Compiling a library (redland) in Cygwin using gcc and using the output in Visual Studio (c++)

Question

I'm currently trying to compile redland (librdf http://librdf.org/) under Windows. According to their website it should build under Windows. As i don't want to spend my time fixing the .sln I thought about compiling librdf (and the necessary projects) in cygwin and then use the library in visual studio.

So my question is: Is it possible to use librarys compile in cygwin in windows application? And if so how?

As I am a windows developer I don't know if there is any difference from the created .a files to .dlls. I already read up to the topic and it will be necessary to include the cygwin1.dll in the project but this won't be a problem.

Or does anyone have any better idea how I can get redland compiled as windows dlls? I thought about using mingw but until now I didn't manage to compile it.

Any help will be appreciated.

Thanks

Update:

Thanks to the help of Yaakov (And his pretty cool cygwin ports) I meanwhile managed to compile raptor (which is a prerequisite for librdf). All I had to do was include another argument for configure: --with-xml2-config=/usr/x86_64-w64-mingw32/sys-root/mingw/bin/xml2-config

Now I'm trying to compile rasqal which is another requesite and is also depending on raptor2. For it to work I had to export PKG_CONFIG_PATH="/usr/x86_64-w64-mingw32/sys-root/mingw/lib/pkgconfig/" for pkg-config to find the correct raptor installation.

So configure for rasqal worked but when I try to make it I get the following error:

Making all in src
make[1]: Entering directory `/home/Stefan/workspace/rasqal/src'
make  all-am
make[2]: Entering directory `/home/Stefan/workspace/rasqal/src'
/bin/sh ../libtool  --tag=CC    --mode=compile x86_64-w64-mingw32-gcc -DHAVE_CONFIG_H  -I.   -DRASQAL_INTERNAL=1   -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/raptor2       -g -O2   -DMTWIST_CONFIG -I../libmtwist -g -O2 -MT rasqal_algebra.lo -MD -MP -MF .deps/rasqal_algebra.Tpo -c -o rasqal_algebra.lo rasqal_algebra.c
libtool: compile:  x86_64-w64-mingw32-gcc -DHAVE_CONFIG_H -I. -DRASQAL_INTERNAL=1 -I/usr/x86_64-w64-mingw32/sys-root/mingw/include/raptor2 -g -O2 -DMTWIST_CONFIG -I../libmtwist -g -O2 -MT rasqal_algebra.lo -MD -MP -MF .deps/rasqal_algebra.Tpo -c rasqal_algebra.c  -DDLL_EXPORT -DPIC -o .libs/rasqal_algebra.o
In file included from /usr/x86_64-w64-mingw32/sys-root/mingw/include/sys/time.h:10:0,
                 from rasqal.h:116,
                 from rasqal_algebra.c:39:
/usr/x86_64-w64-mingw32/sys-root/mingw/include/time.h:260:8: error: redefinition of 'struct timezone'
./win32_rasqal_config.h:62:8: note: originally defined here
Makefile:1045: recipe for target `rasqal_algebra.lo' failed
make[2]: *** [rasqal_algebra.lo] Error 1
make[2]: Leaving directory `/home/Stefan/workspace/rasqal/src'
Makefile:720: recipe for target `all' failed
make[1]: *** [all] Error 2
make[1]: Leaving directory `/home/Stefan/workspace/rasqal/src'
Makefile:484: recipe for target `all-recursive' failed
make: *** [all-recursive] Error 1

Which I can't get my head around I'm not really into cross compiling. Can someone point me into the right direction?

You're proceeding correctly; you've just come across a portability issue. There are now two sets of GCC-compatible headers and import libraries for Windows: mingw.org and mingw-w64. The latter is newer, more complete, and supports x64, but these differences may conflict with workarounds in packages originally designed to work with the former, and that seems to be the problem here. (I never said this was going to be _easy_.) I would start by removing the conflicting typedef in the `win32_rasqal_config.h` file and try continuing the build. — Yaakov, May 30 '13 at 21:35
`win32_rasqal_config.h` shouldn't be used when building under cygwin. Rather use the autotools-generated `rasqal_config.h`. — laalto, Jun 02 '13 at 19:57

score 7 · Answer 1 · answered May 29 '13 at 00:01

The MSVC and Cygwin runtimes are incompatible, so you cannot use a Cygwin-compiled binary within VS. However, you can use Cygwin to cross-compile a library for Windows, which for C libraries, should be compatible with VS. (C++ is very compiler-specific, particularly with symbol mangling, but IIRC these libraries are all in C.)

To get started, you need to install the mingw64-i686-gcc-core, mingw64-i686-headers, and mingw64-i686-runtime packages, plus all dependencies, via Cygwin's setup.exe installer. Then, beginning with the "bottom" of the dependency chain, build each library with e.g.:

./configure --prefix=/usr/i686-w64-mingw32/sys-root/mingw --host=i686-w64-mingw32

Then run make followed by make install. For Windows x64, substitute all the i686s above with x86_64.

Keep in mind that librdf has a lot of (sub)dependencies, but I don't remember now how many are optional. Some, but not all, of these are available from the Cygwin Ports repository; those should at least help you get started.

score 2 · Answer 2 · answered Jan 24 '18 at 17:40

I recommend you to build raptor2 using Visual Studio. I did this successfully for Visual Studio 2017 x64 this way:

Install libxml2 and libxslt

Open PowerShell:

git clone https://github.com/Microsoft/vcpkg
cd vcpkg
.\bootstrap-vcpkg.bat
.\vcpkg install libxml2:x64-windows
.\vcpkg install libxslt:x64-windows

Build raptor2

Download raptor: http://librdf.org/raptor/ (http://download.librdf.org/source/raptor2-2.0.15.tar.gz)

Change raptor2-2.015/CMakeLists.txt, line 258:

ADD_DEFINITIONS(-DHAVE_CONFIG_H)
->
ADD_DEFINITIONS(-DHAVE_CONFIG_H -DYY_NO_UNISTD_H)

change raptor2-2.015/src/CMakeLists.txt, line 118:

ADD_LIBRARY(raptor2
    raptor_avltree.c
    ...
->
ADD_LIBRARY(raptor2
    raptor_escaped.c
    sort_r.c
    raptor_ntriples.c
    raptor_avltree.c
    ...

open cmake: set LIBXML2_INCLUDE_DIR to: path/to/vcpkg/installed/x64-windows/include set LIBXML2_LIBRARIES to: path/to/vcpkg/installed/x64-windows/lib/libxml2.lib

set LIBXSLT_INCLUDE_DIR to: path/to/vcpkg/installed/x64-windows/include
set LIBXSLT_LIBRARIES to: path/to/vcpkg/installed/x64-windows/lib/libxlst.lib
set LIBXSLT_EXSLT_LIBRARY to: path/to/vcpkg/installed/x64-windows/lib/libexlst.lib

Deployment:

Set CMAKE_INSTALL_PREFIX to your deplyoment path e.g. C:\thirdparty\vs2017\x64\raptor2

Execute the INSTALL target in Visual Studio.

If you do not like to execute this steps manually you can just download a prebuild version here.

Compiling a library (redland) in Cygwin using gcc and using the output in Visual Studio (c++)

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