From patchwork Fri Dec 2 02:35:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Malcolm X-Patchwork-Id: 61337 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 E99113858431 for ; Fri, 2 Dec 2022 02:36:29 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E99113858431 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1669948590; bh=Tim/qqzs7MaRVCyQzEZ3rcb0jFGg4irZ6hKUUqg9PUc=; h=To:Cc:Subject:Date:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=lwk6r2UiuVTkNPGyjcpwfYnPsQ3Vj7/1+sD6ryVjFZdKu9S9WY9hbXSA9Jc2PGQSX tgKm0KAbUJGJoAey9DVuCGZ51+Mj75gMhfl3RJjsiJDlxlAk+wgAKEM4KOOBh7nOK4 fNbHqDF+3hmrDgVCyIMsRPRZgzXLuevdLHl3ojRM= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id BC6FB3858430 for ; Fri, 2 Dec 2022 02:35:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org BC6FB3858430 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-645-jKOWJ75JMI2m6o-HSsuOuQ-1; Thu, 01 Dec 2022 21:35:58 -0500 X-MC-Unique: jKOWJ75JMI2m6o-HSsuOuQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E8D773806704 for ; Fri, 2 Dec 2022 02:35:57 +0000 (UTC) Received: from t14s.localdomain.com (unknown [10.2.16.65]) by smtp.corp.redhat.com (Postfix) with ESMTP id C069F6352E; Fri, 2 Dec 2022 02:35:57 +0000 (UTC) To: gcc-patches@gcc.gnu.org Cc: David Malcolm Subject: [committed] analyzer: handle comparisons against negated symbolic values [PR107948] Date: Thu, 1 Dec 2022 21:35:54 -0500 Message-Id: <20221202023554.3778168-1-dmalcolm@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-11.9 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, 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: David Malcolm via Gcc-patches From: David Malcolm Reply-To: David Malcolm Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. Pushed to trunk as r13-4456-g0b737090a69624. gcc/analyzer/ChangeLog: PR analyzer/107948 * region-model-manager.cc (region_model_manager::maybe_fold_binop): Fold (0 - VAL) to -VAL. * region-model.cc (region_model::eval_condition): Handle e.g. "-X <= 0" as equivalent to X >= 0". gcc/testsuite/ChangeLog: PR analyzer/107948 * gcc.dg/analyzer/feasibility-pr107948.c: New test. Signed-off-by: David Malcolm --- gcc/analyzer/region-model-manager.cc | 3 ++ gcc/analyzer/region-model.cc | 13 +++++ .../gcc.dg/analyzer/feasibility-pr107948.c | 49 +++++++++++++++++++ 3 files changed, 65 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c diff --git a/gcc/analyzer/region-model-manager.cc b/gcc/analyzer/region-model-manager.cc index ae63c664ae5..471a9272e41 100644 --- a/gcc/analyzer/region-model-manager.cc +++ b/gcc/analyzer/region-model-manager.cc @@ -620,6 +620,9 @@ region_model_manager::maybe_fold_binop (tree type, enum tree_code op, /* (VAL - 0) -> VAL. */ if (cst1 && zerop (cst1)) return get_or_create_cast (type, arg0); + /* (0 - VAL) -> -VAL. */ + if (cst0 && zerop (cst0)) + return get_or_create_unaryop (type, NEGATE_EXPR, arg1); break; case MULT_EXPR: /* (VAL * 0). */ diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc index 91b868f7b16..4f623fd6ca3 100644 --- a/gcc/analyzer/region-model.cc +++ b/gcc/analyzer/region-model.cc @@ -3339,6 +3339,19 @@ region_model::eval_condition (const svalue *lhs, return lhs_ts; } } + else if (const unaryop_svalue *unaryop + = lhs->dyn_cast_unaryop_svalue ()) + { + if (unaryop->get_op () == NEGATE_EXPR) + { + /* e.g. "-X <= 0" is equivalent to X >= 0". */ + tristate lhs_ts = eval_condition (unaryop->get_arg (), + swap_tree_comparison (op), + rhs); + if (lhs_ts.is_known ()) + return lhs_ts; + } + } } /* Handle rejection of equality for comparisons of the initial values of diff --git a/gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c b/gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c new file mode 100644 index 00000000000..5eb8b0aef22 --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/feasibility-pr107948.c @@ -0,0 +1,49 @@ +#include "analyzer-decls.h" + +void foo(int width) { + int i = 0; + int base; + if (width > 0){ + __analyzer_eval(i == 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(width > 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(width - i > 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(i - width <= 0); /* { dg-warning "TRUE" } */ + if (i - width <= 0) { + base = 512; + } + else { + __analyzer_dump_path (); /* { dg-bogus "path" } */ + } + base+=1; /* { dg-bogus "uninit" } */ + } +} + +void test_ge_zero (int x) +{ + if (x >= 0) + { + __analyzer_eval(x >= 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(x > 0); /* { dg-warning "UNKNOWN" } */ + __analyzer_eval(x <= 0); /* { dg-warning "UNKNOWN" } */ + __analyzer_eval(x < 0); /* { dg-warning "FALSE" } */ + __analyzer_eval(-x <= 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(-x < 0); /* { dg-warning "UNKNOWN" } */ + __analyzer_eval(-x >= 0); /* { dg-warning "UNKNOWN" } */ + __analyzer_eval(-x > 0); /* { dg-warning "FALSE" } */ + } +} + +void test_gt_zero (int x) +{ + if (x > 0) + { + __analyzer_eval(x >= 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(x > 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(x <= 0); /* { dg-warning "FALSE" } */ + __analyzer_eval(x < 0); /* { dg-warning "FALSE" } */ + __analyzer_eval(-x <= 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(-x < 0); /* { dg-warning "TRUE" } */ + __analyzer_eval(-x >= 0); /* { dg-warning "FALSE" } */ + __analyzer_eval(-x > 0); /* { dg-warning "FALSE" } */ + } +}