From c8bb3c0b717bc0cd4fdfb40093963ce01a2d269b Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Wed, 2 Nov 2016 10:30:46 +0100
Subject: [PATCH] CommandLine: migrate from class Error to C++ exceptions

---
 src/CommandLine.cxx | 35 ++++++++++++++---------------------
 src/CommandLine.hxx |  7 ++-----
 src/Main.cxx        | 10 +---------
 3 files changed, 17 insertions(+), 35 deletions(-)

diff --git a/src/CommandLine.cxx b/src/CommandLine.cxx
index 696a79474..1171828a1 100644
--- a/src/CommandLine.cxx
+++ b/src/CommandLine.cxx
@@ -35,8 +35,9 @@
 #include "fs/Traits.hxx"
 #include "fs/FileSystem.hxx"
 #include "fs/StandardDirectory.hxx"
+#include "system/Error.hxx"
 #include "util/Macros.hxx"
-#include "util/Error.hxx"
+#include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
 #include "util/OptionDef.hxx"
 #include "util/OptionParser.hxx"
@@ -301,9 +302,8 @@ bool ConfigLoader::TryFile(const AllocatedPath &base_path,
 	return TryFile(full_path);
 }
 
-bool
-parse_cmdline(int argc, char **argv, struct options *options,
-	      Error &error)
+void
+ParseCommandLine(int argc, char **argv, struct options *options)
 {
 	bool use_config_file = true;
 	options->kill = false;
@@ -341,9 +341,8 @@ parse_cmdline(int argc, char **argv, struct options *options,
 		if (parser.CheckOption(opt_help, opt_help_alt))
 			help();
 
-		error.Format(cmdline_domain, "invalid option: %s",
-			     parser.GetOption());
-		return false;
+		throw FormatRuntimeError("invalid option: %s",
+					 parser.GetOption());
 	}
 
 	/* initialize the logging library, so the configuration file
@@ -353,7 +352,7 @@ parse_cmdline(int argc, char **argv, struct options *options,
 	if (!use_config_file) {
 		LogDebug(cmdline_domain,
 			 "Ignoring config, using daemon defaults");
-		return true;
+		return;
 	}
 
 	// Second pass: find non-option parameters (i.e. config file)
@@ -365,8 +364,8 @@ parse_cmdline(int argc, char **argv, struct options *options,
 			config_file = argv[i];
 			continue;
 		}
-		error.Set(cmdline_domain, "too many arguments");
-		return false;
+
+		throw std::runtime_error("too many arguments");
 	}
 
 	if (config_file != nullptr) {
@@ -375,16 +374,14 @@ parse_cmdline(int argc, char **argv, struct options *options,
 		wchar_t buffer[MAX_PATH];
 		auto result = MultiByteToWideChar(CP_ACP, 0, config_file, -1,
 						  buffer, ARRAY_SIZE(buffer));
-		if (result <= 0) {
-			error.SetLastError("MultiByteToWideChar() failed");
-			return false;
-		}
+		if (result <= 0)
+			throw MakeLastError("MultiByteToWideChar() failed");
 
 		ReadConfigFile(Path::FromFS(buffer));
 #else
 		ReadConfigFile(Path::FromFS(config_file));
 #endif
-		return true;
+		return;
 	}
 
 	/* use default configuration file path */
@@ -403,10 +400,6 @@ parse_cmdline(int argc, char **argv, struct options *options,
 		loader.TryFile(GetHomeDir(), USER_CONFIG_FILE_LOCATION2) ||
 		loader.TryFile(Path::FromFS(SYSTEM_CONFIG_FILE_LOCATION));
 #endif
-	if (!found) {
-		error.Set(cmdline_domain, "No configuration file found");
-		return false;
-	}
-
-	return true;
+	if (!found)
+		throw std::runtime_error("No configuration file found");
 }
diff --git a/src/CommandLine.hxx b/src/CommandLine.hxx
index 344e94362..2a3f8c248 100644
--- a/src/CommandLine.hxx
+++ b/src/CommandLine.hxx
@@ -20,8 +20,6 @@
 #ifndef MPD_COMMAND_LINE_HXX
 #define MPD_COMMAND_LINE_HXX
 
-class Error;
-
 struct options {
 	bool kill;
 	bool daemon;
@@ -29,8 +27,7 @@ struct options {
 	bool verbose;
 };
 
-bool
-parse_cmdline(int argc, char **argv, struct options *options,
-	      Error &error);
+void
+ParseCommandLine(int argc, char **argv, struct options *options);
 
 #endif
diff --git a/src/Main.cxx b/src/Main.cxx
index 00b9515f0..8689eb178 100644
--- a/src/Main.cxx
+++ b/src/Main.cxx
@@ -49,7 +49,6 @@
 #include "pcm/PcmConvert.hxx"
 #include "unix/SignalHandlers.hxx"
 #include "system/FatalError.hxx"
-#include "util/Error.hxx"
 #include "thread/Slack.hxx"
 #include "lib/icu/Init.hxx"
 #include "config/ConfigGlobal.hxx"
@@ -170,7 +169,6 @@ InitStorage()
 static bool
 glue_db_init_and_load(void)
 {
-	Error error;
 	instance->database =
 		CreateConfiguredDatabase(instance->event_loop, *instance);
 	if (instance->database == nullptr)
@@ -367,7 +365,6 @@ static inline
 int mpd_main(int argc, char *argv[])
 try {
 	struct options options;
-	Error error;
 
 #ifdef ENABLE_DAEMON
 	daemonize_close_stdin();
@@ -399,10 +396,7 @@ try {
 			ReadConfigFile(config_path);
 	}
 #else
-	if (!parse_cmdline(argc, argv, &options, error)) {
-		LogError(error);
-		return EXIT_FAILURE;
-	}
+	ParseCommandLine(argc, argv, &options);
 #endif
 
 #ifdef ENABLE_DAEMON
@@ -461,8 +455,6 @@ try {
 
 static int mpd_main_after_fork(struct options options)
 try {
-	Error error;
-
 	ConfigureFS();
 
 	glue_mapper_init();