Function db_errorfb

Source/Misc/lua/src/lua.c:11838–11888

#define LEVELS2	10	/* size of the second part of the stack */

static int db_errorfb (lua_State *L) {
int level;
int firstpart = 1;  /* still before eventual `...' */
int arg;
lua_State *L1 = getthread(L, &arg);
lua_Debug ar;
if (lua_isnumber(L, arg+2)) {
level = (int)lua_tointeger(L, arg+2);
lua_pop(L, 1);
}
else
level = (L == L1) ? 1 : 0;  /* level 0 may be this own function */
if (lua_gettop(L) == arg)
lua_pushliteral(L, "");
else if (!lua_isstring(L, arg+1)) return 1;  /* message is not a string */
else lua_pushliteral(L, "\n");
lua_pushliteral(L, "stack traceback:");
while (lua_getstack(L1, level++, &ar)) {
if (level > LEVELS1 && firstpart) {
/* no more than `LEVELS2' more levels? */
if (!lua_getstack(L1, level+LEVELS2, &ar))
level--;  /* keep going */
else {
lua_pushliteral(L, "\n\t...");  /* too many levels */
while (lua_getstack(L1, level+LEVELS2, &ar))  /* find last levels */
level++;
}
firstpart = 0;
continue;
}
lua_pushliteral(L, "\n\t");
lua_getinfo(L1, "Snl", &ar);
lua_pushfstring(L, "%s:", ar.short_src);
if (ar.currentline > 0)
lua_pushfstring(L, "%d:", ar.currentline);
if (*ar.namewhat != '\0')  /* is there a name? */
lua_pushfstring(L, " in function " LUA_QS, ar.name);
else {
if (*ar.what == 'm')  /* main? */
lua_pushfstring(L, " in main chunk");
else if (*ar.what == 'C' || *ar.what == 't')
lua_pushliteral(L, " ?");  /* C function or tail call */
else
lua_pushfstring(L, " in function <%s:%d>",
ar.short_src, ar.linedefined);
}
lua_concat(L, lua_gettop(L) - arg);
}
lua_concat(L, lua_gettop(L) - arg);
return 1;
}


static const luaL_Reg dblib[] = {