diff options
Diffstat (limited to 'lib/fileset/internal.nix')
-rw-r--r-- | lib/fileset/internal.nix | 60 |
1 files changed, 59 insertions, 1 deletions
diff --git a/lib/fileset/internal.nix b/lib/fileset/internal.nix index d55c84a395e70..717253f45715b 100644 --- a/lib/fileset/internal.nix +++ b/lib/fileset/internal.nix @@ -167,7 +167,12 @@ rec { else value else if ! isPath value then - if isStringLike value then + if value ? _isLibCleanSourceWith then + throw '' + ${context} is a `lib.sources`-based value, but it should be a file set or a path instead. + To convert a `lib.sources`-based value to a file set you can use `lib.fileset.fromSource`. + Note that this only works for sources created from paths.'' + else if isStringLike value then throw '' ${context} ("${toString value}") is a string-like value, but it should be a file set or a path instead. Paths represented as strings are not supported by `lib.fileset`, use `lib.sources` or derivations instead.'' @@ -470,6 +475,59 @@ rec { else nonEmpty; + # Turn a builtins.filterSource-based source filter on a root path into a file set + # containing only files included by the filter. + # The filter is lazily called as necessary to determine whether paths are included + # Type: Path -> (String -> String -> Bool) -> fileset + _fromSourceFilter = root: sourceFilter: + let + # During the recursion we need to track both: + # - The path value such that we can safely call `readDir` on it + # - The path string value such that we can correctly call the `filter` with it + # + # While we could just recurse with the path value, + # this would then require converting it to a path string for every path, + # which is a fairly expensive operation + + # Create a file set from a directory entry + fromDirEntry = path: pathString: type: + # The filter needs to run on the path as a string + if ! sourceFilter pathString type then + null + else if type == "directory" then + fromDir path pathString + else + type; + + # Create a file set from a directory + fromDir = path: pathString: + mapAttrs + # This looks a bit funny, but we need both the path-based and the path string-based values + (name: fromDirEntry (path + "/${name}") (pathString + "/${name}")) + # We need to readDir on the path value, because reading on a path string + # would be unspecified if there are multiple filesystem roots + (readDir path); + + rootPathType = pathType root; + + # We need to convert the path to a string to imitate what builtins.path calls the filter function with. + # We don't want to rely on `toString` for this though because it's not very well defined, see ../path/README.md + # So instead we use `lib.path.splitRoot` to safely deconstruct the path into its filesystem root and subpath + # We don't need the filesystem root though, builtins.path doesn't expose that in any way to the filter. + # So we only need the components, which we then turn into a string as one would expect. + rootString = "/" + concatStringsSep "/" (components (splitRoot root).subpath); + in + if rootPathType == "directory" then + # We imitate builtins.path not calling the filter on the root path + _create root (fromDir root rootString) + else + # Direct files are always included by builtins.path without calling the filter + # But we need to lift up the base path to its parent to satisfy the base path invariant + _create (dirOf root) + { + ${baseNameOf root} = rootPathType; + }; + # Transforms the filesetTree of a file set to a shorter base path, e.g. # _shortenTreeBase [ "foo" ] (_create /foo/bar null) # => { bar = null; } |