From 43c8e5bded052801f54a7439d18933b83570eb82 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 30 Oct 2023 14:25:59 -0300
Subject: Full abstraction for representation of array values

---
 lgc.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

(limited to 'lgc.c')

diff --git a/lgc.c b/lgc.c
index a3094ff5..813b08d5 100644
--- a/lgc.c
+++ b/lgc.c
@@ -91,6 +91,13 @@
 #define gcvalueN(o)     (iscollectable(o) ? gcvalue(o) : NULL)
 
 
+/*
+** Access to collectable objects in array part of tables
+*/
+#define gcvalarr(t,i)  \
+	((*getArrTag(t,i) & BIT_ISCOLLECTABLE) ? getArrVal(t,i)->gc : NULL)
+
+
 #define markvalue(g,o) { checkliveness(g->mainthread,o); \
   if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); }
 
@@ -486,9 +493,10 @@ static int traverseephemeron (global_State *g, Table *h, int inv) {
   unsigned int nsize = sizenode(h);
   /* traverse array part */
   for (i = 0; i < asize; i++) {
-    if (valiswhite(&h->array[i])) {
+    GCObject *o = gcvalarr(h, i + 1);
+    if (o != NULL && iswhite(o)) {
       marked = 1;
-      reallymarkobject(g, gcvalue(&h->array[i]));
+      reallymarkobject(g, o);
     }
   }
   /* traverse hash part; if 'inv', traverse descending
@@ -524,8 +532,11 @@ static void traversestrongtable (global_State *g, Table *h) {
   Node *n, *limit = gnodelast(h);
   unsigned int i;
   unsigned int asize = luaH_realasize(h);
-  for (i = 0; i < asize; i++)  /* traverse array part */
-    markvalue(g, &h->array[i]);
+  for (i = 0; i < asize; i++) {  /* traverse array part */
+    GCObject *o = gcvalarr(h, i + 1);
+    if (o != NULL && iswhite(o))
+      reallymarkobject(g, o);
+  }
   for (n = gnode(h, 0); n < limit; n++) {  /* traverse hash part */
     if (isempty(gval(n)))  /* entry is empty? */
       clearkey(n);  /* clear its key */
@@ -746,9 +757,9 @@ static void clearbyvalues (global_State *g, GCObject *l, GCObject *f) {
     unsigned int i;
     unsigned int asize = luaH_realasize(h);
     for (i = 0; i < asize; i++) {
-      TValue *o = &h->array[i];
-      if (iscleared(g, gcvalueN(o)))  /* value was collected? */
-        setempty(o);  /* remove entry */
+      GCObject *o = gcvalarr(h, i + 1);
+      if (iscleared(g, o))  /* value was collected? */
+        *getArrTag(h, i + 1) = LUA_VEMPTY;  /* remove entry */
     }
     for (n = gnode(h, 0); n < limit; n++) {
       if (iscleared(g, gcvalueN(gval(n))))  /* unmarked value? */
-- 
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