Commit graph

558 commits

Author SHA1 Message Date
Griffin Smith
ba8ec1910b feat(tvix/eval): Implement builtins.foldl'
Change-Id: Ibc97db4343cb3a1a1677f69fb6c3518c61978aad
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6906
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 15:26:29 +00:00
Griffin Smith
0e97555644 feat(tvix/eval): Implement builtins.genList
Change-Id: Iabe28656229f508226b244d81382e517961eb3cf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6901
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-10 13:54:16 +00:00
Griffin Smith
b6089fb1e5 feat(tvix/eval): Implement builtins.concatMap
Change-Id: I08bfd040a242aa43b64760c19f48a28303f206ac
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6900
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-10 13:54:16 +00:00
Griffin Smith
afdf1e0ed0 feat(tvix/eval): Implement builtins.listToAttrs
Implement the listToAttrs builtin, which constructs an attribute set
from a list of attribute sets with keys name and value.

This is tested using an adaptation of the nix `eval-ok-listtoattrs.nix`,
with the utilities from `lib.nix` inlined.

Change-Id: Ib5bf743466dda9722c2c1e00797df4b58448cf0f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6894
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-09 22:18:53 +00:00
Griffin Smith
d0f571dcc0 refactor(tvix/eval): Use Display impl for Error message
This is generally more idiomatic (over just delegating to Debug), and
also allows us to avoid intermediate allocations if we ever end up
using error messages as part of larger strings (because we don't have to
allocate a full String for the return value).

Change-Id: I67e48b44570c72761ed0fcaded9ae4bf3fcbaacf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6896
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-09 17:12:41 +00:00
Griffin Smith
1e85209809 feat(tvix/eval): Handle invoking binary with a directory
Similar to what we do for import, push on a `default.nix` to the path
that the top-level is invoked with (if any) if it's a directory.

Change-Id: I281bd44e3c8803b6765c886ae5fd08f549e2e563
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6895
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-08 19:16:10 +00:00
Vincent Ambo
207f3dd47e fix(tvix/eval): end scope after compiling legacy let bindings
When contrasting the compilation of the desugared version to the
"sugared" version, this was the noticeable difference.

This fixes b/203.

Change-Id: Iae02ffc56e06de1de091b84cdc59d8fe83a17d69
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6898
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-08 19:10:09 +00:00
Griffin Smith
b4d978cd6a feat(tvix/tests): Import default.nix inside directory
This requires actually passing the source directory into `interpret` in
the eval tests, but otherwise this is fairly straightforward - if we're
trying to import a directory, just push `default.nix` onto it and import
that instead.

Change-Id: I0b7d4234f81977e78d14dfa651bf0cf9721017e5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6893
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-08 19:02:25 +00:00
Griffin Smith
278bccc1ea refactor(tvix/eval): Encapsulate Value::Attrs construction
Factor out the construction of Value::Attrs (including the Rc) into a
new `attrs` constructor function, to abstract away the presence of the
Rc itself.

Change-Id: I42fd4c3841e1db368db999ddd651277ff995f025
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6892
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-08 19:02:25 +00:00
Griffin Smith
f6bcd11cad fix(tvix/eval): Force thunks when comparing against ground vals
Thunks correctly force when comparing for equality against other thunks,
but weren't being forced correctly when comparing against non-thunk
values, in either direction.

Change-Id: Ia03702895ec4d70aed3445c1b0a9a7a641d1a300
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6897
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-08 19:02:25 +00:00
Vincent Ambo
1677186144 feat(tvix/eval): add some slightly more descriptive span labels
Change-Id: I530c491f60a33fdb97e1553b193de51e7ee57d9a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6873
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-08 17:27:57 +00:00
Vincent Ambo
9b1a266197 feat(tvix/eval): chain error spans for thunk errors
Adds secondary spans for errors that occur deeply nested within a
thunk.

This is pretty raw right now, there's technically nothing stopping one
of these error chains from being a hundred thunks deep into code,
producing unmanageable error output. We should trim these down
according to some heuristics (e.g. when crossing file boundaries, o r
just - for starters - beginning and end).

Change-Id: Ia73892512737850b6fa3e07cabc37fa9c534c4d5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6872
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-08 17:27:57 +00:00
Vincent Ambo
1e2d323a7c feat(tvix/eval): fancy-format parse errors returned by rnix
This change is quite verbose, so a little bit of explaining:

1. To correctly format parse errors, errors must be able to return
   more than one annotated span (the parser returns a list of errors
   for each span).

   To accomplish this, the structure of how the `Diagnostic` struct
   which formats an error is constructed has changed to delegate the
   creation of the `SpanLabel` vector to the kind of error.

2. The rnix structures don't have human-readable output formats by
   default, so some verbose methods for formatting them in
   human-readable ways have been added in the errors module. We might
   want to move these out into a submodule.

3. In many cases, the errors returned by rnix are a bit strange - so
   while we format them with all information that is easily available
   they may look weird or not necessarily help users. Consider this CL
   only a first step in the right direction.

Change-Id: Ie7dd74751af9e7ecb35d751f8b087aae5ae6e2e8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6871
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-08 17:27:57 +00:00
Vincent Ambo
70113407d2 refactor(tvix/eval): implement ToSpan directly for rnix::TextRange
This logic was duplicated between the two rnix types before, but more
crucially - it is also needed for correctly displaying the text ranges
contained in syntax errors.

Change-Id: Ifc6a521de1594d6ced9cba6274f1931df99b6634
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6870
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-08 10:58:42 +00:00
Vincent Ambo
50baf0bcfc refactor(tvix/eval): move spans module to crate root
This is also useful for error-handling related logic, outside of just
the compiler module.

Change-Id: I5c386e2b4c31cda0a0209b31136ca07f00e39e45
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6869
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-08 10:58:42 +00:00
Vincent Ambo
2478a6c5ba feat(tvix/eval): coerce values to paths when importing
This enables the use of string paths (and, in the future,
derivations), as long as their string values represent an absolute
path.

Change-Id: I4b198efeb70415ed52f58bd1da6fa79a24dad14c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6866
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-07 14:24:36 +00:00
Vincent Ambo
07e03498f2 feat(tvix/eval): add method for emitting runtime warnings
This lets the VM emit warnings when it encounters situations that
should only be warned about at runtime.

For starters, this is used to pass through compilation warnings that
come up when `import` is used.

Change-Id: I0c4bc8c534d699999887c430d93629fadfa662c4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6868
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-07 14:24:36 +00:00
Vincent Ambo
4b9178fa2a feat(tvix/eval): insert import into the builtins itself
Adding `import` to builtins causes causes a bootstrap cycle because
the `import` builtin needs to be initialised with the set of globals
before being inserted into the globals, which also must contain
itself.

To break out of the cycle this hack wraps the builtins passed to the
compiler in an `Rc` (probably sensible anyways, as they will end up
getting cloned a bunch), containing a RefCell which gives us mutable
access to the builtins.

This opens up a potentially dangerous footgun in which we could mutate
the builtins at runtime leading to different compiler invocations
seeing different builtins, so it'd be nice to have some kind of
"finalised" status for them or some such, but I'm not sure how to
represent that atm.

Change-Id: I25f8d4d2a7e8472d401c8ba2f4bbf9d86ab2abcb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6867
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-07 14:24:36 +00:00
Vincent Ambo
b530e496a5 feat(tvix/eval): initial implementation of builtins.import
This adds an initial working version of builtins.import which
encapsulates the entire functionality of `import` within the builtin
itself, without requiring any changes in the compiler or VM.

The key insight that enables this is that we can simply return a Thunk
from `import` that is constructed from the output of running the
compiler and - ta-da! - no other component needs to know about it.

A couple of notes:

* builtins.import needs to capture variables like the SourceCode
  structure. This means it can not currently be constructed the same
  way as other builtins and has special handling, which leaks out to
  `eval.rs`. I have postponed dealing with that until we have this
  working a bit more.

* the `globals` are not yet passed through

* the error representation for the new variants is absolutely not done
  yet, we probably want to switch to something that supports
  cause-chaining now (like miette)

* there is no mechanism for emitting warnings at runtime; we need to
  add that

Change-Id: I3117a7ae3ff2432bf44f5ff05ad35f47faca31d5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6857
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-06 15:22:32 +00:00
Vincent Ambo
44acffc688 refactor(tvix/eval): builtins now contain closures
For some upcoming builtins (notably, import) we need to capture
arguments in the builtin's implementation.

To allow this, we can no longer use function pointers for builtins,
but must use a reference-counted closure object instead.

Unfortunately this adds an extra pointer operation to every builtin
call. We should benchmark this later against having a split builtin
representation.

Change-Id: I109d98d0e25998870542f47573eb1ec2e546f2a2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6856
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-06 15:22:32 +00:00
Vincent Ambo
7fe1331570 feat(tvix/eval): implement tvix's user-agent, err, nixVersion
nixpkgs has hardcoded references to Nix versions, we need to provide
it with something that looks like a Nix version while actually being a
Tvix version.

For now, we do this by stealing a trick out of the browser book and
constructing a version that looks like a Nix version to Nix, but like
a Tvix version to people who know what they are looking for.

Nevermind that we don't actually have any kind of versioning for
Tvix (yet?), other than depot revisions.

Change-Id: I7ce8079dd8164a2079891d38e707f09a45f0bbc1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6858
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-05 13:07:55 +00:00
Vincent Ambo
3530404a4a refactor(tvix/eval): introduce source::SourceCode type
This type hides away the lower-level handling of most codemap data
structures, especially to library consumers (see corresponding changes
in tvixbolt).

This will help with implement `import` by giving us central control
over how the codemap works.

Change-Id: Ifcea36776879725871b30c518aeb96ab5fda035a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6855
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
2022-10-05 10:29:47 +00:00
Vincent Ambo
2ff764ceb7 refactor(tvix/eval): remove unnecessary clones in compiler
There's basically nothing that needs *ownership* of an AST
node (which is just a little box full of references to other things
anyways), so we can thread this through as references all the way.

Change-Id: I35a1348a50c0e8e07d51dfc18847829379166fbf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6853
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-04 21:27:30 +00:00
Vincent Ambo
b69b50feb1 refactor(tvix/eval): split observer traits in two
There are actually two different types of observers, the ones that
observe the compiler (and emitted chunks from different kinds of
expressions), and the ones that trace runtime execution.

Use of the NoOpObserver is unchanged, it simply implements both
traits.

Change-Id: I4277b82674c259ec55238a0de3bb1cdf5e21a258
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6852
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-04 21:27:30 +00:00
Vincent Ambo
d6643f66b1 feat(tvix/eval): use fancy error formatting in REPL
Change-Id: I8d5652d797b012bc3d5248ca2b2d0c87572dbf2e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6851
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
2022-10-04 21:04:03 +00:00
Vincent Ambo
ee0657c292 fix(tvix/eval): forward thunk error codes from inner errors
Until we can display a chained representatino of errors in thunks, it
is most useful to forward the error code from the innermost error to
the user.

Change-Id: I8d67254d52313be40387f080e57966c001e0d51c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6854
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-04 13:13:20 +00:00
Vincent Ambo
89dc26cece feat(tvix/eval): implement builtins.currentTime
Returns time since epoch in seconds.

This has a slight behaviour difference from Nix, in that we don't pin
the time between REPL entries (Nix pins it for the program lifetime),
but this is probably inconsequential as long as it is pinned during an
evaluation.

Change-Id: I010c02e93097a209d8ad69e278397c7e30e54c86
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6846
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: wpcarro <wpcarro@gmail.com>
2022-10-04 08:03:50 +00:00
Vincent Ambo
f0179c92d3 refactor(tvix/eval): allow impure Value builtins
Allows impure builtins that have a different shape than a Rust
function pointer; specifically this is required for
builtins.currentTime which does not work in WASM.

Change-Id: I1362d8eeafe770ce4d1c5ebe4d119aeb0abb5c9b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6849
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: wpcarro <wpcarro@gmail.com>
2022-10-04 08:03:50 +00:00
Vincent Ambo
0537d88078 feat(tvix/eval): implement builtins.any
Change-Id: I640ee20e7c0a68c4e024a577e429fed9b3a49ece
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6845
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-10-03 17:39:09 +00:00
Vincent Ambo
844d288949 feat(tvix/eval): implement builtins.all
Change-Id: I19ec2b2194681efd73041f4aa1e5f2c893e839c2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6844
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-10-03 17:39:09 +00:00
Vincent Ambo
939b2194fe feat(tvix/eval): implement builtins.concatLists
Concatenates (but not flattens) a list of lists.

Change-Id: I692e0b3e7b5a5ff93d5768d3a27849b432ec5747
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6843
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-03 07:53:21 +00:00
Vincent Ambo
3c9520a4e5 refactor(tvix/eval): implement IntoIterator for NixList
This is the same code as before, just moved into a trait impl to gain
access to stuff that needs IntoIterator

Change-Id: Iff9375cd05593dd2681fa85ccc7f4554bf944a02
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6842
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-03 07:53:21 +00:00
Vincent Ambo
8d95e35ced fix(tvix/eval): do not fail when finalising non-capturing values
This can actually legitimately be emitted by the compiler currently
when compiling formals with default values. See the scope6 test from
the Nix test suite for an example.

We should restructure this slightly to be able to reintroduce a
runtime error here in case something was compiled incorrectly.

Change-Id: Ib81f0f58ae0e850db9fbc459458b7bd0d3ac6f23
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6841
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-03 07:50:41 +00:00
Vincent Ambo
8336577c41 feat(tvix/eval): implement tail-calling of __functor attributes
This implements __functor calling in situations where `OpTailCall` is
used, but not yet for `OpCall`.

For some reason I have not yet figured out, this same implementation
does not work in call_value, which means that it also doesn't yet work
in builtins that apply functions.

Change-Id: I378f9065ac53d4c05166a7d0151acb1f55c91579
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6826
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-10-03 07:50:41 +00:00
Griffin Smith
c1d8cee215 feat(tvix/eval): Add passthru build for benchmark binaries
Add a new derivation target to the passthru of tvix.eval that builds the
benchmark binaries, *and* copies them to the outupts of the derivation
via the (somewhat arcane) `copyBinsFilter` jq script arg to naersk. This
is a bit annoying because (as far as I can tell) the derivations
returned by naersk aren't directly overridable, so we have to explicitly
fixpoint the attrs we're passing.

Also, since this is now a separate target to build the benchmarks, we
can remove `--all-targets` from the build of `tvix-eval` itself since
that was only added to build benchmarks in CI, and make
regular (non-benchmark) builds a bit faster.

Change-Id: I136b8526790545e93b1ae666abaefb51cbbee390
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6847
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-10-02 22:43:34 +00:00
sterni
1e25ba1b09 docs(tvix/eval): start doc about problematic/weird lang behavior
The idea is that we can keep track of the more unexpected behavior,
behavior that maybe should not be a thing at all and behavior we are not
sure about yet.

Change-Id: I70933f00af1230a7ab9d30e917b61199fe571caf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6803
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-01 12:30:17 +00:00
Vincent Ambo
68a4d4a759 fix(tvix/eval): fix thunk borrowing error in force_for_output
This function previously kept a borrow in the form of the
`Thunk::value` result alive while performing arbitrary actions in the
VM, which caused a borrowing error in the test case attached.

The `Ref` value must never be used in cases where control flow is
passed to other parts of the VM.

Change-Id: I41d10aa1882a2166614b670e8ba77aab0e67deca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6825
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-30 12:31:14 +00:00
Vincent Ambo
746f1ee702 test(tvix/eval): add simple nested key tests in let & rec attrs
Change-Id: Icdc41ae383cd7cd1531c65c97d955bc59a56489a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6809
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-30 12:31:14 +00:00
Vincent Ambo
6c5e83f8bc chore(tvix/eval): remove unused field in TrackedBindings
Change-Id: I65e31e9173e4f5bba19cc4e3d45eb4f8bf91b424
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6808
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-30 12:31:14 +00:00
Vincent Ambo
f0f5435e25 test(tvix/eval): reactivate nested key tests in plain attribute sets
Change-Id: Id25cde5a6562e1598dcbbf7945ecdfacac5faed7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6807
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-30 12:31:14 +00:00
Vincent Ambo
da1e3e9ac5 feat(tvix/eval): implement nested keys
This finishes up the implementation of nested keys after the key
insight that the nesting level does not need to be tracked, and
instead the attribute iterator can simply be retained inside the
structures as is (in an advanced state).

With this implementation, when encountering a nested key, the Tvix
compiler will first analyse whether there is already a matching
binding that can be merged (i.e. a binding that is a literal attribute
set), and perform the merge, or otherwise create a new recursive set
of bindings in which the entry is inserted with the path iterator
advanced beyond the first name component.

With this, all the logic simply applies recursively until there are no
more nested bindings (i.e. until all iterators are "empty").

Note that this has one (potentially insignificant) deviation from Nix
currently: If a non-mergable value is supplied (e.g. `a.b = 1; a =
2;`), Tvix will emit a *runtime* error (whereas it is *parse* time in
Nix) as the branch which could statically analyse this is currently
unreachable. There's a TODO for this, so we can fix it up later.

Change-Id: I53df70e09614ff4281a70b80eac7da3beca12da9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6806
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-30 12:31:14 +00:00
Vincent Ambo
9cd5f03835 refactor(tvix/eval): split out AttributeSet::from_ast helper
Change-Id: Id43dbd06aef14cf01b4901d9b3668d790cd2b5ae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6805
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-09-30 07:07:17 +00:00
Vincent Ambo
9e9dde0106 chore(tvix/eval): remove nesting_level tracking
This is actually quite useless, as we can just pass
`AstChildren<ast::Attr>` around after partially consuming it.

Change-Id: If0aefa2b53fc801fced1ae0709bff93966bf19f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6804
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-09-30 07:07:17 +00:00
Vincent Ambo
ccf9dd651b refactor(tvix/eval): clean up representation flip in bindings
When encountering a nested binding for the first time, cleanly flip
the representation to `Binding::Set` in `Binding::merge` before
proceeding with the actual merge.

This reduces the number of points where we have to deal with the (soon
to be slightly more complex) construction of the nested binding
representation.

Change-Id: Ifd43aac7b59ebd15a72c3ec512386a5bcf26ec13
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6802
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-29 17:46:02 +00:00
Vincent Ambo
18fcf0d79d feat(tvix/eval): (partially) track nesting level of attrsets
This adds the scaffolding required for tracking the nesting level (and
appropriately skipping the correct amount of attrpath entries when
inserting nested sets).

In order for all of this to work correctly, we can no longer track
`AttrpathValue` directly in the entries vector as rnix does not allow
us to construct values of that type - so instead we have to track its
inner components.

Change-Id: Icb18e105586bf6c247c2e66c302cde5609ad9789
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6801
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-29 17:46:02 +00:00
Vincent Ambo
cece9eae4a feat(tvix/eval): merge attribute sets in bindings
This is a significant step towards correctly implemented nested
bindings. All attribute sets defined within the same binding scope
will now be merged as in Nix, if they use the same key.

Change-Id: I13e056693d5e73192280043c6dd93b47d1306ed6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6800
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-29 17:46:02 +00:00
Vincent Ambo
0cee44838c feat(tvix/eval): add error kind for unmergeable nested attributes
Change-Id: Ic5e6d1bf2625c33938360affb0d1a7c922af11bf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6799
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-29 17:46:02 +00:00
Vincent Ambo
3f34af205f feat(tvix/eval): add scaffolding for merging nested attribute sets
This sets up the required logic for finding and merging attribute sets
into nested bindings if they exist. This is absolutely not complete
yet and can, at this commit, probably cause undefined runtime
behaviour if nested attributes are specified.

The basic idea is that a new helper function on the `TrackedBindings`
struct is called with each encountered attribute and determines
whether the new entry can be merged into an existing attribute or not.

Right now the only effect this has in practice is that a new error
becomes available if somebody attempts to cause a merge into an
inherited key.

Change-Id: Id010df3605055eb1ad7fa65241055889dd21bab0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6798
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-29 17:46:02 +00:00
Vincent Ambo
09a57e7857 refactor(tvix/eval): emit OpAttrs inside of compile_bindings
This needs to move here so that we can reuse compile_bindings for the
nested attribute sets we're about to start constructing.

Change-Id: Ie83f52f7e1d128886e96a1da47792211fa826f21
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6796
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-29 11:47:47 +00:00
Vincent Ambo
82df0b432a refactor(tvix/eval): introduce TrackedBindings struct
This struct will be the key to correctly compiling nested bindings, by
having insertions flow through some logic that will attempt to bind
attribute-set-like things when encountering them.

Change-Id: I8b5b20798de60688f3b6dc4526a460ebb2079f6e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6795
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-29 11:47:47 +00:00