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rust/compiler/rustc_errors/src/emitter.rs
Nicholas Nethercote 453fface11 Add some comments to Emitter. 
There are three functions only used for the JSON format.
2024-01-05 10:49:35 +11:00

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//! 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 rustc_span::source_map::SourceMap;
use rustc_span::{FileLines, FileName, SourceFile, Span};
use crate::snippet::{
Annotation, AnnotationColumn, AnnotationType, Line, MultilineAnnotation, Style, StyledString,
};
use crate::styled_buffer::StyledBuffer;
use crate::translation::{to_fluent_args, Translate};
use crate::{
diagnostic::DiagnosticLocation, CodeSuggestion, DiagCtxt, Diagnostic, DiagnosticId,
DiagnosticMessage, FluentBundle, LazyFallbackBundle, Level, MultiSpan, SubDiagnostic,
SubstitutionHighlight, SuggestionStyle, TerminalUrl,
};
use rustc_lint_defs::pluralize;
use derive_setters::Setters;
use rustc_data_structures::fx::{FxHashMap, FxIndexMap, FxIndexSet};
use rustc_data_structures::sync::{DynSend, IntoDynSyncSend, Lrc};
use rustc_error_messages::{FluentArgs, SpanLabel};
use rustc_span::hygiene::{ExpnKind, MacroKind};
use std::borrow::Cow;
use std::cmp::{max, min, Reverse};
use std::error::Report;
use std::io::prelude::*;
use std::io::{self, IsTerminal};
use std::iter;
use std::path::Path;
use termcolor::{Ansi, Buffer, BufferWriter, ColorChoice, ColorSpec, StandardStream};
use termcolor::{Color, WriteColor};
/// 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,
mut dst: Box<dyn WriteColor + Send>,
fallback_bundle: LazyFallbackBundle,
) -> HumanEmitter {
let (short, color_config) = self.unzip();
let color = color_config.suggests_using_colors();
if !dst.supports_color() && color {
dst = Box::new(Ansi::new(dst));
}
HumanEmitter::new(dst, fallback_bundle).short_message(short)
}
}
#[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";
pub type DynEmitter = dyn Emitter + DynSend;
/// Emitter trait for emitting errors.
pub trait Emitter: Translate {
/// Emit a structured diagnostic.
fn emit_diagnostic(&mut self, diag: &Diagnostic);
/// Emit a notification that an artifact has been output.
/// Currently only supported for the JSON format.
fn emit_artifact_notification(&mut self, _path: &Path, _artifact_type: &str) {}
/// Emit a report about future breakage.
/// Currently only supported for the JSON format.
fn emit_future_breakage_report(&mut self, _diags: Vec<Diagnostic>) {}
/// Emit list of unused externs.
/// Currently only supported for the JSON format.
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<SourceMap>>;
/// 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_deref().unwrap_or(&[]);
if let Some((sugg, rest)) = suggestions.split_first() {
let msg = self.translate_message(&sugg.msg, fluent_args).map_err(Report::new).unwrap();
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().is_some_and(|sm| is_case_difference(
sm,
substitution,
sugg.substitutions[0].parts[0].span,
)) {
" (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,
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: 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::Desugaring(..) | ExpnKind::AstPass(..) => None,
ExpnKind::Macro(macro_kind, name) => Some((macro_kind, name)),
}
})
.collect();
if !backtrace {
self.fix_multispans_in_extern_macros(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,
messages: vec![(DiagnosticMessage::from(msg), Style::NoStyle)],
span: MultiSpan::new(),
});
}
}
}
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 = FxIndexSet::default();
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.insert((
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::Root => "the crate root".into(),
ExpnKind::AstPass(kind) => kind.descr().into(),
ExpnKind::Desugaring(kind) => {
format!("this {} desugaring", kind.descr()).into()
}
};
new_labels.insert((
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,
span: &mut MultiSpan,
children: &mut Vec<SubDiagnostic>,
) {
debug!("fix_multispans_in_extern_macros: before: span={:?} children={:?}", span, children);
self.fix_multispan_in_extern_macros(span);
for child in children.iter_mut() {
self.fix_multispan_in_extern_macros(&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, span: &mut MultiSpan) {
let Some(source_map) = self.source_map() else { 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() && 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 Translate for HumanEmitter {
fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
self.fluent_bundle.as_ref()
}
fn fallback_fluent_bundle(&self) -> &FluentBundle {
&self.fallback_bundle
}
}
impl Emitter for HumanEmitter {
fn source_map(&self) -> Option<&Lrc<SourceMap>> {
self.sm.as_ref()
}
fn emit_diagnostic(&mut self, diag: &Diagnostic) {
let fluent_args = 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(
&mut primary_span,
&mut children,
&diag.level,
self.macro_backtrace,
);
self.emit_messages_default(
&diag.level,
&diag.messages,
&fluent_args,
&diag.code,
&primary_span,
&children,
suggestions,
self.track_diagnostics.then_some(&diag.emitted_at),
);
}
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_dcx` to avoid silent
/// failures of rustc, as witnessed e.g. in issue #89358.
pub struct SilentEmitter {
pub fatal_dcx: DiagCtxt,
pub fatal_note: Option<String>,
}
impl Translate for SilentEmitter {
fn fluent_bundle(&self) -> Option<&Lrc<FluentBundle>> {
None
}
fn fallback_fluent_bundle(&self) -> &FluentBundle {
panic!("silent emitter attempted to translate message")
}
}
impl Emitter for SilentEmitter {
fn source_map(&self) -> Option<&Lrc<SourceMap>> {
None
}
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.clone());
}
self.fatal_dcx.emit_diagnostic(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 {
pub fn to_color_choice(self) -> ColorChoice {
match self {
ColorConfig::Always => {
if io::stderr().is_terminal() {
ColorChoice::Always
} else {
ColorChoice::AlwaysAnsi
}
}
ColorConfig::Never => ColorChoice::Never,
ColorConfig::Auto if io::stderr().is_terminal() => 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`
#[derive(Setters)]
pub struct HumanEmitter {
#[setters(skip)]
dst: IntoDynSyncSend<Destination>,
sm: Option<Lrc<SourceMap>>,
fluent_bundle: Option<Lrc<FluentBundle>>,
#[setters(skip)]
fallback_bundle: LazyFallbackBundle,
short_message: bool,
teach: bool,
ui_testing: bool,
ignored_directories_in_source_blocks: Vec<String>,
diagnostic_width: Option<usize>,
macro_backtrace: bool,
track_diagnostics: bool,
terminal_url: TerminalUrl,
}
#[derive(Debug)]
pub struct FileWithAnnotatedLines {
pub file: Lrc<SourceFile>,
pub lines: Vec<Line>,
multiline_depth: usize,
}
impl HumanEmitter {
pub fn stderr(color_config: ColorConfig, fallback_bundle: LazyFallbackBundle) -> HumanEmitter {
let dst = from_stderr(color_config);
Self::create(dst, fallback_bundle)
}
fn create(dst: Destination, fallback_bundle: LazyFallbackBundle) -> HumanEmitter {
HumanEmitter {
dst: IntoDynSyncSend(dst),
sm: None,
fluent_bundle: None,
fallback_bundle,
short_message: false,
teach: false,
ui_testing: false,
ignored_directories_in_source_blocks: Vec::new(),
diagnostic_width: None,
macro_backtrace: false,
track_diagnostics: false,
terminal_url: TerminalUrl::No,
}
}
pub fn new(
dst: Box<dyn WriteColor + Send>,
fallback_bundle: LazyFallbackBundle,
) -> HumanEmitter {
Self::create(dst, fallback_bundle)
}
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);
}
#[instrument(level = "trace", skip(self), ret)]
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) => normalize_whitespace(&s),
None => return Vec::new(),
};
trace!(?source_string);
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
let mut buffer_ops = vec![];
let mut annotations = vec![];
let mut short_start = true;
for ann in &line.annotations {
if let AnnotationType::MultilineStart(depth) = ann.annotation_type {
if source_string.chars().take(ann.start_col.display).all(|c| c.is_whitespace()) {
let style = if ann.is_primary {
Style::UnderlinePrimary
} else {
Style::UnderlineSecondary
};
annotations.push((depth, style));
buffer_ops.push((line_offset, width_offset + depth - 1, '/', style));
} else {
short_start = false;
break;
}
} else if let AnnotationType::MultilineLine(_) = ann.annotation_type {
} else {
short_start = false;
break;
}
}
if short_start {
for (y, x, c, s) in buffer_ops {
buffer.putc(y, x, c, s);
}
return annotations;
}
// 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 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.display).saturating_sub(left),
style,
);
}
_ if self.teach => {
buffer.set_style_range(
line_offset,
(code_offset + annotation.start_col.display).saturating_sub(left),
(code_offset + annotation.end_col.display).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.display).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.display + 1).saturating_sub(left))
} else {
(pos + 2, annotation.start_col.display.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.display..annotation.end_col.display {
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 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());
should_show_source_code(&self.ignored_directories_in_source_blocks, sm, &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 msgs_to_buffer(
&self,
buffer: &mut StyledBuffer,
msgs: &[(DiagnosticMessage, Style)],
args: &FluentArgs<'_>,
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 msgs = 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 (text, style) in msgs.iter() {
let text = self.translate_message(text, args).map_err(Report::new).unwrap();
let text = &normalize_whitespace(&text);
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));
}
}
}
#[instrument(level = "trace", skip(self, args), ret)]
fn emit_messages_default_inner(
&mut self,
msp: &MultiSpan,
msgs: &[(DiagnosticMessage, Style)],
args: &FluentArgs<'_>,
code: &Option<DiagnosticId>,
level: &Level,
max_line_num_len: usize,
is_secondary: bool,
emitted_at: Option<&DiagnosticLocation>,
) -> io::Result<()> {
let mut buffer = StyledBuffer::new();
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 {
buffer.append(0, level.to_str(), Style::MainHeaderMsg);
buffer.append(0, ": ", Style::NoStyle);
}
self.msgs_to_buffer(&mut buffer, msgs, args, max_line_num_len, "note", None);
} else {
let mut label_width = 0;
// The failure note level itself does not provide any useful diagnostic information
if *level != Level::FailureNote {
buffer.append(0, level.to_str(), Style::Level(*level));
label_width += level.to_str().len();
}
// only render error codes, not lint codes
if let Some(DiagnosticId::Error(ref code)) = *code {
buffer.append(0, "[", Style::Level(*level));
let code = if let TerminalUrl::Yes = self.terminal_url {
let path = "https://doc.rust-lang.org/error_codes";
format!("\x1b]8;;{path}/{code}.html\x07{code}\x1b]8;;\x07")
} else {
code.clone()
};
buffer.append(0, &code, Style::Level(*level));
buffer.append(0, "]", Style::Level(*level));
label_width += 2 + code.len();
}
let header_style = if is_secondary {
Style::HeaderMsg
} else if self.short_message {
// For short messages avoid bolding the message, as it doesn't look great (#63835).
Style::NoStyle
} else {
Style::MainHeaderMsg
};
if *level != Level::FailureNote {
buffer.append(0, ": ", header_style);
label_width += 2;
}
for (text, _) in msgs.iter() {
let text = self.translate_message(text, args).map_err(Report::new).unwrap();
// Account for newlines to align output to its label.
for (line, text) in normalize_whitespace(&text).lines().enumerate() {
buffer.append(
line,
&format!(
"{}{}",
if line == 0 { String::new() } else { " ".repeat(label_width) },
text
),
header_style,
);
}
}
}
let mut annotated_files = FileWithAnnotatedLines::collect_annotations(self, args, msp);
trace!("{annotated_files:#?}");
// Make sure our primary file comes first
let primary_span = msp.primary_span().unwrap_or_default();
let (Some(sm), false) = (self.sm.as_ref(), primary_span.is_dummy()) else {
// If we don't have span information, emit and exit
return emit_to_destination(&buffer.render(), level, &mut self.dst, self.short_message);
};
let primary_lo = sm.lookup_char_pos(primary_span.lo());
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 !should_show_source_code(
&self.ignored_directories_in_source_blocks,
sm,
&annotated_file.file,
) {
if !self.short_message {
// We'll just print an unannotated message.
for (annotation_id, line) in annotated_file.lines.iter().enumerate() {
let mut annotations = line.annotations.clone();
annotations.sort_by_key(|a| Reverse(a.start_col));
let mut line_idx = buffer.num_lines();
let labels: Vec<_> = annotations
.iter()
.filter_map(|a| Some((a.label.as_ref()?, a.is_primary)))
.filter(|(l, _)| !l.is_empty())
.collect();
if annotation_id == 0 || !labels.is_empty() {
buffer.append(
line_idx,
&format!(
"{}:{}:{}",
sm.filename_for_diagnostics(&annotated_file.file.name),
sm.doctest_offset_line(
&annotated_file.file.name,
line.line_index
),
annotations[0].start_col.file + 1,
),
Style::LineAndColumn,
);
if annotation_id == 0 {
buffer.prepend(line_idx, "--> ", Style::LineNumber);
} else {
buffer.prepend(line_idx, "::: ", Style::LineNumber);
}
for _ in 0..max_line_num_len {
buffer.prepend(line_idx, " ", Style::NoStyle);
}
line_idx += 1;
}
for (label, is_primary) in labels.into_iter() {
let style = if is_primary {
Style::LabelPrimary
} else {
Style::LabelSecondary
};
buffer.prepend(line_idx, " |", Style::LineNumber);
for _ in 0..max_line_num_len {
buffer.prepend(line_idx, " ", Style::NoStyle);
}
line_idx += 1;
buffer.append(line_idx, " = note: ", style);
for _ in 0..max_line_num_len {
buffer.prepend(line_idx, " ", Style::NoStyle);
}
buffer.append(line_idx, label, style);
line_idx += 1;
}
}
}
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!(
"{}:{}:{}",
sm.filename_for_diagnostics(&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!(
"{}:{}:{}: ",
sm.filename_for_diagnostics(&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_no_space(
&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.file + 1)
} else {
String::new()
};
format!(
"{}:{}{}",
sm.filename_for_diagnostics(&annotated_file.file.name),
sm.doctest_offset_line(&annotated_file.file.name, first_line.line_index),
col
)
} else {
format!("{}", sm.filename_for_diagnostics(&annotated_file.file.name))
};
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 = FxIndexMap::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())
.map(|c| {
match c {
// Tabs are displayed as 4 spaces
'\t' => 4,
_ => 1,
}
})
.sum();
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.display);
span_left_margin = min(span_left_margin, ann.end_col.display);
}
}
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.display);
span_right_margin = max(span_right_margin, ann.end_col.display);
// 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.display + 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.diagnostic_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.remove(&depth).is_none() {
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,
&normalize_whitespace(&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);
}
}
trace!("buffer: {:#?}", buffer.render());
}
if let Some(tracked) = emitted_at {
let track = format!("-Ztrack-diagnostics: created at {tracked}");
let len = buffer.num_lines();
buffer.append(len, &track, Style::NoStyle);
}
// 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,
span: &MultiSpan,
suggestion: &CodeSuggestion,
args: &FluentArgs<'_>,
level: &Level,
max_line_num_len: usize,
) -> io::Result<()> {
let Some(ref sm) = self.sm else {
return Ok(());
};
// Render the replacements for each suggestion
let suggestions = suggestion.splice_lines(sm);
debug!(?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
buffer.append(0, level.to_str(), Style::Level(*level));
buffer.append(0, ": ", Style::HeaderMsg);
self.msgs_to_buffer(
&mut buffer,
&[(suggestion.msg.to_owned(), Style::NoStyle)],
args,
max_line_num_len,
"suggestion",
Some(Style::HeaderMsg),
);
let mut row_num = 2;
draw_col_separator_no_space(&mut buffer, 1, max_line_num_len + 1);
let mut notice_capitalization = false;
for (complete, parts, highlights, only_capitalization) in
suggestions.iter().take(MAX_SUGGESTIONS)
{
debug!(?complete, ?parts, ?highlights);
notice_capitalization |= only_capitalization;
let has_deletion = parts.iter().any(|p| p.is_deletion(sm));
let is_multiline = complete.lines().count() > 1;
if let Some(span) = span.primary_span() {
// Compare the primary span of the diagnostic with the span of the suggestion
// being emitted. If they belong to the same file, we don't *need* to show the
// file name, saving in verbosity, but if it *isn't* we do need it, otherwise we're
// telling users to make a change but not clarifying *where*.
let loc = sm.lookup_char_pos(parts[0].span.lo());
if loc.file.name != sm.span_to_filename(span) && loc.file.name.is_real() {
let arrow = "--> ";
buffer.puts(row_num - 1, 0, arrow, Style::LineNumber);
let filename = sm.filename_for_diagnostics(&loc.file.name);
let offset = sm.doctest_offset_line(&loc.file.name, loc.line);
let message = format!("{}:{}:{}", filename, offset, loc.col.0 + 1);
if row_num == 2 {
let col = usize::max(max_line_num_len + 1, arrow.len());
buffer.puts(1, col, &message, Style::LineAndColumn);
} else {
buffer.append(row_num - 1, &message, Style::LineAndColumn);
}
for _ in 0..max_line_num_len {
buffer.prepend(row_num - 1, " ", Style::NoStyle);
}
row_num += 1;
}
}
let show_code_change = if has_deletion && !is_multiline {
DisplaySuggestion::Diff
} else if let [part] = &parts[..]
&& part.snippet.ends_with('\n')
&& part.snippet.trim() == complete.trim()
{
// We are adding a line(s) of code before code that was already there.
DisplaySuggestion::Add
} else if (parts.len() != 1 || parts[0].snippet.trim() != complete.trim())
&& !is_multiline
{
DisplaySuggestion::Underline
} else {
DisplaySuggestion::None
};
if let DisplaySuggestion::Diff = show_code_change {
row_num += 1;
}
let file_lines = sm
.span_to_lines(parts[0].span)
.expect("span_to_lines failed when emitting suggestion");
assert!(!file_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, row_num - 1, max_line_num_len + 1);
let mut lines = complete.lines();
if lines.clone().next().is_none() {
// Account for a suggestion to completely remove a line(s) with whitespace (#94192).
let line_end = sm.lookup_char_pos(parts[0].span.hi()).line;
for line in line_start..=line_end {
buffer.puts(
row_num - 1 + line - line_start,
0,
&self.maybe_anonymized(line),
Style::LineNumber,
);
buffer.puts(
row_num - 1 + line - line_start,
max_line_num_len + 1,
"- ",
Style::Removal,
);
buffer.puts(
row_num - 1 + line - line_start,
max_line_num_len + 3,
&normalize_whitespace(&file_lines.file.get_line(line - 1).unwrap()),
Style::Removal,
);
}
row_num += line_end - line_start;
}
let mut unhighlighted_lines = Vec::new();
let mut last_pos = 0;
let mut is_item_attribute = false;
for (line_pos, (line, highlight_parts)) in lines.by_ref().zip(highlights).enumerate() {
last_pos = line_pos;
debug!(%line_pos, %line, ?highlight_parts);
// Remember lines that are not highlighted to hide them if needed
if highlight_parts.is_empty() {
unhighlighted_lines.push((line_pos, line));
continue;
}
if highlight_parts.len() == 1
&& line.trim().starts_with("#[")
&& line.trim().ends_with(']')
{
is_item_attribute = true;
}
match unhighlighted_lines.len() {
0 => (),
// Since we show first line, "..." line and last line,
// There is no reason to hide if there are 3 or less lines
// (because then we just replace a line with ... which is
// not helpful)
n if n <= 3 => unhighlighted_lines.drain(..).for_each(|(p, l)| {
self.draw_code_line(
&mut buffer,
&mut row_num,
&[],
p + line_start,
l,
show_code_change,
max_line_num_len,
&file_lines,
is_multiline,
)
}),
// Print first unhighlighted line, "..." and last unhighlighted line, like so:
//
// LL | this line was highlighted
// LL | this line is just for context
// ...
// LL | this line is just for context
// LL | this line was highlighted
_ => {
let last_line = unhighlighted_lines.pop();
let first_line = unhighlighted_lines.drain(..).next();
if let Some((p, l)) = first_line {
self.draw_code_line(
&mut buffer,
&mut row_num,
&[],
p + line_start,
l,
show_code_change,
max_line_num_len,
&file_lines,
is_multiline,
)
}
buffer.puts(row_num, max_line_num_len - 1, "...", Style::LineNumber);
row_num += 1;
if let Some((p, l)) = last_line {
self.draw_code_line(
&mut buffer,
&mut row_num,
&[],
p + line_start,
l,
show_code_change,
max_line_num_len,
&file_lines,
is_multiline,
)
}
}
}
self.draw_code_line(
&mut buffer,
&mut row_num,
highlight_parts,
line_pos + line_start,
line,
show_code_change,
max_line_num_len,
&file_lines,
is_multiline,
)
}
if let DisplaySuggestion::Add = show_code_change
&& is_item_attribute
{
// The suggestion adds an entire line of code, ending on a newline, so we'll also
// print the *following* line, to provide context of what we're advising people to
// do. Otherwise you would only see contextless code that can be confused for
// already existing code, despite the colors and UI elements.
// We special case `#[derive(_)]\n` and other attribute suggestions, because those
// are the ones where context is most useful.
let file_lines = sm
.span_to_lines(parts[0].span.shrink_to_hi())
.expect("span_to_lines failed when emitting suggestion");
let line_num = sm.lookup_char_pos(parts[0].span.lo()).line;
if let Some(line) = file_lines.file.get_line(line_num - 1) {
let line = normalize_whitespace(&line);
self.draw_code_line(
&mut buffer,
&mut row_num,
&[],
line_num + last_pos + 1,
&line,
DisplaySuggestion::None,
max_line_num_len,
&file_lines,
is_multiline,
)
}
}
// 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 let DisplaySuggestion::Diff | DisplaySuggestion::Underline | DisplaySuggestion::Add =
show_code_change
{
draw_col_separator_no_space(&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;
// If this addition is _only_ whitespace, then don't trim it,
// or else we're just not rendering anything.
let is_whitespace_addition = part.snippet.trim().is_empty();
// Do not underline the leading...
let start = if is_whitespace_addition {
0
} else {
part.snippet.len().saturating_sub(part.snippet.trim_start().len())
};
// ...or trailing spaces. Account for substitutions containing unicode
// characters.
let sub_len: usize =
if is_whitespace_addition { &part.snippet } else { 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);
let padding: usize = max_line_num_len + 3;
for p in underline_start..underline_end {
if let DisplaySuggestion::Underline = show_code_change {
// If this is a replacement, underline with `^`, if this is an addition
// underline with `+`.
buffer.putc(
row_num,
(padding as isize + p) as usize,
if part.is_addition(sm) { '+' } else { '~' },
Style::Addition,
);
}
}
if let DisplaySuggestion::Diff = show_code_change {
// Colorize removal with red in diff format.
buffer.set_style_range(
row_num - 2,
(padding as isize + span_start_pos as isize) as usize,
(padding as isize + span_end_pos as isize) as usize,
Style::Removal,
true,
);
}
// 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 let DisplaySuggestion::None = show_code_change {
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(())
}
#[instrument(level = "trace", skip(self, args, code, children, suggestions))]
fn emit_messages_default(
&mut self,
level: &Level,
messages: &[(DiagnosticMessage, Style)],
args: &FluentArgs<'_>,
code: &Option<DiagnosticId>,
span: &MultiSpan,
children: &[SubDiagnostic],
suggestions: &[CodeSuggestion],
emitted_at: Option<&DiagnosticLocation>,
) {
let max_line_num_len = if self.ui_testing {
ANONYMIZED_LINE_NUM.len()
} else {
let n = self.get_max_line_num(span, children);
num_decimal_digits(n)
};
match self.emit_messages_default_inner(
span,
messages,
args,
code,
level,
max_line_num_len,
false,
emitted_at,
) {
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);
}
if let Err(e) = emit_to_destination(
&buffer.render(),
level,
&mut self.dst,
self.short_message,
) {
panic!("failed to emit error: {e}")
}
}
if !self.short_message {
for child in children {
let span = &child.span;
if let Err(err) = self.emit_messages_default_inner(
span,
&child.messages,
args,
&None,
&child.level,
max_line_num_len,
true,
None,
) {
panic!("failed to emit error: {err}");
}
}
for sugg in suggestions {
match sugg.style {
SuggestionStyle::CompletelyHidden => {
// do not display this suggestion, it is meant only for tools
}
SuggestionStyle::HideCodeAlways => {
if let Err(e) = self.emit_messages_default_inner(
&MultiSpan::new(),
&[(sugg.msg.to_owned(), Style::HeaderMsg)],
args,
&None,
&Level::Help,
max_line_num_len,
true,
None,
) {
panic!("failed to emit error: {e}");
}
}
SuggestionStyle::HideCodeInline
| SuggestionStyle::ShowCode
| SuggestionStyle::ShowAlways => {
if let Err(e) = self.emit_suggestion_default(
span,
sugg,
args,
&Level::Help,
max_line_num_len,
) {
panic!("failed to emit error: {e}");
}
}
}
}
}
}
Err(e) => panic!("failed to emit error: {e}"),
}
match writeln!(self.dst) {
Err(e) => panic!("failed to emit error: {e}"),
_ => {
if let Err(e) = self.dst.flush() {
panic!("failed to emit error: {e}")
}
}
}
}
fn draw_code_line(
&self,
buffer: &mut StyledBuffer,
row_num: &mut usize,
highlight_parts: &[SubstitutionHighlight],
line_num: usize,
line_to_add: &str,
show_code_change: DisplaySuggestion,
max_line_num_len: usize,
file_lines: &FileLines,
is_multiline: bool,
) {
if let DisplaySuggestion::Diff = show_code_change {
// We need to print more than one line if the span we need to remove is multiline.
// For more info: https://github.com/rust-lang/rust/issues/92741
let lines_to_remove = file_lines.lines.iter().take(file_lines.lines.len() - 1);
for (index, line_to_remove) in lines_to_remove.enumerate() {
buffer.puts(
*row_num - 1,
0,
&self.maybe_anonymized(line_num + index),
Style::LineNumber,
);
buffer.puts(*row_num - 1, max_line_num_len + 1, "- ", Style::Removal);
let line = normalize_whitespace(
&file_lines.file.get_line(line_to_remove.line_index).unwrap(),
);
buffer.puts(*row_num - 1, max_line_num_len + 3, &line, Style::NoStyle);
*row_num += 1;
}
// If the last line is exactly equal to the line we need to add, we can skip both of them.
// This allows us to avoid output like the following:
// 2 - &
// 2 + if true { true } else { false }
// 3 - if true { true } else { false }
// If those lines aren't equal, we print their diff
let last_line_index = file_lines.lines[file_lines.lines.len() - 1].line_index;
let last_line = &file_lines.file.get_line(last_line_index).unwrap();
if last_line != line_to_add {
buffer.puts(
*row_num - 1,
0,
&self.maybe_anonymized(line_num + file_lines.lines.len() - 1),
Style::LineNumber,
);
buffer.puts(*row_num - 1, max_line_num_len + 1, "- ", Style::Removal);
buffer.puts(
*row_num - 1,
max_line_num_len + 3,
&normalize_whitespace(last_line),
Style::NoStyle,
);
buffer.puts(*row_num, 0, &self.maybe_anonymized(line_num), Style::LineNumber);
buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
buffer.append(*row_num, &normalize_whitespace(line_to_add), Style::NoStyle);
} else {
*row_num -= 2;
}
} else if is_multiline {
buffer.puts(*row_num, 0, &self.maybe_anonymized(line_num), Style::LineNumber);
match &highlight_parts {
[SubstitutionHighlight { start: 0, end }] if *end == line_to_add.len() => {
buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
}
[] => {
draw_col_separator(buffer, *row_num, max_line_num_len + 1);
}
_ => {
buffer.puts(*row_num, max_line_num_len + 1, "~ ", Style::Addition);
}
}
buffer.append(*row_num, &normalize_whitespace(line_to_add), Style::NoStyle);
} else if let DisplaySuggestion::Add = show_code_change {
buffer.puts(*row_num, 0, &self.maybe_anonymized(line_num), Style::LineNumber);
buffer.puts(*row_num, max_line_num_len + 1, "+ ", Style::Addition);
buffer.append(*row_num, &normalize_whitespace(line_to_add), Style::NoStyle);
} else {
buffer.puts(*row_num, 0, &self.maybe_anonymized(line_num), Style::LineNumber);
draw_col_separator(buffer, *row_num, max_line_num_len + 1);
buffer.append(*row_num, &normalize_whitespace(line_to_add), Style::NoStyle);
}
// Colorize addition/replacements with green.
for &SubstitutionHighlight { start, end } in highlight_parts {
// This is a no-op for empty ranges
if start != end {
// Account for tabs when highlighting (#87972).
let tabs: usize = line_to_add
.chars()
.take(start)
.map(|ch| match ch {
'\t' => 3,
_ => 0,
})
.sum();
buffer.set_style_range(
*row_num,
max_line_num_len + 3 + start + tabs,
max_line_num_len + 3 + end + tabs,
Style::Addition,
true,
);
}
}
*row_num += 1;
}
}
#[derive(Clone, Copy, Debug)]
enum DisplaySuggestion {
Underline,
Diff,
None,
Add,
}
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(
emitter: &dyn Emitter,
args: &FluentArgs<'_>,
msp: &MultiSpan,
) -> 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(sm) = emitter.source_map() {
for SpanLabel { span, is_primary, label } in msp.span_labels() {
// If we don't have a useful span, pick the primary span if that exists.
// Worst case we'll just print an error at the top of the main file.
let span = match (span.is_dummy(), msp.primary_span()) {
(_, None) | (false, _) => span,
(true, Some(span)) => span,
};
let lo = sm.lookup_char_pos(span.lo());
let mut hi = sm.lookup_char_pos(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;
}
let label = label.as_ref().map(|m| {
normalize_whitespace(
&emitter.translate_message(m, args).map_err(Report::new).unwrap(),
)
});
if lo.line != hi.line {
let ml = MultilineAnnotation {
depth: 1,
line_start: lo.line,
line_end: hi.line,
start_col: AnnotationColumn::from_loc(&lo),
end_col: AnnotationColumn::from_loc(&hi),
is_primary,
label,
overlaps_exactly: false,
};
multiline_annotations.push((lo.file, ml));
} else {
let ann = Annotation {
start_col: AnnotationColumn::from_loc(&lo),
end_col: AnnotationColumn::from_loc(&hi),
is_primary,
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(|(_, ml)| (ml.line_start, usize::MAX - 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 (_, ann) in &multiline_annotations {
max_depth = max(max_depth, ann.depth);
}
// Change order of multispan depth to minimize the number of overlaps in the ASCII art.
for (_, a) in multiline_annotations.iter_mut() {
a.depth = max_depth - a.depth + 1;
}
for (file, ann) in multiline_annotations {
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
}
}
// instead of taking the String length or dividing by 10 while > 0, we multiply a limit by 10 until
// we're higher. If the loop isn't exited by the `return`, the last multiplication will wrap, which
// is OK, because while we cannot fit a higher power of 10 in a usize, the loop will end anyway.
// This is also why we need the max number of decimal digits within a `usize`.
fn num_decimal_digits(num: usize) -> usize {
#[cfg(target_pointer_width = "64")]
const MAX_DIGITS: usize = 20;
#[cfg(target_pointer_width = "32")]
const MAX_DIGITS: usize = 10;
#[cfg(target_pointer_width = "16")]
const MAX_DIGITS: usize = 5;
let mut lim = 10;
for num_digits in 1..MAX_DIGITS {
if num < lim {
return num_digits;
}
lim = lim.wrapping_mul(10);
}
MAX_DIGITS
}
// We replace some characters so the CLI output is always consistent and underlines aligned.
const OUTPUT_REPLACEMENTS: &[(char, &str)] = &[
('\t', " "), // We do our own tab replacement
('\u{200D}', ""), // Replace ZWJ with nothing for consistent terminal output of grapheme clusters.
('\u{202A}', ""), // The following unicode text flow control characters are inconsistently
('\u{202B}', ""), // supported across CLIs and can cause confusion due to the bytes on disk
('\u{202D}', ""), // not corresponding to the visible source code, so we replace them always.
('\u{202E}', ""),
('\u{2066}', ""),
('\u{2067}', ""),
('\u{2068}', ""),
('\u{202C}', ""),
('\u{2069}', ""),
];
fn normalize_whitespace(str: &str) -> String {
let mut s = str.to_string();
for (c, replacement) in OUTPUT_REPLACEMENTS {
s = s.replace(*c, replacement);
}
s
}
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.display,
a1.end_col.display + padding,
a2.start_col.display,
a2.end_col.display,
false,
)
}
fn emit_to_destination(
rendered_buffer: &[Vec<StyledString>],
lvl: &Level,
dst: &mut Destination,
short_message: bool,
) -> io::Result<()> {
use crate::lock;
// 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 {
let style = part.style.color_spec(*lvl);
dst.set_color(&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 type Destination = Box<(dyn WriteColor + Send)>;
struct Buffy {
buffer_writer: BufferWriter,
buffer: Buffer,
}
impl Write for Buffy {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
self.buffer.write(buf)
}
fn flush(&mut self) -> io::Result<()> {
self.buffer_writer.print(&self.buffer)?;
self.buffer.clear();
Ok(())
}
}
impl Drop for Buffy {
fn drop(&mut self) {
if !self.buffer.is_empty() {
self.flush().unwrap();
panic!("buffers need to be flushed in order to print their contents");
}
}
}
impl WriteColor for Buffy {
fn supports_color(&self) -> bool {
self.buffer.supports_color()
}
fn set_color(&mut self, spec: &ColorSpec) -> io::Result<()> {
self.buffer.set_color(spec)
}
fn reset(&mut self) -> io::Result<()> {
self.buffer.reset()
}
}
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) {
Box::new(StandardStream::stderr(choice))
} else {
let buffer_writer = BufferWriter::stderr(choice);
let buffer = buffer_writer.buffer();
Box::new(Buffy { buffer_writer, buffer })
}
}
/// On Windows, BRIGHT_BLUE is hard to read on black. Use cyan instead.
///
/// See #36178.
const BRIGHT_BLUE: Color = if cfg!(windows) { Color::Cyan } else { Color::Blue };
impl Style {
fn color_spec(&self, lvl: Level) -> ColorSpec {
let mut spec = ColorSpec::new();
match self {
Style::Addition => {
spec.set_fg(Some(Color::Green)).set_intense(true);
}
Style::Removal => {
spec.set_fg(Some(Color::Red)).set_intense(true);
}
Style::LineAndColumn => {}
Style::LineNumber => {
spec.set_bold(true);
spec.set_intense(true);
spec.set_fg(Some(BRIGHT_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);
spec.set_fg(Some(BRIGHT_BLUE));
}
Style::HeaderMsg | Style::NoStyle => {}
Style::Level(lvl) => {
spec = lvl.color();
spec.set_bold(true);
}
Style::Highlight => {
spec.set_bold(true).set_fg(Some(Color::Magenta));
}
}
spec
}
}
/// 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!(error = ?e, "Invalid span {:?}", sp);
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 = iter::zip(found.chars(), 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
}
pub(crate) fn should_show_source_code(
ignored_directories: &[String],
sm: &SourceMap,
file: &SourceFile,
) -> bool {
if !sm.ensure_source_file_source_present(file) {
return false;
}
let FileName::Real(name) = &file.name else { return true };
name.local_path()
.map(|path| ignored_directories.iter().all(|dir| !path.starts_with(dir)))
.unwrap_or(true)
}
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