[OE-core] [meta-clang] clang/LLVM versioning

[Martin Kelly]

On 03/03/2017 12:23 PM, Khem Raj wrote:
> On Fri, Mar 3, 2017 at 12:15 PM, Martin Kelly <mkelly at xevo.com> wrote:
>> On 03/03/2017 12:12 PM, Khem Raj wrote:
>>>
>>> with  meta-clang there is no desire to support multiple versions of
>>> llvm and thats why versioning was dropped however, I would still like
>>> to fix the versioning if that makes it more useful.
>>>
>>
>> OK, keeping a single version is certainly simpler. Could you clarify "I
>> would still like to fix the versioning if that makes it more useful." ?
>>
>
> say if there are other apps which depend on the versioning and
> otherwise would need patching to work with llvm from meta-clang, then
> lets fix it in meta-clang.
>

 From my investigation, it looks like the real (unwrapped) llvm-config 
is in the PATH for any recipe depending on clang-native. This means that 
when an app looks for llvm-config, it will find the real version and 
won't know that the wrapper went anywhere. Of course, if the app truly 
depends on a specific LLVM version -- due to LLVM's unstable ABI -- then 
that app will break when the meta-clang version changes. However, if we 
don't maintain multiple versions of LLVM in meta-clang, that's unavoidable.

So AFAICT we could safely remove the wrapper and have apps that set 
WANT_LLVM_RELEASE still work correctly, if they compile against our 
version of meta-clang. Since it appears the wrapper has been broken for 
for some time anyway, I'm guessing there aren't many such apps anyway.

Does that sound reasonable to you?