rust/compiler/rustc_errors/src/lib.rs
2020-10-30 20:02:14 -04:00

1108 lines
38 KiB
Rust

//! Diagnostics creation and emission for `rustc`.
//!
//! This module contains the code for creating and emitting diagnostics.
#![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
#![feature(crate_visibility_modifier)]
#![feature(backtrace)]
#![feature(nll)]
#[macro_use]
extern crate rustc_macros;
pub use emitter::ColorConfig;
use tracing::debug;
use Level::*;
use emitter::{is_case_difference, Emitter, EmitterWriter};
use registry::Registry;
use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
use rustc_data_structures::stable_hasher::StableHasher;
use rustc_data_structures::sync::{self, Lock, Lrc};
use rustc_data_structures::AtomicRef;
use rustc_lint_defs::FutureBreakage;
pub use rustc_lint_defs::{pluralize, Applicability};
use rustc_span::source_map::SourceMap;
use rustc_span::{Loc, MultiSpan, Span};
use std::borrow::Cow;
use std::panic;
use std::path::Path;
use std::{error, fmt};
use termcolor::{Color, ColorSpec};
pub mod annotate_snippet_emitter_writer;
mod diagnostic;
mod diagnostic_builder;
pub mod emitter;
pub mod json;
mod lock;
pub mod registry;
mod snippet;
mod styled_buffer;
pub use snippet::Style;
pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
// `PResult` is used a lot. Make sure it doesn't unintentionally get bigger.
// (See also the comment on `DiagnosticBuilderInner`.)
#[cfg(target_arch = "x86_64")]
rustc_data_structures::static_assert_size!(PResult<'_, bool>, 16);
#[derive(Debug, PartialEq, Eq, Clone, Copy, Hash, Encodable, Decodable)]
pub enum SuggestionStyle {
/// Hide the suggested code when displaying this suggestion inline.
HideCodeInline,
/// Always hide the suggested code but display the message.
HideCodeAlways,
/// Do not display this suggestion in the cli output, it is only meant for tools.
CompletelyHidden,
/// Always show the suggested code.
/// This will *not* show the code if the suggestion is inline *and* the suggested code is
/// empty.
ShowCode,
/// Always show the suggested code independently.
ShowAlways,
}
impl SuggestionStyle {
fn hide_inline(&self) -> bool {
!matches!(*self, SuggestionStyle::ShowCode)
}
}
#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
pub struct CodeSuggestion {
/// Each substitute can have multiple variants due to multiple
/// applicable suggestions
///
/// `foo.bar` might be replaced with `a.b` or `x.y` by replacing
/// `foo` and `bar` on their own:
///
/// ```
/// vec![
/// Substitution { parts: vec![(0..3, "a"), (4..7, "b")] },
/// Substitution { parts: vec![(0..3, "x"), (4..7, "y")] },
/// ]
/// ```
///
/// or by replacing the entire span:
///
/// ```
/// vec![
/// Substitution { parts: vec![(0..7, "a.b")] },
/// Substitution { parts: vec![(0..7, "x.y")] },
/// ]
/// ```
pub substitutions: Vec<Substitution>,
pub msg: String,
/// Visual representation of this suggestion.
pub style: SuggestionStyle,
/// Whether or not the suggestion is approximate
///
/// Sometimes we may show suggestions with placeholders,
/// which are useful for users but not useful for
/// tools like rustfix
pub applicability: Applicability,
}
#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
/// See the docs on `CodeSuggestion::substitutions`
pub struct Substitution {
pub parts: Vec<SubstitutionPart>,
}
#[derive(Clone, Debug, PartialEq, Hash, Encodable, Decodable)]
pub struct SubstitutionPart {
pub span: Span,
pub snippet: String,
}
impl CodeSuggestion {
/// Returns the assembled code suggestions, whether they should be shown with an underline
/// and whether the substitution only differs in capitalization.
pub fn splice_lines(&self, sm: &SourceMap) -> Vec<(String, Vec<SubstitutionPart>, bool)> {
use rustc_span::{CharPos, Pos};
fn push_trailing(
buf: &mut String,
line_opt: Option<&Cow<'_, str>>,
lo: &Loc,
hi_opt: Option<&Loc>,
) {
let (lo, hi_opt) = (lo.col.to_usize(), hi_opt.map(|hi| hi.col.to_usize()));
if let Some(line) = line_opt {
if let Some(lo) = line.char_indices().map(|(i, _)| i).nth(lo) {
let hi_opt = hi_opt.and_then(|hi| line.char_indices().map(|(i, _)| i).nth(hi));
match hi_opt {
Some(hi) if hi > lo => buf.push_str(&line[lo..hi]),
Some(_) => (),
None => buf.push_str(&line[lo..]),
}
}
if hi_opt.is_none() {
buf.push('\n');
}
}
}
assert!(!self.substitutions.is_empty());
self.substitutions
.iter()
.filter(|subst| {
// Suggestions coming from macros can have malformed spans. This is a heavy
// handed approach to avoid ICEs by ignoring the suggestion outright.
let invalid = subst.parts.iter().any(|item| sm.is_valid_span(item.span).is_err());
if invalid {
debug!("splice_lines: suggestion contains an invalid span: {:?}", subst);
}
!invalid
})
.cloned()
.filter_map(|mut substitution| {
// Assumption: all spans are in the same file, and all spans
// are disjoint. Sort in ascending order.
substitution.parts.sort_by_key(|part| part.span.lo());
// Find the bounding span.
let lo = substitution.parts.iter().map(|part| part.span.lo()).min()?;
let hi = substitution.parts.iter().map(|part| part.span.hi()).max()?;
let bounding_span = Span::with_root_ctxt(lo, hi);
// The different spans might belong to different contexts, if so ignore suggestion.
let lines = sm.span_to_lines(bounding_span).ok()?;
assert!(!lines.lines.is_empty() || bounding_span.is_dummy());
// We can't splice anything if the source is unavailable.
if !sm.ensure_source_file_source_present(lines.file.clone()) {
return None;
}
// To build up the result, we do this for each span:
// - push the line segment trailing the previous span
// (at the beginning a "phantom" span pointing at the start of the line)
// - push lines between the previous and current span (if any)
// - if the previous and current span are not on the same line
// push the line segment leading up to the current span
// - splice in the span substitution
//
// Finally push the trailing line segment of the last span
let sf = &lines.file;
let mut prev_hi = sm.lookup_char_pos(bounding_span.lo());
prev_hi.col = CharPos::from_usize(0);
let mut prev_line =
lines.lines.get(0).and_then(|line0| sf.get_line(line0.line_index));
let mut buf = String::new();
for part in &substitution.parts {
let cur_lo = sm.lookup_char_pos(part.span.lo());
if prev_hi.line == cur_lo.line {
push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo));
} else {
push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
// push lines between the previous and current span (if any)
for idx in prev_hi.line..(cur_lo.line - 1) {
if let Some(line) = sf.get_line(idx) {
buf.push_str(line.as_ref());
buf.push('\n');
}
}
if let Some(cur_line) = sf.get_line(cur_lo.line - 1) {
let end = match cur_line.char_indices().nth(cur_lo.col.to_usize()) {
Some((i, _)) => i,
None => cur_line.len(),
};
buf.push_str(&cur_line[..end]);
}
}
buf.push_str(&part.snippet);
prev_hi = sm.lookup_char_pos(part.span.hi());
prev_line = sf.get_line(prev_hi.line - 1);
}
let only_capitalization = is_case_difference(sm, &buf, bounding_span);
// if the replacement already ends with a newline, don't print the next line
if !buf.ends_with('\n') {
push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None);
}
// remove trailing newlines
while buf.ends_with('\n') {
buf.pop();
}
Some((buf, substitution.parts, only_capitalization))
})
.collect()
}
}
pub use rustc_span::fatal_error::{FatalError, FatalErrorMarker};
/// Signifies that the compiler died with an explicit call to `.bug`
/// or `.span_bug` rather than a failed assertion, etc.
#[derive(Copy, Clone, Debug)]
pub struct ExplicitBug;
impl fmt::Display for ExplicitBug {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "parser internal bug")
}
}
impl error::Error for ExplicitBug {}
pub use diagnostic::{Diagnostic, DiagnosticId, DiagnosticStyledString, SubDiagnostic};
pub use diagnostic_builder::DiagnosticBuilder;
/// A handler deals with errors and other compiler output.
/// Certain errors (fatal, bug, unimpl) may cause immediate exit,
/// others log errors for later reporting.
pub struct Handler {
flags: HandlerFlags,
inner: Lock<HandlerInner>,
}
/// This inner struct exists to keep it all behind a single lock;
/// this is done to prevent possible deadlocks in a multi-threaded compiler,
/// as well as inconsistent state observation.
struct HandlerInner {
flags: HandlerFlags,
/// The number of errors that have been emitted, including duplicates.
///
/// This is not necessarily the count that's reported to the user once
/// compilation ends.
err_count: usize,
warn_count: usize,
deduplicated_err_count: usize,
emitter: Box<dyn Emitter + sync::Send>,
delayed_span_bugs: Vec<Diagnostic>,
delayed_good_path_bugs: Vec<Diagnostic>,
/// This set contains the `DiagnosticId` of all emitted diagnostics to avoid
/// emitting the same diagnostic with extended help (`--teach`) twice, which
/// would be uneccessary repetition.
taught_diagnostics: FxHashSet<DiagnosticId>,
/// Used to suggest rustc --explain <error code>
emitted_diagnostic_codes: FxHashSet<DiagnosticId>,
/// This set contains a hash of every diagnostic that has been emitted by
/// this handler. These hashes is used to avoid emitting the same error
/// twice.
emitted_diagnostics: FxHashSet<u128>,
/// Stashed diagnostics emitted in one stage of the compiler that may be
/// stolen by other stages (e.g. to improve them and add more information).
/// The stashed diagnostics count towards the total error count.
/// When `.abort_if_errors()` is called, these are also emitted.
stashed_diagnostics: FxIndexMap<(Span, StashKey), Diagnostic>,
/// The warning count, used for a recap upon finishing
deduplicated_warn_count: usize,
future_breakage_diagnostics: Vec<Diagnostic>,
}
/// A key denoting where from a diagnostic was stashed.
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
pub enum StashKey {
ItemNoType,
}
fn default_track_diagnostic(_: &Diagnostic) {}
pub static TRACK_DIAGNOSTICS: AtomicRef<fn(&Diagnostic)> =
AtomicRef::new(&(default_track_diagnostic as fn(&_)));
#[derive(Copy, Clone, Default)]
pub struct HandlerFlags {
/// If false, warning-level lints are suppressed.
/// (rustc: see `--allow warnings` and `--cap-lints`)
pub can_emit_warnings: bool,
/// If true, error-level diagnostics are upgraded to bug-level.
/// (rustc: see `-Z treat-err-as-bug`)
pub treat_err_as_bug: Option<usize>,
/// If true, immediately emit diagnostics that would otherwise be buffered.
/// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
pub dont_buffer_diagnostics: bool,
/// If true, immediately print bugs registered with `delay_span_bug`.
/// (rustc: see `-Z report-delayed-bugs`)
pub report_delayed_bugs: bool,
/// Show macro backtraces.
/// (rustc: see `-Z macro-backtrace`)
pub macro_backtrace: bool,
/// If true, identical diagnostics are reported only once.
pub deduplicate_diagnostics: bool,
}
impl Drop for HandlerInner {
fn drop(&mut self) {
self.emit_stashed_diagnostics();
if !self.has_errors() {
let bugs = std::mem::replace(&mut self.delayed_span_bugs, Vec::new());
self.flush_delayed(bugs, "no errors encountered even though `delay_span_bug` issued");
}
if !self.has_any_message() {
let bugs = std::mem::replace(&mut self.delayed_good_path_bugs, Vec::new());
self.flush_delayed(
bugs,
"no warnings or errors encountered even though `delayed_good_path_bugs` issued",
);
}
}
}
impl Handler {
pub fn with_tty_emitter(
color_config: ColorConfig,
can_emit_warnings: bool,
treat_err_as_bug: Option<usize>,
sm: Option<Lrc<SourceMap>>,
) -> Self {
Self::with_tty_emitter_and_flags(
color_config,
sm,
HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
)
}
pub fn with_tty_emitter_and_flags(
color_config: ColorConfig,
sm: Option<Lrc<SourceMap>>,
flags: HandlerFlags,
) -> Self {
let emitter = Box::new(EmitterWriter::stderr(
color_config,
sm,
false,
false,
None,
flags.macro_backtrace,
));
Self::with_emitter_and_flags(emitter, flags)
}
pub fn with_emitter(
can_emit_warnings: bool,
treat_err_as_bug: Option<usize>,
emitter: Box<dyn Emitter + sync::Send>,
) -> Self {
Handler::with_emitter_and_flags(
emitter,
HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() },
)
}
pub fn with_emitter_and_flags(
emitter: Box<dyn Emitter + sync::Send>,
flags: HandlerFlags,
) -> Self {
Self {
flags,
inner: Lock::new(HandlerInner {
flags,
err_count: 0,
warn_count: 0,
deduplicated_err_count: 0,
deduplicated_warn_count: 0,
emitter,
delayed_span_bugs: Vec::new(),
delayed_good_path_bugs: Vec::new(),
taught_diagnostics: Default::default(),
emitted_diagnostic_codes: Default::default(),
emitted_diagnostics: Default::default(),
stashed_diagnostics: Default::default(),
future_breakage_diagnostics: Vec::new(),
}),
}
}
// This is here to not allow mutation of flags;
// as of this writing it's only used in tests in librustc_middle.
pub fn can_emit_warnings(&self) -> bool {
self.flags.can_emit_warnings
}
/// Resets the diagnostic error count as well as the cached emitted diagnostics.
///
/// NOTE: *do not* call this function from rustc. It is only meant to be called from external
/// tools that want to reuse a `Parser` cleaning the previously emitted diagnostics as well as
/// the overall count of emitted error diagnostics.
pub fn reset_err_count(&self) {
let mut inner = self.inner.borrow_mut();
inner.err_count = 0;
inner.warn_count = 0;
inner.deduplicated_err_count = 0;
inner.deduplicated_warn_count = 0;
// actually free the underlying memory (which `clear` would not do)
inner.delayed_span_bugs = Default::default();
inner.delayed_good_path_bugs = Default::default();
inner.taught_diagnostics = Default::default();
inner.emitted_diagnostic_codes = Default::default();
inner.emitted_diagnostics = Default::default();
inner.stashed_diagnostics = Default::default();
}
/// Stash a given diagnostic with the given `Span` and `StashKey` as the key for later stealing.
pub fn stash_diagnostic(&self, span: Span, key: StashKey, diag: Diagnostic) {
let mut inner = self.inner.borrow_mut();
// FIXME(Centril, #69537): Consider reintroducing panic on overwriting a stashed diagnostic
// if/when we have a more robust macro-friendly replacement for `(span, key)` as a key.
// See the PR for a discussion.
inner.stashed_diagnostics.insert((span, key), diag);
}
/// Steal a previously stashed diagnostic with the given `Span` and `StashKey` as the key.
pub fn steal_diagnostic(&self, span: Span, key: StashKey) -> Option<DiagnosticBuilder<'_>> {
self.inner
.borrow_mut()
.stashed_diagnostics
.remove(&(span, key))
.map(|diag| DiagnosticBuilder::new_diagnostic(self, diag))
}
/// Emit all stashed diagnostics.
pub fn emit_stashed_diagnostics(&self) {
self.inner.borrow_mut().emit_stashed_diagnostics();
}
/// Construct a dummy builder with `Level::Cancelled`.
///
/// Using this will neither report anything to the user (e.g. a warning),
/// nor will compilation cancel as a result.
pub fn struct_dummy(&self) -> DiagnosticBuilder<'_> {
DiagnosticBuilder::new(self, Level::Cancelled, "")
}
/// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
pub fn struct_span_warn(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> {
let mut result = self.struct_warn(msg);
result.set_span(span);
result
}
/// Construct a builder at the `Allow` level at the given `span` and with the `msg`.
pub fn struct_span_allow(
&self,
span: impl Into<MultiSpan>,
msg: &str,
) -> DiagnosticBuilder<'_> {
let mut result = self.struct_allow(msg);
result.set_span(span);
result
}
/// Construct a builder at the `Warning` level at the given `span` and with the `msg`.
/// Also include a code.
pub fn struct_span_warn_with_code(
&self,
span: impl Into<MultiSpan>,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
let mut result = self.struct_span_warn(span, msg);
result.code(code);
result
}
/// Construct a builder at the `Warning` level with the `msg`.
pub fn struct_warn(&self, msg: &str) -> DiagnosticBuilder<'_> {
let mut result = DiagnosticBuilder::new(self, Level::Warning, msg);
if !self.flags.can_emit_warnings {
result.cancel();
}
result
}
/// Construct a builder at the `Allow` level with the `msg`.
pub fn struct_allow(&self, msg: &str) -> DiagnosticBuilder<'_> {
DiagnosticBuilder::new(self, Level::Allow, msg)
}
/// Construct a builder at the `Error` level at the given `span` and with the `msg`.
pub fn struct_span_err(&self, span: impl Into<MultiSpan>, msg: &str) -> DiagnosticBuilder<'_> {
let mut result = self.struct_err(msg);
result.set_span(span);
result
}
/// Construct a builder at the `Error` level at the given `span`, with the `msg`, and `code`.
pub fn struct_span_err_with_code(
&self,
span: impl Into<MultiSpan>,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
let mut result = self.struct_span_err(span, msg);
result.code(code);
result
}
/// Construct a builder at the `Error` level with the `msg`.
// FIXME: This method should be removed (every error should have an associated error code).
pub fn struct_err(&self, msg: &str) -> DiagnosticBuilder<'_> {
DiagnosticBuilder::new(self, Level::Error, msg)
}
/// Construct a builder at the `Error` level with the `msg` and the `code`.
pub fn struct_err_with_code(&self, msg: &str, code: DiagnosticId) -> DiagnosticBuilder<'_> {
let mut result = self.struct_err(msg);
result.code(code);
result
}
/// Construct a builder at the `Fatal` level at the given `span` and with the `msg`.
pub fn struct_span_fatal(
&self,
span: impl Into<MultiSpan>,
msg: &str,
) -> DiagnosticBuilder<'_> {
let mut result = self.struct_fatal(msg);
result.set_span(span);
result
}
/// Construct a builder at the `Fatal` level at the given `span`, with the `msg`, and `code`.
pub fn struct_span_fatal_with_code(
&self,
span: impl Into<MultiSpan>,
msg: &str,
code: DiagnosticId,
) -> DiagnosticBuilder<'_> {
let mut result = self.struct_span_fatal(span, msg);
result.code(code);
result
}
/// Construct a builder at the `Error` level with the `msg`.
pub fn struct_fatal(&self, msg: &str) -> DiagnosticBuilder<'_> {
DiagnosticBuilder::new(self, Level::Fatal, msg)
}
/// Construct a builder at the `Help` level with the `msg`.
pub fn struct_help(&self, msg: &str) -> DiagnosticBuilder<'_> {
DiagnosticBuilder::new(self, Level::Help, msg)
}
/// Construct a builder at the `Note` level with the `msg`.
pub fn struct_note_without_error(&self, msg: &str) -> DiagnosticBuilder<'_> {
DiagnosticBuilder::new(self, Level::Note, msg)
}
pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: &str) -> FatalError {
self.emit_diag_at_span(Diagnostic::new(Fatal, msg), span);
FatalError
}
pub fn span_fatal_with_code(
&self,
span: impl Into<MultiSpan>,
msg: &str,
code: DiagnosticId,
) -> FatalError {
self.emit_diag_at_span(Diagnostic::new_with_code(Fatal, Some(code), msg), span);
FatalError
}
pub fn span_err(&self, span: impl Into<MultiSpan>, msg: &str) {
self.emit_diag_at_span(Diagnostic::new(Error, msg), span);
}
pub fn span_err_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) {
self.emit_diag_at_span(Diagnostic::new_with_code(Error, Some(code), msg), span);
}
pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: &str) {
self.emit_diag_at_span(Diagnostic::new(Warning, msg), span);
}
pub fn span_warn_with_code(&self, span: impl Into<MultiSpan>, msg: &str, code: DiagnosticId) {
self.emit_diag_at_span(Diagnostic::new_with_code(Warning, Some(code), msg), span);
}
pub fn span_bug(&self, span: impl Into<MultiSpan>, msg: &str) -> ! {
self.inner.borrow_mut().span_bug(span, msg)
}
#[track_caller]
pub fn delay_span_bug(&self, span: impl Into<MultiSpan>, msg: &str) {
self.inner.borrow_mut().delay_span_bug(span, msg)
}
pub fn delay_good_path_bug(&self, msg: &str) {
self.inner.borrow_mut().delay_good_path_bug(msg)
}
pub fn span_bug_no_panic(&self, span: impl Into<MultiSpan>, msg: &str) {
self.emit_diag_at_span(Diagnostic::new(Bug, msg), span);
}
pub fn span_note_without_error(&self, span: impl Into<MultiSpan>, msg: &str) {
self.emit_diag_at_span(Diagnostic::new(Note, msg), span);
}
pub fn span_note_diag(&self, span: Span, msg: &str) -> DiagnosticBuilder<'_> {
let mut db = DiagnosticBuilder::new(self, Note, msg);
db.set_span(span);
db
}
pub fn failure(&self, msg: &str) {
self.inner.borrow_mut().failure(msg);
}
pub fn fatal(&self, msg: &str) -> FatalError {
self.inner.borrow_mut().fatal(msg)
}
pub fn err(&self, msg: &str) {
self.inner.borrow_mut().err(msg);
}
pub fn warn(&self, msg: &str) {
let mut db = DiagnosticBuilder::new(self, Warning, msg);
db.emit();
}
pub fn note_without_error(&self, msg: &str) {
DiagnosticBuilder::new(self, Note, msg).emit();
}
pub fn bug(&self, msg: &str) -> ! {
self.inner.borrow_mut().bug(msg)
}
pub fn err_count(&self) -> usize {
self.inner.borrow().err_count()
}
pub fn has_errors(&self) -> bool {
self.inner.borrow().has_errors()
}
pub fn has_errors_or_delayed_span_bugs(&self) -> bool {
self.inner.borrow().has_errors_or_delayed_span_bugs()
}
pub fn print_error_count(&self, registry: &Registry) {
self.inner.borrow_mut().print_error_count(registry)
}
pub fn take_future_breakage_diagnostics(&self) -> Vec<Diagnostic> {
std::mem::take(&mut self.inner.borrow_mut().future_breakage_diagnostics)
}
pub fn abort_if_errors(&self) {
self.inner.borrow_mut().abort_if_errors()
}
/// `true` if we haven't taught a diagnostic with this code already.
/// The caller must then teach the user about such a diagnostic.
///
/// Used to suppress emitting the same error multiple times with extended explanation when
/// calling `-Zteach`.
pub fn must_teach(&self, code: &DiagnosticId) -> bool {
self.inner.borrow_mut().must_teach(code)
}
pub fn force_print_diagnostic(&self, db: Diagnostic) {
self.inner.borrow_mut().force_print_diagnostic(db)
}
pub fn emit_diagnostic(&self, diagnostic: &Diagnostic) {
self.inner.borrow_mut().emit_diagnostic(diagnostic)
}
fn emit_diag_at_span(&self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
let mut inner = self.inner.borrow_mut();
inner.emit_diagnostic(diag.set_span(sp));
}
pub fn emit_artifact_notification(&self, path: &Path, artifact_type: &str) {
self.inner.borrow_mut().emit_artifact_notification(path, artifact_type)
}
pub fn emit_future_breakage_report(&self, diags: Vec<(FutureBreakage, Diagnostic)>) {
self.inner.borrow_mut().emitter.emit_future_breakage_report(diags)
}
pub fn delay_as_bug(&self, diagnostic: Diagnostic) {
self.inner.borrow_mut().delay_as_bug(diagnostic)
}
}
impl HandlerInner {
fn must_teach(&mut self, code: &DiagnosticId) -> bool {
self.taught_diagnostics.insert(code.clone())
}
fn force_print_diagnostic(&mut self, db: Diagnostic) {
self.emitter.emit_diagnostic(&db);
}
/// Emit all stashed diagnostics.
fn emit_stashed_diagnostics(&mut self) {
let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>();
diags.iter().for_each(|diag| self.emit_diagnostic(diag));
}
fn emit_diagnostic(&mut self, diagnostic: &Diagnostic) {
if diagnostic.cancelled() {
return;
}
if diagnostic.has_future_breakage() {
self.future_breakage_diagnostics.push(diagnostic.clone());
}
if diagnostic.level == Warning && !self.flags.can_emit_warnings {
if diagnostic.has_future_breakage() {
(*TRACK_DIAGNOSTICS)(diagnostic);
}
return;
}
(*TRACK_DIAGNOSTICS)(diagnostic);
if diagnostic.level == Allow {
return;
}
if let Some(ref code) = diagnostic.code {
self.emitted_diagnostic_codes.insert(code.clone());
}
let already_emitted = |this: &mut Self| {
use std::hash::Hash;
let mut hasher = StableHasher::new();
diagnostic.hash(&mut hasher);
let diagnostic_hash = hasher.finish();
!this.emitted_diagnostics.insert(diagnostic_hash)
};
// Only emit the diagnostic if we've been asked to deduplicate and
// haven't already emitted an equivalent diagnostic.
if !(self.flags.deduplicate_diagnostics && already_emitted(self)) {
self.emitter.emit_diagnostic(diagnostic);
if diagnostic.is_error() {
self.deduplicated_err_count += 1;
} else if diagnostic.level == Warning {
self.deduplicated_warn_count += 1;
}
}
if diagnostic.is_error() {
self.bump_err_count();
} else {
self.bump_warn_count();
}
}
fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) {
self.emitter.emit_artifact_notification(path, artifact_type);
}
fn treat_err_as_bug(&self) -> bool {
self.flags.treat_err_as_bug.map(|c| self.err_count() >= c).unwrap_or(false)
}
fn print_error_count(&mut self, registry: &Registry) {
self.emit_stashed_diagnostics();
let warnings = match self.deduplicated_warn_count {
0 => String::new(),
1 => "1 warning emitted".to_string(),
count => format!("{} warnings emitted", count),
};
let errors = match self.deduplicated_err_count {
0 => String::new(),
1 => "aborting due to previous error".to_string(),
count => format!("aborting due to {} previous errors", count),
};
if self.treat_err_as_bug() {
return;
}
match (errors.len(), warnings.len()) {
(0, 0) => return,
(0, _) => self.emit_diagnostic(&Diagnostic::new(Level::Warning, &warnings)),
(_, 0) => {
let _ = self.fatal(&errors);
}
(_, _) => {
let _ = self.fatal(&format!("{}; {}", &errors, &warnings));
}
}
let can_show_explain = self.emitter.should_show_explain();
let are_there_diagnostics = !self.emitted_diagnostic_codes.is_empty();
if can_show_explain && are_there_diagnostics {
let mut error_codes = self
.emitted_diagnostic_codes
.iter()
.filter_map(|x| match &x {
DiagnosticId::Error(s) => {
if let Ok(Some(_explanation)) = registry.try_find_description(s) {
Some(s.clone())
} else {
None
}
}
_ => None,
})
.collect::<Vec<_>>();
if !error_codes.is_empty() {
error_codes.sort();
if error_codes.len() > 1 {
let limit = if error_codes.len() > 9 { 9 } else { error_codes.len() };
self.failure(&format!(
"Some errors have detailed explanations: {}{}",
error_codes[..limit].join(", "),
if error_codes.len() > 9 { "..." } else { "." }
));
self.failure(&format!(
"For more information about an error, try \
`rustc --explain {}`.",
&error_codes[0]
));
} else {
self.failure(&format!(
"For more information about this error, try \
`rustc --explain {}`.",
&error_codes[0]
));
}
}
}
}
fn err_count(&self) -> usize {
self.err_count + self.stashed_diagnostics.len()
}
fn has_errors(&self) -> bool {
self.err_count() > 0
}
fn has_errors_or_delayed_span_bugs(&self) -> bool {
self.has_errors() || !self.delayed_span_bugs.is_empty()
}
fn has_any_message(&self) -> bool {
self.err_count() > 0 || self.warn_count > 0
}
fn abort_if_errors(&mut self) {
self.emit_stashed_diagnostics();
if self.has_errors() {
FatalError.raise();
}
}
fn span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) -> ! {
self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp);
panic!(ExplicitBug);
}
fn emit_diag_at_span(&mut self, mut diag: Diagnostic, sp: impl Into<MultiSpan>) {
self.emit_diagnostic(diag.set_span(sp));
}
#[track_caller]
fn delay_span_bug(&mut self, sp: impl Into<MultiSpan>, msg: &str) {
// This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
// incrementing `err_count` by one, so we need to +1 the comparing.
// FIXME: Would be nice to increment err_count in a more coherent way.
if self.flags.treat_err_as_bug.map(|c| self.err_count() + 1 >= c).unwrap_or(false) {
// FIXME: don't abort here if report_delayed_bugs is off
self.span_bug(sp, msg);
}
let mut diagnostic = Diagnostic::new(Level::Bug, msg);
diagnostic.set_span(sp.into());
diagnostic.note(&format!("delayed at {}", std::panic::Location::caller()));
self.delay_as_bug(diagnostic)
}
fn delay_good_path_bug(&mut self, msg: &str) {
let mut diagnostic = Diagnostic::new(Level::Bug, msg);
if self.flags.report_delayed_bugs {
self.emit_diagnostic(&diagnostic);
}
diagnostic.note(&format!("delayed at {}", std::backtrace::Backtrace::force_capture()));
self.delayed_good_path_bugs.push(diagnostic);
}
fn failure(&mut self, msg: &str) {
self.emit_diagnostic(&Diagnostic::new(FailureNote, msg));
}
fn fatal(&mut self, msg: &str) -> FatalError {
self.emit_error(Fatal, msg);
FatalError
}
fn err(&mut self, msg: &str) {
self.emit_error(Error, msg);
}
/// Emit an error; level should be `Error` or `Fatal`.
fn emit_error(&mut self, level: Level, msg: &str) {
if self.treat_err_as_bug() {
self.bug(msg);
}
self.emit_diagnostic(&Diagnostic::new(level, msg));
}
fn bug(&mut self, msg: &str) -> ! {
self.emit_diagnostic(&Diagnostic::new(Bug, msg));
panic!(ExplicitBug);
}
fn delay_as_bug(&mut self, diagnostic: Diagnostic) {
if self.flags.report_delayed_bugs {
self.emit_diagnostic(&diagnostic);
}
self.delayed_span_bugs.push(diagnostic);
}
fn flush_delayed(&mut self, bugs: Vec<Diagnostic>, explanation: &str) {
let has_bugs = !bugs.is_empty();
for bug in bugs {
self.emit_diagnostic(&bug);
}
if has_bugs {
panic!("{}", explanation);
}
}
fn bump_err_count(&mut self) {
self.err_count += 1;
self.panic_if_treat_err_as_bug();
}
fn bump_warn_count(&mut self) {
self.warn_count += 1;
}
fn panic_if_treat_err_as_bug(&self) {
if self.treat_err_as_bug() {
match (self.err_count(), self.flags.treat_err_as_bug.unwrap_or(0)) {
(1, 1) => panic!("aborting due to `-Z treat-err-as-bug=1`"),
(0, _) | (1, _) => {}
(count, as_bug) => panic!(
"aborting after {} errors due to `-Z treat-err-as-bug={}`",
count, as_bug,
),
}
}
}
}
#[derive(Copy, PartialEq, Clone, Hash, Debug, Encodable, Decodable)]
pub enum Level {
Bug,
Fatal,
Error,
Warning,
Note,
Help,
Cancelled,
FailureNote,
Allow,
}
impl fmt::Display for Level {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.to_str().fmt(f)
}
}
impl Level {
fn color(self) -> ColorSpec {
let mut spec = ColorSpec::new();
match self {
Bug | Fatal | Error => {
spec.set_fg(Some(Color::Red)).set_intense(true);
}
Warning => {
spec.set_fg(Some(Color::Yellow)).set_intense(cfg!(windows));
}
Note => {
spec.set_fg(Some(Color::Green)).set_intense(true);
}
Help => {
spec.set_fg(Some(Color::Cyan)).set_intense(true);
}
FailureNote => {}
Allow | Cancelled => unreachable!(),
}
spec
}
pub fn to_str(self) -> &'static str {
match self {
Bug => "error: internal compiler error",
Fatal | Error => "error",
Warning => "warning",
Note => "note",
Help => "help",
FailureNote => "failure-note",
Cancelled => panic!("Shouldn't call on cancelled error"),
Allow => panic!("Shouldn't call on allowed error"),
}
}
pub fn is_failure_note(&self) -> bool {
matches!(*self, FailureNote)
}
}
pub fn add_elided_lifetime_in_path_suggestion(
source_map: &SourceMap,
db: &mut DiagnosticBuilder<'_>,
n: usize,
path_span: Span,
incl_angl_brckt: bool,
insertion_span: Span,
anon_lts: String,
) {
let (replace_span, suggestion) = if incl_angl_brckt {
(insertion_span, anon_lts)
} else {
// When possible, prefer a suggestion that replaces the whole
// `Path<T>` expression with `Path<'_, T>`, rather than inserting `'_, `
// at a point (which makes for an ugly/confusing label)
if let Ok(snippet) = source_map.span_to_snippet(path_span) {
// But our spans can get out of whack due to macros; if the place we think
// we want to insert `'_` isn't even within the path expression's span, we
// should bail out of making any suggestion rather than panicking on a
// subtract-with-overflow or string-slice-out-out-bounds (!)
// FIXME: can we do better?
if insertion_span.lo().0 < path_span.lo().0 {
return;
}
let insertion_index = (insertion_span.lo().0 - path_span.lo().0) as usize;
if insertion_index > snippet.len() {
return;
}
let (before, after) = snippet.split_at(insertion_index);
(path_span, format!("{}{}{}", before, anon_lts, after))
} else {
(insertion_span, anon_lts)
}
};
db.span_suggestion(
replace_span,
&format!("indicate the anonymous lifetime{}", pluralize!(n)),
suggestion,
Applicability::MachineApplicable,
);
}
// Useful type to use with `Result<>` indicate that an error has already
// been reported to the user, so no need to continue checking.
#[derive(Clone, Copy, Debug, Encodable, Decodable, Hash, PartialEq, Eq)]
pub struct ErrorReported;
rustc_data_structures::impl_stable_hash_via_hash!(ErrorReported);