[Mlir-commits] [mlir] [mlir][pass] Allow reregistration of pass with same typeids (PR #72067)

[Maksim Levental]

================
@@ -181,4 +182,48 @@ TEST(PassManagerTest, PassInitialization) {
   EXPECT_TRUE(succeeded(pm.run(module.get())));
 }
 
+struct ReRegisterPass
+    : public PassWrapper<ReRegisterPass, OperationPass<ModuleOp>> {
+  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(ReRegisterPass)
+
+  ReRegisterPass(std::string annotation) : annotation(annotation) {}
+
+  std::string annotation;
+
+  void runOnOperation() override {
+    ModuleOp op = this->getOperation();
+    Builder builder(op);
+    op->walk([this, &builder](Operation *op) {
+      op->setAttr(annotation, builder.getUnitAttr());
+    });
+  }
+};
+
+TEST(PassManagerTest, PassReRegistration) {
+  MLIRContext context;
+  context.allowUnregisteredDialects();
+
+  std::string moduleStr = R"mlir(
+    module {
+      "custom.op1"() : () -> ()
+      "custom.op2"() : () -> ()
+    }
+  )mlir";
+
+  OwningOpRef<ModuleOp> module =
+      parseSourceString<ModuleOp>(moduleStr, &context);
+
+  // Instantiate and run pass in first configuration.
+  auto pm = PassManager::on<ModuleOp>(&context);
+  pm.addPass(std::make_unique<ReRegisterPass>("custom.first"));
+  EXPECT_TRUE(succeeded(pm.run(module.get())));
+  module->walk([](Operation *op) { EXPECT_TRUE(op->hasAttr("custom.first")); });
+
+  // Adding a "reconfiguration" of the pass, i.e., with a different annotation.
+  pm.addPass(std::make_unique<ReRegisterPass>("custom.second"));
----------------
makslevental wrote:

> I'm not sure I follow actually: how do you run such pass with `mlir-opt`?

You can't but `mlir-opt` isn't the only way that passes are run right? Anyone that embeds the pass manager in a library can register passes dynamically.

> Why does the registration part matters in this test? Is there an assertion hit if we run this test without the change in the library?

No but without the patch the second `addPass -> registerPass` is a no-op because of `try_emplace` which doesn't update the value (the pass info) associated with the key (the pass arg) if the key has already been stored in `passRegistry`.

https://github.com/llvm/llvm-project/pull/72067