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      1 //==- BlockCounter.h - ADT for counting block visits -------------*- C++ -*-//
      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 defines BlockCounter, an abstract data type used to count
     11 //  the number of times a given block has been visited along a path
     12 //  analyzed by CoreEngine.
     13 //
     14 //===----------------------------------------------------------------------===//
     15 
     16 #include "clang/StaticAnalyzer/Core/PathSensitive/BlockCounter.h"
     17 #include "llvm/ADT/ImmutableMap.h"
     18 
     19 using namespace clang;
     20 using namespace ento;
     21 
     22 namespace {
     23 
     24 class CountKey {
     25   const StackFrameContext *CallSite;
     26   unsigned BlockID;
     27 
     28 public:
     29   CountKey(const StackFrameContext *CS, unsigned ID)
     30     : CallSite(CS), BlockID(ID) {}
     31 
     32   bool operator==(const CountKey &RHS) const {
     33     return (CallSite == RHS.CallSite) && (BlockID == RHS.BlockID);
     34   }
     35 
     36   bool operator<(const CountKey &RHS) const {
     37     return std::tie(CallSite, BlockID) < std::tie(RHS.CallSite, RHS.BlockID);
     38   }
     39 
     40   void Profile(llvm::FoldingSetNodeID &ID) const {
     41     ID.AddPointer(CallSite);
     42     ID.AddInteger(BlockID);
     43   }
     44 };
     45 
     46 }
     47 
     48 typedef llvm::ImmutableMap<CountKey, unsigned> CountMap;
     49 
     50 static inline CountMap GetMap(void *D) {
     51   return CountMap(static_cast<CountMap::TreeTy*>(D));
     52 }
     53 
     54 static inline CountMap::Factory& GetFactory(void *F) {
     55   return *static_cast<CountMap::Factory*>(F);
     56 }
     57 
     58 unsigned BlockCounter::getNumVisited(const StackFrameContext *CallSite,
     59                                        unsigned BlockID) const {
     60   CountMap M = GetMap(Data);
     61   CountMap::data_type* T = M.lookup(CountKey(CallSite, BlockID));
     62   return T ? *T : 0;
     63 }
     64 
     65 BlockCounter::Factory::Factory(llvm::BumpPtrAllocator& Alloc) {
     66   F = new CountMap::Factory(Alloc);
     67 }
     68 
     69 BlockCounter::Factory::~Factory() {
     70   delete static_cast<CountMap::Factory*>(F);
     71 }
     72 
     73 BlockCounter
     74 BlockCounter::Factory::IncrementCount(BlockCounter BC,
     75                                         const StackFrameContext *CallSite,
     76                                         unsigned BlockID) {
     77   return BlockCounter(GetFactory(F).add(GetMap(BC.Data),
     78                                           CountKey(CallSite, BlockID),
     79                              BC.getNumVisited(CallSite, BlockID)+1).getRoot());
     80 }
     81 
     82 BlockCounter
     83 BlockCounter::Factory::GetEmptyCounter() {
     84   return BlockCounter(GetFactory(F).getEmptyMap().getRoot());
     85 }
     86