From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 87420 invoked by alias); 29 Sep 2016 16:10:37 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 87386 invoked by uid 89); 29 Sep 2016 16:10:33 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 29 Sep 2016 16:10:32 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C8381C05ACA9 for ; Thu, 29 Sep 2016 16:10:30 +0000 (UTC) Received: from redhat.com (ovpn-204-20.brq.redhat.com [10.40.204.20]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8TGARmg027514 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Thu, 29 Sep 2016 12:10:30 -0400 Date: Thu, 29 Sep 2016 16:26:00 -0000 From: Marek Polacek To: GCC Patches Subject: Fix missing -Wimplicit-fallthrough warning Message-ID: <20160929161027.GT3223@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.7.0 (2016-08-17) X-SW-Source: 2016-09/txt/msg02266.txt.bz2 Here, a missing -Wimplicit-fallthrough warning was caused by a misplaced FALLTHROUGH_LABEL_P check. As it is now, for FALLTHROUGH_LABEL_P we'd never gotten around to 1933 /* So that next warn_implicit_fallthrough_r will start looking for 1934 a new sequence starting with this label. */ 1935 gsi_prev (gsi_p); The fix is to move the check to should_warn_for_implicit_fallthrough. Bootstrapped/regtested on x86_64-linux and ppc64-linux, ok for trunk? 2016-09-29 Marek Polacek * gimplify.c (should_warn_for_implicit_fallthrough): Check for FALLTHROUGH_LABEL_P here... (warn_implicit_fallthrough_r): ...not here. * c-c++-common/Wimplicit-fallthrough-22.c: New test. diff --git gcc/gimplify.c gcc/gimplify.c index 66bb8be..e077a7e 100644 --- gcc/gimplify.c +++ gcc/gimplify.c @@ -1817,6 +1817,10 @@ should_warn_for_implicit_fallthrough (gimple_stmt_iterator *gsi_p, tree label) { gimple_stmt_iterator gsi = *gsi_p; + /* Don't warn if the label is marked with a "falls through" comment. */ + if (FALLTHROUGH_LABEL_P (label)) + return false; + /* Don't warn for a non-case label followed by a statement: case 0: foo (); @@ -1903,7 +1907,6 @@ warn_implicit_fallthrough_r (gimple_stmt_iterator *gsi_p, bool *handled_ops_p, if (gimple_code (next) == GIMPLE_LABEL && gimple_has_location (next) && (label = gimple_label_label (as_a (next))) - && !FALLTHROUGH_LABEL_P (label) && prev != NULL) { struct label_entry *l; diff --git gcc/testsuite/c-c++-common/Wimplicit-fallthrough-22.c gcc/testsuite/c-c++-common/Wimplicit-fallthrough-22.c index e69de29..7a81e47 100644 --- gcc/testsuite/c-c++-common/Wimplicit-fallthrough-22.c +++ gcc/testsuite/c-c++-common/Wimplicit-fallthrough-22.c @@ -0,0 +1,23 @@ +/* { dg-do compile } */ +/* { dg-options "-Wimplicit-fallthrough" } */ + +void bar (int); + +void +foo (int i) +{ + switch (i) + { + case 1: + bar (1); + /* FALLTHROUGH */ + case 2: + bar (2); /* { dg-warning "statement may fall through" } */ + case 3: + bar (3); /* { dg-warning "statement may fall through" } */ + case 4: + bar (4); + default: + break; + } +} Marek