Add some more changes and extensions from Lua 5.2.

Contributed by François Perrad.

doc/extensions.html

@@ -312,6 +312,20 @@ indexes for varargs.</li>
 <li><tt>debug.getupvalue()</tt> and <tt>debug.setupvalue()</tt> handle
 C&nbsp;functions.</li>
 <li><tt>debug.upvalueid()</tt> and <tt>debug.upvaluejoin()</tt>.</li>
+<li>Lua/C API extensions:
+<tt>lua_upvalueid()</tt>
+<tt>lua_upvaluejoin()</tt>
+<tt>lua_loadx()</tt>
+<tt>luaL_fileresult()</tt>
+<tt>luaL_execresult()</tt>
+<tt>luaL_loadfilex()</tt>
+<tt>luaL_loadbufferx()</tt>
+<tt>luaL_traceback()</tt>
+<tt>luaL_setfuncs()</tt>
+<tt>luaL_pushmodule()</tt>
+<tt>luaL_newlibtable()</tt>
+<tt>luaL_newlib()</tt>
+</li>
 <li>Command line option <tt>-E</tt>.</li>
 <li>Command line checks <tt>__tostring</tt> for errors.</li>
 </ul>
@@ -338,6 +352,7 @@ exit status.</li>
 <li><tt>debug.getuservalue()</tt> and <tt>debug.setuservalue()</tt>.</li>
 <li>Remove <tt>math.mod()</tt>, <tt>string.gfind()</tt>.</li>
 <li><tt>package.searchers</tt>.</li>
+<li><tt>module()</tt> returns the module table.</li>
 </ul>
 <p>
 Note: this provides only partial compatibility with Lua 5.2 at the

src/lauxlib.h

@@ -85,6 +85,9 @@ LUALIB_API int (luaL_loadbufferx) (lua_State *L, const char *buff, size_t sz,
 				   const char *name, const char *mode);
 LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, const char *msg,
 				int level);
+LUALIB_API void (luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup);
+LUALIB_API void (luaL_pushmodule) (lua_State *L, const char *modname,
+				   int sizehint);
 
 
 /*
@@ -114,6 +117,11 @@ LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, const char *msg,
 
 #define luaL_opt(L,f,n,d)	(lua_isnoneornil(L,(n)) ? (d) : f(L,(n)))
 
+/* From Lua 5.2. */
+#define luaL_newlibtable(L, l) \
+	lua_createtable(L, 0, sizeof(l)/sizeof((l)[0]) - 1)
+#define luaL_newlib(L, l)	(luaL_newlibtable(L, l), luaL_setfuncs(L, l, 0))
+
 /*
 ** {======================================================
 ** Generic Buffer manipulation

src/lib_aux.c

@@ -107,38 +107,36 @@ LUALIB_API const char *luaL_findtable(lua_State *L, int idx,
 static int libsize(const luaL_Reg *l)
 {
   int size = 0;
-  for (; l->name; l++) size++;
+  for (; l && l->name; l++) size++;
   return size;
 }
 
+LUALIB_API void luaL_pushmodule(lua_State *L, const char *modname, int sizehint)
+{
+  luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 16);
+  lua_getfield(L, -1, modname);
+  if (!lua_istable(L, -1)) {
+    lua_pop(L, 1);
+    if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, sizehint) != NULL)
+      lj_err_callerv(L, LJ_ERR_BADMODN, modname);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, -3, modname);  /* _LOADED[modname] = new table. */
+  }
+  lua_remove(L, -2);  /* Remove _LOADED table. */
+}
+
 LUALIB_API void luaL_openlib(lua_State *L, const char *libname,
 			     const luaL_Reg *l, int nup)
 {
   lj_lib_checkfpu(L);
   if (libname) {
-    int size = libsize(l);
+    luaL_pushmodule(L, libname, libsize(l));
-    /* check whether lib already exists */
+    lua_insert(L, -(nup + 1));  /* Move module table below upvalues. */
-    luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 16);
-    lua_getfield(L, -1, libname);  /* get _LOADED[libname] */
-    if (!lua_istable(L, -1)) {  /* not found? */
-      lua_pop(L, 1);  /* remove previous result */
-      /* try global variable (and create one if it does not exist) */
-      if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)
-	lj_err_callerv(L, LJ_ERR_BADMODN, libname);
-      lua_pushvalue(L, -1);
-      lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */
-    }
-    lua_remove(L, -2);  /* remove _LOADED table */
-    lua_insert(L, -(nup+1));  /* move library table to below upvalues */
   }
-  for (; l->name; l++) {
+  if (l)
-    int i;
+    luaL_setfuncs(L, l, nup);
-    for (i = 0; i < nup; i++)  /* copy upvalues to the top */
+  else
-      lua_pushvalue(L, -nup);
+    lua_pop(L, nup);  /* Remove upvalues. */
-    lua_pushcclosure(L, l->func, nup);
-    lua_setfield(L, -(nup+2), l->name);
-  }
-  lua_pop(L, nup);  /* remove upvalues */
 }
 
 LUALIB_API void luaL_register(lua_State *L, const char *libname,
@@ -147,6 +145,19 @@ LUALIB_API void luaL_register(lua_State *L, const char *libname,
   luaL_openlib(L, libname, l, 0);
 }
 
+LUALIB_API void luaL_setfuncs(lua_State *L, const luaL_Reg *l, int nup)
+{
+  luaL_checkstack(L, nup, "too many upvalues");
+  for (; l->name; l++) {
+    int i;
+    for (i = 0; i < nup; i++)  /* Copy upvalues to the top. */
+      lua_pushvalue(L, -nup);
+    lua_pushcclosure(L, l->func, nup);
+    lua_setfield(L, -(nup + 2), l->name);
+  }
+  lua_pop(L, nup);  /* Remove upvalues. */
+}
+
 LUALIB_API const char *luaL_gsub(lua_State *L, const char *s,
 				 const char *p, const char *r)
 {

src/lib_package.c

@@ -489,29 +489,19 @@ static void modinit(lua_State *L, const char *modname)
 static int lj_cf_package_module(lua_State *L)
 {
   const char *modname = luaL_checkstring(L, 1);
-  int loaded = lua_gettop(L) + 1;  /* index of _LOADED table */
+  int lastarg = (int)(L->top - L->base);
-  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+  luaL_pushmodule(L, modname, 1);
-  lua_getfield(L, loaded, modname);  /* get _LOADED[modname] */
-  if (!lua_istable(L, -1)) {  /* not found? */
-    lua_pop(L, 1);  /* remove previous result */
-    /* try global variable (and create one if it does not exist) */
-    if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, 1) != NULL)
-      lj_err_callerv(L, LJ_ERR_BADMODN, modname);
-    lua_pushvalue(L, -1);
-    lua_setfield(L, loaded, modname);  /* _LOADED[modname] = new table */
-  }
-  /* check whether table already has a _NAME field */
   lua_getfield(L, -1, "_NAME");
-  if (!lua_isnil(L, -1)) {  /* is table an initialized module? */
+  if (!lua_isnil(L, -1)) {  /* Module already initialized? */
     lua_pop(L, 1);
-  } else {  /* no; initialize it */
+  } else {
     lua_pop(L, 1);
     modinit(L, modname);
   }
   lua_pushvalue(L, -1);
   setfenv(L);
-  dooptions(L, loaded - 1);
+  dooptions(L, lastarg);
-  return 0;
+  return LJ_52;
 }
 
 static int lj_cf_package_seeall(lua_State *L)

src/luaconf.h

@@ -79,7 +79,7 @@
 #define LUA_IGMARK	"-"
 #define LUA_PATH_CONFIG \
   LUA_DIRSEP "\n" LUA_PATHSEP "\n" LUA_PATH_MARK "\n" \
-  LUA_EXECDIR "\n" LUA_IGMARK
+  LUA_EXECDIR "\n" LUA_IGMARK "\n"
 
 /* Quoting in error messages. */
 #define LUA_QL(x)	"'" x "'"