[mswin] (mingw32,mingw64): secp256k1 support

setup.py

@@ -22,6 +22,10 @@ from distutils.command.install_data import install_data
 import sys,os
 from shutil import copy2
 
+import subprocess as sp
+_gvi = sp.check_output(['gcc','--version']).splitlines()[0]
+have_mingw_64 = 'x86_64' in _gvi and 'MinGW' in _gvi
+
 # install extension module in repository after building
 class my_build_ext(build_ext):
 	def build_extension(self,ext):
@@ -44,16 +48,12 @@ module1 = Extension(
 	name         = 'mmgen.secp256k1',
 	sources      = ['extmod/secp256k1mod.c'],
 	libraries    = ['secp256k1'],
-	library_dirs = ['/usr/local/lib'],
-	runtime_library_dirs = ['/usr/local/lib'],
-	include_dirs = ['/usr/local/include'],
+	library_dirs = ['/usr/local/lib',r'c:\msys\local\lib'],
+	# mingw32 needs this, Linux can use it, but it breaks mingw64
+	extra_link_args = (['-lgmp'],[])[have_mingw_64],
+	include_dirs = ['/usr/local/include',r'c:\msys\local\include'],
 	)
 
-cmd_overrides = {
-	'linux': { 'build_ext': my_build_ext, 'install_data': my_install_data },
-	'win':   { 'install_data': my_install_data }
-}
-
 from mmgen.globalvars import g
 setup(
 		name         = 'mmgen',
@@ -65,9 +65,8 @@ setup(
 		license      = 'GNU GPL v3',
 		platforms    = 'Linux, MS Windows, Raspberry PI',
 		keywords     = 'Bitcoin, wallet, cold storage, offline storage, open-source, command-line, Python, Bitcoin Core, bitcoind, hd, deterministic, hierarchical, secure, anonymous',
-		cmdclass     = cmd_overrides[g.platform],
-		# disable building of secp256k1 extension module on Windows
-		ext_modules = ([],[module1])[g.platform=='linux'],
+		cmdclass     = { 'build_ext': my_build_ext, 'install_data': my_install_data },
+		ext_modules = [module1],
 		data_files = [('share/mmgen', [
 				'data_files/mmgen.cfg',     # source files must have 0644 mode
 				'data_files/mn_wordlist.c',