Rollup of 12 pull requests

compiler/rustc_arena/src/lib.rs

@@ -11,7 +11,6 @@
     html_root_url = "https://doc.rust-lang.org/nightly/",
     test(no_crate_inject, attr(deny(warnings)))
 )]
-#![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(new_uninit)]
 #![feature(maybe_uninit_slice)]
@@ -24,7 +23,6 @@ use smallvec::SmallVec;
 use std::alloc::Layout;
 use std::cell::{Cell, RefCell};
 use std::cmp;
-use std::intrinsics;
 use std::marker::{PhantomData, Send};
 use std::mem::{self, MaybeUninit};
 use std::ptr;
@@ -122,7 +120,7 @@ impl<T> TypedArena<T> {
 
         unsafe {
             if mem::size_of::<T>() == 0 {
-                self.ptr.set(intrinsics::arith_offset(self.ptr.get() as *mut u8, 1) as *mut T);
+                self.ptr.set((self.ptr.get() as *mut u8).wrapping_offset(1) as *mut T);
                 let ptr = mem::align_of::<T>() as *mut T;
                 // Don't drop the object. This `write` is equivalent to `forget`.
                 ptr::write(ptr, object);

compiler/rustc_ast/src/lib.rs

@@ -5,17 +5,13 @@
 //! This API is completely unstable and subject to change.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/", test(attr(deny(warnings))))]
-#![feature(bool_to_option)]
 #![feature(box_syntax)]
 #![feature(const_fn)] // For the `transmute` in `P::new`
 #![feature(const_panic)]
-#![feature(const_fn_transmute)]
 #![feature(crate_visibility_modifier)]
 #![feature(label_break_value)]
 #![feature(nll)]
 #![feature(or_patterns)]
-#![feature(try_trait)]
-#![feature(unicode_internals)]
 #![recursion_limit = "256"]
 
 #[macro_use]

compiler/rustc_ast_lowering/src/item.rs

@@ -27,7 +27,7 @@ pub(super) struct ItemLowerer<'a, 'lowering, 'hir> {
 impl ItemLowerer<'_, '_, '_> {
     fn with_trait_impl_ref(&mut self, impl_ref: &Option<TraitRef>, f: impl FnOnce(&mut Self)) {
         let old = self.lctx.is_in_trait_impl;
-        self.lctx.is_in_trait_impl = if let &None = impl_ref { false } else { true };
+        self.lctx.is_in_trait_impl = impl_ref.is_some();
         f(self);
         self.lctx.is_in_trait_impl = old;
     }

compiler/rustc_codegen_ssa/src/lib.rs

@@ -8,8 +8,6 @@
 #![feature(or_patterns)]
 #![feature(trusted_len)]
 #![feature(associated_type_bounds)]
-#![feature(const_fn)] // for rustc_index::newtype_index
-#![feature(const_panic)] // for rustc_index::newtype_index
 #![recursion_limit = "256"]
 
 //! This crate contains codegen code that is used by all codegen backends (LLVM and others).

compiler/rustc_data_structures/src/lib.rs

@@ -11,7 +11,6 @@
 #![feature(control_flow_enum)]
 #![feature(in_band_lifetimes)]
 #![feature(unboxed_closures)]
-#![feature(generators)]
 #![feature(generator_trait)]
 #![feature(fn_traits)]
 #![feature(int_bits_const)]
@@ -27,7 +26,7 @@
 #![feature(thread_id_value)]
 #![feature(extend_one)]
 #![feature(const_panic)]
-#![feature(const_generics)]
+#![feature(min_const_generics)]
 #![feature(once_cell)]
 #![allow(rustc::default_hash_types)]
 

compiler/rustc_expand/src/lib.rs

@@ -1,5 +1,4 @@
 #![feature(bool_to_option)]
-#![feature(cow_is_borrowed)]
 #![feature(crate_visibility_modifier)]
 #![feature(decl_macro)]
 #![feature(or_patterns)]

compiler/rustc_infer/src/lib.rs

@@ -13,7 +13,6 @@
 //! This API is completely unstable and subject to change.
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/")]
-#![feature(bindings_after_at)]
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
@@ -23,7 +22,6 @@
 #![feature(never_type)]
 #![feature(or_patterns)]
 #![feature(in_band_lifetimes)]
-#![feature(crate_visibility_modifier)]
 #![recursion_limit = "512"] // For rustdoc
 
 #[macro_use]

compiler/rustc_middle/src/lib.rs

@@ -30,26 +30,21 @@
 #![feature(cmp_min_max_by)]
 #![feature(const_fn)]
 #![feature(const_panic)]
-#![feature(const_fn_transmute)]
 #![feature(core_intrinsics)]
 #![feature(discriminant_kind)]
-#![feature(drain_filter)]
 #![feature(never_type)]
-#![feature(exhaustive_patterns)]
 #![feature(extern_types)]
 #![feature(nll)]
 #![feature(once_cell)]
 #![feature(option_expect_none)]
 #![feature(or_patterns)]
 #![feature(min_specialization)]
 #![feature(trusted_len)]
-#![feature(stmt_expr_attributes)]
 #![feature(test)]
 #![feature(in_band_lifetimes)]
 #![feature(crate_visibility_modifier)]
 #![feature(associated_type_bounds)]
 #![feature(rustc_attrs)]
-#![feature(hash_raw_entry)]
 #![feature(int_error_matching)]
 #![recursion_limit = "512"]
 

compiler/rustc_middle/src/mir/mod.rs

@@ -1280,49 +1280,49 @@ impl<O> AssertKind<O> {
         match self {
             BoundsCheck { ref len, ref index } => write!(
                 f,
-                "\"index out of bounds: the len is {{}} but the index is {{}}\", {:?}, {:?}",
+                "\"index out of bounds: the length is {{}} but the index is {{}}\", {:?}, {:?}",
                 len, index
             ),
 
             OverflowNeg(op) => {
-                write!(f, "\"attempt to negate {{}} which would overflow\", {:?}", op)
+                write!(f, "\"attempt to negate `{{}}`, which would overflow\", {:?}", op)
             }
-            DivisionByZero(op) => write!(f, "\"attempt to divide {{}} by zero\", {:?}", op),
+            DivisionByZero(op) => write!(f, "\"attempt to divide `{{}}` by zero\", {:?}", op),
             RemainderByZero(op) => write!(
                 f,
-                "\"attempt to calculate the remainder of {{}} with a divisor of zero\", {:?}",
+                "\"attempt to calculate the remainder of `{{}}` with a divisor of zero\", {:?}",
                 op
             ),
             Overflow(BinOp::Add, l, r) => write!(
                 f,
-                "\"attempt to compute `{{}} + {{}}` which would overflow\", {:?}, {:?}",
+                "\"attempt to compute `{{}} + {{}}`, which would overflow\", {:?}, {:?}",
                 l, r
             ),
             Overflow(BinOp::Sub, l, r) => write!(
                 f,
-                "\"attempt to compute `{{}} - {{}}` which would overflow\", {:?}, {:?}",
+                "\"attempt to compute `{{}} - {{}}`, which would overflow\", {:?}, {:?}",
                 l, r
             ),
             Overflow(BinOp::Mul, l, r) => write!(
                 f,
-                "\"attempt to compute `{{}} * {{}}` which would overflow\", {:?}, {:?}",
+                "\"attempt to compute `{{}} * {{}}`, which would overflow\", {:?}, {:?}",
                 l, r
             ),
             Overflow(BinOp::Div, l, r) => write!(
                 f,
-                "\"attempt to compute `{{}} / {{}}` which would overflow\", {:?}, {:?}",
+                "\"attempt to compute `{{}} / {{}}`, which would overflow\", {:?}, {:?}",
                 l, r
             ),
             Overflow(BinOp::Rem, l, r) => write!(
                 f,
-                "\"attempt to compute the remainder of `{{}} % {{}}` which would overflow\", {:?}, {:?}",
+                "\"attempt to compute the remainder of `{{}} % {{}}`, which would overflow\", {:?}, {:?}",
                 l, r
             ),
             Overflow(BinOp::Shr, _, r) => {
-                write!(f, "\"attempt to shift right by {{}} which would overflow\", {:?}", r)
+                write!(f, "\"attempt to shift right by `{{}}`, which would overflow\", {:?}", r)
             }
             Overflow(BinOp::Shl, _, r) => {
-                write!(f, "\"attempt to shift left by {{}} which would overflow\", {:?}", r)
+                write!(f, "\"attempt to shift left by `{{}}`, which would overflow\", {:?}", r)
             }
             _ => write!(f, "\"{}\"", self.description()),
         }
@@ -1333,36 +1333,40 @@ impl<O: fmt::Debug> fmt::Debug for AssertKind<O> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         use AssertKind::*;
         match self {
-            BoundsCheck { ref len, ref index } => {
-                write!(f, "index out of bounds: the len is {:?} but the index is {:?}", len, index)
-            }
-            OverflowNeg(op) => write!(f, "attempt to negate {:#?} which would overflow", op),
-            DivisionByZero(op) => write!(f, "attempt to divide {:#?} by zero", op),
-            RemainderByZero(op) => {
-                write!(f, "attempt to calculate the remainder of {:#?} with a divisor of zero", op)
-            }
+            BoundsCheck { ref len, ref index } => write!(
+                f,
+                "index out of bounds: the length is {:?} but the index is {:?}",
+                len, index
+            ),
+            OverflowNeg(op) => write!(f, "attempt to negate `{:#?}`, which would overflow", op),
+            DivisionByZero(op) => write!(f, "attempt to divide `{:#?}` by zero", op),
+            RemainderByZero(op) => write!(
+                f,
+                "attempt to calculate the remainder of `{:#?}` with a divisor of zero",
+                op
+            ),
             Overflow(BinOp::Add, l, r) => {
-                write!(f, "attempt to compute `{:#?} + {:#?}` which would overflow", l, r)
+                write!(f, "attempt to compute `{:#?} + {:#?}`, which would overflow", l, r)
             }
             Overflow(BinOp::Sub, l, r) => {
-                write!(f, "attempt to compute `{:#?} - {:#?}` which would overflow", l, r)
+                write!(f, "attempt to compute `{:#?} - {:#?}`, which would overflow", l, r)
             }
             Overflow(BinOp::Mul, l, r) => {
-                write!(f, "attempt to compute `{:#?} * {:#?}` which would overflow", l, r)
+                write!(f, "attempt to compute `{:#?} * {:#?}`, which would overflow", l, r)
             }
             Overflow(BinOp::Div, l, r) => {
-                write!(f, "attempt to compute `{:#?} / {:#?}` which would overflow", l, r)
+                write!(f, "attempt to compute `{:#?} / {:#?}`, which would overflow", l, r)
             }
             Overflow(BinOp::Rem, l, r) => write!(
                 f,
-                "attempt to compute the remainder of `{:#?} % {:#?}` which would overflow",
+                "attempt to compute the remainder of `{:#?} % {:#?}`, which would overflow",
                 l, r
             ),
             Overflow(BinOp::Shr, _, r) => {
-                write!(f, "attempt to shift right by {:#?} which would overflow", r)
+                write!(f, "attempt to shift right by `{:#?}`, which would overflow", r)
             }
             Overflow(BinOp::Shl, _, r) => {
-                write!(f, "attempt to shift left by {:#?} which would overflow", r)
+                write!(f, "attempt to shift left by `{:#?}`, which would overflow", r)
             }
             _ => write!(f, "{}", self.description()),
         }
@@ -2286,7 +2290,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
 /// Constants
 ///
 /// Two constants are equal if they are the same constant. Note that
-/// this does not necessarily mean that they are `==` in Rust -- in
+/// this does not necessarily mean that they are `==` in Rust. In
 /// particular, one must be wary of `NaN`!
 
 #[derive(Clone, Copy, PartialEq, TyEncodable, TyDecodable, HashStable)]

compiler/rustc_middle/src/ty/instance.rs

@@ -62,10 +62,6 @@ pub enum InstanceDef<'tcx> {
     /// `<fn() as FnTrait>::call_*` (generated `FnTrait` implementation for `fn()` pointers).
     ///
     /// `DefId` is `FnTrait::call_*`.
-    ///
-    /// NB: the (`fn` pointer) type must currently be monomorphic to avoid double substitution
-    /// problems with the MIR shim bodies. `Instance::resolve` enforces this.
-    // FIXME(#69925) support polymorphic MIR shim bodies properly instead.
     FnPtrShim(DefId, Ty<'tcx>),
 
     /// Dynamic dispatch to `<dyn Trait as Trait>::fn`.
@@ -87,10 +83,6 @@ pub enum InstanceDef<'tcx> {
     /// The `DefId` is for `core::ptr::drop_in_place`.
     /// The `Option<Ty<'tcx>>` is either `Some(T)`, or `None` for empty drop
     /// glue.
-    ///
-    /// NB: the type must currently be monomorphic to avoid double substitution
-    /// problems with the MIR shim bodies. `Instance::resolve` enforces this.
-    // FIXME(#69925) support polymorphic MIR shim bodies properly instead.
     DropGlue(DefId, Option<Ty<'tcx>>),
 
     /// Compiler-generated `<T as Clone>::clone` implementation.
@@ -99,10 +91,6 @@ pub enum InstanceDef<'tcx> {
     /// Additionally, arrays, tuples, and closures get a `Clone` shim even if they aren't `Copy`.
     ///
     /// The `DefId` is for `Clone::clone`, the `Ty` is the type `T` with the builtin `Clone` impl.
-    ///
-    /// NB: the type must currently be monomorphic to avoid double substitution
-    /// problems with the MIR shim bodies. `Instance::resolve` enforces this.
-    // FIXME(#69925) support polymorphic MIR shim bodies properly instead.
     CloneShim(DefId, Ty<'tcx>),
 }
 
@@ -243,6 +231,27 @@ impl<'tcx> InstanceDef<'tcx> {
             _ => false,
         }
     }
+
+    /// Returns `true` when the MIR body associated with this instance should be monomorphized
+    /// by its users (e.g. codegen or miri) by substituting the `substs` from `Instance` (see
+    /// `Instance::substs_for_mir_body`).
+    ///
+    /// Otherwise, returns `false` only for some kinds of shims where the construction of the MIR
+    /// body should perform necessary substitutions.
+    pub fn has_polymorphic_mir_body(&self) -> bool {
+        match *self {
+            InstanceDef::CloneShim(..)
+            | InstanceDef::FnPtrShim(..)
+            | InstanceDef::DropGlue(_, Some(_)) => false,
+            InstanceDef::ClosureOnceShim { .. }
+            | InstanceDef::DropGlue(..)
+            | InstanceDef::Item(_)
+            | InstanceDef::Intrinsic(..)
+            | InstanceDef::ReifyShim(..)
+            | InstanceDef::Virtual(..)
+            | InstanceDef::VtableShim(..) => true,
+        }
+    }
 }
 
 impl<'tcx> fmt::Display for Instance<'tcx> {
@@ -440,30 +449,18 @@ impl<'tcx> Instance<'tcx> {
         Instance { def, substs }
     }
 
-    /// FIXME(#69925) Depending on the kind of `InstanceDef`, the MIR body associated with an
+    /// Depending on the kind of `InstanceDef`, the MIR body associated with an
     /// instance is expressed in terms of the generic parameters of `self.def_id()`, and in other
     /// cases the MIR body is expressed in terms of the types found in the substitution array.
     /// In the former case, we want to substitute those generic types and replace them with the
     /// values from the substs when monomorphizing the function body. But in the latter case, we
     /// don't want to do that substitution, since it has already been done effectively.
     ///
-    /// This function returns `Some(substs)` in the former case and None otherwise -- i.e., if
+    /// This function returns `Some(substs)` in the former case and `None` otherwise -- i.e., if
     /// this function returns `None`, then the MIR body does not require substitution during
-    /// monomorphization.
+    /// codegen.
     pub fn substs_for_mir_body(&self) -> Option<SubstsRef<'tcx>> {
-        match self.def {
-            InstanceDef::CloneShim(..)
-            | InstanceDef::DropGlue(_, Some(_)) => None,
-            InstanceDef::ClosureOnceShim { .. }
-            | InstanceDef::DropGlue(..)
-            // FIXME(#69925): `FnPtrShim` should be in the other branch.
-            | InstanceDef::FnPtrShim(..)
-            | InstanceDef::Item(_)
-            | InstanceDef::Intrinsic(..)
-            | InstanceDef::ReifyShim(..)
-            | InstanceDef::Virtual(..)
-            | InstanceDef::VtableShim(..) => Some(self.substs),
-        }
+        if self.def.has_polymorphic_mir_body() { Some(self.substs) } else { None }
     }
 
     /// Returns a new `Instance` where generic parameters in `instance.substs` are replaced by

compiler/rustc_mir/src/dataflow/framework/graphviz.rs

@@ -1,6 +1,7 @@
 //! A helpful diagram for debugging dataflow problems.
 
 use std::borrow::Cow;
+use std::lazy::SyncOnceCell;
 use std::{io, ops, str};
 
 use regex::Regex;
@@ -570,6 +571,13 @@ where
     }
 }
 
+macro_rules! regex {
+    ($re:literal $(,)?) => {{
+        static RE: SyncOnceCell<regex::Regex> = SyncOnceCell::new();
+        RE.get_or_init(|| Regex::new($re).unwrap())
+    }};
+}
+
 fn diff_pretty<T, C>(new: T, old: T, ctxt: &C) -> String
 where
     T: DebugWithContext<C>,
@@ -578,7 +586,7 @@ where
         return String::new();
     }
 
-    let re = Regex::new("\t?\u{001f}([+-])").unwrap();
+    let re = regex!("\t?\u{001f}([+-])");
 
     let raw_diff = format!("{:#?}", DebugDiffWithAdapter { new, old, ctxt });
 

compiler/rustc_mir/src/dataflow/impls/mod.rs

@@ -204,7 +204,7 @@ impl<'a, 'tcx> HasMoveData<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
 
 /// `EverInitializedPlaces` tracks all places that might have ever been
 /// initialized upon reaching a particular point in the control flow
-/// for a function, without an intervening `Storage Dead`.
+/// for a function, without an intervening `StorageDead`.
 ///
 /// This dataflow is used to determine if an immutable local variable may
 /// be assigned to.