[PATCH] D154130: [lit] Avoid os.path.realpath on Windows due to MAX_PATH limitations

[Tristan Labelle via Phabricator via cfe-commits]

MrTrillian added a comment.

> I took a look at the code and it looks to me like it would be safe to change ModuleMap::canonicalizeModuleMapPath() to use a drive preserving canonicalization

Symbolic links can point across drives so I think a drive preserving canonicalization cannot be much more than a conversion to an absolute path -- similar to the now renamed `abs_path_preserve_drive` I'm adding to lit. I think the logic would have to be split across Windows (only abs) and non-Windows (realpath) again. I also think a cache miss in this case is ok, so I will follow up with a clang change implementing this. Thanks!


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  https://reviews.llvm.org/D154130/new/

https://reviews.llvm.org/D154130