From 76c6845a8592931edd1e80dbccfd8cbd047e4f2b Mon Sep 17 00:00:00 2001
From: Elliot Roberts <Elliot0000101@gmail.com>
Date: Tue, 31 May 2022 16:59:28 -0700
Subject: [PATCH] Iterate over `maybe_unused_trait_imports` when checking dead
trait imports
---
compiler/rustc_middle/src/query/mod.rs | 4 +-
compiler/rustc_middle/src/ty/context.rs | 4 +-
compiler/rustc_middle/src/ty/mod.rs | 4 +-
compiler/rustc_middle/src/ty/query.rs | 2 +-
compiler/rustc_resolve/src/lib.rs | 4 +-
compiler/rustc_typeck/src/check_unused.rs | 56 ++++++++---------------
6 files changed, 29 insertions(+), 45 deletions(-)
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 38d8e0b581953..31b27abd0c8a2 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -1728,8 +1728,8 @@ rustc_queries! {
query upvars_mentioned(def_id: DefId) -> Option<&'tcx FxIndexMap<hir::HirId, hir::Upvar>> {
desc { |tcx| "collecting upvars mentioned in `{}`", tcx.def_path_str(def_id) }
}
- query maybe_unused_trait_import(def_id: LocalDefId) -> bool {
- desc { |tcx| "maybe_unused_trait_import for `{}`", tcx.def_path_str(def_id.to_def_id()) }
+ query maybe_unused_trait_imports(_: ()) -> &'tcx FxIndexSet<LocalDefId> {
+ desc { "fetching potentially unused trait imports" }
}
query maybe_unused_extern_crates(_: ()) -> &'tcx [(LocalDefId, Span)] {
desc { "looking up all possibly unused extern crates" }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index a0d92e2a5dd94..4cdeae2f4492c 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -2886,8 +2886,8 @@ pub fn provide(providers: &mut ty::query::Providers) {
assert_eq!(id, LOCAL_CRATE);
tcx.crate_name
};
- providers.maybe_unused_trait_import =
- |tcx, id| tcx.resolutions(()).maybe_unused_trait_imports.contains(&id);
+ providers.maybe_unused_trait_imports =
+ |tcx, ()| &tcx.resolutions(()).maybe_unused_trait_imports;
providers.maybe_unused_extern_crates =
|tcx, ()| &tcx.resolutions(()).maybe_unused_extern_crates[..];
providers.names_imported_by_glob_use = |tcx, id| {
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index a493aaac276b1..3a2d3408b9d93 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -28,7 +28,7 @@ pub use generics::*;
use rustc_ast as ast;
use rustc_attr as attr;
use rustc_data_structures::fingerprint::Fingerprint;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
use rustc_data_structures::intern::{Interned, WithStableHash};
use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
use rustc_data_structures::tagged_ptr::CopyTaggedPtr;
@@ -138,7 +138,7 @@ pub struct ResolverOutputs {
pub has_pub_restricted: bool,
pub access_levels: AccessLevels,
pub extern_crate_map: FxHashMap<LocalDefId, CrateNum>,
- pub maybe_unused_trait_imports: FxHashSet<LocalDefId>,
+ pub maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
pub maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
pub reexport_map: FxHashMap<LocalDefId, Vec<ModChild>>,
pub glob_map: FxHashMap<LocalDefId, FxHashSet<Symbol>>,
diff --git a/compiler/rustc_middle/src/ty/query.rs b/compiler/rustc_middle/src/ty/query.rs
index 65f41c5266d17..59794c4d3f0d8 100644
--- a/compiler/rustc_middle/src/ty/query.rs
+++ b/compiler/rustc_middle/src/ty/query.rs
@@ -37,7 +37,7 @@ use crate::ty::{self, AdtSizedConstraint, CrateInherentImpls, ParamEnvAnd, Ty, T
use rustc_ast as ast;
use rustc_ast::expand::allocator::AllocatorKind;
use rustc_attr as attr;
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
use rustc_data_structures::steal::Steal;
use rustc_data_structures::svh::Svh;
use rustc_data_structures::sync::Lrc;
diff --git a/compiler/rustc_resolve/src/lib.rs b/compiler/rustc_resolve/src/lib.rs
index 73c8a9d28bd5f..49c15d2c9ef1f 100644
--- a/compiler/rustc_resolve/src/lib.rs
+++ b/compiler/rustc_resolve/src/lib.rs
@@ -28,7 +28,7 @@ use rustc_ast::node_id::NodeMap;
use rustc_ast::{self as ast, NodeId, CRATE_NODE_ID};
use rustc_ast::{AngleBracketedArg, Crate, Expr, ExprKind, GenericArg, GenericArgs, LitKind, Path};
use rustc_ast_lowering::{LifetimeRes, ResolverAstLowering};
-use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap, FxIndexSet};
use rustc_data_structures::intern::Interned;
use rustc_data_structures::sync::Lrc;
use rustc_errors::{Applicability, DiagnosticBuilder, ErrorGuaranteed};
@@ -941,7 +941,7 @@ pub struct Resolver<'a> {
visibilities: FxHashMap<LocalDefId, ty::Visibility>,
has_pub_restricted: bool,
used_imports: FxHashSet<NodeId>,
- maybe_unused_trait_imports: FxHashSet<LocalDefId>,
+ maybe_unused_trait_imports: FxIndexSet<LocalDefId>,
maybe_unused_extern_crates: Vec<(LocalDefId, Span)>,
/// Privacy errors are delayed until the end in order to deduplicate them.
diff --git a/compiler/rustc_typeck/src/check_unused.rs b/compiler/rustc_typeck/src/check_unused.rs
index 00f0d1e6f02a9..f28184c74d355 100644
--- a/compiler/rustc_typeck/src/check_unused.rs
+++ b/compiler/rustc_typeck/src/check_unused.rs
@@ -16,48 +16,32 @@ pub fn check_crate(tcx: TyCtxt<'_>) {
used_trait_imports.extend(imports.iter());
}
- for id in tcx.hir().items() {
- if matches!(tcx.def_kind(id.def_id), DefKind::Use) {
- if tcx.visibility(id.def_id).is_public() {
- continue;
- }
- let item = tcx.hir().item(id);
- if item.span.is_dummy() {
- continue;
- }
- if let hir::ItemKind::Use(path, _) = item.kind {
- check_import(tcx, &mut used_trait_imports, item.item_id(), path.span);
- }
+ for &id in tcx.maybe_unused_trait_imports(()) {
+ debug_assert_eq!(tcx.def_kind(id), DefKind::Use);
+ if tcx.visibility(id).is_public() {
+ continue;
+ }
+ if used_trait_imports.contains(&id) {
+ continue;
}
+ let item = tcx.hir().expect_item(id);
+ if item.span.is_dummy() {
+ continue;
+ }
+ let hir::ItemKind::Use(path, _) = item.kind else { unreachable!() };
+ tcx.struct_span_lint_hir(lint::builtin::UNUSED_IMPORTS, item.hir_id(), path.span, |lint| {
+ let msg = if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(path.span) {
+ format!("unused import: `{}`", snippet)
+ } else {
+ "unused import".to_owned()
+ };
+ lint.build(&msg).emit();
+ });
}
unused_crates_lint(tcx);
}
-fn check_import<'tcx>(
- tcx: TyCtxt<'tcx>,
- used_trait_imports: &mut FxHashSet<LocalDefId>,
- item_id: hir::ItemId,
- span: Span,
-) {
- if !tcx.maybe_unused_trait_import(item_id.def_id) {
- return;
- }
-
- if used_trait_imports.contains(&item_id.def_id) {
- return;
- }
-
- tcx.struct_span_lint_hir(lint::builtin::UNUSED_IMPORTS, item_id.hir_id(), span, |lint| {
- let msg = if let Ok(snippet) = tcx.sess.source_map().span_to_snippet(span) {
- format!("unused import: `{}`", snippet)
- } else {
- "unused import".to_owned()
- };
- lint.build(&msg).emit();
- });
-}
-
fn unused_crates_lint(tcx: TyCtxt<'_>) {
let lint = lint::builtin::UNUSED_EXTERN_CRATES;