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Diffstat (limited to 'compiler/rustc_errors/src/emitter.rs')
| -rw-r--r-- | compiler/rustc_errors/src/emitter.rs | 2177 |
1 files changed, 2177 insertions, 0 deletions
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 +} |