Linux: add script to remove bundled libraries.

BUG=none
R=thestig@chromium.org

Review URL: https://codereview.chromium.org/23037005

git-svn-id: http://src.chromium.org/svn/trunk/src/build@218816 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

linux/unbundle/README

@@ -17,12 +17,28 @@ libraries is the norm.
 
 Usage:
 
-replace_gyp_files.py <gyp-flags>
+1. remove_bundled_libraries.py <preserved-directories>
 
-For example: replace_gyp_files.py -Duse_system_harfbuzz=1
+   For example: remove_bundled_libraries.py third_party/mesa
 
-The script ignores flags other than -D for convenience. This makes it possible
-to have a variable e.g. ${myconf} with all the options, and execute:
+   The script scans sources looking for third_party directories.
+   Everything that is not explicitly preserved is removed (except for
+   gyp files), and the script fails if any directory passed on command
+   line does not exist (to ensure list is kept up to date).
 
-build/linux/unbundle/replace_gyp_files.py ${myconf}
-build/gyp_chromium ${myconf}
+   This is intended to be used on sources extracted from a tarball,
+   not a repository.
+
+   NOTE: by default this will not remove anything (for safety). Pass
+   --do-remove flag to actually remove files.
+
+2. replace_gyp_files.py <gyp-flags>
+
+   For example: replace_gyp_files.py -Duse_system_harfbuzz=1
+
+   The script ignores flags other than -D for convenience. This makes it
+   possible to have a variable e.g. ${myconf} with all the options, and
+   execute:
+
+   build/linux/unbundle/replace_gyp_files.py ${myconf}
+   build/gyp_chromium ${myconf}

linux/unbundle/remove_bundled_libraries.py

@@ -0,0 +1,87 @@
+#!/usr/bin/env python
+# 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.
+
+"""
+Removes bundled libraries to make sure they are not used.
+
+See README for more details.
+"""
+
+
+import optparse
+import os.path
+import sys
+
+
+def DoMain(argv):
+  my_dirname = os.path.abspath(os.path.dirname(__file__))
+  source_tree_root = os.path.abspath(
+    os.path.join(my_dirname, '..', '..', '..'))
+
+  if os.path.join(source_tree_root, 'build', 'linux', 'unbundle') != my_dirname:
+    print ('Sanity check failed: please run this script from ' +
+           'build/linux/unbundle directory.')
+    return 1
+
+  parser = optparse.OptionParser()
+  parser.add_option('--do-remove', action='store_true')
+
+  options, args = parser.parse_args(argv)
+
+  exclusion_used = {}
+  for exclusion in args:
+    exclusion_used[exclusion] = False
+
+  for root, dirs, files in os.walk(source_tree_root, topdown=False):
+    # Only look at paths which contain a "third_party" component
+    # (note that e.g. third_party.png doesn't count).
+    root_relpath = os.path.relpath(root, source_tree_root)
+    if 'third_party' not in root_relpath.split(os.sep):
+      continue
+
+    for f in files:
+      path = os.path.join(root, f)
+      relpath = os.path.relpath(path, source_tree_root)
+
+      excluded = False
+      for exclusion in args:
+        if relpath.startswith(exclusion):
+          # Multiple exclusions can match the same path. Go through all of them
+          # and mark each one as used.
+          exclusion_used[exclusion] = True
+          excluded = True
+      if excluded:
+        continue
+
+      # Deleting gyp files almost always leads to gyp failures.
+      # These files come from Chromium project, and can be replaced if needed.
+      if f.endswith('.gyp') or f.endswith('.gypi'):
+        continue
+
+      if options.do_remove:
+        # Delete the file - best way to ensure it's not used during build.
+        os.remove(path)
+      else:
+        # By default just print paths that would be removed.
+        print path
+
+  exit_code = 0
+
+  # Fail if exclusion list contains stale entries - this helps keep it
+  # up to date.
+  for exclusion, used in exclusion_used.iteritems():
+    if not used:
+      print '%s does not exist' % exclusion
+      exit_code = 1
+
+  if not options.do_remove:
+    print ('To actually remove files printed above, please pass ' +
+           '--do-remove flag.')
+
+  return exit_code
+
+
+if __name__ == '__main__':
+  sys.exit(DoMain(sys.argv[1:]))