New C++ -> Java enum build rule + parser/generator.

build/android/gyp/enum_preprocess.py

Index: build/android/gyp/enum_preprocess.py
diff --git a/build/android/gyp/enum_preprocess.py b/build/android/gyp/enum_preprocess.py
new file mode 100755
index 0000000000000000000000000000000000000000..7f293e1ef202fe8a2e7adfbfb505454663d11d29
--- /dev/null
+++ b/build/android/gyp/enum_preprocess.py
@@ -0,0 +1,143 @@
+#!/usr/bin/env python
+#
+# Copyright 2013 The Chromium Authors. All rights reserved.

[Yaron, 2014/08/20 05:52:02]

2014

[mkosiba (inactive), 2014/09/02 16:00:57]

Done.

+# Use of this source code is governed by a BSD-style license that can be

[Yaron, 2014/08/20 05:52:02]

Please add tests.

[mkosiba (inactive), 2014/09/02 16:00:57]

Done.

+# found in the LICENSE file.
+
+import collections
+import re
+import optparse
+import os
+from string import Template
+import sys
+
+from util import build_utils
+
+def GetScriptName():
+  script_components = os.path.abspath(sys.argv[0]).split(os.path.sep)
+  build_index = script_components.index('build')
+  return os.sep.join(script_components[build_index:])
+
+def DoGenerate(options, path):
+  enum_entries = DoParseHeaderFile(path)
+  build_utils.MakeDirectory(os.path.dirname(options.output))
+  DoWriteOutput(options, enum_entries)
+
+def DoParseHeaderFile(path):
+  with open(path) as f:
+    lines = f.readlines()
+
+  single_line_comment_re = re.compile(r'\s*//')
+  multi_line_comment_start_re = re.compile(r'\s*/\*')
+  enum_start_re = re.compile(r'^\s*enum\s+(\w+)\s+{\s*$')
+  enum_line_re = re.compile(r'^\s*(\w+)(\s*\=\s*([^,]+))?,\s*$')
+  enum_end_re = re.compile(r'^\s*}\s*;\s*$')
+
+  in_enum = False
+  enum_name = None
+  enum_entries = collections.OrderedDict()
+
+  for line in lines:
+    if not in_enum:
+      enum_start = enum_start_re.match(line)
+      if enum_start:
+        if enum_name:
+          raise Exception('Only one enum per header file is supported.')

[Yaron, 2014/08/20 05:52:02]

Are there really no examples of this?

[mkosiba (inactive), 2014/09/02 16:00:57]

Done.

+        enum_name = enum_start.groups()[0]
+        in_enum = True
+    else:
+
+      if single_line_comment_re.match(line):
+        continue
+      if multi_line_comment_start_re.match(line):
+        raise Exception('Multi-line comments are not supported.')
+      enum_end = enum_end_re.match(line)
+      enum_entry = enum_line_re.match(line)
+      if enum_end:
+        in_enum = False
+      if enum_entry:
+        enum_key = enum_entry.groups()[0]
+        enum_value = enum_entry.groups()[2]
+        if enum_key in enum_entries:
+          raise Exception('Multiple definitions of key %s found.' % enum_key)
+        enum_entries[enum_key] = enum_value
+
+  all_entries_assigned = all(enum_entries.values())
+  any_entries_assigned = any(enum_entries.values())
+  if any_entries_assigned and not all_entries_assigned:
+    raise Exception('You either need to assign a value to all or none of the '
+                    'enum values.')
+
+  if not any_entries_assigned:
+    index = 0
+    for key in enum_entries.iterkeys():
+      enum_entries[key] = index
+      index = index + 1
+
+  return enum_entries
+
+
+def DoWriteOutput(options, enum_entries):
+  template = Template("""
+// 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.
+
+// This file is autogenerated by
+//     ${SCRIPT_NAME}
+// For
+//     ${PACKAGE}.${CLASS_NAME}
+
+package ${PACKAGE};
+
+public class ${CLASS_NAME} {
+${ENUM_ENTRIES}
+}
+""")
+
+  enum_template = Template("  public final int ${NAME} = ${VALUE},")
+  enum_entries_string = []
+  for enum_name, enum_value in enum_entries.iteritems():
+    values = {
+        'NAME': enum_name,
+        'VALUE': enum_value,
+    }
+    enum_entries_string.append(enum_template.substitute(values))
+  enum_entries_string = "\n".join(enum_entries_string)
+
+  values = {
+      'SCRIPT_NAME': GetScriptName(),
+      'PACKAGE': options.package.replace('/', '.'),
+      'CLASS_NAME': options.class_name,
+      'ENUM_ENTRIES': enum_entries_string,
+  }
+
+  with open(options.output, "w") as out_file:
+    out_file.write(template.substitute(values))
+
+
+def main():
+  parser = optparse.OptionParser()
+  build_utils.AddDepfileOption(parser)
+
+  parser.add_option('--output', help='Path for generated file.')
+  parser.add_option('--package', help='Package name.')
+  parser.add_option('--class_name', help='Class name.')
+  parser.add_option('--stamp', help='Path to touch on success.')
+  parser.add_option('--defines', help='Pre-defines macros', action='append')
+
+  options, args = parser.parse_args()
+
+  DoGenerate(options, args[0])
+
+  if options.depfile:
+    build_utils.WriteDepfile(
+        options.depfile,
+        build_utils.GetPythonDependencies())
+
+  if options.stamp:

[Yaron, 2014/08/20 05:52:02]

We have a definite output file. Why is a stamp necessary?

[mkosiba (inactive), 2014/09/02 16:00:57]

Done.

+    build_utils.Touch(options.stamp)
+
+
+if __name__ == '__main__':
+  sys.exit(main())