FFI: Refactor ffi.gc()/__gc. Compile ffi.gc(cdata, nil), too.

src/lib_ffi.c

@@ -768,19 +768,11 @@ LJLIB_CF(ffi_gc)	LJLIB_REC(.)
   GCcdata *cd = ffi_checkcdata(L, 1);
   TValue *fin = lj_lib_checkany(L, 2);
   CTState *cts = ctype_cts(L);
-  GCtab *t = cts->finalizer;
   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);
-  if (gcref(t->metatable)) {  /* Update finalizer table, if still enabled. */
-    copyTV(L, lj_tab_set(L, t, L->base), fin);
-    lj_gc_anybarriert(L, t);
-    if (!tvisnil(fin))
-      cd->marked |= LJ_GC_CDATA_FIN;
-    else
-      cd->marked &= ~LJ_GC_CDATA_FIN;
-  }
+  lj_cdata_setfin(L, cd, gcval(fin), itype(fin));
   L->top = L->base+1;  /* Pass through the cdata object. */
   return 1;
 }

src/lj_cdata.c

@@ -75,21 +75,20 @@ void LJ_FASTCALL lj_cdata_free(global_State *g, GCcdata *cd)
   }
 }
 
-TValue * LJ_FASTCALL lj_cdata_setfin(lua_State *L, GCcdata *cd)
+void lj_cdata_setfin(lua_State *L, GCcdata *cd, GCobj *obj, uint32_t it)
 {
-  global_State *g = G(L);
-  GCtab *t = ctype_ctsG(g)->finalizer;
+  GCtab *t = ctype_ctsG(G(L))->finalizer;
   if (gcref(t->metatable)) {
     /* Add cdata to finalizer table, if still enabled. */
     TValue *tv, tmp;
     setcdataV(L, &tmp, cd);
     lj_gc_anybarriert(L, t);
     tv = lj_tab_set(L, t, &tmp);
-    cd->marked |= LJ_GC_CDATA_FIN;
-    return tv;
-  } else {
-    /* Otherwise return dummy TValue. */
-    return &g->tmptv;
+    setgcV(L, tv, obj, it);
+    if (!tvisnil(tv))
+      cd->marked |= LJ_GC_CDATA_FIN;
+    else
+      cd->marked &= ~LJ_GC_CDATA_FIN;
   }
 }
 

src/lj_cdata.h

@@ -62,7 +62,8 @@ LJ_FUNC GCcdata *lj_cdata_newv(lua_State *L, CTypeID id, CTSize sz,
 			       CTSize align);
 
 LJ_FUNC void LJ_FASTCALL lj_cdata_free(global_State *g, GCcdata *cd);
-LJ_FUNCA TValue * LJ_FASTCALL lj_cdata_setfin(lua_State *L, GCcdata *cd);
+LJ_FUNC void lj_cdata_setfin(lua_State *L, GCcdata *cd, GCobj *obj,
+			     uint32_t it);
 
 LJ_FUNC CType *lj_cdata_index(CTState *cts, GCcdata *cd, cTValue *key,
 			      uint8_t **pp, CTInfo *qual);

src/lj_crecord.c

@@ -863,21 +863,17 @@ again:
 }
 
 /* Record setting a finalizer. */
-static void crec_finalizer(jit_State *J, TRef trcd, cTValue *fin)
+static void crec_finalizer(jit_State *J, TRef trcd, TRef trfin, cTValue *fin)
 {
-  TRef trlo = lj_ir_call(J, IRCALL_lj_cdata_setfin, trcd);
-  TRef trhi = emitir(IRT(IR_ADD, IRT_P32), trlo, lj_ir_kint(J, 4));
-  if (LJ_BE) { TRef tmp = trlo; trlo = trhi; trhi = tmp; }
-  if (tvisfunc(fin)) {
-    emitir(IRT(IR_XSTORE, IRT_P32), trlo, lj_ir_kfunc(J, funcV(fin)));
-    emitir(IRTI(IR_XSTORE), trhi, lj_ir_kint(J, LJ_TFUNC));
-  } else if (tviscdata(fin)) {
-    emitir(IRT(IR_XSTORE, IRT_P32), trlo,
-	   lj_ir_kgc(J, obj2gco(cdataV(fin)), IRT_CDATA));
-    emitir(IRTI(IR_XSTORE), trhi, lj_ir_kint(J, LJ_TCDATA));
+  if (tvisgcv(fin)) {
+    if (!trfin) trfin = lj_ir_kptr(J, gcval(fin));
+  } else if (tvisnil(fin)) {
+    trfin = lj_ir_kptr(J, NULL);
   } else {
     lj_trace_err(J, LJ_TRERR_BADTYPE);
   }
+  lj_ir_call(J, IRCALL_lj_cdata_setfin, trcd,
+	     trfin, lj_ir_kint(J, (int32_t)itype(fin)));
   J->needsnap = 1;
 }
 
@@ -1001,7 +997,7 @@ static void crec_alloc(jit_State *J, RecordFFData *rd, CTypeID id)
   /* Handle __gc metamethod. */
   fin = lj_ctype_meta(cts, id, MM_gc);
   if (fin)
-    crec_finalizer(J, trcd, fin);
+    crec_finalizer(J, trcd, 0, fin);
 }
 
 /* Record argument conversions. */
@@ -1648,7 +1644,9 @@ void LJ_FASTCALL recff_ffi_xof(jit_State *J, RecordFFData *rd)
 void LJ_FASTCALL recff_ffi_gc(jit_State *J, RecordFFData *rd)
 {
   argv2cdata(J, J->base[0], &rd->argv[0]);
-  crec_finalizer(J, J->base[0], &rd->argv[1]);
+  if (!J->base[1])
+    lj_trace_err(J, LJ_TRERR_BADTYPE);
+  crec_finalizer(J, J->base[0], J->base[1], &rd->argv[1]);
 }
 
 /* -- 64 bit bit.* library functions -------------------------------------- */

src/lj_ircall.h

@@ -203,7 +203,7 @@ typedef struct CCallInfo {
   _(FFI,	lj_carith_powi64,	2,   N, I64, XA2_64|CCI_NOFPRCLOBBER) \
   _(FFI,	lj_carith_powu64,	2,   N, U64, XA2_64|CCI_NOFPRCLOBBER) \
   _(FFI,	lj_cdata_newv,		4,   S, CDATA, CCI_L) \
-  _(FFI,	lj_cdata_setfin,	2,  FN, P32, CCI_L) \
+  _(FFI,	lj_cdata_setfin,	4,   S, NIL, CCI_L) \
   _(FFI,	strlen,			1,   L, INTP, 0) \
   _(FFI,	memcpy,			3,   S, PTR, 0) \
   _(FFI,	memset,			3,   S, PTR, 0) \