*: add "noexcept" to many, many function prototypes

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

src/db/plugins/simple/Directory.cxx

@@ -65,7 +65,7 @@ Directory::Delete()
 }
 
 const char *
-Directory::GetName() const
+Directory::GetName() const noexcept
 {
 	assert(!IsRoot());
 
@@ -89,7 +89,7 @@ Directory::CreateChild(const char *name_utf8)
 }
 
 const Directory *
-Directory::FindChild(const char *name) const
+Directory::FindChild(const char *name) const noexcept
 {
 	assert(holding_db_lock());
 
@@ -101,7 +101,7 @@ Directory::FindChild(const char *name) const
 }
 
 void
-Directory::PruneEmpty()
+Directory::PruneEmpty() noexcept
 {
 	assert(holding_db_lock());
 
@@ -118,7 +118,7 @@ Directory::PruneEmpty()
 }
 
 Directory::LookupResult
-Directory::LookupDirectory(const char *uri)
+Directory::LookupDirectory(const char *uri) noexcept
 {
 	assert(holding_db_lock());
 	assert(uri != nullptr);
@@ -173,7 +173,7 @@ Directory::AddSong(Song *song)
 }
 
 void
-Directory::RemoveSong(Song *song)
+Directory::RemoveSong(Song *song) noexcept
 {
 	assert(holding_db_lock());
 	assert(song != nullptr);
@@ -183,7 +183,7 @@ Directory::RemoveSong(Song *song)
 }
 
 const Song *
-Directory::FindSong(const char *name_utf8) const
+Directory::FindSong(const char *name_utf8) const noexcept
 {
 	assert(holding_db_lock());
 	assert(name_utf8 != nullptr);
@@ -200,13 +200,13 @@ Directory::FindSong(const char *name_utf8) const
 
 gcc_pure
 static bool
-directory_cmp(const Directory &a, const Directory &b)
+directory_cmp(const Directory &a, const Directory &b) noexcept
 {
 	return IcuCollate(a.path.c_str(), b.path.c_str()) < 0;
 }
 
 void
-Directory::Sort()
+Directory::Sort() noexcept
 {
 	assert(holding_db_lock());
 
@@ -261,7 +261,7 @@ Directory::Walk(bool recursive, const SongFilter *filter,
 }
 
 LightDirectory
-Directory::Export() const
+Directory::Export() const noexcept
 {
 	return LightDirectory(GetPath(), mtime);
 }

src/db/plugins/simple/Directory.hxx

@@ -134,10 +134,10 @@ public:
 	 * Caller must lock the #db_mutex.
 	 */
 	gcc_pure
-	const Directory *FindChild(const char *name) const;
+	const Directory *FindChild(const char *name) const noexcept;
 
 	gcc_pure
-	Directory *FindChild(const char *name) {
+	Directory *FindChild(const char *name) noexcept {
 		const Directory *cthis = this;
 		return const_cast<Directory *>(cthis->FindChild(name));
 	}
@@ -177,10 +177,10 @@ public:
 	 * @return the Directory, or nullptr if none was found
 	 */
 	gcc_pure
-	LookupResult LookupDirectory(const char *uri);
+	LookupResult LookupDirectory(const char *uri) noexcept;
 
 	gcc_pure
-	bool IsEmpty() const {
+	bool IsEmpty() const noexcept {
 		return children.empty() &&
 			songs.empty() &&
 			playlists.empty();
@@ -195,13 +195,13 @@ public:
 	 * Returns the base name of the directory.
 	 */
 	gcc_pure
-	const char *GetName() const;
+	const char *GetName() const noexcept;
 
 	/**
 	 * Is this the root directory of the music database?
 	 */
 	gcc_pure
-	bool IsRoot() const {
+	bool IsRoot() const noexcept {
 		return parent == nullptr;
 	}
 
@@ -229,10 +229,10 @@ public:
 	 * Caller must lock the #db_mutex.
 	 */
 	gcc_pure
-	const Song *FindSong(const char *name_utf8) const;
+	const Song *FindSong(const char *name_utf8) const noexcept;
 
 	gcc_pure
-	Song *FindSong(const char *name_utf8) {
+	Song *FindSong(const char *name_utf8) noexcept {
 		const Directory *cthis = this;
 		return const_cast<Song *>(cthis->FindSong(name_utf8));
 	}
@@ -248,19 +248,19 @@ public:
 	 * invalidates the song object, because the "parent" attribute becomes
 	 * stale), but does not free it.
 	 */
-	void RemoveSong(Song *song);
+	void RemoveSong(Song *song) noexcept;
 
 	/**
 	 * Caller must lock the #db_mutex.
 	 */
-	void PruneEmpty();
+	void PruneEmpty() noexcept;
 
 	/**
 	 * Sort all directory entries recursively.
 	 *
 	 * Caller must lock the #db_mutex.
 	 */
-	void Sort();
+	void Sort() noexcept;
 
 	/**
 	 * Caller must lock #db_mutex.
@@ -270,7 +270,7 @@ public:
 		  VisitPlaylist visit_playlist) const;
 
 	gcc_pure
-	LightDirectory Export() const;
+	LightDirectory Export() const noexcept;
 };
 
 #endif

src/db/plugins/simple/DirectorySave.cxx

@@ -40,7 +40,7 @@
 
 gcc_const
 static const char *
-DeviceToTypeString(unsigned device)
+DeviceToTypeString(unsigned device) noexcept
 {
 	switch (device) {
 	case DEVICE_INARCHIVE:
@@ -56,7 +56,7 @@ DeviceToTypeString(unsigned device)
 
 gcc_pure
 static unsigned
-ParseTypeString(const char *type)
+ParseTypeString(const char *type) noexcept
 {
 	if (strcmp(type, "archive") == 0)
 		return DEVICE_INARCHIVE;

src/db/plugins/simple/Song.cxx

@@ -77,7 +77,7 @@ Song::Free()
 }
 
 std::string
-Song::GetURI() const
+Song::GetURI() const noexcept
 {
 	assert(*uri);
 
@@ -96,7 +96,7 @@ Song::GetURI() const
 }
 
 LightSong
-Song::Export() const
+Song::Export() const noexcept
 {
 	LightSong dest;
 	dest.directory = parent->IsRoot()

src/db/plugins/simple/Song.hxx

@@ -123,10 +123,10 @@ struct Song {
 	 * location within the music directory.
 	 */
 	gcc_pure
-	std::string GetURI() const;
+	std::string GetURI() const noexcept;
 
 	gcc_pure
-	LightSong Export() const;
+	LightSong Export() const noexcept;
 };
 
 typedef boost::intrusive::list<Song,

src/db/plugins/simple/SongSort.cxx

@@ -26,7 +26,7 @@
 #include <stdlib.h>
 
 static int
-compare_utf8_string(const char *a, const char *b)
+compare_utf8_string(const char *a, const char *b) noexcept
 {
 	if (a == nullptr)
 		return b == nullptr ? 0 : -1;
@@ -42,8 +42,7 @@ compare_utf8_string(const char *a, const char *b)
  * nullptr.
  */
 static int
-compare_string_tag_item(const Tag &a, const Tag &b,
-			TagType type)
+compare_string_tag_item(const Tag &a, const Tag &b, TagType type) noexcept
 {
 	return compare_utf8_string(a.GetValue(type),
 				   b.GetValue(type));
@@ -54,7 +53,7 @@ compare_string_tag_item(const Tag &a, const Tag &b,
  * (e.g. disc or track number).  Either one may be nullptr.
  */
 static int
-compare_number_string(const char *a, const char *b)
+compare_number_string(const char *a, const char *b) noexcept
 {
 	long ai = a == nullptr ? 0 : strtol(a, nullptr, 10);
 	long bi = b == nullptr ? 0 : strtol(b, nullptr, 10);
@@ -69,7 +68,7 @@ compare_number_string(const char *a, const char *b)
 }
 
 static int
-compare_tag_item(const Tag &a, const Tag &b, TagType type)
+compare_tag_item(const Tag &a, const Tag &b, TagType type) noexcept
 {
 	return compare_number_string(a.GetValue(type),
 				     b.GetValue(type));
@@ -78,7 +77,7 @@ compare_tag_item(const Tag &a, const Tag &b, TagType type)
 /* Only used for sorting/searchin a songvec, not general purpose compares */
 gcc_pure
 static bool
-song_cmp(const Song &a, const Song &b)
+song_cmp(const Song &a, const Song &b) noexcept
 {
 	int ret;
 
@@ -102,7 +101,7 @@ song_cmp(const Song &a, const Song &b)
 }
 
 void
-song_list_sort(SongList &songs)
+song_list_sort(SongList &songs) noexcept
 {
 	songs.sort(song_cmp);
 }

src/db/plugins/simple/SongSort.hxx

@@ -23,6 +23,6 @@
 #include "Song.hxx"
 
 void
-song_list_sort(SongList &songs);
+song_list_sort(SongList &songs) noexcept;
 
 #endif