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From: "tromey at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug debug/53927] wrong value for DW_AT_static_link
Date: Thu, 24 Jan 2013 20:25:00 -0000	[thread overview]
Message-ID: <bug-53927-4-9CldplYZkp@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-53927-4@http.gcc.gnu.org/bugzilla/>


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53927

--- Comment #1 from Tom Tromey <tromey at gcc dot gnu.org> 2013-01-24 20:24:18 UTC ---
It seems that I read the wrong frame info in my original report.
However, the bug still exists.  Here is a new and hopefully more
correct example showing the bug.

I used a relatively recent git master gcc for this.
I just followed the directions in the original report.

The static link info for 'nested':

    <aa>   DW_AT_static_link : 1 byte block: 50     (DW_OP_reg0 (rax))

In the 'nested' frame this is:

(gdb) p/x $rax
$1 = 0x7fffffffe370

In the outer 'nestee' frame:

(gdb) p $pc
$2 = (void (*)()) 0x4004e9 <nestee+99>

The frame info as shown by readelf --debug-dump=frames-interp:

00000060 00000024 00000064 FDE cie=00000000 pc=00400486..004004fe
   LOC           CFA      rbx   rbp   ra      
0000000000400486 rsp+8    u     u     c-8   
0000000000400487 rsp+16   u     c-16  c-8   
000000000040048a rbp+16   u     c-16  c-8   
000000000040048f rbp+16   c-24  c-16  c-8     <--- this row
00000000004004fd rsp+8    c-24  c-16  c-8   


So the CFA we want is $rbp + 16 in the outermost 'nestee' frame:

(gdb) p/x $rbp + 16
$3 = 0x7fffffffe3b0

... but this is different from $1.


  reply	other threads:[~2013-01-24 20:25 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-11 13:20 [Bug debug/53927] New: " tromey at gcc dot gnu.org
2013-01-24 20:25 ` tromey at gcc dot gnu.org [this message]
2013-01-31 15:01 ` [Bug debug/53927] " ebotcazou at gcc dot gnu.org
2013-01-31 19:23 ` jason at gcc dot gnu.org
2013-01-31 19:40 ` tromey at gcc dot gnu.org
2013-01-31 20:12 ` jason at gcc dot gnu.org
2013-01-31 22:34 ` ebotcazou at gcc dot gnu.org
2013-01-31 23:23 ` jason at gcc dot gnu.org
2013-02-01 18:22 ` tromey at gcc dot gnu.org
2013-02-01 22:17 ` ebotcazou at gcc dot gnu.org
2013-02-01 22:21 ` ebotcazou at gcc dot gnu.org
2014-05-09 16:14 ` ebotcazou at gcc dot gnu.org
2014-06-06  8:14 ` ebotcazou at gcc dot gnu.org
2015-02-25 15:02 ` derodat at adacore dot com
2015-02-25 15:03 ` derodat at adacore dot com
2015-03-02 14:42 ` derodat at adacore dot com
2015-03-02 14:59 ` tromey at gcc dot gnu.org
2015-03-03 10:02 ` derodat at adacore dot com
2015-03-03 11:03 ` ebotcazou at gcc dot gnu.org
2015-03-03 15:13 ` tromey at gcc dot gnu.org
2015-03-09 15:56 ` derodat at adacore dot com
2015-03-10  9:41 ` ebotcazou at gcc dot gnu.org

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