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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 592E53858C74 for ; Thu, 9 Mar 2023 18:00:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 592E53858C74 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678384828; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8Z+kjmm3hRvfbJO2CuZmKUvMuCwDsdgFOr7FMHDgJIk=; b=RMdaOXbhyjE9W6+Pfc/06arJhj8GIfqdw4GSt2pRNBh0vPGFvH623tWRrhVjzgdYpyp6Re RYV9zWol8JagRN0urwPrXqjU9f1FL3u80nCyYYi2xAE+JN4Fe6mtiM7aJ/9gqCN3wPQctX b9FqRy4Ea+fM/pZIk85pD+HUs7DLTDk= Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-207-QWkQrmNjMY27EgS2B7LeuA-1; Thu, 09 Mar 2023 13:00:18 -0500 X-MC-Unique: QWkQrmNjMY27EgS2B7LeuA-1 Received: by mail-lf1-f69.google.com with SMTP id p8-20020a056512234800b004dda0f69233so859293lfu.13 for ; Thu, 09 Mar 2023 10:00:18 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678384817; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=8Z+kjmm3hRvfbJO2CuZmKUvMuCwDsdgFOr7FMHDgJIk=; b=bACbj27H4w76xPkbyujLJStWMIjwrPiLvSJf6VzjxPAKnHGpuUG/fMgE1eVqeyoXhv xs9K5AN6Yy0YdzwY73MfQ9jebsZbObAVQYihUhGxhqy/ChSrff6EBRrfSMg3UiySHcuU MLlcrS0xRuXQgnl5Gw6aENj6ZFZyzKlQtEAt+ZsIFXNi4NhmyZrgPFaV9nZNL8S6v+NF vwP69x54xZ9koe7JVYJQvSReILqIIndRL9v2wJTR0RLZWckqGnBRhT2grIOD7cEqquNp NBMVM8jVKT9kxpwWS9r0cYVbmCnz0Pxp2MARcOll8Yj56kck7q64C8SgciExUjP5pdmv WWbQ== X-Gm-Message-State: AO0yUKUVH34gocI7Ufjgiv3HhYBvrRVhTDSg/bqKkjmu4gaq2LNrHa4z 4495XTTd6Ypq+2bVRHqh6VHTMXnkg4m3FmyczazYpYd3SwlnJBcHQlTVQkSIYc510ZgxN+kJHvh lTTBW3of/no95hzAt1zUi8dNB4Ozas059lg== X-Received: by 2002:a19:7404:0:b0:4db:173e:812a with SMTP id v4-20020a197404000000b004db173e812amr7219391lfe.8.1678384816814; Thu, 09 Mar 2023 10:00:16 -0800 (PST) X-Google-Smtp-Source: AK7set+paAGfo7zXvp7haDovsgtAJmYPH6PgfPB3J2eZhhK+xKn5EPxTZ6huL5RtgdD2XVw6EDuHvnuvSuB72ooa1vA= X-Received: by 2002:a19:7404:0:b0:4db:173e:812a with SMTP id v4-20020a197404000000b004db173e812amr7219383lfe.8.1678384816505; Thu, 09 Mar 2023 10:00:16 -0800 (PST) MIME-Version: 1.0 References: <20230308151133.152110-1-ppalka@redhat.com> In-Reply-To: <20230308151133.152110-1-ppalka@redhat.com> From: Jonathan Wakely Date: Thu, 9 Mar 2023 18:00:05 +0000 Message-ID: Subject: Re: [PATCH] libstdc++: Implement LWG 3820/3849 changes to cartesian_product_view To: Patrick Palka Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-12.1 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_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On Wed, 8 Mar 2023 at 15:13, Patrick Palka via Libstdc++ wrote: > > The LWG 3820 testcase revealed a bug in _M_advance, which this patch > also fixes. > > Tested on x86_64-pc-linux-gnu, does this look OK for trunk? OK > > libstdc++-v3/ChangeLog: > > * include/std/ranges > (cartesian_product_view::_Iterator::_Iterator): Remove > constraint on default constructor as per LWG 3849. > (cartesian_product_view::_Iterator::_M_prev): Adjust position > of _Nm > 0 test as per LWG 3820. > (cartesian_product_view::_Iterator::_M_advance): Perform bound > checking only on sized cartesian products. > * testsuite/std/ranges/cartesian_product/1.cc (test08): New test. > --- > libstdc++-v3/include/std/ranges | 23 +++++++++++-------- > .../std/ranges/cartesian_product/1.cc | 9 ++++++++ > 2 files changed, 22 insertions(+), 10 deletions(-) > > diff --git a/libstdc++-v3/include/std/ranges b/libstdc++-v3/include/std/ranges > index 67566c6ebcf..14f38727198 100644 > --- a/libstdc++-v3/include/std/ranges > +++ b/libstdc++-v3/include/std/ranges > @@ -8225,7 +8225,7 @@ namespace views::__adaptor > range_reference_t<__maybe_const_t<_Const, _Vs>>...>; > using difference_type = decltype(cartesian_product_view::_S_difference_type()); > > - _Iterator() requires forward_range<__maybe_const_t<_Const, _First>> = default; > + _Iterator() = default; > > constexpr > _Iterator(_Iterator __i) > @@ -8390,12 +8390,12 @@ namespace views::__adaptor > _M_prev() > { > auto& __it = std::get<_Nm>(_M_current); > - if (__it == ranges::begin(std::get<_Nm>(_M_parent->_M_bases))) > - { > - __it = __detail::__cartesian_common_arg_end(std::get<_Nm>(_M_parent->_M_bases)); > - if constexpr (_Nm > 0) > + if constexpr (_Nm > 0) > + if (__it == ranges::begin(std::get<_Nm>(_M_parent->_M_bases))) > + { > + __it = __detail::__cartesian_common_arg_end(std::get<_Nm>(_M_parent->_M_bases)); > _M_prev<_Nm - 1>(); > - } > + } > --__it; > } > > @@ -8416,10 +8416,13 @@ namespace views::__adaptor > if constexpr (_Nm == 0) > { > #ifdef _GLIBCXX_ASSERTIONS > - auto __size = ranges::ssize(__r); > - auto __begin = ranges::begin(__r); > - auto __offset = __it - __begin; > - __glibcxx_assert(__offset + __x >= 0 && __offset + __x <= __size); > + if constexpr (sized_range<__maybe_const_t<_Const, _First>>) > + { > + auto __size = ranges::ssize(__r); > + auto __begin = ranges::begin(__r); > + auto __offset = __it - __begin; > + __glibcxx_assert(__offset + __x >= 0 && __offset + __x <= __size); > + } > #endif > __it += __x; > } > diff --git a/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc b/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc > index f52c2b96d58..56ff3d152c6 100644 > --- a/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc > +++ b/libstdc++-v3/testsuite/std/ranges/cartesian_product/1.cc > @@ -201,6 +201,14 @@ test07() > VERIFY( i == 5 ); > } > > +void > +test08() > +{ > + // LWG 3820 > + auto r = std::views::cartesian_product(std::views::iota(0)); > + r.begin() += 3; // hard error > +} > + > int > main() > { > @@ -211,4 +219,5 @@ main() > test05(); > static_assert(test06()); > test07(); > + test08(); > } > -- > 2.40.0.rc0.57.g454dfcbddf >