Changes the internal compiler plumbing to not just return a chunk of
code, but the same chunk wrapped inside of a lambda value.
This is one more step towards compiling runtime lambdas.
Change-Id: If0035f8e65a2970c5ae123fc068a2396e1d8fd72
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6240
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
With these indirections in place it becomes easier to change internals
of the compiler when introducing functions, which need the compiler to
be able to target different code chunks.
Change-Id: I4eb11572a93c140b1d059ba0a5af905756745d65
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6239
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Instead of exiting the compiler at the first sight of an error,
skip any erroneous nodes and continue compiling, collecting more
errors along the way.
This paves the way for nicer error reporting in which multiple errors
can be reported at once, avoiding situations in which users are
hunting a fault error-by-error and possibly getting distracted by
less useful output.
Change-Id: I80c9a87272e33a31297167ae2eb2706a46adf15a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6236
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
This starts paving the way for nicer, source-code based error
reporting.
Right now the code paths in the VM do not emit annotated errors, as we
do not yet preserve that structure from the compiler. However, error
emitting code paths in the compiler have been amended to include known
nodes.
Change-Id: I1b74410ffd891c40cd913361bd73c4336ec8aa5b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6235
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
In this commit, the string interpolation parsing is identical to
nixpkgs which makes some of the upstream Nix tests for
interpolation-related weirdness pass.
Change-Id: I3a295cfdc404c32228a54846e6efd3c0dcee5842
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6233
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
These were missing an additional level of escaping, silly oversight
caught by an upstream test.
Change-Id: I0312084475e4b88c83945614e9aa5b34c6bc3ec2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6232
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Since the latest published version of rnix-parser on crates.io, the
crate has undergone major changes which are only available in the git
repository at the moment. This commit updates the compiler to this
newer version of rnix.
Most notably, the entire AST provided by rnix is now wrapped in the
AST type system. As a result of this traversal is much nicer in many
places, especially for things like nested attribute selection.
There are a handful of smaller features missing for full feature
parity with the previous version, especially handling of path
literals, but PRs for these already exist in rnix-parser.
Change-Id: Icde6d393067976549492b7d89c4cc49e5e575fc7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6231
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
This implements `assert`, which evaluates an expression and aborts
evaluation if the value is not `true`.
At this point we should introduce eval-failed-* tests; probably
asserting against some representation of the error enum?
Change-Id: If54c8f616d89b829c1860a4835dde60a2cd70d7a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6230
Reviewed-by: grfn <grfn@gws.fyi>
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
This makes for much more readable output especially when long strings
are involved.
Change-Id: I43dd73a0480535d7181a760788c42883a9b083f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6229
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
`push_local`/`push_phantom` were worse names because they sound like
the value itself is being pushed, where in actuality it is just being
declared to the compiler.
Change-Id: Ibfda5c4c8e47d5d3262bfe005b0f1f84908a117e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6228
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
These tokens are optionally parsed as identifiers by Nix, which means
that within any scopes that resolve them the compiler needs to track
whether they have been overridden to know whether to emit the literal
instructions or resolve a variable.
This is implemented by a new concept of "scope poisoning", where the
compiler's scope structure tracks whether or not any builtin
identifiers have been overridden.
Change-Id: I3ab711146e229f843f6e1f0343385382ee0aecb6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6227
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
While full recursion through thunking is not available, there are
actually incorrect behaviours introduced by declaring before
binding (example in the newly introduced test).
This commit simplifies the implementation to avoid this issue, and
also because I intend to explore a bit more how far we can get in non
left-to-right bindings *without* introducing thunks immediately.
Change-Id: I21fd3007ac3946570639772d7d624d70bd209958
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6226
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
If an unknown variable is encountered and the with stack is not empty,
emit instructions for resolving the variable at runtime.
Change-Id: I752f4bd0025335744e4747364abd1bd34130374e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6223
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Adds an additional structure to the compiler's scope to track the
runtime "with stack", i.e. the stack of values through which
identifiers should be dynamically resolved within a with-scope.
When encountering a `with` expression, the value from which the
bindings should be resolved is pushed onto the stack and tracked by
the compiler in the "with stack", as well as with a "phantom value"
which indicates that the stack contains an additional slot which is
not available to users via identifiers.
Runtime handling of this is not yet implemented.
Change-Id: I5e96fb55b6378e8e2a59c20c8518caa6df83da1c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6217
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
This name is much more sensible actually; its more than just a
collection of locals as it tracks additional scope information in the
case of Nix.
Change-Id: Ia2739bbd39aab222b1c4355e9248828973b0db43
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6216
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Note that at this point recursive bindings do not yet work in either
attrsets or let, so inheriting from the same scope is generally not
possible yet.
Change-Id: I6ca820d04b8ded5c22fb7ea18e2ec203bcaa8e9c
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6215
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Straightforward implementation, evaluating the elements of an inherit
and preparing the stack so that `OpAttrs` sees all relevant values
when constructing the attribute set itself.
The emitted instructions for inheriting a lot of values from the same
attribute set are inefficient, but it's too early to say whether this
actually matters.
Change-Id: Icb55a20936d4ef77173f34433811c5fa5d2c9ecc
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6214
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
If the directory in which REPL history is stored does not exist,
gently try to create it, but do not raise an error if it doesn't work.
We may want to warn about it, but in general this sort of
non-essential feature should not cause a hard failure.
Change-Id: If4fe8db0c7893c39627efe72c9cd9ebf7ed63f04
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6213
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Using `OpAttrSelect`, the ? operator will fail when encountering a
nested value that is not an attribute set.
This however breaks valid code, such as:
{ bs = 42; } ? bs.a.b
The fix is simply to use the same operator used in the `or` statement,
which leaves a sentinal on the stack if a field is not found or the
value is not an attribute set.
Change-Id: Ib28fc8a96e6d592b4cdbc3e65ba129ad8faecd66
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6211
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
If a nested attrpath encounters a non-set value, the sentinel value
denoting a lack of next values should be emitted. This mirrors the
behaviour of Nix.
Change-Id: Ia80443d5a11243cc6d98dcab1249a3f5fdf77e27
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6210
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Not sure how exactly this snuck in, but it caused some subtle
breakages in deeply nested attribute sets.
Change-Id: I8049ce912405d3750031f79cc8d86ff1c3c02c2b
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6208
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
We're confident that we're handling all branches that can reasonably
occur from valid AST, any other cases should be considered a critical
evaluator bug and panic rather than surfacing something that looks
like user error.
Change-Id: If96966eb32b8ff12fcaeb9ea3b0c8fc51b6abd11
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6205
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
This is actually *tested* behaviour in C++ Nix, so we need to
implement it here, too.
Change-Id: Ic4a4659a2f04cdd928cbe78a85dae90401515371
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6199
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
This adds a `disassembler` feature to the crate configuration that
traces the operations executed and the state of the stack at runtime.
This can be enabled by compiling with `--feature disassembler`.
This will also gain a more sensible layout of code slices eventually.
Change-Id: I34c15e1cd346ecc4362b5afba6bf82dd49359d20
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6193
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Using `inherit` in a let-binding can not possibly have an effect, as
the given identifier is already bound exactly the same way in the
current scope.
This introduces a subtle bug that is fixed later on, as there
actually *is* a (single) condition where these inherits are
meaningful.
Change-Id: I8b24f0edcfe80db8153bb7e86cf478d36957d6f8
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6192
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
This makes basic `let ... in ...` statements work correctly. It does
not yet account for the call frames pushed into the VM during function
application.
Change-Id: I67155171daf1a43011b96716dd9d1ab04b27db33
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6190
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
Nix does not allow dynamic identifiers in let expressions (only in
attribute sets), but there are several different kinds of things it
considers static identifiers.
The functions introduced here put the path components of a let
expression into normalised (string) form, and surface an error about
dynamic keys if one is encountered.
Change-Id: Ia3ebd95c6f3ed3cd33b94e156930d2e9c39b6cbf
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6189
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
These expressions now leave the binding values on the stack, and clean
up the scope after the body of the expression.
While variable access is not yet implemented (as the identifier node
remains unhandled), this already gives us the correct stack behaviour.
Change-Id: I138c20ace9c64502c94b2c0f99a6077cd912c00d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6188
Tested-by: BuildkiteCI
Reviewed-by: grfn <grfn@gws.fyi>
These are going to be used during compilation of `let`-expressions to
determine stack offsets for local variables.
Change-Id: Ibb79f3f1ae86650303f88eacf623ae456458de87
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6187
Reviewed-by: grfn <grfn@gws.fyi>
Tested-by: BuildkiteCI
Canonicalisation performs much more functionality than what C++ Nix
implements for paths, and causes some undesirable behaviour (e.g.
handling non-existant files becomes difficult, but should be possible
in literals).
Instead, the path_clean crate provides a pure normalisation method.
There is an intention to add this to Rust itself:
https://github.com/rust-lang/rfcs/issues/2208
Change-Id: I775d238136db0a52cf6b12a68985833c8fb32882
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6186
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Resolves relative paths (e.g. `./foo`) either relative to the location
of the Nix file, or relative to the working directory if none is
supplied.
Change-Id: I70ec574657b221b458015117a004b6e4a9c25a30
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6185
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
