/*
 * Copyright 2026 WebAssembly Community Group participants
 *
 * 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.
 */

//
// Applies @binaryen.noreturn to relevant functions. The OptimizeNoReturn pass
// can then use that information.
//
// This pass is not run by default, as then the annotations would persist if the
// user forgets to strip them. TODO: perhaps run this by default but also clean
// up the annotations at the end of the pipeline?
//

#include "ir/lubs.h"
#include "pass.h"
#include "wasm.h"

namespace wasm {

struct MarkNoReturn : public Pass {
  void run(Module* module) override {
    // MarkNoReturn itself cannot be function-parallel, as it adds
    // annotations, which could race with passes that read them. We are
    // therefore a module-level pass, internally parallel.
    struct Inner : public WalkerPass<PostWalker<Inner>> {
      bool isFunctionParallel() override { return true; }

      std::unique_ptr<Pass> create() override {
        return std::make_unique<Inner>();
      }

      void doWalkFunction(Function* func) {
        if (!LUB::getResultsLUB(func, *getModule(), LUB::AllResults).noted()) {
          func->funcAnnotations.noReturn = true;
        }
      }
    };

    Inner().run(getPassRunner(), module);
  }
};

Pass* createMarkNoReturnPass() { return new MarkNoReturn(); }

} // namespace wasm