[PATCH] D96354: Avoid conflicts between debug-info and pseudo-probe profiling

Tue Feb 16 12:41:56 PST 2021

hoy added a comment.

In D96354#2566511 <https://reviews.llvm.org/D96354#2566511>, @dblaikie wrote:

> In D96354#2566502 <https://reviews.llvm.org/D96354#2566502>, @hoy wrote:
>
>> In D96354#2554129 <https://reviews.llvm.org/D96354#2554129>, @probinson wrote:
>>
>>>> the driver had a redundant pass-through of the option
>>>
>>> I could've sworn it worked to remove that, but it didn't when I rebased, so that's gone from the final patch (i.e, the explicit pass-through in the driver is still there).  It's a functionally separate topic anyway.
>>
>> Soung
>>
>> In D96354#2566273 <https://reviews.llvm.org/D96354#2566273>, @dblaikie wrote:
>>
>>> @hoy Could you explain a bit further why these two features are incompatible/what the crash looks like? At first glance I wouldn't expect any debug info mode to be incompatible with any non-debug-info mode (maybe less useful, but not crashy levels of incompatible).
>>
>> Both debug-info mode and the pseudo-probe mode use the Dwarf discriminators but for different purposes. Therefore the passes that populate the Dwarf discriminators should not be scheduled at the same time. The crash was like compiler fatal error before this change. It
>
> Oh, that's subtle and seems somewhat unfortunate. Is that documented somewhere I could read more about?

The summary of this diff has some information https://reviews.llvm.org/D91756 . Unfortunately we haven't rolled out a formal document yet.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D96354/new/

https://reviews.llvm.org/D96354