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 (CallSite == RHS.CallSite) ? (BlockID < RHS.BlockID)
38                                       : (CallSite < RHS.CallSite);
39   }
40 
41   void Profile(llvm::FoldingSetNodeID &ID) const {
42     ID.AddPointer(CallSite);
43     ID.AddInteger(BlockID);
44   }
45 };
46 
47 }
48 
49 typedef llvm::ImmutableMap<CountKey, unsigned> CountMap;
50 
51 static inline CountMap GetMap(void *D) {
52   return CountMap(static_cast<CountMap::TreeTy*>(D));
53 }
54 
55 static inline CountMap::Factory& GetFactory(void *F) {
56   return *static_cast<CountMap::Factory*>(F);
57 }
58 
59 unsigned BlockCounter::getNumVisited(const StackFrameContext *CallSite,
60                                        unsigned BlockID) const {
61   CountMap M = GetMap(Data);
62   CountMap::data_type* T = M.lookup(CountKey(CallSite, BlockID));
63   return T ? *T : 0;
64 }
65 
66 BlockCounter::Factory::Factory(llvm::BumpPtrAllocator& Alloc) {
67   F = new CountMap::Factory(Alloc);
68 }
69 
70 BlockCounter::Factory::~Factory() {
71   delete static_cast<CountMap::Factory*>(F);
72 }
73 
74 BlockCounter
75 BlockCounter::Factory::IncrementCount(BlockCounter BC,
76                                         const StackFrameContext *CallSite,
77                                         unsigned BlockID) {
78   return BlockCounter(GetFactory(F).add(GetMap(BC.Data),
79                                           CountKey(CallSite, BlockID),
80                              BC.getNumVisited(CallSite, BlockID)+1).getRoot());
81 }
82 
83 BlockCounter
84 BlockCounter::Factory::GetEmptyCounter() {
85   return BlockCounter(GetFactory(F).getEmptyMap().getRoot());
86 }
87