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charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 2E2551C000E X-Stat-Signature: s7s9r65uc49nc65zcfdikxb9i5r34dhn X-Rspam-User: X-HE-Tag: 1727104855-279908 X-HE-Meta: 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 UPvFi5Vw 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.087201, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 23.09.24 15:56, Alice Ryhl wrote: > On Sat, Sep 21, 2024 at 5:33=E2=80=AFPM Danilo Krummrich wrote: >> @@ -84,11 +92,18 @@ unsafe fn call( >> &self, >> ptr: Option>, >> layout: Layout, >> + old_layout: Layout, >> flags: Flags, >> ) -> Result, AllocError> { >> let size =3D aligned_size(layout); >> let ptr =3D match ptr { >> - Some(ptr) =3D> ptr.as_ptr(), >> + Some(ptr) =3D> { >> + if old_layout.size() =3D=3D 0 { >> + ptr::null() >> + } else { >> + ptr.as_ptr() >> + } >> + } >=20 > This is making Allocator work with zero-sized types, which deviates > from std. We should not do that without a reason. What is the reason? The global allocator doesn't support it, but the `Allocator` trait from std handles zero-sized allocations. For example, this code runs as expected: #![feature(allocator_api)] =20 use std::alloc::{self, Allocator, Layout}; =20 fn main() { let alloc: &dyn Allocator =3D &alloc::Global; let ptr =3D alloc.allocate(Layout::new::<()>()).unwrap().cast::= (); unsafe { alloc.deallocate(ptr, Layout::new::<()>()) }; } https://play.rust-lang.org/?version=3Dnightly&mode=3Ddebug&edition=3D2021&g= ist=3D0a2d12ee6dabf16f2ebd67cc6faa864e --- Cheers, Benno