# Functions for copying sources to the Nix store.

{ lib }:

# Tested in lib/tests/sources.sh

let

inherit (lib.strings)

match

split

storeDir

escapeRegex

removePrefix

;

inherit (lib)

boolToString

filter

isString

readFile

concatStrings

length

elemAt

isList

any

;

inherit (lib.filesystem)

pathIsRegularFile

;

/**

A basic filter for `cleanSourceWith` that removes

directories of version control system, backup files (`*~`)

and some generated files.

# Inputs

`name`

: 1\. Function argument

`type`

: 2\. Function argument

*/

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"

|| baseName == ".jj"

|| baseName == ".pijul"

|| baseName == "_darcs"

)

)

||

# 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`.

# Inputs

`src`

: 1\. Function argument

# Examples

:::{.example}

## `cleanSource` usage example

```nix

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.

# Examples

:::{.example}

## `cleanSourceWith` usage example

```nix

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.

# Inputs

`src`

: Source to debug. The returned source will behave like this source, but also log its filter invocations.

# 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.

# Inputs

`src`

: 1\. Function argument

`regexes`

: 2\. Function argument

# Examples

:::{.example}

## `sourceByRegex` usage example

```nix

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.

# Inputs

`src`

: Path or source containing the files to be returned

`exts`

: A list of file suffix strings

# Type

```

sourceFilesBySuffices :: SourceLike -> [String] -> Source

```

# Examples

:::{.example}

## `sourceFilesBySuffices` usage example

```nix

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.

# Inputs

`path`

: 1\. Function argument

# Examples

:::{.example}

## `commitIdFromGitRepo` usage example

```nix

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 if lib.hasPrefix "/" base then

"${base}/${path}"

else

"/${base}/${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;

};

};

# urlToName : (URL | Path | String) -> String

#

# Transform a URL (or path, or string) into a clean package name.

urlToName =

url:

let

inherit (lib.strings) stringLength;

base = baseNameOf (lib.removeSuffix "/" (lib.last (lib.splitString ":" (toString url))));

# chop away one git or archive-related extension

removeExt =

name:

let

matchExt = match "(.*)\\.(git|tar|zip|gz|tgz|bz|tbz|bz2|tbz2|lzma|txz|xz|zstd)$" name;

in

if matchExt != null then lib.head matchExt else name;

# apply function f to string x while the result shrinks

shrink =

f: x:

let

v = f x;

in

if stringLength v < stringLength x then shrink f v else x;

in

shrink removeExt base;

# shortRev : (String | Integer) -> String

#

# Given a package revision (like "refs/tags/v12.0"), produce a short revision ("12.0").

shortRev =

rev:

let

baseRev = baseNameOf (toString rev);

matchHash = match "[a-f0-9]+" baseRev;

matchVer = match "([A-Za-z]+[-_. ]?)*(v)?([0-9.]+.*)" baseRev;

in

if matchHash != null then

builtins.substring 0 7 baseRev

else if matchVer != null then

lib.last matchVer

else

baseRev;

# revOrTag : String -> String -> String

#

# Turn git `rev` and `tag` pair into a revision usable in `repoRevToName*`.

revOrTag =

rev: tag:

if tag != null then

tag

else if rev != null then

rev

else

"HEAD";

# repoRevToNameFull : (URL | Path | String) -> (String | Integer | null) -> (String | null) -> String

#

# See `repoRevToName` below.

repoRevToNameFull =

repo_: rev_: suffix_:

let

repo = urlToName repo_;

rev = if rev_ != null then "-${shortRev rev_}" else "";

suffix = if suffix_ != null then "-${suffix_}" else "";

in

"${repo}${rev}${suffix}-source";

# repoRevToName : String -> (URL | Path | String) -> (String | Integer | null) -> String -> String

#

# Produce derivation.name attribute for a given repository URL/path/name and (optionally) its revision/version tag.

#

# This is used by fetch(zip|git|FromGitHub|hg|svn|etc) to generate discoverable

# /nix/store paths.

#

# This uses a different implementation depending on the `pretty` argument:

# "source" -> name everything as "source"

# "versioned" -> name everything as "${repo}-${rev}-source"

# "full" -> name everything as "${repo}-${rev}-${fetcher}-source"

repoRevToName =

kind:

# match on `kind` first to minimize the thunk

if kind == "source" then

(

repo: rev: suffix:

"source"

)

else if kind == "versioned" then

(

repo: rev: suffix:

repoRevToNameFull repo rev null

)

else if kind == "full" then

repoRevToNameFull

else

throw "repoRevToName: invalid kind";

/**

Filter a source tree by a list of doublestar-style glob patterns,

returning a source that only contains paths matching at least one

pattern. `*` matches a single path component, and `**` matches any

number of components.

# Inputs

`src`

: The source tree to filter.

`patterns`

: List of glob patterns to include, e.g. `[ "*.py" "src/**" ]`.

A leading `**` (e.g. `**\/*.py` for all `.py` files at any depth)

is also supported; the `\` here is just a Nix string escape used

to avoid closing this comment.

# Examples

:::{.example}

## `sourceByGlobs` usage example

- Include everything under a subdirectory

```nix

src = sourceByGlobs ./. [ "src/**" "tests/**" ]

```

- Include all .py files in root directory only

```nix

src = sourceByGlobs ./. [ "*.py" ]

```

:::

*/

sourceByGlobs =

let

splitPath = path: filter isString (split "/" path);

# Make component regex

mkRe =

s:

if s == "**" then

".*" # Has special handling below

else

concatStrings (map (tok: if isList tok then "[^/]*" else escapeRegex tok) (split "\\*+" s));

# Make a source filter function from pattern

mkMatcher =

pat:

let

globs = map mkRe (splitPath pat);

glen = length globs;

in

path: type:

let

path' = splitPath path;

plen = length path';

recurse =

gi: pi:

let

g = elemAt globs gi;

p = elemAt path' pi;

m = match g p != null;

in

if pi >= plen then # Reached end of path

gi >= glen || (type == "directory" || type == "symlink") # Only allow partial matches for directories

else if gi >= glen then # Reached end of globs

false

else if g == ".*" then # Special handling for **

(

# Lookahead for next glob match

if (gi + 1) == glen then

true

else if (match (elemAt globs (gi + 1)) p != null) then

recurse (gi + 1) pi

else if m then

recurse gi (pi + 1)

else

false

)

else if m then

recurse (gi + 1) (pi + 1)

else

false;

in

recurse 0 0;

mkSourceFilter =

root: patterns:

let

root' = "${toString root}/";

matchers = map mkMatcher patterns;

in

name: type:

let

name' = removePrefix root' name;

in

any (m: m name' type) matchers;

in

src: patterns:

lib.cleanSourceWith {

filter = mkSourceFilter src patterns;

inherit src;

};

in

{

inherit

pathIsGitRepo

commitIdFromGitRepo

cleanSource

cleanSourceWith

cleanSourceFilter

pathHasContext

canCleanSource

urlToName

shortRev

revOrTag

repoRevToName

sourceByRegex

sourceFilesBySuffices

sourceByGlobs

trace

;

inherit (builtins) filterSource;

}