//=- llvm/Analysis/PostDominators.h - Post Dominator Calculation-*- C++ -*-===//

//

//                     The LLVM Compiler Infrastructure

//

// This file is distributed under the University of Illinois Open Source

// License. See LICENSE.TXT for details.

//

//===----------------------------------------------------------------------===//

//

// This file exposes interfaces to post dominance information.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_POSTDOMINATORS_H

#define LLVM_ANALYSIS_POSTDOMINATORS_H

#include "llvm/IR/Dominators.h"

namespace llvm {

/// PostDominatorTree Class - Concrete subclass of DominatorTree that is used to

/// compute the post-dominator tree.

///

struct PostDominatorTree : public FunctionPass {

  static char ID; // Pass identification, replacement for typeid

  DominatorTreeBase<BasicBlock>* DT;

  PostDominatorTree() : FunctionPass(ID) {

    initializePostDominatorTreePass(*PassRegistry::getPassRegistry());

    DT = new DominatorTreeBase<BasicBlock>(true);

  }

  ~PostDominatorTree() override;

  bool runOnFunction(Function &F) override;

  void getAnalysisUsage(AnalysisUsage &AU) const override {

    AU.setPreservesAll();

  }

  inline const std::vector<BasicBlock*> &getRoots() const {

    return DT->getRoots();

  }

  inline DomTreeNode *getRootNode() const {

    return DT->getRootNode();

  }

  inline DomTreeNode *operator[](BasicBlock *BB) const {

    return DT->getNode(BB);

  }

  inline DomTreeNode *getNode(BasicBlock *BB) const {

    return DT->getNode(BB);

  }

  inline bool dominates(DomTreeNode* A, DomTreeNode* B) const {

    return DT->dominates(A, B);

  }

  inline bool dominates(const BasicBlock* A, const BasicBlock* B) const {

    return DT->dominates(A, B);

  }

  inline bool properlyDominates(const DomTreeNode* A, DomTreeNode* B) const {

    return DT->properlyDominates(A, B);

  }

  inline bool properlyDominates(BasicBlock* A, BasicBlock* B) const {

    return DT->properlyDominates(A, B);

  }

  inline BasicBlock *findNearestCommonDominator(BasicBlock *A, BasicBlock *B) {

    return DT->findNearestCommonDominator(A, B);

  }

  inline const BasicBlock *findNearestCommonDominator(const BasicBlock *A,

                                                      const BasicBlock *B) {

    return DT->findNearestCommonDominator(A, B);

  }

  /// Get all nodes post-dominated by R, including R itself.

  void getDescendants(BasicBlock *R,

                      SmallVectorImpl<BasicBlock *> &Result) const {

    DT->getDescendants(R, Result);

  }

  void releaseMemory() override {

    DT->releaseMemory();

  }

  void print(raw_ostream &OS, const Module*) const override;

};

FunctionPass* createPostDomTree();

template <> struct GraphTraits<PostDominatorTree*>

  : public GraphTraits<DomTreeNode*> {

  static NodeType *getEntryNode(PostDominatorTree *DT) {

    return DT->getRootNode();

  }

  static nodes_iterator nodes_begin(PostDominatorTree *N) {

    if (getEntryNode(N))

      return df_begin(getEntryNode(N));

    else

      return df_end(getEntryNode(N));

  }

  static nodes_iterator nodes_end(PostDominatorTree *N) {

    return df_end(getEntryNode(N));

  }

};

} // End llvm namespace

#endif