[clang-tidy] Allow -warnings-as-errors to be specified from run_clang_tidy.py

[schaerfo]

Summary

This patch adds a -warnings-as-errors option to run_clang_tidy.py, which is forwarded to clang-tidy itself. This is done similar to the -header-filter option (as well as some others).

The rationale behind this is that previously, promoting warnings to errors when using run_clang_tidy was only possible through the .clang-tidy file and the -config option (which, however, overrides what is specified in .clang-tidy) and thus could not be changed without modifying this file. This comes in handy e. g. for CI, when you want the run to fail if certain warnings are emitted.

[njames93]

Just a general drive by comment, there have been quite a few patches recently that add arguments that just get forwarded straight to clang-tidy, would it not be a whole lot simpler if we could just automatically forward arguments straight to clang-tidy.
clang-tidy itself uses the -- argument to signify any arguments after that get forwarded to the clang driver, this script could probably do the same.
The whole invocation could be like this:
py run_clang_tidy.py <tool_args> -- <clang_tidy_options> -- <options_forwarded_to_clang>
So a general use case could look like this:
py run_clang_tidy.py -p ./compile_commands.json -quiet -- -check=-*,bugprone* -warnings-as-errors=* -- -UNDEBUG

Anyway aside from that, please upload diffs with the full context, see https://llvm.org/docs/Phabricator.html#phabricator-request-review-web for more info.

clang-tools-extra/clang-tidy/tool/run-clang-tidy.py

242

s/py/by

[schaerfo]

In D90535#2366731, @njames93 wrote:

Just a general drive by comment, there have been quite a few patches recently that add arguments that just get forwarded straight to clang-tidy, would it not be a whole lot simpler if we could just automatically forward arguments straight to clang-tidy.

That is indeed an idea worth considering, perhaps I can start working on it. It would, however, not be backwards compatible.

Anyway aside from that, please upload diffs with the full context, see https://llvm.org/docs/Phabricator.html#phabricator-request-review-web for more info.

I have updated the revision to show the entire diff.

clang-tools-extra/clang-tidy/tool/run-clang-tidy.py

 def make_absolute(f, directory):
   if os.path.isabs(f):
     return f
   return os.path.normpath(os.path.join(directory, f))
 
 
 def get_tidy_invocation(f, clang_tidy_binary, checks, tmpdir, build_path,
                         header_filter, allow_enabling_alpha_checkers,
-                        extra_arg, extra_arg_before, quiet, config):
+                        extra_arg, extra_arg_before, quiet, config,
+                        warnings_as_errors):
   """Gets a command line for clang-tidy."""
   start = [clang_tidy_binary]
   if allow_enabling_alpha_checkers:
     start.append('-allow-enabling-analyzer-alpha-checkers')
   if header_filter is not None:
     start.append('-header-filter=' + header_filter)
   if checks:
     start.append('-checks=' + checks)
   if tmpdir is not None:
     start.append('-export-fixes')
     # Get a temporary file. We immediately close the handle so clang-tidy can
     # overwrite it.
     (handle, name) = tempfile.mkstemp(suffix='.yaml', dir=tmpdir)
     os.close(handle)
     start.append(name)
   for arg in extra_arg:
       start.append('-extra-arg=%s' % arg)
   for arg in extra_arg_before:
       start.append('-extra-arg-before=%s' % arg)
   start.append('-p=' + build_path)
   if quiet:
       start.append('-quiet')
   if config:
       start.append('-config=' + config)
+  if warnings_as_errors:
+      start.append('-warnings-as-errors=' + warnings_as_errors)
   start.append(f)
   return start
 
 
 def merge_replacement_files(tmpdir, mergefile):
   """Merge all replacement files in a directory into a single file"""
   # The fixes suggested by clang-tidy >= 4.0.0 are given under
   # the top level key 'Diagnostics' in the output yaml files

 def run_tidy(args, tmpdir, build_path, queue, lock, failed_files):
   """Takes filenames out of queue and runs clang-tidy on them."""
   while True:
     name = queue.get()
     invocation = get_tidy_invocation(name, args.clang_tidy_binary, args.checks,
                                      tmpdir, build_path, args.header_filter,
                                      args.allow_enabling_alpha_checkers,
                                      args.extra_arg, args.extra_arg_before,
-                                     args.quiet, args.config)
+                                     args.quiet, args.config, args.warnings_as_errors)
 
     proc = subprocess.Popen(invocation, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
     output, err = proc.communicate()
     if proc.returncode != 0:
       failed_files.append(name)
     with lock:
       sys.stdout.write(' '.join(invocation) + '\n' + output.decode('utf-8'))
       if len(err) > 0:
parser.add_argument('-extra-arg', dest='extra_arg',
                       help='Additional argument to append to the compiler '
                       'command line.')
   parser.add_argument('-extra-arg-before', dest='extra_arg_before',
                       action='append', default=[],
                       help='Additional argument to prepend to the compiler '
                       'command line.')
   parser.add_argument('-quiet', action='store_true',
                       help='Run clang-tidy in quiet mode')
+  parser.add_argument('-warnings-as-errors', default=None,
+                      help='Upgrades warnings to errors. Does not enable '
+                      'any warnings py itself.')
   args = parser.parse_args()
 
   db_path = 'compile_commands.json'
 
   if args.build_path is not None:
     build_path = args.build_path
   else:
     # Find our database