input/Plugin: migrate init() from class Error to C++ exceptions

src/input/Init.cxx

@@ -21,7 +21,6 @@
 #include "Init.hxx"
 #include "Registry.hxx"
 #include "InputPlugin.hxx"
-#include "util/Error.hxx"
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigOption.hxx"
 #include "config/Block.hxx"
@@ -33,8 +32,8 @@
 
 #include <assert.h>
 
-bool
-input_stream_global_init(Error &error)
+void
+input_stream_global_init()
 {
 	const ConfigBlock empty;
 
@@ -54,12 +53,9 @@ input_stream_global_init(Error &error)
 			/* the plugin is disabled in mpd.conf */
 			continue;
 
-		InputPlugin::InitResult result;
-
 		try {
-			result = plugin->init != nullptr
-				? plugin->init(*block, error)
-				: InputPlugin::InitResult::SUCCESS;
+			if (plugin->init != nullptr)
+				plugin->init(*block);
 		} catch (const PluginUnavailable &e) {
 			FormatError(e,
 				    "Input plugin '%s' is unavailable",
@@ -69,20 +65,7 @@ input_stream_global_init(Error &error)
 			std::throw_with_nested(FormatRuntimeError("Failed to initialize input plugin '%s'",
 								  plugin->name));
 		}
-
-		switch (result) {
-		case InputPlugin::InitResult::SUCCESS:
-			input_plugins_enabled[i] = true;
-			break;
-
-		case InputPlugin::InitResult::ERROR:
-			error.FormatPrefix("Failed to initialize input plugin '%s': ",
-					   plugin->name);
-			return false;
-		}
 	}
-
-	return true;
 }
 
 void input_stream_global_finish(void)

src/input/Init.hxx

@@ -25,8 +25,8 @@ class Error;
 /**
  * Initializes this library and all #InputStream implementations.
  */
-bool
-input_stream_global_init(Error &error);
+void
+input_stream_global_init();
 
 /**
  * Deinitializes this library and all #InputStream implementations.

src/input/InputPlugin.hxx

@@ -40,20 +40,6 @@ class Error;
 struct Tag;
 
 struct InputPlugin {
-	enum class InitResult {
-		/**
-		 * A fatal error has occurred (e.g. misconfiguration).
-		 * The #Error has been set.
-		 */
-		ERROR,
-
-		/**
-		 * The plugin was initialized successfully and is
-		 * ready to be used.
-		 */
-		SUCCESS,
-	};
-
 	const char *name;
 
 	/**
@@ -61,8 +47,10 @@ struct InputPlugin {
 	 *
 	 * Throws #PluginUnavailable if the plugin is not available
 	 * and shall be disabled.
+	 *
+	 * Throws std::runtime_error on (fatal) error.
 	 */
-	InitResult (*init)(const ConfigBlock &block, Error &error);
+	void (*init)(const ConfigBlock &block);
 
 	/**
 	 * Global deinitialization.  Called once before MPD shuts

src/input/plugins/CdioParanoiaInputPlugin.cxx

@@ -27,6 +27,7 @@
 #include "../InputPlugin.hxx"
 #include "util/StringUtil.hxx"
 #include "util/StringCompare.hxx"
+#include "util/RuntimeError.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
 #include "system/ByteOrder.hxx"
@@ -105,8 +106,8 @@ static constexpr Domain cdio_domain("cdio");
 
 static bool default_reverse_endian;
 
-static InputPlugin::InitResult
-input_cdio_init(const ConfigBlock &block, Error &error)
+static void
+input_cdio_init(const ConfigBlock &block)
 {
 	const char *value = block.GetBlockValue("default_byte_order");
 	if (value != nullptr) {
@@ -114,15 +115,10 @@ input_cdio_init(const ConfigBlock &block, Error &error)
 			default_reverse_endian = IsBigEndian();
 		else if (strcmp(value, "big_endian") == 0)
 			default_reverse_endian = IsLittleEndian();
-		else {
-			error.Format(config_domain, 0,
-				     "Unrecognized 'default_byte_order' setting: %s",
-				     value);
-			return InputPlugin::InitResult::ERROR;
-		}
+		else
+			throw FormatRuntimeError("Unrecognized 'default_byte_order' setting: %s",
+						 value);
 	}
-
-	return InputPlugin::InitResult::SUCCESS;
 }
 
 struct cdio_uri {

src/input/plugins/CurlInputPlugin.cxx

@@ -533,8 +533,8 @@ CurlMulti::OnTimeout()
  *
  */
 
-static InputPlugin::InitResult
-input_curl_init(const ConfigBlock &block, gcc_unused Error &error)
+static void
+input_curl_init(const ConfigBlock &block)
 {
 	CURLcode code = curl_global_init(CURL_GLOBAL_ALL);
 	if (code != CURLE_OK)
@@ -577,7 +577,6 @@ input_curl_init(const ConfigBlock &block, gcc_unused Error &error)
 	}
 
 	curl_multi = new CurlMulti(io_thread_get(), multi);
-	return InputPlugin::InitResult::SUCCESS;
 }
 
 static void

src/input/plugins/FfmpegInputPlugin.cxx

@@ -72,17 +72,14 @@ input_ffmpeg_supported(void)
 	return avio_enum_protocols(&opaque, 0) != nullptr;
 }
 
-static InputPlugin::InitResult
-input_ffmpeg_init(gcc_unused const ConfigBlock &block,
-		  gcc_unused Error &error)
+static void
+input_ffmpeg_init(gcc_unused const ConfigBlock &block)
 {
 	FfmpegInit();
 
 	/* disable this plugin if there's no registered protocol */
 	if (!input_ffmpeg_supported())
 		throw PluginUnavailable("No protocol");
-
-	return InputPlugin::InitResult::SUCCESS;
 }
 
 static InputStream *

src/input/plugins/NfsInputPlugin.cxx

@@ -215,11 +215,10 @@ NfsInputStream::OnNfsFileError(Error &&error)
  *
  */
 
-static InputPlugin::InitResult
-input_nfs_init(const ConfigBlock &, Error &)
+static void
+input_nfs_init(const ConfigBlock &)
 {
 	nfs_init();
-	return InputPlugin::InitResult::SUCCESS;
 }
 
 static void

src/input/plugins/SmbclientInputPlugin.cxx

@@ -68,8 +68,8 @@ public:
  *
  */
 
-static InputPlugin::InitResult
-input_smbclient_init(gcc_unused const ConfigBlock &block, gcc_unused Error &error)
+static void
+input_smbclient_init(gcc_unused const ConfigBlock &block)
 {
 	try {
 		SmbclientInit();
@@ -81,8 +81,6 @@ input_smbclient_init(gcc_unused const ConfigBlock &block, gcc_unused Error &erro
 	// TODO: create one global SMBCCTX here?
 
 	// TODO: evaluate ConfigBlock, call smbc_setOption*()
-
-	return InputPlugin::InitResult::SUCCESS;
 }
 
 static InputStream *