From 1d5b885437286a307a77b5d12756d73d374efd54 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 20 Dec 2017 12:58:05 -0200
Subject: when running Lua code, there is no need to keep 'L->top' "correct";
 set it only when needed.

---
 ldebug.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

(limited to 'ldebug.c')

diff --git a/ldebug.c b/ldebug.c
index 11d2b6a7..80c19d31 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.148 2017/12/13 18:32:09 roberto Exp roberto $
+** $Id: ldebug.c,v 2.149 2017/12/15 13:07:10 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -189,14 +189,10 @@ static const char *upvalname (Proto *p, int uv) {
 
 static const char *findlocal (lua_State *L, CallInfo *ci, int n,
                               StkId *pos) {
-  const char *name = NULL;
-  StkId base;
-  if (isLua(ci)) {
-    base = ci->func + 1;
-    name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
-  }
-  else
-    base = ci->func + 1;
+  StkId base = ci->func + 1;
+  const char *name = (isLua(ci))
+                     ? luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci))
+                     : NULL;
   if (name == NULL) {  /* no 'standard' name? */
     StkId limit = (ci == L->ci) ? L->top : ci->next->func;
     if (limit - base >= n && n > 0)  /* is 'n' inside 'ci' stack? */
@@ -741,6 +737,8 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
   const char *msg;
   va_list argp;
   luaC_checkGC(L);  /* error message uses memory */
+  if (isLuacode(ci))
+    L->top = ci->top;  /* prepare top */
   va_start(argp, fmt);
   msg = luaO_pushvfstring(L, fmt, argp);  /* format message */
   va_end(argp);
@@ -764,6 +762,7 @@ static int changedline (Proto *p, int oldpc, int newpc) {
 
 
 void luaG_traceexec (lua_State *L) {
+  ptrdiff_t oldtop = savestack(L, L->top);
   CallInfo *ci = L->ci;
   lu_byte mask = L->hookmask;
   int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
@@ -775,6 +774,7 @@ void luaG_traceexec (lua_State *L) {
     ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
     return;  /* do not call hook again (VM yielded, so it did not move) */
   }
+  L->top = ci->top;  /* prepare top */
   if (counthook)
     luaD_hook(L, LUA_HOOKCOUNT, -1);  /* call count hook */
   if (mask & LUA_MASKLINE) {
@@ -789,6 +789,7 @@ void luaG_traceexec (lua_State *L) {
     }
     L->oldpc = npc;
   }
+  L->top = restorestack(L, oldtop);
   if (L->status == LUA_YIELD) {  /* did hook yield? */
     if (counthook)
       L->hookcount = 1;  /* undo decrement to zero */
-- 
cgit v1.2.3-55-g6feb