Adds documentation for Solidity source upgrader.

.circleci/config.yml

@@ -62,6 +62,11 @@ defaults:
       path: build/solc/solc
       destination: solc
 
+  # compiled tool executable target
+  - artifacts_tools: &artifacts_tools
+      path: build/tools/solidity-upgrade
+      destination: solidity-upgrade
+
   # compiled executable targets
   - artifacts_executables: &artifacts_executables
       root: build
@@ -324,6 +329,7 @@ jobs:
       - checkout
       - run: *run_build
       - store_artifacts: *artifacts_solc
+      - store_artifacts: *artifacts_tools
       - persist_to_workspace: *artifacts_executables
 
   b_ubu_release: &build_ubuntu1904_release
@@ -455,6 +461,7 @@ jobs:
             - /usr/local/Homebrew
       - run: *run_build
       - store_artifacts: *artifacts_solc
+      - store_artifacts: *artifacts_tools
       - persist_to_workspace: *artifacts_build_dir
 
   t_osx_soltest:

CMakeLists.txt

@@ -55,6 +55,7 @@ add_subdirectory(libevmasm)
 add_subdirectory(libyul)
 add_subdirectory(libsolidity)
 add_subdirectory(libsolc)
+add_subdirectory(tools)
 
 if (NOT EMSCRIPTEN)
 	add_subdirectory(solc)

docs/using-the-compiler.rst

@@ -474,3 +474,240 @@ Error types
 11. ``CompilerError``: Invalid use of the compiler stack - this should be reported as an issue.
 12. ``FatalError``: Fatal error not processed correctly - this should be reported as an issue.
 13. ``Warning``: A warning, which didn't stop the compilation, but should be addressed if possible.
+
+
+.. _compiler-tools:
+
+Compiler tools
+**************
+
+solidity-upgrade
+----------------
+
+``solidity-upgrade`` can help you to semi-automatically upgrade your contracts
+to breaking language changes. While it does not and cannot implement all
+required changes for every breaking release, it still supports the ones, that
+would need plenty of repetitive manual adjustments otherwise.
+
+.. note::
+
+    ``solidity-upgrade`` carries out a large part of the work, but your
+    contracts will most likely need further manual adjustments. We recommend
+    using a version control system for your files. This helps reviewing and
+    eventually rolling back the changes made.
+
+.. warning::
+
+    ``solidity-upgrade`` is not considered to be complete or free from bugs, so
+    please use with care.
+
+How it works
+~~~~~~~~~~~~
+
+You can pass (a) Solidity source file(s) to ``solidity-upgrade [files]``. If
+these make use of ``import`` statement which refer to files outside the
+current source file's directory, you need to specify directories that
+are allowed to read and import files from, by passing
+``--allow-paths [directory]``. You can ignore missing files by passing
+``--ignore-missing``.
+
+``solidity-upgrade`` is based on ``libsolidity`` and can parse, compile and
+analyse your source files, and might find applicable source upgrades in them.
+
+Source upgrades are considered to be small textual changes to your source code.
+They are applied to an in-memory representation of the source files
+given. The corresponding source file is updated by default, but you can pass
+``--dry-run`` to simulate to whole upgrade process without writing to any file.
+
+The upgrade process itself has two phases. In the first phase source files are
+parsed, and since it is not possible to upgrade source code on that level,
+errors are collected and can be logged by passing ``--verbose``. No source
+upgrades available at this point.
+
+In the second phase, all sources are compiled and all activated upgrade analysis
+modules are run alongside compilation. By default, all available modules are
+activated. Please read the documentation on
+:ref:`available modules <upgrade-modules>` for further details.
+
+
+This can result in compilation errors that may
+be fixed by source upgrades. If no errors occur, no source upgrades are being
+reported and you're done.
+If errors occur and some upgrade module reported a source upgrade, the first
+reported one gets applied and compilation is triggered again for all given
+source files. The previous step is repeated as long as source upgrades are
+reported. If errors still occur, you can log them by passing ``--verbose``.
+If no errors occur, your contracts are up to date and can be compiled with
+the latest version of the compiler.
+
+.. _upgrade-modules:
+
+Available upgrade modules
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
++-----------------+---------+--------------------------------------------------+
+| Module          | Version | Description                                      |
++=================+=========+==================================================+
+| ``constructor`` | 0.5.0   | Constructors must now be defined using the       |
+|                 |         | ``constructor`` keyword.                         |
++-----------------+---------+--------------------------------------------------+
+| ``visibility``  | 0.5.0   | Explicit function visibility is now mandatory,   |
+|                 |         | defaults to ``public``.                          |
++-----------------+---------+--------------------------------------------------+
+| ``abstract``    | 0.6.0   | The keyword ``abstract`` has to be used if a     |
+|                 |         | contract does not implement all its functions.   |
++-----------------+---------+--------------------------------------------------+
+| ``virtual``     | 0.6.0   | Functions without implementation outside an      |
+|                 |         | interface have to be marked ``virtual``.         |
++-----------------+---------+--------------------------------------------------+
+| ``override``    | 0.6.0   | When overriding a function or modifier, the new  |
+|                 |         | keyword ``override`` must be used.               |
++-----------------+---------+--------------------------------------------------+
+
+Please read :doc:`0.5.0 release notes <050-breaking-changes>` and
+:doc:`0.6.0 release notes <060-breaking-changes>` for further details.
+
+Synopsis
+~~~~~~~~
+
+.. code-block:: none
+
+    Usage: solidity-upgrade [options] contract.sol
+
+    Allowed options:
+        --help               Show help message and exit.
+        --version            Show version and exit.
+        --allow-paths path(s)
+                             Allow a given path for imports. A list of paths can be
+                             supplied by separating them with a comma.
+        --ignore-missing     Ignore missing files.
+        --modules module(s)  Only activate a specific upgrade module. A list of
+                             modules can be supplied by separating them with a comma.
+        --dry-run            Apply changes in-memory only and don't write to input
+                             file.
+        --verbose            Print logs, errors and changes. Shortens output of
+                             upgrade patches.
+        --unsafe             Accept *unsafe* changes.
+
+
+
+Bug Reports / Feature requests
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you found a bug or if you have a feature request, please
+`file an issue <https://github.com/ethereum/solidity/issues/new/choose>`_ on Github.
+
+
+Example
+~~~~~~~
+
+Assume you have the following contracts you want to update declared in ``Source.sol``:
+
+.. code-block:: none
+
+    // This will not compile
+    pragma solidity >0.4.23;
+
+    contract Updateable {
+        function run() public view returns (bool);
+        function update() public;
+    }
+
+    contract Upgradable {
+        function run() public view returns (bool);
+        function upgrade();
+    }
+
+    contract Source is Updateable, Upgradable {
+        function Source() public {}
+
+        function run()
+            public
+            view
+            returns (bool) {}
+
+        function update() {}
+        function upgrade() {}
+    }
+
+
+Required changes
+^^^^^^^^^^^^^^^^
+
+To bring the contracts up to date with the current Solidity version, the
+following upgrade modules have to be executed: ``constructor``,
+``visibility``, ``abstract``, ``override`` and ``virtual``. Please read the
+documentation on :ref:`available modules <upgrade-modules>` for further details.
+
+Running the upgrade
+^^^^^^^^^^^^^^^^^^^
+
+In this example, all modules needed to upgrade the contracts above,
+are available and all of them are activated by default. Therefore you
+do not need to specify the ``--modules`` option.
+
+.. code-block:: none
+
+    $ solidity-upgrade Source.sol --dry-run
+
+.. code-block:: none
+
+    Running analysis (and upgrade) on given source files.
+    ..............
+
+    After upgrade:
+
+    Found 0 errors.
+    Found 0 upgrades.
+
+The above performs a dry-ran upgrade on the given file and logs statistics after all.
+In this case, the upgrade was successful and no further adjustments are needed.
+
+Finally, you can run the upgrade and also write to the source file.
+
+.. code-block:: none
+
+    $ solidity-upgrade Source.sol
+
+.. code-block:: none
+
+    Running analysis (and upgrade) on given source files.
+    ..............
+
+    After upgrade:
+
+    Found 0 errors.
+    Found 0 upgrades.
+
+
+Review changes
+^^^^^^^^^^^^^^
+
+The command above applies all changes as shown below. Please review them carefully.
+
+.. code-block:: none
+
+    pragma solidity >0.4.23;
+
+    abstract contract Updateable {
+        function run() public view virtual returns (bool);
+        function update() public virtual;
+    }
+
+    abstract contract Upgradable {
+        function run() public view virtual returns (bool);
+        function upgrade() public virtual;
+    }
+
+    contract Source is Updateable, Upgradable {
+        constructor() public {}
+
+        function run()
+            public
+            view
+            override(Updateable,Upgradable)
+            returns (bool) {}
+
+        function update() public override {}
+        function upgrade() public override {}
+    }

libsolidity/analysis/OverrideChecker.cpp

@@ -144,8 +144,8 @@ vector<ContractDefinition const*> resolveDirectBaseContracts(ContractDefinition
 		Declaration const* baseDecl =
 			specifier->name().annotation().referencedDeclaration;
 		auto contract = dynamic_cast<ContractDefinition const*>(baseDecl);
-		solAssert(contract, "contract is null");
+		if (contract)
-		resolvedContracts.emplace_back(contract);
+			resolvedContracts.emplace_back(contract);
 	}
 
 	return resolvedContracts;

libsolidity/analysis/OverrideChecker.h

@@ -129,6 +129,7 @@ private:
 class OverrideChecker
 {
 public:
+	using OverrideProxyBySignatureMultiSet = std::multiset<OverrideProxy, OverrideProxy::CompareBySignature>;
 
 	/// @param _errorReporter provides the error logging functionality.
 	explicit OverrideChecker(langutil::ErrorReporter& _errorReporter):
@@ -137,12 +138,17 @@ public:
 
 	void check(ContractDefinition const& _contract);
 
-private:
 	struct CompareByID
 	{
 		bool operator()(ContractDefinition const* _a, ContractDefinition const* _b) const;
 	};
 
+	/// Returns all functions of bases (including public state variables) that have not yet been overwritten.
+	/// May contain the same function multiple times when used with shared bases.
+	OverrideProxyBySignatureMultiSet const& inheritedFunctions(ContractDefinition const& _contract) const;
+	OverrideProxyBySignatureMultiSet const& inheritedModifiers(ContractDefinition const& _contract) const;
+
+private:
 	void checkIllegalOverrides(ContractDefinition const& _contract);
 	/// Performs various checks related to @a _overriding overriding @a _super like
 	/// different return type, invalid visibility change, etc.
@@ -174,15 +180,8 @@ private:
 	/// Resolves an override list of UserDefinedTypeNames to a list of contracts.
 	std::set<ContractDefinition const*, CompareByID> resolveOverrideList(OverrideSpecifier const& _overrides) const;
 
-	using OverrideProxyBySignatureMultiSet = std::multiset<OverrideProxy, OverrideProxy::CompareBySignature>;
-
 	void checkOverrideList(OverrideProxy _item, OverrideProxyBySignatureMultiSet const& _inherited);
 
-	/// Returns all functions of bases (including public state variables) that have not yet been overwritten.
-	/// May contain the same function multiple times when used with shared bases.
-	OverrideProxyBySignatureMultiSet const& inheritedFunctions(ContractDefinition const& _contract) const;
-	OverrideProxyBySignatureMultiSet const& inheritedModifiers(ContractDefinition const& _contract) const;
-
 	langutil::ErrorReporter& m_errorReporter;
 
 	/// Cache for inheritedFunctions().

libsolidity/ast/AST.h

@@ -797,7 +797,7 @@ public:
 	{
 		return
 			CallableDeclaration::virtualSemantics() ||
-			annotation().contract->isInterface();
+			(annotation().contract && annotation().contract->isInterface());
 	}
 private:
 	StateMutability m_stateMutability;

tools/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_executable(solidity-upgrade
+    solidityUpgrade/main.cpp
+    solidityUpgrade/UpgradeChange.h
+    solidityUpgrade/UpgradeChange.cpp
+    solidityUpgrade/UpgradeSuite.h
+    solidityUpgrade/Upgrade050.cpp
+    solidityUpgrade/Upgrade060.cpp
+    solidityUpgrade/SourceTransform.h
+    solidityUpgrade/SourceUpgrade.cpp
+)
+target_link_libraries(solidity-upgrade PRIVATE solidity Boost::boost Boost::program_options Boost::system)
+
+include(GNUInstallDirs)
+install(TARGETS solidity-upgrade DESTINATION "${CMAKE_INSTALL_BINDIR}")

tools/solidityUpgrade/SourceTransform.h

@@ -0,0 +1,159 @@
+/*
+	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 <libsolidity/analysis/OverrideChecker.h>
+
+#include <libsolidity/ast/AST.h>
+
+#include <regex>
+
+namespace solidity::tools
+{
+
+/**
+ * Helper that provides functions which analyze certain source locations
+ * on a textual base. They utilize regular expression to search for
+ * keywords or to determine formatting.
+ */
+class SourceAnalysis {
+public:
+	static bool isMultilineKeyword(
+		langutil::SourceLocation const& _location,
+		std::string const& _keyword
+	)
+	{
+		return regex_search(
+			_location.text(),
+			std::regex{"(\\b" + _keyword + "\\b\\n|\\r|\\r\\n)"}
+		);
+	}
+
+	static bool hasMutabilityKeyword(langutil::SourceLocation const& _location)
+	{
+		return regex_search(
+			_location.text(),
+			std::regex{"(\\b(pure|view|nonpayable|payable)\\b)"}
+		);
+	}
+
+	static bool hasVirtualKeyword(langutil::SourceLocation const& _location)
+	{
+		return regex_search(_location.text(), std::regex{"(\\b(virtual)\\b)"});
+	}
+
+	static bool hasVisibilityKeyword(langutil::SourceLocation const& _location)
+	{
+		return regex_search(_location.text(), std::regex{"\\bpublic\\b"});
+	}
+};
+
+/**
+ * Helper that provides functions which can analyse declarations and
+ * generate source snippets based on the information retrieved.
+ */
+class SourceGeneration
+{
+public:
+	using CompareFunction = frontend::OverrideChecker::CompareByID;
+	using Contracts = std::set<frontend::ContractDefinition const*, CompareFunction>;
+
+	/// Generates an `override` declaration for single overrides
+	/// or `override(...)` with contract list for multiple overrides.
+	static std::string functionOverride(Contracts const& _contracts)
+	{
+		if (_contracts.size() <= 1)
+			return "override";
+
+		std::string overrideList;
+		for (auto inheritedContract: _contracts)
+			overrideList += inheritedContract->name() + ",";
+
+		return "override(" + overrideList.substr(0, overrideList.size() - 1) + ")";
+	}
+};
+
+/**
+ * Helper that provides functions which apply changes to Solidity source code
+ * on a textual base. In general, these utilize regular expressions applied
+ * to the given source location.
+ */
+class SourceTransform
+{
+public:
+	/// Searches for the keyword given and prepends the expression.
+	/// E.g. `function f() view;` -> `function f() public view;`
+	static std::string insertBeforeKeyword(
+		langutil::SourceLocation const& _location,
+		std::string const& _keyword,
+		std::string const& _expression
+	)
+	{
+		return regex_replace(
+			_location.text(),
+			std::regex{"(\\b" + _keyword + "\\b)"},
+			_expression + " " + _keyword
+		);
+	}
+
+	/// Searches for the keyword given and appends the expression.
+	/// E.g. `function f() public {}` -> `function f() public override {}`
+	static std::string insertAfterKeyword(
+		langutil::SourceLocation const& _location,
+		std::string const& _keyword,
+		std::string const& _expression
+	)
+	{
+		bool isMultiline = SourceAnalysis::isMultilineKeyword(_location, _keyword);
+		std::string toAppend = isMultiline ? ("\n        " + _expression) : (" " + _expression);
+		std::regex keyword{"(\\b" + _keyword + "\\b)"};
+
+		return regex_replace(_location.text(), keyword, _keyword + toAppend);
+	}
+
+	/// Searches for the first right parenthesis and appends the expression
+	/// given.
+	/// E.g. `function f() {}` -> `function f() public {}`
+	static std::string insertAfterRightParenthesis(
+		langutil::SourceLocation const& _location,
+		std::string const& _expression
+	)
+	{
+		return regex_replace(
+			_location.text(),
+			std::regex{"(\\))"},
+			") " + _expression
+		);
+	}
+
+	/// Searches for the `function` keyword and its identifier and replaces
+	/// both by the expression given.
+	/// E.g. `function Storage() {}` -> `constructor() {}`
+	static std::string replaceFunctionName(
+		langutil::SourceLocation const& _location,
+		std::string const& _name,
+		std::string const& _expression
+	)
+	{
+		return regex_replace(
+			_location.text(),
+			std::regex{"(\\bfunction\\s*" + _name + "\\b)"},
+			_expression
+		);
+	}
+};
+
+}

tools/solidityUpgrade/SourceUpgrade.cpp

@@ -0,0 +1,525 @@
+/*
+	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 <tools/solidityUpgrade/SourceUpgrade.h>
+
+#include <liblangutil/Exceptions.h>
+#include <liblangutil/SourceReferenceFormatterHuman.h>
+
+#include <libsolidity/ast/AST.h>
+
+#include <boost/filesystem.hpp>
+#include <boost/filesystem/operations.hpp>
+#include <boost/algorithm/string.hpp>
+
+namespace po = boost::program_options;
+namespace fs = boost::filesystem;
+
+using namespace solidity;
+using namespace solidity::langutil;
+using namespace solidity::tools;
+using namespace solidity::util;
+using namespace solidity::frontend;
+using namespace std;
+
+
+static string const g_argHelp = "help";
+static string const g_argVersion = "version";
+static string const g_argInputFile = "input-file";
+static string const g_argModules = "modules";
+static string const g_argDryRun = "dry-run";
+static string const g_argUnsafe = "unsafe";
+static string const g_argVerbose = "verbose";
+static string const g_argIgnoreMissingFiles = "ignore-missing";
+static string const g_argAllowPaths = "allow-paths";
+
+namespace
+{
+
+ostream& out()
+{
+	return cout;
+}
+
+AnsiColorized log()
+{
+	return AnsiColorized(cout, true, {});
+}
+
+AnsiColorized success()
+{
+	return AnsiColorized(cout, true, {formatting::CYAN});
+}
+
+AnsiColorized warning()
+{
+	return AnsiColorized(cout, true, {formatting::YELLOW});
+}
+
+AnsiColorized error()
+{
+	return AnsiColorized(cout, true, {formatting::MAGENTA});
+}
+
+void logVersion()
+{
+	/// TODO Replace by variable that can be set during build.
+	out() << "0.1.0" << endl;
+}
+
+void logProgress()
+{
+	out() << ".";
+	out().flush();
+}
+
+}
+
+bool SourceUpgrade::parseArguments(int _argc, char** _argv)
+{
+	po::options_description desc(R"(solidity-upgrade, the Solidity upgrade assistant.
+
+The solidity-upgrade tool can help upgrade smart contracts to breaking language features.
+
+It does not support all breaking changes for each version, but will hopefully assist
+upgrading your contracts to the desired Solidity version.
+
+solidity-upgrade is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY. Please be careful when running upgrades on
+your contracts.
+
+Usage: solidity-upgrade [options] contract.sol
+
+Allowed options)",
+		po::options_description::m_default_line_length,
+		po::options_description::m_default_line_length - 23
+	);
+	desc.add_options()
+		(g_argHelp.c_str(), "Show help message and exit.")
+		(g_argVersion.c_str(), "Show version and exit.")
+		(
+			g_argAllowPaths.c_str(),
+			po::value<string>()->value_name("path(s)"),
+			"Allow a given path for imports. A list of paths can be supplied by separating them "
+			"with a comma."
+		)
+		(g_argIgnoreMissingFiles.c_str(), "Ignore missing files.")
+		(
+			g_argModules.c_str(),
+			po::value<string>()->value_name("module(s)"),
+			"Only activate a specific upgrade module. A list of "
+			"modules can be supplied by separating them with a comma."
+		)
+		(g_argDryRun.c_str(), "Apply changes in-memory only and don't write to input file.")
+		(g_argVerbose.c_str(), "Print logs, errors and changes. Shortens output of upgrade patches.")
+		(g_argUnsafe.c_str(), "Accept *unsafe* changes.");
+
+
+	po::options_description allOptions = desc;
+	allOptions.add_options()("input-file", po::value<vector<string>>(), "input file");
+
+	po::positional_options_description filesPositions;
+	filesPositions.add("input-file", -1);
+
+	// parse the compiler arguments
+	try
+	{
+		po::command_line_parser cmdLineParser(_argc, _argv);
+		cmdLineParser.style(
+			po::command_line_style::default_style & (~po::command_line_style::allow_guessing)
+		);
+		cmdLineParser.options(allOptions).positional(filesPositions);
+		po::store(cmdLineParser.run(), m_args);
+	}
+	catch (po::error const& _exception)
+	{
+		error() << _exception.what() << endl;
+		return false;
+	}
+
+	if (m_args.count(g_argHelp) || (isatty(fileno(stdin)) && _argc == 1))
+	{
+		out() << endl;
+		log() << desc;
+		return false;
+	}
+
+	if (m_args.count(g_argVersion))
+	{
+		logVersion();
+		return false;
+	}
+
+	if (m_args.count(g_argModules))
+	{
+		vector<string> moduleArgs;
+		auto modules = boost::split(
+			moduleArgs, m_args[g_argModules].as<string>(), boost::is_any_of(",")
+		);
+
+		/// All modules are activated by default. Clear them before activating single ones.
+		m_suite.deactivateModules();
+
+		for (string const& module: modules)
+		{
+			if (module == "constructor")
+				m_suite.activateModule(Module::ConstructorKeyword);
+			else if (module == "visibility")
+				m_suite.activateModule(Module::VisibilitySpecifier);
+			else if (module == "abstract")
+				m_suite.activateModule(Module::AbstractContract);
+			else if (module == "override")
+				m_suite.activateModule(Module::OverridingFunction);
+			else if (module == "virtual")
+				m_suite.activateModule(Module::VirtualFunction);
+			else
+			{
+				error() << "Unknown upgrade module \"" + module + "\"" << endl;
+				return false;
+			}
+		}
+	}
+
+	/// TODO Share with solc commandline interface.
+	if (m_args.count(g_argAllowPaths))
+	{
+		vector<string> paths;
+		auto allowedPaths = boost::split(
+			paths, m_args[g_argAllowPaths].as<string>(), boost::is_any_of(",")
+		);
+		for (string const& path: allowedPaths)
+		{
+			auto filesystem_path = boost::filesystem::path(path);
+			/// If the given path had a trailing slash, the Boost filesystem
+			/// path will have it's last component set to '.'. This breaks
+			/// path comparison in later parts of the code, so we need to strip
+			/// it.
+			if (filesystem_path.filename() == ".")
+				filesystem_path.remove_filename();
+			m_allowedDirectories.push_back(filesystem_path);
+		}
+	}
+
+
+	return true;
+}
+
+void SourceUpgrade::printPrologue()
+{
+	out() << endl;
+	out() << endl;
+
+	log() <<
+		"solidity-upgrade does not support all breaking changes for each version." <<
+		endl <<
+		"Please run `solidity-upgrade --help` and get a list of implemented upgrades." <<
+		endl <<
+		endl;
+
+	log() <<
+		"Running analysis (and upgrade) on given source files." <<
+		endl;
+}
+
+bool SourceUpgrade::processInput()
+{
+	if (!readInputFiles())
+		return false;
+
+	resetCompiler(fileReader());
+
+	tryCompile();
+	runUpgrade();
+
+	printStatistics();
+
+	return true;
+}
+
+void SourceUpgrade::tryCompile() const
+{
+	bool verbose = m_args.count(g_argVerbose);
+
+	if (verbose)
+		log() << "Running compilation phases." << endl << endl;
+	else
+		logProgress();
+
+	try
+	{
+		if (m_compiler->parse())
+		{
+			if (m_compiler->analyze())
+				m_compiler->compile();
+			else
+				if (verbose)
+				{
+					error() <<
+						"Compilation errors that solidity-upgrade may resolve occurred." <<
+						endl <<
+						endl;
+
+					printErrors();
+				}
+		}
+		else
+			if (verbose)
+			{
+				error() <<
+					"Compilation errors that solidity-upgrade cannot resolve occurred." <<
+					endl <<
+					endl;
+
+				printErrors();
+			}
+	}
+	catch (Exception const& _exception)
+	{
+		error() << "Exception during compilation: " << boost::diagnostic_information(_exception) << endl;
+	}
+	catch (std::exception const& _e)
+	{
+		error() << (_e.what() ? ": " + string(_e.what()) : ".") << endl;
+	}
+	catch (...)
+	{
+		error() << "Unknown exception during compilation." << endl;
+	}
+}
+
+void SourceUpgrade::runUpgrade()
+{
+	bool recompile = true;
+
+	while (recompile && !m_compiler->errors().empty())
+	{
+		for (auto& sourceCode: m_sourceCodes)
+		{
+			recompile = analyzeAndUpgrade(sourceCode);
+			if (recompile)
+				break;
+		}
+
+		if (recompile)
+		{
+			m_suite.reset();
+			resetCompiler();
+			tryCompile();
+		}
+	}
+}
+
+bool SourceUpgrade::analyzeAndUpgrade(pair<string, string> const& _sourceCode)
+{
+	bool applyUnsafe = m_args.count(g_argUnsafe);
+	bool verbose = m_args.count(g_argVerbose);
+
+	if (verbose)
+		log() << "Analyzing and upgrading " << _sourceCode.first << "." << endl;
+
+	if (m_compiler->state() >= CompilerStack::State::AnalysisPerformed)
+		m_suite.analyze(m_compiler->ast(_sourceCode.first));
+
+	if (!m_suite.changes().empty())
+	{
+		auto& change = m_suite.changes().front();
+
+		if (verbose)
+			change.log(true);
+
+		if (change.level() == UpgradeChange::Level::Safe)
+		{
+			applyChange(_sourceCode, change);
+			return true;
+		}
+		else if (change.level() == UpgradeChange::Level::Unsafe)
+		{
+			if (applyUnsafe)
+			{
+				applyChange(_sourceCode, change);
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+void SourceUpgrade::applyChange(
+	pair<string, string> const& _sourceCode,
+	UpgradeChange& _change
+)
+{
+	bool dryRun = m_args.count(g_argDryRun);
+	bool verbose = m_args.count(g_argVerbose);
+
+	if (verbose)
+	{
+		log() << "Applying change to " << _sourceCode.first << endl << endl;
+		log() << _change.patch();
+	}
+
+	_change.apply();
+	m_sourceCodes[_sourceCode.first] = _change.source();
+
+	if (!dryRun)
+		writeInputFile(_sourceCode.first, _change.source());
+}
+
+void SourceUpgrade::printErrors() const
+{
+	auto formatter = make_unique<langutil::SourceReferenceFormatterHuman>(cout, true);
+
+	for (auto const& error: m_compiler->errors())
+		if (error->type() != langutil::Error::Type::Warning)
+			formatter->printErrorInformation(*error);
+}
+
+void SourceUpgrade::printStatistics() const
+{
+	out() << endl;
+	out() << endl;
+	out() << "After upgrade:" << endl;
+	out() << endl;
+	error() << "Found " << m_compiler->errors().size() << " errors." << endl;
+	success() << "Found " << m_suite.changes().size() << " upgrades." << endl;
+}
+
+bool SourceUpgrade::readInputFiles()
+{
+	bool ignoreMissing = m_args.count(g_argIgnoreMissingFiles);
+
+	/// TODO Share with solc commandline interface.
+	if (m_args.count(g_argInputFile))
+		for (string path: m_args[g_argInputFile].as<vector<string>>())
+		{
+			auto infile = boost::filesystem::path(path);
+			if (!boost::filesystem::exists(infile))
+			{
+				if (!ignoreMissing)
+				{
+					error() << infile << " is not found." << endl;
+					return false;
+				}
+				else
+					error() << infile << " is not found. Skipping." << endl;
+
+				continue;
+			}
+
+			if (!boost::filesystem::is_regular_file(infile))
+			{
+				if (!ignoreMissing)
+				{
+					error() << infile << " is not a valid file." << endl;
+					return false;
+				}
+				else
+					error() << infile << " is not a valid file. Skipping." << endl;
+
+				continue;
+			}
+
+			m_sourceCodes[infile.generic_string()] = readFileAsString(infile.string());
+			path = boost::filesystem::canonical(infile).string();
+		}
+
+	if (m_sourceCodes.size() == 0)
+	{
+		warning() << "No input files given. If you wish to use the standard input please specify \"-\" explicitly." << endl;
+		return false;
+	}
+
+	return true;
+}
+
+bool SourceUpgrade::writeInputFile(string const& _path, string const& _source)
+{
+	bool verbose = m_args.count(g_argVerbose);
+
+	if (verbose)
+	{
+		out() << endl;
+		log() << "Writing to input file " << _path << "." << endl;
+	}
+
+	ofstream file(_path, ios::trunc);
+	file << _source;
+
+	return true;
+}
+
+ReadCallback::Callback SourceUpgrade::fileReader()
+{
+	/// TODO Share with solc commandline interface.
+	ReadCallback::Callback fileReader = [this](string const&, string const& _path)
+	{
+		try
+		{
+			auto path = boost::filesystem::path(_path);
+			auto canonicalPath = boost::filesystem::weakly_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 ReadCallback::Result{false, "File outside of allowed directories."};
+
+			if (!boost::filesystem::exists(canonicalPath))
+				return ReadCallback::Result{false, "File not found."};
+
+			if (!boost::filesystem::is_regular_file(canonicalPath))
+				return ReadCallback::Result{false, "Not a valid file."};
+
+			auto contents = readFileAsString(canonicalPath.string());
+			m_sourceCodes[path.generic_string()] = contents;
+			return ReadCallback::Result{true, contents};
+		}
+		catch (Exception const& _exception)
+		{
+			return ReadCallback::Result{false, "Exception in read callback: " + boost::diagnostic_information(_exception)};
+		}
+		catch (...)
+		{
+			return ReadCallback::Result{false, "Unknown exception in read callback."};
+		}
+	};
+
+	return fileReader;
+}
+
+void SourceUpgrade::resetCompiler()
+{
+	m_compiler->reset();
+	m_compiler->setSources(m_sourceCodes);
+	m_compiler->setParserErrorRecovery(true);
+}
+
+void SourceUpgrade::resetCompiler(ReadCallback::Callback const& _callback)
+{
+	m_compiler.reset(new CompilerStack(_callback));
+	m_compiler->setSources(m_sourceCodes);
+	m_compiler->setParserErrorRecovery(true);
+}

tools/solidityUpgrade/SourceUpgrade.h

@@ -0,0 +1,158 @@
+/*
+	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 <tools/solidityUpgrade/UpgradeChange.h>
+#include <tools/solidityUpgrade/Upgrade050.h>
+#include <tools/solidityUpgrade/Upgrade060.h>
+
+#include <libsolidity/interface/CompilerStack.h>
+#include <libsolidity/interface/DebugSettings.h>
+#include <libyul/AssemblyStack.h>
+#include <liblangutil/EVMVersion.h>
+
+#include <boost/program_options.hpp>
+#include <boost/filesystem/path.hpp>
+
+#include <memory>
+
+namespace solidity::tools
+{
+
+/**
+ * The Solidity source upgrade tool. It supplies a command line interface
+ * and connects this to a compiler stack that the upgrade logic is facilitated
+ * with.
+ */
+class SourceUpgrade
+{
+public:
+	/// Parse command line arguments and return false in case of a failure.
+	bool parseArguments(int _argc, char** _argv);
+	/// Prints additional information on the upgrade tool.
+	void printPrologue();
+	/// Parse / compile files and runs upgrade analysis on them.
+	bool processInput();
+
+private:
+	/// All available upgrade modules
+	enum class Module
+	{
+		ConstructorKeyword,
+		VisibilitySpecifier,
+		AbstractContract,
+		OverridingFunction,
+		VirtualFunction
+	};
+
+	/// Upgrade suite that hosts all available modules.
+	class Suite: public UpgradeSuite
+	{
+	public:
+		void analyze(frontend::SourceUnit const& _sourceUnit)
+		{
+			/// Solidity 0.5.0
+			if (isActivated(Module::ConstructorKeyword))
+				ConstructorKeyword{m_changes}.analyze(_sourceUnit);
+			if (isActivated(Module::VisibilitySpecifier))
+				VisibilitySpecifier{m_changes}.analyze(_sourceUnit);
+
+			/// Solidity 0.6.0
+			if (isActivated(Module::AbstractContract))
+				AbstractContract{m_changes}.analyze(_sourceUnit);
+			if (isActivated(Module::OverridingFunction))
+				OverridingFunction{m_changes}.analyze(_sourceUnit);
+			if (isActivated(Module::VirtualFunction))
+				VirtualFunction{m_changes}.analyze(_sourceUnit);
+		}
+
+		void activateModule(Module _module) { m_modules.insert(_module); }
+		void deactivateModules() { m_modules.clear(); }
+
+	private:
+		bool isActivated(Module _module) const
+		{
+			return m_modules.find(_module) != m_modules.end();
+		}
+
+		/// All modules are activated by default. Clear them before activating
+		/// single ones.
+		std::set<Module> m_modules = {
+			Module::ConstructorKeyword,
+			Module::VisibilitySpecifier,
+			Module::AbstractContract,
+			Module::OverridingFunction,
+			Module::VirtualFunction
+		};
+	};
+
+	/// Parses the current sources and runs analyses as well as compilation on
+	/// them if parsing was successful.
+	void tryCompile() const;
+	/// Analyses and upgrades the sources given. The upgrade happens in a loop,
+	/// applying one change at a time, which is run until no applicable changes
+	/// are found any more. Only one change is done at a time and all sources
+	/// are being compiled again after each change.
+	void runUpgrade();
+	/// Runs upgrade analysis on source and applies upgrades changes to it.
+	/// Returns `true` if there're still changes that can be applied,
+	/// `false` otherwise.
+	bool analyzeAndUpgrade(
+		std::pair<std::string, std::string> const& _sourceCode
+	);
+
+	/// Applies the change given to its source code. If no `--dry-run` was
+	/// passed via the commandline, the upgraded source code is written back
+	/// to its file.
+	void applyChange(
+		std::pair<std::string, std::string> const& _sourceCode,
+		UpgradeChange& _change
+	);
+
+	/// Prints all errors (excluding warnings) the compiler currently reported.
+	void printErrors() const;
+	/// Prints error and upgrade overview at the end of each full run.
+	void printStatistics() const;
+
+	/// Reads all input files given and stores sources in the internal data
+	/// structure. Reports errors if files cannot be found.
+	bool readInputFiles();
+	/// Writes source to file given.
+	bool writeInputFile(std::string const& _path, std::string const& _source);
+	/// Returns a file reader function that fills `m_sources`.
+	frontend::ReadCallback::Callback fileReader();
+
+	/// Resets the compiler stack and configures sources to compile.
+	/// Also enables error recovery.
+	void resetCompiler();
+	/// Resets the compiler stack and configures sources to compile.
+	/// Also enables error recovery. Passes read callback to the compiler stack.
+	void resetCompiler(frontend::ReadCallback::Callback const& _callback);
+
+	/// Compiler arguments variable map
+	boost::program_options::variables_map m_args;
+	/// Map of input files to source code strings
+	std::map<std::string, std::string> m_sourceCodes;
+	/// Solidity compiler stack
+	std::unique_ptr<frontend::CompilerStack> m_compiler;
+	/// List of allowed directories to read files from
+	std::vector<boost::filesystem::path> m_allowedDirectories;
+	/// Holds all upgrade modules and source upgrades.
+	Suite m_suite;
+};
+
+}

tools/solidityUpgrade/Upgrade050.cpp

@@ -0,0 +1,58 @@
+/*
+	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 <tools/solidityUpgrade/Upgrade050.h>
+#include <tools/solidityUpgrade/SourceTransform.h>
+
+#include <libsolidity/analysis/OverrideChecker.h>
+
+#include <libyul/AsmData.h>
+
+#include <regex>
+
+using namespace std;
+using namespace solidity;
+using namespace solidity::frontend;
+using namespace solidity::tools;
+
+void ConstructorKeyword::endVisit(ContractDefinition const& _contract)
+{
+	for (auto const* function: _contract.definedFunctions())
+		if (function->name() == _contract.name())
+			m_changes.push_back(
+				UpgradeChange{
+					UpgradeChange::Level::Safe,
+					function->location(),
+					SourceTransform::replaceFunctionName(
+						function->location(),
+						function->name(),
+						"constructor"
+					)
+				}
+			);
+}
+
+void VisibilitySpecifier::endVisit(FunctionDefinition const& _function)
+{
+	if (_function.noVisibilitySpecified())
+		m_changes.push_back(
+			UpgradeChange{
+				UpgradeChange::Level::Safe,
+				_function.location(),
+				SourceTransform::insertAfterRightParenthesis(_function.location(), "public")
+			}
+		);
+}

tools/solidityUpgrade/Upgrade050.h

@@ -0,0 +1,58 @@
+/*
+	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 <tools/solidityUpgrade/UpgradeChange.h>
+#include <tools/solidityUpgrade/UpgradeSuite.h>
+
+#include <libsolidity/ast/ASTVisitor.h>
+
+namespace solidity::tools
+{
+
+/**
+ * Module that performs analysis on the AST. It visits all contract
+ * definitions and its defined functions and reports a source upgrade,
+ * if one of the declared functions is the constructor but does not
+ * use the `constructor` keyword.
+ */
+class ConstructorKeyword: public AnalysisUpgrade
+{
+public:
+	using AnalysisUpgrade::AnalysisUpgrade;
+
+	void analyze(frontend::SourceUnit const& _sourceUnit) { _sourceUnit.accept(*this); }
+private:
+	void endVisit(frontend::ContractDefinition const& _contract);
+};
+
+/**
+ * Module that performs analysis on the AST. It visits function definitions
+ * and reports a source upgrade, if this function's visibility is `public`,
+ * but not marked explicitly as such.
+ */
+class VisibilitySpecifier: public AnalysisUpgrade
+{
+public:
+	using AnalysisUpgrade::AnalysisUpgrade;
+
+	void analyze(frontend::SourceUnit const& _sourceUnit) { _sourceUnit.accept(*this); }
+private:
+	void endVisit(frontend::FunctionDefinition const& _function);
+};
+
+}

tools/solidityUpgrade/Upgrade060.cpp

@@ -0,0 +1,212 @@
+/*
+	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 <tools/solidityUpgrade/Upgrade060.h>
+#include <tools/solidityUpgrade/SourceTransform.h>
+
+#include <libsolidity/analysis/OverrideChecker.h>
+
+#include <libyul/AsmData.h>
+
+#include <regex>
+
+using namespace std;
+using namespace solidity;
+using namespace solidity::frontend;
+using namespace solidity::tools;
+
+using Contracts = set<ContractDefinition const*, OverrideChecker::CompareByID>;
+
+namespace
+{
+
+inline string appendOverride(
+	FunctionDefinition const& _function,
+	Contracts const& _expectedContracts
+)
+{
+	auto location = _function.location();
+	string upgradedCode;
+	string overrideExpression = SourceGeneration::functionOverride(_expectedContracts);
+
+	if (SourceAnalysis::hasVirtualKeyword(location))
+		upgradedCode = SourceTransform::insertAfterKeyword(
+			location,
+			"virtual",
+			overrideExpression
+		);
+	else if (SourceAnalysis::hasMutabilityKeyword(location))
+		upgradedCode = SourceTransform::insertAfterKeyword(
+			location,
+			stateMutabilityToString(_function.stateMutability()),
+			overrideExpression
+		);
+	else if (SourceAnalysis::hasVisibilityKeyword(location))
+		upgradedCode = SourceTransform::insertAfterKeyword(
+			location,
+			Declaration::visibilityToString(_function.visibility()),
+			overrideExpression
+		);
+	else
+		upgradedCode = SourceTransform::insertAfterRightParenthesis(
+			location,
+			overrideExpression
+		);
+
+	return upgradedCode;
+}
+
+inline string appendVirtual(FunctionDefinition const& _function)
+{
+	auto location = _function.location();
+	string upgradedCode;
+
+	if (SourceAnalysis::hasMutabilityKeyword(location))
+		upgradedCode = SourceTransform::insertAfterKeyword(
+			location,
+			stateMutabilityToString(_function.stateMutability()),
+			"virtual"
+		);
+	else if (SourceAnalysis::hasVisibilityKeyword(location))
+		upgradedCode = SourceTransform::insertAfterKeyword(
+			location,
+			Declaration::visibilityToString(_function.visibility()),
+			"virtual"
+		);
+	else
+		upgradedCode = SourceTransform::insertAfterRightParenthesis(
+			_function.location(),
+			"virtual"
+		);
+
+	return upgradedCode;
+}
+
+}
+
+void AbstractContract::endVisit(ContractDefinition const& _contract)
+{
+	bool isFullyImplemented = _contract.annotation().unimplementedFunctions.empty();
+
+	if (
+		!isFullyImplemented &&
+		!_contract.abstract() &&
+		!_contract.isInterface()
+	)
+		m_changes.push_back(
+			UpgradeChange{
+				UpgradeChange::Level::Safe,
+				_contract.location(),
+				SourceTransform::insertBeforeKeyword(_contract.location(), "contract", "abstract")
+			}
+		);
+}
+
+void OverridingFunction::endVisit(ContractDefinition const& _contract)
+{
+	auto const& inheritedFunctions = m_overrideChecker.inheritedFunctions(_contract);
+
+	for (auto const* function: _contract.definedFunctions())
+	{
+		Contracts expectedContracts;
+		OverrideProxy proxy{function};
+
+		if (!function->isConstructor())
+		{
+			/// Build list of contracts expected to be mentioned in the override list (if any).
+			for (auto [begin, end] = inheritedFunctions.equal_range(proxy); begin != end; begin++)
+				expectedContracts.insert(&begin->contract());
+
+			/// Add override with contract list, if needed.
+			if (!function->overrides() && expectedContracts.size() > 1)
+				m_changes.push_back(
+					UpgradeChange{
+						UpgradeChange::Level::Safe,
+						function->location(),
+						appendOverride(*function, expectedContracts)
+					}
+				);
+
+			for (auto [begin, end] = inheritedFunctions.equal_range(proxy); begin != end; begin++)
+			{
+				auto& super = (*begin);
+				auto functionType = FunctionType(*function).asCallableFunction(false);
+				auto superType = super.functionType()->asCallableFunction(false);
+
+				if (functionType && functionType->hasEqualParameterTypes(*superType))
+				{
+					/// If function does not specify override and no override with
+					/// contract list was added before.
+					if (!function->overrides() && expectedContracts.size() <= 1)
+						m_changes.push_back(
+							UpgradeChange{
+								UpgradeChange::Level::Safe,
+								function->location(),
+								appendOverride(*function, expectedContracts)
+							}
+						);
+				}
+			}
+		}
+	}
+}
+
+void VirtualFunction::endVisit(ContractDefinition const& _contract)
+{
+	auto const& inheritedFunctions = m_overrideChecker.inheritedFunctions(_contract);
+
+	for (FunctionDefinition const* function: _contract.definedFunctions())
+	{
+		OverrideProxy proxy{function};
+
+		if (!function->isConstructor())
+		{
+			if (
+				!function->markedVirtual() &&
+				!function->isImplemented() &&
+				!function->virtualSemantics() &&
+				function->visibility() > Visibility::Private
+			)
+			{
+				m_changes.push_back(
+					UpgradeChange{
+						UpgradeChange::Level::Safe,
+						function->location(),
+						appendVirtual(*function)
+					}
+				);
+			}
+
+			for (auto [begin, end] = inheritedFunctions.equal_range(proxy); begin != end; begin++)
+			{
+				auto& super = (*begin);
+				if (
+					!function->markedVirtual() &&
+					!super.virtualSemantics()
+				)
+				{
+					m_changes.push_back(
+						UpgradeChange{
+							UpgradeChange::Level::Safe,
+							function->location(),
+							appendVirtual(*function)
+						}
+					);
+				}
+			}
+		}
+	}
+}

tools/solidityUpgrade/Upgrade060.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 <tools/solidityUpgrade/UpgradeChange.h>
+#include <tools/solidityUpgrade/UpgradeSuite.h>
+
+#include <libsolidity/ast/ASTVisitor.h>
+
+namespace solidity::tools
+{
+
+/**
+ * Module that performs analysis on the AST. Finds abstract contracts that are
+ * not marked as such and adds the `abstract` keyword.
+ */
+class AbstractContract: public AnalysisUpgrade
+{
+public:
+	using AnalysisUpgrade::AnalysisUpgrade;
+
+	void analyze(frontend::SourceUnit const& _sourceUnit) { _sourceUnit.accept(*this); }
+private:
+	void endVisit(frontend::ContractDefinition const& _contract);
+};
+
+/**
+ * Module that performs analysis on the AST. Finds functions that need to be
+ * marked `override` and adds the keyword to the function header.
+ */
+class OverridingFunction: public AnalysisUpgrade
+{
+public:
+	using AnalysisUpgrade::AnalysisUpgrade;
+
+	void analyze(frontend::SourceUnit const& _sourceUnit) { _sourceUnit.accept(*this); }
+private:
+	void endVisit(frontend::ContractDefinition const& _contract);
+};
+
+/**
+ * Module that performs analysis on the AST. Finds functions that need to be
+ * marked `virtual` and adds the keyword to the function header.
+ */
+class VirtualFunction: public AnalysisUpgrade
+{
+public:
+	using AnalysisUpgrade::AnalysisUpgrade;
+
+	void analyze(frontend::SourceUnit const& _sourceUnit) { _sourceUnit.accept(*this); }
+private:
+	void endVisit(frontend::ContractDefinition const& _function);
+};
+
+}

tools/solidityUpgrade/UpgradeChange.cpp

@@ -0,0 +1,73 @@
+/*
+	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 <tools/solidityUpgrade/UpgradeChange.h>
+
+#include <liblangutil/SourceReferenceExtractor.h>
+#include <liblangutil/SourceReferenceFormatterHuman.h>
+
+using namespace std;
+using namespace solidity;
+using namespace solidity::langutil;
+using namespace solidity::util;
+using namespace solidity::tools;
+
+void UpgradeChange::apply()
+{
+	m_source.replace(m_location.start, m_location.end - m_location.start, m_patch);
+}
+
+void UpgradeChange::log(bool const _shorten) const
+{
+	stringstream os;
+	SourceReferenceFormatterHuman formatter{os, true};
+
+	string start = to_string(m_location.start);
+	string end = to_string(m_location.end);
+
+	auto color = m_level == Level::Unsafe ? formatting::MAGENTA : formatting::CYAN;
+	auto level = m_level == Level::Unsafe ? "unsafe" : "safe";
+
+	os << endl;
+	AnsiColorized(os, true, {formatting::BOLD, color}) << "Upgrade change (" << level << ")" << endl;
+	os << "=======================" << endl;
+	formatter.printSourceLocation(SourceReferenceExtractor::extract(&m_location));
+	os << endl;
+
+	LineColumn lineEnd = m_location.source->translatePositionToLineColumn(m_location.end);
+	int const leftpad = static_cast<int>(log10(max(lineEnd.line, 1))) + 2;
+
+	stringstream output;
+	output << (_shorten ? shortenSource(m_patch) : m_patch);
+
+	string line;
+	while (getline(output, line))
+	{
+		os << string(leftpad, ' ');
+		AnsiColorized(os, true, {formatting::BOLD, formatting::BLUE}) << "| ";
+		AnsiColorized(os, true, {}) << line << endl;
+	}
+	cout << os.str();
+	cout << endl;
+}
+
+string UpgradeChange::shortenSource(string const& _source)
+{
+	size_t constexpr maxSourceLength = 1000;
+	if (_source.size() > maxSourceLength)
+		return _source.substr(0, min(_source.size(), maxSourceLength)) + "...";
+	return _source;
+}

tools/solidityUpgrade/UpgradeChange.h

@@ -0,0 +1,82 @@
+/*
+	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 <libsolutil/AnsiColorized.h>
+
+#include <liblangutil/SourceLocation.h>
+
+#include <algorithm>
+
+namespace solidity::tools
+{
+
+/**
+ * Models a single source code change, based on the initial source location
+ * and a patch, which needs to be applied.
+ * It implements the concept of level of confidence in the change and distiguishes
+ * safe from unsafe changes. A "safe" change is considered to not break
+ * compilation or change semantics. An "unsafe" change is considered to potentially
+ * change semantics or require further manual management.
+ */
+class UpgradeChange
+{
+public:
+	enum class Level
+	{
+		Safe,
+		Unsafe
+	};
+
+	UpgradeChange(
+		Level _level,
+		langutil::SourceLocation _location,
+		std::string _patch
+	)
+	:
+		m_location(_location),
+		m_source(_location.source->source()),
+		m_patch(_patch),
+		m_level(_level) {}
+
+	~UpgradeChange() {}
+
+	langutil::SourceLocation const& location() { return m_location; }
+	std::string source() const { return m_source; }
+	std::string patch() { return m_patch; }
+	Level level() const { return m_level; }
+
+	/// Does the actual replacement of code under at current source location.
+	/// The change is applied on the upgrade-specific copy of source code.
+	/// The altered code is then requested by the upgrade routine later on.
+	void apply();
+	/// Does a pretty-print of this upgrade change. It uses a source formatter
+	/// provided by the compiler in order to print affected code. Since the patch
+	/// can contain a lot of code lines, it can be shortened, which is signaled
+	/// by setting the flag.
+	void log(bool const _shorten = true) const;
+private:
+	langutil::SourceLocation m_location;
+	std::string m_source;
+	std::string m_patch;
+	Level m_level;
+
+	/// Shortens the given source to a constant limit.
+	static std::string shortenSource(std::string const& _source);
+};
+
+}

tools/solidityUpgrade/UpgradeSuite.h

@@ -0,0 +1,90 @@
+/*
+	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 <tools/solidityUpgrade/UpgradeChange.h>
+
+#include <liblangutil/ErrorReporter.h>
+
+#include <libsolidity/ast/ASTVisitor.h>
+#include <libsolidity/analysis/OverrideChecker.h>
+
+#include <regex>
+
+namespace solidity::tools
+{
+
+/**
+ * The base upgrade module that can be inherited from. Doing so
+ * creates a basic upgrade module that facilitates access to
+ * change reporting.
+ */
+class Upgrade
+{
+public:
+	Upgrade(std::vector<UpgradeChange>& _changes): m_changes(_changes) {}
+
+protected:
+	/// A reference to a suite-specific set of changes.
+	/// It is passed to all upgrade modules and meant to collect
+	/// reported changes.
+	std::vector<UpgradeChange>& m_changes;
+};
+
+/**
+ * A specific upgrade module meant to be run after the analysis phase
+ * of the compiler.
+ */
+class AnalysisUpgrade: public Upgrade, public frontend::ASTConstVisitor
+{
+public:
+	AnalysisUpgrade(std::vector<UpgradeChange>& _changes):
+		Upgrade(_changes),
+		m_errorReporter(m_errors),
+		m_overrideChecker(m_errorReporter)
+	{}
+	/// Interface function for all upgrade modules that are meant
+	/// be run after the analysis phase of the compiler.
+	void analyze(frontend::SourceUnit const&) {}
+protected:
+	langutil::ErrorList m_errors;
+	langutil::ErrorReporter m_errorReporter;
+	frontend::OverrideChecker m_overrideChecker;
+};
+
+/**
+ * The generic upgrade suite. Should be inherited from for each set of
+ * desired upgrade modules.
+ */
+class UpgradeSuite
+{
+public:
+	/// The base interface function that needs to be implemented for each
+	/// suite. It should create suite-specific upgrade modules and trigger
+	/// their analysis.
+	void analyze(frontend::SourceUnit const& _sourceUnit);
+	/// Resets all changes collected so far.
+	void reset() { m_changes.clear(); }
+
+	std::vector<UpgradeChange>& changes() { return m_changes; }
+	std::vector<UpgradeChange> const& changes() const { return m_changes; }
+
+protected:
+	std::vector<UpgradeChange> m_changes;
+};
+
+}

tools/solidityUpgrade/contracts/DocsExamplePass.sol

@@ -0,0 +1,23 @@
+pragma solidity >0.4.23;
+
+contract Updateable {
+    function run() public view returns (bool);
+    function update() public;
+}
+
+contract Upgradable {
+    function run() public view returns (bool);
+    function upgrade();
+}
+
+contract Source is Updateable, Upgradable {
+    function Source() public {}
+
+    function run()
+        public
+        view
+        returns (bool) {}
+
+    function update() {}
+    function upgrade() {}
+}

tools/solidityUpgrade/contracts/Test.sol

@@ -0,0 +1,18 @@
+pragma solidity >0.4.23;
+
+contract Storage {
+    function Storage() public {}
+    function start();
+    function state() public view returns (bool);
+    function stop() public;
+}
+
+contract Observable {
+    function state() public view returns (bool);
+}
+
+contract VolatileStorage is Storage, Observable {
+    function start() {}
+    function state() public view returns (bool) {}
+    function stop() {}
+}

tools/solidityUpgrade/contracts/TestMultiline.sol

@@ -0,0 +1,21 @@
+pragma solidity >0.4.23;
+
+contract Storage {
+    function Storage() {}
+    function init() public;
+    function idle();
+    function destroy() public view;
+}
+
+contract VolatileStorage is Storage {
+    function init()
+        public
+    {}
+
+    function idle() {}
+
+    function destroy()
+        public
+        view
+    {}
+}

tools/solidityUpgrade/contracts/TestNonFixable.sol

@@ -0,0 +1,15 @@
+pragma solidity >0.4.23;
+
+contract Storage {
+    function Storage() {}
+    function init() public;
+    function idle();
+    function destroy() public view;
+}
+
+contract VolatileStorage is Storage {
+    uint[] array;
+    function init() public { array.length = 3; }
+    function idle() {}
+    function destroy() public view {}
+}

tools/solidityUpgrade/main.cpp

@@ -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/>.
+*/
+#include <tools/solidityUpgrade/SourceUpgrade.h>
+
+#include <libsolutil/CommonIO.h>
+#include <libsolutil/AnsiColorized.h>
+
+//#include <test/Common.h>
+
+#include <boost/algorithm/string.hpp>
+#include <boost/algorithm/string/replace.hpp>
+#include <boost/filesystem.hpp>
+#include <boost/program_options.hpp>
+
+#include <cstdlib>
+#include <iostream>
+#include <fstream>
+#include <queue>
+#include <regex>
+
+#if defined(_WIN32)
+#include <windows.h>
+#endif
+
+using namespace solidity;
+using namespace std;
+namespace po = boost::program_options;
+namespace fs = boost::filesystem;
+
+namespace
+{
+
+void setupTerminal()
+{
+#if defined(_WIN32) && defined(ENABLE_VIRTUAL_TERMINAL_PROCESSING)
+	// Set output mode to handle virtual terminal (ANSI escape sequences)
+	// ignore any error, as this is just a "nice-to-have"
+	// only windows needs to be taken care of, as other platforms (Linux/OSX) support them natively.
+	HANDLE hOut = GetStdHandle(STD_OUTPUT_HANDLE);
+	if (hOut == INVALID_HANDLE_VALUE)
+		return;
+
+	DWORD dwMode = 0;
+	if (!GetConsoleMode(hOut, &dwMode))
+		return;
+
+	dwMode |= ENABLE_VIRTUAL_TERMINAL_PROCESSING;
+	if (!SetConsoleMode(hOut, dwMode))
+		return;
+#endif
+}
+
+}
+
+int main(int argc, char** argv)
+{
+	setupTerminal();
+
+	tools::SourceUpgrade upgrade;
+	if (!upgrade.parseArguments(argc, argv))
+		return 1;
+	upgrade.printPrologue();
+	if (!upgrade.processInput())
+		return 1;
+
+	return 0;
+}