Re: [Boost-build] Building for ARM926EJ-S

From: Vladimir Prus (vladimir_at_[hidden])
Date: 2008-04-02 10:52:20

On Wednesday 02 April 2008 13:50:42 Rob Desbois wrote:
> I've been trying to link against Boost libraries 1.35.0 built with
> CodeSourcery's ARM/GNU toolchain and have had no luck yet.
> 
> My user-config.jam contained the line:
>  using gcc :: arm-none-linux-gnueabi-gcc ;
> and I built the libraries with:
>  bjam --with-regex --with-serialization --with-thread stage
> 
> This worked fine, however when linking the test program from the
> 'Getting Started (Unix)' guide I get:
>  $ arm-none-linux-gnueabi-g++ test-regex.cpp -I.
> stage/lib/libboost_regex-gcc42-mt-1_35.so
>  /tmp/ccVow1Eq.o: In function `boost::detail::atomic_decrement(int*)':
>  test-regex.cpp:(.text._ZN5boost6detail16atomic_decrementEPi[boost::detail::atomic_decrement(int*)]+0x18):
> undefined reference to `__sync_fetch_and_add_4'
>  collect2: ld returned 1 exit status
> 
> As far as I could ascertain this has something to do with compiling
> for the incorrect architecture/cpu. 

I've just spoken with an ARM expert here at CodeSourcery, who tells me that
the atomic builtins, including __sync_fetch_and_add, are not supported
by GCC on ARM. 

What happens is that boost/detail/sp_counted_base.hpp has this code:

        #elif defined(__GNUC__) && ( __GNUC__ * 100 + __GNUC_MINOR__ >= 401 )
        
        # include <boost/detail/sp_counted_base_sync.hpp>

and sp_counted_base_sync.hpp has this:

        inline void atomic_increment( sp_int32_t * pw )
        {
            __sync_fetch_and_add( pw, 1 );
        }

and while this apparent compiles, it does not work. I suggest you report this
problem on the C++ Boost developers mailing list -- I think the #elif condition
need to explicitly check for ARM.

- Volodya