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From: "haoxintu at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/95354] GCC misuse "nonnull-attribute" option and can not
 detect it as UB as well
Date: Wed, 27 May 2020 11:43:12 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95354

--- Comment #5 from Haoxin Tu <haoxintu at gmail dot com> ---
(In reply to Jonathan Wakely from comment #4)
> (In reply to Haoxin Tu from comment #3)
> > I see. Are there any cases that can trigger the UB of nonnull-attribute=
? I
> > doubt the usage of =E2=80=9C-fsanitize=3Dnonnull-attribute=E2=80=9D in =
GCC...
>=20
> Yes, just use the attribute correctly.
>=20
> Using:
>=20
> __attribute__((nonnull)) void has_nonnull_argument(int *p) {=20
>      ;=20
> }
>=20
> will cause UBsan to diagnose it:
>=20
> nn.cc:7:25: runtime error: null pointer passed as argument 1, which is
> declared to never be null

Thanks, Jonathan, Got it ~=