| // Copyright 2019 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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. |
| // |
| // Small, general preprocessor macros for C and C++ code. |
| #pragma once |
| |
| // Returns the number of elements in a C array. |
| #define PW_ARRAY_SIZE(array) (sizeof(array) / sizeof(*array)) |
| |
| // Returns a string literal of the arguments after expanding macros. |
| #define PW_STRINGIFY(...) _PW_STRINGIFY(__VA_ARGS__) |
| #define _PW_STRINGIFY(...) #__VA_ARGS__ |
| |
| #ifdef __cplusplus |
| |
| // Macro for inline extern "C" declarations. The following will compile |
| // correctly for C and C++: |
| // |
| // PW_EXTERN_C ThisFunctionHasCLinkage(void); |
| // |
| #define PW_EXTERN_C extern "C" |
| |
| // Macros for opening and closing an extern "C" block. This avoids the need for |
| // an #ifdef __cplusplus check around the extern "C" { and closing }. Example: |
| // |
| // PW_EXTERN_C_START |
| // |
| // void FunctionDeclarationForCppAndC(void); |
| // |
| // void AnotherFunctionDeclarationForCppAndC(int, char); |
| // |
| // PW_EXTERN_C_END |
| // |
| #define PW_EXTERN_C_START extern "C" { |
| #define PW_EXTERN_C_END } // extern "C" |
| |
| #else // extern "C" is removed from C code |
| |
| #define PW_EXTERN_C |
| #define PW_EXTERN_C_START |
| #define PW_EXTERN_C_END |
| |
| #endif // __cplusplus |
