Commit graph

7 commits

Author SHA1 Message Date
Vincent Ambo
17dfb92a9f chore(tvix/eval): implement Debug for compiler::scope::Scope
Change-Id: I112b0119bd0511f26bb72f7e73d867d1b7144a36
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6359
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-07 15:25:59 +00:00
Vincent Ambo
24811d7655 fix(tvix/eval): distinguish statically between StackIdx and LocalIdx
Previously the functions in the scope module returned usize values,
which - sometimes from the same function - were either indexes into
the runtime stack *or* indexes into the compiler's local stack.

This is extremely confusing because it requires the caller to be aware
of the difference, and it actually caused subtle bugs.

To avoid this, there is now a new LocalIdx wrapper type which is used
by the scope module to return indexes into the compiler's stack, as
well as helpers for accounting for the differences between these
indexes and the runtime indexes.

Change-Id: I58f0b50ad94b28a304e3372fd9731b6590b3fdb8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6340
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-06 14:58:52 +00:00
Vincent Ambo
5c4e102ac8 feat(tvix/eval): track whether locals needs to be finalised
When encountering a deferred local upvalue, the compiler will now mark
the corresponding local as needing a finaliser which makes it possible
to emit the OpFinalise instruction for this stack slot a little bit
down the line.

Change-Id: I3962066f10fc6c6e1472722b8bdb415a811e0740
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6338
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-06 14:58:52 +00:00
Vincent Ambo
47b3562867 refactor(tvix/eval): decouple local depth & initialisation tracking
In order to resolve recursive references correctly, these two can not
be initialised the same way as a potentially large number of (nested!)
locals can be declared without initialising their depth.

This would lead to issues with detecting things like shadowed
variables, so making both bits explicit is preferable.

Change-Id: I100cdf1724faa4a2b5a0748429841cf8ef206252
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6325
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-06 07:45:43 +00:00
Vincent Ambo
8982e16e26 refactor(tvix/eval): thread dynamic upvalues through all contexts
With this change, encountering a dynamic upvalue will thread through
all contexts starting from the lowest context that has a non-empty
`with`-stack.

The additional upvalues are not actually used yet, so the effective
behaviour remains mostly the same. This is done in preparation for an
upcoming change, which will implement proper dynamic resolution for
complex cases of nested dynamic upvalues.

Yes, this whole upvalue + dynamic values thing is a little bit
mind-bending, but we would like to not give up being able to resolve a
large chunk of the scoping behaviour statically.

Change-Id: Ia58cdd47d79212390a6503ef13cef46b6b3e19a2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6321
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-06 07:45:43 +00:00
Vincent Ambo
932a70d0c2 refactor(tvix/eval): track with stack size as a simple integer
The `With` struct no longer contained any internals after the cleanup
logic for the stack had been moved into Compiler::compile_with,
leaving the `Vec<With>` to essentially act as a counter for the number
of things on the with stack.

That's inefficient of course, so with this commit it actually becomes
an integer (with an encapsulated API within scope::Scope).

Change-Id: I67a00987fc8b46b30d369a96d41e83c8af5b1998
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6311
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-04 17:53:08 +00:00
Vincent Ambo
2cd08d136e refactor(tvix/eval): move compiler's scope logic to separate module
The compiler module is getting quite long and this will help keep some
order.

Right now the scope internals are not very well encapsulated; this
paves a way to reducing the API surface of the `scope` type to the
things that are actually used by the compiler instead of giving access
to its internals.

Change-Id: I8c16c26d263f018baa263f395c9cd80715199241
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6310
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-04 17:53:08 +00:00