text: //===- llvm/PassManagers.h - Pass Infrastructure classes  -------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  // This file declares the LLVM Pass Manager infrastructure. 
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_PASSMANAGERS_H
  #define LLVM_PASSMANAGERS_H
  
  #include "llvm/Pass.h"
  #include "llvm/ADT/SmallVector.h"
  #include "llvm/ADT/SmallPtrSet.h"
  #include "llvm/ADT/DenseMap.h"
  #include <vector>
  #include <map>
  
  //===----------------------------------------------------------------------===//
  // Overview:
  // The Pass Manager Infrastructure manages passes. It's responsibilities are:
  // 
  //   o Manage optimization pass execution order
  //   o Make required Analysis information available before pass P is run
  //   o Release memory occupied by dead passes
  //   o If Analysis information is dirtied by a pass then regenerate Analysis 
  //     information before it is consumed by another pass.
  //
  // Pass Manager Infrastructure uses multiple pass managers.  They are
  // PassManager, FunctionPassManager, MPPassManager, FPPassManager, BBPassManager.
  // This class hierarchy uses multiple inheritance but pass managers do not
  // derive from another pass manager.
  //
  // PassManager and FunctionPassManager are two top-level pass manager that
  // represents the external interface of this entire pass manager infrastructure.
  //
  // Important classes :
  //
  // [o] class PMTopLevelManager;
  //
  // Two top level managers, PassManager and FunctionPassManager, derive from 
  // PMTopLevelManager. PMTopLevelManager manages information used by top level 
  // managers such as last user info.
  //
  // [o] class PMDataManager;
  //
  // PMDataManager manages information, e.g. list of available analysis info, 
  // used by a pass manager to manage execution order of passes. It also provides
  // a place to implement common pass manager APIs. All pass managers derive from
  // PMDataManager.
  //
  // [o] class BBPassManager : public FunctionPass, public PMDataManager;
  //
  // BBPassManager manages BasicBlockPasses.
  //
  // [o] class FunctionPassManager;
  //
  // This is a external interface used by JIT to manage FunctionPasses. This
  // interface relies on FunctionPassManagerImpl to do all the tasks.
  //
  // [o] class FunctionPassManagerImpl : public ModulePass, PMDataManager,
  //                                     public PMTopLevelManager;
  //
  // FunctionPassManagerImpl is a top level manager. It manages FPPassManagers
  //
  // [o] class FPPassManager : public ModulePass, public PMDataManager;
  //
  // FPPassManager manages FunctionPasses and BBPassManagers
  //
  // [o] class MPPassManager : public Pass, public PMDataManager;
  //
  // MPPassManager manages ModulePasses and FPPassManagers
  //
  // [o] class PassManager;
  //
  // This is a external interface used by various tools to manages passes. It
  // relies on PassManagerImpl to do all the tasks.
  //
  // [o] class PassManagerImpl : public Pass, public PMDataManager,
  //                             public PMDTopLevelManager
  //
  // PassManagerImpl is a top level pass manager responsible for managing
  // MPPassManagers.
  //===----------------------------------------------------------------------===//
  
  #include "llvm/Support/PrettyStackTrace.h"
  
  namespace llvm {
    class Module;
    class Pass;
    class StringRef;
    class Value;
    class Timer;
    class PMDataManager;
  
  // enums for debugging strings
  enum PassDebuggingString {
    EXECUTION_MSG, // "Executing Pass '"
    MODIFICATION_MSG, // "' Made Modification '"
    FREEING_MSG, // " Freeing Pass '"
    ON_BASICBLOCK_MSG, // "'  on BasicBlock '" + PassName + "'...\n"
    ON_FUNCTION_MSG, // "' on Function '" + FunctionName + "'...\n"
    ON_MODULE_MSG, // "' on Module '" + ModuleName + "'...\n"
    ON_LOOP_MSG, // " 'on Loop ...\n'"
    ON_CG_MSG // "' on Call Graph ...\n'"
  };  
  
  /// PassManagerPrettyStackEntry - This is used to print informative information
  /// about what pass is running when/if a stack trace is generated.
  class PassManagerPrettyStackEntry : public PrettyStackTraceEntry {
    Pass *P;
    Value *V;
    Module *M;
  public:
    explicit PassManagerPrettyStackEntry(Pass *p)
      : P(p), V(0), M(0) {}  // When P is releaseMemory'd.
    PassManagerPrettyStackEntry(Pass *p, Value &v)
      : P(p), V(&v), M(0) {} // When P is run on V
    PassManagerPrettyStackEntry(Pass *p, Module &m)
      : P(p), V(0), M(&m) {} // When P is run on M
    
    /// print - Emit information about this stack frame to OS.
    virtual void print(raw_ostream &OS) const;
  };
    
    
  //===----------------------------------------------------------------------===//
  // PMStack
  //
  /// PMStack - This class implements a stack data structure of PMDataManager
  /// pointers.
  ///
  /// Top level pass managers (see PassManager.cpp) maintain active Pass Managers 
  /// using PMStack. Each Pass implements assignPassManager() to connect itself
  /// with appropriate manager. assignPassManager() walks PMStack to find
  /// suitable manager.
  class PMStack {
  public:
    typedef std::vector<PMDataManager *>::const_reverse_iterator iterator;
    iterator begin() const { return S.rbegin(); }
    iterator end() const { return S.rend(); }
  
    void pop();
    PMDataManager *top() const { return S.back(); }
    void push(PMDataManager *PM);
    bool empty() const { return S.empty(); }
  
    void dump() const;
  
  private:
    std::vector<PMDataManager *> S;
  };
  
  
  //===----------------------------------------------------------------------===//
  // PMTopLevelManager
  //
  /// PMTopLevelManager manages LastUser info and collects common APIs used by
  /// top level pass managers.
  class PMTopLevelManager {
  protected:
    explicit PMTopLevelManager(PMDataManager *PMDM);
  
    virtual unsigned getNumContainedManagers() const {
      return (unsigned)PassManagers.size();
    }
  
    void initializeAllAnalysisInfo();
  
  private:
    /// This is implemented by top level pass manager and used by 
    /// schedulePass() to add analysis info passes that are not available.
    virtual void addTopLevelPass(Pass  *P) = 0;
  
  public:
    /// Schedule pass P for execution. Make sure that passes required by
    /// P are run before P is run. Update analysis info maintained by
    /// the manager. Remove dead passes. This is a recursive function.
    void schedulePass(Pass *P);
  
    /// Set pass P as the last user of the given analysis passes.
    void setLastUser(SmallVector<Pass *, 12> &AnalysisPasses, Pass *P);
  
    /// Collect passes whose last user is P
    void collectLastUses(SmallVector<Pass *, 12> &LastUses, Pass *P);
  
    /// Find the pass that implements Analysis AID. Search immutable
    /// passes and all pass managers. If desired pass is not found
    /// then return NULL.
    Pass *findAnalysisPass(AnalysisID AID);
  
    /// Find analysis usage information for the pass P.
    AnalysisUsage *findAnalysisUsage(Pass *P);
  
    virtual ~PMTopLevelManager(); 
  
    /// Add immutable pass and initialize it.
    inline void addImmutablePass(ImmutablePass *P) {
      P->initializePass();
      ImmutablePasses.push_back(P);
    }
  
    inline SmallVector<ImmutablePass *, 8>& getImmutablePasses() {
      return ImmutablePasses;
    }
  
    void addPassManager(PMDataManager *Manager) {
      PassManagers.push_back(Manager);
    }
  
    // Add Manager into the list of managers that are not directly
    // maintained by this top level pass manager
    inline void addIndirectPassManager(PMDataManager *Manager) {
      IndirectPassManagers.push_back(Manager);
    }
  
    // Print passes managed by this top level manager.
    void dumpPasses() const;
    void dumpArguments() const;
  
    // Active Pass Managers
    PMStack activeStack;
  
  protected:
    
    /// Collection of pass managers
    SmallVector<PMDataManager *, 8> PassManagers;
  
  private:
  
    /// Collection of pass managers that are not directly maintained
    /// by this pass manager
    SmallVector<PMDataManager *, 8> IndirectPassManagers;
  
    // Map to keep track of last user of the analysis pass.
    // LastUser->second is the last user of Lastuser->first.
    DenseMap<Pass *, Pass *> LastUser;
  
    // Map to keep track of passes that are last used by a pass.
    // This inverse map is initialized at PM->run() based on
    // LastUser map.
    DenseMap<Pass *, SmallPtrSet<Pass *, 8> > InversedLastUser;
  
    /// Immutable passes are managed by top level manager.
    SmallVector<ImmutablePass *, 8> ImmutablePasses;
  
    DenseMap<Pass *, AnalysisUsage *> AnUsageMap;
  };
  
  
    
  //===----------------------------------------------------------------------===//
  // PMDataManager
  
  /// PMDataManager provides the common place to manage the analysis data
  /// used by pass managers.
  class PMDataManager {
  public:
  
    explicit PMDataManager(int Depth) : TPM(NULL), Depth(Depth) {
      initializeAnalysisInfo();
    }
  
    virtual ~PMDataManager();
    
    virtual Pass *getAsPass() = 0;
  
    /// Augment AvailableAnalysis by adding analysis made available by pass P.
    void recordAvailableAnalysis(Pass *P);
  
    /// verifyPreservedAnalysis -- Verify analysis presreved by pass P.
    void verifyPreservedAnalysis(Pass *P);
  
    /// Remove Analysis that is not preserved by the pass
    void removeNotPreservedAnalysis(Pass *P);
    
    /// Remove dead passes used by P.
    void removeDeadPasses(Pass *P, StringRef Msg, 
                          enum PassDebuggingString);
  
    /// Remove P.
    void freePass(Pass *P, StringRef Msg, 
                  enum PassDebuggingString);
  
    /// Add pass P into the PassVector. Update 
    /// AvailableAnalysis appropriately if ProcessAnalysis is true.
    void add(Pass *P, bool ProcessAnalysis = true);
  
    /// Add RequiredPass into list of lower level passes required by pass P.
    /// RequiredPass is run on the fly by Pass Manager when P requests it
    /// through getAnalysis interface.
    virtual void addLowerLevelRequiredPass(Pass *P, Pass *RequiredPass);
  
    virtual Pass *getOnTheFlyPass(Pass *P, AnalysisID PI, Function &F);
  
    /// Initialize available analysis information.
    void initializeAnalysisInfo() { 
      AvailableAnalysis.clear();
      for (unsigned i = 0; i < PMT_Last; ++i)
        InheritedAnalysis[i] = NULL;
    }
  
    // Return true if P preserves high level analysis used by other
    // passes that are managed by this manager.
    bool preserveHigherLevelAnalysis(Pass *P);
  
  
    /// Populate RequiredPasses with analysis pass that are required by
    /// pass P and are available. Populate ReqPassNotAvailable with analysis
    /// pass that are required by pass P but are not available.
    void collectRequiredAnalysis(SmallVector<Pass *, 8> &RequiredPasses,
                                 SmallVector<AnalysisID, 8> &ReqPassNotAvailable,
                                 Pass *P);
  
    /// All Required analyses should be available to the pass as it runs!  Here
    /// we fill in the AnalysisImpls member of the pass so that it can
    /// successfully use the getAnalysis() method to retrieve the
    /// implementations it needs.
    void initializeAnalysisImpl(Pass *P);
  
    /// Find the pass that implements Analysis AID. If desired pass is not found
    /// then return NULL.
    Pass *findAnalysisPass(AnalysisID AID, bool Direction);
  
    // Access toplevel manager
    PMTopLevelManager *getTopLevelManager() { return TPM; }
    void setTopLevelManager(PMTopLevelManager *T) { TPM = T; }
  
    unsigned getDepth() const { return Depth; }
  
    // Print routines used by debug-pass
    void dumpLastUses(Pass *P, unsigned Offset) const;
    void dumpPassArguments() const;
    void dumpPassInfo(Pass *P, enum PassDebuggingString S1,
                      enum PassDebuggingString S2, StringRef Msg);
    void dumpRequiredSet(const Pass *P) const;
    void dumpPreservedSet(const Pass *P) const;
  
    virtual unsigned getNumContainedPasses() const {
      return (unsigned)PassVector.size();
    }
  
    virtual PassManagerType getPassManagerType() const { 
      assert ( 0 && "Invalid use of getPassManagerType");
      return PMT_Unknown; 
    }
  
    std::map<AnalysisID, Pass*> *getAvailableAnalysis() {
      return &AvailableAnalysis;
    }
  
    // Collect AvailableAnalysis from all the active Pass Managers.
    void populateInheritedAnalysis(PMStack &PMS) {
      unsigned Index = 0;
      for (PMStack::iterator I = PMS.begin(), E = PMS.end();
           I != E; ++I)
        InheritedAnalysis[Index++] = (*I)->getAvailableAnalysis();
    }
  
  protected:
  
    // Top level manager.
    PMTopLevelManager *TPM;
  
    // Collection of pass that are managed by this manager
    SmallVector<Pass *, 16> PassVector;
  
    // Collection of Analysis provided by Parent pass manager and
    // used by current pass manager. At at time there can not be more
    // then PMT_Last active pass mangers.
    std::map<AnalysisID, Pass *> *InheritedAnalysis[PMT_Last];
  
    
    /// isPassDebuggingExecutionsOrMore - Return true if -debug-pass=Executions
    /// or higher is specified.
    bool isPassDebuggingExecutionsOrMore() const;
    
  private:
    void dumpAnalysisUsage(StringRef Msg, const Pass *P,
                           const AnalysisUsage::VectorType &Set) const;
  
    // Set of available Analysis. This information is used while scheduling 
    // pass. If a pass requires an analysis which is not available then 
    // the required analysis pass is scheduled to run before the pass itself is
    // scheduled to run.
    std::map<AnalysisID, Pass*> AvailableAnalysis;
  
    // Collection of higher level analysis used by the pass managed by
    // this manager.
    SmallVector<Pass *, 8> HigherLevelAnalysis;
  
    unsigned Depth;
  };
  
  //===----------------------------------------------------------------------===//
  // FPPassManager
  //
  /// FPPassManager manages BBPassManagers and FunctionPasses.
  /// It batches all function passes and basic block pass managers together and 
  /// sequence them to process one function at a time before processing next 
  /// function.
  class FPPassManager : public ModulePass, public PMDataManager {
  public:
    static char ID;
    explicit FPPassManager(int Depth) 
    : ModulePass(ID), PMDataManager(Depth) { }
    
    /// run - Execute all of the passes scheduled for execution.  Keep track of
    /// whether any of the passes modifies the module, and if so, return true.
    bool runOnFunction(Function &F);
    bool runOnModule(Module &M);
    
    /// cleanup - After running all passes, clean up pass manager cache.
    void cleanup();
  
    /// doInitialization - Run all of the initializers for the function passes.
    ///
    bool doInitialization(Module &M);
    
    /// doFinalization - Run all of the finalizers for the function passes.
    ///
    bool doFinalization(Module &M);
  
    virtual PMDataManager *getAsPMDataManager() { return this; }
    virtual Pass *getAsPass() { return this; }
  
    /// Pass Manager itself does not invalidate any analysis info.
    void getAnalysisUsage(AnalysisUsage &Info) const {
      Info.setPreservesAll();
    }
  
    // Print passes managed by this manager
    void dumpPassStructure(unsigned Offset);
  
    virtual const char *getPassName() const {
      return "Function Pass Manager";
    }
  
    FunctionPass *getContainedPass(unsigned N) {
      assert ( N < PassVector.size() && "Pass number out of range!");
      FunctionPass *FP = static_cast<FunctionPass *>(PassVector[N]);
      return FP;
    }
  
    virtual PassManagerType getPassManagerType() const { 
      return PMT_FunctionPassManager; 
    }
  };
  
  Timer *getPassTimer(Pass *);
  
  }
  
  #endif
  