1 // Copyright 2020 The SwiftShader Authors. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #if defined(_MSVC_LANG) 16 # define CPP_VERSION _MSVC_LANG 17 #elif defined(__cplusplus) 18 // Note: This must come after checking for _MSVC_LANG. 19 // See https://developercommunity.visualstudio.com/content/problem/139261/msvc-incorrectly-defines-cplusplus.html 20 # define CPP_VERSION __cplusplus 21 #endif 22 23 #if !defined(CPP_VERSION) || CPP_VERSION <= 1 24 # error "Unable to identify C++ language version" 25 #endif 26 27 // The template and unused function below verifies the compiler is using at least 28 // C++17. It will print an error message containing the actual C++ version if 29 // the version is < 17. 30 31 namespace { 32 33 template<int version> 34 class cpp 35 { 36 static_assert(version >= 2017, "SwiftShader requires at least C++17"); 37 }; 38 check_cpp_version()39void check_cpp_version() 40 { 41 cpp<CPP_VERSION / 100>(); 42 (void)&check_cpp_version; // Unused reference to avoid unreferenced function warning. 43 } 44 45 } // namespace 46