utils: ipc: Add script to extract doxygen docs from mojom files

Add a script to extract doxygen documentation comments from mojom files.
It matches based on ^\/\*\*$ for start of block and ^ \*\/$ for end of
block, and simply copies the comments to the output file along with a
header and the libcamera namespace.

Also add it to the meson file so it is usable by other meson files.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Acked-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

utils/ipc/extract-docs.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (C) 2021, Google Inc.
+#
+# Author: Paul Elder <paul.elder@ideasonboard.com>
+#
+# extract-docs.py - Extract doxygen documentation from mojom files
+
+import argparse
+import re
+import sys
+
+regex_block_start = re.compile('^\/\*\*$')
+regex_block_end = re.compile('^ \*\/$')
+
+
+def main(argv):
+
+    # Parse command line arguments
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-o', dest='output', metavar='file',
+                        type=argparse.FileType('w', encoding='utf-8'),
+                        default=sys.stdout,
+                        help='Output file name (default: standard output)')
+    parser.add_argument('input', type=str,
+                        help='Input file name.')
+    args = parser.parse_args(argv[1:])
+
+    lines = open(args.input, 'r').readlines()
+    pipeline = args.input.split('/')[-1].replace('.mojom', '')
+    data = f'''\
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * {pipeline}_ipa_interface.cpp - Docs file for generated {pipeline}.mojom
+ *
+ * This file is auto-generated. Do not edit.
+ */
+
+namespace libcamera {{
+
+'''
+
+    in_block = False
+    comment = ''
+    for lineno, line in enumerate(lines, start=1):
+        if regex_block_start.match(line):
+            if in_block:
+                raise SyntaxError('Expected end of comment',
+                                  (args.input, lineno, 1, line))
+            in_block = True
+            comment = line
+            continue
+
+        if regex_block_end.match(line):
+            if in_block:
+                comment += line
+                data += comment + '\n'
+            in_block = False
+            continue
+
+        if in_block:
+            comment += line
+
+    data += '} /* namespace libcamera */\n'
+
+    args.output.write(data)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv))

utils/ipc/meson.build

@@ -8,6 +8,8 @@ mojom_parser = find_program('./parser.py')
 
 mojom_generator = find_program('./generate.py')
 
+mojom_docs_extractor = find_program('./extract-docs.py')
+
 mojom_templates = custom_target('mojom_templates',
                                 input : mojom_template_files,
                                 output : 'libcamera_templates.zip',