* [PATCH v3 01/12] rust: pin-init: internal: remove proc-macro[2] and quote workarounds
[not found] <20260112170919.1888584-1-gary@kernel.org>
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:07 ` [PATCH v3 02/12] rust: macros: use `quote!` from vendored crate Gary Guo
` (10 subsequent siblings)
11 siblings, 0 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Fiona Behrens, Tamir Duberstein
Cc: rust-for-linux, linux-kernel
From: Benno Lossin <lossin@kernel.org>
The kernel only had the `proc-macro` library available, whereas the
user-space version also used `proc-macro2` and `quote`. Now both are
available to the kernel, making it possible to remove the workarounds.
Clippy complains about unnecessary `.to_string()` as `proc-macro2`
provides additional `PartialEq` impl, so they are removed.
Signed-off-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/Makefile | 16 ++++++++++------
rust/pin-init/internal/src/helpers.rs | 7 ++-----
rust/pin-init/internal/src/lib.rs | 16 ----------------
rust/pin-init/internal/src/pin_data.rs | 18 ++++++------------
rust/pin-init/internal/src/pinned_drop.rs | 10 ++++------
rust/pin-init/internal/src/zeroable.rs | 6 ++----
scripts/generate_rust_analyzer.py | 2 +-
7 files changed, 25 insertions(+), 50 deletions(-)
diff --git a/rust/Makefile b/rust/Makefile
index 5d357dce1704d..96f0ac53ec0e8 100644
--- a/rust/Makefile
+++ b/rust/Makefile
@@ -212,9 +212,10 @@ rustdoc-ffi: $(src)/ffi.rs rustdoc-core FORCE
rustdoc-pin_init_internal: private rustdoc_host = yes
rustdoc-pin_init_internal: private rustc_target_flags = --cfg kernel \
- --extern proc_macro --crate-type proc-macro
+ --extern proc_macro --extern proc_macro2 --extern quote --extern syn \
+ --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
@@ -273,9 +274,10 @@ rusttestlib-macros: $(src)/macros/lib.rs \
+$(call if_changed,rustc_test_library)
rusttestlib-pin_init_internal: private rustc_target_flags = --cfg kernel \
- --extern proc_macro
+ --extern proc_macro --extern proc_macro2 --extern quote --extern syn
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 \
@@ -547,8 +549,10 @@ $(obj)/$(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)/$(libpin_init_internal_name): private rustc_target_flags = --cfg kernel \
+ --extern proc_macro2 --extern quote --extern syn
+$(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 $@
diff --git a/rust/pin-init/internal/src/helpers.rs b/rust/pin-init/internal/src/helpers.rs
index 236f989a50f2f..90f85eaa41231 100644
--- a/rust/pin-init/internal/src/helpers.rs
+++ b/rust/pin-init/internal/src/helpers.rs
@@ -1,9 +1,6 @@
// SPDX-License-Identifier: Apache-2.0 OR MIT
-#[cfg(not(kernel))]
-use proc_macro2 as proc_macro;
-
-use proc_macro::{TokenStream, TokenTree};
+use proc_macro2::{TokenStream, TokenTree};
/// Parsed generics.
///
@@ -101,7 +98,7 @@ pub(crate) fn parse_generics(input: TokenStream) -> (Generics, Vec<TokenTree>) {
1 => {
// Here depending on the token, it might be a generic variable name.
match tt.clone() {
- TokenTree::Ident(i) if at_start && i.to_string() == "const" => {
+ TokenTree::Ident(i) if at_start && i == "const" => {
let Some(name) = toks.next() else {
// Parsing error.
break;
diff --git a/rust/pin-init/internal/src/lib.rs b/rust/pin-init/internal/src/lib.rs
index 297b0129a5bfd..4c4dc639ce823 100644
--- a/rust/pin-init/internal/src/lib.rs
+++ b/rust/pin-init/internal/src/lib.rs
@@ -7,27 +7,11 @@
//! `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;
-#[cfg(kernel)]
-#[path = "../../../macros/quote.rs"]
-#[macro_use]
-#[cfg_attr(not(kernel), rustfmt::skip)]
-mod quote;
-#[cfg(not(kernel))]
-#[macro_use]
-extern crate quote;
-
mod helpers;
mod pin_data;
mod pinned_drop;
diff --git a/rust/pin-init/internal/src/pin_data.rs b/rust/pin-init/internal/src/pin_data.rs
index 87d4a7eb1d35e..86a53b37cc660 100644
--- a/rust/pin-init/internal/src/pin_data.rs
+++ b/rust/pin-init/internal/src/pin_data.rs
@@ -1,10 +1,8 @@
// SPDX-License-Identifier: Apache-2.0 OR MIT
-#[cfg(not(kernel))]
-use proc_macro2 as proc_macro;
-
use crate::helpers::{parse_generics, Generics};
-use proc_macro::{Group, Punct, Spacing, TokenStream, TokenTree};
+use proc_macro2::{Group, Punct, Spacing, TokenStream, TokenTree};
+use quote::quote;
pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
// This proc-macro only does some pre-parsing and then delegates the actual parsing to
@@ -28,7 +26,7 @@ pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
// The name of the struct with ty_generics.
let struct_name = rest
.iter()
- .skip_while(|tt| !matches!(tt, TokenTree::Ident(i) if i.to_string() == "struct"))
+ .skip_while(|tt| !matches!(tt, TokenTree::Ident(i) if i == "struct"))
.nth(1)
.and_then(|tt| match tt {
TokenTree::Ident(_) => {
@@ -65,7 +63,7 @@ pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
.into_iter()
.flat_map(|tt| {
// We ignore top level `struct` tokens, since they would emit a compile error.
- if matches!(&tt, TokenTree::Ident(i) if i.to_string() == "struct") {
+ if matches!(&tt, TokenTree::Ident(i) if i == "struct") {
vec![tt]
} else {
replace_self_and_deny_type_defs(&struct_name, tt, &mut errs)
@@ -98,11 +96,7 @@ fn replace_self_and_deny_type_defs(
) -> Vec<TokenTree> {
match tt {
TokenTree::Ident(ref i)
- if i.to_string() == "enum"
- || i.to_string() == "trait"
- || i.to_string() == "struct"
- || i.to_string() == "union"
- || i.to_string() == "impl" =>
+ if i == "enum" || i == "trait" || i == "struct" || i == "union" || i == "impl" =>
{
errs.extend(
format!(
@@ -119,7 +113,7 @@ fn replace_self_and_deny_type_defs(
);
vec![tt]
}
- TokenTree::Ident(i) if i.to_string() == "Self" => struct_name.clone(),
+ TokenTree::Ident(i) if i == "Self" => struct_name.clone(),
TokenTree::Literal(_) | TokenTree::Punct(_) | TokenTree::Ident(_) => vec![tt],
TokenTree::Group(g) => vec![TokenTree::Group(Group::new(
g.delimiter(),
diff --git a/rust/pin-init/internal/src/pinned_drop.rs b/rust/pin-init/internal/src/pinned_drop.rs
index c4ca7a70b726a..cf8cd1c429849 100644
--- a/rust/pin-init/internal/src/pinned_drop.rs
+++ b/rust/pin-init/internal/src/pinned_drop.rs
@@ -1,15 +1,13 @@
// SPDX-License-Identifier: Apache-2.0 OR MIT
-#[cfg(not(kernel))]
-use proc_macro2 as proc_macro;
-
-use proc_macro::{TokenStream, TokenTree};
+use proc_macro2::{TokenStream, TokenTree};
+use quote::quote;
pub(crate) fn pinned_drop(_args: TokenStream, input: TokenStream) -> TokenStream {
let mut toks = input.into_iter().collect::<Vec<_>>();
assert!(!toks.is_empty());
// Ensure that we have an `impl` item.
- assert!(matches!(&toks[0], TokenTree::Ident(i) if i.to_string() == "impl"));
+ assert!(matches!(&toks[0], TokenTree::Ident(i) if i == "impl"));
// Ensure that we are implementing `PinnedDrop`.
let mut nesting: usize = 0;
let mut pinned_drop_idx = None;
@@ -27,7 +25,7 @@ pub(crate) fn pinned_drop(_args: TokenStream, input: TokenStream) -> TokenStream
if i >= 1 && nesting == 0 {
// Found the end of the generics, this should be `PinnedDrop`.
assert!(
- matches!(tt, TokenTree::Ident(i) if i.to_string() == "PinnedDrop"),
+ matches!(tt, TokenTree::Ident(i) if i == "PinnedDrop"),
"expected 'PinnedDrop', found: '{tt:?}'"
);
pinned_drop_idx = Some(i);
diff --git a/rust/pin-init/internal/src/zeroable.rs b/rust/pin-init/internal/src/zeroable.rs
index e0ed3998445cf..d8a5ef3883f4b 100644
--- a/rust/pin-init/internal/src/zeroable.rs
+++ b/rust/pin-init/internal/src/zeroable.rs
@@ -1,10 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
-#[cfg(not(kernel))]
-use proc_macro2 as proc_macro;
-
use crate::helpers::{parse_generics, Generics};
-use proc_macro::{TokenStream, TokenTree};
+use proc_macro2::{TokenStream, TokenTree};
+use quote::quote;
pub(crate) fn parse_zeroable_derive_input(
input: TokenStream,
diff --git a/scripts/generate_rust_analyzer.py b/scripts/generate_rust_analyzer.py
index 147d0cc940681..d31d938886589 100755
--- a/scripts/generate_rust_analyzer.py
+++ b/scripts/generate_rust_analyzer.py
@@ -123,7 +123,7 @@ def generate_crates(srctree, objtree, sysroot_src, external_src, cfgs, core_edit
append_crate(
"pin_init_internal",
srctree / "rust" / "pin-init" / "internal" / "src" / "lib.rs",
- [],
+ ["std", "proc_macro", "proc_macro2", "quote", "syn"],
cfg=["kernel"],
is_proc_macro=True,
)
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v3 02/12] rust: macros: use `quote!` from vendored crate
[not found] <20260112170919.1888584-1-gary@kernel.org>
2026-01-12 17:07 ` [PATCH v3 01/12] rust: pin-init: internal: remove proc-macro[2] and quote workarounds Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-19 7:09 ` David Gow
2026-01-12 17:07 ` [PATCH v3 03/12] rust: macros: convert `#[vtable]` macro to use `syn` Gary Guo
` (9 subsequent siblings)
11 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Brendan Higgins, David Gow, Rae Moar,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Tamir Duberstein, Greg Kroah-Hartman,
José Expósito
Cc: rust-for-linux, linux-kernel, linux-kselftest, kunit-dev, linux-modules
From: Gary Guo <gary@garyguo.net>
With `quote` crate now vendored in the kernel, we can remove our custom
`quote!` macro implementation and just rely on that crate instead.
The `quote` crate uses types from the `proc-macro2` library so we also
update to use that, and perform conversion in the top-level lib.rs.
Clippy complains about unnecessary `.to_string()` as `proc-macro2`
provides additional `PartialEq` impl, so they are removed.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/concat_idents.rs | 2 +-
rust/macros/export.rs | 4 +-
rust/macros/fmt.rs | 4 +-
rust/macros/helpers.rs | 4 +-
rust/macros/kunit.rs | 5 +-
rust/macros/lib.rs | 21 ++--
rust/macros/module.rs | 6 +-
rust/macros/paste.rs | 2 +-
rust/macros/quote.rs | 182 -----------------------------------
rust/macros/vtable.rs | 7 +-
10 files changed, 32 insertions(+), 205 deletions(-)
delete mode 100644 rust/macros/quote.rs
diff --git a/rust/macros/concat_idents.rs b/rust/macros/concat_idents.rs
index 7e4b450f3a507..12cb231c3d715 100644
--- a/rust/macros/concat_idents.rs
+++ b/rust/macros/concat_idents.rs
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro::{token_stream, Ident, TokenStream, TokenTree};
+use proc_macro2::{token_stream, Ident, TokenStream, TokenTree};
use crate::helpers::expect_punct;
diff --git a/rust/macros/export.rs b/rust/macros/export.rs
index a08f6337d5c8d..92d9b30971929 100644
--- a/rust/macros/export.rs
+++ b/rust/macros/export.rs
@@ -1,7 +1,9 @@
// SPDX-License-Identifier: GPL-2.0
+use proc_macro2::TokenStream;
+use quote::quote;
+
use crate::helpers::function_name;
-use proc_macro::TokenStream;
/// Please see [`crate::export`] for documentation.
pub(crate) fn export(_attr: TokenStream, ts: TokenStream) -> TokenStream {
diff --git a/rust/macros/fmt.rs b/rust/macros/fmt.rs
index 2f4b9f6e22110..19f709262552b 100644
--- a/rust/macros/fmt.rs
+++ b/rust/macros/fmt.rs
@@ -1,8 +1,10 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro::{Ident, TokenStream, TokenTree};
use std::collections::BTreeSet;
+use proc_macro2::{Ident, TokenStream, TokenTree};
+use quote::quote_spanned;
+
/// Please see [`crate::fmt`] for documentation.
pub(crate) fn fmt(input: TokenStream) -> TokenStream {
let mut input = input.into_iter();
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index 365d7eb499c08..13fafaba12261 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro::{token_stream, Group, Ident, TokenStream, TokenTree};
+use proc_macro2::{token_stream, Group, Ident, TokenStream, TokenTree};
pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
if let Some(TokenTree::Ident(ident)) = it.next() {
@@ -86,7 +86,7 @@ pub(crate) fn function_name(input: TokenStream) -> Option<Ident> {
let mut input = input.into_iter();
while let Some(token) = input.next() {
match token {
- TokenTree::Ident(i) if i.to_string() == "fn" => {
+ TokenTree::Ident(i) if i == "fn" => {
if let Some(TokenTree::Ident(i)) = input.next() {
return Some(i);
}
diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index b395bb0536959..5cd6aa5eef07d 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -4,10 +4,11 @@
//!
//! Copyright (c) 2023 José Expósito <jose.exposito89@gmail.com>
-use proc_macro::{Delimiter, Group, TokenStream, TokenTree};
use std::collections::HashMap;
use std::fmt::Write;
+use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
+
pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
let attr = attr.to_string();
@@ -59,7 +60,7 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
}
_ => (),
},
- TokenTree::Ident(i) if i.to_string() == "fn" && attributes.contains_key("test") => {
+ TokenTree::Ident(i) if i == "fn" && attributes.contains_key("test") => {
if let Some(TokenTree::Ident(test_name)) = body_it.next() {
tests.push((test_name, attributes.remove("cfg").unwrap_or_default()))
}
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index b38002151871a..945982c21f703 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -11,8 +11,6 @@
// to avoid depending on the full `proc_macro_span` on Rust >= 1.88.0.
#![cfg_attr(not(CONFIG_RUSTC_HAS_SPAN_FILE), feature(proc_macro_span))]
-#[macro_use]
-mod quote;
mod concat_idents;
mod export;
mod fmt;
@@ -132,7 +130,7 @@
/// the kernel module.
#[proc_macro]
pub fn module(ts: TokenStream) -> TokenStream {
- module::module(ts)
+ module::module(ts.into()).into()
}
/// Declares or implements a vtable trait.
@@ -207,7 +205,7 @@ pub fn module(ts: TokenStream) -> TokenStream {
/// [`kernel::error::VTABLE_DEFAULT_ERROR`]: ../kernel/error/constant.VTABLE_DEFAULT_ERROR.html
#[proc_macro_attribute]
pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream {
- vtable::vtable(attr, ts)
+ vtable::vtable(attr.into(), ts.into()).into()
}
/// Export a function so that C code can call it via a header file.
@@ -230,7 +228,7 @@ pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream {
/// automatically exported with `EXPORT_SYMBOL_GPL`.
#[proc_macro_attribute]
pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream {
- export::export(attr, ts)
+ export::export(attr.into(), ts.into()).into()
}
/// Like [`core::format_args!`], but automatically wraps arguments in [`kernel::fmt::Adapter`].
@@ -248,7 +246,7 @@ pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream {
/// [`pr_info!`]: ../kernel/macro.pr_info.html
#[proc_macro]
pub fn fmt(input: TokenStream) -> TokenStream {
- fmt::fmt(input)
+ fmt::fmt(input.into()).into()
}
/// Concatenate two identifiers.
@@ -306,7 +304,7 @@ pub fn fmt(input: TokenStream) -> TokenStream {
/// ```
#[proc_macro]
pub fn concat_idents(ts: TokenStream) -> TokenStream {
- concat_idents::concat_idents(ts)
+ concat_idents::concat_idents(ts.into()).into()
}
/// Paste identifiers together.
@@ -444,9 +442,12 @@ pub fn concat_idents(ts: TokenStream) -> TokenStream {
/// [`paste`]: https://docs.rs/paste/
#[proc_macro]
pub fn paste(input: TokenStream) -> TokenStream {
- let mut tokens = input.into_iter().collect();
+ let mut tokens = proc_macro2::TokenStream::from(input).into_iter().collect();
paste::expand(&mut tokens);
- tokens.into_iter().collect()
+ tokens
+ .into_iter()
+ .collect::<proc_macro2::TokenStream>()
+ .into()
}
/// Registers a KUnit test suite and its test cases using a user-space like syntax.
@@ -473,5 +474,5 @@ pub fn paste(input: TokenStream) -> TokenStream {
/// ```
#[proc_macro_attribute]
pub fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
- kunit::kunit_tests(attr, ts)
+ kunit::kunit_tests(attr.into(), ts.into()).into()
}
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 80cb9b16f5aaf..b855a2b586e18 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -1,9 +1,11 @@
// SPDX-License-Identifier: GPL-2.0
-use crate::helpers::*;
-use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
use std::fmt::Write;
+use proc_macro2::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
+
+use crate::helpers::*;
+
fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {
let group = expect_group(it);
assert_eq!(group.delimiter(), Delimiter::Bracket);
diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs
index cce712d19855b..2181e312a7d32 100644
--- a/rust/macros/paste.rs
+++ b/rust/macros/paste.rs
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree};
+use proc_macro2::{Delimiter, Group, Ident, Spacing, Span, TokenTree};
fn concat_helper(tokens: &[TokenTree]) -> Vec<(String, Span)> {
let mut tokens = tokens.iter();
diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs
deleted file mode 100644
index ddfc21577539c..0000000000000
--- a/rust/macros/quote.rs
+++ /dev/null
@@ -1,182 +0,0 @@
-// SPDX-License-Identifier: Apache-2.0 OR MIT
-
-use proc_macro::{TokenStream, TokenTree};
-
-pub(crate) trait ToTokens {
- fn to_tokens(&self, tokens: &mut TokenStream);
-}
-
-impl<T: ToTokens> ToTokens for Option<T> {
- fn to_tokens(&self, tokens: &mut TokenStream) {
- if let Some(v) = self {
- v.to_tokens(tokens);
- }
- }
-}
-
-impl ToTokens for proc_macro::Group {
- fn to_tokens(&self, tokens: &mut TokenStream) {
- tokens.extend([TokenTree::from(self.clone())]);
- }
-}
-
-impl ToTokens for proc_macro::Ident {
- fn to_tokens(&self, tokens: &mut TokenStream) {
- tokens.extend([TokenTree::from(self.clone())]);
- }
-}
-
-impl ToTokens for TokenTree {
- fn to_tokens(&self, tokens: &mut TokenStream) {
- tokens.extend([self.clone()]);
- }
-}
-
-impl ToTokens for TokenStream {
- fn to_tokens(&self, tokens: &mut TokenStream) {
- tokens.extend(self.clone());
- }
-}
-
-/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with
-/// the given span.
-///
-/// This is a similar to the
-/// [`quote_spanned!`](https://docs.rs/quote/latest/quote/macro.quote_spanned.html) macro from the
-/// `quote` crate but provides only just enough functionality needed by the current `macros` crate.
-macro_rules! quote_spanned {
- ($span:expr => $($tt:tt)*) => {{
- let mut tokens = ::proc_macro::TokenStream::new();
- {
- #[allow(unused_variables)]
- let span = $span;
- quote_spanned!(@proc tokens span $($tt)*);
- }
- tokens
- }};
- (@proc $v:ident $span:ident) => {};
- (@proc $v:ident $span:ident #$id:ident $($tt:tt)*) => {
- $crate::quote::ToTokens::to_tokens(&$id, &mut $v);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident #(#$id:ident)* $($tt:tt)*) => {
- for token in $id {
- $crate::quote::ToTokens::to_tokens(&token, &mut $v);
- }
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident ( $($inner:tt)* ) $($tt:tt)*) => {
- #[allow(unused_mut)]
- let mut tokens = ::proc_macro::TokenStream::new();
- quote_spanned!(@proc tokens $span $($inner)*);
- $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
- ::proc_macro::Delimiter::Parenthesis,
- tokens,
- ))]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident [ $($inner:tt)* ] $($tt:tt)*) => {
- let mut tokens = ::proc_macro::TokenStream::new();
- quote_spanned!(@proc tokens $span $($inner)*);
- $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
- ::proc_macro::Delimiter::Bracket,
- tokens,
- ))]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident { $($inner:tt)* } $($tt:tt)*) => {
- let mut tokens = ::proc_macro::TokenStream::new();
- quote_spanned!(@proc tokens $span $($inner)*);
- $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
- ::proc_macro::Delimiter::Brace,
- tokens,
- ))]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident :: $($tt:tt)*) => {
- $v.extend([::proc_macro::Spacing::Joint, ::proc_macro::Spacing::Alone].map(|spacing| {
- ::proc_macro::TokenTree::Punct(::proc_macro::Punct::new(':', spacing))
- }));
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident : $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident , $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(',', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident @ $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('@', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident ! $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('!', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident ; $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident + $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('+', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident = $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('=', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident # $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('#', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident & $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Punct(
- ::proc_macro::Punct::new('&', ::proc_macro::Spacing::Alone),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident _ $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Ident(
- ::proc_macro::Ident::new("_", $span),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
- (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => {
- $v.extend([::proc_macro::TokenTree::Ident(
- ::proc_macro::Ident::new(stringify!($id), $span),
- )]);
- quote_spanned!(@proc $v $span $($tt)*);
- };
-}
-
-/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with
-/// mixed site span ([`Span::mixed_site()`]).
-///
-/// This is a similar to the [`quote!`](https://docs.rs/quote/latest/quote/macro.quote.html) macro
-/// from the `quote` crate but provides only just enough functionality needed by the current
-/// `macros` crate.
-///
-/// [`Span::mixed_site()`]: https://doc.rust-lang.org/proc_macro/struct.Span.html#method.mixed_site
-macro_rules! quote {
- ($($tt:tt)*) => {
- quote_spanned!(::proc_macro::Span::mixed_site() => $($tt)*)
- }
-}
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
index ee06044fcd4f3..a67d1cc81a2d3 100644
--- a/rust/macros/vtable.rs
+++ b/rust/macros/vtable.rs
@@ -1,9 +1,10 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro::{Delimiter, Group, TokenStream, TokenTree};
use std::collections::HashSet;
use std::fmt::Write;
+use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
+
pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
let mut tokens: Vec<_> = ts.into_iter().collect();
@@ -31,7 +32,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
let mut consts = HashSet::new();
while let Some(token) = body_it.next() {
match token {
- TokenTree::Ident(ident) if ident.to_string() == "fn" => {
+ TokenTree::Ident(ident) if ident == "fn" => {
let fn_name = match body_it.next() {
Some(TokenTree::Ident(ident)) => ident.to_string(),
// Possibly we've encountered a fn pointer type instead.
@@ -39,7 +40,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
};
functions.push(fn_name);
}
- TokenTree::Ident(ident) if ident.to_string() == "const" => {
+ TokenTree::Ident(ident) if ident == "const" => {
let const_name = match body_it.next() {
Some(TokenTree::Ident(ident)) => ident.to_string(),
// Possibly we've encountered an inline const block instead.
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v3 02/12] rust: macros: use `quote!` from vendored crate
2026-01-12 17:07 ` [PATCH v3 02/12] rust: macros: use `quote!` from vendored crate Gary Guo
@ 2026-01-19 7:09 ` David Gow
0 siblings, 0 replies; 25+ messages in thread
From: David Gow @ 2026-01-19 7:09 UTC (permalink / raw)
To: Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Brendan Higgins, Rae Moar, Luis Chamberlain, Petr Pavlu,
Daniel Gomez, Sami Tolvanen, Aaron Tomlin, Tamir Duberstein,
Greg Kroah-Hartman, José Expósito, rust-for-linux,
linux-kernel, linux-kselftest, kunit-dev, linux-modules
[-- Attachment #1: Type: text/plain, Size: 18529 bytes --]
On Tue, 13 Jan 2026 at 01:11, Gary Guo <gary@kernel.org> wrote:
>
> From: Gary Guo <gary@garyguo.net>
>
> With `quote` crate now vendored in the kernel, we can remove our custom
> `quote!` macro implementation and just rely on that crate instead.
>
> The `quote` crate uses types from the `proc-macro2` library so we also
> update to use that, and perform conversion in the top-level lib.rs.
>
> Clippy complains about unnecessary `.to_string()` as `proc-macro2`
> provides additional `PartialEq` impl, so they are removed.
>
> Reviewed-by: Tamir Duberstein <tamird@gmail.com>
> Reviewed-by: Benno Lossin <lossin@kernel.org>
> Signed-off-by: Gary Guo <gary@garyguo.net>
> ---
Acked-by: David Gow <davidgow@google.com> # for kunit
Cheers,
-- David
-- David
> rust/macros/concat_idents.rs | 2 +-
> rust/macros/export.rs | 4 +-
> rust/macros/fmt.rs | 4 +-
> rust/macros/helpers.rs | 4 +-
> rust/macros/kunit.rs | 5 +-
> rust/macros/lib.rs | 21 ++--
> rust/macros/module.rs | 6 +-
> rust/macros/paste.rs | 2 +-
> rust/macros/quote.rs | 182 -----------------------------------
> rust/macros/vtable.rs | 7 +-
> 10 files changed, 32 insertions(+), 205 deletions(-)
> delete mode 100644 rust/macros/quote.rs
>
> diff --git a/rust/macros/concat_idents.rs b/rust/macros/concat_idents.rs
> index 7e4b450f3a507..12cb231c3d715 100644
> --- a/rust/macros/concat_idents.rs
> +++ b/rust/macros/concat_idents.rs
> @@ -1,6 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
>
> -use proc_macro::{token_stream, Ident, TokenStream, TokenTree};
> +use proc_macro2::{token_stream, Ident, TokenStream, TokenTree};
>
> use crate::helpers::expect_punct;
>
> diff --git a/rust/macros/export.rs b/rust/macros/export.rs
> index a08f6337d5c8d..92d9b30971929 100644
> --- a/rust/macros/export.rs
> +++ b/rust/macros/export.rs
> @@ -1,7 +1,9 @@
> // SPDX-License-Identifier: GPL-2.0
>
> +use proc_macro2::TokenStream;
> +use quote::quote;
> +
> use crate::helpers::function_name;
> -use proc_macro::TokenStream;
>
> /// Please see [`crate::export`] for documentation.
> pub(crate) fn export(_attr: TokenStream, ts: TokenStream) -> TokenStream {
> diff --git a/rust/macros/fmt.rs b/rust/macros/fmt.rs
> index 2f4b9f6e22110..19f709262552b 100644
> --- a/rust/macros/fmt.rs
> +++ b/rust/macros/fmt.rs
> @@ -1,8 +1,10 @@
> // SPDX-License-Identifier: GPL-2.0
>
> -use proc_macro::{Ident, TokenStream, TokenTree};
> use std::collections::BTreeSet;
>
> +use proc_macro2::{Ident, TokenStream, TokenTree};
> +use quote::quote_spanned;
> +
> /// Please see [`crate::fmt`] for documentation.
> pub(crate) fn fmt(input: TokenStream) -> TokenStream {
> let mut input = input.into_iter();
> diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
> index 365d7eb499c08..13fafaba12261 100644
> --- a/rust/macros/helpers.rs
> +++ b/rust/macros/helpers.rs
> @@ -1,6 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
>
> -use proc_macro::{token_stream, Group, Ident, TokenStream, TokenTree};
> +use proc_macro2::{token_stream, Group, Ident, TokenStream, TokenTree};
>
> pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
> if let Some(TokenTree::Ident(ident)) = it.next() {
> @@ -86,7 +86,7 @@ pub(crate) fn function_name(input: TokenStream) -> Option<Ident> {
> let mut input = input.into_iter();
> while let Some(token) = input.next() {
> match token {
> - TokenTree::Ident(i) if i.to_string() == "fn" => {
> + TokenTree::Ident(i) if i == "fn" => {
> if let Some(TokenTree::Ident(i)) = input.next() {
> return Some(i);
> }
> diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
> index b395bb0536959..5cd6aa5eef07d 100644
> --- a/rust/macros/kunit.rs
> +++ b/rust/macros/kunit.rs
> @@ -4,10 +4,11 @@
> //!
> //! Copyright (c) 2023 José Expósito <jose.exposito89@gmail.com>
>
> -use proc_macro::{Delimiter, Group, TokenStream, TokenTree};
> use std::collections::HashMap;
> use std::fmt::Write;
>
> +use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
> +
> pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
> let attr = attr.to_string();
>
> @@ -59,7 +60,7 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
> }
> _ => (),
> },
> - TokenTree::Ident(i) if i.to_string() == "fn" && attributes.contains_key("test") => {
> + TokenTree::Ident(i) if i == "fn" && attributes.contains_key("test") => {
> if let Some(TokenTree::Ident(test_name)) = body_it.next() {
> tests.push((test_name, attributes.remove("cfg").unwrap_or_default()))
> }
> diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
> index b38002151871a..945982c21f703 100644
> --- a/rust/macros/lib.rs
> +++ b/rust/macros/lib.rs
> @@ -11,8 +11,6 @@
> // to avoid depending on the full `proc_macro_span` on Rust >= 1.88.0.
> #![cfg_attr(not(CONFIG_RUSTC_HAS_SPAN_FILE), feature(proc_macro_span))]
>
> -#[macro_use]
> -mod quote;
> mod concat_idents;
> mod export;
> mod fmt;
> @@ -132,7 +130,7 @@
> /// the kernel module.
> #[proc_macro]
> pub fn module(ts: TokenStream) -> TokenStream {
> - module::module(ts)
> + module::module(ts.into()).into()
> }
>
> /// Declares or implements a vtable trait.
> @@ -207,7 +205,7 @@ pub fn module(ts: TokenStream) -> TokenStream {
> /// [`kernel::error::VTABLE_DEFAULT_ERROR`]: ../kernel/error/constant.VTABLE_DEFAULT_ERROR.html
> #[proc_macro_attribute]
> pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream {
> - vtable::vtable(attr, ts)
> + vtable::vtable(attr.into(), ts.into()).into()
> }
>
> /// Export a function so that C code can call it via a header file.
> @@ -230,7 +228,7 @@ pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream {
> /// automatically exported with `EXPORT_SYMBOL_GPL`.
> #[proc_macro_attribute]
> pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream {
> - export::export(attr, ts)
> + export::export(attr.into(), ts.into()).into()
> }
>
> /// Like [`core::format_args!`], but automatically wraps arguments in [`kernel::fmt::Adapter`].
> @@ -248,7 +246,7 @@ pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream {
> /// [`pr_info!`]: ../kernel/macro.pr_info.html
> #[proc_macro]
> pub fn fmt(input: TokenStream) -> TokenStream {
> - fmt::fmt(input)
> + fmt::fmt(input.into()).into()
> }
>
> /// Concatenate two identifiers.
> @@ -306,7 +304,7 @@ pub fn fmt(input: TokenStream) -> TokenStream {
> /// ```
> #[proc_macro]
> pub fn concat_idents(ts: TokenStream) -> TokenStream {
> - concat_idents::concat_idents(ts)
> + concat_idents::concat_idents(ts.into()).into()
> }
>
> /// Paste identifiers together.
> @@ -444,9 +442,12 @@ pub fn concat_idents(ts: TokenStream) -> TokenStream {
> /// [`paste`]: https://docs.rs/paste/
> #[proc_macro]
> pub fn paste(input: TokenStream) -> TokenStream {
> - let mut tokens = input.into_iter().collect();
> + let mut tokens = proc_macro2::TokenStream::from(input).into_iter().collect();
> paste::expand(&mut tokens);
> - tokens.into_iter().collect()
> + tokens
> + .into_iter()
> + .collect::<proc_macro2::TokenStream>()
> + .into()
> }
>
> /// Registers a KUnit test suite and its test cases using a user-space like syntax.
> @@ -473,5 +474,5 @@ pub fn paste(input: TokenStream) -> TokenStream {
> /// ```
> #[proc_macro_attribute]
> pub fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
> - kunit::kunit_tests(attr, ts)
> + kunit::kunit_tests(attr.into(), ts.into()).into()
> }
> diff --git a/rust/macros/module.rs b/rust/macros/module.rs
> index 80cb9b16f5aaf..b855a2b586e18 100644
> --- a/rust/macros/module.rs
> +++ b/rust/macros/module.rs
> @@ -1,9 +1,11 @@
> // SPDX-License-Identifier: GPL-2.0
>
> -use crate::helpers::*;
> -use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
> use std::fmt::Write;
>
> +use proc_macro2::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
> +
> +use crate::helpers::*;
> +
> fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {
> let group = expect_group(it);
> assert_eq!(group.delimiter(), Delimiter::Bracket);
> diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs
> index cce712d19855b..2181e312a7d32 100644
> --- a/rust/macros/paste.rs
> +++ b/rust/macros/paste.rs
> @@ -1,6 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0
>
> -use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree};
> +use proc_macro2::{Delimiter, Group, Ident, Spacing, Span, TokenTree};
>
> fn concat_helper(tokens: &[TokenTree]) -> Vec<(String, Span)> {
> let mut tokens = tokens.iter();
> diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs
> deleted file mode 100644
> index ddfc21577539c..0000000000000
> --- a/rust/macros/quote.rs
> +++ /dev/null
> @@ -1,182 +0,0 @@
> -// SPDX-License-Identifier: Apache-2.0 OR MIT
> -
> -use proc_macro::{TokenStream, TokenTree};
> -
> -pub(crate) trait ToTokens {
> - fn to_tokens(&self, tokens: &mut TokenStream);
> -}
> -
> -impl<T: ToTokens> ToTokens for Option<T> {
> - fn to_tokens(&self, tokens: &mut TokenStream) {
> - if let Some(v) = self {
> - v.to_tokens(tokens);
> - }
> - }
> -}
> -
> -impl ToTokens for proc_macro::Group {
> - fn to_tokens(&self, tokens: &mut TokenStream) {
> - tokens.extend([TokenTree::from(self.clone())]);
> - }
> -}
> -
> -impl ToTokens for proc_macro::Ident {
> - fn to_tokens(&self, tokens: &mut TokenStream) {
> - tokens.extend([TokenTree::from(self.clone())]);
> - }
> -}
> -
> -impl ToTokens for TokenTree {
> - fn to_tokens(&self, tokens: &mut TokenStream) {
> - tokens.extend([self.clone()]);
> - }
> -}
> -
> -impl ToTokens for TokenStream {
> - fn to_tokens(&self, tokens: &mut TokenStream) {
> - tokens.extend(self.clone());
> - }
> -}
> -
> -/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with
> -/// the given span.
> -///
> -/// This is a similar to the
> -/// [`quote_spanned!`](https://docs.rs/quote/latest/quote/macro.quote_spanned.html) macro from the
> -/// `quote` crate but provides only just enough functionality needed by the current `macros` crate.
> -macro_rules! quote_spanned {
> - ($span:expr => $($tt:tt)*) => {{
> - let mut tokens = ::proc_macro::TokenStream::new();
> - {
> - #[allow(unused_variables)]
> - let span = $span;
> - quote_spanned!(@proc tokens span $($tt)*);
> - }
> - tokens
> - }};
> - (@proc $v:ident $span:ident) => {};
> - (@proc $v:ident $span:ident #$id:ident $($tt:tt)*) => {
> - $crate::quote::ToTokens::to_tokens(&$id, &mut $v);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident #(#$id:ident)* $($tt:tt)*) => {
> - for token in $id {
> - $crate::quote::ToTokens::to_tokens(&token, &mut $v);
> - }
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident ( $($inner:tt)* ) $($tt:tt)*) => {
> - #[allow(unused_mut)]
> - let mut tokens = ::proc_macro::TokenStream::new();
> - quote_spanned!(@proc tokens $span $($inner)*);
> - $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
> - ::proc_macro::Delimiter::Parenthesis,
> - tokens,
> - ))]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident [ $($inner:tt)* ] $($tt:tt)*) => {
> - let mut tokens = ::proc_macro::TokenStream::new();
> - quote_spanned!(@proc tokens $span $($inner)*);
> - $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
> - ::proc_macro::Delimiter::Bracket,
> - tokens,
> - ))]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident { $($inner:tt)* } $($tt:tt)*) => {
> - let mut tokens = ::proc_macro::TokenStream::new();
> - quote_spanned!(@proc tokens $span $($inner)*);
> - $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new(
> - ::proc_macro::Delimiter::Brace,
> - tokens,
> - ))]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident :: $($tt:tt)*) => {
> - $v.extend([::proc_macro::Spacing::Joint, ::proc_macro::Spacing::Alone].map(|spacing| {
> - ::proc_macro::TokenTree::Punct(::proc_macro::Punct::new(':', spacing))
> - }));
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident : $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident , $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new(',', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident @ $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new('@', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident ! $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new('!', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident ; $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident + $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new('+', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident = $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new('=', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident # $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new('#', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident & $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Punct(
> - ::proc_macro::Punct::new('&', ::proc_macro::Spacing::Alone),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident _ $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Ident(
> - ::proc_macro::Ident::new("_", $span),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> - (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => {
> - $v.extend([::proc_macro::TokenTree::Ident(
> - ::proc_macro::Ident::new(stringify!($id), $span),
> - )]);
> - quote_spanned!(@proc $v $span $($tt)*);
> - };
> -}
> -
> -/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with
> -/// mixed site span ([`Span::mixed_site()`]).
> -///
> -/// This is a similar to the [`quote!`](https://docs.rs/quote/latest/quote/macro.quote.html) macro
> -/// from the `quote` crate but provides only just enough functionality needed by the current
> -/// `macros` crate.
> -///
> -/// [`Span::mixed_site()`]: https://doc.rust-lang.org/proc_macro/struct.Span.html#method.mixed_site
> -macro_rules! quote {
> - ($($tt:tt)*) => {
> - quote_spanned!(::proc_macro::Span::mixed_site() => $($tt)*)
> - }
> -}
> diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
> index ee06044fcd4f3..a67d1cc81a2d3 100644
> --- a/rust/macros/vtable.rs
> +++ b/rust/macros/vtable.rs
> @@ -1,9 +1,10 @@
> // SPDX-License-Identifier: GPL-2.0
>
> -use proc_macro::{Delimiter, Group, TokenStream, TokenTree};
> use std::collections::HashSet;
> use std::fmt::Write;
>
> +use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
> +
> pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
> let mut tokens: Vec<_> = ts.into_iter().collect();
>
> @@ -31,7 +32,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
> let mut consts = HashSet::new();
> while let Some(token) = body_it.next() {
> match token {
> - TokenTree::Ident(ident) if ident.to_string() == "fn" => {
> + TokenTree::Ident(ident) if ident == "fn" => {
> let fn_name = match body_it.next() {
> Some(TokenTree::Ident(ident)) => ident.to_string(),
> // Possibly we've encountered a fn pointer type instead.
> @@ -39,7 +40,7 @@ pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
> };
> functions.push(fn_name);
> }
> - TokenTree::Ident(ident) if ident.to_string() == "const" => {
> + TokenTree::Ident(ident) if ident == "const" => {
> let const_name = match body_it.next() {
> Some(TokenTree::Ident(ident)) => ident.to_string(),
> // Possibly we've encountered an inline const block instead.
> --
> 2.51.2
>
[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 5281 bytes --]
^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v3 03/12] rust: macros: convert `#[vtable]` macro to use `syn`
[not found] <20260112170919.1888584-1-gary@kernel.org>
2026-01-12 17:07 ` [PATCH v3 01/12] rust: pin-init: internal: remove proc-macro[2] and quote workarounds Gary Guo
2026-01-12 17:07 ` [PATCH v3 02/12] rust: macros: use `quote!` from vendored crate Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-17 19:25 ` Benno Lossin
2026-01-12 17:07 ` [PATCH v3 04/12] rust: macros: use `syn` to parse `module!` macro Gary Guo
` (8 subsequent siblings)
11 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Tamir Duberstein, José Expósito
Cc: rust-for-linux, Guilherme Giacomo Simoes, linux-kernel
From: Gary Guo <gary@garyguo.net>
`#[vtable]` is converted to use syn. This is more robust than the
previous heuristic-based searching of defined methods and functions.
When doing so, the trait and impl are split into two code paths as the
types are distinct when parsed by `syn`.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/lib.rs | 9 ++-
rust/macros/vtable.rs | 169 +++++++++++++++++++++++-------------------
2 files changed, 98 insertions(+), 80 deletions(-)
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 945982c21f703..9955c04dbaae3 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -22,6 +22,8 @@
use proc_macro::TokenStream;
+use syn::parse_macro_input;
+
/// Declares a kernel module.
///
/// The `type` argument should be a type which implements the [`Module`]
@@ -204,8 +206,11 @@ pub fn module(ts: TokenStream) -> TokenStream {
///
/// [`kernel::error::VTABLE_DEFAULT_ERROR`]: ../kernel/error/constant.VTABLE_DEFAULT_ERROR.html
#[proc_macro_attribute]
-pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream {
- vtable::vtable(attr.into(), ts.into()).into()
+pub fn vtable(attr: TokenStream, input: TokenStream) -> TokenStream {
+ parse_macro_input!(attr as syn::parse::Nothing);
+ vtable::vtable(parse_macro_input!(input))
+ .unwrap_or_else(|e| e.into_compile_error())
+ .into()
}
/// Export a function so that C code can call it via a header file.
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
index a67d1cc81a2d3..72ae0a1816a04 100644
--- a/rust/macros/vtable.rs
+++ b/rust/macros/vtable.rs
@@ -1,97 +1,110 @@
// SPDX-License-Identifier: GPL-2.0
-use std::collections::HashSet;
-use std::fmt::Write;
+use std::{
+ collections::HashSet,
+ iter::Extend, //
+};
-use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
+use proc_macro2::{
+ Ident,
+ TokenStream, //
+};
+use quote::ToTokens;
+use syn::{
+ parse_quote,
+ Error,
+ ImplItem,
+ Item,
+ ItemImpl,
+ ItemTrait,
+ Result,
+ TraitItem, //
+};
-pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream {
- let mut tokens: Vec<_> = ts.into_iter().collect();
+fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
+ let mut gen_items = Vec::new();
+ let mut gen_consts = HashSet::new();
- // Scan for the `trait` or `impl` keyword.
- let is_trait = tokens
- .iter()
- .find_map(|token| match token {
- TokenTree::Ident(ident) => match ident.to_string().as_str() {
- "trait" => Some(true),
- "impl" => Some(false),
- _ => None,
- },
- _ => None,
- })
- .expect("#[vtable] attribute should only be applied to trait or impl block");
+ gen_items.push(parse_quote! {
+ /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
+ /// attribute when implementing this trait.
+ const USE_VTABLE_ATTR: ();
+ });
- // Retrieve the main body. The main body should be the last token tree.
- let body = match tokens.pop() {
- Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group,
- _ => panic!("cannot locate main body of trait or impl block"),
- };
-
- let mut body_it = body.stream().into_iter();
- let mut functions = Vec::new();
- let mut consts = HashSet::new();
- while let Some(token) = body_it.next() {
- match token {
- TokenTree::Ident(ident) if ident == "fn" => {
- let fn_name = match body_it.next() {
- Some(TokenTree::Ident(ident)) => ident.to_string(),
- // Possibly we've encountered a fn pointer type instead.
- _ => continue,
- };
- functions.push(fn_name);
- }
- TokenTree::Ident(ident) if ident == "const" => {
- let const_name = match body_it.next() {
- Some(TokenTree::Ident(ident)) => ident.to_string(),
- // Possibly we've encountered an inline const block instead.
- _ => continue,
- };
- consts.insert(const_name);
+ for item in &item.items {
+ if let TraitItem::Fn(fn_item) = item {
+ let name = &fn_item.sig.ident;
+ let gen_const_name = Ident::new(
+ &format!("HAS_{}", name.to_string().to_uppercase()),
+ name.span(),
+ );
+ // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
+ // define functions.
+ // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
+ if gen_consts.contains(&gen_const_name) {
+ continue;
}
- _ => (),
+
+ // We don't know on the implementation-site whether a method is required or provided
+ // so we have to generate a const for all methods.
+ let comment =
+ format!("Indicates if the `{name}` method is overridden by the implementor.");
+ gen_items.push(parse_quote! {
+ #[doc = #comment]
+ const #gen_const_name: bool = false;
+ });
+ gen_consts.insert(gen_const_name);
}
}
- let mut const_items;
- if is_trait {
- const_items = "
- /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
- /// attribute when implementing this trait.
- const USE_VTABLE_ATTR: ();
- "
- .to_owned();
+ item.items.extend(gen_items);
+ Ok(item)
+}
- for f in functions {
- let gen_const_name = format!("HAS_{}", f.to_uppercase());
- // Skip if it's declared already -- this allows user override.
- if consts.contains(&gen_const_name) {
- continue;
- }
- // We don't know on the implementation-site whether a method is required or provided
- // so we have to generate a const for all methods.
- write!(
- const_items,
- "/// Indicates if the `{f}` method is overridden by the implementor.
- const {gen_const_name}: bool = false;",
- )
- .unwrap();
- consts.insert(gen_const_name);
+fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
+ let mut gen_items = Vec::new();
+ let mut defined_consts = HashSet::new();
+
+ // Iterate over all user-defined constants to gather any possible explicit overrides.
+ for item in &item.items {
+ if let ImplItem::Const(const_item) = item {
+ defined_consts.insert(const_item.ident.clone());
}
- } else {
- const_items = "const USE_VTABLE_ATTR: () = ();".to_owned();
+ }
+
+ gen_items.push(parse_quote! {
+ const USE_VTABLE_ATTR: () = ();
+ });
- for f in functions {
- let gen_const_name = format!("HAS_{}", f.to_uppercase());
- if consts.contains(&gen_const_name) {
+ for item in &item.items {
+ if let ImplItem::Fn(fn_item) = item {
+ let name = &fn_item.sig.ident;
+ let gen_const_name = Ident::new(
+ &format!("HAS_{}", name.to_string().to_uppercase()),
+ name.span(),
+ );
+ // Skip if it's declared already -- this allows user override.
+ if defined_consts.contains(&gen_const_name) {
continue;
}
- write!(const_items, "const {gen_const_name}: bool = true;").unwrap();
+ gen_items.push(parse_quote! {
+ const #gen_const_name: bool = true;
+ });
+ defined_consts.insert(gen_const_name);
}
}
- let new_body = vec![const_items.parse().unwrap(), body.stream()]
- .into_iter()
- .collect();
- tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, new_body)));
- tokens.into_iter().collect()
+ item.items.extend(gen_items);
+ Ok(item)
+}
+
+pub(crate) fn vtable(input: Item) -> Result<TokenStream> {
+ match input {
+ Item::Trait(item) => Ok(handle_trait(item)?.into_token_stream()),
+ Item::Impl(item) => Ok(handle_impl(item)?.into_token_stream()),
+ _ => Err(Error::new_spanned(
+ input,
+ "`#[vtable]` attribute should only be applied to trait or impl block",
+ ))?,
+ }
}
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v3 03/12] rust: macros: convert `#[vtable]` macro to use `syn`
2026-01-12 17:07 ` [PATCH v3 03/12] rust: macros: convert `#[vtable]` macro to use `syn` Gary Guo
@ 2026-01-17 19:25 ` Benno Lossin
0 siblings, 0 replies; 25+ messages in thread
From: Benno Lossin @ 2026-01-17 19:25 UTC (permalink / raw)
To: Gary Guo, Miguel Ojeda, Boqun Feng, Björn Roy Baron,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Tamir Duberstein, José Expósito
Cc: rust-for-linux, Guilherme Giacomo Simoes, linux-kernel
On Mon Jan 12, 2026 at 6:07 PM CET, Gary Guo wrote:
> From: Gary Guo <gary@garyguo.net>
>
> `#[vtable]` is converted to use syn. This is more robust than the
> previous heuristic-based searching of defined methods and functions.
>
> When doing so, the trait and impl are split into two code paths as the
> types are distinct when parsed by `syn`.
>
> Reviewed-by: Tamir Duberstein <tamird@gmail.com>
> Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Cheers,
Benno
> ---
> rust/macros/lib.rs | 9 ++-
> rust/macros/vtable.rs | 169 +++++++++++++++++++++++-------------------
> 2 files changed, 98 insertions(+), 80 deletions(-)
^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v3 04/12] rust: macros: use `syn` to parse `module!` macro
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (2 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 03/12] rust: macros: convert `#[vtable]` macro to use `syn` Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-17 20:12 ` Benno Lossin
2026-01-12 17:07 ` [PATCH v3 05/12] rust: macros: use `quote!` for " Gary Guo
` (7 subsequent siblings)
11 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin, Tamir Duberstein, Igor Korotin,
José Expósito
Cc: rust-for-linux, linux-kernel, linux-modules
From: Gary Guo <gary@garyguo.net>
With `syn` being available in the kernel, use it to parse the complex
custom `module!` macro to replace existing helpers. Only parsing is
changed in this commit, the code generation is untouched.
This has the benefit of better error message when the macro is used
incorrectly, as it can point to a concrete span on what's going wrong.
For example, if a field is specified twice, previously it reads:
error: proc macro panicked
--> samples/rust/rust_minimal.rs:7:1
|
7 | / module! {
8 | | type: RustMinimal,
9 | | name: "rust_minimal",
10 | | author: "Rust for Linux Contributors",
11 | | description: "Rust minimal sample",
12 | | license: "GPL",
13 | | license: "GPL",
14 | | }
| |_^
|
= help: message: Duplicated key "license". Keys can only be specified once.
now it reads:
error: duplicated key "license". Keys can only be specified once.
--> samples/rust/rust_minimal.rs:13:5
|
13 | license: "GPL",
| ^^^^^^^
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/helpers.rs | 109 ++++-------
rust/macros/lib.rs | 6 +-
rust/macros/module.rs | 399 +++++++++++++++++++++++++----------------
3 files changed, 280 insertions(+), 234 deletions(-)
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index 13fafaba12261..fa66ef6eb0f3d 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -1,53 +1,21 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro2::{token_stream, Group, Ident, TokenStream, TokenTree};
-
-pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
- if let Some(TokenTree::Ident(ident)) = it.next() {
- Some(ident.to_string())
- } else {
- None
- }
-}
-
-pub(crate) fn try_sign(it: &mut token_stream::IntoIter) -> Option<char> {
- let peek = it.clone().next();
- match peek {
- Some(TokenTree::Punct(punct)) if punct.as_char() == '-' => {
- let _ = it.next();
- Some(punct.as_char())
- }
- _ => None,
- }
-}
-
-pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
- if let Some(TokenTree::Literal(literal)) = it.next() {
- Some(literal.to_string())
- } else {
- None
- }
-}
-
-pub(crate) fn try_string(it: &mut token_stream::IntoIter) -> Option<String> {
- try_literal(it).and_then(|string| {
- if string.starts_with('\"') && string.ends_with('\"') {
- let content = &string[1..string.len() - 1];
- if content.contains('\\') {
- panic!("Escape sequences in string literals not yet handled");
- }
- Some(content.to_string())
- } else if string.starts_with("r\"") {
- panic!("Raw string literals are not yet handled");
- } else {
- None
- }
- })
-}
-
-pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String {
- try_ident(it).expect("Expected Ident")
-}
+use proc_macro2::{
+ token_stream,
+ Ident,
+ TokenStream,
+ TokenTree, //
+};
+use quote::ToTokens;
+use syn::{
+ parse::{
+ Parse,
+ ParseStream, //
+ },
+ Error,
+ LitStr,
+ Result, //
+};
pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
@@ -57,27 +25,28 @@ pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
}
}
-pub(crate) fn expect_string(it: &mut token_stream::IntoIter) -> String {
- try_string(it).expect("Expected string")
-}
+/// A string literal that is required to have ASCII value only.
+pub(crate) struct AsciiLitStr(LitStr);
-pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String {
- let string = try_string(it).expect("Expected string");
- assert!(string.is_ascii(), "Expected ASCII string");
- string
+impl Parse for AsciiLitStr {
+ fn parse(input: ParseStream<'_>) -> Result<Self> {
+ let s: LitStr = input.parse()?;
+ if !s.value().is_ascii() {
+ return Err(Error::new_spanned(s, "expected ASCII-only string literal"));
+ }
+ Ok(Self(s))
+ }
}
-pub(crate) fn expect_group(it: &mut token_stream::IntoIter) -> Group {
- if let TokenTree::Group(group) = it.next().expect("Reached end of token stream for Group") {
- group
- } else {
- panic!("Expected Group");
+impl ToTokens for AsciiLitStr {
+ fn to_tokens(&self, ts: &mut TokenStream) {
+ self.0.to_tokens(ts);
}
}
-pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
- if it.next().is_some() {
- panic!("Expected end");
+impl AsciiLitStr {
+ pub(crate) fn value(&self) -> String {
+ self.0.value()
}
}
@@ -114,17 +83,3 @@ pub(crate) fn file() -> String {
proc_macro::Span::call_site().file()
}
}
-
-/// Parse a token stream of the form `expected_name: "value",` and return the
-/// string in the position of "value".
-///
-/// # Panics
-///
-/// - On parse error.
-pub(crate) fn expect_string_field(it: &mut token_stream::IntoIter, expected_name: &str) -> String {
- assert_eq!(expect_ident(it), expected_name);
- assert_eq!(expect_punct(it), ':');
- let string = expect_string(it);
- assert_eq!(expect_punct(it), ',');
- string
-}
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 9955c04dbaae3..c5347127a3a51 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -131,8 +131,10 @@
/// - `firmware`: array of ASCII string literals of the firmware files of
/// the kernel module.
#[proc_macro]
-pub fn module(ts: TokenStream) -> TokenStream {
- module::module(ts.into()).into()
+pub fn module(input: TokenStream) -> TokenStream {
+ module::module(parse_macro_input!(input))
+ .unwrap_or_else(|e| e.into_compile_error())
+ .into()
}
/// Declares or implements a vtable trait.
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index b855a2b586e18..9fdc9ed1faaf3 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -2,28 +2,30 @@
use std::fmt::Write;
-use proc_macro2::{token_stream, Delimiter, Literal, TokenStream, TokenTree};
+use proc_macro2::{
+ Literal,
+ TokenStream, //
+};
+use quote::ToTokens;
+use syn::{
+ braced,
+ bracketed,
+ ext::IdentExt,
+ parse::{
+ Parse,
+ ParseStream, //
+ },
+ punctuated::Punctuated,
+ Error,
+ Expr,
+ Ident,
+ LitStr,
+ Result,
+ Token, //
+};
use crate::helpers::*;
-fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> {
- let group = expect_group(it);
- assert_eq!(group.delimiter(), Delimiter::Bracket);
- let mut values = Vec::new();
- let mut it = group.stream().into_iter();
-
- while let Some(val) = try_string(&mut it) {
- assert!(val.is_ascii(), "Expected ASCII string");
- values.push(val);
- match it.next() {
- Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','),
- None => break,
- _ => panic!("Expected ',' or end of array"),
- }
- }
- values
-}
-
struct ModInfoBuilder<'a> {
module: &'a str,
counter: usize,
@@ -113,31 +115,35 @@ fn emit_params(&mut self, info: &ModuleInfo) {
};
for param in params {
- let ops = param_ops_path(¶m.ptype);
+ let param_name_str = param.name.to_string();
+ let param_type_str = param.ptype.to_string();
+ let param_default = param.default.to_token_stream().to_string();
+
+ let ops = param_ops_path(¶m_type_str);
// Note: The spelling of these fields is dictated by the user space
// tool `modinfo`.
- self.emit_param("parmtype", ¶m.name, ¶m.ptype);
- self.emit_param("parm", ¶m.name, ¶m.description);
+ self.emit_param("parmtype", ¶m_name_str, ¶m_type_str);
+ self.emit_param("parm", ¶m_name_str, ¶m.description.value());
write!(
self.param_buffer,
"
- pub(crate) static {param_name}:
- ::kernel::module_param::ModuleParamAccess<{param_type}> =
+ pub(crate) static {param_name_str}:
+ ::kernel::module_param::ModuleParamAccess<{param_type_str}> =
::kernel::module_param::ModuleParamAccess::new({param_default});
const _: () = {{
#[link_section = \"__param\"]
#[used]
- static __{module_name}_{param_name}_struct:
+ static __{module_name}_{param_name_str}_struct:
::kernel::module_param::KernelParam =
::kernel::module_param::KernelParam::new(
::kernel::bindings::kernel_param {{
name: if ::core::cfg!(MODULE) {{
- ::kernel::c_str!(\"{param_name}\").to_bytes_with_nul()
+ ::kernel::c_str!(\"{param_name_str}\").to_bytes_with_nul()
}} else {{
- ::kernel::c_str!(\"{module_name}.{param_name}\")
+ ::kernel::c_str!(\"{module_name}.{param_name_str}\")
.to_bytes_with_nul()
}}.as_ptr(),
// SAFETY: `__this_module` is constructed by the kernel at load
@@ -154,16 +160,13 @@ fn emit_params(&mut self, info: &ModuleInfo) {
level: -1,
flags: 0,
__bindgen_anon_1: ::kernel::bindings::kernel_param__bindgen_ty_1 {{
- arg: {param_name}.as_void_ptr()
+ arg: {param_name_str}.as_void_ptr()
}},
}}
);
}};
",
- module_name = info.name,
- param_type = param.ptype,
- param_default = param.default,
- param_name = param.name,
+ module_name = info.name.value(),
ops = ops,
)
.unwrap();
@@ -187,127 +190,78 @@ fn param_ops_path(param_type: &str) -> &'static str {
}
}
-fn expect_param_default(param_it: &mut token_stream::IntoIter) -> String {
- assert_eq!(expect_ident(param_it), "default");
- assert_eq!(expect_punct(param_it), ':');
- let sign = try_sign(param_it);
- let default = try_literal(param_it).expect("Expected default param value");
- assert_eq!(expect_punct(param_it), ',');
- let mut value = sign.map(String::from).unwrap_or_default();
- value.push_str(&default);
- value
-}
-
-#[derive(Debug, Default)]
-struct ModuleInfo {
- type_: String,
- license: String,
- name: String,
- authors: Option<Vec<String>>,
- description: Option<String>,
- alias: Option<Vec<String>>,
- firmware: Option<Vec<String>>,
- imports_ns: Option<Vec<String>>,
- params: Option<Vec<Parameter>>,
-}
-
-#[derive(Debug)]
-struct Parameter {
- name: String,
- ptype: String,
- default: String,
- description: String,
-}
-
-fn expect_params(it: &mut token_stream::IntoIter) -> Vec<Parameter> {
- let params = expect_group(it);
- assert_eq!(params.delimiter(), Delimiter::Brace);
- let mut it = params.stream().into_iter();
- let mut parsed = Vec::new();
-
- loop {
- let param_name = match it.next() {
- Some(TokenTree::Ident(ident)) => ident.to_string(),
- Some(_) => panic!("Expected Ident or end"),
- None => break,
- };
-
- assert_eq!(expect_punct(&mut it), ':');
- let param_type = expect_ident(&mut it);
- let group = expect_group(&mut it);
- assert_eq!(group.delimiter(), Delimiter::Brace);
- assert_eq!(expect_punct(&mut it), ',');
-
- let mut param_it = group.stream().into_iter();
- let param_default = expect_param_default(&mut param_it);
- let param_description = expect_string_field(&mut param_it, "description");
- expect_end(&mut param_it);
-
- parsed.push(Parameter {
- name: param_name,
- ptype: param_type,
- default: param_default,
- description: param_description,
- })
- }
-
- parsed
-}
-
-impl ModuleInfo {
- fn parse(it: &mut token_stream::IntoIter) -> Self {
- let mut info = ModuleInfo::default();
-
- const EXPECTED_KEYS: &[&str] = &[
- "type",
- "name",
- "authors",
- "description",
- "license",
- "alias",
- "firmware",
- "imports_ns",
- "params",
- ];
- const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
+/// Parse fields that are required to use a specific order.
+///
+/// As fields must follow a specific order, we *could* just parse fields one by one by peeking.
+/// However the error message generated when implementing that way is not very friendly.
+///
+/// So instead we parse fields in an arbitrary order, but only enforce the ordering after parsing,
+/// and if the wrong order is used, the proper order is communicated to the user with error message.
+///
+/// Usage looks like this:
+/// ```ignore
+/// parse_ordered_fields! {
+/// from input;
+///
+/// // This will extract "foo: <field>" into a variable named "foo".
+/// // The variable will have type `Option<_>`.
+/// foo => <expression that parses the field>,
+///
+/// // If you need the variable name to be different than the key name.
+/// // This extracts "baz: <field>" into a variable named "bar".
+/// // You might want this if "baz" is a keyword.
+/// baz as bar => <expression that parse the field>,
+///
+/// // You can mark a key as required, and the variable will no longer be `Option`.
+/// // foobar will be of type `Expr` instead of `Option<Expr>`.
+/// foobar [required] => input.parse::<Expr>()?,
+/// }
+/// ```
+macro_rules! parse_ordered_fields {
+ (@gen
+ [$input:expr]
+ [$([$name:ident; $key:ident; $parser:expr])*]
+ [$([$req_name:ident; $req_key:ident])*]
+ ) => {
+ $(let mut $name = None;)*
+
+ const EXPECTED_KEYS: &[&str] = &[$(stringify!($key),)*];
+ const REQUIRED_KEYS: &[&str] = &[$(stringify!($req_key),)*];
+
+ let span = $input.span();
let mut seen_keys = Vec::new();
- loop {
- let key = match it.next() {
- Some(TokenTree::Ident(ident)) => ident.to_string(),
- Some(_) => panic!("Expected Ident or end"),
- None => break,
- };
+ while !$input.is_empty() {
+ let key = $input.call(Ident::parse_any)?;
if seen_keys.contains(&key) {
- panic!("Duplicated key \"{key}\". Keys can only be specified once.");
+ Err(Error::new_spanned(
+ &key,
+ format!(r#"duplicated key "{key}". Keys can only be specified once."#),
+ ))?
}
- assert_eq!(expect_punct(it), ':');
-
- match key.as_str() {
- "type" => info.type_ = expect_ident(it),
- "name" => info.name = expect_string_ascii(it),
- "authors" => info.authors = Some(expect_string_array(it)),
- "description" => info.description = Some(expect_string(it)),
- "license" => info.license = expect_string_ascii(it),
- "alias" => info.alias = Some(expect_string_array(it)),
- "firmware" => info.firmware = Some(expect_string_array(it)),
- "imports_ns" => info.imports_ns = Some(expect_string_array(it)),
- "params" => info.params = Some(expect_params(it)),
- _ => panic!("Unknown key \"{key}\". Valid keys are: {EXPECTED_KEYS:?}."),
+ $input.parse::<Token![:]>()?;
+
+ match &*key.to_string() {
+ $(
+ stringify!($key) => $name = Some($parser),
+ )*
+ _ => {
+ Err(Error::new_spanned(
+ &key,
+ format!(r#"unknown key "{key}". Valid keys are: {EXPECTED_KEYS:?}."#),
+ ))?
+ }
}
- assert_eq!(expect_punct(it), ',');
-
+ $input.parse::<Token![,]>()?;
seen_keys.push(key);
}
- expect_end(it);
-
for key in REQUIRED_KEYS {
if !seen_keys.iter().any(|e| e == key) {
- panic!("Missing required key \"{key}\".");
+ Err(Error::new(span, format!(r#"missing required key "{key}""#)))?
}
}
@@ -319,43 +273,178 @@ fn parse(it: &mut token_stream::IntoIter) -> Self {
}
if seen_keys != ordered_keys {
- panic!("Keys are not ordered as expected. Order them like: {ordered_keys:?}.");
+ Err(Error::new(
+ span,
+ format!(r#"keys are not ordered as expected. Order them like: {ordered_keys:?}."#),
+ ))?
+ }
+
+ $(let $req_name = $req_name.expect("required field");)*
+ };
+
+ // Handle required fields.
+ (@gen
+ [$input:expr] [$($tok:tt)*] [$($req:tt)*]
+ $key:ident as $name:ident [required] => $parser:expr,
+ $($rest:tt)*
+ ) => {
+ parse_ordered_fields!(
+ @gen [$input] [$($tok)* [$name; $key; $parser]] [$($req)* [$name; $key]] $($rest)*
+ )
+ };
+ (@gen
+ [$input:expr] [$($tok:tt)*] [$($req:tt)*]
+ $name:ident [required] => $parser:expr,
+ $($rest:tt)*
+ ) => {
+ parse_ordered_fields!(
+ @gen [$input] [$($tok)* [$name; $name; $parser]] [$($req)* [$name; $name]] $($rest)*
+ )
+ };
+
+ // Handle optional fields.
+ (@gen
+ [$input:expr] [$($tok:tt)*] [$($req:tt)*]
+ $key:ident as $name:ident => $parser:expr,
+ $($rest:tt)*
+ ) => {
+ parse_ordered_fields!(
+ @gen [$input] [$($tok)* [$name; $key; $parser]] [$($req)*] $($rest)*
+ )
+ };
+ (@gen
+ [$input:expr] [$($tok:tt)*] [$($req:tt)*]
+ $name:ident => $parser:expr,
+ $($rest:tt)*
+ ) => {
+ parse_ordered_fields!(
+ @gen [$input] [$($tok)* [$name; $name; $parser]] [$($req)*] $($rest)*
+ )
+ };
+
+ (from $input:expr; $($tok:tt)*) => {
+ parse_ordered_fields!(@gen [$input] [] [] $($tok)*)
+ }
+}
+
+struct Parameter {
+ name: Ident,
+ ptype: Ident,
+ default: Expr,
+ description: LitStr,
+}
+
+impl Parse for Parameter {
+ fn parse(input: ParseStream<'_>) -> Result<Self> {
+ let name = input.parse()?;
+ input.parse::<Token![:]>()?;
+ let ptype = input.parse()?;
+
+ let fields;
+ braced!(fields in input);
+
+ parse_ordered_fields! {
+ from fields;
+ default [required] => fields.parse()?,
+ description [required] => fields.parse()?,
}
- info
+ Ok(Self {
+ name,
+ ptype,
+ default,
+ description,
+ })
}
}
-pub(crate) fn module(ts: TokenStream) -> TokenStream {
- let mut it = ts.into_iter();
+pub(crate) struct ModuleInfo {
+ type_: Ident,
+ license: AsciiLitStr,
+ name: AsciiLitStr,
+ authors: Option<Punctuated<AsciiLitStr, Token![,]>>,
+ description: Option<LitStr>,
+ alias: Option<Punctuated<AsciiLitStr, Token![,]>>,
+ firmware: Option<Punctuated<AsciiLitStr, Token![,]>>,
+ imports_ns: Option<Punctuated<AsciiLitStr, Token![,]>>,
+ params: Option<Punctuated<Parameter, Token![,]>>,
+}
- let info = ModuleInfo::parse(&mut it);
+impl Parse for ModuleInfo {
+ fn parse(input: ParseStream<'_>) -> Result<Self> {
+ parse_ordered_fields!(
+ from input;
+ type as type_ [required] => input.parse()?,
+ name [required] => input.parse()?,
+ authors => {
+ let list;
+ bracketed!(list in input);
+ Punctuated::parse_terminated(&list)?
+ },
+ description => input.parse()?,
+ license [required] => input.parse()?,
+ alias => {
+ let list;
+ bracketed!(list in input);
+ Punctuated::parse_terminated(&list)?
+ },
+ firmware => {
+ let list;
+ bracketed!(list in input);
+ Punctuated::parse_terminated(&list)?
+ },
+ imports_ns => {
+ let list;
+ bracketed!(list in input);
+ Punctuated::parse_terminated(&list)?
+ },
+ params => {
+ let list;
+ braced!(list in input);
+ Punctuated::parse_terminated(&list)?
+ },
+ );
+
+ Ok(ModuleInfo {
+ type_,
+ license,
+ name,
+ authors,
+ description,
+ alias,
+ firmware,
+ imports_ns,
+ params,
+ })
+ }
+}
+pub(crate) fn module(info: ModuleInfo) -> Result<TokenStream> {
// Rust does not allow hyphens in identifiers, use underscore instead.
- let ident = info.name.replace('-', "_");
+ let ident = info.name.value().replace('-', "_");
let mut modinfo = ModInfoBuilder::new(ident.as_ref());
if let Some(authors) = &info.authors {
for author in authors {
- modinfo.emit("author", author);
+ modinfo.emit("author", &author.value());
}
}
if let Some(description) = &info.description {
- modinfo.emit("description", description);
+ modinfo.emit("description", &description.value());
}
- modinfo.emit("license", &info.license);
+ modinfo.emit("license", &info.license.value());
if let Some(aliases) = &info.alias {
for alias in aliases {
- modinfo.emit("alias", alias);
+ modinfo.emit("alias", &alias.value());
}
}
if let Some(firmware) = &info.firmware {
for fw in firmware {
- modinfo.emit("firmware", fw);
+ modinfo.emit("firmware", &fw.value());
}
}
if let Some(imports) = &info.imports_ns {
for ns in imports {
- modinfo.emit("import_ns", ns);
+ modinfo.emit("import_ns", &ns.value());
}
}
@@ -366,7 +455,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream {
modinfo.emit_params(&info);
- format!(
+ Ok(format!(
"
/// The module name.
///
@@ -536,12 +625,12 @@ mod module_parameters {{
}}
",
type_ = info.type_,
- name = info.name,
+ name = info.name.value(),
ident = ident,
modinfo = modinfo.buffer,
params = modinfo.param_buffer,
initcall_section = ".initcall6.init"
)
.parse()
- .expect("Error parsing formatted string into token stream.")
+ .expect("Error parsing formatted string into token stream."))
}
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v3 04/12] rust: macros: use `syn` to parse `module!` macro
2026-01-12 17:07 ` [PATCH v3 04/12] rust: macros: use `syn` to parse `module!` macro Gary Guo
@ 2026-01-17 20:12 ` Benno Lossin
0 siblings, 0 replies; 25+ messages in thread
From: Benno Lossin @ 2026-01-17 20:12 UTC (permalink / raw)
To: Gary Guo, Miguel Ojeda, Boqun Feng, Björn Roy Baron,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen,
Aaron Tomlin, Tamir Duberstein, Igor Korotin,
José Expósito
Cc: rust-for-linux, linux-kernel, linux-modules
On Mon Jan 12, 2026 at 6:07 PM CET, Gary Guo wrote:
> From: Gary Guo <gary@garyguo.net>
>
> With `syn` being available in the kernel, use it to parse the complex
> custom `module!` macro to replace existing helpers. Only parsing is
> changed in this commit, the code generation is untouched.
>
> This has the benefit of better error message when the macro is used
> incorrectly, as it can point to a concrete span on what's going wrong.
>
> For example, if a field is specified twice, previously it reads:
>
> error: proc macro panicked
> --> samples/rust/rust_minimal.rs:7:1
> |
> 7 | / module! {
> 8 | | type: RustMinimal,
> 9 | | name: "rust_minimal",
> 10 | | author: "Rust for Linux Contributors",
> 11 | | description: "Rust minimal sample",
> 12 | | license: "GPL",
> 13 | | license: "GPL",
> 14 | | }
> | |_^
> |
> = help: message: Duplicated key "license". Keys can only be specified once.
>
> now it reads:
>
> error: duplicated key "license". Keys can only be specified once.
> --> samples/rust/rust_minimal.rs:13:5
> |
> 13 | license: "GPL",
> | ^^^^^^^
>
> Reviewed-by: Tamir Duberstein <tamird@gmail.com>
> Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Cheers,
Benno
> ---
> rust/macros/helpers.rs | 109 ++++-------
> rust/macros/lib.rs | 6 +-
> rust/macros/module.rs | 399 +++++++++++++++++++++++++----------------
> 3 files changed, 280 insertions(+), 234 deletions(-)
^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v3 05/12] rust: macros: use `quote!` for `module!` macro
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (3 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 04/12] rust: macros: use `syn` to parse `module!` macro Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:07 ` [PATCH v3 06/12] rust: macros: convert `#[export]` to use `syn` Gary Guo
` (6 subsequent siblings)
11 siblings, 0 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin
Cc: rust-for-linux, linux-modules, linux-kernel
From: Gary Guo <gary@garyguo.net>
This has no behavioural change, but is good for maintainability. With
`quote!`, we're no longer using string templates, so we don't need to
quote " and {} inside the template anymore. Further more, editors can
now highlight the code template.
This also improves the robustness as it eliminates the need for string
quoting and escaping.
Co-developed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/module.rs | 543 ++++++++++++++++++++++--------------------
1 file changed, 286 insertions(+), 257 deletions(-)
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 9fdc9ed1faaf3..43ada49525c9d 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -1,12 +1,15 @@
// SPDX-License-Identifier: GPL-2.0
-use std::fmt::Write;
+use std::ffi::CString;
use proc_macro2::{
Literal,
TokenStream, //
};
-use quote::ToTokens;
+use quote::{
+ format_ident,
+ quote, //
+};
use syn::{
braced,
bracketed,
@@ -15,11 +18,13 @@
Parse,
ParseStream, //
},
+ parse_quote,
punctuated::Punctuated,
Error,
Expr,
Ident,
LitStr,
+ Path,
Result,
Token, //
};
@@ -29,8 +34,8 @@
struct ModInfoBuilder<'a> {
module: &'a str,
counter: usize,
- buffer: String,
- param_buffer: String,
+ ts: TokenStream,
+ param_ts: TokenStream,
}
impl<'a> ModInfoBuilder<'a> {
@@ -38,8 +43,8 @@ fn new(module: &'a str) -> Self {
ModInfoBuilder {
module,
counter: 0,
- buffer: String::new(),
- param_buffer: String::new(),
+ ts: TokenStream::new(),
+ param_ts: TokenStream::new(),
}
}
@@ -56,33 +61,32 @@ fn emit_base(&mut self, field: &str, content: &str, builtin: bool, param: bool)
// Loadable modules' modinfo strings go as-is.
format!("{field}={content}\0")
};
-
- let buffer = if param {
- &mut self.param_buffer
+ let length = string.len();
+ let string = Literal::byte_string(string.as_bytes());
+ let cfg = if builtin {
+ quote!(#[cfg(not(MODULE))])
} else {
- &mut self.buffer
+ quote!(#[cfg(MODULE)])
};
- write!(
- buffer,
- "
- {cfg}
- #[doc(hidden)]
- #[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")]
- #[used(compiler)]
- pub static __{module}_{counter}: [u8; {length}] = *{string};
- ",
- cfg = if builtin {
- "#[cfg(not(MODULE))]"
- } else {
- "#[cfg(MODULE)]"
- },
+ let counter = format_ident!(
+ "__{module}_{counter}",
module = self.module.to_uppercase(),
- counter = self.counter,
- length = string.len(),
- string = Literal::byte_string(string.as_bytes()),
- )
- .unwrap();
+ counter = self.counter
+ );
+ let item = quote! {
+ #cfg
+ #[doc(hidden)]
+ #[cfg_attr(not(target_os = "macos"), link_section = ".modinfo")]
+ #[used(compiler)]
+ pub static #counter: [u8; #length] = *#string;
+ };
+
+ if param {
+ self.param_ts.extend(item);
+ } else {
+ self.ts.extend(item);
+ }
self.counter += 1;
}
@@ -117,7 +121,6 @@ fn emit_params(&mut self, info: &ModuleInfo) {
for param in params {
let param_name_str = param.name.to_string();
let param_type_str = param.ptype.to_string();
- let param_default = param.default.to_token_stream().to_string();
let ops = param_ops_path(¶m_type_str);
@@ -126,66 +129,74 @@ fn emit_params(&mut self, info: &ModuleInfo) {
self.emit_param("parmtype", ¶m_name_str, ¶m_type_str);
self.emit_param("parm", ¶m_name_str, ¶m.description.value());
- write!(
- self.param_buffer,
- "
- pub(crate) static {param_name_str}:
- ::kernel::module_param::ModuleParamAccess<{param_type_str}> =
- ::kernel::module_param::ModuleParamAccess::new({param_default});
-
- const _: () = {{
- #[link_section = \"__param\"]
- #[used]
- static __{module_name}_{param_name_str}_struct:
+ let static_name = format_ident!("__{}_{}_struct", self.module, param.name);
+ let param_name_cstr =
+ CString::new(param_name_str).expect("name contains NUL-terminator");
+ let param_name_cstr_with_module =
+ CString::new(format!("{}.{}", self.module, param.name))
+ .expect("name contains NUL-terminator");
+
+ let param_name = ¶m.name;
+ let param_type = ¶m.ptype;
+ let param_default = ¶m.default;
+
+ self.param_ts.extend(quote! {
+ #[allow(non_upper_case_globals)]
+ pub(crate) static #param_name:
+ ::kernel::module_param::ModuleParamAccess<#param_type> =
+ ::kernel::module_param::ModuleParamAccess::new(#param_default);
+
+ const _: () = {
+ #[allow(non_upper_case_globals)]
+ #[link_section = "__param"]
+ #[used(compiler)]
+ static #static_name:
::kernel::module_param::KernelParam =
::kernel::module_param::KernelParam::new(
- ::kernel::bindings::kernel_param {{
- name: if ::core::cfg!(MODULE) {{
- ::kernel::c_str!(\"{param_name_str}\").to_bytes_with_nul()
- }} else {{
- ::kernel::c_str!(\"{module_name}.{param_name_str}\")
- .to_bytes_with_nul()
- }}.as_ptr(),
+ ::kernel::bindings::kernel_param {
+ name: kernel::str::as_char_ptr_in_const_context(
+ if ::core::cfg!(MODULE) {
+ #param_name_cstr
+ } else {
+ #param_name_cstr_with_module
+ }
+ ),
// SAFETY: `__this_module` is constructed by the kernel at load
// time and will not be freed until the module is unloaded.
#[cfg(MODULE)]
- mod_: unsafe {{
+ mod_: unsafe {
core::ptr::from_ref(&::kernel::bindings::__this_module)
.cast_mut()
- }},
+ },
#[cfg(not(MODULE))]
mod_: ::core::ptr::null_mut(),
- ops: core::ptr::from_ref(&{ops}),
+ ops: core::ptr::from_ref(&#ops),
perm: 0, // Will not appear in sysfs
level: -1,
flags: 0,
- __bindgen_anon_1: ::kernel::bindings::kernel_param__bindgen_ty_1 {{
- arg: {param_name_str}.as_void_ptr()
- }},
- }}
+ __bindgen_anon_1: ::kernel::bindings::kernel_param__bindgen_ty_1 {
+ arg: #param_name.as_void_ptr()
+ },
+ }
);
- }};
- ",
- module_name = info.name.value(),
- ops = ops,
- )
- .unwrap();
+ };
+ });
}
}
}
-fn param_ops_path(param_type: &str) -> &'static str {
+fn param_ops_path(param_type: &str) -> Path {
match param_type {
- "i8" => "::kernel::module_param::PARAM_OPS_I8",
- "u8" => "::kernel::module_param::PARAM_OPS_U8",
- "i16" => "::kernel::module_param::PARAM_OPS_I16",
- "u16" => "::kernel::module_param::PARAM_OPS_U16",
- "i32" => "::kernel::module_param::PARAM_OPS_I32",
- "u32" => "::kernel::module_param::PARAM_OPS_U32",
- "i64" => "::kernel::module_param::PARAM_OPS_I64",
- "u64" => "::kernel::module_param::PARAM_OPS_U64",
- "isize" => "::kernel::module_param::PARAM_OPS_ISIZE",
- "usize" => "::kernel::module_param::PARAM_OPS_USIZE",
+ "i8" => parse_quote!(::kernel::module_param::PARAM_OPS_I8),
+ "u8" => parse_quote!(::kernel::module_param::PARAM_OPS_U8),
+ "i16" => parse_quote!(::kernel::module_param::PARAM_OPS_I16),
+ "u16" => parse_quote!(::kernel::module_param::PARAM_OPS_U16),
+ "i32" => parse_quote!(::kernel::module_param::PARAM_OPS_I32),
+ "u32" => parse_quote!(::kernel::module_param::PARAM_OPS_U32),
+ "i64" => parse_quote!(::kernel::module_param::PARAM_OPS_I64),
+ "u64" => parse_quote!(::kernel::module_param::PARAM_OPS_U64),
+ "isize" => parse_quote!(::kernel::module_param::PARAM_OPS_ISIZE),
+ "usize" => parse_quote!(::kernel::module_param::PARAM_OPS_USIZE),
t => panic!("Unsupported parameter type {}", t),
}
}
@@ -420,29 +431,41 @@ fn parse(input: ParseStream<'_>) -> Result<Self> {
}
pub(crate) fn module(info: ModuleInfo) -> Result<TokenStream> {
+ let ModuleInfo {
+ type_,
+ license,
+ name,
+ authors,
+ description,
+ alias,
+ firmware,
+ imports_ns,
+ params: _,
+ } = &info;
+
// Rust does not allow hyphens in identifiers, use underscore instead.
- let ident = info.name.value().replace('-', "_");
+ let ident = name.value().replace('-', "_");
let mut modinfo = ModInfoBuilder::new(ident.as_ref());
- if let Some(authors) = &info.authors {
+ if let Some(authors) = authors {
for author in authors {
modinfo.emit("author", &author.value());
}
}
- if let Some(description) = &info.description {
+ if let Some(description) = description {
modinfo.emit("description", &description.value());
}
- modinfo.emit("license", &info.license.value());
- if let Some(aliases) = &info.alias {
+ modinfo.emit("license", &license.value());
+ if let Some(aliases) = alias {
for alias in aliases {
modinfo.emit("alias", &alias.value());
}
}
- if let Some(firmware) = &info.firmware {
+ if let Some(firmware) = firmware {
for fw in firmware {
modinfo.emit("firmware", &fw.value());
}
}
- if let Some(imports) = &info.imports_ns {
+ if let Some(imports) = imports_ns {
for ns in imports {
modinfo.emit("import_ns", &ns.value());
}
@@ -455,182 +478,188 @@ pub(crate) fn module(info: ModuleInfo) -> Result<TokenStream> {
modinfo.emit_params(&info);
- Ok(format!(
- "
- /// The module name.
- ///
- /// Used by the printing macros, e.g. [`info!`].
- const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
-
- // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
- // freed until the module is unloaded.
- #[cfg(MODULE)]
- static THIS_MODULE: ::kernel::ThisModule = unsafe {{
- extern \"C\" {{
- static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
- }}
-
- ::kernel::ThisModule::from_ptr(__this_module.get())
- }};
- #[cfg(not(MODULE))]
- static THIS_MODULE: ::kernel::ThisModule = unsafe {{
- ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
- }};
-
- /// The `LocalModule` type is the type of the module created by `module!`,
- /// `module_pci_driver!`, `module_platform_driver!`, etc.
- type LocalModule = {type_};
-
- impl ::kernel::ModuleMetadata for {type_} {{
- const NAME: &'static ::kernel::str::CStr = c\"{name}\";
- }}
-
- // Double nested modules, since then nobody can access the public items inside.
- mod __module_init {{
- mod __module_init {{
- use super::super::{type_};
- use pin_init::PinInit;
-
- /// The \"Rust loadable module\" mark.
- //
- // This may be best done another way later on, e.g. as a new modinfo
- // key or a new section. For the moment, keep it simple.
- #[cfg(MODULE)]
- #[doc(hidden)]
- #[used(compiler)]
- static __IS_RUST_MODULE: () = ();
-
- static mut __MOD: ::core::mem::MaybeUninit<{type_}> =
- ::core::mem::MaybeUninit::uninit();
-
- // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
- /// # Safety
- ///
- /// This function must not be called after module initialization, because it may be
- /// freed after that completes.
- #[cfg(MODULE)]
- #[doc(hidden)]
- #[no_mangle]
- #[link_section = \".init.text\"]
- pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{
- // SAFETY: This function is inaccessible to the outside due to the double
- // module wrapping it. It is called exactly once by the C side via its
- // unique name.
- unsafe {{ __init() }}
- }}
-
- #[cfg(MODULE)]
- #[doc(hidden)]
- #[used(compiler)]
- #[link_section = \".init.data\"]
- static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module;
-
- #[cfg(MODULE)]
- #[doc(hidden)]
- #[no_mangle]
- #[link_section = \".exit.text\"]
- pub extern \"C\" fn cleanup_module() {{
- // SAFETY:
- // - This function is inaccessible to the outside due to the double
- // module wrapping it. It is called exactly once by the C side via its
- // unique name,
- // - furthermore it is only called after `init_module` has returned `0`
- // (which delegates to `__init`).
- unsafe {{ __exit() }}
- }}
-
- #[cfg(MODULE)]
- #[doc(hidden)]
- #[used(compiler)]
- #[link_section = \".exit.data\"]
- static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module;
-
- // Built-in modules are initialized through an initcall pointer
- // and the identifiers need to be unique.
- #[cfg(not(MODULE))]
- #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
- #[doc(hidden)]
- #[link_section = \"{initcall_section}\"]
- #[used(compiler)]
- pub static __{ident}_initcall: extern \"C\" fn() ->
- ::kernel::ffi::c_int = __{ident}_init;
-
- #[cfg(not(MODULE))]
- #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
- ::core::arch::global_asm!(
- r#\".section \"{initcall_section}\", \"a\"
- __{ident}_initcall:
- .long __{ident}_init - .
- .previous
- \"#
- );
-
- #[cfg(not(MODULE))]
- #[doc(hidden)]
- #[no_mangle]
- pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{
- // SAFETY: This function is inaccessible to the outside due to the double
- // module wrapping it. It is called exactly once by the C side via its
- // placement above in the initcall section.
- unsafe {{ __init() }}
- }}
-
- #[cfg(not(MODULE))]
- #[doc(hidden)]
- #[no_mangle]
- pub extern \"C\" fn __{ident}_exit() {{
- // SAFETY:
- // - This function is inaccessible to the outside due to the double
- // module wrapping it. It is called exactly once by the C side via its
- // unique name,
- // - furthermore it is only called after `__{ident}_init` has
- // returned `0` (which delegates to `__init`).
- unsafe {{ __exit() }}
- }}
-
- /// # Safety
- ///
- /// This function must only be called once.
- unsafe fn __init() -> ::kernel::ffi::c_int {{
- let initer =
- <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
- // SAFETY: No data race, since `__MOD` can only be accessed by this module
- // and there only `__init` and `__exit` access it. These functions are only
- // called once and `__exit` cannot be called before or during `__init`.
- match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{
- Ok(m) => 0,
- Err(e) => e.to_errno(),
- }}
- }}
-
- /// # Safety
- ///
- /// This function must
- /// - only be called once,
- /// - be called after `__init` has been called and returned `0`.
- unsafe fn __exit() {{
- // SAFETY: No data race, since `__MOD` can only be accessed by this module
- // and there only `__init` and `__exit` access it. These functions are only
- // called once and `__init` was already called.
- unsafe {{
- // Invokes `drop()` on `__MOD`, which should be used for cleanup.
- __MOD.assume_init_drop();
- }}
- }}
- {modinfo}
- }}
- }}
- mod module_parameters {{
- {params}
- }}
- ",
- type_ = info.type_,
- name = info.name.value(),
- ident = ident,
- modinfo = modinfo.buffer,
- params = modinfo.param_buffer,
- initcall_section = ".initcall6.init"
- )
- .parse()
- .expect("Error parsing formatted string into token stream."))
+ let modinfo_ts = modinfo.ts;
+ let params_ts = modinfo.param_ts;
+
+ let ident_init = format_ident!("__{ident}_init");
+ let ident_exit = format_ident!("__{ident}_exit");
+ let ident_initcall = format_ident!("__{ident}_initcall");
+ let initcall_section = ".initcall6.init";
+
+ let global_asm = format!(
+ r#".section "{initcall_section}", "a"
+ __{ident}_initcall:
+ .long __{ident}_init - .
+ .previous
+ "#
+ );
+
+ let name_cstr = CString::new(name.value()).expect("name contains NUL-terminator");
+
+ Ok(quote! {
+ /// The module name.
+ ///
+ /// Used by the printing macros, e.g. [`info!`].
+ const __LOG_PREFIX: &[u8] = #name_cstr.to_bytes_with_nul();
+
+ // SAFETY: `__this_module` is constructed by the kernel at load time and will not be
+ // freed until the module is unloaded.
+ #[cfg(MODULE)]
+ static THIS_MODULE: ::kernel::ThisModule = unsafe {
+ extern "C" {
+ static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>;
+ };
+
+ ::kernel::ThisModule::from_ptr(__this_module.get())
+ };
+
+ #[cfg(not(MODULE))]
+ static THIS_MODULE: ::kernel::ThisModule = unsafe {
+ ::kernel::ThisModule::from_ptr(::core::ptr::null_mut())
+ };
+
+ /// The `LocalModule` type is the type of the module created by `module!`,
+ /// `module_pci_driver!`, `module_platform_driver!`, etc.
+ type LocalModule = #type_;
+
+ impl ::kernel::ModuleMetadata for #type_ {
+ const NAME: &'static ::kernel::str::CStr = #name_cstr;
+ }
+
+ // Double nested modules, since then nobody can access the public items inside.
+ mod __module_init {
+ mod __module_init {
+ use super::super::#type_;
+ use pin_init::PinInit;
+
+ /// The "Rust loadable module" mark.
+ //
+ // This may be best done another way later on, e.g. as a new modinfo
+ // key or a new section. For the moment, keep it simple.
+ #[cfg(MODULE)]
+ #[doc(hidden)]
+ #[used(compiler)]
+ static __IS_RUST_MODULE: () = ();
+
+ static mut __MOD: ::core::mem::MaybeUninit<#type_> =
+ ::core::mem::MaybeUninit::uninit();
+
+ // Loadable modules need to export the `{init,cleanup}_module` identifiers.
+ /// # Safety
+ ///
+ /// This function must not be called after module initialization, because it may be
+ /// freed after that completes.
+ #[cfg(MODULE)]
+ #[doc(hidden)]
+ #[no_mangle]
+ #[link_section = ".init.text"]
+ pub unsafe extern "C" fn init_module() -> ::kernel::ffi::c_int {
+ // SAFETY: This function is inaccessible to the outside due to the double
+ // module wrapping it. It is called exactly once by the C side via its
+ // unique name.
+ unsafe { __init() }
+ }
+
+ #[cfg(MODULE)]
+ #[doc(hidden)]
+ #[used(compiler)]
+ #[link_section = ".init.data"]
+ static __UNIQUE_ID___addressable_init_module: unsafe extern "C" fn() -> i32 =
+ init_module;
+
+ #[cfg(MODULE)]
+ #[doc(hidden)]
+ #[no_mangle]
+ #[link_section = ".exit.text"]
+ pub extern "C" fn cleanup_module() {
+ // SAFETY:
+ // - This function is inaccessible to the outside due to the double
+ // module wrapping it. It is called exactly once by the C side via its
+ // unique name,
+ // - furthermore it is only called after `init_module` has returned `0`
+ // (which delegates to `__init`).
+ unsafe { __exit() }
+ }
+
+ #[cfg(MODULE)]
+ #[doc(hidden)]
+ #[used(compiler)]
+ #[link_section = ".exit.data"]
+ static __UNIQUE_ID___addressable_cleanup_module: extern "C" fn() = cleanup_module;
+
+ // Built-in modules are initialized through an initcall pointer
+ // and the identifiers need to be unique.
+ #[cfg(not(MODULE))]
+ #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
+ #[doc(hidden)]
+ #[link_section = #initcall_section]
+ #[used(compiler)]
+ pub static #ident_initcall: extern "C" fn() ->
+ ::kernel::ffi::c_int = #ident_init;
+
+ #[cfg(not(MODULE))]
+ #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
+ ::core::arch::global_asm!(#global_asm);
+
+ #[cfg(not(MODULE))]
+ #[doc(hidden)]
+ #[no_mangle]
+ pub extern "C" fn #ident_init() -> ::kernel::ffi::c_int {
+ // SAFETY: This function is inaccessible to the outside due to the double
+ // module wrapping it. It is called exactly once by the C side via its
+ // placement above in the initcall section.
+ unsafe { __init() }
+ }
+
+ #[cfg(not(MODULE))]
+ #[doc(hidden)]
+ #[no_mangle]
+ pub extern "C" fn #ident_exit() {
+ // SAFETY:
+ // - This function is inaccessible to the outside due to the double
+ // module wrapping it. It is called exactly once by the C side via its
+ // unique name,
+ // - furthermore it is only called after `#ident_init` has
+ // returned `0` (which delegates to `__init`).
+ unsafe { __exit() }
+ }
+
+ /// # Safety
+ ///
+ /// This function must only be called once.
+ unsafe fn __init() -> ::kernel::ffi::c_int {
+ let initer =
+ <#type_ as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
+ // SAFETY: No data race, since `__MOD` can only be accessed by this module
+ // and there only `__init` and `__exit` access it. These functions are only
+ // called once and `__exit` cannot be called before or during `__init`.
+ match unsafe { initer.__pinned_init(__MOD.as_mut_ptr()) } {
+ Ok(m) => 0,
+ Err(e) => e.to_errno(),
+ }
+ }
+
+ /// # Safety
+ ///
+ /// This function must
+ /// - only be called once,
+ /// - be called after `__init` has been called and returned `0`.
+ unsafe fn __exit() {
+ // SAFETY: No data race, since `__MOD` can only be accessed by this module
+ // and there only `__init` and `__exit` access it. These functions are only
+ // called once and `__init` was already called.
+ unsafe {
+ // Invokes `drop()` on `__MOD`, which should be used for cleanup.
+ __MOD.assume_init_drop();
+ }
+ }
+
+ #modinfo_ts
+ }
+ }
+
+ mod module_parameters {
+ #params_ts
+ }
+ })
}
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v3 06/12] rust: macros: convert `#[export]` to use `syn`
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (4 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 05/12] rust: macros: use `quote!` for " Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:07 ` [PATCH v3 07/12] rust: macros: convert `concat_idents!` " Gary Guo
` (5 subsequent siblings)
11 siblings, 0 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Tamir Duberstein, Greg Kroah-Hartman,
Guilherme Giacomo Simoes, José Expósito
Cc: rust-for-linux, linux-kernel
From: Gary Guo <gary@garyguo.net>
This eliminates the custom `function_name` helper.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/export.rs | 24 +++++++++---------------
rust/macros/helpers.rs | 18 ------------------
rust/macros/lib.rs | 5 +++--
3 files changed, 12 insertions(+), 35 deletions(-)
diff --git a/rust/macros/export.rs b/rust/macros/export.rs
index 92d9b30971929..6d53521f62fc7 100644
--- a/rust/macros/export.rs
+++ b/rust/macros/export.rs
@@ -3,19 +3,14 @@
use proc_macro2::TokenStream;
use quote::quote;
-use crate::helpers::function_name;
-
/// Please see [`crate::export`] for documentation.
-pub(crate) fn export(_attr: TokenStream, ts: TokenStream) -> TokenStream {
- let Some(name) = function_name(ts.clone()) else {
- return "::core::compile_error!(\"The #[export] attribute must be used on a function.\");"
- .parse::<TokenStream>()
- .unwrap();
- };
+pub(crate) fn export(f: syn::ItemFn) -> TokenStream {
+ let name = &f.sig.ident;
- // This verifies that the function has the same signature as the declaration generated by
- // bindgen. It makes use of the fact that all branches of an if/else must have the same type.
- let signature_check = quote!(
+ quote! {
+ // This verifies that the function has the same signature as the declaration generated by
+ // bindgen. It makes use of the fact that all branches of an if/else must have the same
+ // type.
const _: () = {
if true {
::kernel::bindings::#name
@@ -23,9 +18,8 @@ pub(crate) fn export(_attr: TokenStream, ts: TokenStream) -> TokenStream {
#name
};
};
- );
-
- let no_mangle = quote!(#[no_mangle]);
- TokenStream::from_iter([signature_check, no_mangle, ts])
+ #[no_mangle]
+ #f
+ }
}
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index fa66ef6eb0f3d..754c827cc21e1 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -2,7 +2,6 @@
use proc_macro2::{
token_stream,
- Ident,
TokenStream,
TokenTree, //
};
@@ -50,23 +49,6 @@ pub(crate) fn value(&self) -> String {
}
}
-/// Given a function declaration, finds the name of the function.
-pub(crate) fn function_name(input: TokenStream) -> Option<Ident> {
- let mut input = input.into_iter();
- while let Some(token) = input.next() {
- match token {
- TokenTree::Ident(i) if i == "fn" => {
- if let Some(TokenTree::Ident(i)) = input.next() {
- return Some(i);
- }
- return None;
- }
- _ => continue,
- }
- }
- None
-}
-
pub(crate) fn file() -> String {
#[cfg(not(CONFIG_RUSTC_HAS_SPAN_FILE))]
{
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index c5347127a3a51..da8239d2474b6 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -234,8 +234,9 @@ pub fn vtable(attr: TokenStream, input: TokenStream) -> TokenStream {
/// This macro is *not* the same as the C macros `EXPORT_SYMBOL_*`. All Rust symbols are currently
/// automatically exported with `EXPORT_SYMBOL_GPL`.
#[proc_macro_attribute]
-pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream {
- export::export(attr.into(), ts.into()).into()
+pub fn export(attr: TokenStream, input: TokenStream) -> TokenStream {
+ parse_macro_input!(attr as syn::parse::Nothing);
+ export::export(parse_macro_input!(input)).into()
}
/// Like [`core::format_args!`], but automatically wraps arguments in [`kernel::fmt::Adapter`].
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v3 07/12] rust: macros: convert `concat_idents!` to use `syn`
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (5 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 06/12] rust: macros: convert `#[export]` to use `syn` Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:07 ` [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro " Gary Guo
` (4 subsequent siblings)
11 siblings, 0 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Tamir Duberstein, Guilherme Giacomo Simoes,
Igor Korotin, José Expósito
Cc: rust-for-linux, linux-kernel
From: Gary Guo <gary@garyguo.net>
This eliminates the need for `expect_punct` helper.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/concat_idents.rs | 39 ++++++++++++++++++++++++------------
rust/macros/helpers.rs | 14 +------------
rust/macros/lib.rs | 4 ++--
3 files changed, 29 insertions(+), 28 deletions(-)
diff --git a/rust/macros/concat_idents.rs b/rust/macros/concat_idents.rs
index 12cb231c3d715..47b6add378d2c 100644
--- a/rust/macros/concat_idents.rs
+++ b/rust/macros/concat_idents.rs
@@ -1,23 +1,36 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro2::{token_stream, Ident, TokenStream, TokenTree};
+use proc_macro2::{
+ Ident,
+ TokenStream,
+ TokenTree, //
+};
+use syn::{
+ parse::{
+ Parse,
+ ParseStream, //
+ },
+ Result,
+ Token, //
+};
-use crate::helpers::expect_punct;
+pub(crate) struct Input {
+ a: Ident,
+ _comma: Token![,],
+ b: Ident,
+}
-fn expect_ident(it: &mut token_stream::IntoIter) -> Ident {
- if let Some(TokenTree::Ident(ident)) = it.next() {
- ident
- } else {
- panic!("Expected Ident")
+impl Parse for Input {
+ fn parse(input: ParseStream<'_>) -> Result<Self> {
+ Ok(Self {
+ a: input.parse()?,
+ _comma: input.parse()?,
+ b: input.parse()?,
+ })
}
}
-pub(crate) fn concat_idents(ts: TokenStream) -> TokenStream {
- let mut it = ts.into_iter();
- let a = expect_ident(&mut it);
- assert_eq!(expect_punct(&mut it), ',');
- let b = expect_ident(&mut it);
- assert!(it.next().is_none(), "only two idents can be concatenated");
+pub(crate) fn concat_idents(Input { a, b, .. }: Input) -> TokenStream {
let res = Ident::new(&format!("{a}{b}"), b.span());
TokenStream::from_iter([TokenTree::Ident(res)])
}
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index 754c827cc21e1..adfa60d8f42d8 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -1,10 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
-use proc_macro2::{
- token_stream,
- TokenStream,
- TokenTree, //
-};
+use proc_macro2::TokenStream;
use quote::ToTokens;
use syn::{
parse::{
@@ -16,14 +12,6 @@
Result, //
};
-pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
- if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
- punct.as_char()
- } else {
- panic!("Expected Punct");
- }
-}
-
/// A string literal that is required to have ASCII value only.
pub(crate) struct AsciiLitStr(LitStr);
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index da8239d2474b6..12467bfc703a8 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -311,8 +311,8 @@ pub fn fmt(input: TokenStream) -> TokenStream {
/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK);
/// ```
#[proc_macro]
-pub fn concat_idents(ts: TokenStream) -> TokenStream {
- concat_idents::concat_idents(ts.into()).into()
+pub fn concat_idents(input: TokenStream) -> TokenStream {
+ concat_idents::concat_idents(parse_macro_input!(input)).into()
}
/// Paste identifiers together.
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro to use `syn`
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (6 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 07/12] rust: macros: convert `concat_idents!` " Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-17 20:09 ` Benno Lossin
2026-01-19 7:10 ` David Gow
2026-01-12 17:07 ` [PATCH v3 09/12] rust: macros: allow arbitrary types to be used in `module!` macro Gary Guo
` (3 subsequent siblings)
11 siblings, 2 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Brendan Higgins, David Gow, Rae Moar,
Tamir Duberstein, Igor Korotin, José Expósito
Cc: rust-for-linux, Guilherme Giacomo Simoes, linux-kselftest,
kunit-dev, linux-kernel
From: Gary Guo <gary@garyguo.net>
Make use of `syn` to parse the module structurally and thus improve the
robustness of parsing.
String interpolation is avoided by generating tokens directly using
`quote!`.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/kunit.rs | 274 +++++++++++++++++++------------------------
rust/macros/lib.rs | 6 +-
2 files changed, 123 insertions(+), 157 deletions(-)
diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index 5cd6aa5eef07d..afbc708cbdc50 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -4,81 +4,50 @@
//!
//! Copyright (c) 2023 José Expósito <jose.exposito89@gmail.com>
-use std::collections::HashMap;
-use std::fmt::Write;
-
-use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
-
-pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
- let attr = attr.to_string();
-
- if attr.is_empty() {
- panic!("Missing test name in `#[kunit_tests(test_name)]` macro")
- }
-
- if attr.len() > 255 {
- panic!("The test suite name `{attr}` exceeds the maximum length of 255 bytes")
+use std::ffi::CString;
+
+use proc_macro2::TokenStream;
+use quote::{
+ format_ident,
+ quote,
+ ToTokens, //
+};
+use syn::{
+ parse_quote,
+ Error,
+ Ident,
+ Item,
+ ItemMod,
+ LitCStr,
+ Result, //
+};
+
+pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<TokenStream> {
+ if test_suite.to_string().len() > 255 {
+ return Err(Error::new_spanned(
+ test_suite,
+ "test suite names cannot exceed the maximum length of 255 bytes",
+ ));
}
- let mut tokens: Vec<_> = ts.into_iter().collect();
-
- // Scan for the `mod` keyword.
- tokens
- .iter()
- .find_map(|token| match token {
- TokenTree::Ident(ident) => match ident.to_string().as_str() {
- "mod" => Some(true),
- _ => None,
- },
- _ => None,
- })
- .expect("`#[kunit_tests(test_name)]` attribute should only be applied to modules");
-
- // Retrieve the main body. The main body should be the last token tree.
- let body = match tokens.pop() {
- Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group,
- _ => panic!("Cannot locate main body of module"),
+ // We cannot handle modules that defer to another file (e.g. `mod foo;`).
+ let Some((module_brace, module_items)) = module.content.take() else {
+ Err(Error::new_spanned(
+ module,
+ "`#[kunit_tests(test_name)]` attribute should only be applied to inline modules",
+ ))?
};
- // Get the functions set as tests. Search for `[test]` -> `fn`.
- let mut body_it = body.stream().into_iter();
- let mut tests = Vec::new();
- let mut attributes: HashMap<String, TokenStream> = HashMap::new();
- while let Some(token) = body_it.next() {
- match token {
- TokenTree::Punct(ref p) if p.as_char() == '#' => match body_it.next() {
- Some(TokenTree::Group(g)) if g.delimiter() == Delimiter::Bracket => {
- if let Some(TokenTree::Ident(name)) = g.stream().into_iter().next() {
- // Collect attributes because we need to find which are tests. We also
- // need to copy `cfg` attributes so tests can be conditionally enabled.
- attributes
- .entry(name.to_string())
- .or_default()
- .extend([token, TokenTree::Group(g)]);
- }
- continue;
- }
- _ => (),
- },
- TokenTree::Ident(i) if i == "fn" && attributes.contains_key("test") => {
- if let Some(TokenTree::Ident(test_name)) = body_it.next() {
- tests.push((test_name, attributes.remove("cfg").unwrap_or_default()))
- }
- }
-
- _ => (),
- }
- attributes.clear();
- }
+ // Make the entire module gated behind `CONFIG_KUNIT`.
+ module
+ .attrs
+ .insert(0, parse_quote!(#[cfg(CONFIG_KUNIT="y")]));
- // Add `#[cfg(CONFIG_KUNIT="y")]` before the module declaration.
- let config_kunit = "#[cfg(CONFIG_KUNIT=\"y\")]".to_owned().parse().unwrap();
- tokens.insert(
- 0,
- TokenTree::Group(Group::new(Delimiter::None, config_kunit)),
- );
+ let mut processed_items = Vec::new();
+ let mut test_cases = Vec::new();
// Generate the test KUnit test suite and a test case for each `#[test]`.
+ //
// The code generated for the following test module:
//
// ```
@@ -110,98 +79,93 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
//
// ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES);
// ```
- let mut kunit_macros = "".to_owned();
- let mut test_cases = "".to_owned();
- let mut assert_macros = "".to_owned();
- let path = crate::helpers::file();
- let num_tests = tests.len();
- for (test, cfg_attr) in tests {
- let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}");
- // Append any `cfg` attributes the user might have written on their tests so we don't
- // attempt to call them when they are `cfg`'d out. An extra `use` is used here to reduce
- // the length of the assert message.
- let kunit_wrapper = format!(
- r#"unsafe extern "C" fn {kunit_wrapper_fn_name}(_test: *mut ::kernel::bindings::kunit)
- {{
- (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SKIPPED;
- {cfg_attr} {{
- (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SUCCESS;
- use ::kernel::kunit::is_test_result_ok;
- assert!(is_test_result_ok({test}()));
+ //
+ // Non-function items (e.g. imports) are preserved.
+ for item in module_items {
+ let Item::Fn(mut f) = item else {
+ processed_items.push(item);
+ continue;
+ };
+
+ // TODO: Replace below with `extract_if` when MSRV is bumped above 1.85.
+ let before_len = f.attrs.len();
+ f.attrs.retain(|attr| !attr.path().is_ident("test"));
+ if f.attrs.len() == before_len {
+ processed_items.push(Item::Fn(f));
+ continue;
+ }
+
+ let test = f.sig.ident.clone();
+
+ // Retrieve `#[cfg]` applied on the function which needs to be present on derived items too.
+ let cfg_attrs: Vec<_> = f
+ .attrs
+ .iter()
+ .filter(|attr| attr.path().is_ident("cfg"))
+ .cloned()
+ .collect();
+
+ // Before the test, override usual `assert!` and `assert_eq!` macros with ones that call
+ // KUnit instead.
+ let test_str = test.to_string();
+ let path = crate::helpers::file();
+ processed_items.push(parse_quote! {
+ #[allow(unused)]
+ macro_rules! assert {
+ ($cond:expr $(,)?) => {{
+ kernel::kunit_assert!(#test_str, #path, 0, $cond);
+ }}
+ }
+ });
+ processed_items.push(parse_quote! {
+ #[allow(unused)]
+ macro_rules! assert_eq {
+ ($left:expr, $right:expr $(,)?) => {{
+ kernel::kunit_assert_eq!(#test_str, #path, 0, $left, $right);
}}
- }}"#,
+ }
+ });
+
+ // Add back the test item.
+ processed_items.push(Item::Fn(f));
+
+ let kunit_wrapper_fn_name = format_ident!("kunit_rust_wrapper_{test}");
+ let test_cstr = LitCStr::new(
+ &CString::new(test_str.as_str()).expect("identifier cannot contain NUL"),
+ test.span(),
);
- writeln!(kunit_macros, "{kunit_wrapper}").unwrap();
- writeln!(
- test_cases,
- " ::kernel::kunit::kunit_case(::kernel::c_str!(\"{test}\"), {kunit_wrapper_fn_name}),"
- )
- .unwrap();
- writeln!(
- assert_macros,
- r#"
-/// Overrides the usual [`assert!`] macro with one that calls KUnit instead.
-#[allow(unused)]
-macro_rules! assert {{
- ($cond:expr $(,)?) => {{{{
- kernel::kunit_assert!("{test}", "{path}", 0, $cond);
- }}}}
-}}
-
-/// Overrides the usual [`assert_eq!`] macro with one that calls KUnit instead.
-#[allow(unused)]
-macro_rules! assert_eq {{
- ($left:expr, $right:expr $(,)?) => {{{{
- kernel::kunit_assert_eq!("{test}", "{path}", 0, $left, $right);
- }}}}
-}}
- "#
- )
- .unwrap();
- }
+ processed_items.push(parse_quote! {
+ unsafe extern "C" fn #kunit_wrapper_fn_name(_test: *mut ::kernel::bindings::kunit) {
+ (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SKIPPED;
- writeln!(kunit_macros).unwrap();
- writeln!(
- kunit_macros,
- "static mut TEST_CASES: [::kernel::bindings::kunit_case; {}] = [\n{test_cases} ::kernel::kunit::kunit_case_null(),\n];",
- num_tests + 1
- )
- .unwrap();
-
- writeln!(
- kunit_macros,
- "::kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);"
- )
- .unwrap();
-
- // Remove the `#[test]` macros.
- // We do this at a token level, in order to preserve span information.
- let mut new_body = vec![];
- let mut body_it = body.stream().into_iter();
-
- while let Some(token) = body_it.next() {
- match token {
- TokenTree::Punct(ref c) if c.as_char() == '#' => match body_it.next() {
- Some(TokenTree::Group(group)) if group.to_string() == "[test]" => (),
- Some(next) => {
- new_body.extend([token, next]);
- }
- _ => {
- new_body.push(token);
+ // Append any `cfg` attributes the user might have written on their tests so we
+ // don't attempt to call them when they are `cfg`'d out. An extra `use` is used
+ // here to reduce the length of the assert message.
+ #(#cfg_attrs)*
+ {
+ (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SUCCESS;
+ use ::kernel::kunit::is_test_result_ok;
+ assert!(is_test_result_ok(#test()));
}
- },
- _ => {
- new_body.push(token);
}
- }
- }
+ });
- let mut final_body = TokenStream::new();
- final_body.extend::<TokenStream>(assert_macros.parse().unwrap());
- final_body.extend(new_body);
- final_body.extend::<TokenStream>(kunit_macros.parse().unwrap());
-
- tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, final_body)));
+ test_cases.push(quote!(
+ ::kernel::kunit::kunit_case(#test_cstr, #kunit_wrapper_fn_name)
+ ));
+ }
- tokens.into_iter().collect()
+ let num_tests_plus_1 = test_cases.len() + 1;
+ processed_items.push(parse_quote! {
+ static mut TEST_CASES: [::kernel::bindings::kunit_case; #num_tests_plus_1] = [
+ #(#test_cases,)*
+ ::kernel::kunit::kunit_case_null(),
+ ];
+ });
+ processed_items.push(parse_quote! {
+ ::kernel::kunit_unsafe_test_suite!(#test_suite, TEST_CASES);
+ });
+
+ module.content = Some((module_brace, processed_items));
+ Ok(module.to_token_stream())
}
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 12467bfc703a8..75ac60abe6ffa 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -481,6 +481,8 @@ pub fn paste(input: TokenStream) -> TokenStream {
/// }
/// ```
#[proc_macro_attribute]
-pub fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
- kunit::kunit_tests(attr.into(), ts.into()).into()
+pub fn kunit_tests(attr: TokenStream, input: TokenStream) -> TokenStream {
+ kunit::kunit_tests(parse_macro_input!(attr), parse_macro_input!(input))
+ .unwrap_or_else(|e| e.into_compile_error())
+ .into()
}
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro to use `syn`
2026-01-12 17:07 ` [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro " Gary Guo
@ 2026-01-17 20:09 ` Benno Lossin
2026-01-19 7:10 ` David Gow
1 sibling, 0 replies; 25+ messages in thread
From: Benno Lossin @ 2026-01-17 20:09 UTC (permalink / raw)
To: Gary Guo, Miguel Ojeda, Boqun Feng, Björn Roy Baron,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Brendan Higgins, David Gow, Rae Moar, Tamir Duberstein,
Igor Korotin, José Expósito
Cc: rust-for-linux, Guilherme Giacomo Simoes, linux-kselftest,
kunit-dev, linux-kernel
On Mon Jan 12, 2026 at 6:07 PM CET, Gary Guo wrote:
> From: Gary Guo <gary@garyguo.net>
>
> Make use of `syn` to parse the module structurally and thus improve the
> robustness of parsing.
>
> String interpolation is avoided by generating tokens directly using
> `quote!`.
>
> Reviewed-by: Tamir Duberstein <tamird@gmail.com>
> Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Cheers,
Benno
> ---
> rust/macros/kunit.rs | 274 +++++++++++++++++++------------------------
> rust/macros/lib.rs | 6 +-
> 2 files changed, 123 insertions(+), 157 deletions(-)
^ permalink raw reply [flat|nested] 25+ messages in thread
* Re: [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro to use `syn`
2026-01-12 17:07 ` [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro " Gary Guo
2026-01-17 20:09 ` Benno Lossin
@ 2026-01-19 7:10 ` David Gow
1 sibling, 0 replies; 25+ messages in thread
From: David Gow @ 2026-01-19 7:10 UTC (permalink / raw)
To: Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Brendan Higgins, Rae Moar, Tamir Duberstein, Igor Korotin,
José Expósito, rust-for-linux,
Guilherme Giacomo Simoes, linux-kselftest, kunit-dev,
linux-kernel
[-- Attachment #1: Type: text/plain, Size: 13793 bytes --]
On Tue, 13 Jan 2026 at 01:11, Gary Guo <gary@kernel.org> wrote:
>
> From: Gary Guo <gary@garyguo.net>
>
> Make use of `syn` to parse the module structurally and thus improve the
> robustness of parsing.
>
> String interpolation is avoided by generating tokens directly using
> `quote!`.
>
> Reviewed-by: Tamir Duberstein <tamird@gmail.com>
> Signed-off-by: Gary Guo <gary@garyguo.net>
> ---
Sorry this took so long to review: it's taken a while for me to wrap
my head around `syn`.
I'm pretty happy with this overall, though, and think I understand it
well enough now.
Reviewed-by: David Gow <davidgow@google.com>
Cheers,
-- David
> rust/macros/kunit.rs | 274 +++++++++++++++++++------------------------
> rust/macros/lib.rs | 6 +-
> 2 files changed, 123 insertions(+), 157 deletions(-)
>
> diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
> index 5cd6aa5eef07d..afbc708cbdc50 100644
> --- a/rust/macros/kunit.rs
> +++ b/rust/macros/kunit.rs
> @@ -4,81 +4,50 @@
> //!
> //! Copyright (c) 2023 José Expósito <jose.exposito89@gmail.com>
>
> -use std::collections::HashMap;
> -use std::fmt::Write;
> -
> -use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
> -
> -pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
> - let attr = attr.to_string();
> -
> - if attr.is_empty() {
> - panic!("Missing test name in `#[kunit_tests(test_name)]` macro")
> - }
I'm assuming it's okay for us to get rid of this as we get an
"unexpected end of input" error instead.
> -
> - if attr.len() > 255 {
> - panic!("The test suite name `{attr}` exceeds the maximum length of 255 bytes")
> +use std::ffi::CString;
> +
> +use proc_macro2::TokenStream;
> +use quote::{
> + format_ident,
> + quote,
> + ToTokens, //
> +};
> +use syn::{
> + parse_quote,
> + Error,
> + Ident,
> + Item,
> + ItemMod,
> + LitCStr,
> + Result, //
> +};
> +
> +pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<TokenStream> {
> + if test_suite.to_string().len() > 255 {
> + return Err(Error::new_spanned(
> + test_suite,
> + "test suite names cannot exceed the maximum length of 255 bytes",
> + ));
> }
>
> - let mut tokens: Vec<_> = ts.into_iter().collect();
> -
> - // Scan for the `mod` keyword.
> - tokens
> - .iter()
> - .find_map(|token| match token {
> - TokenTree::Ident(ident) => match ident.to_string().as_str() {
> - "mod" => Some(true),
> - _ => None,
> - },
> - _ => None,
> - })
> - .expect("`#[kunit_tests(test_name)]` attribute should only be applied to modules");
> -
> - // Retrieve the main body. The main body should be the last token tree.
> - let body = match tokens.pop() {
> - Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group,
> - _ => panic!("Cannot locate main body of module"),
> + // We cannot handle modules that defer to another file (e.g. `mod foo;`).
> + let Some((module_brace, module_items)) = module.content.take() else {
> + Err(Error::new_spanned(
> + module,
> + "`#[kunit_tests(test_name)]` attribute should only be applied to inline modules",
> + ))?
> };
>
> - // Get the functions set as tests. Search for `[test]` -> `fn`.
> - let mut body_it = body.stream().into_iter();
> - let mut tests = Vec::new();
> - let mut attributes: HashMap<String, TokenStream> = HashMap::new();
> - while let Some(token) = body_it.next() {
> - match token {
> - TokenTree::Punct(ref p) if p.as_char() == '#' => match body_it.next() {
> - Some(TokenTree::Group(g)) if g.delimiter() == Delimiter::Bracket => {
> - if let Some(TokenTree::Ident(name)) = g.stream().into_iter().next() {
> - // Collect attributes because we need to find which are tests. We also
> - // need to copy `cfg` attributes so tests can be conditionally enabled.
> - attributes
> - .entry(name.to_string())
> - .or_default()
> - .extend([token, TokenTree::Group(g)]);
> - }
> - continue;
> - }
> - _ => (),
> - },
> - TokenTree::Ident(i) if i == "fn" && attributes.contains_key("test") => {
> - if let Some(TokenTree::Ident(test_name)) = body_it.next() {
> - tests.push((test_name, attributes.remove("cfg").unwrap_or_default()))
> - }
> - }
> -
> - _ => (),
> - }
> - attributes.clear();
> - }
> + // Make the entire module gated behind `CONFIG_KUNIT`.
> + module
> + .attrs
> + .insert(0, parse_quote!(#[cfg(CONFIG_KUNIT="y")]));
>
> - // Add `#[cfg(CONFIG_KUNIT="y")]` before the module declaration.
> - let config_kunit = "#[cfg(CONFIG_KUNIT=\"y\")]".to_owned().parse().unwrap();
> - tokens.insert(
> - 0,
> - TokenTree::Group(Group::new(Delimiter::None, config_kunit)),
> - );
> + let mut processed_items = Vec::new();
> + let mut test_cases = Vec::new();
>
> // Generate the test KUnit test suite and a test case for each `#[test]`.
> + //
> // The code generated for the following test module:
> //
> // ```
> @@ -110,98 +79,93 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
> //
> // ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES);
> // ```
> - let mut kunit_macros = "".to_owned();
> - let mut test_cases = "".to_owned();
> - let mut assert_macros = "".to_owned();
> - let path = crate::helpers::file();
> - let num_tests = tests.len();
> - for (test, cfg_attr) in tests {
> - let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}");
> - // Append any `cfg` attributes the user might have written on their tests so we don't
> - // attempt to call them when they are `cfg`'d out. An extra `use` is used here to reduce
> - // the length of the assert message.
> - let kunit_wrapper = format!(
> - r#"unsafe extern "C" fn {kunit_wrapper_fn_name}(_test: *mut ::kernel::bindings::kunit)
> - {{
> - (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SKIPPED;
> - {cfg_attr} {{
> - (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SUCCESS;
> - use ::kernel::kunit::is_test_result_ok;
> - assert!(is_test_result_ok({test}()));
> + //
> + // Non-function items (e.g. imports) are preserved.
> + for item in module_items {
> + let Item::Fn(mut f) = item else {
> + processed_items.push(item);
> + continue;
> + };
> +
> + // TODO: Replace below with `extract_if` when MSRV is bumped above 1.85.
> + let before_len = f.attrs.len();
> + f.attrs.retain(|attr| !attr.path().is_ident("test"));
> + if f.attrs.len() == before_len {
> + processed_items.push(Item::Fn(f));
> + continue;
> + }
> +
> + let test = f.sig.ident.clone();
> +
> + // Retrieve `#[cfg]` applied on the function which needs to be present on derived items too.
> + let cfg_attrs: Vec<_> = f
> + .attrs
> + .iter()
> + .filter(|attr| attr.path().is_ident("cfg"))
> + .cloned()
> + .collect();
> +
> + // Before the test, override usual `assert!` and `assert_eq!` macros with ones that call
> + // KUnit instead.
> + let test_str = test.to_string();
> + let path = crate::helpers::file();
> + processed_items.push(parse_quote! {
> + #[allow(unused)]
> + macro_rules! assert {
> + ($cond:expr $(,)?) => {{
> + kernel::kunit_assert!(#test_str, #path, 0, $cond);
> + }}
> + }
> + });
> + processed_items.push(parse_quote! {
> + #[allow(unused)]
> + macro_rules! assert_eq {
> + ($left:expr, $right:expr $(,)?) => {{
> + kernel::kunit_assert_eq!(#test_str, #path, 0, $left, $right);
> }}
> - }}"#,
> + }
> + });
> +
> + // Add back the test item.
> + processed_items.push(Item::Fn(f));
> +
> + let kunit_wrapper_fn_name = format_ident!("kunit_rust_wrapper_{test}");
> + let test_cstr = LitCStr::new(
> + &CString::new(test_str.as_str()).expect("identifier cannot contain NUL"),
> + test.span(),
> );
> - writeln!(kunit_macros, "{kunit_wrapper}").unwrap();
> - writeln!(
> - test_cases,
> - " ::kernel::kunit::kunit_case(::kernel::c_str!(\"{test}\"), {kunit_wrapper_fn_name}),"
> - )
> - .unwrap();
> - writeln!(
> - assert_macros,
> - r#"
> -/// Overrides the usual [`assert!`] macro with one that calls KUnit instead.
> -#[allow(unused)]
> -macro_rules! assert {{
> - ($cond:expr $(,)?) => {{{{
> - kernel::kunit_assert!("{test}", "{path}", 0, $cond);
> - }}}}
> -}}
> -
> -/// Overrides the usual [`assert_eq!`] macro with one that calls KUnit instead.
> -#[allow(unused)]
> -macro_rules! assert_eq {{
> - ($left:expr, $right:expr $(,)?) => {{{{
> - kernel::kunit_assert_eq!("{test}", "{path}", 0, $left, $right);
> - }}}}
> -}}
> - "#
> - )
> - .unwrap();
> - }
> + processed_items.push(parse_quote! {
> + unsafe extern "C" fn #kunit_wrapper_fn_name(_test: *mut ::kernel::bindings::kunit) {
> + (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SKIPPED;
>
> - writeln!(kunit_macros).unwrap();
> - writeln!(
> - kunit_macros,
> - "static mut TEST_CASES: [::kernel::bindings::kunit_case; {}] = [\n{test_cases} ::kernel::kunit::kunit_case_null(),\n];",
> - num_tests + 1
> - )
> - .unwrap();
> -
> - writeln!(
> - kunit_macros,
> - "::kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);"
> - )
> - .unwrap();
> -
> - // Remove the `#[test]` macros.
> - // We do this at a token level, in order to preserve span information.
> - let mut new_body = vec![];
> - let mut body_it = body.stream().into_iter();
> -
> - while let Some(token) = body_it.next() {
> - match token {
> - TokenTree::Punct(ref c) if c.as_char() == '#' => match body_it.next() {
> - Some(TokenTree::Group(group)) if group.to_string() == "[test]" => (),
> - Some(next) => {
> - new_body.extend([token, next]);
> - }
> - _ => {
> - new_body.push(token);
> + // Append any `cfg` attributes the user might have written on their tests so we
> + // don't attempt to call them when they are `cfg`'d out. An extra `use` is used
> + // here to reduce the length of the assert message.
> + #(#cfg_attrs)*
> + {
> + (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SUCCESS;
> + use ::kernel::kunit::is_test_result_ok;
> + assert!(is_test_result_ok(#test()));
> }
> - },
> - _ => {
> - new_body.push(token);
> }
> - }
> - }
> + });
>
> - let mut final_body = TokenStream::new();
> - final_body.extend::<TokenStream>(assert_macros.parse().unwrap());
> - final_body.extend(new_body);
> - final_body.extend::<TokenStream>(kunit_macros.parse().unwrap());
> -
> - tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, final_body)));
> + test_cases.push(quote!(
> + ::kernel::kunit::kunit_case(#test_cstr, #kunit_wrapper_fn_name)
> + ));
> + }
>
> - tokens.into_iter().collect()
> + let num_tests_plus_1 = test_cases.len() + 1;
> + processed_items.push(parse_quote! {
> + static mut TEST_CASES: [::kernel::bindings::kunit_case; #num_tests_plus_1] = [
> + #(#test_cases,)*
> + ::kernel::kunit::kunit_case_null(),
> + ];
> + });
> + processed_items.push(parse_quote! {
> + ::kernel::kunit_unsafe_test_suite!(#test_suite, TEST_CASES);
> + });
> +
> + module.content = Some((module_brace, processed_items));
> + Ok(module.to_token_stream())
> }
> diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
> index 12467bfc703a8..75ac60abe6ffa 100644
> --- a/rust/macros/lib.rs
> +++ b/rust/macros/lib.rs
> @@ -481,6 +481,8 @@ pub fn paste(input: TokenStream) -> TokenStream {
> /// }
> /// ```
> #[proc_macro_attribute]
> -pub fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream {
> - kunit::kunit_tests(attr.into(), ts.into()).into()
> +pub fn kunit_tests(attr: TokenStream, input: TokenStream) -> TokenStream {
> + kunit::kunit_tests(parse_macro_input!(attr), parse_macro_input!(input))
> + .unwrap_or_else(|e| e.into_compile_error())
> + .into()
> }
> --
> 2.51.2
>
[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 5281 bytes --]
^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v3 09/12] rust: macros: allow arbitrary types to be used in `module!` macro
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (7 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 08/12] rust: macros: convert `#[kunit_tests]` macro " Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:07 ` [PATCH v3 10/12] rust: macros: rearrange `#[doc(hidden)]` " Gary Guo
` (2 subsequent siblings)
11 siblings, 0 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin
Cc: rust-for-linux, linux-modules, linux-kernel
From: Gary Guo <gary@garyguo.net>
Previously this only accepts an identifier, but now with `syn` it is
easy to make it accepts any type.
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/module.rs | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 43ada49525c9d..9e0242d42d51f 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -26,7 +26,8 @@
LitStr,
Path,
Result,
- Token, //
+ Token,
+ Type, //
};
use crate::helpers::*;
@@ -370,7 +371,7 @@ fn parse(input: ParseStream<'_>) -> Result<Self> {
}
pub(crate) struct ModuleInfo {
- type_: Ident,
+ type_: Type,
license: AsciiLitStr,
name: AsciiLitStr,
authors: Option<Punctuated<AsciiLitStr, Token![,]>>,
@@ -529,7 +530,6 @@ impl ::kernel::ModuleMetadata for #type_ {
// Double nested modules, since then nobody can access the public items inside.
mod __module_init {
mod __module_init {
- use super::super::#type_;
use pin_init::PinInit;
/// The "Rust loadable module" mark.
@@ -541,7 +541,7 @@ mod __module_init {
#[used(compiler)]
static __IS_RUST_MODULE: () = ();
- static mut __MOD: ::core::mem::MaybeUninit<#type_> =
+ static mut __MOD: ::core::mem::MaybeUninit<super::super::LocalModule> =
::core::mem::MaybeUninit::uninit();
// Loadable modules need to export the `{init,cleanup}_module` identifiers.
@@ -628,8 +628,9 @@ pub extern "C" fn #ident_exit() {
///
/// This function must only be called once.
unsafe fn __init() -> ::kernel::ffi::c_int {
- let initer =
- <#type_ as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
+ let initer = <super::super::LocalModule as ::kernel::InPlaceModule>::init(
+ &super::super::THIS_MODULE
+ );
// SAFETY: No data race, since `__MOD` can only be accessed by this module
// and there only `__init` and `__exit` access it. These functions are only
// called once and `__exit` cannot be called before or during `__init`.
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v3 10/12] rust: macros: rearrange `#[doc(hidden)]` in `module!` macro
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (8 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 09/12] rust: macros: allow arbitrary types to be used in `module!` macro Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:07 ` [PATCH v3 11/12] rust: kunit: use `pin_init::zeroed` instead of custom null value Gary Guo
2026-01-12 17:07 ` [PATCH v3 12/12] rust: macros: support `#[cfg]` properly in `#[vtable]` macro Gary Guo
11 siblings, 0 replies; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Luis Chamberlain, Petr Pavlu, Daniel Gomez,
Sami Tolvanen, Aaron Tomlin
Cc: rust-for-linux, Tamir Duberstein, linux-modules, linux-kernel
From: Gary Guo <gary@garyguo.net>
This `#[doc(hidden)]` can just be applied on a module to hide anything
within.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/module.rs | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 9e0242d42d51f..e16298e520c78 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -77,7 +77,6 @@ fn emit_base(&mut self, field: &str, content: &str, builtin: bool, param: bool)
);
let item = quote! {
#cfg
- #[doc(hidden)]
#[cfg_attr(not(target_os = "macos"), link_section = ".modinfo")]
#[used(compiler)]
pub static #counter: [u8; #length] = *#string;
@@ -528,6 +527,7 @@ impl ::kernel::ModuleMetadata for #type_ {
}
// Double nested modules, since then nobody can access the public items inside.
+ #[doc(hidden)]
mod __module_init {
mod __module_init {
use pin_init::PinInit;
@@ -537,7 +537,6 @@ mod __module_init {
// This may be best done another way later on, e.g. as a new modinfo
// key or a new section. For the moment, keep it simple.
#[cfg(MODULE)]
- #[doc(hidden)]
#[used(compiler)]
static __IS_RUST_MODULE: () = ();
@@ -550,7 +549,6 @@ mod __module_init {
/// This function must not be called after module initialization, because it may be
/// freed after that completes.
#[cfg(MODULE)]
- #[doc(hidden)]
#[no_mangle]
#[link_section = ".init.text"]
pub unsafe extern "C" fn init_module() -> ::kernel::ffi::c_int {
@@ -561,14 +559,12 @@ mod __module_init {
}
#[cfg(MODULE)]
- #[doc(hidden)]
#[used(compiler)]
#[link_section = ".init.data"]
static __UNIQUE_ID___addressable_init_module: unsafe extern "C" fn() -> i32 =
init_module;
#[cfg(MODULE)]
- #[doc(hidden)]
#[no_mangle]
#[link_section = ".exit.text"]
pub extern "C" fn cleanup_module() {
@@ -582,7 +578,6 @@ pub extern "C" fn cleanup_module() {
}
#[cfg(MODULE)]
- #[doc(hidden)]
#[used(compiler)]
#[link_section = ".exit.data"]
static __UNIQUE_ID___addressable_cleanup_module: extern "C" fn() = cleanup_module;
@@ -591,7 +586,6 @@ pub extern "C" fn cleanup_module() {
// and the identifiers need to be unique.
#[cfg(not(MODULE))]
#[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
- #[doc(hidden)]
#[link_section = #initcall_section]
#[used(compiler)]
pub static #ident_initcall: extern "C" fn() ->
@@ -602,7 +596,6 @@ pub extern "C" fn cleanup_module() {
::core::arch::global_asm!(#global_asm);
#[cfg(not(MODULE))]
- #[doc(hidden)]
#[no_mangle]
pub extern "C" fn #ident_init() -> ::kernel::ffi::c_int {
// SAFETY: This function is inaccessible to the outside due to the double
@@ -612,7 +605,6 @@ pub extern "C" fn #ident_init() -> ::kernel::ffi::c_int {
}
#[cfg(not(MODULE))]
- #[doc(hidden)]
#[no_mangle]
pub extern "C" fn #ident_exit() {
// SAFETY:
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v3 11/12] rust: kunit: use `pin_init::zeroed` instead of custom null value
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (9 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 10/12] rust: macros: rearrange `#[doc(hidden)]` " Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-19 7:10 ` David Gow
2026-01-12 17:07 ` [PATCH v3 12/12] rust: macros: support `#[cfg]` properly in `#[vtable]` macro Gary Guo
11 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Brendan Higgins, David Gow, Rae Moar
Cc: rust-for-linux, Tamir Duberstein, linux-kselftest, kunit-dev,
linux-kernel
From: Gary Guo <gary@garyguo.net>
The last null element can be created (constly) using `pin_init::zeroed`,
so prefer to use it instead of adding a custom way of building it.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/kernel/kunit.rs | 26 +-------------------------
rust/macros/kunit.rs | 4 ++--
2 files changed, 3 insertions(+), 27 deletions(-)
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
index 79436509dd73d..034158cdaf06b 100644
--- a/rust/kernel/kunit.rs
+++ b/rust/kernel/kunit.rs
@@ -192,9 +192,6 @@ pub fn is_test_result_ok(t: impl TestResult) -> bool {
}
/// Represents an individual test case.
-///
-/// The [`kunit_unsafe_test_suite!`] macro expects a NULL-terminated list of valid test cases.
-/// Use [`kunit_case_null`] to generate such a delimiter.
#[doc(hidden)]
pub const fn kunit_case(
name: &'static kernel::str::CStr,
@@ -215,27 +212,6 @@ pub const fn kunit_case(
}
}
-/// Represents the NULL test case delimiter.
-///
-/// The [`kunit_unsafe_test_suite!`] macro expects a NULL-terminated list of test cases. This
-/// function returns such a delimiter.
-#[doc(hidden)]
-pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
- kernel::bindings::kunit_case {
- run_case: None,
- name: core::ptr::null_mut(),
- generate_params: None,
- attr: kernel::bindings::kunit_attributes {
- speed: kernel::bindings::kunit_speed_KUNIT_SPEED_NORMAL,
- },
- status: kernel::bindings::kunit_status_KUNIT_SUCCESS,
- module_name: core::ptr::null_mut(),
- log: core::ptr::null_mut(),
- param_init: None,
- param_exit: None,
- }
-}
-
/// Registers a KUnit test suite.
///
/// # Safety
@@ -254,7 +230,7 @@ pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
///
/// static mut KUNIT_TEST_CASES: [kernel::bindings::kunit_case; 2] = [
/// kernel::kunit::kunit_case(kernel::c_str!("name"), test_fn),
-/// kernel::kunit::kunit_case_null(),
+/// pin_init::zeroed(),
/// ];
/// kernel::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES);
/// ```
diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
index afbc708cbdc50..cb29f350d5b2b 100644
--- a/rust/macros/kunit.rs
+++ b/rust/macros/kunit.rs
@@ -74,7 +74,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
// static mut TEST_CASES: [::kernel::bindings::kunit_case; 3] = [
// ::kernel::kunit::kunit_case(::kernel::c_str!("foo"), kunit_rust_wrapper_foo),
// ::kernel::kunit::kunit_case(::kernel::c_str!("bar"), kunit_rust_wrapper_bar),
- // ::kernel::kunit::kunit_case_null(),
+ // ::pin_init::zeroed(),
// ];
//
// ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES);
@@ -159,7 +159,7 @@ macro_rules! assert_eq {
processed_items.push(parse_quote! {
static mut TEST_CASES: [::kernel::bindings::kunit_case; #num_tests_plus_1] = [
#(#test_cases,)*
- ::kernel::kunit::kunit_case_null(),
+ ::pin_init::zeroed(),
];
});
processed_items.push(parse_quote! {
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v3 11/12] rust: kunit: use `pin_init::zeroed` instead of custom null value
2026-01-12 17:07 ` [PATCH v3 11/12] rust: kunit: use `pin_init::zeroed` instead of custom null value Gary Guo
@ 2026-01-19 7:10 ` David Gow
0 siblings, 0 replies; 25+ messages in thread
From: David Gow @ 2026-01-19 7:10 UTC (permalink / raw)
To: Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Brendan Higgins, Rae Moar, rust-for-linux, Tamir Duberstein,
linux-kselftest, kunit-dev, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 3693 bytes --]
On Tue, 13 Jan 2026 at 01:12, Gary Guo <gary@kernel.org> wrote:
>
> From: Gary Guo <gary@garyguo.net>
>
> The last null element can be created (constly) using `pin_init::zeroed`,
> so prefer to use it instead of adding a custom way of building it.
>
> Reviewed-by: Tamir Duberstein <tamird@gmail.com>
> Reviewed-by: Benno Lossin <lossin@kernel.org>
> Signed-off-by: Gary Guo <gary@garyguo.net>
> ---
Reviewed-by: David Gow <davidgow@google.com>
(Do note, however, that this conflicts with
https://lore.kernel.org/rust-for-linux/20251130211233.367946-1-seimun018r@gmail.com/)
Cheers,
-- David
> rust/kernel/kunit.rs | 26 +-------------------------
> rust/macros/kunit.rs | 4 ++--
> 2 files changed, 3 insertions(+), 27 deletions(-)
>
> diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
> index 79436509dd73d..034158cdaf06b 100644
> --- a/rust/kernel/kunit.rs
> +++ b/rust/kernel/kunit.rs
> @@ -192,9 +192,6 @@ pub fn is_test_result_ok(t: impl TestResult) -> bool {
> }
>
> /// Represents an individual test case.
> -///
> -/// The [`kunit_unsafe_test_suite!`] macro expects a NULL-terminated list of valid test cases.
> -/// Use [`kunit_case_null`] to generate such a delimiter.
> #[doc(hidden)]
> pub const fn kunit_case(
> name: &'static kernel::str::CStr,
> @@ -215,27 +212,6 @@ pub const fn kunit_case(
> }
> }
>
> -/// Represents the NULL test case delimiter.
> -///
> -/// The [`kunit_unsafe_test_suite!`] macro expects a NULL-terminated list of test cases. This
> -/// function returns such a delimiter.
> -#[doc(hidden)]
> -pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
> - kernel::bindings::kunit_case {
> - run_case: None,
> - name: core::ptr::null_mut(),
> - generate_params: None,
> - attr: kernel::bindings::kunit_attributes {
> - speed: kernel::bindings::kunit_speed_KUNIT_SPEED_NORMAL,
> - },
> - status: kernel::bindings::kunit_status_KUNIT_SUCCESS,
> - module_name: core::ptr::null_mut(),
> - log: core::ptr::null_mut(),
> - param_init: None,
> - param_exit: None,
> - }
> -}
> -
> /// Registers a KUnit test suite.
> ///
> /// # Safety
> @@ -254,7 +230,7 @@ pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
> ///
> /// static mut KUNIT_TEST_CASES: [kernel::bindings::kunit_case; 2] = [
> /// kernel::kunit::kunit_case(kernel::c_str!("name"), test_fn),
> -/// kernel::kunit::kunit_case_null(),
> +/// pin_init::zeroed(),
> /// ];
> /// kernel::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES);
> /// ```
> diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs
> index afbc708cbdc50..cb29f350d5b2b 100644
> --- a/rust/macros/kunit.rs
> +++ b/rust/macros/kunit.rs
> @@ -74,7 +74,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
> // static mut TEST_CASES: [::kernel::bindings::kunit_case; 3] = [
> // ::kernel::kunit::kunit_case(::kernel::c_str!("foo"), kunit_rust_wrapper_foo),
> // ::kernel::kunit::kunit_case(::kernel::c_str!("bar"), kunit_rust_wrapper_bar),
> - // ::kernel::kunit::kunit_case_null(),
> + // ::pin_init::zeroed(),
> // ];
> //
> // ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES);
> @@ -159,7 +159,7 @@ macro_rules! assert_eq {
> processed_items.push(parse_quote! {
> static mut TEST_CASES: [::kernel::bindings::kunit_case; #num_tests_plus_1] = [
> #(#test_cases,)*
> - ::kernel::kunit::kunit_case_null(),
> + ::pin_init::zeroed(),
> ];
> });
> processed_items.push(parse_quote! {
> --
> 2.51.2
>
[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 5281 bytes --]
^ permalink raw reply [flat|nested] 25+ messages in thread
* [PATCH v3 12/12] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
[not found] <20260112170919.1888584-1-gary@kernel.org>
` (10 preceding siblings ...)
2026-01-12 17:07 ` [PATCH v3 11/12] rust: kunit: use `pin_init::zeroed` instead of custom null value Gary Guo
@ 2026-01-12 17:07 ` Gary Guo
2026-01-12 17:48 ` Tamir Duberstein
11 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-12 17:07 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Tamir Duberstein
Cc: rust-for-linux, linux-kernel
From: Gary Guo <gary@garyguo.net>
Currently, we generate `HAS_` constants as long as the definition exists in
the source, regardless if it is cfg-ed out or not.
Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
will incorrectly be true while it shouldnt't.
With `syn` support, we can now implement `#[cfg]` handling properly by
propagating the `#[cfg]` attributes to the constants.
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/helpers.rs | 9 +++++++++
rust/macros/vtable.rs | 13 ++++---------
2 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index adfa60d8f42d8..c17287da801dd 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -7,6 +7,7 @@
Parse,
ParseStream, //
},
+ Attribute,
Error,
LitStr,
Result, //
@@ -53,3 +54,11 @@ pub(crate) fn file() -> String {
proc_macro::Span::call_site().file()
}
}
+
+/// Obtain all `#[cfg]` attributes.
+pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> Vec<Attribute> {
+ attr.iter()
+ .filter(|a| a.path().is_ident("cfg"))
+ .cloned()
+ .collect()
+}
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
index 72ae0a1816a04..c6510b0c4ea1d 100644
--- a/rust/macros/vtable.rs
+++ b/rust/macros/vtable.rs
@@ -23,7 +23,6 @@
fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
let mut gen_items = Vec::new();
- let mut gen_consts = HashSet::new();
gen_items.push(parse_quote! {
/// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
@@ -38,22 +37,17 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
&format!("HAS_{}", name.to_string().to_uppercase()),
name.span(),
);
- // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
- // define functions.
- // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
- if gen_consts.contains(&gen_const_name) {
- continue;
- }
// We don't know on the implementation-site whether a method is required or provided
// so we have to generate a const for all methods.
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
let comment =
format!("Indicates if the `{name}` method is overridden by the implementor.");
gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
#[doc = #comment]
const #gen_const_name: bool = false;
});
- gen_consts.insert(gen_const_name);
}
}
@@ -87,10 +81,11 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
if defined_consts.contains(&gen_const_name) {
continue;
}
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
const #gen_const_name: bool = true;
});
- defined_consts.insert(gen_const_name);
}
}
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v3 12/12] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-12 17:07 ` [PATCH v3 12/12] rust: macros: support `#[cfg]` properly in `#[vtable]` macro Gary Guo
@ 2026-01-12 17:48 ` Tamir Duberstein
2026-01-13 13:11 ` [PATCH] " Gary Guo
0 siblings, 1 reply; 25+ messages in thread
From: Tamir Duberstein @ 2026-01-12 17:48 UTC (permalink / raw)
To: Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
rust-for-linux, linux-kernel
On Mon, Jan 12, 2026 at 12:12 PM Gary Guo <gary@kernel.org> wrote:
>
> From: Gary Guo <gary@garyguo.net>
>
> Currently, we generate `HAS_` constants as long as the definition exists in
> the source, regardless if it is cfg-ed out or not.
>
> Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
> problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
> will incorrectly be true while it shouldnt't.
>
> With `syn` support, we can now implement `#[cfg]` handling properly by
> propagating the `#[cfg]` attributes to the constants.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>
> ---
> rust/macros/helpers.rs | 9 +++++++++
> rust/macros/vtable.rs | 13 ++++---------
> 2 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
> index adfa60d8f42d8..c17287da801dd 100644
> --- a/rust/macros/helpers.rs
> +++ b/rust/macros/helpers.rs
> @@ -7,6 +7,7 @@
> Parse,
> ParseStream, //
> },
> + Attribute,
> Error,
> LitStr,
> Result, //
> @@ -53,3 +54,11 @@ pub(crate) fn file() -> String {
> proc_macro::Span::call_site().file()
> }
> }
> +
> +/// Obtain all `#[cfg]` attributes.
> +pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> Vec<Attribute> {
> + attr.iter()
> + .filter(|a| a.path().is_ident("cfg"))
> + .cloned()
> + .collect()
> +}
I believe there's no need to collect this into a vector, `quote`
supports iterators.
https://docs.rs/quote/latest/quote/macro.quote.html#interpolation
> diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
> index 72ae0a1816a04..c6510b0c4ea1d 100644
> --- a/rust/macros/vtable.rs
> +++ b/rust/macros/vtable.rs
> @@ -23,7 +23,6 @@
>
> fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
> let mut gen_items = Vec::new();
> - let mut gen_consts = HashSet::new();
>
> gen_items.push(parse_quote! {
> /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
> @@ -38,22 +37,17 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
> &format!("HAS_{}", name.to_string().to_uppercase()),
> name.span(),
> );
> - // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
> - // define functions.
> - // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
> - if gen_consts.contains(&gen_const_name) {
> - continue;
> - }
>
> // We don't know on the implementation-site whether a method is required or provided
> // so we have to generate a const for all methods.
> + let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
> let comment =
> format!("Indicates if the `{name}` method is overridden by the implementor.");
> gen_items.push(parse_quote! {
> + #(#cfg_attrs)*
> #[doc = #comment]
> const #gen_const_name: bool = false;
> });
> - gen_consts.insert(gen_const_name);
> }
> }
>
> @@ -87,10 +81,11 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
> if defined_consts.contains(&gen_const_name) {
> continue;
> }
> + let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
> gen_items.push(parse_quote! {
> + #(#cfg_attrs)*
> const #gen_const_name: bool = true;
> });
> - defined_consts.insert(gen_const_name);
> }
> }
>
> --
> 2.51.2
>
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-12 17:48 ` Tamir Duberstein
@ 2026-01-13 13:11 ` Gary Guo
2026-01-13 13:39 ` Tamir Duberstein
0 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-13 13:11 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Tamir Duberstein
Cc: rust-for-linux, linux-kernel
From: Gary Guo <gary@garyguo.net>
Currently, we generate `HAS_` constants as long as the definition exists in
the source, regardless if it is cfg-ed out or not.
Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
will incorrectly be true while it shouldnt't.
With `syn` support, we can now implement `#[cfg]` handling properly by
propagating the `#[cfg]` attributes to the constants.
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/helpers.rs | 6 ++++++
rust/macros/vtable.rs | 13 ++++---------
2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index adfa60d8f42d8..11117b4c95d25 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -7,6 +7,7 @@
Parse,
ParseStream, //
},
+ Attribute,
Error,
LitStr,
Result, //
@@ -53,3 +54,8 @@ pub(crate) fn file() -> String {
proc_macro::Span::call_site().file()
}
}
+
+/// Obtain all `#[cfg]` attributes.
+pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> impl Iterator<Item = Attribute> + '_ {
+ attr.iter().filter(|a| a.path().is_ident("cfg")).cloned()
+}
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
index 72ae0a1816a04..c6510b0c4ea1d 100644
--- a/rust/macros/vtable.rs
+++ b/rust/macros/vtable.rs
@@ -23,7 +23,6 @@
fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
let mut gen_items = Vec::new();
- let mut gen_consts = HashSet::new();
gen_items.push(parse_quote! {
/// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
@@ -38,22 +37,17 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
&format!("HAS_{}", name.to_string().to_uppercase()),
name.span(),
);
- // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
- // define functions.
- // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
- if gen_consts.contains(&gen_const_name) {
- continue;
- }
// We don't know on the implementation-site whether a method is required or provided
// so we have to generate a const for all methods.
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
let comment =
format!("Indicates if the `{name}` method is overridden by the implementor.");
gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
#[doc = #comment]
const #gen_const_name: bool = false;
});
- gen_consts.insert(gen_const_name);
}
}
@@ -87,10 +81,11 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
if defined_consts.contains(&gen_const_name) {
continue;
}
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
const #gen_const_name: bool = true;
});
- defined_consts.insert(gen_const_name);
}
}
base-commit: 761e1fbc67b122bfe3d58518a9ea9ee668962c92
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-13 13:11 ` [PATCH] " Gary Guo
@ 2026-01-13 13:39 ` Tamir Duberstein
2026-01-13 14:09 ` Gary Guo
0 siblings, 1 reply; 25+ messages in thread
From: Tamir Duberstein @ 2026-01-13 13:39 UTC (permalink / raw)
To: Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
rust-for-linux, linux-kernel
On Tue, Jan 13, 2026 at 8:11 AM Gary Guo <gary@kernel.org> wrote:
>
> From: Gary Guo <gary@garyguo.net>
>
> Currently, we generate `HAS_` constants as long as the definition exists in
> the source, regardless if it is cfg-ed out or not.
>
> Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
> problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
> will incorrectly be true while it shouldnt't.
>
> With `syn` support, we can now implement `#[cfg]` handling properly by
> propagating the `#[cfg]` attributes to the constants.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>
> ---
> rust/macros/helpers.rs | 6 ++++++
> rust/macros/vtable.rs | 13 ++++---------
> 2 files changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
> index adfa60d8f42d8..11117b4c95d25 100644
> --- a/rust/macros/helpers.rs
> +++ b/rust/macros/helpers.rs
> @@ -7,6 +7,7 @@
> Parse,
> ParseStream, //
> },
> + Attribute,
> Error,
> LitStr,
> Result, //
> @@ -53,3 +54,8 @@ pub(crate) fn file() -> String {
> proc_macro::Span::call_site().file()
> }
> }
> +
> +/// Obtain all `#[cfg]` attributes.
> +pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> impl Iterator<Item = Attribute> + '_ {
> + attr.iter().filter(|a| a.path().is_ident("cfg")).cloned()
> +}
There's also no need to clone; `ToTokens::to_tokens` takes `&self`.
https://docs.rs/quote/latest/quote/trait.ToTokens.html#tymethod.to_tokens
> diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
> index 72ae0a1816a04..c6510b0c4ea1d 100644
> --- a/rust/macros/vtable.rs
> +++ b/rust/macros/vtable.rs
> @@ -23,7 +23,6 @@
>
> fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
> let mut gen_items = Vec::new();
> - let mut gen_consts = HashSet::new();
>
> gen_items.push(parse_quote! {
> /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
> @@ -38,22 +37,17 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
> &format!("HAS_{}", name.to_string().to_uppercase()),
> name.span(),
> );
> - // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
> - // define functions.
> - // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
> - if gen_consts.contains(&gen_const_name) {
> - continue;
> - }
>
> // We don't know on the implementation-site whether a method is required or provided
> // so we have to generate a const for all methods.
> + let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
> let comment =
> format!("Indicates if the `{name}` method is overridden by the implementor.");
> gen_items.push(parse_quote! {
> + #(#cfg_attrs)*
> #[doc = #comment]
> const #gen_const_name: bool = false;
> });
> - gen_consts.insert(gen_const_name);
> }
> }
>
> @@ -87,10 +81,11 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
> if defined_consts.contains(&gen_const_name) {
> continue;
> }
> + let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
> gen_items.push(parse_quote! {
> + #(#cfg_attrs)*
> const #gen_const_name: bool = true;
> });
> - defined_consts.insert(gen_const_name);
> }
> }
>
>
> base-commit: 761e1fbc67b122bfe3d58518a9ea9ee668962c92
> --
> 2.51.2
>
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-13 13:39 ` Tamir Duberstein
@ 2026-01-13 14:09 ` Gary Guo
2026-01-13 14:23 ` Tamir Duberstein
0 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-13 14:09 UTC (permalink / raw)
To: Tamir Duberstein, Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
rust-for-linux, linux-kernel
On Tue Jan 13, 2026 at 1:39 PM GMT, Tamir Duberstein wrote:
> On Tue, Jan 13, 2026 at 8:11 AM Gary Guo <gary@kernel.org> wrote:
>>
>> From: Gary Guo <gary@garyguo.net>
>>
>> Currently, we generate `HAS_` constants as long as the definition exists in
>> the source, regardless if it is cfg-ed out or not.
>>
>> Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
>> problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
>> will incorrectly be true while it shouldnt't.
>>
>> With `syn` support, we can now implement `#[cfg]` handling properly by
>> propagating the `#[cfg]` attributes to the constants.
>>
>> Signed-off-by: Gary Guo <gary@garyguo.net>
>> ---
>> rust/macros/helpers.rs | 6 ++++++
>> rust/macros/vtable.rs | 13 ++++---------
>> 2 files changed, 10 insertions(+), 9 deletions(-)
>>
>> diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
>> index adfa60d8f42d8..11117b4c95d25 100644
>> --- a/rust/macros/helpers.rs
>> +++ b/rust/macros/helpers.rs
>> @@ -7,6 +7,7 @@
>> Parse,
>> ParseStream, //
>> },
>> + Attribute,
>> Error,
>> LitStr,
>> Result, //
>> @@ -53,3 +54,8 @@ pub(crate) fn file() -> String {
>> proc_macro::Span::call_site().file()
>> }
>> }
>> +
>> +/// Obtain all `#[cfg]` attributes.
>> +pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> impl Iterator<Item = Attribute> + '_ {
>> + attr.iter().filter(|a| a.path().is_ident("cfg")).cloned()
>> +}
>
> There's also no need to clone; `ToTokens::to_tokens` takes `&self`.
>
> https://docs.rs/quote/latest/quote/trait.ToTokens.html#tymethod.to_tokens
Indeed. In that case I feel like the line is short enough and we can just inline
these and skip the helper function?
Best,
Gary
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-13 14:09 ` Gary Guo
@ 2026-01-13 14:23 ` Tamir Duberstein
2026-01-13 17:05 ` [PATCH v2] " Gary Guo
0 siblings, 1 reply; 25+ messages in thread
From: Tamir Duberstein @ 2026-01-13 14:23 UTC (permalink / raw)
To: Gary Guo
Cc: Miguel Ojeda, Boqun Feng, Björn Roy Baron, Benno Lossin,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
rust-for-linux, linux-kernel
On Tue, Jan 13, 2026 at 9:09 AM Gary Guo <gary@garyguo.net> wrote:
>
> On Tue Jan 13, 2026 at 1:39 PM GMT, Tamir Duberstein wrote:
> > On Tue, Jan 13, 2026 at 8:11 AM Gary Guo <gary@kernel.org> wrote:
> >>
> >> From: Gary Guo <gary@garyguo.net>
> >>
> >> Currently, we generate `HAS_` constants as long as the definition exists in
> >> the source, regardless if it is cfg-ed out or not.
> >>
> >> Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
> >> problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
> >> will incorrectly be true while it shouldnt't.
> >>
> >> With `syn` support, we can now implement `#[cfg]` handling properly by
> >> propagating the `#[cfg]` attributes to the constants.
> >>
> >> Signed-off-by: Gary Guo <gary@garyguo.net>
> >> ---
> >> rust/macros/helpers.rs | 6 ++++++
> >> rust/macros/vtable.rs | 13 ++++---------
> >> 2 files changed, 10 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
> >> index adfa60d8f42d8..11117b4c95d25 100644
> >> --- a/rust/macros/helpers.rs
> >> +++ b/rust/macros/helpers.rs
> >> @@ -7,6 +7,7 @@
> >> Parse,
> >> ParseStream, //
> >> },
> >> + Attribute,
> >> Error,
> >> LitStr,
> >> Result, //
> >> @@ -53,3 +54,8 @@ pub(crate) fn file() -> String {
> >> proc_macro::Span::call_site().file()
> >> }
> >> }
> >> +
> >> +/// Obtain all `#[cfg]` attributes.
> >> +pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> impl Iterator<Item = Attribute> + '_ {
> >> + attr.iter().filter(|a| a.path().is_ident("cfg")).cloned()
> >> +}
> >
> > There's also no need to clone; `ToTokens::to_tokens` takes `&self`.
> >
> > https://docs.rs/quote/latest/quote/trait.ToTokens.html#tymethod.to_tokens
>
> Indeed. In that case I feel like the line is short enough and we can just inline
> these and skip the helper function?
I think extracting the duplication is still worthwhile, and we might
need this elsewhere so I'd leave it in the helpers module. I don't
feel strongly though, so go with your preference.
>
> Best,
> Gary
^ permalink raw reply [flat|nested] 25+ messages in thread* [PATCH v2] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-13 14:23 ` Tamir Duberstein
@ 2026-01-13 17:05 ` Gary Guo
2026-01-17 20:09 ` Benno Lossin
0 siblings, 1 reply; 25+ messages in thread
From: Gary Guo @ 2026-01-13 17:05 UTC (permalink / raw)
To: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Alice Ryhl, Trevor Gross,
Danilo Krummrich, Tamir Duberstein
Cc: rust-for-linux, linux-kernel
From: Gary Guo <gary@garyguo.net>
Currently, we generate `HAS_` constants as long as the definition exists in
the source, regardless if it is cfg-ed out or not.
Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
will incorrectly be true while it shouldnt't.
With `syn` support, we can now implement `#[cfg]` handling properly by
propagating the `#[cfg]` attributes to the constants.
Signed-off-by: Gary Guo <gary@garyguo.net>
---
rust/macros/helpers.rs | 6 ++++++
rust/macros/vtable.rs | 13 ++++---------
2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index adfa60d8f42d8..37ef6a6f2c851 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -7,6 +7,7 @@
Parse,
ParseStream, //
},
+ Attribute,
Error,
LitStr,
Result, //
@@ -53,3 +54,8 @@ pub(crate) fn file() -> String {
proc_macro::Span::call_site().file()
}
}
+
+/// Obtain all `#[cfg]` attributes.
+pub(crate) fn gather_cfg_attrs(attr: &[Attribute]) -> impl Iterator<Item = &Attribute> + '_ {
+ attr.iter().filter(|a| a.path().is_ident("cfg"))
+}
diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs
index 72ae0a1816a04..c6510b0c4ea1d 100644
--- a/rust/macros/vtable.rs
+++ b/rust/macros/vtable.rs
@@ -23,7 +23,6 @@
fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
let mut gen_items = Vec::new();
- let mut gen_consts = HashSet::new();
gen_items.push(parse_quote! {
/// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable)
@@ -38,22 +37,17 @@ fn handle_trait(mut item: ItemTrait) -> Result<ItemTrait> {
&format!("HAS_{}", name.to_string().to_uppercase()),
name.span(),
);
- // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
- // define functions.
- // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
- if gen_consts.contains(&gen_const_name) {
- continue;
- }
// We don't know on the implementation-site whether a method is required or provided
// so we have to generate a const for all methods.
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
let comment =
format!("Indicates if the `{name}` method is overridden by the implementor.");
gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
#[doc = #comment]
const #gen_const_name: bool = false;
});
- gen_consts.insert(gen_const_name);
}
}
@@ -87,10 +81,11 @@ fn handle_impl(mut item: ItemImpl) -> Result<ItemImpl> {
if defined_consts.contains(&gen_const_name) {
continue;
}
+ let cfg_attrs = crate::helpers::gather_cfg_attrs(&fn_item.attrs);
gen_items.push(parse_quote! {
+ #(#cfg_attrs)*
const #gen_const_name: bool = true;
});
- defined_consts.insert(gen_const_name);
}
}
base-commit: 761e1fbc67b122bfe3d58518a9ea9ee668962c92
--
2.51.2
^ permalink raw reply [flat|nested] 25+ messages in thread* Re: [PATCH v2] rust: macros: support `#[cfg]` properly in `#[vtable]` macro.
2026-01-13 17:05 ` [PATCH v2] " Gary Guo
@ 2026-01-17 20:09 ` Benno Lossin
0 siblings, 0 replies; 25+ messages in thread
From: Benno Lossin @ 2026-01-17 20:09 UTC (permalink / raw)
To: Gary Guo, Miguel Ojeda, Boqun Feng, Björn Roy Baron,
Andreas Hindborg, Alice Ryhl, Trevor Gross, Danilo Krummrich,
Tamir Duberstein
Cc: rust-for-linux, linux-kernel
On Tue Jan 13, 2026 at 6:05 PM CET, Gary Guo wrote:
> From: Gary Guo <gary@garyguo.net>
>
> Currently, we generate `HAS_` constants as long as the definition exists in
> the source, regardless if it is cfg-ed out or not.
>
> Currently, uses of `#[cfg]` present in both trait and impl, so it is not a
> problem; however if only the impl side uses `#[cfg]` then `HAS_` constants
> will incorrectly be true while it shouldnt't.
>
> With `syn` support, we can now implement `#[cfg]` handling properly by
> propagating the `#[cfg]` attributes to the constants.
>
> Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Cheers,
Benno
> ---
> rust/macros/helpers.rs | 6 ++++++
> rust/macros/vtable.rs | 13 ++++---------
> 2 files changed, 10 insertions(+), 9 deletions(-)
^ permalink raw reply [flat|nested] 25+ messages in thread