tree deb3419389accd68d2f1cda721ef96398c958e5f
parent 7807ee1a10e2280d31c18c368e766dcf8676b5fe
author Aisha <87562264+aishasalim@users.noreply.github.com> 1786487988 -0500
committer Aisha <87562264+aishasalim@users.noreply.github.com> 1786487988 -0500

kythe: Add --output_path to write extracted facts to a file

The extractor could only write Kythe facts to stdout, so every caller had
to capture the stream, and a large project produces a lot of facts.

Add --output_path, which names a file to write the facts to. An empty
value or "-" keeps the current stdout behavior. The file is opened in
binary mode, because --print_kythe_facts=proto is not text. The tool
exits 1 when it cannot open the file.

All four print modes now share one std::ostream. To let the proto mode
join them, KytheProtoOutput takes a std::ostream and wraps it in an
OstreamOutputStream instead of taking a file descriptor.

Fixes #736.