| //===-- Portable attributes -------------------------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // This header file defines a set of macros for checking the presence of |
| // important compiler and platform features. Such macros can be used to |
| // produce portable code by parameterizing compilation based on the presence or |
| // lack of a given feature. |
| |
| #ifndef LLVM_LIBC_SUPPORT_MACROS_CONFIG_H |
| #define LLVM_LIBC_SUPPORT_MACROS_CONFIG_H |
| |
| // LIBC_HAS_BUILTIN() |
| // |
| // Checks whether the compiler supports a Clang Feature Checking Macro, and if |
| // so, checks whether it supports the provided builtin function "x" where x |
| // is one of the functions noted in |
| // https://clang.llvm.org/docs/LanguageExtensions.html |
| // |
| // Note: Use this macro to avoid an extra level of #ifdef __has_builtin check. |
| // http://releases.llvm.org/3.3/tools/clang/docs/LanguageExtensions.html |
| |
| // Compiler builtin-detection. |
| // clang.llvm.org/docs/LanguageExtensions.html#has-builtin |
| #ifdef __has_builtin |
| #define LIBC_HAS_BUILTIN(x) __has_builtin(x) |
| #else |
| #define LIBC_HAS_BUILTIN(x) 0 |
| #endif |
| |
| // Compiler feature-detection. |
| // clang.llvm.org/docs/LanguageExtensions.html#has-feature-and-has-extension |
| #ifdef __has_feature |
| #define LIBC_HAS_FEATURE(f) __has_feature(f) |
| #else |
| #define LIBC_HAS_FEATURE(f) 0 |
| #endif |
| |
| #endif // LLVM_LIBC_SUPPORT_MACROS_CONFIG_H |
