source/libs/luajit/LuaJIT-src/src/lib_ffi.c

   1 /*
   2 ** FFI library.
   3 ** Copyright (C) 2005-2015 Mike Pall. See Copyright Notice in luajit.h
   4 */
   5
   6 #define lib_ffi_c
   7 #define LUA_LIB
   8
   9 #include <errno.h>
  10
  11 #include "lua.h"
  12 #include "lauxlib.h"
  13 #include "lualib.h"
  14
  15 #include "lj_obj.h"
  16
  17 #if LJ_HASFFI
  18
  19 #include "lj_gc.h"
  20 #include "lj_err.h"
  21 #include "lj_str.h"
  22 #include "lj_tab.h"
  23 #include "lj_meta.h"
  24 #include "lj_ctype.h"
  25 #include "lj_cparse.h"
  26 #include "lj_cdata.h"
  27 #include "lj_cconv.h"
  28 #include "lj_carith.h"
  29 #include "lj_ccall.h"
  30 #include "lj_ccallback.h"
  31 #include "lj_clib.h"
  32 #include "lj_strfmt.h"
  33 #include "lj_ff.h"
  34 #include "lj_lib.h"
  35
  36 /* -- C type checks ------------------------------------------------------- */
  37
  38 /* Check first argument for a C type and returns its ID. */
  39 static CTypeID ffi_checkctype(lua_State *L, CTState *cts, TValue *param)
  40 {
  41   TValue *o = L->base;
  42   if (!(o < L->top)) {
  43   err_argtype:
  44     lj_err_argtype(L, 1, "C type");
  45   }
  46   if (tvisstr(o)) {  /* Parse an abstract C type declaration. */
  47     GCstr *s = strV(o);
  48     CPState cp;
  49     int errcode;
  50     cp.L = L;
  51     cp.cts = cts;
  52     cp.srcname = strdata(s);
  53     cp.p = strdata(s);
  54     cp.param = param;
  55     cp.mode = CPARSE_MODE_ABSTRACT|CPARSE_MODE_NOIMPLICIT;
  56     errcode = lj_cparse(&cp);
  57     if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */
  58     return cp.val.id;
  59   } else {
  60     GCcdata *cd;
  61     if (!tviscdata(o)) goto err_argtype;
  62     if (param && param < L->top) lj_err_arg(L, 1, LJ_ERR_FFI_NUMPARAM);
  63     cd = cdataV(o);
  64     return cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) : cd->ctypeid;
  65   }
  66 }
  67
  68 /* Check argument for C data and return it. */
  69 static GCcdata *ffi_checkcdata(lua_State *L, int narg)
  70 {
  71   TValue *o = L->base + narg-1;
  72   if (!(o < L->top && tviscdata(o)))
  73     lj_err_argt(L, narg, LUA_TCDATA);
  74   return cdataV(o);
  75 }
  76
  77 /* Convert argument to C pointer. */
  78 static void *ffi_checkptr(lua_State *L, int narg, CTypeID id)
  79 {
  80   CTState *cts = ctype_cts(L);
  81   TValue *o = L->base + narg-1;
  82   void *p;
  83   if (o >= L->top)
  84     lj_err_arg(L, narg, LJ_ERR_NOVAL);
  85   lj_cconv_ct_tv(cts, ctype_get(cts, id), (uint8_t *)&p, o, CCF_ARG(narg));
  86   return p;
  87 }
  88
  89 /* Convert argument to int32_t. */
  90 static int32_t ffi_checkint(lua_State *L, int narg)
  91 {
  92   CTState *cts = ctype_cts(L);
  93   TValue *o = L->base + narg-1;
  94   int32_t i;
  95   if (o >= L->top)
  96     lj_err_arg(L, narg, LJ_ERR_NOVAL);
  97   lj_cconv_ct_tv(cts, ctype_get(cts, CTID_INT32), (uint8_t *)&i, o,
  98                  CCF_ARG(narg));
  99   return i;
 100 }
 101
 102 /* -- C type metamethods -------------------------------------------------- */
 103
 104 #define LJLIB_MODULE_ffi_meta
 105
 106 /* Handle ctype __index/__newindex metamethods. */
 107 static int ffi_index_meta(lua_State *L, CTState *cts, CType *ct, MMS mm)
 108 {
 109   CTypeID id = ctype_typeid(cts, ct);
 110   cTValue *tv = lj_ctype_meta(cts, id, mm);
 111   TValue *base = L->base;
 112   if (!tv) {
 113     const char *s;
 114   err_index:
 115     s = strdata(lj_ctype_repr(L, id, NULL));
 116     if (tvisstr(L->base+1)) {
 117       lj_err_callerv(L, LJ_ERR_FFI_BADMEMBER, s, strVdata(L->base+1));
 118     } else {
 119       const char *key = tviscdata(L->base+1) ?
 120         strdata(lj_ctype_repr(L, cdataV(L->base+1)->ctypeid, NULL)) :
 121         lj_typename(L->base+1);
 122       lj_err_callerv(L, LJ_ERR_FFI_BADIDXW, s, key);
 123     }
 124   }
 125   if (!tvisfunc(tv)) {
 126     if (mm == MM_index) {
 127       cTValue *o = lj_meta_tget(L, tv, base+1);
 128       if (o) {
 129         if (tvisnil(o)) goto err_index;
 130         copyTV(L, L->top-1, o);
 131         return 1;
 132       }
 133     } else {
 134       TValue *o = lj_meta_tset(L, tv, base+1);
 135       if (o) {
 136         copyTV(L, o, base+2);
 137         return 0;
 138       }
 139     }
 140     copyTV(L, base, L->top);
 141     tv = L->top-1-LJ_FR2;
 142   }
 143   return lj_meta_tailcall(L, tv);
 144 }
 145
 146 LJLIB_CF(ffi_meta___index)      LJLIB_REC(cdata_index 0)
 147 {
 148   CTState *cts = ctype_cts(L);
 149   CTInfo qual = 0;
 150   CType *ct;
 151   uint8_t *p;
 152   TValue *o = L->base;
 153   if (!(o+1 < L->top && tviscdata(o)))  /* Also checks for presence of key. */
 154     lj_err_argt(L, 1, LUA_TCDATA);
 155   ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
 156   if ((qual & 1))
 157     return ffi_index_meta(L, cts, ct, MM_index);
 158   if (lj_cdata_get(cts, ct, L->top-1, p))
 159     lj_gc_check(L);
 160   return 1;
 161 }
 162
 163 LJLIB_CF(ffi_meta___newindex)   LJLIB_REC(cdata_index 1)
 164 {
 165   CTState *cts = ctype_cts(L);
 166   CTInfo qual = 0;
 167   CType *ct;
 168   uint8_t *p;
 169   TValue *o = L->base;
 170   if (!(o+2 < L->top && tviscdata(o)))  /* Also checks for key and value. */
 171     lj_err_argt(L, 1, LUA_TCDATA);
 172   ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
 173   if ((qual & 1)) {
 174     if ((qual & CTF_CONST))
 175       lj_err_caller(L, LJ_ERR_FFI_WRCONST);
 176     return ffi_index_meta(L, cts, ct, MM_newindex);
 177   }
 178   lj_cdata_set(cts, ct, p, o+2, qual);
 179   return 0;
 180 }
 181
 182 /* Common handler for cdata arithmetic. */
 183 static int ffi_arith(lua_State *L)
 184 {
 185   MMS mm = (MMS)(curr_func(L)->c.ffid - (int)FF_ffi_meta___eq + (int)MM_eq);
 186   return lj_carith_op(L, mm);
 187 }
 188
 189 /* The following functions must be in contiguous ORDER MM. */
 190 LJLIB_CF(ffi_meta___eq)         LJLIB_REC(cdata_arith MM_eq)
 191 {
 192   return ffi_arith(L);
 193 }
 194
 195 LJLIB_CF(ffi_meta___len)        LJLIB_REC(cdata_arith MM_len)
 196 {
 197   return ffi_arith(L);
 198 }
 199
 200 LJLIB_CF(ffi_meta___lt)         LJLIB_REC(cdata_arith MM_lt)
 201 {
 202   return ffi_arith(L);
 203 }
 204
 205 LJLIB_CF(ffi_meta___le)         LJLIB_REC(cdata_arith MM_le)
 206 {
 207   return ffi_arith(L);
 208 }
 209
 210 LJLIB_CF(ffi_meta___concat)     LJLIB_REC(cdata_arith MM_concat)
 211 {
 212   return ffi_arith(L);
 213 }
 214
 215 /* Forward declaration. */
 216 static int lj_cf_ffi_new(lua_State *L);
 217
 218 LJLIB_CF(ffi_meta___call)       LJLIB_REC(cdata_call)
 219 {
 220   CTState *cts = ctype_cts(L);
 221   GCcdata *cd = ffi_checkcdata(L, 1);
 222   CTypeID id = cd->ctypeid;
 223   CType *ct;
 224   cTValue *tv;
 225   MMS mm = MM_call;
 226   if (cd->ctypeid == CTID_CTYPEID) {
 227     id = *(CTypeID *)cdataptr(cd);
 228     mm = MM_new;
 229   } else {
 230     int ret = lj_ccall_func(L, cd);
 231     if (ret >= 0)
 232       return ret;
 233   }
 234   /* Handle ctype __call/__new metamethod. */
 235   ct = ctype_raw(cts, id);
 236   if (ctype_isptr(ct->info)) id = ctype_cid(ct->info);
 237   tv = lj_ctype_meta(cts, id, mm);
 238   if (tv)
 239     return lj_meta_tailcall(L, tv);
 240   else if (mm == MM_call)
 241     lj_err_callerv(L, LJ_ERR_FFI_BADCALL, strdata(lj_ctype_repr(L, id, NULL)));
 242   return lj_cf_ffi_new(L);
 243 }
 244
 245 LJLIB_CF(ffi_meta___add)        LJLIB_REC(cdata_arith MM_add)
 246 {
 247   return ffi_arith(L);
 248 }
 249
 250 LJLIB_CF(ffi_meta___sub)        LJLIB_REC(cdata_arith MM_sub)
 251 {
 252   return ffi_arith(L);
 253 }
 254
 255 LJLIB_CF(ffi_meta___mul)        LJLIB_REC(cdata_arith MM_mul)
 256 {
 257   return ffi_arith(L);
 258 }
 259
 260 LJLIB_CF(ffi_meta___div)        LJLIB_REC(cdata_arith MM_div)
 261 {
 262   return ffi_arith(L);
 263 }
 264
 265 LJLIB_CF(ffi_meta___mod)        LJLIB_REC(cdata_arith MM_mod)
 266 {
 267   return ffi_arith(L);
 268 }
 269
 270 LJLIB_CF(ffi_meta___pow)        LJLIB_REC(cdata_arith MM_pow)
 271 {
 272   return ffi_arith(L);
 273 }
 274
 275 LJLIB_CF(ffi_meta___unm)        LJLIB_REC(cdata_arith MM_unm)
 276 {
 277   return ffi_arith(L);
 278 }
 279 /* End of contiguous ORDER MM. */
 280
 281 LJLIB_CF(ffi_meta___tostring)
 282 {
 283   GCcdata *cd = ffi_checkcdata(L, 1);
 284   const char *msg = "cdata<%s>: %p";
 285   CTypeID id = cd->ctypeid;
 286   void *p = cdataptr(cd);
 287   if (id == CTID_CTYPEID) {
 288     msg = "ctype<%s>";
 289     id = *(CTypeID *)p;
 290   } else {
 291     CTState *cts = ctype_cts(L);
 292     CType *ct = ctype_raw(cts, id);
 293     if (ctype_isref(ct->info)) {
 294       p = *(void **)p;
 295       ct = ctype_rawchild(cts, ct);
 296     }
 297     if (ctype_iscomplex(ct->info)) {
 298       setstrV(L, L->top-1, lj_ctype_repr_complex(L, cdataptr(cd), ct->size));
 299       goto checkgc;
 300     } else if (ct->size == 8 && ctype_isinteger(ct->info)) {
 301       setstrV(L, L->top-1, lj_ctype_repr_int64(L, *(uint64_t *)cdataptr(cd),
 302                                                (ct->info & CTF_UNSIGNED)));
 303       goto checkgc;
 304     } else if (ctype_isfunc(ct->info)) {
 305       p = *(void **)p;
 306     } else if (ctype_isenum(ct->info)) {
 307       msg = "cdata<%s>: %d";
 308       p = (void *)(uintptr_t)*(uint32_t **)p;
 309     } else {
 310       if (ctype_isptr(ct->info)) {
 311         p = cdata_getptr(p, ct->size);
 312         ct = ctype_rawchild(cts, ct);
 313       }
 314       if (ctype_isstruct(ct->info) || ctype_isvector(ct->info)) {
 315         /* Handle ctype __tostring metamethod. */
 316         cTValue *tv = lj_ctype_meta(cts, ctype_typeid(cts, ct), MM_tostring);
 317         if (tv)
 318           return lj_meta_tailcall(L, tv);
 319       }
 320     }
 321   }
 322   lj_strfmt_pushf(L, msg, strdata(lj_ctype_repr(L, id, NULL)), p);
 323 checkgc:
 324   lj_gc_check(L);
 325   return 1;
 326 }
 327
 328 static int ffi_pairs(lua_State *L, MMS mm)
 329 {
 330   CTState *cts = ctype_cts(L);
 331   CTypeID id = ffi_checkcdata(L, 1)->ctypeid;
 332   CType *ct = ctype_raw(cts, id);
 333   cTValue *tv;
 334   if (ctype_isptr(ct->info)) id = ctype_cid(ct->info);
 335   tv = lj_ctype_meta(cts, id, mm);
 336   if (!tv)
 337     lj_err_callerv(L, LJ_ERR_FFI_BADMM, strdata(lj_ctype_repr(L, id, NULL)),
 338                    strdata(mmname_str(G(L), mm)));
 339   return lj_meta_tailcall(L, tv);
 340 }
 341
 342 LJLIB_CF(ffi_meta___pairs)
 343 {
 344   return ffi_pairs(L, MM_pairs);
 345 }
 346
 347 LJLIB_CF(ffi_meta___ipairs)
 348 {
 349   return ffi_pairs(L, MM_ipairs);
 350 }
 351
 352 LJLIB_PUSH("ffi") LJLIB_SET(__metatable)
 353
 354 #include "lj_libdef.h"
 355
 356 /* -- C library metamethods ----------------------------------------------- */
 357
 358 #define LJLIB_MODULE_ffi_clib
 359
 360 /* Index C library by a name. */
 361 static TValue *ffi_clib_index(lua_State *L)
 362 {
 363   TValue *o = L->base;
 364   CLibrary *cl;
 365   if (!(o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB))
 366     lj_err_argt(L, 1, LUA_TUSERDATA);
 367   cl = (CLibrary *)uddata(udataV(o));
 368   if (!(o+1 < L->top && tvisstr(o+1)))
 369     lj_err_argt(L, 2, LUA_TSTRING);
 370   return lj_clib_index(L, cl, strV(o+1));
 371 }
 372
 373 LJLIB_CF(ffi_clib___index)      LJLIB_REC(clib_index 1)
 374 {
 375   TValue *tv = ffi_clib_index(L);
 376   if (tviscdata(tv)) {
 377     CTState *cts = ctype_cts(L);
 378     GCcdata *cd = cdataV(tv);
 379     CType *s = ctype_get(cts, cd->ctypeid);
 380     if (ctype_isextern(s->info)) {
 381       CTypeID sid = ctype_cid(s->info);
 382       void *sp = *(void **)cdataptr(cd);
 383       CType *ct = ctype_raw(cts, sid);
 384       if (lj_cconv_tv_ct(cts, ct, sid, L->top-1, sp))
 385         lj_gc_check(L);
 386       return 1;
 387     }
 388   }
 389   copyTV(L, L->top-1, tv);
 390   return 1;
 391 }
 392
 393 LJLIB_CF(ffi_clib___newindex)   LJLIB_REC(clib_index 0)
 394 {
 395   TValue *tv = ffi_clib_index(L);
 396   TValue *o = L->base+2;
 397   if (o < L->top && tviscdata(tv)) {
 398     CTState *cts = ctype_cts(L);
 399     GCcdata *cd = cdataV(tv);
 400     CType *d = ctype_get(cts, cd->ctypeid);
 401     if (ctype_isextern(d->info)) {
 402       CTInfo qual = 0;
 403       for (;;) {  /* Skip attributes and collect qualifiers. */
 404         d = ctype_child(cts, d);
 405         if (!ctype_isattrib(d->info)) break;
 406         if (ctype_attrib(d->info) == CTA_QUAL) qual |= d->size;
 407       }
 408       if (!((d->info|qual) & CTF_CONST)) {
 409         lj_cconv_ct_tv(cts, d, *(void **)cdataptr(cd), o, 0);
 410         return 0;
 411       }
 412     }
 413   }
 414   lj_err_caller(L, LJ_ERR_FFI_WRCONST);
 415   return 0;  /* unreachable */
 416 }
 417
 418 LJLIB_CF(ffi_clib___gc)
 419 {
 420   TValue *o = L->base;
 421   if (o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB)
 422     lj_clib_unload((CLibrary *)uddata(udataV(o)));
 423   return 0;
 424 }
 425
 426 #include "lj_libdef.h"
 427
 428 /* -- Callback function metamethods --------------------------------------- */
 429
 430 #define LJLIB_MODULE_ffi_callback
 431
 432 static int ffi_callback_set(lua_State *L, GCfunc *fn)
 433 {
 434   GCcdata *cd = ffi_checkcdata(L, 1);
 435   CTState *cts = ctype_cts(L);
 436   CType *ct = ctype_raw(cts, cd->ctypeid);
 437   if (ctype_isptr(ct->info) && (LJ_32 || ct->size == 8)) {
 438     MSize slot = lj_ccallback_ptr2slot(cts, *(void **)cdataptr(cd));
 439     if (slot < cts->cb.sizeid && cts->cb.cbid[slot] != 0) {
 440       GCtab *t = cts->miscmap;
 441       TValue *tv = lj_tab_setint(L, t, (int32_t)slot);
 442       if (fn) {
 443         setfuncV(L, tv, fn);
 444         lj_gc_anybarriert(L, t);
 445       } else {
 446         setnilV(tv);
 447         cts->cb.cbid[slot] = 0;
 448         cts->cb.topid = slot < cts->cb.topid ? slot : cts->cb.topid;
 449       }
 450       return 0;
 451     }
 452   }
 453   lj_err_caller(L, LJ_ERR_FFI_BADCBACK);
 454   return 0;
 455 }
 456
 457 LJLIB_CF(ffi_callback_free)
 458 {
 459   return ffi_callback_set(L, NULL);
 460 }
 461
 462 LJLIB_CF(ffi_callback_set)
 463 {
 464   GCfunc *fn = lj_lib_checkfunc(L, 2);
 465   return ffi_callback_set(L, fn);
 466 }
 467
 468 LJLIB_PUSH(top-1) LJLIB_SET(__index)
 469
 470 #include "lj_libdef.h"
 471
 472 /* -- FFI library functions ----------------------------------------------- */
 473
 474 #define LJLIB_MODULE_ffi
 475
 476 LJLIB_CF(ffi_cdef)
 477 {
 478   GCstr *s = lj_lib_checkstr(L, 1);
 479   CPState cp;
 480   int errcode;
 481   cp.L = L;
 482   cp.cts = ctype_cts(L);
 483   cp.srcname = strdata(s);
 484   cp.p = strdata(s);
 485   cp.param = L->base+1;
 486   cp.mode = CPARSE_MODE_MULTI|CPARSE_MODE_DIRECT;
 487   errcode = lj_cparse(&cp);
 488   if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */
 489   lj_gc_check(L);
 490   return 0;
 491 }
 492
 493 LJLIB_CF(ffi_new)       LJLIB_REC(.)
 494 {
 495   CTState *cts = ctype_cts(L);
 496   CTypeID id = ffi_checkctype(L, cts, NULL);
 497   CType *ct = ctype_raw(cts, id);
 498   CTSize sz;
 499   CTInfo info = lj_ctype_info(cts, id, &sz);
 500   TValue *o = L->base+1;
 501   GCcdata *cd;
 502   if ((info & CTF_VLA)) {
 503     o++;
 504     sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
 505   }
 506   if (sz == CTSIZE_INVALID)
 507     lj_err_arg(L, 1, LJ_ERR_FFI_INVSIZE);
 508   if (!(info & CTF_VLA) && ctype_align(info) <= CT_MEMALIGN)
 509     cd = lj_cdata_new(cts, id, sz);
 510   else
 511     cd = lj_cdata_newv(L, id, sz, ctype_align(info));
 512   setcdataV(L, o-1, cd);  /* Anchor the uninitialized cdata. */
 513   lj_cconv_ct_init(cts, ct, sz, cdataptr(cd),
 514                    o, (MSize)(L->top - o));  /* Initialize cdata. */
 515   if (ctype_isstruct(ct->info)) {
 516     /* Handle ctype __gc metamethod. Use the fast lookup here. */
 517     cTValue *tv = lj_tab_getinth(cts->miscmap, -(int32_t)id);
 518     if (tv && tvistab(tv) && (tv = lj_meta_fast(L, tabV(tv), MM_gc))) {
 519       GCtab *t = cts->finalizer;
 520       if (gcref(t->metatable)) {
 521         /* Add to finalizer table, if still enabled. */
 522         copyTV(L, lj_tab_set(L, t, o-1), tv);
 523         lj_gc_anybarriert(L, t);
 524         cd->marked |= LJ_GC_CDATA_FIN;
 525       }
 526     }
 527   }
 528   L->top = o;  /* Only return the cdata itself. */
 529   lj_gc_check(L);
 530   return 1;
 531 }
 532
 533 LJLIB_CF(ffi_cast)      LJLIB_REC(ffi_new)
 534 {
 535   CTState *cts = ctype_cts(L);
 536   CTypeID id = ffi_checkctype(L, cts, NULL);
 537   CType *d = ctype_raw(cts, id);
 538   TValue *o = lj_lib_checkany(L, 2);
 539   L->top = o+1;  /* Make sure this is the last item on the stack. */
 540   if (!(ctype_isnum(d->info) || ctype_isptr(d->info) || ctype_isenum(d->info)))
 541     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 542   if (!(tviscdata(o) && cdataV(o)->ctypeid == id)) {
 543     GCcdata *cd = lj_cdata_new(cts, id, d->size);
 544     lj_cconv_ct_tv(cts, d, cdataptr(cd), o, CCF_CAST);
 545     setcdataV(L, o, cd);
 546     lj_gc_check(L);
 547   }
 548   return 1;
 549 }
 550
 551 LJLIB_CF(ffi_typeof)    LJLIB_REC(.)
 552 {
 553   CTState *cts = ctype_cts(L);
 554   CTypeID id = ffi_checkctype(L, cts, L->base+1);
 555   GCcdata *cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
 556   *(CTypeID *)cdataptr(cd) = id;
 557   setcdataV(L, L->top-1, cd);
 558   lj_gc_check(L);
 559   return 1;
 560 }
 561
 562 /* Internal and unsupported API. */
 563 LJLIB_CF(ffi_typeinfo)
 564 {
 565   CTState *cts = ctype_cts(L);
 566   CTypeID id = (CTypeID)ffi_checkint(L, 1);
 567   if (id > 0 && id < cts->top) {
 568     CType *ct = ctype_get(cts, id);
 569     GCtab *t;
 570     lua_createtable(L, 0, 4);  /* Increment hash size if fields are added. */
 571     t = tabV(L->top-1);
 572     setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "info")), (int32_t)ct->info);
 573     if (ct->size != CTSIZE_INVALID)
 574       setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "size")), (int32_t)ct->size);
 575     if (ct->sib)
 576       setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "sib")), (int32_t)ct->sib);
 577     if (gcref(ct->name)) {
 578       GCstr *s = gco2str(gcref(ct->name));
 579       setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "name")), s);
 580     }
 581     lj_gc_check(L);
 582     return 1;
 583   }
 584   return 0;
 585 }
 586
 587 LJLIB_CF(ffi_istype)    LJLIB_REC(.)
 588 {
 589   CTState *cts = ctype_cts(L);
 590   CTypeID id1 = ffi_checkctype(L, cts, NULL);
 591   TValue *o = lj_lib_checkany(L, 2);
 592   int b = 0;
 593   if (tviscdata(o)) {
 594     GCcdata *cd = cdataV(o);
 595     CTypeID id2 = cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) :
 596                                                 cd->ctypeid;
 597     CType *ct1 = lj_ctype_rawref(cts, id1);
 598     CType *ct2 = lj_ctype_rawref(cts, id2);
 599     if (ct1 == ct2) {
 600       b = 1;
 601     } else if (ctype_type(ct1->info) == ctype_type(ct2->info) &&
 602                ct1->size == ct2->size) {
 603       if (ctype_ispointer(ct1->info))
 604         b = lj_cconv_compatptr(cts, ct1, ct2, CCF_IGNQUAL);
 605       else if (ctype_isnum(ct1->info) || ctype_isvoid(ct1->info))
 606         b = (((ct1->info ^ ct2->info) & ~(CTF_QUAL|CTF_LONG)) == 0);
 607     } else if (ctype_isstruct(ct1->info) && ctype_isptr(ct2->info) &&
 608                ct1 == ctype_rawchild(cts, ct2)) {
 609       b = 1;
 610     }
 611   }
 612   setboolV(L->top-1, b);
 613   setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
 614   return 1;
 615 }
 616
 617 LJLIB_CF(ffi_sizeof)    LJLIB_REC(ffi_xof FF_ffi_sizeof)
 618 {
 619   CTState *cts = ctype_cts(L);
 620   CTypeID id = ffi_checkctype(L, cts, NULL);
 621   CTSize sz;
 622   if (LJ_UNLIKELY(tviscdata(L->base) && cdataisv(cdataV(L->base)))) {
 623     sz = cdatavlen(cdataV(L->base));
 624   } else {
 625     CType *ct = lj_ctype_rawref(cts, id);
 626     if (ctype_isvltype(ct->info))
 627       sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
 628     else
 629       sz = ctype_hassize(ct->info) ? ct->size : CTSIZE_INVALID;
 630     if (LJ_UNLIKELY(sz == CTSIZE_INVALID)) {
 631       setnilV(L->top-1);
 632       return 1;
 633     }
 634   }
 635   setintV(L->top-1, (int32_t)sz);
 636   return 1;
 637 }
 638
 639 LJLIB_CF(ffi_alignof)   LJLIB_REC(ffi_xof FF_ffi_alignof)
 640 {
 641   CTState *cts = ctype_cts(L);
 642   CTypeID id = ffi_checkctype(L, cts, NULL);
 643   CTSize sz = 0;
 644   CTInfo info = lj_ctype_info(cts, id, &sz);
 645   setintV(L->top-1, 1 << ctype_align(info));
 646   return 1;
 647 }
 648
 649 LJLIB_CF(ffi_offsetof)  LJLIB_REC(ffi_xof FF_ffi_offsetof)
 650 {
 651   CTState *cts = ctype_cts(L);
 652   CTypeID id = ffi_checkctype(L, cts, NULL);
 653   GCstr *name = lj_lib_checkstr(L, 2);
 654   CType *ct = lj_ctype_rawref(cts, id);
 655   CTSize ofs;
 656   if (ctype_isstruct(ct->info) && ct->size != CTSIZE_INVALID) {
 657     CType *fct = lj_ctype_getfield(cts, ct, name, &ofs);
 658     if (fct) {
 659       setintV(L->top-1, ofs);
 660       if (ctype_isfield(fct->info)) {
 661         return 1;
 662       } else if (ctype_isbitfield(fct->info)) {
 663         setintV(L->top++, ctype_bitpos(fct->info));
 664         setintV(L->top++, ctype_bitbsz(fct->info));
 665         return 3;
 666       }
 667     }
 668   }
 669   return 0;
 670 }
 671
 672 LJLIB_CF(ffi_errno)     LJLIB_REC(.)
 673 {
 674   int err = errno;
 675   if (L->top > L->base)
 676     errno = ffi_checkint(L, 1);
 677   setintV(L->top++, err);
 678   return 1;
 679 }
 680
 681 LJLIB_CF(ffi_string)    LJLIB_REC(.)
 682 {
 683   CTState *cts = ctype_cts(L);
 684   TValue *o = lj_lib_checkany(L, 1);
 685   const char *p;
 686   size_t len;
 687   if (o+1 < L->top && !tvisnil(o+1)) {
 688     len = (size_t)ffi_checkint(L, 2);
 689     lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p, o,
 690                    CCF_ARG(1));
 691   } else {
 692     lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CCHAR), (uint8_t *)&p, o,
 693                    CCF_ARG(1));
 694     len = strlen(p);
 695   }
 696   L->top = o+1;  /* Make sure this is the last item on the stack. */
 697   setstrV(L, o, lj_str_new(L, p, len));
 698   lj_gc_check(L);
 699   return 1;
 700 }
 701
 702 LJLIB_CF(ffi_copy)      LJLIB_REC(.)
 703 {
 704   void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
 705   void *sp = ffi_checkptr(L, 2, CTID_P_CVOID);
 706   TValue *o = L->base+1;
 707   CTSize len;
 708   if (tvisstr(o) && o+1 >= L->top)
 709     len = strV(o)->len+1;  /* Copy Lua string including trailing '\0'. */
 710   else
 711     len = (CTSize)ffi_checkint(L, 3);
 712   memcpy(dp, sp, len);
 713   return 0;
 714 }
 715
 716 LJLIB_CF(ffi_fill)      LJLIB_REC(.)
 717 {
 718   void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
 719   CTSize len = (CTSize)ffi_checkint(L, 2);
 720   int32_t fill = 0;
 721   if (L->base+2 < L->top && !tvisnil(L->base+2)) fill = ffi_checkint(L, 3);
 722   memset(dp, fill, len);
 723   return 0;
 724 }
 725
 726 #define H_(le, be)      LJ_ENDIAN_SELECT(0x##le, 0x##be)
 727
 728 /* Test ABI string. */
 729 LJLIB_CF(ffi_abi)       LJLIB_REC(.)
 730 {
 731   GCstr *s = lj_lib_checkstr(L, 1);
 732   int b = 0;
 733   switch (s->hash) {
 734 #if LJ_64
 735   case H_(849858eb,ad35fd06): b = 1; break;  /* 64bit */
 736 #else
 737   case H_(662d3c79,d0e22477): b = 1; break;  /* 32bit */
 738 #endif
 739 #if LJ_ARCH_HASFPU
 740   case H_(e33ee463,e33ee463): b = 1; break;  /* fpu */
 741 #endif
 742 #if LJ_ABI_SOFTFP
 743   case H_(61211a23,c2e8c81c): b = 1; break;  /* softfp */
 744 #else
 745   case H_(539417a8,8ce0812f): b = 1; break;  /* hardfp */
 746 #endif
 747 #if LJ_ABI_EABI
 748   case H_(2182df8f,f2ed1152): b = 1; break;  /* eabi */
 749 #endif
 750 #if LJ_ABI_WIN
 751   case H_(4ab624a8,4ab624a8): b = 1; break;  /* win */
 752 #endif
 753   case H_(3af93066,1f001464): b = 1; break;  /* le/be */
 754 #if LJ_GC64
 755   case H_(9e89d2c9,13c83c92): b = 1; break;  /* gc64 */
 756 #endif
 757   default:
 758     break;
 759   }
 760   setboolV(L->top-1, b);
 761   setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
 762   return 1;
 763 }
 764
 765 #undef H_
 766
 767 LJLIB_PUSH(top-8) LJLIB_SET(!)  /* Store reference to miscmap table. */
 768
 769 LJLIB_CF(ffi_metatype)
 770 {
 771   CTState *cts = ctype_cts(L);
 772   CTypeID id = ffi_checkctype(L, cts, NULL);
 773   GCtab *mt = lj_lib_checktab(L, 2);
 774   GCtab *t = cts->miscmap;
 775   CType *ct = ctype_get(cts, id);  /* Only allow raw types. */
 776   TValue *tv;
 777   GCcdata *cd;
 778   if (!(ctype_isstruct(ct->info) || ctype_iscomplex(ct->info) ||
 779         ctype_isvector(ct->info)))
 780     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 781   tv = lj_tab_setinth(L, t, -(int32_t)id);
 782   if (!tvisnil(tv))
 783     lj_err_caller(L, LJ_ERR_PROTMT);
 784   settabV(L, tv, mt);
 785   lj_gc_anybarriert(L, t);
 786   cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
 787   *(CTypeID *)cdataptr(cd) = id;
 788   setcdataV(L, L->top-1, cd);
 789   lj_gc_check(L);
 790   return 1;
 791 }
 792
 793 LJLIB_PUSH(top-7) LJLIB_SET(!)  /* Store reference to finalizer table. */
 794
 795 LJLIB_CF(ffi_gc)        LJLIB_REC(.)
 796 {
 797   GCcdata *cd = ffi_checkcdata(L, 1);
 798   TValue *fin = lj_lib_checkany(L, 2);
 799   CTState *cts = ctype_cts(L);
 800   CType *ct = ctype_raw(cts, cd->ctypeid);
 801   if (!(ctype_isptr(ct->info) || ctype_isstruct(ct->info) ||
 802         ctype_isrefarray(ct->info)))
 803     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 804   lj_cdata_setfin(L, cd, gcval(fin), itype(fin));
 805   L->top = L->base+1;  /* Pass through the cdata object. */
 806   return 1;
 807 }
 808
 809 LJLIB_PUSH(top-5) LJLIB_SET(!)  /* Store clib metatable in func environment. */
 810
 811 LJLIB_CF(ffi_load)
 812 {
 813   GCstr *name = lj_lib_checkstr(L, 1);
 814   int global = (L->base+1 < L->top && tvistruecond(L->base+1));
 815   lj_clib_load(L, tabref(curr_func(L)->c.env), name, global);
 816   return 1;
 817 }
 818
 819 LJLIB_PUSH(top-4) LJLIB_SET(C)
 820 LJLIB_PUSH(top-3) LJLIB_SET(os)
 821 LJLIB_PUSH(top-2) LJLIB_SET(arch)
 822
 823 #include "lj_libdef.h"
 824
 825 /* ------------------------------------------------------------------------ */
 826
 827 /* Create special weak-keyed finalizer table. */
 828 static GCtab *ffi_finalizer(lua_State *L)
 829 {
 830   /* NOBARRIER: The table is new (marked white). */
 831   GCtab *t = lj_tab_new(L, 0, 1);
 832   settabV(L, L->top++, t);
 833   setgcref(t->metatable, obj2gco(t));
 834   setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "__mode")),
 835           lj_str_newlit(L, "K"));
 836   t->nomm = (uint8_t)(~(1u<<MM_mode));
 837   return t;
 838 }
 839
 840 /* Register FFI module as loaded. */
 841 static void ffi_register_module(lua_State *L)
 842 {
 843   cTValue *tmp = lj_tab_getstr(tabV(registry(L)), lj_str_newlit(L, "_LOADED"));
 844   if (tmp && tvistab(tmp)) {
 845     GCtab *t = tabV(tmp);
 846     copyTV(L, lj_tab_setstr(L, t, lj_str_newlit(L, LUA_FFILIBNAME)), L->top-1);
 847     lj_gc_anybarriert(L, t);
 848   }
 849 }
 850
 851 LUALIB_API int luaopen_ffi(lua_State *L)
 852 {
 853   CTState *cts = lj_ctype_init(L);
 854   settabV(L, L->top++, (cts->miscmap = lj_tab_new(L, 0, 1)));
 855   cts->finalizer = ffi_finalizer(L);
 856   LJ_LIB_REG(L, NULL, ffi_meta);
 857   /* NOBARRIER: basemt is a GC root. */
 858   setgcref(basemt_it(G(L), LJ_TCDATA), obj2gco(tabV(L->top-1)));
 859   LJ_LIB_REG(L, NULL, ffi_clib);
 860   LJ_LIB_REG(L, NULL, ffi_callback);
 861   /* NOBARRIER: the key is new and lj_tab_newkey() handles the barrier. */
 862   settabV(L, lj_tab_setstr(L, cts->miscmap, &cts->g->strempty), tabV(L->top-1));
 863   L->top--;
 864   lj_clib_default(L, tabV(L->top-1));  /* Create ffi.C default namespace. */
 865   lua_pushliteral(L, LJ_OS_NAME);
 866   lua_pushliteral(L, LJ_ARCH_NAME);
 867   LJ_LIB_REG(L, NULL, ffi);  /* Note: no global "ffi" created! */
 868   ffi_register_module(L);
 869   return 1;
 870 }
 871
 872 #endif