Made setup.py more robust in how it enables 64bit visual studio compiles. It should now

be more future proof and in particular correctly enable 64bit compiles in visual studio 2017
when appropriate.

setup.py

@@ -36,6 +36,7 @@ import shutil
 import stat
 import errno
 
+import subprocess
 from setuptools.command.bdist_egg import bdist_egg as _bdist_egg
 from setuptools.command.develop import develop as _develop
 from distutils.command.build_ext import build_ext as _build_ext
@@ -43,6 +44,7 @@ from distutils.command.build import build as _build
 from distutils.errors import DistutilsSetupError
 from distutils.spawn import find_executable
 from distutils.sysconfig import get_python_inc, get_python_version, get_config_var
+from distutils.version import LooseVersion
 from distutils import log
 import os
 import sys
@@ -183,78 +185,6 @@ def enum_reg_key(rk):
     return sub_keys
 
 
-def get_msvc_win64_generator():
-    """find the default MSVC generator but Win64
-    This logic closely matches cmake's resolution for default build generator.
-    Only we select the Win64 version of it.
-    """
-    try:
-        import _winreg as winreg
-    except ImportError:
-        # noinspection PyUnresolvedReferences
-        import winreg
-
-    known_vs = {
-        "6.0": "Visual Studio 6",
-        "7.0": "Visual Studio 7",
-        "7.1": "Visual Studio 7 .NET 2003",
-        "8.0": "Visual Studio 8 2005",
-        "9.0": "Visual Studio 9 2008",
-        "10.0": "Visual Studio 10 2010",
-        "11.0": "Visual Studio 11 2012",
-        "12.0": "Visual Studio 12 2013",
-        "14.0": "Visual Studio 14 2015",
-    }
-
-    newest_vs = None
-    newest_ver = 0
-
-    platform_arch = platform.architecture()[0]
-    sam = winreg.KEY_WOW64_32KEY + winreg.KEY_READ if '64' in platform_arch else winreg.KEY_READ
-    for vs in ['VisualStudio\\', 'VCExpress\\', 'WDExpress\\']:
-        vs_key = "SOFTWARE\\Microsoft\\{vs}\\".format(vs=vs)
-        try:
-            root_key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, vs_key, 0, sam)
-        except OSError:
-            continue
-        try:
-            sub_keys = enum_reg_key(root_key)
-        except OSError:
-            sub_keys = []
-        winreg.CloseKey(root_key)
-        if not sub_keys:
-            continue
-
-        # look to see if we have InstallDir
-        for sub_key in sub_keys:
-            try:
-                root_key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, vs_key + sub_key, 0, sam)
-            except OSError:
-                continue
-            ins_dir = reg_value(root_key, 'InstallDir')
-            winreg.CloseKey(root_key)
-
-            if not ins_dir:
-                continue
-
-            gen_name = known_vs.get(sub_key)
-            if gen_name is None:
-                # if it looks like a version number
-                try:
-                    ver = float(sub_key)
-                except ValueError:
-                    continue
-                gen_name = 'Visual Studio %d' % int(ver)
-            else:
-                ver = float(sub_key)
-
-            if ver > newest_ver:
-                newest_vs = gen_name
-                newest_ver = ver
-
-    if newest_vs:
-        return ['-G', newest_vs + ' Win64']
-    return []
 
 try:
     from Queue import Queue, Empty
@@ -281,6 +211,10 @@ def _log_buf(buf):
     for line in lines:
         log.info(line)
 
+def get_cmake_version(cmake_path):
+    p = re.compile("version ([0-9.]+)")
+    cmake_output = subprocess.check_output(cmake_path + " --version").decode("utf-8");
+    return p.search(cmake_output).group(1)
 
 def run_process(cmds, timeout=None):
     """run a process asynchronously
@@ -538,8 +472,12 @@ class build(_build):
             cmake_extra_arch += ['-DPYTHON_LIBRARY={lib}'.format(lib=py_lib)]
 
         if sys.platform == "win32":
-            if platform_arch == '64bit' and  not generator_set:
-                cmake_extra_arch += get_msvc_win64_generator()
+            if platform_arch == '64bit':
+                cmake_extra_arch += ['-DCMAKE_GENERATOR_PLATFORM=x64']
+                # Setting the cmake generator only works in versions of cmake >= 3.1
+                if (LooseVersion(get_cmake_version(cmake_path)) < LooseVersion("3.1.0")):
+                    raise DistutilsSetupError(
+                        "You need to install a newer version of cmake. Version 3.1 or newer is required.");
 
             # this imitates cmake in path resolution
             py_ver = get_python_version()