From patchwork Sat Mar 23 13:55:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Malcolm X-Patchwork-Id: 1915167 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=MjOjHqvO; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org (client-ip=2620:52:3:1:0:246e:9693:128c; helo=server2.sourceware.org; envelope-from=gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org; receiver=patchwork.ozlabs.org) Received: from server2.sourceware.org (server2.sourceware.org [IPv6:2620:52:3:1:0:246e:9693:128c]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4V211Q4b0Lz1yYG for ; Sun, 24 Mar 2024 00:55:38 +1100 (AEDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 59A823858D38 for ; Sat, 23 Mar 2024 13:55:36 +0000 (GMT) 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 90E833858D28 for ; Sat, 23 Mar 2024 13:55:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 90E833858D28 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 90E833858D28 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1711202117; cv=none; b=iFm+Q9PWFtZEPYee8wliY7JjA1RulwzZkCuMwSdZB0ozWj6k8yM2nbUZTD/pWHE2LQ9g/oFxov6TJIHky3sP8yWIBxuEtdyEJAsXfKdAOpHgduEWYu1yBW7fFDrT7GxrX64Yz7e2MdBTHPXBRcG/cEniVxGpGH9tLlLRLM+2MZw= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1711202117; c=relaxed/simple; bh=iBwwx+6aR/BD0tCYOGcErw2A4ndSdSTvLGC8qvbwnyc=; h=DKIM-Signature:From:To:Subject:Date:Message-Id:MIME-Version; b=Z2QfpzjiC5J/9xvI5axRl7XRD5bNkwFifs016GBXp6sTaX4UWeCSVtpaCz5B2Hj3t4eFhREV6WIStnYW/heAjudQcZXDQN3OXe23c6pIuINbq30qdUVjQlVAzhpZu0KAaDSFzgv2L2Ub5llhI9+AUtnl8VUlXsNPMcxvfm8TAYU= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711202115; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=4uXOV1JIdfZl3eiy+7HrOQJHaZpua/vNVB59wiP9nTY=; b=MjOjHqvOFcgQo1xFD717y7S4cK56d/pJFeHgqOJHZHvBq0/nXw2rhpyQPjal3XpI2TPh9g N0/lRwbbfOhW02q8KDxJu7Bp533KKqHYoFMMZhnjEFc/BuUladrHbY6T8QT8Lew1uopzmq UziQ3AoV9b6oG8iLMxye+7nwt6eDzvA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-687-M-8qQoiLNkqSFs63V-YDMw-1; Sat, 23 Mar 2024 09:55:13 -0400 X-MC-Unique: M-8qQoiLNkqSFs63V-YDMw-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 09C2F8007A2 for ; Sat, 23 Mar 2024 13:55:13 +0000 (UTC) Received: from t14s.localdomain.com (unknown [10.22.32.20]) by smtp.corp.redhat.com (Postfix) with ESMTP id D404E492BD0; Sat, 23 Mar 2024 13:55:12 +0000 (UTC) From: David Malcolm To: gcc-patches@gcc.gnu.org Cc: David Malcolm Subject: [pushed] analyzer: fix ICE and false positive with -Wanalyzer-deref-before-check [PR114408] Date: Sat, 23 Mar 2024 09:55:07 -0400 Message-Id: <20240323135507.1148489-1-dmalcolm@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-11.5 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_H4, RCVD_IN_MSPIKE_WL, 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: 2.1.30 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: gcc-patches-bounces+incoming=patchwork.ozlabs.org@gcc.gnu.org Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. Successful run of analyzer integration tests on x86_64-pc-linux-gnu. Pushed to trunk as r14-9646-g80a0cb37456c49. gcc/analyzer/ChangeLog: PR analyzer/114408 * engine.cc (impl_run_checkers): Free up any dominance info that we may have created. * kf.cc (class kf_ubsan_handler): New. (register_sanitizer_builtins): New. (register_known_functions): Call register_sanitizer_builtins. gcc/testsuite/ChangeLog: PR analyzer/114408 * c-c++-common/analyzer/deref-before-check-pr114408.c: New test. * c-c++-common/ubsan/analyzer-ice-pr114408.c: New test. Signed-off-by: David Malcolm --- gcc/analyzer/engine.cc | 7 ++++++ gcc/analyzer/kf.cc | 22 +++++++++++++++++++ .../analyzer/deref-before-check-pr114408.c | 22 +++++++++++++++++++ .../ubsan/analyzer-ice-pr114408.c | 9 ++++++++ 4 files changed, 60 insertions(+) create mode 100644 gcc/testsuite/c-c++-common/analyzer/deref-before-check-pr114408.c create mode 100644 gcc/testsuite/c-c++-common/ubsan/analyzer-ice-pr114408.c diff --git a/gcc/analyzer/engine.cc b/gcc/analyzer/engine.cc index ad310b4d8731..e0dc0e66e88c 100644 --- a/gcc/analyzer/engine.cc +++ b/gcc/analyzer/engine.cc @@ -6251,6 +6251,13 @@ impl_run_checkers (logger *logger) eng.get_model_manager ()->dump_untracked_regions (); delete purge_map; + + /* Free up any dominance info that we may have created. */ + FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) + { + function *fun = node->get_fun (); + free_dominance_info (fun, CDI_DOMINATORS); + } } /* Handle -fdump-analyzer and -fdump-analyzer-stderr. */ diff --git a/gcc/analyzer/kf.cc b/gcc/analyzer/kf.cc index d197ccbd0f05..6931f07bd75e 100644 --- a/gcc/analyzer/kf.cc +++ b/gcc/analyzer/kf.cc @@ -2198,6 +2198,27 @@ register_atomic_builtins (known_function_manager &kfm) make_unique (BIT_IOR_EXPR)); } +/* Handle calls to the various __builtin___ubsan_handle_*. + These can return, but continuing after such a return + isn't likely to be interesting to the user of the analyzer. + Hence we terminate the analysis path at one of these calls. */ + +class kf_ubsan_handler : public internal_known_function +{ + void impl_call_post (const call_details &cd) const final override + { + if (cd.get_ctxt ()) + cd.get_ctxt ()->terminate_path (); + } +}; + +static void +register_sanitizer_builtins (known_function_manager &kfm) +{ + kfm.add (BUILT_IN_UBSAN_HANDLE_NONNULL_ARG, + make_unique ()); +} + /* Populate KFM with instances of known functions supported by the core of the analyzer (as opposed to plugins). */ @@ -2224,6 +2245,7 @@ register_known_functions (known_function_manager &kfm, kfm.add (BUILT_IN_STACK_SAVE, make_unique ()); register_atomic_builtins (kfm); + register_sanitizer_builtins (kfm); register_varargs_builtins (kfm); } diff --git a/gcc/testsuite/c-c++-common/analyzer/deref-before-check-pr114408.c b/gcc/testsuite/c-c++-common/analyzer/deref-before-check-pr114408.c new file mode 100644 index 000000000000..d55720271d0f --- /dev/null +++ b/gcc/testsuite/c-c++-common/analyzer/deref-before-check-pr114408.c @@ -0,0 +1,22 @@ +extern void unknown_returns (const char *p); +extern void unknown_noreturn (const char *p) __attribute__((__noreturn__)); + +void test_1 (const char *p) +{ + if (p) + unknown_returns (p); + __builtin_strcmp ("a", p); /* { dg-message "pointer 'p' is dereferenced here" "" { target c } } */ + if (p) /* { dg-warning "check of 'p' for NULL after already dereferencing it" "" { target c } } */ + unknown_returns (p); + __builtin_strcmp ("a", p); +} + +void test_2 (const char *p) +{ + if (p) + unknown_noreturn (p); + __builtin_strcmp ("a", p); + if (p) /* { dg-bogus "check of 'p' for NULL after already dereferencing it" } */ + unknown_noreturn (p); + __builtin_strcmp ("a", p); +} diff --git a/gcc/testsuite/c-c++-common/ubsan/analyzer-ice-pr114408.c b/gcc/testsuite/c-c++-common/ubsan/analyzer-ice-pr114408.c new file mode 100644 index 000000000000..55f918726eed --- /dev/null +++ b/gcc/testsuite/c-c++-common/ubsan/analyzer-ice-pr114408.c @@ -0,0 +1,9 @@ +/* { dg-do run } */ +/* { dg-require-effective-target analyzer } */ +/* { dg-options "-fanalyzer -fsanitize=undefined" } */ + +int main(){} + +int HMAP_unset_copy(const char *key) { + return __builtin_strcmp("a", key) + __builtin_strcmp("a", key); +}