shuffle based on defpathhash

Author: jdonszelmann

Cargo.lock

@@ -3809,6 +3809,8 @@ name = "rustc_hir_analysis"
 version = "0.0.0"
 dependencies = [
  "itertools",
+ "rand 0.9.1",
+ "rand_xoshiro",
  "rustc_abi",
  "rustc_arena",
  "rustc_ast",

compiler/rustc_hir_analysis/Cargo.toml

@@ -10,6 +10,8 @@ doctest = false
 [dependencies]
 # tidy-alphabetical-start
 itertools = "0.12"
+rand = { version = "0.9.0", default-features = false }
+rand_xoshiro = { version = "0.7.0" }
 rustc_abi = { path = "../rustc_abi" }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }

compiler/rustc_hir_analysis/src/collect/distributed_slice.rs

@@ -1,3 +1,5 @@
+use rand::SeedableRng;
+use rand::seq::SliceRandom;
 use rustc_hir::def_id::{DefIdMap, LocalDefId};
 use rustc_hir::{DistributedSlice, ItemKind};
 use rustc_middle::ty::TyCtxt;
@@ -6,16 +8,29 @@ pub(super) fn distributed_slice_elements<'tcx>(
     tcx: TyCtxt<'tcx>,
     _: (),
 ) -> DefIdMap<Vec<LocalDefId>> {
-    let mut res = DefIdMap::<Vec<LocalDefId>>::default();
+    let mut slice_elements = DefIdMap::<Vec<LocalDefId>>::default();
 
     for i in tcx.hir_free_items() {
         let addition_def_id = i.owner_id.def_id;
         if let ItemKind::Const(.., DistributedSlice::Addition(declaration_def_id)) =
             tcx.hir_expect_item(addition_def_id).kind
         {
-            res.entry(declaration_def_id.to_def_id()).or_default().push(addition_def_id);
+            slice_elements.entry(declaration_def_id.to_def_id()).or_default().push(addition_def_id);
         }
     }
 
+    let mut res = DefIdMap::<Vec<LocalDefId>>::default();
+
+    for (key, mut registered_values) in
+        tcx.with_stable_hashing_context(|hcx| slice_elements.into_sorted(&hcx, true))
+    {
+        // shuffle seeded by the defpathhash of the registry
+        let item_seed = tcx.def_path_hash(key).0.to_smaller_hash();
+        let mut rng = rand_xoshiro::Xoshiro128StarStar::seed_from_u64(item_seed.as_u64());
+        registered_values.as_mut_slice().shuffle(&mut rng);
+
+        res.insert(key, registered_values);
+    }
+
     res
 }

tests/ui/crate_local_distributed_slice/create_slice.run.stdout

@@ -1 +1 @@
-["mrow", "mew"]
+["mew", "mrow"]