Commit graph

31 commits

Author SHA1 Message Date
Eelco Dolstra
5cd72598fe Add support for impure derivations
Impure derivations are derivations that can produce a different result
every time they're built. Example:

  stdenv.mkDerivation {
    name = "impure";
    __impure = true; # marks this derivation as impure
    outputHashAlgo = "sha256";
    outputHashMode = "recursive";
    buildCommand = "date > $out";
  };

Some important characteristics:

* This requires the 'impure-derivations' experimental feature.

* Impure derivations are not "cached". Thus, running "nix-build" on
  the example above multiple times will cause a rebuild every time.

* They are implemented similar to CA derivations, i.e. the output is
  moved to a content-addressed path in the store. The difference is
  that we don't register a realisation in the Nix database.

* Pure derivations are not allowed to depend on impure derivations. In
  the future fixed-output derivations will be allowed to depend on
  impure derivations, thus forming an "impurity barrier" in the
  dependency graph.

* When sandboxing is enabled, impure derivations can access the
  network in the same way as fixed-output derivations. In relaxed
  sandboxing mode, they can access the local filesystem.
2022-03-31 13:43:20 +02:00
John Ericson
197feed51d Clean up DerivationOutput, and headers
1. `DerivationOutput` now as the `std::variant` as a base class. And the
   variants are given hierarchical names under `DerivationOutput`.

   In 8e0d0689be @matthewbauer and I
   didn't know a better idiom, and so we made it a field. But this sort
   of "newtype" is anoying for literals downstream.

   Since then we leaned the base class, inherit the constructors trick,
   e.g. used in `DerivedPath`. Switching to use that makes this more
   ergonomic, and consistent.

2. `store-api.hh` and `derivations.hh` are now independent.

   In bcde5456cc I swapped the dependency,
   but I now know it is better to just keep on using incomplete types as
   much as possible for faster compilation and good separation of
   concerns.
2022-03-17 22:35:53 +00:00
Eelco Dolstra
54888b92de Move installables-related operations 2022-03-02 19:19:51 +01:00
John Ericson
242f9bf3dc std::visit by reference
I had started the trend of doing `std::visit` by value (because a type
error once mislead me into thinking that was the only form that
existed). While the optomizer in principle should be able to deal with
extra coppying or extra indirection once the lambdas inlined, sticking
with by reference is the conventional default. I hope this might even
improve performance.
2021-09-30 21:35:09 +00:00
Eelco Dolstra
3da9a9241c Convert option descriptions to Markdown 2021-01-13 14:18:04 +01:00
Eelco Dolstra
4f3e7f4eec
Add 'nix show-derivation' manpage 2020-12-21 13:32:29 +01:00
Eelco Dolstra
3b123a6ee6
nix show-derivation: Say "system" instead of "platform"
There is really no good reason to use "platform" except that that's
what we use internally (also for no good reason).
2020-12-21 13:32:29 +01:00
Eelco Dolstra
0c15ae5d4b Add FIXME 2020-12-03 20:31:45 +01:00
regnat
c092fa4702 Allow non-CA derivations to depend on CA derivations 2020-10-27 07:29:23 +01:00
Eelco Dolstra
85c8be6286 Remove static variable name clashes
This was useful for an experiment with building Nix as a single
compilation unit. It's not very useful otherwise but also doesn't
hurt...
2020-10-06 13:49:20 +02:00
John Ericson
f899a7c6d7 Work around clang bug 2020-08-14 18:51:31 +00:00
John Ericson
3c8b5b6219 Merge remote-tracking branch 'upstream/master' into single-ca-drv-build 2020-08-14 17:00:13 +00:00
John Ericson
e913a2989f Squashed get CA derivations building 2020-08-07 19:51:55 +00:00
Carlo Nucera
1d2e80ddd6 Merge branch 'master' of github.com:NixOS/nix into new-interface-for-path-pathOpt 2020-08-05 15:45:33 -04:00
John Ericson
b9ebe373bb Sed some names to perhaps avoid conflicts 2020-08-05 14:49:25 +00:00
Carlo Nucera
7ef1e3cd14 Use the new interface 2020-07-28 13:59:24 -04:00
Carlo Nucera
745a03cef5 Merge branch 'optional-derivation-output-storepath' of github.com:obsidiansystems/nix into ca-derivation-data-types 2020-07-16 13:36:01 -04:00
Carlo Nucera
048e916f64 Merge branch 'master' of github.com:NixOS/nix into optional-derivation-output-storepath 2020-07-16 13:32:28 -04:00
Eelco Dolstra
2d6d53bc87 nix: Fix examples 2020-07-15 20:28:16 +02:00
John Ericson
230c9b4329 Change types to prepare the way for CA derivations
We've added the variant to `DerivationOutput` to support them, but made
`DerivationOutput::path` partial to avoid actually implementing them.

With this chage, we can all collaborate on "just" removing
`DerivationOutput::path` calls to implement CA derivations.
2020-07-12 23:53:33 +00:00
John Ericson
fedfc913ad Use more std::visit to prepare for new variant
N.B. not using `std::visit` for fetchurl because there is no attempt to
handle all the cases (e.g. no `else`) and lambda complicates early
return.
2020-07-12 23:51:40 +00:00
Matthew Bauer
8e0d0689be Only store hash of fixed derivation output
we don’t need a full storepath for a fixedoutput derivation. So just
putting the ingestion method + the hash is sufficient.
2020-07-08 19:11:39 -04:00
John Ericson
517f5980e2 Merge remote-tracking branch 'upstream/master' into no-stringly-typed-derivation-output 2020-06-17 04:58:43 +00:00
Eelco Dolstra
9f736dd89d Add Store::readDerivation() convenience function 2020-06-12 13:04:52 +02:00
Carlo Nucera
d49e65ba9d Merge remote-tracking branch 'john-ericson/enum-FileIngestionMethod' into no-stringly-typed-derivation-output 2020-05-26 12:30:48 -04:00
Eelco Dolstra
f132d82a79 nix --help: Group commands 2020-05-05 15:18:23 +02:00
Eelco Dolstra
a721a0b114 Flag: Use designated initializers 2020-05-04 22:40:19 +02:00
John Ericson
832bd534dc Store parsed hashes in DerivationOutput
It's best to detect invalid data as soon as possible, with data types
that make storing it impossible.
2020-03-30 11:33:35 -04:00
Eelco Dolstra
bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00
Eelco Dolstra
ac67685606 Make subcommand construction in MultiCommand lazy
(cherry picked from commit a0de58f471)
2019-12-05 20:19:26 +01:00
Eelco Dolstra
e8d6ee7c1b
Add "nix show-derivation"
This debug command prints a store derivation in JSON format. For
example:

  $ nix show-derivation nixpkgs.hello
  {
    "/nix/store/ayjwpwwiyy04nh9z71rsdgd3q7bra7ch-hello-2.10.drv": {
      "outputs": {
        "out": {
          "path": "/nix/store/w5w4v29ql0qwqhczkdxs94ix2lh7ibgs-hello-2.10"
        }
      },
      "inputSrcs": [
        "/nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25b-default-builder.sh"
      ],
      "inputDrvs": {
        "/nix/store/13839aqdf6x4k3b785rw5f2l7857l6y3-bash-4.4-p12.drv": [
          "out"
        ],
        "/nix/store/vgdx7fdc7d4iirmnwj2py1nrvr5qwzj7-hello-2.10.tar.gz.drv": [
          "out"
        ],
        "/nix/store/x3kkd0vsqfflbvwf1055l9mr39bg0ms0-stdenv.drv": [
          "out"
        ]
      },
      "platform": "x86_64-linux",
      "builder": "/nix/store/qp5fw57d38bd1n07ss4zxh88zg67c3vg-bash-4.4-p12/bin/bash",
      "args": [
        "-e",
        "/nix/store/9krlzvny65gdc8s7kpb6lkx8cd02c25b-default-builder.sh"
      ],
      "env": {
        "buildInputs": "",
        "builder": "/nix/store/qp5fw57d38bd1n07ss4zxh88zg67c3vg-bash-4.4-p12/bin/bash",
        "configureFlags": "",
        "doCheck": "1",
        "name": "hello-2.10",
        "nativeBuildInputs": "",
        "out": "/nix/store/w5w4v29ql0qwqhczkdxs94ix2lh7ibgs-hello-2.10",
        "propagatedBuildInputs": "",
        "propagatedNativeBuildInputs": "",
        "src": "/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz",
        "stdenv": "/nix/store/6zngq1rdh0ans9qyckqimqibgnlvlfrm-stdenv",
        "system": "x86_64-linux"
      }
    }
  }

This removes the need for pp-aterm.
2017-09-25 13:43:35 +02:00