FFI: Properly unsink non-standard cdata allocations.

src/lib_ffi.c

@@ -505,10 +505,7 @@ LJLIB_CF(ffi_new)	LJLIB_REC(.)
   }
   if (sz == CTSIZE_INVALID)
     lj_err_arg(L, 1, LJ_ERR_FFI_INVSIZE);
-  if (!(info & CTF_VLA) && ctype_align(info) <= CT_MEMALIGN)
-    cd = lj_cdata_new(cts, id, sz);
-  else
-    cd = lj_cdata_newv(L, id, sz, ctype_align(info));
+  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. */

src/lj_cdata.c

@@ -49,6 +49,15 @@ GCcdata *lj_cdata_newv(lua_State *L, CTypeID id, CTSize sz, CTSize align)
   return cd;
 }
 
+/* Allocate arbitrary C data object. */
+GCcdata *lj_cdata_newx(CTState *cts, CTypeID id, CTSize sz, CTInfo info)
+{
+  if (!(info & CTF_VLA) && ctype_align(info) <= CT_MEMALIGN)
+    return lj_cdata_new(cts, id, sz);
+  else
+    return lj_cdata_newv(cts->L, id, sz, ctype_align(info));
+}
+
 /* Free a C data object. */
 void LJ_FASTCALL lj_cdata_free(global_State *g, GCcdata *cd)
 {

src/lj_cdata.h

@@ -60,6 +60,8 @@ static LJ_AINLINE GCcdata *lj_cdata_new_(lua_State *L, CTypeID id, CTSize sz)
 LJ_FUNC GCcdata *lj_cdata_newref(CTState *cts, const void *pp, CTypeID id);
 LJ_FUNC GCcdata *lj_cdata_newv(lua_State *L, CTypeID id, CTSize sz,
 			       CTSize align);
+LJ_FUNC GCcdata *lj_cdata_newx(CTState *cts, CTypeID id, CTSize sz,
+			       CTInfo info);
 
 LJ_FUNC void LJ_FASTCALL lj_cdata_free(global_State *g, GCcdata *cd);
 LJ_FUNC void lj_cdata_setfin(lua_State *L, GCcdata *cd, GCobj *obj,

src/lj_snap.c

@@ -711,8 +711,9 @@ static void snap_unsink(jit_State *J, GCtrace *T, ExitState *ex,
   if (ir->o == IR_CNEW || ir->o == IR_CNEWI) {
     CTState *cts = ctype_cts(J->L);
     CTypeID id = (CTypeID)T->ir[ir->op1].i;
-    CTSize sz = lj_ctype_size(cts, id);
-    GCcdata *cd = lj_cdata_new(cts, id, sz);
+    CTSize sz;
+    CTInfo info = lj_ctype_info(cts, id, &sz);
+    GCcdata *cd = lj_cdata_newx(cts, id, sz, info);
     setcdataV(J->L, o, cd);
     if (ir->o == IR_CNEWI) {
       uint8_t *p = (uint8_t *)cdataptr(cd);