Use maybe_unused attribute

Author: qarkai

src/color-man-heif.cc

@@ -120,7 +120,7 @@ guchar *nclx_to_lcms_profile(const heif_color_profile_nclx *nclx, guint &profile
 {
 	if (!nclx || nclx->color_primaries == heif_color_primaries_unspecified) return nullptr;
 
-	const gchar *primaries_name = "";
+	[[maybe_unused]] const gchar *primaries_name = "";
 	switch (nclx->color_primaries)
 		{
 		case heif_color_primaries_ITU_R_BT_709_5:
@@ -161,7 +161,6 @@ guchar *nclx_to_lcms_profile(const heif_color_profile_nclx *nclx, guint &profile
 			return nullptr;
 		}
 
-	(void)primaries_name; // @todo Use [[maybe_unused]] since C++17
 	DEBUG_1("nclx primaries: %s: ", primaries_name);
 
 	using GetCurve = std::function<cmsToneCurve *()>;
@@ -192,7 +191,7 @@ guchar *nclx_to_lcms_profile(const heif_color_profile_nclx *nclx, guint &profile
 	};
 
 	g_auto(cmsHPROFILE) profile = nullptr;
-	const gchar *trc_name = "";
+	[[maybe_unused]] const gchar *trc_name = "";
 	switch (nclx->transfer_characteristics)
 		{
 		case heif_transfer_characteristic_ITU_R_BT_709_5:
@@ -238,7 +237,6 @@ guchar *nclx_to_lcms_profile(const heif_color_profile_nclx *nclx, guint &profile
 			break;
 		}
 
-	(void)trc_name; // @todo Use [[maybe_unused]] since C++17
 	DEBUG_1("nclx transfer characteristic: %s", trc_name);
 
 	if (!profile) return nullptr;

src/command-line-handling.cc

@@ -871,9 +871,10 @@ void gq_log_file(GtkApplication *, GApplicationCommandLine *, GVariantDict *comm
 	command_line->log_file = path_from_utf8(text);
 }
 
-#if HAVE_LUA // @todo Use [[maybe_unused]] for command_line_options_dict since C++17 and merge declarations
-void gq_lua(GtkApplication *, GApplicationCommandLine *app_command_line, GVariantDict *command_line_options_dict, GList *)
+void gq_lua(GtkApplication *, GApplicationCommandLine *app_command_line,
+            [[maybe_unused]] GVariantDict *command_line_options_dict, GList *)
 {
+#if HAVE_LUA
 	const gchar *text;
 	g_variant_dict_lookup(command_line_options_dict, "lua", "&s", &text);
 
@@ -895,13 +896,10 @@ void gq_lua(GtkApplication *, GApplicationCommandLine *app_command_line, GVarian
 		{
 		g_application_command_line_print(app_command_line, _("lua error: no data\n"));
 		}
-}
 #else
-void gq_lua(GtkApplication *, GApplicationCommandLine *app_command_line, GVariantDict *, GList *)
-{
 	g_application_command_line_print(app_command_line, _("Lua is not available\n"));
-}
 #endif
+}
 
 void gq_new_window(GtkApplication *, GApplicationCommandLine *app_command_line, GVariantDict *, GList *)
 {

src/jpeg-parser.cc

@@ -304,9 +304,8 @@ MPOData jpeg_get_mpo_data(const guchar *data, guint size)
 	                       [size](MPOEntry &mpe){ return mpe.offset + mpe.length > size; });
 	if (it != mpo.images.end())
 		{
-		const guint mpe_size = it->offset + it->length;
+		[[maybe_unused]] const guint mpe_size = it->offset + it->length;
 		mpo.images.erase(it, mpo.images.end());
-		(void)mpe_size; // @todo Use [[maybe_unused]] since C++17
 		DEBUG_1("MPO file truncated to %u valid images, %u %u", mpo.images.size(), mpe_size, size);
 		}
 

src/main.cc

@@ -216,7 +216,6 @@ void sig_handler_cb(int signo, siginfo_t *info, void *)
 	gint i = 0;
 	guint64 addr;
 	guint64 char_index;
-	ssize_t len;
 #if HAVE_EXECINFO_H
 	gint bt_size;
 	void *bt[1024];
@@ -271,6 +270,7 @@ void sig_handler_cb(int signo, siginfo_t *info, void *)
 		i++;
 		}
 
+	[[maybe_unused]] ssize_t len;
 	len = write(STDERR_FILENO, "Geeqie fatal error\n", 19);
 	len = write(STDERR_FILENO, "Signal: ", 8);
 	len = write(STDERR_FILENO, signal_name, strlen(signal_name));
@@ -309,8 +309,6 @@ void sig_handler_cb(int signo, siginfo_t *info, void *)
 	backtrace_symbols_fd(bt, bt_size, STDERR_FILENO);
 #endif
 
-	(void)len; // @todo Use [[maybe_unused]] since C++17
-
 	exit(EXIT_FAILURE);
 }
 #else /* defined(SA_SIGINFO) */
@@ -672,15 +670,14 @@ void exit_program_write_metadata_cb(gint success, const gchar *)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-function"
 #if defined(SIGBUS) && defined(SA_SIGINFO)
-void sigbus_handler_cb_unused(int, siginfo_t *info, void *)
+void sigbus_handler_cb_unused(int, [[maybe_unused]] siginfo_t *info, void *)
 {
 	/*
 	 * @FIXME Design and implement a POSIX-acceptable approach,
 	 * after first documenting the sitations where SIGBUS occurs.
 	 * See https://github.com/BestImageViewer/geeqie/issues/1052 for discussion
 	 */
 
-	(void)info; // @todo Use [[maybe_unused]] since C++17
 	DEBUG_1("SIGBUS %p NOT HANDLED", info->si_addr);
 	exit(EXIT_FAILURE);
 }

src/rcfile.cc

@@ -1799,12 +1799,11 @@ static void start_element(GMarkupParseContext *,
 }
 
 static void end_element(GMarkupParseContext *,
-                        const gchar *element_name,
+                        [[maybe_unused]] const gchar *element_name,
                         gpointer user_data,
                         GError **)
 {
 	auto parser_data = static_cast<GQParserData *>(user_data);
-	(void)element_name; // @todo Use [[maybe_unused]] since C++17
 	DEBUG_2("end %s", element_name);
 
 	parser_data->end_func();

src/ui-fileops.cc

@@ -381,8 +381,7 @@ gboolean copy_file_attributes(const gchar *s, const gchar *t, gint perms, gint m
 		{
 		/* Ignores chown errors, while still doing chown
 		   (so root still can copy files preserving ownership) */
-		int err = chown(tl, st.st_uid, st.st_gid);
-		(void)err; // @todo Use [[maybe_unused]] since C++17
+		[[maybe_unused]] int err = chown(tl, st.st_uid, st.st_gid);
 
 		if (chmod(tl, st.st_mode) < 0)
 			{