gecko-dev/mfbt/Types.h

202 lines
7.0 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=8 sw=4 et tw=99 ft=cpp:
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Code.
*
* The Initial Developer of the Original Code is
* The Mozilla Foundation
* Portions created by the Initial Developer are Copyright (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/*
* NB: This header must be both valid C and C++. It must be
* include-able by code embedding SpiderMonkey *and* Gecko.
*/
#ifndef mozilla_Types_h_
#define mozilla_Types_h_
/*
* mfbt is logically "lower level" than js/src, but needs basic
* definitions of numerical types and macros for compiler/linker
* directives. js/src already goes through some pain to provide them
* on numerous platforms, so instead of moving all that goop here,
* this header makes use of the fact that for the foreseeable future
* mfbt code will be part and parcel with libmozjs, static or not.
*
* For now, the policy is to use jstypes definitions but add a layer
* of indirection on top of them in case a Great Refactoring ever
* happens.
*/
#include "jstypes.h"
/*
* The numerical types provided by jstypes.h that are allowed within
* mfbt code are
*
* stddef types: size_t, ptrdiff_t, etc.
* stdin [sic] types: int8, uint32, etc.
*
* stdint types (int8_t etc.), are available for use here, but doing
* so would change SpiderMonkey's and Gecko's contracts with
* embedders: stdint types have not yet appeared in public APIs.
*/
#define MOZ_EXPORT_API(type_) JS_EXPORT_API(type_)
#define MOZ_IMPORT_API(type_) JS_IMPORT_API(type_)
/*
* mfbt definitions need to see export declarations when built, but
* other code needs to see import declarations when using mfbt.
*/
#if defined(IMPL_MFBT)
# define MFBT_API(type_) MOZ_EXPORT_API(type_)
#else
# define MFBT_API(type_) MOZ_IMPORT_API(type_)
#endif
#define MOZ_BEGIN_EXTERN_C JS_BEGIN_EXTERN_C
#define MOZ_END_EXTERN_C JS_END_EXTERN_C
#ifdef __cplusplus
/*
* g++ requires -std=c++0x or -std=gnu++0x to support C++11 functionality
* without warnings (functionality used by the macros below). These modes are
* detectable by checking whether __GXX_EXPERIMENTAL_CXX0X__ is defined or, more
* standardly, by checking whether __cplusplus has a C++11 or greater value.
* Current versions of g++ do not correctly set __cplusplus, so we check both
* for forward compatibility.
*/
#if defined(__clang__)
# if __clang_major__ >= 3
# define MOZ_HAVE_CXX11_DELETE
# define MOZ_HAVE_CXX11_OVERRIDE
# elif __clang_major__ == 2
# if __clang_minor__ >= 9
# define MOZ_HAVE_CXX11_DELETE
# endif
# endif
#elif defined(__GNUC__)
# if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
# if __GNUC__ > 4
# define MOZ_HAVE_CXX11_DELETE
# define MOZ_HAVE_CXX11_OVERRIDE
# elif __GNUC__ == 4
# if __GNUC_MINOR__ >= 7
# define MOZ_HAVE_CXX11_OVERRIDE
# endif
# if __GNUC_MINOR__ >= 4
# define MOZ_HAVE_CXX11_DELETE
# endif
# endif
# endif
#elif defined(_MSC_VER)
# if _MSC_VER >= 1400
# define MOZ_HAVE_CXX11_OVERRIDE
# endif
#endif
/*
* MOZ_DELETE, specified immediately prior to the ';' terminating an undefined-
* method declaration, attempts to delete that method from the corresponding
* class. An attempt to use the method will always produce an error *at compile
* time* (instead of sometimes as late as link time) when this macro can be
* implemented. For example, you can use MOZ_DELETE to produce classes with no
* implicit copy constructor or assignment operator:
*
* struct NonCopyable
* {
* private:
* NonCopyable(const NonCopyable& other) MOZ_DELETE;
* void operator=(const NonCopyable& other) MOZ_DELETE;
* };
*
* If MOZ_DELETE can't be implemented for the current compiler, use of the
* annotated method will still cause an error, but the error might occur at link
* time in some cases rather than at compile time.
*
* MOZ_DELETE relies on C++11 functionality not universally implemented. As a
* backstop, method declarations using MOZ_DELETE should be private.
*/
#if defined(MOZ_HAVE_CXX11_DELETE)
# define MOZ_DELETE = delete
#else
# define MOZ_DELETE /* no support */
#endif
/*
* MOZ_OVERRIDE explicitly indicates that a virtual member function in a class
* overrides a member function of a base class, rather than potentially being a
* new member function. MOZ_OVERRIDE should be placed immediately before the
* ';' terminating the member function's declaration, or before '= 0;' if the
* member function is pure. If the member function is defined in the class
* definition, it should appear before the opening brace of the function body.
*
* class Base
* {
* public:
* virtual void f() = 0;
* };
* class Derived1 : public Base
* {
* public:
* virtual void f() MOZ_OVERRIDE;
* };
* class Derived2 : public Base
* {
* public:
* virtual void f() MOZ_OVERRIDE = 0;
* };
* class Derived3 : public Base
* {
* public:
* virtual void f() MOZ_OVERRIDE { }
* };
*
* In compilers supporting C++11 override controls, MOZ_OVERRIDE *requires* that
* the function marked with it override a member function of a base class: it
* is a compile error if it does not. Otherwise MOZ_OVERRIDE does not affect
* semantics and merely documents the override relationship to the reader (but
* of course must still be used correctly to not break C++11 compilers).
*/
#if defined(MOZ_HAVE_CXX11_OVERRIDE)
# define MOZ_OVERRIDE override
#else
# define MOZ_OVERRIDE /* no support */
#endif
#endif /* __cplusplus */
#endif /* mozilla_Types_h_ */