[boost] Fw: shared_array EXC_BAD_ACCESS

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-08-02 06:22:05

I'm forwarding the following post from boost-users

http://lists.boost.org/boost-users/2005/08/12938.php

since it describes a pretty severe configuration problem on Mac OS X that 
apparently leads to inconsistent definitions of BOOST_HAS_THREADS and all 
kinds of interesting ODR violations.

Christopher Hunt wrote:
> OK, this is now completely solved. :-)
>
> Interestingly, boost/detail/lightweight_mutex.hpp was being included
> in one place and declaring lightweight_mutex from
> boost/detail/lwm_nop.hpp. However the implementation from
> boost/detail/lwm_pthreads.hpp was actually being used.
>
> To cut a long story short, declaring a prefix file that forced boost
> to configure itself prior to importing Cocoa and Carbon dependencies
> completely solved the problem. Here's what my Cocoa pch file looks
> like:
>
> //
> // Prefix header for all source files
> //
>
> #ifdef __cplusplus
>     #include <boost/config.hpp>
>                                 // Gets brought in early so that any
> Carbon presence doesn't influence
>                                 // its configuration.
> #endif
>
> #ifdef __OBJC__
>     #import <Cocoa/Cocoa.h>
> #endif
>
> If you're doing just Carbon, then do your #include <Carbon/Carbon.h>
> after boost/config.hpp is included (in place of the #ifdef __OBJC__
> block).
>
> The real gremlin here is this bit of code in
> boost/config/platform/macos.hpp:
>
> #  ifndef TARGET_CARBON
> #     include <boost/config/posix_features.hpp>
> #  endif
>
> There is a posting that discusses the rationale of the above:
> http://lists.boost.org/boost-users/2004/10/8110.php and also makes the
> observation that there's probably a better way to check for MSL.
>
> My recommendation is to check for the definition of __MSL__. Thus the
> above code becomes:
>
> #  ifndef __MSL__
> #     include <boost/config/posix_features.hpp>
> #  endif
>
> IMHO the existing MSL check is a bug (checking TARGET_CARBON is too
> broad) and will be a trap for all Cocoa/Carbon programmers wanting to
> use boost. I would also think that the reality now is that most people
> use xcode/gcc and not CodeWarrior/MSL (this is from someone who used
> to use CW and MSL all the time). Thus, the motivation for addressing
> the issue should now be high.
>
> What needs to be done to fix the problem? I'm willing to help to save
> some other poor soul from spending a day or two stuffing around.
>
> Cheers,
> -C