From bcfd15b09c4f30ea1451440b65359902d702b3e5 Mon Sep 17 00:00:00 2001
From: Jonas Schievink <jonasschievink@gmail.com>
Date: Fri, 4 Sep 2020 22:24:03 +0200
Subject: [PATCH] Remove unused duplicated `trivial_dropck_outlives`
---
compiler/rustc_middle/src/traits/query.rs | 68 -----------------------
1 file changed, 68 deletions(-)
diff --git a/compiler/rustc_middle/src/traits/query.rs b/compiler/rustc_middle/src/traits/query.rs
index ffa6e6f5324..f9cadb3bb2d 100644
--- a/compiler/rustc_middle/src/traits/query.rs
+++ b/compiler/rustc_middle/src/traits/query.rs
@@ -190,74 +190,6 @@ impl<'tcx> FromIterator<DtorckConstraint<'tcx>> for DtorckConstraint<'tcx> {
}
}
-/// This returns true if the type `ty` is "trivial" for
-/// dropck-outlives -- that is, if it doesn't require any types to
-/// outlive. This is similar but not *quite* the same as the
-/// `needs_drop` test in the compiler already -- that is, for every
-/// type T for which this function return true, needs-drop would
-/// return `false`. But the reverse does not hold: in particular,
-/// `needs_drop` returns false for `PhantomData`, but it is not
-/// trivial for dropck-outlives.
-///
-/// Note also that `needs_drop` requires a "global" type (i.e., one
-/// with erased regions), but this function does not.
-pub fn trivial_dropck_outlives<'tcx>(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> bool {
- match ty.kind() {
- // None of these types have a destructor and hence they do not
- // require anything in particular to outlive the dtor's
- // execution.
- ty::Infer(ty::FreshIntTy(_))
- | ty::Infer(ty::FreshFloatTy(_))
- | ty::Bool
- | ty::Int(_)
- | ty::Uint(_)
- | ty::Float(_)
- | ty::Never
- | ty::FnDef(..)
- | ty::FnPtr(_)
- | ty::Char
- | ty::GeneratorWitness(..)
- | ty::RawPtr(_)
- | ty::Ref(..)
- | ty::Str
- | ty::Foreign(..)
- | ty::Error(_) => true,
-
- // [T; N] and [T] have same properties as T.
- ty::Array(ty, _) | ty::Slice(ty) => trivial_dropck_outlives(tcx, ty),
-
- // (T1..Tn) and closures have same properties as T1..Tn --
- // check if *any* of those are trivial.
- ty::Tuple(ref tys) => tys.iter().all(|t| trivial_dropck_outlives(tcx, t.expect_ty())),
- ty::Closure(_, ref substs) => {
- substs.as_closure().upvar_tys().all(|t| trivial_dropck_outlives(tcx, t))
- }
-
- ty::Adt(def, _) => {
- if Some(def.did) == tcx.lang_items().manually_drop() {
- // `ManuallyDrop` never has a dtor.
- true
- } else {
- // Other types might. Moreover, PhantomData doesn't
- // have a dtor, but it is considered to own its
- // content, so it is non-trivial. Unions can have `impl Drop`,
- // and hence are non-trivial as well.
- false
- }
- }
-
- // The following *might* require a destructor: needs deeper inspection.
- ty::Dynamic(..)
- | ty::Projection(..)
- | ty::Param(_)
- | ty::Opaque(..)
- | ty::Placeholder(..)
- | ty::Infer(_)
- | ty::Bound(..)
- | ty::Generator(..) => false,
- }
-}
-
#[derive(Debug, HashStable)]
pub struct CandidateStep<'tcx> {
pub self_ty: Canonical<'tcx, QueryResponse<'tcx, Ty<'tcx>>>,