1 files changed, 134 insertions, 0 deletions
diff --git a/llvm_tools/auto_llvm_bisection.py b/llvm_tools/auto_llvm_bisection.py
new file mode 100755
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+++ b/llvm_tools/auto_llvm_bisection.py
@@ -0,0 +1,134 @@
+#!/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
+# found in the LICENSE file.
+
+"""Performs bisection on LLVM based off a .JSON file."""
+
+from __future__ import print_function
+
+import os
+import subprocess
+import sys
+import time
+import traceback
+
+from assert_not_in_chroot import VerifyOutsideChroot
+from update_all_tryjobs_with_auto import GetPathToUpdateAllTryjobsWithAutoScript
+from llvm_bisection import BisectionExitStatus
+import llvm_bisection
+
+# Used to re-try for 'llvm_bisection.py' to attempt to launch more tryjobs.
+BISECTION_RETRY_TIME_SECS = 10 * 60
+
+# Wait time to then poll each tryjob whose 'status' value is 'pending'.
+POLL_RETRY_TIME_SECS = 30 * 60
+
+# The number of attempts for 'llvm_bisection.py' to launch more tryjobs.
+#
+# It is reset (break out of the `for` loop/ exit the program) if successfully
+# launched more tryjobs or bisection is finished (no more revisions between
+# start and end of the bisection).
+BISECTION_ATTEMPTS = 3
+
+# The limit for updating all tryjobs whose 'status' is 'pending'.
+#
+# If the time that has passed for polling exceeds this value, then the program
+# will exit with the appropriate exit code.
+POLLING_LIMIT_SECS = 18 * 60 * 60
+
+
+def main():
+  """Bisects LLVM using the result of `cros buildresult` of each tryjob.
+
+  Raises:
+    AssertionError: The script was run inside the chroot.
+  """
+
+  VerifyOutsideChroot()
+
+  args_output = llvm_bisection.GetCommandLineArgs()
+
+  exec_update_tryjobs = [
+      GetPathToUpdateAllTryjobsWithAutoScript(), '--chroot_path',
+      args_output.chroot_path, '--last_tested', args_output.last_tested
+  ]
+
+  if os.path.isfile(args_output.last_tested):
+    print('Resuming bisection for %s' % args_output.last_tested)
+  else:
+    print('Starting a new bisection for %s' % args_output.last_tested)
+
+  while True:
+    if os.path.isfile(args_output.last_tested):
+      update_start_time = time.time()
+
+      # 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('-' * 40)
+
+        update_ret = subprocess.call(exec_update_tryjobs)
+
+        print('-' * 40)
+
+        # Successfully updated all tryjobs whose 'status' was 'pending'/ no
+        # updates were needed (all tryjobs already have been updated).
+        if update_ret == 0:
+          break
+
+        delta_time = time.time() - update_start_time
+
+        if delta_time > POLLING_LIMIT_SECS:
+          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
+          # `cros buildresult` (e.g. network issue, etc.).
+          sys.exit(1)
+
+        print('Sleeping for %d minutes.' % (POLL_RETRY_TIME_SECS // 60))
+        time.sleep(POLL_RETRY_TIME_SECS)
+
+    # Launch more tryjobs if possible to narrow down the bad commit/revision or
+    # terminate the bisection because the bad commit/revision was found.
+    for cur_try in range(1, BISECTION_ATTEMPTS + 1):
+      try:
+        print('\nAttempting to launch more tryjobs if possible:')
+        print('-' * 40)
+
+        bisection_ret = llvm_bisection.main(args_output)
+
+        print('-' * 40)
+
+        # Exit code 126 means that there are no more revisions to test between
+        # 'start' and 'end', so bisection is complete.
+        if bisection_ret == BisectionExitStatus.BISECTION_COMPLETE.value:
+          sys.exit(0)
+
+        # Successfully launched more tryjobs.
+        break
+      except Exception:
+        traceback.print_exc()
+
+        print('-' * 40)
+
+        # Exceeded the number of times to launch more tryjobs.
+        if cur_try == BISECTION_ATTEMPTS:
+          print('Unable to continue bisection.')
+
+          sys.exit(1)
+
+        num_retries_left = BISECTION_ATTEMPTS - cur_try
+
+        print('Retries left to continue bisection %d.' % num_retries_left)
+
+        print('Sleeping for %d minutes.' % (BISECTION_RETRY_TIME_SECS // 60))
+        time.sleep(BISECTION_RETRY_TIME_SECS)
+
+
+if __name__ == '__main__':
+  main()