neighbor/Plugin: migrate from class Error to C++ exceptions

src/Main.cxx

@@ -461,10 +461,7 @@ int mpd_main(int argc, char *argv[])
 
 #ifdef ENABLE_NEIGHBOR_PLUGINS
 	instance->neighbors = new NeighborGlue();
-	if (!instance->neighbors->Init(io_thread_get(), *instance, error)) {
-		LogError(error);
-		return EXIT_FAILURE;
-	}
+	instance->neighbors->Init(io_thread_get(), *instance);
 
 	if (instance->neighbors->IsEmpty()) {
 		delete instance->neighbors;
@@ -563,9 +560,8 @@ try {
 	io_thread_start();
 
 #ifdef ENABLE_NEIGHBOR_PLUGINS
-	if (instance->neighbors != nullptr &&
-	    !instance->neighbors->Open(error))
-		FatalError(error);
+	if (instance->neighbors != nullptr)
+		instance->neighbors->Open();
 #endif
 
 	ZeroconfInit(instance->event_loop);

src/neighbor/Explorer.hxx

@@ -22,7 +22,6 @@
 
 #include <forward_list>
 
-class Error;
 class NeighborListener;
 struct NeighborInfo;
 
@@ -54,8 +53,10 @@ public:
 
 	/**
          * Start exploring the neighborhood.
+	 *
+	 * Throws std::runtime_error on error.
 	 */
-	virtual bool Open(Error &error) = 0;
+	virtual void Open() = 0;
 
 	/**
          * Stop exploring.

src/neighbor/Glue.cxx

@@ -26,7 +26,6 @@
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigError.hxx"
 #include "config/Block.hxx"
-#include "util/Error.hxx"
 #include "util/RuntimeError.hxx"
 
 #include <stdexcept>
@@ -40,63 +39,50 @@ NeighborGlue::~NeighborGlue() {}
 
 static NeighborExplorer *
 CreateNeighborExplorer(EventLoop &loop, NeighborListener &listener,
-		       const ConfigBlock &block, Error &error)
+		       const ConfigBlock &block)
 {
 	const char *plugin_name = block.GetBlockValue("plugin");
-	if (plugin_name == nullptr) {
-		error.Set(config_domain,
-			  "Missing \"plugin\" configuration");
-		return nullptr;
-	}
+	if (plugin_name == nullptr)
+		throw std::runtime_error("Missing \"plugin\" configuration");
 
 	const NeighborPlugin *plugin = GetNeighborPluginByName(plugin_name);
-	if (plugin == nullptr) {
-		error.Format(config_domain, "No such neighbor plugin: %s",
-			     plugin_name);
-		return nullptr;
-	}
+	if (plugin == nullptr)
+		throw FormatRuntimeError("No such neighbor plugin: %s",
+					 plugin_name);
 
-	return plugin->create(loop, listener, block, error);
+	return plugin->create(loop, listener, block);
 }
 
-bool
-NeighborGlue::Init(EventLoop &loop, NeighborListener &listener, Error &error)
+void
+NeighborGlue::Init(EventLoop &loop, NeighborListener &listener)
 {
 	for (const auto *block = config_get_block(ConfigBlockOption::NEIGHBORS);
 	     block != nullptr; block = block->next) {
 		try {
 			auto *explorer =
-				CreateNeighborExplorer(loop, listener, *block,
-						       error);
-			if (explorer == nullptr) {
-				error.FormatPrefix("Line %i: ", block->line);
-				return false;
-			}
-
+				CreateNeighborExplorer(loop, listener, *block);
 			explorers.emplace_front(explorer);
 		} catch (...) {
 			std::throw_with_nested(FormatRuntimeError("Line %i: ",
 								  block->line));
 		}
 	}
-
-	return true;
 }
 
-bool
-NeighborGlue::Open(Error &error)
+void
+NeighborGlue::Open()
 {
 	for (auto i = explorers.begin(), end = explorers.end();
 	     i != end; ++i) {
-		if (!i->explorer->Open(error)) {
+		try {
+			i->explorer->Open();
+		} catch (...) {
 			/* roll back */
 			for (auto k = explorers.begin(); k != i; ++k)
 				k->explorer->Close();
-			return false;
+			throw;
 		}
 	}
-
-	return true;
 }
 
 void

src/neighbor/Glue.hxx

@@ -27,7 +27,6 @@
 #include <forward_list>
 
 struct config_param;
-class Error;
 class EventLoop;
 class NeighborExplorer;
 class NeighborListener;
@@ -60,9 +59,12 @@ public:
 		return explorers.empty();
 	}
 
-	bool Init(EventLoop &loop, NeighborListener &listener, Error &error);
+	/**
+	 * Throws std::runtime_error on error.
+	 */
+	void Init(EventLoop &loop, NeighborListener &listener);
 
-	bool Open(Error &error);
+	void Open();
 	void Close();
 
 	/**

src/neighbor/NeighborPlugin.hxx

@@ -21,7 +21,6 @@
 #define MPD_NEIGHBOR_PLUGIN_HXX
 
 struct ConfigBlock;
-class Error;
 class EventLoop;
 class NeighborListener;
 class NeighborExplorer;
@@ -33,8 +32,7 @@ struct NeighborPlugin {
 	 * Allocates and configures a #NeighborExplorer instance.
 	 */
 	NeighborExplorer *(*create)(EventLoop &loop, NeighborListener &listener,
-				    const ConfigBlock &block,
-				    Error &error);
+				    const ConfigBlock &block);
 };
 
 #endif

src/neighbor/plugins/SmbclientNeighborPlugin.cxx

@@ -72,7 +72,7 @@ public:
 		:NeighborExplorer(_listener) {}
 
 	/* virtual methods from class NeighborExplorer */
-	virtual bool Open(Error &error) override;
+	void Open() override;
 	virtual void Close() override;
 	virtual List GetList() const override;
 
@@ -82,12 +82,11 @@ private:
 	static void ThreadFunc(void *ctx);
 };
 
-bool
-SmbclientNeighborExplorer::Open(gcc_unused Error &error)
+void
+SmbclientNeighborExplorer::Open()
 {
 	quit = false;
 	thread.Start(ThreadFunc, this);
-	return true;
 }
 
 void
@@ -270,8 +269,7 @@ SmbclientNeighborExplorer::ThreadFunc(void *ctx)
 static NeighborExplorer *
 smbclient_neighbor_create(gcc_unused EventLoop &loop,
 			  NeighborListener &listener,
-			  gcc_unused const ConfigBlock &block,
-			  gcc_unused Error &error)
+			  gcc_unused const ConfigBlock &block)
 {
 	SmbclientInit();
 

src/neighbor/plugins/UpnpNeighborPlugin.cxx

@@ -60,7 +60,7 @@ public:
 		:NeighborExplorer(_listener) {}
 
 	/* virtual methods from class NeighborExplorer */
-	virtual bool Open(Error &error) override;
+	void Open() override;
 	virtual void Close() override;
 	virtual List GetList() const override;
 
@@ -70,8 +70,8 @@ private:
 	virtual void LostUPnP(const ContentDirectoryService &service) override;
 };
 
-bool
-UpnpNeighborExplorer::Open(gcc_unused Error &error)
+void
+UpnpNeighborExplorer::Open()
 {
 	UpnpClient_Handle handle;
 	UpnpClientGlobalInit(handle);
@@ -85,8 +85,6 @@ UpnpNeighborExplorer::Open(gcc_unused Error &error)
 		UpnpClientGlobalFinish();
 		throw;
 	}
-
-	return true;
 }
 
 void
@@ -130,8 +128,7 @@ UpnpNeighborExplorer::LostUPnP(const ContentDirectoryService &service)
 static NeighborExplorer *
 upnp_neighbor_create(gcc_unused EventLoop &loop,
 		     NeighborListener &listener,
-		     gcc_unused const ConfigBlock &block,
-		     gcc_unused Error &error)
+		     gcc_unused const ConfigBlock &block)
 {
 	return new UpnpNeighborExplorer(listener);
 }

test/run_neighbor_explorer.cxx

@@ -24,7 +24,6 @@
 #include "neighbor/Glue.hxx"
 #include "fs/Path.hxx"
 #include "event/Loop.hxx"
-#include "util/Error.hxx"
 #include "Log.hxx"
 
 #include <stdio.h>
@@ -56,8 +55,6 @@ try {
 
 	/* read configuration file (mpd.conf) */
 
-	Error error;
-
 	config_global_init();
 	ReadConfigFile(config_path);
 
@@ -69,17 +66,15 @@ try {
 
 	MyNeighborListener listener;
 	NeighborGlue neighbor;
-	if (!neighbor.Init(loop, listener, error) || !neighbor.Open(error)) {
-		LogError(error);
-		return EXIT_FAILURE;
-	}
+	neighbor.Init(loop, listener);
+	neighbor.Open();
 
 	/* run */
 
 	loop.Run();
 	neighbor.Close();
 	return EXIT_SUCCESS;
- } catch (const std::exception &e) {
+} catch (const std::exception &e) {
 	LogError(e);
 	return EXIT_FAILURE;
- }
+}