locale_database: Use argparse module to parse command line arguments

arparse is the standard way to parse command line arguments in Python.
It provides help and usage information for free and is easier to extend
than a custom argument parser.

Task-number: QTBUG-83488
Pick-to: 6.2
Change-Id: I1e4c9cd914449e083d01932bc871ef10d26f0bc2
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 28 insertions, 21 deletions

diff --git a/util/locale_database/qlocalexml2cpp.py b/util/locale_database/qlocalexml2cpp.py
index e21577db9e..50a03dc9f3 100755
--- a/util/locale_database/qlocalexml2cpp.py
+++ b/util/locale_database/qlocalexml2cpp.py
@@ -26,15 +26,16 @@
 ## $QT_END_LICENSE$
 ##
 #############################################################################
-"""Script to generate C++ code from CLDR data in qLocaleXML form
+"""Script to generate C++ code from CLDR data in QLocaleXML form
 
-See ``cldr2qlocalexml.py`` for how to generate the qLocaleXML data itself.
+See ``cldr2qlocalexml.py`` for how to generate the QLocaleXML data itself.
 Pass the output file from that as first parameter to this script; pass
 the root of the qtbase check-out as second parameter.
 """
 
 import os
 import datetime
+import argparse
 
 from qlocalexml import QLocaleXmlReader
 from localetools import unicode2hex, wrap_list, Error, Transcriber, SourceFileEditor
@@ -498,30 +499,36 @@ class LocaleHeaderWriter (SourceFileEditor):
 
         out('\n    };\n')
 
-def usage(name, err, message = ''):
-    err.write(f"""Usage: {name} path/to/qlocale.xml root/of/qtbase
-""") # TODO: elaborate
-    if message:
-        err.write('\n' + message + '\n')
 
-def main(args, out, err):
-    # TODO: Make calendars a command-line parameter
+def main(out, err):
     # map { CLDR name: Qt file name }
-    calendars = {'gregorian': 'roman', 'persian': 'jalali', 'islamic': 'hijri',} # 'hebrew': 'hebrew',
-
-    name = args.pop(0)
-    if len(args) != 2:
-        usage(name, err, 'I expect two arguments')
-        return 1
-
-    qlocalexml = args.pop(0)
-    qtsrcdir = args.pop(0)
+    calendars_map = {
+        'gregorian': 'roman',
+        'persian': 'jalali',
+        'islamic': 'hijri',
+        # 'hebrew': 'hebrew'
+    }
+    all_calendars = list(calendars_map.keys())
+
+    parser = argparse.ArgumentParser(
+        description='Generate C++ code from CLDR data in QLocaleXML form.',
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+    parser.add_argument('input_file', help='input XML file name',
+                        metavar='input-file.xml')
+    parser.add_argument('qtbase_path', help='path to the root of the qtbase source tree')
+    parser.add_argument('--calendars', help='select calendars to emit data for',
+                        nargs='+', metavar='CALENDAR',
+                        choices=all_calendars, default=all_calendars)
+    args = parser.parse_args()
+
+    qlocalexml = args.input_file
+    qtsrcdir = args.qtbase_path
+    calendars = {cal: calendars_map[cal] for cal in args.calendars}
 
     if not (os.path.isdir(qtsrcdir)
             and all(os.path.isfile(os.path.join(qtsrcdir, 'src', 'corelib', 'text', leaf))
                     for leaf in ('qlocale_data_p.h', 'qlocale.h', 'qlocale.qdoc'))):
-        usage(name, err, f'Missing expected files under qtbase source root {qtsrcdir}')
-        return 1
+        parser.error(f'Missing expected files under qtbase source root {qtsrcdir}')
 
     reader = QLocaleXmlReader(qlocalexml)
     locale_map = dict(reader.loadLocaleMap(calendars, err.write))
@@ -617,4 +624,4 @@ def main(args, out, err):
 
 if __name__ == "__main__":
     import sys
-    sys.exit(main(sys.argv, sys.stdout, sys.stderr))
+    sys.exit(main(sys.stdout, sys.stderr))