Commit graph

83 commits

Author SHA1 Message Date
Florian Klink
79531c3dab refactor(tvix/nix-compat): support non-unicode Derivations
Derivations can have non-unicode strings in their env values, so the
ATerm representations are not necessarily String anymore, but Vec<u8>.

Change-Id: Ic23839471eb7f68d9c3c30667c878830946b6607
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8990
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Autosubmit: flokli <flokli@flokli.de>
2023-07-31 21:41:38 +00:00
Florian Klink
0dea3086f5 docs(tvix/cli/refscan): fix comment
The comment still mentions Aho-Corasick, which isn't correct.

Change-Id: I846a2ca9ea7075c2456ca6ef04a132ff6161227a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8991
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-07-31 09:01:34 +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
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
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
Florian Klink
b5e37869e6 refactor(tvix/store/pathinfosvc): use Arc<dyn …>
This removes the use of generics, like previously done with Blob and
Directory services.

Change-Id: I7cc8bd1439b026c88e80c11e38aafc63c74e5e84
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8751
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-12 13:27:05 +00:00
Florian Klink
aa7bdc1199 refactor(tvix/store): use Arc instead of Box
This allows us to blob services without closing them before putting them
in a box.
We currently need to use Arc<_>, not Rc<_>, because the GRPC wrappers
require Sync.

Change-Id: I679c5f06b62304f5b0456cfefe25a0a881de7c84
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8738
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2023-06-12 10:24:24 +00:00
Florian Klink
7725eb53ad refactor(tvix/store): use Box<dyn DirectoryService>
Once we support configuring services at runtime, we don't know what
DirectoryService we're using at compile time.

This also means, we can't explicitly use the is_closed method from
GRPCPutter, without making it part of the DirectoryPutter itself.

Change-Id: Icd2a1ec4fc5649a6cd15c9cc7db4c2b473630431
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8727
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-12 10:24:24 +00:00
Florian Klink
6f85dbfc06 feat(tvix/store/pathinfosvc): add calculate_nar method
Putting this in the PathInfoService trait makes much more sense, we can
have direct control over where/how to cache the results in the
implementation.

This now requires each PathInfoService to hold pointers to BlobService
and DirectoryService.

Change-Id: I4faae780d43eae4beeb57bd5e190e6d1a5d3314e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8724
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-12 10:15:20 +00:00
Florian Klink
8d05c0ceaa refactor(tvix/src/nar): drop NARCalculationService
There's only one way to calculate NAR files, by walking through them.

Things like caching such replies should be done closer to where we use
these, composing NARCalculationService doesn't actually give us much.

Instead, expose two functions, `nar::calculate_size_and_sha256` and
`nar::writer_nar`, the latter writing NAR to a writer, the former using
write_nar to only keeping the NAR size and digest.

Change-Id: Ie5d2cfea35470fdbb5cbf9da1136b0cdf0250266
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8723
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2023-06-12 10:15:20 +00:00
Florian Klink
27ff98000b feat(tvix/store): eliminate generics in BlobStore
To construct various stores at runtime, we need to eliminate associated
types from the BlobService trait, and return Box<dyn …> instead of
specific types.

This also means we can't consume self in the close() method, so
everything we write to is put in an Option<>, and during the first close
we take from there.

Change-Id: Ia523b6ab2f2a5276f51cb5d17e81a5925bce69b6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8647
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-12 10:15:20 +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
Florian Klink
83c1546b9a chore(tvix/store): add fuse feature
This brings in fuse (via the `fuser` crate), and adds pkg-config and
libfuse to the dev shell, so `cargo build` can link against it.

Change-Id: I0d11607490e27d946bdf92b0b9e45f9ab644ba74
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8664
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-10 14:48:48 +00:00
Linus Heckemann
26fed61750 fix(tvix/cli): fix refscan when no paths are referenced
Before, the construction of a TwoByteWM would panic when no patterns
were provided, as in `tvix --expr 'builtins.toFile "snens" "soos"'`.

Change-Id: I25ed498c475523aec5baf8683b23059fadabb21c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8697
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-06-02 13:19:56 +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
Florian Klink
93fa47f2ae feat(tvix/cli): add --no-warnings argument
This will prevent tvix from printing any warnings.

As a followup, we can also thread this parameter through into the
evaluator itself, to prevent warnings from being constructed in first
place.

Change-Id: I15381396f86573484bdd1a73d09034a665638e35
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8646
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-05-27 16:44:29 +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
ea48481eb3 refactor(tvix/cli): wrap NixCompatIO import_cache in RwLock
This allows dropping all &mut self from the EvalIO trait signature.

Change-Id: Ie127b0a459d2996636385d159fcc5f7147e74e2e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8630
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2023-05-25 11:11:59 +00:00
Florian Klink
63047449d7 feat(tvix/cli): use TvixStoreIO instead of NixCompatIO
This switches tvix-cli over from using `NixCompatIO` to `TvixStoreIO`.

For now, we simply instantiate in-memory services instead of getting
fancy with constructors inside tvix-store, but long-term, we might want
to support some URI syntax, to make this configurable at runtime.

nixpkgs eval tests might be fine (and fast!) with a purely in-memory
backend, but other usages might involve talking to a local tvix-store
over gRPC (using the gRPC client, either unix domain socket or even
further away remote), or running tvix-store in "embedded" mode (using
another client than the gRPC client).

Change-Id: I509afd3dc5ce3f2d52b0fb7067748fab820e26ab
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8572
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-05-24 16:04:08 +00:00
Florian Klink
4b00f1d7ac feat(tvix/cli): check nixpkgs eval for pkgs.hello.outPath
We already evaluate this the same as Nix does, so worth adding it into
CI.

Change-Id: I529faccac6e5e16e0bc985ab4c3e0cd07bb23293
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8624
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
2023-05-24 09:17:42 +00:00
Florian Klink
1fb5008237 feat(tvix/cli): introduce mkNixpkgsEvalCheck, add outPath check
This introduces a function that can be instantiated with an attribute
path to instantiate, as well as the expected path (normally interpolated
with the nix evaluator).

Check both pkgs.stdenv.drvPath and pkgs.stdenv.outPath to match.

Change-Id: Id667ed35fa159ff83fedb3017ef8d3271aa42695
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8606
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-05-24 09:17:41 +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
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
Vincent Ambo
64ee21ec86 chore(tvix/cli): remove unnecessary RefCell
This remained around from some previous time where this type was being
cloned around directly, but it's not anymore.

Change-Id: I2c61cf9cecb8e5d7d08644ed20642ee61357bc21
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8580
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-05-18 19:12:11 +00:00
Vincent Ambo
ba4807e1de refactor(tvix/cli): split CLI-specific IO logic into TvixIO type
This adds a wrapper type TvixIO<T: EvalIO>, which can wrap around an
arbitrary EvalIO implementation and perform actions needed for the
Tvix CLI (marking imported paths as known, and handling __corepkgs__).

Change-Id: I5fc1ca199b9f94b21a89103b84575e0f8f58dff9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8579
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-05-18 19:12:11 +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
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
John Ericson
26c68f8e89 refactor(nix-compat): Properly encapsulate store path construction
Before there was code scattered about (e.g. text hashing module and
derivation output computation) constructing store paths from low level
building blocks --- there was some duplication and it was easy to make
nonsense store paths.

Now, we have roughly the same "safe-ish" ways of constructing them as
C++ Nix, and only those are exposed:

- Make text hashed content-addressed store paths

- Make other content-addressed store paths

- Make input-addressed fixed output hashes

Change-Id: I122a3ee0802b4f45ae386306b95b698991be89c8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8411
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-04-09 15:12:21 +00:00
Florian Klink
5f2c2e79e1 refactor(tvix/nix-compat): move build_store_path out of derivation
This doesn't have anything to do with ATerms, we just happen to be using
the aterm representation of a Derivation as contents.

Moving this into store_path/utils.rs makes these things much cleaner -
Have a build_store_path_from_references function, and a
build_store_path_from_fingerprint helper function that makes use of it.

build_store_path_from_references is invoked from the derivation module
which can be used to calculate the derivation path.

In the derivation module, we also invoke
build_store_path_from_fingerprint during the output path calculation.

Change-Id: Ia8d61a5e8e5d3f396f93593676ed3f5d1a3f1d66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8367
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-03-30 14:03:35 +00:00
Vincent Ambo
837c4ebb41 feat(tvix/cli): add --strict flag for evaluation
This toggles whether tvix will evaluate the top-level value and
deep-force it, or return it potentially still containing thunks.

Change-Id: Ie910941e3b6a0f16c5c0cb896d73947626335f4b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8326
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2023-03-22 15:25:35 +00:00
Vincent Ambo
4d465249ef fix(tvix/cli): populate output configuration after walking args
Walking the arguments might encounter an `outputs` output, which might
explicitly (for whatever reason) specify the `out` output.

To prevent dropping FOD settings in this case, we have to populate
that part of the configuration after walking the other attributes.

Change-Id: Iee6a7f0a71e9c9699e79d35e6cb19e1ddb49395d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8312
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-03-15 13:05:53 +00:00
Florian Klink
b55d1f97ce refactor(tvix/nix-compat): -derivation::Hash, +NixHash
This stops using our own custom Hash structure, which was mostly only
used because we had to parse the JSON representation somehow.

Since cl/8217, there's a `NixHash` struct, which is better suited to
hold this data. Converting the format requires a bit of serde labor
though, but that only really matters when interacting with JSON
representations (which we mostly don't).

Change-Id: Idc5ee511e36e6726c71f66face8300a441b0bf4c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8304
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-03-15 11:50:12 +00:00
Florian Klink
8cfd303203 chore(tvix/cli): don't set COREPKGS anymore
Since cl/8213, tvix bundles corepkgs.

Change-Id: I17fa4452a6a1d554ae67b4aed9d9b1e77cb495f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8305
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-03-14 20:50:01 +00:00
Florian Klink
5f260edf7f refactor(tvix/nix-compat): replace calculate_drv_replacement_str
Call this function derivation_or_fod_hash, and return a NixHash.

This is more in line with how cppnix calls this, and allows using
to_nix_hash_string() in some places.

Change-Id: Iebf5355f08ed5c9a044844739350f829f874f0ce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8293
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-03-14 18:26:19 +00:00
Vincent Ambo
c37e41d583 chore(tvix/cli): silence useless warning
Change-Id: I18f567d5dcbbeb934428bf9111eb5fae5fef0342
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8261
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-03-13 20:30:59 +00:00
Vincent Ambo
a59e264457 feat(tvix/cli): bundle corepkgs/fetchurl.nix with tvix-cli
This file which ships with C++ Nix is required for evaluating nixpkgs.
Like C++ Nix, we now inject a pseudo path in EvalIO from which this
will resolve as <nix/fetchurl.nix>

Change-Id: Ic948c476a2cfc6381d5655d308bc2d5fa25b7123
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8213
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
025c67bf4d refactor(tvix/eval): flatten call stack of VM using generators
Warning: This is probably the biggest refactor in tvix-eval history,
so far.

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

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

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

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

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

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

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

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

   Notably, this includes *all* builtins.

This has had some other effects:

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

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

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

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

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

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

Fixes: b/238, b/237, b/251 and potentially others.
Change-Id: I39244163ff5bbecd169fe7b274df19262b515699
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8104
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Aaqa Ishtyaq
0dcbf5dfb9 chore(tvix/cli): iter instead of into_iter for references
This CL removes calling into_iter on a reference, as it will
not move out it's content into resulting iterator.

Change-Id: Ifcc10b7cf33b98453570cbcec3eb82ffaba2ffcb
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8126
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-02-16 22:42:14 +00:00
Vincent Ambo
26b55f8cda fix(tvix/cli): use tvlfyi/wu-manber fork for refscanner
Our fork fixes a small bug (https://github.com/jneem/wu-manber/pull/1)
but it's not clear whether upstream will accept patches, so for now
lets point this directly at our fork.

Change-Id: Iccdcedae3e9a8b783241431787c952561d032694
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8031
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-02-04 12:44:59 +00:00
Vincent Ambo
0dd07440b4 test(tvix/cli): eval nixpkgs.stdenv in CI and assert that it matches
Change-Id: If80194b5fdbf69512217bd4780e416e678045323
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8023
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-02-03 10:47:18 +00:00
Vincent Ambo
38e8c2e959 fix(tvix/cli): keep tracking full paths in known_paths
We need to distinguish explicitly between the paths used for the
scanner, and the paths that populate the derivation inputs. The full
paths must be accessible from the result of the refscanner to populate
drv fields correctly.

This was previously hidden by debug changes that masked actual IO
operations with no-ops.

Change-Id: I037af6e6bbe2b573034d695f8779bee1b56bc125
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8022
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-02-02 23:37:34 +00:00
Vincent Ambo
e6235e2932 feat(tvix/cli): cache imported paths in NixCompatIO
Creates a cache of imported literal files (e.g.
`./default-builder.sh`) which avoids shelling out to Nix for each
instance of the same file.

Note that a better way to tackle this is to create memoizable thunks
for these expressions in the compiler, but we are lacking a little bit
of infrastructure for that at the moment.

Change-Id: Ibc062b20d81e97dd3986e734d225a744e1779fe7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8015
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-02 17:50:44 +00:00
Vincent Ambo
9d6f29a72b refactor(tvix/cli): use Wu-Manber string scanning for drv references
Switch out the string-scanning algorithm used in the reference scanner.

The construction of aho-corasick automata made up the vast majority of
runtime when evaluating nixpkgs previously. While the actual scanning
with a constructed automaton is relatively fast, we almost never scan
for the same set of strings twice and the cost is not worth it.

An algorithm that better matches our needs is the Wu-Manber multiple
string match algorithm, which works efficiently on *long* and *random*
strings of the *same length*, which describes store paths (up to their
hash component).

This switches the refscanner crate to a Rust implementation[0][1] of
this algorithm.

This has several implications:

1. This crate does not provide a way to scan streams. I'm not sure if
   this is an inherent problem with the algorithm (probably not, but
   it would need buffering). Either way, related functions and
   tests (which were actually unused) have been removed.

2. All strings need to be of the same length. For this reason, we
   truncate the known paths after their hash part (they are still
   unique, of course).

3. Passing an empty set of matches, or a match that is shorter than
   the length of a store path, causes the crate to panic. We safeguard
   against this by completely skipping the refscanning if there are no
   known paths (i.e. when evaluating the first derivation of an eval),
   and by bailing out of scanning a string that is shorter than a
   store path.

On the upside, this reduces overall runtime to less 1/5 of what it was
before when evaluating `pkgs.stdenv.drvPath`.

[0]: Frankly, it's a random, research-grade MIT-licensed
     crate that I found on Github:

     https://github.com/jneem/wu-manber

[1]: We probably want to rewrite or at least fork the above crate, and
     add things like a three-byte wide scanner. Evaluating large
     portions of nixpkgs can easily lead to more than 65k derivations
     being scanned for.

Change-Id: I08926778e1e5d5a87fc9ac26e0437aed8bbd9eb0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8017
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-02 17:50:44 +00:00
Florian Klink
99d5cf822a refactor(tvix/cli): use nixhash module for output hash calculation
This covers all the weird corner cases.

Change-Id: I85637e82e8929828064ab562dc8a1c8bf161fffa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7991
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-02-01 15:29:48 +00:00
Vincent Ambo
759f9dbf39 feat(tvix/cli): implement builtins.placeholder
This doesn't require any other corresponding handling *yet*, as the
actual replacements happen in the builder logic (which we delegate to
cppnix at the moment).

Change-Id: I034147c933f05ae427c7a8794647132d108d0ede
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7972
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-01 10:01:40 +00:00
Florian Klink
2d24c5f260 refactor(tvix/nix-compat): absorb //tvix/derivation
Put this in its src/derivation.

Change-Id: Ic047ab1c2da555a833ee454e10ef60c77537b617
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7967
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
2023-01-31 15:16:39 +00:00
Florian Klink
c27bacd905 refactor(tvix): introduce nix-compat crate
Move nixbase32 and store_path into this.

This allows //tvix/cli to not pull in //tvix/store for now.

Change-Id: Id3a32867205d95794bc0d33b21d4cb3d9bafd02a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7964
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-31 13:26:18 +00:00
Florian Klink
8ea93bb646 refactor(tvix/cli/derivation): use if let to destructure
We only do logic here if algo and hash_mode are Some(_)
(and there's an `out` output).

The fact we don't do anything in all in other cases is a bit hidden at
the bottom. Use if let for the destructuring, and drop the other case.

Change-Id: Icc0e38e62947d52d48ef610f754749737977fca9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7966
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-31 13:26:11 +00:00
Florian Klink
6fa91349a9 refactor(tvix/cli): remove unneeded clone
Change-Id: I6f4cb24bdd636af8918a2ade44075af92161c97d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7965
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-31 13:26:11 +00:00