lua

commit f055a9dffd9ba403a99266a662b9992bc89dcaa1
parent 4a7fe61806b266d895c0d2a4725dc427315022bb
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date:   Sun, 25 Feb 2018 09:43:25 -0300

added check in 'obj2gco' to prevent its use in non Lua-object pointers
(otherwise its cast is blind, casting any value given to it)

Diffstat:
M
lstate.h
 | 
9
++++++---

1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 2.155 2018/02/15 18:06:24 roberto Exp roberto $
+** $Id: lstate.h,v 2.156 2018/02/17 19:29:29 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -252,8 +252,11 @@ union GCUnion {
 #define gco2upv(o)  check_exp((o)->tt == LUA_TUPVAL, &((cast_u(o))->upv))
 
 
-/* macro to convert a Lua object into a GCObject */
-#define obj2gco(v)	(&(cast_u(v)->gc))
+/*
+** macro to convert a Lua object into a GCObject
+** (The access to 'tt' tries to ensure that 'v' is actually a Lua object.)
+*/
+#define obj2gco(v)	check_exp((v)->tt >= LUA_TSTRING, &(cast_u(v)->gc))
 
 
 /* actual number of total bytes allocated */