commit 89b59eee7386379e87200a86215fc6de91e49036
parent 166dd0261a0fc012808a6448a1c46030c8db4806
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 17 Aug 2011 17:26:23 -0300
bug: __newindex metamethod may not work if metatable is its own
metatable + luaV_settable does not create entry when there is a
metamethod (and therefore entry is useless)
Diffstat:
4 files changed, 44 insertions(+), 26 deletions(-)
diff --git a/lapi.c b/lapi.c
@@ -1,5 +1,5 @@
/*
-** $Id: lapi.c,v 2.149 2011/06/13 14:13:06 roberto Exp roberto $
+** $Id: lapi.c,v 2.150 2011/08/09 20:58:29 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@@ -732,6 +732,7 @@ LUA_API void lua_rawset (lua_State *L, int idx) {
t = index2addr(L, idx);
api_check(L, ttistable(t), "table expected");
setobj2t(L, luaH_set(L, hvalue(t), L->top-2), L->top-1);
+ invalidateTMcache(hvalue(t));
luaC_barrierback(L, gcvalue(t), L->top-1);
L->top -= 2;
lua_unlock(L);
diff --git a/ltable.c b/ltable.c
@@ -1,5 +1,5 @@
/*
-** $Id: ltable.c,v 2.60 2011/06/16 14:14:31 roberto Exp roberto $
+** $Id: ltable.c,v 2.61 2011/08/09 20:58:29 roberto Exp roberto $
** Lua tables (hash)
** See Copyright Notice in lua.h
*/
@@ -322,8 +322,11 @@ void luaH_resize (lua_State *L, Table *t, int nasize, int nhsize) {
/* re-insert elements from hash part */
for (i = twoto(oldhsize) - 1; i >= 0; i--) {
Node *old = nold+i;
- if (!ttisnil(gval(old)))
+ if (!ttisnil(gval(old))) {
+ /* doesn't need barrier/invalidate cache, as entry was
+ already present in the table */
setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old));
+ }
}
if (!isdummy(nold))
luaM_freearray(L, nold, twoto(oldhsize)); /* free old array */
@@ -398,14 +401,18 @@ static Node *getfreepos (Table *t) {
** put new key in its main position; otherwise (colliding node is in its main
** position), new key goes to an empty position.
*/
-static TValue *newkey (lua_State *L, Table *t, const TValue *key) {
+TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
Node *mp = mainposition(t, key);
+ if (ttisnil(key)) luaG_runerror(L, "table index is nil");
+ else if (ttisnumber(key) && luai_numisnan(L, nvalue(key)))
+ luaG_runerror(L, "table index is NaN");
if (!ttisnil(gval(mp)) || isdummy(mp)) { /* main position is taken? */
Node *othern;
Node *n = getfreepos(t); /* get a free place */
if (n == NULL) { /* cannot find a free place? */
rehash(L, t, key); /* grow table */
- return luaH_set(L, t, key); /* re-insert key into grown table */
+ /* whatever called 'newkey' take care of TM cache and GC barrier */
+ return luaH_set(L, t, key); /* insert key into grown table */
}
lua_assert(!isdummy(n));
othern = mainposition(t, gkey(mp));
@@ -493,17 +500,15 @@ const TValue *luaH_get (Table *t, const TValue *key) {
}
+/*
+** beware: when using this function you probably need to check a GC
+** barrier and invalidate the TM cache.
+*/
TValue *luaH_set (lua_State *L, Table *t, const TValue *key) {
const TValue *p = luaH_get(t, key);
- t->flags = 0;
if (p != luaO_nilobject)
return cast(TValue *, p);
- else {
- if (ttisnil(key)) luaG_runerror(L, "table index is nil");
- else if (ttisnumber(key) && luai_numisnan(L, nvalue(key)))
- luaG_runerror(L, "table index is NaN");
- return newkey(L, t, key);
- }
+ else return luaH_newkey(L, t, key);
}
@@ -515,7 +520,7 @@ void luaH_setint (lua_State *L, Table *t, int key, TValue *value) {
else {
TValue k;
setnvalue(&k, cast_num(key));
- cell = newkey(L, t, &k);
+ cell = luaH_newkey(L, t, &k);
}
setobj2t(L, cell, value);
}
diff --git a/ltable.h b/ltable.h
@@ -1,5 +1,5 @@
/*
-** $Id: ltable.h,v 2.14 2010/06/25 12:18:10 roberto Exp roberto $
+** $Id: ltable.h,v 2.15 2011/08/09 20:58:29 roberto Exp roberto $
** Lua tables (hash)
** See Copyright Notice in lua.h
*/
@@ -15,11 +15,14 @@
#define gval(n) (&(n)->i_val)
#define gnext(n) ((n)->i_key.nk.next)
+#define invalidateTMcache(t) ((t)->flags = 0)
+
LUAI_FUNC const TValue *luaH_getint (Table *t, int key);
LUAI_FUNC void luaH_setint (lua_State *L, Table *t, int key, TValue *value);
LUAI_FUNC const TValue *luaH_getstr (Table *t, TString *key);
LUAI_FUNC const TValue *luaH_get (Table *t, const TValue *key);
+LUAI_FUNC TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key);
LUAI_FUNC TValue *luaH_set (lua_State *L, Table *t, const TValue *key);
LUAI_FUNC Table *luaH_new (lua_State *L);
LUAI_FUNC void luaH_resize (lua_State *L, Table *t, int nasize, int nhsize);
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 2.141 2011/06/09 18:24:22 roberto Exp roberto $
+** $Id: lvm.c,v 2.142 2011/08/09 20:58:29 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -127,29 +127,38 @@ void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
int loop;
- TValue temp;
for (loop = 0; loop < MAXTAGLOOP; loop++) {
const TValue *tm;
if (ttistable(t)) { /* `t' is a table? */
Table *h = hvalue(t);
- TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
- if (!ttisnil(oldval) || /* result is not nil? */
- (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
- setobj2t(L, oldval, val);
+ TValue *oldval = cast(TValue *, luaH_get(h, key));
+ /* if previous value is not nil, there must be a previous entry
+ in the table; moreover, a metamethod has no relevance */
+ if (!ttisnil(oldval) ||
+ /* previous value is nil; must check the metamethod */
+ ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
+ /* no metamethod; is there a previous entry in the table? */
+ (oldval != luaO_nilobject ||
+ /* no previous entry; must create one. (The next test is
+ always true; we only need the assignment.) */
+ (oldval = luaH_newkey(L, h, key), 1)))) {
+ /* no metamethod and (now) there is an entry with given key */
+ setobj2t(L, oldval, val); /* assign new value to that entry */
+ invalidateTMcache(h);
luaC_barrierback(L, obj2gco(h), val);
return;
}
- /* else will try the tag method */
+ /* else will try the metamethod */
}
- else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
- luaG_typeerror(L, t, "index");
+ else /* not a table; check metamethod */
+ if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
+ luaG_typeerror(L, t, "index");
+ /* there is a metamethod */
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val, 0);
return;
}
- /* else repeat with 'tm' */
- setobj(L, &temp, tm); /* avoid pointing inside table (may rehash) */
- t = &temp;
+ t = tm; /* else repeat with 'tm' */
}
luaG_runerror(L, "loop in settable");
}
