Commit graph

66 commits

Author SHA1 Message Date
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
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
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
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
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
Adam Joseph
7606e62a2f feat(tvix/eval): add CoercionKind::ThunksOnly
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I92acb7e6099a4796d953b2d4d02cca4076ed0fb1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7426
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-11-28 20:05:33 +00:00
jhahn
d00030128e feat(tvix/eval): detect division by zero
This detects if the second argument of a division is a zero (either as integer
or as float). If so, an error message is displayed.

This fixes b/219.

Change-Id: I50203d14a71482bc757832a2c8dee08eb7d35c49
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7258
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2022-11-10 13:12:05 +00:00
Vincent Ambo
4ff06ba67d feat(tvix/eval): add TvixBug error kind
This can be raised in cases where some panics lurk (e.g. indexed
accesses).

Change-Id: I93f4d60568277e9c5635aa52f378645626d68c5e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7057
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-10-22 18:30:12 +00:00
sterni
64bb501de1 fix(tvix): distinguish search- and relative path resolution errors
Failures to resolve a nix search path lookup in angle brackets can be
caught using tryEval (if it reaches the runtime). Resolving relative
paths (either to the current directory or the current user's home) can
never be caught, even if they happen inside a thunk at runtime (which is
currently the case for home-relative paths).

Change-Id: I7f73221df66d82a381dd4063358906257826995a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7025
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-21 00:11:29 +00:00
Griffin Smith
2a3d498104 feat(tvix/eval): Validate closed formals
Validate "closed formals" (formal parameters without an ellipsis) via a
new ValidateClosedFormals op, which checks the arguments (in an attr set
at the top of the stack) against the formal parameters on the Lambda in
the current frame, and returns a new UnexpectedArgument error (including
the span of the formals themselves!!) if any arguments aren't allowed

Change-Id: Idcc47a59167a83be1832a6229f137d84e426c56c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7002
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-17 11:29:49 +00:00
Griffin Smith
5eb89be682 feat(tvix/eval): Implement builtins.fromJSON
Using `serde_json` for parsing JSON here, plus an `impl FromJSON for
Value`. The latter is primarily to stay "dependency light" for now -
likely going with an actual serde `Deserialize` impl in the future is
going to be way better as it allows saving significantly on intermediary
allocations.

Change-Id: I152a0448ff7c87cf7ebaac927c38912b99de1c18
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6920
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-15 20:35:22 +00:00
Adam Joseph
2e0a4aaa84 feat(tvix/eval): From<Utf8Error> for ErrorKind
Change-Id: I074d9e862fbdd4e78e443cbaf0e77c7ffe825a10
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6911
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-12 04:22:44 +00:00
Vincent Ambo
019ea51e5c fix(tvix/eval): format nested compiler errors in fancy output
Instead of just printing the number of errors (useless!) actually emit
separate diagnostics for each nested error.

Change-Id: I97b53c3276c906af5def89077b5b6ba6ec108b37
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6933
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 22:07:22 +00:00
Griffin Smith
75f637c1f5 fix(tvix/eval): path resolution errors are catchable
Despite this not being documented, `tryEval` is empirically able to
catch errors caused by a <...> path not resolving (and nixpkgs depends
on this).

Change-Id: Ia3b78a2d9d2d0c603aba829518b351102dc55396
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6926
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-10-10 20:58:14 +00:00
Griffin Smith
4fd18cbc9a feat(tvix/eval): Implement builtins.tryEval
With asserts compiled using conditional jumps, this ends up being quite
straightforward - the only real tricky bit is that we have to know
whether an error can or can't be handled.

Change-Id: I75617da73b7a9c5cdd888c0e26ae81d2c5c0d714
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6924
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-10-10 20:31:10 +00:00
William Carroll
41ddc37725 feat(tvix/eval): Support builtins.readDir
Co-authored-by: Griffin Smith <root@gws.fyi>
Change-Id: I5ff19efbe87d8f571f22ab0480500505afa624c5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6552
Autosubmit: wpcarro <wpcarro@gmail.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 19:36:49 +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
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
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
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
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
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
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
e31f8f735f chore(tvix/eval): fix all current clippy lints
Change-Id: I28d6af8cb408f8427a75d30b9120aaa809a1ea40
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6784
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-29 11:47:47 +00:00
Vincent Ambo
846215ae2b refactor(tvix/eval): generalise error variant for dynamic keys
Change-Id: I08f40b4b53652a519e76d6e8344c7c3fe10a0689
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6767
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-28 00:00:05 +00:00
Vincent Ambo
489395448f feat(tvix/eval): track other type in NotCallable error kind
This makes for slightly nicer error messages if something isn't, well,
callable.

Change-Id: I821c8d7447b93aea9ccaaa52ed329de0cca4b18e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6718
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-20 23:48:57 +00:00
Vincent Ambo
876c477256 feat(tvix/eval): implement builtins.map
As we already have a VM passed to the builtins, we can simply execute
the provided closure/lambda in it for each value.

The primary annoyance with this is that we have to clone the upvalues
for each element, but we can try making this cheaper in the
future (it's also a general problem in the VM itself).

Change-Id: I5bcf56d58c509c0eb081e7cf52f6093216451ce4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6714
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-20 23:37:53 +00:00
William Carroll
fefa8c55c4 feat(tvix/eval): Support builtins.tail
TL;DR:
- support `builtins.tail`
- define `ErrorKind::TailEmptyList` and canonical error code
- support basic unit tests

Unsure whether or not the error should be a dedicated `ErrorKind`...

Change-Id: Iae90fda1bb21ce7bdb1aaa2aeb2b8c1e6dcb0f05
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6545
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-09-19 00:57:11 +00:00
William Carroll
2fe18e4486 feat(tvix/eval): Support builtins.substring
Nix's `builtins.substring`:
- doesn't accept negative indexes for `beg` or `end`. Compare the error messages
  for:
  - `builtins.substring -3  5 "testing"`
  - `builtins.substring  3 -5 "testing"`
  - `builtins.substring -3 -5 "testing"`
- returns an empty string when `beg >= end`
- allows `end` to exceed the length of the input string

Change-Id: I83af7a099d81b6d537ebe5029d946c7031cb7113
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6555
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-09-19 00:51:10 +00:00
Griffin Smith
d431aa7743 fix(tvix/eval): Emit errors for invalid integers
Invalid integers (eg integers that're too long) end up as error returns
on the `.value()` returned from the literal in the AST - previously we'd
unwrap this error, causing it to panic the compiler, but now we've got a
nice error variant for it (which just unwraps the underlying
std::num::ParseIntError).

Change-Id: I50c3c5ba89407d86659e20d8991b9658415f39a0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6635
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-18 16:40:14 +00:00
William Carroll
3a67a14009 feat(tvix/eval): Support builtins.elemAt
(Attempt to) index into a list.

Change-Id: I3592e60a79e64d265e34100d4062041b0b410e00
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6551
Reviewed-by: wpcarro <wpcarro@gmail.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
2022-09-17 12:54:14 +00:00
sterni
067f2b16f6 feat(tvix/eval): implement Value::coerce_to_path()
This function is necessary for all builtins that expect some form of
path as an argument. It is merely a wrapper around coerce_to_string that
can shortcut if we already have a path. The absolute path check is done
in the same way as in C++ Nix for compatibility, although it should
probably be revised in the long term (think about Windows, for example).

Since coercing to a path is not an operation possible in the language
directly, this function can live in the builtins module as the only
place it is required.

Change-Id: I69ed5455c00d193fea88b8fa83e28907a761cab5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6574
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-09-15 20:58:00 +00:00
William Carroll
85b3f17007 feat(tvix/eval): Support builtins.head
TL;DR:
- support `builtins.head`
- define `ErrorKind::IndexOutOfBounds` and canonical error code
- support basic unit tests

Change-Id: I859107ffb4e220cba1be8c2ac41d1913dcca37ff
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6544
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-09-15 16:48:24 +00:00
sterni
da1d71a4e8 feat(tvix/eval): implement correct toString behavior
Implement C++ Nix's `EvalState::coerceToString` minus some of the Path
/ store handling. This is currently only used for `toString` which does
all possible coercions, but we've already prepared the weaker coercion
variant which is e.g. used for builtins that expect string arguments.

`EvalState::coerceToPath` is still missing for builtins that need a
path, but it'll be easy to build on top of this.

Change-Id: I78d15576b18921791d04b6b1e964b951fdef22c6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6571
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-09-15 11:47:30 +00:00
Vincent Ambo
0f59fe6601 feat(tvix/eval): implement initial fancy formatting for errors
This very closely follows the way it's done for warnings, but errors
have a lot more information available in some cases which we do not
surface yet.

Note also that due to requiring the `CodeMap`, this is not yet called
from eval.rs as the way that is threaded through needs to be
refactored, so only the method for reporting these errors as strings
is implemented so far.

Next steps for this will be to add a generic diagnostics module that
reduces some of the boilerplate for this between warnings & errors,
and which will also give us a good point in the future to switch to a
fancier diagnostics crate.

Change-Id: If6bb209f8e7a568d866e516a90335b9b2afbf66d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6534
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-09-13 14:41:57 +00:00
Vincent Ambo
1844c788f5 refactor(tvix/eval): remove todo!() calls in compiler
It is impossible for tvixbolt to recover from panics, so the user
experience of typing an expression using an unsupported feature was
that it would get sad and stop responding to input.

Instead, raise a normal value-level error of a new variant and
continue where possible.

Change-Id: Ibe016c92cacb87b85095c0f83758eddc6468053e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6528
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 21:13:24 +00:00
Vincent Ambo
4e06e5d2ba fix(tvix/eval): reintroduce 'InvalidAttribuetName' error variant
As pointed out by sterni in cl/6205, this is actually possible in
syntactically valid expressions like

  { ${12 + 13} = 12; }

Change-Id: Id8a1e3aceb551f288f9050c4eea563eb6572f1a7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6461
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
06909f1821 fix(tvix/eval): fix doc comment syntax where applicable
As pointed out by grfn on cl/6091

Change-Id: I28308577b7cf99dffb4a4fd3cc8783eb9ab4d0d6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6460
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
0a13d267f0 fix(tvix/eval): thread thunk forcing errors through correctly
With this, if an error occurs while forcing a thunk (which is very
likely) it is threaded through to the top by wrapping it in the
ErrorKind::ThunkForce variant.

We could use this to generate "stacktrace-like" error output if we
wanted, or simply jump through and discard everything except the
innermost error.

Change-Id: I3c1c8708c2f73ae062815adf490ce935b1979da8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6409
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 07:59:15 +00:00
Vincent Ambo
377ba19d75 feat(tvix/eval): ensure all errors always carry a span
Previously error spans were optional because the information about
code spans was not available at runtime. Now that this information has
been added, the error type will always carry a span.

This change is very invasive all throughout the codebase. This is due
to the fact that many functions that are called *by* the VM expected
to return `EvalResult`, but this no longer works as the span
information is not available to those functions - only to the VM
itself.

To work around this the majority of these functions have been changed
to return `Result<T, ErrorKind>` instead and an accompanying macro in
the VM constructs the "real" error.

Note that this implementatino currently has a bug where errors
occuring within thunks will yield the location at which the thunk was
forced, not the location at which the error occured within the code.
This will be fixed soon, but the commit is large enough as is.

Change-Id: Ib1ecb81a4d09d464a95ea7ea9e589f3bd08d5202
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6408
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 07:59:15 +00:00
Vincent Ambo
55d21a1389 refactor(tvix/eval): store spans instead of nodes in Warning/Error
Another step towards being able to report accurate errors. The codemap
spans contain strictly more accessible information, as they now retain
information about which input file something came from.

This required some shuffling around in the compiler to thread all the
right information to the right places.

Change-Id: I18ccfb20f07b0c33e1c4f51ca00cd09f7b2d19c6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6404
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:26 +00:00
Vincent Ambo
9a783e50a4 feat(tvix/eval): implement OpForce in VM
This operation forces the evaluation of a thunk.

There is some potential here for making an implementation that avoids
some copies, but the thunk machinery is tricky to get right so the
first priority is to make sure it is correct by keeping the
implementation simple.

Change-Id: Ib381455b02f42ded717faff63f55afed4c8fb7e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6352
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 15:25:59 +00:00
Vincent Ambo
a52db14820 feat(tvix/eval): detect illegally shadowed variables
Nix does not allow things like `let a = 1; a = 2; in a`, but doing it
across depths is allowed.

Change-Id: I6a259f8b01a254b433b58c736e245c9c764641b6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6301
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-04 17:40:10 +00:00
Vincent Ambo
bd0fc69f07 feat(tvix/eval): implement 'throw' and 'abort' builtins
These do essentially the same, but return different error variants as
upstream Nix considers `throw` to be (sometimes) catchable.

Change-Id: I1a9ea84567d46fb37287dbf3f3f67052f9382cca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6259
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-02 12:59:23 +00:00
Vincent Ambo
1239a85e23 feat(tvix/eval): implement opcode for function calls in VM
Nix functions always have a single argument and we do not yet make
efforts to optimise this in Tvix for known multi-argument functions
being directly applied.

For this reason, the call instruction is fairly simple and just calls
out to construct a new call frame.

Note that the logic for terminating the run loop has moved to the top
of the dispatch; this is because the loop run needs to be skipped if
the call frame for the current lambda has just been dropped.

Change-Id: I259bc07e19c1e55cd0a65207fa8105b23052b967
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6249
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-09-02 12:31:04 +00:00
Vincent Ambo
f7305eed47 refactor(tvix/eval): collect vector of errors in compiler
Instead of exiting the compiler at the first sight of an error,
skip any erroneous nodes and continue compiling, collecting more
errors along the way.

This paves the way for nicer error reporting in which multiple errors
can be reported at once, avoiding situations in which users are
hunting a fault error-by-error and possibly getting distracted by
less useful output.

Change-Id: I80c9a87272e33a31297167ae2eb2706a46adf15a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6236
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-09-01 21:40:50 +00:00