diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index abc8b83144941..a642491b28181 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -26,9 +26,10 @@ use rustc::ty::{self, DefIdTree, TyCtxt, Region, RegionVid, Ty, AdtKind};
 use rustc::ty::fold::TypeFolder;
 use rustc::ty::layout::VariantIdx;
 use rustc::util::nodemap::{FxHashMap, FxHashSet};
-use syntax::ast::{self, AttrStyle, Ident};
+use syntax::ast::{self, Attribute, AttrStyle, AttrItem, Ident};
 use syntax::attr;
 use syntax_expand::base::MacroKind;
+use syntax::parse::lexer::comments;
 use syntax::source_map::DUMMY_SP;
 use syntax::symbol::{Symbol, kw, sym};
 use syntax_pos::{self, Pos, FileName};
@@ -858,8 +859,31 @@ impl Attributes {
         let mut cfg = Cfg::True;
         let mut doc_line = 0;
 
+        /// Converts `attr` to a normal `#[doc="foo"]` comment, if it is a
+        /// comment like `///` or `/** */`. (Returns `attr` unchanged for
+        /// non-sugared doc attributes.)
+        pub fn with_desugared_doc<T>(attr: &Attribute, f: impl FnOnce(&Attribute) -> T) -> T {
+            if attr.is_sugared_doc {
+                let comment = attr.value_str().unwrap();
+                let meta = attr::mk_name_value_item_str(
+                    Ident::with_dummy_span(sym::doc),
+                    Symbol::intern(&comments::strip_doc_comment_decoration(&comment.as_str())),
+                    DUMMY_SP,
+                );
+                f(&Attribute {
+                    item: AttrItem { path: meta.path, tokens: meta.kind.tokens(meta.span) },
+                    id: attr.id,
+                    style: attr.style,
+                    is_sugared_doc: true,
+                    span: attr.span,
+                })
+            } else {
+                f(attr)
+            }
+        }
+
         let other_attrs = attrs.iter().filter_map(|attr| {
-            attr.with_desugared_doc(|attr| {
+            with_desugared_doc(attr, |attr| {
                 if attr.check_name(sym::doc) {
                     if let Some(mi) = attr.meta() {
                         if let Some(value) = mi.value_str() {
diff --git a/src/libsyntax/attr/mod.rs b/src/libsyntax/attr/mod.rs
index 4aec50408812f..27de084ae98ca 100644
--- a/src/libsyntax/attr/mod.rs
+++ b/src/libsyntax/attr/mod.rs
@@ -13,8 +13,8 @@ use crate::ast::{AttrItem, AttrId, AttrStyle, Name, Ident, Path, PathSegment};
 use crate::ast::{MetaItem, MetaItemKind, NestedMetaItem};
 use crate::ast::{Lit, LitKind, Expr, Item, Local, Stmt, StmtKind, GenericParam};
 use crate::mut_visit::visit_clobber;
-use crate::source_map::{BytePos, Spanned, DUMMY_SP};
-use crate::parse::lexer::comments::{doc_comment_style, strip_doc_comment_decoration};
+use crate::source_map::{BytePos, Spanned};
+use crate::parse::lexer::comments::doc_comment_style;
 use crate::parse::parser::Parser;
 use crate::parse::PResult;
 use crate::parse::token::{self, Token};
@@ -312,31 +312,6 @@ impl Attribute {
             span: self.span,
         })
     }
-
-    /// Converts `self` to a normal `#[doc="foo"]` comment, if it is a
-    /// comment like `///` or `/** */`. (Returns `self` unchanged for
-    /// non-sugared doc attributes.)
-    pub fn with_desugared_doc<T, F>(&self, f: F) -> T where
-        F: FnOnce(&Attribute) -> T,
-    {
-        if self.is_sugared_doc {
-            let comment = self.value_str().unwrap();
-            let meta = mk_name_value_item_str(
-                Ident::with_dummy_span(sym::doc),
-                Symbol::intern(&strip_doc_comment_decoration(&comment.as_str())),
-                DUMMY_SP,
-            );
-            f(&Attribute {
-                item: AttrItem { path: meta.path, tokens: meta.kind.tokens(meta.span) },
-                id: self.id,
-                style: self.style,
-                is_sugared_doc: true,
-                span: self.span,
-            })
-        } else {
-            f(self)
-        }
-    }
 }
 
 /* Constructors */
diff --git a/src/libsyntax/parse/lexer/comments.rs b/src/libsyntax/parse/lexer/comments.rs
index 5121a9ef7b5fc..ac79ce323bf97 100644
--- a/src/libsyntax/parse/lexer/comments.rs
+++ b/src/libsyntax/parse/lexer/comments.rs
@@ -176,7 +176,7 @@ fn split_block_comment_into_lines(
 
 // it appears this function is called only from pprust... that's
 // probably not a good thing.
-pub fn gather_comments(sess: &ParseSess, path: FileName, src: String) -> Vec<Comment> {
+crate fn gather_comments(sess: &ParseSess, path: FileName, src: String) -> Vec<Comment> {
     let cm = SourceMap::new(sess.source_map().path_mapping().clone());
     let source_file = cm.new_source_file(path, src);
     let text = (*source_file.src.as_ref().unwrap()).clone();
diff --git a/src/libsyntax/parse/lexer/tokentrees.rs b/src/libsyntax/parse/lexer/tokentrees.rs
index b4dd23c9f9b0f..853723de14f44 100644
--- a/src/libsyntax/parse/lexer/tokentrees.rs
+++ b/src/libsyntax/parse/lexer/tokentrees.rs
@@ -1,8 +1,9 @@
 use rustc_data_structures::fx::FxHashMap;
 use syntax_pos::Span;
 
+use super::{StringReader, UnmatchedBrace};
+
 use crate::print::pprust::token_to_string;
-use crate::parse::lexer::{StringReader, UnmatchedBrace};
 use crate::parse::token::{self, Token};
 use crate::parse::PResult;
 use crate::tokenstream::{DelimSpan, IsJoint::{self, *}, TokenStream, TokenTree, TreeAndJoint};