maurice/snix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

feat(tvix/eval): Initial resolution of <...> paths

Browse source 
This commit implements (lazy) resolution of `<...>` paths via either the
NIX_PATH environment variable, or the -I command-line flag - both
handled via EvalOptions. As a result, EvalOptions can no longer derive
Copy, meaning we have to clone it at each line of the repl - this is
probably not a huge deal as repl performance is not exactly an inner
loop and we're not cloning very much.

Internally, this works by creating a thunk which pushes a constant
containing the string inside the brackets to the stack, then a new
opcode to resolve that path via the `NixPath`. To get that opcode to
work, we now have to pass in the NixPath when constructing the VM.

This (intentionally) leaves out proper implementation of path resolution
via `findFile` (cppnix just calls whatever identifier called findFile is
in scope!!!) as that's widely considered a bit of a misfeature, but if
we do decide to implement that down the road it likely wouldn't be more
than a few extra ops within the thunk introduced here.

Change-Id: Ibc979b7e425b65cbe88599940520239a4a10cee2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6918
Autosubmit: grfn <grfn@gws.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
This commit is contained in:
Griffin Smith 2022-10-09 23:46:51 -04:00 • committed by grfn
parent 5e2b44b416
commit 273ba73754
9 changed files with 77 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

19
tvix/eval/src/eval.rs
View file

@ -3,13 +3,14 @@ use std::{cell::RefCell, path::PathBuf, rc::Rc};
use crate::{
builtins::global_builtins,
errors::{Error, ErrorKind, EvalResult},
nix_path::NixPath,
observer::{DisassemblingObserver, NoOpObserver, TracingObserver},
value::Value,
SourceCode,
};
/// Runtime options for the Tvix interpreter
#[derive(Debug, Clone, Copy, Default)]
#[derive(Debug, Clone, Default)]
#[cfg_attr(feature = "repl", derive(clap::Parser))]
pub struct Options {
/// Dump the raw AST to stdout before interpreting
@ -23,6 +24,10 @@ pub struct Options {
/// Trace the runtime of the VM
#[cfg_attr(feature = "repl", clap(long, env = "TVIX_TRACE_RUNTIME"))]
trace_runtime: bool,
/// A colon-separated list of directories to use to resolve `<...>`-style paths
#[cfg_attr(feature = "repl", clap(long, short = 'I', env = "NIX_PATH"))]
nix_path: Option<NixPath>,
}
pub fn interpret(code: &str, location: Option<PathBuf>, options: Options) -> EvalResult<Value> {
@ -105,9 +110,17 @@ pub fn interpret(code: &str, location: Option<PathBuf>, options: Options) -> Eva
}
let result = if options.trace_runtime {
crate::vm::run_lambda(&mut TracingObserver::new(std::io::stderr()), result.lambda)
crate::vm::run_lambda(
options.nix_path.unwrap_or_default(),
&mut TracingObserver::new(std::io::stderr()),
result.lambda,
)
} else {
crate::vm::run_lambda(&mut NoOpObserver::default(), result.lambda)
crate::vm::run_lambda(
options.nix_path.unwrap_or_default(),
&mut NoOpObserver::default(),
result.lambda,
)
};
if let Err(err) = &result {