9873466312

Committed 10 Jul 2024 11:36AM UTC coverage: 92.772% (+0.03%) from 92.745%

Build # 9873466312

Build Type

push

github

Committed by

ligurio

Commit Message

FFI: Turn FFI finalizer table into a proper GC root.

Reported by Sergey Bronnikov.

(cherry picked from commit f5affaa6c)

Previous patch fixes the problem partially because the introduced
GC root may not exist at the start phase of the GC cycle. In that
case, the cdata finalizer table will be collected at the end of
the cycle. Access to the cdata finalizer table exhibits heap use
after free. The patch turns the finalizer table into a proper
GC root. Note, that finalizer table is created on the
initialization of the main Lua State instead of loading the FFI
library.

Sergey Bronnikov:
* added the description and the tests for the problem

Part of tarantool/tarantool#10199

Run Details

5674 of 6025 branches covered (94.17%)

Branch coverage included in aggregate %.

26 of 26 new or added lines in 5 files covered. (100.0%)

18 existing lines in 5 files now uncovered.

21653 of 23431 relevant lines covered (92.41%)

2941091.57 hits per line

Source File
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92.51

/src/lib_ffi.c

/*
** FFI library.
** Copyright (C) 2005-2017 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 = tabref(G(L)->gcroot[GCROOT_FFI_FIN]);
      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_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-7) 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_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"

/* ------------------------------------------------------------------------ */

/* 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)));
  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

tarantool / luajit / 9873466312

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