Auto merge of #87540 - JohnTitor:rollup-8xc6bl5, r=JohnTitor

Rollup of 10 pull requests

Successful merges:

 - #87315 (Add docs for raw-dylib to unstable book)
 - #87330 (Use hashbrown's `extend_reserve()` in `HashMap`)
 - #87443 (Don't treat git repos as non-existent when `ignore_git` is set)
 - #87453 (Suggest removing unnecessary &mut as help message)
 - #87500 (Document math behind MIN/MAX consts on integers)
 - #87501 (Remove min_type_alias_impl_trait in favor of type_alias_impl_trait)
 - #87507 (SGX mutex is *not* moveable)
 - #87513 (bootstrap.py: change `git log` option to indicate desired behavior)
 - #87523 (Stop creating a reference then immediately dereferencing it.)
 - #87524 (Fix ICE in `diagnostic_hir_wf_check`)

Failed merges:

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

Author: bors

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -287,7 +287,7 @@ impl<'a> PostExpansionVisitor<'a> {
                 if let ast::TyKind::ImplTrait(..) = ty.kind {
                     gate_feature_post!(
                         &self.vis,
-                        min_type_alias_impl_trait,
+                        type_alias_impl_trait,
                         ty.span,
                         "`impl Trait` in type aliases is unstable"
                     );

compiler/rustc_data_structures/src/lib.rs

@@ -21,7 +21,8 @@
 #![feature(iter_map_while)]
 #![feature(maybe_uninit_uninit_array)]
 #![feature(min_specialization)]
-#![feature(min_type_alias_impl_trait)]
+#![cfg_attr(bootstrap, feature(min_type_alias_impl_trait))]
+#![cfg_attr(not(bootstrap), feature(type_alias_impl_trait))]
 #![feature(new_uninit)]
 #![feature(nll)]
 #![feature(once_cell)]

compiler/rustc_feature/src/active.rs

@@ -486,7 +486,7 @@ declare_features! (
     (active, async_closure, "1.37.0", Some(62290), None),
 
     /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
-    (incomplete, type_alias_impl_trait, "1.38.0", Some(63063), None),
+    (active, type_alias_impl_trait, "1.38.0", Some(63063), None),
 
     /// Allows the definition of `const extern fn` and `const unsafe extern fn`.
     (active, const_extern_fn, "1.40.0", Some(64926), None),
@@ -619,9 +619,6 @@ declare_features! (
     /// Allows macro attributes to observe output of `#[derive]`.
     (active, macro_attributes_in_derive_output, "1.51.0", Some(81119), None),
 
-    /// Allows the use of type alias impl trait in function return positions
-    (active, min_type_alias_impl_trait, "1.52.0", Some(63063), None),
-
     /// Allows associated types in inherent impls.
     (incomplete, inherent_associated_types, "1.52.0", Some(8995), None),
 

compiler/rustc_feature/src/removed.rs

@@ -111,7 +111,7 @@ declare_features! (
      Some("subsumed by `.await` syntax")),
     /// Allows defining `existential type`s.
     (removed, existential_type, "1.38.0", Some(63063), None,
-     Some("removed in favor of `#![feature(min_type_alias_impl_trait)]`")),
+     Some("removed in favor of `#![feature(type_alias_impl_trait)]`")),
     /// Allows using the macros:
     /// + `__diagnostic_used`
     /// + `__register_diagnostic`
@@ -152,6 +152,10 @@ declare_features! (
     (removed, impl_trait_in_bindings, "1.55.0", Some(63065), None,
      Some("the implementation was not maintainable, the feature may get reintroduced once the current refactorings are done")),
 
+    /// Allows the use of type alias impl trait in function return positions
+    (removed, min_type_alias_impl_trait, "1.55.0", Some(63063), None,
+     Some("removed in favor of full type_alias_impl_trait")),
+
     // -------------------------------------------------------------------------
     // feature-group-end: removed features
     // -------------------------------------------------------------------------

compiler/rustc_mir/src/borrow_check/diagnostics/mutability_errors.rs

@@ -242,7 +242,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                     .unwrap_or(false) =>
             {
                 err.span_label(span, format!("cannot {ACT}", ACT = act));
-                err.span_label(span, "try removing `&mut` here");
+                err.span_suggestion(
+                    span,
+                    "try removing `&mut` here",
+                    String::new(),
+                    Applicability::MaybeIncorrect,
+                );
             }
 
             // We want to suggest users use `let mut` for local (user
@@ -324,7 +329,12 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 } =>
             {
                 err.span_label(span, format!("cannot {ACT}", ACT = act));
-                err.span_label(span, "try removing `&mut` here");
+                err.span_suggestion(
+                    span,
+                    "try removing `&mut` here",
+                    String::new(),
+                    Applicability::MaybeIncorrect,
+                );
             }
 
             PlaceRef { local, projection: [ProjectionElem::Deref] }

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

@@ -240,8 +240,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
 
         let mut err = match *error {
             SelectionError::Unimplemented => {
-                // If this obligation was generated as a result of well-formed checking, see if we
-                // can get a better error message by performing HIR-based well formed checking.
+                // If this obligation was generated as a result of well-formedness checking, see if we
+                // can get a better error message by performing HIR-based well-formedness checking.
                 if let ObligationCauseCode::WellFormed(Some(wf_loc)) =
                     root_obligation.cause.code.peel_derives()
                 {

compiler/rustc_typeck/src/hir_wf_check.rs

@@ -38,20 +38,20 @@ fn diagnostic_hir_wf_check<'tcx>(
     // given the type `Option<MyStruct<u8>>`, we will check
     // `Option<MyStruct<u8>>`, `MyStruct<u8>`, and `u8`.
     // For each type, we perform a well-formed check, and see if we get
-    // an erorr that matches our expected predicate. We keep save
+    // an error that matches our expected predicate. We save
     // the `ObligationCause` corresponding to the *innermost* type,
     // which is the most specific type that we can point to.
     // In general, the different components of an `hir::Ty` may have
-    // completely differentr spans due to macro invocations. Pointing
+    // completely different spans due to macro invocations. Pointing
     // to the most accurate part of the type can be the difference
     // between a useless span (e.g. the macro invocation site)
-    // and a useful span (e.g. a user-provided type passed in to the macro).
+    // and a useful span (e.g. a user-provided type passed into the macro).
     //
     // This approach is quite inefficient - we redo a lot of work done
     // by the normal WF checker. However, this code is run at most once
     // per reported error - it will have no impact when compilation succeeds,
-    // and should only have an impact if a very large number of errors are
-    // displaydd to the user.
+    // and should only have an impact if a very large number of errors is
+    // displayed to the user.
     struct HirWfCheck<'tcx> {
         tcx: TyCtxt<'tcx>,
         predicate: ty::Predicate<'tcx>,
@@ -126,10 +126,12 @@ fn diagnostic_hir_wf_check<'tcx>(
         WellFormedLoc::Ty(_) => match hir.get(hir_id) {
             hir::Node::ImplItem(item) => match item.kind {
                 hir::ImplItemKind::TyAlias(ty) => Some(ty),
+                hir::ImplItemKind::Const(ty, _) => Some(ty),
                 ref item => bug!("Unexpected ImplItem {:?}", item),
             },
             hir::Node::TraitItem(item) => match item.kind {
                 hir::TraitItemKind::Type(_, ty) => ty,
+                hir::TraitItemKind::Const(ty, _) => Some(ty),
                 ref item => bug!("Unexpected TraitItem {:?}", item),
             },
             hir::Node::Item(item) => match item.kind {

library/alloc/src/lib.rs

@@ -142,7 +142,8 @@
 #![feature(alloc_layout_extra)]
 #![feature(trusted_random_access)]
 #![feature(try_trait_v2)]
-#![feature(min_type_alias_impl_trait)]
+#![cfg_attr(bootstrap, feature(min_type_alias_impl_trait))]
+#![cfg_attr(not(bootstrap), feature(type_alias_impl_trait))]
 #![feature(associated_type_bounds)]
 #![feature(slice_group_by)]
 #![feature(decl_macro)]

library/core/src/num/int_macros.rs

@@ -1,9 +1,10 @@
 macro_rules! int_impl {
-    ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $Min:expr, $Max:expr,
+    ($SelfT:ty, $ActualT:ident, $UnsignedT:ty, $BITS:expr, $BITS_MINUS_ONE:expr, $Min:expr, $Max:expr,
      $rot:expr, $rot_op:expr, $rot_result:expr, $swap_op:expr, $swapped:expr,
      $reversed:expr, $le_bytes:expr, $be_bytes:expr,
      $to_xe_bytes_doc:expr, $from_xe_bytes_doc:expr) => {
-        /// The smallest value that can be represented by this integer type.
+        /// The smallest value that can be represented by this integer type,
+        #[doc = concat!("-2<sup>", $BITS_MINUS_ONE, "</sup>.")]
         ///
         /// # Examples
         ///
@@ -15,7 +16,8 @@ macro_rules! int_impl {
         #[stable(feature = "assoc_int_consts", since = "1.43.0")]
         pub const MIN: Self = !0 ^ ((!0 as $UnsignedT) >> 1) as Self;
 
-        /// The largest value that can be represented by this integer type.
+        /// The largest value that can be represented by this integer type,
+        #[doc = concat!("2<sup>", $BITS_MINUS_ONE, "</sup> - 1.")]
         ///
         /// # Examples
         ///

library/core/src/num/mod.rs

@@ -91,34 +91,34 @@ depending on the target pointer size.
 
 #[lang = "i8"]
 impl i8 {
-    int_impl! { i8, i8, u8, 8, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
+    int_impl! { i8, i8, u8, 8, 7, -128, 127, 2, "-0x7e", "0xa", "0x12", "0x12", "0x48",
     "[0x12]", "[0x12]", "", "" }
 }
 
 #[lang = "i16"]
 impl i16 {
-    int_impl! { i16, i16, u16, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
+    int_impl! { i16, i16, u16, 16, 15, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234", "0x3412",
     "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]", "", "" }
 }
 
 #[lang = "i32"]
 impl i32 {
-    int_impl! { i32, i32, u32, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
+    int_impl! { i32, i32, u32, 32, 31, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
     "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78]", "", "" }
 }
 
 #[lang = "i64"]
 impl i64 {
-    int_impl! { i64, i64, u64, 64, -9223372036854775808, 9223372036854775807, 12,
+    int_impl! { i64, i64, u64, 64, 63, -9223372036854775808, 9223372036854775807, 12,
     "0xaa00000000006e1", "0x6e10aa", "0x1234567890123456", "0x5634129078563412",
     "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]", "", "" }
 }
 
 #[lang = "i128"]
 impl i128 {
-    int_impl! { i128, i128, u128, 128, -170141183460469231731687303715884105728,
+    int_impl! { i128, i128, u128, 128, 127, -170141183460469231731687303715884105728,
     170141183460469231731687303715884105727, 16,
     "0x13f40000000000000000000000004f76", "0x4f7613f4", "0x12345678901234567890123456789012",
     "0x12907856341290785634129078563412", "0x48091e6a2c48091e6a2c48091e6a2c48",
@@ -131,15 +131,15 @@ impl i128 {
 #[cfg(target_pointer_width = "16")]
 #[lang = "isize"]
 impl isize {
-    int_impl! { isize, i16, usize, 16, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234",
+    int_impl! { isize, i16, usize, 16, 15, -32768, 32767, 4, "-0x5ffd", "0x3a", "0x1234",
     "0x3412", "0x2c48", "[0x34, 0x12]", "[0x12, 0x34]",
     usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
 }
 
 #[cfg(target_pointer_width = "32")]
 #[lang = "isize"]
 impl isize {
-    int_impl! { isize, i32, usize, 32, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
+    int_impl! { isize, i32, usize, 32, 31, -2147483648, 2147483647, 8, "0x10000b3", "0xb301",
     "0x12345678", "0x78563412", "0x1e6a2c48", "[0x78, 0x56, 0x34, 0x12]",
     "[0x12, 0x34, 0x56, 0x78]",
     usize_isize_to_xe_bytes_doc!(), usize_isize_from_xe_bytes_doc!() }
@@ -148,7 +148,7 @@ impl isize {
 #[cfg(target_pointer_width = "64")]
 #[lang = "isize"]
 impl isize {
-    int_impl! { isize, i64, usize, 64, -9223372036854775808, 9223372036854775807,
+    int_impl! { isize, i64, usize, 64, 63, -9223372036854775808, 9223372036854775807,
     12, "0xaa00000000006e1", "0x6e10aa",  "0x1234567890123456", "0x5634129078563412",
      "0x6a2c48091e6a2c48", "[0x56, 0x34, 0x12, 0x90, 0x78, 0x56, 0x34, 0x12]",
      "[0x12, 0x34, 0x56, 0x78, 0x90, 0x12, 0x34, 0x56]",

library/core/src/num/uint_macros.rs

@@ -15,7 +15,8 @@ macro_rules! uint_impl {
         #[stable(feature = "assoc_int_consts", since = "1.43.0")]
         pub const MIN: Self = 0;
 
-        /// The largest value that can be represented by this integer type.
+        /// The largest value that can be represented by this integer type,
+        #[doc = concat!("2<sup>", $BITS, "</sup> - 1.")]
         ///
         /// # Examples
         ///

library/core/src/ops/range.rs

@@ -812,12 +812,12 @@ pub trait RangeBounds<T: ?Sized> {
         U: ?Sized + PartialOrd<T>,
     {
         (match self.start_bound() {
-            Included(ref start) => *start <= item,
-            Excluded(ref start) => *start < item,
+            Included(start) => start <= item,
+            Excluded(start) => start < item,
             Unbounded => true,
         }) && (match self.end_bound() {
-            Included(ref end) => item <= *end,
-            Excluded(ref end) => item < *end,
+            Included(end) => item <= end,
+            Excluded(end) => item < end,
             Unbounded => true,
         })
     }

library/std/src/collections/hash/map.rs

@@ -2821,15 +2821,7 @@ where
 
     #[inline]
     fn extend_reserve(&mut self, additional: usize) {
-        // self.base.extend_reserve(additional);
-        // FIXME: hashbrown should implement this method.
-        // But until then, use the same reservation logic:
-
-        // Reserve the entire hint lower bound if the map is empty.
-        // Otherwise reserve half the hint (rounded up), so the map
-        // will only resize twice in the worst case.
-        let reserve = if self.is_empty() { additional } else { (additional + 1) / 2 };
-        self.base.reserve(reserve);
+        self.base.extend_reserve(additional);
     }
 }
 

library/std/src/sys/sgx/mutex.rs

@@ -8,7 +8,8 @@ pub struct Mutex {
     inner: SpinMutex<WaitVariable<bool>>,
 }
 
-pub type MovableMutex = Mutex;
+// not movable: see UnsafeList implementation
+pub type MovableMutex = Box<Mutex>;
 
 // Implementation according to “Operating Systems: Three Easy Pieces”, chapter 28
 impl Mutex {

library/std/src/sys/sgx/waitqueue/unsafe_list.rs

@@ -23,6 +23,7 @@ impl<T> UnsafeListEntry<T> {
     }
 }
 
+// WARNING: self-referential struct!
 pub struct UnsafeList<T> {
     head_tail: NonNull<UnsafeListEntry<T>>,
     head_tail_entry: Option<UnsafeListEntry<T>>,

src/bootstrap/bootstrap.py

@@ -473,7 +473,7 @@ def download_toolchain(self, stage0=True, rustc_channel=None):
             ]).decode(sys.getdefaultencoding()).strip()
             llvm_sha = subprocess.check_output([
                 "git", "log", "--author=bors", "--format=%H", "-n1",
-                "-m", "--first-parent",
+                "--no-patch", "--first-parent",
                 "--",
                 "{}/src/llvm-project".format(top_level),
                 "{}/src/bootstrap/download-ci-llvm-stamp".format(top_level),