Rollup merge of rust-lang#84763 - tdelabro:shrink-doctree-module, r=jyn514

shrink doctree::Module

helps rust-lang#76382

Author: Dylan-DPC

src/librustdoc/clean/mod.rs

@@ -100,12 +100,13 @@ impl Clean<Item> for doctree::Module<'_> {
         // determine if we should display the inner contents or
         // the outer `mod` item for the source code.
         let span = Span::from_rustc_span({
+            let where_outer = self.where_outer(cx.tcx);
             let sm = cx.sess().source_map();
-            let outer = sm.lookup_char_pos(self.where_outer.lo());
+            let outer = sm.lookup_char_pos(where_outer.lo());
             let inner = sm.lookup_char_pos(self.where_inner.lo());
             if outer.file.start_pos == inner.file.start_pos {
                 // mod foo { ... }
-                self.where_outer
+                where_outer
             } else {
                 // mod foo; (and a separate SourceFile for the contents)
                 self.where_inner

src/librustdoc/doctree.rs

@@ -1,12 +1,12 @@
 //! This module is used to store stuff from Rust's AST in a more convenient
 //! manner (and with prettier names) before cleaning.
+use rustc_middle::ty::TyCtxt;
 use rustc_span::{self, Span, Symbol};
 
 use rustc_hir as hir;
 
 crate struct Module<'hir> {
     crate name: Symbol,
-    crate where_outer: Span,
     crate where_inner: Span,
     crate mods: Vec<Module<'hir>>,
     crate id: hir::HirId,
@@ -17,16 +17,19 @@ crate struct Module<'hir> {
 }
 
 impl Module<'hir> {
-    crate fn new(name: Symbol) -> Module<'hir> {
+    crate fn new(name: Symbol, id: hir::HirId, where_inner: Span) -> Module<'hir> {
         Module {
             name,
-            id: hir::CRATE_HIR_ID,
-            where_outer: rustc_span::DUMMY_SP,
-            where_inner: rustc_span::DUMMY_SP,
+            id,
+            where_inner,
             mods: Vec::new(),
             items: Vec::new(),
             foreigns: Vec::new(),
             macros: Vec::new(),
         }
     }
+
+    crate fn where_outer(&self, tcx: TyCtxt<'_>) -> Span {
+        tcx.hir().span(self.id)
+    }
 }

src/librustdoc/visit_ast.rs

@@ -8,9 +8,9 @@ use rustc_hir::def_id::DefId;
 use rustc_hir::Node;
 use rustc_middle::middle::privacy::AccessLevel;
 use rustc_middle::ty::TyCtxt;
+use rustc_span;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, sym, Symbol};
-use rustc_span::{self, Span};
 
 use std::mem;
 
@@ -73,7 +73,6 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
     crate fn visit(mut self, krate: &'tcx hir::Crate<'_>) -> Module<'tcx> {
         let span = krate.item.inner;
         let mut top_level_module = self.visit_mod_contents(
-            span,
             &Spanned { span, node: hir::VisibilityKind::Public },
             hir::CRATE_HIR_ID,
             &krate.item,
@@ -129,16 +128,12 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
 
     fn visit_mod_contents(
         &mut self,
-        span: Span,
         vis: &hir::Visibility<'_>,
         id: hir::HirId,
         m: &'tcx hir::Mod<'tcx>,
         name: Symbol,
     ) -> Module<'tcx> {
-        let mut om = Module::new(name);
-        om.where_outer = span;
-        om.where_inner = m.inner;
-        om.id = id;
+        let mut om = Module::new(name, id, m.inner);
         // Keep track of if there were any private modules in the path.
         let orig_inside_public_path = self.inside_public_path;
         self.inside_public_path &= vis.node.is_pub();
@@ -312,7 +307,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                 om.items.push((item, renamed))
             }
             hir::ItemKind::Mod(ref m) => {
-                om.mods.push(self.visit_mod_contents(item.span, &item.vis, item.hir_id(), m, name));
+                om.mods.push(self.visit_mod_contents(&item.vis, item.hir_id(), m, name));
             }
             hir::ItemKind::Fn(..)
             | hir::ItemKind::ExternCrate(..)