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

//===- CallEvent.h - Wrapper for all function and method calls ----*- C++ -*--//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file This file defines CallEvent and its subclasses, which represent path-
/// sensitive instances of different kinds of function and method calls
/// (C, C++, and Objective-C).
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_STATICANALYZER_PATHSENSITIVE_CALL
#define LLVM_CLANG_STATICANALYZER_PATHSENSITIVE_CALL

#include "clang/AST/DeclCXX.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ExprObjC.h"
#include "clang/Analysis/AnalysisContext.h"
#include "clang/Basic/SourceManager.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
#include "llvm/ADT/PointerIntPair.h"

namespace clang {
class ProgramPoint;
class ProgramPointTag;

namespace ento {

enum CallEventKind {
  CE_Function,
  CE_Block,
  CE_BEG_SIMPLE_CALLS = CE_Function,
  CE_END_SIMPLE_CALLS = CE_Block,
  CE_CXXMember,
  CE_CXXMemberOperator,
  CE_CXXDestructor,
  CE_BEG_CXX_INSTANCE_CALLS = CE_CXXMember,
  CE_END_CXX_INSTANCE_CALLS = CE_CXXDestructor,
  CE_CXXConstructor,
  CE_CXXAllocator,
  CE_BEG_FUNCTION_CALLS = CE_Function,
  CE_END_FUNCTION_CALLS = CE_CXXAllocator,
  CE_ObjCMessage
};

class CallEvent;
class CallEventManager;

template<typename T = CallEvent>
class CallEventRef : public IntrusiveRefCntPtr<const T> {
public:
  CallEventRef(const T *Call) : IntrusiveRefCntPtr<const T>(Call) {}
  CallEventRef(const CallEventRef &Orig) : IntrusiveRefCntPtr<const T>(Orig) {}

  CallEventRef<T> cloneWithState(ProgramStateRef State) const {
    return this->getPtr()->template cloneWithState<T>(State);
  }

  // Allow implicit conversions to a superclass type, since CallEventRef
  // behaves like a pointer-to-const.
  template <typename SuperT>
  operator CallEventRef<SuperT> () const {
    return this->getPtr();
  }
};

/// \class RuntimeDefinition 
/// \brief Defines the runtime definition of the called function.
/// 
/// Encapsulates the information we have about which Decl will be used 
/// when the call is executed on the given path. When dealing with dynamic
/// dispatch, the information is based on DynamicTypeInfo and might not be 
/// precise.
class RuntimeDefinition {
  /// The Declaration of the function which could be called at runtime.
  /// NULL if not available.
  const Decl *D;

  /// The region representing an object (ObjC/C++) on which the method is
  /// called. With dynamic dispatch, the method definition depends on the
  /// runtime type of this object. NULL when the DynamicTypeInfo is
  /// precise.
  const MemRegion *R;

public:
  RuntimeDefinition(): D(0), R(0) {}
  RuntimeDefinition(const Decl *InD): D(InD), R(0) {}
  RuntimeDefinition(const Decl *InD, const MemRegion *InR): D(InD), R(InR) {}
  const Decl *getDecl() { return D; }
    
  /// \brief Check if the definition we have is precise. 
  /// If not, it is possible that the call dispatches to another definition at 
  /// execution time.
  bool mayHaveOtherDefinitions() { return R != 0; }
  
  /// When other definitions are possible, returns the region whose runtime type 
  /// determines the method definition.
  const MemRegion *getDispatchRegion() { return R; }
};

/// \brief Represents an abstract call to a function or method along a
/// particular path.
///
/// CallEvents are created through the factory methods of CallEventManager.
///
/// CallEvents should always be cheap to create and destroy. In order for
/// CallEventManager to be able to re-use CallEvent-sized memory blocks,
/// subclasses of CallEvent may not add any data members to the base class.
/// Use the "Data" and "Location" fields instead.
class CallEvent {
public:
  typedef CallEventKind Kind;

private:
  ProgramStateRef State;
  const LocationContext *LCtx;
  llvm::PointerUnion<const Expr *, const Decl *> Origin;

  void operator=(const CallEvent &) LLVM_DELETED_FUNCTION;

protected:
  // This is user data for subclasses.
  const void *Data;

  // This is user data for subclasses.
  // This should come right before RefCount, so that the two fields can be
  // packed together on LP64 platforms.
  SourceLocation Location;

private:
  mutable unsigned RefCount;

  template <typename T> friend struct llvm::IntrusiveRefCntPtrInfo;
  void Retain() const { ++RefCount; }
  void Release() const;

protected:
  friend class CallEventManager;

  CallEvent(const Expr *E, ProgramStateRef state, const LocationContext *lctx)
    : State(state), LCtx(lctx), Origin(E), RefCount(0) {}

  CallEvent(const Decl *