Re: [Boost-users] undefined reference to `__sync_fetch_and_add_4'

Subject: Re: [Boost-users] undefined reference to `__sync_fetch_and_add_4'
From: Peter Dimov (pdimov_at_[hidden])
Date: 2009-04-24 12:49:18

Birju Prajapati:

> g++ -m32 [...]

> /usr/local/lib32/libboost_serialization-gcc43-mt.so: undefined reference 
> to `__sync_fetch_and_add_4'

This is weird. __sync_fetch_and_add is used by shared_ptr and atomic_count, 
but in both places, the earlier

#elif defined( __GNUC__ ) && ( defined( __i386__ ) || defined( 
__x86_64__ ) )

takes precedence, and I have verified that g++ -m32 does indeed define 
__i386__.

This could be caused by an issue we've identified recently of libstdc++ 
standard headers using __sync_fetch_and_add as part of their reference 
counted implementation of std::string and std::locale.