Track distinct spans for open and close delimiter

2 files changed, 12 insertions, 26 deletions

diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
index 8ed7b8f52ba..d4737052875 100644
--- a/src/libproc_macro/lib.rs
+++ b/src/libproc_macro/lib.rs
@@ -63,8 +63,8 @@ use std::str::FromStr;
 use syntax::errors::DiagnosticBuilder;
 use syntax::parse::{self, token};
 use syntax::symbol::Symbol;
-use syntax::tokenstream;
-use syntax_pos::{BytePos, Pos, FileName};
+use syntax::tokenstream::{self, DelimSpan};
+use syntax_pos::{Pos, FileName};
 
 /// The main type provided by this crate, representing an abstract stream of
 /// tokens, or, more specifically, a sequence of token trees.
@@ -609,7 +609,7 @@ impl fmt::Display for TokenTree {
 pub struct Group {
     delimiter: Delimiter,
     stream: TokenStream,
-    span: Span,
+    span: DelimSpan,
 }
 
 #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
@@ -650,7 +650,7 @@ impl Group {
         Group {
             delimiter: delimiter,
             stream: stream,
-            span: Span::call_site(),
+            span: DelimSpan::from_single(Span::call_site().0),
         }
     }
 
@@ -678,11 +678,10 @@ impl Group {
     /// ```
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn span(&self) -> Span {
-        self.span
+        Span(self.span.entire())
     }
 
-    /// Returns the span pointing to the opening delimiter of this group, or the
-    /// span of the entire group if this is a None-delimited group.
+    /// Returns the span pointing to the opening delimiter of this group.
     ///
     /// ```text
     /// pub fn span_open(&self) -> Span {
@@ -690,17 +689,10 @@ impl Group {
     /// ```
     #[unstable(feature = "proc_macro_span", issue = "38356")]
     pub fn span_open(&self) -> Span {
-        if self.delimiter == Delimiter::None {
-            self.span
-        } else {
-            let lo = self.span.0.lo();
-            let new_hi = BytePos::from_usize(lo.to_usize() + 1);
-            Span(self.span.0.with_hi(new_hi))
-        }
+        Span(self.span.open)
     }
 
-    /// Returns the span pointing to the closing delimiter of this group, or the
-    /// span of the entire group if this is a None-delimited group.
+    /// Returns the span pointing to the closing delimiter of this group.
     ///
     /// ```text
     /// pub fn span_close(&self) -> Span {
@@ -708,13 +700,7 @@ impl Group {
     /// ```
     #[unstable(feature = "proc_macro_span", issue = "38356")]
     pub fn span_close(&self) -> Span {
-        let hi = self.span.0.hi();
-        if self.delimiter == Delimiter::None || hi.to_usize() == 0 {
-            self.span
-        } else {
-            let new_lo = BytePos::from_usize(hi.to_usize() - 1);
-            Span(self.span.0.with_lo(new_lo))
-        }
+        Span(self.span.close)
     }
 
     /// Configures the span for this `Group`'s delimiters, but not its internal
@@ -725,7 +711,7 @@ impl Group {
     /// tokens at the level of the `Group`.
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn set_span(&mut self, span: Span) {
-        self.span = span;
+        self.span = DelimSpan::from_single(span.0);
     }
 }
 
diff --git a/src/libproc_macro/rustc.rs b/src/libproc_macro/rustc.rs
index 21229d3299d..3ce02d1afb1 100644
--- a/src/libproc_macro/rustc.rs
+++ b/src/libproc_macro/rustc.rs
@@ -64,7 +64,7 @@ impl TokenTree {
             tokenstream::TokenTree::Delimited(span, delimed) => {
                 let delimiter = Delimiter::from_internal(delimed.delim);
                 let mut g = Group::new(delimiter, ::TokenStream(delimed.tts.into()));
-                g.set_span(Span(span));
+                g.span = span;
                 return g.into();
             }
         };
@@ -192,7 +192,7 @@ impl TokenTree {
             self::TokenTree::Punct(tt) => (tt.as_char(), tt.spacing(), tt.span()),
             self::TokenTree::Group(tt) => {
                 return TokenTree::Delimited(
-                    tt.span.0,
+                    tt.span,
                     Delimited {
                         delim: tt.delimiter.to_internal(),
                         tts: tt.stream.0.into(),