//==- ProgramPoint.h - Program Points for Path-Sensitive Analysis --*- C++ -*-//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the interface ProgramPoint, which identifies a
//  distinct location in a function.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_ANALYSIS_PROGRAM_POINT
#define LLVM_CLANG_ANALYSIS_PROGRAM_POINT

#include "clang/Analysis/CFG.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/Support/Casting.h"
#include <cassert>
#include <utility>

namespace clang {
    
class ProgramPoint {
public:
  enum Kind { BlockEdgeKind,
              BlockEntranceKind,
              BlockExitKind,
              PreStmtKind,
              // Keep the following together and in this order.
              PostStmtKind,
              PostLocationChecksSucceedKind,
              PostOutOfBoundsCheckFailedKind,
              PostNullCheckFailedKind,
              PostUndefLocationCheckFailedKind,
              PostLoadKind,
              PostStoreKind,
              PostPurgeDeadSymbolsKind,
              PostStmtCustomKind,
              PostLValueKind,
              MinPostStmtKind = PostStmtKind,
              MaxPostStmtKind = PostLValueKind };

private:
  std::pair<const void *, const void *> Data;
  Kind K;
  const void *Tag;
  
protected:
  ProgramPoint(const void* P, Kind k, const void *tag = 0)
    : Data(P, NULL), K(k), Tag(tag) {}
    
  ProgramPoint(const void* P1, const void* P2, Kind k, const void *tag = 0)
    : Data(P1, P2), K(k), Tag(tag) {}

protected:
  const void* getData1() const { return Data.first; }
  const void* getData2() const { return Data.second; }
  const void *getTag() const { return Tag; }
    
public:    
  Kind getKind() const { return K; }

  // For use with DenseMap.  This hash is probably slow.
  unsigned getHashValue() const {
    llvm::FoldingSetNodeID ID;
    Profile(ID);
    return ID.ComputeHash();
  }
  
  static bool classof(const ProgramPoint*) { return true; }

  bool operator==(const ProgramPoint & RHS) const {
    return K == RHS.K && Data == RHS.Data && Tag == RHS.Tag;
  }

  bool operator!=(const ProgramPoint& RHS) const {
    return K != RHS.K || Data != RHS.Data || Tag != RHS.Tag;
  }
    
  void Profile(llvm::FoldingSetNodeID& ID) const {
    ID.AddInteger((unsigned) K);
    ID.AddPointer(Data.first);
    ID.AddPointer(Data.second);
    ID.AddPointer(Tag);
  }
};
               
class BlockEntrance : public ProgramPoint {
public:
  BlockEntrance(const CFGBlock* B, const void *tag = 0)
    : ProgramPoint(B, BlockEntranceKind, tag) {}
    
  CFGBlock* getBlock() const {
    return const_cast<CFGBlock*>(reinterpret_cast<const CFGBlock*>(getData1()));
  }
  
  Stmt* getFirstStmt() const {
    const CFGBlock* B = getBlock();
    return B->empty() ? NULL : B->front();
  }

  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == BlockEntranceKind;
  }
};

class BlockExit : public ProgramPoint {
public:
  BlockExit(const CFGBlock* B) : ProgramPoint(B, BlockExitKind) {}
  
  CFGBlock* getBlock() const {
    return const_cast<CFGBlock*>(reinterpret_cast<const CFGBlock*>(getData1()));
  }

  Stmt* getLastStmt() const {
    const CFGBlock* B = getBlock();
    return B->empty() ? NULL : B->back();
  }
  
  Stmt* getTerminator() const {
    return getBlock()->getTerminator();
  }
    
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == BlockExitKind;
  }
};
  
class StmtPoint : public ProgramPoint {
public:
  StmtPoint(const Stmt *S, const void *p2, Kind k, const void *tag)
  : ProgramPoint(S, p2, k, tag) {}
  
  const Stmt *getStmt() const { return (const Stmt*) getData1(); }
  
  template <typename T>
  const T* getStmtAs() const { return llvm::dyn_cast<T>(getStmt()); }
  
  static bool classof(const ProgramPoint* Location) {
    unsigned k = Location->getKind();
    return k >= PreStmtKind && k <= MaxPostStmtKind;
  }
};  

  
class PreStmt : public StmtPoint {
public:
  PreStmt(const Stmt *S, const void *tag, const Stmt *SubStmt = 0)
    : StmtPoint(S, SubStmt, PreStmtKind, tag) {}

  const Stmt *getSubStmt() const { return (const Stmt*) getData2(); }  

  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PreStmtKind;
  }
};

class PostStmt : public StmtPoint {
protected:
  PostStmt(const Stmt* S, Kind k, const void *tag = 0)
    : StmtPoint(S, NULL, k, tag) {}

  PostStmt(const Stmt* S, const void* data, Kind k, const void *tag =0)
    : StmtPoint(S, data, k, tag) {}
  
public:
  explicit PostStmt(const Stmt* S, const void *tag = 0)
    : StmtPoint(S, NULL, PostStmtKind, tag) {}

  static bool classof(const ProgramPoint* Location) {
    unsigned k = Location->getKind();
    return k >= MinPostStmtKind && k <= MaxPostStmtKind;
  }
};

class PostLocationChecksSucceed : public PostStmt {
public:
  PostLocationChecksSucceed(const Stmt* S, const void *tag = 0)
    : PostStmt(S, PostLocationChecksSucceedKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostLocationChecksSucceedKind;
  }
};
  
class PostStmtCustom : public PostStmt {
public:
  PostStmtCustom(const Stmt* S,
                 const std::pair<const void*, const void*>* TaggedData)
    : PostStmt(S, TaggedData, PostStmtCustomKind) {}

  const std::pair<const void*, const void*>& getTaggedPair() const {
    return
      *reinterpret_cast<const std::pair<const void*, const void*>*>(getData2());
  }
  
  const void* getTag() const { return getTaggedPair().first; }
  
  const void* getTaggedData() const { return getTaggedPair().second; }
    
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostStmtCustomKind;
  }
};
  
class PostOutOfBoundsCheckFailed : public PostStmt {
public:
  PostOutOfBoundsCheckFailed(const Stmt* S, const void *tag = 0)
  : PostStmt(S, PostOutOfBoundsCheckFailedKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostOutOfBoundsCheckFailedKind;
  }
};

class PostUndefLocationCheckFailed : public PostStmt {
public:
  PostUndefLocationCheckFailed(const Stmt* S, const void *tag = 0)
  : PostStmt(S, PostUndefLocationCheckFailedKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostUndefLocationCheckFailedKind;
  }
};
  
class PostNullCheckFailed : public PostStmt {
public:
  PostNullCheckFailed(const Stmt* S, const void *tag = 0)
  : PostStmt(S, PostNullCheckFailedKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostNullCheckFailedKind;
  }
};
  
class PostLoad : public PostStmt {
public:
  PostLoad(const Stmt* S, const void *tag = 0)
    : PostStmt(S, PostLoadKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostLoadKind;
  }
};
  
class PostStore : public PostStmt {
public:
  PostStore(const Stmt* S, const void *tag = 0)
    : PostStmt(S, PostStoreKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostStoreKind;
  }
};

class PostLValue : public PostStmt {
public:
  PostLValue(const Stmt* S, const void *tag = 0)
  : PostStmt(S, PostLValueKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostLValueKind;
  }
};  
  
class PostPurgeDeadSymbols : public PostStmt {
public:
  PostPurgeDeadSymbols(const Stmt* S, const void *tag = 0)
    : PostStmt(S, PostPurgeDeadSymbolsKind, tag) {}
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == PostPurgeDeadSymbolsKind;
  }
};
  
class BlockEdge : public ProgramPoint {
public:
  BlockEdge(const CFGBlock* B1, const CFGBlock* B2)
    : ProgramPoint(B1, B2, BlockEdgeKind) {}
    
  CFGBlock* getSrc() const {
    return const_cast<CFGBlock*>(static_cast<const CFGBlock*>(getData1()));
  }
    
  CFGBlock* getDst() const {
    return const_cast<CFGBlock*>(static_cast<const CFGBlock*>(getData2()));
  }
  
  static bool classof(const ProgramPoint* Location) {
    return Location->getKind() == BlockEdgeKind;
  }
};

  
} // end namespace clang


namespace llvm { // Traits specialization for DenseMap 
  
template <> struct DenseMapInfo<clang::ProgramPoint> {

static inline clang::ProgramPoint getEmptyKey() {
  uintptr_t x =
   reinterpret_cast<uintptr_t>(DenseMapInfo<void*>::getEmptyKey()) & ~0x7;    
  return clang::BlockEntrance(reinterpret_cast<clang::CFGBlock*>(x));
}

static inline clang::ProgramPoint getTombstoneKey() {
  uintptr_t x =
   reinterpret_cast<uintptr_t>(DenseMapInfo<void*>::getTombstoneKey()) & ~0x7;    
  return clang::BlockEntrance(reinterpret_cast<clang::CFGBlock*>(x));
}

static unsigned getHashValue(const clang::ProgramPoint& Loc) {
  return Loc.getHashValue();
}

static bool isEqual(const clang::ProgramPoint& L,
                    const clang::ProgramPoint& R) {
  return L == R;
}

static bool isPod() {
  return true;
}
};
} // end namespace llvm

#endif