Fix @nikomatsakis' nits in typeck.

src/librustc_typeck/astconv.rs

@@ -622,7 +622,7 @@ pub fn instantiate_trait_ref<'tcx>(
     -> Rc<ty::TraitRef<'tcx>>
 {
     let path = &trait_ref.path;
-    match ::lookup_def_tcx(this.tcx(), path.span, trait_ref.ref_id) {
+    match ::lookup_full_def(this.tcx(), path.span, trait_ref.ref_id) {
         def::DefTrait(trait_def_id) => {
             let trait_ref = ast_path_to_trait_ref(this,
                                                   rscope,
@@ -899,7 +899,10 @@ fn ast_ty_to_trait_ref<'tcx>(this: &AstConv<'tcx>,
 
     match ty.node {
         ast::TyPath(None, ref path) => {
-            let def = this.tcx().def_map.borrow().get(&ty.id).map(|d| d.full_def());
+            let def = match this.tcx().def_map.borrow().get(&ty.id) {
+                Some(&def::PathResolution { base_def, depth: 0, .. }) => Some(base_def),
+                _ => None
+            };
             match def {
                 Some(def::DefTrait(trait_def_id)) => {
                     let mut projection_bounds = Vec::new();
@@ -1202,7 +1205,10 @@ pub fn finish_resolving_def_to_ty<'tcx>(this: &AstConv<'tcx>,
                         segments.last().unwrap())
         }
         def::DefMod(id) => {
-            // Used as sentinel by callers to indicate the `<T>::a::b::c` form.
+            // Used as sentinel by callers to indicate the `<T>::A::B::C` form.
+            // FIXME(#22519) This part of the resolution logic should be
+            // avoided entirely for that form, once we stop needed a Def
+            // for `associated_path_def_to_ty`.
             if segments.is_empty() {
                 opt_self_ty.expect("missing T in <T>::a::b::c")
             } else {
@@ -1890,7 +1896,7 @@ pub fn partition_bounds<'a>(tcx: &ty::ctxt,
     for ast_bound in ast_bounds {
         match *ast_bound {
             ast::TraitTyParamBound(ref b, ast::TraitBoundModifier::None) => {
-                match ::lookup_def_tcx(tcx, b.trait_ref.path.span, b.trait_ref.ref_id) {
+                match ::lookup_full_def(tcx, b.trait_ref.path.span, b.trait_ref.ref_id) {
                     def::DefTrait(trait_did) => {
                         match trait_def_ids.get(&trait_did) {
                             // Already seen this trait. We forbid

src/librustc_typeck/check/mod.rs

@@ -103,7 +103,7 @@ use middle::ty::{MethodCall, MethodCallee, MethodMap, ObjectCastMap};
 use middle::ty_fold::{TypeFolder, TypeFoldable};
 use rscope::RegionScope;
 use session::Session;
-use {CrateCtxt, lookup_def_ccx, require_same_types};
+use {CrateCtxt, lookup_full_def, require_same_types};
 use TypeAndSubsts;
 use lint;
 use util::common::{block_query, indenter, loop_query};
@@ -3401,7 +3401,7 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
               ast::ExprPath(None, ref path) => {
                   // FIXME(pcwalton): For now we hardcode the two permissible
                   // places: the exchange heap and the managed heap.
-                  let definition = lookup_def(fcx, path.span, place.id);
+                  let definition = lookup_full_def(tcx, path.span, place.id);
                   let def_id = definition.def_id();
                   let referent_ty = fcx.expr_ty(&**subexpr);
                   if tcx.lang_items.exchange_heap() == Some(def_id) {
@@ -3884,14 +3884,14 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
       }
       ast::ExprStruct(ref path, ref fields, ref base_expr) => {
         // Resolve the path.
-        let def = tcx.def_map.borrow().get(&id).map(|d| d.full_def());
+        let def = lookup_full_def(tcx, path.span, id);
         let struct_id = match def {
-            Some(def::DefVariant(enum_id, variant_id, true)) => {
+            def::DefVariant(enum_id, variant_id, true) => {
                 check_struct_enum_variant(fcx, id, expr.span, enum_id,
                                           variant_id, &fields[..]);
                 enum_id
             }
-            Some(def::DefTrait(def_id)) => {
+            def::DefTrait(def_id) => {
                 span_err!(tcx.sess, path.span, E0159,
                     "use of trait `{}` as a struct constructor",
                     pprust::path_to_string(path));
@@ -3901,7 +3901,7 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
                                              base_expr);
                 def_id
             },
-            Some(def) => {
+            def => {
                 // Verify that this was actually a struct.
                 let typ = ty::lookup_item_type(fcx.ccx.tcx, def.def_id());
                 match typ.ty.sty {
@@ -3926,10 +3926,6 @@ fn check_expr_with_unifier<'a, 'tcx, F>(fcx: &FnCtxt<'a, 'tcx>,
 
                 def.def_id()
             }
-            _ => {
-                tcx.sess.span_bug(path.span,
-                                  "structure constructor wasn't resolved")
-            }
         };
 
         // Turn the path into a type and verify that that type unifies with
@@ -4643,10 +4639,6 @@ pub fn check_enum_variants<'a,'tcx>(ccx: &CrateCtxt<'a,'tcx>,
     check_instantiable(ccx.tcx, sp, id);
 }
 
-pub fn lookup_def(fcx: &FnCtxt, sp: Span, id: ast::NodeId) -> def::Def {
-    lookup_def_ccx(fcx.ccx, sp, id)
-}
-
 // Returns the type parameter count and the type for the given definition.
 fn type_scheme_and_predicates_for_def<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
                                                 sp: Span,
@@ -5171,18 +5163,15 @@ pub fn may_break(cx: &ty::ctxt, id: ast::NodeId, b: &ast::Block) -> bool {
             _ => false
         }
     })) ||
-   // Second: is there a labeled break with label
+    // Second: is there a labeled break with label
-   // <id> nested anywhere inside the loop?
+    // <id> nested anywhere inside the loop?
     (block_query(b, |e| {
-        match e.node {
+        if let ast::ExprBreak(Some(_)) = e.node {
-            ast::ExprBreak(Some(_)) => {
+            lookup_full_def(cx, e.span, e.id) == def::DefLabel(id)
-                match cx.def_map.borrow().get(&e.id).map(|d| d.full_def()) {
+        } else {
-                    Some(def::DefLabel(loop_id)) if id == loop_id => true,
+            false
-                    _ => false,
+        }
-                }
+    }))
-            }
-            _ => false
-        }}))
 }
 
 pub fn check_bounds_are_used<'a, 'tcx>(ccx: &CrateCtxt<'a, 'tcx>,

src/librustc_typeck/lib.rs

@@ -163,20 +163,16 @@ fn write_substs_to_tcx<'tcx>(tcx: &ty::ctxt<'tcx>,
         tcx.item_substs.borrow_mut().insert(node_id, item_substs);
     }
 }
-fn lookup_def_tcx(tcx:&ty::ctxt, sp: Span, id: ast::NodeId) -> def::Def {
+
+fn lookup_full_def(tcx: &ty::ctxt, sp: Span, id: ast::NodeId) -> def::Def {
     match tcx.def_map.borrow().get(&id) {
         Some(x) => x.full_def(),
-        _ => {
+        None => {
             span_fatal!(tcx.sess, sp, E0242, "internal error looking up a definition")
         }
     }
 }
 
-fn lookup_def_ccx(ccx: &CrateCtxt, sp: Span, id: ast::NodeId)
-                   -> def::Def {
-    lookup_def_tcx(ccx.tcx, sp, id)
-}
-
 fn require_same_types<'a, 'tcx, M>(tcx: &ty::ctxt<'tcx>,
                                    maybe_infcx: Option<&infer::InferCtxt<'a, 'tcx>>,
                                    t1_is_expected: bool,