1 files changed, 73 insertions, 0 deletions
diff --git a/python/virtualenv/bin/rebuild-script.py b/python/virtualenv/bin/rebuild-script.py
new file mode 100755
index 000000000..a816af3eb
--- /dev/null
+++ b/python/virtualenv/bin/rebuild-script.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+"""
+Helper script to rebuild virtualenv.py from virtualenv_support
+"""
+from __future__ import print_function
+
+import os
+import re
+import codecs
+from zlib import crc32
+
+here = os.path.dirname(__file__)
+script = os.path.join(here, '..', 'virtualenv.py')
+
+gzip = codecs.lookup('zlib')
+b64 = codecs.lookup('base64')
+
+file_regex = re.compile(
+    br'##file (.*?)\n([a-zA-Z][a-zA-Z0-9_]+)\s*=\s*convert\("""\n(.*?)"""\)',
+    re.S)
+file_template = b'##file %(filename)s\n%(varname)s = convert("""\n%(data)s""")'
+
+def rebuild(script_path):
+    with open(script_path, 'rb') as f:
+        script_content = f.read()
+    parts = []
+    last_pos = 0
+    match = None
+    for match in file_regex.finditer(script_content):
+        parts += [script_content[last_pos:match.start()]]
+        last_pos = match.end()
+        filename, fn_decoded = match.group(1), match.group(1).decode()
+        varname = match.group(2)
+        data = match.group(3)
+
+        print('Found file %s' % fn_decoded)
+        pathname = os.path.join(here, '..', 'virtualenv_embedded', fn_decoded)
+
+        with open(pathname, 'rb') as f:
+            embedded = f.read()
+        new_crc = crc32(embedded)
+        new_data = b64.encode(gzip.encode(embedded)[0])[0]
+
+        if new_data == data:
+            print('  File up to date (crc: %s)' % new_crc)
+            parts += [match.group(0)]
+            continue
+        # Else: content has changed
+        crc = crc32(gzip.decode(b64.decode(data)[0])[0])
+        print('  Content changed (crc: %s -> %s)' %
+              (crc, new_crc))
+        new_match = file_template % {
+            b'filename': filename,
+            b'varname': varname,
+            b'data': new_data
+        }
+        parts += [new_match]
+
+    parts += [script_content[last_pos:]]
+    new_content = b''.join(parts)
+
+    if new_content != script_content:
+        print('Content updated; overwriting... ', end='')
+        with open(script_path, 'wb') as f:
+            f.write(new_content)
+        print('done.')
+    else:
+        print('No changes in content')
+    if match is None:
+        print('No variables were matched/found')
+
+if __name__ == '__main__':
+    rebuild(script)