Update Python to 3.13.3 and add support to Windows on ARM64.

README.md

@@ -65,7 +65,7 @@ https://emscripten.org/docs/building_from_source/toolchain_what_is_needed.html.
 
 ### Linux
 
-- `python`: Version 3.9.2 or above.
+- `python`: Version 3.9.2 or above. Version 3.13.3 or a newer 3.13.x is recommended.
 - `java`: For running closure compiler (optional)
 
 The emsdk pre-compiled binaries are built against Ubuntu/Focal 20.04 LTS and

emsdk

@@ -8,7 +8,10 @@
 
 # First look for python bundled in Emsdk
 if [ -z "$EMSDK_PYTHON" ]; then
-  PYTHON3="$(dirname "$0")/python/3.9.2-1_64bit/bin/python3"
+  PYTHON3="$(dirname "$0")/python/3.13.3-0_64bit/bin/python3"
+  if [ ! -f "$PYTHON3" ]; then
+    PYTHON3="$(dirname "$0")/python/3.9.2-1_64bit/bin/python3"
+  fi
   if [ -f "$PYTHON3" ]; then
     EMSDK_PYTHON="$PYTHON3"
 

emsdk.bat

@@ -7,6 +7,14 @@ setlocal
 :: When using our bundled python we never want the users
 :: PYTHONHOME or PYTHONPATH
 :: https://github.com/emscripten-core/emsdk/issues/598
+
+if exist "%~dp0python\3.13.3-0_64bit\python.exe" (
+  set EMSDK_PY="%~dp0python\3.13.3-0_64bit\python.exe"
+  set PYTHONHOME=
+  set PYTHONPATH=
+  goto end
+)
+
 if exist "%~dp0python\3.9.2-1_64bit\python.exe" (
   set EMSDK_PY="%~dp0python\3.9.2-1_64bit\python.exe"
   set PYTHONHOME=

emsdk.ps1

@@ -1,6 +1,7 @@
 $ScriptDirectory = Split-Path -parent $PSCommandPath
 
 $PythonLocations = $(
+    "python\3.13.3-0_64bit\python.exe",
     "python\3.9.2-1_64bit\python.exe",
     "python\3.9.2-nuget_64bit\python.exe"
 )

emsdk.py

@@ -143,11 +143,7 @@ def exit_with_error(msg):
 elif machine.endswith('86'):
   ARCH = 'x86'
 elif machine.startswith('aarch64') or machine.lower().startswith('arm64'):
-  if WINDOWS:
-    errlog('No support for Windows on Arm, fallback to x64')
-    ARCH = 'x86_64'
-  else:
-    ARCH = 'arm64'
+  ARCH = 'arm64'
 elif machine.startswith('arm'):
   ARCH = 'arm'
 else:
@@ -988,17 +984,16 @@ def cmake_configure(generator, build_root, src_root, build_type, extra_cmake_arg
       generator = []
 
     cmdline = ['cmake'] + generator + ['-DCMAKE_BUILD_TYPE=' + build_type, '-DPYTHON_EXECUTABLE=' + sys.executable]
-    # Target macOS 10.14 at minimum, to support widest range of Mac devices
-    # from "Early 2008" and newer:
-    # https://en.wikipedia.org/wiki/MacBook_(2006-2012)#Supported_operating_systems
-    cmdline += ['-DCMAKE_OSX_DEPLOYMENT_TARGET=10.14']
+    # Target macOS 11.0 Big Sur at minimum, to support older Mac devices.
+    # See https://en.wikipedia.org/wiki/MacOS#Hardware_compatibility for min-spec details.
+    cmdline += ['-DCMAKE_OSX_DEPLOYMENT_TARGET=11.0']
     cmdline += extra_cmake_args + [src_root]
 
     print('Running CMake: ' + str(cmdline))
 
     # Specify the deployment target also as an env. var, since some Xcode versions
     # read this instead of the CMake field.
-    os.environ['MACOSX_DEPLOYMENT_TARGET'] = '10.14'
+    os.environ['MACOSX_DEPLOYMENT_TARGET'] = '11.0'
 
     def quote_parens(x):
       if ' ' in x:

emsdk_manifest.json

@@ -192,6 +192,44 @@
     "activated_cfg": "PYTHON='%installation_dir%/bin/python3'",
     "activated_env": "EMSDK_PYTHON=%installation_dir%/bin/python3;SSL_CERT_FILE=%installation_dir%/lib/python3.9/site-packages/certifi/cacert.pem"
   },
+
+  {
+    "id": "python",
+    "version": "3.13.3",
+    "bitness": 64,
+    "arch": "x86_64",
+    "windows_url": "python-3.13.3-0-win-amd64.zip",
+    "activated_cfg": "PYTHON='%installation_dir%/python.exe'",
+    "activated_env": "EMSDK_PYTHON=%installation_dir%/python.exe"
+  },
+  {
+    "id": "python",
+    "version": "3.13.3",
+    "bitness": 64,
+    "arch": "arm64",
+    "windows_url": "python-3.13.3-0-win-arm64.zip",
+    "activated_cfg": "PYTHON='%installation_dir%/python.exe'",
+    "activated_env": "EMSDK_PYTHON=%installation_dir%/python.exe"
+  },
+  {
+    "id": "python",
+    "version": "3.13.3",
+    "bitness": 64,
+    "arch": "x86_64",
+    "macos_url": "python-3.13.3-0-macos-x86_64.tar.gz",
+    "activated_cfg": "PYTHON='%installation_dir%/bin/python3'",
+    "activated_env": "EMSDK_PYTHON=%installation_dir%/bin/python3;SSL_CERT_FILE=%installation_dir%/lib/python3.13/site-packages/certifi/cacert.pem"
+  },
+  {
+    "id": "python",
+    "version": "3.13.3",
+    "bitness": 64,
+    "arch": "arm64",
+    "macos_url": "python-3.13.3-0-macos-arm64.tar.gz",
+    "activated_cfg": "PYTHON='%installation_dir%/bin/python3'",
+    "activated_env": "EMSDK_PYTHON=%installation_dir%/bin/python3;SSL_CERT_FILE=%installation_dir%/lib/python3.13/site-packages/certifi/cacert.pem"
+  },
+
   {
     "id": "emscripten",
     "version": "tag-%tag%",
@@ -350,13 +388,13 @@
   {
     "version": "main",
     "bitness": 64,
-    "uses": ["python-3.9.2-nuget-64bit", "llvm-git-main-64bit", "node-20.18.0-64bit", "emscripten-main-64bit", "binaryen-main-64bit"],
+    "uses": ["python-3.13.3-64bit", "llvm-git-main-64bit", "node-20.18.0-64bit", "emscripten-main-64bit", "binaryen-main-64bit"],
     "os": "win"
   },
   {
     "version": "main",
     "bitness": 64,
-    "uses": ["python-3.9.2-64bit", "llvm-git-main-64bit", "node-20.18.0-64bit", "emscripten-main-64bit", "binaryen-main-64bit"],
+    "uses": ["python-3.13.3-64bit", "llvm-git-main-64bit", "node-20.18.0-64bit", "emscripten-main-64bit", "binaryen-main-64bit"],
     "os": "macos"
   },
   {
@@ -381,23 +419,23 @@
   {
     "version": "releases-%releases-tag%",
     "bitness": 64,
-    "uses": ["node-20.18.0-64bit", "python-3.9.2-64bit", "releases-%releases-tag%-64bit"],
+    "uses": ["node-20.18.0-64bit", "python-3.13.3-64bit", "releases-%releases-tag%-64bit"],
     "os": "macos",
     "arch": "x86_64",
     "custom_install_script": "emscripten_npm_install"
   },
   {
     "version": "releases-%releases-tag%",
     "bitness": 64,
-    "uses": ["node-20.18.0-64bit", "python-3.9.2-64bit", "releases-%releases-tag%-64bit"],
+    "uses": ["node-20.18.0-64bit", "python-3.13.3-64bit", "releases-%releases-tag%-64bit"],
     "os": "macos",
     "arch": "arm64",
     "custom_install_script": "emscripten_npm_install"
   },
   {
     "version": "releases-%releases-tag%",
     "bitness": 64,
-    "uses": ["node-20.18.0-64bit", "python-3.9.2-nuget-64bit", "releases-%releases-tag%-64bit"],
+    "uses": ["node-20.18.0-64bit", "python-3.13.3-64bit", "releases-%releases-tag%-64bit"],
     "os": "win",
     "custom_install_script": "emscripten_npm_install"
   }

scripts/update_python.py

@@ -8,12 +8,13 @@
 http://storage.google.com/webassembly.
 
 We only supply binaries for windows and macOS, but we do it very different ways for those two OSes.
+On Linux, we depend on the system version of python.
 
 Windows recipe:
-  1. Download the "embeddable zip file" version of python from python.org
-  2. Remove .pth file to work around https://bugs.python.org/issue34841
-  3. Download and install pywin32 in the `site-packages` directory
-  4. Re-zip and upload to storage.google.com
+  1. Download precompiled version of python from NuGet package manager,
+     either the package "python" for AMD64, or "pythonarm64" for ARM64.
+  2. Set up pip and install pywin32 and psutil via pip for emrun to work.
+  3. Re-zip and upload to storage.google.com
 
 macOS recipe:
   1. Clone cpython
@@ -32,27 +33,35 @@
 from subprocess import check_call
 from zip import unzip_cmd, zip_cmd
 
-version = '3.9.2'
+version = '3.13.3'
 major_minor_version = '.'.join(version.split('.')[:2])  # e.g. '3.9.2' -> '3.9'
-download_url = 'https://www.nuget.org/api/v2/package/python/%s' % version
 # This is not part of official Python version, but a repackaging number appended by emsdk
 # when a version of Python needs to be redownloaded.
-revision = '4'
+revision = '0'
 
-pywin32_version = '227'
-pywin32_base = 'https://github.com/mhammond/pywin32/releases/download/b%s/' % pywin32_version
+PSUTIL = 'psutil==7.0.0'
 
 upload_base = 'gs://webassembly/emscripten-releases-builds/deps/'
 
 
+# Detects whether current python interpreter architecture is ARM64 or AMD64
+# If running AMD64 python on an ARM64 Windows, this still intentionally returns AMD64
+def find_python_arch():
+    import sysconfig
+    arch = sysconfig.get_platform().lower()
+    if 'amd64' in arch:
+        return 'amd64'
+    if 'arm64' in arch:
+        return 'arm64'
+    raise f'Unknown Python sysconfig platform "{arch}" (neither AMD64 or ARM64)'
+
+
 def make_python_patch():
-    pywin32_filename = 'pywin32-%s.win-amd64-py%s.exe' % (pywin32_version, major_minor_version)
-    filename = 'python-%s-amd64.zip' % (version)
-    out_filename = 'python-%s-%s-amd64+pywin32.zip' % (version, revision)
-    if not os.path.exists(pywin32_filename):
-        url = pywin32_base + pywin32_filename
-        print('Downloading pywin32: ' + url)
-        urllib.request.urlretrieve(url, pywin32_filename)
+    python_arch = find_python_arch()
+    package_name = 'pythonarm64' if python_arch == 'arm64' else 'python'
+    download_url = f'https://www.nuget.org/api/v2/package/{package_name}/{version}'
+    filename = f'python-{version}-win-{python_arch}.zip'
+    out_filename = f'python-{version}-{revision}-win-{python_arch}.zip'
 
     if not os.path.exists(filename):
         print(f'Downloading python: {download_url} to {filename}')
@@ -62,19 +71,17 @@ def make_python_patch():
     check_call(unzip_cmd() + [os.path.abspath(filename)], cwd='python-nuget')
     os.remove(filename)
 
-    os.mkdir('pywin32')
-    rtn = subprocess.call(unzip_cmd() + [os.path.abspath(pywin32_filename)], cwd='pywin32')
-    assert rtn in [0, 1]
-
-    os.mkdir(os.path.join('python-nuget', 'lib'))
-    shutil.move(os.path.join('pywin32', 'PLATLIB'), os.path.join('python-nuget', 'toolss', 'Lib', 'site-packages'))
+    src_dir = os.path.join('python-nuget', 'tools')
+    python_exe = os.path.join(src_dir, 'python.exe')
+    check_call([python_exe, '-m', 'ensurepip', '--upgrade'])
+    check_call([python_exe, '-m', 'pip', 'install', 'pywin32==310', '--no-warn-script-location'])
+    check_call([python_exe, '-m', 'pip', 'install', PSUTIL])
 
-    check_call(zip_cmd() + [os.path.join('..', '..', out_filename), '.'], cwd='python-nuget/tools')
+    check_call(zip_cmd() + [os.path.join('..', '..', out_filename), '.'], cwd=src_dir)
     print('Created: %s' % out_filename)
 
     # cleanup if everything went fine
     shutil.rmtree('python-nuget')
-    shutil.rmtree('pywin32')
 
     if '--upload' in sys.argv:
       upload_url = upload_base + out_filename
@@ -92,7 +99,7 @@ def build_python():
         check_call(['brew', 'install', 'openssl', 'xz', 'pkg-config'])
         if platform.machine() == 'x86_64':
             prefix = '/usr/local'
-            min_macos_version = '10.11'
+            min_macos_version = '11.0'
         elif platform.machine() == 'arm64':
             prefix = '/opt/homebrew'
             min_macos_version = '11.0'
@@ -113,7 +120,9 @@ def build_python():
         osname = 'linux'
 
     src_dir = 'cpython'
-    if not os.path.exists(src_dir):
+    if os.path.exists(src_dir):
+      check_call(['git', 'fetch'], cwd=src_dir)
+    else:
       check_call(['git', 'clone', 'https://github.com/python/cpython'])
     check_call(['git', 'checkout', 'v' + version], cwd=src_dir)
 
@@ -143,7 +152,7 @@ def build_python():
 
     # Install psutil module. This is needed by emrun to track when browser
     # process quits.
-    check_call([pybin, pip, 'install', 'psutil'])
+    check_call([pybin, pip, 'install', PSUTIL])
 
     dirname = 'python-%s-%s' % (version, revision)
     if os.path.isdir(dirname):