Apply a common style to the main()s of locale database programs

Include documentation in both, using common phrasing. Take sys.argv as
a parameter, along with sys.stdout and sys.stderr, so that we can
invoke them from python when importing into a python session to debug
or test. Supply the script name to the argument parser as prog, so it
can correctly report it and forward the rest of argv to parse_args().
Remove comments anticipating one of the several calendars we don't yet
support; the existing entries suffice to make clear what shall be
needed when we get round to adding more.

Change-Id: I2cebd385679e3c84d4ccf899e60091ac823ad10d
Reviewed-by: Mate Barany <mate.barany@qt.io>

util/locale_database/cldr2qlocalexml.py

@@ -37,17 +37,25 @@ All the scripts mentioned support --help to tell you how to use them.
 """
 
 from pathlib import Path
-import sys
 import argparse
 
 from cldr import CldrReader
 from qlocalexml import QLocaleXmlWriter
 
 
-def main(out, err):
-    all_calendars = ['gregorian', 'persian', 'islamic']  # 'hebrew'
+def main(argv, out, err):
+    """Generate a QLocaleXML file from CLDR data.
+
+    Takes sys.argv, sys.stdout, sys.stderr (or equivalents) as
+    arguments. In argv[1:], it expects the root of the CLDR data
+    directory as first parameter and the name of the file in which to
+    save QLocaleXML data as second parameter. It accepts a --calendars
+    option to select which calendars to support (all available by
+    default)."""
+    all_calendars = ['gregorian', 'persian', 'islamic']
 
     parser = argparse.ArgumentParser(
+        prog=Path(argv[0]).name,
         description='Generate QLocaleXML from CLDR data.',
         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument('cldr_path', help='path to the root of the CLDR tree')
@@ -57,7 +65,7 @@ def main(out, err):
                         nargs='+', metavar='CALENDAR',
                         choices=all_calendars, default=all_calendars)
 
-    args = parser.parse_args()
+    args = parser.parse_args(argv[1:])
 
     root = Path(args.cldr_path)
     root_xml_path = 'common/main/root.xml'
@@ -90,4 +98,5 @@ def main(out, err):
     return 0
 
 if __name__ == '__main__':
-    sys.exit(main(sys.stdout, sys.stderr))
+    import sys
+    sys.exit(main(sys.argv, sys.stdout, sys.stderr))

util/locale_database/qlocalexml2cpp.py

@@ -521,17 +521,29 @@ class LocaleHeaderWriter (SourceFileEditor):
         out('\n    };\n')
 
 
-def main(out, err):
+def main(argv, out, err):
+    """Updates QLocale's CLDR data from a QLocaleXML file.
+
+    Takes sys.argv, sys.stdout, sys.stderr (or equivalents) as
+    arguments. In argv[1:] it expects the QLocaleXML file as first
+    parameter and the ISO 639-3 data table as second
+    parameter. Accepts the root of the qtbase checkout as third
+    parameter (default is inferred from this script's path) and a
+    --calendars option to select which calendars to support (all
+    available by default).
+
+    Updates various src/corelib/t*/q*_data_p.h files within the qtbase
+    checkout to contain data extracted from the QLocaleXML file."""
     calendars_map = {
         # CLDR name: Qt file name fragment
         'gregorian': 'roman',
         'persian': 'jalali',
         'islamic': 'hijri',
-        # 'hebrew': 'hebrew'
     }
     all_calendars = list(calendars_map.keys())
 
     parser = argparse.ArgumentParser(
+        prog=Path(argv[0]).name,
         description='Generate C++ code from CLDR data in QLocaleXML form.',
         formatter_class=argparse.ArgumentDefaultsHelpFormatter)
     parser.add_argument('input_file', help='input XML file name',
@@ -543,7 +555,7 @@ def main(out, err):
     parser.add_argument('--calendars', help='select calendars to emit data for',
                         nargs='+', metavar='CALENDAR',
                         choices=all_calendars, default=all_calendars)
-    args = parser.parse_args()
+    args = parser.parse_args(argv[1:])
 
     qlocalexml = args.input_file
     qtsrcdir = Path(args.qtbase_path)
@@ -624,4 +636,4 @@ def main(out, err):
 
 if __name__ == "__main__":
     import sys
-    sys.exit(main(sys.stdout, sys.stderr))
+    sys.exit(main(sys.argv, sys.stdout, sys.stderr))