1 //===--------- compiler.h - Compiler abstraction support --------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of the ORC runtime support library. 10 // 11 // Most functionality in this file was swiped from llvm/Support/Compiler.h. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef ORC_RT_COMPILER_H 16 #define ORC_RT_COMPILER_H 17 18 #define ORC_RT_INTERFACE extern "C" __attribute__((visibility("default"))) 19 #define ORC_RT_HIDDEN __attribute__((visibility("hidden"))) 20 21 #ifndef __has_builtin 22 # define __has_builtin(x) 0 23 #endif 24 25 // Only use __has_cpp_attribute in C++ mode. GCC defines __has_cpp_attribute in 26 // C mode, but the :: in __has_cpp_attribute(scoped::attribute) is invalid. 27 #ifndef ORC_RT_HAS_CPP_ATTRIBUTE 28 #if defined(__cplusplus) && defined(__has_cpp_attribute) 29 #define ORC_RT_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) 30 #else 31 #define ORC_RT_HAS_CPP_ATTRIBUTE(x) 0 32 #endif 33 #endif 34 35 // Use the 'nodiscard' attribute in C++17 or newer mode. 36 #if defined(__cplusplus) && __cplusplus > 201402L && \ 37 ORC_RT_HAS_CPP_ATTRIBUTE(nodiscard) 38 #define ORC_RT_NODISCARD [[nodiscard]] 39 #elif ORC_RT_HAS_CPP_ATTRIBUTE(clang::warn_unused_result) 40 #define ORC_RT_NODISCARD [[clang::warn_unused_result]] 41 // Clang in C++14 mode claims that it has the 'nodiscard' attribute, but also 42 // warns in the pedantic mode that 'nodiscard' is a C++17 extension (PR33518). 43 // Use the 'nodiscard' attribute in C++14 mode only with GCC. 44 // TODO: remove this workaround when PR33518 is resolved. 45 #elif defined(__GNUC__) && ORC_RT_HAS_CPP_ATTRIBUTE(nodiscard) 46 #define ORC_RT_NODISCARD [[nodiscard]] 47 #else 48 #define ORC_RT_NODISCARD 49 #endif 50 51 #if __has_builtin(__builtin_expect) 52 #define ORC_RT_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true) 53 #define ORC_RT_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false) 54 #else 55 #define ORC_RT_LIKELY(EXPR) (EXPR) 56 #define ORC_RT_UNLIKELY(EXPR) (EXPR) 57 #endif 58 59 #ifdef __APPLE__ 60 #define ORC_RT_WEAK_IMPORT __attribute__((weak_import)) 61 #else 62 #define ORC_RT_WEAK_IMPORT __attribute__((weak)) 63 #endif 64 65 #endif // ORC_RT_COMPILER_H 66