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Subject: [Bug debug/53927] wrong value for DW_AT_static_link
Date: Thu, 24 Jan 2013 20:25:00 -0000
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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.