LLVM tools: Migrated all scripts to python3

This CL includes changes such as replacements of `\'` with `"` and
adding extra debugging output to some scripts.

Currently, the scripts are in python2, so migrating them to python3 so
they are more maintainable.

BUG=None
TEST=Ran each script by itself with various input (e.g. different
google3, tot, etc.).

Change-Id: Ib72b7744c6f7c13711c2db427f6524ff3cbc6205
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/1787738
Tested-by: Salud Lemus <saludlemus@google.com>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>

11 files changed, 318 insertions, 299 deletions

diff --git a/llvm_tools/auto_llvm_bisection.py b/llvm_tools/auto_llvm_bisection.py
index 125b504b..ede99e51 100755
--- a/llvm_tools/auto_llvm_bisection.py
+++ b/llvm_tools/auto_llvm_bisection.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -6,7 +6,6 @@
 
 """Performs bisection on LLVM based off a .JSON file."""
 
-from __future__ import division
 from __future__ import print_function
 
 import os
@@ -68,8 +67,8 @@ def main():
       # Update all tryjobs whose status is 'pending' to the result of `cros
       # buildresult`.
       while True:
-        print('\nAttempting to update all tryjobs whose \'status\' is '
-              '\'pending\':')
+        print('\nAttempting to update all tryjobs whose "status" is '
+              '"pending":')
         print('-' * 40)
 
         update_ret = subprocess.call(exec_update_tryjobs)
@@ -84,7 +83,7 @@ def main():
         delta_time = time.time() - update_start_time
 
         if delta_time > POLLING_LIMIT_SECS:
-          print('Unable to update tryjobs whose status is \'pending\' to '
+          print('Unable to update tryjobs whose status is "pending" to '
                 'the result of `cros buildresult`.')
 
           # Something is wrong with updating the tryjobs's 'status' via
diff --git a/llvm_tools/get_llvm_hash.py b/llvm_tools/get_llvm_hash.py
index c4a72bba..e08c30f8 100755
--- a/llvm_tools/get_llvm_hash.py
+++ b/llvm_tools/get_llvm_hash.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -14,7 +14,10 @@ import re
 import shutil
 import subprocess
 import tempfile
+
 from contextlib import contextmanager
+from subprocess_helpers import CheckCommand
+from subprocess_helpers import check_output
 
 import requests
 
@@ -22,19 +25,6 @@ _LLVM_GIT_URL = ('https://chromium.googlesource.com/external/github.com/llvm'
                  '/llvm-project')
 
 
-def CheckCommand(cmd):
-  """Executes the command using Popen()."""
-
-  cmd_obj = subprocess.Popen(
-      cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
-
-  stdout, _ = cmd_obj.communicate()
-
-  if cmd_obj.returncode:
-    print(stdout)
-    raise subprocess.CalledProcessError(cmd_obj.returncode, cmd)
-
-
 @contextmanager
 def CreateTempLLVMRepo(temp_dir):
   """Adds a LLVM worktree to 'temp_dir'.
@@ -70,7 +60,7 @@ def CreateTempLLVMRepo(temp_dir):
     yield temp_dir
   finally:
     if os.path.isdir(temp_dir):
-      subprocess.check_output([
+      check_output([
           'git', '-C', abs_path_to_llvm_project_dir, 'worktree', 'remove', '-f',
           temp_dir
       ])
@@ -106,7 +96,7 @@ def GetAndUpdateLLVMProjectInLLVMTools():
     # `git status` has a '-s'/'--short' option that shortens the output.
     # With the '-s' option, if no changes were made to the LLVM repo, then the
     # output (assigned to 'repo_status') would be empty.
-    repo_status = subprocess.check_output(
+    repo_status = check_output(
         ['git', '-C', abs_path_to_llvm_project_dir, 'status', '-s'])
 
     if repo_status.rstrip():
@@ -145,7 +135,7 @@ def GetGoogle3LLVMVersion():
   cat_cmd = ['cat', path_to_google3_llvm_version]
 
   # Get latest version.
-  g3_version = subprocess.check_output(cat_cmd)
+  g3_version = check_output(cat_cmd)
 
   # Change type to an integer
   return int(g3_version.rstrip())
@@ -323,7 +313,7 @@ class LLVMHash(object):
           'git', '-C', subdir, 'log', '--format=%B', '-n', '1', cur_hash
       ]
 
-      out = subprocess.check_output(find_llvm_cmd)
+      out = check_output(find_llvm_cmd)
 
       commit_svn_version = self.GetSVNVersionFromCommitMessage(out.rstrip())
 
@@ -356,7 +346,7 @@ class LLVMHash(object):
         'llvm-svn: %d' % llvm_version
     ]
 
-    hash_vals = subprocess.check_output(hash_cmd)
+    hash_vals = check_output(hash_cmd)
 
     return self._ParseCommitMessages(llvm_git_dir, hash_vals.rstrip(),
                                      llvm_version)
@@ -390,7 +380,7 @@ class LLVMHash(object):
         'git', 'ls-remote', _LLVM_GIT_URL, path_to_master_branch
     ]
 
-    llvm_tot_git_hash = subprocess.check_output(llvm_tot_git_hash_cmd)
+    llvm_tot_git_hash = check_output(llvm_tot_git_hash_cmd)
 
     return llvm_tot_git_hash.rstrip().split()[0]
 
diff --git a/llvm_tools/llvm_bisection.py b/llvm_tools/llvm_bisection.py
index d9eecce6..04fbdd55 100755
--- a/llvm_tools/llvm_bisection.py
+++ b/llvm_tools/llvm_bisection.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -6,7 +6,6 @@
 
 """Performs bisection on LLVM based off a .JSON file."""
 
-from __future__ import division
 from __future__ import print_function
 
 import argparse
@@ -20,7 +19,6 @@ from assert_not_in_chroot import VerifyOutsideChroot
 from get_llvm_hash import CreateTempLLVMRepo
 from get_llvm_hash import LLVMHash
 from modify_a_tryjob import AddTryjob
-from patch_manager import _ConvertToASCII
 from update_tryjob_status import FindTryjobIndex
 from update_tryjob_status import TryjobStatus
 
@@ -118,12 +116,12 @@ def GetCommandLineArgs():
       default=cros_root,
       help='the path to the chroot (default: %(default)s)')
 
-  # Add argument for the log level.
+  # Add argument for whether to display command contents to `stdout`.
   parser.add_argument(
-      '--log_level',
-      default='none',
-      choices=['none', 'quiet', 'average', 'verbose'],
-      help='the level for the logs (default: %(default)s)')
+      '--verbose',
+      action='store_true',
+      help='display contents of a command to the terminal '
+      '(default: %(default)s)')
 
   args_output = parser.parse_args()
 
@@ -133,7 +131,7 @@ def GetCommandLineArgs():
 
   if args_output.last_tested and not args_output.last_tested.endswith('.json'):
     raise ValueError(
-        'Filed provided %s does not end in \'.json\'' % args_output.last_tested)
+        'Filed provided %s does not end in ".json"' % args_output.last_tested)
 
   return args_output
 
@@ -144,7 +142,7 @@ def _ValidateStartAndEndAgainstJSONStartAndEnd(start, end, json_start,
 
   if start != json_start or end != json_end:
     raise ValueError('The start %d or the end %d version provided is '
-                     'different than \'start\' %d or \'end\' %d in the .JSON '
+                     'different than "start" %d or "end" %d in the .JSON '
                      'file' % (start, end, json_start, json_end))
 
 
@@ -179,7 +177,7 @@ def GetStartAndEndRevision(start, end, tryjobs):
   # Verify that each tryjob has a value for the 'status' key.
   for cur_tryjob_dict in tryjobs:
     if not cur_tryjob_dict.get('status', None):
-      raise ValueError('\'status\' is missing or has no value, please '
+      raise ValueError('"status" is missing or has no value, please '
                        'go to %s and update it' % cur_tryjob_dict['link'])
 
   all_bad_revisions = [end]
@@ -333,19 +331,19 @@ def CheckForExistingTryjobsInRevisionsToLaunch(revisions, jobs):
 
   for rev in revisions:
     if FindTryjobIndex(rev, jobs) is not None:
-      raise ValueError('Revision %d exists already in \'jobs\'' % rev)
+      raise ValueError('Revision %d exists already in "jobs"' % rev)
 
 
 def UpdateBisection(revisions, git_hashes, bisect_contents, last_tested,
                     update_packages, chroot_path, patch_metadata_file,
-                    extra_change_lists, options, builder, log_level):
+                    extra_change_lists, options, builder, verbose):
   """Adds tryjobs and updates the status file with the new tryjobs."""
 
   try:
     for svn_revision, git_hash in zip(revisions, git_hashes):
       tryjob_dict = AddTryjob(update_packages, git_hash, svn_revision,
                               chroot_path, patch_metadata_file,
-                              extra_change_lists, options, builder, log_level,
+                              extra_change_lists, options, builder, verbose,
                               svn_revision)
 
       bisect_contents['jobs'].append(tryjob_dict)
@@ -394,7 +392,7 @@ def main(args_output):
 
   try:
     with open(args_output.last_tested) as f:
-      bisect_contents = _ConvertToASCII(json.load(f))
+      bisect_contents = json.load(f)
   except IOError as err:
     if err.errno != errno.ENOENT:
       raise
@@ -450,7 +448,7 @@ def main(args_output):
                   args_output.last_tested, update_packages,
                   args_output.chroot_path, patch_metadata_file,
                   args_output.extra_change_lists, args_output.options,
-                  args_output.builder, args_output.log_level)
+                  args_output.builder, args_output.verbose)
 
 
 if __name__ == '__main__':
diff --git a/llvm_tools/llvm_patch_management.py b/llvm_tools/llvm_patch_management.py
index 90f82d30..522d4e34 100755
--- a/llvm_tools/llvm_patch_management.py
+++ b/llvm_tools/llvm_patch_management.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -8,19 +8,21 @@
 
 from __future__ import print_function
 
-from pipes import quote
 import argparse
 import os
 import patch_manager
 
 from assert_not_in_chroot import VerifyOutsideChroot
-from cros_utils import command_executer
 from failure_modes import FailureModes
 from get_llvm_hash import CreateTempLLVMRepo
 from get_llvm_hash import GetGoogle3LLVMVersion
 from get_llvm_hash import LLVMHash
+from subprocess_helpers import ChrootRunCommand
+from subprocess_helpers import ExecCommandAndCaptureOutput
 
-ce = command_executer.GetCommandExecuter()
+# If set to `True`, then the contents of `stdout` after executing a command will
+# be displayed to the terminal.
+verbose = False
 
 
 def GetCommandLineArgs():
@@ -52,12 +54,12 @@ def GetCommandLineArgs():
       default=['sys-devel/llvm'],
       help='the packages to manage their patches (default: %(default)s)')
 
-  # Add argument for the log level.
+  # Add argument for whether to display command contents to `stdout`.
   parser.add_argument(
-      '--log_level',
-      default='none',
-      choices=['none', 'quiet', 'average', 'verbose'],
-      help='the level for the logs (default: %(default)s)')
+      '--verbose',
+      action='store_true',
+      help='display contents of a command to the terminal '
+      '(default: %(default)s)')
 
   # Add argument for the LLVM version to use for patch management.
   parser.add_argument(
@@ -86,8 +88,9 @@ def GetCommandLineArgs():
   # Parse the command line.
   args_output = parser.parse_args()
 
-  # Set the log level for the command executer.
-  ce.SetLogLevel(log_level=args_output.log_level)
+  global verbose
+
+  verbose = args_output.verbose
 
   unique_packages = list(set(args_output.packages))
 
@@ -119,15 +122,8 @@ def GetPathToFilesDirectory(chroot_path, package):
     raise ValueError('Invalid chroot provided: %s' % chroot_path)
 
   # Get the absolute chroot path to the ebuild.
-  ret, chroot_ebuild_path, err = ce.ChrootRunCommandWOutput(
-      chromeos_root=chroot_path,
-      command='equery w %s' % package,
-      print_to_console=ce.GetLogLevel() == 'verbose')
-
-  if ret:  # Failed to get the absolute chroot path to package's ebuild.
-    raise ValueError(
-        'Failed to get the absolute chroot path of the package %s: %s' %
-        (package, err))
+  chroot_ebuild_path = ChrootRunCommand(
+      chroot_path, ['equery', 'w', package], verbose=verbose)
 
   # Get the absolute chroot path to $FILESDIR's parent directory.
   filesdir_parent_path = os.path.dirname(chroot_ebuild_path.strip())
@@ -175,20 +171,15 @@ def _CheckPatchMetadataPath(patch_metadata_path):
     raise ValueError('Invalid file provided: %s' % patch_metadata_path)
 
   if not patch_metadata_path.endswith('.json'):
-    raise ValueError('File does not end in \'.json\': %s' % patch_metadata_path)
+    raise ValueError('File does not end in ".json": %s' % patch_metadata_path)
 
 
 def _MoveSrcTreeHEADToGitHash(src_path, git_hash):
   """Moves HEAD to 'git_hash'."""
 
-  move_head_cmd = 'git -C %s checkout %s' % (quote(src_path), git_hash)
+  move_head_cmd = ['git', '-C', src_path, 'checkout', git_hash]
 
-  ret, _, err = ce.RunCommandWOutput(
-      move_head_cmd, print_to_console=ce.GetLogLevel() == 'verbose')
-
-  if ret:  # Failed to checkout to 'git_hash'.
-    raise ValueError('Failed to moved HEAD in %s to %s: %s' % (quote(src_path),
-                                                               git_hash, err))
+  ExecCommandAndCaptureOutput(move_head_cmd, verbose=verbose)
 
 
 def UpdatePackagesPatchMetadataFile(chroot_path, svn_version,
@@ -275,6 +266,9 @@ def main():
     print('The patch file %s has been modified for the packages:' %
           args_output.patch_metadata_file)
     print('\n'.join(args_output.packages))
+  else:
+    print('Applicable patches in %s applied successfully.' %
+          args_output.patch_metadata_file)
 
 
 if __name__ == '__main__':
diff --git a/llvm_tools/modify_a_tryjob.py b/llvm_tools/modify_a_tryjob.py
index f50f2bdc..20ba3541 100755
--- a/llvm_tools/modify_a_tryjob.py
+++ b/llvm_tools/modify_a_tryjob.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -17,7 +17,6 @@ import sys
 from assert_not_in_chroot import VerifyOutsideChroot
 from failure_modes import FailureModes
 from get_llvm_hash import GetLLVMHashAndVersionFromSVNOption
-from patch_manager import _ConvertToASCII
 from update_packages_and_run_tryjobs import RunTryJobs
 from update_tryjob_status import FindTryjobIndex
 from update_tryjob_status import TryjobStatus
@@ -89,12 +88,12 @@ def GetCommandLineArgs():
       default=cros_root,
       help='the path to the chroot (default: %(default)s)')
 
-  # Add argument for the log level.
+  # Add argument for whether to display command contents to `stdout`.
   parser.add_argument(
-      '--log_level',
-      default='none',
-      choices=['none', 'quiet', 'average', 'verbose'],
-      help='the level for the logs (default: %(default)s)')
+      '--verbose',
+      action='store_true',
+      help='display contents of a command to the terminal '
+      '(default: %(default)s)')
 
   args_output = parser.parse_args()
 
@@ -130,7 +129,7 @@ def GetCLAfterUpdatingPackages(packages, git_hash, svn_version, chroot_path,
 
 
 def CreateNewTryjobEntryForBisection(cl, extra_cls, options, builder,
-                                     chroot_path, log_level, cl_url, revision):
+                                     chroot_path, verbose, cl_url, revision):
   """Submits a tryjob and adds additional information."""
 
   # Get the tryjob results after submitting the tryjob.
@@ -145,7 +144,7 @@ def CreateNewTryjobEntryForBisection(cl, extra_cls, options, builder,
   #   }
   # ]
   tryjob_results = RunTryJobs(cl, extra_cls, options, [builder], chroot_path,
-                              log_level)
+                              verbose)
   print('\nTryjob:')
   print(tryjob_results[0])
 
@@ -159,24 +158,24 @@ def CreateNewTryjobEntryForBisection(cl, extra_cls, options, builder,
 
 
 def AddTryjob(packages, git_hash, revision, chroot_path, patch_metadata_file,
-              extra_cls, options, builder, log_level, svn_option):
+              extra_cls, options, builder, verbose, svn_option):
   """Submits a tryjob."""
 
-  update_chromeos_llvm_next_hash.ce.SetLogLevel(log_level=log_level)
+  update_chromeos_llvm_next_hash.verbose = verbose
 
   change_list = GetCLAfterUpdatingPackages(packages, git_hash, revision,
                                            chroot_path, patch_metadata_file,
                                            svn_option)
 
   tryjob_dict = CreateNewTryjobEntryForBisection(
-      change_list.cl_number, extra_cls, options, builder, chroot_path,
-      log_level, change_list.url, revision)
+      change_list.cl_number, extra_cls, options, builder, chroot_path, verbose,
+      change_list.url, revision)
 
   return tryjob_dict
 
 
 def PerformTryjobModification(revision, modify_tryjob, status_file, extra_cls,
-                              options, builder, chroot_path, log_level):
+                              options, builder, chroot_path, verbose):
   """Removes, relaunches, or adds a tryjob.
 
   Args:
@@ -189,7 +188,7 @@ def PerformTryjobModification(revision, modify_tryjob, status_file, extra_cls,
     builder: The builder to use for 'cros tryjob'.
     chroot_path: The absolute path to the chroot (used by 'cros tryjob' when
     relaunching a tryjob).
-    log_level: The level to use for the logs.
+    verbose: Determines whether to print the contents of a command to `stdout`.
   """
 
   # Format of 'bisect_contents':
@@ -204,7 +203,7 @@ def PerformTryjobModification(revision, modify_tryjob, status_file, extra_cls,
   #   ]
   # }
   with open(status_file) as tryjobs:
-    bisect_contents = _ConvertToASCII(json.load(tryjobs))
+    bisect_contents = json.load(tryjobs)
 
   if not bisect_contents['jobs'] and modify_tryjob != ModifyTryjob.ADD:
     sys.exit('No tryjobs in %s' % status_file)
@@ -219,14 +218,23 @@ def PerformTryjobModification(revision, modify_tryjob, status_file, extra_cls,
   # Determine the action to take based off of 'modify_tryjob'.
   if modify_tryjob == ModifyTryjob.REMOVE:
     del bisect_contents['jobs'][tryjob_index]
+
+    print('Successfully deleted the tryjob of revision %d' % revision)
   elif modify_tryjob == ModifyTryjob.RELAUNCH:
-    RunTryJobs(bisect_contents['jobs'][tryjob_index]['cl'],
-               bisect_contents['jobs'][tryjob_index]['extra_cls'],
-               bisect_contents['jobs'][tryjob_index]['options'],
-               bisect_contents['jobs'][tryjob_index]['builder'], chroot_path,
-               log_level)
+    # Need to update the tryjob link and buildbucket ID.
+    tryjob_results = RunTryJobs(
+        bisect_contents['jobs'][tryjob_index]['cl'],
+        bisect_contents['jobs'][tryjob_index]['extra_cls'],
+        bisect_contents['jobs'][tryjob_index]['options'],
+        bisect_contents['jobs'][tryjob_index]['builder'], chroot_path, verbose)
 
     bisect_contents['jobs'][tryjob_index]['status'] = TryjobStatus.PENDING.value
+    bisect_contents['jobs'][tryjob_index]['link'] = tryjob_results[0]['link']
+    bisect_contents['jobs'][tryjob_index]['buildbucket_id'] = tryjob_results[0][
+        'buildbucket_id']
+
+    print('Successfully relaunched the tryjob for revision %d and updated '
+          'the tryjob link to %s' % (revision, tryjob_results[0]['link']))
   elif modify_tryjob == ModifyTryjob.ADD:
     # Tryjob exists already.
     if tryjob_index is not None:
@@ -247,9 +255,11 @@ def PerformTryjobModification(revision, modify_tryjob, status_file, extra_cls,
 
       tryjob_dict = AddTryjob(update_packages, git_hash, revision, chroot_path,
                               patch_metadata_file, extra_cls, options, builder,
-                              log_level, revision)
+                              verbose, revision)
 
       bisect_contents['jobs'].append(tryjob_dict)
+
+      print('Successfully added tryjob of revision %d' % revision)
     else:
       raise ValueError('Failed to add tryjob to %s' % status_file)
   else:
@@ -271,7 +281,7 @@ def main():
       args_output.revision, ModifyTryjob(
           args_output.modify_tryjob), args_output.status_file,
       args_output.extra_change_lists, args_output.options, args_output.builder,
-      args_output.chroot_path, args_output.log_level)
+      args_output.chroot_path, args_output.verbose)
 
 
 if __name__ == '__main__':
diff --git a/llvm_tools/patch_manager.py b/llvm_tools/patch_manager.py
index 07c88e6a..806b944f 100755
--- a/llvm_tools/patch_manager.py
+++ b/llvm_tools/patch_manager.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -17,6 +17,8 @@ import sys
 from collections import namedtuple
 from failure_modes import FailureModes
 from get_llvm_hash import LLVMHash
+from subprocess_helpers import check_call
+from subprocess_helpers import check_output
 
 
 def is_directory(dir_path):
@@ -36,8 +38,8 @@ def is_patch_metadata_file(patch_metadata_file):
         'Invalid patch metadata file provided: %s' % patch_metadata_file)
 
   if not patch_metadata_file.endswith('.json'):
-    raise ValueError('Patch metadata file does not end in \'.json\': %s' %
-                     patch_metadata_file)
+    raise ValueError(
+        'Patch metadata file does not end in ".json": %s' % patch_metadata_file)
 
   return patch_metadata_file
 
@@ -58,11 +60,11 @@ def EnsureBisectModeAndSvnVersionAreSpecifiedTogether(failure_mode,
   """Validates that 'good_svn_version' is passed in only for bisection."""
 
   if failure_mode != FailureModes.BISECT_PATCHES.value and good_svn_version:
-    raise ValueError('\'good_svn_version\' is only available for bisection.')
+    raise ValueError('"good_svn_version" is only available for bisection.')
   elif failure_mode == FailureModes.BISECT_PATCHES.value and \
       not good_svn_version:
     raise ValueError('A good SVN version is required for bisection (used by'
-                     '\'git bisect start\'.')
+                     '"git bisect start".')
 
 
 def GetCommandLineArgs():
@@ -91,7 +93,7 @@ def GetCommandLineArgs():
       default=False,
       help='Determines whether bisection should continue after successfully '
       'bisecting a patch (default: %(default)s) - only used for '
-      '\'bisect_patches\'')
+      '"bisect_patches"')
 
   # Add argument for the LLVM version to use for patch management.
   parser.add_argument(
@@ -106,7 +108,7 @@ def GetCommandLineArgs():
       '--patch_metadata_file',
       required=True,
       type=is_patch_metadata_file,
-      help='the absolute path to the .json file in \'$FILESDIR/\' of the '
+      help='the absolute path to the .json file in "$FILESDIR/" of the '
       'package which has all the patches and their metadata if applicable')
 
   # Add argument for the absolute path to the ebuild's $FILESDIR path.
@@ -115,7 +117,7 @@ def GetCommandLineArgs():
       '--filesdir_path',
       required=True,
       type=is_directory,
-      help='the absolute path to the ebuild \'files/\' directory')
+      help='the absolute path to the ebuild "files/" directory')
 
   # Add argument for the absolute path to the unpacked sources.
   parser.add_argument(
@@ -147,7 +149,7 @@ def GetHEADSVNVersion(src_path):
 
   get_head_cmd = ['git', '-C', src_path, 'log', '-1', '--pretty=%B']
 
-  head_commit_message = subprocess.check_output(get_head_cmd)
+  head_commit_message = check_output(get_head_cmd)
 
   head_svn_version = LLVMHash().GetSVNVersionFromCommitMessage(
       head_commit_message)
@@ -161,8 +163,8 @@ def VerifyHEADIsTheSameAsSVNVersion(src_path, svn_version):
   head_svn_version = GetHEADSVNVersion(src_path)
 
   if head_svn_version != svn_version:
-    raise ValueError('HEAD\'s SVN version %d does not match \'svn_version\''
-                     ' %d, please move HEAD to \'svn_version\'s\' git hash.' %
+    raise ValueError('HEAD\'s SVN version %d does not match "svn_version"'
+                     ' %d, please move HEAD to "svn_version"s\' git hash.' %
                      (head_svn_version, svn_version))
 
 
@@ -242,7 +244,7 @@ def ApplyPatch(src_path, patch_path):
   ]
 
   try:
-    subprocess.check_output(test_patch_cmd)
+    check_output(test_patch_cmd)
 
   # If the mode is 'continue', then catching the exception makes sure that
   # the program does not exit on the first failed applicable patch.
@@ -251,7 +253,7 @@ def ApplyPatch(src_path, patch_path):
     return False
 
   # Test run succeeded on the patch.
-  subprocess.check_output(apply_patch_cmd)
+  check_output(apply_patch_cmd)
 
   return True
 
@@ -269,27 +271,12 @@ def UpdatePatchMetadataFile(patch_metadata_file, patches):
   """
 
   if not patch_metadata_file.endswith('.json'):
-    raise ValueError('File does not end in \'.json\': %s' % patch_metadata_file)
+    raise ValueError('File does not end in ".json": %s' % patch_metadata_file)
 
   with open(patch_metadata_file, 'w') as patch_file:
     json.dump(patches, patch_file, indent=4, separators=(',', ': '))
 
 
-def _ConvertToASCII(obj):
-  """Convert an object loaded from JSON to ASCII; JSON gives us unicode."""
-
-  # Using something like `object_hook` is insufficient, since it only fires on
-  # actual JSON objects. `encoding` fails, too, since the default decoder always
-  # uses unicode() to decode strings.
-  if isinstance(obj, unicode):
-    return str(obj)
-  if isinstance(obj, dict):
-    return {_ConvertToASCII(k): _ConvertToASCII(v) for k, v in obj.iteritems()}
-  if isinstance(obj, list):
-    return [_ConvertToASCII(v) for v in obj]
-  return obj
-
-
 def GetCommitHashesForBisection(src_path, good_svn_version, bad_svn_version):
   """Gets the good and bad commit hashes required by `git bisect start`."""
 
@@ -312,7 +299,7 @@ def PerformBisection(src_path, good_commit, bad_commit, svn_version,
       'git', '-C', src_path, 'bisect', 'start', bad_commit, good_commit
   ]
 
-  subprocess.check_output(bisect_start_cmd)
+  check_output(bisect_start_cmd)
 
   bisect_run_cmd = [
       'git', '-C', src_path, 'bisect', 'run',
@@ -323,7 +310,7 @@ def PerformBisection(src_path, good_commit, bad_commit, svn_version,
       '%d' % num_patches
   ]
 
-  subprocess.check_call(bisect_run_cmd)
+  check_call(bisect_run_cmd)
 
   # Successfully bisected the patch, so retrieve the SVN version from the
   # commit message.
@@ -331,12 +318,11 @@ def PerformBisection(src_path, good_commit, bad_commit, svn_version,
       'git', '-C', src_path, 'show', 'refs/bisect/bad'
   ]
 
-  bad_commit_message = subprocess.check_output(
-      get_bad_commit_from_bisect_run_cmd)
+  bad_commit_message = check_output(get_bad_commit_from_bisect_run_cmd)
 
   end_bisection_cmd = ['git', '-C', src_path, 'bisect', 'reset']
 
-  subprocess.check_output(end_bisection_cmd)
+  check_output(end_bisection_cmd)
 
   # `git bisect run` returns the bad commit hash and the commit message.
   bad_version = LLVMHash().GetSVNVersionFromCommitMessage(
@@ -350,11 +336,11 @@ def CleanSrcTree(src_path):
 
   reset_src_tree_cmd = ['git', '-C', src_path, 'reset', 'HEAD', '--hard']
 
-  subprocess.check_output(reset_src_tree_cmd)
+  check_output(reset_src_tree_cmd)
 
   clean_src_tree_cmd = ['git', '-C', src_path, 'clean', '-fd']
 
-  subprocess.check_output(clean_src_tree_cmd)
+  check_output(clean_src_tree_cmd)
 
 
 def SaveSrcTreeState(src_path):
@@ -362,7 +348,7 @@ def SaveSrcTreeState(src_path):
 
   save_src_tree_cmd = ['git', '-C', src_path, 'stash', '-a']
 
-  subprocess.check_output(save_src_tree_cmd)
+  check_output(save_src_tree_cmd)
 
 
 def RestoreSrcTreeState(src_path, bad_commit_hash):
@@ -370,11 +356,11 @@ def RestoreSrcTreeState(src_path, bad_commit_hash):
 
   checkout_cmd = ['git', '-C', src_path, 'checkout', bad_commit_hash]
 
-  subprocess.check_output(checkout_cmd)
+  check_output(checkout_cmd)
 
   get_changes_cmd = ['git', '-C', src_path, 'stash', 'pop']
 
-  subprocess.check_output(get_changes_cmd)
+  check_output(get_changes_cmd)
 
 
 def HandlePatches(svn_version,
@@ -454,7 +440,7 @@ def HandlePatches(svn_version,
   failed_patches = []
 
   with open(patch_metadata_file) as patch_file:
-    patch_file_contents = _ConvertToASCII(json.load(patch_file))
+    patch_file_contents = json.load(patch_file)
 
     if mode == FailureModes.BISECT_PATCHES:
       # A good and bad commit are required by `git bisect start`.
diff --git a/llvm_tools/subprocess_helpers.py b/llvm_tools/subprocess_helpers.py
new file mode 100644
index 00000000..8845112c
--- /dev/null
+++ b/llvm_tools/subprocess_helpers.py
@@ -0,0 +1,58 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Helpers/wrappers for the subprocess module for migration to python3."""
+
+from __future__ import print_function
+
+import subprocess
+
+
+def CheckCommand(cmd):
+  """Executes the command using Popen()."""
+
+  cmd_obj = subprocess.Popen(
+      cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, encoding='UTF-8')
+
+  stdout, _ = cmd_obj.communicate()
+
+  if cmd_obj.returncode:
+    print(stdout)
+    raise subprocess.CalledProcessError(cmd_obj.returncode, cmd)
+
+
+def check_output(cmd, cwd=None):
+  """Wrapper for pre-python3 subprocess.check_output()."""
+
+  return subprocess.check_output(cmd, encoding='UTF-8', cwd=cwd)
+
+
+def check_call(cmd, cwd=None):
+  """Wrapper for pre-python3 subprocess.check_call()."""
+
+  subprocess.check_call(cmd, encoding='UTF-8', cwd=cwd)
+
+
+# FIXME: CTRL+C does not work when executing a command inside the chroot via
+# `cros_sdk`.
+def ChrootRunCommand(chroot_path, cmd, verbose=False):
+  """Runs the command inside the chroot."""
+
+  exec_chroot_cmd = ['cros_sdk', '--']
+  exec_chroot_cmd.extend(cmd)
+
+  return ExecCommandAndCaptureOutput(
+      exec_chroot_cmd, cwd=chroot_path, verbose=verbose)
+
+
+def ExecCommandAndCaptureOutput(cmd, cwd=None, verbose=False):
+  """Executes the command and prints to stdout if possible."""
+
+  out = check_output(cmd, cwd=cwd).rstrip()
+
+  if verbose and out:
+    print(out)
+
+  return out
diff --git a/llvm_tools/update_all_tryjobs_with_auto.py b/llvm_tools/update_all_tryjobs_with_auto.py
index 4a670c34..511bfffa 100755
--- a/llvm_tools/update_all_tryjobs_with_auto.py
+++ b/llvm_tools/update_all_tryjobs_with_auto.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -13,7 +13,6 @@ import json
 import os
 
 from assert_not_in_chroot import VerifyOutsideChroot
-from patch_manager import _ConvertToASCII
 from update_tryjob_status import GetAutoResult
 from update_tryjob_status import TryjobStatus
 
@@ -51,7 +50,7 @@ def GetCommandLineArgs():
 
   if not os.path.isfile(args_output.last_tested) or \
       not args_output.last_tested.endswith('.json'):
-    raise ValueError('File does not exist or does not ending in \'.json\' '
+    raise ValueError('File does not exist or does not ending in ".json" '
                      ': %s' % args_output.last_tested)
 
   return args_output
@@ -65,7 +64,7 @@ def main():
   args_output = GetCommandLineArgs()
 
   with open(args_output.last_tested) as tryjobs:
-    bisect_contents = _ConvertToASCII(json.load(tryjobs))
+    bisect_contents = json.load(tryjobs)
 
   for tryjob in bisect_contents['jobs']:
     if tryjob['status'] == TryjobStatus.PENDING.value:
diff --git a/llvm_tools/update_chromeos_llvm_next_hash.py b/llvm_tools/update_chromeos_llvm_next_hash.py
index aa63b76c..cf92b489 100755
--- a/llvm_tools/update_chromeos_llvm_next_hash.py
+++ b/llvm_tools/update_chromeos_llvm_next_hash.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -13,19 +13,22 @@ for review.
 from __future__ import print_function
 
 from collections import namedtuple
-from pipes import quote
 import argparse
-import llvm_patch_management
 import os
 import re
+import subprocess
 
 from assert_not_in_chroot import VerifyOutsideChroot
-from cros_utils import command_executer
 from failure_modes import FailureModes
 from get_llvm_hash import GetLLVMHashAndVersionFromSVNOption
 from get_llvm_hash import is_svn_option
+from subprocess_helpers import ChrootRunCommand
+from subprocess_helpers import ExecCommandAndCaptureOutput
+import llvm_patch_management
 
-ce = command_executer.GetCommandExecuter()
+# If set to `True`, then the contents of `stdout` after executing a command will
+# be displayed to the terminal.
+verbose = False
 
 CommitContents = namedtuple('CommitContents', ['url', 'cl_number'])
 
@@ -63,12 +66,12 @@ def GetCommandLineArgs():
       help='the ebuilds to update their hash for llvm-next ' \
           '(default: %(default)s)')
 
-  # Add argument for the log level.
+  # Add argument for whether to display command contents to `stdout`.
   parser.add_argument(
-      '--log_level',
-      default='none',
-      choices=['none', 'quiet', 'average', 'verbose'],
-      help='the level for the logs (default: %(default)s)')
+      '--verbose',
+      action='store_true',
+      help='display contents of a command to the terminal '
+      '(default: %(default)s)')
 
   # Add argument for the LLVM version to use.
   parser.add_argument(
@@ -100,8 +103,9 @@ def GetCommandLineArgs():
   # Parse the command line.
   args_output = parser.parse_args()
 
-  # Set the log level for the command executer.
-  ce.SetLogLevel(log_level=args_output.log_level)
+  global verbose
+
+  verbose = args_output.verbose
 
   return args_output
 
@@ -127,17 +131,9 @@ def GetChrootBuildPaths(chromeos_root, package_list):
   # Find the chroot path for each package's ebuild.
   for cur_package in sorted(set(package_list)):
     # Cmd to find the chroot path for the package.
-    equery_cmd = 'equery w %s' % cur_package
-
-    # Find the chroot path for the package.
-    ret, chroot_path, err = ce.ChrootRunCommandWOutput(
-        chromeos_root=chromeos_root,
-        command=equery_cmd,
-        print_to_console=ce.GetLogLevel() == 'verbose')
+    equery_cmd = ['equery', 'w', cur_package]
 
-    if ret:  # failed to get the chroot path
-      raise ValueError('Failed to get chroot path for the package (%s): %s' %
-                       (cur_package, err))
+    chroot_path = ChrootRunCommand(chromeos_root, equery_cmd, verbose=verbose)
 
     chroot_paths.append(chroot_path.strip())
 
@@ -269,12 +265,9 @@ def UpdateBuildLLVMNextHash(ebuild_path, llvm_hash, llvm_version):
   parent_dir = os.path.dirname(ebuild_path)
 
   # Stage the changes.
-  ret, _, err = ce.RunCommandWOutput(
-      'git -C %s add %s' % (parent_dir, ebuild_path),
-      print_to_console=ce.GetLogLevel() == 'verbose')
+  stage_changes_cmd = ['git', '-C', parent_dir, 'add', ebuild_path]
 
-  if ret:  # failed to stage the changes
-    raise ValueError('Failed to stage the ebuild for commit: %s' % err)
+  ExecCommandAndCaptureOutput(stage_changes_cmd, verbose=verbose)
 
 
 def ReplaceLLVMNextHash(ebuild_lines, is_updated, llvm_regex, llvm_hash,
@@ -333,12 +326,11 @@ def UprevEbuild(symlink):
   path_to_symlink_dir = os.path.dirname(symlink)
 
   # Stage the new symlink for commit.
-  ret, _, err = ce.RunCommandWOutput(
-      'git -C %s mv %s %s' % (path_to_symlink_dir, symlink, new_symlink),
-      print_to_console=ce.GetLogLevel() == 'verbose')
+  stage_symlink_cmd = [
+      'git', '-C', path_to_symlink_dir, 'mv', symlink, new_symlink
+  ]
 
-  if ret:  # failed to stage the symlink for commit
-    raise ValueError('Failed to stage the symlink for commit: %s' % err)
+  ExecCommandAndCaptureOutput(stage_symlink_cmd, verbose=verbose)
 
 
 def _CreateRepo(path_to_repo_dir, llvm_hash):
@@ -355,18 +347,21 @@ def _CreateRepo(path_to_repo_dir, llvm_hash):
   if not os.path.isdir(path_to_repo_dir):
     raise ValueError('Invalid directory path provided: %s' % path_to_repo_dir)
 
-  create_repo_cmd = ' && '.join([
-      'cd %s' % path_to_repo_dir,
-      'git reset HEAD --hard',
-      'repo start llvm-next-update-%s' % llvm_hash,
-  ])
+  reset_changes_cmd = [
+      'git',
+      '-C',
+      path_to_repo_dir,
+      'reset',
+      'HEAD',
+      '--hard',
+  ]
 
-  ret, _, err = ce.RunCommandWOutput(
-      create_repo_cmd, print_to_console=ce.GetLogLevel() == 'verbose')
+  ExecCommandAndCaptureOutput(reset_changes_cmd, verbose=verbose)
 
-  if ret:  # failed to create a repo for the changes
-    raise ValueError('Failed to create the repo (llvm-next-update-%s): %s' %
-                     (llvm_hash, err))
+  create_repo_cmd = ['repo', 'start', 'llvm-next-update-%s' % llvm_hash]
+
+  ExecCommandAndCaptureOutput(
+      create_repo_cmd, cwd=path_to_repo_dir, verbose=verbose)
 
 
 def _DeleteRepo(path_to_repo_dir, llvm_hash):
@@ -383,18 +378,22 @@ def _DeleteRepo(path_to_repo_dir, llvm_hash):
   if not os.path.isdir(path_to_repo_dir):
     raise ValueError('Invalid directory path provided: %s' % path_to_repo_dir)
 
-  delete_repo_cmd = ' && '.join([
-      'cd %s' % path_to_repo_dir, 'git checkout cros/master',
-      'git reset HEAD --hard',
-      'git branch -D llvm-next-update-%s' % llvm_hash
-  ])
+  checkout_to_master_cmd = [
+      'git', '-C', path_to_repo_dir, 'checkout', 'cros/master'
+  ]
+
+  ExecCommandAndCaptureOutput(checkout_to_master_cmd, verbose=verbose)
+
+  reset_head_cmd = ['git', '-C', path_to_repo_dir, 'reset', 'HEAD', '--hard']
 
-  ret, _, err = ce.RunCommandWOutput(
-      delete_repo_cmd, print_to_console=ce.GetLogLevel() == 'verbose')
+  ExecCommandAndCaptureOutput(reset_head_cmd, verbose=verbose)
 
-  if ret:  # failed to delete the repo
-    raise ValueError('Failed to delete the repo (llvm-next-update-%s): %s' %
-                     (llvm_hash, err))
+  delete_repo_cmd = [
+      'git', '-C', path_to_repo_dir, 'branch', '-D',
+      'llvm-next-update-%s' % llvm_hash
+  ]
+
+  ExecCommandAndCaptureOutput(delete_repo_cmd, verbose=verbose)
 
 
 def GetGerritRepoUploadContents(repo_upload_contents):
@@ -446,26 +445,36 @@ def UploadChanges(path_to_repo_dir, llvm_hash, commit_messages):
   if not os.path.isdir(path_to_repo_dir):
     raise ValueError('Invalid directory path provided: %s' % path_to_repo_dir)
 
-  commit_cmd = 'cd %s && git commit %s' % (path_to_repo_dir, commit_messages)
-
-  ret, _, err = ce.RunCommandWOutput(
-      commit_cmd, print_to_console=ce.GetLogLevel() == 'verbose')
+  commit_cmd = [
+      'git',
+      'commit',
+  ]
+  commit_cmd.extend(commit_messages)
 
-  if ret:  # failed to commit the changes
-    raise ValueError('Failed to create a commit for the changes: %s' % err)
+  ExecCommandAndCaptureOutput(commit_cmd, cwd=path_to_repo_dir, verbose=verbose)
 
   # Upload the changes for review.
-  upload_change_cmd = 'cd %s && ' \
-      'yes | repo upload --br=llvm-next-update-%s --no-verify' % (
-          path_to_repo_dir, llvm_hash)
+  upload_change_cmd = (
+      'yes | repo upload --br=llvm-next-update-%s --no-verify' % llvm_hash)
+
+  # NOTE: Need `shell=True` in order to pipe `yes` into `repo upload ...`.
+  #
+  # The CL URL is sent to 'stderr', so need to redirect 'stderr' to 'stdout'.
+  upload_changes_obj = subprocess.Popen(
+      upload_change_cmd,
+      cwd=path_to_repo_dir,
+      shell=True,
+      encoding='UTF-8',
+      stdout=subprocess.PIPE,
+      stderr=subprocess.STDOUT)
 
-  ret, _, err = ce.RunCommandWOutput(
-      upload_change_cmd, print_to_console=ce.GetLogLevel() == 'verbose')
+  out, _ = upload_changes_obj.communicate()
 
-  if ret:  # failed to upload the changes for review
-    raise ValueError('Failed to upload changes for review: %s' % err)
+  if upload_changes_obj.returncode:  # Failed to upload changes.
+    print(out)
+    raise ValueError('Failed to upload changes for review')
 
-  return GetGerritRepoUploadContents(err)
+  return GetGerritRepoUploadContents(out.rstrip())
 
 
 def CreatePathDictionaryFromPackages(chroot_path, update_packages):
@@ -504,13 +513,12 @@ def RemovePatchesFromFilesDir(patches_to_remove):
   """
 
   for cur_patch in patches_to_remove:
-    ret, _, err = ce.RunCommandWOutput(
-        'git -C %s rm -f %s' % (os.path.dirname(cur_patch), cur_patch),
-        print_to_console=ce.GetLogLevel() == 'verbose')
+    remove_patch_cmd = [
+        'git', '-C',
+        os.path.dirname(cur_patch), 'rm', '-f', cur_patch
+    ]
 
-    if ret:  # Failed to remove the patch in $FILESDIR.
-      raise ValueError(
-          'Failed to remove patch %s: %s' % (os.path.basename(cur_patch), err))
+    ExecCommandAndCaptureOutput(remove_patch_cmd, verbose=verbose)
 
 
 def StagePatchMetadataFileForCommit(patch_metadata_file_path):
@@ -529,15 +537,12 @@ def StagePatchMetadataFileForCommit(patch_metadata_file_path):
         'Invalid patch metadata file provided: %s' % patch_metadata_file_path)
 
   # Cmd to stage the patch metadata file for commit.
-  stage_patch_file = 'git -C %s add %s' % (
-      os.path.dirname(patch_metadata_file_path), patch_metadata_file_path)
-
-  ret, _, err = ce.RunCommandWOutput(
-      stage_patch_file, print_to_console=ce.GetLogLevel() == 'verbose')
+  stage_patch_file = [
+      'git', '-C',
+      os.path.dirname(patch_metadata_file_path), 'add', patch_metadata_file_path
+  ]
 
-  if ret:  # Failed to stage the patch metadata file for commit.
-    raise ValueError('Failed to stage patch metadata file %s for commit: %s' %
-                     (os.path.basename(patch_metadata_file_path), err))
+  ExecCommandAndCaptureOutput(stage_patch_file, verbose=verbose)
 
 
 def StagePackagesPatchResultsForCommit(package_info_dict, commit_messages):
@@ -559,32 +564,29 @@ def StagePackagesPatchResultsForCommit(package_info_dict, commit_messages):
         patch_info_dict['removed_patches'] or \
         patch_info_dict['modified_metadata']:
       cur_package_header = 'For the package %s:' % package_name
-      commit_messages.append('-m %s' % quote(cur_package_header))
+      commit_messages.append('-m %s' % cur_package_header)
 
     # Add to the commit message that the patch metadata file was modified.
     if patch_info_dict['modified_metadata']:
       patch_metadata_path = patch_info_dict['modified_metadata']
-      commit_messages.append(
-          '-m %s' % quote('The patch metadata file %s was '
-                          'modified' % os.path.basename(patch_metadata_path)))
+      commit_messages.append('-m %s' % 'The patch metadata file %s was '
+                             'modified' % os.path.basename(patch_metadata_path))
 
       StagePatchMetadataFileForCommit(patch_metadata_path)
 
     # Add each disabled patch to the commit message.
     if patch_info_dict['disabled_patches']:
-      commit_messages.append(
-          '-m %s' % quote('The following patches were disabled:'))
+      commit_messages.append('-m %s' % 'The following patches were disabled:')
 
       for patch_path in patch_info_dict['disabled_patches']:
-        commit_messages.append('-m %s' % quote(os.path.basename(patch_path)))
+        commit_messages.append('-m %s' % os.path.basename(patch_path))
 
     # Add each removed patch to the commit message.
     if patch_info_dict['removed_patches']:
-      commit_messages.append(
-          '-m %s' % quote('The following patches were removed:'))
+      commit_messages.append('-m %s' % 'The following patches were removed:')
 
       for patch_path in patch_info_dict['removed_patches']:
-        commit_messages.append('-m %s' % quote(os.path.basename(patch_path)))
+        commit_messages.append('-m %s' % os.path.basename(patch_path))
 
       RemovePatchesFromFilesDir(patch_info_dict['removed_patches'])
 
@@ -616,11 +618,14 @@ def UpdatePackages(packages, llvm_hash, llvm_version, chroot_path,
     Gerrit commit URL and the second pair is the change list number.
   """
 
+  # Determines whether to print the result of each executed command.
+  llvm_patch_management.verbose = verbose
+
   # Construct a dictionary where the key is the absolute path of the symlink to
   # the package and the value is the absolute path to the ebuild of the package.
   paths_dict = CreatePathDictionaryFromPackages(chroot_path, packages)
 
-  repo_path = os.path.dirname(paths_dict.itervalues().next())
+  repo_path = os.path.dirname(next(iter(paths_dict.values())))
 
   _CreateRepo(repo_path, llvm_hash)
 
@@ -634,10 +639,9 @@ def UpdatePackages(packages, llvm_hash, llvm_version, chroot_path,
     else:
       commit_message_header = 'llvm-next: Update packages to r%d' % llvm_version
 
-    commit_messages = ['-m %s' % quote(commit_message_header)]
+    commit_messages = ['-m %s' % commit_message_header]
 
-    commit_messages.append(
-        '-m %s' % quote('Following packages have been updated:'))
+    commit_messages.append('-m %s' % 'Following packages have been updated:')
 
     # Holds the list of packages that are updating.
     packages = []
@@ -662,10 +666,9 @@ def UpdatePackages(packages, llvm_hash, llvm_version, chroot_path,
 
       new_commit_message = '%s/%s' % (parent_dir_name, cur_dir_name)
 
-      commit_messages.append('-m %s' % quote(new_commit_message))
+      commit_messages.append('-m %s' % new_commit_message)
 
     # Handle the patches for each package.
-    llvm_patch_management.ce.SetLogLevel(log_level=ce.GetLogLevel())
     package_info_dict = llvm_patch_management.UpdatePackagesPatchMetadataFile(
         chroot_path, llvm_version, patch_metadata_file, packages, mode)
 
@@ -673,7 +676,7 @@ def UpdatePackages(packages, llvm_hash, llvm_version, chroot_path,
     commit_messages = StagePackagesPatchResultsForCommit(
         package_info_dict, commit_messages)
 
-    change_list = UploadChanges(repo_path, llvm_hash, ' '.join(commit_messages))
+    change_list = UploadChanges(repo_path, llvm_hash, commit_messages)
 
   finally:
     _DeleteRepo(repo_path, llvm_hash)
diff --git a/llvm_tools/update_packages_and_run_tryjobs.py b/llvm_tools/update_packages_and_run_tryjobs.py
index 487b7f6a..f4fc234f 100755
--- a/llvm_tools/update_packages_and_run_tryjobs.py
+++ b/llvm_tools/update_packages_and_run_tryjobs.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -8,19 +8,17 @@
 
 from __future__ import print_function
 
-from pipes import quote
 import argparse
 import datetime
 import json
 import os
-import sys
 
 from assert_not_in_chroot import VerifyOutsideChroot
-from cros_utils import command_executer
-from cros_utils.buildbot_utils import ParseTryjobBuildbucketId
 from failure_modes import FailureModes
 from get_llvm_hash import GetLLVMHashAndVersionFromSVNOption
 from get_llvm_hash import is_svn_option
+from subprocess_helpers import ChrootRunCommand
+from subprocess_helpers import ExecCommandAndCaptureOutput
 import update_chromeos_llvm_next_hash
 
 
@@ -41,7 +39,7 @@ def GetCommandLineArgs():
   # Create parser and add optional command-line arguments.
   parser = argparse.ArgumentParser(
       description='Runs a tryjob if successfully updated packages\''
-      '\'LLVM_NEXT_HASH\'.')
+      '"LLVM_NEXT_HASH".')
 
   # Add argument for the absolute path to the file that contains information on
   # the previous tested svn version.
@@ -86,12 +84,12 @@ def GetCommandLineArgs():
       default=cros_root,
       help='the path to the chroot (default: %(default)s)')
 
-  # Add argument for the log level.
+  # Add argument for whether to display command contents to `stdout`.
   parser.add_argument(
-      '--log_level',
-      default='none',
-      choices=['none', 'quiet', 'average', 'verbose'],
-      help='the level for the logs (default: %(default)s)')
+      '--verbose',
+      action='store_true',
+      help='display contents of a command to the terminal '
+      '(default: %(default)s)')
 
   # Add argument for the LLVM version to use.
   parser.add_argument(
@@ -166,11 +164,11 @@ def GetTryJobCommand(change_list, extra_change_lists, options, builder):
   if options:
     tryjob_cmd.extend('--%s' % option for option in options)
 
-  return ' '.join(tryjob_cmd)
+  return tryjob_cmd
 
 
 def RunTryJobs(cl_number, extra_change_lists, options, builders, chroot_path,
-               log_level):
+               verbose):
   """Runs a tryjob/tryjobs.
 
   Args:
@@ -180,7 +178,7 @@ def RunTryJobs(cl_number, extra_change_lists, options, builders, chroot_path,
     options: Any options to be passed into the 'tryjob' command.
     builders: All the builders to run the 'tryjob' with.
     chroot_path: The absolute path to the chroot.
-    log_level: The log level to be used for the command_executer.
+    verbose: Print command contents to `stdout`.
 
   Returns:
     A list that contains stdout contents of each tryjob, where stdout is
@@ -191,8 +189,6 @@ def RunTryJobs(cl_number, extra_change_lists, options, builders, chroot_path,
     ValueError: Failed to submit a tryjob.
   """
 
-  ce = command_executer.GetCommandExecuter(log_level=log_level)
-
   # Contains the results of each tryjob. The results are retrieved from 'out'
   # which is stdout of the command executer.
   tryjob_results = []
@@ -206,23 +202,13 @@ def RunTryJobs(cl_number, extra_change_lists, options, builders, chroot_path,
     tryjob_cmd = GetTryJobCommand(cl_number, extra_change_lists, options,
                                   cur_builder)
 
-    ret, out, err = ce.ChrootRunCommandWOutput(
-        chromeos_root=chroot_path,
-        command=tryjob_cmd,
-        print_to_console=log_level == 'verbose')
-
-    if ret:  # Failed to submit a tryjob.
-      print(err, file=sys.stderr)
-      raise ValueError('Failed to submit tryjob.')
-
-    # stderr can be noisy e.g. warnings when entering chroot, so ignore it.
-    # e.g. cros_sdk:enter_chroot: Gclient cache dir "/tmp/git-cache" is not...
+    out = ChrootRunCommand(chroot_path, tryjob_cmd, verbose=verbose)
 
     tryjob_launch_time = datetime.datetime.utcnow()
 
-    buildbucket_id = int(ParseTryjobBuildbucketId(out.rstrip()))
+    tryjob_contents = json.loads(out)
 
-    tryjob_contents = json.loads(out.rstrip())
+    buildbucket_id = int(tryjob_contents[0]['buildbucket_id'])
 
     new_tryjob = {
         'launch_time': str(tryjob_launch_time),
@@ -235,27 +221,31 @@ def RunTryJobs(cl_number, extra_change_lists, options, builders, chroot_path,
 
     tryjob_results.append(new_tryjob)
 
-  AddTryjobLinkToCL(tryjob_results, cl_number, chroot_path, log_level)
+  AddTryjobLinkToCL(tryjob_results, cl_number, chroot_path)
 
   return tryjob_results
 
 
-def AddTryjobLinkToCL(tryjobs, cl, chroot_path, log_level):
+def AddTryjobLinkToCL(tryjobs, cl, chroot_path):
   """Adds the tryjob link(s) to the CL via `gerrit message <CL> <message>`."""
 
-  tryjob_links = ['Started the following tryjobs:']
-  tryjob_links.extend(quote(tryjob['link']) for tryjob in tryjobs)
+  # NOTE: Invoking `cros_sdk` does not make each tryjob link appear on its own
+  # line, so invoking the `gerrit` command directly instead of using `cros_sdk`
+  # to do it for us.
+  #
+  # FIXME: Need to figure out why `cros_sdk` does not add each tryjob link as a
+  # newline.
+  gerrit_abs_path = os.path.join(chroot_path, 'chromite/bin/gerrit')
 
-  add_message_cmd = 'gerrit message %d \"%s\"' % (cl, '\n'.join(tryjob_links))
+  tryjob_links = ['Started the following tryjobs:']
+  tryjob_links.extend(tryjob['link'] for tryjob in tryjobs)
 
-  ce = command_executer.GetCommandExecuter(log_level=log_level)
-  ret, _, err = ce.ChrootRunCommandWOutput(
-      chromeos_root=chroot_path,
-      command=add_message_cmd,
-      print_to_console=log_level == 'verbose')
+  add_message_cmd = [
+      gerrit_abs_path, 'message',
+      str(cl), '\n'.join(tryjob_links)
+  ]
 
-  if ret:  # Failed to add tryjob link(s) to CL.
-    raise ValueError('Failed to add tryjob links to CL %d: %s' % (cl, err))
+  ExecCommandAndCaptureOutput(add_message_cmd)
 
 
 def main():
@@ -289,7 +279,7 @@ def main():
           (svn_version, last_svn_version, args_output.last_tested))
     return
 
-  update_chromeos_llvm_next_hash.ce.SetLogLevel(log_level=args_output.log_level)
+  update_chromeos_llvm_next_hash.verbose = args_output.verbose
 
   change_list = update_chromeos_llvm_next_hash.UpdatePackages(
       update_packages, git_hash, svn_version, args_output.chroot_path,
@@ -302,7 +292,7 @@ def main():
   tryjob_results = RunTryJobs(change_list.cl_number,
                               args_output.extra_change_lists,
                               args_output.options, args_output.builders,
-                              args_output.chroot_path, args_output.log_level)
+                              args_output.chroot_path, args_output.verbose)
 
   print('Tryjobs:')
   for tryjob in tryjob_results:
diff --git a/llvm_tools/update_tryjob_status.py b/llvm_tools/update_tryjob_status.py
index 4648db12..38eab8e5 100755
--- a/llvm_tools/update_tryjob_status.py
+++ b/llvm_tools/update_tryjob_status.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright 2019 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -16,8 +16,7 @@ import subprocess
 import sys
 
 from assert_not_in_chroot import VerifyOutsideChroot
-from cros_utils import command_executer
-from patch_manager import _ConvertToASCII
+from subprocess_helpers import ChrootRunCommand
 from test_helpers import CreateTemporaryJsonFile
 
 
@@ -97,7 +96,7 @@ def GetCommandLineArgs():
       '--set_status',
       required=True,
       choices=[tryjob_status.value for tryjob_status in TryjobStatus],
-      help='Sets the \'status\' field of the tryjob.')
+      help='Sets the "status" field of the tryjob.')
 
   # Add argument that determines which revision to search for in the list of
   # tryjobs.
@@ -118,7 +117,7 @@ def GetCommandLineArgs():
   parser.add_argument(
       '--custom_script',
       help='The absolute path to the custom script to execute (its exit code '
-      'should be %d for \'good\', %d for \'bad\', or %d for \'skip\')' %
+      'should be %d for "good", %d for "bad", or %d for "skip")' %
       (CustomScriptStatus.GOOD.value, CustomScriptStatus.BAD.value,
        CustomScriptStatus.SKIP.value))
 
@@ -126,7 +125,7 @@ def GetCommandLineArgs():
 
   if not os.path.isfile(args_output.status_file) or \
       not args_output.status_file.endswith('.json'):
-    raise ValueError('File does not exist or does not ending in \'.json\' '
+    raise ValueError('File does not exist or does not ending in ".json" '
                      ': %s' % args_output.status_file)
 
   if args_output.set_status == TryjobStatus.CUSTOM_SCRIPT.value and \
@@ -169,19 +168,12 @@ def FindTryjobIndex(revision, tryjobs_list):
 def GetStatusFromCrosBuildResult(chroot_path, buildbucket_id):
   """Retrieves the 'status' using 'cros buildresult'."""
 
-  ce = command_executer.GetCommandExecuter(log_level=None)
+  get_buildbucket_id_cmd = [
+      'cros', 'buildresult', '--buildbucket-id',
+      str(buildbucket_id), '--report', 'json'
+  ]
 
-  get_buildbucket_id_cmd = ('cros buildresult --buildbucket-id %d '
-                            '--report json' % buildbucket_id)
-
-  ret, tryjob_json, err = ce.ChrootRunCommandWOutput(
-      chromeos_root=chroot_path,
-      command=get_buildbucket_id_cmd,
-      print_to_console=False)
-
-  if ret:  # Failed to get the contents of the tryjob.
-    raise ValueError('Failed to get JSON contents of the tryjobs buildbucket '
-                     'ID %d: %s' % (buildbucket_id, err))
+  tryjob_json = ChrootRunCommand(chroot_path, get_buildbucket_id_cmd)
 
   tryjob_contents = json.loads(tryjob_json)
 
@@ -197,7 +189,7 @@ def GetAutoResult(chroot_path, buildbucket_id):
   # The string returned by 'cros buildresult' might not be in the mapping.
   if build_result not in builder_status_mapping:
     raise ValueError(
-        '\'cros buildresult\' return value is invalid: %s' % build_result)
+        '"cros buildresult" return value is invalid: %s' % build_result)
 
   return builder_status_mapping[build_result]
 
@@ -243,8 +235,8 @@ def GetCustomScriptResult(custom_script, status_file, tryjob_contents):
 
       raise ValueError(
           'Custom script %s exit code %d did not match '
-          'any of the expected exit codes: %d for \'good\', %d '
-          'for \'bad\', or %d for \'skip\'.\nPlease check %s for information '
+          'any of the expected exit codes: %d for "good", %d '
+          'for "bad", or %d for "skip".\nPlease check %s for information '
           'about the tryjob: %s' %
           (custom_script, exec_script_cmd_obj.returncode,
            CustomScriptStatus.GOOD.value, CustomScriptStatus.BAD.value,
@@ -281,7 +273,7 @@ def UpdateTryjobStatus(revision, set_status, status_file, chroot_path,
   #   ]
   # }
   with open(status_file) as tryjobs:
-    bisect_contents = _ConvertToASCII(json.load(tryjobs))
+    bisect_contents = json.load(tryjobs)
 
   if not bisect_contents['jobs']:
     sys.exit('No tryjobs in %s' % status_file)
@@ -309,7 +301,7 @@ def UpdateTryjobStatus(revision, set_status, status_file, chroot_path,
     bisect_contents['jobs'][tryjob_index]['status'] = GetCustomScriptResult(
         custom_script, status_file, bisect_contents['jobs'][tryjob_index])
   else:
-    raise ValueError('Invalid \'set_status\' option provided: %s' % set_status)
+    raise ValueError('Invalid "set_status" option provided: %s' % set_status)
 
   with open(status_file, 'w') as update_tryjobs:
     json.dump(bisect_contents, update_tryjobs, indent=4, separators=(',', ': '))