[PATCH] D41005: Reuse preamble even if an unsaved file does not exist

[Nikolai Kosjar via Phabricator via cfe-commits]

nik added a comment.

In https://reviews.llvm.org/D41005#1295632, @ilya-biryukov wrote:

> > Before this change, this was not a problem because OverriddenFiles were keyed on Status.getUniqueID(). Starting with this change, the key is the file path.
>
> I suggest keeping two maps for overridden files: one for existing files (key is UniqueID), another one for the ones that don't exist (key is the file path).


Done.

>> Is there a nice way to map different file paths of the same file to the same id without touching the real file system? Would it be sufficient to normalize the file paths? If yes, is there a utility function for this (can't find it right now).
> 
> I don't think there is one, the unique ids are closely tied to the filesystem. IIUC the unique ids are the same whenever two different paths are symlinks (or hardlinks?) pointing to the same physical file and there's no way to tell if they're the same without resolving the symlink.

OK, so if the unsaved file is not being backed up by a real file on disk and symlinks are used, we can't do much about it.
I've normalized the file paths to handle at least that case where they might differ.


Repository:
  rC Clang

https://reviews.llvm.org/D41005