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, 29 insertions, 12 deletions

diff --git a/rust/Makefile b/rust/Makefile
index 4dcc2eff51cb..757974551359 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -117,6 +117,23 @@ syn-flags := \
     --extern quote \
     $(call cfgs-to-flags,$(syn-cfgs))
 
+pin_init_internal-cfgs := \
+    kernel
+
+pin_init_internal-flags := \
+    --extern proc_macro2 \
+    --extern quote \
+    --extern syn \
+    $(call cfgs-to-flags,$(pin_init_internal-cfgs))
+
+pin_init-cfgs := \
+    kernel
+
+pin_init-flags := \
+    --extern pin_init_internal \
+    --extern macros \
+    $(call cfgs-to-flags,$(pin_init-cfgs))
+
 # `rustdoc` did not save the target modifiers, thus workaround for
 # the time being (https://github.com/rust-lang/rust/issues/144521).
 rustdoc_modifiers_workaround := $(if $(call rustc-min-version,108800),-Cunsafe-allow-abi-mismatch=fixed-x18)
@@ -211,15 +228,15 @@ rustdoc-ffi: $(src)/ffi.rs rustdoc-core FORCE
 	+$(call if_changed,rustdoc)
 
 rustdoc-pin_init_internal: private rustdoc_host = yes
-rustdoc-pin_init_internal: private rustc_target_flags = --cfg kernel \
+rustdoc-pin_init_internal: private rustc_target_flags = $(pin_init_internal-flags) \
     --extern proc_macro --crate-type proc-macro
 rustdoc-pin_init_internal: $(src)/pin-init/internal/src/lib.rs \
-    rustdoc-clean FORCE
+    rustdoc-clean rustdoc-proc_macro2 rustdoc-quote rustdoc-syn FORCE
 	+$(call if_changed,rustdoc)
 
 rustdoc-pin_init: private rustdoc_host = yes
-rustdoc-pin_init: private rustc_target_flags = --extern pin_init_internal \
-    --extern macros --extern alloc --cfg kernel --cfg feature=\"alloc\"
+rustdoc-pin_init: private rustc_target_flags = $(pin_init-flags) \
+    --extern alloc --cfg feature=\"alloc\"
 rustdoc-pin_init: $(src)/pin-init/src/lib.rs rustdoc-pin_init_internal \
     rustdoc-macros FORCE
 	+$(call if_changed,rustdoc)
@@ -272,14 +289,14 @@ rusttestlib-macros: $(src)/macros/lib.rs \
     rusttestlib-proc_macro2 rusttestlib-quote rusttestlib-syn FORCE
 	+$(call if_changed,rustc_test_library)
 
-rusttestlib-pin_init_internal: private rustc_target_flags = --cfg kernel \
+rusttestlib-pin_init_internal: private rustc_target_flags = $(pin_init_internal-flags) \
     --extern proc_macro
 rusttestlib-pin_init_internal: private rustc_test_library_proc = yes
-rusttestlib-pin_init_internal: $(src)/pin-init/internal/src/lib.rs FORCE
+rusttestlib-pin_init_internal: $(src)/pin-init/internal/src/lib.rs \
+    rusttestlib-proc_macro2 rusttestlib-quote rusttestlib-syn FORCE
 	+$(call if_changed,rustc_test_library)
 
-rusttestlib-pin_init: private rustc_target_flags = --extern pin_init_internal \
-    --extern macros --cfg kernel
+rusttestlib-pin_init: private rustc_target_flags = $(pin_init-flags)
 rusttestlib-pin_init: $(src)/pin-init/src/lib.rs rusttestlib-macros \
     rusttestlib-pin_init_internal $(obj)/$(libpin_init_internal_name) FORCE
 	+$(call if_changed,rustc_test_library)
@@ -548,8 +565,9 @@ $(obj)/$(libmacros_name): $(src)/macros/lib.rs $(obj)/libproc_macro2.rlib \
     $(obj)/libquote.rlib $(obj)/libsyn.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacro)
 
-$(obj)/$(libpin_init_internal_name): private rustc_target_flags = --cfg kernel
-$(obj)/$(libpin_init_internal_name): $(src)/pin-init/internal/src/lib.rs FORCE
+$(obj)/$(libpin_init_internal_name): private rustc_target_flags = $(pin_init_internal-flags)
+$(obj)/$(libpin_init_internal_name): $(src)/pin-init/internal/src/lib.rs \
+    $(obj)/libproc_macro2.rlib $(obj)/libquote.rlib $(obj)/libsyn.rlib FORCE
 	+$(call if_changed_dep,rustc_procmacro)
 
 quiet_cmd_rustc_library = $(if $(skip_clippy),RUSTC,$(RUSTC_OR_CLIPPY_QUIET)) L $@
@@ -643,8 +661,7 @@ $(obj)/compiler_builtins.o: $(src)/compiler_builtins.rs $(obj)/core.o FORCE
 	+$(call if_changed_rule,rustc_library)
 
 $(obj)/pin_init.o: private skip_gendwarfksyms = 1
-$(obj)/pin_init.o: private rustc_target_flags = --extern pin_init_internal \
-    --extern macros --cfg kernel
+$(obj)/pin_init.o: private rustc_target_flags = $(pin_init-flags)
 $(obj)/pin_init.o: $(src)/pin-init/src/lib.rs $(obj)/compiler_builtins.o \
     $(obj)/$(libpin_init_internal_name) $(obj)/$(libmacros_name) FORCE
 	+$(call if_changed_rule,rustc_library)