From 09840f8f324e6391de5d6f15a26e12691dbf4b86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petri=20H=C3=A4kkinen?= <petrih@rmd.remedy.fi>
Date: Tue, 7 Nov 2023 11:20:54 +0200
Subject: [PATCH] Add lightuserdatatag macro

---
 VM/src/lapi.cpp       | 4 ++--
 VM/src/lobject.cpp    | 4 ++--
 VM/src/lobject.h      | 2 ++
 VM/src/ltm.cpp        | 2 +-
 VM/src/lvmexecute.cpp | 4 ++--
 VM/src/lvmutils.cpp   | 2 +-
 6 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/VM/src/lapi.cpp b/VM/src/lapi.cpp
index 63babca2..2b9d9849 100644
--- a/VM/src/lapi.cpp
+++ b/VM/src/lapi.cpp
@@ -508,7 +508,7 @@ void* lua_tolightuserdata(lua_State* L, int idx)
 void* lua_tolightuserdatatagged(lua_State* L, int idx, int tag)
 {
     StkId o = index2addr(L, idx);
-    return (!ttislightuserdata(o) || o->extra[0] != tag) ? NULL : pvalue(o);
+    return (!ttislightuserdata(o) || lightuserdatatag(o) != tag) ? NULL : pvalue(o);
 }
 
 void* lua_touserdata(lua_State* L, int idx)
@@ -540,7 +540,7 @@ int lua_lightuserdatatag(lua_State* L, int idx)
 {
     StkId o = index2addr(L, idx);
     if (ttislightuserdata(o))
-        return o->extra[0];
+        return lightuserdatatag(o);
     return -1;
 }
 
diff --git a/VM/src/lobject.cpp b/VM/src/lobject.cpp
index 8fb8b6b6..640bd96e 100644
--- a/VM/src/lobject.cpp
+++ b/VM/src/lobject.cpp
@@ -48,7 +48,7 @@ int luaO_rawequalObj(const TValue* t1, const TValue* t2)
         case LUA_TBOOLEAN:
             return bvalue(t1) == bvalue(t2); // boolean true must be 1 !!
         case LUA_TLIGHTUSERDATA:
-            return pvalue(t1) == pvalue(t2) && t1->extra[0] == t2->extra[0];
+            return pvalue(t1) == pvalue(t2) && lightuserdatatag(t1) == lightuserdatatag(t2);
         default:
             LUAU_ASSERT(iscollectable(t1));
             return gcvalue(t1) == gcvalue(t2);
@@ -71,7 +71,7 @@ int luaO_rawequalKey(const TKey* t1, const TValue* t2)
         case LUA_TBOOLEAN:
             return bvalue(t1) == bvalue(t2); // boolean true must be 1 !!
         case LUA_TLIGHTUSERDATA:
-            return pvalue(t1) == pvalue(t2) && t1->extra[0] == t2->extra[0];
+            return pvalue(t1) == pvalue(t2) && lightuserdatatag(t1) == lightuserdatatag(t2);
         default:
             LUAU_ASSERT(iscollectable(t1));
             return gcvalue(t1) == gcvalue(t2);
diff --git a/VM/src/lobject.h b/VM/src/lobject.h
index 71640140..eb2975ff 100644
--- a/VM/src/lobject.h
+++ b/VM/src/lobject.h
@@ -80,6 +80,8 @@ typedef struct lua_TValue
 
 #define l_isfalse(o) (ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0))
 
+#define lightuserdatatag(o) check_exp(ttislightuserdata(o), (o)->extra[0])
+
 /*
 ** for internal debug only
 */
diff --git a/VM/src/ltm.cpp b/VM/src/ltm.cpp
index 6ed42edd..a1838b6a 100644
--- a/VM/src/ltm.cpp
+++ b/VM/src/ltm.cpp
@@ -131,7 +131,7 @@ const TString* luaT_objtypenamestr(lua_State* L, const TValue* o)
     }
     else if (ttislightuserdata(o))
     {
-        const TString* name = L->global->lightuserdataname[o->extra[0]];
+        const TString* name = L->global->lightuserdataname[lightuserdatatag(o)];
 
         if (name)
             return name;
diff --git a/VM/src/lvmexecute.cpp b/VM/src/lvmexecute.cpp
index 6ae7a70b..7778bf56 100644
--- a/VM/src/lvmexecute.cpp
+++ b/VM/src/lvmexecute.cpp
@@ -1112,7 +1112,7 @@ reentry:
                         VM_NEXT();
 
                     case LUA_TLIGHTUSERDATA:
-                        pc += pvalue(ra) == pvalue(rb) && ra->extra[0] == rb->extra[0] ? LUAU_INSN_D(insn) : 1;
+                        pc += (pvalue(ra) == pvalue(rb) && lightuserdatatag(ra) == lightuserdatatag(rb)) ? LUAU_INSN_D(insn) : 1;
                         LUAU_ASSERT(unsigned(pc - cl->l.p->code) < unsigned(cl->l.p->sizecode));
                         VM_NEXT();
 
@@ -1227,7 +1227,7 @@ reentry:
                         VM_NEXT();
 
                     case LUA_TLIGHTUSERDATA:
-                        pc += pvalue(ra) != pvalue(rb) || ra->extra[0] != rb->extra[0] ? LUAU_INSN_D(insn) : 1;
+                        pc += (pvalue(ra) != pvalue(rb) || lightuserdatatag(ra) != lightuserdatatag(rb)) ? LUAU_INSN_D(insn) : 1;
                         LUAU_ASSERT(unsigned(pc - cl->l.p->code) < unsigned(cl->l.p->sizecode));
                         VM_NEXT();
 
diff --git a/VM/src/lvmutils.cpp b/VM/src/lvmutils.cpp
index 3985f199..ade8d694 100644
--- a/VM/src/lvmutils.cpp
+++ b/VM/src/lvmutils.cpp
@@ -288,7 +288,7 @@ int luaV_equalval(lua_State* L, const TValue* t1, const TValue* t2)
     case LUA_TBOOLEAN:
         return bvalue(t1) == bvalue(t2); // true must be 1 !!
     case LUA_TLIGHTUSERDATA:
-        return pvalue(t1) == pvalue(t2) && t1->extra[0] == t2->extra[0];
+        return pvalue(t1) == pvalue(t2) && lightuserdatatag(t1) == lightuserdatatag(t2);
     case LUA_TUSERDATA:
     {
         tm = get_compTM(L, uvalue(t1)->metatable, uvalue(t2)->metatable, TM_EQ);