr,
		g_argSignatureHashes,
		g_argNatspecUserStr,
		g_argAstJson,
		g_argNatspecDevStr,
		g_argAsmStr,
		g_argAsmJsonStr,
		g_argOpcodesStr,
		g_argBinaryStr,
		g_argRuntimeBinaryStr,
		g_argCloneBinaryStr,
		string("formal")
	})
		if (_args.count(arg))
			return true;
	return false;
}

void CommandLineInterface::handleBinary(string const& _contract)
{
	if (m_args.count(g_argBinaryStr))
	{
		if (m_args.count("output-dir"))
			createFile(_contract + ".bin", m_compiler->object(_contract).toHex());
		else
		{
			cout << "Binary: " << endl;
			cout << m_compiler->object(_contract).toHex() << endl;
		}
	}
	if (m_args.count(g_argCloneBinaryStr))
	{
		if (m_args.count("output-dir"))
			createFile(_contract + ".clone_bin", m_compiler->cloneObject(_contract).toHex());
		else
		{
			cout << "Clone Binary: " << endl;
			cout << m_compiler->cloneObject(_contract).toHex() << endl;
		}
	}
	if (m_args.count(g_argRuntimeBinaryStr))
	{
		if (m_args.count("output-dir"))
			createFile(_contract + ".bin-runtime", m_compiler->runtimeObject(_contract).toHex());
		else
		{
			cout << "Binary of the runtime part: " << endl;
			cout << m_compiler->runtimeObject(_contract).toHex() << endl;
		}
	}
}

void CommandLineInterface::handleOpcode(string const& _contract)
{
	if (m_args.count("output-dir"))
		createFile(_contract + ".opcode", solidity::disassemble(m_compiler->object(_contract).bytecode));
	else
	{
		cout << "Opcodes: " << endl;
		cout << solidity::disassemble(m_compiler->object(_contract).bytecode);
		cout << endl;
	}
}

void CommandLineInterface::handleBytecode(string const& _contract)
{
	if (m_args.count(g_argOpcodesStr))
		handleOpcode(_contract);
	if (m_args.count(g_argBinaryStr) || m_args.count(g_argCloneBinaryStr) || m_args.count(g_argRuntimeBinaryStr))
		handleBinary(_contract);
}

void CommandLineInterface::handleSignatureHashes(string const& _contract)
{
	if (!m_args.count(g_argSignatureHashes))
		return;

	string out;
	for (auto const& it: m_compiler->contractDefinition(_contract).interfaceFunctions())
		out += toHex(it.first.ref()) + ": " + it.second->externalSignature() + "\n";

	if (m_args.count("output-dir"))
		createFile(_contract + ".signatures", out);
	else
		cout << "Function signatures: " << endl << out;
}

void CommandLineInterface::handleMeta(DocumentationType _type, string const& _contract)
{
	std::string argName;
	std::string suffix;
	std::string title;
	switch(_type)
	{
	case DocumentationType::ABIInterface:
		argName = g_argAbiStr;
		suffix = ".abi";
		title = "Contract JSON ABI";
		break;
	case DocumentationType::NatspecUser:
		argName = g_argNatspecUserStr;
		suffix = ".docuser";
		title = "User Documentation";
		break;
	case DocumentationType::NatspecDev:
		argName = g_argNatspecDevStr;
		suffix = ".docdev";
		title = "Developer Documentation";
		break;
	default:
		// should never happen
		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Unknown documentation _type"));
	}

	if (m_args.count(argName))
	{
		if (m_args.count("output-dir"))
			createFile(_contract + suffix, m_compiler->metadata(_contract, _type));
		else
		{
			cout << title << endl;
			cout << m_compiler->metadata(_contract, _type) << endl;
		}

	}
}

void CommandLineInterface::handleGasEstimation(string const& _contract)
{
	using Gas = GasEstimator::GasConsumption;
	if (!m_compiler->assemblyItems(_contract) && !m_compiler->runtimeAssemblyItems(_contract))
		return;
	cout << "Gas estimation:" << endl;
	if (eth::AssemblyItems const* items = m_compiler->assemblyItems(_contract))
	{
		Gas gas = GasEstimator::functionalEstimation(*items);
		u256 bytecodeSize(m_compiler->runtimeObject(_contract).bytecode.size());
		cout << "construction:" << endl;
		cout << "   " << gas << " + " << (bytecodeSize * eth::GasCosts::createDataGas) << " = ";
		gas += bytecodeSize * eth::GasCosts::createDataGas;
		cout << gas << endl;
	}
	if (eth::AssemblyItems const* items = m_compiler->runtimeAssemblyItems(_contract))
	{
		ContractDefinition const& contract = m_compiler->contractDefinition(_contract);
		cout << "external:" << endl;
		for (auto it: contract.interfaceFunctions())
		{
			string sig = it.second->externalSignature();
			GasEstimator::GasConsumption gas = GasEstimator::functionalEstimation(*items, sig);
			cout << "   " << sig << ":\t" << gas << endl;
		}
		if (contract.fallbackFunction())
		{
			GasEstimator::GasConsumption gas = GasEstimator::functionalEstimation(*items, "INVALID");
			cout << "   fallback:\t" << gas << endl;
		}
		cout << "internal:" << endl;
		for (auto const& it: contract.definedFunctions())
		{
			if (it->isPartOfExternalInterface() || it->isConstructor())
				continue;
			size_t entry = m_compiler->functionEntryPoint(_contract, *it);
			GasEstimator::GasConsumption gas = GasEstimator::GasConsumption::infinite();
			if (entry > 0)
				gas = GasEstimator::functionalEstimation(*items, entry, *it);
			FunctionType type(*it);
			cout << "   " << it->name() << "(";
			auto paramTypes = type.parameterTypes();
			for (auto it = paramTypes.begin(); it != paramTypes.end(); ++it)
				cout << (*it)->toString() << (it + 1 == paramTypes.end() ? "" : ",");
			cout << "):\t" << gas << endl;
		}
	}
}

void CommandLineInterface::handleFormal()
{
	if (!m_args.count("formal"))
		return;

	if (m_args.count("output-dir"))
		createFile("solidity.mlw", m_compiler->formalTranslation());
	else
		cout << "Formal version:" << endl << m_compiler->formalTranslation() << endl;
}

void CommandLineInterface::readInputFilesAndConfigureRemappings()
{
	vector<string> inputFiles;
	bool addStdin = false;
	if (!m_args.count("input-file"))
		addStdin = true;
	else
		for (string path: m_args["input-file"].as<vector<string>>())
		{
			auto eq = find(path.begin(), path.end(), '=');
			if (eq != path.end())
				path = string(eq + 1, path.end());
			else if (path == "-")
				addStdin = true;
			else
			{
				auto infile = boost::filesystem::path(path);
				if (!boost::filesystem::exists(infile))
				{
					cerr << "Skipping non existant input file \"" << infile << "\"" << endl;
					continue;
				}

				if (!boost::filesystem::is_regular_file(infile))
				{
					cerr << "\"" << infile << "\" is not a valid file. Skipping" << endl;
					continue;
				}

				m_sourceCodes[infile.string()] = dev::contentsString(infile.string());
				path = boost::filesystem::canonical(infile).string();
			}
			m_allowedDirectories.push_back(boost::filesystem::path(path).remove_filename());
		}
	if (addStdin)
	{
		string s;
		while (!cin.eof())
		{
			getline(cin, s);
			m_sourceCodes[g_stdinFileName].append(s + '\n');
		}
	}
}

bool CommandLineInterface::parseLibraryOption(string const& _input)
{
	namespace fs = boost::filesystem;
	string data = fs::is_regular_file(_input) ? contentsString(_input) : _input;

	vector<string> libraries;
	boost::split(libraries, data, boost::is_space() || boost::is_any_of(","), boost::token_compress_on);
	for (string const& lib: libraries)
		if (!lib.empty())
		{
			auto colon = lib.find(':');
			if (colon == string::npos)
			{
				cerr << "Colon separator missing in library address specifier \"" << lib << "\"" << endl;
				return false;
			}
			string libName(lib.begin(), lib.begin() + colon);
			string addrString(lib.begin() + colon + 1, lib.end());
			boost::trim(libName);
			boost::trim(addrString);
			bytes binAddr = fromHex(addrString);
			h160 address(binAddr, h160::AlignRight);
			if (binAddr.size() > 20 || address == h160())
			{
				cerr << "Invalid address for library \"" << libName << "\": " << addrString << endl;
				return false;
			}
			m_libraries[libName] = address;
		}

	return true;
}

void CommandLineInterface::createFile(string const& _fileName, string const& _data)
{
	namespace fs = boost::filesystem;
	// create directory if not existent
	fs::path p(m_args.at("output-dir").as<string>());
	fs::create_directories(p);
	string pathName = (p / _fileName).string();
	ofstream outFile(pathName);
	outFile << _data;
	if (!outFile)
		BOOST_THROW_EXCEPTION(FileError() << errinfo_comment("Could not write to file: " + pathName));
}

bool CommandLineInterface::parseArguments(int _argc, char** _argv)
{
	// Declare the supported options.
	po::options_description desc(
		R"(solc, the Solidity commandline compiler.
Usage: solc [options] [input_file...]
Compiles the given Solidity input files (or the standard input if none given or
"-" is used as a file name) and outputs the components specified in the options
at standard output or in files in the output directory, if specified.
Example: solc --bin -o /tmp/solcoutput contract.sol

Allowed options)",
		po::options_description::m_default_line_length,
		po::options_description::m_default_line_length - 23);
	desc.add_options()
		("help", "Show help message and exit.")
		("version", "Show version and exit.")
		("optimize", "Enable bytecode optimizer.")
		(
			"optimize-runs",
			po::value<unsigned>()->value_name("n")->default_value(200),
			"Estimated number of contract runs for optimizer tuning."
		)
		(g_argAddStandard.c_str(), "Add standard contracts.")
		(
			"libraries",
			po::value<vector<string>>()->value_name("libs"),
			"Direct string or file containing library addresses. Syntax: "
			"<libraryName>: <address> [, or whitespace] ...\n"
			"Address is interpreted as a hex string optionally prefixed by 0x."
		)
		(
			"output-dir,o",
			po::value<string>()->value_name("path"),
			"If given, creates one file per component and contract/file at the specified directory."
		)
		(
			"combined-json",
			po::value<string>()->value_name(boost::join(g_combinedJsonArgs, ",")),
			"Output a single json document containing the specified information."
		)
		(g_argGas.c_str(), "Print an estimate of the maximal gas usage for each function.")
		(
			"assemble",
			"Switch to assembly mode, ignoring all options and assumes input is assembly."
		)
		(
			"link",
			"Switch to linker mode, ignoring all options apart from --libraries "
			"and modify binaries in place."
		);
	po::options_description outputComponents("Output Components");
	outputComponents.add_options()
		(g_argAstStr.c_str(), "AST of all source files.")
		(g_argAstJson.c_str(), "AST of all source files in JSON format.")
		(g_argAsmStr.c_str(), "EVM assembly of the contracts.")
		(g_argAsmJsonStr.c_str(), "EVM assembly of the contracts in JSON format.")
		(g_argOpcodesStr.c_str(), "Opcodes of the contracts.")
		(g_argBinaryStr.c_str(), "Binary of the contracts in hex.")
		(g_argRuntimeBinaryStr.c_str(), "Binary of the runtime part of the contracts in hex.")
		(g_argCloneBinaryStr.c_str(), "Binary of the clone contracts in hex.")
		(g_argAbiStr.c_str(), "ABI specification of the contracts.")
		(g_argSignatureHashes.c_str(), "Function signature hashes of the contracts.")
		(g_argNatspecUserStr.c_str(), "Natspec user documentation of all contracts.")
		(g_argNatspecDevStr.c_str(), "Natspec developer documentation of all contracts.")
		("formal", "Translated source suitable for formal analysis.");
	desc.add(outputComponents);

	po::options_description allOptions = desc;
	allOptions.add_options()("input-file", po::value<vector<string>>(), "input file");

	// All positional options should be interpreted as input files
	po::positional_options_description filesPositions;
	filesPositions.add("input-file", -1);

	// parse the compiler arguments
	try
	{
		po::command_line_parser cmdLineParser(_argc, _argv);
		cmdLineParser.options(allOptions).positional(filesPositions).allow_unregistered();
		po::store(cmdLineParser.run(), m_args);
	}
	catch (po::error const& _exception)
	{
		cerr << _exception.what() << endl;
		return false;
	}

	if (m_args.count("help") || (isatty(fileno(stdin)) && _argc == 1))
	{
		cout << desc;
		return false;
	}

	if (m_args.count("version"))
	{
		version();
		return false;
	}

	if (m_args.count("combined-json"))
	{
		vector<string> requests;
		for (string const& item: boost::split(requests, m_args["combined-json"].as<string>(), boost::is_any_of(",")))
			if (!g_combinedJsonArgs.count(item))
			{
				cerr << "Invalid option to --combined-json: " << item << endl;
				return false;
			}
	}
	po::notify(m_args);

	return true;
}

bool CommandLineInterface::processInput()
{
	readInputFilesAndConfigureRemappings();

	if (m_args.count("libraries"))
		for (string const& library: m_args["libraries"].as<vector<string>>())
			if (!parseLibraryOption(library))
				return false;

	if (m_args.count("assemble"))
	{
		// switch to assembly mode
		m_onlyAssemble = true;
		return assemble();
	}
	if (m_args.count("link"))
	{
		// switch to linker mode
		m_onlyLink = true;
		return link();
	}

	CompilerStack::ReadFileCallback fileReader = [this](string const& _path)
	{
		auto path = boost::filesystem::path(_path);
		if (!boost::filesystem::exists(path))
			return CompilerStack::ReadFileResult{false, "File not found."};
		auto canonicalPath = boost::filesystem::canonical(path);
		bool isAllowed = false;
		for (auto const& allowedDir: m_allowedDirectories)
		{
			// If dir is a prefix of boostPath, we are fine.
			if (
				std::distance(allowedDir.begin(), allowedDir.end()) <= std::distance(canonicalPath.begin(), canonicalPath.end()) &&
				std::equal(allowedDir.begin(), allowedDir.end(), canonicalPath.begin())
			)
			{
				isAllowed = true;
				break;
			}
		}
		if (!isAllowed)
			return CompilerStack::ReadFileResult{false, "File outside of allowed directories."};
		else if (!boost::filesystem::is_regular_file(canonicalPath))
			return CompilerStack::ReadFileResult{false, "Not a valid file."};
		else
		{
			auto contents = dev::contentsString(canonicalPath.string());
			m_sourceCodes[path.string()] = contents;
			return CompilerStack::ReadFileResult{true, contents};
		}
	};

	m_compiler.reset(new CompilerStack(fileReader));
	auto scannerFromSourceName = [&](string const& _sourceName) -> solidity::Scanner const& { return m_compiler->scanner(_sourceName); };
	try
	{
		if (m_args.count("input-file"))
			m_compiler->setRemappings(m_args["input-file"].as<vector<string>>());
		for (auto const& sourceCode: m_sourceCodes)
			m_compiler->addSource(sourceCode.first, sourceCode.second);
		// TODO: Perhaps we should not compile unless requested
		bool optimize = m_args.count("optimize") > 0;
		unsigned runs = m_args["optimize-runs"].as<unsigned>();
		bool successful = m_compiler->compile(optimize, runs);
		if (successful)
			m_compiler->link(m_libraries);

		if (successful && m_args.count("formal"))
			if (!m_compiler->prepareFormalAnalysis())
				successful = false;

		for (auto const& error: m_compiler->errors())
			SourceReferenceFormatter::printExceptionInformation(
				cerr,
				*error,
				(error->type() == Error::Type::Warning) ? "Warning" : "Error",
				scannerFromSourceName
			);

		if (!successful)
			return false;
	}
	catch (CompilerError const& _exception)
	{
		SourceReferenceFormatter::printExceptionInformation(cerr, _exception, "Compiler error", scannerFromSourceName);
		return false;
	}
	catch (InternalCompilerError const& _exception)
	{
		cerr << "Internal compiler error during compilation:" << endl
			 << boost::diagnostic_information(_exception);
		return false;
	}
	catch (Error const& _error)
	{
		if (_error.type() == Error::Type::DocstringParsingError)
			cerr << "Documentation parsing error: " << *boost::get_error_info<errinfo_comment>(_error) << endl;
		else
			SourceReferenceFormatter::printExceptionInformation(cerr, _error, _error.typeName(), scannerFromSourceName);

		return false;
	}
	catch (Exception const& _exception)
	{
		cerr << "Exception during compilation: " << boost::diagnostic_information(_exception) << endl;
		return false;
	}
	catch (...)
	{
		cerr << "Unknown exception during compilation." << endl;
		return false;
	}

	return true;
}

void CommandLineInterface::handleCombinedJSON()
{
	if (!m_args.count("combined-json"))
		return;

	Json::Value output(Json::objectValue);

	output["version"] = ::dev::solidity::VersionString;
	set<string> requests;
	boost::split(requests, m_args["combined-json"].as<string>(), boost::is_any_of(","));
	vector<string> contracts = m_compiler->contractNames();

	if (!contracts.empty())
		output["contracts"] = Json::Value(Json::objectValue);
	for (string const& contractName: contracts)
	{
		Json::Value contractData(Json::objectValue);
		if (requests.count("abi"))
			contractData["abi"] = m_compiler->interface(contractName);
		if (requests.count("bin"))
			contractData["bin"] = m_compiler->object(contractName).toHex();
		if (requests.count("bin-runtime"))
			contractData["bin-runtime"] = m_compiler->runtimeObject(contractName).toHex();
		if (requests.count("clone-bin"))
			contractData["clone-bin"] = m_compiler->cloneObject(contractName).toHex();
		if (requests.count("opcodes"))
			contractData["opcodes"] = solidity::disassemble(m_compiler->object(contractName).bytecode);
		if (requests.count("asm"))
		{
			ostringstream unused;
			contractData["asm"] = m_compiler->streamAssembly(unused, contractName, m_sourceCodes, true);
		}
		if (requests.count("srcmap"))
		{
			auto map = m_compiler->sourceMapping(contractName);
			contractData["srcmap"] = map ? *map : "";
		}
		if (requests.count("srcmap-runtime"))
		{
			auto map = m_compiler->runtimeSourceMapping(contractName);
			contractData["srcmap-runtime"] = map ? *map : "";
		}
		if (requests.count("devdoc"))
			contractData["devdoc"] = m_compiler->metadata(contractName, DocumentationType::NatspecDev);
		if (requests.count("userdoc"))
			contractData["userdoc"] = m_compiler->metadata(contractName, DocumentationType::NatspecUser);
		output["contracts"][contractName] = contractData;
	}

	bool needsSourceList = requests.count("ast") || requests.count("srcmap") || requests.count("srcmap-runtime");
	if (needsSourceList)
	{
		// Indices into this array are used to abbreviate source names in source locations.
		output["sourceList"] = Json::Value(Json::arrayValue);

		for (auto const& source: m_compiler->sourceNames())
			output["sourceList"].append(source);
	}

	if (requests.count("ast"))
	{
		output["sources"] = Json::Value(Json::objectValue);
		for (auto const& sourceCode: m_sourceCodes)
		{
			ASTJsonConverter converter(m_compiler->ast(sourceCode.first), m_compiler->sourceIndices());
			output["sources"][sourceCode.first] = Json::Value(Json::objectValue);
			output["sources"][sourceCode.first]["AST"] = converter.json();
		}
	}
	cout << Json::FastWriter().write(output) << endl;
}

void CommandLineInterface::handleAst(string const& _argStr)
{
	string title;

	if (_argStr == g_argAstStr)
		title = "Syntax trees:";
	else if (_argStr == g_argAstJson)
		title = "JSON AST:";
	else
		BOOST_THROW_EXCEPTION(InternalCompilerError() << errinfo_comment("Illegal argStr for AST"));

	// do we need AST output?
	if (m_args.count(_argStr))
	{
		vector<ASTNode const*> asts;
		for (auto const& sourceCode: m_sourceCodes)
			asts.push_back(&m_compiler->ast(sourceCode.first));
		map<ASTNode const*, eth::GasMeter::GasConsumption> gasCosts;
		if (m_compiler->runtimeAssemblyItems())
			gasCosts = GasEstimator::breakToStatementLevel(
				GasEstimator::structuralEstimation(*m_compiler->runtimeAssemblyItems(), asts),
				asts
			);

		if (m_args.count("output-dir"))
		{
			for (auto const& sourceCode: m_sourceCodes)
			{
				stringstream data;
				string postfix = "";
				if (_argStr == g_argAstStr)
				{
					ASTPrinter printer(m_compiler->ast(sourceCode.first), sourceCode.second);
					printer.print(data);
				}
				else
				{
					ASTJsonConverter converter(m_compiler->ast(sourceCode.first));
					converter.print(data);
					postfix += "_json";
				}
				boost::filesystem::path path(sourceCode.first);
				createFile(path.filename().string() + postfix + ".ast", data.str());
			}
		}
		else
		{
			cout << title << endl << endl;
			for (auto const& sourceCode: m_sourceCodes)
			{
				cout << endl << "======= " << sourceCode.first << " =======" << endl;
				if (_argStr == g_argAstStr)
				{
					ASTPrinter printer(
						m_compiler->ast(sourceCode.first),
						sourceCode.second,
						gasCosts
					);
					printer.print(cout);
				}
				else
				{
					ASTJsonConverter converter(m_compiler->ast(sourceCode.first));
					converter.print(cout);
				}
			}
		}
	}
}

void CommandLineInterface::actOnInput()
{
	if (m_onlyAssemble)
		outputAssembly();
	else if (m_onlyLink)
		writeLinkedFiles();
	else
		outputCompilationResults();
}

bool CommandLineInterface::link()
{
	for (auto& src: m_sourceCodes)
	{
		auto end = src.second.end();
		for (auto it = src.second.begin(); it != end;)
		{
			while (it != end && *it != '_') ++it;
			auto insertStart = it;
			while (it != end && *it == '_') ++it;
			auto nameStart = it;
			while (it != end && *it != '_') ++it;
			auto nameEnd = it;
			while (it != end && *it == '_') ++it;
			auto insertEnd = it;

			if (insertStart == end)
				break;

			if (insertEnd - insertStart != 40)
			{
				cerr << "Error in binary object file " << src.first << " at position " << (insertStart - src.second.begin()) << endl;
				return false;
			}

			string name(nameStart, nameEnd);
			if (m_libraries.count(name))
			{
				string hexStr(toHex(m_libraries.at(name).asBytes()));
				copy(hexStr.begin(), hexStr.end(), insertStart);
			}
			else
				cerr << "Reference \"" << name << "\" in file \"" << src.first << "\" still unresolved." << endl;
		}
	}
	return true;
}

void CommandLineInterface::writeLinkedFiles()
{
	for (auto const& src: m_sourceCodes)
		if (src.first == g_stdinFileName)
			cout << src.second << endl;
		else
			writeFile(src.first, src.second);
}

bool CommandLineInterface::assemble()
{
	//@TODO later, we will use the convenience interface and should also remove the include above
	bool successful = true;
	map<string, shared_ptr<Scanner>> scanners;
	for (auto const& src: m_sourceCodes)
	{
		auto scanner = make_shared<Scanner>(CharStream(src.second), src.first);
		scanners[src.first] = scanner;
		if (!m_assemblyStacks[src.first].parse(scanner))
			successful = false;
		else
			//@TODO we should not just throw away the result here
			m_assemblyStacks[src.first].assemble();
	}
	for (auto const& stack: m_assemblyStacks)
		for (auto const& error: stack.second.errors())
			SourceReferenceFormatter::printExceptionInformation(
				cerr,
				*error,
				(error->type() == Error::Type::Warning) ? "Warning" : "Error",
				[&](string const& _source) -> Scanner const& { return *scanners.at(_source); }
			);

	return successful;
}

void CommandLineInterface::outputAssembly()
{
	for (auto const& src: m_sourceCodes)
	{
		cout << endl << "======= " << src.first << " =======" << endl;
		eth::Assembly assembly = m_assemblyStacks[src.first].assemble();
		cout << assembly.assemble().toHex() << endl;
		assembly.stream(cout, "", m_sourceCodes);
	}
}

void CommandLineInterface::outputCompilationResults()
{
	handleCombinedJSON();

	// do we need AST output?
	handleAst(g_argAstStr);
	handleAst(g_argAstJson);

	vector<string> contracts = m_compiler->contractNames();
	for (string const& contract: contracts)
	{
		if (needsHumanTargetedStdout(m_args))
			cout << endl << "======= " << contract << " =======" << endl;

		// do we need EVM assembly?
		if (m_args.count(g_argAsmStr) || m_args.count(g_argAsmJsonStr))
		{
			if (m_args.count("output-dir"))
			{
				stringstream data;
				m_compiler->streamAssembly(data, contract, m_sourceCodes, m_args.count(g_argAsmJsonStr));
				createFile(contract + (m_args.count(g_argAsmJsonStr) ? "_evm.json" : ".evm"), data.str());
			}
			else
			{
				cout << "EVM assembly:" << endl;
				m_compiler->streamAssembly(cout, contract, m_sourceCodes, m_args.count(g_argAsmJsonStr));
			}
		}

		if (m_args.count(g_argGas))
			handleGasEstimation(contract);

		handleBytecode(contract);
		handleSignatureHashes(contract);
		handleMeta(DocumentationType::ABIInterface, contract);
		handleMeta(DocumentationType::NatspecDev, contract);
		handleMeta(DocumentationType::NatspecUser, contract);
	} // end of contracts iteration

	handleFormal();
}

}
}