about summary refs log tree commit diff
path: root/lib/customisation.nix
blob: 08fc5db0614de1ed49adadc574e68a9dbdb303f5 (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
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
{ lib }:

rec {


  /* `overrideDerivation drv f` takes a derivation (i.e., the result
     of a call to the builtin function `derivation`) and returns a new
     derivation in which the attributes of the original are overridden
     according to the function `f`.  The function `f` is called with
     the original derivation attributes.

     `overrideDerivation` allows certain "ad-hoc" customisation
     scenarios (e.g. in ~/.config/nixpkgs/config.nix).  For instance,
     if you want to "patch" the derivation returned by a package
     function in Nixpkgs to build another version than what the
     function itself provides.

     For another application, see build-support/vm, where this
     function is used to build arbitrary derivations inside a QEMU
     virtual machine.

     Note that in order to preserve evaluation errors, the new derivation's
     outPath depends on the old one's, which means that this function cannot
     be used in circular situations when the old derivation also depends on the
     new one.

     You should in general prefer `drv.overrideAttrs` over this function;
     see the nixpkgs manual for more information on overriding.

     Example:
       mySed = overrideDerivation pkgs.gnused (oldAttrs: {
         name = "sed-4.2.2-pre";
         src = fetchurl {
           url = ftp://alpha.gnu.org/gnu/sed/sed-4.2.2-pre.tar.bz2;
           hash = "sha256-MxBJRcM2rYzQYwJ5XKxhXTQByvSg5jZc5cSHEZoB2IY=";
         };
         patches = [];
       });

     Type:
       overrideDerivation :: Derivation -> ( Derivation -> AttrSet ) -> Derivation
  */
  overrideDerivation = drv: f:
    let
      newDrv = derivation (drv.drvAttrs // (f drv));
    in lib.flip (extendDerivation (builtins.seq drv.drvPath true)) newDrv (
      { meta = drv.meta or {};
        passthru = if drv ? passthru then drv.passthru else {};
      }
      //
      (drv.passthru or {})
      //
      lib.optionalAttrs (drv ? __spliced) {
        __spliced = {} // (lib.mapAttrs (_: sDrv: overrideDerivation sDrv f) drv.__spliced);
      });


  /* `makeOverridable` takes a function from attribute set to attribute set and
     injects `override` attribute which can be used to override arguments of
     the function.

     Please refer to  documentation on [`<pkg>.overrideDerivation`](#sec-pkg-overrideDerivation) to learn about `overrideDerivation` and caveats
     related to its use.

     Example:
       nix-repl> x = {a, b}: { result = a + b; }

       nix-repl> y = lib.makeOverridable x { a = 1; b = 2; }

       nix-repl> y
       { override = «lambda»; overrideDerivation = «lambda»; result = 3; }

       nix-repl> y.override { a = 10; }
       { override = «lambda»; overrideDerivation = «lambda»; result = 12; }

     Type:
       makeOverridable :: (AttrSet -> a) -> AttrSet -> a
  */
  makeOverridable = f:
    let
      # Creates a functor with the same arguments as f
      mirrorArgs = lib.mirrorFunctionArgs f;
    in
    mirrorArgs (origArgs:
    let
      result = f origArgs;

      # Changes the original arguments with (potentially a function that returns) a set of new attributes
      overrideWith = newArgs: origArgs // (if lib.isFunction newArgs then newArgs origArgs else newArgs);

      # Re-call the function but with different arguments
      overrideArgs = mirrorArgs (newArgs: makeOverridable f (overrideWith newArgs));
      # Change the result of the function call by applying g to it
      overrideResult = g: makeOverridable (mirrorArgs (args: g (f args))) origArgs;
    in
      if builtins.isAttrs result then
        result // {
          override = overrideArgs;
          overrideDerivation = fdrv: overrideResult (x: overrideDerivation x fdrv);
          ${if result ? overrideAttrs then "overrideAttrs" else null} = fdrv:
            overrideResult (x: x.overrideAttrs fdrv);
        }
      else if lib.isFunction result then
        # Transform the result into a functor while propagating its arguments
        lib.setFunctionArgs result (lib.functionArgs result) // {
          override = overrideArgs;
        }
      else result);


  /* Call the package function in the file `fn` with the required
    arguments automatically.  The function is called with the
    arguments `args`, but any missing arguments are obtained from
    `autoArgs`.  This function is intended to be partially
    parameterised, e.g.,

      ```nix
      callPackage = callPackageWith pkgs;
      pkgs = {
        libfoo = callPackage ./foo.nix { };
        libbar = callPackage ./bar.nix { };
      };
      ```

    If the `libbar` function expects an argument named `libfoo`, it is
    automatically passed as an argument.  Overrides or missing
    arguments can be supplied in `args`, e.g.

      ```nix
      libbar = callPackage ./bar.nix {
        libfoo = null;
        enableX11 = true;
      };
      ```

    <!-- TODO: Apply "Example:" tag to the examples above -->

    Type:
      callPackageWith :: AttrSet -> ((AttrSet -> a) | Path) -> AttrSet -> a
  */
  callPackageWith = autoArgs: fn: args:
    let
      f = if lib.isFunction fn then fn else import fn;
      fargs = lib.functionArgs f;

      # All arguments that will be passed to the function
      # This includes automatic ones and ones passed explicitly
      allArgs = builtins.intersectAttrs fargs autoArgs // args;

      # a list of argument names that the function requires, but
      # wouldn't be passed to it
      missingArgs = lib.attrNames
        # Filter out arguments that have a default value
        (lib.filterAttrs (name: value: ! value)
        # Filter out arguments that would be passed
        (removeAttrs fargs (lib.attrNames allArgs)));

      # Get a list of suggested argument names for a given missing one
      getSuggestions = arg: lib.pipe (autoArgs // args) [
        lib.attrNames
        # Only use ones that are at most 2 edits away. While mork would work,
        # levenshteinAtMost is only fast for 2 or less.
        (lib.filter (lib.strings.levenshteinAtMost 2 arg))
        # Put strings with shorter distance first
        (lib.sort (x: y: lib.strings.levenshtein x arg < lib.strings.levenshtein y arg))
        # Only take the first couple results
        (lib.take 3)
        # Quote all entries
        (map (x: "\"" + x + "\""))
      ];

      prettySuggestions = suggestions:
        if suggestions == [] then ""
        else if lib.length suggestions == 1 then ", did you mean ${lib.elemAt suggestions 0}?"
        else ", did you mean ${lib.concatStringsSep ", " (lib.init suggestions)} or ${lib.last suggestions}?";

      errorForArg = arg:
        let
          loc = builtins.unsafeGetAttrPos arg fargs;
          # loc' can be removed once lib/minver.nix is >2.3.4, since that includes
          # https://github.com/NixOS/nix/pull/3468 which makes loc be non-null
          loc' = if loc != null then loc.file + ":" + toString loc.line
            else if ! lib.isFunction fn then
              toString fn + lib.optionalString (lib.sources.pathIsDirectory fn) "/default.nix"
            else "<unknown location>";
        in "Function called without required argument \"${arg}\" at "
        + "${loc'}${prettySuggestions (getSuggestions arg)}";

      # Only show the error for the first missing argument
      error = errorForArg (lib.head missingArgs);

    in if missingArgs == [] then makeOverridable f allArgs else abort error;


  /* Like callPackage, but for a function that returns an attribute
     set of derivations. The override function is added to the
     individual attributes.

     Type:
       callPackagesWith :: AttrSet -> ((AttrSet -> AttrSet) | Path) -> AttrSet -> AttrSet
  */
  callPackagesWith = autoArgs: fn: args:
    let
      f = if lib.isFunction fn then fn else import fn;
      auto = builtins.intersectAttrs (lib.functionArgs f) autoArgs;
      origArgs = auto // args;
      pkgs = f origArgs;
      mkAttrOverridable = name: _: makeOverridable (newArgs: (f newArgs).${name}) origArgs;
    in
      if lib.isDerivation pkgs then throw
        ("function `callPackages` was called on a *single* derivation "
          + ''"${pkgs.name or "<unknown-name>"}";''
          + " did you mean to use `callPackage` instead?")
      else lib.mapAttrs mkAttrOverridable pkgs;


  /* Add attributes to each output of a derivation without changing
     the derivation itself and check a given condition when evaluating.

     Type:
       extendDerivation :: Bool -> Any -> Derivation -> Derivation
  */
  extendDerivation = condition: passthru: drv:
    let
      outputs = drv.outputs or [ "out" ];

      commonAttrs = drv // (builtins.listToAttrs outputsList) //
        ({ all = map (x: x.value) outputsList; }) // passthru;

      outputToAttrListElement = outputName:
        { name = outputName;
          value = commonAttrs // {
            inherit (drv.${outputName}) type outputName;
            outputSpecified = true;
            drvPath = assert condition; drv.${outputName}.drvPath;
            outPath = assert condition; drv.${outputName}.outPath;
          } //
            # TODO: give the derivation control over the outputs.
            #       `overrideAttrs` may not be the only attribute that needs
            #       updating when switching outputs.
            lib.optionalAttrs (passthru?overrideAttrs) {
              # TODO: also add overrideAttrs when overrideAttrs is not custom, e.g. when not splicing.
              overrideAttrs = f: (passthru.overrideAttrs f).${outputName};
            };
        };

      outputsList = map outputToAttrListElement outputs;
    in commonAttrs // {
      drvPath = assert condition; drv.drvPath;
      outPath = assert condition; drv.outPath;
    };

  /* Strip a derivation of all non-essential attributes, returning
     only those needed by hydra-eval-jobs. Also strictly evaluate the
     result to ensure that there are no thunks kept alive to prevent
     garbage collection.

     Type:
       hydraJob :: (Derivation | Null) -> (Derivation | Null)
  */
  hydraJob = drv:
    let
      outputs = drv.outputs or ["out"];

      commonAttrs =
        { inherit (drv) name system meta; inherit outputs; }
        // lib.optionalAttrs (drv._hydraAggregate or false) {
          _hydraAggregate = true;
          constituents = map hydraJob (lib.flatten drv.constituents);
        }
        // (lib.listToAttrs outputsList);

      makeOutput = outputName:
        let output = drv.${outputName}; in
        { name = outputName;
          value = commonAttrs // {
            outPath = output.outPath;
            drvPath = output.drvPath;
            type = "derivation";
            inherit outputName;
          };
        };

      outputsList = map makeOutput outputs;

      drv' = (lib.head outputsList).value;
    in if drv == null then null else
      lib.deepSeq drv' drv';

  /* Make a set of packages with a common scope. All packages called
     with the provided `callPackage` will be evaluated with the same
     arguments. Any package in the set may depend on any other. The
     `overrideScope'` function allows subsequent modification of the package
     set in a consistent way, i.e. all packages in the set will be
     called with the overridden packages. The package sets may be
     hierarchical: the packages in the set are called with the scope
     provided by `newScope` and the set provides a `newScope` attribute
     which can form the parent scope for later package sets.

     Type:
       makeScope :: (AttrSet -> ((AttrSet -> a) | Path) -> AttrSet -> a) -> (AttrSet -> AttrSet) -> AttrSet
  */
  makeScope = newScope: f:
    let self = f self // {
          newScope = scope: newScope (self // scope);
          callPackage = self.newScope {};
          overrideScope = g: makeScope newScope (lib.fixedPoints.extends g f);
          # Remove after 24.11 is released.
          overrideScope' = g: lib.warnIf (lib.isInOldestRelease 2311)
            "`overrideScope'` (from `lib.makeScope`) has been renamed to `overrideScope`."
            (makeScope newScope (lib.fixedPoints.extends g f));
          packages = f;
        };
    in self;

  /* backward compatibility with old uncurried form; deprecated */
  makeScopeWithSplicing =
    splicePackages: newScope: otherSplices: keep: extra: f:
    makeScopeWithSplicing'
    { inherit splicePackages newScope; }
    { inherit otherSplices keep extra f; };

  /* Like makeScope, but aims to support cross compilation. It's still ugly, but
     hopefully it helps a little bit.

     Type:
       makeScopeWithSplicing' ::
         { splicePackages :: Splice -> AttrSet
         , newScope :: AttrSet -> ((AttrSet -> a) | Path) -> AttrSet -> a
         }
         -> { otherSplices :: Splice, keep :: AttrSet -> AttrSet, extra :: AttrSet -> AttrSet }
         -> AttrSet

       Splice ::
         { pkgsBuildBuild :: AttrSet
         , pkgsBuildHost :: AttrSet
         , pkgsBuildTarget :: AttrSet
         , pkgsHostHost :: AttrSet
         , pkgsHostTarget :: AttrSet
         , pkgsTargetTarget :: AttrSet
         }
  */
  makeScopeWithSplicing' =
    { splicePackages
    , newScope
    }:
    { otherSplices
    # Attrs from `self` which won't be spliced.
    # Avoid using keep, it's only used for a python hook workaround, added in PR #104201.
    # ex: `keep = (self: { inherit (self) aAttr; })`
    , keep ? (_self: {})
    # Additional attrs to add to the sets `callPackage`.
    # When the package is from a subset (but not a subset within a package IS #211340)
    # within `spliced0` it will be spliced.
    # When using an package outside the set but it's available from `pkgs`, use the package from `pkgs.__splicedPackages`.
    # If the package is not available within the set or in `pkgs`, such as a package in a let binding, it will not be spliced
    # ex:
    # ```
    # nix-repl> darwin.apple_sdk.frameworks.CoreFoundation
    #   «derivation ...CoreFoundation-11.0.0.drv»
    # nix-repl> darwin.CoreFoundation
    #   error: attribute 'CoreFoundation' missing
    # nix-repl> darwin.callPackage ({ CoreFoundation }: CoreFoundation) { }
    #   «derivation ...CoreFoundation-11.0.0.drv»
    # ```
    , extra ? (_spliced0: {})
    , f
    }:
    let
      spliced0 = splicePackages {
        pkgsBuildBuild = otherSplices.selfBuildBuild;
        pkgsBuildHost = otherSplices.selfBuildHost;
        pkgsBuildTarget = otherSplices.selfBuildTarget;
        pkgsHostHost = otherSplices.selfHostHost;
        pkgsHostTarget = self; # Not `otherSplices.selfHostTarget`;
        pkgsTargetTarget = otherSplices.selfTargetTarget;
      };
      spliced = extra spliced0 // spliced0 // keep self;
      self = f self // {
        newScope = scope: newScope (spliced // scope);
        callPackage = newScope spliced; # == self.newScope {};
        # N.B. the other stages of the package set spliced in are *not*
        # overridden.
        overrideScope = g: (makeScopeWithSplicing'
          { inherit splicePackages newScope; }
          { inherit otherSplices keep extra;
            f = lib.fixedPoints.extends g f;
          });
        packages = f;
      };
    in self;

}