Import LLVM 10.0.0 release including clang, lld and lldb.

ok hackroom
tested by plenty

1 files changed, 3428 insertions, 0 deletions

diff --git a/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp b/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
new file mode 100644
index 00000000000..09306383d53
--- /dev/null
+++ b/gnu/llvm/clang/lib/StaticAnalyzer/Checkers/MallocChecker.cpp
@@ -0,0 +1,3428 @@
+//=== MallocChecker.cpp - A malloc/free checker -------------------*- C++ -*--//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a variety of memory management related checkers, such as
+// leak, double free, and use-after-free.
+//
+// The following checkers are defined here:
+//
+//   * MallocChecker
+//       Despite its name, it models all sorts of memory allocations and
+//       de- or reallocation, including but not limited to malloc, free,
+//       relloc, new, delete. It also reports on a variety of memory misuse
+//       errors.
+//       Many other checkers interact very closely with this checker, in fact,
+//       most are merely options to this one. Other checkers may register
+//       MallocChecker, but do not enable MallocChecker's reports (more details
+//       to follow around its field, ChecksEnabled).
+//       It also has a boolean "Optimistic" checker option, which if set to true
+//       will cause the checker to model user defined memory management related
+//       functions annotated via the attribute ownership_takes, ownership_holds
+//       and ownership_returns.
+//
+//   * NewDeleteChecker
+//       Enables the modeling of new, new[], delete, delete[] in MallocChecker,
+//       and checks for related double-free and use-after-free errors.
+//
+//   * NewDeleteLeaksChecker
+//       Checks for leaks related to new, new[], delete, delete[].
+//       Depends on NewDeleteChecker.
+//
+//   * MismatchedDeallocatorChecker
+//       Enables checking whether memory is deallocated with the correspending
+//       allocation function in MallocChecker, such as malloc() allocated
+//       regions are only freed by free(), new by delete, new[] by delete[].
+//
+//  InnerPointerChecker interacts very closely with MallocChecker, but unlike
+//  the above checkers, it has it's own file, hence the many InnerPointerChecker
+//  related headers and non-static functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
+#include "InterCheckerAPI.h"
+#include "clang/AST/Attr.h"
+#include "clang/AST/ParentMap.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/TargetInfo.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
+#include "clang/StaticAnalyzer/Core/BugReporter/CommonBugCategories.h"
+#include "clang/StaticAnalyzer/Core/Checker.h"
+#include "clang/StaticAnalyzer/Core/CheckerManager.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/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+#include "AllocationState.h"
+#include <climits>
+#include <utility>
+
+using namespace clang;
+using namespace ento;
+
+//===----------------------------------------------------------------------===//
+// The types of allocation we're modeling.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+// Used to check correspondence between allocators and deallocators.
+enum AllocationFamily {
+  AF_None,
+  AF_Malloc,
+  AF_CXXNew,
+  AF_CXXNewArray,
+  AF_IfNameIndex,
+  AF_Alloca,
+  AF_InnerBuffer
+};
+
+struct MemFunctionInfoTy;
+
+} // end of anonymous namespace
+
+/// Determine family of a deallocation expression.
+static AllocationFamily
+getAllocationFamily(const MemFunctionInfoTy &MemFunctionInfo, CheckerContext &C,
+                    const Stmt *S);
+
+/// Print names of allocators and deallocators.
+///
+/// \returns true on success.
+static bool printAllocDeallocName(raw_ostream &os, CheckerContext &C,
+                                  const Expr *E);
+
+/// Print expected name of an allocator based on the deallocator's
+/// family derived from the DeallocExpr.
+static void printExpectedAllocName(raw_ostream &os,
+                                   const MemFunctionInfoTy &MemFunctionInfo,
+                                   CheckerContext &C, const Expr *E);
+
+/// Print expected name of a deallocator based on the allocator's
+/// family.
+static void printExpectedDeallocName(raw_ostream &os, AllocationFamily Family);
+
+//===----------------------------------------------------------------------===//
+// The state of a symbol, in terms of memory management.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class RefState {
+  enum Kind {
+    // Reference to allocated memory.
+    Allocated,
+    // Reference to zero-allocated memory.
+    AllocatedOfSizeZero,
+    // Reference to released/freed memory.
+    Released,
+    // The responsibility for freeing resources has transferred from
+    // this reference. A relinquished symbol should not be freed.
+    Relinquished,
+    // We are no longer guaranteed to have observed all manipulations
+    // of this pointer/memory. For example, it could have been
+    // passed as a parameter to an opaque function.
+    Escaped
+  };
+
+  const Stmt *S;
+
+  Kind K;
+  AllocationFamily Family;
+
+  RefState(Kind k, const Stmt *s, AllocationFamily family)
+      : S(s), K(k), Family(family) {
+    assert(family != AF_None);
+  }
+
+public:
+  bool isAllocated() const { return K == Allocated; }
+  bool isAllocatedOfSizeZero() const { return K == AllocatedOfSizeZero; }
+  bool isReleased() const { return K == Released; }
+  bool isRelinquished() const { return K == Relinquished; }
+  bool isEscaped() const { return K == Escaped; }
+  AllocationFamily getAllocationFamily() const { return Family; }
+  const Stmt *getStmt() const { return S; }
+
+  bool operator==(const RefState &X) const {
+    return K == X.K && S == X.S && Family == X.Family;
+  }
+
+  static RefState getAllocated(AllocationFamily family, const Stmt *s) {
+    return RefState(Allocated, s, family);
+  }
+  static RefState getAllocatedOfSizeZero(const RefState *RS) {
+    return RefState(AllocatedOfSizeZero, RS->getStmt(),
+                    RS->getAllocationFamily());
+  }
+  static RefState getReleased(AllocationFamily family, const Stmt *s) {
+    return RefState(Released, s, family);
+  }
+  static RefState getRelinquished(AllocationFamily family, const Stmt *s) {
+    return RefState(Relinquished, s, family);
+  }
+  static RefState getEscaped(const RefState *RS) {
+    return RefState(Escaped, RS->getStmt(), RS->getAllocationFamily());
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    ID.AddInteger(K);
+    ID.AddPointer(S);
+    ID.AddInteger(Family);
+  }
+
+  LLVM_DUMP_METHOD void dump(raw_ostream &OS) const {
+    switch (K) {
+#define CASE(ID) case ID: OS << #ID; break;
+    CASE(Allocated)
+    CASE(AllocatedOfSizeZero)
+    CASE(Released)
+    CASE(Relinquished)
+    CASE(Escaped)
+    }
+  }
+
+  LLVM_DUMP_METHOD void dump() const { dump(llvm::errs()); }
+};
+
+} // end of anonymous namespace
+
+REGISTER_MAP_WITH_PROGRAMSTATE(RegionState, SymbolRef, RefState)
+
+/// Check if the memory associated with this symbol was released.
+static bool isReleased(SymbolRef Sym, CheckerContext &C);
+
+/// Update the RefState to reflect the new memory allocation.
+/// The optional \p RetVal parameter specifies the newly allocated pointer
+/// value; if unspecified, the value of expression \p E is used.
+static ProgramStateRef MallocUpdateRefState(CheckerContext &C, const Expr *E,
+                                            ProgramStateRef State,
+                                            AllocationFamily Family = AF_Malloc,
+                                            Optional<SVal> RetVal = None);
+
+//===----------------------------------------------------------------------===//
+// The modeling of memory reallocation.
+//
+// The terminology 'toPtr' and 'fromPtr' will be used:
+//   toPtr = realloc(fromPtr, 20);
+//===----------------------------------------------------------------------===//
+
+REGISTER_SET_WITH_PROGRAMSTATE(ReallocSizeZeroSymbols, SymbolRef)
+
+namespace {
+
+/// The state of 'fromPtr' after reallocation is known to have failed.
+enum OwnershipAfterReallocKind {
+  // The symbol needs to be freed (e.g.: realloc)
+  OAR_ToBeFreedAfterFailure,
+  // The symbol has been freed (e.g.: reallocf)
+  OAR_FreeOnFailure,
+  // The symbol doesn't have to freed (e.g.: we aren't sure if, how and where
+  // 'fromPtr' was allocated:
+  //    void Haha(int *ptr) {
+  //      ptr = realloc(ptr, 67);
+  //      // ...
+  //    }
+  // ).
+  OAR_DoNotTrackAfterFailure
+};
+
+/// Stores information about the 'fromPtr' symbol after reallocation.
+///
+/// This is important because realloc may fail, and that needs special modeling.
+/// Whether reallocation failed or not will not be known until later, so we'll
+/// store whether upon failure 'fromPtr' will be freed, or needs to be freed
+/// later, etc.
+struct ReallocPair {
+
+  // The 'fromPtr'.
+  SymbolRef ReallocatedSym;
+  OwnershipAfterReallocKind Kind;
+
+  ReallocPair(SymbolRef S, OwnershipAfterReallocKind K)
+      : ReallocatedSym(S), Kind(K) {}
+  void Profile(llvm::FoldingSetNodeID &ID) const {
+    ID.AddInteger(Kind);
+    ID.AddPointer(ReallocatedSym);
+  }
+  bool operator==(const ReallocPair &X) const {
+    return ReallocatedSym == X.ReallocatedSym &&
+           Kind == X.Kind;
+  }
+};
+
+} // end of anonymous namespace
+
+REGISTER_MAP_WITH_PROGRAMSTATE(ReallocPairs, SymbolRef, ReallocPair)
+
+//===----------------------------------------------------------------------===//
+// Kinds of memory operations, information about resource managing functions.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+enum class MemoryOperationKind { MOK_Allocate, MOK_Free, MOK_Any };
+
+struct MemFunctionInfoTy {
+  /// The value of the MallocChecker:Optimistic is stored in this variable.
+  ///
+  /// In pessimistic mode, the checker assumes that it does not know which
+  /// functions might free the memory.
+  /// In optimistic mode, the checker assumes that all user-defined functions
+  /// which might free a pointer are annotated.
+  DefaultBool ShouldIncludeOwnershipAnnotatedFunctions;
+
+  // TODO: Change these to CallDescription, and get rid of lazy initialization.
+  mutable IdentifierInfo *II_alloca = nullptr, *II_win_alloca = nullptr,
+                         *II_malloc = nullptr, *II_free = nullptr,
+                         *II_realloc = nullptr, *II_calloc = nullptr,
+                         *II_valloc = nullptr, *II_reallocf = nullptr,
+                         *II_strndup = nullptr, *II_strdup = nullptr,
+                         *II_win_strdup = nullptr, *II_kmalloc = nullptr,
+                         *II_if_nameindex = nullptr,
+                         *II_if_freenameindex = nullptr, *II_wcsdup = nullptr,
+                         *II_win_wcsdup = nullptr, *II_g_malloc = nullptr,
+                         *II_g_malloc0 = nullptr, *II_g_realloc = nullptr,
+                         *II_g_try_malloc = nullptr,
+                         *II_g_try_malloc0 = nullptr,
+                         *II_g_try_realloc = nullptr, *II_g_free = nullptr,
+                         *II_g_memdup = nullptr, *II_g_malloc_n = nullptr,
+                         *II_g_malloc0_n = nullptr, *II_g_realloc_n = nullptr,
+                         *II_g_try_malloc_n = nullptr,
+                         *II_g_try_malloc0_n = nullptr, *II_kfree = nullptr,
+                         *II_g_try_realloc_n = nullptr;
+
+  void initIdentifierInfo(ASTContext &C) const;
+
+  ///@{
+  /// Check if this is one of the functions which can allocate/reallocate
+  /// memory pointed to by one of its arguments.
+  bool isMemFunction(const FunctionDecl *FD, ASTContext &C) const;
+  bool isCMemFunction(const FunctionDecl *FD, ASTContext &C,
+                      AllocationFamily Family,
+                      MemoryOperationKind MemKind) const;
+
+  /// Tells if the callee is one of the builtin new/delete operators, including
+  /// placement operators and other standard overloads.
+  bool isStandardNewDelete(const FunctionDecl *FD, ASTContext &C) const;
+  ///@}
+};
+
+} // end of anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Definition of the MallocChecker class.
+//===----------------------------------------------------------------------===//
+
+namespace {
+
+class MallocChecker
+    : public Checker<check::DeadSymbols, check::PointerEscape,
+                     check::ConstPointerEscape, check::PreStmt<ReturnStmt>,
+                     check::EndFunction, check::PreCall,
+                     check::PostStmt<CallExpr>, check::PostStmt<CXXNewExpr>,
+                     check::NewAllocator, check::PreStmt<CXXDeleteExpr>,
+                     check::PostStmt<BlockExpr>, check::PostObjCMessage,
+                     check::Location, eval::Assume> {
+public:
+  MemFunctionInfoTy MemFunctionInfo;
+
+  /// Many checkers are essentially built into this one, so enabling them will
+  /// make MallocChecker perform additional modeling and reporting.
+  enum CheckKind {
+    /// When a subchecker is enabled but MallocChecker isn't, model memory
+    /// management but do not emit warnings emitted with MallocChecker only
+    /// enabled.
+    CK_MallocChecker,
+    CK_NewDeleteChecker,
+    CK_NewDeleteLeaksChecker,
+    CK_MismatchedDeallocatorChecker,
+    CK_InnerPointerChecker,
+    CK_NumCheckKinds
+  };
+
+  using LeakInfo = std::pair<const ExplodedNode *, const MemRegion *>;
+
+  DefaultBool ChecksEnabled[CK_NumCheckKinds];
+  CheckerNameRef CheckNames[CK_NumCheckKinds];
+
+  void checkPreCall(const CallEvent &Call, CheckerContext &C) const;
+  void checkPostStmt(const CallExpr *CE, CheckerContext &C) const;
+  void checkPostStmt(const CXXNewExpr *NE, CheckerContext &C) const;
+  void checkNewAllocator(const CXXNewExpr *NE, SVal Target,
+                         CheckerContext &C) const;
+  void checkPreStmt(const CXXDeleteExpr *DE, CheckerContext &C) const;
+  void checkPostObjCMessage(const ObjCMethodCall &Call, CheckerContext &C) const;
+  void checkPostStmt(const BlockExpr *BE, CheckerContext &C) const;
+  void checkDeadSymbols(SymbolReaper &SymReaper, CheckerContext &C) const;
+  void checkPreStmt(const ReturnStmt *S, CheckerContext &C) const;
+  void checkEndFunction(const ReturnStmt *S, CheckerContext &C) const;
+  ProgramStateRef evalAssume(ProgramStateRef state, SVal Cond,
+                            bool Assumption) const;
+  void checkLocation(SVal l, bool isLoad, const Stmt *S,
+                     CheckerContext &C) const;
+
+  ProgramStateRef checkPointerEscape(ProgramStateRef State,
+                                    const InvalidatedSymbols &Escaped,
+                                    const CallEvent *Call,
+                                    PointerEscapeKind Kind) const;
+  ProgramStateRef checkConstPointerEscape(ProgramStateRef State,
+                                          const InvalidatedSymbols &Escaped,
+                                          const CallEvent *Call,
+                                          PointerEscapeKind Kind) const;
+
+  void printState(raw_ostream &Out, ProgramStateRef State,
+                  const char *NL, const char *Sep) const override;
+
+private:
+  mutable std::unique_ptr<BugType> BT_DoubleFree[CK_NumCheckKinds];
+  mutable std::unique_ptr<BugType> BT_DoubleDelete;
+  mutable std::unique_ptr<BugType> BT_Leak[CK_NumCheckKinds];
+  mutable std::unique_ptr<BugType> BT_UseFree[CK_NumCheckKinds];
+  mutable std::unique_ptr<BugType> BT_BadFree[CK_NumCheckKinds];
+  mutable std::unique_ptr<BugType> BT_FreeAlloca[CK_NumCheckKinds];
+  mutable std::unique_ptr<BugType> BT_MismatchedDealloc;
+  mutable std::unique_ptr<BugType> BT_OffsetFree[CK_NumCheckKinds];
+  mutable std::unique_ptr<BugType> BT_UseZerroAllocated[CK_NumCheckKinds];
+
+  // TODO: Remove mutable by moving the initializtaion to the registry function.
+  mutable Optional<uint64_t> KernelZeroFlagVal;
+
+  /// Process C++ operator new()'s allocation, which is the part of C++
+  /// new-expression that goes before the constructor.
+  void processNewAllocation(const CXXNewExpr *NE, CheckerContext &C,
+                            SVal Target) const;
+
+  /// Perform a zero-allocation check.
+  ///
+  /// \param [in] E The expression that allocates memory.
+  /// \param [in] IndexOfSizeArg Index of the argument that specifies the size
+  ///   of the memory that needs to be allocated. E.g. for malloc, this would be
+  ///   0.
+  /// \param [in] RetVal Specifies the newly allocated pointer value;
+  ///   if unspecified, the value of expression \p E is used.
+  static ProgramStateRef ProcessZeroAllocCheck(CheckerContext &C, const Expr *E,
+                                               const unsigned IndexOfSizeArg,
+                                               ProgramStateRef State,
+                                               Optional<SVal> RetVal = None);
+
+  /// Model functions with the ownership_returns attribute.
+  ///
+  /// User-defined function may have the ownership_returns attribute, which
+  /// annotates that the function returns with an object that was allocated on
+  /// the heap, and passes the ownertship to the callee.
+  ///
+  ///   void __attribute((ownership_returns(malloc, 1))) *my_malloc(size_t);
+  ///
+  /// It has two parameters:
+  ///   - first: name of the resource (e.g. 'malloc')
+  ///   - (OPTIONAL) second: size of the allocated region
+  ///
+  /// \param [in] CE The expression that allocates memory.
+  /// \param [in] Att The ownership_returns attribute.
+  /// \param [in] State The \c ProgramState right before allocation.
+  /// \returns The ProgramState right after allocation.
+  ProgramStateRef MallocMemReturnsAttr(CheckerContext &C,
+                                       const CallExpr *CE,
+                                       const OwnershipAttr* Att,
+                                       ProgramStateRef State) const;
+
+  /// Models memory allocation.
+  ///
+  /// \param [in] CE The expression that allocates memory.
+  /// \param [in] SizeEx Size of the memory that needs to be allocated.
+  /// \param [in] Init The value the allocated memory needs to be initialized.
+  /// with. For example, \c calloc initializes the allocated memory to 0,
+  /// malloc leaves it undefined.
+  /// \param [in] State The \c ProgramState right before allocation.
+  /// \returns The ProgramState right after allocation.
+  static ProgramStateRef MallocMemAux(CheckerContext &C, const CallExpr *CE,
+                                      const Expr *SizeEx, SVal Init,
+                                      ProgramStateRef State,
+                                      AllocationFamily Family = AF_Malloc);
+
+  /// Models memory allocation.
+  ///
+  /// \param [in] CE The expression that allocates memory.
+  /// \param [in] Size Size of the memory that needs to be allocated.
+  /// \param [in] Init The value the allocated memory needs to be initialized.
+  /// with. For example, \c calloc initializes the allocated memory to 0,
+  /// malloc leaves it undefined.
+  /// \param [in] State The \c ProgramState right before allocation.
+  /// \returns The ProgramState right after allocation.
+  static ProgramStateRef MallocMemAux(CheckerContext &C, const CallExpr *CE,
+                                      SVal Size, SVal Init,
+                                      ProgramStateRef State,
+                                      AllocationFamily Family = AF_Malloc);
+
+  static ProgramStateRef addExtentSize(CheckerContext &C, const CXXNewExpr *NE,
+                                       ProgramStateRef State, SVal Target);
+
+  // Check if this malloc() for special flags. At present that means M_ZERO or
+  // __GFP_ZERO (in which case, treat it like calloc).
+  llvm::Optional<ProgramStateRef>
+  performKernelMalloc(const CallExpr *CE, CheckerContext &C,
+                      const ProgramStateRef &State) const;
+
+  /// Model functions with the ownership_takes and ownership_holds attributes.
+  ///
+  /// User-defined function may have the ownership_takes and/or ownership_holds
+  /// attributes, which annotates that the function frees the memory passed as a
+  /// parameter.
+  ///
+  ///   void __attribute((ownership_takes(malloc, 1))) my_free(void *);
+  ///   void __attribute((ownership_holds(malloc, 1))) my_hold(void *);
+  ///
+  /// They have two parameters:
+  ///   - first: name of the resource (e.g. 'malloc')
+  ///   - second: index of the parameter the attribute applies to
+  ///
+  /// \param [in] CE The expression that frees memory.
+  /// \param [in] Att The ownership_takes or ownership_holds attribute.
+  /// \param [in] State The \c ProgramState right before allocation.
+  /// \returns The ProgramState right after deallocation.
+  ProgramStateRef FreeMemAttr(CheckerContext &C, const CallExpr *CE,
+                              const OwnershipAttr* Att,
+                              ProgramStateRef State) const;
+
+  /// Models memory deallocation.
+  ///
+  /// \param [in] CE The expression that frees memory.
+  /// \param [in] State The \c ProgramState right before allocation.
+  /// \param [in] Num Index of the argument that needs to be freed. This is
+  ///   normally 0, but for custom free functions it may be different.
+  /// \param [in] Hold Whether the parameter at \p Index has the ownership_holds
+  ///   attribute.
+  /// \param [out] IsKnownToBeAllocated Whether the memory to be freed is known
+  ///   to have been allocated, or in other words, the symbol to be freed was
+  ///   registered as allocated by this checker. In the following case, \c ptr
+  ///   isn't known to be allocated.
+  ///      void Haha(int *ptr) {
+  ///        ptr = realloc(ptr, 67);
+  ///        // ...
+  ///      }
+  /// \param [in] ReturnsNullOnFailure Whether the memory deallocation function
+  ///   we're modeling returns with Null on failure.
+  /// \returns The ProgramState right after deallocation.
+  ProgramStateRef FreeMemAux(CheckerContext &C, const CallExpr *CE,
+                             ProgramStateRef State, unsigned Num, bool Hold,
+                             bool &IsKnownToBeAllocated,
+                             bool ReturnsNullOnFailure = false) const;
+
+  /// Models memory deallocation.
+  ///
+  /// \param [in] ArgExpr The variable who's pointee needs to be freed.
+  /// \param [in] ParentExpr The expression that frees the memory.
+  /// \param [in] State The \c ProgramState right before allocation.
+  ///   normally 0, but for custom free functions it may be different.
+  /// \param [in] Hold Whether the parameter at \p Index has the ownership_holds
+  ///   attribute.
+  /// \param [out] IsKnownToBeAllocated Whether the memory to be freed is known
+  ///   to have been allocated, or in other words, the symbol to be freed was
+  ///   registered as allocated by this checker. In the following case, \c ptr
+  ///   isn't known to be allocated.
+  ///      void Haha(int *ptr) {
+  ///        ptr = realloc(ptr, 67);
+  ///        // ...
+  ///      }
+  /// \param [in] ReturnsNullOnFailure Whether the memory deallocation function
+  ///   we're modeling returns with Null on failure.
+  /// \returns The ProgramState right after deallocation.
+  ProgramStateRef FreeMemAux(CheckerContext &C, const Expr *ArgExpr,
+                             const Expr *ParentExpr, ProgramStateRef State,
+                             bool Hold, bool &IsKnownToBeAllocated,
+                             bool ReturnsNullOnFailure = false) const;
+
+  // TODO: Needs some refactoring, as all other deallocation modeling
+  // functions are suffering from out parameters and messy code due to how
+  // realloc is handled.
+  //
+  /// Models memory reallocation.
+  ///
+  /// \param [in] CE The expression that reallocated memory
+  /// \param [in] ShouldFreeOnFail Whether if reallocation fails, the supplied
+  ///   memory should be freed.
+  /// \param [in] State The \c ProgramState right before reallocation.
+  /// \param [in] SuffixWithN Whether the reallocation function we're modeling
+  ///   has an '_n' suffix, such as g_realloc_n.
+  /// \returns The ProgramState right after reallocation.
+  ProgramStateRef ReallocMemAux(CheckerContext &C, const CallExpr *CE,
+                                bool ShouldFreeOnFail, ProgramStateRef State,
+                                bool SuffixWithN = false) const;
+
+  /// Evaluates the buffer size that needs to be allocated.
+  ///
+  /// \param [in] Blocks The amount of blocks that needs to be allocated.
+  /// \param [in] BlockBytes The size of a block.
+  /// \returns The symbolic value of \p Blocks * \p BlockBytes.
+  static SVal evalMulForBufferSize(CheckerContext &C, const Expr *Blocks,
+                                   const Expr *BlockBytes);
+
+  /// Models zero initialized array allocation.
+  ///
+  /// \param [in] CE The expression that reallocated memory
+  /// \param [in] State The \c ProgramState right before reallocation.
+  /// \returns The ProgramState right after allocation.
+  static ProgramStateRef CallocMem(CheckerContext &C, const CallExpr *CE,
+                                   ProgramStateRef State);
+
+  /// See if deallocation happens in a suspicious context. If so, escape the
+  /// pointers that otherwise would have been deallocated and return true.
+  bool suppressDeallocationsInSuspiciousContexts(const CallExpr *CE,
+                                                 CheckerContext &C) const;
+
+  /// If in \p S  \p Sym is used, check whether \p Sym was already freed.
+  bool checkUseAfterFree(SymbolRef Sym, CheckerContext &C, const Stmt *S) const;
+
+  /// If in \p S \p Sym is used, check whether \p Sym was allocated as a zero
+  /// sized memory region.
+  void checkUseZeroAllocated(SymbolRef Sym, CheckerContext &C,
+                             const Stmt *S) const;
+
+  /// If in \p S \p Sym is being freed, check whether \p Sym was already freed.
+  bool checkDoubleDelete(SymbolRef Sym, CheckerContext &C) const;
+
+  /// Check if the function is known to free memory, or if it is
+  /// "interesting" and should be modeled explicitly.
+  ///
+  /// \param [out] EscapingSymbol A function might not free memory in general,
+  ///   but could be known to free a particular symbol. In this case, false is
+  ///   returned and the single escaping symbol is returned through the out
+  ///   parameter.
+  ///
+  /// We assume that pointers do not escape through calls to system functions
+  /// not handled by this checker.
+  bool mayFreeAnyEscapedMemoryOrIsModeledExplicitly(const CallEvent *Call,
+                                   ProgramStateRef State,
+                                   SymbolRef &EscapingSymbol) const;
+
+  /// Implementation of the checkPointerEscape callbacks.
+  ProgramStateRef checkPointerEscapeAux(ProgramStateRef State,
+                                        const InvalidatedSymbols &Escaped,
+                                        const CallEvent *Call,
+                                        PointerEscapeKind Kind,
+                                        bool IsConstPointerEscape) const;
+
+  // Implementation of the checkPreStmt and checkEndFunction callbacks.
+  void checkEscapeOnReturn(const ReturnStmt *S, CheckerContext &C) const;
+
+  ///@{
+  /// Tells if a given family/call/symbol is tracked by the current checker.
+  /// Sets CheckKind to the kind of the checker responsible for this
+  /// family/call/symbol.
+  Optional<CheckKind> getCheckIfTracked(AllocationFamily Family,
+                                        bool IsALeakCheck = false) const;
+  Optional<CheckKind> getCheckIfTracked(CheckerContext &C,
+                                        const Stmt *AllocDeallocStmt,
+                                        bool IsALeakCheck = false) const;
+  Optional<CheckKind> getCheckIfTracked(CheckerContext &C, SymbolRef Sym,
+                                        bool IsALeakCheck = false) const;
+  ///@}
+  static bool SummarizeValue(raw_ostream &os, SVal V);
+  static bool SummarizeRegion(raw_ostream &os, const MemRegion *MR);
+
+  void ReportBadFree(CheckerContext &C, SVal ArgVal, SourceRange Range,
+                     const Expr *DeallocExpr) const;
+  void ReportFreeAlloca(CheckerContext &C, SVal ArgVal,
+                        SourceRange Range) const;
+  void ReportMismatchedDealloc(CheckerContext &C, SourceRange Range,
+                               const Expr *DeallocExpr, const RefState *RS,
+                               SymbolRef Sym, bool OwnershipTransferred) const;
+  void ReportOffsetFree(CheckerContext &C, SVal ArgVal, SourceRange Range,
+                        const Expr *DeallocExpr,
+                        const Expr *AllocExpr = nullptr) const;
+  void ReportUseAfterFree(CheckerContext &C, SourceRange Range,
+                          SymbolRef Sym) const;
+  void ReportDoubleFree(CheckerContext &C, SourceRange Range, bool Released,
+                        SymbolRef Sym, SymbolRef PrevSym) const;
+
+  void ReportDoubleDelete(CheckerContext &C, SymbolRef Sym) const;
+
+  void ReportUseZeroAllocated(CheckerContext &C, SourceRange Range,
+                              SymbolRef Sym) const;
+
+  void ReportFunctionPointerFree(CheckerContext &C, SVal ArgVal,
+                                 SourceRange Range, const Expr *FreeExpr) const;
+
+  /// Find the location of the allocation for Sym on the path leading to the
+  /// exploded node N.
+  static LeakInfo getAllocationSite(const ExplodedNode *N, SymbolRef Sym,
+                                    CheckerContext &C);
+
+  void reportLeak(SymbolRef Sym, ExplodedNode *N, CheckerContext &C) const;
+};
+
+//===----------------------------------------------------------------------===//
+// Definition of MallocBugVisitor.
+//===----------------------------------------------------------------------===//
+
+/// The bug visitor which allows us to print extra diagnostics along the
+/// BugReport path. For example, showing the allocation site of the leaked
+/// region.
+class MallocBugVisitor final : public BugReporterVisitor {
+protected:
+  enum NotificationMode { Normal, ReallocationFailed };
+
+  // The allocated region symbol tracked by the main analysis.
+  SymbolRef Sym;
+
+  // The mode we are in, i.e. what kind of diagnostics will be emitted.
+  NotificationMode Mode;
+
+  // A symbol from when the primary region should have been reallocated.
+  SymbolRef FailedReallocSymbol;
+
+  // A C++ destructor stack frame in which memory was released. Used for
+  // miscellaneous false positive suppression.
+  const StackFrameContext *ReleaseDestructorLC;
+
+  bool IsLeak;
+
+public:
+  MallocBugVisitor(SymbolRef S, bool isLeak = false)
+      : Sym(S), Mode(Normal), FailedReallocSymbol(nullptr),
+        ReleaseDestructorLC(nullptr), IsLeak(isLeak) {}
+
+  static void *getTag() {
+    static int Tag = 0;
+    return &Tag;
+  }
+
+  void Profile(llvm::FoldingSetNodeID &ID) const override {
+    ID.AddPointer(getTag());
+    ID.AddPointer(Sym);
+  }
+
+  /// Did not track -> allocated. Other state (released) -> allocated.
+  static inline bool isAllocated(const RefState *RSCurr, const RefState *RSPrev,
+                                 const Stmt *Stmt) {
+    return (Stmt && (isa<CallExpr>(Stmt) || isa<CXXNewExpr>(Stmt)) &&
+            (RSCurr &&
+             (RSCurr->isAllocated() || RSCurr->isAllocatedOfSizeZero())) &&
+            (!RSPrev ||
+             !(RSPrev->isAllocated() || RSPrev->isAllocatedOfSizeZero())));
+  }
+
+  /// Did not track -> released. Other state (allocated) -> released.
+  /// The statement associated with the release might be missing.
+  static inline bool isReleased(const RefState *RSCurr, const RefState *RSPrev,
+                                const Stmt *Stmt) {
+    bool IsReleased =
+        (RSCurr && RSCurr->isReleased()) && (!RSPrev || !RSPrev->isReleased());
+    assert(!IsReleased ||
+           (Stmt && (isa<CallExpr>(Stmt) || isa<CXXDeleteExpr>(Stmt))) ||
+           (!Stmt && RSCurr->getAllocationFamily() == AF_InnerBuffer));
+    return IsReleased;
+  }
+
+  /// Did not track -> relinquished. Other state (allocated) -> relinquished.
+  static inline bool isRelinquished(const RefState *RSCurr,
+                                    const RefState *RSPrev, const Stmt *Stmt) {
+    return (Stmt &&
+            (isa<CallExpr>(Stmt) || isa<ObjCMessageExpr>(Stmt) ||
+             isa<ObjCPropertyRefExpr>(Stmt)) &&
+            (RSCurr && RSCurr->isRelinquished()) &&
+            (!RSPrev || !RSPrev->isRelinquished()));
+  }
+
+  /// If the expression is not a call, and the state change is
+  /// released -> allocated, it must be the realloc return value
+  /// check. If we have to handle more cases here, it might be cleaner just
+  /// to track this extra bit in the state itself.
+  static inline bool hasReallocFailed(const RefState *RSCurr,
+                                      const RefState *RSPrev,
+                                      const Stmt *Stmt) {
+    return ((!Stmt || !isa<CallExpr>(Stmt)) &&
+            (RSCurr &&
+             (RSCurr->isAllocated() || RSCurr->isAllocatedOfSizeZero())) &&
+            (RSPrev &&
+             !(RSPrev->isAllocated() || RSPrev->isAllocatedOfSizeZero())));
+  }
+
+  PathDiagnosticPieceRef VisitNode(const ExplodedNode *N,
+                                   BugReporterContext &BRC,
+                                   PathSensitiveBugReport &BR) override;
+
+  PathDiagnosticPieceRef getEndPath(BugReporterContext &BRC,
+                                    const ExplodedNode *EndPathNode,
+                                    PathSensitiveBugReport &BR) override {
+    if (!IsLeak)
+      return nullptr;
+
+    PathDiagnosticLocation L = BR.getLocation();
+    // Do not add the statement itself as a range in case of leak.
+    return std::make_shared<PathDiagnosticEventPiece>(L, BR.getDescription(),
+                                                      false);
+  }
+
+private:
+  class StackHintGeneratorForReallocationFailed
+      : public StackHintGeneratorForSymbol {
+  public:
+    StackHintGeneratorForReallocationFailed(SymbolRef S, StringRef M)
+        : StackHintGeneratorForSymbol(S, M) {}
+
+    std::string getMessageForArg(const Expr *ArgE, unsigned ArgIndex) override {
+      // Printed parameters start at 1, not 0.
+      ++ArgIndex;
+
+      SmallString<200> buf;
+      llvm::raw_svector_ostream os(buf);
+
+      os << "Reallocation of " << ArgIndex << llvm::getOrdinalSuffix(ArgIndex)
+         << " parameter failed";
+
+      return os.str();
+    }
+
+    std::string getMessageForReturn(const CallExpr *CallExpr) override {
+      return "Reallocation of returned value failed";
+    }
+  };
+};
+
+} // end anonymous namespace
+
+// A map from the freed symbol to the symbol representing the return value of
+// the free function.
+REGISTER_MAP_WITH_PROGRAMSTATE(FreeReturnValue, SymbolRef, SymbolRef)
+
+namespace {
+class StopTrackingCallback final : public SymbolVisitor {
+  ProgramStateRef state;
+public:
+  StopTrackingCallback(ProgramStateRef st) : state(std::move(st)) {}
+  ProgramStateRef getState() const { return state; }
+
+  bool VisitSymbol(SymbolRef sym) override {
+    state = state->remove<RegionState>(sym);
+    return true;
+  }
+};
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Methods of MemFunctionInfoTy.
+//===----------------------------------------------------------------------===//
+
+void MemFunctionInfoTy::initIdentifierInfo(ASTContext &Ctx) const {
+  if (II_malloc)
+    return;
+  II_alloca = &Ctx.Idents.get("alloca");
+  II_malloc = &Ctx.Idents.get("malloc");
+  II_free = &Ctx.Idents.get("free");
+  II_realloc = &Ctx.Idents.get("realloc");
+  II_reallocf = &Ctx.Idents.get("reallocf");
+  II_calloc = &Ctx.Idents.get("calloc");
+  II_valloc = &Ctx.Idents.get("valloc");
+  II_strdup = &Ctx.Idents.get("strdup");
+  II_strndup = &Ctx.Idents.get("strndup");
+  II_wcsdup = &Ctx.Idents.get("wcsdup");
+  II_kmalloc = &Ctx.Idents.get("kmalloc");
+  II_kfree = &Ctx.Idents.get("kfree");
+  II_if_nameindex = &Ctx.Idents.get("if_nameindex");
+  II_if_freenameindex = &Ctx.Idents.get("if_freenameindex");
+
+  //MSVC uses `_`-prefixed instead, so we check for them too.
+  II_win_strdup = &Ctx.Idents.get("_strdup");
+  II_win_wcsdup = &Ctx.Idents.get("_wcsdup");
+  II_win_alloca = &Ctx.Idents.get("_alloca");
+
+  // Glib
+  II_g_malloc = &Ctx.Idents.get("g_malloc");
+  II_g_malloc0 = &Ctx.Idents.get("g_malloc0");
+  II_g_realloc = &Ctx.Idents.get("g_realloc");
+  II_g_try_malloc = &Ctx.Idents.get("g_try_malloc");
+  II_g_try_malloc0 = &Ctx.Idents.get("g_try_malloc0");
+  II_g_try_realloc = &Ctx.Idents.get("g_try_realloc");
+  II_g_free = &Ctx.Idents.get("g_free");
+  II_g_memdup = &Ctx.Idents.get("g_memdup");
+  II_g_malloc_n = &Ctx.Idents.get("g_malloc_n");
+  II_g_malloc0_n = &Ctx.Idents.get("g_malloc0_n");
+  II_g_realloc_n = &Ctx.Idents.get("g_realloc_n");
+  II_g_try_malloc_n = &Ctx.Idents.get("g_try_malloc_n");
+  II_g_try_malloc0_n = &Ctx.Idents.get("g_try_malloc0_n");
+  II_g_try_realloc_n = &Ctx.Idents.get("g_try_realloc_n");
+}
+
+bool MemFunctionInfoTy::isMemFunction(const FunctionDecl *FD,
+                                      ASTContext &C) const {
+  if (isCMemFunction(FD, C, AF_Malloc, MemoryOperationKind::MOK_Any))
+    return true;
+
+  if (isCMemFunction(FD, C, AF_IfNameIndex, MemoryOperationKind::MOK_Any))
+    return true;
+
+  if (isCMemFunction(FD, C, AF_Alloca, MemoryOperationKind::MOK_Any))
+    return true;
+
+  if (isStandardNewDelete(FD, C))
+    return true;
+
+  return false;
+}
+
+bool MemFunctionInfoTy::isCMemFunction(const FunctionDecl *FD, ASTContext &C,
+                                       AllocationFamily Family,
+                                       MemoryOperationKind MemKind) const {
+  if (!FD)
+    return false;
+
+  bool CheckFree = (MemKind == MemoryOperationKind::MOK_Any ||
+                    MemKind == MemoryOperationKind::MOK_Free);
+  bool CheckAlloc = (MemKind == MemoryOperationKind::MOK_Any ||
+                     MemKind == MemoryOperationKind::MOK_Allocate);
+
+  if (FD->getKind() == Decl::Function) {
+    const IdentifierInfo *FunI = FD->getIdentifier();
+    initIdentifierInfo(C);
+
+    if (Family == AF_Malloc && CheckFree) {
+      if (FunI == II_free || FunI == II_realloc || FunI == II_reallocf ||
+          FunI == II_g_free || FunI == II_kfree)
+        return true;
+    }
+
+    if (Family == AF_Malloc && CheckAlloc) {
+      if (FunI == II_malloc || FunI == II_realloc || FunI == II_reallocf ||
+          FunI == II_calloc || FunI == II_valloc || FunI == II_strdup ||
+          FunI == II_win_strdup || FunI == II_strndup || FunI == II_wcsdup ||
+          FunI == II_win_wcsdup || FunI == II_kmalloc ||
+          FunI == II_g_malloc || FunI == II_g_malloc0 ||
+          FunI == II_g_realloc || FunI == II_g_try_malloc ||
+          FunI == II_g_try_malloc0 || FunI == II_g_try_realloc ||
+          FunI == II_g_memdup || FunI == II_g_malloc_n ||
+          FunI == II_g_malloc0_n || FunI == II_g_realloc_n ||
+          FunI == II_g_try_malloc_n || FunI == II_g_try_malloc0_n ||
+          FunI == II_g_try_realloc_n)
+        return true;
+    }
+
+    if (Family == AF_IfNameIndex && CheckFree) {
+      if (FunI == II_if_freenameindex)
+        return true;
+    }
+
+    if (Family == AF_IfNameIndex && CheckAlloc) {
+      if (FunI == II_if_nameindex)
+        return true;
+    }
+
+    if (Family == AF_Alloca && CheckAlloc) {
+      if (FunI == II_alloca || FunI == II_win_alloca)
+        return true;
+    }
+  }
+
+  if (Family != AF_Malloc)
+    return false;
+
+  if (ShouldIncludeOwnershipAnnotatedFunctions && FD->hasAttrs()) {
+    for (const auto *I : FD->specific_attrs<OwnershipAttr>()) {
+      OwnershipAttr::OwnershipKind OwnKind = I->getOwnKind();
+      if(OwnKind == OwnershipAttr::Takes || OwnKind == OwnershipAttr::Holds) {
+        if (CheckFree)
+          return true;
+      } else if (OwnKind == OwnershipAttr::Returns) {
+        if (CheckAlloc)
+          return true;
+      }
+    }
+  }
+
+  return false;
+}
+bool MemFunctionInfoTy::isStandardNewDelete(const FunctionDecl *FD,
+                                            ASTContext &C) const {
+  if (!FD)
+    return false;
+
+  OverloadedOperatorKind Kind = FD->getOverloadedOperator();
+  if (Kind != OO_New && Kind != OO_Array_New &&
+      Kind != OO_Delete && Kind != OO_Array_Delete)
+    return false;
+
+  // This is standard if and only if it's not defined in a user file.
+  SourceLocation L = FD->getLocation();
+  // If the header for operator delete is not included, it's still defined
+  // in an invalid source location. Check to make sure we don't crash.
+  return !L.isValid() || C.getSourceManager().isInSystemHeader(L);
+}
+
+//===----------------------------------------------------------------------===//
+// Methods of MallocChecker and MallocBugVisitor.
+//===----------------------------------------------------------------------===//
+
+llvm::Optional<ProgramStateRef> MallocChecker::performKernelMalloc(
+  const CallExpr *CE, CheckerContext &C, const ProgramStateRef &State) const {
+  // 3-argument malloc(), as commonly used in {Free,Net,Open}BSD Kernels:
+  //
+  // void *malloc(unsigned long size, struct malloc_type *mtp, int flags);
+  //
+  // One of the possible flags is M_ZERO, which means 'give me back an
+  // allocation which is already zeroed', like calloc.
+
+  // 2-argument kmalloc(), as used in the Linux kernel:
+  //
+  // void *kmalloc(size_t size, gfp_t flags);
+  //
+  // Has the similar flag value __GFP_ZERO.
+
+  // This logic is largely cloned from O_CREAT in UnixAPIChecker, maybe some
+  // code could be shared.
+
+  ASTContext &Ctx = C.getASTContext();
+  llvm::Triple::OSType OS = Ctx.getTargetInfo().getTriple().getOS();
+
+  if (!KernelZeroFlagVal.hasValue()) {
+    if (OS == llvm::Triple::FreeBSD)
+      KernelZeroFlagVal = 0x0100;
+    else if (OS == llvm::Triple::NetBSD)
+      KernelZeroFlagVal = 0x0002;
+    else if (OS == llvm::Triple::OpenBSD)
+      KernelZeroFlagVal = 0x0008;
+    else if (OS == llvm::Triple::Linux)
+      // __GFP_ZERO
+      KernelZeroFlagVal = 0x8000;
+    else
+      // FIXME: We need a more general way of getting the M_ZERO value.
+      // See also: O_CREAT in UnixAPIChecker.cpp.
+
+      // Fall back to normal malloc behavior on platforms where we don't
+      // know M_ZERO.
+      return None;
+  }
+
+  // We treat the last argument as the flags argument, and callers fall-back to
+  // normal malloc on a None return. This works for the FreeBSD kernel malloc
+  // as well as Linux kmalloc.
+  if (CE->getNumArgs() < 2)
+    return None;
+
+  const Expr *FlagsEx = CE->getArg(CE->getNumArgs() - 1);
+  const SVal V = C.getSVal(FlagsEx);
+  if (!V.getAs<NonLoc>()) {
+    // The case where 'V' can be a location can only be due to a bad header,
+    // so in this case bail out.
+    return None;
+  }
+
+  NonLoc Flags = V.castAs<NonLoc>();
+  NonLoc ZeroFlag = C.getSValBuilder()
+      .makeIntVal(KernelZeroFlagVal.getValue(), FlagsEx->getType())
+      .castAs<NonLoc>();
+  SVal MaskedFlagsUC = C.getSValBuilder().evalBinOpNN(State, BO_And,
+                                                      Flags, ZeroFlag,
+                                                      FlagsEx->getType());
+  if (MaskedFlagsUC.isUnknownOrUndef())
+    return None;
+  DefinedSVal MaskedFlags = MaskedFlagsUC.castAs<DefinedSVal>();
+
+  // Check if maskedFlags is non-zero.
+  ProgramStateRef TrueState, FalseState;
+  std::tie(TrueState, FalseState) = State->assume(MaskedFlags);
+
+  // If M_ZERO is set, treat this like calloc (initialized).
+  if (TrueState && !FalseState) {
+    SVal ZeroVal = C.getSValBuilder().makeZeroVal(Ctx.CharTy);
+    return MallocMemAux(C, CE, CE->getArg(0), ZeroVal, TrueState);
+  }
+
+  return None;
+}
+
+SVal MallocChecker::evalMulForBufferSize(CheckerContext &C, const Expr *Blocks,
+                                         const Expr *BlockBytes) {
+  SValBuilder &SB = C.getSValBuilder();
+  SVal BlocksVal = C.getSVal(Blocks);
+  SVal BlockBytesVal = C.getSVal(BlockBytes);
+  ProgramStateRef State = C.getState();
+  SVal TotalSize = SB.evalBinOp(State, BO_Mul, BlocksVal, BlockBytesVal,
+                                SB.getContext().getSizeType());
+  return TotalSize;
+}
+
+void MallocChecker::checkPostStmt(const CallExpr *CE, CheckerContext &C) const {
+  if (C.wasInlined)
+    return;
+
+  const FunctionDecl *FD = C.getCalleeDecl(CE);
+  if (!FD)
+    return;
+
+  ProgramStateRef State = C.getState();
+  bool IsKnownToBeAllocatedMemory = false;
+
+  if (FD->getKind() == Decl::Function) {
+    MemFunctionInfo.initIdentifierInfo(C.getASTContext());
+    IdentifierInfo *FunI = FD->getIdentifier();
+
+    if (FunI == MemFunctionInfo.II_malloc ||
+        FunI == MemFunctionInfo.II_g_malloc ||
+        FunI == MemFunctionInfo.II_g_try_malloc) {
+      switch (CE->getNumArgs()) {
+      default:
+        return;
+      case 1:
+        State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State);
+        State = ProcessZeroAllocCheck(C, CE, 0, State);
+        break;
+      case 2:
+        State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State);
+        break;
+      case 3:
+        llvm::Optional<ProgramStateRef> MaybeState =
+          performKernelMalloc(CE, C, State);
+        if (MaybeState.hasValue())
+          State = MaybeState.getValue();
+        else
+          State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State);
+        break;
+      }
+    } else if (FunI == MemFunctionInfo.II_kmalloc) {
+      if (CE->getNumArgs() < 1)
+        return;
+      llvm::Optional<ProgramStateRef> MaybeState =
+        performKernelMalloc(CE, C, State);
+      if (MaybeState.hasValue())
+        State = MaybeState.getValue();
+      else
+        State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State);
+    } else if (FunI == MemFunctionInfo.II_valloc) {
+      if (CE->getNumArgs() < 1)
+        return;
+      State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State);
+      State = ProcessZeroAllocCheck(C, CE, 0, State);
+    } else if (FunI == MemFunctionInfo.II_realloc ||
+               FunI == MemFunctionInfo.II_g_realloc ||
+               FunI == MemFunctionInfo.II_g_try_realloc) {
+      State = ReallocMemAux(C, CE, /*ShouldFreeOnFail*/ false, State);
+      State = ProcessZeroAllocCheck(C, CE, 1, State);
+    } else if (FunI == MemFunctionInfo.II_reallocf) {
+      State = ReallocMemAux(C, CE, /*ShouldFreeOnFail*/ true, State);
+      State = ProcessZeroAllocCheck(C, CE, 1, State);
+    } else if (FunI == MemFunctionInfo.II_calloc) {
+      State = CallocMem(C, CE, State);
+      State = ProcessZeroAllocCheck(C, CE, 0, State);
+      State = ProcessZeroAllocCheck(C, CE, 1, State);
+    } else if (FunI == MemFunctionInfo.II_free ||
+               FunI == MemFunctionInfo.II_g_free ||
+               FunI == MemFunctionInfo.II_kfree) {
+      if (suppressDeallocationsInSuspiciousContexts(CE, C))
+        return;
+
+      State = FreeMemAux(C, CE, State, 0, false, IsKnownToBeAllocatedMemory);
+    } else if (FunI == MemFunctionInfo.II_strdup ||
+               FunI == MemFunctionInfo.II_win_strdup ||
+               FunI == MemFunctionInfo.II_wcsdup ||
+               FunI == MemFunctionInfo.II_win_wcsdup) {
+      State = MallocUpdateRefState(C, CE, State);
+    } else if (FunI == MemFunctionInfo.II_strndup) {
+      State = MallocUpdateRefState(C, CE, State);
+    } else if (FunI == MemFunctionInfo.II_alloca ||
+               FunI == MemFunctionInfo.II_win_alloca) {
+      if (CE->getNumArgs() < 1)
+        return;
+      State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State,
+                           AF_Alloca);
+      State = ProcessZeroAllocCheck(C, CE, 0, State);
+    } else if (MemFunctionInfo.isStandardNewDelete(FD, C.getASTContext())) {
+      // Process direct calls to operator new/new[]/delete/delete[] functions
+      // as distinct from new/new[]/delete/delete[] expressions that are
+      // processed by the checkPostStmt callbacks for CXXNewExpr and
+      // CXXDeleteExpr.
+      switch (FD->getOverloadedOperator()) {
+      case OO_New:
+        State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State,
+                             AF_CXXNew);
+        State = ProcessZeroAllocCheck(C, CE, 0, State);
+        break;
+      case OO_Array_New:
+        State = MallocMemAux(C, CE, CE->getArg(0), UndefinedVal(), State,
+                             AF_CXXNewArray);
+        State = ProcessZeroAllocCheck(C, CE, 0, State);
+        break;
+      case OO_Delete:
+      case OO_Array_Delete:
+        State = FreeMemAux(C, CE, State, 0, false, IsKnownToBeAllocatedMemory);
+        break;
+      default:
+        llvm_unreachable("not a new/delete operator");
+      }
+    } else if (FunI == MemFunctionInfo.II_if_nameindex) {
+      // Should we model this differently? We can allocate a fixed number of
+      // elements with zeros in the last one.
+      State = MallocMemAux(C, CE, UnknownVal(), UnknownVal(), State,
+                           AF_IfNameIndex);
+    } else if (FunI == MemFunctionInfo.II_if_freenameindex) {
+      State = FreeMemAux(C, CE, State, 0, false, IsKnownToBeAllocatedMemory);
+    } else if (FunI == MemFunctionInfo.II_g_malloc0 ||
+               FunI == MemFunctionInfo.II_g_try_malloc0) {
+      if (CE->getNumArgs() < 1)
+        return;
+      SValBuilder &svalBuilder = C.getSValBuilder();
+      SVal zeroVal = svalBuilder.makeZeroVal(svalBuilder.getContext().CharTy);
+      State = MallocMemAux(C, CE, CE->getArg(0), zeroVal, State);
+      State = ProcessZeroAllocCheck(C, CE, 0, State);
+    } else if (FunI == MemFunctionInfo.II_g_memdup) {
+      if (CE->getNumArgs() < 2)
+        return;
+      State = MallocMemAux(C, CE, CE->getArg(1), UndefinedVal(), State);
+      State = ProcessZeroAllocCheck(C, CE, 1, State);
+    } else if (FunI == MemFunctionInfo.II_g_malloc_n ||
+               FunI == MemFunctionInfo.II_g_try_malloc_n ||
+               FunI == MemFunctionInfo.II_g_malloc0_n ||
+               FunI == MemFunctionInfo.II_g_try_malloc0_n) {
+      if (CE->getNumArgs() < 2)
+        return;
+      SVal Init = UndefinedVal();
+      if (FunI == MemFunctionInfo.II_g_malloc0_n ||
+          FunI == MemFunctionInfo.II_g_try_malloc0_n) {
+        SValBuilder &SB = C.getSValBuilder();
+        Init = SB.makeZeroVal(SB.getContext().CharTy);
+      }
+      SVal TotalSize = evalMulForBufferSize(C, CE->getArg(0), CE->getArg(1));
+      State = MallocMemAux(C, CE, TotalSize, Init, State);
+      State = ProcessZeroAllocCheck(C, CE, 0, State);
+      State = ProcessZeroAllocCheck(C, CE, 1, State);
+    } else if (FunI == MemFunctionInfo.II_g_realloc_n ||
+               FunI == MemFunctionInfo.II_g_try_realloc_n) {
+      if (CE->getNumArgs() < 3)
+        return;
+      State = ReallocMemAux(C, CE, /*ShouldFreeOnFail*/ false, State,
+                            /*SuffixWithN*/ true);
+      State = ProcessZeroAllocCheck(C, CE, 1, State);
+      State = ProcessZeroAllocCheck(C, CE, 2, State);
+    }
+  }
+
+  if (MemFunctionInfo.ShouldIncludeOwnershipAnnotatedFunctions ||
+      ChecksEnabled[CK_MismatchedDeallocatorChecker]) {
+    // Check all the attributes, if there are any.
+    // There can be multiple of these attributes.
+    if (FD->hasAttrs())
+      for (const auto *I : FD->specific_attrs<OwnershipAttr>()) {
+        switch (I->getOwnKind()) {
+        case OwnershipAttr::Returns:
+          State = MallocMemReturnsAttr(C, CE, I, State);
+          break;
+        case OwnershipAttr::Takes:
+        case OwnershipAttr::Holds:
+          State = FreeMemAttr(C, CE, I, State);
+          break;
+        }
+      }
+  }
+  C.addTransition(State);
+}
+
+// Performs a 0-sized allocations check.
+ProgramStateRef MallocChecker::ProcessZeroAllocCheck(
+    CheckerContext &C, const Expr *E, const unsigned IndexOfSizeArg,
+    ProgramStateRef State, Optional<SVal> RetVal) {
+  if (!State)
+    return nullptr;
+
+  if (!RetVal)
+    RetVal = C.getSVal(E);
+
+  const Expr *Arg = nullptr;
+
+  if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
+    Arg = CE->getArg(IndexOfSizeArg);
+  }
+  else if (const CXXNewExpr *NE = dyn_cast<CXXNewExpr>(E)) {
+    if (NE->isArray())
+      Arg = *NE->getArraySize();
+    else
+      return State;
+  }
+  else
+    llvm_unreachable("not a CallExpr or CXXNewExpr");
+
+  assert(Arg);
+
+  Optional<DefinedSVal> DefArgVal = C.getSVal(Arg).getAs<DefinedSVal>();
+
+  if (!DefArgVal)
+    return State;
+
+  // Check if the allocation size is 0.
+  ProgramStateRef TrueState, FalseState;
+  SValBuilder &SvalBuilder = C.getSValBuilder();
+  DefinedSVal Zero =
+      SvalBuilder.makeZeroVal(Arg->getType()).castAs<DefinedSVal>();
+
+  std::tie(TrueState, FalseState) =
+      State->assume(SvalBuilder.evalEQ(State, *DefArgVal, Zero));
+
+  if (TrueState && !FalseState) {
+    SymbolRef Sym = RetVal->getAsLocSymbol();
+    if (!Sym)
+      return State;
+
+    const RefState *RS = State->get<RegionState>(Sym);
+    if (RS) {
+      if (RS->isAllocated())
+        return TrueState->set<RegionState>(Sym,
+                                          RefState::getAllocatedOfSizeZero(RS));
+      else
+        return State;
+    } else {
+      // Case of zero-size realloc. Historically 'realloc(ptr, 0)' is treated as
+      // 'free(ptr)' and the returned value from 'realloc(ptr, 0)' is not
+      // tracked. Add zero-reallocated Sym to the state to catch references
+      // to zero-allocated memory.
+      return TrueState->add<ReallocSizeZeroSymbols>(Sym);
+    }
+  }
+
+  // Assume the value is non-zero going forward.
+  assert(FalseState);
+  return FalseState;
+}
+
+static QualType getDeepPointeeType(QualType T) {
+  QualType Result = T, PointeeType = T->getPointeeType();
+  while (!PointeeType.isNull()) {
+    Result = PointeeType;
+    PointeeType = PointeeType->getPointeeType();
+  }
+  return Result;
+}
+
+/// \returns true if the constructor invoked by \p NE has an argument of a
+/// pointer/reference to a record type.
+static bool hasNonTrivialConstructorCall(const CXXNewExpr *NE) {
+
+  const CXXConstructExpr *ConstructE = NE->getConstructExpr();
+  if (!ConstructE)
+    return false;
+
+  if (!NE->getAllocatedType()->getAsCXXRecordDecl())
+    return false;
+
+  const CXXConstructorDecl *CtorD = ConstructE->getConstructor();
+
+  // Iterate over the constructor parameters.
+  for (const auto *CtorParam : CtorD->parameters()) {
+
+    QualType CtorParamPointeeT = CtorParam->getType()->getPointeeType();
+    if (CtorParamPointeeT.isNull())
+      continue;
+
+    CtorParamPointeeT = getDeepPointeeType(CtorParamPointeeT);
+
+    if (CtorParamPointeeT->getAsCXXRecordDecl())
+      return true;
+  }
+
+  return false;
+}
+
+void MallocChecker::processNewAllocation(const CXXNewExpr *NE,
+                                         CheckerContext &C,
+                                         SVal Target) const {
+  if (!MemFunctionInfo.isStandardNewDelete(NE->getOperatorNew(),
+                                           C.getASTContext()))
+    return;
+
+  const ParentMap &PM = C.getLocationContext()->getParentMap();
+
+  // Non-trivial constructors have a chance to escape 'this', but marking all
+  // invocations of trivial constructors as escaped would cause too great of
+  // reduction of true positives, so let's just do that for constructors that
+  // have an argument of a pointer-to-record type.
+  if (!PM.isConsumedExpr(NE) && hasNonTrivialConstructorCall(NE))
+    return;
+
+  ProgramStateRef State = C.getState();
+  // The return value from operator new is bound to a specified initialization
+  // value (if any) and we don't want to loose this value. So we call
+  // MallocUpdateRefState() instead of MallocMemAux() which breaks the
+  // existing binding.
+  State = MallocUpdateRefState(C, NE, State, NE->isArray() ? AF_CXXNewArray
+                                                           : AF_CXXNew, Target);
+  State = addExtentSize(C, NE, State, Target);
+  State = ProcessZeroAllocCheck(C, NE, 0, State, Target);
+  C.addTransition(State);
+}
+
+void MallocChecker::checkPostStmt(const CXXNewExpr *NE,
+                                  CheckerContext &C) const {
+  if (!C.getAnalysisManager().getAnalyzerOptions().MayInlineCXXAllocator)
+    processNewAllocation(NE, C, C.getSVal(NE));
+}
+
+void MallocChecker::checkNewAllocator(const CXXNewExpr *NE, SVal Target,
+                                      CheckerContext &C) const {
+  if (!C.wasInlined)
+    processNewAllocation(NE, C, Target);
+}
+
+// Sets the extent value of the MemRegion allocated by
+// new expression NE to its size in Bytes.
+//
+ProgramStateRef MallocChecker::addExtentSize(CheckerContext &C,
+                                             const CXXNewExpr *NE,
+                                             ProgramStateRef State,
+                                             SVal Target) {
+  if (!State)
+    return nullptr;
+  SValBuilder &svalBuilder = C.getSValBuilder();
+  SVal ElementCount;
+  const SubRegion *Region;
+  if (NE->isArray()) {
+    const Expr *SizeExpr = *NE->getArraySize();
+    ElementCount = C.getSVal(SizeExpr);
+    // Store the extent size for the (symbolic)region
+    // containing the elements.
+    Region = Target.getAsRegion()
+                 ->castAs<SubRegion>()
+                 ->StripCasts()
+                 ->castAs<SubRegion>();
+  } else {
+    ElementCount = svalBuilder.makeIntVal(1, true);
+    Region = Target.getAsRegion()->castAs<SubRegion>();
+  }
+
+  // Set the region's extent equal to the Size in Bytes.
+  QualType ElementType = NE->getAllocatedType();
+  ASTContext &AstContext = C.getASTContext();
+  CharUnits TypeSize = AstContext.getTypeSizeInChars(ElementType);
+
+  if (ElementCount.getAs<NonLoc>()) {
+    DefinedOrUnknownSVal Extent = Region->getExtent(svalBuilder);
+    // size in Bytes = ElementCount*TypeSize
+    SVal SizeInBytes = svalBuilder.evalBinOpNN(
+        State, BO_Mul, ElementCount.castAs<NonLoc>(),
+        svalBuilder.makeArrayIndex(TypeSize.getQuantity()),
+        svalBuilder.getArrayIndexType());
+    DefinedOrUnknownSVal extentMatchesSize = svalBuilder.evalEQ(
+        State, Extent, SizeInBytes.castAs<DefinedOrUnknownSVal>());
+    State = State->assume(extentMatchesSize, true);
+  }
+  return State;
+}
+
+void MallocChecker::checkPreStmt(const CXXDeleteExpr *DE,
+                                 CheckerContext &C) const {
+
+  if (!ChecksEnabled[CK_NewDeleteChecker])
+    if (SymbolRef Sym = C.getSVal(DE->getArgument()).getAsSymbol())
+      checkUseAfterFree(Sym, C, DE->getArgument());
+
+  if (!MemFunctionInfo.isStandardNewDelete(DE->getOperatorDelete(),
+                                           C.getASTContext()))
+    return;
+
+  ProgramStateRef State = C.getState();
+  bool IsKnownToBeAllocated;
+  State = FreeMemAux(C, DE->getArgument(), DE, State,
+                     /*Hold*/ false, IsKnownToBeAllocated);
+
+  C.addTransition(State);
+}
+
+static bool isKnownDeallocObjCMethodName(const ObjCMethodCall &Call) {
+  // If the first selector piece is one of the names below, assume that the
+  // object takes ownership of the memory, promising to eventually deallocate it
+  // with free().
+  // Ex:  [NSData dataWithBytesNoCopy:bytes length:10];
+  // (...unless a 'freeWhenDone' parameter is false, but that's checked later.)
+  StringRef FirstSlot = Call.getSelector().getNameForSlot(0);
+  return FirstSlot == "dataWithBytesNoCopy" ||
+         FirstSlot == "initWithBytesNoCopy" ||
+         FirstSlot == "initWithCharactersNoCopy";
+}
+
+static Optional<bool> getFreeWhenDoneArg(const ObjCMethodCall &Call) {
+  Selector S = Call.getSelector();
+
+  // FIXME: We should not rely on fully-constrained symbols being folded.
+  for (unsigned i = 1; i < S.getNumArgs(); ++i)
+    if (S.getNameForSlot(i).equals("freeWhenDone"))
+      return !Call.getArgSVal(i).isZeroConstant();
+
+  return None;
+}
+
+void MallocChecker::checkPostObjCMessage(const ObjCMethodCall &Call,
+                                         CheckerContext &C) const {
+  if (C.wasInlined)
+    return;
+
+  if (!isKnownDeallocObjCMethodName(Call))
+    return;
+
+  if (Optional<bool> FreeWhenDone = getFreeWhenDoneArg(Call))
+    if (!*FreeWhenDone)
+      return;
+
+  if (Call.hasNonZeroCallbackArg())
+    return;
+
+  bool IsKnownToBeAllocatedMemory;
+  ProgramStateRef State =
+      FreeMemAux(C, Call.getArgExpr(0), Call.getOriginExpr(), C.getState(),
+                 /*Hold=*/true, IsKnownToBeAllocatedMemory,
+                 /*RetNullOnFailure=*/true);
+
+  C.addTransition(State);
+}
+
+ProgramStateRef
+MallocChecker::MallocMemReturnsAttr(CheckerContext &C, const CallExpr *CE,
+                                    const OwnershipAttr *Att,
+                                    ProgramStateRef State) const {
+  if (!State)
+    return nullptr;
+
+  if (Att->getModule() != MemFunctionInfo.II_malloc)
+    return nullptr;
+
+  OwnershipAttr::args_iterator I = Att->args_begin(), E = Att->args_end();
+  if (I != E) {
+    return MallocMemAux(C, CE, CE->getArg(I->getASTIndex()), UndefinedVal(),
+                        State);
+  }
+  return MallocMemAux(C, CE, UnknownVal(), UndefinedVal(), State);
+}
+
+ProgramStateRef MallocChecker::MallocMemAux(CheckerContext &C,
+                                            const CallExpr *CE,
+                                            const Expr *SizeEx, SVal Init,
+                                            ProgramStateRef State,
+                                            AllocationFamily Family) {
+  if (!State)
+    return nullptr;
+
+  return MallocMemAux(C, CE, C.getSVal(SizeEx), Init, State, Family);
+}
+
+ProgramStateRef MallocChecker::MallocMemAux(CheckerContext &C,
+                                           const CallExpr *CE,
+                                           SVal Size, SVal Init,
+                                           ProgramStateRef State,
+                                           AllocationFamily Family) {
+  if (!State)
+    return nullptr;
+
+  // We expect the malloc functions to return a pointer.
+  if (!Loc::isLocType(CE->getType()))
+    return nullptr;
+
+  // Bind the return value to the symbolic value from the heap region.
+  // TODO: We could rewrite post visit to eval call; 'malloc' does not have
+  // side effects other than what we model here.
+  unsigned Count = C.blockCount();
+  SValBuilder &svalBuilder = C.getSValBuilder();
+  const LocationContext *LCtx = C.getPredecessor()->getLocationContext();
+  DefinedSVal RetVal = svalBuilder.getConjuredHeapSymbolVal(CE, LCtx, Count)
+      .castAs<DefinedSVal>();
+  State = State->BindExpr(CE, C.getLocationContext(), RetVal);
+
+  // Fill the region with the initialization value.
+  State = State->bindDefaultInitial(RetVal, Init, LCtx);
+
+  // Set the region's extent equal to the Size parameter.
+  const SymbolicRegion *R =
+      dyn_cast_or_null<SymbolicRegion>(RetVal.getAsRegion());
+  if (!R)
+    return nullptr;
+  if (Optional<DefinedOrUnknownSVal> DefinedSize =
+          Size.getAs<DefinedOrUnknownSVal>()) {
+    SValBuilder &svalBuilder = C.getSValBuilder();
+    DefinedOrUnknownSVal Extent = R->getExtent(svalBuilder);
+    DefinedOrUnknownSVal extentMatchesSize =
+        svalBuilder.evalEQ(State, Extent, *DefinedSize);
+
+    State = State->assume(extentMatchesSize, true);
+    assert(State);
+  }
+
+  return MallocUpdateRefState(C, CE, State, Family);
+}
+
+static ProgramStateRef MallocUpdateRefState(CheckerContext &C, const Expr *E,
+                                            ProgramStateRef State,
+                                            AllocationFamily Family,
+                                            Optional<SVal> RetVal) {
+  if (!State)
+    return nullptr;
+
+  // Get the return value.
+  if (!RetVal)
+    RetVal = C.getSVal(E);
+
+  // We expect the malloc functions to return a pointer.
+  if (!RetVal->getAs<Loc>())
+    return nullptr;
+
+  SymbolRef Sym = RetVal->getAsLocSymbol();
+  // This is a return value of a function that was not inlined, such as malloc()
+  // or new(). We've checked that in the caller. Therefore, it must be a symbol.
+  assert(Sym);
+
+  // Set the symbol's state to Allocated.
+  return State->set<RegionState>(Sym, RefState::getAllocated(Family, E));
+}
+
+ProgramStateRef MallocChecker::FreeMemAttr(CheckerContext &C,
+                                           const CallExpr *CE,
+                                           const OwnershipAttr *Att,
+                                           ProgramStateRef State) const {
+  if (!State)
+    return nullptr;
+
+  if (Att->getModule() != MemFunctionInfo.II_malloc)
+    return nullptr;
+
+  bool IsKnownToBeAllocated = false;
+
+  for (const auto &Arg : Att->args()) {
+    ProgramStateRef StateI = FreeMemAux(
+        C, CE, State, Arg.getASTIndex(),
+        Att->getOwnKind() == OwnershipAttr::Holds, IsKnownToBeAllocated);
+    if (StateI)
+      State = StateI;
+  }
+  return State;
+}
+
+ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C, const CallExpr *CE,
+                                          ProgramStateRef State, unsigned Num,
+                                          bool Hold, bool &IsKnownToBeAllocated,
+                                          bool ReturnsNullOnFailure) const {
+  if (!State)
+    return nullptr;
+
+  if (CE->getNumArgs() < (Num + 1))
+    return nullptr;
+
+  return FreeMemAux(C, CE->getArg(Num), CE, State, Hold, IsKnownToBeAllocated,
+                    ReturnsNullOnFailure);
+}
+
+/// Checks if the previous call to free on the given symbol failed - if free
+/// failed, returns true. Also, returns the corresponding return value symbol.
+static bool didPreviousFreeFail(ProgramStateRef State,
+                                SymbolRef Sym, SymbolRef &RetStatusSymbol) {
+  const SymbolRef *Ret = State->get<FreeReturnValue>(Sym);
+  if (Ret) {
+    assert(*Ret && "We should not store the null return symbol");
+    ConstraintManager &CMgr = State->getConstraintManager();
+    ConditionTruthVal FreeFailed = CMgr.isNull(State, *Ret);
+    RetStatusSymbol = *Ret;
+    return FreeFailed.isConstrainedTrue();
+  }
+  return false;
+}
+
+static AllocationFamily
+getAllocationFamily(const MemFunctionInfoTy &MemFunctionInfo, CheckerContext &C,
+                    const Stmt *S) {
+
+  if (!S)
+    return AF_None;
+
+  if (const CallExpr *CE = dyn_cast<CallExpr>(S)) {
+    const FunctionDecl *FD = C.getCalleeDecl(CE);
+
+    if (!FD)
+      FD = dyn_cast<FunctionDecl>(CE->getCalleeDecl());
+
+    ASTContext &Ctx = C.getASTContext();
+
+    if (MemFunctionInfo.isCMemFunction(FD, Ctx, AF_Malloc,
+                                       MemoryOperationKind::MOK_Any))
+      return AF_Malloc;
+
+    if (MemFunctionInfo.isStandardNewDelete(FD, Ctx)) {
+      OverloadedOperatorKind Kind = FD->getOverloadedOperator();
+      if (Kind == OO_New || Kind == OO_Delete)
+        return AF_CXXNew;
+      else if (Kind == OO_Array_New || Kind == OO_Array_Delete)
+        return AF_CXXNewArray;
+    }
+
+    if (MemFunctionInfo.isCMemFunction(FD, Ctx, AF_IfNameIndex,
+                                       MemoryOperationKind::MOK_Any))
+      return AF_IfNameIndex;
+
+    if (MemFunctionInfo.isCMemFunction(FD, Ctx, AF_Alloca,
+                                       MemoryOperationKind::MOK_Any))
+      return AF_Alloca;
+
+    return AF_None;
+  }
+
+  if (const CXXNewExpr *NE = dyn_cast<CXXNewExpr>(S))
+    return NE->isArray() ? AF_CXXNewArray : AF_CXXNew;
+
+  if (const CXXDeleteExpr *DE = dyn_cast<CXXDeleteExpr>(S))
+    return DE->isArrayForm() ? AF_CXXNewArray : AF_CXXNew;
+
+  if (isa<ObjCMessageExpr>(S))
+    return AF_Malloc;
+
+  return AF_None;
+}
+
+static bool printAllocDeallocName(raw_ostream &os, CheckerContext &C,
+                                  const Expr *E) {
+  if (const CallExpr *CE = dyn_cast<CallExpr>(E)) {
+    // FIXME: This doesn't handle indirect calls.
+    const FunctionDecl *FD = CE->getDirectCallee();
+    if (!FD)
+      return false;
+
+    os << *FD;
+    if (!FD->isOverloadedOperator())
+      os << "()";
+    return true;
+  }
+
+  if (const ObjCMessageExpr *Msg = dyn_cast<ObjCMessageExpr>(E)) {
+    if (Msg->isInstanceMessage())
+      os << "-";
+    else
+      os << "+";
+    Msg->getSelector().print(os);
+    return true;
+  }
+
+  if (const CXXNewExpr *NE = dyn_cast<CXXNewExpr>(E)) {
+    os << "'"
+       << getOperatorSpelling(NE->getOperatorNew()->getOverloadedOperator())
+       << "'";
+    return true;
+  }
+
+  if (const CXXDeleteExpr *DE = dyn_cast<CXXDeleteExpr>(E)) {
+    os << "'"
+       << getOperatorSpelling(DE->getOperatorDelete()->getOverloadedOperator())
+       << "'";
+    return true;
+  }
+
+  return false;
+}
+
+static void printExpectedAllocName(raw_ostream &os,
+                                   const MemFunctionInfoTy &MemFunctionInfo,
+                                   CheckerContext &C, const Expr *E) {
+  AllocationFamily Family = getAllocationFamily(MemFunctionInfo, C, E);
+
+  switch(Family) {
+    case AF_Malloc: os << "malloc()"; return;
+    case AF_CXXNew: os << "'new'"; return;
+    case AF_CXXNewArray: os << "'new[]'"; return;
+    case AF_IfNameIndex: os << "'if_nameindex()'"; return;
+    case AF_InnerBuffer: os << "container-specific allocator"; return;
+    case AF_Alloca:
+    case AF_None: llvm_unreachable("not a deallocation expression");
+  }
+}
+
+static void printExpectedDeallocName(raw_ostream &os, AllocationFamily Family) {
+  switch(Family) {
+    case AF_Malloc: os << "free()"; return;
+    case AF_CXXNew: os << "'delete'"; return;
+    case AF_CXXNewArray: os << "'delete[]'"; return;
+    case AF_IfNameIndex: os << "'if_freenameindex()'"; return;
+    case AF_InnerBuffer: os << "container-specific deallocator"; return;
+    case AF_Alloca:
+    case AF_None: llvm_unreachable("suspicious argument");
+  }
+}
+
+ProgramStateRef MallocChecker::FreeMemAux(CheckerContext &C,
+                                          const Expr *ArgExpr,
+                                          const Expr *ParentExpr,
+                                          ProgramStateRef State, bool Hold,
+                                          bool &IsKnownToBeAllocated,
+                                          bool ReturnsNullOnFailure) const {
+
+  if (!State)
+    return nullptr;
+
+  SVal ArgVal = C.getSVal(ArgExpr);
+  if (!ArgVal.getAs<DefinedOrUnknownSVal>())
+    return nullptr;
+  DefinedOrUnknownSVal location = ArgVal.castAs<DefinedOrUnknownSVal>();
+
+  // Check for null dereferences.
+  if (!location.getAs<Loc>())
+    return nullptr;
+
+  // The explicit NULL case, no operation is performed.
+  ProgramStateRef notNullState, nullState;
+  std::tie(notNullState, nullState) = State->assume(location);
+  if (nullState && !notNullState)
+    return nullptr;
+
+  // Unknown values could easily be okay
+  // Undefined values are handled elsewhere
+  if (ArgVal.isUnknownOrUndef())
+    return nullptr;
+
+  const MemRegion *R = ArgVal.getAsRegion();
+
+  // Nonlocs can't be freed, of course.
+  // Non-region locations (labels and fixed addresses) also shouldn't be freed.
+  if (!R) {
+    ReportBadFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
+    return nullptr;
+  }
+
+  R = R->StripCasts();
+
+  // Blocks might show up as heap data, but should not be free()d
+  if (isa<BlockDataRegion>(R)) {
+    ReportBadFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
+    return nullptr;
+  }
+
+  const MemSpaceRegion *MS = R->getMemorySpace();
+
+  // Parameters, locals, statics, globals, and memory returned by
+  // __builtin_alloca() shouldn't be freed.
+  if (!(isa<UnknownSpaceRegion>(MS) || isa<HeapSpaceRegion>(MS))) {
+    // FIXME: at the time this code was written, malloc() regions were
+    // represented by conjured symbols, which are all in UnknownSpaceRegion.
+    // This means that there isn't actually anything from HeapSpaceRegion
+    // that should be freed, even though we allow it here.
+    // Of course, free() can work on memory allocated outside the current
+    // function, so UnknownSpaceRegion is always a possibility.
+    // False negatives are better than false positives.
+
+    if (isa<AllocaRegion>(R))
+      ReportFreeAlloca(C, ArgVal, ArgExpr->getSourceRange());
+    else
+      ReportBadFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
+
+    return nullptr;
+  }
+
+  const SymbolicRegion *SrBase = dyn_cast<SymbolicRegion>(R->getBaseRegion());
+  // Various cases could lead to non-symbol values here.
+  // For now, ignore them.
+  if (!SrBase)
+    return nullptr;
+
+  SymbolRef SymBase = SrBase->getSymbol();
+  const RefState *RsBase = State->get<RegionState>(SymBase);
+  SymbolRef PreviousRetStatusSymbol = nullptr;
+
+  IsKnownToBeAllocated =
+      RsBase && (RsBase->isAllocated() || RsBase->isAllocatedOfSizeZero());
+
+  if (RsBase) {
+
+    // Memory returned by alloca() shouldn't be freed.
+    if (RsBase->getAllocationFamily() == AF_Alloca) {
+      ReportFreeAlloca(C, ArgVal, ArgExpr->getSourceRange());
+      return nullptr;
+    }
+
+    // Check for double free first.
+    if ((RsBase->isReleased() || RsBase->isRelinquished()) &&
+        !didPreviousFreeFail(State, SymBase, PreviousRetStatusSymbol)) {
+      ReportDoubleFree(C, ParentExpr->getSourceRange(), RsBase->isReleased(),
+                       SymBase, PreviousRetStatusSymbol);
+      return nullptr;
+
+    // If the pointer is allocated or escaped, but we are now trying to free it,
+    // check that the call to free is proper.
+    } else if (RsBase->isAllocated() || RsBase->isAllocatedOfSizeZero() ||
+               RsBase->isEscaped()) {
+
+      // Check if an expected deallocation function matches the real one.
+      bool DeallocMatchesAlloc =
+          RsBase->getAllocationFamily() ==
+          getAllocationFamily(MemFunctionInfo, C, ParentExpr);
+      if (!DeallocMatchesAlloc) {
+        ReportMismatchedDealloc(C, ArgExpr->getSourceRange(),
+                                ParentExpr, RsBase, SymBase, Hold);
+        return nullptr;
+      }
+
+      // Check if the memory location being freed is the actual location
+      // allocated, or an offset.
+      RegionOffset Offset = R->getAsOffset();
+      if (Offset.isValid() &&
+          !Offset.hasSymbolicOffset() &&
+          Offset.getOffset() != 0) {
+        const Expr *AllocExpr = cast<Expr>(RsBase->getStmt());
+        ReportOffsetFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr,
+                         AllocExpr);
+        return nullptr;
+      }
+    }
+  }
+
+  if (SymBase->getType()->isFunctionPointerType()) {
+    ReportFunctionPointerFree(C, ArgVal, ArgExpr->getSourceRange(), ParentExpr);
+    return nullptr;
+  }
+
+  // Clean out the info on previous call to free return info.
+  State = State->remove<FreeReturnValue>(SymBase);
+
+  // Keep track of the return value. If it is NULL, we will know that free
+  // failed.
+  if (ReturnsNullOnFailure) {
+    SVal RetVal = C.getSVal(ParentExpr);
+    SymbolRef RetStatusSymbol = RetVal.getAsSymbol();
+    if (RetStatusSymbol) {
+      C.getSymbolManager().addSymbolDependency(SymBase, RetStatusSymbol);
+      State = State->set<FreeReturnValue>(SymBase, RetStatusSymbol);
+    }
+  }
+
+  AllocationFamily Family =
+      RsBase ? RsBase->getAllocationFamily()
+             : getAllocationFamily(MemFunctionInfo, C, ParentExpr);
+  // Normal free.
+  if (Hold)
+    return State->set<RegionState>(SymBase,
+                                   RefState::getRelinquished(Family,
+                                                             ParentExpr));
+
+  return State->set<RegionState>(SymBase,
+                                 RefState::getReleased(Family, ParentExpr));
+}
+
+Optional<MallocChecker::CheckKind>
+MallocChecker::getCheckIfTracked(AllocationFamily Family,
+                                 bool IsALeakCheck) const {
+  switch (Family) {
+  case AF_Malloc:
+  case AF_Alloca:
+  case AF_IfNameIndex: {
+    if (ChecksEnabled[CK_MallocChecker])
+      return CK_MallocChecker;
+    return None;
+  }
+  case AF_CXXNew:
+  case AF_CXXNewArray: {
+    if (IsALeakCheck) {
+      if (ChecksEnabled[CK_NewDeleteLeaksChecker])
+        return CK_NewDeleteLeaksChecker;
+    }
+    else {
+      if (ChecksEnabled[CK_NewDeleteChecker])
+        return CK_NewDeleteChecker;
+    }
+    return None;
+  }
+  case AF_InnerBuffer: {
+    if (ChecksEnabled[CK_InnerPointerChecker])
+      return CK_InnerPointerChecker;
+    return None;
+  }
+  case AF_None: {
+    llvm_unreachable("no family");
+  }
+  }
+  llvm_unreachable("unhandled family");
+}
+
+Optional<MallocChecker::CheckKind>
+MallocChecker::getCheckIfTracked(CheckerContext &C,
+                                 const Stmt *AllocDeallocStmt,
+                                 bool IsALeakCheck) const {
+  return getCheckIfTracked(
+      getAllocationFamily(MemFunctionInfo, C, AllocDeallocStmt), IsALeakCheck);
+}
+
+Optional<MallocChecker::CheckKind>
+MallocChecker::getCheckIfTracked(CheckerContext &C, SymbolRef Sym,
+                                 bool IsALeakCheck) const {
+  if (C.getState()->contains<ReallocSizeZeroSymbols>(Sym))
+    return CK_MallocChecker;
+
+  const RefState *RS = C.getState()->get<RegionState>(Sym);
+  assert(RS);
+  return getCheckIfTracked(RS->getAllocationFamily(), IsALeakCheck);
+}
+
+bool MallocChecker::SummarizeValue(raw_ostream &os, SVal V) {
+  if (Optional<nonloc::ConcreteInt> IntVal = V.getAs<nonloc::ConcreteInt>())
+    os << "an integer (" << IntVal->getValue() << ")";
+  else if (Optional<loc::ConcreteInt> ConstAddr = V.getAs<loc::ConcreteInt>())
+    os << "a constant address (" << ConstAddr->getValue() << ")";
+  else if (Optional<loc::GotoLabel> Label = V.getAs<loc::GotoLabel>())
+    os << "the address of the label '" << Label->getLabel()->getName() << "'";
+  else
+    return false;
+
+  return true;
+}
+
+bool MallocChecker::SummarizeRegion(raw_ostream &os,
+                                    const MemRegion *MR) {
+  switch (MR->getKind()) {
+  case MemRegion::FunctionCodeRegionKind: {
+    const NamedDecl *FD = cast<FunctionCodeRegion>(MR)->getDecl();
+    if (FD)
+      os << "the address of the function '" << *FD << '\'';
+    else
+      os << "the address of a function";
+    return true;
+  }
+  case MemRegion::BlockCodeRegionKind:
+    os << "block text";
+    return true;
+  case MemRegion::BlockDataRegionKind:
+    // FIXME: where the block came from?
+    os << "a block";
+    return true;
+  default: {
+    const MemSpaceRegion *MS = MR->getMemorySpace();
+
+    if (isa<StackLocalsSpaceRegion>(MS)) {
+      const VarRegion *VR = dyn_cast<VarRegion>(MR);
+      const VarDecl *VD;
+      if (VR)
+        VD = VR->getDecl();
+      else
+        VD = nullptr;
+
+      if (VD)
+        os << "the address of the local variable '" << VD->getName() << "'";
+      else
+        os << "the address of a local stack variable";
+      return true;
+    }
+
+    if (isa<StackArgumentsSpaceRegion>(MS)) {
+      const VarRegion *VR = dyn_cast<VarRegion>(MR);
+      const VarDecl *VD;
+      if (VR)
+        VD = VR->getDecl();
+      else
+        VD = nullptr;
+
+      if (VD)
+        os << "the address of the parameter '" << VD->getName() << "'";
+      else
+        os << "the address of a parameter";
+      return true;
+    }
+
+    if (isa<GlobalsSpaceRegion>(MS)) {
+      const VarRegion *VR = dyn_cast<VarRegion>(MR);
+      const VarDecl *VD;
+      if (VR)
+        VD = VR->getDecl();
+      else
+        VD = nullptr;
+
+      if (VD) {
+        if (VD->isStaticLocal())
+          os << "the address of the static variable '" << VD->getName() << "'";
+        else
+          os << "the address of the global variable '" << VD->getName() << "'";
+      } else
+        os << "the address of a global variable";
+      return true;
+    }
+
+    return false;
+  }
+  }
+}
+
+void MallocChecker::ReportBadFree(CheckerContext &C, SVal ArgVal,
+                                  SourceRange Range,
+                                  const Expr *DeallocExpr) const {
+
+  if (!ChecksEnabled[CK_MallocChecker] &&
+      !ChecksEnabled[CK_NewDeleteChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind =
+      getCheckIfTracked(C, DeallocExpr);
+  if (!CheckKind.hasValue())
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_BadFree[*CheckKind])
+      BT_BadFree[*CheckKind].reset(new BugType(
+          CheckNames[*CheckKind], "Bad free", categories::MemoryError));
+
+    SmallString<100> buf;
+    llvm::raw_svector_ostream os(buf);
+
+    const MemRegion *MR = ArgVal.getAsRegion();
+    while (const ElementRegion *ER = dyn_cast_or_null<ElementRegion>(MR))
+      MR = ER->getSuperRegion();
+
+    os << "Argument to ";
+    if (!printAllocDeallocName(os, C, DeallocExpr))
+      os << "deallocator";
+
+    os << " is ";
+    bool Summarized = MR ? SummarizeRegion(os, MR)
+                         : SummarizeValue(os, ArgVal);
+    if (Summarized)
+      os << ", which is not memory allocated by ";
+    else
+      os << "not memory allocated by ";
+
+    printExpectedAllocName(os, MemFunctionInfo, C, DeallocExpr);
+
+    auto R = std::make_unique<PathSensitiveBugReport>(*BT_BadFree[*CheckKind],
+                                                      os.str(), N);
+    R->markInteresting(MR);
+    R->addRange(Range);
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportFreeAlloca(CheckerContext &C, SVal ArgVal,
+                                     SourceRange Range) const {
+
+  Optional<MallocChecker::CheckKind> CheckKind;
+
+  if (ChecksEnabled[CK_MallocChecker])
+    CheckKind = CK_MallocChecker;
+  else if (ChecksEnabled[CK_MismatchedDeallocatorChecker])
+    CheckKind = CK_MismatchedDeallocatorChecker;
+  else
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_FreeAlloca[*CheckKind])
+      BT_FreeAlloca[*CheckKind].reset(new BugType(
+          CheckNames[*CheckKind], "Free alloca()", categories::MemoryError));
+
+    auto R = std::make_unique<PathSensitiveBugReport>(
+        *BT_FreeAlloca[*CheckKind],
+        "Memory allocated by alloca() should not be deallocated", N);
+    R->markInteresting(ArgVal.getAsRegion());
+    R->addRange(Range);
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportMismatchedDealloc(CheckerContext &C,
+                                            SourceRange Range,
+                                            const Expr *DeallocExpr,
+                                            const RefState *RS,
+                                            SymbolRef Sym,
+                                            bool OwnershipTransferred) const {
+
+  if (!ChecksEnabled[CK_MismatchedDeallocatorChecker])
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_MismatchedDealloc)
+      BT_MismatchedDealloc.reset(
+          new BugType(CheckNames[CK_MismatchedDeallocatorChecker],
+                      "Bad deallocator", categories::MemoryError));
+
+    SmallString<100> buf;
+    llvm::raw_svector_ostream os(buf);
+
+    const Expr *AllocExpr = cast<Expr>(RS->getStmt());
+    SmallString<20> AllocBuf;
+    llvm::raw_svector_ostream AllocOs(AllocBuf);
+    SmallString<20> DeallocBuf;
+    llvm::raw_svector_ostream DeallocOs(DeallocBuf);
+
+    if (OwnershipTransferred) {
+      if (printAllocDeallocName(DeallocOs, C, DeallocExpr))
+        os << DeallocOs.str() << " cannot";
+      else
+        os << "Cannot";
+
+      os << " take ownership of memory";
+
+      if (printAllocDeallocName(AllocOs, C, AllocExpr))
+        os << " allocated by " << AllocOs.str();
+    } else {
+      os << "Memory";
+      if (printAllocDeallocName(AllocOs, C, AllocExpr))
+        os << " allocated by " << AllocOs.str();
+
+      os << " should be deallocated by ";
+        printExpectedDeallocName(os, RS->getAllocationFamily());
+
+      if (printAllocDeallocName(DeallocOs, C, DeallocExpr))
+        os << ", not " << DeallocOs.str();
+    }
+
+    auto R = std::make_unique<PathSensitiveBugReport>(*BT_MismatchedDealloc,
+                                                      os.str(), N);
+    R->markInteresting(Sym);
+    R->addRange(Range);
+    R->addVisitor(std::make_unique<MallocBugVisitor>(Sym));
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportOffsetFree(CheckerContext &C, SVal ArgVal,
+                                     SourceRange Range, const Expr *DeallocExpr,
+                                     const Expr *AllocExpr) const {
+
+
+  if (!ChecksEnabled[CK_MallocChecker] &&
+      !ChecksEnabled[CK_NewDeleteChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind =
+      getCheckIfTracked(C, AllocExpr);
+  if (!CheckKind.hasValue())
+    return;
+
+  ExplodedNode *N = C.generateErrorNode();
+  if (!N)
+    return;
+
+  if (!BT_OffsetFree[*CheckKind])
+    BT_OffsetFree[*CheckKind].reset(new BugType(
+        CheckNames[*CheckKind], "Offset free", categories::MemoryError));
+
+  SmallString<100> buf;
+  llvm::raw_svector_ostream os(buf);
+  SmallString<20> AllocNameBuf;
+  llvm::raw_svector_ostream AllocNameOs(AllocNameBuf);
+
+  const MemRegion *MR = ArgVal.getAsRegion();
+  assert(MR && "Only MemRegion based symbols can have offset free errors");
+
+  RegionOffset Offset = MR->getAsOffset();
+  assert((Offset.isValid() &&
+          !Offset.hasSymbolicOffset() &&
+          Offset.getOffset() != 0) &&
+         "Only symbols with a valid offset can have offset free errors");
+
+  int offsetBytes = Offset.getOffset() / C.getASTContext().getCharWidth();
+
+  os << "Argument to ";
+  if (!printAllocDeallocName(os, C, DeallocExpr))
+    os << "deallocator";
+  os << " is offset by "
+     << offsetBytes
+     << " "
+     << ((abs(offsetBytes) > 1) ? "bytes" : "byte")
+     << " from the start of ";
+  if (AllocExpr && printAllocDeallocName(AllocNameOs, C, AllocExpr))
+    os << "memory allocated by " << AllocNameOs.str();
+  else
+    os << "allocated memory";
+
+  auto R = std::make_unique<PathSensitiveBugReport>(*BT_OffsetFree[*CheckKind],
+                                                    os.str(), N);
+  R->markInteresting(MR->getBaseRegion());
+  R->addRange(Range);
+  C.emitReport(std::move(R));
+}
+
+void MallocChecker::ReportUseAfterFree(CheckerContext &C, SourceRange Range,
+                                       SymbolRef Sym) const {
+
+  if (!ChecksEnabled[CK_MallocChecker] &&
+      !ChecksEnabled[CK_NewDeleteChecker] &&
+      !ChecksEnabled[CK_InnerPointerChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind = getCheckIfTracked(C, Sym);
+  if (!CheckKind.hasValue())
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_UseFree[*CheckKind])
+      BT_UseFree[*CheckKind].reset(new BugType(
+          CheckNames[*CheckKind], "Use-after-free", categories::MemoryError));
+
+    AllocationFamily AF =
+        C.getState()->get<RegionState>(Sym)->getAllocationFamily();
+
+    auto R = std::make_unique<PathSensitiveBugReport>(
+        *BT_UseFree[*CheckKind],
+        AF == AF_InnerBuffer
+            ? "Inner pointer of container used after re/deallocation"
+            : "Use of memory after it is freed",
+        N);
+
+    R->markInteresting(Sym);
+    R->addRange(Range);
+    R->addVisitor(std::make_unique<MallocBugVisitor>(Sym));
+
+    if (AF == AF_InnerBuffer)
+      R->addVisitor(allocation_state::getInnerPointerBRVisitor(Sym));
+
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportDoubleFree(CheckerContext &C, SourceRange Range,
+                                     bool Released, SymbolRef Sym,
+                                     SymbolRef PrevSym) const {
+
+  if (!ChecksEnabled[CK_MallocChecker] &&
+      !ChecksEnabled[CK_NewDeleteChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind = getCheckIfTracked(C, Sym);
+  if (!CheckKind.hasValue())
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_DoubleFree[*CheckKind])
+      BT_DoubleFree[*CheckKind].reset(new BugType(
+          CheckNames[*CheckKind], "Double free", categories::MemoryError));
+
+    auto R = std::make_unique<PathSensitiveBugReport>(
+        *BT_DoubleFree[*CheckKind],
+        (Released ? "Attempt to free released memory"
+                  : "Attempt to free non-owned memory"),
+        N);
+    R->addRange(Range);
+    R->markInteresting(Sym);
+    if (PrevSym)
+      R->markInteresting(PrevSym);
+    R->addVisitor(std::make_unique<MallocBugVisitor>(Sym));
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportDoubleDelete(CheckerContext &C, SymbolRef Sym) const {
+
+  if (!ChecksEnabled[CK_NewDeleteChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind = getCheckIfTracked(C, Sym);
+  if (!CheckKind.hasValue())
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_DoubleDelete)
+      BT_DoubleDelete.reset(new BugType(CheckNames[CK_NewDeleteChecker],
+                                        "Double delete",
+                                        categories::MemoryError));
+
+    auto R = std::make_unique<PathSensitiveBugReport>(
+        *BT_DoubleDelete, "Attempt to delete released memory", N);
+
+    R->markInteresting(Sym);
+    R->addVisitor(std::make_unique<MallocBugVisitor>(Sym));
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportUseZeroAllocated(CheckerContext &C,
+                                           SourceRange Range,
+                                           SymbolRef Sym) const {
+
+  if (!ChecksEnabled[CK_MallocChecker] &&
+      !ChecksEnabled[CK_NewDeleteChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind = getCheckIfTracked(C, Sym);
+
+  if (!CheckKind.hasValue())
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_UseZerroAllocated[*CheckKind])
+      BT_UseZerroAllocated[*CheckKind].reset(
+          new BugType(CheckNames[*CheckKind], "Use of zero allocated",
+                      categories::MemoryError));
+
+    auto R = std::make_unique<PathSensitiveBugReport>(
+        *BT_UseZerroAllocated[*CheckKind], "Use of zero-allocated memory", N);
+
+    R->addRange(Range);
+    if (Sym) {
+      R->markInteresting(Sym);
+      R->addVisitor(std::make_unique<MallocBugVisitor>(Sym));
+    }
+    C.emitReport(std::move(R));
+  }
+}
+
+void MallocChecker::ReportFunctionPointerFree(CheckerContext &C, SVal ArgVal,
+                                              SourceRange Range,
+                                              const Expr *FreeExpr) const {
+  if (!ChecksEnabled[CK_MallocChecker])
+    return;
+
+  Optional<MallocChecker::CheckKind> CheckKind = getCheckIfTracked(C, FreeExpr);
+  if (!CheckKind.hasValue())
+    return;
+
+  if (ExplodedNode *N = C.generateErrorNode()) {
+    if (!BT_BadFree[*CheckKind])
+      BT_BadFree[*CheckKind].reset(new BugType(
+          CheckNames[*CheckKind], "Bad free", categories::MemoryError));
+
+    SmallString<100> Buf;
+    llvm::raw_svector_ostream Os(Buf);
+
+    const MemRegion *MR = ArgVal.getAsRegion();
+    while (const ElementRegion *ER = dyn_cast_or_null<ElementRegion>(MR))
+      MR = ER->getSuperRegion();
+
+    Os << "Argument to ";
+    if (!printAllocDeallocName(Os, C, FreeExpr))
+      Os << "deallocator";
+
+    Os << " is a function pointer";
+
+    auto R = std::make_unique<PathSensitiveBugReport>(*BT_BadFree[*CheckKind],
+                                                      Os.str(), N);
+    R->markInteresting(MR);
+    R->addRange(Range);
+    C.emitReport(std::move(R));
+  }
+}
+
+ProgramStateRef MallocChecker::ReallocMemAux(CheckerContext &C,
+                                             const CallExpr *CE,
+                                             bool ShouldFreeOnFail,
+                                             ProgramStateRef State,
+                                             bool SuffixWithN) const {
+  if (!State)
+    return nullptr;
+
+  if (SuffixWithN && CE->getNumArgs() < 3)
+    return nullptr;
+  else if (CE->getNumArgs() < 2)
+    return nullptr;
+
+  const Expr *arg0Expr = CE->getArg(0);
+  SVal Arg0Val = C.getSVal(arg0Expr);
+  if (!Arg0Val.getAs<DefinedOrUnknownSVal>())
+    return nullptr;
+  DefinedOrUnknownSVal arg0Val = Arg0Val.castAs<DefinedOrUnknownSVal>();
+
+  SValBuilder &svalBuilder = C.getSValBuilder();
+
+  DefinedOrUnknownSVal PtrEQ =
+    svalBuilder.evalEQ(State, arg0Val, svalBuilder.makeNull());
+
+  // Get the size argument.
+  const Expr *Arg1 = CE->getArg(1);
+
+  // Get the value of the size argument.
+  SVal TotalSize = C.getSVal(Arg1);
+  if (SuffixWithN)
+    TotalSize = evalMulForBufferSize(C, Arg1, CE->getArg(2));
+  if (!TotalSize.getAs<DefinedOrUnknownSVal>())
+    return nullptr;
+
+  // Compare the size argument to 0.
+  DefinedOrUnknownSVal SizeZero =
+    svalBuilder.evalEQ(State, TotalSize.castAs<DefinedOrUnknownSVal>(),
+                       svalBuilder.makeIntValWithPtrWidth(0, false));
+
+  ProgramStateRef StatePtrIsNull, StatePtrNotNull;
+  std::tie(StatePtrIsNull, StatePtrNotNull) = State->assume(PtrEQ);
+  ProgramStateRef StateSizeIsZero, StateSizeNotZero;
+  std::tie(StateSizeIsZero, StateSizeNotZero) = State->assume(SizeZero);
+  // We only assume exceptional states if they are definitely true; if the
+  // state is under-constrained, assume regular realloc behavior.
+  bool PrtIsNull = StatePtrIsNull && !StatePtrNotNull;
+  bool SizeIsZero = StateSizeIsZero && !StateSizeNotZero;
+
+  // If the ptr is NULL and the size is not 0, the call is equivalent to
+  // malloc(size).
+  if (PrtIsNull && !SizeIsZero) {
+    ProgramStateRef stateMalloc = MallocMemAux(C, CE, TotalSize,
+                                               UndefinedVal(), StatePtrIsNull);
+    return stateMalloc;
+  }
+
+  if (PrtIsNull && SizeIsZero)
+    return State;
+
+  // Get the from and to pointer symbols as in toPtr = realloc(fromPtr, size).
+  assert(!PrtIsNull);
+  SymbolRef FromPtr = arg0Val.getAsSymbol();
+  SVal RetVal = C.getSVal(CE);
+  SymbolRef ToPtr = RetVal.getAsSymbol();
+  if (!FromPtr || !ToPtr)
+    return nullptr;
+
+  bool IsKnownToBeAllocated = false;
+
+  // If the size is 0, free the memory.
+  if (SizeIsZero)
+    // The semantics of the return value are:
+    // If size was equal to 0, either NULL or a pointer suitable to be passed
+    // to free() is returned. We just free the input pointer and do not add
+    // any constrains on the output pointer.
+    if (ProgramStateRef stateFree =
+            FreeMemAux(C, CE, StateSizeIsZero, 0, false, IsKnownToBeAllocated))
+      return stateFree;
+
+  // Default behavior.
+  if (ProgramStateRef stateFree =
+          FreeMemAux(C, CE, State, 0, false, IsKnownToBeAllocated)) {
+
+    ProgramStateRef stateRealloc = MallocMemAux(C, CE, TotalSize,
+                                                UnknownVal(), stateFree);
+    if (!stateRealloc)
+      return nullptr;
+
+    OwnershipAfterReallocKind Kind = OAR_ToBeFreedAfterFailure;
+    if (ShouldFreeOnFail)
+      Kind = OAR_FreeOnFailure;
+    else if (!IsKnownToBeAllocated)
+      Kind = OAR_DoNotTrackAfterFailure;
+
+    // Record the info about the reallocated symbol so that we could properly
+    // process failed reallocation.
+    stateRealloc = stateRealloc->set<ReallocPairs>(ToPtr,
+                                                   ReallocPair(FromPtr, Kind));
+    // The reallocated symbol should stay alive for as long as the new symbol.
+    C.getSymbolManager().addSymbolDependency(ToPtr, FromPtr);
+    return stateRealloc;
+  }
+  return nullptr;
+}
+
+ProgramStateRef MallocChecker::CallocMem(CheckerContext &C, const CallExpr *CE,
+                                         ProgramStateRef State) {
+  if (!State)
+    return nullptr;
+
+  if (CE->getNumArgs() < 2)
+    return nullptr;
+
+  SValBuilder &svalBuilder = C.getSValBuilder();
+  SVal zeroVal = svalBuilder.makeZeroVal(svalBuilder.getContext().CharTy);
+  SVal TotalSize = evalMulForBufferSize(C, CE->getArg(0), CE->getArg(1));
+
+  return MallocMemAux(C, CE, TotalSize, zeroVal, State);
+}
+
+MallocChecker::LeakInfo MallocChecker::getAllocationSite(const ExplodedNode *N,
+                                                         SymbolRef Sym,
+                                                         CheckerContext &C) {
+  const LocationContext *LeakContext = N->getLocationContext();
+  // Walk the ExplodedGraph backwards and find the first node that referred to
+  // the tracked symbol.
+  const ExplodedNode *AllocNode = N;
+  const MemRegion *ReferenceRegion = nullptr;
+
+  while (N) {
+    ProgramStateRef State = N->getState();
+    if (!State->get<RegionState>(Sym))
+      break;
+
+    // Find the most recent expression bound to the symbol in the current
+    // context.
+    if (!ReferenceRegion) {
+      if (const MemRegion *MR = C.getLocationRegionIfPostStore(N)) {
+        SVal Val = State->getSVal(MR);
+        if (Val.getAsLocSymbol() == Sym) {
+          const VarRegion *VR = MR->getBaseRegion()->getAs<VarRegion>();
+          // Do not show local variables belonging to a function other than
+          // where the error is reported.
+          if (!VR || (VR->getStackFrame() == LeakContext->getStackFrame()))
+            ReferenceRegion = MR;
+        }
+      }
+    }
+
+    // Allocation node, is the last node in the current or parent context in
+    // which the symbol was tracked.
+    const LocationContext *NContext = N->getLocationContext();
+    if (NContext == LeakContext ||
+        NContext->isParentOf(LeakContext))
+      AllocNode = N;
+    N = N->pred_empty() ? nullptr : *(N->pred_begin());
+  }
+
+  return LeakInfo(AllocNode, ReferenceRegion);
+}
+
+void MallocChecker::reportLeak(SymbolRef Sym, ExplodedNode *N,
+                               CheckerContext &C) const {
+
+  if (!ChecksEnabled[CK_MallocChecker] &&
+      !ChecksEnabled[CK_NewDeleteLeaksChecker])
+    return;
+
+  const RefState *RS = C.getState()->get<RegionState>(Sym);
+  assert(RS && "cannot leak an untracked symbol");
+  AllocationFamily Family = RS->getAllocationFamily();
+
+  if (Family == AF_Alloca)
+    return;
+
+  Optional<MallocChecker::CheckKind>
+      CheckKind = getCheckIfTracked(Family, true);
+
+  if (!CheckKind.hasValue())
+    return;
+
+  assert(N);
+  if (!BT_Leak[*CheckKind]) {
+    // Leaks should not be reported if they are post-dominated by a sink:
+    // (1) Sinks are higher importance bugs.
+    // (2) NoReturnFunctionChecker uses sink nodes to represent paths ending
+    //     with __noreturn functions such as assert() or exit(). We choose not
+    //     to report leaks on such paths.
+    BT_Leak[*CheckKind].reset(new BugType(CheckNames[*CheckKind], "Memory leak",
+                                          categories::MemoryError,
+                                          /*SuppressOnSink=*/true));
+  }
+
+  // Most bug reports are cached at the location where they occurred.
+  // With leaks, we want to unique them by the location where they were
+  // allocated, and only report a single path.
+  PathDiagnosticLocation LocUsedForUniqueing;
+  const ExplodedNode *AllocNode = nullptr;
+  const MemRegion *Region = nullptr;
+  std::tie(AllocNode, Region) = getAllocationSite(N, Sym, C);
+
+  const Stmt *AllocationStmt = AllocNode->getStmtForDiagnostics();
+  if (AllocationStmt)
+    LocUsedForUniqueing = PathDiagnosticLocation::createBegin(AllocationStmt,
+                                              C.getSourceManager(),
+                                              AllocNode->getLocationContext());
+
+  SmallString<200> buf;
+  llvm::raw_svector_ostream os(buf);
+  if (Region && Region->canPrintPretty()) {
+    os << "Potential leak of memory pointed to by ";
+    Region->printPretty(os);
+  } else {
+    os << "Potential memory leak";
+  }
+
+  auto R = std::make_unique<PathSensitiveBugReport>(
+      *BT_Leak[*CheckKind], os.str(), N, LocUsedForUniqueing,
+      AllocNode->getLocationContext()->getDecl());
+  R->markInteresting(Sym);
+  R->addVisitor(std::make_unique<MallocBugVisitor>(Sym, true));
+  C.emitReport(std::move(R));
+}
+
+void MallocChecker::checkDeadSymbols(SymbolReaper &SymReaper,
+                                     CheckerContext &C) const
+{
+  ProgramStateRef state = C.getState();
+  RegionStateTy OldRS = state->get<RegionState>();
+  RegionStateTy::Factory &F = state->get_context<RegionState>();
+
+  RegionStateTy RS = OldRS;
+  SmallVector<SymbolRef, 2> Errors;
+  for (RegionStateTy::iterator I = RS.begin(), E = RS.end(); I != E; ++I) {
+    if (SymReaper.isDead(I->first)) {
+      if (I->second.isAllocated() || I->second.isAllocatedOfSizeZero())
+        Errors.push_back(I->first);
+      // Remove the dead symbol from the map.
+      RS = F.remove(RS, I->first);
+    }
+  }
+
+  if (RS == OldRS) {
+    // We shouldn't have touched other maps yet.
+    assert(state->get<ReallocPairs>() ==
+           C.getState()->get<ReallocPairs>());
+    assert(state->get<FreeReturnValue>() ==
+           C.getState()->get<FreeReturnValue>());
+    return;
+  }
+
+  // Cleanup the Realloc Pairs Map.
+  ReallocPairsTy RP = state->get<ReallocPairs>();
+  for (ReallocPairsTy::iterator I = RP.begin(), E = RP.end(); I != E; ++I) {
+    if (SymReaper.isDead(I->first) ||
+        SymReaper.isDead(I->second.ReallocatedSym)) {
+      state = state->remove<ReallocPairs>(I->first);
+    }
+  }
+
+  // Cleanup the FreeReturnValue Map.
+  FreeReturnValueTy FR = state->get<FreeReturnValue>();
+  for (FreeReturnValueTy::iterator I = FR.begin(), E = FR.end(); I != E; ++I) {
+    if (SymReaper.isDead(I->first) ||
+        SymReaper.isDead(I->second)) {
+      state = state->remove<FreeReturnValue>(I->first);
+    }
+  }
+
+  // Generate leak node.
+  ExplodedNode *N = C.getPredecessor();
+  if (!Errors.empty()) {
+    static CheckerProgramPointTag Tag("MallocChecker", "DeadSymbolsLeak");
+    N = C.generateNonFatalErrorNode(C.getState(), &Tag);
+    if (N) {
+      for (SmallVectorImpl<SymbolRef>::iterator
+           I = Errors.begin(), E = Errors.end(); I != E; ++I) {
+        reportLeak(*I, N, C);
+      }
+    }
+  }
+
+  C.addTransition(state->set<RegionState>(RS), N);
+}
+
+void MallocChecker::checkPreCall(const CallEvent &Call,
+                                 CheckerContext &C) const {
+
+  if (const CXXDestructorCall *DC = dyn_cast<CXXDestructorCall>(&Call)) {
+    SymbolRef Sym = DC->getCXXThisVal().getAsSymbol();
+    if (!Sym || checkDoubleDelete(Sym, C))
+      return;
+  }
+
+  // We will check for double free in the post visit.
+  if (const AnyFunctionCall *FC = dyn_cast<AnyFunctionCall>(&Call)) {
+    const FunctionDecl *FD = FC->getDecl();
+    if (!FD)
+      return;
+
+    ASTContext &Ctx = C.getASTContext();
+    if (ChecksEnabled[CK_MallocChecker] &&
+        (MemFunctionInfo.isCMemFunction(FD, Ctx, AF_Malloc,
+                                        MemoryOperationKind::MOK_Free) ||
+         MemFunctionInfo.isCMemFunction(FD, Ctx, AF_IfNameIndex,
+                                        MemoryOperationKind::MOK_Free)))
+      return;
+  }
+
+  // Check if the callee of a method is deleted.
+  if (const CXXInstanceCall *CC = dyn_cast<CXXInstanceCall>(&Call)) {
+    SymbolRef Sym = CC->getCXXThisVal().getAsSymbol();
+    if (!Sym || checkUseAfterFree(Sym, C, CC->getCXXThisExpr()))
+      return;
+  }
+
+  // Check arguments for being used after free.
+  for (unsigned I = 0, E = Call.getNumArgs(); I != E; ++I) {
+    SVal ArgSVal = Call.getArgSVal(I);
+    if (ArgSVal.getAs<Loc>()) {
+      SymbolRef Sym = ArgSVal.getAsSymbol();
+      if (!Sym)
+        continue;
+      if (checkUseAfterFree(Sym, C, Call.getArgExpr(I)))
+        return;
+    }
+  }
+}
+
+void MallocChecker::checkPreStmt(const ReturnStmt *S,
+                                 CheckerContext &C) const {
+  checkEscapeOnReturn(S, C);
+}
+
+// In the CFG, automatic destructors come after the return statement.
+// This callback checks for returning memory that is freed by automatic
+// destructors, as those cannot be reached in checkPreStmt().
+void MallocChecker::checkEndFunction(const ReturnStmt *S,
+                                     CheckerContext &C) const {
+  checkEscapeOnReturn(S, C);
+}
+
+void MallocChecker::checkEscapeOnReturn(const ReturnStmt *S,
+                                        CheckerContext &C) const {
+  if (!S)
+    return;
+
+  const Expr *E = S->getRetValue();
+  if (!E)
+    return;
+
+  // Check if we are returning a symbol.
+  ProgramStateRef State = C.getState();
+  SVal RetVal = C.getSVal(E);
+  SymbolRef Sym = RetVal.getAsSymbol();
+  if (!Sym)
+    // If we are returning a field of the allocated struct or an array element,
+    // the callee could still free the memory.
+    // TODO: This logic should be a part of generic symbol escape callback.
+    if (const MemRegion *MR = RetVal.getAsRegion())
+      if (isa<FieldRegion>(MR) || isa<ElementRegion>(MR))
+        if (const SymbolicRegion *BMR =
+              dyn_cast<SymbolicRegion>(MR->getBaseRegion()))
+          Sym = BMR->getSymbol();
+
+  // Check if we are returning freed memory.
+  if (Sym)
+    checkUseAfterFree(Sym, C, E);
+}
+
+// TODO: Blocks should be either inlined or should call invalidate regions
+// upon invocation. After that's in place, special casing here will not be
+// needed.
+void MallocChecker::checkPostStmt(const BlockExpr *BE,
+                                  CheckerContext &C) const {
+
+  // Scan the BlockDecRefExprs for any object the retain count checker
+  // may be tracking.
+  if (!BE->getBlockDecl()->hasCaptures())
+    return;
+
+  ProgramStateRef state = C.getState();
+  const BlockDataRegion *R =
+    cast<BlockDataRegion>(C.getSVal(BE).getAsRegion());
+
+  BlockDataRegion::referenced_vars_iterator I = R->referenced_vars_begin(),
+                                            E = R->referenced_vars_end();
+
+  if (I == E)
+    return;
+
+  SmallVector<const MemRegion*, 10> Regions;
+  const LocationContext *LC = C.getLocationContext();
+  MemRegionManager &MemMgr = C.getSValBuilder().getRegionManager();
+
+  for ( ; I != E; ++I) {
+    const VarRegion *VR = I.getCapturedRegion();
+    if (VR->getSuperRegion() == R) {
+      VR = MemMgr.getVarRegion(VR->getDecl(), LC);
+    }
+    Regions.push_back(VR);
+  }
+
+  state =
+    state->scanReachableSymbols<StopTrackingCallback>(Regions).getState();
+  C.addTransition(state);
+}
+
+static bool isReleased(SymbolRef Sym, CheckerContext &C) {
+  assert(Sym);
+  const RefState *RS = C.getState()->get<RegionState>(Sym);
+  return (RS && RS->isReleased());
+}
+
+bool MallocChecker::suppressDeallocationsInSuspiciousContexts(
+    const CallExpr *CE, CheckerContext &C) const {
+  if (CE->getNumArgs() == 0)
+    return false;
+
+  StringRef FunctionStr = "";
+  if (const auto *FD = dyn_cast<FunctionDecl>(C.getStackFrame()->getDecl()))
+    if (const Stmt *Body = FD->getBody())
+      if (Body->getBeginLoc().isValid())
+        FunctionStr =
+            Lexer::getSourceText(CharSourceRange::getTokenRange(
+                                     {FD->getBeginLoc(), Body->getBeginLoc()}),
+                                 C.getSourceManager(), C.getLangOpts());
+
+  // We do not model the Integer Set Library's retain-count based allocation.
+  if (!FunctionStr.contains("__isl_"))
+    return false;
+
+  ProgramStateRef State = C.getState();
+
+  for (const Expr *Arg : CE->arguments())
+    if (SymbolRef Sym = C.getSVal(Arg).getAsSymbol())
+      if (const RefState *RS = State->get<RegionState>(Sym))
+        State = State->set<RegionState>(Sym, RefState::getEscaped(RS));
+
+  C.addTransition(State);
+  return true;
+}
+
+bool MallocChecker::checkUseAfterFree(SymbolRef Sym, CheckerContext &C,
+                                      const Stmt *S) const {
+
+  if (isReleased(Sym, C)) {
+    ReportUseAfterFree(C, S->getSourceRange(), Sym);
+    return true;
+  }
+
+  return false;
+}
+
+void MallocChecker::checkUseZeroAllocated(SymbolRef Sym, CheckerContext &C,
+                                          const Stmt *S) const {
+  assert(Sym);
+
+  if (const RefState *RS = C.getState()->get<RegionState>(Sym)) {
+    if (RS->isAllocatedOfSizeZero())
+      ReportUseZeroAllocated(C, RS->getStmt()->getSourceRange(), Sym);
+  }
+  else if (C.getState()->contains<ReallocSizeZeroSymbols>(Sym)) {
+    ReportUseZeroAllocated(C, S->getSourceRange(), Sym);
+  }
+}
+
+bool MallocChecker::checkDoubleDelete(SymbolRef Sym, CheckerContext &C) const {
+
+  if (isReleased(Sym, C)) {
+    ReportDoubleDelete(C, Sym);
+    return true;
+  }
+  return false;
+}
+
+// Check if the location is a freed symbolic region.
+void MallocChecker::checkLocation(SVal l, bool isLoad, const Stmt *S,
+                                  CheckerContext &C) const {
+  SymbolRef Sym = l.getLocSymbolInBase();
+  if (Sym) {
+    checkUseAfterFree(Sym, C, S);
+    checkUseZeroAllocated(Sym, C, S);
+  }
+}
+
+// If a symbolic region is assumed to NULL (or another constant), stop tracking
+// it - assuming that allocation failed on this path.
+ProgramStateRef MallocChecker::evalAssume(ProgramStateRef state,
+                                              SVal Cond,
+                                              bool Assumption) const {
+  RegionStateTy RS = state->get<RegionState>();
+  for (RegionStateTy::iterator I = RS.begin(), E = RS.end(); I != E; ++I) {
+    // If the symbol is assumed to be NULL, remove it from consideration.
+    ConstraintManager &CMgr = state->getConstraintManager();
+    ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey());
+    if (AllocFailed.isConstrainedTrue())
+      state = state->remove<RegionState>(I.getKey());
+  }
+
+  // Realloc returns 0 when reallocation fails, which means that we should
+  // restore the state of the pointer being reallocated.
+  ReallocPairsTy RP = state->get<ReallocPairs>();
+  for (ReallocPairsTy::iterator I = RP.begin(), E = RP.end(); I != E; ++I) {
+    // If the symbol is assumed to be NULL, remove it from consideration.
+    ConstraintManager &CMgr = state->getConstraintManager();
+    ConditionTruthVal AllocFailed = CMgr.isNull(state, I.getKey());
+    if (!AllocFailed.isConstrainedTrue())
+      continue;
+
+    SymbolRef ReallocSym = I.getData().ReallocatedSym;
+    if (const RefState *RS = state->get<RegionState>(ReallocSym)) {
+      if (RS->isReleased()) {
+        switch (I.getData().Kind) {
+        case OAR_ToBeFreedAfterFailure:
+          state = state->set<RegionState>(ReallocSym,
+              RefState::getAllocated(RS->getAllocationFamily(), RS->getStmt()));
+          break;
+        case OAR_DoNotTrackAfterFailure:
+          state = state->remove<RegionState>(ReallocSym);
+          break;
+        default:
+          assert(I.getData().Kind == OAR_FreeOnFailure);
+        }
+      }
+    }
+    state = state->remove<ReallocPairs>(I.getKey());
+  }
+
+  return state;
+}
+
+bool MallocChecker::mayFreeAnyEscapedMemoryOrIsModeledExplicitly(
+                                              const CallEvent *Call,
+                                              ProgramStateRef State,
+                                              SymbolRef &EscapingSymbol) const {
+  assert(Call);
+  EscapingSymbol = nullptr;
+
+  // For now, assume that any C++ or block call can free memory.
+  // TODO: If we want to be more optimistic here, we'll need to make sure that
+  // regions escape to C++ containers. They seem to do that even now, but for
+  // mysterious reasons.
+  if (!(isa<SimpleFunctionCall>(Call) || isa<ObjCMethodCall>(Call)))
+    return true;
+
+  // Check Objective-C messages by selector name.
+  if (const ObjCMethodCall *Msg = dyn_cast<ObjCMethodCall>(Call)) {
+    // If it's not a framework call, or if it takes a callback, assume it
+    // can free memory.
+    if (!Call->isInSystemHeader() || Call->argumentsMayEscape())
+      return true;
+
+    // If it's a method we know about, handle it explicitly post-call.
+    // This should happen before the "freeWhenDone" check below.
+    if (isKnownDeallocObjCMethodName(*Msg))
+      return false;
+
+    // If there's a "freeWhenDone" parameter, but the method isn't one we know
+    // about, we can't be sure that the object will use free() to deallocate the
+    // memory, so we can't model it explicitly. The best we can do is use it to
+    // decide whether the pointer escapes.
+    if (Optional<bool> FreeWhenDone = getFreeWhenDoneArg(*Msg))
+      return *FreeWhenDone;
+
+    // If the first selector piece ends with "NoCopy", and there is no
+    // "freeWhenDone" parameter set to zero, we know ownership is being
+    // transferred. Again, though, we can't be sure that the object will use
+    // free() to deallocate the memory, so we can't model it explicitly.
+    StringRef FirstSlot = Msg->getSelector().getNameForSlot(0);
+    if (FirstSlot.endswith("NoCopy"))
+      return true;
+
+    // If the first selector starts with addPointer, insertPointer,
+    // or replacePointer, assume we are dealing with NSPointerArray or similar.
+    // This is similar to C++ containers (vector); we still might want to check
+    // that the pointers get freed by following the container itself.
+    if (FirstSlot.startswith("addPointer") ||
+        FirstSlot.startswith("insertPointer") ||
+        FirstSlot.startswith("replacePointer") ||
+        FirstSlot.equals("valueWithPointer")) {
+      return true;
+    }
+
+    // We should escape receiver on call to 'init'. This is especially relevant
+    // to the receiver, as the corresponding symbol is usually not referenced
+    // after the call.
+    if (Msg->getMethodFamily() == OMF_init) {
+      EscapingSymbol = Msg->getReceiverSVal().getAsSymbol();
+      return true;
+    }
+
+    // Otherwise, assume that the method does not free memory.
+    // Most framework methods do not free memory.
+    return false;
+  }
+
+  // At this point the only thing left to handle is straight function calls.
+  const FunctionDecl *FD = cast<SimpleFunctionCall>(Call)->getDecl();
+  if (!FD)
+    return true;
+
+  ASTContext &ASTC = State->getStateManager().getContext();
+
+  // If it's one of the allocation functions we can reason about, we model
+  // its behavior explicitly.
+  if (MemFunctionInfo.isMemFunction(FD, ASTC))
+    return false;
+
+  // If it's not a system call, assume it frees memory.
+  if (!Call->isInSystemHeader())
+    return true;
+
+  // White list the system functions whose arguments escape.
+  const IdentifierInfo *II = FD->getIdentifier();
+  if (!II)
+    return true;
+  StringRef FName = II->getName();
+
+  // White list the 'XXXNoCopy' CoreFoundation functions.
+  // We specifically check these before
+  if (FName.endswith("NoCopy")) {
+    // Look for the deallocator argument. We know that the memory ownership
+    // is not transferred only if the deallocator argument is
+    // 'kCFAllocatorNull'.
+    for (unsigned i = 1; i < Call->getNumArgs(); ++i) {
+      const Expr *ArgE = Call->getArgExpr(i)->IgnoreParenCasts();
+      if (const DeclRefExpr *DE = dyn_cast<DeclRefExpr>(ArgE)) {
+        StringRef DeallocatorName = DE->getFoundDecl()->getName();
+        if (DeallocatorName == "kCFAllocatorNull")
+          return false;
+      }
+    }
+    return true;
+  }
+
+  // Associating streams with malloced buffers. The pointer can escape if
+  // 'closefn' is specified (and if that function does free memory),
+  // but it will not if closefn is not specified.
+  // Currently, we do not inspect the 'closefn' function (PR12101).
+  if (FName == "funopen")
+    if (Call->getNumArgs() >= 4 && Call->getArgSVal(4).isConstant(0))
+      return false;
+
+  // Do not warn on pointers passed to 'setbuf' when used with std streams,
+  // these leaks might be intentional when setting the buffer for stdio.
+  // http://stackoverflow.com/questions/2671151/who-frees-setvbuf-buffer
+  if (FName == "setbuf" || FName =="setbuffer" ||
+      FName == "setlinebuf" || FName == "setvbuf") {
+    if (Call->getNumArgs() >= 1) {
+      const Expr *ArgE = Call->getArgExpr(0)->IgnoreParenCasts();
+      if (const DeclRefExpr *ArgDRE = dyn_cast<DeclRefExpr>(ArgE))
+        if (const VarDecl *D = dyn_cast<VarDecl>(ArgDRE->getDecl()))
+          if (D->getCanonicalDecl()->getName().find("std") != StringRef::npos)
+            return true;
+    }
+  }
+
+  // A bunch of other functions which either take ownership of a pointer or
+  // wrap the result up in a struct or object, meaning it can be freed later.
+  // (See RetainCountChecker.) Not all the parameters here are invalidated,
+  // but the Malloc checker cannot differentiate between them. The right way
+  // of doing this would be to implement a pointer escapes callback.
+  if (FName == "CGBitmapContextCreate" ||
+      FName == "CGBitmapContextCreateWithData" ||
+      FName == "CVPixelBufferCreateWithBytes" ||
+      FName == "CVPixelBufferCreateWithPlanarBytes" ||
+      FName == "OSAtomicEnqueue") {
+    return true;
+  }
+
+  if (FName == "postEvent" &&
+      FD->getQualifiedNameAsString() == "QCoreApplication::postEvent") {
+    return true;
+  }
+
+  if (FName == "postEvent" &&
+      FD->getQualifiedNameAsString() == "QCoreApplication::postEvent") {
+    return true;
+  }
+
+  if (FName == "connectImpl" &&
+      FD->getQualifiedNameAsString() == "QObject::connectImpl") {
+    return true;
+  }
+
+  // Handle cases where we know a buffer's /address/ can escape.
+  // Note that the above checks handle some special cases where we know that
+  // even though the address escapes, it's still our responsibility to free the
+  // buffer.
+  if (Call->argumentsMayEscape())
+    return true;
+
+  // Otherwise, assume that the function does not free memory.
+  // Most system calls do not free the memory.
+  return false;
+}
+
+ProgramStateRef MallocChecker::checkPointerEscape(ProgramStateRef State,
+                                             const InvalidatedSymbols &Escaped,
+                                             const CallEvent *Call,
+                                             PointerEscapeKind Kind) const {
+  return checkPointerEscapeAux(State, Escaped, Call, Kind,
+                               /*IsConstPointerEscape*/ false);
+}
+
+ProgramStateRef MallocChecker::checkConstPointerEscape(ProgramStateRef State,
+                                              const InvalidatedSymbols &Escaped,
+                                              const CallEvent *Call,
+                                              PointerEscapeKind Kind) const {
+  // If a const pointer escapes, it may not be freed(), but it could be deleted.
+  return checkPointerEscapeAux(State, Escaped, Call, Kind,
+                               /*IsConstPointerEscape*/ true);
+}
+
+static bool checkIfNewOrNewArrayFamily(const RefState *RS) {
+  return (RS->getAllocationFamily() == AF_CXXNewArray ||
+          RS->getAllocationFamily() == AF_CXXNew);
+}
+
+ProgramStateRef MallocChecker::checkPointerEscapeAux(
+    ProgramStateRef State, const InvalidatedSymbols &Escaped,
+    const CallEvent *Call, PointerEscapeKind Kind,
+    bool IsConstPointerEscape) const {
+  // If we know that the call does not free memory, or we want to process the
+  // call later, keep tracking the top level arguments.
+  SymbolRef EscapingSymbol = nullptr;
+  if (Kind == PSK_DirectEscapeOnCall &&
+      !mayFreeAnyEscapedMemoryOrIsModeledExplicitly(Call, State,
+                                                    EscapingSymbol) &&
+      !EscapingSymbol) {
+    return State;
+  }
+
+  for (InvalidatedSymbols::const_iterator I = Escaped.begin(),
+       E = Escaped.end();
+       I != E; ++I) {
+    SymbolRef sym = *I;
+
+    if (EscapingSymbol && EscapingSymbol != sym)
+      continue;
+
+    if (const RefState *RS = State->get<RegionState>(sym))
+      if (RS->isAllocated() || RS->isAllocatedOfSizeZero())
+        if (!IsConstPointerEscape || checkIfNewOrNewArrayFamily(RS))
+          State = State->set<RegionState>(sym, RefState::getEscaped(RS));
+  }
+  return State;
+}
+
+static SymbolRef findFailedReallocSymbol(ProgramStateRef currState,
+                                         ProgramStateRef prevState) {
+  ReallocPairsTy currMap = currState->get<ReallocPairs>();
+  ReallocPairsTy prevMap = prevState->get<ReallocPairs>();
+
+  for (const ReallocPairsTy::value_type &Pair : prevMap) {
+    SymbolRef sym = Pair.first;
+    if (!currMap.lookup(sym))
+      return sym;
+  }
+
+  return nullptr;
+}
+
+static bool isReferenceCountingPointerDestructor(const CXXDestructorDecl *DD) {
+  if (const IdentifierInfo *II = DD->getParent()->getIdentifier()) {
+    StringRef N = II->getName();
+    if (N.contains_lower("ptr") || N.contains_lower("pointer")) {
+      if (N.contains_lower("ref") || N.contains_lower("cnt") ||
+          N.contains_lower("intrusive") || N.contains_lower("shared")) {
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
+PathDiagnosticPieceRef MallocBugVisitor::VisitNode(const ExplodedNode *N,
+                                                   BugReporterContext &BRC,
+                                                   PathSensitiveBugReport &BR) {
+  ProgramStateRef state = N->getState();
+  ProgramStateRef statePrev = N->getFirstPred()->getState();
+
+  const RefState *RSCurr = state->get<RegionState>(Sym);
+  const RefState *RSPrev = statePrev->get<RegionState>(Sym);
+
+  const Stmt *S = N->getStmtForDiagnostics();
+  // When dealing with containers, we sometimes want to give a note
+  // even if the statement is missing.
+  if (!S && (!RSCurr || RSCurr->getAllocationFamily() != AF_InnerBuffer))
+    return nullptr;
+
+  const LocationContext *CurrentLC = N->getLocationContext();
+
+  // If we find an atomic fetch_add or fetch_sub within the destructor in which
+  // the pointer was released (before the release), this is likely a destructor
+  // of a shared pointer.
+  // Because we don't model atomics, and also because we don't know that the
+  // original reference count is positive, we should not report use-after-frees
+  // on objects deleted in such destructors. This can probably be improved
+  // through better shared pointer modeling.
+  if (ReleaseDestructorLC) {
+    if (const auto *AE = dyn_cast<AtomicExpr>(S)) {
+      AtomicExpr::AtomicOp Op = AE->getOp();
+      if (Op == AtomicExpr::AO__c11_atomic_fetch_add ||
+          Op == AtomicExpr::AO__c11_atomic_fetch_sub) {
+        if (ReleaseDestructorLC == CurrentLC ||
+            ReleaseDestructorLC->isParentOf(CurrentLC)) {
+          BR.markInvalid(getTag(), S);
+        }
+      }
+    }
+  }
+
+  // FIXME: We will eventually need to handle non-statement-based events
+  // (__attribute__((cleanup))).
+
+  // Find out if this is an interesting point and what is the kind.
+  StringRef Msg;
+  std::unique_ptr<StackHintGeneratorForSymbol> StackHint = nullptr;
+  SmallString<256> Buf;
+  llvm::raw_svector_ostream OS(Buf);
+
+  if (Mode == Normal) {
+    if (isAllocated(RSCurr, RSPrev, S)) {
+      Msg = "Memory is allocated";
+      StackHint = std::make_unique<StackHintGeneratorForSymbol>(
+          Sym, "Returned allocated memory");
+    } else if (isReleased(RSCurr, RSPrev, S)) {
+      const auto Family = RSCurr->getAllocationFamily();
+      switch (Family) {
+        case AF_Alloca:
+        case AF_Malloc:
+        case AF_CXXNew:
+        case AF_CXXNewArray:
+        case AF_IfNameIndex:
+          Msg = "Memory is released";
+          StackHint = std::make_unique<StackHintGeneratorForSymbol>(
+              Sym, "Returning; memory was released");
+          break;
+        case AF_InnerBuffer: {
+          const MemRegion *ObjRegion =
+              allocation_state::getContainerObjRegion(statePrev, Sym);
+          const auto *TypedRegion = cast<TypedValueRegion>(ObjRegion);
+          QualType ObjTy = TypedRegion->getValueType();
+          OS << "Inner buffer of '" << ObjTy.getAsString() << "' ";
+
+          if (N->getLocation().getKind() == ProgramPoint::PostImplicitCallKind) {
+            OS << "deallocated by call to destructor";
+            StackHint = std::make_unique<StackHintGeneratorForSymbol>(
+                Sym, "Returning; inner buffer was deallocated");
+          } else {
+            OS << "reallocated by call to '";
+            const Stmt *S = RSCurr->getStmt();
+            if (const auto *MemCallE = dyn_cast<CXXMemberCallExpr>(S)) {
+              OS << MemCallE->getMethodDecl()->getNameAsString();
+            } else if (const auto *OpCallE = dyn_cast<CXXOperatorCallExpr>(S)) {
+              OS << OpCallE->getDirectCallee()->getNameAsString();
+            } else if (const auto *CallE = dyn_cast<CallExpr>(S)) {
+              auto &CEMgr = BRC.getStateManager().getCallEventManager();
+              CallEventRef<> Call = CEMgr.getSimpleCall(CallE, state, CurrentLC);
+              const auto *D = dyn_cast_or_null<NamedDecl>(Call->getDecl());
+              OS << (D ? D->getNameAsString() : "unknown");
+            }
+            OS << "'";
+            StackHint = std::make_unique<StackHintGeneratorForSymbol>(
+                Sym, "Returning; inner buffer was reallocated");
+          }
+          Msg = OS.str();
+          break;
+        }
+        case AF_None:
+          llvm_unreachable("Unhandled allocation family!");
+      }
+
+      // See if we're releasing memory while inlining a destructor
+      // (or one of its callees). This turns on various common
+      // false positive suppressions.
+      bool FoundAnyDestructor = false;
+      for (const LocationContext *LC = CurrentLC; LC; LC = LC->getParent()) {
+        if (const auto *DD = dyn_cast<CXXDestructorDecl>(LC->getDecl())) {
+          if (isReferenceCountingPointerDestructor(DD)) {
+            // This immediately looks like a reference-counting destructor.
+            // We're bad at guessing the original reference count of the object,
+            // so suppress the report for now.
+            BR.markInvalid(getTag(), DD);
+          } else if (!FoundAnyDestructor) {
+            assert(!ReleaseDestructorLC &&
+                   "There can be only one release point!");
+            // Suspect that it's a reference counting pointer destructor.
+            // On one of the next nodes might find out that it has atomic
+            // reference counting operations within it (see the code above),
+            // and if so, we'd conclude that it likely is a reference counting
+            // pointer destructor.
+            ReleaseDestructorLC = LC->getStackFrame();
+            // It is unlikely that releasing memory is delegated to a destructor
+            // inside a destructor of a shared pointer, because it's fairly hard
+            // to pass the information that the pointer indeed needs to be
+            // released into it. So we're only interested in the innermost
+            // destructor.
+            FoundAnyDestructor = true;
+          }
+        }
+      }
+    } else if (isRelinquished(RSCurr, RSPrev, S)) {
+      Msg = "Memory ownership is transferred";
+      StackHint = std::make_unique<StackHintGeneratorForSymbol>(Sym, "");
+    } else if (hasReallocFailed(RSCurr, RSPrev, S)) {
+      Mode = ReallocationFailed;
+      Msg = "Reallocation failed";
+      StackHint = std::make_unique<StackHintGeneratorForReallocationFailed>(
+          Sym, "Reallocation failed");
+
+      if (SymbolRef sym = findFailedReallocSymbol(state, statePrev)) {
+        // Is it possible to fail two reallocs WITHOUT testing in between?
+        assert((!FailedReallocSymbol || FailedReallocSymbol == sym) &&
+          "We only support one failed realloc at a time.");
+        BR.markInteresting(sym);
+        FailedReallocSymbol = sym;
+      }
+    }
+
+  // We are in a special mode if a reallocation failed later in the path.
+  } else if (Mode == ReallocationFailed) {
+    assert(FailedReallocSymbol && "No symbol to look for.");
+
+    // Is this is the first appearance of the reallocated symbol?
+    if (!statePrev->get<RegionState>(FailedReallocSymbol)) {
+      // We're at the reallocation point.
+      Msg = "Attempt to reallocate memory";
+      StackHint = std::make_unique<StackHintGeneratorForSymbol>(
+          Sym, "Returned reallocated memory");
+      FailedReallocSymbol = nullptr;
+      Mode = Normal;
+    }
+  }
+
+  if (Msg.empty()) {
+    assert(!StackHint);
+    return nullptr;
+  }
+
+  assert(StackHint);
+
+  // Generate the extra diagnostic.
+  PathDiagnosticLocation Pos;
+  if (!S) {
+    assert(RSCurr->getAllocationFamily() == AF_InnerBuffer);
+    auto PostImplCall = N->getLocation().getAs<PostImplicitCall>();
+    if (!PostImplCall)
+      return nullptr;
+    Pos = PathDiagnosticLocation(PostImplCall->getLocation(),
+                                 BRC.getSourceManager());
+  } else {
+    Pos = PathDiagnosticLocation(S, BRC.getSourceManager(),
+                                 N->getLocationContext());
+  }
+
+  auto P = std::make_shared<PathDiagnosticEventPiece>(Pos, Msg, true);
+  BR.addCallStackHint(P, std::move(StackHint));
+  return P;
+}
+
+void MallocChecker::printState(raw_ostream &Out, ProgramStateRef State,
+                               const char *NL, const char *Sep) const {
+
+  RegionStateTy RS = State->get<RegionState>();
+
+  if (!RS.isEmpty()) {
+    Out << Sep << "MallocChecker :" << NL;
+    for (RegionStateTy::iterator I = RS.begin(), E = RS.end(); I != E; ++I) {
+      const RefState *RefS = State->get<RegionState>(I.getKey());
+      AllocationFamily Family = RefS->getAllocationFamily();
+      Optional<MallocChecker::CheckKind> CheckKind = getCheckIfTracked(Family);
+      if (!CheckKind.hasValue())
+         CheckKind = getCheckIfTracked(Family, true);
+
+      I.getKey()->dumpToStream(Out);
+      Out << " : ";
+      I.getData().dump(Out);
+      if (CheckKind.hasValue())
+        Out << " (" << CheckNames[*CheckKind].getName() << ")";
+      Out << NL;
+    }
+  }
+}
+
+namespace clang {
+namespace ento {
+namespace allocation_state {
+
+ProgramStateRef
+markReleased(ProgramStateRef State, SymbolRef Sym, const Expr *Origin) {
+  AllocationFamily Family = AF_InnerBuffer;
+  return State->set<RegionState>(Sym, RefState::getReleased(Family, Origin));
+}
+
+} // end namespace allocation_state
+} // end namespace ento
+} // end namespace clang
+
+// Intended to be used in InnerPointerChecker to register the part of
+// MallocChecker connected to it.
+void ento::registerInnerPointerCheckerAux(CheckerManager &mgr) {
+  MallocChecker *checker = mgr.getChecker<MallocChecker>();
+  checker->ChecksEnabled[MallocChecker::CK_InnerPointerChecker] = true;
+  checker->CheckNames[MallocChecker::CK_InnerPointerChecker] =
+      mgr.getCurrentCheckerName();
+}
+
+void ento::registerDynamicMemoryModeling(CheckerManager &mgr) {
+  auto *checker = mgr.registerChecker<MallocChecker>();
+  checker->MemFunctionInfo.ShouldIncludeOwnershipAnnotatedFunctions =
+      mgr.getAnalyzerOptions().getCheckerBooleanOption(checker, "Optimistic");
+}
+
+bool ento::shouldRegisterDynamicMemoryModeling(const LangOptions &LO) {
+  return true;
+}
+
+#define REGISTER_CHECKER(name)                                                 \
+  void ento::register##name(CheckerManager &mgr) {                             \
+    MallocChecker *checker = mgr.getChecker<MallocChecker>();                  \
+    checker->ChecksEnabled[MallocChecker::CK_##name] = true;                   \
+    checker->CheckNames[MallocChecker::CK_##name] =                            \
+        mgr.getCurrentCheckerName();                                           \
+  }                                                                            \
+                                                                               \
+  bool ento::shouldRegister##name(const LangOptions &LO) { return true; }
+
+REGISTER_CHECKER(MallocChecker)
+REGISTER_CHECKER(NewDeleteChecker)
+REGISTER_CHECKER(NewDeleteLeaksChecker)
+REGISTER_CHECKER(MismatchedDeallocatorChecker)