https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117377
Bug ID: 117377
Summary: Confusing -Wstringop-overflow warning with incorrect
declaration (pointer to array vs pointer to first
element)
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: sjames at gcc dot gnu.org
CC: eggert at cs dot ucla.edu, qing.zhao at oracle dot com
Blocks: 88443
Target Milestone: ---
This is only an issue with old gnulib, as is the case in GNU patch.
```
$ gcc -c utimens.i
utimens.c: In function ‘fdutimens’:
utimens.c:383:17: warning: ‘update_timespec’ accessing 16 bytes in a region of
size 8 [-Wstringop-overflow=]
383 | if (ts && update_timespec (&st, &ts))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
utimens.c:383:17: note: referencing argument 2 of type ‘struct timespec *[2]’
utimens.c:134:1: note: in a call to function ‘update_timespec’
134 | update_timespec (struct stat const *statbuf, struct timespec *ts[2])
| ^~~~~~~~~~~~~~~
utimens.c: In function ‘lutimens’:
utimens.c:596:17: warning: ‘update_timespec’ accessing 16 bytes in a region of
size 8 [-Wstringop-overflow=]
596 | if (ts && update_timespec (&st, &ts))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
utimens.c:596:17: note: referencing argument 2 of type ‘struct timespec *[2]’
utimens.c:134:1: note: in a call to function ‘update_timespec’
134 | update_timespec (struct stat const *statbuf, struct timespec *ts[2])
| ^~~~~~~~~~~~~~~
```
gnulib changed their code in
https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=a3a946f670718d0dee5a7425ad5ac0a29fb46ea1
(see https://lists.gnu.org/r/bug-tar/2021-04/msg00010.html), but I think the
warning doesn't do a great job of explaining the problem either. But I'm also
not sure what exactly we could do better, except maybe ignoring this construct.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88443
[Bug 88443] [meta-bug] bogus/missing -Wstringop-overflow warnings
