| use crate::{Applicability, Handler, Level, StashKey}; |
| use crate::{Diagnostic, DiagnosticId, DiagnosticStyledString}; |
| |
| use rustc_span::{MultiSpan, Span}; |
| use std::fmt::{self, Debug}; |
| use std::ops::{Deref, DerefMut}; |
| use std::thread::panicking; |
| use tracing::debug; |
| |
| /// Used for emitting structured error messages and other diagnostic information. |
| /// |
| /// If there is some state in a downstream crate you would like to |
| /// access in the methods of `DiagnosticBuilder` here, consider |
| /// extending `HandlerFlags`, accessed via `self.handler.flags`. |
| #[must_use] |
| #[derive(Clone)] |
| pub struct DiagnosticBuilder<'a>(Box<DiagnosticBuilderInner<'a>>); |
| |
| /// This is a large type, and often used as a return value, especially within |
| /// the frequently-used `PResult` type. In theory, return value optimization |
| /// (RVO) should avoid unnecessary copying. In practice, it does not (at the |
| /// time of writing). The split between `DiagnosticBuilder` and |
| /// `DiagnosticBuilderInner` exists to avoid many `memcpy` calls. |
| #[must_use] |
| #[derive(Clone)] |
| struct DiagnosticBuilderInner<'a> { |
| handler: &'a Handler, |
| diagnostic: Diagnostic, |
| allow_suggestions: bool, |
| } |
| |
| /// In general, the `DiagnosticBuilder` uses deref to allow access to |
| /// the fields and methods of the embedded `diagnostic` in a |
| /// transparent way. *However,* many of the methods are intended to |
| /// be used in a chained way, and hence ought to return `self`. In |
| /// that case, we can't just naively forward to the method on the |
| /// `diagnostic`, because the return type would be a `&Diagnostic` |
| /// instead of a `&DiagnosticBuilder<'a>`. This `forward!` macro makes |
| /// it easy to declare such methods on the builder. |
| macro_rules! forward { |
| // Forward pattern for &self -> &Self |
| ( |
| $(#[$attrs:meta])* |
| pub fn $n:ident(&self, $($name:ident: $ty:ty),* $(,)?) -> &Self |
| ) => { |
| $(#[$attrs])* |
| pub fn $n(&self, $($name: $ty),*) -> &Self { |
| self.diagnostic.$n($($name),*); |
| self |
| } |
| }; |
| |
| // Forward pattern for &mut self -> &mut Self |
| ( |
| $(#[$attrs:meta])* |
| pub fn $n:ident(&mut self, $($name:ident: $ty:ty),* $(,)?) -> &mut Self |
| ) => { |
| $(#[$attrs])* |
| pub fn $n(&mut self, $($name: $ty),*) -> &mut Self { |
| self.0.diagnostic.$n($($name),*); |
| self |
| } |
| }; |
| |
| // Forward pattern for &mut self -> &mut Self, with S: Into<MultiSpan> |
| // type parameter. No obvious way to make this more generic. |
| ( |
| $(#[$attrs:meta])* |
| pub fn $n:ident<S: Into<MultiSpan>>( |
| &mut self, |
| $($name:ident: $ty:ty),* |
| $(,)? |
| ) -> &mut Self |
| ) => { |
| $(#[$attrs])* |
| pub fn $n<S: Into<MultiSpan>>(&mut self, $($name: $ty),*) -> &mut Self { |
| self.0.diagnostic.$n($($name),*); |
| self |
| } |
| }; |
| } |
| |
| impl<'a> Deref for DiagnosticBuilder<'a> { |
| type Target = Diagnostic; |
| |
| fn deref(&self) -> &Diagnostic { |
| &self.0.diagnostic |
| } |
| } |
| |
| impl<'a> DerefMut for DiagnosticBuilder<'a> { |
| fn deref_mut(&mut self) -> &mut Diagnostic { |
| &mut self.0.diagnostic |
| } |
| } |
| |
| impl<'a> DiagnosticBuilder<'a> { |
| /// Emit the diagnostic. |
| pub fn emit(&mut self) { |
| self.0.handler.emit_diagnostic(&self); |
| self.cancel(); |
| } |
| |
| /// Emit the diagnostic unless `delay` is true, |
| /// in which case the emission will be delayed as a bug. |
| /// |
| /// See `emit` and `delay_as_bug` for details. |
| pub fn emit_unless(&mut self, delay: bool) { |
| if delay { |
| self.delay_as_bug(); |
| } else { |
| self.emit(); |
| } |
| } |
| |
| /// Stashes diagnostic for possible later improvement in a different, |
| /// later stage of the compiler. The diagnostic can be accessed with |
| /// the provided `span` and `key` through `.steal_diagnostic` on `Handler`. |
| /// |
| /// As with `buffer`, this is unless the handler has disabled such buffering. |
| pub fn stash(self, span: Span, key: StashKey) { |
| if let Some((diag, handler)) = self.into_diagnostic() { |
| handler.stash_diagnostic(span, key, diag); |
| } |
| } |
| |
| /// Converts the builder to a `Diagnostic` for later emission, |
| /// unless handler has disabled such buffering. |
| pub fn into_diagnostic(mut self) -> Option<(Diagnostic, &'a Handler)> { |
| if self.0.handler.flags.dont_buffer_diagnostics |
| || self.0.handler.flags.treat_err_as_bug.is_some() |
| { |
| self.emit(); |
| return None; |
| } |
| |
| let handler = self.0.handler; |
| |
| // We must use `Level::Cancelled` for `dummy` to avoid an ICE about an |
| // unused diagnostic. |
| let dummy = Diagnostic::new(Level::Cancelled, ""); |
| let diagnostic = std::mem::replace(&mut self.0.diagnostic, dummy); |
| |
| // Logging here is useful to help track down where in logs an error was |
| // actually emitted. |
| debug!("buffer: diagnostic={:?}", diagnostic); |
| |
| Some((diagnostic, handler)) |
| } |
| |
| /// Buffers the diagnostic for later emission, |
| /// unless handler has disabled such buffering. |
| pub fn buffer(self, buffered_diagnostics: &mut Vec<Diagnostic>) { |
| buffered_diagnostics.extend(self.into_diagnostic().map(|(diag, _)| diag)); |
| } |
| |
| /// Convenience function for internal use, clients should use one of the |
| /// span_* methods instead. |
| pub fn sub<S: Into<MultiSpan>>( |
| &mut self, |
| level: Level, |
| message: &str, |
| span: Option<S>, |
| ) -> &mut Self { |
| let span = span.map(|s| s.into()).unwrap_or_else(MultiSpan::new); |
| self.0.diagnostic.sub(level, message, span, None); |
| self |
| } |
| |
| /// Delay emission of this diagnostic as a bug. |
| /// |
| /// This can be useful in contexts where an error indicates a bug but |
| /// typically this only happens when other compilation errors have already |
| /// happened. In those cases this can be used to defer emission of this |
| /// diagnostic as a bug in the compiler only if no other errors have been |
| /// emitted. |
| /// |
| /// In the meantime, though, callsites are required to deal with the "bug" |
| /// locally in whichever way makes the most sense. |
| pub fn delay_as_bug(&mut self) { |
| self.level = Level::Bug; |
| self.0.handler.delay_as_bug(self.0.diagnostic.clone()); |
| self.cancel(); |
| } |
| |
| /// Adds a span/label to be included in the resulting snippet. |
| /// |
| /// This is pushed onto the [`MultiSpan`] that was created when the diagnostic |
| /// was first built. That means it will be shown together with the original |
| /// span/label, *not* a span added by one of the `span_{note,warn,help,suggestions}` methods. |
| /// |
| /// This span is *not* considered a ["primary span"][`MultiSpan`]; only |
| /// the `Span` supplied when creating the diagnostic is primary. |
| /// |
| /// [`MultiSpan`]: ../rustc_span/struct.MultiSpan.html |
| pub fn span_label(&mut self, span: Span, label: impl Into<String>) -> &mut Self { |
| self.0.diagnostic.span_label(span, label); |
| self |
| } |
| |
| /// Labels all the given spans with the provided label. |
| /// See `span_label` for more information. |
| pub fn span_labels( |
| &mut self, |
| spans: impl IntoIterator<Item = Span>, |
| label: impl AsRef<str>, |
| ) -> &mut Self { |
| let label = label.as_ref(); |
| for span in spans { |
| self.0.diagnostic.span_label(span, label); |
| } |
| self |
| } |
| |
| forward!(pub fn note_expected_found( |
| &mut self, |
| expected_label: &dyn fmt::Display, |
| expected: DiagnosticStyledString, |
| found_label: &dyn fmt::Display, |
| found: DiagnosticStyledString, |
| ) -> &mut Self); |
| |
| forward!(pub fn note_expected_found_extra( |
| &mut self, |
| expected_label: &dyn fmt::Display, |
| expected: DiagnosticStyledString, |
| found_label: &dyn fmt::Display, |
| found: DiagnosticStyledString, |
| expected_extra: &dyn fmt::Display, |
| found_extra: &dyn fmt::Display, |
| ) -> &mut Self); |
| |
| forward!(pub fn note_unsuccessfull_coercion( |
| &mut self, |
| expected: DiagnosticStyledString, |
| found: DiagnosticStyledString, |
| ) -> &mut Self); |
| |
| forward!(pub fn note(&mut self, msg: &str) -> &mut Self); |
| forward!(pub fn span_note<S: Into<MultiSpan>>( |
| &mut self, |
| sp: S, |
| msg: &str, |
| ) -> &mut Self); |
| forward!(pub fn warn(&mut self, msg: &str) -> &mut Self); |
| forward!(pub fn span_warn<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self); |
| forward!(pub fn help(&mut self, msg: &str) -> &mut Self); |
| forward!(pub fn span_help<S: Into<MultiSpan>>( |
| &mut self, |
| sp: S, |
| msg: &str, |
| ) -> &mut Self); |
| |
| pub fn multipart_suggestion( |
| &mut self, |
| msg: &str, |
| suggestion: Vec<(Span, String)>, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.multipart_suggestion(msg, suggestion, applicability); |
| self |
| } |
| |
| pub fn multipart_suggestions( |
| &mut self, |
| msg: &str, |
| suggestions: Vec<Vec<(Span, String)>>, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.multipart_suggestions(msg, suggestions, applicability); |
| self |
| } |
| |
| pub fn tool_only_multipart_suggestion( |
| &mut self, |
| msg: &str, |
| suggestion: Vec<(Span, String)>, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.tool_only_multipart_suggestion(msg, suggestion, applicability); |
| self |
| } |
| |
| pub fn span_suggestion( |
| &mut self, |
| sp: Span, |
| msg: &str, |
| suggestion: String, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.span_suggestion(sp, msg, suggestion, applicability); |
| self |
| } |
| |
| pub fn span_suggestions( |
| &mut self, |
| sp: Span, |
| msg: &str, |
| suggestions: impl Iterator<Item = String>, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.span_suggestions(sp, msg, suggestions, applicability); |
| self |
| } |
| |
| pub fn span_suggestion_short( |
| &mut self, |
| sp: Span, |
| msg: &str, |
| suggestion: String, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.span_suggestion_short(sp, msg, suggestion, applicability); |
| self |
| } |
| |
| pub fn span_suggestion_verbose( |
| &mut self, |
| sp: Span, |
| msg: &str, |
| suggestion: String, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.span_suggestion_verbose(sp, msg, suggestion, applicability); |
| self |
| } |
| |
| pub fn span_suggestion_hidden( |
| &mut self, |
| sp: Span, |
| msg: &str, |
| suggestion: String, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.span_suggestion_hidden(sp, msg, suggestion, applicability); |
| self |
| } |
| |
| pub fn tool_only_span_suggestion( |
| &mut self, |
| sp: Span, |
| msg: &str, |
| suggestion: String, |
| applicability: Applicability, |
| ) -> &mut Self { |
| if !self.0.allow_suggestions { |
| return self; |
| } |
| self.0.diagnostic.tool_only_span_suggestion(sp, msg, suggestion, applicability); |
| self |
| } |
| |
| forward!(pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self); |
| forward!(pub fn code(&mut self, s: DiagnosticId) -> &mut Self); |
| |
| pub fn allow_suggestions(&mut self, allow: bool) -> &mut Self { |
| self.0.allow_suggestions = allow; |
| self |
| } |
| |
| /// Convenience function for internal use, clients should use one of the |
| /// struct_* methods on Handler. |
| crate fn new(handler: &'a Handler, level: Level, message: &str) -> DiagnosticBuilder<'a> { |
| DiagnosticBuilder::new_with_code(handler, level, None, message) |
| } |
| |
| /// Convenience function for internal use, clients should use one of the |
| /// struct_* methods on Handler. |
| crate fn new_with_code( |
| handler: &'a Handler, |
| level: Level, |
| code: Option<DiagnosticId>, |
| message: &str, |
| ) -> DiagnosticBuilder<'a> { |
| let diagnostic = Diagnostic::new_with_code(level, code, message); |
| DiagnosticBuilder::new_diagnostic(handler, diagnostic) |
| } |
| |
| /// Creates a new `DiagnosticBuilder` with an already constructed |
| /// diagnostic. |
| crate fn new_diagnostic(handler: &'a Handler, diagnostic: Diagnostic) -> DiagnosticBuilder<'a> { |
| debug!("Created new diagnostic"); |
| DiagnosticBuilder(Box::new(DiagnosticBuilderInner { |
| handler, |
| diagnostic, |
| allow_suggestions: true, |
| })) |
| } |
| } |
| |
| impl<'a> Debug for DiagnosticBuilder<'a> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| self.0.diagnostic.fmt(f) |
| } |
| } |
| |
| /// Destructor bomb - a `DiagnosticBuilder` must be either emitted or canceled |
| /// or we emit a bug. |
| impl<'a> Drop for DiagnosticBuilder<'a> { |
| fn drop(&mut self) { |
| if !panicking() && !self.cancelled() { |
| let mut db = DiagnosticBuilder::new( |
| self.0.handler, |
| Level::Bug, |
| "the following error was constructed but not emitted", |
| ); |
| db.emit(); |
| self.emit(); |
| panic!(); |
| } |
| } |
| } |
| |
| #[macro_export] |
| macro_rules! struct_span_err { |
| ($session:expr, $span:expr, $code:ident, $($message:tt)*) => ({ |
| $session.struct_span_err_with_code( |
| $span, |
| &format!($($message)*), |
| $crate::error_code!($code), |
| ) |
| }) |
| } |
| |
| #[macro_export] |
| macro_rules! error_code { |
| ($code:ident) => {{ $crate::DiagnosticId::Error(stringify!($code).to_owned()) }}; |
| } |
