From patchwork Mon Aug 1 18:49:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Tom Honermann X-Patchwork-Id: 56473 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 7E324385801E for ; Mon, 1 Aug 2022 18:49:36 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7E324385801E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1659379776; bh=iRhyc1CjOp7J4w+1rfXQt0RMal08vr/S8tK7q4juOYs=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=i1GV1xbAxFgNYvKOm0UaKVGe6ScehUI2d+f8tAHNrf1H+hdcAXK/j80ZmB931Ttu7 UkpN4DylbXPH0ywokKSlrZ/MIRQcoHlI+n/t1FeTaXi4ZhuzCJNBAMpU+RuH4ep2QJ zk2sbe5tyXV1pi8ZmMveZTlM4D+3vEDcOhgaD5qY= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from smtp127.iad3b.emailsrvr.com (smtp127.iad3b.emailsrvr.com [146.20.161.127]) by sourceware.org (Postfix) with ESMTPS id 6046C385842E for ; Mon, 1 Aug 2022 18:49:07 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6046C385842E X-Auth-ID: tom@honermann.net Received: by smtp8.relay.iad3b.emailsrvr.com (Authenticated sender: tom-AT-honermann.net) with ESMTPSA id F2E524015F; Mon, 1 Aug 2022 14:49:05 -0400 (EDT) To: gcc-patches@gcc.gnu.org Subject: [PATCH 1/1 v2] c++/106423: Fix pragma suppression of -Wc++20-compat diagnostics. Date: Mon, 1 Aug 2022 14:49:00 -0400 Message-Id: <20220801184900.1326396-1-tom@honermann.net> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220724043902.1777378-2-tom@honermann.net> References: <20220724043902.1777378-2-tom@honermann.net> MIME-Version: 1.0 X-Classification-ID: e7526e11-0ef7-462b-8285-687f985a657e-1-1 X-Spam-Status: No, score=-10.6 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, 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 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-Patchwork-Original-From: Tom Honermann via Gcc-patches From: Tom Honermann Reply-To: Tom Honermann Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Gcc's '#pragma GCC diagnostic' directives are processed in "early mode" (see handle_pragma_diagnostic_early) for the C++ frontend and, as such, require that the target diagnostic option be enabled for the preprocessor (see c_option_is_from_cpp_diagnostics). This change modifies the -Wc++20-compat option definition to register it as a preprocessor option so that its associated diagnostics can be suppressed. The changes also implicitly disable the option in C++20 and later modes. These changes are consistent with the definition of the -Wc++11-compat option. This support is motivated by the need to suppress the following diagnostic otherwise issued in C++17 and earlier modes due to the char8_t typedef present in the uchar.h header file in glibc 2.36. warning: identifier ‘char8_t’ is a keyword in C++20 [-Wc++20-compat] Tests are added to validate suppression of both -Wc++11-compat and -Wc++20-compat related diagnostics (fixes were only needed for the C++20 case). Fixes https://gcc.gnu.org/PR106423. gcc/c-family/ChangeLog: * c-opts.cc (c_common_post_options): Disable -Wc++20-compat diagnostics in C++20 and later. * c.opt (Wc++20-compat): Enable hooks for the preprocessor. gcc/testsuite/ChangeLog: * g++.dg/cpp0x/keywords2.C: New test. * g++.dg/cpp2a/keywords2.C: New test. libcpp/ChangeLog: * include/cpplib.h (cpp_warning_reason): Add CPP_W_CXX20_COMPAT. * init.cc (cpp_create_reader): Add cpp_warn_cxx20_compat. --- gcc/c-family/c-opts.cc | 7 +++++++ gcc/c-family/c.opt | 2 +- gcc/cp/parser.cc | 5 ++++- gcc/testsuite/g++.dg/cpp0x/keywords2.C | 16 ++++++++++++++++ gcc/testsuite/g++.dg/cpp2a/keywords2.C | 13 +++++++++++++ libcpp/include/cpplib.h | 4 ++++ libcpp/init.cc | 1 + 7 files changed, 46 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp0x/keywords2.C create mode 100644 gcc/testsuite/g++.dg/cpp2a/keywords2.C diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc index b9f01a65ed7..1ea37ba9742 100644 --- a/gcc/c-family/c-opts.cc +++ b/gcc/c-family/c-opts.cc @@ -1046,6 +1046,13 @@ c_common_post_options (const char **pfilename) else if (warn_narrowing == -1) warn_narrowing = 0; + if (cxx_dialect >= cxx20) + { + /* Don't warn about C++20 compatibility changes in C++20 or later. */ + warn_cxx20_compat = 0; + cpp_opts->cpp_warn_cxx20_compat = 0; + } + /* C++17 has stricter evaluation order requirements; let's use some of them for earlier C++ as well, so chaining works as expected. */ if (c_dialect_cxx () diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt index 44e1a60ce24..dfdebd596ef 100644 --- a/gcc/c-family/c.opt +++ b/gcc/c-family/c.opt @@ -455,7 +455,7 @@ Wc++2a-compat C++ ObjC++ Warning Alias(Wc++20-compat) Undocumented Wc++20-compat -C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ ObjC++,Wall) +C++ ObjC++ Var(warn_cxx20_compat) Warning LangEnabledBy(C++ ObjC++,Wall) Init(0) CPP(cpp_warn_cxx20_compat) CppReason(CPP_W_CXX20_COMPAT) Warn about C++ constructs whose meaning differs between ISO C++ 2017 and ISO C++ 2020. Wc++11-extensions diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc index 4f67441eeb1..c3584446827 100644 --- a/gcc/cp/parser.cc +++ b/gcc/cp/parser.cc @@ -924,7 +924,10 @@ cp_lexer_saving_tokens (const cp_lexer* lexer) /* Store the next token from the preprocessor in *TOKEN. Return true if we reach EOF. If LEXER is NULL, assume we are handling an initial #pragma pch_preprocess, and thus want the lexer to return - processed strings. */ + processed strings. + + Diagnostics issued from this function must have their controlling option (if + any) in c.opt annotated as a libcpp option via the CppReason property. */ static void cp_lexer_get_preprocessor_token (unsigned flags, cp_token *token) diff --git a/gcc/testsuite/g++.dg/cpp0x/keywords2.C b/gcc/testsuite/g++.dg/cpp0x/keywords2.C new file mode 100644 index 00000000000..d67d01e31ed --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/keywords2.C @@ -0,0 +1,16 @@ +// { dg-do compile { target c++98_only } } +// { dg-options "-Wc++11-compat" } + +// Validate suppression of -Wc++11-compat diagnostics. +#pragma GCC diagnostic ignored "-Wc++11-compat" +int alignof; +int alignas; +int constexpr; +int decltype; +int noexcept; +int nullptr; +int static_assert; +int thread_local; +int _Alignas; +int _Alignof; +int _Thread_local; diff --git a/gcc/testsuite/g++.dg/cpp2a/keywords2.C b/gcc/testsuite/g++.dg/cpp2a/keywords2.C new file mode 100644 index 00000000000..8714a7b26b7 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/keywords2.C @@ -0,0 +1,13 @@ +// { dg-do compile { target c++17_down } } +// { dg-options "-Wc++20-compat" } + +// Validate suppression of -Wc++20-compat diagnostics. +#pragma GCC diagnostic ignored "-Wc++20-compat" +int constinit; +int consteval; +int requires; +int concept; +int co_await; +int co_yield; +int co_return; +int char8_t; diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h index 3eba6f74b57..9d90c18e4f2 100644 --- a/libcpp/include/cpplib.h +++ b/libcpp/include/cpplib.h @@ -547,6 +547,9 @@ struct cpp_options /* True if warn about differences between C++98 and C++11. */ bool cpp_warn_cxx11_compat; + /* True if warn about differences between C++17 and C++20. */ + bool cpp_warn_cxx20_compat; + /* Nonzero if bidirectional control characters checking is on. See enum cpp_bidirectional_level. */ unsigned char cpp_warn_bidirectional; @@ -655,6 +658,7 @@ enum cpp_warning_reason { CPP_W_C90_C99_COMPAT, CPP_W_C11_C2X_COMPAT, CPP_W_CXX11_COMPAT, + CPP_W_CXX20_COMPAT, CPP_W_EXPANSION_TO_DEFINED, CPP_W_BIDIRECTIONAL }; diff --git a/libcpp/init.cc b/libcpp/init.cc index f4ab83d2145..cca3c1dc1e7 100644 --- a/libcpp/init.cc +++ b/libcpp/init.cc @@ -202,6 +202,7 @@ cpp_create_reader (enum c_lang lang, cpp_hash_table *table, CPP_OPTION (pfile, cpp_warn_c90_c99_compat) = -1; CPP_OPTION (pfile, cpp_warn_c11_c2x_compat) = -1; CPP_OPTION (pfile, cpp_warn_cxx11_compat) = 0; + CPP_OPTION (pfile, cpp_warn_cxx20_compat) = 0; CPP_OPTION (pfile, cpp_warn_deprecated) = 1; CPP_OPTION (pfile, cpp_warn_long_long) = 0; CPP_OPTION (pfile, dollars_in_ident) = 1;