prep work for using timely dataflow with NLL

src/librustc/infer/error_reporting/mod.rs

@@ -303,28 +303,28 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     ) {
         debug!("report_region_errors(): {} errors to start", errors.len());
 
-        if will_later_be_reported_by_nll && self.tcx.nll() {
+        if will_later_be_reported_by_nll && self.tcx.use_mir_borrowck() {
             // With `#![feature(nll)]`, we want to present a nice user
             // experience, so don't even mention the errors from the
             // AST checker.
             if self.tcx.features().nll {
                 return;
             }
 
-            // But with -Znll, it's nice to have some note for later.
+            // But with nll, it's nice to have some note for later.
             for error in errors {
                 match *error {
                     RegionResolutionError::ConcreteFailure(ref origin, ..)
                     | RegionResolutionError::GenericBoundFailure(ref origin, ..) => {
                         self.tcx
                             .sess
-                            .span_warn(origin.span(), "not reporting region error due to -Znll");
+                            .span_warn(origin.span(), "not reporting region error due to nll");
                     }
 
                     RegionResolutionError::SubSupConflict(ref rvo, ..) => {
                         self.tcx
                             .sess
-                            .span_warn(rvo.span(), "not reporting region error due to -Znll");
+                            .span_warn(rvo.span(), "not reporting region error due to nll");
                     }
                 }
             }

src/librustc/mir/mod.rs

@@ -1991,7 +1991,7 @@ impl Location {
         Location { block: self.block, statement_index: self.statement_index + 1 }
     }
 
-    pub fn dominates(&self, other: &Location, dominators: &Dominators<BasicBlock>) -> bool {
+    pub fn dominates(&self, other: Location, dominators: &Dominators<BasicBlock>) -> bool {
         if self.block == other.block {
             self.statement_index <= other.statement_index
         } else {

src/librustc/session/config.rs

@@ -1255,8 +1255,6 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         useful for profiling / PGO."),
     relro_level: Option<RelroLevel> = (None, parse_relro_level, [TRACKED],
         "choose which RELRO level to use"),
-    nll: bool = (false, parse_bool, [UNTRACKED],
-                 "run the non-lexical lifetimes MIR pass"),
     disable_nll_user_type_assert: bool = (false, parse_bool, [UNTRACKED],
         "disable user provided type assertion in NLL"),
     trans_time_graph: bool = (false, parse_bool, [UNTRACKED],

src/librustc/ty/context.rs

@@ -1471,15 +1471,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.on_disk_query_result_cache.serialize(self.global_tcx(), encoder)
     }
 
-    /// If true, we should use NLL-style region checking instead of
-    /// lexical style.
-    pub fn nll(self) -> bool {
-        self.features().nll || self.sess.opts.debugging_opts.nll
-    }
-
     /// If true, we should use the MIR-based borrowck (we may *also* use
     /// the AST-based borrowck).
-    pub fn use_mir(self) -> bool {
+    pub fn use_mir_borrowck(self) -> bool {
         self.borrowck_mode().use_mir()
     }
 
@@ -1498,7 +1492,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
             mode @ BorrowckMode::Compare => mode,
 
             mode @ BorrowckMode::Ast => {
-                if self.nll() {
+                if self.features().nll {
                     BorrowckMode::Mir
                 } else {
                     mode
@@ -1512,11 +1506,9 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// MIR borrowck, but not when NLL is used. They are also consumed
     /// by the validation stuff.
     pub fn emit_end_regions(self) -> bool {
-        // FIXME(#46875) -- we should not emit end regions when NLL is enabled,
-        // but for now we can't stop doing so because it causes false positives
         self.sess.opts.debugging_opts.emit_end_regions ||
             self.sess.opts.debugging_opts.mir_emit_validate > 0 ||
-            self.use_mir()
+            self.use_mir_borrowck()
     }
 
     #[inline]