resolve: Cleanup resolve_crate_root

Author: petrochenkov

src/librustc_resolve/build_reduced_graph.rs

@@ -156,7 +156,7 @@ impl<'a> Resolver<'a> {
 
                     // Disallow `use $crate;`
                     if source.name == keywords::DollarCrate.name() && path.segments.len() == 1 {
-                        let crate_root = self.resolve_crate_root(source.span.ctxt(), true);
+                        let crate_root = self.resolve_crate_root(source);
                         let crate_name = match crate_root.kind {
                             ModuleKind::Def(_, name) => name,
                             ModuleKind::Block(..) => unreachable!(),

src/librustc_resolve/lib.rs

@@ -1981,8 +1981,9 @@ impl<'a> Resolver<'a> {
         result
     }
 
-    fn resolve_crate_root(&mut self, mut ctxt: SyntaxContext, legacy: bool) -> Module<'a> {
-        let mark = if legacy {
+    fn resolve_crate_root(&mut self, ident: Ident) -> Module<'a> {
+        let mut ctxt = ident.span.ctxt();
+        let mark = if ident.name == keywords::DollarCrate.name() {
             // When resolving `$crate` from a `macro_rules!` invoked in a `macro`,
             // we don't want to pretend that the `macro_rules!` definition is in the `macro`
             // as described in `SyntaxContext::apply_mark`, so we ignore prepended modern marks.
@@ -3345,14 +3346,11 @@ impl<'a> Resolver<'a> {
             if ns == TypeNS {
                 if (i == 0 && name == keywords::CrateRoot.name()) ||
                    (i == 0 && name == keywords::Crate.name()) ||
+                   (i == 0 && name == keywords::DollarCrate.name()) ||
                    (i == 1 && name == keywords::Crate.name() &&
                               path[0].name == keywords::CrateRoot.name()) {
-                    // `::a::b` or `::crate::a::b`
-                    module = Some(self.resolve_crate_root(ident.span.ctxt(), false));
-                    continue
-                } else if i == 0 && name == keywords::DollarCrate.name() {
-                    // `$crate::a::b`
-                    module = Some(self.resolve_crate_root(ident.span.ctxt(), true));
+                    // `::a::b`, `crate::a::b`, `::crate::a::b` or `$crate::a::b`
+                    module = Some(self.resolve_crate_root(ident));
                     continue
                 } else if i == 1 && !ident.is_path_segment_keyword() {
                     let prev_name = path[0].name;

src/librustc_resolve/macros.rs

@@ -155,10 +155,9 @@ impl<'a> base::Resolver for Resolver<'a> {
                     }
                 });
 
-                let ident = path.segments[0].ident;
-                if ident.name == keywords::DollarCrate.name() {
+                if path.segments[0].ident.name == keywords::DollarCrate.name() {
+                    let module = self.0.resolve_crate_root(path.segments[0].ident);
                     path.segments[0].ident.name = keywords::CrateRoot.name();
-                    let module = self.0.resolve_crate_root(ident.span.ctxt(), true);
                     if !module.is_local() {
                         let span = path.segments[0].ident.span;
                         path.segments.insert(1, match module.kind {

src/librustc_resolve/resolve_imports.rs

@@ -698,7 +698,7 @@ impl<'a, 'b:'a> ImportResolver<'a, 'b> {
                                          "crate root imports need to be explicitly named: \
                                           `use crate as name;`".to_string()));
                         } else {
-                            Some(self.resolve_crate_root(source.span.ctxt().modern(), false))
+                            Some(self.resolve_crate_root(source))
                         }
                     } else if is_extern && !source.is_path_segment_keyword() {
                         let crate_id =