https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106204
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>: https://gcc.gnu.org/g:09cb9c88ef8e2c0c89ada9cde2caf1a960db7a77 commit r12-8637-g09cb9c88ef8e2c0c89ada9cde2caf1a960db7a77 Author: David Malcolm <dmalc...@redhat.com> Date: Wed Jul 27 17:38:55 2022 -0400 analyzer: fix uninit false positive with -ftrivial-auto-var-init= [PR106204] (cherry picked from r13-1517-gb33dd7874523af) -fanalyzer handles -ftrivial-auto-var-init= by special-casing IFN_DEFERRED_INIT to be a no-op, so that e.g.: len_2 = .DEFERRED_INIT (4, 2, &"len"[0]); is treated as a no-op, so that len_2 is still uninitialized after the stmt. PR analyzer/106204 reports that -fanalyzer gives false positives from -Wanalyzer-use-of-uninitialized-value on locals that have their address taken, due to e.g.: _1 = .DEFERRED_INIT (4, 2, &"len"[0]); len = _1; where -fanalyzer leaves _1 uninitialized, and then complains about the assignment to "len". Fixed thusly by suppressing the warning when assigning from such SSA names. gcc/analyzer/ChangeLog: PR analyzer/106204 * region-model.cc (within_short_circuited_stmt_p): Move extraction of assign_stmt to caller. (due_to_ifn_deferred_init_p): New. (region_model::check_for_poison): Move extraction of assign_stmt from within_short_circuited_stmt_p to here. Share logic with call to due_to_ifn_deferred_init_p. gcc/testsuite/ChangeLog: PR analyzer/106204 * gcc.dg/analyzer/torture/uninit-pr106204.c: New test. * gcc.dg/analyzer/uninit-pr106204.c: New test. Signed-off-by: David Malcolm <dmalc...@redhat.com>
