src/lib_ffi.c

   1 /*
   2 ** FFI library.
   3 ** Copyright (C) 2005-2023 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   cd = lj_cdata_newx(cts, id, sz, info);
 509   setcdataV(L, o-1, cd);  /* Anchor the uninitialized cdata. */
 510   lj_cconv_ct_init(cts, ct, sz, cdataptr(cd),
 511                    o, (MSize)(L->top - o));  /* Initialize cdata. */
 512   if (ctype_isstruct(ct->info)) {
 513     /* Handle ctype __gc metamethod. Use the fast lookup here. */
 514     cTValue *tv = lj_tab_getinth(cts->miscmap, -(int32_t)id);
 515     if (tv && tvistab(tv) && (tv = lj_meta_fast(L, tabV(tv), MM_gc))) {
 516       GCtab *t = tabref(G(L)->gcroot[GCROOT_FFI_FIN]);
 517       if (gcref(t->metatable)) {
 518         /* Add to finalizer table, if still enabled. */
 519         copyTV(L, lj_tab_set(L, t, o-1), tv);
 520         lj_gc_anybarriert(L, t);
 521         cd->marked |= LJ_GC_CDATA_FIN;
 522       }
 523     }
 524   }
 525   L->top = o;  /* Only return the cdata itself. */
 526   lj_gc_check(L);
 527   return 1;
 528 }
 529
 530 LJLIB_CF(ffi_cast)      LJLIB_REC(ffi_new)
 531 {
 532   CTState *cts = ctype_cts(L);
 533   CTypeID id = ffi_checkctype(L, cts, NULL);
 534   CType *d = ctype_raw(cts, id);
 535   TValue *o = lj_lib_checkany(L, 2);
 536   L->top = o+1;  /* Make sure this is the last item on the stack. */
 537   if (!(ctype_isnum(d->info) || ctype_isptr(d->info) || ctype_isenum(d->info)))
 538     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 539   if (!(tviscdata(o) && cdataV(o)->ctypeid == id)) {
 540     GCcdata *cd = lj_cdata_new(cts, id, d->size);
 541     lj_cconv_ct_tv(cts, d, cdataptr(cd), o, CCF_CAST);
 542     setcdataV(L, o, cd);
 543     lj_gc_check(L);
 544   }
 545   return 1;
 546 }
 547
 548 LJLIB_CF(ffi_typeof)    LJLIB_REC(.)
 549 {
 550   CTState *cts = ctype_cts(L);
 551   CTypeID id = ffi_checkctype(L, cts, L->base+1);
 552   GCcdata *cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
 553   *(CTypeID *)cdataptr(cd) = id;
 554   setcdataV(L, L->top-1, cd);
 555   lj_gc_check(L);
 556   return 1;
 557 }
 558
 559 /* Internal and unsupported API. */
 560 LJLIB_CF(ffi_typeinfo)
 561 {
 562   CTState *cts = ctype_cts(L);
 563   CTypeID id = (CTypeID)ffi_checkint(L, 1);
 564   if (id > 0 && id < cts->top) {
 565     CType *ct = ctype_get(cts, id);
 566     GCtab *t;
 567     lua_createtable(L, 0, 4);  /* Increment hash size if fields are added. */
 568     t = tabV(L->top-1);
 569     setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "info")), (int32_t)ct->info);
 570     if (ct->size != CTSIZE_INVALID)
 571       setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "size")), (int32_t)ct->size);
 572     if (ct->sib)
 573       setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "sib")), (int32_t)ct->sib);
 574     if (gcref(ct->name)) {
 575       GCstr *s = gco2str(gcref(ct->name));
 576       if (isdead(G(L), obj2gco(s))) flipwhite(obj2gco(s));
 577       setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "name")), s);
 578     }
 579     lj_gc_check(L);
 580     return 1;
 581   }
 582   return 0;
 583 }
 584
 585 LJLIB_CF(ffi_istype)    LJLIB_REC(.)
 586 {
 587   CTState *cts = ctype_cts(L);
 588   CTypeID id1 = ffi_checkctype(L, cts, NULL);
 589   TValue *o = lj_lib_checkany(L, 2);
 590   int b = 0;
 591   if (tviscdata(o)) {
 592     GCcdata *cd = cdataV(o);
 593     CTypeID id2 = cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) :
 594                                                 cd->ctypeid;
 595     CType *ct1 = lj_ctype_rawref(cts, id1);
 596     CType *ct2 = lj_ctype_rawref(cts, id2);
 597     if (ct1 == ct2) {
 598       b = 1;
 599     } else if (ctype_type(ct1->info) == ctype_type(ct2->info) &&
 600                ct1->size == ct2->size) {
 601       if (ctype_ispointer(ct1->info))
 602         b = lj_cconv_compatptr(cts, ct1, ct2, CCF_IGNQUAL);
 603       else if (ctype_isnum(ct1->info) || ctype_isvoid(ct1->info))
 604         b = (((ct1->info ^ ct2->info) & ~(CTF_QUAL|CTF_LONG)) == 0);
 605     } else if (ctype_isstruct(ct1->info) && ctype_isptr(ct2->info) &&
 606                ct1 == ctype_rawchild(cts, ct2)) {
 607       b = 1;
 608     }
 609   }
 610   setboolV(L->top-1, b);
 611   setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
 612   return 1;
 613 }
 614
 615 LJLIB_CF(ffi_sizeof)    LJLIB_REC(ffi_xof FF_ffi_sizeof)
 616 {
 617   CTState *cts = ctype_cts(L);
 618   CTypeID id = ffi_checkctype(L, cts, NULL);
 619   CTSize sz;
 620   if (LJ_UNLIKELY(tviscdata(L->base) && cdataisv(cdataV(L->base)))) {
 621     sz = cdatavlen(cdataV(L->base));
 622   } else {
 623     CType *ct = lj_ctype_rawref(cts, id);
 624     if (ctype_isvltype(ct->info))
 625       sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
 626     else
 627       sz = ctype_hassize(ct->info) ? ct->size : CTSIZE_INVALID;
 628     if (LJ_UNLIKELY(sz == CTSIZE_INVALID)) {
 629       setnilV(L->top-1);
 630       return 1;
 631     }
 632   }
 633   setintV(L->top-1, (int32_t)sz);
 634   return 1;
 635 }
 636
 637 LJLIB_CF(ffi_alignof)   LJLIB_REC(ffi_xof FF_ffi_alignof)
 638 {
 639   CTState *cts = ctype_cts(L);
 640   CTypeID id = ffi_checkctype(L, cts, NULL);
 641   CTSize sz = 0;
 642   CTInfo info = lj_ctype_info_raw(cts, id, &sz);
 643   setintV(L->top-1, 1 << ctype_align(info));
 644   return 1;
 645 }
 646
 647 LJLIB_CF(ffi_offsetof)  LJLIB_REC(ffi_xof FF_ffi_offsetof)
 648 {
 649   CTState *cts = ctype_cts(L);
 650   CTypeID id = ffi_checkctype(L, cts, NULL);
 651   GCstr *name = lj_lib_checkstr(L, 2);
 652   CType *ct = lj_ctype_rawref(cts, id);
 653   CTSize ofs;
 654   if (ctype_isstruct(ct->info) && ct->size != CTSIZE_INVALID) {
 655     CType *fct = lj_ctype_getfield(cts, ct, name, &ofs);
 656     if (fct) {
 657       setintV(L->top-1, ofs);
 658       if (ctype_isfield(fct->info)) {
 659         return 1;
 660       } else if (ctype_isbitfield(fct->info)) {
 661         setintV(L->top++, ctype_bitpos(fct->info));
 662         setintV(L->top++, ctype_bitbsz(fct->info));
 663         return 3;
 664       }
 665     }
 666   }
 667   return 0;
 668 }
 669
 670 LJLIB_CF(ffi_errno)     LJLIB_REC(.)
 671 {
 672   int err = errno;
 673   if (L->top > L->base)
 674     errno = ffi_checkint(L, 1);
 675   setintV(L->top++, err);
 676   return 1;
 677 }
 678
 679 LJLIB_CF(ffi_string)    LJLIB_REC(.)
 680 {
 681   CTState *cts = ctype_cts(L);
 682   TValue *o = lj_lib_checkany(L, 1);
 683   const char *p;
 684   size_t len;
 685   if (o+1 < L->top && !tvisnil(o+1)) {
 686     len = (size_t)ffi_checkint(L, 2);
 687     lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p, o,
 688                    CCF_ARG(1));
 689   } else {
 690     lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CCHAR), (uint8_t *)&p, o,
 691                    CCF_ARG(1));
 692     len = strlen(p);
 693   }
 694   L->top = o+1;  /* Make sure this is the last item on the stack. */
 695   setstrV(L, o, lj_str_new(L, p, len));
 696   lj_gc_check(L);
 697   return 1;
 698 }
 699
 700 LJLIB_CF(ffi_copy)      LJLIB_REC(.)
 701 {
 702   void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
 703   void *sp = ffi_checkptr(L, 2, CTID_P_CVOID);
 704   TValue *o = L->base+1;
 705   CTSize len;
 706   if (tvisstr(o) && o+1 >= L->top)
 707     len = strV(o)->len+1;  /* Copy Lua string including trailing '\0'. */
 708   else
 709     len = (CTSize)ffi_checkint(L, 3);
 710   memcpy(dp, sp, len);
 711   return 0;
 712 }
 713
 714 LJLIB_CF(ffi_fill)      LJLIB_REC(.)
 715 {
 716   void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
 717   CTSize len = (CTSize)ffi_checkint(L, 2);
 718   int32_t fill = 0;
 719   if (L->base+2 < L->top && !tvisnil(L->base+2)) fill = ffi_checkint(L, 3);
 720   memset(dp, fill, len);
 721   return 0;
 722 }
 723
 724 /* Test ABI string. */
 725 LJLIB_CF(ffi_abi)       LJLIB_REC(.)
 726 {
 727   GCstr *s = lj_lib_checkstr(L, 1);
 728   int b = lj_cparse_case(s,
 729 #if LJ_64
 730     "\00564bit"
 731 #else
 732     "\00532bit"
 733 #endif
 734 #if LJ_ARCH_HASFPU
 735     "\003fpu"
 736 #endif
 737 #if LJ_ABI_SOFTFP
 738     "\006softfp"
 739 #else
 740     "\006hardfp"
 741 #endif
 742 #if LJ_ABI_EABI
 743     "\004eabi"
 744 #endif
 745 #if LJ_ABI_WIN
 746     "\003win"
 747 #endif
 748 #if LJ_ABI_PAUTH
 749     "\005pauth"
 750 #endif
 751 #if LJ_TARGET_UWP
 752     "\003uwp"
 753 #endif
 754 #if LJ_LE
 755     "\002le"
 756 #else
 757     "\002be"
 758 #endif
 759 #if LJ_GC64
 760     "\004gc64"
 761 #endif
 762   ) >= 0;
 763   setboolV(L->top-1, b);
 764   setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
 765   return 1;
 766 }
 767
 768 LJLIB_PUSH(top-7) LJLIB_SET(!)  /* Store reference to miscmap table. */
 769
 770 LJLIB_CF(ffi_metatype)
 771 {
 772   CTState *cts = ctype_cts(L);
 773   CTypeID id = ffi_checkctype(L, cts, NULL);
 774   GCtab *mt = lj_lib_checktab(L, 2);
 775   GCtab *t = cts->miscmap;
 776   CType *ct = ctype_raw(cts, id);
 777   TValue *tv;
 778   GCcdata *cd;
 779   if (!(ctype_isstruct(ct->info) || ctype_iscomplex(ct->info) ||
 780         ctype_isvector(ct->info)))
 781     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 782   tv = lj_tab_setinth(L, t, -(int32_t)ctype_typeid(cts, ct));
 783   if (!tvisnil(tv))
 784     lj_err_caller(L, LJ_ERR_PROTMT);
 785   settabV(L, tv, mt);
 786   lj_gc_anybarriert(L, t);
 787   cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
 788   *(CTypeID *)cdataptr(cd) = id;
 789   setcdataV(L, L->top-1, cd);
 790   lj_gc_check(L);
 791   return 1;
 792 }
 793
 794 LJLIB_CF(ffi_gc)        LJLIB_REC(.)
 795 {
 796   GCcdata *cd = ffi_checkcdata(L, 1);
 797   TValue *fin = lj_lib_checkany(L, 2);
 798   CTState *cts = ctype_cts(L);
 799   CType *ct = ctype_raw(cts, cd->ctypeid);
 800   if (!(ctype_isptr(ct->info) || ctype_isstruct(ct->info) ||
 801         ctype_isrefarray(ct->info)))
 802     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 803   lj_cdata_setfin(L, cd, gcval(fin), itype(fin));
 804   L->top = L->base+1;  /* Pass through the cdata object. */
 805   return 1;
 806 }
 807
 808 LJLIB_PUSH(top-5) LJLIB_SET(!)  /* Store clib metatable in func environment. */
 809
 810 LJLIB_CF(ffi_load)
 811 {
 812   GCstr *name = lj_lib_checkstr(L, 1);
 813   int global = (L->base+1 < L->top && tvistruecond(L->base+1));
 814   lj_clib_load(L, tabref(curr_func(L)->c.env), name, global);
 815   return 1;
 816 }
 817
 818 LJLIB_PUSH(top-4) LJLIB_SET(C)
 819 LJLIB_PUSH(top-3) LJLIB_SET(os)
 820 LJLIB_PUSH(top-2) LJLIB_SET(arch)
 821
 822 #include "lj_libdef.h"
 823
 824 /* ------------------------------------------------------------------------ */
 825
 826 /* Register FFI module as loaded. */
 827 static void ffi_register_module(lua_State *L)
 828 {
 829   cTValue *tmp = lj_tab_getstr(tabV(registry(L)), lj_str_newlit(L, "_LOADED"));
 830   if (tmp && tvistab(tmp)) {
 831     GCtab *t = tabV(tmp);
 832     copyTV(L, lj_tab_setstr(L, t, lj_str_newlit(L, LUA_FFILIBNAME)), L->top-1);
 833     lj_gc_anybarriert(L, t);
 834   }
 835 }
 836
 837 LUALIB_API int luaopen_ffi(lua_State *L)
 838 {
 839   CTState *cts = lj_ctype_init(L);
 840   settabV(L, L->top++, (cts->miscmap = lj_tab_new(L, 0, 1)));
 841   LJ_LIB_REG(L, NULL, ffi_meta);
 842   /* NOBARRIER: basemt is a GC root. */
 843   setgcref(basemt_it(G(L), LJ_TCDATA), obj2gco(tabV(L->top-1)));
 844   LJ_LIB_REG(L, NULL, ffi_clib);
 845   LJ_LIB_REG(L, NULL, ffi_callback);
 846   /* NOBARRIER: the key is new and lj_tab_newkey() handles the barrier. */
 847   settabV(L, lj_tab_setstr(L, cts->miscmap, &cts->g->strempty), tabV(L->top-1));
 848   L->top--;
 849   lj_clib_default(L, tabV(L->top-1));  /* Create ffi.C default namespace. */
 850   lua_pushliteral(L, LJ_OS_NAME);
 851   lua_pushliteral(L, LJ_ARCH_NAME);
 852   LJ_LIB_REG(L, NULL, ffi);  /* Note: no global "ffi" created! */
 853   ffi_register_module(L);
 854   return 1;
 855 }
 856
 857 #endif