store RegionVariableInfo and not just RegionVariableOrigin

Author: sgrif

src/librustc/infer/lexical_region_resolve/mod.rs

@@ -15,7 +15,7 @@ use infer::RegionVariableOrigin;
 use infer::region_constraints::Constraint;
 use infer::region_constraints::GenericKind;
 use infer::region_constraints::RegionConstraintData;
-use infer::region_constraints::VarOrigins;
+use infer::region_constraints::VarInfos;
 use infer::region_constraints::VerifyBound;
 use middle::free_region::RegionRelations;
 use rustc_data_structures::indexed_vec::{Idx, IndexVec};
@@ -37,7 +37,7 @@ mod graphviz;
 /// all the variables as well as a set of errors that must be reported.
 pub fn resolve<'tcx>(
     region_rels: &RegionRelations<'_, '_, 'tcx>,
-    var_origins: VarOrigins,
+    var_infos: VarInfos,
     data: RegionConstraintData<'tcx>,
 ) -> (
     LexicalRegionResolutions<'tcx>,
@@ -47,7 +47,7 @@ pub fn resolve<'tcx>(
     let mut errors = vec![];
     let mut resolver = LexicalResolver {
         region_rels,
-        var_origins,
+        var_infos,
         data,
     };
     let values = resolver.infer_variable_values(&mut errors);
@@ -103,7 +103,7 @@ type RegionGraph<'tcx> = graph::Graph<(), Constraint<'tcx>>;
 
 struct LexicalResolver<'cx, 'gcx: 'tcx, 'tcx: 'cx> {
     region_rels: &'cx RegionRelations<'cx, 'gcx, 'tcx>,
-    var_origins: VarOrigins,
+    var_infos: VarInfos,
     data: RegionConstraintData<'tcx>,
 }
 
@@ -132,7 +132,7 @@ impl<'cx, 'gcx, 'tcx> LexicalResolver<'cx, 'gcx, 'tcx> {
     }
 
     fn num_vars(&self) -> usize {
-        self.var_origins.len()
+        self.var_infos.len()
     }
 
     /// Initially, the value for all variables is set to `'empty`, the
@@ -279,7 +279,7 @@ impl<'cx, 'gcx, 'tcx> LexicalResolver<'cx, 'gcx, 'tcx> {
 
             (&ReVar(v_id), _) | (_, &ReVar(v_id)) => {
                 span_bug!(
-                    self.var_origins[v_id].span(),
+                    self.var_infos[v_id].origin.span(),
                     "lub_concrete_regions invoked with non-concrete \
                      regions: {:?}, {:?}",
                     a,
@@ -576,7 +576,7 @@ impl<'cx, 'gcx, 'tcx> LexicalResolver<'cx, 'gcx, 'tcx> {
                 if !self.region_rels
                     .is_subregion_of(lower_bound.region, upper_bound.region)
                 {
-                    let origin = self.var_origins[node_idx].clone();
+                    let origin = self.var_infos[node_idx].origin.clone();
                     debug!(
                         "region inference error at {:?} for {:?}: SubSupConflict sub: {:?} \
                          sup: {:?}",
@@ -598,7 +598,7 @@ impl<'cx, 'gcx, 'tcx> LexicalResolver<'cx, 'gcx, 'tcx> {
         }
 
         span_bug!(
-            self.var_origins[node_idx].span(),
+            self.var_infos[node_idx].origin.span(),
             "collect_error_for_expanding_node() could not find \
              error for var {:?}, lower_bounds={:?}, \
              upper_bounds={:?}",

src/librustc/infer/mod.rs

@@ -42,7 +42,7 @@ use arena::SyncDroplessArena;
 use self::combine::CombineFields;
 use self::higher_ranked::HrMatchResult;
 use self::region_constraints::{RegionConstraintCollector, RegionSnapshot};
-use self::region_constraints::{GenericKind, VerifyBound, RegionConstraintData, VarOrigins};
+use self::region_constraints::{GenericKind, VerifyBound, RegionConstraintData, VarInfos};
 use self::lexical_region_resolve::LexicalRegionResolutions;
 use self::outlives::env::OutlivesEnvironment;
 use self::type_variable::TypeVariableOrigin;
@@ -889,7 +889,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
     /// Number of region variables created so far.
     pub fn num_region_vars(&self) -> usize {
-        self.borrow_region_constraints().var_origins().len()
+        self.borrow_region_constraints().num_region_vars()
     }
 
     /// Just a convenient wrapper of `next_region_var` for using during NLL.
@@ -1017,12 +1017,12 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                                                 region_context,
                                                 region_map,
                                                 outlives_env.free_region_map());
-        let (var_origins, data) = self.region_constraints.borrow_mut()
+        let (var_infos, data) = self.region_constraints.borrow_mut()
                                                          .take()
                                                          .expect("regions already resolved")
-                                                         .into_origins_and_data();
+                                                         .into_infos_and_data();
         let (lexical_region_resolutions, errors) =
-            lexical_region_resolve::resolve(region_rels, var_origins, data);
+            lexical_region_resolve::resolve(region_rels, var_infos, data);
 
         let old_value = self.lexical_region_resolutions.replace(Some(lexical_region_resolutions));
         assert!(old_value.is_none());
@@ -1070,13 +1070,13 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     /// hence that `resolve_regions_and_report_errors` can never be
     /// called. This is used only during NLL processing to "hand off" ownership
     /// of the set of region vairables into the NLL region context.
-    pub fn take_region_var_origins(&self) -> VarOrigins {
-        let (var_origins, data) = self.region_constraints.borrow_mut()
+    pub fn take_region_var_origins(&self) -> VarInfos {
+        let (var_infos, data) = self.region_constraints.borrow_mut()
                                                          .take()
                                                          .expect("regions already resolved")
-                                                         .into_origins_and_data();
+                                                         .into_infos_and_data();
         assert!(data.is_empty());
-        var_origins
+        var_infos
     }
 
     pub fn ty_to_string(&self, t: Ty<'tcx>) -> String {

src/librustc/infer/region_constraints/mod.rs

@@ -33,7 +33,7 @@ mod taint;
 
 pub struct RegionConstraintCollector<'tcx> {
     /// For each `RegionVid`, the corresponding `RegionVariableOrigin`.
-    var_origins: IndexVec<RegionVid, RegionVariableOrigin>,
+    var_infos: IndexVec<RegionVid, RegionVariableInfo>,
 
     data: RegionConstraintData<'tcx>,
 
@@ -76,7 +76,7 @@ pub struct RegionConstraintCollector<'tcx> {
     unification_table: ut::UnificationTable<ut::InPlace<ty::RegionVid>>,
 }
 
-pub type VarOrigins = IndexVec<RegionVid, RegionVariableOrigin>;
+pub type VarInfos = IndexVec<RegionVid, RegionVariableInfo>;
 
 /// The full set of region constraints gathered up by the collector.
 /// Describes constraints between the region variables and other
@@ -230,6 +230,11 @@ enum CombineMapType {
 
 type CombineMap<'tcx> = FxHashMap<TwoRegions<'tcx>, RegionVid>;
 
+#[derive(Debug, Clone, Copy)]
+pub struct RegionVariableInfo {
+    pub origin: RegionVariableOrigin,
+}
+
 pub struct RegionSnapshot {
     length: usize,
     region_snapshot: ut::Snapshot<ut::InPlace<ty::RegionVid>>,
@@ -273,7 +278,7 @@ impl TaintDirections {
 impl<'tcx> RegionConstraintCollector<'tcx> {
     pub fn new() -> RegionConstraintCollector<'tcx> {
         RegionConstraintCollector {
-            var_origins: VarOrigins::default(),
+            var_infos: VarInfos::default(),
             data: RegionConstraintData::default(),
             lubs: FxHashMap(),
             glbs: FxHashMap(),
@@ -284,8 +289,8 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
         }
     }
 
-    pub fn var_origins(&self) -> &VarOrigins {
-        &self.var_origins
+    pub fn num_region_vars(&self) -> usize {
+        self.var_infos.len()
     }
 
     pub fn region_constraint_data(&self) -> &RegionConstraintData<'tcx> {
@@ -295,9 +300,9 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
     /// Once all the constraints have been gathered, extract out the final data.
     ///
     /// Not legal during a snapshot.
-    pub fn into_origins_and_data(self) -> (VarOrigins, RegionConstraintData<'tcx>) {
+    pub fn into_infos_and_data(self) -> (VarInfos, RegionConstraintData<'tcx>) {
         assert!(!self.in_snapshot());
-        (self.var_origins, self.data)
+        (self.var_infos, self.data)
     }
 
     /// Takes (and clears) the current set of constraints. Note that
@@ -319,7 +324,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
         // should think carefully about whether it needs to be cleared
         // or updated in some way.
         let RegionConstraintCollector {
-            var_origins,
+            var_infos,
             data,
             lubs,
             glbs,
@@ -343,7 +348,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
         // also insert `a <= b` and a `b <= a` edges, so the
         // `RegionConstraintData` contains the relationship here.
         *unification_table = ut::UnificationTable::new();
-        for vid in var_origins.indices() {
+        for vid in var_infos.indices() {
             unification_table.new_key(unify_key::RegionVidKey { min_vid: vid });
         }
 
@@ -411,8 +416,8 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
                 // nothing to do here
             }
             AddVar(vid) => {
-                self.var_origins.pop().unwrap();
-                assert_eq!(self.var_origins.len(), vid.index() as usize);
+                self.var_infos.pop().unwrap();
+                assert_eq!(self.var_infos.len(), vid.index() as usize);
             }
             AddConstraint(ref constraint) => {
                 self.data.constraints.remove(constraint);
@@ -434,7 +439,9 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
     }
 
     pub fn new_region_var(&mut self, origin: RegionVariableOrigin) -> RegionVid {
-        let vid = self.var_origins.push(origin.clone());
+        let vid = self.var_infos.push(RegionVariableInfo {
+            origin,
+        });
 
         let u_vid = self.unification_table
             .new_key(unify_key::RegionVidKey { min_vid: vid });
@@ -452,7 +459,7 @@ impl<'tcx> RegionConstraintCollector<'tcx> {
 
     /// Returns the origin for the given variable.
     pub fn var_origin(&self, vid: RegionVid) -> RegionVariableOrigin {
-        self.var_origins[vid].clone()
+        self.var_infos[vid].origin
     }
 
     /// Creates a new skolemized region. Skolemized regions are fresh

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

@@ -16,7 +16,7 @@ use rustc::infer::RegionObligation;
 use rustc::infer::RegionVariableOrigin;
 use rustc::infer::SubregionOrigin;
 use rustc::infer::error_reporting::nice_region_error::NiceRegionError;
-use rustc::infer::region_constraints::{GenericKind, VarOrigins};
+use rustc::infer::region_constraints::{GenericKind, VarInfos};
 use rustc::mir::{ClosureOutlivesRequirement, ClosureOutlivesSubject, ClosureRegionRequirements,
                  Local, Location, Mir};
 use rustc::traits::ObligationCause;
@@ -256,19 +256,19 @@ impl<'tcx> RegionInferenceContext<'tcx> {
     /// of those will be constant regions representing the free
     /// regions defined in `universal_regions`.
     pub(crate) fn new(
-        var_origins: VarOrigins,
+        var_infos: VarInfos,
         universal_regions: UniversalRegions<'tcx>,
         mir: &Mir<'tcx>,
     ) -> Self {
-        let num_region_variables = var_origins.len();
+        let num_region_variables = var_infos.len();
         let num_universal_regions = universal_regions.len();
 
         let elements = &Rc::new(RegionValueElements::new(mir, num_universal_regions));
 
         // Create a RegionDefinition for each inference variable.
-        let definitions = var_origins
+        let definitions = var_infos
             .into_iter()
-            .map(|origin| RegionDefinition::new(origin))
+            .map(|info| RegionDefinition::new(info.origin))
             .collect();
 
         let mut result = Self {