From 7e06561fcd9636b6483c5fcd8fe935475f4944f8 Mon Sep 17 00:00:00 2001
From: "Ethan D. Twardy" <ethan.twardy@gmail.com>
Date: Thu, 4 Jul 2024 09:55:44 -0500
Subject: [PATCH] rust: macros: enable paste! use from macro_rules!
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.
Link: https://doc.rust-lang.org/stable/proc_macro/enum.Delimiter.html [1]
Signed-off-by: Ethan D. Twardy <ethan.twardy@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1076
Link: https://lore.kernel.org/r/20240704145607.17732-4-ethan.twardy@gmail.com
[ Rebased (one fix was already applied) and reworded. Remove unneeded
`rust` as language in examples. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
rust/macros/lib.rs | 42 ++++++++++++++++++++++++++++++++++--------
rust/macros/paste.rs | 15 ++++++++++++---
2 files changed, 46 insertions(+), 11 deletions(-)
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 114a5f7fc645c..83a041570e1ee 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -304,12 +304,25 @@ 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 $newname>];)+
/// }
/// };
@@ -348,9 +361,22 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
/// * `lower`: change the identifier to lower case.
/// * `upper`: change the identifier to upper case.
///
-/// ```ignore
-/// use kernel::macro::paste;
-///
+/// ```
+/// # const binder_driver_return_protocol_BR_OK: u32 = 0;
+/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1;
+/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2;
+/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3;
+/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4;
+/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5;
+/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6;
+/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7;
+/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8;
+/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9;
+/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10;
+/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11;
+/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12;
+/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13;
+/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14;
/// macro_rules! pub_no_prefix {
/// ($prefix:ident, $($newname:ident),+) => {
/// kernel::macros::paste! {
@@ -385,7 +411,7 @@ pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream {
///
/// Literals can also be concatenated with other identifiers:
///
-/// ```ignore
+/// ```
/// 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 f40d42b35b586..6529a387673fb 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>) {
--
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