[llvm] 75af9da - [MC][ELF] Error for sh_type, sh_flags or sh_entsize change

[Joerg Sonnenberger via llvm-commits]

On Fri, Feb 21, 2020 at 03:46:55PM -0800, Fangrui Song via llvm-commits wrote:
> 
> Author: Fangrui Song
> Date: 2020-02-21T15:44:14-08:00
> New Revision: 75af9da755721123e62b45cd0bc0c5e688a9722a
> 
> URL: https://github.com/llvm/llvm-project/commit/75af9da755721123e62b45cd0bc0c5e688a9722a
> DIFF: https://github.com/llvm/llvm-project/commit/75af9da755721123e62b45cd0bc0c5e688a9722a.diff
> 
> LOG: [MC][ELF] Error for sh_type, sh_flags or sh_entsize change
> 
> Heads-up message: https://lists.llvm.org/pipermail/llvm-dev/2020-February/139390.html
> 
> GNU as started to emit warnings for changed sh_type or sh_flags in 2000.
> GNU as>=2.35 will emit errors for most sh_type/sh_flags change, and error for entsize change.
> 
> Some cases remain warnings for legacy reasons:
> 
>    .section .init_array,"ax", @progbits
>    .section .init_array,"ax", @init_array
>    # And some obscure sh_flags changes (OS/Processor specific flags)

This is highly annoying as e.g. 32bit and 64bit x86 are different now in
the flags required for .eh_frame.

Joerg