In the `init!`/`pin_init!` macros, we rely on a trick that assigns never
(`!`) values to all mentioned fields in never-executed code to let the
compiler check that all fields have been initialized.
Currently we use `::core::panic!()` to produce this value, but before Rust
1.91.0, it creates outlined `panic_cold_explicit` functions which do not
get removed by the optimizer, thus leaving dead code behind in the binary.
This has been fixed by [1], which lands in Rust 1.91.0+, higher than the
kernel minimum version 1.85.0.
This causes ~200 dead `panic_cold_explicit` instances being included in the
binary, with ~90 of them from nova-core's usage of pin-init.
Work around the issue by using `loop {}` which creates the never value
without macro expansion or function call at all. All instances of
`panic_cold_explicit` outside libcore are removed by this change in my
kernel build.
Link: https://github.com/rust-lang/rust/pull/145304 [1]
Link: https://patch.msgid.link/20260508152950.833635-1-gary@kernel.org
Signed-off-by: Gary Guo <gary@garyguo.net>
Move `E` from type to trait impl block. This greatly shortens the
monomorphized type names. The `__pinned_init` function name is only
slightly shortened as it still encodes the `E` as part of `PinInit<T, E>`
in the symbol.
`T` cannot be moved to trait impl block otherwise it will start to conflict
with the `impl Init<T> for T` as Rust cannot deduce that there're no types
that fulfill `T: FnOnce(*mut T)`.
Link: https://patch.msgid.link/20260527-pin-init-sync-v1-6-e20335ed2501@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
The `__internal` module is for exposing internal items publicly to
procedural macros (pin-init-internal). Types that are crate-local only can
just have proper visibility and does not need to be in `__internal`.
The type name of `InitClosure` can often shows up in symbol names, this
reduces the length slightly.
Link: https://patch.msgid.link/20260527-pin-init-sync-v1-5-e20335ed2501@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
When using a macro with custom attributes in a `#[pin_data]` struct it
can mess up the generated code. The generated code needs nothing more than
the `#[cfg]` attribute, thus strip away all other attributes.
[ Rebased and updated to only include `#[cfg]` instead of both `#[cfg]` and
`#[doc]`; doc is not needed for the generated hidden items. - Gary ]
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260527-pin-init-sync-v1-1-e20335ed2501@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
Instead of projecting using pointer to a field project the full slot. This
further shifts the code generation from the initializer site to the struct
definition site, which means less code is generated overall.
It also makes the safety comment easier to justify, as now the projection
is done by the `#[pin_data]` macro which has full visibility of pinnedness
of fields.
The field alignment could also be checked on the `#[pin_data]` side;
however, since `init!()` macro works for other type of structs, we cannot
remove the alignment check from `init!`/`pin_init!` side anyway, so I opted
to still keep the alignment check in init.rs.
Signed-off-by: Gary Guo <gary@garyguo.net>
By projecting slots, the `pin_init!` and `init!` code path can be more
unified. This also reduces the amount of macro-generated code and shifts
them to the shared infrastructure.
Signed-off-by: Gary Guo <gary@garyguo.net>
The `InitData` and `PinData` traits do not need to exist, the inference
helpers could be inherent methods instead.
There is no risk for calling the wrong methods even when user defines it,
as inherent methods take priority over trait methods.
With this change, it unlocks the possibility of attaching additional bounds
to the method per type, which is not possible for trait methods.
Signed-off-by: Gary Guo <gary@garyguo.net>
Instead of projecting the created reference, simply create drop guards with
different marker types and have the `let_binding()` method of guards of
different marker produce different type instead.
This allows more flexible lifetime as this is now controlled by the guard.
This will be needed when implementing self-referential fields.
Signed-off-by: Gary Guo <gary@garyguo.net>
`InitializerKind::Code` is a special case where it does not initialize a
field, and thus generate no guard and accessors. Handle it earlier and make
the rest of the code more linear.
Signed-off-by: Gary Guo <gary@garyguo.net>
Currently, the `pin_init` library has an `Invariant` type alias, and it is
instantiated using `PhantomData`. Generated code from `pin_data` on the
other hand cannot access the crate-local type alias, so it generates
`PhantomData<fn(T) -> T>` directly. This is all very inconsistent, despite
the exact same use case of ensuring invariance.
Add `PhantomInvariant` and `PhantomInvariantLifetime` and switch all users
that need to express the concept of invariance to use these. They're
polyfills of unstable types in the same names in the Rust standard library.
Link: https://patch.msgid.link/20260512-pin-init-sync-v1-3-81963130dfbd@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
`handle_field` is currently a function, which precludes it from referencing
things in the scope of the parent function. Given that it's only called
once, inline its contents to the closure that invokes it instead, so it can
directly reference `struct_name` without having to pass in as argument.
Link: https://patch.msgid.link/20260512-pin-init-sync-v1-1-81963130dfbd@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
Tuples implement `FromIterator` since Rust 1.79. Remove the `collect_tuple`
polyfill now the MSRV is above 1.79.
To avoid over-identing the closure, I move the `Field` destructure from the
closure parameter to a let binding. This keeps the diff small.
Link: https://patch.msgid.link/20260501134445.3809731-1-gary@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
The `PhantomPinned` detection is just a lint, and is emitted as an error
because there is no `compile_warning!()` macro, and
`proc-macro-diagnostics` is not stable.
Use of `#[deprecated = ""]` attribute to approximate custom proc-macro
warnings. A new line is added before message for visual clarity.
An example warning with this trick looks like this:
warning: use of deprecated function `_::warn`:
The field `pin` of type `PhantomPinned` only has an effect if it has the `#[pin]` attribute
--> test.rs:9:5
|
9 | pin: marker::PhantomPinned,
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/pin-init/issues/51
Link: https://patch.msgid.link/20260428-pin-init-sync-v1-10-07f9bd3859fb@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
The pin-init crate has been licensed under `Apache-2.0 OR MIT` since the
beginning. I introduced in commit 071cedc84e ("rust: add derive macro for
`Zeroable`") `zeroable.rs` with incompatible GPL-2.0 SPDX identifier. The
file has not been modified by other authors, so relicense it under the
above license.
Signed-off-by: Benno Lossin <lossin@kernel.org>
[ Reworded commit message - Gary ]
Link: https://patch.msgid.link/20260428-pin-init-sync-v1-7-07f9bd3859fb@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
Improve impl_zeroable_option macro to handle generic impls for types
like `&T`, `&mut T`, `NonNull<T>`, and others (for which `Option<T>`
is guaranteed to be zeroable) with similar approach to
`impl_zeroable`.
Also, update old declarations to use generics e.g. `NonZeroU8` to
`NonZero<u8>`.
Signed-off-by: Mohamad Alsadhan <mo@sdhn.cc>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260428-pin-init-sync-v1-4-07f9bd3859fb@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
Place definitions and implementations (incl. macro invocations) of
the `Zeroable` trait first in the relevant section of `src/lib.rs`,
followed by the ZeroableOption trait and its implementations.
Rename `impl_non_zero_int_zeroable_option` to `impl_zeroable_option`
for consistency.
This commit should not introduce any functional changes.
Signed-off-by: Mohamad Alsadhan <mo@sdhn.cc>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260428-pin-init-sync-v1-3-07f9bd3859fb@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>
Gary Guo
Xiaobo LiuandGary Guo
Mirko AdzicandGary Guo
Martin KletzanderandGary Guo
Mohamad AlsadhanandGary Guo
Benno LossinandGary Guo