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1//=== StackAddrEscapeChecker.cpp ----------------------------------*- 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-exception6//7//===----------------------------------------------------------------------===//8//9// This file defines stack address leak checker, which checks if an invalid10// stack address is stored into a global or heap location. See CERT DCL30-C.11//12//===----------------------------------------------------------------------===//13 14#include "clang/AST/ExprCXX.h"15#include "clang/Basic/SourceManager.h"16#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"17#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"18#include "clang/StaticAnalyzer/Core/Checker.h"19#include "clang/StaticAnalyzer/Core/CheckerManager.h"20#include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"21#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"22#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"23#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"24#include "llvm/ADT/STLExtras.h"25#include "llvm/ADT/SmallPtrSet.h"26#include "llvm/Support/raw_ostream.h"27using namespace clang;28using namespace ento;29 30namespace {31class StackAddrEscapeChecker32    : public CheckerFamily<check::PreCall, check::PreStmt<ReturnStmt>,33                           check::EndFunction> {34  mutable IdentifierInfo *dispatch_semaphore_tII = nullptr;35 36public:37  StringRef getDebugTag() const override { return "StackAddrEscapeChecker"; }38 39  CheckerFrontend StackAddrEscape;40  CheckerFrontend StackAddrAsyncEscape;41 42  const BugType StackLeak{&StackAddrEscape,43                          "Stack address leaks outside of stack frame"};44  const BugType ReturnStack{&StackAddrEscape,45                            "Return of address to stack-allocated memory"};46  const BugType CapturedStackAsync{47      &StackAddrAsyncEscape, "Address of stack-allocated memory is captured"};48 49  void checkPreCall(const CallEvent &Call, CheckerContext &C) const;50  void checkPreStmt(const ReturnStmt *RS, CheckerContext &C) const;51  void checkEndFunction(const ReturnStmt *RS, CheckerContext &Ctx) const;52 53private:54  void checkAsyncExecutedBlockCaptures(const BlockDataRegion &B,55                                       CheckerContext &C) const;56  void EmitReturnLeakError(CheckerContext &C, const MemRegion *LeakedRegion,57                           const Expr *RetE) const;58  bool isSemaphoreCaptured(const BlockDecl &B) const;59  static SourceRange genName(raw_ostream &os, const MemRegion *R,60                             ASTContext &Ctx);61  static SmallVector<std::pair<const MemRegion *, const StackSpaceRegion *>, 4>62  getCapturedStackRegions(const BlockDataRegion &B, CheckerContext &C);63  static bool isNotInCurrentFrame(const StackSpaceRegion *MS,64                                  CheckerContext &C);65};66} // namespace67 68SourceRange StackAddrEscapeChecker::genName(raw_ostream &os, const MemRegion *R,69                                            ASTContext &Ctx) {70  // Get the base region, stripping away fields and elements.71  R = R->getBaseRegion();72  SourceManager &SM = Ctx.getSourceManager();73  SourceRange range;74  os << "Address of ";75 76  // Check if the region is a compound literal.77  if (const auto *CR = dyn_cast<CompoundLiteralRegion>(R)) {78    const CompoundLiteralExpr *CL = CR->getLiteralExpr();79    os << "stack memory associated with a compound literal "80          "declared on line "81       << SM.getExpansionLineNumber(CL->getBeginLoc());82    range = CL->getSourceRange();83  } else if (const auto *AR = dyn_cast<AllocaRegion>(R)) {84    const Expr *ARE = AR->getExpr();85    SourceLocation L = ARE->getBeginLoc();86    range = ARE->getSourceRange();87    os << "stack memory allocated by call to alloca() on line "88       << SM.getExpansionLineNumber(L);89  } else if (const auto *BR = dyn_cast<BlockDataRegion>(R)) {90    const BlockDecl *BD = BR->getCodeRegion()->getDecl();91    SourceLocation L = BD->getBeginLoc();92    range = BD->getSourceRange();93    os << "stack-allocated block declared on line "94       << SM.getExpansionLineNumber(L);95  } else if (const auto *VR = dyn_cast<VarRegion>(R)) {96    os << "stack memory associated with local variable '" << VR->getString()97       << '\'';98    range = VR->getDecl()->getSourceRange();99  } else if (const auto *LER = dyn_cast<CXXLifetimeExtendedObjectRegion>(R)) {100    QualType Ty = LER->getValueType().getLocalUnqualifiedType();101    os << "stack memory associated with temporary object of type '";102    Ty.print(os, Ctx.getPrintingPolicy());103    os << "' lifetime extended by local variable";104    if (const IdentifierInfo *ID = LER->getExtendingDecl()->getIdentifier())105      os << " '" << ID->getName() << '\'';106    range = LER->getExpr()->getSourceRange();107  } else if (const auto *TOR = dyn_cast<CXXTempObjectRegion>(R)) {108    QualType Ty = TOR->getValueType().getLocalUnqualifiedType();109    os << "stack memory associated with temporary object of type '";110    Ty.print(os, Ctx.getPrintingPolicy());111    os << "'";112    range = TOR->getExpr()->getSourceRange();113  } else {114    llvm_unreachable("Invalid region in ReturnStackAddressChecker.");115  }116 117  return range;118}119 120bool StackAddrEscapeChecker::isNotInCurrentFrame(const StackSpaceRegion *MS,121                                                 CheckerContext &C) {122  return MS->getStackFrame() != C.getStackFrame();123}124 125bool StackAddrEscapeChecker::isSemaphoreCaptured(const BlockDecl &B) const {126  if (!dispatch_semaphore_tII)127    dispatch_semaphore_tII = &B.getASTContext().Idents.get("dispatch_semaphore_t");128  for (const auto &C : B.captures()) {129    const auto *T = C.getVariable()->getType()->getAs<TypedefType>();130    if (T && T->getDecl()->getIdentifier() == dispatch_semaphore_tII)131      return true;132  }133  return false;134}135 136SmallVector<std::pair<const MemRegion *, const StackSpaceRegion *>, 4>137StackAddrEscapeChecker::getCapturedStackRegions(const BlockDataRegion &B,138                                                CheckerContext &C) {139  SmallVector<std::pair<const MemRegion *, const StackSpaceRegion *>, 4>140      Regions;141  ProgramStateRef State = C.getState();142  for (auto Var : B.referenced_vars()) {143    SVal Val = State->getSVal(Var.getCapturedRegion());144    if (const MemRegion *Region = Val.getAsRegion()) {145      if (const auto *Space =146              Region->getMemorySpaceAs<StackSpaceRegion>(State)) {147        Regions.emplace_back(Region, Space);148      }149    }150  }151  return Regions;152}153 154static void EmitReturnedAsPartOfError(llvm::raw_ostream &OS, SVal ReturnedVal,155                                      const MemRegion *LeakedRegion) {156  if (const MemRegion *ReturnedRegion = ReturnedVal.getAsRegion()) {157    if (isa<BlockDataRegion>(ReturnedRegion)) {158      OS << " is captured by a returned block";159      return;160    }161  }162 163  // Generic message164  OS << " returned to caller";165}166 167void StackAddrEscapeChecker::EmitReturnLeakError(CheckerContext &C,168                                                 const MemRegion *R,169                                                 const Expr *RetE) const {170  ExplodedNode *N = C.generateNonFatalErrorNode();171  if (!N)172    return;173 174  // Generate a report for this bug.175  SmallString<128> buf;176  llvm::raw_svector_ostream os(buf);177 178  // Error message formatting179  SourceRange range = genName(os, R, C.getASTContext());180  EmitReturnedAsPartOfError(os, C.getSVal(RetE), R);181 182  auto report =183      std::make_unique<PathSensitiveBugReport>(ReturnStack, os.str(), N);184  report->addRange(RetE->getSourceRange());185  if (range.isValid())186    report->addRange(range);187  C.emitReport(std::move(report));188}189 190void StackAddrEscapeChecker::checkAsyncExecutedBlockCaptures(191    const BlockDataRegion &B, CheckerContext &C) const {192  // There is a not-too-uncommon idiom193  // where a block passed to dispatch_async captures a semaphore194  // and then the thread (which called dispatch_async) is blocked on waiting195  // for the completion of the execution of the block196  // via dispatch_semaphore_wait. To avoid false-positives (for now)197  // we ignore all the blocks which have captured198  // a variable of the type "dispatch_semaphore_t".199  if (isSemaphoreCaptured(*B.getDecl()))200    return;201  auto Regions = getCapturedStackRegions(B, C);202  for (const MemRegion *Region : llvm::make_first_range(Regions)) {203    // The block passed to dispatch_async may capture another block204    // created on the stack. However, there is no leak in this situaton,205    // no matter if ARC or no ARC is enabled:206    // dispatch_async copies the passed "outer" block (via Block_copy)207    // and if the block has captured another "inner" block,208    // the "inner" block will be copied as well.209    if (isa<BlockDataRegion>(Region))210      continue;211    ExplodedNode *N = C.generateNonFatalErrorNode();212    if (!N)213      continue;214    SmallString<128> Buf;215    llvm::raw_svector_ostream Out(Buf);216    SourceRange Range = genName(Out, Region, C.getASTContext());217    Out << " is captured by an asynchronously-executed block";218    auto Report = std::make_unique<PathSensitiveBugReport>(CapturedStackAsync,219                                                           Out.str(), N);220    if (Range.isValid())221      Report->addRange(Range);222    C.emitReport(std::move(Report));223  }224}225 226void StackAddrEscapeChecker::checkPreCall(const CallEvent &Call,227                                          CheckerContext &C) const {228  if (!StackAddrAsyncEscape.isEnabled())229    return;230  if (!Call.isGlobalCFunction("dispatch_after") &&231      !Call.isGlobalCFunction("dispatch_async"))232    return;233  for (unsigned Idx = 0, NumArgs = Call.getNumArgs(); Idx < NumArgs; ++Idx) {234    if (const BlockDataRegion *B = dyn_cast_or_null<BlockDataRegion>(235            Call.getArgSVal(Idx).getAsRegion()))236      checkAsyncExecutedBlockCaptures(*B, C);237  }238}239 240/// A visitor made for use with a ScanReachableSymbols scanner, used241/// for finding stack regions within an SVal that live on the current242/// stack frame of the given checker context. This visitor excludes243/// NonParamVarRegion that data is bound to in a BlockDataRegion's244/// bindings, since these are likely uninteresting, e.g., in case a245/// temporary is constructed on the stack, but it captures values246/// that would leak.247class FindStackRegionsSymbolVisitor final : public SymbolVisitor {248  CheckerContext &Ctxt;249  const StackFrameContext *PoppedStackFrame;250  SmallVectorImpl<const MemRegion *> &EscapingStackRegions;251  llvm::SmallPtrSet<const MemRegion *, 16> VisitedRegions;252 253public:254  explicit FindStackRegionsSymbolVisitor(255      CheckerContext &Ctxt,256      SmallVectorImpl<const MemRegion *> &StorageForStackRegions)257      : Ctxt(Ctxt), PoppedStackFrame(Ctxt.getStackFrame()),258        EscapingStackRegions(StorageForStackRegions) {}259 260  bool VisitSymbol(SymbolRef sym) override { return true; }261 262  bool VisitMemRegion(const MemRegion *MR) override {263    if (!VisitedRegions.insert(MR).second)264      return true;265 266    SaveIfEscapes(MR);267 268    if (const BlockDataRegion *BDR = MR->getAs<BlockDataRegion>())269      return VisitBlockDataRegionCaptures(BDR);270 271    return true;272  }273 274private:275  void SaveIfEscapes(const MemRegion *MR) {276    const auto *SSR = MR->getMemorySpaceAs<StackSpaceRegion>(Ctxt.getState());277 278    if (!SSR)279      return;280 281    const StackFrameContext *CapturedSFC = SSR->getStackFrame();282    if (CapturedSFC == PoppedStackFrame ||283        PoppedStackFrame->isParentOf(CapturedSFC))284      EscapingStackRegions.push_back(MR);285  }286 287  bool VisitBlockDataRegionCaptures(const BlockDataRegion *BDR) {288    for (auto Var : BDR->referenced_vars()) {289      SVal Val = Ctxt.getState()->getSVal(Var.getCapturedRegion());290      const MemRegion *Region = Val.getAsRegion();291      if (Region) {292        SaveIfEscapes(Region);293        VisitMemRegion(Region);294      }295    }296 297    return false;298  }299};300 301/// Given some memory regions that are flagged by FindStackRegionsSymbolVisitor,302/// this function filters out memory regions that are being returned that are303/// likely not true leaks:304/// 1. If returning a block data region that has stack memory space305/// 2. If returning a constructed object that has stack memory space306static SmallVector<const MemRegion *> FilterReturnExpressionLeaks(307    const SmallVectorImpl<const MemRegion *> &MaybeEscaped, CheckerContext &C,308    const Expr *RetE, SVal &RetVal) {309 310  SmallVector<const MemRegion *> WillEscape;311 312  const MemRegion *RetRegion = RetVal.getAsRegion();313 314  // Returning a record by value is fine. (In this case, the returned315  // expression will be a copy-constructor, possibly wrapped in an316  // ExprWithCleanups node.)317  if (const ExprWithCleanups *Cleanup = dyn_cast<ExprWithCleanups>(RetE))318    RetE = Cleanup->getSubExpr();319  bool IsConstructExpr =320      isa<CXXConstructExpr>(RetE) && RetE->getType()->isRecordType();321 322  // The CK_CopyAndAutoreleaseBlockObject cast causes the block to be copied323  // so the stack address is not escaping here.324  bool IsCopyAndAutoreleaseBlockObj = false;325  if (const auto *ICE = dyn_cast<ImplicitCastExpr>(RetE)) {326    IsCopyAndAutoreleaseBlockObj =327        isa_and_nonnull<BlockDataRegion>(RetRegion) &&328        ICE->getCastKind() == CK_CopyAndAutoreleaseBlockObject;329  }330 331  for (const MemRegion *MR : MaybeEscaped) {332    if (RetRegion == MR && (IsCopyAndAutoreleaseBlockObj || IsConstructExpr))333      continue;334 335    WillEscape.push_back(MR);336  }337 338  return WillEscape;339}340 341/// For use in finding regions that live on the checker context's current342/// stack frame, deep in the SVal representing the return value.343static SmallVector<const MemRegion *>344FindEscapingStackRegions(CheckerContext &C, const Expr *RetE, SVal RetVal) {345  SmallVector<const MemRegion *> FoundStackRegions;346 347  FindStackRegionsSymbolVisitor Finder(C, FoundStackRegions);348  ScanReachableSymbols Scanner(C.getState(), Finder);349  Scanner.scan(RetVal);350 351  return FilterReturnExpressionLeaks(FoundStackRegions, C, RetE, RetVal);352}353 354void StackAddrEscapeChecker::checkPreStmt(const ReturnStmt *RS,355                                          CheckerContext &C) const {356  if (!StackAddrEscape.isEnabled())357    return;358 359  const Expr *RetE = RS->getRetValue();360  if (!RetE)361    return;362  RetE = RetE->IgnoreParens();363 364  SVal V = C.getSVal(RetE);365 366  SmallVector<const MemRegion *> EscapedStackRegions =367      FindEscapingStackRegions(C, RetE, V);368 369  for (const MemRegion *ER : EscapedStackRegions)370    EmitReturnLeakError(C, ER, RetE);371}372 373static const MemSpaceRegion *getStackOrGlobalSpaceRegion(ProgramStateRef State,374                                                         const MemRegion *R) {375  assert(R);376  if (const auto *MemSpace = R->getMemorySpace(State);377      isa<StackSpaceRegion, GlobalsSpaceRegion>(MemSpace))378    return MemSpace;379 380  // If R describes a lambda capture, it will be a symbolic region381  // referring to a field region of another symbolic region.382  if (const auto *SymReg = R->getBaseRegion()->getAs<SymbolicRegion>()) {383    if (const auto *OriginReg = SymReg->getSymbol()->getOriginRegion())384      return getStackOrGlobalSpaceRegion(State, OriginReg);385  }386  return nullptr;387}388 389static const MemRegion *getOriginBaseRegion(const MemRegion *Reg) {390  Reg = Reg->getBaseRegion();391  while (const auto *SymReg = dyn_cast<SymbolicRegion>(Reg)) {392    const auto *OriginReg = SymReg->getSymbol()->getOriginRegion();393    if (!OriginReg)394      break;395    Reg = OriginReg->getBaseRegion();396  }397  return Reg;398}399 400static std::optional<std::string> printReferrer(ProgramStateRef State,401                                                const MemRegion *Referrer) {402  assert(Referrer);403  const StringRef ReferrerMemorySpace = [](const MemSpaceRegion *Space) {404    if (isa<StaticGlobalSpaceRegion>(Space))405      return "static";406    if (isa<GlobalsSpaceRegion>(Space))407      return "global";408    assert(isa<StackSpaceRegion>(Space));409    // This case covers top-level and inlined analyses.410    return "caller";411  }(getStackOrGlobalSpaceRegion(State, Referrer));412 413  while (!Referrer->canPrintPretty()) {414    if (const auto *SymReg = dyn_cast<SymbolicRegion>(Referrer);415        SymReg && SymReg->getSymbol()->getOriginRegion()) {416      Referrer = SymReg->getSymbol()->getOriginRegion()->getBaseRegion();417    } else if (isa<CXXThisRegion>(Referrer)) {418      // Skip members of a class, it is handled in CheckExprLifetime.cpp as419      // warn_bind_ref_member_to_parameter or420      // warn_init_ptr_member_to_parameter_addr421      return std::nullopt;422    } else if (isa<AllocaRegion>(Referrer)) {423      // Skip alloca() regions, they indicate advanced memory management424      // and higher likelihood of CSA false positives.425      return std::nullopt;426    } else {427      assert(false && "Unexpected referrer region type.");428      return std::nullopt;429    }430  }431  assert(Referrer);432  assert(Referrer->canPrintPretty());433 434  std::string buf;435  llvm::raw_string_ostream os(buf);436  os << ReferrerMemorySpace << " variable ";437  Referrer->printPretty(os);438  return buf;439}440 441/// Check whether \p Region refers to a freshly minted symbol after an opaque442/// function call.443static bool isInvalidatedSymbolRegion(const MemRegion *Region) {444  const auto *SymReg = Region->getAs<SymbolicRegion>();445  if (!SymReg)446    return false;447  SymbolRef Symbol = SymReg->getSymbol();448 449  const auto *DerS = dyn_cast<SymbolDerived>(Symbol);450  return DerS && isa_and_nonnull<SymbolConjured>(DerS->getParentSymbol());451}452 453void StackAddrEscapeChecker::checkEndFunction(const ReturnStmt *RS,454                                              CheckerContext &Ctx) const {455  if (!StackAddrEscape.isEnabled())456    return;457 458  ExplodedNode *Node = Ctx.getPredecessor();459 460  bool ExitingTopFrame =461      Ctx.getPredecessor()->getLocationContext()->inTopFrame();462 463  if (ExitingTopFrame &&464      Node->getLocation().getTag() == ExprEngine::cleanupNodeTag() &&465      Node->getFirstPred()) {466    // When finishing analysis of a top-level function, engine proactively467    // removes dead symbols thus preventing this checker from looking through468    // the output parameters. Take 1 step back, to the node where these symbols469    // and their bindings are still present470    Node = Node->getFirstPred();471  }472 473  // Iterate over all bindings to global variables and see if it contains474  // a memory region in the stack space.475  class CallBack : public StoreManager::BindingsHandler {476  private:477    CheckerContext &Ctx;478    ProgramStateRef State;479    const StackFrameContext *PoppedFrame;480    const bool TopFrame;481 482    /// Look for stack variables referring to popped stack variables.483    /// Returns true only if it found some dangling stack variables484    /// referred by an other stack variable from different stack frame.485    bool checkForDanglingStackVariable(const MemRegion *Referrer,486                                       const MemRegion *Referred) {487      const auto *ReferrerMemSpace =488          getStackOrGlobalSpaceRegion(State, Referrer);489      const auto *ReferredMemSpace =490          Referred->getMemorySpaceAs<StackSpaceRegion>(State);491 492      if (!ReferrerMemSpace || !ReferredMemSpace)493        return false;494 495      const auto *ReferrerStackSpace =496          ReferrerMemSpace->getAs<StackSpaceRegion>();497 498      if (!ReferrerStackSpace)499        return false;500 501      if (const auto *ReferredFrame = ReferredMemSpace->getStackFrame();502          ReferredFrame != PoppedFrame) {503        return false;504      }505 506      if (ReferrerStackSpace->getStackFrame()->isParentOf(PoppedFrame)) {507        V.emplace_back(Referrer, Referred);508        return true;509      }510      if (isa<StackArgumentsSpaceRegion>(ReferrerMemSpace) &&511          // Not a simple ptr (int*) but something deeper, e.g. int**512          isa<SymbolicRegion>(Referrer->getBaseRegion()) &&513          ReferrerStackSpace->getStackFrame() == PoppedFrame && TopFrame) {514        // Output parameter of a top-level function515        V.emplace_back(Referrer, Referred);516        return true;517      }518      return false;519    }520 521    // Keep track of the variables that were invalidated through an opaque522    // function call. Even if the initial values of such variables were bound to523    // an address of a local variable, we cannot claim anything now, at the524    // function exit, so skip them to avoid false positives.525    void recordInInvalidatedRegions(const MemRegion *Region) {526      if (isInvalidatedSymbolRegion(Region))527        ExcludedRegions.insert(getOriginBaseRegion(Region));528    }529 530  public:531    SmallVector<std::pair<const MemRegion *, const MemRegion *>, 10> V;532    // ExcludedRegions are skipped from reporting.533    // I.e., if a referrer in this set, skip the related bug report.534    // It is useful to avoid false positive for the variables that were535    // reset to a conjured value after an opaque function call.536    llvm::SmallPtrSet<const MemRegion *, 4> ExcludedRegions;537 538    CallBack(CheckerContext &CC, bool TopFrame)539        : Ctx(CC), State(CC.getState()), PoppedFrame(CC.getStackFrame()),540          TopFrame(TopFrame) {}541 542    bool HandleBinding(StoreManager &SMgr, Store S, const MemRegion *Region,543                       SVal Val) override {544      recordInInvalidatedRegions(Region);545      const MemRegion *VR = Val.getAsRegion();546      if (!VR)547        return true;548 549      if (checkForDanglingStackVariable(Region, VR))550        return true;551 552      // Check the globals for the same.553      if (!isa_and_nonnull<GlobalsSpaceRegion>(554              getStackOrGlobalSpaceRegion(State, Region)))555        return true;556 557      if (VR) {558        if (const auto *S = VR->getMemorySpaceAs<StackSpaceRegion>(State);559            S && !isNotInCurrentFrame(S, Ctx)) {560          V.emplace_back(Region, VR);561        }562      }563      return true;564    }565  };566 567  CallBack Cb(Ctx, ExitingTopFrame);568  ProgramStateRef State = Node->getState();569  State->getStateManager().getStoreManager().iterBindings(State->getStore(),570                                                          Cb);571 572  if (Cb.V.empty())573    return;574 575  // Generate an error node.576  ExplodedNode *N = Ctx.generateNonFatalErrorNode(State, Node);577  if (!N)578    return;579 580  for (const auto &P : Cb.V) {581    const MemRegion *Referrer = P.first->getBaseRegion();582    const MemRegion *Referred = P.second;583    if (Cb.ExcludedRegions.contains(getOriginBaseRegion(Referrer))) {584      continue;585    }586 587    // Generate a report for this bug.588    const StringRef CommonSuffix =589        " upon returning to the caller.  This will be a dangling reference";590    SmallString<128> Buf;591    llvm::raw_svector_ostream Out(Buf);592    const SourceRange Range = genName(Out, Referred, Ctx.getASTContext());593 594    if (isa<CXXTempObjectRegion, CXXLifetimeExtendedObjectRegion>(Referrer)) {595      Out << " is still referred to by a temporary object on the stack"596          << CommonSuffix;597      auto Report =598          std::make_unique<PathSensitiveBugReport>(StackLeak, Out.str(), N);599      if (Range.isValid())600        Report->addRange(Range);601      Ctx.emitReport(std::move(Report));602      return;603    }604 605    auto ReferrerVariable = printReferrer(State, Referrer);606    if (!ReferrerVariable) {607      continue;608    }609 610    Out << " is still referred to by the " << *ReferrerVariable << CommonSuffix;611    auto Report =612        std::make_unique<PathSensitiveBugReport>(StackLeak, Out.str(), N);613    if (Range.isValid())614      Report->addRange(Range);615 616    Ctx.emitReport(std::move(Report));617  }618}619 620#define REGISTER_CHECKER(NAME)                                                 \621  void ento::register##NAME##Checker(CheckerManager &Mgr) {                    \622    Mgr.getChecker<StackAddrEscapeChecker>()->NAME.enable(Mgr);                \623  }                                                                            \624                                                                               \625  bool ento::shouldRegister##NAME##Checker(const CheckerManager &) {           \626    return true;                                                               \627  }628 629REGISTER_CHECKER(StackAddrEscape)630REGISTER_CHECKER(StackAddrAsyncEscape)631