--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/third_party/luajit/src/lib_ffi.c	Fri Jan 23 22:38:59 2026 -0800
@@ -0,0 +1,873 @@
+/*
+** FFI library.
+** Copyright (C) 2005-2023 Mike Pall. See Copyright Notice in luajit.h
+*/
+
+#define lib_ffi_c
+#define LUA_LIB
+
+#include <errno.h>
+
+#include "lua.h"
+#include "lauxlib.h"
+#include "lualib.h"
+
+#include "lj_obj.h"
+
+#if LJ_HASFFI
+
+#include "lj_gc.h"
+#include "lj_err.h"
+#include "lj_str.h"
+#include "lj_tab.h"
+#include "lj_meta.h"
+#include "lj_ctype.h"
+#include "lj_cparse.h"
+#include "lj_cdata.h"
+#include "lj_cconv.h"
+#include "lj_carith.h"
+#include "lj_ccall.h"
+#include "lj_ccallback.h"
+#include "lj_clib.h"
+#include "lj_strfmt.h"
+#include "lj_ff.h"
+#include "lj_lib.h"
+
+/* -- C type checks ------------------------------------------------------- */
+
+/* Check first argument for a C type and returns its ID. */
+static CTypeID ffi_checkctype(lua_State *L, CTState *cts, TValue *param)
+{
+  TValue *o = L->base;
+  if (!(o < L->top)) {
+  err_argtype:
+    lj_err_argtype(L, 1, "C type");
+  }
+  if (tvisstr(o)) {  /* Parse an abstract C type declaration. */
+    GCstr *s = strV(o);
+    CPState cp;
+    int errcode;
+    cp.L = L;
+    cp.cts = cts;
+    cp.srcname = strdata(s);
+    cp.p = strdata(s);
+    cp.param = param;
+    cp.mode = CPARSE_MODE_ABSTRACT|CPARSE_MODE_NOIMPLICIT;
+    errcode = lj_cparse(&cp);
+    if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */
+    return cp.val.id;
+  } else {
+    GCcdata *cd;
+    if (!tviscdata(o)) goto err_argtype;
+    if (param && param < L->top) lj_err_arg(L, 1, LJ_ERR_FFI_NUMPARAM);
+    cd = cdataV(o);
+    return cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) : cd->ctypeid;
+  }
+}
+
+/* Check argument for C data and return it. */
+static GCcdata *ffi_checkcdata(lua_State *L, int narg)
+{
+  TValue *o = L->base + narg-1;
+  if (!(o < L->top && tviscdata(o)))
+    lj_err_argt(L, narg, LUA_TCDATA);
+  return cdataV(o);
+}
+
+/* Convert argument to C pointer. */
+static void *ffi_checkptr(lua_State *L, int narg, CTypeID id)
+{
+  CTState *cts = ctype_cts(L);
+  TValue *o = L->base + narg-1;
+  void *p;
+  if (o >= L->top)
+    lj_err_arg(L, narg, LJ_ERR_NOVAL);
+  lj_cconv_ct_tv(cts, ctype_get(cts, id), (uint8_t *)&p, o, CCF_ARG(narg));
+  return p;
+}
+
+/* Convert argument to int32_t. */
+static int32_t ffi_checkint(lua_State *L, int narg)
+{
+  CTState *cts = ctype_cts(L);
+  TValue *o = L->base + narg-1;
+  int32_t i;
+  if (o >= L->top)
+    lj_err_arg(L, narg, LJ_ERR_NOVAL);
+  lj_cconv_ct_tv(cts, ctype_get(cts, CTID_INT32), (uint8_t *)&i, o,
+		 CCF_ARG(narg));
+  return i;
+}
+
+/* -- C type metamethods -------------------------------------------------- */
+
+#define LJLIB_MODULE_ffi_meta
+
+/* Handle ctype __index/__newindex metamethods. */
+static int ffi_index_meta(lua_State *L, CTState *cts, CType *ct, MMS mm)
+{
+  CTypeID id = ctype_typeid(cts, ct);
+  cTValue *tv = lj_ctype_meta(cts, id, mm);
+  TValue *base = L->base;
+  if (!tv) {
+    const char *s;
+  err_index:
+    s = strdata(lj_ctype_repr(L, id, NULL));
+    if (tvisstr(L->base+1)) {
+      lj_err_callerv(L, LJ_ERR_FFI_BADMEMBER, s, strVdata(L->base+1));
+    } else {
+      const char *key = tviscdata(L->base+1) ?
+	strdata(lj_ctype_repr(L, cdataV(L->base+1)->ctypeid, NULL)) :
+	lj_typename(L->base+1);
+      lj_err_callerv(L, LJ_ERR_FFI_BADIDXW, s, key);
+    }
+  }
+  if (!tvisfunc(tv)) {
+    if (mm == MM_index) {
+      cTValue *o = lj_meta_tget(L, tv, base+1);
+      if (o) {
+	if (tvisnil(o)) goto err_index;
+	copyTV(L, L->top-1, o);
+	return 1;
+      }
+    } else {
+      TValue *o = lj_meta_tset(L, tv, base+1);
+      if (o) {
+	copyTV(L, o, base+2);
+	return 0;
+      }
+    }
+    copyTV(L, base, L->top);
+    tv = L->top-1-LJ_FR2;
+  }
+  return lj_meta_tailcall(L, tv);
+}
+
+LJLIB_CF(ffi_meta___index)	LJLIB_REC(cdata_index 0)
+{
+  CTState *cts = ctype_cts(L);
+  CTInfo qual = 0;
+  CType *ct;
+  uint8_t *p;
+  TValue *o = L->base;
+  if (!(o+1 < L->top && tviscdata(o)))  /* Also checks for presence of key. */
+    lj_err_argt(L, 1, LUA_TCDATA);
+  ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
+  if ((qual & 1))
+    return ffi_index_meta(L, cts, ct, MM_index);
+  if (lj_cdata_get(cts, ct, L->top-1, p))
+    lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(ffi_meta___newindex)	LJLIB_REC(cdata_index 1)
+{
+  CTState *cts = ctype_cts(L);
+  CTInfo qual = 0;
+  CType *ct;
+  uint8_t *p;
+  TValue *o = L->base;
+  if (!(o+2 < L->top && tviscdata(o)))  /* Also checks for key and value. */
+    lj_err_argt(L, 1, LUA_TCDATA);
+  ct = lj_cdata_index(cts, cdataV(o), o+1, &p, &qual);
+  if ((qual & 1)) {
+    if ((qual & CTF_CONST))
+      lj_err_caller(L, LJ_ERR_FFI_WRCONST);
+    return ffi_index_meta(L, cts, ct, MM_newindex);
+  }
+  lj_cdata_set(cts, ct, p, o+2, qual);
+  return 0;
+}
+
+/* Common handler for cdata arithmetic. */
+static int ffi_arith(lua_State *L)
+{
+  MMS mm = (MMS)(curr_func(L)->c.ffid - (int)FF_ffi_meta___eq + (int)MM_eq);
+  return lj_carith_op(L, mm);
+}
+
+/* The following functions must be in contiguous ORDER MM. */
+LJLIB_CF(ffi_meta___eq)		LJLIB_REC(cdata_arith MM_eq)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___len)	LJLIB_REC(cdata_arith MM_len)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___lt)		LJLIB_REC(cdata_arith MM_lt)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___le)		LJLIB_REC(cdata_arith MM_le)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___concat)	LJLIB_REC(cdata_arith MM_concat)
+{
+  return ffi_arith(L);
+}
+
+/* Forward declaration. */
+static int lj_cf_ffi_new(lua_State *L);
+
+LJLIB_CF(ffi_meta___call)	LJLIB_REC(cdata_call)
+{
+  CTState *cts = ctype_cts(L);
+  GCcdata *cd = ffi_checkcdata(L, 1);
+  CTypeID id = cd->ctypeid;
+  CType *ct;
+  cTValue *tv;
+  MMS mm = MM_call;
+  if (cd->ctypeid == CTID_CTYPEID) {
+    id = *(CTypeID *)cdataptr(cd);
+    mm = MM_new;
+  } else {
+    int ret = lj_ccall_func(L, cd);
+    if (ret >= 0)
+      return ret;
+  }
+  /* Handle ctype __call/__new metamethod. */
+  ct = ctype_raw(cts, id);
+  if (ctype_isptr(ct->info)) id = ctype_cid(ct->info);
+  tv = lj_ctype_meta(cts, id, mm);
+  if (tv)
+    return lj_meta_tailcall(L, tv);
+  else if (mm == MM_call)
+    lj_err_callerv(L, LJ_ERR_FFI_BADCALL, strdata(lj_ctype_repr(L, id, NULL)));
+  return lj_cf_ffi_new(L);
+}
+
+LJLIB_CF(ffi_meta___add)	LJLIB_REC(cdata_arith MM_add)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___sub)	LJLIB_REC(cdata_arith MM_sub)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___mul)	LJLIB_REC(cdata_arith MM_mul)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___div)	LJLIB_REC(cdata_arith MM_div)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___mod)	LJLIB_REC(cdata_arith MM_mod)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___pow)	LJLIB_REC(cdata_arith MM_pow)
+{
+  return ffi_arith(L);
+}
+
+LJLIB_CF(ffi_meta___unm)	LJLIB_REC(cdata_arith MM_unm)
+{
+  return ffi_arith(L);
+}
+/* End of contiguous ORDER MM. */
+
+LJLIB_CF(ffi_meta___tostring)
+{
+  GCcdata *cd = ffi_checkcdata(L, 1);
+  const char *msg = "cdata<%s>: %p";
+  CTypeID id = cd->ctypeid;
+  void *p = cdataptr(cd);
+  if (id == CTID_CTYPEID) {
+    msg = "ctype<%s>";
+    id = *(CTypeID *)p;
+  } else {
+    CTState *cts = ctype_cts(L);
+    CType *ct = ctype_raw(cts, id);
+    if (ctype_isref(ct->info)) {
+      p = *(void **)p;
+      ct = ctype_rawchild(cts, ct);
+    }
+    if (ctype_iscomplex(ct->info)) {
+      setstrV(L, L->top-1, lj_ctype_repr_complex(L, cdataptr(cd), ct->size));
+      goto checkgc;
+    } else if (ct->size == 8 && ctype_isinteger(ct->info)) {
+      setstrV(L, L->top-1, lj_ctype_repr_int64(L, *(uint64_t *)cdataptr(cd),
+					       (ct->info & CTF_UNSIGNED)));
+      goto checkgc;
+    } else if (ctype_isfunc(ct->info)) {
+      p = *(void **)p;
+    } else if (ctype_isenum(ct->info)) {
+      msg = "cdata<%s>: %d";
+      p = (void *)(uintptr_t)*(uint32_t **)p;
+    } else {
+      if (ctype_isptr(ct->info)) {
+	p = cdata_getptr(p, ct->size);
+	ct = ctype_rawchild(cts, ct);
+      }
+      if (ctype_isstruct(ct->info) || ctype_isvector(ct->info)) {
+	/* Handle ctype __tostring metamethod. */
+	cTValue *tv = lj_ctype_meta(cts, ctype_typeid(cts, ct), MM_tostring);
+	if (tv)
+	  return lj_meta_tailcall(L, tv);
+      }
+    }
+  }
+  lj_strfmt_pushf(L, msg, strdata(lj_ctype_repr(L, id, NULL)), p);
+checkgc:
+  lj_gc_check(L);
+  return 1;
+}
+
+static int ffi_pairs(lua_State *L, MMS mm)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkcdata(L, 1)->ctypeid;
+  CType *ct = ctype_raw(cts, id);
+  cTValue *tv;
+  if (ctype_isptr(ct->info)) id = ctype_cid(ct->info);
+  tv = lj_ctype_meta(cts, id, mm);
+  if (!tv)
+    lj_err_callerv(L, LJ_ERR_FFI_BADMM, strdata(lj_ctype_repr(L, id, NULL)),
+		   strdata(mmname_str(G(L), mm)));
+  return lj_meta_tailcall(L, tv);
+}
+
+LJLIB_CF(ffi_meta___pairs)
+{
+  return ffi_pairs(L, MM_pairs);
+}
+
+LJLIB_CF(ffi_meta___ipairs)
+{
+  return ffi_pairs(L, MM_ipairs);
+}
+
+LJLIB_PUSH("ffi") LJLIB_SET(__metatable)
+
+#include "lj_libdef.h"
+
+/* -- C library metamethods ----------------------------------------------- */
+
+#define LJLIB_MODULE_ffi_clib
+
+/* Index C library by a name. */
+static TValue *ffi_clib_index(lua_State *L)
+{
+  TValue *o = L->base;
+  CLibrary *cl;
+  if (!(o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB))
+    lj_err_argt(L, 1, LUA_TUSERDATA);
+  cl = (CLibrary *)uddata(udataV(o));
+  if (!(o+1 < L->top && tvisstr(o+1)))
+    lj_err_argt(L, 2, LUA_TSTRING);
+  return lj_clib_index(L, cl, strV(o+1));
+}
+
+LJLIB_CF(ffi_clib___index)	LJLIB_REC(clib_index 1)
+{
+  TValue *tv = ffi_clib_index(L);
+  if (tviscdata(tv)) {
+    CTState *cts = ctype_cts(L);
+    GCcdata *cd = cdataV(tv);
+    CType *s = ctype_get(cts, cd->ctypeid);
+    if (ctype_isextern(s->info)) {
+      CTypeID sid = ctype_cid(s->info);
+      void *sp = *(void **)cdataptr(cd);
+      CType *ct = ctype_raw(cts, sid);
+      if (lj_cconv_tv_ct(cts, ct, sid, L->top-1, sp))
+	lj_gc_check(L);
+      return 1;
+    }
+  }
+  copyTV(L, L->top-1, tv);
+  return 1;
+}
+
+LJLIB_CF(ffi_clib___newindex)	LJLIB_REC(clib_index 0)
+{
+  TValue *tv = ffi_clib_index(L);
+  TValue *o = L->base+2;
+  if (o < L->top && tviscdata(tv)) {
+    CTState *cts = ctype_cts(L);
+    GCcdata *cd = cdataV(tv);
+    CType *d = ctype_get(cts, cd->ctypeid);
+    if (ctype_isextern(d->info)) {
+      CTInfo qual = 0;
+      for (;;) {  /* Skip attributes and collect qualifiers. */
+	d = ctype_child(cts, d);
+	if (!ctype_isattrib(d->info)) break;
+	if (ctype_attrib(d->info) == CTA_QUAL) qual |= d->size;
+      }
+      if (!((d->info|qual) & CTF_CONST)) {
+	lj_cconv_ct_tv(cts, d, *(void **)cdataptr(cd), o, 0);
+	return 0;
+      }
+    }
+  }
+  lj_err_caller(L, LJ_ERR_FFI_WRCONST);
+  return 0;  /* unreachable */
+}
+
+LJLIB_CF(ffi_clib___gc)
+{
+  TValue *o = L->base;
+  if (o < L->top && tvisudata(o) && udataV(o)->udtype == UDTYPE_FFI_CLIB)
+    lj_clib_unload((CLibrary *)uddata(udataV(o)));
+  return 0;
+}
+
+#include "lj_libdef.h"
+
+/* -- Callback function metamethods --------------------------------------- */
+
+#define LJLIB_MODULE_ffi_callback
+
+static int ffi_callback_set(lua_State *L, GCfunc *fn)
+{
+  GCcdata *cd = ffi_checkcdata(L, 1);
+  CTState *cts = ctype_cts(L);
+  CType *ct = ctype_raw(cts, cd->ctypeid);
+  if (ctype_isptr(ct->info) && (LJ_32 || ct->size == 8)) {
+    MSize slot = lj_ccallback_ptr2slot(cts, *(void **)cdataptr(cd));
+    if (slot < cts->cb.sizeid && cts->cb.cbid[slot] != 0) {
+      GCtab *t = cts->miscmap;
+      TValue *tv = lj_tab_setint(L, t, (int32_t)slot);
+      if (fn) {
+	setfuncV(L, tv, fn);
+	lj_gc_anybarriert(L, t);
+      } else {
+	setnilV(tv);
+	cts->cb.cbid[slot] = 0;
+	cts->cb.topid = slot < cts->cb.topid ? slot : cts->cb.topid;
+      }
+      return 0;
+    }
+  }
+  lj_err_caller(L, LJ_ERR_FFI_BADCBACK);
+  return 0;
+}
+
+LJLIB_CF(ffi_callback_free)
+{
+  return ffi_callback_set(L, NULL);
+}
+
+LJLIB_CF(ffi_callback_set)
+{
+  GCfunc *fn = lj_lib_checkfunc(L, 2);
+  return ffi_callback_set(L, fn);
+}
+
+LJLIB_PUSH(top-1) LJLIB_SET(__index)
+
+#include "lj_libdef.h"
+
+/* -- FFI library functions ----------------------------------------------- */
+
+#define LJLIB_MODULE_ffi
+
+LJLIB_CF(ffi_cdef)
+{
+  GCstr *s = lj_lib_checkstr(L, 1);
+  CPState cp;
+  int errcode;
+  cp.L = L;
+  cp.cts = ctype_cts(L);
+  cp.srcname = strdata(s);
+  cp.p = strdata(s);
+  cp.param = L->base+1;
+  cp.mode = CPARSE_MODE_MULTI|CPARSE_MODE_DIRECT;
+  errcode = lj_cparse(&cp);
+  if (errcode) lj_err_throw(L, errcode);  /* Propagate errors. */
+  lj_gc_check(L);
+  return 0;
+}
+
+LJLIB_CF(ffi_new)	LJLIB_REC(.)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, NULL);
+  CType *ct = ctype_raw(cts, id);
+  CTSize sz;
+  CTInfo info = lj_ctype_info(cts, id, &sz);
+  TValue *o = L->base+1;
+  GCcdata *cd;
+  if ((info & CTF_VLA)) {
+    o++;
+    sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
+  }
+  if (sz == CTSIZE_INVALID)
+    lj_err_arg(L, 1, LJ_ERR_FFI_INVSIZE);
+  cd = lj_cdata_newx(cts, id, sz, info);
+  setcdataV(L, o-1, cd);  /* Anchor the uninitialized cdata. */
+  lj_cconv_ct_init(cts, ct, sz, cdataptr(cd),
+		   o, (MSize)(L->top - o));  /* Initialize cdata. */
+  if (ctype_isstruct(ct->info)) {
+    /* Handle ctype __gc metamethod. Use the fast lookup here. */
+    cTValue *tv = lj_tab_getinth(cts->miscmap, -(int32_t)id);
+    if (tv && tvistab(tv) && (tv = lj_meta_fast(L, tabV(tv), MM_gc))) {
+      GCtab *t = cts->finalizer;
+      if (gcref(t->metatable)) {
+	/* Add to finalizer table, if still enabled. */
+	copyTV(L, lj_tab_set(L, t, o-1), tv);
+	lj_gc_anybarriert(L, t);
+	cd->marked |= LJ_GC_CDATA_FIN;
+      }
+    }
+  }
+  L->top = o;  /* Only return the cdata itself. */
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(ffi_cast)	LJLIB_REC(ffi_new)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, NULL);
+  CType *d = ctype_raw(cts, id);
+  TValue *o = lj_lib_checkany(L, 2);
+  L->top = o+1;  /* Make sure this is the last item on the stack. */
+  if (!(ctype_isnum(d->info) || ctype_isptr(d->info) || ctype_isenum(d->info)))
+    lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
+  if (!(tviscdata(o) && cdataV(o)->ctypeid == id)) {
+    GCcdata *cd = lj_cdata_new(cts, id, d->size);
+    lj_cconv_ct_tv(cts, d, cdataptr(cd), o, CCF_CAST);
+    setcdataV(L, o, cd);
+    lj_gc_check(L);
+  }
+  return 1;
+}
+
+LJLIB_CF(ffi_typeof)	LJLIB_REC(.)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, L->base+1);
+  GCcdata *cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
+  *(CTypeID *)cdataptr(cd) = id;
+  setcdataV(L, L->top-1, cd);
+  lj_gc_check(L);
+  return 1;
+}
+
+/* Internal and unsupported API. */
+LJLIB_CF(ffi_typeinfo)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = (CTypeID)ffi_checkint(L, 1);
+  if (id > 0 && id < cts->top) {
+    CType *ct = ctype_get(cts, id);
+    GCtab *t;
+    lua_createtable(L, 0, 4);  /* Increment hash size if fields are added. */
+    t = tabV(L->top-1);
+    setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "info")), (int32_t)ct->info);
+    if (ct->size != CTSIZE_INVALID)
+      setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "size")), (int32_t)ct->size);
+    if (ct->sib)
+      setintV(lj_tab_setstr(L, t, lj_str_newlit(L, "sib")), (int32_t)ct->sib);
+    if (gcref(ct->name)) {
+      GCstr *s = gco2str(gcref(ct->name));
+      if (isdead(G(L), obj2gco(s))) flipwhite(obj2gco(s));
+      setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "name")), s);
+    }
+    lj_gc_check(L);
+    return 1;
+  }
+  return 0;
+}
+
+LJLIB_CF(ffi_istype)	LJLIB_REC(.)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id1 = ffi_checkctype(L, cts, NULL);
+  TValue *o = lj_lib_checkany(L, 2);
+  int b = 0;
+  if (tviscdata(o)) {
+    GCcdata *cd = cdataV(o);
+    CTypeID id2 = cd->ctypeid == CTID_CTYPEID ? *(CTypeID *)cdataptr(cd) :
+						cd->ctypeid;
+    CType *ct1 = lj_ctype_rawref(cts, id1);
+    CType *ct2 = lj_ctype_rawref(cts, id2);
+    if (ct1 == ct2) {
+      b = 1;
+    } else if (ctype_type(ct1->info) == ctype_type(ct2->info) &&
+	       ct1->size == ct2->size) {
+      if (ctype_ispointer(ct1->info))
+	b = lj_cconv_compatptr(cts, ct1, ct2, CCF_IGNQUAL);
+      else if (ctype_isnum(ct1->info) || ctype_isvoid(ct1->info))
+	b = (((ct1->info ^ ct2->info) & ~(CTF_QUAL|CTF_LONG)) == 0);
+    } else if (ctype_isstruct(ct1->info) && ctype_isptr(ct2->info) &&
+	       ct1 == ctype_rawchild(cts, ct2)) {
+      b = 1;
+    }
+  }
+  setboolV(L->top-1, b);
+  setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
+  return 1;
+}
+
+LJLIB_CF(ffi_sizeof)	LJLIB_REC(ffi_xof FF_ffi_sizeof)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, NULL);
+  CTSize sz;
+  if (LJ_UNLIKELY(tviscdata(L->base) && cdataisv(cdataV(L->base)))) {
+    sz = cdatavlen(cdataV(L->base));
+  } else {
+    CType *ct = lj_ctype_rawref(cts, id);
+    if (ctype_isvltype(ct->info))
+      sz = lj_ctype_vlsize(cts, ct, (CTSize)ffi_checkint(L, 2));
+    else
+      sz = ctype_hassize(ct->info) ? ct->size : CTSIZE_INVALID;
+    if (LJ_UNLIKELY(sz == CTSIZE_INVALID)) {
+      setnilV(L->top-1);
+      return 1;
+    }
+  }
+  setintV(L->top-1, (int32_t)sz);
+  return 1;
+}
+
+LJLIB_CF(ffi_alignof)	LJLIB_REC(ffi_xof FF_ffi_alignof)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, NULL);
+  CTSize sz = 0;
+  CTInfo info = lj_ctype_info_raw(cts, id, &sz);
+  setintV(L->top-1, 1 << ctype_align(info));
+  return 1;
+}
+
+LJLIB_CF(ffi_offsetof)	LJLIB_REC(ffi_xof FF_ffi_offsetof)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, NULL);
+  GCstr *name = lj_lib_checkstr(L, 2);
+  CType *ct = lj_ctype_rawref(cts, id);
+  CTSize ofs;
+  if (ctype_isstruct(ct->info) && ct->size != CTSIZE_INVALID) {
+    CType *fct = lj_ctype_getfield(cts, ct, name, &ofs);
+    if (fct) {
+      setintV(L->top-1, ofs);
+      if (ctype_isfield(fct->info)) {
+	return 1;
+      } else if (ctype_isbitfield(fct->info)) {
+	setintV(L->top++, ctype_bitpos(fct->info));
+	setintV(L->top++, ctype_bitbsz(fct->info));
+	return 3;
+      }
+    }
+  }
+  return 0;
+}
+
+LJLIB_CF(ffi_errno)	LJLIB_REC(.)
+{
+  int err = errno;
+  if (L->top > L->base)
+    errno = ffi_checkint(L, 1);
+  setintV(L->top++, err);
+  return 1;
+}
+
+LJLIB_CF(ffi_string)	LJLIB_REC(.)
+{
+  CTState *cts = ctype_cts(L);
+  TValue *o = lj_lib_checkany(L, 1);
+  const char *p;
+  size_t len;
+  if (o+1 < L->top && !tvisnil(o+1)) {
+    len = (size_t)ffi_checkint(L, 2);
+    lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p, o,
+		   CCF_ARG(1));
+  } else {
+    lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CCHAR), (uint8_t *)&p, o,
+		   CCF_ARG(1));
+    len = strlen(p);
+  }
+  L->top = o+1;  /* Make sure this is the last item on the stack. */
+  setstrV(L, o, lj_str_new(L, p, len));
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(ffi_copy)	LJLIB_REC(.)
+{
+  void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
+  void *sp = ffi_checkptr(L, 2, CTID_P_CVOID);
+  TValue *o = L->base+1;
+  CTSize len;
+  if (tvisstr(o) && o+1 >= L->top)
+    len = strV(o)->len+1;  /* Copy Lua string including trailing '\0'. */
+  else
+    len = (CTSize)ffi_checkint(L, 3);
+  memcpy(dp, sp, len);
+  return 0;
+}
+
+LJLIB_CF(ffi_fill)	LJLIB_REC(.)
+{
+  void *dp = ffi_checkptr(L, 1, CTID_P_VOID);
+  CTSize len = (CTSize)ffi_checkint(L, 2);
+  int32_t fill = 0;
+  if (L->base+2 < L->top && !tvisnil(L->base+2)) fill = ffi_checkint(L, 3);
+  memset(dp, fill, len);
+  return 0;
+}
+
+/* Test ABI string. */
+LJLIB_CF(ffi_abi)	LJLIB_REC(.)
+{
+  GCstr *s = lj_lib_checkstr(L, 1);
+  int b = lj_cparse_case(s,
+#if LJ_64
+    "\00564bit"
+#else
+    "\00532bit"
+#endif
+#if LJ_ARCH_HASFPU
+    "\003fpu"
+#endif
+#if LJ_ABI_SOFTFP
+    "\006softfp"
+#else
+    "\006hardfp"
+#endif
+#if LJ_ABI_EABI
+    "\004eabi"
+#endif
+#if LJ_ABI_WIN
+    "\003win"
+#endif
+#if LJ_ABI_PAUTH
+    "\007pauth"
+#endif
+#if LJ_TARGET_UWP
+    "\003uwp"
+#endif
+#if LJ_LE
+    "\002le"
+#else
+    "\002be"
+#endif
+#if LJ_GC64
+    "\004gc64"
+#endif
+  ) >= 0;
+  setboolV(L->top-1, b);
+  setboolV(&G(L)->tmptv2, b);  /* Remember for trace recorder. */
+  return 1;
+}
+
+LJLIB_PUSH(top-8) LJLIB_SET(!)  /* Store reference to miscmap table. */
+
+LJLIB_CF(ffi_metatype)
+{
+  CTState *cts = ctype_cts(L);
+  CTypeID id = ffi_checkctype(L, cts, NULL);
+  GCtab *mt = lj_lib_checktab(L, 2);
+  GCtab *t = cts->miscmap;
+  CType *ct = ctype_raw(cts, id);
+  TValue *tv;
+  GCcdata *cd;
+  if (!(ctype_isstruct(ct->info) || ctype_iscomplex(ct->info) ||
+	ctype_isvector(ct->info)))
+    lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
+  tv = lj_tab_setinth(L, t, -(int32_t)ctype_typeid(cts, ct));
+  if (!tvisnil(tv))
+    lj_err_caller(L, LJ_ERR_PROTMT);
+  settabV(L, tv, mt);
+  lj_gc_anybarriert(L, t);
+  cd = lj_cdata_new(cts, CTID_CTYPEID, 4);
+  *(CTypeID *)cdataptr(cd) = id;
+  setcdataV(L, L->top-1, cd);
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_PUSH(top-7) LJLIB_SET(!)  /* Store reference to finalizer table. */
+
+LJLIB_CF(ffi_gc)	LJLIB_REC(.)
+{
+  GCcdata *cd = ffi_checkcdata(L, 1);
+  TValue *fin = lj_lib_checkany(L, 2);
+  CTState *cts = ctype_cts(L);
+  CType *ct = ctype_raw(cts, cd->ctypeid);
+  if (!(ctype_isptr(ct->info) || ctype_isstruct(ct->info) ||
+	ctype_isrefarray(ct->info)))
+    lj_err_arg(L, 1, LJ_ERR_FFI_INVTYPE);
+  lj_cdata_setfin(L, cd, gcval(fin), itype(fin));
+  L->top = L->base+1;  /* Pass through the cdata object. */
+  return 1;
+}
+
+LJLIB_PUSH(top-5) LJLIB_SET(!)  /* Store clib metatable in func environment. */
+
+LJLIB_CF(ffi_load)
+{
+  GCstr *name = lj_lib_checkstr(L, 1);
+  int global = (L->base+1 < L->top && tvistruecond(L->base+1));
+  lj_clib_load(L, tabref(curr_func(L)->c.env), name, global);
+  return 1;
+}
+
+LJLIB_PUSH(top-4) LJLIB_SET(C)
+LJLIB_PUSH(top-3) LJLIB_SET(os)
+LJLIB_PUSH(top-2) LJLIB_SET(arch)
+
+#include "lj_libdef.h"
+
+/* ------------------------------------------------------------------------ */
+
+/* Create special weak-keyed finalizer table. */
+static GCtab *ffi_finalizer(lua_State *L)
+{
+  /* NOBARRIER: The table is new (marked white). */
+  GCtab *t = lj_tab_new(L, 0, 1);
+  settabV(L, L->top++, t);
+  setgcref(t->metatable, obj2gco(t));
+  setstrV(L, lj_tab_setstr(L, t, lj_str_newlit(L, "__mode")),
+	  lj_str_newlit(L, "k"));
+  t->nomm = (uint8_t)(~(1u<<MM_mode));
+  return t;
+}
+
+/* Register FFI module as loaded. */
+static void ffi_register_module(lua_State *L)
+{
+  cTValue *tmp = lj_tab_getstr(tabV(registry(L)), lj_str_newlit(L, "_LOADED"));
+  if (tmp && tvistab(tmp)) {
+    GCtab *t = tabV(tmp);
+    copyTV(L, lj_tab_setstr(L, t, lj_str_newlit(L, LUA_FFILIBNAME)), L->top-1);
+    lj_gc_anybarriert(L, t);
+  }
+}
+
+LUALIB_API int luaopen_ffi(lua_State *L)
+{
+  CTState *cts = lj_ctype_init(L);
+  settabV(L, L->top++, (cts->miscmap = lj_tab_new(L, 0, 1)));
+  cts->finalizer = ffi_finalizer(L);
+  LJ_LIB_REG(L, NULL, ffi_meta);
+  /* NOBARRIER: basemt is a GC root. */
+  setgcref(basemt_it(G(L), LJ_TCDATA), obj2gco(tabV(L->top-1)));
+  LJ_LIB_REG(L, NULL, ffi_clib);
+  LJ_LIB_REG(L, NULL, ffi_callback);
+  /* NOBARRIER: the key is new and lj_tab_newkey() handles the barrier. */
+  settabV(L, lj_tab_setstr(L, cts->miscmap, &cts->g->strempty), tabV(L->top-1));
+  L->top--;
+  lj_clib_default(L, tabV(L->top-1));  /* Create ffi.C default namespace. */
+  lua_pushliteral(L, LJ_OS_NAME);
+  lua_pushliteral(L, LJ_ARCH_NAME);
+  LJ_LIB_REG(L, NULL, ffi);  /* Note: no global "ffi" created! */
+  ffi_register_module(L);
+  return 1;
+}
+
+#endif