1//=- llvm/Analysis/PostDominators.h - Post Dominator Calculation-*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file exposes interfaces to post dominance information.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_ANALYSIS_POSTDOMINATORS_H
15#define LLVM_ANALYSIS_POSTDOMINATORS_H
16
17#include "llvm/IR/Dominators.h"
18
19namespace llvm {
20
21/// PostDominatorTree Class - Concrete subclass of DominatorTree that is used to
22/// compute the a post-dominator tree.
23///
24struct PostDominatorTree : public FunctionPass {
25  static char ID; // Pass identification, replacement for typeid
26  DominatorTreeBase<BasicBlock>* DT;
27
28  PostDominatorTree() : FunctionPass(ID) {
29    initializePostDominatorTreePass(*PassRegistry::getPassRegistry());
30    DT = new DominatorTreeBase<BasicBlock>(true);
31  }
32
33  ~PostDominatorTree();
34
35  bool runOnFunction(Function &F) override;
36
37  void getAnalysisUsage(AnalysisUsage &AU) const override {
38    AU.setPreservesAll();
39  }
40
41  inline const std::vector<BasicBlock*> &getRoots() const {
42    return DT->getRoots();
43  }
44
45  inline DomTreeNode *getRootNode() const {
46    return DT->getRootNode();
47  }
48
49  inline DomTreeNode *operator[](BasicBlock *BB) const {
50    return DT->getNode(BB);
51  }
52
53  inline DomTreeNode *getNode(BasicBlock *BB) const {
54    return DT->getNode(BB);
55  }
56
57  inline bool dominates(DomTreeNode* A, DomTreeNode* B) const {
58    return DT->dominates(A, B);
59  }
60
61  inline bool dominates(const BasicBlock* A, const BasicBlock* B) const {
62    return DT->dominates(A, B);
63  }
64
65  inline bool properlyDominates(const DomTreeNode* A, DomTreeNode* B) const {
66    return DT->properlyDominates(A, B);
67  }
68
69  inline bool properlyDominates(BasicBlock* A, BasicBlock* B) const {
70    return DT->properlyDominates(A, B);
71  }
72
73  inline BasicBlock *findNearestCommonDominator(BasicBlock *A, BasicBlock *B) {
74    return DT->findNearestCommonDominator(A, B);
75  }
76
77  inline const BasicBlock *findNearestCommonDominator(const BasicBlock *A,
78                                                      const BasicBlock *B) {
79    return DT->findNearestCommonDominator(A, B);
80  }
81
82  /// Get all nodes post-dominated by R, including R itself.
83  void getDescendants(BasicBlock *R,
84                      SmallVectorImpl<BasicBlock *> &Result) const {
85    DT->getDescendants(R, Result);
86  }
87
88  void releaseMemory() override {
89    DT->releaseMemory();
90  }
91
92  void print(raw_ostream &OS, const Module*) const override;
93};
94
95FunctionPass* createPostDomTree();
96
97template <> struct GraphTraits<PostDominatorTree*>
98  : public GraphTraits<DomTreeNode*> {
99  static NodeType *getEntryNode(PostDominatorTree *DT) {
100    return DT->getRootNode();
101  }
102
103  static nodes_iterator nodes_begin(PostDominatorTree *N) {
104    if (getEntryNode(N))
105      return df_begin(getEntryNode(N));
106    else
107      return df_end(getEntryNode(N));
108  }
109
110  static nodes_iterator nodes_end(PostDominatorTree *N) {
111    return df_end(getEntryNode(N));
112  }
113};
114
115} // End llvm namespace
116
117#endif
118