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