New compatibility helper luaG_rawget

6 files changed, 55 insertions, 40 deletions

diff --git a/src/compat.hpp b/src/compat.hpp
index d864ae9..9a8dedf 100644
--- a/src/compat.hpp
+++ b/src/compat.hpp
@@ -271,6 +271,7 @@ static inline int WrapLuaGetField(LUA_GETFIELD f_, lua_State* const L_, StackInd
 
 // -------------------------------------------------------------------------------------------------
 
+[[nodiscard]]
 static inline LuaType luaG_getfield(lua_State* const L_, StackIndex const idx_, std::string_view const& name_)
 {
     return static_cast<LuaType>(WrapLuaGetField(lua_getfield, L_, idx_, name_));
@@ -278,6 +279,7 @@ static inline LuaType luaG_getfield(lua_State* const L_, StackIndex const idx_,
 
 // #################################################################################################
 
+[[nodiscard]]
 LuaType luaG_getmodule(lua_State* L_, std::string_view const& name_);
 
 // #################################################################################################
@@ -350,6 +352,7 @@ static inline int WrapLuaResume(LUA_RESUME const lua_resume_, lua_State* const L
 
 // -------------------------------------------------------------------------------------------------
 
+[[nodiscard]]
 static inline LuaError luaG_resume(lua_State* const L_, lua_State* const from_, int const nargs_, int* const nresults_)
 {
     return ToLuaError(WrapLuaResume(lua_resume, L_, from_, nargs_, nresults_));
@@ -357,6 +360,38 @@ static inline LuaError luaG_resume(lua_State* const L_, lua_State* const from_,
 
 // #################################################################################################
 
+template <typename LUA_RAWGET>
+concept RequiresOldLuaRawget = requires(LUA_RAWGET f_) { { f_(nullptr, 0) } -> std::same_as<void>; };
+
+template <RequiresOldLuaRawget LUA_RAWGET>
+static inline LuaType WrapLuaRawget(LUA_RAWGET lua_rawget_, lua_State* const L_, StackIndex const idx_)
+{
+    // until Lua 5.3, lua_rawget -> void
+    lua_rawget_(L_, idx_);
+    return luaG_type(L_, kIdxTop);
+}
+
+// -------------------------------------------------------------------------------------------------
+
+template <typename LUA_RAWGET>
+concept RequiresNewLuaRawget = requires(LUA_RAWGET f_) { { f_(nullptr, 0) } -> std::same_as<int>; };
+
+template <RequiresNewLuaRawget LUA_RAWGET>
+static inline LuaType WrapLuaRawget(LUA_RAWGET lua_rawget_, lua_State* const L_, StackIndex const idx_)
+{
+    // starting with Lua 5.3, lua_rawget -> int (the type of the extracted value)
+    return static_cast<LuaType>(lua_rawget_(L_, idx_));
+}
+
+// -------------------------------------------------------------------------------------------------
+
+static inline LuaType luaG_rawget(lua_State* const L_, StackIndex const idx_)
+{
+    return WrapLuaRawget(lua_rawget, L_, idx_);
+}
+
+// #################################################################################################
+
 static inline LuaType luaG_rawgetfield(lua_State* const L_, StackIndex const idx_, std::string_view const& name_)
 {
     auto const _absIdx{ luaG_absindex(L_, idx_) };
diff --git a/src/deep.cpp b/src/deep.cpp
index c1ef30e..82f1214 100644
--- a/src/deep.cpp
+++ b/src/deep.cpp
@@ -190,8 +190,7 @@ void DeepFactory::PushDeepProxy(DestState const L_, DeepPrelude* const prelude_,
 
     // Check if a proxy already exists
     lua_pushlightuserdata(L_, prelude_);                                                           // L_: DPC deep
-    lua_rawget(L_, -2);                                                                            // L_: DPC proxy
-    if (!lua_isnil(L_, -1)) {
+    if (luaG_rawget(L_, StackIndex{ -2 }) != LuaType::NIL) {                                       // L_: DPC proxy
         lua_remove(L_, -2);                                                                        // L_: proxy
         STACK_CHECK(L_, 1);
         return;
diff --git a/src/intercopycontext.cpp b/src/intercopycontext.cpp
index da4340e..d6716a3 100644
--- a/src/intercopycontext.cpp
+++ b/src/intercopycontext.cpp
@@ -337,10 +337,9 @@ void InterCopyContext::lookupNativeFunction() const
         STACK_CHECK(L2, 1);
         LUA_ASSERT(L1, lua_istable(L2, -1));
         luaG_pushstring(L2, _fqn);                                                                 // L1: ... f ...                                  L2: {} "f.q.n"
-        lua_rawget(L2, -2);                                                                        // L1: ... f ...                                  L2: {} f
+        LuaType const _objType{ luaG_rawget(L2, StackIndex{ -2 }) };                               // L1: ... f ...                                  L2: {} f
         // nil means we don't know how to transfer stuff: user should do something
         // anything other than function or table should not happen!
-        LuaType const _objType{ luaG_type(L2, kIdxTop) };
         if (_objType != LuaType::FUNCTION && _objType != LuaType::TABLE && _objType != LuaType::USERDATA) {
             kLaneNameRegKey.pushValue(L1);                                                         // L1: ... f ... lane_name
             std::string_view const _from{ luaG_tostring(L1, kIdxTop) };
@@ -390,9 +389,7 @@ void InterCopyContext::copyCachedFunction() const
         //DEBUGSPEW_CODE(DebugSpew(U) << "<< ID: " << luaG_tostring(L2, -1) << " >>" << std::endl);
 
         lua_pushvalue(L2, -1);                                                                     //                                                L2: ... {cache} ... p p
-        lua_rawget(L2, L2_cache_i);                                                                //                                                L2: ... {cache} ... p function|nil|true
-
-        if (lua_isnil(L2, -1)) { // function is unknown
+        if (luaG_rawget(L2, L2_cache_i) == LuaType::NIL) { // function is unknown                  //                                                L2: ... {cache} ... p function|nil|true
             lua_pop(L2, 1);                                                                        //                                                L2: ... {cache} ... p
 
             // Set to 'true' for the duration of creation; need to find self-references
@@ -443,10 +440,9 @@ bool InterCopyContext::lookupTable() const
         STACK_CHECK(L2, 1);
         LUA_ASSERT(L1, lua_istable(L2, -1));
         luaG_pushstring(L2, _fqn);                                                                 //                                                L2: {} "f.q.n"
-        lua_rawget(L2, -2);                                                                        //                                                L2: {} t
         // we accept destination lookup failures in the case of transfering the Lanes body function (this will result in the source table being cloned instead)
         // but not when we extract something out of a keeper, as there is nothing to clone!
-        if (lua_isnil(L2, -1) && mode == LookupMode::LaneBody) {
+        if (luaG_rawget(L2, StackIndex{ -2 }) == LuaType::NIL && mode == LookupMode::LaneBody) {   //                                                L2: {} t
             lua_pop(L2, 2);                                                                        // L1: ... t ...                                  L2:
             STACK_CHECK(L2, 0);
             return false;
@@ -619,10 +615,7 @@ bool InterCopyContext::pushCachedMetatable() const
     // do we already know this metatable?
     std::ignore = kMtIdRegKey.getSubTable(L2, NArr{ 0 }, NRec{ 0 });                               //                                                L2: _R[kMtIdRegKey]
     lua_pushinteger(L2, _mt_id);                                                                   //                                                L2: _R[kMtIdRegKey] id
-    lua_rawget(L2, -2);                                                                            //                                                L2: _R[kMtIdRegKey] mt|nil
-    STACK_CHECK(L2, 2);
-
-    if (lua_isnil(L2, -1)) { // L2 did not know the metatable
+    if (luaG_rawget(L2, StackIndex{ -2 }) == LuaType::NIL) { // L2 did not know the metatable      //                                                L2: _R[kMtIdRegKey] mt|nil
         lua_pop(L2, 1);                                                                            //                                                L2: _R[kMtIdRegKey]
         InterCopyContext const _c{ U, L2, L1, L2_cache_i, SourceIndex{ lua_gettop(L1) }, VT::METATABLE, mode, name };
         if (_c.interCopyOne() != InterCopyResult::Success) {                                       //                                                L2: _R[kMtIdRegKey] mt?
@@ -671,8 +664,7 @@ bool InterCopyContext::pushCachedTable() const
 
     //DEBUGSPEW_CODE(DebugSpew(U) << "<< ID: " << luaG_tostring(L2, -1) << " >>" << std::endl);
 
-    lua_rawget(L2, L2_cache_i);                                                                    // L1: ... t ...                                  L2: ... {cached|nil}
-    bool const _not_found_in_cache{ lua_isnil(L2, -1) };
+    bool const _not_found_in_cache{ luaG_rawget(L2, L2_cache_i) == LuaType::NIL };                 // L1: ... t ...                                  L2: ... {cached|nil}
     if (_not_found_in_cache) {
         // create a new entry in the cache
         lua_pop(L2, 1);                                                                            // L1: ... t ...                                  L2: ...
@@ -714,10 +706,10 @@ bool InterCopyContext::lookupUserdata() const
         STACK_CHECK(L2, 1);
         LUA_ASSERT(L1, lua_istable(L2, -1));
         luaG_pushstring(L2, _fqn);                                                                 // L1: ... f ...                                  L2: {} "f.q.n"
-        lua_rawget(L2, -2);                                                                        // L1: ... f ...                                  L2: {} f
+        LuaType const _type{ luaG_rawget(L2, StackIndex{ -2 }) };                                  // L1: ... f ...                                  L2: {} f
         // nil means we don't know how to transfer stuff: user should do something
         // anything other than function or table should not happen!
-        if (!lua_isfunction(L2, -1) && !lua_istable(L2, -1)) {
+        if (_type != LuaType::FUNCTION && _type != LuaType::TABLE) {
             kLaneNameRegKey.pushValue(L1);                                                         // L1: ... f ... lane_name
             std::string_view const _from{ luaG_tostring(L1, kIdxTop) };
             lua_pop(L1, 1);                                                                        // L1: ... f ...
@@ -752,8 +744,7 @@ bool InterCopyContext::tryCopyClonable() const
 
     // Check if the source was already cloned during this copy
     lua_pushlightuserdata(L2, _source);                                                            //                                                L2: ... source
-    lua_rawget(L2, L2_cache_i);                                                                    //                                                L2: ... clone?
-    if (!lua_isnil(L2, -1)) {
+    if (luaG_rawget(L2, L2_cache_i) != LuaType::NIL) {                                             //                                                L2: ... clone?
         STACK_CHECK(L2, 1);
         return true;
     } else {
@@ -920,8 +911,7 @@ bool InterCopyContext::interCopyFunction() const
         lua_getupvalue(L1, L1_i, 2);                                                               // L1: ... u
         void* _source{ lua_touserdata(L1, -1) };
         lua_pushlightuserdata(L2, _source);                                                        //                                                L2: ... source
-        lua_rawget(L2, L2_cache_i);                                                                //                                                L2: ... u?
-        if (!lua_isnil(L2, -1)) {
+        if (luaG_rawget(L2, L2_cache_i) != LuaType::NIL) {                                         //                                                L2: ... u?
             lua_pop(L1, 1);                                                                        // L1: ...
             STACK_CHECK(L1, 0);
             STACK_CHECK(L2, 1);
diff --git a/src/keeper.cpp b/src/keeper.cpp
index 43f3125..cad9207 100644
--- a/src/keeper.cpp
+++ b/src/keeper.cpp
@@ -315,9 +315,7 @@ static void PushKeysDB(KeeperState const K_, StackIndex const idx_)
     StackIndex const _absidx{ luaG_absindex(K_, idx_) };
     kLindasRegKey.pushValue(K_);                                                                   // K_: ... LindasDB
     lua_pushvalue(K_, _absidx);                                                                    // K_: ... LindasDB linda
-    lua_rawget(K_, -2);                                                                            // K_: ... LindasDB KeysDB
-    STACK_CHECK(K_, 2);
-    if (lua_isnil(K_, -1)) {
+    if (luaG_rawget(K_, StackIndex{ -2 }) == LuaType::NIL) {                                       // K_: ... LindasDB KeysDB
         lua_pop(K_, 1);                                                                            // K_: ... LindasDB
         // add a new KeysDB table for this linda
         lua_newtable(K_);                                                                          // K_: ... LindasDB KeysDB
@@ -372,8 +370,7 @@ int keepercall_count(lua_State* const L_)
     case 2:                                                                                        // _K: linda key
         PushKeysDB(_K, StackIndex{ 1 });                                                           // _K: linda key KeysDB
         lua_replace(_K, 1);                                                                        // _K: KeysDB key
-        lua_rawget(_K, -2);                                                                        // _K: KeysDB KeyUD|nil
-        if (lua_isnil(_K, -1)) { // the key is unknown                                             // _K: KeysDB nil
+        if (luaG_rawget(_K, StackIndex{ -2 }) == LuaType::NIL) { // the key is unknown             // _K: KeysDB KeyUD|nil
             lua_remove(_K, -2);                                                                    // _K: nil
         } else { // the key is known                                                               // _K: KeysDB KeyUD
             KeyUD* const _key{ KeyUD::GetPtr(_K, kIdxTop) };
@@ -656,8 +653,7 @@ int keepercall_send(lua_State* const L_)
     PushKeysDB(_K, StackIndex{ 1 });                                                               // _K: linda key val... KeysDB
     // get the fifo associated to this key in this linda, create it if it doesn't exist
     lua_pushvalue(_K, 2);                                                                          // _K: linda key val... KeysDB key
-    lua_rawget(_K, -2);                                                                            // _K: linda key val... KeysDB KeyUD|nil
-    if (lua_isnil(_K, -1)) {
+    if (luaG_rawget(_K, StackIndex{ -2 }) == LuaType::NIL) {                                       // _K: linda key val... KeysDB KeyUD|nil
         lua_pop(_K, 1);                                                                            // _K: linda key val... KeysDB
         std::ignore = KeyUD::Create(KeeperState{ _K });                                            // _K: linda key val... KeysDB KeyUD
         // KeysDB[key] = KeyUD
@@ -853,9 +849,9 @@ int Keeper::PushLindaStorage(Linda& linda_, DestState const L_)
     STACK_CHECK_START_REL(_K, 0);
     kLindasRegKey.pushValue(_K);                                                                   // _K: LindasDB                                       L_:
     lua_pushlightuserdata(_K, &linda_);                                                            // _K: LindasDB linda                                 L_:
-    lua_rawget(_K, -2);                                                                            // _K: LindasDB KeysDB                                L_:
+    LuaType const _type{ luaG_rawget(_K, StackIndex{ -2 }) };                                      // _K: LindasDB KeysDB                                L_:
     lua_remove(_K, -2);                                                                            // _K: KeysDB                                         L_:
-    if (!lua_istable(_K, -1)) { // possible if we didn't send anything through that linda
+    if (_type != LuaType::TABLE) { // possible if we didn't send anything through that linda
         lua_pop(_K, 1);                                                                            // _K:                                                L_:
         STACK_CHECK(_K, 0);
         return 0;
diff --git a/src/lane.cpp b/src/lane.cpp
index 5b05b4e..7a5c257 100644
--- a/src/lane.cpp
+++ b/src/lane.cpp
@@ -298,8 +298,7 @@ static int lane_index_string(lua_State* L_)
     // look in metatable first
     lua_getmetatable(L_, kIdxSelf);                                                                // L_: lane "key" mt
     lua_replace(L_, -3);                                                                           // L_: mt "key"
-    lua_rawget(L_, -2);                                                                            // L_: mt value
-    if (luaG_type(L_, kIdxTop) != LuaType::NIL) { // found something?
+    if (luaG_rawget(L_, StackIndex{ -2 }) != LuaType::NIL) { // found something?                   // L_: mt value
         return 1; // done
     }
 
@@ -335,14 +334,12 @@ static LUAG_FUNC(lane_index)
     default: // unknown key
         lua_getmetatable(L_, kIdxSelf);                                                            // L_: mt
         kCachedError.pushKey(L_);                                                                  // L_: mt kCachedError
-        lua_rawget(L_, -2);                                                                        // L_: mt error()
-        if (luaG_type(L_, kIdxTop) != LuaType::FUNCTION) {
+        if (luaG_rawget(L_, StackIndex{ -2 }) != LuaType::FUNCTION) {                              // L_: mt error()
             raise_luaL_error(L_, "INTERNAL ERROR: cached error() is a %s, not a function", luaG_typename(L_, kIdxTop).data());
         }
         luaG_pushstring(L_, "Unknown key: ");                                                      // L_: mt error() "Unknown key: "
         kCachedTostring.pushKey(L_);                                                               // L_: mt error() "Unknown key: " kCachedTostring
-        lua_rawget(L_, -4);                                                                        // L_: mt error() "Unknown key: " tostring()
-        if (luaG_type(L_, kIdxTop) != LuaType::FUNCTION) {
+        if (luaG_rawget(L_, StackIndex{ -4 }) != LuaType::FUNCTION) {                              // L_: mt error() "Unknown key: " tostring()
             raise_luaL_error(L_, "INTERNAL ERROR: cached tostring() is a %s, not a function", luaG_typename(L_, kIdxTop).data());
         }
         lua_pushvalue(L_, kKey);                                                                   // L_: mt error() "Unknown key: " tostring() k
@@ -840,8 +837,7 @@ static LUAG_FUNC(lane_gc)
     // if there a gc callback?
     lua_getiuservalue(L_, StackIndex{ 1 }, UserValueIndex{ 1 });                                   // L_: ud uservalue
     kLaneGC.pushKey(L_);                                                                           // L_: ud uservalue __gc
-    lua_rawget(L_, -2);                                                                            // L_: ud uservalue gc_cb|nil
-    if (!lua_isnil(L_, -1)) {
+    if (luaG_rawget(L_, StackIndex{ -2 }) != LuaType::NIL) {                                       // L_: ud uservalue gc_cb|nil
         lua_remove(L_, -2);                                                                        // L_: ud gc_cb|nil
         luaG_pushstring(L_, _lane->getDebugName());                                                // L_: ud gc_cb name
         _have_gc_cb = true;
diff --git a/src/linda.cpp b/src/linda.cpp
index 4f33899..a094a8f 100644
--- a/src/linda.cpp
+++ b/src/linda.cpp
@@ -417,8 +417,7 @@ static int linda_index_string(lua_State* L_)
     // look in metatable first
     lua_getmetatable(L_, kIdxSelf);                                                                // L_: linda "key" mt
     lua_replace(L_, -3);                                                                           // L_: mt "key"
-    lua_rawget(L_, -2);                                                                            // L_: mt value
-    if (luaG_type(L_, kIdxTop) != LuaType::NIL) { // found something?
+    if (luaG_rawget(L_, StackIndex{ -2 }) != LuaType::NIL) { // found something?                   // L_: mt value
         return 1; // done
     }