https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91457
--- Comment #16 from Martin Sebor <msebor at gcc dot gnu.org> ---
The warning code hasn't changed. What's different is that the MEM_REF that
-Warray-bounds doesn't handle isn't in the IL anymore. The
hppa2.0w-hp-hpux11.11 IL for the test case in comment #6 looks just like the
x86_64 IL and so the same warning is issued for both (see below). I don't know
what commit is behind the change.
$ cat pr91457.C && /build/hppa2.0w-hp-hpux11.11/gcc-svn/gcc/xgcc -B
/build/hppa2.0w-hp-hpux11.11/gcc-svn/gcc -S -O2 -Wall
-fdump-tree-dom3=/dev/stdout pr91457.C
struct A
{
char n, a[0];
A () { a[0] = 0; }
};
void f (struct A*);
void g (void)
{
struct A a;
f (&a);
}
pr91457.C: In function 'void g()':
pr91457.C:5:13: warning: array subscript 0 is above array bounds of 'char [0]'
[-Warray-bounds]
5 | A () { a[0] = 0; }
| ~~~^
pr91457.C:3:11: note: while referencing 'A::a'
3 | char n, a[0];
| ^
;; Function g (_Z1gv, funcdef_no=3, decl_uid=1937, cgraph_uid=4,
symbol_order=3)
;; 1 loops found
;;
;; Loop 0
;; header 0, latch 1
;; depth 0, outer -1
;; nodes: 0 1 2
;; 2 succs { 1 }
g ()
{
struct A a;
<bb 2> [local count: 1073741824]:
a ={v} {CLOBBER};
a.a[0] = 0;
f (&a);
a ={v} {CLOBBER};
return;
}
