Componentize script to generate UI string overrides mapping.

components/variations/service/generate_ui_string_overrider.py

 #!/usr/bin/python
 # Copyright 2014 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.
 
+import argparse
 import collections
 import hashlib
 import operator
 import os
 import re
 import sys
 
-
+SCRIPT_NAME = "generate_ui_string_overrider.py"
 RESOURCE_EXTRACT_REGEX = re.compile('^#define (\S*) (\d*)$', re.MULTILINE)
 
 class Error(Exception):
   """Base error class for all exceptions in generated_resources_map."""
 
 
 class HashCollisionError(Error):
   """Multiple resource names hash to the same value."""
 
 
@@ skipping 92 matching lines @@
   lines = [entry_pattern % (data_getter(r), r.name) for r in resources]
   pattern = """const %(type)s %(name)s[] = {
 %(content)s
 };
 """
   return pattern % {'type': array_type,
                     'name': array_name,
                     'content': '\n'.join(lines)}
 
 
-def _GenerateFileContent(resources_content):
-  """Generates the .cc content from the given generated_resources.h content.
+def _GenerateSourceFileContent(resources_content, namespace, header_filename):
+  """Generates the .cc content from the given generated grit headers content.
 
   Args:
     resources_content: The input string to process, contains lines of the form
         "#define NAME INDEX".
 
+    namespace: The namespace in which the generated code should be scoped. If
+        not defined, then the code will be in the global namespace.
+
+    header_filename: Path to the corresponding .h.
+
   Returns:
-    .cc file content defining the kResourceHashes and kResourceIndices arrays.
+    .cc file content implementing the CreateUIStringOverrider() factory.
   """
   hashed_tuples = _GetResourceListFromString(resources_content)
 
   collisions = _CheckForHashCollisions(hashed_tuples)
   if collisions:
     error_message = "\n".join(
         ["hash: %i, name: %s" % (i[0], i[1]) for i in sorted(collisions)])
     error_message = ("\nThe following names had hash collisions "
                      "(sorted by the hash value):\n%s\n" %(error_message))
     raise HashCollisionError(error_message)
 
   hashes_array = _GenDataArray(
       hashed_tuples, "    %iU,  // %s", 'kResourceHashes', 'uint32_t',
       operator.attrgetter('hash'))
   indices_array = _GenDataArray(
       hashed_tuples, "    %s,  // %s", 'kResourceIndices', 'int',
       operator.attrgetter('index'))
 
+  namespace_prefix = ""
+  namespace_suffix = ""
+  if namespace:
+    namespace_prefix = "namespace %s {\n\n" % namespace
+    namespace_suffix = "\n}  // namespace %s\n" % namespace
+
   return (
-      "// This file was generated by generate_resources_map.py. Do not edit.\n"
-      "\n\n"
-      "#include "
-      "\"chrome/browser/metrics/variations/generated_resources_map.h\"\n\n"
-      "namespace chrome_variations {\n\n"
+      "// This file was generated by %s. Do not edit.\n"
+      "\n"
+      "#include \"%s\"\n\n"
+      "%s"
+      "namespace {\n\n"
       "const size_t kNumResources = %i;\n\n"
       "%s"
       "\n"
       "%s"
       "\n"
-      "}  // namespace chrome_variations\n") % (
-          len(hashed_tuples), hashes_array, indices_array)
+      "}  // namespace\n"
+      "\n"
+      "variations::UIStringOverrider CreateUIStringOverrider() {\n"
+      "  return variations::UIStringOverrider(\n"
+      "      kResourceHashes, kResourceIndices, kNumResources);\n"
+      "}\n"
+      "%s") % (

[jwd, 2015/09/29 15:02:54]

Can you use dictionary based string interpolation here. Easier to follow the
format with so many parameters.

[sdefresne, 2015/09/30 09:38:43]

Done.

+          SCRIPT_NAME, header_filename, namespace_prefix, len(hashed_tuples),
+          hashes_array, indices_array, namespace_suffix)
 
 
-def main(resources_file, map_file):
+def _GenerateHeaderFileContent(namespace, header_filename):
+  """Generates the .h for to the .cc generated by _GenerateSourceFileContent.
+
+  Args:
+    namespace: The namespace in which the generated code should be scoped. If
+        not defined, then the code will be in the global namespace.
+
+    header_filename: Path to the corresponding .h. Used to generate the include
+        guards.
+
+  Returns:
+    .cc file content implementing the CreateUIStringOverrider() factory.
+  """
+
+  include_guard = re.sub('[^A-Z]', '_', header_filename.upper()) + '_'
+
+  namespace_prefix = ""
+  namespace_suffix = ""
+  if namespace:
+    namespace_prefix = "namespace %s {\n\n" % namespace
+    namespace_suffix = "\n}  // namespace %s\n" % namespace
+
+  return (
+      "// This file was generated by %s. Do not edit.\n"
+      "\n"
+      "#ifndef %s\n"
+      "#define %s\n"
+      "\n"
+      "#include \"components/variations/service/ui_string_overrider.h\"\n\n"
+      "%s"
+      "// Returns an initialized UIStringOverrider.\n"
+      "variations::UIStringOverrider CreateUIStringOverrider();\n"
+      "%s"
+      "\n"
+      "#endif  // %s\n"

[jwd, 2015/09/29 15:02:54]

optional nit: use dictionary string interpolation instead of tuple.

[sdefresne, 2015/09/30 09:38:43]

Done.

+      ) % (
+          SCRIPT_NAME, include_guard, include_guard, namespace_prefix,
+          namespace_suffix, include_guard)
+
+
+def main():
+  arg_parser = argparse.ArgumentParser(
+      description="Generate UIStringOverrider factory from resources headers "
+                  "generated by grit.")
+  arg_parser.add_argument(
+      "--output_dir", "-o", required=True,
+      help="Base directory to for generated files.")
+  arg_parser.add_argument(
+      "--source_filename", "-S", required=True,
+      help="File name of the generated source file.")
+  arg_parser.add_argument(
+      "--header_filename", "-H", required=True,
+      help="File name of the generated header file.")
+  arg_parser.add_argument(
+      "--namespace", "-N", default="",
+      help="Namespace of the generated factory function (code will be in "
+           "the global namespace if this is omitted).")
+  arg_parser.add_argument(
+      "--test_support", "-t", action="store_true", default=False,
+      help="Make internal variables accessible for testing.")
+  arg_parser.add_argument(
+      "inputs", metavar="FILENAME", nargs="+",
+      help="Path to resources header file generated by grit.")
+  arguments = arg_parser.parse_args()
+
   generated_resources_h = ""
-  with open(resources_file, "r") as resources:
-    generated_resources_h = resources.read()
+  for resources_file in arguments.inputs:
+    with open(resources_file, "r") as resources:
+      generated_resources_h += resources.read()
 
   if len(generated_resources_h) == 0:
     raise Error("No content loaded for %s." % (resources_file))
 
-  file_content = _GenerateFileContent(generated_resources_h)
+  source_file_content = _GenerateSourceFileContent(
+      generated_resources_h, arguments.namespace, arguments.header_filename)
+  header_file_content = _GenerateHeaderFileContent(
+      arguments.namespace, arguments.header_filename)
 
-  with open(map_file, "w") as generated_file:
-    generated_file.write(file_content)
+  with open(os.path.join(
+      arguments.output_dir, arguments.source_filename), "w") as generated_file:
+    generated_file.write(source_file_content)
+  with open(os.path.join(
+      arguments.output_dir, arguments.header_filename), "w") as generated_file:
+    generated_file.write(header_file_content)
 
 
 if __name__ == '__main__':
-  sys.exit(main(sys.argv[1], sys.argv[2]))
+  sys.exit(main())