[lld] [llvm] [llvm][lld] Support R_AARCH64_GOTPCREL32 (PR #72584)

[Fangrui Song via llvm-commits]

MaskRay wrote:

I don't have a Rust development environment, but these components are likely involved:

* Rust LLVM IR producer
* llvm/lib/Transforms/Utils/RelLookupTableConverter.cpp
* llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp:handleIndirectSymViaGOTPCRel  This converts GOT-equivalent `Constant` uses to GOTPCREL style fixups.
* llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFObjectWriter.cpp lowers GOTPCREL style fixups to relocations, where R_AARCH64_GOTPCREL32 is not supported by GNU ld or older LLD.

Implementing a workaround in LLVM's Transforms or CodeGen sections might seem appealing for broader IR producer support, but we generally aim to avoid adding linker compatibility checks...
I'm currently leaning towards Rust implementing the workaround within its IR producer...


https://github.com/llvm/llvm-project/pull/72584