Ejemplo n.º 1
0
RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const {
  // Do we have a decl at all?
  const Decl *D = getDecl();
  if (!D)
    return RuntimeDefinition();

  // If the method is non-virtual, we know we can inline it.
  const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
  if (!MD->isVirtual())
    return AnyFunctionCall::getRuntimeDefinition();

  // Do we know the implicit 'this' object being called?
  const MemRegion *R = getCXXThisVal().getAsRegion();
  if (!R)
    return RuntimeDefinition();

  // Do we know anything about the type of 'this'?
  DynamicTypeInfo DynType = getState()->getDynamicTypeInfo(R);
  if (!DynType.isValid())
    return RuntimeDefinition();

  // Is the type a C++ class? (This is mostly a defensive check.)
  QualType RegionType = DynType.getType()->getPointeeType();
  assert(!RegionType.isNull() && "DynamicTypeInfo should always be a pointer.");

  const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl();
  if (!RD || !RD->hasDefinition())
    return RuntimeDefinition();

  // Find the decl for this method in that class.
  const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true);
  if (!Result) {
    // We might not even get the original statically-resolved method due to
    // some particularly nasty casting (e.g. casts to sister classes).
    // However, we should at least be able to search up and down our own class
    // hierarchy, and some real bugs have been caught by checking this.
    assert(!RD->isDerivedFrom(MD->getParent()) && "Couldn't find known method");
    
    // FIXME: This is checking that our DynamicTypeInfo is at least as good as
    // the static type. However, because we currently don't update
    // DynamicTypeInfo when an object is cast, we can't actually be sure the
    // DynamicTypeInfo is up to date. This assert should be re-enabled once
    // this is fixed. <rdar://problem/12287087>
    //assert(!MD->getParent()->isDerivedFrom(RD) && "Bad DynamicTypeInfo");

    return RuntimeDefinition();
  }

  // Does the decl that we found have an implementation?
  const FunctionDecl *Definition;
  if (!Result->hasBody(Definition))
    return RuntimeDefinition();

  // We found a definition. If we're not sure that this devirtualization is
  // actually what will happen at runtime, make sure to provide the region so
  // that ExprEngine can decide what to do with it.
  if (DynType.canBeASubClass())
    return RuntimeDefinition(Definition, R->StripCasts());
  return RuntimeDefinition(Definition, /*DispatchRegion=*/0);
}
Ejemplo n.º 2
0
RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const {
  const ObjCMessageExpr *E = getOriginExpr();
  assert(E);
  Selector Sel = E->getSelector();

  if (E->isInstanceMessage()) {

    // Find the the receiver type.
    const ObjCObjectPointerType *ReceiverT = 0;
    bool CanBeSubClassed = false;
    QualType SupersType = E->getSuperType();
    const MemRegion *Receiver = 0;

    if (!SupersType.isNull()) {
      // Super always means the type of immediate predecessor to the method
      // where the call occurs.
      ReceiverT = cast<ObjCObjectPointerType>(SupersType);
    } else {
      Receiver = getReceiverSVal().getAsRegion();
      if (!Receiver)
        return RuntimeDefinition();

      DynamicTypeInfo DTI = getState()->getDynamicTypeInfo(Receiver);
      QualType DynType = DTI.getType();
      CanBeSubClassed = DTI.canBeASubClass();
      ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType);

      if (ReceiverT && CanBeSubClassed)
        if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl())
          if (!canBeOverridenInSubclass(IDecl, Sel))
            CanBeSubClassed = false;
    }

    // Lookup the method implementation.
    if (ReceiverT)
      if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) {
        const ObjCMethodDecl *MD = IDecl->lookupPrivateMethod(Sel);
        if (CanBeSubClassed)
          return RuntimeDefinition(MD, Receiver);
        else
          return RuntimeDefinition(MD, 0);
      }

  } else {
    // This is a class method.
    // If we have type info for the receiver class, we are calling via
    // class name.
    if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) {
      // Find/Return the method implementation.
      return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel));
    }
  }

  return RuntimeDefinition();
}
RuntimeDefinition CXXInstanceCall::getRuntimeDefinition() const {
  // Do we have a decl at all?
  const Decl *D = getDecl();
  if (!D)
    return RuntimeDefinition();

  // If the method is non-virtual, we know we can inline it.
  const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
  if (!MD->isVirtual())
    return AnyFunctionCall::getRuntimeDefinition();

  // Do we know the implicit 'this' object being called?
  const MemRegion *R = getCXXThisVal().getAsRegion();
  if (!R)
    return RuntimeDefinition();

  // Do we know anything about the type of 'this'?
  DynamicTypeInfo DynType = getState()->getDynamicTypeInfo(R);
  if (!DynType.isValid())
    return RuntimeDefinition();

  // Is the type a C++ class? (This is mostly a defensive check.)
  QualType RegionType = DynType.getType()->getPointeeType();
  const CXXRecordDecl *RD = RegionType->getAsCXXRecordDecl();
  if (!RD || !RD->hasDefinition())
    return RuntimeDefinition();

  // Find the decl for this method in that class.
  const CXXMethodDecl *Result = MD->getCorrespondingMethodInClass(RD, true);
  assert(Result && "At the very least the static decl should show up.");

  // Does the decl that we found have an implementation?
  const FunctionDecl *Definition;
  if (!Result->hasBody(Definition))
    return RuntimeDefinition();

  // We found a definition. If we're not sure that this devirtualization is
  // actually what will happen at runtime, make sure to provide the region so
  // that ExprEngine can decide what to do with it.
  if (DynType.canBeASubClass())
    return RuntimeDefinition(Definition, R->StripCasts());
  return RuntimeDefinition(Definition, /*DispatchRegion=*/0);
}
Ejemplo n.º 4
0
RuntimeDefinition ObjCMethodCall::getRuntimeDefinition() const {
  const ObjCMessageExpr *E = getOriginExpr();
  assert(E);
  Selector Sel = E->getSelector();

  if (E->isInstanceMessage()) {

    // Find the the receiver type.
    const ObjCObjectPointerType *ReceiverT = 0;
    bool CanBeSubClassed = false;
    QualType SupersType = E->getSuperType();
    const MemRegion *Receiver = 0;

    if (!SupersType.isNull()) {
      // Super always means the type of immediate predecessor to the method
      // where the call occurs.
      ReceiverT = cast<ObjCObjectPointerType>(SupersType);
    } else {
      Receiver = getReceiverSVal().getAsRegion();
      if (!Receiver)
        return RuntimeDefinition();

      DynamicTypeInfo DTI = getState()->getDynamicTypeInfo(Receiver);
      QualType DynType = DTI.getType();
      CanBeSubClassed = DTI.canBeASubClass();
      ReceiverT = dyn_cast<ObjCObjectPointerType>(DynType);

      if (ReceiverT && CanBeSubClassed)
        if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl())
          if (!canBeOverridenInSubclass(IDecl, Sel))
            CanBeSubClassed = false;
    }

    // Lookup the method implementation.
    if (ReceiverT)
      if (ObjCInterfaceDecl *IDecl = ReceiverT->getInterfaceDecl()) {
        // Repeatedly calling lookupPrivateMethod() is expensive, especially
        // when in many cases it returns null.  We cache the results so
        // that repeated queries on the same ObjCIntefaceDecl and Selector
        // don't incur the same cost.  On some test cases, we can see the
        // same query being issued thousands of times.
        //
        // NOTE: This cache is essentially a "global" variable, but it
        // only gets lazily created when we get here.  The value of the
        // cache probably comes from it being global across ExprEngines,
        // where the same queries may get issued.  If we are worried about
        // concurrency, or possibly loading/unloading ASTs, etc., we may
        // need to revisit this someday.  In terms of memory, this table
        // stays around until clang quits, which also may be bad if we
        // need to release memory.
        typedef std::pair<const ObjCInterfaceDecl*, Selector>
                PrivateMethodKey;
        typedef llvm::DenseMap<PrivateMethodKey,
                               Optional<const ObjCMethodDecl *> >
                PrivateMethodCache;

        static PrivateMethodCache PMC;
        Optional<const ObjCMethodDecl *> &Val = PMC[std::make_pair(IDecl, Sel)];

        // Query lookupPrivateMethod() if the cache does not hit.
        if (!Val.hasValue())
          Val = IDecl->lookupPrivateMethod(Sel);

        const ObjCMethodDecl *MD = Val.getValue();
        if (CanBeSubClassed)
          return RuntimeDefinition(MD, Receiver);
        else
          return RuntimeDefinition(MD, 0);
      }

  } else {
    // This is a class method.
    // If we have type info for the receiver class, we are calling via
    // class name.
    if (ObjCInterfaceDecl *IDecl = E->getReceiverInterface()) {
      // Find/Return the method implementation.
      return RuntimeDefinition(IDecl->lookupPrivateClassMethod(Sel));
    }
  }

  return RuntimeDefinition();
}