diff --git a/ldebug.c b/ldebug.c
index f9c30ce0..24e9aaca 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.85 2011/09/13 17:40:20 roberto Exp roberto $
+** $Id: ldebug.c,v 2.86 2011/09/13 18:05:59 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -520,7 +520,7 @@ void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
 }
 
 
-void luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
+l_noret luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
   TValue temp;
   if (luaV_tonumber(p1, &temp) == NULL)
     p2 = p1;  /* first operand is wrong */
@@ -528,14 +528,13 @@ void luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
 }
 
 
-int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
+l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
   const char *t1 = objtypename(p1);
   const char *t2 = objtypename(p2);
   if (t1 == t2)
     luaG_runerror(L, "attempt to compare two %s values", t1);
   else
     luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
-  return 0;
 }
 
 
@@ -555,7 +554,7 @@ static void addinfo (lua_State *L, const char *msg) {
 }
 
 
-void luaG_errormsg (lua_State *L) {
+l_noret luaG_errormsg (lua_State *L) {
   if (L->errfunc != 0) {  /* is there an error handling function? */
     StkId errfunc = restorestack(L, L->errfunc);
     if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
@@ -568,7 +567,7 @@ void luaG_errormsg (lua_State *L) {
 }
 
 
-void luaG_runerror (lua_State *L, const char *fmt, ...) {
+l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
   va_list argp;
   va_start(argp, fmt);
   addinfo(L, luaO_pushvfstring(L, fmt, argp));
diff --git a/ldebug.h b/ldebug.h
index 5f865ee8..7af551e2 100644
--- a/ldebug.h
+++ b/ldebug.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.h,v 2.5 2009/06/10 16:57:53 roberto Exp roberto $
+** $Id: ldebug.h,v 2.6 2011/06/02 19:31:40 roberto Exp roberto $
 ** Auxiliary functions from Debug Interface module
 ** See Copyright Notice in lua.h
 */
@@ -21,14 +21,14 @@
 #define ci_func(ci)		(clLvalue((ci)->func))
 
 
-LUAI_FUNC void luaG_typeerror (lua_State *L, const TValue *o,
-                                             const char *opname);
-LUAI_FUNC void luaG_concaterror (lua_State *L, StkId p1, StkId p2);
-LUAI_FUNC void luaG_aritherror (lua_State *L, const TValue *p1,
-                                              const TValue *p2);
-LUAI_FUNC int luaG_ordererror (lua_State *L, const TValue *p1,
-                                             const TValue *p2);
-LUAI_FUNC void luaG_runerror (lua_State *L, const char *fmt, ...);
-LUAI_FUNC void luaG_errormsg (lua_State *L);
+LUAI_FUNC l_noret luaG_typeerror (lua_State *L, const TValue *o,
+                                                const char *opname);
+LUAI_FUNC l_noret luaG_concaterror (lua_State *L, StkId p1, StkId p2);
+LUAI_FUNC l_noret luaG_aritherror (lua_State *L, const TValue *p1,
+                                                 const TValue *p2);
+LUAI_FUNC l_noret luaG_ordererror (lua_State *L, const TValue *p1,
+                                                 const TValue *p2);
+LUAI_FUNC l_noret luaG_runerror (lua_State *L, const char *fmt, ...);
+LUAI_FUNC l_noret luaG_errormsg (lua_State *L);
 
 #endif
diff --git a/ldo.c b/ldo.c
index b74efd31..ed9771e1 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.99 2011/08/23 17:24:34 roberto Exp roberto $
+** $Id: ldo.c,v 2.100 2011/09/12 20:33:03 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -100,7 +100,7 @@ static void seterrorobj (lua_State *L, int errcode, StkId oldtop) {
 }
 
 
-void luaD_throw (lua_State *L, int errcode) {
+l_noret luaD_throw (lua_State *L, int errcode) {
   if (L->errorJmp) {  /* thread has an error handler? */
     L->errorJmp->status = errcode;  /* set status */
     LUAI_THROW(L, L->errorJmp);  /* jump to it */
@@ -472,7 +472,7 @@ static int recover (lua_State *L, int status) {
 ** coroutine itself. (Such errors should not be handled by any coroutine
 ** error handler and should not kill the coroutine.)
 */
-static void resume_error (lua_State *L, const char *msg, StkId firstArg) {
+static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) {
   L->top = firstArg;  /* remove args from the stack */
   setsvalue2s(L, L->top, luaS_new(L, msg));  /* push error message */
   incr_top(L);
diff --git a/ldo.h b/ldo.h
index dd651040..2ff768db 100644
--- a/ldo.h
+++ b/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 2.17 2009/11/25 15:27:51 roberto Exp roberto $
+** $Id: ldo.h,v 2.18 2009/12/17 12:28:57 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -38,7 +38,7 @@ LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize);
 LUAI_FUNC void luaD_growstack (lua_State *L, int n);
 LUAI_FUNC void luaD_shrinkstack (lua_State *L);
 
-LUAI_FUNC void luaD_throw (lua_State *L, int errcode);
+LUAI_FUNC l_noret luaD_throw (lua_State *L, int errcode);
 LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud);
 
 #endif
diff --git a/llimits.h b/llimits.h
index d9445501..d0be3ab5 100644
--- a/llimits.h
+++ b/llimits.h
@@ -1,5 +1,5 @@
 /*
-** $Id: llimits.h,v 1.91 2011/09/13 17:39:23 roberto Exp roberto $
+** $Id: llimits.h,v 1.92 2011/09/30 12:46:06 roberto Exp roberto $
 ** Limits, basic types, and some other `installation-dependent' definitions
 ** See Copyright Notice in lua.h
 */
@@ -96,6 +96,19 @@ typedef LUAI_UACNUMBER l_uacNumber;
 #define cast_uchar(i)	cast(unsigned char, (i))
 
 
+/*
+** non-return type
+*/
+#if defined(__GNUC__)
+#define l_noret		void __attribute__((noreturn))
+#elif defined(_MSC_VER)
+#define l_noret		void __declspec(noreturn)
+#else
+#define l_noret		void
+#endif
+
+
+
 /*
 ** maximum depth for nested C calls and syntactical nested non-terminals
 ** in a program. (Value must fit in an unsigned short int.)
diff --git a/lvm.c b/lvm.c
index 5b816239..55bd8ec9 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.142 2011/08/09 20:58:29 roberto Exp roberto $
+** $Id: lvm.c,v 2.143 2011/08/17 20:26:47 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -226,9 +226,9 @@ int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
     return luai_numlt(L, nvalue(l), nvalue(r));
   else if (ttisstring(l) && ttisstring(r))
     return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
-  else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
-    return res;
-  return luaG_ordererror(L, l, r);
+  else if ((res = call_orderTM(L, l, r, TM_LT)) < 0)
+    luaG_ordererror(L, l, r);
+  return res;
 }
 
 
@@ -238,11 +238,11 @@ int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
     return luai_numle(L, nvalue(l), nvalue(r));
   else if (ttisstring(l) && ttisstring(r))
     return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
-  else if ((res = call_orderTM(L, l, r, TM_LE)) != -1)  /* first try `le' */
+  else if ((res = call_orderTM(L, l, r, TM_LE)) >= 0)  /* first try `le' */
     return res;
-  else if ((res = call_orderTM(L, r, l, TM_LT)) != -1)  /* else try `lt' */
-    return !res;
-  return luaG_ordererror(L, l, r);
+  else if ((res = call_orderTM(L, r, l, TM_LT)) < 0)  /* else try `lt' */
+    luaG_ordererror(L, l, r);
+  return !res;
 }