Bug 1530016 - Drop bogus entries from the generated-sources tarball. r=froydnj

On Android we apparently try to include the cpufeatures.c file from the
NDK as part of the generated-sources tarball. While this works, it makes
tar drop the bogus entry for safety reasons when unpacking the archive.
It also makes tar return an error, which is undesirable for searchfox.
It's better to just skip the entry when building the tarball.

Differential Revision: https://phabricator.services.mozilla.com/D20942

--HG--
extra : moz-landing-system : lando

python/mozbuild/mozbuild/action/package_generated_sources.py

@@ -10,7 +10,9 @@ import os.path
 import sys
 
 import buildconfig
+import mozpack.path as mozpath
 from mozpack.archive import create_tar_gz_from_files
+from mozpack.files import BaseFile
 from mozbuild.generated_sources import get_generated_sources
 
 
@@ -20,8 +22,18 @@ def main(argv):
     parser.add_argument('outputfile', help='File to write output to')
     args = parser.parse_args(argv)
 
+    objdir_abspath = mozpath.abspath(buildconfig.topobjdir)
+    def is_valid_entry(entry):
+        if isinstance(entry[1], BaseFile):
+            entry_abspath = mozpath.abspath(entry[1].path)
+        else:
+            entry_abspath = mozpath.abspath(entry[1])
+        if not entry_abspath.startswith(objdir_abspath):
+            print("Warning: omitting generated source [%s] from archive" % entry_abspath, file=sys.stderr)
+            return False
+        return True
 
-    files = dict(get_generated_sources())
+    files = dict(filter(is_valid_entry, get_generated_sources()))
     with open(args.outputfile, 'wb') as fh:
         create_tar_gz_from_files(fh, files, compresslevel=5)