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 ESMTPS id AF0BA3858D3C for ; Tue, 31 May 2022 12:56:14 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AF0BA3858D3C Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-6-10bD86RtOpm6tXdvpbc6Wg-1; Tue, 31 May 2022 08:56:12 -0400 X-MC-Unique: 10bD86RtOpm6tXdvpbc6Wg-1 Received: by mail-qv1-f71.google.com with SMTP id x18-20020a0ce0d2000000b0046458e0e18bso2412571qvk.1 for ; Tue, 31 May 2022 05:56:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:date:to:cc:subject:in-reply-to:message-id :references:mime-version; bh=033oh5fUE+OKCGBrPZqUk/uxpBiz+yS9uAX9cv4jh6Y=; b=2hoiCU7cZRpzVJA1WR5K8aFhqgTLoBm3S5oywc1o/Q+KX0l4lZSCm/7J4mjPsvRZhS 0vEHD34ZqvHZR4gNI307CqzvUv/UxF5ZJ13nxWfzUBlOwgAeUj874FR7XjY4T/P1JEop cXjz23+TEE1vD7Y2aDCLzhyoFKElTca3xgzfaS9iI406J3PvjPKebfbpqPD4GbL4ORzB Ee+IKCgWmwsIXKX/kagv8ruoOgoy8y9Ha42DEOP5Vff9N8fTswICO/huA9wnqKbackHr kdLp/F8dh9zwVAARQxYBR8UUfrKqCPQ/aQE6fy9wjsc6zxxCD4msEIhTBS1fbHljPCue p5iQ== X-Gm-Message-State: AOAM530f1LxHr+sg5vq7YmKecHxwPEtgZLIdyctVwg+gT5Du9voTSihu 5zw2gi5FkzolO9RaAdw5mYe5iDp+x0dJnxbfwKOKTcOchjiK6lbRFFDyN1U7X8cHrh6b6/JTgiK b/C0e+cRB2LDZOYUUnA== X-Received: by 2002:a05:620a:3d0:b0:6a3:6346:d962 with SMTP id r16-20020a05620a03d000b006a36346d962mr34103425qkm.260.1654001772241; Tue, 31 May 2022 05:56:12 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyWcDruDmkezRLrimqVMB3czj7eU3Uc9rkiTsQx8UpmUAAPgzrnWdqX/hlSVwspoEuliLKyWw== X-Received: by 2002:a05:620a:3d0:b0:6a3:6346:d962 with SMTP id r16-20020a05620a03d000b006a36346d962mr34103404qkm.260.1654001771902; Tue, 31 May 2022 05:56:11 -0700 (PDT) Received: from [192.168.1.130] (ool-457670bb.dyn.optonline.net. [69.118.112.187]) by smtp.gmail.com with ESMTPSA id m2-20020ae9e702000000b0069fc13ce226sm8903284qka.87.2022.05.31.05.56.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 31 May 2022 05:56:11 -0700 (PDT) From: Patrick Palka X-Google-Original-From: Patrick Palka Date: Tue, 31 May 2022 08:56:10 -0400 (EDT) To: Jason Merrill cc: Patrick Palka , gcc-patches@gcc.gnu.org Subject: Re: [PATCH] c++: don't substitute TEMPLATE_PARM_CONSTRAINT [PR100374] In-Reply-To: <89dc1f48-0c65-a4e7-8791-3d541e074bb7@redhat.com> Message-ID: <9366f773-368b-2957-c3ff-0fb8d17c240d@idea> References: <20220527180543.2908762-1-ppalka@redhat.com> <89dc1f48-0c65-a4e7-8791-3d541e074bb7@redhat.com> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.9 required=5.0 tests=BAYES_00, BODY_8BITS, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 May 2022 12:56:17 -0000 On Sun, 29 May 2022, Jason Merrill wrote: > On 5/29/22 22:10, Jason Merrill wrote: > > On 5/27/22 14:05, Patrick Palka wrote: > > > This makes us avoid substituting into the TEMPLATE_PARM_CONSTRAINT of > > > each template parameter except as necessary for (friend) declaration > > > matching, like we already do for the overall TEMPLATE_PARMS_CONSTRAINTS > > > of a template parameter list. > > > > > > Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for > > > trunk and perhaps 12.2?  Also tested on range-v3 and cmcstl2. > > > > Are there already tests that cover the friend cases? Yes, by cpp2a/concepts-friend{2,3,7}.C I think. > > Also, don't you also need to handle specialization of partial instantiations? Hmm, do you have an example? IIUC we call tsubst_friend_function and tsubst_friend_class only from instantiate_class_template_1, which always uses the most general template and full template argument set to instantiate any friend declarations. So friend declarations are never partially instantiated I think. (And IIUC non-friends are irrelevant here since we don't ever want to substitute their constraints outside of satisfaction.) > > > >     PR c++/100374 > > > > > > gcc/cp/ChangeLog: > > > > > >     * pt.cc (tsubst_each_template_parm_constraint): Define. > > >     (tsubst_friend_function): Use it. > > >     (tsubst_friend_class): Use it. > > >     (tsubst_template_parm): Don't substitute TEMPLATE_PARM_CONSTRAINT. > > > > > > gcc/testsuite/ChangeLog: > > > > > >     * g++.dg/cpp2a/concepts-template-parm11.C: New test. > > > --- > > >   gcc/cp/pt.cc                                  | 35 ++++++++++++++++--- > > >   .../g++.dg/cpp2a/concepts-template-parm11.C   | 16 +++++++++ > > >   2 files changed, 47 insertions(+), 4 deletions(-) > > >   create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-template-parm11.C > > > > > > diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc > > > index 24bbe2f4060..ec168234325 100644 > > > --- a/gcc/cp/pt.cc > > > +++ b/gcc/cp/pt.cc > > > @@ -184,6 +184,7 @@ static int unify_pack_expansion (tree, tree, tree, > > >                    tree, unification_kind_t, bool, bool); > > >   static tree copy_template_args (tree); > > >   static tree tsubst_template_parms (tree, tree, tsubst_flags_t); > > > +static void tsubst_each_template_parm_constraint (tree, tree, > > > tsubst_flags_t); > > >   tree most_specialized_partial_spec (tree, tsubst_flags_t); > > >   static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int); > > >   static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree); > > > @@ -11254,7 +11255,12 @@ tsubst_friend_function (tree decl, tree args) > > >         tree parms = DECL_TEMPLATE_PARMS (new_friend); > > >         tree treqs = TEMPLATE_PARMS_CONSTRAINTS (parms); > > >         treqs = maybe_substitute_reqs_for (treqs, new_friend); > > > -      TEMPLATE_PARMS_CONSTRAINTS (parms) = treqs; > > > +      if (treqs != TEMPLATE_PARMS_CONSTRAINTS (parms)) > > > +    { > > > +      TEMPLATE_PARMS_CONSTRAINTS (parms) = treqs; > > > +      /* As well as each TEMPLATE_PARM_CONSTRAINT.  */ > > > +      tsubst_each_template_parm_constraint (parms, args, > > > tf_warning_or_error); > > > +    } > > >       } > > >     /* The mangled name for the NEW_FRIEND is incorrect.  The function > > > @@ -11500,6 +11506,8 @@ tsubst_friend_class (tree friend_tmpl, tree args) > > >       { > > >         tree parms = tsubst_template_parms (DECL_TEMPLATE_PARMS > > > (friend_tmpl), > > >                             args, tf_warning_or_error); > > > +      tsubst_each_template_parm_constraint (parms, args, > > > +                        tf_warning_or_error); > > >             location_t saved_input_location = input_location; > > >             input_location = DECL_SOURCE_LOCATION (friend_tmpl); > > >             tree cons = get_constraints (tmpl); > > > @@ -11534,6 +11542,8 @@ tsubst_friend_class (tree friend_tmpl, tree args) > > >                          DECL_FRIEND_CONTEXT (friend_tmpl)); > > >             --processing_template_decl; > > >             set_constraints (tmpl, ci); > > > +          tsubst_each_template_parm_constraint (DECL_TEMPLATE_PARMS > > > (tmpl), > > > +                            args, tf_warning_or_error); > > >           } > > >         /* Inject this template into the enclosing namspace scope.  */ > > > @@ -13656,7 +13666,6 @@ tsubst_template_parm (tree t, tree args, > > > tsubst_flags_t complain) > > >     default_value = TREE_PURPOSE (t); > > >     parm_decl = TREE_VALUE (t); > > > -  tree constraint = TEMPLATE_PARM_CONSTRAINTS (t); > > >     parm_decl = tsubst (parm_decl, args, complain, NULL_TREE); > > >     if (TREE_CODE (parm_decl) == PARM_DECL > > > @@ -13664,13 +13673,31 @@ tsubst_template_parm (tree t, tree args, > > > tsubst_flags_t complain) > > >       parm_decl = error_mark_node; > > >     default_value = tsubst_template_arg (default_value, args, > > >                          complain, NULL_TREE); > > > -  constraint = tsubst_constraint (constraint, args, complain, NULL_TREE); > > >     tree r = build_tree_list (default_value, parm_decl); > > > -  TEMPLATE_PARM_CONSTRAINTS (r) = constraint; > > > +  TEMPLATE_PARM_CONSTRAINTS (r) = TEMPLATE_PARM_CONSTRAINTS (t); > > >     return r; > > >   } > > > +/* Substitute in-place the TEMPLATE_PARM_CONSTRAINT of each template > > > +   parameter in PARMS for sake of declaration matching.  */ > > > + > > > +static void > > > +tsubst_each_template_parm_constraint (tree parms, tree args, > > > +                      tsubst_flags_t complain) > > > +{ > > > +  ++processing_template_decl; > > > +  for (; parms; parms = TREE_CHAIN (parms)) > > > +    { > > > +      tree level = TREE_VALUE (parms); > > > +      for (tree parm : tree_vec_range (level)) > > > +    TEMPLATE_PARM_CONSTRAINTS (parm) > > > +      = tsubst_constraint (TEMPLATE_PARM_CONSTRAINTS (parm), args, > > > +                   complain, NULL_TREE); > > > +    } > > > +  --processing_template_decl; > > > +} > > > + > > >   /* Substitute the ARGS into the indicated aggregate (or enumeration) > > >      type T.  If T is not an aggregate or enumeration type, it is > > >      handled as if by tsubst.  IN_DECL is as for tsubst.  If > > > diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-template-parm11.C > > > b/gcc/testsuite/g++.dg/cpp2a/concepts-template-parm11.C > > > new file mode 100644 > > > index 00000000000..f70de341a07 > > > --- /dev/null > > > +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-template-parm11.C > > > @@ -0,0 +1,16 @@ > > > +// PR c++/100374 > > > +// { dg-do compile { target c++20 } } > > > + > > > +template > > > +concept C = true; > > > + > > > +template > > > +struct A { > > > +  template U> > > > +  void f(); > > > + > > > +  template U> > > > +  struct B; > > > +}; > > > + > > > +template struct A; > > > >