decoder_list: add _for_each() macros

src/cmdline.c

@@ -58,8 +58,7 @@ cmdline_quark(void)
 static void
 print_all_decoders(FILE *fp)
 {
-	for (unsigned i = 0; decoder_plugins[i] != NULL; ++i) {
-		const struct decoder_plugin *plugin = decoder_plugins[i];
+	decoder_plugins_for_each(plugin) {
 		const char *const*suffixes;
 
 		fprintf(fp, "[%s]", plugin->name);

src/decoder_list.c

@@ -174,12 +174,9 @@ decoder_plugin_from_mime_type(const char *mimeType, unsigned int next)
 const struct decoder_plugin *
 decoder_plugin_from_name(const char *name)
 {
-	for (unsigned i = 0; decoder_plugins[i] != NULL; ++i) {
-		const struct decoder_plugin *plugin = decoder_plugins[i];
-		if (decoder_plugins_enabled[i] &&
-		    strcmp(plugin->name, name) == 0)
+	decoder_plugins_for_each_enabled(plugin)
+		if (strcmp(plugin->name, name) == 0)
 			return plugin;
-	}
 
 	return NULL;
 }
@@ -227,10 +224,6 @@ void decoder_plugin_init_all(void)
 
 void decoder_plugin_deinit_all(void)
 {
-	for (unsigned i = 0; decoder_plugins[i] != NULL; ++i) {
-		const struct decoder_plugin *plugin = decoder_plugins[i];
-
-		if (decoder_plugins_enabled[i])
-			decoder_plugin_finish(plugin);
-	}
+	decoder_plugins_for_each_enabled(plugin)
+		decoder_plugin_finish(plugin);
 }

src/decoder_list.h

@@ -27,6 +27,16 @@ struct decoder_plugin;
 extern const struct decoder_plugin *const decoder_plugins[];
 extern bool decoder_plugins_enabled[];
 
+#define decoder_plugins_for_each(plugin) \
+	for (const struct decoder_plugin *plugin, \
+		*const*decoder_plugin_iterator = &decoder_plugins[0]; \
+		(plugin = *decoder_plugin_iterator) != NULL; \
+		++decoder_plugin_iterator)
+
+#define decoder_plugins_for_each_enabled(plugin) \
+	decoder_plugins_for_each(plugin) \
+		if (decoder_plugins_enabled[decoder_plugin_iterator - decoder_plugins])
+
 /* interface for using plugins */
 
 /**

src/decoder_print.c

@@ -48,7 +48,6 @@ decoder_plugin_print(struct client *client,
 void
 decoder_list_print(struct client *client)
 {
-	for (unsigned i = 0; decoder_plugins[i] != NULL; ++i)
-		if (decoder_plugins_enabled[i])
-			decoder_plugin_print(client, decoder_plugins[i]);
+	decoder_plugins_for_each_enabled(plugin)
+		decoder_plugin_print(client, plugin);
 }