Commit graph

17275 commits

Author SHA1 Message Date
sterni
f95b23d743 test(tvix/eval): test “useful” plain inherits
Change-Id: Ic4700f0618a393e45a2ee7c70045edff97e30c49
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6493
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:26:23 +00:00
sterni
4d8f35353b fix(tvix/eval): declare let inherit (from) locals before compiling
The recent change that split declaration of let based locals and the
compilation of their values did not touch locals bound by inherit in
let. These were previously declared and compiled immediately before
starting to work on the other locals introduced in a let.

In the case of plain inherits, this behavior is kept in this change,
because there's nothing wrong with it: The value of a plain inherit will
always resolve to a higher scope, either statically or dynamically.

Since inherit (from) expression might refer to other locals bound in the
same let, we need to handle them in the same three steps as ordinary let
based locals:

1. We need to declare the (uninitialised) locals.

2. We need to compile the expression that obtains their value. For this,
   we create a new thunk, since the from expression may very well return
   a thunk which we need to force before selecting the value we are
   interested in.

3. Thunks need to be finalised.

For 1., we create an extra pass over the inherits that already declares
and initialises plain inherits and notes inherit (from) expressions in
the entries vector after declaring them. 2. only needs a bit of adapting
to create the thunks for selecting if appropriate, the rest of the
existing code can be reused.

Change-Id: Ie4ac1c0f9ffcbf7c07c452036aa8e577443af773
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6490
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: tazjin <tazjin@tvl.su>
2022-09-11 12:26:23 +00:00
Vincent Ambo
b4309f5b8a docs(tvix/eval): add some notes on recursive attribute sets
Change-Id: I36b826f12854a22e60a27ed1982ab5528c58bdad
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6489
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:26:23 +00:00
Vincent Ambo
e944c341a7 docs(tvix/eval): add optimisation note on eliminating with thunks
Change-Id: I18d50ac8e157929a027f8bf284e65f1eb8950d5a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6488
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:26:23 +00:00
Vincent Ambo
627dfabef1 fix(tvix/eval): thunk all uses of with
With this all other "weird scope" logic starts working for `with` as
well.

Change-Id: I0ea1d8c5fbd9cec5084bd574224f77b71ff2b487
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6487
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:26:23 +00:00
Vincent Ambo
07ea30370e refactor(tvix/eval): capture entire with_stack in upvalues
This completely rewrites the handling of "dynamic upvalues" to,
instead of resolving them at thunk/closure instantiation time (which
forces some values too early), capture the entire with stack of parent
contexts if it exists.

There are a couple of things in here that could be written more
efficiently, but I'm first working through this to get to a bug
related to with + recursion and the code complexity of some of the
optimisations is distracting.

Change-Id: Ia538e06c9146e3bf8decb9adf02dd726d2c651cf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6486
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 12:26:23 +00:00
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
5eda0fbd86 feat(corp/tvixbolt): add Nix build instructions
Now that tvix-eval has almost caught up, tvixbolt can be built in
the depot tree.

Change-Id: Ib26dd98727b110ad8d668aec60db99678644a167
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6491
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 10:45:22 +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
41b6586ee1 chore(tvix): remove stale .envrc
This doesn't actually do anything other than causing errors for the
current state of this folder.

Change-Id: I0af6410e9eb1700cd0b2b105c8adde077d931a69
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6492
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-11 10:25:18 +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