Working with Constant Expressions

[iamrecursion]

I am attempting to process externally generated LLVM IR with Inkwell, and I am running into LLVM constant expressions. As far as I can tell, Inkwell does not provide a way to access details about these constant expressions, which is making it quite difficult for me to act upon them.

Does anybody know a route (either in pure inkwell or unsafe usage of llvm-sys) that would let me discover that a given constant integer is, for example, a ptrtoint constant expression?

[feds01]

I've come across this occasionally, you can use llvm-sys directly to construct the values, and then wrap them in an AnyValueEnum, i.e.

use llvm_sys::core as llvm:

...

// `ty` is `AnyTypeEnum<..>` or some other type that implements `AsTypeRef`
// `value` is `AnyValueEnum<..>` or some other type that implements `AsValueRef`

let my_cast_value = unsafe {
    AnyValueEnum::new(llvm::LLVMConstIntToPtr(value.as_value_ref(), ty.as_type_ref()))
}

[iamrecursion]

This works if I already know that a given expression is, for example, a constant inttoptr expression. What I am looking for is a way to tell that a given constant is one of those first up.