Add reStructuredText generator to gdbus-codegen

The gdbus-codegen tool generates documentation from the XML introspection
description of a D-Bus interface. Currently, only DocBook is supported at
the moment, but not every modern documentation generator can handle that
format. The reStructuredText format is a bit more well-supported,
especially in documentation generators for non-C languages.

Unlike DocBook, we get to make our own structure and conventions for how
we structure the documentation when using reStructuredText.

gio/gdbus-2.0/codegen/codegen_main.py

@@ -30,6 +30,7 @@ from . import dbustypes
 from . import parser
 from . import codegen
 from . import codegen_docbook
+from . import codegen_rst
 from .utils import print_error, print_warning
 
 
@@ -211,6 +212,11 @@ def codegen_main():
         metavar="OUTFILES",
         help="Generate Docbook in OUTFILES-org.Project.IFace.xml",
     )
+    arg_parser.add_argument(
+        "--generate-rst",
+        metavar="OUTFILES",
+        help="Generate reStructuredText in OUTFILES-org.Project.IFace.rst",
+    )
     arg_parser.add_argument(
         "--pragma-once",
         action="store_true",
@@ -287,10 +293,12 @@ def codegen_main():
         )
 
     if (
-        args.generate_c_code is not None or args.generate_docbook is not None
+        args.generate_c_code is not None
+        or args.generate_docbook is not None
+        or args.generate_rst is not None
     ) and args.output is not None:
         print_error(
-            "Using --generate-c-code or --generate-docbook and "
+            "Using --generate-c-code or --generate-docbook or --generate-rst and "
             "--output at the same time is not allowed"
         )
 
@@ -420,6 +428,11 @@ def codegen_main():
     if docbook:
         docbook_gen.generate(docbook, args.output_directory)
 
+    rst = args.generate_rst
+    rst_gen = codegen_rst.RstCodeGenerator(all_ifaces)
+    if rst:
+        rst_gen.generate(rst, args.output_directory)
+
     if args.header:
         with open(h_file, "w") as outfile:
             gen = codegen.HeaderCodeGenerator(