319 lines
		
	
	
		
			9.4 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			319 lines
		
	
	
		
			9.4 KiB
		
	
	
	
		
			C++
		
	
	
	
//= GRState*cpp - Path-Sens. "State" for tracking valuues -----*- C++ -*--=//
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//
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//                     The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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//  This file defines SymbolRef, ExprBindKey, and GRState*
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Analysis/PathSensitive/GRStateTrait.h"
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#include "clang/Analysis/PathSensitive/GRState.h"
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#include "clang/Analysis/PathSensitive/GRTransferFuncs.h"
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#include "llvm/ADT/SmallSet.h"
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#include "llvm/Support/raw_ostream.h"
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using namespace clang;
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// Give the vtable for ConstraintManager somewhere to live.
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ConstraintManager::~ConstraintManager() {}
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GRStateManager::~GRStateManager() {
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  for (std::vector<GRState::Printer*>::iterator I=Printers.begin(),
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        E=Printers.end(); I!=E; ++I)
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    delete *I;
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  for (GDMContextsTy::iterator I=GDMContexts.begin(), E=GDMContexts.end();
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       I!=E; ++I)
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    I->second.second(I->second.first);
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}
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const GRState*
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GRStateManager::RemoveDeadBindings(const GRState* state, Stmt* Loc,
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                                   SymbolReaper& SymReaper) {
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  // This code essentially performs a "mark-and-sweep" of the VariableBindings.
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  // The roots are any Block-level exprs and Decls that our liveness algorithm
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  // tells us are live.  We then see what Decls they may reference, and keep
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  // those around.  This code more than likely can be made faster, and the
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  // frequency of which this method is called should be experimented with
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  // for optimum performance.
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  llvm::SmallVector<const MemRegion*, 10> RegionRoots;
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  GRState NewState = *state;
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  NewState.Env = EnvMgr.RemoveDeadBindings(NewState.Env, Loc, SymReaper, *this,
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                                           state, RegionRoots);
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  // Clean up the store.
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  NewState.St = StoreMgr->RemoveDeadBindings(&NewState, Loc, SymReaper,
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                                             RegionRoots);
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  return ConstraintMgr->RemoveDeadBindings(getPersistentState(NewState),
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                                           SymReaper);
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}
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const GRState* GRStateManager::Unbind(const GRState* St, Loc LV) {
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  Store OldStore = St->getStore();
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  Store NewStore = StoreMgr->Remove(OldStore, LV);
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  if (NewStore == OldStore)
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    return St;
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  GRState NewSt = *St;
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  NewSt.St = NewStore;
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  return getPersistentState(NewSt);    
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}
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const GRState* GRStateManager::getInitialState() {
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  GRState StateImpl(EnvMgr.getInitialEnvironment(), 
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                    StoreMgr->getInitialStore(),
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                    GDMFactory.GetEmptyMap());
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  return getPersistentState(StateImpl);
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}
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const GRState* GRStateManager::getPersistentState(GRState& State) {
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  llvm::FoldingSetNodeID ID;
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  State.Profile(ID);  
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  void* InsertPos;
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  if (GRState* I = StateSet.FindNodeOrInsertPos(ID, InsertPos))
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    return I;
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  GRState* I = (GRState*) Alloc.Allocate<GRState>();
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  new (I) GRState(State);  
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  StateSet.InsertNode(I, InsertPos);
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  return I;
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}
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const GRState* GRStateManager::MakeStateWithStore(const GRState* St, 
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                                                  Store store) {
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  GRState NewSt = *St;
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  NewSt.St = store;
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  return getPersistentState(NewSt);
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}
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//===----------------------------------------------------------------------===//
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//  State pretty-printing.
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//===----------------------------------------------------------------------===//
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void GRState::print(std::ostream& Out, StoreManager& StoreMgr,
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                    ConstraintManager& ConstraintMgr,
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                    Printer** Beg, Printer** End,
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                    const char* nl, const char* sep) const {
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  // Print the store.
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  StoreMgr.print(getStore(), Out, nl, sep);
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  // Print Subexpression bindings.
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  bool isFirst = true;
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  for (seb_iterator I = seb_begin(), E = seb_end(); I != E; ++I) {        
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    if (isFirst) {
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      Out << nl << nl << "Sub-Expressions:" << nl;
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      isFirst = false;
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    }
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    else { Out << nl; }
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    Out << " (" << (void*) I.getKey() << ") ";
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    llvm::raw_os_ostream OutS(Out);
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    I.getKey()->printPretty(OutS);
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    OutS.flush();
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    Out << " : ";
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    I.getData().print(Out);
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  }
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  // Print block-expression bindings.
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  isFirst = true;
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  for (beb_iterator I = beb_begin(), E = beb_end(); I != E; ++I) {      
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    if (isFirst) {
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      Out << nl << nl << "Block-level Expressions:" << nl;
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      isFirst = false;
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    }
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    else { Out << nl; }
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    Out << " (" << (void*) I.getKey() << ") ";
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    llvm::raw_os_ostream OutS(Out);
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    I.getKey()->printPretty(OutS);
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    OutS.flush();
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    Out << " : ";
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    I.getData().print(Out);
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  }
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  ConstraintMgr.print(this, Out, nl, sep);
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  // Print checker-specific data. 
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  for ( ; Beg != End ; ++Beg) (*Beg)->Print(Out, this, nl, sep);
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}
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void GRStateRef::printDOT(std::ostream& Out) const {
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  print(Out, "\\l", "\\|");
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}
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void GRStateRef::printStdErr() const {
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  print(*llvm::cerr);
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}  
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void GRStateRef::print(std::ostream& Out, const char* nl, const char* sep)const{
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  GRState::Printer **beg = Mgr->Printers.empty() ? 0 : &Mgr->Printers[0];
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  GRState::Printer **end = !beg ? 0 : beg + Mgr->Printers.size();  
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  St->print(Out, *Mgr->StoreMgr, *Mgr->ConstraintMgr, beg, end, nl, sep);
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}
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//===----------------------------------------------------------------------===//
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// Generic Data Map.
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//===----------------------------------------------------------------------===//
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void* const* GRState::FindGDM(void* K) const {
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  return GDM.lookup(K);
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}
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void*
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GRStateManager::FindGDMContext(void* K,
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                               void* (*CreateContext)(llvm::BumpPtrAllocator&),
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                               void (*DeleteContext)(void*)) {
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  std::pair<void*, void (*)(void*)>& p = GDMContexts[K];
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  if (!p.first) {
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    p.first = CreateContext(Alloc);
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    p.second = DeleteContext;
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  }
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  return p.first;
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}
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const GRState* GRStateManager::addGDM(const GRState* St, void* Key, void* Data){
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  GRState::GenericDataMap M1 = St->getGDM();
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  GRState::GenericDataMap M2 = GDMFactory.Add(M1, Key, Data);
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  if (M1 == M2)
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    return St;
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  GRState NewSt = *St;
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  NewSt.GDM = M2;
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  return getPersistentState(NewSt);
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}
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//===----------------------------------------------------------------------===//
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// Utility.
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//===----------------------------------------------------------------------===//
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namespace {
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class VISIBILITY_HIDDEN ScanReachableSymbols : public SubRegionMap::Visitor  {
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  typedef llvm::DenseSet<const MemRegion*> VisitedRegionsTy;
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  VisitedRegionsTy visited;
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  GRStateRef state;
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  SymbolVisitor &visitor;
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  llvm::OwningPtr<SubRegionMap> SRM;
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public:
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  ScanReachableSymbols(GRStateManager* sm, const GRState *st, SymbolVisitor& v)
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    : state(st, *sm), visitor(v) {}
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  bool scan(nonloc::CompoundVal val);
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  bool scan(SVal val);
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  bool scan(const MemRegion *R);
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  // From SubRegionMap::Visitor.
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  bool Visit(const MemRegion* Parent, const MemRegion* SubRegion) {
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    return scan(SubRegion);
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  }
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};
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}
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bool ScanReachableSymbols::scan(nonloc::CompoundVal val) {
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  for (nonloc::CompoundVal::iterator I=val.begin(), E=val.end(); I!=E; ++I)
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    if (!scan(*I))
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      return false;
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  return true;
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}
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bool ScanReachableSymbols::scan(SVal val) {
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  if (loc::MemRegionVal *X = dyn_cast<loc::MemRegionVal>(&val))
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    return scan(X->getRegion());
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  if (SymbolRef Sym = val.getAsSymbol())
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    return visitor.VisitSymbol(Sym);
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  if (nonloc::CompoundVal *X = dyn_cast<nonloc::CompoundVal>(&val))
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    return scan(*X);
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  return true;
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}
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bool ScanReachableSymbols::scan(const MemRegion *R) {
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  if (isa<MemSpaceRegion>(R) || visited.count(R))
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    return true;
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  visited.insert(R);
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  // If this is a symbolic region, visit the symbol for the region.
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  if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R))
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    if (!visitor.VisitSymbol(SR->getSymbol()))
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      return false;
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  // If this is a subregion, also visit the parent regions.
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  if (const SubRegion *SR = dyn_cast<SubRegion>(R))
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    if (!scan(SR->getSuperRegion()))
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      return false;
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  // Now look at the binding to this region (if any).
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  if (!scan(state.GetSValAsScalarOrLoc(R)))
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    return false;
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  // Now look at the subregions.
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  if (!SRM.get())
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   SRM.reset(state.getManager().getStoreManager().getSubRegionMap(state));
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  return SRM->iterSubRegions(R, *this);
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}
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bool GRStateManager::scanReachableSymbols(SVal val, const GRState* state,
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                                          SymbolVisitor& visitor) {
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  ScanReachableSymbols S(this, state, visitor);
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  return S.scan(val);
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}
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//===----------------------------------------------------------------------===//
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// Queries.
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//===----------------------------------------------------------------------===//
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bool GRStateManager::isEqual(const GRState* state, Expr* Ex,
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                             const llvm::APSInt& Y) {
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  SVal V = GetSVal(state, Ex);
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  if (loc::ConcreteInt* X = dyn_cast<loc::ConcreteInt>(&V))
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    return X->getValue() == Y;
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  if (nonloc::ConcreteInt* X = dyn_cast<nonloc::ConcreteInt>(&V))
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    return X->getValue() == Y;
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  if (SymbolRef Sym = V.getAsSymbol())
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    return ConstraintMgr->isEqual(state, Sym, Y);
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  return false;
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}
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bool GRStateManager::isEqual(const GRState* state, Expr* Ex, uint64_t x) {
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  return isEqual(state, Ex, getBasicVals().getValue(x, Ex->getType()));
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}
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//===----------------------------------------------------------------------===//
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// Persistent values for indexing into the Generic Data Map.
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int GRState::NullDerefTag::TagInt = 0;
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