Command line tool.

pbtools/__init__.py

@@ -1,2 +1,39 @@
+import sys
+import argparse
+
 from .parser import parse_file
 from .version import __version__
+
+__author__ = 'Erik Moqvist'
+
+
+def _main():
+    parser = argparse.ArgumentParser(
+        description='Various Google Protobuf utilities.')
+
+    parser.add_argument('-d', '--debug', action='store_true')
+    parser.add_argument('--version',
+                        action='version',
+                        version=__version__,
+                        help='Print version information and exit.')
+
+    # Workaround to make the subparser required in Python 3.
+    subparsers = parser.add_subparsers(title='subcommands',
+                                       dest='subcommand')
+    subparsers.required = True
+
+    # Import when used for less dependencies. For example, curses is
+    # not part of all Python builds.
+    from .subparsers import generate_c_source
+
+    generate_c_source.add_subparser(subparsers)
+
+    args = parser.parse_args()
+
+    if args.debug:
+        args.func(args)
+    else:
+        try:
+            args.func(args)
+        except BaseException as e:
+            sys.exit('error: ' + str(e))

pbtools/__main__.py

@@ -0,0 +1,5 @@
+# Execute as "python -m cantools"
+
+from . import _main as main
+
+main()

pbtools/c_source.py

@@ -0,0 +1,133 @@
+import re
+import time
+
+from .version import __version__
+
+
+HEADER_FMT = '''\
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Erik Moqvist
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * This file was generated by pbtools version {version} {date}.
+ */
+
+#ifndef {include_guard}
+#define {include_guard}
+
+#include <stdint.h>
+#include <stdbool.h>
+
+{structs}
+{declarations}
+#endif
+'''
+
+SOURCE_FMT = '''\
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Erik Moqvist
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * This file was generated by pbtools version {version} {date}.
+ */
+
+#include <string.h>
+
+#include "{header}"
+
+{helpers}
+{definitions}\
+'''
+
+
+def canonical(value):
+    """Replace anything but 'a-z', 'A-Z' and '0-9' with '_'.
+
+    """
+
+    return re.sub(r'[^a-zA-Z0-9]', '_', value)
+
+
+def camel_to_snake_case(value):
+    value = re.sub(r'(.)([A-Z][a-z]+)', r'\1_\2', value)
+    value = re.sub(r'(_+)', '_', value)
+    value = re.sub(r'([a-z0-9])([A-Z])', r'\1_\2', value).lower()
+    value = canonical(value)
+
+    return value
+
+
+def generate(namespace, parsed):
+    """Generate C source code from given parsed proto-file.
+
+    """
+
+    date = time.ctime()
+    namespace = camel_to_snake_case(namespace)
+    include_guard = '{}_H'.format(namespace.upper())
+
+    structs = ''
+    declarations = ''
+    header_name = ''
+    helpers = ''
+    definitions = ''
+
+    header = HEADER_FMT.format(version=__version__,
+                               date=date,
+                               include_guard=include_guard,
+                               structs=structs,
+                               declarations=declarations)
+
+    source = SOURCE_FMT.format(version=__version__,
+                               date=date,
+                               header=header_name,
+                               helpers=helpers,
+                               definitions=definitions)
+
+    return header, source

pbtools/subparsers/generate_c_source.py

@@ -0,0 +1,36 @@
+import os
+
+from ..parser import parse_file
+from ..c_source import camel_to_snake_case
+from ..c_source import generate
+
+
+def _do_generate_c_source(args):
+    parsed = parse_file(args.infile)
+
+    basename = os.path.basename(args.infile)
+    name = os.path.splitext(basename)[0]
+    name = camel_to_snake_case(name)
+
+    filename_h = f'{name}.h'
+    filename_c = f'{name}.c'
+
+    header, source = generate(name, parsed)
+
+    with open(filename_h, 'w') as fout:
+        fout.write(header)
+
+    with open(filename_c, 'w') as fout:
+        fout.write(source)
+
+    print('Successfully generated {} and {}.'.format(filename_h, filename_c))
+
+
+def add_subparser(subparsers):
+    generate_c_source_parser = subparsers.add_parser(
+        'generate_c_source',
+        description='Generate C source code from given protobuf file.')
+    generate_c_source_parser.add_argument(
+        'infile',
+        help='Input protobuf file.')
+    generate_c_source_parser.set_defaults(func=_do_generate_c_source)