Spack on Windows package ports

CMake - Windows Bootstrap (#25825)

Remove hardcoded cmake compiler (#26410)

Revert breaking cmake changes
Ensure no autotools on Windows

Perl on Windows (#26612)

Python source build windows (#26313)

Reconfigure sysconf for Windows

Python2.6 compatibility

Fxixup new sbang tests for windows

Ruby support (#28287)

Add NASM support (#28319)

Add mock Ninja package for testing

27 files changed, 648 insertions, 199 deletions

diff --git a/bin/spack_cmd.bat b/bin/spack_cmd.bat
index 5ba685fa46..56b6024665 100644
--- a/bin/spack_cmd.bat
+++ b/bin/spack_cmd.bat
@@ -15,8 +15,12 @@ popd
 
 :: Check if Python is on the PATH
 if not defined python_pf_ver (
-(for /f "delims=" %%F in ('where python.exe') do (set python_pf_ver=%%F) ) 2> NUL
+(for /f "delims=" %%F in ('where python.exe') do (
+                                                    set python_pf_ver=%%F
+                                                    goto :found_python
+                                                  ) ) 2> NUL
 )
+:found_python
 if not defined python_pf_ver (
     :: If not, look for Python from the Spack installer
     :get_builtin
@@ -35,7 +39,7 @@ if not defined python_pf_ver (
     :: Python is already on the path
     set py_exe=!python_pf_ver!
     (for /F "tokens=* USEBACKQ" %%F in (
-        `!py_exe! --version`) do (set "output=%%F")) 2>NUL
+        `"!py_exe!" --version`) do (set "output=%%F")) 2>NUL
     if not "!output:Microsoft Store=!"=="!output!" goto :get_builtin
     goto :exitpoint
 )
diff --git a/lib/spack/docs/getting_started.rst b/lib/spack/docs/getting_started.rst
index a904f0416a..8ba0a799a9 100644
--- a/lib/spack/docs/getting_started.rst
+++ b/lib/spack/docs/getting_started.rst
@@ -1588,14 +1588,6 @@ command line and also from 3rd-party software`` option. This will automatically
 update your ``PATH`` variable to include the ``git`` command.
 
 """"
-Perl
-""""
-
-Perl is a flexible and feature-rich programming language that comes built-in
-on Unix boxes but needs to be installed externally for Windows users. Fortunately,
-you can find the most recent release at https://www.perl.org/get.html.
-
-""""
 NASM
 """"
 
diff --git a/lib/spack/llnl/util/tty/__init__.py b/lib/spack/llnl/util/tty/__init__.py
index b244b8a58d..5b8729d7ec 100644
--- a/lib/spack/llnl/util/tty/__init__.py
+++ b/lib/spack/llnl/util/tty/__init__.py
@@ -146,7 +146,7 @@ def process_stacktrace(countback):
     file_list = []
     for frame in st:
         # Check that the file is a spack file
-        if frame[0].find("/spack") >= 0:
+        if frame[0].find(os.path.sep + "spack") >= 0:
             file_list.append(frame[0])
     # We use commonprefix to find what the spack 'root' directory is.
     root_dir = os.path.commonprefix(file_list)
diff --git a/lib/spack/spack/build_environment.py b/lib/spack/spack/build_environment.py
index 7888dee139..3281a24013 100644
--- a/lib/spack/spack/build_environment.py
+++ b/lib/spack/spack/build_environment.py
@@ -528,7 +528,9 @@ def _set_variables_for_single_module(pkg, module):
     m.cmake = Executable('cmake')
     m.ctest = MakeExecutable('ctest', jobs)
 
-    # Standard build system arguments
+    if os.name == 'nt':
+        m.nmake = Executable('nmake')
+    # Standard CMake arguments
     m.std_cmake_args = spack.build_systems.cmake.CMakePackage._std_args(pkg)
     m.std_meson_args = spack.build_systems.meson.MesonPackage._std_args(pkg)
     m.std_pip_args = spack.build_systems.python.PythonPackage._std_args(pkg)
diff --git a/lib/spack/spack/build_systems/autotools.py b/lib/spack/spack/build_systems/autotools.py
index 46a3ccddf7..a644c92622 100644
--- a/lib/spack/spack/build_systems/autotools.py
+++ b/lib/spack/spack/build_systems/autotools.py
@@ -14,7 +14,7 @@ import llnl.util.tty as tty
 from llnl.util.filesystem import force_remove, working_dir
 
 from spack.build_environment import InstallError
-from spack.directives import depends_on
+from spack.directives import conflicts, depends_on
 from spack.operating_systems.mac_os import macos_version
 from spack.package import PackageBase, run_after, run_before
 from spack.util.executable import Executable
@@ -104,6 +104,7 @@ class AutotoolsPackage(PackageBase):
     depends_on('gnuconfig', type='build', when='target=ppc64le:')
     depends_on('gnuconfig', type='build', when='target=aarch64:')
     depends_on('gnuconfig', type='build', when='target=riscv64:')
+    conflicts('platform=windows')
 
     @property
     def _removed_la_files_log(self):
diff --git a/lib/spack/spack/build_systems/cmake.py b/lib/spack/spack/build_systems/cmake.py
index 979a6bb024..591d73a5c4 100644
--- a/lib/spack/spack/build_systems/cmake.py
+++ b/lib/spack/spack/build_systems/cmake.py
@@ -93,15 +93,11 @@ class CMakePackage(PackageBase):
     #: See https://cmake.org/cmake/help/latest/manual/cmake-generators.7.html
     #: for more information.
 
-    variant('generator',
-            default='Make' if sys.platform != 'win32' else 'Ninja',
-            description='Build system to generate',
-            values=('Make', 'Ninja'))
+    generator = "Unix Makefiles"
 
-    depends_on('ninja', when='generator=Ninja')
-
-    generatorMap = {'Make': 'Unix Makefiles',
-                    'Ninja': 'Ninja'}
+    if sys.platform == 'win32':
+        generator = "Ninja"
+        depends_on('ninja')
 
     # https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html
     variant('build_type', default='RelWithDebInfo',
@@ -150,10 +146,10 @@ class CMakePackage(PackageBase):
         """Computes the standard cmake arguments for a generic package"""
 
         try:
-            pkg.generator = pkg.spec.variants['generator'].value
-        except KeyError:
-            pkg.generator = 'Make' if sys.platform != 'win32' else 'Ninja'
-        primary_generator = CMakePackage.generatorMap[pkg.generator]
+            if not pkg.generator:
+                raise AttributeError
+        except AttributeError:
+            pkg.generator = CMakePackage.generator
 
         try:
             build_type = pkg.spec.variants['build_type'].value
@@ -167,22 +163,16 @@ class CMakePackage(PackageBase):
 
         define = CMakePackage.define
         args = [
-            '-G', primary_generator,
+            '-G', pkg.generator,
             define('CMAKE_INSTALL_PREFIX', pkg.prefix.replace('\\', '/')),
             define('CMAKE_BUILD_TYPE', build_type),
-            define('CMAKE_C_COMPILER:FILEPATH', pkg.compiler.cc.replace('\\', '/')),
-            define('CMAKE_CXX_COMPILER:FILEPATH', pkg.compiler.cxx.replace('\\', '/'))
         ]
 
-        if pkg.compiler.fc is not None:
-            args.append(define('CMAKE_Fortran_COMPILER:FILEPATH',
-                               pkg.compiler.fc.replace('\\', '/')))
-
         # CMAKE_INTERPROCEDURAL_OPTIMIZATION only exists for CMake >= 3.9
         if pkg.spec.satisfies('^cmake@3.9:'):
             args.append(define('CMAKE_INTERPROCEDURAL_OPTIMIZATION', ipo))
 
-        if primary_generator == 'Unix Makefiles':
+        if pkg.generator == 'Unix Makefiles':
             args.append(define('CMAKE_VERBOSE_MAKEFILE', True))
 
         if platform.mac_ver()[0]:
diff --git a/lib/spack/spack/cmd/unit_test.py b/lib/spack/spack/cmd/unit_test.py
index 0faa05b834..05c308b84c 100644
--- a/lib/spack/spack/cmd/unit_test.py
+++ b/lib/spack/spack/cmd/unit_test.py
@@ -130,7 +130,7 @@ def do_list(args, extra_args):
         # in the future - so this manipulation might be fragile
         if nodetype.lower() == 'function':
             name_parts.append(item)
-            key_end = os.path.join(*[x[1] for x in key_parts])
+            key_end = os.path.join(*key_parts[-1][1].split('/'))
             key = next(f for f in files if f.endswith(key_end))
             tests[key].add(tuple(x[1] for x in name_parts))
         elif nodetype.lower() == 'class':
diff --git a/lib/spack/spack/compilers/msvc.py b/lib/spack/spack/compilers/msvc.py
index d0ae6921ea..f51583caf4 100644
--- a/lib/spack/spack/compilers/msvc.py
+++ b/lib/spack/spack/compilers/msvc.py
@@ -4,13 +4,37 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 import os
+import re
 import subprocess
 import sys
-from typing import List  # novm
+from distutils.version import StrictVersion
+from typing import Dict, List, Set  # novm
 
 import spack.operating_systems.windows_os
 import spack.util.executable
 from spack.compiler import Compiler
+from spack.error import SpackError
+
+avail_fc_version = set()  # type: Set[str]
+fc_path = dict()  # type: Dict[str, str]
+
+fortran_mapping = {
+    '2021.3.0': '19.29.30133',
+    '2021.2.1': '19.28.29913',
+    '2021.2.0': '19.28.29334',
+    '2021.1.0': '19.28.29333',
+}
+
+
+def get_valid_fortran_pth(comp_ver):
+    cl_ver = str(comp_ver).split('@')[1]
+    sort_fn = lambda fc_ver: StrictVersion(fc_ver)
+    sort_fc_ver = sorted(list(avail_fc_version), key=sort_fn)
+    for ver in sort_fc_ver:
+        if ver in fortran_mapping:
+            if StrictVersion(cl_ver) <= StrictVersion(fortran_mapping[ver]):
+                return fc_path[ver]
+    return None
 
 
 class Msvc(Compiler):
@@ -46,6 +70,8 @@ class Msvc(Compiler):
     # file based on compiler executable path.
 
     def __init__(self, *args, **kwargs):
+        new_pth = [pth if pth else get_valid_fortran_pth(args[0]) for pth in args[3]]
+        args[3][:] = new_pth
         super(Msvc, self).__init__(*args, **kwargs)
         if os.getenv("ONEAPI_ROOT"):
             # If this found, it sets all the vars
@@ -65,6 +91,12 @@ class Msvc(Compiler):
     def pic_flag(self):
         return ""
 
+    @property
+    def msvc_version(self):
+        ver = re.search(Msvc.version_regex, self.cc).group(1)
+        ver = "".join(ver.split('.')[:2])[:-1]
+        return "MSVC" + ver
+
     def setup_custom_environment(self, pkg, env):
         """Set environment variables for MSVC using the
         Microsoft-provided script."""
@@ -81,44 +113,40 @@ class Msvc(Compiler):
             if sys.version_info[0] >= 3:
                 out = out.decode('utf-16le', errors='replace')  # novermin
 
-            int_env = {  # novermin
-                key.lower(): value
-                for key, _, value in
-                (line.partition('=') for line in out.splitlines())
-                if key and value
-            }
+            int_env = dict((key.lower(), value) for key, _, value in
+                           (line.partition('=') for line in out.splitlines())
+                           if key and value)
 
             if 'path' in int_env:
                 env.set_path('PATH', int_env['path'].split(';'))
             env.set_path('INCLUDE', int_env.get('include', '').split(';'))
             env.set_path('LIB', int_env.get('lib', '').split(';'))
+
+            env.set('CC', self.cc)
+            env.set('CXX', self.cxx)
+            env.set('FC', self.fc)
+            env.set('F77', self.f77)
         else:
             # Should not this be an exception?
             print("Cannot pull msvc compiler information in Python 2.6 or below")
 
-    # fc_version only loads the ifx compiler into the first MSVC stanza;
-    # if there are other versions of Microsoft VS installed and detected, they
-    # will only have cl.exe as the C/C++ compiler
-
     @classmethod
     def fc_version(cls, fc):
         # We're using intel for the Fortran compilers, which exist if
         # ONEAPI_ROOT is a meaningful variable
+        fc_ver = cls.default_version(fc)
+        avail_fc_version.add(fc_ver)
+        fc_path[fc_ver] = fc
         if os.getenv("ONEAPI_ROOT"):
             try:
                 sps = spack.operating_systems.windows_os.WindowsOs.compiler_search_paths
-            except Exception:
-                print("sps not found.")
-                raise
-            try:
-                clp = spack.util.executable.which_string("cl", path=sps)
-            except Exception:
-                print("cl not found.")
-                raise
+            except AttributeError:
+                raise SpackError("Windows compiler search paths not established")
+            clp = spack.util.executable.which_string("cl", path=sps)
             ver = cls.default_version(clp)
-            return ver
         else:
-            return cls.default_version(fc)
+            ver = fc_ver
+        return ver
 
     @classmethod
     def f77_version(cls, f77):
diff --git a/lib/spack/spack/detection/path.py b/lib/spack/spack/detection/path.py
index f280af4520..ee98e23841 100644
--- a/lib/spack/spack/detection/path.py
+++ b/lib/spack/spack/detection/path.py
@@ -12,7 +12,6 @@ import re
 import sys
 import warnings
 
-
 import llnl.util.filesystem
 import llnl.util.tty
 
diff --git a/lib/spack/spack/fetch_strategy.py b/lib/spack/spack/fetch_strategy.py
index f9823fb648..2435da4b2f 100644
--- a/lib/spack/spack/fetch_strategy.py
+++ b/lib/spack/spack/fetch_strategy.py
@@ -353,8 +353,9 @@ class URLFetchStrategy(FetchStrategy):
             # Telling urllib to check if url is accessible
             try:
                 url, headers, response = spack.util.web.read_from_url(url)
-            except spack.util.web.SpackWebError:
-                msg = "Urllib fetch failed to verify url {0}".format(url)
+            except spack.util.web.SpackWebError as werr:
+                msg = "Urllib fetch failed to verify url\
+                      {0}\n with error {1}".format(url, werr)
                 raise FailedDownloadError(url, msg)
             return (response.getcode() is None or response.getcode() == 200)
 
diff --git a/lib/spack/spack/platforms/_platform.py b/lib/spack/spack/platforms/_platform.py
index b68b7f1299..a19381b8d4 100644
--- a/lib/spack/spack/platforms/_platform.py
+++ b/lib/spack/spack/platforms/_platform.py
@@ -2,6 +2,8 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import platform
+
 import llnl.util.lang
 
 import spack.error
@@ -143,3 +145,6 @@ class Platform(object):
             for o in sorted(self.operating_sys.values()):
                 yield o._cmp_iter
         yield oses
+
+    def is_64bit(self):
+        return platform.machine().endswith('64')
diff --git a/lib/spack/spack/test/bootstrap.py b/lib/spack/spack/test/bootstrap.py
index 8b72a98ad3..d753e2cdfa 100644
--- a/lib/spack/spack/test/bootstrap.py
+++ b/lib/spack/spack/test/bootstrap.py
@@ -131,7 +131,7 @@ spack:
         # Don't trigger evaluation here
         with spack.bootstrap.ensure_bootstrap_configuration():
             pass
-        assert str(spack.store.root) == '/tmp/store'
+        assert str(spack.store.root) == sep + os.path.join('tmp', 'store')
 
 
 def test_nested_use_of_context_manager(mutable_config):
diff --git a/lib/spack/spack/test/cmd/unit_test.py b/lib/spack/spack/test/cmd/unit_test.py
index 276996501b..aa31282fdb 100644
--- a/lib/spack/spack/test/cmd/unit_test.py
+++ b/lib/spack/spack/test/cmd/unit_test.py
@@ -3,10 +3,12 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import os
+
 from spack.main import SpackCommand
 
 spack_test = SpackCommand('unit-test')
-cmd_test_py = 'lib/spack/spack/test/cmd/unit_test.py'
+cmd_test_py = os.path.join('lib', 'spack', 'spack', 'test', 'cmd', 'unit_test.py')
 
 
 def test_list():
diff --git a/lib/spack/spack/test/cmd/url.py b/lib/spack/spack/test/cmd/url.py
index 204f3a81b1..1e4c0d391a 100644
--- a/lib/spack/spack/test/cmd/url.py
+++ b/lib/spack/spack/test/cmd/url.py
@@ -3,6 +3,7 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 import re
+import sys
 
 import pytest
 
diff --git a/lib/spack/spack/test/relocate.py b/lib/spack/spack/test/relocate.py
index a64052c7c8..4ef9ae4bb3 100644
--- a/lib/spack/spack/test/relocate.py
+++ b/lib/spack/spack/test/relocate.py
@@ -2,6 +2,7 @@
 # Spack Project Developers. See the top-level COPYRIGHT file for details.
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
+import os
 import os.path
 import re
 import shutil
diff --git a/lib/spack/spack/test/sbang.py b/lib/spack/spack/test/sbang.py
index aa9d9b10dd..f0cc1835d9 100644
--- a/lib/spack/spack/test/sbang.py
+++ b/lib/spack/spack/test/sbang.py
@@ -11,6 +11,7 @@ import grp
 import os
 import shutil
 import stat
+import sys
 import tempfile
 
 import pytest
@@ -193,6 +194,8 @@ def test_shebang_interpreter_regex(shebang, interpreter):
     sbang.get_interpreter(shebang) == interpreter
 
 
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="Not supported on Windows (yet)")
 def test_shebang_handling(script_dir, sbang_line):
     sbang.filter_shebangs_in_directory(script_dir.tempdir)
 
@@ -339,6 +342,8 @@ def test_install_user_sbang(install_mockery, configure_user_perms):
     run_test_install_sbang(False)
 
 
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="Not supported on Windows (yet)")
 def test_install_sbang_too_long(tmpdir):
     root = str(tmpdir)
     num_extend = sbang.system_shebang_limit - len(root) - len('/bin/sbang')
@@ -357,6 +362,8 @@ def test_install_sbang_too_long(tmpdir):
     assert 'cannot patch' in err
 
 
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="Not supported on Windows (yet)")
 def test_sbang_hook_skips_nonexecutable_blobs(tmpdir):
     # Write a binary blob to non-executable.sh, with a long interpreter "path"
     # consisting of invalid UTF-8. The latter is technically not really necessary for
@@ -374,6 +381,8 @@ def test_sbang_hook_skips_nonexecutable_blobs(tmpdir):
         assert b'sbang' not in f.readline()
 
 
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="Not supported on Windows (yet)")
 def test_sbang_handles_non_utf8_files(tmpdir):
     # We have an executable with a copyright sign as filename
     contents = (b'#!' + b'\xa9' * sbang.system_shebang_limit +
@@ -408,6 +417,8 @@ def shebang_limits_system_8_spack_16():
     sbang.spack_shebang_limit = spack_limit
 
 
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="Not supported on Windows (yet)")
 def test_shebang_exceeds_spack_shebang_limit(shebang_limits_system_8_spack_16, tmpdir):
     """Tests whether shebangs longer than Spack's limit are skipped"""
     file = str(tmpdir.join('longer_than_spack_limit.sh'))
@@ -421,6 +432,8 @@ def test_shebang_exceeds_spack_shebang_limit(shebang_limits_system_8_spack_16, t
         assert b'sbang' not in f.read()
 
 
+@pytest.mark.skipif(sys.platform == 'win32',
+                    reason="Not supported on Windows (yet)")
 def test_sbang_hook_handles_non_writable_files_preserving_permissions(tmpdir):
     path = str(tmpdir.join('file.sh'))
     with open(path, 'w') as f:
diff --git a/var/spack/repos/builtin.mock/packages/ninja/package.py b/var/spack/repos/builtin.mock/packages/ninja/package.py
new file mode 100644
index 0000000000..3ed308b3c0
--- /dev/null
+++ b/var/spack/repos/builtin.mock/packages/ninja/package.py
@@ -0,0 +1,15 @@
+# Copyright 2013-2021 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack import *
+
+
+class Ninja(Package):
+    """Dummy Ninja Package"""
+
+    homepage = "https://ninja-build.org/"
+    url      = "https://github.com/ninja-build/ninja/archive/v1.7.2.tar.gz"
+
+    version('1.10.2', sha256='ce35865411f0490368a8fc383f29071de6690cbadc27704734978221f25e2bed')
diff --git a/var/spack/repos/builtin/packages/cmake/package.py b/var/spack/repos/builtin/packages/cmake/package.py
index e91b6eacdc..e431dc62e5 100644
--- a/var/spack/repos/builtin/packages/cmake/package.py
+++ b/var/spack/repos/builtin/packages/cmake/package.py
@@ -3,9 +3,13 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
+import os
 import re
+import shutil
+import sys
 
 import spack.build_environment
+from spack import *
 
 
 class Cmake(Package):
@@ -141,6 +145,12 @@ class Cmake(Package):
     # https://gitlab.kitware.com/cmake/cmake/merge_requests/4075
     patch('fix-xlf-ninja-mr-4075.patch', sha256="42d8b2163a2f37a745800ec13a96c08a3a20d5e67af51031e51f63313d0dedd1", when="@3.15.5")
 
+    generator = "Unix Makefiles"
+
+    if sys.platform == 'win32':
+        generator = "Ninja"
+        depends_on('ninja')
+
     # We default ownlibs to true because it greatly speeds up the CMake
     # build, and CMake is built frequently. Also, CMake is almost always
     # a build dependency, and its libs will not interfere with others in
@@ -149,7 +159,7 @@ class Cmake(Package):
     variant('qt',      default=False, description='Enables the build of cmake-gui')
     variant('doc',     default=False, description='Enables the generation of html and man page documentation')
     variant('openssl', default=True,  description="Enable openssl for curl bootstrapped by CMake when using +ownlibs")
-    variant('ncurses', default=True,  description='Enables the build of the ncurses gui')
+    variant('ncurses', default=os.name != 'nt',  description='Enables the build of the ncurses gui')
 
     # See https://gitlab.kitware.com/cmake/cmake/-/issues/21135
     conflicts('%gcc platform=darwin', when='@:3.17',
@@ -241,36 +251,47 @@ class Cmake(Package):
                 flags.append(self.compiler.cxx11_flag)
         return (flags, None, None)
 
-    def bootstrap_args(self):
+    def setup_build_environment(self, env):
         spec = self.spec
-        args = [
-            '--prefix={0}'.format(self.prefix),
-            '--parallel={0}'.format(make_jobs)
-        ]
+        if '+openssl' in spec:
+            env.set('OPENSSL_ROOT_DIR', spec['openssl'].prefix)
 
-        if '+ownlibs' in spec:
-            # Build and link to the CMake-provided third-party libraries
-            args.append('--no-system-libs')
-        else:
-            # Build and link to the Spack-installed third-party libraries
-            args.append('--system-libs')
-
-            if spec.satisfies('@3.2:'):
-                # jsoncpp requires CMake to build
-                # use CMake-provided library to avoid circular dependency
-                args.append('--no-system-jsoncpp')
-
-        if '+qt' in spec:
-            args.append('--qt-gui')
+    def bootstrap_args(self):
+        spec = self.spec
+        args = []
+        if not os.name == 'nt':
+            args.extend(
+                ['--prefix={0}'.format(self.prefix),
+                 '--parallel={0}'.format(make_jobs)]
+            )
+
+            if '+ownlibs' in spec:
+                # Build and link to the CMake-provided third-party libraries
+                args.append('--no-system-libs')
+            else:
+                # Build and link to the Spack-installed third-party libraries
+                args.append('--system-libs')
+
+                if spec.satisfies('@3.2:'):
+                    # jsoncpp requires CMake to build
+                    # use CMake-provided library to avoid circular dependency
+                    args.append('--no-system-jsoncpp')
+
+            if '+qt' in spec:
+                args.append('--qt-gui')
+            else:
+                args.append('--no-qt-gui')
+
+            if '+doc' in spec:
+                args.append('--sphinx-html')
+                args.append('--sphinx-man')
+
+            # Now for CMake arguments to pass after the initial bootstrap
+            args.append('--')
         else:
-            args.append('--no-qt-gui')
-
-        if '+doc' in spec:
-            args.append('--sphinx-html')
-            args.append('--sphinx-man')
-
-        # Now for CMake arguments to pass after the initial bootstrap
-        args.append('--')
+            args.append('-DCMAKE_INSTALL_PREFIX=%s' % self.prefix)
+        if self.spec.satisfies('generator=Ninja'):
+            args.append('-GNinja')
 
         args.append('-DCMAKE_BUILD_TYPE={0}'.format(
             self.spec.variants['build_type'].value))
@@ -297,21 +318,61 @@ class Cmake(Package):
 
         return args
 
+    def winbootcmake(self, spec):
+        from spack import fetch_strategy, stage
+        urls = {
+            '3': ('https://cmake.org/files/v3.21/cmake-3.21.2-windows-x86_64.zip', "f21e72ede9d15070602b60b2c14dc779"),
+            '2': ('https://cmake.org/files/v2.8/cmake-2.8.4-win32-x86.zip', "a2525342e495518101381203bf4484c4")
+        }
+        if spec.satisfies('@3.0.2:'):
+            bootstrap_url = urls['3']
+        else:
+            bootstrap_url = urls['2']
+        remote = fetch_strategy.URLFetchStrategy(url=bootstrap_url[0],
+                                                 checksum=bootstrap_url[1])
+        bootstrap_stage_path = os.path.join(self.stage.path, "cmake-bootstraper")
+        with stage.Stage(remote, path=bootstrap_stage_path) as bootstrap_stage:
+            remote.stage = bootstrap_stage
+            remote.fetch()
+            remote.check()
+            remote.expand()
+            shutil.move(bootstrap_stage.source_path, self.stage.source_path)
+
+    def cmake_bootstrap(self):
+        exe_prefix = self.stage.source_path
+        relative_cmake_exe = os.path.join('spack-src', 'bin', 'cmake.exe')
+        return Executable(os.path.join(exe_prefix, relative_cmake_exe))
+
     def bootstrap(self, spec, prefix):
-        bootstrap = Executable('./bootstrap')
-        bootstrap(*self.bootstrap_args())
+        bootstrap_args = self.bootstrap_args()
+        if os.name == 'nt':
+            self.winbootcmake(spec)
+            bootstrap = self.cmake_bootstrap()
+            bootstrap_args.extend(['.'])
+        else:
+            bootstrap = Executable('./bootstrap')
+        bootstrap(*bootstrap_args)
 
     def build(self, spec, prefix):
-        make()
+        if self.generator == "Ninja":
+            ninja()
+        else:
+            make()
 
     @run_after('build')
     @on_package_attributes(run_tests=True)
     def build_test(self):
         # Some tests fail, takes forever
-        make('test')
+        if self.generator == "Ninja":
+            ninja('test')
+        else:
+            make('test')
 
     def install(self, spec, prefix):
-        make('install')
+        if self.generator == "Ninja":
+            ninja('install')
+        else:
+            make('install')
 
         if spec.satisfies('%fj'):
             for f in find(self.prefix, 'FindMPI.cmake', recursive=True):
diff --git a/var/spack/repos/builtin/packages/nasm/msvc.mak.patch b/var/spack/repos/builtin/packages/nasm/msvc.mak.patch
new file mode 100644
index 0000000000..cfc751c8cf
--- /dev/null
+++ b/var/spack/repos/builtin/packages/nasm/msvc.mak.patch
@@ -0,0 +1,18 @@
+diff --git a/Mkfiles/msvc.mak b/Mkfiles/msvc1.mak
+index 4f6121f..f0e6f4b 100644
+--- a/Mkfiles/msvc.mak
++++ b/Mkfiles/msvc1.mak
+@@ -228,10 +228,10 @@ WARNFILES = asm\warnings.c include\warnings.h doc\warnings.src
+ 
+ warnings:
+ 	$(RM_F) $(WARNFILES)
+-	$(MAKE) asm\warnings.time
++# 	$(MAKE) asm\warnings.time
+ 
+-asm\warnings.time: $(ALLOBJ:.@OBJEXT@=.c)
+-	: > asm\warnings.time
++# asm\warnings.time: $(ALLOBJ:.@OBJEXT@=.c)
++# 	: > asm\warnings.time
+ 	$(MAKE) $(WARNFILES)
+ 
+ asm\warnings.c: asm\warnings.pl asm\warnings.time
diff --git a/var/spack/repos/builtin/packages/nasm/package.py b/var/spack/repos/builtin/packages/nasm/package.py
index 2f0c747a52..6bfa36a660 100644
--- a/var/spack/repos/builtin/packages/nasm/package.py
+++ b/var/spack/repos/builtin/packages/nasm/package.py
@@ -5,17 +5,20 @@
 
 from spack import *
 
+is_windows = str(spack.platforms.host()) == 'windows'
 
-class Nasm(AutotoolsPackage):
+
+class Nasm(Package):
     """NASM (Netwide Assembler) is an 80x86 assembler designed for
     portability and modularity. It includes a disassembler as well."""
 
     homepage = "https://www.nasm.us"
-    url      = "https://www.nasm.us/pub/nasm/releasebuilds/2.14.02/nasm-2.14.02.tar.xz"
+    url      = "https://www.nasm.us/pub/nasm/releasebuilds/2.14.02/nasm-2.14.02.tar.gz"
     list_url = "https://www.nasm.us/pub/nasm/releasebuilds"
     list_depth = 1
+    a = '3caf6729c1073bf96629b57cee31eeb54f4f8129b01902c73428836550b30a3f'
 
-    version('2.15.05', sha256='3caf6729c1073bf96629b57cee31eeb54f4f8129b01902c73428836550b30a3f')
+    version('2.15.05', sha256='9182a118244b058651c576baa9d0366ee05983c4d4ae1d9ddd3236a9f2304997')
     version('2.14.02', sha256='e24ade3e928f7253aa8c14aa44726d1edf3f98643f87c9d72ec1df44b26be8f5')
     version('2.13.03', sha256='812ecfb0dcbc5bd409aaa8f61c7de94c5b8752a7b00c632883d15b2ed6452573')
     version('2.11.06', sha256='90f60d95a15b8a54bf34d87b9be53da89ee3d6213ea739fb2305846f4585868a')
@@ -24,9 +27,13 @@ class Nasm(AutotoolsPackage):
     # https://bugzilla.nasm.us/show_bug.cgi?id=3392461
     patch('https://src.fedoraproject.org/rpms/nasm/raw/0cc3eb244bd971df81a7f02bc12c5ec259e1a5d6/f/0001-Remove-invalid-pure_func-qualifiers.patch', level=1, sha256='ac9f315d204afa6b99ceefa1fe46d4eed2b8a23c7315d32d33c0f378d930e950', when='@2.13.03 %gcc@8:')
 
+    patch('msvc.mak.patch', when='platform=windows')
+
     conflicts('%intel@:14', when='@2.14:',
               msg="Intel 14 has immature C11 support")
 
+    phases = ['configure', 'build', 'install']
+
     def patch(self):
         # Remove flags not recognized by the NVIDIA compiler
         if self.spec.satisfies('%nvhpc@:20.11'):
@@ -34,3 +41,23 @@ class Nasm(AutotoolsPackage):
                         'CFLAGS="$pa_add_cflags__old_cflags"', 'configure')
             filter_file(r'CFLAGS="\$pa_add_flags__old_flags -Werror=.*"',
                         'CFLAGS="$pa_add_flags__old_flags"', 'configure')
+
+    def configure(self, spec, prefix):
+        with working_dir(self.stage.source_path, create=True):
+            if not is_windows:
+                configure(['--prefix={0}'.format(self.prefix)])
+
+    def build(self, spec, prefix):
+        with working_dir(self.stage.source_path):
+            if is_windows:
+                touch('asm\\warnings.time')
+                nmake('/f', 'Mkfiles\\msvc.mak')
+            else:
+                make(['V=1'])
+
+    def install(self, spec, prefix):
+        with working_dir(self.stage.source_path):
+            if is_windows:
+                pass
+            else:
+                make(['install'])
diff --git a/var/spack/repos/builtin/packages/netlib-lapack/package.py b/var/spack/repos/builtin/packages/netlib-lapack/package.py
index 5d527fedec..82af36426d 100644
--- a/var/spack/repos/builtin/packages/netlib-lapack/package.py
+++ b/var/spack/repos/builtin/packages/netlib-lapack/package.py
@@ -71,7 +71,6 @@ class NetlibLapack(CMakePackage):
     depends_on('blas', when='+external-blas')
     depends_on('netlib-xblas+fortran+plain_blas', when='+xblas')
     depends_on('python@2.7:', type='test')
-    depends_on('ninja@1.10.0:', when='platform=windows')
 
     # We need to run every phase twice in order to get static and shared
     # versions of the libraries. When ~shared, we run the default
diff --git a/var/spack/repos/builtin/packages/openssl/package.py b/var/spack/repos/builtin/packages/openssl/package.py
index f21b6b81a8..f57a65271a 100644
--- a/var/spack/repos/builtin/packages/openssl/package.py
+++ b/var/spack/repos/builtin/packages/openssl/package.py
@@ -5,6 +5,7 @@
 
 import os
 import re
+import sys
 
 import llnl.util.tty as tty
 
@@ -96,6 +97,8 @@ class Openssl(Package):   # Uses Fake Autotools, should subclass Package
     depends_on('perl@5.14.0:', type=('build', 'test'))
     depends_on('ca-certificates-mozilla', type=('build', 'run'), when='certs=mozilla')
 
+    conflicts('+dynamic', when=sys.platform != 'win32')
+
     @classmethod
     def determine_version(cls, exe):
         output = Executable(exe)('version', output=str, error=str)
@@ -151,7 +154,7 @@ class Openssl(Package):   # Uses Fake Autotools, should subclass Package
                    'CC=\"%s\"' % os.environ.get('SPACK_CC'),
                    'CXX=\"%s\"' % os.environ.get('SPACK_CXX'),
                    '%s' % shared_flag,
-                   'VC-WIN64A')
+                   'VC-WIN64A', ignore_quotes=True)
         else:
             config = Executable('./config')
             config('--prefix=%s' % prefix,
diff --git a/var/spack/repos/builtin/packages/perl/package.py b/var/spack/repos/builtin/packages/perl/package.py
index 0d666b41d3..714c7e3a7b 100644
--- a/var/spack/repos/builtin/packages/perl/package.py
+++ b/var/spack/repos/builtin/packages/perl/package.py
@@ -11,15 +11,20 @@
 # Author: Justin Too <justin@doubleotoo.com>
 # Date: September 6, 2015
 #
+
 import os
 import re
 from contextlib import contextmanager
 
 from llnl.util.lang import match_predicate
+from llnl.util.symlink import symlink
 
 from spack import *
 from spack.operating_systems.mac_os import macos_version
 
+host = spack.platforms.host()
+is_windows = str(host) == 'windows'
+
 
 class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
     """Perl 5 is a highly capable, feature-rich programming language with over
@@ -64,15 +69,16 @@ class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
 
     extendable = True
 
-    # Bind us below gdbm-1.20 due to API change: https://github.com/Perl/perl5/issues/18915
-    depends_on('gdbm@:1.19')
-    # :5.28 needs gdbm@:1:14.1: https://rt-archive.perl.org/perl5/Ticket/Display.html?id=133295
-    depends_on('gdbm@:1.14.1', when='@:5.28.0')
-    depends_on('berkeley-db')
-    depends_on('bzip2')
-    depends_on('zlib')
-    # :5.24.1 needs zlib@:1.2.8: https://rt.cpan.org/Public/Bug/Display.html?id=120134
-    depends_on('zlib@:1.2.8', when='@5.20.3:5.24.1')
+    if not is_windows:
+        # Bind us below gdbm-1.20 due to API change: https://github.com/Perl/perl5/issues/18915
+        depends_on('gdbm@:1.19')
+        # :5.28 needs gdbm@:1:14.1: https://rt-archive.perl.org/perl5/Ticket/Display.html?id=133295
+        depends_on('gdbm@:1.14.1', when='@:5.28.0')
+        depends_on('berkeley-db')
+        depends_on('bzip2')
+        depends_on('zlib')
+        # :5.24.1 needs zlib@:1.2.8: https://rt.cpan.org/Public/Bug/Display.html?id=120134
+        depends_on('zlib@:1.2.8', when='@5.20.3:5.24.1')
 
     # there has been a long fixed issue with 5.22.0 with regard to the ccflags
     # definition.  It is well documented here:
@@ -181,6 +187,23 @@ class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
         perm = os.stat(filename).st_mode
         os.chmod(filename, perm | 0o200)
 
+    @property
+    def nmake_arguments(self):
+        args = []
+        if self.spec.satisfies('%msvc'):
+            args.append('CCTYPE=%s' % self.compiler.msvc_version)
+        else:
+            raise RuntimeError("Perl unsupported for non MSVC compilers on Windows")
+        args.append('INST_TOP="%s"' % self.prefix.replace('/', '\\'))
+        args.append("INST_ARCH=\\$(ARCHNAME)")
+        if self.spec.satisfies('~shared'):
+            args.append("ALL_STATIC=%s" % "define")
+        if self.spec.satisfies('~threads'):
+            args.extend(["USE_MULTI=undef", "USE_ITHREADS=undef", "USE_IMP_SYS=undef"])
+        if not host.is_64bit():
+            args.append("WIN64=undef")
+        return args
+
     def configure_args(self):
         spec = self.spec
         prefix = self.prefix
@@ -229,30 +252,69 @@ class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
         return config_args
 
     def configure(self, spec, prefix):
+        if is_windows:
+            return
         configure = Executable('./Configure')
         configure(*self.configure_args())
 
     def build(self, spec, prefix):
-        make()
+        if is_windows:
+            pass
+        else:
+            make()
 
     @run_after('build')
     @on_package_attributes(run_tests=True)
     def build_test(self):
-        make('test')
+        if is_windows:
+            win32_dir = os.path.join(self.stage.source_path, "win32")
+            with working_dir(win32_dir):
+                nmake('test', ignore_quotes=True)
+        else:
+            make('test')
 
     def install(self, spec, prefix):
-        make('install')
+        if is_windows:
+            win32_dir = os.path.join(self.stage.source_path, "win32")
+            with working_dir(win32_dir):
+                nmake('install', *self.nmake_arguments,  ignore_quotes=True)
+        else:
+            make('install')
+
+    @run_after('install')
+    def symlink_windows(self):
+        if not is_windows:
+            return
+        win_install_path = os.path.join(self.prefix.bin, "MSWin32")
+        if host.is_64bit():
+            win_install_path += "-x64"
+        else:
+            win_install_path += "-x86"
+        if self.spec.satisfies("+threads"):
+            win_install_path += "-multi-thread"
+        else:
+            win_install_path += "-perlio"
+
+        for f in os.listdir(os.path.join(self.prefix.bin, win_install_path)):
+            lnk_path = os.path.join(self.prefix.bin, f)
+            src_path = os.path.join(win_install_path, f)
+            if not os.path.exists(lnk_path):
+                symlink(src_path, lnk_path)
 
     @run_after('install')
     def install_cpanm(self):
         spec = self.spec
-
+        maker = make
+        win_prefix = ''
+        if is_windows:
+            maker = nmake
+            win_prefix = self.stage.source_path
         if '+cpanm' in spec:
-            with working_dir(join_path('cpanm', 'cpanm')):
+            with working_dir(join_path(win_prefix, 'cpanm', 'cpanm')):
                 perl = spec['perl'].command
                 perl('Makefile.PL')
-                make()
-                make('install')
+                maker()
+                maker('install')
 
     def _setup_dependent_env(self, env, dependent_spec, deptypes):
         """Set PATH and PERL5LIB to include the extension and
@@ -295,6 +357,9 @@ class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
             mkdirp(module.perl_lib_dir)
 
     def setup_build_environment(self, env):
+        if is_windows:
+            return
+
         spec = self.spec
 
         if (spec.version <= Version('5.34.0')
@@ -321,7 +386,8 @@ class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
         frustrates filter_file on some filesystems (NFSv4), so make them
         temporarily writable.
         """
-
+        if is_windows:
+            return
         kwargs = {'ignore_absent': True, 'backup': False, 'string': False}
 
         # Find the actual path to the installed Config.pm file.
@@ -409,8 +475,11 @@ class Perl(Package):  # Perl doesn't use Autotools, it should subclass Package
             Executable: the Perl command
         """
         for ver in ('', self.spec.version):
-            path = os.path.join(self.prefix.bin, '{0}{1}'.format(
-                self.spec.name, ver))
+            ext = ''
+            if is_windows:
+                ext = '.exe'
+            path = os.path.join(self.prefix.bin, '{0}{1}{2}'.format(
+                self.spec.name, ver, ext))
             if os.path.exists(path):
                 return Executable(path)
         else:
diff --git a/var/spack/repos/builtin/packages/python/cpython-windows-externals.patch b/var/spack/repos/builtin/packages/python/cpython-windows-externals.patch
new file mode 100644
index 0000000000..c3bcce983f
--- /dev/null
+++ b/var/spack/repos/builtin/packages/python/cpython-windows-externals.patch
@@ -0,0 +1,28 @@
+diff --git a/PCbuild/get_externals.bat b/PCbuild/get_externals.bat
+index b5a44e3..52941c7 100644
+--- a/PCbuild/get_externals.bat
++++ b/PCbuild/get_externals.bat
+@@ -76,7 +76,7 @@ for %%e in (%libraries%) do (
+ echo.Fetching external binaries...
+ 
+ set binaries=
+-if NOT "%IncludeLibffi%"=="false"  set binaries=%binaries% libffi
++if NOT "%IncludeLibffi%"=="false"  set binaries=%binaries% libffi-3.3.0
+ if NOT "%IncludeSSL%"=="false"     set binaries=%binaries% openssl-bin-1.1.1k-1
+ if NOT "%IncludeTkinter%"=="false" set binaries=%binaries% tcltk-8.6.9.0
+ if NOT "%IncludeSSLSrc%"=="false"  set binaries=%binaries% nasm-2.11.06
+diff --git a/PCbuild/python.props b/PCbuild/python.props
+index 419d5eb..c66fb07 100644
+--- a/PCbuild/python.props
++++ b/PCbuild/python.props
+@@ -59,8 +59,8 @@
+     <sqlite3Dir>$(ExternalsDir)sqlite-3.35.5.0\</sqlite3Dir>
+     <bz2Dir>$(ExternalsDir)bzip2-1.0.6\</bz2Dir>
+     <lzmaDir>$(ExternalsDir)xz-5.2.2\</lzmaDir>
+-    <libffiDir>$(ExternalsDir)libffi\</libffiDir>
+-    <libffiOutDir>$(ExternalsDir)libffi\$(ArchName)\</libffiOutDir>
++    <libffiDir>$(ExternalsDir)libffi-3.3.0\</libffiDir>
++    <libffiOutDir>$(ExternalsDir)libffi-3.3.0\$(ArchName)\</libffiOutDir>
+     <libffiIncludeDir>$(libffiOutDir)include</libffiIncludeDir>
+     <opensslDir>$(ExternalsDir)openssl-1.1.1k\</opensslDir>
+     <opensslOutDir>$(ExternalsDir)openssl-bin-1.1.1k-1\$(ArchName)\</opensslOutDir>
diff --git a/var/spack/repos/builtin/packages/python/package.py b/var/spack/repos/builtin/packages/python/package.py
index 2ce0510819..cd67ac4dc3 100644
--- a/var/spack/repos/builtin/packages/python/package.py
+++ b/var/spack/repos/builtin/packages/python/package.py
@@ -4,10 +4,14 @@
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
 import glob
+import inspect
 import json
 import os
 import re
+import subprocess
 import sys
+from distutils.dir_util import copy_tree
+from shutil import copy
 
 import llnl.util.tty as tty
 from llnl.util.filesystem import get_filetype, path_contains_subdirectory
@@ -18,8 +22,12 @@ from spack.build_environment import dso_suffix
 from spack.util.environment import is_system_path
 from spack.util.prefix import Prefix
 
+arch_map = {"AMD64": "x64", "x86": "Win32",
+            "IA64": "Win32", "EM64T": "Win32"}
+is_windows = os.name == 'nt'
 
-class Python(AutotoolsPackage):
+
+class Python(Package):
     """The Python programming language."""
 
     homepage = "https://www.python.org/"
@@ -29,11 +37,19 @@ class Python(AutotoolsPackage):
 
     maintainers = ['adamjstewart', 'skosukhin', 'scheibelp', 'varioustoxins']
 
+
+    phases = ['configure', 'build', 'install']
+
+    #: phase
+    install_targets = ['install']
+    build_targets = []
+
     version('3.10.2', sha256='3c0ede893011319f9b0a56b44953a3d52c7abf9657c23fb4bc9ced93b86e9c97')
     version('3.10.1', sha256='b76117670e7c5064344b9c138e141a377e686b9063f3a8a620ff674fa8ec90d3')
     version('3.10.0', sha256='c4e0cbad57c90690cb813fb4663ef670b4d0f587d8171e2c42bd4c9245bd2758')
     version('3.9.10', sha256='1aa9c0702edbae8f6a2c95f70a49da8420aaa76b7889d3419c186bfc8c0e571e', preferred=True)
     version('3.9.9',  sha256='2cc7b67c1f3f66c571acc42479cdf691d8ed6b47bee12c9b68430413a17a44ea')
+    version('3.9.9',  sha256='2cc7b67c1f3f66c571acc42479cdf691d8ed6b47bee12c9b68430413a17a44ea')
     version('3.9.8',  sha256='7447fb8bb270942d620dd24faa7814b1383b61fa99029a240025fd81c1db8283')
     version('3.9.7',  sha256='a838d3f9360d157040142b715db34f0218e535333696a5569dc6f854604eb9d1')
     version('3.9.6',  sha256='d0a35182e19e416fc8eae25a3dcd4d02d4997333e4ad1f2eee6010aadc3fe866')
@@ -146,12 +162,12 @@ class Python(AutotoolsPackage):
         description='Enable expensive build-time optimizations, if available'
     )
     # See https://legacy.python.org/dev/peps/pep-0394/
-    variant('pythoncmd', default=True,
+    variant('pythoncmd', default=not is_windows,
             description="Symlink 'python3' executable to 'python' "
             "(not PEP 394 compliant)")
 
     # Optional Python modules
-    variant('readline', default=True,  description='Build readline module')
+    variant('readline', default=not is_windows,  description='Build readline module')
     variant('ssl',      default=True,  description='Build ssl module')
     variant('sqlite3',  default=True,  description='Build sqlite3 module')
     variant('dbm',      default=True,  description='Build dbm module')
@@ -166,33 +182,34 @@ class Python(AutotoolsPackage):
     variant('tix',      default=False, description='Build Tix module')
     variant('ensurepip', default=True, description='Build ensurepip module', when='@2.7.9:2,3.4:')
 
-    depends_on('pkgconfig@0.9.0:', type='build')
-    depends_on('gettext +libxml2', when='+libxml2')
-    depends_on('gettext ~libxml2', when='~libxml2')
-
-    # Optional dependencies
-    # See detect_modules() in setup.py for details
-    depends_on('readline', when='+readline')
-    depends_on('ncurses', when='+readline')
-    depends_on('openssl', when='+ssl')
-    # https://raw.githubusercontent.com/python/cpython/84471935ed2f62b8c5758fd544c7d37076fe0fa5/Misc/NEWS
-    # https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-4rc1
-    depends_on('openssl@:1.0.2z', when='@:2.7.13,3.0.0:3.5.2+ssl')
-    depends_on('openssl@1.0.2:', when='@3.7:+ssl')  # https://docs.python.org/3/whatsnew/3.7.html#build-changes
-    depends_on('openssl@1.1.1:', when='@3.10:+ssl')  # https://docs.python.org/3.10/whatsnew/3.10.html#build-changes
-    depends_on('sqlite@3.0.8:', when='@:3.9+sqlite3')
-    depends_on('sqlite@3.7.15:', when='@3.10:+sqlite3')  # https://docs.python.org/3.10/whatsnew/3.10.html#build-changes
-    depends_on('gdbm', when='+dbm')  # alternatively ndbm or berkeley-db
-    depends_on('libnsl', when='+nis')
-    depends_on('zlib@1.1.3:', when='+zlib')
-    depends_on('bzip2', when='+bz2')
-    depends_on('xz', when='@3.3:+lzma')
-    depends_on('expat', when='+pyexpat')
-    depends_on('libffi', when='+ctypes')
-    depends_on('tk', when='+tkinter')
-    depends_on('tcl', when='+tkinter')
-    depends_on('uuid', when='+uuid')
-    depends_on('tix', when='+tix')
+    if os.name != 'nt':
+        depends_on('pkgconfig@0.9.0:', type='build')
+        depends_on('gettext +libxml2', when='+libxml2')
+        depends_on('gettext ~libxml2', when='~libxml2')
+
+        # Optional dependencies
+        # See detect_modules() in setup.py for details
+        depends_on('readline', when='+readline')
+        depends_on('ncurses', when='+readline')
+        depends_on('openssl', when='+ssl')
+        # https://raw.githubusercontent.com/python/cpython/84471935ed2f62b8c5758fd544c7d37076fe0fa5/Misc/NEWS
+        # https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-4rc1
+        depends_on('openssl@:1.0.2z', when='@:2.7.13,3.0.0:3.5.2+ssl')
+        depends_on('openssl@1.0.2:', when='@3.7:+ssl')  # https://docs.python.org/3/whatsnew/3.7.html#build-changes
+        depends_on('openssl@1.1.1:', when='@3.10:+ssl')  # https://docs.python.org/3.10/whatsnew/3.10.html#build-changes
+        depends_on('sqlite@3.0.8:', when='@:3.9+sqlite3')
+        depends_on('sqlite@3.7.15:', when='@3.10:+sqlite3')  # https://docs.python.org/3.10/whatsnew/3.10.html#build-changes
+        depends_on('gdbm', when='+dbm')  # alternatively ndbm or berkeley-db
+        depends_on('libnsl', when='+nis')
+        depends_on('zlib@1.1.3:', when='+zlib')
+        depends_on('bzip2', when='+bz2')
+        depends_on('xz', when='@3.3:+lzma')
+        depends_on('expat', when='+pyexpat')
+        depends_on('libffi', when='+ctypes')
+        depends_on('tk', when='+tkinter')
+        depends_on('tcl', when='+tkinter')
+        depends_on('uuid', when='+uuid')
+        depends_on('tix', when='+tix')
 
     # Python needs to be patched to build extensions w/ mixed C/C++ code:
     # https://github.com/NixOS/nixpkgs/pull/19585/files
@@ -211,6 +228,7 @@ class Python(AutotoolsPackage):
     patch('python-3.7.3-distutils-C++.patch', when='@3.7.3')
     patch('python-3.7.4+-distutils-C++.patch', when='@3.7.4:')
     patch('python-3.7.4+-distutils-C++-testsuite.patch', when='@3.7.4:')
+    patch('cpython-windows-externals.patch', when='@:3.9.6 platform=windows')
 
     patch('tkinter.patch', when='@:2.8,3.3:3.7 platform=darwin')
     # Patch the setup script to deny that tcl/x11 exists rather than allowing
@@ -438,6 +456,70 @@ class Python(AutotoolsPackage):
         # allow flags to be passed through compiler wrapper
         return (flags, None, None)
 
+    @property
+    def configure_directory(self):
+        """Returns the directory where 'configure' resides.
+        :return: directory where to find configure
+        """
+        return self.stage.source_path
+
+    @property
+    def build_directory(self):
+        """Override to provide another place to build the package"""
+        return self.configure_directory
+
+    @property
+    def plat_arch(self):
+        arch = platform.machine()
+        if arch in arch_map:
+            arch = arch_map[arch]
+        return arch
+
+    @property
+    def win_build_params(self):
+        args = []
+        args.append("-p %s" % self.plat_arch)
+        if self.spec.satisfies('+debug'):
+            args.append('-d')
+        if self.spec.satisfies('~ctypes'):
+            args.append('--no-ctypes')
+        if self.spec.satisfies('~ssl'):
+            args.append('--no-ssl')
+        if self.spec.satisfies('~tkinter'):
+            args.append('--no-tkinter')
+        return args
+
+    def win_installer(self, prefix):
+        proj_root = self.stage.source_path
+        pcbuild_root = os.path.join(proj_root, "PCbuild")
+        build_root = os.path.join(pcbuild_root, platform.machine().lower())
+        include_dir = os.path.join(proj_root, "Include")
+        copy_tree(include_dir, prefix.include)
+        doc_dir = os.path.join(proj_root, "Doc")
+        copy_tree(doc_dir, prefix.Doc)
+        tools_dir = os.path.join(proj_root, "Tools")
+        copy_tree(tools_dir, prefix.Tools)
+        lib_dir = os.path.join(proj_root, "Lib")
+        copy_tree(lib_dir, prefix.Lib)
+        pyconfig = os.path.join(proj_root, "PC", "pyconfig.h")
+        copy(pyconfig, prefix.include)
+        shared_libraries = []
+        shared_libraries.extend(glob.glob("%s\\*.exe" % build_root))
+        shared_libraries.extend(glob.glob("%s\\*.dll" % build_root))
+        shared_libraries.extend(glob.glob("%s\\*.pyd" % build_root))
+        os.makedirs(prefix.DLLs)
+        for lib in shared_libraries:
+            file_name = os.path.basename(lib)
+            if file_name.endswith(".exe") or\
+                (file_name.endswith(".dll") and "python" in file_name)\
+                or "vcruntime" in file_name:
+                copy(lib, prefix)
+            else:
+                copy(lib, prefix.DLLs)
+        static_libraries = glob.glob("%s\\*.lib")
+        for lib in static_libraries:
+            copy(lib, prefix.libs)
+
     def configure_args(self):
         spec = self.spec
         config_args = []
@@ -549,6 +631,54 @@ class Python(AutotoolsPackage):
 
         return config_args
 
+    def configure(self, spec, prefix):
+        """Runs configure with the arguments specified in
+        :meth:`~spack.build_systems.autotools.AutotoolsPackage.configure_args`
+        and an appropriately set prefix.
+        """
+        with working_dir(self.build_directory, create=True):
+            if is_windows:
+                pass
+            else:
+                options = getattr(self, 'configure_flag_args', [])
+                options += ['--prefix={0}'.format(prefix)]
+                options += self.configure_args()
+                configure(*options)
+
+    def build(self, spec, prefix):
+        """Makes the build targets specified by
+        :py:attr:``~.AutotoolsPackage.build_targets``
+        """
+        # Windows builds use a batch script to drive
+        # configure and build in one step
+        with working_dir(self.build_directory):
+            if is_windows:
+                pcbuild_root = os.path.join(self.stage.source_path, "PCbuild")
+                builder_cmd = os.path.join(pcbuild_root, 'build.bat')
+                try:
+                    subprocess.check_output(  # novermin
+                        " ".join([builder_cmd] + self.win_build_params),
+                        stderr=subprocess.STDOUT
+                    )
+                except subprocess.CalledProcessError as e:
+                    raise ProcessError("Process exited with status %d" % e.returncode,
+                                       long_message=e.output.decode('utf-8'))
+            else:
+                # See https://autotools.io/automake/silent.html
+                params = ['V=1']
+                params += self.build_targets
+                inspect.getmodule(self).make(*params)
+
+    def install(self, spec, prefix):
+        """Makes the install targets specified by
+        :py:attr:``~.AutotoolsPackage.install_targets``
+        """
+        with working_dir(self.build_directory):
+            if is_windows:
+                self.win_installer(prefix)
+            else:
+                inspect.getmodule(self).make(*self.install_targets)
+
     @run_after('install')
     def filter_compilers(self):
         """Run after install to tell the configuration files and Makefiles
@@ -557,7 +687,8 @@ class Python(AutotoolsPackage):
         If this isn't done, they'll have CC and CXX set to Spack's generic
         cc and c++. We want them to be bound to whatever compiler
         they were built with."""
-
+        if is_windows:
+            return
         kwargs = {'ignore_absent': True, 'backup': False, 'string': True}
 
         filenames = [
@@ -570,6 +701,8 @@ class Python(AutotoolsPackage):
 
     @run_after('install')
     def symlink(self):
+        if is_windows:
+            return
         spec = self.spec
         prefix = self.prefix
 
@@ -759,6 +892,26 @@ class Python(AutotoolsPackage):
         Returns:
             dict: variable definitions
         """
+        # Some values set by sysconfig may not always exist on Windows, so
+        # compute Windows alternatives
+        def repair_win_sysconf(conf):
+            if is_windows:
+                conf["LIBDIR"] = os.path.join(conf["LIBDEST"], "..", "libs")
+                conf["LIBPL"] = conf["LIBDIR"]
+                conf["PYTHONFRAMEWORKPREFIX"] = ""
+                conf["LDLIBRARY"] = "python" + conf["VERSION"] + ".dll"
+                conf["LIBRARY"] = "python" + conf["VERSION"] + ".lib"
+                conf["CC"] = ""
+                conf["CXX"] = ""
+                conf["LDSHARED"] = ""
+                conf["LDCXXSHARED"] = ""
+
+            return conf
+
+        # TODO: distutils is deprecated in Python 3.10 and will be removed in
+        # Python 3.12, find a different way to access this information.
+        # Also, calling the python executable disallows us from cross-compiling,
+        # so we want to try to avoid that if possible.
         cmd = """
 import json
 from sysconfig import (
@@ -823,7 +976,7 @@ config.update(get_paths())
                 config.update(json.loads(self.command('-c', cmd, output=str)))
             except (ProcessError, RuntimeError):
                 pass
-            self._config_vars[dag_hash] = config
+            self._config_vars[dag_hash] = repair_win_sysconf(config)
         return self._config_vars[dag_hash]
 
     def get_sysconfigdata_name(self):
@@ -865,6 +1018,9 @@ config.update(get_paths())
         # In Ubuntu 16.04.6 and python 2.7.12 from the system, lib could be
         # in LBPL
         # https://mail.python.org/pipermail/python-dev/2013-April/125733.html
+        # LIBPL does not exist in Windows, avoid uneccesary KeyError while allowing
+        # later failures.
+        # Return empty string rather than none so os.path doesn't complain
         libpl = self.config_vars['LIBPL']
 
         # The system Python installation on macOS and Homebrew installations
@@ -881,7 +1037,7 @@ config.update(get_paths())
 
         if '+shared' in self.spec:
             ldlibrary = self.config_vars['LDLIBRARY']
-
+            win_bin_dir = self.config_vars['BINDIR']
             if os.path.exists(os.path.join(libdir, ldlibrary)):
                 return LibraryList(os.path.join(libdir, ldlibrary))
             elif os.path.exists(os.path.join(libpl, ldlibrary)):
@@ -891,6 +1047,9 @@ config.update(get_paths())
             elif macos_developerdir and \
                     os.path.exists(os.path.join(macos_developerdir, ldlibrary)):
                 return LibraryList(os.path.join(macos_developerdir, ldlibrary))
+            elif is_windows and \
+                    os.path.exists(os.path.join(win_bin_dir, ldlibrary)):
+                return LibraryList(os.path.join(win_bin_dir, ldlibrary))
             else:
                 msg = 'Unable to locate {0} libraries in {1}'
                 raise RuntimeError(msg.format(ldlibrary, libdir))
@@ -1075,7 +1234,7 @@ config.update(get_paths())
             # fact that LDSHARED is set in the environment, therefore we export
             # the variable only if the new value is different from what we got
             # from the sysconfigdata file:
-            if config_link != new_link:
+            if config_link != new_link and not is_windows:
                 env.set(link_var, new_link)
 
     def setup_dependent_run_environment(self, env, dependent_spec):
@@ -1211,7 +1370,8 @@ config.update(get_paths())
                                         ))
 
     def add_files_to_view(self, view, merge_map):
-        bin_dir = self.spec.prefix.bin
+        bin_dir = self.spec.prefix.bin if os.name != 'nt'\
+            else self.spec.prefix
         for src, dst in merge_map.items():
             if not path_contains_subdirectory(src, bin_dir):
                 view.link(src, dst, spec=self.spec)
@@ -1243,7 +1403,8 @@ config.update(get_paths())
                 view.link(new_link_target, dst, spec=self.spec)
 
     def remove_files_from_view(self, view, merge_map):
-        bin_dir = self.spec.prefix.bin
+        bin_dir = self.spec.prefix.bin if os.name != 'nt'\
+            else self.spec.prefix
         for src, dst in merge_map.items():
             if not path_contains_subdirectory(src, bin_dir):
                 view.remove_file(src, dst)
diff --git a/var/spack/repos/builtin/packages/ruby/package.py b/var/spack/repos/builtin/packages/ruby/package.py
index 870a416283..b4ca1afaff 100644
--- a/var/spack/repos/builtin/packages/ruby/package.py
+++ b/var/spack/repos/builtin/packages/ruby/package.py
@@ -5,8 +5,12 @@
 
 import re
 
+from spack import *
 
-class Ruby(AutotoolsPackage):
+is_windows = str(spack.platforms.host()) == 'windows'
+
+
+class Ruby(Package):
     """A dynamic, open source programming language with a focus on
     simplicity and productivity."""
 
@@ -27,23 +31,22 @@ class Ruby(AutotoolsPackage):
     version('2.5.3', sha256='9828d03852c37c20fa333a0264f2490f07338576734d910ee3fd538c9520846c')
     version('2.2.0', sha256='7671e394abfb5d262fbcd3b27a71bf78737c7e9347fa21c39e58b0bb9c4840fc')
 
-    variant('openssl', default=True, description="Enable OpenSSL support")
-    variant('readline', default=False, description="Enable Readline support")
+    if not is_windows:
+        variant('openssl', default=True, description="Enable OpenSSL support")
+        variant('readline', default=False, description="Enable Readline support")
+        depends_on('pkgconfig', type=('build'))
+        depends_on('libffi')
+        depends_on('libx11', when='@:2.3')
+        depends_on('tcl', when='@:2.3')
+        depends_on('tk', when='@:2.3')
+        depends_on('readline', when='+readline')
+        depends_on('zlib')
+        with when('+openssl'):
+            depends_on('openssl@:1')
+            depends_on('openssl@:1.0', when='@:2.3')
 
     extendable = True
-
-    depends_on('pkgconfig', type=('build'))
-    depends_on('libffi')
-    depends_on('zlib')
-    depends_on('libx11', when='@:2.3')
-    depends_on('tcl', when='@:2.3')
-    depends_on('tk', when='@:2.3')
-    depends_on('readline', when='+readline')
-
-    with when('+openssl'):
-        depends_on('openssl@:1')
-        depends_on('openssl@:1.0', when='@:2.3')
-
+    phases = ['autoreconf', 'configure', 'build', 'install']
     # Known build issues when Avira antivirus software is running:
     # https://github.com/rvm/rvm/issues/4313#issuecomment-374020379
     # TODO: add check for this and warn user
@@ -116,6 +119,32 @@ class Ruby(AutotoolsPackage):
         module.gem  = Executable(self.prefix.bin.gem)
         module.rake = Executable(self.prefix.bin.rake)
 
+    def configure(self, spec, prefix):
+        with working_dir(self.build_directory, create=True):
+            if is_windows:
+                Executable("win32\\configure.bat", "--prefix=%s" % self.prefix)
+            else:
+                options = getattr(self, 'configure_flag_args', [])
+                options += ['--prefix={0}'.format(prefix)]
+                options += self.configure_args()
+                configure(*options)
+
+    def build(self, spec, prefix):
+        with working_dir(self.build_directory):
+            if is_windows:
+                nmake()
+            else:
+                params = ['V=1']
+                params += self.build_targets
+                make(*params)
+
+    def install(self, spec, prefix):
+        with working_dir(self.build_directory):
+            if is_windows:
+                nmake('install')
+            else:
+                make(*self.install_targets)
+
     @run_after('install')
     def post_install(self):
         """ RubyGems updated their SSL certificates at some point, so
diff --git a/var/spack/repos/builtin/packages/zlib/package.py b/var/spack/repos/builtin/packages/zlib/package.py
index 9a445b8173..3b6b1fd18d 100644
--- a/var/spack/repos/builtin/packages/zlib/package.py
+++ b/var/spack/repos/builtin/packages/zlib/package.py
@@ -6,7 +6,11 @@
 
 # Although zlib comes with a configure script, it does not use Autotools
 # The AutotoolsPackage causes zlib to fail to build with PGI
-class Zlib(CMakePackage):
+import glob
+import os
+
+
+class Zlib(Package):
     """A free, general-purpose, legally unencumbered lossless
     data-compression library.
     """
@@ -37,16 +41,29 @@ class Zlib(CMakePackage):
             ['libz'], root=self.prefix, recursive=True, shared=shared
         )
 
-    def cmake_args(self):
-        args = ['-DBUILD_SHARED_LIBS:BOOL=' +
-                ('ON' if self._building_shared else 'OFF')]
-        return args
+    def win_install(self):
+        build_dir = self.stage.source_path
+        install_tree = {}
+        install_tree["bin"] = glob.glob(os.path.join(build_dir, "*.dll"))
+        install_tree["lib"] = glob.glob(os.path.join(build_dir, "*.lib"))
+        compose_src_path = lambda x: os.path.join(build_dir, x)
+        install_tree["include"] = [compose_src_path("zlib.h"),
+                                   compose_src_path("zconf.h")]
+        install_tree["share"] = {"man": {"man3": [compose_src_path("zlib.3")]}}
 
-    @property
-    def build_directory(self):
-        return join_path(self.stage.source_path,
-                         'spack-build-shared' if self._building_shared
-                         else 'spack-build-static')
+        def installtree(dst, tree):
+            for inst_dir in tree:
+                if type(tree[inst_dir]) is list:
+                    install_dst = getattr(dst, inst_dir)
+                    try:
+                        os.makedirs(install_dst)
+                    except OSError:
+                        pass
+                    for file in tree[inst_dir]:
+                        copy(file, install_dst)
+                else:
+                    installtree(getattr(dst, inst_dir), tree[inst_dir])
+        installtree(self.prefix, install_tree)
 
     def setup_build_environment(self, env):
         if '+pic' in self.spec:
@@ -54,27 +71,10 @@ class Zlib(CMakePackage):
         if '+optimize' in self.spec:
             env.append_flags('CFLAGS', '-O2')
 
-    # Build, install, and check both static and shared versions of the
-    # libraries when +shared
-    @when('+shared platform=windows')
-    def cmake(self, spec, prefix):
-        for self._building_shared in (False, True):
-            super(Zlib, self).cmake(spec, prefix)
-
-    @when('+shared platform=windows')
-    def build(self, spec, prefix):
-        for self._building_shared in (False, True):
-            super(Zlib, self).build(spec, prefix)
-
-    @when('+shared platform=windows')
-    def check(self):
-        for self._building_shared in (False, True):
-            super(Zlib, self).check()
-
     def install(self, spec, prefix):
-        if 'platform=windows' in self.spec and '+shared' in self.spec:
-            for self._building_shared in (False, True):
-                super(Zlib, self).install(spec, prefix)
+        if 'platform=windows' in self.spec:
+            nmake('-f' 'win32\\Makefile.msc')
+            self.win_install()
         else:
             config_args = []
             if '~shared' in spec: