Ejemplo n.º 1
0
/// DeclareGlobalAllocationFunction - Declares a single implicit global
/// allocation function if it doesn't already exist.
void Sema::DeclareGlobalAllocationFunction(DeclarationName Name,
                                           QualType Return, QualType Argument)
{
  DeclContext *GlobalCtx = Context.getTranslationUnitDecl();

  // Check if this function is already declared.
  {
    DeclContext::lookup_iterator Alloc, AllocEnd;
    for (llvm::tie(Alloc, AllocEnd) = GlobalCtx->lookup(Context, Name);
         Alloc != AllocEnd; ++Alloc) {
      // FIXME: Do we need to check for default arguments here?
      FunctionDecl *Func = cast<FunctionDecl>(*Alloc);
      if (Func->getNumParams() == 1 &&
          Context.getCanonicalType(Func->getParamDecl(0)->getType())==Argument)
        return;
    }
  }

  QualType FnType = Context.getFunctionType(Return, &Argument, 1, false, 0);
  FunctionDecl *Alloc =
    FunctionDecl::Create(Context, GlobalCtx, SourceLocation(), Name,
                         FnType, FunctionDecl::None, false, true,
                         SourceLocation());
  Alloc->setImplicit();
  ParmVarDecl *Param = ParmVarDecl::Create(Context, Alloc, SourceLocation(),
                                           0, Argument, VarDecl::None, 0);
  Alloc->setParams(Context, &Param, 1);

  // FIXME: Also add this declaration to the IdentifierResolver, but
  // make sure it is at the end of the chain to coincide with the
  // global scope.
  ((DeclContext *)TUScope->getEntity())->addDecl(Context, Alloc);
}
Ejemplo n.º 2
0
void SimpleInliner::generateParamStrings(void)
{
  unsigned int ArgNum = TheCallExpr->getNumArgs();
  FunctionDecl *FD = TheCallExpr->getDirectCallee();
  unsigned int Idx;

  for(Idx = 0; Idx < FD->getNumParams(); ++Idx) {
    const ParmVarDecl *PD = FD->getParamDecl(Idx);
    std::string ParmStr = PD->getNameAsString();
    PD->getType().getAsStringInternal(ParmStr, 
                                      Context->getPrintingPolicy());
    if (Idx < ArgNum) {
      const Expr *Arg = TheCallExpr->getArg(Idx);
      ParmStr += " = ";
      std::string ArgStr("");
      RewriteHelper->getExprString(Arg, ArgStr);
      ParmStr += ArgStr;
    }
    ParmStr += ";\n";
    ParmStrings.push_back(ParmStr);
  }
}
Ejemplo n.º 3
0
void ExprEngine::VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
                                   ExplodedNodeSet &Dst) {
  // FIXME: Much of this should eventually migrate to CXXAllocatorCall.
  // Also, we need to decide how allocators actually work -- they're not
  // really part of the CXXNewExpr because they happen BEFORE the
  // CXXConstructExpr subexpression. See PR12014 for some discussion.

  unsigned blockCount = currBldrCtx->blockCount();
  const LocationContext *LCtx = Pred->getLocationContext();
  DefinedOrUnknownSVal symVal = UnknownVal();
  FunctionDecl *FD = CNE->getOperatorNew();

  bool IsStandardGlobalOpNewFunction = false;
  if (FD && !isa<CXXMethodDecl>(FD) && !FD->isVariadic()) {
    if (FD->getNumParams() == 2) {
      QualType T = FD->getParamDecl(1)->getType();
      if (const IdentifierInfo *II = T.getBaseTypeIdentifier())
        // NoThrow placement new behaves as a standard new.
        IsStandardGlobalOpNewFunction = II->getName().equals("nothrow_t");
    }
    else
      // Placement forms are considered non-standard.
      IsStandardGlobalOpNewFunction = (FD->getNumParams() == 1);
  }

  // We assume all standard global 'operator new' functions allocate memory in
  // heap. We realize this is an approximation that might not correctly model
  // a custom global allocator.
  if (IsStandardGlobalOpNewFunction)
    symVal = svalBuilder.getConjuredHeapSymbolVal(CNE, LCtx, blockCount);
  else
    symVal = svalBuilder.conjureSymbolVal(nullptr, CNE, LCtx, CNE->getType(),
                                          blockCount);

  ProgramStateRef State = Pred->getState();
  CallEventManager &CEMgr = getStateManager().getCallEventManager();
  CallEventRef<CXXAllocatorCall> Call =
    CEMgr.getCXXAllocatorCall(CNE, State, LCtx);

  // Invalidate placement args.
  // FIXME: Once we figure out how we want allocators to work,
  // we should be using the usual pre-/(default-)eval-/post-call checks here.
  State = Call->invalidateRegions(blockCount);
  if (!State)
    return;

  // If this allocation function is not declared as non-throwing, failures
  // /must/ be signalled by exceptions, and thus the return value will never be
  // NULL. -fno-exceptions does not influence this semantics.
  // FIXME: GCC has a -fcheck-new option, which forces it to consider the case
  // where new can return NULL. If we end up supporting that option, we can
  // consider adding a check for it here.
  // C++11 [basic.stc.dynamic.allocation]p3.
  if (FD) {
    QualType Ty = FD->getType();
    if (const FunctionProtoType *ProtoType = Ty->getAs<FunctionProtoType>())
      if (!ProtoType->isNothrow(getContext()))
        State = State->assume(symVal, true);
  }

  StmtNodeBuilder Bldr(Pred, Dst, *currBldrCtx);

  if (CNE->isArray()) {
    // FIXME: allocating an array requires simulating the constructors.
    // For now, just return a symbolicated region.
    const MemRegion *NewReg = symVal.castAs<loc::MemRegionVal>().getRegion();
    QualType ObjTy = CNE->getType()->getAs<PointerType>()->getPointeeType();
    const ElementRegion *EleReg =
      getStoreManager().GetElementZeroRegion(NewReg, ObjTy);
    State = State->BindExpr(CNE, Pred->getLocationContext(),
                            loc::MemRegionVal(EleReg));
    Bldr.generateNode(CNE, Pred, State);
    return;
  }

  // FIXME: Once we have proper support for CXXConstructExprs inside
  // CXXNewExpr, we need to make sure that the constructed object is not
  // immediately invalidated here. (The placement call should happen before
  // the constructor call anyway.)
  SVal Result = symVal;
  if (FD && FD->isReservedGlobalPlacementOperator()) {
    // Non-array placement new should always return the placement location.
    SVal PlacementLoc = State->getSVal(CNE->getPlacementArg(0), LCtx);
    Result = svalBuilder.evalCast(PlacementLoc, CNE->getType(),
                                  CNE->getPlacementArg(0)->getType());
  }

  // Bind the address of the object, then check to see if we cached out.
  State = State->BindExpr(CNE, LCtx, Result);
  ExplodedNode *NewN = Bldr.generateNode(CNE, Pred, State);
  if (!NewN)
    return;

  // If the type is not a record, we won't have a CXXConstructExpr as an
  // initializer. Copy the value over.
  if (const Expr *Init = CNE->getInitializer()) {
    if (!isa<CXXConstructExpr>(Init)) {
      assert(Bldr.getResults().size() == 1);
      Bldr.takeNodes(NewN);
      evalBind(Dst, CNE, NewN, Result, State->getSVal(Init, LCtx),
               /*FirstInit=*/IsStandardGlobalOpNewFunction);
    }
  }
}