From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa3.mentor.iphmx.com (esa3.mentor.iphmx.com [68.232.137.180]) by sourceware.org (Postfix) with ESMTPS id 0B9E0385771B for ; Mon, 15 May 2023 23:18:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 0B9E0385771B Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mentor.com X-IronPort-AV: E=Sophos;i="5.99,277,1677571200"; d="scan'208";a="5444494" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa3.mentor.iphmx.com with ESMTP; 15 May 2023 15:18:38 -0800 IronPort-SDR: dOb9ll6H6GhTojK7adbm3Z5J52eLd6LPGGBlIDZLAN9d+FtK8FfINefmG5fGDXsGcwJHYDpCVJ GKe0HmpX8NEPfcetKRQS/4zwvZw01eI61di1lElXUNQHzDTSsJMhy4oQKs27jU5XsLn7Y6lvdy ZcXcqFHcgwZEG8xuzi2YjlklzkDo5Mlzt8iIOg2srShH7bmyQ3qxqx0ZJhH4krvbxnF0FvQAIA E+jaYNmDLAbEpZu4lMPtHLj0C2NzTnEvLVh2UhNzLSdmqWm2wrvGtCjYokEVo6/vjaZQC6WPYS kjM= Date: Mon, 15 May 2023 23:18:33 +0000 From: Joseph Myers To: Subject: [committed] c: Ignore _Atomic on function return type for C2x Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: svr-ies-mbx-13.mgc.mentorg.com (139.181.222.13) To svr-ies-mbx-10.mgc.mentorg.com (139.181.222.10) X-Spam-Status: No, score=-3112.8 required=5.0 tests=BAYES_00,GIT_PATCH_0,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,SPF_HELO_PASS,SPF_PASS,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 List-Id: For C2x it was decided that _Atomic would be completely ignored on function return types (just as was done for qualifiers in C11 DR#423), to eliminate the potential for an rvalue returned by a function having _Atomic-qualified type when an rvalue resulting from lvalue-to-rvalue conversion could not have such a type. Implement this for GCC. Bootstrapped with no regressions for x86_64-pc-linux-gnu. gcc/c/ * c-decl.cc (grokdeclarator): Ignore _Atomic on function return type for C2x. gcc/testsuite/ * gcc.dg/qual-return-9.c, gcc.dg/qual-return-10.c: New tests. diff --git a/gcc/c/c-decl.cc b/gcc/c/c-decl.cc index 1b53f2d0785..90d7cd27cd5 100644 --- a/gcc/c/c-decl.cc +++ b/gcc/c/c-decl.cc @@ -7412,9 +7412,12 @@ grokdeclarator (const struct c_declarator *declarator, them for noreturn functions. The resolution of C11 DR#423 means qualifiers (other than _Atomic) are actually removed from the return type when - determining the function type. */ + determining the function type. For C2X, _Atomic is + removed as well. */ int quals_used = type_quals; - if (flag_isoc11) + if (flag_isoc2x) + quals_used = 0; + else if (flag_isoc11) quals_used &= TYPE_QUAL_ATOMIC; if (quals_used && VOID_TYPE_P (type) && really_funcdef) pedwarn (specs_loc, 0, diff --git a/gcc/testsuite/gcc.dg/qual-return-10.c b/gcc/testsuite/gcc.dg/qual-return-10.c new file mode 100644 index 00000000000..c7dd6adc4c6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/qual-return-10.c @@ -0,0 +1,12 @@ +/* Test qualifiers on function return types in C2X (C2X version of + qual-return-6.c): those qualifiers are now ignored for all purposes, + including _Atomic, but should still get warnings. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -Wignored-qualifiers" } */ + +const int f1 (void); /* { dg-warning "qualifiers ignored" } */ +volatile int f2 (void) { return 0; } /* { dg-warning "qualifiers ignored" } */ +const volatile void f3 (void) { } /* { dg-warning "qualifiers ignored" } */ +const void f4 (void); /* { dg-warning "qualifiers ignored" } */ +_Atomic int f5 (void); /* { dg-warning "qualifiers ignored" } */ +_Atomic int f6 (void) { return 0; } /* { dg-warning "qualifiers ignored" } */ diff --git a/gcc/testsuite/gcc.dg/qual-return-9.c b/gcc/testsuite/gcc.dg/qual-return-9.c new file mode 100644 index 00000000000..7762782edf0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/qual-return-9.c @@ -0,0 +1,32 @@ +/* Test qualifiers on function return types in C2X (C2X version of + qual-return-5.c): those qualifiers are now ignored for all purposes, + including _Atomic. */ +/* { dg-do compile } */ +/* { dg-options "-std=c2x -pedantic-errors" } */ + +int f1 (void); +const int f1 (void); +volatile int f1 (void) { return 0; } + +int *restrict f2 (void) { return 0; } +int *f2 (void); + +const volatile long f3 (void); +long f3 (void); + +const volatile void f4 (void) { } +void f4 (void); + +_Atomic int f5 (void); +int f5 (void); + +int f6 (void); +_Atomic int f6 (void) { return 0; } + +/* The standard seems unclear regarding the case where restrict is + applied to a function return type that may not be + restrict-qualified; assume here that it is disallowed. */ +restrict int f7 (void); /* { dg-error "restrict" } */ + +typedef void FT (void); +FT *restrict f8 (void); /* { dg-error "restrict" } */ -- Joseph S. Myers joseph@codesourcery.com