createSymlinkIfSupportedByFilesystem(): Add support for directory symlinks used on Windows

Author: cameel

test/FilesystemUtils.cpp

@@ -39,7 +39,7 @@ void solidity::test::createFilesWithParentDirs(set<boost::filesystem::path> cons
 	}
 }
 
-void solidity::test::createFileWithContent(boost::filesystem::path const& _path, string const& content)
+void solidity::test::createFileWithContent(boost::filesystem::path const& _path, string const& _content)
 {
 	if (boost::filesystem::is_regular_file(_path))
 		BOOST_THROW_EXCEPTION(runtime_error("File already exists: \"" + _path.string() + "\".")); \
@@ -49,16 +49,21 @@ void solidity::test::createFileWithContent(boost::filesystem::path const& _path,
 	if (newFile.fail() || !boost::filesystem::is_regular_file(_path))
 		BOOST_THROW_EXCEPTION(runtime_error("Failed to create a file: \"" + _path.string() + "\".")); \
 
-	newFile << content;
+	newFile << _content;
 }
 
 bool solidity::test::createSymlinkIfSupportedByFilesystem(
 	boost::filesystem::path const& _targetPath,
-	boost::filesystem::path const& _linkName
+	boost::filesystem::path const& _linkName,
+	bool _directorySymlink
 )
 {
 	boost::system::error_code symlinkCreationError;
-	boost::filesystem::create_symlink(_targetPath, _linkName, symlinkCreationError);
+
+	if (_directorySymlink)
+		boost::filesystem::create_directory_symlink(_targetPath, _linkName, symlinkCreationError);
+	else
+		boost::filesystem::create_symlink(_targetPath, _linkName, symlinkCreationError);
 
 	if (!symlinkCreationError)
 		return true;

test/FilesystemUtils.h

@@ -35,16 +35,20 @@ void createFilesWithParentDirs(std::set<boost::filesystem::path> const& _paths,
 
 /// Creates a file with the exact content specified in the second argument.
 /// Throws an exception if the file already exists or if the parent directory of the file does not.
-void createFileWithContent(boost::filesystem::path const& _path, std::string const& content);
+void createFileWithContent(boost::filesystem::path const& _path, std::string const& _content);
 
 /// Creates a symlink between two paths.
 /// The target does not have to exist.
+/// If @p directorySymlink is true, indicate to the operating system that this is a directory
+/// symlink. On some systems (e.g. Windows) it's possible to create a non-directory symlink pointing
+/// at a directory, which makes such a symlinks unusable.
 /// @returns true if the symlink has been successfully created, false if the filesystem does not
 /// support symlinks.
 /// Throws an exception of the operation fails for a different reason.
 bool createSymlinkIfSupportedByFilesystem(
 	boost::filesystem::path const& _targetPath,
-	boost::filesystem::path const& _linkName
+	boost::filesystem::path const& _linkName,
+	bool _directorySymlink
 );
 
 }

test/libsolutil/CommonIO.cpp

@@ -58,7 +58,7 @@ BOOST_AUTO_TEST_CASE(readFileAsString_symlink)
 	TemporaryDirectory tempDir("common-io-test-");
 	createFileWithContent(tempDir.path() / "test.txt", "ABC\ndef\n");
 
-	if (!createSymlinkIfSupportedByFilesystem("test.txt", tempDir.path() / "symlink.txt"))
+	if (!createSymlinkIfSupportedByFilesystem("test.txt", tempDir.path() / "symlink.txt", false))
 		return;
 
 	BOOST_TEST(readFileAsString(tempDir.path() / "symlink.txt") == "ABC\ndef\n");