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 AAF773858D37 for ; Thu, 6 Oct 2022 17:20:49 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org AAF773858D37 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=1665076849; h=from:from:reply-to: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=QbbNp/cmACE4Wa0JQN35B40bEDlVUlkOOy+YpxRjGo8=; b=DmY68oKgBF2H8WET379xFTtMuu0q78HwcNkF10AiH9FSLLCmuJg1vhOLFO0RWVYnDaChH3 icwjSZoXQfl5x+dmxeKRnecNDpmbaCYoLo1w0Lvna00Y/2IFV0wBSebgUfY2XX5Cf6653d jUmETsFVaDbrmwVC8OFhtFnUEMiAh2o= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-550-mG9ITZCfMjioXKvdLhbOOw-1; Thu, 06 Oct 2022 13:20:48 -0400 X-MC-Unique: mG9ITZCfMjioXKvdLhbOOw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D3D7E868A3A for ; Thu, 6 Oct 2022 17:20:47 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.194]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7838D1121333; Thu, 6 Oct 2022 17:20:47 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 296HKjTw1803805 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Thu, 6 Oct 2022 19:20:45 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 296HKiBD1803804; Thu, 6 Oct 2022 19:20:44 +0200 Date: Thu, 6 Oct 2022 19:20:44 +0200 From: Jakub Jelinek To: Jason Merrill Cc: gcc-patches@gcc.gnu.org Subject: [PATCH] c++, v2: Improve handling of foreigner namespace attributes Message-ID: Reply-To: Jakub Jelinek References: <1a197a3f-f022-5293-323b-c53a9d43e946@redhat.com> MIME-Version: 1.0 In-Reply-To: <1a197a3f-f022-5293-323b-c53a9d43e946@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham 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 Thu, Oct 06, 2022 at 09:42:47AM -0400, Jason Merrill wrote: > > - tree t = lookup_attribute ("fallthrough", attr); > > + tree t = lookup_attribute (NULL, "fallthrough", attr); > > + if (t == NULL_TREE) > > + t = lookup_attribute ("gnu", "fallthrough", attr); > > Maybe lookup_attribute with a magic namespace argument that matches either > null or gnu? > > And similarly, a new is_attribute_namespace (name, t) function with the same > behavior, to be used here and in all the below hunks? So like this? 2022-10-05 Jakub Jelinek gcc/ * attribs.h (is_attribute_namespace_p): New inline function. (lookup_attribute): Document meaning of ATTR_NS equal to "". * attribs.cc (remove_attribute): Use is_attribute_namespace_p. (private_lookup_attribute): For ATTR_NS "" match either standard attribute or "gnu" namespace one. gcc/c-family/ * c-common.cc (attribute_fallthrough_p): Lookup fallthrough attribute only in gnu namespace or as standard attribute, treat fallthrough attributes in other namespaces like any other unknown attribute. gcc/cp/ * parser.cc (cp_parser_check_std_attribute): Only do checks if attribute is a standard attribute or in gnu namespace and only lookup other attributes in those namespaces. * cp-gimplify.cc (lookup_hotness_attribute): Adjust function comment. Only return true for standard attribute or gnu namespace attribute. (remove_hotness_attribute): Only remove hotness attributes when they are standard or in gnu namespace, implement it in a single loop rather than former 4 now 8 remove_attribute calls. gcc/testsuite/ * g++.dg/cpp1z/fallthrough2.C: New test. * g++.dg/cpp2a/attr-likely7.C: New test. --- gcc/attribs.h.jj 2022-10-05 16:15:29.834889059 +0200 +++ gcc/attribs.h 2022-10-06 17:59:56.918430468 +0200 @@ -188,6 +188,21 @@ is_attribute_p (const char *attr_name, c IDENTIFIER_POINTER (ident), IDENTIFIER_LENGTH (ident)); } +/* Given an identifier node IDENT or NULL and a string ATTR_NS, return true + if the identifier node is a valid attribute namespace for the string. + ATTR_NS "" stands for standard attribute (NULL IDENT) or "gnu" + namespace. */ + +static inline bool +is_attribute_namespace_p (const char *attr_ns, const_tree ident) +{ + if (attr_ns == NULL) + return ident == NULL_TREE; + if (attr_ns[0]) + return ident && is_attribute_p (attr_ns, ident); + return ident == NULL_TREE || is_attribute_p ("gnu", ident); +} + /* Given an attribute name ATTR_NAME and a list of attributes LIST, return a pointer to the attribute's list element if the attribute is part of the list, or NULL_TREE if not found. If the attribute @@ -217,7 +232,8 @@ lookup_attribute (const char *attr_name, } } -/* Similar to lookup_attribute, but also match the attribute namespace. */ +/* Similar to lookup_attribute, but also match the attribute namespace. + ATTR_NS "" stands for either standard attribute or "gnu" namespace. */ static inline tree lookup_attribute (const char *attr_ns, const char *attr_name, tree list) --- gcc/attribs.cc.jj 2022-10-04 23:13:10.289090796 +0200 +++ gcc/attribs.cc 2022-10-06 18:01:32.096146195 +0200 @@ -1645,7 +1645,8 @@ remove_attribute (const char *attr_name, return list; } -/* Similarly but also match namespace on the removed attributes. */ +/* Similarly but also match namespace on the removed attributes. + ATTR_NS "" stands for NULL or "gnu" namespace. */ tree remove_attribute (const char *attr_ns, const char *attr_name, tree list) @@ -1662,8 +1663,7 @@ remove_attribute (const char *attr_ns, c if (is_attribute_p (attr_name, attr)) { tree ns = get_attribute_namespace (l); - if ((ns == NULL_TREE && attr_ns == NULL) - || (ns && attr_ns && is_attribute_p (attr_ns, ns))) + if (is_attribute_namespace_p (attr_ns, ns)) { *p = TREE_CHAIN (l); continue; @@ -2088,14 +2088,20 @@ private_lookup_attribute (const char *at tree ns = get_attribute_namespace (list); if (ns == NULL_TREE) { - if (attr_ns == NULL) + if (attr_ns_len == 0) break; } else if (attr_ns) { ident_len = IDENTIFIER_LENGTH (ns); - if (cmp_attribs (attr_ns, attr_ns_len, IDENTIFIER_POINTER (ns), - ident_len)) + if (attr_ns_len == 0) + { + if (cmp_attribs ("gnu", strlen ("gnu"), + IDENTIFIER_POINTER (ns), ident_len)) + break; + } + else if (cmp_attribs (attr_ns, attr_ns_len, + IDENTIFIER_POINTER (ns), ident_len)) break; } } --- gcc/c-family/c-common.cc.jj 2022-10-06 17:43:47.880502941 +0200 +++ gcc/c-family/c-common.cc 2022-10-06 18:56:05.432888180 +0200 @@ -6008,12 +6008,12 @@ attribute_fallthrough_p (tree attr) { if (attr == error_mark_node) return false; - tree t = lookup_attribute ("fallthrough", attr); + tree t = lookup_attribute ("", "fallthrough", attr); if (t == NULL_TREE) return false; /* It is no longer true that "this attribute shall appear at most once in each attribute-list", but we still give a warning. */ - if (lookup_attribute ("fallthrough", TREE_CHAIN (t))) + if (lookup_attribute ("", "fallthrough", TREE_CHAIN (t))) warning (OPT_Wattributes, "attribute % specified multiple " "times"); /* No attribute-argument-clause shall be present. */ @@ -6024,9 +6024,11 @@ attribute_fallthrough_p (tree attr) for (t = attr; t != NULL_TREE; t = TREE_CHAIN (t)) { tree name = get_attribute_name (t); - if (!is_attribute_p ("fallthrough", name)) + tree ns = get_attribute_namespace (t); + if (!is_attribute_p ("fallthrough", name) + || !is_attribute_namespace_p ("", ns)) { - if (!c_dialect_cxx () && get_attribute_namespace (t) == NULL_TREE) + if (!c_dialect_cxx () && ns == NULL_TREE) /* The specifications of standard attributes in C mean this is a constraint violation. */ pedwarn (input_location, OPT_Wattributes, "%qE attribute ignored", --- gcc/cp/parser.cc.jj 2022-10-06 17:43:42.418576616 +0200 +++ gcc/cp/parser.cc 2022-10-06 18:57:14.019956324 +0200 @@ -29265,7 +29265,8 @@ cp_parser_check_std_attribute (location_ if (attributes) for (const auto &a : alist) if (is_attribute_p (a, get_attribute_name (attribute)) - && lookup_attribute (a, attributes)) + && is_attribute_namespace_p ("", get_attribute_namespace (attribute)) + && lookup_attribute ("", a, attributes)) { if (!from_macro_expansion_at (loc)) warning_at (loc, OPT_Wattributes, "attribute %qs specified " --- gcc/cp/cp-gimplify.cc.jj 2022-10-06 17:43:42.413576684 +0200 +++ gcc/cp/cp-gimplify.cc 2022-10-06 18:59:20.763234354 +0200 @@ -3027,7 +3027,7 @@ cp_fold (tree x) return x; } -/* Look up either "hot" or "cold" in attribute list LIST. */ +/* Look up "hot", "cold", "likely" or "unlikely" in attribute list LIST. */ tree lookup_hotness_attribute (tree list) @@ -3035,24 +3035,36 @@ lookup_hotness_attribute (tree list) for (; list; list = TREE_CHAIN (list)) { tree name = get_attribute_name (list); - if (is_attribute_p ("hot", name) - || is_attribute_p ("cold", name) - || is_attribute_p ("likely", name) - || is_attribute_p ("unlikely", name)) + if ((is_attribute_p ("hot", name) + || is_attribute_p ("cold", name) + || is_attribute_p ("likely", name) + || is_attribute_p ("unlikely", name)) + && is_attribute_namespace_p ("", get_attribute_namespace (list))) break; } return list; } -/* Remove both "hot" and "cold" attributes from LIST. */ +/* Remove "hot", "cold", "likely" and "unlikely" attributes from LIST. */ static tree remove_hotness_attribute (tree list) { - list = remove_attribute ("hot", list); - list = remove_attribute ("cold", list); - list = remove_attribute ("likely", list); - list = remove_attribute ("unlikely", list); + for (tree *p = &list; *p; ) + { + tree l = *p; + tree name = get_attribute_name (l); + if ((is_attribute_p ("hot", name) + || is_attribute_p ("cold", name) + || is_attribute_p ("likely", name) + || is_attribute_p ("unlikely", name)) + && is_attribute_namespace_p ("", get_attribute_namespace (l))) + { + *p = TREE_CHAIN (l); + continue; + } + p = &TREE_CHAIN (l); + } return list; } --- gcc/testsuite/g++.dg/cpp1z/fallthrough2.C.jj 2022-10-06 17:45:55.452782142 +0200 +++ gcc/testsuite/g++.dg/cpp1z/fallthrough2.C 2022-10-06 17:45:55.452782142 +0200 @@ -0,0 +1,24 @@ +// { dg-do compile { target c++17 } } +// { dg-options "-Wextra -Wall -Wpedantic" } + +int +foo (int i) +{ + switch (i) + { + case 2: + ++i; + [[fallthrough, whatever::fallthrough]]; // { dg-bogus "attribute 'fallthrough' specified multiple times" } + case 3: // { dg-warning "'fallthrough' attribute ignored" "" { target *-*-* } .-1 } + ++i; + [[fallthrough, whatever2::fallthrough(1, 2, 3)]]; // { dg-bogus "attribute 'fallthrough' specified multiple times" } + case 4: // { dg-warning "'fallthrough' attribute ignored" "" { target *-*-* } .-1 } + [[whatever3::fallthrough("abcd")]]; // { dg-warning "attributes at the beginning of statement are ignored" } + case 5: + [[whatever4::fallthrough]]; // { dg-bogus "attribute 'fallthrough' not preceding a case label or default label" } + ++i; // { dg-warning "attributes at the beginning of statement are ignored" "" { target *-*-* } .-1 } + default: + break; + } + return i; +} --- gcc/testsuite/g++.dg/cpp2a/attr-likely7.C.jj 2022-10-06 17:45:55.452782142 +0200 +++ gcc/testsuite/g++.dg/cpp2a/attr-likely7.C 2022-10-06 17:45:55.452782142 +0200 @@ -0,0 +1,38 @@ +// { dg-do compile { target c++20 } } +// { dg-additional-options -fdump-tree-gimple } +// { dg-final { scan-tree-dump-times "hot label" 5 "gimple" } } +// { dg-final { scan-tree-dump-times "cold label" 3 "gimple" } } + +bool b; + +template int f() +{ + if (b) + [[likely, whatever::unlikely ("abcd")]] return 0; // { dg-bogus "ignoring attribute 'unlikely' after earlier 'likely'" } + else // { dg-warning "attributes at the beginning of statement are ignored" "" { target *-*-* } .-1 } + [[unlikely, whatever2::hot]] flabel: return 1; // { dg-warning "'whatever2::hot' scoped attribute directive ignored" } + switch (b) + { + [[likely, whatever3::cold (1, 2, 3)]] case true: break; // { dg-warning "'whatever3::cold' scoped attribute directive ignored" } + }; + return 1; +} + +int main() +{ + if (b) + [[whatever4::unlikely (1), likely]] return 0; // { dg-bogus "ignoring attribute 'likely' after earlier 'unlikely'" } + else if (b) // { dg-warning "attributes at the beginning of statement are ignored" "" { target *-*-* } .-1 } + [[whatever5::hot, unlikely]] elabel: // { dg-warning "'whatever5::hot' scoped attribute directive ignored" } + return 1; + else + [[whatever6::cold, likely]] b = false; // { dg-bogus "ignoring attribute 'likely' after earlier 'cold'" } + // { dg-warning "attributes at the beginning of statement are ignored" "" { target *-*-* } .-1 } + f(); + + switch (b) + { + [[whatever7::unlikely (1), likely]] case true: break; // { dg-warning "'whatever7::unlikely' scoped attribute directive ignored" } + [[whatever8::unlikely, unlikely]] case false: break; // { dg-bogus "attribute 'unlikely' specified multiple times" } + }; // { dg-warning "'whatever8::unlikely' scoped attribute directive ignored" "" { target *-*-* } .-1 } +} Jakub