CL/6867 added support for builtins.import, which required a cyclic
reference import->globals->builtins->import. This was implemented
using a RefCell, which makes it possible to mutate the builtins
during evaluation. The commit message for CL/6867 expressed a
desire to eliminate this possibility:
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.
This CL replaces the RefCell with Rc::new_cyclic(), making the
globals/builtins immutable once again. At VM runtime (once opcodes
start executing) everything is the same as before this CL, except
that the Rc<RefCell<>> introduced by CL/6867 is turned into an
rc::Weak<>.
The function passed to Rc::new_cyclic works very similarly to
overlays in nixpkgs: a function takes its own result as an argument.
However instead of laziness "breaking the cycle", Rust's
Rc::new_cyclic() instead uses an rc::Weak. This is done to prevent
memory leaks rather than divergence.
This CL also resolves the following TODO from CL/6867:
// TODO: encapsulate this import weirdness in builtins
The main disadvantage of this CL is the fact that the VM now must
ensure that it holds a strong reference to the globals while a
program is executing; failure to do so will cause a panic when the
weak reference in the builtins is upgrade()d.
In theory it should be possible to create strong reference cycles
the same way Rc::new_cyclic() creates weak cycles, but these cycles
would cause a permanent memory leak -- without either an rc::Weak or
RefCell there is no way to break the cycle. At some point we will
have to implement some form of cycle collection; whatever library we
choose for that purpose is likely to provide an "immutable strong
reference cycle" primitive similar to Rc::new_cyclic(), and we
should be able to simply drop it in.
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I34bb5821628eb97e426bdb880b02e2097402adb7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7097
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
* //users/grfn/system/home/modules:
The MultiMC saga continues with:
> PolyMC has been removed from nixpkgs due to a hostile takeover
> by a rogue maintainer. The rest of the maintainers have made a
> fork which is packaged as 'prismlauncher'.
* //third_party/overlays:
Override tdlib to 1.8.7 while waiting for nixpkgs to catch up.
* //users/tazjin/finito:
Disable on CI temporarily as it has been broken by some change
in nixpkgs, now failing to compile a dependency.
Change-Id: Ide038a8d466bfdc19dc9016beb03ae4817939a2b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7066
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Instead of waiting for nixpkgs to [update home-manager], we can track
the upstream repository directly (using master as a channel seems to
be common practice) and overlay the up to date source into our nixpkgs
instance.
For //users/tazjin/home and //users/wpcarro/nixos/marcus, we need to
set `home.stateVersion`, since the default value for this option was
removed some time this summer.
[update home-manager]: https://github.com/NixOS/nixpkgs/issues/197907
Change-Id: I8c153fb7d3b55a4040652a5d619761b640119105
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7098
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
* add an explicit `tvix` node to track who arrived here through
Tvix-related means
* remove nodes that aren't actually relevant or informative for how
people got to TVL (e.g. `anon1` or `lgbtslack`).
* remove some people that have been missing for a long time and are
probably not coming back
Change-Id: I110180daa3c3c8f48593000b9e8d7cd4cf32b741
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7104
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: ezemtsov <eugene.zemtsov@gmail.com>
See blog post
Change-Id: I4b7dcdc85e5125876441b2f157e3d6ddc3cd3140
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7103
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Another note to Future Me
Change-Id: Icf2edbbc6118b2b689ff403c38e91a69089a27a2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7099
Reviewed-by: wpcarro <wpcarro@gmail.com>
Tested-by: BuildkiteCI
This adds a comment noting that StackIdx is an offset relative to
the base of the current CallFrame, whereas UpvalueIdx is an absolute
index into the upvalues array.
It also removes the confusing mention of StackIdx in the descriptive
comment for LocalIdx. They index into totally different structures;
one exists at runtime and the other exists at compile time.
Change-Id: Ib932b1b0679734c15001e8c5c95a08293fa016b4
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7017
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
This adds a function NixList::force_elements() which forces each
element of the list shallowly. This behavior is needed for
`builtins.replaceStrings`, and probably a few other builtins as
well.
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I3f0681acbbfe50e781b5f07b6a441647f5e6f8da
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7094
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Unfortunately we have to mangle test case filenames into rust-valid
symbols, since test-generator doesn't use `r#"..."` (deliberately?).
This means that when a test fails, there's nothing on the console
you can copy-and-paste in order to view/edit the code of the failing
test case.
This commit (partially) fixes it by including the unmangled name in
the panic!() string. However failures due to panic!()s inside the
vm (including deliberate panics due to panic!()-debugging) still
won't display an unmangled filename.
Maybe we should reconsider the use of test-generator?
Change-Id: I2208a859ffab1264f17f48fd303ff5e19675967e
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7092
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Support an array that dynamically resizes itself, and replace usages of `List`,
`Array`, and `Queue` with `Vec`.
Change-Id: I910b140b7c1bdddae40e08f8191986dccbc6fddf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7080
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
I've been wanting to grok Haskell-style type inference for awhile, so instead of
just watching conference talks and reading papers about it, I've decided to
attempt to implement it to more readily test my understanding of it.
Change-Id: I69261202a3d74d55c6e38763d7ddfec73c392465
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6988
Tested-by: BuildkiteCI
Reviewed-by: wpcarro <wpcarro@gmail.com>
Autosubmit: wpcarro <wpcarro@gmail.com>
Rather than implementing all of the interesting semantics of value
comparison with a macro bound to the VM, implement the bulk of the logic
with a method on Value itself that returns an Ordering, and then use the
macro to implement the comparison against that Ordering. This has no
functional change, but paves the way to implementing lexicographic
comparison of list values, which is supported in the latest version of
upstream nix.
Change-Id: I8af1a020b41577021af5939f5edc160c407d4a9e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7069
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
I played around a little bit with doing this in-place, but ended up
going with this perhaps slightly clone-heavy approach for now because
ideally most clones on Value are cheap - but later we should benchmark
alternate approaches that get to reuse allocations better if necessary
or possible.
Change-Id: If998eb2056cedefdf2fb480b0568ac8329ccfc44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7068
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
The last bump in langVersion (5->6) in C++ Nix was due to making lists
comparable (commit `09471d2680292af48b2788108de56a8da755d661`), which
we support in Tvix with cl/7070.
Change-Id: Id3beed5150b8fb6e0a46a4d1b7e3942022a65346
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7074
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
This commit implements builtins.currentSystem, by capturing the
cargo environment variable `TARGET` and exposing it to rustc as
`TVIX_CURRENT_SYSTEM` so it can be inserted into the source code
using `env!()`.
The resulting value needs to be massaged a bit, since it is an "LLVM
triple". The current code should work for all the platforms for
which cppnix works (thanks qyliss for generating the list!). It
does *not* reject all of the triples that cppnix's configure.ac
rejects -- it is much more forgiving. We can tighten this up in a
future commit.
Signed-off-by: Adam Joseph <adam@westernsemico.com>
Change-Id: I947f504b2af5a7fee8cf0cb301421d2fc9174ce1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6986
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Since we push arguments onto a stack when calling multi-argument
functions, we actually were ending up calling `call_with` with the
arguments in the *reverse order* - we patched around this by passing the
arguments in the reverse order for `foldl'`, but it makes more sense to
have them just be the order that the function would be called with in
user surface code instead.
Change-Id: Ifddb98f46970ac89872383709c3ce758dc965c65
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7067
Reviewed-by: sterni <sternenseemann@systemli.org>
Autosubmit: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
When compiling a lambda, take the name of the outer slot (if
available) and store it as the name on the lambda.
These names are then shown in the observer, and nowhere else (so far).
It is of course common for these things to thread through many
different context levels (e.g. `f = a: b: c: ...`), in this setup only
the outermost closure or thunk gains the name, but it's better than
nothing.
Change-Id: I681ba74e624f2b9e7a147144a27acf364fe6ccc7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7065
Reviewed-by: grfn <grfn@gws.fyi>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
There are some rare scope cases with deferred access where this
doesn't behave correctly otherwise.
Change-Id: I6c774f5e62c1cb50b598026c54727017a52cd22d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7064
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
The warning needs to consider whether it is occuring inside of a
thunk, i.e. the dynamic ancestry chain of lambda contexts must be
inspected and not just the current scope.
Change-Id: I5cf5482d67a8bbb9f03b0ecee7a62f58754f8e59
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7063
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
This check is now actually simply equivalent to checking whether the
target has been initialised or not.
Change-Id: I30660d11073ba313358f3a64234a90ed81abf74c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7062
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
These are builtins which can be basically implemented as the identity
function from the perspective of pure evaluation, and which help us
get closer to evaluating nixpkgs.
For now, builtins added here will be "usable" and just emit a warning
about not being implemented yet.
Change-Id: I0fce94677f01c98c0392aeefb7ab353c7dc7ec82
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7060
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Checking the computed depth and stack slot against the computed depth
and stack slot is equivalent to just checking the indices into the
locals vector against each other (i.e. "is the slot we're compiling
into the slot we're accessing?")
Change-Id: Ie85a68df073e3b2e3d9aba7fe8634c48eada81fc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7059
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
When capturing an upvalue, return a detailed TvixBug error that
contains metadata about what exactly was missing.
This particular thing helps with debugging some scope issues we still
seem to have.
Change-Id: I1089a1df4b3bbc63411a4907c3641a5dc3fad984
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7058
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Using the same method as in Thunk::deep_force, detect cycles when
printing values by maintaining a set of already seen thunks.
With this, display of infinite values matches that of Nix:
> nix-instantiate --eval --strict -E 'let as = { x = 123; y = as; }; in as'
{ x = 123; y = { x = 123; y = <CYCLE>; }; }
> tvix-eval -E 'let as = { x = 123; y = as; }; in as'
=> { x = 123; y = { x = 123; y = <CYCLE>; }; } :: set
Change-Id: I007b918d5131d82c28884e46e46ff365ef691aa8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7056
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
This can be raised in cases where some panics lurk (e.g. indexed
accesses).
Change-Id: I93f4d60568277e9c5635aa52f378645626d68c5e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7057
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Note that this test (ironically) fails if the observer is used (e.g.
with --trace-runtime), but that's a separate issue.
Change-Id: I952eaeac8b5a7acce9c66cd4744ec570280748e7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7055
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
This is done via a new `deepForce` function on Value. Since values can
be cyclical (for example, see the test-case), we need to do some extra
work to avoid RefCell borrow errors if we ever hit a graph cycle:
While deep-forcing values, we keep a set of thunks that we have
already seen and avoid doing any work on the same thunk twice. The set
is encapsulated in a separate type to stop potentially invalid
pointers from leaking out.
Finally, since deep_force is conceptually similar to
`VM::force_for_output` (but more suited to usage in eval since it
doesn't clone the values) this removes the latter, replacing it with
the former.
Co-Authored-By: Vincent Ambo <tazjin@tvl.su>
Change-Id: Iefddefcf09fae3b6a4d161a5873febcff54b9157
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7000
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
When forcing thunks in `force_with_output`, the call stack of the VM
is actually empty (as the calls are synthetic and no longer part of
the evaluation of the top-level expression).
This means that Tvix crashed when constructing error spans for the
`fallible` macro, as the assumption of there being an enclosing span
was violated.
To work around this, we instead pass the span for the whole top-level
expression to force_for_output and set this as the span for the
enclosing error chain. Existing output logic will already avoid
printing the entire expression as an error span.
This fixes b/213.
Change-Id: I93978e0deaf5bcb0f47a6fa95b3f5bebef5bad4c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7052
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
The version of buf used is quite old.
nixpkgs provides a more recent version, but it requires us to migrate
config to the latest version.
depot_scanner.proto doesn't honor some of the conventions, so we need
allow_comment_ignores and drop a bunch of comments in there.
Change-Id: Ic978fe92fb7c8471f58c137497528f18aad8f3ab
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7053
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: tazjin <tazjin@tvl.su>
Failures to resolve a nix search path lookup in angle brackets can be
caught using tryEval (if it reaches the runtime). Resolving relative
paths (either to the current directory or the current user's home) can
never be caught, even if they happen inside a thunk at runtime (which is
currently the case for home-relative paths).
Change-Id: I7f73221df66d82a381dd4063358906257826995a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7025
Autosubmit: sterni <sternenseemann@systemli.org>
Reviewed-by: Adam Joseph <adam@westernsemico.com>
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Turns out that pathContextDrvPath already exists as a builtin which
is very convenient. Actually somewhat embarassing that I missed this
for so long.
Change-Id: Ieb5e113d70dec548b3053911ff9dbe9ed48402be
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7050
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Adding these to the C++ Nix CI ensures that it is possible for the
tests in that directory to pass at all. Mainly this would catch
situations like fixed in a previous CL when moving the tests around
would break them so that they wouldn't even pass in C++ Nix.
For this to work, we need to track skips by basename to be
directory-independent (assuming that every skipped test name is unique
is hopefully okay).
Change-Id: If6cb63ebdef0fc19b082b6a04e79ada2e47c658e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7048
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
cl/7036 moved these paths around, but neglected to update the relative
paths they contain. Without these updated, they will never start
passing!
Change-Id: Ib16468611af59729883e501be8486f43d850fd58
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7046
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
eval-okay-eq.nix is actually an ancient test case that used the ATerm
syntax for the test result. It was disabled for a while, since the
behavior got reverted for a bit, but works on any reasonably modern
Nix implementation. This change matches my [C++ Nix PR].
[C++ Nix PR]: https://github.com/NixOS/nix/pull/7196
Change-Id: I602fd7c83a0bc104ab502c8b6a74e4591272be1a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7045
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
The language test suite actually doesn't require flakes and the
new features are mostly sensible (added builtins) as well as some
tests for regressions the C++ implementation experienced.
The path interpolation test is not included in this update because there
is no way to construct an location-independent .exp file for it (the C++
repo also doesn't have one). We may still want to implement that feature
eventually (in case rnix adds support for it).
The C++ Nix revision used is ac0fb38e8a5a25a84fa17704bd31b453211263eb.
Change-Id: I75f1e780ddeeee6f6b1f28cf3c66c288dca2c20c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/7043
Autosubmit: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
