Fix handling of arguments of #[pin_project] attribute

Author: taiki-e

pin-project-internal/src/pin_project/mod.rs

@@ -37,6 +37,10 @@ impl Parse for Args {
                 "UnsafeUnpin" => unsafe_unpin = Some(i.span()),
                 _ => return Err(error!(i, "an invalid argument was passed")),
             }
+
+            if !input.is_empty() {
+                let _: Comma = input.parse()?;
+            }
         }
         Ok(Self { pinned_drop, unsafe_unpin })
     }

tests/pin_project.rs

@@ -4,7 +4,7 @@
 #![allow(dead_code)]
 
 use core::pin::Pin;
-use pin_project::pin_project;
+use pin_project::{pin_project, pinned_drop, UnsafeUnpin};
 
 #[test]
 fn test_pin_project() {
@@ -164,3 +164,19 @@ fn overlapping_lifetime_names() {
         field: &'_pin mut T,
     }
 }
+
+#[test]
+fn combine() {
+    #[pin_project(PinnedDrop, UnsafeUnpin)]
+    pub struct Foo<T> {
+        field_1: u8,
+        #[pin]
+        field_2: T,
+    }
+
+    #[pinned_drop]
+    fn do_drop<T>(_: Pin<&mut Foo<T>>) {}
+
+    #[allow(unsafe_code)]
+    unsafe impl<T: Unpin> UnsafeUnpin for Foo<T> {}
+}

tests/ui/pin_project/invalid.rs

@@ -26,4 +26,10 @@ enum D<T> {
     },
 }
 
+#[pin_project(UnsafeUnpin,,)] //~ ERROR unexpected token
+struct E<T> {
+    #[pin]
+    future: T,
+}
+
 fn main() {}

tests/ui/pin_project/invalid.stderr

@@ -22,5 +22,11 @@ error: unexpected token
 24 |         #[pin(foo)] //~ ERROR unexpected token
    |              ^
 
-error: aborting due to 4 previous errors
+error: expected identifier
+  --> $DIR/invalid.rs:29:27
+   |
+29 | #[pin_project(UnsafeUnpin,,)] //~ ERROR unexpected token
+   |                           ^
+
+error: aborting due to 5 previous errors