path: root/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h

//===-- ExprEngine.h - Path-Sensitive Expression-Level Dataflow ---*- C++ -*-=//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines a meta-engine for path-sensitive dataflow analysis that
//  is built on CoreEngine, but provides the boilerplate to execute transfer
//  functions and build the ExplodedGraph at the expression level.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_GR_EXPRENGINE
#define LLVM_CLANG_GR_EXPRENGINE

#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/AST/Expr.h"
#include "clang/AST/Type.h"

namespace clang {

class AnalysisDeclContextManager;
class CXXCatchStmt;
class CXXConstructExpr;
class CXXDeleteExpr;
class CXXNewExpr;
class CXXTemporaryObjectExpr;
class CXXThisExpr;
class MaterializeTemporaryExpr;
class ObjCAtSynchronizedStmt;
class ObjCForCollectionStmt;
  
namespace ento {

class AnalysisManager;
class CallOrObjCMessage;
class ObjCMessage;

class ExprEngine : public SubEngine {
  AnalysisManager &AMgr;
  
  AnalysisDeclContextManager &AnalysisDeclContexts;

  CoreEngine Engine;

  /// G - the simulation graph.
  ExplodedGraph& G;

  /// StateMgr - Object that manages the data for all created states.
  ProgramStateManager StateMgr;

  /// SymMgr - Object that manages the symbol information.
  SymbolManager& SymMgr;

  /// svalBuilder - SValBuilder object that creates SVals from expressions.
  SValBuilder &svalBuilder;

  /// EntryNode - The immediate predecessor node.
  ExplodedNode *EntryNode;

  /// CleanedState - The state for EntryNode "cleaned" of all dead
  ///  variables and symbols (as determined by a liveness analysis).
  ProgramStateRef CleanedState;

  /// currentStmt - The current block-level statement.
  const Stmt *currentStmt;
  unsigned int currentStmtIdx;
  const NodeBuilderContext *currentBuilderContext;

  /// Obj-C Class Identifiers.
  IdentifierInfo* NSExceptionII;

  /// Obj-C Selectors.
  Selector* NSExceptionInstanceRaiseSelectors;
  Selector RaiseSel;
  
  /// Whether or not GC is enabled in this analysis.
  bool ObjCGCEnabled;

  /// The BugReporter associated with this engine.  It is important that
  ///  this object be placed at the very end of member variables so that its
  ///  destructor is called before the rest of the ExprEngine is destroyed.
  GRBugReporter BR;

public:
  ExprEngine(AnalysisManager &mgr, bool gcEnabled,
             SetOfConstDecls *VisitedCallees,
             FunctionSummariesTy *FS);

  ~ExprEngine();

  /// Returns true if there is still simulation state on the worklist.
  bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
    return Engine.ExecuteWorkList(L, Steps, 0);
  }

  /// Execute the work list with an initial state. Nodes that reaches the exit
  /// of the function are added into the Dst set, which represent the exit
  /// state of the function call. Returns true if there is still simulation
  /// state on the worklist.
  bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps,
                                       ProgramStateRef InitState, 
                                       ExplodedNodeSet &Dst) {
    return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst);
  }

  /// getContext - Return the ASTContext associated with this analysis.
  ASTContext &getContext() const { return AMgr.getASTContext(); }

  virtual AnalysisManager &getAnalysisManager() { return AMgr; }

  CheckerManager &getCheckerManager() const {
    return *AMgr.getCheckerManager();
  }

  SValBuilder &getSValBuilder() { return svalBuilder; }

  BugReporter& getBugReporter() { return BR; }

  const NodeBuilderContext &getBuilderContext() {
    assert(currentBuilderContext);
    return *currentBuilderContext;
  }

  bool isObjCGCEnabled() { return ObjCGCEnabled; }

  const Stmt *getStmt() const;

  void GenerateAutoTransition(ExplodedNode *N);
  void enqueueEndOfPath(ExplodedNodeSet &S);
  void GenerateCallExitNode(ExplodedNode *N);

  /// ViewGraph - Visualize the ExplodedGraph created by executing the
  ///  simulation.
  void ViewGraph(bool trim = false);

  void ViewGraph(ExplodedNode** Beg, ExplodedNode** End);

  /// getInitialState - Return the initial state used for the root vertex
  ///  in the ExplodedGraph.
  ProgramStateRef getInitialState(const LocationContext *InitLoc);

  ExplodedGraph& getGraph() { return G; }
  const ExplodedGraph& getGraph() const { return G; }

  /// \brief Run the analyzer's garbage collection - remove dead symbols and
  /// bindings.
  ///
  /// \param Node - The predecessor node, from which the processing should 
  /// start.
  /// \param Out - The returned set of output nodes.
  /// \param ReferenceStmt - Run garbage collection using the symbols, 
  /// which are live before the given statement.
  /// \param LC - The location context of the ReferenceStmt.
  /// \param DiagnosticStmt - the statement used to associate the diagnostic 
  /// message, if any warnings should occur while removing the dead (leaks 
  /// are usually reported here).
  /// \param K - In some cases it is possible to use PreStmt kind. (Do 
  /// not use it unless you know what you are doing.) 
  void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
            const Stmt *ReferenceStmt, const LocationContext *LC,
            const Stmt *DiagnosticStmt,
            ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind);

  /// processCFGElement - Called by CoreEngine. Used to generate new successor
  ///  nodes by processing the 'effects' of a CFG element.
  void processCFGElement(const CFGElement E, ExplodedNode *Pred,
                         unsigned StmtIdx, NodeBuilderContext *Ctx);

  void ProcessStmt(const CFGStmt S, ExplodedNode *Pred);

  void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);

  void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);

  void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 
                               ExplodedNode *Pred, ExplodedNodeSet &Dst);
  void ProcessBaseDtor(const CFGBaseDtor D,
                       ExplodedNode *Pred, ExplodedNodeSet &Dst);
  void ProcessMemberDtor(const CFGMemberDtor D,
                         ExplodedNode *Pred, ExplodedNodeSet &Dst);
  void ProcessTemporaryDtor(const CFGTemporaryDtor D, 
                            ExplodedNode *Pred, ExplodedNodeSet &Dst);

  /// Called by CoreEngine when processing the entrance of a CFGBlock.
  virtual void processCFGBlockEntrance(const BlockEdge &L,
                                       NodeBuilderWithSinks &nodeBuilder);
  
  /// ProcessBranch - Called by CoreEngine.  Used to generate successor
  ///  nodes by processing the 'effects' of a branch condition.
  void processBranch(const Stmt *Condition, const Stmt *Term, 
                     NodeBuilderContext& BuilderCtx,
                     ExplodedNode *Pred,
                     ExplodedNodeSet &Dst,
                     const CFGBlock *DstT,
                     const CFGBlock *DstF);

  /// processIndirectGoto - Called by CoreEngine.  Used to generate successor
  ///  nodes by processing the 'effects' of a computed goto jump.
  void processIndirectGoto(IndirectGotoNodeBuilder& builder);

  /// ProcessSwitch - Called by CoreEngine.  Used to generate successor
  ///  nodes by processing the 'effects' of a switch statement.
  void processSwitch(SwitchNodeBuilder& builder);

  /// ProcessEndPath - Called by CoreEngine.  Used to generate end-of-path
  ///  nodes when the control reaches the end of a function.
  void processEndOfFunction(NodeBuilderContext& BC);

  /// Generate the entry node of the callee.
  void processCallEnter(CallEnter CE, ExplodedNode *Pred);

  /// Generate the sequence of nodes that simulate the call exit and the post
  /// visit for CallExpr.
  void processCallExit(ExplodedNode *Pred);

  /// Called by CoreEngine when the analysis worklist has terminated.
  void processEndWorklist(bool hasWorkRemaining);

  /// evalAssume - Callback function invoked by the ConstraintManager when
  ///  making assumptions about state values.
  ProgramStateRef processAssume(ProgramStateRef state, SVal cond,bool assumption);

  /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a
  ///  region change should trigger a processRegionChanges update.
  bool wantsRegionChangeUpdate(ProgramStateRef state);

  /// processRegionChanges - Called by ProgramStateManager whenever a change is made
  ///  to the store. Used to update checkers that track region values.
  ProgramStateRef 
  processRegionChanges(ProgramStateRef state,
                       const StoreManager::InvalidatedSymbols *invalidated,
                       ArrayRef<const MemRegion *> ExplicitRegions,
                       ArrayRef<const MemRegion *> Regions,
                       const CallOrObjCMessage *Call);

  /// printState - Called by ProgramStateManager to print checker-specific data.
  void printState(raw_ostream &Out, ProgramStateRef State,
                  const char *NL, const char *Sep);

  virtual ProgramStateManager& getStateManager() { return StateMgr; }

  StoreManager& getStoreManager() { return StateMgr.getStoreManager(); }

  ConstraintManager& getConstraintManager() {
    return StateMgr.getConstraintManager();
  }

  // FIXME: Remove when we migrate over to just using SValBuilder.
  BasicValueFactory& getBasicVals() {
    return