From 6048c4f74d7d63d6c2f5a53cd8e4ee01f6702be9 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 7 Mar 2001 15:09:25 -0300
Subject: [PATCH] better way to link callinfo's and stack

---
 lapi.c     |  22 +++----
 ldblib.c   |   4 +-
 ldebug.c   | 174 +++++++++++++++++++++++------------------------------
 ldo.c      |  47 ++++++---------
 ldo.h      |   4 +-
 lgc.c      |   9 +--
 lobject.h  |  22 +++----
 lstate.c   |   4 +-
 lstate.h   |  11 ++--
 luadebug.h |   4 +-
 lvm.c      |  16 ++---
 11 files changed, 138 insertions(+), 179 deletions(-)

diff --git a/lapi.c b/lapi.c
index 87131794..aa628469 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 1.134 2001/02/23 17:28:12 roberto Exp roberto $
+** $Id: lapi.c,v 1.135 2001/03/02 17:27:50 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -31,7 +31,7 @@ const l_char lua_ident[] = l_s("$Lua: ") LUA_VERSION l_s(" ")
 #define api_check(L, o)		/* nothing */
 #endif
 
-#define api_checknelems(L, n)	api_check(L, (n) <= (L->top - L->Cbase))
+#define api_checknelems(L, n)	api_check(L, (n) <= (L->top - L->ci->base))
 
 #define api_incr_top(L)	incr_top
 
@@ -39,11 +39,11 @@ const l_char lua_ident[] = l_s("$Lua: ") LUA_VERSION l_s(" ")
 
 TObject *luaA_index (lua_State *L, int index) {
   if (index > 0) {
-    api_check(L, index <= L->top - L->Cbase);
-    return L->Cbase+index-1;
+    api_check(L, index <= L->top - L->ci->base);
+    return L->ci->base+index-1;
   }
   else {
-    api_check(L, index != 0 && -index <= L->top - L->Cbase);
+    api_check(L, index != 0 && -index <= L->top - L->ci->base);
     return L->top+index;
   }
 }
@@ -51,13 +51,13 @@ TObject *luaA_index (lua_State *L, int index) {
 
 static TObject *luaA_indexAcceptable (lua_State *L, int index) {
   if (index > 0) {
-    TObject *o = L->Cbase+(index-1);
-    api_check(L, index <= L->stack_last - L->Cbase);
+    TObject *o = L->ci->base+(index-1);
+    api_check(L, index <= L->stack_last - L->ci->base);
     if (o >= L->top) return NULL;
     else return o;
   }
   else {
-    api_check(L, index != 0 && -index <= L->top - L->Cbase);
+    api_check(L, index != 0 && -index <= L->top - L->ci->base);
     return L->top+index;
   }
 }
@@ -86,7 +86,7 @@ LUA_API int lua_stackspace (lua_State *L) {
 LUA_API int lua_gettop (lua_State *L) {
   int i;
   lua_lock(L);
-  i = (L->top - L->Cbase);
+  i = (L->top - L->ci->base);
   lua_unlock(L);
   return i;
 }
@@ -95,9 +95,9 @@ LUA_API int lua_gettop (lua_State *L) {
 LUA_API void lua_settop (lua_State *L, int index) {
   lua_lock(L);
   if (index >= 0)
-    luaD_adjusttop(L, L->Cbase, index);
+    luaD_adjusttop(L, L->ci->base, index);
   else {
-    api_check(L, -(index+1) <= (L->top - L->Cbase));
+    api_check(L, -(index+1) <= (L->top - L->ci->base));
     L->top = L->top+index+1;  /* index is negative */
   }
   lua_unlock(L);
diff --git a/ldblib.c b/ldblib.c
index 9bdbe5d2..98faf5a7 100644
--- a/ldblib.c
+++ b/ldblib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldblib.c,v 1.33 2001/02/23 17:17:25 roberto Exp roberto $
+** $Id: ldblib.c,v 1.34 2001/03/06 20:09:38 roberto Exp roberto $
 ** Interface from Lua to its debug API
 ** See Copyright Notice in lua.h
 */
@@ -121,7 +121,7 @@ static void hookf (lua_State *L, void *key) {
   lua_pushuserdata(L, key);
   lua_gettable(L, -2);
   if (lua_isfunction(L, -1)) {
-    lua_pushvalue(L, 1);
+    lua_pushvalue(L, -3);  /* original argument (below table and function) */
     lua_rawcall(L, 1, 0);
   }
   else
diff --git a/ldebug.c b/ldebug.c
index ea11cefd..c3bf8756 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 1.72 2001/03/06 14:46:54 roberto Exp roberto $
+** $Id: ldebug.c,v 1.73 2001/03/07 13:22:55 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -24,19 +24,14 @@
 
 
 
-static const l_char *getfuncname (lua_State *L, StkId f, const l_char **name);
+static const l_char *getfuncname (lua_State *L, CallInfo *ci,
+                                  const l_char **name);
 
 
-static void setnormalized (TObject *d, const TObject *s) {
-  if (ttype(s) == LUA_TMARK) {
-    setclvalue(d, infovalue(s)->func);
-  }
-  else setobj(d, s);
-}
 
-
-static int isLmark (StkId o) {
-  return (o && ttype(o) == LUA_TMARK && !infovalue(o)->func->isC);
+static int isLmark (CallInfo *ci) {
+  lua_assert(ci == NULL || ttype(ci->base - 1) == LUA_TFUNCTION);
+  return (ci && ci->prev && !ci_func(ci)->isC);
 }
 
 
@@ -60,27 +55,25 @@ LUA_API lua_Hook lua_setlinehook (lua_State *L, lua_Hook func) {
 }
 
 
-static StkId aux_stackedfunction (lua_State *L, int level, StkId top) {
-  int i;
-  for (i = (top-1) - L->stack; i>=0; i--) {
-    if (is_T_MARK(&L->stack[i])) {
-      if (level == 0)
-        return L->stack+i;
-      level--;
-    }
-  }
-  return NULL;
+static CallInfo *ci_stack (lua_State *L, StkId obj) {
+  CallInfo *ci = L->ci;
+  while (ci->base > obj) ci = ci->prev;
+  return (ci != &L->basefunc) ? ci : NULL;
 }
 
 
 LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
-  StkId f;
+  CallInfo *ci;
   int status;
   lua_lock(L);
-  f = aux_stackedfunction(L, level, L->top);
-  if (f == NULL) status = 0;  /* there is no such level */
+  ci = L->ci;
+  while (level-- && ci != &L->basefunc) {
+    lua_assert(ci->base > ci->prev->base);
+    ci = ci->prev;
+  }
+  if (ci == &L->basefunc) status = 0;  /* there is no such level */
   else {
-    ar->_func = f;
+    ar->_ci = ci;
     status = 1;
   }
   lua_unlock(L);
@@ -88,18 +81,6 @@ LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
 }
 
 
-static int nups (StkId f) {
-  switch (ttype(f)) {
-    case LUA_TFUNCTION:
-      return clvalue(f)->nupvalues;
-    case LUA_TMARK:
-      return infovalue(f)->func->nupvalues;
-    default:
-      return 0;
-  }
-}
-
-
 int luaG_getline (int *lineinfo, int pc, int refline, int *prefi) {
   int refi;
   if (lineinfo == NULL || pc == -1)
@@ -131,45 +112,43 @@ int luaG_getline (int *lineinfo, int pc, int refline, int *prefi) {
 }
 
 
-static int currentpc (StkId f) {
-  CallInfo *ci = infovalue(f);
-  lua_assert(isLmark(f));
+static int currentpc (CallInfo *ci) {
+  lua_assert(isLmark(ci));
   if (ci->pc)
-    return (*ci->pc - ci->func->f.l->code) - 1;
+    return (*ci->pc - ci_func(ci)->f.l->code) - 1;
   else
     return -1;  /* function is not active */
 }
 
 
-static int currentline (StkId f) {
-  if (!isLmark(f))
+static int currentline (CallInfo *ci) {
+  if (!isLmark(ci))
     return -1;  /* only active lua functions have current-line information */
   else {
-    CallInfo *ci = infovalue(f);
-    int *lineinfo = ci->func->f.l->lineinfo;
-    return luaG_getline(lineinfo, currentpc(f), 1, NULL);
+    int *lineinfo = ci_func(ci)->f.l->lineinfo;
+    return luaG_getline(lineinfo, currentpc(ci), 1, NULL);
   }
 }
 
 
 
-static Proto *getluaproto (StkId f) {
-  return (isLmark(f) ?  infovalue(f)->func->f.l : NULL);
+static Proto *getluaproto (CallInfo *ci) {
+  return (isLmark(ci) ? ci_func(ci)->f.l : NULL);
 }
 
 
 LUA_API const l_char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
   const l_char *name;
-  StkId f;
+  CallInfo *ci;
   Proto *fp;
   lua_lock(L);
   name = NULL;
-  f = ar->_func;
-  fp = getluaproto(f);
-  if (fp) {  /* `f' is a Lua function? */
-    name = luaF_getlocalname(fp, n, currentpc(f));
+  ci = ar->_ci;
+  fp = getluaproto(ci);
+  if (fp) {  /* is a Lua function? */
+    name = luaF_getlocalname(fp, n, currentpc(ci));
     if (name)
-      luaA_pushobject(L, (f+1)+(n-1));  /* push value */
+      luaA_pushobject(L, ci->base+(n-1));  /* push value */
   }
   lua_unlock(L);
   return name;
@@ -178,19 +157,19 @@ LUA_API const l_char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
 
 LUA_API const l_char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
   const l_char *name;
-  StkId f;
+  CallInfo *ci;
   Proto *fp;
   lua_lock(L);
   name = NULL;
-  f = ar->_func;
-  fp = getluaproto(f);
+  ci = ar->_ci;
+  fp = getluaproto(ci);
   L->top--;  /* pop new value */
-  if (fp) {  /* `f' is a Lua function? */
-    name = luaF_getlocalname(fp, n, currentpc(f));
+  if (fp) {  /* is a Lua function? */
+    name = luaF_getlocalname(fp, n, currentpc(ci));
     if (!name || name[0] == l_c('('))  /* `(' starts private locals */
       name = NULL;
     else
-      setobj((f+1)+(n-1), L->top);
+      setobj(ci->base+(n-1), L->top);
   }
   lua_unlock(L);
   return name;
@@ -205,16 +184,12 @@ static void infoLproto (lua_Debug *ar, Proto *f) {
 
 
 static void funcinfo (lua_State *L, lua_Debug *ar, StkId func) {
-  Closure *cl = NULL;
-  switch (ttype(func)) {
-    case LUA_TFUNCTION:
-      cl = clvalue(func);
-      break;
-    case LUA_TMARK:
-      cl = infovalue(func)->func;
-      break;
-    default:
-      luaD_error(L, l_s("value for `lua_getinfo' is not a function"));
+  Closure *cl;
+  if (ttype(func) == LUA_TFUNCTION)
+    cl = clvalue(func);
+  else {
+    luaD_error(L, l_s("value for `lua_getinfo' is not a function"));
+    cl = NULL;  /* to avoid warnings */
   }
   if (cl->isC) {
     ar->source = l_s("=C");
@@ -255,60 +230,60 @@ static const l_char *travglobals (lua_State *L, const TObject *o) {
 }
 
 
-static void getname (lua_State *L, StkId f, lua_Debug *ar) {
-  TObject o;
-  setnormalized(&o, f);
+static void getname (lua_State *L, const TObject *f, lua_Debug *ar) {
   /* try to find a name for given function */
-  if ((ar->name = travglobals(L, &o)) != NULL)
+  if ((ar->name = travglobals(L, f)) != NULL)
     ar->namewhat = l_s("global");
   /* not found: try tag methods */
-  else if ((ar->name = travtagmethods(G(L), &o)) != NULL)
+  else if ((ar->name = travtagmethods(G(L), f)) != NULL)
     ar->namewhat = l_s("tag-method");
   else ar->namewhat = l_s("");  /* not found at all */
 }
 
 
 LUA_API int lua_getinfo (lua_State *L, const l_char *what, lua_Debug *ar) {
-  StkId func;
-  int isactive;
+  StkId f;
+  CallInfo *ci;
   int status = 1;
   lua_lock(L);
-  isactive = (*what != l_c('>'));
-  if (isactive)
-    func = ar->_func;
+  if (*what != l_c('>')) {  /* function is active? */
+    ci = ar->_ci;
+    f = ci->base - 1;
+  }
   else {
     what++;  /* skip the `>' */
-    func = L->top - 1;
+    ci = NULL;
+    f = L->top - 1;
   }
   for (; *what; what++) {
     switch (*what) {
       case l_c('S'): {
-        funcinfo(L, ar, func);
+        funcinfo(L, ar, f);
         break;
       }
       case l_c('l'): {
-        ar->currentline = currentline(func);
+        ar->currentline = currentline(ci);
         break;
       }
       case l_c('u'): {
-        ar->nups = nups(func);
+        ar->nups = (ttype(f) == LUA_TFUNCTION) ? clvalue(f)->nupvalues : 0;
         break;
       }
       case l_c('n'): {
-        ar->namewhat = (isactive) ? getfuncname(L, func, &ar->name) : NULL;
+        ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL;
         if (ar->namewhat == NULL)
-          getname(L, func, ar);
+          getname(L, f, ar);
         break;
       }
       case l_c('f'): {
-        setnormalized(L->top, func);
+        setobj(L->top, f);
         incr_top;  /* push function */
         break;
       }
       default: status = 0;  /* invalid option */
     }
   }
-  if (!isactive) L->top--;  /* pop function */
+  if (!ci) L->top--;  /* pop function */
   lua_unlock(L);
   return status;
 }
@@ -539,13 +514,13 @@ int luaG_checkcode (lua_State *L, const Proto *pt) {
 
 
 static const l_char *getobjname (lua_State *L, StkId obj, const l_char **name) {
-  StkId func = aux_stackedfunction(L, 0, obj);
-  if (!isLmark(func))
+  CallInfo *ci = ci_stack(L, obj);
+  if (!isLmark(ci))
     return NULL;  /* not an active Lua function */
   else {
-    Proto *p = infovalue(func)->func->f.l;
-    int pc = currentpc(func);
-    int stackpos = obj - (func+1);  /* func+1 == function base */
+    Proto *p = ci_func(ci)->f.l;
+    int pc = currentpc(ci);
+    int stackpos = obj - ci->base;
     Instruction i = luaG_symbexec(L, p, pc, stackpos);
     lua_assert(pc != -1);
     switch (GET_OPCODE(i)) {
@@ -570,18 +545,19 @@ static const l_char *getobjname (lua_State *L, StkId obj, const l_char **name) {
 }
 
 
-static const l_char *getfuncname (lua_State *L, StkId f, const l_char **name) {
-  StkId func = aux_stackedfunction(L, 0, f);  /* calling function */
-  if (!isLmark(func))
+static const l_char *getfuncname (lua_State *L, CallInfo *ci,
+                                  const l_char **name) {
+  ci = ci->prev;  /* calling function */
+  if (ci == &L->basefunc || !isLmark(ci))
     return NULL;  /* not an active Lua function */
   else {
-    Proto *p = infovalue(func)->func->f.l;
-    int pc = currentpc(func);
+    Proto *p = ci_func(ci)->f.l;
+    int pc = currentpc(ci);
     Instruction i;
     if (pc == -1) return NULL;  /* function is not activated */
     i = p->code[pc];
     return (GET_OPCODE(i) == OP_CALL
-             ? getobjname(L, (func+1)+GETARG_A(i), name)
+             ? getobjname(L, ci->base+GETARG_A(i), name)
              : NULL);  /* no useful name found */
   }
 }
diff --git a/ldo.c b/ldo.c
index fb6233be..95db67a3 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 1.129 2001/02/23 17:28:12 roberto Exp roberto $
+** $Id: ldo.c,v 1.130 2001/03/02 17:27:50 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -42,7 +42,7 @@ void luaD_init (lua_State *L, int stacksize) {
   stacksize += EXTRA_STACK;
   L->stack = luaM_newvector(L, stacksize, TObject);
   L->stacksize = stacksize;
-  L->Cbase = L->top = L->stack;
+  L->basefunc.base = L->top = L->stack;
   restore_stack_limit(L);
 }
 
@@ -90,8 +90,7 @@ static void luaD_openstack (lua_State *L, StkId pos) {
 
 
 static void dohook (lua_State *L, lua_Debug *ar, lua_Hook hook) {
-  StkId old_Cbase = L->Cbase;
-  StkId old_top = L->Cbase = L->top;
+  StkId old_top = L->top;
   luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
   L->allowhooks = 0;  /* cannot call hooks inside a hook */
   lua_unlock(L);
@@ -100,45 +99,41 @@ static void dohook (lua_State *L, lua_Debug *ar, lua_Hook hook) {
   lua_assert(L->allowhooks == 0);
   L->allowhooks = 1;
   L->top = old_top;
-  L->Cbase = old_Cbase;
 }
 
 
-void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook) {
+void luaD_lineHook (lua_State *L, int line, lua_Hook linehook) {
   if (L->allowhooks) {
     lua_Debug ar;
-    ar._func = func;
     ar.event = l_s("line");
+    ar._ci = L->ci;
     ar.currentline = line;
     dohook(L, &ar, linehook);
   }
 }
 
 
-static void luaD_callHook (lua_State *L, StkId func, lua_Hook callhook,
-                    const l_char *event) {
+static void luaD_callHook (lua_State *L, lua_Hook callhook,
+                           const l_char *event) {
   if (L->allowhooks) {
     lua_Debug ar;
-    ar._func = func;
     ar.event = event;
-    infovalue(func)->pc = NULL;  /* function is not active */
+    ar._ci = L->ci;
+    L->ci->pc = NULL;  /* function is not active */
     dohook(L, &ar, callhook);
   }
 }
 
 
-static StkId callCclosure (lua_State *L, const struct Closure *cl, StkId base) {
+static StkId callCclosure (lua_State *L, const struct Closure *cl) {
   int nup = cl->nupvalues;  /* number of upvalues */
-  StkId old_Cbase = L->Cbase;
   int n;
-  L->Cbase = base;       /* new base for C function */
   luaD_checkstack(L, nup+LUA_MINSTACK);  /* ensure minimum stack size */
   for (n=0; n<nup; n++)  /* copy upvalues as extra arguments */
     setobj(L->top++, &cl->upvalue[n]);
   lua_unlock(L);
   n = (*cl->f.c)(L);  /* do the actual call */
   lua_lock(L);
-  L->Cbase = old_Cbase;  /* restore old C base */
   return L->top - n;  /* return index of first result */
 }
 
@@ -154,7 +149,6 @@ void luaD_call (lua_State *L, StkId func, int nResults) {
   lua_Hook callhook;
   StkId firstResult;
   CallInfo ci;
-  Closure *cl;
   if (ttype(func) != LUA_TFUNCTION) {
     /* `func' is not a function; check the `function' tag method */
     Closure *tm = luaT_gettmbyObj(G(L), func, TM_FUNCTION);
@@ -163,18 +157,17 @@ void luaD_call (lua_State *L, StkId func, int nResults) {
     luaD_openstack(L, func);
     setclvalue(func, tm);  /* tag method is the new function to be called */
   }
-  cl = clvalue(func);
-  ci.func = cl;
-  setivalue(func, &ci);
+  ci.prev = L->ci;  /* chain new callinfo */
+  L->ci = &ci;
+  ci.base = func+1;
   callhook = L->callhook;
   if (callhook)
-    luaD_callHook(L, func, callhook, l_s("call"));
-  firstResult = (cl->isC ? callCclosure(L, cl, func+1) :
-                           luaV_execute(L, cl, func+1));
+    luaD_callHook(L, callhook, l_s("call"));
+  firstResult = (clvalue(func)->isC ? callCclosure(L, clvalue(func)) :
+                                      luaV_execute(L, clvalue(func), func+1));
   if (callhook)  /* same hook that was active at entry */
-    luaD_callHook(L, func, callhook, l_s("return"));
-  lua_assert(ttype(func) == LUA_TMARK);
-  setnilvalue(func);  /* remove callinfo from the stack */
+    luaD_callHook(L, callhook, l_s("return"));
+  L->ci = ci.prev;  /* unchain callinfo */
   /* move results to `func' (to erase parameters and function) */
   if (nResults == LUA_MULTRET) {
     while (firstResult < L->top)  /* copy all results */
@@ -368,7 +361,7 @@ void luaD_breakrun (lua_State *L, int errcode) {
 
 
 int luaD_runprotected (lua_State *L, void (*f)(lua_State *, void *), void *ud) {
-  StkId oldCbase = L->Cbase;
+  CallInfo *oldci = L->ci;
   StkId oldtop = L->top;
   struct lua_longjmp lj;
   int allowhooks = L->allowhooks;
@@ -379,7 +372,7 @@ int luaD_runprotected (lua_State *L, void (*f)(lua_State *, void *), void *ud) {
     (*f)(L, ud);
   else {  /* an error occurred: restore the state */
     L->allowhooks = allowhooks;
-    L->Cbase = oldCbase;
+    L->ci = oldci;
     L->top = oldtop;
     restore_stack_limit(L);
   }
diff --git a/ldo.h b/ldo.h
index b4bc94c5..bf8bbe7f 100644
--- a/ldo.h
+++ b/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 1.30 2001/02/07 18:13:49 roberto Exp roberto $
+** $Id: ldo.h,v 1.31 2001/02/23 17:17:25 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -21,7 +21,7 @@
 
 void luaD_init (lua_State *L, int stacksize);
 void luaD_adjusttop (lua_State *L, StkId base, int extra);
-void luaD_lineHook (lua_State *L, StkId func, int line, lua_Hook linehook);
+void luaD_lineHook (lua_State *L, int line, lua_Hook linehook);
 void luaD_call (lua_State *L, StkId func, int nResults);
 void luaD_checkstack (lua_State *L, int n);
 
diff --git a/lgc.c b/lgc.c
index ff4ccaf0..26aa51ff 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 1.92 2001/02/23 17:17:25 roberto Exp roberto $
+** $Id: lgc.c,v 1.93 2001/03/02 17:27:50 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -85,9 +85,6 @@ static void markobject (GCState *st, TObject *o) {
     case LUA_TUSERDATA:  case LUA_TSTRING:
       strmark(tsvalue(o));
       break;
-    case LUA_TMARK:
-      markclosure(st, infovalue(o)->func);
-      break;
     case LUA_TFUNCTION:
       markclosure(st, clvalue(o));
       break;
@@ -107,8 +104,8 @@ static void markstacks (lua_State *L, GCState *st) {
     marktable(st, L1->gt);  /* mark table of globals */
     for (o=L1->stack; o<L1->top; o++)
       markobject(st, o);
-    lim = (L1->stack_last - L1->top > MAXSTACK) ? L1->top+MAXSTACK
-                                              : L1->stack_last;
+    lim = (L1->stack_last - L1->ci->base > MAXSTACK) ? L1->ci->base+MAXSTACK
+                                                     : L1->stack_last;
     for (; o<=lim; o++) setnilvalue(o);
     lua_assert(L1->previous->next == L1 && L1->next->previous == L1);
     L1 = L1->next;
diff --git a/lobject.h b/lobject.h
index 16c3f53e..23ca0d03 100644
--- a/lobject.h
+++ b/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 1.99 2001/02/23 20:32:32 roberto Exp roberto $
+** $Id: lobject.h,v 1.100 2001/03/02 17:27:50 roberto Exp roberto $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -22,24 +22,15 @@
 #endif
 
 
-/* ttype for closures active in the stack */
-#define LUA_TMARK	6
-
 
 /* tags for values visible from Lua == first user-created tag */
 #define NUM_TAGS	6
 
 
-/* check whether `t' is a mark */
-#define is_T_MARK(t)	(ttype(t) == LUA_TMARK)
-
-
-
 typedef union {
   struct TString *ts;
   struct Closure *cl;
   struct Hash *h;
-  struct CallInfo *info;
   lua_Number n;		/* LUA_TNUMBER */
 } Value;
 
@@ -56,7 +47,6 @@ typedef struct lua_TObject {
 #define tsvalue(o)      ((o)->value.ts)
 #define clvalue(o)      ((o)->value.cl)
 #define hvalue(o)       ((o)->value.h)
-#define infovalue(o)	((o)->value.info)
 
 
 /* Macros to set values */
@@ -75,9 +65,6 @@ typedef struct lua_TObject {
 #define sethvalue(obj,x) \
   { TObject *_o=(obj); _o->tt=LUA_TTABLE; _o->value.h=(x); }
 
-#define setivalue(obj,x) \
-  { TObject *_o=(obj); _o->tt=LUA_TMARK; _o->value.info=(x); }
-
 #define setnilvalue(obj) ((obj)->tt=LUA_TNIL)
 
 #define setobj(obj1,obj2) \
@@ -85,6 +72,8 @@ typedef struct lua_TObject {
     o1->tt=o2->tt; o1->value = o2->value; }
 
 
+typedef TObject *StkId;  /* index to stack elements */
+
 
 /*
 ** String headers for string table
@@ -209,13 +198,16 @@ typedef struct Hash {
 ** informations about a call (for debugging)
 */
 typedef struct CallInfo {
-  struct Closure *func;  /* function being called */
+  struct CallInfo *prev;  /* linked list */
+  StkId base;  /* base for called function */
   const Instruction **pc;  /* current pc of called function */
   int lastpc;  /* last pc traced */
   int line;  /* current line */
   int refi;  /* current index in `lineinfo' */
 } CallInfo;
 
+#define ci_func(ci)	(clvalue((ci)->base - 1))
+
 
 extern const TObject luaO_nilobject;
 
diff --git a/lstate.c b/lstate.c
index 2b16a4eb..f48f59e3 100644
--- a/lstate.c
+++ b/lstate.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.c,v 1.57 2001/02/23 17:17:25 roberto Exp roberto $
+** $Id: lstate.c,v 1.58 2001/03/02 17:27:50 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -99,6 +99,8 @@ LUA_API lua_State *lua_open (lua_State *OL, int stacksize) {
     L->G = NULL;
     L->stack = NULL;
     L->stacksize = 0;
+    L->ci = &L->basefunc;
+    L->basefunc.prev = NULL;
     L->errorJmp = NULL;
     L->callhook = NULL;
     L->linehook = NULL;
diff --git a/lstate.h b/lstate.h
index 21348211..69fd02ad 100644
--- a/lstate.h
+++ b/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 1.53 2001/02/23 20:30:01 roberto Exp roberto $
+** $Id: lstate.h,v 1.54 2001/03/02 17:27:50 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -31,8 +31,6 @@
 #define LUA_USERSTATE
 #endif
 
-typedef TObject *StkId;  /* index to stack elements */
-
 
 /*
 ** marks for Reference array
@@ -90,18 +88,19 @@ typedef struct global_State {
 struct lua_State {
   LUA_USERSTATE
   StkId top;  /* first free slot in the stack */
-  StkId stack;  /* stack base */
+  CallInfo *ci;  /* call info for current function */
   StkId stack_last;  /* last free slot in the stack */
-  int stacksize;
-  StkId Cbase;  /* base for current C function */
   Hash *gt;  /* table for globals */
   global_State *G;
+  StkId stack;  /* stack base */
+  int stacksize;
   lua_Hook callhook;
   lua_Hook linehook;
   int allowhooks;
   struct lua_longjmp *errorJmp;  /* current error recover point */
   lua_State *next;  /* circular double linked list of states */
   lua_State *previous;
+  CallInfo basefunc;
 };
 
 
diff --git a/luadebug.h b/luadebug.h
index 5ffdbe03..f23216c5 100644
--- a/luadebug.h
+++ b/luadebug.h
@@ -1,5 +1,5 @@
 /*
-** $Id: luadebug.h,v 1.17 2000/10/30 12:38:50 roberto Exp roberto $
+** $Id: luadebug.h,v 1.18 2001/02/23 17:17:25 roberto Exp roberto $
 ** Debugging API
 ** See Copyright Notice in lua.h
 */
@@ -39,7 +39,7 @@ struct lua_Debug {
   const l_char *source;    /* (S) */
   l_char short_src[LUA_IDSIZE]; /* (S) */
   /* private part */
-  struct lua_TObject *_func;  /* active function */
+  struct CallInfo *_ci;  /* active function */
 };
 
 
diff --git a/lvm.c b/lvm.c
index 99405763..a8f0dc9f 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 1.173 2001/02/23 20:30:52 roberto Exp roberto $
+** $Id: lvm.c,v 1.174 2001/03/07 13:22:55 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -51,10 +51,10 @@ int luaV_tostring (lua_State *L, TObject *obj) {  /* LUA_NUMBER */
 }
 
 
-static void traceexec (lua_State *L, StkId base, lua_Hook linehook) {
-  CallInfo *ci = infovalue(base-1);
-  int *lineinfo = ci->func->f.l->lineinfo;
-  int pc = (*ci->pc - ci->func->f.l->code) - 1;
+static void traceexec (lua_State *L, lua_Hook linehook) {
+  CallInfo *ci = L->ci;
+  int *lineinfo = ci_func(ci)->f.l->lineinfo;
+  int pc = (*ci->pc - ci_func(ci)->f.l->code) - 1;
   int newline;
   if (pc == 0) {  /* may be first time? */
     ci->line = 1;
@@ -65,7 +65,7 @@ static void traceexec (lua_State *L, StkId base, lua_Hook linehook) {
   /* calls linehook when enters a new line or jumps back (loop) */
   if (newline != ci->line || pc <= ci->lastpc) {
     ci->line = newline;
-    luaD_lineHook(L, base-2, newline, linehook);
+    luaD_lineHook(L, newline, linehook);
   }
   ci->lastpc = pc;
 }
@@ -332,7 +332,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
   const Instruction *pc = tf->code;
   TString **const kstr = tf->kstr;
   const lua_Hook linehook = L->linehook;
-  infovalue(base-1)->pc = &pc;
+  L->ci->pc = &pc;
   if (tf->is_vararg)  /* varargs? */
     adjust_varargs(L, base, tf->numparams);
   luaD_adjusttop(L, base, tf->maxstacksize);
@@ -342,7 +342,7 @@ StkId luaV_execute (lua_State *L, const Closure *cl, StkId base) {
     const Instruction i = *pc++;
     lua_assert(L->top == base+tf->maxstacksize);
     if (linehook)
-      traceexec(L, base, linehook);
+      traceexec(L, linehook);
     switch (GET_OPCODE(i)) {
       case OP_RETURN: {
         L->top = top;