Commit graph

212 commits

Author SHA1 Message Date
sterni
80a71abb48 test(tvix/eval): move division by zero tests into tvix_tests
These were added by us in r/5276, so they should go into our test suite.

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

Change-Id: I48844feeefa9da8ed7e5d85300d52bb5650f82d2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8772
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-14 16:01:19 +00:00
sterni
d5b989ddc0 test(tvix/eval): re-enable blackhole test
Change-Id: Id933f3bd708aa3342b9fd6a5584e65ee11751ff8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8773
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: sterni <sternenseemann@systemli.org>
2023-06-14 15:59:45 +00:00
sterni
5139cc45c2 test(tvix/eval): builtins.substring's behavior with negative args
Change-Id: Ie8b97d174e9d58e33bf08c9b9e0afeeddd089ba8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8700
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-06-12 09:38:08 +00:00
sterni
10c6cb7251 fix(tvix/eval): type check function argument with set pattern
C++ Nix forces and typechecks the passed argument even if it is not
necessary in order to compute the return value of the function. I
discovered this when I thought our formals miscompilation might be that
we are too strict, but doesn't look like it in this case.

Change-Id: Ifb3c92592293052c489d1e3ae8c7c54e4b6b4dc6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8701
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-06-07 15:17:20 +00:00
sterni
3b33c19a9c fix(tvix): don't call function eagerly in genList, map & mapAttrs
mapAttrs, map and genList call Nix functions provided by the caller and
store the result of applying them in a Nix data structure that does not
force all of its contents when forced itself. This means that when such
a builtin application is forced, the Nix function calls performed by the
builtin should not be forced: They may be forced later, but it is also
possible that they will never be forced, e.g. in

    builtins.length (builtins.map (builtins.add 2) [ 1 2 3 ])

it is not necessary to compute a single application of builtins.add.

Since request_call_with immediately performs the function call
requested, Tvix would compute function applications unnecessarily before
this change. Because this was not followed by a request_force, the
impact of this was relatively low in Nix code (most functions return a
new thunk after being applied), but it was enough to cause a lot of
bogus builtins.trace applications when evaluating anything from
`lib.modules`. The newly added test includes many cases where Tvix
previously incorrectly applied a builtin, breaking a working expression.

To fix this we add a new helper to construct a Thunk performing a
function application at runtime from a function and argument given as
`Value`s. This mimics the compiler's compile_apply(), but does itself
not require a compiler, since the necessary Lambda can be constructed
independently.

I also looked into other builtins that call a Nix function to verify
that they don't exhibit such a problem:

- Many builtins immediately use the resulting value in a way that makes
  it necessary to compute all the function calls they do as soon as
  the outer builtin application is forced:

  * all
  * any
  * filter
  * groupBy
  * partition

- concatMap needs to (shallowly) force the returned list for
  concatenation.

- foldl' is strict in the application of `op` (I added a comment that
  makes this explicit).

- genericClosure needs to (shallowly) force the resulting list and some
  keys of the attribute sets inside.

Resolves b/272.

Change-Id: I1fa53f744bcffc035da84c1f97ed25d146830446
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8651
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-05-26 22:35:39 +00:00
Vincent Ambo
ba138712e4 feat(tvix/eval): add Evaluation::strict to toggle top-level deepseq
This makes it possible for callers to control whether they can receive
partially evaluated values from an evaluation or not.

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

Change-Id: Ic048e9ba09c88866d4c3177d5fa07db11c4eb20e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8325
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2023-03-22 13:44:20 +00:00
Vincent Ambo
b78ae941a4 fix(tvix/eval): use coerce_to_string in builtins.substring
This actually uses coercion under the hood in C++ Nix. See the test
for an example.

Change-Id: Id56b364acf269225b6829d0b600e0222f8b3608d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8322
Reviewed-by: andi <andi@notmuch.email>
Tested-by: BuildkiteCI
2023-03-17 19:17:29 +00:00
Vincent Ambo
939cebd0f1 fix(tvix/eval): implement cppnix JSON-serialisation semantics
This drops the usage of serde::Serialize, as the trait can not be used
to implement the correct semantics (function colouring!).

Instead, a manual JSON serialisation function is written which
correctly handles toString, outPath and other similar weirdnesses.

Unexpectedly, the eval-okay-tojson test from the C++ Nix test suite
now passes, too.

This fixes an issue where serialising data structures containing
derivations to JSON would fail.

Change-Id: I5c39e3d8356ee93a07eda481410f88610f6dd9f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8209
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
dfd0066de5 fix(tvix/eval): handle toJSON on attribute sets with outPath
These are serialised as the serialisation of the value of that field.

Change-Id: Ida51708b1f43ce09b0ec835f4e265918aa31dd09
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8205
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
7d339d2762 fix(tvix/eval): handle __toString when JSON-serialising attrsets
These must be serialised to a JSON string of the *result* of coercing
the function application to a string.

Change-Id: Ib7f49ccd950503ddbdbf99643cd59565e26b50da
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8204
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
eef48b8f1f fix(tvix/eval): correctly thunk deferred formals access
Formals can be initialised with deferred default values (see the test
cases), in which case they need an extra thunk to have something that
can be finalised appropriately when the setup is done.

Fixes: b/255
Change-Id: I380e3770be68eaa83ace96d450c7cead32dacc9f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8196
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
83b2290e1b test(tvix/eval): add test for infinite recursion detection
Change-Id: Ief20544a44c3542fe40a5c09f81d0f064a346f44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8149
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
2023-03-13 20:30:59 +00:00
Vincent Ambo
025c67bf4d refactor(tvix/eval): flatten call stack of VM using generators
Warning: This is probably the biggest refactor in tvix-eval history,
so far.

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

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

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

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

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

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

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

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

   Notably, this includes *all* builtins.

This has had some other effects:

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

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

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

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

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

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

Fixes: b/238, b/237, b/251 and potentially others.
Change-Id: I39244163ff5bbecd169fe7b274df19262b515699
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8104
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2023-03-13 20:30:59 +00:00
Vincent Ambo
c98c5399b9 fix(tvix/eval): skip runtime completely on compiler errors
This branch was missing, and an assumption elsewhere just executed the
returned (broken) bytecode.

This fixes b/253.

Change-Id: I015023ba921bc08ea03882167f1f560feca25e50
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8090
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
2023-02-13 16:21:47 +00:00
Vincent Ambo
3419f63575 fix(tvix/eval): ensure all evaluated thunks are correctly memoized
This fixes a very complicated bug (b/246). Evaluation
progresses *much* further after this, leading to several less
complicated bugs likely being uncovered by this

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Change-Id: I738525bad8bc5ede5d8c737f023b14b8f4160612
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8012
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-02-03 10:47:18 +00:00
Vincent Ambo
7702941dd9 test(tvix/eval): add tests for internal formals dependencies
Formals can depend on each other when using another formal as a
default value.

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

Change-Id: Ibdabe262554e8066d67fac1ebc3b5a48ef626e18
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7948
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-31 10:25:02 +00:00
Florian Klink
e0b05c0fa6 feat(tvix/eval): implement builtins.fromTOML
This allows parsing TOML from Tvix. We can enable the eval-okay-fromTOML
testcase from nix_tests. It uses the `toml` crate, and the serde
integration it brings with it.

Change-Id: Ic6f95aacf2aeb890116629b409752deac49dd655
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7920
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-25 07:49:44 +00:00
Florian Klink
1facd889bb feat(tvix/eval): use lexical-core to format float
Apparently our naive implementation of float formatting, which simply
used {:.5}, and trimmed trailing "0" strings not sufficient.

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

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

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

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

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

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

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

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

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

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

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

Change-Id: Ie6fba5619e1d9fd7ce669a51594658b029057acc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7922
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-25 07:49:44 +00:00
Vincent Ambo
d2f1a290a4 fix(tvix/eval): force functors before applying them
call_value in the VM expects the callable to be forced when calling
it, which was not the case for functors.

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

Change-Id: Ia632367328f66fb2f26cb64ae464f8f3dc9c6d30
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7891
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-22 20:48:53 +00:00
Vincent Ambo
f12f938166 refactor(tvix/eval): directly return builtin tuples from macro
All invocations of the builtin macro had to previously filter through
the `builtin_tuple` function, but it's more sensible to directly
return these from the macro.

Change-Id: I45600ba84d56c9528d3e92570461c319eea595ce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7825
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-20 15:39:51 +00:00
Vincent Ambo
b9646ab40c feat(tvix/eval): add builtins to builtins
This is a somewhat terrifying hack that enables us to support
`builtins.builtins`, by running a "fake compilation" inside of a
suspended native thunk that can resolve the weak pointer to the
globals.

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

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

Change-Id: I67d0e93246dd5b279c960aeda00402031aa12af3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7748
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-17 10:38:06 +00:00
Vincent Ambo
d365b09226 feat(tvix/eval): implement builtins.toXML
Change-Id: I009efc53a8e98f0650ae660c4decd8216e8a06e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7835
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-16 13:43:14 +00:00
Vincent Ambo
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
Ryan Lahfa
805219a2fa feat(tvix/eval): implement serde::Deserialize for Value
Co-Authored-By: Vincent Ambo <tazjin@tvl.su>

Change-Id: Ib6f7d1f4f4faac36b44f5f75cccc57bf912cf606
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7626
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-10 09:53:21 +00:00
Vincent Ambo
a149a1ee06 fix(tvix/eval): fix typo'd function name in tests
Caught by sterni on cl/7783.

Change-Id: I15d57b893ef22538fdd7e809f3b92861dd2bc1af
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7789
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2023-01-07 14:48:42 +00:00
Vincent Ambo
6b6bd30772 refactor(tvix/eval): move mocked builtins.derivation to tests
This placeholder should not live in the main crate anymore as we will
be injecting the real one from outside of eval, but there are still
language tests that depend on a (simple, mockable) version of it.

Change-Id: I68ea169db15cbdbeed320930d3069e21e376c90d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7783
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2023-01-06 20:53:02 +00:00
Vincent Ambo
6a8541e35a feat(tvix/eval): implement initial compiler::optimiser module
This optimiser can rewrite some expressions into more efficient forms,
and warn users about those cases.

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

Change-Id: I7df561118cfbad281fc99523e859bc66e7a1adcb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7766
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-06 12:23:55 +00:00
sterni
b7090ec874 test(tvix/eval): add test for builtins parity
This will eventually force us to have a base builtins set in common with
C++ Nix, i.e. all 2.3 builtins except the controversial
builtins.valueSize.

Change-Id: I2c767f07d6a14711911658e87da9f18ede57a143
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7747
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-06 12:00:38 +00:00
sterni
9b8ba915c8 fix(tvix/eval): ' is allowed in nonfirst position in Nix identifiers
With this is_valid_nix_identifier should line up with the upstream lexer
definition:

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

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

    { "assert" = null; }

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

    { assert = null; }

– maybe should be considered to be a bug.

Change-Id: I0a4e1ccb5033a80f3767fb8d1c4bba08d303c5d8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7744
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
2023-01-04 12:36:28 +00:00
Vincent Ambo
3d238c350b refactor(tvix/eval): streamline construction of globals/builtins
Previously the construction of globals (a compiler-only concept) and
builtins (a (now) user-facing API) was intermingled between multiple
different modules, and kind of difficult to understand.

The complexity of this had grown in large part due to the
implementation of `builtins.import`, which required the notorious
"knot-tying" trick using Rc::new_cyclic (see cl/7097) for constructing
the set of globals.

As part of the new `Evaluation` API users should have the ability to
bring their own builtins, and control explicitly whether or not impure
builtins are available (regardless of whether they're compiled in or
not).

To streamline the construction and allow the new API features to work,
this commit restructures things by making these changes:

1. The `tvix_eval::builtins` module is now only responsible for
   exporting sets of builtins. It no longer has any knowledge of
   whether or not certain sets (e.g. only pure, or pure+impure) are
   enabled, and it has no control over which builtins are globally
   available (this is now handled in the compiler).

2. The compiler module is now responsible for both constructing the
   final attribute set of builtins from the set of builtins supplied
   by a user, as well as for populating its globals (that is
   identifiers which are available at the top-level scope).

3. The `Evaluation` API now carries a `builtins` field which is
   populated with the pure builtins by default, and can be extended by
   users.

4. The `import` feature has been moved into the compiler, as a
   special case. In general, builtins no longer have the ability to
   reference the "fix point" of the globals set.

This should not change any functionality, and in fact preserves minor
differences between Tvix/Nix that we already had (such as
`builtins.builtins` not existing).

Change-Id: Icdf5dd50eb81eb9260d89269d6e08b1e67811a2c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7738
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
2023-01-04 12:28:43 +00:00
Vincent Ambo
91465dc78e refactor(tvix/eval): persistent, memory-sharing OrdMap for NixAttrs
This uses the `im::OrdMap` for `NixAttrs` to enable sharing of memory
between different iterations of a map.

This slightly speeds up eval, but not significantly. Future work might
include benchmarking whether using a `HashMap` and only ordering in
cases where order is actually required would help.

This switches to a fork of `im` that fixes some bugs with its OrdMap
implementation.

Change-Id: I2f6a5ff471b6d508c1e8a98b13f889f49c0d9537
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7676
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-12-29 17:44:56 +00:00
Vincent Ambo
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
c3c4d752c9 feat(tvix/eval): add EvalIO to public crate API
This lets users set the `io_handle` field on an `Evaluation`, which is
then propagated to the VM.

Change-Id: I616d7140724fb2b4db47c2ebf95451d5303a487a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7566
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
2022-12-21 22:37:11 +00:00
Vincent Ambo
1138fbcaad refactor(tvix/eval): use new public API in test code
This removes internal uses of the previous crate::eval module, which
is being removed.

Change-Id: I5fb3c53460a9c5381853d0258f9ed074ab23c630
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7543
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
2022-12-21 13:09:28 +00:00
Vincent Ambo
3aca3d3bba refactor(tvix): build Rust projects using crate2nix
Introduces granular dependency builds using crate2nix, bootstrapped
off the generated configuration from the newly introduced
workspace (see cl/7533).

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

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

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

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

Change-Id: I2014614ccb9c8951aedbd71df7966ca191a13695
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7538
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
2022-12-15 17:26:45 +00:00
sterni
90fe9a51d7 test(tvix/eval): check inner forcing despite declaring pointer
Maybe counter-intuitively the inner elements of a list or the
attribute values of an attribute set will be forced despite
pointer equality (but only one layer deep).

Change-Id: I485d96452fb56f5fb342d39039c9137725b33d3f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7371
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2022-12-02 14:41:50 +00:00
Vincent Ambo
5ab86ab8dc test(tvix/eval): add a test for repeated keys in listToAttrs
This came up in the Nix Language channel today and I thought it
warranted a test case.

We did actually implement this correctly.

Change-Id: I4b37c92d06eb6e3a7f59ea3d10af38f2b0a93d53
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7493
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-12-02 14:39:34 +00:00
sterni
1ad777e3c7 test(tvix/eval): verify pointer equality checks
Change-Id: I9baf2810fbd5b6ee8bfe10fce5b64801a35c1d67
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7369
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
2022-12-02 14:06:35 +00:00
sterni
7bab0c26ee test(tvix/eval): verify pointer equality in list comparisons
Change-Id: I617d402c8ecc7aaf607c4bdcd58a06ebddb71fac
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7370
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: Adam Joseph <adam@westernsemico.com>
2022-12-02 14:06:22 +00:00
Adam Joseph
4b09f01571 fix(tvix/eval): OpAdd must weakly stringify if either arg is string
Tests included.

Change-Id: I7a4905d6103813373e383e2e8629c5fd243d6bca
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7377
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>
2022-11-26 19:37:42 +00:00
Adam Joseph
325a7d6fa9 test(tvix/eval): add eval-okay-closure-pointer-compare
This test case checks two things:

* A sanity check that "pointer equality for functions" means not
  just the lambda, but also the upvalues.

* To be pointer-equal, it is not enough for the upvalues to be
  normal-form equal (i.e. `nix_eq()`-equal); the upvalues must be
  *pointer*-equal.  The second part of the test case checks for
  this.

Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I4e59327a6f199b8212e97197b212e3c3934bb3f0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7372
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-11-25 00:48:31 +00:00
sterni
bc537d2c0d test(tvix/eval): test limits of builtins.seq's forcing
Change-Id: I6dfc9108220762ef3372cd2739e91d79c01a55e1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7366
Tested-by: BuildkiteCI
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2022-11-24 13:25:28 +00:00
Vincent Ambo
e1e8285ecf test(tvix/eval): enable eval-okay-closure test from nix_tests
This function covers builtins.genericClosure, seemingly including
weird behaviour around the order in which the work set is processed.

For some reason, in C++ Nix the test expectation is written in XML
which we do not yet support, so I have created a new expectation file
using `nix-instantiate --eval --strict` on the file (yes, using C++
Nix).

Change-Id: Id90e7117d120dc66d963a51083c4d8e8f2d9f181
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7311
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-11-21 14:14:49 +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
290a819018 feat(tvix/eval): placeholder builtin implementations
Adds initial placeholders for builtins.{derivation,
unsafeDiscardStringContext}.

Change-Id: I67a126c9b9f9f4f11e2256e69b9a32ebd9eb1b0e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7187
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-11-06 08:10:29 +00:00
Adam Joseph
a79c233ae6 feat(tvix/eval): implement builtins.split
This implements builtins.split, and passes eval-okay-regex-split.nix
(which is moved out of notyetpassing).

Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: Ieb0975da2058966c697ee0e2f5b3f26ccabfae57
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7143
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
2022-11-04 21:28:32 +00:00
Adam Joseph
9c7d8e791a test(tvix/eval): add a test case for groupBy with thunks
We have to be careful implementing `builtins.groupBy`, since the
list may contain thunks, and tvix's to_xxx() functions do not work
on thunks.

Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I182b6fc2d4296f864ed16744ef70b153e8e6978a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7039
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-11-04 01:46:27 +00:00
Adam Joseph
4ec43bed5e fix(tvix/eval): quote keys which are not valid identifiers
The impl Display for NixAttrs needs to wrap double quotes around any
keys which are not valid Nix identifiers.  This commit does that,
and adds a test (which fails prior to this commit and passes after
this commit).

Change-Id: Ie31ce91e8637cb27073f23f115db81feefdc6424
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7084
Autosubmit: Adam Joseph <adam@westernsemico.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
2022-11-04 01:42:25 +00:00