xref: /third_party/python/patches/cpython_mingw_v3.11.4.patch

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100755
index 0000000..c2293cb
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,418 @@
+name: Tests
+
+# gh-84728: "paths-ignore" is not used to skip documentation-only PRs, because
+# it prevents to mark a job as mandatory. A PR cannot be merged if a job is
+# mandatory but not scheduled because of "paths-ignore".
+on:
+  workflow_dispatch:
+  push:
+    branches:
+    - 'main'
+    - '3.11'
+    - '3.10'
+    - '3.9'
+    - '3.8'
+    - '3.7'
+  pull_request:
+    branches:
+    - 'main'
+    - '3.11'
+    - '3.10'
+    - '3.9'
+    - '3.8'
+    - '3.7'
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  check_source:
+    name: 'Check for source changes'
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    outputs:
+      run_tests: ${{ steps.check.outputs.run_tests }}
+      run_ssl_tests: ${{ steps.check.outputs.run_ssl_tests }}
+      config_hash: ${{ steps.config_hash.outputs.hash }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Check for source changes
+        id: check
+        run: |
+          if [ -z "$GITHUB_BASE_REF" ]; then
+            echo "run_tests=true" >> $GITHUB_OUTPUT
+            echo "run_ssl_tests=true" >> $GITHUB_OUTPUT
+          else
+            git fetch origin $GITHUB_BASE_REF --depth=1
+            # git diff "origin/$GITHUB_BASE_REF..." (3 dots) may be more
+            # reliable than git diff "origin/$GITHUB_BASE_REF.." (2 dots),
+            # but it requires to download more commits (this job uses
+            # "git fetch --depth=1").
+            #
+            # git diff "origin/$GITHUB_BASE_REF..." (3 dots) works with Git
+            # 2.26, but Git 2.28 is stricter and fails with "no merge base".
+            #
+            # git diff "origin/$GITHUB_BASE_REF.." (2 dots) should be enough on
+            # GitHub, since GitHub starts by merging origin/$GITHUB_BASE_REF
+            # into the PR branch anyway.
+            #
+            # https://github.com/python/core-workflow/issues/373
+            git diff --name-only origin/$GITHUB_BASE_REF.. | grep -qvE '(\.rst$|^Doc|^Misc)' && echo "run_tests=true" >> $GITHUB_OUTPUT || true
+            git diff --name-only origin/$GITHUB_BASE_REF.. | grep -qE '(ssl|hashlib|hmac|^.github)' && echo "run_ssl_tests=true" >> $GITHUB_OUTPUT || true
+          fi
+      - name: Compute hash for config cache key
+        id: config_hash
+        run: |
+          echo "hash=${{ hashFiles('configure', 'configure.ac', '.github/workflows/build.yml') }}" >> $GITHUB_OUTPUT
+
+  check_abi:
+    name: 'Check if the ABI has changed'
+    runs-on: ubuntu-20.04
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+      - name: Install Dependencies
+        run: |
+            sudo ./.github/workflows/posix-deps-apt.sh
+            sudo apt-get install -yq abigail-tools
+      - name: Build CPython
+        env:
+          CFLAGS: -g3 -O0
+        run: |
+          # Build Python with the libpython dynamic library
+          ./configure --enable-shared
+          make -j4
+      - name: Check for changes in the ABI
+        id: check
+        run: |
+          if ! make check-abidump; then
+            echo "Generated ABI file is not up to date."
+            echo "Please, add the release manager of this branch as a reviewer of this PR."
+            echo ""
+            echo "The up to date ABI file should be attached to this build as an artifact."
+            echo ""
+            echo "To learn more about this check: https://devguide.python.org/setup/#regenerate-the-abi-dump"
+            echo ""
+            exit 1
+          fi
+      - name: Generate updated ABI files
+        if: ${{ failure() && steps.check.conclusion == 'failure' }}
+        run: |
+          make regen-abidump
+      - uses: actions/upload-artifact@v3
+        name: Publish updated ABI files
+        if: ${{ failure() && steps.check.conclusion == 'failure' }}
+        with:
+          name: abi-data
+          path: ./Doc/data/*.abi
+
+  check_generated_files:
+    name: 'Check if generated files are up to date'
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    steps:
+      - uses: actions/checkout@v3
+      - name: Restore config.cache
+        uses: actions/cache@v3
+        with:
+          path: config.cache
+          key: ${{ github.job }}-${{ runner.os }}-${{ needs.check_source.outputs.config_hash }}
+      - uses: actions/setup-python@v3
+      - name: Install Dependencies
+        run: sudo ./.github/workflows/posix-deps-apt.sh
+      - name: Add ccache to PATH
+        run: echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
+      - name: Configure ccache action
+        uses: hendrikmuhs/ccache-action@v1.2
+      - name: Check Autoconf version 2.69 and aclocal 1.16.3
+        run: |
+          grep "Generated by GNU Autoconf 2.69" configure
+          grep "aclocal 1.16.3" aclocal.m4
+          grep -q "runstatedir" configure
+          grep -q "PKG_PROG_PKG_CONFIG" aclocal.m4
+      - name: Configure CPython
+        run: |
+          # Build Python with the libpython dynamic library
+          ./configure --config-cache --with-pydebug --enable-shared
+      - name: Regenerate autoconf files with container image
+        run: make regen-configure
+      - name: Build CPython
+        run: |
+          # Deepfreeze will usually cause global objects to be added or removed,
+          # so we run it before regen-global-objects gets rum (in regen-all).
+          make regen-deepfreeze
+          make -j4 regen-all
+          make regen-stdlib-module-names
+      - name: Check for changes
+        run: |
+          git add -u
+          changes=$(git status --porcelain)
+          # Check for changes in regenerated files
+          if test -n "$changes"; then
+            echo "Generated files not up to date."
+            echo "Perhaps you forgot to run make regen-all or build.bat --regen. ;)"
+            echo "configure files must be regenerated with a specific version of autoconf."
+            echo "$changes"
+            echo ""
+            git diff --staged || true
+            exit 1
+          fi
+      - name: Check exported libpython symbols
+        run: make smelly
+      - name: Check limited ABI symbols
+        run: make check-limited-abi
+
+  build_win32:
+    name: 'Windows (x86)'
+    runs-on: windows-latest
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    env:
+       IncludeUwp: 'true'
+    steps:
+    - uses: actions/checkout@v3
+    - name: Build CPython
+      run: .\PCbuild\build.bat -e -d -p Win32
+    - name: Display build info
+      run: .\python.bat -m test.pythoninfo
+    - name: Tests
+      run: .\PCbuild\rt.bat -p Win32 -d -q -uall -u-cpu -rwW --slowest --timeout=1200 -j0
+
+  build_win_amd64:
+    name: 'Windows (x64)'
+    runs-on: windows-latest
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    env:
+       IncludeUwp: 'true'
+    steps:
+    - uses: actions/checkout@v3
+    - name: Register MSVC problem matcher
+      run: echo "::add-matcher::.github/problem-matchers/msvc.json"
+    - name: Build CPython
+      run: .\PCbuild\build.bat -e -d -p x64
+    - name: Display build info
+      run: .\python.bat -m test.pythoninfo
+    - name: Tests
+      run: .\PCbuild\rt.bat -p x64 -d -q -uall -u-cpu -rwW --slowest --timeout=1200 -j0
+
+  build_macos:
+    name: 'macOS'
+    runs-on: macos-latest
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    env:
+      HOMEBREW_NO_ANALYTICS: 1
+      HOMEBREW_NO_AUTO_UPDATE: 1
+      HOMEBREW_NO_INSTALL_CLEANUP: 1
+      PYTHONSTRICTEXTENSIONBUILD: 1
+    steps:
+    - uses: actions/checkout@v3
+    - name: Restore config.cache
+      uses: actions/cache@v3
+      with:
+        path: config.cache
+        key: ${{ github.job }}-${{ runner.os }}-${{ needs.check_source.outputs.config_hash }}
+    - name: Install Homebrew dependencies
+      run: brew install pkg-config openssl@1.1 xz gdbm tcl-tk
+    - name: Configure CPython
+      run: |
+        CFLAGS="-I$(brew --prefix gdbm)/include -I$(brew --prefix xz)/include" \
+        LDFLAGS="-L$(brew --prefix gdbm)/lib -I$(brew --prefix xz)/lib" \
+        PKG_CONFIG_PATH="$(brew --prefix tcl-tk)/lib/pkgconfig" \
+        ./configure \
+          --config-cache \
+          --with-pydebug \
+          --prefix=/opt/python-dev \
+          --with-openssl="$(brew --prefix openssl@1.1)"
+    - name: Build CPython
+      run: make -j4
+    - name: Display build info
+      run: make pythoninfo
+    - name: Tests
+      run: make buildbottest TESTOPTS="-j4 -uall,-cpu"
+
+  build_ubuntu:
+    name: 'Ubuntu'
+    runs-on: ubuntu-20.04
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    env:
+      OPENSSL_VER: 1.1.1u
+      PYTHONSTRICTEXTENSIONBUILD: 1
+    steps:
+    - uses: actions/checkout@v3
+    - name: Register gcc problem matcher
+      run: echo "::add-matcher::.github/problem-matchers/gcc.json"
+    - name: Install Dependencies
+      run: sudo ./.github/workflows/posix-deps-apt.sh
+    - name: Configure OpenSSL env vars
+      run: |
+        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> $GITHUB_ENV
+        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> $GITHUB_ENV
+    - name: 'Restore OpenSSL build'
+      id: cache-openssl
+      uses: actions/cache@v3
+      with:
+        path: ./multissl/openssl/${{ env.OPENSSL_VER }}
+        key: ${{ runner.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
+    - name: Install OpenSSL
+      if: steps.cache-openssl.outputs.cache-hit != 'true'
+      run: python3 Tools/ssl/multissltests.py --steps=library --base-directory $MULTISSL_DIR --openssl $OPENSSL_VER --system Linux
+    - name: Add ccache to PATH
+      run: |
+        echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
+    - name: Configure ccache action
+      uses: hendrikmuhs/ccache-action@v1.2
+    - name: Setup directory envs for out-of-tree builds
+      run: |
+        echo "CPYTHON_RO_SRCDIR=$(realpath -m ${GITHUB_WORKSPACE}/../cpython-ro-srcdir)" >> $GITHUB_ENV
+        echo "CPYTHON_BUILDDIR=$(realpath -m ${GITHUB_WORKSPACE}/../cpython-builddir)" >> $GITHUB_ENV
+    - name: Create directories for read-only out-of-tree builds
+      run: mkdir -p $CPYTHON_RO_SRCDIR $CPYTHON_BUILDDIR
+    - name: Bind mount sources read-only
+      run: sudo mount --bind -o ro $GITHUB_WORKSPACE $CPYTHON_RO_SRCDIR
+    - name: Restore config.cache
+      uses: actions/cache@v3
+      with:
+        path: ${{ env.CPYTHON_BUILDDIR }}/config.cache
+        key: ${{ github.job }}-${{ runner.os }}-${{ needs.check_source.outputs.config_hash }}
+    - name: Configure CPython out-of-tree
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
+      run: |
+        ../cpython-ro-srcdir/configure \
+          --config-cache \
+          --with-pydebug \
+          --with-openssl=$OPENSSL_DIR
+    - name: Build CPython out-of-tree
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
+      run: make -j4
+    - name: Display build info
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
+      run: make pythoninfo
+    - name: Remount sources writable for tests
+      # some tests write to srcdir, lack of pyc files slows down testing
+      run: sudo mount $CPYTHON_RO_SRCDIR -oremount,rw
+    - name: Tests
+      working-directory: ${{ env.CPYTHON_BUILDDIR }}
+      run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"
+
+  build_ubuntu_ssltests:
+    name: 'Ubuntu SSL tests with OpenSSL'
+    runs-on: ubuntu-20.04
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true' && needs.check_source.outputs.run_ssl_tests == 'true'
+    strategy:
+      fail-fast: false
+      matrix:
+        openssl_ver: [1.1.1u, 3.0.9, 3.1.1]
+    env:
+      OPENSSL_VER: ${{ matrix.openssl_ver }}
+      MULTISSL_DIR: ${{ github.workspace }}/multissl
+      OPENSSL_DIR: ${{ github.workspace }}/multissl/openssl/${{ matrix.openssl_ver }}
+      LD_LIBRARY_PATH: ${{ github.workspace }}/multissl/openssl/${{ matrix.openssl_ver }}/lib
+    steps:
+    - uses: actions/checkout@v3
+    - name: Restore config.cache
+      uses: actions/cache@v3
+      with:
+        path: config.cache
+        key: ${{ github.job }}-${{ runner.os }}-${{ needs.check_source.outputs.config_hash }}
+    - name: Register gcc problem matcher
+      run: echo "::add-matcher::.github/problem-matchers/gcc.json"
+    - name: Install Dependencies
+      run: sudo ./.github/workflows/posix-deps-apt.sh
+    - name: Configure OpenSSL env vars
+      run: |
+        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> $GITHUB_ENV
+        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> $GITHUB_ENV
+    - name: 'Restore OpenSSL build'
+      id: cache-openssl
+      uses: actions/cache@v3
+      with:
+        path: ./multissl/openssl/${{ env.OPENSSL_VER }}
+        key: ${{ runner.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
+    - name: Install OpenSSL
+      if: steps.cache-openssl.outputs.cache-hit != 'true'
+      run: python3 Tools/ssl/multissltests.py --steps=library --base-directory $MULTISSL_DIR --openssl $OPENSSL_VER --system Linux
+    - name: Add ccache to PATH
+      run: |
+        echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
+    - name: Configure ccache action
+      uses: hendrikmuhs/ccache-action@v1.2
+    - name: Configure CPython
+      run: ./configure --config-cache --with-pydebug --with-openssl=$OPENSSL_DIR
+    - name: Build CPython
+      run: make -j4
+    - name: Display build info
+      run: make pythoninfo
+    - name: SSL tests
+      run: ./python Lib/test/ssltests.py
+
+  build_asan:
+    name: 'Address sanitizer'
+    runs-on: ubuntu-20.04
+    timeout-minutes: 60
+    needs: check_source
+    if: needs.check_source.outputs.run_tests == 'true'
+    env:
+      OPENSSL_VER: 1.1.1u
+      PYTHONSTRICTEXTENSIONBUILD: 1
+      ASAN_OPTIONS: detect_leaks=0:allocator_may_return_null=1:handle_segv=0
+    steps:
+    - uses: actions/checkout@v3
+    - name: Restore config.cache
+      uses: actions/cache@v3
+      with:
+        path: config.cache
+        key: ${{ github.job }}-${{ runner.os }}-${{ needs.check_source.outputs.config_hash }}
+    - name: Register gcc problem matcher
+      run: echo "::add-matcher::.github/problem-matchers/gcc.json"
+    - name: Install Dependencies
+      run: sudo ./.github/workflows/posix-deps-apt.sh
+    - name: Set up GCC-10 for ASAN
+      uses: egor-tensin/setup-gcc@v1
+      with:
+        version: 10
+    - name: Configure OpenSSL env vars
+      run: |
+        echo "MULTISSL_DIR=${GITHUB_WORKSPACE}/multissl" >> $GITHUB_ENV
+        echo "OPENSSL_DIR=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}" >> $GITHUB_ENV
+        echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> $GITHUB_ENV
+    - name: 'Restore OpenSSL build'
+      id: cache-openssl
+      uses: actions/cache@v3
+      with:
+        path: ./multissl/openssl/${{ env.OPENSSL_VER }}
+        key: ${{ runner.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
+    - name: Install OpenSSL
+      if: steps.cache-openssl.outputs.cache-hit != 'true'
+      run: python3 Tools/ssl/multissltests.py --steps=library --base-directory $MULTISSL_DIR --openssl $OPENSSL_VER --system Linux
+    - name: Add ccache to PATH
+      run: |
+        echo "PATH=/usr/lib/ccache:$PATH" >> $GITHUB_ENV
+    - name: Configure ccache action
+      uses: hendrikmuhs/ccache-action@v1.2
+    - name: Configure CPython
+      run: ./configure --config-cache --with-address-sanitizer --without-pymalloc
+    - name: Build CPython
+      run: make -j4
+    - name: Display build info
+      run: make pythoninfo
+    - name: Tests
+      run: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"
diff --git a/.gitignore b/.gitignore
index 0ddfd71..d42e111 100644
--- a/.gitignore
+++ b/.gitignore
@@ -114,6 +114,7 @@ PCbuild/win32/
 Tools/unicode/data/
 /autom4te.cache
 /build/
+/builddir/
 /config.cache
 /config.log
 /config.status
@@ -150,6 +151,3 @@ Python/frozen_modules/MANIFEST
 # Ignore ./python binary on Unix but still look into ./Python/ directory.
 /python
 !/Python/
-
-# main branch only: ABI files are not checked/maintained
-Doc/data/python*.abi
diff --git a/Include/bytesobject.h b/Include/bytesobject.h
index 4c4dc40..cd88bed 100644
--- a/Include/bytesobject.h
+++ b/Include/bytesobject.h
@@ -35,9 +35,9 @@ PyAPI_FUNC(PyObject *) PyBytes_FromStringAndSize(const char *, Py_ssize_t);
 PyAPI_FUNC(PyObject *) PyBytes_FromString(const char *);
 PyAPI_FUNC(PyObject *) PyBytes_FromObject(PyObject *);
 PyAPI_FUNC(PyObject *) PyBytes_FromFormatV(const char*, va_list)
-                                Py_GCC_ATTRIBUTE((format(printf, 1, 0)));
+                                Py_PRINTF(1, 0);
 PyAPI_FUNC(PyObject *) PyBytes_FromFormat(const char*, ...)
-                                Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
+                                Py_PRINTF(1, 2);
 PyAPI_FUNC(Py_ssize_t) PyBytes_Size(PyObject *);
 PyAPI_FUNC(char *) PyBytes_AsString(PyObject *);
 PyAPI_FUNC(PyObject *) PyBytes_Repr(PyObject *, int);
diff --git a/Include/fileobject.h b/Include/fileobject.h
index 4c983e7..260e4c1 100644
--- a/Include/fileobject.h
+++ b/Include/fileobject.h
@@ -30,7 +30,7 @@ PyAPI_DATA(int) Py_UTF8Mode;
 #endif
 
 /* A routine to check if a file descriptor can be select()-ed. */
-#ifdef _MSC_VER
+#ifdef MS_WINDOWS
     /* On Windows, any socket fd can be select()-ed, no matter how high */
     #define _PyIsSelectable_fd(FD) (1)
 #else
diff --git a/Include/internal/pycore_condvar.h b/Include/internal/pycore_condvar.h
index 981c962..ed9e6a7 100644
--- a/Include/internal/pycore_condvar.h
+++ b/Include/internal/pycore_condvar.h
@@ -5,6 +5,12 @@
 #  error "this header requires Py_BUILD_CORE define"
 #endif
 
+#ifdef __MINGW32__
+# if !defined(HAVE_PTHREAD_H) || defined(NT_THREADS)
+#  undef _POSIX_THREADS
+# endif
+#endif
+
 #ifndef _POSIX_THREADS
 /* This means pthreads are not implemented in libc headers, hence the macro
    not present in unistd.h. But they still can be implemented as an external
@@ -39,6 +45,10 @@
 /* include windows if it hasn't been done before */
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+/* winpthreads are involved via windows header, so need undef _POSIX_THREADS after header include */
+#if defined(_POSIX_THREADS)
+#undef _POSIX_THREADS
+#endif
 
 /* options */
 /* non-emulated condition variables are provided for those that want
diff --git a/Include/iscygpty.h b/Include/iscygpty.h
new file mode 100755
index 0000000..82fd0af
--- /dev/null
+++ b/Include/iscygpty.h
@@ -0,0 +1,41 @@
+/*
+ * iscygpty.h -- part of ptycheck
+ * https://github.com/k-takata/ptycheck
+ *
+ * Copyright (c) 2015-2017 K.Takata
+ *
+ * You can redistribute it and/or modify it under the terms of either
+ * the MIT license (as described below) or the Vim license.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _ISCYGPTY_H
+#define _ISCYGPTY_H
+
+#ifdef _WIN32
+int is_cygpty(int fd);
+int is_cygpty_used(void);
+#else
+#define is_cygpty(fd)		0
+#define is_cygpty_used()	0
+#endif
+
+#endif /* _ISCYGPTY_H */
diff --git a/Include/osdefs.h b/Include/osdefs.h
index 3243944..99d4977 100644
--- a/Include/osdefs.h
+++ b/Include/osdefs.h
@@ -10,7 +10,6 @@ extern "C" {
 #ifdef MS_WINDOWS
 #define SEP L'\\'
 #define ALTSEP L'/'
-#define MAXPATHLEN 256
 #define DELIM L';'
 #endif
 
diff --git a/Include/py_curses.h b/Include/py_curses.h
index b2c7f1b..e6fc813 100644
--- a/Include/py_curses.h
+++ b/Include/py_curses.h
@@ -36,6 +36,13 @@
 #include <curses.h>
 #endif
 
+#if defined(__MINGW32__)
+#include <windows.h>
+#if !defined(_ISPAD)
+#define _ISPAD 0x10
+#endif
+#endif
+
 #ifdef HAVE_NCURSES_H
 /* configure was checking <curses.h>, but we will
    use <ncurses.h>, which has some or all these features. */
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index 34e3de3..fb71fde 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -315,9 +315,9 @@ PyAPI_FUNC(int) PyUnicodeTranslateError_SetReason(
     );
 
 PyAPI_FUNC(int) PyOS_snprintf(char *str, size_t size, const char  *format, ...)
-                        Py_GCC_ATTRIBUTE((format(printf, 3, 4)));
+                        Py_PRINTF(3, 4);
 PyAPI_FUNC(int) PyOS_vsnprintf(char *str, size_t size, const char  *format, va_list va)
-                        Py_GCC_ATTRIBUTE((format(printf, 3, 0)));
+                        Py_PRINTF(3, 0);
 
 #ifndef Py_LIMITED_API
 #  define Py_CPYTHON_ERRORS_H
diff --git a/Include/pylifecycle.h b/Include/pylifecycle.h
index e4c3b09..21346ba 100644
--- a/Include/pylifecycle.h
+++ b/Include/pylifecycle.h
@@ -21,6 +21,15 @@ PyAPI_FUNC(int) Py_IsInitialized(void);
 PyAPI_FUNC(PyThreadState *) Py_NewInterpreter(void);
 PyAPI_FUNC(void) Py_EndInterpreter(PyThreadState *);
 
+PyAPI_FUNC(wchar_t) Py_GetAltSepW(const wchar_t *);
+PyAPI_FUNC(wchar_t) Py_GetSepW(const wchar_t *);
+PyAPI_FUNC(char) Py_GetSepA(const char *);
+
+PyAPI_FUNC(void) Py_NormalizeSepsW(wchar_t *);
+PyAPI_FUNC(void) Py_NormalizeSepsA(char *);
+
+PyAPI_FUNC(void) Py_NormalizeSepsPathcchW(wchar_t *);
+
 
 /* Py_PyAtExit is for the atexit module, Py_AtExit is for low-level
  * exit functions.
diff --git a/Include/pyport.h b/Include/pyport.h
index 93250f4..b816c90 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -53,6 +53,21 @@
 #endif
 
 
+#ifdef __MINGW32__
+/* Translate GCC[mingw*] platform specific defines to those
+ * used in python code.
+ */
+#if !defined(MS_WIN64) && defined(_WIN64)
+#  define MS_WIN64
+#endif
+#if !defined(MS_WIN32) && defined(_WIN32)
+#  define MS_WIN32
+#endif
+#if !defined(MS_WINDOWS) && defined(MS_WIN32)
+#  define MS_WINDOWS
+#endif
+#endif /* __MINGW32__*/
+
 /**************************************************************************
 Symbols and macros to supply platform-independent interfaces to basic
 C language & library operations whose spellings vary across platforms.
@@ -509,12 +524,12 @@ extern char * _getpty(int *, int, mode_t, int);
 */
 
 /*
-  All windows ports, except cygwin, are handled in PC/pyconfig.h.
+  Only MSVC windows ports is handled in PC/pyconfig.h.
 
-  Cygwin is the only other autoconf platform requiring special
+  Cygwin and Mingw is the only other autoconf platform requiring special
   linkage handling and it uses __declspec().
 */
-#if defined(__CYGWIN__)
+#if defined(__CYGWIN__) || defined(__MINGW32__)
 #       define HAVE_DECLSPEC_DLL
 #endif
 
@@ -527,21 +542,23 @@ extern char * _getpty(int *, int, mode_t, int);
 #                       define PyAPI_FUNC(RTYPE) Py_EXPORTED_SYMBOL RTYPE
 #                       define PyAPI_DATA(RTYPE) extern Py_EXPORTED_SYMBOL RTYPE
         /* module init functions inside the core need no external linkage */
-        /* except for Cygwin to handle embedding */
-#                       if defined(__CYGWIN__)
+        /* except for Cygwin/Mingw to handle embedding */
+#                       if defined(__CYGWIN__) || defined(__MINGW32__)
 #                               define PyMODINIT_FUNC Py_EXPORTED_SYMBOL PyObject*
-#                       else /* __CYGWIN__ */
+#                       else /* __CYGWIN__ || __MINGW32__*/
 #                               define PyMODINIT_FUNC PyObject*
-#                       endif /* __CYGWIN__ */
+#                       endif /* __CYGWIN__ || __MINGW32__*/
 #               else /* Py_BUILD_CORE */
         /* Building an extension module, or an embedded situation */
         /* public Python functions and data are imported */
         /* Under Cygwin, auto-import functions to prevent compilation */
         /* failures similar to those described at the bottom of 4.1: */
         /* http://docs.python.org/extending/windows.html#a-cookbook-approach */
-#                       if !defined(__CYGWIN__)
+#                       if defined(__CYGWIN__) || defined(__MINGW32__)
+#                               define PyAPI_FUNC(RTYPE) RTYPE
+#                       else
 #                               define PyAPI_FUNC(RTYPE) Py_IMPORTED_SYMBOL RTYPE
-#                       endif /* !__CYGWIN__ */
+#                       endif /* __CYGWIN__ || __MINGW32__*/
 #                       define PyAPI_DATA(RTYPE) extern Py_IMPORTED_SYMBOL RTYPE
         /* module init functions outside the core must be exported */
 #                       if defined(__cplusplus)
@@ -641,6 +658,12 @@ extern char * _getpty(int *, int, mode_t, int);
 
 #define Py_VA_COPY va_copy
 
+#if defined(__GNUC__) && ((__GNUC__ == 4 && __GNUC_MINOR__>= 4) || __GNUC__ > 4)
+#  define Py_PRINTF(X,Y) Py_GCC_ATTRIBUTE((format(gnu_printf,X,Y)))
+#else
+#  define Py_PRINTF(X,Y) Py_GCC_ATTRIBUTE((format(printf,X,Y))) 
+#endif
+
 /*
  * Convenient macros to deal with endianness of the platform. WORDS_BIGENDIAN is
  * detected by configure and defined in pyconfig.h. The code in pyconfig.h
diff --git a/Include/pythread.h b/Include/pythread.h
index a483290..9bf8bd6 100644
--- a/Include/pythread.h
+++ b/Include/pythread.h
@@ -7,6 +7,12 @@ typedef void *PyThread_type_lock;
 extern "C" {
 #endif
 
+#ifdef __MINGW32__
+# if !defined(HAVE_PTHREAD_H) || defined(NT_THREADS)
+#  undef _POSIX_THREADS
+# endif
+#endif
+
 /* Return status codes for Python lock acquisition.  Chosen for maximum
  * backwards compatibility, ie failure -> 0, success -> 1.  */
 typedef enum PyLockStatus {
diff --git a/Include/sysmodule.h b/Include/sysmodule.h
index b508711..d6767dc 100644
--- a/Include/sysmodule.h
+++ b/Include/sysmodule.h
@@ -15,9 +15,9 @@ Py_DEPRECATED(3.11) PyAPI_FUNC(void) PySys_SetArgvEx(int, wchar_t **, int);
 Py_DEPRECATED(3.11) PyAPI_FUNC(void) PySys_SetPath(const wchar_t *);
 
 PyAPI_FUNC(void) PySys_WriteStdout(const char *format, ...)
-                 Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
+                 Py_PRINTF(1, 2);
 PyAPI_FUNC(void) PySys_WriteStderr(const char *format, ...)
-                 Py_GCC_ATTRIBUTE((format(printf, 1, 2)));
+                 Py_PRINTF(1, 2);
 PyAPI_FUNC(void) PySys_FormatStdout(const char *format, ...);
 PyAPI_FUNC(void) PySys_FormatStderr(const char *format, ...);
 
diff --git a/Lib/compileall.py b/Lib/compileall.py
index a388931..069ea2b 100644
--- a/Lib/compileall.py
+++ b/Lib/compileall.py
@@ -38,6 +38,8 @@ def _walk_dir(dir, maxlevels, quiet=0):
         if name == '__pycache__':
             continue
         fullname = os.path.join(dir, name)
+        if sys.platform == "win32" and sys.version.find("GCC") >= 0:
+            fullname = fullname.replace('\\','/')
         if not os.path.isdir(fullname):
             yield fullname
         elif (maxlevels > 0 and name != os.curdir and name != os.pardir and
diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py
index 26135ad..76d583b 100644
--- a/Lib/ctypes/__init__.py
+++ b/Lib/ctypes/__init__.py
@@ -458,7 +458,9 @@ def LoadLibrary(self, name):
 cdll = LibraryLoader(CDLL)
 pydll = LibraryLoader(PyDLL)
 
-if _os.name == "nt":
+if _os.name == "nt" and _sys.version.find('GCC') >= 0:
+    pythonapi = PyDLL("libpython%d.%d%s.dll" % (_sys.version_info[:2] + (_sys.abiflags,)), None)
+elif _os.name == "nt":
     pythonapi = PyDLL("python dll", None, _sys.dllhandle)
 elif _sys.platform == "cygwin":
     pythonapi = PyDLL("libpython%d.%d.dll" % _sys.version_info[:2])
diff --git a/Lib/ctypes/util.py b/Lib/ctypes/util.py
index 0c2510e..48ddb3b 100644
--- a/Lib/ctypes/util.py
+++ b/Lib/ctypes/util.py
@@ -31,6 +31,12 @@ def _get_build_version():
         # else we don't know what version of the compiler this is
         return None
 
+    def find_msvcrt_mingw():
+        is_ucrt = 'clang' in sys.version.lower() or 'ucrt' in sys.version.lower()
+        if is_ucrt:
+            return None
+        return 'msvcrt.dll'
+
     def find_msvcrt():
         """Return the name of the VC runtime dll"""
         version = _get_build_version()
@@ -54,6 +60,9 @@ def find_msvcrt():
 
     def find_library(name):
         if name in ('c', 'm'):
+            import sysconfig
+            if sysconfig.get_platform().startswith('mingw'):
+                return find_msvcrt_mingw()
             return find_msvcrt()
         # See MSDN for the REAL search order.
         for directory in os.environ['PATH'].split(os.pathsep):
diff --git a/Lib/distutils/ccompiler.py b/Lib/distutils/ccompiler.py
index 4c47f2e..ab61a86 100644
--- a/Lib/distutils/ccompiler.py
+++ b/Lib/distutils/ccompiler.py
@@ -9,7 +9,7 @@
 from distutils.file_util import move_file
 from distutils.dir_util import mkpath
 from distutils.dep_util import newer_group
-from distutils.util import split_quoted, execute
+from distutils.util import split_quoted, execute, get_platform
 from distutils import log
 
 class CCompiler:
@@ -948,6 +948,8 @@ def get_default_compiler(osname=None, platform=None):
         osname = os.name
     if platform is None:
         platform = sys.platform
+    if get_platform().startswith('mingw'):
+        return 'mingw32'
     for pattern, compiler in _default_compilers:
         if re.match(pattern, platform) is not None or \
            re.match(pattern, osname) is not None:
diff --git a/Lib/distutils/command/build_ext.py b/Lib/distutils/command/build_ext.py
index f287b34..e87e3ad 100644
--- a/Lib/distutils/command/build_ext.py
+++ b/Lib/distutils/command/build_ext.py
@@ -186,7 +186,7 @@ def finalize_options(self):
         # for extensions under windows use different directories
         # for Release and Debug builds.
         # also Python's library directory must be appended to library_dirs
-        if os.name == 'nt':
+        if os.name == 'nt' and not self.plat_name.startswith(('mingw')):
             # the 'libs' directory is for binary installs - we assume that
             # must be the *native* platform.  But we don't really support
             # cross-compiling via a binary install anyway, so we let it go.
@@ -218,15 +218,16 @@ def finalize_options(self):
 
         # For extensions under Cygwin, Python's library directory must be
         # appended to library_dirs
-        if sys.platform[:6] == 'cygwin':
-            if sys.executable.startswith(os.path.join(sys.exec_prefix, "bin")):
+        if sys.platform[:6] == 'cygwin' or self.plat_name.startswith(('mingw')):
+            if not sysconfig.python_build:
                 # building third party extensions
+                config_dir_name = os.path.basename(sysconfig.get_config_var('LIBPL'))
                 self.library_dirs.append(os.path.join(sys.prefix, "lib",
                                                       "python" + get_python_version(),
-                                                      "config"))
+                                                      config_dir_name))
             else:
                 # building python standard extensions
-                self.library_dirs.append('.')
+                self.library_dirs.append(sysconfig.project_base)
 
         # For building extensions with a shared Python library,
         # Python's library directory must be appended to library_dirs
@@ -237,7 +238,7 @@ def finalize_options(self):
                 self.library_dirs.append(sysconfig.get_config_var('LIBDIR'))
             else:
                 # building python standard extensions
-                self.library_dirs.append('.')
+                self.library_dirs.append(sysconfig.project_base)
 
         # The argument parsing will result in self.define being a string, but
         # it has to be a list of 2-tuples.  All the preprocessor symbols
@@ -712,6 +713,20 @@ def get_libraries(self, ext):
         # pyconfig.h that MSVC groks.  The other Windows compilers all seem
         # to need it mentioned explicitly, though, so that's what we do.
         # Append '_d' to the python import library on debug builds.
+
+        # Use self.plat_name as it works even in case of
+        # cross-compilation (at least for mingw build).
+        if self.plat_name.startswith('mingw'):
+            from distutils import sysconfig
+            extra = []
+            for lib in (
+                sysconfig.get_config_var('BLDLIBRARY').split()
+                + sysconfig.get_config_var('SHLIBS').split()
+                ):
+                if lib.startswith('-l'):
+                    extra.append(lib[2:])
+            return ext.libraries + extra
+
         if sys.platform == "win32":
             from distutils._msvccompiler import MSVCCompiler
             if not isinstance(self.compiler, MSVCCompiler):
diff --git a/Lib/distutils/command/install.py b/Lib/distutils/command/install.py
index 01d5331..25eb3d8 100644
--- a/Lib/distutils/command/install.py
+++ b/Lib/distutils/command/install.py
@@ -72,8 +72,8 @@
     INSTALL_SCHEMES['nt_user'] = {
         'purelib': '$usersite',
         'platlib': '$usersite',
-        'headers': '$userbase/Python$py_version_nodot/Include/$dist_name',
-        'scripts': '$userbase/Python$py_version_nodot/Scripts',
+        'headers': '$userbase/include/python$py_version_short_plat$abiflags/$dist_name',
+        'scripts': '$userbase/bin',
         'data'   : '$userbase',
         }
 
@@ -81,7 +81,7 @@
         'purelib': '$usersite',
         'platlib': '$usersite',
         'headers':
-            '$userbase/include/python$py_version_short$abiflags/$dist_name',
+            '$userbase/include/python$py_version_short_plat$abiflags/$dist_name',
         'scripts': '$userbase/bin',
         'data'   : '$userbase',
         }
@@ -311,6 +311,7 @@ def finalize_options(self):
                             'py_version': py_version,
                             'py_version_short': '%d.%d' % sys.version_info[:2],
                             'py_version_nodot': '%d%d' % sys.version_info[:2],
+                            'py_version_short_plat': f'{sys.version_info[0]}.{sys.version_info[1]}-{get_platform()}' if os.name == 'nt' and 'gcc' in sys.version.lower() else f'{sys.version_info[0]}.{sys.version_info[1]}',
                             'sys_prefix': prefix,
                             'prefix': prefix,
                             'sys_exec_prefix': exec_prefix,
@@ -363,7 +364,8 @@ def finalize_options(self):
 
         # Convert directories from Unix /-separated syntax to the local
         # convention.
-        self.convert_paths('lib', 'purelib', 'platlib',
+        self.convert_paths('base', 'platbase',
+                           'lib', 'purelib', 'platlib',
                            'scripts', 'data', 'headers')
         if HAS_USER_SITE:
             self.convert_paths('userbase', 'usersite')
diff --git a/Lib/distutils/cygwinccompiler.py b/Lib/distutils/cygwinccompiler.py
index 66c12dd..d8c8428 100644
--- a/Lib/distutils/cygwinccompiler.py
+++ b/Lib/distutils/cygwinccompiler.py
@@ -44,12 +44,13 @@
 #   (ld supports -shared)
 # * mingw gcc 3.2/ld 2.13 works
 #   (ld supports -shared)
+# * llvm-mingw with Clang 11 works
+#   (lld supports -shared)
 
 import os
 import sys
 import copy
-from subprocess import Popen, PIPE, check_output
-import re
+import shlex
 
 from distutils.unixccompiler import UnixCCompiler
 from distutils.file_util import write_file
@@ -57,6 +58,7 @@
         CompileError, UnknownFileError)
 from distutils.version import LooseVersion
 from distutils.spawn import find_executable
+from subprocess import Popen, check_output
 
 def get_msvcr():
     """Include the appropriate MSVC runtime library if Python was built
@@ -91,6 +93,7 @@ class CygwinCCompiler(UnixCCompiler):
     obj_extension = ".o"
     static_lib_extension = ".a"
     shared_lib_extension = ".dll"
+    dylib_lib_extension = ".dll.a"
     static_lib_format = "lib%s%s"
     shared_lib_format = "%s%s"
     exe_extension = ".exe"
@@ -109,50 +112,28 @@ def __init__(self, verbose=0, dry_run=0, force=0):
                 "Compiling may fail because of undefined preprocessor macros."
                 % details)
 
-        self.gcc_version, self.ld_version, self.dllwrap_version = \
-            get_versions()
-        self.debug_print(self.compiler_type + ": gcc %s, ld %s, dllwrap %s\n" %
-                         (self.gcc_version,
-                          self.ld_version,
-                          self.dllwrap_version) )
-
-        # ld_version >= "2.10.90" and < "2.13" should also be able to use
-        # gcc -mdll instead of dllwrap
-        # Older dllwraps had own version numbers, newer ones use the
-        # same as the rest of binutils ( also ld )
-        # dllwrap 2.10.90 is buggy
-        if self.ld_version >= "2.10.90":
-            self.linker_dll = "gcc"
-        else:
-            self.linker_dll = "dllwrap"
+        self.cc = os.environ.get('CC', 'gcc')
+        self.cxx = os.environ.get('CXX', 'g++')
 
-        # ld_version >= "2.13" support -shared so use it instead of
-        # -mdll -static
-        if self.ld_version >= "2.13":
-            shared_option = "-shared"
-        else:
-            shared_option = "-mdll -static"
-
-        # Hard-code GCC because that's what this is all about.
-        # XXX optimization, warnings etc. should be customizable.
-        self.set_executables(compiler='gcc -mcygwin -O -Wall',
-                             compiler_so='gcc -mcygwin -mdll -O -Wall',
-                             compiler_cxx='g++ -mcygwin -O -Wall',
-                             linker_exe='gcc -mcygwin',
+        # Older numpy dependend on this existing to check for ancient
+        # gcc versions. This doesn't make much sense with clang etc so
+        # just hardcode to something recent.
+        # https://github.com/numpy/numpy/pull/20333
+        self.gcc_version = LooseVersion("11.2.0")
+
+        self.linker_dll = self.cc
+        shared_option = "-shared"
+
+        self.set_executables(compiler='%s -mcygwin -O -Wall' % self.cc,
+                             compiler_so='%s -mcygwin -mdll -O -Wall' % self.cc,
+                             compiler_cxx='%s -mcygwin -O -Wall' % self.cxx,
+                             linker_exe='%s -mcygwin' % self.cc,
                              linker_so=('%s -mcygwin %s' %
                                         (self.linker_dll, shared_option)))
 
-        # cygwin and mingw32 need different sets of libraries
-        if self.gcc_version == "2.91.57":
-            # cygwin shouldn't need msvcrt, but without the dlls will crash
-            # (gcc version 2.91.57) -- perhaps something about initialization
-            self.dll_libraries=["msvcrt"]
-            self.warn(
-                "Consider upgrading to a newer version of gcc")
-        else:
-            # Include the appropriate MSVC runtime library if Python was built
-            # with MSVC 7.0 or later.
-            self.dll_libraries = get_msvcr()
+        # Include the appropriate MSVC runtime library if Python was built
+        # with MSVC 7.0 or later.
+        self.dll_libraries = get_msvcr()
 
     def _compile(self, obj, src, ext, cc_args, extra_postargs, pp_opts):
         """Compiles the source by spawning GCC and windres if needed."""
@@ -162,6 +143,28 @@ def _compile(self, obj, src, ext, cc_args, extra_postargs, pp_opts):
                 self.spawn(["windres", "-i", src, "-o", obj])
             except DistutilsExecError as msg:
                 raise CompileError(msg)
+        elif ext == '.mc':
+            # Adapted from msvc9compiler:
+            #
+            # Compile .MC to .RC file to .RES file.
+            #   * '-h dir' specifies the directory for the generated include file
+            #   * '-r dir' specifies the target directory of the generated RC file and the binary message resource it includes
+            #
+            # For now (since there are no options to change this),
+            # we use the source-directory for the include file and
+            # the build directory for the RC file and message
+            # resources. This works at least for win32all.
+            h_dir = os.path.dirname(src)
+            rc_dir = os.path.dirname(obj)
+            try:
+                # first compile .MC to .RC and .H file
+                self.spawn(['windmc'] + ['-h', h_dir, '-r', rc_dir] + [src])
+                base, _ = os.path.splitext(os.path.basename(src))
+                rc_file = os.path.join(rc_dir, base + '.rc')
+                # then compile .RC to .RES file
+                self.spawn(['windres', '-i', rc_file, '-o', obj])
+            except DistutilsExecError as msg:
+                raise CompileError(msg)
         else: # for other files use the C-compiler
             try:
                 self.spawn(self.compiler_so + cc_args + [src, '-o', obj] +
@@ -214,28 +217,21 @@ def link(self, target_desc, objects, output_filename, output_dir=None,
 
             # next add options for def-file and to creating import libraries
 
-            # dllwrap uses different options than gcc/ld
-            if self.linker_dll == "dllwrap":
-                extra_preargs.extend(["--output-lib", lib_file])
-                # for dllwrap we have to use a special option
-                extra_preargs.extend(["--def", def_file])
-            # we use gcc/ld here and can be sure ld is >= 2.9.10
-            else:
-                # doesn't work: bfd_close build\...\libfoo.a: Invalid operation
-                #extra_preargs.extend(["-Wl,--out-implib,%s" % lib_file])
-                # for gcc/ld the def-file is specified as any object files
-                objects.append(def_file)
+            # doesn't work: bfd_close build\...\libfoo.a: Invalid operation
+            #extra_preargs.extend(["-Wl,--out-implib,%s" % lib_file])
+            # for gcc/ld the def-file is specified as any object files
+            objects.append(def_file)
 
         #end: if ((export_symbols is not None) and
         #        (target_desc != self.EXECUTABLE or self.linker_dll == "gcc")):
 
         # who wants symbols and a many times larger output file
         # should explicitly switch the debug mode on
-        # otherwise we let dllwrap/ld strip the output file
+        # otherwise we let ld strip the output file
         # (On my machine: 10KiB < stripped_file < ??100KiB
         #   unstripped_file = stripped_file + XXX KiB
         #  ( XXX=254 for a typical python extension))
-        if not debug:
+        if not debug and not hasattr(sys, 'gettotalrefcount'):
             extra_preargs.append("-s")
 
         UnixCCompiler.link(self, target_desc, objects, output_filename,
@@ -253,11 +249,16 @@ def object_filenames(self, source_filenames, strip_dir=0, output_dir=''):
             output_dir = ''
         obj_names = []
         for src_name in source_filenames:
-            # use normcase to make sure '.rc' is really '.rc' and not '.RC'
-            base, ext = os.path.splitext(os.path.normcase(src_name))
-            if ext not in (self.src_extensions + ['.rc','.res']):
+            base, ext = os.path.splitext(src_name)
+            # use 'normcase' only for resource suffixes
+            ext_normcase = os.path.normcase(ext)
+            if ext_normcase in ['.rc', '.res', '.mc']:
+                ext = ext_normcase
+            if ext not in (self.src_extensions + ['.rc', '.res', '.mc']):
                 raise UnknownFileError("unknown file type '%s' (from '%s')" % \
                       (ext, src_name))
+            base = os.path.splitdrive(base)[1] # Chop off the drive
+            base = base[os.path.isabs(base):]  # If abs, chop off leading /
             if strip_dir:
                 base = os.path.basename (base)
             if ext in ('.res', '.rc'):
@@ -279,31 +280,18 @@ def __init__(self, verbose=0, dry_run=0, force=0):
 
         CygwinCCompiler.__init__ (self, verbose, dry_run, force)
 
-        # ld_version >= "2.13" support -shared so use it instead of
-        # -mdll -static
-        if self.ld_version >= "2.13":
-            shared_option = "-shared"
-        else:
-            shared_option = "-mdll -static"
-
-        # A real mingw32 doesn't need to specify a different entry point,
-        # but cygwin 2.91.57 in no-cygwin-mode needs it.
-        if self.gcc_version <= "2.91.57":
-            entry_point = '--entry _DllMain@12'
-        else:
-            entry_point = ''
+        shared_option = "-shared"
 
-        if is_cygwingcc():
+        if is_cygwincc(self.cc):
             raise CCompilerError(
                 'Cygwin gcc cannot be used with --compiler=mingw32')
 
-        self.set_executables(compiler='gcc -O -Wall',
-                             compiler_so='gcc -mdll -O -Wall',
-                             compiler_cxx='g++ -O -Wall',
-                             linker_exe='gcc',
-                             linker_so='%s %s %s'
-                                        % (self.linker_dll, shared_option,
-                                           entry_point))
+        self.set_executables(compiler='%s -O2 -Wall' % self.cc,
+                             compiler_so='%s -mdll -O2 -Wall' % self.cc,
+                             compiler_cxx='%s -O2 -Wall' % self.cxx,
+                             linker_exe='%s' % self.cc,
+                             linker_so='%s %s'
+                                        % (self.linker_dll, shared_option))
         # Maybe we should also append -mthreads, but then the finished
         # dlls need another dll (mingwm10.dll see Mingw32 docs)
         # (-mthreads: Support thread-safe exception handling on `Mingw32')
@@ -313,7 +301,7 @@ def __init__(self, verbose=0, dry_run=0, force=0):
 
         # Include the appropriate MSVC runtime library if Python was built
         # with MSVC 7.0 or later.
-        self.dll_libraries = get_msvcr()
+        self.dll_libraries = get_msvcr() or []
 
 # Because these compilers aren't configured in Python's pyconfig.h file by
 # default, we should at least warn the user if he is using an unmodified
@@ -351,6 +339,10 @@ def check_config_h():
     if "GCC" in sys.version:
         return CONFIG_H_OK, "sys.version mentions 'GCC'"
 
+    # Clang would also work
+    if "Clang" in sys.version:
+        return CONFIG_H_OK, "sys.version mentions 'Clang'"
+
     # let's see if __GNUC__ is mentioned in python.h
     fn = sysconfig.get_config_h_filename()
     try:
@@ -366,38 +358,8 @@ def check_config_h():
         return (CONFIG_H_UNCERTAIN,
                 "couldn't read '%s': %s" % (fn, exc.strerror))
 
-RE_VERSION = re.compile(br'(\d+\.\d+(\.\d+)*)')
-
-def _find_exe_version(cmd):
-    """Find the version of an executable by running `cmd` in the shell.
-
-    If the command is not found, or the output does not match
-    `RE_VERSION`, returns None.
-    """
-    executable = cmd.split()[0]
-    if find_executable(executable) is None:
-        return None
-    out = Popen(cmd, shell=True, stdout=PIPE).stdout
-    try:
-        out_string = out.read()
-    finally:
-        out.close()
-    result = RE_VERSION.search(out_string)
-    if result is None:
-        return None
-    # LooseVersion works with strings
-    # so we need to decode our bytes
-    return LooseVersion(result.group(1).decode())
-
-def get_versions():
-    """ Try to find out the versions of gcc, ld and dllwrap.
-
-    If not possible it returns None for it.
-    """
-    commands = ['gcc -dumpversion', 'ld -v', 'dllwrap --version']
-    return tuple([_find_exe_version(cmd) for cmd in commands])
 
-def is_cygwingcc():
-    '''Try to determine if the gcc that would be used is from cygwin.'''
-    out_string = check_output(['gcc', '-dumpmachine'])
+def is_cygwincc(cc):
+    '''Try to determine if the compiler that would be used is from cygwin.'''
+    out_string = check_output(shlex.split(cc) + ['-dumpmachine'])
     return out_string.strip().endswith(b'cygwin')
diff --git a/Lib/distutils/msvc9compiler.py b/Lib/distutils/msvc9compiler.py
index a7976fb..c341679 100644
--- a/Lib/distutils/msvc9compiler.py
+++ b/Lib/distutils/msvc9compiler.py
@@ -291,8 +291,6 @@ def query_vcvarsall(version, arch="x86"):
 
 # More globals
 VERSION = get_build_version()
-if VERSION < 8.0:
-    raise DistutilsPlatformError("VC %0.1f is not supported by this module" % VERSION)
 # MACROS = MacroExpander(VERSION)
 
 class MSVCCompiler(CCompiler) :
@@ -327,6 +325,8 @@ class MSVCCompiler(CCompiler) :
 
     def __init__(self, verbose=0, dry_run=0, force=0):
         CCompiler.__init__ (self, verbose, dry_run, force)
+        if VERSION < 8.0:
+            raise DistutilsPlatformError("VC %0.1f is not supported by this module" % VERSION)
         self.__version = VERSION
         self.__root = r"Software\Microsoft\VisualStudio"
         # self.__macros = MACROS
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index 03b8558..024c15c 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -64,8 +64,23 @@ def parse_config_h(fp, g=None):
 
 _python_build = partial(is_python_build, check_home=True)
 _init_posix = partial(sysconfig_init_posix, _config_vars)
-_init_nt = partial(_init_non_posix, _config_vars)
 
+def _posix_build():
+    # GCC[mingw*] use posix build system
+    # Check for cross builds explicitly
+    host_platform = os.environ.get("_PYTHON_HOST_PLATFORM")
+    if host_platform:
+        if host_platform.startswith('mingw'):
+            return True
+    return os.name == 'posix' or \
+        (os.name == "nt" and 'GCC' in sys.version)
+posix_build = _posix_build()
+
+
+def _init_nt():
+    if posix_build:
+        return _init_posix(_config_vars)
+    return _init_non_posix(_config_vars)
 
 # Similar function is also implemented in sysconfig as _parse_makefile
 # but without the parsing capabilities of distutils.text_file.TextFile.
@@ -196,7 +211,23 @@ def customize_compiler(compiler):
     Mainly needed on Unix, so we can plug in the information that
     varies across Unices and is stored in Python's Makefile.
     """
-    if compiler.compiler_type == "unix":
+    global _config_vars
+    if compiler.compiler_type in ["cygwin", "mingw32"]:
+        # Note that cygwin use posix build and 'unix' compiler.
+        # If build is not based on posix then we must predefine
+        # some environment variables corresponding to posix
+        # build rules and defaults.
+        if not 'GCC' in sys.version:
+            _config_vars['CC'] = "gcc"
+            _config_vars['CXX'] = "g++"
+            _config_vars['OPT'] = "-fwrapv -O3 -Wall -Wstrict-prototypes"
+            _config_vars['CFLAGS'] = ""
+            _config_vars['CCSHARED'] = ""
+            _config_vars['LDSHARED'] = "gcc -shared -Wl,--enable-auto-image-base"
+            _config_vars['AR'] = "ar"
+            _config_vars['ARFLAGS'] = "rc"
+
+    if compiler.compiler_type in ["unix", "cygwin", "mingw32"]:
         if sys.platform == "darwin":
             # Perform first-time customization of compiler-related
             # config vars on OS X now that we know we need a compiler.
@@ -274,7 +305,7 @@ def get_python_inc(plat_specific=0, prefix=None):
     """
     if prefix is None:
         prefix = plat_specific and BASE_EXEC_PREFIX or BASE_PREFIX
-    if os.name == "posix":
+    if posix_build:
         if python_build:
             # Assume the executable is in the build directory.  The
             # pyconfig.h file should be in the same directory.  Since
@@ -321,7 +352,7 @@ def get_python_lib(plat_specific=0, standard_lib=0, prefix=None):
         else:
             prefix = plat_specific and EXEC_PREFIX or PREFIX
 
-    if os.name == "posix":
+    if posix_build:
         if plat_specific or standard_lib:
             # Platform-specific modules (any module from a non-pure-Python
             # module distribution) or standard Python library modules.
diff --git a/Lib/distutils/tests/test_cygwinccompiler.py b/Lib/distutils/tests/test_cygwinccompiler.py
index 0912ffd..a93c174 100644
--- a/Lib/distutils/tests/test_cygwinccompiler.py
+++ b/Lib/distutils/tests/test_cygwinccompiler.py
@@ -8,7 +8,7 @@
 from distutils import cygwinccompiler
 from distutils.cygwinccompiler import (check_config_h,
                                        CONFIG_H_OK, CONFIG_H_NOTOK,
-                                       CONFIG_H_UNCERTAIN, get_versions,
+                                       CONFIG_H_UNCERTAIN,
                                        get_msvcr)
 from distutils.tests import support
 
@@ -81,40 +81,6 @@ def test_check_config_h(self):
         self.write_file(self.python_h, 'xxx __GNUC__ xxx')
         self.assertEqual(check_config_h()[0], CONFIG_H_OK)
 
-    def test_get_versions(self):
-
-        # get_versions calls distutils.spawn.find_executable on
-        # 'gcc', 'ld' and 'dllwrap'
-        self.assertEqual(get_versions(), (None, None, None))
-
-        # Let's fake we have 'gcc' and it returns '3.4.5'
-        self._exes['gcc'] = b'gcc (GCC) 3.4.5 (mingw special)\nFSF'
-        res = get_versions()
-        self.assertEqual(str(res[0]), '3.4.5')
-
-        # and let's see what happens when the version
-        # doesn't match the regular expression
-        # (\d+\.\d+(\.\d+)*)
-        self._exes['gcc'] = b'very strange output'
-        res = get_versions()
-        self.assertEqual(res[0], None)
-
-        # same thing for ld
-        self._exes['ld'] = b'GNU ld version 2.17.50 20060824'
-        res = get_versions()
-        self.assertEqual(str(res[1]), '2.17.50')
-        self._exes['ld'] = b'@(#)PROGRAM:ld  PROJECT:ld64-77'
-        res = get_versions()
-        self.assertEqual(res[1], None)
-
-        # and dllwrap
-        self._exes['dllwrap'] = b'GNU dllwrap 2.17.50 20060824\nFSF'
-        res = get_versions()
-        self.assertEqual(str(res[2]), '2.17.50')
-        self._exes['dllwrap'] = b'Cheese Wrap'
-        res = get_versions()
-        self.assertEqual(res[2], None)
-
     def test_get_msvcr(self):
 
         # none
diff --git a/Lib/distutils/unixccompiler.py b/Lib/distutils/unixccompiler.py
index d00c489..76a7d82 100644
--- a/Lib/distutils/unixccompiler.py
+++ b/Lib/distutils/unixccompiler.py
@@ -249,9 +249,13 @@ def runtime_library_dir_option(self, dir):
                 # -Wl whenever gcc was used in the past it is probably
                 # safest to keep doing so.
                 if sysconfig.get_config_var("GNULD") == "yes":
-                    # GNU ld needs an extra option to get a RUNPATH
+                    # GNU ELF ld needs an extra option to get a RUNPATH
                     # instead of just an RPATH.
-                    return "-Wl,--enable-new-dtags,-R" + dir
+                    if sys.platform in ["win32", "cygwin"] or \
+                       "mingw" in compiler:
+                        return []
+                    else:
+                        return "-Wl,--enable-new-dtags,-R" + dir
                 else:
                     return "-Wl,-R" + dir
             else:
diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index 2ce5c5b..81626b3 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -37,6 +37,22 @@ def get_host_platform():
 
     """
     if os.name == 'nt':
+        if 'gcc' in sys.version.lower():
+            if 'ucrt' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_ucrt'
+                return 'mingw_i686_ucrt'
+            if 'clang' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_clang'
+                if 'arm64' in sys.version.lower():
+                    return 'mingw_aarch64'
+                if 'arm' in sys.version.lower():
+                    return 'mingw_armv7'
+                return 'mingw_i686_clang'
+            if 'amd64' in sys.version.lower():
+                return 'mingw_x86_64'
+            return 'mingw_i686'
         if 'amd64' in sys.version.lower():
             return 'win-amd64'
         if '(arm)' in sys.version.lower():
@@ -130,6 +146,13 @@ def convert_path (pathname):
         paths.remove('.')
     if not paths:
         return os.curdir
+    # On Windows, if paths is ['C:','folder','subfolder'] then
+    # os.path.join(*paths) will return 'C:folder\subfolder' which
+    # is thus relative to the CWD on that drive. So we work around
+    # this by adding a \ to path[0]
+    if (len(paths) > 0 and paths[0].endswith(':') and
+        sys.platform == "win32" and sys.version.find("GCC") >= 0):
+        paths[0] += '\\'
     return os.path.join(*paths)
 
 # convert_path ()
@@ -140,6 +163,10 @@ def change_root (new_root, pathname):
     relative, this is equivalent to "os.path.join(new_root,pathname)".
     Otherwise, it requires making 'pathname' relative and then joining the
     two, which is tricky on DOS/Windows and Mac OS.
+
+    If on Windows or OS/2 and both new_root and pathname are on different
+    drives, raises DistutilsChangeRootError as this is nonsensical,
+    otherwise use drive which can be in either of new_root or pathname.
     """
     if os.name == 'posix':
         if not os.path.isabs(pathname):
@@ -149,9 +176,20 @@ def change_root (new_root, pathname):
 
     elif os.name == 'nt':
         (drive, path) = os.path.splitdrive(pathname)
-        if path[0] == '\\':
+        if path[0] == os.sep:
             path = path[1:]
-        return os.path.join(new_root, path)
+        (drive_r, path_r) = os.path.splitdrive(new_root)
+        if path_r and path_r[0] == os.sep:
+            path_r = path_r[1:]
+        drive_used = ''
+        if len(drive) == 2 and len(drive_r) == 2 and drive != drive_r:
+            raise DistutilsChangeRootError("root and pathname not on same drive (%s, %s)"
+                   % (drive_r,drive))
+        elif len(drive_r) == 2:
+            drive_used = drive_r+os.sep
+        elif len(drive) == 2:
+            drive_used = drive+os.sep
+        return os.path.join(drive_used+path_r, path)
 
     else:
         raise DistutilsPlatformError("nothing known about platform '%s'" % os.name)
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py
index f603a89..7693d05 100644
--- a/Lib/importlib/_bootstrap_external.py
+++ b/Lib/importlib/_bootstrap_external.py
@@ -42,6 +42,10 @@
     path_separators = ['\\', '/']
 else:
     path_separators = ['/']
+
+if _os.environ.get('MSYSTEM', ''):
+    path_separators = path_separators[::-1]
+
 # Assumption made in _path_join()
 assert all(len(sep) == 1 for sep in path_separators)
 path_sep = path_separators[0]
diff --git a/Lib/ntpath.py b/Lib/ntpath.py
index 0444b0f..0bc5956 100644
--- a/Lib/ntpath.py
+++ b/Lib/ntpath.py
@@ -11,9 +11,7 @@
 curdir = '.'
 pardir = '..'
 extsep = '.'
-sep = '\\'
 pathsep = ';'
-altsep = '/'
 defpath = '.;C:\\bin'
 devnull = 'nul'
 
@@ -23,6 +21,14 @@
 import genericpath
 from genericpath import *
 
+if sys.platform == "win32" and os.environ.get("MSYSTEM", ""):
+    sep = '/'
+    altsep = '\\'
+else:
+    sep = '\\'
+    altsep = '/'
+bsep = str.encode(sep)
+baltsep = str.encode(altsep)
 
 __all__ = ["normcase","isabs","join","splitdrive","split","splitext",
            "basename","dirname","commonprefix","getsize","getmtime",
@@ -34,9 +40,33 @@
 
 def _get_bothseps(path):
     if isinstance(path, bytes):
-        return b'\\/'
+        return bsep+baltsep
+    else:
+        return sep+altsep
+
+def _get_sep(path):
+    if isinstance(path, bytes):
+        return bsep
+    else:
+        return sep
+
+def _get_altsep(path):
+    if isinstance(path, bytes):
+        return baltsep
+    else:
+        return altsep
+
+def _get_colon(path):
+    if isinstance(path, bytes):
+        return b':'
+    else:
+        return ':'
+
+def _get_unc_prefix(path):
+    if isinstance(path, bytes):
+        return b'\\\\?\\UNC\\'
     else:
-        return '\\/'
+        return '\\\\?\\UNC\\'
 
 # Normalize the case of a pathname and map slashes to backslashes.
 # Other normalizations (such as optimizing '../' away) are not done
@@ -58,14 +88,14 @@ def normcase(s):
             return s
         if isinstance(s, bytes):
             encoding = sys.getfilesystemencoding()
-            s = s.decode(encoding, 'surrogateescape').replace('/', '\\')
+            s = s.decode(encoding, 'surrogateescape').replace(altsep, sep)
             s = _LCMapStringEx(_LOCALE_NAME_INVARIANT,
                                _LCMAP_LOWERCASE, s)
             return s.encode(encoding, 'surrogateescape')
         else:
             return _LCMapStringEx(_LOCALE_NAME_INVARIANT,
                                   _LCMAP_LOWERCASE,
-                                  s.replace('/', '\\'))
+                                  s.replace(altsep, sep))
 except ImportError:
     def normcase(s):
         """Normalize case of pathname.
@@ -74,8 +104,8 @@ def normcase(s):
         """
         s = os.fspath(s)
         if isinstance(s, bytes):
-            return os.fsencode(os.fsdecode(s).replace('/', '\\').lower())
-        return s.replace('/', '\\').lower()
+            return os.fsencode(os.fsdecode(s).replace(altsep, sep).lower())
+        return s.replace(altsep, sep).lower()
 
 
 # Return whether a path is absolute.
@@ -87,14 +117,9 @@ def normcase(s):
 def isabs(s):
     """Test whether a path is absolute"""
     s = os.fspath(s)
-    if isinstance(s, bytes):
-        sep = b'\\'
-        altsep = b'/'
-        colon_sep = b':\\'
-    else:
-        sep = '\\'
-        altsep = '/'
-        colon_sep = ':\\'
+    sep = _get_sep(s)
+    altsep = _get_altsep(s)
+    colon_sep = _get_colon(s) + sep
     s = s[:3].replace(altsep, sep)
     # Absolute: UNC, device, and paths with a drive and root.
     # LEGACY BUG: isabs("/x") should be false since the path has no drive.
@@ -106,14 +131,9 @@ def isabs(s):
 # Join two (or more) paths.
 def join(path, *paths):
     path = os.fspath(path)
-    if isinstance(path, bytes):
-        sep = b'\\'
-        seps = b'\\/'
-        colon = b':'
-    else:
-        sep = '\\'
-        seps = '\\/'
-        colon = ':'
+    sep = _get_sep(path)
+    seps = _get_bothseps(path)
+    colon = _get_colon(path)
     try:
         if not paths:
             path[:0] + sep  #23780: Ensure compatible data type even if p is null.
@@ -172,16 +192,10 @@ def splitdrive(p):
     """
     p = os.fspath(p)
     if len(p) >= 2:
-        if isinstance(p, bytes):
-            sep = b'\\'
-            altsep = b'/'
-            colon = b':'
-            unc_prefix = b'\\\\?\\UNC\\'
-        else:
-            sep = '\\'
-            altsep = '/'
-            colon = ':'
-            unc_prefix = '\\\\?\\UNC\\'
+        sep = _get_sep(p)
+        altsep = _get_altsep(p)
+        colon = _get_colon(p)
+        unc_prefix = _get_unc_prefix(p)
         normp = p.replace(altsep, sep)
         if normp[0:2] == sep * 2:
             # UNC drives, e.g. \\server\share or \\?\UNC\server\share
@@ -231,9 +245,9 @@ def split(p):
 def splitext(p):
     p = os.fspath(p)
     if isinstance(p, bytes):
-        return genericpath._splitext(p, b'\\', b'/', b'.')
+        return genericpath._splitext(p, bsep, baltsep, b'.')
     else:
-        return genericpath._splitext(p, '\\', '/', '.')
+        return genericpath._splitext(p, sep, altsep, '.')
 splitext.__doc__ = genericpath._splitext.__doc__
 
 
@@ -334,7 +348,7 @@ def expanduser(path):
     if 'USERPROFILE' in os.environ:
         userhome = os.environ['USERPROFILE']
     elif not 'HOMEPATH' in os.environ:
-        return path
+        return os.path.normpath(path)
     else:
         try:
             drive = os.environ['HOMEDRIVE']
@@ -361,7 +375,7 @@ def expanduser(path):
     if isinstance(path, bytes):
         userhome = os.fsencode(userhome)
 
-    return userhome + path[i:]
+    return os.path.normpath(userhome) + path[i:]
 
 
 # Expand paths containing shell variable substitutions.
@@ -496,14 +510,12 @@ def expandvars(path):
     def normpath(path):
         """Normalize path, eliminating double slashes, etc."""
         path = os.fspath(path)
+        sep = _get_sep(path)
+        altsep = _get_altsep(path)
         if isinstance(path, bytes):
-            sep = b'\\'
-            altsep = b'/'
             curdir = b'.'
             pardir = b'..'
         else:
-            sep = '\\'
-            altsep = '/'
             curdir = '.'
             pardir = '..'
         path = path.replace(altsep, sep)
@@ -570,7 +582,7 @@ def _abspath_fallback(path):
     def abspath(path):
         """Return the absolute version of a path."""
         try:
-            return _getfullpathname(normpath(path))
+            return normpath(_getfullpathname(normpath(path)))
         except (OSError, ValueError):
             return _abspath_fallback(path)
 
@@ -719,6 +731,7 @@ def realpath(path, *, strict=False):
                 # strip the prefix anyway.
                 if ex.winerror == initial_winerror:
                     path = spath
+        path = normpath(path)
         return path
 
 
@@ -729,12 +742,11 @@ def realpath(path, *, strict=False):
 def relpath(path, start=None):
     """Return a relative version of a path"""
     path = os.fspath(path)
+    sep = _get_sep(path)
     if isinstance(path, bytes):
-        sep = b'\\'
         curdir = b'.'
         pardir = b'..'
     else:
-        sep = '\\'
         curdir = '.'
         pardir = '..'
 
@@ -789,13 +801,11 @@ def commonpath(paths):
         raise ValueError('commonpath() arg is an empty sequence')
 
     paths = tuple(map(os.fspath, paths))
+    sep = _get_sep(paths[0])
+    altsep = _get_altsep(paths[0])
     if isinstance(paths[0], bytes):
-        sep = b'\\'
-        altsep = b'/'
         curdir = b'.'
     else:
-        sep = '\\'
-        altsep = '/'
         curdir = '.'
 
     try:
diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index ecb1e8a..eec8a9e 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -115,6 +115,8 @@ class _WindowsFlavour(_Flavour):
 
     sep = '\\'
     altsep = '/'
+    if os.environ.get('MSYSTEM', ''):
+        sep, altsep = altsep, sep
     has_drv = True
     pathmod = ntpath
 
diff --git a/Lib/site.py b/Lib/site.py
index 69670d9..41b9cf1 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -88,6 +88,12 @@
 USER_BASE = None
 
 
+# Same as defined in Lib/sysconfig.py
+# redeclared since sysconfig is large for site.
+# GCC[mingw*] use posix build system
+_POSIX_BUILD = os.name == 'posix' or \
+    (os.name == "nt" and 'GCC' in sys.version)
+
 def _trace(message):
     if sys.flags.verbose:
         print(message, file=sys.stderr)
@@ -273,7 +279,7 @@ def _getuserbase():
     def joinuser(*args):
         return os.path.expanduser(os.path.join(*args))
 
-    if os.name == "nt":
+    if os.name == "nt" and not _POSIX_BUILD:
         base = os.environ.get("APPDATA") or "~"
         return joinuser(base, "Python")
 
@@ -283,14 +289,36 @@ def joinuser(*args):
 
     return joinuser("~", ".local")
 
+# Copy of sysconfig.get_platform() but only for MinGW
+def _get_platform():
+    if os.name == 'nt':
+        if 'gcc' in sys.version.lower():
+            if 'ucrt' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_ucrt'
+                return 'mingw_i686_ucrt'
+            if 'clang' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_clang'
+                if 'arm64' in sys.version.lower():
+                    return 'mingw_aarch64'
+                if 'arm' in sys.version.lower():
+                    return 'mingw_armv7'
+                return 'mingw_i686_clang'
+            if 'amd64' in sys.version.lower():
+                return 'mingw_x86_64'
+            return 'mingw_i686'
+    return sys.platform
 
 # Same to sysconfig.get_path('purelib', os.name+'_user')
 def _get_path(userbase):
     version = sys.version_info
 
     if os.name == 'nt':
-        ver_nodot = sys.winver.replace('.', '')
-        return f'{userbase}\\Python{ver_nodot}\\site-packages'
+        if not _POSIX_BUILD:
+            ver_nodot = sys.winver.replace('.', '')
+            return f'{userbase}\\Python{ver_nodot}\\site-packages'
+        return f'{userbase}/lib/python{version[0]}.{version[1]}-{_get_platform()}/site-packages'
 
     if sys.platform == 'darwin' and sys._framework:
         return f'{userbase}/lib/python/site-packages'
@@ -361,7 +389,7 @@ def getsitepackages(prefixes=None):
             continue
         seen.add(prefix)
 
-        if os.sep == '/':
+        if _POSIX_BUILD:
             libdirs = [sys.platlibdir]
             if sys.platlibdir != "lib":
                 libdirs.append("lib")
@@ -392,7 +420,7 @@ def setquit():
     The repr of each object contains a hint at how it works.
 
     """
-    if os.sep == '\\':
+    if sys.platform == 'win32':
         eof = 'Ctrl-Z plus Return'
     else:
         eof = 'Ctrl-D (i.e. EOF)'
diff --git a/Lib/ssl.py b/Lib/ssl.py
index ebac1d6..cac0c37 100644
--- a/Lib/ssl.py
+++ b/Lib/ssl.py
@@ -254,7 +254,7 @@ class _TLSMessageType:
     CHANGE_CIPHER_SPEC = 0x0101
 
 
-if sys.platform == "win32":
+if sys.platform == "win32" and sys.version.find("GCC") == -1:
     from _ssl import enum_certificates, enum_crls
 
 from socket import socket, SOCK_STREAM, create_connection
@@ -591,7 +591,7 @@ def _load_windows_store_certs(self, storename, purpose):
     def load_default_certs(self, purpose=Purpose.SERVER_AUTH):
         if not isinstance(purpose, _ASN1Object):
             raise TypeError(purpose)
-        if sys.platform == "win32":
+        if sys.platform == "win32" and sys.version.find("GCC") == -1:
             for storename in self._windows_cert_stores:
                 self._load_windows_store_certs(storename, purpose)
         self.set_default_verify_paths()
diff --git a/Lib/sysconfig.py b/Lib/sysconfig.py
index ebe3711..8035d2e 100644
--- a/Lib/sysconfig.py
+++ b/Lib/sysconfig.py
@@ -2,6 +2,7 @@
 
 import os
 import sys
+import textwrap
 from os.path import pardir, realpath
 
 __all__ = [
@@ -47,13 +48,13 @@
         'data': '{base}',
         },
     'nt': {
-        'stdlib': '{installed_base}/Lib',
-        'platstdlib': '{base}/Lib',
-        'purelib': '{base}/Lib/site-packages',
-        'platlib': '{base}/Lib/site-packages',
-        'include': '{installed_base}/Include',
-        'platinclude': '{installed_base}/Include',
-        'scripts': '{base}/Scripts',
+        'stdlib': '{installed_base}/lib/python{py_version_short}',
+        'platstdlib': '{base}/lib/python{py_version_short}',
+        'purelib': '{base}/lib/python{py_version_short}/site-packages',
+        'platlib': '{base}/lib/python{py_version_short}/site-packages',
+        'include': '{installed_base}/include/python{py_version_short}',
+        'platinclude': '{installed_base}/include/python{py_version_short}',
+        'scripts': '{base}/bin',
         'data': '{base}',
         },
     # Downstream distributors can overwrite the default install scheme.
@@ -97,13 +98,18 @@
         },
     }
 
+# GCC[mingw*] use posix build system
+_POSIX_BUILD = os.name == 'posix' or \
+    (os.name == "nt" and 'GCC' in sys.version)
+
 # For the OS-native venv scheme, we essentially provide an alias:
-if os.name == 'nt':
+if os.name == 'nt' and not _POSIX_BUILD:
     _INSTALL_SCHEMES['venv'] = _INSTALL_SCHEMES['nt_venv']
 else:
     _INSTALL_SCHEMES['venv'] = _INSTALL_SCHEMES['posix_venv']
 
 
+
 # NOTE: site.py has copy of this function.
 # Sync it when modify this function.
 def _getuserbase():
@@ -118,7 +124,7 @@ def _getuserbase():
     def joinuser(*args):
         return os.path.expanduser(os.path.join(*args))
 
-    if os.name == "nt":
+    if os.name == "nt" and not _POSIX_BUILD:
         base = os.environ.get("APPDATA") or "~"
         return joinuser(base, "Python")
 
@@ -134,20 +140,20 @@ def joinuser(*args):
     _INSTALL_SCHEMES |= {
         # NOTE: When modifying "purelib" scheme, update site._get_path() too.
         'nt_user': {
-            'stdlib': '{userbase}/Python{py_version_nodot_plat}',
-            'platstdlib': '{userbase}/Python{py_version_nodot_plat}',
-            'purelib': '{userbase}/Python{py_version_nodot_plat}/site-packages',
-            'platlib': '{userbase}/Python{py_version_nodot_plat}/site-packages',
-            'include': '{userbase}/Python{py_version_nodot_plat}/Include',
-            'scripts': '{userbase}/Python{py_version_nodot_plat}/Scripts',
+            'stdlib': '{userbase}/lib/python{py_version_short_plat}',
+            'platstdlib': '{userbase}/lib/python{py_version_short_plat}',
+            'purelib': '{userbase}/lib/python{py_version_short_plat}/site-packages',
+            'platlib': '{userbase}/lib/python{py_version_short_plat}/site-packages',
+            'include': '{userbase}/include/python{py_version_short_plat}',
+            'scripts': '{userbase}/bin',
             'data': '{userbase}',
             },
         'posix_user': {
-            'stdlib': '{userbase}/{platlibdir}/python{py_version_short}',
-            'platstdlib': '{userbase}/{platlibdir}/python{py_version_short}',
-            'purelib': '{userbase}/lib/python{py_version_short}/site-packages',
-            'platlib': '{userbase}/lib/python{py_version_short}/site-packages',
-            'include': '{userbase}/include/python{py_version_short}',
+            'stdlib': '{userbase}/{platlibdir}/python{py_version_short_plat}',
+            'platstdlib': '{userbase}/{platlibdir}/python{py_version_short_plat}',
+            'purelib': '{userbase}/lib/python{py_version_short_plat}/site-packages',
+            'platlib': '{userbase}/lib/python{py_version_short_plat}/site-packages',
+            'include': '{userbase}/include/python{py_version_short_plat}',
             'scripts': '{userbase}/bin',
             'data': '{userbase}',
             },
@@ -277,7 +283,7 @@ def _expand_vars(scheme, vars):
 
 
 def _get_preferred_schemes():
-    if os.name == 'nt':
+    if os.name == 'nt' and not _POSIX_BUILD:
         return {
             'prefix': 'nt',
             'home': 'posix_home',
@@ -435,6 +441,14 @@ def _parse_makefile(filename, vars=None, keep_unresolved=True):
         if isinstance(v, str):
             done[k] = v.strip()
 
+    # any keys that have one with the same name suffixed with _b2h
+    # need to be replaced with the value of the _b2h key.
+    # This converts from MSYS*/Cygwin paths to Windows paths.
+    for k, v in dict(done).items():
+        if isinstance(k, str):
+            if k.endswith("_b2h"):
+                done[k[:-4]]=v
+ 
     # save the results in the global dictionary
     vars.update(done)
     return vars
@@ -514,11 +528,30 @@ def _generate_posix_vars():
     os.makedirs(pybuilddir, exist_ok=True)
     destfile = os.path.join(pybuilddir, name + '.py')
 
+    replacement = """
+        keys_to_replace = [
+            'BINDIR', 'BINLIBDEST', 'CONFINCLUDEDIR',
+            'CONFINCLUDEPY', 'DESTDIRS', 'DESTLIB', 'DESTSHARED',
+            'INCLDIRSTOMAKE', 'INCLUDEDIR', 'INCLUDEPY',
+            'LIBDEST', 'LIBDIR', 'LIBPC', 'LIBPL', 'MACHDESTLIB',
+            'MANDIR', 'SCRIPTDIR', 'datarootdir', 'exec_prefix',
+            'TZPATH',
+        ]
+
+        prefix = build_time_vars['BINDIR'][:-4]
+
+        for key in keys_to_replace:
+            value = build_time_vars[key]
+            build_time_vars[key] = value.replace(prefix, sys.prefix)
+    """
+
     with open(destfile, 'w', encoding='utf8') as f:
+        f.write('import sys\n')
         f.write('# system configuration generated and used by'
                 ' the sysconfig module\n')
         f.write('build_time_vars = ')
         pprint.pprint(vars, stream=f)
+        f.write('\n%s' % textwrap.dedent(replacement))
 
     # Create file used for sys.path fixup -- see Modules/getpath.c
     with open('pybuilddir.txt', 'w', encoding='utf8') as f:
@@ -541,7 +574,7 @@ def _init_non_posix(vars):
     vars['INCLUDEPY'] = get_path('include')
     vars['EXT_SUFFIX'] = _imp.extension_suffixes()[0]
     vars['EXE'] = '.exe'
-    vars['VERSION'] = _PY_VERSION_SHORT_NO_DOT
+    vars['VERSION'] = _PY_VERSION_SHORT
     vars['BINDIR'] = os.path.dirname(_safe_realpath(sys.executable))
     vars['TZPATH'] = ''
 
@@ -587,7 +620,7 @@ def parse_config_h(fp, vars=None):
 def get_config_h_filename():
     """Return the path of pyconfig.h."""
     if _PYTHON_BUILD:
-        if os.name == "nt":
+        if os.name == "nt" and not _POSIX_BUILD:
             inc_dir = os.path.join(_PROJECT_BASE, "PC")
         else:
             inc_dir = _PROJECT_BASE
@@ -662,11 +695,15 @@ def get_config_vars(*args):
             _CONFIG_VARS['py_version_nodot_plat'] = sys.winver.replace('.', '')
         except AttributeError:
             _CONFIG_VARS['py_version_nodot_plat'] = ''
+        if os.name == 'nt' and _POSIX_BUILD:
+            _CONFIG_VARS['py_version_short_plat'] = f'{_PY_VERSION_SHORT}-{get_platform()}'
+        else:
+            _CONFIG_VARS['py_version_short_plat'] = _PY_VERSION_SHORT
 
-        if os.name == 'nt':
+        if os.name == 'nt' and not _POSIX_BUILD:
             _init_non_posix(_CONFIG_VARS)
             _CONFIG_VARS['VPATH'] = sys._vpath
-        if os.name == 'posix':
+        if _POSIX_BUILD:
             _init_posix(_CONFIG_VARS)
         if _HAS_USER_BASE:
             # Setting 'userbase' is done below the call to the
@@ -676,7 +713,7 @@ def get_config_vars(*args):
 
         # Always convert srcdir to an absolute path
         srcdir = _CONFIG_VARS.get('srcdir', _PROJECT_BASE)
-        if os.name == 'posix':
+        if _POSIX_BUILD:
             if _PYTHON_BUILD:
                 # If srcdir is a relative path (typically '.' or '..')
                 # then it should be interpreted relative to the directory
@@ -714,7 +751,7 @@ def get_config_var(name):
     """
     return get_config_vars().get(name)
 
-
+# make sure to change site._get_platform() while changing this function
 def get_platform():
     """Return a string that identifies the current platform.
 
@@ -737,6 +774,22 @@ def get_platform():
 
     """
     if os.name == 'nt':
+        if 'gcc' in sys.version.lower():
+            if 'ucrt' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_ucrt'
+                return 'mingw_i686_ucrt'
+            if 'clang' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_clang'
+                if 'arm64' in sys.version.lower():
+                    return 'mingw_aarch64'
+                if 'arm' in sys.version.lower():
+                    return 'mingw_armv7'
+                return 'mingw_i686_clang'
+            if 'amd64' in sys.version.lower():
+                return 'mingw_x86_64'
+            return 'mingw_i686'
         if 'amd64' in sys.version.lower():
             return 'win-amd64'
         if '(arm)' in sys.version.lower():
diff --git a/Lib/test/__main__.py b/Lib/test/__main__.py
index 19a6b2b..7641b32 100644
--- a/Lib/test/__main__.py
+++ b/Lib/test/__main__.py
@@ -1,2 +1,10 @@
+import os
+import sys
+
 from test.libregrtest import main
+
+if sys.platform == "win32":
+    # Enable DLL loading from PATH.
+    os.environ["PYTHONLEGACYWINDOWSDLLLOADING"] = "1"
+
 main()
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 53ba1ad..3b6f4ab 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -1105,7 +1105,7 @@ def test_from_format(self):
 
         if os.name == 'nt':
             # Windows (MSCRT)
-            ptr_format = '0x%0{}X'.format(2 * sizeof_ptr)
+            ptr_format = '0x%0{}x'.format(2 * sizeof_ptr)
             def ptr_formatter(ptr):
                 return (ptr_format % ptr)
         else:
diff --git a/Lib/test/test_getpath.py b/Lib/test/test_getpath.py
index 8d5b426..82ad71d 100644
--- a/Lib/test/test_getpath.py
+++ b/Lib/test/test_getpath.py
@@ -838,6 +838,7 @@ def test_symlink_buildpath_macos(self):
     ENV_PYTHONHOME="",
     ENV_PYTHONEXECUTABLE="",
     ENV___PYVENV_LAUNCHER__="",
+    ENV_MSYSTEM="",
     argv0="",
     py_setpath="",
     real_executable="",
@@ -877,6 +878,7 @@ def __init__(self, *a, argv0=None, config=None, **kw):
         self.update(DEFAULT_NAMESPACE)
         self["config"] = DEFAULT_CONFIG.copy()
         self["os_name"] = "nt"
+        self["is_mingw"] = 0
         self["PLATLIBDIR"] = "DLLs"
         self["PYWINVER"] = "9.8-XY"
         self["VPATH"] = r"..\.."
@@ -912,6 +914,9 @@ def __missing__(self, key):
         except AttributeError:
             raise KeyError(key) from None
 
+    def normpath(self, path):
+        return ntpath.normpath(path)
+
     def abspath(self, path):
         if self.isabs(path):
             return path
@@ -1053,6 +1058,7 @@ def __init__(self, *a, argv0=None, config=None, **kw):
         self.update(DEFAULT_NAMESPACE)
         self["config"] = DEFAULT_CONFIG.copy()
         self["os_name"] = "posix"
+        self["is_mingw"] = 0
         self["PLATLIBDIR"] = "lib"
         self["WITH_NEXT_FRAMEWORK"] = 0
         super().__init__(*a, **kw)
@@ -1089,6 +1095,9 @@ def __missing__(self, key):
         except AttributeError:
             raise KeyError(key) from None
 
+    def normpath(self, path):
+        return path
+
     def abspath(self, path):
         if self.isabs(path):
             return path
diff --git a/Lib/test/test_httpservers.py b/Lib/test/test_httpservers.py
index cdd1bea..cfd8a10 100644
--- a/Lib/test/test_httpservers.py
+++ b/Lib/test/test_httpservers.py
@@ -442,10 +442,10 @@ def test_undecodable_filename(self):
     def test_undecodable_parameter(self):
         # sanity check using a valid parameter
         response = self.request(self.base_url + '/?x=123').read()
-        self.assertRegex(response, f'listing for {self.base_url}/\?x=123'.encode('latin1'))
+        self.assertRegex(response, rf'listing for {self.base_url}/\?x=123'.encode('latin1'))
         # now the bogus encoding
         response = self.request(self.base_url + '/?x=%bb').read()
-        self.assertRegex(response, f'listing for {self.base_url}/\?x=\xef\xbf\xbd'.encode('latin1'))
+        self.assertRegex(response, rf'listing for {self.base_url}/\?x=\xef\xbf\xbd'.encode('latin1'))
 
     def test_get_dir_redirect_location_domain_injection_bug(self):
         """Ensure //evil.co/..%2f../../X does not put //evil.co/ in Location.
diff --git a/Lib/test/test_importlib/test_windows.py b/Lib/test/test_importlib/test_windows.py
index b7dfe86..58a8f5d 100644
--- a/Lib/test/test_importlib/test_windows.py
+++ b/Lib/test/test_importlib/test_windows.py
@@ -24,6 +24,23 @@ def get_platform():
             'x64' : 'win-amd64',
             'arm' : 'win-arm32',
         }
+    if os.name == 'nt':
+        if 'gcc' in sys.version.lower():
+            if 'ucrt' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_ucrt'
+                return 'mingw_i686_ucrt'
+            if 'clang' in sys.version.lower():
+                if 'amd64' in sys.version.lower():
+                    return 'mingw_x86_64_clang'
+                if 'arm64' in sys.version.lower():
+                    return 'mingw_aarch64'
+                if 'arm' in sys.version.lower():
+                    return 'mingw_armv7'
+                return 'mingw_i686_clang'
+            if 'amd64' in sys.version.lower():
+                return 'mingw_x86_64'
+            return 'mingw_i686'
     if ('VSCMD_ARG_TGT_ARCH' in os.environ and
         os.environ['VSCMD_ARG_TGT_ARCH'] in TARGET_TO_PLAT):
         return TARGET_TO_PLAT[os.environ['VSCMD_ARG_TGT_ARCH']]
diff --git a/Lib/test/test_sysconfig.py b/Lib/test/test_sysconfig.py
index d96371d..a75a664 100644
--- a/Lib/test/test_sysconfig.py
+++ b/Lib/test/test_sysconfig.py
@@ -17,7 +17,7 @@
 from sysconfig import (get_paths, get_platform, get_config_vars,
                        get_path, get_path_names, _INSTALL_SCHEMES,
                        get_default_scheme, get_scheme_names, get_config_var,
-                       _expand_vars, _get_preferred_schemes, _main)
+                       _expand_vars, _get_preferred_schemes, _main, _POSIX_BUILD)
 import _osx_support
 
 
@@ -180,7 +180,7 @@ def test_nt_venv_scheme(self):
         self.assertEqual(libpath, sysconfig.get_path('purelib', scheme='nt_venv'))
 
     def test_venv_scheme(self):
-        if sys.platform == 'win32':
+        if not _POSIX_BUILD and sys.platform == 'win32':
             self.assertEqual(
                 sysconfig.get_path('scripts', scheme='venv'),
                 sysconfig.get_path('scripts', scheme='nt_venv')
@@ -371,6 +371,10 @@ def test_user_similar(self):
             if HAS_USER_BASE:
                 user_path = get_path(name, 'posix_user')
                 expected = os.path.normpath(global_path.replace(base, user, 1))
+                if os.name == 'nt' and _POSIX_BUILD:
+                    expected = expected.replace(
+                        f'python{sysconfig.get_python_version()}',
+                        f'python{sysconfig.get_python_version()}-{get_platform()}')
                 # bpo-44860: platlib of posix_user doesn't use sys.platlibdir,
                 # whereas posix_prefix does.
                 if name == 'platlib':
diff --git a/Lib/venv/__init__.py b/Lib/venv/__init__.py
index 6bce308..1cd57d0 100644
--- a/Lib/venv/__init__.py
+++ b/Lib/venv/__init__.py
@@ -11,7 +11,7 @@
 import sys
 import sysconfig
 import types
-
+from sysconfig import _POSIX_BUILD
 
 CORE_VENV_DEPS = ('pip', 'setuptools')
 logger = logging.getLogger(__name__)
@@ -301,7 +301,7 @@ def setup_python(self, context):
                     if not os.path.islink(path):
                         os.chmod(path, 0o755)
         else:
-            if self.symlinks:
+            if self.symlinks and not _POSIX_BUILD:
                 # For symlinking, we need a complete copy of the root directory
                 # If symlinks fail, you'll get unnecessary copies of files, but
                 # we assume that if you've opted into symlinks on Windows then
@@ -325,6 +325,12 @@ def setup_python(self, context):
                 if os.path.lexists(src):
                     copier(src, os.path.join(binpath, suffix))
 
+            if _POSIX_BUILD:
+                # copy from python/pythonw so the venvlauncher magic in symlink_or_copy triggers
+                copier(os.path.join(dirname, 'python.exe'), os.path.join(binpath, 'python3.exe'))
+                copier(os.path.join(dirname, 'python.exe'), os.path.join(binpath, 'python%d.%d.exe' % sys.version_info[:2]))
+                copier(os.path.join(dirname, 'pythonw.exe'), os.path.join(binpath, 'python3w.exe'))
+
             if sysconfig.is_python_build():
                 # copy init.tcl
                 for root, dirs, files in os.walk(context.python_dir):
@@ -349,6 +355,7 @@ def _call_new_python(self, context, *py_args, **kwargs):
         env['VIRTUAL_ENV'] = context.env_dir
         env.pop('PYTHONHOME', None)
         env.pop('PYTHONPATH', None)
+        env.pop("MSYSTEM", None)
         kwargs['cwd'] = context.env_dir
         kwargs['executable'] = context.env_exec_cmd
         subprocess.check_output(args, **kwargs)
diff --git a/Lib/venv/scripts/common/activate b/Lib/venv/scripts/common/activate
index 6fbc2b8..9c3d58d 100644
--- a/Lib/venv/scripts/common/activate
+++ b/Lib/venv/scripts/common/activate
@@ -38,7 +38,7 @@ deactivate () {
 # unset irrelevant variables
 deactivate nondestructive
 
-VIRTUAL_ENV="__VENV_DIR__"
+VIRTUAL_ENV=$(cygpath "__VENV_DIR__")
 export VIRTUAL_ENV
 
 _OLD_VIRTUAL_PATH="$PATH"
diff --git a/Makefile.pre.in b/Makefile.pre.in
index 3ea8653..2707d04 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -39,6 +39,7 @@ CXX=		@CXX@
 MAINCC=		@MAINCC@
 LINKCC=		@LINKCC@
 AR=		@AR@
+WINDRES=	@WINDRES@
 READELF=	@READELF@
 SOABI=		@SOABI@
 LDVERSION=	@LDVERSION@
@@ -123,6 +124,7 @@ PY_CORE_CFLAGS=	$(PY_STDMODULE_CFLAGS) -DPy_BUILD_CORE
 PY_CORE_LDFLAGS=$(PY_LDFLAGS) $(PY_LDFLAGS_NODIST)
 # Strict or non-strict aliasing flags used to compile dtoa.c, see above
 CFLAGS_ALIASING=@CFLAGS_ALIASING@
+RCFLAGS=@RCFLAGS@
 
 
 # Machine-dependent subdirectories
@@ -141,6 +143,12 @@ exec_prefix=	@exec_prefix@
 # Install prefix for data files
 datarootdir=    @datarootdir@
 
+# Locations needed for semi-native fixup of sysconfig.
+srcdir_b2h=		@srcdir_b2h@
+abs_srcdir_b2h=		@abs_srcdir_b2h@
+abs_builddir_b2h=	@abs_builddir_b2h@
+prefix_b2h=		@prefix_b2h@
+
 # Expanded directories
 BINDIR=		@bindir@
 LIBDIR=		@libdir@
@@ -158,10 +166,12 @@ BINLIBDEST=	@BINLIBDEST@
 LIBDEST=	$(SCRIPTDIR)/python$(VERSION)
 INCLUDEPY=	$(INCLUDEDIR)/python$(LDVERSION)
 CONFINCLUDEPY=	$(CONFINCLUDEDIR)/python$(LDVERSION)
+VENVLAUNCHERDIR=	$(BINLIBDEST)/venv/scripts/nt
 
 # Symbols used for using shared libraries
 SHLIB_SUFFIX=	@SHLIB_SUFFIX@
 EXT_SUFFIX=	@EXT_SUFFIX@
+PYD_PLATFORM_TAG = @PYD_PLATFORM_TAG@
 LDSHARED=	@LDSHARED@ $(PY_LDFLAGS)
 BLDSHARED=	@BLDSHARED@ $(PY_CORE_LDFLAGS)
 LDCXXSHARED=	@LDCXXSHARED@
@@ -268,6 +278,8 @@ LIBRARY_DEPS=	@LIBRARY_DEPS@
 LINK_PYTHON_DEPS=@LINK_PYTHON_DEPS@
 PY_ENABLE_SHARED=	@PY_ENABLE_SHARED@
 STATIC_LIBPYTHON=	@STATIC_LIBPYTHON@
+ABI3DLLLIBRARY= libpython3.dll
+ABI3LDLIBRARY=  libpython3.dll.a
 
 
 LIBS=		@LIBS@
@@ -284,6 +296,7 @@ LIBOBJS=	@LIBOBJS@
 
 PYTHON=		python$(EXE)
 BUILDPYTHON=	python$(BUILDEXE)
+BUILDPYTHONW=	pythonw$(BUILDEXE)
 
 HOSTRUNNER= @HOSTRUNNER@
 
@@ -344,6 +357,7 @@ IO_OBJS=	\
 ##########################################################################
 
 LIBFFI_INCLUDEDIR=	@LIBFFI_INCLUDEDIR@
+NCURSESW_INCLUDEDIR=	@NCURSESW_INCLUDEDIR@
 
 ##########################################################################
 # Parser
@@ -390,7 +404,7 @@ PYTHON_OBJS=	\
 		Python/dynamic_annotations.o \
 		Python/errors.o \
 		Python/frame.o \
-		Python/frozenmain.o \
+		@PYTHON_OBJS_FROZENMAIN@ \
 		Python/future.o \
 		Python/getargs.o \
 		Python/getcompiler.o \
@@ -402,6 +416,7 @@ PYTHON_OBJS=	\
 		Python/import.o \
 		Python/importdl.o \
 		Python/initconfig.o \
+		Python/iscygpty.o \
 		Python/marshal.o \
 		Python/modsupport.o \
 		Python/mysnprintf.o \
@@ -584,8 +599,8 @@ LIBEXPAT_HEADERS= \
 
 # Default target
 all:		@DEF_MAKE_ALL_RULE@
-build_all:	check-clean-src $(BUILDPYTHON) platform oldsharedmods sharedmods \
-		gdbhooks Programs/_testembed python-config
+build_all:	check-clean-src $(BUILDPYTHON) $(BUILDPYTHONW) platform oldsharedmods sharedmods \
+		gdbhooks Programs/_testembed python-config $(ABI3DLLLIBRARY) $(ABI3LDLIBRARY)
 build_wasm: check-clean-src $(BUILDPYTHON) platform oldsharedmods python-config
 
 # Check that the source is clean when building out of source.
@@ -700,9 +715,30 @@ coverage-report: regen-token regen-frozen
 clinic: check-clean-src $(srcdir)/Modules/_blake2/blake2s_impl.c
 	$(PYTHON_FOR_REGEN) $(srcdir)/Tools/clinic/clinic.py --make --srcdir $(srcdir)
 
+python_exe.o: $(srcdir)/PC/python_exe.rc
+	$(WINDRES) $(RCFLAGS) -I$(srcdir)/Include -I$(srcdir)/PC -I. $(srcdir)/PC/python_exe.rc $@
+
+pythonw_exe.o: $(srcdir)/PC/pythonw_exe.rc
+	$(WINDRES) $(RCFLAGS) -I$(srcdir)/Include -I$(srcdir)/PC -I. $(srcdir)/PC/pythonw_exe.rc $@
+
+python_nt.o: $(srcdir)/PC/python_nt.rc
+	$(WINDRES) $(RCFLAGS) -DORIGINAL_FILENAME=\\\"$(DLLLIBRARY)\\\" -I$(srcdir)/Include -I$(srcdir)/PC -I. $(srcdir)/PC/python_nt.rc $@
+
+python3dll_nt.o: $(srcdir)/PC/python_nt.rc
+	$(WINDRES) $(RCFLAGS) -DORIGINAL_FILENAME=\\\"$(ABI3DLLLIBRARY)\\\" -I$(srcdir)/Include -I$(srcdir)/PC -I. $(srcdir)/PC/python_nt.rc $@
+
+venvlauncher.o: $(srcdir)/PC/pylauncher.rc
+	$(WINDRES) $(RCFLAGS) -DPY_ICON -I$(srcdir)/Include -I$(srcdir)/PC -I. $(srcdir)/PC/pylauncher.rc $@
+
+venvwlauncher.o: $(srcdir)/PC/pylauncher.rc
+	$(WINDRES) $(RCFLAGS) -DPYW_ICON -I$(srcdir)/Include -I$(srcdir)/PC -I. $(srcdir)/PC/pylauncher.rc $@
+
+$(BUILDPYTHONW): Programs/python.o $(LIBRARY) $(LDLIBRARY) $(PY3LIBRARY) pythonw_exe.o
+	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -municode -mwindows -o $@ Programs/python.o $(BLDLIBRARY) $(LIBS) $(MODLIBS) $(SYSLIBS) pythonw_exe.o
+
 # Build the interpreter
-$(BUILDPYTHON):	Programs/python.o $(LINK_PYTHON_DEPS)
-	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -o $@ Programs/python.o $(LINK_PYTHON_OBJS) $(LIBS) $(MODLIBS) $(SYSLIBS)
+$(BUILDPYTHON):	Programs/python.o $(LINK_PYTHON_DEPS) python_exe.o
+	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -municode -o $@ Programs/python.o $(LINK_PYTHON_OBJS) $(LIBS) $(MODLIBS) $(SYSLIBS) python_exe.o
 
 platform: $(PYTHON_FOR_BUILD_DEPS) pybuilddir.txt
 	$(RUNSHARED) $(PYTHON_FOR_BUILD) -c 'import sys ; from sysconfig import get_platform ; print("%s-%d.%d" % (get_platform(), *sys.version_info[:2]))' >platform
@@ -806,13 +842,17 @@ $(PYTHONFRAMEWORKDIR)/Versions/$(VERSION)/$(PYTHONFRAMEWORK): \
 
 # This rule builds the Cygwin Python DLL and import library if configured
 # for a shared core library; otherwise, this rule is a noop.
-$(DLLLIBRARY) libpython$(LDVERSION).dll.a: $(LIBRARY_OBJS)
+$(DLLLIBRARY) libpython$(LDVERSION).dll.a: $(LIBRARY_OBJS) python_nt.o
 	if test -n "$(DLLLIBRARY)"; then \
 		$(LDSHARED) -Wl,--out-implib=$@ -o $(DLLLIBRARY) $^ \
-			$(LIBS) $(MODLIBS) $(SYSLIBS); \
+			$(LIBS) $(LDFLAGS_NODIST) $(MODLIBS) $(SYSLIBS) python_nt.o; \
 	else true; \
 	fi
 
+$(ABI3DLLLIBRARY) $(ABI3LDLIBRARY): python3dll_nt.o $(srcdir)/PC/launcher.c
+	$(LDSHARED) -DPYTHON_DLL_NAME=\"$(DLLLIBRARY)\" $(srcdir)/PC/python3dll.c -Wl,--out-implib=$(ABI3LDLIBRARY) -o $(ABI3DLLLIBRARY) python3dll_nt.o \
+		$(LDFLAGS_NODIST);
+
 # wasm32-emscripten browser build
 # wasm assets directory is relative to current build dir, e.g. "./usr/local".
 # --preload-file turns a relative asset path into an absolute path.
@@ -974,7 +1014,7 @@ BOOTSTRAP_HEADERS = \
 Programs/_bootstrap_python.o: Programs/_bootstrap_python.c $(BOOTSTRAP_HEADERS) $(PYTHON_HEADERS)
 
 _bootstrap_python: $(LIBRARY_OBJS_OMIT_FROZEN) Programs/_bootstrap_python.o Modules/getpath.o Modules/Setup.local
-	$(LINKCC) $(PY_LDFLAGS_NOLTO) -o $@ $(LIBRARY_OBJS_OMIT_FROZEN) \
+	$(LINKCC) $(PY_LDFLAGS_NOLTO) -o $@ -municode -mwindows $(LIBRARY_OBJS_OMIT_FROZEN) \
 		Programs/_bootstrap_python.o Modules/getpath.o $(LIBS) $(MODLIBS) $(SYSLIBS)
 
 
@@ -1276,9 +1316,15 @@ Python/dynload_hpux.o: $(srcdir)/Python/dynload_hpux.c Makefile
 		-DSHLIB_EXT='"$(EXT_SUFFIX)"' \
 		-o $@ $(srcdir)/Python/dynload_hpux.c
 
+Python/dynload_win.o: $(srcdir)/Python/dynload_win.c Makefile
+	$(CC) -c $(PY_CORE_CFLAGS) \
+		-DPYD_PLATFORM_TAG='"$(PYD_PLATFORM_TAG)"' \
+		-o $@ $(srcdir)/Python/dynload_win.c
+
 Python/sysmodule.o: $(srcdir)/Python/sysmodule.c Makefile $(srcdir)/Include/pydtrace.h
 	$(CC) -c $(PY_CORE_CFLAGS) \
 		-DABIFLAGS='"$(ABIFLAGS)"' \
+		-DVPATH='"$(VPATH)"' \
 		$(MULTIARCH_CPPFLAGS) \
 		-o $@ $(srcdir)/Python/sysmodule.c
 
@@ -1496,6 +1542,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/frameobject.h \
 		$(srcdir)/Include/import.h \
 		$(srcdir)/Include/intrcheck.h \
+		$(srcdir)/Include/iscygpty.h \
 		$(srcdir)/Include/iterobject.h \
 		$(srcdir)/Include/listobject.h \
 		$(srcdir)/Include/longobject.h \
@@ -1791,7 +1838,7 @@ $(DESTSHARED):
 # Install the interpreter with $(VERSION) affixed
 # This goes into $(exec_prefix)
 altbininstall: $(BUILDPYTHON) @FRAMEWORKPYTHONW@
-	@for i in $(BINDIR) $(LIBDIR); \
+	@for i in $(BINDIR) $(LIBDIR) $(VENVLAUNCHERDIR); \
 	do \
 		if test ! -d $(DESTDIR)$$i; then \
 			echo "Creating directory $$i"; \
@@ -1801,6 +1848,7 @@ altbininstall: $(BUILDPYTHON) @FRAMEWORKPYTHONW@
 	done
 	if test "$(PYTHONFRAMEWORKDIR)" = "no-framework" ; then \
 		$(INSTALL_PROGRAM) $(BUILDPYTHON) $(DESTDIR)$(BINDIR)/python$(LDVERSION)$(EXE); \
+		$(INSTALL_PROGRAM) $(BUILDPYTHONW) $(DESTDIR)$(BINDIR)/python3w$(EXE); \
 	else \
 		$(INSTALL_PROGRAM) $(STRIPFLAG) Mac/pythonw $(DESTDIR)$(BINDIR)/python$(LDVERSION)$(EXE); \
 	fi
@@ -1814,6 +1862,7 @@ altbininstall: $(BUILDPYTHON) @FRAMEWORKPYTHONW@
 		if test -f $(LDLIBRARY) && test "$(PYTHONFRAMEWORKDIR)" = "no-framework" ; then \
 			if test -n "$(DLLLIBRARY)" ; then \
 				$(INSTALL_SHARED) $(DLLLIBRARY) $(DESTDIR)$(BINDIR); \
+				$(INSTALL_SHARED) $(ABI3DLLLIBRARY) $(DESTDIR)$(BINDIR); \
 			else \
 				$(INSTALL_SHARED) $(LDLIBRARY) $(DESTDIR)$(LIBDIR)/$(INSTSONAME); \
 				if test $(LDLIBRARY) != $(INSTSONAME); then \
@@ -1924,6 +1973,7 @@ LIBSUBDIRS=	asyncio \
 		tkinter \
 		tomllib \
 		turtledemo \
+		msilib \
 		unittest \
 		urllib \
 		venv venv/scripts venv/scripts/common venv/scripts/posix \
@@ -2223,8 +2273,9 @@ libainstall: all python-config
 	@if test "$(STATIC_LIBPYTHON)" = 1; then \
 		if test -d $(LIBRARY); then :; else \
 			if test "$(PYTHONFRAMEWORKDIR)" = no-framework; then \
-				if test "$(SHLIB_SUFFIX)" = .dll; then \
-					$(INSTALL_DATA) $(LDLIBRARY) $(DESTDIR)$(LIBPL) ; \
+				if test "$(SHLIB_SUFFIX)" = .dll -o "$(SHLIB_SUFFIX)" = .pyd; then \
+					$(INSTALL_DATA) $(LDLIBRARY) $(DESTDIR)$(LIBDIR) ; \
+					$(INSTALL_DATA) $(ABI3LDLIBRARY) $(DESTDIR)$(LIBDIR) ; \
 				else \
 					$(INSTALL_DATA) $(LIBRARY) $(DESTDIR)$(LIBPL)/$(LIBRARY) ; \
 				fi; \
@@ -2263,16 +2314,23 @@ libainstall: all python-config
 	else true; \
 	fi
 
+ifeq ($(shell uname -o),Msys)
+DESTDIRFINAL=$(DESTDIR)
+else
+DESTDIRFINAL=$(DESTDIR)/
+endif
+
 # Install the dynamically loadable modules
 # This goes into $(exec_prefix)
 sharedinstall: all
+	MSYS2_ARG_CONV_EXCL="--prefix=;--install-scripts=;--install-platlib=" \
 	$(RUNSHARED) $(PYTHON_FOR_BUILD) $(srcdir)/setup.py install \
 	   	--prefix=$(prefix) \
 		--install-scripts=$(BINDIR) \
 		--install-platlib=$(DESTSHARED) \
-		--root=$(DESTDIR)/
-	-rm $(DESTDIR)$(DESTSHARED)/_sysconfigdata_$(ABIFLAGS)_$(MACHDEP)_$(MULTIARCH).py
-	-rm -r $(DESTDIR)$(DESTSHARED)/__pycache__
+		--root=$(DESTDIRFINAL)
+	-rm $(DESTDIRFINAL)$(DESTSHARED)/_sysconfigdata_$(ABIFLAGS)_$(MACHDEP)_$(MULTIARCH).py
+	-rm -r $(DESTDIRFINAL)$(DESTSHARED)/__pycache__
 
 # Here are a couple of targets for MacOSX again, to install a full
 # framework-based Python. frameworkinstall installs everything, the
@@ -2464,7 +2522,7 @@ clean: clean-retain-profile
 	fi
 
 clobber: clean
-	-rm -f $(BUILDPYTHON) $(LIBRARY) $(LDLIBRARY) $(DLLLIBRARY) \
+	-rm -f $(BUILDPYTHON) $(LIBRARY) $(LDLIBRARY) $(DLLLIBRARY)$(ABI3LDLIBRARY) $(ABI3DLLLIBRARY) \
 		tags TAGS \
 		config.cache config.log pyconfig.h Modules/config.c
 	-rm -rf build platform
diff --git a/Misc/NEWS.d/3.11.4.rst b/Misc/NEWS.d/3.11.4.rst
new file mode 100755
index 0000000..71ed43d
--- /dev/null
+++ b/Misc/NEWS.d/3.11.4.rst
@@ -0,0 +1,785 @@
+.. date: 2023-06-01-03-24-58
+.. gh-issue: 103142
+.. nonce: GLWDMX
+.. release date: 2023-06-06
+.. section: Security
+
+The version of OpenSSL used in our binary builds has been upgraded to 1.1.1u
+to address several CVEs.
+
+..
+
+.. date: 2023-05-02-17-56-32
+.. gh-issue: 99889
+.. nonce: l664SU
+.. section: Security
+
+Fixed a security in flaw in :func:`uu.decode` that could allow for directory
+traversal based on the input if no ``out_file`` was specified.
+
+..
+
+.. date: 2023-05-01-15-03-25
+.. gh-issue: 104049
+.. nonce: b01Y3g
+.. section: Security
+
+Do not expose the local on-disk location in directory indexes produced by
+:class:`http.client.SimpleHTTPRequestHandler`.
+
+..
+
+.. date: 2023-03-07-20-59-17
+.. gh-issue: 102153
+.. nonce: 14CLSZ
+.. section: Security
+
+:func:`urllib.parse.urlsplit` now strips leading C0 control and space
+characters following the specification for URLs defined by WHATWG in
+response to CVE-2023-24329. Patch by Illia Volochii.
+
+..
+
+.. date: 2023-05-31-19-35-22
+.. gh-issue: 105164
+.. nonce: 6Wajph
+.. section: Core and Builtins
+
+Ensure annotations are set up correctly if the only annotation in a block is
+within a :keyword:`match` block. Patch by Jelle Zijlstra.
+
+..
+
+.. date: 2023-05-18-13-00-21
+.. gh-issue: 104615
+.. nonce: h_rtw2
+.. section: Core and Builtins
+
+Fix wrong ordering of assignments in code like ``a, a = x, y``. Contributed
+by Carl Meyer.
+
+..
+
+.. date: 2023-05-14-18-56-54
+.. gh-issue: 104482
+.. nonce: yaQsv8
+.. section: Core and Builtins
+
+Fix three error handling bugs in ast.c's validation of pattern matching
+statements.
+
+..
+
+.. date: 2023-05-13-06-22-52
+.. gh-issue: 102818
+.. nonce: HIX1Dr
+.. section: Core and Builtins
+
+Do not add a frame to the traceback in the ``sys.setprofile`` and
+``sys.settrace`` trampoline functions. This ensures that frames are not
+duplicated if an exception is raised in the callback function, and ensures
+that frames are not omitted if a C callback is used and that does not add
+the frame.
+
+..
+
+.. date: 2023-05-12-00-19-02
+.. gh-issue: 104405
+.. nonce: tXV5fn
+.. section: Core and Builtins
+
+Fix an issue where some :term:`bytecode` instructions could ignore
+:pep:`523` when "inlining" calls.
+
+..
+
+.. date: 2023-05-01-12-03-52
+.. gh-issue: 104018
+.. nonce: PFxGS4
+.. section: Core and Builtins
+
+Disallow the "z" format specifier in %-format of bytes objects.
+
+..
+
+.. date: 2023-04-28-18-57-13
+.. gh-issue: 103971
+.. nonce: Q3U9lv
+.. section: Core and Builtins
+
+Fix an issue where incorrect locations numbers could be assigned to code
+following ``case`` blocks.
+
+..
+
+.. date: 2023-04-21-17-03-14
+.. gh-issue: 102310
+.. nonce: anLjDx
+.. section: Core and Builtins
+
+Change the error range for invalid bytes literals.
+
+..
+
+.. date: 2023-04-21-16-12-41
+.. gh-issue: 103590
+.. nonce: 7DHDOE
+.. section: Core and Builtins
+
+Do not wrap a single exception raised from a ``try-except*`` construct in an
+:exc:`ExceptionGroup`.
+
+..
+
+.. date: 2023-04-14-22-35-23
+.. gh-issue: 101517
+.. nonce: 5EqM-S
+.. section: Core and Builtins
+
+Fix bug in line numbers of instructions emitted for :keyword:`except*
+<except_star>`.
+
+..
+
+.. date: 2023-04-08-17-13-07
+.. gh-issue: 103242
+.. nonce: ysI1b3
+.. section: Core and Builtins
+
+Migrate :meth:`~ssl.SSLContext.set_ecdh_curve` method not to use deprecated
+OpenSSL APIs. Patch by Dong-hee Na.
+
+..
+
+.. date: 2023-04-01-00-46-31
+.. gh-issue: 102700
+.. nonce: 493NB4
+.. section: Core and Builtins
+
+Allow built-in modules to be submodules. This allows submodules to be
+statically linked into a CPython binary.
+
+..
+
+.. date: 2023-02-12-22-40-22
+.. gh-issue: 101857
+.. nonce: _bribG
+.. section: Core and Builtins
+
+Fix xattr support detection on Linux systems by widening the check to linux,
+not just glibc. This fixes support for musl.
+
+..
+
+.. date: 2022-11-08-12-36-25
+.. gh-issue: 99184
+.. nonce: KIaqzz
+.. section: Core and Builtins
+
+Bypass instance attribute access of ``__name__`` in ``repr`` of
+:class:`weakref.ref`.
+
+..
+
+.. date: 2022-09-27-11-59-13
+.. gh-issue: 96670
+.. nonce: XrBBit
+.. section: Core and Builtins
+
+The parser now raises :exc:`SyntaxError` when parsing source code containing
+null bytes. Backported from ``aab01e3``. Patch by Pablo Galindo
+
+..
+
+.. bpo: 31821
+.. date: 2019-12-01-12-58-31
+.. nonce: 1FNmwk
+.. section: Core and Builtins
+
+Fix :func:`!pause_reading` to work when called from :func:`!connection_made`
+in :mod:`asyncio`.
+
+..
+
+.. date: 2023-06-02-02-38-26
+.. gh-issue: 105080
+.. nonce: 2imGMg
+.. section: Library
+
+Fixed inconsistent signature on derived classes for
+:func:`inspect.signature`
+
+..
+
+.. date: 2023-05-24-09-34-23
+.. gh-issue: 104874
+.. nonce: oqyJSy
+.. section: Library
+
+Document the ``__name__`` and ``__supertype__`` attributes of
+:class:`typing.NewType`. Patch by Jelle Zijlstra.
+
+..
+
+.. date: 2023-05-17-20-03-01
+.. gh-issue: 104340
+.. nonce: kp_XmX
+.. section: Library
+
+When an ``asyncio`` pipe protocol loses its connection due to an error, and
+the caller doesn't await ``wait_closed()`` on the corresponding
+``StreamWriter``, don't log a warning about an exception that was never
+retrieved. After all, according to the ``StreamWriter.close()`` docs, the
+``wait_closed()`` call is optional ("not mandatory").
+
+..
+
+.. date: 2023-05-17-08-01-36
+.. gh-issue: 104372
+.. nonce: jpoWs6
+.. section: Library
+
+Refactored the ``_posixsubprocess`` internals to avoid Python C API usage
+between fork and exec when marking ``pass_fds=`` file descriptors
+inheritable.
+
+..
+
+.. date: 2023-05-16-11-02-44
+.. gh-issue: 75367
+.. nonce: qLWR35
+.. section: Library
+
+Fix data descriptor detection in  :func:`inspect.getattr_static`.
+
+..
+
+.. date: 2023-05-16-10-07-16
+.. gh-issue: 104536
+.. nonce: hFWD8f
+.. section: Library
+
+Fix a race condition in the internal :mod:`multiprocessing.process` cleanup
+logic that could manifest as an unintended ``AttributeError`` when calling
+``process.close()``.
+
+..
+
+.. date: 2023-05-11-23-03-00
+.. gh-issue: 104399
+.. nonce: MMatTP
+.. section: Library
+
+Prepare the ``_tkinter`` module for building with Tcl 9.0 and future
+libtommath by replacing usage of deprecated functions
+:c:func:`mp_to_unsigned_bin_n` and :c:func:`mp_unsigned_bin_size` when
+necessary.
+
+..
+
+.. date: 2023-05-08-20-57-17
+.. gh-issue: 104307
+.. nonce: DSB93G
+.. section: Library
+
+:func:`socket.getnameinfo` now releases the GIL while contacting the DNS
+server
+
+..
+
+.. date: 2023-05-08-15-39-00
+.. gh-issue: 87695
+.. nonce: f6iO7v
+.. section: Library
+
+Fix issue where :meth:`pathlib.Path.glob` raised :exc:`OSError` when it
+encountered a symlink to an overly long path.
+
+..
+
+.. date: 2023-05-07-19-56-45
+.. gh-issue: 104265
+.. nonce: fVblry
+.. section: Library
+
+Prevent possible crash by disallowing instantiation of the
+:class:`!_csv.Reader` and :class:`!_csv.Writer` types. The regression was
+introduced in 3.10.0a4 with PR 23224 (:issue:`14935`). Patch by Radislav
+Chugunov.
+
+..
+
+.. date: 2023-05-01-16-43-28
+.. gh-issue: 104035
+.. nonce: MrJBw8
+.. section: Library
+
+Do not ignore user-defined ``__getstate__`` and ``__setstate__`` methods for
+slotted frozen dataclasses.
+
+..
+
+.. date: 2023-04-29-18-23-16
+.. gh-issue: 103987
+.. nonce: sRgALL
+.. section: Library
+
+In :mod:`mmap`, fix several bugs that could lead to access to memory-mapped
+files after they have been invalidated.
+
+..
+
+.. date: 2023-04-27-20-03-08
+.. gh-issue: 103935
+.. nonce: Uaf2M0
+.. section: Library
+
+Use :func:`io.open_code` for files to be executed instead of raw
+:func:`open`
+
+..
+
+.. date: 2023-04-27-00-45-41
+.. gh-issue: 100370
+.. nonce: MgZ3KY
+.. section: Library
+
+Fix potential :exc:`OverflowError` in :meth:`sqlite3.Connection.blobopen`
+for 32-bit builds. Patch by Erlend E. Aasland.
+
+..
+
+.. date: 2023-04-26-09-54-25
+.. gh-issue: 103848
+.. nonce: aDSnpR
+.. section: Library
+
+Add checks to ensure that ``[`` bracketed ``]`` hosts found by
+:func:`urllib.parse.urlsplit` are of IPv6 or IPvFuture format.
+
+..
+
+.. date: 2023-04-26-09-38-47
+.. gh-issue: 103872
+.. nonce: 8LBsDz
+.. section: Library
+
+Update the bundled copy of pip to version 23.1.2.
+
+..
+
+.. date: 2023-04-25-19-58-13
+.. gh-issue: 103861
+.. nonce: JeozgD
+.. section: Library
+
+Fix ``zipfile.Zipfile`` creating invalid zip files when ``force_zip64`` was
+used to add files to them. Patch by Carey Metcalfe.
+
+..
+
+.. date: 2023-04-24-00-34-23
+.. gh-issue: 103685
+.. nonce: U14jBM
+.. section: Library
+
+Prepare :meth:`tkinter.Menu.index` for Tk 8.7 so that it does not raise
+``TclError: expected integer but got ""`` when it should return ``None``.
+
+..
+
+.. date: 2023-04-22-22-14-09
+.. gh-issue: 81403
+.. nonce: zVz9Td
+.. section: Library
+
+:class:`urllib.request.CacheFTPHandler` no longer raises :class:`URLError`
+if a cached FTP instance is reused. ftplib's endtransfer method calls
+voidresp to drain the connection to handle FTP instance reuse properly.
+
+..
+
+.. date: 2023-04-16-18-29-04
+.. gh-issue: 103578
+.. nonce: fly1wc
+.. section: Library
+
+Fixed a bug where :mod:`pdb` crashes when reading source file with different
+encoding by replacing :func:`io.open` with :func:`io.open_code`. The new
+method would also call into the hook set by :func:`PyFile_SetOpenCodeHook`.
+
+..
+
+.. date: 2023-04-15-12-19-14
+.. gh-issue: 103556
+.. nonce: TEf-2m
+.. section: Library
+
+Now creating :class:`inspect.Signature` objects with positional-only
+parameter with a default followed by a positional-or-keyword parameter
+without one is impossible.
+
+..
+
+.. date: 2023-04-15-11-21-38
+.. gh-issue: 103559
+.. nonce: a9rYHG
+.. section: Library
+
+Update the bundled copy of pip to version 23.1.1.
+
+..
+
+.. date: 2023-04-12-17-59-55
+.. gh-issue: 103365
+.. nonce: UBEE0U
+.. section: Library
+
+Set default Flag boundary to ``STRICT`` and fix bitwise operations.
+
+..
+
+.. date: 2023-04-12-13-04-16
+.. gh-issue: 103472
+.. nonce: C6bOHv
+.. section: Library
+
+Avoid a potential :exc:`ResourceWarning` in
+:class:`http.client.HTTPConnection` by closing the proxy / tunnel's CONNECT
+response explicitly.
+
+..
+
+.. date: 2023-04-11-21-38-39
+.. gh-issue: 103449
+.. nonce: -nxmhb
+.. section: Library
+
+Fix a bug in doc string generation in :func:`dataclasses.dataclass`.
+
+..
+
+.. date: 2023-04-06-17-28-36
+.. gh-issue: 103256
+.. nonce: 1syxfs
+.. section: Library
+
+Fixed a bug that caused :mod:`hmac` to raise an exception when the requested
+hash algorithm was not available in OpenSSL despite being available
+separately as part of ``hashlib`` itself.  It now falls back properly to the
+built-in. This could happen when, for example, your OpenSSL does not include
+SHA3 support and you want to compute ``hmac.digest(b'K', b'M',
+'sha3_256')``.
+
+..
+
+.. date: 2023-04-05-01-28-53
+.. gh-issue: 103225
+.. nonce: QD3JVU
+.. section: Library
+
+Fix a bug in :mod:`pdb` when displaying line numbers of module-level source
+code.
+
+..
+
+.. date: 2023-04-04-12-43-38
+.. gh-issue: 93910
+.. nonce: jurMzv
+.. section: Library
+
+Remove deprecation of enum ``memmber.member`` access.
+
+..
+
+.. date: 2023-04-03-23-44-34
+.. gh-issue: 102978
+.. nonce: gy9eVk
+.. section: Library
+
+Fixes :func:`unittest.mock.patch` not enforcing function signatures for
+methods decorated with ``@classmethod`` or ``@staticmethod`` when patch is
+called with ``autospec=True``.
+
+..
+
+.. date: 2023-04-02-23-05-22
+.. gh-issue: 103204
+.. nonce: bbDmu0
+.. section: Library
+
+Fixes :mod:`http.server` accepting HTTP requests with HTTP version numbers
+preceded by '+', or '-', or with digit-separating '_' characters.  The
+length of the version numbers is also constrained.
+
+..
+
+.. date: 2023-03-23-15-24-38
+.. gh-issue: 102953
+.. nonce: YR4KaK
+.. section: Library
+
+The extraction methods in :mod:`tarfile`, and :func:`shutil.unpack_archive`,
+have a new a *filter* argument that allows limiting tar features than may be
+surprising or dangerous, such as creating files outside the destination
+directory. See :ref:`tarfile-extraction-filter` for details.
+
+..
+
+.. date: 2023-02-09-22-24-34
+.. gh-issue: 101640
+.. nonce: oFuEpB
+.. section: Library
+
+:class:`argparse.ArgumentParser` now catches errors when writing messages,
+such as when :data:`sys.stderr` is ``None``. Patch by Oleg Iarygin.
+
+..
+
+.. date: 2022-09-07-09-32-07
+.. gh-issue: 96522
+.. nonce: t73oqp
+.. section: Library
+
+Fix potential deadlock in pty.spawn()
+
+..
+
+.. date: 2022-08-27-21-41-41
+.. gh-issue: 87474
+.. nonce: 9X-kxt
+.. section: Library
+
+Fix potential file descriptor leaks in :class:`subprocess.Popen`.
+
+..
+
+.. date: 2023-05-28-21-01-00
+.. gh-issue: 89455
+.. nonce: qAKRrA
+.. section: Documentation
+
+Add missing documentation for the ``max_group_depth`` and
+``max_group_width`` parameters and the ``exceptions`` attribute of the
+:class:`traceback.TracebackException` class.
+
+..
+
+.. date: 2023-05-28-19-08-42
+.. gh-issue: 89412
+.. nonce: j4cg7K
+.. section: Documentation
+
+Add missing documentation for the ``end_lineno`` and ``end_offset``
+attributes of the :class:`traceback.TracebackException` class.
+
+..
+
+.. date: 2023-05-25-22-34-31
+.. gh-issue: 104943
+.. nonce: J2v1Pc
+.. section: Documentation
+
+Remove mentions of old Python versions in :class:`typing.NamedTuple`.
+
+..
+
+.. date: 2023-05-14-12-11-28
+.. gh-issue: 67056
+.. nonce: nVC2Rf
+.. section: Documentation
+
+Document that the effect of registering or unregistering an :mod:`atexit`
+cleanup function from within a registered cleanup function is undefined.
+
+..
+
+.. date: 2023-04-25-22-58-08
+.. gh-issue: 48241
+.. nonce: l1Gxxh
+.. section: Documentation
+
+Clarifying documentation about the url parameter to urllib.request.urlopen
+and urllib.request.Requst needing to be encoded properly.
+
+..
+
+.. date: 2023-05-15-02-22-44
+.. gh-issue: 104494
+.. nonce: Bkrbfn
+.. section: Tests
+
+Update ``test_pack_configure_in`` and ``test_place_configure_in`` for
+changes to error message formatting in Tk 8.7.
+
+..
+
+.. date: 2023-05-14-03-00-00
+.. gh-issue: 104461
+.. nonce: Rmex11
+.. section: Tests
+
+Run test_configure_screen on X11 only, since the ``DISPLAY`` environment
+variable and ``-screen`` option for toplevels are not useful on Tk for Win32
+or Aqua.
+
+..
+
+.. date: 2023-04-08-00-50-23
+.. gh-issue: 103329
+.. nonce: M38tqF
+.. section: Tests
+
+Regression tests for the behaviour of ``unittest.mock.PropertyMock`` were
+added.
+
+..
+
+.. date: 2023-02-11-22-36-10
+.. gh-issue: 85984
+.. nonce: EVXjT9
+.. section: Tests
+
+Utilize new "winsize" functions from termios in pty tests.
+
+..
+
+.. date: 2022-11-06-18-42-38
+.. gh-issue: 75729
+.. nonce: uGYJrv
+.. section: Tests
+
+Fix the :func:`os.spawn* <os.spawnl>` tests failing on Windows when the
+working directory or interpreter path contains spaces.
+
+..
+
+.. date: 2023-06-06-09-08-10
+.. gh-issue: 90005
+.. nonce: 8mmeJQ
+.. section: Build
+
+Fix a regression in :file:`configure` where we could end up unintentionally
+linking with ``libbsd``.
+
+..
+
+.. date: 2023-05-04-10-56-14
+.. gh-issue: 104106
+.. nonce: -W9BJS
+.. section: Build
+
+Add gcc fallback of mkfifoat/mknodat for macOS. Patch by Dong-hee Na.
+
+..
+
+.. date: 2023-02-11-05-31-05
+.. gh-issue: 99069
+.. nonce: X4LDvY
+.. section: Build
+
+Extended workaround defining ``static_assert`` when missing from the libc
+headers to all clang and gcc builds. In particular, this fixes building on
+macOS <= 10.10.
+
+..
+
+.. date: 2023-05-31-16-14-31
+.. gh-issue: 105146
+.. nonce: gNjqq8
+.. section: Windows
+
+Updated the links at the end of the installer to point to Discourse rather
+than the mailing lists.
+
+..
+
+.. date: 2023-05-18-22-46-03
+.. gh-issue: 104623
+.. nonce: HJZhm1
+.. section: Windows
+
+Update Windows installer to use SQLite 3.42.0.
+
+..
+
+.. date: 2023-03-24-11-25-28
+.. gh-issue: 102997
+.. nonce: dredy2
+.. section: Windows
+
+Update Windows installer to use SQLite 3.41.2.
+
+..
+
+.. date: 2023-03-18-21-38-00
+.. gh-issue: 88013
+.. nonce: Z3loxC
+.. section: Windows
+
+Fixed a bug where :exc:`TypeError` was raised when calling
+:func:`ntpath.realpath` with a bytes parameter in some cases.
+
+..
+
+.. date: 2023-05-30-23-30-46
+.. gh-issue: 103142
+.. nonce: 55lMXQ
+.. section: macOS
+
+Update macOS installer to use OpenSSL 1.1.1u.
+
+..
+
+.. date: 2023-05-18-22-31-49
+.. gh-issue: 104623
+.. nonce: 6h7Xfx
+.. section: macOS
+
+Update macOS installer to SQLite 3.42.0.
+
+..
+
+.. date: 2023-03-24-11-20-47
+.. gh-issue: 102997
+.. nonce: ZgQkbq
+.. section: macOS
+
+Update macOS installer to SQLite 3.41.2.
+
+..
+
+.. date: 2023-05-23-17-19-49
+.. gh-issue: 104719
+.. nonce: rvYXH-
+.. section: IDLE
+
+Remove IDLE's modification of tokenize.tabsize and test other uses of
+tokenize data and methods.
+
+..
+
+.. date: 2023-05-17-17-32-21
+.. gh-issue: 104499
+.. nonce: hNeqV4
+.. section: IDLE
+
+Fix completions for Tk Aqua 8.7 (currently blank).
+
+..
+
+.. date: 2023-05-17-15-11-11
+.. gh-issue: 104496
+.. nonce: wjav-y
+.. section: IDLE
+
+About prints both tcl and tk versions if different (expected someday).
+
+..
+
+.. date: 2023-04-30-20-01-18
+.. gh-issue: 88496
+.. nonce: y65vUb
+.. section: IDLE
+
+Fix IDLE test hang on macOS.
diff --git a/Misc/config_mingw b/Misc/config_mingw
new file mode 100755
index 0000000..9be43fd
--- /dev/null
+++ b/Misc/config_mingw
@@ -0,0 +1,15 @@
+# configure defaults for mingw* hosts
+
+# mingw functions to ignore
+ac_cv_func_ftruncate=ignore	# implement it as _chsize
+
+# mingw-w64 functions to ignore
+ac_cv_func_truncate=ignore
+ac_cv_func_alarm=ignore
+
+# files to ignore
+ac_cv_file__dev_ptmx=ignore #NOTE: under MSYS environment device exist
+ac_cv_file__dev_ptc=no
+
+# force detection of winsock2 functionality - require wxp or newer
+ac_cv_func_getpeername=yes
diff --git a/Misc/cross_mingw32 b/Misc/cross_mingw32
new file mode 100755
index 0000000..03fde9e
--- /dev/null
+++ b/Misc/cross_mingw32
@@ -0,0 +1,11 @@
+# configure defaults for mingw32 host if cross-build
+
+ac_cv_little_endian_double=yes
+ac_cv_big_endian_double=no
+ac_cv_mixed_endian_double=no
+
+ac_cv_tanh_preserves_zero_sign=yes
+
+ac_cv_wchar_t_signed=no
+
+ac_cv_have_size_t_format=no
diff --git a/Misc/python-config.sh.in b/Misc/python-config.sh.in
index 2602fe2..e0e048a 100644
--- a/Misc/python-config.sh.in
+++ b/Misc/python-config.sh.in
@@ -1,32 +1,44 @@
 #!/bin/sh
 
-# Keep this script in sync with python-config.in
-
 exit_with_usage ()
 {
     echo "Usage: $0 --prefix|--exec-prefix|--includes|--libs|--cflags|--ldflags|--extension-suffix|--help|--abiflags|--configdir|--embed"
-    exit $1
+    exit 1
 }
 
+# Really, python-config.py (and thus .sh) should be called directly, but
+# sometimes software (e.g. GDB) calls python-config.sh as if it were the
+# Python executable, passing python-config.py as the first argument.
+# Work around that oddness by ignoring any .py passed as first arg.
+case "$1" in
+    *.py)
+        shift
+    ;;
+esac
+
 if [ "$1" = "" ] ; then
-    exit_with_usage 1
+    exit_with_usage
 fi
 
 # Returns the actual prefix where this script was installed to.
 installed_prefix ()
 {
-    RESULT=$(dirname $(cd $(dirname "$1") && pwd -P))
-    if which readlink >/dev/null 2>&1 ; then
-        if readlink -f "$RESULT" >/dev/null 2>&1; then
-          RESULT=$(readlink -f "$RESULT")
-        fi
+    local RESULT=$(dirname $(cd $(dirname "$1") && pwd -P))
+    if [ $(which readlink) ] ; then
+        RESULT=$(readlink -f "$RESULT")
+    fi
+    # Since we don't know where the output from this script will end up
+    # we keep all paths in Windows-land since MSYS2 can handle that
+    # while native tools can't handle paths in MSYS2-land.
+    if [ "$OSTYPE" = "msys" ]; then
+        RESULT=$(cd "$RESULT" && pwd -W)
     fi
     echo $RESULT
 }
 
 prefix_real=$(installed_prefix "$0")
 
-# Use sed to fix paths from their built-to locations to their installed-to
+# Use sed to fix paths from their built-to locations to their installed to
 # locations. Keep prefix & exec_prefix using their original values in case
 # they are referenced in other configure variables, to prevent double
 # substitution, issue #22140.
@@ -41,13 +53,17 @@ LIBM="@LIBM@"
 LIBC="@LIBC@"
 SYSLIBS="$LIBM $LIBC"
 ABIFLAGS="@ABIFLAGS@"
+# Protect against lack of substitution.
+if [ "$ABIFLAGS" = "@""ABIFLAGS""@" ] ; then
+    ABIFLAGS=
+fi
 LIBS="@LIBPYTHON@ @LIBS@ $SYSLIBS"
 LIBS_EMBED="-lpython${VERSION}${ABIFLAGS} @LIBS@ $SYSLIBS"
 BASECFLAGS="@BASECFLAGS@"
-LDLIBRARY="@LDLIBRARY@"
 OPT="@OPT@"
 PY_ENABLE_SHARED="@PY_ENABLE_SHARED@"
 LDVERSION="@LDVERSION@"
+LDLIBRARY="@LDLIBRARY@"
 LIBDEST=${prefix_real}/lib/python${VERSION}
 LIBPL=$(echo "@LIBPL@" | sed "s#$prefix#$prefix_real#")
 SO="@EXT_SUFFIX@"
@@ -61,7 +77,7 @@ for ARG in $*
 do
     case $ARG in
         --help)
-            exit_with_usage 0
+            exit_with_usage
         ;;
         --embed)
             PY_EMBED=1
@@ -69,7 +85,7 @@ do
         --prefix|--exec-prefix|--includes|--libs|--cflags|--ldflags|--extension-suffix|--abiflags|--configdir)
         ;;
         *)
-            exit_with_usage 1
+            exit_with_usage
         ;;
     esac
 done
@@ -80,37 +96,37 @@ fi
 
 for ARG in "$@"
 do
-    case "$ARG" in
+    case $ARG in
         --prefix)
-            echo "$prefix_real"
+            echo -ne "$prefix_real"
         ;;
         --exec-prefix)
-            echo "$exec_prefix_real"
+            echo -ne "$exec_prefix_real "
         ;;
         --includes)
-            echo "$INCDIR $PLATINCDIR"
+            echo -ne "$INCDIR $PLATINCDIR"
         ;;
         --cflags)
-            echo "$INCDIR $PLATINCDIR $BASECFLAGS $CFLAGS $OPT"
+            echo -ne "$INCDIR $PLATINCDIR $BASECFLAGS $CFLAGS $OPT"
         ;;
         --libs)
-            echo "$LIBS"
+            echo -ne "$LIBS"
         ;;
         --ldflags)
             LIBPLUSED=
             if [ "$PY_ENABLE_SHARED" = "0" ] ; then
                 LIBPLUSED="-L$LIBPL"
             fi
-            echo "$LIBPLUSED -L$libdir $LIBS"
+            echo -ne "$LIBPLUSED -L$libdir $LIBS "
         ;;
         --extension-suffix)
-            echo "$SO"
+            echo -ne "$SO "
         ;;
         --abiflags)
-            echo "$ABIFLAGS"
+            echo -ne "$ABIFLAGS "
         ;;
         --configdir)
-            echo "$LIBPL"
+            echo -ne "$LIBPL "
         ;;
 esac
 done
diff --git a/Misc/python.pc.in b/Misc/python.pc.in
index 87e04de..3900190 100644
--- a/Misc/python.pc.in
+++ b/Misc/python.pc.in
@@ -9,5 +9,5 @@ Description: Build a C extension for Python
 Requires:
 Version: @VERSION@
 Libs.private: @LIBS@
-Libs:
+Libs: -L${libdir} -lpython@VERSION@@ABIFLAGS@
 Cflags: -I${includedir}/python@VERSION@@ABIFLAGS@
diff --git a/Modules/Setup.bootstrap.in b/Modules/Setup.bootstrap.in
index e3e9b96..6986290 100644
--- a/Modules/Setup.bootstrap.in
+++ b/Modules/Setup.bootstrap.in
@@ -8,15 +8,15 @@
 # module C APIs are used in core
 atexit atexitmodule.c
 faulthandler faulthandler.c
-posix posixmodule.c
-_signal signalmodule.c
+@INITSYS@ posixmodule.c
+_signal signalmodule.c -lws2_32
 _tracemalloc _tracemalloc.c
 
 # modules used by importlib, deepfreeze, freeze, runpy, and sysconfig
 _codecs _codecsmodule.c
 _collections _collectionsmodule.c
 errno errnomodule.c
-_io _io/_iomodule.c _io/iobase.c _io/fileio.c _io/bytesio.c _io/bufferedio.c _io/textio.c _io/stringio.c
+_io _io/_iomodule.c _io/iobase.c _io/fileio.c _io/bytesio.c _io/bufferedio.c _io/textio.c _io/stringio.c _io/winconsoleio.c
 itertools itertoolsmodule.c
 _sre _sre/sre.c
 _thread _threadmodule.c
@@ -33,3 +33,8 @@ _symtable symtablemodule.c
 
 # for systems without $HOME env, used by site._getuserbase()
 @MODULE_PWD_TRUE@pwd pwdmodule.c
+
+# build-in modules for windows platform:
+@USE_WIN32_MODULE@winreg ../PC/winreg.c
+@MODULE_MSVCRT_TRUE@msvcrt -DPy_BUILD_CORE ../PC/msvcrtmodule.c
+@MODULE__WINAPI_TRUE@_winapi _winapi.c
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index fc73264..6ed71fa 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -3403,6 +3403,18 @@ static PPROC FindAddress(void *handle, const char *name, PyObject *type)
     mangled_name = alloca(strlen(name) + 1 + 1 + 1 + 3); /* \0 _ @ %d */
     if (!mangled_name)
         return NULL;
+    /* Issue: for stdcall decorated export functions MSVC compiler adds
+     * underscore, but GCC compiler create them without. This is
+     * visible by example for _ctypes_test.pyd module.
+     * As well functions from system libraries are without underscore.
+     * Solutions:
+     * - If a python module is build with gcc option --add-stdcall-alias
+     * the module will contain XXX as alias for function XXX@ as result
+     * first search in this method will succeed.
+     * - Distutil may use compiler to create def-file, to modify it as
+     * add underscore alias and with new def file to create module.
+     * - Or may be just to search for function without underscore.
+     */
     for (i = 0; i < 32; ++i) {
         sprintf(mangled_name, "_%s@%d", name, i*4);
         Py_BEGIN_ALLOW_THREADS
@@ -3410,6 +3422,13 @@ static PPROC FindAddress(void *handle, const char *name, PyObject *type)
         Py_END_ALLOW_THREADS
         if (address)
             return address;
+        /* search for function without underscore as weel */
+        sprintf(mangled_name, "%s@%d", name, i*4);
+        Py_BEGIN_ALLOW_THREADS
+        address = (PPROC)GetProcAddress(handle, mangled_name);
+        Py_END_ALLOW_THREADS
+        if (address)
+            return address;
     }
     return NULL;
 #endif
diff --git a/Modules/_gdbmmodule.c b/Modules/_gdbmmodule.c
index e6440fa..f42714a 100644
--- a/Modules/_gdbmmodule.c
+++ b/Modules/_gdbmmodule.c
@@ -12,7 +12,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
-#if defined(WIN32) && !defined(__CYGWIN__)
+#if defined(WIN32) && !defined(__CYGWIN__) && !defined(__MINGW32__)
 #include "gdbmerrno.h"
 extern const char * gdbm_strerror(gdbm_error);
 #endif
diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c
index 4496609..80cc6f9 100644
--- a/Modules/_io/fileio.c
+++ b/Modules/_io/fileio.c
@@ -20,6 +20,7 @@
 #endif
 #include <stddef.h> /* For offsetof */
 #include "_iomodule.h"
+#include "iscygpty.h"
 
 /*
  * Known likely problems:
@@ -1129,7 +1130,7 @@ _io_FileIO_isatty_impl(fileio *self)
         return err_closed();
     Py_BEGIN_ALLOW_THREADS
     _Py_BEGIN_SUPPRESS_IPH
-    res = isatty(self->fd);
+    res = isatty(self->fd) || is_cygpty(self->fd);
     _Py_END_SUPPRESS_IPH
     Py_END_ALLOW_THREADS
     return PyBool_FromLong(res);
diff --git a/Modules/_localemodule.c b/Modules/_localemodule.c
index 23c38e1..dfb6c7e 100644
--- a/Modules/_localemodule.c
+++ b/Modules/_localemodule.c
@@ -12,6 +12,13 @@ This software comes with no warranty. Use at your own risk.
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
 #include "pycore_fileutils.h"
+#ifdef __MINGW32__
+/* The header libintl.h and library libintl may exist on mingw host.
+ * To be compatible with MSVC build we has to undef some defines.
+ */
+#undef HAVE_LIBINTL_H
+#undef HAVE_BIND_TEXTDOMAIN_CODESET
+#endif
 
 #include <stdio.h>
 #include <locale.h>
diff --git a/Modules/_multiprocessing/multiprocessing.c b/Modules/_multiprocessing/multiprocessing.c
index 0809c24..bbb1b38 100644
--- a/Modules/_multiprocessing/multiprocessing.c
+++ b/Modules/_multiprocessing/multiprocessing.c
@@ -172,7 +172,7 @@ static PyMethodDef module_methods[] = {
     _MULTIPROCESSING_RECV_METHODDEF
     _MULTIPROCESSING_SEND_METHODDEF
 #endif
-#if !defined(POSIX_SEMAPHORES_NOT_ENABLED) && !defined(__ANDROID__)
+#if defined(MS_WINDOWS) || (!defined(POSIX_SEMAPHORES_NOT_ENABLED) && !defined(__ANDROID__))
     _MULTIPROCESSING_SEM_UNLINK_METHODDEF
 #endif
     {NULL}
diff --git a/Modules/_multiprocessing/multiprocessing.h b/Modules/_multiprocessing/multiprocessing.h
index 3a8314b..c07cfe8 100644
--- a/Modules/_multiprocessing/multiprocessing.h
+++ b/Modules/_multiprocessing/multiprocessing.h
@@ -21,7 +21,10 @@
 #  endif
 #  define SEM_HANDLE HANDLE
 #  define SEM_VALUE_MAX LONG_MAX
-#  define HAVE_MP_SEMAPHORE
+#    define HAVE_MP_SEMAPHORE
+#  if defined(HAVE_SEM_OPEN) && defined(_POSIX_THREADS)
+#    include <semaphore.h>
+#  endif
 #else
 #  include <fcntl.h>                 /* O_CREAT and O_EXCL */
 #  if defined(HAVE_SEM_OPEN) && !defined(POSIX_SEMAPHORES_NOT_ENABLED)
diff --git a/Modules/_winapi.c b/Modules/_winapi.c
index f6bb07f..56f3306 100644
--- a/Modules/_winapi.c
+++ b/Modules/_winapi.c
@@ -41,7 +41,9 @@
 
 #define WINDOWS_LEAN_AND_MEAN
 #include "windows.h"
+#if defined(Py_DEBUG)
 #include <crtdbg.h>
+#endif
 #include "winreparse.h"
 
 #if defined(MS_WIN32) && !defined(MS_WIN64)
@@ -957,7 +959,7 @@ getattributelist(PyObject *obj, const char *name, AttributeList *attribute_list)
     DWORD err;
     BOOL result;
     PyObject *value;
-    Py_ssize_t handle_list_size;
+    Py_ssize_t handle_list_size = 0;
     DWORD attribute_count = 0;
     SIZE_T attribute_list_size = 0;
 
diff --git a/Modules/_xxsubinterpretersmodule.c b/Modules/_xxsubinterpretersmodule.c
index e5b96be..0e5ab45 100644
--- a/Modules/_xxsubinterpretersmodule.c
+++ b/Modules/_xxsubinterpretersmodule.c
@@ -1765,7 +1765,7 @@ PyDoc_STRVAR(channelid_doc,
 "A channel ID identifies a channel and may be used as an int.");
 
 static PyTypeObject ChannelIDtype = {
-    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    PyVarObject_HEAD_INIT(NULL, 0)
     "_xxsubinterpreters.ChannelID", /* tp_name */
     sizeof(channelid),              /* tp_basicsize */
     0,                              /* tp_itemsize */
diff --git a/Modules/getpath.c b/Modules/getpath.c
index bc730fc..0419c2a 100644
--- a/Modules/getpath.c
+++ b/Modules/getpath.c
@@ -54,6 +54,25 @@
 
 /* HELPER FUNCTIONS for getpath.py */
 
+static PyObject *
+getpath_normpath(PyObject *Py_UNUSED(self), PyObject *args)
+{
+    PyObject *r = NULL;
+    PyObject *pathobj;
+    wchar_t *path;
+    if (!PyArg_ParseTuple(args, "U", &pathobj)) {
+        return NULL;
+    }
+    Py_ssize_t len;
+    wchar_t *buffer = PyUnicode_AsWideCharString(pathobj, &len);
+    if (!buffer) {
+        return NULL;
+    }
+    r = PyUnicode_FromWideChar(_Py_normpath(buffer, len), -1);
+    PyMem_Free(buffer);
+    return r;
+}
+
 static PyObject *
 getpath_abspath(PyObject *Py_UNUSED(self), PyObject *args)
 {
@@ -88,6 +107,12 @@ getpath_basename(PyObject *Py_UNUSED(self), PyObject *args)
     }
     Py_ssize_t end = PyUnicode_GET_LENGTH(path);
     Py_ssize_t pos = PyUnicode_FindChar(path, SEP, 0, end, -1);
+#ifdef ALTSEP
+    if (pos < 0) {
+        // try using altsep
+        pos = PyUnicode_FindChar(path, ALTSEP, 0, end, -1);
+    }
+#endif
     if (pos < 0) {
         return Py_NewRef(path);
     }
@@ -104,6 +129,12 @@ getpath_dirname(PyObject *Py_UNUSED(self), PyObject *args)
     }
     Py_ssize_t end = PyUnicode_GET_LENGTH(path);
     Py_ssize_t pos = PyUnicode_FindChar(path, SEP, 0, end, -1);
+#ifdef ALTSEP
+    if (pos < 0) {
+        // try using altsep
+        pos = PyUnicode_FindChar(path, ALTSEP, 0, end, -1);
+    }
+#endif
     if (pos < 0) {
         return PyUnicode_FromStringAndSize(NULL, 0);
     }
@@ -513,6 +544,7 @@ getpath_realpath(PyObject *Py_UNUSED(self) , PyObject *args)
 
 
 static PyMethodDef getpath_methods[] = {
+    {"normpath", getpath_normpath, METH_VARARGS, NULL},
     {"abspath", getpath_abspath, METH_VARARGS, NULL},
     {"basename", getpath_basename, METH_VARARGS, NULL},
     {"dirname", getpath_dirname, METH_VARARGS, NULL},
@@ -884,6 +916,11 @@ _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
 #else
         !decode_to_dict(dict, "os_name", "posix") ||
 #endif
+#ifdef __MINGW32__
+        !int_to_dict(dict, "is_mingw", 1) ||
+#else
+        !int_to_dict(dict, "is_mingw", 0) ||
+#endif
 #ifdef WITH_NEXT_FRAMEWORK
         !int_to_dict(dict, "WITH_NEXT_FRAMEWORK", 1) ||
 #else
@@ -910,6 +947,9 @@ _PyConfig_InitPathConfig(PyConfig *config, int compute_path_config)
         !funcs_to_dict(dict, config->pathconfig_warnings) ||
 #ifndef MS_WINDOWS
         PyDict_SetItemString(dict, "winreg", Py_None) < 0 ||
+#endif
+#ifdef __MINGW32__
+        !env_to_dict(dict, "ENV_MSYSTEM", 0) ||
 #endif
         PyDict_SetItemString(dict, "__builtins__", PyEval_GetBuiltins()) < 0
     ) {
diff --git a/Modules/getpath.py b/Modules/getpath.py
index 74f918c..c98cb1f 100644
--- a/Modules/getpath.py
+++ b/Modules/getpath.py
@@ -30,6 +30,7 @@
 
 # ** Values known at compile time **
 # os_name           -- [in] one of 'nt', 'posix', 'darwin'
+# is_mingw          -- [in] True if targeting MinGW
 # PREFIX            -- [in] sysconfig.get_config_var(...)
 # EXEC_PREFIX       -- [in] sysconfig.get_config_var(...)
 # PYTHONPATH        -- [in] sysconfig.get_config_var(...)
@@ -51,6 +52,7 @@
 # ENV_PYTHONHOME          -- [in] getenv(...)
 # ENV_PYTHONEXECUTABLE    -- [in] getenv(...)
 # ENV___PYVENV_LAUNCHER__ -- [in] getenv(...)
+# ENV_MSYSTEM             -- [in] getenv(...)
 
 # ** Values calculated at runtime **
 # config            -- [in/out] dict of the PyConfig structure
@@ -185,8 +187,27 @@
     ZIP_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}{VERSION_MINOR}.zip'
     DELIM = ':'
     SEP = '/'
+    ALTSEP = None
 
-elif os_name == 'nt':
+elif os_name == 'nt' and is_mingw:
+    BUILDDIR_TXT = 'pybuilddir.txt'
+    BUILD_LANDMARK = 'Modules/Setup.local'
+    DEFAULT_PROGRAM_NAME = f'python{VERSION_MAJOR}'
+    STDLIB_SUBDIR = f'{platlibdir}/python{VERSION_MAJOR}.{VERSION_MINOR}'
+    STDLIB_LANDMARKS = [f'{STDLIB_SUBDIR}/os.py', f'{STDLIB_SUBDIR}/os.pyc']
+    PLATSTDLIB_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}.{VERSION_MINOR}/lib-dynload'
+    BUILDSTDLIB_LANDMARKS = ['Lib/os.py']
+    VENV_LANDMARK = 'pyvenv.cfg'
+    ZIP_LANDMARK = f'{platlibdir}/python{VERSION_MAJOR}{VERSION_MINOR}.zip'
+    DELIM = ';'
+    if ENV_MSYSTEM:
+        SEP = '/'
+        ALTSEP = '\\'
+    else:
+        SEP = '\\'
+        ALTSEP = '/'
+
+elif os_name == 'nt': # MSVC
     BUILDDIR_TXT = 'pybuilddir.txt'
     BUILD_LANDMARK = f'{VPATH}\\Modules\\Setup.local'
     DEFAULT_PROGRAM_NAME = f'python'
@@ -199,6 +220,7 @@
     WINREG_KEY = f'SOFTWARE\\Python\\PythonCore\\{PYWINVER}\\PythonPath'
     DELIM = ';'
     SEP = '\\'
+    ALTSEP = '/'
 
 
 # ******************************************************************************
@@ -211,6 +233,8 @@ def search_up(prefix, *landmarks, test=isfile):
             return prefix
         prefix = dirname(prefix)
 
+def _normpath(p):
+    return normpath(p) if p is not None else None
 
 # ******************************************************************************
 # READ VARIABLES FROM config
@@ -263,10 +287,10 @@ def search_up(prefix, *landmarks, test=isfile):
     if not executable:
         executable = real_executable
 
-if not executable and SEP in program_name:
+if not executable and (SEP in program_name or 
+                       (ALTSEP and ALTSEP in program_name)):
     # Resolve partial path program_name against current directory
     executable = abspath(program_name)
-
 if not executable:
     # All platforms default to real_executable if known at this
     # stage. POSIX does not set this value.
@@ -497,15 +521,15 @@ def search_up(prefix, *landmarks, test=isfile):
     except (FileNotFoundError, PermissionError):
         if isfile(joinpath(real_executable_dir, BUILD_LANDMARK)):
             build_prefix = joinpath(real_executable_dir, VPATH)
-            if os_name == 'nt':
+            if os_name == 'nt' and not is_mingw:
                 # QUIRK: Windows builds need platstdlib_dir to be the executable
                 # dir. Normally the builddir marker handles this, but in this
                 # case we need to correct manually.
                 platstdlib_dir = real_executable_dir
 
     if build_prefix:
-        if os_name == 'nt':
-            # QUIRK: No searching for more landmarks on Windows
+        if os_name == 'nt' and not is_mingw:
+            # QUIRK: No searching for more landmarks on MSVC
             build_stdlib_prefix = build_prefix
         else:
             build_stdlib_prefix = search_up(build_prefix, *BUILDSTDLIB_LANDMARKS)
@@ -552,6 +576,9 @@ def search_up(prefix, *landmarks, test=isfile):
     # First try to detect prefix by looking alongside our runtime library, if known
     if library and not prefix:
         library_dir = dirname(library)
+        if os_name == 'nt' and is_mingw:
+            # QUIRK: On Windows, mingw Python DLLs are in the bin directory
+            library_dir = joinpath(library_dir, '..')
         if ZIP_LANDMARK:
             if os_name == 'nt':
                 # QUIRK: Windows does not search up for ZIP file
@@ -597,7 +624,7 @@ def search_up(prefix, *landmarks, test=isfile):
 
     # Detect exec_prefix by searching from executable for the platstdlib_dir
     if PLATSTDLIB_LANDMARK and not exec_prefix:
-        if os_name == 'nt':
+        if os_name == 'nt' and (not is_mingw):
             # QUIRK: Windows always assumed these were the same
             # gh-100320: Our PYDs are assumed to be relative to the Lib directory
             # (that is, prefix) rather than the executable (that is, executable_dir)
@@ -607,7 +634,7 @@ def search_up(prefix, *landmarks, test=isfile):
         if not exec_prefix and EXEC_PREFIX:
             exec_prefix = EXEC_PREFIX
         if not exec_prefix or not isdir(joinpath(exec_prefix, PLATSTDLIB_LANDMARK)):
-            if os_name == 'nt':
+            if os_name == 'nt' and (not is_mingw):
                 # QUIRK: If DLLs is missing on Windows, don't warn, just assume
                 # that they're in exec_prefix
                 if not platstdlib_dir:
@@ -645,7 +672,7 @@ def search_up(prefix, *landmarks, test=isfile):
 
 if py_setpath:
     # If Py_SetPath was called then it overrides any existing search path
-    config['module_search_paths'] = py_setpath.split(DELIM)
+    config['module_search_paths'] = [_normpath(p) for p in py_setpath.split(DELIM)]
     config['module_search_paths_set'] = 1
 
 elif not pythonpath_was_set:
@@ -660,7 +687,7 @@ def search_up(prefix, *landmarks, test=isfile):
             pythonpath.append(abspath(p))
 
     # Then add the default zip file
-    if os_name == 'nt':
+    if os_name == 'nt' and (not is_mingw):
         # QUIRK: Windows uses the library directory rather than the prefix
         if library:
             library_dir = dirname(library)
@@ -673,7 +700,7 @@ def search_up(prefix, *landmarks, test=isfile):
     else:
         pythonpath.append(joinpath(prefix, ZIP_LANDMARK))
 
-    if os_name == 'nt' and use_environment and winreg:
+    if (not is_mingw) and os_name == 'nt' and use_environment and winreg:
         # QUIRK: Windows also lists paths in the registry. Paths are stored
         # as the default value of each subkey of
         # {HKCU,HKLM}\Software\Python\PythonCore\{winver}\PythonPath
@@ -714,7 +741,7 @@ def search_up(prefix, *landmarks, test=isfile):
     if not platstdlib_dir and exec_prefix:
         platstdlib_dir = joinpath(exec_prefix, PLATSTDLIB_LANDMARK)
 
-    if os_name == 'nt':
+    if os_name == 'nt' and (not is_mingw):
         # QUIRK: Windows generates paths differently
         if platstdlib_dir:
             pythonpath.append(platstdlib_dir)
@@ -732,7 +759,7 @@ def search_up(prefix, *landmarks, test=isfile):
         if platstdlib_dir:
             pythonpath.append(platstdlib_dir)
 
-    config['module_search_paths'] = pythonpath
+    config['module_search_paths'] = [_normpath(p) for p in pythonpath]
     config['module_search_paths_set'] = 1
 
 
@@ -742,8 +769,8 @@ def search_up(prefix, *landmarks, test=isfile):
 
 # QUIRK: Non-Windows replaces prefix/exec_prefix with defaults when running
 # in build directory. This happens after pythonpath calculation.
-if os_name != 'nt' and build_prefix:
-    prefix = config.get('prefix') or PREFIX
+if (os_name != 'nt' or is_mingw) and build_prefix:
+    prefix = config.get('prefix') or abspath(PREFIX)
     exec_prefix = config.get('exec_prefix') or EXEC_PREFIX or prefix
 
 
@@ -767,23 +794,23 @@ def search_up(prefix, *landmarks, test=isfile):
             warn("unsupported 'import' line in ._pth file")
         else:
             pythonpath.append(joinpath(pth_dir, line))
-    config['module_search_paths'] = pythonpath
+    config['module_search_paths'] = [_normpath(p) for p in pythonpath]
     config['module_search_paths_set'] = 1
 
 # ******************************************************************************
 # UPDATE config FROM CALCULATED VALUES
 # ******************************************************************************
 
-config['program_name'] = program_name
-config['home'] = home
-config['executable'] = executable
-config['base_executable'] = base_executable
-config['prefix'] = prefix
-config['exec_prefix'] = exec_prefix
-config['base_prefix'] = base_prefix or prefix
-config['base_exec_prefix'] = base_exec_prefix or exec_prefix
+config['program_name'] = _normpath(program_name)
+config['home'] = _normpath(home)
+config['executable'] = _normpath(executable)
+config['base_executable'] = _normpath(base_executable)
+config['prefix'] = _normpath(prefix)
+config['exec_prefix'] = _normpath(exec_prefix)
+config['base_prefix'] = _normpath(base_prefix or prefix)
+config['base_exec_prefix'] = _normpath(base_exec_prefix or exec_prefix)
 
-config['platlibdir'] = platlibdir
+config['platlibdir'] = _normpath(platlibdir)
 # test_embed expects empty strings, not None
-config['stdlib_dir'] = stdlib_dir or ''
-config['platstdlib_dir'] = platstdlib_dir or ''
+config['stdlib_dir'] = _normpath(stdlib_dir or '')
+config['platstdlib_dir'] = _normpath(platstdlib_dir or '')
diff --git a/Modules/main.c b/Modules/main.c
index 6904e3f..5c8708e 100644
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -7,6 +7,7 @@
 #include "pycore_pathconfig.h"    // _PyPathConfig_ComputeSysPath0()
 #include "pycore_pylifecycle.h"   // _Py_PreInitializeFromPyArgv()
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
+#include "iscygpty.h"
 
 /* Includes for exit_sigint() */
 #include <stdio.h>                // perror()
@@ -92,7 +93,7 @@ static inline int config_run_code(const PyConfig *config)
 static int
 stdin_is_interactive(const PyConfig *config)
 {
-    return (isatty(fileno(stdin)) || config->interactive);
+    return (isatty(fileno(stdin)) || config->interactive || is_cygpty(fileno(stdin)));
 }
 
 
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index a01662d..c2362a6 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -50,6 +50,7 @@
 #ifdef __ANDROID__
 #  undef HAVE_FACCESSAT
 #endif
+#include "iscygpty.h"
 
 #include <stdio.h>                // ctermid()
 #include <stdlib.h>               // system()
@@ -350,6 +351,32 @@ corresponding Unix manual entries for more information on calls.");
 #    define HAVE_CWAIT      1
 #    define HAVE_FSYNC      1
 #    define fsync _commit
+#  elif defined(__MINGW32__)	/* GCC for windows hosts */
+/* getlogin is detected by configure on mingw-w64 */
+#    undef HAVE_GETLOGIN
+/* opendir is detected by configure on mingw-w64, and for some reason
+things don't work as expected. For example, os.listdir always returns
+the cwd's directory listing instead of the one specified. By 
+un-defining, this, os.listdir will use the one which uses native
+windows API. */
+#    undef HAVE_OPENDIR
+/*#    define HAVE_GETCWD     1 - detected by configure*/
+#    define HAVE_GETPPID    1
+#    define HAVE_GETLOGIN   1
+#    define HAVE_SPAWNV     1
+#    define HAVE_WSPAWNV    1
+#    define HAVE_WEXECV     1
+/*#    define HAVE_EXECV	     1 - detected by configure*/
+#    define HAVE_PIPE	     1
+#    define HAVE_POPEN	     1
+#    define HAVE_SYSTEM	   1
+#    define HAVE_CWAIT      1
+#    define HAVE_FSYNC      1
+#    define fsync _commit
+#    include <winioctl.h>
+#    ifndef _MAX_ENV
+#      define _MAX_ENV	32767
+#    endif
 #  endif  /* _MSC_VER */
 #endif  /* ! __WATCOMC__ || __QNX__ */
 
@@ -428,7 +455,7 @@ extern char        *ctermid_r(char *);
 #  endif
 #endif
 
-#ifdef _MSC_VER
+#ifdef MS_WINDOWS
 #  ifdef HAVE_DIRECT_H
 #    include <direct.h>
 #  endif
@@ -439,7 +466,7 @@ extern char        *ctermid_r(char *);
 #    include <process.h>
 #  endif
 #  include <malloc.h>
-#endif /* _MSC_VER */
+#endif /* MS_WINDOWS */
 
 #ifndef MAXPATHLEN
 #  if defined(PATH_MAX) && PATH_MAX > 1024
@@ -1593,9 +1620,9 @@ win32_get_reparse_tag(HANDLE reparse_point_handle, ULONG *reparse_tag)
 ** man environ(7).
 */
 #include <crt_externs.h>
-#elif !defined(_MSC_VER) && (!defined(__WATCOMC__) || defined(__QNX__) || defined(__VXWORKS__))
+#elif !defined(MS_WINDOWS) && (!defined(__WATCOMC__) || defined(__QNX__) || defined(__VXWORKS__))
 extern char **environ;
-#endif /* !_MSC_VER */
+#endif /* !MS_WINDOWS */
 
 static PyObject *
 convertenviron(void)
@@ -3815,6 +3842,7 @@ posix_getcwd(int use_bytes)
         return PyErr_SetFromWindowsErr(0);
     }
 
+    Py_NormalizeSepsW(wbuf2);
     PyObject *resobj = PyUnicode_FromWideChar(wbuf2, len);
     if (wbuf2 != wbuf) {
         PyMem_RawFree(wbuf2);
@@ -4419,6 +4447,7 @@ os__getfinalpathname_impl(PyObject *module, path_t *path)
         target_path = tmp;
     }
 
+    Py_NormalizeSepsW(target_path);
     result = PyUnicode_FromWideChar(target_path, result_length);
     if (result && path->narrow) {
         Py_SETREF(result, PyUnicode_EncodeFSDefault(result));
@@ -5467,7 +5496,7 @@ os_utime_impl(PyObject *module, path_t *path, PyObject *times, PyObject *ns,
 /*[clinic end generated code: output=cfcac69d027b82cf input=2fbd62a2f228f8f4]*/
 {
 #ifdef MS_WINDOWS
-    HANDLE hFile;
+    HANDLE hFile = 0;
     FILETIME atime, mtime;
 #else
     int result;
@@ -10194,7 +10223,7 @@ os_isatty_impl(PyObject *module, int fd)
     int return_value;
     Py_BEGIN_ALLOW_THREADS
     _Py_BEGIN_SUPPRESS_IPH
-    return_value = isatty(fd);
+    return_value = isatty(fd) || is_cygpty(fd);
     _Py_END_SUPPRESS_IPH
     Py_END_ALLOW_THREADS
     return return_value;
@@ -14682,7 +14711,7 @@ os__add_dll_directory_impl(PyObject *module, path_t *path)
        loaded. */
     Py_BEGIN_ALLOW_THREADS
     if (!(hKernel32 = GetModuleHandleW(L"kernel32")) ||
-        !(AddDllDirectory = (PAddDllDirectory)GetProcAddress(
+        !(AddDllDirectory = (PAddDllDirectory)(void *)GetProcAddress(
             hKernel32, "AddDllDirectory")) ||
         !(cookie = (*AddDllDirectory)(path->wide))) {
         err = GetLastError();
@@ -14732,7 +14761,7 @@ os__remove_dll_directory_impl(PyObject *module, PyObject *cookie)
        loaded. */
     Py_BEGIN_ALLOW_THREADS
     if (!(hKernel32 = GetModuleHandleW(L"kernel32")) ||
-        !(RemoveDllDirectory = (PRemoveDllDirectory)GetProcAddress(
+        !(RemoveDllDirectory = (PRemoveDllDirectory)(void *)GetProcAddress(
             hKernel32, "RemoveDllDirectory")) ||
         !(*RemoveDllDirectory)(cookieValue)) {
         err = GetLastError();
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 4eea928..6be3582 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -146,9 +146,9 @@ seq2set(PyObject *seq, fd_set *set, pylist fd2obj[FD_SETSIZE + 1])
         v = PyObject_AsFileDescriptor( o );
         if (v == -1) goto finally;
 
-#if defined(_MSC_VER)
+#if defined(MS_WIN32)
         max = 0;                             /* not used for Win32 */
-#else  /* !_MSC_VER */
+#else  /* !MS_WIN32 */
         if (!_PyIsSelectable_fd(v)) {
             PyErr_SetString(PyExc_ValueError,
                         "filedescriptor out of range in select()");
@@ -156,7 +156,7 @@ seq2set(PyObject *seq, fd_set *set, pylist fd2obj[FD_SETSIZE + 1])
         }
         if (v > max)
             max = v;
-#endif /* _MSC_VER */
+#endif /* MS_WIN32 */
         FD_SET(v, set);
 
         /* add object and its file descriptor to the list */
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 65d0e10..d1bfe3d 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -274,7 +274,7 @@ shutdown(how) -- shut down traffic in one or both directions\n\
 # endif
 
 /* Macros based on the IPPROTO enum, see: https://bugs.python.org/issue29515 */
-#ifdef MS_WINDOWS
+#ifdef _MSC_VER
 #define IPPROTO_ICMP IPPROTO_ICMP
 #define IPPROTO_IGMP IPPROTO_IGMP
 #define IPPROTO_GGP IPPROTO_GGP
@@ -305,7 +305,7 @@ shutdown(how) -- shut down traffic in one or both directions\n\
 #define IPPROTO_PGM IPPROTO_PGM  // WinSock2 only
 #define IPPROTO_L2TP IPPROTO_L2TP  // WinSock2 only
 #define IPPROTO_SCTP IPPROTO_SCTP  // WinSock2 only
-#endif /* MS_WINDOWS */
+#endif /* _MSC_VER */
 
 /* Provides the IsWindows7SP1OrGreater() function */
 #include <versionhelpers.h>
@@ -404,6 +404,10 @@ remove_unusable_flags(PyObject *m)
   /* Do not include addrinfo.h for MSVC7 or greater. 'addrinfo' and
    * EAI_* constants are defined in (the already included) ws2tcpip.h.
    */
+#elif defined(__MINGW32__)
+  /* Do not include addrinfo.h as minimum supported version is
+   * _WIN32_WINNT >= WindowsXP(0x0501)
+   */
 #else
 #  include "addrinfo.h"
 #endif
diff --git a/Modules/socketmodule.h b/Modules/socketmodule.h
index 1b35b11..cff1f1d 100644
--- a/Modules/socketmodule.h
+++ b/Modules/socketmodule.h
@@ -68,8 +68,10 @@ struct SOCKADDR_BTH_REDEF {
  */
 # ifdef SIO_GET_MULTICAST_FILTER
 #  include <mstcpip.h> /* for SIO_RCVALL */
+#ifndef __MINGW32__ /* resolve by configure */
 #  define HAVE_ADDRINFO
 #  define HAVE_SOCKADDR_STORAGE
+#endif
 #  define HAVE_GETADDRINFO
 #  define HAVE_GETNAMEINFO
 #  define ENABLE_IPV6
diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index 18f9ddb..4edc2e7 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -783,7 +783,7 @@ time_strftime(PyObject *module, PyObject *args)
         return NULL;
     }
 
-#if defined(_MSC_VER) || (defined(__sun) && defined(__SVR4)) || defined(_AIX) || defined(__VXWORKS__)
+#if defined(MS_WINDOWS) || (defined(__sun) && defined(__SVR4)) || defined(_AIX) || defined(__VXWORKS__)
     if (buf.tm_year + 1900 < 1 || 9999 < buf.tm_year + 1900) {
         PyErr_SetString(PyExc_ValueError,
                         "strftime() requires year in [1; 9999]");
diff --git a/Objects/fileobject.c b/Objects/fileobject.c
index ffe55eb..1d73c09 100644
--- a/Objects/fileobject.c
+++ b/Objects/fileobject.c
@@ -3,6 +3,7 @@
 #define PY_SSIZE_T_CLEAN
 #include "Python.h"
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
+#include "iscygpty.h"
 #include "pycore_runtime.h"       // _PyRuntime
 
 #if defined(HAVE_GETC_UNLOCKED) && !defined(_Py_MEMORY_SANITIZER)
@@ -387,7 +388,7 @@ stdprinter_isatty(PyStdPrinter_Object *self, PyObject *Py_UNUSED(ignored))
     }
 
     Py_BEGIN_ALLOW_THREADS
-    res = isatty(self->fd);
+    res = isatty(self->fd) || is_cygpty(self->fd);
     Py_END_ALLOW_THREADS
 
     return PyBool_FromLong(res);
diff --git a/PC/_testconsole.c b/PC/_testconsole.c
index a830883..52aca33 100644
--- a/PC/_testconsole.c
+++ b/PC/_testconsole.c
@@ -10,7 +10,7 @@
 #ifdef MS_WINDOWS
 
 #include "pycore_fileutils.h"     // _Py_get_osfhandle()
-#include "..\modules\_io\_iomodule.h"
+#include "../Modules/_io/_iomodule.h"
 
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
@@ -108,7 +108,7 @@ _testconsole_read_output_impl(PyObject *module, PyObject *file)
     Py_RETURN_NONE;
 }
 
-#include "clinic\_testconsole.c.h"
+#include "clinic/_testconsole.c.h"
 
 PyMethodDef testconsole_methods[] = {
     _TESTCONSOLE_WRITE_INPUT_METHODDEF
diff --git a/PC/launcher.c b/PC/launcher.c
index da566a1..09ac7d9 100644
--- a/PC/launcher.c
+++ b/PC/launcher.c
@@ -155,12 +155,12 @@ static wchar_t * get_env(wchar_t * key)
 #else
 #if defined(_WINDOWS)
 
-#define PYTHON_EXECUTABLE L"pythonw.exe"
+#define PYTHON_EXECUTABLE PYTHON_EXECUTABLE_WITH_VERSION
 #define EXECUTABLEPATH_VALUE L"WindowedExecutablePath"
 
 #else
 
-#define PYTHON_EXECUTABLE L"python.exe"
+#define PYTHON_EXECUTABLE PYTHON_EXECUTABLE_WITH_VERSION
 #define EXECUTABLEPATH_VALUE L"ExecutablePath"
 
 #endif
@@ -925,7 +925,7 @@ static COMMAND path_command;
 static COMMAND * find_on_path(wchar_t * name)
 {
     wchar_t * pathext;
-    size_t    varsize;
+    size_t    requiredSize;
     wchar_t * context = NULL;
     wchar_t * extension;
     COMMAND * result = NULL;
@@ -942,18 +942,23 @@ static COMMAND * find_on_path(wchar_t * name)
     }
     else {
         /* No extension - search using registered extensions. */
-        rc = _wdupenv_s(&pathext, &varsize, L"PATHEXT");
-        if (rc == 0) {
-            extension = wcstok_s(pathext, L";", &context);
-            while (extension) {
-                len = SearchPathW(NULL, name, extension, MSGSIZE, path_command.value, NULL);
-                if (len) {
-                    result = &path_command;
-                    break;
+        _wgetenv_s(&requiredSize, NULL, 0, L"PATHEXT");
+        if (requiredSize > 0) {
+            pathext = (wchar_t *)malloc(requiredSize * sizeof(wchar_t));
+            /* No extension - search using registered extensions. */
+            rc = _wgetenv_s(&requiredSize, pathext, requiredSize, L"PATHEXT");
+            if (rc == 0) {
+                extension = wcstok_s(pathext, L";", &context);
+                while (extension) {
+                    len = SearchPathW(NULL, name, extension, MSGSIZE, path_command.value, NULL);
+                    if (len) {
+                        result = &path_command;
+                        break;
+                    }
+                    extension = wcstok_s(NULL, L";", &context);
                 }
-                extension = wcstok_s(NULL, L";", &context);
+                free(pathext);
             }
-            free(pathext);
         }
     }
     return result;
@@ -1913,7 +1918,7 @@ process(int argc, wchar_t ** argv)
         if (_wfopen_s(&f, venv_cfg_path, L"r")) {
             error(RC_BAD_VENV_CFG, L"Cannot read '%ls'", venv_cfg_path);
         }
-        cb = fread_s(buffer, sizeof(buffer), sizeof(buffer[0]),
+        cb = fread(buffer, sizeof(buffer[0]),
                      sizeof(buffer) / sizeof(buffer[0]), f);
         fclose(f);
 
diff --git a/PC/msvcrtmodule.c b/PC/msvcrtmodule.c
index 1f78d99..0f2da80 100644
--- a/PC/msvcrtmodule.c
+++ b/PC/msvcrtmodule.c
@@ -22,7 +22,9 @@
 #include <io.h>
 #include <conio.h>
 #include <sys/locking.h>
+#ifdef _DEBUG
 #include <crtdbg.h>
+#endif
 #include <windows.h>
 
 #ifdef _MSC_VER
diff --git a/PC/pylauncher.rc b/PC/pylauncher.rc
index 1186264..84b2917 100644
--- a/PC/pylauncher.rc
+++ b/PC/pylauncher.rc
@@ -12,17 +12,17 @@
 1 RT_MANIFEST "python.manifest"
 
 #if defined(PY_ICON)
-1 ICON DISCARDABLE "icons\python.ico"
+1 ICON DISCARDABLE "icons/python.ico"
 #elif defined(PYW_ICON)
-1 ICON DISCARDABLE "icons\pythonw.ico"
+1 ICON DISCARDABLE "icons/pythonw.ico"
 #else
-1 ICON DISCARDABLE "icons\launcher.ico" 
-2 ICON DISCARDABLE "icons\py.ico" 
-3 ICON DISCARDABLE "icons\pyc.ico" 
-4 ICON DISCARDABLE "icons\pyd.ico" 
-5 ICON DISCARDABLE "icons\python.ico"
-6 ICON DISCARDABLE "icons\pythonw.ico"
-7 ICON DISCARDABLE "icons\setup.ico" 
+1 ICON DISCARDABLE "icons/launcher.ico"
+2 ICON DISCARDABLE "icons/py.ico" 
+3 ICON DISCARDABLE "icons/pyc.ico" 
+4 ICON DISCARDABLE "icons/pyd.ico" 
+5 ICON DISCARDABLE "icons/python.ico"
+6 ICON DISCARDABLE "icons/pythonw.ico"
+7 ICON DISCARDABLE "icons/setup.ico" 
 #endif
 
 1 USAGE "launcher-usage.txt"
@@ -64,4 +64,4 @@ BEGIN
     BEGIN
         VALUE "Translation", 0x0, 1200
     END
-END
\ No newline at end of file
+END
diff --git a/PC/python3dll.c b/PC/python3dll.c
index 50e7a96..8b524fd 100755
--- a/PC/python3dll.c
+++ b/PC/python3dll.c
@@ -3,6 +3,7 @@
 
 /* Generated by Tools/scripts/stable_abi.py */
 
+#ifdef _MSC_VER
 #ifdef _M_IX86
 #define DECORATE "_"
 #else
@@ -13,6 +14,13 @@
     __pragma(comment(linker, "/EXPORT:" DECORATE #name "=" PYTHON_DLL_NAME "." #name))
 #define EXPORT_DATA(name) \
     __pragma(comment(linker, "/EXPORT:" DECORATE #name "=" PYTHON_DLL_NAME "." #name ",DATA"))
+#else
+// XXX: Why do we need the .dll extension and no DECORATE compared to the MSVC case?
+#define EXPORT_FUNC(name) \
+    asm(".section .drectve\n\t.ascii \" -export:" #name "=\\\"" PYTHON_DLL_NAME "." #name "\\\" \"");
+#define EXPORT_DATA(name) \
+    asm(".section .drectve\n\t.ascii \" -export:" #name "=\\\"" PYTHON_DLL_NAME "." #name "\\\",DATA \"");
+#endif
 
 EXPORT_FUNC(_Py_BuildValue_SizeT)
 EXPORT_FUNC(_Py_CheckRecursiveCall)
diff --git a/PC/python_exe.rc b/PC/python_exe.rc
index c3d3bff..dde0e53 100644
--- a/PC/python_exe.rc
+++ b/PC/python_exe.rc
@@ -12,7 +12,7 @@
 // current versions of Windows.
 1 RT_MANIFEST "python.manifest"
 
-1 ICON DISCARDABLE "icons\python.ico" 
+1 ICON DISCARDABLE "icons/python.ico"
 
 
 /////////////////////////////////////////////////////////////////////////////
diff --git a/PC/pythonw_exe.rc b/PC/pythonw_exe.rc
index 38570b7..7ce1043 100644
--- a/PC/pythonw_exe.rc
+++ b/PC/pythonw_exe.rc
@@ -12,7 +12,7 @@
 // current versions of Windows.
 1 RT_MANIFEST "python.manifest"
 
-1 ICON DISCARDABLE "icons\pythonw.ico" 
+1 ICON DISCARDABLE "icons/pythonw.ico"
 
 
 /////////////////////////////////////////////////////////////////////////////
diff --git a/PC/winreg.c b/PC/winreg.c
index f668cf3..08548a7 100644
--- a/PC/winreg.c
+++ b/PC/winreg.c
@@ -18,6 +18,25 @@
 #include "structmember.h"         // PyMemberDef
 #include <windows.h>
 
+#ifndef SIZEOF_HKEY
+/* used only here */
+#if defined(MS_WIN64)
+#  define SIZEOF_HKEY 8
+#elif defined(MS_WIN32)
+#  define SIZEOF_HKEY 4
+#else
+#  error "SIZEOF_HKEY is not defined"
+#endif
+#endif
+
+#ifndef REG_LEGAL_CHANGE_FILTER
+#define REG_LEGAL_CHANGE_FILTER        (\
+          REG_NOTIFY_CHANGE_NAME       |\
+          REG_NOTIFY_CHANGE_ATTRIBUTES |\
+          REG_NOTIFY_CHANGE_LAST_SET   |\
+          REG_NOTIFY_CHANGE_SECURITY   )
+#endif
+
 static BOOL PyHKEY_AsHKEY(PyObject *ob, HKEY *pRes, BOOL bNoneOK);
 static BOOL clinic_HKEY_converter(PyObject *ob, void *p);
 static PyObject *PyHKEY_FromHKEY(HKEY h);
@@ -806,6 +825,7 @@ Reg2Py(BYTE *retDataBuf, DWORD retDataSize, DWORD typ)
         case REG_BINARY:
         /* ALSO handle ALL unknown data types here.  Even if we can't
            support it natively, we should handle the bits. */
+           /* fallthrough */
         default:
             if (retDataSize == 0) {
                 Py_INCREF(Py_None);
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index e20bd53..c035b6b 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1,6 +1,7 @@
 /* Built-in functions */
 
 #include "Python.h"
+#include "iscygpty.h"
 #include <ctype.h>
 #include "pycore_ast.h"           // _PyAST_Validate()
 #include "pycore_call.h"          // _PyObject_CallNoArgs()
@@ -2135,7 +2136,7 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
         Py_DECREF(tmp);
         if (fd < 0 && PyErr_Occurred())
             return NULL;
-        tty = fd == fileno(stdin) && isatty(fd);
+        tty = fd == fileno(stdin) && (isatty(fd) || is_cygpty(fd));
     }
     if (tty) {
         tmp = PyObject_CallMethodNoArgs(fout, &_Py_ID(fileno));
@@ -2148,7 +2149,7 @@ builtin_input_impl(PyObject *module, PyObject *prompt)
             Py_DECREF(tmp);
             if (fd < 0 && PyErr_Occurred())
                 return NULL;
-            tty = fd == fileno(stdout) && isatty(fd);
+            tty = fd == fileno(stdout) && (isatty(fd) || is_cygpty(fd));
         }
     }
 
diff --git a/Python/dynamic_annotations.c b/Python/dynamic_annotations.c
index 7febaa0..70d5b3d 100644
--- a/Python/dynamic_annotations.c
+++ b/Python/dynamic_annotations.c
@@ -27,7 +27,7 @@
  * Author: Kostya Serebryany
  */
 
-#ifdef _MSC_VER
+#ifdef MS_WINDOWS
 # include <windows.h>
 #endif
 
diff --git a/Python/dynload_win.c b/Python/dynload_win.c
index 5dc4095..fcb7321 100644
--- a/Python/dynload_win.c
+++ b/Python/dynload_win.c
@@ -4,6 +4,7 @@
 #include "Python.h"
 #include "pycore_fileutils.h"     // _Py_add_relfile()
 #include "pycore_pystate.h"       // _PyInterpreterState_GET()
+#include "pycore_initconfig.h"
 
 #ifdef HAVE_DIRECT_H
 #include <direct.h>
@@ -170,8 +171,7 @@ static char *GetPythonImport (HINSTANCE hModule)
    Return whether the DLL was found.
 */
 extern HMODULE PyWin_DLLhModule;
-static int
-_Py_CheckPython3(void)
+int _Py_CheckPython3(void)
 {
     static int python3_checked = 0;
     static HANDLE hPython3;
@@ -224,7 +224,21 @@ dl_funcptr _PyImport_FindSharedFuncptrWindows(const char *prefix,
     dl_funcptr p;
     char funcname[258], *import_python;
 
-    _Py_CheckPython3();
+    int use_legacy = 0;
+    DWORD load_library_flags = 0;
+
+    _Py_get_env_flag(1, &use_legacy, "PYTHONLEGACYWINDOWSDLLLOADING");
+
+    if (use_legacy) {
+        load_library_flags = LOAD_WITH_ALTERED_SEARCH_PATH;
+    } else {
+        load_library_flags = LOAD_LIBRARY_SEARCH_DEFAULT_DIRS |
+                              LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR;
+    }
+
+#ifdef _MSC_VER
+    _Py_CheckPython3(); 
+#endif
 
 #if USE_UNICODE_WCHAR_CACHE
     const wchar_t *wpathname = _PyUnicode_AsUnicode(pathname);
@@ -248,9 +262,7 @@ dl_funcptr _PyImport_FindSharedFuncptrWindows(const char *prefix,
            AddDllDirectory function. We add SEARCH_DLL_LOAD_DIR to
            ensure DLLs adjacent to the PYD are preferred. */
         Py_BEGIN_ALLOW_THREADS
-        hDLL = LoadLibraryExW(wpathname, NULL,
-                              LOAD_LIBRARY_SEARCH_DEFAULT_DIRS |
-                              LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR);
+        hDLL = LoadLibraryExW(wpathname, NULL, load_library_flags);
         Py_END_ALLOW_THREADS
 #if !USE_UNICODE_WCHAR_CACHE
         PyMem_Free(wpathname);
diff --git a/Python/fileutils.c b/Python/fileutils.c
index c86ed40..e459255 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -1,4 +1,5 @@
 #include "Python.h"
+#include "iscygpty.h"
 #include "pycore_fileutils.h"     // fileutils definitions
 #include "pycore_runtime.h"       // _PyRuntime
 #include "osdefs.h"               // SEP
@@ -71,7 +72,7 @@ _Py_device_encoding(int fd)
     int valid;
     Py_BEGIN_ALLOW_THREADS
     _Py_BEGIN_SUPPRESS_IPH
-    valid = isatty(fd);
+    valid = isatty(fd) || is_cygpty(fd);
     _Py_END_SUPPRESS_IPH
     Py_END_ALLOW_THREADS
     if (!valid)
@@ -1809,12 +1810,12 @@ _Py_write_impl(int fd, const void *buf, size_t count, int gil_held)
            depending on heap usage). */
         if (gil_held) {
             Py_BEGIN_ALLOW_THREADS
-            if (isatty(fd)) {
+            if (isatty(fd) || is_cygpty(fd)) {
                 count = 32767;
             }
             Py_END_ALLOW_THREADS
         } else {
-            if (isatty(fd)) {
+            if (isatty(fd) || is_cygpty(fd)) {
                 count = 32767;
             }
         }
@@ -2004,19 +2005,31 @@ int
 _Py_isabs(const wchar_t *path)
 {
 #ifdef MS_WINDOWS
+    // create a copy of path and replace all forward slashes with backslashes
+    // pathccskiproot does not handle forward slashes
+    wchar_t *path_copy = _wcsdup(path);
+    if (path_copy == NULL) {
+        return 0;
+    }
+    Py_NormalizeSepsPathcchW(path_copy);
+
     const wchar_t *tail;
-    HRESULT hr = PathCchSkipRoot(path, &tail);
-    if (FAILED(hr) || path == tail) {
+    HRESULT hr = PathCchSkipRoot(path_copy, &tail);
+    if (FAILED(hr) || path_copy == tail) {
+        free(path_copy);
         return 0;
     }
-    if (tail == &path[1] && (path[0] == SEP || path[0] == ALTSEP)) {
+    if (tail == &path_copy[1] && (path_copy[0] == SEP || path_copy[0] == ALTSEP)) {
         // Exclude paths with leading SEP
+        free(path_copy);
         return 0;
     }
-    if (tail == &path[2] && path[1] == L':') {
+    if (tail == &path_copy[2] && path_copy[1] == L':') {
         // Exclude drive-relative paths (e.g. C:filename.ext)
+        free(path_copy);
         return 0;
     }
+    free(path_copy);
     return 1;
 #else
     return (path[0] == SEP);
@@ -2049,7 +2062,11 @@ _Py_abspath(const wchar_t *path, wchar_t **abspath_p)
     }
 
 #ifdef MS_WINDOWS
-    return _PyOS_getfullpathname(path, abspath_p);
+    if (_PyOS_getfullpathname(path, abspath_p) < 0){
+        return -1;
+    }
+    *abspath_p = _Py_normpath(*abspath_p, -1);
+    return 0;
 #else
     wchar_t cwd[MAXPATHLEN + 1];
     cwd[Py_ARRAY_LENGTH(cwd) - 1] = 0;
@@ -2093,6 +2110,8 @@ join_relfile(wchar_t *buffer, size_t bufsize,
              const wchar_t *dirname, const wchar_t *relfile)
 {
 #ifdef MS_WINDOWS
+    Py_NormalizeSepsPathcchW(dirname);
+    Py_NormalizeSepsPathcchW(relfile);
     if (FAILED(PathCchCombineEx(buffer, bufsize, dirname, relfile,
         PATHCCH_ALLOW_LONG_PATHS))) {
         return -1;
@@ -2195,11 +2214,16 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
     wchar_t *minP2 = path;  // the beginning of the destination range
     wchar_t lastC = L'\0';  // the last ljusted character, p2[-1] in most cases
 
+    const wchar_t sep = Py_GetSepW(NULL);
+#ifdef ALTSEP
+    const wchar_t altsep = Py_GetAltSepW(NULL);
+#endif
+
 #define IS_END(x) (pEnd ? (x) == pEnd : !*(x))
 #ifdef ALTSEP
-#define IS_SEP(x) (*(x) == SEP || *(x) == ALTSEP)
+#define IS_SEP(x) (*(x) == sep || *(x) == altsep)
 #else
-#define IS_SEP(x) (*(x) == SEP)
+#define IS_SEP(x) (*(x) == sep)
 #endif
 #define SEP_OR_END(x) (IS_SEP(x) || IS_END(x))
 
@@ -2210,7 +2234,7 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
             path++;
         }
         p1 = p2 = minP2 = path;
-        lastC = SEP;
+        lastC = sep;
     }
 #ifdef MS_WINDOWS
     // Skip past drive segment and update minP2
@@ -2224,13 +2248,13 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
     // and network paths, including the first segment.
     else if (IS_SEP(&p1[0]) && IS_SEP(&p1[1])) {
         int sepCount = 2;
-        *p2++ = SEP;
-        *p2++ = SEP;
+        *p2++ = sep;
+        *p2++ = sep;
         p1 += 2;
         for (; !IS_END(p1) && sepCount; ++p1) {
             if (IS_SEP(p1)) {
                 --sepCount;
-                *p2++ = lastC = SEP;
+                *p2++ = lastC = sep;
             } else {
                 *p2++ = lastC = *p1;
             }
@@ -2243,7 +2267,7 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
         *p2++ = *p1++;
         *p2++ = *p1++;
         minP2 = p2 - 1;  // Absolute path has SEP at minP2
-        lastC = SEP;
+        lastC = sep;
     }
 #endif /* MS_WINDOWS */
 
@@ -2251,18 +2275,18 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
     for (; !IS_END(p1); ++p1) {
         wchar_t c = *p1;
 #ifdef ALTSEP
-        if (c == ALTSEP) {
-            c = SEP;
+        if (c == altsep) {
+            c = sep;
         }
 #endif
-        if (lastC == SEP) {
+        if (lastC == sep) {
             if (c == L'.') {
                 int sep_at_1 = SEP_OR_END(&p1[1]);
                 int sep_at_2 = !sep_at_1 && SEP_OR_END(&p1[2]);
                 if (sep_at_2 && p1[1] == L'.') {
                     wchar_t *p3 = p2;
-                    while (p3 != minP2 && *--p3 == SEP) { }
-                    while (p3 != minP2 && *(p3 - 1) != SEP) { --p3; }
+                    while (p3 != minP2 && *--p3 == sep) { }
+                    while (p3 != minP2 && *(p3 - 1) != sep) { --p3; }
                     if (p2 == minP2
                         || (p3[0] == L'.' && p3[1] == L'.' && IS_SEP(&p3[2])))
                     {
@@ -2271,7 +2295,7 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
                         *p2++ = L'.';
                         *p2++ = L'.';
                         lastC = L'.';
-                    } else if (p3[0] == SEP) {
+                    } else if (p3[0] == sep) {
                         // Absolute path, so absorb segment
                         p2 = p3 + 1;
                     } else {
@@ -2282,7 +2306,7 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
                 } else {
                     *p2++ = lastC = c;
                 }
-            } else if (c == SEP) {
+            } else if (c == sep) {
             } else {
                 *p2++ = lastC = c;
             }
@@ -2292,7 +2316,7 @@ _Py_normpath_and_size(wchar_t *path, Py_ssize_t size, Py_ssize_t *normsize)
     }
     *p2 = L'\0';
     if (p2 != minP2) {
-        while (--p2 != minP2 && *p2 == SEP) {
+        while (--p2 != minP2 && *p2 == sep) {
             *p2 = L'\0';
         }
     } else {
diff --git a/Python/frozenmain.c b/Python/frozenmain.c
index 8743e08..c6f5f19 100644
--- a/Python/frozenmain.c
+++ b/Python/frozenmain.c
@@ -3,6 +3,7 @@
 #include "Python.h"
 #include "pycore_runtime.h"  // _PyRuntime_Initialize()
 #include <locale.h>
+#include "iscygpty.h"
 
 #ifdef MS_WINDOWS
 extern void PyWinFreeze_ExeInit(void);
@@ -71,7 +72,7 @@ Py_FrozenMain(int argc, char **argv)
         sts = 0;
     }
 
-    if (inspect && isatty((int)fileno(stdin))) {
+    if (inspect && (isatty((int)fileno(stdin)) || is_cygpty((int)fileno(stdin))))
         sts = PyRun_AnyFile(stdin, "<stdin>") != 0;
     }
 
diff --git a/Python/getcompiler.c b/Python/getcompiler.c
index a5d2623..4b0b9b3 100644
--- a/Python/getcompiler.c
+++ b/Python/getcompiler.c
@@ -7,10 +7,40 @@
 
 // Note the __clang__ conditional has to come before the __GNUC__ one because
 // clang pretends to be GCC.
-#if defined(__clang__)
+#if defined(__clang__) && !defined(_WIN32)
 #define COMPILER "[Clang " __clang_version__ "]"
 #elif defined(__GNUC__)
-#define COMPILER "[GCC " __VERSION__ "]"
+/* To not break compatibility with things that determine
+   CPU arch by calling get_build_version in msvccompiler.py
+   (such as NumPy) add "32 bit" or "64 bit (AMD64)" on Windows
+   and also use a space as a separator rather than a newline. */
+#if defined(_WIN32)
+#define COMP_SEP " "
+#if defined(__x86_64__)
+#define ARCH_SUFFIX " 64 bit (AMD64)"
+#elif defined(__aarch64__)
+#define ARCH_SUFFIX " 64 bit (ARM64)"
+#elif defined(__arm__)
+#define ARCH_SUFFIX " 32 bit (ARM)"
+#else
+#define ARCH_SUFFIX " 32 bit"
+#endif
+#else
+#define COMP_SEP "\n"
+#define ARCH_SUFFIX ""
+#endif
+#if defined(__clang__)
+#define str(x) #x
+#define xstr(x) str(x)
+#define COMPILER COMP_SEP "[GCC Clang " xstr(__clang_major__) "." \
+        xstr(__clang_minor__) "." xstr(__clang_patchlevel__) ARCH_SUFFIX "]"
+#else
+#if defined(_UCRT)
+#define COMPILER COMP_SEP "[GCC UCRT " __VERSION__ ARCH_SUFFIX "]"
+#else
+#define COMPILER COMP_SEP "[GCC " __VERSION__ ARCH_SUFFIX "]"
+#endif
+#endif
 // Generic fallbacks.
 #elif defined(__cplusplus)
 #define COMPILER "[C++]"
diff --git a/Python/initconfig.c b/Python/initconfig.c
index d81cbaf..c54d238 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -176,7 +176,7 @@ static const char usage_envvars[] =
 "PYTHONVERBOSE           : trace import statements (-v)\n"
 "PYTHONWARNINGS=arg      : warning control (-W arg)\n";
 
-#if defined(MS_WINDOWS)
+#if defined(_MSC_VER)
 #  define PYTHONHOMEHELP "<prefix>\\python{major}{minor}"
 #else
 #  define PYTHONHOMEHELP "<prefix>/lib/pythonX.X"
diff --git a/Python/iscygpty.c b/Python/iscygpty.c
new file mode 100755
index 0000000..722f88f
--- /dev/null
+++ b/Python/iscygpty.c
@@ -0,0 +1,185 @@
+/*
+ * iscygpty.c -- part of ptycheck
+ * https://github.com/k-takata/ptycheck
+ *
+ * Copyright (c) 2015-2017 K.Takata
+ *
+ * You can redistribute it and/or modify it under the terms of either
+ * the MIT license (as described below) or the Vim license.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifdef _WIN32
+
+#include <ctype.h>
+#include <io.h>
+#include <wchar.h>
+#include <windows.h>
+
+#ifdef USE_FILEEXTD
+/* VC 7.1 or earlier doesn't support SAL. */
+# if !defined(_MSC_VER) || (_MSC_VER < 1400)
+#  define __out
+#  define __in
+#  define __in_opt
+# endif
+/* Win32 FileID API Library:
+ * http://www.microsoft.com/en-us/download/details.aspx?id=22599
+ * Needed for WinXP. */
+# include <fileextd.h>
+#else /* USE_FILEEXTD */
+/* VC 8 or earlier. */
+# if defined(_MSC_VER) && (_MSC_VER < 1500)
+#  ifdef ENABLE_STUB_IMPL
+#   define STUB_IMPL
+#  else
+#   error "Win32 FileID API Library is required for VC2005 or earlier."
+#  endif
+# endif
+#endif /* USE_FILEEXTD */
+
+
+#include "iscygpty.h"
+
+//#define USE_DYNFILEID
+#ifdef USE_DYNFILEID
+typedef BOOL (WINAPI *pfnGetFileInformationByHandleEx)(
+		HANDLE                    hFile,
+		FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
+		LPVOID                    lpFileInformation,
+		DWORD                     dwBufferSize
+);
+static pfnGetFileInformationByHandleEx pGetFileInformationByHandleEx = NULL;
+
+# ifndef USE_FILEEXTD
+static BOOL WINAPI stub_GetFileInformationByHandleEx(
+		HANDLE                    hFile,
+		FILE_INFO_BY_HANDLE_CLASS FileInformationClass,
+		LPVOID                    lpFileInformation,
+		DWORD                     dwBufferSize
+		)
+{
+	return FALSE;
+}
+# endif
+
+static void setup_fileid_api(void)
+{
+	if (pGetFileInformationByHandleEx != NULL) {
+		return;
+	}
+	pGetFileInformationByHandleEx = (pfnGetFileInformationByHandleEx)
+		GetProcAddress(GetModuleHandle(TEXT("kernel32.dll")),
+				"GetFileInformationByHandleEx");
+	if (pGetFileInformationByHandleEx == NULL) {
+# ifdef USE_FILEEXTD
+		pGetFileInformationByHandleEx = GetFileInformationByHandleEx;
+# else
+		pGetFileInformationByHandleEx = stub_GetFileInformationByHandleEx;
+# endif
+	}
+}
+#else
+# define pGetFileInformationByHandleEx	GetFileInformationByHandleEx
+# define setup_fileid_api()
+#endif
+
+
+#define is_wprefix(s, prefix) \
+	(wcsncmp((s), (prefix), sizeof(prefix) / sizeof(WCHAR) - 1) == 0)
+
+/* Check if the fd is a cygwin/msys's pty. */
+int is_cygpty(int fd)
+{
+#ifdef STUB_IMPL
+	return 0;
+#else
+	HANDLE h;
+	int size = sizeof(FILE_NAME_INFO) + sizeof(WCHAR) * (MAX_PATH - 1);
+	FILE_NAME_INFO *nameinfo;
+	WCHAR *p = NULL;
+
+	setup_fileid_api();
+
+	h = (HANDLE) _get_osfhandle(fd);
+	if (h == INVALID_HANDLE_VALUE) {
+		return 0;
+	}
+	/* Cygwin/msys's pty is a pipe. */
+	if (GetFileType(h) != FILE_TYPE_PIPE) {
+		return 0;
+	}
+	nameinfo = malloc(size + sizeof(WCHAR));
+	if (nameinfo == NULL) {
+		return 0;
+	}
+	/* Check the name of the pipe:
+	 * '\{cygwin,msys}-XXXXXXXXXXXXXXXX-ptyN-{from,to}-master' */
+	if (pGetFileInformationByHandleEx(h, FileNameInfo, nameinfo, size)) {
+		nameinfo->FileName[nameinfo->FileNameLength / sizeof(WCHAR)] = L'\0';
+		p = nameinfo->FileName;
+		if (is_wprefix(p, L"\\cygwin-")) {		/* Cygwin */
+			p += 8;
+		} else if (is_wprefix(p, L"\\msys-")) {	/* MSYS and MSYS2 */
+			p += 6;
+		} else {
+			p = NULL;
+		}
+		if (p != NULL) {
+			while (*p && isxdigit(*p))	/* Skip 16-digit hexadecimal. */
+				++p;
+			if (is_wprefix(p, L"-pty")) {
+				p += 4;
+			} else {
+				p = NULL;
+			}
+		}
+		if (p != NULL) {
+			while (*p && isdigit(*p))	/* Skip pty number. */
+				++p;
+			if (is_wprefix(p, L"-from-master")) {
+				//p += 12;
+			} else if (is_wprefix(p, L"-to-master")) {
+				//p += 10;
+			} else {
+				p = NULL;
+			}
+		}
+	}
+	free(nameinfo);
+	return (p != NULL);
+#endif /* STUB_IMPL */
+}
+
+/* Check if at least one cygwin/msys pty is used. */
+int is_cygpty_used(void)
+{
+	int fd, ret = 0;
+
+	for (fd = 0; fd < 3; fd++) {
+		ret |= is_cygpty(fd);
+	}
+	return ret;
+}
+
+#endif /* _WIN32 */
+
+/* vim: set ts=4 sw=4: */
diff --git a/Python/pathconfig.c b/Python/pathconfig.c
index be0f97c..7eb9006 100644
--- a/Python/pathconfig.c
+++ b/Python/pathconfig.c
@@ -2,7 +2,7 @@
 
 #include "Python.h"
 #include "marshal.h"              // PyMarshal_ReadObjectFromString
-#include "osdefs.h"               // DELIM
+#include "osdefs.h"               // DELIM, SEP
 #include "pycore_initconfig.h"
 #include "pycore_fileutils.h"
 #include "pycore_pathconfig.h"
@@ -18,6 +18,158 @@
 extern "C" {
 #endif
 
+#ifdef __MINGW32__
+#define wcstok  wcstok_s
+#include <windows.h>
+#endif
+
+static int
+Py_StartsWithA(const char * str, const char * prefix)
+{
+    while(*prefix)
+    {
+        if(*prefix++ != *str++)
+            return 0;
+    }
+
+    return 1;
+}
+
+static int
+Py_StartsWithW(const wchar_t * str, const wchar_t * prefix)
+{
+    while(*prefix)
+    {
+        if(*prefix++ != *str++)
+            return 0;
+    }
+
+    return 1;
+}
+
+char
+Py_GetSepA(const char *name)
+{
+    static char sep = '\0';
+#ifdef _WIN32
+    /* https://msdn.microsoft.com/en-gb/library/windows/desktop/aa365247%28v=vs.85%29.aspx
+     * The "\\?\" prefix .. indicate that the path should be passed to the system with minimal
+     * modification, which means that you cannot use forward slashes to represent path separators
+     */
+    if (name != NULL && Py_StartsWithA(name, "\\\\?\\") != 0)
+    {
+        return '\\';
+    }
+#endif
+    if (sep != '\0')
+        return sep;
+#if defined(__MINGW32__)
+    char* msystem = getenv("MSYSTEM");
+    if (msystem != NULL && strcmp(msystem, "") != 0)
+        sep = '/';
+    else
+        sep = '\\';
+#else
+    sep = SEP;
+#endif
+    return sep;
+}
+
+static char
+Py_GetAltSepA(const char *name)
+{
+    char sep = Py_GetSepA(name);
+    if (sep == '/')
+        return '\\';
+    return '/';
+}
+
+void
+Py_NormalizeSepsA(char *name)
+{
+    assert(name != NULL);
+    char sep = Py_GetSepA(name);
+    char altsep = Py_GetAltSepA(name);
+    char* seps;
+    if (name[0] != '\0' && name[1] == ':') {
+        name[0] = toupper(name[0]);
+    }
+    seps = strchr(name, altsep);
+    while(seps) {
+        *seps = sep;
+        seps = strchr(seps, altsep);
+    }
+}
+
+wchar_t
+Py_GetSepW(const wchar_t *name)
+{
+    static wchar_t sep = L'\0';
+#ifdef _WIN32
+    /* https://msdn.microsoft.com/en-gb/library/windows/desktop/aa365247%28v=vs.85%29.aspx
+     * The "\\?\" prefix .. indicate that the path should be passed to the system with minimal
+     * modification, which means that you cannot use forward slashes to represent path separators
+     */
+    if (name != NULL && Py_StartsWithW(name, L"\\\\?\\") != 0)
+    {
+        return L'\\';
+    }
+#endif
+    if (sep != L'\0')
+        return sep;
+#if defined(__MINGW32__)
+    char* msystem = getenv("MSYSTEM");
+    if (msystem != NULL && strcmp(msystem, "") != 0)
+        sep = L'/';
+    else
+        sep = L'\\';
+#else
+    sep = SEP;
+#endif
+    return sep;
+}
+
+wchar_t
+Py_GetAltSepW(const wchar_t *name)
+{
+    char sep = Py_GetSepW(name);
+    if (sep == L'/')
+        return L'\\';
+    return L'/';
+}
+
+void
+Py_NormalizeSepsW(wchar_t *name)
+{
+    assert(name != NULL);
+    wchar_t sep = Py_GetSepW(name);
+    wchar_t altsep = Py_GetAltSepW(name);
+    wchar_t* seps;
+    if (name[0] != L'\0' && name[1] == L':') {
+        name[0] = towupper(name[0]);
+    }
+    seps = wcschr(name, altsep);
+    while(seps) {
+        *seps = sep;
+        seps = wcschr(seps, altsep);
+    }
+}
+
+void
+Py_NormalizeSepsPathcchW(wchar_t *name)
+{
+#ifdef MS_WINDOWS
+    assert(name != NULL);
+    wchar_t sep = '\\';
+    wchar_t altsep = '/';
+    wchar_t* seps;
+    seps = wcschr(name, altsep);
+    while(seps) {
+        *seps = sep;
+        seps = wcschr(seps, altsep);
+    }
+#endif
+}
 
 /* External interface */
 
@@ -317,6 +469,7 @@ _Py_SetProgramFullPath(const wchar_t *program_full_path)
     if (has_value && _Py_path_config.program_full_path == NULL) {
         path_out_of_memory(__func__);
     }
+    Py_NormalizeSepsW(_Py_path_config.program_name);
 }
 
 
@@ -509,7 +662,7 @@ _PyPathConfig_ComputeSysPath0(const PyWideStringList *argv, PyObject **path0_p)
     }
 #endif /* All others */
 
-    PyObject *path0_obj = PyUnicode_FromWideChar(path0, n);
+    PyObject *path0_obj = PyUnicode_FromWideChar(_Py_normpath(path0, -1), n);
     if (path0_obj == NULL) {
         return -1;
     }
diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c
index 9248e97..1d53e12 100644
--- a/Python/pylifecycle.c
+++ b/Python/pylifecycle.c
@@ -31,6 +31,7 @@
 
 extern void _PyIO_Fini(void);
 
+#include "iscygpty.h"
 #include <locale.h>               // setlocale()
 #include <stdlib.h>               // getenv()
 
@@ -2954,7 +2955,7 @@ Py_Exit(int sts)
 int
 Py_FdIsInteractive(FILE *fp, const char *filename)
 {
-    if (isatty((int)fileno(fp)))
+    if (isatty((int)fileno(fp)) || is_cygpty((int)fileno(fp)))
         return 1;
     if (!Py_InteractiveFlag)
         return 0;
@@ -2967,7 +2968,7 @@ Py_FdIsInteractive(FILE *fp, const char *filename)
 int
 _Py_FdIsInteractive(FILE *fp, PyObject *filename)
 {
-    if (isatty((int)fileno(fp))) {
+    if (isatty((int)fileno(fp)) || is_cygpty((int)fileno(fp))) {
         return 1;
     }
     if (!Py_InteractiveFlag) {
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 8bab703..fed0adb 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -43,7 +43,7 @@ Data members:
 #include <windows.h>
 #endif /* MS_WINDOWS */
 
-#ifdef MS_COREDLL
+#if defined(MS_WINDOWS) && defined(Py_ENABLE_SHARED)
 extern void *PyWin_DLLhModule;
 /* A string loaded from the DLL at startup: */
 extern const char *PyWin_DLLVersionString;
@@ -2923,7 +2923,7 @@ _PySys_InitCore(PyThreadState *tstate, PyObject *sysdict)
     SET_SYS_FROM_STRING("byteorder", "little");
 #endif
 
-#ifdef MS_COREDLL
+#if defined(MS_WINDOWS) && defined(Py_ENABLE_SHARED)
     SET_SYS("dllhandle", PyLong_FromVoidPtr(PyWin_DLLhModule));
     SET_SYS_FROM_STRING("winver", PyWin_DLLVersionString);
 #endif
diff --git a/Python/thread_nt.h b/Python/thread_nt.h
index 084bd58..f8a6765 100644
--- a/Python/thread_nt.h
+++ b/Python/thread_nt.h
@@ -360,8 +360,9 @@ PyThread_release_lock(PyThread_type_lock aLock)
 {
     dprintf(("%lu: PyThread_release_lock(%p) called\n", PyThread_get_thread_ident(),aLock));
 
-    if (!(aLock && LeaveNonRecursiveMutex((PNRMUTEX) aLock)))
+    if (!(aLock && LeaveNonRecursiveMutex((PNRMUTEX) aLock))) {
         dprintf(("%lu: Could not PyThread_release_lock(%p) error: %ld\n", PyThread_get_thread_ident(), aLock, GetLastError()));
+    }
 }
 
 /* minimum/maximum thread stack sizes supported */
diff --git a/Python/traceback.c b/Python/traceback.c
index 7f47349..23fda62 100644
--- a/Python/traceback.c
+++ b/Python/traceback.c
@@ -323,7 +323,7 @@ _Py_FindSourceFile(PyObject *filename, char* namebuf, size_t namelen, PyObject *
     filepath = PyBytes_AS_STRING(filebytes);
 
     /* Search tail of filename in sys.path before giving up */
-    tail = strrchr(filepath, SEP);
+    tail = strrchr(filepath, Py_GetSepA(filepath));
     if (tail == NULL)
         tail = filepath;
     else
diff --git a/configure.ac b/configure.ac
index 1c25abd..5cf7085 100644
--- a/configure.ac
+++ b/configure.ac
@@ -202,9 +202,11 @@ AC_SUBST([FREEZE_MODULE])
 AC_SUBST([FREEZE_MODULE_DEPS])
 AC_SUBST([PYTHON_FOR_BUILD_DEPS])
 
+NATIVE_PYTHON_SEARCH_PATH_MINGW=`echo $host | grep -Eq 'mingw*' && echo "$MINGW_PREFIX/bin" || echo $PATH`
 AC_CHECK_PROGS([PYTHON_FOR_REGEN],
   [python$PACKAGE_VERSION python3.10 python3.9 python3.8 python3.7 python3.6 python3 python],
-  [python3])
+  [python3],
+  [$NATIVE_PYTHON_SEARCH_PATH_MINGW])
 AC_SUBST(PYTHON_FOR_REGEN)
 
 AC_MSG_CHECKING([Python for regen version])
@@ -545,6 +547,9 @@ then
 	*-*-cygwin*)
 		ac_sys_system=Cygwin
 		;;
+	*-*-mingw*)
+		ac_sys_system=MINGW
+		;;
 	*-*-vxworks*)
 	    ac_sys_system=VxWorks
 	    ;;
@@ -580,6 +585,7 @@ then
 	linux*) MACHDEP="linux";;
 	cygwin*) MACHDEP="cygwin";;
 	darwin*) MACHDEP="darwin";;
+	mingw*) MACHDEP="win32";;
 	'')	MACHDEP="unknown";;
     esac
 fi
@@ -605,6 +611,9 @@ if test "$cross_compiling" = yes; then
 		;;
 	wasm32-*-* | wasm64-*-*)
 		_host_cpu=$host_cpu
+    ;;
+	*-*-mingw*)
+		_host_cpu=
 		;;
 	*)
 		# for now, limit cross builds to known configurations
@@ -612,6 +621,14 @@ if test "$cross_compiling" = yes; then
 		AC_MSG_ERROR([cross build not supported for $host])
 	esac
 	_PYTHON_HOST_PLATFORM="$MACHDEP${_host_cpu:+-$_host_cpu}"
+
+	case "$host_os" in
+	mingw*)
+	# As sys.platform() return 'win32' to build python and extantions
+	# we will use 'mingw' (in setup.py and etc.)
+	_PYTHON_HOST_PLATFORM=mingw
+	;;
+	esac
 fi
 
 # Some systems cannot stand _XOPEN_SOURCE being defined at all; they
@@ -723,6 +740,65 @@ then
   AC_DEFINE(_INCLUDE__STDC_A1_SOURCE, 1, Define to include mbstate_t for mbrtowc)
 fi
 
+# On 'semi-native' build systems (MSYS*/Cygwin targeting MinGW-w64)
+# _sysconfigdata.py will contain paths that are correct only in the
+# build environment. This means external modules will fail to build
+# without setting up the same env and also that the build of Python
+# itself will fail as the paths are not correct for the host tools.
+#
+# To work around these issues a set of _b2h variables are created:
+# prefix_b2h, srcdir_b2h, abs_srcdir_b2h
+# and abs_builddir_b2h
+# .. where b2h stands for build to host. sysconfig.py replaces path
+# prefixes matching the non-b2h versions with the b2h equivalents.
+#
+# (note this assumes the host compilers are native and *not* cross
+#  - in the 'semi-native' scenario only that is.)
+
+AC_DEFUN([ABS_PATH_HOST],
+[$1=$(cd $$2 && pwd)
+  case $build_os in
+    mingw*)
+      case $host_os in
+        mingw*) $1=$(cd $$2 && pwd -W) ;;
+        *) ;;
+      esac
+      ;;
+    cygwin*)
+      case $host_os in
+        mingw*) $1=$(cygpath -w -m $$2) ;;
+        *) ;;
+      esac
+      ;;
+  esac
+AC_SUBST([$1])
+])
+
+AC_MSG_CHECKING(absolute host location of prefix)
+ABS_PATH_HOST([prefix_b2h],[prefix])
+AC_MSG_RESULT([$prefix_b2h])
+
+AC_MSG_CHECKING(absolute host location of srcdir)
+ABS_PATH_HOST([srcdir_b2h],[srcdir])
+AC_MSG_RESULT([$srcdir_b2h])
+
+AC_MSG_CHECKING(absolute host location of abs_srcdir)
+ABS_PATH_HOST([abs_srcdir_b2h],[srcdir])
+AC_MSG_RESULT([$abs_srcdir_b2h])
+
+my_builddir=.
+AC_MSG_CHECKING(Absolute host location of abs_builddir)
+ABS_PATH_HOST([abs_builddir_b2h],[my_builddir])
+AC_MSG_RESULT([$abs_builddir_b2h])
+
+AC_MSG_CHECKING([for init system calls])
+AC_SUBST(INITSYS)
+case $host in
+  *-*-mingw*)	INITSYS=nt;;
+  *)		INITSYS=posix;;
+esac
+AC_MSG_RESULT([$INITSYS])
+
 # Record the configure-time value of MACOSX_DEPLOYMENT_TARGET,
 # it may influence the way we can build extensions, so distutils
 # needs to check it
@@ -1163,6 +1239,28 @@ AC_CACHE_CHECK([for -Wl,--no-as-needed], [ac_cv_wl_no_as_needed], [
 ])
 AC_SUBST(NO_AS_NEEDED)
 
+# initialize default configuration
+py_config=
+case $host in
+  *-*-mingw*) py_config=mingw ;;
+esac
+if test -n "$py_config" ; then
+  AC_MSG_NOTICE([loading configure defaults from .../Misc/config_$py_config"])
+  . "$srcdir/Misc/config_$py_config"
+fi
+
+# initialize defaults for cross-builds
+if test "$cross_compiling" = yes; then
+  py_config=$host_os
+  case $py_config in
+    mingw32*) py_config=mingw32 ;;
+  esac
+  if test -f "$srcdir/Misc/cross_$py_config" ; then
+    AC_MSG_NOTICE([loading cross defaults from .../Misc/cross_$py_config"])
+    . "$srcdir/Misc/cross_$py_config"
+  fi
+fi
+
 AC_MSG_CHECKING([for the Android API level])
 cat > conftest.c <<EOF
 #ifdef __ANDROID__
@@ -1275,6 +1373,7 @@ AC_ARG_WITH([suffix],
     [Emscripten/browser*], [EXEEXT=.js],
     [Emscripten/node*], [EXEEXT=.js],
     [WASI/*], [EXEEXT=.wasm],
+    [MINGW*], [EXEEXT=.exe],
     [EXEEXT=]
   )
 ])
@@ -1298,6 +1397,10 @@ else
 fi
 rmdir CaseSensitiveTestDir
 
+AS_CASE([$ac_sys_system],
+  [MINGW], [BUILDEXEEXT=".exe"]
+)
+
 case $ac_sys_system in
 hp*|HP*)
     case $CC in
@@ -1475,6 +1578,11 @@ if test $enable_shared = "yes"; then
           LDLIBRARY='libpython$(LDVERSION).dll.a'
           DLLLIBRARY='libpython$(LDVERSION).dll'
           ;;
+    MINGW*)
+          LDLIBRARY='libpython$(LDVERSION).dll.a'
+          DLLLIBRARY='libpython$(LDVERSION).dll'
+          BLDLIBRARY='-L. -lpython$(LDVERSION)'
+          ;;
     SunOS*)
 	  LDLIBRARY='libpython$(LDVERSION).so'
 	  BLDLIBRARY='-Wl,-R,$(LIBDIR) -L. -lpython$(LDVERSION)'
@@ -1525,6 +1633,9 @@ else # shared is disabled
           BLDLIBRARY='$(LIBRARY)'
           LDLIBRARY='libpython$(LDVERSION).dll.a'
           ;;
+    MINGW*)
+          LDLIBRARY='libpython$(LDVERSION).a'
+          ;;
   esac
 fi
 
@@ -1618,6 +1729,10 @@ AC_SUBST(LINK_PYTHON_OBJS)
 AC_SUBST(AR)
 AC_CHECK_TOOLS(AR, ar aal, ar)
 
+# windres program
+AC_SUBST(WINDRES)
+AC_CHECK_TOOL(WINDRES, windres)
+
 # tweak ARFLAGS only if the user didn't set it on the command line
 AC_SUBST(ARFLAGS)
 if test -z "$ARFLAGS"
@@ -2498,6 +2613,53 @@ then
 	BASECFLAGS="$BASECFLAGS $ac_arch_flags"
 fi
 
+dnl NOTE:
+dnl - GCC 4.4+ for mingw* require and use posix threads(pthreads-w32)
+dnl - Host may contain installed pthreads-w32.
+dnl - On windows platform only NT-thread model is supported. 
+dnl To avoid miss detection scipt first will check for NT-thread model
+dnl and if is not found will try to detect build options for pthread
+dnl model. Autodetection could be overiden if variable with_nt_threads
+dnl is set in "Site Configuration" (see autoconf manual).
+dnl If NT-thread model is enabled script skips some checks that
+dnl impact build process. When a new functionality is added, developers
+dnl are responsible to update configure script to avoid thread models
+dnl to be mixed.
+
+AC_MSG_CHECKING([for --with-nt-threads])
+AC_ARG_WITH(nt-threads,
+            AS_HELP_STRING([--with-nt-threads], [build with windows threads (default is system-dependent)]),
+[
+	case $withval in
+	no)	with_nt_threads=no;;
+	yes)	with_nt_threads=yes;;
+	*)	with_nt_threads=yes;;
+	esac
+], [
+	case $host in
+		*-*-mingw*) with_nt_threads=yes;;
+		*) with_nt_threads=no;;
+	esac
+])
+AC_MSG_RESULT([$with_nt_threads])
+
+if test $with_nt_threads = yes ; then
+AC_MSG_CHECKING([whether linking with nt-threads work])
+AC_LINK_IFELSE([
+    AC_LANG_PROGRAM([[#include <process.h>]],[[_beginthread(0, 0, 0);]])
+  ],
+  [AC_MSG_RESULT([yes])],
+  [AC_MSG_ERROR([failed to link with nt-threads])])
+fi
+
+if test $with_nt_threads = yes ; then
+  dnl temporary default flag to avoid additional pthread checks
+  dnl and initilize other ac..thread flags to no
+  ac_cv_pthread_is_default=no
+  ac_cv_kthread=no
+  ac_cv_pthread=no
+  dnl ac_cv_kpthread is set to no if default is yes (see below)
+else
 # On some compilers, pthreads are available without further options
 # (e.g. MacOS X). On some of these systems, the compiler will not
 # complain if unaccepted options are passed (e.g. gcc on Mac OS X).
@@ -2609,6 +2771,8 @@ int main(void){
 CC="$ac_save_cc"])
 fi
 
+fi
+
 # If we have set a CC compiler flag for thread support then
 # check if it works for CXX, too.
 ac_cv_cxx_thread=no
@@ -2629,6 +2793,10 @@ elif test "$ac_cv_pthread" = "yes"
 then
   CXX="$CXX -pthread"
   ac_cv_cxx_thread=yes
+elif test $with_nt_threads = yes
+then
+  dnl set to always to skip extra pthread check below
+  ac_cv_cxx_thread=always
 fi
 
 if test $ac_cv_cxx_thread = yes
@@ -2663,11 +2831,11 @@ AC_DEFINE(STDC_HEADERS, 1, [Define to 1 if you have the ANSI C header files.])
 
 # checks for header files
 AC_CHECK_HEADERS([ \
-  alloca.h asm/types.h bluetooth.h conio.h crypt.h direct.h dlfcn.h endian.h errno.h fcntl.h grp.h \
+  alloca.h asm/types.h bluetooth.h conio.h crypt.h direct.h endian.h errno.h fcntl.h grp.h \
   ieeefp.h io.h langinfo.h libintl.h libutil.h linux/auxvec.h sys/auxv.h linux/memfd.h \
   linux/random.h linux/soundcard.h \
-  linux/tipc.h linux/wait.h netdb.h netinet/in.h netpacket/packet.h poll.h process.h pthread.h pty.h \
-  sched.h setjmp.h shadow.h signal.h spawn.h stropts.h sys/audioio.h sys/bsdtty.h sys/devpoll.h \
+  linux/tipc.h linux/wait.h netdb.h netinet/in.h netpacket/packet.h poll.h process.h pty.h \
+  setjmp.h shadow.h signal.h spawn.h stropts.h sys/audioio.h sys/bsdtty.h sys/devpoll.h \
   sys/endian.h sys/epoll.h sys/event.h sys/eventfd.h sys/file.h sys/ioctl.h sys/kern_control.h \
   sys/loadavg.h sys/lock.h sys/memfd.h sys/mkdev.h sys/mman.h sys/modem.h sys/param.h sys/poll.h \
   sys/random.h sys/resource.h sys/select.h sys/sendfile.h sys/socket.h sys/soundcard.h sys/stat.h \
@@ -2675,9 +2843,24 @@ AC_CHECK_HEADERS([ \
   sys/types.h sys/uio.h sys/un.h sys/utsname.h sys/wait.h sys/xattr.h sysexits.h syslog.h \
   termios.h util.h utime.h utmp.h \
 ])
+
+case $host in
+  *-*-mingw*) ;;
+  *) AC_CHECK_HEADERS([dlfcn.h]);;
+esac
+
+
 AC_HEADER_DIRENT
 AC_HEADER_MAJOR
 
+# If using nt threads, don't look for pthread.h or thread.h
+if test "x$with_nt_threads" = xno ; then
+AC_HEADER_STDC
+AC_CHECK_HEADERS(pthread.h sched.h thread.h)
+AC_HEADER_DIRENT
+AC_HEADER_MAJOR
+fi
+
 # bluetooth/bluetooth.h has been known to not compile with -std=c99.
 # http://permalink.gmane.org/gmane.linux.bluez.kernel/22294
 SAVE_CFLAGS=$CFLAGS
@@ -2852,6 +3035,10 @@ dnl LFS does not work with Emscripten 3.1
 AS_CASE([$ac_sys_system],
   [Emscripten], [have_largefile_support="no"]
 )
+dnl Activate on windows platforms (32&64-bit) where off_t(4) < fpos_t(8)
+AS_CASE([$ac_sys_system],
+  [MINGW], [have_largefile_support="yes"]
+)
 AS_VAR_IF([have_largefile_support], [yes], [
   AC_DEFINE(HAVE_LARGEFILE_SUPPORT, 1,
   [Defined to enable large file support when an off_t is bigger than a long
@@ -2882,6 +3069,10 @@ elif test "$ac_cv_pthread" = "yes"
 then CC="$CC -pthread"
 fi
 
+if test $with_nt_threads = yes ; then
+  dnl skip check for pthread_t if NT-thread model is enabled
+  ac_cv_have_pthread_t=skip
+else
 AC_CACHE_CHECK([for pthread_t], [ac_cv_have_pthread_t], [
 AC_COMPILE_IFELSE([
   AC_LANG_PROGRAM([[#include <pthread.h>]], [[pthread_t x; x = *(pthread_t*)0;]])
@@ -2913,7 +3104,7 @@ AS_VAR_IF([ac_cv_pthread_key_t_is_arithmetic_type], [yes], [
     AC_DEFINE(PTHREAD_KEY_T_IS_COMPATIBLE_WITH_INT, 1,
               [Define if pthread_key_t is compatible with int.])
 ])
-
+fi
 CC="$ac_save_cc"
 
 AC_SUBST(OTHER_LIBTOOL_OPT)
@@ -3089,6 +3280,9 @@ if test -z "$SHLIB_SUFFIX"; then
 	CYGWIN*)   SHLIB_SUFFIX=.dll;;
 	*)	   SHLIB_SUFFIX=.so;;
 	esac
+	case $host_os in
+	mingw*)    SHLIB_SUFFIX=.pyd;;
+	esac
 fi
 AC_MSG_RESULT($SHLIB_SUFFIX)
 
@@ -3218,6 +3412,10 @@ then
 	CYGWIN*)
 		LDSHARED="gcc -shared -Wl,--enable-auto-image-base"
 		LDCXXSHARED="g++ -shared -Wl,--enable-auto-image-base";;
+  MINGW*)
+    LDSHARED='$(CC) -shared -Wl,--enable-auto-image-base'
+    LDCXXSHARED='$(CXX) -shared -Wl,--enable-auto-image-base'
+    ;;
 	*)	LDSHARED="ld";;
 	esac
 fi
@@ -3341,6 +3539,11 @@ then
 	VxWorks*)
 		LINKFORSHARED='-Wl,-export-dynamic';;
 	esac
+	case $host in
+	*-*-mingw*)
+		# for https://bugs.python.org/issue40458 on MINGW
+		LINKFORSHARED="-Wl,--stack,2000000";;
+	esac
 fi
 AC_MSG_RESULT($LINKFORSHARED)
 
@@ -3385,7 +3588,12 @@ AC_MSG_RESULT($SHLIBS)
 
 # checks for libraries
 AC_CHECK_LIB(sendfile, sendfile)
-AC_CHECK_LIB(dl, dlopen)	# Dynamic linking for SunOS/Solaris and SYSV
+
+case $host in
+  *-*-mingw*) ;;
+  *) AC_CHECK_LIB(dl, dlopen) ;;	# Dynamic linking for SunOS/Solaris and SYSV
+esac
+
 AC_CHECK_LIB(dld, shl_load)	# Dynamic linking for HP-UX
 
 
@@ -3448,16 +3656,30 @@ AS_VAR_IF([have_uuid], [missing], [
 
 AS_VAR_IF([have_uuid], [missing], [have_uuid=no])
 
+if test $with_nt_threads = yes ; then
+  dnl do not search for sem_init if NT-thread model is enabled
+  :
+else
 # 'Real Time' functions on Solaris
 # posix4 on Solaris 2.6
 # pthread (first!) on Linux
 AC_SEARCH_LIBS(sem_init, pthread rt posix4)
+fi
 
 # check if we need libintl for locale functions
+case $host in
+  *-*-mingw*)
+  dnl Native windows build don't use libintl (see _localemodule.c).
+  dnl Also we don't like setup.py to add "intl" library to the list
+  dnl when build _locale module.
+  ;;
+  *)
 AC_CHECK_LIB(intl, textdomain,
 	[AC_DEFINE(WITH_LIBINTL, 1,
 	[Define to 1 if libintl is needed for locale functions.])
         LIBS="-lintl $LIBS"])
+  ;;
+esac
 
 # checks for system dependent C++ extensions support
 case "$ac_sys_system" in
@@ -3645,7 +3867,7 @@ else
 fi
 
 if test "$with_system_ffi" = "yes" && test -n "$PKG_CONFIG"; then
-    LIBFFI_INCLUDEDIR="`"$PKG_CONFIG" libffi --cflags-only-I 2>/dev/null | sed -e 's/^-I//;s/ *$//'`"
+    LIBFFI_INCLUDEDIR="`"$PKG_CONFIG" libffi --cflags-only-I 2>/dev/null | sed -e 's/^-I//;s/ .*$//'`"
 else
     LIBFFI_INCLUDEDIR=""
 fi
@@ -3780,6 +4002,12 @@ AS_CASE([$ac_sys_system],
   [OSSAUDIODEV_LIBS=""]
 )
 
+dnl On MINGW, you need to link against ws2_32 and iphlpapi for sockets to work
+AS_CASE([$ac_sys_system],
+  [MINGW], [SOCKET_LIBS="-lws2_32 -liphlpapi"],
+  [SOCKET_LIBS=""]
+)
+
 dnl detect sqlite3 from Emscripten emport
 PY_CHECK_EMSCRIPTEN_PORT([LIBSQLITE3], [-sUSE_SQLITE3])
 
@@ -4042,6 +4270,18 @@ AS_VAR_IF([with_dbmliborder], [error], [
 ])
 AC_MSG_RESULT($with_dbmliborder)
 
+case $host in
+  *-*-mingw*)
+    CFLAGS_NODIST="$CFLAGS_NODIST -D_WIN32_WINNT=0x0602";;
+esac
+
+# Determine if windows modules should be used.
+AC_SUBST(USE_WIN32_MODULE)
+USE_WIN32_MODULE='#'
+case $host in
+  *-*-mingw*) USE_WIN32_MODULE=;;
+esac
+
 # Templates for things AC_DEFINEd more than once.
 # For a single AC_DEFINE, no template is needed.
 AH_TEMPLATE(_REENTRANT,
@@ -4076,6 +4316,11 @@ then
         CXX="$CXX -pthread"
     fi
     posix_threads=yes
+elif test $with_nt_threads = yes
+then
+    posix_threads=no
+    AC_DEFINE(NT_THREADS, 1,
+        [Define to 1 if you want to use native NT threads])
 else
     if test ! -z "$withval" -a -d "$withval"
     then LDFLAGS="$LDFLAGS -L$withval"
@@ -4450,11 +4695,14 @@ AC_MSG_RESULT($with_freelists)
 AC_MSG_CHECKING(for --with-c-locale-coercion)
 AC_ARG_WITH(c-locale-coercion,
             AS_HELP_STRING([--with-c-locale-coercion],
-              [enable C locale coercion to a UTF-8 based locale (default is yes)]))
+              [enable C locale coercion to a UTF-8 based locale (default is yes on Unix, no on Windows)]))
 
 if test -z "$with_c_locale_coercion"
 then
-    with_c_locale_coercion="yes"
+    case $host in
+      *-*-mingw*) with_c_locale_coercion="no";;
+      *) with_c_locale_coercion="yes";;
+    esac
 fi
 if test "$with_c_locale_coercion" != "no"
 then
@@ -4555,12 +4803,36 @@ then
 	fi
 	;;
 	esac
+	case $host in
+	*-*-mingw*)
+    DYNLOADFILE="dynload_win.o"
+    extra_machdep_objs="$extra_machdep_objs PC/dl_nt.o"
+    CFLAGS_NODIST="$CFLAGS_NODIST -DPY3_DLLNAME='L\"$DLLLIBRARY\"'"
+    case $host in
+        i686*)
+                CFLAGS_NODIST="$CFLAGS_NODIST -DMS_DLL_ID='\"${VERSION}-32\"'"
+            ;;
+        armv7*)
+                CFLAGS_NODIST="$CFLAGS_NODIST -DMS_DLL_ID='\"${VERSION}-arm32\"'"
+            ;;
+        aarch64*)
+                CFLAGS_NODIST="$CFLAGS_NODIST -DMS_DLL_ID='\"${VERSION}-arm64\"'"
+            ;;
+            *)
+                CFLAGS_NODIST="$CFLAGS_NODIST -DMS_DLL_ID='\"$VERSION\"'"
+            ;;
+      esac
+    ;;
+	esac
 fi
 AC_MSG_RESULT($DYNLOADFILE)
 if test "$DYNLOADFILE" != "dynload_stub.o"
 then
+  have_dynamic_loading=yes
 	AC_DEFINE(HAVE_DYNAMIC_LOADING, 1,
         [Defined when any dynamic module loading is enabled.])
+else
+  have_dynamic_loading=no
 fi
 
 # MACHDEP_OBJS can be set to platform-specific object files needed by Python
@@ -4580,13 +4852,22 @@ else
 fi
 
 # checks for library functions
+if test $with_nt_threads = yes ; then
+  dnl GCC(mingw) 4.4+ require and use posix threads(pthreads-w32)
+  dnl and host may contain installed pthreads-w32.
+  dnl Skip checks for some functions declared in pthreads-w32 if
+  dnl NT-thread model is enabled.
+  ac_cv_func_pthread_kill=skip
+  ac_cv_func_sem_open=skip
+  ac_cv_func_sched_setscheduler=skip
+fi
 AC_CHECK_FUNCS([ \
   accept4 alarm bind_textdomain_codeset chmod chown clock close_range confstr \
   copy_file_range ctermid dup dup3 execv explicit_bzero explicit_memset \
   faccessat fchmod fchmodat fchown fchownat fdopendir fdwalk fexecve \
   fork fork1 fpathconf fstatat ftime ftruncate futimens futimes futimesat \
   gai_strerror getegid getentropy geteuid getgid getgrgid getgrgid_r \
-  getgrnam_r getgrouplist getgroups gethostname getitimer getloadavg getlogin \
+  getgrnam_r getgrouplist getgroups getitimer getloadavg getlogin \
   getpeername getpgid getpid getppid getpriority _getpty \
   getpwent getpwnam_r getpwuid getpwuid_r getresgid getresuid getrusage getsid getspent \
   getspnam getuid getwd if_nameindex initgroups kill killpg lchown linkat \
@@ -4599,7 +4880,7 @@ AC_CHECK_FUNCS([ \
   sched_setparam sched_setscheduler sem_clockwait sem_getvalue sem_open \
   sem_timedwait sem_unlink sendfile setegid seteuid setgid sethostname \
   setitimer setlocale setpgid setpgrp setpriority setregid setresgid \
-  setresuid setreuid setsid setuid setvbuf shutdown sigaction sigaltstack \
+  setresuid setreuid setsid setuid setvbuf sigaction sigaltstack \
   sigfillset siginterrupt sigpending sigrelse sigtimedwait sigwait \
   sigwaitinfo snprintf splice strftime strlcpy strsignal symlinkat sync \
   sysconf system tcgetpgrp tcsetpgrp tempnam timegm times tmpfile \
@@ -4829,7 +5110,13 @@ PKG_CHECK_MODULES([LIBLZMA], [liblzma], [have_liblzma=yes], [
 ])
 
 dnl PY_CHECK_NETDB_FUNC(FUNCTION)
-AC_DEFUN([PY_CHECK_NETDB_FUNC], [PY_CHECK_FUNC([$1], [#include <netdb.h>])])
+AC_DEFUN([PY_CHECK_NETDB_FUNC], [PY_CHECK_FUNC([$1], [
+#ifdef _WIN32
+  #include <winsock.h>
+#else
+  #include <netdb.h>
+#endif
+])])
 
 PY_CHECK_NETDB_FUNC([hstrerror])
 dnl not available in WASI yet
@@ -4838,13 +5125,19 @@ PY_CHECK_NETDB_FUNC([getservbyport])
 PY_CHECK_NETDB_FUNC([gethostbyname])
 PY_CHECK_NETDB_FUNC([gethostbyaddr])
 PY_CHECK_NETDB_FUNC([getprotobyname])
+PY_CHECK_NETDB_FUNC([gethostname])
+PY_CHECK_NETDB_FUNC([shutdown])
 
 dnl PY_CHECK_SOCKET_FUNC(FUNCTION)
 AC_DEFUN([PY_CHECK_SOCKET_FUNC], [PY_CHECK_FUNC([$1], [
+#ifdef _WIN32
+#include <ws2tcpip.h>
+#else
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
+#endif
 ])])
 
 PY_CHECK_SOCKET_FUNC([inet_aton])
@@ -4945,6 +5238,9 @@ WITH_SAVE_ENV([
   ])
 ])
 
+case $host in
+  *-*-mingw*) ;;
+  *)
 AC_CHECK_FUNCS(clock_gettime, [], [
     AC_CHECK_LIB(rt, clock_gettime, [
         LIBS="$LIBS -lrt"
@@ -4965,6 +5261,8 @@ AC_CHECK_FUNCS(clock_settime, [], [
         AC_DEFINE(HAVE_CLOCK_SETTIME, 1)
     ])
 ])
+  ;;
+esac
 
 AC_CHECK_FUNCS(clock_nanosleep, [], [
     AC_CHECK_LIB(rt, clock_nanosleep, [
@@ -5163,18 +5461,33 @@ if test $ac_cv_header_time_altzone = yes; then
   AC_DEFINE(HAVE_ALTZONE, 1, [Define this if your time.h defines altzone.])
 fi
 
+AC_CHECK_HEADERS([ws2tcpip.h])
 AC_CACHE_CHECK([for addrinfo], [ac_cv_struct_addrinfo],
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <netdb.h>]], [[struct addrinfo a]])],
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#ifdef HAVE_WS2TCPIP_H
+#  include <ws2tcpip.h>
+#else
+#  include <netdb.h>
+#endif]],
+    [[struct addrinfo a]])],
   [ac_cv_struct_addrinfo=yes],
   [ac_cv_struct_addrinfo=no]))
 if test $ac_cv_struct_addrinfo = yes; then
-	AC_DEFINE(HAVE_ADDRINFO, 1, [struct addrinfo (netdb.h)])
+	AC_DEFINE(HAVE_ADDRINFO, 1, [struct addrinfo])
 fi
 
 AC_CACHE_CHECK([for sockaddr_storage], [ac_cv_struct_sockaddr_storage],
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-#		include <sys/types.h>
-#		include <sys/socket.h>]], [[struct sockaddr_storage s]])],
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h>
+#endif
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif]],
+    [[struct sockaddr_storage s]])],
   [ac_cv_struct_sockaddr_storage=yes],
   [ac_cv_struct_sockaddr_storage=no]))
 if test $ac_cv_struct_sockaddr_storage = yes; then
@@ -5508,6 +5821,10 @@ dnl actually works.  For FreeBSD versions <= 7.2,
 dnl the kernel module that provides POSIX semaphores
 dnl isn't loaded by default, so an attempt to call
 dnl sem_open results in a 'Signal 12' error.
+if test $with_nt_threads = yes ; then
+  dnl skip posix semaphores test if NT-thread model is enabled
+  ac_cv_posix_semaphores_enabled=no
+fi
 AC_CACHE_CHECK([whether POSIX semaphores are enabled], [ac_cv_posix_semaphores_enabled],
   AC_RUN_IFELSE([
     AC_LANG_SOURCE([
@@ -5541,6 +5858,14 @@ AS_VAR_IF([ac_cv_posix_semaphores_enabled], [no], [
 ])
 
 dnl Multiprocessing check for broken sem_getvalue
+if test $with_nt_threads = yes ; then
+  dnl Skip test if NT-thread model is enabled.
+  dnl NOTE the test case below fail for pthreads-w32 as:
+  dnl - SEM_FAILED is not defined;
+  dnl - sem_open is a stub;
+  dnl - sem_getvalue work(!).
+  ac_cv_broken_sem_getvalue=skip
+fi
 AC_CACHE_CHECK([for broken sem_getvalue], [ac_cv_broken_sem_getvalue],
   AC_RUN_IFELSE([
     AC_LANG_SOURCE([
@@ -5577,7 +5902,10 @@ AS_VAR_IF([ac_cv_broken_sem_getvalue], [yes], [
   )
 ])
 
-AC_CHECK_DECLS([RTLD_LAZY, RTLD_NOW, RTLD_GLOBAL, RTLD_LOCAL, RTLD_NODELETE, RTLD_NOLOAD, RTLD_DEEPBIND, RTLD_MEMBER], [], [], [[#include <dlfcn.h>]])
+case $host in
+  *-*-mingw*) ;;
+  *) AC_CHECK_DECLS([RTLD_LAZY, RTLD_NOW, RTLD_GLOBAL, RTLD_LOCAL, RTLD_NODELETE, RTLD_NOLOAD, RTLD_DEEPBIND, RTLD_MEMBER], [], [], [[#include <dlfcn.h>]]);;
+esac
 
 # determine what size digit to use for Python's longs
 AC_MSG_CHECKING([digit size for Python's longs])
@@ -5664,6 +5992,71 @@ esac
 # check for endianness
 AC_C_BIGENDIAN
 
+AC_SUBST(PYD_PLATFORM_TAG)
+# Special case of PYD_PLATFORM_TAG with python build with mingw. 
+# Python can with compiled with clang or gcc and linked
+# to msvcrt or ucrt. To avoid conflicts between them
+# we are selecting the extension as based on the compiler
+# and the runtime they link to
+#   gcc + x86_64 + msvcrt = cp{version number}-x86_64
+#   gcc + i686 + msvcrt = cp{version number}-i686
+#   gcc + x86_64 + ucrt = cp{version number}-x86_64-ucrt
+#   clang + x86_64 + ucrt = cp{version number}-x86_64-clang
+#   clang + i686 + ucrt = cp{version number}-i686-clang
+
+PYD_PLATFORM_TAG=""
+case $host in
+  *-*-mingw*)
+    # check if we are linking to ucrt
+    AC_MSG_CHECKING(whether linking to ucrt)
+    AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+    #include <stdio.h>
+    #ifndef _UCRT
+        #error no ucrt
+    #endif
+    int main(){ return 0; }
+    ]])],[linking_to_ucrt=yes],[linking_to_ucrt=no])
+    AC_MSG_RESULT($linking_to_ucrt)
+    ;;
+esac
+case $host_os in
+    mingw*)
+  AC_MSG_CHECKING(PYD_PLATFORM_TAG)
+  case $host in
+  i686-*-mingw*)
+    if test -n "${cc_is_clang}"; then
+      # it is CLANG32
+      PYD_PLATFORM_TAG="mingw_i686_clang"
+    else
+      if test $linking_to_ucrt = no; then
+        PYD_PLATFORM_TAG="mingw_i686"
+      else
+        PYD_PLATFORM_TAG="mingw_i686_ucrt"
+      fi
+    fi
+    ;;
+  x86_64-*-mingw*)
+    if test -n "${cc_is_clang}"; then
+      # it is CLANG64
+      PYD_PLATFORM_TAG="mingw_x86_64_clang"
+    else
+      if test $linking_to_ucrt = no; then
+        PYD_PLATFORM_TAG="mingw_x86_64"
+      else
+        PYD_PLATFORM_TAG="mingw_x86_64_ucrt"
+      fi
+    fi
+    ;;
+  aarch64-*-mingw*)
+    PYD_PLATFORM_TAG+="mingw_aarch64"
+    ;;
+  armv7-*-mingw*)
+    PYD_PLATFORM_TAG+="mingw_armv7"
+    ;;
+  esac
+  AC_MSG_RESULT($PYD_PLATFORM_TAG)
+esac
+
 # ABI version string for Python extension modules.  This appears between the
 # periods in shared library file names, e.g. foo.<SOABI>.so.  It is calculated
 # from the following attributes which affect the ABI of this Python build (in
@@ -5696,7 +6089,12 @@ if test "$Py_DEBUG" = 'true' -a "$with_trace_refs" != "yes"; then
 fi
 
 AC_SUBST(EXT_SUFFIX)
-EXT_SUFFIX=.${SOABI}${SHLIB_SUFFIX}
+VERSION_NO_DOTS=$(echo $LDVERSION | tr -d .)
+if test -n "${PYD_PLATFORM_TAG}"; then
+  EXT_SUFFIX=".cp${VERSION_NO_DOTS}-${PYD_PLATFORM_TAG}${SHLIB_SUFFIX}"
+else
+  EXT_SUFFIX=.${SOABI}${SHLIB_SUFFIX}
+fi
 
 AC_MSG_CHECKING(LDVERSION)
 LDVERSION='$(VERSION)$(ABIFLAGS)'
@@ -5704,7 +6102,7 @@ AC_MSG_RESULT($LDVERSION)
 
 # On Android and Cygwin the shared libraries must be linked with libpython.
 AC_SUBST(LIBPYTHON)
-if test -n "$ANDROID_API_LEVEL" -o "$MACHDEP" = "cygwin"; then
+if test -n "$ANDROID_API_LEVEL" -o "$MACHDEP" = "cygwin" -o "$MACHDEP" = "win32"; then
   LIBPYTHON="-lpython${VERSION}${ABIFLAGS}"
 else
   LIBPYTHON=''
@@ -6073,11 +6471,16 @@ then
   [Define if you have struct stat.st_mtimensec])
 fi
 
+if test -n "$PKG_CONFIG"; then
+    NCURSESW_INCLUDEDIR="`"$PKG_CONFIG" ncursesw --cflags-only-I 2>/dev/null | sed -e 's/^-I//;s/ .*$//'`"
+else
+    NCURSESW_INCLUDEDIR=""
+fi
+AC_SUBST(NCURSESW_INCLUDEDIR)
+
 # first curses header check
 ac_save_cppflags="$CPPFLAGS"
-if test "$cross_compiling" = no; then
-  CPPFLAGS="$CPPFLAGS -I/usr/include/ncursesw"
-fi
+CPPFLAGS="$CPPFLAGS -I$NCURSESW_INCLUDEDIR"
 
 AC_CHECK_HEADERS(curses.h ncurses.h)
 
@@ -6243,7 +6646,10 @@ fi
 
 AC_CHECK_TYPE(socklen_t,,
   AC_DEFINE(socklen_t,int,
-            [Define to `int' if <sys/socket.h> does not define.]),[
+            [Define to `int' if <sys/socket.h> or <ws2tcpip.h> does not define.]),[
+#ifdef HAVE_WS2TCPIP_H
+#include <ws2tcpip.h>
+#endif
 #ifdef HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
@@ -6333,6 +6739,27 @@ do
   THREADHEADERS="$THREADHEADERS \$(srcdir)/$h"
 done
 
+case $host in
+  *-*-mingw*)
+    dnl Required for windows builds as Objects/exceptions.c require
+    dnl "errmap.h" from $srcdir/PC.
+    dnl Note we cannot use BASECPPFLAGS as autogenerated pyconfig.h
+    dnl has to be before customized located in ../PC.
+    dnl (-I. at end is workaround for setup.py logic)
+    CPPFLAGS="-I\$(srcdir)/PC $CPPFLAGS -I."
+    ;;
+esac
+
+dnl Python interpreter main program for frozen scripts
+AC_SUBST(PYTHON_OBJS_FROZENMAIN)
+PYTHON_OBJS_FROZENMAIN="Python/frozenmain.o"
+case $host in
+  *-*-mingw*)
+    dnl 'PC/frozen_dllmain.c' - not yet
+    PYTHON_OBJS_FROZENMAIN=
+    ;;
+esac
+
 AC_SUBST(SRCDIRS)
 SRCDIRS="\
   Modules \
@@ -6354,6 +6781,10 @@ SRCDIRS="\
   Python \
   Python/frozen_modules \
   Python/deepfreeze"
+case $host in
+  *-*-mingw*) SRCDIRS="$SRCDIRS PC";;
+esac
+
 AC_MSG_CHECKING(for build directories)
 for dir in $SRCDIRS; do
     if test ! -d $dir; then
@@ -6362,6 +6793,38 @@ for dir in $SRCDIRS; do
 done
 AC_MSG_RESULT(done)
 
+# For mingw build need additional library for linking
+case $host in
+  *-*-mingw*)
+    LIBS="$LIBS -lversion -lshlwapi -lpathcch -lbcrypt"
+    AC_PROG_AWK
+    if test "$AWK" = "gawk"; then
+      awk_extra_flag="--non-decimal-data"
+    fi
+    AC_MSG_CHECKING([FIELD3])
+    FIELD3=$($AWK $awk_extra_flag '\
+      /^#define PY_RELEASE_LEVEL_/             {levels[$2]=$3}    \
+      /^#define PY_MICRO_VERSION[[:space:]]+/  {micro=$3}         \
+      /^#define PY_RELEASE_LEVEL[[:space:]]+/  {level=levels[$3]} \
+      /^#define PY_RELEASE_SERIAL[[:space:]]+/ {serial=$3}        \
+      END {print micro * 1000 + level * 10 + serial}' \
+      $srcdir/Include/patchlevel.h
+    )
+    
+    AC_MSG_RESULT([${FIELD3}])
+    RCFLAGS="$RCFLAGS -DFIELD3=$FIELD3 -O COFF"
+
+    case $host in
+      i686*)  RCFLAGS="$RCFLAGS --target=pe-i386" ;;
+      x86_64*)  RCFLAGS="$RCFLAGS --target=pe-x86-64" ;;
+      *) ;;
+    esac
+  ;;
+  *)
+  ;;
+esac
+AC_SUBST(RCFLAGS)
+
 # Availability of -O2:
 AC_CACHE_CHECK([for -O2], [ac_cv_compile_o2], [
 saved_cflags="$CFLAGS"
@@ -6971,7 +7434,6 @@ PY_STDLIB_MOD_SIMPLE([_json])
 PY_STDLIB_MOD_SIMPLE([_lsprof])
 PY_STDLIB_MOD_SIMPLE([_opcode])
 PY_STDLIB_MOD_SIMPLE([_pickle])
-PY_STDLIB_MOD_SIMPLE([_posixsubprocess])
 PY_STDLIB_MOD_SIMPLE([_queue])
 PY_STDLIB_MOD_SIMPLE([_random])
 PY_STDLIB_MOD_SIMPLE([select])
@@ -6982,7 +7444,7 @@ PY_STDLIB_MOD_SIMPLE([_zoneinfo])
 
 dnl multiprocessing modules
 PY_STDLIB_MOD([_multiprocessing],
-  [], [test "$ac_cv_func_sem_unlink" = "yes"],
+  [], [test "$ac_cv_func_sem_unlink" = "yes" -o "$MACHDEP" = "win32"],
   [-I\$(srcdir)/Modules/_multiprocessing])
 PY_STDLIB_MOD([_posixshmem],
   [], [test "$have_posix_shmem" = "yes"],
@@ -7002,11 +7464,15 @@ PY_STDLIB_MOD([fcntl],
   [], [test "$ac_cv_header_sys_ioctl_h" = "yes" -a "$ac_cv_header_fcntl_h" = "yes"],
   [], [$FCNTL_LIBS])
 PY_STDLIB_MOD([mmap],
-  [], [test "$ac_cv_header_sys_mman_h" = "yes" -a "$ac_cv_header_sys_stat_h" = "yes"])
+  [], m4_flatten([test "$ac_cv_header_sys_mman_h" = "yes"
+                    -a "$ac_cv_header_sys_stat_h" = "yes"
+                    -o "$MACHDEP" = "win32"]))
 PY_STDLIB_MOD([_socket],
   [], m4_flatten([test "$ac_cv_header_sys_socket_h" = "yes"
                     -a "$ac_cv_header_sys_types_h" = "yes"
-                    -a "$ac_cv_header_netinet_in_h" = "yes"]))
+                    -a "$ac_cv_header_netinet_in_h" = "yes"
+                    -o "$MACHDEP" = "win32"]),
+  [], [$SOCKET_LIBS])
 
 dnl platform specific extensions
 PY_STDLIB_MOD([grp], [], [test "$ac_cv_func_getgrgid" = yes -o "$ac_cv_func_getgrgid_r" = yes])
@@ -7021,6 +7487,7 @@ PY_STDLIB_MOD([_scproxy],
 PY_STDLIB_MOD([spwd], [], [test "$ac_cv_func_getspent" = yes -o "$ac_cv_func_getspnam" = yes])
 PY_STDLIB_MOD([syslog], [], [test "$ac_cv_header_syslog_h" = yes])
 PY_STDLIB_MOD([termios], [], [test "$ac_cv_header_termios_h" = yes])
+PY_STDLIB_MOD([_posixsubprocess], [], [test "$MACHDEP" != "win32"])
 
 dnl _elementtree loads libexpat via CAPI hook in pyexpat
 PY_STDLIB_MOD([pyexpat], [], [], [$LIBEXPAT_CFLAGS], [$LIBEXPAT_LDFLAGS])
@@ -7083,25 +7550,35 @@ PY_STDLIB_MOD([_lzma], [], [test "$have_liblzma" = yes],
 
 dnl OpenSSL bindings
 PY_STDLIB_MOD([_ssl], [], [test "$ac_cv_working_openssl_ssl" = yes],
-  [$OPENSSL_INCLUDES], [$OPENSSL_LDFLAGS $OPENSSL_LDFLAGS_RPATH $OPENSSL_LIBS])
+  [$OPENSSL_INCLUDES], [$OPENSSL_LDFLAGS $OPENSSL_LDFLAGS_RPATH $OPENSSL_LIBS -lws2_32])
 PY_STDLIB_MOD([_hashlib], [], [test "$ac_cv_working_openssl_hashlib" = yes],
   [$OPENSSL_INCLUDES], [$OPENSSL_LDFLAGS $OPENSSL_LDFLAGS_RPATH $LIBCRYPTO_LIBS])
 
+dnl windows specific modules
+PY_STDLIB_MOD([msvcrt], [test "$MACHDEP" = "win32"])
+PY_STDLIB_MOD([_winapi], [test "$MACHDEP" = "win32"])
+PY_STDLIB_MOD([_msi], [test "$MACHDEP" = "win32"], [], [],
+  [-lmsi -lcabinet -lrpcrt4])
+PY_STDLIB_MOD([winsound], [test "$MACHDEP" = "win32"], [], [],
+  [-lwinmm])
+PY_STDLIB_MOD([_overlapped], [test "$MACHDEP" = "win32"], [], [],
+  [-lws2_32])
+
 dnl test modules
 PY_STDLIB_MOD([_testcapi], [test "$TEST_MODULES" = yes])
 PY_STDLIB_MOD([_testclinic], [test "$TEST_MODULES" = yes])
-PY_STDLIB_MOD([_testinternalcapi], [test "$TEST_MODULES" = yes])
+PY_STDLIB_MOD([_testinternalcapi], [test "$TEST_MODULES" = yes], [], [-DPY3_DLLNAME="\"$DLLLIBRARY\""], [])
 PY_STDLIB_MOD([_testbuffer], [test "$TEST_MODULES" = yes])
-PY_STDLIB_MOD([_testimportmultiple], [test "$TEST_MODULES" = yes], [test "$ac_cv_func_dlopen" = yes])
-PY_STDLIB_MOD([_testmultiphase], [test "$TEST_MODULES" = yes], [test "$ac_cv_func_dlopen" = yes])
+PY_STDLIB_MOD([_testimportmultiple], [test "$TEST_MODULES" = yes], [test "$have_dynamic_loading" = yes])
+PY_STDLIB_MOD([_testmultiphase], [test "$TEST_MODULES" = yes], [test "$have_dynamic_loading" = yes])
 PY_STDLIB_MOD([_xxtestfuzz], [test "$TEST_MODULES" = yes])
-PY_STDLIB_MOD([_ctypes_test], [test "$TEST_MODULES" = yes], [test "$ac_cv_func_dlopen" = yes], [], [-lm])
+PY_STDLIB_MOD([_ctypes_test], [test "$TEST_MODULES" = yes], [test "$have_dynamic_loading" = yes], [], [-lm])
 
 dnl Limited API template modules.
 dnl The limited C API is not compatible with the Py_TRACE_REFS macro.
 dnl Emscripten does not support shared libraries yet.
-PY_STDLIB_MOD([xxlimited], [test "$with_trace_refs" = "no"], [test "$ac_cv_func_dlopen" = yes])
-PY_STDLIB_MOD([xxlimited_35], [test "$with_trace_refs" = "no"], [test "$ac_cv_func_dlopen" = yes])
+PY_STDLIB_MOD([xxlimited], [test "$with_trace_refs" = "no"], [test "$have_dynamic_loading" = yes])
+PY_STDLIB_MOD([xxlimited_35], [test "$with_trace_refs" = "no"], [test "$have_dynamic_loading" = yes])
 
 # substitute multiline block, must come after last PY_STDLIB_MOD()
 AC_SUBST([MODULE_BLOCK])
diff --git a/mingw_ignorefile.txt b/mingw_ignorefile.txt
new file mode 100755
index 0000000..54093f1
--- /dev/null
+++ b/mingw_ignorefile.txt
@@ -0,0 +1,42 @@
+ctypes.test.test_loading.LoaderTest.test_load_dll_with_flags
+distutils.tests.test_bdist_dumb.BuildDumbTestCase.test_simple_built
+distutils.tests.test_cygwinccompiler.CygwinCCompilerTestCase.test_get_versions
+distutils.tests.test_util.UtilTestCase.test_change_root
+test.datetimetester.TestLocalTimeDisambiguation_Fast.*
+test.datetimetester.TestLocalTimeDisambiguation_Pure.*
+test.test_cmath.CMathTests.test_specific_values
+test.test_cmd_line_script.CmdLineTest.test_consistent_sys_path_for_direct_execution
+test.test_compileall.CommandLineTestsNoSourceEpoch.*
+test.test_compileall.CommandLineTestsWithSourceEpoch.*
+test.test_compileall.CompileallTestsWithoutSourceEpoch.*
+test.test_compileall.CompileallTestsWithSourceEpoch.*
+test.test_import.ImportTests.test_dll_dependency_import
+test.test_math.MathTests.*
+test.test_ntpath.NtCommonTest.test_import
+test.test_os.StatAttributeTests.test_stat_block_device
+test.test_os.TestScandir.test_attributes
+test.test_os.UtimeTests.test_large_time
+test.test_platform.PlatformTest.test_architecture_via_symlink
+test.test_regrtest.ProgramsTestCase.test_pcbuild_rt
+test.test_regrtest.ProgramsTestCase.test_tools_buildbot_test
+test.test_site._pthFileTests.*
+test.test_site.HelperFunctionsTests.*
+test.test_site.StartupImportTests.*
+test.test_ssl.*
+test.test_strptime.CalculationTests.*
+test.test_strptime.StrptimeTests.test_weekday
+test.test_strptime.TimeRETests.test_compile
+test.test_tools.test_i18n.Test_pygettext.test_POT_Creation_Date
+test.test_venv.BasicTest.*
+test.test_venv.EnsurePipTest.*
+test.test_sysconfig.TestSysConfig.test_user_similar
+test.test_tcl.TclTest.testLoadWithUNC
+# flaky
+test.test__xxsubinterpreters.*
+test.test_asyncio.test_subprocess.SubprocessProactorTests.test_stdin_broken_pipe
+test.test_asynchat.TestAsynchat.test_line_terminator2
+test.test_asyncgen.AsyncGenAsyncioTest.test_async_gen_asyncio_gc_aclose_09
+test.test_concurrent_futures.ThreadPoolShutdownTest.test_interpreter_shutdown
+test.test_asynchat.TestNotConnected.test_disallow_negative_terminator
+test.test_logging.SysLogHandlerTest.*
+test.test_logging.IPv6SysLogHandlerTest.*
diff --git a/mingw_smoketests.py b/mingw_smoketests.py
new file mode 100755
index 0000000..ca1f652
--- /dev/null
+++ b/mingw_smoketests.py
@@ -0,0 +1,358 @@
+#!/usr/bin/env python3
+# Copyright 2017 Christoph Reiter
+#
+# Permission is hereby granted, free of charge, to any person obtaining
+# a copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish,
+# distribute, sublicense, and/or sell copies of the Software, and to
+# permit persons to whom the Software is furnished to do so, subject to
+# the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+"""The goal of this test suite is collect tests for update regressions
+and to test msys2 related modifications like for path handling.
+Feel free to extend.
+"""
+
+import os
+import unittest
+import sysconfig
+
+if os.environ.get("MSYSTEM", ""):
+    SEP = "/"
+else:
+    SEP = "\\"
+
+if sysconfig.is_python_build():
+    os.environ["PYTHONLEGACYWINDOWSDLLLOADING"] = "1"
+
+_UCRT = sysconfig.get_platform() not in ('mingw_x86_64', 'mingw_i686')
+
+
+class Tests(unittest.TestCase):
+
+    def test_zoneinfo(self):
+        # https://github.com/msys2-contrib/cpython-mingw/issues/32
+        import zoneinfo
+        self.assertTrue(any(os.path.exists(p) for p in zoneinfo.TZPATH))
+        zoneinfo.ZoneInfo("America/Sao_Paulo")
+
+    def test_userdir_path_sep(self):
+        # Make sure os.path and pathlib use the same path separators
+        from unittest import mock
+        from os.path import expanduser
+        from pathlib import Path
+
+        profiles = ["C:\\foo", "C:/foo"]
+        for profile in profiles:
+            with mock.patch.dict(os.environ, {"USERPROFILE": profile}):
+                self.assertEqual(expanduser("~"), os.path.normpath(expanduser("~")))
+                self.assertEqual(str(Path("~").expanduser()), expanduser("~"))
+                self.assertEqual(str(Path.home()), expanduser("~"))
+
+    def test_sysconfig_schemes(self):
+        # https://github.com/msys2/MINGW-packages/issues/9319
+        import sysconfig
+        from distutils.dist import Distribution
+        from distutils.command.install import install
+
+        names = ['scripts', 'purelib', 'platlib', 'data', 'include']
+        for scheme in ["nt", "nt_user"]:
+            for name in names:
+                c = install(Distribution({"name": "foobar"}))
+                c.user = (scheme == "nt_user")
+                c.finalize_options()
+                if name == "include":
+                    dist_path = os.path.dirname(getattr(c, "install_" + "headers"))
+                else:
+                    dist_path = getattr(c, "install_" + name)
+                sys_path = sysconfig.get_path(name, scheme)
+                self.assertEqual(dist_path, sys_path, (scheme, name))
+
+    def test_ctypes_find_library(self):
+        from ctypes.util import find_library
+        from ctypes import cdll
+        self.assertTrue(cdll.msvcrt)
+        if _UCRT:
+            self.assertIsNone(find_library('c'))
+        else:
+            self.assertEqual(find_library('c'), 'msvcrt.dll')
+
+    def test_ctypes_dlopen(self):
+        import ctypes
+        import sys
+        self.assertEqual(ctypes.RTLD_GLOBAL, 0)
+        self.assertEqual(ctypes.RTLD_GLOBAL,  ctypes.RTLD_LOCAL)
+        self.assertFalse(hasattr(sys, 'setdlopenflags'))
+        self.assertFalse(hasattr(sys, 'getdlopenflags'))
+        self.assertFalse([n for n in dir(os) if n.startswith("RTLD_")])
+
+    def test_time_no_unix_stuff(self):
+        import time
+        self.assertFalse([n for n in dir(time) if n.startswith("clock_")])
+        self.assertFalse([n for n in dir(time) if n.startswith("CLOCK_")])
+        self.assertFalse([n for n in dir(time) if n.startswith("pthread_")])
+        self.assertFalse(hasattr(time, 'tzset'))
+
+    def test_strftime(self):
+        import time
+        with self.assertRaises(ValueError):
+            time.strftime('%Y', (12345,) + (0,) * 8)
+
+    def test_sep(self):
+        self.assertEqual(os.sep, SEP)
+
+    def test_module_file_path(self):
+        import asyncio
+        import zlib
+        self.assertEqual(zlib.__file__, os.path.normpath(zlib.__file__))
+        self.assertEqual(asyncio.__file__, os.path.normpath(asyncio.__file__))
+
+    def test_importlib_frozen_path_sep(self):
+        import importlib._bootstrap_external
+        self.assertEqual(importlib._bootstrap_external.path_sep, SEP)
+
+    def test_os_commonpath(self):
+        self.assertEqual(
+            os.path.commonpath(
+                [os.path.join("C:", os.sep, "foo", "bar"),
+                 os.path.join("C:", os.sep, "foo")]),
+                 os.path.join("C:", os.sep, "foo"))
+
+    def test_pathlib(self):
+        import pathlib
+
+        p = pathlib.Path("foo") / pathlib.Path("foo")
+        self.assertEqual(str(p), os.path.normpath(p))
+
+    def test_modules_import(self):
+        import sqlite3
+        import ssl
+        import ctypes
+        import curses
+
+    def test_c_modules_import(self):
+        import _decimal
+
+    def test_socket_inet_ntop(self):
+        import socket
+        self.assertTrue(hasattr(socket, "inet_ntop"))
+
+    def test_socket_inet_pton(self):
+        import socket
+        self.assertTrue(hasattr(socket, "inet_pton"))
+
+    def test_multiprocessing_queue(self):
+        from multiprocessing import Queue
+        Queue(0)
+
+    #def test_socket_timout_normal_error(self):
+    #    import urllib.request
+    #    from urllib.error import URLError
+
+    #    try:
+    #        urllib.request.urlopen(
+    #            'http://localhost', timeout=0.0001).close()
+    #    except URLError:
+    #        pass
+
+    def test_threads(self):
+        from concurrent.futures import ThreadPoolExecutor
+
+        with ThreadPoolExecutor(1) as pool:
+            for res in pool.map(lambda *x: None, range(10000)):
+                pass
+
+    def test_sysconfig(self):
+        import sysconfig
+        # This should be able to execute without exceptions
+        sysconfig.get_config_vars()
+
+    def test_sqlite_enable_load_extension(self):
+        # Make sure --enable-loadable-sqlite-extensions is used
+        import sqlite3
+        self.assertTrue(sqlite3.Connection.enable_load_extension)
+
+    def test_venv_creation(self):
+        import tempfile
+        import venv
+        import subprocess
+        import shutil
+        with tempfile.TemporaryDirectory() as tmp:
+            builder = venv.EnvBuilder()
+            builder.create(tmp)
+            assert os.path.exists(os.path.join(tmp, "bin", "activate"))
+            assert os.path.exists(os.path.join(tmp, "bin", "python.exe"))
+            assert os.path.exists(os.path.join(tmp, "bin", "python3.exe"))
+            subprocess.check_call([shutil.which("bash.exe"), os.path.join(tmp, "bin", "activate")])
+
+            # This will not work in in-tree build
+            if not sysconfig.is_python_build():
+                op = subprocess.check_output(
+                    [
+                        os.path.join(tmp, "bin", "python.exe"),
+                        "-c",
+                        "print('Hello World')"
+                    ],
+                    cwd=tmp,
+                )
+                assert op.decode().strip() == "Hello World"
+
+    def test_has_mktime(self):
+        from time import mktime, gmtime
+        mktime(gmtime())
+
+    def test_platform_things(self):
+        import sys
+        import sysconfig
+        import platform
+        import importlib.machinery
+        self.assertEqual(sys.implementation.name, "cpython")
+        self.assertEqual(sys.platform, "win32")
+        self.assertTrue(sysconfig.get_platform().startswith("mingw"))
+        self.assertTrue(sysconfig.get_config_var('SOABI').startswith("cpython-"))
+        ext_suffix = sysconfig.get_config_var('EXT_SUFFIX')
+        self.assertTrue(ext_suffix.endswith(".pyd"))
+        self.assertTrue("mingw" in ext_suffix)
+        self.assertEqual(sysconfig.get_config_var('SHLIB_SUFFIX'), ".pyd")
+        ext_suffixes = importlib.machinery.EXTENSION_SUFFIXES
+        self.assertTrue(ext_suffix in ext_suffixes)
+        self.assertTrue(".pyd" in ext_suffixes)
+        if sysconfig.get_platform().startswith('mingw_i686'):
+             self.assertEqual(sys.winver, ".".join(map(str, sys.version_info[:2])) + '-32')
+        elif sysconfig.get_platform().startswith('mingw_aarch64'):
+            self.assertEqual(sys.winver, ".".join(map(str, sys.version_info[:2])) + '-arm64')
+        elif sysconfig.get_platform().startswith('mingw_armv7'):
+            self.assertEqual(sys.winver, ".".join(map(str, sys.version_info[:2])) + '-arm32')
+        else:
+            self.assertEqual(sys.winver, ".".join(map(str, sys.version_info[:2])))
+        self.assertEqual(platform.python_implementation(), "CPython")
+        self.assertEqual(platform.system(), "Windows")
+        self.assertTrue(isinstance(sys.api_version, int) and sys.api_version > 0)
+
+    def test_sys_getpath(self):
+        # everything sourced from getpath.py
+        import sys
+
+        def assertNormpath(path):
+            self.assertEqual(path, os.path.normpath(path))
+
+        assertNormpath(sys.executable)
+        assertNormpath(sys._base_executable)
+        assertNormpath(sys.prefix)
+        assertNormpath(sys.base_prefix)
+        assertNormpath(sys.exec_prefix)
+        assertNormpath(sys.base_exec_prefix)
+        assertNormpath(sys.platlibdir)
+        assertNormpath(sys._stdlib_dir)
+        for p in sys.path:
+            assertNormpath(p)
+
+    def test_site(self):
+        import site
+
+        self.assertEqual(len(site.getsitepackages()), 1)
+
+    def test_c_ext_build(self):
+        import tempfile
+        import sys
+        import subprocess
+        import textwrap
+        from pathlib import Path
+
+        with tempfile.TemporaryDirectory() as tmppro:
+            subprocess.check_call([sys.executable, "-m", "ensurepip", "--user"])
+            with Path(tmppro, "setup.py").open("w") as f:
+                f.write(
+                    textwrap.dedent(
+                        """\
+                                    from setuptools import setup, Extension
+
+                                    setup(
+                                        name='cwrapper',
+                                        version='1.0',
+                                        ext_modules=[
+                                            Extension(
+                                                'cwrapper',
+                                                sources=['cwrapper.c']),
+                                        ],
+                                    )
+                                """
+                    )
+                )
+            with Path(tmppro, "cwrapper.c").open("w") as f:
+                f.write(
+                    textwrap.dedent(
+                        """\
+                                    #include <Python.h>
+                                    static PyObject *
+                                    helloworld(PyObject *self, PyObject *args)
+                                    {
+                                        printf("Hello World\\n");
+                                        Py_RETURN_NONE;
+                                    }
+                                    static PyMethodDef
+                                    myMethods[] = {
+                                        { "helloworld", helloworld, METH_NOARGS, "Prints Hello World" },
+                                        { NULL, NULL, 0, NULL }
+                                    };
+                                    static struct PyModuleDef cwrapper = {
+                                        PyModuleDef_HEAD_INIT,
+                                        "cwrapper",
+                                        "Test Module",
+                                        -1,
+                                        myMethods
+                                    };
+
+                                    PyMODINIT_FUNC
+                                    PyInit_cwrapper(void)
+                                    {
+                                        return PyModule_Create(&cwrapper);
+                                    }
+                                """
+                    )
+                )
+            subprocess.check_call(
+                [sys.executable, "-c", "import struct"],
+            )
+            subprocess.check_call(
+                [
+                    sys.executable,
+                    "-m",
+                    "pip",
+                    "install",
+                    "wheel",
+                ],
+            )
+            subprocess.check_call(
+                [
+                    sys.executable,
+                    "-m",
+                    "pip",
+                    "install",
+                    tmppro,
+                ],
+            )
+            subprocess.check_call(
+                [sys.executable, "-c", "import cwrapper"],
+            )
+
+
+
+def suite():
+    return unittest.TestLoader().loadTestsFromName(__name__)
+
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 75f1d90..3b89b9e 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -60,7 +60,7 @@
 /* Define to 1 if you have the `acosh' function. */
 #undef HAVE_ACOSH
 
-/* struct addrinfo (netdb.h) */
+/* struct addrinfo */
 #undef HAVE_ADDRINFO
 
 /* Define to 1 if you have the `alarm' function. */
@@ -1521,6 +1521,9 @@
 /* Define if mvwdelch in curses.h is an expression. */
 #undef MVWDELCH_IS_EXPRESSION
 
+/* Define to 1 if you want to use native NT threads */
+#undef NT_THREADS
+
 /* Define to the address where bug reports for this package should be sent. */
 #undef PACKAGE_BUGREPORT
 
@@ -1836,7 +1839,7 @@
 /* Define to `unsigned int' if <sys/types.h> does not define. */
 #undef size_t
 
-/* Define to `int' if <sys/socket.h> does not define. */
+/* Define to `int' if <sys/socket.h> or <ws2tcpip.h> does not define. */
 #undef socklen_t
 
 /* Define to `int' if <sys/types.h> doesn't define. */
diff --git a/setup.py b/setup.py
index 4f122b6..e4f15d8 100644
--- a/setup.py
+++ b/setup.py
@@ -77,9 +77,24 @@ def get_platform():
     return sys.platform
 
 
+# On MSYS, os.system needs to be wrapped with sh.exe
+# as otherwise all the io redirection will fail.
+# Arguably, this could happen inside the real os.system
+# rather than this monkey patch.
+if sys.platform == "win32" and os.environ.get("MSYSTEM", ""):
+    os_system = os.system
+    def msys_system(command):
+        command_in_sh = 'sh.exe -c "%s"' % command.replace("\\", "\\\\")
+        return os_system(command_in_sh)
+    os.system = msys_system
+
+    # set PYTHONLEGACYWINDOWSDLLLOADING to 1 to load DLLs from PATH
+    # This is needed while building core extensions of Python
+    os.environ["PYTHONLEGACYWINDOWSDLLLOADING"] = "1"
+
 CROSS_COMPILING = ("_PYTHON_HOST_PLATFORM" in os.environ)
 HOST_PLATFORM = get_platform()
-MS_WINDOWS = (HOST_PLATFORM == 'win32')
+MS_WINDOWS = (HOST_PLATFORM == 'win32' or HOST_PLATFORM == 'mingw')
 CYGWIN = (HOST_PLATFORM == 'cygwin')
 MACOS = (HOST_PLATFORM == 'darwin')
 AIX = (HOST_PLATFORM.startswith('aix'))
@@ -687,7 +702,7 @@ def check_extension_import(self, ext):
     def add_multiarch_paths(self):
         # Debian/Ubuntu multiarch support.
         # https://wiki.ubuntu.com/MultiarchSpec
-        tmpfile = os.path.join(self.build_temp, 'multiarch')
+        tmpfile = os.path.join(self.build_temp, 'multiarch').replace('\\','/')
         if not os.path.exists(self.build_temp):
             os.makedirs(self.build_temp)
         ret = run_command(
@@ -712,7 +727,7 @@ def add_multiarch_paths(self):
         opt = ''
         if CROSS_COMPILING:
             opt = '-t' + sysconfig.get_config_var('HOST_GNU_TYPE')
-        tmpfile = os.path.join(self.build_temp, 'multiarch')
+        tmpfile = os.path.join(self.build_temp, 'multiarch').replace('\\','/')
         if not os.path.exists(self.build_temp):
             os.makedirs(self.build_temp)
         ret = run_command(
@@ -774,7 +789,7 @@ def add_search_path(line):
                 pass
 
     def add_cross_compiling_paths(self):
-        tmpfile = os.path.join(self.build_temp, 'ccpaths')
+        tmpfile = os.path.join(self.build_temp, 'ccpaths').replace('\\','/')
         if not os.path.exists(self.build_temp):
             os.makedirs(self.build_temp)
         # bpo-38472: With a German locale, GCC returns "gcc-Version 9.1.0
@@ -796,14 +811,25 @@ def add_cross_compiling_paths(self):
                         elif line.startswith("End of search list"):
                             in_incdirs = False
                         elif (is_gcc or is_clang) and line.startswith("LIBRARY_PATH"):
-                            for d in line.strip().split("=")[1].split(":"):
+                            for d in line.strip().split("=")[1].split(os.pathsep):
                                 d = os.path.normpath(d)
-                                if '/gcc/' not in d:
+                                if '/gcc/' not in d and '/clang/' not in d:
                                     add_dir_to_list(self.compiler.library_dirs,
                                                     d)
                         elif (is_gcc or is_clang) and in_incdirs and '/gcc/' not in line and '/clang/' not in line:
                             add_dir_to_list(self.compiler.include_dirs,
                                             line.strip())
+            if is_clang:
+                ret = run_command('%s -print-search-dirs >%s' % (CC, tmpfile))
+                if ret == 0:
+                    with open(tmpfile) as fp:
+                        for line in fp.readlines():
+                            if line.startswith("libraries:"):
+                                for d in line.strip().split("=")[1].split(os.pathsep):
+                                    d = os.path.normpath(d)
+                                    if '/gcc/' not in d and '/clang/' not in d:
+                                        add_dir_to_list(self.compiler.library_dirs,
+                                                        d)
         finally:
             os.unlink(tmpfile)
 
@@ -849,10 +875,10 @@ def configure_compiler(self):
         if not CROSS_COMPILING:
             add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
             add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')
+            self.add_multiarch_paths()
         # only change this for cross builds for 3.3, issues on Mageia
         if CROSS_COMPILING:
             self.add_cross_compiling_paths()
-        self.add_multiarch_paths()
         self.add_ldflags_cppflags()
 
     def init_inc_lib_dirs(self):
@@ -898,7 +924,7 @@ def init_inc_lib_dirs(self):
         if HOST_PLATFORM == 'hp-ux11':
             self.lib_dirs += ['/usr/lib/hpux64', '/usr/lib/hpux32']
 
-        if MACOS:
+        if MACOS or MS_WINDOWS:
             # This should work on any unixy platform ;-)
             # If the user has bothered specifying additional -I and -L flags
             # in OPT and LDFLAGS we might as well use them here.
@@ -970,11 +996,15 @@ def detect_simple_extensions(self):
         # grp(3)
         self.addext(Extension('grp', ['grpmodule.c']))
 
-        self.addext(Extension('_socket', ['socketmodule.c']))
+        self.addext(Extension(
+            '_socket', ['socketmodule.c'],
+            libraries=(['ws2_32', 'iphlpapi'] if MS_WINDOWS else None)))
         self.addext(Extension('spwd', ['spwdmodule.c']))
 
         # select(2); not on ancient System V
-        self.addext(Extension('select', ['selectmodule.c']))
+        self.addext(Extension(
+            'select', ['selectmodule.c'],
+            libraries=(['ws2_32'] if MS_WINDOWS else None)))
 
         # Memory-mapped files (also works on Win32).
         self.addext(Extension('mmap', ['mmapmodule.c']))
@@ -1033,12 +1063,15 @@ def detect_test_extensions(self):
             ['_xxtestfuzz/_xxtestfuzz.c', '_xxtestfuzz/fuzzer.c']
         ))
 
+        if MS_WINDOWS:
+            self.add(Extension('_testconsole', ['../PC/_testconsole.c']))
+
     def detect_readline_curses(self):
         # readline
         readline_termcap_library = ""
         curses_library = ""
         # Cannot use os.popen here in py3k.
-        tmpfile = os.path.join(self.build_temp, 'readline_termcap_lib')
+        tmpfile = os.path.join(self.build_temp, 'readline_termcap_lib').replace('\\','/')
         if not os.path.exists(self.build_temp):
             os.makedirs(self.build_temp)
         # Determine if readline is already linked against curses or tinfo.
@@ -1101,6 +1134,8 @@ def detect_readline_curses(self):
                 # readline package
                 if find_file('readline/rlconf.h', self.inc_dirs, []) is None:
                     do_readline = False
+        if MS_WINDOWS:
+            do_readline = False
         if do_readline:
             readline_libs = [readline_lib]
             if readline_termcap_library:
@@ -1124,8 +1159,7 @@ def detect_readline_curses(self):
         panel_library = 'panel'
         if curses_library == 'ncursesw':
             curses_defines.append(('HAVE_NCURSESW', '1'))
-            if not CROSS_COMPILING:
-                curses_includes.append('/usr/include/ncursesw')
+            curses_includes.append(sysconfig.get_config_var("NCURSESW_INCLUDEDIR"))
             # Bug 1464056: If _curses.so links with ncursesw,
             # _curses_panel.so must link with panelw.
             panel_library = 'panelw'
@@ -1209,7 +1243,7 @@ def detect_dbm_gdbm(self):
             if dbm_args:
                 dbm_order = [arg.split('=')[-1] for arg in dbm_args][-1].split(":")
             else:
-                dbm_order = "gdbm:ndbm:bdb".split(":")
+                dbm_order = []
             dbmext = None
             for cand in dbm_order:
                 if cand == "ndbm":
@@ -1282,6 +1316,19 @@ def detect_platform_specific_exts(self):
         # macOS-only, needs SystemConfiguration and CoreFoundation framework
         self.addext(Extension('_scproxy', ['_scproxy.c']))
 
+        # Windows-only modules
+        if MS_WINDOWS:
+            srcdir = sysconfig.get_config_var('srcdir')
+            pc_srcdir = os.path.abspath(os.path.join(srcdir, 'PC'))
+
+            self.addext(Extension('_msi', 
+                                [os.path.join(pc_srcdir, '_msi.c')]))
+
+            self.addext(Extension('winsound', 
+                                [os.path.join(pc_srcdir, 'winsound.c')]))
+
+            self.addext(Extension('_overlapped', ['overlapped.c']))
+
     def detect_compress_exts(self):
         # Andrew Kuchling's zlib module.
         self.addext(Extension('zlib', ['zlibmodule.c']))
@@ -1329,9 +1376,10 @@ def detect_multiprocessing(self):
         if (
             sysconfig.get_config_var('HAVE_SEM_OPEN') and not
             sysconfig.get_config_var('POSIX_SEMAPHORES_NOT_ENABLED')
-        ):
+        ) or MS_WINDOWS:
             multiprocessing_srcs.append('_multiprocessing/semaphore.c')
-        self.addext(Extension('_multiprocessing', multiprocessing_srcs))
+        self.addext(Extension('_multiprocessing', multiprocessing_srcs,
+                              libraries=(['ws2_32'] if MS_WINDOWS else None), include_dirs=["Modules/_multiprocessing"]))
         self.addext(Extension('_posixshmem', ['_multiprocessing/posixshmem.c']))
 
     def detect_uuid(self):
@@ -1414,11 +1462,16 @@ def detect_ctypes(self):
                         include_dirs=include_dirs,
                         extra_compile_args=extra_compile_args,
                         extra_link_args=extra_link_args,
-                        libraries=[],
+                        libraries=(['ole32', 'oleaut32', 'uuid'] if MS_WINDOWS else []),
+                        export_symbols=(
+                            ['DllGetClassObject PRIVATE', 'DllCanUnloadNow PRIVATE']
+                            if MS_WINDOWS else None
+                        ),
                         sources=sources)
         self.add(ext)
         # function my_sqrt() needs libm for sqrt()
-        self.addext(Extension('_ctypes_test', ['_ctypes/_ctypes_test.c']))
+        self.addext(Extension('_ctypes_test', ['_ctypes/_ctypes_test.c'],
+                              libraries=(['oleaut32'] if MS_WINDOWS else [])))
 
         ffi_inc = sysconfig.get_config_var("LIBFFI_INCLUDEDIR")
         ffi_lib = None
@@ -1568,7 +1621,7 @@ def copy_scripts(self):
             else:
                 newfilename = filename + minoronly
             log.info(f'renaming {filename} to {newfilename}')
-            os.rename(filename, newfilename)
+            os.replace(filename, newfilename)
             newoutfiles.append(newfilename)
             if filename in updated_files:
                 newupdated_files.append(newfilename)