id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
11671,explicit template instanciations in boost::serialization don't get exported with all compilers,Frederic Devernay <frederic.devernay@…>,Robert Ramey,"* Symptoms:

my program (compiled with g++-4.2.1 on OS X 10.6) crashed at run-time with:
{{{
dyld: lazy symbol binding failed: Symbol not found: __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
}}}

also reported (by someone else) at:
h__ps://trac.macports.org/ticket/48717

* Diagnostic:

not all compiler export the template instanciations when the template class is exported but not the template argument (in this case, std::ostream).

g++-4.0 and g++-4.8 do, g++-4.2 and clang++-3.4 don't.

{{{
$ g++-4.0 -dynamic -fPIC -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_SERIALIZATION_DYN_LINK=1 -I""."" -c -o ""basic_text_oprimitive.o"" ""libs/serialization/src/basic_text_oprimitive.cpp"" && nm -m basic_text_oprimitive.o|fgrep __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
000003c2 (__TEXT,__text) external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
00002d40 (__TEXT,__eh_frame) external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev.eh
$ g++-4.2 -dynamic -fPIC -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_SERIALIZATION_DYN_LINK=1 -I""."" -c -o ""basic_text_oprimitive.o"" ""libs/serialization/src/basic_text_oprimitive.cpp"" && nm -m basic_text_oprimitive.o|fgrep __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
000006d8 (__TEXT,__text) private external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
00003bf8 (__TEXT,__eh_frame) private external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev.eh
$ g++-mp-4.8 -dynamic -fPIC -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_SERIALIZATION_DYN_LINK=1 -I""."" -c -o ""basic_text_oprimitive.o"" ""libs/serialization/src/basic_text_oprimitive.cpp"" && nm -m basic_text_oprimitive.o|fgrep __ZN5boost7archive21basic_text_oprimitiveISoED2Ev000004dc (__TEXT,__text) external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
$ clang++-mp-3.4 -dynamic -fPIC -fvisibility=hidden -DBOOST_ALL_NO_LIB=1 -DBOOST_SERIALIZATION_DYN_LINK=1 -I""."" -c -o ""basic_text_oprimitive.o"" ""libs/serialization/src/basic_text_oprimitive.cpp"" && nm -m basic_text_oprimitive.o|fgrep __ZN5boost7archive21basic_text_oprimitiveISoED2Ev00000c70 (__TEXT,__textcoal_nt) weak private external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev
00003944 (__TEXT,__eh_frame) weak private external __ZN5boost7archive21basic_text_oprimitiveISoED2Ev.eh
}}}

* Related GCC bugs :

h__ps://gcc.gnu.org/bugzilla/show_bug.cgi?id=17470
h__ps://gcc.gnu.org/bugzilla/show_bug.cgi?id=51930

* Solutions :
  - adding `BOOST_SYMBOL_VISIBLE` (or the equivalent `#pragma GCC visibility`) to the template instantiation only solved the problem for clang-3.4.
  - adding `#pragma GCC visibility push(default)/#pragma GCC visibility pop` around `#include <ostream>` solved the problem for all compilers.

I do not know the side-effects of that second solution, but it seems like it is the only consistent one. All classes that are template arguments should be visible.

Maybe other compilers have the same issue.
",Bugs,closed,To Be Determined,serialization,Boost 1.59.0,Problem,fixed,,frederic.devernay@…