Creating a Return Instruction.

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1

Hi all,

I have to create a return instruction in a function. The function is of type – void * func (void *) . So i have to create a return instruction for the function that should return a void pointer. But actually the function will not return anything useful . it will be something like – return void * null. The problem i am facing is to create a return instruction the Create function expects a pointer to a value and i am not able to do that. How do i create such a return instruction.

Thanks,
Rohith.

2

Then I assume it should return an undef:
http://llvm.org/docs/LangRef.html#undefvalues

3

Rohith Goparaju wrote:

Hi all,

    I have to create a return instruction in a function. The function is
of type -- void * func (void *) . So i have to create a return
instruction for the function that should return a void pointer. But
actually the function will not return anything useful . it will be
something like -- return void * null. The problem i am facing is to
create a return instruction the Create function expects a pointer to a
value and i am not able to do that. How do i create such a return
instruction.

'void *' is not a valid LLVM type. Did you mean 'i8 *'?

   LLVMContext C;
   const Type *Ty = Type::getInt8Ty(C)->getPointerTo();

'ret i8* null':

   Builder.CreateRet(Constant::getNullValue(Ty));

'ret i8* undef':

   Builder.CreateRet(UndefValue::get(Ty));

Nick