Date: Sun, 21 Feb 2016 11:42:22 +0100 From: Willem Jan Withagen <wjw@digiware.nl> To: Dimitry Andric <dim@FreeBSD.org> Cc: FreeBSD Toolchain <freebsd-toolchain@freebsd.org> Subject: Re: Ceph compilation on inclusion of /usr/include/c++/v1/deque Message-ID: <56C9948E.60509@digiware.nl> In-Reply-To: <56C8C2D1.9070603@digiware.nl> References: <56C88191.7030801@digiware.nl> <FF4EAE21-82C5-4105-8AED-993C6F3B2F7B@FreeBSD.org> <56C8C2D1.9070603@digiware.nl>
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On 20-2-2016 20:47, Willem Jan Withagen wrote: > On 20-2-2016 16:50, Dimitry Andric wrote: >> On 20 Feb 2016, at 16:09, Willem Jan Withagen <wjw@digiware.nl> wrote: >>> >>> I'm trying to build a port of Ceph for FreeBSD, which is sort of trying >>> to shoot at a tank with a watergun.... :) >> >> This is very nice, it would be good to have Ceph on FreeBSD. Note that >> if you have problems with porting, usually the freebsd-ports mailing >> list is a better audience. >> >> >>> I you want to reproduce it is rather labourious, but not all that complex: >>> git clone https://github.com/wjwithagen/ceph.git >>> cd ceph >>> git checkout wip-wjw-freebsd-tests >>> ./do_freebsd.sh >>> >>> And wait for the error to appear. >> ... >>> /usr/include/c++/v1/deque:912:49: error: invalid application of 'sizeof' >>> to an incomplete type 'value_type' (aka 'RGWPeriod') >>> static const difference_type __block_size = sizeof(value_type) < 256 >>> ? 4096 / sizeof(value_type) : 16; >>> ^~~~~~~~~~~~~~~~~~ >>> /usr/include/c++/v1/deque:1159:15: note: in instantiation of template >>> class 'std::__1::__deque_base<RGWPeriod, >>> std::__1::allocator<RGWPeriod> >' requested here >>> : private __deque_base<_Tp, _Allocator> >>> ^ >>> rgw/rgw_period_history.h:26:27: note: in instantiation of template class >>> 'std::__1::deque<RGWPeriod, std::__1::allocator<RGWPeriod> >>>> ' requested here >>> std::deque<RGWPeriod> periods; >>> ^ >>> rgw/rgw_period_history.h:16:7: note: forward declaration of 'RGWPeriod' >>> class RGWPeriod; >>> ^ >> >> Without having to build anything, I see the problem already. :) The >> error message is unfortunately rather confusing, but the gist of it is >> that the implementation of std::deque<> requires a complete type. >> >> Which means that you cannot do this: >> >> #include <deque> >> class foo; >> std::deque<foo> bar; >> >> Compiling this example with clang and libc++ will result in (not all >> errors shown, no need to): >> >> In file included from deque-test.cpp:1: >> /usr/include/c++/v1/deque:912:49: error: invalid application of 'sizeof' to an incomplete type 'value_type' (aka 'foo') >> static const difference_type __block_size = sizeof(value_type) < 256 ? 4096 / sizeof(value_type) : 16; >> ^~~~~~~~~~~~~~~~~~ >> /usr/include/c++/v1/deque:1159:15: note: in instantiation of template class 'std::__1::__deque_base<foo, std::__1::allocator<foo> >' requested here >> : private __deque_base<_Tp, _Allocator> >> ^ >> deque-test.cpp:3:17: note: in instantiation of template class 'std::__1::deque<foo, std::__1::allocator<foo> >' requested here >> std::deque<foo> bar; >> ^ >> deque-test.cpp:2:7: note: forward declaration of 'foo' >> class foo; >> ^ >> >> Similarly, compiling the example with g++ and libstdc++ (6.0.0 from >> ports) results in: >> >> In file included from /usr/local/lib/gcc6/include/c++/deque:64:0, >> from deque-test.cpp:1: >> /usr/local/lib/gcc6/include/c++/bits/stl_deque.h: In instantiation of 'void std::_Deque_base<_Tp, _Alloc>::_M_initialize_map(std::size_t) [with _Tp = foo; _Alloc = std::allocator<foo>; std::size_t = unsigned int]': >> /usr/local/lib/gcc6/include/c++/bits/stl_deque.h:490:26: required from 'std::_Deque_base<_Tp, _Alloc>::_Deque_base() [with _Tp = foo; _Alloc = std::allocator<foo>]' >> /usr/local/lib/gcc6/include/c++/bits/stl_deque.h:884:23: required from 'std::deque<_Tp, _Alloc>::deque() [with _Tp = foo; _Alloc = std::allocator<foo>]' >> deque-test.cpp:3:17: required from here >> /usr/local/lib/gcc6/include/c++/bits/stl_deque.h:682:74: error: invalid application of 'sizeof' to incomplete type 'foo' >> const size_t __num_nodes = (__num_elements/ __deque_buf_size(sizeof(_Tp)) >> ^ >> /usr/local/lib/gcc6/include/c++/bits/stl_deque.h:713:31: error: invalid application of 'sizeof' to incomplete type 'foo' >> % __deque_buf_size(sizeof(_Tp))); >> ^ >> >> Looking at rgw_period_history.h, it is indeed using an incomplete type: >> >> #include <deque> >> #include <mutex> >> #include <system_error> >> #include <boost/intrusive/avl_set.hpp> >> #include "include/assert.h" >> #include "include/types.h" >> >> namespace bi = boost::intrusive; >> >> class RGWPeriod; >> >> /** >> * RGWPeriodHistory tracks the relative history of all inserted periods, >> * coordinates the pulling of missing intermediate periods, and provides a >> * Cursor object for traversing through the connected history. >> */ >> class RGWPeriodHistory final { >> /// an ordered history of consecutive periods >> struct History : public bi::avl_set_base_hook<> { >> std::deque<RGWPeriod> periods; >> >> E.g at this point, all the compiler has is a forward declaration of >> RGWPeriod. If this even compiles on Linux, I am unsure how it manages >> to do so. :-) Maybe the Linux build pulls in some other header first, >> getting the full definition of RGWPeriod somehow? >> >> In any case, the easiest fix is probably to switch around the inclusions >> of the headers in rgw_period_history.cc, e.g. changing: >> >> #include "rgw_period_history.h" >> #include "rgw_rados.h" >> >> to: >> >> #include "rgw_rados.h" >> #include "rgw_period_history.h" >> >> Since rgw_rados.h contains the full definition of RGWPeriod, the forward >> declaration on line 16 of rgw_period_history.h can then be deleted. >> >> Alternatively, include rgw_rados.h directly in rgw_period_history.h, >> which is what I would do. I am unsure how Ceph upstream thinks about >> that, though. Maybe you can check with them? > > Hi Dimitry, > > Thanx for all the advise. > It is going to take some time to absorbe all. :) > > I've got a FreeBSD pull running, and on and off I'm commented by other > committers as to how or why... You've given enough text to actually put > in the commit message. And we'll find out how they feel about it. > > As to running this by the ports list, I have not really seen any this > type of problem passing by there. Next to that I expected it more to be > GCC <> Clang because every commit is run through Jenkins compilation and > testing, and it would be noticed there. There were some more loop dependancies which required forward declaration and alter inclusion of include files. But in the end I got it to compile again. So thanx for the help. --WjW
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