зеркало из https://github.com/mozilla/pjs.git
358 строки
13 KiB
C++
358 строки
13 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):
|
|
* Jeff Walden <jwalden+code@mit.edu> (original author)
|
|
*
|
|
* 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 ***** */
|
|
|
|
/* Implementations of various class and method modifier attributes. */
|
|
|
|
#ifndef mozilla_Attributes_h_
|
|
#define mozilla_Attributes_h_
|
|
|
|
/*
|
|
* This header does not include any other headers so that it can be included by
|
|
* code that is (only currently) mfbt-incompatible.
|
|
*/
|
|
|
|
/*
|
|
* MOZ_INLINE is a macro which expands to tell the compiler that the method
|
|
* decorated with it should be inlined. This macro is usable from C and C++
|
|
* code, even though C89 does not support the |inline| keyword. The compiler
|
|
* may ignore this directive if it chooses.
|
|
*/
|
|
#if defined(__cplusplus)
|
|
# define MOZ_INLINE inline
|
|
#elif defined(_MSC_VER)
|
|
# define MOZ_INLINE __inline
|
|
#elif defined(__GNUC__)
|
|
# define MOZ_INLINE __inline__
|
|
#else
|
|
# define MOZ_INLINE inline
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_ALWAYS_INLINE is a macro which expands to tell the compiler that the
|
|
* method decorated with it must be inlined, even if the compiler thinks
|
|
* otherwise. This is only a (much) stronger version of the MOZ_INLINE hint:
|
|
* compilers are not guaranteed to respect it (although they're much more likely
|
|
* to do so).
|
|
*/
|
|
#if defined(DEBUG)
|
|
# define MOZ_ALWAYS_INLINE MOZ_INLINE
|
|
#elif defined(_MSC_VER)
|
|
# define MOZ_ALWAYS_INLINE __forceinline
|
|
#elif defined(__GNUC__)
|
|
# define MOZ_ALWAYS_INLINE __attribute__((always_inline)) MOZ_INLINE
|
|
#else
|
|
# define MOZ_ALWAYS_INLINE MOZ_INLINE
|
|
#endif
|
|
|
|
/*
|
|
* 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__)
|
|
/*
|
|
* Per Clang documentation, "Note that marketing version numbers should not
|
|
* be used to check for language features, as different vendors use different
|
|
* numbering schemes. Instead, use the feature checking macros."
|
|
*/
|
|
# ifndef __has_extension
|
|
# define __has_extension __has_feature /* compatibility, for older versions of clang */
|
|
# endif
|
|
# if __has_extension(cxx_deleted_functions)
|
|
# define MOZ_HAVE_CXX11_DELETE
|
|
# endif
|
|
# if __has_extension(cxx_override_control)
|
|
# define MOZ_HAVE_CXX11_OVERRIDE
|
|
# define MOZ_HAVE_CXX11_FINAL final
|
|
# endif
|
|
# if __has_attribute(noinline)
|
|
# define MOZ_HAVE_NEVER_INLINE __attribute__((noinline))
|
|
# endif
|
|
# if __has_attribute(noreturn)
|
|
# define MOZ_HAVE_NORETURN __attribute__((noreturn))
|
|
# endif
|
|
#elif defined(__GNUC__)
|
|
# if defined(__GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
|
|
# if __GNUC__ > 4
|
|
# define MOZ_HAVE_CXX11_DELETE
|
|
# define MOZ_HAVE_CXX11_OVERRIDE
|
|
# define MOZ_HAVE_CXX11_FINAL final
|
|
# elif __GNUC__ == 4
|
|
# if __GNUC_MINOR__ >= 7
|
|
# define MOZ_HAVE_CXX11_OVERRIDE
|
|
# define MOZ_HAVE_CXX11_FINAL final
|
|
# endif
|
|
# if __GNUC_MINOR__ >= 4
|
|
# define MOZ_HAVE_CXX11_DELETE
|
|
# endif
|
|
# endif
|
|
# else
|
|
/* __final is a non-C++11 GCC synonym for 'final', per GCC r176655. */
|
|
# if __GNUC__ > 4
|
|
# define MOZ_HAVE_CXX11_FINAL __final
|
|
# elif __GNUC__ == 4
|
|
# if __GNUC_MINOR__ >= 7
|
|
# define MOZ_HAVE_CXX11_FINAL __final
|
|
# endif
|
|
# endif
|
|
# endif
|
|
# define MOZ_HAVE_NEVER_INLINE __attribute__((noinline))
|
|
# define MOZ_HAVE_NORETURN __attribute__((noreturn))
|
|
#elif defined(_MSC_VER)
|
|
# if _MSC_VER >= 1400
|
|
# define MOZ_HAVE_CXX11_OVERRIDE
|
|
/* MSVC currently spells "final" as "sealed". */
|
|
# define MOZ_HAVE_CXX11_FINAL sealed
|
|
# endif
|
|
# define MOZ_HAVE_NEVER_INLINE __declspec(noinline)
|
|
# define MOZ_HAVE_NORETURN __declspec(noreturn)
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_NEVER_INLINE is a macro which expands to tell the compiler that the
|
|
* method decorated with it must never be inlined, even if the compiler would
|
|
* otherwise choose to inline the method. Compilers aren't absolutely
|
|
* guaranteed to support this, but most do.
|
|
*/
|
|
#if defined(MOZ_HAVE_NEVER_INLINE)
|
|
# define MOZ_NEVER_INLINE MOZ_HAVE_NEVER_INLINE
|
|
#else
|
|
# define MOZ_NEVER_INLINE /* no support */
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_NORETURN, specified at the start of a function declaration, indicates
|
|
* that the given function does not return. (The function definition does not
|
|
* need to be annotated.)
|
|
*
|
|
* MOZ_NORETURN void abort(const char* msg);
|
|
*
|
|
* This modifier permits the compiler to optimize code assuming a call to such a
|
|
* function will never return. It also enables the compiler to avoid spurious
|
|
* warnings about not initializing variables, or about any other seemingly-dodgy
|
|
* operations performed after the function returns.
|
|
*
|
|
* This modifier does not affect the corresponding function's linking behavior.
|
|
*/
|
|
#if defined(MOZ_HAVE_NORETURN)
|
|
# define MOZ_NORETURN MOZ_HAVE_NORETURN
|
|
#else
|
|
# define MOZ_NORETURN /* no support */
|
|
#endif
|
|
|
|
/*
|
|
* MOZ_ASAN_BLACKLIST is a macro to tell AddressSanitizer (a compile-time
|
|
* instrumentation shipped with Clang) to not instrument the annotated function.
|
|
* Furthermore, it will prevent the compiler from inlining the function because
|
|
* inlining currently breaks the blacklisting mechanism of AddressSanitizer.
|
|
*/
|
|
#if defined(MOZ_ASAN)
|
|
# define MOZ_ASAN_BLACKLIST MOZ_NEVER_INLINE __attribute__((no_address_safety_analysis))
|
|
# else
|
|
# define MOZ_ASAN_BLACKLIST
|
|
#endif
|
|
|
|
|
|
#ifdef __cplusplus
|
|
|
|
/*
|
|
* 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
|
|
|
|
/*
|
|
* MOZ_FINAL indicates that some functionality cannot be overridden through
|
|
* inheritance. It can be used to annotate either classes/structs or virtual
|
|
* member functions.
|
|
*
|
|
* To annotate a class/struct with MOZ_FINAL, place MOZ_FINAL immediately after
|
|
* the name of the class, before the list of classes from which it derives (if
|
|
* any) and before its opening brace. MOZ_FINAL must not be used to annotate
|
|
* unnamed classes or structs. (With some compilers, and with C++11 proper, the
|
|
* underlying expansion is ambiguous with specifying a class name.)
|
|
*
|
|
* class Base MOZ_FINAL
|
|
* {
|
|
* public:
|
|
* Base();
|
|
* ~Base();
|
|
* virtual void f() { }
|
|
* };
|
|
* // This will be an error in some compilers:
|
|
* class Derived : public Base
|
|
* {
|
|
* public:
|
|
* ~Derived() { }
|
|
* };
|
|
*
|
|
* One particularly common reason to specify MOZ_FINAL upon a class is to tell
|
|
* the compiler that it's not dangerous for it to have a non-virtual destructor
|
|
* yet have one or more virtual functions, silencing the warning it might emit
|
|
* in this case. Suppose Base above weren't annotated with MOZ_FINAL. Because
|
|
* ~Base() is non-virtual, an attempt to delete a Derived* through a Base*
|
|
* wouldn't call ~Derived(), so any cleanup ~Derived() might do wouldn't happen.
|
|
* (Formally C++ says behavior is undefined, but compilers will likely just call
|
|
* ~Base() and not ~Derived().) Specifying MOZ_FINAL tells the compiler that
|
|
* it's safe for the destructor to be non-virtual.
|
|
*
|
|
* In compilers implementing final controls, it is an error to inherit from a
|
|
* class annotated with MOZ_FINAL. In other compilers it serves only as
|
|
* documentation.
|
|
*
|
|
* To annotate a virtual member function with MOZ_FINAL, place MOZ_FINAL
|
|
* 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. (This placement is identical to that for MOZ_OVERRIDE.
|
|
* If both are used, they should appear in the order 'MOZ_FINAL MOZ_OVERRIDE'
|
|
* for consistency.)
|
|
*
|
|
* class Base
|
|
* {
|
|
* public:
|
|
* virtual void f() MOZ_FINAL;
|
|
* };
|
|
* class Derived
|
|
* {
|
|
* public:
|
|
* // This will be an error in some compilers:
|
|
* virtual void f();
|
|
* };
|
|
*
|
|
* In compilers implementing final controls, it is an error for a derived class
|
|
* to override a method annotated with MOZ_FINAL. In other compilers it serves
|
|
* only as documentation.
|
|
*/
|
|
#if defined(MOZ_HAVE_CXX11_FINAL)
|
|
# define MOZ_FINAL MOZ_HAVE_CXX11_FINAL
|
|
#else
|
|
# define MOZ_FINAL /* no support */
|
|
#endif
|
|
|
|
/**
|
|
* MOZ_WARN_UNUSED_RESULT tells the compiler to emit a warning if a function's
|
|
* return value is not used by the caller.
|
|
*
|
|
* Place this attribute at the very beginning of a function definition. For
|
|
* example, write
|
|
*
|
|
* MOZ_WARN_UNUSED_RESULT int foo();
|
|
*
|
|
* or
|
|
*
|
|
* MOZ_WARN_UNUSED_RESULT int foo() { return 42; }
|
|
*/
|
|
#if defined(__GNUC__) || defined(__clang__)
|
|
# define MOZ_WARN_UNUSED_RESULT __attribute__ ((warn_unused_result))
|
|
#else
|
|
# define MOZ_WARN_UNUSED_RESULT
|
|
#endif
|
|
|
|
#endif /* __cplusplus */
|
|
|
|
#endif /* mozilla_Attributes_h_ */
|