src/lj_clib.c

   1 /*
   2 ** FFI C library loader.
   3 ** Copyright (C) 2005-2012 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #include "lj_obj.h"
   7
   8 #if LJ_HASFFI
   9
  10 #include "lj_gc.h"
  11 #include "lj_err.h"
  12 #include "lj_tab.h"
  13 #include "lj_str.h"
  14 #include "lj_udata.h"
  15 #include "lj_ctype.h"
  16 #include "lj_cconv.h"
  17 #include "lj_cdata.h"
  18 #include "lj_clib.h"
  19
  20 /* -- OS-specific functions ----------------------------------------------- */
  21
  22 #if LJ_TARGET_DLOPEN
  23
  24 #include <dlfcn.h>
  25 #include <stdio.h>
  26
  27 #if defined(RTLD_DEFAULT)
  28 #define CLIB_DEFHANDLE  RTLD_DEFAULT
  29 #elif LJ_TARGET_OSX || LJ_TARGET_BSD
  30 #define CLIB_DEFHANDLE  ((void *)(intptr_t)-2)
  31 #else
  32 #define CLIB_DEFHANDLE  NULL
  33 #endif
  34
  35 LJ_NORET LJ_NOINLINE static void clib_error_(lua_State *L)
  36 {
  37   lj_err_callermsg(L, dlerror());
  38 }
  39
  40 #define clib_error(L, fmt, name)        clib_error_(L)
  41
  42 #if defined(__CYGWIN__)
  43 #define CLIB_SOPREFIX   "cyg"
  44 #else
  45 #define CLIB_SOPREFIX   "lib"
  46 #endif
  47
  48 #if LJ_TARGET_OSX
  49 #define CLIB_SOEXT      "%s.dylib"
  50 #elif defined(__CYGWIN__)
  51 #define CLIB_SOEXT      "%s.dll"
  52 #else
  53 #define CLIB_SOEXT      "%s.so"
  54 #endif
  55
  56 static const char *clib_extname(lua_State *L, const char *name)
  57 {
  58   if (!strchr(name, '/')
  59 #ifdef __CYGWIN__
  60       && !strchr(name, '\\')
  61 #endif
  62      ) {
  63     if (!strchr(name, '.')) {
  64       name = lj_str_pushf(L, CLIB_SOEXT, name);
  65       L->top--;
  66 #ifdef __CYGWIN__
  67     } else {
  68       return name;
  69 #endif
  70     }
  71     if (!(name[0] == CLIB_SOPREFIX[0] && name[1] == CLIB_SOPREFIX[1] &&
  72           name[2] == CLIB_SOPREFIX[2])) {
  73       name = lj_str_pushf(L, CLIB_SOPREFIX "%s", name);
  74       L->top--;
  75     }
  76   }
  77   return name;
  78 }
  79
  80 /* Check for a recognized ld script line. */
  81 static const char *clib_check_lds(lua_State *L, const char *buf)
  82 {
  83   char *p, *e;
  84   if ((!strncmp(buf, "GROUP", 5) || !strncmp(buf, "INPUT", 5)) &&
  85       (p = strchr(buf, '('))) {
  86     while (*++p == ' ') ;
  87     for (e = p; *e && *e != ' ' && *e != ')'; e++) ;
  88     return strdata(lj_str_new(L, p, e-p));
  89   }
  90   return NULL;
  91 }
  92
  93 /* Quick and dirty solution to resolve shared library name from ld script. */
  94 static const char *clib_resolve_lds(lua_State *L, const char *name)
  95 {
  96   FILE *fp = fopen(name, "r");
  97   const char *p = NULL;
  98   if (fp) {
  99     char buf[256];
 100     if (fgets(buf, sizeof(buf), fp)) {
 101       if (!strncmp(buf, "/* GNU ld script", 16)) {  /* ld script magic? */
 102         while (fgets(buf, sizeof(buf), fp)) {  /* Check all lines. */
 103           p = clib_check_lds(L, buf);
 104           if (p) break;
 105         }
 106       } else {  /* Otherwise check only the first line. */
 107         p = clib_check_lds(L, buf);
 108       }
 109     }
 110     fclose(fp);
 111   }
 112   return p;
 113 }
 114
 115 static void *clib_loadlib(lua_State *L, const char *name, int global)
 116 {
 117   void *h = dlopen(clib_extname(L, name),
 118                    RTLD_LAZY | (global?RTLD_GLOBAL:RTLD_LOCAL));
 119   if (!h) {
 120     const char *e, *err = dlerror();
 121     if (*err == '/' && (e = strchr(err, ':')) &&
 122         (name = clib_resolve_lds(L, strdata(lj_str_new(L, err, e-err))))) {
 123       h = dlopen(name, RTLD_LAZY | (global?RTLD_GLOBAL:RTLD_LOCAL));
 124       if (h) return h;
 125       err = dlerror();
 126     }
 127     lj_err_callermsg(L, err);
 128   }
 129   return h;
 130 }
 131
 132 static void clib_unloadlib(CLibrary *cl)
 133 {
 134   if (cl->handle && cl->handle != CLIB_DEFHANDLE)
 135     dlclose(cl->handle);
 136 }
 137
 138 static void *clib_getsym(CLibrary *cl, const char *name)
 139 {
 140   void *p = dlsym(cl->handle, name);
 141   return p;
 142 }
 143
 144 #elif LJ_TARGET_WINDOWS
 145
 146 #define WIN32_LEAN_AND_MEAN
 147 #ifndef WINVER
 148 #define WINVER 0x0500
 149 #endif
 150 #include <windows.h>
 151
 152 #ifndef GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS
 153 #define GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS  4
 154 #define GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT    2
 155 BOOL WINAPI GetModuleHandleExA(DWORD, LPCSTR, HMODULE*);
 156 #endif
 157
 158 #define CLIB_DEFHANDLE  ((void *)-1)
 159
 160 /* Default libraries. */
 161 enum {
 162   CLIB_HANDLE_EXE,
 163   CLIB_HANDLE_DLL,
 164   CLIB_HANDLE_CRT,
 165   CLIB_HANDLE_KERNEL32,
 166   CLIB_HANDLE_USER32,
 167   CLIB_HANDLE_GDI32,
 168   CLIB_HANDLE_MAX
 169 };
 170
 171 static void *clib_def_handle[CLIB_HANDLE_MAX];
 172
 173 LJ_NORET LJ_NOINLINE static void clib_error(lua_State *L, const char *fmt,
 174                                             const char *name)
 175 {
 176   DWORD err = GetLastError();
 177   char buf[128];
 178   if (!FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS|FORMAT_MESSAGE_FROM_SYSTEM,
 179                       NULL, err, 0, buf, sizeof(buf), NULL))
 180     buf[0] = '\0';
 181   lj_err_callermsg(L, lj_str_pushf(L, fmt, name, buf));
 182 }
 183
 184 static int clib_needext(const char *s)
 185 {
 186   while (*s) {
 187     if (*s == '/' || *s == '\\' || *s == '.') return 0;
 188     s++;
 189   }
 190   return 1;
 191 }
 192
 193 static const char *clib_extname(lua_State *L, const char *name)
 194 {
 195   if (clib_needext(name)) {
 196     name = lj_str_pushf(L, "%s.dll", name);
 197     L->top--;
 198   }
 199   return name;
 200 }
 201
 202 static void *clib_loadlib(lua_State *L, const char *name, int global)
 203 {
 204   DWORD oldwerr = GetLastError();
 205   void *h = (void *)LoadLibraryA(clib_extname(L, name));
 206   if (!h) clib_error(L, "cannot load module " LUA_QS ": %s", name);
 207   SetLastError(oldwerr);
 208   UNUSED(global);
 209   return h;
 210 }
 211
 212 static void clib_unloadlib(CLibrary *cl)
 213 {
 214   if (cl->handle == CLIB_DEFHANDLE) {
 215     MSize i;
 216     for (i = 0; i < CLIB_HANDLE_MAX; i++) {
 217       void *h = clib_def_handle[i];
 218       if (h) {
 219         clib_def_handle[i] = NULL;
 220         FreeLibrary((HINSTANCE)h);
 221       }
 222     }
 223   } else if (!cl->handle) {
 224     FreeLibrary((HINSTANCE)cl->handle);
 225   }
 226 }
 227
 228 static void *clib_getsym(CLibrary *cl, const char *name)
 229 {
 230   void *p = NULL;
 231   DWORD oldwerr = GetLastError();
 232   if (cl->handle == CLIB_DEFHANDLE) {  /* Search default libraries. */
 233     MSize i;
 234     for (i = 0; i < CLIB_HANDLE_MAX; i++) {
 235       HINSTANCE h = (HINSTANCE)clib_def_handle[i];
 236       if (!(void *)h) {  /* Resolve default library handles (once). */
 237         switch (i) {
 238         case CLIB_HANDLE_EXE: GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, NULL, &h); break;
 239         case CLIB_HANDLE_DLL:
 240           GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS|GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
 241                              (const char *)clib_def_handle, &h);
 242           break;
 243         case CLIB_HANDLE_CRT:
 244           GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS|GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
 245                              (const char *)&_fmode, &h);
 246           break;
 247         case CLIB_HANDLE_KERNEL32: h = LoadLibraryA("kernel32.dll"); break;
 248         case CLIB_HANDLE_USER32: h = LoadLibraryA("user32.dll"); break;
 249         case CLIB_HANDLE_GDI32: h = LoadLibraryA("gdi32.dll"); break;
 250         }
 251         if (!h) continue;
 252         clib_def_handle[i] = (void *)h;
 253       }
 254       p = (void *)GetProcAddress(h, name);
 255       if (p) break;
 256     }
 257   } else {
 258     p = (void *)GetProcAddress((HINSTANCE)cl->handle, name);
 259   }
 260   SetLastError(oldwerr);
 261   return p;
 262 }
 263
 264 #else
 265
 266 #define CLIB_DEFHANDLE  NULL
 267
 268 LJ_NORET LJ_NOINLINE static void clib_error(lua_State *L, const char *fmt,
 269                                             const char *name)
 270 {
 271   lj_err_callermsg(L, lj_str_pushf(L, fmt, name, "no support for this OS"));
 272 }
 273
 274 static void *clib_loadlib(lua_State *L, const char *name, int global)
 275 {
 276   lj_err_callermsg(L, "no support for loading dynamic libraries for this OS");
 277   UNUSED(name); UNUSED(global);
 278   return NULL;
 279 }
 280
 281 static void clib_unloadlib(CLibrary *cl)
 282 {
 283   UNUSED(cl);
 284 }
 285
 286 static void *clib_getsym(CLibrary *cl, const char *name)
 287 {
 288   UNUSED(cl); UNUSED(name);
 289   return NULL;
 290 }
 291
 292 #endif
 293
 294 /* -- C library indexing -------------------------------------------------- */
 295
 296 #if LJ_TARGET_X86 && LJ_ABI_WIN
 297 /* Compute argument size for fastcall/stdcall functions. */
 298 static CTSize clib_func_argsize(CTState *cts, CType *ct)
 299 {
 300   CTSize n = 0;
 301   while (ct->sib) {
 302     CType *d;
 303     ct = ctype_get(cts, ct->sib);
 304     if (ctype_isfield(ct->info)) {
 305       d = ctype_rawchild(cts, ct);
 306       n += ((d->size + 3) & ~3);
 307     }
 308   }
 309   return n;
 310 }
 311 #endif
 312
 313 /* Get redirected or mangled external symbol. */
 314 static const char *clib_extsym(CTState *cts, CType *ct, GCstr *name)
 315 {
 316   if (ct->sib) {
 317     CType *ctf = ctype_get(cts, ct->sib);
 318     if (ctype_isxattrib(ctf->info, CTA_REDIR))
 319       return strdata(gco2str(gcref(ctf->name)));
 320   }
 321   return strdata(name);
 322 }
 323
 324 /* Index a C library by name. */
 325 TValue *lj_clib_index(lua_State *L, CLibrary *cl, GCstr *name)
 326 {
 327   TValue *tv = lj_tab_setstr(L, cl->cache, name);
 328   if (LJ_UNLIKELY(tvisnil(tv))) {
 329     CTState *cts = ctype_cts(L);
 330     CType *ct;
 331     CTypeID id = lj_ctype_getname(cts, &ct, name, CLNS_INDEX);
 332     if (!id)
 333       lj_err_callerv(L, LJ_ERR_FFI_NODECL, strdata(name));
 334     if (ctype_isconstval(ct->info)) {
 335       CType *ctt = ctype_child(cts, ct);
 336       lua_assert(ctype_isinteger(ctt->info) && ctt->size <= 4);
 337       if ((ctt->info & CTF_UNSIGNED) && (int32_t)ct->size < 0)
 338         setnumV(tv, (lua_Number)(uint32_t)ct->size);
 339       else
 340         setintV(tv, (int32_t)ct->size);
 341     } else {
 342       const char *sym = clib_extsym(cts, ct, name);
 343       void *p = clib_getsym(cl, sym);
 344       GCcdata *cd;
 345       lua_assert(ctype_isfunc(ct->info) || ctype_isextern(ct->info));
 346 #if LJ_TARGET_X86 && LJ_ABI_WIN
 347       /* Retry with decorated name for fastcall/stdcall functions. */
 348       if (!p && ctype_isfunc(ct->info)) {
 349         CTInfo cconv = ctype_cconv(ct->info);
 350         if (cconv == CTCC_FASTCALL || cconv == CTCC_STDCALL) {
 351           CTSize sz = clib_func_argsize(cts, ct);
 352           sym = lj_str_pushf(L, cconv == CTCC_FASTCALL ? "@%s@%d" : "_%s@%d",
 353                              sym, sz);
 354           L->top--;
 355           p = clib_getsym(cl, sym);
 356         }
 357       }
 358 #endif
 359       if (!p)
 360         clib_error(L, "cannot resolve symbol " LUA_QS ": %s", strdata(name));
 361       cd = lj_cdata_new(cts, id, CTSIZE_PTR);
 362       *(void **)cdataptr(cd) = p;
 363       setcdataV(L, tv, cd);
 364     }
 365   }
 366   return tv;
 367 }
 368
 369 /* -- C library management ------------------------------------------------ */
 370
 371 /* Create a new CLibrary object and push it on the stack. */
 372 static CLibrary *clib_new(lua_State *L, GCtab *mt)
 373 {
 374   GCtab *t = lj_tab_new(L, 0, 0);
 375   GCudata *ud = lj_udata_new(L, sizeof(CLibrary), t);
 376   CLibrary *cl = (CLibrary *)uddata(ud);
 377   cl->cache = t;
 378   ud->udtype = UDTYPE_FFI_CLIB;
 379   /* NOBARRIER: The GCudata is new (marked white). */
 380   setgcref(ud->metatable, obj2gco(mt));
 381   setudataV(L, L->top++, ud);
 382   return cl;
 383 }
 384
 385 /* Load a C library. */
 386 void lj_clib_load(lua_State *L, GCtab *mt, GCstr *name, int global)
 387 {
 388   void *handle = clib_loadlib(L, strdata(name), global);
 389   CLibrary *cl = clib_new(L, mt);
 390   cl->handle = handle;
 391 }
 392
 393 /* Unload a C library. */
 394 void lj_clib_unload(CLibrary *cl)
 395 {
 396   clib_unloadlib(cl);
 397   cl->handle = NULL;
 398 }
 399
 400 /* Create the default C library object. */
 401 void lj_clib_default(lua_State *L, GCtab *mt)
 402 {
 403   CLibrary *cl = clib_new(L, mt);
 404   cl->handle = CLIB_DEFHANDLE;
 405 }
 406
 407 #endif