diff options
| -rw-r--r-- | tvix/eval/src/builtins/impure.rs | 3 | ||||
| -rw-r--r-- | tvix/eval/src/compiler/mod.rs | 3 | ||||
| -rw-r--r-- | tvix/eval/src/spans.rs | 37 | ||||
| -rw-r--r-- | tvix/eval/src/value/thunk.rs | 21 | ||||
| -rw-r--r-- | tvix/eval/src/vm.rs | 9 |
5 files changed, 61 insertions, 12 deletions
diff --git a/tvix/eval/src/builtins/impure.rs b/tvix/eval/src/builtins/impure.rs index ee6cb2afde..b086df2f84 100644 --- a/tvix/eval/src/builtins/impure.rs +++ b/tvix/eval/src/builtins/impure.rs @@ -12,6 +12,7 @@ use crate::{ compiler::GlobalsMap, errors::ErrorKind, observer::NoOpObserver, + spans::LightSpan, value::{Builtin, BuiltinArgument, NixAttrs, Thunk}, vm::VM, SourceCode, Value, @@ -176,7 +177,7 @@ pub fn builtins_import(globals: &Weak<GlobalsMap>, source: SourceCode) -> Builti let res = entry .insert(Value::Thunk(Thunk::new_suspended( result.lambda, - current_span, + LightSpan::new_actual(current_span), ))) .clone(); diff --git a/tvix/eval/src/compiler/mod.rs b/tvix/eval/src/compiler/mod.rs index b8d8fb11a2..ae31d27145 100644 --- a/tvix/eval/src/compiler/mod.rs +++ b/tvix/eval/src/compiler/mod.rs @@ -28,6 +28,7 @@ use crate::chunk::Chunk; use crate::errors::{Error, ErrorKind, EvalResult}; use crate::observer::CompilerObserver; use crate::opcode::{CodeIdx, Count, JumpOffset, OpCode, UpvalueIdx}; +use crate::spans::LightSpan; use crate::spans::ToSpan; use crate::value::{Closure, Formals, Lambda, Thunk, Value}; use crate::warnings::{EvalWarning, WarningKind}; @@ -946,7 +947,7 @@ impl Compiler<'_> { if lambda.upvalue_count == 0 { self.emit_constant( if is_suspended_thunk { - Value::Thunk(Thunk::new_suspended(lambda, span)) + Value::Thunk(Thunk::new_suspended(lambda, LightSpan::new_actual(span))) } else { Value::Closure(Rc::new(Closure::new(lambda))) }, diff --git a/tvix/eval/src/spans.rs b/tvix/eval/src/spans.rs index 9998e438b2..d2a8e9badf 100644 --- a/tvix/eval/src/spans.rs +++ b/tvix/eval/src/spans.rs @@ -1,9 +1,46 @@ //! Utilities for dealing with span tracking in the compiler and in //! error reporting. +use crate::opcode::CodeIdx; +use crate::value::Lambda; use codemap::{File, Span}; use rnix::ast; use rowan::ast::AstNode; +use std::rc::Rc; + +/// Helper struct to carry information required for making a span, but +/// without actually performing the (expensive) span lookup. +/// +/// This is used for tracking spans across thunk boundaries, as they +/// are frequently instantiated but spans are only used in error or +/// warning cases. +#[derive(Clone, Debug)] +pub enum LightSpan { + /// The span has already been computed and can just be used right + /// away. + Actual { span: Span }, + + /// The span needs to be computed from the provided data, but only + /// when it is required. + Delayed { lambda: Rc<Lambda>, offset: CodeIdx }, +} + +impl LightSpan { + pub fn new_delayed(lambda: Rc<Lambda>, offset: CodeIdx) -> Self { + Self::Delayed { lambda, offset } + } + + pub fn new_actual(span: Span) -> Self { + Self::Actual { span } + } + + pub fn span(&self) -> Span { + match self { + LightSpan::Actual { span } => *span, + LightSpan::Delayed { lambda, offset } => lambda.chunk.get_span(*offset), + } + } +} /// Trait implemented by all types from which we can retrieve a span. pub trait ToSpan { diff --git a/tvix/eval/src/value/thunk.rs b/tvix/eval/src/value/thunk.rs index 420c5fe039..680cc9b1fb 100644 --- a/tvix/eval/src/value/thunk.rs +++ b/tvix/eval/src/value/thunk.rs @@ -24,11 +24,10 @@ use std::{ rc::Rc, }; -use codemap::Span; - use crate::{ chunk::Chunk, errors::{Error, ErrorKind}, + spans::LightSpan, upvalues::Upvalues, value::{Builtin, Closure}, vm::VM, @@ -49,7 +48,7 @@ enum ThunkRepr { Suspended { lambda: Rc<Lambda>, upvalues: Rc<Upvalues>, - span: Span, + light_span: LightSpan, }, /// Thunk currently under-evaluation; encountering a blackhole @@ -77,11 +76,11 @@ impl Thunk { ))))) } - pub fn new_suspended(lambda: Rc<Lambda>, span: Span) -> Self { + pub fn new_suspended(lambda: Rc<Lambda>, light_span: LightSpan) -> Self { Thunk(Rc::new(RefCell::new(ThunkRepr::Suspended { upvalues: Rc::new(Upvalues::with_capacity(lambda.upvalue_count)), lambda: lambda.clone(), - span, + light_span, }))) } @@ -124,7 +123,7 @@ impl Thunk { Thunk(Rc::new(RefCell::new(ThunkRepr::Suspended { lambda: Rc::new(lambda), upvalues: Rc::new(Upvalues::with_capacity(0)), - span: span, + light_span: LightSpan::new_actual(span), }))) } @@ -151,12 +150,16 @@ impl Thunk { if let ThunkRepr::Suspended { lambda, upvalues, - span, + light_span, } = std::mem::replace(&mut *thunk_mut, ThunkRepr::Blackhole) { drop(thunk_mut); - vm.enter_frame(lambda, upvalues, 0) - .map_err(|e| ErrorKind::ThunkForce(Box::new(Error { span, ..e })))?; + vm.enter_frame(lambda, upvalues, 0).map_err(|e| { + ErrorKind::ThunkForce(Box::new(Error { + span: light_span.span(), + ..e + })) + })?; (*self.0.borrow_mut()) = ThunkRepr::Evaluated(vm.pop()) } } diff --git a/tvix/eval/src/vm.rs b/tvix/eval/src/vm.rs index f0764c314f..37d30a6c01 100644 --- a/tvix/eval/src/vm.rs +++ b/tvix/eval/src/vm.rs @@ -10,6 +10,7 @@ use crate::{ nix_search_path::NixSearchPath, observer::RuntimeObserver, opcode::{CodeIdx, Count, JumpOffset, OpCode, StackIdx, UpvalueIdx}, + spans::LightSpan, unwrap_or_clone_rc, upvalues::Upvalues, value::{Builtin, Closure, CoercionKind, Lambda, NixAttrs, NixList, Thunk, Value}, @@ -211,6 +212,12 @@ impl<'o> VM<'o> { self.chunk().get_span(self.frame().ip - 1) } + /// Returns the information needed to calculate the current span, + /// but without performing that calculation. + fn current_light_span(&self) -> LightSpan { + LightSpan::new_delayed(self.frame().lambda.clone(), self.frame().ip - 1) + } + /// Construct an error from the given ErrorKind and the source /// span of the current instruction. pub fn error(&self, kind: ErrorKind) -> Error { @@ -884,7 +891,7 @@ impl<'o> VM<'o> { ); Thunk::new_closure(blueprint) } else { - Thunk::new_suspended(blueprint, self.current_span()) + Thunk::new_suspended(blueprint, self.current_light_span()) }; let upvalues = thunk.upvalues_mut(); self.push(Value::Thunk(thunk.clone())); |