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