about summary refs log tree commit diff
path: root/lib/sources.nix
blob: f61ea306aec562d5bb76fd75575d8088fc494cc9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
/* Functions for copying sources to the Nix store. */
{ lib }:

# Tested in lib/tests/sources.sh
let
  inherit (builtins)
    match
    split
    storeDir
    ;
  inherit (lib)
    boolToString
    filter
    isString
    readFile
    ;
  inherit (lib.filesystem)
    pathIsRegularFile
    ;

  /*
    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 {

  pathType = lib.warnIf (lib.isInOldestRelease 2305)
    "lib.sources.pathType has been moved to lib.filesystem.pathType."
    lib.filesystem.pathType;

  pathIsDirectory = lib.warnIf (lib.isInOldestRelease 2305)
    "lib.sources.pathIsDirectory has been moved to lib.filesystem.pathIsDirectory."
    lib.filesystem.pathIsDirectory;

  pathIsRegularFile = lib.warnIf (lib.isInOldestRelease 2305)
    "lib.sources.pathIsRegularFile has been moved to lib.filesystem.pathIsRegularFile."
    lib.filesystem.pathIsRegularFile;

  inherit
    pathIsGitRepo
    commitIdFromGitRepo

    cleanSource
    cleanSourceWith
    cleanSourceFilter
    pathHasContext
    canCleanSource

    sourceByRegex
    sourceFilesBySuffices

    trace
    ;
}