Don't duplicate collection results

rust-lang · Nov 4, 2024 · 1add34f · 1add34f
1 parent 239084c
commit 1add34f
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Showing 5 changed files with 84 additions and 46 deletions.
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
@@ -255,7 +255,44 @@ pub(crate) struct UsageMap<'tcx> {
     user_map: UnordMap<MonoItem<'tcx>, Vec<MonoItem<'tcx>>>,
 }
 
-type MonoItems<'tcx> = Vec<Spanned<MonoItem<'tcx>>>;
+struct MonoItems<'tcx> {
+    tcx: TyCtxt<'tcx>,
+    // We want a set of MonoItem + Span where trying to re-insert a MonoItem with a different Span
+    // is ignored. Map does that, but it looks wrong.
+    items: UnordMap<MonoItem<'tcx>, Span>,
+}
+
+impl<'tcx> MonoItems<'tcx> {
+    fn new(tcx: TyCtxt<'tcx>) -> Self {
+        Self { tcx, items: UnordMap::default() }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.items.is_empty()
+    }
+
+    fn push(&mut self, item: Spanned<MonoItem<'tcx>>) {
+        // Insert only if the entry does not exist. A normal insert would stomp the first span that
+        // got inserted.
+        self.items.entry(item.node).or_insert(item.span);
+    }
+
+    fn extend(&mut self, iter: impl IntoIterator<Item = Spanned<MonoItem<'tcx>>>) {
+        for item in iter {
+            self.push(item.clone());
+        }
+    }
+
+    fn into_iter(self) -> impl Iterator<Item = Spanned<MonoItem<'tcx>>> {
+        self.tcx.with_stable_hashing_context(|hcx| {
+            self.items.into_sorted(&hcx, true).into_iter().map(|(item, span)| respan(span, item))
+        })
+    }
+
+    fn items(&self) -> Vec<MonoItem<'tcx>> {
+        self.tcx.with_stable_hashing_context(|hcx| self.items.keys().cloned().into_sorted(&hcx))
+    }
+}
 
 /// The state that is shared across the concurrent threads that are doing collection.
 struct SharedState<'tcx> {
@@ -273,14 +310,11 @@ impl<'tcx> UsageMap<'tcx> {
         UsageMap { used_map: Default::default(), user_map: Default::default() }
     }
 
-    fn record_used<'a>(
-        &mut self,
-        user_item: MonoItem<'tcx>,
-        used_items: &'a [Spanned<MonoItem<'tcx>>],
-    ) where
+    fn record_used<'a>(&mut self, user_item: MonoItem<'tcx>, used_items: &'a MonoItems<'tcx>)
+    where
         'tcx: 'a,
     {
-        let used_items: Vec<_> = used_items.iter().map(|item| item.node).collect();
+        let used_items = used_items.items();
         for &used_item in used_items.iter() {
             self.user_map.entry(used_item).or_default().push(user_item);
         }
@@ -343,8 +377,8 @@ fn collect_items_rec<'tcx>(
         // harm in that, the mention visit will trigger all the queries and the results are cached.
     }
 
-    let mut used_items = MonoItems::new();
-    let mut mentioned_items = MonoItems::new();
+    let mut used_items = MonoItems::new(tcx);
+    let mut mentioned_items = MonoItems::new(tcx);
     let recursion_depth_reset;
 
     // Post-monomorphization errors MVP
@@ -430,8 +464,8 @@ fn collect_items_rec<'tcx>(
 
             rustc_data_structures::stack::ensure_sufficient_stack(|| {
                 let (used, mentioned) = tcx.items_of_instance((instance, mode));
-                used_items.extend(used);
-                mentioned_items.extend(mentioned);
+                used_items.extend(used.into_iter().copied());
+                mentioned_items.extend(mentioned.into_iter().copied());
             });
         }
         MonoItem::GlobalAsm(item_id) => {
@@ -503,7 +537,7 @@ fn collect_items_rec<'tcx>(
     if mode == CollectionMode::MentionedItems {
         assert!(used_items.is_empty(), "'mentioned' collection should never encounter used items");
     } else {
-        for used_item in used_items {
+        for used_item in used_items.into_iter() {
             collect_items_rec(
                 tcx,
                 used_item,
@@ -517,7 +551,7 @@ fn collect_items_rec<'tcx>(
 
     // Walk over mentioned items *after* used items, so that if an item is both mentioned and used then
     // the loop above has fully collected it, so this loop will skip it.
-    for mentioned_item in mentioned_items {
+    for mentioned_item in mentioned_items.into_iter() {
         collect_items_rec(
             tcx,
             mentioned_item,
@@ -1194,8 +1228,8 @@ fn collect_items_of_instance<'tcx>(
     // mentioned item. So instead we collect all pre-monomorphized `MentionedItem` that were already
     // added to `used_items` in a hash set, which can efficiently query in the
     // `body.mentioned_items` loop below without even having to monomorphize the item.
-    let mut used_items = Default::default();
-    let mut mentioned_items = Default::default();
+    let mut used_items = MonoItems::new(tcx);
+    let mut mentioned_items = MonoItems::new(tcx);
     let mut used_mentioned_items = Default::default();
     let mut collector = MirUsedCollector {
         tcx,
@@ -1238,7 +1272,11 @@ fn items_of_instance<'tcx>(
     (instance, mode): (Instance<'tcx>, CollectionMode),
 ) -> (&'tcx [Spanned<MonoItem<'tcx>>], &'tcx [Spanned<MonoItem<'tcx>>]) {
     let (used_items, mentioned_items) = collect_items_of_instance(tcx, instance, mode);
-    (tcx.arena.alloc_slice(&used_items), tcx.arena.alloc_slice(&mentioned_items))
+
+    let used_items = tcx.arena.alloc_from_iter(used_items.into_iter());
+    let mentioned_items = tcx.arena.alloc_from_iter(mentioned_items.into_iter());
+
+    (used_items, mentioned_items)
 }
 
 /// `item` must be already monomorphized.
@@ -1319,7 +1357,7 @@ fn collect_const_value<'tcx>(
 #[instrument(skip(tcx, mode), level = "debug")]
 fn collect_roots(tcx: TyCtxt<'_>, mode: MonoItemCollectionStrategy) -> Vec<MonoItem<'_>> {
     debug!("collecting roots");
-    let mut roots = Vec::new();
+    let mut roots = MonoItems::new(tcx);
 
     {
         let entry_fn = tcx.entry_fn(());

diff --git a/tests/ui/codegen/overflow-during-mono.rs b/tests/ui/codegen/overflow-during-mono.rs
@@ -1,4 +1,4 @@
-//~ ERROR overflow evaluating the requirement `{closure@$DIR/overflow-during-mono.rs:13:41: 13:44}: Sized`
+//~ ERROR overflow evaluating the requirement
 //@ build-fail
 
 #![recursion_limit = "32"]

diff --git a/tests/ui/codegen/overflow-during-mono.stderr b/tests/ui/codegen/overflow-during-mono.stderr
@@ -1,10 +1,10 @@
-error[E0275]: overflow evaluating the requirement `{closure@$DIR/overflow-during-mono.rs:13:41: 13:44}: Sized`
+error[E0275]: overflow evaluating the requirement `{closure@$DIR/overflow-during-mono.rs:14:36: 14:39}: Sized`
    |
    = help: consider increasing the recursion limit by adding a `#![recursion_limit = "64"]` attribute to your crate (`overflow_during_mono`)
-   = note: required for `Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `Iterator`
+   = note: required for `Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>` to implement `Iterator`
    = note: 31 redundant requirements hidden
-   = note: required for `Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `Iterator`
-   = note: required for `Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `IntoIterator`
+   = note: required for `Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `Iterator`
+   = note: required for `Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<Filter<std::array::IntoIter<i32, 11>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>, {closure@$DIR/overflow-during-mono.rs:14:36: 14:39}>, {closure@$DIR/overflow-during-mono.rs:13:41: 13:44}>` to implement `IntoIterator`
 
 error: aborting due to 1 previous error
 

diff --git a/tests/ui/inline-const/const-expr-generic-err.stderr b/tests/ui/inline-const/const-expr-generic-err.stderr
@@ -1,23 +1,3 @@
-error[E0080]: evaluation of `foo::<i32>::{constant#0}` failed
-  --> $DIR/const-expr-generic-err.rs:4:13
-   |
-LL |     const { assert!(std::mem::size_of::<T>() == 0); }
-   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'assertion failed: std::mem::size_of::<T>() == 0', $DIR/const-expr-generic-err.rs:4:13
-   |
-   = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-note: erroneous constant encountered
-  --> $DIR/const-expr-generic-err.rs:4:5
-   |
-LL |     const { assert!(std::mem::size_of::<T>() == 0); }
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-note: the above error was encountered while instantiating `fn foo::<i32>`
-  --> $DIR/const-expr-generic-err.rs:12:5
-   |
-LL |     foo::<i32>();
-   |     ^^^^^^^^^^^^
-
 error[E0080]: evaluation of `bar::<0>::{constant#0}` failed
   --> $DIR/const-expr-generic-err.rs:8:13
    |
@@ -44,6 +24,26 @@ note: the above error was encountered while instantiating `fn bar::<0>`
 LL |     bar::<0>();
    |     ^^^^^^^^^^
 
+error[E0080]: evaluation of `foo::<i32>::{constant#0}` failed
+  --> $DIR/const-expr-generic-err.rs:4:13
+   |
+LL |     const { assert!(std::mem::size_of::<T>() == 0); }
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'assertion failed: std::mem::size_of::<T>() == 0', $DIR/const-expr-generic-err.rs:4:13
+   |
+   = note: this error originates in the macro `assert` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+note: erroneous constant encountered
+  --> $DIR/const-expr-generic-err.rs:4:5
+   |
+LL |     const { assert!(std::mem::size_of::<T>() == 0); }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+note: the above error was encountered while instantiating `fn foo::<i32>`
+  --> $DIR/const-expr-generic-err.rs:12:5
+   |
+LL |     foo::<i32>();
+   |     ^^^^^^^^^^^^
+
 error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.
diff --git a/tests/ui/type_length_limit.stderr b/tests/ui/type_length_limit.stderr
@@ -1,3 +1,7 @@
+error: reached the type-length limit while instantiating `<{closure@rt::lang_start<()>::{closure#0}} as FnMut<()>>::call_mut`
+   |
+   = help: consider adding a `#![type_length_limit="10"]` attribute to your crate
+
 error: reached the type-length limit while instantiating `std::mem::drop::<Option<((((..., ..., ...), ..., ...), ..., ...), ..., ...)>>`
   --> $DIR/type_length_limit.rs:32:5
    |
@@ -7,9 +11,5 @@ LL |     drop::<Option<A>>(None);
    = help: consider adding a `#![type_length_limit="4010"]` attribute to your crate
    = note: the full type name has been written to '$TEST_BUILD_DIR/type_length_limit/type_length_limit.long-type.txt'
 
-error: reached the type-length limit while instantiating `<{closure@rt::lang_start<()>::{closure#0}} as FnMut<()>>::call_mut`
-   |
-   = help: consider adding a `#![type_length_limit="10"]` attribute to your crate
-
 error: aborting due to 2 previous errors