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Type:
Bug
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Resolution: Done
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Priority:
Blocker - P1
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Affects Version/s: 3.0.0
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Component/s: Portability
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Labels:
The driver fails to build on FreeBSD with the following errors:
[ 4%] Building CXX object src/bsoncxx/CMakeFiles/bsoncxx.dir/types/value.cpp.o
In file included from /home/karrotkake/mongo-cxx-driver/src/bsoncxx/types/value.cpp:48:
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/enums/type.hpp:20:1: error: static_assert failed "Copy may throw"
BSONCXX_ENUM(utf8, 0x02)
^~~~~~~~~~~~~~~~~~~~~~~~
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/types/value.cpp:36:9: note: expanded from macro 'BSONCXX_ENUM'
static_assert(std::is_nothrow_copy_constructible<b_##name>::value, "Copy may throw"); \
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/karrotkake/mongo-cxx-driver/src/bsoncxx/types/value.cpp:48:
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/enums/type.hpp:31:1: error: static_assert failed "Copy may throw"
BSONCXX_ENUM(code, 0x0D)
^~~~~~~~~~~~~~~~~~~~~~~~
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/types/value.cpp:36:9: note: expanded from macro 'BSONCXX_ENUM'
static_assert(std::is_nothrow_copy_constructible<b_##name>::value, "Copy may throw"); \
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /home/karrotkake/mongo-cxx-driver/src/bsoncxx/types/value.cpp:48:
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/enums/type.hpp:32:1: error: static_assert failed "Copy may throw"
BSONCXX_ENUM(symbol, 0x0E)
^~~~~~~~~~~~~~~~~~~~~~~~~~
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/types/value.cpp:36:9: note: expanded from macro 'BSONCXX_ENUM'
static_assert(std::is_nothrow_copy_constructible<b_##name>::value, "Copy may throw"); \
^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3 errors generated.
*** [src/bsoncxx/CMakeFiles/bsoncxx.dir/types/value.cpp.o] Error code 1
Interesting that BSON types b_symbol, b_code and b_utf8 fail nothrow requirement of the constructor. The fix I applied in this case is to rewrite "bsoncxx/types/value.cpp:32"
#if !defined(BSONCXX_POLY_USE_BOOST)
as
#if defined(BSONCXX_POLY_USE_BOOST)
Another error relates to failure of the Clang to select and appropriate overloaded function when using chrono::count(), here's an error example for modify_collection.cpp (it fails also on collection.cpp, basically anywhere append() is called with chrono::count()):
[ 20%] Building CXX object src/mongocxx/CMakeFiles/mongocxx.dir/options/modify_collection.cpp.o
In file included from /home/karrotkake/mongo-cxx-driver/src/mongocxx/options/modify_collection.cpp:17:
In file included from /home/karrotkake/mongo-cxx-driver/src/bsoncxx/builder/stream/document.hpp:18:
In file included from /home/karrotkake/mongo-cxx-driver/src/bsoncxx/builder/stream/key_context.hpp:19:
/home/karrotkake/mongo-cxx-driver/src/bsoncxx/builder/stream/value_context.hpp:70:16: error: call to member
function 'append' is ambiguous
_core->append(std::forward<T>(t));
~~~~~~~^~~~~~
/home/karrotkake/mongo-cxx-driver/src/mongocxx/options/modify_collection.cpp:38:55: note: in instantiation of
function template specialization
'bsoncxx::v_noabi::builder::stream::value_context<bsoncxx::v_noabi::builder::stream::key_context<bsoncxx::v_noabi::builder::stream::closed_context>
>::operator<<<long long>' requested here
<< "expireAfterSeconds" << seconds.count() << finalize);
The problem comes from the fact that libc++ <chrono> defines seconds, milliseconds etc. as:
typedef duration<long long, milli> milliseconds; typedef duration<long long > seconds;
But append() accepts int32_t, int64_t etc., and int64_t is defined in system <stdint.h> header as
typedef long int64_t
So compiler fails during overload resolutio to select correct version of append(), because chrono::count() returns long long which, supposedly, can match into both append(int32_t) and append(int64_t).
Also here's the include hierarchy of Clang's (libc++) <cstdint> header:
. /usr/include/c++/v1/cstdint .. /usr/include/c++/v1/__config ... /usr/include/sys/endian.h .... /usr/include/sys/cdefs.h .... /usr/include/sys/_types.h ..... /usr/include/machine/_types.h ...... /usr/include/x86/_types.h