config/Global: remove ConfigBlock::SetUsed() call, let caller do that

This fixes an old bug which caused the "unused" warnings to be
unreliable; only the first block in the list was marked as being
"used", no matter if it was really used, and the rest was never marked
as "used", suppressing all warnings for them.

src/config/Global.cxx

@@ -83,10 +83,7 @@ config_get_param(ConfigOption option) noexcept
 const ConfigBlock *
 config_get_block(ConfigBlockOption option) noexcept
 {
-	const auto *block = config_data.blocks[unsigned(option)];
-	if (block != nullptr)
-		block->SetUsed();
-	return block;
+	return config_data.blocks[unsigned(option)];
 }
 
 const ConfigBlock *

src/db/Configured.cxx

@@ -38,10 +38,11 @@ CreateConfiguredDatabase(EventLoop &main_event_loop, EventLoop &io_event_loop,
 		throw FormatRuntimeError("Found both 'database' (line %d) and 'db_file' (line %d) setting",
 					 param->line, path->line);
 
-	if (param != nullptr)
+	if (param != nullptr) {
+		param->SetUsed();
 		return DatabaseGlobalInit(main_event_loop, io_event_loop,
 					  listener, *param);
-	else if (path != nullptr) {
+	} else if (path != nullptr) {
 		ConfigBlock block(path->line);
 		block.AddBlockParam("path", path->value, path->line);
 		return DatabaseGlobalInit(main_event_loop, io_event_loop,

src/decoder/DecoderList.cxx

@@ -143,6 +143,9 @@ void decoder_plugin_init_all(void)
 			/* the plugin is disabled in mpd.conf */
 			continue;
 
+		if (param != nullptr)
+			param->SetUsed();
+
 		if (plugin.Init(*param))
 			decoder_plugins_enabled[i] = true;
 	}

src/filter/LoadChain.cxx

@@ -42,6 +42,8 @@ filter_chain_append_new(PreparedFilter &chain, const char *template_name)
 		throw FormatRuntimeError("Filter template not found: %s",
 					 template_name);
 
+	cfg->SetUsed();
+
 	// Instantiate one of those filter plugins with the template name as a hint
 	auto f = filter_configured_new(*cfg);
 

src/input/Init.cxx

@@ -53,6 +53,8 @@ input_stream_global_init(EventLoop &event_loop)
 			/* the plugin is disabled in mpd.conf */
 			continue;
 
+		block->SetUsed();
+
 		try {
 			if (plugin->init != nullptr)
 				plugin->init(event_loop, *block);

src/neighbor/Glue.cxx

@@ -54,6 +54,8 @@ NeighborGlue::Init(EventLoop &loop, NeighborListener &listener)
 {
 	for (const auto *block = config_get_block(ConfigBlockOption::NEIGHBORS);
 	     block != nullptr; block = block->next) {
+		block->SetUsed();
+
 		try {
 			explorers.emplace_front(CreateNeighborExplorer(loop,
 								       listener,

src/output/MultipleOutputs.cxx

@@ -92,6 +92,7 @@ MultipleOutputs::Configure(EventLoop &event_loop,
 {
 	for (const auto *param = config_get_block(ConfigBlockOption::AUDIO_OUTPUT);
 	     param != nullptr; param = param->next) {
+		param->SetUsed();
 		auto *output = LoadOutputControl(event_loop,
 						 replay_gain_config,
 						 mixer_listener,

src/pcm/ConfiguredResampler.cxx

@@ -125,6 +125,7 @@ GetResamplerConfig(ConfigBlock &buffer)
 		throw FormatRuntimeError("Cannot use both 'resampler' (line %d) and 'samplerate_converter' (line %d)",
 					 block->line, old_param->line);
 
+	block->SetUsed();
 	return block;
 }
 

src/playlist/PlaylistRegistry.cxx

@@ -90,6 +90,9 @@ playlist_list_global_init(void)
 			/* the plugin is disabled in mpd.conf */
 			continue;
 
+		if (param != nullptr)
+			param->SetUsed();
+
 		playlist_plugins_enabled[i] =
 			playlist_plugin_init(playlist_plugins[i], *param);
 	}