//===- BitcodeWriterPass.cpp - Bitcode writing pass -----------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// BitcodeWriterPass implementation.
//
//===----------------------------------------------------------------------===//

#include "llvm/Bitcode/BitcodeWriterPass.h"
#include "llvm/Analysis/ModuleSummaryAnalysis.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/PassManager.h"
#include "llvm/Pass.h"
using namespace llvm;

PreservedAnalyses BitcodeWriterPass::run(Module &M) {
  std::unique_ptr<ModuleSummaryIndex> Index;
  if (EmitSummaryIndex)
    Index = ModuleSummaryIndexBuilder(&M).takeIndex();
  WriteBitcodeToFile(&M, OS, ShouldPreserveUseListOrder, Index.get(),
                     EmitModuleHash);
  return PreservedAnalyses::all();
}

namespace {
  class WriteBitcodePass : public ModulePass {
    raw_ostream &OS; // raw_ostream to print on
    bool ShouldPreserveUseListOrder;
    bool EmitSummaryIndex;
    bool EmitModuleHash;

  public:
    static char ID; // Pass identification, replacement for typeid
    WriteBitcodePass() : ModulePass(ID), OS(dbgs()) {
      initializeWriteBitcodePassPass(*PassRegistry::getPassRegistry());
    }

    explicit WriteBitcodePass(raw_ostream &o, bool ShouldPreserveUseListOrder,
                              bool EmitSummaryIndex, bool EmitModuleHash)
        : ModulePass(ID), OS(o),
          ShouldPreserveUseListOrder(ShouldPreserveUseListOrder),
          EmitSummaryIndex(EmitSummaryIndex), EmitModuleHash(EmitModuleHash) {
      initializeWriteBitcodePassPass(*PassRegistry::getPassRegistry());
    }

    const char *getPassName() const override { return "Bitcode Writer"; }

    bool runOnModule(Module &M) override {
      const ModuleSummaryIndex *Index =
          EmitSummaryIndex
              ? &(getAnalysis<ModuleSummaryIndexWrapperPass>().getIndex())
              : nullptr;
      WriteBitcodeToFile(&M, OS, ShouldPreserveUseListOrder, Index,
                         EmitModuleHash);
      return false;
    }
    void getAnalysisUsage(AnalysisUsage &AU) const override {
      AU.setPreservesAll();
      if (EmitSummaryIndex)
        AU.addRequired<ModuleSummaryIndexWrapperPass>();
    }
  };
}

char WriteBitcodePass::ID = 0;
INITIALIZE_PASS_BEGIN(WriteBitcodePass, "write-bitcode", "Write Bitcode", false,
                      true)
INITIALIZE_PASS_DEPENDENCY(ModuleSummaryIndexWrapperPass)
INITIALIZE_PASS_END(WriteBitcodePass, "write-bitcode", "Write Bitcode", false,
                    true)

ModulePass *llvm::createBitcodeWriterPass(raw_ostream &Str,
                                          bool ShouldPreserveUseListOrder,
                                          bool EmitSummaryIndex, bool EmitModuleHash) {
  return new WriteBitcodePass(Str, ShouldPreserveUseListOrder,
                              EmitSummaryIndex, EmitModuleHash);
}