https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119941
Bug ID: 119941
Summary: -Warray-bounds warning in
adjust_offset_for_component_ref when building for
bpf-unknown-none
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Keywords: build
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
Target Milestone: ---
When building a cross-compiler for bpf-unknown-none with LTO and -O3, I saw:
```
In function ‘canonize’,
inlined from ‘arshift_large’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.cc:2173:19,
inlined from ‘arshift’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.h:3700:17,
inlined from ‘operator>>’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.h:3871:22,
inlined from
‘_ZL31adjust_offset_for_component_refP9tree_nodePbP8poly_intILj1ElE.part.0’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/alias.cc:2793:11:
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.cc:95:7:
warning: array subscript 4294967295 is outside array bounds of ‘struct
signed_shift_result_type[1]’ [-Warray-bounds=]
95 | top = val[len - 1];
| ^
‘_ZL31adjust_offset_for_component_refP9tree_nodePbP8poly_intILj1ElE.part.0’:
events 1-2
92 | if (len == 1)
| ^
| |
| (1) when the condition is evaluated to false
......
95 | top = val[len - 1];
| ~
| |
| (2) out of array bounds here
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/alias.cc: In
function
‘_ZL31adjust_offset_for_component_refP9tree_nodePbP8poly_intILj1ElE.part.0’:
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/alias.cc:2793:18:
note: at offset 34359738360 into object ‘<anonymous>’ of size 24
2793 | >> LOG2_BITS_PER_UNIT)
| ^
In function ‘canonize’,
inlined from ‘arshift_large’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.cc:2173:19,
inlined from ‘arshift’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.h:3700:17,
inlined from ‘operator>>’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.h:3871:22,
inlined from
‘_ZL31adjust_offset_for_component_refP9tree_nodePbP8poly_intILj1ElE.part.0’ at
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/alias.cc:2793:11:
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/wide-int.cc:95:7:
warning: array subscript 4294967295 is outside array bounds of ‘struct
signed_shift_result_type[1]’ [-Warray-bounds=]
95 | top = val[len - 1];
| ^
‘_ZL31adjust_offset_for_component_refP9tree_nodePbP8poly_intILj1ElE.part.0’:
events 1-2
92 | if (len == 1)
| ^
| |
| (1) when the condition is evaluated to false
......
95 | top = val[len - 1];
| ~
| |
| (2) out of array bounds here
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/alias.cc: In
function
‘_ZL31adjust_offset_for_component_refP9tree_nodePbP8poly_intILj1ElE.part.0’:
/var/tmp/portage/sys-devel/bpf-toolchain-15.1.0_p1/work/gcc/gcc/alias.cc:2793:18:
note: at offset 34359738360 into object ‘<anonymous>’ of size 24
2793 | >> LOG2_BITS_PER_UNIT)
```
