From: Benno Lossin <benno.lossin@proton.me>
To: "Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Andreas Hindborg" <a.hindborg@samsung.com>,
"Alice Ryhl" <aliceryhl@google.com>,
"Martin Rodriguez Reboredo" <yakoyoku@gmail.com>
Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] rust: init: change the generated name of guard variables
Date: Wed, 03 Apr 2024 19:43:37 +0000 [thread overview]
Message-ID: <20240403194321.88716-1-benno.lossin@proton.me> (raw)
The initializers created by the `[try_][pin_]init!` macros utilize the
guard pattern to drop already initialized fields, when initialization
fails mid-way. These guards are generated to have the same name as the
field that they handle. To prevent namespacing issues when the field
name is the same as e.g. a constant name, add `__` as a prefix and
`_guard` as the suffix.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
---
rust/kernel/init/macros.rs | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index cb6e61b6c50b..93bf4c3080f9 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -250,7 +250,7 @@
//! // error type is `Infallible`) we will need to drop this field if there
//! // is an error later. This `DropGuard` will drop the field when it gets
//! // dropped and has not yet been forgotten.
-//! let t = unsafe {
+//! let __t_guard = unsafe {
//! ::pinned_init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).t))
//! };
//! // Expansion of `x: 0,`:
@@ -261,14 +261,14 @@
//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
//! }
//! // We again create a `DropGuard`.
-//! let x = unsafe {
+//! let __x_guard = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).x))
//! };
//! // Since initialization has successfully completed, we can now forget
//! // the guards. This is not `mem::forget`, since we only have
//! // `&DropGuard`.
-//! ::core::mem::forget(x);
-//! ::core::mem::forget(t);
+//! ::core::mem::forget(__x_guard);
+//! ::core::mem::forget(__t_guard);
//! // Here we use the type checker to ensure that every field has been
//! // initialized exactly once, since this is `if false` it will never get
//! // executed, but still type-checked.
@@ -461,16 +461,16 @@
//! {
//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
//! }
-//! let a = unsafe {
+//! let __a_guard = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).a))
//! };
//! let init = Bar::new(36);
//! unsafe { data.b(::core::addr_of_mut!((*slot).b), b)? };
-//! let b = unsafe {
+//! let __b_guard = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).b))
//! };
-//! ::core::mem::forget(b);
-//! ::core::mem::forget(a);
+//! ::core::mem::forget(__b_guard);
+//! ::core::mem::forget(__a_guard);
//! #[allow(unreachable_code, clippy::diverging_sub_expression)]
//! let _ = || {
//! unsafe {
@@ -1192,14 +1192,14 @@ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
// We use `paste!` to create new hygiene for `$field`.
::kernel::macros::paste! {
// SAFETY: We forget the guard later when initialization has succeeded.
- let [<$field>] = unsafe {
+ let [< __ $field _guard >] = unsafe {
$crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
};
$crate::__init_internal!(init_slot($use_data):
@data($data),
@slot($slot),
- @guards([<$field>], $($guards,)*),
+ @guards([< __ $field _guard >], $($guards,)*),
@munch_fields($($rest)*),
);
}
@@ -1223,14 +1223,14 @@ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
// We use `paste!` to create new hygiene for `$field`.
::kernel::macros::paste! {
// SAFETY: We forget the guard later when initialization has succeeded.
- let [<$field>] = unsafe {
+ let [< __ $field _guard >] = unsafe {
$crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
};
$crate::__init_internal!(init_slot():
@data($data),
@slot($slot),
- @guards([<$field>], $($guards,)*),
+ @guards([< __ $field _guard >], $($guards,)*),
@munch_fields($($rest)*),
);
}
@@ -1255,14 +1255,14 @@ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
// We use `paste!` to create new hygiene for `$field`.
::kernel::macros::paste! {
// SAFETY: We forget the guard later when initialization has succeeded.
- let [<$field>] = unsafe {
+ let [< __ $field _guard >] = unsafe {
$crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
};
$crate::__init_internal!(init_slot($($use_data)?):
@data($data),
@slot($slot),
- @guards([<$field>], $($guards,)*),
+ @guards([< __ $field _guard >], $($guards,)*),
@munch_fields($($rest)*),
);
}
base-commit: 9ffe2a730313f27cebd0859ea856247ac59c576c
--
2.44.0
next reply other threads:[~2024-04-03 19:43 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-03 19:43 Benno Lossin [this message]
2024-04-03 21:20 ` [PATCH] rust: init: change the generated name of guard variables Boqun Feng
2024-04-03 22:09 ` Benno Lossin
2024-04-03 22:38 ` Boqun Feng
2024-04-04 8:53 ` Benno Lossin
2024-04-17 15:06 ` Gary Guo
2024-04-17 15:20 ` Benno Lossin
2024-04-04 12:37 ` Alice Ryhl
2024-05-05 22:27 ` Miguel Ojeda
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