[LLVMdev] mapping types from a bitcode module

[Michael Muller]

Clemens Hammacher wrote:
> On 2/27/12 8:27 PM, Michael Muller wrote:
> >>> 3) destructively convert all of the types in the imported module to our
> >>> existing types.
> >>
> >> That's what we actually implemented, following the idea I described in
> >> the mentioned post. We don't identify identical struct types by their
> >> name, since even in the new type system, names don't actually mean
> >> anything. You could just strip them off.
> >> Instead, we use the pointer value of the types to identify them, since
> >> originally, all our modules reside in the same LLVMContext. Since that
> >> doesn't seem to be the case in your situation, you propably would have
> >> to use the name, or attach other metadata to uniquely identify your structs.
> >
> > I was actually fearful of this approach, it looked to me like the linker was
> > at least partially copying data structures to the destination module.  I see
> > that there is a mutateType() method in Value, though it comes with a very
> > stern warning :-)
> 
> Yeah, but as long as you mutate all types consistently, it works quite 
> smoothly. The Verifier will tell you which values you missed ;)
> 
> You shouldn't forget
> - function arguments
> - initializers of global variables
> - constants
> 
> And of course you also have to consider composite types which contain a 
> remapped struct.

Very cool - thanks, Clemens!

> 
> Good luck! ;)
> 
> Clemens
> 
> 


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