static bool inter_copy_one(lua_State* from, lua_State* to, int cache, int i){
//int top_to = lua_gettop(to);
ASSERT(lua_istable(to, cache));
if(lua_checkstack(to, 2) != 1)
return false; // todo: output errors
bool ret = true;
switch(lua_type(from, i)){
case LUA_TNIL:
lua_pushnil(to);
break;
case LUA_TBOOLEAN:
lua_pushboolean(to, lua_toboolean(from, i));
break;
case LUA_TLIGHTUSERDATA:
lua_pushlightuserdata(to, lua_touserdata(from, i));
break;
case LUA_TNUMBER:
lua_pushnumber(to, lua_tonumber(from, i));
break;
case LUA_TSTRING:
{
size_t len;
const char *s = lua_tolstring(from, i, &len);
lua_pushlstring(to, s, len);
}
break;
case LUA_TTABLE:
ret = inter_copy_table(from, to, cache, i);
break;
case LUA_TFUNCTION:
ret = inter_copy_func(from, to, cache, i);
break;
case LUA_TUSERDATA:
ret = inter_copy_userdata(from, to, cache, i);
break;
case LUA_TTHREAD:
ret = false;
break;
};
return ret;
}
static
void push_cached_func( lua_State *L2, uint_t L2_cache_i, lua_State *L, uint_t i ) {
// TBD: Merge this and same code for tables
ASSERT_L( hijacked_tostring );
ASSERT_L( L2_cache_i != 0 );
STACK_GROW(L,2);
STACK_GROW(L2,3);
STACK_CHECK(L)
lua_pushcfunction( L, hijacked_tostring );
lua_pushvalue( L, i );
lua_call( L, 1 /*args*/, 1 /*retvals*/ );
//
// [-1]: "function: 0x...."
STACK_END(L,1)
ASSERT_L( lua_type(L,-1) == LUA_TSTRING );
// L2_cache[id_str]= function
//
STACK_CHECK(L2)
// We don't need to use the from state ('L') in ID since the life span
// is only for the duration of a copy (both states are locked).
//
lua_pushstring( L2, lua_tostring(L,-1) );
lua_pop(L,1); // remove the 'tostring(tbl)' value (in L!)
//fprintf( stderr, "<< ID: %s >>\n", lua_tostring(L2,-1) );
lua_pushvalue( L2, -1 );
lua_rawget( L2, L2_cache_i );
//
// [-2]: identity string ("function: 0x...")
// [-1]: function|nil|true (true means: we're working on it; recursive)
if (lua_isnil(L2,-1)) {
lua_pop(L2,1);
// Set to 'true' for the duration of creation; need to find self-references
// via upvalues
//
lua_pushboolean(L2,TRUE);
lua_setfield( L2, L2_cache_i, lua_tostring(L2,-2) );
inter_copy_func( L2, L2_cache_i, L, i ); // pushes a copy of the func
lua_pushvalue(L2,-1);
lua_insert(L2,-3);
//
// [-3]: function (2nd ref)
// [-2]: identity string
// [-1]: function
lua_rawset(L2,L2_cache_i);
//
// [-1]: function (tied to 'L2_cache' table')
} else if (lua_isboolean(L2,-1)) {
// Loop in preparing upvalues; either direct or via a table
//
// Note: This excludes the case where a function directly addresses
// itself as an upvalue (recursive lane creation).
//
luaL_error( L, "Recursive use of upvalues; cannot copy the function" );
} else {
lua_remove(L2,-2);
}
STACK_END(L2,1)
//
// L2 [-1]: function
ASSERT_L( lua_isfunction(L2,-1) );
}