[PATCH] D70350: [DWARF] Allow cross-CU references of subprogram definitions

Fri Jul 9 15:53:29 PDT 2021

kyulee added a comment.

In D70350#2868253 <https://reviews.llvm.org/D70350#2868253>, @vsk wrote:

> In D70350#2867905 <https://reviews.llvm.org/D70350#2867905>, @kyulee wrote:
>
>> @vsk As commented in https://bugs.llvm.org/show_bug.cgi?id=48790, this seems to impact us when building a large app with LTO even in XCode.
>> I don't have a cutdown but it showed up frequently blocking us stack traces with symbolication. Have we considered fixing this or backing out this change?
>
> @jmorse has a patch up that should address an issue with definition DIEs not being created in the unit referenced by their subprogram: D94976 <https://reviews.llvm.org/D94976>. I haven't caught up with the discussion there.
>
> The impact of backing out this change would be that backtraces including artificial tail call frames and parameter entry value evaluation would to an appreciable extent stop working in some of our key internal projects.

Unfortunately D94976 <https://reviews.llvm.org/D94976> was reverted by c1d45abda5c8e1b00b12ae81461c0e3705d88666 <https://reviews.llvm.org/rGc1d45abda5c8e1b00b12ae81461c0e3705d88666>. I found another discussion in https://groups.google.com/g/llvm-dev/c/V4pU7FRreNw/m/EmMPvGJyAAAJ which also reverted this as workaround.
For now, we had to revert this internally to avoid symbolication crash. I wonder if there is a right fix over this.

Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D70350/new/

https://reviews.llvm.org/D70350