[LLVMdev] Linking modules across contexts crashes

[Yuri]

On 06/02/2015 13:05, Duncan P. N. Exon Smith wrote:
> If you want to work on a solution, I think a better approach would be
> adding API for one (or both) of:
>
>      class Module {
>      public:
>          /// Move this module to the given context.
>          void changeContext(LLVMContext &NewContext);
>      };
>
>      /// Remap the given module in a different context.
>      std::unique_ptr<Module> remapModuleToContext(
>          const Module &M, LLVMContext &NewContext);

While working on the patch, I have two questions:

1. How to find all constants in Module? Does this code find all of them, 
or they are somewhere else too?
   for (GlobalVariable &GV : globals()) {
     if (auto C = static_cast<Constant*>(GV.Op<0>().get())) {
       ... C is Constant*
     }
   }

2. How to create an equivalent ConstantArray/ConstantStruct objects in 
another context? ConstantArray::get(ArrayType *T, ArrayRef<Constant*>V) 
creates it, and puts it into LLVMContextImpl::ArrayConstants. 
ArrayConstants has the DenseMap ConstantUniqueMap::Map with 
ConstantArray* as a key, but how to read back ArrayRef<Constant*> 
ConstantArray was created with?

Yuri