src/lib_ffi.c

   1 /*
   2 ** FFI library.
   3 ** Copyright (C) 2005-2011 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_clib.h"
  31 #include "lj_ff.h"
  32 #include "lj_lib.h"
  33
  34 /* -- C type checks ------------------------------------------------------- */
  35
  36 /* Check first argument for a C type and returns its ID. */
  37 static CTypeID ffi_checkctype(lua_State *L, CTState *cts)
  38 {
  39   TValue *o = L->base;
  40   if (!(o < L->top)) {
  41   err_argtype:
  42     lj_err_argtype(L, 1, "C type");
  43   }
  44   if (tvisstr(o)) {  /* Parse an abstract C type declaration. */
  45     GCstr *s = strV(o);
  46     CPState cp;
  47     int errcode;
  48     cp.L = L;
  49     cp.cts = cts;
  50     cp.srcname = strdata(s);
  51     cp.p = strdata(s);
  52     cp.mode = CPARSE_MODE_ABSTRACT|CPARSE_MODE_NOIMPLICIT;
  53     errcode = lj_cparse(&cp);
  54     if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */
  55     return cp.val.id;
  56   } else {
  57     GCcdata *cd;
  58     if (!tviscdata(o)) goto err_argtype;
  59     cd = cdataV(o);
  60     return cd->typeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) : cd->typeid;
  61   }
  62 }
  63
  64 /* Check argument for C data and return it. */
  65 static GCcdata *ffi_checkcdata(lua_State *L, int narg)
  66 {
  67   TValue *o = L->base + narg-1;
  68   if (!(o < L->top && tviscdata(o)))
  69     lj_err_argt(L, narg, LUA_TCDATA);
  70   return cdataV(o);
  71 }
  72
  73 /* Convert argument to C pointer. */
  74 static void *ffi_checkptr(lua_State *L, int narg, CTypeID id)
  75 {
  76   CTState *cts = ctype_cts(L);
  77   TValue *o = L->base + narg-1;
  78   void *p;
  79   if (o >= L->top)
  80     lj_err_arg(L, narg, LJ_ERR_NOVAL);
  81   lj_cconv_ct_tv(cts, ctype_get(cts, id), (uint8_t *)&p, o, CCF_ARG(narg));
  82   return p;
  83 }
  84
  85 /* Convert argument to int32_t. */
  86 static int32_t ffi_checkint(lua_State *L, int narg)
  87 {
  88   CTState *cts = ctype_cts(L);
  89   TValue *o = L->base + narg-1;
  90   int32_t i;
  91   if (o >= L->top)
  92     lj_err_arg(L, narg, LJ_ERR_NOVAL);
  93   lj_cconv_ct_tv(cts, ctype_get(cts, CTID_INT32), (uint8_t *)&i, o,
  94                  CCF_ARG(narg));
  95   return i;
  96 }
  97
  98 /* -- C type metamethods -------------------------------------------------- */
  99
 100 #define LJLIB_MODULE_ffi_meta
 101
 102 /* Handle ctype __index/__newindex metamethods. */
 103 static int ffi_index_meta(lua_State *L, CTState *cts, CType *ct, MMS mm)
 104 {
 105   CTypeID id = ctype_typeid(cts, ct);
 106   cTValue *tv = lj_ctype_meta(cts, id, mm);
 107   TValue *base = L->base;
 108   if (!tv) {
 109     const char *s;
 110   err_index:
 111     s = strdata(lj_ctype_repr(L, id, NULL));
 112     if (tvisstr(L->base+1))
 113       lj_err_callerv(L, LJ_ERR_FFI_BADMEMBER, s, strVdata(L->base+1));
 114     else
 115       lj_err_callerv(L, LJ_ERR_FFI_BADIDX, s);
 116   }
 117   if (!tvisfunc(tv)) {
 118     if (mm == MM_index) {
 119       cTValue *o = lj_meta_tget(L, tv, base+1);
 120       if (o) {
 121         if (tvisnil(o)) goto err_index;
 122         copyTV(L, L->top-1, o);
 123         return 1;
 124       }
 125     } else {
 126       TValue *o = lj_meta_tset(L, tv, base+1);
 127       if (o) {
 128         copyTV(L, o, base+2);
 129         return 0;
 130       }
 131     }
 132     tv = L->top-1;
 133   }
 134   return lj_meta_tailcall(L, tv);
 135 }
 136
 137 LJLIB_CF(ffi_meta___index)      LJLIB_REC(cdata_index 0)
 138 {
 139   CTState *cts = ctype_cts(L);
 140   CTInfo qual = 0;
 141   CType *ct;
 142   uint8_t *p;
 143   TValue *o = L->base;
 144   if (!(o+1 < L->top && tviscdata(o)))  /* Also checks for presence of key. */
 145     lj_err_argt(L, 1, LUA_TCDATA);
 146   ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
 147   if ((qual & 1))
 148     return ffi_index_meta(L, cts, ct, MM_index);
 149   if (lj_cdata_get(cts, ct, L->top-1, p))
 150     lj_gc_check(L);
 151   return 1;
 152 }
 153
 154 LJLIB_CF(ffi_meta___newindex)   LJLIB_REC(cdata_index 1)
 155 {
 156   CTState *cts = ctype_cts(L);
 157   CTInfo qual = 0;
 158   CType *ct;
 159   uint8_t *p;
 160   TValue *o = L->base;
 161   if (!(o+2 < L->top && tviscdata(o)))  /* Also checks for key and value. */
 162     lj_err_argt(L, 1, LUA_TCDATA);
 163   ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
 164   if ((qual & 1)) {
 165     if ((qual & CTF_CONST))
 166       lj_err_caller(L, LJ_ERR_FFI_WRCONST);
 167     return ffi_index_meta(L, cts, ct, MM_newindex);
 168   }
 169   lj_cdata_set(cts, ct, p, o+2, qual);
 170   return 0;
 171 }
 172
 173 /* Common handler for cdata arithmetic. */
 174 static int ffi_arith(lua_State *L)
 175 {
 176   MMS mm = (MMS)(curr_func(L)->c.ffid - (int)FF_ffi_meta___eq + (int)MM_eq);
 177   return lj_carith_op(L, mm);
 178 }
 179
 180 /* The following functions must be in contiguous ORDER MM. */
 181 LJLIB_CF(ffi_meta___eq)         LJLIB_REC(cdata_arith MM_eq)
 182 {
 183   return ffi_arith(L);
 184 }
 185
 186 LJLIB_CF(ffi_meta___len)        LJLIB_REC(cdata_arith MM_len)
 187 {
 188   return ffi_arith(L);
 189 }
 190
 191 LJLIB_CF(ffi_meta___lt)         LJLIB_REC(cdata_arith MM_lt)
 192 {
 193   return ffi_arith(L);
 194 }
 195
 196 LJLIB_CF(ffi_meta___le)         LJLIB_REC(cdata_arith MM_le)
 197 {
 198   return ffi_arith(L);
 199 }
 200
 201 LJLIB_CF(ffi_meta___concat)     LJLIB_REC(cdata_arith MM_concat)
 202 {
 203   return ffi_arith(L);
 204 }
 205
 206 /* Handle ctype __call metamethod. */
 207 static int ffi_call_meta(lua_State *L, CTypeID id)
 208 {
 209   CTState *cts = ctype_cts(L);
 210   cTValue *tv = lj_ctype_meta(cts, id, MM_call);
 211   if (!tv)
 212     lj_err_callerv(L, LJ_ERR_FFI_BADCALL, strdata(lj_ctype_repr(L, id, NULL)));
 213   return lj_meta_tailcall(L, tv);
 214 }
 215
 216 /* Forward declaration. */
 217 static int lj_cf_ffi_new(lua_State *L);
 218
 219 LJLIB_CF(ffi_meta___call)       LJLIB_REC(cdata_call)
 220 {
 221   GCcdata *cd = ffi_checkcdata(L, 1);
 222   int ret;
 223   if (cd->typeid == CTID_CTYPEID)
 224     return lj_cf_ffi_new(L);
 225   if ((ret = lj_ccall_func(L, cd)) < 0)
 226     return ffi_call_meta(L, cd->typeid);
 227   return ret;
 228 }
 229
 230 LJLIB_CF(ffi_meta___add)        LJLIB_REC(cdata_arith MM_add)
 231 {
 232   return ffi_arith(L);
 233 }
 234
 235 LJLIB_CF(ffi_meta___sub)        LJLIB_REC(cdata_arith MM_sub)
 236 {
 237   return ffi_arith(L);
 238 }
 239
 240 LJLIB_CF(ffi_meta___mul)        LJLIB_REC(cdata_arith MM_mul)
 241 {
 242   return ffi_arith(L);
 243 }
 244
 245 LJLIB_CF(ffi_meta___div)        LJLIB_REC(cdata_arith MM_div)
 246 {
 247   return ffi_arith(L);
 248 }
 249
 250 LJLIB_CF(ffi_meta___mod)        LJLIB_REC(cdata_arith MM_mod)
 251 {
 252   return ffi_arith(L);
 253 }
 254
 255 LJLIB_CF(ffi_meta___pow)        LJLIB_REC(cdata_arith MM_pow)
 256 {
 257   return ffi_arith(L);
 258 }
 259
 260 LJLIB_CF(ffi_meta___unm)        LJLIB_REC(cdata_arith MM_unm)
 261 {
 262   return ffi_arith(L);
 263 }
 264 /* End of contiguous ORDER MM. */
 265
 266 LJLIB_CF(ffi_meta___tostring)
 267 {
 268   GCcdata *cd = ffi_checkcdata(L, 1);
 269   const char *msg = "cdata<%s>: %p";
 270   CTypeID id = cd->typeid;
 271   void *p = cdataptr(cd);
 272   if (id == CTID_CTYPEID) {
 273     msg = "ctype<%s>";
 274     id = *(CTypeID *)p;
 275   } else {
 276     CTState *cts = ctype_cts(L);
 277     CType *ct = ctype_raw(cts, id);
 278     if (ctype_isref(ct->info)) ct = ctype_rawchild(cts, ct);
 279     if (ctype_iscomplex(ct->info)) {
 280       setstrV(L, L->top-1, lj_ctype_repr_complex(L, cdataptr(cd), ct->size));
 281       goto checkgc;
 282     } else if (ct->size == 8 && ctype_isinteger(ct->info)) {
 283       setstrV(L, L->top-1, lj_ctype_repr_int64(L, *(uint64_t *)cdataptr(cd),
 284                                                (ct->info & CTF_UNSIGNED)));
 285       goto checkgc;
 286     } else if (ctype_isfunc(ct->info)) {
 287       p = *(void **)p;
 288     } else {
 289       if (ctype_isptr(ct->info)) {
 290         p = cdata_getptr(p, ct->size);
 291         ct = ctype_rawchild(cts, ct);
 292       }
 293       if (ctype_isstruct(ct->info) || ctype_isvector(ct->info)) {
 294         /* Handle ctype __tostring metamethod. */
 295         cTValue *tv = lj_ctype_meta(cts, ctype_typeid(cts, ct), MM_tostring);
 296         if (tv)
 297           return lj_meta_tailcall(L, tv);
 298       }
 299     }
 300   }
 301   lj_str_pushf(L, msg, strdata(lj_ctype_repr(L, id, NULL)), p);
 302 checkgc:
 303   lj_gc_check(L);
 304   return 1;
 305 }
 306
 307 LJLIB_PUSH("ffi") LJLIB_SET(__metatable)
 308
 309 #include "lj_libdef.h"
 310
 311 /* -- C library metamethods ----------------------------------------------- */
 312
 313 #define LJLIB_MODULE_ffi_clib
 314
 315 /* Index C library by a name. */
 316 static TValue *ffi_clib_index(lua_State *L)
 317 {
 318   TValue *o = L->base;
 319   CLibrary *cl;
 320   if (!(o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB))
 321     lj_err_argt(L, 1, LUA_TUSERDATA);
 322   cl = (CLibrary *)uddata(udataV(o));
 323   if (!(o+1 < L->top && tvisstr(o+1)))
 324     lj_err_argt(L, 2, LUA_TSTRING);
 325   return lj_clib_index(L, cl, strV(o+1));
 326 }
 327
 328 LJLIB_CF(ffi_clib___index)      LJLIB_REC(clib_index 1)
 329 {
 330   TValue *tv = ffi_clib_index(L);
 331   if (tviscdata(tv)) {
 332     CTState *cts = ctype_cts(L);
 333     GCcdata *cd = cdataV(tv);
 334     CType *s = ctype_get(cts, cd->typeid);
 335     if (ctype_isextern(s->info)) {
 336       CTypeID sid = ctype_cid(s->info);
 337       void *sp = *(void **)cdataptr(cd);
 338       CType *ct = ctype_raw(cts, sid);
 339       if (ctype_isenum(ct->info)) ct = ctype_child(cts, ct);
 340       if (lj_cconv_tv_ct(cts, ct, sid, L->top-1, sp))
 341         lj_gc_check(L);
 342       return 1;
 343     }
 344   }
 345   copyTV(L, L->top-1, tv);
 346   return 1;
 347 }
 348
 349 LJLIB_CF(ffi_clib___newindex)   LJLIB_REC(clib_index 0)
 350 {
 351   TValue *tv = ffi_clib_index(L);
 352   TValue *o = L->base+2;
 353   if (o < L->top && tviscdata(tv)) {
 354     CTState *cts = ctype_cts(L);
 355     GCcdata *cd = cdataV(tv);
 356     CType *d = ctype_get(cts, cd->typeid);
 357     if (ctype_isextern(d->info)) {
 358       CTInfo qual = 0;
 359       for (;;) {  /* Skip attributes and collect qualifiers. */
 360         d = ctype_child(cts, d);
 361         if (!ctype_isattrib(d->info)) break;
 362         if (ctype_attrib(d->info) == CTA_QUAL) qual |= d->size;
 363       }
 364       if (!((d->info|qual) & CTF_CONST)) {
 365         lj_cconv_ct_tv(cts, d, *(void **)cdataptr(cd), o, 0);
 366         return 0;
 367       }
 368     }
 369   }
 370   lj_err_caller(L, LJ_ERR_FFI_WRCONST);
 371   return 0;  /* unreachable */
 372 }
 373
 374 LJLIB_CF(ffi_clib___gc)
 375 {
 376   TValue *o = L->base;
 377   if (o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB)
 378     lj_clib_unload((CLibrary *)uddata(udataV(o)));
 379   return 0;
 380 }
 381
 382 #include "lj_libdef.h"
 383
 384 /* -- FFI library functions ----------------------------------------------- */
 385
 386 #define LJLIB_MODULE_ffi
 387
 388 LJLIB_CF(ffi_cdef)
 389 {
 390   GCstr *s = lj_lib_checkstr(L, 1);
 391   CPState cp;
 392   int errcode;
 393   cp.L = L;
 394   cp.cts = ctype_cts(L);
 395   cp.srcname = strdata(s);
 396   cp.p = strdata(s);
 397   cp.mode = CPARSE_MODE_MULTI|CPARSE_MODE_DIRECT;
 398   errcode = lj_cparse(&cp);
 399   if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */
 400   lj_gc_check(L);
 401   return 0;
 402 }
 403
 404 LJLIB_CF(ffi_new)       LJLIB_REC(.)
 405 {
 406   CTState *cts = ctype_cts(L);
 407   CTypeID id = ffi_checkctype(L, cts);
 408   CType *ct = ctype_raw(cts, id);
 409   CTSize sz;
 410   CTInfo info = lj_ctype_info(cts, id, &sz);
 411   TValue *o = L->base+1;
 412   GCcdata *cd;
 413   if ((info & CTF_VLA)) {
 414     o++;
 415     sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
 416   }
 417   if (sz == CTSIZE_INVALID)
 418     lj_err_arg(L, 1, LJ_ERR_FFI_INVSIZE);
 419   if (!(info & CTF_VLA) && ctype_align(info) <= CT_MEMALIGN)
 420     cd = lj_cdata_new(cts, id, sz);
 421   else
 422     cd = lj_cdata_newv(cts, id, sz, ctype_align(info));
 423   setcdataV(L, o-1, cd);  /* Anchor the uninitialized cdata. */
 424   lj_cconv_ct_init(cts, ct, sz, cdataptr(cd),
 425                    o, (MSize)(L->top - o));  /* Initialize cdata. */
 426   if (ctype_isstruct(ct->info)) {
 427     /* Handle ctype __gc metamethod. Use the fast lookup here. */
 428     cTValue *tv = lj_tab_getint(cts->metatype, (int32_t)id);
 429     if (tv && tvistab(tv) && (tv = lj_meta_fast(L, tabV(tv), MM_gc))) {
 430       GCtab *t = cts->finalizer;
 431       if (gcref(t->metatable)) {
 432         /* Add to finalizer table, if still enabled. */
 433         copyTV(L, lj_tab_set(L, t, o-1), tv);
 434         lj_gc_anybarriert(L, t);
 435         cd->marked |= LJ_GC_CDATA_FIN;
 436       }
 437     }
 438   }
 439   L->top = o;  /* Only return the cdata itself. */
 440   lj_gc_check(L);
 441   return 1;
 442 }
 443
 444 LJLIB_CF(ffi_cast)      LJLIB_REC(ffi_new)
 445 {
 446   CTState *cts = ctype_cts(L);
 447   CTypeID id = ffi_checkctype(L, cts);
 448   CType *d = ctype_raw(cts, id);
 449   TValue *o = lj_lib_checkany(L, 2);
 450   L->top = o+1;  /* Make sure this is the last item on the stack. */
 451   if (!(ctype_isnum(d->info) || ctype_isptr(d->info) || ctype_isenum(d->info)))
 452     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 453   if (!(tviscdata(o) && cdataV(o)->typeid == id)) {
 454     GCcdata *cd = lj_cdata_new(cts, id, d->size);
 455     lj_cconv_ct_tv(cts, d, cdataptr(cd), o, CCF_CAST);
 456     setcdataV(L, o, cd);
 457     lj_gc_check(L);
 458   }
 459   return 1;
 460 }
 461
 462 LJLIB_CF(ffi_typeof)
 463 {
 464   CTState *cts = ctype_cts(L);
 465   CTypeID id = ffi_checkctype(L, cts);
 466   GCcdata *cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
 467   *(CTypeID *)cdataptr(cd) = id;
 468   setcdataV(L, L->top-1, cd);
 469   lj_gc_check(L);
 470   return 1;
 471 }
 472
 473 LJLIB_CF(ffi_istype)    LJLIB_REC(ffi_istype)
 474 {
 475   CTState *cts = ctype_cts(L);
 476   CTypeID id1 = ffi_checkctype(L, cts);
 477   TValue *o = lj_lib_checkany(L, 2);
 478   int b = 0;
 479   if (tviscdata(o)) {
 480     GCcdata *cd = cdataV(o);
 481     CTypeID id2 = cd->typeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) :
 482                                                cd->typeid;
 483     CType *ct1 = lj_ctype_rawref(cts, id1);
 484     CType *ct2 = lj_ctype_rawref(cts, id2);
 485     if (ct1 == ct2) {
 486       b = 1;
 487     } else if (ctype_type(ct1->info) == ctype_type(ct2->info) &&
 488                ct1->size == ct2->size) {
 489       if (ctype_ispointer(ct1->info))
 490         b = lj_cconv_compatptr(cts, ct1, ct2, CCF_IGNQUAL);
 491       else if (ctype_isnum(ct1->info) || ctype_isvoid(ct1->info))
 492         b = (((ct1->info ^ ct2->info) & ~CTF_QUAL) == 0);
 493     } else if (ctype_isstruct(ct1->info) && ctype_isptr(ct2->info) &&
 494                ct1 == ctype_rawchild(cts, ct2)) {
 495       b = 1;
 496     }
 497   }
 498   setboolV(L->top-1, b);
 499   setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
 500   return 1;
 501 }
 502
 503 LJLIB_CF(ffi_sizeof)
 504 {
 505   CTState *cts = ctype_cts(L);
 506   CTypeID id = ffi_checkctype(L, cts);
 507   CTSize sz;
 508   if (LJ_UNLIKELY(tviscdata(L->base) && cdataisv(cdataV(L->base)))) {
 509     sz = cdatavlen(cdataV(L->base));
 510   } else {
 511     CType *ct = lj_ctype_rawref(cts, id);
 512     if (ctype_isvltype(ct->info))
 513       sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
 514     else
 515       sz = ctype_hassize(ct->info) ? ct->size : CTSIZE_INVALID;
 516     if (LJ_UNLIKELY(sz == CTSIZE_INVALID)) {
 517       setnilV(L->top-1);
 518       return 1;
 519     }
 520   }
 521   setintV(L->top-1, (int32_t)sz);
 522   return 1;
 523 }
 524
 525 LJLIB_CF(ffi_alignof)
 526 {
 527   CTState *cts = ctype_cts(L);
 528   CTypeID id = ffi_checkctype(L, cts);
 529   CTSize sz = 0;
 530   CTInfo info = lj_ctype_info(cts, id, &sz);
 531   setintV(L->top-1, 1 << ctype_align(info));
 532   return 1;
 533 }
 534
 535 LJLIB_CF(ffi_offsetof)
 536 {
 537   CTState *cts = ctype_cts(L);
 538   CTypeID id = ffi_checkctype(L, cts);
 539   GCstr *name = lj_lib_checkstr(L, 2);
 540   CType *ct = lj_ctype_rawref(cts, id);
 541   CTSize ofs;
 542   if (ctype_isstruct(ct->info) && ct->size != CTSIZE_INVALID) {
 543     CType *fct = lj_ctype_getfield(cts, ct, name, &ofs);
 544     if (fct) {
 545       setintV(L->top-1, ofs);
 546       if (ctype_isfield(fct->info)) {
 547         return 1;
 548       } else if (ctype_isbitfield(fct->info)) {
 549         setintV(L->top++, ctype_bitpos(fct->info));
 550         setintV(L->top++, ctype_bitbsz(fct->info));
 551         return 3;
 552       }
 553     }
 554   }
 555   return 0;
 556 }
 557
 558 LJLIB_CF(ffi_errno)
 559 {
 560   int err = errno;
 561   if (L->top > L->base)
 562     errno = ffi_checkint(L, 1);
 563   setintV(L->top++, err);
 564   return 1;
 565 }
 566
 567 LJLIB_CF(ffi_string)    LJLIB_REC(.)
 568 {
 569   CTState *cts = ctype_cts(L);
 570   TValue *o = lj_lib_checkany(L, 1);
 571   const char *p;
 572   size_t len;
 573   if (o+1 < L->top) {
 574     len = (size_t)ffi_checkint(L, 2);
 575     lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p, o,
 576                    CCF_ARG(1));
 577   } else {
 578     lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CCHAR), (uint8_t *)&p, o,
 579                    CCF_ARG(1));
 580     len = strlen(p);
 581   }
 582   L->top = o+1;  /* Make sure this is the last item on the stack. */
 583   setstrV(L, o, lj_str_new(L, p, len));
 584   lj_gc_check(L);
 585   return 1;
 586 }
 587
 588 LJLIB_CF(ffi_copy)      LJLIB_REC(.)
 589 {
 590   void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
 591   void *sp = ffi_checkptr(L, 2, CTID_P_CVOID);
 592   TValue *o = L->base+1;
 593   CTSize len;
 594   if (tvisstr(o) && o+1 >= L->top)
 595     len = strV(o)->len+1;  /* Copy Lua string including trailing '\0'. */
 596   else
 597     len = (CTSize)ffi_checkint(L, 3);
 598   memcpy(dp, sp, len);
 599   return 0;
 600 }
 601
 602 LJLIB_CF(ffi_fill)      LJLIB_REC(.)
 603 {
 604   void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
 605   CTSize len = (CTSize)ffi_checkint(L, 2);
 606   int32_t fill = 0;
 607   if (L->base+2 < L->top && !tvisnil(L->base+2)) fill = ffi_checkint(L, 3);
 608   memset(dp, fill, len);
 609   return 0;
 610 }
 611
 612 #define H_(le, be)      LJ_ENDIAN_SELECT(0x##le, 0x##be)
 613
 614 /* Test ABI string. */
 615 LJLIB_CF(ffi_abi)       LJLIB_REC(.)
 616 {
 617   GCstr *s = lj_lib_checkstr(L, 1);
 618   int b = 0;
 619   switch (s->hash) {
 620 #if LJ_64
 621   case H_(849858eb,ad35fd06): b = 1; break;  /* 64bit */
 622 #else
 623   case H_(662d3c79,d0e22477): b = 1; break;  /* 32bit */
 624 #endif
 625 #if LJ_ARCH_HASFPU
 626   case H_(e33ee463,e33ee463): b = 1; break;  /* fpu */
 627 #endif
 628 #if LJ_ABI_SOFTFP
 629   case H_(61211a23,c2e8c81c): b = 1; break;  /* softfp */
 630 #else
 631   case H_(539417a8,8ce0812f): b = 1; break;  /* hardfp */
 632 #endif
 633 #if LJ_ABI_EABI
 634   case H_(2182df8f,f2ed1152): b = 1; break;  /* eabi */
 635 #endif
 636 #if LJ_ABI_WIN
 637   case H_(4ab624a8,4ab624a8): b = 1; break;  /* win */
 638 #endif
 639   case H_(3af93066,1f001464): b = 1; break;  /* le/be */
 640   default:
 641     break;
 642   }
 643   setboolV(L->top-1, b);
 644   setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
 645   return 1;
 646 }
 647
 648 #undef H_
 649
 650 LJLIB_PUSH(top-8) LJLIB_SET(!)  /* Store reference to metatype table. */
 651
 652 LJLIB_CF(ffi_metatype)
 653 {
 654   CTState *cts = ctype_cts(L);
 655   CTypeID id = ffi_checkctype(L, cts);
 656   GCtab *mt = lj_lib_checktab(L, 2);
 657   GCtab *t = cts->metatype;
 658   CType *ct = ctype_get(cts, id);  /* Only allow raw types. */
 659   TValue *tv;
 660   GCcdata *cd;
 661   if (!(ctype_isstruct(ct->info) || ctype_iscomplex(ct->info) ||
 662         ctype_isvector(ct->info)))
 663     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 664   tv = lj_tab_setint(L, t, (int32_t)id);
 665   if (!tvisnil(tv))
 666     lj_err_caller(L, LJ_ERR_PROTMT);
 667   settabV(L, tv, mt);
 668   lj_gc_anybarriert(L, t);
 669   cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
 670   *(CTypeID *)cdataptr(cd) = id;
 671   setcdataV(L, L->top-1, cd);
 672   lj_gc_check(L);
 673   return 1;
 674 }
 675
 676 LJLIB_PUSH(top-7) LJLIB_SET(!)  /* Store reference to finalizer table. */
 677
 678 LJLIB_CF(ffi_gc)
 679 {
 680   GCcdata *cd = ffi_checkcdata(L, 1);
 681   TValue *fin = lj_lib_checkany(L, 2);
 682   CTState *cts = ctype_cts(L);
 683   GCtab *t = cts->finalizer;
 684   CType *ct = ctype_raw(cts, cd->typeid);
 685   if (!(ctype_isptr(ct->info) || ctype_isstruct(ct->info) ||
 686         ctype_isrefarray(ct->info)))
 687     lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
 688   if (gcref(t->metatable)) {  /* Update finalizer table, if still enabled. */
 689     copyTV(L, lj_tab_set(L, t, L->base), fin);
 690     lj_gc_anybarriert(L, t);
 691     if (!tvisnil(fin))
 692       cd->marked |= LJ_GC_CDATA_FIN;
 693     else
 694       cd->marked &= ~LJ_GC_CDATA_FIN;
 695   }
 696   L->top = L->base+1;  /* Pass through the cdata object. */
 697   return 1;
 698 }
 699
 700 LJLIB_PUSH(top-5) LJLIB_SET(!)  /* Store clib metatable in func environment. */
 701
 702 LJLIB_CF(ffi_load)
 703 {
 704   GCstr *name = lj_lib_checkstr(L, 1);
 705   int global = (L->base+1 < L->top && tvistruecond(L->base+1));
 706   lj_clib_load(L, tabref(curr_func(L)->c.env), name, global);
 707   return 1;
 708 }
 709
 710 LJLIB_PUSH(top-4) LJLIB_SET(C)
 711 LJLIB_PUSH(top-3) LJLIB_SET(os)
 712 LJLIB_PUSH(top-2) LJLIB_SET(arch)
 713
 714 #include "lj_libdef.h"
 715
 716 /* ------------------------------------------------------------------------ */
 717
 718 /* Create special weak-keyed finalizer table. */
 719 static GCtab *ffi_finalizer(lua_State *L)
 720 {
 721   /* NOBARRIER: The table is new (marked white). */
 722   GCtab *t = lj_tab_new(L, 0, 1);
 723   settabV(L, L->top++, t);
 724   setgcref(t->metatable, obj2gco(t));
 725   setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "__mode")),
 726           lj_str_newlit(L, "K"));
 727   t->nomm = (uint8_t)(~(1u<<MM_mode));
 728   return t;
 729 }
 730
 731 /* Register FFI module as loaded. */
 732 static void ffi_register_module(lua_State *L)
 733 {
 734   cTValue *tmp = lj_tab_getstr(tabV(registry(L)), lj_str_newlit(L, "_LOADED"));
 735   if (tmp && tvistab(tmp)) {
 736     GCtab *t = tabV(tmp);
 737     copyTV(L, lj_tab_setstr(L, t, lj_str_newlit(L, LUA_FFILIBNAME)), L->top-1);
 738     lj_gc_anybarriert(L, t);
 739   }
 740 }
 741
 742 LUALIB_API int luaopen_ffi(lua_State *L)
 743 {
 744   CTState *cts = lj_ctype_init(L);
 745   settabV(L, L->top++, (cts->metatype = lj_tab_new(L, 0, 0)));
 746   cts->finalizer = ffi_finalizer(L);
 747   LJ_LIB_REG(L, NULL, ffi_meta);
 748   /* NOBARRIER: basemt is a GC root. */
 749   setgcref(basemt_it(G(L), LJ_TCDATA), obj2gco(tabV(L->top-1)));
 750   LJ_LIB_REG(L, NULL, ffi_clib);
 751   lj_clib_default(L, tabV(L->top-1));  /* Create ffi.C default namespace. */
 752   lua_pushliteral(L, LJ_OS_NAME);
 753   lua_pushliteral(L, LJ_ARCH_NAME);
 754   LJ_LIB_REG(L, NULL, ffi);  /* Note: no global "ffi" created! */
 755   ffi_register_module(L);
 756   return 1;
 757 }
 758
 759 #endif