Allow blocklisting anonymous enums

Note: This will also block anonymous enums with no variants, but
adding a typedef for such an enum should be useless anyway.

Author: jschwe

bindgen-tests/tests/expectations/tests/blocklist-anon-enum.rs

@@ -0,0 +1,7 @@
+// bindgen-flags: --blocklist-item 'SHOULD_BE_BLOCKED.*'
+
+enum {
+    SHOULD_BE_BLOCKED_1,
+    SHOULD_BE_BLOCKED_2,
+    SHOULD_BE_BLOCKED_3
+};

bindgen-tests/tests/expectations/tests/issue-1025-unknown-enum-repr.rs

@@ -2,3 +2,19 @@
 template <typename> class a {
   enum {};
 };
+
+template <typename> class b {
+  enum {
+    SOME_VARIANT
+  };
+};
+
+template <typename> class c {
+  enum my_enum {
+    MY_ENUM_SOME_VARIANT
+  };
+};
+
+template <typename> class d {
+  enum no_variant_enum {};
+};

bindgen-tests/tests/headers/blocklist-anon-enum.hpp

@@ -3654,6 +3654,18 @@ impl CodeGenerator for Enum {
         let layout = enum_ty.layout(ctx);
         let variation = self.computed_enum_variation(ctx, item);
 
+        // blocklist anonymous enums if all variants match a regex.
+        // Note: This will also block anonymous enums with no variants, but
+        // adding a typedef for such an enum should be useless anyway.
+        if enum_ty.name().is_none() &&
+            self.variants()
+                .iter()
+                .all(|v| ctx.options().blocklisted_items.matches(v.name()))
+        {
+            debug!("Blocklisting anonymous enum.");
+            return;
+        }
+
         let repr_translated;
         let repr = match self.repr().map(|repr| ctx.resolve_type(repr)) {
             Some(repr)

bindgen-tests/tests/headers/issue-1025-unknown-enum-repr.hpp

@@ -150,7 +150,11 @@ impl Enum {
         Ok(Enum::new(repr, variants))
     }
 
-    fn is_matching_enum(
+    /// Checks if the enum matches any of the regular expressions in `enums`
+    ///
+    /// For anonymous enums, returns true if any of the enum variants matches
+    /// any of the regular expressions in `enums`.
+    pub(crate) fn is_matching_enum(
         &self,
         ctx: &BindgenContext,
         enums: &RegexSet,