esp-idf/components/esp_common/include/esp_compiler.h
Angus Gratton e3b7337f03 esp_common: Don't redefine likely/unlikely if already defined
As these macros aren't namespaced, they may have been defined by another header.

Also reported in https://github.com/espressif/esp-idf/issues/6445
2021-02-12 15:30:24 +11:00

60 lines
2.0 KiB
C

// Copyright 2016-2019 Espressif Systems (Shanghai) PTE LTD
//
// 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.
#ifndef __ESP_COMPILER_H
#define __ESP_COMPILER_H
/*
* The likely and unlikely macro pairs:
* These macros are useful to place when application
* knows the majority ocurrence of a decision paths,
* placing one of these macros can hint the compiler
* to reorder instructions producing more optimized
* code.
*/
#if (CONFIG_COMPILER_OPTIMIZATION_PERF)
#ifndef likely
#define likely(x) __builtin_expect(!!(x), 1)
#endif
#ifndef unlikely
#define unlikely(x) __builtin_expect(!!(x), 0)
#endif
#else
#ifndef likely
#define likely(x) (x)
#endif
#ifndef unlikely
#define unlikely(x) (x)
#endif
#endif
/*
* Utility macros used for designated initializers, which work differently
* in C99 and C++ standards mainly for aggregate types.
* The member separator, comma, is already part of the macro, please omit the trailing comma.
* Usage example:
* struct config_t { char* pchr; char arr[SIZE]; } config = {
* ESP_COMPILER_DESIGNATED_INIT_AGGREGATE_TYPE_EMPTY(pchr)
* ESP_COMPILER_DESIGNATED_INIT_AGGREGATE_TYPE_STR(arr, "Value")
* };
*/
#ifdef __cplusplus
#define ESP_COMPILER_DESIGNATED_INIT_AGGREGATE_TYPE_STR(member, value) { .member = value },
#define ESP_COMPILER_DESIGNATED_INIT_AGGREGATE_TYPE_EMPTY(member) .member = { },
#else
#define ESP_COMPILER_DESIGNATED_INIT_AGGREGATE_TYPE_STR(member, value) .member = value,
#define ESP_COMPILER_DESIGNATED_INIT_AGGREGATE_TYPE_EMPTY(member)
#endif
#endif