linux-toradex.git/rust/Makefile, branch v6.19

rust: kbuild: Add -fdiagnostics-show-context to bindgen_skip_c_flags

2026-01-06T19:51:21+00:00

This got added with:

  7454048db27d ("kbuild: Enable GCC diagnostic context for value-tracking warnings")

but clang does not have this option, so avoid passing it to bindgen.

[ Details about what the option does are in the commit above. Nathan
  also expands on this:

    Right, this does look correct, as this option is specific to GCC
    for the purpose of exposing more information from GCC internals to
    the user for understanding diagnostics better.

  I checked that in Compiler Explorer GCC 15.2 doesn't have it, but GCC
  trunk indeed has. - Miguel ]

Fixes: 7454048db27d ("kbuild: Enable GCC diagnostic context for value-tracking warnings")
Signed-off-by: Siddhesh Poyarekar 
Link: https://patch.msgid.link/20251217224050.1186896-1-siddhesh@gotplt.org
[ Removed Cc: stable. Added title prefix. - Miguel ]
Signed-off-by: Miguel Ojeda

Merge tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2025-12-03T22:16:49+00:00

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

- Add support for 'syn'.

Syn is a parsing library for parsing a stream of Rust tokens into a
syntax tree of Rust source code.

Currently this library is geared toward use in Rust procedural
macros, but contains some APIs that may be useful more generally.

'syn' allows us to greatly simplify writing complex macros such as
'pin-init' (Benno has already prepared the 'syn'-based version). We
will use it in the 'macros' crate too.

'syn' is the most downloaded Rust crate (according to crates.io),
and it is also used by the Rust compiler itself. While the amount
of code is substantial, there should not be many updates needed for
these crates, and even if there are, they should not be too big,
e.g. +7k -3k lines across the 3 crates in the last year.

'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
I only modified their code to remove a third dependency
('unicode-ident') and to add the SPDX identifiers. The code can be
easily verified to exactly match upstream with the provided
scripts.

They are all licensed under "Apache-2.0 OR MIT", like the other
vendored 'alloc' crate we had for a while.

Please see the merge commit with the cover letter for more context.

- Allow 'unreachable_pub' and 'clippy::disallowed_names' for
doctests.

Examples (i.e. doctests) may want to do things like show public
items and use names such as 'foo'.

Nevertheless, we still try to keep examples as close to real code
as possible (this is part of why running Clippy on doctests is
important for us, e.g. for safety comments, which userspace Rust
does not support yet but we are stricter).

'kernel' crate:

- Replace our custom 'CStr' type with 'core::ffi::CStr'.

Using the standard library type reduces our custom code footprint,
and we retain needed custom functionality through an extension
trait and a new 'fmt!' macro which replaces the previous 'core'
import.

This started in 6.17 and continued in 6.18, and we finally land the
replacement now. This required quite some stamina from Tamir, who
split the changes in steps to prepare for the flag day change here.

- Replace 'kernel::c_str!' with C string literals.

C string literals were added in Rust 1.77, which produce '&CStr's
(the 'core' one), so now we can write:

c"hi"

instead of:

c_str!("hi")

- Add 'num' module for numerical features.

It includes the 'Integer' trait, implemented for all primitive
integer types.

It also includes the 'Bounded' integer wrapping type: an integer
value that requires only the 'N' least significant bits of the
wrapped type to be encoded:

// An unsigned 8-bit integer, of which only the 4 LSBs are used.
let v = Bounded::::new::<15>();
assert_eq!(v.get(), 15);

'Bounded' is useful to e.g. enforce guarantees when working with
bitfields that have an arbitrary number of bits.

Values can also be constructed from simple non-constant expressions
or, for more complex ones, validated at runtime.

'Bounded' also comes with comparison and arithmetic operations
(with both their backing type and other 'Bounded's with a
compatible backing type), casts to change the backing type,
extending/shrinking and infallible/fallible conversions from/to
primitives as applicable.

- 'rbtree' module: add immutable cursor ('Cursor').

It enables to use just an immutable tree reference where
appropriate. The existing fully-featured mutable cursor is renamed
to 'CursorMut'.

kallsyms:

- Fix wrong "big" kernel symbol type read from procfs.

'pin-init' crate:

- A couple minor fixes (Benno asked me to pick these patches up for
him this cycle).

Documentation:

- Quick Start guide: add Debian 13 (Trixie).

Debian Stable is now able to build Linux, since Debian 13 (released
2025-08-09) packages Rust 1.85.0, which is recent enough.

We are planning to propose that the minimum supported Rust version
in Linux follows Debian Stable releases, with Debian 13 being the
first one we upgrade to, i.e. Rust 1.85.

MAINTAINERS:

- Add entry for the new 'num' module.

- Remove Alex as Rust maintainer: he hasn't had the time to
contribute for a few years now, so it is a no-op change in
practice.

And a few other cleanups and improvements"

* tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
rust: macros: support `proc-macro2`, `quote` and `syn`
rust: syn: enable support in kbuild
rust: syn: add `README.md`
rust: syn: remove `unicode-ident` dependency
rust: syn: add SPDX License Identifiers
rust: syn: import crate
rust: quote: enable support in kbuild
rust: quote: add `README.md`
rust: quote: add SPDX License Identifiers
rust: quote: import crate
rust: proc-macro2: enable support in kbuild
rust: proc-macro2: add `README.md`
rust: proc-macro2: remove `unicode_ident` dependency
rust: proc-macro2: add SPDX License Identifiers
rust: proc-macro2: import crate
rust: kbuild: support using libraries in `rustc_procmacro`
rust: kbuild: support skipping flags in `rustc_test_library`
rust: kbuild: add proc macro library support
rust: kbuild: simplify `--cfg` handling
rust: kbuild: introduce `core-flags` and `core-skip_flags`
...

rust: macros: support `proc-macro2`, `quote` and `syn`

2025-11-24T16:15:50+00:00

One of the two main uses cases for adding `proc-macro2`, `quote` and
`syn` is the `macros` crates (and the other `pin-init`).

Thus add the support for the crates in `macros` already.

Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-21-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: syn: enable support in kbuild

2025-11-24T16:15:48+00:00

With all the new files in place and ready from the new crate, enable
the support for it in the build system.

Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-20-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: quote: enable support in kbuild

2025-11-24T16:15:43+00:00

With all the new files in place and ready from the new crate, enable
the support for it in the build system.

Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-15-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: proc-macro2: enable support in kbuild

2025-11-24T16:15:41+00:00

With all the new files in place and ready from the new crate, enable
the support for it in the build system.

`proc_macro_byte_character` and `proc_macro_c_str_literals` were
stabilized in Rust 1.79.0 [1] and were implemented earlier than our
minimum Rust version (1.78) [2][3]. Thus just enable them instead of using
the `cfg` that `proc-macro2` uses to emulate them in older compilers.

In addition, skip formatting for this vendored crate and take the chance
to add a comment mentioning this.

Link: https://github.com/rust-lang/rust/pull/123431 [1]
Link: https://github.com/rust-lang/rust/pull/112711 [2]
Link: https://github.com/rust-lang/rust/pull/119651 [3]
Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: kbuild: support using libraries in `rustc_procmacro`

2025-11-24T16:15:37+00:00

Proc macros such as `macros` and `pin-init` will need the ability to use
libraries such as `syn` (added later) in the `rustc_procmacro` command.

Thus add the support for it.

Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-6-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: kbuild: support skipping flags in `rustc_test_library`

2025-11-24T16:15:36+00:00

Crates like `quote` (added later) will need the ability to skip flags
in the `rustc_test_library` command.

Thus add the support for it.

Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: kbuild: add proc macro library support

2025-11-24T16:15:36+00:00

Add the proc macro library rule that produces `.rlib` files to be used
by proc macros such as the `macros` crate.

Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda

rust: kbuild: simplify `--cfg` handling

2025-11-24T16:15:35+00:00

We need to handle `cfg`s in both `rustc` and `rust-analyzer`, and in
future commits some of those contain double quotes, which complicates
things further.

Thus, instead of removing the `--cfg ` part in the rust-analyzer
generation script, have the `*-cfgs` variables contain just the actual
`cfg`, and use that to generate the actual flags in `*-flags`.

Reviewed-by: Alice Ryhl 
Reviewed-by: Gary Guo 
Tested-by: Gary Guo 
Tested-by: Jesung Yang 
Link: https://patch.msgid.link/20251124151837.2184382-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda