Error building with Visual Studio 2017

[Alberto Bignotti]

git clone git@…:libgeos/geos.git

commit id: 6998041 (done on 11 Jul 2019 16:54)

generating project for Visual Studio 2017 x64

-DBUILD_SHARED_LIBS=ON

Build of "geos" project fail with this log:

...
2>C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.16.27023\include\map(82): note: see reference to class template instantiation 'std::_Tree<std::_Tmap_traits<_Kty,_Ty,_Pr,_Alloc,false>>' being compiled
2>        with
2>        [
2>            _Kty=std::string,
2>            _Ty=std::unique_ptr<geos::util::Profile,std::default_delete<geos::util::Profile>>,
2>            _Pr=std::less<std::string>,
2>            _Alloc=std::allocator<std::pair<const std::string,std::unique_ptr<geos::util::Profile,std::default_delete<geos::util::Profile>>>>
2>        ]
2>C:\dev_qt\experiments\last\build_geos\geos\include\geos/profiler.h(166): note: see reference to class template instantiation 'std::map<std::string,std::unique_ptr<geos::util::Profile,std::default_delete<_Ty>>,std::less<_Kty>,std::allocator<std::pair<const _Kty,std::unique_ptr<_Ty,std::default_delete<_Ty>>>>>' being compiled
2>        with
2>        [
2>            _Ty=geos::util::Profile,
2>            _Kty=std::string
2>        ]
2>math.cpp
2>Generating Code...
2>Done building project "geos.vcxproj" -- FAILED.
========== Build: 1 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

this happend in classes:

geos::operation::distance::ConnectedElementLocationFilter
geos::util::Profiler

When Visual Studio needs to export a class in a DLL, it instantiates everything possible. It will also try to create a copy constructor and copy assignment operator if they are not explicitly deleted. Unfortunately, the member variables

geos::operation::distance::ConnectedElementLocationFilter::locations
geos::util::Profiler::profs

cannot be copied because of the unique pointer. So when it tries to export the class, it fails.

To solve I added this:

class GEOS_DLL Profiler {

public:
...
    Profiler(const Profiler&) = delete;
    Profiler& operator=(const Profiler&) = delete;
...
};

class GEOS_DLL ConnectedElementLocationFilter: public geom::GeometryFilter {
private:
...
    ConnectedElementLocationFilter(const ConnectedElementLocationFilter&) = delete;
    ConnectedElementLocationFilter& operator=(const ConnectedElementLocationFilter&) = delete;
...
}

[Alberto Bignotti]

There are something more in order to build unit tests:

geos\include\geos\geom\Location.h add GEOS_DLL before

std::ostream& operator<<(std::ostream& os, const Location& loc);

Correct version:

GEOS_DLL std::ostream& operator<<(std::ostream& os, const Location& loc);

geos\include\geos\geom\Geometry.h add missing GEOS_DLL:

std::string GEOS_DLL geosversion();
std::string GEOS_DLL jtsport();

With previous fix and this I'm able to run succesfully the test suite.

[dbaston]

Alberto, can you provide these changes as a pull request (​https://github.com/libgeos/geos/) ?

[hobu]

PR made in ​https://github.com/libgeos/geos/pull/226 but I have no idea why drony is whining.

[Paul Ramsey <pramsey@…>]

In 1df959c/git:

Fix MSVC 2017 compilation, from @hobu.
References #975