Auto merge of #38014 - jseyfried:refactor_path_resolution, r=nrc

resolve: refactor path resolution

This is a pure refactoring, modulo minor diagnostics improvements.
r? @nrc

Author: bors

src/librustc/hir/lowering.rs

@@ -82,14 +82,11 @@ pub struct LoweringContext<'a> {
 
 pub trait Resolver {
     // Resolve a global hir path generated by the lowerer when expanding `for`, `if let`, etc.
-    fn resolve_generated_global_path(&mut self, path: &mut hir::Path, is_value: bool);
+    fn resolve_hir_path(&mut self, path: &mut hir::Path, is_value: bool);
 
     // Obtain the resolution for a node id
     fn get_resolution(&mut self, id: NodeId) -> Option<PathResolution>;
 
-    // Record the resolution of a path or binding generated by the lowerer when expanding.
-    fn record_resolution(&mut self, id: NodeId, def: Def);
-
     // We must keep the set of definitions up to date as we add nodes that weren't in the AST.
     // This should only return `None` during testing.
     fn definitions(&mut self) -> &mut Definitions;
@@ -372,12 +369,7 @@ impl<'a> LoweringContext<'a> {
             // Otherwise, the base path is an implicit `Self` type path,
             // e.g. `Vec` in `Vec::new` or `<I as Iterator>::Item` in
             // `<I as Iterator>::Item::default`.
-            let ty = self.ty(p.span, hir::TyPath(hir::QPath::Resolved(qself, path)));
-
-            // Associate that innermost path type with the base Def.
-            self.resolver.record_resolution(ty.id, resolution.base_def);
-
-            ty
+            self.ty(p.span, hir::TyPath(hir::QPath::Resolved(qself, path)))
         };
 
         // Anything after the base path are associated "extensions",
@@ -1979,10 +1971,8 @@ impl<'a> LoweringContext<'a> {
             def: def,
             segments: hir_vec![hir::PathSegment::from_name(id)],
         })));
-        let expr = self.expr(span, expr_path, ThinVec::new());
-        self.resolver.record_resolution(expr.id, def);
 
-        expr
+        self.expr(span, expr_path, ThinVec::new())
     }
 
     fn expr_mut_addr_of(&mut self, span: Span, e: P<hir::Expr>) -> hir::Expr {
@@ -1995,10 +1985,7 @@ impl<'a> LoweringContext<'a> {
                      attrs: ThinVec<Attribute>)
                      -> hir::Expr {
         let path = self.std_path(span, components, true);
-        let def = path.def;
-        let expr = self.expr(span, hir::ExprPath(hir::QPath::Resolved(None, P(path))), attrs);
-        self.resolver.record_resolution(expr.id, def);
-        expr
+        self.expr(span, hir::ExprPath(hir::QPath::Resolved(None, P(path))), attrs)
     }
 
     fn expr_match(&mut self,
@@ -2025,11 +2012,8 @@ impl<'a> LoweringContext<'a> {
                        e: Option<P<hir::Expr>>,
                        attrs: ThinVec<Attribute>) -> hir::Expr {
         let path = self.std_path(span, components, false);
-        let def = path.def;
         let qpath = hir::QPath::Resolved(None, P(path));
-        let expr = self.expr(span, hir::ExprStruct(qpath, fields, e), attrs);
-        self.resolver.record_resolution(expr.id, def);
-        expr
+        self.expr(span, hir::ExprStruct(qpath, fields, e), attrs)
     }
 
     fn expr(&mut self, span: Span, node: hir::Expr_, attrs: ThinVec<Attribute>) -> hir::Expr {
@@ -2098,16 +2082,13 @@ impl<'a> LoweringContext<'a> {
                     subpats: hir::HirVec<P<hir::Pat>>)
                     -> P<hir::Pat> {
         let path = self.std_path(span, components, true);
-        let def = path.def;
         let qpath = hir::QPath::Resolved(None, P(path));
         let pt = if subpats.is_empty() {
             hir::PatKind::Path(qpath)
         } else {
             hir::PatKind::TupleStruct(qpath, subpats, None)
         };
-        let pat = self.pat(span, pt);
-        self.resolver.record_resolution(pat.id, def);
-        pat
+        self.pat(span, pt)
     }
 
     fn pat_ident(&mut self, span: Span, name: Name) -> P<hir::Pat> {
@@ -2124,7 +2105,6 @@ impl<'a> LoweringContext<'a> {
             let def_index = defs.create_def_with_parent(parent_def, id, def_path_data);
             DefId::local(def_index)
         };
-        self.resolver.record_resolution(id, Def::Local(def_id));
 
         P(hir::Pat {
             id: id,
@@ -2168,7 +2148,7 @@ impl<'a> LoweringContext<'a> {
             segments: segments.into(),
         };
 
-        self.resolver.resolve_generated_global_path(&mut path, is_value);
+        self.resolver.resolve_hir_path(&mut path, is_value);
         path
     }
 

src/librustc_driver/driver.rs

@@ -10,7 +10,6 @@
 
 use rustc::hir;
 use rustc::hir::{map as hir_map, FreevarMap, TraitMap};
-use rustc::hir::def::DefMap;
 use rustc::hir::lowering::lower_crate;
 use rustc_data_structures::blake2b::Blake2bHasher;
 use rustc_data_structures::fmt_wrap::FmtWrap;
@@ -63,7 +62,6 @@ use derive_registrar;
 
 #[derive(Clone)]
 pub struct Resolutions {
-    pub def_map: DefMap,
     pub freevars: FreevarMap,
     pub trait_map: TraitMap,
     pub maybe_unused_trait_imports: NodeSet,
@@ -794,7 +792,6 @@ pub fn phase_2_configure_and_expand<F>(sess: &Session,
             hir_ty_to_ty: NodeMap(),
         },
         resolutions: Resolutions {
-            def_map: resolver.def_map,
             freevars: resolver.freevars,
             trait_map: resolver.trait_map,
             maybe_unused_trait_imports: resolver.maybe_unused_trait_imports,

src/librustc_resolve/build_reduced_graph.rs

@@ -18,7 +18,6 @@ use resolve_imports::ImportDirective;
 use resolve_imports::ImportDirectiveSubclass::{self, GlobImport, SingleImport};
 use {Resolver, Module, ModuleS, ModuleKind, NameBinding, NameBindingKind, ToNameBinding};
 use Namespace::{self, TypeNS, ValueNS, MacroNS};
-use ResolveResult::Success;
 use {resolve_error, resolve_struct_error, ResolutionError};
 
 use rustc::middle::cstore::LoadedMacro;
@@ -583,7 +582,7 @@ impl<'b> Resolver<'b> {
         } else {
             for (name, span) in legacy_imports.imports {
                 let result = self.resolve_name_in_module(module, name, MacroNS, false, None);
-                if let Success(binding) = result {
+                if let Ok(binding) = result {
                     self.legacy_import_macro(name, binding, span, allow_shadowing);
                 } else {
                     span_err!(self.session, span, E0469, "imported macro not found");
@@ -595,7 +594,7 @@ impl<'b> Resolver<'b> {
             self.used_crates.insert(krate);
             self.session.cstore.export_macros(krate);
             let result = self.resolve_name_in_module(module, name, MacroNS, false, None);
-            if let Success(binding) = result {
+            if let Ok(binding) = result {
                 self.macro_exports.push(Export { name: name, def: binding.def() });
             } else {
                 span_err!(self.session, span, E0470, "reexported macro not found");