Failed to build czmq on Windows via CMake

[myd7349]

Hey, guys! I am back again.

I am trying to add czmq to vcpkg these days(microsoft/vcpkg#4979). When building czmq with CMake, I encountered several problems.

1. CMAKE_CURRENT_SOURCE_DIR isn't in CMAKE_MODULE_PATH.

   https://github.com/zeromq/czmq/blob/master/CMakeLists.txt#L19

   so Findlibzmq.cmake, Findlibsodium.cmake, .etc. may not be called.

2. When built as a static library, libzmq will set an additional compiler flag -DZMQ_STATIC through set_target_properties:

   https://github.com/zeromq/libzmq/blob/master/CMakeLists.txt#L1060

   so if we want to build czmq as a static library on Windows, we should define ZMQ_STATIC manually(Maybe we can define it in Findlibzmq.cmake). Otherwise, the build will fail: undefined reference in mingw when link static library. libzmq#3318

3. Findlibzmq.cmake is not be able to find libzmq on Windows.

   libzmq dll/lib built with MSVC is named using the Boost convention(something like libzmq-mt-4_3_1.lib, libzmq-mt-4_3_1.dll). So find_library (LIBZMQ_LIBRARIES NAMES zmq HINTS ${PC_LIBZMQ_LIBRARY_HINTS}) will not work.

   Here is a patch for solving this problem: https://bitbucket.org/ignitionrobotics/ign-transport/pull-requests/19/detec-zmq-under-windows-using-a-findzmq/diff

4. Findlibsodium.cmake will not found libsodium on Windows

   When built with MSVC, libsodium will generate a library named libsodium.dll/lib. In this case, find_library(LIBSODIUM_LIBRARY NAMES sodium) is not able to find the library. I found that find_library(LIBSODIUM_LIBRARY NAMES sodium libsodium) works.

   By the way, Findlibcurl.cmake has this problem too.

5. Maybe we can add some options like:

   WITH_LIBSODIUM
WITH_LIBCURL
WITH_LZ4
WITH_UUID
BUILD_TESTS (For example: Create a configuration flag to disable tests. googleapis/google-cloud-cpp#1617)
   BUILD_TOOLS (zmakecret)

[ras0219-msft]

We can (and should) fix (2) upstream in vcpkg by encoding ZMQ_STATIC into the zmq headers.

You don't need to add BUILD_TESTS option. include(CTest) automatically calls enable_testing() and creates a BUILD_TESTING option for you. Depending on how you've structured your CMakeLists, you may need to wrap certain blocks in IF (BUILD_TESTING).

[myd7349]

@ras0219-msft Just like this?

if(VCPKG_LIBRARY_LINKAGE STREQUAL "static")
    file(READ ${CURRENT_PACKAGES_DIR}/include/zmq.h _contents)
    string(REPLACE "defined ZMQ_STATIC" "1 //defined ZMQ_STATIC" _contents "${_contents}")
    file(WRITE ${CURRENT_PACKAGES_DIR}/include/zmq.h "${_contents}")
endif()

I am considering to add these line to zeromq/portfile.cmake through microsoft/vcpkg#4214.

@remyabel Thanks for telling me that. :-)

[bluca]

Note that libsodium is not a dependency of CZMQ, so there's no need for an option for it

[stale]

This issue has been automatically marked as stale because it has not had recent activity for 90 days. It will be closed if no further activity occurs within 21 days. Thank you for your contributions.

[myd7349]

Do not close yet. I'd like to tackle this issue.

[myd7349]

A quick fix of this problem:

First, build and install libzmq on Windows:

cd libzmq
mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=C:/libzmq
cmake --build . --target install

Then, clone czmq and replace Findlibzmq.cmake with this one: https://github.com/myd7349/Ongoing-Study/blob/master/cpp/CMake/find_libzmq_ng/Findlibzmq.cmake

cd czmq
mkdir build
cd build
cmake .. -DCMAKE_PREFIX_PATH=C:/libzmq

The CI configuration file has this line: https://github.com/zeromq/czmq/blob/master/appveyor.yml#L53
That is, it renames libs like libzmq-v141-mt-gd-4_3_2.lib to zmq.lib.

[myd7349]

Findlibzmq.cmake is generated by these code: https://github.com/zeromq/zproject/blob/master/zproject_cmake.gsl#L640-L697 via gsl -target:* project.xml.

[myd7349]

I think we may have three ways to fix the libzmq not found issue on Windows:

1. Remove <use project = "libzmq" /> from czmq/project.xml, and maintain Findlibzmq.cmake seperately. Then we can fix this problem by patching Findlibzmq.cmake manually.
2. Change these code https://github.com/zeromq/zproject/blob/master/zproject_cmake.gsl#L640-L697 to handle zmq specially so that a special version of Findlibzmq.cmake is generated like the one I gave above.
3. Prefer ZeroMQ's CMake target instead of Findlibzmq.cmake.
   ZeroMQ itself provides a CMake target(libzmq for a shared build, and libzmq-static for a static build). So we may consider replacing Findlibzmq.cmake with find_package(ZeroMQ CONFIG REQUIRED).
   This solution also require us to remove <use project = "libzmq" /> from czmq/project.xml, and then add find_package(ZeroMQ CONFIG REQUIRED) to this file: https://github.com/zeromq/zproject/blob/master/zproject_cmake.gsl

I personally think solution 3 is the best, since it uses modern cmake.

Update:
I noticed the existance of this #1939. So maybe I will fix this problem through solution 1 or 2.

[eplumer]

To close out on my question for #2004 which was redirected here I have attached the manual steps that I got working on my VS 2013 system. Thanks for pointing me to he appveyor.yml file for hints:

set ZMQ_ROOT=path_to_my_project_root
set CMAKE_GENERATOR="Visual Studio 12 2013 Win64"
set LIBZMQ_SOURCEDIR=%ZMQ_ROOT%\libzmq
set LIBZMQ_BUILDDIR=%LIBZMQ_SOURCEDIR%\BUILD
set CZMQ_SOURCEDIR=%ZMQ_ROOT%\czmq
set CZMQ_BUILDDIR=%CZMQ_SOURCEDIR%\BUILD

rmdir /s /q %LIBZMQ_BUILDDIR%
mkdir %LIBZMQ_BUILDDIR%
cd %LIBZMQ_BUILDDIR%

cmake -D CMAKE_CXX_FLAGS_RELEASE="/MT" -D CMAKE_CXX_FLAGS_DEBUG="/MTd" -G %CMAKE_GENERATOR% %LIBZMQ_SOURCEDIR%

C:\Progra~2\MSBuild\12.0\Bin\msbuild /v:minimal /maxcpucount:%NUMBER_OF_PROCESSORS% /p:Configuration=Release libzmq.vcxproj

C:\Progra~2\MSBuild\12.0\Bin\msbuild /v:minimal /maxcpucount:%NUMBER_OF_PROCESSORS% /p:Configuration=Debug libzmq.vcxproj

copy /Y %LIBZMQ_BUILDDIR%\lib\Release\libzmq-v120-mt-4_3_1.lib %LIBZMQ_BUILDDIR%\lib\Release\zmq.lib
copy /Y %LIBZMQ_BUILDDIR%\lib\Debug\libzmq-v120-mt-gd-4_3_1.lib %LIBZMQ_BUILDDIR%\lib\Debug\zmq.lib

rmdir /s /q %CZMQ_BUILDDIR%
mkdir %CZMQ_BUILDDIR%
cd %CZMQ_BUILDDIR%

cmake -G %CMAKE_GENERATOR% -D CMAKE_INCLUDE_PATH="%LIBZMQ_SOURCEDIR%\include" -D CMAKE_LIBRARY_PATH="%LIBZMQ_BUILDDIR%\lib\Release" -D CMAKE_C_FLAGS_RELEASE="/MT" -D CMAKE_CXX_FLAGS_RELEASE="/MT" -D CMAKE_C_FLAGS_DEBUG="/MTd" %CZMQ_SOURCEDIR%

Open Visual Studio 2013 and Rebuild "Release | x64" for "%CZMQ_BUILDDIR%\czmq.sln"

copy /Y %LIBZMQ_BUILDDIR%\bin\Release\libzmq-v120-mt-4_3_1.dll %CZMQ_BUILDDIR%\Release\

cmake -G %CMAKE_GENERATOR% -D CMAKE_INCLUDE_PATH="%LIBZMQ_SOURCEDIR%\include" -D CMAKE_LIBRARY_PATH="%LIBZMQ_BUILDDIR%\lib\Debug" -D CMAKE_C_FLAGS_RELEASE="/MT" -D CMAKE_CXX_FLAGS_RELEASE="/MT" -D CMAKE_C_FLAGS_DEBUG="/MTd" %CZMQ_SOURCEDIR%

Open Visual Studio 2013 and Rebuild "Debug | x64" for "%CZMQ_BUILDDIR%\czmq.sln"

copy /Y %LIBZMQ_BUILDDIR%\bin\Debug\libzmq-v120-mt-gd-4_3_1.dll %CZMQ_BUILDDIR%\Debug\
copy /Y %LIBZMQ_BUILDDIR%\bin\Debug\libzmq-v120-mt-gd-4_3_1.pdb %CZMQ_BUILDDIR%\Debug\