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/*
* Copyright 2012 10gen 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.
*/
#pragma once
/**
* Include "mongo/platform/compiler.h" to get compiler-targeted macro definitions and utilities.
*
* The following macros are provided in all compiler environments:
*
*
* MONGO_COMPILER_NORETURN
*
* Instructs the compiler that the decorated function will not return through the normal return
* path.
*
* Correct: MONGO_COMPILER_NORETURN void myAbortFunction();
*
*
* MONGO_COMPILER_VARIABLE_UNUSED
*
* Instructs the compiler not to warn if it detects no use of the decorated variable.
* Typically only useful for variables that are always declared but only used in
* conditionally-compiled code.
*
* Correct: MONGO_COMPILER_VARIABLE_UNUSED int ignored;
*
*
* MONGO_COMPILER_ALIGN_TYPE(ALIGNMENT)
*
* Instructs the compiler to use the given minimum alignment for the decorated type.
*
* Alignments should probably always be powers of two. Also, note that most allocators will not
* be able to guarantee better than 16- or 32-byte alignment.
*
* Correct:
* class MONGO_COMPILER_ALIGN_TYPE(16) MyClass {...};
*
* Incorrect:
* MONGO_COMPILER_ALIGN_TYPE(16) class MyClass {...};
* class MyClass{...} MONGO_COMPILER_ALIGN_TYPE(16);
*
*
* MONGO_COMPILER_ALIGN_VARIABLE(ALIGNMENT)
*
* Instructs the compiler to use the given minimum alignment for the decorated variable.
*
* Note that most allocators will not allow heap allocated alignments that are better than 16- or
* 32-byte aligned. Stack allocators may only guarantee up to the natural word length worth of
* alignment.
*
* Correct:
* class MyClass {
* MONGO_COMPILER_ALIGN_VARIABLE(8) char a;
* };
*
* MONGO_COMPILER_ALIGN_VARIABLE(8) class MyClass {...} singletonInstance;
*
* Incorrect:
* int MONGO_COMPILER_ALIGN_VARIABLE(16) a, b;
*
*
* MONGO_COMPILER_API_EXPORT
*
* Instructs the compiler to label the given type, variable or function as part of the
* exported interface of the library object under construction.
*
* Correct:
* MONGO_COMPILER_API_EXPORT int globalSwitch;
* class MONGO_COMPILER_API_EXPORT ExportedType { ... };
* MONGO_COMPILER_API_EXPORT SomeType exportedFunction(...);
*
* NOTE: Rather than using this macro directly, one typically declares another macro named for the
* library, which is conditionally defined to either MONGO_COMIPLER_API_EXPORT or
* MONGO_COMPILER_API_IMPORT based on whether the compiler is currently building the library or
* building an object that depends on the library, respectively. For example, MONGO_CLIENT_API
* might be defined to MONGO_COMPILER_API_EXPORT when building the MongoDB shared library, and to
* MONGO_COMPILER_API_IMPORT when building an application that links against the shared library.
*
*
* MONGO_COMPILER_API_IMPORT
*
* Instructs the compiler to label the given type, variable or function as imported
* from another library, and not part of the library object under construction.
*
* Same correct/incorrect usage as for MONGO_COMPILER_API_EXPORT.
*
*
* MONGO_COMPILER_API_CALLING_CONVENTION
*
* Explicitly decorates a function declaration the api calling convention used for
* shared libraries.
*
* Same correct/incorrect usage as for MONGO_COMPILER_API_EXPORT.
*/
#if defined(_MSC_VER)
#include "mongo/platform/compiler_msvc.h"
#elif defined(__GNUC__)
#include "mongo/platform/compiler_gcc.h"
#else
#error "Unsupported compiler family"
#endif
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