[PATCH] D42642: [CUDA] Detect installation in PATH

[Michael Kruse via llvm-commits]

An update:

I just re-tried creating a symbolic link from inside wsl on drvfs
(case 2). It now created a symlink just as "mklink" does. What might
have changed is that I updated to a newer insider preview or that I
enabled developer mode when I tried the first time.

[1] seems to apply for case 1. [2] has a nice overview about what can
happen here.

Michael

[1] https://github.com/libgit2/libgit2/pull/4713
[2] https://stackoverflow.com/questions/11662868/what-happens-when-i-clone-a-repository-with-symlinks-on-windows

Am Do., 2. Mai 2019 um 10:17 Uhr schrieb Alexandre Ganea
<alexandre.ganea at ubisoft.com>:
>
> Thanks Michael, it makes sense. I'm still with the old SVN setup on Windows. WSL uses the NTFS partition through drvfs (your case 2.)
> I'll switch to the git monorepo, it looks like the latest git supports [1] symlinks on Windows (with the restrictions you've mentioned) and they should be mapped properly inside WSL in that case.
>
> Should we then assume symlinks will always work for end-users? Should we validate that somehow, during cmake setup?
>
> Alex.
>
> [1] https://github.com/libgit2/libgit2/pull/4713
>
> -----Message d'origine-----
> De : Michael Kruse <llvm-commits at meinersbur.de>
> Envoyé : 1 mai 2019 17:23
> À : reviews+D42642+public+5dc9c99d2f2d3f57 at reviews.llvm.org; Alexandre Ganea via Phabricator <reviews at reviews.llvm.org>
> Cc : hahnjo at hahnjo.de; jlebar at google.com; tra at google.com; Alexandre Ganea <alexandre.ganea at ubisoft.com>; cfe-commits <cfe-commits at lists.llvm.org>; llvm-commits <llvm-commits at lists.llvm.org>; sylvestre.ledru at gmail.com
> Objet : Re: [PATCH] D42642: [CUDA] Detect installation in PATH
>
> Hi,
>
> I had my own difficulties with this. It depends on how the repository
> containing the symlink has been checked-out. For instance:
>
> 1. Using a windows git (such as git extensions, mingw-git, git for windows)
> 2. Using git inside wsl on a drvfs mount (i.e. a windows folder
> mounted into the Unix filesystem)
> 3. Using git inside wsl on a lxfs mount (I.e. native mount such as '/')
>
> In case 1. git does not create a Ubuntu symlink. Also, there are no
> Unix symlinks in Windows filesystems, so when Unix tools (such as git)
> request to create a symlink, it creates something else (AFAIR it's a
> text file containing the symlink path, but having lost its symlink
> properties). Case 3 should work.
>
> I still managed to make cases 1 and 2 work by deleting the text file
> and re-creating it with windows's "mklink" tool (which requires either
> admin rights or developer mode turned on). It seems the WSL layer
> translates this as a symlink to the Linux environment.
>
> Michael
>
>
>
>
>
> Am Mi., 1. Mai 2019 um 16:59 Uhr schrieb Alexandre Ganea via
> Phabricator via llvm-commits <llvm-commits at lists.llvm.org>:
> >
> > aganea added a subscriber: rnk.
> > aganea added a comment.
> >
> > So it turns out this is a symlink issue. The file `clang/trunk/test/Driver/Inputs/CUDA-symlinks/usr/bin/ptxas` has been synchronized on my Windows 10 PC as a regular text file, not a symlink. It looks like TortoiseSVN doesn't implement symlinks. As WSL inherits of my file system, it will not find the symbolic link. I suppose `REQUIRES: !system-windows` isn't enough for `cuda-detect-path.cu`, and it would need something like `REQUIRES: symlinks` along with support in lit. @rnk
> >
> >
> > Repository:
> >   rL LLVM
> >
> > CHANGES SINCE LAST ACTION
> >   https://reviews.llvm.org/D42642/new/
> >
> > https://reviews.llvm.org/D42642
> >
> >
> >
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