[Qemu-devel] [RFC PATCH 12/32] qapi: Use argparse to parse command line arguments

[Markus Armbruster]

Less code than with getopt, and we get --help for free.

Signed-off-by: Markus Armbruster <address@hidden>
---
 scripts/qapi-commands.py       | 13 +++++-----
 scripts/qapi-event.py          | 12 ++++-----
 scripts/qapi-introspect.py     | 22 +++++++---------
 scripts/qapi-types.py          | 22 ++++++----------
 scripts/qapi-visit.py          | 24 +++++++----------
 scripts/qapi.py                | 58 +++++++++++++++---------------------------
 scripts/qapi2texi.py           | 11 +++++---
 tests/qapi-schema/test-qapi.py | 10 +++++---
 8 files changed, 74 insertions(+), 98 deletions(-)

diff --git a/scripts/qapi-commands.py b/scripts/qapi-commands.py
index 56a1009564..76cc9cc8a4 100644
--- a/scripts/qapi-commands.py
+++ b/scripts/qapi-commands.py
@@ -214,7 +214,7 @@ void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds)
     QTAILQ_INIT(cmds);
 
 ''',
-                c_prefix=c_name(prefix, protect=False))
+                c_prefix=c_name(args.prefix, protect=False))
     ret += registry
     ret += mcgen('''
 }
@@ -253,7 +253,7 @@ class QAPISchemaGenCommandVisitor(QAPISchemaVisitor):
         self._regy += gen_register_command(name, success_response)
 
 
-(input_file, output_dir, prefix, opts) = parse_command_line()
+args = common_argument_parser().parse_args()
 
 c_comment = '''
 /*
@@ -284,7 +284,7 @@ h_comment = '''
  */
 '''
 
-(fdef, fdecl) = open_output(output_dir, prefix,
+(fdef, fdecl) = open_output(args.output_dir, args.prefix,
                             'qmp-marshal.c', 'qmp-commands.h',
                             c_comment, h_comment)
 
@@ -302,7 +302,7 @@ fdef.write(mcgen('''
 #include "%(prefix)sqmp-commands.h"
 
 ''',
-                 prefix=prefix))
+                 prefix=args.prefix))
 
 fdecl.write(mcgen('''
 #include "%(prefix)sqapi-types.h"
@@ -312,9 +312,10 @@ fdecl.write(mcgen('''
 
 void %(c_prefix)sqmp_init_marshal(QmpCommandList *cmds);
 ''',
-                  prefix=prefix, c_prefix=c_name(prefix, protect=False)))
+                  prefix=args.prefix,
+                  c_prefix=c_name(args.prefix, protect=False)))
 
-schema = QAPISchema(input_file)
+schema = QAPISchema(args.schema)
 gen = QAPISchemaGenCommandVisitor()
 schema.visit(gen)
 fdef.write(gen.defn)
diff --git a/scripts/qapi-event.py b/scripts/qapi-event.py
index 0a308e6b69..1c61751bc0 100644
--- a/scripts/qapi-event.py
+++ b/scripts/qapi-event.py
@@ -169,7 +169,7 @@ class QAPISchemaGenEventVisitor(QAPISchemaVisitor):
         self._event_names.append(name)
 
 
-(input_file, output_dir, prefix, dummy) = parse_command_line()
+args = common_argument_parser().parse_args()
 
 c_comment = '''
 /*
@@ -200,7 +200,7 @@ h_comment = '''
  */
 '''
 
-(fdef, fdecl) = open_output(output_dir, prefix,
+(fdef, fdecl) = open_output(args.output_dir, args.prefix,
                             'qapi-event.c', 'qapi-event.h',
                             c_comment, h_comment)
 
@@ -213,7 +213,7 @@ fdef.write(mcgen('''
 #include "qapi/qmp-event.h"
 
 ''',
-                 prefix=prefix))
+                 prefix=args.prefix))
 
 fdecl.write(mcgen('''
 #include "qapi/error.h"
@@ -222,11 +222,11 @@ fdecl.write(mcgen('''
 #include "%(prefix)sqapi-types.h"
 
 ''',
-                  prefix=prefix))
+                  prefix=args.prefix))
 
-event_enum_name = c_name(prefix + 'QAPIEvent', protect=False)
+event_enum_name = c_name(args.prefix + 'QAPIEvent', protect=False)
 
-schema = QAPISchema(input_file)
+schema = QAPISchema(args.schema)
 gen = QAPISchemaGenEventVisitor()
 schema.visit(gen)
 fdef.write(gen.defn)
diff --git a/scripts/qapi-introspect.py b/scripts/qapi-introspect.py
index c2e46182c8..ad87fc57e3 100644
--- a/scripts/qapi-introspect.py
+++ b/scripts/qapi-introspect.py
@@ -64,7 +64,7 @@ class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
         # generate C
         # TODO can generate awfully long lines
         jsons.extend(self._jsons)
-        name = c_name(prefix, protect=False) + 'qmp_schema_json'
+        name = c_name(args.prefix, protect=False) + 'qmp_schema_json'
         self.decl = mcgen('''
 extern const char %(c_name)s[];
 ''',
@@ -165,16 +165,12 @@ const char %(c_name)s[] = %(c_string)s;
         arg_type = arg_type or self._schema.the_empty_object_type
         self._gen_json(name, 'event', {'arg-type': self._use_type(arg_type)})
 
+parser = common_argument_parser()
 # Debugging aid: unmask QAPI schema's type names
 # We normally mask them, because they're not QMP wire ABI
-opt_unmask = False
-
-(input_file, output_dir, prefix, opts) = \
-    parse_command_line('u', ['unmask-non-abi-names'])
-
-for o, a in opts:
-    if o in ('-u', '--unmask-non-abi-names'):
-        opt_unmask = True
+parser.add_argument('-u', '--unmask-non-abi-names', action='store_true',
+                    help='unmask non-ABI names')
+args = parser.parse_args()
 
 c_comment = '''
 /*
@@ -199,7 +195,7 @@ h_comment = '''
  */
 '''
 
-(fdef, fdecl) = open_output(output_dir, prefix,
+(fdef, fdecl) = open_output(args.output_dir, args.prefix,
                             'qmp-introspect.c', 'qmp-introspect.h',
                             c_comment, h_comment)
 
@@ -208,10 +204,10 @@ fdef.write(mcgen('''
 #include "%(prefix)sqmp-introspect.h"
 
 ''',
-                 prefix=prefix))
+                 prefix=args.prefix))
 
-schema = QAPISchema(input_file)
-gen = QAPISchemaGenIntrospectVisitor(opt_unmask)
+schema = QAPISchema(args.schema)
+gen = QAPISchemaGenIntrospectVisitor(args.unmask_non_abi_names)
 schema.visit(gen)
 fdef.write(gen.defn)
 fdecl.write(gen.decl)
diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index dc7dd08512..ed05d828bf 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -185,7 +185,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
         self._fwdecl = None
         # To avoid header dependency hell, we always generate
         # declarations for built-in types in our header files and
-        # simply guard them.  See also do_builtins (command line
+        # simply guard them.  See also args.builtins (command line
         # option -b).
         self._btin += guardend('QAPI_TYPES_BUILTIN')
         self.decl = self._btin + self.decl
@@ -200,7 +200,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
         # TODO use something cleaner than existence of info
         if not info:
             self._btin += gen_enum(name, values, prefix)
-            if do_builtins:
+            if args.builtins:
                 self.defn += gen_enum_lookup(name, values, prefix)
         else:
             self._fwdecl += gen_enum(name, values, prefix)
@@ -211,7 +211,7 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
             self._btin += gen_fwd_object_or_array(name)
             self._btin += gen_array(name, element_type)
             self._btin += gen_type_cleanup_decl(name)
-            if do_builtins:
+            if args.builtins:
                 self.defn += gen_type_cleanup(name)
         else:
             self._fwdecl += gen_fwd_object_or_array(name)
@@ -239,16 +239,10 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
 
 # If you link code generated from multiple schemata, you want only one
 # instance of the code for built-in types.  Generate it only when
-# do_builtins, enabled by command line option -b.  See also
+# args.builtins, enabled by command line option -b.  See also
 # QAPISchemaGenTypeVisitor.visit_end().
-do_builtins = False
 
-(input_file, output_dir, prefix, opts) = \
-    parse_command_line('b', ['builtins'])
-
-for o, a in opts:
-    if o in ('-b', '--builtins'):
-        do_builtins = True
+args = common_argument_parser(builtins=True).parse_args()
 
 c_comment = '''
 /*
@@ -280,7 +274,7 @@ h_comment = '''
  */
 '''
 
-(fdef, fdecl) = open_output(output_dir, prefix,
+(fdef, fdecl) = open_output(args.output_dir, args.prefix,
                             'qapi-types.c', 'qapi-types.h',
                             c_comment, h_comment)
 
@@ -290,13 +284,13 @@ fdef.write(mcgen('''
 #include "%(prefix)sqapi-types.h"
 #include "%(prefix)sqapi-visit.h"
 ''',
-                 prefix=prefix))
+                 prefix=args.prefix))
 
 fdecl.write(mcgen('''
 #include "qapi/util.h"
 '''))
 
-schema = QAPISchema(input_file)
+schema = QAPISchema(args.schema)
 gen = QAPISchemaGenTypeVisitor()
 schema.visit(gen)
 fdef.write(gen.defn)
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 9757911d2d..010d68434f 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -276,7 +276,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
     def visit_end(self):
         # To avoid header dependency hell, we always generate
         # declarations for built-in types in our header files and
-        # simply guard them.  See also do_builtins (command line
+        # simply guard them.  See also args.builtins (command line
         # option -b).
         self._btin += guardend('QAPI_VISIT_BUILTIN')
         self.decl = self._btin + self.decl
@@ -287,7 +287,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
         # TODO use something cleaner than existence of info
         if not info:
             self._btin += gen_visit_decl(name, scalar=True)
-            if do_builtins:
+            if args.builtins:
                 self.defn += gen_visit_enum(name)
         else:
             self.decl += gen_visit_decl(name, scalar=True)
@@ -298,7 +298,7 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
         defn = gen_visit_list(name, element_type)
         if isinstance(element_type, QAPISchemaBuiltinType):
             self._btin += decl
-            if do_builtins:
+            if args.builtins:
                 self.defn += defn
         else:
             self.decl += decl
@@ -323,16 +323,10 @@ class QAPISchemaGenVisitVisitor(QAPISchemaVisitor):
 
 # If you link code generated from multiple schemata, you want only one
 # instance of the code for built-in types.  Generate it only when
-# do_builtins, enabled by command line option -b.  See also
+# args.builtins, enabled by command line option -b.  See also
 # QAPISchemaGenVisitVisitor.visit_end().
-do_builtins = False
 
-(input_file, output_dir, prefix, opts) = \
-    parse_command_line('b', ['builtins'])
-
-for o, a in opts:
-    if o in ('-b', '--builtins'):
-        do_builtins = True
+args = common_argument_parser(builtins=True).parse_args()
 
 c_comment = '''
 /*
@@ -363,7 +357,7 @@ h_comment = '''
  */
 '''
 
-(fdef, fdecl) = open_output(output_dir, prefix,
+(fdef, fdecl) = open_output(args.output_dir, args.prefix,
                             'qapi-visit.c', 'qapi-visit.h',
                             c_comment, h_comment)
 
@@ -373,7 +367,7 @@ fdef.write(mcgen('''
 #include "qapi/error.h"
 #include "%(prefix)sqapi-visit.h"
 ''',
-                 prefix=prefix))
+                 prefix=args.prefix))
 
 fdecl.write(mcgen('''
 #include "qapi/visitor.h"
@@ -381,9 +375,9 @@ fdecl.write(mcgen('''
 #include "%(prefix)sqapi-types.h"
 
 ''',
-                  prefix=prefix))
+                  prefix=args.prefix))
 
-schema = QAPISchema(input_file)
+schema = QAPISchema(args.schema)
 gen = QAPISchemaGenVisitVisitor()
 schema.visit(gen)
 fdef.write(gen.defn)
diff --git a/scripts/qapi.py b/scripts/qapi.py
index 5434987108..25f6c81b08 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -11,8 +11,8 @@
 # This work is licensed under the terms of the GNU GPL, version 2.
 # See the COPYING file in the top-level directory.
 
+import argparse
 import errno
-import getopt
 import os
 import re
 import string
@@ -1917,43 +1917,27 @@ def build_params(arg_type, boxed, extra):
 # Common command line parsing
 #
 
+def common_argument_parser(builtins=False):
 
-def parse_command_line(extra_options='', extra_long_options=[]):
+    def prefix(string):
+        match = re.match(r'([a-z_.-][a-z0-9_.-]*)?', string, re.I)
+        if match.end() != len(string):
+            raise argparse.ArgumentTypeError("funny character '%s'"
+                                             % string[match.end()])
+        return string
 
-    try:
-        opts, args = getopt.gnu_getopt(sys.argv[1:],
-                                       'chp:o:' + extra_options,
-                                       ['source', 'header', 'prefix=',
-                                        'output-dir='] + extra_long_options)
-    except getopt.GetoptError as err:
-        print >>sys.stderr, "%s: %s" % (sys.argv[0], str(err))
-        sys.exit(1)
+    parser = argparse.ArgumentParser(conflict_handler='resolve')
+    if builtins:
+        parser.add_argument('-b', '--builtins', action='store_true',
+                            help='generate builtins')
+    parser.add_argument('-o', '--output-dir', default='',
+                        help='output directory')
+    parser.add_argument('-p', '--prefix', default='', type=prefix,
+                        help='prefix to add to output files')
+    parser.add_argument('schema',
+                        help='QAPI schema source file')
+    return parser
 
-    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 >>sys.stderr, \
-                    "%s: 'funny character '%s' in argument of --prefix" \
-                    % (sys.argv[0], a[match.end()])
-                sys.exit(1)
-            prefix = a
-        elif o in ('-o', '--output-dir'):
-            output_dir = a + '/'
-        else:
-            extra_opts.append(oa)
-
-    if len(args) != 1:
-        print >>sys.stderr, "%s: need exactly one argument" % sys.argv[0]
-        sys.exit(1)
-    fname = args[0]
-
-    return (fname, output_dir, prefix, extra_opts)
 
 #
 # Generate output files with boilerplate
@@ -1963,8 +1947,8 @@ def parse_command_line(extra_options='', 
extra_long_options=[]):
 def open_output(output_dir, prefix, c_file, h_file,
                 c_comment, h_comment):
     guard = guardname(prefix + h_file)
-    c_file = output_dir + prefix + c_file
-    h_file = output_dir + prefix + h_file
+    c_file = os.path.join(output_dir, prefix + c_file)
+    h_file = os.path.join(output_dir, prefix + h_file)
 
     if output_dir:
         try:
diff --git a/scripts/qapi2texi.py b/scripts/qapi2texi.py
index bfd1c676e1..fd90d8953e 100755
--- a/scripts/qapi2texi.py
+++ b/scripts/qapi2texi.py
@@ -4,6 +4,8 @@
 # This work is licensed under the terms of the GNU LGPL, version 2+.
 # See the COPYING file in the top-level directory.
 """This script produces the documentation of a qapi schema in texinfo format"""
+
+import argparse
 import re
 import sys
 
@@ -279,11 +281,12 @@ def texi_schema(schema):
 
 def main(argv):
     """Takes schema argument, prints result to stdout"""
-    if len(argv) != 2:
-        print >>sys.stderr, "%s: need exactly 1 argument: SCHEMA" % argv[0]
-        sys.exit(1)
+    parser = argparse.ArgumentParser()
+    parser.add_argument('schema',
+                        help='QAPI schema source file')
+    args = parser.parse_args()
 
-    schema = qapi.QAPISchema(argv[1])
+    schema = qapi.QAPISchema(args.schema)
     if not qapi.doc_required:
         print >>sys.stderr, ("%s: need pragma 'doc-required' "
                              "to generate documentation" % argv[0])
diff --git a/tests/qapi-schema/test-qapi.py b/tests/qapi-schema/test-qapi.py
index fe0ca08d78..a7e21d016f 100644
--- a/tests/qapi-schema/test-qapi.py
+++ b/tests/qapi-schema/test-qapi.py
@@ -12,8 +12,7 @@
 
 from qapi import *
 from pprint import pprint
-import os
-import sys
+import argparse
 
 
 class QAPISchemaTestVisitor(QAPISchemaVisitor):
@@ -53,7 +52,12 @@ class QAPISchemaTestVisitor(QAPISchemaVisitor):
             for v in variants.variants:
                 print '    case %s: %s' % (v.name, v.type.name)
 
-schema = QAPISchema(sys.argv[1])
+parser = argparse.ArgumentParser()
+parser.add_argument('schema',
+                    help='QAPI schema source file')
+args = parser.parse_args()
+
+schema = QAPISchema(args.schema)
 schema.visit(QAPISchemaTestVisitor())
 
 for doc in schema.docs:
-- 
2.13.6