[infra] Migrate scripts to python3

* Migrate to python3; drop python support.
* Update Windows toolchain support.
* Remove some unused methods.
* Python 2.7 is still needed on Windows.
* Update gsutil to a version that supports python3.

Fixes: #28793

TEST=Manually tested common user journeys.

Change-Id: I663a22b237a548bb82dc2e601e399e3bc3649211
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/192182
Reviewed-by: William Hesse <whesse@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>

.gn

@@ -12,3 +12,6 @@ buildconfig = "//build/config/BUILDCONFIG.gn"
 # GN build files are placed when they can not be placed directly
 # in the source tree, e.g. for third party source trees.
 secondary_source = "//build/secondary/"
+
+# Override the default script executable to always be python3.
+script_executable = "python3"

DEPS

@@ -268,8 +268,8 @@ deps = {
 
   Var("dart_root") + "/third_party/gsutil": {
       "packages": [{
-          "package": "infra/gsutil",
-          "version": "version:4.34",
+          "package": "infra/3pp/tools/gsutil",
+          "version": "version:4.58",
       }],
       "dep_type": "cipd",
   },
@@ -672,59 +672,56 @@ hooks = [
     # Pull Debian sysroot for i386 Linux
     'name': 'sysroot_i386',
     'pattern': '.',
-    'action': ['python', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
+    'action': ['python3', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch', 'i386'],
   },
   {
     # Pull Debian sysroot for amd64 Linux
     'name': 'sysroot_amd64',
     'pattern': '.',
-    'action': ['python', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
+    'action': ['python3', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch', 'amd64'],
   },
   {
     # Pull Debian sysroot for arm Linux
     'name': 'sysroot_amd64',
     'pattern': '.',
-    'action': ['python', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
+    'action': ['python3', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch', 'arm'],
   },
   {
     # Pull Debian jessie sysroot for arm64 Linux
     'name': 'sysroot_amd64',
     'pattern': '.',
-    'action': ['python', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
+    'action': ['python3', 'sdk/build/linux/sysroot_scripts/install-sysroot.py',
                '--arch', 'arm64'],
   },
   {
     'name': 'buildtools',
     'pattern': '.',
-    'action': ['python', 'sdk/tools/buildtools/update.py'],
+    'action': ['python3', 'sdk/tools/buildtools/update.py'],
   },
   {
     # Update the Windows toolchain if necessary.
     'name': 'win_toolchain',
     'pattern': '.',
-    'action': ['python', 'sdk/build/vs_toolchain.py', 'update'],
+    'action': ['python3', 'sdk/build/vs_toolchain.py', 'update'],
+    'condition': 'checkout_win'
+  },
+  {
+    "name": "7zip",
+    "pattern": ".",
+    "action": [
+      "download_from_google_storage",
+      "--no_auth",
+      "--no_resume",
+      "--bucket",
+      "dart-dependencies",
+      "--platform=win32",
+      "--extract",
+      "-s",
+      Var('dart_root') + "/third_party/7zip.tar.gz.sha1",
+    ],
+    'condition': 'checkout_win'
   },
 ]
-
-hooks_os = {
-  "win": [
-    {
-      "name": "7zip",
-      "pattern": ".",
-      "action": [
-        "download_from_google_storage",
-        "--no_auth",
-        "--no_resume",
-        "--bucket",
-        "dart-dependencies",
-        "--platform=win32",
-        "--extract",
-        "-s",
-        Var('dart_root') + "/third_party/7zip.tar.gz.sha1",
-      ],
-    },
-  ]
-}

build/config/linux/pkg-config.py

@@ -34,7 +34,7 @@
 # success. This allows us to "kind of emulate" a Linux build from other
 # platforms.
 if sys.platform.find("linux") == -1:
-    print "[[],[],[],[],[]]"
+    print("[[],[],[],[],[]]")
     sys.exit(0)
 
 
@@ -50,7 +50,7 @@ def SetConfigPath(options):
     # Compute the library path name based on the architecture.
     arch = options.arch
     if sysroot and not arch:
-        print "You must specify an architecture via -a if using a sysroot."
+        print("You must specify an architecture via -a if using a sysroot.")
         sys.exit(1)
     if arch == 'x64':
         libpath = 'lib64'
@@ -138,17 +138,17 @@ def RewritePath(path, strip_prefix, sysroot):
         [options.pkg_config, "--atleast-version=" + options.atleast_version] +
             args,
             env=os.environ):
-        print "true"
+        print("true")
     else:
-        print "false"
+        print("false")
     sys.exit(0)
 
 if options.libdir:
     try:
         libdir = subprocess.check_output(
             [options.pkg_config, "--variable=libdir"] + args, env=os.environ)
     except:
-        print "Error from pkg-config."
+        print("Error from pkg-config.")
         sys.exit(1)
     sys.stdout.write(libdir.strip())
     sys.exit(0)
@@ -163,7 +163,7 @@ def RewritePath(path, strip_prefix, sysroot):
     # to happen in practice.
     all_flags = flag_string.strip().split(' ')
 except:
-    print "Could not run pkg-config."
+    print("Could not run pkg-config.")
     sys.exit(1)
 
 sysroot = options.sysroot
@@ -199,4 +199,4 @@ def RewritePath(path, strip_prefix, sysroot):
 # Output a GN array, the first one is the cflags, the second are the libs. The
 # JSON formatter prints GN compatible lists when everything is a list of
 # strings.
-print json.dumps([includes, cflags, libs, lib_dirs, ldflags])
+print(json.dumps([includes, cflags, libs, lib_dirs, ldflags]))

build/config/linux/sysroot_ld_path.py

@@ -12,9 +12,10 @@
 import sys
 
 if len(sys.argv) != 3:
-    print "Need two arguments"
+    print("Need two arguments")
     sys.exit(1)
 
-result = subprocess.check_output([sys.argv[1], sys.argv[2]]).strip()
+result = subprocess.check_output([sys.argv[1], sys.argv[2]],
+                                 universal_newlines=True).strip()
 
-print '"' + result + '"'
+print('"' + result + '"')

build/config/mac/mac_app.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 # Copyright (c) 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

build/detect_host_arch.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -48,4 +48,4 @@ def DoMain(_):
 
 
 if __name__ == '__main__':
-    print DoMain([])
+    print(DoMain([]))

build/gn_run_binary.py

@@ -1,11 +1,11 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """Helper script for GN to run an arbitrary binary. See compiled_action.gni.
 
 Run with:
-  python gn_run_binary.py <invoker> <binary_name> [args ...]
+  python3 gn_run_binary.py <invoker> <binary_name> [args ...]
 
 Where <invoker> is either "compiled_action" or "exec_script". If it is
 "compiled_action" the script has a non-zero exit code on a failure. If it is
@@ -21,7 +21,9 @@
 # Run a command, swallowing the output unless there is an error.
 def run_command(command):
     try:
-        subprocess.check_output(command, stderr=subprocess.STDOUT)
+        subprocess.check_output(command,
+                                stderr=subprocess.STDOUT,
+                                universal_newlines=True)
         return 0
     except subprocess.CalledProcessError as e:
         return ("Command failed: " + ' '.join(command) + "\n" + "output: " +

build/linux/sysroot_scripts/install-sysroot.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -17,14 +17,12 @@
 
 import hashlib
 import json
-import platform
 import optparse
 import os
-import re
 import shutil
 import subprocess
 import sys
-import urllib2
+from urllib.request import urlopen
 
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 sys.path.append(os.path.dirname(os.path.dirname(SCRIPT_DIR)))
@@ -87,7 +85,7 @@ def main(args):
         return 0
 
     if not options.arch:
-        print 'You much specify either --arch or --running-as-hook'
+        print('You much specify either --arch or --running-as-hook')
         return 1
     InstallDefaultSysrootForArch(options.arch)
 
@@ -134,18 +132,18 @@ def InstallSysroot(target_platform, target_arch):
             if s.read() == url:
                 return
 
-    print 'Installing Debian %s %s root image: %s' % \
-        (target_platform, target_arch, sysroot)
+    print('Installing Debian %s %s root image: %s' % \
+        (target_platform, target_arch, sysroot))
     if os.path.isdir(sysroot):
         shutil.rmtree(sysroot)
     os.mkdir(sysroot)
     tarball = os.path.join(sysroot, tarball_filename)
-    print 'Downloading %s' % url
+    print('Downloading %s' % url)
     sys.stdout.flush()
     sys.stderr.flush()
     for _ in range(3):
         try:
-            response = urllib2.urlopen(url)
+            response = urlopen(url)
             with open(tarball, "wb") as f:
                 f.write(response.read())
             break

build/mac/change_mach_o_flags.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.

build/mac/find_sdk.py

@@ -1,12 +1,12 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """Prints the lowest locally available SDK version greater than or equal to a
 given minimum sdk version to standard output.
 
 Usage:
-  python find_sdk.py 10.6  # Ignores SDKs < 10.6
+  python3 find_sdk.py 10.6  # Ignores SDKs < 10.6
 """
 
 import os
@@ -54,7 +54,7 @@ def CreateSymlinkForSDKAt(src, dst):
 
 def parse_version(version_str):
     """'10.6' => [10, 6]"""
-    return map(int, re.findall(r'(\d+)', version_str))
+    return list(map(int, re.findall(r'(\d+)', version_str)))
 
 
 def main():
@@ -90,11 +90,12 @@ def main():
 
     job = subprocess.Popen(['xcode-select', '-print-path'],
                            stdout=subprocess.PIPE,
-                           stderr=subprocess.STDOUT)
+                           stderr=subprocess.STDOUT,
+                           universal_newlines=True)
     out, err = job.communicate()
     if job.returncode != 0:
-        print >> sys.stderr, out
-        print >> sys.stderr, err
+        print(out, file=sys.stderr)
+        print(err, file=sys.stderr)
         raise Exception((
             'Error %d running xcode-select, you might have to run '
             '|sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer| '
@@ -119,32 +120,31 @@ def main():
     best_sdk = sorted(sdks, key=parse_version)[0]
 
     if options.verify and best_sdk != min_sdk_version and not options.sdk_path:
-        print >> sys.stderr, ''
-        print >> sys.stderr, '                                           vvvvvvv'
-        print >> sys.stderr, ''
-        print >> sys.stderr, \
-            'This build requires the %s SDK, but it was not found on your system.' \
-            % min_sdk_version
-        print >> sys.stderr, \
-            'Either install it, or explicitly set mac_sdk in your GYP_DEFINES.'
-        print >> sys.stderr, ''
-        print >> sys.stderr, '                                           ^^^^^^^'
-        print >> sys.stderr, ''
+        print('''
+                                           vvvvvvv
+
+This build requires the %s SDK, but it was not found on your system.
+
+Either install it, or explicitly set mac_sdk in your GYP_DEFINES.
+
+                                           ^^^^^^^'
+''' % min_sdk_version,
+              file=sys.stderr)
         return min_sdk_version
 
     if options.print_sdk_path:
         sdk_path = subprocess.check_output(
-            ['xcodebuild', '-version', '-sdk', 'macosx' + best_sdk,
-             'Path']).strip()
+            ['xcodebuild', '-version', '-sdk', 'macosx' + best_sdk, 'Path'],
+            universal_newlines=True).strip()
         if options.create_symlink_at:
-            print CreateSymlinkForSDKAt(sdk_path, options.create_symlink_at)
+            print(CreateSymlinkForSDKAt(sdk_path, options.create_symlink_at))
         else:
-            print sdk_path
+            print(sdk_path)
 
     return best_sdk
 
 
 if __name__ == '__main__':
     if sys.platform != 'darwin':
         raise Exception("This script only runs on Mac")
-    print main()
+    print(main())

build/mac/strip_save_dsym

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be