public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "wilson at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/64697] C++11 thread_local: relocation truncated to fit: R_X86_64_PC32 against undefined symbol `TLS init function for N::ptd'
Date: Thu, 26 Mar 2020 22:03:11 +0000 [thread overview]
Message-ID: <bug-64697-4-u9vVxEKK59@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-64697-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64697
Jim Wilson <wilson at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |wilson at gcc dot gnu.org
--- Comment #22 from Jim Wilson <wilson at gcc dot gnu.org> ---
This looks like a binutils bug to me. A call to an undefined weak function
should never be executed, so it is OK for the linker to convert that call
instruction into anything convenient. There is no need for a relocation that
can reach an address of zero. We can convert the call instruction to call
itself, or the next instruction, or change it to a nop, what ever is
convenient, it doesn't really matter.
A number of binutils ports already have code to handle related problems. ARM
and RISC-V for sure. Probably others. It looks like this support is missing
from the x86_64 port. I'd suggest refiling this as a binutils bug. See for
instance
https://sourceware.org/bugzilla/show_bug.cgi?id=23244
for a RISC-V example of the same problem. But we need a new bug for the x86_64
problem. RISC-V has a register hard wired to zero, so I rewrite the call
instruction to use x0 as the base address. The arm port turns the call into a
nop.
next prev parent reply other threads:[~2020-03-26 22:03 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-20 19:16 [Bug c++/64697] New: " vhaisman at gmail dot com
2015-01-20 19:18 ` [Bug c++/64697] " vhaisman at gmail dot com
2020-03-26 22:03 ` wilson at gcc dot gnu.org [this message]
2020-03-26 23:02 ` vhaisman at gmail dot com
2020-03-26 23:06 ` wilson at gcc dot gnu.org
2021-10-01 8:56 ` cvs-commit at gcc dot gnu.org
2021-10-01 8:59 ` cvs-commit at gcc dot gnu.org
2021-10-01 9:02 ` cvs-commit at gcc dot gnu.org
2021-10-01 9:05 ` ebotcazou at gcc dot gnu.org
2022-10-14 10:31 ` ebotcazou at gcc dot gnu.org
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=bug-64697-4-u9vVxEKK59@http.gcc.gnu.org/bugzilla/ \
--to=gcc-bugzilla@gcc.gnu.org \
--cc=gcc-bugs@gcc.gnu.org \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).