nixpkgs/lib/sources.nix
Léo Gaspard 144a997c8e
lib: fix commitIdFromGitRepo (#117752)
When in the presence of worktrees, it happens that /commondir has a
trailing slash.

In these circumstances, it can lead to `lib.pathType` being passed paths
like `/foo/bar/.git/`, which in turn lead to
`error: attribute '.git' missing`.

With this change, we now make sure send properly-formatted paths to all
other functions.

This, in particular, fixes running NixOS tests on worktrees created by
libgit2 on my machine. (Worktrees created by git itself appear to not
hit the issue.)
2021-03-27 21:16:31 +01:00

181 lines
7 KiB
Nix

# Functions for copying sources to the Nix store.
{ lib }:
let
inherit (builtins)
hasContext
match
readDir
split
storeDir
tryEval
;
inherit (lib)
filter
getAttr
isString
pathExists
readFile
;
in
rec {
# Returns the type of a path: regular (for file), symlink, or directory
pathType = p: getAttr (baseNameOf p) (readDir (dirOf p));
# Returns true if the path exists and is a directory, false otherwise
pathIsDirectory = p: if pathExists p then (pathType p) == "directory" else false;
# Returns true if the path exists and is a regular file, false otherwise
pathIsRegularFile = p: if pathExists p then (pathType p) == "regular" else false;
# Bring in a path as a source, filtering out all Subversion and CVS
# directories, as well as backup 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)
);
# Filters a source tree removing version control files and directories using cleanSourceWith
#
# 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.
#
# lib.cleanSourceWith {
# filter = f;
# src = lib.cleanSourceWith {
# filter = g;
# src = ./.;
# };
# }
# # Succeeds!
#
# builtins.filterSource f (builtins.filterSource g ./.)
# # Fails!
#
# Parameters:
#
# src: A path or cleanSourceWith result to filter and/or rename.
#
# filter: A function (path -> type -> bool)
# 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
#
# name: Optional name to use as part of the store path.
# This defaults to `src.name` or otherwise `"source"`.
#
cleanSourceWith = { filter ? _path: _type: true, src, name ? null }:
let
isFiltered = src ? _isLibCleanSourceWith;
origSrc = if isFiltered then src.origSrc else src;
filter' = if isFiltered then name: type: filter name type && src.filter name type else filter;
name' = if name != null then name else if isFiltered then src.name else "source";
in {
inherit origSrc;
filter = filter';
outPath = builtins.path { filter = filter'; path = origSrc; name = name'; };
_isLibCleanSourceWith = true;
name = name';
};
# Filter sources by a list of regular expressions.
#
# E.g. `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
# directory or its descendants. E.g. `sourceFilesBySuffices ./dir
# [".xml" ".c"]'.
sourceFilesBySuffices = path: 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 = path; };
pathIsGitRepo = path: (tryEval (commitIdFromGitRepo path)).success;
# Get the commit id of a git repo
# Example: commitIdFromGitRepo <nixpkgs/.git>
commitIdFromGitRepo =
let readCommitFromFile = file: path:
let fileName = toString path + "/" + file;
packedRefsName = toString 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: (.*)$" (lib.fileContents path);
in if m == null
then throw ("File contains no gitdir reference: " + path)
else
let gitDir = absolutePath (dirOf path) (lib.head m);
commonDir'' = if pathIsRegularFile "${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 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 throw ("Could not find " + file + " in " + packedRefsName)
else lib.head (matchRef (lib.head refs))
else throw ("Not a .git directory: " + path);
in readCommitFromFile "HEAD";
pathHasContext = builtins.hasContext or (lib.hasPrefix storeDir);
canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src));
}