Revise revisions

README.md

@@ -32,7 +32,9 @@ their command specifies, or the test will fail without even being run.
 * `//@error-pattern: XXX` make sure the stderr output contains `XXX`
 * `//@revisions: XXX YYY` runs the test once for each space separated name in the list
     * emits one stderr file per revision
-    * `//~` comments can be restricted to specific revisions by adding the revision name before the `~` in square brackets: `//[XXX]~`
+    * `//~` comments can be restricted to specific revisions by adding the revision name after the `~` in square brackets: `//~[XXX]`
+    * `//@` comments can be restricted to specific revisions by adding the revision name after the `@` in square brackets: `//@[XXX]`
+        * Note that you cannot add revisions to the `revisions` command.
 * `//@compile-flags: XXX` appends `XXX` to the command line arguments passed to the rustc driver
     * you can specify this multiple times, and all the flags will accumulate
 * `//@rustc-env: XXX=YYY` sets the env var `XXX` to `YYY` for the rustc driver execution.

src/lib.rs

@@ -727,11 +727,21 @@ fn check_annotations(
     }
 
     let filter = |msgs: Vec<Message>, errors: &mut Vec<_>| -> Vec<_> {
+        let mut error = |_| {
+            errors.push(Error::InvalidComment {
+                msg: "`require_annotations_for_level` specified twice for same revision".into(),
+                line: 0,
+            })
+        };
         msgs.into_iter()
             .filter(|msg| {
                 msg.level
                     >= comments
-                        .find_one_for_revision(revision, |r| r.require_annotations_for_level, |_| errors.push(Error::InvalidComment { msg: "`require_annotations_for_level` specified twice for same revision".into(), line: 0 }))
+                        .find_one_for_revision(
+                            revision,
+                            |r| r.require_annotations_for_level,
+                            &mut error,
+                        )
                         .unwrap_or(lowest_annotation_level)
             })
             .collect()

src/parser.rs

@@ -247,17 +247,14 @@ impl CommentParser<Comments> {
             }
         };
 
-        match command {
-            "revisions" => {
-                self.check(
-                    revisions.is_empty(),
-                    "cannot declare revisions under a revision",
-                );
-                self.check(self.revisions.is_none(), "cannot specify `revisions` twice");
-                self.revisions = Some(args.split_whitespace().map(|s| s.to_string()).collect());
-                return;
-            }
-            _ => {}
+        if command == "revisions" {
+            self.check(
+                revisions.is_empty(),
+                "cannot declare revisions under a revision",
+            );
+            self.check(self.revisions.is_none(), "cannot specify `revisions` twice");
+            self.revisions = Some(args.split_whitespace().map(|s| s.to_string()).collect());
+            return;
         }
         self.revisioned(revisions, |this| this.parse_command(command, args));
     }