[clang-tidy] New argument --language to add_new_check.py

[benhamilton]

Summary

Currently, add_new_check.py assumes all checks are for C++ code.

This adds a new argument --language=[LANG] to add_new_check.py
so authors of new checks can specify that the test file should
be in a different language.

For example, authors can pass --language=objc for Objective-C
clang-tidy checks.

[alexfh]

A higher-level option - language (maybe with an optional standard, e.g. c++11 or c11) - would probably be more useful, since we could also use it to modify the template of the check to bail out on other languages.

[benhamilton]

A higher-level option - language (maybe with an optional standard, e.g. c++11 or c11) - would probably be more useful, since we could also use it to modify the template of the check to bail out on other languages.

I like that — is there a list of all the language options I can steal here?

[benhamilton]

• Use --language flag instead, support c, c++, objc, objc++

[benhamilton]

Went ahead and did that, supporting c, c++, objc, objc++.

[alexfh]

clang-tidy/add_new_check.py

345–352 ↗

(On Diff #119715)

Should this be done in write_test instead?

[Wizard]

clang-tidy/add_new_check.py

310 ↗

(On Diff #119715)

If we are using this flag, do we need to somehow explicitly pass the language arg when run clang-tidy towards files?

[alexfh]

clang-tidy/add_new_check.py

310 ↗

(On Diff #119715)

The intention is that this flag instructs the script to create the test file with the corresponding extension, and the check_clang_tidy.py script we use for testing (and the clang-tidy tool itself) will detect the language based on the extension.

Does it answer your question?

[Wizard]

clang-tidy/add_new_check.py

310 ↗

(On Diff #119715)

My bad. Did not notice that this flag is only for adding a new check.

[benhamilton]

• @alexfh: Move language -> test extension map into write_test()

[alexfh]

clang-tidy/add_new_check.py

227–234 ↗

(On Diff #119852)

Just noticed: the list of the languages is also used in the documentation of the corresponding option below. Maybe make this a map of language -> extension and feed its keys to the choices argument of parser.add_argument?

Sorry for not noticing this earlier.

[benhamilton]

• @alexfh: Move language -> test extension map into a dict, use keys to specify arg

[benhamilton]

BTW, it'd be nice to get an accept, @alexfh !

[alexfh]

LG. Sorry, this got lost under my vacation heap of mail.

clang-tools-extra/trunk/clang-tidy/add_new_check.py

 #!/usr/bin/env python
 #
 #===- add_new_check.py - clang-tidy check generator ----------*- python -*--===#
 #
 #                     The LLVM Compiler Infrastructure
 #
 # This file is distributed under the University of Illinois Open Source
 # License. See LICENSE.TXT for details.
 #
 #===------------------------------------------------------------------------===#
 
+import argparse
 import os
 import re
 import sys
 
 
 # Adapts the module's CMakelist file. Returns 'True' if it could add a new entry
 # and 'False' if the entry already existed.
 def adapt_cmake(module_path, check_name_camel):
- New `%s
   FIXME: add release notes.
 """ % (check_name_dashes, check_name_dashes))
             note_added = True
 
       f.write(line)
 
 
 # Adds a test for the check.
-def write_test(module_path, module, check_name):
+def write_test(module_path, module, check_name, test_extension):
   check_name_dashes = module + '-' + check_name
   filename = os.path.normpath(os.path.join(module_path, '../../test/clang-tidy',
-                                           check_name_dashes + '.cpp'))
+                                           check_name_dashes + '.' + test_extension))
   print('Creating %s...' % filename)
   with open(filename, 'wb') as f:
     f.write("""// RUN: %%check_clang_tidy %%s %(check_name_dashes)s %%t
 
 // FIXME: Add something that triggers the check here.
 void f();
 // CHECK-MESSAGES: :[[@LINE-1]]:6: warning: function 'f' is insufficiently awesome [%(check_name_dashes)s]
 

 %(underline)s
 
 FIXME: Describe what patterns does the check detect and why. Give examples.
 """ % {'check_name_dashes': check_name_dashes,
        'underline': '=' * len(check_name_dashes)})
 
 
 def main():
-  if len(sys.argv) == 2 and sys.argv[1] == '--update-docs':
-    update_checks_list(os.path.dirname(sys.argv[0]))
-    return
-
-  if len(sys.argv) != 3:
-    print """\
-Usage: add_new_check.py <module> <check>, e.g.
-  add_new_check.py misc awesome-functions
-
-Alternatively, run 'add_new_check.py --update-docs' to just update the list of
-documentation files."""
+  language_to_extension = {
+      'c': 'c',
+      'c++': 'cpp',
+      'objc': 'm',
+      'objc++': 'mm',
+  }
+  parser = argparse.ArgumentParser()
+  parser.add_argument(
+      '--update-docs',
+      action='store_true',
+      help='just update the list of documentation files, then exit')
+  parser.add_argument(
+      '--language',
+      help='language to use for new check (defaults to c++)',
+      choices=language_to_extension.keys(),
+      default='c++',
+      metavar='LANG')
+  parser.add_argument(
+      'module',
+      help='module directory under which to place the new tidy check (e.g., misc)')
+  parser.add_argument(
+      'check',
+      help='name of new tidy check to add (e.g. foo-do-the-stuff)')
+  args = parser.parse_args()
 
+  if args.update_docs:
+    update_checks_list(os.path.dirname(sys.argv[0]))
     return
 
-  module = sys.argv[1]
-  check_name = sys.argv[2]
+  module = args.module
+  check_name = args.check
 
   if check_name.startswith(module):
     print 'Check name "%s" must not start with the module "%s". Exiting.' % (
         check_name, module)
     return
   check_name_camel = ''.join(map(lambda elem: elem.capitalize(),
                                  check_name.split('-'))) + 'Check'
   clang_tidy_path = os.path.dirname(sys.argv[0])
   module_path = os.path.join(clang_tidy_path, module)
 
   if not adapt_cmake(module_path, check_name_camel):
     return
   write_header(module_path, module, check_name, check_name_camel)
   write_implementation(module_path, module, check_name_camel)
   adapt_module(module_path, module, check_name, check_name_camel)
   add_release_notes(module_path, module, check_name)
-  write_test(module_path, module, check_name)
+  test_extension = language_to_extension.get(args.language)
+  write_test(module_path, module, check_name, test_extension)
   write_docs(module_path, module, check_name)
   update_checks_list(clang_tidy_path)
   print('Done. Now it\'s your turn!')
 
 
 if __name__ == '__main__':
   main()