gecko/xpcom/base/nscore.h
Jeff Muizelaar cc8b97c5a6 Bug 771317. Fix comment about FASTCALL and inline functions. r=espindola
Calling convention does not make a difference on functions that are inlined,
but that feels obvious because no call is being made. Inline functions are not
necessarily inlined so this comment is somewhat misleading.

--HG--
extra : rebase_source : f634f18d1a6669147f53162a7bc0ab08b145cc43
2012-07-05 17:38:30 -04:00

470 lines
14 KiB
C

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#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
/* Definitions of functions and operators that allocate memory. */
#if !defined(XPCOM_GLUE) && !defined(NS_NO_XPCOM) && !defined(MOZ_NO_MOZALLOC)
# include "mozilla/mozalloc.h"
# include "mozilla/mozalloc_macro_wrappers.h"
#endif
/**
* Incorporate the core NSPR data types which XPCOM uses.
*/
#include "prtypes.h"
#include "mozilla/StandardInteger.h"
/*
* This is for functions that are like malloc_usable_size. Such functions are
* used for measuring the size of data structures.
*/
typedef size_t(*nsMallocSizeOfFun)(const void *p);
/* Core XPCOM declarations. */
/*----------------------------------------------------------------------*/
/* 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")))
#elif defined(__SUNPRO_C) || defined(__SUNPRO_CC)
#define NS_VISIBILITY_DEFAULT __global
#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 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) && !defined(_WIN64)
#define NS_FASTCALL __fastcall
#define NS_CONSTRUCTOR_FASTCALL
#else
#define NS_FASTCALL
#define NS_CONSTRUCTOR_FASTCALL
#endif
#ifdef XP_WIN
#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)
#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
#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
/**
* Deprecated declarations.
*/
#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
# define MOZ_DEPRECATED __attribute__((deprecated))
#elif defined(_MSC_VER)
# define MOZ_DEPRECATED __declspec(deprecated)
#else
# define MOZ_DEPRECATED
#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 MOZILLA_INTERNAL_API
# define NS_COM_GLUE
/*
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
#if (defined(DEBUG) || defined(FORCE_BUILD_REFCNT_LOGGING))
/* Make refcnt logging part of the build. This doesn't mean that
* actual logging will occur (that requires a separate enable; see
* nsTraceRefcnt.h for more information). */
#define NS_BUILD_REFCNT_LOGGING
#endif
/* If NO_BUILD_REFCNT_LOGGING is defined then disable refcnt logging
* in the build. This overrides FORCE_BUILD_REFCNT_LOGGING. */
#if defined(NO_BUILD_REFCNT_LOGGING)
#undef NS_BUILD_REFCNT_LOGGING
#endif
/* If a program allocates memory for the lifetime of the app, it doesn't make
* sense to touch memory pages and free that memory at shutdown,
* unless we are running leak stats.
*/
#if defined(NS_TRACE_MALLOC) || defined(NS_BUILD_REFCNT_LOGGING) || defined(MOZ_VALGRIND)
#define NS_FREE_PERMANENT_DATA
#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)
#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. Make sure this is the same size as
* void* on the target. See bug 547964.
*/
#if defined(_WIN64)
# define nsnull 0LL
#else
# define nsnull 0L
#endif
#include "nsError.h"
/* ------------------------------------------------------------------------ */
/* Casting macros for hiding C++ features from older compilers */
/* under VC++ (Windows), we don't have autoconf yet */
#if defined(_MSC_VER)
#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
* |reinterpret_cast| in nsLiteralString.h either.
*/
#if defined(HAVE_CPP_2BYTE_WCHAR_T) && defined(XP_WIN)
typedef wchar_t PRUnichar;
#else
typedef PRUint16 PRUnichar;
#endif
#endif
/*
* Use these macros to do 64bit safe pointer conversions.
*/
#define NS_PTR_TO_INT32(x) ((PRInt32) (intptr_t) (x))
#define NS_PTR_TO_UINT32(x) ((PRUint32) (intptr_t) (x))
#define NS_INT32_TO_PTR(x) ((void *) (intptr_t) (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 ...
* }
*
* These macros are guaranteed to always return 0 or 1.
* The NS_FAILED/NS_SUCCEEDED macros depends on this.
* @return 0 or 1
*/
#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
/*
* If we're being linked as standalone glue, we don't want a dynamic
* dependency on NSPR libs, so we skip the debug thread-safety
* checks, and we cannot use the THREADSAFE_ISUPPORTS macros.
*/
#if defined(XPCOM_GLUE) && !defined(XPCOM_GLUE_USE_NSPR)
#define XPCOM_GLUE_AVOID_NSPR
#endif
#if defined(HAVE_THREAD_TLS_KEYWORD)
#define NS_TLS __thread
#endif
/**
* Static type annotations, enforced when static-checking is enabled:
*
* NS_STACK_CLASS: a class which must only be instantiated on the stack
*
* NS_MUST_OVERRIDE:
* a method which every immediate subclass of this class must
* override. A subclass override can itself be NS_MUST_OVERRIDE, in
* which case its own subclasses must override the method as well.
*
* This is similar to, but not the same as, marking a method pure
* virtual. It has no effect on the class in which the annotation
* appears, you can still provide a definition for the method, and
* it objects to the mere existence of a subclass that doesn't
* override the method. See examples in analysis/must-override.js.
*/
#ifdef NS_STATIC_CHECKING
#define NS_STACK_CLASS __attribute__((user("NS_stack")))
#define NS_OKONHEAP __attribute__((user("NS_okonheap")))
#define NS_SUPPRESS_STACK_CHECK __attribute__((user("NS_suppress_stackcheck")))
#define NS_MUST_OVERRIDE __attribute__((user("NS_must_override")))
#else
#define NS_STACK_CLASS
#define NS_OKONHEAP
#define NS_SUPPRESS_STACK_CHECK
#define NS_MUST_OVERRIDE
#endif
/**
* Attributes defined to help Dehydra GCC analysis.
*/
#ifdef NS_STATIC_CHECKING
# define NS_SCRIPTABLE __attribute__((user("NS_script")))
# define NS_INPARAM __attribute__((user("NS_inparam")))
# define NS_OUTPARAM __attribute__((user("NS_outparam")))
# define NS_INOUTPARAM __attribute__((user("NS_inoutparam")))
# define NS_OVERRIDE __attribute__((user("NS_override")))
#else
# define NS_SCRIPTABLE
# define NS_INPARAM
# define NS_OUTPARAM
# define NS_INOUTPARAM
# define NS_OVERRIDE
#endif
/*
* SEH exception macros.
*/
#ifdef HAVE_SEH_EXCEPTIONS
#define MOZ_SEH_TRY __try
#define MOZ_SEH_EXCEPT(expr) __except(expr)
#else
#define MOZ_SEH_TRY if(true)
#define MOZ_SEH_EXCEPT(expr) else
#endif
#endif /* nscore_h___ */