[Mlir-commits] [mlir] [mlir] fix Operation::getDiscardableAttrs in absence of properties (PR #76816)

[Mehdi Amini]

================
@@ -475,19 +475,31 @@ class alignas(8) Operation final
     return removeDiscardableAttr(StringAttr::get(getContext(), name));
   }
 
-  /// Return all of the discardable attributes on this operation.
-  ArrayRef<NamedAttribute> getDiscardableAttrs() { return attrs.getValue(); }
+  /// Return a range of all of discardable attributes on this operation. Note
+  /// that for unregistered operations, all attributes are considered
+  /// discardable.
+  auto getDiscardableAttrs() {
+    std::optional<RegisteredOperationName> opName = getRegisteredInfo();
+    ArrayRef<StringAttr> attributeNames =
+        opName ? getRegisteredInfo()->getAttributeNames()
+               : ArrayRef<StringAttr>();
+    return llvm::make_filter_range(
+        attrs.getValue(),
+        [this, attributeNames](const NamedAttribute attribute) {
+          return getPropertiesStorage() ||
+                 !llvm::is_contained(attributeNames, attribute.getName());
+        });
+  }
 
   /// Return all of the discardable attributes on this operation as a
   /// DictionaryAttr.
-  DictionaryAttr getDiscardableAttrDictionary() { return attrs; }
+  DictionaryAttr getDiscardableAttrDictionary() {
+    return DictionaryAttr::get(getContext(),
+                               llvm::to_vector(getDiscardableAttrs()));
----------------
joker-eph wrote:

We should keep the fast-path I think:

```
if (getPropertiesStorage()) return attrs;
```

https://github.com/llvm/llvm-project/pull/76816