crates is already deterministic

compiler/rustc_metadata/src/dependency_format.rs

@@ -277,7 +277,7 @@ fn attempt_static(tcx: TyCtxt<'_>) -> Option<DependencyList> {
     let all_crates_available_as_rlib = tcx
         .crates(())
         .iter()
-        .cloned()
+        .copied()
         .filter_map(|cnum| {
             if tcx.dep_kind(cnum).macros_only() {
                 return None;
@@ -291,10 +291,11 @@ fn attempt_static(tcx: TyCtxt<'_>) -> Option<DependencyList> {
 
     // All crates are available in an rlib format, so we're just going to link
     // everything in explicitly so long as it's actually required.
-    let last_crate = tcx.crates(()).len();
+    let mut ret = tcx
-    let mut ret = (1..last_crate + 1)
+        .crates(())
-        .map(|cnum| {
+        .iter()
-            if tcx.dep_kind(CrateNum::new(cnum)) == CrateDepKind::Explicit {
+        .map(|&cnum| {
+            if tcx.dep_kind(cnum) == CrateDepKind::Explicit {
                 Linkage::Static
             } else {
                 Linkage::NotLinked

compiler/rustc_metadata/src/rmeta/decoder/cstore_impl.rs

@@ -304,17 +304,7 @@ pub fn provide(providers: &mut Providers) {
             // traversal, but not globally minimal across all crates.
             let bfs_queue = &mut VecDeque::new();
 
-            // Preferring shortest paths alone does not guarantee a
+            for &cnum in tcx.crates(()) {
-            // deterministic result; so sort by crate num to avoid
-            // hashtable iteration non-determinism. This only makes
-            // things as deterministic as crate-nums assignment is,
-            // which is to say, its not deterministic in general. But
-            // we believe that libstd is consistently assigned crate
-            // num 1, so it should be enough to resolve #46112.
-            let mut crates: Vec<CrateNum> = (*tcx.crates(())).to_owned();
-            crates.sort();
-
-            for &cnum in crates.iter() {
                 // Ignore crates without a corresponding local `extern crate` item.
                 if tcx.missing_extern_crate_item(cnum) {
                     continue;
@@ -323,9 +313,6 @@ pub fn provide(providers: &mut Providers) {
                 bfs_queue.push_back(DefId { krate: cnum, index: CRATE_DEF_INDEX });
             }
 
-            // (restrict scope of mutable-borrow of `visible_parent_map`)
-            {
-                let visible_parent_map = &mut visible_parent_map;
             let mut add_child = |bfs_queue: &mut VecDeque<_>, child: &Export, parent: DefId| {
                 if child.vis != ty::Visibility::Public {
                     return;
@@ -353,7 +340,6 @@ pub fn provide(providers: &mut Providers) {
                     add_child(bfs_queue, child, def);
                 }
             }
-            }
 
             visible_parent_map
         },

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1708,9 +1708,10 @@ impl EncodeContext<'a, 'tcx> {
 
     fn encode_crate_deps(&mut self) -> Lazy<[CrateDep]> {
         empty_proc_macro!(self);
-        let crates = self.tcx.crates(());
 
-        let mut deps = crates
+        let deps = self
+            .tcx
+            .crates(())
             .iter()
             .map(|&cnum| {
                 let dep = CrateDep {
@@ -1724,8 +1725,6 @@ impl EncodeContext<'a, 'tcx> {
             })
             .collect::<Vec<_>>();
 
-        deps.sort_by_key(|&(cnum, _)| cnum);
-
         {
             // Sanity-check the crate numbers
             let mut expected_cnum = 1;