Auto merge of rust-lang#104877 - matthiaskrgr:rollup-s7taiq8, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - rust-lang#103648 (Don't set `is_preview` for clippy and rustfmt)
 - rust-lang#104654 (Add `#![deny(unsafe_op_in_unsafe_fn)]` in liballoc tests)
 - rust-lang#104793 (unstable-book: Add page for the `abi_efiapi` feature)
 - rust-lang#104841 (Assert that we don't capture escaping bound vars in `Fn` trait selection)
 - rust-lang#104849 (Migrate source code elements style to CSS variables)
 - rust-lang#104873 (RefCell::get_mut: fix typo)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_trait_selection/src/traits/select/confirmation.rs

@@ -605,8 +605,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
     {
         debug!(?obligation, "confirm_fn_pointer_candidate");
 
-        // Okay to skip binder; it is reintroduced below.
-        let self_ty = self.infcx.shallow_resolve(obligation.self_ty().skip_binder());
+        let self_ty = self
+            .infcx
+            .shallow_resolve(obligation.self_ty().no_bound_vars())
+            .expect("fn pointer should not capture bound vars from predicate");
         let sig = self_ty.fn_sig(self.tcx());
         let trait_ref = closure_trait_ref_and_return_type(
             self.tcx(),
@@ -621,15 +623,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
         // Confirm the `type Output: Sized;` bound that is present on `FnOnce`
         let cause = obligation.derived_cause(BuiltinDerivedObligation);
-        // The binder on the Fn obligation is "less" important than the one on
-        // the signature, as evidenced by how we treat it during projection.
-        // The safe thing to do here is to liberate it, though, which should
-        // have no worse effect than skipping the binder here.
-        let liberated_fn_ty =
-            self.infcx.replace_bound_vars_with_placeholders(obligation.predicate.rebind(self_ty));
-        let output_ty = self
-            .infcx
-            .replace_bound_vars_with_placeholders(liberated_fn_ty.fn_sig(self.tcx()).output());
+        let output_ty = self.infcx.replace_bound_vars_with_placeholders(sig.output());
         let output_ty = normalize_with_depth_to(
             self,
             obligation.param_env,
@@ -693,16 +687,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
         let gen_sig = substs.as_generator().poly_sig();
 
-        // (1) Feels icky to skip the binder here, but OTOH we know
-        // that the self-type is an generator type and hence is
+        // NOTE: The self-type is a generator type and hence is
         // in fact unparameterized (or at least does not reference any
-        // regions bound in the obligation). Still probably some
-        // refactoring could make this nicer.
+        // regions bound in the obligation).
+        let self_ty = obligation
+            .predicate
+            .self_ty()
+            .no_bound_vars()
+            .expect("unboxed closure type should not capture bound vars from the predicate");
 
         let trait_ref = super::util::generator_trait_ref_and_outputs(
             self.tcx(),
             obligation.predicate.def_id(),
-            obligation.predicate.skip_binder().self_ty(), // (1)
+            self_ty,
             gen_sig,
         )
         .map_bound(|(trait_ref, ..)| trait_ref);

compiler/rustc_trait_selection/src/traits/select/mod.rs

@@ -2271,15 +2271,19 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
 
         debug!(?closure_sig);
 
-        // (1) Feels icky to skip the binder here, but OTOH we know
-        // that the self-type is an unboxed closure type and hence is
+        // NOTE: The self-type is an unboxed closure type and hence is
         // in fact unparameterized (or at least does not reference any
-        // regions bound in the obligation). Still probably some
-        // refactoring could make this nicer.
+        // regions bound in the obligation).
+        let self_ty = obligation
+            .predicate
+            .self_ty()
+            .no_bound_vars()
+            .expect("unboxed closure type should not capture bound vars from the predicate");
+
         closure_trait_ref_and_return_type(
             self.tcx(),
             obligation.predicate.def_id(),
-            obligation.predicate.skip_binder().self_ty(), // (1)
+            self_ty,
             closure_sig,
             util::TupleArgumentsFlag::No,
         )

compiler/rustc_trait_selection/src/traits/util.rs

@@ -298,11 +298,11 @@ pub fn closure_trait_ref_and_return_type<'tcx>(
     sig: ty::PolyFnSig<'tcx>,
     tuple_arguments: TupleArgumentsFlag,
 ) -> ty::Binder<'tcx, (ty::TraitRef<'tcx>, Ty<'tcx>)> {
+    assert!(!self_ty.has_escaping_bound_vars());
     let arguments_tuple = match tuple_arguments {
         TupleArgumentsFlag::No => sig.skip_binder().inputs()[0],
         TupleArgumentsFlag::Yes => tcx.intern_tup(sig.skip_binder().inputs()),
     };
-    debug_assert!(!self_ty.has_escaping_bound_vars());
     let trait_ref = tcx.mk_trait_ref(fn_trait_def_id, [self_ty, arguments_tuple]);
     sig.map_bound(|sig| (trait_ref, sig.output()))
 }
@@ -313,7 +313,7 @@ pub fn generator_trait_ref_and_outputs<'tcx>(
     self_ty: Ty<'tcx>,
     sig: ty::PolyGenSig<'tcx>,
 ) -> ty::Binder<'tcx, (ty::TraitRef<'tcx>, Ty<'tcx>, Ty<'tcx>)> {
-    debug_assert!(!self_ty.has_escaping_bound_vars());
+    assert!(!self_ty.has_escaping_bound_vars());
     let trait_ref = tcx.mk_trait_ref(fn_trait_def_id, [self_ty, sig.skip_binder().resume_ty]);
     sig.map_bound(|sig| (trait_ref, sig.yield_ty, sig.return_ty))
 }
@@ -324,7 +324,7 @@ pub fn future_trait_ref_and_outputs<'tcx>(
     self_ty: Ty<'tcx>,
     sig: ty::PolyGenSig<'tcx>,
 ) -> ty::Binder<'tcx, (ty::TraitRef<'tcx>, Ty<'tcx>)> {
-    debug_assert!(!self_ty.has_escaping_bound_vars());
+    assert!(!self_ty.has_escaping_bound_vars());
     let trait_ref = tcx.mk_trait_ref(fn_trait_def_id, [self_ty]);
     sig.map_bound(|sig| (trait_ref, sig.return_ty))
 }

library/alloc/tests/boxed.rs

@@ -102,8 +102,18 @@ unsafe impl const Allocator for ConstAllocator {
 
         let new_ptr = self.allocate(new_layout)?;
         if new_layout.size() > 0 {
-            new_ptr.as_mut_ptr().copy_from_nonoverlapping(ptr.as_ptr(), old_layout.size());
-            self.deallocate(ptr, old_layout);
+            // Safety: `new_ptr` is valid for writes and `ptr` for reads of
+            // `old_layout.size()`, because `new_layout.size() >=
+            // old_layout.size()` (which is an invariant that must be upheld by
+            // callers).
+            unsafe {
+                new_ptr.as_mut_ptr().copy_from_nonoverlapping(ptr.as_ptr(), old_layout.size());
+            }
+            // Safety: `ptr` is never used again is also an invariant which must
+            // be upheld by callers.
+            unsafe {
+                self.deallocate(ptr, old_layout);
+            }
         }
         Ok(new_ptr)
     }
@@ -114,12 +124,21 @@ unsafe impl const Allocator for ConstAllocator {
         old_layout: Layout,
         new_layout: Layout,
     ) -> Result<NonNull<[u8]>, AllocError> {
-        let new_ptr = self.grow(ptr, old_layout, new_layout)?;
+        // Safety: Invariants of `grow_zeroed` and `grow` are the same, and must
+        // be enforced by callers.
+        let new_ptr = unsafe { self.grow(ptr, old_layout, new_layout)? };
         if new_layout.size() > 0 {
             let old_size = old_layout.size();
             let new_size = new_layout.size();
             let raw_ptr = new_ptr.as_mut_ptr();
-            raw_ptr.add(old_size).write_bytes(0, new_size - old_size);
+            // Safety:
+            // - `grow` returned Ok, so the returned pointer must be valid for
+            //   `new_size` bytes
+            // - `new_size` must be larger than `old_size`, which is an
+            //   invariant which must be upheld by callers.
+            unsafe {
+                raw_ptr.add(old_size).write_bytes(0, new_size - old_size);
+            }
         }
         Ok(new_ptr)
     }
@@ -137,8 +156,18 @@ unsafe impl const Allocator for ConstAllocator {
 
         let new_ptr = self.allocate(new_layout)?;
         if new_layout.size() > 0 {
-            new_ptr.as_mut_ptr().copy_from_nonoverlapping(ptr.as_ptr(), new_layout.size());
-            self.deallocate(ptr, old_layout);
+            // Safety: `new_ptr` and `ptr` are valid for reads/writes of
+            // `new_layout.size()` because of the invariants of shrink, which
+            // include `new_layout.size()` being smaller than (or equal to)
+            // `old_layout.size()`.
+            unsafe {
+                new_ptr.as_mut_ptr().copy_from_nonoverlapping(ptr.as_ptr(), new_layout.size());
+            }
+            // Safety: `ptr` is never used again is also an invariant which must
+            // be upheld by callers.
+            unsafe {
+                self.deallocate(ptr, old_layout);
+            }
         }
         Ok(new_ptr)
     }

library/alloc/tests/lib.rs

@@ -48,6 +48,7 @@
 #![feature(once_cell)]
 #![feature(drain_keep_rest)]
 #![deny(fuzzy_provenance_casts)]
+#![deny(unsafe_op_in_unsafe_fn)]
 
 use std::collections::hash_map::DefaultHasher;
 use std::hash::{Hash, Hasher};

library/alloc/tests/vec.rs

@@ -1089,7 +1089,8 @@ fn test_into_iter_drop_allocator() {
         }
 
         unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
-            System.deallocate(ptr, layout)
+            // Safety: Invariants passed to caller.
+            unsafe { System.deallocate(ptr, layout) }
         }
     }
 

library/core/src/cell.rs

@@ -1025,7 +1025,7 @@ impl<T: ?Sized> RefCell<T> {
     ///
     /// Since this method borrows `RefCell` mutably, it is statically guaranteed
     /// that no borrows to the underlying data exist. The dynamic checks inherent
-    /// in [`borrow_mut`] and most other methods of `RefCell` are therefor
+    /// in [`borrow_mut`] and most other methods of `RefCell` are therefore
     /// unnecessary.
     ///
     /// This method can only be called if `RefCell` can be mutably borrowed,

src/bootstrap/dist.rs

@@ -1191,7 +1191,6 @@ impl Step for Clippy {
 
         let mut tarball = Tarball::new(builder, "clippy", &target.triple);
         tarball.set_overlay(OverlayKind::Clippy);
-        tarball.is_preview(true);
         tarball.add_file(clippy, "bin", 0o755);
         tarball.add_file(cargoclippy, "bin", 0o755);
         tarball.add_legal_and_readme_to("share/doc/clippy");
@@ -1289,7 +1288,6 @@ impl Step for Rustfmt {
             .expect("cargo fmt expected to build - essential tool");
         let mut tarball = Tarball::new(builder, "rustfmt", &target.triple);
         tarball.set_overlay(OverlayKind::Rustfmt);
-        tarball.is_preview(true);
         tarball.add_file(rustfmt, "bin", 0o755);
         tarball.add_file(cargofmt, "bin", 0o755);
         tarball.add_legal_and_readme_to("share/doc/rustfmt");
@@ -1550,8 +1548,6 @@ impl Step for Extended {
                     format!("{}-{}", name, target.triple)
                 } else if name == "rust-analyzer" {
                     "rust-analyzer-preview".to_string()
-                } else if name == "clippy" {
-                    "clippy-preview".to_string()
                 } else if name == "rust-demangler" {
                     "rust-demangler-preview".to_string()
                 } else if name == "miri" {

src/bootstrap/download.rs

@@ -326,6 +326,8 @@ impl Config {
         }
 
         let filename = format!("rustfmt-{version}-{build}.tar.xz", build = host.triple);
+        // cfg(bootstrap): will need to be changed from `rustfmt-preview` to `rustfmt` the next time you run `bump-stage0`.
+        // See <https://github.com/rust-lang/rust/pull/103648>
         self.download_component(DownloadSource::Dist, filename, "rustfmt-preview", &date, "stage0");
 
         self.fix_bin_or_dylib(&bin_root.join("bin").join("rustfmt"));

src/doc/unstable-book/src/language-features/abi-efiapi.md

@@ -0,0 +1,23 @@
+# `abi_efiapi`
+
+The tracking issue for this feature is: [#65815]
+
+[#65815]: https://github.com/rust-lang/rust/issues/65815
+
+------------------------
+
+The `efiapi` calling convention can be used for defining a function with
+an ABI compatible with the UEFI Interfaces as defined in the [UEFI
+Specification].
+
+Example:
+
+```rust
+#![feature(abi_efiapi)]
+
+extern "efiapi" { fn f1(); }
+
+extern "efiapi" fn f2() { todo!() }
+```
+
+[UEFI Specification]: https://uefi.org/specs/UEFI/2.10/