Merge pull request dtolnay#150 from dtolnay/marker

Remove Send and Sync from SourceFile

Author: dtolnay

src/lib.rs

@@ -220,10 +220,20 @@ pub use imp::FileName;
 /// This type is semver exempt and not exposed by default.
 #[cfg(procmacro2_semver_exempt)]
 #[derive(Clone, PartialEq, Eq)]
-pub struct SourceFile(imp::SourceFile);
+pub struct SourceFile {
+    inner: imp::SourceFile,
+    _marker: marker::PhantomData<Rc<()>>,
+}
 
 #[cfg(procmacro2_semver_exempt)]
 impl SourceFile {
+    fn _new(inner: imp::SourceFile) -> Self {
+        SourceFile {
+            inner: inner,
+            _marker: marker::PhantomData,
+        }
+    }
+
     /// Get the path to this source file.
     ///
     /// ### Note
@@ -238,27 +248,27 @@ impl SourceFile {
     ///
     /// [`is_real`]: #method.is_real
     pub fn path(&self) -> &FileName {
-        self.0.path()
+        self.inner.path()
     }
 
     /// Returns `true` if this source file is a real source file, and not
     /// generated by an external macro's expansion.
     pub fn is_real(&self) -> bool {
-        self.0.is_real()
+        self.inner.is_real()
     }
 }
 
 #[cfg(procmacro2_semver_exempt)]
 impl AsRef<FileName> for SourceFile {
     fn as_ref(&self) -> &FileName {
-        self.0.path()
+        self.inner.path()
     }
 }
 
 #[cfg(procmacro2_semver_exempt)]
 impl fmt::Debug for SourceFile {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        self.0.fmt(f)
+        self.inner.fmt(f)
     }
 }
 
@@ -344,7 +354,7 @@ impl Span {
     /// This method is semver exempt and not exposed by default.
     #[cfg(procmacro2_semver_exempt)]
     pub fn source_file(&self) -> SourceFile {
-        SourceFile(self.inner.source_file())
+        SourceFile::_new(self.inner.source_file())
     }
 
     /// Get the starting line/column in the source file for this span.

tests/marker.rs

@@ -0,0 +1,61 @@
+extern crate proc_macro2;
+
+use proc_macro2::*;
+
+macro_rules! assert_impl {
+    ($ty:ident is $($marker:ident) and +) => {
+        #[test]
+        #[allow(non_snake_case)]
+        fn $ty() {
+            fn assert_implemented<T: $($marker +)+>() {}
+            assert_implemented::<$ty>();
+        }
+    };
+
+    ($ty:ident is not $($marker:ident) or +) => {
+        #[test]
+        #[allow(non_snake_case)]
+        fn $ty() {
+            $(
+                {
+                    // Implemented for types that implement $marker.
+                    trait IsNotImplemented {
+                        fn assert_not_implemented() {}
+                    }
+                    impl<T: $marker> IsNotImplemented for T {}
+
+                    // Implemented for the type being tested.
+                    trait IsImplemented {
+                        fn assert_not_implemented() {}
+                    }
+                    impl IsImplemented for $ty {}
+
+                    // If $ty does not implement $marker, there is no ambiguity
+                    // in the following trait method call.
+                    <$ty>::assert_not_implemented();
+                }
+            )+
+        }
+    };
+}
+
+assert_impl!(Delimiter is Send and Sync);
+assert_impl!(Spacing is Send and Sync);
+
+assert_impl!(Group is not Send or Sync);
+assert_impl!(Ident is not Send or Sync);
+assert_impl!(LexError is not Send or Sync);
+assert_impl!(Literal is not Send or Sync);
+assert_impl!(Punct is not Send or Sync);
+assert_impl!(Span is not Send or Sync);
+assert_impl!(TokenStream is not Send or Sync);
+assert_impl!(TokenTree is not Send or Sync);
+
+#[cfg(procmacro2_semver_exempt)]
+mod semver_exempt {
+    use super::*;
+
+    assert_impl!(LineColumn is Send and Sync);
+
+    assert_impl!(SourceFile is not Send or Sync);
+}