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 #if defined(_WIN32) 19 #define ORC_RT_INTERFACE extern "C" 20 #define ORC_RT_HIDDEN 21 #define ORC_RT_IMPORT extern "C" __declspec(dllimport) 22 #else 23 #define ORC_RT_INTERFACE extern "C" __attribute__((visibility("default"))) 24 #define ORC_RT_HIDDEN __attribute__((visibility("hidden"))) 25 #define ORC_RT_IMPORT extern "C" 26 #endif 27 28 #ifndef __has_builtin 29 # define __has_builtin(x) 0 30 #endif 31 32 // Only use __has_cpp_attribute in C++ mode. GCC defines __has_cpp_attribute in 33 // C mode, but the :: in __has_cpp_attribute(scoped::attribute) is invalid. 34 #ifndef ORC_RT_HAS_CPP_ATTRIBUTE 35 #if defined(__cplusplus) && defined(__has_cpp_attribute) 36 #define ORC_RT_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) 37 #else 38 #define ORC_RT_HAS_CPP_ATTRIBUTE(x) 0 39 #endif 40 #endif 41 42 // Use the 'nodiscard' attribute in C++17 or newer mode. 43 #if defined(__cplusplus) && __cplusplus > 201402L && \ 44 ORC_RT_HAS_CPP_ATTRIBUTE(nodiscard) 45 #define ORC_RT_NODISCARD [[nodiscard]] 46 #elif ORC_RT_HAS_CPP_ATTRIBUTE(clang::warn_unused_result) 47 #define ORC_RT_NODISCARD [[clang::warn_unused_result]] 48 // Clang in C++14 mode claims that it has the 'nodiscard' attribute, but also 49 // warns in the pedantic mode that 'nodiscard' is a C++17 extension (PR33518). 50 // Use the 'nodiscard' attribute in C++14 mode only with GCC. 51 // TODO: remove this workaround when PR33518 is resolved. 52 #elif defined(__GNUC__) && ORC_RT_HAS_CPP_ATTRIBUTE(nodiscard) 53 #define ORC_RT_NODISCARD [[nodiscard]] 54 #else 55 #define ORC_RT_NODISCARD 56 #endif 57 58 #if __has_builtin(__builtin_expect) 59 #define ORC_RT_LIKELY(EXPR) __builtin_expect((bool)(EXPR), true) 60 #define ORC_RT_UNLIKELY(EXPR) __builtin_expect((bool)(EXPR), false) 61 #else 62 #define ORC_RT_LIKELY(EXPR) (EXPR) 63 #define ORC_RT_UNLIKELY(EXPR) (EXPR) 64 #endif 65 66 #if defined(__APPLE__) 67 #define ORC_RT_WEAK_IMPORT __attribute__((weak_import)) 68 #elif defined(_WIN32) 69 #define ORC_RT_WEAK_IMPORT 70 #else 71 #define ORC_RT_WEAK_IMPORT __attribute__((weak)) 72 #endif 73 74 #endif // ORC_RT_COMPILER_H 75