Make write_library_dependencies.py find all transitive dependencies

build/android/write_ordered_libraries.py

Index: build/android/write_ordered_libraries.py
diff --git a/build/android/write_ordered_libraries.py b/build/android/write_ordered_libraries.py
index e887672e2900b6c4dbf704f6f3357869ce5f773e..30622708219b99aa9b9dc4c00b9a56df2f8ed87f 100755
--- a/build/android/write_ordered_libraries.py
+++ b/build/android/write_ordered_libraries.py
@@ -7,29 +7,95 @@
 """Writes dependency ordered list of native libraries.
 
 This list of libraries is used for several steps of building an APK.
+In the component build, the --input-libraries only needs to be the top-level
+library (i.e. libcontent_shell_content_view). This will then use readelf to
+inspect the shared libraries and determine the full list of (non-system)
+libraries that should be included in the APK.
 """
 
+# TODO(cjhopman): See if we can expose the list of library dependencies from
+# gyp, rather than calculating it ourselves.
+# http://crbug.com/2255588

[Yaron, 2013/04/02 01:30:35]

That link doesn't work for me. Wrong #?

And ya, seems pretty inefficient as is and belongs in gyp

[cjhopman, 2013/04/02 20:47:31]

Done.

+
 import json
 import optparse
 import os
+import re
 import sys
 
 from pylib import build_utils
 
+options = None

[Yaron, 2013/04/02 01:30:35]

globals should be prefixed with "_"

[cjhopman, 2013/04/02 20:47:31]

Done.

+libraries_dir = None
+
+def FullLibraryPath(library_name):
+  return '%s/%s' % (libraries_dir, library_name)
+
+
+def IsSystemLibrary(library_name):
+  return not os.path.exists(FullLibraryPath(library_name))
+
+
+def CallReadElf(library_name):
+  readelf_cmd = [options.readelf,
+                 '-d',
+                 FullLibraryPath(library_name)]
+  return build_utils.CheckCallDie(readelf_cmd)
+
+
+def GetDependencies(library_name):

[Yaron, 2013/04/02 01:30:35]

GetNonSystemLibraryDependencies

[cjhopman, 2013/04/02 20:47:31]

Done.

+  elf = CallReadElf(library_name)
+  library_re = re.compile(

[Yaron, 2013/04/02 01:30:35]

compile this once at module level

[cjhopman, 2013/04/02 20:47:31]

Done.

+      '.*NEEDED.*Shared library: \[(?P<library_name>[\w/.]+)\]')
+  matches = library_re.findall(elf)
+  return set([lib for lib in matches if not IsSystemLibrary(lib)])

[Yaron, 2013/04/02 01:30:35]

If you're always excluding system libraries, how are they pushed/bundled into
the apk?

[cjhopman, 2013/04/02 20:47:31]

Added this to the file-level comment. System libraries are included with the
system and not bundled in the APK.

[Yaron, 2013/04/02 21:00:41]

Heh, of course. So you don't need to System.loadLibrary them either? dalvik will
find them?

+
+
+def GetSortedTransitiveDependencies(libraries):
+  """Returns all transitive library dependencies in dependency order."""
+  def GraphNode(library):
+    return (library, GetDependencies(library))
+
+  # First: find all library dependencies.
+  unchecked_deps = libraries
+  all_deps = set(libraries)
+  while unchecked_deps:
+    lib = unchecked_deps.pop()
+    new_deps = GetDependencies(lib).difference(all_deps)
+    unchecked_deps.extend(new_deps)
+    all_deps = all_deps.union(new_deps)
+
+  # Then: simple, slow topological sort.
+  sorted_deps = []
+  unsorted_deps = dict(map(GraphNode, all_deps))
+  while unsorted_deps:
+    for (library, dependencies) in unsorted_deps.items():

[Yaron, 2013/04/02 01:30:35]

nit: no parens

[cjhopman, 2013/04/02 20:47:31]

Done.

+      if not dependencies.intersection(unsorted_deps.keys()):
+        sorted_deps.append(library)
+        del unsorted_deps[library]
+
+  return sorted_deps
+
 
 def main(argv):
   parser = optparse.OptionParser()
 
   parser.add_option('--input-libraries',
       help='A list of top-level input libraries')
+  parser.add_option('--readelf')

[Yaron, 2013/04/02 01:30:35]

Add help

[cjhopman, 2013/04/02 20:47:31]

Done.

   parser.add_option('--output', help='Path to the generated .json file')
   parser.add_option('--stamp', help='Path to touch on success')
 
+  global options
   options, _ = parser.parse_args()
 
   libraries = build_utils.ParseGypList(options.input_libraries)
+  global libraries_dir
+  libraries_dir = os.path.dirname(libraries[0])
   libraries = [os.path.basename(lib) for lib in libraries]
 
+  libraries = GetSortedTransitiveDependencies(libraries)
+
   with open(options.output, 'w') as outfile:
     json.dump(libraries, outfile)