From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id E47163851C39; Thu, 15 Jul 2021 19:09:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E47163851C39 From: "cvs-commit at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/94714] Analyzer: no warning on access of an uninitialized variable of automatic storage duration Date: Thu, 15 Jul 2021 19:09:17 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: analyzer X-Bugzilla-Version: 10.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: cvs-commit at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: dmalcolm at gcc dot gnu.org X-Bugzilla-Target-Milestone: 11.2 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Jul 2021 19:09:18 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94714 --- Comment #3 from CVS Commits --- The master branch has been updated by David Malcolm : https://gcc.gnu.org/g:33255ad3ac14e3953750fe0f2d82b901c2852ff6 commit r12-2337-g33255ad3ac14e3953750fe0f2d82b901c2852ff6 Author: David Malcolm Date: Thu Jul 15 15:07:07 2021 -0400 analyzer: reimplement -Wanalyzer-use-of-uninitialized-value [PR95006 et= al] The initial gcc 10 era commit of the analyzer (in 757bf1dff5e8cee34c0a75d06140ca972bfecfa7) had an implementation of -Wanalyzer-use-of-uninitialized-value, but was sufficiently buggy that I removed it in 78b9783774bfd3540f38f5b1e3c7fc9f719653d7 before the release of gcc 10.1 This patch reintroduces the warning, heavily rewritten, with (I hope) a less buggy implementation this time, for GCC 12. gcc/analyzer/ChangeLog: PR analyzer/95006 PR analyzer/94713 PR analyzer/94714 * analyzer.cc (maybe_reconstruct_from_def_stmt): Split out GIMPLE_ASSIGN case into... (get_diagnostic_tree_for_gassign_1): New. (get_diagnostic_tree_for_gassign): New. * analyzer.h (get_diagnostic_tree_for_gassign): New decl. * analyzer.opt (Wanalyzer-write-to-string-literal): New. * constraint-manager.cc (class svalue_purger): New. (constraint_manager::purge_state_involving): New. * constraint-manager.h (constraint_manager::purge_state_involving): New. * diagnostic-manager.cc (saved_diagnostic::supercedes_p): New. (dedupe_winners::handle_interactions): New. (diagnostic_manager::emit_saved_diagnostics): Call it. * diagnostic-manager.h (saved_diagnostic::supercedes_p): New de= cl. * engine.cc (impl_region_model_context::warn): Convert return t= ype to bool. Return false if the diagnostic isn't saved. (impl_region_model_context::purge_state_involving): New. (impl_sm_context::get_state): Use NULL ctxt when querying old rvalue. (impl_sm_context::set_next_state): Use new sval when querying o= ld state. (class dump_path_diagnostic): Move to region-model.cc (exploded_node::on_stmt): Move to on_stmt_pre and on_stmt_post. Remove call to purge_state_involving. (exploded_node::on_stmt_pre): New, based on the above. Move mo= st of it to region_model::on_stmt_pre. (exploded_node::on_stmt_post): Likewise, moving to region_model::on_stmt_post. (class stale_jmp_buf): Fix parent class to use curiously recurr= ing template pattern. (feasibility_state::maybe_update_for_edge): Call on_call_pre and on_call_post on gcalls. * exploded-graph.h (impl_region_model_context::warn): Return bo= ol. (impl_region_model_context::purge_state_involving): New decl. (exploded_node::on_stmt_pre): New decl. (exploded_node::on_stmt_post): New decl. * pending-diagnostic.h (pending_diagnostic::use_of_uninit_p): N= ew. (pending_diagnostic::supercedes_p): New. * program-state.cc (sm_state_map::get_state): Inherit state for conjured_svalue as well as initial_svalue. (sm_state_map::purge_state_involving): Also support SK_CONJURED. * region-model-impl-calls.cc (call_details::get_uncertainty): Handle m_ctxt being NULL. (call_details::get_or_create_conjured_svalue): New. (region_model::impl_call_fgets): New. (region_model::impl_call_fread): New. * region-model-manager.cc (region_model_manager::get_or_create_initial_value): Return an uninitialized poisoned value for regions that can't have initial values. * region-model-reachability.cc (reachable_regions::mark_escaped_clusters): Handle ctxt being NULL. * region-model.cc (region_to_value_map::purge_state_involving): New. (poisoned_value_diagnostic::use_of_uninit_p): New. (poisoned_value_diagnostic::emit): Handle POISON_KIND_UNINIT. (poisoned_value_diagnostic::describe_final_event): Likewise. (region_model::check_for_poison): New. (region_model::on_assignment): Call it. (class dump_path_diagnostic): Move here from engine.cc. (region_model::on_stmt_pre): New, based on exploded_node::on_st= mt. (region_model::on_call_pre): Move the setting of the LHS to a conjured svalue to before the checks for specific functions. Handle "fgets", "fgets_unlocked", and "fread". (region_model::purge_state_involving): New. (region_model::handle_unrecognized_call): Handle ctxt being NUL= L. (region_model::get_rvalue): Call check_for_poison. (selftest::test_stack_frames): Use NULL for context when getting uninitialized rvalue. (selftest::test_alloca): Likewise. * region-model.h (region_to_value_map::purge_state_involving): = New decl. (call_details::get_or_create_conjured_svalue): New decl. (region_model::on_stmt_pre): New decl. (region_model::purge_state_involving): New decl. (region_model::impl_call_fgets): New decl. (region_model::impl_call_fread): New decl. (region_model::check_for_poison): New decl. (region_model_context::warn): Return bool. (region_model_context::purge_state_involving): New. (noop_region_model_context::warn): Return bool. (noop_region_model_context::purge_state_involving): New. (test_region_model_context:: warn): Return bool. * region.cc (region::get_memory_space): New. (region::can_have_initial_svalue_p): New. (region::involves_p): New. * region.h (enum memory_space): New. (region::get_memory_space): New decl. (region::can_have_initial_svalue_p): New decl. (region::involves_p): New decl. * sm-malloc.cc (use_after_free::supercedes_p): New. * store.cc (binding_cluster::purge_state_involving): New. (store::purge_state_involving): New. * store.h (class symbolic_binding): New forward decl. (binding_key::dyn_cast_symbolic_binding): New. (symbolic_binding::dyn_cast_symbolic_binding): New. (binding_cluster::purge_state_involving): New. (store::purge_state_involving): New. * svalue.cc (svalue::can_merge_p): Reject attempts to merge poisoned svalues with other svalues, so that we identify paths in which a variable is conditionally uninitialized. (involvement_visitor::visit_conjured_svalue): New. (svalue::involves_p): Also handle SK_CONJURED. (poison_kind_to_str): Handle POISON_KIND_UNINIT. (poisoned_svalue::maybe_fold_bits_within): New. * svalue.h (enum poison_kind): Add POISON_KIND_UNINIT. (poisoned_svalue::maybe_fold_bits_within): New decl. gcc/ChangeLog: PR analyzer/95006 PR analyzer/94713 PR analyzer/94714 * doc/invoke.texi: Add -Wanalyzer-use-of-uninitialized-value. gcc/testsuite/ChangeLog: PR analyzer/95006 PR analyzer/94713 PR analyzer/94714 * g++.dg/analyzer/pr93212.C: Update location of warning. * g++.dg/analyzer/pr94011.C: Add -Wno-analyzer-use-of-uninitialized-value. * g++.dg/analyzer/pr94503.C: Likewise. * gcc.dg/analyzer/clobbers-1.c: Convert "f" from a local to a param to avoid uninitialized warning. * gcc.dg/analyzer/data-model-1.c (test_12): Add test for uninitialized value on result of alloca. (test_12a): Add expected warning. (test_12c): Likewise. (test_19): Likewise. (test_29b): Likewise. (test_29c): Likewise. (test_37): Remove xfail. (test_37a): Likewise. * gcc.dg/analyzer/data-model-20.c: Add warning about leak. * gcc.dg/analyzer/explode-2.c: Remove params; add -Wno-analyzer-too-complex, -Wno-analyzer-malloc-leak, and xfail= s. Initialize the locals. * gcc.dg/analyzer/explode-2a.c: Initialize the locals. Add expected leak. * gcc.dg/analyzer/fgets-1.c: New test. * gcc.dg/analyzer/fread-1.c: New test. * gcc.dg/analyzer/malloc-1.c (test_16): Add expected warning. (test_40): Likewise. * gcc.dg/analyzer/memset-CVE-2017-18549-1.c: Check for uninitialized padding. * gcc.dg/analyzer/pr93355-localealias-feasibility.c (fread): New decl. (read_alias_file): Call it. * gcc.dg/analyzer/pr94047.c: Add expected warnings. * gcc.dg/analyzer/pr94851-2.c: Likewise. * gcc.dg/analyzer/pr96841.c: Convert local to a param. * gcc.dg/analyzer/pr98628.c: Likewise. * gcc.dg/analyzer/pr99042.c: Updated expected location of leak diagnostics. * gcc.dg/analyzer/symbolic-1.c: Add expected warnings. * gcc.dg/analyzer/symbolic-7.c: Likewise. * gcc.dg/analyzer/torture/pr93649.c: Add expected warning. Skip with -fno-fat-lto-objects. * gcc.dg/analyzer/uninit-1.c: New test. * gcc.dg/analyzer/uninit-2.c: New test. * gcc.dg/analyzer/uninit-3.c: New test. * gcc.dg/analyzer/uninit-4.c: New test. * gcc.dg/analyzer/uninit-pr94713.c: New test. * gcc.dg/analyzer/uninit-pr94714.c: New test. * gcc.dg/analyzer/use-after-free-2.c: New test. * gcc.dg/analyzer/use-after-free-3.c: New test. * gcc.dg/analyzer/zlib-3.c: Add expected warning. * gcc.dg/analyzer/zlib-6.c: Convert locals to params to avoid uninitialized warnings. Remove xfail. * gcc.dg/analyzer/zlib-6a.c: New test, based on the old version of the above. * gfortran.dg/analyzer/pr97668.f: Add -Wno-analyzer-use-of-uninitialized-value and -Wno-analyzer-too-complex. Signed-off-by: David Malcolm =