From patchwork Thu Feb 1 20:37:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Myers X-Patchwork-Id: 25740 Received: (qmail 118780 invoked by alias); 1 Feb 2018 20:37:19 -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 118764 invoked by uid 89); 1 Feb 2018 20:37:18 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-24.5 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_PASS, URIBL_RED autolearn=ham version=3.3.2 spammy=m31 X-HELO: relay1.mentorg.com Date: Thu, 1 Feb 2018 20:37:11 +0000 From: Joseph Myers To: Subject: Correct type of SSIZE_MAX for 32-bit (bug 13575) Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 X-ClientProxiedBy: svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) Bug 13575 reports that SSIZE_MAX is wrongly defined as LONG_MAX on 32-bit systems where ssize_t is defined as int (which is most 32-bit systems supported by glibc). This patch fixes the definition, using a conditional on __WORDSIZE32_SIZE_ULONG to determine the appropriate type in the 32-bit case. Formally ssize_t need not be the signed type corresponding to size_t, but as it is for all current glibc configurations, there is no need for a new macro different from the one used for defining SIZE_MAX. A testcase is added for both the type and the value of SSIZE_MAX. There is a relevant peculiarity in sysdeps/unix/sysv/linux/s390/bits/typesizes.h: #if defined __GNUC__ && __GNUC__ <= 2 /* Compatibility with g++ 2.95.x. */ #define __SSIZE_T_TYPE __SWORD_TYPE #else /* size_t is unsigned long int on s390 -m31. */ #define __SSIZE_T_TYPE __SLONGWORD_TYPE #endif This has the effect that for GCC 2 for s390, ssize_t does not match __WORDSIZE32_SIZE_ULONG. I don't think such a conditional on the GCC version makes sense - to have a well-defined ABI, the choices of standard types should not depend on the GCC version. It's also the case that upstream GCC 2.95 did not support s390, and glibc headers don't in general try to support past development GCC versions - only actual releases and current mainline development. But whether or not that GCC 2 case should be removed (with or without a NEWS entry for such a change), this patch does not result in any changes for s390; the value is always still LONG_MAX in the s390 case because __WORDSIZE32_SIZE_ULONG is always defined for 32-bit s390. I don't think any such oddity in code only active for unofficial or unreleased old compiler versions should block closing the present bug as fixed once this patch is in. Tested for x86_64 and x86, and with build-many-glibcs.py. 2018-02-01 Joseph Myers [BZ #13575] * posix/bits/posix1_lim.h: Include . [!SSIZE_MAX && !(__WORDSIZE == 64 || __WORDSIZE32_SIZE_ULONG)] (SSIZE_MAX): Define to INT_MAX. * posix/test-ssize-max.c: New file. * posix/Makefile (tests): Add test-ssize-max. diff --git a/posix/Makefile b/posix/Makefile index 83b3d74..51dcf12 100644 --- a/posix/Makefile +++ b/posix/Makefile @@ -95,7 +95,7 @@ tests := test-errno tstgetopt testfnm runtests runptests \ tst-posix_spawn-fd tst-posix_spawn-setsid \ tst-posix_fadvise tst-posix_fadvise64 \ tst-sysconf-empty-chroot tst-glob_symlinks tst-fexecve \ - tst-glob-tilde + tst-glob-tilde test-ssize-max tests-internal := bug-regex5 bug-regex20 bug-regex33 \ tst-rfc3484 tst-rfc3484-2 tst-rfc3484-3 \ tst-glob_lstat_compat diff --git a/posix/bits/posix1_lim.h b/posix/bits/posix1_lim.h index 90066ff..18ac47f 100644 --- a/posix/bits/posix1_lim.h +++ b/posix/bits/posix1_lim.h @@ -24,6 +24,7 @@ #ifndef _BITS_POSIX1_LIM_H #define _BITS_POSIX1_LIM_H 1 +#include /* These are the standard-mandated minimum values. */ @@ -161,7 +162,14 @@ #ifndef SSIZE_MAX -# define SSIZE_MAX LONG_MAX +/* ssize_t is not formally required to be the signed type + corresponding to size_t, but it is for all configurations supported + by glibc. */ +# if __WORDSIZE == 64 || __WORDSIZE32_SIZE_ULONG +# define SSIZE_MAX LONG_MAX +# else +# define SSIZE_MAX INT_MAX +# endif #endif diff --git a/posix/test-ssize-max.c b/posix/test-ssize-max.c new file mode 100644 index 0000000..12e3d8e --- /dev/null +++ b/posix/test-ssize-max.c @@ -0,0 +1,36 @@ +/* Test SSIZE_MAX value and type. + Copyright (C) 2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include + +ssize_t x; +extern __typeof (SSIZE_MAX) x; +_Static_assert (SSIZE_MAX == (sizeof (ssize_t) == sizeof (int) + ? INT_MAX + : LONG_MAX), + "value of SSIZE_MAX"); + +static int +do_test (void) +{ + /* This is a compilation test. */ + return 0; +} + +#include