[PATCH] D50147: clang-format: support external styles

[Sam McCall via Phabricator via cfe-commits]

sammccall added a comment.

The idea here does seem to be a natural extension of -style, at least for the case when the arg is a filename directly. I'm not opposed, happy to review this.

I do want to probe the use case a bit though: we have found that configuring via -style= doesn't scale that well to lots of codebases and tools. e.g. if someone's running clang-tidy or clangd via some driver, are they going to have a way to plumb through the right -style=?

Being able to discover the right style from the filesystem is powerful, and if I was going to use this flag, I'd consider symlinking the style-file to `subproject/.clang_format` instead. That way the setting is persistent and available to all tools, rather than us needing to get it right on each invocation.



================
Comment at: lib/Format/Format.cpp:938
+  const llvm::SmallVector<Twine, 3> paths = {
+    {"/usr/local/share/clang-format/", Name},
+    {"~/.local/share/clang-format/", Name},
----------------
I'm not sure these prefixes are a good idea - can you explain what the purpose is, and why the simpler model of just using the path doesn't work?

Certainly this needs some more thought about how it would work on windows etc. I'd suggest limiting this patch to filenames.


Repository:
  rC Clang

https://reviews.llvm.org/D50147