Add Python flow to bindings generation, move dummy-generating IDL files over

Source/bindings/scripts/idl_compiler.py

+#!/usr/bin/python
+# Copyright (C) 2013 Google Inc. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Compile an .idl file to Blink V8 bindings (.h and .cpp files).
+
+We are porting the IDL compiler from Perl to Python. The plan is as follows.
+We will temporarily have two build flows (see ../derived_sources.gyp):
+[1] Perl: deprecated_generate_bindings.pl, which calls:
+    deprecated_idl_parser.pm => deprecated_code_generator_v8.pm
+[2] Python: idl_compiler.py, which calls:
+    IDL lexer => IDL parser => Python object builder =>
+    interface dependency resolver => IDL semantic validator =>
+    C++ code generator
+
+We will move IDL files from the Perl build flow [1] to the Python build flow [2]
+incrementally.
+First we will land the build changes and idl_compiler.py (in one CL).
+Next we will land all Python files except the code generator (in one CL),
+which reads all IDL files.
+Finally we will incrementally land the code generator (in several CLs),
+moving IDL files to the Python build flow as the code generator is completed.

[haraken, 2013/07/10 06:22:48]

I'd remove the part from "First we will...". You can explain the plan in a bug
and add a link to the bug. (I'm sorry that the criteria for where to add how
much comments is ambiguous. Basically, we prefer to being concise rather than
verbose, since we really want to avoid the situation where comments become
out-dated.)

[Nils Barth (inactive), 2013/07/10 07:04:11]

Done, at the tracker bug:
Issue 239771: Rewrite the IDL compiler in Python
http://crbug.com/239771#c37
No problem – I understand it's a balancing act.

I'll try to make sure time-sensitive comments ("We're going to do X.")
only occur exactly where the change will occur!

+"""
+import optparse
+import os
+import shlex
+import sys
+
+import idl_reader
+import code_generator_v8
+
+
+def parse_options():
+    parser = optparse.OptionParser()
+    parser.add_option('--additional-idl-files')
+    parser.add_option('--idl-attributes-file')
+    parser.add_option('--include', dest='idl_directories', action='append')
+    parser.add_option('--output-directory')
+    parser.add_option('--interface-dependencies-file')
+    parser.add_option('--verbose', action='store_true', default=False)
+    parser.add_option('--write-file-only-if-changed', type='int')
+    # ensure output comes last, so command line easy to parse via regexes
+    parser.disable_interspersed_args()
+
+    options, args = parser.parse_args()
+    if options.output_directory is None:
+        parser.error('Must specify output directory using --output-directory.')
+    if options.additional_idl_files is not None:
+        # additional_idl_files is passed as a string with varied (shell-style)
+        # quoting, hence needs parsing.
+        options.additional_idl_files = shlex.split(options.additional_idl_files)
+    if len(args) != 1:
+        parser.error('Must specify exactly 1 input file as argument, but %d given.' % len(args))
+    options.idl_filename = os.path.realpath(args[0])
+    return options
+
+
+def main():
+    options = parse_options()
+    idl_filename = options.idl_filename
+    basename = os.path.basename(idl_filename)
+    interface_name, _ = os.path.splitext(basename)
+    verbose = options.verbose
+    if verbose:
+        print idl_filename
+
+    idl_document = idl_reader.read_idl_interface(idl_filename, options.interface_dependencies_file, options.additional_idl_files)
+    # FIXME: add parameters when add validator
+    # idl_document = idl_reader.read_idl_interface(idl_filename, options.interface_dependencies_file, options.additional_idl_files, options.idl_attributes_file, verbose=verbose)
+    if not idl_document:
+        # We generate dummy .h and .cpp files just to tell build scripts
+        # that outputs have been created.
+        code_generator_v8.generate_dummy_header_and_cpp(interface_name, options.output_directory)
+        return
+    # FIXME: turn on code generator
+    # Currently idl_document must be None (so dummy .h and .cpp files are
+    # generated), as actual code generator not present yet.
+    # code_generator_v8.write_interface(idl_document, interface_name, options.output_directory)
+    raise RuntimeError('Stub: code generator not implemented yet')
+
+
+if __name__ == '__main__':
+    sys.exit(main())