11 files changed, 152 insertions, 127 deletions

diff --git a/lapi.c b/lapi.c
index 8d4d5e7d..6b6bc565 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.272 2017/11/01 18:20:48 roberto Exp roberto $
+** $Id: lapi.c,v 2.273 2017/11/02 11:28:56 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -10,6 +10,7 @@
 #include "lprefix.h"
 
 
+#include <limits.h>
 #include <stdarg.h>
 #include <string.h>
 
@@ -60,12 +61,12 @@ const char lua_ident[] =
 static TValue *index2value (lua_State *L, int idx) {
   if (idx > 0) {
     StkId o = L->func + idx;
-    api_check(L, idx <= L->ci->top - (L->func + 1), "unacceptable index");
+    api_check(L, idx < L->func->stkci.framesize, "unacceptable index");
     if (o >= L->top) return NONVALIDVALUE;
     else return s2v(o);
   }
   else if (!ispseudo(idx)) {  /* negative index */
-    api_check(L, idx != 0 && -idx <= L->top - (L->func + 1), "invalid index");
+    api_check(L, idx != 0 && -idx < L->func->stkci.framesize, "invalid index");
     return s2v(L->top + idx);
   }
   else if (idx == LUA_REGISTRYINDEX)
@@ -109,10 +110,12 @@ static void growstack (lua_State *L, void *ud) {
 
 LUA_API int lua_checkstack (lua_State *L, int n) {
   int res;
-  CallInfo *ci = L->ci;
+  int frameuse = L->top - L->func;
   lua_lock(L);
   api_check(L, n >= 0, "negative 'n'");
-  if (L->stack_last - L->top > n)  /* stack large enough? */
+  if (n >= USHRT_MAX - frameuse)
+    res = 0;  /* frame size overflow */
+  else if (L->stack_last - L->top > n)  /* stack large enough? */
     res = 1;  /* yes; check is OK */
   else {  /* no; need to grow stack */
     int inuse = cast_int(L->top - L->stack) + EXTRA_STACK;
@@ -121,8 +124,8 @@ LUA_API int lua_checkstack (lua_State *L, int n) {
     else  /* try to grow stack */
       res = (luaD_rawrunprotected(L, &growstack, &n) == LUA_OK);
   }
-  if (res && ci->top < L->top + n)
-    ci->top = L->top + n;  /* adjust frame top */
+  if (res && L->func->stkci.framesize < frameuse + n)
+    L->func->stkci.framesize = frameuse + n;  /* adjust frame size */
   lua_unlock(L);
   return res;
 }
@@ -134,7 +137,7 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
   lua_lock(to);
   api_checknelems(from, n);
   api_check(from, G(from) == G(to), "moving among independent states");
-  api_check(from, to->ci->top - to->top >= n, "stack overflow");
+  api_check(from, functop(to->func) - to->top >= n, "stack overflow");
   from->top -= n;
   for (i = 0; i < n; i++) {
     setobjs2s(to, to->top, from->top + i);
@@ -929,15 +932,16 @@ LUA_API void lua_setuservalue (lua_State *L, int idx) {
 
 
 #define checkresults(L,na,nr) \
-     api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \
-        "results from function overflow current stack size")
+     api_check(L, (nr) == LUA_MULTRET || \
+                  (functop(L->func) - L->top >= (nr) - (na)), \
+        "results from function overflow current frame size")
 
 
 LUA_API void lua_callk (lua_State *L, int nargs, int nresults,
                         lua_KContext ctx, lua_KFunction k) {
   StkId func;
   lua_lock(L);
-  api_check(L, k == NULL || !isLua(L->ci),
+  api_check(L, k == NULL || !isLua(L->func),
     "cannot use continuations inside hooks");
   api_checknelems(L, nargs+1);
   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
@@ -976,36 +980,37 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
                         lua_KContext ctx, lua_KFunction k) {
   struct CallS c;
   int status;
-  ptrdiff_t func;
+  ptrdiff_t efunc;
   lua_lock(L);
-  api_check(L, k == NULL || !isLua(L->ci),
+  api_check(L, k == NULL || !isLua(L->func),
     "cannot use continuations inside hooks");
   api_checknelems(L, nargs+1);
   api_check(L, L->status == LUA_OK, "cannot do calls on non-normal thread");
   checkresults(L, nargs, nresults);
   if (errfunc == 0)
-    func = 0;
+    efunc = 0;
   else {
     StkId o = index2stack(L, errfunc);
-    func = savestack(L, o);
+    efunc = savestack(L, o);
   }
   c.func = L->top - (nargs+1);  /* function to be called */
   if (k == NULL || L->nny > 0) {  /* no continuation or no yieldable? */
     c.nresults = nresults;  /* do a 'conventional' protected call */
-    status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func);
+    status = luaD_pcall(L, f_call, &c, savestack(L, c.func), efunc);
   }
   else {  /* prepare continuation (call is already protected by 'resume') */
     CallInfo *ci = L->ci;
+    StkId func = L->func;
     ci->u.c.k = k;  /* save continuation */
     ci->u.c.ctx = ctx;  /* save context */
     /* save information for error recovery */
     ci->u2.funcidx = savestack(L, c.func);
     ci->u.c.old_errfunc = L->errfunc;
-    L->errfunc = func;
-    setoah(ci->callstatus, L->allowhook);  /* save value of 'allowhook' */
-    ci->callstatus |= CIST_YPCALL;  /* function can do error recovery */
+    L->errfunc = efunc;
+    setoah(callstatus(func), L->allowhook);  /* save value of 'allowhook' */
+    callstatus(func) |= CIST_YPCALL;  /* function can do error recovery */
     luaD_call(L, c.func, nresults);  /* do the call */
-    ci->callstatus &= ~CIST_YPCALL;
+    callstatus(func) &= ~CIST_YPCALL;
     L->errfunc = ci->u.c.old_errfunc;
     status = LUA_OK;  /* if it is here, there were no errors */
   }
diff --git a/lapi.h b/lapi.h
index ce64a727..d851d161 100644
--- a/lapi.h
+++ b/lapi.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.h,v 2.9 2015/03/06 19:49:50 roberto Exp roberto $
+** $Id: lapi.h,v 2.10 2017/11/01 18:20:48 roberto Exp roberto $
 ** Auxiliary functions from Lua API
 ** See Copyright Notice in lua.h
 */
@@ -11,11 +11,12 @@
 #include "llimits.h"
 #include "lstate.h"
 
-#define api_incr_top(L)   {L->top++; api_check(L, L->top <= L->ci->top, \
+#define api_incr_top(L)   {L->top++; api_check(L, L->top <= functop(L->func), \
                                 "stack overflow");}
 
 #define adjustresults(L,nres) \
-    { if ((nres) == LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; }
+    { if ((nres) == LUA_MULTRET && functop(L->func) < L->top) \
+      setfunctop(L->func, L->top); }
 
 #define api_checknelems(L,n)    api_check(L, (n) < (L->top - L->func), \
                                   "not enough elements in the stack")
diff --git a/ldebug.c b/ldebug.c
index 5ca78bd1..2db0910c 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.134 2017/11/01 18:20:48 roberto Exp roberto $
+** $Id: ldebug.c,v 2.135 2017/11/02 11:28:56 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -43,7 +43,7 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
 
 
 static int currentpc (CallInfo *ci) {
-  lua_assert(isLua(ci));
+  lua_assert(isLua(ci->func));
   return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
 }
 
@@ -120,7 +120,7 @@ LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
     mask = 0;
     func = NULL;
   }
-  if (isLua(L->ci))
+  if (isLua(L->func))
     L->oldpc = L->ci->u.l.savedpc;
   L->hook = func;
   L->basehookcount = count;
@@ -172,7 +172,7 @@ static const char *findlocal (lua_State *L, CallInfo *ci, int n,
                               StkId *pos) {
   const char *name = NULL;
   StkId base;
-  if (isLua(ci)) {
+  if (isLua(ci->func)) {
     base = ci->func + 1;
     name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
   }
@@ -277,12 +277,12 @@ static void collectvalidlines (lua_State *L, Closure *f) {
 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
   if (ci == NULL)  /* no 'ci'? */
     return NULL;  /* no info */
-  else if (ci->callstatus & CIST_FIN) {  /* is this a finalizer? */
+  else if (callstatus(ci->func) & CIST_FIN) {  /* is this a finalizer? */
     *name = "__gc";
     return "metamethod";  /* report it as such */
   }
   /* calling function is a known Lua function? */
-  else if (!(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
+  else if (!(callstatus(ci->func) & CIST_TAIL) && isLua(ci->previous->func))
     return funcnamefromcode(L, ci->previous, name);
   else return NULL;  /* no way to find a name */
 }
@@ -298,7 +298,7 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
         break;
       }
       case 'l': {
-        ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
+        ar->currentline = (ci && isLua(ci->func)) ? currentline(ci) : -1;
         break;
       }
       case 'u': {
@@ -314,7 +314,7 @@ static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
         break;
       }
       case 't': {
-        ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
+        ar->istailcall = (ci) ? callstatus(ci->func) & CIST_TAIL : 0;
         break;
       }
       case 'n': {
@@ -549,7 +549,7 @@ static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
   Proto *p = ci_func(ci)->p;  /* calling function */
   int pc = currentpc(ci);  /* calling instruction index */
   Instruction i = p->code[pc];  /* calling instruction */
-  if (ci->callstatus & CIST_HOOKED) {  /* was it called inside a hook? */
+  if (callstatus(ci->func) & CIST_HOOKED) {  /* was it called inside a hook? */
     *name = "?";
     return "hook";
   }
@@ -635,7 +635,7 @@ static const char *varinfo (lua_State *L, const TValue *o) {
   const char *name = NULL;  /* to avoid warnings */
   CallInfo *ci = L->ci;
   const char *kind = NULL;
-  if (isLua(ci)) {
+  if (isLua(L->func)) {
     kind = getupvalname(ci, o, &name);  /* check whether 'o' is an upvalue */
     if (!kind && isinstack(L, o))  /* no? try a register */
       kind = getobjname(ci_func(ci)->p, currentpc(ci),
@@ -719,7 +719,7 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
   va_start(argp, fmt);
   msg = luaO_pushvfstring(L, fmt, argp);  /* format message */
   va_end(argp);
-  if (isLua(ci))  /* if Lua function, add source:line information */
+  if (isLua(L->func))  /* if Lua function, add source:line information */
     luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci));
   luaG_errormsg(L);
 }
@@ -740,14 +740,15 @@ static int changedline (Proto *p, int oldpc, int newpc) {
 
 void luaG_traceexec (lua_State *L) {
   CallInfo *ci = L->ci;
+  StkId func = L->func;
   lu_byte mask = L->hookmask;
   int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
   if (counthook)
     resethookcount(L);  /* reset count */
   else if (!(mask & LUA_MASKLINE))
     return;  /* no line hook and count != 0; nothing to be done */
-  if (ci->callstatus & CIST_HOOKYIELD) {  /* called hook last time? */
-    ci->callstatus &= ~CIST_HOOKYIELD;  /* erase mark */
+  if (callstatus(func) & CIST_HOOKYIELD) {  /* called hook last time? */
+    callstatus(func) &= ~CIST_HOOKYIELD;  /* erase mark */
     return;  /* do not call hook again (VM yielded, so it did not move) */
   }
   if (counthook)
@@ -767,7 +768,7 @@ void luaG_traceexec (lua_State *L) {
     if (counthook)
       L->hookcount = 1;  /* undo decrement to zero */
     ci->u.l.savedpc--;  /* undo increment (resume will increment it again) */
-    ci->callstatus |= CIST_HOOKYIELD;  /* mark that it yielded */
+    callstatus(func) |= CIST_HOOKYIELD;  /* mark that it yielded */
     luaD_throw(L, LUA_YIELD);
   }
 }
diff --git a/ldo.c b/ldo.c
index 8c2fca13..cbb1e0f3 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.164 2017/11/01 18:20:48 roberto Exp roberto $
+** $Id: ldo.c,v 2.165 2017/11/02 11:28:56 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -123,8 +123,8 @@ l_noret luaD_throw (lua_State *L, int errcode) {
     else {  /* no handler at all; abort */
       if (g->panic) {  /* panic function? */
         seterrorobj(L, errcode, L->top);  /* assume EXTRA_STACK */
-        if (L->ci->top < L->top)
-          L->ci->top = L->top;  /* pushing msg. can break this invariant */
+        if (functop(L->func) < L->top)  /* check invariant */
+          setfunctop(L->func, L->top);
         lua_unlock(L);
         g->panic(L);  /* call panic function (last chance to jump out) */
       }
@@ -164,7 +164,6 @@ static void correctstack (lua_State *L, StkId oldstack) {
   for (up = L->openupval; up != NULL; up = up->u.open.next)
     up->v = s2v((uplevel(up) - oldstack) + L->stack);
   for (ci = L->ci; ci != NULL; ci = ci->previous) {
-    ci->top = (ci->top - oldstack) + L->stack;
     ci->func = (ci->func - oldstack) + L->stack;
   }
 }
@@ -208,10 +207,11 @@ void luaD_growstack (lua_State *L, int n) {
 
 
 static int stackinuse (lua_State *L) {
-  CallInfo *ci;
   StkId lim = L->top;
-  for (ci = L->ci; ci != NULL; ci = ci->previous) {
-    if (lim < ci->top) lim = ci->top;
+  StkId func = L->func;
+  for (; func->stkci.previous != 0; func -= func->stkci.previous) {
+    if (lim < functop(func))
+      lim = functop(func);
   }
   lua_assert(lim <= L->stack_last);
   return cast_int(lim - L->stack) + 1;  /* part of stack in use */
@@ -255,34 +255,38 @@ void luaD_hook (lua_State *L, int event, int line) {
   if (hook && L->allowhook) {  /* make sure there is a hook */
     CallInfo *ci = L->ci;
     ptrdiff_t top = savestack(L, L->top);
-    ptrdiff_t ci_top = savestack(L, ci->top);
+    int origframesize = L->func->stkci.framesize;
+    int tmpframesize;  /* frame size to run hook */
     lua_Debug ar;
     ar.event = event;
     ar.currentline = line;
     ar.i_ci = ci;
     luaD_checkstack(L, LUA_MINSTACK);  /* ensure minimum stack size */
-    ci->top = L->top + LUA_MINSTACK;
-    lua_assert(ci->top <= L->stack_last);
+    tmpframesize = L->top - L->func + LUA_MINSTACK;
+    if (tmpframesize > origframesize)  /* need to grow frame? */
+      L->func->stkci.framesize = tmpframesize;
+    lua_assert(functop(L->func) <= L->stack_last);
     L->allowhook = 0;  /* cannot call hooks inside a hook */
-    ci->callstatus |= CIST_HOOKED;
+    callstatus(L->func) |= CIST_HOOKED;
     lua_unlock(L);
     (*hook)(L, &ar);
     lua_lock(L);
     lua_assert(!L->allowhook);
     L->allowhook = 1;
-    ci->top = restorestack(L, ci_top);
+    L->func->stkci.framesize = origframesize;
     L->top = restorestack(L, top);
-    ci->callstatus &= ~CIST_HOOKED;
+    callstatus(L->func) &= ~CIST_HOOKED;
   }
 }
 
 
 static void callhook (lua_State *L, CallInfo *ci) {
   int hook = LUA_HOOKCALL;
+  StkId previous = L->func - L->func->stkci.previous;
   ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
-  if (isLua(ci->previous) &&
+  if (isLua(previous) &&
       GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
-    ci->callstatus |= CIST_TAIL;
+    callstatus(L->func) |= CIST_TAIL;
     hook = LUA_HOOKTAILCALL;
   }
   luaD_hook(L, hook, -1);
@@ -358,8 +362,8 @@ static int moveresults (lua_State *L, StkId firstResult, StkId res,
 ** wanted multiple (variable number of) results.
 */
 int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
-  StkId res;
-  int wanted = ci->nresults;
+  StkId res = L->func;  /* res == final position of 1st result */
+  int wanted = res->stkci.nresults;
   if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
     if (L->hookmask & LUA_MASKRET) {
       ptrdiff_t fr = savestack(L, firstResult);  /* hook may change stack */
@@ -368,7 +372,6 @@ int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
     }
     L->oldpc = ci->previous->u.l.savedpc;  /* 'oldpc' for caller function */
   }
-  res = L->func;  /* res == final position of 1st result */
   L->ci = ci->previous;  /* back to caller */
   L->func -= L->func->stkci.previous;
   lua_assert(L->func == L->ci->func);
@@ -402,12 +405,12 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
       int n;  /* number of returns */
       checkstackp(L, LUA_MINSTACK, func);  /* ensure minimum stack size */
       ci = next_ci(L);  /* now 'enter' new function */
-      ci->nresults = nresults;
+      func->stkci.nresults = nresults;
       func->stkci.previous = func - L->func;
       L->func = ci->func = func;
-      ci->top = L->top + LUA_MINSTACK;
-      lua_assert(ci->top <= L->stack_last);
-      ci->callstatus = 0;
+      setfunctop(func, L->top + LUA_MINSTACK);
+      lua_assert(functop(func) <= L->stack_last);
+      callstatus(func) = 0;
       if (L->hookmask & LUA_MASKCALL)
         luaD_hook(L, LUA_HOOKCALL, -1);
       lua_unlock(L);
@@ -427,13 +430,14 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
       if (p->is_vararg)
         luaT_adjustvarargs(L, p, n);
       ci = next_ci(L);  /* now 'enter' new function */
-      ci->nresults = nresults;
+      func->stkci.nresults = nresults;
       func->stkci.previous = func - L->func;
+      func->stkci.framesize = fsize + 1;  /* size includes function itself */
       L->func = ci->func = func;
-      L->top = ci->top = func + 1 + fsize;
-      lua_assert(ci->top <= L->stack_last);
+      L->top = func + 1 + fsize;
+      lua_assert(functop(func) <= L->stack_last);
       ci->u.l.savedpc = p->code;  /* starting point */
-      ci->callstatus = CIST_LUA;
+      callstatus(func) = 0;
       if (L->hookmask & LUA_MASKCALL)
         callhook(L, ci);
       return 0;
@@ -493,18 +497,19 @@ void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
 */
 static void finishCcall (lua_State *L, int status) {
   CallInfo *ci = L->ci;
+  StkId func = L->func;
   int n;
   /* must have a continuation and must be able to call it */
   lua_assert(ci->u.c.k != NULL && L->nny == 0);
   /* error status can only happen in a protected call */
-  lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
-  if (ci->callstatus & CIST_YPCALL) {  /* was inside a pcall? */
-    ci->callstatus &= ~CIST_YPCALL;  /* continuation is also inside it */
+  lua_assert((callstatus(func) & CIST_YPCALL) || status == LUA_YIELD);
+  if (callstatus(func) & CIST_YPCALL) {  /* was inside a pcall? */
+    callstatus(func) &= ~CIST_YPCALL;  /* continuation is also inside it */
     L->errfunc = ci->u.c.old_errfunc;  /* with the same error function */
   }
   /* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already
      handled */
-  adjustresults(L, ci->nresults);
+  adjustresults(L, func->stkci.nresults);
   lua_unlock(L);
   n = (*ci->u.c.k)(L, status, ci->u.c.ctx);  /* call continuation function */
   lua_lock(L);
@@ -525,7 +530,7 @@ static void unroll (lua_State *L, void *ud) {
   if (ud != NULL)  /* error status? */
     finishCcall(L, *(int *)ud);  /* finish 'lua_pcallk' callee */
   while (L->ci != &L->base_ci) {  /* something in the stack */
-    if (!isLua(L->ci))  /* C function? */
+    if (!isLua(L->func))  /* C function? */
       finishCcall(L, LUA_YIELD);  /* complete its execution */
     else {  /* Lua function */
       luaV_finishOp(L);  /* finish interrupted instruction */
@@ -542,7 +547,7 @@ static void unroll (lua_State *L, void *ud) {
 static CallInfo *findpcall (lua_State *L) {
   CallInfo *ci;
   for (ci = L->ci; ci != NULL; ci = ci->previous) {  /* search for a pcall */
-    if (ci->callstatus & CIST_YPCALL)
+    if (callstatus(ci->func) & CIST_YPCALL)
       return ci;
   }
   return NULL;  /* no pending pcall */
@@ -564,7 +569,7 @@ static int recover (lua_State *L, int status) {
   seterrorobj(L, status, oldtop);
   L->ci = ci;
   L->func = ci->func;
-  L->allowhook = getoah(ci->callstatus);  /* restore original 'allowhook' */
+  L->allowhook = getoah(callstatus(L->func));  /* restore original 'allowhook' */
   L->nny = 0;  /* should be zero to be yieldable */
   luaD_shrinkstack(L);
   L->errfunc = ci->u.c.old_errfunc;
@@ -604,7 +609,7 @@ static void resume (lua_State *L, void *ud) {
   else {  /* resuming from previous yield */
     lua_assert(L->status == LUA_YIELD);
     L->status = LUA_OK;  /* mark that it is running (again) */
-    if (isLua(ci))  /* yielded inside a hook? */
+    if (isLua(L->func))  /* yielded inside a hook? */
       luaV_execute(L);  /* just continue running Lua code */
     else {  /* 'common' yield */
       if (ci->u.c.k != NULL) {  /* does it have a continuation function? */
@@ -649,7 +654,7 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
     if (errorstatus(status)) {  /* unrecoverable error? */
       L->status = cast_byte(status);  /* mark thread as 'dead' */
       seterrorobj(L, status, L->top);  /* push error message */
-      L->ci->top = L->top;
+      L->func->stkci.framesize = L->top - L->func;
     }
     else lua_assert(status == L->status);  /* normal end or yield */
   }
@@ -671,6 +676,7 @@ LUA_API int lua_isyieldable (lua_State *L) {
 LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
                         lua_KFunction k) {
   CallInfo *ci = L->ci;
+  StkId func = L->func;
   luai_userstateyield(L, nresults);
   lua_lock(L);
   api_checknelems(L, nresults);
@@ -681,7 +687,7 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
       luaG_runerror(L, "attempt to yield from outside a coroutine");
   }
   L->status = LUA_YIELD;
-  if (isLua(ci)) {  /* inside a hook? */
+  if (isLua(func)) {  /* inside a hook? */
     api_check(L, k == NULL, "hooks cannot continue after yielding");
     ci->u2.nyield = 0;  /* no results */
   }
@@ -691,7 +697,7 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
     ci->u2.nyield = nresults;  /* save number of results */
     luaD_throw(L, LUA_YIELD);
   }
-  lua_assert(ci->callstatus & CIST_HOOKED);  /* must be inside a hook */
+  lua_assert(callstatus(func) & CIST_HOOKED);  /* must be inside a hook */
   lua_unlock(L);
   return 0;  /* return to 'luaD_hook' */
 }
diff --git a/lgc.c b/lgc.c
index d9b31958..2155b28d 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.235 2017/10/11 12:38:45 roberto Exp roberto $
+** $Id: lgc.c,v 2.236 2017/10/31 15:29:28 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -866,9 +866,9 @@ static void GCTM (lua_State *L, int propagateerrors) {
     setobj2s(L, L->top, tm);  /* push finalizer... */
     setobj2s(L, L->top + 1, &v);  /* ... and its argument */
     L->top += 2;  /* and (next line) call the finalizer */
-    L->ci->callstatus |= CIST_FIN;  /* will run a finalizer */
+    callstatus(L->func) |= CIST_FIN;  /* will run a finalizer */
     status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0);
-    L->ci->callstatus &= ~CIST_FIN;  /* not running a finalizer anymore */
+    callstatus(L->func) &= ~CIST_FIN;  /* not running a finalizer anymore */
     L->allowhook = oldah;  /* restore hooks */
     g->gcrunning = running;  /* restore state */
     if (status != LUA_OK && propagateerrors) {  /* error while running __gc? */
diff --git a/lobject.h b/lobject.h
index e3ae0050..66c41e6f 100644
--- a/lobject.h
+++ b/lobject.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lobject.h,v 2.125 2017/06/29 15:06:44 roberto Exp roberto $
+** $Id: lobject.h,v 2.126 2017/10/31 17:54:35 roberto Exp roberto $
 ** Type definitions for Lua objects
 ** See Copyright Notice in lua.h
 */
@@ -313,10 +313,21 @@ typedef union StackValue {
   TValue val;
   struct {
     TValuefields;
+    lu_byte callstatus_;
     unsigned short previous;  /* difference to previous 'func' */
+    short nresults;  /* expected number of results from this function */
+    unsigned short framesize;  /* stack space available for this function */
   } stkci;
 } StackValue;
 
+#define callstatus(ar)  ((ar)->stkci.callstatus_)
+
+/* top of a function (first element after its frame) */
+#define functop(func)   ((func) + (func)->stkci.framesize)
+
+/* set top of a function to a specific value */
+#define setfunctop(func,v)      ((func)->stkci.framesize = (v) - (func))
+
 
 typedef StackValue *StkId;  /* index to stack elements */
 
diff --git a/lstate.c b/lstate.c
index c4305ed8..8e3177ca 100644
--- a/lstate.c
+++ b/lstate.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.c,v 2.142 2017/10/11 12:38:45 roberto Exp roberto $
+** $Id: lstate.c,v 2.143 2017/10/31 17:54:35 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -152,12 +152,12 @@ static void stack_init (lua_State *L1, lua_State *L) {
   /* initialize first ci */
   ci = &L1->base_ci;
   ci->next = ci->previous = NULL;
-  ci->callstatus = 0;
   L1->func = ci->func = L1->top;
   L1->func->stkci.previous = 0;  /* end of linked list */
+  L1->func->stkci.framesize = LUA_MINSTACK + 1;
+  callstatus(L1->func) = 0;
   setnilvalue(s2v(L1->top));  /* 'function' entry for this 'ci' */
   L1->top++;
-  ci->top = L1->top + LUA_MINSTACK;
   L1->ci = ci;
 }
 
diff --git a/lstate.h b/lstate.h
index 8b9eb606..3d76e9b9 100644
--- a/lstate.h
+++ b/lstate.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 2.145 2017/10/31 17:54:35 roberto Exp roberto $
+** $Id: lstate.h,v 2.146 2017/11/02 11:28:56 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -86,7 +86,6 @@ typedef struct stringtable {
 */
 typedef struct CallInfo {
   StkId func;  /* function index in the stack */
-  StkId top;  /* top for this function */
   struct CallInfo *previous, *next;  /* dynamic call link */
   union {
     struct {  /* only for Lua functions */
@@ -102,8 +101,6 @@ typedef struct CallInfo {
     ptrdiff_t funcidx;  /* called-function index */
     int nyield;  /* number of values yielded */
   } u2;
-  short nresults;  /* expected number of results from this function */
-  unsigned short callstatus;
 } CallInfo;
 
 
@@ -111,17 +108,16 @@ typedef struct CallInfo {
 ** Bits in CallInfo status
 */
 #define CIST_OAH        (1<<0)  /* original value of 'allowhook' */
-#define CIST_LUA        (1<<1)  /* call is running a Lua function */
-#define CIST_HOOKED     (1<<2)  /* call is running a debug hook */
-#define CIST_FRESH      (1<<3)  /* call is running on a fresh invocation
+#define CIST_HOOKED     (1<<1)  /* call is running a debug hook */
+#define CIST_FRESH      (1<<2)  /* call is running on a fresh invocation
                                    of luaV_execute */
-#define CIST_YPCALL     (1<<4)  /* call is a yieldable protected call */
-#define CIST_TAIL       (1<<5)  /* call was tail called */
-#define CIST_HOOKYIELD  (1<<6)  /* last hook called yielded */
-#define CIST_LEQ        (1<<7)  /* using __lt for __le */
-#define CIST_FIN        (1<<8)  /* call is running a finalizer */
+#define CIST_YPCALL     (1<<3)  /* call is a yieldable protected call */
+#define CIST_TAIL       (1<<4)  /* call was tail called */
+#define CIST_HOOKYIELD  (1<<5)  /* last hook called yielded */
+#define CIST_LEQ        (1<<6)  /* using __lt for __le */
+#define CIST_FIN        (1<<7)  /* call is running a finalizer */
 
-#define isLua(ci)       ((ci)->callstatus & CIST_LUA)
+#define isLua(func)     isLfunction(s2v(func))
 
 /* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */
 #define setoah(st,v)    ((st) = ((st) & ~CIST_OAH) | (v))
diff --git a/ltests.c b/ltests.c
index d05fc3b1..71ad09ea 100644
--- a/ltests.c
+++ b/ltests.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltests.c,v 2.226 2017/11/01 18:20:48 roberto Exp roberto $
+** $Id: ltests.c,v 2.227 2017/11/02 11:28:56 roberto Exp roberto $
 ** Internal Module for Debugging of the Lua Implementation
 ** See Copyright Notice in lua.h
 */
@@ -310,7 +310,7 @@ static void checkLclosure (global_State *g, LClosure *cl) {
 
 
 static int lua_checkpc (CallInfo *ci) {
-  if (!isLua(ci)) return 1;
+  if (!isLua(ci->func)) return 1;
   else {
     StkId f = ci->func;
     Proto *p = clLvalue(s2v(f))->p;
@@ -327,10 +327,11 @@ static void checkstack (global_State *g, lua_State *L1) {
   lua_assert(!isdead(g, L1));
   for (uv = L1->openupval; uv != NULL; uv = uv->u.open.next)
     lua_assert(upisopen(uv));  /* must be open */
-  for (ci = L1->ci; ci != NULL; ci = ci->previous) {
-    lua_assert(ci->top <= L1->stack_last);
+  for (ci = L1->ci; ci != NULL; ci = ci->previous)
     lua_assert(lua_checkpc(ci));
-  }
+  for (o = L1->func; o->stkci.previous != 0; o -= o->stkci.previous)
+    lua_assert(functop(o) <= L1->stack_last);
+  lua_assert(o == L1->stack);
   if (L1->stack) {  /* complete thread? */
     for (o = L1->stack; o < L1->stack_last + EXTRA_STACK; o++)
       checkliveness(L1, s2v(o));  /* entire stack must have valid values */
diff --git a/ltm.c b/ltm.c
index 1534992b..6c13e8d1 100644
--- a/ltm.c
+++ b/ltm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltm.c,v 2.44 2017/09/27 18:59:08 roberto Exp roberto $
+** $Id: ltm.c,v 2.45 2017/10/04 15:49:05 roberto Exp roberto $
 ** Tag methods
 ** See Copyright Notice in lua.h
 */
@@ -108,7 +108,7 @@ void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1,
   setobj2s(L, func + 3, p3);  /* 3rd argument */
   L->top += 4;
   /* metamethod may yield only when called from Lua code */
-  if (isLua(L->ci))
+  if (isLua(L->func))
     luaD_call(L, func, 0);
   else
     luaD_callnoyield(L, func, 0);
@@ -124,7 +124,7 @@ void luaT_callTMres (lua_State *L, const TValue *f, const TValue *p1,
   setobj2s(L, func + 2, p2);  /* 2nd argument */
   L->top += 3;
   /* metamethod may yield only when called from Lua code */
-  if (isLua(L->ci))
+  if (isLua(L->func))
     luaD_call(L, func, 1);
   else
     luaD_callnoyield(L, func, 1);
diff --git a/lvm.c b/lvm.c
index 25b953a4..7acb387f 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.300 2017/10/31 17:54:35 roberto Exp roberto $
+** $Id: lvm.c,v 2.301 2017/11/01 18:20:48 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -390,9 +390,9 @@ int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
   else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0)  /* try 'le' */
     return res;
   else {  /* try 'lt': */
-    L->ci->callstatus |= CIST_LEQ;  /* mark it is doing 'lt' for 'le' */
+    callstatus(L->func) |= CIST_LEQ;  /* mark it is doing 'lt' for 'le' */
     res = luaT_callorderTM(L, r, l, TM_LT);
-    L->ci->callstatus ^= CIST_LEQ;  /* clear mark */
+    callstatus(L->func) ^= CIST_LEQ;  /* clear mark */
     if (res < 0)
       luaG_ordererror(L, l, r);
     return !res;  /* result is negated */
@@ -679,9 +679,9 @@ void luaV_finishOp (lua_State *L) {
     case OP_LE: case OP_LT: case OP_EQ: {
       int res = !l_isfalse(s2v(L->top - 1));
       L->top--;
-      if (ci->callstatus & CIST_LEQ) {  /* "<=" using "<" instead? */
+      if (callstatus(base - 1) & CIST_LEQ) {  /* "<=" using "<" ? */
         lua_assert(op == OP_LE);
-        ci->callstatus ^= CIST_LEQ;  /* clear mark */
+        callstatus(base - 1) ^= CIST_LEQ;  /* clear mark */
         res = !res;  /* negate result */
       }
       lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP);
@@ -700,17 +700,17 @@ void luaV_finishOp (lua_State *L) {
       }
       /* move final result to final position */
       setobjs2s(L, L->func + 1 + GETARG_A(inst), L->top - 1);
-      L->top = ci->top;  /* restore top */
+      L->top = functop(base - 1);  /* restore top */
       break;
     }
     case OP_TFORCALL: {
       lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP);
-      L->top = ci->top;  /* correct top */
+      L->top = functop(base - 1);  /* correct top */
       break;
     }
     case OP_CALL: {
       if (GETARG_C(inst) - 1 >= 0)  /* nresults >= 0? */
-        L->top = ci->top;  /* adjust results */
+        L->top = functop(base - 1);  /* adjust results */
       break;
     }
     case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE:
@@ -775,9 +775,9 @@ void luaV_finishOp (lua_State *L) {
 
 
 #define checkGC(L,c)  \
-        { luaC_condGC(L, L->top = (c),  /* limit of live values */ \
-                         Protect(L->top = ci->top));  /* restore top */ \
-           luai_threadyield(L); }
+  { luaC_condGC(L, L->top = (c),  /* limit of live values */ \
+    {Protect((void)0); L->top = functop(base - 1);});  /* restore top */ \
+    luai_threadyield(L); }
 
 
 /* fetch an instruction and prepare its execution */
@@ -796,16 +796,15 @@ void luaV_execute (lua_State *L) {
   CallInfo *ci = L->ci;
   LClosure *cl;
   TValue *k;
-  StkId base;  /* local copy of 'L->func + 1' */
+  StkId base = L->func + 1;  /* local copy of 'L->func + 1' */
   int mask;  /* local copy of 'L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)' */
   const Instruction *pc;  /* local copy of 'ci->u.l.savedpc' */
-  ci->callstatus |= CIST_FRESH;  /* fresh invocation of 'luaV_execute" */
+  callstatus(base - 1) |= CIST_FRESH;  /* fresh invocation of 'luaV_execute" */
  newframe:  /* reentry point when frame changes (call/return) */
   lua_assert(ci == L->ci);
   cl = clLvalue(s2v(L->func));  /* local reference to function's closure */
   k = cl->p->k;  /* local reference to function's constant table */
   updatemask(L);
-  base = L->func + 1;
   pc = ci->u.l.savedpc;
   /* main loop of interpreter */
   for (;;) {
@@ -1276,7 +1275,7 @@ void luaV_execute (lua_State *L) {
         rb = base + b;
         setobjs2s(L, ra, rb);
         checkGC(L, (ra >= rb ? ra + 1 : rb));
-        L->top = ci->top;  /* restore top */
+        L->top = functop(base - 1);  /* restore top */
         vmbreak;
       }
       vmcase(OP_CLOSE) {
@@ -1355,11 +1354,12 @@ void luaV_execute (lua_State *L) {
         Protect(isC = luaD_precall(L, ra, nresults));
         if (isC) {  /* C function? */
           if (nresults >= 0)  /* fixed number of results? */
-            L->top = ci->top;  /* correct top */
+            L->top = functop(base - 1);  /* correct top */
           /* else leave top for next instruction */
         }
         else {  /* Lua function */
           ci = L->ci;
+          base = L->func + 1;
           goto newframe;  /* restart luaV_execute over new Lua function */
         }
         vmbreak;
@@ -1386,12 +1386,14 @@ void luaV_execute (lua_State *L) {
           /* move new frame into old one */
           for (aux = 0; nfunc + aux < lim; aux++)
             setobjs2s(L, ofunc + aux, nfunc + aux);
-          oci->top = L->top = ofunc + (L->top - nfunc);  /* correct top */
+          ofunc->stkci.framesize = L->top - nfunc;
+          L->top = functop(ofunc);  /* correct top */
           oci->u.l.savedpc = nci->u.l.savedpc;
-          oci->callstatus |= CIST_TAIL;  /* function was tail called */
+          callstatus(ofunc) |= CIST_TAIL;  /* function was tail called */
           ci = L->ci = oci;  /* remove new frame */
+          base = ofunc + 1;
           L->func = ofunc;
-          lua_assert(L->top == ofunc + 1 + getproto(s2v(ofunc))->maxstacksize);
+          lua_assert(L->top == base + getproto(s2v(ofunc))->maxstacksize);
           goto newframe;  /* restart luaV_execute over new Lua function */
         }
         vmbreak;
@@ -1401,14 +1403,15 @@ void luaV_execute (lua_State *L) {
         if (cl->p->sizep > 0) luaF_close(L, base);
         savepc(L);
         b = luaD_poscall(L, ci, ra, (b != 0 ? b - 1 : cast_int(L->top - ra)));
-        if (ci->callstatus & CIST_FRESH)  /* local 'ci' still from callee */
+        if (callstatus(base - 1) & CIST_FRESH)  /* local 'base' still from callee */
           return;  /* external invocation: return */
         else {  /* invocation via reentry: continue execution */
           ci = L->ci;
-          if (b) L->top = ci->top;
-          lua_assert(isLua(ci));
+          base = L->func + 1;
+          if (b) L->top = functop(base - 1);
+          lua_assert(isLua(L->func));
           lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL);
-          goto newframe;  /* restart luaV_execute over new Lua function */
+          goto newframe;  /* restart luaV_execute over previous Lua function */
         }
       }
       vmcase(OP_FORLOOP) {
@@ -1473,7 +1476,7 @@ void luaV_execute (lua_State *L) {
         setobjs2s(L, cb, ra);
         L->top = cb + 3;  /* func. + 2 args (state and index) */
         Protect(luaD_call(L, cb, GETARG_C(i)));
-        L->top = ci->top;
+        L->top = functop(base - 1);
         i = *(pc++);  /* go to next instruction */
         ra = RA(i);
         lua_assert(GET_OPCODE(i) == OP_TFORLOOP);
@@ -1507,7 +1510,8 @@ void luaV_execute (lua_State *L) {
           last--;
           luaC_barrierback(L, h, val);
         }
-        L->top = ci->top;  /* correct top (in case of previous open call) */
+        /* correct top (in case of previous open call) */
+        L->top = functop(base - 1);
         vmbreak;
       }
       vmcase(OP_CLOSURE) {