[Refactoring] Add a drop-in replacement for swift-refactor which checks that the code compiles after refactoring

Author: ahoppen

test/lit.cfg

@@ -334,6 +334,7 @@ config.scale_test = make_path(config.swift_utils, 'scale-test')
 config.PathSanitizingFileCheck = make_path(config.swift_utils, 'PathSanitizingFileCheck')
 config.swift_lib_dir = make_path(config.swift, '..', '..', 'lib')
 config.round_trip_syntax_test = make_path(config.swift_utils, 'round-trip-syntax-test')
+config.refactor_check_compiles = make_path(config.swift_utils, 'refactor-check-compiles.py')
 
 config.link = lit.util.which('link', config.environment.get('PATH', '')) or      \
               lit.util.which('lld-link', config.environment.get('PATH', ''))

test/refactoring/lit.local.cfg

@@ -2,4 +2,5 @@ if 'OS=macosx' not in config.available_features:
     config.unsupported = True
 
 else:
+    config.substitutions.append(('%refactor-check-compiles', '{} -swift-refactor {} -swift-frontend {} -temp-dir %t'.format(config.refactor_check_compiles, config.swift_refactor, config.swift_frontend)))
     config.substitutions.append(('%refactor', config.swift_refactor))

utils/refactor-check-compiles.py

@@ -0,0 +1,100 @@
+#!/usr/bin/env python
+from __future__ import print_function
+
+import argparse
+import os
+import subprocess
+import sys
+
+
+def run_cmd(cmd, desc):
+    try:
+        return subprocess.check_output(cmd)
+    except subprocess.CalledProcessError:
+        print('FAILED ' + desc + ':', file=sys.stderr)
+        print(' '.join(cmd), file=sys.stderr)
+        sys.exit(1)
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        description="""
+        A drop-in replacement for a 'swift-refactor -dump-text' call that
+        1. Checkes that the file still compiles after the refactoring by doing
+           'swift-refactor -dump-rewritten' and feeding the result to
+           'swift-frontend -typecheck'
+        2. Outputting the result of the 'swift-refactor -dump-text' call
+
+        All arguments other than the following will be forwarded to :
+        'swift-refactor':
+         - swift-frontend
+         - swift-refactor
+         - temp-dir
+        """)
+
+    parser.add_argument(
+        '-swift-frontend',
+        help='The path to the swift-frontend executable'
+    )
+    parser.add_argument(
+        '-swift-refactor',
+        help='The path to the swift-refactor executable'
+    )
+    parser.add_argument(
+        '-temp-dir',
+        help='A temporary directory to save the rewritten file in'
+    )
+    parser.add_argument(
+        '-dump-text',
+        action='store_true',
+        help='''
+        Required argument to indicate that the outputted text will be that of
+        swift-refactor -dump-text. This makes this script a drop-in replacement.
+        '''
+    )
+    parser.add_argument(
+        '-source-filename',
+        help='The file to refactor'
+    )
+    parser.add_argument(
+        '-pos',
+        help='The position to invoke the refactoring at'
+    )
+
+    return parser.parse_known_args()
+
+
+def main():
+    (args, unknown_args) = parse_args()
+    temp_file_name = os.path.split(args.source_filename)[-1] + '.' + \
+        args.pos.replace(':', '.')
+    temp_file_path = os.path.join(args.temp_dir, temp_file_name)
+    print(temp_file_path)
+    dump_text_output = run_cmd([
+        args.swift_refactor,
+        '-dump-text',
+        '-source-filename', args.source_filename,
+        '-pos', args.pos
+    ] + unknown_args, desc='producing edit')
+
+    dump_rewritten_output = run_cmd([
+        args.swift_refactor,
+        '-dump-rewritten',
+        '-source-filename', args.source_filename,
+        '-pos', args.pos
+    ] + unknown_args, desc='producing rewritten file')
+    with open(temp_file_path, 'wb') as f:
+        f.write(dump_rewritten_output)
+
+    run_cmd([
+        args.swift_frontend,
+        '-typecheck',
+        temp_file_path,
+        '-disable-availability-checking'
+    ], desc='checking that rewritten file compiles')
+    sys.stdout.write(dump_text_output)
+
+
+if __name__ == '__main__':
+    main()