Compilation issue on Mingw32: redeclared without dllimport attribute

[zeromq]

Compilation issue on Mingw32: redeclared without dllimport attribute

[pijyoi]

How about if you configure --disable-static?

Update: I have tried
./configure --with-libzmq=/usr/local --disable-static
and the compilation of the dynamic library works but not for czmq_selftest.exe

The problem is that the *_test() functions called by czmq_selftest.c are not exported in the DLL.
I am not sure exporting the *_test() functions is the right thing to do either.

Could you please try again with the latest czmq and zmq? Or could
someone tell me the build process for cross compiling with mingw32?

[pijyoi]

I use the toolchain from http://mxe.cc and I create a folder $HOME/local_mingw32.

for libzmq:
CPPFLAGS=-DFD_SETSIZE=1024 ./configure --host=i686-pc-mingw32 --with-libsodium=$HOME/local_mingw32 --prefix=$HOME/local_mingw32

for czmq
./configure --host=i686-pc-mingw32 --with-libzmq=$HOME/local_mingw32 --prefix=$HOME/local_mingw32

Sometimes, there are changes in the source code that break compilation with MinGW32.
Mostly they arise from conflating "Windows platform" with "MSVC compiler".

[ulikoehler]

I think we need some kind of guide how to get MinGW+(C)ZMQ build working under wine, because the errors seem to occur somewhat frequently and it seems like most people (including me and Travis) are using pretty much Linux-only throughout the development process.

I'll test it now thanks @pijyoi

@ulikoehler if no one else wants to write it then I'll be happy to
whenever I'm free (I'm almost always free). Also I have a dual boot
setup with Windows 7 so I'll reboot into that once a week or so just to
make sure nothing is broken.

[hintjens]

@shancat regular builds on Windows would be awesome...

@pijyoi which packages will I need? At the moment I'm running make gcc
but is there anything else I'll need before compiling
libsodium/zmq/czmq?

@hintjens I'll get started ASAP then :)

[hintjens]

@shancat neat... :)

[pijyoi]

No other package is needed. You just need to build the cross compiler.

[ulikoehler]

I can see two different approaches here:

• Cross-Compiling
• Running the compiler in wine

The first one would obviously be easier but I'm not entirely sure if it doesn't act different if run (pseudo-)natively on Windows/Wine -- In the past I've had some problems cross-compiling ARMv6L packages for the Raspberry Pi. I didn't really try to track it down, but at least in this case, the native-approach did a better job.

Do you have experience with mingw crosscompiling?

I have no experience crosscompiling or with Wine but I'm happy to learn.
I think we should, at the very least, incorporate a MinGW build into
the autobuild. I'm sure I've seen other projects do this so it shouldn't
be too hard.

Baby-steps, we'll see how that goes and if something crops up regarding
MinGW we'll see what we can do regarding Wine. Sound like a plan?

[ulikoehler]

Absolutely :)

@pijyoi finally finished downloading gcc. Did you do anything special
for libsodium?

[pijyoi]

Libsodium builds cleanly with no changes. Just set prefix to local_mingw
like the rest. I believe the win32 binary distributed by libsodium is cross
compiled.

FWIW, czmq_selftest.exe runs without errors under wine. Lots of failures
for the zmq tests though. A lot of them are bind failures due to closing
and rebinding to the same port.

[hintjens]

No progress on this; closing it.