commit 255d59ed5e2743b97626eff57444f44defc39270
parent 925d1b59f931ad3cf23e67f39f6771b9a9e06f5f
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 28 Jul 2014 14:47:28 -0300
some janitorial work (comments, small refactoring)
Diffstat:
| M | loadlib.c | | | 141 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------------- |
1 file changed, 96 insertions(+), 45 deletions(-)
diff --git a/loadlib.c b/loadlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: loadlib.c,v 1.113 2014/03/12 20:57:40 roberto Exp roberto $
+** $Id: loadlib.c,v 1.114 2014/07/16 13:56:14 roberto Exp roberto $
** Dynamic library loader for Lua
** See Copyright Notice in lua.h
**
@@ -97,20 +97,33 @@
#define LIB_FAIL "open"
-
-/* error codes for ll_loadfunc */
-#define ERRLIB 1
-#define ERRFUNC 2
-
#define setprogdir(L) ((void)0)
/*
** system-dependent functions
*/
-static void ll_unloadlib (void *lib);
-static void *ll_load (lua_State *L, const char *path, int seeglb);
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
+
+/*
+** unload library 'lib'
+*/
+static void lsys_unloadlib (void *lib);
+
+/*
+** load C library in file 'path'. If 'seeglb', load with all names in
+** the library global.
+** Returns the library; in case of error, returns NULL plus an
+** error string in the stack.
+*/
+static void *lsys_load (lua_State *L, const char *path, int seeglb);
+
+/*
+** Try to find a function named 'sym' in library 'lib'.
+** Returns the function; in case of error, returns NULL plus an
+** error string in the stack.
+*/
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym);
+
@@ -126,19 +139,19 @@ static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
#include <dlfcn.h>
-static void ll_unloadlib (void *lib) {
+static void lsys_unloadlib (void *lib) {
dlclose(lib);
}
-static void *ll_load (lua_State *L, const char *path, int seeglb) {
+static void *lsys_load (lua_State *L, const char *path, int seeglb) {
void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
if (lib == NULL) lua_pushstring(L, dlerror());
return lib;
}
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
if (f == NULL) lua_pushstring(L, dlerror());
return f;
@@ -190,12 +203,12 @@ static void pusherror (lua_State *L) {
lua_pushfstring(L, "system error %d\n", error);
}
-static void ll_unloadlib (void *lib) {
+static void lsys_unloadlib (void *lib) {
FreeLibrary((HMODULE)lib);
}
-static void *ll_load (lua_State *L, const char *path, int seeglb) {
+static void *lsys_load (lua_State *L, const char *path, int seeglb) {
HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
(void)(seeglb); /* not used: symbols are 'global' by default */
if (lib == NULL) pusherror(L);
@@ -203,7 +216,7 @@ static void *ll_load (lua_State *L, const char *path, int seeglb) {
}
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym);
if (f == NULL) pusherror(L);
return f;
@@ -226,19 +239,19 @@ static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
#define DLMSG "dynamic libraries not enabled; check your Lua installation"
-static void ll_unloadlib (void *lib) {
+static void lsys_unloadlib (void *lib) {
(void)(lib); /* not used */
}
-static void *ll_load (lua_State *L, const char *path, int seeglb) {
+static void *lsys_load (lua_State *L, const char *path, int seeglb) {
(void)(path); (void)(seeglb); /* not used */
lua_pushliteral(L, DLMSG);
return NULL;
}
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) {
(void)(lib); (void)(sym); /* not used */
lua_pushliteral(L, DLMSG);
return NULL;
@@ -248,7 +261,10 @@ static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
#endif
-static void *ll_checkclib (lua_State *L, const char *path) {
+/*
+** return registry.CLIBS[path]
+*/
+static void *checkclib (lua_State *L, const char *path) {
void *plib;
lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
lua_getfield(L, -1, path);
@@ -258,7 +274,11 @@ static void *ll_checkclib (lua_State *L, const char *path) {
}
-static void ll_addtoclib (lua_State *L, const char *path, void *plib) {
+/*
+** registry.CLIBS[path] = plib -- for queries
+** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
+*/
+static void addtoclib (lua_State *L, const char *path, void *plib) {
lua_getfield(L, LUA_REGISTRYINDEX, CLIBS);
lua_pushlightuserdata(L, plib);
lua_pushvalue(L, -1);
@@ -269,33 +289,49 @@ static void ll_addtoclib (lua_State *L, const char *path, void *plib) {
/*
-** __gc tag method for CLIBS table: calls 'll_unloadlib' for all lib
+** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib
** handles in list CLIBS
*/
static int gctm (lua_State *L) {
int n = luaL_len(L, 1);
for (; n >= 1; n--) { /* for each handle, in reverse order */
lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */
- ll_unloadlib(lua_touserdata(L, -1));
+ lsys_unloadlib(lua_touserdata(L, -1));
lua_pop(L, 1); /* pop handle */
}
return 0;
}
-static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
- void *reg = ll_checkclib(L, path); /* check loaded C libraries */
+
+/* error codes for 'lookforfunc' */
+#define ERRLIB 1
+#define ERRFUNC 2
+
+/*
+** Look for a C function named 'sym' in a dynamically loaded library
+** 'path'.
+** First, check whether the library is already loaded; if not, try
+** to load it.
+** Then, if 'sym' is '*', return true (as library has been loaded).
+** Otherwise, look for symbol 'sym' in the library and push a
+** C function with that symbol.
+** Return 0 and 'true' or a function in the stack; in case of
+** errors, return an error code and an error message in the stack.
+*/
+static int lookforfunc (lua_State *L, const char *path, const char *sym) {
+ void *reg = checkclib(L, path); /* check loaded C libraries */
if (reg == NULL) { /* must load library? */
- reg = ll_load(L, path, *sym == '*');
+ reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */
if (reg == NULL) return ERRLIB; /* unable to load library */
- ll_addtoclib(L, path, reg);
+ addtoclib(L, path, reg);
}
if (*sym == '*') { /* loading only library (no function)? */
lua_pushboolean(L, 1); /* return 'true' */
return 0; /* no errors */
}
else {
- lua_CFunction f = ll_sym(L, reg, sym);
+ lua_CFunction f = lsys_sym(L, reg, sym);
if (f == NULL)
return ERRFUNC; /* unable to find function */
lua_pushcfunction(L, f); /* else create new function */
@@ -307,7 +343,7 @@ static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
static int ll_loadlib (lua_State *L) {
const char *path = luaL_checkstring(L, 1);
const char *init = luaL_checkstring(L, 2);
- int stat = ll_loadfunc(L, path, init);
+ int stat = lookforfunc(L, path, init);
if (stat == 0) /* no errors? */
return 1; /* return the loaded function */
else { /* error; error message is on stack top */
@@ -416,21 +452,29 @@ static int searcher_Lua (lua_State *L) {
}
+/*
+** Try to find a load function for module 'modname' at file 'filename'.
+** First, change '.' to '_' in 'modname'; then, if 'modname' has
+** the form X-Y (that is, it has an "ignore mark"), build a function
+** name "luaopen_X" and look for it. (For compatibility, if that
+** fails, it also tries "luaopen_Y".) If there is no ignore mark,
+** look for a function named "luaopen_modname".
+*/
static int loadfunc (lua_State *L, const char *filename, const char *modname) {
- const char *funcname;
+ const char *openfunc;
const char *mark;
modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
mark = strchr(modname, *LUA_IGMARK);
if (mark) {
int stat;
- funcname = lua_pushlstring(L, modname, mark - modname);
- funcname = lua_pushfstring(L, LUA_POF"%s", funcname);
- stat = ll_loadfunc(L, filename, funcname);
+ openfunc = lua_pushlstring(L, modname, mark - modname);
+ openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc);
+ stat = lookforfunc(L, filename, openfunc);
if (stat != ERRFUNC) return stat;
modname = mark + 1; /* else go ahead and try old-style name */
}
- funcname = lua_pushfstring(L, LUA_POF"%s", modname);
- return ll_loadfunc(L, filename, funcname);
+ openfunc = lua_pushfstring(L, LUA_POF"%s", modname);
+ return lookforfunc(L, filename, openfunc);
}
@@ -686,24 +730,31 @@ static void createsearcherstable (lua_State *L) {
lua_pushcclosure(L, searchers[i], 1);
lua_rawseti(L, -2, i+1);
}
+#if defined(LUA_COMPAT_LOADERS)
+ lua_pushvalue(L, -1); /* make a copy of 'searchers' table */
+ lua_setfield(L, -3, "loaders"); /* put it in field `loaders' */
+#endif
+ lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
}
-LUAMOD_API int luaopen_package (lua_State *L) {
- /* create table CLIBS to keep track of loaded C libraries */
- luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS);
- lua_createtable(L, 0, 1); /* metatable for CLIBS */
+/*
+** create table CLIBS to keep track of loaded C libraries,
+** setting a finalizer to close all libraries when closing state.
+*/
+static void createclibstable (lua_State *L) {
+ luaL_getsubtable(L, LUA_REGISTRYINDEX, CLIBS); /* create CLIBS table */
+ lua_createtable(L, 0, 1); /* create metatable for CLIBS */
lua_pushcfunction(L, gctm);
lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */
lua_setmetatable(L, -2);
- /* create `package' table */
- luaL_newlib(L, pk_funcs);
+}
+
+
+LUAMOD_API int luaopen_package (lua_State *L) {
+ createclibstable(L);
+ luaL_newlib(L, pk_funcs); /* create `package' table */
createsearcherstable(L);
-#if defined(LUA_COMPAT_LOADERS)
- lua_pushvalue(L, -1); /* make a copy of 'searchers' table */
- lua_setfield(L, -3, "loaders"); /* put it in field `loaders' */
-#endif
- lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
/* set field 'path' */
setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT);
/* set field 'cpath' */
