Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 342 insertions, 0 deletions

diff --git a/compiler/rustc_middle/src/ty/flags.rs b/compiler/rustc_middle/src/ty/flags.rs
new file mode 100644
index 000000000..ea6bb8a7a
--- /dev/null
+++ b/compiler/rustc_middle/src/ty/flags.rs
@@ -0,0 +1,342 @@
+use crate::ty::subst::{GenericArg, GenericArgKind};
+use crate::ty::{self, InferConst, Term, Ty, TypeFlags};
+use std::slice;
+
+#[derive(Debug)]
+pub struct FlagComputation {
+    pub flags: TypeFlags,
+
+    // see `Ty::outer_exclusive_binder` for details
+    pub outer_exclusive_binder: ty::DebruijnIndex,
+}
+
+impl FlagComputation {
+    fn new() -> FlagComputation {
+        FlagComputation { flags: TypeFlags::empty(), outer_exclusive_binder: ty::INNERMOST }
+    }
+
+    #[allow(rustc::usage_of_ty_tykind)]
+    pub fn for_kind(kind: &ty::TyKind<'_>) -> FlagComputation {
+        let mut result = FlagComputation::new();
+        result.add_kind(kind);
+        result
+    }
+
+    pub fn for_predicate<'tcx>(binder: ty::Binder<'tcx, ty::PredicateKind<'_>>) -> FlagComputation {
+        let mut result = FlagComputation::new();
+        result.add_predicate(binder);
+        result
+    }
+
+    pub fn for_const(c: ty::Const<'_>) -> TypeFlags {
+        let mut result = FlagComputation::new();
+        result.add_const(c);
+        result.flags
+    }
+
+    pub fn for_unevaluated_const(uv: ty::Unevaluated<'_>) -> TypeFlags {
+        let mut result = FlagComputation::new();
+        result.add_unevaluated_const(uv);
+        result.flags
+    }
+
+    fn add_flags(&mut self, flags: TypeFlags) {
+        self.flags = self.flags | flags;
+    }
+
+    /// indicates that `self` refers to something at binding level `binder`
+    fn add_bound_var(&mut self, binder: ty::DebruijnIndex) {
+        let exclusive_binder = binder.shifted_in(1);
+        self.add_exclusive_binder(exclusive_binder);
+    }
+
+    /// indicates that `self` refers to something *inside* binding
+    /// level `binder` -- not bound by `binder`, but bound by the next
+    /// binder internal to it
+    fn add_exclusive_binder(&mut self, exclusive_binder: ty::DebruijnIndex) {
+        self.outer_exclusive_binder = self.outer_exclusive_binder.max(exclusive_binder);
+    }
+
+    /// Adds the flags/depth from a set of types that appear within the current type, but within a
+    /// region binder.
+    fn bound_computation<T, F>(&mut self, value: ty::Binder<'_, T>, f: F)
+    where
+        F: FnOnce(&mut Self, T),
+    {
+        let mut computation = FlagComputation::new();
+
+        if !value.bound_vars().is_empty() {
+            computation.flags = computation.flags | TypeFlags::HAS_RE_LATE_BOUND;
+        }
+
+        f(&mut computation, value.skip_binder());
+
+        self.add_flags(computation.flags);
+
+        // The types that contributed to `computation` occurred within
+        // a region binder, so subtract one from the region depth
+        // within when adding the depth to `self`.
+        let outer_exclusive_binder = computation.outer_exclusive_binder;
+        if outer_exclusive_binder > ty::INNERMOST {
+            self.add_exclusive_binder(outer_exclusive_binder.shifted_out(1));
+        } // otherwise, this binder captures nothing
+    }
+
+    #[allow(rustc::usage_of_ty_tykind)]
+    fn add_kind(&mut self, kind: &ty::TyKind<'_>) {
+        match kind {
+            &ty::Bool
+            | &ty::Char
+            | &ty::Int(_)
+            | &ty::Float(_)
+            | &ty::Uint(_)
+            | &ty::Never
+            | &ty::Str
+            | &ty::Foreign(..) => {}
+
+            &ty::Error(_) => self.add_flags(TypeFlags::HAS_ERROR),
+
+            &ty::Param(_) => {
+                self.add_flags(TypeFlags::HAS_TY_PARAM);
+                self.add_flags(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+            }
+
+            &ty::Generator(_, ref substs, _) => {
+                let substs = substs.as_generator();
+                let should_remove_further_specializable =
+                    !self.flags.contains(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+                self.add_substs(substs.parent_substs());
+                if should_remove_further_specializable {
+                    self.flags -= TypeFlags::STILL_FURTHER_SPECIALIZABLE;
+                }
+
+                self.add_ty(substs.resume_ty());
+                self.add_ty(substs.return_ty());
+                self.add_ty(substs.witness());
+                self.add_ty(substs.yield_ty());
+                self.add_ty(substs.tupled_upvars_ty());
+            }
+
+            &ty::GeneratorWitness(ts) => {
+                self.bound_computation(ts, |flags, ts| flags.add_tys(ts));
+            }
+
+            &ty::Closure(_, substs) => {
+                let substs = substs.as_closure();
+                let should_remove_further_specializable =
+                    !self.flags.contains(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+                self.add_substs(substs.parent_substs());
+                if should_remove_further_specializable {
+                    self.flags -= TypeFlags::STILL_FURTHER_SPECIALIZABLE;
+                }
+
+                self.add_ty(substs.sig_as_fn_ptr_ty());
+                self.add_ty(substs.kind_ty());
+                self.add_ty(substs.tupled_upvars_ty());
+            }
+
+            &ty::Bound(debruijn, _) => {
+                self.add_bound_var(debruijn);
+            }
+
+            &ty::Placeholder(..) => {
+                self.add_flags(TypeFlags::HAS_TY_PLACEHOLDER);
+                self.add_flags(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+            }
+
+            &ty::Infer(infer) => {
+                self.add_flags(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+                match infer {
+                    ty::FreshTy(_) | ty::FreshIntTy(_) | ty::FreshFloatTy(_) => {
+                        self.add_flags(TypeFlags::HAS_TY_FRESH)
+                    }
+
+                    ty::TyVar(_) | ty::IntVar(_) | ty::FloatVar(_) => {
+                        self.add_flags(TypeFlags::HAS_TY_INFER)
+                    }
+                }
+            }
+
+            &ty::Adt(_, substs) => {
+                self.add_substs(substs);
+            }
+
+            &ty::Projection(data) => {
+                self.add_flags(TypeFlags::HAS_TY_PROJECTION);
+                self.add_projection_ty(data);
+            }
+
+            &ty::Opaque(_, substs) => {
+                self.add_flags(TypeFlags::HAS_TY_OPAQUE);
+                self.add_substs(substs);
+            }
+
+            &ty::Dynamic(obj, r) => {
+                for predicate in obj.iter() {
+                    self.bound_computation(predicate, |computation, predicate| match predicate {
+                        ty::ExistentialPredicate::Trait(tr) => computation.add_substs(tr.substs),
+                        ty::ExistentialPredicate::Projection(p) => {
+                            computation.add_existential_projection(&p);
+                        }
+                        ty::ExistentialPredicate::AutoTrait(_) => {}
+                    });
+                }
+
+                self.add_region(r);
+            }
+
+            &ty::Array(tt, len) => {
+                self.add_ty(tt);
+                self.add_const(len);
+            }
+
+            &ty::Slice(tt) => self.add_ty(tt),
+
+            &ty::RawPtr(ref m) => {
+                self.add_ty(m.ty);
+            }
+
+            &ty::Ref(r, ty, _) => {
+                self.add_region(r);
+                self.add_ty(ty);
+            }
+
+            &ty::Tuple(types) => {
+                self.add_tys(types);
+            }
+
+            &ty::FnDef(_, substs) => {
+                self.add_substs(substs);
+            }
+
+            &ty::FnPtr(fn_sig) => self.bound_computation(fn_sig, |computation, fn_sig| {
+                computation.add_tys(fn_sig.inputs());
+                computation.add_ty(fn_sig.output());
+            }),
+        }
+    }
+
+    fn add_predicate(&mut self, binder: ty::Binder<'_, ty::PredicateKind<'_>>) {
+        self.bound_computation(binder, |computation, atom| computation.add_predicate_atom(atom));
+    }
+
+    fn add_predicate_atom(&mut self, atom: ty::PredicateKind<'_>) {
+        match atom {
+            ty::PredicateKind::Trait(trait_pred) => {
+                self.add_substs(trait_pred.trait_ref.substs);
+            }
+            ty::PredicateKind::RegionOutlives(ty::OutlivesPredicate(a, b)) => {
+                self.add_region(a);
+                self.add_region(b);
+            }
+            ty::PredicateKind::TypeOutlives(ty::OutlivesPredicate(ty, region)) => {
+                self.add_ty(ty);
+                self.add_region(region);
+            }
+            ty::PredicateKind::Subtype(ty::SubtypePredicate { a_is_expected: _, a, b }) => {
+                self.add_ty(a);
+                self.add_ty(b);
+            }
+            ty::PredicateKind::Coerce(ty::CoercePredicate { a, b }) => {
+                self.add_ty(a);
+                self.add_ty(b);
+            }
+            ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
+                self.add_projection_ty(projection_ty);
+                match term {
+                    Term::Ty(ty) => self.add_ty(ty),
+                    Term::Const(c) => self.add_const(c),
+                }
+            }
+            ty::PredicateKind::WellFormed(arg) => {
+                self.add_substs(slice::from_ref(&arg));
+            }
+            ty::PredicateKind::ObjectSafe(_def_id) => {}
+            ty::PredicateKind::ClosureKind(_def_id, substs, _kind) => {
+                self.add_substs(substs);
+            }
+            ty::PredicateKind::ConstEvaluatable(uv) => {
+                self.add_unevaluated_const(uv);
+            }
+            ty::PredicateKind::ConstEquate(expected, found) => {
+                self.add_const(expected);
+                self.add_const(found);
+            }
+            ty::PredicateKind::TypeWellFormedFromEnv(ty) => {
+                self.add_ty(ty);
+            }
+        }
+    }
+
+    fn add_ty(&mut self, ty: Ty<'_>) {
+        self.add_flags(ty.flags());
+        self.add_exclusive_binder(ty.outer_exclusive_binder());
+    }
+
+    fn add_tys(&mut self, tys: &[Ty<'_>]) {
+        for &ty in tys {
+            self.add_ty(ty);
+        }
+    }
+
+    fn add_region(&mut self, r: ty::Region<'_>) {
+        self.add_flags(r.type_flags());
+        if let ty::ReLateBound(debruijn, _) = *r {
+            self.add_bound_var(debruijn);
+        }
+    }
+
+    fn add_const(&mut self, c: ty::Const<'_>) {
+        self.add_ty(c.ty());
+        match c.kind() {
+            ty::ConstKind::Unevaluated(unevaluated) => self.add_unevaluated_const(unevaluated),
+            ty::ConstKind::Infer(infer) => {
+                self.add_flags(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+                match infer {
+                    InferConst::Fresh(_) => self.add_flags(TypeFlags::HAS_CT_FRESH),
+                    InferConst::Var(_) => self.add_flags(TypeFlags::HAS_CT_INFER),
+                }
+            }
+            ty::ConstKind::Bound(debruijn, _) => {
+                self.add_bound_var(debruijn);
+            }
+            ty::ConstKind::Param(_) => {
+                self.add_flags(TypeFlags::HAS_CT_PARAM);
+                self.add_flags(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+            }
+            ty::ConstKind::Placeholder(_) => {
+                self.add_flags(TypeFlags::HAS_CT_PLACEHOLDER);
+                self.add_flags(TypeFlags::STILL_FURTHER_SPECIALIZABLE);
+            }
+            ty::ConstKind::Value(_) => {}
+            ty::ConstKind::Error(_) => self.add_flags(TypeFlags::HAS_ERROR),
+        }
+    }
+
+    fn add_unevaluated_const<P>(&mut self, ct: ty::Unevaluated<'_, P>) {
+        self.add_substs(ct.substs);
+        self.add_flags(TypeFlags::HAS_CT_PROJECTION);
+    }
+
+    fn add_existential_projection(&mut self, projection: &ty::ExistentialProjection<'_>) {
+        self.add_substs(projection.substs);
+        match projection.term {
+            ty::Term::Ty(ty) => self.add_ty(ty),
+            ty::Term::Const(ct) => self.add_const(ct),
+        }
+    }
+
+    fn add_projection_ty(&mut self, projection_ty: ty::ProjectionTy<'_>) {
+        self.add_substs(projection_ty.substs);
+    }
+
+    fn add_substs(&mut self, substs: &[GenericArg<'_>]) {
+        for kind in substs {
+            match kind.unpack() {
+                GenericArgKind::Type(ty) => self.add_ty(ty),
+                GenericArgKind::Lifetime(lt) => self.add_region(lt),
+                GenericArgKind::Const(ct) => self.add_const(ct),
+            }
+        }
+    }
+}