https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102630
Bug ID: 102630
Summary: [12 Regression] Spurious -Warray-bounds with named
address space
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: jsm28 at gcc dot gnu.org
CC: msebor at gcc dot gnu.org
Target Milestone: ---
Target: x86_64-*-*
Created attachment 51560
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51560&action=edit
preprocessed source
This is the issue breaking building glibc for x86_64 with current mainline GCC
(since July), as previously discussed in threads starting at
https://gcc.gnu.org/pipermail/gcc/2021-July/236922.html and
https://gcc.gnu.org/pipermail/gcc/2021-July/236933.html (discussion continues
into August).
Compile the attached file with -O2 -Wall -Werror and get the errors:
loadmsgcat.c: In function '_nl_load_domain':
loadmsgcat.c:770:22: error: array subscript 0 is outside array bounds of
'__seg_fs struct pthread * __seg_fs[0]' [-Werror=array-bounds]
As discussed in the previous discussions, the code generating this
-Warray-bounds warning needs to check targetm.addr_space.zero_address_valid to
determine whether zero or small constant addresses are valid in the given
address space (there's already a suitable definition of that hook for x86, but
the warning is failing to check it).
