1 files changed, 73 insertions, 0 deletions
diff --git a/utils/ipc/mojo/public/tools/bindings/concatenate_and_replace_closure_exports.py b/utils/ipc/mojo/public/tools/bindings/concatenate_and_replace_closure_exports.py
new file mode 100755
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+++ b/utils/ipc/mojo/public/tools/bindings/concatenate_and_replace_closure_exports.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+# Copyright 2018 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.
+
+"""Simple utility which concatenates a set of files into a single output file
+while also stripping any goog.provide or goog.require lines. This allows us to
+provide a very primitive sort of "compilation" without any extra toolchain
+support and without having to modify otherwise compilable sources in the tree
+which use these directives.
+
+goog.provide lines are replaced with an equivalent invocation of
+mojo.internal.exportModule, which accomplishes essentially the same thing in an
+uncompiled context. A singular exception is made for the 'mojo.internal' export,
+which is instead replaced with an inlined assignment to initialize the
+namespace.
+"""
+
+from __future__ import print_function
+
+import optparse
+import re
+
+
+_MOJO_INTERNAL_MODULE_NAME = "mojo.internal"
+_MOJO_EXPORT_MODULE_SYMBOL = "mojo.internal.exportModule"
+
+
+def FilterLine(filename, line, output):
+  if line.startswith("goog.require"):
+    return
+
+  if line.startswith("goog.provide"):
+    match = re.match("goog.provide\('([^']+)'\);", line)
+    if not match:
+      print("Invalid goog.provide line in %s:\n%s" % (filename, line))
+      exit(1)
+
+    module_name = match.group(1)
+    if module_name == _MOJO_INTERNAL_MODULE_NAME:
+      output.write("self.mojo = { internal: {} };")
+    else:
+      output.write("%s('%s');\n" % (_MOJO_EXPORT_MODULE_SYMBOL, module_name))
+    return
+
+  output.write(line)
+
+def ConcatenateAndReplaceExports(filenames):
+  if (len(filenames) < 2):
+    print("At least two filenames (one input and the output) are required.")
+    return False
+
+  try:
+    with open(filenames[-1], "w") as target:
+      for filename in filenames[:-1]:
+        with open(filename, "r") as current:
+          for line in current.readlines():
+            FilterLine(filename, line, target)
+    return True
+  except IOError as e:
+    print("Error generating %s\n: %s" % (filenames[-1], e))
+    return False
+
+def main():
+  parser = optparse.OptionParser()
+  parser.set_usage("""file1 [file2...] outfile
+    Concatenate several files into one, stripping Closure provide and
+    require directives along the way.""")
+  (_, args) = parser.parse_args()
+  exit(0 if ConcatenateAndReplaceExports(args) else 1)
+
+if __name__ == "__main__":
+  main()