Remove mir::StatementKind::EndRegion

Since lexical MIR borrow check is gone, and validation no longer uses
these, they can be removed.

Author: matthewjasper

src/librustc/ich/impls_mir.rs

@@ -217,9 +217,6 @@ for mir::StatementKind<'gcx> {
             mir::StatementKind::StorageDead(ref place) => {
                 place.hash_stable(hcx, hasher);
             }
-            mir::StatementKind::EndRegion(ref region_scope) => {
-                region_scope.hash_stable(hcx, hasher);
-            }
             mir::StatementKind::EscapeToRaw(ref place) => {
                 place.hash_stable(hcx, hasher);
             }

src/librustc/mir/mod.rs

@@ -15,7 +15,6 @@
 use hir::def::CtorKind;
 use hir::def_id::DefId;
 use hir::{self, HirId, InlineAsm};
-use middle::region;
 use mir::interpret::{ConstValue, EvalErrorKind, Scalar};
 use mir::visit::MirVisitable;
 use rustc_apfloat::ieee::{Double, Single};
@@ -1789,10 +1788,6 @@ pub enum StatementKind<'tcx> {
     /// for more details.
     EscapeToRaw(Operand<'tcx>),
 
-    /// Mark one terminating point of a region scope (i.e. static region).
-    /// (The starting point(s) arise implicitly from borrows.)
-    EndRegion(region::Scope),
-
     /// Encodes a user's type ascription. These need to be preserved
     /// intact so that NLL can respect them. For example:
     ///
@@ -1846,8 +1841,6 @@ impl<'tcx> Debug for Statement<'tcx> {
         match self.kind {
             Assign(ref place, ref rv) => write!(fmt, "{:?} = {:?}", place, rv),
             FakeRead(ref cause, ref place) => write!(fmt, "FakeRead({:?}, {:?})", cause, place),
-            // (reuse lifetime rendering policy from ppaux.)
-            EndRegion(ref ce) => write!(fmt, "EndRegion({})", ty::ReScope(*ce)),
             Retag { fn_entry, ref place } =>
                 write!(fmt, "Retag({}{:?})", if fn_entry { "[fn entry] " } else { "" }, place),
             EscapeToRaw(ref place) => write!(fmt, "EscapeToRaw({:?})", place),
@@ -3028,7 +3021,6 @@ EnumTypeFoldableImpl! {
         (StatementKind::InlineAsm) { asm, outputs, inputs },
         (StatementKind::Retag) { fn_entry, place },
         (StatementKind::EscapeToRaw)(place),
-        (StatementKind::EndRegion)(a),
         (StatementKind::AscribeUserType)(a, v, b),
         (StatementKind::Nop),
     }

src/librustc/mir/visit.rs

@@ -377,7 +377,6 @@ macro_rules! make_mir_visitor {
                             location
                         );
                     }
-                    StatementKind::EndRegion(_) => {}
                     StatementKind::SetDiscriminant{ ref $($mutability)* place, .. } => {
                         self.visit_place(
                             place,

src/librustc/session/config.rs

@@ -1149,8 +1149,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "when debug-printing compiler state, do not include spans"), // o/w tests have closure@path
     identify_regions: bool = (false, parse_bool, [UNTRACKED],
         "make unnamed regions display as '# (where # is some non-ident unique id)"),
-    emit_end_regions: bool = (false, parse_bool, [UNTRACKED],
-        "emit EndRegion as part of MIR; enable transforms that solely process EndRegion"),
     borrowck: Option<String> = (None, parse_opt_string, [UNTRACKED],
         "select which borrowck is used (`ast`, `mir`, `migrate`, or `compare`)"),
     two_phase_borrows: bool = (false, parse_bool, [UNTRACKED],

src/librustc/ty/context.rs

@@ -1540,13 +1540,6 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
-    /// Should we emit EndRegion MIR statements? These are consumed by
-    /// MIR borrowck, but not when NLL is used.
-    pub fn emit_end_regions(self) -> bool {
-        self.sess.opts.debugging_opts.emit_end_regions ||
-            self.use_mir_borrowck()
-    }
-
     #[inline]
     pub fn local_crate_exports_generics(self) -> bool {
         debug_assert!(self.sess.opts.share_generics());

src/librustc_codegen_ssa/mir/statement.rs

@@ -105,7 +105,6 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 bx
             }
             mir::StatementKind::FakeRead(..) |
-            mir::StatementKind::EndRegion(..) |
             mir::StatementKind::Retag { .. } |
             mir::StatementKind::EscapeToRaw { .. } |
             mir::StatementKind::AscribeUserType(..) |

src/librustc_mir/borrow_check/mod.rs

@@ -592,10 +592,6 @@ impl<'cx, 'gcx, 'tcx> DataflowResultsConsumer<'cx, 'tcx> for MirBorrowckCtxt<'cx
                     self.consume_operand(context, (input, span), flow_state);
                 }
             }
-            StatementKind::EndRegion(ref _rgn) => {
-                // ignored when consuming results (update to
-                // flow_state already handled).
-            }
             StatementKind::Nop
             | StatementKind::AscribeUserType(..)
             | StatementKind::Retag { .. }

src/librustc_mir/borrow_check/nll/invalidation.rs

@@ -132,8 +132,6 @@ impl<'cx, 'tcx, 'gcx> Visitor<'tcx> for InvalidationGenerator<'cx, 'tcx, 'gcx> {
                     self.consume_operand(context, input);
                 }
             }
-            // EndRegion matters to older NLL/MIR AST borrowck, not to alias NLL
-            StatementKind::EndRegion(..) |
             StatementKind::Nop |
             StatementKind::AscribeUserType(..) |
             StatementKind::Retag { .. } |

src/librustc_mir/borrow_check/nll/renumber.rs

@@ -10,7 +10,7 @@
 
 use rustc::ty::subst::Substs;
 use rustc::ty::{self, ClosureSubsts, GeneratorSubsts, Ty, TypeFoldable};
-use rustc::mir::{BasicBlock, Location, Mir, Statement, StatementKind, UserTypeAnnotation};
+use rustc::mir::{Location, Mir, UserTypeAnnotation};
 use rustc::mir::visit::{MutVisitor, TyContext};
 use rustc::infer::{InferCtxt, NLLRegionVariableOrigin};
 
@@ -119,16 +119,4 @@ impl<'a, 'gcx, 'tcx> MutVisitor<'tcx> for NLLVisitor<'a, 'gcx, 'tcx> {
 
         debug!("visit_closure_substs: substs={:?}", substs);
     }
-
-    fn visit_statement(
-        &mut self,
-        block: BasicBlock,
-        statement: &mut Statement<'tcx>,
-        location: Location,
-    ) {
-        if let StatementKind::EndRegion(_) = statement.kind {
-            statement.kind = StatementKind::Nop;
-        }
-        self.super_statement(block, statement, location);
-    }
 }

src/librustc_mir/borrow_check/nll/type_check/mod.rs

@@ -1314,7 +1314,6 @@ impl<'a, 'gcx, 'tcx> TypeChecker<'a, 'gcx, 'tcx> {
             | StatementKind::StorageLive(..)
             | StatementKind::StorageDead(..)
             | StatementKind::InlineAsm { .. }
-            | StatementKind::EndRegion(_)
             | StatementKind::Retag { .. }
             | StatementKind::EscapeToRaw { .. }
             | StatementKind::Nop => {}