Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 1096 deletions

diff --git a/gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp b/gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
deleted file mode 100644
index 00a912f27a8..00000000000
--- a/gnu/llvm/tools/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
+++ /dev/null
@@ -1,1096 +0,0 @@
-//==- CheckObjCDealloc.cpp - Check ObjC -dealloc implementation --*- C++ -*-==//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-//  This checker analyzes Objective-C -dealloc methods and their callees
-//  to warn about improper releasing of instance variables that back synthesized
-// properties. It warns about missing releases in the following cases:
-//  - When a class has a synthesized instance variable for a 'retain' or 'copy'
-//    property and lacks a -dealloc method in its implementation.
-//  - When a class has a synthesized instance variable for a 'retain'/'copy'
-//   property but the ivar is not released in -dealloc by either -release
-//   or by nilling out the property.
-//
-//  It warns about extra releases in -dealloc (but not in callees) when a
-//  synthesized instance variable is released in the following cases:
-//  - When the property is 'assign' and is not 'readonly'.
-//  - When the property is 'weak'.
-//
-//  This checker only warns for instance variables synthesized to back
-//  properties. Handling the more general case would require inferring whether
-//  an instance variable is stored retained or not. For synthesized properties,
-//  this is specified in the property declaration itself.
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
-#include "clang/AST/Attr.h"
-#include "clang/AST/DeclObjC.h"
-#include "clang/AST/Expr.h"
-#include "clang/AST/ExprObjC.h"
-#include "clang/Basic/LangOptions.h"
-#include "clang/Basic/TargetInfo.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
-#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
-#include "clang/StaticAnalyzer/Core/Checker.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
-#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace clang;
-using namespace ento;
-
-/// Indicates whether an instance variable is required to be released in
-/// -dealloc.
-enum class ReleaseRequirement {
-  /// The instance variable must be released, either by calling
-  /// -release on it directly or by nilling it out with a property setter.
-  MustRelease,
-
-  /// The instance variable must not be directly released with -release.
-  MustNotReleaseDirectly,
-
-  /// The requirement for the instance variable could not be determined.
-  Unknown
-};
-
-/// Returns true if the property implementation is synthesized and the
-/// type of the property is retainable.
-static bool isSynthesizedRetainableProperty(const ObjCPropertyImplDecl *I,
-                                            const ObjCIvarDecl **ID,
-                                            const ObjCPropertyDecl **PD) {
-
-  if (I->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize)
-    return false;
-
-  (*ID) = I->getPropertyIvarDecl();
-  if (!(*ID))
-    return false;
-
-  QualType T = (*ID)->getType();
-  if (!T->isObjCRetainableType())
-    return false;
-
-  (*PD) = I->getPropertyDecl();
-  // Shouldn't be able to synthesize a property that doesn't exist.
-  assert(*PD);
-
-  return true;
-}
-
-namespace {
-
-class ObjCDeallocChecker
-    : public Checker<check::ASTDecl<ObjCImplementationDecl>,
-                     check::PreObjCMessage, check::PostObjCMessage,
-                     check::PreCall,
-                     check::BeginFunction, check::EndFunction,
-                     eval::Assume,
-                     check::PointerEscape,
-                     check::PreStmt<ReturnStmt>> {
-
-  mutable IdentifierInfo *NSObjectII, *SenTestCaseII, *XCTestCaseII,
-      *Block_releaseII, *CIFilterII;
-
-  mutable Selector DeallocSel, ReleaseSel;
-
-  std::unique_ptr<BugType> MissingReleaseBugType;
-  std::unique_ptr<BugType> ExtraReleaseBugType;
-  std::unique_ptr<BugType> MistakenDeallocBugType;
-
-public:
-  ObjCDeallocChecker();
-
-  void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager& Mgr,
-                    BugReporter &BR) const;
-  void checkBeginFunction(CheckerContext &Ctx) const;
-  void checkPreObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
-  void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
-  void checkPostObjCMessage(const ObjCMethodCall &M, CheckerContext &C) const;
-
-  ProgramStateRef evalAssume(ProgramStateRef State, SVal Cond,
-                             bool Assumption) const;
-
-  ProgramStateRef checkPointerEscape(ProgramStateRef State,
-                                     const InvalidatedSymbols &Escaped,
-                                     const CallEvent *Call,
-                                     PointerEscapeKind Kind) const;
-  void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const;
-  void checkEndFunction(const ReturnStmt *RS, CheckerContext &Ctx) const;
-
-private:
-  void diagnoseMissingReleases(CheckerContext &C) const;
-
-  bool diagnoseExtraRelease(SymbolRef ReleasedValue, const ObjCMethodCall &M,
-                            CheckerContext &C) const;
-
-  bool diagnoseMistakenDealloc(SymbolRef DeallocedValue,
-                               const ObjCMethodCall &M,
-                               CheckerContext &C) const;
-
-  SymbolRef getValueReleasedByNillingOut(const ObjCMethodCall &M,
-                                         CheckerContext &C) const;
-
-  const ObjCIvarRegion *getIvarRegionForIvarSymbol(SymbolRef IvarSym) const;
-  SymbolRef getInstanceSymbolFromIvarSymbol(SymbolRef IvarSym) const;
-
-  const ObjCPropertyImplDecl*
-  findPropertyOnDeallocatingInstance(SymbolRef IvarSym,
-                                     CheckerContext &C) const;
-
-  ReleaseRequirement
-  getDeallocReleaseRequirement(const ObjCPropertyImplDecl *PropImpl) const;
-
-  bool isInInstanceDealloc(const CheckerContext &C, SVal &SelfValOut) const;
-  bool isInInstanceDealloc(const CheckerContext &C, const LocationContext *LCtx,
-                           SVal &SelfValOut) const;
-  bool instanceDeallocIsOnStack(const CheckerContext &C,
-                                SVal &InstanceValOut) const;
-
-  bool isSuperDeallocMessage(const ObjCMethodCall &M) const;
-
-  const ObjCImplDecl *getContainingObjCImpl(const LocationContext *LCtx) const;
-
-  const ObjCPropertyDecl *
-  findShadowedPropertyDecl(const ObjCPropertyImplDecl *PropImpl) const;
-
-  void transitionToReleaseValue(CheckerContext &C, SymbolRef Value) const;
-  ProgramStateRef removeValueRequiringRelease(ProgramStateRef State,
-                                              SymbolRef InstanceSym,
-                                              SymbolRef ValueSym) const;
-
-  void initIdentifierInfoAndSelectors(ASTContext &Ctx) const;
-
-  bool classHasSeparateTeardown(const ObjCInterfaceDecl *ID) const;
-
-  bool isReleasedByCIFilterDealloc(const ObjCPropertyImplDecl *PropImpl) const;
-  bool isNibLoadedIvarWithoutRetain(const ObjCPropertyImplDecl *PropImpl) const;
-};
-} // End anonymous namespace.
-
-
-/// Maps from the symbol for a class instance to the set of
-/// symbols remaining that must be released in -dealloc.
-REGISTER_SET_FACTORY_WITH_PROGRAMSTATE(SymbolSet, SymbolRef)
-REGISTER_MAP_WITH_PROGRAMSTATE(UnreleasedIvarMap, SymbolRef, SymbolSet)
-
-
-/// An AST check that diagnose when the class requires a -dealloc method and
-/// is missing one.
-void ObjCDeallocChecker::checkASTDecl(const ObjCImplementationDecl *D,
-                                      AnalysisManager &Mgr,
-                                      BugReporter &BR) const {
-  assert(Mgr.getLangOpts().getGC() != LangOptions::GCOnly);
-  assert(!Mgr.getLangOpts().ObjCAutoRefCount);
-  initIdentifierInfoAndSelectors(Mgr.getASTContext());
-
-  const ObjCInterfaceDecl *ID = D->getClassInterface();
-  // If the class is known to have a lifecycle with a separate teardown method
-  // then it may not require a -dealloc method.
-  if (classHasSeparateTeardown(ID))
-    return;
-
-  // Does the class contain any synthesized properties that are retainable?
-  // If not, skip the check entirely.
-  const ObjCPropertyImplDecl *PropImplRequiringRelease = nullptr;
-  bool HasOthers = false;
-  for (const auto *I : D->property_impls()) {
-    if (getDeallocReleaseRequirement(I) == ReleaseRequirement::MustRelease) {
-      if (!PropImplRequiringRelease)
-        PropImplRequiringRelease = I;
-      else {
-        HasOthers = true;
-        break;
-      }
-    }
-  }
-
-  if (!PropImplRequiringRelease)
-    return;
-
-  const ObjCMethodDecl *MD = nullptr;
-
-  // Scan the instance methods for "dealloc".
-  for (const auto *I : D->instance_methods()) {
-    if (I->getSelector() == DeallocSel) {
-      MD = I;
-      break;
-    }
-  }
-
-  if (!MD) { // No dealloc found.
-    const char* Name = "Missing -dealloc";
-
-    std::string Buf;
-    llvm::raw_string_ostream OS(Buf);
-    OS << "'" << *D << "' lacks a 'dealloc' instance method but "
-       << "must release '" << *PropImplRequiringRelease->getPropertyIvarDecl()
-       << "'";
-
-    if (HasOthers)
-      OS << " and others";
-    PathDiagnosticLocation DLoc =
-        PathDiagnosticLocation::createBegin(D, BR.getSourceManager());
-
-    BR.EmitBasicReport(D, this, Name, categories::CoreFoundationObjectiveC,
-                       OS.str(), DLoc);
-    return;
-  }
-}
-
-/// If this is the beginning of -dealloc, mark the values initially stored in
-/// instance variables that must be released by the end of -dealloc
-/// as unreleased in the state.
-void ObjCDeallocChecker::checkBeginFunction(
-    CheckerContext &C) const {
-  initIdentifierInfoAndSelectors(C.getASTContext());
-
-  // Only do this if the current method is -dealloc.
-  SVal SelfVal;
-  if (!isInInstanceDealloc(C, SelfVal))
-    return;
-
-  SymbolRef SelfSymbol = SelfVal.getAsSymbol();
-
-  const LocationContext *LCtx = C.getLocationContext();
-  ProgramStateRef InitialState = C.getState();
-
-  ProgramStateRef State = InitialState;
-
-  SymbolSet::Factory &F = State->getStateManager().get_context<SymbolSet>();
-
-  // Symbols that must be released by the end of the -dealloc;
-  SymbolSet RequiredReleases = F.getEmptySet();
-
-  // If we're an inlined -dealloc, we should add our symbols to the existing
-  // set from our subclass.
-  if (const SymbolSet *CurrSet = State->get<UnreleasedIvarMap>(SelfSymbol))
-    RequiredReleases = *CurrSet;
-
-  for (auto *PropImpl : getContainingObjCImpl(LCtx)->property_impls()) {
-    ReleaseRequirement Requirement = getDeallocReleaseRequirement(PropImpl);
-    if (Requirement != ReleaseRequirement::MustRelease)
-      continue;
-
-    SVal LVal = State->getLValue(PropImpl->getPropertyIvarDecl(), SelfVal);
-    Optional<Loc> LValLoc = LVal.getAs<Loc>();
-    if (!LValLoc)
-      continue;
-
-    SVal InitialVal = State->getSVal(LValLoc.getValue());
-    SymbolRef Symbol = InitialVal.getAsSymbol();
-    if (!Symbol || !isa<SymbolRegionValue>(Symbol))
-      continue;
-
-    // Mark the value as requiring a release.
-    RequiredReleases = F.add(RequiredReleases, Symbol);
-  }
-
-  if (!RequiredReleases.isEmpty()) {
-    State = State->set<UnreleasedIvarMap>(SelfSymbol, RequiredReleases);
-  }
-
-  if (State != InitialState) {
-    C.addTransition(State);
-  }
-}
-
-/// Given a symbol for an ivar, return the ivar region it was loaded from.
-/// Returns nullptr if the instance symbol cannot be found.
-const ObjCIvarRegion *
-ObjCDeallocChecker::getIvarRegionForIvarSymbol(SymbolRef IvarSym) const {
-  return dyn_cast_or_null<ObjCIvarRegion>(IvarSym->getOriginRegion());
-}
-
-/// Given a symbol for an ivar, return a symbol for the instance containing
-/// the ivar. Returns nullptr if the instance symbol cannot be found.
-SymbolRef
-ObjCDeallocChecker::getInstanceSymbolFromIvarSymbol(SymbolRef IvarSym) const {
-
-  const ObjCIvarRegion *IvarRegion = getIvarRegionForIvarSymbol(IvarSym);
-  if (!IvarRegion)
-    return nullptr;
-
-  return IvarRegion->getSymbolicBase()->getSymbol();
-}
-
-/// If we are in -dealloc or -dealloc is on the stack, handle the call if it is
-/// a release or a nilling-out property setter.
-void ObjCDeallocChecker::checkPreObjCMessage(
-    const ObjCMethodCall &M, CheckerContext &C) const {
-  // Only run if -dealloc is on the stack.
-  SVal DeallocedInstance;
-  if (!instanceDeallocIsOnStack(C, DeallocedInstance))
-    return;
-
-  SymbolRef ReleasedValue = nullptr;
-
-  if (M.getSelector() == ReleaseSel) {
-    ReleasedValue = M.getReceiverSVal().getAsSymbol();
-  } else if (M.getSelector() == DeallocSel && !M.isReceiverSelfOrSuper()) {
-    if (diagnoseMistakenDealloc(M.getReceiverSVal().getAsSymbol(), M, C))
-      return;
-  }
-
-  if (ReleasedValue) {
-    // An instance variable symbol was released with -release:
-    //    [_property release];
-    if (diagnoseExtraRelease(ReleasedValue,M, C))
-      return;
-  } else {
-    // An instance variable symbol was released nilling out its property:
-    //    self.property = nil;
-    ReleasedValue = getValueReleasedByNillingOut(M, C);
-  }
-
-  if (!ReleasedValue)
-    return;
-
-  transitionToReleaseValue(C, ReleasedValue);
-}
-
-/// If we are in -dealloc or -dealloc is on the stack, handle the call if it is
-/// call to Block_release().
-void ObjCDeallocChecker::checkPreCall(const CallEvent &Call,
-                                      CheckerContext &C) const {
-  const IdentifierInfo *II = Call.getCalleeIdentifier();
-  if (II != Block_releaseII)
-    return;
-
-  if (Call.getNumArgs() != 1)
-    return;
-
-  SymbolRef ReleasedValue = Call.getArgSVal(0).getAsSymbol();
-  if (!ReleasedValue)
-    return;
-
-  transitionToReleaseValue(C, ReleasedValue);
-}
-/// If the message was a call to '[super dealloc]', diagnose any missing
-/// releases.
-void ObjCDeallocChecker::checkPostObjCMessage(
-    const ObjCMethodCall &M, CheckerContext &C) const {
-  // We perform this check post-message so that if the super -dealloc
-  // calls a helper method and that this class overrides, any ivars released in
-  // the helper method will be recorded before checking.
-  if (isSuperDeallocMessage(M))
-    diagnoseMissingReleases(C);
-}
-
-/// Check for missing releases even when -dealloc does not call
-/// '[super dealloc]'.
-void ObjCDeallocChecker::checkEndFunction(
-    const ReturnStmt *RS, CheckerContext &C) const {
-  diagnoseMissingReleases(C);
-}
-
-/// Check for missing releases on early return.
-void ObjCDeallocChecker::checkPreStmt(
-    const ReturnStmt *RS, CheckerContext &C) const {
-  diagnoseMissingReleases(C);
-}
-
-/// When a symbol is assumed to be nil, remove it from the set of symbols
-/// require to be nil.
-ProgramStateRef ObjCDeallocChecker::evalAssume(ProgramStateRef State, SVal Cond,
-                                               bool Assumption) const {
-  if (State->get<UnreleasedIvarMap>().isEmpty())
-    return State;
-
-  auto *CondBSE = dyn_cast_or_null<BinarySymExpr>(Cond.getAsSymExpr());
-  if (!CondBSE)
-    return State;
-
-  BinaryOperator::Opcode OpCode = CondBSE->getOpcode();
-  if (Assumption) {
-    if (OpCode != BO_EQ)
-      return State;
-  } else {
-    if (OpCode != BO_NE)
-      return State;
-  }
-
-  SymbolRef NullSymbol = nullptr;
-  if (auto *SIE = dyn_cast<SymIntExpr>(CondBSE)) {
-    const llvm::APInt &RHS = SIE->getRHS();
-    if (RHS != 0)
-      return State;
-    NullSymbol = SIE->getLHS();
-  } else if (auto *SIE = dyn_cast<IntSymExpr>(CondBSE)) {
-    const llvm::APInt &LHS = SIE->getLHS();
-    if (LHS != 0)
-      return State;
-    NullSymbol = SIE->getRHS();
-  } else {
-    return State;
-  }
-
-  SymbolRef InstanceSymbol = getInstanceSymbolFromIvarSymbol(NullSymbol);
-  if (!InstanceSymbol)
-    return State;
-
-  State = removeValueRequiringRelease(State, InstanceSymbol, NullSymbol);
-
-  return State;
-}
-
-/// If a symbol escapes conservatively assume unseen code released it.
-ProgramStateRef ObjCDeallocChecker::checkPointerEscape(
-    ProgramStateRef State, const InvalidatedSymbols &Escaped,
-    const CallEvent *Call, PointerEscapeKind Kind) const {
-
-  if (State->get<UnreleasedIvarMap>().isEmpty())
-    return State;
-
-  // Don't treat calls to '[super dealloc]' as escaping for the purposes
-  // of this checker. Because the checker diagnoses missing releases in the
-  // post-message handler for '[super dealloc], escaping here would cause
-  // the checker to never warn.
-  auto *OMC = dyn_cast_or_null<ObjCMethodCall>(Call);
-  if (OMC && isSuperDeallocMessage(*OMC))
-    return State;
-
-  for (const auto &Sym : Escaped) {
-    if (!Call || (Call && !Call->isInSystemHeader())) {
-      // If Sym is a symbol for an object with instance variables that
-      // must be released, remove these obligations when the object escapes
-      // unless via a call to a system function. System functions are
-      // very unlikely to release instance variables on objects passed to them,
-      // and are frequently called on 'self' in -dealloc (e.g., to remove
-      // observers) -- we want to avoid false negatives from escaping on
-      // them.
-      State = State->remove<UnreleasedIvarMap>(Sym);
-    }
-
-
-    SymbolRef InstanceSymbol = getInstanceSymbolFromIvarSymbol(Sym);
-    if (!InstanceSymbol)
-      continue;
-
-    State = removeValueRequiringRelease(State, InstanceSymbol, Sym);
-  }
-
-  return State;
-}
-
-/// Report any unreleased instance variables for the current instance being
-/// dealloced.
-void ObjCDeallocChecker::diagnoseMissingReleases(CheckerContext &C) const {
-  ProgramStateRef State = C.getState();
-
-  SVal SelfVal;
-  if (!isInInstanceDealloc(C, SelfVal))
-    return;
-
-  const MemRegion *SelfRegion = SelfVal.castAs<loc::MemRegionVal>().getRegion();
-  const LocationContext *LCtx = C.getLocationContext();
-
-  ExplodedNode *ErrNode = nullptr;
-
-  SymbolRef SelfSym = SelfVal.getAsSymbol();
-  if (!SelfSym)
-    return;
-
-  const SymbolSet *OldUnreleased = State->get<UnreleasedIvarMap>(SelfSym);
-  if (!OldUnreleased)
-    return;
-
-  SymbolSet NewUnreleased = *OldUnreleased;
-  SymbolSet::Factory &F = State->getStateManager().get_context<SymbolSet>();
-
-  ProgramStateRef InitialState = State;
-
-  for (auto *IvarSymbol : *OldUnreleased) {
-    const TypedValueRegion *TVR =
-        cast<SymbolRegionValue>(IvarSymbol)->getRegion();
-    const ObjCIvarRegion *IvarRegion = cast<ObjCIvarRegion>(TVR);
-
-    // Don't warn if the ivar is not for this instance.
-    if (SelfRegion != IvarRegion->getSuperRegion())
-      continue;
-
-    const ObjCIvarDecl *IvarDecl = IvarRegion->getDecl();
-    // Prevent an inlined call to -dealloc in a super class from warning
-    // about the values the subclass's -dealloc should release.
-    if (IvarDecl->getContainingInterface() !=
-        cast<ObjCMethodDecl>(LCtx->getDecl())->getClassInterface())
-      continue;
-
-    // Prevents diagnosing multiple times for the same instance variable
-    // at, for example, both a return and at the end of the function.
-    NewUnreleased = F.remove(NewUnreleased, IvarSymbol);
-
-    if (State->getStateManager()
-            .getConstraintManager()
-            .isNull(State, IvarSymbol)
-            .isConstrainedTrue()) {
-      continue;
-    }
-
-    // A missing release manifests as a leak, so treat as a non-fatal error.
-    if (!ErrNode)
-      ErrNode = C.generateNonFatalErrorNode();
-    // If we've already reached this node on another path, return without
-    // diagnosing.
-    if (!ErrNode)
-      return;
-
-    std::string Buf;
-    llvm::raw_string_ostream OS(Buf);
-
-    const ObjCInterfaceDecl *Interface = IvarDecl->getContainingInterface();
-    // If the class is known to have a lifecycle with teardown that is
-    // separate from -dealloc, do not warn about missing releases. We
-    // suppress here (rather than not tracking for instance variables in
-    // such classes) because these classes are rare.
-    if (classHasSeparateTeardown(Interface))
-      return;
-
-    ObjCImplDecl *ImplDecl = Interface->getImplementation();
-
-    const ObjCPropertyImplDecl *PropImpl =
-        ImplDecl->FindPropertyImplIvarDecl(IvarDecl->getIdentifier());
-
-    const ObjCPropertyDecl *PropDecl = PropImpl->getPropertyDecl();
-
-    assert(PropDecl->getSetterKind() == ObjCPropertyDecl::Copy ||
-           PropDecl->getSetterKind() == ObjCPropertyDecl::Retain);
-
-    OS << "The '" << *IvarDecl << "' ivar in '" << *ImplDecl
-       << "' was ";
-
-    if (PropDecl->getSetterKind() == ObjCPropertyDecl::Retain)
-      OS << "retained";
-    else
-      OS << "copied";
-
-    OS << " by a synthesized property but not released"
-          " before '[super dealloc]'";
-
-    std::unique_ptr<BugReport> BR(
-        new BugReport(*MissingReleaseBugType, OS.str(), ErrNode));
-
-    C.emitReport(std::move(BR));
-  }
-
-  if (NewUnreleased.isEmpty()) {
-    State = State->remove<UnreleasedIvarMap>(SelfSym);
-  } else {
-    State = State->set<UnreleasedIvarMap>(SelfSym, NewUnreleased);
-  }
-
-  if (ErrNode) {
-    C.addTransition(State, ErrNode);
-  } else if (State != InitialState) {
-    C.addTransition(State);
-  }
-
-  // Make sure that after checking in the top-most frame the list of
-  // tracked ivars is empty. This is intended to detect accidental leaks in
-  // the UnreleasedIvarMap program state.
-  assert(!LCtx->inTopFrame() || State->get<UnreleasedIvarMap>().isEmpty());
-}
-
-/// Given a symbol, determine whether the symbol refers to an ivar on
-/// the top-most deallocating instance. If so, find the property for that
-/// ivar, if one exists. Otherwise return null.
-const ObjCPropertyImplDecl *
-ObjCDeallocChecker::findPropertyOnDeallocatingInstance(
-    SymbolRef IvarSym, CheckerContext &C) const {
-  SVal DeallocedInstance;
-  if (!isInInstanceDealloc(C, DeallocedInstance))
-    return nullptr;
-
-  // Try to get the region from which the ivar value was loaded.
-  auto *IvarRegion = getIvarRegionForIvarSymbol(IvarSym);
-  if (!IvarRegion)
-    return nullptr;
-
-  // Don't try to find the property if the ivar was not loaded from the
-  // given instance.
-  if (DeallocedInstance.castAs<loc::MemRegionVal>().getRegion() !=
-      IvarRegion->getSuperRegion())
-    return nullptr;
-
-  const LocationContext *LCtx = C.getLocationContext();
-  const ObjCIvarDecl *IvarDecl = IvarRegion->getDecl();
-
-  const ObjCImplDecl *Container = getContainingObjCImpl(LCtx);
-  const ObjCPropertyImplDecl *PropImpl =
-      Container->FindPropertyImplIvarDecl(IvarDecl->getIdentifier());
-  return PropImpl;
-}
-
-/// Emits a warning if the current context is -dealloc and ReleasedValue
-/// must not be directly released in a -dealloc. Returns true if a diagnostic
-/// was emitted.
-bool ObjCDeallocChecker::diagnoseExtraRelease(SymbolRef ReleasedValue,
-                                              const ObjCMethodCall &M,
-                                              CheckerContext &C) const {
-  // Try to get the region from which the released value was loaded.
-  // Note that, unlike diagnosing for missing releases, here we don't track
-  // values that must not be released in the state. This is because even if
-  // these values escape, it is still an error under the rules of MRR to
-  // release them in -dealloc.
-  const ObjCPropertyImplDecl *PropImpl =
-      findPropertyOnDeallocatingInstance(ReleasedValue, C);
-
-  if (!PropImpl)
-    return false;
-
-  // If the ivar belongs to a property that must not be released directly
-  // in dealloc, emit a warning.
-  if (getDeallocReleaseRequirement(PropImpl) !=
-      ReleaseRequirement::MustNotReleaseDirectly) {
-    return false;
-  }
-
-  // If the property is readwrite but it shadows a read-only property in its
-  // external interface, treat the property a read-only. If the outside
-  // world cannot write to a property then the internal implementation is free
-  // to make its own convention about whether the value is stored retained
-  // or not. We look up the shadow here rather than in
-  // getDeallocReleaseRequirement() because doing so can be expensive.
-  const ObjCPropertyDecl *PropDecl = findShadowedPropertyDecl(PropImpl);
-  if (PropDecl) {
-    if (PropDecl->isReadOnly())
-      return false;
-  } else {
-    PropDecl = PropImpl->getPropertyDecl();
-  }
-
-  ExplodedNode *ErrNode = C.generateNonFatalErrorNode();
-  if (!ErrNode)
-    return false;
-
-  std::string Buf;
-  llvm::raw_string_ostream OS(Buf);
-
-  assert(PropDecl->getSetterKind() == ObjCPropertyDecl::Weak ||
-         (PropDecl->getSetterKind() == ObjCPropertyDecl::Assign &&
-          !PropDecl->isReadOnly()) ||
-         isReleasedByCIFilterDealloc(PropImpl)
-         );
-
-  const ObjCImplDecl *Container = getContainingObjCImpl(C.getLocationContext());
-  OS << "The '" << *PropImpl->getPropertyIvarDecl()
-     << "' ivar in '" << *Container;
-
-
-  if (isReleasedByCIFilterDealloc(PropImpl)) {
-    OS << "' will be released by '-[CIFilter dealloc]' but also released here";
-  } else {
-    OS << "' was synthesized for ";
-
-    if (PropDecl->getSetterKind() == ObjCPropertyDecl::Weak)
-      OS << "a weak";
-    else
-      OS << "an assign, readwrite";
-
-    OS <<  " property but was released in 'dealloc'";
-  }
-
-  std::unique_ptr<BugReport> BR(
-      new BugReport(*ExtraReleaseBugType, OS.str(), ErrNode));
-  BR->addRange(M.getOriginExpr()->getSourceRange());
-
-  C.emitReport(std::move(BR));
-
-  return true;
-}
-
-/// Emits a warning if the current context is -dealloc and DeallocedValue
-/// must not be directly dealloced in a -dealloc. Returns true if a diagnostic
-/// was emitted.
-bool ObjCDeallocChecker::diagnoseMistakenDealloc(SymbolRef DeallocedValue,
-                                                 const ObjCMethodCall &M,
-                                                 CheckerContext &C) const {
-  // TODO: Apart from unknown/undefined receivers, this may happen when
-  // dealloc is called as a class method. Should we warn?
-  if (!DeallocedValue)
-    return false;
-
-  // Find the property backing the instance variable that M
-  // is dealloc'ing.
-  const ObjCPropertyImplDecl *PropImpl =
-      findPropertyOnDeallocatingInstance(DeallocedValue, C);
-  if (!PropImpl)
-    return false;
-
-  if (getDeallocReleaseRequirement(PropImpl) !=
-      ReleaseRequirement::MustRelease) {
-    return false;
-  }
-
-  ExplodedNode *ErrNode = C.generateErrorNode();
-  if (!ErrNode)
-    return false;
-
-  std::string Buf;
-  llvm::raw_string_ostream OS(Buf);
-
-  OS << "'" << *PropImpl->getPropertyIvarDecl()
-     << "' should be released rather than deallocated";
-
-  std::unique_ptr<BugReport> BR(
-      new BugReport(*MistakenDeallocBugType, OS.str(), ErrNode));
-  BR->addRange(M.getOriginExpr()->getSourceRange());
-
-  C.emitReport(std::move(BR));
-
-  return true;
-}
-
-ObjCDeallocChecker::ObjCDeallocChecker()
-    : NSObjectII(nullptr), SenTestCaseII(nullptr), XCTestCaseII(nullptr),
-      CIFilterII(nullptr) {
-
-  MissingReleaseBugType.reset(
-      new BugType(this, "Missing ivar release (leak)",
-                  categories::MemoryRefCount));
-
-  ExtraReleaseBugType.reset(
-      new BugType(this, "Extra ivar release",
-                  categories::MemoryRefCount));
-
-  MistakenDeallocBugType.reset(
-      new BugType(this, "Mistaken dealloc",
-                  categories::MemoryRefCount));
-}
-
-void ObjCDeallocChecker::initIdentifierInfoAndSelectors(
-    ASTContext &Ctx) const {
-  if (NSObjectII)
-    return;
-
-  NSObjectII = &Ctx.Idents.get("NSObject");
-  SenTestCaseII = &Ctx.Idents.get("SenTestCase");
-  XCTestCaseII = &Ctx.Idents.get("XCTestCase");
-  Block_releaseII = &Ctx.Idents.get("_Block_release");
-  CIFilterII = &Ctx.Idents.get("CIFilter");
-
-  IdentifierInfo *DeallocII = &Ctx.Idents.get("dealloc");
-  IdentifierInfo *ReleaseII = &Ctx.Idents.get("release");
-  DeallocSel = Ctx.Selectors.getSelector(0, &DeallocII);
-  ReleaseSel = Ctx.Selectors.getSelector(0, &ReleaseII);
-}
-
-/// Returns true if M is a call to '[super dealloc]'.
-bool ObjCDeallocChecker::isSuperDeallocMessage(
-    const ObjCMethodCall &M) const {
-  if (M.getOriginExpr()->getReceiverKind() != ObjCMessageExpr::SuperInstance)
-    return false;
-
-  return M.getSelector() == DeallocSel;
-}
-
-/// Returns the ObjCImplDecl containing the method declaration in LCtx.
-const ObjCImplDecl *
-ObjCDeallocChecker::getContainingObjCImpl(const LocationContext *LCtx) const {
-  auto *MD = cast<ObjCMethodDecl>(LCtx->getDecl());
-  return cast<ObjCImplDecl>(MD->getDeclContext());
-}
-
-/// Returns the property that shadowed by PropImpl if one exists and
-/// nullptr otherwise.
-const ObjCPropertyDecl *ObjCDeallocChecker::findShadowedPropertyDecl(
-    const ObjCPropertyImplDecl *PropImpl) const {
-  const ObjCPropertyDecl *PropDecl = PropImpl->getPropertyDecl();
-
-  // Only readwrite properties can shadow.
-  if (PropDecl->isReadOnly())
-    return nullptr;
-
-  auto *CatDecl = dyn_cast<ObjCCategoryDecl>(PropDecl->getDeclContext());
-
-  // Only class extensions can contain shadowing properties.
-  if (!CatDecl || !CatDecl->IsClassExtension())
-    return nullptr;
-
-  IdentifierInfo *ID = PropDecl->getIdentifier();
-  DeclContext::lookup_result R = CatDecl->getClassInterface()->lookup(ID);
-  for (DeclContext::lookup_iterator I = R.begin(), E = R.end(); I != E; ++I) {
-    auto *ShadowedPropDecl = dyn_cast<ObjCPropertyDecl>(*I);
-    if (!ShadowedPropDecl)
-      continue;
-
-    if (ShadowedPropDecl->isInstanceProperty()) {
-      assert(ShadowedPropDecl->isReadOnly());
-      return ShadowedPropDecl;
-    }
-  }
-
-  return nullptr;
-}
-
-/// Add a transition noting the release of the given value.
-void ObjCDeallocChecker::transitionToReleaseValue(CheckerContext &C,
-                                                  SymbolRef Value) const {
-  assert(Value);
-  SymbolRef InstanceSym = getInstanceSymbolFromIvarSymbol(Value);
-  if (!InstanceSym)
-    return;
-  ProgramStateRef InitialState = C.getState();
-
-  ProgramStateRef ReleasedState =
-      removeValueRequiringRelease(InitialState, InstanceSym, Value);
-
-  if (ReleasedState != InitialState) {
-    C.addTransition(ReleasedState);
-  }
-}
-
-/// Remove the Value requiring a release from the tracked set for
-/// Instance and return the resultant state.
-ProgramStateRef ObjCDeallocChecker::removeValueRequiringRelease(
-    ProgramStateRef State, SymbolRef Instance, SymbolRef Value) const {
-  assert(Instance);
-  assert(Value);
-  const ObjCIvarRegion *RemovedRegion = getIvarRegionForIvarSymbol(Value);
-  if (!RemovedRegion)
-    return State;
-
-  const SymbolSet *Unreleased = State->get<UnreleasedIvarMap>(Instance);
-  if (!Unreleased)
-    return State;
-
-  // Mark the value as no longer requiring a release.
-  SymbolSet::Factory &F = State->getStateManager().get_context<SymbolSet>();
-  SymbolSet NewUnreleased = *Unreleased;
-  for (auto &Sym : *Unreleased) {
-    const ObjCIvarRegion *UnreleasedRegion = getIvarRegionForIvarSymbol(Sym);
-    assert(UnreleasedRegion);
-    if (RemovedRegion->getDecl() == UnreleasedRegion->getDecl()) {
-      NewUnreleased = F.remove(NewUnreleased, Sym);
-    }
-  }
-
-  if (NewUnreleased.isEmpty()) {
-    return State->remove<UnreleasedIvarMap>(Instance);
-  }
-
-  return State->set<UnreleasedIvarMap>(Instance, NewUnreleased);
-}
-
-/// Determines whether the instance variable for \p PropImpl must or must not be
-/// released in -dealloc or whether it cannot be determined.
-ReleaseRequirement ObjCDeallocChecker::getDeallocReleaseRequirement(
-    const ObjCPropertyImplDecl *PropImpl) const {
-  const ObjCIvarDecl *IvarDecl;
-  const ObjCPropertyDecl *PropDecl;
-  if (!isSynthesizedRetainableProperty(PropImpl, &IvarDecl, &PropDecl))
-    return ReleaseRequirement::Unknown;
-
-  ObjCPropertyDecl::SetterKind SK = PropDecl->getSetterKind();
-
-  switch (SK) {
-  // Retain and copy setters retain/copy their values before storing and so
-  // the value in their instance variables must be released in -dealloc.
-  case ObjCPropertyDecl::Retain:
-  case ObjCPropertyDecl::Copy:
-    if (isReleasedByCIFilterDealloc(PropImpl))
-      return ReleaseRequirement::MustNotReleaseDirectly;
-
-    if (isNibLoadedIvarWithoutRetain(PropImpl))
-      return ReleaseRequirement::Unknown;
-
-    return ReleaseRequirement::MustRelease;
-
-  case ObjCPropertyDecl::Weak:
-    return ReleaseRequirement::MustNotReleaseDirectly;
-
-  case ObjCPropertyDecl::Assign:
-    // It is common for the ivars for read-only assign properties to
-    // always be stored retained, so their release requirement cannot be
-    // be determined.
-    if (PropDecl->isReadOnly())
-      return ReleaseRequirement::Unknown;
-
-    return ReleaseRequirement::MustNotReleaseDirectly;
-  }
-  llvm_unreachable("Unrecognized setter kind");
-}
-
-/// Returns the released value if M is a call a setter that releases
-/// and nils out its underlying instance variable.
-SymbolRef
-ObjCDeallocChecker::getValueReleasedByNillingOut(const ObjCMethodCall &M,
-                                                 CheckerContext &C) const {
-  SVal ReceiverVal = M.getReceiverSVal();
-  if (!ReceiverVal.isValid())
-    return nullptr;
-
-  if (M.getNumArgs() == 0)
-    return nullptr;
-
-  if (!M.getArgExpr(0)->getType()->isObjCRetainableType())
-    return nullptr;
-
-  // Is the first argument nil?
-  SVal Arg = M.getArgSVal(0);
-  ProgramStateRef notNilState, nilState;
-  std::tie(notNilState, nilState) =
-      M.getState()->assume(Arg.castAs<DefinedOrUnknownSVal>());
-  if (!(nilState && !notNilState))
-    return nullptr;
-
-  const ObjCPropertyDecl *Prop = M.getAccessedProperty();
-  if (!Prop)
-    return nullptr;
-
-  ObjCIvarDecl *PropIvarDecl = Prop->getPropertyIvarDecl();
-  if (!PropIvarDecl)
-    return nullptr;
-
-  ProgramStateRef State = C.getState();
-
-  SVal LVal = State->getLValue(PropIvarDecl, ReceiverVal);
-  Optional<Loc> LValLoc = LVal.getAs<Loc>();
-  if (!LValLoc)
-    return nullptr;
-
-  SVal CurrentValInIvar = State->getSVal(LValLoc.getValue());
-  return CurrentValInIvar.getAsSymbol();
-}
-
-/// Returns true if the current context is a call to -dealloc and false
-/// otherwise. If true, it also sets SelfValOut to the value of
-/// 'self'.
-bool ObjCDeallocChecker::isInInstanceDealloc(const CheckerContext &C,
-                                             SVal &SelfValOut) const {
-  return isInInstanceDealloc(C, C.getLocationContext(), SelfValOut);
-}
-
-/// Returns true if LCtx is a call to -dealloc and false
-/// otherwise. If true, it also sets SelfValOut to the value of
-/// 'self'.
-bool ObjCDeallocChecker::isInInstanceDealloc(const CheckerContext &C,
-                                             const LocationContext *LCtx,
-                                             SVal &SelfValOut) const {
-  auto *MD = dyn_cast<ObjCMethodDecl>(LCtx->getDecl());
-  if (!MD || !MD->isInstanceMethod() || MD->getSelector() != DeallocSel)
-    return false;
-
-  const ImplicitParamDecl *SelfDecl = LCtx->getSelfDecl();
-  assert(SelfDecl && "No self in -dealloc?");
-
-  ProgramStateRef State = C.getState();
-  SelfValOut = State->getSVal(State->getRegion(SelfDecl, LCtx));
-  return true;
-}
-
-/// Returns true if there is a call to -dealloc anywhere on the stack and false
-/// otherwise. If true, it also sets InstanceValOut to the value of
-/// 'self' in the frame for -dealloc.
-bool ObjCDeallocChecker::instanceDeallocIsOnStack(const CheckerContext &C,
-                                                  SVal &InstanceValOut) const {
-  const LocationContext *LCtx = C.getLocationContext();
-
-  while (LCtx) {
-    if (isInInstanceDealloc(C, LCtx, InstanceValOut))
-      return true;
-
-    LCtx = LCtx->getParent();
-  }
-
-  return false;
-}
-
-/// Returns true if the ID is a class in which which is known to have
-/// a separate teardown lifecycle. In this case, -dealloc warnings
-/// about missing releases should be suppressed.
-bool ObjCDeallocChecker::classHasSeparateTeardown(
-    const ObjCInterfaceDecl *ID) const {
-  // Suppress if the class is not a subclass of NSObject.
-  for ( ; ID ; ID = ID->getSuperClass()) {
-    IdentifierInfo *II = ID->getIdentifier();
-
-    if (II == NSObjectII)
-      return false;
-
-    // FIXME: For now, ignore classes that subclass SenTestCase and XCTestCase,
-    // as these don't need to implement -dealloc.  They implement tear down in
-    // another way, which we should try and catch later.
-    //  http://llvm.org/bugs/show_bug.cgi?id=3187
-    if (II == XCTestCaseII || II == SenTestCaseII)
-      return true;
-  }
-
-  return true;
-}
-
-/// The -dealloc method in CIFilter highly unusual in that is will release
-/// instance variables belonging to its *subclasses* if the variable name
-/// starts with "input" or backs a property whose name starts with "input".
-/// Subclasses should not release these ivars in their own -dealloc method --
-/// doing so could result in an over release.
-///
-/// This method returns true if the property will be released by
-/// -[CIFilter dealloc].
-bool ObjCDeallocChecker::isReleasedByCIFilterDealloc(
-    const ObjCPropertyImplDecl *PropImpl) const {
-  assert(PropImpl->getPropertyIvarDecl());
-  StringRef PropName = PropImpl->getPropertyDecl()->getName();
-  StringRef IvarName = PropImpl->getPropertyIvarDecl()->getName();
-
-  const char *ReleasePrefix = "input";
-  if (!(PropName.startswith(ReleasePrefix) ||
-        IvarName.startswith(ReleasePrefix))) {
-    return false;
-  }
-
-  const ObjCInterfaceDecl *ID =
-      PropImpl->getPropertyIvarDecl()->getContainingInterface();
-  for ( ; ID ; ID = ID->getSuperClass()) {
-    IdentifierInfo *II = ID->getIdentifier();
-    if (II == CIFilterII)
-      return true;
-  }
-
-  return false;
-}
-
-/// Returns whether the ivar backing the property is an IBOutlet that
-/// has its value set by nib loading code without retaining the value.
-///
-/// On macOS, if there is no setter, the nib-loading code sets the ivar
-/// directly, without retaining the value,
-///
-/// On iOS and its derivatives, the nib-loading code will call
-/// -setValue:forKey:, which retains the value before directly setting the ivar.
-bool ObjCDeallocChecker::isNibLoadedIvarWithoutRetain(
-    const ObjCPropertyImplDecl *PropImpl) const {
-  const ObjCIvarDecl *IvarDecl = PropImpl->getPropertyIvarDecl();
-  if (!IvarDecl->hasAttr<IBOutletAttr>())
-    return false;
-
-  const llvm::Triple &Target =
-      IvarDecl->getASTContext().getTargetInfo().getTriple();
-
-  if (!Target.isMacOSX())
-    return false;
-
-  if (PropImpl->getPropertyDecl()->getSetterMethodDecl())
-    return false;
-
-  return true;
-}
-
-void ento::registerObjCDeallocChecker(CheckerManager &Mgr) {
-  const LangOptions &LangOpts = Mgr.getLangOpts();
-  // These checker only makes sense under MRR.
-  if (LangOpts.getGC() == LangOptions::GCOnly || LangOpts.ObjCAutoRefCount)
-    return;
-
-  Mgr.registerChecker<ObjCDeallocChecker>();
-}