1 //===- PostDominators.cpp - Post-Dominator Calculation --------------------===//
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 implements the post-dominator construction algorithms.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Analysis/PostDominators.h"
15 #include "llvm/ADT/DepthFirstIterator.h"
16 #include "llvm/ADT/SetOperations.h"
17 #include "llvm/IR/CFG.h"
18 #include "llvm/IR/Instructions.h"
19 #include "llvm/IR/PassManager.h"
20 #include "llvm/Support/Debug.h"
21 #include "llvm/Support/GenericDomTreeConstruction.h"
22 using namespace llvm;
23 
24 #define DEBUG_TYPE "postdomtree"
25 
26 //===----------------------------------------------------------------------===//
27 //  PostDominatorTree Implementation
28 //===----------------------------------------------------------------------===//
29 
30 char PostDominatorTreeWrapperPass::ID = 0;
31 INITIALIZE_PASS(PostDominatorTreeWrapperPass, "postdomtree",
32                 "Post-Dominator Tree Construction", true, true)
33 
34 bool PostDominatorTree::invalidate(Function &F, const PreservedAnalyses &PA,
35                                    FunctionAnalysisManager::Invalidator &) {
36   // Check whether the analysis, all analyses on functions, or the function's
37   // CFG have been preserved.
38   auto PAC = PA.getChecker<PostDominatorTreeAnalysis>();
39   return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() ||
40            PAC.preservedSet<CFGAnalyses>());
41 }
42 
43 bool PostDominatorTreeWrapperPass::runOnFunction(Function &F) {
44   DT.recalculate(F);
45   return false;
46 }
47 
48 void PostDominatorTreeWrapperPass::print(raw_ostream &OS, const Module *) const {
49   DT.print(OS);
50 }
51 
52 FunctionPass* llvm::createPostDomTree() {
53   return new PostDominatorTreeWrapperPass();
54 }
55 
56 AnalysisKey PostDominatorTreeAnalysis::Key;
57 
58 PostDominatorTree PostDominatorTreeAnalysis::run(Function &F,
59                                                  FunctionAnalysisManager &) {
60   PostDominatorTree PDT;
61   PDT.recalculate(F);
62   return PDT;
63 }
64 
65 PostDominatorTreePrinterPass::PostDominatorTreePrinterPass(raw_ostream &OS)
66   : OS(OS) {}
67 
68 PreservedAnalyses
69 PostDominatorTreePrinterPass::run(Function &F, FunctionAnalysisManager &AM) {
70   OS << "PostDominatorTree for function: " << F.getName() << "\n";
71   AM.getResult<PostDominatorTreeAnalysis>(F).print(OS);
72 
73   return PreservedAnalyses::all();
74 }
75