nixpkgs/lib/sources.nix
Bas van Dijk 58ea28eb2c lib: allow sourceByRegex to be composed after cleanSourceWith
`sourceByRegex src regexes` should include a source file if one of the
regular expressions `regexes` matches the path of that file relative
to `src`.

However to compute this relative path `sourceByRegex` uses:

```
relPath = lib.removePrefix (toString src + "/") (toString path);
```

Note that `toString path` evaluates to an absolute file somewhere
under `src` and not under `/nix/store`.

The problem is that this doesn't work if `src` is a `cleanSourceWith`
invocation as well because `toString src` will then evaluate to
`src.outPath` which will evaluate to `builtins.filterSource ...` which
evaluates to a path in `/nix/store` which is not a prefix of `path`.

The solution is to replace `src` with `origSrc` where

```
origSrc = if isFiltered then src.origSrc else src;
isFiltered = src ? _isLibCleanSourceWith;
```

Test this by executing the following from the nixpkgs repo:

```
(cat << 'EOI'
let
  pkgs = import ./. {};
in pkgs.runCommand "test-sourceByRegex" {
  test_sourceByRegex =
    let
      src1 = pkgs.lib.sourceByRegex ./.  [ "^test-sourceByRegex.nix$" ];
      src2 = pkgs.lib.sourceByRegex src1 [ "^test-sourceByRegex.nix$" ];
    in src2 + "/test-sourceByRegex.nix";
} ''
 cp $test_sourceByRegex $out
''
EOI
) > test-sourceByRegex.nix
nix-build test-sourceByRegex.nix
```
2019-07-19 16:23:11 +02:00

108 lines
4.5 KiB
Nix

# Functions for copying sources to the Nix store.
{ lib }:
rec {
# Returns the type of a path: regular (for file), symlink, or directory
pathType = p: with builtins; getAttr (baseNameOf p) (readDir (dirOf p));
# Returns true if the path exists and is a directory, false otherwise
pathIsDirectory = p: if builtins.pathExists p then (pathType p) == "directory" 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 ||
builtins.match "^\\.sw[a-z]$" baseName != null ||
builtins.match "^\\..*\\.sw[a-z]$" 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 f (lib.cleanSourceWith g ./.) # Succeeds!
# builtins.filterSource f (builtins.filterSource g ./.) # Fails!
cleanSourceWith = { filter, src }:
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;
in {
inherit origSrc;
filter = filter';
outPath = builtins.filterSource filter' origSrc;
_isLibCleanSourceWith = true;
};
# 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: builtins.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; };
# Get the commit id of a git repo
# Example: commitIdFromGitRepo <nixpkgs/.git>
commitIdFromGitRepo =
let readCommitFromFile = file: path:
with builtins;
let fileName = toString path + "/" + file;
packedRefsName = toString path + "/packed-refs";
in if lib.pathExists fileName
then
let fileContent = lib.fileContents fileName;
# Sometimes git stores the commitId directly in the file but
# sometimes it stores something like: «ref: refs/heads/branch-name»
matchRef = match "^ref: (.*)$" fileContent;
in if matchRef == null
then fileContent
else readCommitFromFile (lib.head matchRef) path
# 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:
else if lib.pathExists packedRefsName
then
let fileContent = readFile packedRefsName;
matchRef = match (".*\n([^\n ]*) " + file + "\n.*") fileContent;
in if matchRef == null
then throw ("Could not find " + file + " in " + packedRefsName)
else lib.head matchRef
else throw ("Not a .git directory: " + path);
in readCommitFromFile "HEAD";
pathHasContext = builtins.hasContext or (lib.hasPrefix builtins.storeDir);
canCleanSource = src: src ? _isLibCleanSourceWith || !(pathHasContext (toString src));
}