43 lines
1.3 KiB
Rust
43 lines
1.3 KiB
Rust
use rustc_data_structures::unord::UnordSet;
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use rustc_hir::def::DefKind;
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use rustc_hir::def_id::LocalDefId;
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use rustc_middle::ty::TyCtxt;
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use rustc_session::lint;
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pub fn check_crate(tcx: TyCtxt<'_>) {
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let mut used_trait_imports: UnordSet<LocalDefId> = Default::default();
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for item_def_id in tcx.hir().body_owners() {
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let imports = tcx.used_trait_imports(item_def_id);
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debug!("GatherVisitor: item_def_id={:?} with imports {:#?}", item_def_id, imports);
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used_trait_imports.extend_unord(imports.items().copied());
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}
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for &id in tcx.maybe_unused_trait_imports(()) {
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debug_assert_eq!(tcx.def_kind(id), DefKind::Use);
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if tcx.visibility(id).is_public() {
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continue;
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}
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if used_trait_imports.contains(&id) {
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continue;
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}
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let item = tcx.hir().expect_item(id);
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if item.span.is_dummy() {
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continue;
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}
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let (path, _) = item.expect_use();
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let msg = if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(path.span) {
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format!("unused import: `{}`", snippet)
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} else {
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"unused import".to_owned()
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};
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tcx.struct_span_lint_hir(
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lint::builtin::UNUSED_IMPORTS,
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item.hir_id(),
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path.span,
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msg,
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|lint| lint,
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);
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}
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}
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