lib/Analysis/PostDominators.cpp

   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 #ifdef EXPENSIVE_CHECKS
  25 static constexpr bool ExpensiveChecksEnabled = true;
  26 #else
  27 static constexpr bool ExpensiveChecksEnabled = false;
  28 #endif
  29
  30 //===----------------------------------------------------------------------===//
  31 //  PostDominatorTree Implementation
  32 //===----------------------------------------------------------------------===//
  33
  34 char PostDominatorTreeWrapperPass::ID = 0;
  35
  36 INITIALIZE_PASS(PostDominatorTreeWrapperPass, "postdomtree",
  37                 "Post-Dominator Tree Construction", true, true)
  38
  39 bool PostDominatorTree::invalidate(Function &F, const PreservedAnalyses &PA,
  40                                    FunctionAnalysisManager::Invalidator &) {
  41   // Check whether the analysis, all analyses on functions, or the function's
  42   // CFG have been preserved.
  43   auto PAC = PA.getChecker<PostDominatorTreeAnalysis>();
  44   return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() ||
  45            PAC.preservedSet<CFGAnalyses>());
  46 }
  47
  48 bool PostDominatorTreeWrapperPass::runOnFunction(Function &F) {
  49   DT.recalculate(F);
  50   return false;
  51 }
  52
  53 void PostDominatorTreeWrapperPass::verifyAnalysis() const {
  54   if (VerifyDomInfo)
  55     assert(DT.verify(PostDominatorTree::VerificationLevel::Full));
  56   else if (ExpensiveChecksEnabled)
  57     assert(DT.verify(PostDominatorTree::VerificationLevel::Basic));
  58 }
  59
  60 void PostDominatorTreeWrapperPass::print(raw_ostream &OS, const Module *) const {
  61   DT.print(OS);
  62 }
  63
  64 FunctionPass* llvm::createPostDomTree() {
  65   return new PostDominatorTreeWrapperPass();
  66 }
  67
  68 AnalysisKey PostDominatorTreeAnalysis::Key;
  69
  70 PostDominatorTree PostDominatorTreeAnalysis::run(Function &F,
  71                                                  FunctionAnalysisManager &) {
  72   PostDominatorTree PDT(F);
  73   return PDT;
  74 }
  75
  76 PostDominatorTreePrinterPass::PostDominatorTreePrinterPass(raw_ostream &OS)
  77   : OS(OS) {}
  78
  79 PreservedAnalyses
  80 PostDominatorTreePrinterPass::run(Function &F, FunctionAnalysisManager &AM) {
  81   OS << "PostDominatorTree for function: " << F.getName() << "\n";
  82   AM.getResult<PostDominatorTreeAnalysis>(F).print(OS);
  83
  84   return PreservedAnalyses::all();
  85 }