Re: [Boost-bugs] [Boost C++ Libraries] #7093: Building "system" segfaults on AIX 6.1 / vacpp

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #7093: Building "system" segfaults on AIX 6.1 / vacpp
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-03-09 00:45:50

#7093: Building "system" segfaults on AIX 6.1 / vacpp
----------------------------------------------------+-----------------------
  Reporter:  Martin Baute <solar@…>                 |       Owner:  vladimir_prus
      Type:  Bugs                                   |      Status:  new          
 Milestone:  To Be Determined                       |   Component:  build        
   Version:  Boost 1.50.0                           |    Severity:  Regression   
Resolution:                                         |    Keywords:  aix          
----------------------------------------------------+-----------------------

Comment (by steven_watanabe):

 I've found the culprit.  As I suspected, it's in list_sublist.

 {{{
 837     __L830:                                 # 0x00000830
 (H.10.NO_SYMBOL+0x830)
 838             neg        r3,r0
 839             addi       r0,r28,4
 840             stw        r30,0(r6)
 841             or         r7,r6,r3
 842             lwz        r3,0(r6)
 843             stwx       r3,r5,r4
 }}}

 {{{
 line 34(list_alloc):       freelist[ bucket ] = result->next;
 line 171(list_copy_range): result->impl.size = size
 }}}

 result is the same pointer in both functions.  This is reordered to

 {{{
 result->impl.size = size;
 freelist[ bucket ] = result->next;
 }}}

 which is equivalent to

 {{{
 result->impl.size = size;
 freelist[ bucket ] = (struct freelist_node*)size;
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/7093#comment:13>
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