Rewrite check_pat_enum, split it into check_pat_tuple_struct and check_pat_path

Update definitions in def_map for associated types written in unqualified form (like `Self::Output`)
Cleanup finish_resolving_def_to_ty/resolve_ty_and_def_ufcs
Make VariantDef's available through constructor IDs

Author: petrochenkov

src/librustc/hir/def.rs

@@ -137,15 +137,6 @@ impl Def {
         }
     }
 
-    pub fn variant_def_ids(&self) -> Option<(DefId, DefId)> {
-        match *self {
-            Def::Variant(enum_id, var_id) => {
-                Some((enum_id, var_id))
-            }
-            _ => None
-        }
-    }
-
     pub fn kind_name(&self) -> &'static str {
         match *self {
             Def::Fn(..) => "function",

src/librustc/hir/pat_util.rs

@@ -12,15 +12,12 @@ use hir::def::*;
 use hir::def_id::DefId;
 use hir::{self, PatKind};
 use ty::TyCtxt;
-use util::nodemap::FnvHashMap;
 use syntax::ast;
 use syntax::codemap::Spanned;
 use syntax_pos::{Span, DUMMY_SP};
 
 use std::iter::{Enumerate, ExactSizeIterator};
 
-pub type PatIdMap = FnvHashMap<ast::Name, ast::NodeId>;
-
 pub struct EnumerateAndAdjust<I> {
     enumerate: Enumerate<I>,
     gap_pos: usize,
@@ -97,22 +94,6 @@ pub fn pat_is_const(dm: &DefMap, pat: &hir::Pat) -> bool {
     }
 }
 
-// Same as above, except that partially-resolved defs cause `false` to be
-// returned instead of a panic.
-pub fn pat_is_resolved_const(dm: &DefMap, pat: &hir::Pat) -> bool {
-    match pat.node {
-        PatKind::Path(..) | PatKind::QPath(..) => {
-            match dm.get(&pat.id)
-                    .and_then(|d| if d.depth == 0 { Some(d.base_def) }
-                                  else { None } ) {
-                Some(Def::Const(..)) | Some(Def::AssociatedConst(..)) => true,
-                _ => false
-            }
-        }
-        _ => false
-    }
-}
-
 /// Call `f` on every "binding" in a pattern, e.g., on `a` in
 /// `match foo() { Some(a) => (), None => () }`
 pub fn pat_bindings<F>(pat: &hir::Pat, mut f: F)

src/librustc/ty/context.rs

@@ -591,17 +591,21 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.global_interners.arenas.trait_defs.alloc(def)
     }
 
+    pub fn insert_adt_def(self, did: DefId, adt_def: ty::AdtDefMaster<'gcx>) {
+        // this will need a transmute when reverse-variance is removed
+        if let Some(prev) = self.adt_defs.borrow_mut().insert(did, adt_def) {
+            bug!("Tried to overwrite interned AdtDef: {:?}", prev)
+        }
+    }
+
     pub fn intern_adt_def(self,
                           did: DefId,
                           kind: ty::AdtKind,
                           variants: Vec<ty::VariantDefData<'gcx, 'gcx>>)
                           -> ty::AdtDefMaster<'gcx> {
         let def = ty::AdtDefData::new(self, did, kind, variants);
         let interned = self.global_interners.arenas.adt_defs.alloc(def);
-        // this will need a transmute when reverse-variance is removed
-        if let Some(prev) = self.adt_defs.borrow_mut().insert(did, interned) {
-            bug!("Tried to overwrite interned AdtDef: {:?}", prev)
-        }
+        self.insert_adt_def(did, interned);
         interned
     }
 

src/librustc/ty/mod.rs

@@ -2454,6 +2454,20 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
         self.def_map.borrow().get(&id).map(|resolution| resolution.full_def())
     }
 
+    // Returns `ty::VariantDef` if `def` refers to a struct,
+    // or variant or their constructors, panics otherwise.
+    pub fn expect_variant_def(self, def: Def) -> VariantDef<'tcx> {
+        match def {
+            Def::Variant(enum_did, did) => {
+                self.lookup_adt_def(enum_did).variant_with_id(did)
+            }
+            Def::Struct(did) => {
+                self.lookup_adt_def(did).struct_variant()
+            }
+            _ => bug!("expect_variant_def used with unexpected def {:?}", def)
+        }
+    }
+
     pub fn def_key(self, id: DefId) -> ast_map::DefKey {
         if id.is_local() {
             self.map.def_key(id)

src/librustc_metadata/decoder.rs

@@ -471,23 +471,29 @@ pub fn get_adt_def<'a, 'tcx>(intr: &IdentInterner,
 
     let doc = cdata.lookup_item(item_id);
     let did = DefId { krate: cdata.cnum, index: item_id };
+    let mut ctor_did = None;
     let (kind, variants) = match item_family(doc) {
         Enum => {
             (ty::AdtKind::Enum,
              get_enum_variants(intr, cdata, doc))
         }
         Struct(..) => {
-            let ctor_did =
-                reader::maybe_get_doc(doc, tag_items_data_item_struct_ctor).
-                map_or(did, |ctor_doc| translated_def_id(cdata, ctor_doc));
+            // Use separate constructor id for unit/tuple structs and reuse did for braced structs.
+            ctor_did = reader::maybe_get_doc(doc, tag_items_data_item_struct_ctor).map(|ctor_doc| {
+                translated_def_id(cdata, ctor_doc)
+            });
             (ty::AdtKind::Struct,
-             vec![get_struct_variant(intr, cdata, doc, ctor_did)])
+             vec![get_struct_variant(intr, cdata, doc, ctor_did.unwrap_or(did))])
         }
         _ => bug!("get_adt_def called on a non-ADT {:?} - {:?}",
                   item_family(doc), did)
     };
 
     let adt = tcx.intern_adt_def(did, kind, variants);
+    if let Some(ctor_did) = ctor_did {
+        // Make adt definition available through constructor id as well.
+        tcx.insert_adt_def(ctor_did, adt);
+    }
 
     // this needs to be done *after* the variant is interned,
     // to support recursive structures

src/librustc_typeck/astconv.rs

@@ -53,7 +53,7 @@ use rustc_const_eval::{eval_const_expr_partial, ConstEvalErr};
 use rustc_const_eval::EvalHint::UncheckedExprHint;
 use rustc_const_eval::ErrKind::ErroneousReferencedConstant;
 use hir::{self, SelfKind};
-use hir::def::{self, Def};
+use hir::def::{Def, PathResolution};
 use hir::def_id::DefId;
 use hir::print as pprust;
 use middle::resolve_lifetime as rl;
@@ -1327,7 +1327,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                 };
 
                 if self.ensure_super_predicates(span, trait_did).is_err() {
-                    return (tcx.types.err, ty_path_def);
+                    return (tcx.types.err, Def::Err);
                 }
 
                 let candidates: Vec<ty::PolyTraitRef> =
@@ -1341,7 +1341,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                                                     &assoc_name.as_str(),
                                                     span) {
                     Ok(bound) => bound,
-                    Err(ErrorReported) => return (tcx.types.err, ty_path_def),
+                    Err(ErrorReported) => return (tcx.types.err, Def::Err),
                 }
             }
             (&ty::TyParam(_), Def::SelfTy(Some(trait_did), None)) => {
@@ -1351,7 +1351,7 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                                                      assoc_name,
                                                      span) {
                     Ok(bound) => bound,
-                    Err(ErrorReported) => return (tcx.types.err, ty_path_def),
+                    Err(ErrorReported) => return (tcx.types.err, Def::Err),
                 }
             }
             (&ty::TyParam(_), Def::TyParam(_, _, param_did, param_name)) => {
@@ -1361,15 +1361,15 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
                                                      assoc_name,
                                                      span) {
                     Ok(bound) => bound,
-                    Err(ErrorReported) => return (tcx.types.err, ty_path_def),
+                    Err(ErrorReported) => return (tcx.types.err, Def::Err),
                 }
             }
             _ => {
                 self.report_ambiguous_associated_type(span,
                                                       &ty.to_string(),
                                                       "Trait",
                                                       &assoc_name.as_str());
-                return (tcx.types.err, ty_path_def);
+                return (tcx.types.err, Def::Err);
             }
         };
 
@@ -1574,45 +1574,46 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
         }
     }
 
-    // Note that both base_segments and assoc_segments may be empty, although not at
-    // the same time.
+    // Resolve possibly associated type path into a type and final definition.
+    // Note that both base_segments and assoc_segments may be empty, although not at same time.
     pub fn finish_resolving_def_to_ty(&self,
                                       rscope: &RegionScope,
                                       span: Span,
                                       param_mode: PathParamMode,
-                                      mut def: Def,
+                                      base_def: Def,
                                       opt_self_ty: Option<Ty<'tcx>>,
                                       base_path_ref_id: ast::NodeId,
                                       base_segments: &[hir::PathSegment],
                                       assoc_segments: &[hir::PathSegment])
                                       -> (Ty<'tcx>, Def) {
-        debug!("finish_resolving_def_to_ty(def={:?}, \
+        // Convert the base type.
+        debug!("finish_resolving_def_to_ty(base_def={:?}, \
                 base_segments={:?}, \
                 assoc_segments={:?})",
-               def,
+               base_def,
                base_segments,
                assoc_segments);
-        let mut ty = self.base_def_to_ty(rscope,
-                                         span,
-                                         param_mode,
-                                         def,
-                                         opt_self_ty,
-                                         base_path_ref_id,
-                                         base_segments);
-        debug!("finish_resolving_def_to_ty: base_def_to_ty returned {:?}", ty);
+        let base_ty = self.base_def_to_ty(rscope,
+                                          span,
+                                          param_mode,
+                                          base_def,
+                                          opt_self_ty,
+                                          base_path_ref_id,
+                                          base_segments);
+        debug!("finish_resolving_def_to_ty: base_def_to_ty returned {:?}", base_ty);
+
         // If any associated type segments remain, attempt to resolve them.
+        let (mut ty, mut def) = (base_ty, base_def);
         for segment in assoc_segments {
             debug!("finish_resolving_def_to_ty: segment={:?}", segment);
-            if ty.sty == ty::TyError {
+            // This is pretty bad (it will fail except for T::A and Self::A).
+            let (new_ty, new_def) = self.associated_path_def_to_ty(span, ty, def, segment);
+            ty = new_ty;
+            def = new_def;
+
+            if def == Def::Err {
                 break;
             }
-            // This is pretty bad (it will fail except for T::A and Self::A).
-            let (a_ty, a_def) = self.associated_path_def_to_ty(span,
-                                                               ty,
-                                                               def,
-                                                               segment);
-            ty = a_ty;
-            def = a_def;
         }
         (ty, def)
     }
@@ -1719,23 +1720,22 @@ impl<'o, 'gcx: 'tcx, 'tcx> AstConv<'gcx, 'tcx>+'o {
             hir::TyPath(ref maybe_qself, ref path) => {
                 debug!("ast_ty_to_ty: maybe_qself={:?} path={:?}", maybe_qself, path);
                 let path_res = tcx.expect_resolution(ast_ty.id);
-                let def = path_res.base_def;
                 let base_ty_end = path.segments.len() - path_res.depth;
                 let opt_self_ty = maybe_qself.as_ref().map(|qself| {
                     self.ast_ty_to_ty(rscope, &qself.ty)
                 });
-                let (ty, _def) = self.finish_resolving_def_to_ty(rscope,
-                                                                 ast_ty.span,
-                                                                 PathParamMode::Explicit,
-                                                                 def,
-                                                                 opt_self_ty,
-                                                                 ast_ty.id,
-                                                                 &path.segments[..base_ty_end],
-                                                                 &path.segments[base_ty_end..]);
-
-                if path_res.depth != 0 && ty.sty != ty::TyError {
-                    // Write back the new resolution.
-                    tcx.def_map.borrow_mut().insert(ast_ty.id, def::PathResolution::new(def));
+                let (ty, def) = self.finish_resolving_def_to_ty(rscope,
+                                                                ast_ty.span,
+                                                                PathParamMode::Explicit,
+                                                                path_res.base_def,
+                                                                opt_self_ty,
+                                                                ast_ty.id,
+                                                                &path.segments[..base_ty_end],
+                                                                &path.segments[base_ty_end..]);
+
+                // Write back the new resolution.
+                if path_res.depth != 0 {
+                    tcx.def_map.borrow_mut().insert(ast_ty.id, PathResolution::new(def));
                 }
 
                 ty