Struct rustc_errors::DiagnosticBuilder

pub struct DiagnosticBuilder<'a> {
    handler: &'a Handler,
    diagnostic: Box<Diagnostic>,
}

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.

Fields

handler: &'a Handler

diagnostic: Box<Diagnostic>

Diagnostic is a large type, and DiagnosticBuilder is 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).

Implementations

impl<'a> DiagnosticBuilder<'a>

pub fn emit(&mut self)

Emit the diagnostic.

pub fn emit_unless(&mut self, delay: bool)

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 stash(self, span: Span, key: StashKey)

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 Handler::steal_diagnostic().

As with buffer, this is unless the handler has disabled such buffering.

pub fn into_diagnostic(self) -> Option<(Diagnostic, &'a Handler)>

Converts the builder to a Diagnostic for later emission, unless handler has disabled such buffering.

pub fn buffer(self, buffered_diagnostics: &mut Vec<Diagnostic>)

Buffers the diagnostic for later emission, unless handler has disabled such buffering.

pub fn delay_as_bug(&mut 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 span_label(&mut self, span: Span, label: impl Into<String>) -> &mut Self

Appends a labeled span to the diagnostic.

Labels are used to convey additional context for the diagnostic’s primary span. They will be shown together with the original diagnostic’s span, not with spans added by span_note, span_help, etc. Therefore, if the primary span is not displayable (because the span is DUMMY_SP or the source code isn’t found), labels will not be displayed either.

Implementation-wise, the label span is pushed onto the MultiSpan that was created when the diagnostic was constructed. However, the label span is not considered a “primary span”; only the Span supplied when creating the diagnostic is primary.

pub fn span_labels(
    &mut self,
    spans: impl IntoIterator<Item = Span>,
    label: impl AsRef<str>
) -> &mut Self

Labels all the given spans with the provided label. See Diagnostic::span_label() for more information.

pub fn note_expected_found(
    &mut self,
    expected_label: &dyn Display,
    expected: DiagnosticStyledString,
    found_label: &dyn Display,
    found: DiagnosticStyledString
) -> &mut Self

See Diagnostic::note_expected_found().

pub fn note_expected_found_extra(
    &mut self,
    expected_label: &dyn Display,
    expected: DiagnosticStyledString,
    found_label: &dyn Display,
    found: DiagnosticStyledString,
    expected_extra: &dyn Display,
    found_extra: &dyn Display
) -> &mut Self

See Diagnostic::note_expected_found_extra().

pub fn note_unsuccessful_coercion(
    &mut self,
    expected: DiagnosticStyledString,
    found: DiagnosticStyledString
) -> &mut Self

See Diagnostic::note_unsuccessful_coercion().

pub fn note(&mut self, msg: &str) -> &mut Self

See Diagnostic::note().

pub fn span_note<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self

See Diagnostic::span_note().

pub fn warn(&mut self, msg: &str) -> &mut Self

See Diagnostic::warn().

pub fn span_warn<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self

See Diagnostic::span_warn().

pub fn help(&mut self, msg: &str) -> &mut Self

See Diagnostic::help().

pub fn span_help<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self

See Diagnostic::span_help().

pub fn set_is_lint(&mut self) -> &mut Self

See Diagnostic::set_is_lint().

pub fn disable_suggestions(&mut self) -> &mut Self

See Diagnostic::disable_suggestions().

pub fn multipart_suggestion(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability
) -> &mut Self

See Diagnostic::multipart_suggestion().

pub fn multipart_suggestion_verbose(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability
) -> &mut Self

See Diagnostic::multipart_suggestion_verbose().

pub fn tool_only_multipart_suggestion(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability
) -> &mut Self

See Diagnostic::tool_only_multipart_suggestion().

pub fn span_suggestion(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

See Diagnostic::span_suggestion().

pub fn span_suggestions(
    &mut self,
    sp: Span,
    msg: &str,
    suggestions: impl Iterator<Item = String>,
    applicability: Applicability
) -> &mut Self

See Diagnostic::span_suggestions().

pub fn multipart_suggestions(
    &mut self,
    msg: &str,
    suggestions: impl Iterator<Item = Vec<(Span, String)>>,
    applicability: Applicability
) -> &mut Self

See Diagnostic::multipart_suggestions().

pub fn span_suggestion_short(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

See Diagnostic::span_suggestion_short().

pub fn span_suggestion_verbose(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

See Diagnostic::span_suggestion_verbose().

pub fn span_suggestion_hidden(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

See Diagnostic::span_suggestion_hidden().

pub fn tool_only_span_suggestion(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

See Diagnostic::tool_only_span_suggestion().

pub fn set_primary_message<M: Into<String>>(&mut self, msg: M) -> &mut Self

See Diagnostic::set_primary_message().

pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self

See Diagnostic::set_span().

pub fn code(&mut self, s: DiagnosticId) -> &mut Self

See Diagnostic::code().

pub(crate) fn new(
    handler: &'a Handler,
    level: Level,
    message: &str
) -> DiagnosticBuilder<'a>

Convenience function for internal use, clients should use one of the struct_* methods on Handler.

pub(crate) fn new_with_code(
    handler: &'a Handler,
    level: Level,
    code: Option<DiagnosticId>,
    message: &str
) -> DiagnosticBuilder<'a>

Convenience function for internal use, clients should use one of the struct_* methods on Handler.

pub(crate) fn new_diagnostic(
    handler: &'a Handler,
    diagnostic: Diagnostic
) -> DiagnosticBuilder<'a>

Creates a new DiagnosticBuilder with an already constructed diagnostic.

Methods from Deref<Target = Diagnostic>

pub fn is_error(&self) -> bool

pub fn has_future_breakage(&self) -> bool

pub fn is_force_warn(&self) -> bool

pub fn cancel(&mut self)

Cancel the diagnostic (a structured diagnostic must either be emitted or canceled or it will panic when dropped).

pub fn cancelled(&self) -> bool

Check if this diagnostic was cancelled.

pub fn span_label<T: Into<String>>(&mut self, span: Span, label: T) -> &mut Self

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”; only the Span supplied when creating the diagnostic is primary.

pub fn replace_span_with(&mut self, after: Span) -> &mut Self

pub(crate) fn note_expected_found(
    &mut self,
    expected_label: &dyn Display,
    expected: DiagnosticStyledString,
    found_label: &dyn Display,
    found: DiagnosticStyledString
) -> &mut Self

pub(crate) fn note_unsuccessful_coercion(
    &mut self,
    expected: DiagnosticStyledString,
    found: DiagnosticStyledString
) -> &mut Self

pub fn note_expected_found_extra(
    &mut self,
    expected_label: &dyn Display,
    expected: DiagnosticStyledString,
    found_label: &dyn Display,
    found: DiagnosticStyledString,
    expected_extra: &dyn Display,
    found_extra: &dyn Display
) -> &mut Self

pub fn note_trait_signature(
    &mut self,
    name: String,
    signature: String
) -> &mut Self

pub fn note(&mut self, msg: &str) -> &mut Self

Add a note attached to this diagnostic.

pub fn highlighted_note(&mut self, msg: Vec<(String, Style)>) -> &mut Self

pub(crate) fn span_note<S: Into<MultiSpan>>(
    &mut self,
    sp: S,
    msg: &str
) -> &mut Self

Prints the span with a note above it. This is like Diagnostic::note(), but it gets its own span.

pub(crate) fn warn(&mut self, msg: &str) -> &mut Self

Add a warning attached to this diagnostic.

pub(crate) fn span_warn<S: Into<MultiSpan>>(
    &mut self,
    sp: S,
    msg: &str
) -> &mut Self

Prints the span with a warning above it. This is like Diagnostic::warn(), but it gets its own span.

pub(crate) fn help(&mut self, msg: &str) -> &mut Self

Add a help message attached to this diagnostic.

pub(crate) fn span_help<S: Into<MultiSpan>>(
    &mut self,
    sp: S,
    msg: &str
) -> &mut Self

Prints the span with some help above it. This is like Diagnostic::help(), but it gets its own span.

pub fn disable_suggestions(&mut self) -> &mut Self

Disallow attaching suggestions this diagnostic. Any suggestions attached e.g. with the span_suggestion_* methods (before and after the call to disable_suggestions) will be ignored.

fn push_suggestion(&mut self, suggestion: CodeSuggestion)

Helper for pushing to self.suggestions, if available (not disable).

pub fn multipart_suggestion(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability
) -> &mut Self

Show a suggestion that has multiple parts to it. In other words, multiple changes need to be applied as part of this suggestion.

pub fn multipart_suggestion_verbose(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability
) -> &mut Self

Show a suggestion that has multiple parts to it, always as it’s own subdiagnostic. In other words, multiple changes need to be applied as part of this suggestion.

pub fn multipart_suggestion_with_style(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability,
    style: SuggestionStyle
) -> &mut Self

Diagnostic::multipart_suggestion() but you can set the SuggestionStyle.

pub fn tool_only_multipart_suggestion(
    &mut self,
    msg: &str,
    suggestion: Vec<(Span, String)>,
    applicability: Applicability
) -> &mut Self

Prints out a message with for a multipart suggestion without showing the suggested code.

This is intended to be used for suggestions that are obvious in what the changes need to be from the message, showing the span label inline would be visually unpleasant (marginally overlapping spans or multiline spans) and showing the snippet window wouldn’t improve understandability.

pub fn span_suggestion(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

Prints out a message with a suggested edit of the code.

In case of short messages and a simple suggestion, rustc displays it as a label:

try adding parentheses: `(tup.0).1`

The message

• should not end in any punctuation (a : is added automatically)
• should not be a question (avoid language like “did you mean”)
• should not contain any phrases like “the following”, “as shown”, etc.
• may look like “to do xyz, use” or “to do xyz, use abc”
• may contain a name of a function, variable, or type, but not whole expressions

See CodeSuggestion for more information.

pub fn span_suggestion_with_style(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability,
    style: SuggestionStyle
) -> &mut Self

Diagnostic::span_suggestion() but you can set the SuggestionStyle.

pub fn span_suggestion_verbose(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

Always show the suggested change.

pub fn span_suggestions(
    &mut self,
    sp: Span,
    msg: &str,
    suggestions: impl Iterator<Item = String>,
    applicability: Applicability
) -> &mut Self

Prints out a message with multiple suggested edits of the code. See also Diagnostic::span_suggestion().

pub fn multipart_suggestions(
    &mut self,
    msg: &str,
    suggestions: impl Iterator<Item = Vec<(Span, String)>>,
    applicability: Applicability
) -> &mut Self

Prints out a message with multiple suggested edits of the code. See also Diagnostic::span_suggestion().

pub fn span_suggestion_short(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

Prints out a message with a suggested edit of the code. If the suggestion is presented inline, it will only show the message and not the suggestion.

See CodeSuggestion for more information.

pub fn span_suggestion_hidden(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

Prints out a message for a suggestion without showing the suggested code.

This is intended to be used for suggestions that are obvious in what the changes need to be from the message, showing the span label inline would be visually unpleasant (marginally overlapping spans or multiline spans) and showing the snippet window wouldn’t improve understandability.

pub fn tool_only_span_suggestion(
    &mut self,
    sp: Span,
    msg: &str,
    suggestion: String,
    applicability: Applicability
) -> &mut Self

Adds a suggestion to the JSON output that will not be shown in the CLI.

This is intended to be used for suggestions that are very obvious in what the changes need to be from the message, but we still want other tools to be able to apply them.

pub fn tool_only_suggestion_with_metadata(
    &mut self,
    msg: &str,
    applicability: Applicability,
    tool_metadata: Json
)

Adds a suggestion intended only for a tool. The intent is that the metadata encodes the suggestion in a tool-specific way, as it may not even directly involve Rust code.

pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self

pub fn set_is_lint(&mut self) -> &mut Self

pub fn code(&mut self, s: DiagnosticId) -> &mut Self

pub fn clear_code(&mut self) -> &mut Self

pub fn get_code(&self) -> Option<DiagnosticId>

pub(crate) fn set_primary_message<M: Into<String>>(
    &mut self,
    msg: M
) -> &mut Self

pub fn message(&self) -> String

pub fn styled_message(&self) -> &Vec<(String, Style)>

pub fn sub(
    &mut self,
    level: Level,
    message: &str,
    span: MultiSpan,
    render_span: Option<MultiSpan>
)

Convenience function for internal use, clients should use one of the public methods above.

Used by proc_macro_server for implementing server::Diagnostic.

fn sub_with_highlights(
    &mut self,
    level: Level,
    message: Vec<(String, Style)>,
    span: MultiSpan,
    render_span: Option<MultiSpan>
)

Convenience function for internal use, clients should use one of the public methods above.

fn keys(
    &self
) -> (&Level, &Vec<(String, Style)>, &Option<DiagnosticId>, &MultiSpan, &Result<Vec<CodeSuggestion>, SuggestionsDisabled>, Option<&Vec<SubDiagnostic>>)

Fields used for Hash, and PartialEq trait

Trait Implementations

impl<'a> Clone for DiagnosticBuilder<'a>

fn clone(&self) -> DiagnosticBuilder<'a>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for DiagnosticBuilder<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Deref for DiagnosticBuilder<'a>

type Target = Diagnostic

The resulting type after dereferencing.

fn deref(&self) -> &Diagnostic

Dereferences the value.

impl<'a> DerefMut for DiagnosticBuilder<'a>

fn deref_mut(&mut self) -> &mut Diagnostic

Mutably dereferences the value.

impl<'a> Drop for DiagnosticBuilder<'a>

Destructor bomb - a DiagnosticBuilder must be either emitted or canceled or we emit a bug.

fn drop(&mut self)

Executes the destructor for this type.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 16 bytes