commit c229ed597f939eacfe1e9b7113e2a082fe93a3ae
parent 16b41105215e3cad719ffb121caca0d065e05b6e
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 16 Jul 2014 11:51:11 -0300
'requiref' checks 'package.loaded' before loading a module
Diffstat:
2 files changed, 22 insertions(+), 13 deletions(-)
diff --git a/lauxlib.c b/lauxlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lauxlib.c,v 1.263 2014/05/12 21:44:17 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.264 2014/06/26 17:25:11 roberto Exp roberto $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/
@@ -883,22 +883,26 @@ LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
/*
-** stripped-down 'require'. Calls 'openf' to open a module,
-** registers the result in 'package.loaded' table and, if 'glb'
-** is true, also registers the result in the global table.
+** Stripped-down 'require': After checking "loaded" table, calls 'openf'
+** to open a module, registers the result in 'package.loaded' table and,
+** if 'glb' is true, also registers the result in the global table.
** Leaves resulting module on the top.
*/
LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
lua_CFunction openf, int glb) {
- lua_pushcfunction(L, openf);
- lua_pushstring(L, modname); /* argument to open function */
- lua_call(L, 1, 1); /* open module */
luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
- lua_pushvalue(L, -2); /* make copy of module (call result) */
- lua_setfield(L, -2, modname); /* _LOADED[modname] = module */
- lua_pop(L, 1); /* remove _LOADED table */
+ lua_getfield(L, -1, modname); /* _LOADED[modname] */
+ if (!lua_toboolean(L, -1)) { /* package not already loaded? */
+ lua_pop(L, 1); /* remove field */
+ lua_pushcfunction(L, openf);
+ lua_pushstring(L, modname); /* argument to open function */
+ lua_call(L, 1, 1); /* call 'openf' to open module */
+ lua_pushvalue(L, -1); /* make copy of module (call result) */
+ lua_setfield(L, -3, modname); /* _LOADED[modname] = module */
+ }
+ lua_remove(L, -2); /* remove _LOADED table */
if (glb) {
- lua_pushvalue(L, -1); /* copy of 'mod' */
+ lua_pushvalue(L, -1); /* copy of module */
lua_setglobal(L, modname); /* _G[modname] = module */
}
}
diff --git a/ltests.c b/ltests.c
@@ -1,5 +1,5 @@
/*
-** $Id: ltests.c,v 2.173 2014/06/19 18:29:30 roberto Exp roberto $
+** $Id: ltests.c,v 2.174 2014/06/26 17:25:11 roberto Exp roberto $
** Internal Module for Debugging of the Lua Implementation
** See Copyright Notice in lua.h
*/
@@ -839,7 +839,12 @@ static int loadlib (lua_State *L) {
};
lua_State *L1 = getstate(L);
int i;
- luaL_requiref(L1, "package", luaopen_package, 1);
+ luaL_requiref(L1, "package", luaopen_package, 0);
+ lua_assert(lua_type(L1, -1) == LUA_TTABLE);
+ /* 'requiref' should not reload module already loaded... */
+ luaL_requiref(L1, "package", NULL, 1); /* seg. fault if it reloads */
+ /* ...but should return the same module */
+ lua_assert(lua_compare(L1, -1, -2, LUA_OPEQ));
luaL_getsubtable(L1, LUA_REGISTRYINDEX, "_PRELOAD");
for (i = 0; libs[i].name; i++) {
lua_pushcfunction(L1, libs[i].func);