Merge tag 'rust-6.20-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Add '__rust_helper' annotation to the C helpers

     This is needed to inline these helpers into Rust code

   - Remove imports available via the prelude, treewide

     This was possible thanks to a new lint in Klint that Gary has
     implemented -- more Klint-related changes, including initial
     upstream support, are coming

   - Deduplicate pin-init flags

  'kernel' crate:

   - Add support for calling a function exactly once with the new
     'do_once_lite!' macro (and 'OnceLite' type)

     Based on this, add 'pr_*_once!' macros to print only once

   - Add 'impl_flags!' macro for defining common bitflags operations:

         impl_flags!(
             /// Represents multiple permissions.
             #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)]
             pub struct Permissions(u32);

             /// Represents a single permission.
             #[derive(Debug, Clone, Copy, PartialEq, Eq)]
             pub enum Permission {
                 /// Read permission.
                 Read = 1 << 0,

                 /// Write permission.
                 Write = 1 << 1,

                 /// Execute permission.
                 Execute = 1 << 2,
             }
         );

         let mut f: Permissions = Permission::Read | Permission::Write;
         assert!(f.contains(Permission::Read));
         assert!(!f.contains(Permission::Execute));

         f |= Permission::Execute;
         assert!(f.contains(Permission::Execute));

         let f2: Permissions = Permission::Write | Permission::Execute;
         assert!((f ^ f2).contains(Permission::Read));
         assert!(!(f ^ f2).contains(Permission::Write));

   - 'bug' module: support 'CONFIG_DEBUG_BUGVERBOSE_DETAILED' in the
     'warn_on!' macro in order to show the evaluated condition alongside
     the file path:

          ------------[ cut here ]------------
          WARNING: [val == 1] linux/samples/rust/rust_minimal.rs:27 at ...
          Modules linked in: rust_minimal(+)

   - Add safety module with 'unsafe_precondition_assert!' macro,
     currently a wrapper for 'debug_assert!', intended to mark the
     validation of safety preconditions where possible:

         /// # Safety
         ///
         /// The caller must ensure that `index` is less than `N`.
         unsafe fn set_unchecked(&mut self, index: usize, value: T) {
             unsafe_precondition_assert!(
                 index < N,
                 "set_unchecked() requires index ({index}) < N ({N})"
             );

             ...
         }

   - Add instructions to 'build_assert!' documentation requesting to
     always inline functions when used with function arguments

   - 'ptr' module: replace 'build_assert!' with a 'const' one

   - 'rbtree' module: reduce unsafe blocks on pointer derefs

   - 'transmute' module: implement 'FromBytes' and 'AsBytes' for
     inhabited ZSTs, and use it in Nova

   - More treewide replacements of 'c_str!' with C string literals

  'macros' crate:

   - Rewrite most procedural macros ('module!', 'concat_idents!',
     '#[export]', '#[vtable]', '#[kunit_tests]') to use the 'syn'
     parsing library which we introduced last cycle, with better
     diagnostics

     This also allows to support '#[cfg]' properly in the '#[vtable]'
     macro, to support arbitrary types in 'module!' macro (not just an
     identifier) and to remove several custom parsing helpers we had

   - Use 'quote!' from the recently vendored 'quote' library and remove
     our custom one

     The vendored one also allows us to avoid quoting '"' and '{}'
     inside the template anymore and editors can now highlight it. In
     addition, it improves robustness as it eliminates the need for
     string quoting and escaping

   - Use 'pin_init::zeroed()' to simplify KUnit code

  'pin-init' crate:

   - Rewrite all procedural macros ('[pin_]init!', '#[pin_data]',
     '#[pinned_drop]', 'derive([Maybe]Zeroable)') to use the 'syn'
     parsing library which we introduced last cycle, with better
     diagnostics

   - Implement 'InPlaceWrite' for '&'static mut MaybeUninit<T>'. This
     enables users to use external allocation mechanisms such as
     'static_cell'

   - Support tuple structs in 'derive([Maybe]Zeroable)'

   - Support attributes on fields in '[pin_]init!' (such as
     '#[cfg(...)]')

   - Add a '#[default_error(<type>)]' attribute to '[pin_]init!' to
     override the default error (when no '? Error' is specified)

   - Support packed structs in '[pin_]init!' with
     '#[disable_initialized_field_access]'

   - Remove 'try_[pin_]init!' in favor of merging their feature with
     '[pin_]init!'. Update the kernel's own 'try_[pin_]init!' macros to
     use the 'default_error' attribute

   - Correct 'T: Sized' bounds to 'T: ?Sized' in the generated
     'PinnedDrop' check by '#[pin_data]'

  Documentation:

   - Conclude the Rust experiment

  MAINTAINERS:

   - Add "RUST [RUST-ANALYZER]" entry for the rust-analyzer support.
     Tamir and Jesung will take care of it. They have both been active
     around it for a while. The new tree will flow through the Rust one

   - Add Gary as maintainer for "RUST [PIN-INIT]"

   - Update Boqun and Tamir emails to their kernel.org accounts

  And a few other cleanups and improvements"

* tag 'rust-6.20-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (59 commits)
  rust: safety: introduce `unsafe_precondition_assert!` macro
  rust: add `impl_flags!` macro for defining common bitflag operations
  rust: print: Add pr_*_once macros
  rust: bug: Support DEBUG_BUGVERBOSE_DETAILED option
  rust: print: Add support for calling a function exactly once
  rust: kbuild: deduplicate pin-init flags
  gpu: nova-core: remove imports available via prelude
  rust: clk: replace `kernel::c_str!` with C-Strings
  MAINTAINERS: Update my email address to @kernel.org
  rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
  rust: kunit: use `pin_init::zeroed` instead of custom null value
  rust: macros: rearrange `#[doc(hidden)]` in `module!` macro
  rust: macros: allow arbitrary types to be used in `module!` macro
  rust: macros: convert `#[kunit_tests]` macro to use `syn`
  rust: macros: convert `concat_idents!` to use `syn`
  rust: macros: convert `#[export]` to use `syn`
  rust: macros: use `quote!` for `module!` macro
  rust: macros: use `syn` to parse `module!` macro
  rust: macros: convert `#[vtable]` macro to use `syn`
  rust: macros: use `quote!` from vendored crate
  ...

1 files changed, 27 insertions, 21 deletions

diff --git a/rust/pin-init/internal/src/lib.rs b/rust/pin-init/internal/src/lib.rs
index 297b0129a5bf..08372c8f65f0 100644
--- a/rust/pin-init/internal/src/lib.rs
+++ b/rust/pin-init/internal/src/lib.rs
@@ -7,48 +7,54 @@
 //! `pin-init` proc macros.
 
 #![cfg_attr(not(RUSTC_LINT_REASONS_IS_STABLE), feature(lint_reasons))]
-// Allow `.into()` to convert
-// - `proc_macro2::TokenStream` into `proc_macro::TokenStream` in the user-space version.
-// - `proc_macro::TokenStream` into `proc_macro::TokenStream` in the kernel version.
-//   Clippy warns on this conversion, but it's required by the user-space version.
-//
-// Remove once we have `proc_macro2` in the kernel.
-#![allow(clippy::useless_conversion)]
 // Documentation is done in the pin-init crate instead.
 #![allow(missing_docs)]
 
 use proc_macro::TokenStream;
+use syn::parse_macro_input;
 
-#[cfg(kernel)]
-#[path = "../../../macros/quote.rs"]
-#[macro_use]
-#[cfg_attr(not(kernel), rustfmt::skip)]
-mod quote;
-#[cfg(not(kernel))]
-#[macro_use]
-extern crate quote;
+use crate::diagnostics::DiagCtxt;
 
-mod helpers;
+mod diagnostics;
+mod init;
 mod pin_data;
 mod pinned_drop;
 mod zeroable;
 
 #[proc_macro_attribute]
-pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream {
-    pin_data::pin_data(inner.into(), item.into()).into()
+pub fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
+    let args = parse_macro_input!(args);
+    let input = parse_macro_input!(input);
+    DiagCtxt::with(|dcx| pin_data::pin_data(args, input, dcx)).into()
 }
 
 #[proc_macro_attribute]
 pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
-    pinned_drop::pinned_drop(args.into(), input.into()).into()
+    let args = parse_macro_input!(args);
+    let input = parse_macro_input!(input);
+    DiagCtxt::with(|dcx| pinned_drop::pinned_drop(args, input, dcx)).into()
 }
 
 #[proc_macro_derive(Zeroable)]
 pub fn derive_zeroable(input: TokenStream) -> TokenStream {
-    zeroable::derive(input.into()).into()
+    let input = parse_macro_input!(input);
+    DiagCtxt::with(|dcx| zeroable::derive(input, dcx)).into()
 }
 
 #[proc_macro_derive(MaybeZeroable)]
 pub fn maybe_derive_zeroable(input: TokenStream) -> TokenStream {
-    zeroable::maybe_derive(input.into()).into()
+    let input = parse_macro_input!(input);
+    DiagCtxt::with(|dcx| zeroable::maybe_derive(input, dcx)).into()
+}
+#[proc_macro]
+pub fn init(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input);
+    DiagCtxt::with(|dcx| init::expand(input, Some("::core::convert::Infallible"), false, dcx))
+        .into()
+}
+
+#[proc_macro]
+pub fn pin_init(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input);
+    DiagCtxt::with(|dcx| init::expand(input, Some("::core::convert::Infallible"), true, dcx)).into()
 }