llvm dev - Jan 2009 - [LLVMdev] GlobalVaraible and Function have the same name

Hi all,

I just walked across an interesting situation in 
Module::getOrInsertFunction(Name, Type) in the LLVM C API.

In my particular case:

One of the first things we do is add a global variable named foo which 
is a [ 100 x i64 ].

Later we add a function    void foo(...)

unfortunately, when we do the getOrInsertFunction we get back

 void (...) *  bitcast ([100 x i64]* @foo_ to void (...)*)

because the symbol foo already exists in the ValueSymbolTable.

Am I correct in interpreting this as a constraint that no two items in 
the ValueSymbolTable
can have the same name, even if they're of entirely different types (in 
this case Function entry point and
global variable) ?  Is there any way, short of renaming on our end, 
around this? Thanks!


    -Tony S.

On Jan 12, 2009, at 9:35 AM, Tony Scudiero wrote:
> Am I correct in interpreting this as a constraint that no two items in
> the ValueSymbolTable
> can have the same name, even if they're of entirely different types  
> (in
> this case Function entry point and
> global variable)?
Yes.
>  Is there any way, short of renaming on our end,
> around this? Thanks!
You can use some form of name mangling.  This is what C++ compilers do  
to implement support for overloading.

-Chris

On 2009-01-12, at 12:35, Tony Scudiero wrote:
> Am I correct in interpreting this as a constraint that no two items  
> in the ValueSymbolTable can have the same name, even if they're of  
> entirely different types (in this case Function entry point and  
> global variable) ?  Is there any way, short of renaming on our end,   
> around this? Thanks!

That's correct; LLVM does not support overloading symbols based on  
type. Neither does the linker, though. If you're implementing a high  
level language, you may need to implement name mangling.

http://en.wikipedia.org/wiki/Name_mangling

— Gordon