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Merged
rust-bors merged 4 commits into from
May 7, 2026
Merged

Fewer global node_id_to_def_id lookups #156173

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0afe083
Avoid some global `node_id_to_def_id` lookups in import resolution
oli-obk May 5, 2026
191cda5
Avoid using `id` followed by `local_def_id` if we can just call `def_…
oli-obk May 5, 2026
400240a
Avoid hitting the global node_id_to_def_id table for unused macros
oli-obk May 5, 2026
a082567
Follow-up cleanups reusing the now-available `LocalDefId`s
oli-obk May 5, 2026
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13 changes: 10 additions & 3 deletions compiler/rustc_resolve/src/build_reduced_graph.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -720,13 +720,15 @@ impl<'a, 'ra, 'tcx> DefCollector<'a, 'ra, 'tcx> {
decls: Default::default(),
nested,
id,
def_id: feed.def_id(),
};

self.add_import(module_path, kind, use_tree.span(), item, root_span, item.id, vis);
}
ast::UseTreeKind::Glob(_) => {
if !ast::attr::contains_name(&item.attrs, sym::prelude_import) {
let kind = ImportKind::Glob { max_vis: CmCell::new(None), id };
let kind =
ImportKind::Glob { max_vis: CmCell::new(None), id, def_id: feed.def_id() };
self.add_import(prefix, kind, use_tree.span(), item, root_span, item.id, vis);
} else {
// Resolve the prelude import early.
Expand Down Expand Up @@ -1018,7 +1020,12 @@ impl<'a, 'ra, 'tcx> DefCollector<'a, 'ra, 'tcx> {
})
.unwrap_or((true, None, self.r.dummy_decl));
let import = self.r.arenas.alloc_import(ImportData {
kind: ImportKind::ExternCrate { source: orig_name, target: orig_ident, id: item.id },
kind: ImportKind::ExternCrate {
source: orig_name,
target: orig_ident,
id: item.id,
def_id: local_def_id,
},
root_id: item.id,
parent_scope,
imported_module: CmCell::new(module),
Expand Down Expand Up @@ -1270,7 +1277,7 @@ impl<'a, 'ra, 'tcx> DefCollector<'a, 'ra, 'tcx> {
if !ident.as_str().starts_with('_') {
self.r.unused_macros.insert(def_id, (node_id, ident));
let nrules = self.r.local_macro_map[&def_id].nrules;
self.r.unused_macro_rules.insert(node_id, DenseBitSet::new_filled(nrules));
self.r.unused_macro_rules.insert(node_id, (def_id, DenseBitSet::new_filled(nrules)));
}
}

Expand Down
3 changes: 1 addition & 2 deletions compiler/rustc_resolve/src/check_unused.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -431,8 +431,7 @@ impl Resolver<'_, '_> {
}
}
}
ImportKind::ExternCrate { id, .. } => {
let def_id = self.local_def_id(id);
ImportKind::ExternCrate { id, def_id, .. } => {
if self.extern_crate_map.get(&def_id).is_none_or(|&cnum| {
!tcx.is_compiler_builtins(cnum)
&& !tcx.is_panic_runtime(cnum)
Expand Down
9 changes: 3 additions & 6 deletions compiler/rustc_resolve/src/effective_visibilities.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -45,10 +45,7 @@ impl Resolver<'_, '_> {
fn private_vis_import(&self, decl: Decl<'_>) -> Visibility {
let DeclKind::Import { import, .. } = decl.kind else { unreachable!() };
Visibility::Restricted(
import
.id()
.map(|id| self.nearest_normal_mod(self.local_def_id(id)))
.unwrap_or(CRATE_DEF_ID),
import.def_id().map(|id| self.nearest_normal_mod(id)).unwrap_or(CRATE_DEF_ID),
)
}

Expand Down Expand Up @@ -96,8 +93,8 @@ impl<'a, 'ra, 'tcx> EffectiveVisibilitiesVisitor<'a, 'ra, 'tcx> {
// is the maximum value among visibilities of declarations corresponding to that def id.
for (decl, eff_vis) in visitor.import_effective_visibilities.iter() {
let DeclKind::Import { import, .. } = decl.kind else { unreachable!() };
if let Some(node_id) = import.id() {
r.effective_visibilities.update_eff_vis(r.local_def_id(node_id), eff_vis, r.tcx)
if let Some(def_id) = import.def_id() {
r.effective_visibilities.update_eff_vis(def_id, eff_vis, r.tcx)
}
if decl.ambiguity.get().is_some() && eff_vis.is_public_at_level(Level::Reexported) {
exported_ambiguities.insert(*decl);
Expand Down
69 changes: 43 additions & 26 deletions compiler/rustc_resolve/src/imports.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ use rustc_hir::Attribute;
use rustc_hir::attrs::AttributeKind;
use rustc_hir::attrs::diagnostic::{CustomDiagnostic, Directive, FormatArgs};
use rustc_hir::def::{self, DefKind, PartialRes};
use rustc_hir::def_id::{DefId, LocalDefIdMap};
use rustc_hir::def_id::{DefId, LocalDefId, LocalDefIdMap};
use rustc_middle::metadata::{AmbigModChild, ModChild, Reexport};
use rustc_middle::span_bug;
use rustc_middle::ty::{TyCtxt, Visibility};
Expand Down Expand Up @@ -90,17 +90,20 @@ pub(crate) enum ImportKind<'ra> {
/// If this is the import for `foo::bar::a`, we would have the ID of the `UseTree`
/// for `a` in this field.
id: NodeId,
def_id: LocalDefId,
},
Glob {
// The visibility of the greatest re-export.
// n.b. `max_vis` is only used in `finalize_import` to check for re-export errors.
max_vis: CmCell<Option<Visibility>>,
id: NodeId,
def_id: LocalDefId,
},
ExternCrate {
source: Option<Symbol>,
target: Ident,
id: NodeId,
def_id: LocalDefId,
},
MacroUse {
/// A field has been added indicating whether it should be reported as a lint,
Expand All @@ -116,7 +119,7 @@ impl<'ra> std::fmt::Debug for ImportKind<'ra> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
use ImportKind::*;
match self {
Single { source, target, decls, nested, id, .. } => f
Single { source, target, decls, nested, id, def_id } => f
.debug_struct("Single")
.field("source", source)
.field("target", target)
Expand All @@ -127,15 +130,20 @@ impl<'ra> std::fmt::Debug for ImportKind<'ra> {
)
.field("nested", nested)
.field("id", id)
.field("def_id", def_id)
.finish(),
Glob { max_vis, id } => {
f.debug_struct("Glob").field("max_vis", max_vis).field("id", id).finish()
}
ExternCrate { source, target, id } => f
Glob { max_vis, id, def_id } => f
.debug_struct("Glob")
.field("max_vis", max_vis)
.field("id", id)
.field("def_id", def_id)
.finish(),
ExternCrate { source, target, id, def_id } => f
.debug_struct("ExternCrate")
.field("source", source)
.field("target", target)
Comment thread
oli-obk marked this conversation as resolved.
.field("id", id)
.field("def_id", def_id)
.finish(),
MacroUse { warn_private } => {
f.debug_struct("MacroUse").field("warn_private", warn_private).finish()
Expand Down Expand Up @@ -260,12 +268,20 @@ impl<'ra> ImportData<'ra> {
}
}

pub(crate) fn simplify(&self, r: &Resolver<'_, '_>) -> Reexport {
let to_def_id = |id| r.local_def_id(id).to_def_id();
pub(crate) fn def_id(&self) -> Option<LocalDefId> {
match self.kind {
ImportKind::Single { def_id, .. }
| ImportKind::Glob { def_id, .. }
| ImportKind::ExternCrate { def_id, .. } => Some(def_id),
ImportKind::MacroUse { .. } | ImportKind::MacroExport => None,
}
}

pub(crate) fn simplify(&self) -> Reexport {
match self.kind {
ImportKind::Single { id, .. } => Reexport::Single(to_def_id(id)),
ImportKind::Glob { id, .. } => Reexport::Glob(to_def_id(id)),
ImportKind::ExternCrate { id, .. } => Reexport::ExternCrate(to_def_id(id)),
ImportKind::Single { def_id, .. } => Reexport::Single(def_id.to_def_id()),
ImportKind::Glob { def_id, .. } => Reexport::Glob(def_id.to_def_id()),
ImportKind::ExternCrate { def_id, .. } => Reexport::ExternCrate(def_id.to_def_id()),
ImportKind::MacroUse { .. } => Reexport::MacroUse,
ImportKind::MacroExport => Reexport::MacroExport,
}
Expand Down Expand Up @@ -340,13 +356,16 @@ struct UnresolvedImportError {

// Reexports of the form `pub use foo as bar;` where `foo` is `extern crate foo;`
// are permitted for backward-compatibility under a deprecation lint.
fn pub_use_of_private_extern_crate_hack(import: ImportSummary, decl: Decl<'_>) -> Option<NodeId> {
fn pub_use_of_private_extern_crate_hack(
import: ImportSummary,
decl: Decl<'_>,
) -> Option<LocalDefId> {
match (import.is_single, decl.kind) {
(true, DeclKind::Import { import: decl_import, .. })
if let ImportKind::ExternCrate { id, .. } = decl_import.kind
if let ImportKind::ExternCrate { def_id, .. } = decl_import.kind
&& import.vis.is_public() =>
{
Some(id)
Some(def_id)
}
_ => None,
}
Expand Down Expand Up @@ -845,8 +864,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
if binding.res() != Res::Err
&& glob_decl.res() != Res::Err
&& let DeclKind::Import { import: glob_import, .. } = glob_decl.kind
&& let Some(glob_import_id) = glob_import.id()
&& let glob_import_def_id = self.local_def_id(glob_import_id)
&& let Some(glob_import_def_id) = glob_import.def_id()
&& self.effective_visibilities.is_exported(glob_import_def_id)
&& glob_decl.vis().is_public()
&& !binding.vis().is_public()
Expand Down Expand Up @@ -875,7 +893,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {

if let DeclKind::Import { import, .. } = binding.kind
&& let Some(binding_id) = import.id()
&& let import_def_id = self.local_def_id(binding_id)
&& let import_def_id = import.def_id().unwrap()
&& self.effective_visibilities.is_exported(import_def_id)
&& let Res::Def(reexported_kind, reexported_def_id) = binding.res()
&& !matches!(reexported_kind, DefKind::Ctor(..))
Expand Down Expand Up @@ -1267,7 +1285,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {

let (ident, target, bindings, import_id) = match import.kind {
ImportKind::Single { source, target, ref decls, id, .. } => (source, target, decls, id),
ImportKind::Glob { ref max_vis, id } => {
ImportKind::Glob { ref max_vis, id, def_id } => {
if import.module_path.len() <= 1 {
// HACK(eddyb) `lint_if_path_starts_with_module` needs at least
// 2 segments, so the `resolve_path` above won't trigger it.
Expand All @@ -1294,7 +1312,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
if let Some(max_vis) = max_vis.get()
&& import.vis.greater_than(max_vis, self.tcx)
{
let def_id = self.local_def_id(id);
self.lint_buffer.buffer_lint(
UNUSED_IMPORTS,
id,
Expand Down Expand Up @@ -1614,7 +1631,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
if let Some(extern_crate_id) = pub_use_of_private_extern_crate_hack(import.summary(), decl)
{
let ImportKind::Single { id, .. } = import.kind else { unreachable!() };
let sugg = self.tcx.source_span(self.local_def_id(extern_crate_id)).shrink_to_lo();
let sugg = self.tcx.source_span(extern_crate_id).shrink_to_lo();
let diagnostic = crate::errors::PrivateExternCrateReexport { ident, sugg };
return Some(BufferedEarlyLint {
lint_id: LintId::of(PUB_USE_OF_PRIVATE_EXTERN_CRATE),
Expand Down Expand Up @@ -1656,7 +1673,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {

pub(crate) fn check_for_redundant_imports(&mut self, import: Import<'ra>) -> bool {
// This function is only called for single imports.
let ImportKind::Single { source, target, ref decls, id, .. } = import.kind else {
let ImportKind::Single { source, target, ref decls, id, def_id, .. } = import.kind else {
unreachable!()
};

Expand All @@ -1675,7 +1692,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
// Skip if the import is public or was used through non scope-based resolution,
// e.g. through a module-relative path.
if self.import_use_map.get(&import) == Some(&Used::Other)
|| self.effective_visibilities.is_exported(self.local_def_id(id))
|| self.effective_visibilities.is_exported(def_id)
{
return false;
}
Expand Down Expand Up @@ -1829,23 +1846,23 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
let mut children = Vec::new();
let mut ambig_children = Vec::new();

module.to_module().for_each_child(self, |this, ident, orig_ident_span, _, binding| {
module.to_module().for_each_child(self, |_this, ident, orig_ident_span, _, binding| {
let res = binding.res().expect_non_local();
if res != def::Res::Err {
let ident = ident.orig(orig_ident_span);
let child =
|reexport_chain| ModChild { ident, res, vis: binding.vis(), reexport_chain };
if let Some((ambig_binding1, ambig_binding2)) = binding.descent_to_ambiguity() {
let main = child(ambig_binding1.reexport_chain(this));
let main = child(ambig_binding1.reexport_chain());
let second = ModChild {
ident,
res: ambig_binding2.res().expect_non_local(),
vis: ambig_binding2.vis(),
reexport_chain: ambig_binding2.reexport_chain(this),
reexport_chain: ambig_binding2.reexport_chain(),
};
ambig_children.push(AmbigModChild { main, second })
} else {
children.push(child(binding.reexport_chain(this)));
children.push(child(binding.reexport_chain()));
}
}
});
Expand Down
14 changes: 6 additions & 8 deletions compiler/rustc_resolve/src/lib.rs
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Expand Up @@ -1171,11 +1171,11 @@ impl<'ra> DeclData<'ra> {
self.res().macro_kinds()
}

fn reexport_chain(self: Decl<'ra>, r: &Resolver<'_, '_>) -> SmallVec<[Reexport; 2]> {
fn reexport_chain(self: Decl<'ra>) -> SmallVec<[Reexport; 2]> {
let mut reexport_chain = SmallVec::new();
let mut next_binding = self;
while let DeclKind::Import { source_decl, import, .. } = next_binding.kind {
reexport_chain.push(import.simplify(r));
reexport_chain.push(import.simplify());
next_binding = source_decl;
}
reexport_chain
Expand Down Expand Up @@ -1405,8 +1405,8 @@ pub struct Resolver<'ra, 'tcx> {
local_macro_def_scopes: FxHashMap<LocalDefId, LocalModule<'ra>> = default::fx_hash_map(),
ast_transform_scopes: FxHashMap<LocalExpnId, LocalModule<'ra>> = default::fx_hash_map(),
unused_macros: FxIndexMap<LocalDefId, (NodeId, Ident)>,
/// A map from the macro to all its potentially unused arms.
unused_macro_rules: FxIndexMap<NodeId, DenseBitSet<usize>>,
/// A map from the macro to all its potentially unused arms and the `LocalDefId` of the macro itself.
unused_macro_rules: FxIndexMap<NodeId, (LocalDefId, DenseBitSet<usize>)>,
Comment thread
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proc_macro_stubs: FxHashSet<LocalDefId> = default::fx_hash_set(),
/// Traces collected during macro resolution and validated when it's complete.
single_segment_macro_resolutions:
Expand Down Expand Up @@ -2155,8 +2155,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
) -> &'tcx [LocalDefId] {
let mut import_ids: SmallVec<[LocalDefId; 1]> = smallvec![];
while let DeclKind::Import { import, source_decl, .. } = kind {
if let Some(node_id) = import.id() {
let def_id = self.local_def_id(node_id);
if let Some(def_id) = import.def_id() {
self.maybe_unused_trait_imports.insert(def_id);
import_ids.push(def_id);
}
Expand Down Expand Up @@ -2292,8 +2291,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {

#[inline]
fn add_to_glob_map(&mut self, import: Import<'_>, name: Symbol) {
if let ImportKind::Glob { id, .. } = import.kind {
let def_id = self.local_def_id(id);
if let ImportKind::Glob { def_id, .. } = import.kind {
self.glob_map.entry(def_id).or_default().insert(name);
}
}
Expand Down
5 changes: 2 additions & 3 deletions compiler/rustc_resolve/src/macros.rs
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Expand Up @@ -339,7 +339,7 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
}

fn record_macro_rule_usage(&mut self, id: NodeId, rule_i: usize) {
if let Some(rules) = self.unused_macro_rules.get_mut(&id) {
if let Some((_, rules)) = self.unused_macro_rules.get_mut(&id) {
rules.remove(rule_i);
}
}
Expand All @@ -356,11 +356,10 @@ impl<'ra, 'tcx> ResolverExpand for Resolver<'ra, 'tcx> {
self.unused_macro_rules.swap_remove(&node_id);
}

for (&node_id, unused_arms) in self.unused_macro_rules.iter() {
for (&node_id, (def_id, unused_arms)) in self.unused_macro_rules.iter() {
if unused_arms.is_empty() {
continue;
}
let def_id = self.local_def_id(node_id);
let m = &self.local_macro_map[&def_id];
let SyntaxExtensionKind::MacroRules(ref m) = m.ext.kind else {
continue;
Expand Down
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