From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by sourceware.org (Postfix) with ESMTPS id 6F6E33858D28 for ; Tue, 1 Aug 2023 13:27:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 6F6E33858D28 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=oracle.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=oracle.com Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 371BB90P028165; Tue, 1 Aug 2023 13:27:25 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : references : in-reply-to : content-type : content-id : content-transfer-encoding : mime-version; s=corp-2023-03-30; bh=CNCDoa7iaH7Zaoxj4f21OC53XzRwviHNmpmx/9mlAQs=; b=mwj1V4b4/3H00PaBqUm1s3NvLPlG9Nmv/5ANaVUk3PAbqKJHxHCAg9SLEJNKGuZ8iLKl 59fzAiWUQqJFw8qF2Y8Ct+0H4D8IbxPe+JFUISXgdkgeloPWLGdCNhCW7todYAj0mTqC AbN8p8ER0mL4i1qrE9Wq09QdtIU7LfQQAMXDF+iTHXO5x4cwaEfiD++AXgCovmw3abs2 +Jp5eNrGMOuF/iW4v9cyUNZQdP+lWZNQyg0xhX5KyG3FM+ShjCN4gGIeSj4xyTXwq3yJ Grpbs/682iDdmGw3ECpI74icIK4wxaVbZ7lH9B9U55E3ll5qB0CZyGDRVj0DG79Yrrc4 Fw== Received: from phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta03.appoci.oracle.com [138.1.37.129]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3s4sj3vx3m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Aug 2023 13:27:24 +0000 Received: from pps.filterd (phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 371C4jfW033451; Tue, 1 Aug 2023 13:27:23 GMT Received: from nam12-bn8-obe.outbound.protection.outlook.com (mail-bn8nam12lp2176.outbound.protection.outlook.com [104.47.55.176]) by phxpaimrmta03.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3s4s76krf0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Aug 2023 13:27:23 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=kMvQqLo/m3QTCtrWfxcLPPosjx9LAt4xwTxF8H1Azy2dA8K0wMiz2iQMH+gKPmsAX6L9gEMGYxatr74TrKEVgK3EfB8+QxC6eTzL0q27NDegsky1mFPQx9O+3sXIyAjzUf4P2n7oE6Gj5SZjyMp6kLejDHW656Mrs+EKQ8pTZVVL9IC38qe6AYTOiZ5HxmqARqBNQVNeXFYEqNnFMQ6sFWE66q5NzdKMu33JhsXLrBADTNh0Snt3ZPMmzmSM0tGBfhZ4esqIWN/tw1+mAE1XUUmsONm22exNsofYv+Q23pprXwf39eqNGE7asEECNLnqN+fleBs6q+QdLLfaYQA2Eg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=CNCDoa7iaH7Zaoxj4f21OC53XzRwviHNmpmx/9mlAQs=; b=QJQWONyl70LVolQ8eM2MUzOggklLB6t0Ud/LVnuPW4qRShXFj0kc5HP9lbv0QlVS+rrJeUSVUqqQTVQBYWk2j44Nm+qMMCLSLmKh3UezQDOssMZqsS/xz6DhlVNyoFMOXMR56QBVy3wE680mWpCIWJOji6QaeDxI7+HatLvCeAC4FgXx/Hf6/hy1EOEtYCoQulc2MS5Cb5nbU//K/xfOEqKoYFqBhPwDxEziIIV91Thd32Y03BMEcqJoOrPOsdXLkV2ZMGvYw68kVpGb5k+SX7eSefORE7IU10t8G6WGMm4rHMDtr9qMpKPNjW2LM9OqzJCZqSdq+8Hu4a/7DDqggw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=CNCDoa7iaH7Zaoxj4f21OC53XzRwviHNmpmx/9mlAQs=; b=YN7yVbQ/XdlbADOx9dXYecxUEJByDiC8PPx0faK3oAvCg17qRc/GRNUWCt8i1BLWG5TWreB+g86cTnI5DcjD9BAkJm1KL7h/d3F9FSDzAT9ciLUONFB//B6E0t3W2fQp6qUNx+gaShuT5IGDt39UVRl387Emskn15beJiaRIwEA= Received: from CH2PR10MB4344.namprd10.prod.outlook.com (2603:10b6:610:af::19) by PH0PR10MB7062.namprd10.prod.outlook.com (2603:10b6:510:283::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6631.44; Tue, 1 Aug 2023 13:27:20 +0000 Received: from CH2PR10MB4344.namprd10.prod.outlook.com ([fe80::5afd:d02a:38ef:94ba]) by CH2PR10MB4344.namprd10.prod.outlook.com ([fe80::5afd:d02a:38ef:94ba%7]) with mapi id 15.20.6631.043; Tue, 1 Aug 2023 13:27:20 +0000 From: Qing Zhao To: Martin Uecker CC: Prathamesh Kulkarni , "gcc-patches@gcc.gnu.org" , Joseph Myers Subject: Re: [C PATCH]: Add Walloc-type to warn about insufficient size in allocations Thread-Topic: [C PATCH]: Add Walloc-type to warn about insufficient size in allocations Thread-Index: AQHZu8Wx4KRUrk7iNUCCknDM1JLu+K/UZ1oAgAC6+oCAAF3rgA== Date: Tue, 1 Aug 2023 13:27:20 +0000 Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-mailer: Apple Mail (2.3696.120.41.1.3) x-ms-publictraffictype: Email x-ms-traffictypediagnostic: CH2PR10MB4344:EE_|PH0PR10MB7062:EE_ x-ms-office365-filtering-correlation-id: fdce6b97-746d-4b60-1818-08db929308aa x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: 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 x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH2PR10MB4344.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(346002)(39860400002)(376002)(396003)(136003)(366004)(451199021)(66476007)(41300700001)(5660300002)(8936002)(91956017)(6916009)(66946007)(8676002)(76116006)(44832011)(4326008)(478600001)(54906003)(316002)(2906002)(84970400001)(66446008)(64756008)(66556008)(6486002)(6512007)(71200400001)(38100700002)(53546011)(6506007)(36756003)(83380400001)(2616005)(33656002)(122000001)(38070700005)(186003)(86362001)(45980500001);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?clNiyTkzrt2mjrf4Rl/RsmXmBGTANYd0ZGSwNxOr9XF5rDRU/oFEA4ar5+Bi?= =?us-ascii?Q?+j7BZOKHm3q1CHt7fz0uPAs20ix7NMzo+yGLfdyS997D/5U/5ISJjey4e1WV?= =?us-ascii?Q?60dPHGHO+YX04j4l2RJCjqffx097um5jrrWrN91V3osMyD4w1iZri7iIITwC?= =?us-ascii?Q?T6XaxC5YHktnvzm0hNa4QX7ELvJSBExAxnTXQdiKanXeuHAH4r2cxhdachHo?= =?us-ascii?Q?Y0lznHaxitsXWkVK9DOAGMl2ykkjD6YjM7YDxdvEayGsgOX60abzVcGKtLyy?= =?us-ascii?Q?FSbSQZjw9+L7z3WgzLB9FucOGl1G0J2LWLwhGtn/9AvxBC+WRrNgQSfjpDW9?= =?us-ascii?Q?VL46leeEeqeTXyTWfM20WbhDNbp5VxkBI8gZvdRdkaKwaVI2nocaVhcBYnyR?= =?us-ascii?Q?unlIsh53yaSuEsC1Qtz8E1z1QCsthoEwc+kCzt4gvnYbsk0tRSHi6oIjQiR2?= =?us-ascii?Q?Br2ee5+gQ9S3GJvku/DPIJNCqXyG+lqGuLqKO7+CZVoYRAnRC2wQbxML3Iyp?= =?us-ascii?Q?CtcHJjdHZGW82qdAbd0sd01BnfZ+EBDWtcsIkbwcYhlNUvkGm6H9Y7Fj9x0e?= =?us-ascii?Q?oXpPESXYcN+n3p5uILb1P6WMVBeByzaFbsGcX8x7Dob9LefqDNZYAy1mwI8n?= =?us-ascii?Q?aY194wr3kMSYSuDRCsjk+Y8LccvOMLtEnQGZT5WmbmNv3mkWhi+9WcPBNzy0?= =?us-ascii?Q?SRslHwqF8pdQli4T9G+EcUshEXTIMHO2xUekFWB32MD6BZePKYpI5HsPQfj+?= =?us-ascii?Q?TZmHjEN2L243fbMB83dm57NLRod/NH64wYesAjS0xwCIdE91yu/s70glDOmB?= =?us-ascii?Q?dZXNyaUmsUYif5y2u5epVNMZ8m6dbHWyKvVQsJROSljlIki5tyO0sZof6GDR?= =?us-ascii?Q?fvuHue23QxpflcCJwel/7jluCJUUvZ6bBnCQVdBEzvaEra8Od9PpikLrAkPf?= =?us-ascii?Q?0vtyHQ/gMjcYQVa8aa829QtUBRry6bLT3LYTX6jZyD/6d/NIstG8NPrYkUr3?= =?us-ascii?Q?xIE1fZL6QWqbd2GrLX/1TxHnou2C9FI+j5PqmYtLy5z3L+sx3UOLkdI84EEH?= =?us-ascii?Q?1rInWdhdU1JllK1xhBsLps7C1ee4WOhIbVD9ny0VcTGHW0+jHXioO/Jchjty?= =?us-ascii?Q?If0Diyxb1T3RshzdUY5yg5na6HdGYiJt/Cq6DxElVQ/jqcilpvs3uMuUXjBP?= =?us-ascii?Q?ZU0qGBgFPU/qVju7Oab2z4ubAOD4Rr2CkHFjQ/DDYsE7JU4i3RmMadwEU5VU?= =?us-ascii?Q?9fPEYOqFCViQUIeqvcsm2F82wUSr/tW4IKRWzfsykuuebxFV11Jb1ZauCwCz?= =?us-ascii?Q?4RpXwKR1oFYok8BlR4rg7W6dMJlVAfSCjbqs26tTjZ3//CuP0ieQfCMEQi2e?= =?us-ascii?Q?wSCPPS50FayLMS3iOZ4FuGWvowMfJpCQtREfFdu6/qq91ueQVekExEMDeu/4?= =?us-ascii?Q?tXGUoxgxuOx2CbN+f5cDoqVqf3NPaUyUGtDd3CZM1zwwwYXgfhFLgl+RZU8y?= =?us-ascii?Q?EOq/pBLnZ6rb/osojeZ289IsvFUtON/wma6TkYOjaxd/CbxGVJvRhrgEXKdj?= =?us-ascii?Q?LgS3u4QRSzZHwi2kRlBmWV0Fm69J7wdeTXdj2fn4wYSRTQXlo8JVwrQLwlhU?= =?us-ascii?Q?jAJXuz+13O3LhjrWJJlZwHg=3D?= Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: H3suYDgnKHPuZsIv+kHxHKNLr1lXZZcnJqxjEoMetB+8VxRY1mEr2BW7JdRPjDHL5TyFbE4dlSMvg2/nLcmUyXzxB7xFWJmAVQLT4mSsKZEYymhNApBMGhWwwdSv8r0eq52LcP9yMc64vaGgPPFyo+KReB13e0qt3ZajQIXI3jOK6NyFd8Vn4LMXtxnAT3+egfHBuzTy/li0FBKD9DaIaPgvi2VpZ2Ta5PLuAu5mI8ORFk4RHnAE9hr8LPDG4Fhv7k0cKNXOB2SYx1cOxLqGUmxH94/XRPG0DqI9ruZ9y4pnAiYU1rx2ymCqcT4z49N5zeT08bTVZvDT/WpEIbq/g+00Ar8KyrxmmFdy/ja9meTtTc/14fs+Kuxbzun3dLr7V2CQHJXVovX8nEs6u5EXTAI57u2Vh1HxHsUhtmWVySy0LAs7+BjfRmU+R/FbowfH33jwBi7+at4hLoe3YJafgt2KTfmNm2M3yT0zVTWpH4U7z3OPwjyB2cieSCEAAfORWZeKbBP2bxwTMfYZ7vI4xybB0MJe3R4JNtfXiCizLYp3a04MGvoLfVzvlr8tgKVXRKTjiM9MrOekllJqVH9Id/AWLWb0WJbskeILvXU8D0qxP5dkoz/RloGBb/0qMfTIe2w8Pbs5IzLlAu4XBjPB0lFoj7lF8IxNDDMxn5/0p0tvjEhKux3XgotFuAKMAnCzw0JBypZq3uA9XuSYhv079ow44WgSMAfi6ly1C2e83XMoTFxdZMcSbv0alEH2tPkzXLSH2lfD82Kho+nWtqBzxeiL8p9ncSkmqHECnq5zBRoQVVpXG59qcNYI1Kq2cVaRTg7KvdwEg3QYLL77VQ/gPcyHb8kab3hTnR+OhmYye94= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: CH2PR10MB4344.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: fdce6b97-746d-4b60-1818-08db929308aa X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Aug 2023 13:27:20.5931 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: vprAte2S5i8NjY2a3cQExbVj49MwOmdCk8UKbv4Y0sS9peH/WYakkG2s5UoLz8Flcq3ElmJUHtaETIiNiRRw+Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH0PR10MB7062 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-08-01_09,2023-08-01_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 malwarescore=0 adultscore=0 bulkscore=0 suspectscore=0 spamscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2306200000 definitions=main-2308010121 X-Proofpoint-GUID: cd8Aa_6zqSV0idcYgCTrv7abfMp1LDwN X-Proofpoint-ORIG-GUID: cd8Aa_6zqSV0idcYgCTrv7abfMp1LDwN X-Spam-Status: No, score=-11.4 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_LOW,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,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: > On Aug 1, 2023, at 3:51 AM, Martin Uecker via Gcc-patches wrote: >=20 > Am Dienstag, dem 01.08.2023 um 02:11 +0530 schrieb Prathamesh Kulkarni: >> On Fri, 21 Jul 2023 at 16:52, Martin Uecker via Gcc-patches >> wrote: >>>=20 >>>=20 >>>=20 >>> This patch adds a warning for allocations with insufficient size >>> based on the "alloc_size" attribute and the type of the pointer >>> the result is assigned to. While it is theoretically legal to >>> assign to the wrong pointer type and cast it to the right type >>> later, this almost always indicates an error. Since this catches >>> common mistakes and is simple to diagnose, it is suggested to >>> add this warning. >>>=20 >>>=20 >>> Bootstrapped and regression tested on x86. >>>=20 >>>=20 >>> Martin >>>=20 >>>=20 >>>=20 >>> Add option Walloc-type that warns about allocations that have >>> insufficient storage for the target type of the pointer the >>> storage is assigned to. >>>=20 >>> gcc: >>> * doc/invoke.texi: Document -Wstrict-flex-arrays option. >>>=20 >>> gcc/c-family: >>>=20 >>> * c.opt (Walloc-type): New option. >>>=20 >>> gcc/c: >>> * c-typeck.cc (convert_for_assignment): Add Walloc-type warning. >>>=20 >>> gcc/testsuite: >>>=20 >>> * gcc.dg/Walloc-type-1.c: New test. >>>=20 >>>=20 >>> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt >>> index 4abdc8d0e77..8b9d148582b 100644 >>> --- a/gcc/c-family/c.opt >>> +++ b/gcc/c-family/c.opt >>> @@ -319,6 +319,10 @@ Walloca >>> C ObjC C++ ObjC++ Var(warn_alloca) Warning >>> Warn on any use of alloca. >>>=20 >>> +Walloc-type >>> +C ObjC Var(warn_alloc_type) Warning >>> +Warn when allocating insufficient storage for the target type of the >>> assigned pointer. >>> + >>> Walloc-size-larger-than=3D >>> C ObjC C++ LTO ObjC++ Var(warn_alloc_size_limit) Joined Host_Wide_Int >>> ByteSize Warning Init(HOST_WIDE_INT_MAX) >>> -Walloc-size-larger-than=3D Warn for calls to allocation >>> functions that >>> diff --git a/gcc/c/c-typeck.cc b/gcc/c/c-typeck.cc >>> index 7cf411155c6..2e392f9c952 100644 >>> --- a/gcc/c/c-typeck.cc >>> +++ b/gcc/c/c-typeck.cc >>> @@ -7343,6 +7343,32 @@ convert_for_assignment (location_t location, >>> location_t expr_loc, tree type, >>> "request for implicit conversion " >>> "from %qT to %qT not permitted in C++", rhstype, >>> type); >>>=20 >>> + /* Warn of new allocations are not big enough for the target >>> type. */ >>> + tree fndecl; >>> + if (warn_alloc_type >>> + && TREE_CODE (rhs) =3D=3D CALL_EXPR >>> + && (fndecl =3D get_callee_fndecl (rhs)) !=3D NULL_TREE >>> + && DECL_IS_MALLOC (fndecl)) >>> + { >>> + tree fntype =3D TREE_TYPE (fndecl); >>> + tree fntypeattrs =3D TYPE_ATTRIBUTES (fntype); >>> + tree alloc_size =3D lookup_attribute ("alloc_size", >>> fntypeattrs); >>> + if (alloc_size) >>> + { >>> + tree args =3D TREE_VALUE (alloc_size); >>> + int idx =3D TREE_INT_CST_LOW (TREE_VALUE (args)) - 1; >>> + /* For calloc only use the second argument. */ >>> + if (TREE_CHAIN (args)) >>> + idx =3D TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN >>> (args))) - 1; >>> + tree arg =3D CALL_EXPR_ARG (rhs, idx); >>> + if (TREE_CODE (arg) =3D=3D INTEGER_CST >>> + && tree_int_cst_lt (arg, TYPE_SIZE_UNIT (ttl))) >> Hi Martin, >> Just wondering if it'd be a good idea perhaps to warn if alloc size is >> not a multiple of TYPE_SIZE_UNIT instead of just less-than ? >> So it can catch cases like: >> int *p =3D malloc (sizeof (int) + 2); // probably intended malloc >> (sizeof (int) * 2) >>=20 >> FWIW, this is caught using -fanalyzer: >> f.c: In function 'f': >> f.c:3:12: warning: allocated buffer size is not a multiple of the >> pointee's size [CWE-131] [-Wanalyzer-allocation-size] >> 3 | int *p =3D __builtin_malloc (sizeof(int) + 2); >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>=20 >> Thanks, >> Prathamesh >=20 > Yes, this is probably a good idea. It might need special > logic for flexible array members then... Why special logic for FAM on such warning? (Not a multiple of TYPE_SIZE_UNI= T for the element). >=20 >=20 > Martin >=20 >=20 >>> + warning_at (location, OPT_Walloc_type, "allocation of >>> " >>> + "insufficient size %qE for type %qT with >>> " >>> + "size %qE", arg, ttl, TYPE_SIZE_UNIT >>> (ttl)); >>> + } >>> + } >>> + >>> /* See if the pointers point to incompatible address spaces. */ >>> asl =3D TYPE_ADDR_SPACE (ttl); >>> asr =3D TYPE_ADDR_SPACE (ttr); >>> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi >>> index 88e3c625030..6869bed64c3 100644 >>> --- a/gcc/doc/invoke.texi >>> +++ b/gcc/doc/invoke.texi >>> @@ -8076,6 +8076,15 @@ always leads to a call to another @code{cold} >>> function such as wrappers of >>> C++ @code{throw} or fatal error reporting functions leading to >>> @code{abort}. >>> @end table >>>=20 >>> +@opindex Wno-alloc-type >>> +@opindex Walloc-type >>> +@item -Walloc-type >>> +Warn about calls to allocation functions decorated with attribute >>> +@code{alloc_size} that specify insufficient size for the target type >>> of >>> +the pointer the result is assigned to, including those to the built-in >>> +forms of the functions @code{aligned_alloc}, @code{alloca}, >>> @code{calloc}, >>> +@code{malloc}, and @code{realloc}. >>> + >>> @opindex Wno-alloc-zero >>> @opindex Walloc-zero >>> @item -Walloc-zero >>> diff --git a/gcc/testsuite/gcc.dg/Walloc-type-1.c >>> b/gcc/testsuite/gcc.dg/Walloc-type-1.c >>> new file mode 100644 >>> index 00000000000..bc62e5e9aa3 >>> --- /dev/null >>> +++ b/gcc/testsuite/gcc.dg/Walloc-type-1.c >>> @@ -0,0 +1,37 @@ >>> +/* Tests the warnings for insufficient allocation size. >>> + { dg-do compile } >>> + * { dg-options "-Walloc-type" } >>> + * */ >>> +#include >>> +#include >>> + >>> +struct b { int x[10]; }; >>> + >>> +void fo0(void) >>> +{ >>> + struct b *p =3D malloc(sizeof *p); >>> +} >>> + >>> +void fo1(void) >>> +{ >>> + struct b *p =3D malloc(sizeof p); /* { dg- >>> warning "allocation of insufficient size" } */ >>> +} >>> + >>> +void fo2(void) >>> +{ >>> + struct b *p =3D alloca(sizeof p); /* { dg- >>> warning "allocation of insufficient size" } */ >>> +} >>> + >>> +void fo3(void) >>> +{ >>> + struct b *p =3D calloc(1, sizeof p); /* { dg-warning >>> "allocation of insufficient size" } */ >>> +} >>> + >>> +void g(struct b* p); >>> + >>> +void fo4(void) >>> +{ >>> + g(malloc(4)); /* { dg-warning "allocation of >>> insufficient size" } */ >>> +} >>> + >>> + >>>=20 >>>=20 >>>=20 >=20 > --=20 > Univ.-Prof. Dr. rer. nat. Martin Uecker > Graz University of Technology > Institute of Biomedical Imaging