[PATCH] D26255: [cmake] Rename HAVE_DIA_SDK to LLVM_ENABLE_DIA_SDK, and expose in LLVMConfig

[Michał Górny via llvm-commits]

mgorny added a comment.

In https://reviews.llvm.org/D26255#588591, @beanz wrote:

> I think you're conflating two different types of variables, and I don't understand why.
>
> `LLVM_ENABLE_*` variables are intended to be used for people to opt in or out of functionality. `HAVE_*` variables are for compiler checks against the system capabilities. Generally system capabilities shouldn't be captured in LLVM installed bits, which is what you're doing here.


I was considering this issue, and I've decided having user control over DIA SDK a worthwhile future effort. While this patch doesn't add it, it prepares the stuff to use it when it's added.

> I think the correct solution would be for you to perform the `HAVE_DIA_SDK` check in LLDB as well as LLVM. If the code is sufficiently complex, the LLVM version of the code could be abstracted into a module and re-used.

DIA support enables some PDB debug format support in LLVM, that is unavailable otherwise. LLDB doesn't use DIA at all but the PDB tests require DIA support enabled during LLVM build. In this regard, it's similar to zlib support, upon which I based my patch.


https://reviews.llvm.org/D26255