commit a5eb48a3e69871eb3ed7df5fc09ae6bfea75fbd3
parent 49fe79e9fd6db53703037e0c2e51d74fe6d27400
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 27 Dec 2004 13:57:53 -0200
redesigned loadlib (Windows version not tested yet)
Diffstat:
| M | loadlib.c | | | 324 | ++++++++++++++++++++++++++++++++++++++++++++----------------------------------- |
1 file changed, 182 insertions(+), 142 deletions(-)
diff --git a/loadlib.c b/loadlib.c
@@ -1,28 +1,11 @@
/*
-** $Id: loadlib.c,v 1.12 2004/12/13 12:14:21 roberto Exp roberto $
+** $Id: loadlib.c,v 1.13 2004/12/22 17:43:27 roberto Exp roberto $
** Dynamic library loader for Lua
** See Copyright Notice in lua.h
*
-* This Lua library exports a single function, called loadlib, which
-* is called from Lua as loadlib(lib,init), where lib is the full
-* name of the library to be loaded (including the complete path) and
-* init is the name of a function to be called after the library is
-* loaded. Typically, this function will register other functions, thus
-* making the complete library available to Lua. The init function is
-* *not* automatically called by loadlib. Instead, loadlib returns the
-* init function as a Lua function that the client can call when it
-* thinks is appropriate. In the case of errors, loadlib returns nil and
-* two strings describing the error. The first string is supplied by
-* the operating system; it should be informative and useful for error
-* messages. The second string is "open", "init", or "absent" to identify
-* the error and is meant to be used for making decisions without having
-* to look into the first string (whose format is system-dependent).
* This module contains an implementation of loadlib for Unix systems
* that have dlfcn, an implementation for Darwin (Mac OS X), an
-* implementation for Windows, and a stub for other systems. See
-* the list at the end of this file for some links to available
-* implementations of dlfcn and interfaces to other native dynamic
-* loaders on top of which loadlib could be implemented.
+* implementation for Windows, and a stub for other systems.
*/
@@ -38,96 +21,106 @@
#include "lualib.h"
-#define ERR_OPEN 1
-#define ERR_FUNCTION 2
-#define ERR_ABSENT 3
+#define LIBPREFIX "LOADLIB: "
+#define POF LUA_POF
+#define LIB_FAIL "open"
+
+
+static void ll_unloadlib (void *lib);
+static void *ll_load (lua_State *L, const char *path);
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
-static void registerlib (lua_State *L, const void *lib);
#if defined(USE_DLOPEN)
/*
-* This is an implementation of loadlib based on the dlfcn interface.
-* The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
-* NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
-* as an emulation layer on top of native functions.
+** {========================================================================
+** This is an implementation of loadlib based on the dlfcn interface.
+** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
+** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least
+** as an emulation layer on top of native functions.
+** =========================================================================
*/
#include <dlfcn.h>
-#define freelib dlclose
-
-static int loadlib(lua_State *L, const char *path, const char *init) {
- void *lib=dlopen(path,RTLD_NOW);
- if (lib != NULL) {
- lua_CFunction f=(lua_CFunction) dlsym(lib,init);
- if (f != NULL) {
- registerlib(L, lib);
- lua_pushcfunction(L,f);
- return 0;
- }
- }
- /* else return appropriate error message */
- lua_pushstring(L,dlerror());
- if (lib != NULL) {
- dlclose(lib);
- return ERR_FUNCTION; /* error loading function */
- }
- else return ERR_OPEN; /* error loading library */
+static void ll_unloadlib (void *lib) {
+ dlclose(lib);
+}
+
+
+static void *ll_load (lua_State *L, const char *path) {
+ void *lib = dlopen(path, RTLD_NOW);
+ if (lib == NULL) lua_pushstring(L, dlerror());
+ return lib;
}
+static lua_CFunction ll_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;
+}
+
+/* }====================================================== */
+
+
#elif defined(USE_DLL)
/*
-* This is an implementation of loadlib for Windows using native functions.
+** {======================================================================
+** This is an implementation of loadlib for Windows using native functions.
+** =======================================================================
*/
#include <windows.h>
-#define freelib(lib) FreeLibrary((HINSTANCE)lib)
-
-static void pusherror(lua_State *L) {
+static void pusherror (lua_State *L) {
int error = GetLastError();
char buffer[128];
if (FormatMessage(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
- 0, error, 0, buffer, sizeof(buffer), 0))
+ NULL, error, 0, buffer, sizeof(buffer), NULL))
lua_pushstring(L,buffer);
else
lua_pushfstring(L, "system error %d\n", error);
}
+static void ll_unloadlib (void *lib) {
+ FreeLibrary((HINSTANCE)lib);
+}
-static int loadlib (lua_State *L, const char *path, const char *init) {
+
+static void *ll_load (lua_State *L, const char *path) {
HINSTANCE lib = LoadLibrary(path);
- if (lib != NULL) {
- lua_CFunction f = (lua_CFunction)GetProcAddress(lib, init);
- if (f != NULL) {
- registerlib(L, lib);
- lua_pushcfunction(L, f);
- return 0;
- }
- }
- pusherror(L);
- if (lib != NULL) {
- FreeLibrary(lib);
- return ERR_OPEN;
- }
- else return ERR_FUNCTION;
+ if (lib == NULL) pusherror(L);
+ return lib;
}
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+ lua_CFunction f = (lua_CFunction)GetProcAddress((HINSTANCE)lib, sym);
+ if (f == NULL) pusherror(L);
+ return f;
+}
+
+/* }====================================================== */
+
+
-/* Native Mac OS X / Darwin Implementation */
#elif defined(USE_DYLD)
+/*
+** {======================================================================
+** Native Mac OS X / Darwin Implementation
+** =======================================================================
+*/
#include <mach-o/dyld.h>
-/* Mach cannot unload images (?) */
-#define freelib(lib) ((void)lib)
+#undef POF
+#define POF "_" LUA_POF
static void pusherror (lua_State *L) {
@@ -140,86 +133,155 @@ static void pusherror (lua_State *L) {
}
-static int loadlib (lua_State *L, const char *path, const char *init) {
- const struct mach_header *lib;
+static const char *errorfromcode (NSObjectFileImageReturnCode ret) {
+ switch (ret) {
+ case NSObjectFileImageInappropriateFile:
+ return "file is not a bundle";
+ case NSObjectFileImageArch:
+ return "library is for wrong CPU type";
+ case NSObjectFileImageFormat:
+ return "bad format";
+ case NSObjectFileImageAccess:
+ return "cannot access file";
+ case NSObjectFileImageFailure:
+ default:
+ return "unable to load library";
+ }
+}
+
+
+static void ll_unloadlib (void *lib) {
+ NSUnLinkModule((NSModule)lib, NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES);
+}
+
+
+static void *ll_load (lua_State *L, const char *path) {
+ NSObjectFileImage img;
+ NSObjectFileImageReturnCode ret;
/* this would be a rare case, but prevents crashing if it happens */
if(!_dyld_present()) {
- lua_pushstring(L, "dyld not present.");
- return ERR_OPEN;
+ lua_pushliteral(L, "dyld not present");
+ return NULL;
}
- lib = NSAddImage(path, NSADDIMAGE_OPTION_RETURN_ON_ERROR);
- if(lib != NULL) {
- NSSymbol init_sym = NSLookupSymbolInImage(lib, init,
- NSLOOKUPSYMBOLINIMAGE_OPTION_BIND |
- NSLOOKUPSYMBOLINIMAGE_OPTION_RETURN_ON_ERROR);
- if(init_sym != NULL) {
- lua_CFunction f = (lua_CFunction)NSAddressOfSymbol(init_sym);
- registerlib(L, lib);
- lua_pushcfunction(L, f);
- return 0;
- }
+ ret = NSCreateObjectFileImageFromFile(path, &img);
+ if (ret == NSObjectFileImageSuccess) {
+ NSModule mod = NSLinkModule(img, path, NSLINKMODULE_OPTION_PRIVATE |
+ NSLINKMODULE_OPTION_RETURN_ON_ERROR);
+ NSDestroyObjectFileImage(img);
+ if (mod == NULL) pusherror(L);
+ return mod;
+ }
+ lua_pushstring(L, errorfromcode(ret));
+ return NULL;
+}
+
+
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+ NSSymbol nss = NSLookupSymbolInModule((NSModule)lib, sym);
+ if (nss == NULL) {
+ lua_pushfstring(L, "symbol `%s' not found", sym);
+ return NULL;
}
- /* else an error ocurred */
- pusherror(L);
- /* Can't unload image */
- return (lib != NULL) ? ERR_FUNCTION : ERR_OPEN;
+ return (lua_CFunction)NSAddressOfSymbol(nss);
}
+/* }====================================================== */
+
#else
-/* Fallback for other systems */
+/*
+** {======================================================
+** Fallback for other systems
+** =======================================================
+*/
+#undef LIB_FAIL
+#define LIB_FAIL "absent"
-#define freelib(lib) ((void)lib)
-static int loadlib (lua_State *L, const char *path, const char *init) {
- (void)path; (void)init; (void)®isterlib; /* to avoid warnings */
+static void ll_unloadlib (void *lib) {
+ (void)lib; /* to avoid warnings */
+}
+
+
+static void *ll_load (lua_State *L, const char *path) {
+ (void)path; /* to avoid warnings */
+ lua_pushliteral(L,"`loadlib' not supported");
+ return NULL;
+}
+
+
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+ (void)lib; (void)sym; /* to avoid warnings */
lua_pushliteral(L,"`loadlib' not supported");
- return ERR_ABSENT;
+ return NULL;
}
+/* }====================================================== */
#endif
-/*
-** common code for all implementations: put a library into the registry
-** so that, when Lua closes its state, the library's __gc metamethod
-** will be called to unload the library.
-*/
-static void registerlib (lua_State *L, const void *lib) {
- const void **plib = (const void **)lua_newuserdata(L, sizeof(const void *));
- *plib = lib;
- luaL_getmetatable(L, "_LOADLIB");
- lua_setmetatable(L, -2);
- lua_pushboolean(L, 1);
- lua_settable(L, LUA_REGISTRYINDEX); /* registry[lib] = true */
+
+static void **ll_register (lua_State *L, const char *path) {
+ void **plib;
+ lua_pushfstring(L, "%s%s", LIBPREFIX, path);
+ lua_gettable(L, LUA_REGISTRYINDEX); /* check library in registry? */
+ if (!lua_isnil(L, -1)) /* is there an entry? */
+ plib = (void **)lua_touserdata(L, -1);
+ else { /* no entry yet; create one */
+ lua_pop(L, 1);
+ plib = (void **)lua_newuserdata(L, sizeof(const void *));
+ *plib = NULL;
+ luaL_getmetatable(L, "_LOADLIB");
+ lua_setmetatable(L, -2);
+ lua_pushfstring(L, "%s%s", LIBPREFIX, path);
+ lua_pushvalue(L, -2);
+ lua_settable(L, LUA_REGISTRYINDEX);
+ }
+ return plib;
}
+
/*
-** __gc tag method: calls library's `freelib' function with the lib
+** __gc tag method: calls library's `ll_unloadlib' function with the lib
** handle
*/
static int gctm (lua_State *L) {
- void *lib = *(void **)luaL_checkudata(L, 1, "_LOADLIB");
- freelib(lib);
+ void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
+ if (lib) {
+ if (*lib) ll_unloadlib(*lib);
+ *lib = NULL; /* mark library as closed */
+ }
return 0;
}
+static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
+ const char *reason;
+ void **reg = ll_register(L, path);
+ if (*reg == NULL) *reg = ll_load(L, path);
+ if (*reg == NULL)
+ reason = LIB_FAIL;
+ else {
+ lua_CFunction f = ll_sym(L, *reg, sym);
+ if (f) {
+ lua_pushcfunction(L, f);
+ return 1; /* return function */
+ }
+ reason = "init";
+ }
+ lua_pushnil(L);
+ lua_insert(L, -2);
+ lua_pushstring(L, reason);
+ return 3; /* return nil, ll_error, reason */
+}
+
+
static int ll_loadlib (lua_State *L) {
- static const char *const errcodes[] = {NULL, "open", "init", "absent"};
const char *path = luaL_checkstring(L, 1);
const char *init = luaL_checkstring(L, 2);
- int res = loadlib(L,path,init);
- if (res == 0) /* no error? */
- return 1; /* function is at stack top */
- else { /* error */
- lua_pushnil(L);
- lua_insert(L, -2); /* insert nil before error message */
- lua_pushstring(L, errcodes[res]);
- return 3;
- }
+ return ll_loadfunc(L, path, init);
}
@@ -261,8 +323,8 @@ static const char *loadC (lua_State *L, const char *fname, const char *name) {
fname = luaL_searchpath(L, fname, path);
if (fname == NULL) return path; /* library not found in this path */
funcname = luaL_gsub(L, name, ".", LUA_OFSEP);
- funcname = lua_pushfstring(L, "%s%s", LUA_POF, funcname);
- if (loadlib(L, fname, funcname) != 0)
+ funcname = lua_pushfstring(L, "%s%s", POF, funcname);
+ if (ll_loadfunc(L, fname, funcname) != 1)
luaL_error(L, "error loading package `%s' (%s)", name, lua_tostring(L, -1));
return NULL; /* library loaded successfully */
}
@@ -400,25 +462,3 @@ LUALIB_API int luaopen_loadlib (lua_State *L) {
return 1;
}
-/*
-* Here are some links to available implementations of dlfcn and
-* interfaces to other native dynamic loaders on top of which loadlib
-* could be implemented. Please send contributions and corrections to us.
-*
-* AIX
-* Starting with AIX 4.2, dlfcn is included in the base OS.
-* There is also an emulation package available.
-* http://www.faqs.org/faqs/aix-faq/part4/section-21.html
-*
-* HPUX
-* HPUX 11 has dlfcn. For HPUX 10 use shl_*.
-* http://www.geda.seul.org/mailinglist/geda-dev37/msg00094.html
-* http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html
-*
-* Macintosh, Windows
-* http://www.stat.umn.edu/~luke/xls/projects/dlbasics/dlbasics.html
-*
-* GLIB has wrapper code for BeOS, OS2, Unix and Windows
-* http://cvs.gnome.org/lxr/source/glib/gmodule/
-*
-*/
