diff options
Diffstat (limited to 'tvix/eval/src/errors.rs')
| -rw-r--r-- | tvix/eval/src/errors.rs | 129 |
1 files changed, 81 insertions, 48 deletions
diff --git a/tvix/eval/src/errors.rs b/tvix/eval/src/errors.rs index 2f00ecab85..de17f8d332 100644 --- a/tvix/eval/src/errors.rs +++ b/tvix/eval/src/errors.rs @@ -81,9 +81,13 @@ pub enum ErrorKind { ParseErrors(Vec<rnix::parser::ParseError>), - /// An error occured while forcing a thunk, and needs to be - /// chained up. - ThunkForce(Box<Error>), + /// An error occured while executing some native code (e.g. a + /// builtin), and needs to be chained up. + NativeError(Box<Error>), + + /// An error occured while executing Tvix bytecode, but needs to + /// be chained up. + BytecodeError(Box<Error>), /// Given type can't be coerced to a string in the respective context NotCoercibleToString { @@ -175,7 +179,7 @@ pub enum ErrorKind { impl error::Error for Error { fn source(&self) -> Option<&(dyn error::Error + 'static)> { match &self.kind { - ErrorKind::ThunkForce(err) => err.source(), + ErrorKind::NativeError(err) | ErrorKind::BytecodeError(err) => err.source(), ErrorKind::ParseErrors(err) => err.first().map(|e| e as &dyn error::Error), ErrorKind::ParseIntError(err) => Some(err), ErrorKind::ImportParseError { errors, .. } => { @@ -216,15 +220,6 @@ impl From<XmlError> for ErrorKind { } } -/// Implementation used if errors occur while forcing thunks (which -/// can potentially be threaded through a few contexts, i.e. nested -/// thunks). -impl From<Error> for ErrorKind { - fn from(e: Error) -> Self { - Self::ThunkForce(Box::new(e)) - } -} - impl From<io::Error> for ErrorKind { fn from(e: io::Error) -> Self { ErrorKind::IO { @@ -239,7 +234,7 @@ impl ErrorKind { pub fn is_catchable(&self) -> bool { match self { Self::Throw(_) | Self::AssertionFailed | Self::NixPathResolution(_) => true, - Self::ThunkForce(err) => err.kind.is_catchable(), + Self::NativeError(err) | Self::BytecodeError(err) => err.kind.is_catchable(), _ => false, } } @@ -361,10 +356,8 @@ to a missing value in the attribute set(s) included via `with`."#, // Errors themselves ignored here & handled in Self::spans instead ErrorKind::ParseErrors(_) => write!(f, "failed to parse Nix code:"), - // TODO(tazjin): trace through the whole chain of thunk - // forcing errors with secondary spans, instead of just - // delegating to the inner error - ErrorKind::ThunkForce(err) => write!(f, "{err}"), + ErrorKind::NativeError(_) => write!(f, "while evaluating this native code"), + ErrorKind::BytecodeError(_) => write!(f, "while evaluating this Nix code"), ErrorKind::NotCoercibleToString { kind, from } => { let kindly = match kind { @@ -757,7 +750,8 @@ impl Error { | ErrorKind::NotCallable(_) | ErrorKind::InfiniteRecursion | ErrorKind::ParseErrors(_) - | ErrorKind::ThunkForce(_) + | ErrorKind::NativeError(_) + | ErrorKind::BytecodeError(_) | ErrorKind::NotCoercibleToString { .. } | ErrorKind::NotAnAbsolutePath(_) | ErrorKind::ParseIntError(_) @@ -831,12 +825,9 @@ impl Error { // Placeholder error while Tvix is under construction. ErrorKind::NotImplemented(_) => "E999", - // TODO: thunk force errors should yield a chained - // diagnostic, but until then we just forward the error - // code from the inner error. - // - // The error code for thunk forces is E017. - ErrorKind::ThunkForce(ref err) => err.code(), + // Chained errors should yield the code of the innermost + // error. + ErrorKind::NativeError(ref err) | ErrorKind::BytecodeError(ref err) => err.code(), ErrorKind::WithContext { .. } => { panic!("internal ErrorKind::WithContext variant leaked") @@ -855,27 +846,6 @@ impl Error { spans_for_parse_errors(&file, errors) } - // Unwrap thunk errors to the innermost one - // TODO: limit the number of intermediates! - ErrorKind::ThunkForce(err) => { - let mut labels = err.spans(source); - - // Only add this thunk to the "cause chain" if it span isn't - // exactly identical to the next-higher level, which is very - // common for the last thunk in a chain. - if let Some(label) = labels.last() { - if label.span != self.span { - labels.push(SpanLabel { - label: Some("while evaluating this".into()), - span: self.span, - style: SpanStyle::Secondary, - }); - } - } - - labels - } - ErrorKind::UnexpectedArgument { formals_span, .. } => { vec![ SpanLabel { @@ -926,19 +896,82 @@ impl Error { /// any) of an error. fn diagnostics(&self, source: &SourceCode) -> Vec<Diagnostic> { match &self.kind { - ErrorKind::ThunkForce(err) => err.diagnostics(source), - ErrorKind::ImportCompilerError { errors, .. } => { let mut out = vec![self.diagnostic(source)]; out.extend(errors.iter().map(|e| e.diagnostic(source))); out } + // When encountering either of these error kinds, we are dealing + // with the top of an error chain. + // + // An error chain creates a list of diagnostics which provide trace + // information. + // + // We don't know how deep this chain is, so we avoid recursing in + // this function while unrolling the chain. + ErrorKind::NativeError(next) | ErrorKind::BytecodeError(next) => { + // Accumulated diagnostics to return. + let mut diagnostics: Vec<Diagnostic> = vec![]; + + // The next (inner) error to add to the diagnostics, after this + // one. + let mut next = *next.clone(); + + // Diagnostic message for *this* error. + let mut this_message = self.to_string(); + + // Primary span for *this* error. + let mut this_span = self.span; + + // Diagnostic spans for *this* error. + let mut this_spans = self.spans(source); + + loop { + if is_new_span( + this_span, + diagnostics.last().and_then(|last| last.spans.last()), + ) { + diagnostics.push(Diagnostic { + level: Level::Note, + message: this_message, + spans: this_spans, + code: None, // only the top-level error has one + }); + } + + this_message = next.to_string(); + this_span = next.span; + this_spans = next.spans(source); + + match next.kind { + ErrorKind::NativeError(inner) | ErrorKind::BytecodeError(inner) => { + next = *inner; + continue; + } + _ => { + diagnostics.extend(next.diagnostics(source)); + break; + } + } + } + + diagnostics + } + _ => vec![self.diagnostic(source)], } } } +// Check if this error is in a different span from its immediate ancestor. +fn is_new_span(this_span: Span, parent: Option<&SpanLabel>) -> bool { + match parent { + None => true, + Some(parent) => parent.span != this_span, + } +} + // Convenience methods to add context on other types. pub trait AddContext { /// Add context to the error-carrying type. |