[llvm-dev] Insert CallInst within a function passing same parameters of the calling function.

[Simone Atzeni via llvm-dev]

Looks like I found the solution.

When I call CallInst::Create, the param NameStr needs to be an empty string for void functions.

I thought that value was the name of the function I want to call, but apparently is not.
Why is that then?

Thanks.
Best,
Simone

> On Mar 1, 2016, at 13:51, Simone Atzeni <simone.at at gmail.com> wrote:
> 
> Hi,
> 
> supposing I have a function “foo” like the following:
> 
> int foo(int a, int b) {
> 
> ...
> ...
> }
> 
> I want to insert int the LLVM IR a call instructions to a function “bar” that requires the same parameters of foo.
> So my function foo will become:
> 
> int foo(int a, int b) {
>  bar(a,b);
>  …
>  ...
> }
> 
> I am using the following code:
> 
> bool ThreadSanitizer::runOnFunction(Function &F) {  
>    ValueToValueMapTy VMap;                                                                                                   
>    Function *new_function = CloneFunction(&F, VMap, false);                                                            
>    new_function->setName(functionName + “_newfunction");                                                               
>    F.getParent()->getFunctionList().push_back(new_function);                                                                                                  
> 
>    Function::ArgumentListType::iterator it = F.getArgumentList().begin();                                                    
>    Function::ArgumentListType::iterator end = F.getArgumentList().end();                                                     
> 
>    std::vector<Value*> args;   
>    while (it != end) {                                                                                                       
>      Argument *Args = &(*it);                                                                                                
>      args.push_back(Args);                                                                                                   
>      it++;                                                                                                                   
>    }                                                                                                                         
> 
>    CallInst::Create(new_function->getFunctionType(), new_function, args, functionName + "__swordomp__", &F.getEntryBlock().front());                                                                                                          
> }
> 
> but I am getting the following error:
> 
> void llvm::Value::setNameImpl(const llvm::Twine&): Assertion `!getType()->isVoidTy() && "Cannot assign a name to void values!"' failed.
> 
> How should I fix it?
> 
> Thanks.
> Best,
> Simone