https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90525
Bug ID: 90525
Summary: Wrong offsets in warning text for -Warray-bounds (with
subobject)
Product: gcc
Version: 9.1.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: miguel.ojeda.sandonis at gmail dot com
Target Milestone: ---
When fixing an -Warray-bounds warning for the kernel I noticed that the offsets
were off-by-1 in at least one of the warning texts. For instance:
struct T { char a, b, c; } t;
void f(void) { __builtin_memset(&t.a, 0, 3); }
gives:
x.c: In function 'f':
x.c:2:16: warning: '__builtin_memset' offset [2, 3] from the object at 't'
is out of the bounds of referenced subobject 'a' with type 'char' at offset 0
[-Warray-bounds]
2 | void f(void) { __builtin_memset(&t.a, 0, 3); }
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
Instead of [2, 3], it should be [1, 2].
