From patchwork Fri Aug 18 15:26:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 22216 Received: (qmail 119574 invoked by alias); 18 Aug 2017 15:26:08 -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 119525 invoked by uid 89); 18 Aug 2017 15:26:07 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.9 required=5.0 tests=BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RP_MATCHES_RCVD, SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com D0C8F4A6E1 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=fweimer@redhat.com Date: Fri, 18 Aug 2017 17:26:02 +0200 To: libc-alpha@sourceware.org Subject: [PATCH] assert: Support types without operator== (int) [BZ #21972] User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Message-Id: <20170818152602.3ED7141537DD0@oldenburg.str.redhat.com> From: fweimer@redhat.com (Florian Weimer) 2017-08-18 Florian Weimer [BZ #21972] * assert/assert.h (assert): Use static_cast (bool) for C++ in the pedantic warning check, to avoid a requirement for operator== (int). * assert/Makefile (tests): Add tst-assert-c++, tst-assert-g++. (CFLAGS-tst-assert-c++.o): Compile in C++11 mode. (CFLAGS-tst-assert-g++.o): Compile in GnU C++11 mode. (LDLIBS-tst-assert-c++, LDLIBS-tst-assert-g++): Link with libstdc++. * assert/tst-assert-c++.cc, assert/tst-assert-g++.cc: New files. diff --git a/assert/Makefile b/assert/Makefile index 1c3be9b01f..9ec1be81a9 100644 --- a/assert/Makefile +++ b/assert/Makefile @@ -25,6 +25,15 @@ include ../Makeconfig headers := assert.h routines := assert assert-perr __assert -tests := test-assert test-assert-perr +tests := test-assert test-assert-perr tst-assert-c++ tst-assert-g++ include ../Rules + +ifeq ($(have-cxx-thread_local),yes) +CFLAGS-tst-assert-c++.o = -std=c++11 +LDLIBS-tst-assert-c++ = -lstdc++ +CFLAGS-tst-assert-g++.o = -std=gnu++11 +LDLIBS-tst-assert-g++ = -lstdc++ +else +tests-unsupported += tst-assert-c++ tst-assert-g++ +endif diff --git a/assert/assert.h b/assert/assert.h index 6801cfeb10..4fea59e222 100644 --- a/assert/assert.h +++ b/assert/assert.h @@ -97,13 +97,25 @@ __END_DECLS required to support function pointers and bit fields in this context, and to suppress the evaluation of variable length arrays. */ -# define assert(expr) \ +# ifndef __cplusplus +# define assert(expr) \ ((void) sizeof ((expr) == 0), __extension__ ({ \ if (expr) \ ; /* empty */ \ else \ __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION); \ })) +# else /* __cplusplus */ +/* If EXPR is a type without a matching operrator== (int), the C + definition above does not work. */ +# define assert(expr) \ + ((void) sizeof (static_cast (expr)), __extension__ ({ \ + if (expr) \ + ; /* empty */ \ + else \ + __assert_fail (#expr, __FILE__, __LINE__, __ASSERT_FUNCTION); \ + })) +# endif # endif # ifdef __USE_GNU diff --git a/assert/tst-assert-c++.cc b/assert/tst-assert-c++.cc new file mode 100644 index 0000000000..c001bfff49 --- /dev/null +++ b/assert/tst-assert-c++.cc @@ -0,0 +1,72 @@ +/* Tests for interactions between C++ and assert. + Copyright (C) 2017 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 + +/* The C++ standard requires that if the assert argument is a constant + subexpression, then the assert itself is one, too. */ +constexpr int +check_constexpr () +{ + return (assert (true), 1); +} + +/* Objects of this class can be contextually converted to bool, but + cannot be compared to int. */ +struct no_int +{ + no_int () = default; + no_int (const no_int &) = delete; + + explicit operator bool () const + { + return true; + } +}; + +/* This class tests that operator== is not used by assert. */ +struct bool_and_int +{ + bool_and_int () = default; + bool_and_int (const no_int &) = delete; + + explicit operator bool () const + { + return true; + } + + template bool operator== (T) const; /* No definition. */ +}; + +static int +do_test () +{ + { + no_int value; + assert (value); + } + + { + bool_and_int value; + assert (value); + } + + return 0; +} + +#include diff --git a/assert/tst-assert-g++.cc b/assert/tst-assert-g++.cc new file mode 100644 index 0000000000..8c06402825 --- /dev/null +++ b/assert/tst-assert-g++.cc @@ -0,0 +1,19 @@ +/* Tests for interactions between C++ and assert. GNU C++11 version. + Copyright (C) 2017 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