C++ GetElementPtrInst::eraseFromParent方法代码示例

//.........这里部分代码省略.........
    Instruction *New;
    if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
      New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
                               Args.begin(), Args.end(), "", Call);
      cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
      cast<InvokeInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(),
                                                          AttributesVec.end()));
    } else {
      New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
      cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
      cast<CallInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(),
                                                        AttributesVec.end()));
      if (cast<CallInst>(Call)->isTailCall())
        cast<CallInst>(New)->setTailCall();
    }
    Args.clear();
    AttributesVec.clear();

    // Update the alias analysis implementation to know that we are replacing
    // the old call with a new one.
    AA.replaceWithNewValue(Call, New);

    // Update the callgraph to know that the callsite has been transformed.
    CallGraphNode *CalleeNode = CG[Call->getParent()->getParent()];
    CalleeNode->replaceCallEdge(Call, New, NF_CGN);

    if (!Call->use_empty()) {
      Call->replaceAllUsesWith(New);
      New->takeName(Call);
    }

    // Finally, remove the old call from the program, reducing the use-count of
    // F.
    Call->eraseFromParent();
  }

  // Since we have now created the new function, splice the body of the old
  // function right into the new function, leaving the old rotting hulk of the
  // function empty.
  NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList());

  // Loop over the argument list, transfering uses of the old arguments over to
  // the new arguments, also transfering over the names as well.
  //
  for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(),
       I2 = NF->arg_begin(); I != E; ++I) {
    if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) {
      // If this is an unmodified argument, move the name and users over to the
      // new version.
      I->replaceAllUsesWith(I2);
      I2->takeName(I);
      AA.replaceWithNewValue(I, I2);
      ++I2;
      continue;
    }

    if (ByValArgsToTransform.count(I)) {
      // In the callee, we create an alloca, and store each of the new incoming
      // arguments into the alloca.
      Instruction *InsertPt = NF->begin()->begin();

      // Just add all the struct element types.
      const Type *AgTy = cast<PointerType>(I->getType())->getElementType();
      Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt);
      const StructType *STy = cast<StructType>(AgTy);
      Value *Idxs[2] = {

//
// Methods: insertBadIndexing()
//
// Description:
//  This method modifieds GEP indexing expressions so that their indices are
//  (most likely) below the bounds of the object pointed to by the source
//  pointer.  It does this by modifying the first index to be -1.
//
// Return value:
//  true  - One or more changes were made to the program.
//  false - No changes were made to the program.
//
bool
FaultInjector::insertBadIndexing (Function & F) {
  // Worklist of allocation sites to rewrite
  std::vector<GetElementPtrInst *> WorkList;

  //
  // Find GEP instructions that index into an array.  Add these to the
  // worklist.
  //
  for (Function::iterator fI = F.begin(), fE = F.end(); fI != fE; ++fI) {
    BasicBlock & BB = *fI;
    for (BasicBlock::iterator I = BB.begin(), bE = BB.end(); I != bE; ++I) {
      if (GetElementPtrInst * GEP = dyn_cast<GetElementPtrInst>(I)) {
        // Skip if we should not insert a fault.
        if (!doFault()) continue;

        WorkList.push_back (GEP);
      }
    }
  }

  // Flag whether the program was modified
  bool modified = (WorkList.size() > 0);

  //
  // Iterator through the worklist and transform each GEP.
  //
  while (WorkList.size()) {
    GetElementPtrInst * GEP = WorkList.back();
    WorkList.pop_back();

    //
    // Print out where the fault will be inserted in the source code.
    //
    printSourceInfo ("Bad indexing", GEP);

    // The index arguments to the new GEP
    std::vector<Value *> args;

    //
    // Create a copy of the GEP's indices.
    //
    User::op_iterator i = GEP->idx_begin();
    if (i == GEP->idx_end()) continue;
    args.push_back (ConstantInt::get (Int32Type, INT_MAX, true));
    for (++i; i != GEP->idx_end(); ++i) {
      args.push_back (*i);
    }

    //
    // Create the new GEP instruction.
    //
    Value * Pointer = GEP->getPointerOperand();
    Twine name = GEP->getName() + "badindex";
    GetElementPtrInst * NewGEP = GetElementPtrInst::Create (Pointer,
                                                            args.begin(),
                                                            args.end(),
                                                            name,
                                                            GEP);
    GEP->replaceAllUsesWith (NewGEP);
    GEP->eraseFromParent();
    ++BadIndices;
  }

  return modified;
}

/// updateCallSites - Update all sites that call F to use NF.
CallGraphNode *SRETPromotion::updateCallSites(Function *F, Function *NF) {
  CallGraph &CG = getAnalysis<CallGraph>();
  SmallVector<Value*, 16> Args;

  // Attributes - Keep track of the parameter attributes for the arguments.
  SmallVector<AttributeWithIndex, 8> ArgAttrsVec;

  // Get a new callgraph node for NF.
  CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF);

  while (!F->use_empty()) {
    CallSite CS(*F->use_begin());
    Instruction *Call = CS.getInstruction();

    const AttrListPtr &PAL = F->getAttributes();
    // Add any return attributes.
    if (Attributes attrs = PAL.getRetAttributes())
      ArgAttrsVec.push_back(AttributeWithIndex::get(0, attrs));

    // Copy arguments, however skip first one.
    CallSite::arg_iterator AI = CS.arg_begin(), AE = CS.arg_end();
    Value *FirstCArg = *AI;
    ++AI;
    // 0th parameter attribute is reserved for return type.
    // 1th parameter attribute is for first 1st sret argument.
    unsigned ParamIndex = 2; 
    while (AI != AE) {
      Args.push_back(*AI); 
      if (Attributes Attrs = PAL.getParamAttributes(ParamIndex))
        ArgAttrsVec.push_back(AttributeWithIndex::get(ParamIndex - 1, Attrs));
      ++ParamIndex;
      ++AI;
    }

    // Add any function attributes.
    if (Attributes attrs = PAL.getFnAttributes())
      ArgAttrsVec.push_back(AttributeWithIndex::get(~0, attrs));
    
    AttrListPtr NewPAL = AttrListPtr::get(ArgAttrsVec.begin(), ArgAttrsVec.end());
    
    // Build new call instruction.
    Instruction *New;
    if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
      New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
                               Args.begin(), Args.end(), "", Call);
      cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
      cast<InvokeInst>(New)->setAttributes(NewPAL);
    } else {
      New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
      cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
      cast<CallInst>(New)->setAttributes(NewPAL);
      if (cast<CallInst>(Call)->isTailCall())
        cast<CallInst>(New)->setTailCall();
    }
    Args.clear();
    ArgAttrsVec.clear();
    New->takeName(Call);

    // Update the callgraph to know that the callsite has been transformed.
    CallGraphNode *CalleeNode = CG[Call->getParent()->getParent()];
    CalleeNode->removeCallEdgeFor(Call);
    CalleeNode->addCalledFunction(New, NF_CGN);
    
    // Update all users of sret parameter to extract value using extractvalue.
    for (Value::use_iterator UI = FirstCArg->use_begin(), 
           UE = FirstCArg->use_end(); UI != UE; ) {
      User *U2 = *UI++;
      CallInst *C2 = dyn_cast<CallInst>(U2);
      if (C2 && (C2 == Call))
        continue;
      
      GetElementPtrInst *UGEP = cast<GetElementPtrInst>(U2);
      ConstantInt *Idx = cast<ConstantInt>(UGEP->getOperand(2));
      Value *GR = ExtractValueInst::Create(New, Idx->getZExtValue(),
                                           "evi", UGEP);
      while(!UGEP->use_empty()) {
        // isSafeToUpdateAllCallers has checked that all GEP uses are
        // LoadInsts
        LoadInst *L = cast<LoadInst>(*UGEP->use_begin());
        L->replaceAllUsesWith(GR);
        L->eraseFromParent();
      }
      UGEP->eraseFromParent();
      continue;
    }
    Call->eraseFromParent();
  }
  
  return NF_CGN;
}

//.........这里部分代码省略.........
    CS.getOperandBundlesAsDefs(OpBundles);

    CallSite NewCS;
    if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
      NewCS = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
                                 Args, OpBundles, "", Call);
    } else {
      auto *NewCall = CallInst::Create(NF, Args, OpBundles, "", Call);
      NewCall->setTailCallKind(cast<CallInst>(Call)->getTailCallKind());
      NewCS = NewCall;
    }
    NewCS.setCallingConv(CS.getCallingConv());
    NewCS.setAttributes(
        AttributeList::get(F->getContext(), CallPAL.getFnAttributes(),
                           CallPAL.getRetAttributes(), ArgAttrVec));
    NewCS->setDebugLoc(Call->getDebugLoc());
    uint64_t W;
    if (Call->extractProfTotalWeight(W))
      NewCS->setProfWeight(W);
    Args.clear();
    ArgAttrVec.clear();

    // Update the callgraph to know that the callsite has been transformed.
    if (ReplaceCallSite)
      (*ReplaceCallSite)(CS, NewCS);

    if (!Call->use_empty()) {
      Call->replaceAllUsesWith(NewCS.getInstruction());
      NewCS->takeName(Call);
    }

    // Finally, remove the old call from the program, reducing the use-count of
    // F.
    Call->eraseFromParent();
  }

  const DataLayout &DL = F->getParent()->getDataLayout();

  // Since we have now created the new function, splice the body of the old
  // function right into the new function, leaving the old rotting hulk of the
  // function empty.
  NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList());

  // Loop over the argument list, transferring uses of the old arguments over to
  // the new arguments, also transferring over the names as well.
  for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(),
                              I2 = NF->arg_begin();
       I != E; ++I) {
    if (!ArgsToPromote.count(&*I) && !ByValArgsToTransform.count(&*I)) {
      // If this is an unmodified argument, move the name and users over to the
      // new version.
      I->replaceAllUsesWith(&*I2);
      I2->takeName(&*I);
      ++I2;
      continue;
    }

    if (ByValArgsToTransform.count(&*I)) {
      // In the callee, we create an alloca, and store each of the new incoming
      // arguments into the alloca.
      Instruction *InsertPt = &NF->begin()->front();

      // Just add all the struct element types.
      Type *AgTy = cast<PointerType>(I->getType())->getElementType();
      Value *TheAlloca = new AllocaInst(AgTy, DL.getAllocaAddrSpace(), nullptr,
                                        I->getParamAlignment(), "", InsertPt);