[PATCH] D52344: [Clang][CodeGen][ObjC]: Fix non-bridged CoreFoundation builds on ELF targets that use `-fconstant-cfstrings`.

[Shoaib Meenai via Phabricator via cfe-commits]

smeenai added a comment.

In https://reviews.llvm.org/D52344#1242530, @rjmccall wrote:

> In https://reviews.llvm.org/D52344#1242451, @kristina wrote:
>
> > Would you be okay with me renaming `cfstring` to `.cfstring` for ELF so it's in line with ELF section naming conventions (I'm not entirely sure if that could cause issues with ObjC stuff)? And yes I think it's best to avoid that code-path altogether if it turns out to be a constant as that's likely from the declaration of the type, I'll write a FileCheck test in a moment and check that I can apply the same logic to ELF aside from the DLL stuff as CoreFoundation needs to export the symbol somehow while preserving the implicit extern attribute for every other TU that comes from the builtin that `CFSTR` expands to. Is what I'm suggesting making sense? If not, let me know, I may be misunderstanding what's happening here.
>
>
> Following the ELF conventions seems like the right thing to do, assuming it doesn't cause compatibility problems.  David Chisnall might know best here.


We would lose the `__start_` and `__end_` markers (which @compnerd mentioned) if the section was renamed to `.cfstring`, because the linker only generates those markers for sections whose names are valid C identifiers, so I don't think that rename would be valid. Here's how LLD does it, for example: https://reviews.llvm.org/diffusion/L/browse/lld/trunk/ELF/Writer.cpp;342772$1764-1776


Repository:
  rC Clang

https://reviews.llvm.org/D52344