Lua API: add return types to table getters (#389)

Co-authored-by: Petri Häkkinen <petrih@rmd.remedy.fi>

VM/include/lua.h

@@ -178,11 +178,11 @@ LUA_API int lua_pushthread(lua_State* L);
 /*
 ** get functions (Lua -> stack)
 */
-LUA_API void lua_gettable(lua_State* L, int idx);
+LUA_API int lua_gettable(lua_State* L, int idx);
-LUA_API void lua_getfield(lua_State* L, int idx, const char* k);
+LUA_API int lua_getfield(lua_State* L, int idx, const char* k);
-LUA_API void lua_rawgetfield(lua_State* L, int idx, const char* k);
+LUA_API int lua_rawgetfield(lua_State* L, int idx, const char* k);
-LUA_API void lua_rawget(lua_State* L, int idx);
+LUA_API int lua_rawget(lua_State* L, int idx);
-LUA_API void lua_rawgeti(lua_State* L, int idx, int n);
+LUA_API int lua_rawgeti(lua_State* L, int idx, int n);
 LUA_API void lua_createtable(lua_State* L, int narr, int nrec);
 
 LUA_API void lua_setreadonly(lua_State* L, int idx, int enabled);

VM/src/lapi.cpp

@@ -659,16 +659,16 @@ int lua_pushthread(lua_State* L)
 ** get functions (Lua -> stack)
 */
 
-void lua_gettable(lua_State* L, int idx)
+int lua_gettable(lua_State* L, int idx)
 {
     luaC_checkthreadsleep(L);
     StkId t = index2addr(L, idx);
     api_checkvalidindex(L, t);
     luaV_gettable(L, t, L->top - 1, L->top - 1);
-    return;
+    return ttype(L->top - 1);
 }
 
-void lua_getfield(lua_State* L, int idx, const char* k)
+int lua_getfield(lua_State* L, int idx, const char* k)
 {
     luaC_checkthreadsleep(L);
     StkId t = index2addr(L, idx);
@@ -677,10 +677,10 @@ void lua_getfield(lua_State* L, int idx, const char* k)
     setsvalue(L, &key, luaS_new(L, k));
     luaV_gettable(L, t, &key, L->top);
     api_incr_top(L);
-    return;
+    return ttype(L->top - 1);
 }
 
-void lua_rawgetfield(lua_State* L, int idx, const char* k)
+int lua_rawgetfield(lua_State* L, int idx, const char* k)
 {
     luaC_checkthreadsleep(L);
     StkId t = index2addr(L, idx);
@@ -689,26 +689,26 @@ void lua_rawgetfield(lua_State* L, int idx, const char* k)
     setsvalue(L, &key, luaS_new(L, k));
     setobj2s(L, L->top, luaH_getstr(hvalue(t), tsvalue(&key)));
     api_incr_top(L);
-    return;
+    return ttype(L->top - 1);
 }
 
-void lua_rawget(lua_State* L, int idx)
+int lua_rawget(lua_State* L, int idx)
 {
     luaC_checkthreadsleep(L);
     StkId t = index2addr(L, idx);
     api_check(L, ttistable(t));
     setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1));
-    return;
+    return ttype(L->top - 1);
 }
 
-void lua_rawgeti(lua_State* L, int idx, int n)
+int lua_rawgeti(lua_State* L, int idx, int n)
 {
     luaC_checkthreadsleep(L);
     StkId t = index2addr(L, idx);
     api_check(L, ttistable(t));
     setobj2s(L, L->top, luaH_getnum(hvalue(t), n));
     api_incr_top(L);
-    return;
+    return ttype(L->top - 1);
 }
 
 void lua_createtable(lua_State* L, int narray, int nrec)

tests/Conformance.test.cpp

@@ -712,6 +712,47 @@ TEST_CASE("Reference")
     CHECK(dtorhits == 2);
 }
 
+TEST_CASE("ApiTables")
+{
+    StateRef globalState(luaL_newstate(), lua_close);
+    lua_State* L = globalState.get();
+
+    lua_newtable(L);
+    lua_pushnumber(L, 123.0);
+    lua_setfield(L, -2, "key");
+    lua_pushstring(L, "test");
+    lua_rawseti(L, -2, 5);
+
+    // lua_gettable
+    lua_pushstring(L, "key");
+    CHECK(lua_gettable(L, -2) == LUA_TNUMBER);
+    CHECK(lua_tonumber(L, -1) == 123.0);
+    lua_pop(L, 1);
+
+    // lua_getfield
+    CHECK(lua_getfield(L, -1, "key") == LUA_TNUMBER);
+    CHECK(lua_tonumber(L, -1) == 123.0);
+    lua_pop(L, 1);
+
+    // lua_rawgetfield
+    CHECK(lua_rawgetfield(L, -1, "key") == LUA_TNUMBER);
+    CHECK(lua_tonumber(L, -1) == 123.0);
+    lua_pop(L, 1);
+
+    // lua_rawget
+    lua_pushstring(L, "key");
+    CHECK(lua_rawget(L, -2) == LUA_TNUMBER);
+    CHECK(lua_tonumber(L, -1) == 123.0);
+    lua_pop(L, 1);
+
+    // lua_rawgeti
+    CHECK(lua_rawgeti(L, -1, 5) == LUA_TSTRING);
+    CHECK(strcmp(lua_tostring(L, -1), "test") == 0);
+    lua_pop(L, 1);
+
+    lua_pop(L, 1);
+}
+
 TEST_CASE("ApiFunctionCalls")
 {
     StateRef globalState = runConformance("apicalls.lua");