clang/lib/StaticAnalyzer/Core/BlockCounter.cpp

   1 //==- BlockCounter.h - ADT for counting block visits -------------*- C++ -*-//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file defines BlockCounter, an abstract data type used to count
  10 //  the number of times a given block has been visited along a path
  11 //  analyzed by CoreEngine.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "clang/StaticAnalyzer/Core/PathSensitive/BlockCounter.h"
  16 #include "llvm/ADT/ImmutableMap.h"
  17
  18 using namespace clang;
  19 using namespace ento;
  20
  21 namespace {
  22
  23 class CountKey {
  24   const StackFrameContext *CallSite;
  25   unsigned BlockID;
  26
  27 public:
  28   CountKey(const StackFrameContext *CS, unsigned ID)
  29     : CallSite(CS), BlockID(ID) {}
  30
  31   bool operator==(const CountKey &RHS) const {
  32     return (CallSite == RHS.CallSite) && (BlockID == RHS.BlockID);
  33   }
  34
  35   bool operator<(const CountKey &RHS) const {
  36     return std::tie(CallSite, BlockID) < std::tie(RHS.CallSite, RHS.BlockID);
  37   }
  38
  39   void Profile(llvm::FoldingSetNodeID &ID) const {
  40     ID.AddPointer(CallSite);
  41     ID.AddInteger(BlockID);
  42   }
  43 };
  44
  45 }
  46
  47 typedef llvm::ImmutableMap<CountKey, unsigned> CountMap;
  48
  49 static inline CountMap GetMap(void *D) {
  50   return CountMap(static_cast<CountMap::TreeTy*>(D));
  51 }
  52
  53 static inline CountMap::Factory& GetFactory(void *F) {
  54   return *static_cast<CountMap::Factory*>(F);
  55 }
  56
  57 unsigned BlockCounter::getNumVisited(const StackFrameContext *CallSite,
  58                                        unsigned BlockID) const {
  59   CountMap M = GetMap(Data);
  60   CountMap::data_type* T = M.lookup(CountKey(CallSite, BlockID));
  61   return T ? *T : 0;
  62 }
  63
  64 BlockCounter::Factory::Factory(llvm::BumpPtrAllocator& Alloc) {
  65   F = new CountMap::Factory(Alloc);
  66 }
  67
  68 BlockCounter::Factory::~Factory() {
  69   delete static_cast<CountMap::Factory*>(F);
  70 }
  71
  72 BlockCounter
  73 BlockCounter::Factory::IncrementCount(BlockCounter BC,
  74                                         const StackFrameContext *CallSite,
  75                                         unsigned BlockID) {
  76   return BlockCounter(GetFactory(F).add(GetMap(BC.Data),
  77                                           CountKey(CallSite, BlockID),
  78                              BC.getNumVisited(CallSite, BlockID)+1).getRoot());
  79 }
  80
  81 BlockCounter
  82 BlockCounter::Factory::GetEmptyCounter() {
  83   return BlockCounter(GetFactory(F).getEmptyMap().getRoot());
  84 }