[Feature request] Mapnik 3.0 SDK built with MinGW-w64

[fawick]

Besides the MSVS 2015 builds that are coming it would be great if there were SDK versions built with/for MinGW-w64 (GCC 4.9.2) for both 32- and 64-bit.

This issue is important to me as I maintain a Go wrapper for mapnik (fawick/go-mapnik) that needs to bridge the gap between MinGW linking and the Mapnik 2.2 32-bit SDK built with MSVC on Windows. I currently work around that by compiling springmeyer/mapnik-c-api with MSVC to a pure C-symbols DLL and link the Go code directly with MinGW against that DLL (w/ cgo). Linking against mapnik.dll directly fails as MSVC and MinGW use different C++ name mangling schemes.

Having a MinGW SDK on Windows would open up the whole Mapnik C++ Interface to my wrapper.

[wilhelmberg]

@fawick currently, we don't have any plans to provide MinGW builds.

However, I'm not closing as a reminder to circle back and re-evaluate when we overhaul the build scripts (no time frame yet).

Overhauling might mean integration into mason or building a mason like system on Windows, and most likely will not happen before clang has reached full MSVC Compability.

[wilhelmberg]

Update:

Tried clang (LLVM-3.8.0-r244436-win32.exe) with VS2015 today.

Integration is easy (just /p:PlatformToolset=LLVM-vs2014), but full compatibility seems still far away.

Especially the plethora of switches (like /GS, /Yc, ...), that are not honored.

• zlib was no problem to build
• but with libpng I also had to change the source code, as clang seems to be very strict, e.g. a comparison, that it thinks will always be true, is an error and stops the build. And that's where I stopped, too.