From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTP id E753039B707C for ; Thu, 19 Aug 2021 12:03:18 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E753039B707C Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-600-jpiW_71lNS-aoo_4h15qcg-1; Thu, 19 Aug 2021 08:03:17 -0400 X-MC-Unique: jpiW_71lNS-aoo_4h15qcg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 21A6A1018F64; Thu, 19 Aug 2021 12:03:16 +0000 (UTC) Received: from localhost (unknown [10.33.36.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id C60AB81F7B; Thu, 19 Aug 2021 12:03:15 +0000 (UTC) Date: Thu, 19 Aug 2021 13:03:15 +0100 From: Jonathan Wakely To: libstdc++@gcc.gnu.org, gcc-patches@gcc.gnu.org Subject: [committed] libstdc++: Improve overflow check for file timestamps Message-ID: MIME-Version: 1.0 X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/mixed; boundary="h4w2zuGEwv+hYNTG" Content-Disposition: inline X-Spam-Status: No, score=-14.2 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Aug 2021 12:03:20 -0000 --h4w2zuGEwv+hYNTG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline The current code assumes that system_clock::duration is nanoseconds, and also performs a value-changing conversion from nanoseconds::max() to double (which doesn't matter after dividing by 1e9, but triggers a warning with Clang nonetheless). A better solution is to use system_clock::duration::max() and perform the comparison entirely using the std::chrono types, rather than with dimensionless arithmetic types. This doesn't address the FIXME in the function, so the overflow check still rejects some values that could be represented by the file_clock. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * src/filesystem/ops-common.h (filesystem::file_time): Improve overflow check by using system_clock::duration::max(). Tested powerpc64le-linux. Committed to trunk. --h4w2zuGEwv+hYNTG Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="patch.txt" commit 65441d8fc3c132a58c8bef6faefa2bc25e82a913 Author: Jonathan Wakely Date: Thu Aug 19 11:03:01 2021 libstdc++: Improve overflow check for file timestamps The current code assumes that system_clock::duration is nanoseconds, and also performs a value-changing conversion from nanoseconds::max() to double (which doesn't matter after dividing by 1e9, but triggers a warning with Clang nonetheless). A better solution is to use system_clock::duration::max() and perform the comparison entirely using the std::chrono types, rather than with dimensionless arithmetic types. This doesn't address the FIXME in the function, so the overflow check still rejects some values that could be represented by the file_clock. Signed-off-by: Jonathan Wakely libstdc++-v3/ChangeLog: * src/filesystem/ops-common.h (filesystem::file_time): Improve overflow check by using system_clock::duration::max(). diff --git a/libstdc++-v3/src/filesystem/ops-common.h b/libstdc++-v3/src/filesystem/ops-common.h index 304e5b263fb..bf26c06b7b5 100644 --- a/libstdc++-v3/src/filesystem/ops-common.h +++ b/libstdc++-v3/src/filesystem/ops-common.h @@ -229,7 +229,7 @@ namespace __gnu_posix // (This only applies to the C++17 Filesystem library, because for the // Filesystem TS we don't have a distinct __file_clock, we just use the // system clock for file timestamps). - if (s >= (nanoseconds::max().count() / 1e9)) + if (seconds{s} >= floor(system_clock::duration::max())) { ec = std::make_error_code(std::errc::value_too_large); // EOVERFLOW return system_clock::time_point::min(); --h4w2zuGEwv+hYNTG--