Ignore block comments in JNI generator.

base/android/jni_generator/jni_generator.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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.
 
 # TODO (qinmin): Need to refactor this file as base should not know about
 # higher level concepts. Currently this file has knowledge about higher level
 # java classes.
 
 """Extracts native methods from a Java file and generates the JNI bindings.
@@ skipping 433 matching lines @@
     natives = ExtractNatives(contents)
     called_by_natives = ExtractCalledByNatives(contents)
     if len(natives) == 0 and len(called_by_natives) == 0:
       raise SyntaxError('Unable to find any JNI methods for %s.' %
                         fully_qualified_class)
     inl_header_file_generator = InlHeaderFileGenerator(
         jni_namespace, fully_qualified_class, natives, called_by_natives)
     self.content = inl_header_file_generator.GetContent()
 
   def _RemoveComments(self, contents):
-    ret = []
-    for c in [c.strip() for c in contents.split('\n')]:
-      if not c.startswith('//'):
-        ret += [c]
-    return '\n'.join(ret)
+    # We need to support both inline and block comments, and we need to handle
+    # strings that contain '//' or '/*'. Rather than trying to do all that with
+    # regexps, we just pipe the contents through the C preprocessor. We tell cpp
+    # the file has already been preprocessed, so it just removes comments and
+    # doesn't try to parse #include, #pragma etc.
+    #
+    # TODO(husky): This is a bit hacky. It would be cleaner to use a real Java
+    # parser. Maybe we could ditch JNIFromJavaSource and just always use
+    # JNIFromJavaP; or maybe we could rewrite this script in Java and use APT.
+    # http://code.google.com/p/chromium/issues/detail?id=138941
+    p = subprocess.Popen(args=['cpp', '-fpreprocessed'],
+                         stdin=subprocess.PIPE,
+                         stdout=subprocess.PIPE,
+                         stderr=subprocess.PIPE)
+    stdout, _ = p.communicate(contents)
+    return stdout
 
   def GetContent(self):
     return self.content
 
   @staticmethod
   def CreateFromFile(java_file_name):
     contents = file(java_file_name).read()
     fully_qualified_class = ExtractFullyQualifiedJavaClassName(java_file_name,
                                                                contents)
     return JNIFromJavaSource(contents, fully_qualified_class)
@@ skipping 494 matching lines @@
     input_file = options.input_file
   output_file = None
   if options.output_dir:
     root_name = os.path.splitext(os.path.basename(input_file))[0]
     output_file = os.path.join(options.output_dir, root_name) + '_jni.h'
   GenerateJNIHeader(input_file, output_file, options.namespace)
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))