Commit 514e4ed2 authored by Benno Lossin's avatar Benno Lossin
Browse files

rust: pin-init: add `syn` dependency and remove `proc-macro[2]` and `quote` workarounds 



`syn` makes parsing Rust from proc-macros a lot simpler. `pin-init` has
not used `syn` up until now, because the we did not support it. That
changed in commit 54e3eae8 ("Merge patch series "`syn` support""),
so we can finally utilize the added ergonomics of parsing proc-macro
input with `syn`.

Previously we only had the `proc-macro` library available, whereas the
user-space version also used `proc-macro2` and `quote`. Now both are
available, so remove the workarounds.

Due to these changes, clippy emits warnings about unnecessary
`.to_string()` as `proc-macro2` provides an additional `PartialEq` impl
on `Ident`, so the warnings are fixed.

[ Adjusted wording from upstream version and added build system changes
  for the kernel - Benno ]

Co-developed-by: default avatarGary Guo <gary@garyguo.net>
Signed-off-by: default avatarGary Guo <gary@garyguo.net>
Reviewed-by: default avatarTamir Duberstein <tamird@gmail.com>
Tested-by: default avatarAndreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: default avatarBenno Lossin <lossin@kernel.org>
parent 901f1d73

rust/Makefile

+10 −6
Original line number Diff line number Diff line
@@ -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 $@

rust/pin-init/internal/src/helpers.rs

+2 −5
Original line number Diff line number Diff line 
// 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;

rust/pin-init/internal/src/lib.rs

+0 −16
Original line number Diff line number Diff line
@@ -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;

rust/pin-init/internal/src/pin_data.rs

+6 −12
Original line number Diff line number Diff line 
// 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(),

rust/pin-init/internal/src/pinned_drop.rs

+4 −6
Original line number Diff line number Diff line 
// 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);