Commit graph

160 commits

Author SHA1 Message Date
Adam Joseph
012b44244b feat(tvix/eval): builtins.hasContext: placeholder implementation
Currently this just `throw`s a message explaining that it is not
implemented.  This is necessary in order to allow enumerating the
nixpkgs release attrset (afaict only one package uses this builtin).

Change-Id: I45266d46af579ddb5856b192b6be4b481369543c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10302
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-12-12 17:21:53 +00:00
Adam Joseph
531f0c0c42 fix(tvix/eval): baseNameOf should not coerce paths into strings
... since this may import them to the store which changes their
basename.

Fixes b/350.

Change-Id: Iabd08ff4d6a424c66d6d7784d7a96b0c078f0a91
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10298
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 17:21:21 +00:00
Adam Joseph
8d4aa2c15c fix(tvix/eval): add unimplemented __curPos and builtins.filterSource
This commit adds __curPos (to the global scope, yuck) and
builtins.filterSource.  These are not implemented; forcing them will
produce the same result as `throw "message"`.

Unfortunately these two post-2.3 features are used throughout
nixpkgs.  Since an unresolved indentifier is a catchable error, this
breaks the entire release eval.  With this commit, it simply causes
those broken packages that use these features to appear as they are:
broken.

Change-Id: Ib43dea571f6a9fab4d54869349f80ee4ec5424c2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10297
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 17:20:50 +00:00
Adam Joseph
1ac57b0d1c feat(tvix/eval): nonrecursive coerce_to_string()
After this commit, the only non-builtins uses of generators are:

  - coerce_to_string() uses generators::request_enter_lambda()
  - Thunk::force() uses generators::request_enter_lambda()

That's it!  Once those two are taken care of, GenCo can become an
implementation detail of `builtins::BuiltinGen`.  No more crazy
nonlocal flow control within the interpreter: if you've got a GenCo
floating around in your code it's because you're writing a builtin,
which isn't part of the core interpreter.  The interpreter won't
need GenCos to talk to itself anymore.

Technically generators::request_path_import() is also used by
coerce_to_string(), but that's just because the io_handle happens to
be part of the VM.  There's no recursion-depth issue there, so the
call doesn't need to go through the generator mechanism
(request_path_import() doesn't call back to the interpreter!)

Change-Id: I83ce5774d49b88fdafdd61160975b4937a435bb0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10256
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 14:54:46 +00:00
Adam Joseph
3701379745 feat(tvix/eval): nonrecursive deep_force()
This commit implements deep_force() nonrecursively, by maintaining
an explicit stack rather than using the call stack for recursion.

As an added bonus, we don't need to pass around the SharedThunkSet
anymore, and can in fact completely eliminate SharedThunkSet.

Change-Id: I7c4f59f37834d451a28bf6be317eb0a90eac4ee6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10252
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 14:36:02 +00:00
Adam Joseph
ad566999ca fix(tvix/eval): preserve catchables in nix_cmp_ordering(), fix b/338
This commit fixes b/338 by properly propagating catchables through
comparison operations.

Change-Id: I6b0283a40f228ecf9a6398d24c060bdacb1077cf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10221
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 14:26:46 +00:00
Adam Joseph
edbd5055a1 feat(tvix/eval): nonrecursive nix_cmp_ordering(), fixes b/339
This commit rewrites Value::nix_cmp_ordering() into an equivalent
nonrecursive form.  Except for calls to Thunk::force(), the new form
no longer uses generators, and is async only because of the fact
that it calls Thunk::force().

I originally believed that this commit would make evaluation faster.
In fact it is slightly slower.  I believe this is due to the added
vec![] allocation.  I am investigating.

Prev-Nixpkgs-Benchmark: {"attrpath":"pkgsCross.aarch64-multiplatform.hello.outPath","peak-kbytes":"460048","system-seconds":"0.68","user-seconds":"5.73"}
This-Nixpkgs-Benchmark: {"attrpath":"pkgsCross.aarch64-multiplatform.hello.outPath","peak-kbytes":"460224","system-seconds":"0.67","user-seconds":"5.84"}
Change-Id: Ic627bc220d9c5aa3c5e68b9b8bf199837cd55af5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10212
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 14:26:46 +00:00
Adam Joseph
8a40f75c2d fix(tvix/eval): never use partial_cmp() (partial fix b/338)
This is part of a fix for b/338.

We should never use PartialOrd::partial_cmp().

All Nix types except floats are obviously totally-ordered.  In
addition, it turns out that because Nix treats division by zero
rather than producing a NaN, and because it does not support
"negative zero", even floats are in fact totally ordered in Nix.

Therefore, every call to PartialOrd::partial_cmp() in tvix is an
error.  We have to *implement* this function, but we should never
call it on built-in types.

Moreover, nix_cmp_ordering() currently returns an Option<Ordering>.
I'm not sure what was going on there, since it's impossible for it
to return None.  This commit fixes it to return simply Ordering
rather than Option<Ordering>.

Change-Id: If5c084164cf19cfb38c5a15554c0422faa5f895d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10218
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-12-12 14:26:46 +00:00
Aspen Smith
8135a8d38c fix(tvix/eval): Return error rather than panicking on bad substring
If builtins.substring is invoked with (byte!!) offsets that aren't at
codepoint boundaries, return an error rather than panicking. This is
still incorrect (see b/337) but pushes the incorrectness forward a step.

Change-Id: I5a4261f2ff250874cd36489ef598dcf886669d04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10199
Tested-by: BuildkiteCI
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-12-05 23:12:23 +00:00
Vincent Ambo
e65fa82d74 refactor(tvix/eval): use or_default helper in entry API
This fixes a future clippy lint.

Change-Id: Ic830e94ef23595580c1037f10878c76bbb546dd9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10110
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
2023-11-25 15:48:46 +00:00
Vincent Ambo
b3b1f649d6 chore(tvix): fix trivial clippy lints
Relates to b/321.

Change-Id: I37284f89b186e469eb432e2bbedb37aa125a6ad4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9961
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
2023-11-05 20:28:37 +00:00
Vincent Ambo
d91fcd4f28 refactor(tvix/eval): more efficiently intersect attributes
builtins.intersectAttrs is used a _lot_ in nixpkgs eval, for whatever
reason. We previously had a very inefficient implementation that would
allocate for each comparison. It stuck out like a sore thumb in perf
analysis.

This moves to a custom algorithm with two iterators, one for the left
and one for the right side, advancing them along the (borrowed) map
keys until a match is found and allocation is required.

I've not made any effort to reduce the verbosity of this code, I don't
think it's worth it.

On my machine this reduces the mean runtime of evaluating
`nixpkgs.emacs.outPath` by ~8%.

Change-Id: Ie506d82cb8d5f45909628f771a6b73e0eca16b27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9898
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-11-03 09:24:30 +00:00
Adam Joseph
05f42519b5 fix(tvix/eval): fix b/281 by adding Value::Catchable
This commit makes catchable errors a variant of Value.

The main downside of this approach is that we lose the ability to
use Rust's `?` syntax for propagating catchable errors.

Change-Id: Ibe89438d8a70dcec29e016df692b5bf88a5cad13
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9289
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-09-24 21:54:10 +00:00
Adam Joseph
926459ce69 refactor(tvix/eval): factor CatchableErrorKind out of ErrorKind
This commit creates a separate enum for "catchable" errors (the kind
that `builtins.tryEval` can detect).

Change-Id: Ie81d1112526d852255d9842f67045f88eab192af
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9287
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-09-24 21:54:09 +00:00
Linus Heckemann
a3dbb60213 fix(tvix/eval): off-by-one in replaceStrings
replaceStrings would previously fail to replace the last character
in a string.

Change-Id: I43a7c960945350b2e7a5b731b7fdb617723eb38f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9151
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-08-24 10:07:48 +00:00
Florian Klink
def773d4d5 refactor(tvix/eval): cargo clippy (len() is usize)
Change-Id: I9d931ffcc03c6df7c0392dbc1c9a4ae0e3804213
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9099
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-08-20 21:51:04 +00:00
Evgeny Zemtsov
c8fcdca4eb feat(tvix/eval): allow extending builtins outside of tvix_eval
The change allows applications that use tvix_serde for parsing
nix-based configuration to extend the language with domain-specific
set of features.

Change-Id: Ia86612308a167c456ecf03e93fe0fbae55b876a6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8848
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-22 20:19:06 +00:00
Linus Heckemann
5733274876 fix(tvix/eval): allow negative substring lengths
Nix uses string::substr without checking the sign of the length[1].
The NixOS testing infrastructure relies on this[2], and on the
implicit conversion of that to the maximum possible value for a
size_t.

[1]: ecae62020b/src/libexpr/primops.cc (L3597)
[2]: c7c2984716/nixos/lib/testing/driver.nix (L29)

Change-Id: I6d0caf6830b6bda3fdf44c40c81de6a1befeca7b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8746
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-06-12 08:38:49 +00:00
sterni
3b33c19a9c fix(tvix): don't call function eagerly in genList, map & mapAttrs
mapAttrs, map and genList call Nix functions provided by the caller and
store the result of applying them in a Nix data structure that does not
force all of its contents when forced itself. This means that when such
a builtin application is forced, the Nix function calls performed by the
builtin should not be forced: They may be forced later, but it is also
possible that they will never be forced, e.g. in

    builtins.length (builtins.map (builtins.add 2) [ 1 2 3 ])

it is not necessary to compute a single application of builtins.add.

Since request_call_with immediately performs the function call
requested, Tvix would compute function applications unnecessarily before
this change. Because this was not followed by a request_force, the
impact of this was relatively low in Nix code (most functions return a
new thunk after being applied), but it was enough to cause a lot of
bogus builtins.trace applications when evaluating anything from
`lib.modules`. The newly added test includes many cases where Tvix
previously incorrectly applied a builtin, breaking a working expression.

To fix this we add a new helper to construct a Thunk performing a
function application at runtime from a function and argument given as
`Value`s. This mimics the compiler's compile_apply(), but does itself
not require a compiler, since the necessary Lambda can be constructed
independently.

I also looked into other builtins that call a Nix function to verify
that they don't exhibit such a problem:

- Many builtins immediately use the resulting value in a way that makes
  it necessary to compute all the function calls they do as soon as
  the outer builtin application is forced:

  * all
  * any
  * filter
  * groupBy
  * partition

- concatMap needs to (shallowly) force the returned list for
  concatenation.

- foldl' is strict in the application of `op` (I added a comment that
  makes this explicit).

- genericClosure needs to (shallowly) force the resulting list and some
  keys of the attribute sets inside.

Resolves b/272.

Change-Id: I1fa53f744bcffc035da84c1f97ed25d146830446
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8651
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-26 22:35:39 +00:00
Vincent Ambo
969fbcd6d4 fix(tvix/eval): builtins.trace prints to stderr
Change-Id: Icf577396035474d6977e627058aba5805c61985e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8563
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
2023-05-12 12:50:59 +00:00
Vincent Ambo
b78ae941a4 fix(tvix/eval): use coerce_to_string in builtins.substring
This actually uses coercion under the hood in C++ Nix. See the test
for an example.

Change-Id: Id56b364acf269225b6829d0b600e0222f8b3608d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8322
Reviewed-by: andi <andi@notmuch.email>
Tested-by: BuildkiteCI
2023-03-17 19:17:29 +00:00
Vincent Ambo
b5f5a1595d chore(tvix/eval): remove some dead code
This was commented out and forgotten during the generator refactor, oh
well.

Change-Id: I474b685159a955a846db462da0dd0067af177b04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8321
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-03-17 11:01:07 +00:00
Vincent Ambo
5d9bfd7735 fix(tvix/eval): emit warnings from builtins.import again
Wires up generator logic to emit warnings that already have spans
attached again.

Change-Id: I9f878cec3b9d4f6f7819e7c71bab7ae70bd3f08b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8224
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
939cebd0f1 fix(tvix/eval): implement cppnix JSON-serialisation semantics
This drops the usage of serde::Serialize, as the trait can not be used
to implement the correct semantics (function colouring!).

Instead, a manual JSON serialisation function is written which
correctly handles toString, outPath and other similar weirdnesses.

Unexpectedly, the eval-okay-tojson test from the C++ Nix test suite
now passes, too.

This fixes an issue where serialising data structures containing
derivations to JSON would fail.

Change-Id: I5c39e3d8356ee93a07eda481410f88610f6dd9f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8209
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
dfd0066de5 fix(tvix/eval): handle toJSON on attribute sets with outPath
These are serialised as the serialisation of the value of that field.

Change-Id: Ida51708b1f43ce09b0ec835f4e265918aa31dd09
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8205
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
7d339d2762 fix(tvix/eval): handle __toString when JSON-serialising attrsets
These must be serialised to a JSON string of the *result* of coercing
the function application to a string.

Change-Id: Ib7f49ccd950503ddbdbf99643cd59565e26b50da
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8204
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
43d04d9b98 refactor(tvix/eval): box PathBuf
This shaves another 8 bytes off Value. How did that type get so big?!

Change-Id: I65e9b59a1636bd57e3cc4aec5fea16887070b832
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8153
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
4bbfeaf1cb refactor(tvix/eval): wrap NixList in Rc
The size of a `Vector<Value>` is 64 *bytes*, which is quite large, and
it bloated the entire Value type to this size.

This change adds an indirection for the inner vector through Rc.
Initially I tried to use a Box, but this breaks pointer equality
guarantees for the Vector when it is small enough to be inlined.

This reduces the size of Value from 64 to 32 bytes.

Change-Id: Ic3211e861b1966c78b2c3d536ba291fea92647fd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8150
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
025c67bf4d refactor(tvix/eval): flatten call stack of VM using generators
Warning: This is probably the biggest refactor in tvix-eval history,
so far.

This replaces all instances of trampolines and recursion during
evaluation of the VM loop with generators. A generator is an
asynchronous function that can be suspended to yield a message (in our
case, vm::generators::GeneratorRequest) and receive a
response (vm::generators::GeneratorResponsee).

The `genawaiter` crate provides an interpreter for generators that can
drive their execution and lets us move control flow between the VM and
suspended generators.

To do this, massive changes have occured basically everywhere in the
code. On a high-level:

1. The VM is now organised around a frame stack. A frame is either a
   call frame (execution of Tvix bytecode) or a generator frame (a
   running or suspended generator).

   The VM has an outer loop that pops a frame off the frame stack, and
   then enters an inner loop either driving the execution of the
   bytecode or the execution of a generator.

   Both types of frames have several branches that can result in the
   frame re-enqueuing itself, and enqueuing some other work (in the
   form of a different frame) on top of itself. The VM will eventually
   resume the frame when everything "above" it has been suspended.

   In this way, the VM's new frame stack takes over much of the work
   that was previously achieved by recursion.

2. All methods previously taking a VM have been refactored into async
   functions that instead emit/receive generator messages for
   communication with the VM.

   Notably, this includes *all* builtins.

This has had some other effects:

- Some test have been removed or commented out, either because they
  tested code that was mostly already dead (nix_eq) or because they
  now require generator scaffolding which we do not have in place for
  tests (yet).

- Because generator functions are technically async (though no async
  IO is involved), we lose the ability to use much of the Rust
  standard library e.g. in builtins. This has led to many algorithms
  being unrolled into iterative versions instead of iterator
  combinations, and things like sorting had to be implemented from scratch.

- Many call sites that previously saw a `Result<..., ErrorKind>`
  bubble up now only see the result value, as the error handling is
  encapsulated within the generator loop.

  This reduces number of places inside of builtin implementations
  where error context can be attached to calls that can fail.
  Currently what we gain in this tradeoff is significantly more
  detailed span information (which we still need to bubble up, this
  commit does not change the error display).

  We'll need to do some analysis later of how useful the errors turn
  out to be and potentially introduce some methods for attaching
  context to a generator frame again.

This change is very difficult to do in stages, as it is very much an
"all or nothing" change that affects huge parts of the codebase. I've
tried to isolate changes that can be isolated into the parent CLs of
this one, but this change is still quite difficult to wrap one's mind
and I'm available to discuss it and explain things to any reviewer.

Fixes: b/238, b/237, b/251 and potentially others.
Change-Id: I39244163ff5bbecd169fe7b274df19262b515699
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8104
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
503e6810e7 fix(tvix/eval): unsafeDiscardStringContext is a no-op
... not just a TODO.

Most use-cases of unsafeDiscardStringContext are for cases where a
string is processed in some ways and no longer contains a "physical"
reference, but still has its context attached in C++ Nix.

We don't need to do this. This does diverge in behaviour in use-cases
related to build scheduling, but that whole behaviour will be
different in Tvix.

Change-Id: I4056d4c09f62d44d6bd52b791db03fe5556672b5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8016
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-02-02 14:30:32 +00:00
Florian Klink
e0b05c0fa6 feat(tvix/eval): implement builtins.fromTOML
This allows parsing TOML from Tvix. We can enable the eval-okay-fromTOML
testcase from nix_tests. It uses the `toml` crate, and the serde
integration it brings with it.

Change-Id: Ic6f95aacf2aeb890116629b409752deac49dd655
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7920
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-25 07:49:44 +00:00
Vincent Ambo
f12f938166 refactor(tvix/eval): directly return builtin tuples from macro
All invocations of the builtin macro had to previously filter through
the `builtin_tuple` function, but it's more sensible to directly
return these from the macro.

Change-Id: I45600ba84d56c9528d3e92570461c319eea595ce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7825
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-20 15:39:51 +00:00
Vincent Ambo
d365b09226 feat(tvix/eval): implement builtins.toXML
Change-Id: I009efc53a8e98f0650ae660c4decd8216e8a06e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7835
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-16 13:43:14 +00:00
Aaqa Ishtyaq
158f4d1d69 fix(tvix/eval): len_without_is_empty clippy warn
This CL addresses clippy warning len_without_is_empty
which expects `.is_empty()` method to be present when
implementing `.len()` method for an item.

Change-Id: I8878db630b9ef5853649a906b764a33299bb5dc8
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7806
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-12 18:06:49 +00:00
Vincent Ambo
02d35e4aa6 feat(tvix/eval): implement builtins.toJSON
Implements `Serialize` for `tvix_eval::Value`. Special care is taken
with serialisation of attribute sets, and forcing of thunks.

The tests should cover both cases well.

Change-Id: I9bb135bacf6f87bc6bd0bd88cef0a42308e6c335
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7803
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-01-12 10:42:44 +00:00
Ryan Lahfa
805219a2fa feat(tvix/eval): implement serde::Deserialize for Value
Co-Authored-By: Vincent Ambo <tazjin@tvl.su>

Change-Id: Ib6f7d1f4f4faac36b44f5f75cccc57bf912cf606
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7626
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-10 09:53:21 +00:00
Vincent Ambo
1d59d3ba8f fix(tvix/eval): fix last uses of Vec<Value> -> NixList in builtins
Change-Id: I0d71b82eb7ddc1e457b0996b0668006f55f56751
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7790
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-01-08 11:11:52 +00:00
Vincent Ambo
e0c47f32af refactor(tvix/eval): use builtins macro for placeholders
Change-Id: I30bc475e3e36a163fa169083481cdd4b4d0ca456
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7785
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-01-06 20:53:02 +00:00
Vincent Ambo
6b6bd30772 refactor(tvix/eval): move mocked builtins.derivation to tests
This placeholder should not live in the main crate anymore as we will
be injecting the real one from outside of eval, but there are still
language tests that depend on a (simple, mockable) version of it.

Change-Id: I68ea169db15cbdbeed320930d3069e21e376c90d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7783
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-06 20:53:02 +00:00
sterni
5946b47ab7 feat(tvix/eval): add builtins.{null,true,false}
Code probably rarely relies on these, but it's not hard to support them.

Change-Id: I8499fec34efaf031f9c013bbd370a13db929a2a3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7772
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-01-06 12:14:42 +00:00
Vincent Ambo
3d238c350b refactor(tvix/eval): streamline construction of globals/builtins
Previously the construction of globals (a compiler-only concept) and
builtins (a (now) user-facing API) was intermingled between multiple
different modules, and kind of difficult to understand.

The complexity of this had grown in large part due to the
implementation of `builtins.import`, which required the notorious
"knot-tying" trick using Rc::new_cyclic (see cl/7097) for constructing
the set of globals.

As part of the new `Evaluation` API users should have the ability to
bring their own builtins, and control explicitly whether or not impure
builtins are available (regardless of whether they're compiled in or
not).

To streamline the construction and allow the new API features to work,
this commit restructures things by making these changes:

1. The `tvix_eval::builtins` module is now only responsible for
   exporting sets of builtins. It no longer has any knowledge of
   whether or not certain sets (e.g. only pure, or pure+impure) are
   enabled, and it has no control over which builtins are globally
   available (this is now handled in the compiler).

2. The compiler module is now responsible for both constructing the
   final attribute set of builtins from the set of builtins supplied
   by a user, as well as for populating its globals (that is
   identifiers which are available at the top-level scope).

3. The `Evaluation` API now carries a `builtins` field which is
   populated with the pure builtins by default, and can be extended by
   users.

4. The `import` feature has been moved into the compiler, as a
   special case. In general, builtins no longer have the ability to
   reference the "fix point" of the globals set.

This should not change any functionality, and in fact preserves minor
differences between Tvix/Nix that we already had (such as
`builtins.builtins` not existing).

Change-Id: Icdf5dd50eb81eb9260d89269d6e08b1e67811a2c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7738
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-04 12:28:43 +00:00
Vincent Ambo
86361f0f4a refactor(tvix/eval): remove extra Rc<..> around Value::Attrs
The `im::OrdMap` is already small and cheap to copy while sharing
memory, so this is not required anymore.

Only the `KV` variant may have slightly larger content, but in
practice this doesn't seem to make a difference when comparing the two
variants and this one is less complicated.

Change-Id: I64a563b209a2444125653777551373cb2989ca7d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7677
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-12-29 17:44:56 +00:00
Vincent Ambo
91465dc78e refactor(tvix/eval): persistent, memory-sharing OrdMap for NixAttrs
This uses the `im::OrdMap` for `NixAttrs` to enable sharing of memory
between different iterations of a map.

This slightly speeds up eval, but not significantly. Future work might
include benchmarking whether using a `HashMap` and only ordering in
cases where order is actually required would help.

This switches to a fork of `im` that fixes some bugs with its OrdMap
implementation.

Change-Id: I2f6a5ff471b6d508c1e8a98b13f889f49c0d9537
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7676
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-12-29 17:44:56 +00:00
Vincent Ambo
610c44ec1e refactor(tvix/eval): use im::Vector directly where possible
The conversion from im::Vector -> Vec is cheaper for NixList
construction (of course), so where possible we should make use of
that.

This updates most builtins dealing with lists to use Vector directly,
and marks the function constructing NixList from Vec as deprecated so
that we get appropriate warnings in places where it's still in use.

These places are currently inside of JSON serialisation logic which is
in flux right now, so lets leave them as-is until it's stabilised.

Change-Id: I037f12a2800f2576db4d9526bd935efd079163f0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7671
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-12-29 16:33:14 +00:00
Vincent Ambo
5d73c06b1a refactor(tvix/eval): use im::Vector for NixList representation
This is a persistent, structurally sharing data structure which is
more efficient in some of our use-cases. I have verified the
efficiency improvement using `hyperfine` repeatedly over expressions
on nixpkgs.

Lists are not the most performance-critical structure in Nix (that
would be attribute sets), but we can already see a small (~5-10%)
improvement.

Note that there are a handful of cases where we still go via `Vec`
that need to be fixed, most notable for `builtins.sort` which can not
currently be implemented directly using `im::Vector` because of a
restrictive type bound.

Change-Id: I237cc50cbd7629a046e5a5e4601fbb40355e551d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7670
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-12-29 12:27:59 +00:00
Vincent Ambo
71174f6626 fix(tvix/eval): fix current clippy warnings
It's been a while since the last time, so quite a lot of stuff has
accumulated here.

Change-Id: I0762827c197b30a917ff470fd8ae8f220f6ba247
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7597
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-25 18:25:06 +00:00
Adam Joseph
e04b1697e4 feat(tvix/eval): wrap Closure in Rc<> to match cppnix semantics
Change-Id: I595087eff943d38a9fc78a83d37e207bb2ab79bc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7443
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 14:50:04 +00:00
Lyle Mantooth
f4e17caae8 feat(tvix/eval): Continue removing leakage of BTreeMap.
Fixes b/212. Based on feedback in https://cl.tvl.fyi/c/depot/+/7492, all
uses of `NixAttrs::from_map` have been removed. Only `from_iter` and
`from_kv` remain.

Change-Id: I52e25f73018c2aa1843197427516b7a852503e2c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7500
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: IslandUsurper <lyle@menteeth.us>
2022-12-03 13:26:51 +00:00
Lyle Mantooth
39dba6aa16 feat(tvix/eval): impl FromIterator for NixAttrs
Allows for the removal of some BTreeMap usage when constructing NixAttrs
by allowing any iterator over 2-tuples to build a NixAttrs. Some
instances of BTreeMap didn't have anything to do with making NixAttrs,
and some were just the best tool for the job, so they are left using the
old `from_map` interface.

Change-Id: I668ea600b0d93eae700a6b1861ac84502c968d78
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7492
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-12-02 14:46:47 +00:00
Adam Joseph
a87abd5eed feat(tvix/eval): placeholder for builtins.placeholder
Change-Id: I8d11f2db4489a7d82910256069d10f8bed3bdf9a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7451
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2022-12-01 10:30:43 +00:00