Commit graph

605 commits

Author SHA1 Message Date
Adam Joseph
f2bf65a40b fix(tvix/eval): remove overlapping instances
I broke the build.

I didn't understand that before hitting "submit" you need to re-test
your changes on latest HEAD (and that CI doesn't do that for you); I
failed to re-test cl/6912 following the merge of cl/6907.

This commit fixes the build by removing the overlapping instances.

Change-Id: I2a720d2c60cc7103b350f78102a8998f93bac828
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6965
Tested-by: BuildkiteCI
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-12 07:25:51 +00:00
Adam Joseph
4e94a2696b feat(tvix/eval): From<Into<NixString>> for Value
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I27615baf4104ab96600708b12a780599a3714bae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6912
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-12 04:23:07 +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
sterni
fcd5e53703 fix(tvix/eval/builtins): force acc not list element in foldl'
When investigating discrepancies between foldl' in tvix and C++ Nix,
I discovered that C++ Nix's foldl' doesn't seem to be strict at all.
Since this seemed wrong, I looked into Haskell's foldl' implementation
which doesn't force the list elements (`val` in our code), but the
accumulation value (`res` in our code). You can look at the code here:
https://hackage.haskell.org/package/base-4.17.0.0/docs/src/GHC.List.html#foldl%27

This actually makes a lot of sense: If `res` is not forced after each
application of `op`, we'll end up thunks nested as deeply as the list is
long, potentially taking up a lot of space. This can be limited by
forcing the `res` thunk before applying `op` again (and creating a new
thunk).

I've also PR-ed an equivalent change for C++ Nix at
https://github.com/NixOS/nix/pull/7158. Since this is not merged nor
backported to our Nix 2.3 fork, I've not copied the eval fail test yet,
since it wouldn't when checking our tests against C++ Nix in depot.

Change-Id: I34edf6fc3031fc1485c3e714f2280b4fba8f004b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6947
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-10-11 15:53:29 +00:00
Griffin Smith
1181bd78fc feat(tvix/eval): Allow directly evaluating an expr via main
This *maybe* should do something to check that we don't pass both a file
and an expr, but for now this is useful enough to cut corners (plus
we're probably due for a CLI revamp eventually anyway).

Change-Id: Id44357074150b336b6215ba596cc52d01d037dbd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6941
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-11 00:33:49 +00:00
Griffin Smith
4283f0139a feat(tvix/eval): Implement builtins.removeAttrs
Change-Id: I28910991a0108436a42ac7bf3458f9180a44154e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6928
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-11 00:33:39 +00:00
Griffin Smith
562c50fadd feat(tvix/eval): Implement builtins.trace
This is currently implemented with a simple println inline, but in the
future we could hook into this via something pluggable on the VM.

Change-Id: Idd9cc3b34aa13d6ebc64c02aade81ecdf439656a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6938
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-11 00:16:40 +00:00
Griffin Smith
4a058a9c00 fix(tvix/eval): Pop frames even if running op fails
Previously, the VM assumed that if an error was returned from `run()`,
the evaluation was "finished" and the state of the VM didn't matter.
This used to be a reasonable assumption, but now that we've got
`tryEval` around we need to actually make sure that we clean up after
ourselves if we're about to return an error. Specifically, if the *last*
instruction in an evaluation frame returns an error, we previously
wouldn't pop that evaluation frame, which could cause all sorts of
bizarre errors based on what happened to be in the stack at the time.

This commit splits out a `run_op` method from `VM::run`, and uses that
to check the evaluation frame return condition even if the op we're
running is about to return an error, and pop the evaluation frame if
we're at the last instruction.

Change-Id: Ib40649d8915ee1571153cb71e3d76492542fc3d7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6940
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-11 00:08:05 +00:00
Vincent Ambo
76e0c37b9e feat(tvix/eval): observe stack after exiting call frames/builtins
Change-Id: I1937d37551503a0b6bb0ac899d067302e4791e5f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6939
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-11 00:07:39 +00:00
Vincent Ambo
8e122574c2 fix(tvix/eval): implement functor calling for non-tail-calls
Change-Id: I1113921c46010021b61c412d74d60193c156e0f1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6937
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-11 00:07:38 +00:00
Griffin Smith
06ec4bebe7 fix(tvix/eval): Actually trace spans for thunks
Currently, the span on *all* thunk force errors is the span at which the
thunk is forced, which for recursive thunk forcing ends up just being
the same span over and over again. This changes the span on thunk force
errors to be the span at which point the thunk is *created*, which is a
bit more helpful (though the printing atm is a little... crowded). To
make this work, we have to thread through the span at which a thunk is
created into a field on the thunk itself.

Change-Id: I81474810a763046e2eb3a8f07acf7d8ec708824a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6932
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 23:51:09 +00:00
Griffin Smith
90ec632fd1 feat(tvix/eval): Implement builtins.getEnv
Change-Id: I09f512a60989a37184e73e521d4a3aa23f33a1a8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6922
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Reviewed-by: kanepyork <rikingcoding@gmail.com>
2022-10-10 23:38:25 +00:00
Griffin Smith
9669fa8ff1 feat(tvix/eval): Implement builtins.readFile
Change-Id: If3fd0b087009a2bfbad8bb7aca0aa20de906eb12
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6921
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Reviewed-by: kanepyork <rikingcoding@gmail.com>
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
2022-10-10 23:38:25 +00:00
Vincent Ambo
1f84d90811 refactor(tvix/eval): after calling, the caller has to pop
Previously the various call functions either returned `EvalResult<()>`
or `EvalResult<Value>`, which was confusing.

Now only vm::call_with returns a Value directly, and other parts of
the API just leave the stack top in the post-call state.

This makes it easier to reason about what's going on in non-tail-call
cases (which are making a comeback).

Change-Id: I264ffc683a11aca72dd06e2220a5ff6e7c5fc2b0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6936
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-10-10 23:36:49 +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
2592113435 fix(tvix/eval): Thunk if expr
Since the body of an `if` expr can refer to deferred upvalues, it needs
to be thunked so when we actually compile those deferred upvalues we
have something for the finalize op to point at. Without this all sorts
of weird things can happen due to the finalize op being run in the wrong
lambda context, up to and including a panic.

Change-Id: I040d5e1a7232fd841cfa4953539898fa49cbbb83
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6929
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-10-10 20:35:11 +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
Griffin Smith
0b8a967aca feat(tvix/eval): Implement builtins.pathExists
Change-Id: Ife8a690e9036868964771893ab29a9ae3a2d2365
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6919
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 20:23:41 +00:00
Griffin Smith
273ba73754 feat(tvix/eval): Initial resolution of <...> paths
This commit implements (lazy) resolution of `<...>` paths via either the
NIX_PATH environment variable, or the -I command-line flag - both
handled via EvalOptions. As a result, EvalOptions can no longer derive
Copy, meaning we have to clone it at each line of the repl - this is
probably not a huge deal as repl performance is not exactly an inner
loop and we're not cloning very much.

Internally, this works by creating a thunk which pushes a constant
containing the string inside the brackets to the stack, then a new
opcode to resolve that path via the `NixPath`. To get that opcode to
work, we now have to pass in the NixPath when constructing the VM.

This (intentionally) leaves out proper implementation of path resolution
via `findFile` (cppnix just calls whatever identifier called findFile is
in scope!!!) as that's widely considered a bit of a misfeature, but if
we do decide to implement that down the road it likely wouldn't be more
than a few extra ops within the thunk introduced here.

Change-Id: Ibc979b7e425b65cbe88599940520239a4a10cee2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6918
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 20:23:41 +00:00
Griffin Smith
5e2b44b416 feat(tvix/eval): Add a struct implementing NIX_PATH
Add a simple struct implementing both the string parsing and path
resolution rules of Nix's `NIX_PATH` environment variable, for use in
resolving `<...>`-style paths

Change-Id: Ife75f39aa5c12928278d81fe428fbadc98bac5cc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6917
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2022-10-10 20:23:41 +00:00
Griffin Smith
0e9f5d6890 feat(tvix/eval): Allow adding strings to paths
Implement adding paths and strings via OpAdd. Since the nix rules are
quite obscure, I'm electing to test this one with an oracle test to
avoid the danger of getting the actual asserted result wrong.

Change-Id: Icdcca3690ca2e8459e386c1f29cc48eaaa39e9a3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6914
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 20:23:41 +00:00
Griffin Smith
66a35de3b6 feat(tvix/eval): Implement builtins.concatStringsSep
Change-Id: I6e46bcdbf3b5258b60edb017709fee577eb8ec74
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6907
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 20:23:41 +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
899fbdbddb refactor(tvix/eval): Compile OpAssert using conditional jumps
In order to behave nicely with tryEval, asserts need to leave the
instruction pointer in a reasonable place even if they fail - whereas
with the previous implementation catching a failed assert would still
end up running the op for the *body* of the assert. With this change, we
compile asserts much more like an `if` expression with conditional jumps
rather than having an OpAssert op.

Change-Id: I1b266c3be90185c84000da6b1995ac3e6fd5471b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6925
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 17:51:22 +00:00
Griffin Smith
8190046190 feat(tvix/eval): Implement builtins.elem
Change-Id: Id99c1d33f87ad9866990d3483d3531e9e48f861f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6916
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 17:42:48 +00:00
Griffin Smith
0b06d94606 refactor(tvix/eval): Abstract away calling functions
The process of calling a function from a builtin, especially if it's got
more than 1 arrgument, is reasonably involved and easy to get wrong due
to having to interact directly with the stack - instead of having that
done entirely manually in builtins, this wraps it up in a new
`call_with` function which handles pushing arguments onto the stack and
recursively calling the (partially applied) function.

Change-Id: I14700c639a0deca53b9a060f6d70dbc7762e9007
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6910
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-10-10 15:34:31 +00:00
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