[PATCH] D104058: ThinLTO: Fix inline assembly references to static functions with CFI

Fri Jul 16 10:59:24 PDT 2021

samitolvanen added a comment.

In D104058#2883804 <https://reviews.llvm.org/D104058#2883804>, @nickdesaulniers wrote:

> In D104058#2878083 <https://reviews.llvm.org/D104058#2878083>, @samitolvanen wrote:
>
>> In D104058#2877631 <https://reviews.llvm.org/D104058#2877631>, @nickdesaulniers wrote:
>>
>>> Change LGTM, but I don't understand why the following tests are modified:
>>>
>>> - llvm/test/ThinLTO/X86/devirt2.ll
>>
>> This is needed to fix two `missing symbol resolution` errors that are caused by the aliases we added.
>
> I'm curious if this will lead to breakages with LTO in general? I suppose not, since it's `llvm-lto2` that needs the explicit list of symbols that can be linked against.

No, this won't break LTO.

>>> - llvm/test/Transforms/ThinLTOBitcodeWriter/split-internal2.ll
>>> - llvm/test/Transforms/ThinLTOBitcodeWriter/split-vfunc-internal.ll
>>
>> And for these, we need to specify a target triple to use module inline assembly. According to pcc, there shouldn't be a real-world situation where the triple is missing, but these two tests don't currently specify one.
>
> Neither of these tests use module inline assembly though, AFAICT?

The tests don't, but we add module inline assembly to create the aliases, which means that bitcode with type metadata will need a target triple for ThinLTO.

Repository:
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  https://reviews.llvm.org/D104058/new/

https://reviews.llvm.org/D104058