Enable parsing of attributes inside a match block

We allow invalid inner attributes to be parsed, e.g. inner attributes that are
not directly after the opening brace of the match block.

Instead we run validation on `MatchArmList` to allow better reporting of errors.

1 files changed, 28 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/validation/match_armlist.rs b/crates/ra_syntax/src/validation/match_armlist.rs
new file mode 100644
index 000000000..c43ed7092
--- /dev/null
+++ b/crates/ra_syntax/src/validation/match_armlist.rs
@@ -0,0 +1,28 @@
+use crate::{

+    ast::{self, AttrsOwner, AstNode},

+    syntax_node::{

+        SyntaxError,

+        SyntaxErrorKind::*,

+        Direction,

+    },

+};

+

+pub(crate) fn validate_match_armlist(node: &ast::MatchArmList, errors: &mut Vec<SyntaxError>) {

+    // Report errors for any inner attribute

+    // which has a preceding matcharm or an outer attribute

+    for inner_attr in node.attrs().filter(|s| s.is_inner()) {

+        let any_errors = inner_attr.syntax().siblings(Direction::Prev).any(|s| {

+            match (ast::MatchArm::cast(s), ast::Attr::cast(s)) {

+                (Some(_), _) => true,

+                // Outer attributes which preceed an inner attribute are not allowed

+                (_, Some(a)) if !a.is_inner() => true,

+                (_, Some(_)) => false,

+                (None, None) => false,

+            }

+        });

+

+        if any_errors {

+            errors.push(SyntaxError::new(InvalidMatchInnerAttr, inner_attr.syntax().range()));

+        }

+    }

+}