This module contains the request/response types for generators
requesting actions from the VM.
For most of these, an async helper function is added that will be used
inside of generator functions to make use of these requests/responses
instead of constructing them directly.
Change-Id: I1e085f88adaf784a34867957a0e82532d3a83d7c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8148
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
As applies are thunked, there was no situation where OpCall could be
emitted. In practice, all calls were already tail calls.
Change-Id: Id0d441dcdd86f804d7cddd0cc14f589bbfc75e5b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8147
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Because they do not use it, and it can not be passed with the coming
generator refactoring.
Change-Id: I0d96f2357a7ee79cd8a0f401583d4286230d4a6b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8146
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Instead of using a suspended native thunk, calculate and optionally
insert the storeDir builtin when the VM is constructed.
We already have the IO handle available at this point and can just
check whether a storeDir is present, and insert its absolute value as
a builtin.
Change-Id: If966eee6ff26dc888b6e888e7c46170c0c346b05
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8145
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
This is a ThunkSet wrapped to be shareable, which will be required
once ThunkSets are embedded in futures.
Change-Id: I5a067b7972ac86e4d354c75ef05c86b2284c1137
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8144
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Again simplifying some code down the line, where bits of code that
construct attribute sets already have the final structure available.
Change-Id: I0bb7a1daa63298122b51be73d35d695a4f73f8b0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8140
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
This simplifies some code down the line.
Change-Id: I58dd71e796e11479f44516cf24932f8061843d23
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8139
Tested-by: BuildkiteCI
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
This adds addresses of thunk and closure chunks to the debug output
displayed when dumping bytecode.
This makes it possible to see in the dump which thunks are referenced
by constants in other thunks.
Change-Id: I2c98de5227e7cb415666cd3134c947a56979dc80
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8137
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
This CL removes redundant clone from value which is
going to be dropped without further use.
Change-Id: Ibd2a724853c5cfbf8ca40bf0b3adf0fab89b9be5
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8125
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
We want the address that the Rc is pointing to, not the address of the
Rc.
Change-Id: I8eba21677f242bbe4166c74d4aa4269c316076e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8045
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
This CL address clippy warning which expects to
use `writeln` instead of `write` for strings with
new line.
Change-Id: Ia72a07502c60cfd489ecf1e3833b9d42d44a8b17
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8030
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
This CL address clippy warning about finding the zero
length of something using `is_empty()` instead of `len() == 0`.
Change-Id: I2b36c7c7b65b733609fc0dcd33be06f9d772bc9b
Signed-off-by: Aaqa Ishtyaq <aaqaishtyaq@gmail.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8029
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
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>
These should be inspectable by callers.
Change-Id: Ia9ef871aa63958d06066aaea61b2aecbd217369b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8089
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Plain paths like `foo/bar.nix` are also allowed, so we can not
determine this based on the prefix.
The upstream PR that is referenced in a comment here has a
significantly different interface than we expected, so I'm not
touching that comment yet in this CL before I've had more time to
digest it.
Change-Id: Iea33bbb35de9c00a7d7fedf64d02253c75c1cc9e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8032
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: Alyssa Ross <hi@alyssa.is>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
We only use Rc in `impl EvalIO for StdIO`, which is only included when
building with the "impure" feature.
Change-Id: Id29d647c899cbfcdda11abfb9fabd5aa7e24299f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8025
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
This reduces the size of `Builtin` from 88 (!) bytes to 8, and as the
largest variant of `Value`, the size of that type from 96 to 64.
The next largest type is NixList, clocking in at 64 bytes.
This has noticeable performance impact. In an implementation without
disk I/O, evaluating nixpkgs.stdenv looks like this:
Benchmark 1: tvix -E '(import <nixpkgs> {}).stdenv.drvPath'
Time (mean ± σ): 1.151 s ± 0.003 s [User: 1.041 s, System: 0.109 s]
Range (min … max): 1.147 s … 1.155 s 10 runs
After this change, it looks like this:
Benchmark 1: tvix -E '(import <nixpkgs> {}).stdenv.drvPath'
Time (mean ± σ): 1.046 s ± 0.004 s [User: 0.954 s, System: 0.092 s]
Range (min … max): 1.041 s … 1.053 s 10 runs
Change-Id: I5ab7cc02a9a450c0227daf1f1f72966358311ebb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8027
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
When resolving a select expression (`attrs.name` or `attrs.name or
default`), if the set compiles to a constant attribute set (as is most
notably the case with `builtins`) we can backtrack and replace that
attribute set directly with the compiled value.
For something like `builtins.length`, this will directly emit an
`OpConstant` that leaves the `length` builtin on the stack.
Change-Id: I639654e065a06e8cfcbcacb528c6da7ec9e513ee
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7957
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
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>
... not just a TODO.
Most use-cases of unsafeDiscardStringContext are for cases where a
string is processed in some ways and no longer contains a "physical"
reference, but still has its context attached in C++ Nix.
We don't need to do this. This does diverge in behaviour in use-cases
related to build scheduling, but that whole behaviour will be
different in Tvix.
Change-Id: I4056d4c09f62d44d6bd52b791db03fe5556672b5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8016
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
... instead of a BTreeMap, as we do not need ordering guarantees here.
HashMaps are noticeably faster here (especially as we've been sorting
essentially random data!).
Change-Id: Ie92d74286df9f763c04c9b226ef1066ee8484c13
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8014
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
This adds a fake argument name to builtins.toXML which allows toXML to
serialise any value instead of panicking on functions. We do still
have to fix the value itself, eventually, though.
Change-Id: I2e330ecddcd80442b4fac5eced64431ac86123ba
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7962
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
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>
While it is in the given example, i.e. for integer addition, to claim
that they are equivalent is a bit misleading: builtins.add is less
overloaded than +, i.e. builtins.add "foo" "bar" will fail whereas
"foo" + "bar" performs string concatenation.
Change-Id: Ib52d530d1ab289b367565b286f06a76dd518d4fb
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7929
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
This keeps the actual TotalDisplay implementation readable, as this
float formatting code suddenly made up the majority of its implementation.
Change-Id: I2c0d00e4a691e0b8ffbc72680f680e16feef4bee
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7925
Reviewed-by: flokli <flokli@flokli.de>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
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
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>
Two main reasons:
1. Traversing the structure to do this optimisation is
actually *slower* than not optimising it.
2. There are literally hundreds of thousands of incidences of this in
nixpkgs, and with some of the weird code there some of
these (functionally) useless parens are actually required for
readability reasons.
Change-Id: I1044b1c5f9fe20df4b6085851fc3b191277c65dc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7917
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
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>
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>
While moving the CLI out of the evaluator, we forgot to update the
README in //tvix/eval. Move this up to //tvix, so people know where
to start.
Keep the instructions on how to build only `//tvix/eval` in `//tvix/
eval/README.md`.
Change-Id: Ie2755e8b5a0056225dbf3a0ee040f70f7f6a1f27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7887
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
The codebase contains a lot of complexity and odd roundabout
handling for shadowing globals. I'm pretty sure none of this is
necessary, and all of it disappears if you simply make the globals
part of the ordinary identifier resolution chain, with their own
scope up above the root scope. Then the ordinary shadowing routines
do the right thing, and no special cases or new terminology are
required.
This commit does that.
Note by tazjin: This commit was originally abandoned when Adam decided
not to take away reviewer bandwidth for this at the time (eval was
still in a much earlier stage). As we've recently done some
significant refactoring of globals initialisation this came up again,
and it seems we can easily cover the use-cases of the poison tracking
in other ways now, so I've rebased, updated and resurrected the CL.
Co-Authored-By: Vincent Ambo <tazjin@tvl.su>
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: Ib3309a47a7b31fa5bf10466bade0d876b76ae462
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7089
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
This forces users to pass the fully constructed set of globals to the
VM, making it harder to accidentally "lose" the set while weak
references to it still exist.
This doesn't modify any functionality, but is laying the foundation
for simplifying some of the builtins behaviour that has grown more
complex again.
Change-Id: I5120f97861c65dc46d90b8a4e2c92ad32cc53e03
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7877
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
This adds a feature to the `#[builtins]` macro which lets users
specify an additional state type to (optionally) thread through to
builtins when constructing them.
This makes it possible for builtins-macro users to pass external state
handles (specifically, in our case, known path tracking) into a set of
builtins.
Change-Id: I3ade20d333fc3ba90a80822cdfa5f87a9cfada75
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7840
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
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>
This makes it possible for users to add additional context to an
error, which will then be rendered as an additional secondary span in
the formatted error output.
We should strive to do this basically anywhere errors are raised that
can occur multiple times, *especially* during type casts. This was
triggered by me debugging a type cast error attached to a fairly
large-ish span (a builtin invocation).
Change-Id: I51be41fabee00cf04de973935daf34fe6424e76f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7849
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
Instead of having a representation of suspended native thunks that
involves constructing a fake code chunk, make these thunks a
first-class part of the internal thunk representation.
The previous code was not that simple to understand, and actually
contained a critical bug which could lead to Tvix crashes. This
version fixes the particular instance of that bug, but instead
uncovers another (b/238) which can still lead to Tvix crashes.
Fixes: b/237.
Change-Id: I771d03864084d63953bdbb518fec94487481f839
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7750
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
This is unnecessary, Rc already provides all the boxing we need.
Change-Id: I08cf0939c48da43f04c847526c7e5dae5336d528
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7749
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
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>
Instead of going through Vec/BTreeMap for generating our internal
types, use the proptest strategies from imbl.
The one thing I couldn't figure out in the previous implementation is
where the ranges/sizes of generated collections came from. The
strategies in proptest use different types (Range, with an unknown
default value, and SizeRange with 0..100). I've opted to specify
0..100 directly, but we can probably make it configurable.
Change-Id: I749bc4c703fe424099240cab822b1642e5216361
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7791
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
This variant is required for external builtins (which in our case
includes `derivation`) to thread through reasonable error messages.
This has some potential for improvement, but it's an improvement over
the status quo of panicking in the external builtins when no
appropriate error is available.
Change-Id: I7e4bdb0a156c7717092dde30aa4785192182dc66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7841
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
