From 3e3e70d529d8c7d7c4d7bc4fefc9f109393b9245 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:43 +0200 Subject: Merging upstream version 1.69.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_hir_analysis/src/check_unused.rs | 135 +----------------------- 1 file changed, 2 insertions(+), 133 deletions(-) (limited to 'compiler/rustc_hir_analysis/src/check_unused.rs') diff --git a/compiler/rustc_hir_analysis/src/check_unused.rs b/compiler/rustc_hir_analysis/src/check_unused.rs index ebb78213a..f3f5851d8 100644 --- a/compiler/rustc_hir_analysis/src/check_unused.rs +++ b/compiler/rustc_hir_analysis/src/check_unused.rs @@ -1,12 +1,8 @@ -use crate::errors::{ExternCrateNotIdiomatic, UnusedExternCrate}; -use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::unord::UnordSet; -use rustc_hir as hir; use rustc_hir::def::DefKind; -use rustc_hir::def_id::{DefId, LocalDefId}; +use rustc_hir::def_id::LocalDefId; use rustc_middle::ty::TyCtxt; use rustc_session::lint; -use rustc_span::{Span, Symbol}; pub fn check_crate(tcx: TyCtxt<'_>) { let mut used_trait_imports: UnordSet = Default::default(); @@ -29,7 +25,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) { if item.span.is_dummy() { continue; } - let hir::ItemKind::Use(path, _) = item.kind else { unreachable!() }; + let (path, _) = item.expect_use(); let msg = if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(path.span) { format!("unused import: `{}`", snippet) } else { @@ -43,131 +39,4 @@ pub fn check_crate(tcx: TyCtxt<'_>) { |lint| lint, ); } - - unused_crates_lint(tcx); -} - -fn unused_crates_lint(tcx: TyCtxt<'_>) { - let lint = lint::builtin::UNUSED_EXTERN_CRATES; - - // Collect first the crates that are completely unused. These we - // can always suggest removing (no matter which edition we are - // in). - let unused_extern_crates: FxHashMap = tcx - .maybe_unused_extern_crates(()) - .iter() - .filter(|&&(def_id, _)| { - tcx.extern_mod_stmt_cnum(def_id).map_or(true, |cnum| { - !tcx.is_compiler_builtins(cnum) - && !tcx.is_panic_runtime(cnum) - && !tcx.has_global_allocator(cnum) - && !tcx.has_panic_handler(cnum) - }) - }) - .cloned() - .collect(); - - // Collect all the extern crates (in a reliable order). - let mut crates_to_lint = vec![]; - - for id in tcx.hir().items() { - if matches!(tcx.def_kind(id.owner_id), DefKind::ExternCrate) { - let item = tcx.hir().item(id); - if let hir::ItemKind::ExternCrate(orig_name) = item.kind { - crates_to_lint.push(ExternCrateToLint { - def_id: item.owner_id.to_def_id(), - span: item.span, - orig_name, - warn_if_unused: !item.ident.as_str().starts_with('_'), - }); - } - } - } - - let extern_prelude = &tcx.resolutions(()).extern_prelude; - - for extern_crate in &crates_to_lint { - let def_id = extern_crate.def_id.expect_local(); - let item = tcx.hir().expect_item(def_id); - - // If the crate is fully unused, we suggest removing it altogether. - // We do this in any edition. - if extern_crate.warn_if_unused { - if let Some(&span) = unused_extern_crates.get(&def_id) { - // Removal suggestion span needs to include attributes (Issue #54400) - let id = tcx.hir().local_def_id_to_hir_id(def_id); - let span_with_attrs = tcx - .hir() - .attrs(id) - .iter() - .map(|attr| attr.span) - .fold(span, |acc, attr_span| acc.to(attr_span)); - - tcx.emit_spanned_lint(lint, id, span, UnusedExternCrate { span: span_with_attrs }); - continue; - } - } - - // If we are not in Rust 2018 edition, then we don't make any further - // suggestions. - if !tcx.sess.rust_2018() { - continue; - } - - // If the extern crate isn't in the extern prelude, - // there is no way it can be written as a `use`. - let orig_name = extern_crate.orig_name.unwrap_or(item.ident.name); - if !extern_prelude.get(&orig_name).map_or(false, |from_item| !from_item) { - continue; - } - - // If the extern crate is renamed, then we cannot suggest replacing it with a use as this - // would not insert the new name into the prelude, where other imports in the crate may be - // expecting it. - if extern_crate.orig_name.is_some() { - continue; - } - - let id = tcx.hir().local_def_id_to_hir_id(def_id); - // If the extern crate has any attributes, they may have funky - // semantics we can't faithfully represent using `use` (most - // notably `#[macro_use]`). Ignore it. - if !tcx.hir().attrs(id).is_empty() { - continue; - } - - let base_replacement = match extern_crate.orig_name { - Some(orig_name) => format!("use {} as {};", orig_name, item.ident.name), - None => format!("use {};", item.ident.name), - }; - let vis = tcx.sess.source_map().span_to_snippet(item.vis_span).unwrap_or_default(); - let add_vis = |to| if vis.is_empty() { to } else { format!("{} {}", vis, to) }; - tcx.emit_spanned_lint( - lint, - id, - extern_crate.span, - ExternCrateNotIdiomatic { - span: extern_crate.span, - msg_code: add_vis("use".to_string()), - suggestion_code: add_vis(base_replacement), - }, - ); - } -} - -struct ExternCrateToLint { - /// `DefId` of the extern crate - def_id: DefId, - - /// span from the item - span: Span, - - /// if `Some`, then this is renamed (`extern crate orig_name as - /// crate_name`), and -- perhaps surprisingly -- this stores the - /// *original* name (`item.name` will contain the new name) - orig_name: Option, - - /// if `false`, the original name started with `_`, so we shouldn't lint - /// about it going unused (but we should still emit idiom lints). - warn_if_unused: bool, } -- cgit v1.2.3