[LLVMdev] static constant structs

[Duncan Sands]

Hi Michael,

> I hope this is the correct forum in which to ask this question.
>
> Currently I am writing code meant to compile with LLVM 3.0.  I am trying
> to figure out, using the C++ API, how to create a constant static
> struct, or the equivalent.  Since I am copying data from existing C
> structs, I am currently I am using a ConstantArray global variable, and
> then pointer casting it to the appropriate type when I use it, but this
> seems overly clunky.
>
>      Constant *cip = ConstantArray::get(
>          ctx(), StringRef((char *)&addr_, sizeof(addr_)), false);
>      return new GlobalVariable(
>          *mod(), cip->getType(), true,
>          GlobalVariable::PrivateLinkage, cip);
>
> In a previous version of my code, I replaced cip->getType() with the
> llvm equivalent of the type of addr_.  This worked until I tried with a
> build of llvm that had assertions turned on.  Even without that, I am
> hoping there is a better way to do this that I have managed to overlook.
>

I'm not sure I understood your question, but it sounds like you may want to call
this ConstantArray method (with AddNull = false).

   /// This method constructs a ConstantArray and initializes it with a text
   /// string. The default behavior (AddNull==true) causes a null terminator to
   /// be placed at the end of the array. This effectively increases the length
   /// of the array by one (you've been warned).  However, in some situations
   /// this is not desired so if AddNull==false then the string is copied without
   /// null termination.
   static Constant *get(LLVMContext &Context, StringRef Initializer,
                        bool AddNull = true);

Ciao, Duncan.