FFI: Record loads/stores to external variables in namespaces.

doc/ext_ffi_semantics.html

@@ -991,7 +991,6 @@ value.</li>
 <li>Calls to ctype metamethods which are not plain functions.</li>
 <li>ctype <tt>__newindex</tt> tables and non-string lookups in ctype
 <tt>__index</tt> tables.</li>
-<li>Accesses to external variables in C&nbsp;library namespaces.</li>
 <li><tt>tostring()</tt> for cdata types.</li>
 <li>Calls to the following <a href="ext_ffi_api.html">ffi.* API</a>
 functions: <tt>cdef</tt>, <tt>load</tt>, <tt>typeof</tt>,

src/lib_ffi.c

@@ -325,7 +325,7 @@ static TValue *ffi_clib_index(lua_State *L)
   return lj_clib_index(L, cl, strV(o+1));
 }
 
-LJLIB_CF(ffi_clib___index)	LJLIB_REC(clib_index)
+LJLIB_CF(ffi_clib___index)	LJLIB_REC(clib_index 1)
 {
   TValue *tv = ffi_clib_index(L);
   if (tviscdata(tv)) {
@@ -335,7 +335,9 @@ LJLIB_CF(ffi_clib___index)	LJLIB_REC(clib_index)
     if (ctype_isextern(s->info)) {
       CTypeID sid = ctype_cid(s->info);
       void *sp = *(void **)cdataptr(cd);
-      if (lj_cconv_tv_ct(cts, ctype_raw(cts, sid), sid, L->top-1, sp))
+      CType *ct = ctype_raw(cts, sid);
+      if (ctype_isenum(ct->info)) ct = ctype_child(cts, ct);
+      if (lj_cconv_tv_ct(cts, ct, sid, L->top-1, sp))
 	lj_gc_check(L);
       return 1;
     }
@@ -344,7 +346,7 @@ LJLIB_CF(ffi_clib___index)	LJLIB_REC(clib_index)
   return 1;
 }
 
-LJLIB_CF(ffi_clib___newindex)
+LJLIB_CF(ffi_clib___newindex)	LJLIB_REC(clib_index 0)
 {
   TValue *tv = ffi_clib_index(L);
   TValue *o = L->base+2;

src/lj_crecord.c

@@ -1031,6 +1031,7 @@ void LJ_FASTCALL recff_clib_index(jit_State *J, RecordFFData *rd)
     CType *ct;
     CTypeID id = lj_ctype_getname(cts, &ct, name, CLNS_INDEX);
     cTValue *tv = lj_tab_getstr(cl->cache, name);
+    rd->nres = rd->data;
     if (id && tv && !tvisnil(tv)) {
       /* Specialize to the symbol name and make the result a constant. */
       emitir(IRTG(IR_EQ, IRT_STR), J->base[1], lj_ir_kstr(J, name));
@@ -1041,7 +1042,21 @@ void LJ_FASTCALL recff_clib_index(jit_State *J, RecordFFData *rd)
 	else
 	  J->base[0] = lj_ir_kint(J, (int32_t)ct->size);
       } else if (ctype_isextern(ct->info)) {
-	lj_trace_err(J, LJ_TRERR_BADTYPE);  /* NYI: access extern variables. */
+	CTypeID sid = ctype_cid(ct->info);
+	void *sp = *(void **)cdataptr(cdataV(tv));
+	TRef ptr;
+	ct = ctype_raw(cts, sid);
+	if (rd->data && ctype_isenum(ct->info)) ct = ctype_child(cts, ct);
+	if (LJ_64 && !checkptr32(sp))
+	  ptr = lj_ir_kintp(J, (uintptr_t)sp);
+	else
+	  ptr = lj_ir_kptr(J, sp);
+	if (rd->data) {
+	  J->base[0] = crec_tv_ct(J, ct, sid, ptr);
+	} else {
+	  J->needsnap = 1;
+	  crec_ct_tv(J, ct, ptr, J->base[2], &rd->argv[2]);
+	}
       } else {
 	J->base[0] = lj_ir_kgc(J, obj2gco(cdataV(tv)), IRT_CDATA);
       }