4 files changed, 23 insertions, 21 deletions

diff --git a/ldebug.c b/ldebug.c
index 3ea6367f..93a935a5 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldebug.c,v 2.151 2017/12/28 15:42:57 roberto Exp roberto $
+** $Id: ldebug.c,v 2.152 2018/01/10 12:02:35 roberto Exp roberto $
 ** Debug Interface
 ** See Copyright Notice in lua.h
 */
@@ -143,7 +143,7 @@ LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
   L->basehookcount = count;
   resethookcount(L);
   L->hookmask = cast_byte(mask);
-  if (mask & (LUA_MASKLINE | LUA_MASKCOUNT))
+  if (mask)
     settraps(L->ci);  /* to trace inside 'luaV_execute' */
 }
 
diff --git a/ldo.c b/ldo.c
index 6ab57f8e..d627941c 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.188 2018/01/28 13:39:52 roberto Exp roberto $
+** $Id: ldo.c,v 2.189 2018/01/29 16:21:35 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -294,19 +294,21 @@ void luaD_hook (lua_State *L, int event, int line) {
 }
 
 
-static void hookcall (lua_State *L, CallInfo *ci, int istail) {
-  int hook;
-  ci->u.l.trap = 1;
-  if (!(L->hookmask & LUA_MASKCALL))
-    return;  /* some other hook */
+/*
+** Executes a call hook for Lua functions. This function is called
+** whenever 'hookmask' is not zero, so it checks whether call hooks are
+** active. Also, this function can be called when resuming a function,
+** so it checks whether the function is in its first instruction.
+*/
+void luaD_hookcall (lua_State *L, CallInfo *ci) {
+  Proto *p = clLvalue(s2v(ci->func))->p;
+  int hook = (ci->callstatus & CIST_TAIL) ? LUA_HOOKTAILCALL : LUA_HOOKCALL;
+  ci->u.l.trap = 1;  /* there may be other hooks */
+  if (!(L->hookmask & LUA_MASKCALL) ||  /* some other hook? */
+      ci->u.l.savedpc != p->code)  /* not 1st instruction? */
+    return;  /* don't call hook */
   L->top = ci->top;  /* prepare top */
   ci->u.l.savedpc++;  /* hooks assume 'pc' is already incremented */
-  if (istail) {
-    ci->callstatus |= CIST_TAIL;
-    hook = LUA_HOOKTAILCALL;
-  }
-  else
-    hook = LUA_HOOKCALL;
   luaD_hook(L, hook, -1);
   ci->u.l.savedpc--;  /* correct 'pc' */
 }
@@ -427,8 +429,6 @@ void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int narg1) {
     L->top = func + narg1;  /* set top */
     luaT_adjustvarargs(L, nfixparams, narg1 - 1);
   }
-  if (L->hookmask)
-    hookcall(L, ci, 1);
 }
 
 
@@ -483,8 +483,6 @@ void luaD_call (lua_State *L, StkId func, int nresults) {
       ci->callstatus = 0;
       if (p->is_vararg)
         luaT_adjustvarargs(L, nfixparams, narg);  /* may invoke GC */
-      if (L->hookmask)
-        hookcall(L, ci, 0);
       luaV_execute(L, ci);  /* run the function */
       break;
     }
diff --git a/ldo.h b/ldo.h
index 50f79242..44e3af20 100644
--- a/ldo.h
+++ b/ldo.h
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.h,v 2.38 2017/12/11 12:43:40 roberto Exp roberto $
+** $Id: ldo.h,v 2.39 2018/01/10 19:19:27 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -48,6 +48,7 @@ typedef void (*Pfunc) (lua_State *L, void *ud);
 LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name,
                                                   const char *mode);
 LUAI_FUNC void luaD_hook (lua_State *L, int event, int line);
+LUAI_FUNC void luaD_hookcall (lua_State *L, CallInfo *ci);
 LUAI_FUNC void luaD_pretailcall (lua_State *L, CallInfo *ci, StkId func, int n);
 LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults);
 LUAI_FUNC void luaD_callnoyield (lua_State *L, StkId func, int nResults);
diff --git a/lvm.c b/lvm.c
index d6380e4b..d9814b62 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.335 2018/01/27 16:56:33 roberto Exp roberto $
+** $Id: lvm.c,v 2.336 2018/01/29 16:21:35 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -832,8 +832,11 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
   TValue *k;
   StkId base;
   const Instruction *pc;
-  int trap = ci->u.l.trap;
+  int trap;
  tailcall:
+  trap = L->hookmask;
+  if (trap)
+    luaD_hookcall(L, ci);
   cl = clLvalue(s2v(ci->func));
   k = cl->p->k;
   base = ci->func + 1;