rust: macros: use quote! from vendored crate

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>

Author: nbdd0121

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;
 

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 {

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();

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);
                 }

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()))
                 }

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 @@ use proc_macro::TokenStream;
 ///     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()
 }

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);

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();

rust/macros/quote.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();
 
@@ -31,15 +32,15 @@ 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.
                     _ => continue,
                 };
                 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.