public inbox for binutils@sourceware.org
 help / color / mirror / Atom feed
From: Ian Lance Taylor <iant@google.com>
To: John Marino <binutils@marino.st>
Cc: binutils@sourceware.org
Subject: Re: gold linker 2.22 regressed for DragonFly
Date: Fri, 02 Dec 2011 04:59:00 -0000	[thread overview]
Message-ID: <mcrmxbbk1rp.fsf@dhcp-172-18-216-180.mtv.corp.google.com> (raw)
In-Reply-To: <4ED7FCA6.8090706@marino.st> (John Marino's message of "Thu, 01	Dec 2011 23:16:06 +0100")

John Marino <binutils@marino.st> writes:

> When binutils 2.21 was imported into DragonFly, gold could successful
> link world and kernel, but not the kernel modules.  When binutils 2.22
> was imported, gold can no longer even link itself.
>
> After executing "gmake check-TESTS", the new version of gold linked by
> gold segfaults immediately.  The General_Options->format() method
> returns null, crashing string_to_object_format in options.cc.  I'm not
> very strong in C++, so I'm having trouble figuring out why format() is
> not getting defined, or what has changed between gold 2.21 and gold
> 2.22.
>
> The backtrace is attached.  I'm sure somebody here should be able to
> point me to code that should be modified to support DragonFly BSD.
>
> Thanks,
> John
>
> The program being debugged has been started already.
> Start it from the beginning? (y or n) 
> Starting program: /home/marino/workzone/test-222/gold/ld1 
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x000000000052e534 in gold::General_options::string_to_object_format (arg=0x0)
>     at ../../binutils-2.22/gold/options.cc:655
> 655	  if (strncmp(arg, "elf", 3) == 0)
> #0  0x000000000052e534 in gold::General_options::string_to_object_format (
>     arg=0x0) at ../../binutils-2.22/gold/options.cc:655

string_to_object_format is being called with a NULL pointer.

> #1  0x000000000053b5e2 in format_enum (this=0x62a5fe)
>     at ../../binutils-2.22/gold/options.cc:937

This line is
  return General_options::string_to_object_format(this->format());
so this->format() is return a NULL string.

That should not happen.  this->format() is going to return the value of
this->format_.value.  That should be initialized to "elf" and nothing
should ever change it to NULL.  In this case "this" appears to refer to
the static variable Position_dependent_options::default_options_.

I'm not aware of anything that has changed in this area between binutils
2.21 and 2.22.  The same code is in 2.21.

I guess I would debug it by verifying that
Position_independent_options::default_options_.format_.value is in fact
initialized to "elf".  If not, why not?  If it is, when does it change?

Ian

  reply	other threads:[~2011-12-02  4:59 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-01 22:16 John Marino
2011-12-02  4:59 ` Ian Lance Taylor [this message]
2011-12-02  8:44   ` John Marino
2011-12-02 14:28     ` Ian Lance Taylor
2011-12-31 16:40       ` John Marino
2012-01-02  2:05         ` Ian Lance Taylor
2012-01-02  9:36           ` John Marino
2012-01-02 18:38             ` Ian Lance Taylor
2012-01-02 19:27               ` John Marino
2012-01-02 19:48                 ` John Marino
2012-01-02 22:56                   ` John Marino
2012-01-03  9:20                     ` gold linker 2.22 regressed for DragonFly [revised testsuite results] John Marino
2012-01-05 18:32                       ` Ian Lance Taylor
2012-01-06 10:24                         ` John Marino
2012-01-06 14:43                           ` Ian Lance Taylor
2012-01-06 20:04                             ` John Marino
2012-01-22 18:59                               ` John Marino
2012-01-22 19:43                                 ` Ian Lance Taylor
2012-01-22 20:46                                   ` John Marino
2012-01-23 16:49                                     ` Ian Lance Taylor
2012-01-03 19:43                 ` gold linker 2.22 regressed for DragonFly Ian Lance Taylor
2012-01-05 17:30                   ` John Marino

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=mcrmxbbk1rp.fsf@dhcp-172-18-216-180.mtv.corp.google.com \
    --to=iant@google.com \
    --cc=binutils@marino.st \
    --cc=binutils@sourceware.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).