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  1. //== ProgramState.h - Path-sensitive "State" for tracking values -*- C++ -*--=//
  2. //
  3. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4. // See https://llvm.org/LICENSE.txt for license information.
  5. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6. //
  7. //===----------------------------------------------------------------------===//
  8. //
  9. // This file defines the state of the program along the analysisa path.
  10. //
  11. //===----------------------------------------------------------------------===//
  12.  
  13. #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_PROGRAMSTATE_H
  14. #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_PROGRAMSTATE_H
  15.  
  16. #include "clang/Basic/LLVM.h"
  17. #include "clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h"
  18. #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicTypeInfo.h"
  19. #include "clang/StaticAnalyzer/Core/PathSensitive/Environment.h"
  20. #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
  21. #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
  22. #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
  23. #include "llvm/ADT/FoldingSet.h"
  24. #include "llvm/ADT/ImmutableMap.h"
  25. #include "llvm/Support/Allocator.h"
  26. #include <optional>
  27. #include <utility>
  28.  
  29. namespace llvm {
  30. class APSInt;
  31. }
  32.  
  33. namespace clang {
  34. class ASTContext;
  35.  
  36. namespace ento {
  37.  
  38. class AnalysisManager;
  39. class CallEvent;
  40. class CallEventManager;
  41.  
  42. typedef std::unique_ptr<ConstraintManager>(*ConstraintManagerCreator)(
  43.     ProgramStateManager &, ExprEngine *);
  44. typedef std::unique_ptr<StoreManager>(*StoreManagerCreator)(
  45.     ProgramStateManager &);
  46.  
  47. //===----------------------------------------------------------------------===//
  48. // ProgramStateTrait - Traits used by the Generic Data Map of a ProgramState.
  49. //===----------------------------------------------------------------------===//
  50.  
  51. template <typename T> struct ProgramStateTrait {
  52.   typedef typename T::data_type data_type;
  53.   static inline void *MakeVoidPtr(data_type D) { return (void*) D; }
  54.   static inline data_type MakeData(void *const* P) {
  55.     return P ? (data_type) *P : (data_type) 0;
  56.   }
  57. };
  58.  
  59. /// \class ProgramState
  60. /// ProgramState - This class encapsulates:
  61. ///
  62. ///    1. A mapping from expressions to values (Environment)
  63. ///    2. A mapping from locations to values (Store)
  64. ///    3. Constraints on symbolic values (GenericDataMap)
  65. ///
  66. ///  Together these represent the "abstract state" of a program.
  67. ///
  68. ///  ProgramState is intended to be used as a functional object; that is,
  69. ///  once it is created and made "persistent" in a FoldingSet, its
  70. ///  values will never change.
  71. class ProgramState : public llvm::FoldingSetNode {
  72. public:
  73.   typedef llvm::ImmutableSet<llvm::APSInt*>                IntSetTy;
  74.   typedef llvm::ImmutableMap<void*, void*>                 GenericDataMap;
  75.  
  76. private:
  77.   void operator=(const ProgramState& R) = delete;
  78.  
  79.   friend class ProgramStateManager;
  80.   friend class ExplodedGraph;
  81.   friend class ExplodedNode;
  82.   friend class NodeBuilder;
  83.  
  84.   ProgramStateManager *stateMgr;
  85.   Environment Env;           // Maps a Stmt to its current SVal.
  86.   Store store;               // Maps a location to its current value.
  87.   GenericDataMap   GDM;      // Custom data stored by a client of this class.
  88.  
  89.   // A state is infeasible if there is a contradiction among the constraints.
  90.   // An infeasible state is represented by a `nullptr`.
  91.   // In the sense of `assumeDual`, a state can have two children by adding a
  92.   // new constraint and the negation of that new constraint. A parent state is
  93.   // over-constrained if both of its children are infeasible. In the
  94.   // mathematical sense, it means that the parent is infeasible and we should
  95.   // have realized that at the moment when we have created it. However, we
  96.   // could not recognize that because of the imperfection of the underlying
  97.   // constraint solver. We say it is posteriorly over-constrained because we
  98.   // recognize that a parent is infeasible only *after* a new and more specific
  99.   // constraint and its negation are evaluated.
  100.   //
  101.   // Example:
  102.   //
  103.   // x * x = 4 and x is in the range [0, 1]
  104.   // This is an already infeasible state, but the constraint solver is not
  105.   // capable of handling sqrt, thus we don't know it yet.
  106.   //
  107.   // Then a new constraint `x = 0` is added. At this moment the constraint
  108.   // solver re-evaluates the existing constraints and realizes the
  109.   // contradiction `0 * 0 = 4`.
  110.   // We also evaluate the negated constraint `x != 0`;  the constraint solver
  111.   // deduces `x = 1` and then realizes the contradiction `1 * 1 = 4`.
  112.   // Both children are infeasible, thus the parent state is marked as
  113.   // posteriorly over-constrained. These parents are handled with special care:
  114.   // we do not allow transitions to exploded nodes with such states.
  115.   bool PosteriorlyOverconstrained = false;
  116.   // Make internal constraint solver entities friends so they can access the
  117.   // overconstrained-related functions. We want to keep this API inaccessible
  118.   // for Checkers.
  119.   friend class ConstraintManager;
  120.   bool isPosteriorlyOverconstrained() const {
  121.     return PosteriorlyOverconstrained;
  122.   }
  123.   ProgramStateRef cloneAsPosteriorlyOverconstrained() const;
  124.  
  125.   unsigned refCount;
  126.  
  127.   /// makeWithStore - Return a ProgramState with the same values as the current
  128.   ///  state with the exception of using the specified Store.
  129.   ProgramStateRef makeWithStore(const StoreRef &store) const;
  130.  
  131.   void setStore(const StoreRef &storeRef);
  132.  
  133. public:
  134.   /// This ctor is used when creating the first ProgramState object.
  135.   ProgramState(ProgramStateManager *mgr, const Environment& env,
  136.           StoreRef st, GenericDataMap gdm);
  137.  
  138.   /// Copy ctor - We must explicitly define this or else the "Next" ptr
  139.   ///  in FoldingSetNode will also get copied.
  140.   ProgramState(const ProgramState &RHS);
  141.  
  142.   ~ProgramState();
  143.  
  144.   int64_t getID() const;
  145.  
  146.   /// Return the ProgramStateManager associated with this state.
  147.   ProgramStateManager &getStateManager() const {
  148.     return *stateMgr;
  149.   }
  150.  
  151.   AnalysisManager &getAnalysisManager() const;
  152.  
  153.   /// Return the ConstraintManager.
  154.   ConstraintManager &getConstraintManager() const;
  155.  
  156.   /// getEnvironment - Return the environment associated with this state.
  157.   ///  The environment is the mapping from expressions to values.
  158.   const Environment& getEnvironment() const { return Env; }
  159.  
  160.   /// Return the store associated with this state.  The store
  161.   ///  is a mapping from locations to values.
  162.   Store getStore() const { return store; }
  163.  
  164.  
  165.   /// getGDM - Return the generic data map associated with this state.
  166.   GenericDataMap getGDM() const { return GDM; }
  167.  
  168.   void setGDM(GenericDataMap gdm) { GDM = gdm; }
  169.  
  170.   /// Profile - Profile the contents of a ProgramState object for use in a
  171.   ///  FoldingSet.  Two ProgramState objects are considered equal if they
  172.   ///  have the same Environment, Store, and GenericDataMap.
  173.   static void Profile(llvm::FoldingSetNodeID& ID, const ProgramState *V) {
  174.     V->Env.Profile(ID);
  175.     ID.AddPointer(V->store);
  176.     V->GDM.Profile(ID);
  177.     ID.AddBoolean(V->PosteriorlyOverconstrained);
  178.   }
  179.  
  180.   /// Profile - Used to profile the contents of this object for inclusion
  181.   ///  in a FoldingSet.
  182.   void Profile(llvm::FoldingSetNodeID& ID) const {
  183.     Profile(ID, this);
  184.   }
  185.  
  186.   BasicValueFactory &getBasicVals() const;
  187.   SymbolManager &getSymbolManager() const;
  188.  
  189.   //==---------------------------------------------------------------------==//
  190.   // Constraints on values.
  191.   //==---------------------------------------------------------------------==//
  192.   //
  193.   // Each ProgramState records constraints on symbolic values.  These constraints
  194.   // are managed using the ConstraintManager associated with a ProgramStateManager.
  195.   // As constraints gradually accrue on symbolic values, added constraints
  196.   // may conflict and indicate that a state is infeasible (as no real values
  197.   // could satisfy all the constraints).  This is the principal mechanism
  198.   // for modeling path-sensitivity in ExprEngine/ProgramState.
  199.   //
  200.   // Various "assume" methods form the interface for adding constraints to
  201.   // symbolic values.  A call to 'assume' indicates an assumption being placed
  202.   // on one or symbolic values.  'assume' methods take the following inputs:
  203.   //
  204.   //  (1) A ProgramState object representing the current state.
  205.   //
  206.   //  (2) The assumed constraint (which is specific to a given "assume" method).
  207.   //
  208.   //  (3) A binary value "Assumption" that indicates whether the constraint is
  209.   //      assumed to be true or false.
  210.   //
  211.   // The output of "assume*" is a new ProgramState object with the added constraints.
  212.   // If no new state is feasible, NULL is returned.
  213.   //
  214.  
  215.   /// Assumes that the value of \p cond is zero (if \p assumption is "false")
  216.   /// or non-zero (if \p assumption is "true").
  217.   ///
  218.   /// This returns a new state with the added constraint on \p cond.
  219.   /// If no new state is feasible, NULL is returned.
  220.   [[nodiscard]] ProgramStateRef assume(DefinedOrUnknownSVal cond,
  221.                                        bool assumption) const;
  222.  
  223.   /// Assumes both "true" and "false" for \p cond, and returns both
  224.   /// corresponding states (respectively).
  225.   ///
  226.   /// This is more efficient than calling assume() twice. Note that one (but not
  227.   /// both) of the returned states may be NULL.
  228.   [[nodiscard]] std::pair<ProgramStateRef, ProgramStateRef>
  229.   assume(DefinedOrUnknownSVal cond) const;
  230.  
  231.   [[nodiscard]] std::pair<ProgramStateRef, ProgramStateRef>
  232.   assumeInBoundDual(DefinedOrUnknownSVal idx, DefinedOrUnknownSVal upperBound,
  233.                     QualType IndexType = QualType()) const;
  234.  
  235.   [[nodiscard]] ProgramStateRef
  236.   assumeInBound(DefinedOrUnknownSVal idx, DefinedOrUnknownSVal upperBound,
  237.                 bool assumption, QualType IndexType = QualType()) const;
  238.  
  239.   /// Assumes that the value of \p Val is bounded with [\p From; \p To]
  240.   /// (if \p assumption is "true") or it is fully out of this range
  241.   /// (if \p assumption is "false").
  242.   ///
  243.   /// This returns a new state with the added constraint on \p cond.
  244.   /// If no new state is feasible, NULL is returned.
  245.   [[nodiscard]] ProgramStateRef assumeInclusiveRange(DefinedOrUnknownSVal Val,
  246.                                                      const llvm::APSInt &From,
  247.                                                      const llvm::APSInt &To,
  248.                                                      bool assumption) const;
  249.  
  250.   /// Assumes given range both "true" and "false" for \p Val, and returns both
  251.   /// corresponding states (respectively).
  252.   ///
  253.   /// This is more efficient than calling assume() twice. Note that one (but not
  254.   /// both) of the returned states may be NULL.
  255.   [[nodiscard]] std::pair<ProgramStateRef, ProgramStateRef>
  256.   assumeInclusiveRange(DefinedOrUnknownSVal Val, const llvm::APSInt &From,
  257.                        const llvm::APSInt &To) const;
  258.  
  259.   /// Check if the given SVal is not constrained to zero and is not
  260.   ///        a zero constant.
  261.   ConditionTruthVal isNonNull(SVal V) const;
  262.  
  263.   /// Check if the given SVal is constrained to zero or is a zero
  264.   ///        constant.
  265.   ConditionTruthVal isNull(SVal V) const;
  266.  
  267.   /// \return Whether values \p Lhs and \p Rhs are equal.
  268.   ConditionTruthVal areEqual(SVal Lhs, SVal Rhs) const;
  269.  
  270.   /// Utility method for getting regions.
  271.   LLVM_ATTRIBUTE_RETURNS_NONNULL
  272.   const VarRegion* getRegion(const VarDecl *D, const LocationContext *LC) const;
  273.  
  274.   //==---------------------------------------------------------------------==//
  275.   // Binding and retrieving values to/from the environment and symbolic store.
  276.   //==---------------------------------------------------------------------==//
  277.  
  278.   /// Create a new state by binding the value 'V' to the statement 'S' in the
  279.   /// state's environment.
  280.   [[nodiscard]] ProgramStateRef BindExpr(const Stmt *S,
  281.                                          const LocationContext *LCtx, SVal V,
  282.                                          bool Invalidate = true) const;
  283.  
  284.   [[nodiscard]] ProgramStateRef bindLoc(Loc location, SVal V,
  285.                                         const LocationContext *LCtx,
  286.                                         bool notifyChanges = true) const;
  287.  
  288.   [[nodiscard]] ProgramStateRef bindLoc(SVal location, SVal V,
  289.                                         const LocationContext *LCtx) const;
  290.  
  291.   /// Initializes the region of memory represented by \p loc with an initial
  292.   /// value. Once initialized, all values loaded from any sub-regions of that
  293.   /// region will be equal to \p V, unless overwritten later by the program.
  294.   /// This method should not be used on regions that are already initialized.
  295.   /// If you need to indicate that memory contents have suddenly become unknown
  296.   /// within a certain region of memory, consider invalidateRegions().
  297.   [[nodiscard]] ProgramStateRef
  298.   bindDefaultInitial(SVal loc, SVal V, const LocationContext *LCtx) const;
  299.  
  300.   /// Performs C++ zero-initialization procedure on the region of memory
  301.   /// represented by \p loc.
  302.   [[nodiscard]] ProgramStateRef
  303.   bindDefaultZero(SVal loc, const LocationContext *LCtx) const;
  304.  
  305.   [[nodiscard]] ProgramStateRef killBinding(Loc LV) const;
  306.  
  307.   /// Returns the state with bindings for the given regions
  308.   ///  cleared from the store.
  309.   ///
  310.   /// Optionally invalidates global regions as well.
  311.   ///
  312.   /// \param Regions the set of regions to be invalidated.
  313.   /// \param E the expression that caused the invalidation.
  314.   /// \param BlockCount The number of times the current basic block has been
  315.   //         visited.
  316.   /// \param CausesPointerEscape the flag is set to true when
  317.   ///        the invalidation entails escape of a symbol (representing a
  318.   ///        pointer). For example, due to it being passed as an argument in a
  319.   ///        call.
  320.   /// \param IS the set of invalidated symbols.
  321.   /// \param Call if non-null, the invalidated regions represent parameters to
  322.   ///        the call and should be considered directly invalidated.
  323.   /// \param ITraits information about special handling for a particular
  324.   ///        region/symbol.
  325.   [[nodiscard]] ProgramStateRef
  326.   invalidateRegions(ArrayRef<const MemRegion *> Regions, const Expr *E,
  327.                     unsigned BlockCount, const LocationContext *LCtx,
  328.                     bool CausesPointerEscape, InvalidatedSymbols *IS = nullptr,
  329.                     const CallEvent *Call = nullptr,
  330.                     RegionAndSymbolInvalidationTraits *ITraits = nullptr) const;
  331.  
  332.   [[nodiscard]] ProgramStateRef
  333.   invalidateRegions(ArrayRef<SVal> Regions, const Expr *E, unsigned BlockCount,
  334.                     const LocationContext *LCtx, bool CausesPointerEscape,
  335.                     InvalidatedSymbols *IS = nullptr,
  336.                     const CallEvent *Call = nullptr,
  337.                     RegionAndSymbolInvalidationTraits *ITraits = nullptr) const;
  338.  
  339.   /// enterStackFrame - Returns the state for entry to the given stack frame,
  340.   ///  preserving the current state.
  341.   [[nodiscard]] ProgramStateRef
  342.   enterStackFrame(const CallEvent &Call,
  343.                   const StackFrameContext *CalleeCtx) const;
  344.  
  345.   /// Return the value of 'self' if available in the given context.
  346.   SVal getSelfSVal(const LocationContext *LC) const;
  347.  
  348.   /// Get the lvalue for a base class object reference.
  349.   Loc getLValue(const CXXBaseSpecifier &BaseSpec, const SubRegion *Super) const;
  350.  
  351.   /// Get the lvalue for a base class object reference.
  352.   Loc getLValue(const CXXRecordDecl *BaseClass, const SubRegion *Super,
  353.                 bool IsVirtual) const;
  354.  
  355.   /// Get the lvalue for a variable reference.
  356.   Loc getLValue(const VarDecl *D, const LocationContext *LC) const;
  357.  
  358.   Loc getLValue(const CompoundLiteralExpr *literal,
  359.                 const LocationContext *LC) const;
  360.  
  361.   /// Get the lvalue for an ivar reference.
  362.   SVal getLValue(const ObjCIvarDecl *decl, SVal base) const;
  363.  
  364.   /// Get the lvalue for a field reference.
  365.   SVal getLValue(const FieldDecl *decl, SVal Base) const;
  366.  
  367.   /// Get the lvalue for an indirect field reference.
  368.   SVal getLValue(const IndirectFieldDecl *decl, SVal Base) const;
  369.  
  370.   /// Get the lvalue for an array index.
  371.   SVal getLValue(QualType ElementType, SVal Idx, SVal Base) const;
  372.  
  373.   /// Returns the SVal bound to the statement 'S' in the state's environment.
  374.   SVal getSVal(const Stmt *S, const LocationContext *LCtx) const;
  375.  
  376.   SVal getSValAsScalarOrLoc(const Stmt *Ex, const LocationContext *LCtx) const;
  377.  
  378.   /// Return the value bound to the specified location.
  379.   /// Returns UnknownVal() if none found.
  380.   SVal getSVal(Loc LV, QualType T = QualType()) const;
  381.  
  382.   /// Returns the "raw" SVal bound to LV before any value simplfication.
  383.   SVal getRawSVal(Loc LV, QualType T= QualType()) const;
  384.  
  385.   /// Return the value bound to the specified location.
  386.   /// Returns UnknownVal() if none found.
  387.   SVal getSVal(const MemRegion* R, QualType T = QualType()) const;
  388.  
  389.   /// Return the value bound to the specified location, assuming
  390.   /// that the value is a scalar integer or an enumeration or a pointer.
  391.   /// Returns UnknownVal() if none found or the region is not known to hold
  392.   /// a value of such type.
  393.   SVal getSValAsScalarOrLoc(const MemRegion *R) const;
  394.  
  395.   using region_iterator = const MemRegion **;
  396.  
  397.   /// Visits the symbols reachable from the given SVal using the provided
  398.   /// SymbolVisitor.
  399.   ///
  400.   /// This is a convenience API. Consider using ScanReachableSymbols class
  401.   /// directly when making multiple scans on the same state with the same
  402.   /// visitor to avoid repeated initialization cost.
  403.   /// \sa ScanReachableSymbols
  404.   bool scanReachableSymbols(SVal val, SymbolVisitor& visitor) const;
  405.  
  406.   /// Visits the symbols reachable from the regions in the given
  407.   /// MemRegions range using the provided SymbolVisitor.
  408.   bool scanReachableSymbols(llvm::iterator_range<region_iterator> Reachable,
  409.                             SymbolVisitor &visitor) const;
  410.  
  411.   template <typename CB> CB scanReachableSymbols(SVal val) const;
  412.   template <typename CB> CB
  413.   scanReachableSymbols(llvm::iterator_range<region_iterator> Reachable) const;
  414.  
  415.   //==---------------------------------------------------------------------==//
  416.   // Accessing the Generic Data Map (GDM).
  417.   //==---------------------------------------------------------------------==//
  418.  
  419.   void *const* FindGDM(void *K) const;
  420.  
  421.   template <typename T>
  422.   [[nodiscard]] ProgramStateRef
  423.   add(typename ProgramStateTrait<T>::key_type K) const;
  424.  
  425.   template <typename T>
  426.   typename ProgramStateTrait<T>::data_type
  427.   get() const {
  428.     return ProgramStateTrait<T>::MakeData(FindGDM(ProgramStateTrait<T>::GDMIndex()));
  429.   }
  430.  
  431.   template<typename T>
  432.   typename ProgramStateTrait<T>::lookup_type
  433.   get(typename ProgramStateTrait<T>::key_type key) const {
  434.     void *const* d = FindGDM(ProgramStateTrait<T>::GDMIndex());
  435.     return ProgramStateTrait<T>::Lookup(ProgramStateTrait<T>::MakeData(d), key);
  436.   }
  437.  
  438.   template <typename T>
  439.   typename ProgramStateTrait<T>::context_type get_context() const;
  440.  
  441.   template <typename T>
  442.   [[nodiscard]] ProgramStateRef
  443.   remove(typename ProgramStateTrait<T>::key_type K) const;
  444.  
  445.   template <typename T>
  446.   [[nodiscard]] ProgramStateRef
  447.   remove(typename ProgramStateTrait<T>::key_type K,
  448.          typename ProgramStateTrait<T>::context_type C) const;
  449.  
  450.   template <typename T> [[nodiscard]] ProgramStateRef remove() const;
  451.  
  452.   template <typename T>
  453.   [[nodiscard]] ProgramStateRef
  454.   set(typename ProgramStateTrait<T>::data_type D) const;
  455.  
  456.   template <typename T>
  457.   [[nodiscard]] ProgramStateRef
  458.   set(typename ProgramStateTrait<T>::key_type K,
  459.       typename ProgramStateTrait<T>::value_type E) const;
  460.  
  461.   template <typename T>
  462.   [[nodiscard]] ProgramStateRef
  463.   set(typename ProgramStateTrait<T>::key_type K,
  464.       typename ProgramStateTrait<T>::value_type E,
  465.       typename ProgramStateTrait<T>::context_type C) const;
  466.  
  467.   template<typename T>
  468.   bool contains(typename ProgramStateTrait<T>::key_type key) const {
  469.     void *const* d = FindGDM(ProgramStateTrait<T>::GDMIndex());
  470.     return ProgramStateTrait<T>::Contains(ProgramStateTrait<T>::MakeData(d), key);
  471.   }
  472.  
  473.   // Pretty-printing.
  474.   void printJson(raw_ostream &Out, const LocationContext *LCtx = nullptr,
  475.                  const char *NL = "\n", unsigned int Space = 0,
  476.                  bool IsDot = false) const;
  477.  
  478.   void printDOT(raw_ostream &Out, const LocationContext *LCtx = nullptr,
  479.                 unsigned int Space = 0) const;
  480.  
  481.   void dump() const;
  482.  
  483. private:
  484.   friend void ProgramStateRetain(const ProgramState *state);
  485.   friend void ProgramStateRelease(const ProgramState *state);
  486.  
  487.   /// \sa invalidateValues()
  488.   /// \sa invalidateRegions()
  489.   ProgramStateRef
  490.   invalidateRegionsImpl(ArrayRef<SVal> Values,
  491.                         const Expr *E, unsigned BlockCount,
  492.                         const LocationContext *LCtx,
  493.                         bool ResultsInSymbolEscape,
  494.                         InvalidatedSymbols *IS,
  495.                         RegionAndSymbolInvalidationTraits *HTraits,
  496.                         const CallEvent *Call) const;
  497. };
  498.  
  499. //===----------------------------------------------------------------------===//
  500. // ProgramStateManager - Factory object for ProgramStates.
  501. //===----------------------------------------------------------------------===//
  502.  
  503. class ProgramStateManager {
  504.   friend class ProgramState;
  505.   friend void ProgramStateRelease(const ProgramState *state);
  506. private:
  507.   /// Eng - The ExprEngine that owns this state manager.
  508.   ExprEngine *Eng; /* Can be null. */
  509.  
  510.   EnvironmentManager                   EnvMgr;
  511.   std::unique_ptr<StoreManager>        StoreMgr;
  512.   std::unique_ptr<ConstraintManager>   ConstraintMgr;
  513.  
  514.   ProgramState::GenericDataMap::Factory     GDMFactory;
  515.  
  516.   typedef llvm::DenseMap<void*,std::pair<void*,void (*)(void*)> > GDMContextsTy;
  517.   GDMContextsTy GDMContexts;
  518.  
  519.   /// StateSet - FoldingSet containing all the states created for analyzing
  520.   ///  a particular function.  This is used to unique states.
  521.   llvm::FoldingSet<ProgramState> StateSet;
  522.  
  523.   /// Object that manages the data for all created SVals.
  524.   std::unique_ptr<SValBuilder> svalBuilder;
  525.  
  526.   /// Manages memory for created CallEvents.
  527.   std::unique_ptr<CallEventManager> CallEventMgr;
  528.  
  529.   /// A BumpPtrAllocator to allocate states.
  530.   llvm::BumpPtrAllocator &Alloc;
  531.  
  532.   /// A vector of ProgramStates that we can reuse.
  533.   std::vector<ProgramState *> freeStates;
  534.  
  535. public:
  536.   ProgramStateManager(ASTContext &Ctx,
  537.                  StoreManagerCreator CreateStoreManager,
  538.                  ConstraintManagerCreator CreateConstraintManager,
  539.                  llvm::BumpPtrAllocator& alloc,
  540.                  ExprEngine *expreng);
  541.  
  542.   ~ProgramStateManager();
  543.  
  544.   ProgramStateRef getInitialState(const LocationContext *InitLoc);
  545.  
  546.   ASTContext &getContext() { return svalBuilder->getContext(); }
  547.   const ASTContext &getContext() const { return svalBuilder->getContext(); }
  548.  
  549.   BasicValueFactory &getBasicVals() {
  550.     return svalBuilder->getBasicValueFactory();
  551.   }
  552.  
  553.   SValBuilder &getSValBuilder() {
  554.     return *svalBuilder;
  555.   }
  556.  
  557.   const SValBuilder &getSValBuilder() const {
  558.     return *svalBuilder;
  559.   }
  560.  
  561.   SymbolManager &getSymbolManager() {
  562.     return svalBuilder->getSymbolManager();
  563.   }
  564.   const SymbolManager &getSymbolManager() const {
  565.     return svalBuilder->getSymbolManager();
  566.   }
  567.  
  568.   llvm::BumpPtrAllocator& getAllocator() { return Alloc; }
  569.  
  570.   MemRegionManager& getRegionManager() {
  571.     return svalBuilder->getRegionManager();
  572.   }
  573.   const MemRegionManager &getRegionManager() const {
  574.     return svalBuilder->getRegionManager();
  575.   }
  576.  
  577.   CallEventManager &getCallEventManager() { return *CallEventMgr; }
  578.  
  579.   StoreManager &getStoreManager() { return *StoreMgr; }
  580.   ConstraintManager &getConstraintManager() { return *ConstraintMgr; }
  581.   ExprEngine &getOwningEngine() { return *Eng; }
  582.  
  583.   ProgramStateRef
  584.   removeDeadBindingsFromEnvironmentAndStore(ProgramStateRef St,
  585.                                             const StackFrameContext *LCtx,
  586.                                             SymbolReaper &SymReaper);
  587.  
  588. public:
  589.  
  590.   SVal ArrayToPointer(Loc Array, QualType ElementTy) {
  591.     return StoreMgr->ArrayToPointer(Array, ElementTy);
  592.   }
  593.  
  594.   // Methods that manipulate the GDM.
  595.   ProgramStateRef addGDM(ProgramStateRef St, void *Key, void *Data);
  596.   ProgramStateRef removeGDM(ProgramStateRef state, void *Key);
  597.  
  598.   // Methods that query & manipulate the Store.
  599.  
  600.   void iterBindings(ProgramStateRef state, StoreManager::BindingsHandler& F) {
  601.     StoreMgr->iterBindings(state->getStore(), F);
  602.   }
  603.  
  604.   ProgramStateRef getPersistentState(ProgramState &Impl);
  605.   ProgramStateRef getPersistentStateWithGDM(ProgramStateRef FromState,
  606.                                            ProgramStateRef GDMState);
  607.  
  608.   bool haveEqualConstraints(ProgramStateRef S1, ProgramStateRef S2) const {
  609.     return ConstraintMgr->haveEqualConstraints(S1, S2);
  610.   }
  611.  
  612.   bool haveEqualEnvironments(ProgramStateRef S1, ProgramStateRef S2) const {
  613.     return S1->Env == S2->Env;
  614.   }
  615.  
  616.   bool haveEqualStores(ProgramStateRef S1, ProgramStateRef S2) const {
  617.     return S1->store == S2->store;
  618.   }
  619.  
  620.   //==---------------------------------------------------------------------==//
  621.   // Generic Data Map methods.
  622.   //==---------------------------------------------------------------------==//
  623.   //
  624.   // ProgramStateManager and ProgramState support a "generic data map" that allows
  625.   // different clients of ProgramState objects to embed arbitrary data within a
  626.   // ProgramState object.  The generic data map is essentially an immutable map
  627.   // from a "tag" (that acts as the "key" for a client) and opaque values.
  628.   // Tags/keys and values are simply void* values.  The typical way that clients
  629.   // generate unique tags are by taking the address of a static variable.
  630.   // Clients are responsible for ensuring that data values referred to by a
  631.   // the data pointer are immutable (and thus are essentially purely functional
  632.   // data).
  633.   //
  634.   // The templated methods below use the ProgramStateTrait<T> class
  635.   // to resolve keys into the GDM and to return data values to clients.
  636.   //
  637.  
  638.   // Trait based GDM dispatch.
  639.   template <typename T>
  640.   ProgramStateRef set(ProgramStateRef st, typename ProgramStateTrait<T>::data_type D) {
  641.     return addGDM(st, ProgramStateTrait<T>::GDMIndex(),
  642.                   ProgramStateTrait<T>::MakeVoidPtr(D));
  643.   }
  644.  
  645.   template<typename T>
  646.   ProgramStateRef set(ProgramStateRef st,
  647.                      typename ProgramStateTrait<T>::key_type K,
  648.                      typename ProgramStateTrait<T>::value_type V,
  649.                      typename ProgramStateTrait<T>::context_type C) {
  650.  
  651.     return addGDM(st, ProgramStateTrait<T>::GDMIndex(),
  652.      ProgramStateTrait<T>::MakeVoidPtr(ProgramStateTrait<T>::Set(st->get<T>(), K, V, C)));
  653.   }
  654.  
  655.   template <typename T>
  656.   ProgramStateRef add(ProgramStateRef st,
  657.                      typename ProgramStateTrait<T>::key_type K,
  658.                      typename ProgramStateTrait<T>::context_type C) {
  659.     return addGDM(st, ProgramStateTrait<T>::GDMIndex(),
  660.         ProgramStateTrait<T>::MakeVoidPtr(ProgramStateTrait<T>::Add(st->get<T>(), K, C)));
  661.   }
  662.  
  663.   template <typename T>
  664.   ProgramStateRef remove(ProgramStateRef st,
  665.                         typename ProgramStateTrait<T>::key_type K,
  666.                         typename ProgramStateTrait<T>::context_type C) {
  667.  
  668.     return addGDM(st, ProgramStateTrait<T>::GDMIndex(),
  669.      ProgramStateTrait<T>::MakeVoidPtr(ProgramStateTrait<T>::Remove(st->get<T>(), K, C)));
  670.   }
  671.  
  672.   template <typename T>
  673.   ProgramStateRef remove(ProgramStateRef st) {
  674.     return removeGDM(st, ProgramStateTrait<T>::GDMIndex());
  675.   }
  676.  
  677.   void *FindGDMContext(void *index,
  678.                        void *(*CreateContext)(llvm::BumpPtrAllocator&),
  679.                        void  (*DeleteContext)(void*));
  680.  
  681.   template <typename T>
  682.   typename ProgramStateTrait<T>::context_type get_context() {
  683.     void *p = FindGDMContext(ProgramStateTrait<T>::GDMIndex(),
  684.                              ProgramStateTrait<T>::CreateContext,
  685.                              ProgramStateTrait<T>::DeleteContext);
  686.  
  687.     return ProgramStateTrait<T>::MakeContext(p);
  688.   }
  689. };
  690.  
  691.  
  692. //===----------------------------------------------------------------------===//
  693. // Out-of-line method definitions for ProgramState.
  694. //===----------------------------------------------------------------------===//
  695.  
  696. inline ConstraintManager &ProgramState::getConstraintManager() const {
  697.   return stateMgr->getConstraintManager();
  698. }
  699.  
  700. inline const VarRegion* ProgramState::getRegion(const VarDecl *D,
  701.                                                 const LocationContext *LC) const
  702. {
  703.   return getStateManager().getRegionManager().getVarRegion(D, LC);
  704. }
  705.  
  706. inline ProgramStateRef ProgramState::assume(DefinedOrUnknownSVal Cond,
  707.                                       bool Assumption) const {
  708.   if (Cond.isUnknown())
  709.     return this;
  710.  
  711.   return getStateManager().ConstraintMgr
  712.       ->assume(this, Cond.castAs<DefinedSVal>(), Assumption);
  713. }
  714.  
  715. inline std::pair<ProgramStateRef , ProgramStateRef >
  716. ProgramState::assume(DefinedOrUnknownSVal Cond) const {
  717.   if (Cond.isUnknown())
  718.     return std::make_pair(this, this);
  719.  
  720.   return getStateManager().ConstraintMgr
  721.       ->assumeDual(this, Cond.castAs<DefinedSVal>());
  722. }
  723.  
  724. inline ProgramStateRef ProgramState::assumeInclusiveRange(
  725.     DefinedOrUnknownSVal Val, const llvm::APSInt &From, const llvm::APSInt &To,
  726.     bool Assumption) const {
  727.   if (Val.isUnknown())
  728.     return this;
  729.  
  730.   assert(isa<NonLoc>(Val) && "Only NonLocs are supported!");
  731.  
  732.   return getStateManager().ConstraintMgr->assumeInclusiveRange(
  733.       this, Val.castAs<NonLoc>(), From, To, Assumption);
  734. }
  735.  
  736. inline std::pair<ProgramStateRef, ProgramStateRef>
  737. ProgramState::assumeInclusiveRange(DefinedOrUnknownSVal Val,
  738.                                    const llvm::APSInt &From,
  739.                                    const llvm::APSInt &To) const {
  740.   if (Val.isUnknown())
  741.     return std::make_pair(this, this);
  742.  
  743.   assert(isa<NonLoc>(Val) && "Only NonLocs are supported!");
  744.  
  745.   return getStateManager().ConstraintMgr->assumeInclusiveRangeDual(
  746.       this, Val.castAs<NonLoc>(), From, To);
  747. }
  748.  
  749. inline ProgramStateRef ProgramState::bindLoc(SVal LV, SVal V, const LocationContext *LCtx) const {
  750.   if (std::optional<Loc> L = LV.getAs<Loc>())
  751.     return bindLoc(*L, V, LCtx);
  752.   return this;
  753. }
  754.  
  755. inline Loc ProgramState::getLValue(const CXXBaseSpecifier &BaseSpec,
  756.                                    const SubRegion *Super) const {
  757.   const auto *Base = BaseSpec.getType()->getAsCXXRecordDecl();
  758.   return loc::MemRegionVal(
  759.            getStateManager().getRegionManager().getCXXBaseObjectRegion(
  760.                                             Base, Super, BaseSpec.isVirtual()));
  761. }
  762.  
  763. inline Loc ProgramState::getLValue(const CXXRecordDecl *BaseClass,
  764.                                    const SubRegion *Super,
  765.                                    bool IsVirtual) const {
  766.   return loc::MemRegionVal(
  767.            getStateManager().getRegionManager().getCXXBaseObjectRegion(
  768.                                                   BaseClass, Super, IsVirtual));
  769. }
  770.  
  771. inline Loc ProgramState::getLValue(const VarDecl *VD,
  772.                                const LocationContext *LC) const {
  773.   return getStateManager().StoreMgr->getLValueVar(VD, LC);
  774. }
  775.  
  776. inline Loc ProgramState::getLValue(const CompoundLiteralExpr *literal,
  777.                                const LocationContext *LC) const {
  778.   return getStateManager().StoreMgr->getLValueCompoundLiteral(literal, LC);
  779. }
  780.  
  781. inline SVal ProgramState::getLValue(const ObjCIvarDecl *D, SVal Base) const {
  782.   return getStateManager().StoreMgr->getLValueIvar(D, Base);
  783. }
  784.  
  785. inline SVal ProgramState::getLValue(const FieldDecl *D, SVal Base) const {
  786.   return getStateManager().StoreMgr->getLValueField(D, Base);
  787. }
  788.  
  789. inline SVal ProgramState::getLValue(const IndirectFieldDecl *D,
  790.                                     SVal Base) const {
  791.   StoreManager &SM = *getStateManager().StoreMgr;
  792.   for (const auto *I : D->chain()) {
  793.     Base = SM.getLValueField(cast<FieldDecl>(I), Base);
  794.   }
  795.  
  796.   return Base;
  797. }
  798.  
  799. inline SVal ProgramState::getLValue(QualType ElementType, SVal Idx, SVal Base) const{
  800.   if (std::optional<NonLoc> N = Idx.getAs<NonLoc>())
  801.     return getStateManager().StoreMgr->getLValueElement(ElementType, *N, Base);
  802.   return UnknownVal();
  803. }
  804.  
  805. inline SVal ProgramState::getSVal(const Stmt *Ex,
  806.                                   const LocationContext *LCtx) const{
  807.   return Env.getSVal(EnvironmentEntry(Ex, LCtx),
  808.                      *getStateManager().svalBuilder);
  809. }
  810.  
  811. inline SVal
  812. ProgramState::getSValAsScalarOrLoc(const Stmt *S,
  813.                                    const LocationContext *LCtx) const {
  814.   if (const Expr *Ex = dyn_cast<Expr>(S)) {
  815.     QualType T = Ex->getType();
  816.     if (Ex->isGLValue() || Loc::isLocType(T) ||
  817.         T->isIntegralOrEnumerationType())
  818.       return getSVal(S, LCtx);
  819.   }
  820.  
  821.   return UnknownVal();
  822. }
  823.  
  824. inline SVal ProgramState::getRawSVal(Loc LV, QualType T) const {
  825.   return getStateManager().StoreMgr->getBinding(getStore(), LV, T);
  826. }
  827.  
  828. inline SVal ProgramState::getSVal(const MemRegion* R, QualType T) const {
  829.   return getStateManager().StoreMgr->getBinding(getStore(),
  830.                                                 loc::MemRegionVal(R),
  831.                                                 T);
  832. }
  833.  
  834. inline BasicValueFactory &ProgramState::getBasicVals() const {
  835.   return getStateManager().getBasicVals();
  836. }
  837.  
  838. inline SymbolManager &ProgramState::getSymbolManager() const {
  839.   return getStateManager().getSymbolManager();
  840. }
  841.  
  842. template<typename T>
  843. ProgramStateRef ProgramState::add(typename ProgramStateTrait<T>::key_type K) const {
  844.   return getStateManager().add<T>(this, K, get_context<T>());
  845. }
  846.  
  847. template <typename T>
  848. typename ProgramStateTrait<T>::context_type ProgramState::get_context() const {
  849.   return getStateManager().get_context<T>();
  850. }
  851.  
  852. template<typename T>
  853. ProgramStateRef ProgramState::remove(typename ProgramStateTrait<T>::key_type K) const {
  854.   return getStateManager().remove<T>(this, K, get_context<T>());
  855. }
  856.  
  857. template<typename T>
  858. ProgramStateRef ProgramState::remove(typename ProgramStateTrait<T>::key_type K,
  859.                                typename ProgramStateTrait<T>::context_type C) const {
  860.   return getStateManager().remove<T>(this, K, C);
  861. }
  862.  
  863. template <typename T>
  864. ProgramStateRef ProgramState::remove() const {
  865.   return getStateManager().remove<T>(this);
  866. }
  867.  
  868. template<typename T>
  869. ProgramStateRef ProgramState::set(typename ProgramStateTrait<T>::data_type D) const {
  870.   return getStateManager().set<T>(this, D);
  871. }
  872.  
  873. template<typename T>
  874. ProgramStateRef ProgramState::set(typename ProgramStateTrait<T>::key_type K,
  875.                             typename ProgramStateTrait<T>::value_type E) const {
  876.   return getStateManager().set<T>(this, K, E, get_context<T>());
  877. }
  878.  
  879. template<typename T>
  880. ProgramStateRef ProgramState::set(typename ProgramStateTrait<T>::key_type K,
  881.                             typename ProgramStateTrait<T>::value_type E,
  882.                             typename ProgramStateTrait<T>::context_type C) const {
  883.   return getStateManager().set<T>(this, K, E, C);
  884. }
  885.  
  886. template <typename CB>
  887. CB ProgramState::scanReachableSymbols(SVal val) const {
  888.   CB cb(this);
  889.   scanReachableSymbols(val, cb);
  890.   return cb;
  891. }
  892.  
  893. template <typename CB>
  894. CB ProgramState::scanReachableSymbols(
  895.     llvm::iterator_range<region_iterator> Reachable) const {
  896.   CB cb(this);
  897.   scanReachableSymbols(Reachable, cb);
  898.   return cb;
  899. }
  900.  
  901. /// \class ScanReachableSymbols
  902. /// A utility class that visits the reachable symbols using a custom
  903. /// SymbolVisitor. Terminates recursive traversal when the visitor function
  904. /// returns false.
  905. class ScanReachableSymbols {
  906.   typedef llvm::DenseSet<const void*> VisitedItems;
  907.  
  908.   VisitedItems visited;
  909.   ProgramStateRef state;
  910.   SymbolVisitor &visitor;
  911. public:
  912.   ScanReachableSymbols(ProgramStateRef st, SymbolVisitor &v)
  913.       : state(std::move(st)), visitor(v) {}
  914.  
  915.   bool scan(nonloc::LazyCompoundVal val);
  916.   bool scan(nonloc::CompoundVal val);
  917.   bool scan(SVal val);
  918.   bool scan(const MemRegion *R);
  919.   bool scan(const SymExpr *sym);
  920. };
  921.  
  922. } // end ento namespace
  923.  
  924. } // end clang namespace
  925.  
  926. #endif
  927.