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gecko-dev/xpcom/base/nscore.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** 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.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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 ***** */
#ifndef nscore_h___
#define nscore_h___
/**
* Make sure that we have the proper platform specific
* c++ definitions needed by nscore.h
*/
#ifndef _XPCOM_CONFIG_H_
#include "xpcom-config.h"
#endif
/**
* Incorporate the core NSPR data types which XPCOM uses.
*/
#include "prtypes.h"
/* Core XPCOM declarations. */
/**
* Macros defining the target platform...
*/
#ifdef _WIN32
#define NS_WIN32 1
#elif defined(__unix)
#define NS_UNIX 1
#elif defined(XP_OS2)
#define NS_OS2 1
#endif
/*----------------------------------------------------------------------*/
/* Import/export defines */
/**
* Using the visibility("hidden") attribute allows the compiler to use
* PC-relative addressing to call this function. If a function does not
* access any global data, and does not call any methods which are not either
* file-local or hidden, then on ELF systems we avoid loading the address of
* the PLT into a register at the start of the function, which reduces code
* size and frees up a register for general use.
*
* As a general rule, this should be used for any non-exported symbol
* (including virtual method implementations). NS_IMETHOD uses this by
* default; if you need to have your NS_IMETHOD functions exported, you can
* wrap your class as follows:
*
* #undef IMETHOD_VISIBILITY
* #define IMETHOD_VISIBILITY NS_VISIBILITY_DEFAULT
*
* class Foo {
* ...
* };
*
* #undef IMETHOD_VISIBILITY
* #define IMETHOD_VISIBILITY NS_VISIBILITY_HIDDEN
*
* Don't forget to change the visibility back to hidden before the end
* of a header!
*
* Other examples:
*
* NS_HIDDEN_(int) someMethod();
* SomeCtor() NS_HIDDEN;
*/
#ifdef HAVE_VISIBILITY_HIDDEN_ATTRIBUTE
#define NS_VISIBILITY_HIDDEN __attribute__ ((visibility ("hidden")))
#else
#define NS_VISIBILITY_HIDDEN
#endif
#if defined(HAVE_VISIBILITY_ATTRIBUTE)
#define NS_VISIBILITY_DEFAULT __attribute__ ((visibility ("default")))
#else
#define NS_VISIBILITY_DEFAULT
#endif
#define NS_HIDDEN_(type) NS_VISIBILITY_HIDDEN type
#define NS_EXTERNAL_VIS_(type) NS_VISIBILITY_DEFAULT type
#define NS_HIDDEN NS_VISIBILITY_HIDDEN
#define NS_EXTERNAL_VIS NS_VISIBILITY_DEFAULT
#undef IMETHOD_VISIBILITY
#define IMETHOD_VISIBILITY NS_VISIBILITY_HIDDEN
/**
* Mark a function as using a potentially non-standard function calling
* convention. This can be used on functions that are called very
* frequently, to reduce the overhead of the function call. It is still worth
* using the macro for C++ functions which take no parameters since it allows
* passing |this| in a register.
*
* - Do not use this on any scriptable interface method since xptcall won't be
* aware of the different calling convention.
* - This must appear on the declaration, not the definition.
* - Adding this to a public function _will_ break binary compatibility.
* - This may be used on virtual functions but you must ensure it is applied
* to all implementations - the compiler will _not_ warn but it will crash.
* - This has no effect for inline functions or functions which take a
* variable number of arguments.
* - __fastcall on windows should not be applied to class
* constructors/destructors - use the NS_CONSTRUCTOR_FASTCALL macro for
* constructors/destructors.
*
* Examples: int NS_FASTCALL func1(char *foo);
* NS_HIDDEN_(int) NS_FASTCALL func2(char *foo);
*/
#if defined(__i386__) && defined(__GNUC__) && (__GNUC__ >= 3) && !defined(XP_OS2)
#define NS_FASTCALL __attribute__ ((regparm (3), stdcall))
#define NS_CONSTRUCTOR_FASTCALL __attribute__ ((regparm (3), stdcall))
#elif defined(XP_WIN)
#define NS_FASTCALL __fastcall
#define NS_CONSTRUCTOR_FASTCALL
#else
#define NS_FASTCALL
#define NS_CONSTRUCTOR_FASTCALL
#endif
/*
* NS_DEFCALL undoes the effect of a global regparm/stdcall setting
* so that xptcall works correctly.
*/
#if defined(__i386__) && defined(__GNUC__) && (__GNUC__ >= 3) && !defined(XP_OS2)
#define NS_DEFCALL __attribute__ ((regparm (0), cdecl))
#else
#define NS_DEFCALL
#endif
#ifdef NS_WIN32
#define NS_IMPORT __declspec(dllimport)
#define NS_IMPORT_(type) __declspec(dllimport) type __stdcall
#define NS_EXPORT __declspec(dllexport)
#define NS_EXPORT_(type) __declspec(dllexport) type __stdcall
#define NS_IMETHOD_(type) virtual type __stdcall
#define NS_IMETHODIMP_(type) type __stdcall
#define NS_METHOD_(type) type __stdcall
#define NS_CALLBACK_(_type, _name) _type (__stdcall * _name)
#define NS_STDCALL __stdcall
#define NS_FROZENCALL __cdecl
/*
These are needed to mark static members in exported classes, due to
gcc bug XXX insert bug# here.
*/
#define NS_EXPORT_STATIC_MEMBER_(type) type
#define NS_IMPORT_STATIC_MEMBER_(type) type
#elif defined(XP_OS2) && defined(__declspec)
#define NS_IMPORT __declspec(dllimport)
#define NS_IMPORT_(type) type __declspec(dllimport)
#define NS_EXPORT __declspec(dllexport)
#define NS_EXPORT_(type) type __declspec(dllexport)
#define NS_IMETHOD_(type) virtual type
#define NS_IMETHODIMP_(type) type
#define NS_METHOD_(type) type
#define NS_CALLBACK_(_type, _name) _type (* _name)
#define NS_STDCALL
#define NS_FROZENCALL
#define NS_EXPORT_STATIC_MEMBER_(type) NS_EXTERNAL_VIS_(type)
#define NS_IMPORT_STATIC_MEMBER_(type) NS_EXTERNAL_VIS_(type)
#else
#define NS_IMPORT NS_EXTERNAL_VIS
#define NS_IMPORT_(type) NS_EXTERNAL_VIS_(type)
#define NS_EXPORT NS_EXTERNAL_VIS
#define NS_EXPORT_(type) NS_EXTERNAL_VIS_(type)
#define NS_IMETHOD_(type) virtual IMETHOD_VISIBILITY type NS_DEFCALL
#define NS_IMETHODIMP_(type) type
#define NS_METHOD_(type) type
#define NS_CALLBACK_(_type, _name) _type (* _name)
#define NS_STDCALL
#define NS_FROZENCALL
#define NS_EXPORT_STATIC_MEMBER_(type) NS_EXTERNAL_VIS_(type)
#define NS_IMPORT_STATIC_MEMBER_(type) NS_EXTERNAL_VIS_(type)
#endif
/**
* Macro for creating typedefs for pointer-to-member types which are
* declared with stdcall. It is important to use this for any type which is
* declared as stdcall (i.e. NS_IMETHOD). For example, instead of writing:
*
* typedef nsresult (nsIFoo::*someType)(nsISupports* arg);
*
* you should write:
*
* typedef
* NS_STDCALL_FUNCPROTO(nsresult, someType, nsIFoo, typeFunc, (nsISupports*));
*
* where nsIFoo::typeFunc is any method declared as
* NS_IMETHOD typeFunc(nsISupports*);
*
* XXX this can be simplified to always use the non-typeof implementation
* when http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11893 is fixed.
*/
#ifdef __GNUC__
#define NS_STDCALL_FUNCPROTO(ret, name, class, func, args) \
typeof(&class::func) name
#else
#define NS_STDCALL_FUNCPROTO(ret, name, class, func, args) \
ret (NS_STDCALL class::*name) args
#endif
/**
* Generic API modifiers which return the standard XPCOM nsresult type
*/
#define NS_IMETHOD NS_IMETHOD_(nsresult)
#define NS_IMETHODIMP NS_IMETHODIMP_(nsresult)
#define NS_METHOD NS_METHOD_(nsresult)
#define NS_CALLBACK(_name) NS_CALLBACK_(nsresult, _name)
/**
* Import/Export macros for XPCOM APIs
*/
#ifdef __cplusplus
#define NS_EXTERN_C extern "C"
#else
#define NS_EXTERN_C
#endif
#define EXPORT_XPCOM_API(type) NS_EXTERN_C NS_EXPORT type NS_FROZENCALL
#define IMPORT_XPCOM_API(type) NS_EXTERN_C NS_IMPORT type NS_FROZENCALL
#define GLUE_XPCOM_API(type) NS_EXTERN_C NS_HIDDEN_(type) NS_FROZENCALL
#ifdef _IMPL_NS_COM
#define XPCOM_API(type) EXPORT_XPCOM_API(type)
#elif defined(XPCOM_GLUE)
#define XPCOM_API(type) GLUE_XPCOM_API(type)
#else
#define XPCOM_API(type) IMPORT_XPCOM_API(type)
#endif
#ifdef MOZ_ENABLE_LIBXUL
#define NS_COM
#elif defined(_IMPL_NS_COM)
#define NS_COM NS_EXPORT
#elif defined(XPCOM_GLUE)
#define NS_COM
#else
#define NS_COM NS_IMPORT
#endif
#ifdef MOZILLA_INTERNAL_API
# define NS_COM_GLUE NS_COM
/*
The frozen string API has different definitions of nsAC?String
classes than the internal API. On systems that explicitly declare
dllexport symbols this is not a problem, but on ELF systems
internal symbols can accidentally "shine through"; we rename the
internal classes to avoid symbol conflicts.
*/
# define nsAString nsAString_internal
# define nsACString nsACString_internal
#else
# ifdef HAVE_VISIBILITY_ATTRIBUTE
# define NS_COM_GLUE NS_VISIBILITY_HIDDEN
# else
# define NS_COM_GLUE
# endif
#endif
/**
* NS_NO_VTABLE is emitted by xpidl in interface declarations whenever
* xpidl can determine that the interface can't contain a constructor.
* This results in some space savings and possible runtime savings -
* see bug 49416. We undefine it first, as xpidl-generated headers
* define it for IDL uses that don't include this file.
*/
#ifdef NS_NO_VTABLE
#undef NS_NO_VTABLE
#endif
#if defined(_MSC_VER) && _MSC_VER >= 1100
#define NS_NO_VTABLE __declspec(novtable)
#else
#define NS_NO_VTABLE
#endif
/**
* Generic XPCOM result data type
*/
typedef PRUint32 nsresult;
/**
* Reference count values
*
* This is the return type for AddRef() and Release() in nsISupports.
* IUnknown of COM returns an unsigned long from equivalent functions.
* The following ifdef exists to maintain binary compatibility with
* IUnknown.
*/
#if defined(XP_WIN) && PR_BYTES_PER_LONG == 4
typedef unsigned long nsrefcnt;
#else
typedef PRUint32 nsrefcnt;
#endif
/**
* The preferred symbol for null.
*/
#define nsnull 0
#include "nsError.h"
/* ------------------------------------------------------------------------ */
/* Casting macros for hiding C++ features from older compilers */
/*
All our compiler support template specialization, but not all support the
|template <>| notation. The compiler that don't understand this notation
just omit it for specialization.
Need to add an autoconf test for this.
*/
/* under Metrowerks (Mac), we don't have autoconf yet */
#ifdef __MWERKS__
#define HAVE_CPP_PARTIAL_SPECIALIZATION
#define HAVE_CPP_MODERN_SPECIALIZE_TEMPLATE_SYNTAX
#define HAVE_CPP_ACCESS_CHANGING_USING
#define HAVE_CPP_AMBIGUITY_RESOLVING_USING
#define HAVE_CPP_EXPLICIT
#define HAVE_CPP_TYPENAME
#define HAVE_CPP_BOOL
#define HAVE_CPP_NAMESPACE_STD
#define HAVE_CPP_UNAMBIGUOUS_STD_NOTEQUAL
#define HAVE_CPP_2BYTE_WCHAR_T
#endif
/* under VC++ (Windows), we don't have autoconf yet */
#if defined(_MSC_VER) && (_MSC_VER>=1100)
/* VC++ 5.0 and greater implement template specialization, 4.2 is unknown */
#define HAVE_CPP_MODERN_SPECIALIZE_TEMPLATE_SYNTAX
#define HAVE_CPP_EXPLICIT
#define HAVE_CPP_TYPENAME
#define HAVE_CPP_ACCESS_CHANGING_USING
#if (_MSC_VER==1100)
/* VC++5.0 has an internal compiler error (sometimes) without this */
#undef HAVE_CPP_ACCESS_CHANGING_USING
#endif
#define HAVE_CPP_NAMESPACE_STD
#define HAVE_CPP_UNAMBIGUOUS_STD_NOTEQUAL
#define HAVE_CPP_2BYTE_WCHAR_T
#endif
#ifndef __PRUNICHAR__
#define __PRUNICHAR__
/* For now, don't use wchar_t on Unix because it breaks the Netscape
* commercial build. When this is fixed there will be no need for the
* |NS_REINTERPRET_CAST| in nsLiteralString.h either.
*/
#if defined(HAVE_CPP_2BYTE_WCHAR_T) && defined(NS_WIN32)
typedef wchar_t PRUnichar;
#else
typedef PRUint16 PRUnichar;
#endif
#endif
/*
If the compiler doesn't support |explicit|, we'll just make it go away, trusting
that the builds under compilers that do have it will keep us on the straight and narrow.
*/
#ifndef HAVE_CPP_EXPLICIT
#define explicit
#endif
#ifndef HAVE_CPP_TYPENAME
#define typename
#endif
#ifdef HAVE_CPP_MODERN_SPECIALIZE_TEMPLATE_SYNTAX
#define NS_SPECIALIZE_TEMPLATE template <>
#else
#define NS_SPECIALIZE_TEMPLATE
#endif
/* unix and beos now determine this automatically */
#if ! defined XP_UNIX && ! defined XP_BEOS && !defined(XP_OS2)
#ifndef HAVE_CPP_NEW_CASTS
#define HAVE_CPP_NEW_CASTS 1 /* we'll be optimistic. */
#endif
#endif
#if defined(HAVE_CPP_NEW_CASTS)
#define NS_STATIC_CAST(__type, __ptr) static_cast< __type >(__ptr)
#define NS_CONST_CAST(__type, __ptr) const_cast< __type >(__ptr)
#define NS_REINTERPRET_POINTER_CAST(__type, __ptr) reinterpret_cast< __type >(__ptr)
#define NS_REINTERPRET_NONPOINTER_CAST(__type, __obj) reinterpret_cast< __type >(__obj)
#define NS_REINTERPRET_CAST(__type, __expr) reinterpret_cast< __type >(__expr)
#else
#define NS_STATIC_CAST(__type, __ptr) ((__type)(__ptr))
#define NS_CONST_CAST(__type, __ptr) ((__type)(__ptr))
#define NS_REINTERPRET_POINTER_CAST(__type, __ptr) ((__type)((void*)(__ptr)))
#define NS_REINTERPRET_NONPOINTER_CAST(__type, __obj) ((__type)(__obj))
/* Note: the following is only appropriate for pointers. */
#define NS_REINTERPRET_CAST(__type, __expr) NS_REINTERPRET_POINTER_CAST(__type, __expr)
/*
Why cast to a |void*| first? Well, when old-style casting from
a pointer to a base to a pointer to a derived class, the cast will be
ambiguous if the source pointer type appears multiple times in the
destination, e.g.,
class Base {};
class Derived : public Base, public Base {};
void foo( Base* b )
{
((Derived*)b)->some_derived_member ... // Error: Ambiguous, expand from which |Base|?
}
an old-style cast (like |static_cast|) will change the pointer, but
here, doesn't know how. The cast to |void*| prevents it from thinking
it needs to expand the original pointer.
The cost is, |NS_REINTERPRET_CAST| is no longer appropriate for non-pointer
conversions. Also, mis-applying |NS_REINTERPRET_CAST| to cast |this| to something
will still expand the pointer to the outer object in standards complying compilers.
*/
/*
No sense in making an NS_DYNAMIC_CAST() macro: you can't duplicate
the semantics. So if you want to dynamic_cast, then just use it
"straight", no macro.
*/
#endif
/*
* Use these macros to do 64bit safe pointer conversions.
*/
#define NS_PTR_TO_INT32(x) ((PRInt32) (PRWord) (x))
#define NS_PTR_TO_UINT32(x) ((PRUint32) (PRWord) (x))
#define NS_INT32_TO_PTR(x) ((void *) (PRWord) (x))
/*
* Use NS_STRINGIFY to form a string literal from the value of a macro.
*/
#define NS_STRINGIFY_HELPER(x_) #x_
#define NS_STRINGIFY(x_) NS_STRINGIFY_HELPER(x_)
/*
* These macros allow you to give a hint to the compiler about branch
* probability so that it can better optimize. Use them like this:
*
* if (NS_LIKELY(v == 1)) {
* ... expected code path ...
* }
*
* if (NS_UNLIKELY(v == 0)) {
* ... non-expected code path ...
* }
*
*/
#if defined(__GNUC__) && (__GNUC__ > 2)
#define NS_LIKELY(x) (__builtin_expect((x), 1))
#define NS_UNLIKELY(x) (__builtin_expect((x), 0))
#else
#define NS_LIKELY(x) (x)
#define NS_UNLIKELY(x) (x)
#endif
#endif /* nscore_h___ */
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