fs/Path: add operator/(Path,Path)

Modeled after std::filesystem::operator/() from C++17.

src/CommandLine.cxx

@@ -310,7 +310,7 @@ bool ConfigLoader::TryFile(const AllocatedPath &base_path, Path path)
 {
 	if (base_path.IsNull())
 		return false;
-	auto full_path = AllocatedPath::Build(base_path, path);
+	auto full_path = base_path / path;
 	return TryFile(full_path);
 }
 

src/Main.cxx

@@ -260,7 +260,7 @@ glue_state_file_init()
 		if (cache_dir.IsNull())
 			return;
 
-		path_fs = AllocatedPath::Build(cache_dir, "state");
+		path_fs = cache_dir / Path::FromFS("state");
 #else
 		return;
 #endif
@@ -486,7 +486,7 @@ try {
 	const auto sdcard = Environment::getExternalStorageDirectory();
 	if (!sdcard.IsNull()) {
 		const auto config_path =
-			AllocatedPath::Build(sdcard, "mpd.conf");
+			sdcard / Path::FromFS("mpd.conf");
 		if (FileExists(config_path))
 			ReadConfigFile(config_path);
 	}

src/Mapper.cxx

@@ -82,7 +82,7 @@ map_uri_fs(const char *uri) noexcept
 	if (uri_fs.IsNull())
 		return nullptr;
 
-	return AllocatedPath::Build(music_dir_fs, uri_fs);
+	return music_dir_fs / uri_fs;
 }
 
 std::string
@@ -128,5 +128,5 @@ map_spl_utf8_to_fs(const char *name) noexcept
 	if (filename_fs.IsNull())
 		return nullptr;
 
-	return AllocatedPath::Build(playlist_dir_fs, filename_fs);
+	return playlist_dir_fs / filename_fs;
 }

src/PlaylistFile.cxx

@@ -138,7 +138,7 @@ LoadPlaylistFileInfo(PlaylistInfo &info,
 		return false;
 
 	FileInfo fi;
-	if (!GetFileInfo(AllocatedPath::Build(parent_path_fs, name_fs), fi) ||
+	if (!GetFileInfo(parent_path_fs / name_fs, fi) ||
 	    !fi.IsRegular())
 		return false;
 

src/command/FileCommands.cxx

@@ -81,8 +81,7 @@ handle_listfiles_local(Response &r, Path path_fs)
 		if (name_utf8.empty())
 			continue;
 
-		const AllocatedPath full_fs =
+		const auto full_fs = path_fs / name_fs;
-			AllocatedPath::Build(path_fs, name_fs);
 		FileInfo fi;
 		if (!GetFileInfo(full_fs, fi, false))
 			continue;

src/config/Path.cxx

@@ -113,7 +113,7 @@ ParsePath(const char *path)
 		if (path2.IsNull())
 			return nullptr;
 
-		return AllocatedPath::Build(home, path2);
+		return home / path2;
 	} else if (!PathTraitsUTF8::IsAbsolute(path)) {
 		throw FormatRuntimeError("not an absolute path: %s", path);
 	} else {

src/db/Configured.cxx

@@ -53,8 +53,7 @@ CreateConfiguredDatabase(EventLoop &main_event_loop, EventLoop &io_event_loop,
 		if (cache_dir.IsNull())
 			return nullptr;
 
-		const auto db_file = AllocatedPath::Build(cache_dir,
+		const auto db_file = cache_dir / Path::FromFS(PATH_LITERAL("mpd.db"));
-							  PATH_LITERAL("mpd.db"));
 		const auto db_file_utf8 = db_file.ToUTF8();
 		if (db_file_utf8.empty())
 			return nullptr;

src/db/plugins/simple/SimpleDatabasePlugin.cxx

@@ -428,8 +428,7 @@ SimpleDatabase::Mount(const char *local_uri, const char *storage_uri)
 #ifndef ENABLE_ZLIB
 	constexpr bool compress = false;
 #endif
-	auto db = new SimpleDatabase(AllocatedPath::Build(cache_path,
+	auto db = new SimpleDatabase(cache_path / name_fs,
-							  name_fs.c_str()),
 				     compress);
 	try {
 		db->Open();

src/db/update/InotifyUpdate.cxx

@@ -141,7 +141,7 @@ WatchDirectory::GetUriFS() const noexcept
 	if (uri.IsNull())
 		return name;
 
-	return AllocatedPath::Build(uri, name);
+	return uri / name;
 }
 
 /* we don't look at "." / ".." nor files with newlines in their name */
@@ -181,8 +181,8 @@ recursive_watch_subdirectories(WatchDirectory *directory,
 		if (skip_path(ent->d_name))
 			continue;
 
-		const auto child_path_fs =
+		const auto name_fs = Path::FromFS(ent->d_name);
-			AllocatedPath::Build(path_fs, ent->d_name);
+		const auto child_path_fs = path_fs / name_fs;
 
 		FileInfo fi;
 		try {
@@ -211,7 +211,7 @@ recursive_watch_subdirectories(WatchDirectory *directory,
 			continue;
 
 		directory->children.emplace_front(directory,
-						  AllocatedPath::FromFS(ent->d_name),
+						  name_fs,
 						  ret);
 		child = &directory->children.front();
 
@@ -262,7 +262,7 @@ mpd_inotify_callback(int wd, unsigned mask,
 
 		const auto path_fs = uri_fs.IsNull()
 			? root
-			: AllocatedPath::Build(root, uri_fs.c_str());
+			: (root / uri_fs);
 
 		recursive_watch_subdirectories(directory, path_fs,
 					       directory->GetDepth());

src/fs/CheckFile.cxx

@@ -43,8 +43,7 @@ try {
 
 #ifndef _WIN32
 	try {
-		const auto x = AllocatedPath::Build(path_fs,
+		const auto x = path_fs / Path::FromFS(PathTraitsFS::CURRENT_DIRECTORY);
-						    PathTraitsFS::CURRENT_DIRECTORY);
 		const FileInfo fi2(x);
 	} catch (const std::system_error &e) {
 		if (IsAccessDenied(e))

src/fs/Path.hxx

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2017 The Music Player Daemon Project
+ * Copyright 2003-2018 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -169,4 +169,12 @@ public:
 	const_pointer_type GetSuffix() const noexcept;
 };
 
+/**
+ * Concatenate two path components using the directory separator.
+ *
+ * Wrapper for AllocatedPath::Build().
+ */
+AllocatedPath
+operator/(Path a, Path b) noexcept;
+
 #endif

src/fs/Path2.cxx

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2017 The Music Player Daemon Project
+ * Copyright 2003-2018 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -26,3 +26,9 @@ Path::GetDirectoryName() const noexcept
 {
 	return AllocatedPath::FromFS(PathTraitsFS::GetParent(c_str()));
 }
+
+AllocatedPath
+operator/(Path a, Path b) noexcept
+{
+	return AllocatedPath::Build(a, b);
+}

src/fs/StandardDirectory.cxx

@@ -183,16 +183,16 @@ ParseConfigLine(char *line, const char *dir_name, AllocatedPath &result_dir)
 	*line_end = 0;
 
 	// build the result path
-	const char *path = line;
+	const auto path_fs = Path::FromFS(line);
 
 	AllocatedPath result = nullptr;
 	if (home_relative) {
 		auto home = GetHomeDir();
 		if (home.IsNull())
 			return true;
-		result = AllocatedPath::Build(home, path);
+		result = home / path_fs;
 	} else {
-		result = AllocatedPath::FromFS(path);
+		result = AllocatedPath(path_fs);
 	}
 
 	if (IsValidDir(result.c_str())) {
@@ -209,9 +209,8 @@ try {
 	auto config_dir = GetUserConfigDir();
 	if (config_dir.IsNull())
 		return result;
-	auto dirs_file = AllocatedPath::Build(config_dir, "user-dirs.dirs");
 
-	TextFile input(dirs_file);
+	TextFile input(config_dir / Path::FromFS("user-dirs.dirs"));
 	char *line;
 	while ((line = input.ReadLine()) != nullptr)
 		if (ParseConfigLine(line, name, result))
@@ -237,7 +236,7 @@ GetUserConfigDir() noexcept
 	// Check for $HOME/.config
 	auto home = GetHomeDir();
 	if (!home.IsNull()) {
-		AllocatedPath fallback = AllocatedPath::Build(home, ".config");
+		auto fallback = home / Path::FromFS(".config");
 		if (IsValidDir(fallback.c_str()))
 			return fallback;
 	}
@@ -274,7 +273,7 @@ GetUserCacheDir() noexcept
 	// Check for $HOME/.cache
 	auto home = GetHomeDir();
 	if (!home.IsNull()) {
-		AllocatedPath fallback = AllocatedPath::Build(home, ".cache");
+		auto fallback = home / Path::FromFS(".cache");
 		if (IsValidDir(fallback.c_str()))
 			return fallback;
 	}

src/storage/plugins/LocalStorage.cxx

@@ -114,8 +114,7 @@ LocalStorage::MapFSOrThrow(const char *uri_utf8) const
 	if (StringIsEmpty(uri_utf8))
 		return base_fs;
 
-	return AllocatedPath::Build(base_fs,
+	return base_fs / AllocatedPath::FromUTF8Throw(uri_utf8);
-				    AllocatedPath::FromUTF8Throw(uri_utf8));
 }
 
 AllocatedPath
@@ -176,7 +175,7 @@ LocalDirectoryReader::Read() noexcept
 StorageFileInfo
 LocalDirectoryReader::GetInfo(bool follow)
 {
-	return Stat(AllocatedPath::Build(base_fs, reader.GetEntry()), follow);
+	return Stat(base_fs / reader.GetEntry(), follow);
 }
 
 std::unique_ptr<Storage>