Issue 6600: RunCommand should return an object with various attributes

chromite/lib/cros_build_lib.py

 # Copyright (c) 2010 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.
 
 """Common python commands used by various build scripts."""
 
 import os
 import subprocess
 import sys
 
 _STDOUT_IS_TTY = hasattr(sys.stdout, 'isatty') and sys.stdout.isatty()
 
+
+class CommandResult(object):
+  """An object to store various attributes of a child process."""
+
+  def __init__(self):
+    self.cmd = None
+    self.error = None
+    self.output = None
+    self.returncode = None
+
+
+class RunCommandError(Exception):
+  """Error caught in RunCommand() method."""
+  pass
+
+
 def RunCommand(cmd, print_cmd=True, error_ok=False, error_message=None,
                exit_code=False, redirect_stdout=False, redirect_stderr=False,
                cwd=None, input=None, enter_chroot=False, shell=False):
   """Runs a command.
 
   Keyword arguments:
     cmd - cmd to run.  Should be input to subprocess.Popen.
     print_cmd -- prints the command before running it.
     error_ok -- does not raise an exception on error.
     error_message -- prints out this message when an error occurrs.
     exit_code -- returns the return code of the shell command.
     redirect_stdout -- returns the stdout.
     redirect_stderr -- holds stderr output until input is communicated.
     cwd -- the working directory to run this cmd.
     input -- input to pipe into this command through stdin.
     enter_chroot -- this command should be run from within the chroot.  If set,
       cwd must point to the scripts directory.
     shell -- If shell is True, the specified command will be executed through the shell.
   Raises:
     Exception:  Raises generic exception on error with optional error_message.
   """
   # Set default for variables.
   stdout = None
   stderr = None
   stdin = None
   output = ''
+  cmd_result = CommandResult()
 
   # Modify defaults based on parameters.
   if redirect_stdout:  stdout = subprocess.PIPE
   if redirect_stderr:  stderr = subprocess.PIPE
   if input:  stdin = subprocess.PIPE
   if isinstance(cmd, basestring):
     if enter_chroot: cmd = './enter_chroot.sh -- ' + cmd
     cmd_str = cmd
   else:
     if enter_chroot: cmd = ['./enter_chroot.sh', '--'] + cmd
     cmd_str = ' '.join(cmd)
 
   # Print out the command before running.
   if print_cmd:
     Info('RunCommand: %s' % cmd_str)
+  cmd_result.cmd = cmd_str
 
   try:
-    proc = subprocess.Popen(cmd, cwd=cwd, stdin=stdin,
+    proc = subprocess.Popen(cmd_str, cwd=cwd, stdin=stdin,
                             stdout=stdout, stderr=stderr,
                             shell=shell)
-    (output, error) = proc.communicate(input)
+    (cmd_result.output, cmd_result.error) = proc.communicate(input)
     if exit_code:
-      return proc.returncode
+      cmd_result.returncode = proc.returncode
 
     if not error_ok and proc.returncode:
-      raise Exception('Command "%s" failed.\n' % cmd_str +
-                      (error_message or error or output or ''))
+      msg = ('Command "%s" failed.\n' % cmd_str +
+             (error_message or cmd_result.error or cmd_result.output or ''))
+      raise RunCommandError(msg)
   except Exception,e:
     if not error_ok:
       raise
     else:
       Warning(str(e))
 
-  return output
+  return cmd_result
 
 
 class Color(object):
   """Conditionally wraps text in ANSI color escape sequences."""
   BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(8)
   BOLD = -1
   COLOR_START = '\033[1;%dm'
   BOLD_START = '\033[1m'
   RESET = '\033[0m'
 
@@ skipping 66 matching lines @@
   while directories:
     directory = directories.pop()
     for name in os.listdir(directory):
       fullpath = os.path.join(directory, name)
       if os.path.isfile(fullpath):
         files_list.append(fullpath)
       elif os.path.isdir(fullpath):
         directories.append(fullpath)
 
   return files_list