Bug 26558

Summary:	[meta] Build glibc with LLD
Product:	glibc	Reporter:	Fangrui Song <i>
Component:	libc	Assignee:	Not yet assigned to anyone <unassigned>
Status:	RESOLVED FIXED
Severity:	normal	CC:	drepper.fsp, hjl.tools
Priority:	P2
Version:	unspecified
Target Milestone:	---
Host:		Target:
Build:		Last reconfirmed:	2020-09-01 00:00:00
Bug Depends on:	26559
Bug Blocks:

Description Fangrui Song 2020-08-31 23:19:30 UTC

Some known issues:

* elf/librtld.map.o uses a subtle property of --defsym: https://sourceware.org/pipermail/libc-alpha/2020-April/112732.html
* ld.lld --verbose does not print a linker script and ld.lld --print-output-format is not supported: https://sourceware.org/pipermail/libc-alpha/2020-April/112733.html
* Neither clang nor LLD may support the semantics of .tls_common https://sourceware.org/pipermail/libc-alpha/2020-April/112734.html

Comment 1 H.J. Lu 2020-09-01 12:41:11 UTC

(In reply to Fangrui Song from comment #0)
> Some known issues:
> 
> * elf/librtld.map.o uses a subtle property of --defsym:
> https://sourceware.org/pipermail/libc-alpha/2020-April/112732.html

Since --defsym in ldd is incompatible with glibc build, --defsym should be
poisoned for glibc build.

> * ld.lld --verbose does not print a linker script and ld.lld
> --print-output-format is not supported:
> https://sourceware.org/pipermail/libc-alpha/2020-April/112733.html
> * Neither clang nor LLD may support the semantics of .tls_common
> https://sourceware.org/pipermail/libc-alpha/2020-April/112734.html

This is used to implement STT_COMMON.  Do clang/LLD support STT_COMMON?

Comment 2 H.J. Lu 2020-09-01 13:08:10 UTC

I think you should make your glibc branch for lld available so that people
can give it a try.

Comment 3 H.J. Lu 2020-09-01 14:25:25 UTC

Before lld can be accepted for glibc build, it must generate the same set
of failures in glibc testsuite with binutils 2.35 at least on i686 and x86-64.

Comment 4 Fangrui Song 2021-09-06 04:41:57 UTC

Fixed by https://sourceware.org/git/?p=glibc.git;a=commit;h=224edada607ebc6aaa1aadaae423128fae7880df ("configure: Allow LD to be LLD 13.0.0 or above [BZ #26558]")

Target: 2.35