diff options
Diffstat (limited to 'compiler/rustc_errors/src')
| -rw-r--r-- | compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs | 180 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/diagnostic.rs | 586 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/diagnostic_builder.rs | 452 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/emitter.rs | 2177 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/json.rs | 446 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/json/tests.rs | 204 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/lib.rs | 1021 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/lock.rs | 93 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/registry.rs | 29 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/snippet.rs | 190 | ||||
| -rw-r--r-- | compiler/rustc_errors/src/styled_buffer.rs | 151 |
11 files changed, 5529 insertions, 0 deletions
diff --git a/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs b/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs new file mode 100644 index 00000000000..265ba59cccb --- /dev/null +++ b/compiler/rustc_errors/src/annotate_snippet_emitter_writer.rs @@ -0,0 +1,180 @@ +//! Emit diagnostics using the `annotate-snippets` library +//! +//! This is the equivalent of `./emitter.rs` but making use of the +//! [`annotate-snippets`][annotate_snippets] library instead of building the output ourselves. +//! +//! [annotate_snippets]: https://docs.rs/crate/annotate-snippets/ + +use crate::emitter::FileWithAnnotatedLines; +use crate::snippet::Line; +use crate::{CodeSuggestion, Diagnostic, DiagnosticId, Emitter, Level, SubDiagnostic}; +use annotate_snippets::display_list::{DisplayList, FormatOptions}; +use annotate_snippets::snippet::*; +use rustc_data_structures::sync::Lrc; +use rustc_span::source_map::SourceMap; +use rustc_span::{MultiSpan, SourceFile}; + +/// Generates diagnostics using annotate-snippet +pub struct AnnotateSnippetEmitterWriter { + source_map: Option<Lrc<SourceMap>>, + /// If true, hides the longer explanation text + short_message: bool, + /// If true, will normalize line numbers with `LL` to prevent noise in UI test diffs. + ui_testing: bool, + + macro_backtrace: bool, +} + +impl Emitter for AnnotateSnippetEmitterWriter { + /// The entry point for the diagnostics generation + fn emit_diagnostic(&mut self, diag: &Diagnostic) { + let mut children = diag.children.clone(); + let (mut primary_span, suggestions) = self.primary_span_formatted(&diag); + + self.fix_multispans_in_extern_macros_and_render_macro_backtrace( + &self.source_map, + &mut primary_span, + &mut children, + &diag.level, + self.macro_backtrace, + ); + + self.emit_messages_default( + &diag.level, + diag.message(), + &diag.code, + &primary_span, + &children, + &suggestions, + ); + } + + fn source_map(&self) -> Option<&Lrc<SourceMap>> { + self.source_map.as_ref() + } + + fn should_show_explain(&self) -> bool { + !self.short_message + } +} + +/// Provides the source string for the given `line` of `file` +fn source_string(file: Lrc<SourceFile>, line: &Line) -> String { + file.get_line(line.line_index - 1).map(|a| a.to_string()).unwrap_or_default() +} + +/// Maps `Diagnostic::Level` to `snippet::AnnotationType` +fn annotation_type_for_level(level: Level) -> AnnotationType { + match level { + Level::Bug | Level::Fatal | Level::Error => AnnotationType::Error, + Level::Warning => AnnotationType::Warning, + Level::Note => AnnotationType::Note, + Level::Help => AnnotationType::Help, + // FIXME(#59346): Not sure how to map these two levels + Level::Cancelled | Level::FailureNote => AnnotationType::Error, + } +} + +impl AnnotateSnippetEmitterWriter { + pub fn new( + source_map: Option<Lrc<SourceMap>>, + short_message: bool, + macro_backtrace: bool, + ) -> Self { + Self { source_map, short_message, ui_testing: false, macro_backtrace } + } + + /// Allows to modify `Self` to enable or disable the `ui_testing` flag. + /// + /// If this is set to true, line numbers will be normalized as `LL` in the output. + pub fn ui_testing(mut self, ui_testing: bool) -> Self { + self.ui_testing = ui_testing; + self + } + + fn emit_messages_default( + &mut self, + level: &Level, + message: String, + code: &Option<DiagnosticId>, + msp: &MultiSpan, + _children: &[SubDiagnostic], + _suggestions: &[CodeSuggestion], + ) { + if let Some(source_map) = &self.source_map { + // Make sure our primary file comes first + let primary_lo = if let Some(ref primary_span) = msp.primary_span().as_ref() { + if primary_span.is_dummy() { + // FIXME(#59346): Not sure when this is the case and what + // should be done if it happens + return; + } else { + source_map.lookup_char_pos(primary_span.lo()) + } + } else { + // FIXME(#59346): Not sure when this is the case and what + // should be done if it happens + return; + }; + let mut annotated_files = + FileWithAnnotatedLines::collect_annotations(msp, &self.source_map); + if let Ok(pos) = + annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) + { + annotated_files.swap(0, pos); + } + // owned: line source, line index, annotations + type Owned = (String, usize, Vec<crate::snippet::Annotation>); + let origin = primary_lo.file.name.to_string(); + let annotated_files: Vec<Owned> = annotated_files + .into_iter() + .flat_map(|annotated_file| { + let file = annotated_file.file; + annotated_file + .lines + .into_iter() + .map(|line| { + (source_string(file.clone(), &line), line.line_index, line.annotations) + }) + .collect::<Vec<Owned>>() + }) + .collect(); + let snippet = Snippet { + title: Some(Annotation { + label: Some(&message), + id: code.as_ref().map(|c| match c { + DiagnosticId::Error(val) | DiagnosticId::Lint(val) => val.as_str(), + }), + annotation_type: annotation_type_for_level(*level), + }), + footer: vec![], + opt: FormatOptions { color: true, anonymized_line_numbers: self.ui_testing }, + slices: annotated_files + .iter() + .map(|(source, line_index, annotations)| { + Slice { + source, + line_start: *line_index, + origin: Some(&origin), + // FIXME(#59346): Not really sure when `fold` should be true or false + fold: false, + annotations: annotations + .iter() + .map(|annotation| SourceAnnotation { + range: (annotation.start_col, annotation.end_col), + label: annotation.label.as_deref().unwrap_or_default(), + annotation_type: annotation_type_for_level(*level), + }) + .collect(), + } + }) + .collect(), + }; + // FIXME(#59346): Figure out if we can _always_ print to stderr or not. + // `emitter.rs` has the `Destination` enum that lists various possible output + // destinations. + eprintln!("{}", DisplayList::from(snippet)) + } + // FIXME(#59346): Is it ok to return None if there's no source_map? + } +} diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs new file mode 100644 index 00000000000..870f7b81e21 --- /dev/null +++ b/compiler/rustc_errors/src/diagnostic.rs @@ -0,0 +1,586 @@ +use crate::snippet::Style; +use crate::Applicability; +use crate::CodeSuggestion; +use crate::Level; +use crate::Substitution; +use crate::SubstitutionPart; +use crate::SuggestionStyle; +use rustc_span::{MultiSpan, Span, DUMMY_SP}; +use std::fmt; + +#[must_use] +#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +pub struct Diagnostic { + pub level: Level, + pub message: Vec<(String, Style)>, + pub code: Option<DiagnosticId>, + pub span: MultiSpan, + pub children: Vec<SubDiagnostic>, + pub suggestions: Vec<CodeSuggestion>, + + /// This is not used for highlighting or rendering any error message. Rather, it can be used + /// as a sort key to sort a buffer of diagnostics. By default, it is the primary span of + /// `span` if there is one. Otherwise, it is `DUMMY_SP`. + pub sort_span: Span, +} + +#[derive(Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)] +pub enum DiagnosticId { + Error(String), + Lint(String), +} + +/// For example a note attached to an error. +#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +pub struct SubDiagnostic { + pub level: Level, + pub message: Vec<(String, Style)>, + pub span: MultiSpan, + pub render_span: Option<MultiSpan>, +} + +#[derive(Debug, PartialEq, Eq)] +pub struct DiagnosticStyledString(pub Vec<StringPart>); + +impl DiagnosticStyledString { + pub fn new() -> DiagnosticStyledString { + DiagnosticStyledString(vec![]) + } + pub fn push_normal<S: Into<String>>(&mut self, t: S) { + self.0.push(StringPart::Normal(t.into())); + } + pub fn push_highlighted<S: Into<String>>(&mut self, t: S) { + self.0.push(StringPart::Highlighted(t.into())); + } + pub fn push<S: Into<String>>(&mut self, t: S, highlight: bool) { + if highlight { + self.push_highlighted(t); + } else { + self.push_normal(t); + } + } + pub fn normal<S: Into<String>>(t: S) -> DiagnosticStyledString { + DiagnosticStyledString(vec![StringPart::Normal(t.into())]) + } + + pub fn highlighted<S: Into<String>>(t: S) -> DiagnosticStyledString { + DiagnosticStyledString(vec![StringPart::Highlighted(t.into())]) + } + + pub fn content(&self) -> String { + self.0.iter().map(|x| x.content()).collect::<String>() + } +} + +#[derive(Debug, PartialEq, Eq)] +pub enum StringPart { + Normal(String), + Highlighted(String), +} + +impl StringPart { + pub fn content(&self) -> &str { + match self { + &StringPart::Normal(ref s) | &StringPart::Highlighted(ref s) => s, + } + } +} + +impl Diagnostic { + pub fn new(level: Level, message: &str) -> Self { + Diagnostic::new_with_code(level, None, message) + } + + pub fn new_with_code(level: Level, code: Option<DiagnosticId>, message: &str) -> Self { + Diagnostic { + level, + message: vec![(message.to_owned(), Style::NoStyle)], + code, + span: MultiSpan::new(), + children: vec![], + suggestions: vec![], + sort_span: DUMMY_SP, + } + } + + pub fn is_error(&self) -> bool { + match self.level { + Level::Bug | Level::Fatal | Level::Error | Level::FailureNote => true, + + Level::Warning | Level::Note | Level::Help | Level::Cancelled => false, + } + } + + /// Cancel the diagnostic (a structured diagnostic must either be emitted or + /// canceled or it will panic when dropped). + pub fn cancel(&mut self) { + self.level = Level::Cancelled; + } + + pub fn cancelled(&self) -> bool { + self.level == Level::Cancelled + } + + /// Set the sorting span. + pub fn set_sort_span(&mut self, sp: Span) { + self.sort_span = sp; + } + + /// 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<T: Into<String>>(&mut self, span: Span, label: T) -> &mut Self { + self.span.push_span_label(span, label.into()); + self + } + + pub fn replace_span_with(&mut self, after: Span) -> &mut Self { + let before = self.span.clone(); + self.set_span(after); + for span_label in before.span_labels() { + if let Some(label) = span_label.label { + self.span_label(after, label); + } + } + self + } + + pub fn note_expected_found( + &mut self, + expected_label: &dyn fmt::Display, + expected: DiagnosticStyledString, + found_label: &dyn fmt::Display, + found: DiagnosticStyledString, + ) -> &mut Self { + self.note_expected_found_extra(expected_label, expected, found_label, found, &"", &"") + } + + pub fn note_unsuccessfull_coercion( + &mut self, + expected: DiagnosticStyledString, + found: DiagnosticStyledString, + ) -> &mut Self { + let mut msg: Vec<_> = + vec![("required when trying to coerce from type `".to_string(), Style::NoStyle)]; + msg.extend(expected.0.iter().map(|x| match *x { + StringPart::Normal(ref s) => (s.to_owned(), Style::NoStyle), + StringPart::Highlighted(ref s) => (s.to_owned(), Style::Highlight), + })); + msg.push(("` to type '".to_string(), Style::NoStyle)); + msg.extend(found.0.iter().map(|x| match *x { + StringPart::Normal(ref s) => (s.to_owned(), Style::NoStyle), + StringPart::Highlighted(ref s) => (s.to_owned(), Style::Highlight), + })); + msg.push(("`".to_string(), Style::NoStyle)); + + // For now, just attach these as notes + self.highlighted_note(msg); + self + } + + 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 { + let expected_label = expected_label.to_string(); + let expected_label = if expected_label.is_empty() { + "expected".to_string() + } else { + format!("expected {}", expected_label) + }; + let found_label = found_label.to_string(); + let found_label = if found_label.is_empty() { + "found".to_string() + } else { + format!("found {}", found_label) + }; + let (found_padding, expected_padding) = if expected_label.len() > found_label.len() { + (expected_label.len() - found_label.len(), 0) + } else { + (0, found_label.len() - expected_label.len()) + }; + let mut msg: Vec<_> = + vec![(format!("{}{} `", " ".repeat(expected_padding), expected_label), Style::NoStyle)]; + msg.extend(expected.0.iter().map(|x| match *x { + StringPart::Normal(ref s) => (s.to_owned(), Style::NoStyle), + StringPart::Highlighted(ref s) => (s.to_owned(), Style::Highlight), + })); + msg.push((format!("`{}\n", expected_extra), Style::NoStyle)); + msg.push((format!("{}{} `", " ".repeat(found_padding), found_label), Style::NoStyle)); + msg.extend(found.0.iter().map(|x| match *x { + StringPart::Normal(ref s) => (s.to_owned(), Style::NoStyle), + StringPart::Highlighted(ref s) => (s.to_owned(), Style::Highlight), + })); + msg.push((format!("`{}", found_extra), Style::NoStyle)); + + // For now, just attach these as notes. + self.highlighted_note(msg); + self + } + + pub fn note_trait_signature(&mut self, name: String, signature: String) -> &mut Self { + self.highlighted_note(vec![ + (format!("`{}` from trait: `", name), Style::NoStyle), + (signature, Style::Highlight), + ("`".to_string(), Style::NoStyle), + ]); + self + } + + pub fn note(&mut self, msg: &str) -> &mut Self { + self.sub(Level::Note, msg, MultiSpan::new(), None); + self + } + + pub fn highlighted_note(&mut self, msg: Vec<(String, Style)>) -> &mut Self { + self.sub_with_highlights(Level::Note, msg, MultiSpan::new(), None); + self + } + + /// Prints the span with a note above it. + pub fn span_note<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self { + self.sub(Level::Note, msg, sp.into(), None); + self + } + + pub fn warn(&mut self, msg: &str) -> &mut Self { + self.sub(Level::Warning, msg, MultiSpan::new(), None); + self + } + + /// Prints the span with a warn above it. + pub fn span_warn<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self { + self.sub(Level::Warning, msg, sp.into(), None); + self + } + + pub fn help(&mut self, msg: &str) -> &mut Self { + self.sub(Level::Help, msg, MultiSpan::new(), None); + self + } + + /// Prints the span with some help above it. + pub fn span_help<S: Into<MultiSpan>>(&mut self, sp: S, msg: &str) -> &mut Self { + self.sub(Level::Help, msg, sp.into(), None); + self + } + + pub fn multipart_suggestion( + &mut self, + msg: &str, + suggestion: Vec<(Span, String)>, + applicability: Applicability, + ) -> &mut Self { + self.suggestions.push(CodeSuggestion { + substitutions: vec![Substitution { + parts: suggestion + .into_iter() + .map(|(span, snippet)| SubstitutionPart { snippet, span }) + .collect(), + }], + msg: msg.to_owned(), + style: SuggestionStyle::ShowCode, + applicability, + }); + self + } + + pub fn multipart_suggestions( + &mut self, + msg: &str, + suggestions: Vec<Vec<(Span, String)>>, + applicability: Applicability, + ) -> &mut Self { + self.suggestions.push(CodeSuggestion { + substitutions: suggestions + .into_iter() + .map(|suggestion| Substitution { + parts: suggestion + .into_iter() + .map(|(span, snippet)| SubstitutionPart { snippet, span }) + .collect(), + }) + .collect(), + msg: msg.to_owned(), + style: SuggestionStyle::ShowCode, + applicability, + }); + 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 tool_only_multipart_suggestion( + &mut self, + msg: &str, + suggestion: Vec<(Span, String)>, + applicability: Applicability, + ) -> &mut Self { + self.suggestions.push(CodeSuggestion { + substitutions: vec![Substitution { + parts: suggestion + .into_iter() + .map(|(span, snippet)| SubstitutionPart { snippet, span }) + .collect(), + }], + msg: msg.to_owned(), + style: SuggestionStyle::CompletelyHidden, + applicability, + }); + 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: + /// + /// ```text + /// 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( + &mut self, + sp: Span, + msg: &str, + suggestion: String, + applicability: Applicability, + ) -> &mut Self { + self.span_suggestion_with_style( + sp, + msg, + suggestion, + applicability, + SuggestionStyle::ShowCode, + ); + self + } + + pub fn span_suggestion_with_style( + &mut self, + sp: Span, + msg: &str, + suggestion: String, + applicability: Applicability, + style: SuggestionStyle, + ) -> &mut Self { + self.suggestions.push(CodeSuggestion { + substitutions: vec![Substitution { + parts: vec![SubstitutionPart { snippet: suggestion, span: sp }], + }], + msg: msg.to_owned(), + style, + applicability, + }); + self + } + + pub fn span_suggestion_verbose( + &mut self, + sp: Span, + msg: &str, + suggestion: String, + applicability: Applicability, + ) -> &mut Self { + self.span_suggestion_with_style( + sp, + msg, + suggestion, + applicability, + SuggestionStyle::ShowAlways, + ); + self + } + + /// Prints out a message with multiple suggested edits of the code. + pub fn span_suggestions( + &mut self, + sp: Span, + msg: &str, + suggestions: impl Iterator<Item = String>, + applicability: Applicability, + ) -> &mut Self { + self.suggestions.push(CodeSuggestion { + substitutions: suggestions + .map(|snippet| Substitution { parts: vec![SubstitutionPart { snippet, span: sp }] }) + .collect(), + msg: msg.to_owned(), + style: SuggestionStyle::ShowCode, + applicability, + }); + 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_short( + &mut self, + sp: Span, + msg: &str, + suggestion: String, + applicability: Applicability, + ) -> &mut Self { + self.span_suggestion_with_style( + sp, + msg, + suggestion, + applicability, + SuggestionStyle::HideCodeInline, + ); + self + } + + /// Prints out a message with 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 span_suggestion_hidden( + &mut self, + sp: Span, + msg: &str, + suggestion: String, + applicability: Applicability, + ) -> &mut Self { + self.span_suggestion_with_style( + sp, + msg, + suggestion, + applicability, + SuggestionStyle::HideCodeAlways, + ); + self + } + + /// Adds a suggestion to the json output, but otherwise remains silent/undisplayed 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_span_suggestion( + &mut self, + sp: Span, + msg: &str, + suggestion: String, + applicability: Applicability, + ) -> &mut Self { + self.span_suggestion_with_style( + sp, + msg, + suggestion, + applicability, + SuggestionStyle::CompletelyHidden, + ); + self + } + + pub fn set_span<S: Into<MultiSpan>>(&mut self, sp: S) -> &mut Self { + self.span = sp.into(); + if let Some(span) = self.span.primary_span() { + self.sort_span = span; + } + self + } + + pub fn code(&mut self, s: DiagnosticId) -> &mut Self { + self.code = Some(s); + self + } + + pub fn clear_code(&mut self) -> &mut Self { + self.code = None; + self + } + + pub fn get_code(&self) -> Option<DiagnosticId> { + self.code.clone() + } + + pub fn set_primary_message<M: Into<String>>(&mut self, msg: M) -> &mut Self { + self.message[0] = (msg.into(), Style::NoStyle); + self + } + + pub fn message(&self) -> String { + self.message.iter().map(|i| i.0.as_str()).collect::<String>() + } + + pub fn styled_message(&self) -> &Vec<(String, Style)> { + &self.message + } + + /// Used by a lint. Copies over all details *but* the "main + /// message". + pub fn copy_details_not_message(&mut self, from: &Diagnostic) { + self.span = from.span.clone(); + self.code = from.code.clone(); + self.children.extend(from.children.iter().cloned()) + } + + /// Convenience function for internal use, clients should use one of the + /// public methods above. + pub fn sub( + &mut self, + level: Level, + message: &str, + span: MultiSpan, + render_span: Option<MultiSpan>, + ) { + let sub = SubDiagnostic { + level, + message: vec![(message.to_owned(), Style::NoStyle)], + span, + render_span, + }; + self.children.push(sub); + } + + /// Convenience function for internal use, clients should use one of the + /// public methods above. + fn sub_with_highlights( + &mut self, + level: Level, + message: Vec<(String, Style)>, + span: MultiSpan, + render_span: Option<MultiSpan>, + ) { + let sub = SubDiagnostic { level, message, span, render_span }; + self.children.push(sub); + } +} + +impl SubDiagnostic { + pub fn message(&self) -> String { + self.message.iter().map(|i| i.0.as_str()).collect::<String>() + } + + pub fn styled_message(&self) -> &Vec<(String, Style)> { + &self.message + } +} diff --git a/compiler/rustc_errors/src/diagnostic_builder.rs b/compiler/rustc_errors/src/diagnostic_builder.rs new file mode 100644 index 00000000000..d1ff6f721c4 --- /dev/null +++ b/compiler/rustc_errors/src/diagnostic_builder.rs @@ -0,0 +1,452 @@ +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()) }}; +} diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs new file mode 100644 index 00000000000..5a654e83aed --- /dev/null +++ b/compiler/rustc_errors/src/emitter.rs @@ -0,0 +1,2177 @@ +//! The current rustc diagnostics emitter. +//! +//! An `Emitter` takes care of generating the output from a `DiagnosticBuilder` struct. +//! +//! There are various `Emitter` implementations that generate different output formats such as +//! JSON and human readable output. +//! +//! The output types are defined in `rustc_session::config::ErrorOutputType`. + +use Destination::*; + +use rustc_span::source_map::SourceMap; +use rustc_span::{MultiSpan, SourceFile, Span}; + +use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString}; +use crate::styled_buffer::StyledBuffer; +use crate::{ + pluralize, CodeSuggestion, Diagnostic, DiagnosticId, Level, SubDiagnostic, SuggestionStyle, +}; + +use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::sync::Lrc; +use rustc_span::hygiene::{ExpnKind, MacroKind}; +use std::borrow::Cow; +use std::cmp::{max, min, Reverse}; +use std::io; +use std::io::prelude::*; +use std::iter; +use std::path::Path; +use termcolor::{Ansi, BufferWriter, ColorChoice, ColorSpec, StandardStream}; +use termcolor::{Buffer, Color, WriteColor}; +use tracing::*; + +/// Default column width, used in tests and when terminal dimensions cannot be determined. +const DEFAULT_COLUMN_WIDTH: usize = 140; + +/// Describes the way the content of the `rendered` field of the json output is generated +#[derive(Clone, Copy, Debug, PartialEq, Eq)] +pub enum HumanReadableErrorType { + Default(ColorConfig), + AnnotateSnippet(ColorConfig), + Short(ColorConfig), +} + +impl HumanReadableErrorType { + /// Returns a (`short`, `color`) tuple + pub fn unzip(self) -> (bool, ColorConfig) { + match self { + HumanReadableErrorType::Default(cc) => (false, cc), + HumanReadableErrorType::Short(cc) => (true, cc), + HumanReadableErrorType::AnnotateSnippet(cc) => (false, cc), + } + } + pub fn new_emitter( + self, + dst: Box<dyn Write + Send>, + source_map: Option<Lrc<SourceMap>>, + teach: bool, + terminal_width: Option<usize>, + macro_backtrace: bool, + ) -> EmitterWriter { + let (short, color_config) = self.unzip(); + let color = color_config.suggests_using_colors(); + EmitterWriter::new(dst, source_map, short, teach, color, terminal_width, macro_backtrace) + } +} + +#[derive(Clone, Copy, Debug)] +struct Margin { + /// The available whitespace in the left that can be consumed when centering. + pub whitespace_left: usize, + /// The column of the beginning of left-most span. + pub span_left: usize, + /// The column of the end of right-most span. + pub span_right: usize, + /// The beginning of the line to be displayed. + pub computed_left: usize, + /// The end of the line to be displayed. + pub computed_right: usize, + /// The current width of the terminal. Uses value of `DEFAULT_COLUMN_WIDTH` constant by default + /// and in tests. + pub column_width: usize, + /// The end column of a span label, including the span. Doesn't account for labels not in the + /// same line as the span. + pub label_right: usize, +} + +impl Margin { + fn new( + whitespace_left: usize, + span_left: usize, + span_right: usize, + label_right: usize, + column_width: usize, + max_line_len: usize, + ) -> Self { + // The 6 is padding to give a bit of room for `...` when displaying: + // ``` + // error: message + // --> file.rs:16:58 + // | + // 16 | ... fn foo(self) -> Self::Bar { + // | ^^^^^^^^^ + // ``` + + let mut m = Margin { + whitespace_left: whitespace_left.saturating_sub(6), + span_left: span_left.saturating_sub(6), + span_right: span_right + 6, + computed_left: 0, + computed_right: 0, + column_width, + label_right: label_right + 6, + }; + m.compute(max_line_len); + m + } + + fn was_cut_left(&self) -> bool { + self.computed_left > 0 + } + + fn was_cut_right(&self, line_len: usize) -> bool { + let right = + if self.computed_right == self.span_right || self.computed_right == self.label_right { + // Account for the "..." padding given above. Otherwise we end up with code lines that + // do fit but end in "..." as if they were trimmed. + self.computed_right - 6 + } else { + self.computed_right + }; + right < line_len && self.computed_left + self.column_width < line_len + } + + fn compute(&mut self, max_line_len: usize) { + // When there's a lot of whitespace (>20), we want to trim it as it is useless. + self.computed_left = if self.whitespace_left > 20 { + self.whitespace_left - 16 // We want some padding. + } else { + 0 + }; + // We want to show as much as possible, max_line_len is the right-most boundary for the + // relevant code. + self.computed_right = max(max_line_len, self.computed_left); + + if self.computed_right - self.computed_left > self.column_width { + // Trimming only whitespace isn't enough, let's get craftier. + if self.label_right - self.whitespace_left <= self.column_width { + // Attempt to fit the code window only trimming whitespace. + self.computed_left = self.whitespace_left; + self.computed_right = self.computed_left + self.column_width; + } else if self.label_right - self.span_left <= self.column_width { + // Attempt to fit the code window considering only the spans and labels. + let padding_left = (self.column_width - (self.label_right - self.span_left)) / 2; + self.computed_left = self.span_left.saturating_sub(padding_left); + self.computed_right = self.computed_left + self.column_width; + } else if self.span_right - self.span_left <= self.column_width { + // Attempt to fit the code window considering the spans and labels plus padding. + let padding_left = (self.column_width - (self.span_right - self.span_left)) / 5 * 2; + self.computed_left = self.span_left.saturating_sub(padding_left); + self.computed_right = self.computed_left + self.column_width; + } else { + // Mostly give up but still don't show the full line. + self.computed_left = self.span_left; + self.computed_right = self.span_right; + } + } + } + + fn left(&self, line_len: usize) -> usize { + min(self.computed_left, line_len) + } + + fn right(&self, line_len: usize) -> usize { + if line_len.saturating_sub(self.computed_left) <= self.column_width { + line_len + } else { + min(line_len, self.computed_right) + } + } +} + +const ANONYMIZED_LINE_NUM: &str = "LL"; + +/// Emitter trait for emitting errors. +pub trait Emitter { + /// Emit a structured diagnostic. + fn emit_diagnostic(&mut self, diag: &Diagnostic); + + /// Emit a notification that an artifact has been output. + /// This is currently only supported for the JSON format, + /// other formats can, and will, simply ignore it. + fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {} + + /// Checks if should show explanations about "rustc --explain" + fn should_show_explain(&self) -> bool { + true + } + + fn source_map(&self) -> Option<&Lrc<SourceMap>>; + + /// Formats the substitutions of the primary_span + /// + /// The are a lot of conditions to this method, but in short: + /// + /// * If the current `Diagnostic` has only one visible `CodeSuggestion`, + /// we format the `help` suggestion depending on the content of the + /// substitutions. In that case, we return the modified span only. + /// + /// * If the current `Diagnostic` has multiple suggestions, + /// we return the original `primary_span` and the original suggestions. + fn primary_span_formatted<'a>( + &mut self, + diag: &'a Diagnostic, + ) -> (MultiSpan, &'a [CodeSuggestion]) { + let mut primary_span = diag.span.clone(); + if let Some((sugg, rest)) = diag.suggestions.split_first() { + if rest.is_empty() && + // ^ if there is only one suggestion + // don't display multi-suggestions as labels + sugg.substitutions.len() == 1 && + // don't display multipart suggestions as labels + sugg.substitutions[0].parts.len() == 1 && + // don't display long messages as labels + sugg.msg.split_whitespace().count() < 10 && + // don't display multiline suggestions as labels + !sugg.substitutions[0].parts[0].snippet.contains('\n') && + ![ + // when this style is set we want the suggestion to be a message, not inline + SuggestionStyle::HideCodeAlways, + // trivial suggestion for tooling's sake, never shown + SuggestionStyle::CompletelyHidden, + // subtle suggestion, never shown inline + SuggestionStyle::ShowAlways, + ].contains(&sugg.style) + { + let substitution = &sugg.substitutions[0].parts[0].snippet.trim(); + let msg = if substitution.is_empty() || sugg.style.hide_inline() { + // This substitution is only removal OR we explicitly don't want to show the + // code inline (`hide_inline`). Therefore, we don't show the substitution. + format!("help: {}", sugg.msg) + } else { + // Show the default suggestion text with the substitution + format!( + "help: {}{}: `{}`", + sugg.msg, + if self + .source_map() + .map(|sm| is_case_difference( + &**sm, + substitution, + sugg.substitutions[0].parts[0].span, + )) + .unwrap_or(false) + { + " (notice the capitalization)" + } else { + "" + }, + substitution, + ) + }; + primary_span.push_span_label(sugg.substitutions[0].parts[0].span, msg); + + // We return only the modified primary_span + (primary_span, &[]) + } else { + // if there are multiple suggestions, print them all in full + // to be consistent. We could try to figure out if we can + // make one (or the first one) inline, but that would give + // undue importance to a semi-random suggestion + (primary_span, &diag.suggestions) + } + } else { + (primary_span, &diag.suggestions) + } + } + + fn fix_multispans_in_extern_macros_and_render_macro_backtrace( + &self, + source_map: &Option<Lrc<SourceMap>>, + span: &mut MultiSpan, + children: &mut Vec<SubDiagnostic>, + level: &Level, + backtrace: bool, + ) { + // Check for spans in macros, before `fix_multispans_in_extern_macros` + // has a chance to replace them. + let has_macro_spans = iter::once(&*span) + .chain(children.iter().map(|child| &child.span)) + .flat_map(|span| span.primary_spans()) + .flat_map(|sp| sp.macro_backtrace()) + .find_map(|expn_data| { + match expn_data.kind { + ExpnKind::Root => None, + + // Skip past non-macro entries, just in case there + // are some which do actually involve macros. + ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None, + + ExpnKind::Macro(macro_kind, _) => Some(macro_kind), + } + }); + + if !backtrace { + self.fix_multispans_in_extern_macros(source_map, span, children); + } + + self.render_multispans_macro_backtrace(span, children, backtrace); + + if !backtrace { + if let Some(macro_kind) = has_macro_spans { + let msg = format!( + "this {} originates in {} {} \ + (in Nightly builds, run with -Z macro-backtrace for more info)", + level, + macro_kind.article(), + macro_kind.descr(), + ); + + children.push(SubDiagnostic { + level: Level::Note, + message: vec![(msg, Style::NoStyle)], + span: MultiSpan::new(), + render_span: None, + }); + } + } + } + + fn render_multispans_macro_backtrace( + &self, + span: &mut MultiSpan, + children: &mut Vec<SubDiagnostic>, + backtrace: bool, + ) { + for span in iter::once(span).chain(children.iter_mut().map(|child| &mut child.span)) { + self.render_multispan_macro_backtrace(span, backtrace); + } + } + + fn render_multispan_macro_backtrace(&self, span: &mut MultiSpan, always_backtrace: bool) { + let mut new_labels: Vec<(Span, String)> = vec![]; + + for &sp in span.primary_spans() { + if sp.is_dummy() { + continue; + } + + // FIXME(eddyb) use `retain` on `macro_backtrace` to remove all the + // entries we don't want to print, to make sure the indices being + // printed are contiguous (or omitted if there's only one entry). + let macro_backtrace: Vec<_> = sp.macro_backtrace().collect(); + for (i, trace) in macro_backtrace.iter().rev().enumerate() { + if trace.def_site.is_dummy() { + continue; + } + + if always_backtrace { + new_labels.push(( + trace.def_site, + format!( + "in this expansion of `{}`{}", + trace.kind.descr(), + if macro_backtrace.len() > 1 { + // if macro_backtrace.len() == 1 it'll be + // pointed at by "in this macro invocation" + format!(" (#{})", i + 1) + } else { + String::new() + }, + ), + )); + } + + // Don't add a label on the call site if the diagnostic itself + // already points to (a part of) that call site, as the label + // is meant for showing the relevant invocation when the actual + // diagnostic is pointing to some part of macro definition. + // + // This also handles the case where an external span got replaced + // with the call site span by `fix_multispans_in_extern_macros`. + // + // NB: `-Zmacro-backtrace` overrides this, for uniformity, as the + // "in this expansion of" label above is always added in that mode, + // and it needs an "in this macro invocation" label to match that. + let redundant_span = trace.call_site.contains(sp); + + if !redundant_span && matches!(trace.kind, ExpnKind::Macro(MacroKind::Bang, _)) + || always_backtrace + { + new_labels.push(( + trace.call_site, + format!( + "in this macro invocation{}", + if macro_backtrace.len() > 1 && always_backtrace { + // only specify order when the macro + // backtrace is multiple levels deep + format!(" (#{})", i + 1) + } else { + String::new() + }, + ), + )); + } + if !always_backtrace { + break; + } + } + } + + for (label_span, label_text) in new_labels { + span.push_span_label(label_span, label_text); + } + } + + // This does a small "fix" for multispans by looking to see if it can find any that + // point directly at external macros. Since these are often difficult to read, + // this will change the span to point at the use site. + fn fix_multispans_in_extern_macros( + &self, + source_map: &Option<Lrc<SourceMap>>, + span: &mut MultiSpan, + children: &mut Vec<SubDiagnostic>, + ) { + debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children); + for span in iter::once(&mut *span).chain(children.iter_mut().map(|child| &mut child.span)) { + self.fix_multispan_in_extern_macros(source_map, span); + } + debug!("fix_multispans_in_extern_macros: after: span={:?} children={:?}", span, children); + } + + // This "fixes" MultiSpans that contain `Span`s pointing to locations inside of external macros. + // Since these locations are often difficult to read, + // we move these spans from the external macros to their corresponding use site. + fn fix_multispan_in_extern_macros( + &self, + source_map: &Option<Lrc<SourceMap>>, + span: &mut MultiSpan, + ) { + let sm = match source_map { + Some(ref sm) => sm, + None => return, + }; + + // First, find all the spans in external macros and point instead at their use site. + let replacements: Vec<(Span, Span)> = span + .primary_spans() + .iter() + .copied() + .chain(span.span_labels().iter().map(|sp_label| sp_label.span)) + .filter_map(|sp| { + if !sp.is_dummy() && sm.is_imported(sp) { + let maybe_callsite = sp.source_callsite(); + if sp != maybe_callsite { + return Some((sp, maybe_callsite)); + } + } + None + }) + .collect(); + + // After we have them, make sure we replace these 'bad' def sites with their use sites. + for (from, to) in replacements { + span.replace(from, to); + } + } +} + +impl Emitter for EmitterWriter { + fn source_map(&self) -> Option<&Lrc<SourceMap>> { + self.sm.as_ref() + } + + fn emit_diagnostic(&mut self, diag: &Diagnostic) { + let mut children = diag.children.clone(); + let (mut primary_span, suggestions) = self.primary_span_formatted(&diag); + debug!("emit_diagnostic: suggestions={:?}", suggestions); + + self.fix_multispans_in_extern_macros_and_render_macro_backtrace( + &self.sm, + &mut primary_span, + &mut children, + &diag.level, + self.macro_backtrace, + ); + + self.emit_messages_default( + &diag.level, + &diag.styled_message(), + &diag.code, + &primary_span, + &children, + &suggestions, + ); + } + + fn should_show_explain(&self) -> bool { + !self.short_message + } +} + +/// An emitter that does nothing when emitting a diagnostic. +pub struct SilentEmitter; + +impl Emitter for SilentEmitter { + fn source_map(&self) -> Option<&Lrc<SourceMap>> { + None + } + fn emit_diagnostic(&mut self, _: &Diagnostic) {} +} + +/// Maximum number of lines we will print for each error; arbitrary. +pub const MAX_HIGHLIGHT_LINES: usize = 6; +/// Maximum number of lines we will print for a multiline suggestion; arbitrary. +/// +/// This should be replaced with a more involved mechanism to output multiline suggestions that +/// more closely mimmics the regular diagnostic output, where irrelevant code lines are elided. +pub const MAX_SUGGESTION_HIGHLIGHT_LINES: usize = 6; +/// Maximum number of suggestions to be shown +/// +/// Arbitrary, but taken from trait import suggestion limit +pub const MAX_SUGGESTIONS: usize = 4; + +#[derive(Clone, Copy, Debug, PartialEq, Eq)] +pub enum ColorConfig { + Auto, + Always, + Never, +} + +impl ColorConfig { + fn to_color_choice(self) -> ColorChoice { + match self { + ColorConfig::Always => { + if atty::is(atty::Stream::Stderr) { + ColorChoice::Always + } else { + ColorChoice::AlwaysAnsi + } + } + ColorConfig::Never => ColorChoice::Never, + ColorConfig::Auto if atty::is(atty::Stream::Stderr) => ColorChoice::Auto, + ColorConfig::Auto => ColorChoice::Never, + } + } + fn suggests_using_colors(self) -> bool { + match self { + ColorConfig::Always | ColorConfig::Auto => true, + ColorConfig::Never => false, + } + } +} + +/// Handles the writing of `HumanReadableErrorType::Default` and `HumanReadableErrorType::Short` +pub struct EmitterWriter { + dst: Destination, + sm: Option<Lrc<SourceMap>>, + short_message: bool, + teach: bool, + ui_testing: bool, + terminal_width: Option<usize>, + + macro_backtrace: bool, +} + +#[derive(Debug)] +pub struct FileWithAnnotatedLines { + pub file: Lrc<SourceFile>, + pub lines: Vec<Line>, + multiline_depth: usize, +} + +impl EmitterWriter { + pub fn stderr( + color_config: ColorConfig, + source_map: Option<Lrc<SourceMap>>, + short_message: bool, + teach: bool, + terminal_width: Option<usize>, + macro_backtrace: bool, + ) -> EmitterWriter { + let dst = Destination::from_stderr(color_config); + EmitterWriter { + dst, + sm: source_map, + short_message, + teach, + ui_testing: false, + terminal_width, + macro_backtrace, + } + } + + pub fn new( + dst: Box<dyn Write + Send>, + source_map: Option<Lrc<SourceMap>>, + short_message: bool, + teach: bool, + colored: bool, + terminal_width: Option<usize>, + macro_backtrace: bool, + ) -> EmitterWriter { + EmitterWriter { + dst: Raw(dst, colored), + sm: source_map, + short_message, + teach, + ui_testing: false, + terminal_width, + macro_backtrace, + } + } + + pub fn ui_testing(mut self, ui_testing: bool) -> Self { + self.ui_testing = ui_testing; + self + } + + fn maybe_anonymized(&self, line_num: usize) -> String { + if self.ui_testing { ANONYMIZED_LINE_NUM.to_string() } else { line_num.to_string() } + } + + fn draw_line( + &self, + buffer: &mut StyledBuffer, + source_string: &str, + line_index: usize, + line_offset: usize, + width_offset: usize, + code_offset: usize, + margin: Margin, + ) { + let line_len = source_string.len(); + // Create the source line we will highlight. + let left = margin.left(line_len); + let right = margin.right(line_len); + // On long lines, we strip the source line, accounting for unicode. + let mut taken = 0; + let code: String = source_string + .chars() + .skip(left) + .take_while(|ch| { + // Make sure that the trimming on the right will fall within the terminal width. + // FIXME: `unicode_width` sometimes disagrees with terminals on how wide a `char` is. + // For now, just accept that sometimes the code line will be longer than desired. + let next = unicode_width::UnicodeWidthChar::width(*ch).unwrap_or(1); + if taken + next > right - left { + return false; + } + taken += next; + true + }) + .collect(); + buffer.puts(line_offset, code_offset, &code, Style::Quotation); + if margin.was_cut_left() { + // We have stripped some code/whitespace from the beginning, make it clear. + buffer.puts(line_offset, code_offset, "...", Style::LineNumber); + } + if margin.was_cut_right(line_len) { + // We have stripped some code after the right-most span end, make it clear we did so. + buffer.puts(line_offset, code_offset + taken - 3, "...", Style::LineNumber); + } + buffer.puts(line_offset, 0, &self.maybe_anonymized(line_index), Style::LineNumber); + + draw_col_separator(buffer, line_offset, width_offset - 2); + } + + fn render_source_line( + &self, + buffer: &mut StyledBuffer, + file: Lrc<SourceFile>, + line: &Line, + width_offset: usize, + code_offset: usize, + margin: Margin, + ) -> Vec<(usize, Style)> { + // Draw: + // + // LL | ... code ... + // | ^^-^ span label + // | | + // | secondary span label + // + // ^^ ^ ^^^ ^^^^ ^^^ we don't care about code too far to the right of a span, we trim it + // | | | | + // | | | actual code found in your source code and the spans we use to mark it + // | | when there's too much wasted space to the left, trim it + // | vertical divider between the column number and the code + // column number + + if line.line_index == 0 { + return Vec::new(); + } + + let source_string = match file.get_line(line.line_index - 1) { + Some(s) => s, + None => return Vec::new(), + }; + + let line_offset = buffer.num_lines(); + + let left = margin.left(source_string.len()); // Left trim + // Account for unicode characters of width !=0 that were removed. + let left = source_string + .chars() + .take(left) + .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1)) + .sum(); + + self.draw_line( + buffer, + &source_string, + line.line_index, + line_offset, + width_offset, + code_offset, + margin, + ); + + // Special case when there's only one annotation involved, it is the start of a multiline + // span and there's no text at the beginning of the code line. Instead of doing the whole + // graph: + // + // 2 | fn foo() { + // | _^ + // 3 | | + // 4 | | } + // | |_^ test + // + // we simplify the output to: + // + // 2 | / fn foo() { + // 3 | | + // 4 | | } + // | |_^ test + if let [ann] = &line.annotations[..] { + if let AnnotationType::MultilineStart(depth) = ann.annotation_type { + if source_string.chars().take(ann.start_col).all(|c| c.is_whitespace()) { + let style = if ann.is_primary { + Style::UnderlinePrimary + } else { + Style::UnderlineSecondary + }; + buffer.putc(line_offset, width_offset + depth - 1, '/', style); + return vec![(depth, style)]; + } + } + } + + // We want to display like this: + // + // vec.push(vec.pop().unwrap()); + // --- ^^^ - previous borrow ends here + // | | + // | error occurs here + // previous borrow of `vec` occurs here + // + // But there are some weird edge cases to be aware of: + // + // vec.push(vec.pop().unwrap()); + // -------- - previous borrow ends here + // || + // |this makes no sense + // previous borrow of `vec` occurs here + // + // For this reason, we group the lines into "highlight lines" + // and "annotations lines", where the highlight lines have the `^`. + + // Sort the annotations by (start, end col) + // The labels are reversed, sort and then reversed again. + // Consider a list of annotations (A1, A2, C1, C2, B1, B2) where + // the letter signifies the span. Here we are only sorting by the + // span and hence, the order of the elements with the same span will + // not change. On reversing the ordering (|a, b| but b.cmp(a)), you get + // (C1, C2, B1, B2, A1, A2). All the elements with the same span are + // still ordered first to last, but all the elements with different + // spans are ordered by their spans in last to first order. Last to + // first order is important, because the jiggly lines and | are on + // the left, so the rightmost span needs to be rendered first, + // otherwise the lines would end up needing to go over a message. + + let mut annotations = line.annotations.clone(); + annotations.sort_by_key(|a| Reverse(a.start_col)); + + // First, figure out where each label will be positioned. + // + // In the case where you have the following annotations: + // + // vec.push(vec.pop().unwrap()); + // -------- - previous borrow ends here [C] + // || + // |this makes no sense [B] + // previous borrow of `vec` occurs here [A] + // + // `annotations_position` will hold [(2, A), (1, B), (0, C)]. + // + // We try, when possible, to stick the rightmost annotation at the end + // of the highlight line: + // + // vec.push(vec.pop().unwrap()); + // --- --- - previous borrow ends here + // + // But sometimes that's not possible because one of the other + // annotations overlaps it. For example, from the test + // `span_overlap_label`, we have the following annotations + // (written on distinct lines for clarity): + // + // fn foo(x: u32) { + // -------------- + // - + // + // In this case, we can't stick the rightmost-most label on + // the highlight line, or we would get: + // + // fn foo(x: u32) { + // -------- x_span + // | + // fn_span + // + // which is totally weird. Instead we want: + // + // fn foo(x: u32) { + // -------------- + // | | + // | x_span + // fn_span + // + // which is...less weird, at least. In fact, in general, if + // the rightmost span overlaps with any other span, we should + // use the "hang below" version, so we can at least make it + // clear where the span *starts*. There's an exception for this + // logic, when the labels do not have a message: + // + // fn foo(x: u32) { + // -------------- + // | + // x_span + // + // instead of: + // + // fn foo(x: u32) { + // -------------- + // | | + // | x_span + // <EMPTY LINE> + // + let mut annotations_position = vec![]; + let mut line_len = 0; + let mut p = 0; + for (i, annotation) in annotations.iter().enumerate() { + for (j, next) in annotations.iter().enumerate() { + if overlaps(next, annotation, 0) // This label overlaps with another one and both + && annotation.has_label() // take space (they have text and are not + && j > i // multiline lines). + && p == 0 + // We're currently on the first line, move the label one line down + { + // If we're overlapping with an un-labelled annotation with the same span + // we can just merge them in the output + if next.start_col == annotation.start_col + && next.end_col == annotation.end_col + && !next.has_label() + { + continue; + } + + // This annotation needs a new line in the output. + p += 1; + break; + } + } + annotations_position.push((p, annotation)); + for (j, next) in annotations.iter().enumerate() { + if j > i { + let l = next.label.as_ref().map_or(0, |label| label.len() + 2); + if (overlaps(next, annotation, l) // Do not allow two labels to be in the same + // line if they overlap including padding, to + // avoid situations like: + // + // fn foo(x: u32) { + // -------^------ + // | | + // fn_spanx_span + // + && annotation.has_label() // Both labels must have some text, otherwise + && next.has_label()) // they are not overlapping. + // Do not add a new line if this annotation + // or the next are vertical line placeholders. + || (annotation.takes_space() // If either this or the next annotation is + && next.has_label()) // multiline start/end, move it to a new line + || (annotation.has_label() // so as not to overlap the orizontal lines. + && next.takes_space()) + || (annotation.takes_space() && next.takes_space()) + || (overlaps(next, annotation, l) + && next.end_col <= annotation.end_col + && next.has_label() + && p == 0) + // Avoid #42595. + { + // This annotation needs a new line in the output. + p += 1; + break; + } + } + } + line_len = max(line_len, p); + } + + if line_len != 0 { + line_len += 1; + } + + // If there are no annotations or the only annotations on this line are + // MultilineLine, then there's only code being shown, stop processing. + if line.annotations.iter().all(|a| a.is_line()) { + return vec![]; + } + + // Write the column separator. + // + // After this we will have: + // + // 2 | fn foo() { + // | + // | + // | + // 3 | + // 4 | } + // | + for pos in 0..=line_len { + draw_col_separator(buffer, line_offset + pos + 1, width_offset - 2); + buffer.putc(line_offset + pos + 1, width_offset - 2, '|', Style::LineNumber); + } + + // Write the horizontal lines for multiline annotations + // (only the first and last lines need this). + // + // After this we will have: + // + // 2 | fn foo() { + // | __________ + // | + // | + // 3 | + // 4 | } + // | _ + for &(pos, annotation) in &annotations_position { + let style = if annotation.is_primary { + Style::UnderlinePrimary + } else { + Style::UnderlineSecondary + }; + let pos = pos + 1; + match annotation.annotation_type { + AnnotationType::MultilineStart(depth) | AnnotationType::MultilineEnd(depth) => { + draw_range( + buffer, + '_', + line_offset + pos, + width_offset + depth, + code_offset + annotation.start_col - left, + style, + ); + } + _ if self.teach => { + buffer.set_style_range( + line_offset, + code_offset + annotation.start_col - left, + code_offset + annotation.end_col - left, + style, + annotation.is_primary, + ); + } + _ => {} + } + } + + // Write the vertical lines for labels that are on a different line as the underline. + // + // After this we will have: + // + // 2 | fn foo() { + // | __________ + // | | | + // | | + // 3 | | + // 4 | | } + // | |_ + for &(pos, annotation) in &annotations_position { + let style = if annotation.is_primary { + Style::UnderlinePrimary + } else { + Style::UnderlineSecondary + }; + let pos = pos + 1; + + if pos > 1 && (annotation.has_label() || annotation.takes_space()) { + for p in line_offset + 1..=line_offset + pos { + buffer.putc( + p, + (code_offset + annotation.start_col).saturating_sub(left), + '|', + style, + ); + } + } + match annotation.annotation_type { + AnnotationType::MultilineStart(depth) => { + for p in line_offset + pos + 1..line_offset + line_len + 2 { + buffer.putc(p, width_offset + depth - 1, '|', style); + } + } + AnnotationType::MultilineEnd(depth) => { + for p in line_offset..=line_offset + pos { + buffer.putc(p, width_offset + depth - 1, '|', style); + } + } + _ => (), + } + } + + // Write the labels on the annotations that actually have a label. + // + // After this we will have: + // + // 2 | fn foo() { + // | __________ + // | | + // | something about `foo` + // 3 | + // 4 | } + // | _ test + for &(pos, annotation) in &annotations_position { + let style = + if annotation.is_primary { Style::LabelPrimary } else { Style::LabelSecondary }; + let (pos, col) = if pos == 0 { + (pos + 1, (annotation.end_col + 1).saturating_sub(left)) + } else { + (pos + 2, annotation.start_col.saturating_sub(left)) + }; + if let Some(ref label) = annotation.label { + buffer.puts(line_offset + pos, code_offset + col, &label, style); + } + } + + // Sort from biggest span to smallest span so that smaller spans are + // represented in the output: + // + // x | fn foo() + // | ^^^---^^ + // | | | + // | | something about `foo` + // | something about `fn foo()` + annotations_position.sort_by_key(|(_, ann)| { + // Decreasing order. When annotations share the same length, prefer `Primary`. + (Reverse(ann.len()), ann.is_primary) + }); + + // Write the underlines. + // + // After this we will have: + // + // 2 | fn foo() { + // | ____-_____^ + // | | + // | something about `foo` + // 3 | + // 4 | } + // | _^ test + for &(_, annotation) in &annotations_position { + let (underline, style) = if annotation.is_primary { + ('^', Style::UnderlinePrimary) + } else { + ('-', Style::UnderlineSecondary) + }; + for p in annotation.start_col..annotation.end_col { + buffer.putc( + line_offset + 1, + (code_offset + p).saturating_sub(left), + underline, + style, + ); + } + } + annotations_position + .iter() + .filter_map(|&(_, annotation)| match annotation.annotation_type { + AnnotationType::MultilineStart(p) | AnnotationType::MultilineEnd(p) => { + let style = if annotation.is_primary { + Style::LabelPrimary + } else { + Style::LabelSecondary + }; + Some((p, style)) + } + _ => None, + }) + .collect::<Vec<_>>() + } + + fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize { + let sm = match self.sm { + Some(ref sm) => sm, + None => return 0, + }; + + let mut max = 0; + for primary_span in msp.primary_spans() { + if !primary_span.is_dummy() { + let hi = sm.lookup_char_pos(primary_span.hi()); + max = (hi.line).max(max); + } + } + if !self.short_message { + for span_label in msp.span_labels() { + if !span_label.span.is_dummy() { + let hi = sm.lookup_char_pos(span_label.span.hi()); + max = (hi.line).max(max); + } + } + } + + max + } + + fn get_max_line_num(&mut self, span: &MultiSpan, children: &[SubDiagnostic]) -> usize { + let primary = self.get_multispan_max_line_num(span); + children + .iter() + .map(|sub| self.get_multispan_max_line_num(&sub.span)) + .max() + .unwrap_or(0) + .max(primary) + } + + /// Adds a left margin to every line but the first, given a padding length and the label being + /// displayed, keeping the provided highlighting. + fn msg_to_buffer( + &self, + buffer: &mut StyledBuffer, + msg: &[(String, Style)], + padding: usize, + label: &str, + override_style: Option<Style>, + ) { + // The extra 5 ` ` is padding that's always needed to align to the `note: `: + // + // error: message + // --> file.rs:13:20 + // | + // 13 | <CODE> + // | ^^^^ + // | + // = note: multiline + // message + // ++^^^----xx + // | | | | + // | | | magic `2` + // | | length of label + // | magic `3` + // `max_line_num_len` + let padding = " ".repeat(padding + label.len() + 5); + + /// Returns `override` if it is present and `style` is `NoStyle` or `style` otherwise + fn style_or_override(style: Style, override_: Option<Style>) -> Style { + match (style, override_) { + (Style::NoStyle, Some(override_)) => override_, + _ => style, + } + } + + let mut line_number = 0; + + // Provided the following diagnostic message: + // + // let msg = vec![ + // (" + // ("highlighted multiline\nstring to\nsee how it ", Style::NoStyle), + // ("looks", Style::Highlight), + // ("with\nvery ", Style::NoStyle), + // ("weird", Style::Highlight), + // (" formats\n", Style::NoStyle), + // ("see?", Style::Highlight), + // ]; + // + // the expected output on a note is (* surround the highlighted text) + // + // = note: highlighted multiline + // string to + // see how it *looks* with + // very *weird* formats + // see? + for &(ref text, ref style) in msg.iter() { + let lines = text.split('\n').collect::<Vec<_>>(); + if lines.len() > 1 { + for (i, line) in lines.iter().enumerate() { + if i != 0 { + line_number += 1; + buffer.append(line_number, &padding, Style::NoStyle); + } + buffer.append(line_number, line, style_or_override(*style, override_style)); + } + } else { + buffer.append(line_number, text, style_or_override(*style, override_style)); + } + } + } + + fn emit_message_default( + &mut self, + msp: &MultiSpan, + msg: &[(String, Style)], + code: &Option<DiagnosticId>, + level: &Level, + max_line_num_len: usize, + is_secondary: bool, + ) -> io::Result<()> { + let mut buffer = StyledBuffer::new(); + let header_style = if is_secondary { Style::HeaderMsg } else { Style::MainHeaderMsg }; + + if !msp.has_primary_spans() && !msp.has_span_labels() && is_secondary && !self.short_message + { + // This is a secondary message with no span info + for _ in 0..max_line_num_len { + buffer.prepend(0, " ", Style::NoStyle); + } + draw_note_separator(&mut buffer, 0, max_line_num_len + 1); + if *level != Level::FailureNote { + let level_str = level.to_string(); + if !level_str.is_empty() { + buffer.append(0, &level_str, Style::MainHeaderMsg); + buffer.append(0, ": ", Style::NoStyle); + } + } + self.msg_to_buffer(&mut buffer, msg, max_line_num_len, "note", None); + } else { + let level_str = level.to_string(); + // The failure note level itself does not provide any useful diagnostic information + if *level != Level::FailureNote && !level_str.is_empty() { + buffer.append(0, &level_str, Style::Level(*level)); + } + // only render error codes, not lint codes + if let Some(DiagnosticId::Error(ref code)) = *code { + buffer.append(0, "[", Style::Level(*level)); + buffer.append(0, &code, Style::Level(*level)); + buffer.append(0, "]", Style::Level(*level)); + } + if *level != Level::FailureNote && !level_str.is_empty() { + buffer.append(0, ": ", header_style); + } + for &(ref text, _) in msg.iter() { + buffer.append(0, text, header_style); + } + } + + let mut annotated_files = FileWithAnnotatedLines::collect_annotations(msp, &self.sm); + + // Make sure our primary file comes first + let (primary_lo, sm) = if let (Some(sm), Some(ref primary_span)) = + (self.sm.as_ref(), msp.primary_span().as_ref()) + { + if !primary_span.is_dummy() { + (sm.lookup_char_pos(primary_span.lo()), sm) + } else { + emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?; + return Ok(()); + } + } else { + // If we don't have span information, emit and exit + emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?; + return Ok(()); + }; + if let Ok(pos) = + annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name)) + { + annotated_files.swap(0, pos); + } + + // Print out the annotate source lines that correspond with the error + for annotated_file in annotated_files { + // we can't annotate anything if the source is unavailable. + if !sm.ensure_source_file_source_present(annotated_file.file.clone()) { + continue; + } + + // print out the span location and spacer before we print the annotated source + // to do this, we need to know if this span will be primary + let is_primary = primary_lo.file.name == annotated_file.file.name; + if is_primary { + let loc = primary_lo.clone(); + if !self.short_message { + // remember where we are in the output buffer for easy reference + let buffer_msg_line_offset = buffer.num_lines(); + + buffer.prepend(buffer_msg_line_offset, "--> ", Style::LineNumber); + buffer.append( + buffer_msg_line_offset, + &format!( + "{}:{}:{}", + loc.file.name, + sm.doctest_offset_line(&loc.file.name, loc.line), + loc.col.0 + 1, + ), + Style::LineAndColumn, + ); + for _ in 0..max_line_num_len { + buffer.prepend(buffer_msg_line_offset, " ", Style::NoStyle); + } + } else { + buffer.prepend( + 0, + &format!( + "{}:{}:{}: ", + loc.file.name, + sm.doctest_offset_line(&loc.file.name, loc.line), + loc.col.0 + 1, + ), + Style::LineAndColumn, + ); + } + } else if !self.short_message { + // remember where we are in the output buffer for easy reference + let buffer_msg_line_offset = buffer.num_lines(); + + // Add spacing line + draw_col_separator(&mut buffer, buffer_msg_line_offset, max_line_num_len + 1); + + // Then, the secondary file indicator + buffer.prepend(buffer_msg_line_offset + 1, "::: ", Style::LineNumber); + let loc = if let Some(first_line) = annotated_file.lines.first() { + let col = if let Some(first_annotation) = first_line.annotations.first() { + format!(":{}", first_annotation.start_col + 1) + } else { + String::new() + }; + format!( + "{}:{}{}", + annotated_file.file.name, + sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index), + col + ) + } else { + annotated_file.file.name.to_string() + }; + buffer.append(buffer_msg_line_offset + 1, &loc, Style::LineAndColumn); + for _ in 0..max_line_num_len { + buffer.prepend(buffer_msg_line_offset + 1, " ", Style::NoStyle); + } + } + + if !self.short_message { + // Put in the spacer between the location and annotated source + let buffer_msg_line_offset = buffer.num_lines(); + draw_col_separator_no_space( + &mut buffer, + buffer_msg_line_offset, + max_line_num_len + 1, + ); + + // Contains the vertical lines' positions for active multiline annotations + let mut multilines = FxHashMap::default(); + + // Get the left-side margin to remove it + let mut whitespace_margin = usize::MAX; + for line_idx in 0..annotated_file.lines.len() { + let file = annotated_file.file.clone(); + let line = &annotated_file.lines[line_idx]; + if let Some(source_string) = file.get_line(line.line_index - 1) { + let leading_whitespace = + source_string.chars().take_while(|c| c.is_whitespace()).count(); + if source_string.chars().any(|c| !c.is_whitespace()) { + whitespace_margin = min(whitespace_margin, leading_whitespace); + } + } + } + if whitespace_margin == usize::MAX { + whitespace_margin = 0; + } + + // Left-most column any visible span points at. + let mut span_left_margin = usize::MAX; + for line in &annotated_file.lines { + for ann in &line.annotations { + span_left_margin = min(span_left_margin, ann.start_col); + span_left_margin = min(span_left_margin, ann.end_col); + } + } + if span_left_margin == usize::MAX { + span_left_margin = 0; + } + + // Right-most column any visible span points at. + let mut span_right_margin = 0; + let mut label_right_margin = 0; + let mut max_line_len = 0; + for line in &annotated_file.lines { + max_line_len = max( + max_line_len, + annotated_file.file.get_line(line.line_index - 1).map_or(0, |s| s.len()), + ); + for ann in &line.annotations { + span_right_margin = max(span_right_margin, ann.start_col); + span_right_margin = max(span_right_margin, ann.end_col); + // FIXME: account for labels not in the same line + let label_right = ann.label.as_ref().map_or(0, |l| l.len() + 1); + label_right_margin = max(label_right_margin, ann.end_col + label_right); + } + } + + let width_offset = 3 + max_line_num_len; + let code_offset = if annotated_file.multiline_depth == 0 { + width_offset + } else { + width_offset + annotated_file.multiline_depth + 1 + }; + + let column_width = if let Some(width) = self.terminal_width { + width.saturating_sub(code_offset) + } else if self.ui_testing { + DEFAULT_COLUMN_WIDTH + } else { + termize::dimensions() + .map(|(w, _)| w.saturating_sub(code_offset)) + .unwrap_or(DEFAULT_COLUMN_WIDTH) + }; + + let margin = Margin::new( + whitespace_margin, + span_left_margin, + span_right_margin, + label_right_margin, + column_width, + max_line_len, + ); + + // Next, output the annotate source for this file + for line_idx in 0..annotated_file.lines.len() { + let previous_buffer_line = buffer.num_lines(); + + let depths = self.render_source_line( + &mut buffer, + annotated_file.file.clone(), + &annotated_file.lines[line_idx], + width_offset, + code_offset, + margin, + ); + + let mut to_add = FxHashMap::default(); + + for (depth, style) in depths { + if multilines.get(&depth).is_some() { + multilines.remove(&depth); + } else { + to_add.insert(depth, style); + } + } + + // Set the multiline annotation vertical lines to the left of + // the code in this line. + for (depth, style) in &multilines { + for line in previous_buffer_line..buffer.num_lines() { + draw_multiline_line(&mut buffer, line, width_offset, *depth, *style); + } + } + // check to see if we need to print out or elide lines that come between + // this annotated line and the next one. + if line_idx < (annotated_file.lines.len() - 1) { + let line_idx_delta = annotated_file.lines[line_idx + 1].line_index + - annotated_file.lines[line_idx].line_index; + if line_idx_delta > 2 { + let last_buffer_line_num = buffer.num_lines(); + buffer.puts(last_buffer_line_num, 0, "...", Style::LineNumber); + + // Set the multiline annotation vertical lines on `...` bridging line. + for (depth, style) in &multilines { + draw_multiline_line( + &mut buffer, + last_buffer_line_num, + width_offset, + *depth, + *style, + ); + } + } else if line_idx_delta == 2 { + let unannotated_line = annotated_file + .file + .get_line(annotated_file.lines[line_idx].line_index) + .unwrap_or_else(|| Cow::from("")); + + let last_buffer_line_num = buffer.num_lines(); + + self.draw_line( + &mut buffer, + &unannotated_line, + annotated_file.lines[line_idx + 1].line_index - 1, + last_buffer_line_num, + width_offset, + code_offset, + margin, + ); + + for (depth, style) in &multilines { + draw_multiline_line( + &mut buffer, + last_buffer_line_num, + width_offset, + *depth, + *style, + ); + } + } + } + + multilines.extend(&to_add); + } + } + } + + // final step: take our styled buffer, render it, then output it + emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?; + + Ok(()) + } + + fn emit_suggestion_default( + &mut self, + suggestion: &CodeSuggestion, + level: &Level, + max_line_num_len: usize, + ) -> io::Result<()> { + let sm = match self.sm { + Some(ref sm) => sm, + None => return Ok(()), + }; + + // Render the replacements for each suggestion + let suggestions = suggestion.splice_lines(&**sm); + debug!("emit_suggestion_default: suggestions={:?}", suggestions); + + if suggestions.is_empty() { + // Suggestions coming from macros can have malformed spans. This is a heavy handed + // approach to avoid ICEs by ignoring the suggestion outright. + return Ok(()); + } + + let mut buffer = StyledBuffer::new(); + + // Render the suggestion message + let level_str = level.to_string(); + if !level_str.is_empty() { + buffer.append(0, &level_str, Style::Level(*level)); + buffer.append(0, ": ", Style::HeaderMsg); + } + self.msg_to_buffer( + &mut buffer, + &[(suggestion.msg.to_owned(), Style::NoStyle)], + max_line_num_len, + "suggestion", + Some(Style::HeaderMsg), + ); + + let mut row_num = 2; + let mut notice_capitalization = false; + for (complete, parts, only_capitalization) in suggestions.iter().take(MAX_SUGGESTIONS) { + notice_capitalization |= only_capitalization; + // Only show underline if the suggestion spans a single line and doesn't cover the + // entirety of the code output. If you have multiple replacements in the same line + // of code, show the underline. + let show_underline = !(parts.len() == 1 && parts[0].snippet.trim() == complete.trim()) + && complete.lines().count() == 1; + + let lines = sm + .span_to_lines(parts[0].span) + .expect("span_to_lines failed when emitting suggestion"); + + assert!(!lines.lines.is_empty() || parts[0].span.is_dummy()); + + let line_start = sm.lookup_char_pos(parts[0].span.lo()).line; + draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1); + let mut lines = complete.lines(); + for (line_pos, line) in lines.by_ref().take(MAX_SUGGESTION_HIGHLIGHT_LINES).enumerate() + { + // Print the span column to avoid confusion + buffer.puts( + row_num, + 0, + &self.maybe_anonymized(line_start + line_pos), + Style::LineNumber, + ); + // print the suggestion + draw_col_separator(&mut buffer, row_num, max_line_num_len + 1); + buffer.append(row_num, line, Style::NoStyle); + row_num += 1; + } + + // This offset and the ones below need to be signed to account for replacement code + // that is shorter than the original code. + let mut offsets: Vec<(usize, isize)> = Vec::new(); + // Only show an underline in the suggestions if the suggestion is not the + // entirety of the code being shown and the displayed code is not multiline. + if show_underline { + draw_col_separator(&mut buffer, row_num, max_line_num_len + 1); + for part in parts { + let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display; + let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display; + + // Do not underline the leading... + let start = part.snippet.len().saturating_sub(part.snippet.trim_start().len()); + // ...or trailing spaces. Account for substitutions containing unicode + // characters. + let sub_len: usize = part + .snippet + .trim() + .chars() + .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1)) + .sum(); + + let offset: isize = offsets + .iter() + .filter_map( + |(start, v)| if span_start_pos <= *start { None } else { Some(v) }, + ) + .sum(); + let underline_start = (span_start_pos + start) as isize + offset; + let underline_end = (span_start_pos + start + sub_len) as isize + offset; + assert!(underline_start >= 0 && underline_end >= 0); + for p in underline_start..underline_end { + buffer.putc( + row_num, + ((max_line_num_len + 3) as isize + p) as usize, + '^', + Style::UnderlinePrimary, + ); + } + // underline removals too + if underline_start == underline_end { + for p in underline_start - 1..underline_start + 1 { + buffer.putc( + row_num, + ((max_line_num_len + 3) as isize + p) as usize, + '-', + Style::UnderlineSecondary, + ); + } + } + + // length of the code after substitution + let full_sub_len = part + .snippet + .chars() + .map(|ch| unicode_width::UnicodeWidthChar::width(ch).unwrap_or(1)) + .sum::<usize>() as isize; + + // length of the code to be substituted + let snippet_len = span_end_pos as isize - span_start_pos as isize; + // For multiple substitutions, use the position *after* the previous + // substitutions have happened, only when further substitutions are + // located strictly after. + offsets.push((span_end_pos, full_sub_len - snippet_len)); + } + row_num += 1; + } + + // if we elided some lines, add an ellipsis + if lines.next().is_some() { + buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber); + } else if !show_underline { + draw_col_separator_no_space(&mut buffer, row_num, max_line_num_len + 1); + row_num += 1; + } + } + if suggestions.len() > MAX_SUGGESTIONS { + let others = suggestions.len() - MAX_SUGGESTIONS; + let msg = format!("and {} other candidate{}", others, pluralize!(others)); + buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle); + } else if notice_capitalization { + let msg = "notice the capitalization difference"; + buffer.puts(row_num, max_line_num_len + 3, &msg, Style::NoStyle); + } + emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message)?; + Ok(()) + } + + fn emit_messages_default( + &mut self, + level: &Level, + message: &[(String, Style)], + code: &Option<DiagnosticId>, + span: &MultiSpan, + children: &[SubDiagnostic], + suggestions: &[CodeSuggestion], + ) { + let max_line_num_len = if self.ui_testing { + ANONYMIZED_LINE_NUM.len() + } else { + self.get_max_line_num(span, children).to_string().len() + }; + + match self.emit_message_default(span, message, code, level, max_line_num_len, false) { + Ok(()) => { + if !children.is_empty() + || suggestions.iter().any(|s| s.style != SuggestionStyle::CompletelyHidden) + { + let mut buffer = StyledBuffer::new(); + if !self.short_message { + draw_col_separator_no_space(&mut buffer, 0, max_line_num_len + 1); + } + match emit_to_destination( + &buffer.render(), + level, + &mut self.dst, + self.short_message, + ) { + Ok(()) => (), + Err(e) => panic!("failed to emit error: {}", e), + } + } + if !self.short_message { + for child in children { + let span = child.render_span.as_ref().unwrap_or(&child.span); + if let Err(err) = self.emit_message_default( + &span, + &child.styled_message(), + &None, + &child.level, + max_line_num_len, + true, + ) { + panic!("failed to emit error: {}", err); + } + } + for sugg in suggestions { + if sugg.style == SuggestionStyle::CompletelyHidden { + // do not display this suggestion, it is meant only for tools + } else if sugg.style == SuggestionStyle::HideCodeAlways { + if let Err(e) = self.emit_message_default( + &MultiSpan::new(), + &[(sugg.msg.to_owned(), Style::HeaderMsg)], + &None, + &Level::Help, + max_line_num_len, + true, + ) { + panic!("failed to emit error: {}", e); + } + } else if let Err(e) = + self.emit_suggestion_default(sugg, &Level::Help, max_line_num_len) + { + panic!("failed to emit error: {}", e); + }; + } + } + } + Err(e) => panic!("failed to emit error: {}", e), + } + + let mut dst = self.dst.writable(); + match writeln!(dst) { + Err(e) => panic!("failed to emit error: {}", e), + _ => { + if let Err(e) = dst.flush() { + panic!("failed to emit error: {}", e) + } + } + } + } +} + +impl FileWithAnnotatedLines { + /// Preprocess all the annotations so that they are grouped by file and by line number + /// This helps us quickly iterate over the whole message (including secondary file spans) + pub fn collect_annotations( + msp: &MultiSpan, + source_map: &Option<Lrc<SourceMap>>, + ) -> Vec<FileWithAnnotatedLines> { + fn add_annotation_to_file( + file_vec: &mut Vec<FileWithAnnotatedLines>, + file: Lrc<SourceFile>, + line_index: usize, + ann: Annotation, + ) { + for slot in file_vec.iter_mut() { + // Look through each of our files for the one we're adding to + if slot.file.name == file.name { + // See if we already have a line for it + for line_slot in &mut slot.lines { + if line_slot.line_index == line_index { + line_slot.annotations.push(ann); + return; + } + } + // We don't have a line yet, create one + slot.lines.push(Line { line_index, annotations: vec![ann] }); + slot.lines.sort(); + return; + } + } + // This is the first time we're seeing the file + file_vec.push(FileWithAnnotatedLines { + file, + lines: vec![Line { line_index, annotations: vec![ann] }], + multiline_depth: 0, + }); + } + + let mut output = vec![]; + let mut multiline_annotations = vec![]; + + if let Some(ref sm) = source_map { + for span_label in msp.span_labels() { + if span_label.span.is_dummy() { + continue; + } + + let lo = sm.lookup_char_pos(span_label.span.lo()); + let mut hi = sm.lookup_char_pos(span_label.span.hi()); + + // Watch out for "empty spans". If we get a span like 6..6, we + // want to just display a `^` at 6, so convert that to + // 6..7. This is degenerate input, but it's best to degrade + // gracefully -- and the parser likes to supply a span like + // that for EOF, in particular. + + if lo.col_display == hi.col_display && lo.line == hi.line { + hi.col_display += 1; + } + + if lo.line != hi.line { + let ml = MultilineAnnotation { + depth: 1, + line_start: lo.line, + line_end: hi.line, + start_col: lo.col_display, + end_col: hi.col_display, + is_primary: span_label.is_primary, + label: span_label.label, + overlaps_exactly: false, + }; + multiline_annotations.push((lo.file, ml)); + } else { + let ann = Annotation { + start_col: lo.col_display, + end_col: hi.col_display, + is_primary: span_label.is_primary, + label: span_label.label, + annotation_type: AnnotationType::Singleline, + }; + add_annotation_to_file(&mut output, lo.file, lo.line, ann); + }; + } + } + + // Find overlapping multiline annotations, put them at different depths + multiline_annotations.sort_by_key(|&(_, ref ml)| (ml.line_start, ml.line_end)); + for (_, ann) in multiline_annotations.clone() { + for (_, a) in multiline_annotations.iter_mut() { + // Move all other multiline annotations overlapping with this one + // one level to the right. + if !(ann.same_span(a)) + && num_overlap(ann.line_start, ann.line_end, a.line_start, a.line_end, true) + { + a.increase_depth(); + } else if ann.same_span(a) && &ann != a { + a.overlaps_exactly = true; + } else { + break; + } + } + } + + let mut max_depth = 0; // max overlapping multiline spans + for (file, ann) in multiline_annotations { + max_depth = max(max_depth, ann.depth); + let mut end_ann = ann.as_end(); + if !ann.overlaps_exactly { + // avoid output like + // + // | foo( + // | _____^ + // | |_____| + // | || bar, + // | || ); + // | || ^ + // | ||______| + // | |______foo + // | baz + // + // and instead get + // + // | foo( + // | _____^ + // | | bar, + // | | ); + // | | ^ + // | | | + // | |______foo + // | baz + add_annotation_to_file(&mut output, file.clone(), ann.line_start, ann.as_start()); + // 4 is the minimum vertical length of a multiline span when presented: two lines + // of code and two lines of underline. This is not true for the special case where + // the beginning doesn't have an underline, but the current logic seems to be + // working correctly. + let middle = min(ann.line_start + 4, ann.line_end); + for line in ann.line_start + 1..middle { + // Every `|` that joins the beginning of the span (`___^`) to the end (`|__^`). + add_annotation_to_file(&mut output, file.clone(), line, ann.as_line()); + } + let line_end = ann.line_end - 1; + if middle < line_end { + add_annotation_to_file(&mut output, file.clone(), line_end, ann.as_line()); + } + } else { + end_ann.annotation_type = AnnotationType::Singleline; + } + add_annotation_to_file(&mut output, file, ann.line_end, end_ann); + } + for file_vec in output.iter_mut() { + file_vec.multiline_depth = max_depth; + } + output + } +} + +fn draw_col_separator(buffer: &mut StyledBuffer, line: usize, col: usize) { + buffer.puts(line, col, "| ", Style::LineNumber); +} + +fn draw_col_separator_no_space(buffer: &mut StyledBuffer, line: usize, col: usize) { + draw_col_separator_no_space_with_style(buffer, line, col, Style::LineNumber); +} + +fn draw_col_separator_no_space_with_style( + buffer: &mut StyledBuffer, + line: usize, + col: usize, + style: Style, +) { + buffer.putc(line, col, '|', style); +} + +fn draw_range( + buffer: &mut StyledBuffer, + symbol: char, + line: usize, + col_from: usize, + col_to: usize, + style: Style, +) { + for col in col_from..col_to { + buffer.putc(line, col, symbol, style); + } +} + +fn draw_note_separator(buffer: &mut StyledBuffer, line: usize, col: usize) { + buffer.puts(line, col, "= ", Style::LineNumber); +} + +fn draw_multiline_line( + buffer: &mut StyledBuffer, + line: usize, + offset: usize, + depth: usize, + style: Style, +) { + buffer.putc(line, offset + depth - 1, '|', style); +} + +fn num_overlap( + a_start: usize, + a_end: usize, + b_start: usize, + b_end: usize, + inclusive: bool, +) -> bool { + let extra = if inclusive { 1 } else { 0 }; + (b_start..b_end + extra).contains(&a_start) || (a_start..a_end + extra).contains(&b_start) +} +fn overlaps(a1: &Annotation, a2: &Annotation, padding: usize) -> bool { + num_overlap(a1.start_col, a1.end_col + padding, a2.start_col, a2.end_col, false) +} + +fn emit_to_destination( + rendered_buffer: &[Vec<StyledString>], + lvl: &Level, + dst: &mut Destination, + short_message: bool, +) -> io::Result<()> { + use crate::lock; + + let mut dst = dst.writable(); + + // In order to prevent error message interleaving, where multiple error lines get intermixed + // when multiple compiler processes error simultaneously, we emit errors with additional + // steps. + // + // On Unix systems, we write into a buffered terminal rather than directly to a terminal. When + // the .flush() is called we take the buffer created from the buffered writes and write it at + // one shot. Because the Unix systems use ANSI for the colors, which is a text-based styling + // scheme, this buffered approach works and maintains the styling. + // + // On Windows, styling happens through calls to a terminal API. This prevents us from using the + // same buffering approach. Instead, we use a global Windows mutex, which we acquire long + // enough to output the full error message, then we release. + let _buffer_lock = lock::acquire_global_lock("rustc_errors"); + for (pos, line) in rendered_buffer.iter().enumerate() { + for part in line { + dst.apply_style(*lvl, part.style)?; + write!(dst, "{}", part.text)?; + dst.reset()?; + } + if !short_message && (!lvl.is_failure_note() || pos != rendered_buffer.len() - 1) { + writeln!(dst)?; + } + } + dst.flush()?; + Ok(()) +} + +pub enum Destination { + Terminal(StandardStream), + Buffered(BufferWriter), + // The bool denotes whether we should be emitting ansi color codes or not + Raw(Box<(dyn Write + Send)>, bool), +} + +pub enum WritableDst<'a> { + Terminal(&'a mut StandardStream), + Buffered(&'a mut BufferWriter, Buffer), + Raw(&'a mut (dyn Write + Send)), + ColoredRaw(Ansi<&'a mut (dyn Write + Send)>), +} + +impl Destination { + fn from_stderr(color: ColorConfig) -> Destination { + let choice = color.to_color_choice(); + // On Windows we'll be performing global synchronization on the entire + // system for emitting rustc errors, so there's no need to buffer + // anything. + // + // On non-Windows we rely on the atomicity of `write` to ensure errors + // don't get all jumbled up. + if cfg!(windows) { + Terminal(StandardStream::stderr(choice)) + } else { + Buffered(BufferWriter::stderr(choice)) + } + } + + fn writable(&mut self) -> WritableDst<'_> { + match *self { + Destination::Terminal(ref mut t) => WritableDst::Terminal(t), + Destination::Buffered(ref mut t) => { + let buf = t.buffer(); + WritableDst::Buffered(t, buf) + } + Destination::Raw(ref mut t, false) => WritableDst::Raw(t), + Destination::Raw(ref mut t, true) => WritableDst::ColoredRaw(Ansi::new(t)), + } + } +} + +impl<'a> WritableDst<'a> { + fn apply_style(&mut self, lvl: Level, style: Style) -> io::Result<()> { + let mut spec = ColorSpec::new(); + match style { + Style::LineAndColumn => {} + Style::LineNumber => { + spec.set_bold(true); + spec.set_intense(true); + if cfg!(windows) { + spec.set_fg(Some(Color::Cyan)); + } else { + spec.set_fg(Some(Color::Blue)); + } + } + Style::Quotation => {} + Style::MainHeaderMsg => { + spec.set_bold(true); + if cfg!(windows) { + spec.set_intense(true).set_fg(Some(Color::White)); + } + } + Style::UnderlinePrimary | Style::LabelPrimary => { + spec = lvl.color(); + spec.set_bold(true); + } + Style::UnderlineSecondary | Style::LabelSecondary => { + spec.set_bold(true).set_intense(true); + if cfg!(windows) { + spec.set_fg(Some(Color::Cyan)); + } else { + spec.set_fg(Some(Color::Blue)); + } + } + Style::HeaderMsg | Style::NoStyle => {} + Style::Level(lvl) => { + spec = lvl.color(); + spec.set_bold(true); + } + Style::Highlight => { + spec.set_bold(true); + } + } + self.set_color(&spec) + } + + fn set_color(&mut self, color: &ColorSpec) -> io::Result<()> { + match *self { + WritableDst::Terminal(ref mut t) => t.set_color(color), + WritableDst::Buffered(_, ref mut t) => t.set_color(color), + WritableDst::ColoredRaw(ref mut t) => t.set_color(color), + WritableDst::Raw(_) => Ok(()), + } + } + + fn reset(&mut self) -> io::Result<()> { + match *self { + WritableDst::Terminal(ref mut t) => t.reset(), + WritableDst::Buffered(_, ref mut t) => t.reset(), + WritableDst::ColoredRaw(ref mut t) => t.reset(), + WritableDst::Raw(_) => Ok(()), + } + } +} + +impl<'a> Write for WritableDst<'a> { + fn write(&mut self, bytes: &[u8]) -> io::Result<usize> { + match *self { + WritableDst::Terminal(ref mut t) => t.write(bytes), + WritableDst::Buffered(_, ref mut buf) => buf.write(bytes), + WritableDst::Raw(ref mut w) => w.write(bytes), + WritableDst::ColoredRaw(ref mut t) => t.write(bytes), + } + } + + fn flush(&mut self) -> io::Result<()> { + match *self { + WritableDst::Terminal(ref mut t) => t.flush(), + WritableDst::Buffered(_, ref mut buf) => buf.flush(), + WritableDst::Raw(ref mut w) => w.flush(), + WritableDst::ColoredRaw(ref mut w) => w.flush(), + } + } +} + +impl<'a> Drop for WritableDst<'a> { + fn drop(&mut self) { + if let WritableDst::Buffered(ref mut dst, ref mut buf) = self { + drop(dst.print(buf)); + } + } +} + +/// Whether the original and suggested code are visually similar enough to warrant extra wording. +pub fn is_case_difference(sm: &SourceMap, suggested: &str, sp: Span) -> bool { + // FIXME: this should probably be extended to also account for `FO0` → `FOO` and unicode. + let found = match sm.span_to_snippet(sp) { + Ok(snippet) => snippet, + Err(e) => { + warn!("Invalid span {:?}. Err={:?}", sp, e); + return false; + } + }; + let ascii_confusables = &['c', 'f', 'i', 'k', 'o', 's', 'u', 'v', 'w', 'x', 'y', 'z']; + // All the chars that differ in capitalization are confusable (above): + let confusable = found + .chars() + .zip(suggested.chars()) + .filter(|(f, s)| f != s) + .all(|(f, s)| (ascii_confusables.contains(&f) || ascii_confusables.contains(&s))); + confusable && found.to_lowercase() == suggested.to_lowercase() + // FIXME: We sometimes suggest the same thing we already have, which is a + // bug, but be defensive against that here. + && found != suggested +} diff --git a/compiler/rustc_errors/src/json.rs b/compiler/rustc_errors/src/json.rs new file mode 100644 index 00000000000..750d36d3d89 --- /dev/null +++ b/compiler/rustc_errors/src/json.rs @@ -0,0 +1,446 @@ +//! A JSON emitter for errors. +//! +//! This works by converting errors to a simplified structural format (see the +//! structs at the start of the file) and then serializing them. These should +//! contain as much information about the error as possible. +//! +//! The format of the JSON output should be considered *unstable*. For now the +//! structs at the end of this file (Diagnostic*) specify the error format. + +// FIXME: spec the JSON output properly. + +use rustc_span::source_map::{FilePathMapping, SourceMap}; + +use crate::emitter::{Emitter, HumanReadableErrorType}; +use crate::registry::Registry; +use crate::{Applicability, DiagnosticId}; +use crate::{CodeSuggestion, SubDiagnostic}; + +use rustc_data_structures::sync::Lrc; +use rustc_span::hygiene::ExpnData; +use rustc_span::{MultiSpan, Span, SpanLabel}; +use std::io::{self, Write}; +use std::path::Path; +use std::sync::{Arc, Mutex}; +use std::vec; + +use rustc_serialize::json::{as_json, as_pretty_json}; + +#[cfg(test)] +mod tests; + +pub struct JsonEmitter { + dst: Box<dyn Write + Send>, + registry: Option<Registry>, + sm: Lrc<SourceMap>, + pretty: bool, + ui_testing: bool, + json_rendered: HumanReadableErrorType, + terminal_width: Option<usize>, + macro_backtrace: bool, +} + +impl JsonEmitter { + pub fn stderr( + registry: Option<Registry>, + source_map: Lrc<SourceMap>, + pretty: bool, + json_rendered: HumanReadableErrorType, + terminal_width: Option<usize>, + macro_backtrace: bool, + ) -> JsonEmitter { + JsonEmitter { + dst: Box::new(io::BufWriter::new(io::stderr())), + registry, + sm: source_map, + pretty, + ui_testing: false, + json_rendered, + terminal_width, + macro_backtrace, + } + } + + pub fn basic( + pretty: bool, + json_rendered: HumanReadableErrorType, + terminal_width: Option<usize>, + macro_backtrace: bool, + ) -> JsonEmitter { + let file_path_mapping = FilePathMapping::empty(); + JsonEmitter::stderr( + None, + Lrc::new(SourceMap::new(file_path_mapping)), + pretty, + json_rendered, + terminal_width, + macro_backtrace, + ) + } + + pub fn new( + dst: Box<dyn Write + Send>, + registry: Option<Registry>, + source_map: Lrc<SourceMap>, + pretty: bool, + json_rendered: HumanReadableErrorType, + terminal_width: Option<usize>, + macro_backtrace: bool, + ) -> JsonEmitter { + JsonEmitter { + dst, + registry, + sm: source_map, + pretty, + ui_testing: false, + json_rendered, + terminal_width, + macro_backtrace, + } + } + + pub fn ui_testing(self, ui_testing: bool) -> Self { + Self { ui_testing, ..self } + } +} + +impl Emitter for JsonEmitter { + fn emit_diagnostic(&mut self, diag: &crate::Diagnostic) { + let data = Diagnostic::from_errors_diagnostic(diag, self); + let result = if self.pretty { + writeln!(&mut self.dst, "{}", as_pretty_json(&data)) + } else { + writeln!(&mut self.dst, "{}", as_json(&data)) + } + .and_then(|_| self.dst.flush()); + if let Err(e) = result { + panic!("failed to print diagnostics: {:?}", e); + } + } + + fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) { + let data = ArtifactNotification { artifact: path, emit: artifact_type }; + let result = if self.pretty { + writeln!(&mut self.dst, "{}", as_pretty_json(&data)) + } else { + writeln!(&mut self.dst, "{}", as_json(&data)) + } + .and_then(|_| self.dst.flush()); + if let Err(e) = result { + panic!("failed to print notification: {:?}", e); + } + } + + fn source_map(&self) -> Option<&Lrc<SourceMap>> { + Some(&self.sm) + } + + fn should_show_explain(&self) -> bool { + match self.json_rendered { + HumanReadableErrorType::Short(_) => false, + _ => true, + } + } +} + +// The following data types are provided just for serialisation. + +#[derive(Encodable)] +struct Diagnostic { + /// The primary error message. + message: String, + code: Option<DiagnosticCode>, + /// "error: internal compiler error", "error", "warning", "note", "help". + level: &'static str, + spans: Vec<DiagnosticSpan>, + /// Associated diagnostic messages. + children: Vec<Diagnostic>, + /// The message as rustc would render it. + rendered: Option<String>, +} + +#[derive(Encodable)] +struct DiagnosticSpan { + file_name: String, + byte_start: u32, + byte_end: u32, + /// 1-based. + line_start: usize, + line_end: usize, + /// 1-based, character offset. + column_start: usize, + column_end: usize, + /// Is this a "primary" span -- meaning the point, or one of the points, + /// where the error occurred? + is_primary: bool, + /// Source text from the start of line_start to the end of line_end. + text: Vec<DiagnosticSpanLine>, + /// Label that should be placed at this location (if any) + label: Option<String>, + /// If we are suggesting a replacement, this will contain text + /// that should be sliced in atop this span. + suggested_replacement: Option<String>, + /// If the suggestion is approximate + suggestion_applicability: Option<Applicability>, + /// Macro invocations that created the code at this span, if any. + expansion: Option<Box<DiagnosticSpanMacroExpansion>>, +} + +#[derive(Encodable)] +struct DiagnosticSpanLine { + text: String, + + /// 1-based, character offset in self.text. + highlight_start: usize, + + highlight_end: usize, +} + +#[derive(Encodable)] +struct DiagnosticSpanMacroExpansion { + /// span where macro was applied to generate this code; note that + /// this may itself derive from a macro (if + /// `span.expansion.is_some()`) + span: DiagnosticSpan, + + /// name of macro that was applied (e.g., "foo!" or "#[derive(Eq)]") + macro_decl_name: String, + + /// span where macro was defined (if known) + def_site_span: DiagnosticSpan, +} + +#[derive(Encodable)] +struct DiagnosticCode { + /// The code itself. + code: String, + /// An explanation for the code. + explanation: Option<&'static str>, +} + +#[derive(Encodable)] +struct ArtifactNotification<'a> { + /// The path of the artifact. + artifact: &'a Path, + /// What kind of artifact we're emitting. + emit: &'a str, +} + +impl Diagnostic { + fn from_errors_diagnostic(diag: &crate::Diagnostic, je: &JsonEmitter) -> Diagnostic { + let sugg = diag.suggestions.iter().map(|sugg| Diagnostic { + message: sugg.msg.clone(), + code: None, + level: "help", + spans: DiagnosticSpan::from_suggestion(sugg, je), + children: vec![], + rendered: None, + }); + + // generate regular command line output and store it in the json + + // A threadsafe buffer for writing. + #[derive(Default, Clone)] + struct BufWriter(Arc<Mutex<Vec<u8>>>); + + impl Write for BufWriter { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.0.lock().unwrap().write(buf) + } + fn flush(&mut self) -> io::Result<()> { + self.0.lock().unwrap().flush() + } + } + let buf = BufWriter::default(); + let output = buf.clone(); + je.json_rendered + .new_emitter( + Box::new(buf), + Some(je.sm.clone()), + false, + je.terminal_width, + je.macro_backtrace, + ) + .ui_testing(je.ui_testing) + .emit_diagnostic(diag); + let output = Arc::try_unwrap(output.0).unwrap().into_inner().unwrap(); + let output = String::from_utf8(output).unwrap(); + + Diagnostic { + message: diag.message(), + code: DiagnosticCode::map_opt_string(diag.code.clone(), je), + level: diag.level.to_str(), + spans: DiagnosticSpan::from_multispan(&diag.span, je), + children: diag + .children + .iter() + .map(|c| Diagnostic::from_sub_diagnostic(c, je)) + .chain(sugg) + .collect(), + rendered: Some(output), + } + } + + fn from_sub_diagnostic(diag: &SubDiagnostic, je: &JsonEmitter) -> Diagnostic { + Diagnostic { + message: diag.message(), + code: None, + level: diag.level.to_str(), + spans: diag + .render_span + .as_ref() + .map(|sp| DiagnosticSpan::from_multispan(sp, je)) + .unwrap_or_else(|| DiagnosticSpan::from_multispan(&diag.span, je)), + children: vec![], + rendered: None, + } + } +} + +impl DiagnosticSpan { + fn from_span_label( + span: SpanLabel, + suggestion: Option<(&String, Applicability)>, + je: &JsonEmitter, + ) -> DiagnosticSpan { + Self::from_span_etc(span.span, span.is_primary, span.label, suggestion, je) + } + + fn from_span_etc( + span: Span, + is_primary: bool, + label: Option<String>, + suggestion: Option<(&String, Applicability)>, + je: &JsonEmitter, + ) -> DiagnosticSpan { + // obtain the full backtrace from the `macro_backtrace` + // helper; in some ways, it'd be better to expand the + // backtrace ourselves, but the `macro_backtrace` helper makes + // some decision, such as dropping some frames, and I don't + // want to duplicate that logic here. + let backtrace = span.macro_backtrace(); + DiagnosticSpan::from_span_full(span, is_primary, label, suggestion, backtrace, je) + } + + fn from_span_full( + span: Span, + is_primary: bool, + label: Option<String>, + suggestion: Option<(&String, Applicability)>, + mut backtrace: impl Iterator<Item = ExpnData>, + je: &JsonEmitter, + ) -> DiagnosticSpan { + let start = je.sm.lookup_char_pos(span.lo()); + let end = je.sm.lookup_char_pos(span.hi()); + let backtrace_step = backtrace.next().map(|bt| { + let call_site = Self::from_span_full(bt.call_site, false, None, None, backtrace, je); + let def_site_span = + Self::from_span_full(bt.def_site, false, None, None, vec![].into_iter(), je); + Box::new(DiagnosticSpanMacroExpansion { + span: call_site, + macro_decl_name: bt.kind.descr(), + def_site_span, + }) + }); + + DiagnosticSpan { + file_name: start.file.name.to_string(), + byte_start: start.file.original_relative_byte_pos(span.lo()).0, + byte_end: start.file.original_relative_byte_pos(span.hi()).0, + line_start: start.line, + line_end: end.line, + column_start: start.col.0 + 1, + column_end: end.col.0 + 1, + is_primary, + text: DiagnosticSpanLine::from_span(span, je), + suggested_replacement: suggestion.map(|x| x.0.clone()), + suggestion_applicability: suggestion.map(|x| x.1), + expansion: backtrace_step, + label, + } + } + + fn from_multispan(msp: &MultiSpan, je: &JsonEmitter) -> Vec<DiagnosticSpan> { + msp.span_labels() + .into_iter() + .map(|span_str| Self::from_span_label(span_str, None, je)) + .collect() + } + + fn from_suggestion(suggestion: &CodeSuggestion, je: &JsonEmitter) -> Vec<DiagnosticSpan> { + suggestion + .substitutions + .iter() + .flat_map(|substitution| { + substitution.parts.iter().map(move |suggestion_inner| { + let span_label = + SpanLabel { span: suggestion_inner.span, is_primary: true, label: None }; + DiagnosticSpan::from_span_label( + span_label, + Some((&suggestion_inner.snippet, suggestion.applicability)), + je, + ) + }) + }) + .collect() + } +} + +impl DiagnosticSpanLine { + fn line_from_source_file( + sf: &rustc_span::SourceFile, + index: usize, + h_start: usize, + h_end: usize, + ) -> DiagnosticSpanLine { + DiagnosticSpanLine { + text: sf.get_line(index).map_or(String::new(), |l| l.into_owned()), + highlight_start: h_start, + highlight_end: h_end, + } + } + + /// Creates a list of DiagnosticSpanLines from span - each line with any part + /// of `span` gets a DiagnosticSpanLine, with the highlight indicating the + /// `span` within the line. + fn from_span(span: Span, je: &JsonEmitter) -> Vec<DiagnosticSpanLine> { + je.sm + .span_to_lines(span) + .map(|lines| { + // We can't get any lines if the source is unavailable. + if !je.sm.ensure_source_file_source_present(lines.file.clone()) { + return vec![]; + } + + let sf = &*lines.file; + lines + .lines + .iter() + .map(|line| { + DiagnosticSpanLine::line_from_source_file( + sf, + line.line_index, + line.start_col.0 + 1, + line.end_col.0 + 1, + ) + }) + .collect() + }) + .unwrap_or_else(|_| vec![]) + } +} + +impl DiagnosticCode { + fn map_opt_string(s: Option<DiagnosticId>, je: &JsonEmitter) -> Option<DiagnosticCode> { + s.map(|s| { + let s = match s { + DiagnosticId::Error(s) => s, + DiagnosticId::Lint(s) => s, + }; + let je_result = + je.registry.as_ref().map(|registry| registry.try_find_description(&s)).unwrap(); + + DiagnosticCode { code: s, explanation: je_result.unwrap_or(None) } + }) + } +} diff --git a/compiler/rustc_errors/src/json/tests.rs b/compiler/rustc_errors/src/json/tests.rs new file mode 100644 index 00000000000..e69e868c8ed --- /dev/null +++ b/compiler/rustc_errors/src/json/tests.rs @@ -0,0 +1,204 @@ +use super::*; + +use crate::json::JsonEmitter; +use rustc_span::source_map::{FilePathMapping, SourceMap}; + +use crate::emitter::{ColorConfig, HumanReadableErrorType}; +use crate::Handler; +use rustc_serialize::json::decode; +use rustc_span::{BytePos, Span}; + +use std::str; + +#[derive(Decodable, Debug, PartialEq, Eq)] +struct TestData { + spans: Vec<SpanTestData>, +} + +#[derive(Decodable, Debug, PartialEq, Eq)] +struct SpanTestData { + pub byte_start: u32, + pub byte_end: u32, + pub line_start: u32, + pub column_start: u32, + pub line_end: u32, + pub column_end: u32, +} + +struct Shared<T> { + data: Arc<Mutex<T>>, +} + +impl<T: Write> Write for Shared<T> { + fn write(&mut self, buf: &[u8]) -> io::Result<usize> { + self.data.lock().unwrap().write(buf) + } + + fn flush(&mut self) -> io::Result<()> { + self.data.lock().unwrap().flush() + } +} + +fn with_default_session_globals(f: impl FnOnce()) { + let session_globals = rustc_span::SessionGlobals::new(rustc_span::edition::DEFAULT_EDITION); + rustc_span::SESSION_GLOBALS.set(&session_globals, f); +} + +/// Test the span yields correct positions in JSON. +fn test_positions(code: &str, span: (u32, u32), expected_output: SpanTestData) { + let expected_output = TestData { spans: vec![expected_output] }; + + with_default_session_globals(|| { + let sm = Lrc::new(SourceMap::new(FilePathMapping::empty())); + sm.new_source_file(Path::new("test.rs").to_owned().into(), code.to_owned()); + + let output = Arc::new(Mutex::new(Vec::new())); + let je = JsonEmitter::new( + Box::new(Shared { data: output.clone() }), + None, + sm, + true, + HumanReadableErrorType::Short(ColorConfig::Never), + None, + false, + ); + + let span = Span::with_root_ctxt(BytePos(span.0), BytePos(span.1)); + let handler = Handler::with_emitter(true, None, Box::new(je)); + handler.span_err(span, "foo"); + + let bytes = output.lock().unwrap(); + let actual_output = str::from_utf8(&bytes).unwrap(); + let actual_output: TestData = decode(actual_output).unwrap(); + + assert_eq!(expected_output, actual_output) + }) +} + +#[test] +fn empty() { + test_positions( + " ", + (0, 1), + SpanTestData { + byte_start: 0, + byte_end: 1, + line_start: 1, + column_start: 1, + line_end: 1, + column_end: 2, + }, + ) +} + +#[test] +fn bom() { + test_positions( + "\u{feff} ", + (0, 1), + SpanTestData { + byte_start: 3, + byte_end: 4, + line_start: 1, + column_start: 1, + line_end: 1, + column_end: 2, + }, + ) +} + +#[test] +fn lf_newlines() { + test_positions( + "\nmod foo;\nmod bar;\n", + (5, 12), + SpanTestData { + byte_start: 5, + byte_end: 12, + line_start: 2, + column_start: 5, + line_end: 3, + column_end: 3, + }, + ) +} + +#[test] +fn crlf_newlines() { + test_positions( + "\r\nmod foo;\r\nmod bar;\r\n", + (5, 12), + SpanTestData { + byte_start: 6, + byte_end: 14, + line_start: 2, + column_start: 5, + line_end: 3, + column_end: 3, + }, + ) +} + +#[test] +fn crlf_newlines_with_bom() { + test_positions( + "\u{feff}\r\nmod foo;\r\nmod bar;\r\n", + (5, 12), + SpanTestData { + byte_start: 9, + byte_end: 17, + line_start: 2, + column_start: 5, + line_end: 3, + column_end: 3, + }, + ) +} + +#[test] +fn span_before_crlf() { + test_positions( + "foo\r\nbar", + (2, 3), + SpanTestData { + byte_start: 2, + byte_end: 3, + line_start: 1, + column_start: 3, + line_end: 1, + column_end: 4, + }, + ) +} + +#[test] +fn span_on_crlf() { + test_positions( + "foo\r\nbar", + (3, 4), + SpanTestData { + byte_start: 3, + byte_end: 5, + line_start: 1, + column_start: 4, + line_end: 2, + column_end: 1, + }, + ) +} + +#[test] +fn span_after_crlf() { + test_positions( + "foo\r\nbar", + (4, 5), + SpanTestData { + byte_start: 5, + byte_end: 6, + line_start: 2, + column_start: 1, + line_end: 2, + column_end: 2, + }, + ) +} diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs new file mode 100644 index 00000000000..d4f0a9d83ef --- /dev/null +++ b/compiler/rustc_errors/src/lib.rs @@ -0,0 +1,1021 @@ +//! Diagnostics creation and emission for `rustc`. +//! +//! This module contains the code for creating and emitting diagnostics. + +#![doc(html_root_url = "https://doc.rust-lang.org/nightly/")] +#![feature(crate_visibility_modifier)] +#![feature(nll)] + +#[macro_use] +extern crate rustc_macros; + +pub use emitter::ColorConfig; + +use tracing::debug; +use Level::*; + +use emitter::{is_case_difference, Emitter, EmitterWriter}; +use registry::Registry; +use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; +use rustc_data_structures::stable_hasher::StableHasher; +use rustc_data_structures::sync::{self, Lock, Lrc}; +use rustc_data_structures::AtomicRef; +use rustc_span::source_map::SourceMap; +use rustc_span::{Loc, MultiSpan, Span}; + +use std::borrow::Cow; +use std::panic; +use std::path::Path; +use std::{error, fmt}; + +use termcolor::{Color, ColorSpec}; + +pub mod annotate_snippet_emitter_writer; +mod diagnostic; +mod diagnostic_builder; +pub mod emitter; +pub mod json; +mod lock; +pub mod registry; +mod snippet; +mod styled_buffer; +pub use snippet::Style; + +pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>; + +// `PResult` is used a lot. Make sure it doesn't unintentionally get bigger. +// (See also the comment on `DiagnosticBuilderInner`.) +#[cfg(target_arch = "x86_64")] +rustc_data_structures::static_assert_size!(PResult<'_, bool>, 16); + +/// Indicates the confidence in the correctness of a suggestion. +/// +/// All suggestions are marked with an `Applicability`. Tools use the applicability of a suggestion +/// to determine whether it should be automatically applied or if the user should be consulted +/// before applying the suggestion. +#[derive(Copy, Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +pub enum Applicability { + /// The suggestion is definitely what the user intended. This suggestion should be + /// automatically applied. + MachineApplicable, + + /// The suggestion may be what the user intended, but it is uncertain. The suggestion should + /// result in valid Rust code if it is applied. + MaybeIncorrect, + + /// The suggestion contains placeholders like `(...)` or `{ /* fields */ }`. The suggestion + /// cannot be applied automatically because it will not result in valid Rust code. The user + /// will need to fill in the placeholders. + HasPlaceholders, + + /// The applicability of the suggestion is unknown. + Unspecified, +} + +#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, Encodable, Decodable)] +pub enum SuggestionStyle { + /// Hide the suggested code when displaying this suggestion inline. + HideCodeInline, + /// Always hide the suggested code but display the message. + HideCodeAlways, + /// Do not display this suggestion in the cli output, it is only meant for tools. + CompletelyHidden, + /// Always show the suggested code. + /// This will *not* show the code if the suggestion is inline *and* the suggested code is + /// empty. + ShowCode, + /// Always show the suggested code independently. + ShowAlways, +} + +impl SuggestionStyle { + fn hide_inline(&self) -> bool { + match *self { + SuggestionStyle::ShowCode => false, + _ => true, + } + } +} + +#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +pub struct CodeSuggestion { + /// Each substitute can have multiple variants due to multiple + /// applicable suggestions + /// + /// `foo.bar` might be replaced with `a.b` or `x.y` by replacing + /// `foo` and `bar` on their own: + /// + /// ``` + /// vec![ + /// Substitution { parts: vec![(0..3, "a"), (4..7, "b")] }, + /// Substitution { parts: vec![(0..3, "x"), (4..7, "y")] }, + /// ] + /// ``` + /// + /// or by replacing the entire span: + /// + /// ``` + /// vec![ + /// Substitution { parts: vec![(0..7, "a.b")] }, + /// Substitution { parts: vec![(0..7, "x.y")] }, + /// ] + /// ``` + pub substitutions: Vec<Substitution>, + pub msg: String, + /// Visual representation of this suggestion. + pub style: SuggestionStyle, + /// Whether or not the suggestion is approximate + /// + /// Sometimes we may show suggestions with placeholders, + /// which are useful for users but not useful for + /// tools like rustfix + pub applicability: Applicability, +} + +#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +/// See the docs on `CodeSuggestion::substitutions` +pub struct Substitution { + pub parts: Vec<SubstitutionPart>, +} + +#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +pub struct SubstitutionPart { + pub span: Span, + pub snippet: String, +} + +impl CodeSuggestion { + /// Returns the assembled code suggestions, whether they should be shown with an underline + /// and whether the substitution only differs in capitalization. + pub fn splice_lines(&self, sm: &SourceMap) -> Vec<(String, Vec<SubstitutionPart>, bool)> { + use rustc_span::{CharPos, Pos}; + + fn push_trailing( + buf: &mut String, + line_opt: Option<&Cow<'_, str>>, + lo: &Loc, + hi_opt: Option<&Loc>, + ) { + let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize())); + if let Some(line) = line_opt { + if let Some(lo) = line.char_indices().map(|(i, _)| i).nth(lo) { + let hi_opt = hi_opt.and_then(|hi| line.char_indices().map(|(i, _)| i).nth(hi)); + match hi_opt { + Some(hi) if hi > lo => buf.push_str(&line[lo..hi]), + Some(_) => (), + None => buf.push_str(&line[lo..]), + } + } + if hi_opt.is_none() { + buf.push('\n'); + } + } + } + + assert!(!self.substitutions.is_empty()); + + self.substitutions + .iter() + .filter(|subst| { + // Suggestions coming from macros can have malformed spans. This is a heavy + // handed approach to avoid ICEs by ignoring the suggestion outright. + let invalid = subst.parts.iter().any(|item| sm.is_valid_span(item.span).is_err()); + if invalid { + debug!("splice_lines: suggestion contains an invalid span: {:?}", subst); + } + !invalid + }) + .cloned() + .filter_map(|mut substitution| { + // Assumption: all spans are in the same file, and all spans + // are disjoint. Sort in ascending order. + substitution.parts.sort_by_key(|part| part.span.lo()); + + // Find the bounding span. + let lo = substitution.parts.iter().map(|part| part.span.lo()).min()?; + let hi = substitution.parts.iter().map(|part| part.span.hi()).max()?; + let bounding_span = Span::with_root_ctxt(lo, hi); + // The different spans might belong to different contexts, if so ignore suggestion. + let lines = sm.span_to_lines(bounding_span).ok()?; + assert!(!lines.lines.is_empty() || bounding_span.is_dummy()); + + // We can't splice anything if the source is unavailable. + if !sm.ensure_source_file_source_present(lines.file.clone()) { + return None; + } + + // To build up the result, we do this for each span: + // - push the line segment trailing the previous span + // (at the beginning a "phantom" span pointing at the start of the line) + // - push lines between the previous and current span (if any) + // - if the previous and current span are not on the same line + // push the line segment leading up to the current span + // - splice in the span substitution + // + // Finally push the trailing line segment of the last span + let sf = &lines.file; + let mut prev_hi = sm.lookup_char_pos(bounding_span.lo()); + prev_hi.col = CharPos::from_usize(0); + let mut prev_line = + lines.lines.get(0).and_then(|line0| sf.get_line(line0.line_index)); + let mut buf = String::new(); + + for part in &substitution.parts { + let cur_lo = sm.lookup_char_pos(part.span.lo()); + if prev_hi.line == cur_lo.line { + push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo)); + } else { + push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None); + // push lines between the previous and current span (if any) + for idx in prev_hi.line..(cur_lo.line - 1) { + if let Some(line) = sf.get_line(idx) { + buf.push_str(line.as_ref()); + buf.push('\n'); + } + } + if let Some(cur_line) = sf.get_line(cur_lo.line - 1) { + let end = match cur_line.char_indices().nth(cur_lo.col.to_usize()) { + Some((i, _)) => i, + None => cur_line.len(), + }; + buf.push_str(&cur_line[..end]); + } + } + buf.push_str(&part.snippet); + prev_hi = sm.lookup_char_pos(part.span.hi()); + prev_line = sf.get_line(prev_hi.line - 1); + } + let only_capitalization = is_case_difference(sm, &buf, bounding_span); + // if the replacement already ends with a newline, don't print the next line + if !buf.ends_with('\n') { + push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None); + } + // remove trailing newlines + while buf.ends_with('\n') { + buf.pop(); + } + Some((buf, substitution.parts, only_capitalization)) + }) + .collect() + } +} + +pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker}; + +/// Signifies that the compiler died with an explicit call to `.bug` +/// or `.span_bug` rather than a failed assertion, etc. +#[derive(Copy, Clone, Debug)] +pub struct ExplicitBug; + +impl fmt::Display for ExplicitBug { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + write!(f, "parser internal bug") + } +} + +impl error::Error for ExplicitBug {} + +pub use diagnostic::{Diagnostic, DiagnosticId, DiagnosticStyledString, SubDiagnostic}; +pub use diagnostic_builder::DiagnosticBuilder; + +/// A handler deals with errors and other compiler output. +/// Certain errors (fatal, bug, unimpl) may cause immediate exit, +/// others log errors for later reporting. +pub struct Handler { + flags: HandlerFlags, + inner: Lock<HandlerInner>, +} + +/// This inner struct exists to keep it all behind a single lock; +/// this is done to prevent possible deadlocks in a multi-threaded compiler, +/// as well as inconsistent state observation. +struct HandlerInner { + flags: HandlerFlags, + /// The number of errors that have been emitted, including duplicates. + /// + /// This is not necessarily the count that's reported to the user once + /// compilation ends. + err_count: usize, + deduplicated_err_count: usize, + emitter: Box<dyn Emitter + sync::Send>, + delayed_span_bugs: Vec<Diagnostic>, + + /// This set contains the `DiagnosticId` of all emitted diagnostics to avoid + /// emitting the same diagnostic with extended help (`--teach`) twice, which + /// would be uneccessary repetition. + taught_diagnostics: FxHashSet<DiagnosticId>, + + /// Used to suggest rustc --explain <error code> + emitted_diagnostic_codes: FxHashSet<DiagnosticId>, + + /// This set contains a hash of every diagnostic that has been emitted by + /// this handler. These hashes is used to avoid emitting the same error + /// twice. + emitted_diagnostics: FxHashSet<u128>, + + /// Stashed diagnostics emitted in one stage of the compiler that may be + /// stolen by other stages (e.g. to improve them and add more information). + /// The stashed diagnostics count towards the total error count. + /// When `.abort_if_errors()` is called, these are also emitted. + stashed_diagnostics: FxIndexMap<(Span, StashKey), Diagnostic>, + + /// The warning count, used for a recap upon finishing + deduplicated_warn_count: usize, +} + +/// A key denoting where from a diagnostic was stashed. +#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)] +pub enum StashKey { + ItemNoType, +} + +fn default_track_diagnostic(_: &Diagnostic) {} + +pub static TRACK_DIAGNOSTICS: AtomicRef<fn(&Diagnostic)> = + AtomicRef::new(&(default_track_diagnostic as fn(&_))); + +#[derive(Copy, Clone, Default)] +pub struct HandlerFlags { + /// If false, warning-level lints are suppressed. + /// (rustc: see `--allow warnings` and `--cap-lints`) + pub can_emit_warnings: bool, + /// If true, error-level diagnostics are upgraded to bug-level. + /// (rustc: see `-Z treat-err-as-bug`) + pub treat_err_as_bug: Option<usize>, + /// If true, immediately emit diagnostics that would otherwise be buffered. + /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`) + pub dont_buffer_diagnostics: bool, + /// If true, immediately print bugs registered with `delay_span_bug`. + /// (rustc: see `-Z report-delayed-bugs`) + pub report_delayed_bugs: bool, + /// Show macro backtraces. + /// (rustc: see `-Z macro-backtrace`) + pub macro_backtrace: bool, + /// If true, identical diagnostics are reported only once. + pub deduplicate_diagnostics: bool, +} + +impl Drop for HandlerInner { + fn drop(&mut self) { + self.emit_stashed_diagnostics(); + + if !self.has_errors() { + let bugs = std::mem::replace(&mut self.delayed_span_bugs, Vec::new()); + let has_bugs = !bugs.is_empty(); + for bug in bugs { + self.emit_diagnostic(&bug); + } + if has_bugs { + panic!("no errors encountered even though `delay_span_bug` issued"); + } + } + } +} + +impl Handler { + pub fn with_tty_emitter( + color_config: ColorConfig, + can_emit_warnings: bool, + treat_err_as_bug: Option<usize>, + sm: Option<Lrc<SourceMap>>, + ) -> Self { + Self::with_tty_emitter_and_flags( + color_config, + sm, + HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() }, + ) + } + + pub fn with_tty_emitter_and_flags( + color_config: ColorConfig, + sm: Option<Lrc<SourceMap>>, + flags: HandlerFlags, + ) -> Self { + let emitter = Box::new(EmitterWriter::stderr( + color_config, + sm, + false, + false, + None, + flags.macro_backtrace, + )); + Self::with_emitter_and_flags(emitter, flags) + } + + pub fn with_emitter( + can_emit_warnings: bool, + treat_err_as_bug: Option<usize>, + emitter: Box<dyn Emitter + sync::Send>, + ) -> Self { + Handler::with_emitter_and_flags( + emitter, + HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() }, + ) + } + + pub fn with_emitter_and_flags( + emitter: Box<dyn Emitter + sync::Send>, + flags: HandlerFlags, + ) -> Self { + Self { + flags, + inner: Lock::new(HandlerInner { + flags, + err_count: 0, + deduplicated_err_count: 0, + deduplicated_warn_count: 0, + emitter, + delayed_span_bugs: Vec::new(), + taught_diagnostics: Default::default(), + emitted_diagnostic_codes: Default::default(), + emitted_diagnostics: Default::default(), + stashed_diagnostics: Default::default(), + }), + } + } + + // This is here to not allow mutation of flags; + // as of this writing it's only used in tests in librustc_middle. + pub fn can_emit_warnings(&self) -> bool { + self.flags.can_emit_warnings + } + + /// Resets the diagnostic error count as well as the cached emitted diagnostics. + /// + /// NOTE: *do not* call this function from rustc. It is only meant to be called from external + /// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as + /// the overall count of emitted error diagnostics. + pub fn reset_err_count(&self) { + let mut inner = self.inner.borrow_mut(); + inner.err_count = 0; + inner.deduplicated_err_count = 0; + inner.deduplicated_warn_count = 0; + + // actually free the underlying memory (which `clear` would not do) + inner.delayed_span_bugs = Default::default(); + inner.taught_diagnostics = Default::default(); + inner.emitted_diagnostic_codes = Default::default(); + inner.emitted_diagnostics = Default::default(); + inner.stashed_diagnostics = Default::default(); + } + + /// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing. + pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) { + let mut inner = self.inner.borrow_mut(); + // FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic + // if/when we have a more robust macro-friendly replacement for `(span, key)` as a key. + // See the PR for a discussion. + inner.stashed_diagnostics.insert((span, key), diag); + } + + /// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key. + pub fn steal_diagnostic(&self, span: Span, key: StashKey) -> Option<DiagnosticBuilder<'_>> { + self.inner + .borrow_mut() + .stashed_diagnostics + .remove(&(span, key)) + .map(|diag| DiagnosticBuilder::new_diagnostic(self, diag)) + } + + /// Emit all stashed diagnostics. + pub fn emit_stashed_diagnostics(&self) { + self.inner.borrow_mut().emit_stashed_diagnostics(); + } + + /// Construct a dummy builder with `Level::Cancelled`. + /// + /// Using this will neither report anything to the user (e.g. a warning), + /// nor will compilation cancel as a result. + pub fn struct_dummy(&self) -> DiagnosticBuilder<'_> { + DiagnosticBuilder::new(self, Level::Cancelled, "") + } + + /// Construct a builder at the `Warning` level at the given `span` and with the `msg`. + pub fn struct_span_warn(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> { + let mut result = self.struct_warn(msg); + result.set_span(span); + result + } + + /// Construct a builder at the `Warning` level at the given `span` and with the `msg`. + /// Also include a code. + pub fn struct_span_warn_with_code( + &self, + span: impl Into<MultiSpan>, + msg: &str, + code: DiagnosticId, + ) -> DiagnosticBuilder<'_> { + let mut result = self.struct_span_warn(span, msg); + result.code(code); + result + } + + /// Construct a builder at the `Warning` level with the `msg`. + pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> { + let mut result = DiagnosticBuilder::new(self, Level::Warning, msg); + if !self.flags.can_emit_warnings { + result.cancel(); + } + result + } + + /// Construct a builder at the `Error` level at the given `span` and with the `msg`. + pub fn struct_span_err(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> { + let mut result = self.struct_err(msg); + result.set_span(span); + result + } + + /// Construct a builder at the `Error` level at the given `span`, with the `msg`, and `code`. + pub fn struct_span_err_with_code( + &self, + span: impl Into<MultiSpan>, + msg: &str, + code: DiagnosticId, + ) -> DiagnosticBuilder<'_> { + let mut result = self.struct_span_err(span, msg); + result.code(code); + result + } + + /// Construct a builder at the `Error` level with the `msg`. + // FIXME: This method should be removed (every error should have an associated error code). + pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> { + DiagnosticBuilder::new(self, Level::Error, msg) + } + + /// Construct a builder at the `Error` level with the `msg` and the `code`. + pub fn struct_err_with_code(&self, msg: &str, code: DiagnosticId) -> DiagnosticBuilder<'_> { + let mut result = self.struct_err(msg); + result.code(code); + result + } + + /// Construct a builder at the `Fatal` level at the given `span` and with the `msg`. + pub fn struct_span_fatal( + &self, + span: impl Into<MultiSpan>, + msg: &str, + ) -> DiagnosticBuilder<'_> { + let mut result = self.struct_fatal(msg); + result.set_span(span); + result + } + + /// Construct a builder at the `Fatal` level at the given `span`, with the `msg`, and `code`. + pub fn struct_span_fatal_with_code( + &self, + span: impl Into<MultiSpan>, + msg: &str, + code: DiagnosticId, + ) -> DiagnosticBuilder<'_> { + let mut result = self.struct_span_fatal(span, msg); + result.code(code); + result + } + + /// Construct a builder at the `Error` level with the `msg`. + pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> { + DiagnosticBuilder::new(self, Level::Fatal, msg) + } + + /// Construct a builder at the `Help` level with the `msg`. + pub fn struct_help(&self, msg: &str) -> DiagnosticBuilder<'_> { + DiagnosticBuilder::new(self, Level::Help, msg) + } + + /// Construct a builder at the `Note` level with the `msg`. + pub fn struct_note_without_error(&self, msg: &str) -> DiagnosticBuilder<'_> { + DiagnosticBuilder::new(self, Level::Note, msg) + } + + pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: &str) -> FatalError { + self.emit_diag_at_span(Diagnostic::new(Fatal, msg), span); + FatalError + } + + pub fn span_fatal_with_code( + &self, + span: impl Into<MultiSpan>, + msg: &str, + code: DiagnosticId, + ) -> FatalError { + self.emit_diag_at_span(Diagnostic::new_with_code(Fatal, Some(code), msg), span); + FatalError + } + + pub fn span_err(&self, span: impl Into<MultiSpan>, msg: &str) { + self.emit_diag_at_span(Diagnostic::new(Error, msg), span); + } + + pub fn span_err_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) { + self.emit_diag_at_span(Diagnostic::new_with_code(Error, Some(code), msg), span); + } + + pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: &str) { + self.emit_diag_at_span(Diagnostic::new(Warning, msg), span); + } + + pub fn span_warn_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) { + self.emit_diag_at_span(Diagnostic::new_with_code(Warning, Some(code), msg), span); + } + + pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: &str) -> ! { + self.inner.borrow_mut().span_bug(span, msg) + } + + #[track_caller] + pub fn delay_span_bug(&self, span: impl Into<MultiSpan>, msg: &str) { + self.inner.borrow_mut().delay_span_bug(span, msg) + } + + pub fn span_bug_no_panic(&self, span: impl Into<MultiSpan>, msg: &str) { + self.emit_diag_at_span(Diagnostic::new(Bug, msg), span); + } + + pub fn span_note_without_error(&self, span: impl Into<MultiSpan>, msg: &str) { + self.emit_diag_at_span(Diagnostic::new(Note, msg), span); + } + + pub fn span_note_diag(&self, span: Span, msg: &str) -> DiagnosticBuilder<'_> { + let mut db = DiagnosticBuilder::new(self, Note, msg); + db.set_span(span); + db + } + + pub fn failure(&self, msg: &str) { + self.inner.borrow_mut().failure(msg); + } + + pub fn fatal(&self, msg: &str) -> FatalError { + self.inner.borrow_mut().fatal(msg) + } + + pub fn err(&self, msg: &str) { + self.inner.borrow_mut().err(msg); + } + + pub fn warn(&self, msg: &str) { + let mut db = DiagnosticBuilder::new(self, Warning, msg); + db.emit(); + } + + pub fn note_without_error(&self, msg: &str) { + DiagnosticBuilder::new(self, Note, msg).emit(); + } + + pub fn bug(&self, msg: &str) -> ! { + self.inner.borrow_mut().bug(msg) + } + + pub fn err_count(&self) -> usize { + self.inner.borrow().err_count() + } + + pub fn has_errors(&self) -> bool { + self.inner.borrow().has_errors() + } + pub fn has_errors_or_delayed_span_bugs(&self) -> bool { + self.inner.borrow().has_errors_or_delayed_span_bugs() + } + + pub fn print_error_count(&self, registry: &Registry) { + self.inner.borrow_mut().print_error_count(registry) + } + + pub fn abort_if_errors(&self) { + self.inner.borrow_mut().abort_if_errors() + } + + /// `true` if we haven't taught a diagnostic with this code already. + /// The caller must then teach the user about such a diagnostic. + /// + /// Used to suppress emitting the same error multiple times with extended explanation when + /// calling `-Zteach`. + pub fn must_teach(&self, code: &DiagnosticId) -> bool { + self.inner.borrow_mut().must_teach(code) + } + + pub fn force_print_diagnostic(&self, db: Diagnostic) { + self.inner.borrow_mut().force_print_diagnostic(db) + } + + pub fn emit_diagnostic(&self, diagnostic: &Diagnostic) { + self.inner.borrow_mut().emit_diagnostic(diagnostic) + } + + fn emit_diag_at_span(&self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) { + let mut inner = self.inner.borrow_mut(); + inner.emit_diagnostic(diag.set_span(sp)); + } + + pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) { + self.inner.borrow_mut().emit_artifact_notification(path, artifact_type) + } + + pub fn delay_as_bug(&self, diagnostic: Diagnostic) { + self.inner.borrow_mut().delay_as_bug(diagnostic) + } +} + +impl HandlerInner { + fn must_teach(&mut self, code: &DiagnosticId) -> bool { + self.taught_diagnostics.insert(code.clone()) + } + + fn force_print_diagnostic(&mut self, db: Diagnostic) { + self.emitter.emit_diagnostic(&db); + } + + /// Emit all stashed diagnostics. + fn emit_stashed_diagnostics(&mut self) { + let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>(); + diags.iter().for_each(|diag| self.emit_diagnostic(diag)); + } + + fn emit_diagnostic(&mut self, diagnostic: &Diagnostic) { + if diagnostic.cancelled() { + return; + } + + if diagnostic.level == Warning && !self.flags.can_emit_warnings { + return; + } + + (*TRACK_DIAGNOSTICS)(diagnostic); + + if let Some(ref code) = diagnostic.code { + self.emitted_diagnostic_codes.insert(code.clone()); + } + + let already_emitted = |this: &mut Self| { + use std::hash::Hash; + let mut hasher = StableHasher::new(); + diagnostic.hash(&mut hasher); + let diagnostic_hash = hasher.finish(); + !this.emitted_diagnostics.insert(diagnostic_hash) + }; + + // Only emit the diagnostic if we've been asked to deduplicate and + // haven't already emitted an equivalent diagnostic. + if !(self.flags.deduplicate_diagnostics && already_emitted(self)) { + self.emitter.emit_diagnostic(diagnostic); + if diagnostic.is_error() { + self.deduplicated_err_count += 1; + } else if diagnostic.level == Warning { + self.deduplicated_warn_count += 1; + } + } + if diagnostic.is_error() { + self.bump_err_count(); + } + } + + fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) { + self.emitter.emit_artifact_notification(path, artifact_type); + } + + fn treat_err_as_bug(&self) -> bool { + self.flags.treat_err_as_bug.map(|c| self.err_count() >= c).unwrap_or(false) + } + + fn print_error_count(&mut self, registry: &Registry) { + self.emit_stashed_diagnostics(); + + let warnings = match self.deduplicated_warn_count { + 0 => String::new(), + 1 => "1 warning emitted".to_string(), + count => format!("{} warnings emitted", count), + }; + let errors = match self.deduplicated_err_count { + 0 => String::new(), + 1 => "aborting due to previous error".to_string(), + count => format!("aborting due to {} previous errors", count), + }; + if self.treat_err_as_bug() { + return; + } + + match (errors.len(), warnings.len()) { + (0, 0) => return, + (0, _) => self.emit_diagnostic(&Diagnostic::new(Level::Warning, &warnings)), + (_, 0) => { + let _ = self.fatal(&errors); + } + (_, _) => { + let _ = self.fatal(&format!("{}; {}", &errors, &warnings)); + } + } + + let can_show_explain = self.emitter.should_show_explain(); + let are_there_diagnostics = !self.emitted_diagnostic_codes.is_empty(); + if can_show_explain && are_there_diagnostics { + let mut error_codes = self + .emitted_diagnostic_codes + .iter() + .filter_map(|x| match &x { + DiagnosticId::Error(s) => { + if let Ok(Some(_explanation)) = registry.try_find_description(s) { + Some(s.clone()) + } else { + None + } + } + _ => None, + }) + .collect::<Vec<_>>(); + if !error_codes.is_empty() { + error_codes.sort(); + if error_codes.len() > 1 { + let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() }; + self.failure(&format!( + "Some errors have detailed explanations: {}{}", + error_codes[..limit].join(", "), + if error_codes.len() > 9 { "..." } else { "." } + )); + self.failure(&format!( + "For more information about an error, try \ + `rustc --explain {}`.", + &error_codes[0] + )); + } else { + self.failure(&format!( + "For more information about this error, try \ + `rustc --explain {}`.", + &error_codes[0] + )); + } + } + } + } + + fn err_count(&self) -> usize { + self.err_count + self.stashed_diagnostics.len() + } + + fn has_errors(&self) -> bool { + self.err_count() > 0 + } + fn has_errors_or_delayed_span_bugs(&self) -> bool { + self.has_errors() || !self.delayed_span_bugs.is_empty() + } + + fn abort_if_errors(&mut self) { + self.emit_stashed_diagnostics(); + + if self.has_errors() { + FatalError.raise(); + } + } + + fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) -> ! { + self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp); + panic!(ExplicitBug); + } + + fn emit_diag_at_span(&mut self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) { + self.emit_diagnostic(diag.set_span(sp)); + } + + #[track_caller] + fn delay_span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) { + // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before + // incrementing `err_count` by one, so we need to +1 the comparing. + // FIXME: Would be nice to increment err_count in a more coherent way. + if self.flags.treat_err_as_bug.map(|c| self.err_count() + 1 >= c).unwrap_or(false) { + // FIXME: don't abort here if report_delayed_bugs is off + self.span_bug(sp, msg); + } + let mut diagnostic = Diagnostic::new(Level::Bug, msg); + diagnostic.set_span(sp.into()); + diagnostic.note(&format!("delayed at {}", std::panic::Location::caller())); + self.delay_as_bug(diagnostic) + } + + fn failure(&mut self, msg: &str) { + self.emit_diagnostic(&Diagnostic::new(FailureNote, msg)); + } + + fn fatal(&mut self, msg: &str) -> FatalError { + self.emit_error(Fatal, msg); + FatalError + } + + fn err(&mut self, msg: &str) { + self.emit_error(Error, msg); + } + + /// Emit an error; level should be `Error` or `Fatal`. + fn emit_error(&mut self, level: Level, msg: &str) { + if self.treat_err_as_bug() { + self.bug(msg); + } + self.emit_diagnostic(&Diagnostic::new(level, msg)); + } + + fn bug(&mut self, msg: &str) -> ! { + self.emit_diagnostic(&Diagnostic::new(Bug, msg)); + panic!(ExplicitBug); + } + + fn delay_as_bug(&mut self, diagnostic: Diagnostic) { + if self.flags.report_delayed_bugs { + self.emit_diagnostic(&diagnostic); + } + self.delayed_span_bugs.push(diagnostic); + } + + fn bump_err_count(&mut self) { + self.err_count += 1; + self.panic_if_treat_err_as_bug(); + } + + fn panic_if_treat_err_as_bug(&self) { + if self.treat_err_as_bug() { + let s = match (self.err_count(), self.flags.treat_err_as_bug.unwrap_or(0)) { + (0, _) => return, + (1, 1) => "aborting due to `-Z treat-err-as-bug=1`".to_string(), + (1, _) => return, + (count, as_bug) => format!( + "aborting after {} errors due to `-Z treat-err-as-bug={}`", + count, as_bug, + ), + }; + panic!(s); + } + } +} + +#[derive(Copy, PartialEq, Clone, Hash, Debug, Encodable, Decodable)] +pub enum Level { + Bug, + Fatal, + Error, + Warning, + Note, + Help, + Cancelled, + FailureNote, +} + +impl fmt::Display for Level { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + self.to_str().fmt(f) + } +} + +impl Level { + fn color(self) -> ColorSpec { + let mut spec = ColorSpec::new(); + match self { + Bug | Fatal | Error => { + spec.set_fg(Some(Color::Red)).set_intense(true); + } + Warning => { + spec.set_fg(Some(Color::Yellow)).set_intense(cfg!(windows)); + } + Note => { + spec.set_fg(Some(Color::Green)).set_intense(true); + } + Help => { + spec.set_fg(Some(Color::Cyan)).set_intense(true); + } + FailureNote => {} + Cancelled => unreachable!(), + } + spec + } + + pub fn to_str(self) -> &'static str { + match self { + Bug => "error: internal compiler error", + Fatal | Error => "error", + Warning => "warning", + Note => "note", + Help => "help", + FailureNote => "failure-note", + Cancelled => panic!("Shouldn't call on cancelled error"), + } + } + + pub fn is_failure_note(&self) -> bool { + match *self { + FailureNote => true, + _ => false, + } + } +} + +#[macro_export] +macro_rules! pluralize { + ($x:expr) => { + if $x != 1 { "s" } else { "" } + }; +} + +// Useful type to use with `Result<>` indicate that an error has already +// been reported to the user, so no need to continue checking. +#[derive(Clone, Copy, Debug, Encodable, Decodable, Hash, PartialEq, Eq)] +pub struct ErrorReported; + +rustc_data_structures::impl_stable_hash_via_hash!(ErrorReported); diff --git a/compiler/rustc_errors/src/lock.rs b/compiler/rustc_errors/src/lock.rs new file mode 100644 index 00000000000..a73472021d4 --- /dev/null +++ b/compiler/rustc_errors/src/lock.rs @@ -0,0 +1,93 @@ +//! Bindings to acquire a global named lock. +//! +//! This is intended to be used to synchronize multiple compiler processes to +//! ensure that we can output complete errors without interleaving on Windows. +//! Note that this is currently only needed for allowing only one 32-bit MSVC +//! linker to execute at once on MSVC hosts, so this is only implemented for +//! `cfg(windows)`. Also note that this may not always be used on Windows, +//! only when targeting 32-bit MSVC. +//! +//! For more information about why this is necessary, see where this is called. + +use std::any::Any; + +#[cfg(windows)] +pub fn acquire_global_lock(name: &str) -> Box<dyn Any> { + use std::ffi::CString; + use std::io; + + use winapi::shared::ntdef::HANDLE; + use winapi::um::handleapi::CloseHandle; + use winapi::um::synchapi::{CreateMutexA, ReleaseMutex, WaitForSingleObject}; + use winapi::um::winbase::{INFINITE, WAIT_ABANDONED, WAIT_OBJECT_0}; + + struct Handle(HANDLE); + + impl Drop for Handle { + fn drop(&mut self) { + unsafe { + CloseHandle(self.0); + } + } + } + + struct Guard(Handle); + + impl Drop for Guard { + fn drop(&mut self) { + unsafe { + ReleaseMutex((self.0).0); + } + } + } + + let cname = CString::new(name).unwrap(); + unsafe { + // Create a named mutex, with no security attributes and also not + // acquired when we create it. + // + // This will silently create one if it doesn't already exist, or it'll + // open up a handle to one if it already exists. + let mutex = CreateMutexA(std::ptr::null_mut(), 0, cname.as_ptr()); + if mutex.is_null() { + panic!( + "failed to create global mutex named `{}`: {}", + name, + io::Error::last_os_error() + ); + } + let mutex = Handle(mutex); + + // Acquire the lock through `WaitForSingleObject`. + // + // A return value of `WAIT_OBJECT_0` means we successfully acquired it. + // + // A return value of `WAIT_ABANDONED` means that the previous holder of + // the thread exited without calling `ReleaseMutex`. This can happen, + // for example, when the compiler crashes or is interrupted via ctrl-c + // or the like. In this case, however, we are still transferred + // ownership of the lock so we continue. + // + // If an error happens.. well... that's surprising! + match WaitForSingleObject(mutex.0, INFINITE) { + WAIT_OBJECT_0 | WAIT_ABANDONED => {} + code => { + panic!( + "WaitForSingleObject failed on global mutex named \ + `{}`: {} (ret={:x})", + name, + io::Error::last_os_error(), + code + ); + } + } + + // Return a guard which will call `ReleaseMutex` when dropped. + Box::new(Guard(mutex)) + } +} + +#[cfg(not(windows))] +pub fn acquire_global_lock(_name: &str) -> Box<dyn Any> { + Box::new(()) +} diff --git a/compiler/rustc_errors/src/registry.rs b/compiler/rustc_errors/src/registry.rs new file mode 100644 index 00000000000..b1d770d5bd5 --- /dev/null +++ b/compiler/rustc_errors/src/registry.rs @@ -0,0 +1,29 @@ +use rustc_data_structures::fx::FxHashMap; + +#[derive(Debug)] +pub struct InvalidErrorCode; + +#[derive(Clone)] +pub struct Registry { + long_descriptions: FxHashMap<&'static str, Option<&'static str>>, +} + +impl Registry { + pub fn new(long_descriptions: &[(&'static str, Option<&'static str>)]) -> Registry { + Registry { long_descriptions: long_descriptions.iter().copied().collect() } + } + + /// This will panic if an invalid error code is passed in + pub fn find_description(&self, code: &str) -> Option<&'static str> { + self.long_descriptions[code] + } + /// Returns `InvalidErrorCode` if the code requested does not exist in the + /// registry. Otherwise, returns an `Option` where `None` means the error + /// code is valid but has no extended information. + pub fn try_find_description( + &self, + code: &str, + ) -> Result<Option<&'static str>, InvalidErrorCode> { + self.long_descriptions.get(code).copied().ok_or(InvalidErrorCode) + } +} diff --git a/compiler/rustc_errors/src/snippet.rs b/compiler/rustc_errors/src/snippet.rs new file mode 100644 index 00000000000..160bf577799 --- /dev/null +++ b/compiler/rustc_errors/src/snippet.rs @@ -0,0 +1,190 @@ +// Code for annotating snippets. + +use crate::Level; + +#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)] +pub struct Line { + pub line_index: usize, + pub annotations: Vec<Annotation>, +} + +#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)] +pub struct MultilineAnnotation { + pub depth: usize, + pub line_start: usize, + pub line_end: usize, + pub start_col: usize, + pub end_col: usize, + pub is_primary: bool, + pub label: Option<String>, + pub overlaps_exactly: bool, +} + +impl MultilineAnnotation { + pub fn increase_depth(&mut self) { + self.depth += 1; + } + + /// Compare two `MultilineAnnotation`s considering only the `Span` they cover. + pub fn same_span(&self, other: &MultilineAnnotation) -> bool { + self.line_start == other.line_start + && self.line_end == other.line_end + && self.start_col == other.start_col + && self.end_col == other.end_col + } + + pub fn as_start(&self) -> Annotation { + Annotation { + start_col: self.start_col, + end_col: self.start_col + 1, + is_primary: self.is_primary, + label: None, + annotation_type: AnnotationType::MultilineStart(self.depth), + } + } + + pub fn as_end(&self) -> Annotation { + Annotation { + start_col: self.end_col.saturating_sub(1), + end_col: self.end_col, + is_primary: self.is_primary, + label: self.label.clone(), + annotation_type: AnnotationType::MultilineEnd(self.depth), + } + } + + pub fn as_line(&self) -> Annotation { + Annotation { + start_col: 0, + end_col: 0, + is_primary: self.is_primary, + label: None, + annotation_type: AnnotationType::MultilineLine(self.depth), + } + } +} + +#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)] +pub enum AnnotationType { + /// Annotation under a single line of code + Singleline, + + /// Annotation enclosing the first and last character of a multiline span + Multiline(MultilineAnnotation), + + // The Multiline type above is replaced with the following three in order + // to reuse the current label drawing code. + // + // Each of these corresponds to one part of the following diagram: + // + // x | foo(1 + bar(x, + // | _________^ < MultilineStart + // x | | y), < MultilineLine + // | |______________^ label < MultilineEnd + // x | z); + /// Annotation marking the first character of a fully shown multiline span + MultilineStart(usize), + /// Annotation marking the last character of a fully shown multiline span + MultilineEnd(usize), + /// Line at the left enclosing the lines of a fully shown multiline span + // Just a placeholder for the drawing algorithm, to know that it shouldn't skip the first 4 + // and last 2 lines of code. The actual line is drawn in `emit_message_default` and not in + // `draw_multiline_line`. + MultilineLine(usize), +} + +#[derive(Clone, Debug, PartialOrd, Ord, PartialEq, Eq)] +pub struct Annotation { + /// Start column, 0-based indexing -- counting *characters*, not + /// utf-8 bytes. Note that it is important that this field goes + /// first, so that when we sort, we sort orderings by start + /// column. + pub start_col: usize, + + /// End column within the line (exclusive) + pub end_col: usize, + + /// Is this annotation derived from primary span + pub is_primary: bool, + + /// Optional label to display adjacent to the annotation. + pub label: Option<String>, + + /// Is this a single line, multiline or multiline span minimized down to a + /// smaller span. + pub annotation_type: AnnotationType, +} + +impl Annotation { + /// Whether this annotation is a vertical line placeholder. + pub fn is_line(&self) -> bool { + if let AnnotationType::MultilineLine(_) = self.annotation_type { true } else { false } + } + + pub fn is_multiline(&self) -> bool { + match self.annotation_type { + AnnotationType::Multiline(_) + | AnnotationType::MultilineStart(_) + | AnnotationType::MultilineLine(_) + | AnnotationType::MultilineEnd(_) => true, + _ => false, + } + } + + pub fn len(&self) -> usize { + // Account for usize underflows + if self.end_col > self.start_col { + self.end_col - self.start_col + } else { + self.start_col - self.end_col + } + } + + pub fn has_label(&self) -> bool { + if let Some(ref label) = self.label { + // Consider labels with no text as effectively not being there + // to avoid weird output with unnecessary vertical lines, like: + // + // X | fn foo(x: u32) { + // | -------^------ + // | | | + // | | + // | + // + // Note that this would be the complete output users would see. + !label.is_empty() + } else { + false + } + } + + pub fn takes_space(&self) -> bool { + // Multiline annotations always have to keep vertical space. + match self.annotation_type { + AnnotationType::MultilineStart(_) | AnnotationType::MultilineEnd(_) => true, + _ => false, + } + } +} + +#[derive(Debug)] +pub struct StyledString { + pub text: String, + pub style: Style, +} + +#[derive(Copy, Clone, Debug, PartialEq, Hash, Encodable, Decodable)] +pub enum Style { + MainHeaderMsg, + HeaderMsg, + LineAndColumn, + LineNumber, + Quotation, + UnderlinePrimary, + UnderlineSecondary, + LabelPrimary, + LabelSecondary, + NoStyle, + Level(Level), + Highlight, +} diff --git a/compiler/rustc_errors/src/styled_buffer.rs b/compiler/rustc_errors/src/styled_buffer.rs new file mode 100644 index 00000000000..f2d255d7d95 --- /dev/null +++ b/compiler/rustc_errors/src/styled_buffer.rs @@ -0,0 +1,151 @@ +// Code for creating styled buffers + +use crate::snippet::{Style, StyledString}; + +#[derive(Debug)] +pub struct StyledBuffer { + text: Vec<Vec<char>>, + styles: Vec<Vec<Style>>, +} + +impl StyledBuffer { + pub fn new() -> StyledBuffer { + StyledBuffer { text: vec![], styles: vec![] } + } + + fn replace_tabs(&mut self) { + for (line_pos, line) in self.text.iter_mut().enumerate() { + let mut tab_pos = vec![]; + for (pos, c) in line.iter().enumerate() { + if *c == '\t' { + tab_pos.push(pos); + } + } + // start with the tabs at the end of the line to replace them with 4 space chars + for pos in tab_pos.iter().rev() { + assert_eq!(line.remove(*pos), '\t'); + // fix the position of the style to match up after replacing the tabs + let s = self.styles[line_pos].remove(*pos); + for _ in 0..4 { + line.insert(*pos, ' '); + self.styles[line_pos].insert(*pos, s); + } + } + } + } + + pub fn render(&mut self) -> Vec<Vec<StyledString>> { + let mut output: Vec<Vec<StyledString>> = vec![]; + let mut styled_vec: Vec<StyledString> = vec![]; + + // before we render, replace tabs with spaces + self.replace_tabs(); + + for (row, row_style) in self.text.iter().zip(&self.styles) { + let mut current_style = Style::NoStyle; + let mut current_text = String::new(); + + for (&c, &s) in row.iter().zip(row_style) { + if s != current_style { + if !current_text.is_empty() { + styled_vec.push(StyledString { text: current_text, style: current_style }); + } + current_style = s; + current_text = String::new(); + } + current_text.push(c); + } + if !current_text.is_empty() { + styled_vec.push(StyledString { text: current_text, style: current_style }); + } + + // We're done with the row, push and keep going + output.push(styled_vec); + + styled_vec = vec![]; + } + + output + } + + fn ensure_lines(&mut self, line: usize) { + while line >= self.text.len() { + self.text.push(vec![]); + self.styles.push(vec![]); + } + } + + pub fn putc(&mut self, line: usize, col: usize, chr: char, style: Style) { + self.ensure_lines(line); + if col < self.text[line].len() { + self.text[line][col] = chr; + self.styles[line][col] = style; + } else { + let mut i = self.text[line].len(); + while i < col { + self.text[line].push(' '); + self.styles[line].push(Style::NoStyle); + i += 1; + } + self.text[line].push(chr); + self.styles[line].push(style); + } + } + + pub fn puts(&mut self, line: usize, col: usize, string: &str, style: Style) { + let mut n = col; + for c in string.chars() { + self.putc(line, n, c, style); + n += 1; + } + } + + pub fn prepend(&mut self, line: usize, string: &str, style: Style) { + self.ensure_lines(line); + let string_len = string.chars().count(); + + // Push the old content over to make room for new content + for _ in 0..string_len { + self.styles[line].insert(0, Style::NoStyle); + self.text[line].insert(0, ' '); + } + + self.puts(line, 0, string, style); + } + + pub fn append(&mut self, line: usize, string: &str, style: Style) { + if line >= self.text.len() { + self.puts(line, 0, string, style); + } else { + let col = self.text[line].len(); + self.puts(line, col, string, style); + } + } + + pub fn num_lines(&self) -> usize { + self.text.len() + } + + pub fn set_style_range( + &mut self, + line: usize, + col_start: usize, + col_end: usize, + style: Style, + overwrite: bool, + ) { + for col in col_start..col_end { + self.set_style(line, col, style, overwrite); + } + } + + pub fn set_style(&mut self, line: usize, col: usize, style: Style, overwrite: bool) { + if let Some(ref mut line) = self.styles.get_mut(line) { + if let Some(s) = line.get_mut(col) { + if *s == Style::NoStyle || *s == Style::Quotation || overwrite { + *s = style; + } + } + } + } +} |