25 ** hook function.
89 ** Auxiliary function used by several library functions: check for
90 ** an optional thread as function's first argument and set 'arg' with
101     return L;  /* function will operate over current thread */  in getthread()
113   lua_setfield(L, -2, k);  in settabss()
118   lua_setfield(L, -2, k);  in settabsi()
123   lua_setfield(L, -2, k);  in settabsb()
128 ** In function 'db_getinfo', the call to 'lua_getinfo' may push
130 ** these objects. Function 'treatstackoption' puts the result from
136     lua_rotate(L, -2, 1);  /* exchange object and table */  in treatstackoption()
139   lua_setfield(L, -2, fname);  /* put object into table */  in treatstackoption()
145 ** L1 needs stack space for an optional input (function) plus
146 ** two optional outputs (function and line table) from function
156   if (lua_isfunction(L, arg + 1)) {  /* info about a function? */  in db_getinfo()
158     lua_pushvalue(L, arg + 1);  /* move function to 'L1' stack */  in db_getinfo()
172     lua_setfield(L, -2, "source");  in db_getinfo()
206   int nvar = (int)luaL_checkinteger(L, arg + 2);  /* local-variable index */  in db_getlocal()
207   if (lua_isfunction(L, arg + 1)) {  /* function argument? */  in db_getlocal()
208     lua_pushvalue(L, arg + 1);  /* push function */  in db_getlocal()
212   else {  /* stack-level argument */  in db_getlocal()
223       lua_rotate(L, -2, 1);  /* re-order */  in db_getlocal()
265   lua_insert(L, -(get+1));  /* no-op if get is false */  in auxupvalue()
312   luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected");  in db_upvaluejoin()
313   luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected");  in db_upvaluejoin()
320 ** Call hook function registered at hook table for the current
328   if (lua_rawget(L, -2) == LUA_TFUNCTION) {  /* is there a hook function? */  in hookf()
329     lua_pushstring(L, hooknames[(int)ar->event]);  /* push event name */  in hookf()
330     if (ar->currentline >= 0)  in hookf()
331       lua_pushinteger(L, ar->currentline);  /* push current line */  in hookf()
334     lua_call(L, 2, 0);  /* call hook function */  in hookf()
340 ** Convert a string mask (for 'sethook') into a bit mask
343   int mask = 0;  in makemask()  local
344   if (strchr(smask, 'c')) mask |= LUA_MASKCALL;  in makemask()
345   if (strchr(smask, 'r')) mask |= LUA_MASKRET;  in makemask()
346   if (strchr(smask, 'l')) mask |= LUA_MASKLINE;  in makemask()
347   if (count > 0) mask |= LUA_MASKCOUNT;  in makemask()
348   return mask;  in makemask()
353 ** Convert a bit mask (for 'gethook') into a string mask
355 static char *unmakemask (int mask, char *smask) {  in unmakemask()  argument
357   if (mask & LUA_MASKCALL) smask[i++] = 'c';  in unmakemask()
358   if (mask & LUA_MASKRET) smask[i++] = 'r';  in unmakemask()
359   if (mask & LUA_MASKLINE) smask[i++] = 'l';  in unmakemask()
366   int arg, mask, count;  in db_sethook()  local
371     func = NULL; mask = 0; count = 0;  /* turn off hooks */  in db_sethook()
377     func = hookf; mask = makemask(smask, count);  in db_sethook()
382     lua_setfield(L, -2, "__mode");  /** hooktable.__mode = "k" */  in db_sethook()
383     lua_pushvalue(L, -1);  in db_sethook()
384     lua_setmetatable(L, -2);  /* metatable(hooktable) = hooktable */  in db_sethook()
388   lua_pushvalue(L, arg + 1);  /* value (hook function) */  in db_sethook()
389   lua_rawset(L, -3);  /* hooktable[L1] = new Lua hook */  in db_sethook()
390   lua_sethook(L1, func, mask, count);  in db_sethook()
399   int mask = lua_gethookmask(L1);  in db_gethook()  local
411     lua_rawget(L, -2);   /* 1st result = hooktable[L1] */  in db_gethook()
412     lua_remove(L, -2);  /* remove hook table */  in db_gethook()
414   lua_pushstring(L, unmakemask(mask, buff));  /* 2nd result = mask */  in db_gethook()
429       lua_writestringerror("%s\n", luaL_tolstring(L, -1, NULL));  in db_debug()
439   if (msg == NULL && !lua_isnoneornil(L, arg + 1))  /* non-string 'msg'? */  in db_traceback()