1//===- LegacyPassManager.cpp - LLVM Pass Infrastructure Implementation ----===//
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 legacy LLVM Pass Manager infrastructure.
11//
12//===----------------------------------------------------------------------===//
13
14
15#include "llvm/IR/LLVMContext.h"
16#include "llvm/IR/IRPrintingPasses.h"
17#include "llvm/IR/LegacyPassManager.h"
18#include "llvm/IR/LegacyPassManagers.h"
19#include "llvm/IR/LegacyPassNameParser.h"
20#include "llvm/IR/Module.h"
21#include "llvm/Support/CommandLine.h"
22#include "llvm/Support/Debug.h"
23#include "llvm/Support/ErrorHandling.h"
24#include "llvm/Support/ManagedStatic.h"
25#include "llvm/Support/Mutex.h"
26#include "llvm/Support/TimeValue.h"
27#include "llvm/Support/Timer.h"
28#include "llvm/Support/raw_ostream.h"
29#include <algorithm>
30#include <map>
31using namespace llvm;
32using namespace llvm::legacy;
33
34// See PassManagers.h for Pass Manager infrastructure overview.
35
36//===----------------------------------------------------------------------===//
37// Pass debugging information.  Often it is useful to find out what pass is
38// running when a crash occurs in a utility.  When this library is compiled with
39// debugging on, a command line option (--debug-pass) is enabled that causes the
40// pass name to be printed before it executes.
41//
42
43namespace {
44// Different debug levels that can be enabled...
45enum PassDebugLevel {
46  Disabled, Arguments, Structure, Executions, Details
47};
48}
49
50static cl::opt<enum PassDebugLevel>
51PassDebugging("debug-pass", cl::Hidden,
52                  cl::desc("Print PassManager debugging information"),
53                  cl::values(
54  clEnumVal(Disabled  , "disable debug output"),
55  clEnumVal(Arguments , "print pass arguments to pass to 'opt'"),
56  clEnumVal(Structure , "print pass structure before run()"),
57  clEnumVal(Executions, "print pass name before it is executed"),
58  clEnumVal(Details   , "print pass details when it is executed"),
59                             clEnumValEnd));
60
61namespace {
62typedef llvm::cl::list<const llvm::PassInfo *, bool, PassNameParser>
63PassOptionList;
64}
65
66// Print IR out before/after specified passes.
67static PassOptionList
68PrintBefore("print-before",
69            llvm::cl::desc("Print IR before specified passes"),
70            cl::Hidden);
71
72static PassOptionList
73PrintAfter("print-after",
74           llvm::cl::desc("Print IR after specified passes"),
75           cl::Hidden);
76
77static cl::opt<bool>
78PrintBeforeAll("print-before-all",
79               llvm::cl::desc("Print IR before each pass"),
80               cl::init(false));
81static cl::opt<bool>
82PrintAfterAll("print-after-all",
83              llvm::cl::desc("Print IR after each pass"),
84              cl::init(false));
85
86/// This is a helper to determine whether to print IR before or
87/// after a pass.
88
89static bool ShouldPrintBeforeOrAfterPass(const PassInfo *PI,
90                                         PassOptionList &PassesToPrint) {
91  for (unsigned i = 0, ie = PassesToPrint.size(); i < ie; ++i) {
92    const llvm::PassInfo *PassInf = PassesToPrint[i];
93    if (PassInf)
94      if (PassInf->getPassArgument() == PI->getPassArgument()) {
95        return true;
96      }
97  }
98  return false;
99}
100
101/// This is a utility to check whether a pass should have IR dumped
102/// before it.
103static bool ShouldPrintBeforePass(const PassInfo *PI) {
104  return PrintBeforeAll || ShouldPrintBeforeOrAfterPass(PI, PrintBefore);
105}
106
107/// This is a utility to check whether a pass should have IR dumped
108/// after it.
109static bool ShouldPrintAfterPass(const PassInfo *PI) {
110  return PrintAfterAll || ShouldPrintBeforeOrAfterPass(PI, PrintAfter);
111}
112
113/// isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions
114/// or higher is specified.
115bool PMDataManager::isPassDebuggingExecutionsOrMore() const {
116  return PassDebugging >= Executions;
117}
118
119
120
121
122void PassManagerPrettyStackEntry::print(raw_ostream &OS) const {
123  if (!V && !M)
124    OS << "Releasing pass '";
125  else
126    OS << "Running pass '";
127
128  OS << P->getPassName() << "'";
129
130  if (M) {
131    OS << " on module '" << M->getModuleIdentifier() << "'.\n";
132    return;
133  }
134  if (!V) {
135    OS << '\n';
136    return;
137  }
138
139  OS << " on ";
140  if (isa<Function>(V))
141    OS << "function";
142  else if (isa<BasicBlock>(V))
143    OS << "basic block";
144  else
145    OS << "value";
146
147  OS << " '";
148  V->printAsOperand(OS, /*PrintTy=*/false, M);
149  OS << "'\n";
150}
151
152
153namespace {
154//===----------------------------------------------------------------------===//
155// BBPassManager
156//
157/// BBPassManager manages BasicBlockPass. It batches all the
158/// pass together and sequence them to process one basic block before
159/// processing next basic block.
160class BBPassManager : public PMDataManager, public FunctionPass {
161
162public:
163  static char ID;
164  explicit BBPassManager()
165    : PMDataManager(), FunctionPass(ID) {}
166
167  /// Execute all of the passes scheduled for execution.  Keep track of
168  /// whether any of the passes modifies the function, and if so, return true.
169  bool runOnFunction(Function &F) override;
170
171  /// Pass Manager itself does not invalidate any analysis info.
172  void getAnalysisUsage(AnalysisUsage &Info) const override {
173    Info.setPreservesAll();
174  }
175
176  bool doInitialization(Module &M) override;
177  bool doInitialization(Function &F);
178  bool doFinalization(Module &M) override;
179  bool doFinalization(Function &F);
180
181  PMDataManager *getAsPMDataManager() override { return this; }
182  Pass *getAsPass() override { return this; }
183
184  const char *getPassName() const override {
185    return "BasicBlock Pass Manager";
186  }
187
188  // Print passes managed by this manager
189  void dumpPassStructure(unsigned Offset) override {
190    dbgs().indent(Offset*2) << "BasicBlockPass Manager\n";
191    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
192      BasicBlockPass *BP = getContainedPass(Index);
193      BP->dumpPassStructure(Offset + 1);
194      dumpLastUses(BP, Offset+1);
195    }
196  }
197
198  BasicBlockPass *getContainedPass(unsigned N) {
199    assert(N < PassVector.size() && "Pass number out of range!");
200    BasicBlockPass *BP = static_cast<BasicBlockPass *>(PassVector[N]);
201    return BP;
202  }
203
204  PassManagerType getPassManagerType() const override {
205    return PMT_BasicBlockPassManager;
206  }
207};
208
209char BBPassManager::ID = 0;
210} // End anonymous namespace
211
212namespace llvm {
213namespace legacy {
214//===----------------------------------------------------------------------===//
215// FunctionPassManagerImpl
216//
217/// FunctionPassManagerImpl manages FPPassManagers
218class FunctionPassManagerImpl : public Pass,
219                                public PMDataManager,
220                                public PMTopLevelManager {
221  virtual void anchor();
222private:
223  bool wasRun;
224public:
225  static char ID;
226  explicit FunctionPassManagerImpl() :
227    Pass(PT_PassManager, ID), PMDataManager(),
228    PMTopLevelManager(new FPPassManager()), wasRun(false) {}
229
230  /// \copydoc FunctionPassManager::add()
231  void add(Pass *P) {
232    schedulePass(P);
233  }
234
235  /// createPrinterPass - Get a function printer pass.
236  Pass *createPrinterPass(raw_ostream &O,
237                          const std::string &Banner) const override {
238    return createPrintFunctionPass(O, Banner);
239  }
240
241  // Prepare for running an on the fly pass, freeing memory if needed
242  // from a previous run.
243  void releaseMemoryOnTheFly();
244
245  /// run - Execute all of the passes scheduled for execution.  Keep track of
246  /// whether any of the passes modifies the module, and if so, return true.
247  bool run(Function &F);
248
249  /// doInitialization - Run all of the initializers for the function passes.
250  ///
251  bool doInitialization(Module &M) override;
252
253  /// doFinalization - Run all of the finalizers for the function passes.
254  ///
255  bool doFinalization(Module &M) override;
256
257
258  PMDataManager *getAsPMDataManager() override { return this; }
259  Pass *getAsPass() override { return this; }
260  PassManagerType getTopLevelPassManagerType() override {
261    return PMT_FunctionPassManager;
262  }
263
264  /// Pass Manager itself does not invalidate any analysis info.
265  void getAnalysisUsage(AnalysisUsage &Info) const override {
266    Info.setPreservesAll();
267  }
268
269  FPPassManager *getContainedManager(unsigned N) {
270    assert(N < PassManagers.size() && "Pass number out of range!");
271    FPPassManager *FP = static_cast<FPPassManager *>(PassManagers[N]);
272    return FP;
273  }
274};
275
276void FunctionPassManagerImpl::anchor() {}
277
278char FunctionPassManagerImpl::ID = 0;
279} // End of legacy namespace
280} // End of llvm namespace
281
282namespace {
283//===----------------------------------------------------------------------===//
284// MPPassManager
285//
286/// MPPassManager manages ModulePasses and function pass managers.
287/// It batches all Module passes and function pass managers together and
288/// sequences them to process one module.
289class MPPassManager : public Pass, public PMDataManager {
290public:
291  static char ID;
292  explicit MPPassManager() :
293    Pass(PT_PassManager, ID), PMDataManager() { }
294
295  // Delete on the fly managers.
296  ~MPPassManager() override {
297    for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
298           I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
299         I != E; ++I) {
300      FunctionPassManagerImpl *FPP = I->second;
301      delete FPP;
302    }
303  }
304
305  /// createPrinterPass - Get a module printer pass.
306  Pass *createPrinterPass(raw_ostream &O,
307                          const std::string &Banner) const override {
308    return createPrintModulePass(O, Banner);
309  }
310
311  /// run - Execute all of the passes scheduled for execution.  Keep track of
312  /// whether any of the passes modifies the module, and if so, return true.
313  bool runOnModule(Module &M);
314
315  using llvm::Pass::doInitialization;
316  using llvm::Pass::doFinalization;
317
318  /// doInitialization - Run all of the initializers for the module passes.
319  ///
320  bool doInitialization();
321
322  /// doFinalization - Run all of the finalizers for the module passes.
323  ///
324  bool doFinalization();
325
326  /// Pass Manager itself does not invalidate any analysis info.
327  void getAnalysisUsage(AnalysisUsage &Info) const override {
328    Info.setPreservesAll();
329  }
330
331  /// Add RequiredPass into list of lower level passes required by pass P.
332  /// RequiredPass is run on the fly by Pass Manager when P requests it
333  /// through getAnalysis interface.
334  void addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) override;
335
336  /// Return function pass corresponding to PassInfo PI, that is
337  /// required by module pass MP. Instantiate analysis pass, by using
338  /// its runOnFunction() for function F.
339  Pass* getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F) override;
340
341  const char *getPassName() const override {
342    return "Module Pass Manager";
343  }
344
345  PMDataManager *getAsPMDataManager() override { return this; }
346  Pass *getAsPass() override { return this; }
347
348  // Print passes managed by this manager
349  void dumpPassStructure(unsigned Offset) override {
350    dbgs().indent(Offset*2) << "ModulePass Manager\n";
351    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
352      ModulePass *MP = getContainedPass(Index);
353      MP->dumpPassStructure(Offset + 1);
354      std::map<Pass *, FunctionPassManagerImpl *>::const_iterator I =
355        OnTheFlyManagers.find(MP);
356      if (I != OnTheFlyManagers.end())
357        I->second->dumpPassStructure(Offset + 2);
358      dumpLastUses(MP, Offset+1);
359    }
360  }
361
362  ModulePass *getContainedPass(unsigned N) {
363    assert(N < PassVector.size() && "Pass number out of range!");
364    return static_cast<ModulePass *>(PassVector[N]);
365  }
366
367  PassManagerType getPassManagerType() const override {
368    return PMT_ModulePassManager;
369  }
370
371 private:
372  /// Collection of on the fly FPPassManagers. These managers manage
373  /// function passes that are required by module passes.
374  std::map<Pass *, FunctionPassManagerImpl *> OnTheFlyManagers;
375};
376
377char MPPassManager::ID = 0;
378} // End anonymous namespace
379
380namespace llvm {
381namespace legacy {
382//===----------------------------------------------------------------------===//
383// PassManagerImpl
384//
385
386/// PassManagerImpl manages MPPassManagers
387class PassManagerImpl : public Pass,
388                        public PMDataManager,
389                        public PMTopLevelManager {
390  virtual void anchor();
391
392public:
393  static char ID;
394  explicit PassManagerImpl() :
395    Pass(PT_PassManager, ID), PMDataManager(),
396                              PMTopLevelManager(new MPPassManager()) {}
397
398  /// \copydoc PassManager::add()
399  void add(Pass *P) {
400    schedulePass(P);
401  }
402
403  /// createPrinterPass - Get a module printer pass.
404  Pass *createPrinterPass(raw_ostream &O,
405                          const std::string &Banner) const override {
406    return createPrintModulePass(O, Banner);
407  }
408
409  /// run - Execute all of the passes scheduled for execution.  Keep track of
410  /// whether any of the passes modifies the module, and if so, return true.
411  bool run(Module &M);
412
413  using llvm::Pass::doInitialization;
414  using llvm::Pass::doFinalization;
415
416  /// doInitialization - Run all of the initializers for the module passes.
417  ///
418  bool doInitialization();
419
420  /// doFinalization - Run all of the finalizers for the module passes.
421  ///
422  bool doFinalization();
423
424  /// Pass Manager itself does not invalidate any analysis info.
425  void getAnalysisUsage(AnalysisUsage &Info) const override {
426    Info.setPreservesAll();
427  }
428
429  PMDataManager *getAsPMDataManager() override { return this; }
430  Pass *getAsPass() override { return this; }
431  PassManagerType getTopLevelPassManagerType() override {
432    return PMT_ModulePassManager;
433  }
434
435  MPPassManager *getContainedManager(unsigned N) {
436    assert(N < PassManagers.size() && "Pass number out of range!");
437    MPPassManager *MP = static_cast<MPPassManager *>(PassManagers[N]);
438    return MP;
439  }
440};
441
442void PassManagerImpl::anchor() {}
443
444char PassManagerImpl::ID = 0;
445} // End of legacy namespace
446} // End of llvm namespace
447
448namespace {
449
450//===----------------------------------------------------------------------===//
451/// TimingInfo Class - This class is used to calculate information about the
452/// amount of time each pass takes to execute.  This only happens when
453/// -time-passes is enabled on the command line.
454///
455
456static ManagedStatic<sys::SmartMutex<true> > TimingInfoMutex;
457
458class TimingInfo {
459  DenseMap<Pass*, Timer*> TimingData;
460  TimerGroup TG;
461public:
462  // Use 'create' member to get this.
463  TimingInfo() : TG("... Pass execution timing report ...") {}
464
465  // TimingDtor - Print out information about timing information
466  ~TimingInfo() {
467    // Delete all of the timers, which accumulate their info into the
468    // TimerGroup.
469    for (DenseMap<Pass*, Timer*>::iterator I = TimingData.begin(),
470         E = TimingData.end(); I != E; ++I)
471      delete I->second;
472    // TimerGroup is deleted next, printing the report.
473  }
474
475  // createTheTimeInfo - This method either initializes the TheTimeInfo pointer
476  // to a non-null value (if the -time-passes option is enabled) or it leaves it
477  // null.  It may be called multiple times.
478  static void createTheTimeInfo();
479
480  /// getPassTimer - Return the timer for the specified pass if it exists.
481  Timer *getPassTimer(Pass *P) {
482    if (P->getAsPMDataManager())
483      return nullptr;
484
485    sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
486    Timer *&T = TimingData[P];
487    if (!T)
488      T = new Timer(P->getPassName(), TG);
489    return T;
490  }
491};
492
493} // End of anon namespace
494
495static TimingInfo *TheTimeInfo;
496
497//===----------------------------------------------------------------------===//
498// PMTopLevelManager implementation
499
500/// Initialize top level manager. Create first pass manager.
501PMTopLevelManager::PMTopLevelManager(PMDataManager *PMDM) {
502  PMDM->setTopLevelManager(this);
503  addPassManager(PMDM);
504  activeStack.push(PMDM);
505}
506
507/// Set pass P as the last user of the given analysis passes.
508void
509PMTopLevelManager::setLastUser(ArrayRef<Pass*> AnalysisPasses, Pass *P) {
510  unsigned PDepth = 0;
511  if (P->getResolver())
512    PDepth = P->getResolver()->getPMDataManager().getDepth();
513
514  for (SmallVectorImpl<Pass *>::const_iterator I = AnalysisPasses.begin(),
515         E = AnalysisPasses.end(); I != E; ++I) {
516    Pass *AP = *I;
517    LastUser[AP] = P;
518
519    if (P == AP)
520      continue;
521
522    // Update the last users of passes that are required transitive by AP.
523    AnalysisUsage *AnUsage = findAnalysisUsage(AP);
524    const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
525    SmallVector<Pass *, 12> LastUses;
526    SmallVector<Pass *, 12> LastPMUses;
527    for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
528         E = IDs.end(); I != E; ++I) {
529      Pass *AnalysisPass = findAnalysisPass(*I);
530      assert(AnalysisPass && "Expected analysis pass to exist.");
531      AnalysisResolver *AR = AnalysisPass->getResolver();
532      assert(AR && "Expected analysis resolver to exist.");
533      unsigned APDepth = AR->getPMDataManager().getDepth();
534
535      if (PDepth == APDepth)
536        LastUses.push_back(AnalysisPass);
537      else if (PDepth > APDepth)
538        LastPMUses.push_back(AnalysisPass);
539    }
540
541    setLastUser(LastUses, P);
542
543    // If this pass has a corresponding pass manager, push higher level
544    // analysis to this pass manager.
545    if (P->getResolver())
546      setLastUser(LastPMUses, P->getResolver()->getPMDataManager().getAsPass());
547
548
549    // If AP is the last user of other passes then make P last user of
550    // such passes.
551    for (DenseMap<Pass *, Pass *>::iterator LUI = LastUser.begin(),
552           LUE = LastUser.end(); LUI != LUE; ++LUI) {
553      if (LUI->second == AP)
554        // DenseMap iterator is not invalidated here because
555        // this is just updating existing entries.
556        LastUser[LUI->first] = P;
557    }
558  }
559}
560
561/// Collect passes whose last user is P
562void PMTopLevelManager::collectLastUses(SmallVectorImpl<Pass *> &LastUses,
563                                        Pass *P) {
564  DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator DMI =
565    InversedLastUser.find(P);
566  if (DMI == InversedLastUser.end())
567    return;
568
569  SmallPtrSet<Pass *, 8> &LU = DMI->second;
570  for (Pass *LUP : LU) {
571    LastUses.push_back(LUP);
572  }
573
574}
575
576AnalysisUsage *PMTopLevelManager::findAnalysisUsage(Pass *P) {
577  AnalysisUsage *AnUsage = nullptr;
578  DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.find(P);
579  if (DMI != AnUsageMap.end())
580    AnUsage = DMI->second;
581  else {
582    AnUsage = new AnalysisUsage();
583    P->getAnalysisUsage(*AnUsage);
584    AnUsageMap[P] = AnUsage;
585  }
586  return AnUsage;
587}
588
589/// Schedule pass P for execution. Make sure that passes required by
590/// P are run before P is run. Update analysis info maintained by
591/// the manager. Remove dead passes. This is a recursive function.
592void PMTopLevelManager::schedulePass(Pass *P) {
593
594  // TODO : Allocate function manager for this pass, other wise required set
595  // may be inserted into previous function manager
596
597  // Give pass a chance to prepare the stage.
598  P->preparePassManager(activeStack);
599
600  // If P is an analysis pass and it is available then do not
601  // generate the analysis again. Stale analysis info should not be
602  // available at this point.
603  const PassInfo *PI = findAnalysisPassInfo(P->getPassID());
604  if (PI && PI->isAnalysis() && findAnalysisPass(P->getPassID())) {
605    delete P;
606    return;
607  }
608
609  AnalysisUsage *AnUsage = findAnalysisUsage(P);
610
611  bool checkAnalysis = true;
612  while (checkAnalysis) {
613    checkAnalysis = false;
614
615    const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
616    for (AnalysisUsage::VectorType::const_iterator I = RequiredSet.begin(),
617           E = RequiredSet.end(); I != E; ++I) {
618
619      Pass *AnalysisPass = findAnalysisPass(*I);
620      if (!AnalysisPass) {
621        const PassInfo *PI = findAnalysisPassInfo(*I);
622
623        if (!PI) {
624          // Pass P is not in the global PassRegistry
625          dbgs() << "Pass '"  << P->getPassName() << "' is not initialized." << "\n";
626          dbgs() << "Verify if there is a pass dependency cycle." << "\n";
627          dbgs() << "Required Passes:" << "\n";
628          for (AnalysisUsage::VectorType::const_iterator I2 = RequiredSet.begin(),
629                 E = RequiredSet.end(); I2 != E && I2 != I; ++I2) {
630            Pass *AnalysisPass2 = findAnalysisPass(*I2);
631            if (AnalysisPass2) {
632              dbgs() << "\t" << AnalysisPass2->getPassName() << "\n";
633            } else {
634              dbgs() << "\t"   << "Error: Required pass not found! Possible causes:"  << "\n";
635              dbgs() << "\t\t" << "- Pass misconfiguration (e.g.: missing macros)"    << "\n";
636              dbgs() << "\t\t" << "- Corruption of the global PassRegistry"           << "\n";
637            }
638          }
639        }
640
641        assert(PI && "Expected required passes to be initialized");
642        AnalysisPass = PI->createPass();
643        if (P->getPotentialPassManagerType () ==
644            AnalysisPass->getPotentialPassManagerType())
645          // Schedule analysis pass that is managed by the same pass manager.
646          schedulePass(AnalysisPass);
647        else if (P->getPotentialPassManagerType () >
648                 AnalysisPass->getPotentialPassManagerType()) {
649          // Schedule analysis pass that is managed by a new manager.
650          schedulePass(AnalysisPass);
651          // Recheck analysis passes to ensure that required analyses that
652          // are already checked are still available.
653          checkAnalysis = true;
654        } else
655          // Do not schedule this analysis. Lower level analysis
656          // passes are run on the fly.
657          delete AnalysisPass;
658      }
659    }
660  }
661
662  // Now all required passes are available.
663  if (ImmutablePass *IP = P->getAsImmutablePass()) {
664    // P is a immutable pass and it will be managed by this
665    // top level manager. Set up analysis resolver to connect them.
666    PMDataManager *DM = getAsPMDataManager();
667    AnalysisResolver *AR = new AnalysisResolver(*DM);
668    P->setResolver(AR);
669    DM->initializeAnalysisImpl(P);
670    addImmutablePass(IP);
671    DM->recordAvailableAnalysis(IP);
672    return;
673  }
674
675  if (PI && !PI->isAnalysis() && ShouldPrintBeforePass(PI)) {
676    Pass *PP = P->createPrinterPass(
677      dbgs(), std::string("*** IR Dump Before ") + P->getPassName() + " ***");
678    PP->assignPassManager(activeStack, getTopLevelPassManagerType());
679  }
680
681  // Add the requested pass to the best available pass manager.
682  P->assignPassManager(activeStack, getTopLevelPassManagerType());
683
684  if (PI && !PI->isAnalysis() && ShouldPrintAfterPass(PI)) {
685    Pass *PP = P->createPrinterPass(
686      dbgs(), std::string("*** IR Dump After ") + P->getPassName() + " ***");
687    PP->assignPassManager(activeStack, getTopLevelPassManagerType());
688  }
689}
690
691/// Find the pass that implements Analysis AID. Search immutable
692/// passes and all pass managers. If desired pass is not found
693/// then return NULL.
694Pass *PMTopLevelManager::findAnalysisPass(AnalysisID AID) {
695
696  // Check pass managers
697  for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
698         E = PassManagers.end(); I != E; ++I)
699    if (Pass *P = (*I)->findAnalysisPass(AID, false))
700      return P;
701
702  // Check other pass managers
703  for (SmallVectorImpl<PMDataManager *>::iterator
704         I = IndirectPassManagers.begin(),
705         E = IndirectPassManagers.end(); I != E; ++I)
706    if (Pass *P = (*I)->findAnalysisPass(AID, false))
707      return P;
708
709  // Check the immutable passes. Iterate in reverse order so that we find
710  // the most recently registered passes first.
711  for (SmallVectorImpl<ImmutablePass *>::reverse_iterator I =
712       ImmutablePasses.rbegin(), E = ImmutablePasses.rend(); I != E; ++I) {
713    AnalysisID PI = (*I)->getPassID();
714    if (PI == AID)
715      return *I;
716
717    // If Pass not found then check the interfaces implemented by Immutable Pass
718    const PassInfo *PassInf = findAnalysisPassInfo(PI);
719    assert(PassInf && "Expected all immutable passes to be initialized");
720    const std::vector<const PassInfo*> &ImmPI =
721      PassInf->getInterfacesImplemented();
722    for (std::vector<const PassInfo*>::const_iterator II = ImmPI.begin(),
723         EE = ImmPI.end(); II != EE; ++II) {
724      if ((*II)->getTypeInfo() == AID)
725        return *I;
726    }
727  }
728
729  return nullptr;
730}
731
732const PassInfo *PMTopLevelManager::findAnalysisPassInfo(AnalysisID AID) const {
733  const PassInfo *&PI = AnalysisPassInfos[AID];
734  if (!PI)
735    PI = PassRegistry::getPassRegistry()->getPassInfo(AID);
736  else
737    assert(PI == PassRegistry::getPassRegistry()->getPassInfo(AID) &&
738           "The pass info pointer changed for an analysis ID!");
739
740  return PI;
741}
742
743// Print passes managed by this top level manager.
744void PMTopLevelManager::dumpPasses() const {
745
746  if (PassDebugging < Structure)
747    return;
748
749  // Print out the immutable passes
750  for (unsigned i = 0, e = ImmutablePasses.size(); i != e; ++i) {
751    ImmutablePasses[i]->dumpPassStructure(0);
752  }
753
754  // Every class that derives from PMDataManager also derives from Pass
755  // (sometimes indirectly), but there's no inheritance relationship
756  // between PMDataManager and Pass, so we have to getAsPass to get
757  // from a PMDataManager* to a Pass*.
758  for (SmallVectorImpl<PMDataManager *>::const_iterator I =
759       PassManagers.begin(), E = PassManagers.end(); I != E; ++I)
760    (*I)->getAsPass()->dumpPassStructure(1);
761}
762
763void PMTopLevelManager::dumpArguments() const {
764
765  if (PassDebugging < Arguments)
766    return;
767
768  dbgs() << "Pass Arguments: ";
769  for (SmallVectorImpl<ImmutablePass *>::const_iterator I =
770       ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
771    if (const PassInfo *PI = findAnalysisPassInfo((*I)->getPassID())) {
772      assert(PI && "Expected all immutable passes to be initialized");
773      if (!PI->isAnalysisGroup())
774        dbgs() << " -" << PI->getPassArgument();
775    }
776  for (SmallVectorImpl<PMDataManager *>::const_iterator I =
777       PassManagers.begin(), E = PassManagers.end(); I != E; ++I)
778    (*I)->dumpPassArguments();
779  dbgs() << "\n";
780}
781
782void PMTopLevelManager::initializeAllAnalysisInfo() {
783  for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
784         E = PassManagers.end(); I != E; ++I)
785    (*I)->initializeAnalysisInfo();
786
787  // Initailize other pass managers
788  for (SmallVectorImpl<PMDataManager *>::iterator
789       I = IndirectPassManagers.begin(), E = IndirectPassManagers.end();
790       I != E; ++I)
791    (*I)->initializeAnalysisInfo();
792
793  for (DenseMap<Pass *, Pass *>::iterator DMI = LastUser.begin(),
794        DME = LastUser.end(); DMI != DME; ++DMI) {
795    DenseMap<Pass *, SmallPtrSet<Pass *, 8> >::iterator InvDMI =
796      InversedLastUser.find(DMI->second);
797    if (InvDMI != InversedLastUser.end()) {
798      SmallPtrSet<Pass *, 8> &L = InvDMI->second;
799      L.insert(DMI->first);
800    } else {
801      SmallPtrSet<Pass *, 8> L; L.insert(DMI->first);
802      InversedLastUser[DMI->second] = L;
803    }
804  }
805}
806
807/// Destructor
808PMTopLevelManager::~PMTopLevelManager() {
809  for (SmallVectorImpl<PMDataManager *>::iterator I = PassManagers.begin(),
810         E = PassManagers.end(); I != E; ++I)
811    delete *I;
812
813  for (SmallVectorImpl<ImmutablePass *>::iterator
814         I = ImmutablePasses.begin(), E = ImmutablePasses.end(); I != E; ++I)
815    delete *I;
816
817  for (DenseMap<Pass *, AnalysisUsage *>::iterator DMI = AnUsageMap.begin(),
818         DME = AnUsageMap.end(); DMI != DME; ++DMI)
819    delete DMI->second;
820}
821
822//===----------------------------------------------------------------------===//
823// PMDataManager implementation
824
825/// Augement AvailableAnalysis by adding analysis made available by pass P.
826void PMDataManager::recordAvailableAnalysis(Pass *P) {
827  AnalysisID PI = P->getPassID();
828
829  AvailableAnalysis[PI] = P;
830
831  assert(!AvailableAnalysis.empty());
832
833  // This pass is the current implementation of all of the interfaces it
834  // implements as well.
835  const PassInfo *PInf = TPM->findAnalysisPassInfo(PI);
836  if (!PInf) return;
837  const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
838  for (unsigned i = 0, e = II.size(); i != e; ++i)
839    AvailableAnalysis[II[i]->getTypeInfo()] = P;
840}
841
842// Return true if P preserves high level analysis used by other
843// passes managed by this manager
844bool PMDataManager::preserveHigherLevelAnalysis(Pass *P) {
845  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
846  if (AnUsage->getPreservesAll())
847    return true;
848
849  const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
850  for (SmallVectorImpl<Pass *>::iterator I = HigherLevelAnalysis.begin(),
851         E = HigherLevelAnalysis.end(); I  != E; ++I) {
852    Pass *P1 = *I;
853    if (P1->getAsImmutablePass() == nullptr &&
854        std::find(PreservedSet.begin(), PreservedSet.end(),
855                  P1->getPassID()) ==
856           PreservedSet.end())
857      return false;
858  }
859
860  return true;
861}
862
863/// verifyPreservedAnalysis -- Verify analysis preserved by pass P.
864void PMDataManager::verifyPreservedAnalysis(Pass *P) {
865  // Don't do this unless assertions are enabled.
866#ifdef NDEBUG
867  return;
868#endif
869  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
870  const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
871
872  // Verify preserved analysis
873  for (AnalysisUsage::VectorType::const_iterator I = PreservedSet.begin(),
874         E = PreservedSet.end(); I != E; ++I) {
875    AnalysisID AID = *I;
876    if (Pass *AP = findAnalysisPass(AID, true)) {
877      TimeRegion PassTimer(getPassTimer(AP));
878      AP->verifyAnalysis();
879    }
880  }
881}
882
883/// Remove Analysis not preserved by Pass P
884void PMDataManager::removeNotPreservedAnalysis(Pass *P) {
885  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
886  if (AnUsage->getPreservesAll())
887    return;
888
889  const AnalysisUsage::VectorType &PreservedSet = AnUsage->getPreservedSet();
890  for (DenseMap<AnalysisID, Pass*>::iterator I = AvailableAnalysis.begin(),
891         E = AvailableAnalysis.end(); I != E; ) {
892    DenseMap<AnalysisID, Pass*>::iterator Info = I++;
893    if (Info->second->getAsImmutablePass() == nullptr &&
894        std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
895        PreservedSet.end()) {
896      // Remove this analysis
897      if (PassDebugging >= Details) {
898        Pass *S = Info->second;
899        dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
900        dbgs() << S->getPassName() << "'\n";
901      }
902      AvailableAnalysis.erase(Info);
903    }
904  }
905
906  // Check inherited analysis also. If P is not preserving analysis
907  // provided by parent manager then remove it here.
908  for (unsigned Index = 0; Index < PMT_Last; ++Index) {
909
910    if (!InheritedAnalysis[Index])
911      continue;
912
913    for (DenseMap<AnalysisID, Pass*>::iterator
914           I = InheritedAnalysis[Index]->begin(),
915           E = InheritedAnalysis[Index]->end(); I != E; ) {
916      DenseMap<AnalysisID, Pass *>::iterator Info = I++;
917      if (Info->second->getAsImmutablePass() == nullptr &&
918          std::find(PreservedSet.begin(), PreservedSet.end(), Info->first) ==
919             PreservedSet.end()) {
920        // Remove this analysis
921        if (PassDebugging >= Details) {
922          Pass *S = Info->second;
923          dbgs() << " -- '" <<  P->getPassName() << "' is not preserving '";
924          dbgs() << S->getPassName() << "'\n";
925        }
926        InheritedAnalysis[Index]->erase(Info);
927      }
928    }
929  }
930}
931
932/// Remove analysis passes that are not used any longer
933void PMDataManager::removeDeadPasses(Pass *P, StringRef Msg,
934                                     enum PassDebuggingString DBG_STR) {
935
936  SmallVector<Pass *, 12> DeadPasses;
937
938  // If this is a on the fly manager then it does not have TPM.
939  if (!TPM)
940    return;
941
942  TPM->collectLastUses(DeadPasses, P);
943
944  if (PassDebugging >= Details && !DeadPasses.empty()) {
945    dbgs() << " -*- '" <<  P->getPassName();
946    dbgs() << "' is the last user of following pass instances.";
947    dbgs() << " Free these instances\n";
948  }
949
950  for (SmallVectorImpl<Pass *>::iterator I = DeadPasses.begin(),
951         E = DeadPasses.end(); I != E; ++I)
952    freePass(*I, Msg, DBG_STR);
953}
954
955void PMDataManager::freePass(Pass *P, StringRef Msg,
956                             enum PassDebuggingString DBG_STR) {
957  dumpPassInfo(P, FREEING_MSG, DBG_STR, Msg);
958
959  {
960    // If the pass crashes releasing memory, remember this.
961    PassManagerPrettyStackEntry X(P);
962    TimeRegion PassTimer(getPassTimer(P));
963
964    P->releaseMemory();
965  }
966
967  AnalysisID PI = P->getPassID();
968  if (const PassInfo *PInf = TPM->findAnalysisPassInfo(PI)) {
969    // Remove the pass itself (if it is not already removed).
970    AvailableAnalysis.erase(PI);
971
972    // Remove all interfaces this pass implements, for which it is also
973    // listed as the available implementation.
974    const std::vector<const PassInfo*> &II = PInf->getInterfacesImplemented();
975    for (unsigned i = 0, e = II.size(); i != e; ++i) {
976      DenseMap<AnalysisID, Pass*>::iterator Pos =
977        AvailableAnalysis.find(II[i]->getTypeInfo());
978      if (Pos != AvailableAnalysis.end() && Pos->second == P)
979        AvailableAnalysis.erase(Pos);
980    }
981  }
982}
983
984/// Add pass P into the PassVector. Update
985/// AvailableAnalysis appropriately if ProcessAnalysis is true.
986void PMDataManager::add(Pass *P, bool ProcessAnalysis) {
987  // This manager is going to manage pass P. Set up analysis resolver
988  // to connect them.
989  AnalysisResolver *AR = new AnalysisResolver(*this);
990  P->setResolver(AR);
991
992  // If a FunctionPass F is the last user of ModulePass info M
993  // then the F's manager, not F, records itself as a last user of M.
994  SmallVector<Pass *, 12> TransferLastUses;
995
996  if (!ProcessAnalysis) {
997    // Add pass
998    PassVector.push_back(P);
999    return;
1000  }
1001
1002  // At the moment, this pass is the last user of all required passes.
1003  SmallVector<Pass *, 12> LastUses;
1004  SmallVector<Pass *, 8> RequiredPasses;
1005  SmallVector<AnalysisID, 8> ReqAnalysisNotAvailable;
1006
1007  unsigned PDepth = this->getDepth();
1008
1009  collectRequiredAnalysis(RequiredPasses,
1010                          ReqAnalysisNotAvailable, P);
1011  for (SmallVectorImpl<Pass *>::iterator I = RequiredPasses.begin(),
1012         E = RequiredPasses.end(); I != E; ++I) {
1013    Pass *PRequired = *I;
1014    unsigned RDepth = 0;
1015
1016    assert(PRequired->getResolver() && "Analysis Resolver is not set");
1017    PMDataManager &DM = PRequired->getResolver()->getPMDataManager();
1018    RDepth = DM.getDepth();
1019
1020    if (PDepth == RDepth)
1021      LastUses.push_back(PRequired);
1022    else if (PDepth > RDepth) {
1023      // Let the parent claim responsibility of last use
1024      TransferLastUses.push_back(PRequired);
1025      // Keep track of higher level analysis used by this manager.
1026      HigherLevelAnalysis.push_back(PRequired);
1027    } else
1028      llvm_unreachable("Unable to accommodate Required Pass");
1029  }
1030
1031  // Set P as P's last user until someone starts using P.
1032  // However, if P is a Pass Manager then it does not need
1033  // to record its last user.
1034  if (!P->getAsPMDataManager())
1035    LastUses.push_back(P);
1036  TPM->setLastUser(LastUses, P);
1037
1038  if (!TransferLastUses.empty()) {
1039    Pass *My_PM = getAsPass();
1040    TPM->setLastUser(TransferLastUses, My_PM);
1041    TransferLastUses.clear();
1042  }
1043
1044  // Now, take care of required analyses that are not available.
1045  for (SmallVectorImpl<AnalysisID>::iterator
1046         I = ReqAnalysisNotAvailable.begin(),
1047         E = ReqAnalysisNotAvailable.end() ;I != E; ++I) {
1048    const PassInfo *PI = TPM->findAnalysisPassInfo(*I);
1049    Pass *AnalysisPass = PI->createPass();
1050    this->addLowerLevelRequiredPass(P, AnalysisPass);
1051  }
1052
1053  // Take a note of analysis required and made available by this pass.
1054  // Remove the analysis not preserved by this pass
1055  removeNotPreservedAnalysis(P);
1056  recordAvailableAnalysis(P);
1057
1058  // Add pass
1059  PassVector.push_back(P);
1060}
1061
1062
1063/// Populate RP with analysis pass that are required by
1064/// pass P and are available. Populate RP_NotAvail with analysis
1065/// pass that are required by pass P but are not available.
1066void PMDataManager::collectRequiredAnalysis(SmallVectorImpl<Pass *> &RP,
1067                                       SmallVectorImpl<AnalysisID> &RP_NotAvail,
1068                                            Pass *P) {
1069  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
1070  const AnalysisUsage::VectorType &RequiredSet = AnUsage->getRequiredSet();
1071  for (AnalysisUsage::VectorType::const_iterator
1072         I = RequiredSet.begin(), E = RequiredSet.end(); I != E; ++I) {
1073    if (Pass *AnalysisPass = findAnalysisPass(*I, true))
1074      RP.push_back(AnalysisPass);
1075    else
1076      RP_NotAvail.push_back(*I);
1077  }
1078
1079  const AnalysisUsage::VectorType &IDs = AnUsage->getRequiredTransitiveSet();
1080  for (AnalysisUsage::VectorType::const_iterator I = IDs.begin(),
1081         E = IDs.end(); I != E; ++I) {
1082    if (Pass *AnalysisPass = findAnalysisPass(*I, true))
1083      RP.push_back(AnalysisPass);
1084    else
1085      RP_NotAvail.push_back(*I);
1086  }
1087}
1088
1089// All Required analyses should be available to the pass as it runs!  Here
1090// we fill in the AnalysisImpls member of the pass so that it can
1091// successfully use the getAnalysis() method to retrieve the
1092// implementations it needs.
1093//
1094void PMDataManager::initializeAnalysisImpl(Pass *P) {
1095  AnalysisUsage *AnUsage = TPM->findAnalysisUsage(P);
1096
1097  for (AnalysisUsage::VectorType::const_iterator
1098         I = AnUsage->getRequiredSet().begin(),
1099         E = AnUsage->getRequiredSet().end(); I != E; ++I) {
1100    Pass *Impl = findAnalysisPass(*I, true);
1101    if (!Impl)
1102      // This may be analysis pass that is initialized on the fly.
1103      // If that is not the case then it will raise an assert when it is used.
1104      continue;
1105    AnalysisResolver *AR = P->getResolver();
1106    assert(AR && "Analysis Resolver is not set");
1107    AR->addAnalysisImplsPair(*I, Impl);
1108  }
1109}
1110
1111/// Find the pass that implements Analysis AID. If desired pass is not found
1112/// then return NULL.
1113Pass *PMDataManager::findAnalysisPass(AnalysisID AID, bool SearchParent) {
1114
1115  // Check if AvailableAnalysis map has one entry.
1116  DenseMap<AnalysisID, Pass*>::const_iterator I =  AvailableAnalysis.find(AID);
1117
1118  if (I != AvailableAnalysis.end())
1119    return I->second;
1120
1121  // Search Parents through TopLevelManager
1122  if (SearchParent)
1123    return TPM->findAnalysisPass(AID);
1124
1125  return nullptr;
1126}
1127
1128// Print list of passes that are last used by P.
1129void PMDataManager::dumpLastUses(Pass *P, unsigned Offset) const{
1130
1131  SmallVector<Pass *, 12> LUses;
1132
1133  // If this is a on the fly manager then it does not have TPM.
1134  if (!TPM)
1135    return;
1136
1137  TPM->collectLastUses(LUses, P);
1138
1139  for (SmallVectorImpl<Pass *>::iterator I = LUses.begin(),
1140         E = LUses.end(); I != E; ++I) {
1141    dbgs() << "--" << std::string(Offset*2, ' ');
1142    (*I)->dumpPassStructure(0);
1143  }
1144}
1145
1146void PMDataManager::dumpPassArguments() const {
1147  for (SmallVectorImpl<Pass *>::const_iterator I = PassVector.begin(),
1148        E = PassVector.end(); I != E; ++I) {
1149    if (PMDataManager *PMD = (*I)->getAsPMDataManager())
1150      PMD->dumpPassArguments();
1151    else
1152      if (const PassInfo *PI =
1153            TPM->findAnalysisPassInfo((*I)->getPassID()))
1154        if (!PI->isAnalysisGroup())
1155          dbgs() << " -" << PI->getPassArgument();
1156  }
1157}
1158
1159void PMDataManager::dumpPassInfo(Pass *P, enum PassDebuggingString S1,
1160                                 enum PassDebuggingString S2,
1161                                 StringRef Msg) {
1162  if (PassDebugging < Executions)
1163    return;
1164  dbgs() << "[" << sys::TimeValue::now().str() << "] " << (void *)this
1165         << std::string(getDepth() * 2 + 1, ' ');
1166  switch (S1) {
1167  case EXECUTION_MSG:
1168    dbgs() << "Executing Pass '" << P->getPassName();
1169    break;
1170  case MODIFICATION_MSG:
1171    dbgs() << "Made Modification '" << P->getPassName();
1172    break;
1173  case FREEING_MSG:
1174    dbgs() << " Freeing Pass '" << P->getPassName();
1175    break;
1176  default:
1177    break;
1178  }
1179  switch (S2) {
1180  case ON_BASICBLOCK_MSG:
1181    dbgs() << "' on BasicBlock '" << Msg << "'...\n";
1182    break;
1183  case ON_FUNCTION_MSG:
1184    dbgs() << "' on Function '" << Msg << "'...\n";
1185    break;
1186  case ON_MODULE_MSG:
1187    dbgs() << "' on Module '"  << Msg << "'...\n";
1188    break;
1189  case ON_REGION_MSG:
1190    dbgs() << "' on Region '"  << Msg << "'...\n";
1191    break;
1192  case ON_LOOP_MSG:
1193    dbgs() << "' on Loop '" << Msg << "'...\n";
1194    break;
1195  case ON_CG_MSG:
1196    dbgs() << "' on Call Graph Nodes '" << Msg << "'...\n";
1197    break;
1198  default:
1199    break;
1200  }
1201}
1202
1203void PMDataManager::dumpRequiredSet(const Pass *P) const {
1204  if (PassDebugging < Details)
1205    return;
1206
1207  AnalysisUsage analysisUsage;
1208  P->getAnalysisUsage(analysisUsage);
1209  dumpAnalysisUsage("Required", P, analysisUsage.getRequiredSet());
1210}
1211
1212void PMDataManager::dumpPreservedSet(const Pass *P) const {
1213  if (PassDebugging < Details)
1214    return;
1215
1216  AnalysisUsage analysisUsage;
1217  P->getAnalysisUsage(analysisUsage);
1218  dumpAnalysisUsage("Preserved", P, analysisUsage.getPreservedSet());
1219}
1220
1221void PMDataManager::dumpAnalysisUsage(StringRef Msg, const Pass *P,
1222                                   const AnalysisUsage::VectorType &Set) const {
1223  assert(PassDebugging >= Details);
1224  if (Set.empty())
1225    return;
1226  dbgs() << (const void*)P << std::string(getDepth()*2+3, ' ') << Msg << " Analyses:";
1227  for (unsigned i = 0; i != Set.size(); ++i) {
1228    if (i) dbgs() << ',';
1229    const PassInfo *PInf = TPM->findAnalysisPassInfo(Set[i]);
1230    if (!PInf) {
1231      // Some preserved passes, such as AliasAnalysis, may not be initialized by
1232      // all drivers.
1233      dbgs() << " Uninitialized Pass";
1234      continue;
1235    }
1236    dbgs() << ' ' << PInf->getPassName();
1237  }
1238  dbgs() << '\n';
1239}
1240
1241/// Add RequiredPass into list of lower level passes required by pass P.
1242/// RequiredPass is run on the fly by Pass Manager when P requests it
1243/// through getAnalysis interface.
1244/// This should be handled by specific pass manager.
1245void PMDataManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
1246  if (TPM) {
1247    TPM->dumpArguments();
1248    TPM->dumpPasses();
1249  }
1250
1251  // Module Level pass may required Function Level analysis info
1252  // (e.g. dominator info). Pass manager uses on the fly function pass manager
1253  // to provide this on demand. In that case, in Pass manager terminology,
1254  // module level pass is requiring lower level analysis info managed by
1255  // lower level pass manager.
1256
1257  // When Pass manager is not able to order required analysis info, Pass manager
1258  // checks whether any lower level manager will be able to provide this
1259  // analysis info on demand or not.
1260#ifndef NDEBUG
1261  dbgs() << "Unable to schedule '" << RequiredPass->getPassName();
1262  dbgs() << "' required by '" << P->getPassName() << "'\n";
1263#endif
1264  llvm_unreachable("Unable to schedule pass");
1265}
1266
1267Pass *PMDataManager::getOnTheFlyPass(Pass *P, AnalysisID PI, Function &F) {
1268  llvm_unreachable("Unable to find on the fly pass");
1269}
1270
1271// Destructor
1272PMDataManager::~PMDataManager() {
1273  for (SmallVectorImpl<Pass *>::iterator I = PassVector.begin(),
1274         E = PassVector.end(); I != E; ++I)
1275    delete *I;
1276}
1277
1278//===----------------------------------------------------------------------===//
1279// NOTE: Is this the right place to define this method ?
1280// getAnalysisIfAvailable - Return analysis result or null if it doesn't exist.
1281Pass *AnalysisResolver::getAnalysisIfAvailable(AnalysisID ID, bool dir) const {
1282  return PM.findAnalysisPass(ID, dir);
1283}
1284
1285Pass *AnalysisResolver::findImplPass(Pass *P, AnalysisID AnalysisPI,
1286                                     Function &F) {
1287  return PM.getOnTheFlyPass(P, AnalysisPI, F);
1288}
1289
1290//===----------------------------------------------------------------------===//
1291// BBPassManager implementation
1292
1293/// Execute all of the passes scheduled for execution by invoking
1294/// runOnBasicBlock method.  Keep track of whether any of the passes modifies
1295/// the function, and if so, return true.
1296bool BBPassManager::runOnFunction(Function &F) {
1297  if (F.isDeclaration())
1298    return false;
1299
1300  bool Changed = doInitialization(F);
1301
1302  for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I)
1303    for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1304      BasicBlockPass *BP = getContainedPass(Index);
1305      bool LocalChanged = false;
1306
1307      dumpPassInfo(BP, EXECUTION_MSG, ON_BASICBLOCK_MSG, I->getName());
1308      dumpRequiredSet(BP);
1309
1310      initializeAnalysisImpl(BP);
1311
1312      {
1313        // If the pass crashes, remember this.
1314        PassManagerPrettyStackEntry X(BP, *I);
1315        TimeRegion PassTimer(getPassTimer(BP));
1316
1317        LocalChanged |= BP->runOnBasicBlock(*I);
1318      }
1319
1320      Changed |= LocalChanged;
1321      if (LocalChanged)
1322        dumpPassInfo(BP, MODIFICATION_MSG, ON_BASICBLOCK_MSG,
1323                     I->getName());
1324      dumpPreservedSet(BP);
1325
1326      verifyPreservedAnalysis(BP);
1327      removeNotPreservedAnalysis(BP);
1328      recordAvailableAnalysis(BP);
1329      removeDeadPasses(BP, I->getName(), ON_BASICBLOCK_MSG);
1330    }
1331
1332  return doFinalization(F) || Changed;
1333}
1334
1335// Implement doInitialization and doFinalization
1336bool BBPassManager::doInitialization(Module &M) {
1337  bool Changed = false;
1338
1339  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1340    Changed |= getContainedPass(Index)->doInitialization(M);
1341
1342  return Changed;
1343}
1344
1345bool BBPassManager::doFinalization(Module &M) {
1346  bool Changed = false;
1347
1348  for (int Index = getNumContainedPasses() - 1; Index >= 0; --Index)
1349    Changed |= getContainedPass(Index)->doFinalization(M);
1350
1351  return Changed;
1352}
1353
1354bool BBPassManager::doInitialization(Function &F) {
1355  bool Changed = false;
1356
1357  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1358    BasicBlockPass *BP = getContainedPass(Index);
1359    Changed |= BP->doInitialization(F);
1360  }
1361
1362  return Changed;
1363}
1364
1365bool BBPassManager::doFinalization(Function &F) {
1366  bool Changed = false;
1367
1368  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1369    BasicBlockPass *BP = getContainedPass(Index);
1370    Changed |= BP->doFinalization(F);
1371  }
1372
1373  return Changed;
1374}
1375
1376
1377//===----------------------------------------------------------------------===//
1378// FunctionPassManager implementation
1379
1380/// Create new Function pass manager
1381FunctionPassManager::FunctionPassManager(Module *m) : M(m) {
1382  FPM = new FunctionPassManagerImpl();
1383  // FPM is the top level manager.
1384  FPM->setTopLevelManager(FPM);
1385
1386  AnalysisResolver *AR = new AnalysisResolver(*FPM);
1387  FPM->setResolver(AR);
1388}
1389
1390FunctionPassManager::~FunctionPassManager() {
1391  delete FPM;
1392}
1393
1394void FunctionPassManager::add(Pass *P) {
1395  FPM->add(P);
1396}
1397
1398/// run - Execute all of the passes scheduled for execution.  Keep
1399/// track of whether any of the passes modifies the function, and if
1400/// so, return true.
1401///
1402bool FunctionPassManager::run(Function &F) {
1403  if (std::error_code EC = F.materialize())
1404    report_fatal_error("Error reading bitcode file: " + EC.message());
1405  return FPM->run(F);
1406}
1407
1408
1409/// doInitialization - Run all of the initializers for the function passes.
1410///
1411bool FunctionPassManager::doInitialization() {
1412  return FPM->doInitialization(*M);
1413}
1414
1415/// doFinalization - Run all of the finalizers for the function passes.
1416///
1417bool FunctionPassManager::doFinalization() {
1418  return FPM->doFinalization(*M);
1419}
1420
1421//===----------------------------------------------------------------------===//
1422// FunctionPassManagerImpl implementation
1423//
1424bool FunctionPassManagerImpl::doInitialization(Module &M) {
1425  bool Changed = false;
1426
1427  dumpArguments();
1428  dumpPasses();
1429
1430  SmallVectorImpl<ImmutablePass *>& IPV = getImmutablePasses();
1431  for (SmallVectorImpl<ImmutablePass *>::const_iterator I = IPV.begin(),
1432       E = IPV.end(); I != E; ++I) {
1433    Changed |= (*I)->doInitialization(M);
1434  }
1435
1436  for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1437    Changed |= getContainedManager(Index)->doInitialization(M);
1438
1439  return Changed;
1440}
1441
1442bool FunctionPassManagerImpl::doFinalization(Module &M) {
1443  bool Changed = false;
1444
1445  for (int Index = getNumContainedManagers() - 1; Index >= 0; --Index)
1446    Changed |= getContainedManager(Index)->doFinalization(M);
1447
1448  SmallVectorImpl<ImmutablePass *>& IPV = getImmutablePasses();
1449  for (SmallVectorImpl<ImmutablePass *>::const_iterator I = IPV.begin(),
1450       E = IPV.end(); I != E; ++I) {
1451    Changed |= (*I)->doFinalization(M);
1452  }
1453
1454  return Changed;
1455}
1456
1457/// cleanup - After running all passes, clean up pass manager cache.
1458void FPPassManager::cleanup() {
1459 for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1460    FunctionPass *FP = getContainedPass(Index);
1461    AnalysisResolver *AR = FP->getResolver();
1462    assert(AR && "Analysis Resolver is not set");
1463    AR->clearAnalysisImpls();
1464 }
1465}
1466
1467void FunctionPassManagerImpl::releaseMemoryOnTheFly() {
1468  if (!wasRun)
1469    return;
1470  for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) {
1471    FPPassManager *FPPM = getContainedManager(Index);
1472    for (unsigned Index = 0; Index < FPPM->getNumContainedPasses(); ++Index) {
1473      FPPM->getContainedPass(Index)->releaseMemory();
1474    }
1475  }
1476  wasRun = false;
1477}
1478
1479// Execute all the passes managed by this top level manager.
1480// Return true if any function is modified by a pass.
1481bool FunctionPassManagerImpl::run(Function &F) {
1482  bool Changed = false;
1483  TimingInfo::createTheTimeInfo();
1484
1485  initializeAllAnalysisInfo();
1486  for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) {
1487    Changed |= getContainedManager(Index)->runOnFunction(F);
1488    F.getContext().yield();
1489  }
1490
1491  for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index)
1492    getContainedManager(Index)->cleanup();
1493
1494  wasRun = true;
1495  return Changed;
1496}
1497
1498//===----------------------------------------------------------------------===//
1499// FPPassManager implementation
1500
1501char FPPassManager::ID = 0;
1502/// Print passes managed by this manager
1503void FPPassManager::dumpPassStructure(unsigned Offset) {
1504  dbgs().indent(Offset*2) << "FunctionPass Manager\n";
1505  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1506    FunctionPass *FP = getContainedPass(Index);
1507    FP->dumpPassStructure(Offset + 1);
1508    dumpLastUses(FP, Offset+1);
1509  }
1510}
1511
1512
1513/// Execute all of the passes scheduled for execution by invoking
1514/// runOnFunction method.  Keep track of whether any of the passes modifies
1515/// the function, and if so, return true.
1516bool FPPassManager::runOnFunction(Function &F) {
1517  if (F.isDeclaration())
1518    return false;
1519
1520  bool Changed = false;
1521
1522  // Collect inherited analysis from Module level pass manager.
1523  populateInheritedAnalysis(TPM->activeStack);
1524
1525  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1526    FunctionPass *FP = getContainedPass(Index);
1527    bool LocalChanged = false;
1528
1529    dumpPassInfo(FP, EXECUTION_MSG, ON_FUNCTION_MSG, F.getName());
1530    dumpRequiredSet(FP);
1531
1532    initializeAnalysisImpl(FP);
1533
1534    {
1535      PassManagerPrettyStackEntry X(FP, F);
1536      TimeRegion PassTimer(getPassTimer(FP));
1537
1538      LocalChanged |= FP->runOnFunction(F);
1539    }
1540
1541    Changed |= LocalChanged;
1542    if (LocalChanged)
1543      dumpPassInfo(FP, MODIFICATION_MSG, ON_FUNCTION_MSG, F.getName());
1544    dumpPreservedSet(FP);
1545
1546    verifyPreservedAnalysis(FP);
1547    removeNotPreservedAnalysis(FP);
1548    recordAvailableAnalysis(FP);
1549    removeDeadPasses(FP, F.getName(), ON_FUNCTION_MSG);
1550  }
1551  return Changed;
1552}
1553
1554bool FPPassManager::runOnModule(Module &M) {
1555  bool Changed = false;
1556
1557  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
1558    Changed |= runOnFunction(*I);
1559
1560  return Changed;
1561}
1562
1563bool FPPassManager::doInitialization(Module &M) {
1564  bool Changed = false;
1565
1566  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1567    Changed |= getContainedPass(Index)->doInitialization(M);
1568
1569  return Changed;
1570}
1571
1572bool FPPassManager::doFinalization(Module &M) {
1573  bool Changed = false;
1574
1575  for (int Index = getNumContainedPasses() - 1; Index >= 0; --Index)
1576    Changed |= getContainedPass(Index)->doFinalization(M);
1577
1578  return Changed;
1579}
1580
1581//===----------------------------------------------------------------------===//
1582// MPPassManager implementation
1583
1584/// Execute all of the passes scheduled for execution by invoking
1585/// runOnModule method.  Keep track of whether any of the passes modifies
1586/// the module, and if so, return true.
1587bool
1588MPPassManager::runOnModule(Module &M) {
1589  bool Changed = false;
1590
1591  // Initialize on-the-fly passes
1592  for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
1593       I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
1594       I != E; ++I) {
1595    FunctionPassManagerImpl *FPP = I->second;
1596    Changed |= FPP->doInitialization(M);
1597  }
1598
1599  // Initialize module passes
1600  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index)
1601    Changed |= getContainedPass(Index)->doInitialization(M);
1602
1603  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {
1604    ModulePass *MP = getContainedPass(Index);
1605    bool LocalChanged = false;
1606
1607    dumpPassInfo(MP, EXECUTION_MSG, ON_MODULE_MSG, M.getModuleIdentifier());
1608    dumpRequiredSet(MP);
1609
1610    initializeAnalysisImpl(MP);
1611
1612    {
1613      PassManagerPrettyStackEntry X(MP, M);
1614      TimeRegion PassTimer(getPassTimer(MP));
1615
1616      LocalChanged |= MP->runOnModule(M);
1617    }
1618
1619    Changed |= LocalChanged;
1620    if (LocalChanged)
1621      dumpPassInfo(MP, MODIFICATION_MSG, ON_MODULE_MSG,
1622                   M.getModuleIdentifier());
1623    dumpPreservedSet(MP);
1624
1625    verifyPreservedAnalysis(MP);
1626    removeNotPreservedAnalysis(MP);
1627    recordAvailableAnalysis(MP);
1628    removeDeadPasses(MP, M.getModuleIdentifier(), ON_MODULE_MSG);
1629  }
1630
1631  // Finalize module passes
1632  for (int Index = getNumContainedPasses() - 1; Index >= 0; --Index)
1633    Changed |= getContainedPass(Index)->doFinalization(M);
1634
1635  // Finalize on-the-fly passes
1636  for (std::map<Pass *, FunctionPassManagerImpl *>::iterator
1637       I = OnTheFlyManagers.begin(), E = OnTheFlyManagers.end();
1638       I != E; ++I) {
1639    FunctionPassManagerImpl *FPP = I->second;
1640    // We don't know when is the last time an on-the-fly pass is run,
1641    // so we need to releaseMemory / finalize here
1642    FPP->releaseMemoryOnTheFly();
1643    Changed |= FPP->doFinalization(M);
1644  }
1645
1646  return Changed;
1647}
1648
1649/// Add RequiredPass into list of lower level passes required by pass P.
1650/// RequiredPass is run on the fly by Pass Manager when P requests it
1651/// through getAnalysis interface.
1652void MPPassManager::addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass) {
1653  assert(P->getPotentialPassManagerType() == PMT_ModulePassManager &&
1654         "Unable to handle Pass that requires lower level Analysis pass");
1655  assert((P->getPotentialPassManagerType() <
1656          RequiredPass->getPotentialPassManagerType()) &&
1657         "Unable to handle Pass that requires lower level Analysis pass");
1658  if (!RequiredPass)
1659    return;
1660
1661  FunctionPassManagerImpl *FPP = OnTheFlyManagers[P];
1662  if (!FPP) {
1663    FPP = new FunctionPassManagerImpl();
1664    // FPP is the top level manager.
1665    FPP->setTopLevelManager(FPP);
1666
1667    OnTheFlyManagers[P] = FPP;
1668  }
1669  const PassInfo *RequiredPassPI =
1670      TPM->findAnalysisPassInfo(RequiredPass->getPassID());
1671
1672  Pass *FoundPass = nullptr;
1673  if (RequiredPassPI && RequiredPassPI->isAnalysis()) {
1674    FoundPass =
1675      ((PMTopLevelManager*)FPP)->findAnalysisPass(RequiredPass->getPassID());
1676  }
1677  if (!FoundPass) {
1678    FoundPass = RequiredPass;
1679    // This should be guaranteed to add RequiredPass to the passmanager given
1680    // that we checked for an available analysis above.
1681    FPP->add(RequiredPass);
1682  }
1683  // Register P as the last user of FoundPass or RequiredPass.
1684  SmallVector<Pass *, 1> LU;
1685  LU.push_back(FoundPass);
1686  FPP->setLastUser(LU,  P);
1687}
1688
1689/// Return function pass corresponding to PassInfo PI, that is
1690/// required by module pass MP. Instantiate analysis pass, by using
1691/// its runOnFunction() for function F.
1692Pass* MPPassManager::getOnTheFlyPass(Pass *MP, AnalysisID PI, Function &F){
1693  FunctionPassManagerImpl *FPP = OnTheFlyManagers[MP];
1694  assert(FPP && "Unable to find on the fly pass");
1695
1696  FPP->releaseMemoryOnTheFly();
1697  FPP->run(F);
1698  return ((PMTopLevelManager*)FPP)->findAnalysisPass(PI);
1699}
1700
1701
1702//===----------------------------------------------------------------------===//
1703// PassManagerImpl implementation
1704
1705//
1706/// run - Execute all of the passes scheduled for execution.  Keep track of
1707/// whether any of the passes modifies the module, and if so, return true.
1708bool PassManagerImpl::run(Module &M) {
1709  bool Changed = false;
1710  TimingInfo::createTheTimeInfo();
1711
1712  dumpArguments();
1713  dumpPasses();
1714
1715  SmallVectorImpl<ImmutablePass *>& IPV = getImmutablePasses();
1716  for (SmallVectorImpl<ImmutablePass *>::const_iterator I = IPV.begin(),
1717       E = IPV.end(); I != E; ++I) {
1718    Changed |= (*I)->doInitialization(M);
1719  }
1720
1721  initializeAllAnalysisInfo();
1722  for (unsigned Index = 0; Index < getNumContainedManagers(); ++Index) {
1723    Changed |= getContainedManager(Index)->runOnModule(M);
1724    M.getContext().yield();
1725  }
1726
1727  for (SmallVectorImpl<ImmutablePass *>::const_iterator I = IPV.begin(),
1728       E = IPV.end(); I != E; ++I) {
1729    Changed |= (*I)->doFinalization(M);
1730  }
1731
1732  return Changed;
1733}
1734
1735//===----------------------------------------------------------------------===//
1736// PassManager implementation
1737
1738/// Create new pass manager
1739PassManager::PassManager() {
1740  PM = new PassManagerImpl();
1741  // PM is the top level manager
1742  PM->setTopLevelManager(PM);
1743}
1744
1745PassManager::~PassManager() {
1746  delete PM;
1747}
1748
1749void PassManager::add(Pass *P) {
1750  PM->add(P);
1751}
1752
1753/// run - Execute all of the passes scheduled for execution.  Keep track of
1754/// whether any of the passes modifies the module, and if so, return true.
1755bool PassManager::run(Module &M) {
1756  return PM->run(M);
1757}
1758
1759//===----------------------------------------------------------------------===//
1760// TimingInfo implementation
1761
1762bool llvm::TimePassesIsEnabled = false;
1763static cl::opt<bool,true>
1764EnableTiming("time-passes", cl::location(TimePassesIsEnabled),
1765            cl::desc("Time each pass, printing elapsed time for each on exit"));
1766
1767// createTheTimeInfo - This method either initializes the TheTimeInfo pointer to
1768// a non-null value (if the -time-passes option is enabled) or it leaves it
1769// null.  It may be called multiple times.
1770void TimingInfo::createTheTimeInfo() {
1771  if (!TimePassesIsEnabled || TheTimeInfo) return;
1772
1773  // Constructed the first time this is called, iff -time-passes is enabled.
1774  // This guarantees that the object will be constructed before static globals,
1775  // thus it will be destroyed before them.
1776  static ManagedStatic<TimingInfo> TTI;
1777  TheTimeInfo = &*TTI;
1778}
1779
1780/// If TimingInfo is enabled then start pass timer.
1781Timer *llvm::getPassTimer(Pass *P) {
1782  if (TheTimeInfo)
1783    return TheTimeInfo->getPassTimer(P);
1784  return nullptr;
1785}
1786
1787//===----------------------------------------------------------------------===//
1788// PMStack implementation
1789//
1790
1791// Pop Pass Manager from the stack and clear its analysis info.
1792void PMStack::pop() {
1793
1794  PMDataManager *Top = this->top();
1795  Top->initializeAnalysisInfo();
1796
1797  S.pop_back();
1798}
1799
1800// Push PM on the stack and set its top level manager.
1801void PMStack::push(PMDataManager *PM) {
1802  assert(PM && "Unable to push. Pass Manager expected");
1803  assert(PM->getDepth()==0 && "Pass Manager depth set too early");
1804
1805  if (!this->empty()) {
1806    assert(PM->getPassManagerType() > this->top()->getPassManagerType()
1807           && "pushing bad pass manager to PMStack");
1808    PMTopLevelManager *TPM = this->top()->getTopLevelManager();
1809
1810    assert(TPM && "Unable to find top level manager");
1811    TPM->addIndirectPassManager(PM);
1812    PM->setTopLevelManager(TPM);
1813    PM->setDepth(this->top()->getDepth()+1);
1814  } else {
1815    assert((PM->getPassManagerType() == PMT_ModulePassManager
1816           || PM->getPassManagerType() == PMT_FunctionPassManager)
1817           && "pushing bad pass manager to PMStack");
1818    PM->setDepth(1);
1819  }
1820
1821  S.push_back(PM);
1822}
1823
1824// Dump content of the pass manager stack.
1825void PMStack::dump() const {
1826  for (std::vector<PMDataManager *>::const_iterator I = S.begin(),
1827         E = S.end(); I != E; ++I)
1828    dbgs() << (*I)->getAsPass()->getPassName() << ' ';
1829
1830  if (!S.empty())
1831    dbgs() << '\n';
1832}
1833
1834/// Find appropriate Module Pass Manager in the PM Stack and
1835/// add self into that manager.
1836void ModulePass::assignPassManager(PMStack &PMS,
1837                                   PassManagerType PreferredType) {
1838  // Find Module Pass Manager
1839  while (!PMS.empty()) {
1840    PassManagerType TopPMType = PMS.top()->getPassManagerType();
1841    if (TopPMType == PreferredType)
1842      break; // We found desired pass manager
1843    else if (TopPMType > PMT_ModulePassManager)
1844      PMS.pop();    // Pop children pass managers
1845    else
1846      break;
1847  }
1848  assert(!PMS.empty() && "Unable to find appropriate Pass Manager");
1849  PMS.top()->add(this);
1850}
1851
1852/// Find appropriate Function Pass Manager or Call Graph Pass Manager
1853/// in the PM Stack and add self into that manager.
1854void FunctionPass::assignPassManager(PMStack &PMS,
1855                                     PassManagerType PreferredType) {
1856
1857  // Find Function Pass Manager
1858  while (!PMS.empty()) {
1859    if (PMS.top()->getPassManagerType() > PMT_FunctionPassManager)
1860      PMS.pop();
1861    else
1862      break;
1863  }
1864
1865  // Create new Function Pass Manager if needed.
1866  FPPassManager *FPP;
1867  if (PMS.top()->getPassManagerType() == PMT_FunctionPassManager) {
1868    FPP = (FPPassManager *)PMS.top();
1869  } else {
1870    assert(!PMS.empty() && "Unable to create Function Pass Manager");
1871    PMDataManager *PMD = PMS.top();
1872
1873    // [1] Create new Function Pass Manager
1874    FPP = new FPPassManager();
1875    FPP->populateInheritedAnalysis(PMS);
1876
1877    // [2] Set up new manager's top level manager
1878    PMTopLevelManager *TPM = PMD->getTopLevelManager();
1879    TPM->addIndirectPassManager(FPP);
1880
1881    // [3] Assign manager to manage this new manager. This may create
1882    // and push new managers into PMS
1883    FPP->assignPassManager(PMS, PMD->getPassManagerType());
1884
1885    // [4] Push new manager into PMS
1886    PMS.push(FPP);
1887  }
1888
1889  // Assign FPP as the manager of this pass.
1890  FPP->add(this);
1891}
1892
1893/// Find appropriate Basic Pass Manager or Call Graph Pass Manager
1894/// in the PM Stack and add self into that manager.
1895void BasicBlockPass::assignPassManager(PMStack &PMS,
1896                                       PassManagerType PreferredType) {
1897  BBPassManager *BBP;
1898
1899  // Basic Pass Manager is a leaf pass manager. It does not handle
1900  // any other pass manager.
1901  if (!PMS.empty() &&
1902      PMS.top()->getPassManagerType() == PMT_BasicBlockPassManager) {
1903    BBP = (BBPassManager *)PMS.top();
1904  } else {
1905    // If leaf manager is not Basic Block Pass manager then create new
1906    // basic Block Pass manager.
1907    assert(!PMS.empty() && "Unable to create BasicBlock Pass Manager");
1908    PMDataManager *PMD = PMS.top();
1909
1910    // [1] Create new Basic Block Manager
1911    BBP = new BBPassManager();
1912
1913    // [2] Set up new manager's top level manager
1914    // Basic Block Pass Manager does not live by itself
1915    PMTopLevelManager *TPM = PMD->getTopLevelManager();
1916    TPM->addIndirectPassManager(BBP);
1917
1918    // [3] Assign manager to manage this new manager. This may create
1919    // and push new managers into PMS
1920    BBP->assignPassManager(PMS, PreferredType);
1921
1922    // [4] Push new manager into PMS
1923    PMS.push(BBP);
1924  }
1925
1926  // Assign BBP as the manager of this pass.
1927  BBP->add(this);
1928}
1929
1930PassManagerBase::~PassManagerBase() {}
1931