Commit graph

1180 commits

Author SHA1 Message Date
Florian Klink
27c07b72c6 refactor(tvix): use io::Result for EvalIO
This is just a alias for Result<_, io::Error>, but shorter.

Change-Id: I7c22f61b85e3014885a747b5c1e5abd11b0ef17d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10327
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-12-12 14:28:50 +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
ae28dc3ca6 test(tvix/eval): test for b/338 catchable hygiene problem
Commit 05f42519b5 fixed b/281 by
establishing a hygiene regimen to partition *catchable* errors
(i.e. those which tryEval can detect) from all other errors, like
internal VM failures or I/O errors (which Nix must not be allowed to
detect, since these errors are fundamentally impure).

Unfotunately there are still cases where tvix assumes that anything
other than Value::Bool means it should panic!().  I found another
one, and added a test case for it in:

  eval_okay_src_tests_tvix_tests_eval_okay_compare_ordering_catchable_nix

Not yet passing.

Change-Id: I69c62ed9ea5c8f81870e8de5c5fe12dcde849763
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10220
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
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
Adam Joseph
19d13eb070 test(tvix/eval): add test case for b/339
Not yet passing.

Change-Id: I1de3f72d8b3f46567fdba010fc3ab4bace3f1699
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10219
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-12-12 14:26:46 +00:00
Adam Joseph
72ece2e518 feat(tvix/eval): nonrecursive nix_eq()
This commit rewrites Value::nix_eq() into an equivalent.  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 believed that the nonrecursive form would be faster.  It is, in
fact, slightly slower.  I believe this is due to the vec![]
allocation; I am investigating.

Prev-Nixpkgs-Benchmark: {"attrpath":"pkgsCross.aarch64-multiplatform.hello.outPath","peak-kbytes":"459068","system-seconds":"0.71","user-seconds":"5.39"}
This-Nixpkgs-Benchmark: {"attrpath":"pkgsCross.aarch64-multiplatform.hello.outPath","peak-kbytes":"460048","system-seconds":"0.68","user-seconds":"5.73"}
Change-Id: I10f4868891e4b7475df13f0cbc41ec78dd985dd8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10118
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-12-12 14:26:46 +00:00
Florian Klink
01a3c87a3a chore(tvix): bump criterion to 0.5
Change-Id: I28904ca23437b4bb745c0eb1f4eb9ae33e09eb5a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10244
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-12-11 03:59:30 +00:00
Florian Klink
d3ecef1a5b refactor(tvix/eval): address clippy lints
Change-Id: Ic2bd4e8291b30ceac9fa0e88a4f56e61ae99b603
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10227
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-12-09 12:58:39 +00:00
Adam Joseph
5fd42a9e70 feat(tvix/eval): impl DoubleEndedIter for OwnedAttrsIterator
Change-Id: I4bd85dbe9c27047f4abbdeff4e2b796e9bcab3a1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10211
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-12-09 11:35:19 +00:00
Adam Joseph
49b34183e3 feat(tvix/eval): rewrite Thunk::force() in nonrecursive form
This commit rewrites Thunk::force() so that it is not (directly)
self-recursive.  It maintains a Vec of all the
previously-encountered thunks which point to the one it is currently
forcing, rather than recursively calling itself.

Benefits:

- Short term:

  This commit saves the cost of a round-trip through the generator
  machinery for the generators::request_force() which is removed by
  this commit.

- Medium term:

  Once a similar transformation has been applied to nix_cmp(),
  nix_add(), nix_eq(), and coerce_to_string(), those four functions,
  along with Thunk::force(), will make non-tail calls only to each
  other.  They can then be merged into a single tail-recursive
  function which does not use the generator machinery at all:

    enum Task { Cmp, Add, Eq, CoerceToString, Force};

    fn Value::walk(task:Task, v1:Value, v2:Value) {
      // ...

- Long term:

  The long-term goal here is to use generators **only for builtins**
  and [Marionette]-style remote control of the VM.  In other words:
  use `async` for things that actually involve concurrency.  Calls
  from the VM to builtins can then be blocking calls, because even
  cppnix will overflow the stack if you make a MAX_STACK_DEPTH-deep
  recursive call which passes through a builtin at every stack frame
  (e.g. `{ func = builtins.sort (a: b: ... func ...) ...}`).

  This way the inner "tight loop" of the interpreter doesn't pay the
  costs of `async` and generators.  These costs manifest in terms
  of: performance, complex nonlocal control flow, and language
  impediments (async Rust is a restricted subset of real Rust, and
  is missing things like traits).

[Marionette]: https://firefox-source-docs.mozilla.org/testing/marionette/Intro.html

Change-Id: I6179b8abb2ea0492180fcb347f37595a14665777
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10039
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-12-06 06:53:01 +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
5ffb997864 fix(tvix): ensure PartialOrd/Ord agree for StorePath & NixString
This fixes a *future* clippy lint:
https://rust-lang.github.io/rust-clippy/master/index.html#/incorrect_partial_ord_impl_on_ord_type

In essence, because the implementation of *both* Ord and PartialOrd
implies that ordering is not partial, all results of PartialOrd should
simply be those of Ord. This is to avoid subtle bugs in future
refactorings.

Change-Id: I8fc6694010208752dd47746a2aaaeca0c788d574
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10109
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-11-25 15:48:46 +00:00
Adam Joseph
512346ba0b refactor(tvix/eval): add ThunkRepr::is_forced()
Change-Id: I4eab5c81fb82337da06327248845cd2f3a4490d3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10038
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-11-25 02:55:57 +00:00
Adam Joseph
b5a15989cd feat(tvix/eval): add Thunk::unwrap_or_clone()
This commit adds Thunk::unwrap_or_clone(), which uses
Rc::try_unwrap() to avoid cloning the Value out of a an Rc which has
only one strong reference.

Change-Id: Icacefe0c823dcddf046d90c0c5cd5ed59fe976d4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10037
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-11-25 02:55:56 +00:00
sterni
c5961e7774 docs(tvix/eval): optimization potential for inherit (from) exprs
Change-Id: Ibddaa111a5b7a86c42dbe153ae8e53f9a5601a54
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10112
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
2023-11-24 23:36:15 +00:00
Vincent Ambo
7c32d85455 docs(tvix/eval): document where EvalIO methods are used
Change-Id: I335f2ba4420973861c2a22125995b45a34d3608c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9969
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-11-06 09:06:26 +00:00
Vincent Ambo
f325456cba chore(tvix): bump proptest dependency
This *might* contain a fix for a clippy lint thrown by that crate.

Relates to b/321.

Change-Id: Ia7ebd3e26e0feb8bcc7a6c811b1e583f9016fd9e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9966
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
2023-11-05 20:28:38 +00:00
Vincent Ambo
87d3fac676 chore(tvix): add missing clippy attributes & config
For cases where clippy lints don't apply to us, or something is
misfiring, add appropriate configuration.

Relates to b/321.

Change-Id: I0af453910b4a4112bf685b2a8e9a73de10ec87ea
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9965
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-11-05 20:28:38 +00:00
Vincent Ambo
2e1399698b refactor(tvix/eval): use IntoIterator trait for owned NixAttrs iter
Uses the standard library IntoIterator trait for the construction of
our iterators. Clippy complains about duplicating this.

While doing this, I opted to rename the `IntoIter` type into something
that is more useful to users, in case somebody ends up working with
these manually.

This fixes a clippy lint, and is related to b/321.

Change-Id: I851fde0d7b8b38d182343a0fd6d9f8dd2a33ee11
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9963
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
2023-11-05 20:28:38 +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
99f618bcb4 refactor(tvix/eval): delay allocation when comparing attr values
Delays allocation (through cloning) of the values to be compared
until *after* the keys have been compared.

Change-Id: I7d68c27d7a0fbcdcc387db7c092bce50ca4b94ea
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9900
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-11-03 09:24:31 +00:00
Vincent Ambo
2dd2b844c7 chore(tvix/eval): add a marker for sorted borrowed attrs iteration
Similar to `into_iter_sorted`, add a marker function for call sites
that want *borrowed* sorted iteration.

Change-Id: I7c6f14e1ac43fdb14b861b3da183eb5d12bba139
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9899
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-11-03 09:24:31 +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
Florian Klink
1571d7195e fix(tvix/eval/benches): use black_box properly
The purpose of black_box is to actually prevent the compiler from being
able to optimize computation of the benchmarked function away.

To accomplish this, we need to actually *use* black_box to blackbox the
input data away, rather than the return type.

Change-Id: I5438982f57509fbf7b85034346a2739d76aef1fa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9902
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-11-02 20:39:52 +00:00
Florian Klink
269ab866f1 refactor(tvix/eval/tests): migrate to tempfile
tempdir pulls in remove_dir_all 0.5.3 with
https://rustsec.org/advisories/RUSTSEC-2023-0018.html, and we use
tempfile everywhere else too, so let's just migrate to that.

Change-Id: I735ade7b65e12fc26e3d43ca95fcfa07fcc64642
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9565
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-10-08 22:47:33 +00:00
Adam Joseph
fac32d0a5f feat(tvix/eval): test case for b/281
This commit adds a test case for b/281.

Change-Id: I8dfbfc0ff636184d7882530d8aefb329a3af9e5c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9288
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: flokli <flokli@flokli.de>
2023-09-26 14:13:05 +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
Florian Klink
731996fbfe docs(tvix/eval): fix some broken docstr references
There's some more left, but they've been renamed/refactored out of
sight.

Change-Id: I41579dedc74342b4c5f8cb39d2995b5b0c90b0f4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9372
Tested-by: BuildkiteCI
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Autosubmit: flokli <flokli@flokli.de>
2023-09-22 09:14:33 +00:00
Adam Joseph
9256621009 fix(tvix/eval): update identifier quoting to match cppnix 2.17
In cppnix 2.17, commit b72bc4a972fe568744d98b89d63adcd504cb586c, the
libexpr pretty-printing routine was fixed so that it would no longer
pretty-print attrsets with keywords in their attrnames incorrectly.

This commit implements the corresponding fix for tvix, fixes our
tests to work with cppnix>=2.17 oracles, and expands our test cases
to cover all the keywords.

Change-Id: I4b51389cd3a9c44babc8ab2a84b383b7b0b116ca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9283
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-09-15 00:00:59 +00:00
Adam Joseph
6fa80ecc3d fix(tvix/eval): make compare_strict_eval_tests use Strict
Previously, compare_strict_eval_tests() was using Strictness::Lazy.
This appears to be a minor oversight from
0ab6494286.

This commit corrects that, by changing Strictness::Lazy to
Strictness::Strict.

Change-Id: Ia2389a5d30481cd322ed55230731340b795e5d87
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9282
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-09-09 16:11:57 +00:00
Vincent Ambo
d546b9a15d docs(tvix/eval): document remaining opcodes
Change-Id: Iad8a5f78930872719b6481ddf1bbad8532bfa888
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7981
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-09-08 21:38:42 +00:00
Vincent Ambo
35e8dc97cf docs(tvix/eval): document attribute set related opcodes
Change-Id: Ib98a9fe8c9aa3f0e61c27d10285c0926cda7a969
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7979
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-09-08 21:38:42 +00:00
Vincent Ambo
3cf37c7cb6 docs(tvix/eval): add documentation strings for some OpCode variants
Change-Id: I42e610740b3687e1fd897d36694cce425751a8bc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7975
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
2023-09-08 21:38:42 +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
366e11b48a refactor(tvix/eval): don't use format! in write! args
Change-Id: I0b2fdb418c2e36280d5c551a81634e1742193903
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9105
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-08-20 21:52:21 +00:00
Florian Klink
c67b18bf45 refactor(tvix/eval/vm): don't put HashMap in a Box
HashMap already is on the heap.

Change-Id: I53763e17469359e85862f297b5c2e7c0d8c3a980
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9104
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-08-20 21:52:21 +00:00
Florian Klink
aead2001d7 refactor(tvix/eval): impl Default for SourceCode
… instead of new(). Suggested by clippy.

Change-Id: Iac7be733392afefc2b4ff2e38386eee95f3bce94
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9103
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-08-20 21:52:21 +00:00
Florian Klink
cf1a884ec5 refactor(tvix/eval/observer): cargo clippy
Change-Id: I11d7d55f31ddd27952f201a0abbed7445013f434
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9102
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-08-20 21:51:04 +00:00
Florian Klink
1a99b10b7e refactor(tvix/eval): cargo clippy
This passes a unit value to the function.

Change-Id: I4df3ad8fb0f35c0f110cee3349971ae28ce2878c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9101
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-08-20 21:51:04 +00:00
Florian Klink
ded577a73b refactor(tvix/eval/io): cargo clippy &Path
Change-Id: Ifec2a4fc93c482e41ff5993183643b5126a7728b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9100
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-08-20 21:51:04 +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
Florian Klink
1f02dc7eba refactor(tvix/eval): cargo clippy &GenCo
Change-Id: I6b1b902ccbc12bf2acdb0fdf406d6ef336ff0b2f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9098
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2023-08-20 21:51:04 +00:00
Florian Klink
690884426b refactor(tvix/eval): derive default for value::AttrsRep enum
Change-Id: Iaeb9ed7024c2ce85373f8aec0d223f52e1a3a539
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9097
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-08-20 21:51:04 +00:00
Vincent Ambo
8478448146 fix(tvix/eval): fix a comment position in value::json
Change-Id: Ic58653254b36694f1991a18db9ceea0d532c2e31
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9068
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-08-13 15:58:38 +00:00
sterni
8fb4c949dc test(tvix/eval): check truncation direction of builtins.div
builtins.div ought to truncate towards zero so that

    -(builtins.div a b) == builtins.div (-a) b
    -(builtins.div a b) == builtins.div a (-b)

Change-Id: I8b7c08cd7f4fa8a1363c786d42c8d484f6cd133d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9006
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-08-11 22:22:30 +00:00
Florian Klink
432222f098 feat(tvix/store/proto): use Bytes instead of Vec<u8>
Makes use of https://github.com/tokio-rs/prost/pull/341, which makes our
bytes field cheaper to clone.

It's a bit annoying to configure due to
https://github.com/hyperium/tonic/issues/908, but the workaround does
get the job done.

Change-Id: I25714600b041bb5432d3adf5859b151e72b12778
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8975
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
2023-07-22 09:03:02 +00:00
Florian Klink
72e82ffcb1 refactor(tvix/store): use bytes for node names and symlink targets
Some paths might use names that are not valid UTF-8. We should be able
to represent them.

We don't actually need to touch the PathInfo structures, as they need to
represent StorePaths, which come with their own harder restrictions,
which can't encode non-UTF8 data.

While this doesn't change any of the wire format of the gRPC messages,
it does however change the interface of tvix_eval::EvalIO - its
read_dir() method does now return a list of Vec<u8>, rather than
SmolStr. Maybe this should be OsString instead?

Change-Id: I821016d9a58ec441ee081b0b9f01c9240723af0b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8974
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-07-21 19:01:49 +00:00
sterni
8adc9c56f2 docs(tvix): document when pointer equality is preserved in C++ Nix
This explicitly documents behavior of C++ Nix that goes against the
intuition you'd gather from this document: that e.g. a simple select
from an attribute set causes a value to no longer be pointer equal to
its former self.

The point of documenting this is that we can show in a to be written
section on the use of pointer equality in nixpkgs that pointer equality
is only needed in a limited sense for evaluating it (C++ Nix's exterior
pointer equality). Tvix's pointer equality is far more powerful since
value identity preserving operations also preserve pointer equality,
generally speaking (this is because we implement interior pointer
equality in my made up terminology). This should eventually also be
documented.

Change-Id: I6ce7ef2d67b012f5ebc92f9e81bba33fb9dce7d0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8856
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-07-11 16:17:42 +00:00
sterni
4ba624efae fix(tvix/eval): use byte, not codepoint index for slicing in escape
This fixes a subtle issue which would occasionally lead to a crash (e.g.
when evaluating (pkgs.systemd.outPath with --trace-runtime): With each
character in the string that has a multi byte representation in UTF-8,
the actual byte position and what tvix thought it was would get out of
sync. This could either lead to

* Tvix swallowing characters or jumbling characters if multi byte
  characters would cause the tracked index to become out of sync with
  the byte position before the first character to be escaped, or

* Tvix crashing if (in the same situation) the out of sync index would
  be within a UTF-8 byte sequence.

Luckily, std's `char_indices()` iterator implements exactly what
`nix_escape_char()`'s original author had in mind with
`.chars().enumerate()`. Using `i + 1` for continuing is safe, since all
characters that need (in fact, can) to be escaped in Nix are represented
as a single byte in UTF-8.

Change-Id: I1c836f70cde3d72db1c644e9112852f0d824715e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8952
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-07-11 16:11:40 +00:00
Florian Klink
5796563f1f chore(tvix/eval/vm): drop unused import
Change-Id: Ia04778391c198fde21da217bf697aa40157898b0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8846
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-06-30 12:42:59 +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
sterni
66047063e0 fix(tvix/eval): use realpaths for import cache
I've noticed this behavior when writing the admittedly cursed test case
included in this CL. Alternatively we could use some sort of machinery
using `builtins.trace`, but I don't think we capture stderr anywhere.

I've elected to put this into the eval cache itself while C++ Nix does
it in builtins.import already, namely via `realisePath`. We don't have
an equivalent for this yet, since we don't support any kind of IfD, but
we could revise that later. In any case, it seems good to encapsulate
`ImportCache` in this way, as it'll also allow using file hashes as
identifiers, for example.

C++ Nix also does our equivalent of canon_path in `builtins.import`
which we still don't, but I suspect it hardly makes a difference.

Change-Id: I05004737ca2458a4c67359d9e7d9a2f2154a0a0f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8839
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-21 07:48:52 +00:00
sterni
4516cd09c5 fix(tvix/eval): only finalise formal arguments if defaulting
When dealing with a formal argument in a function argument pattern that
has a default expression, there are two different things that can happen
at runtime: Either we select its value from the passed attribute
successfully or we need to use the default expression. Both of these may
be thunks and both of these may need finalisers. However, in the former
case this is taken care of elsewhere, the value will always be finalised
already if necessary. In the latter case we may need to finalise the
thunk resulting from the default expression. However, the thunk
corresponding to the expression may never end up in the local's stack
slot. Since finalisation goes by stack slot (and not constants), we need
to prevent a case where we don't fall back to the default expression,
but finalise anyways.

Previously, we worked around this by making `OpFinalise` ignore
non-thunks. Since finalisation of already evaluated thunks still
crashed, the faulty compilation of function pattern arguments could
still cause a crash.

As a new approach, we reinstate the old behavior of `OpFinalise` to
crash whenever encountering something that is either not a thunk or
doesn't need finalisation. This can also help catching (similar)
miscompilations in the future. To then prevent the crash, we need to
track whether we have fallen back or not at runtime. This is done using
an additional phantom on the stack that holds a new `FinaliseRequest`
value. When it comes to finalisation we check this value and
conditionally execute `OpFinalise` based on its value.

Resolves b/261 and b/265 (partially).

Change-Id: Ic04fb80ec671a2ba11fa645090769c335fb7f58b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8705
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-20 10:07:44 +00:00
sterni
77b0dddc3d chore(tvix/eval): fix markdown labeled link syntax
Change-Id: I639dc0801090eaba56b61858e28204b5a0e631b6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8784
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-15 19:40:08 +00:00
sterni
3b8c9ec9c8 test(tvix/eval): update nix_tests suite to C++ Nix master
Adds new tests for foldl', intersectAttrs as well as fills in missing
.exp files.

New test cases we don't pass:

- fromTOML timestamp capabilities
- path antiquotation
- replaceStrings is lazier on C++ Nix master

The C++ Nix revision used is 7066d21a0ddb421967980094222c4bc1f5a0f45a.

Change-Id: Ic619c96e2d41e6c5ea6fa93f9402b12e564af3c5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8778
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-06-15 19:28:16 +00:00
sterni
9278a0cd16 docs(tvix/eval): update test suite documentation
Change-Id: Ie9153c00b95ede4837a8eeab341e68bc90e97921
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8777
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-15 19:28:16 +00:00
sterni
0f71d8f813 test(tvix/eval): genericClosure (pointer) comparison support
genericClosure has very limited support for pointer equality: It relies
on comparison (not equality!) in C++ Nix, so as soon as C++ Nix supports
comparing lists (langVersion >= 6) we can rely on pointer equality for
key.

Since Tvix uses equality, not comparison for the insert, our behavior is
currently different, as documented by the notyetpassing tests.

Change-Id: Ifcd741ed4fc3ccc3825f7038875d56a9918b786a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8720
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-15 11:01:06 +00:00
sterni
0005737f11 fix(tvix/eval): make tvix display values like nix-instantiate(1)
In order for the test suite we have currently to be comparable to C++
Nix, we need to display values in the same way. This was largely the
case except in some weird cases.

* <CODE> for thunks and <CYCLE> for repeated thunks (?) are already in
  use. <CODE> formatting is tested by the oracle test suite already.

* Instead of lambda, we need to use <LAMBDA>

* <<primop>> and <<primop-app>> (a formatting C++ Nix uses nowhere)
  now are <PRIMOP> and <PRIMOP-APP>.

We'll probably want to have a fancier display of values (in a separate
trait) down the line. This could be used for interactive usage, e.g. the
REPL or a potential debugger.

There is a peculiarity with C++ Nix 2.3 formatting primops: import is
considered a <<PRIMOP-APP>>, since it is internally implemented by means
of scopedImport. This implementation detail no longer leaks in C++ Nix
2.13 nor in Tvix.

<CYCLE> display is untested at the moment, since we exhibit a
discrepancy to C++ Nix 2.3. Our current detection is more similar to C++
Nix 2.13—luckily it is also the more consistent of the two. See also
b/245.

Change-Id: I1d534434b02e470bf5475b3758920ea81e3420dc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8760
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-06-15 11:01:06 +00:00
sterni
e409d9cc7e docs(tvix/eval): fix link to tvixbolt
Change-Id: Iff3f74ab6d5177246811bd3d58d171088915370f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8775
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-14 16:22:07 +00:00
sterni
80a71abb48 test(tvix/eval): move division by zero tests into tvix_tests
These were added by us in r/5276, so they should go into our test suite.

Change-Id: I6dc74fc242f33c22a17e0b4aee546ccae886ac85
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8774
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-14 16:22:07 +00:00
sterni
1125b6b7b7 test(tvix/eval): add test case for builtins set pointer equality
Unsupported by Tvix at the moment. Documents b/280.

Change-Id: I48844feeefa9da8ed7e5d85300d52bb5650f82d2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8772
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-14 16:01:19 +00:00
sterni
d5b989ddc0 test(tvix/eval): re-enable blackhole test
Change-Id: Id933f3bd708aa3342b9fd6a5584e65ee11751ff8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8773
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-14 15:59:45 +00:00
sterni
8e5551329a fix(tvix/eval): don't thunk home relative paths
C++ Nix resolves home relative paths at [parse] time. This is not an
option for us, since it prevents being able to separate the compilation
and execution phase later (e.g. precompiled nix expressions). However, a
practical consequence of this is that paths expressions are always
literals (strict) and never thunks.

[parse]: 7066d21a0d/src/libexpr/parser.y (L518-L527)

Change-Id: Ie4b9dc68f62c86d6c7fd5f1c9460c850d97ed1ca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7041
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-14 10:57:28 +00:00
sterni
5139cc45c2 test(tvix/eval): builtins.substring's behavior with negative args
Change-Id: Ie8b97d174e9d58e33bf08c9b9e0afeeddd089ba8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8700
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-06-12 09:38:08 +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
Linus Heckemann
2b4ad47c16 fix(tvix/eval): emit only warnings on shadowed outputs
Unfortunately, nixpkgs has at least one case[1] where the out environment
variable is shadowed -- though it doesn't cause a problem, since it's
shadowed with the correct value, odd as this may be!

[1]: c7c2984716/pkgs/development/python-modules/pybind11/default.nix (L19)

Change-Id: Ibf6790d2484dc9cce8e424feeb5886664d498dc3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8696
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-11 20:59:34 +00:00
sterni
a2303da01f fix(tvix/eval): use normal thunking behavior for default in formals
When comparing to C++ Nix, we notice that the thunking of default
expressions in function formals corresponds to their normal thunking,
e.g. literals are not thunked. This means that we can just invoke
compile() without much of a care and trust that it will sort it out
correctly.

If function formals blow up as a result of this, it likely indicates
that the expression is treated incorrectly by compile(), not
compile_param_pattern().

Change-Id: I64acbff2f251423eb72ce43e56a0603379305e1d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8704
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-07 15:19:21 +00:00
sterni
10c6cb7251 fix(tvix/eval): type check function argument with set pattern
C++ Nix forces and typechecks the passed argument even if it is not
necessary in order to compute the return value of the function. I
discovered this when I thought our formals miscompilation might be that
we are too strict, but doesn't look like it in this case.

Change-Id: Ifb3c92592293052c489d1e3ae8c7c54e4b6b4dc6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8701
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-07 15:17:20 +00:00
sterni
617130b088 refactor(tvix/eval): don't track idx twice in compile_param_pattern
Change-Id: I27f9105ddb20d84342550b2a73b479a7764ee3fe
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8699
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-06-07 15:17:19 +00:00
sterni
b492067c19 test(tvix/eval): check thunking behavior of basic exprs
nix_oracle.rs now gives us the possibility to check this by stuffing the
expressions in a list. In fact, the incorrect behavior fixed in

- cl/8656
- cl/8655
- cl/8662

was discovered using this test suite.

Change-Id: Id0ab01ee6be0b875791214e0a72a2ac941c46c96
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8658
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-29 19:36:42 +00:00
sterni
0ab6494286 refactor(tvix/eval/nix_oracle): allow specifying eval strictness
This will be useful for comparing thunking behavior to C++ Nix. I
considered adding this capability to the tvix_tests/nix_tests
infrastructure, but as it would require changing the test file naming
scheme to do it in a clean way, I've postponed it–it's nice that our
tests are compatible with C++ Nix's test suite.

Change-Id: I60bcdd98ed25140e716f0858f8dc28f21ab957aa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8657
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-05-29 19:36:41 +00:00
sterni
d09f333d0e fix(tvix/eval): thunk lambda expressions
As cl/8658 and b/274 reveal, lambda expressions are also wrapped in
thunks.

Resolves b/274.

Change-Id: I02fe5c8730ac76748d940e4f4427116587875275
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8662
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-29 19:36:41 +00:00
sterni
2aab01ac29 fix(tvix/eval): thunk HasAttr expressions
HasAttrs was weird because with longer attribute paths it would
sometimes not turn out to be a thunk. If it was a thunk, it'd usually
still do some eval strictly which we'll want to avoid.

Verified against C++ Nix using a new test suite introduced in a later
CL.

Change-Id: I6d047ccc68d046bb268462f170a3c4f3c5ddeffe
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8656
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-29 12:44:09 +00:00
sterni
9d0425acc0 fix(tvix/eval): thunk legacy let to match regular one
Probably no real world code broken by this overzealous evaluation, but
let's be thorough!

Change-Id: Ib405a677182eab7940ace940c68e107573473a54
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8655
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-05-29 12:44:08 +00:00
sterni
385c797884 fix(tvix/eval): thunk unary operator applications
Unary operator applications are thunked which can easily be observed by

  nix-instantiate --eval -E '[ (!true) (-1) ]'

Unfortunately, there are few simple expressions where this makes a
difference in the end result. Thus it only cropped up when using nixpkgs
for cross compilation: Here we would compile the expression

  !(stdenv.cc.isGNU or false)

to assemble python3Minimal's passthru attribute set (at least this seems
to be the most likely explanation from the backtraces I've studied).
This means that an unthunked

    <stdenv.cc.isGNU or false>
    OpForce
    OpInvert

would be performed in order to assemble this attribute set, causing
stdenv.cc to be evaluated too early, causing an infinite recursion.

Resolves b/273.

It seems that having a test suite that doesn't use --strict and relies
on thunks rendered as <CODE> would be beneficial for catching such
issues. I've not been able to find a test case with --strict that
demonstrates the problem fixed in this CL.

Change-Id: I640a5827b963f5b9d0f86fa2142e75e3a6bbee78
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8654
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-29 12:44:08 +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
22776280b5 feat(tvix/eval): unthunk empty lists and attribute sets
Change-Id: Ie66cb1b163a544d45d113fd0f866286f230b0188
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7960
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2023-05-25 11:28:13 +00:00
Vincent Ambo
5d3fb33baa feat(tvix/eval): implement unthunking in compiler
This feature allows the compiler to detect situations where the
created thunk is useless and can be merged into the parent chunk
instead.

The only case where the compiler does this initially is when
statically optimising a select expression.

For example, previously the expression `builtins.length` compiled into
two thunks:

1. An "inner" thunk which contained an `OpConstant` that had the
   optimised `length` builtin in it.

2. An "outer" thunk which contained an `OpConstant` to access the
   inner thunk, and the trailing OpForce of the top-level program.

With this change, the inner thunk is skipped completely and the outer
chunk directly contains the `length` builtin access.

This can be applied in several situations, some easier than others,
and we will add them in as we go along.

Change-Id: Ie44521445fce1199f99b5b17712833faea9bc357
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7959
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-05-25 11:28:13 +00:00
Vincent Ambo
3aea9bf527 feat(tvix/eval): implement Chunk::extend method
This method extends the contents of one chunk with that of another,
effectively merging the thunks together.

This will be used for the upcoming "unthunking" functionality.

Change-Id: I6ad74232cd7f3eca198ed921e455205e00d76e6b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7958
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-05-25 11:28:13 +00:00
Florian Klink
d25962b9a4 refactor(tvix/eval): stop borrowing &mut self
This does undo cl/8571.

Change-Id: Ib14b4e7404f906e346304b6113860ae811afc94a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8631
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
2023-05-25 11:11:59 +00:00
Florian Klink
11771a06ae refactor(tvix/eval): use &Path instead of PathBuf
This allows getting rid of some clones in eval/src/vm/generators.rs.

Change-Id: I330390307d3bcfeef19c98954c753ee55b1ccee3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8604
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-22 09:43:33 +00:00
Florian Klink
b4bb9062ea fix(tvix/eval): add path where useful to ErrorKind::IO
These two places didn't add the path from the context to the
ErrorKind, but simply relied on the
impl From<std::io::Error> for tvix_eval::ErrorKind, which doesn't add
the path.

Change-Id: Ifc7dbbe305d24242b0705de1dea34e8923e9d2cb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8603
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
2023-05-22 09:43:21 +00:00
Florian Klink
b7ab6c0856 refactor(tvix/eval/io): use io::Error instead of tvix_eval errors
We didn't return anything useful other than ErrorKind::IO anyways.

We can use io::ErrorKind::Unsupported for DummyIO.

Fixes b/271.

Change-Id: Icb231e9b38168e8b6fa473bfa405d160357b317f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8602
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-22 09:42:58 +00:00
Florian Klink
8bd7ced1fb feat(tvix/eval/io): allow &mut self in EvalIO
It's okay if these calls mutate some internal state inside an
implementation.

Change-Id: I12bb11bde0310778c3da1275696bf7de058863a3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8571
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-14 18:59:55 +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
Florian Klink
6a30eb69e0 chore(tvix/*): bump to smol_str 0.2.0
Change-Id: Ic9ac1b6fecb564eafb41b265bf317cd385fdc170
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8560
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2023-05-11 18:19:20 +00:00
Vincent Ambo
ce502bdc89 refactor(tvix/eval): improve representation of chunk/span mapping
This switches out the previous compressed representation (count of
instructions per span) with a representation where the chunk's span
list stores the index of the first operation that belongs to a span,
and finds the right span by using a binary search when looking them
up.

This improves the lookup complexity from O(n) to O(log n).

This improvement was suggested and (mostly) implemented by GPT-4. I
only fixed up some names and updated the logic for deleting
spans (which it only did not do because I didn't tell it about that).

The code was verified by producing a complex error before/after the
change and ensuring that all spans in the error match exactly.

Co-Authored-By: GPT-4
Change-Id: Ibfa12cc6973af1c9b0ae55bb464d1975209771f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8385
Reviewed-by: ezemtsov <eugene.zemtsov@gmail.com>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-03-31 16:46:19 +00:00
Vincent Ambo
2d305fd5b3 refactor(tvix/eval): retain call frames when entering calls
This grows the frame stack as the call stack grows, which yields *much*
better user-facing error messages.

I haven't measured the performance impact this has yet, for now I'm
still just trying to add more information to errors and then cut down
again where necessary.

Change-Id: I89f058ef31979edacf4667775d460b60704ce4d7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8334
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-03-27 09:02:43 +00:00
Vincent Ambo
ba138712e4 feat(tvix/eval): add Evaluation::strict to toggle top-level deepseq
This makes it possible for callers to control whether they can receive
partially evaluated values from an evaluation or not.

We're actually flipping the default behaviour to non-strict top-level
evaluation, which means that callers have to set `strict = true` on
the Evaluation to get the previous behaviour.

Change-Id: Ic048e9ba09c88866d4c3177d5fa07db11c4eb20e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8325
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-03-22 13:44:20 +00:00
Vincent Ambo
a5f28eea94 fix(tvix/eval): print unevaluated thunks like Nix does
Change-Id: Ie4c563e933f571f45cb4f4efe650d1b65f119e8d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8324
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
2023-03-22 13:44:19 +00:00
Vincent Ambo
80aaadfc19 fix(tvix/eval): use span of set for OpForce in attribute access
Emits the span of the `set` that is being accessed in the `force`
operation of an attribute access.

Looking at traces, it's a lot more useful to get information about
*what* is being forced, as in cases like `foo.bar` it can be
misleading to have an error highlight `bar`, when the error occured
while forcing `foo` to be able to access `bar` in the first place.

Change-Id: Id46ff28f20c67cb4971727ac52cc4811795cea2d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8272
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-03-17 19:40:40 +00:00
Vincent Ambo
8c13f18d11 feat(tvix/eval): report all known spans on infinite recursion
This reports the span

1. of the code within a thunk,
2. of the place where the thunk was instantiated,
3. of the place where the thunk was first forced,
4. of the place where the thunk was forced again,

when yielding an infinite recursion error, which hopefully makes it
easier to debug them.

The spans are tracked in the ThunkRepr::Blackhole variant when putting
a thunk under evaluation.

Note that we currently have some loss of span precision in the VM loop
when switching between frame types, so spans 3/4 are currently a bit
wonky. Working on it.

Change-Id: Icbd2a9df903d00e8c2545b3fc46dcd2a9e3e3e55
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8270
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-03-17 19:32:38 +00:00
Vincent Ambo
3fa6b13c1e feat(tvix/eval): track span of first force in a thunk blackhole
This is step 1 towards being able to use all 4 spans that we know when
dealing with infinite recursion. It tracks the span at which the
force of a thunk was first requested when constructing a blackhole, so
that we can highlight the spans of the first and second forces.

These are actually the least relevant spans, but the easiest to put in
place, more coming soon.

Change-Id: I4c7e82f6211b98756439d4148a4191457cc46807
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8269
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-03-17 19:31:37 +00:00
Vincent Ambo
5095e4f269 feat(tvix/eval): add generator "name" to NativeError kind
This produces traces in which we can see what kind of native code was
run. Note that these "names" are named after the generator message, so
these aren't *really* intended for end-user consumption, but we can
give them saner names later.

Example:
https://gist.github.com/tazjin/82b24e92ace8e821008954867ee05057

This already makes the traces a little easier to parse.

Change-Id: Idcd601baf84f492211b732ea0f04b377112e10d0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8268
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-03-17 19:31:37 +00:00
Vincent Ambo
ea80e0d3f8 feat(tvix/eval): enrich errors with VM's frame stack information
When emitting an error at runtime, the VM will now use the new
`NativeError` and `BytecodeError` error kinds (which just wrap inner
errors) to create a set of diagnostics to emit.

The primary diagnostic is emitted last, with `error` type (so it will
be coloured red in terminals), the other ones will be emitted with
`note` type, highlighting the causal chain.

Example:
https://gist.github.com/tazjin/25feba7d211702453c9ebd5f8fd378e4

This is currently quite verbose, and we can cut down on this further,
but the purpose of this commit is to surface more information first of
all before worrying about the exact display.

Change-Id: I058104a178c37031c0db6b4b3e4f4170cf76087d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8266
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-03-17 19:31:37 +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
Adam Joseph
32999cb6f6 docs(tvix/eval): suggested layout adjustment to VM loop diagram
Change-Id: I5467cd66801ad8fe6c4ec0ae337763f1762cea1c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8252
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-03-14 09:56:28 +00:00
Vincent Ambo
466e6dc265 docs(tvix/eval): document inner workings of the new VM loop
Change-Id: I8224bf039f739c401900b5a2ddc839810c87cf6e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8226
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
2023-03-14 09:22:32 +00:00
Vincent Ambo
d456705352 chore(tvix): Generator{Request|Response} -> VM{Request|Response}
We settled on this being the most reasonable name for this construct.

Change-Id: Ic31c45461a842f22aa05f4446123fe3a61dfdbc0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8291
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-14 09:22:22 +00:00
Adam Joseph
1e80b9ea8b chore(tvix/eval): mark async functions which are called by the VM
Given Rust's current lack of support for tail calls, we cannot avoid
using `async` for builtins.  This is the only way to avoid
overflowing the cpu stack when we have arbitrarily deep
builtin/interpreted/builtin/interpreted/... "sandwiches"

There are only five `async fn` functions which are not builtins
(some come in multiple "flavors"):

- add_values
- resolve_with
- force, final_deep_force
- nix_eq, nix_cmp_eq
- coerce_to_string

These can be written iteratively rather than recursively (and in
fact nix_eq used to be written that way!).  I volunteer to rewrite
them.  If written iteratively they would no longer need to be
`async`.

There are two motivations for limiting our reliance on `async` to
only the situation (builtins) where we have no other choice:

1. Performance.

   We don't really have any good measurement of the performance hit
   that the Box<dyn Future>s impose on us.  Right now all of our
   large (nixpkgs-eval) tests are swamped by the cost of other
   things (e.g. fork()ing `nix-store`) so we can't really measure
   it.  Builtins tend to be expensive operations anyways
   (regexp-matching, sorting, etc) that are likely to already cost
   more than the `async` overhead.

2. Preserving the ability to switch to `musttail` calls.

   Clang/LLVM recently got `musttail` (mandatory-elimination tail
   calls).  Rust has refused to add this mainly because WASM doesn't
   support, but WASM `tail_call` has been implemented and was
   recently moved to phase 4 (standardization).  It is very likely
   that Rust will get tail calls sometime in the next year; if it
   does, we won't need async anymore.  In the meantime, I'd like to
   avoid adding any further reliance on `async` in places where it
   wouldn't be straightforward to replace it with a tail call.

https://reviews.llvm.org/D99517

https://github.com/WebAssembly/proposals/pull/157

https: //github.com/rust-lang/rfcs/issues/2691#issuecomment-1462152908
Change-Id: Id15945d5a92bf52c16d93456e3437f91d93bdc57
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8290
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-03-13 21:33:58 +00:00
Adam Joseph
e7a534e0c6 refactor(tvix/eval): reduce fetch{forced|captured}_with visibility
This commit moves fetch_forced_with and fetch_captured_with into the
scope of their only caller (resolve_with).

Change-Id: I9a8bc27228888729d591e8cb021c431b2b6468f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8289
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-03-13 21:33:58 +00:00
Adam Joseph
47895c4c30 feat(tvix/eval): rewrite nix_cmp_ordering to be nonrecursive
This rewrites nix_cmp_ordering as an iterative loop, which
eliminates the extra pinned-boxing helper function.

Change-Id: I33d0ecc913e02affd8fd4c7bc1c9ecfdf4c7deb9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8288
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
2023-03-13 21:22:12 +00:00
Vincent Ambo
b3f8d66a6a chore(tvix/eval): prune some dependencies & features
* We no longer need backtrace-on-stack-overflow, as we no longer
  overflow the stack with the recent eval refactorings. This was weird
  voodoo anyways, introduced earlier to debug some cases where stack
  overflows occured.

* default features of genawaiter crate are not needed, as we don't use
  their proc macros

Change-Id: I346fc5a18d7f117ee805909a8be8f535b96be76c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8263
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
94513525b9 refactor(tvix/eval): reorder bytecode operations match by frequency
This reorders the operations in the VM's main `match` statement while
evaluating bytecode according to the frequency with which these
operations appear in some nixpkgs evaluations.

I used raw data that looks like this:
https://gist.github.com/tazjin/63d0788a78eb8575b04defaad4ef610d

This has a small but noticeable impact on evaluation performance.

No operations have changed in any way, this is purely moving code
around.

Change-Id: Iaa4ef4f0577e98144e8905fec88149c41e8c315c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8262
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
e48a17a6b3 docs(tvix/eval): fix reference to Empty message in a comment
Change-Id: I3dc30cca33fbbd8e8686655635ee471f5937d9f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8257
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
cc59cbf3e2 refactor(tvix/eval): rename VM::tail_call_value -> VM::call_value
The name of this was not accurate anymore after all the recent
shuffling, as noted by amjoseph. Conceptual tail calls here only occur
for Nix bytecode calling Nix bytecode, but things like a builtin call
actually push a new native frame.

Change-Id: I1dea8c9663daf86482b8c7b5a23133254b5ca321
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8256
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +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
43b0416bd8 fix(tvix/eval): more closely line up path resolution with cppnix
... except now the tests fail, but at least it works

Change-Id: I05e86c173f40533ae65548585c1ddaa200ac5235
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8214
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
c700776733 refactor(tvix/eval): VM struct no longer needs to be public
Change-Id: I93b485ddd280cc15fcbaecf4aed5fcd22e28a8a8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8212
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
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
1e37f8b52e feat(tvix/eval): give generators human-readable names
This adds static strings to generator frames that describe the
generator in a human-readable fashion, which are then logged in
observers.

This makes runtime traces very precise, explaining exactly what is
being requested from where.

Change-Id: I695659a6bd0b7b0bdee75bc8049651f62b150e0c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8206
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
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
a9f44721e5 refactor(tvix/eval): move __toString calling to a helper function
It turns out that this is used not just in coerceToString, but also in
toJSON.

Change-Id: I1c324b115a0b8bb6d83446d5bf70453c9b90685e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8203
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
54a12577c4 refactor(tvix/eval): print only *types* when observing generators
Do not print the entire value (they're likely to be thunks anyways).
This is useful because there *can* be cases where something like
`nixpkgs` itself is sent through one of these messages, in which case
the observer trying to print it will just blow up.

Change-Id: I1fa37ea071d75efa0eb3428c6e2fe4351c62be6b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8202
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
d9371c2f6f fix(tvix/eval): don't print full stack in observer
Print only the top 6 values of the stack, not the entire stack.
There's very few operations that deal with more values anyways, so the
rest are not likely to be useful.

This gets us one step closer to tracing VERY large executions without
blowing up.

Change-Id: I97472321b0321b25d534d9f53b3aadfacc2318fa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8201
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
19106cdaf0 fix(tvix/eval): don't print full values in observer
This can actually blow up when tracing arbitrary execution, as some of
the data structures just get too large to run through a tabwriter.

Change-Id: I6ec4c30ee48655b8a62954ca219107404fb2c256
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8200
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
fb4ea1f5a4 refactor(tvix/eval): condense observer's stack writing logic
Change-Id: I1282c3387ac1e0d1528b894814f2a495ca5a6a32
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8199
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
eef48b8f1f fix(tvix/eval): correctly thunk deferred formals access
Formals can be initialised with deferred default values (see the test
cases), in which case they need an extra thunk to have something that
can be finalised appropriately when the setup is done.

Fixes: b/255
Change-Id: I380e3770be68eaa83ace96d450c7cead32dacc9f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8196
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
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
52b7a76268 chore(tvix/eval): remove From<SmolStr> for NixString instance
No longer needed, and in some cases caused some extra work.

Change-Id: I64e8e7292573bdc92a9c7a8e470e33f8c526f311
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8152
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
1941082cbb refactor(tvix/eval): simplify NixString representation(s)
Instead of the two different representations (which we don't really
use much), use a `Box<str>` (which potentially shaves another 8 bytes
off `Value`).

NixString values themselves are immutable anyways (which was a
guarantee we already had with `SmolStr`), so this doesn't change
anything else.

Change-Id: I1d8454c056c21ecb0aebc473cfb3ae06cd70dbb6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8151
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: flokli <flokli@flokli.de>
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
83b2290e1b test(tvix/eval): add test for infinite recursion detection
Change-Id: Ief20544a44c3542fe40a5c09f81d0f064a346f44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8149
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
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
cbb4137dc0 feat(tvix/eval): implement generator-based Nix equality logic
Adds a `Value::neo_nix_eq` method (the `neo_` prefix will be dropped
when we flip over to the generator implementation of the VM) which
implements Nix equality semantics using async, generator-based
comparisons.

Instead of tracking the "kind" of equality that is being compared (see
the pointer-equality doc) through a pair of booleans, I've introduced
an enum that explicitly lists the possible comparisons.

Change-Id: I3354cc1470eeccb3000a5ae24f2418db1a7a2edc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8241
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
2023-03-13 20:30:59 +00:00
Vincent Ambo
cd447e1859 feat(tvix/eval): add generator-related functions to RuntimeObserver
These functions will be used by the changes in the VM to observe the
runtime execution of generator frames, and provide a more linear view
of the execution of the Tvix VM.

Change-Id: I10b1b1933dedc065e7c61d5d6062f0aaeee0097e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8240
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
2023-03-13 20:30:59 +00:00
Vincent Ambo
d00229753d feat(tvix/eval): implement asynchronous list sorting algorithm
In order to implement an asynchronous builtins.sort (required for
moving builtins to generators), we need an `async` sorting algorithm
as our comparators involve invoking a Nix function.

This commit implements a fairly simple, optimised bubble sort as the
sorting algorithm used in our `async fn sort_by`.

There don't seem to be any crates providing async versions of things
like this, and they might actually be pretty hard to implement
generically due to some constraints about how `async` works.

Note that this algorithm is less efficient than the hybrid
"timsort/mergesort/insert sort" used in the Rust standard library. I
tried to write a merge sort implementation, but ran into isuses with
the sort becoming unstable because our comparators can not yield
equality. This is the simplest implementation which I know to be
correct.

Note that as of this commit this is *not* covered by the Tvix test
suite, but it will be as soon as the rest of the generator code lands.

Change-Id: Ia9a604f7dd941d6acc9212c902e0e637ed75bebc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8239
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Florian Klink
c9c8b10370 feat(tvix/eval): don't warn twice about dead code
We currently send two warnings in case of detecting dead code - W008
inside compile_dead_code, and a more detailed warning in all places that
invoke compile_dead_code:

```
warning[W007]: useless operation on boolean: this expression is always false
     --> /nix/store/qz3gjn95gazab4fkb7s8lm6hz17rdzzy-414z9nnj1wy66ymq6vgb693x9xjz6hf2-nixpkgs-src/pkgs/top-level/perl-packages.nix:12079:15
      |
12079 |     doCheck = false && !stdenv.isDarwin;
      |               ^^^^^^^^^^^^^^^^^^^^^^^^^

warning[W008]: this code will never be executed
     --> /nix/store/qz3gjn95gazab4fkb7s8lm6hz17rdzzy-414z9nnj1wy66ymq6vgb693x9xjz6hf2-nixpkgs-src/pkgs/top-level/perl-packages.nix:12079:24
      |
12079 |     doCheck = false && !stdenv.isDarwin;
      |                        ^^^^^^^^^^^^^^^^
```

The place invoking `compile_dead_code` has more context to why the code
is unused, so it's error message is much more useful.

Stop emitting the less informative warning inside compile_dead_code
(W008), and update the comment that we expect the caller to emit a
warning.

I kept W008 itself still around, in case we end up having places this
will get used again.

Change-Id: I2c5d84fc0cb4035872cd4b71cc3e9e34e120eb37
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8024
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-11 14:26:49 +00:00
Vincent Ambo
2696839770 feat(tvix/eval): introduce generators module
This module contains the request/response types for generators
requesting actions from the VM.

For most of these, an async helper function is added that will be used
inside of generator functions to make use of these requests/responses
instead of constructing them directly.

Change-Id: I1e085f88adaf784a34867957a0e82532d3a83d7c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8148
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-07 22:04:59 +00:00
Vincent Ambo
9cebae9b56 refactor(tvix/eval): merge OpCall & OpTailCall
As applies are thunked, there was no situation where OpCall could be
emitted. In practice, all calls were already tail calls.

Change-Id: Id0d441dcdd86f804d7cddd0cc14f589bbfc75e5b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8147
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-07 22:04:59 +00:00
Vincent Ambo
bfb787a6c5 refactor(tvix/eval): remove VM argument from suspended native thunks
Because they do not use it, and it can not be passed with the coming
generator refactoring.

Change-Id: I0d96f2357a7ee79cd8a0f401583d4286230d4a6b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8146
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-04 15:53:36 +00:00
Vincent Ambo
38fd3cb292 refactor(tvix/eval): insert storeDir "builtin" in eval startup
Instead of using a suspended native thunk, calculate and optionally
insert the storeDir builtin when the VM is constructed.

We already have the IO handle available at this point and can just
check whether a storeDir is present, and insert its absolute value as
a builtin.

Change-Id: If966eee6ff26dc888b6e888e7c46170c0c346b05
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8145
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-04 15:53:36 +00:00
Vincent Ambo
e1f082a3ab feat(tvix/eval): add SharedThunkSet
This is a ThunkSet wrapped to be shareable, which will be required
once ThunkSets are embedded in futures.

Change-Id: I5a067b7972ac86e4d354c75ef05c86b2284c1137
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8144
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-04 15:18:37 +00:00
Vincent Ambo
dccbda5960 fix(tvix/eval): ThunkSet does not need mutable pointers
Change-Id: Iea248870a0ea5d38cb02ff059c968fbd563570b6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8143
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-04 15:18:37 +00:00
Vincent Ambo
8c7d5b4f87 chore(tvix/eval): implement From<OrdMap<..>> for NixAttrs
Again simplifying some code down the line, where bits of code that
construct attribute sets already have the final structure available.

Change-Id: I0bb7a1daa63298122b51be73d35d695a4f73f8b0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8140
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-04 15:18:37 +00:00
Vincent Ambo
a11a3e2c59 refactor(tvix/eval): implement From<Span> for LightSpan
This simplifies some code down the line.

Change-Id: I58dd71e796e11479f44516cf24932f8061843d23
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8139
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-04 15:18:37 +00:00
Vincent Ambo
344c119370 chore(tvix/eval): fix clippy warnings
Change-Id: I4c02f0104c455ac00a3f299c1fbf75cbb08e8972
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8142
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-03-03 11:01:52 +00:00
Vincent Ambo
7e9a65dcdb refactor(tvix/eval): remove useless map call
Change-Id: Ifb59ef148ea4fab613f2e4efb133c04baafa3a98
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8141
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-03-03 10:57:50 +00:00
Vincent Ambo
fb4c197b39 refactor(tvix/eval): enhance debug output for bytecode dumps
This adds addresses of thunk and closure chunks to the debug output
displayed when dumping bytecode.

This makes it possible to see in the dump which thunks are referenced
by constants in other thunks.

Change-Id: I2c98de5227e7cb415666cd3134c947a56979dc80
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8137
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-03-03 10:52:48 +00:00
Aaqa Ishtyaq
faffb2a4cb refactor(tvix/eval): remove redundant clone
This CL removes redundant clone from value which is
going to be dropped without further use.

Change-Id: Ibd2a724853c5cfbf8ca40bf0b3adf0fab89b9be5
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8125
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-02-16 22:42:14 +00:00
Vincent Ambo
bfe6cace5e docs(tvix/eval): add proposal for VM loop restructuring
Change-Id: Ib991d68724a73886a8343d7f785b5b3aedd637ed
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8103
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2023-02-16 22:23:51 +00:00
Vincent Ambo
3c311ffab2 fix(tvix/eval): correctly print lambda address in observer
We want the address that the Rc is pointing to, not the address of the
Rc.

Change-Id: I8eba21677f242bbe4166c74d4aa4269c316076e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8045
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-02-14 08:02:40 +00:00
Aaqa Ishtyaq
fc61dff037 chore(tvix/eval): use writeln for newline string
This CL address clippy warning which expects to
use `writeln` instead of `write` for strings with
new line.

Change-Id: Ia72a07502c60cfd489ecf1e3833b9d42d44a8b17
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8030
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-02-13 19:45:58 +00:00
Aaqa Ishtyaq
105069302b chore(tvix/eval): clippy warn is length zero
This CL address clippy warning about finding the zero
length of something using `is_empty()` instead of `len() == 0`.

Change-Id: I2b36c7c7b65b733609fc0dcd33be06f9d772bc9b
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8029
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-02-13 19:45:58 +00:00
Vincent Ambo
c98c5399b9 fix(tvix/eval): skip runtime completely on compiler errors
This branch was missing, and an assumption elsewhere just executed the
returned (broken) bytecode.

This fixes b/253.

Change-Id: I015023ba921bc08ea03882167f1f560feca25e50
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8090
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
2023-02-13 16:21:47 +00:00
Vincent Ambo
91a366af46 fix(tvix/eval): make fields of eval's Error type public
These should be inspectable by callers.

Change-Id: Ia9ef871aa63958d06066aaea61b2aecbd217369b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8089
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-13 16:21:46 +00:00
Vincent Ambo
720e80c1f9 fix(tvix/eval): fix the default case for path parsing
Plain paths like `foo/bar.nix` are also allowed, so we can not
determine this based on the prefix.

The upstream PR that is referenced in a comment here has a
significantly different interface than we expected, so I'm not
touching that comment yet in this CL before I've had more time to
digest it.

Change-Id: Iea33bbb35de9c00a7d7fedf64d02253c75c1cc9e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8032
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: Alyssa Ross <hi@alyssa.is>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-02-04 12:44:59 +00:00
Florian Klink
d50044d570 chore(tvix/eval): only use Rc with impure feature
We only use Rc in `impl EvalIO for StdIO`, which is only included when
building with the "impure" feature.

Change-Id: Id29d647c899cbfcdda11abfb9fabd5aa7e24299f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8025
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-02-03 18:58:17 +00:00
Vincent Ambo
f16b0f24e2 refactor(tvix/eval): wrap Builtin type in a Box
This reduces the size of `Builtin` from 88 (!) bytes to 8, and as the
largest variant of `Value`, the size of that type from 96 to 64.

The next largest type is NixList, clocking in at 64 bytes.

This has noticeable performance impact. In an implementation without
disk I/O, evaluating nixpkgs.stdenv looks like this:

Benchmark 1: tvix -E '(import <nixpkgs> {}).stdenv.drvPath'
  Time (mean ± σ):      1.151 s ±  0.003 s    [User: 1.041 s, System: 0.109 s]
  Range (min … max):    1.147 s …  1.155 s    10 runs

After this change, it looks like this:

Benchmark 1: tvix -E '(import <nixpkgs> {}).stdenv.drvPath'
  Time (mean ± σ):      1.046 s ±  0.004 s    [User: 0.954 s, System: 0.092 s]
  Range (min … max):    1.041 s …  1.053 s    10 runs

Change-Id: I5ab7cc02a9a450c0227daf1f1f72966358311ebb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8027
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-03 18:47:33 +00:00
Vincent Ambo
32698766ef refactor(tvix/eval): statically resolve select from constant attrs
When resolving a select expression (`attrs.name` or `attrs.name or
default`), if the set compiles to a constant attribute set (as is most
notably the case with `builtins`) we can backtrack and replace that
attribute set directly with the compiled value.

For something like `builtins.length`, this will directly emit an
`OpConstant` that leaves the `length` builtin on the stack.

Change-Id: I639654e065a06e8cfcbcacb528c6da7ec9e513ee
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7957
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-03 18:47:33 +00:00
Vincent Ambo
3419f63575 fix(tvix/eval): ensure all evaluated thunks are correctly memoized
This fixes a very complicated bug (b/246). Evaluation
progresses *much* further after this, leading to several less
complicated bugs likely being uncovered by this

What was the problem?
=====================

Previously, when evaluating a thunk, we had a code path that looked
like this:

    match *thunk {
        ThunkRepr::Evaluated(Value::Thunk(ref inner_thunk)) => {
            let inner_repr = inner_thunk.0.borrow().clone();
            drop(thunk);
            self.0.replace(inner_repr);
        }
        /* ... */
    }

This code path created a copy of the inner `ThunkRepr` of a nested
thunk, and moved that copy into the `ThunkRepr` of the parent.

The effect of this was that the original `ThunkRepr` (unforced!) lived
on in the original thunk, without the memoization of the subsequent
forcing applying to it.

This had the result that Tvix would repeatedly evaluate these thunks
without ever memoizing them, if they occured repeatedly as shared
inner thunks. Most notably, this would *always* occur when
builtins.import was used.

What's the solution?
====================

I have completely rewritten `Thunk::force_trampoline_self` to make all
flows that can occur in it explicit. I have also removed the outer
loop inside of that function, and resorted to more use of trampolining
instead.

The function is now well-commented and it should be possible to read
it from top-to-bottom and get a general sense of what is going on,
though the trampolining itself (which is implemented in the VM) needs
to be at least partially understood for this.

What's the new problem(s)?
==========================

One new (known) problem is that we have to construct `Error` instances
in all error types here, but we do not have spans available in some
thunk-related situations. Due to b/238 we cannot ask the VM for an
arbitrary span from the callsite leading to the force. This means that
there are now code paths where, under certain conditions, causing an
evaluation error during thunk forcing will panic.

To fix this we will need to investigate and fix b/238, and/or add a
span tracking mechanism to thunks themselves.

What other impacts does this have?
==================================

With this commit, eval of nixpkgs mostly succeeds (things like stdenv
evaluate to the same hashes for us and C++ Nix, meaning we now
construct identical derivations without eval breaking).

Due to this we progress much further into nixpkgs, which lets us
uncover more additional bugs. For example, after this commit we can
quickly see that cl/7949 introduces some kind of behavioural issue and
should not be merged as-is (this was not apparent before).

Additionally, tvix-eval is now seemingly very fast. When doing
performance analysis of a nixpkgs eval, we now mostly see the code
path for shelling out to C++ Nix to add things to the store in there.
We still need those code paths, so we can not (yet) do a performance
analysis beyond that.

Change-Id: I738525bad8bc5ede5d8c737f023b14b8f4160612
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8012
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-03 10:47:18 +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
Vincent Ambo
75d1b72b7c refactor(tvix/eval): import_cache can be a HashMap
... instead of a BTreeMap, as we do not need ordering guarantees here.
HashMaps are noticeably faster here (especially as we've been sorting
essentially random data!).

Change-Id: Ie92d74286df9f763c04c9b226ef1066ee8484c13
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8014
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-02-02 14:25:30 +00:00
Vincent Ambo
98ea614c6e chore(tvix/eval): elaborate on internal types in Value::type_of
This aids in debugging quite substantially.

Change-Id: Ic43232aa6165ae1c3db7ac2701938e1dfeeb418c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8013
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
2023-02-02 09:29:43 +00:00
Vincent Ambo
ddf6e6cf47 fix(tvix/eval): allow builtins.toXML to serialise any function
This adds a fake argument name to builtins.toXML which allows toXML to
serialise any value instead of panicking on functions. We do still
have to fix the value itself, eventually, though.

Change-Id: I2e330ecddcd80442b4fac5eced64431ac86123ba
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7962
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-31 15:31:30 +00:00
Vincent Ambo
7702941dd9 test(tvix/eval): add tests for internal formals dependencies
Formals can depend on each other when using another formal as a
default value.

This test ensures that the compiler's declaration and initialisation
order of formals is consistent with what actually happens in the VM.

Change-Id: Ibdabe262554e8066d67fac1ebc3b5a48ef626e18
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7948
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-31 10:25:02 +00:00
Vincent Ambo
1028aff105 chore(tvix/eval): remove dead comment
Change-Id: Icedb7f272e5067569b8dbf1c2d8b0fdd352b8e12
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7936
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
2023-01-26 23:30:43 +00:00
sterni
8a8325fb9d docs(tvix/eval): builtins.add is not equivalent to +
While it is in the given example, i.e. for integer addition, to claim
that they are equivalent is a bit misleading: builtins.add is less
overloaded than +, i.e. builtins.add "foo" "bar" will fail whereas
"foo" + "bar" performs string concatenation.

Change-Id: Ib52d530d1ab289b367565b286f06a76dd518d4fb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7929
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-25 14:30:50 +00:00
Florian Klink
669496f0ba test(tvix/eval): add test for total_fmt_float
Change-Id: If6c478ee3d2e4ecf5ef92289614f86535ad05cb7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7927
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
2023-01-25 11:24:20 +00:00
Vincent Ambo
164005656d refactor(tvix/eval): extract float formatting into a helper
This keeps the actual TotalDisplay implementation readable, as this
float formatting code suddenly made up the majority of its implementation.

Change-Id: I2c0d00e4a691e0b8ffbc72680f680e16feef4bee
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7925
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-25 11:24:19 +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
Florian Klink
1facd889bb feat(tvix/eval): use lexical-core to format float
Apparently our naive implementation of float formatting, which simply
used {:.5}, and trimmed trailing "0" strings not sufficient.

It wrongly trimmed numbers with zeroes but no decimal point, like
`10000` got trimmed to `1`.

Nix uses `std::to_string` on the double, which according to
https://en.cppreference.com/w/cpp/string/basic_string/to_string
is equivalent to `std::sprintf(buf, "%f", value)`.

https://en.cppreference.com/w/cpp/io/c/fprintf mentions this is treated
like this:

> Precision specifies the exact number of digits to appear after
> the decimal point character. The default precision is 6. In the
> alternative implementation decimal point character is written even if
> no digits follow it. For infinity and not-a-number conversion style
> see notes.

This doesn't seem to be the case though, and Nix uses scientific
notation in some cases.

There's a whole bunch of strategies to determine which is a more compact
notation, and which notation should be used for a given number.
https://github.com/rust-lang/rust/issues/24556 provides some pointers
into various rabbit holes for those interested.

This gist seems to be that currently a different formatting is not
exposed in rust directly, at least not for public consumption.

There is the
[lexical-core](https://github.com/Alexhuszagh/rust-lexical) crate
though, which provides a way to format floats with various strategies
and formats.

Change our implementation of `TotalDisplay` for the `Value::Float` case
to use that. We still need to do some post-processing, because Nix
always adds the sign in scientific notation (and there's no way to
configure lexical-core to do that), and lexical-core in some cases keeps
the trailing zeros.

Even with all that in place, there as a difference in `eval-okay-
fromjson.nix` (from tvix-tests), which I couldn't get to work. I updated
the fixture to a less problematic number.

With this, the testsuite passes again, and does for the upcoming CL
introducing builtins.fromTOML, and enabling the nix testsuite bits for
it, too.

Change-Id: Ie6fba5619e1d9fd7ce669a51594658b029057acc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7922
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-25 07:49:44 +00:00
Vincent Ambo
9ecf668452 chore(tvix/eval): delete "useless parenthesis" warning/optimisation
Two main reasons:

1. Traversing the structure to do this optimisation is
   actually *slower* than not optimising it.

2. There are literally hundreds of thousands of incidences of this in
   nixpkgs, and with some of the weird code there some of
   these (functionally) useless parens are actually required for
   readability reasons.

Change-Id: I1044b1c5f9fe20df4b6085851fc3b191277c65dc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7917
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-23 17:59:06 +00:00
Vincent Ambo
d2f1a290a4 fix(tvix/eval): force functors before applying them
call_value in the VM expects the callable to be forced when calling
it, which was not the case for functors.

Change-Id: Id55a2fe32a9573be42aef8669e268df519a989cd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7909
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-01-23 17:27:53 +00:00
Vincent Ambo
5719763fd3 feat(tvix/eval): support builtins implemented in Nix itself
This makes it possible to inject builtins into the builtin set that
are written in Nix code, and which at runtime are represented by a
thunk that will compile them the first time they are used.

Change-Id: Ia632367328f66fb2f26cb64ae464f8f3dc9c6d30
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7891
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-22 20:48:53 +00:00
Vincent Ambo
8513a58b37 docs(tvix/eval): update some outdated comments
These don't apply anymore since the "antidote-CL".

Change-Id: I40ee73ef43d44bbfc650a8fe6c2b33263dd06959
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7890
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-22 19:39:00 +00:00
Florian Klink
758b94f47c docs(tvix): move most of //tvix/eval README up to //tvix
While moving the CLI out of the evaluator, we forgot to update the
README in //tvix/eval. Move this up to //tvix, so people know where
to start.

Keep the instructions on how to build only `//tvix/eval` in `//tvix/
eval/README.md`.

Change-Id: Ie2755e8b5a0056225dbf3a0ee040f70f7f6a1f27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7887
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-21 15:08:38 +00:00
Adam Joseph
22b9e6ff09 refactor(tvix/eval): administer antidote for poison
The codebase contains a lot of complexity and odd roundabout
handling for shadowing globals.  I'm pretty sure none of this is
necessary, and all of it disappears if you simply make the globals
part of the ordinary identifier resolution chain, with their own
scope up above the root scope.  Then the ordinary shadowing routines
do the right thing, and no special cases or new terminology are
required.

This commit does that.

Note by tazjin: This commit was originally abandoned when Adam decided
not to take away reviewer bandwidth for this at the time (eval was
still in a much earlier stage). As we've recently done some
significant refactoring of globals initialisation this came up again,
and it seems we can easily cover the use-cases of the poison tracking
in other ways now, so I've rebased, updated and resurrected the CL.

Co-Authored-By: Vincent Ambo <tazjin@tvl.su>
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: Ib3309a47a7b31fa5bf10466bade0d876b76ae462
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7089
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-21 10:19:15 +00:00
Vincent Ambo
7442558b33 refactor(tvix/eval): keep globals alive through VM struct
This forces users to pass the fully constructed set of globals to the
VM, making it harder to accidentally "lose" the set while weak
references to it still exist.

This doesn't modify any functionality, but is laying the foundation
for simplifying some of the builtins behaviour that has grown more
complex again.

Change-Id: I5120f97861c65dc46d90b8a4e2c92ad32cc53e03
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7877
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-20 22:48:13 +00:00
Vincent Ambo
6d03e31060 docs(tvix/eval): add doc comments to VM fields
Change-Id: Ia4857c217de15aec8b61e1abd39e22c50e2d816a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7876
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
2023-01-20 22:48:13 +00:00
Vincent Ambo
7d0456fa0e feat(tvix/eval): let builtin macro capture external state
This adds a feature to the `#[builtins]` macro which lets users
specify an additional state type to (optionally) thread through to
builtins when constructing them.

This makes it possible for builtins-macro users to pass external state
handles (specifically, in our case, known path tracking) into a set of
builtins.

Change-Id: I3ade20d333fc3ba90a80822cdfa5f87a9cfada75
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7840
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-20 15:39:51 +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
972c867b36 feat(tvix/eval): add error contexts to annotate error kinds
This makes it possible for users to add additional context to an
error, which will then be rendered as an additional secondary span in
the formatted error output.

We should strive to do this basically anywhere errors are raised that
can occur multiple times, *especially* during type casts. This was
triggered by me debugging a type cast error attached to a fairly
large-ish span (a builtin invocation).

Change-Id: I51be41fabee00cf04de973935daf34fe6424e76f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7849
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-20 15:39:51 +00:00
Vincent Ambo
bf6f6a0b3f refactor(tvix/eval): non-hacky suspended native thunks
Instead of having a representation of suspended native thunks that
involves constructing a fake code chunk, make these thunks a
first-class part of the internal thunk representation.

The previous code was not that simple to understand, and actually
contained a critical bug which could lead to Tvix crashes. This
version fixes the particular instance of that bug, but instead
uncovers another (b/238) which can still lead to Tvix crashes.

Fixes: b/237.
Change-Id: I771d03864084d63953bdbb518fec94487481f839
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7750
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-17 10:38:06 +00:00
Vincent Ambo
559a09c5e6 refactor(tvix/eval): remove Box in new_suspended_native
This is unnecessary, Rc already provides all the boxing we need.

Change-Id: I08cf0939c48da43f04c847526c7e5dae5336d528
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7749
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-01-17 10:38:06 +00:00
Vincent Ambo
b9646ab40c feat(tvix/eval): add builtins to builtins
This is a somewhat terrifying hack that enables us to support
`builtins.builtins`, by running a "fake compilation" inside of a
suspended native thunk that can resolve the weak pointer to the
globals.

With this implementation, the thunk at `builtins.builtins` actually
resolves to the "real" `builtins` (verified with a new test).

This is kind of ugly, and it's something users shouldn't use, but
bubbling a warning out of this is difficult at the moment due to a
little bit of trickery with how the spans in suspended native thunks
work (they don't) (see b/237, b/238)

Change-Id: I67d0e93246dd5b279c960aeda00402031aa12af3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7748
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-17 10:38:06 +00:00
Vincent Ambo
940251b87f refactor(tvix/value): use proptest strategies from imbl crate
Instead of going through Vec/BTreeMap for generating our internal
types, use the proptest strategies from imbl.

The one thing I couldn't figure out in the previous implementation is
where the ranges/sizes of generated collections came from. The
strategies in proptest use different types (Range, with an unknown
default value, and SizeRange with 0..100). I've opted to specify
0..100 directly, but we can probably make it configurable.

Change-Id: I749bc4c703fe424099240cab822b1642e5216361
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7791
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-17 10:20:38 +00:00
Vincent Ambo
67addf3b3d feat(tvix/eval): add error variant for threading through errors
This variant is required for external builtins (which in our case
includes `derivation`) to thread through reasonable error messages.

This has some potential for improvement, but it's an improvement over
the status quo of panicking in the external builtins when no
appropriate error is available.

Change-Id: I7e4bdb0a156c7717092dde30aa4785192182dc66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7841
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-16 13:43:14 +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
Vincent Ambo
1786b4c835 chore(tvix/eval): add other required items to public API
External implementors of builtins must be able to force values, which
necessitates publishing a bunch more items from the crate.

Change-Id: I8f6b8ae88156aae417dbe630a698d123d0c1c8d4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7830
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
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
09654ffb80 docs(tvix): add build-references / string-context document
This explains my current thinking on string contexts. Thanks to
everyone who gave input so far.

Change-Id: I773219402a79a9d4753b4e7cfbf3a4a751a993a3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7807
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-12 11:01:40 +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
Aaqa Ishtyaq
9382afdb0d fix(tvix/eval): address useless_format clippy warn
This CL address clippy warnings related to use of 'format!' macro
to return unmodified 'String'.

Change-Id: I88726e59d8f39f6a455a8c1f48075b52d167e489
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7804
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-10 19:13:45 +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
c011a6130c refactor(tvix/eval): impl Display for ErrorKind
This just shuffles the Display implementations around so that
ErrorKind itself is displayable, which is useful in some situations
where errors under construction need to be type-converted.

Change-Id: I7b633d03d0dc34f345c4f20676e0023ecb1db0c4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7802
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: edef <edef@edef.eu>
Tested-by: BuildkiteCI
2023-01-10 09:52:52 +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
a149a1ee06 fix(tvix/eval): fix typo'd function name in tests
Caught by sterni on cl/7783.

Change-Id: I15d57b893ef22538fdd7e809f3b92861dd2bc1af
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7789
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-07 14:48:42 +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
Vincent Ambo
87c80895cd feat(tvix/eval): skip & warn for useless parenthesis
Change-Id: I567ca0682012b9d09f1217e57a104ac5671f8d82
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7771
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: flokli <flokli@flokli.de>
2023-01-06 12:23:55 +00:00
Vincent Ambo
aadf71a6ed feat(tvix/eval): warn on empty let-bindings
Change-Id: Ib6ef7ce514abbd3e372dfe9df7137aa36dbda9d4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7770
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-06 12:23:55 +00:00
Vincent Ambo
61b8a9b2ba refactor(tvix/eval): short-circuit on empty attrs in compiler
This is marginally more efficient and has simpler bytecode.

Change-Id: Iad37c9aeef24583e8f696911bcd83d43639f2e36
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7769
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-06 12:23:55 +00:00
Vincent Ambo
4e98730f38 feat(tvix/eval): warn about empty inherits
Change-Id: I82bec6fe2210bcb88c46fd2fdf3e26bd613d1c1f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7768
Reviewed-by: flokli <flokli@flokli.de>
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-01-06 12:23:55 +00:00
Vincent Ambo
e8dcdceb34 fix(tvix/eval): compile but don't emit dead code
This adds a mechanism to the compiler to compile an expression without
emitting any code. This allows for detected dead code to still be
compiled to detect errors & warnings inside of it.

Change-Id: Ie78479173570e9c819d8f32ae683ce34234a4c5d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7767
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-06 12:23:55 +00:00
Vincent Ambo
6a8541e35a feat(tvix/eval): implement initial compiler::optimiser module
This optimiser can rewrite some expressions into more efficient forms,
and warn users about those cases.

As a proof-of-concept, only some simple boolean comparisons are
supported for now.

Change-Id: I7df561118cfbad281fc99523e859bc66e7a1adcb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7766
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-06 12:23:55 +00:00
Vincent Ambo
36e5a4cc07 refactor(tvix/eval): take owned ast::Expr in Compiler::compile
This adds a very minimal amount of additional Rc-increments (~1 per
compilation), but makes it a lot easier to add an AST-optimising
compiler pass without incurring a lot of extra cost.

Change-Id: I57208bdfc8882e3ae21c5850e14aa380d3ccea36
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7765
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-06 12:23:55 +00:00
Vincent Ambo
5926a05f46 feat(tvix/eval): add Evaluation::compile_only method
This would make it possible to implement something like a linter based
on the tvix-eval compiler warnings.

Change-Id: I1feb4e7c4a44be7d1204b0a962ab522fd32b93c6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7763
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-06 12:23:55 +00:00
Vincent Ambo
27fecee1bc fix(tvix/eval): don't increase with_stack_size in scope inherits
There was probably a misunderstanding somewhere about the
with_stack_size being related to how far away it is from the with, but
it is about whether there is a with at all.

This broke a warning (`UselessInherit`), and may actually have let to
more inefficient codegen in some cases.

Change-Id: I08338ea59ae39dad01ca8a4e09d934a936cdea2f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7762
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-06 12:23:55 +00:00
Vincent Ambo
88432235ae fix(tvix/eval): VM & Builtin* types have to be public
... without them, using the new Builtins API is basically impossible
for library consumers.

Change-Id: Ice0557a2e55e12d812f51bf5a99e6b8c91ad1b91
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7755
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-06 12:15:23 +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
sterni
b7090ec874 test(tvix/eval): add test for builtins parity
This will eventually force us to have a base builtins set in common with
C++ Nix, i.e. all 2.3 builtins except the controversial
builtins.valueSize.

Change-Id: I2c767f07d6a14711911658e87da9f18ede57a143
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7747
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-06 12:00:38 +00:00
Vincent Ambo
34be6466d4 feat(tvix/serde): implement enum deserialisation
Implements externally tagged enum deserialisation. Other serialisation
methods are handled by serde internally using the existing methods.

See the tests for examples.

Change-Id: Ic4a9da3b5a32ddbb5918b1512e70c3ac5ce64f04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7721
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
2023-01-04 17:21:40 +00:00
Vincent Ambo
0c17718dd1 refactor(tvix/eval): avoid unnecessary pop/push in OpForce
Change-Id: Ic7559eaa43aa0dcc97babb7669770c0f7f959f1b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7754
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-01-04 16:30:03 +00:00
sterni
9b8ba915c8 fix(tvix/eval): ' is allowed in nonfirst position in Nix identifiers
With this is_valid_nix_identifier should line up with the upstream lexer
definition:

    ID          [a-zA-Z\_][a-zA-Z0-9\_\'\-]*

While we're working on this, add a simple test checking the various
formatting rules. Interestingly, it would not be suitable as an identity
test, since you have to write

    { "assert" = null; }

in order to avoid an evaluation error, but C++ Nix is happy to print
this as

    { assert = null; }

– maybe should be considered to be a bug.

Change-Id: I0a4e1ccb5033a80f3767fb8d1c4bba08d303c5d8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7744
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-04 12:36:28 +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
49ee3e3b14 chore(tvix/eval): implement std::error::Error for tvix_eval::Error
This makes it easier to interface this error with other crates.

Change-Id: I4947ea6097608f8c0427fb94a819ef748d94ea4b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7711
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-02 22:24:43 +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
sterni
56555b211e docs(tvix/eval): sketch in place list/attr set update idea
Change-Id: Ic7debbd8cbd3acdf5f3947288f2aa2964bd163a0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7660
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-12-29 09:52:17 +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
67d508f2ec refactor(tvix/eval): non-recursive thunk forcing
Introduces continuation-passing-based trampolining of thunk forcing to
avoid recursing when forcing deeply nested expressions.

This is required for evaluating large expressions.

This change was extracted out of cl/7362.

Co-authored-by: Vincent Ambo <tazjin@tvl.su>
Co-authored-by: Griffin Smith <grfn@gws.fyi>
Change-Id: Ifc1747e712663684b2fff53095de62b8459a47f3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7551
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-12-25 18:17:46 +00:00
Ryan Lahfa
4cda236c0c feat(tvix/eval): implement From<f64> for Value
Change-Id: I287282a195d6f752260242739332b2357791974a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7625
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-12-25 15:47:40 +00:00
Vincent Ambo
712f1167ad feat(tvix/eval): display function names in documentation
... if they are known. We currently do not propagate names correctly
for curried functions.

Change-Id: I19d57fb30a5c0000ccdf690b91076f6b2191de23
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7596
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-22 19:09:40 +00:00
Vincent Ambo
e306d1d1a1 feat(tvix/eval): add Value::explain method
This value creates a human-readable explanation of a value. This can
be used to implement documentation related functionality.

For some values, the amount of information displayed can be expanded
quite a bit.

Change-Id: Ie8c400feae909e7680af163596f99060262e4241
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7592
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-22 19:09:40 +00:00
Vincent Ambo
ea7d63e177 feat(tvix/cli): implement NixCompatIO helper type
This type allows for temporarily compatibility with the C++ Nix store,
specifically (for now) it gives us the store directory used by Nix and
imports files the same way.

Change-Id: I4767794ef2863eba49661315c63c4e17de946d60
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7587
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-22 19:09:40 +00:00
Vincent Ambo
22ed59fabd chore(tvix/eval): fix a broken comment
Change-Id: I0a6edb51685f94d4712089ae805170da3fb7faae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7609
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-21 23:29:26 +00:00
Vincent Ambo
908cebf35c fix(tvix/builtin-macros): parse multi-line docstrings correctly
Having a multi-line docstring yields multiple doc-attributes in order,
however we were previously discarding all but the first one.

This reduces them into a single string instead, which can then be
displayed as multi-line documentation.

Change-Id: I1f237956cdea2e4c746d3f13744e0373c1c645a6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7594
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-21 23:05:22 +00:00
Vincent Ambo
270b1084e8 feat(tvix/eval): use EvalIO::import_path when coercing paths
This "ties the knot" of importing files into a store when referring
to them through path literals, e.g. inside of strings.

I'm not yet sure if this interface is sufficient for
builtins.path (which we haven't implemented at all yet), but it's
enough to wire up eval & store initially.

In the default implementations nothing interesting happens in this
function at all.

Change-Id: Ie01ff4161617d1e743a68dbd1a5e54c1b40c0990
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7582
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 22:59:18 +00:00
Vincent Ambo
edd13573f5 refactor(tvix/eval): use light spans in builtins.import
Change-Id: I05732073155b430575babb6f076bf465aef98857
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7581
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 22:59:18 +00:00
Adam Joseph
947a56c4b6 feat(tvix/eval): builtins.storeDir
Returns the store directory through EvalIO::store_dir.

Note that this is _optional_ in Tvix, as an evaluation can occur in a
context where there simply is no store directory. In those contexts,
`builtins.storeDir` returns `null` in Tvix.

This would only happen in contexts like Tvixbolt (or completely
unrelated use-cases) in practice.

Co-Authored-By: Vincent Ambo <tazjin@tvl.su>
Change-Id: I5a752c7e89b2f75bd7efb082dbfa5b25e3b1ff3b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7452
Autosubmit: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 22:59:18 +00:00
Vincent Ambo
4cb9ada0df refactor(tvix/eval): use EvalIO::read_dir for equivalent builtin
Change-Id: I6d782c07166f51587d2f1d06607823268debb5d5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7574
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 22:59:18 +00:00
Vincent Ambo
51deadd983 refactor(tvix/eval): use EvalIO::path_exists for the builtin
Change-Id: I49822ce30137777865e7370ee86666636e277b35
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7573
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 22:53:02 +00:00
Vincent Ambo
ec3e38c2d6 chore(tvix/eval): gate tvix_eval::StdIO behind the impure feature
This shouldn't be available if we've built a "pure" crate.

Change-Id: I7c85827ee212890252ff7e0b6242e2c52618cba5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7572
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 22:53:02 +00:00
Vincent Ambo
0ef3c2fc2b refactor(tvix/eval): use EvalIO::read_to_string in impure builtins
With this change, the behaviour of reading a string from a file path
is controlled by the provided `EvalIO` structure.

This is a huge step towards abstracting away I/O behaviour correctly.

Change-Id: Ifde8e46cd863b16e0301dca45a434ad27560399f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7567
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 22:37:11 +00:00
Vincent Ambo
c3c4d752c9 feat(tvix/eval): add EvalIO to public crate API
This lets users set the `io_handle` field on an `Evaluation`, which is
then propagated to the VM.

Change-Id: I616d7140724fb2b4db47c2ebf95451d5303a487a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7566
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 22:37:11 +00:00
Vincent Ambo
25fc6b7c25 feat(tvix/eval): introduce initial EvalIO trait
This trait is going to be used to abstract filesystem interactions in
Tvix.

For now, it only contains a `read_to_string` method that closely
mirrors `std::fs::read_to_string`.

As a first step, to see how this works in practice, we will thread
through only this function to the various relevant parts.

Two implementations are provided in tvix-eval itself: A dummy
implementation (which just returns ErrorKind::NotImplemented for all
operations), and a std implementation which delegates to `std`
functions.

Change-Id: Ied3e3bf4bd0e874dd84e166190e3873a0f923ddb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7565
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 22:37:11 +00:00
Vincent Ambo
bf286a54bc refactor(tvix/eval): add a LightSpan type for lighter span tracking
This type carries the information required for calculating a
span (i.e. the chunk and offset), instead of the span itself. The span
is then only calculated in cases where it is required (when throwing
errors).

This reduces the eval time for
`builtins.length (builtins.attrNames (import <nixpkgs> {}))` by *one
third*!

The data structure in chunks that carries span information reduces
in-memory size by trading off the speed of retrieving span
information. This is because the span information is only actually
required when throwing errors (or emitting warnings).

However, somewhere along the way we grew a dependency on carrying span
information in thunks (for correctly reporting error chains). Hitting
the code paths for span retrieval was expensive, and carrying the
spans in a different way would still be less cache-efficient. This
change is the best tradeoff I could come up with.

Refs: b/229.
Change-Id: I27d4c4b5c5f9be90ac47f2db61941e123a78a77b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7558
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 22:21:25 +00:00
Adam Joseph
da7c331d2c feat(tvix/eval): add thunks with suspended native Rust code
Having thunks which, when forced, execute native Rust code rather
than interpreted opcodes lets us avoid having to bundle
`src/libexpr/primops/derivation.nix` like cppnix does by implementing
it in Rust instead.

Change-Id: If91d77a6736234321eee87ba4b4777eed5a3fe1c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7450
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 21:48:08 +00:00
Vincent Ambo
87995ed355 refactor(tvix/eval): add name-based index over compiler's locals
Instead of finding locals by doing 2x O(n) walks over the compiler's
locals list, use a secondary name-based index for resolving locals by
name.

Previously, almost 60% (!!) of eval time on some expressions over
nixpkgs was spent in `Local::has_name`. This function doesn't even
exist anymore now, and eval speed about doubles as a result.

Note that this doesn't exactly make the locals code easier to read,
but I'm also not sure what we can simplify in there in general.

This fixes b/227.

Change-Id: I29ce5eb9452b02d3b358c673e1f5cf8082e2fef9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7560
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 21:48:08 +00:00
Adam Joseph
922bf7aca9 feat(tvix/eval): remove derive(Copy) from Upvalues
Change-Id: I0fa069fbeff6718a765ece948c2c1bce285496f7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7449
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 14:50:04 +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
Vincent Ambo
6d3d237923 refactor(tvix/eval): consume self in Evaluation::evaluate
This simplifies lifetime management for observers in callers of tvix_eval.

Change-Id: I2f47c8d89f22b1c766526e5d1483c0d026b500ae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7546
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 13:23:38 +00:00
Vincent Ambo
59e695a9d9 feat(tvix/eval): add observer configuration to public API
With this change, it should be possible to have both existing
use-cases (CLI & Tvixbolt) use the same API.

Change-Id: I2195264f08cc892177b559a28660dc5f98e48e41
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7545
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 13:23:38 +00:00
Vincent Ambo
9bc1e6ef05 feat(tvix/eval): add configuration of Nix search path to public API
This is required for passing through NIX_PATH from the CLI.

Change-Id: If129df79ef9c3ffab31408adb85679909276c4f0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7544
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-21 13:23:38 +00:00
Vincent Ambo
9d6ee5b6a6 fix(tvix/eval): use test-generator fork that supports workspaces
This should make no difference in Nix builds, but allows running tests
locally again with `cargo test` for //tvix/eval.

Change-Id: I97d61840143d5c14db61d5862781bf635f9a28e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7590
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2022-12-21 13:23:38 +00:00
Vincent Ambo
257c67f204 chore(tvix): upgrade to clap 4.0
In //tvix/eval:

* criterion bumped to 4.0, which at least depends on clap 3.x instead
  of 2.x, which is less incompatible

In //tvix/cli:

* no changes required

In //tvix/nix_cli:

* some minor changes for compatibility with clap 4.0, no functionality
  changes

Change-Id: If793f64b59fcaa2402d3d483ddbab4092f32df03
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7588
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 13:23:38 +00:00
Vincent Ambo
d9e2bec953 refactor(tvix): split binary (REPL etc.) out from evaluator library
The tvix-eval project is independent from any *uses* of the evaluator,
such as the tvix-repl.

This functionality has been split out into a separate "tvix-cli"
crate. Note that this doesn't have to mean that this CLI crate is the
"final" CLI crate for tvix, the point of this is not "getting the CLI
structure right" but rather "getting the evaluator structure right".

This reshuffling is part of restructuring the way that functionality
like store communication is injected into language evaluation.

Note that at this commit the new CLI crate is not at feature-parity.

Change-Id: Id0af03dc8e07ef09a9f882a89612ad555eca8f93
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7541
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 13:09:29 +00:00
Vincent Ambo
1138fbcaad refactor(tvix/eval): use new public API in test code
This removes internal uses of the previous crate::eval module, which
is being removed.

Change-Id: I5fb3c53460a9c5381853d0258f9ed074ab23c630
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7543
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 13:09:28 +00:00
Vincent Ambo
d101151fc5 feat(tvix/eval): begin introducing new public API
A step towards something more like how I imagine the future public API
for tvix-eval. Please note that this is definitely not the final
version yet, but it's better than the previous API that either exposed
a side-effecting blackbox, or a very low-level "interface".

The basic idea is that an evaluation of some Nix code is requested by
a caller with various parameters, but not all callers are interested
in all of these parameters.

There are also some bits of information that are returned from an
evaluation that are not necessarily relevant to all callers.

To support this somewhat ergonomically, the API is built around an
`Evaluation` struct that is configured by the caller with the various
parameters and then "executed".

Change-Id: I71826f3897126898adc2873d31c44d3eaf5c2be0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7542
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-21 13:09:27 +00:00
Vincent Ambo
3aca3d3bba refactor(tvix): build Rust projects using crate2nix
Introduces granular dependency builds using crate2nix, bootstrapped
off the generated configuration from the newly introduced
workspace (see cl/7533).

This commit checks in the generated Cargo.nix file which can be
regenerated with a parameterless invocation of `crate2nix generate` in
`//tvix`. I tried generating this in IFD, but it turned out to be
harder than what seemed worthwhile for now.

In this setup, the various build targets for Rust projects end up
being attributes of the imported `Cargo.nix` file at the `tvix.crates`
attribute. These still lack configuration, however, which has been
fixed in the various `default.nix` files of individual projects.

Note that we (temporarily) lose the ability to build tvix-eval's
benchmarks in CI. I haven't figured out what magic incantation summons
them from the void again ...

The `eval-okay-readDir` tests from both test suites have been disabled
because they fail for unknown reasons when run in this new derivation.
Somebody will have to debug it!

Change-Id: I2014614ccb9c8951aedbd71df7966ca191a13695
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7538
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2022-12-15 17:26:45 +00:00
Vincent Ambo
d9d627cdf0 refactor(tvix): share a Cargo.lock file between Rust projects
This relates to the (abandoned) cl/7256.

Introduces a Cargo workspace at //tvix that is primarily intended to
be used as a workaround for the annoying Nix+Rust tooling while having
a consistent set of dependencies.

This is driven in part by a desire to adopt crate2nix and get more
granular Nix builds for Tvix's Rust projects, and in part by a need to
split //tvix/eval into something providing the CLI (REPL etc.), and a
library providing eval, without significantly altering the structure
of build targets.

To accomplish this the workspace has been designed to allow projects
to remain independent build targets. I want to avoid lumping all the
projects together - something like //tvix/eval should always be
independent of other parts of tvix.

A helper function in //tvix/default.nix lets downstream naersk
projects construct a sparse root for the project which combines the
workspace's `Cargo.lock` with the project's own `Cargo.toml`.

Note that cargo commands in the workspace itself require the build
dependencies of _all_ projects to be present, which is currently a bit
annoying to accomplish.

This introduces some breakage:

1. It breaks usage of rust-analyser without being in a shell with the
   dependencies of *all* Tvix projects, as it is not capable of
   respecting only the subset of dependencies for a part of the
   workspace.

2. It is no longer possible to run tests using `cargo test`, as the
   test generation crate we use does not work with workspaces:

   https://github.com/frehberg/test-generator/issues/6

   This still works in the Nix build as we construct a Cargo project
   that looks like it's not in a workspace there. Until somebody fixes
   that crate / writes a new macro / does something else with the test
   suite, the way to run the tests is through the Nix build.

Long-term we'll probably want to get rid of cargo completely, it's
just a big wart and most tooling works without it if correctly
configured, but we don't have time for that now.

Change-Id: I846bff7a8429a25c077fd1e9ef4e3c34a299a4a1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7533
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-15 17:26:45 +00:00
Vincent Ambo
f282984c25 fix(tvix/eval): use rnix-parser from crates.io
A few weeks ago, oberblastmeister did a release to crates.io so we can
stop importing it via GitHub.

Change-Id: I9d5fa5cd281685779c71b12fed45ed201a1db17e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7532
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-12-06 18:29:50 +00:00