rustc: rename ProjectionMode and its variant to be more memorable.

Author: eddyb

src/librustc/infer/mod.rs

@@ -34,7 +34,7 @@ use ty::{self, Ty, TyCtxt};
 use ty::error::{ExpectedFound, TypeError, UnconstrainedNumeric};
 use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
 use ty::relate::{Relate, RelateResult, TypeRelation};
-use traits::{self, PredicateObligations, ProjectionMode};
+use traits::{self, PredicateObligations, Reveal};
 use rustc_data_structures::unify::{self, UnificationTable};
 use std::cell::{Cell, RefCell, Ref, RefMut};
 use std::fmt;
@@ -147,8 +147,8 @@ pub struct InferCtxt<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
 
     // Sadly, the behavior of projection varies a bit depending on the
     // stage of compilation. The specifics are given in the
-    // documentation for `ProjectionMode`.
-    projection_mode: ProjectionMode,
+    // documentation for `Reveal`.
+    projection_mode: Reveal,
 
     // When an error occurs, we want to avoid reporting "derived"
     // errors that are due to this original failure. Normally, we
@@ -459,15 +459,15 @@ pub struct InferCtxtBuilder<'a, 'gcx: 'a+'tcx, 'tcx: 'a> {
     arenas: ty::CtxtArenas<'tcx>,
     tables: Option<RefCell<ty::Tables<'tcx>>>,
     param_env: Option<ty::ParameterEnvironment<'gcx>>,
-    projection_mode: ProjectionMode,
+    projection_mode: Reveal,
     normalize: bool
 }
 
 impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'gcx> {
     pub fn infer_ctxt(self,
                       tables: Option<ty::Tables<'tcx>>,
                       param_env: Option<ty::ParameterEnvironment<'gcx>>,
-                      projection_mode: ProjectionMode)
+                      projection_mode: Reveal)
                       -> InferCtxtBuilder<'a, 'gcx, 'tcx> {
         InferCtxtBuilder {
             global_tcx: self,
@@ -479,7 +479,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'gcx> {
         }
     }
 
-    pub fn normalizing_infer_ctxt(self, projection_mode: ProjectionMode)
+    pub fn normalizing_infer_ctxt(self, projection_mode: Reveal)
                                   -> InferCtxtBuilder<'a, 'gcx, 'tcx> {
         InferCtxtBuilder {
             global_tcx: self,
@@ -509,7 +509,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'gcx> {
             projection_cache: RefCell::new(traits::ProjectionCache::new()),
             reported_trait_errors: RefCell::new(FnvHashSet()),
             normalize: false,
-            projection_mode: ProjectionMode::AnyFinal,
+            projection_mode: Reveal::NotSpecializable,
             tainted_by_errors_flag: Cell::new(false),
             err_count_on_creation: self.sess.err_count(),
             obligations_in_snapshot: Cell::new(false),
@@ -641,7 +641,7 @@ impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> {
             return value;
         }
 
-        self.infer_ctxt(None, None, ProjectionMode::Any).enter(|infcx| {
+        self.infer_ctxt(None, None, Reveal::All).enter(|infcx| {
             value.trans_normalize(&infcx)
         })
     }
@@ -659,7 +659,7 @@ impl<'a, 'tcx> TyCtxt<'a, 'tcx, 'tcx> {
             return value;
         }
 
-        self.infer_ctxt(None, Some(env.clone()), ProjectionMode::Any).enter(|infcx| {
+        self.infer_ctxt(None, Some(env.clone()), Reveal::All).enter(|infcx| {
             value.trans_normalize(&infcx)
        })
     }
@@ -736,7 +736,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         Ok(self.tcx.erase_regions(&result))
     }
 
-    pub fn projection_mode(&self) -> ProjectionMode {
+    pub fn projection_mode(&self) -> Reveal {
         self.projection_mode
     }
 

src/librustc/middle/intrinsicck.rs

@@ -12,7 +12,7 @@ use dep_graph::DepNode;
 use hir::def::Def;
 use hir::def_id::DefId;
 use infer::InferCtxt;
-use traits::ProjectionMode;
+use traits::Reveal;
 use ty::{self, Ty, TyCtxt};
 use ty::layout::{LayoutError, Pointer, SizeSkeleton};
 
@@ -36,7 +36,7 @@ struct ItemVisitor<'a, 'tcx: 'a> {
 impl<'a, 'tcx> ItemVisitor<'a, 'tcx> {
     fn visit_const(&mut self, item_id: ast::NodeId, expr: &hir::Expr) {
         let param_env = ty::ParameterEnvironment::for_item(self.tcx, item_id);
-        self.tcx.infer_ctxt(None, Some(param_env), ProjectionMode::Any).enter(|infcx| {
+        self.tcx.infer_ctxt(None, Some(param_env), Reveal::All).enter(|infcx| {
             let mut visitor = ExprVisitor {
                 infcx: &infcx
             };
@@ -114,7 +114,7 @@ impl<'a, 'gcx, 'tcx> ExprVisitor<'a, 'gcx, 'tcx> {
 impl<'a, 'tcx, 'v> Visitor<'v> for ItemVisitor<'a, 'tcx> {
     // const, static and N in [T; N].
     fn visit_expr(&mut self, expr: &hir::Expr) {
-        self.tcx.infer_ctxt(None, None, ProjectionMode::Any).enter(|infcx| {
+        self.tcx.infer_ctxt(None, None, Reveal::All).enter(|infcx| {
             let mut visitor = ExprVisitor {
                 infcx: &infcx
             };
@@ -144,7 +144,7 @@ impl<'a, 'tcx, 'v> Visitor<'v> for ItemVisitor<'a, 'tcx> {
             span_bug!(s, "intrinsicck: closure outside of function")
         }
         let param_env = ty::ParameterEnvironment::for_item(self.tcx, id);
-        self.tcx.infer_ctxt(None, Some(param_env), ProjectionMode::Any).enter(|infcx| {
+        self.tcx.infer_ctxt(None, Some(param_env), Reveal::All).enter(|infcx| {
             let mut visitor = ExprVisitor {
                 infcx: &infcx
             };

src/librustc/middle/liveness.rs

@@ -113,7 +113,7 @@ use dep_graph::DepNode;
 use hir::def::*;
 use hir::pat_util;
 use ty::{self, TyCtxt, ParameterEnvironment};
-use traits::{self, ProjectionMode};
+use traits::{self, Reveal};
 use ty::subst::Subst;
 use lint;
 use util::nodemap::NodeMap;
@@ -1484,7 +1484,7 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
                 let param_env = ParameterEnvironment::for_item(self.ir.tcx, id);
                 let t_ret_subst = t_ret.subst(self.ir.tcx, &param_env.free_substs);
                 let is_nil = self.ir.tcx.infer_ctxt(None, Some(param_env),
-                                                    ProjectionMode::Any).enter(|infcx| {
+                                                    Reveal::All).enter(|infcx| {
                     let cause = traits::ObligationCause::dummy();
                     traits::fully_normalize(&infcx, cause, &t_ret_subst).unwrap().is_nil()
                 });

src/librustc/traits/mod.rs

@@ -32,7 +32,7 @@ pub use self::coherence::OrphanCheckErr;
 pub use self::fulfill::{FulfillmentContext, GlobalFulfilledPredicates, RegionObligation};
 pub use self::project::MismatchedProjectionTypes;
 pub use self::project::{normalize, normalize_projection_type, Normalized};
-pub use self::project::{ProjectionCache, ProjectionCacheSnapshot, ProjectionMode};
+pub use self::project::{ProjectionCache, ProjectionCacheSnapshot, Reveal};
 pub use self::object_safety::ObjectSafetyViolation;
 pub use self::object_safety::MethodViolationCode;
 pub use self::select::{EvaluationCache, SelectionContext, SelectionCache};
@@ -435,7 +435,7 @@ pub fn normalize_param_env_or_error<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
 
     let elaborated_env = unnormalized_env.with_caller_bounds(predicates);
 
-    tcx.infer_ctxt(None, Some(elaborated_env), ProjectionMode::AnyFinal).enter(|infcx| {
+    tcx.infer_ctxt(None, Some(elaborated_env), Reveal::NotSpecializable).enter(|infcx| {
         let predicates = match fully_normalize(&infcx, cause,
                                                &infcx.parameter_environment.caller_bounds) {
             Ok(predicates) => predicates,

src/librustc/traits/project.rs

@@ -38,7 +38,7 @@ use std::rc::Rc;
 /// Depending on the stage of compilation, we want projection to be
 /// more or less conservative.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
-pub enum ProjectionMode {
+pub enum Reveal {
     /// FIXME (#32205)
     /// At coherence-checking time, we're still constructing the
     /// specialization graph, and thus we only project
@@ -67,7 +67,7 @@ pub enum ProjectionMode {
     ///
     /// The projection would succeed if `Output` had been defined
     /// directly in the impl for `u8`.
-    Topmost,
+    ExactMatch,
 
     /// At type-checking time, we refuse to project any associated
     /// type that is marked `default`. Non-`default` ("final") types
@@ -91,36 +91,12 @@ pub enum ProjectionMode {
     /// fn main() {
     ///     let <() as Assoc>::Output = true;
     /// }
-    AnyFinal,
+    NotSpecializable,
 
     /// At trans time, all projections will succeed.
-    Any,
+    All,
 }
 
-impl ProjectionMode {
-    pub fn is_topmost(&self) -> bool {
-        match *self {
-            ProjectionMode::Topmost => true,
-            _ => false,
-        }
-    }
-
-    pub fn is_any_final(&self) -> bool {
-        match *self {
-            ProjectionMode::AnyFinal => true,
-            _ => false,
-        }
-    }
-
-    pub fn is_any(&self) -> bool {
-        match *self {
-            ProjectionMode::Any => true,
-            _ => false,
-        }
-    }
-}
-
-
 pub type PolyProjectionObligation<'tcx> =
     Obligation<'tcx, ty::PolyProjectionPredicate<'tcx>>;
 
@@ -902,7 +878,7 @@ fn assemble_candidates_from_impls<'cx, 'gcx, 'tcx>(
 
                 candidate_set.vec.push(ProjectionTyCandidate::Select);
             }
-            super::VtableImpl(ref impl_data) if !selcx.projection_mode().is_any() => {
+            super::VtableImpl(ref impl_data) if selcx.projection_mode() != Reveal::All => {
                 // We have to be careful when projecting out of an
                 // impl because of specialization. If we are not in
                 // trans (i.e., projection mode is not "any"), and the
@@ -1008,7 +984,7 @@ fn assemble_candidates_from_impls<'cx, 'gcx, 'tcx>(
             }
             super::VtableImpl(_) => {
                 // In trans mode, we can just project out of impls, no prob.
-                assert!(selcx.projection_mode().is_any());
+                assert!(selcx.projection_mode() == Reveal::All);
                 candidate_set.vec.push(ProjectionTyCandidate::Select);
             }
             super::VtableParam(..) => {
@@ -1332,7 +1308,7 @@ fn confirm_impl_candidate<'cx, 'gcx, 'tcx>(
 /// starting from the given impl.
 ///
 /// Based on the "projection mode", this lookup may in fact only examine the
-/// topmost impl. See the comments for `ProjectionMode` for more details.
+/// topmost impl. See the comments for `Reveal` for more details.
 fn assoc_ty_def<'cx, 'gcx, 'tcx>(
     selcx: &SelectionContext<'cx, 'gcx, 'tcx>,
     impl_def_id: DefId,
@@ -1341,7 +1317,7 @@ fn assoc_ty_def<'cx, 'gcx, 'tcx>(
 {
     let trait_def_id = selcx.tcx().impl_trait_ref(impl_def_id).unwrap().def_id;
 
-    if selcx.projection_mode().is_topmost() {
+    if selcx.projection_mode() == Reveal::ExactMatch {
         let impl_node = specialization_graph::Node::Impl(impl_def_id);
         for item in impl_node.items(selcx.tcx()) {
             if let ty::TypeTraitItem(assoc_ty) = item {

src/librustc/traits/select.rs

@@ -23,7 +23,7 @@ use super::{PredicateObligation, TraitObligation, ObligationCause};
 use super::{ObligationCauseCode, BuiltinDerivedObligation, ImplDerivedObligation};
 use super::{SelectionError, Unimplemented, OutputTypeParameterMismatch};
 use super::{ObjectCastObligation, Obligation};
-use super::ProjectionMode;
+use super::Reveal;
 use super::TraitNotObjectSafe;
 use super::Selection;
 use super::SelectionResult;
@@ -343,7 +343,7 @@ impl<'cx, 'gcx, 'tcx> SelectionContext<'cx, 'gcx, 'tcx> {
         self.infcx
     }
 
-    pub fn projection_mode(&self) -> ProjectionMode {
+    pub fn projection_mode(&self) -> Reveal {
         self.infcx.projection_mode()
     }
 

src/librustc/traits/specialize/mod.rs

@@ -25,7 +25,7 @@ use hir::def_id::DefId;
 use infer::{InferCtxt, TypeOrigin};
 use middle::region;
 use ty::subst::{Subst, Substs};
-use traits::{self, ProjectionMode, ObligationCause, Normalized};
+use traits::{self, Reveal, ObligationCause, Normalized};
 use ty::{self, TyCtxt};
 use syntax_pos::DUMMY_SP;
 
@@ -151,7 +151,7 @@ pub fn specializes<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
                              .unwrap()
                              .subst(tcx, &penv.free_substs);
 
-    let result = tcx.normalizing_infer_ctxt(ProjectionMode::Topmost).enter(|mut infcx| {
+    let result = tcx.normalizing_infer_ctxt(Reveal::ExactMatch).enter(|mut infcx| {
         // Normalize the trait reference, adding any obligations
         // that arise into the impl1 assumptions.
         let Normalized { value: impl1_trait_ref, obligations: normalization_obligations } = {

src/librustc/traits/specialize/specialization_graph.rs

@@ -14,7 +14,7 @@ use std::rc::Rc;
 use super::{OverlapError, specializes};
 
 use hir::def_id::DefId;
-use traits::{self, ProjectionMode};
+use traits::{self, Reveal};
 use ty::{self, TyCtxt, ImplOrTraitItem, TraitDef, TypeFoldable};
 use ty::fast_reject::{self, SimplifiedType};
 use syntax::ast::Name;
@@ -111,8 +111,7 @@ impl<'a, 'gcx, 'tcx> Children {
             let possible_sibling = *slot;
 
             let tcx = tcx.global_tcx();
-            let (le, ge) = tcx.infer_ctxt(None, None,
-                                          ProjectionMode::Topmost).enter(|infcx| {
+            let (le, ge) = tcx.infer_ctxt(None, None, Reveal::ExactMatch).enter(|infcx| {
                 let overlap = traits::overlapping_impls(&infcx,
                                                         possible_sibling,
                                                         impl_def_id);

src/librustc/ty/util.rs

@@ -14,7 +14,7 @@ use hir::def_id::DefId;
 use ty::subst;
 use infer::InferCtxt;
 use hir::pat_util;
-use traits::{self, ProjectionMode};
+use traits::{self, Reveal};
 use ty::{self, Ty, TyCtxt, TypeAndMut, TypeFlags, TypeFoldable};
 use ty::{Disr, ParameterEnvironment};
 use ty::fold::TypeVisitor;
@@ -137,8 +137,7 @@ impl<'tcx> ParameterEnvironment<'tcx> {
                                        self_type: Ty<'tcx>, span: Span)
                                        -> Result<(),CopyImplementationError> {
         // FIXME: (@jroesch) float this code up
-        tcx.infer_ctxt(None, Some(self.clone()),
-                       ProjectionMode::Topmost).enter(|infcx| {
+        tcx.infer_ctxt(None, Some(self.clone()), Reveal::ExactMatch).enter(|infcx| {
             let adt = match self_type.sty {
                 ty::TyStruct(struct_def, substs) => {
                     for field in struct_def.all_fields() {
@@ -533,7 +532,7 @@ impl<'a, 'tcx> ty::TyS<'tcx> {
                    param_env: &ParameterEnvironment<'tcx>,
                    bound: ty::BuiltinBound, span: Span) -> bool
     {
-        tcx.infer_ctxt(None, Some(param_env.clone()), ProjectionMode::Topmost).enter(|infcx| {
+        tcx.infer_ctxt(None, Some(param_env.clone()), Reveal::ExactMatch).enter(|infcx| {
             traits::type_known_to_meet_builtin_bound(&infcx, self, bound, span)
         })
     }

src/librustc_const_eval/check_match.rs

@@ -25,7 +25,7 @@ use rustc::middle::expr_use_visitor::{LoanCause, MutateMode};
 use rustc::middle::expr_use_visitor as euv;
 use rustc::middle::mem_categorization::{cmt};
 use rustc::hir::pat_util::*;
-use rustc::traits::ProjectionMode;
+use rustc::traits::Reveal;
 use rustc::ty::*;
 use rustc::ty;
 use std::cmp::Ordering;
@@ -1133,7 +1133,7 @@ fn check_legality_of_move_bindings(cx: &MatchCheckCtxt,
                 let pat_ty = cx.tcx.node_id_to_type(p.id);
                 //FIXME: (@jroesch) this code should be floated up as well
                 cx.tcx.infer_ctxt(None, Some(cx.param_env.clone()),
-                                  ProjectionMode::AnyFinal).enter(|infcx| {
+                                  Reveal::NotSpecializable).enter(|infcx| {
                     if infcx.type_moves_by_default(pat_ty, pat.span) {
                         check_move(p, sub.as_ref().map(|p| &**p));
                     }
@@ -1149,7 +1149,7 @@ fn check_legality_of_move_bindings(cx: &MatchCheckCtxt,
 fn check_for_mutation_in_guard<'a, 'tcx>(cx: &'a MatchCheckCtxt<'a, 'tcx>,
                                          guard: &hir::Expr) {
     cx.tcx.infer_ctxt(None, Some(cx.param_env.clone()),
-                      ProjectionMode::AnyFinal).enter(|infcx| {
+                      Reveal::NotSpecializable).enter(|infcx| {
         let mut checker = MutationChecker {
             cx: cx,
         };

src/librustc_const_eval/eval.rs

@@ -24,7 +24,7 @@ use rustc::hir::def_id::DefId;
 use rustc::hir::pat_util::def_to_path;
 use rustc::ty::{self, Ty, TyCtxt, subst};
 use rustc::ty::util::IntTypeExt;
-use rustc::traits::ProjectionMode;
+use rustc::traits::Reveal;
 use rustc::util::common::ErrorReported;
 use rustc::util::nodemap::NodeMap;
 use rustc::lint;
@@ -1055,7 +1055,7 @@ fn resolve_trait_associated_const<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
            trait_ref);
 
     tcx.populate_implementations_for_trait_if_necessary(trait_ref.def_id());
-    tcx.infer_ctxt(None, None, ProjectionMode::AnyFinal).enter(|infcx| {
+    tcx.infer_ctxt(None, None, Reveal::NotSpecializable).enter(|infcx| {
         let mut selcx = traits::SelectionContext::new(&infcx);
         let obligation = traits::Obligation::new(traits::ObligationCause::dummy(),
                                                  trait_ref.to_poly_trait_predicate());
@@ -1073,9 +1073,9 @@ fn resolve_trait_associated_const<'a, 'tcx: 'a>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
         };
 
         // NOTE: this code does not currently account for specialization, but when
-        // it does so, it should hook into the ProjectionMode to determine when the
+        // it does so, it should hook into the Reveal to determine when the
         // constant should resolve; this will also require plumbing through to this
-        // function whether we are in "trans mode" to pick the right ProjectionMode
+        // function whether we are in "trans mode" to pick the right Reveal
         // when constructing the inference context above.
         match selection {
             traits::VtableImpl(ref impl_data) => {