From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x842.google.com (mail-qt1-x842.google.com [IPv6:2607:f8b0:4864:20::842]) by sourceware.org (Postfix) with ESMTPS id 621CD3857C4A for ; Sat, 15 Aug 2020 23:38:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 621CD3857C4A Received: by mail-qt1-x842.google.com with SMTP id x12so9829596qtp.1 for ; Sat, 15 Aug 2020 16:38:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:mime-version; bh=SsgULJBgNfWMABP4hyUbSBdK1mpLOp2in6uboOdE+7A=; b=XWx+Tobki5P6Fm3RiSNA3LW6O90b7VXnOtGFiK/diyzvqEkphA89KbGsetjPWa+Srb XbmnDnnZfe8bkEG5QNrJEhDpcPgOPzzzySB3IkkSENtw6UAtlJWj7rrxcGeMCVu1J4Fn 7vZmRIZZufL9CoMDvXyA2dlGQKkVnvd38RxO3itB6UgmXI2g2PIWEJQS0rMcJ9Bm0f// FhTKpKs6Xpa+OOmD5ZeDFgjqboH2h4QQ8fdHXZdGmfwlh1qHvYaJRIb68i6FI2NRDEm6 3Pm9k9zGKG3sTQ8fi/tsqf2ARmsBby4kcZUfpomqt0zYxcdTk4XEp3L2mynsf48WYPXj 0RSA== X-Gm-Message-State: AOAM530TEvgVM9j+t0NmP7DCB4bE34Nsgben+FH/wMlxKOfWDhmbQlhp wnSF2Rs//MEPdunh7Hk7WVMa2fEOpN0= X-Google-Smtp-Source: ABdhPJyRg4Xsfmve7a7lrwixA1cdVIUgXh67zzGiSloUnn23TkLT/3F/zmTj4jOVLn+i5X2jaxIyjA== X-Received: by 2002:ac8:60c5:: with SMTP id i5mr8062461qtm.268.1597534682686; Sat, 15 Aug 2020 16:38:02 -0700 (PDT) Received: from davidm-laptop (hlfxns018gw-134-41-167-80.dhcp-dynamic.fibreop.ns.bellaliant.net. [134.41.167.80]) by smtp.gmail.com with ESMTPSA id d198sm12510058qke.129.2020.08.15.16.38.02 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 15 Aug 2020 16:38:02 -0700 (PDT) From: David McFarland To: cygwin@cygwin.com Subject: unhandled C++ exceptions not propagating Date: Sat, 15 Aug 2020 20:38:01 -0300 Message-ID: MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-1.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 15 Aug 2020 23:38:04 -0000 I was just debugging a c++ app (b2 build system from boost), and noticed that it would appear to exit unexpectedly without an error. This turned out to be when an unhandled C++ exception was thrown. On a fresh install of cygwin with gcc-g++, this program will throw an exception from the std::string constructor: c++ -x c++ - < int main() { std::string str(nullptr); return 0; } END When it's executed from the shell it returns zero, but execution stops at the exception. $ ./a; echo $? 0 When executed under gdb, the exception is caught, and the process exits non-zero when continued: (gdb) r Starting program: /home/corngood/a [New Thread 4300.0x1390] [New Thread 4300.0x1d24] [New Thread 4300.0x1d48] [New Thread 4300.0x80c] gdb: unknown target exception 0x20474343 at 0x7ff8d2cfa799 Thread 1 "a" received signal ?, Unknown signal. 0x00007ff8d2cfa799 in RaiseException () from /cygdrive/c/WINDOWS/System32/KERNELBASE.dll (gdb) c Continuing. [Thread 4300.0x1d24 exited with code 541541187] [Thread 4300.0x1870 exited with code 541541187] [Thread 4300.0x1d48 exited with code 541541187] [Thread 4300.0x1390 exited with code 541541187] [Inferior 1 (process 4300) exited with code 04021641503] (gdb) When executed under strace, it exits with an error as expected: $ strace -o /dev/null a; echo $? 67 That's as far as I've investigated so far.