https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107882
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>: https://gcc.gnu.org/g:dfe2ef7f2b6cac7017f32a0a04f74e1b6d9f1311 commit r13-4529-gdfe2ef7f2b6cac7017f32a0a04f74e1b6d9f1311 Author: David Malcolm <dmalc...@redhat.com> Date: Tue Dec 6 18:24:16 2022 -0500 analyzer: don't create bindings or binding keys for empty regions [PR107882] PR analyzer/107882 reports an ICE, due to trying to get a compound svalue for this binding: cluster for: a: key: {bytes 0-3} value: {UNKNOWN()} key: {empty} value: {UNKNOWN()} key: {bytes 4-7} value: {UNKNOWN()} where there's an binding to the unknown value of zero bits in size "somewhere" within "a" (perhaps between bits 3 and 4?) This makes no sense, so this patch adds an assertion that we never attempt to create a binding key for an empty region, and adds early rejection of attempts to get or set the values of such regions, fixing the ICE. gcc/analyzer/ChangeLog: PR analyzer/107882 * region-model.cc (region_model::get_store_value): Return an unknown value for empty regions. (region_model::set_value): Bail on empty regions. * region.cc (region::empty_p): New. * region.h (region::empty_p): New decl. * state-purge.cc (same_binding_p): Bail if either region is empty. * store.cc (binding_key::make): Assert that a concrete binding's bit_size must be > 0. (binding_cluster::mark_region_as_unknown): Bail on empty regions. (binding_cluster::get_binding): Likewise. (binding_cluster::remove_overlapping_bindings): Likewise. (binding_cluster::on_unknown_fncall): Don't conjure values for empty regions. (store::fill_region): Bail on empty regions. * store.h (class concrete_binding): Update comment to reflect that the range of bits must be non-empty. (concrete_binding::concrete_binding): Assert that bit range is non-empty. gcc/testsuite/ChangeLog: PR analyzer/107882 * gcc.dg/analyzer/memcpy-pr107882.c: New test. Signed-off-by: David Malcolm <dmalc...@redhat.com>
