Downloaded Boost 1.55, bootstrapped using:
./bootstrap.sh --prefix=/usr/local/boost155 cxxflags="-arch i386 -arch x86_64" \
address-model=32_64 threading=multi macos-version=10.8 stage
Built using:
./b2 threading=multi link=static runtime-link=static \
cxxflags="-stdlib=libstdc++" linkflags="-stdlib=libstdc++"
Yields in libboost_chrono.a:
U std::string::_Rep::_M_destroy(std::allocator<char> const&)
U std::string::_Rep::_S_empty_rep_storage
U std::string::append(char const*, unsigned long)
U std::string::append(std::string const&)
U std::string::assign(char const*, unsigned long)
U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)
U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&)
Which implies that the library was built with the option -stdlib=libstdc++ - i.e. it's linked against the gnu version of the C++ runtime.
We purge the build using:
find . -name \*.o -print0 | xargs -0 rm
find . -name \*.a -print0 | xargs -0 rm
If we don't do that then it doesn't rebuild, and you end up with the same code as before. Next we build using:
./b2 threading=multi link=static runtime-link=static \
cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++"
Yields in libboost_chrono.a:
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::append(char const*)
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::append(char const*, unsigned long)
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::assign(char const*)
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::basic_string(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()
Which implies that it's built against libc++.
This can be verified by using a simple test c++ program (to indicate the linking):
#include <string>
int
main(int argc, char **argv)
{
std::string s("Hello World");
return 0;
}
$ make test
c++ test.cpp -o test
$ nm ./test | c++filt
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(char const*, unsigned long)
U std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()
$ rm test
$ make test CXXFLAGS=-stdlib=libstdc++
c++ -stdlib=libstdc++ test.cpp -o test
$ nm ./test | c++filt
U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)
U std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()
so yes, it's compiling with the relevant flag. What it does indicate that you have to pass the -stdlib=libstdc++ to everything you're compiling if you're using XCode 5 as it now defaults to using -stdlib=libc++. This means that any C++ based libraries that depend on c++ stdlib that you depend on also have to be compiled with the same flag.
Be careful with an incremental build of boost - if you don't purge the .o and .a files, they don't get recompiled based on the changed flags, which keeps the files as compiled, so if they were miscompiled then you encounter the problem.
