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refactor(tvix/eval): Drop LightSpan entirely

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This was made unnecessary in c92d06271 (feat(tvix/eval): drop
LightSpan::Delayed, 2023-12-08) because it didn't improve benchmarks as
much as expected and has been vestigial since; this continues the
cleanup by just removing it altogether

Change-Id: I21ec7ae9b52a5cccd2092696a5a87f658194d672
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11949
Autosubmit: aspen <root@gws.fyi>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>
This commit is contained in:
Aspen Smith 2024-07-04 13:42:50 -04:00 • committed by clbot
parent 8e31088a01
commit 6037888e18
8 changed files with 109 additions and 175 deletions
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64
tvix/eval/src/vm/generators.rs
View file

@ -81,7 +81,7 @@ pub enum VMRequest {
EnterLambda {
lambda: Rc<Lambda>,
upvalues: Rc<Upvalues>,
light_span: LightSpan,
span: Span,
},
/// Emit a runtime warning (already containing a span) through the VM.
@ -198,7 +198,7 @@ pub enum VMResponse {
Directory(Vec<(bytes::Bytes, FileType)>),
/// VM response with a span to use at the current point.
Span(LightSpan),
Span(Span),
/// [std::io::Reader] produced by the VM in response to some IO operation.
Reader(Box<dyn std::io::Read>),
@ -234,7 +234,7 @@ where
{
/// Helper function to re-enqueue the current generator while it
/// is awaiting a value.
fn reenqueue_generator(&mut self, name: &'static str, span: LightSpan, generator: Generator) {
fn reenqueue_generator(&mut self, name: &'static str, span: Span, generator: Generator) {
self.frames.push(Frame::Generator {
name,
generator,
@ -244,7 +244,7 @@ where
}
/// Helper function to enqueue a new generator.
pub(super) fn enqueue_generator<F, G>(&mut self, name: &'static str, span: LightSpan, gen: G)
pub(super) fn enqueue_generator<F, G>(&mut self, name: &'static str, span: Span, gen: G)
where
F: Future<Output = Result<Value, ErrorKind>> + 'static,
G: FnOnce(GenCo) -> F,
@ -265,7 +265,7 @@ where
pub(crate) fn run_generator(
&mut self,
name: &'static str,
span: LightSpan,
span: Span,
frame_id: usize,
state: GeneratorState,
mut generator: Generator,
@ -302,8 +302,8 @@ where
// this function prepares the frame stack and yields
// back to the outer VM loop.
VMRequest::ForceValue(value) => {
self.reenqueue_generator(name, span.clone(), generator);
self.enqueue_generator("force", span.clone(), |co| {
self.reenqueue_generator(name, span, generator);
self.enqueue_generator("force", span, |co| {
value.force_owned_genco(co, span)
});
return Ok(false);
@ -311,8 +311,8 @@ where
// Generator has requested a deep-force.
VMRequest::DeepForceValue(value) => {
self.reenqueue_generator(name, span.clone(), generator);
self.enqueue_generator("deep_force", span.clone(), |co| {
self.reenqueue_generator(name, span, generator);
self.enqueue_generator("deep_force", span, |co| {
value.deep_force(co, span)
});
return Ok(false);
@ -322,10 +322,10 @@ where
// Logic is similar to `ForceValue`, except with the
// value being taken from that stack.
VMRequest::WithValue(idx) => {
self.reenqueue_generator(name, span.clone(), generator);
self.reenqueue_generator(name, span, generator);
let value = self.stack[self.with_stack[idx]].clone();
self.enqueue_generator("force", span.clone(), |co| {
self.enqueue_generator("force", span, |co| {
value.force_owned_genco(co, span)
});
@ -336,13 +336,13 @@ where
// with-stack. Logic is same as above, except for the
// value being from that stack.
VMRequest::CapturedWithValue(idx) => {
self.reenqueue_generator(name, span.clone(), generator);
self.reenqueue_generator(name, span, generator);
let call_frame = self.last_call_frame()
.expect("Tvix bug: generator requested captured with-value, but there is no call frame");
let value = call_frame.upvalues.with_stack().unwrap()[idx].clone();
self.enqueue_generator("force", span.clone(), |co| {
self.enqueue_generator("force", span, |co| {
value.force_owned_genco(co, span)
});
@ -351,23 +351,23 @@ where
VMRequest::NixEquality(values, ptr_eq) => {
let values = *values;
self.reenqueue_generator(name, span.clone(), generator);
self.enqueue_generator("nix_eq", span.clone(), |co| {
self.reenqueue_generator(name, span, generator);
self.enqueue_generator("nix_eq", span, |co| {
values.0.nix_eq_owned_genco(values.1, co, ptr_eq, span)
});
return Ok(false);
}
VMRequest::StringCoerce(val, kind) => {
self.reenqueue_generator(name, span.clone(), generator);
self.enqueue_generator("coerce_to_string", span.clone(), |co| {
self.reenqueue_generator(name, span, generator);
self.enqueue_generator("coerce_to_string", span, |co| {
val.coerce_to_string(co, kind, span)
});
return Ok(false);
}
VMRequest::Call(callable) => {
self.reenqueue_generator(name, span.clone(), generator);
self.reenqueue_generator(name, span, generator);
self.call_value(span, None, callable)?;
return Ok(false);
}
@ -375,12 +375,12 @@ where
VMRequest::EnterLambda {
lambda,
upvalues,
light_span,
span,
} => {
self.reenqueue_generator(name, span, generator);
self.frames.push(Frame::CallFrame {
span: light_span,
span,
call_frame: CallFrame {
lambda,
upvalues,
@ -424,7 +424,7 @@ where
path: Some(path),
error: e.into(),
})
.with_span(&span, self)?;
.with_span(span, self)?;
message = VMResponse::Path(imported);
}
@ -438,7 +438,7 @@ where
path: Some(path),
error: e.into(),
})
.with_span(&span, self)?;
.with_span(span, self)?;
message = VMResponse::Reader(reader)
}
@ -453,7 +453,7 @@ where
error: e.into(),
})
.map(Value::Bool)
.with_span(&span, self)?;
.with_span(span, self)?;
message = VMResponse::Value(exists);
}
@ -467,31 +467,31 @@ where
path: Some(path),
error: e.into(),
})
.with_span(&span, self)?;
.with_span(span, self)?;
message = VMResponse::Directory(dir);
}
VMRequest::Span => {
message = VMResponse::Span(self.reasonable_light_span());
message = VMResponse::Span(self.reasonable_span);
}
VMRequest::TryForce(value) => {
self.try_eval_frames.push(frame_id);
self.reenqueue_generator(name, span.clone(), generator);
self.reenqueue_generator(name, span, generator);
debug_assert!(
self.frames.len() == frame_id + 1,
"generator should be reenqueued with the same frame ID"
);
self.enqueue_generator("force", span.clone(), |co| {
self.enqueue_generator("force", span, |co| {
value.force_owned_genco(co, span)
});
return Ok(false);
}
VMRequest::ToJson(value) => {
self.reenqueue_generator(name, span.clone(), generator);
self.reenqueue_generator(name, span, generator);
self.enqueue_generator("to_json", span, |co| {
value.into_contextful_json_generator(co)
});
@ -503,7 +503,7 @@ where
// Generator has completed, and its result value should
// be left on the stack.
genawaiter::GeneratorState::Complete(result) => {
let value = result.with_span(&span, self)?;
let value = result.with_span(span, self)?;
self.stack.push(value);
return Ok(true);
}
@ -683,12 +683,12 @@ pub(crate) async fn request_enter_lambda(
co: &GenCo,
lambda: Rc<Lambda>,
upvalues: Rc<Upvalues>,
light_span: LightSpan,
span: Span,
) -> Value {
let msg = VMRequest::EnterLambda {
lambda,
upvalues,
light_span,
span,
};
match co.yield_(msg).await {
@ -767,7 +767,7 @@ pub(crate) async fn request_read_dir(co: &GenCo, path: PathBuf) -> Vec<(bytes::B
}
}
pub(crate) async fn request_span(co: &GenCo) -> LightSpan {
pub(crate) async fn request_span(co: &GenCo) -> Span {
match co.yield_(VMRequest::Span).await {
VMResponse::Span(span) => span,
msg => panic!(

2
tvix/eval/src/vm/macros.rs
View file

@ -49,7 +49,7 @@ macro_rules! cmp_op {
}
}
let gen_span = $frame.current_light_span();
let gen_span = $frame.current_span();
$vm.push_call_frame($span, $frame);
$vm.enqueue_generator("compare", gen_span, |co| compare(a, b, co));
return Ok(false);

74
tvix/eval/src/vm/mod.rs
View file

@ -28,7 +28,6 @@ use crate::{
nix_search_path::NixSearchPath,
observer::RuntimeObserver,
opcode::{CodeIdx, Count, JumpOffset, OpCode, StackIdx, UpvalueIdx},
spans::LightSpan,
upvalues::Upvalues,
value::{
Builtin, BuiltinResult, Closure, CoercionKind, Lambda, NixAttrs, NixContext, NixList,
@ -51,7 +50,7 @@ trait GetSpan {
impl<'o, IO> GetSpan for &VM<'o, IO> {
fn get_span(self) -> Span {
self.reasonable_span.span()
self.reasonable_span
}
}
@ -61,9 +60,9 @@ impl GetSpan for &CallFrame {
}
}
impl GetSpan for &LightSpan {
impl GetSpan for &Span {
fn get_span(self) -> Span {
self.span()
*self
}
}
@ -94,7 +93,7 @@ impl<T, S: GetSpan, IO> WithSpan<T, S, IO> for Result<T, ErrorKind> {
Frame::CallFrame { span, .. } => {
error = Error::new(
ErrorKind::BytecodeError(Box::new(error)),
span.span(),
*span,
vm.source.clone(),
);
}
@ -104,7 +103,7 @@ impl<T, S: GetSpan, IO> WithSpan<T, S, IO> for Result<T, ErrorKind> {
err: Box::new(error),
gen_type: name,
},
span.span(),
*span,
vm.source.clone(),
);
}
@ -163,13 +162,6 @@ impl CallFrame {
pub fn current_span(&self) -> Span {
self.chunk().get_span(self.ip - 1)
}
/// Returns the information needed to calculate the current span,
/// but without performing that calculation.
// TODO: why pub?
pub(crate) fn current_light_span(&self) -> LightSpan {
LightSpan::new_actual(self.current_span())
}
}
/// A frame represents an execution state of the VM. The VM has a stack of
@ -187,7 +179,7 @@ enum Frame {
call_frame: CallFrame,
/// Span from which the call frame was launched.
span: LightSpan,
span: Span,
},
/// Generator represents a frame that can yield further
@ -201,7 +193,7 @@ enum Frame {
name: &'static str,
/// Span from which the generator was launched.
span: LightSpan,
span: Span,
state: GeneratorState,
@ -211,9 +203,9 @@ enum Frame {
}
impl Frame {
pub fn span(&self) -> LightSpan {
pub fn span(&self) -> Span {
match self {
Frame::CallFrame { span, .. } | Frame::Generator { span, .. } => span.clone(),
Frame::CallFrame { span, .. } | Frame::Generator { span, .. } => *span,
}
}
}
@ -309,7 +301,7 @@ struct VM<'o, IO> {
///
/// The VM should update this whenever control flow changes take place (i.e.
/// entering or exiting a frame to yield control somewhere).
reasonable_span: LightSpan,
reasonable_span: Span,
/// This field is responsible for handling `builtins.tryEval`. When that
/// builtin is encountered, it sends a special message to the VM which
@ -343,7 +335,7 @@ where
observer: &'o mut dyn RuntimeObserver,
source: SourceCode,
globals: Rc<GlobalsMap>,
reasonable_span: LightSpan,
reasonable_span: Span,
) -> Self {
Self {
nix_search_path,
@ -362,7 +354,7 @@ where
}
/// Push a call frame onto the frame stack.
fn push_call_frame(&mut self, span: LightSpan, call_frame: CallFrame) {
fn push_call_frame(&mut self, span: Span, call_frame: CallFrame) {
self.frames.push(Frame::CallFrame { span, call_frame })
}
@ -444,7 +436,7 @@ where
///
/// The return value indicates whether the bytecode has been executed to
/// completion, or whether it has been suspended in favour of a generator.
fn execute_bytecode(&mut self, span: LightSpan, mut frame: CallFrame) -> EvalResult<bool> {
fn execute_bytecode(&mut self, span: Span, mut frame: CallFrame) -> EvalResult<bool> {
loop {
let op = frame.inc_ip();
self.observer.observe_execute_op(frame.ip, &op, &self.stack);
@ -464,7 +456,7 @@ where
);
Thunk::new_closure(blueprint)
} else {
Thunk::new_suspended(blueprint, frame.current_light_span())
Thunk::new_suspended(blueprint, frame.current_span())
};
let upvalues = thunk.upvalues_mut();
self.stack.push(Value::Thunk(thunk.clone()));
@ -484,10 +476,10 @@ where
_ => unreachable!(),
};
let gen_span = frame.current_light_span();
let gen_span = frame.current_span();
self.push_call_frame(span, frame);
self.enqueue_generator("force", gen_span.clone(), |co| {
self.enqueue_generator("force", gen_span, |co| {
Thunk::force(thunk, co, gen_span)
});
@ -515,7 +507,7 @@ where
OpCode::OpCall => {
let callable = self.stack_pop();
self.call_value(frame.current_light_span(), Some((span, frame)), callable)?;
self.call_value(frame.current_span(), Some((span, frame)), callable)?;
// exit this loop and let the outer loop enter the new call
return Ok(true);
@ -640,9 +632,9 @@ where
OpCode::OpEqual => lifted_pop! {
self(b, a) => {
let gen_span = frame.current_light_span();
let gen_span = frame.current_span();
self.push_call_frame(span, frame);
self.enqueue_generator("nix_eq", gen_span.clone(), |co| {
self.enqueue_generator("nix_eq", gen_span, |co| {
a.nix_eq_owned_genco(b, co, PointerEquality::ForbidAll, gen_span)
});
return Ok(false);
@ -739,7 +731,7 @@ where
let ident = self.stack_pop().to_str().with_span(&frame, self)?;
// Re-enqueue this frame.
let op_span = frame.current_light_span();
let op_span = frame.current_span();
self.push_call_frame(span, frame);
// Construct a generator frame doing the lookup in constant
@ -770,10 +762,10 @@ where
OpCode::OpCoerceToString(kind) => {
let value = self.stack_pop();
let gen_span = frame.current_light_span();
let gen_span = frame.current_span();
self.push_call_frame(span, frame);
self.enqueue_generator("coerce_to_string", gen_span.clone(), |co| {
self.enqueue_generator("coerce_to_string", gen_span, |co| {
value.coerce_to_string(co, kind, gen_span)
});
@ -808,7 +800,7 @@ where
OpCode::OpAdd => lifted_pop! {
self(b, a) => {
let gen_span = frame.current_light_span();
let gen_span = frame.current_span();
self.push_call_frame(span, frame);
// OpAdd can add not just numbers, but also string-like
@ -1004,12 +996,6 @@ where
Ok(())
}
/// Returns a reasonable light span for the current situation that the VM is
/// in.
pub fn reasonable_light_span(&self) -> LightSpan {
self.reasonable_span.clone()
}
/// Apply an argument from the stack to a builtin, and attempt to call it.
///
/// All calls are tail-calls in Tvix, as every function application is a
@ -1017,7 +1003,7 @@ where
///
/// Due to this, once control flow exits this function, the generator will
/// automatically be run by the VM.
fn call_builtin(&mut self, span: LightSpan, mut builtin: Builtin) -> EvalResult<()> {
fn call_builtin(&mut self, span: Span, mut builtin: Builtin) -> EvalResult<()> {
let builtin_name = builtin.name();
self.observer.observe_enter_builtin(builtin_name);
@ -1041,8 +1027,8 @@ where
fn call_value(
&mut self,
span: LightSpan,
parent: Option<(LightSpan, CallFrame)>,
span: Span,
parent: Option<(Span, CallFrame)>,
callable: Value,
) -> EvalResult<()> {
match callable {
@ -1098,7 +1084,7 @@ where
Ok(())
}
v => Err(ErrorKind::NotCallable(v.type_of())).with_span(&span, self),
v => Err(ErrorKind::NotCallable(v.type_of())).with_span(span, self),
}
}
@ -1345,17 +1331,17 @@ where
observer,
source,
globals,
root_span.into(),
root_span,
);
// When evaluating strictly, synthesise a frame that will instruct
// the VM to deep-force the final value before returning it.
if strict {
vm.enqueue_generator("final_deep_force", root_span.into(), final_deep_force);
vm.enqueue_generator("final_deep_force", root_span, final_deep_force);
}
vm.frames.push(Frame::CallFrame {
span: root_span.into(),
span: root_span,
call_frame: CallFrame {
lambda,
upvalues: Rc::new(Upvalues::with_capacity(0)),