Rollup merge of #69981 - oli-obk:const_blocks, r=eddyb

Evaluate repeat expression lengths as late as possible

Fixes #68567

r? @varkor

Author: Centril

src/librustc/mir/interpret/mod.rs

@@ -156,7 +156,7 @@ pub struct LitToConstInput<'tcx> {
 pub enum LitToConstError {
     /// The literal's inferred type did not match the expected `ty` in the input.
     /// This is used for graceful error handling (`delay_span_bug`) in
-    /// type checking (`AstConv::ast_const_to_const`).
+    /// type checking (`Const::from_anon_const`).
     TypeError,
     UnparseableFloat,
     Reported,

src/librustc/mir/mod.rs

@@ -45,6 +45,7 @@ pub mod mono;
 mod query;
 pub mod tcx;
 pub mod traversal;
+mod type_foldable;
 pub mod visit;
 
 /// Types for locals
@@ -2046,7 +2047,7 @@ pub enum Rvalue<'tcx> {
     Use(Operand<'tcx>),
 
     /// [x; 32]
-    Repeat(Operand<'tcx>, u64),
+    Repeat(Operand<'tcx>, &'tcx ty::Const<'tcx>),
 
     /// &x or &mut x
     Ref(Region<'tcx>, BorrowKind, Place<'tcx>),
@@ -2174,7 +2175,11 @@ impl<'tcx> Debug for Rvalue<'tcx> {
 
         match *self {
             Use(ref place) => write!(fmt, "{:?}", place),
-            Repeat(ref a, ref b) => write!(fmt, "[{:?}; {:?}]", a, b),
+            Repeat(ref a, ref b) => {
+                write!(fmt, "[{:?}; ", a)?;
+                pretty_print_const(b, fmt, false)?;
+                write!(fmt, "]")
+            }
             Len(ref a) => write!(fmt, "Len({:?})", a),
             Cast(ref kind, ref place, ref ty) => {
                 write!(fmt, "{:?} as {:?} ({:?})", place, ty, kind)
@@ -2542,18 +2547,26 @@ impl<'tcx> Debug for Constant<'tcx> {
 
 impl<'tcx> Display for Constant<'tcx> {
     fn fmt(&self, fmt: &mut Formatter<'_>) -> fmt::Result {
-        use crate::ty::print::PrettyPrinter;
         write!(fmt, "const ")?;
-        ty::tls::with(|tcx| {
-            let literal = tcx.lift(&self.literal).unwrap();
-            let mut cx = FmtPrinter::new(tcx, fmt, Namespace::ValueNS);
-            cx.print_alloc_ids = true;
-            cx.pretty_print_const(literal, true)?;
-            Ok(())
-        })
+        pretty_print_const(self.literal, fmt, true)
     }
 }
 
+fn pretty_print_const(
+    c: &ty::Const<'tcx>,
+    fmt: &mut Formatter<'_>,
+    print_types: bool,
+) -> fmt::Result {
+    use crate::ty::print::PrettyPrinter;
+    ty::tls::with(|tcx| {
+        let literal = tcx.lift(&c).unwrap();
+        let mut cx = FmtPrinter::new(tcx, fmt, Namespace::ValueNS);
+        cx.print_alloc_ids = true;
+        cx.pretty_print_const(literal, print_types)?;
+        Ok(())
+    })
+}
+
 impl<'tcx> graph::DirectedGraph for Body<'tcx> {
     type Node = BasicBlock;
 }
@@ -2651,325 +2664,3 @@ impl Location {
         }
     }
 }
-
-/*
- * `TypeFoldable` implementations for MIR types
-*/
-
-CloneTypeFoldableAndLiftImpls! {
-    BlockTailInfo,
-    MirPhase,
-    SourceInfo,
-    FakeReadCause,
-    RetagKind,
-    SourceScope,
-    SourceScopeData,
-    SourceScopeLocalData,
-    UserTypeAnnotationIndex,
-}
-
-impl<'tcx> TypeFoldable<'tcx> for Terminator<'tcx> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        use crate::mir::TerminatorKind::*;
-
-        let kind = match self.kind {
-            Goto { target } => Goto { target },
-            SwitchInt { ref discr, switch_ty, ref values, ref targets } => SwitchInt {
-                discr: discr.fold_with(folder),
-                switch_ty: switch_ty.fold_with(folder),
-                values: values.clone(),
-                targets: targets.clone(),
-            },
-            Drop { ref location, target, unwind } => {
-                Drop { location: location.fold_with(folder), target, unwind }
-            }
-            DropAndReplace { ref location, ref value, target, unwind } => DropAndReplace {
-                location: location.fold_with(folder),
-                value: value.fold_with(folder),
-                target,
-                unwind,
-            },
-            Yield { ref value, resume, ref resume_arg, drop } => Yield {
-                value: value.fold_with(folder),
-                resume,
-                resume_arg: resume_arg.fold_with(folder),
-                drop,
-            },
-            Call { ref func, ref args, ref destination, cleanup, from_hir_call } => {
-                let dest =
-                    destination.as_ref().map(|&(ref loc, dest)| (loc.fold_with(folder), dest));
-
-                Call {
-                    func: func.fold_with(folder),
-                    args: args.fold_with(folder),
-                    destination: dest,
-                    cleanup,
-                    from_hir_call,
-                }
-            }
-            Assert { ref cond, expected, ref msg, target, cleanup } => {
-                use AssertKind::*;
-                let msg = match msg {
-                    BoundsCheck { ref len, ref index } => {
-                        BoundsCheck { len: len.fold_with(folder), index: index.fold_with(folder) }
-                    }
-                    Overflow(_)
-                    | OverflowNeg
-                    | DivisionByZero
-                    | RemainderByZero
-                    | ResumedAfterReturn(_)
-                    | ResumedAfterPanic(_) => msg.clone(),
-                };
-                Assert { cond: cond.fold_with(folder), expected, msg, target, cleanup }
-            }
-            GeneratorDrop => GeneratorDrop,
-            Resume => Resume,
-            Abort => Abort,
-            Return => Return,
-            Unreachable => Unreachable,
-            FalseEdges { real_target, imaginary_target } => {
-                FalseEdges { real_target, imaginary_target }
-            }
-            FalseUnwind { real_target, unwind } => FalseUnwind { real_target, unwind },
-        };
-        Terminator { source_info: self.source_info, kind }
-    }
-
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        use crate::mir::TerminatorKind::*;
-
-        match self.kind {
-            SwitchInt { ref discr, switch_ty, .. } => {
-                discr.visit_with(visitor) || switch_ty.visit_with(visitor)
-            }
-            Drop { ref location, .. } => location.visit_with(visitor),
-            DropAndReplace { ref location, ref value, .. } => {
-                location.visit_with(visitor) || value.visit_with(visitor)
-            }
-            Yield { ref value, .. } => value.visit_with(visitor),
-            Call { ref func, ref args, ref destination, .. } => {
-                let dest = if let Some((ref loc, _)) = *destination {
-                    loc.visit_with(visitor)
-                } else {
-                    false
-                };
-                dest || func.visit_with(visitor) || args.visit_with(visitor)
-            }
-            Assert { ref cond, ref msg, .. } => {
-                if cond.visit_with(visitor) {
-                    use AssertKind::*;
-                    match msg {
-                        BoundsCheck { ref len, ref index } => {
-                            len.visit_with(visitor) || index.visit_with(visitor)
-                        }
-                        Overflow(_)
-                        | OverflowNeg
-                        | DivisionByZero
-                        | RemainderByZero
-                        | ResumedAfterReturn(_)
-                        | ResumedAfterPanic(_) => false,
-                    }
-                } else {
-                    false
-                }
-            }
-            Goto { .. }
-            | Resume
-            | Abort
-            | Return
-            | GeneratorDrop
-            | Unreachable
-            | FalseEdges { .. }
-            | FalseUnwind { .. } => false,
-        }
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for GeneratorKind {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self {
-        *self
-    }
-
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool {
-        false
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for Place<'tcx> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        Place { local: self.local.fold_with(folder), projection: self.projection.fold_with(folder) }
-    }
-
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        self.local.visit_with(visitor) || self.projection.visit_with(visitor)
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for &'tcx ty::List<PlaceElem<'tcx>> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        let v = self.iter().map(|t| t.fold_with(folder)).collect::<Vec<_>>();
-        folder.tcx().intern_place_elems(&v)
-    }
-
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        self.iter().any(|t| t.visit_with(visitor))
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        use crate::mir::Rvalue::*;
-        match *self {
-            Use(ref op) => Use(op.fold_with(folder)),
-            Repeat(ref op, len) => Repeat(op.fold_with(folder), len),
-            Ref(region, bk, ref place) => {
-                Ref(region.fold_with(folder), bk, place.fold_with(folder))
-            }
-            AddressOf(mutability, ref place) => AddressOf(mutability, place.fold_with(folder)),
-            Len(ref place) => Len(place.fold_with(folder)),
-            Cast(kind, ref op, ty) => Cast(kind, op.fold_with(folder), ty.fold_with(folder)),
-            BinaryOp(op, ref rhs, ref lhs) => {
-                BinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder))
-            }
-            CheckedBinaryOp(op, ref rhs, ref lhs) => {
-                CheckedBinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder))
-            }
-            UnaryOp(op, ref val) => UnaryOp(op, val.fold_with(folder)),
-            Discriminant(ref place) => Discriminant(place.fold_with(folder)),
-            NullaryOp(op, ty) => NullaryOp(op, ty.fold_with(folder)),
-            Aggregate(ref kind, ref fields) => {
-                let kind = box match **kind {
-                    AggregateKind::Array(ty) => AggregateKind::Array(ty.fold_with(folder)),
-                    AggregateKind::Tuple => AggregateKind::Tuple,
-                    AggregateKind::Adt(def, v, substs, user_ty, n) => AggregateKind::Adt(
-                        def,
-                        v,
-                        substs.fold_with(folder),
-                        user_ty.fold_with(folder),
-                        n,
-                    ),
-                    AggregateKind::Closure(id, substs) => {
-                        AggregateKind::Closure(id, substs.fold_with(folder))
-                    }
-                    AggregateKind::Generator(id, substs, movablity) => {
-                        AggregateKind::Generator(id, substs.fold_with(folder), movablity)
-                    }
-                };
-                Aggregate(kind, fields.fold_with(folder))
-            }
-        }
-    }
-
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        use crate::mir::Rvalue::*;
-        match *self {
-            Use(ref op) => op.visit_with(visitor),
-            Repeat(ref op, _) => op.visit_with(visitor),
-            Ref(region, _, ref place) => region.visit_with(visitor) || place.visit_with(visitor),
-            AddressOf(_, ref place) => place.visit_with(visitor),
-            Len(ref place) => place.visit_with(visitor),
-            Cast(_, ref op, ty) => op.visit_with(visitor) || ty.visit_with(visitor),
-            BinaryOp(_, ref rhs, ref lhs) | CheckedBinaryOp(_, ref rhs, ref lhs) => {
-                rhs.visit_with(visitor) || lhs.visit_with(visitor)
-            }
-            UnaryOp(_, ref val) => val.visit_with(visitor),
-            Discriminant(ref place) => place.visit_with(visitor),
-            NullaryOp(_, ty) => ty.visit_with(visitor),
-            Aggregate(ref kind, ref fields) => {
-                (match **kind {
-                    AggregateKind::Array(ty) => ty.visit_with(visitor),
-                    AggregateKind::Tuple => false,
-                    AggregateKind::Adt(_, _, substs, user_ty, _) => {
-                        substs.visit_with(visitor) || user_ty.visit_with(visitor)
-                    }
-                    AggregateKind::Closure(_, substs) => substs.visit_with(visitor),
-                    AggregateKind::Generator(_, substs, _) => substs.visit_with(visitor),
-                }) || fields.visit_with(visitor)
-            }
-        }
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for Operand<'tcx> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        match *self {
-            Operand::Copy(ref place) => Operand::Copy(place.fold_with(folder)),
-            Operand::Move(ref place) => Operand::Move(place.fold_with(folder)),
-            Operand::Constant(ref c) => Operand::Constant(c.fold_with(folder)),
-        }
-    }
-
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        match *self {
-            Operand::Copy(ref place) | Operand::Move(ref place) => place.visit_with(visitor),
-            Operand::Constant(ref c) => c.visit_with(visitor),
-        }
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for PlaceElem<'tcx> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        use crate::mir::ProjectionElem::*;
-
-        match *self {
-            Deref => Deref,
-            Field(f, ty) => Field(f, ty.fold_with(folder)),
-            Index(v) => Index(v.fold_with(folder)),
-            Downcast(symbol, variantidx) => Downcast(symbol, variantidx),
-            ConstantIndex { offset, min_length, from_end } => {
-                ConstantIndex { offset, min_length, from_end }
-            }
-            Subslice { from, to, from_end } => Subslice { from, to, from_end },
-        }
-    }
-
-    fn super_visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> bool {
-        use crate::mir::ProjectionElem::*;
-
-        match self {
-            Field(_, ty) => ty.visit_with(visitor),
-            Index(v) => v.visit_with(visitor),
-            _ => false,
-        }
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for Field {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self {
-        *self
-    }
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool {
-        false
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for GeneratorSavedLocal {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self {
-        *self
-    }
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool {
-        false
-    }
-}
-
-impl<'tcx, R: Idx, C: Idx> TypeFoldable<'tcx> for BitMatrix<R, C> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, _: &mut F) -> Self {
-        self.clone()
-    }
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, _: &mut V) -> bool {
-        false
-    }
-}
-
-impl<'tcx> TypeFoldable<'tcx> for Constant<'tcx> {
-    fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
-        Constant {
-            span: self.span,
-            user_ty: self.user_ty.fold_with(folder),
-            literal: self.literal.fold_with(folder),
-        }
-    }
-    fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
-        self.literal.visit_with(visitor)
-    }
-}