1 //! Emit diagnostics using the `annotate-snippets` library
3 //! This is the equivalent of `./emitter.rs` but making use of the
4 //! [`annotate-snippets`][annotate_snippets] library instead of building the output ourselves.
6 //! [annotate_snippets]: https://docs.rs/crate/annotate-snippets/
8 use crate::emitter::FileWithAnnotatedLines;
9 use crate::snippet::Line;
10 use crate::{CodeSuggestion, Diagnostic, DiagnosticId, Emitter, Level, SubDiagnostic};
11 use annotate_snippets::display_list::{DisplayList, FormatOptions};
12 use annotate_snippets::snippet::*;
13 use rustc_data_structures::sync::Lrc;
14 use rustc_span::source_map::SourceMap;
15 use rustc_span::{MultiSpan, SourceFile};
17 /// Generates diagnostics using annotate-snippet
18 pub struct AnnotateSnippetEmitterWriter {
19 source_map: Option<Lrc<SourceMap>>,
20 /// If true, hides the longer explanation text
22 /// If true, will normalize line numbers with `LL` to prevent noise in UI test diffs.
25 macro_backtrace: bool,
28 impl Emitter for AnnotateSnippetEmitterWriter {
29 /// The entry point for the diagnostics generation
30 fn emit_diagnostic(&mut self, diag: &Diagnostic) {
31 let mut children = diag.children.clone();
32 let (mut primary_span, suggestions) = self.primary_span_formatted(&diag);
34 self.fix_multispans_in_extern_macros_and_render_macro_backtrace(
42 self.emit_messages_default(
44 diag.message().to_string(),
52 fn source_map(&self) -> Option<&Lrc<SourceMap>> {
53 self.source_map.as_ref()
56 fn should_show_explain(&self) -> bool {
61 /// Provides the source string for the given `line` of `file`
62 fn source_string(file: Lrc<SourceFile>, line: &Line) -> String {
63 file.get_line(line.line_index - 1).map(|a| a.to_string()).unwrap_or_default()
66 /// Maps `Diagnostic::Level` to `snippet::AnnotationType`
67 fn annotation_type_for_level(level: Level) -> AnnotationType {
69 Level::Bug | Level::DelayedBug | Level::Fatal | Level::Error { .. } => {
72 Level::Warning => AnnotationType::Warning,
73 Level::Note | Level::OnceNote => AnnotationType::Note,
74 Level::Help => AnnotationType::Help,
75 // FIXME(#59346): Not sure how to map this level
76 Level::FailureNote => AnnotationType::Error,
77 Level::Allow => panic!("Should not call with Allow"),
78 Level::Expect(_) => panic!("Should not call with Expect"),
82 impl AnnotateSnippetEmitterWriter {
84 source_map: Option<Lrc<SourceMap>>,
86 macro_backtrace: bool,
88 Self { source_map, short_message, ui_testing: false, macro_backtrace }
91 /// Allows to modify `Self` to enable or disable the `ui_testing` flag.
93 /// If this is set to true, line numbers will be normalized as `LL` in the output.
94 pub fn ui_testing(mut self, ui_testing: bool) -> Self {
95 self.ui_testing = ui_testing;
99 fn emit_messages_default(
103 code: &Option<DiagnosticId>,
105 _children: &[SubDiagnostic],
106 _suggestions: &[CodeSuggestion],
108 if let Some(source_map) = &self.source_map {
109 // Make sure our primary file comes first
110 let primary_lo = if let Some(ref primary_span) = msp.primary_span().as_ref() {
111 if primary_span.is_dummy() {
112 // FIXME(#59346): Not sure when this is the case and what
113 // should be done if it happens
116 source_map.lookup_char_pos(primary_span.lo())
119 // FIXME(#59346): Not sure when this is the case and what
120 // should be done if it happens
123 let mut annotated_files =
124 FileWithAnnotatedLines::collect_annotations(msp, &self.source_map);
126 annotated_files.binary_search_by(|x| x.file.name.cmp(&primary_lo.file.name))
128 annotated_files.swap(0, pos);
130 // owned: line source, line index, annotations
131 type Owned = (String, usize, Vec<crate::snippet::Annotation>);
132 let filename = source_map.filename_for_diagnostics(&primary_lo.file.name);
133 let origin = filename.to_string_lossy();
134 let annotated_files: Vec<Owned> = annotated_files
136 .flat_map(|annotated_file| {
137 let file = annotated_file.file;
142 (source_string(file.clone(), &line), line.line_index, line.annotations)
144 .collect::<Vec<Owned>>()
147 let snippet = Snippet {
148 title: Some(Annotation {
149 label: Some(&message),
150 id: code.as_ref().map(|c| match c {
151 DiagnosticId::Error(val) | DiagnosticId::Lint { name: val, .. } => {
155 annotation_type: annotation_type_for_level(*level),
158 opt: FormatOptions { color: true, anonymized_line_numbers: self.ui_testing },
159 slices: annotated_files
161 .map(|(source, line_index, annotations)| {
164 line_start: *line_index,
165 origin: Some(&origin),
166 // FIXME(#59346): Not really sure when `fold` should be true or false
168 annotations: annotations
170 .map(|annotation| SourceAnnotation {
171 range: (annotation.start_col, annotation.end_col),
172 label: annotation.label.as_deref().unwrap_or_default(),
173 annotation_type: annotation_type_for_level(*level),
180 // FIXME(#59346): Figure out if we can _always_ print to stderr or not.
181 // `emitter.rs` has the `Destination` enum that lists various possible output
183 eprintln!("{}", DisplayList::from(snippet))
185 // FIXME(#59346): Is it ok to return None if there's no source_map?