...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Some platforms and compilers do not provide all the required functionality to have a fully functional Boost.DLL. Such compilers are mentioned in this section along with possible workarounds for those limitations.
Some versions of Android, MinGW
and ld
on Windows platform
fail to mix __dllexport__
and weak
attributes. This
leads us to situation, where we must explicitly specify translation unit
in which BOOST_DLL_ALIAS
is
instantiated, making all other BOOST_DLL_ALIAS
declarations with that alias name an extern
variable.
Unit that must hold an instance of BOOST_DLL_ALIAS
must define BOOST_DLL_FORCE_ALIAS_INSTANTIATION
before including any of the Boost.DLL library headers.
You may explicitly disable export of weak symbols using BOOST_DLL_FORCE_NO_WEAK_EXPORTS
.
This may be usefull for working around linker problems or to test your program
for compatability with linkers that do not support exporting weak symbols.
Some platforms ignore section attributes, so that querying for a symbols
in a specified section using boost::dll::library_info
may return nothing.
On some platforms dlopen
,dlclose
and some other functions assume
that they won't be called concurrently.
Platforms that certaly have that issue are FreeBSD, MacOS, iOS.
Platforms that certaly do not have such issue are Windows, Linux+glibc, Android, QNX.
Other platforms are under question. If you're using one of the platforms
that are not listed (for example Linux+busybox), you may run the shared_library_concurrent_load_test
test
to detect the issue:
cd boost_folder/libs/dll/test ../../../b2 -a shared_library_concurrent_load_test
If a function is defined inside the class-definition it may be interpreted as always-inline which can lead to the function not being exported at all. This does however differ between between compilers.