Auto-updating script for Windows toolchain

Updates third_party/win_toolchain to pull down a toolchain
based on SHA1. The intention is that this will be a DEPS hook
once it's ready for more broad usage and the rest of
infrastructure is ready.

R=maruel@chromium.org
TBR=cpu@chromium.org
BUG=323300

Review URL: https://codereview.chromium.org/70493006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237369 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 80 insertions, 2 deletions

diff --git a/tools/win/toolchain/get_toolchain_if_necessary.py b/tools/win/toolchain/get_toolchain_if_necessary.py
new file mode 100644
index 0000000..e93e6f0
--- /dev/null
+++ b/tools/win/toolchain/get_toolchain_if_necessary.py
@@ -0,0 +1,75 @@
+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import hashlib
+import os
+import subprocess
+import sys
+
+
+BASEDIR = os.path.dirname(os.path.abspath(__file__))
+
+
+def CalculateHash(root):
+  """Calculates the sha1 of the paths to all files in the given |root| and the
+  contents of those files, and returns as a hex string."""
+  assert not os.path.isabs(root)
+  assert os.path.normpath(root) == root
+  digest = hashlib.sha1()
+  count = 0
+  for root, dirs, files in os.walk(root):
+    dirs.sort()
+    for name in sorted(f.lower() for f in files):
+      path = os.path.join(root, name)
+      digest.update(path.lower())
+      with open(path, 'rb') as f:
+        digest.update(f.read())
+  return digest.hexdigest()
+
+
+def main():
+  if sys.platform not in ('win32', 'cygwin'):
+    return 0
+
+  if len(sys.argv) != 1:
+    print >> sys.stderr, 'Unexpected arguments.'
+    return 1
+
+  # Move to same location as .gclient. This is a no-op when run via gclient.
+  os.chdir(os.path.normpath(os.path.join(BASEDIR, '..\\..\\..\\..')))
+  toolchain_dir = 'src\\third_party\\win_toolchain'
+  target_dir = os.path.join(toolchain_dir, 'files')
+
+  sha1path = os.path.join(toolchain_dir, 'toolchain.sha1')
+  desired_hash = ''
+  if os.path.isfile(sha1path):
+    with open(sha1path, 'rb') as f:
+      desired_hash = f.read().strip()
+
+  # If the current hash doesn't match what we want in the file, nuke and pave.
+  # Note that this script is only run when a .sha1 file is updated (per DEPS)
+  # so this relatively expensive step of hashing everything only happens when
+  # the toolchain is updated.
+  current_hash = CalculateHash(target_dir)
+  if current_hash != desired_hash:
+    print 'Windows toolchain out of date or doesn\'t exist, updating...'
+    if os.path.isdir(target_dir):
+      subprocess.check_call('rmdir /s/q "%s"' % target_dir, shell=True)
+    subprocess.check_call([
+        sys.executable,
+        'src\\tools\\win\\toolchain\\toolchain2013.py',
+        '--targetdir', target_dir])
+
+  current_hash = CalculateHash(target_dir)
+  if current_hash != desired_hash:
+    print >> sys.stderr, (
+        'Got wrong hash after pulling a new toolchain. '
+        'Wanted \'%s\', got \'%s\'.' % (
+            desired_hash, current_hash))
+    return 1
+  return 0
+
+
+if __name__ == '__main__':
+  sys.exit(main())
diff --git a/tools/win/toolchain/toolchain.py b/tools/win/toolchain/toolchain.py
index e98fc9b..1c16fb1 100644
--- a/tools/win/toolchain/toolchain.py
+++ b/tools/win/toolchain/toolchain.py
@@ -57,10 +57,11 @@ def DeleteAllTempDirs():
 def Download(url, local_path):
   """Download a large-ish binary file and print some status information while
   doing so."""
-  sys.stdout.write('Downloading %s...' % url)
+  sys.stdout.write('Downloading %s...\n' % url)
   req = urllib2.urlopen(url)
   content_length = int(req.headers.get('Content-Length', 0))
   bytes_read = 0
+  terminator = '\r' if sys.stdout.isatty() else '\n'
   with open(local_path, 'wb') as file:
     while True:
       chunk = req.read(1024 * 1024)
@@ -68,7 +69,8 @@ def Download(url, local_path):
         break
       bytes_read += len(chunk)
       file.write(chunk)
-      sys.stdout.write('.')
+      sys.stdout.write('... %d/%d%s' % (bytes_read, content_length, terminator))
+      sys.stdout.flush()
   sys.stdout.write('\n')
   if content_length and content_length != bytes_read:
     raise SystemExit('Got incorrect number of bytes downloading %s' % url)
@@ -224,6 +226,7 @@ def ExtractIso(iso_path):
   .exe)."""
   target_path = TempDir()
   sys.stdout.write('Extracting %s...\n' % iso_path)
+  sys.stdout.flush()
   # TODO(scottmg): Do this (and exe) manually with python code.
   # Note that at the beginning of main() we set the working directory to 7z's
   # location.