gecko-dev/xpcom/base/nscore.h
mkaply%us.ibm.com 5fc1abd8ef # 25555
r= dp@netscape.com
OS/2 changes for Mozilla - add #ifdef, change #ifdef
2000-02-29 15:50:48 +00:00

232 lines
6.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*/
#ifndef nscore_h___
#define nscore_h___
#ifdef _WIN32
#define NS_WIN32 1
#endif
#if defined(__unix)
#define NS_UNIX 1
#endif
#if defined(XP_OS2)
#define NS_OS2 1
#endif
#include "prtypes.h"
#ifdef __cplusplus
#include "nsDebug.h"
#endif
#ifndef __PRUNICHAR__
#define __PRUNICHAR__
typedef PRUint16 PRUnichar;
#endif
/* The preferred symbol for null. */
#define nsnull 0
/* Define brackets for protecting C code from C++ */
#ifdef __cplusplus
#define NS_BEGIN_EXTERN_C extern "C" {
#define NS_END_EXTERN_C }
#else
#define NS_BEGIN_EXTERN_C
#define NS_END_EXTERN_C
#endif
/*----------------------------------------------------------------------*/
/* Import/export defines */
#ifdef NS_WIN32
#define NS_IMPORT _declspec(dllimport)
#define NS_IMPORT_(type) type _declspec(dllimport) __stdcall
#define NS_EXPORT _declspec(dllexport)
/* XXX NS_EXPORT_ defined in nsCOm.h (xpcom) differs in where the __declspec
is placed. It needs to be done this way to make the 4.x compiler happy... */
#undef NS_EXPORT_
#define NS_EXPORT_(type) type _declspec(dllexport) __stdcall
#elif defined(XP_MAC)
#define NS_IMPORT
#define NS_IMPORT_(type) type
/* XXX NS_EXPORT_ defined in nsCom.h actually does an export. Here it's just sugar. */
#undef NS_EXPORT
#undef NS_EXPORT_
#define NS_EXPORT __declspec(export)
#define NS_EXPORT_(type) __declspec(export) type
#else
/* XXX do something useful? */
#define NS_IMPORT
#define NS_IMPORT_(type) type
#define NS_EXPORT
#define NS_EXPORT_(type) type
#endif
#ifdef _IMPL_NS_BASE
#define NS_BASE NS_EXPORT
#else
#define NS_BASE NS_IMPORT
#endif
#ifdef _IMPL_NS_NET
#define NS_NET NS_EXPORT
#else
#define NS_NET NS_IMPORT
#endif
#ifdef _IMPL_NS_DOM
#define NS_DOM NS_EXPORT
#else
#define NS_DOM NS_IMPORT
#endif
#ifdef _IMPL_NS_WIDGET
#define NS_WIDGET NS_EXPORT
#else
#define NS_WIDGET NS_IMPORT
#endif
#ifdef _IMPL_NS_VIEW
#define NS_VIEW NS_EXPORT
#else
#define NS_VIEW NS_IMPORT
#endif
#ifdef _IMPL_NS_GFXNONXP
#define NS_GFXNONXP NS_EXPORT
#define NS_GFXNONXP_(type) NS_EXPORT_(type)
#else
#define NS_GFXNONXP NS_IMPORT
#define NS_GFXNONXP_(type) NS_IMPORT_(type)
#endif
#ifdef _IMPL_NS_GFX
#define NS_GFX NS_EXPORT
#define NS_GFX_(type) NS_EXPORT_(type)
#else
#define NS_GFX NS_IMPORT
#define NS_GFX_(type) NS_IMPORT_(type)
#endif
#ifdef _IMPL_NS_PLUGIN
#define NS_PLUGIN NS_EXPORT
#else
#define NS_PLUGIN NS_IMPORT
#endif
#ifdef _IMPL_NS_APPSHELL
#define NS_APPSHELL NS_EXPORT
#else
#define NS_APPSHELL NS_IMPORT
#endif
/* ------------------------------------------------------------------------ */
/* 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_SPECIALIZATION
#define HAVE_CPP_MODERN_SPECIALIZE_TEMPLATE_SYNTAX
#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_SPECIALIZATION
#define HAVE_CPP_MODERN_SPECIALIZE_TEMPLATE_SYNTAX
#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)
#define HAVE_CPP_NEW_CASTS /* we'll be optimistic. */
#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_deried_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.
*/
#endif
/* 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 /* nscore_h___ */