According to the rustdoc for the proc_macro crate[1], tokens captured
from a "macro variable" (e.g. from within macro_rules!) may be delimited
by invisible tokens and be contained within a proc_macro::Group.
Previously, this scenario was not handled by macros::paste, which caused
a proc-macro panic when the corresponding tests are enabled. Enable the
tests, and handle this case by making macros::paste::concat recursive.
[1]: https://doc.rust-lang.org/stable/proc_macro/enum.Delimiter.html
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index d8bd34c0ba89..8afed8facb21 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -269,12 +269,26 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
///
/// # Example
///
-/// ```ignore
-/// use kernel::macro::paste;
+/// ```
+/// # const binder_driver_return_protocol_BR_OK: u32 = 0;
+/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1;
+/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2;
+/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3;
+/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4;
+/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5;
+/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6;
+/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7;
+/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8;
+/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9;
+/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10;
+/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11;
+/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12;
+/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13;
+/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14;
///
/// macro_rules! pub_no_prefix {
/// ($prefix:ident, $($newname:ident),+) => {
-/// paste! {
+/// kernel::macros::paste! {
/// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+
/// }
/// };
@@ -313,13 +327,29 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
/// * `lower`: change the identifier to lower case.
/// * `upper`: change the identifier to upper case.
///
-/// ```ignore
-/// use kernel::macro::paste;
+/// ```rust
+/// # const binder_driver_return_protocol_BR_OK: u32 = 0;
+/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1;
+/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2;
+/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3;
+/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4;
+/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5;
+/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6;
+/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7;
+/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8;
+/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9;
+/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10;
+/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11;
+/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12;
+/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13;
+/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14;
///
/// macro_rules! pub_no_prefix {
/// ($prefix:ident, $($newname:ident),+) => {
/// kernel::macros::paste! {
-/// $(pub(crate) const fn [<$newname:lower:span>]: u32 = [<$prefix $newname:span>];)+
+/// $(pub(crate) const fn [<$newname:lower:span>]() -> u32 {
+/// [<$prefix $newname:span>]
+/// })+
/// }
/// };
/// }
@@ -350,7 +380,7 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
///
/// Literals can also be concatenated with other identifiers:
///
-/// ```ignore
+/// ```rust
/// macro_rules! create_numbered_fn {
/// ($name:literal, $val:literal) => {
/// kernel::macros::paste! {
diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs
index f40d42b35b58..6529a387673f 100644
--- a/rust/macros/paste.rs
+++ b/rust/macros/paste.rs
@@ -2,7 +2,7 @@
use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree};
-fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree {
+fn concat_helper(tokens: &[TokenTree]) -> Vec<(String, Span)> {
let mut tokens = tokens.iter();
let mut segments = Vec::new();
let mut span = None;
@@ -46,12 +46,21 @@ fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree {
};
segments.push((value, sp));
}
- _ => panic!("unexpected token in paste segments"),
+ Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::None => {
+ let tokens = group.stream().into_iter().collect::<Vec<TokenTree>>();
+ segments.append(&mut concat_helper(tokens.as_slice()));
+ }
+ token => panic!("unexpected token in paste segments: {:?}", token),
};
}
+ segments
+}
+
+fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree {
+ let segments = concat_helper(tokens);
let pasted: String = segments.into_iter().map(|x| x.0).collect();
- TokenTree::Ident(Ident::new(&pasted, span.unwrap_or(group_span)))
+ TokenTree::Ident(Ident::new(&pasted, group_span))
}
pub(crate) fn expand(tokens: &mut Vec<TokenTree>) {
--
2.44.2Ethan D. Twardy <ethan.twardy@gmail.com> writes:
> According to the rustdoc for the proc_macro crate[1], tokens captured
> from a "macro variable" (e.g. from within macro_rules!) may be delimited
> by invisible tokens and be contained within a proc_macro::Group.
> Previously, this scenario was not handled by macros::paste, which caused
> a proc-macro panic when the corresponding tests are enabled. Enable the
> tests, and handle this case by making macros::paste::concat recursive.
The actual change looks good to me.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
However, I have a bunch of formatting nits:
> [1]: https://doc.rust-lang.org/stable/proc_macro/enum.Delimiter.html
>
> Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Normally this would be formatted as:
Link: https://doc.rust-lang.org/stable/proc_macro/enum.Delimiter.html [1]
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
> diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
> index d8bd34c0ba89..8afed8facb21 100644
> --- a/rust/macros/lib.rs
> +++ b/rust/macros/lib.rs
> @@ -269,12 +269,26 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
> ///
> /// # Example
> ///
> -/// ```ignore
> -/// use kernel::macro::paste;
> +/// ```
> +/// # const binder_driver_return_protocol_BR_OK: u32 = 0;
> +/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1;
> +/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2;
> +/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3;
> +/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4;
> +/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5;
> +/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6;
> +/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7;
> +/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8;
> +/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9;
> +/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10;
> +/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11;
> +/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12;
> +/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13;
> +/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14;
> ///
> /// macro_rules! pub_no_prefix {
> /// ($prefix:ident, $($newname:ident),+) => {
There's a non-hidden empty line between the last constant and
`macro_rules! pub_no_prefix`. You should either hide the empty line or
get rid of it, because it will look weird when the example is rendered.
> -/// paste! {
> +/// kernel::macros::paste! {
Another option would be to keep the import so that the empty line
separates the import from the macro declaration.
> /// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+
> /// }
> /// };
> @@ -313,13 +327,29 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
> /// * `lower`: change the identifier to lower case.
> /// * `upper`: change the identifier to upper case.
> ///
> -/// ```ignore
> -/// use kernel::macro::paste;
> +/// ```rust
> +/// # const binder_driver_return_protocol_BR_OK: u32 = 0;
> +/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1;
> +/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2;
> +/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3;
> +/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4;
> +/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5;
> +/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6;
> +/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7;
> +/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8;
> +/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9;
> +/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10;
> +/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11;
> +/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12;
> +/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13;
> +/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14;
> ///
> /// macro_rules! pub_no_prefix {
> /// ($prefix:ident, $($newname:ident),+) => {
Same here.
> /// kernel::macros::paste! {
> -/// $(pub(crate) const fn [<$newname:lower:span>]: u32 = [<$prefix $newname:span>];)+
> +/// $(pub(crate) const fn [<$newname:lower:span>]() -> u32 {
> +/// [<$prefix $newname:span>]
> +/// })+
I would probably indent [<$prefix $newname:span>] one more time.
Alice
On Mon Jun 24, 2024 at 3:43 AM CDT, Alice Ryhl wrote: > The actual change looks good to me. > > Reviewed-by: Alice Ryhl <aliceryhl@google.com> > Thank you! > Normally this would be formatted as: > > Link: https://doc.rust-lang.org/stable/proc_macro/enum.Delimiter.html [1] > Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com> Ah, thank you for informing me on this :). > There's a non-hidden empty line between the last constant and > `macro_rules! pub_no_prefix`. You should either hide the empty line or > get rid of it, because it will look weird when the example is rendered. > > > Another option would be to keep the import so that the empty line > separates the import from the macro declaration. Done! (And the one other identical one, as well). > I would probably indent [<$prefix $newname:span>] one more time. > > Alice Done, as well. As with PATCH 2/4, these will ship with v2.
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