1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 // Various macros related to function inlining. 18 19 #ifndef NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_BASE_ATTRIBUTES_H_ 20 #define NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_BASE_ATTRIBUTES_H_ 21 22 // SAFTM_HAVE_ATTRIBUTE 23 // 24 // A function-like feature checking macro that is a wrapper around 25 // `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a 26 // nonzero constant integer if the attribute is supported or 0 if not. 27 // 28 // It evaluates to zero if `__has_attribute` is not defined by the compiler. 29 // 30 // GCC: https://gcc.gnu.org/gcc-5/changes.html 31 // Clang: https://clang.llvm.org/docs/LanguageExtensions.html 32 #ifdef __has_attribute 33 #define SAFTM_HAVE_ATTRIBUTE(x) __has_attribute(x) 34 #else 35 #define SAFTM_HAVE_ATTRIBUTE(x) 0 36 #endif 37 38 // SAFTM_MUST_USE_RESULT 39 // 40 // Tells the compiler to warn about unused return values for functions declared 41 // with this macro. The macro must appear as the very first part of a function 42 // declaration or definition: 43 // 44 // Example: 45 // 46 // SAFTM_MUST_USE_RESULT Sprocket* AllocateSprocket(); 47 // 48 // This placement has the broadest compatibility with GCC, Clang, and MSVC, with 49 // both defs and decls, and with GCC-style attributes, MSVC declspec, C++11 50 // and C++17 attributes. 51 // 52 // SAFTM_MUST_USE_RESULT allows using cast-to-void to suppress the unused result 53 // warning. For that, warn_unused_result is used only for clang but not for gcc. 54 // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66425 55 #if SAFTM_HAVE_ATTRIBUTE(nodiscard) 56 #define SAFTM_MUST_USE_RESULT [[nodiscard]] 57 #elif defined(__clang__) && SAFTM_HAVE_ATTRIBUTE(warn_unused_result) 58 #define SAFTM_MUST_USE_RESULT __attribute__((warn_unused_result)) 59 #else 60 #define SAFTM_MUST_USE_RESULT 61 #endif 62 63 #if defined(__GNUC__) && \ 64 (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)) 65 66 // For functions we want to force inline. 67 // Introduced in gcc 3.1. 68 #define SAFTM_ATTRIBUTE_ALWAYS_INLINE __attribute__((always_inline)) 69 70 // For functions we don't want to inline, e.g., to keep code size small. 71 #define SAFTM_ATTRIBUTE_NOINLINE __attribute__((noinline)) 72 73 #elif defined(_MSC_VER) 74 #define SAFTM_ATTRIBUTE_ALWAYS_INLINE __forceinline 75 #else 76 77 // Other compilers will have to figure it out for themselves. 78 #define SAFTM_ATTRIBUTE_ALWAYS_INLINE 79 #define SAFTM_ATTRIBUTE_NOINLINE 80 #endif // big condition on two lines. 81 82 #endif // NLP_SAFT_COMPONENTS_COMMON_MOBILE_LITE_BASE_ATTRIBUTES_H_ 83
