From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 43551 invoked by alias); 23 Jul 2017 11:38:28 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 43309 invoked by uid 89); 23 Jul 2017 11:38:20 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,RCVD_IN_SORBS_SPAM,SPF_PASS autolearn=no version=3.3.2 spammy= X-HELO: mail-ua0-f171.google.com Received: from mail-ua0-f171.google.com (HELO mail-ua0-f171.google.com) (209.85.217.171) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Sun, 23 Jul 2017 11:38:19 +0000 Received: by mail-ua0-f171.google.com with SMTP id q25so43881188uah.1 for ; Sun, 23 Jul 2017 04:38:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=Ofe2Yl2iJG1iGLwx4Jvv7Wzt4dHNTTvqsi3ro/HhsxE=; b=ewlurv+MozX/o6C0EVUw68IrfUFxsCRW+N4I7zrP2aHDCrj/q3lIVdC+XIoYwctbEg 3iucnQdQPRf59D9fIi55Vi/0nV4RpQVt1bn/B684TVt+ME+mOmlJK22xOIqcjy3rm4ge 5ruEYv/aXIRUMpEXz3Y3H8G96SxWDWfa+U4HxDD5WWmxgRuYW3son5MjbZv7K7yHmyK5 sMScCB3KCulda1t30Q1mXmKB4nfPbQjyX91o6W5ISCT0FQBLaSd/AhlAKXpw8Ez2OZ/8 Y/rR1NygVmYvmpAADiqV6zFqotympC4SuZHBRvcH+2whZpNk+VPQr1TFHy6Cq03J7L99 llqA== X-Gm-Message-State: AIVw110gmxl1w1OSCyqgiP/N6NjAqsfyOUfwt9OJaO0t4LU06fgPYs9h Fo1yzwOU2Hmxn/F7Np5+3/Cp8GmP9tvO X-Received: by 10.176.71.19 with SMTP id h19mr6454458uac.138.1500809897663; Sun, 23 Jul 2017 04:38:17 -0700 (PDT) MIME-Version: 1.0 Received: by 10.176.95.16 with HTTP; Sun, 23 Jul 2017 04:38:17 -0700 (PDT) From: Irfan Adilovic Date: Sun, 23 Jul 2017 12:32:00 -0000 Message-ID: Subject: gcc-7.1.0/c++17/old-abi: empty stringstream invalid memory access To: cygwin@cygwin.com Content-Type: text/plain; charset="UTF-8" X-IsSubscribed: yes X-SW-Source: 2017-07/txt/msg00308.txt.bz2 I am reproducing here a bug report I filed to gcc's bugzilla against gcc-7.1.0: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81522 , in hopes of finding others who observed the same issue or who may have a solution. The bug only appears on Cygwin and only in c++17 mode with the old ABI. -- Irfan This trivial program: #include int main() { std::stringstream os; // same with ("") or (std::string()) os.str(); return 0; } causes an invalid memory access with gcc 7.1.0 (compiled from source), but only on Cygwin in c++17 mode with old ABI, and only if the stringstream is constructed empty. Changing any of those parameters no longer causes the issue. Thread 1 "string" received signal SIGABRT, Aborted. 0x00000001004018a0 in __gnu_cxx::new_allocator::deallocate (this=0x6, __p=0x3e8000003fc ) at /usr/local/gcc-7.1.0/include/c++/7.1.0/ext/new_allocator.h:125 125 ::operator delete(__p); (gdb) bt #0 0x00000001004018a0 in __gnu_cxx::new_allocator::deallocate (this=0x6, __p=0x3e8000003fc ) at /usr/local/gcc-7.1.0/include/c++/7.1.0/ext/new_allocator.h:125 #1 0x00000001800b25d2 in CreateEventW () from /usr/bin/cygwin1.dll #2 0x0000000000000130 in ?? () $ g++ -v Using built-in specs. COLLECT_GCC=g++ COLLECT_LTO_WRAPPER=/usr/local/gcc-7.1.0/libexec/gcc/x86_64-pc-cygwin/7.1.0/lto-wrapper.exe Target: x86_64-pc-cygwin Configured with: ../configure --prefix=/usr/local/gcc-7.1.0 --enable-threads=posix --enable-checking=release --enable-languages=c,c++ --build=x86_64-pc-cygwin --disable-multilib --with-default-libstdcxx-abi=gcc4-compatible Thread model: posix gcc version 7.1.0 (GCC) Sample program compiled with: $ g++ -std=c++17 -D_GLIBCXX_USE_CXX11_ABI=0 -ggdb -O0 string.cc -o string -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple