[PATCH] D65986: Allow setting the VFS to 'real' mode instead of default 'physical'

[Jonas Devlieghere via Phabricator via cfe-commits]

JDevlieghere added inline comments.


================
Comment at: clang/lib/Driver/Driver.cpp:172
+  case VFSMode::Unknown:
+    if (!this->VFS) {
+      LLVM_FALLTHROUGH;
----------------
jfb wrote:
> JDevlieghere wrote:
> > Is this really necessary? 
> the `Driver` ctor takes a `VFS` parameter which some tools set (otherwise it defaults to `nullptr`), so if the command-line `VFS` isn't specified we want to leave whatever was passed in as-is. If the command line parameter is set the we'll obey that instead.
> 
> So yes I think it's the right thing to do.
FWIW, I got confused by the indentation of the case element. Even though it's in the if-case it just acts like a label.  While clever, I think for the sake of readability it might be worth just repeating `this->VFS = llvm::vfs::createPhysicalFileSystem().release();`. 


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D65986/new/

https://reviews.llvm.org/D65986