https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104270
--- Comment #2 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:9b4eee5fd158c4ee75d1f1000debbf5082fb9b56 commit r12-6997-g9b4eee5fd158c4ee75d1f1000debbf5082fb9b56 Author: David Malcolm <dmalc...@redhat.com> Date: Fri Jan 28 11:02:09 2022 -0500 analyzer: stop -ftrivial-auto-var-init from suppressing uninit warnings [PR104270] GCC 12 has gained two features for dealing with uninitialized variables: (a) a new -Wanalyzer-use-of-uninitialized-value warning within -fanalyzer for interprocedural path-sensitive detection of ununit uses, and (b) a new -ftrivial-auto-var-init option for mitigating some uses of uninit variables It turns out that using (b) was thwarting (a), as it led to -fanalyzer seeing calls to IFN_DEFERRED_INIT, which -fanalyzer wasn't special-casing, thus treating it as initializing the variables in question, and thus silencing -Wanalyzer-use-of-uninitialized-value on them. invoke.texi says: "GCC still considers an automatic variable that doesn't have an explicit initializer as uninitialized, @option{-Wuninitialized} will still report warning messages on such automatic variables." and thus -Wanalyzer-use-of-uninitialized-value ought to as well. This patch adds special-case handling to -fanalyzer for IFN_DEFERRED_INIT, so that -fanalyzer will warn on uninit uses of variables that are mitigated by -ftrivial-auto-var-init. gcc/analyzer/ChangeLog: PR analyzer/104270 * region-model.cc (region_model::on_call_pre): Handle IFN_DEFERRED_INIT. gcc/testsuite/ChangeLog: PR analyzer/104270 * gcc.dg/analyzer/uninit-trivial-auto-var-init-pattern.c: New test. * gcc.dg/analyzer/uninit-trivial-auto-var-init-uninitialized.c: New test. * gcc.dg/analyzer/uninit-trivial-auto-var-init-zero.c: New test. Signed-off-by: David Malcolm <dmalc...@redhat.com>
