From patchwork Fri May 13 13:26:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Zack Weinberg X-Patchwork-Id: 12233 Received: (qmail 105856 invoked by alias); 13 May 2016 13:26:29 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 105761 invoked by uid 89); 13 May 2016 13:26:29 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.5 required=5.0 tests=AWL, BAYES_00, RP_MATCHES_RCVD, SPF_PASS autolearn=ham version=3.3.2 spammy=misuse, SUCCESS, gallagher, maj X-HELO: mailbackend.panix.com From: Zack Weinberg To: libc-alpha@sourceware.org Subject: [PATCH 4/4] Deprecate inclusion of by Date: Fri, 13 May 2016 09:26:16 -0400 Message-Id: In-Reply-To: References: MIME-Version: 1.0 In-Reply-To: References: The macros defined by are not part of POSIX nor XSI, and their names have been found frequently to collide with user code; see for instance glibc bug 19239 and Red Hat bug 130601. includes under _GNU_SOURCE, and C++ code presently cannot avoid being compiled under _GNU_SOURCE, exacerbating the problem. ChangeLog: * NEWS: Inclusion of by is deprecated. * misc/sys/sysmacros.h: If __SYSMACROS_DEPRECATED_INCLUSION is defined, define major, minor, and makedev to issue deprecation warnings on use. If __SYSMACROS_DEPRECATED_INCLUSION is *not* defined, suppress previously-activated deprecation warnings for these macros and prevent subsequent inclusions of this header from having any effect. * posix/sys/types.h: Define __SYSMACROS_DEPRECATED_INCLUSION before including , and undefine it again afterward. --- NEWS | 15 ++++++++++ misc/sys/sysmacros.h | 82 +++++++++++++++++++++++++++++++++++++++------------- posix/sys/types.h | 8 ++++- 3 files changed, 84 insertions(+), 21 deletions(-) diff --git a/NEWS b/NEWS index b3fd3cc..e8d3b93 100644 --- a/NEWS +++ b/NEWS @@ -33,6 +33,21 @@ Version 2.24 group: files [SUCCESS=merge] nis Implemented by Stephen Gallagher (Red Hat). +* The inclusion of by is deprecated. This + means that in a future release, the macros “major”, “minor”, and “makedev” + will only be available from . + + The macros defined by are not part of POSIX nor XSI, + and their names have been found frequently to collide with user code; + see for instance glibc bug 19239 and Red Hat bug 130601. + includes under _GNU_SOURCE, and C++ code presently cannot + avoid being compiled under _GNU_SOURCE, exacerbating the problem. + + Code that does not need these macros should #undef them after including + ; this will also improve portability to BSD-derived systems. + Code that *does* need these macros should include , and then + include if __GLIBC__ is defined. + Security related changes: * An unnecessary stack copy in _nss_dns_getnetbyname_r was removed. It diff --git a/misc/sys/sysmacros.h b/misc/sys/sysmacros.h index edc6bac..3dc6133 100644 --- a/misc/sys/sysmacros.h +++ b/misc/sys/sysmacros.h @@ -16,25 +16,59 @@ License along with the GNU C Library; if not, see . */ +#ifndef _SYS_SYSMACROS_H_OUTER + +#ifndef __SYSMACROS_DEPRECATED_INCLUSION +# define _SYS_SYSMACROS_H_OUTER 1 +#endif + +/* If is included after , these macros + will already be defined, and we need to redefine them without the + deprecation warnings. (If they are included in the opposite order, + the outer #ifndef will suppress this entire file and the macros + will be usable without warnings.) */ +#undef major +#undef minor +#undef makedev + +/* This is the macro that must be defined to satisfy the misuse check + in bits/sysmacros.h. */ #ifndef _SYS_SYSMACROS_H -#define _SYS_SYSMACROS_H 1 +# define _SYS_SYSMACROS_H 1 -#include -#include -#include +# include +# include +# include -#define __SYSMACROS_DECL(rtype, name, proto) \ - extern rtype gnu_dev_##name proto __THROW __attribute_const__; +/* The extra "\n " moves gcc's [-Wdeprecated-declarations] annotation + onto the next line. */ +# define __SYSMACROS_DEPRECATION_MSG(symbol) \ + "\n In the GNU C Library, `" #symbol "' is defined by ." \ + "\n For historical compatibility, it is currently defined by" \ + "\n as well, but we plan to remove this soon." \ + "\n To use `" #symbol "', include directly." \ + "\n If you did not intend to use a system-defined macro `" #symbol "'," \ + "\n you should #undef it after including ." \ + "\n " -#ifdef __USE_EXTERN_INLINES -# define __SYSMACROS_IMPL(rtype, name, proto, body) \ - __SYSMACROS_DECL (rtype, name, proto) \ - __extension__ __extern_inline __attribute_const__ rtype \ - __NTH (gnu_dev_##name proto) { body } -#else -# define __SYSMACROS_IMPL(rtype, name, proto, expr) \ - __SYSMACROS_DECL (rtype, name, proto) -#endif +# define __SYSMACROS_DECL(rtype, name, proto) \ + extern rtype gnu_dev_##name proto __THROW __attribute_const__; \ + extern rtype __REDIRECT_NTH (__##name##_from_sys_types, proto, \ + gnu_dev_##name) \ + __attribute_const__ \ + __attribute_deprecated_msg__ (__SYSMACROS_DEPRECATION_MSG (name)); + +# ifdef __USE_EXTERN_INLINES +# define __SYSMACROS_IMPL(rtype, name, proto, body) \ + __SYSMACROS_DECL (rtype, name, proto) \ + __extension__ __extern_inline __attribute_const__ rtype \ + __NTH (gnu_dev_##name proto) { body } \ + __extension__ __extern_inline __attribute_const__ rtype \ + __NTH (__##name##_from_sys_types proto) { body } +# else +# define __SYSMACROS_IMPL(rtype, name, proto, expr) \ + __SYSMACROS_DECL (rtype, name, proto) +# endif __BEGIN_DECLS @@ -46,11 +80,19 @@ __SYSMACROS_IMPL (__dev_t, makedev, __END_DECLS -#undef __SYSMACROS_IMPL -#undef __SYSMACROS_DECL +# undef __SYSMACROS_IMPL +# undef __SYSMACROS_DECL + +# endif /* _SYS_SYSMACROS_H */ -#define major(dev) gnu_dev_major (dev) -#define minor(dev) gnu_dev_minor (dev) -#define makedev(maj, min) gnu_dev_makedev (maj, min) +#ifdef __SYSMACROS_DEPRECATED_INCLUSION +# define major(dev) __major_from_sys_types (dev) +# define minor(dev) __minor_from_sys_types (dev) +# define makedev(maj, min) __makedev_from_sys_types (maj, min) +#else +# define major(dev) gnu_dev_major (dev) +# define minor(dev) gnu_dev_minor (dev) +# define makedev(maj, min) gnu_dev_makedev (maj, min) +#endif #endif /* sys/sysmacros.h */ diff --git a/posix/sys/types.h b/posix/sys/types.h index a728567..83dadcd 100644 --- a/posix/sys/types.h +++ b/posix/sys/types.h @@ -218,8 +218,14 @@ typedef int register_t __attribute__ ((__mode__ (__word__))); /* It also defines `fd_set' and the FD_* macros for `select'. */ # include -/* BSD defines these symbols, so we follow. */ +/* BSD defines `major', `minor', and `makedev' in this header. + However, these symbols are likely to collide with user code, so we are + going to stop defining them here in an upcoming release. Code that needs + these macros should include directly. Code that does + not need these macros should #undef them after including this header. */ +# define __SYSMACROS_DEPRECATED_INCLUSION # include +# undef __SYSMACROS_DEPRECATED_INCLUSION #endif /* Use misc. */