Upvalues: replace upvalue only if it's equal to _G (#110)

src/cpp/function.cpp

@@ -2,28 +2,6 @@
 
 namespace effil {
 
-namespace {
-
-bool allowTableUpvalues(const sol::optional<bool>& newValue = sol::nullopt) {
-    static std::atomic_bool value(true);
-
-    if (newValue)
-        return value.exchange(newValue.value());
-    return value;
-}
-
-} // anonymous
-
-sol::object luaAllowTableUpvalues(sol::this_state state, const sol::stack_object& value) {
-    if (value.valid()) {
-        REQUIRE(value.get_type() == sol::type::boolean) << "bad argument #1 to 'effil.allow_table_upvalues' (boolean expected, got " << luaTypename(value) << ")";
-        return sol::make_object(state, allowTableUpvalues(value.template as<bool>()));
-    }
-    else {
-        return sol::make_object(state, allowTableUpvalues());
-    }
-}
-
 Function::Function(const sol::function& luaObject) {
     assert(luaObject.valid());
     assert(luaObject.get_type() == sol::type::function);
@@ -38,30 +16,29 @@ Function::Function(const sol::function& luaObject) {
     ctx_->function = dumpFunction(luaObject);
     ctx_->upvalues.resize(dbgInfo.nups);
 #if LUA_VERSION_NUM > 501
-    ctx_->envUpvaluePos = 0; // means no _ENV upvalue
+    ctx_->envUpvaluePos = 0; // means no _G upvalue
+
+    lua_pushglobaltable(state);
+    const auto gTable = sol::stack::pop<sol::table>(state);
 #endif // LUA_VERSION_NUM > 501
 
+
     for (unsigned char i = 1; i <= dbgInfo.nups; ++i) {
         const char* valueName = lua_getupvalue(state, -1, i); // push value on stack
         (void)valueName; // get rid of 'unused' warning for Lua5.1
         assert(valueName != nullptr);
 
 #if LUA_VERSION_NUM > 501
-        if (strcmp(valueName, "_ENV") == 0) { // do not serialize _ENV
+        if (gTable == sol::stack::get<sol::table>(state)) { // do not serialize _G
             sol::stack::pop<sol::object>(state);
             ctx_->envUpvaluePos = i;
             continue;
         }
 #endif // LUA_VERSION_NUM > 501
 
-        const auto& upvalue = sol::stack::pop<sol::object>(state); // pop from stack
-        if (!allowTableUpvalues() && upvalue.get_type() == sol::type::table) {
-            sol::stack::pop<sol::object>(state);
-            throw effil::Exception() << "bad function upvalue #" << (int)i << " (table is disabled by effil.allow_table_upvalues)";
-        }
-
         StoredObject storedObject;
         try {
+            const auto& upvalue = sol::stack::pop<sol::object>(state);
             storedObject = createStoredObject(upvalue);
             assert(storedObject.get() != nullptr);
         }
@@ -87,8 +64,8 @@ sol::object Function::loadFunction(lua_State* state) {
     for(size_t i = 0; i < ctx_->upvalues.size(); ++i) {
 #if LUA_VERSION_NUM > 501
         if (ctx_->envUpvaluePos == i + 1) {
-            lua_rawgeti(state, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS); // push _ENV to stack
-            lua_setupvalue(state, -2, i + 1); // pop _ENV and set as upvalue
+            lua_pushglobaltable(state); // push _G to stack
+            lua_setupvalue(state, -2, i + 1); // pop _G and set as upvalue
             continue;
         }
 #endif // LUA_VERSION_NUM > 501

src/cpp/function.h

@@ -7,8 +7,6 @@
 
 namespace effil {
 
-sol::object luaAllowTableUpvalues(sol::this_state state, const sol::stack_object&);
-
 class FunctionData : public GCData {
 public:
     std::string function;

src/cpp/lua-module.cpp

@@ -107,7 +107,6 @@ int luaopen_effil(lua_State* L) {
             "pairs",        SharedTable::globalLuaPairs,
             "ipairs",       SharedTable::globalLuaIPairs,
             "size",         luaSize,
-            "allow_table_upvalues",    luaAllowTableUpvalues,
             "hardware_threads",        std::thread::hardware_concurrency,
             sol::meta_function::index, luaIndex
     );

tests/lua/type_mismatch.lua

@@ -122,11 +122,6 @@ local function generate_tests()
             --  effil.gc.step
             test.type_mismatch.input_types_mismatch_p(1, "number", "gc.step", type_instance)
         end
-
-        if typename ~= "boolean" then
-            -- effil.allow_table_upvalue
-            test.type_mismatch.input_types_mismatch_p(1, "boolean", "allow_table_upvalues", type_instance)
-        end
     end
 
     -- Below presented tests which support everything except coroutines
@@ -155,6 +150,5 @@ end
 generate_tests()
 
 test.type_mismatch.gc_checks_after_tests = function()
-    effil.allow_table_upvalues(true)
     default_tear_down()
 end

tests/lua/upvalues.lua

@@ -60,7 +60,7 @@ test.upvalues.check_table = function()
     test.equal(ret, "effil.table: value")
 end
 
-test.upvalues.check_env = function()
+test.upvalues.check_global_env = function()
     local obj1 = 13 -- local
     obj2 = { key = "origin" } -- global
     local obj3 = 79 -- local
@@ -81,39 +81,19 @@ test.upvalues.check_env = function()
     test.equal(ret, "13, local, 79")
 end
 
-local function check_works(should_work)
-    local obj = { key = "value"}
-    local function worker()
-        return obj.key
+if LUA_VERSION > 51 then
+
+test.upvalues.check_custom_env = function()
+    local function create_foo()
+        local _ENV = { key = 'value' }
+        return function()
+            return key
+        end
     end
 
-    local ret, err = pcall(effil.thread(worker))
-    if ret then
-        err:wait()
-    end
-    test.equal(ret, should_work)
-    if not should_work then
-        test.equal(err, "effil.thread: bad function upvalue #1 (table is disabled by effil.allow_table_upvalues)")
-    end
+    local foo = create_foo()
+    local ret = effil.thread(foo)():get()
+    test.equal(ret, 'value')
 end
 
-test.upvalues_table.tear_down = function()
-    effil.allow_table_upvalues(true)
-    default_tear_down()
-end
-
-test.upvalues_table.disabling_table_upvalues = function()
-    test.equal(effil.allow_table_upvalues(), true)
-    -- works by default
-    check_works(true)
-
-    -- disable
-    test.equal(effil.allow_table_upvalues(false), true)
-    check_works(false)
-    test.equal(effil.allow_table_upvalues(), false)
-
-    -- enable back
-    test.equal(effil.allow_table_upvalues(true), false)
-    check_works(true)
-    test.equal(effil.allow_table_upvalues(), true)
-end
+end -- LUA_VERSION > 51