示例#1
0
// visitCallInst - This converts all LLVM call instructions into invoke
// instructions. The except part of the invoke goes to the "LongJmpBlkPre"
// that grabs the exception and proceeds to determine if it's a longjmp
// exception or not.
void LowerSetJmp::visitCallInst(CallInst& CI)
{
  if (CI.getCalledFunction())
    if (!IsTransformableFunction(CI.getCalledFunction()->getName()) ||
        CI.getCalledFunction()->isIntrinsic()) return;

  BasicBlock* OldBB = CI.getParent();

  // If not reachable from a setjmp call, don't transform.
  if (!DFSBlocks.count(OldBB)) return;

  BasicBlock* NewBB = OldBB->splitBasicBlock(CI);
  assert(NewBB && "Couldn't split BB of \"call\" instruction!!");
  DFSBlocks.insert(NewBB);
  NewBB->setName("Call2Invoke");

  Function* Func = OldBB->getParent();

  // Construct the new "invoke" instruction.
  TerminatorInst* Term = OldBB->getTerminator();
  std::vector<Value*> Params(CI.op_begin() + 1, CI.op_end());
  InvokeInst* II =
    InvokeInst::Create(CI.getCalledValue(), NewBB, PrelimBBMap[Func],
                       Params.begin(), Params.end(), CI.getName(), Term);
  II->setCallingConv(CI.getCallingConv());
  II->setParamAttrs(CI.getParamAttrs());

  // Replace the old call inst with the invoke inst and remove the call.
  CI.replaceAllUsesWith(II);
  CI.getParent()->getInstList().erase(&CI);

  // The old terminator is useless now that we have the invoke inst.
  Term->getParent()->getInstList().erase(Term);
  ++CallsTransformed;
}