[PATCH] D57533: lit: support long paths on Windows

[Saleem Abdulrasool via Phabricator via llvm-commits]

compnerd added a comment.

@ruiu - to your point of "it being better in the future" I think is false hope.  The backwards API compatibility will prevent Microsoft from changing the behaviour of the APIs without an explicit opt-in.  Otherwise, applications need to be rewritten, which has long been the case, you can use the NT style paths all the way back to Windows XP I believe, but applications aren't being rebuilt and redistributed.

As to the cases I am hitting?  It is primarily the use of `%t` from lit and the module cache path in the swift test suite.  Personally, I think changing those to return short paths is the wrong approach.  But, if that seems to shrink the path enough to permit parallel builds, I can probably live with that.  I think that of the 251 characters, we should reserve at least `\Users\????????\swift-source\build\Ninja-RelWithDebInfoAssert\swift-windows-x86_64` as a prefix because that is going to be pretty common ... which doesn't leave you with much space to play with.


Repository:
  rL LLVM

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  https://reviews.llvm.org/D57533/new/

https://reviews.llvm.org/D57533