Use LocalDefIdSet instead of FxHashSet for reachable_set query.

Author: michaelwoerister

compiler/rustc_codegen_ssa/src/back/symbol_export.rs

@@ -58,7 +58,7 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, cnum: CrateNum) -> DefIdMap<
 
     let mut reachable_non_generics: DefIdMap<_> = tcx
         .reachable_set(())
-        .iter()
+        .items()
         .filter_map(|&def_id| {
             // We want to ignore some FFI functions that are not exposed from
             // this crate. Reachable FFI functions can be lumped into two
@@ -136,7 +136,7 @@ fn reachable_non_generics_provider(tcx: TyCtxt<'_>, cnum: CrateNum) -> DefIdMap<
             };
             (def_id.to_def_id(), info)
         })
-        .collect();
+        .into();
 
     if let Some(id) = tcx.proc_macro_decls_static(()) {
         reachable_non_generics.insert(

compiler/rustc_middle/src/query/mod.rs

@@ -1113,7 +1113,7 @@ rustc_queries! {
         desc { "checking for private elements in public interfaces" }
     }
 
-    query reachable_set(_: ()) -> &'tcx FxHashSet<LocalDefId> {
+    query reachable_set(_: ()) -> &'tcx LocalDefIdSet {
         arena_cache
         desc { "reachability" }
     }

compiler/rustc_middle/src/ty/query.rs

@@ -50,7 +50,7 @@ use rustc_data_structures::unord::UnordSet;
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, DocLinkResMap};
-use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId};
+use rustc_hir::def_id::{CrateNum, DefId, DefIdMap, DefIdSet, LocalDefId, LocalDefIdSet};
 use rustc_hir::hir_id::OwnerId;
 use rustc_hir::lang_items::{LangItem, LanguageItems};
 use rustc_hir::{Crate, ItemLocalId, TraitCandidate};

compiler/rustc_passes/src/reachable.rs

@@ -5,7 +5,7 @@
 // makes all other generics or inline functions that it references
 // reachable as well.
 
-use rustc_data_structures::fx::FxHashSet;
+use hir::def_id::LocalDefIdSet;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
@@ -63,7 +63,7 @@ struct ReachableContext<'tcx> {
     tcx: TyCtxt<'tcx>,
     maybe_typeck_results: Option<&'tcx ty::TypeckResults<'tcx>>,
     // The set of items which must be exported in the linkage sense.
-    reachable_symbols: FxHashSet<LocalDefId>,
+    reachable_symbols: LocalDefIdSet,
     // A worklist of item IDs. Each item ID in this worklist will be inlined
     // and will be scanned for further references.
     // FIXME(eddyb) benchmark if this would be faster as a `VecDeque`.
@@ -175,7 +175,7 @@ impl<'tcx> ReachableContext<'tcx> {
 
     // Step 2: Mark all symbols that the symbols on the worklist touch.
     fn propagate(&mut self) {
-        let mut scanned = FxHashSet::default();
+        let mut scanned = LocalDefIdSet::default();
         while let Some(search_item) = self.worklist.pop() {
             if !scanned.insert(search_item) {
                 continue;
@@ -361,7 +361,7 @@ fn has_custom_linkage(tcx: TyCtxt<'_>, def_id: LocalDefId) -> bool {
         || codegen_attrs.flags.contains(CodegenFnAttrFlags::USED_LINKER)
 }
 
-fn reachable_set(tcx: TyCtxt<'_>, (): ()) -> FxHashSet<LocalDefId> {
+fn reachable_set(tcx: TyCtxt<'_>, (): ()) -> LocalDefIdSet {
     let effective_visibilities = &tcx.effective_visibilities(());
 
     let any_library =

src/tools/miri/src/bin/miri.rs

@@ -109,11 +109,14 @@ impl rustc_driver::Callbacks for MiriBeRustCompilerCalls {
                 // an empty result if `tcx.sess.opts.output_types.should_codegen()` is false.
                 local_providers.exported_symbols = |tcx, cnum| {
                     assert_eq!(cnum, LOCAL_CRATE);
+                    let reachable_set = tcx.with_stable_hashing_context(|hcx| {
+                        tcx.reachable_set(()).to_sorted(&hcx, true)
+                    });
                     tcx.arena.alloc_from_iter(
                         // This is based on:
                         // https://github.com/rust-lang/rust/blob/2962e7c0089d5c136f4e9600b7abccfbbde4973d/compiler/rustc_codegen_ssa/src/back/symbol_export.rs#L62-L63
                         // https://github.com/rust-lang/rust/blob/2962e7c0089d5c136f4e9600b7abccfbbde4973d/compiler/rustc_codegen_ssa/src/back/symbol_export.rs#L174
-                        tcx.reachable_set(()).iter().filter_map(|&local_def_id| {
+                        reachable_set.into_iter().filter_map(|&local_def_id| {
                             // Do the same filtering that rustc does:
                             // https://github.com/rust-lang/rust/blob/2962e7c0089d5c136f4e9600b7abccfbbde4973d/compiler/rustc_codegen_ssa/src/back/symbol_export.rs#L84-L102
                             // Otherwise it may cause unexpected behaviours and ICEs