Commit Graph

3 Commits

Author SHA1 Message Date
Ben Barham fe2478d44e [VFS] RedirectingFileSystem only replace path if not already mapped
If the `ExternalFS` has already remapped to an external path then
`RedirectingFileSystem` should not change it to the originally provided
path. This fixes the original path always being used if multiple VFS
overlays were provided and the path wasn't found in the highest (ie.
first in the chain).

For now this is accomplished through the use of a new
`ExposesExternalVFSPath` field on `vfs::Status`. This flag is true when
the `Status` has an external path that's different from its virtual
path, ie. the contained path is the external path. See the plan in
`FileManager::getFileRef` for where this is going - eventually we won't
need `IsVFSMapped` any more and all returned paths should be virtual.

Resolves rdar://90578880 and llvm-project#53306.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D123398
2022-04-11 14:52:48 -07:00
Ben Barham f65b0b5dcf Revert "[VFS] RedirectingFileSystem only replace path if not already mapped"
This reverts commit 3fda0edc51, which
breaks crash reproducers in very specific circumstances. Specifically,
since crash reproducers have `UseExternalNames` set to false, the
`File->getFileEntry().getDir()->getName()` call in `DoFrameworkLookup`
would use the *cached* directory name instead of the directory of the
looked-up file.

The plan is to re-commit this patch but to *add*
`ExposesExternalVFSPath` rather than replace `IsVFSMapped`.

Differential Revision: https://reviews.llvm.org/D123103
2022-04-05 14:24:40 -07:00
Ben Barham 3fda0edc51 [VFS] RedirectingFileSystem only replace path if not already mapped
If the `ExternalFS` has already remapped a path then the
`RedirectingFileSystem` should not change it to the originally provided
path. This fixes the original path always being used if multiple VFS
overlays were provided and the path wasn't found in the highest (ie.
first in the chain).

This also renames `IsVFSMapped` to `ExposesExternalVFSPath` and only
sets it if `UseExternalName` is true. This flag then represents that the
`Status` has an external path that's different from its virtual path.
Right now the contained path is still the external path, but further PRs
will change this to *always* be the virtual path. Clients that need the
external can then request it specifically.

Note that even though `ExposesExternalVFSPath` isn't set for all
VFS-mapped paths, `IsVFSMapped` was only being used by a hack in
`FileManager` that was specific to module searching. In that case
`UseExternalNames` is always `true` and so that hack still applies.

Resolves rdar://90578880 and llvm-project#53306.

Differential Revision: https://reviews.llvm.org/D122549
2022-03-30 11:52:41 -07:00