diff --git a/rust/pin-init/internal/src/pin_data.rs b/rust/pin-init/internal/src/pin_data.rs index 4ffa35bbbccd..ac83f0f73e61 100644 --- a/rust/pin-init/internal/src/pin_data.rs +++ b/rust/pin-init/internal/src/pin_data.rs @@ -137,12 +137,7 @@ pub(crate) fn pin_data( .iter_mut() .enumerate() .map(|(index, field)| { - let len = field.attrs.len(); - field.attrs.retain(|a| !a.path().is_ident("pin")); - let pinned_count = len - field.attrs.len(); - if pinned_count > 1 { - dcx.error(&field, "#[pin] attribute specified more than once"); - } + let pinned = field.attrs.extract_single_attr(dcx, "pin").is_some(); assert!( !field.attrs.iter().any(|a| a.path().is_ident("cfg")), @@ -159,7 +154,7 @@ pub(crate) fn pin_data( FieldInfo { field: &*field, member, - pinned: pinned_count != 0, + pinned, } }) .collect(); diff --git a/rust/pin-init/internal/src/util.rs b/rust/pin-init/internal/src/util.rs index 2a57a25b70ae..3ce498cea754 100644 --- a/rust/pin-init/internal/src/util.rs +++ b/rust/pin-init/internal/src/util.rs @@ -4,8 +4,15 @@ use quote::{format_ident, ToTokens}; use syn::{Attribute, GenericParam, Generics, Index, Member, Token}; +use crate::DiagCtxt; + pub(crate) trait AttrListExt { fn extract_cfg_attrs(&mut self) -> Vec; + + /// Extract attribute with identifier `path`. + /// + /// Report error if the attribute appears multiple times. + fn extract_single_attr(&mut self, dcx: &DiagCtxt, path: &str) -> Option; } impl AttrListExt for Vec { @@ -25,6 +32,24 @@ fn extract_cfg_attrs(&mut self) -> Vec { cfg } + + fn extract_single_attr(&mut self, dcx: &DiagCtxt, path: &str) -> Option { + // FIXME: Replace with `extract_if` when MSRV >= 1.85. + let attr_pos = self.iter().position(|attr| attr.path().is_ident(path))?; + let attr = self.remove(attr_pos); + self.retain(|attr| { + if !attr.path().is_ident(path) { + return true; + } + + dcx.error( + attr, + format!("`#[{path}]` attribute specified more than once"), + ); + false + }); + Some(attr) + } } pub(crate) trait MemberExt {