Removed superfluous and slightly annoying newlines in run-clang-tidy's output.

[svenpanne]

Summary

The output of clang-tidy itself already has enough newlines, so the resulting output is more in line with the usual compiler output.

[JonasToth]

I agree with the direction, please ensure that e.g. clang-analyzer-* output looks proper as well and -quiet does, too.

[svenpanne]

In D61850#1500298, @JonasToth wrote:

[...] please ensure that e.g. clang-analyzer-* output looks proper as well and -quiet does, too.

OK, are there any (unit) tests which I should run? If yes, how exactly? I have a successfully built a fork of https://github.com/llvm/llvm-project via ninja locally, but the documentation for the various subprojects is still a bit hard to find to me. Is there a ninja target for clang-tidy-related tests? Any hints to get started would be highly appreciated.

This and the other output-related patches are my first submissions here, and they are intentionally simple to get the workflow right. My real intention is trying to improve/fix the readability-identifier-naming check/fixer, which still has a few issues.

[JonasToth]

In D61850#1500330, @svenpanne wrote:

In D61850#1500298, @JonasToth wrote:

[...] please ensure that e.g. clang-analyzer-* output looks proper as well and -quiet does, too.

OK, are there any (unit) tests which I should run? If yes, how exactly? I have a successfully built a fork of https://github.com/llvm/llvm-project via ninja locally, but the documentation for the various subprojects is still a bit hard to find to me. Is there a ninja target for clang-tidy-related tests? Any hints to get started would be highly appreciated.

This and the other output-related patches are my first submissions here, and they are intentionally simple to get the workflow right. My real intention is trying to improve/fix the readability-identifier-naming check/fixer, which still has a few issues.

There are testing targets for clang-tidy and clang-tooling, i believe ninja check-clang-tools is includes clang-tidy (maybe ninja check-clang-tooling instead).
If this script is actually covered by testing is not know to me, i believe not.
For testing just run it over a project (e.g. parts of LLVM) with this tool instead of e.g. your distribution version of it.

For general development: clang-tools-extra/test/clang-tidy/* has the test-cases for clang-tidy checks, which are real world code examples that cover all representative cases (in theory).

1. Write/adjust test
2. Do changes in code
3. Test with ninja check-clang-tools / ninja check-clang-tooling

That usually works. If you encounter any issues feel free to ask here/IRC/mail, we are happy to help out :)

[svenpanne]

I think ninja clang-test-tools is the right target here, and it is happy with the change, which is not very surprising: AFAICT, there is just a single, very simple check for run-clang-tidy.py. Anyway, my manual testing with and without -quiet shows no problems, either. Furthermore, we have a patched version with the above change in our CI for quite some time, and it works fine. And if I read the git history correctly, the output should be identical to the one before a fix for interleaved output was landed (that fix added the newlines somehow).

[JonasToth]

LGTM then, i can commit for you again?

[JonasToth]

Thans for the patch!

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

invocation = get_tidy_invocation(name, args.clang_tidy_binary, args.checks,
                                      args.extra_arg, args.extra_arg_before,
                                      args.quiet, args.config)
 
     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') + '\n')
+      sys.stdout.write(' '.join(invocation) + '\n' + output.decode('utf-8'))
       if len(err) > 0:
         sys.stdout.flush()
-        sys.stderr.write(err.decode('utf-8') + '\n')
+        sys.stderr.write(err.decode('utf-8'))
     queue.task_done()
 
 
 def main():
   parser = argparse.ArgumentParser(description='Runs clang-tidy over all files '
                                    'in a compilation database. Requires '
                                    'clang-tidy and clang-apply-replacements in '
                                    '$PATH.')