3 files changed, 24 insertions, 5 deletions
diff --git a/library/proc_macro/src/bridge/mod.rs b/library/proc_macro/src/bridge/mod.rs
index c898d483a8b..355ad1f9f88 100644
--- a/library/proc_macro/src/bridge/mod.rs
+++ b/library/proc_macro/src/bridge/mod.rs
@@ -162,6 +162,8 @@ macro_rules! with_api {
                 fn join($self: $S::Span, other: $S::Span) -> Option<$S::Span>;
                 fn resolved_at($self: $S::Span, at: $S::Span) -> $S::Span;
                 fn source_text($self: $S::Span) -> Option<String>;
+                fn save_span($self: $S::Span) -> usize;
+                fn recover_proc_macro_span(id: usize) -> $S::Span;
             },
         }
     };
@@ -338,6 +340,7 @@ mark_noop! {
     &'a [u8],
     &'a str,
     String,
+    usize,
     Delimiter,
     Level,
     LineColumn,
diff --git a/library/proc_macro/src/lib.rs b/library/proc_macro/src/lib.rs
index c7f58f36154..525fd0fbe34 100644
--- a/library/proc_macro/src/lib.rs
+++ b/library/proc_macro/src/lib.rs
@@ -265,7 +265,7 @@ pub mod token_stream {
 /// Unquoting is done with `$`, and works by taking the single next ident as the unquoted term.
 /// To quote `$` itself, use `$$`.
 #[unstable(feature = "proc_macro_quote", issue = "54722")]
-#[allow_internal_unstable(proc_macro_def_site)]
+#[allow_internal_unstable(proc_macro_def_site, proc_macro_internals)]
 #[rustc_builtin_macro]
 pub macro quote($($t:tt)*) {
     /* compiler built-in */
@@ -394,6 +394,20 @@ impl Span {
         self.0.source_text()
     }
 
+    // Used by the implementation of `Span::quote`
+    #[doc(hidden)]
+    #[unstable(feature = "proc_macro_internals", issue = "27812")]
+    pub fn save_span(&self) -> usize {
+        self.0.save_span()
+    }
+
+    // Used by the implementation of `Span::quote`
+    #[doc(hidden)]
+    #[unstable(feature = "proc_macro_internals", issue = "27812")]
+    pub fn recover_proc_macro_span(id: usize) -> Span {
+        Span(bridge::client::Span::recover_proc_macro_span(id))
+    }
+
     diagnostic_method!(error, Level::Error);
     diagnostic_method!(warning, Level::Warning);
     diagnostic_method!(note, Level::Note);
diff --git a/library/proc_macro/src/quote.rs b/library/proc_macro/src/quote.rs
index 144e2d6bac4..1fd59889709 100644
--- a/library/proc_macro/src/quote.rs
+++ b/library/proc_macro/src/quote.rs
@@ -65,6 +65,7 @@ pub fn quote(stream: TokenStream) -> TokenStream {
     if stream.is_empty() {
         return quote!(crate::TokenStream::new());
     }
+    let proc_macro_crate = quote!(crate);
     let mut after_dollar = false;
     let tokens = stream
         .into_iter()
@@ -105,7 +106,7 @@ pub fn quote(stream: TokenStream) -> TokenStream {
                 ))),
                 TokenTree::Ident(tt) => quote!(crate::TokenTree::Ident(crate::Ident::new(
                     (@ TokenTree::from(Literal::string(&tt.to_string()))),
-                    (@ quote_span(tt.span())),
+                    (@ quote_span(proc_macro_crate.clone(), tt.span())),
                 ))),
                 TokenTree::Literal(tt) => quote!(crate::TokenTree::Literal({
                     let mut iter = (@ TokenTree::from(Literal::string(&tt.to_string())))
@@ -115,7 +116,7 @@ pub fn quote(stream: TokenStream) -> TokenStream {
                     if let (Some(crate::TokenTree::Literal(mut lit)), None) =
                         (iter.next(), iter.next())
                     {
-                        lit.set_span((@ quote_span(tt.span())));
+                        lit.set_span((@ quote_span(proc_macro_crate.clone(), tt.span())));
                         lit
                     } else {
                         unreachable!()
@@ -135,6 +136,7 @@ pub fn quote(stream: TokenStream) -> TokenStream {
 /// Quote a `Span` into a `TokenStream`.
 /// This is needed to implement a custom quoter.
 #[unstable(feature = "proc_macro_quote", issue = "54722")]
-pub fn quote_span(_: Span) -> TokenStream {
-    quote!(crate::Span::def_site())
+pub fn quote_span(proc_macro_crate: TokenStream, span: Span) -> TokenStream {
+    let id = span.save_span();
+    quote!((@ proc_macro_crate ) ::Span::recover_proc_macro_span((@ TokenTree::from(Literal::usize_unsuffixed(id)))))
 }