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Subject: [Bug middle-end/99578] gcc-11 -Warray-bounds or -Wstringop-overread
 warning when accessing a pointer from integer literal
Date: Mon, 15 Mar 2021 20:24:09 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99578

--- Comment #9 from Martin Sebor <msebor at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #7)
> Note heuristically 0xe8ffc000 isn't likely such an offset from a NULL
> pointer object because the object would be quite large.
>=20
> The diagnostic could maybe also clarify that it assumes 0xe8ffc000 is an
> offsetted NULL pointer.

I can do that in stage 1 when I convert the warning to use the access_ref c=
lass
(that exposes this information).

A better solution we discussed with Jeff is to issue -Wnonnull when a member
access through a null pointer is first detected.  Using something like
__builtin_warning for that would help avoid false positives when this happe=
ns
early on (in the test case in comment #1 that's in EVRP).=