From 6896ff9de7e7e8d8db569b594e9b493d3e4f8122 Mon Sep 17 00:00:00 2001 From: Dominik Gabi Date: Wed, 23 Dec 2015 15:43:24 -0800 Subject: [PATCH] clang attribute wrappers Summary: adding GCC compatible wrappers for clang attributes to folly. Reviewed By: yfeldblum Differential Revision: D2706913 fb-gh-sync-id: 17db34089d48a6a01c20904321a47ff98141c2fe --- folly/CppAttributes.h | 51 +++++++++++++++++++++++++++++++++++++++++++ folly/Makefile.am | 1 + 2 files changed, 52 insertions(+) create mode 100644 folly/CppAttributes.h diff --git a/folly/CppAttributes.h b/folly/CppAttributes.h new file mode 100644 index 00000000..4a001946 --- /dev/null +++ b/folly/CppAttributes.h @@ -0,0 +1,51 @@ +/* + * Copyright 2015 Facebook, Inc. + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * GCC compatible wrappers around clang attributes. + * + * @author Dominik Gabi + */ + +#ifndef FOLLY_BASE_ATTRIBUTES_H_ +#define FOLLY_BASE_ATTRIBUTES_H_ + +#ifndef __has_cpp_attribute +#define FOLLY_HAS_CPP_ATTRIBUTE(x) 0 +#else +#define FOLLY_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x) +#endif + +/** + * Fallthrough to indicate that `break` was left out on purpose in a switch + * statement, e.g. + * + * switch (n) { + * case 22: + * case 33: // no warning: no statements between case labels + * f(); + * case 44: // warning: unannotated fall-through + * g(); + * FOLLY_FALLTHROUGH; // no warning: annotated fall-through + * } + */ +#if FOLLY_HAS_CPP_ATTRIBUTE(clang::fallthrough) +#define FOLLY_FALLTHROUGH [[clang::fallthrough]] +#else +#define FOLLY_FALLTHROUGH +#endif + +#endif /* FOLLY_BASE_ATTRIBUTES_H_ */ diff --git a/folly/Makefile.am b/folly/Makefile.am index f40fc12a..92967640 100644 --- a/folly/Makefile.am +++ b/folly/Makefile.am @@ -30,6 +30,7 @@ nobase_follyinclude_HEADERS = \ AtomicLinkedList.h \ AtomicStruct.h \ AtomicUnorderedMap.h \ + CppAttributes.h \ Baton.h \ Benchmark.h \ Bits.h \ -- 2.34.1