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/AST/Expr.h"
#include "clang/AST/Type.h"
#include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.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/PathSensitive/SubEngine.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 CallEvent;
class SimpleCall;
class CXXConstructorCall;

class ExprEngine : public SubEngine {
public:
  /// The modes of inlining, which override the default analysis-wide settings.
  enum InliningModes {
    /// Follow the default settings for inlining callees.
    Inline_Regular = 0,
    /// Do minimal inlining of callees.
    Inline_Minimal = 0x1
  };

private:
  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;

  unsigned int currStmtIdx;
  const NodeBuilderContext *currBldrCtx;
  
  /// Helper object to determine if an Objective-C message expression
  /// implicitly never returns.
  ObjCNoReturn ObjCNoRet;
  
  /// 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;

  /// The functions which have been analyzed through inlining. This is owned by
  /// AnalysisConsumer. It can be null.
  SetOfConstDecls *VisitedCallees;

  /// The flag, which specifies the mode of inlining for the engine.
  InliningModes HowToInline;

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

  ~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(currBldrCtx);
    return *currBldrCtx;
  }

  bool isObjCGCEnabled() { return ObjCGCEnabled; }

  const Stmt *getStmt() const;

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

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

  /// Visualize a trimmed ExplodedGraph that only contains paths to the given
  /// nodes.
  void ViewGraph(ArrayRef<const ExplodedNode*> Nodes);

  /// 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 from the state.
  ///
  /// Checkers can participate in this process with two callbacks:
  /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation
  /// class for more information.
  ///
  /// \param Node The predecessor node, from which the processing should start.
  /// \param Out The returned set of output nodes.
  /// \param ReferenceStmt The statement which is about to be processed.
  ///        Everything needed for this statement should be considered live.
  ///        A null statement means that everything in child LocationContexts
  ///        is dead.
  /// \param LC The location context of the \p ReferenceStmt. A null location
  ///        context means that we have reached the end of analysis and that
  ///        all statements and local variables should be considered dead.
  /// \param DiagnosticStmt Used as a location for any warnings that should
  ///        occur while removing the dead (e.g. leaks). By default, the
  ///        \p ReferenceStmt is used.
  /// \param K Denotes whether this is a pre- or post-statement purge. This
  ///        must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an
  ///        entire location context is being cleared, in which case the
  ///        \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise,
  ///        it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default)
  ///        and \p ReferenceStmt must be valid (non-null).
  void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
            const Stmt *ReferenceStmt, const LocationContext *LC,
            const Stmt *DiagnosticStmt = 0,
            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,
                                       ExplodedNode *Pred);
  
  /// 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);

  /// Called by CoreEngine.  Used to processing branching behavior
  /// at static initalizers.
  void processStaticInitializer(const DeclStmt *DS,
                                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);

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

  /// Re