[PATCH] D137360: [Linker] Remove nocallback attribute while linking

[Gulfem Savrun Yeniceri via Phabricator via llvm-commits]

gulfem added a comment.

In D137360#4001629 <https://reviews.llvm.org/D137360#4001629>, @tejohnson wrote:

> I haven't read through the details of this issue yet, but implementing the fix in the ModuleLinker will not fix ThinLTO in any cases, or LTO when called from lld or gold. The ModuleLinker is legacy code that is invoked afaik only in a few cases such as by the legacy LTO (still used by ld64) and the llvm-lto tool, as well as the llvm-link tool. It is now built on top of the IRMover (see uses of a variable of this type in LinkModules.cpp). ThinLTO uses IRMover directly (see FunctionImport.cpp), as does the newer LTO API (see lib/LTO/LTO.cpp) utilized by lld and gold. The new LTO API can be tested via the llvm-lto2 tool.
>
> The IRMover itself is built up the IRLinker (also in IRMover.cpp), and I suspect that is where the attibute fixup should be done, to handle all of these cases in one place. In fact, the comments at the declaration for IRLinker::copyGlobalValueProto in IRMover.cpp say that attribute fixup should be done there, so that seems like the right place.

Thanks for the suggestion @tejohnson, and I moved it into IRMover. I did not directly add it to `copyGlobalValueProto` because we need to remove the attribute from the call sites as well. So, I added it after function body is linked (https://github.com/llvm/llvm-project/blob/main/llvm/lib/Linker/IRMover.cpp#L637).
Please let me know if there are any concerns.


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