[LLVMdev] ValueMapper question: no type mapping for GlobalValue?

[Rafael Ávila de Espíndola]

On 11/01/12 07:50 AM, Michael Muller wrote:
> 
> Hi all, I was looking at the ValueMapper code this morning and I notice that
> it doesn't do type mapping for GlobalValues.  Is this correct?
> 
> I ask because I am seeing a case where I'm failing type assertions from
> ModuleLinker::linkGlobalInits() when an array initializer references an
> external global.  It looks like the external global is being mapped directly
> and this causes an element type check to fail in ConstantArray::get().
> Curiously, this only happens when that external global is also referenced from
> within a function in the same module.
> 

Do you have a testcase?

I tried to reproduce this with

-----------
a = global i64 42, align 8
-----------

and

----------
@a = external global i32
@b = constant [1 x i32*] [i32* @a], align 8

define i32 @f() nounwind uwtable readonly optsize {
entry:
  %0 = load i32* @a, align 4
  ret i32 %0
}
----------

but llvm-link correctly produced


@b = constant [1 x i32*] [i32* bitcast (i64* @a to i32*)], align 8
@a = global i64 42, align 8

define i32 @f() nounwind uwtable readonly optsize {
entry:
  %0 = load i32* bitcast (i64* @a to i32*), align 4
  ret i32 %0
}


Cheers,
Rafael