From 54f69caf1f3e92ee147bac7e508ba65aff5ed1d5 Mon Sep 17 00:00:00 2001
From: Matthias Springer <me@m-sp.org>
Date: Thu, 20 Nov 2025 17:51:44 +0800
Subject: [PATCH] [mlir][Pass] Fix crash when applying a pass to an optional
 interface (#168499)

Interfaces can be optional: whether an op implements an interface or not
can depend on the state of the operation.

```
  // An optional code block for adding additional "classof" logic. This can
  // be used to better enable "optional" interfaces, where an entity only
  // implements the interface if some dynamic characteristic holds.
  // `$_attr`/`$_op`/`$_type` may be used to refer to an instance of the
  // interface instance being checked.
  code extraClassOf = "";
```

The current `Pass::canScheduleOn(RegisteredOperationName)` is
insufficient. This commit adds an additional overload to inspect
`Operation *`.

This commit fixes a crash when scheduling an `InterfacePass` for an
optional interface on an operation that does not actually implement the
interface.
---
 mlir/include/mlir/Pass/Pass.h                          |  8 ++++++++
 mlir/lib/Pass/Pass.cpp                                 |  6 +++---
 mlir/test/Dialect/Transform/test-pass-application.mlir |  2 +-
 mlir/test/Pass/invalid-unsupported-operation.mlir      | 10 ++++++++++
 mlir/test/Pass/pipeline-invalid.mlir                   |  2 +-
 5 files changed, 23 insertions(+), 5 deletions(-)
 create mode 100644 mlir/test/Pass/invalid-unsupported-operation.mlir

diff --git a/mlir/include/mlir/Pass/Pass.h b/mlir/include/mlir/Pass/Pass.h
index 16893c6db87b..448a68824349 100644
--- a/mlir/include/mlir/Pass/Pass.h
+++ b/mlir/include/mlir/Pass/Pass.h
@@ -193,6 +193,13 @@ protected:
   /// This is useful for generic operation passes to add restrictions on the
   /// operations they operate on.
   virtual bool canScheduleOn(RegisteredOperationName opName) const = 0;
+  virtual bool canScheduleOn(Operation *op) const {
+    std::optional<RegisteredOperationName> registeredInfo =
+        op->getName().getRegisteredInfo();
+    if (!registeredInfo)
+      return false;
+    return canScheduleOn(*registeredInfo);
+  }
 
   /// Schedule an arbitrary pass pipeline on the provided operation.
   /// This can be invoke any time in a pass to dynamic schedule more passes.
@@ -436,6 +443,7 @@ protected:
   /// Indicate if the current pass can be scheduled on the given operation type.
   /// For an InterfacePass, this checks if the operation implements the given
   /// interface.
+  bool canScheduleOn(Operation *op) const final { return isa<InterfaceT>(op); }
   bool canScheduleOn(RegisteredOperationName opName) const final {
     return opName.hasInterface<InterfaceT>();
   }
diff --git a/mlir/lib/Pass/Pass.cpp b/mlir/lib/Pass/Pass.cpp
index 521c7c6be17b..75f882606e0a 100644
--- a/mlir/lib/Pass/Pass.cpp
+++ b/mlir/lib/Pass/Pass.cpp
@@ -559,9 +559,9 @@ LogicalResult OpToOpPassAdaptor::run(Pass *pass, Operation *op,
     return op->emitOpError() << "trying to schedule a pass on an operation not "
                                 "marked as 'IsolatedFromAbove'";
   }
-  if (!pass->canScheduleOn(*op->getName().getRegisteredInfo())) {
-    return op->emitOpError()
-           << "trying to schedule a pass on an unsupported operation";
+  if (!pass->canScheduleOn(op)) {
+    return op->emitOpError() << "trying to schedule pass '" << pass->getName()
+                             << "' on an unsupported operation";
   }
 
   // Initialize the pass state with a callback for the pass to dynamically
diff --git a/mlir/test/Dialect/Transform/test-pass-application.mlir b/mlir/test/Dialect/Transform/test-pass-application.mlir
index ce8f69c58701..4806daf7ce73 100644
--- a/mlir/test/Dialect/Transform/test-pass-application.mlir
+++ b/mlir/test/Dialect/Transform/test-pass-application.mlir
@@ -386,7 +386,7 @@ module attributes {transform.with_named_sequence} {
 // -----
 
 module attributes {transform.with_named_sequence} {
-  // expected-error @below {{trying to schedule a pass on an unsupported operation}}
+  // expected-error @below {{trying to schedule pass 'DuplicateFunctionEliminationPass' on an unsupported operation}}
   // expected-note @below {{target op}}
   func.func @invalid_target_op_type() {
     return
diff --git a/mlir/test/Pass/invalid-unsupported-operation.mlir b/mlir/test/Pass/invalid-unsupported-operation.mlir
new file mode 100644
index 000000000000..0ff49448c1da
--- /dev/null
+++ b/mlir/test/Pass/invalid-unsupported-operation.mlir
@@ -0,0 +1,10 @@
+// RUN: mlir-opt %s -test-print-liveness -split-input-file -verify-diagnostics
+
+// Unnamed modules do not implement SymbolOpInterface.
+// expected-error @+1 {{trying to schedule pass '(anonymous namespace)::TestLivenessPass' on an unsupported operation}}
+module {}
+
+// -----
+
+// Named modules implement SymbolOpInterface.
+module @named_module {}
diff --git a/mlir/test/Pass/pipeline-invalid.mlir b/mlir/test/Pass/pipeline-invalid.mlir
index 948a13384bc7..4116e127a24a 100644
--- a/mlir/test/Pass/pipeline-invalid.mlir
+++ b/mlir/test/Pass/pipeline-invalid.mlir
@@ -15,5 +15,5 @@ arith.constant 0
 
 // -----
 
-// expected-error@below {{trying to schedule a pass on an unsupported operation}}
+// expected-error@below {{trying to schedule pass '(anonymous namespace)::TestFunctionPass' on an unsupported operation}}
 module {}