From: Nenad Vukicevic <nenad@intrepid.com>
To: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Gary Funck <gary@intrepid.com>, GCC List <gcc@gcc.gnu.org>
Subject: Re: dwarf2 - multiple DW_TAG_variable for global variable
Date: Sat, 09 Jan 2010 23:32:00 -0000 [thread overview]
Message-ID: <4B4911EC.1050102@intrepid.com> (raw)
In-Reply-To: <20100109211841.GA26361@host0.dyn.jankratochvil.net>
We used GCC regression testing to pin point PR39563 when
multiple (but not equal) definitions started appearing in
dwarf code. We used the head version of GCC, gcc-4.5.20091224
to be precise, for testing this abnormally.
I also saw appearance of DIEs duplicates you mention in PR 39524
in the following example:
extern int xxxxx;
int main(){xxxxx=1;}
gcc 4.3.2 - does NOT have duplicates
gcc 4..4.1 20090725 (REDHAT 4.4.1-2) - does have duplicates
gcc 4.4.2 - does NOT have duplicates
gcc 4.5.20091224 - does have duplicates
Duplicates are in the form described in PR39524.
In the case of this code:
int xxxxx;
int main(){xxxxx=1;}
I see duplicates in the form of:
<1><54>: Abbrev Number: 4 (DW_TAG_variable)
<55> DW_AT_name : (indirect string, offset: 0x38): xxxxx
<59> DW_AT_decl_file : 1
<5a> DW_AT_decl_line : 1
<5b> DW_AT_type : <0x4d>
<5f> DW_AT_external : 1
<60> DW_AT_declaration : 1
<1><61>: Abbrev Number: 5 (DW_TAG_variable)
<62> DW_AT_name : (indirect string, offset: 0x38): xxxxx
<66> DW_AT_decl_file : 1
<67> DW_AT_decl_line : 1
<68> DW_AT_type : <0x4d>
<6c> DW_AT_external : 1
<6d> DW_AT_location : 9 byte block: 3 0 0 0 0 0 0 0 0 (DW_OP_addr: 0)
in 4.4.1 and 4.5 releases.
Any idea if this is a correct dwarf? Or must be treated as a duplicate
somehow?
Thanks,
Nenad
On 1/9/10 1:18 PM, Jan Kratochvil wrote:
> On Sat, 09 Jan 2010 22:01:54 +0100, Gary Funck wrote:
>
>> On 01/09/10 12:39:55, Nenad Vukicevic wrote:
>>
>>> This dwarf code started appearing since this patch:
>>>
>> Here's the GCC bug report that led to this patch:
>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39563
>>
> Such DIEs duplicities are being tracked at:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39524
>
> (Unaware how/if any were caused by the PR 39563.)
>
>
> Regards,
> Jan
>
next prev parent reply other threads:[~2010-01-09 23:32 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-01-05 7:34 Nenad Vukicevic
2010-01-09 20:40 ` Nenad Vukicevic
2010-01-09 21:02 ` Gary Funck
2010-01-09 21:18 ` Jan Kratochvil
2010-01-09 23:32 ` Nenad Vukicevic [this message]
2010-01-10 8:43 ` Jan Kratochvil
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=4B4911EC.1050102@intrepid.com \
--to=nenad@intrepid.com \
--cc=gary@intrepid.com \
--cc=gcc@gcc.gnu.org \
--cc=jan.kratochvil@redhat.com \
/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).