GCC Code Coverage Report

Line	Branch	Decision	Exec	Source
1				/*
2				** $Id: loadlib.c $
3				** Dynamic library loader for Lua
4				** See Copyright Notice in lua.h
5				**
6				** This module contains an implementation of loadlib for Unix systems
7				** that have dlfcn, an implementation for Windows, and a stub for other
8				** systems.
9				*/
10
11				#define loadlib_c
12				#define LUA_LIB
13
14				#include "lprefix.h"
15
16
17				#include <stdio.h>
18				#include <stdlib.h>
19				#include <string.h>
20
21				#include "lua.h"
22
23				#include "lauxlib.h"
24				#include "lualib.h"
25
26
27				/*
28				** LUA_IGMARK is a mark to ignore all before it when building the
29				** luaopen_ function name.
30				*/
31				#if !defined (LUA_IGMARK)
32				#define LUA_IGMARK "-"
33				#endif
34
35
36				/*
37				** LUA_CSUBSEP is the character that replaces dots in submodule names
38				** when searching for a C loader.
39				** LUA_LSUBSEP is the character that replaces dots in submodule names
40				** when searching for a Lua loader.
41				*/
42				#if !defined(LUA_CSUBSEP)
43				#define LUA_CSUBSEP LUA_DIRSEP
44				#endif
45
46				#if !defined(LUA_LSUBSEP)
47				#define LUA_LSUBSEP LUA_DIRSEP
48				#endif
49
50
51				/* prefix for open functions in C libraries */
52				#define LUA_POF "luaopen_"
53
54				/* separator for open functions in C libraries */
55				#define LUA_OFSEP "_"
56
57
58				/*
59				** key for table in the registry that keeps handles
60				** for all loaded C libraries
61				*/
62				static const char *const CLIBS = "_CLIBS";
63
64				#define LIB_FAIL "open"
65
66
67				#define setprogdir(L) ((void)0)
68
69
70				/*
71				** Special type equivalent to '(void*)' for functions in gcc
72				** (to suppress warnings when converting function pointers)
73				*/
74				typedef void (*voidf)(void);
75
76
77				/*
78				** system-dependent functions
79				*/
80
81				/*
82				** unload library 'lib'
83				*/
84				static void lsys_unloadlib (void *lib);
85
86				/*
87				** load C library in file 'path'. If 'seeglb', load with all names in
88				** the library global.
89				** Returns the library; in case of error, returns NULL plus an
90				** error string in the stack.
91				*/
92				static void *lsys_load (lua_State *L, const char *path, int seeglb);
93
94				/*
95				** Try to find a function named 'sym' in library 'lib'.
96				** Returns the function; in case of error, returns NULL plus an
97				** error string in the stack.
98				*/
99				static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
100
101
102
103
104				#if defined(LUA_USE_DLOPEN) /* { */
105				/*
106				** {========================================================================
107				** This is an implementation of loadlib based on the dlfcn interface.
108				** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
109				** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
110				** as an emulation layer on top of native functions.
111				** =========================================================================
112				*/
113
114				#include <dlfcn.h>
115
116				/*
117				** Macro to convert pointer-to-void* to pointer-to-function. This cast
118				** is undefined according to ISO C, but POSIX assumes that it works.
119				** (The '__extension__' in gnu compilers is only to avoid warnings.)
120				*/
121				#if defined(__GNUC__)
122				#define cast_func(p) (__extension__ (lua_CFunction)(p))
123				#else
124				#define cast_func(p) ((lua_CFunction)(p))
125				#endif
126
127
128				static void lsys_unloadlib (void *lib) {
129				dlclose(lib);
130				}
131
132
133				static void *lsys_load (lua_State *L, const char *path, int seeglb) {
134				void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
135				if (l_unlikely(lib == NULL))
136				lua_pushstring(L, dlerror());
137				return lib;
138				}
139
140
141				static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
142				lua_CFunction f = cast_func(dlsym(lib, sym));
143				if (l_unlikely(f == NULL))
144				lua_pushstring(L, dlerror());
145				return f;
146				}
147
148				/* }====================================================== */
149
150
151
152				#elif defined(LUA_DL_DLL) /* }{ */
153				/*
154				** {======================================================================
155				** This is an implementation of loadlib for Windows using native functions.
156				** =======================================================================
157				*/
158
159				#include <windows.h>
160
161
162				/*
163				** optional flags for LoadLibraryEx
164				*/
165				#if !defined(LUA_LLE_FLAGS)
166				#define LUA_LLE_FLAGS 0
167				#endif
168
169
170				#undef setprogdir
171
172
173				/*
174				** Replace in the path (on the top of the stack) any occurrence
175				** of LUA_EXEC_DIR with the executable's path.
176				*/
177				static void setprogdir (lua_State *L) {
178				char buff[MAX_PATH + 1];
179				char *lb;
180				DWORD nsize = sizeof(buff)/sizeof(char);
181				DWORD n = GetModuleFileNameA(NULL, buff, nsize); /* get exec. name */
182				if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
183				luaL_error(L, "unable to get ModuleFileName");
184				else {
185				*lb = '\0'; /* cut name on the last '\\' to get the path */
186				luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff);
187				lua_remove(L, -2); /* remove original string */
188				}
189				}
190
191
192
193
194				static void pusherror (lua_State *L) {
195				int error = GetLastError();
196				char buffer[128];
197				if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
198				NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL))
199				lua_pushstring(L, buffer);
200				else
201				lua_pushfstring(L, "system error %d\n", error);
202				}
203
204				static void lsys_unloadlib (void *lib) {
205				FreeLibrary((HMODULE)lib);
206				}
207
208
209				static void *lsys_load (lua_State *L, const char *path, int seeglb) {
210				HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
211				(void)(seeglb); /* not used: symbols are 'global' by default */
212				if (lib == NULL) pusherror(L);
213				return lib;
214				}
215
216
217				static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
218				lua_CFunction f = (lua_CFunction)(voidf)GetProcAddress((HMODULE)lib, sym);
219				if (f == NULL) pusherror(L);
220				return f;
221				}
222
223				/* }====================================================== */
224
225
226				#else /* }{ */
227				/*
228				** {======================================================
229				** Fallback for other systems
230				** =======================================================
231				*/
232
233				#undef LIB_FAIL
234				#define LIB_FAIL "absent"
235
236
237				#define DLMSG "dynamic libraries not enabled; check your Lua installation"
238
239
240			✗	static void lsys_unloadlib (void *lib) {
241				(void)(lib); /* not used */
242			✗	}
243
244
245			✗	static void *lsys_load (lua_State *L, const char *path, int seeglb) {
246				(void)(path); (void)(seeglb); /* not used */
247			✗	lua_pushliteral(L, DLMSG);
248			✗	return NULL;
249				}
250
251
252			✗	static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
253				(void)(lib); (void)(sym); /* not used */
254			✗	lua_pushliteral(L, DLMSG);
255			✗	return NULL;
256				}
257
258				/* }====================================================== */
259				#endif /* } */
260
261
262				/*
263				** {==================================================================
264				** Set Paths
265				** ===================================================================
266				*/
267
268				/*
269				** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment
270				** variables that Lua check to set its paths.
271				*/
272				#if !defined(LUA_PATH_VAR)
273				#define LUA_PATH_VAR "LUA_PATH"
274				#endif
275
276				#if !defined(LUA_CPATH_VAR)
277				#define LUA_CPATH_VAR "LUA_CPATH"
278				#endif
279
280
281
282				/*
283				** return registry.LUA_NOENV as a boolean
284				*/
285			✗	static int noenv (lua_State *L) {
286				int b;
287			✗	lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
288			✗	b = lua_toboolean(L, -1);
289			✗	lua_pop(L, 1); /* remove value */
290			✗	return b;
291				}
292
293
294				/*
295				** Set a path
296				*/
297			✗	static void setpath (lua_State *L, const char *fieldname,
298				const char *envname,
299				const char *dft) {
300				const char *dftmark;
301			✗	const char *nver = lua_pushfstring(L, "%s%s", envname, LUA_VERSUFFIX);
302			✗	const char *path = getenv(nver); /* try versioned name */
303			✗	if (path == NULL) /* no versioned environment variable? */
304			✗	path = getenv(envname); /* try unversioned name */
305			✗	if (path == NULL || noenv(L)) /* no environment variable? */
306			✗	lua_pushstring(L, dft); /* use default */
307			✗	else if ((dftmark = strstr(path, LUA_PATH_SEP LUA_PATH_SEP)) == NULL)
308			✗	lua_pushstring(L, path); /* nothing to change */
309				else { /* path contains a ";;": insert default path in its place */
310			✗	size_t len = strlen(path);
311				luaL_Buffer b;
312			✗	luaL_buffinit(L, &b);
313			✗	if (path < dftmark) { /* is there a prefix before ';;'? */
314			✗	luaL_addlstring(&b, path, dftmark - path); /* add it */
315			✗	luaL_addchar(&b, *LUA_PATH_SEP);
316				}
317			✗	luaL_addstring(&b, dft); /* add default */
318			✗	if (dftmark < path + len - 2) { /* is there a suffix after ';;'? */
319			✗	luaL_addchar(&b, *LUA_PATH_SEP);
320			✗	luaL_addlstring(&b, dftmark + 2, (path + len - 2) - dftmark);
321				}
322			✗	luaL_pushresult(&b);
323				}
324				setprogdir(L);
325			✗	lua_setfield(L, -3, fieldname); /* package[fieldname] = path value */
326			✗	lua_pop(L, 1); /* pop versioned variable name ('nver') */
327			✗	}
328
329				/* }================================================================== */
330
331
332				/*
333				** return registry.CLIBS[path]
334				*/
335			✗	static void *checkclib (lua_State *L, const char *path) {
336				void *plib;
337			✗	lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
338			✗	lua_getfield(L, -1, path);
339			✗	plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */
340			✗	lua_pop(L, 2); /* pop CLIBS table and 'plib' */
341			✗	return plib;
342				}
343
344
345				/*
346				** registry.CLIBS[path] = plib -- for queries
347				** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
348				*/
349			✗	static void addtoclib (lua_State *L, const char *path, void *plib) {
350			✗	lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
351			✗	lua_pushlightuserdata(L, plib);
352			✗	lua_pushvalue(L, -1);
353			✗	lua_setfield(L, -3, path); /* CLIBS[path] = plib */
354			✗	lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
355			✗	lua_pop(L, 1); /* pop CLIBS table */
356			✗	}
357
358
359				/*
360				** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
361				** handles in list CLIBS
362				*/
363			✗	static int gctm (lua_State *L) {
364			✗	lua_Integer n = luaL_len(L, 1);
365			✗	for (; n >= 1; n--) { /* for each handle, in reverse order */
366			✗	lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
367			✗	lsys_unloadlib(lua_touserdata(L, -1));
368			✗	lua_pop(L, 1); /* pop handle */
369				}
370			✗	return 0;
371				}
372
373
374
375				/* error codes for 'lookforfunc' */
376				#define ERRLIB 1
377				#define ERRFUNC 2
378
379				/*
380				** Look for a C function named 'sym' in a dynamically loaded library
381				** 'path'.
382				** First, check whether the library is already loaded; if not, try
383				** to load it.
384				** Then, if 'sym' is '*', return true (as library has been loaded).
385				** Otherwise, look for symbol 'sym' in the library and push a
386				** C function with that symbol.
387				** Return 0 and 'true' or a function in the stack; in case of
388				** errors, return an error code and an error message in the stack.
389				*/
390			✗	static int lookforfunc (lua_State *L, const char *path, const char *sym) {
391			✗	void *reg = checkclib(L, path); /* check loaded C libraries */
392			✗	if (reg == NULL) { /* must load library? */
393			✗	reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */
394			✗	if (reg == NULL) return ERRLIB; /* unable to load library */
395			✗	addtoclib(L, path, reg);
396				}
397			✗	if (*sym == '*') { /* loading only library (no function)? */
398			✗	lua_pushboolean(L, 1); /* return 'true' */
399			✗	return 0; /* no errors */
400				}
401				else {
402			✗	lua_CFunction f = lsys_sym(L, reg, sym);
403			✗	if (f == NULL)
404			✗	return ERRFUNC; /* unable to find function */
405			✗	lua_pushcfunction(L, f); /* else create new function */
406			✗	return 0; /* no errors */
407				}
408				}
409
410
411			✗	static int ll_loadlib (lua_State *L) {
412			✗	const char *path = luaL_checkstring(L, 1);
413			✗	const char *init = luaL_checkstring(L, 2);
414			✗	int stat = lookforfunc(L, path, init);
415			✗	if (l_likely(stat == 0)) /* no errors? */
416			✗	return 1; /* return the loaded function */
417				else { /* error; error message is on stack top */
418			✗	luaL_pushfail(L);
419			✗	lua_insert(L, -2);
420			✗	lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init");
421			✗	return 3; /* return fail, error message, and where */
422				}
423				}
424
425
426
427				/*
428				** {======================================================
429				** 'require' function
430				** =======================================================
431				*/
432
433
434			✗	static int readable (const char *filename) {
435			✗	FILE *f = fopen(filename, "r"); /* try to open file */
436			✗	if (f == NULL) return 0; /* open failed */
437			✗	fclose(f);
438			✗	return 1;
439				}
440
441
442				/*
443				** Get the next name in '*path' = 'name1;name2;name3;...', changing
444				** the ending ';' to '\0' to create a zero-terminated string. Return
445				** NULL when list ends.
446				*/
447			✗	static const char *getnextfilename (char **path, char *end) {
448				char *sep;
449			✗	char *name = *path;
450			✗	if (name == end)
451			✗	return NULL; /* no more names */
452			✗	else if (*name == '\0') { /* from previous iteration? */
453			✗	*name = *LUA_PATH_SEP; /* restore separator */
454			✗	name++; /* skip it */
455				}
456			✗	sep = strchr(name, *LUA_PATH_SEP); /* find next separator */
457			✗	if (sep == NULL) /* separator not found? */
458			✗	sep = end; /* name goes until the end */
459			✗	*sep = '\0'; /* finish file name */
460			✗	*path = sep; /* will start next search from here */
461			✗	return name;
462				}
463
464
465				/*
466				** Given a path such as ";blabla.so;blublu.so", pushes the string
467				**
468				** no file 'blabla.so'
469				** no file 'blublu.so'
470				*/
471			✗	static void pusherrornotfound (lua_State *L, const char *path) {
472				luaL_Buffer b;
473			✗	luaL_buffinit(L, &b);
474			✗	luaL_addstring(&b, "no file '");
475			✗	luaL_addgsub(&b, path, LUA_PATH_SEP, "'\n\tno file '");
476			✗	luaL_addstring(&b, "'");
477			✗	luaL_pushresult(&b);
478			✗	}
479
480
481			✗	static const char *searchpath (lua_State *L, const char *name,
482				const char *path,
483				const char *sep,
484				const char *dirsep) {
485				luaL_Buffer buff;
486				char *pathname; /* path with name inserted */
487				char *endpathname; /* its end */
488				const char *filename;
489				/* separator is non-empty and appears in 'name'? */
490			✗	if (*sep != '\0' && strchr(name, *sep) != NULL)
491			✗	name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
492			✗	luaL_buffinit(L, &buff);
493				/* add path to the buffer, replacing marks ('?') with the file name */
494			✗	luaL_addgsub(&buff, path, LUA_PATH_MARK, name);
495			✗	luaL_addchar(&buff, '\0');
496			✗	pathname = luaL_buffaddr(&buff); /* writable list of file names */
497			✗	endpathname = pathname + luaL_bufflen(&buff) - 1;
498			✗	while ((filename = getnextfilename(&pathname, endpathname)) != NULL) {
499			✗	if (readable(filename)) /* does file exist and is readable? */
500			✗	return lua_pushstring(L, filename); /* save and return name */
501				}
502			✗	luaL_pushresult(&buff); /* push path to create error message */
503			✗	pusherrornotfound(L, lua_tostring(L, -1)); /* create error message */
504			✗	return NULL; /* not found */
505				}
506
507
508			✗	static int ll_searchpath (lua_State *L) {
509			✗	const char *f = searchpath(L, luaL_checkstring(L, 1),
510				luaL_checkstring(L, 2),
511				luaL_optstring(L, 3, "."),
512				luaL_optstring(L, 4, LUA_DIRSEP));
513			✗	if (f != NULL) return 1;
514				else { /* error message is on top of the stack */
515			✗	luaL_pushfail(L);
516			✗	lua_insert(L, -2);
517			✗	return 2; /* return fail + error message */
518				}
519				}
520
521
522			✗	static const char *findfile (lua_State *L, const char *name,
523				const char *pname,
524				const char *dirsep) {
525				const char *path;
526			✗	lua_getfield(L, lua_upvalueindex(1), pname);
527			✗	path = lua_tostring(L, -1);
528			✗	if (l_unlikely(path == NULL))
529			✗	luaL_error(L, "'package.%s' must be a string", pname);
530			✗	return searchpath(L, name, path, ".", dirsep);
531				}
532
533
534			✗	static int checkload (lua_State *L, int stat, const char *filename) {
535			✗	if (l_likely(stat)) { /* module loaded successfully? */
536			✗	lua_pushstring(L, filename); /* will be 2nd argument to module */
537			✗	return 2; /* return open function and file name */
538				}
539				else
540			✗	return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s",
541				lua_tostring(L, 1), filename, lua_tostring(L, -1));
542				}
543
544
545			✗	static int searcher_Lua (lua_State *L) {
546				const char *filename;
547			✗	const char *name = luaL_checkstring(L, 1);
548			✗	filename = findfile(L, name, "path", LUA_LSUBSEP);
549			✗	if (filename == NULL) return 1; /* module not found in this path */
550			✗	return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
551				}
552
553
554				/*
555				** Try to find a load function for module 'modname' at file 'filename'.
556				** First, change '.' to '_' in 'modname'; then, if 'modname' has
557				** the form X-Y (that is, it has an "ignore mark"), build a function
558				** name "luaopen_X" and look for it. (For compatibility, if that
559				** fails, it also tries "luaopen_Y".) If there is no ignore mark,
560				** look for a function named "luaopen_modname".
561				*/
562			✗	static int loadfunc (lua_State *L, const char *filename, const char *modname) {
563				const char *openfunc;
564				const char *mark;
565			✗	modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
566			✗	mark = strchr(modname, *LUA_IGMARK);
567			✗	if (mark) {
568				int stat;
569			✗	openfunc = lua_pushlstring(L, modname, mark - modname);
570			✗	openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
571			✗	stat = lookforfunc(L, filename, openfunc);
572			✗	if (stat != ERRFUNC) return stat;
573			✗	modname = mark + 1; /* else go ahead and try old-style name */
574				}
575			✗	openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
576			✗	return lookforfunc(L, filename, openfunc);
577				}
578
579
580			✗	static int searcher_C (lua_State *L) {
581			✗	const char *name = luaL_checkstring(L, 1);
582			✗	const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
583			✗	if (filename == NULL) return 1; /* module not found in this path */
584			✗	return checkload(L, (loadfunc(L, filename, name) == 0), filename);
585				}
586
587
588			✗	static int searcher_Croot (lua_State *L) {
589				const char *filename;
590			✗	const char *name = luaL_checkstring(L, 1);
591			✗	const char *p = strchr(name, '.');
592				int stat;
593			✗	if (p == NULL) return 0; /* is root */
594			✗	lua_pushlstring(L, name, p - name);
595			✗	filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP);
596			✗	if (filename == NULL) return 1; /* root not found */
597			✗	if ((stat = loadfunc(L, filename, name)) != 0) {
598			✗	if (stat != ERRFUNC)
599			✗	return checkload(L, 0, filename); /* real error */
600				else { /* open function not found */
601			✗	lua_pushfstring(L, "no module '%s' in file '%s'", name, filename);
602			✗	return 1;
603				}
604				}
605			✗	lua_pushstring(L, filename); /* will be 2nd argument to module */
606			✗	return 2;
607				}
608
609
610			✗	static int searcher_preload (lua_State *L) {
611			✗	const char *name = luaL_checkstring(L, 1);
612			✗	lua_getfield(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
613			✗	if (lua_getfield(L, -1, name) == LUA_TNIL) { /* not found? */
614			✗	lua_pushfstring(L, "no field package.preload['%s']", name);
615			✗	return 1;
616				}
617				else {
618			✗	lua_pushliteral(L, ":preload:");
619			✗	return 2;
620				}
621				}
622
623
624			✗	static void findloader (lua_State *L, const char *name) {
625				int i;
626				luaL_Buffer msg; /* to build error message */
627				/* push 'package.searchers' to index 3 in the stack */
628			✗	if (l_unlikely(lua_getfield(L, lua_upvalueindex(1), "searchers")
629				!= LUA_TTABLE))
630			✗	luaL_error(L, "'package.searchers' must be a table");
631			✗	luaL_buffinit(L, &msg);
632				/* iterate over available searchers to find a loader */
633			✗	for (i = 1; ; i++) {
634			✗	luaL_addstring(&msg, "\n\t"); /* error-message prefix */
635			✗	if (l_unlikely(lua_rawgeti(L, 3, i) == LUA_TNIL)) { /* no more searchers? */
636			✗	lua_pop(L, 1); /* remove nil */
637			✗	luaL_buffsub(&msg, 2); /* remove prefix */
638			✗	luaL_pushresult(&msg); /* create error message */
639			✗	luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1));
640				}
641			✗	lua_pushstring(L, name);
642			✗	lua_call(L, 1, 2); /* call it */
643			✗	if (lua_isfunction(L, -2)) /* did it find a loader? */
644			✗	return; /* module loader found */
645			✗	else if (lua_isstring(L, -2)) { /* searcher returned error message? */
646			✗	lua_pop(L, 1); /* remove extra return */
647			✗	luaL_addvalue(&msg); /* concatenate error message */
648				}
649				else { /* no error message */
650			✗	lua_pop(L, 2); /* remove both returns */
651			✗	luaL_buffsub(&msg, 2); /* remove prefix */
652				}
653				}
654				}
655
656
657			✗	static int ll_require (lua_State *L) {
658			✗	const char *name = luaL_checkstring(L, 1);
659			✗	lua_settop(L, 1); /* LOADED table will be at index 2 */
660			✗	lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
661			✗	lua_getfield(L, 2, name); /* LOADED[name] */
662			✗	if (lua_toboolean(L, -1)) /* is it there? */
663			✗	return 1; /* package is already loaded */
664				/* else must load package */
665			✗	lua_pop(L, 1); /* remove 'getfield' result */
666			✗	findloader(L, name);
667			✗	lua_rotate(L, -2, 1); /* function <-> loader data */
668			✗	lua_pushvalue(L, 1); /* name is 1st argument to module loader */
669			✗	lua_pushvalue(L, -3); /* loader data is 2nd argument */
670				/* stack: ...; loader data; loader function; mod. name; loader data */
671			✗	lua_call(L, 2, 1); /* run loader to load module */
672				/* stack: ...; loader data; result from loader */
673			✗	if (!lua_isnil(L, -1)) /* non-nil return? */
674			✗	lua_setfield(L, 2, name); /* LOADED[name] = returned value */
675				else
676			✗	lua_pop(L, 1); /* pop nil */
677			✗	if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */
678			✗	lua_pushboolean(L, 1); /* use true as result */
679			✗	lua_copy(L, -1, -2); /* replace loader result */
680			✗	lua_setfield(L, 2, name); /* LOADED[name] = true */
681				}
682			✗	lua_rotate(L, -2, 1); /* loader data <-> module result */
683			✗	return 2; /* return module result and loader data */
684				}
685
686				/* }====================================================== */
687
688
689
690
691				static const luaL_Reg pk_funcs[] = {
692				{"loadlib", ll_loadlib},
693				{"searchpath", ll_searchpath},
694				/* placeholders */
695				{"preload", NULL},
696				{"cpath", NULL},
697				{"path", NULL},
698				{"searchers", NULL},
699				{"loaded", NULL},
700				{NULL, NULL}
701				};
702
703
704				static const luaL_Reg ll_funcs[] = {
705				{"require", ll_require},
706				{NULL, NULL}
707				};
708
709
710			✗	static void createsearcherstable (lua_State *L) {
711				static const lua_CFunction searchers[] = {
712				searcher_preload,
713				searcher_Lua,
714				searcher_C,
715				searcher_Croot,
716				NULL
717				};
718				int i;
719				/* create 'searchers' table */
720			✗	lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
721				/* fill it with predefined searchers */
722			✗	for (i=0; searchers[i] != NULL; i++) {
723			✗	lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
724			✗	lua_pushcclosure(L, searchers[i], 1);
725			✗	lua_rawseti(L, -2, i+1);
726				}
727			✗	lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
728			✗	}
729
730
731				/*
732				** create table CLIBS to keep track of loaded C libraries,
733				** setting a finalizer to close all libraries when closing state.
734				*/
735			✗	static void createclibstable (lua_State *L) {
736			✗	luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS); /* create CLIBS table */
737			✗	lua_createtable(L, 0, 1); /* create metatable for CLIBS */
738			✗	lua_pushcfunction(L, gctm);
739			✗	lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */
740			✗	lua_setmetatable(L, -2);
741			✗	}
742
743
744			✗	LUAMOD_API int luaopen_package (lua_State *L) {
745			✗	createclibstable(L);
746			✗	luaL_newlib(L, pk_funcs); /* create 'package' table */
747			✗	createsearcherstable(L);
748				/* set paths */
749			✗	setpath(L, "path", LUA_PATH_VAR, LUA_PATH_DEFAULT);
750			✗	setpath(L, "cpath", LUA_CPATH_VAR, LUA_CPATH_DEFAULT);
751				/* store config information */
752			✗	lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
753				LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
754			✗	lua_setfield(L, -2, "config");
755				/* set field 'loaded' */
756			✗	luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
757			✗	lua_setfield(L, -2, "loaded");
758				/* set field 'preload' */
759			✗	luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_PRELOAD_TABLE);
760			✗	lua_setfield(L, -2, "preload");
761			✗	lua_pushglobaltable(L);
762			✗	lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
763			✗	luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
764			✗	lua_pop(L, 1); /* pop global table */
765			✗	return 1; /* return 'package' table */
766				}
767
768