text: //===- TestPassManager.cpp - Test pass manager functionality --------------===//
  //
  // Copyright 2019 The MLIR Authors.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  // =============================================================================
  
  #include "mlir/IR/Function.h"
  #include "mlir/Pass/Pass.h"
  #include "mlir/Pass/PassManager.h"
  
  using namespace mlir;
  
  namespace {
  struct TestModulePass : public ModulePass<TestModulePass> {
    void runOnModule() final {}
  };
  struct TestFunctionPass : public FunctionPass<TestFunctionPass> {
    void runOnFunction() final {}
  };
  } // namespace
  
  static void testNestedPipeline(OpPassManager &pm) {
    // Nest a module pipeline that contains:
    /// A module pass.
    auto &modulePM = pm.nest<ModuleOp>();
    modulePM.addPass(std::make_unique<TestModulePass>());
    /// A nested function pass.
    auto &nestedFunctionPM = modulePM.nest<FuncOp>();
    nestedFunctionPM.addPass(std::make_unique<TestFunctionPass>());
  
    // Nest a function pipeline that contains a single pass.
    auto &functionPM = pm.nest<FuncOp>();
    functionPM.addPass(std::make_unique<TestFunctionPass>());
  }
  
  static void testNestedPipelineTextual(OpPassManager &pm) {
    (void)parsePassPipeline("test-pm-nested-pipeline", pm);
  }
  
  static PassRegistration<TestModulePass>
      unusedMP("test-module-pass", "Test a module pass in the pass manager");
  static PassRegistration<TestFunctionPass>
      unusedFP("test-function-pass", "Test a function pass in the pass manager");
  
  static PassPipelineRegistration
      unused("test-pm-nested-pipeline",
             "Test a nested pipeline in the pass manager", testNestedPipeline);
  static PassPipelineRegistration
      unusedTextual("test-textual-pm-nested-pipeline",
                    "Test a nested pipeline in the pass manager",
                    testNestedPipelineTextual);
  