From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755434AbcCNS4E (ORCPT ); Mon, 14 Mar 2016 14:56:04 -0400 Received: from smtprelay0092.hostedemail.com ([216.40.44.92]:37486 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752390AbcCNSz6 (ORCPT ); Mon, 14 Mar 2016 14:55:58 -0400 X-Session-Marker: 6A6F6540706572636865732E636F6D X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,joe@perches.com,:::::::::,RULES_HIT:41:355:379:541:968:982:988:989:1260:1277:1311:1313:1314:1345:1373:1437:1515:1516:1518:1534:1541:1593:1594:1711:1730:1747:1777:1792:2393:2559:2562:2828:3138:3139:3140:3141:3142:3352:3865:3866:3867:3868:3870:3872:3874:5007:6119:6261:7903:8660:10004:10400:10450:10455:10848:11026:11658:11914:12043:12295:12438:12517:12519:13069:13148:13230:13311:13357:13439:13894:14659:19904:19999:21080:30054,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:1,LUA_SUMMARY:none X-HE-Tag: ghost39_61c33e6bd564e X-Filterd-Recvd-Size: 1944 Message-ID: <1457981670.11972.114.camel@perches.com> Subject: coccinelle: generalized removal of unnecessary pointer casts? From: Joe Perches To: Julia Lawall Cc: cocci , LKML , Dan Carpenter , kernel-janitors Date: Mon, 14 Mar 2016 11:54:30 -0700 Content-Type: text/plain; charset="ISO-8859-1" X-Mailer: Evolution 3.18.5.1-1ubuntu1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I wrote a little cocci script to remove unnecessary casts for memset and memcpy (below) and tested it on linux kernel's drivers/staging/ directory. For instance, when dst and src are already pointers: - memcpy((u8 *)dst, (u8 *)src, r8712_get_wlan_bssid_ex_sz(src)); + memcpy(dst, src, r8712_get_wlan_bssid_ex_sz(src)); It works ok, (it doesn't remove unnecessary parentheses around the pointers) but it makes me wonder if there's a generalized spatch mechanism to remove casts when an arbitrary function takes a void * in any argument position and a call to that function uses a cast of a pointer to any pointer type for that argument. $ cat remove_mem_casts.cocci  @@ type t; t *p; type v; expression e1; expression e2; @@ - memset((v*)p, e1, e2) + memset(p, e1, e2) @@ type t; t *p; type v; expression e1; expression e2; @@ - memcpy((v*)p, e1, e2) + memcpy(p, e1, e2) @@ type t; t *p; type v; expression e1; expression e2; @@ - memcpy(e1, (v*)p, e2) + memcpy(e1, p, e2) @@ type t1; type t2; t1 *p1; t2 *p2; type v1; type v2; expression e1; @@ - memcpy((v1*)p1, (v2*)p2, e1) + memcpy(p1, p2, e1)