lib/Analysis/PostDominators.cpp

   1 //===- PostDominators.cpp - Post-Dominator Calculation --------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the post-dominator construction algorithms.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/Analysis/PostDominators.h"
  14 #include "llvm/IR/Function.h"
  15 #include "llvm/IR/PassManager.h"
  16 #include "llvm/Pass.h"
  17 #include "llvm/Support/raw_ostream.h"
  18
  19 using namespace llvm;
  20
  21 #define DEBUG_TYPE "postdomtree"
  22
  23 #ifdef EXPENSIVE_CHECKS
  24 static constexpr bool ExpensiveChecksEnabled = true;
  25 #else
  26 static constexpr bool ExpensiveChecksEnabled = false;
  27 #endif
  28
  29 //===----------------------------------------------------------------------===//
  30 //  PostDominatorTree Implementation
  31 //===----------------------------------------------------------------------===//
  32
  33 char PostDominatorTreeWrapperPass::ID = 0;
  34
  35 INITIALIZE_PASS(PostDominatorTreeWrapperPass, "postdomtree",
  36                 "Post-Dominator Tree Construction", true, true)
  37
  38 bool PostDominatorTree::invalidate(Function &F, const PreservedAnalyses &PA,
  39                                    FunctionAnalysisManager::Invalidator &) {
  40   // Check whether the analysis, all analyses on functions, or the function's
  41   // CFG have been preserved.
  42   auto PAC = PA.getChecker<PostDominatorTreeAnalysis>();
  43   return !(PAC.preserved() || PAC.preservedSet<AllAnalysesOn<Function>>() ||
  44            PAC.preservedSet<CFGAnalyses>());
  45 }
  46
  47 bool PostDominatorTreeWrapperPass::runOnFunction(Function &F) {
  48   DT.recalculate(F);
  49   return false;
  50 }
  51
  52 void PostDominatorTreeWrapperPass::verifyAnalysis() const {
  53   if (VerifyDomInfo)
  54     assert(DT.verify(PostDominatorTree::VerificationLevel::Full));
  55   else if (ExpensiveChecksEnabled)
  56     assert(DT.verify(PostDominatorTree::VerificationLevel::Basic));
  57 }
  58
  59 void PostDominatorTreeWrapperPass::print(raw_ostream &OS, const Module *) const {
  60   DT.print(OS);
  61 }
  62
  63 FunctionPass* llvm::createPostDomTree() {
  64   return new PostDominatorTreeWrapperPass();
  65 }
  66
  67 AnalysisKey PostDominatorTreeAnalysis::Key;
  68
  69 PostDominatorTree PostDominatorTreeAnalysis::run(Function &F,
  70                                                  FunctionAnalysisManager &) {
  71   PostDominatorTree PDT(F);
  72   return PDT;
  73 }
  74
  75 PostDominatorTreePrinterPass::PostDominatorTreePrinterPass(raw_ostream &OS)
  76   : OS(OS) {}
  77
  78 PreservedAnalyses
  79 PostDominatorTreePrinterPass::run(Function &F, FunctionAnalysisManager &AM) {
  80   OS << "PostDominatorTree for function: " << F.getName() << "\n";
  81   AM.getResult<PostDominatorTreeAnalysis>(F).print(OS);
  82
  83   return PreservedAnalyses::all();
  84 }