[PATCH] D140478: [RISCV] For Dwarf v5, emit indices into .debug_addr for range list entries

[Venkata Ramanaiah Nalamothu via Phabricator via llvm-commits]

RamNalamothu added a comment.

In D140478#4011085 <https://reviews.llvm.org/D140478#4011085>, @dblaikie wrote:

> Is there any mechanism that tests whether a given range bounded by two labels may be subject to linker relaxation? It'd be nice to have that abstraction and use it here (& in some other places in DWARF emission) rather than hardcoding one particular architecture.

Unless the relaxations are performed during the assembling, this may not be possible before linking because we will not know which set of labels have instruction sequence(s) that the linker actually might be able to relax after finishing the section layout.
So, depending on whether linker relaxations are enabled, I think we can only either emit relocatable symbols for all the range labels or never.

> The other place this would be needed is in the low/high_pc computation, since currently, even in DWARFv4, the high_pc is encoded as a delta from low_pc, not as a separate relocatable label, so that'd need the same checking.

I have introduced a new MCAsmInfo API to check if we need relocatable symbol references in dwarf entries based on whether the linker relaxations are enabled.


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