llvm dev - Nov 2010 - [LLVMdev] how to get a void type value in llvm

Hi, I want to insert a function with a void type parameter,
for example: int foo(void);
OI declared
fcall2 = M.getOrInsertFunction("foo",
			    IntegerType::get(M.getContext(), 32),
			    Type::getVoidTy(M.getContext()));

then the question is how to get the void type value to make the
CallInst inserted sucessfully? (what should be ********)
CallInst::Create(fcall2, ******, "", insertPos);


-- 

--Shuying

Hi Shuying,

You will find in the documentation that amongst the overloaded
CallInst::Create()'s there is one that takes no function arguments:
static CallInst* llvm::CallInst::Create ( Value * F, const Twine & NameStr,
BasicBlock * InsertAtEnd);

Regards

On 23/11/2010, at 11:20 AM, Shuying Liang wrote:
> Hi, I want to insert a function with a void type parameter,
> for example: int foo(void);
> OI declared
> fcall2 = M.getOrInsertFunction("foo",
> 			    IntegerType::get(M.getContext(), 32),
> 			    Type::getVoidTy(M.getContext()));
> 
> then the question is how to get the void type value to make the
> CallInst inserted sucessfully? (what should be ********)
> CallInst::Create(fcall2, ******, "", insertPos);
> 
> 
> -- 
> 
> --Shuying
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
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Hi, sivart

Thanks for pointing it out. I used it, and it works. Thank you again.

BTW, for any later reference, the function prototype declaration with
no arguments is not what I wrote:
fcall2 = M.getOrInsertFunction("foo",
    IntegerType::get(M.getContext(), 32),
    Type::getVoidTy(M.getContext()));

INSTEAD, I changed to :

fcall2 = M.getOrInsertFunction("foo", FunctionType::get(
IntegerType::get(M.getContext(), 32), false));
combining with this, the insertion works finally.
Thanks,
--Shuying

On Mon, Nov 22, 2010 at 6:07 PM,  <o.j.sivart at gmail.com>
wrote:
> Hi Shuying,
> You will find in the documentation that amongst the
> overloaded CallInst::Create()'s there is one that takes no function
> arguments:
> static CallInst*
>
llvm::CallInst::Create ( Value * F, const Twine & NameStr, BasicBlock * InsertAtEnd);
>
> Regards
> On 23/11/2010, at 11:20 AM, Shuying Liang wrote:
>
> Hi, I want to insert a function with a void type parameter,
> for example: int foo(void);
> OI declared
> fcall2 = M.getOrInsertFunction("foo",
>    IntegerType::get(M.getContext(), 32),
>    Type::getVoidTy(M.getContext()));
>
> then the question is how to get the void type value to make the
> CallInst inserted sucessfully? (what should be ********)
> CallInst::Create(fcall2, ******, "", insertPos);
>
>
> --
>
> --Shuying
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>


-- 

--Shuying