Commit graph

416 commits

Author SHA1 Message Date
Vincent Ambo
d75b207a63 refactor(tvix/eval): introduce Upvalues struct in closures & thunks
This struct will be responsible for tracking upvalues (and is a
convenient place to introduce optimisations for reducing value clones)
instead of a plain value vector.

The main motivation for this is that the upvalues will have to capture
the `with`-stack fully and I want to avoid duplicating the logic for
this between the two capturing types.

Change-Id: I6654f8739fc2e04ca046e6667d4a015f51724e99
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6485
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:16:46 +00:00
Vincent Ambo
6c9abc1f68 fix(tvix/eval): use correct lambda address in observer
Instead of the reference to the Rc, print the address of the Rc
itself.

Change-Id: I4560598924db7d2864d5c4ae9af847aee2ea7eff
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6471
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:16:46 +00:00
Vincent Ambo
fd14eefed6 fix(tvix/eval): correctly account for slots during list construction
Similarly to attribute sets, list elements can be arbitrary
expressions and their (temporary) stack slots during construction must
be accounted for by the compiler.

Change-Id: I3b6f7927860627fd867c64d0cab9104fd636d4f5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6470
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:16:46 +00:00
Vincent Ambo
33059de431 refactor(tvix/eval): cut down one iteration over locals array
Caught by sterni in cl/6339

Change-Id: I2f2cd746114f14854cf599a7223a42a3e8ebe4fc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6469
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:04:27 +00:00
Vincent Ambo
f68c76d07d fix(tvix/eval): account for attrset temporaries during construction
The temporaries left on the stack as operands to `OpAttrs` must be
accounted for in the locals array in order for operations within them
to receive correct slots.

Some test cases that were previously broken have been added.

Change-Id: Ib52b629bbdf7931f63fd45a45af1073022da923c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6468
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:04:27 +00:00
Vincent Ambo
12acb1e237 refactor(tvix/eval): add initialised arg to declare_phantom
There are more upcomming uses of declare_phantom where this will come
in handy to avoid some code bloat.

Change-Id: I75cad8caf14511c519ab2f56e87e99bcbf0a082e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6467
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:04:27 +00:00
Vincent Ambo
9da99af860 refactor(tvix/eval): encapsulate scope cleanup logic in module
Moves the logic for removing tracked locals from a given scope from
the compiler's locals list, and leaves only the actual
compiler-related stuff (emitting warnings, cleaning up locals at
runtime) in the compiler itself.

Change-Id: I9da6eb54967f0a7775f624d602fe11be4c7ed5c4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6466
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:04:27 +00:00
Vincent Ambo
27e69503a7 fix(tvix/eval): avoid forcing with-target until absolutely necessary
Change-Id: I00efbbb8b9d3d22f32becf0919c6adf1be8b4b69
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6465
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:04:27 +00:00
Vincent Ambo
bb34665abd refactor(tvix/eval): extract attribute set inherit into helper
This will be re-used between the code paths for
recursive/non-recursive sets, and it might even be possible to unify
it with the logic for compiling `let inherit ...`.

Change-Id: I960a061048ac583a6e932e11ff6e642d9fc3093e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6464
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:04:27 +00:00
Vincent Ambo
f86327beac feat(tvix/eval): implement "formals" function parameters
The comment explains how this works fairly well.

Note that this does not yet have the ability to check "closed
formals", i.e. without an ellipsis Tvix will *NOT* fail if unexpected
attribute set keys are provided.

Change-Id: I0d2b77e893243093d2789baa57f876d35d0a32ff
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6463
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-11 10:32:10 +00:00
Vincent Ambo
8643620eb1 fix(tvix/eval): always add history entries in REPL
... even if the code is broken.

Change-Id: I5898bceaebf201b97e8988c94c90e7fafff82529
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6462
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
4e06e5d2ba fix(tvix/eval): reintroduce 'InvalidAttribuetName' error variant
As pointed out by sterni in cl/6205, this is actually possible in
syntactically valid expressions like

  { ${12 + 13} = 12; }

Change-Id: Id8a1e3aceb551f288f9050c4eea563eb6572f1a7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6461
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
06909f1821 fix(tvix/eval): fix doc comment syntax where applicable
As pointed out by grfn on cl/6091

Change-Id: I28308577b7cf99dffb4a4fd3cc8783eb9ab4d0d6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6460
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
83dd706a3a feat(tvix/eval): conditionally use tracing/disassembling observers
Gates the observes behind the envvars `TVIX_DUMP_BYTECODE` and
`TVIX_TRACE_RUNTIME`.

(hi grfn, yes, we should probably introduce CLI flags soon)

Change-Id: I4fa194a84b04593d609b96b44471c3644fb30296
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6459
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
6bbe7589c5 feat(tvix/eval): optimise tail calls in emitted chunks
When the last instruction in a chunk is OpCall, make it an OpTailCall instead.

Change-Id: I2c80a06ee85e4abf545887b1a79b6d8b5e6123e9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6458
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
2e018a50a7 feat(tvix/eval): implement OpTailCall
If the last operation within a chunk is a function call, the call can
be executed in the same call frame without increasing the depth of the
call stack.

To enable this, a new OpTailCall instruction (similar to OpCall) is
introduced, but not yet emitted by the compiler.

Change-Id: I9ffbd7da6d2d6a8ec7a724646435dc6ee89712f2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6457
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-10 21:57:13 +00:00
Vincent Ambo
6deaa0d6ce fix(tvix/eval): force value passed to builtins.toString
This introduces a macro to do the forcing, but this solution isn't
very nice and also does not work in all cases yet.

Change-Id: Icd18862ec47edb82c0efc3af5835a6cb6126f629
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6456
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:14:56 +00:00
Vincent Ambo
0aeca64777 chore(tvix/eval): clean up a stale comment
Change-Id: If1b02fe1c78398387ea98490e5b099f1ff1b4164
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6455
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:14:56 +00:00
Vincent Ambo
e2a942e4b2 chore(tvix/eval): clean up remains of previous disassembler impl
Change-Id: Ib402ea23a58dc52ed0c5a97178cb5d0e53d69300
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6454
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:14:56 +00:00
Vincent Ambo
e03a729fa3 feat(tvix/eval): implement TracingObserver for runtime tracing
This produces similar output to the previous tracing feature, but can
redirect the output somewhere else.

Change-Id: I9493c260f480904f3932cb74809b622c24d7be96
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6453
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:14:56 +00:00
Vincent Ambo
14ff889d60 feat(tvix/eval): implement runtime tracing methods for Observer
These methods make it possible to trace the runtime execution of the
VM through an observer.

Change-Id: I90e26853ba2fe44748613e7f761ed5c1c5fc9ff7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6452
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:10:10 +00:00
Vincent Ambo
cbf2d2d292 refactor(tvix/eval): move disassemble_op to the Chunk structure
Change-Id: Ic6710c609ed647bfa47d673aaf22c4da96c0f319
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6451
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:10:10 +00:00
Vincent Ambo
3cf5c40209 chore(tvix/eval): export some symbols from the crate
These are required for tvixbolt to work. This interface is definitely
not stable yet, though.

Change-Id: I4076498e8f42311de74ee4f33c93a3ee0c5f8d3a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6450
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:10:10 +00:00
Vincent Ambo
8ee4d6d5db feat(tvix/eval): implement DisassemblingObserver for compiler
This type implements an observer that is called whenever the compiler
emits a chunk (after the toplevel, thunks, or lambdas) and prints the
output of the disassembler to its internal writer.

This replaces half of the uses of the `disassembler` feature, which
has been removed from the Cargo configuration.

Note that at this commit runtime tracing is not yet implemented as an
observer.

Change-Id: I7894ca1ba445761aba4ad51d98e4a7b6445f1aea
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6449
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:10:10 +00:00
Vincent Ambo
7ae45342df feat(tvix/eval): implement (compilation) observer trait
This trait will enable library users of tvix-eval to observe internal
happenings of the compilation and runtime processes.

The initial methods of the observer will be called whenever the
compiler emits a chunk.

Change-Id: I668f6c2cfe3d6f4c1a1612c0f293831011768437
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6448
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:10:10 +00:00
Vincent Ambo
1fe6cfe5a2 refactor(tvix/eval): index into Chunk with ConstantIdx/CodeIdx
This is a step towards hiding the internal fields of thunk, and making
the interface of the type more predictable.

Part of the preparation for implementing observers.

Change-Id: I1a88a96419c72eb9e2332b56a2dd94afa47e6f88
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6447
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-09 21:10:10 +00:00
Vincent Ambo
8c64ebe074 chore(tvix/eval): gate REPL-only dependencies behind repl feature
With this change, it becomes possible to compile tvix-eval to
webassembly if the `repl` feature is disabled.

Change-Id: Icc0a059964cd0bea2054110c682d50fc5c87ec01
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6446
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-09 10:48:10 +00:00
Vincent Ambo
8fdb67847c chore(tvix/eval): debug_assert that all jumps are patched
Suggestion from sterni in cl/6282

Change-Id: I1adbdda9ff74f55a2f72892ffa524808b305f403
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6445
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-09 10:48:10 +00:00
Vincent Ambo
abdfa7459e feat(tvix/eval): thunk binary operations and select expressions
With this, most cases of `fix` in attribute sets will work correctly.
A simple test exercising both has been added.

Change-Id: I70fd431177bb6e48ecb33a87518b050c4c3d1c09
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6437
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
9f379ef6df fix(tvix/eval): hold thunk borrow as shortly as possible
At the point where control flow exits Thunk::force (which may be due
to recursing), it is vital that there is no longer a borrow to the
inner thunk representation, otherwise this can cause accidental
infinite recursion (which will be detected, but cause failures on
valid code).

Change-Id: I2846f3142830ae3110a4f5d2299e9d7928634504
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6436
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
48d5f4fd57 feat(tvix/eval): print lambda memory adresses in disassembler
This makes it easier to track exactly which lambda is which when
inspecting e.g. the concrete representation of a thunk.

At runtime all lambdas live in an Rc. To make this print the right
address, the construction of these Rcs had to be moved up right to the
point where the lambda is first emitted (and disassembled).

Change-Id: I6070e6c8ac55f0bd697966c4e7c5565c20d19106
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6435
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
d3421c1cb9 fix(tvix/eval): ensure disassembler prints continous lines correctly
There can be different spans on the same line, so the previous
implementation would duplicate line numbers unnecessarily.

Change-Id: I8d8db77177aee0d834a6ec3584641e1bd5f31c3e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6434
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
fc1c50498e feat(tvix/eval): thunk function applications
Change-Id: I18065ed234ec104ac74d0e1c2d0937c2d78ca7db
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6433
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
e129ce15d7 feat(tvix/eval): thunk creation of lists
Change-Id: I84b68c5d002ec613d278315bbf49e9839f0fe8e8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6432
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
678533bfc4 test(tvix/eval): add test for stack slot accounting edge-case
This was fixed by some of the previous commits around scopes. It's
somewhat similar to a few other tests, but I had this one failing
earlier and everything else succeeding, so it is useful to keep it
around for sure.

Change-Id: Ie6cf372b5c805daf992cd87aeb3dfe91542c381c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6431
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
09eaa0d4ae fix(tvix/eval): address current clippy & grfn lints
Change-Id: I65c6feb9f817b5b367d37204a1f57acfe4100d97
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6430
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
fe047885d7 fix(tvix/eval): consider local depth when deciding to defer
Deferred local upvalues can *only* occur at the same depth as the
thing that is closing over them, but there are various situations with
scope nesting where the actual stack indexes of the local and the
closer look like a deferred value is being accessed.

To fix this, simply compare the depth as well.

Change-Id: Ice77424cc87ab0a2c4f01379e68d4399a917b12b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6429
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 20:17:26 +00:00
Vincent Ambo
360c805efc chore(tvix/eval): remove accidentally duplicated test
This is the same as `eval-okay-attrs-simple-inherit`.

Change-Id: I23878accc6cd62c16ec96601239838a385d31306
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6428
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 19:54:02 +00:00
Vincent Ambo
0af1df4be2 refactor(tvix/eval): clean up logic in Compiler::end_scope
The condition here was extremely hard to read prior to this change.

As the locals vector is now guaranteed to never be empty (there is
always at least a phantom for the current chunk's root expression),
the logic here can be simplified to just dropping tailing locals
entries while their depth matches that of the scope being closed.

Change-Id: I24973e23bc2ad25e62ece64ab4d8624e6e274c16
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6427
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 19:54:02 +00:00
Vincent Ambo
23f248b530 fix(tvix/eval): set up root stack slot in closures & thunks
Similar to setting up a phantom slot when compiling the root value of
a file, closures and thunks need to have a phantom stack slot for the
root of the expression yielded by their thunk to make all accounting
work correctly.

The tricky thing here is that closures & thunks *escape* their inner
lambda context (that's the point!), so the functions emitting them
need to know both the *inner* slot (to resolve everything correctly
while compiling the slot) and the *outer* slot (to correctly emit
instructions for closing over upvalues).

Change-Id: I62ac58e2f639c4b9e09cc702bdbfd2373e985d7f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6426
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 19:54:02 +00:00
Vincent Ambo
4e24bd56b4 fix(tvix/eval): only pop initialised locals when closing scopes
This avoids emitting OpPop instructions for locals that only existed
virtually (as uninitialised phantoms).

Change-Id: I8105afcca80c3f7b7ef93ce5e2f0d08a93f4ad27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6425
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 19:54:02 +00:00
Vincent Ambo
ecbd7c6ca1 fix(tvix/eval): ensure that root stack slot actually exists
Instead of using a sentinel LocalIdx which potentially points to a
value in the locals stack that does not actually exist, set up an
initial uninitialised phantom value representing the result of the
root expression.

Change-Id: I82ea774daab83168020a3850bed57d35ab25c7df
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6424
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 19:54:02 +00:00
Vincent Ambo
f8575fcd74 fix(tvix/eval): compare *stack* slots when deciding whether to defer
When deciding whether an upvalue needs to have a deferred resolution
step, the *stack* indexes should be compared - not the locals indexes.

The results are almost always the same, but there are tricky
situations where this can cause errors.

It's difficult to reproduce these errors in isolation, as they depend
on other scope behaviour, so this is one in a series of commits to
address the combination of issues which will gain some tests at the
end.

Change-Id: Iaa400b8d9500af58f493ab10e4f95022f3b5dd21
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6423
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 19:54:02 +00:00
Vincent Ambo
e9b6ecb0ee fix(tvix/eval): propagate scope depth when nesting scopes
Change-Id: Id441646db550f6195c2e247a0afbb5c9d91da8a0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6422
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 13:36:26 +00:00
Vincent Ambo
9973ddfcba refactor(tvix/eval): refactor locals to use an enum for phantoms
Instead of using sentinel values and an additional bool, this tracks
the identifier of a local as an enum that is either a statically known
name, or a phantom.

To make this work correctly some more locals related logic has been
encapsulated in the `scope` module, which is a good thing (that's the
goal).

Phantom values are now not initialised by default, but the only
current call site of phantoms (`with` expression compilation) performs
the initialisation right away.

This commit changes no actual functionality right now, but paves the
way for fixing an issue related to `let` bodies.

Change-Id: I679f93a59a4daeacfe40f4012263cfb7bc05034e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6421
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 13:36:26 +00:00
Vincent Ambo
7bc6e5984d refactor(tvix/eval): always pass slot to compiler methods
The slot is now always known (at the root of the file it is simply
stack slot 0 once the scope drops back down to 0), so it does not need
to be wrapped in an `Option` and accessed in cumbersome ways anymore.

Change-Id: I46bf67a4cf5cb96e4874dffd0e3fb07c551d44f0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6420
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 13:36:26 +00:00
Vincent Ambo
a303ea3ff5 refactor(tvix/eval): implement much clearer disassembler output
With this change the runtime trace contains much more exact
information about the context of the computation (entering/exiting
calls etc.)

This is in large part due to moving the tracer to be a field on the VM
itself, which enables consistent ordering of traces across the
execution, and tracing an execution with its *input* instead
of *output* stack.

Change-Id: Ibe525e6e7d869756501e52bef1a441619ce7332c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6419
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 13:36:26 +00:00
Vincent Ambo
60ff8d046c chore(tvix/eval): print value when panicking on internals
This makes it much easier to figure out what happened while debugging
this sort of thing.

Change-Id: I2e0e8096709adc647d63c04f213c547c415e5f44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6418
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 13:36:26 +00:00
Vincent Ambo
b83723a1ed fix(tvix/eval): force argument of builtins.length
Change-Id: Iaf94dfc7cb058f5c1c311066d92e01512e09cf71
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6417
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 12:53:20 +00:00
Vincent Ambo
0c0ae50f02 fix(tvix/eval): don't panic when printing a black hole
This could occur when the disassembler is enabled and tracing the
runtime while a thunk is being evaluated, as it would not be possible
for the *tracer* to borrow the thunk at this exact moment.

However, we know that if the borrowing fails here we are dealing with
a not-fully evaluated thunk (blackhole), which should just print the
internal representation.

Change-Id: I4bdb4f17818d55795368e3d28842048f488f0a91
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6416
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 12:53:20 +00:00
Vincent Ambo
2246a31e72 refactor(tvix/eval): return call frame result from VM::call
Previously, "calling" (setting up the VM run loop for executing a call
frame) and "running" (running this loop to completion) were separate
operations.

This was basically an attempt to avoid nesting `VM::run` invocations.
However, doing things this way introduced some tricky bugs for exiting
out of the call frames of thunks vs. builtins & closures.

For now, we unify the two operations and always return the value to
the caller directly. For now this makes calls a little less effective,
but it gives us a chance to nail down some other strange behaviours
and then re-optimise this afterwards.

To make sure we tackle this again further down I've added it to the
list of known possible optimisations.

Change-Id: I96828ab6a628136e0bac1bf03555faa4e6b74ece
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6415
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 12:53:20 +00:00
Vincent Ambo
cc526a2c87 feat(tvix/eval): thread codemap through to disassembler
If the disassembler feature is enabled, make sure that an Rc of the
codemap is available through the chunk.

Change-Id: I700f27ab665a704f73457b19bd2d7efc93828a16
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6414
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 12:53:08 +00:00
Vincent Ambo
a3b19ad8be docs(tvix/eval): add notes for builtins access optimisation
Change-Id: Iadbfbe2864ae42fe5492ef3ede0925baee4872b2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6413
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 08:45:15 +00:00
Vincent Ambo
6b3c3c9826 refactor(tvix/eval): add macros for generating Value casters
The casting methods of `Value` are pretty verbose, and actually
incorrect before this commit as they did not account for inner thunk
values.

To address this, we first attempt to make them correct by introducing
a standard macro to generate them and traverse the inner thunk(s) if
necessary.

This is likely to be a performance hit as it will now involve more
cloning of values. We can do multiple things to alleviate this, but
should do some measurements first.

Change-Id: If315d6e2afe7b69db727df535bc6cbfb89a691aa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6412
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 08:45:15 +00:00
Vincent Ambo
0d7ad5e6d1 refactor(tvix/eval): pass a VM reference to builtins
This makes it possible for builtins to force values on their own,
without the VM having to apply a strictness mask to the arguments
first.

Change-Id: Ib49a94e56ca2a8d515c39647381ab55a727766e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6411
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 07:59:15 +00:00
Vincent Ambo
5ee89bcf5c fix(tvix/eval): inherit scope poisoning data in nested contexts
Scope poisoning must be inherited across lambda context boundaries,
e.g. if an outer scope has a poisoned `null`, any lambdas defined on
the same level must reference that poisoned identifier correctly.

Change-Id: I1aac64e1c048a6f3bacadb6d78ed295fa439e8b4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6410
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 07:59:15 +00:00
Vincent Ambo
0a13d267f0 fix(tvix/eval): thread thunk forcing errors through correctly
With this, if an error occurs while forcing a thunk (which is very
likely) it is threaded through to the top by wrapping it in the
ErrorKind::ThunkForce variant.

We could use this to generate "stacktrace-like" error output if we
wanted, or simply jump through and discard everything except the
innermost error.

Change-Id: I3c1c8708c2f73ae062815adf490ce935b1979da8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6409
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 07:59:15 +00:00
Vincent Ambo
377ba19d75 feat(tvix/eval): ensure all errors always carry a span
Previously error spans were optional because the information about
code spans was not available at runtime. Now that this information has
been added, the error type will always carry a span.

This change is very invasive all throughout the codebase. This is due
to the fact that many functions that are called *by* the VM expected
to return `EvalResult`, but this no longer works as the span
information is not available to those functions - only to the VM
itself.

To work around this the majority of these functions have been changed
to return `Result<T, ErrorKind>` instead and an accompanying macro in
the VM constructs the "real" error.

Note that this implementatino currently has a bug where errors
occuring within thunks will yield the location at which the thunk was
forced, not the location at which the error occured within the code.
This will be fixed soon, but the commit is large enough as is.

Change-Id: Ib1ecb81a4d09d464a95ea7ea9e589f3bd08d5202
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6408
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-08 07:59:15 +00:00
William Carroll
197fe37dae feat(tvix/eval): Support builtins.length
Get the length of a list

Change-Id: I41d91e96d833269541a1b3c23b7cc879f96d1e5a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6407
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 20:56:02 +00:00
William Carroll
15e2bc54f1 feat(tvix/eval): Support builtins.{mul,div}
Multiplication and division :)

Change-Id: I79e76f3b55b7e9b8d1eb09b3d9741140b4d75742
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6406
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 20:56:02 +00:00
William Carroll
b3097de75d feat(tvix/eval): Support builtins.{add,sub}
First pass at supporting `builtins` for tvix. The following tests appear to be
WAI:

```shell
$ cd tvix/eval
$ cargo build
$ cargo test
```

Change-Id: I27cce23d503b17a886d1109e285e8b4be4264977
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6405
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 20:56:02 +00:00
Vincent Ambo
55d21a1389 refactor(tvix/eval): store spans instead of nodes in Warning/Error
Another step towards being able to report accurate errors. The codemap
spans contain strictly more accessible information, as they now retain
information about which input file something came from.

This required some shuffling around in the compiler to thread all the
right information to the right places.

Change-Id: I18ccfb20f07b0c33e1c4f51ca00cd09f7b2d19c6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6404
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:26 +00:00
Vincent Ambo
8033300900 feat(tvix/eval): track source spans for builtin access
As of this commit, the source spans of all emitted bytecode are fully
tracked.

Change-Id: I4c83deee0fc3f5e6fd6acad5a39047aec693b388
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6403
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
6cbd580ba5 feat(tvix/eval): track source spans for OpForce instructions
These source spans will always point to the *value* that is being
forced, not the instruction that caused the force to be emitted. This
makes sense so that errors during forcing point at the value and not
the surrounding expression.

Change-Id: I4694414a3281a0de878f71634105b92148ec61f6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6402
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
1ea88fcb65 feat(tvix/eval): track source spans for scopes
Change-Id: Iaedb0742940e4c2b9f4210579ed28e6deb32d5c8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6401
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
c269b44f41 feat(tvix/eval): track source spans for upvalues
With this change, the upvalue data instructions used by finalisers for
thunks and closures track the source span of the first identifier that
created the upvalue (if the same value is closed over multiple times
the upvalue will be reused, hence only the first one).

To do this the upvalue struct used by the compiler's scope now carries
an identifier node, which had to be threaded through quite a few
places.

Change-Id: I15a5fcb4c8abbd48544a2325f297a5ad14ec06ae
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6400
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
3efed26940 refactor(tvix/eval): split out Upvalue struct & UpvalueKind enum
This separation makes it possible to annotate the upvalue itself with
the span that created it, which (due to upvalue reuse) is only the
first one for an instance of the given UpvalueKind.

Change-Id: I9a991da6a3e8d71a92f981314bed900bcf434d44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6399
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
b8874f8d35 feat(tvix/eval): track source spans for thunks
Change-Id: I73f13c914d84e052a43b4eddb09db1acd8a7076a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6398
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
ec8ff79aee feat(tvix/eval): track source spans for function calls
Change-Id: If1bb463026414597acd561dc2032549fdb70f986
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6397
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
e590b585e7 feat(tvix/eval): track source spans for lambdas
Change-Id: I2f420fc915b6bfc5b197e9d0c128b539c4bc7467
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6396
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
20996601ea feat(tvix/eval): track source spans for with expressions
Change-Id: I1d58ce548b5b47e967928e85bb64acf5ed69ecc8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6395
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 20:04:17 +00:00
Vincent Ambo
9f5f85a1c1 feat(tvix/eval): track source spans for identifier access
Change-Id: I8e6ec0a84430d6e417fc7fd3e722a588913e4d18
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6394
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 19:23:22 +00:00
Vincent Ambo
f37e4a0b9c feat(tvix/eval): track source spans for let bindings
Change-Id: I9457917277a7fdd8bdbe227a567b28969312d06e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6393
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 19:23:22 +00:00
Vincent Ambo
7f687f0e99 feat(tvix/eval): track source spans for if expressions
These are again a bit tricky in terms of emitted errors. The main
error is that the condition is not a boolean, which means that the
jump inspecting the condition must derive from the condition itself to
return an error at the correct position.

For other parts of the expression, it is simply the node itself.

Change-Id: I72411630e5d57dfc199f4c3c48afe443fe966322
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6392
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
baa012d5a3 feat(tvix/eval): track source spans for assert
Change-Id: I5415f63ddde388847a261da4ce9a8d8235657535
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6391
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
805c1870ee feat(tvix/eval): track source spans for or operator
This one is tricky, specifically the span used for the final jump. I
decided that it makes sense to use the attrpath node, as the final
jump is the one that jumps *over* the default value, so the effect of
this is more closely related to the selector than the default.

It might be more correct to pass through the `or` token itself and
point to this for the jumps, but it depends a bit on what shape of
errors we could end up producing from this.

Change-Id: I29fbc97ba6b9e14e1a0e5f3a7759ddc299dd9c0c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6390
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
2b1468dde3 feat(tvix/eval): track source spans for attribute selects
Change-Id: Ifa8b0e7905f9d2746f83d6503ef0e8d42ce20f9c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6389
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
d1e0c6f680 feat(tvix/eval): track source spans for attrsets
Change-Id: I0fcb07146b5a38c67bc46ed3f67533b056858390
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6388
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
eb169c51a7 feat(tvix/eval): track source spans for lists
Change-Id: Icfd057ee29180cac17264bb3299c67eae0051aee
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6387
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
d8f494b50b feat(tvix/eval): track source spans for literal identifiers
Change-Id: I7ca08c6c0124f653e55fcc86413a847f0a4c50c5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6386
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
2ad89a00fb feat(tvix/eval): track source spans for ? operator
Change-Id: Idb842fb20fab14150455a81ea6c947e75b314d8a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6385
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
c417a084cc feat(tvix/eval): track source spans for binary operators
Change-Id: I43e433ff3094232b244d38335d31e56a79ca70c1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6384
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
176e729556 feat(tvix/eval): track source spans for unary operators
Change-Id: I79034a4aa04aea66ec598e33e6eab35e1e19c0d0
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6383
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
f14b368514 feat(tvix/eval): track source spans for strings
Change-Id: I29e6c7f9e25d1b2e6bafa602c463eb9ccee2131b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6382
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
3c4eed9b76 feat(tvix/eval): track source spans for paths
Change-Id: I42fbd0bb6c2a8feb520e262a25f59ff27dcd035c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6381
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
eaf7af18be feat(tvix/eval): track source spans for literals
Change-Id: Icfe77f85c4f65b6bf28b8752c2795419e8e396ce
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6380
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
72adcdf965 feat(tvix/eval): add methods for emitting code with tracked spans
These are not actually used yet; this is in preparation for a
multi-commit chain for emitting all the right spans in the right
locations.

Change-Id: Ie99d6add2696c1cc0acb9ab928917a10237159de
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6379
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:23:22 +00:00
Vincent Ambo
c5a8b93eaf chore(tvix/eval): thread a codemap::File reference to the compiler
This instantiates a codemap outside of the compiler and passes a
reference to the file currently under compilation to it. Note that the
"file" might just be a REPL line.

Change-Id: I131ae1ddb6d718e1374750da9ba0b99608c6058d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6378
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:10:40 +00:00
Vincent Ambo
b9566da5c9 refactor(tvix/eval): add and use Compiler::push_op method
This is currently just a wrapper around Chunk::push_op, but will gain
the span resolution logic in a moment.

Change-Id: I862bf9ecff0932f8da6708401ea044b9442c5d5b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6377
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:08:56 +00:00
Vincent Ambo
6f6bbc12f8 feat(tvix/eval): add data structures for tracking spans in chunks
This adds a new vector to the chunk data structure which tracks spans
into a codemap. The compiler will emit this information to the chunk
when adding instructions.

The internal representation of the spans is slightly optimised to
avoid storing duplicate spans, as there are cases where many
instructions might be derived from the same span.

Change-Id: I336f8c912e7eb50ea02ed71e6164f651ca3ca790
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6376
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:08:56 +00:00
Vincent Ambo
18f8fecba4 chore(tvix/eval): bump all dependencies
Updated the rnix hash manually, and ran `cargo update` for the rest.

Change-Id: I457262625d648e25d745efa4d33ae44cb8f21326
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6375
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:08:56 +00:00
Vincent Ambo
39e960daa6 chore(tvix/eval): add codemap dependency
This will be used to track source spans when emitting bytecode.

The codemap is a data structure which tracks *all* the source files
visited by an evaluation, and makes it possible to represent locations
across all of the files using a simple span (i.e. pair of offsets).

When reporting errors, this even contains enough information to
reconstruct the rnix AST to create fancier reporting in certain cases
if desired.

Change-Id: I4ae98620b9b150fb5a389bd7f1e12670e3192c62
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6374
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 19:08:56 +00:00
Vincent Ambo
f8919dbcd6 fix(tvix/eval): address current clippy lints
Note that I've allowed `needless_lifetimes` for the attribute set
iterator, as I find the type easier to understand with these
annotations present.

Change-Id: I33abb17837ee4813076cdb9a87f54bac4a37044e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6373
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 19:08:56 +00:00
Vincent Ambo
afcfa78364 feat(tvix/eval): semi-strictly evaluate output values of the VM
This essentially makes the VM behave like `nix-instantiate --eval
--strict`, i.e. data structures are traversed strictly and thunks are
forced. Thunks embedded in closures are not forced.

This allows us to re-enable tests that were disabled because they
needed to output nested thunk contents, but is overall a behaviour
that must be configurable later on, as it is not cmopatible with e.g.
an evaluation of nixpkgs.

Change-Id: I5303a5c8e4322feab1384fdb7712fecb950afca5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6372
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 19:08:56 +00:00
Vincent Ambo
6c6f9ae661 feat(tvix/eval): implement NixList::iter
This does not require a custom iterator type (for now?)

Change-Id: I5beb194bd8629571bd4040c69c977c27149807fa
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6371
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 19:08:56 +00:00
Vincent Ambo
fea7f90a7f fix(tvix/eval): thread Display & PartialEq through to thunk values
If a thunk is already evaluated, there are cases where due to the
memoisation implementation something might observe a value wrapped in
a thunk.

In these cases, the implementation of `Display` and `PartialEq` must
delegate to the underlying value.

Note that there are a handful of other cases like these which we need
to cover.

It is a little tricky to write integration tests for these directly,
especially as some of the open-upvalue optimisations coming down the
pipe will reduce the number of observable thunks.

One test that covers a part of this behaviour is currently
disabled (needs some more machinery), but it's being brought back in
the next commits.

Change-Id: Iaa8cd338c12236af844bbc99d8cec2205f0d0095
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6370
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
2022-09-07 19:08:56 +00:00
Vincent Ambo
38d3db5fb8 feat(tvix/eval): implement NixAttrs::iter()
Implementing iteration over NixAttrs requires a custom iterator type
in order to encapsulate the different representations. The BTreeMap
for example has its own iterator type which needs to be encapsulated.

This is mostly boilerplate code, but for a change some simple unit
tests have been added in.

Change-Id: Ie13b063241d461b810876f95f53878388e918ef2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6367
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 15:25:59 +00:00
Vincent Ambo
7d5dca7ba3 chore(tvix/eval): provide 'static references to "name"/"value"
These static strings show up a bunch when dealing with the internals
of attribute sets, and having them available as static references is
required.

Due to the way const expressions are evaluated, taking a reference to
the existing NixString::NAME / NixString::VALUE items does not work
and the references themselves need to be const-evaluated.

Change-Id: If6e75847af978118a3b266fe6a3242321722434d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6366
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 15:25:59 +00:00
Vincent Ambo
80713f207e refactor(tvix/eval): encapsulate all thunk-forcing logic in module
The VM previously took care of repeatedly forcing a thunk until it
reached an evaluated state. This logic is now encapsulated inside of
the `Thunk::force` implementation.

In addition, force no longer returns a reference to the value by
default, leaving it up to callers to decide whether they want to
borrow the value or not (a helper is provided for this).

Change-Id: I2aa7da922058ad1c57fbf8bfc7785aab7971c02b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6365
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 15:25:59 +00:00
Vincent Ambo
23a5caabec feat(tvix/eval): construct attribute sets lazily
This thunks the construction of attribute sets. Because Tvix does not
currently have a "strict output" mode, a test had to be disabled that
now displays a thunk representation.

The test will be re-enabled once that is available.

Change-Id: I360332be64cd5c154f9caea21828f6f1b37a265c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6363
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 15:25:59 +00:00