Modernize luaW_getglobal

The variadic form now uses a variadic template, and a vector form has been added.
Since the nullptr sentinel argument is no longer required, it has been removed from all calls.

src/ai/lua/core.cpp

@@ -820,7 +820,7 @@ static int impl_ai_aspect_get(lua_State* L)
 		(void) aspect;
 	} else if(typesafe_aspect<unit_advancements_aspect>* aspect = try_aspect_as<unit_advancements_aspect>(iter->second)) {
 		const unit_advancements_aspect& val = aspect->get();
-		int my_side = luaW_getglobal(L, "ai", "side", nullptr) - 1;
+		int my_side = luaW_getglobal(L, "ai", "side") - 1;
 		lua_newtable(L);
 		for (unit_map::const_iterator u = resources::units->begin(); u != resources::units->end(); ++u) {
 			if (!u.valid() || u->side() != my_side) {

src/scripting/game_lua_kernel.cpp

@@ -4075,7 +4075,7 @@ namespace {
 	{
 		lua_State *L = mState;
 		config cfg;
-		if (!luaW_getglobal(L, "wesnoth", "theme_items", name.c_str(), nullptr))
+		if (!luaW_getglobal(L, "wesnoth", "theme_items", name))
 			return cfg;
 		if (!luaW_pcall(L, 0, 1)) return cfg;
 		luaW_toconfig(L, -1, cfg);
@@ -4546,7 +4546,7 @@ game_lua_kernel::game_lua_kernel(CVideo * video, game_state & gs, play_controlle
 	{
 		set_wml_action(handler.first, handler.second);
 	}
-	luaW_getglobal(L, "wesnoth", "effects", nullptr);
+	luaW_getglobal(L, "wesnoth", "effects");
 	BOOST_FOREACH(const std::string& effect, unit::builtin_effects) {
 		lua_pushstring(L, effect.c_str());
 		push_builtin_effect();
@@ -4678,7 +4678,7 @@ void game_lua_kernel::load_game(const config& level)
 {
 	lua_State *L = mState;
 
-	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_load", nullptr))
+	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_load"))
 		return;
 
 	lua_newtable(L);
@@ -4705,7 +4705,7 @@ void game_lua_kernel::save_game(config &cfg)
 {
 	lua_State *L = mState;
 
-	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_save", nullptr))
+	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_save"))
 		return;
 
 	if (!luaW_pcall(L, 0, 1, false))
@@ -4743,7 +4743,7 @@ bool game_lua_kernel::run_event(game_events::queued_event const &ev)
 {
 	lua_State *L = mState;
 
-	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_event", nullptr))
+	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_event"))
 		return false;
 
 	queued_event_context dummy(&ev, queued_events_);
@@ -4847,7 +4847,7 @@ bool game_lua_kernel::run_wml_action(std::string const &cmd, vconfig const &cfg,
 	lua_State *L = mState;
 
 
-	if (!luaW_getglobal(L, "wesnoth", "wml_actions", cmd.c_str(), nullptr))
+	if (!luaW_getglobal(L, "wesnoth", "wml_actions", cmd))
 		return false;
 
 	queued_event_context dummy(&ev, queued_events_);
@@ -4868,7 +4868,7 @@ bool game_lua_kernel::run_wml_conditional(std::string const &cmd, vconfig const
 	lua_State *L = mState;
 
 
-	if (!luaW_getglobal(L, "wesnoth", "wml_conditionals", cmd.c_str(), nullptr)) {
+	if (!luaW_getglobal(L, "wesnoth", "wml_conditionals", cmd)) {
 		std::string err_msg = "unknown conditional wml: [";
 		err_msg += cmd;
 		err_msg += "]";
@@ -4896,7 +4896,7 @@ bool game_lua_kernel::run_filter(char const *name, unit const &u)
 	if (!ui.valid()) return false;
 
 	// Get the user filter by name.
-	if(!luaW_getglobal(L, name, nullptr))
+	if(!luaW_getglobal(L, name))
 	{
 		std::string message = std::string() + "function " + name + " not found";
 		log_error(message.c_str(), "Lua SUF Error");
@@ -4928,7 +4928,7 @@ std::string game_lua_kernel::apply_effect(const std::string& name, unit& u, cons
 	// (Note: The unit needs to be on the stack twice to prevent untimely GC.)
 	luaW_pushconfig(L, cfg);
 	// Stack: unit, cfg
-	if(luaW_getglobal(L, "wesnoth", "effects", name.c_str(), nullptr)) {
+	if(luaW_getglobal(L, "wesnoth", "effects", name)) {
 		map_locker(this);
 		// Stack: unit, cfg, effect
 		if(lua_istable(L, -1)) {
@@ -4997,7 +4997,7 @@ void game_lua_kernel::mouse_over_hex_callback(const map_location& loc)
 {
 	lua_State *L = mState;
 
-	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_mouse_move", nullptr)) {
+	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_mouse_move")) {
 		return;
 	}
 	lua_push(L, loc.x + 1);
@@ -5010,7 +5010,7 @@ void game_lua_kernel::select_hex_callback(const map_location& loc)
 {
 	lua_State *L = mState;
 
-	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_mouse_action", nullptr)) {
+	if (!luaW_getglobal(L, "wesnoth", "game_events", "on_mouse_action")) {
 		return;
 	}
 	lua_push(L, loc.x + 1);

src/scripting/lua_common.cpp

@@ -790,30 +790,22 @@ vconfig luaW_checkvconfig(lua_State *L, int index, bool allow_missing)
 	return result;
 }
 
-
-#ifdef __GNUC__
-__attribute__((sentinel))
-#endif
-bool luaW_getglobal(lua_State *L, ...)
+bool luaW_getglobal(lua_State *L, const std::vector<std::string>& path)
 {
 	lua_pushglobaltable(L);
-	va_list ap;
-	va_start(ap, L);
-	while (const char *s = va_arg(ap, const char *))
+	for (const std::string& s : path)
 	{
 		if (!lua_istable(L, -1)) goto discard;
-		lua_pushstring(L, s);
+		lua_pushlstring(L, s.c_str(), s.size());
 		lua_rawget(L, -2);
 		lua_remove(L, -2);
 	}
 
 	if (lua_isnil(L, -1)) {
 		discard:
-		va_end(ap);
 		lua_pop(L, 1);
 		return false;
 	}
-	va_end(ap);
 	return true;
 }
 

src/scripting/lua_common.hpp

@@ -28,6 +28,7 @@ class vconfig;
 #include "scripting/lua_types.hpp"
 #include "variable_info.hpp"
 #include "map/location.hpp"
+#include <vector>
 
 namespace lua_common {
 	int intf_textdomain(lua_State *L);
@@ -139,7 +140,17 @@ vconfig luaW_checkvconfig(lua_State *L, int index, bool allow_missing = false);
  * value is not nil.
  * @return true if an element was pushed.
  */
-bool luaW_getglobal(lua_State *L, ...);
+bool luaW_getglobal(lua_State *L, const std::vector<std::string>& path);
+
+/**
+ * Pushes the value found by following the variadic names (char *), if the
+ * value is not nil.
+ * @return true if an element was pushed.
+ */
+template<typename... T>
+bool luaW_getglobal(lua_State *L, T... path) {
+	return luaW_getglobal(L, std::vector<std::string> {path...} );
+}
 
 bool luaW_toboolean(lua_State *L, int n);