qapi-gen: Convert from getopt to argparse

argparse is nicer to use than getopt, and gives us --help almost for
free.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180211093607.27351-10-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
[eblake: Fix --output-dir editing accident]
Signed-off-by: Eric Blake <eblake@redhat.com>

scripts/qapi-gen.py

@@ -4,8 +4,11 @@
 # This work is licensed under the terms of the GNU GPL, version 2 or later.
 # See the COPYING file in the top-level directory.
 
+from __future__ import print_function
+import argparse
+import re
 import sys
-from qapi.common import parse_command_line, QAPISchema
+from qapi.common import QAPISchema
 from qapi.types import gen_types
 from qapi.visit import gen_visit
 from qapi.commands import gen_commands
@@ -15,26 +18,35 @@ from qapi.doc import gen_doc
 
 
 def main(argv):
-    (input_file, output_dir, prefix, opts) = \
-        parse_command_line('bu', ['builtins', 'unmask-non-abi-names'])
+    parser = argparse.ArgumentParser(
+        description='Generate code from a QAPI schema')
+    parser.add_argument('-b', '--builtins', action='store_true',
+                        help="generate code for built-in types")
+    parser.add_argument('-o', '--output-dir', action='store', default='',
+                        help="write output to directory OUTPUT_DIR")
+    parser.add_argument('-p', '--prefix', action='store', default='',
+                        help="prefix for symbols")
+    parser.add_argument('-u', '--unmask-non-abi-names', action='store_true',
+                        dest='unmask',
+                        help="expose non-ABI names in introspection")
+    parser.add_argument('schema', action='store')
+    args = parser.parse_args()
 
-    opt_builtins = False
-    opt_unmask = False
+    match = re.match(r'([A-Za-z_.-][A-Za-z0-9_.-]*)?', args.prefix)
+    if match.end() != len(args.prefix):
+        print("%s: 'funny character '%s' in argument of --prefix"
+              % (sys.argv[0], args.prefix[match.end()]),
+              file=sys.stderr)
+        sys.exit(1)
 
-    for o, a in opts:
-        if o in ('-b', '--builtins'):
-            opt_builtins = True
-        if o in ('-u', '--unmask-non-abi-names'):
-            opt_unmask = True
+    schema = QAPISchema(args.schema)
 
-    schema = QAPISchema(input_file)
-
-    gen_types(schema, output_dir, prefix, opt_builtins)
-    gen_visit(schema, output_dir, prefix, opt_builtins)
-    gen_commands(schema, output_dir, prefix)
-    gen_events(schema, output_dir, prefix)
-    gen_introspect(schema, output_dir, prefix, opt_unmask)
-    gen_doc(schema, output_dir, prefix)
+    gen_types(schema, args.output_dir, args.prefix, args.builtins)
+    gen_visit(schema, args.output_dir, args.prefix, args.builtins)
+    gen_commands(schema, args.output_dir, args.prefix)
+    gen_events(schema, args.output_dir, args.prefix)
+    gen_introspect(schema, args.output_dir, args.prefix, args.unmask)
+    gen_doc(schema, args.output_dir, args.prefix)
 
 
 if __name__ == '__main__':

scripts/qapi/common.py

@@ -13,7 +13,6 @@
 
 from __future__ import print_function
 import errno
-import getopt
 import os
 import re
 import string
@@ -1923,48 +1922,6 @@ def build_params(arg_type, boxed, extra):
     return ret
 
 
-#
-# Common command line parsing
-#
-
-
-def parse_command_line(extra_options='', extra_long_options=[]):
-
-    try:
-        opts, args = getopt.gnu_getopt(sys.argv[1:],
-                                       'p:o:' + extra_options,
-                                       ['prefix=', 'output-dir=']
-                                       + extra_long_options)
-    except getopt.GetoptError as err:
-        print("%s: %s" % (sys.argv[0], str(err)), file=sys.stderr)
-        sys.exit(1)
-
-    output_dir = ''
-    prefix = ''
-    extra_opts = []
-
-    for oa in opts:
-        o, a = oa
-        if o in ('-p', '--prefix'):
-            match = re.match(r'([A-Za-z_.-][A-Za-z0-9_.-]*)?', a)
-            if match.end() != len(a):
-                print("%s: 'funny character '%s' in argument of --prefix" \
-                      % (sys.argv[0], a[match.end()]), file=sys.stderr)
-                sys.exit(1)
-            prefix = a
-        elif o in ('-o', '--output-dir'):
-            output_dir = a + '/'
-        else:
-            extra_opts.append(oa)
-
-    if len(args) != 1:
-        print("%s: need exactly one argument" % sys.argv[0], file=sys.stderr)
-        sys.exit(1)
-    fname = args[0]
-
-    return (fname, output_dir, prefix, extra_opts)
-
-
 #
 # Accumulate and write output
 #