[Lldb-commits] [lldb] [lldb] fix the "RegisterValue::SetValueFromData" method (PR #163646)

[David Spickett via lldb-commits]

DavidSpickett wrote:

Thanks for the reproducer. Please include it in the PR description as well, as it may be the closest thing we get to a test case.

I'm still not clear how you found this, but if the answer is:
* You spotted it by reading code
* You have a downstream target with registers like this
* You are working on some NDA'd thing

Then the conclusion is the same. Hard to test this with an upstream target.

We have faked targets in testing before, so I think we could fake an AArch64 where V registers were not vectors, as this type is set in the XML sent from the debug server. `lldb/test/API/functionalities/gdb_remote_client/TestXMLRegisterFlags.py` is an example of this.

Then again, I found that there's no public API for this call. Running an expression on a fake target like that could work but it'd be a lot of mock stuff to implement (for a start, we'd need to pretend it can JIT code).

We have some tests that put a simulated debug sever in front of a real one, but that's too much effort for this fix.

Let me think about it for a bit. If I don't come up with anything then I'll approve this, as it does look correct to me.

https://github.com/llvm/llvm-project/pull/163646