[llvm-dev] [RFC] Making .eh_frame more linker-friendly

[George Rimar via llvm-dev]

>> With GNU gold (GNU Binutils 2.29.51.20171006) 1.14 have an assert:
>> ~/LLVM/Release/bin/clang++ test.cpp -ffunction-sections -o test.o
>> /usr/local/bin/ld: internal error in layout_eh_frame_section, at
>> .././../gold/object.cc:1309
>> It is that place:
>> https://github.com/gittup/binutils/blob/gittup/gold/object.cc#L1372
>> Did not investigate it, but it looks it is place
>> (https://sourceware.org/ml/binutils/2009-06/msg00097.html)
>> mentioned in comment for
>> https://marc.info/?l=llvm-commits&m=144683596826489.
>
>I've committed a patch in gold that should fix this problem:
>
>   https://sourceware.org/ml/binutils/2017-11/msg00541.html
>
>Can you try gold again with this patch applied? You should at least
>get a little further.
>
>If it still doesn't work, could I trouble you for a sample object file?
>
>-cary

I'll try it soon and return with results, thanks !

Just a small clarification: your commit message saying that "LLVM is experimenting with placing
.eh_frame sections in the COMDAT group", that is true for original experiment which faced this gold issue
 (https://marc.info/?l=llvm-commits&m=144683596826489), current approach I am experimented
with (https://reviews.llvm.org/D40352) sets sh_link of .eh_frame to corresponding .text section instead.
Though anyways issue looks to be that gold did not like to have multiple .eh_frame sections and that
is what both approaches faced with and your patch seeems fixes that.

George.