From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:02:58 +0200 Subject: Adding upstream version 1.64.0+dfsg1. Signed-off-by: Daniel Baumann --- compiler/rustc_errors/src/emitter.rs | 2687 ++++++++++++++++++++++++++++++++++ 1 file changed, 2687 insertions(+) create mode 100644 compiler/rustc_errors/src/emitter.rs (limited to 'compiler/rustc_errors/src/emitter.rs') diff --git a/compiler/rustc_errors/src/emitter.rs b/compiler/rustc_errors/src/emitter.rs new file mode 100644 index 000000000..61d953cd6 --- /dev/null +++ b/compiler/rustc_errors/src/emitter.rs @@ -0,0 +1,2687 @@ +//! 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::{FileLines, SourceFile, Span}; + +use crate::snippet::{Annotation, AnnotationType, Line, MultilineAnnotation, Style, StyledString}; +use crate::styled_buffer::StyledBuffer; +use crate::{ + CodeSuggestion, Diagnostic, DiagnosticArg, DiagnosticId, DiagnosticMessage, FluentBundle, + Handler, LazyFallbackBundle, Level, MultiSpan, SubDiagnostic, SubstitutionHighlight, + SuggestionStyle, +}; + +use rustc_lint_defs::pluralize; + +use rustc_data_structures::fx::FxHashMap; +use rustc_data_structures::sync::Lrc; +use rustc_error_messages::FluentArgs; +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, + source_map: Option>, + bundle: Option>, + fallback_bundle: LazyFallbackBundle, + teach: bool, + diagnostic_width: Option, + macro_backtrace: bool, + ) -> EmitterWriter { + let (short, color_config) = self.unzip(); + let color = color_config.suggests_using_colors(); + EmitterWriter::new( + dst, + source_map, + bundle, + fallback_bundle, + short, + teach, + color, + diagnostic_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) {} + + fn emit_future_breakage_report(&mut self, _diags: Vec) {} + + /// Emit list of unused externs + fn emit_unused_externs( + &mut self, + _lint_level: rustc_lint_defs::Level, + _unused_externs: &[&str], + ) { + } + + /// Checks if should show explanations about "rustc --explain" + fn should_show_explain(&self) -> bool { + true + } + + /// Checks if we can use colors in the current output stream. + fn supports_color(&self) -> bool { + false + } + + fn source_map(&self) -> Option<&Lrc>; + + /// Return `FluentBundle` with localized diagnostics for the locale requested by the user. If no + /// language was requested by the user then this will be `None` and `fallback_fluent_bundle` + /// should be used. + fn fluent_bundle(&self) -> Option<&Lrc>; + + /// Return `FluentBundle` with localized diagnostics for the default locale of the compiler. + /// Used when the user has not requested a specific language or when a localized diagnostic is + /// unavailable for the requested locale. + fn fallback_fluent_bundle(&self) -> &FluentBundle; + + /// Convert diagnostic arguments (a rustc internal type that exists to implement + /// `Encodable`/`Decodable`) into `FluentArgs` which is necessary to perform translation. + /// + /// Typically performed once for each diagnostic at the start of `emit_diagnostic` and then + /// passed around as a reference thereafter. + fn to_fluent_args<'arg>(&self, args: &[DiagnosticArg<'arg>]) -> FluentArgs<'arg> { + FromIterator::from_iter(args.to_vec().drain(..)) + } + + /// Convert `DiagnosticMessage`s to a string, performing translation if necessary. + fn translate_messages( + &self, + messages: &[(DiagnosticMessage, Style)], + args: &FluentArgs<'_>, + ) -> Cow<'_, str> { + Cow::Owned( + messages.iter().map(|(m, _)| self.translate_message(m, args)).collect::(), + ) + } + + /// Convert a `DiagnosticMessage` to a string, performing translation if necessary. + fn translate_message<'a>( + &'a self, + message: &'a DiagnosticMessage, + args: &'a FluentArgs<'_>, + ) -> Cow<'_, str> { + trace!(?message, ?args); + let (identifier, attr) = match message { + DiagnosticMessage::Str(msg) => return Cow::Borrowed(&msg), + DiagnosticMessage::FluentIdentifier(identifier, attr) => (identifier, attr), + }; + + let bundle = match self.fluent_bundle() { + Some(bundle) if bundle.has_message(&identifier) => bundle, + _ => self.fallback_fluent_bundle(), + }; + + let message = bundle.get_message(&identifier).expect("missing diagnostic in fluent bundle"); + let value = match attr { + Some(attr) => { + if let Some(attr) = message.get_attribute(attr) { + attr.value() + } else { + panic!("missing attribute `{attr}` in fluent message `{identifier}`") + } + } + None => { + if let Some(value) = message.value() { + value + } else { + panic!("missing value in fluent message `{identifier}`") + } + } + }; + + let mut err = vec![]; + let translated = bundle.format_pattern(value, Some(&args), &mut err); + trace!(?translated, ?err); + debug_assert!( + err.is_empty(), + "identifier: {:?}, args: {:?}, errors: {:?}", + identifier, + args, + err + ); + translated + } + + /// Formats the substitutions of the primary_span + /// + /// There 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, + fluent_args: &FluentArgs<'_>, + ) -> (MultiSpan, &'a [CodeSuggestion]) { + let mut primary_span = diag.span.clone(); + let suggestions = diag.suggestions.as_ref().map_or(&[][..], |suggestions| &suggestions[..]); + if let Some((sugg, rest)) = suggestions.split_first() { + let msg = self.translate_message(&sugg.msg, fluent_args); + 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 + 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: {}", &msg) + } else { + // Show the default suggestion text with the substitution + format!( + "help: {}{}: `{}`", + &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, suggestions) + } + } else { + (primary_span, suggestions) + } + } + + fn fix_multispans_in_extern_macros_and_render_macro_backtrace( + &self, + source_map: &Option>, + span: &mut MultiSpan, + children: &mut Vec, + 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: Vec<_> = iter::once(&*span) + .chain(children.iter().map(|child| &child.span)) + .flat_map(|span| span.primary_spans()) + .flat_map(|sp| sp.macro_backtrace()) + .filter_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::Inlined | ExpnKind::Desugaring(..) | ExpnKind::AstPass(..) => None, + + ExpnKind::Macro(macro_kind, name) => Some((macro_kind, name)), + } + }) + .collect(); + + 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, name)) = has_macro_spans.first() { + // Mark the actual macro this originates from + let and_then = if let Some((macro_kind, last_name)) = has_macro_spans.last() + && last_name != name + { + let descr = macro_kind.descr(); + format!( + " which comes from the expansion of the {descr} `{last_name}`", + ) + } else { + "".to_string() + }; + + let descr = macro_kind.descr(); + let msg = format!( + "this {level} originates in the {descr} `{name}`{and_then} \ + (in Nightly builds, run with -Z macro-backtrace for more info)", + ); + + children.push(SubDiagnostic { + level: Level::Note, + message: vec![(DiagnosticMessage::Str(msg), Style::NoStyle)], + span: MultiSpan::new(), + render_span: None, + }); + } + } + } + + fn render_multispans_macro_backtrace( + &self, + span: &mut MultiSpan, + children: &mut Vec, + 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 && !matches!(trace.kind, ExpnKind::Inlined) { + 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 || always_backtrace { + let msg: Cow<'static, _> = match trace.kind { + ExpnKind::Macro(MacroKind::Attr, _) => { + "this procedural macro expansion".into() + } + ExpnKind::Macro(MacroKind::Derive, _) => { + "this derive macro expansion".into() + } + ExpnKind::Macro(MacroKind::Bang, _) => "this macro invocation".into(), + ExpnKind::Inlined => "this inlined function call".into(), + ExpnKind::Root => "the crate root".into(), + ExpnKind::AstPass(kind) => kind.descr().into(), + ExpnKind::Desugaring(kind) => { + format!("this {} desugaring", kind.descr()).into() + } + }; + new_labels.push(( + trace.call_site, + format!( + "in {}{}", + msg, + 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>, + span: &mut MultiSpan, + children: &mut Vec, + ) { + let Some(source_map) = source_map else { return }; + debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children); + self.fix_multispan_in_extern_macros(source_map, span); + for child in children.iter_mut() { + self.fix_multispan_in_extern_macros(source_map, &mut child.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: &Lrc, span: &mut MultiSpan) { + // 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() && source_map.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> { + self.sm.as_ref() + } + + fn fluent_bundle(&self) -> Option<&Lrc> { + self.fluent_bundle.as_ref() + } + + fn fallback_fluent_bundle(&self) -> &FluentBundle { + &**self.fallback_bundle + } + + fn emit_diagnostic(&mut self, diag: &Diagnostic) { + let fluent_args = self.to_fluent_args(diag.args()); + + let mut children = diag.children.clone(); + let (mut primary_span, suggestions) = self.primary_span_formatted(&diag, &fluent_args); + 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.message, + &fluent_args, + &diag.code, + &primary_span, + &children, + &suggestions, + ); + } + + fn should_show_explain(&self) -> bool { + !self.short_message + } + + fn supports_color(&self) -> bool { + self.dst.supports_color() + } +} + +/// An emitter that does nothing when emitting a non-fatal diagnostic. +/// Fatal diagnostics are forwarded to `fatal_handler` to avoid silent +/// failures of rustc, as witnessed e.g. in issue #89358. +pub struct SilentEmitter { + pub fatal_handler: Handler, + pub fatal_note: Option, +} + +impl Emitter for SilentEmitter { + fn source_map(&self) -> Option<&Lrc> { + None + } + + fn fluent_bundle(&self) -> Option<&Lrc> { + None + } + + fn fallback_fluent_bundle(&self) -> &FluentBundle { + panic!("silent emitter attempted to translate message") + } + + fn emit_diagnostic(&mut self, d: &Diagnostic) { + if d.level == Level::Fatal { + let mut d = d.clone(); + if let Some(ref note) = self.fatal_note { + d.note(note); + } + self.fatal_handler.emit_diagnostic(&mut d); + } + } +} + +/// 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>, + fluent_bundle: Option>, + fallback_bundle: LazyFallbackBundle, + short_message: bool, + teach: bool, + ui_testing: bool, + diagnostic_width: Option, + + macro_backtrace: bool, +} + +#[derive(Debug)] +pub struct FileWithAnnotatedLines { + pub file: Lrc, + pub lines: Vec, + multiline_depth: usize, +} + +impl EmitterWriter { + pub fn stderr( + color_config: ColorConfig, + source_map: Option>, + fluent_bundle: Option>, + fallback_bundle: LazyFallbackBundle, + short_message: bool, + teach: bool, + diagnostic_width: Option, + macro_backtrace: bool, + ) -> EmitterWriter { + let dst = Destination::from_stderr(color_config); + EmitterWriter { + dst, + sm: source_map, + fluent_bundle, + fallback_bundle, + short_message, + teach, + ui_testing: false, + diagnostic_width, + macro_backtrace, + } + } + + pub fn new( + dst: Box, + source_map: Option>, + fluent_bundle: Option>, + fallback_bundle: LazyFallbackBundle, + short_message: bool, + teach: bool, + colored: bool, + diagnostic_width: Option, + macro_backtrace: bool, + ) -> EmitterWriter { + EmitterWriter { + dst: Raw(dst, colored), + sm: source_map, + fluent_bundle, + fallback_bundle, + short_message, + teach, + ui_testing: false, + diagnostic_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) -> Cow<'static, str> { + if self.ui_testing { + Cow::Borrowed(ANONYMIZED_LINE_NUM) + } else { + Cow::Owned(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, + ) { + // Tabs are assumed to have been replaced by spaces in calling code. + debug_assert!(!source_string.contains('\t')); + 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_no_space(buffer, line_offset, width_offset - 2); + } + + fn render_source_line( + &self, + buffer: &mut StyledBuffer, + file: Lrc, + 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) => normalize_whitespace(&*s), + None => return Vec::new(), + }; + + let line_offset = buffer.num_lines(); + + // Left trim + let left = margin.left(source_string.len()); + + // 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 + // + // + 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 horizontal 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); + } + + // 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).saturating_sub(left), + style, + ); + } + _ if self.teach => { + buffer.set_style_range( + line_offset, + (code_offset + annotation.start_col).saturating_sub(left), + (code_offset + annotation.end_col).saturating_sub(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::>() + } + + fn get_multispan_max_line_num(&mut self, msp: &MultiSpan) -> usize { + let Some(ref sm) = self.sm else { + return 0; + }; + + let will_be_emitted = |span: Span| { + !span.is_dummy() && { + let file = sm.lookup_source_file(span.hi()); + sm.ensure_source_file_source_present(file) + } + }; + + let mut max = 0; + for primary_span in msp.primary_spans() { + if will_be_emitted(*primary_span) { + 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 will_be_emitted(span_label.span) { + 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: &[(DiagnosticMessage, Style)], + args: &FluentArgs<'_>, + padding: usize, + label: &str, + override_style: Option