1 files changed, 44 insertions, 0 deletions
diff --git a/testing/tools/common.py b/testing/tools/common.py
index 737169f8d3..fc16004210 100755
--- a/testing/tools/common.py
+++ b/testing/tools/common.py
@@ -3,6 +3,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import datetime
 import glob
 import os
 import re
@@ -26,6 +27,38 @@ def RunCommand(cmd):
   except subprocess.CalledProcessError as e:
     return e
 
+
+def RunCommandPropagateErr(cmd, stdout_has_errors=False,
+                           exit_status_on_error=None):
+  """Run a command as a subprocess.
+
+  Errors in that subprocess are printed out if it returns an error exit code.
+
+  Args:
+    cmd: Command to run as a list of strings.
+    stdout_has_errors: Whether to print stdout instead of stderr on an error
+        exit.
+    exit_status_on_error: If specified, upon an error in the subprocess the
+        caller script exits immediately with the given status.
+  """
+  p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+  output, err = p.communicate()
+
+  if p.returncode:
+    PrintErr('\nError when invoking "%s"' % ' '.join(cmd))
+    if stdout_has_errors:
+      PrintErr(output)
+
+    PrintErr(err)
+
+    if exit_status_on_error is not None:
+      sys.exit(exit_status_on_error)
+
+    return None
+
+  return output
+
+
 # RunCommandExtractHashedFiles returns a tuple: (raised_exception, hashed_files)
 # It runs the given command. If it fails it will return an exception and None.
 # If it succeeds it will return None and the list of processed files extracted
@@ -110,3 +143,14 @@ def GetBooleanGnArg(arg_name, build_dir, verbose=False):
   if verbose:
     print >> sys.stderr, "Found '%s' for value of %s" % (arg_match_output, arg)
   return arg_match_output == 'true'
+
+
+def PrintWithTime(s):
+  """Prints s prepended by a timestamp."""
+  print '[%s] %s' % (datetime.datetime.now().strftime("%Y%m%d %H:%M:%S"),
+                     s)
+
+
+def PrintErr(s):
+  """Prints s to stderr."""
+  print >> sys.stderr, s