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

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

src/command/CommandError.cxx

@@ -54,7 +54,7 @@
 
 gcc_const
 static enum ack
-ToAck(PlaylistResult result)
+ToAck(PlaylistResult result) noexcept
 {
 	switch (result) {
 	case PlaylistResult::SUCCESS:
@@ -90,7 +90,7 @@ ToAck(PlaylistResult result)
 #ifdef ENABLE_DATABASE
 gcc_const
 static enum ack
-ToAck(DatabaseErrorCode code)
+ToAck(DatabaseErrorCode code) noexcept
 {
 	switch (code) {
 	case DatabaseErrorCode::DISABLED:
@@ -107,7 +107,7 @@ ToAck(DatabaseErrorCode code)
 
 gcc_pure
 static enum ack
-ToAck(std::exception_ptr ep)
+ToAck(std::exception_ptr ep) noexcept
 {
 	try {
 		std::rethrow_exception(ep);

src/command/FileCommands.cxx

@@ -44,7 +44,7 @@
 
 gcc_pure
 static bool
-SkipNameFS(PathTraitsFS::const_pointer_type name_fs)
+SkipNameFS(PathTraitsFS::const_pointer_type name_fs) noexcept
 {
 	return name_fs[0] == '.' &&
 		(name_fs[1] == 0 ||
@@ -53,7 +53,7 @@ SkipNameFS(PathTraitsFS::const_pointer_type name_fs)
 
 gcc_pure
 static bool
-skip_path(Path name_fs)
+skip_path(Path name_fs) noexcept
 {
 	return name_fs.HasNewline();
 }
@@ -107,7 +107,7 @@ handle_listfiles_local(Response &r, Path path_fs)
 
 gcc_pure
 static bool
-IsValidName(const char *p)
+IsValidName(const char *p) noexcept
 {
 	if (!IsAlphaASCII(*p))
 		return false;
@@ -123,7 +123,7 @@ IsValidName(const char *p)
 
 gcc_pure
 static bool
-IsValidValue(const char *p)
+IsValidValue(const char *p) noexcept
 {
 	while (*p) {
 		const char ch = *p++;

src/command/NeighborCommands.cxx

@@ -30,7 +30,7 @@
 #include <string>
 
 bool
-neighbor_commands_available(const Instance &instance)
+neighbor_commands_available(const Instance &instance) noexcept
 {
 	return instance.neighbors != nullptr;
 }

src/command/NeighborCommands.hxx

@@ -30,7 +30,7 @@ class Response;
 
 gcc_pure
 bool
-neighbor_commands_available(const Instance &instance);
+neighbor_commands_available(const Instance &instance) noexcept;
 
 CommandResult
 handle_listneighbors(Client &client, Request request, Response &response);

src/command/PlaylistCommands.cxx

@@ -39,7 +39,7 @@
 #include "util/ConstBuffer.hxx"
 
 bool
-playlist_commands_available()
+playlist_commands_available() noexcept
 {
 	return !map_spl_path().IsNull();
 }

src/command/PlaylistCommands.hxx

@@ -29,7 +29,7 @@ class Response;
 
 gcc_const
 bool
-playlist_commands_available();
+playlist_commands_available() noexcept;
 
 CommandResult
 handle_save(Client &client, Request request, Response &response);

src/command/StorageCommands.cxx

@@ -45,7 +45,7 @@
 
 gcc_pure
 static bool
-skip_path(const char *name_utf8)
+skip_path(const char *name_utf8) noexcept
 {
 	return strchr(name_utf8, '\n') != nullptr;
 }