# Functions for copying sources to the Nix store. { lib }: # Tested in lib/tests/sources.sh let inherit (builtins) match readDir split storeDir tryEval ; inherit (lib) boolToString filter getAttr isString pathExists readFile ; /* Returns the type of a path: regular (for file), symlink, or directory. */ pathType = path: getAttr (baseNameOf path) (readDir (dirOf path)); /* Returns true if the path exists and is a directory, false otherwise. */ pathIsDirectory = path: if pathExists path then (pathType path) == "directory" else false; /* Returns true if the path exists and is a regular file, false otherwise. */ pathIsRegularFile = path: if pathExists path then (pathType path) == "regular" else false; /* A basic filter for `cleanSourceWith` that removes directories of version control system, backup files (*~) and some generated files. */ cleanSourceFilter = name: type: let baseName = baseNameOf (toString name); in ! ( # Filter out version control software files/directories (baseName == ".git" || type == "directory" && (baseName == ".svn" || baseName == "CVS" || baseName == ".hg")) || # Filter out editor backup / swap files. lib.hasSuffix "~" baseName || match "^\\.sw[a-z]$" baseName != null || match "^\\..*\\.sw[a-z]$" baseName != null || # Filter out generates files. lib.hasSuffix ".o" baseName || lib.hasSuffix ".so" baseName || # Filter out nix-build result symlinks (type == "symlink" && lib.hasPrefix "result" baseName) || # Filter out sockets and other types of files we can't have in the store. (type == "unknown") ); /* Filters a source tree removing version control files and directories using cleanSourceFilter. Example: cleanSource ./. */ cleanSource = src: cleanSourceWith { filter = cleanSourceFilter; inherit src; }; /* Like `builtins.filterSource`, except it will compose with itself, allowing you to chain multiple calls together without any intermediate copies being put in the nix store. Example: lib.cleanSourceWith { filter = f; src = lib.cleanSourceWith { filter = g; src = ./.; }; } # Succeeds! builtins.filterSource f (builtins.filterSource g ./.) # Fails! */ cleanSourceWith = { # A path or cleanSourceWith result to filter and/or rename. src, # Optional with default value: constant true (include everything) # The function will be combined with the && operator such # that src.filter is called lazily. # For implementing a filter, see # https://nixos.org/nix/manual/#builtin-filterSource # Type: A function (path -> type -> bool) filter ? _path: _type: true, # Optional name to use as part of the store path. # This defaults to `src.name` or otherwise `"source"`. name ? null }: let orig = toSourceAttributes src; in fromSourceAttributes { inherit (orig) origSrc; filter = path: type: filter path type && orig.filter path type; name = if name != null then name else orig.name; }; /* Add logging to a source, for troubleshooting the filtering behavior. Type: sources.trace :: sourceLike -> Source */ trace = # Source to debug. The returned source will behave like this source, but also log its filter invocations. src: let attrs = toSourceAttributes src; in fromSourceAttributes ( attrs // { filter = path: type: let r = attrs.filter path type; in builtins.trace "${attrs.name}.filter ${path} = ${boolToString r}" r; } ) // { satisfiesSubpathInvariant = src ? satisfiesSubpathInvariant && src.satisfiesSubpathInvariant; }; /* Filter sources by a list of regular expressions. Example: src = sourceByRegex ./my-subproject [".*\.py$" "^database.sql$"] */ sourceByRegex = src: regexes: let isFiltered = src ? _isLibCleanSourceWith; origSrc = if isFiltered then src.origSrc else src; in lib.cleanSourceWith { filter = (path: type: let relPath = lib.removePrefix (toString origSrc + "/") (toString path); in lib.any (re: match re relPath != null) regexes); inherit src; }; /* Get all files ending with the specified suffices from the given source directory or its descendants, omitting files that do not match any suffix. The result of the example below will include files like `./dir/module.c` and `./dir/subdir/doc.xml` if present. Type: sourceLike -> [String] -> Source Example: sourceFilesBySuffices ./. [ ".xml" ".c" ] */ sourceFilesBySuffices = # Path or source containing the files to be returned src: # A list of file suffix strings exts: let filter = name: type: let base = baseNameOf (toString name); in type == "directory" || lib.any (ext: lib.hasSuffix ext base) exts; in cleanSourceWith { inherit filter src; }; pathIsGitRepo = path: (_commitIdFromGitRepoOrError path)?value; /* Get the commit id of a git repo. Example: commitIdFromGitRepo <nixpkgs/.git> */ commitIdFromGitRepo = path: let commitIdOrError = _commitIdFromGitRepoOrError path; in commitIdOrError.value or (throw commitIdOrError.error); # Get the commit id of a git repo. # Returns `{ value = commitHash }` or `{ error = "... message ..." }`. # Example: commitIdFromGitRepo <nixpkgs/.git> # not exported, used for commitIdFromGitRepo _commitIdFromGitRepoOrError = let readCommitFromFile = file: path: let fileName = path + "/${file}"; packedRefsName = path + "/packed-refs"; absolutePath = base: path: if lib.hasPrefix "/" path then path else toString (/. + "${base}/${path}"); in if pathIsRegularFile path # Resolve git worktrees. See gitrepository-layout(5) then let m = match "^gitdir: (.*)$" (lib.fileContents path); in if m == null then { error = "File contains no gitdir reference: " + path; } else let gitDir = absolutePath (dirOf path) (lib.head m); commonDir'' = if pathIsRegularFile "${gitDir}/commondir" then lib.fileContents "${gitDir}/commondir" else gitDir; commonDir' = lib.removeSuffix "/" commonDir''; commonDir = absolutePath gitDir commonDir'; refFile = lib.removePrefix "${commonDir}/" "${gitDir}/${file}"; in readCommitFromFile refFile commonDir else if pathIsRegularFile fileName # Sometimes git stores the commitId directly in the file but # sometimes it stores something like: «ref: refs/heads/branch-name» then let fileContent = lib.fileContents fileName; matchRef = match "^ref: (.*)$" fileContent; in if matchRef == null then { value = fileContent; } else readCommitFromFile (lib.head matchRef) path else if pathIsRegularFile packedRefsName # Sometimes, the file isn't there at all and has been packed away in the # packed-refs file, so we have to grep through it: then let fileContent = readFile packedRefsName; matchRef = match "([a-z0-9]+) ${file}"; isRef = s: isString s && (matchRef s) != null; # there is a bug in libstdc++ leading to stackoverflow for long strings: # https://github.com/NixOS/nix/issues/2147#issuecomment-659868795 refs = filter isRef (split "\n" fileContent); in if refs == [] then { error = "Could not find " + file + " in " + packedRefsName; } else { value = lib.head (matchRef (lib.head refs)); } else { error = "Not a .git directory: " + toString path; }; in readCommitFromFile "HEAD"; pathHasContext = builtins.hasContext or (lib.hasPrefix storeDir); canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src)); # -------------------------------------------------------------------------- # # Internal functions # # toSourceAttributes : sourceLike -> SourceAttrs # # Convert any source-like object into a simple, singular representation. # We don't expose this representation in order to avoid having a fifth path- # like class of objects in the wild. # (Existing ones being: paths, strings, sources and x//{outPath}) # So instead of exposing internals, we build a library of combinator functions. toSourceAttributes = src: let isFiltered = src ? _isLibCleanSourceWith; in { # The original path origSrc = if isFiltered then src.origSrc else src; filter = if isFiltered then src.filter else _: _: true; name = if isFiltered then src.name else "source"; }; # fromSourceAttributes : SourceAttrs -> Source # # Inverse of toSourceAttributes for Source objects. fromSourceAttributes = { origSrc, filter, name }: { _isLibCleanSourceWith = true; inherit origSrc filter name; outPath = builtins.path { inherit filter name; path = origSrc; }; }; in { inherit pathType pathIsDirectory pathIsRegularFile pathIsGitRepo commitIdFromGitRepo cleanSource cleanSourceWith cleanSourceFilter pathHasContext canCleanSource sourceByRegex sourceFilesBySuffices trace ; }