Example #1
0
LatticeValue *SFVInstVisitor::getLatticeValueForField(Value *Ptr) {
  if (!isa<PointerType>(Ptr->getType()) ||
      isa<ConstantPointerNull>(Ptr)) return 0;

  const DSNodeHandle *NH = &DSG.getNodeForValue(Ptr);
  DSNode *Node = NH->getNode();
  assert(Node && "Pointer doesn't have node??");

  std::multimap<DSNode*, LatticeValue*>::iterator I = NodeLVs.find(Node);
  if (I == NodeLVs.end()) return 0;  // Not a node we are still tracking.

  // Okay, next convert the node offset to a field index expression.
  std::vector<unsigned> Idxs;
  ComputeStructureFieldIndices(Node->getType(), NH->getOffset(), Idxs,
                               Node->getParentGraph()->getTargetData());

  for (; I != NodeLVs.end() && I->first == Node; ++I)
    if (I->second->getIndices() == Idxs)
      return I->second;
  return 0;
}
Example #2
0
// Precondition: Enforce that the alloca nodes haven't been already converted
void ConvertUnsafeAllocas::TransformAllocasToMallocs(std::list<DSNode *> 
                                                     & unsafeAllocaNodes) {

  std::list<DSNode *>::const_iterator iCurrent = unsafeAllocaNodes.begin(), 
                                      iEnd     = unsafeAllocaNodes.end();

  for (; iCurrent != iEnd; ++iCurrent) {
    DSNode *DSN = *iCurrent;
    
    // Now change the alloca instruction corresponding to the node  
    // to malloc 
    DSGraph *DSG = DSN->getParentGraph();
    DSGraph::ScalarMapTy &SM = DSG->getScalarMap();

#ifndef LLVA_KERNEL    
    Instruction *MI = 0;
#else
    Value *MI = 0;
#endif
    for (DSGraph::ScalarMapTy::iterator SMI = SM.begin(), SME = SM.end();
         SMI != SME; ) {
      bool stackAllocate = true;
      // If this is already a heap node, then you cannot allocate this on the
      // stack
      if (DSN->isHeapNode()) {
        stackAllocate = false;
      }

      if (SMI->second.getNode() == DSN) {
        if (AllocaInst *AI = dyn_cast<AllocaInst>((Value *)(SMI->first))) {
          //
          // Create a new heap allocation instruction.
          //
          if (AI->getParent() != 0) {
            //
            // Create an LLVM value representing the size of the allocation.
            // If it's an array allocation, we'll need to insert a
            // multiplication instruction to get the size times the number of
            // elements.
            //
            unsigned long size = TD->getTypeAllocSize(AI->getAllocatedType());
            Value *AllocSize = ConstantInt::get(Int32Type, size);
            if (AI->isArrayAllocation())
              AllocSize = BinaryOperator::Create(Instruction::Mul, AllocSize,
                                                 AI->getOperand(0), "sizetmp",
                                                 AI);     
            std::vector<Value *> args(1, AllocSize);
            CallInst *CI = CallInst::Create (kmalloc, args.begin(), args.end(), "", AI);
            MI = castTo (CI, AI->getType(), "", AI);
            DSN->setHeapMarker();
            AI->replaceAllUsesWith(MI);
            SM.erase(SMI++);
            AI->getParent()->getInstList().erase(AI);
            ++ConvAllocas;
            InsertFreesAtEnd(MI);
#ifndef LLVA_KERNEL     
            if (stackAllocate) {
              ArrayMallocs.insert(MI);
            }
#endif        
          } else {
            ++SMI;
          } 
        } else {
          ++SMI;
        }
      } else {
        ++SMI;
      }
    }
  }  
}