https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104475
--- Comment #17 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:926f5059bb8d295e2b68cea7c9af53606946eb1a commit r13-4503-g926f5059bb8d295e2b68cea7c9af53606946eb1a Author: Richard Biener <rguent...@suse.de> Date: Tue Dec 6 10:12:01 2022 +0100 tree-optimization/104475 - improve access diagnostics When we end up isolating a nullptr path it happens we diagnose accesses to offsetted nullptr objects. The current diagnostics have no good indication that this happens so the following records the fact that our heuristic detected a nullptr based access in the access_ref structure and sets up diagnostics to inform of that detail. The diagnostic itself could probably be improved here but its API is twisted and the necessary object isn't passed around. Instead of just ...bits/atomic_base.h:655:34: warning: 'unsigned int __atomic_fetch_and_4(volatile void*, unsigned int, int)' writing 4 bytes into a region of size 0 overflows the destination [-Wstringop-overflow=] we now add In member function 'void QFutureInterfaceBase::setThrottled(bool)': cc1plus: note: destination object is likely at address zero PR tree-optimization/104475 * pointer-query.h (access_ref::ref_nullptr_p): New flag. * pointer-query.cc (access_ref::access_ref): Initialize ref_nullptr_p. (compute_objsize_r): Set ref_nullptr_p if we treat it that way. (access_ref::inform_access): If ref was treated as nullptr based, indicate that.
