Re: [boost] [1_34_0] [python] gcc strict-aliasing warnings in release mode

From: Kim Barrett (kab_at_[hidden])
Date: 2007-05-01 15:42:05

At 7:40 AM -0400 5/1/07, David Abrahams wrote:
>on Sat Apr 28 2007, Kim Barrett <kab-AT-irobot.com> wrote:
>
>>  At 2:02 AM -0400 4/27/07, Kim Barrett wrote:
>>>   There are several occurrences of
>>>
>  >>      "dereferencing type-punned pointer will break strict aliasing rules"
>>
>I would, however, appreciate it very much if
>you'd put your patch into the SF patch tracker so it can be applied
>for 1.35

I don't think you would like my patch, which consists of adding the line

   flags gcc.compile OPTIONS : -fno-strict-aliasing ;

to tools/build/v2/tools/gcc.jam, turning off strict-aliasing globally for
all of building boost with any version of gcc. I spent a little bit of
time failing to figure out how to narrow the scope of the option to either
more limited versions of gcc (I think the option doesn't show up until
somewhere around 3.2 / 3.3) or limit it to only boost.python, but since
I don't actually need either of those I eventually punted.

I did file a bug report, so that you have a reminder that something needs
to be done: bug 1710770: gcc strict-aliasing problems with python. And I'm
happy to help out with fixing / testing / reviewing, just don't know enough
bjam. There may be some documentation changes needed to, though I note
that the 1.33.1 documentation regarding building extension modules just
refers to using either Boost.Build or looking at the options it would use.