Buildroot Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
To: buildroot@busybox.net
Subject: [Buildroot] [PATCH v2,1/1] gnuchess: needs -fPIC
Date: Sun, 13 Jan 2019 14:13:29 +0100	[thread overview]
Message-ID: <20190113141329.4d526438@windsurf.home> (raw)
In-Reply-To: <20190112175505.14348-1-fontaine.fabrice@gmail.com>

Hello Fabrice,

On Sat, 12 Jan 2019 18:55:05 +0100, Fabrice Fontaine wrote:
> When building with -O2 (or -O3) on ARM cortex-M cpus, link fails on:
> 
> /home/rclinux/rc-buildroot-test/scripts/instance-0/output/host/bin/arm-linux-g++ -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -O2 -Wl,-elf2flt -static  -Wl,-elf2flt -static   -Wl,-elf2flt -static -o gnuchess main.o components.o  frontend/libfrontend.a adapter/libadapter.a engine/libengine.a -lreadline -lncurses
> ERROR: reloc type R_ARM_THM_MOVW_ABS_NC unsupported in this context
> ERROR: reloc type R_ARM_THM_MOVT_ABS unsupported in this context
> ERROR: reloc type R_ARM_THM_MOVW_ABS_NC unsupported in this context
> ERROR: reloc type R_ARM_THM_MOVT_ABS unsupported in this context
> ERROR: reloc type R_ARM_THM_MOVW_ABS_NC unsupported in this context
> ERROR: reloc type R_ARM_THM_MOVT_ABS unsupported in this context
> ERROR: reloc type R_ARM_THM_MOVW_ABS_NC unsupported in this context
> 
> To fix this, pas -fPIC unconditionnally
> 
> Fixes:
>  - http://autobuild.buildroot.org/results/7918757b255ed41609609d2083c2d8904ff3136e
> 
> Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>

I'm sorry but this doesn't make sense to me. -fPIC is for Position
Independent Code, which is needed when building shared libraries. Here
we are building with -static on Cortex-M which doesn't even have
support for shared libraries. So building with -fPIC doesn't make sense
I believe. It seems to be more a workaround than a real fix.

Perhaps this should be discussed with upstream binutils, or at least a
proper investigation be done about those relocation types ?

Best regards,

Thomas
-- 
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

  reply	other threads:[~2019-01-13 13:13 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-12 17:55 [Buildroot] [PATCH v2,1/1] gnuchess: needs -fPIC Fabrice Fontaine
2019-01-13 13:13 ` Thomas Petazzoni [this message]
2019-01-23 14:21   ` Arnout Vandecappelle
2019-02-04 17:55     ` Peter Korsgaard
2019-06-23 18:23   ` Thomas Petazzoni
2019-06-25 21:04     ` Peter Korsgaard

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190113141329.4d526438@windsurf.home \
    --to=thomas.petazzoni@bootlin.com \
    --cc=buildroot@busybox.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox