proc_macro: Add `Span::mixed_site` exposing `macro_rules` hygiene

2 files changed, 11 insertions, 0 deletions

diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 54cfb80573e..583fb3f7701 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -953,6 +953,12 @@ impl<'a> ExtCtxt<'a> {
         span.with_call_site_ctxt(self.current_expansion.id)
     }
 
+    /// Equivalent of `Span::mixed_site` from the proc macro API,
+    /// except that the location is taken from the span passed as an argument.
+    pub fn with_mixed_site_ctxt(&self, span: Span) -> Span {
+        span.with_mixed_site_ctxt(self.current_expansion.id)
+    }
+
     /// Returns span for the macro which originally caused the current expansion to happen.
     ///
     /// Stops backtracing at include! boundary.
diff --git a/src/libsyntax/ext/proc_macro_server.rs b/src/libsyntax/ext/proc_macro_server.rs
index dfec9ee2880..021ec46d987 100644
--- a/src/libsyntax/ext/proc_macro_server.rs
+++ b/src/libsyntax/ext/proc_macro_server.rs
@@ -355,6 +355,7 @@ pub(crate) struct Rustc<'a> {
     sess: &'a ParseSess,
     def_site: Span,
     call_site: Span,
+    mixed_site: Span,
 }
 
 impl<'a> Rustc<'a> {
@@ -364,6 +365,7 @@ impl<'a> Rustc<'a> {
             sess: cx.parse_sess,
             def_site: cx.with_def_site_ctxt(expn_data.def_site),
             call_site: cx.with_call_site_ctxt(expn_data.call_site),
+            mixed_site: cx.with_mixed_site_ctxt(expn_data.call_site),
         }
     }
 
@@ -664,6 +666,9 @@ impl server::Span for Rustc<'_> {
     fn call_site(&mut self) -> Self::Span {
         self.call_site
     }
+    fn mixed_site(&mut self) -> Self::Span {
+        self.mixed_site
+    }
     fn source_file(&mut self, span: Self::Span) -> Self::SourceFile {
         self.sess.source_map().lookup_char_pos(span.lo()).file
     }