Rollup of 5 pull requests

compiler/rustc_codegen_ssa/src/base.rs

@@ -29,8 +29,8 @@ use rustc_middle::middle::debugger_visualizer::{DebuggerVisualizerFile, Debugger
 use rustc_middle::middle::exported_symbols;
 use rustc_middle::middle::exported_symbols::SymbolExportKind;
 use rustc_middle::middle::lang_items;
-use rustc_middle::mir::BinOp;
 use rustc_middle::mir::mono::{CodegenUnit, CodegenUnitNameBuilder, MonoItem};
+use rustc_middle::mir::BinOp;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::layout::{HasTyCtxt, LayoutOf, TyAndLayout};
 use rustc_middle::ty::{self, Instance, Ty, TyCtxt};

compiler/rustc_const_eval/src/const_eval/error.rs

@@ -139,10 +139,9 @@ where
             ErrorHandled::TooGeneric(span)
         }
         err_inval!(AlreadyReported(guar)) => ErrorHandled::Reported(guar, span),
-        err_inval!(Layout(LayoutError::ReferencesError(guar))) => ErrorHandled::Reported(
-            ReportedErrorInfo::tainted_by_errors(guar),
-            span,
-        ),
+        err_inval!(Layout(LayoutError::ReferencesError(guar))) => {
+            ErrorHandled::Reported(ReportedErrorInfo::tainted_by_errors(guar), span)
+        }
         // Report remaining errors.
         _ => {
             let (our_span, frames) = get_span_and_frames();

compiler/rustc_incremental/src/persist/load.rs

@@ -116,8 +116,7 @@ fn load_dep_graph(sess: &Session) -> LoadResult<(Arc<SerializedDepGraph>, WorkPr
 
         if let LoadResult::Ok { data: (work_products_data, start_pos) } = load_result {
             // Decode the list of work_products
-            let Ok(mut work_product_decoder) =
-                MemDecoder::new(&work_products_data[..], start_pos)
+            let Ok(mut work_product_decoder) = MemDecoder::new(&work_products_data[..], start_pos)
             else {
                 sess.dcx().emit_warn(errors::CorruptFile { path: &work_products_path });
                 return LoadResult::DataOutOfDate;

compiler/rustc_infer/src/infer/mod.rs

@@ -957,27 +957,14 @@ impl<'tcx> InferCtxt<'tcx> {
             (&ty::Infer(ty::TyVar(a_vid)), &ty::Infer(ty::TyVar(b_vid))) => {
                 return Err((a_vid, b_vid));
             }
-            // We don't silently want to constrain hidden types here, so we assert that either one side is
-            // an infer var, so it'll get constrained to whatever the other side is, or there are no opaque
-            // types involved.
-            // We don't expect this to actually get hit, but if it does, we now at least know how to write
-            // a test for it.
-            (_, ty::Infer(ty::TyVar(_))) => {}
-            (ty::Infer(ty::TyVar(_)), _) => {}
-            _ if r_a != r_b && (r_a, r_b).has_opaque_types() => {
-                span_bug!(
-                    cause.span(),
-                    "opaque types got hidden types registered from within subtype predicate: {r_a:?} vs {r_b:?}"
-                )
-            }
             _ => {}
         }
 
         self.enter_forall(predicate, |ty::SubtypePredicate { a_is_expected, a, b }| {
             if a_is_expected {
-                Ok(self.at(cause, param_env).sub(DefineOpaqueTypes::Yes, a, b))
+                Ok(self.at(cause, param_env).sub(DefineOpaqueTypes::No, a, b))
             } else {
-                Ok(self.at(cause, param_env).sup(DefineOpaqueTypes::Yes, b, a))
+                Ok(self.at(cause, param_env).sup(DefineOpaqueTypes::No, b, a))
             }
         })
     }

compiler/rustc_lint/src/for_loops_over_fallibles.rs

@@ -62,7 +62,9 @@ impl<'tcx> LateLintPass<'tcx> for ForLoopsOverFallibles {
         };
 
         let (article, ty, var) = match adt.did() {
-            did if cx.tcx.is_diagnostic_item(sym::Option, did) && ref_mutability.is_some() => ("a", "Option", "Some"),
+            did if cx.tcx.is_diagnostic_item(sym::Option, did) && ref_mutability.is_some() => {
+                ("a", "Option", "Some")
+            }
             did if cx.tcx.is_diagnostic_item(sym::Option, did) => ("an", "Option", "Some"),
             did if cx.tcx.is_diagnostic_item(sym::Result, did) => ("a", "Result", "Ok"),
             _ => return,

library/core/src/cmp.rs

@@ -898,6 +898,7 @@ pub trait Ord: Eq + PartialOrd<Self> {
     /// assert_eq!(2.clamp(-2, 1), 1);
     /// ```
     #[must_use]
+    #[inline]
     #[stable(feature = "clamp", since = "1.50.0")]
     fn clamp(self, min: Self, max: Self) -> Self
     where

library/test/src/bench.rs

@@ -98,7 +98,7 @@ fn fmt_thousands_sep(mut n: f64, sep: char) -> String {
                 (0, true) => write!(output, "{:06.2}", n / base as f64).unwrap(),
                 (0, false) => write!(output, "{:.2}", n / base as f64).unwrap(),
                 (_, true) => write!(output, "{:03}", n as usize / base).unwrap(),
-                _ => write!(output,  "{}", n as usize / base).unwrap()
+                _ => write!(output, "{}", n as usize / base).unwrap(),
             }
             if pow != 0 {
                 output.push(sep);

src/bootstrap/README.md

@@ -6,7 +6,7 @@ and some of the technical details of the build system.
 Note that this README only covers internal information, not how to use the tool.
 Please check [bootstrapping dev guide][bootstrapping-dev-guide] for further information.
 
-[bootstrapping-dev-guide]: https://rustc-dev-guide.rust-lang.org/building/bootstrapping.html
+[bootstrapping-dev-guide]: https://rustc-dev-guide.rust-lang.org/building/bootstrapping/intro.html
 
 ## Introduction
 

src/bootstrap/src/core/builder/tests.rs

@@ -60,7 +60,14 @@ fn check_cli<const N: usize>(paths: [&str; N]) {
 macro_rules! std {
     ($host:ident => $target:ident, stage = $stage:literal) => {
         compile::Std::new(
-            Compiler { host: TargetSelection::from_user(concat!(stringify!($host), "-", stringify!($host))), stage: $stage },
+            Compiler {
+                host: TargetSelection::from_user(concat!(
+                    stringify!($host),
+                    "-",
+                    stringify!($host)
+                )),
+                stage: $stage,
+            },
             TargetSelection::from_user(concat!(stringify!($target), "-", stringify!($target))),
         )
     };
@@ -83,7 +90,14 @@ macro_rules! doc_std {
 macro_rules! rustc {
     ($host:ident => $target:ident, stage = $stage:literal) => {
         compile::Rustc::new(
-            Compiler { host: TargetSelection::from_user(concat!(stringify!($host), "-", stringify!($host))), stage: $stage },
+            Compiler {
+                host: TargetSelection::from_user(concat!(
+                    stringify!($host),
+                    "-",
+                    stringify!($host)
+                )),
+                stage: $stage,
+            },
             TargetSelection::from_user(concat!(stringify!($target), "-", stringify!($target))),
         )
     };
@@ -141,10 +155,14 @@ fn check_missing_paths_for_x_test_tests() {
 
         // Skip if not a test directory.
         if path.ends_with("tests/auxiliary") || !path.is_dir() {
-            continue
+            continue;
         }
 
-        assert!(tests_remap_paths.iter().any(|item| path.ends_with(*item)), "{} is missing in PATH_REMAP tests list.", path.display());
+        assert!(
+            tests_remap_paths.iter().any(|item| path.ends_with(*item)),
+            "{} is missing in PATH_REMAP tests list.",
+            path.display()
+        );
     }
 }
 
@@ -185,7 +203,8 @@ fn alias_and_path_for_library() {
         &[std!(A => A, stage = 0), std!(A => A, stage = 1)]
     );
 
-    let mut cache = run_build(&["library".into(), "core".into()], configure("doc", &["A-A"], &["A-A"]));
+    let mut cache =
+        run_build(&["library".into(), "core".into()], configure("doc", &["A-A"], &["A-A"]));
     assert_eq!(first(cache.all::<doc::Std>()), &[doc_std!(A => A, stage = 0)]);
 }
 

src/bootstrap/src/core/sanity.rs

@@ -199,11 +199,15 @@ than building it.
         if !["A-A", "B-B", "C-C"].contains(&target_str.as_str()) {
             let mut has_target = false;
 
-            let missing_targets_hashset: HashSet<_> = STAGE0_MISSING_TARGETS.iter().map(|t| t.to_string()).collect();
-            let duplicated_targets: Vec<_> = stage0_supported_target_list.intersection(&missing_targets_hashset).collect();
+            let missing_targets_hashset: HashSet<_> =
+                STAGE0_MISSING_TARGETS.iter().map(|t| t.to_string()).collect();
+            let duplicated_targets: Vec<_> =
+                stage0_supported_target_list.intersection(&missing_targets_hashset).collect();
 
             if !duplicated_targets.is_empty() {
-                println!("Following targets supported from the stage0 compiler, please remove them from STAGE0_MISSING_TARGETS list.");
+                println!(
+                    "Following targets supported from the stage0 compiler, please remove them from STAGE0_MISSING_TARGETS list."
+                );
                 for duplicated_target in duplicated_targets {
                     println!("  {duplicated_target}");
                 }

src/tools/build_helper/src/lib.rs

@@ -1,5 +1,5 @@
 pub mod ci;
 pub mod git;
 pub mod metrics;
-pub mod util;
 pub mod stage0_parser;
+pub mod util;

tests/ui/impl-trait/lazy_subtyping_of_opaques.rs

@@ -0,0 +1,59 @@
+//! This test checks that we allow subtyping predicates that contain opaque types.
+//! No hidden types are being constrained in the subtyping predicate, but type and
+//! lifetime variables get subtyped in the generic parameter list of the opaque.
+
+use std::iter;
+
+mod either {
+    pub enum Either<L, R> {
+        Left(L),
+        Right(R),
+    }
+
+    impl<L: Iterator, R: Iterator<Item = L::Item>> Iterator for Either<L, R> {
+        type Item = L::Item;
+        fn next(&mut self) -> Option<Self::Item> {
+            todo!()
+        }
+    }
+    pub use self::Either::{Left, Right};
+}
+
+pub enum BabeConsensusLogRef<'a> {
+    NextEpochData(BabeNextEpochRef<'a>),
+    NextConfigData,
+}
+
+impl<'a> BabeConsensusLogRef<'a> {
+    pub fn scale_encoding(
+        &self,
+    ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
+        //~^ ERROR is not satisfied
+        //~| ERROR is not satisfied
+        //~| ERROR is not satisfied
+        match self {
+            BabeConsensusLogRef::NextEpochData(digest) => either::Left(either::Left(
+                digest.scale_encoding().map(either::Left).map(either::Left),
+            )),
+            BabeConsensusLogRef::NextConfigData => either::Right(
+                // The Opaque type from ``scale_encoding` gets used opaquely here, while the `R`
+                // generic parameter of `Either` contains type variables that get subtyped and the
+                // opaque type contains lifetime variables that get subtyped.
+                iter::once(either::Right(either::Left([1])))
+                    .chain(std::iter::once([1]).map(either::Right).map(either::Right)),
+            ),
+        }
+    }
+}
+
+pub struct BabeNextEpochRef<'a>(&'a ());
+
+impl<'a> BabeNextEpochRef<'a> {
+    pub fn scale_encoding(
+        &self,
+    ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
+        std::iter::once([1])
+    }
+}
+
+fn main() {}

tests/ui/impl-trait/lazy_subtyping_of_opaques.stderr

@@ -0,0 +1,21 @@
+error[E0277]: the trait bound `Either<Either<Map<Map<impl Iterator<Item = impl AsRef<[u8]> + Clone + '_> + Clone + '_, fn(impl AsRef<[u8]> + Clone + '_) -> Either<impl AsRef<[u8]> + Clone + '_, _> {Either::<impl AsRef<[u8]> + Clone + '_, _>::Left}>, fn(Either<impl AsRef<[u8]> + Clone + '_, _>) -> Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>> {Either::<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>::Left}>, _>, std::iter::Chain<std::iter::Once<Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>>, Map<Map<std::iter::Once<[{integer}; 1]>, fn([{integer}; 1]) -> Either<[{integer}; 1], [{integer}; 1]> {Either::<[{integer}; 1], [{integer}; 1]>::Right}>, fn(Either<[{integer}; 1], [{integer}; 1]>) -> Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>> {Either::<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>::Right}>>>: Clone` is not satisfied
+  --> $DIR/lazy_subtyping_of_opaques.rs:30:10
+   |
+LL |     ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
+   |          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Either<Either<Map<Map<impl Iterator<Item = impl AsRef<[u8]> + Clone + '_> + Clone + '_, fn(impl AsRef<[u8]> + Clone + '_) -> Either<impl AsRef<[u8]> + Clone + '_, _> {Either::<impl AsRef<[u8]> + Clone + '_, _>::Left}>, fn(Either<impl AsRef<[u8]> + Clone + '_, _>) -> Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>> {Either::<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>::Left}>, _>, std::iter::Chain<std::iter::Once<Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>>, Map<Map<std::iter::Once<[{integer}; 1]>, fn([{integer}; 1]) -> Either<[{integer}; 1], [{integer}; 1]> {Either::<[{integer}; 1], [{integer}; 1]>::Right}>, fn(Either<[{integer}; 1], [{integer}; 1]>) -> Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>> {Either::<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>::Right}>>>`
+
+error[E0277]: the trait bound `Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>: AsRef<[u8]>` is not satisfied
+  --> $DIR/lazy_subtyping_of_opaques.rs:30:31
+   |
+LL |     ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `AsRef<[u8]>` is not implemented for `Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>`
+
+error[E0277]: the trait bound `Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>: Clone` is not satisfied
+  --> $DIR/lazy_subtyping_of_opaques.rs:30:31
+   |
+LL |     ) -> impl Iterator<Item = impl AsRef<[u8]> + Clone + 'a> + Clone + 'a {
+   |                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Clone` is not implemented for `Either<Either<impl AsRef<[u8]> + Clone + '_, _>, Either<[{integer}; 1], [{integer}; 1]>>`
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0277`.

tests/ui/type-alias-impl-trait/lazy_subtyping_of_opaques.rs

@@ -0,0 +1,30 @@
+#![feature(type_alias_impl_trait)]
+
+//! This test used to ICE rust-lang/rust#124891
+//! because we added an assertion for catching cases where opaque types get
+//! registered during the processing of subtyping predicates.
+
+type Tait = impl FnOnce() -> ();
+
+fn reify_as_tait() -> Thunk<Tait> {
+    Thunk::new(|cont| cont)
+    //~^ ERROR: mismatched types
+    //~| ERROR: mismatched types
+}
+
+struct Thunk<F>(F);
+
+impl<F> Thunk<F> {
+    fn new(f: F)
+    where
+        F: ContFn,
+    {
+        todo!();
+    }
+}
+
+trait ContFn {}
+
+impl<F: FnOnce(Tait) -> ()> ContFn for F {}
+
+fn main() {}

tests/ui/type-alias-impl-trait/lazy_subtyping_of_opaques.stderr

@@ -0,0 +1,26 @@
+error[E0308]: mismatched types
+  --> $DIR/lazy_subtyping_of_opaques.rs:10:23
+   |
+LL | type Tait = impl FnOnce() -> ();
+   |             ------------------- the found opaque type
+...
+LL |     Thunk::new(|cont| cont)
+   |                       ^^^^ expected `()`, found opaque type
+   |
+   = note: expected unit type `()`
+            found opaque type `Tait`
+
+error[E0308]: mismatched types
+  --> $DIR/lazy_subtyping_of_opaques.rs:10:5
+   |
+LL | fn reify_as_tait() -> Thunk<Tait> {
+   |                       ----------- expected `Thunk<_>` because of return type
+LL |     Thunk::new(|cont| cont)
+   |     ^^^^^^^^^^^^^^^^^^^^^^^ expected `Thunk<_>`, found `()`
+   |
+   = note: expected struct `Thunk<_>`
+           found unit type `()`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

triagebot.toml

@@ -842,6 +842,9 @@ cc = ["@Zalathar"]
 message = "Some changes occurred in coverage tests."
 cc = ["@Zalathar"]
 
+[mentions."src/tools/opt-dist"]
+cc = ["@kobzol"]
+
 [assign]
 warn_non_default_branch = true
 contributing_url = "https://rustc-dev-guide.rust-lang.org/getting-started.html"
@@ -1059,6 +1062,7 @@ project-exploit-mitigations = [
 "/src/tools/cargo" =                                     ["@ehuss"]
 "/src/tools/compiletest" =                               ["bootstrap", "@wesleywiser", "@oli-obk", "@compiler-errors", "@jieyouxu"]
 "/src/tools/linkchecker" =                               ["@ehuss"]
+"/src/tools/opt-dist" =                                  ["@kobzol"]
 "/src/tools/run-make-support" =                          ["@jieyouxu"]
 "/src/tools/rust-installer" =                            ["bootstrap"]
 "/src/tools/rustbook" =                                  ["@ehuss"]