omjavaid added a comment. In D96458#2613244 <https://reviews.llvm.org/D96458#2613244>, @labath wrote:
> In D96458#2578760 <https://reviews.llvm.org/D96458#2578760>, @omjavaid wrote: > >> In D96458#2566347 <https://reviews.llvm.org/D96458#2566347>, @labath wrote: >> >>> I'm sorry, my response times are pretty slow these days. >>> >>> I'm thinking about this `ConfigureRegisterInfos` business. I get that the >>> vector length is variable, and so we need to refresh it after every stop. >>> However, the set of enabled extensions seems more static. >>> >>> Is it possible for that to change during the lifetime of the process? I'd >>> guess not, because otherwise we'd have to also resend the register lists >>> after every stop. And, if that's the case, I'm wondering if there's a way >>> to reflect this static-ness in the code. For example, by doing this setup >>> in the constructor, instead of a late `ConfigureRegisterInfos` call. IIRC, >>> the register contexts are created when the thread is stopped, so it should >>> be possible to fetch the information about supported registers quite early. >>> >>> What do you think? >> >> Yes that is doable. I ll move ConfigureRegisterInfos part into constructor. > > There's still one `ConfigureRegisterInfos` call in the > `RegisterContextCorePOSIX_arm64::ConfigureRegisterContext` function. Is that > an omission, or is it intentional (i.e., needed to support some arm feature)? > Because, if that's intentional, then the moving the setup to the constructor > does not achieve what I wanted, as the set of registers can be overridden > afterwards. It also means we need to have a bigger discussion about how to > communicate the changed registers between the client and server. OTOH, if > it's not intentional, then I'd like to remove that call, to make it obvious > that the set of registers cannot change (only their length, for sve registers > and such). > > So, let me try to ask a direct question: Is there any situation in which the > set of registers accessible to the inferior (and lldb-server) can change > during the lifetime of a single process. If so, what is it? ConfigureRegisterContext is called only once in the lifetime of a core from RegisterContextCorePOSIX_arm64 constructor. A process registers cannot change during execution which is what made basis of this change. for NativeRegisterContextLinux_arm64 I moved the ConfigureRegisterInfos logic out of configure register context because it will be called again and again during execution. But for RegisterContextCorePOSIX_arm64 we call it once in the constructor so its safe to keep the function. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D96458/new/ https://reviews.llvm.org/D96458 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
