> -----Original Message----- > From: Gcc-patches <gcc-patches- > bounces+kyrylo.tkachov=arm....@gcc.gnu.org> On Behalf Of Martin Sebor > via Gcc-patches > Sent: 10 July 2021 00:11 > To: gcc-patches <gcc-patches@gcc.gnu.org>; Christophe Lyon > <christophe.l...@linaro.org> > Subject: [PATCH libatomic/arm] avoid warning on constant addresses (PR > 101379) > > The attached tweak avoids the new -Warray-bounds instances when > building libatomic for arm. Christophe confirms it resolves > the problem (thank you!) > > As we have discussed, the main goal of this class of warnings > is to detect accesses at addresses derived from null pointers > (e.g., to struct members or array elements at a nonzero offset). > Diagnosing accesses at hardcoded addresses is incidental because > at the stage they are detected the two are not distinguishable > from each another. > > I'm planning (hoping) to implement detection of invalid pointer > arithmetic involving null for GCC 12, so this patch is a stopgap > solution to unblock the arm libatomic build without compromising > the warning. Once the new detection is in place these workarounds > can be removed or replaced with something more appropriate (e.g., > declaring the objects at the hardwired addresses with an attribute > like AVR's address or io; that would enable bounds checking at > those addresses as well).
Let's get this patch in to unbreak bootstrap while the discussion on how to avoid these workarounds continues... So ok. Thanks, Kyrill > > Martin
