script: added bisect-test.py git bisect script

this can be used to work out what commit broke a set of tests

script/bisect-test.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python
+# use git bisect to work out what commit caused a test failure
+# Copyright Andrew Tridgell 2010
+# released under GNU GPL v3 or later
+
+
+from subprocess import call, check_call, Popen, PIPE
+import os, tempfile, sys
+from optparse import OptionParser
+
+parser = OptionParser()
+parser.add_option("", "--tests", help="list of tests to run", default='')
+parser.add_option("", "--good", help="known good revision (default HEAD)", default='HEAD')
+parser.add_option("", "--bad", help="known bad revision (default HEAD~100)", default='HEAD~100')
+parser.add_option("", "--skip-build-errors", help="skip revision where make fails", default=False)
+parser.add_option("", "--autogen", help="run autogen before each build",action="store_true", default=False)
+parser.add_option("", "--configure", help="run configure.developer before each build",
+    action="store_true", default=False)
+parser.add_option("", "--clean", help="run make clean before each build",
+    action="store_true", default=False)
+parser.add_option("-j", "", help="use make -j N", dest='N', type='int', action="store", default=1)
+
+(opts, args) = parser.parse_args()
+
+
+def run_cmd(cmd, dir=".", show=True, output=False, checkfail=True):
+    if show:
+        print("Running: '%s' in '%s'" % (cmd, dir))
+    if output:
+        return Popen([cmd], shell=True, stdout=PIPE, cwd=dir).communicate()[0]
+    elif checkfail:
+        return check_call(cmd, shell=True, cwd=dir)
+    else:
+        return call(cmd, shell=True, cwd=dir)
+
+def find_git_root():
+    '''get to the top of the git repo'''
+    p=os.getcwd()
+    while p != '/':
+        if os.path.isdir(os.path.join(p, ".git")):
+            return p
+        p = os.path.abspath(os.path.join(p, '..'))
+    return None
+
+cwd = os.getcwd()
+gitroot = find_git_root()
+
+# create a bisect script
+f = tempfile.NamedTemporaryFile(delete=False)
+f.write("set -x\n")
+f.write("cd %s || exit 125\n" % cwd)
+if opts.autogen:
+    f.write("./autogen.sh || exit 125\n")
+if opts.configure:
+    f.write("./configure.developer || exit 125\n")
+if opts.clean:
+    f.write("make clean || exit 125\n")
+if opts.skip_build_errors:
+    f.write("make -j %u || exit 125\n" % opts.N)
+else:
+    f.write("make -j %u || exit 1\n" % opts.N)
+f.write("make -j %u test TESTS='%s' FAIL_IMMEDIATELY=1 || exit 1\n" % (opts.N, opts.tests))
+f.write("exit 0\n")
+f.close()
+
+def cleanup():
+    run_cmd("git bisect reset", dir=gitroot)
+    os.unlink(f.name)
+    sys.exit(-1)
+
+# run bisect
+ret = -1
+try:
+    run_cmd("git bisect reset", dir=gitroot, show=False, checkfail=False)
+    run_cmd("git bisect start %s %s --" % (opts.good, opts.bad), dir=gitroot)
+    ret = run_cmd("git bisect run bash %s" % f.name, dir=gitroot, show=True, checkfail=False)
+except KeyboardInterrupt:
+    print("Cleaning up")
+    cleanup()
+except Exception, reason:
+    print("Failed bisect: %s" % reason)
+    cleanup()
+
+os.unlink(f.name)
+sys.exit(ret)