//! 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(drain_filter)] #![feature(backtrace)] #![feature(if_let_guard)] #![feature(let_else)] #![feature(never_type)] #![feature(adt_const_params)] #![allow(incomplete_features)] #![allow(rustc::potential_query_instability)] #[macro_use] extern crate rustc_macros; #[macro_use] extern crate tracing; pub use emitter::ColorConfig; use rustc_lint_defs::LintExpectationId; use Level::*; use emitter::{is_case_difference, Emitter, EmitterWriter}; use registry::Registry; use rustc_data_structures::fx::{FxHashMap, FxHashSet, FxIndexMap}; use rustc_data_structures::stable_hasher::StableHasher; use rustc_data_structures::sync::{self, Lock, Lrc}; use rustc_data_structures::AtomicRef; pub use rustc_error_messages::{ fallback_fluent_bundle, fluent, fluent_bundle, DiagnosticMessage, FluentBundle, LanguageIdentifier, LazyFallbackBundle, MultiSpan, SpanLabel, SubdiagnosticMessage, DEFAULT_LOCALE_RESOURCES, }; pub use rustc_lint_defs::{pluralize, Applicability}; use rustc_span::source_map::SourceMap; use rustc_span::HashStableContext; use rustc_span::{Loc, Span}; use std::borrow::Cow; use std::hash::Hash; use std::num::NonZeroUsize; 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, ErrorGuaranteed>>; // `PResult` is used a lot. Make sure it doesn't unintentionally get bigger. // (See also the comment on `DiagnosticBuilder`'s `diagnostic` field.) #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] rustc_data_structures::static_assert_size!(PResult<'_, ()>, 16); #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] rustc_data_structures::static_assert_size!(PResult<'_, bool>, 24); #[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: /// /// ```ignore (illustrative) /// 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: /// /// ```ignore (illustrative) /// vec![ /// Substitution { parts: vec![(0..7, "a.b")] }, /// Substitution { parts: vec![(0..7, "x.y")] }, /// ] /// ``` pub substitutions: Vec<Substitution>, pub msg: DiagnosticMessage, /// 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, } /// Used to translate between `Span`s and byte positions within a single output line in highlighted /// code of structured suggestions. #[derive(Debug, Clone, Copy)] pub struct SubstitutionHighlight { start: usize, end: usize, } impl SubstitutionPart { pub fn is_addition(&self, sm: &SourceMap) -> bool { !self.snippet.is_empty() && sm .span_to_snippet(self.span) .map_or(self.span.is_empty(), |snippet| snippet.trim().is_empty()) } pub fn is_deletion(&self) -> bool { self.snippet.trim().is_empty() } pub fn is_replacement(&self, sm: &SourceMap) -> bool { !self.snippet.is_empty() && sm .span_to_snippet(self.span) .map_or(!self.span.is_empty(), |snippet| !snippet.trim().is_empty()) } } 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>, Vec<Vec<SubstitutionHighlight>>, bool)> { // For the `Vec<Vec<SubstitutionHighlight>>` value, the first level of the vector // corresponds to the output snippet's lines, while the second level corresponds to the // substrings within that line that should be highlighted. use rustc_span::{CharPos, Pos}; /// Append to a buffer the remainder of the line of existing source code, and return the /// count of lines that have been added for accurate highlighting. fn push_trailing( buf: &mut String, line_opt: Option<&Cow<'_, str>>, lo: &Loc, hi_opt: Option<&Loc>, ) -> usize { let mut line_count = 0; 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 => { line_count = line[lo..hi].matches('\n').count(); buf.push_str(&line[lo..hi]) } Some(_) => (), None => { line_count = line[lo..].matches('\n').count(); buf.push_str(&line[lo..]) } } } if hi_opt.is_none() { buf.push('\n'); } } line_count } 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; } let mut highlights = vec![]; // 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(); let mut line_highlight = vec![]; // We need to keep track of the difference between the existing code and the added // or deleted code in order to point at the correct column *after* substitution. let mut acc = 0; for part in &substitution.parts { let cur_lo = sm.lookup_char_pos(part.span.lo()); if prev_hi.line == cur_lo.line { let mut count = push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, Some(&cur_lo)); while count > 0 { highlights.push(std::mem::take(&mut line_highlight)); acc = 0; count -= 1; } } else { acc = 0; highlights.push(std::mem::take(&mut line_highlight)); let mut count = push_trailing(&mut buf, prev_line.as_ref(), &prev_hi, None); while count > 0 { highlights.push(std::mem::take(&mut line_highlight)); count -= 1; } // 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'); highlights.push(std::mem::take(&mut line_highlight)); } } 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]); } } // Add a whole line highlight per line in the snippet. let len: isize = part .snippet .split('\n') .next() .unwrap_or(&part.snippet) .chars() .map(|c| match c { '\t' => 4, _ => 1, }) .sum(); line_highlight.push(SubstitutionHighlight { start: (cur_lo.col.0 as isize + acc) as usize, end: (cur_lo.col.0 as isize + acc + len) as usize, }); buf.push_str(&part.snippet); let cur_hi = sm.lookup_char_pos(part.span.hi()); if prev_hi.line == cur_lo.line && cur_hi.line == cur_lo.line { // Account for the difference between the width of the current code and the // snippet being suggested, so that the *later* suggestions are correctly // aligned on the screen. acc += len as isize - (cur_hi.col.0 - cur_lo.col.0) as isize; } prev_hi = cur_hi; prev_line = sf.get_line(prev_hi.line - 1); for line in part.snippet.split('\n').skip(1) { acc = 0; highlights.push(std::mem::take(&mut line_highlight)); let end: usize = line .chars() .map(|c| match c { '\t' => 4, _ => 1, }) .sum(); line_highlight.push(SubstitutionHighlight { start: 0, end }); } } highlights.push(std::mem::take(&mut line_highlight)); 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, highlights, 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::{ AddSubdiagnostic, Diagnostic, DiagnosticArg, DiagnosticArgValue, DiagnosticId, DiagnosticStyledString, IntoDiagnosticArg, SubDiagnostic, }; pub use diagnostic_builder::{DiagnosticBuilder, EmissionGuarantee}; use std::backtrace::Backtrace; /// 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 lint errors that have been emitted. lint_err_count: usize, /// 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<DelayedDiagnostic>, /// This set contains the `DiagnosticId` of all emitted diagnostics to avoid /// emitting the same diagnostic with extended help (`--teach`) twice, which /// would be unnecessary 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>, /// The [`Self::unstable_expect_diagnostics`] should be empty when this struct is /// dropped. However, it can have values if the compilation is stopped early /// or is only partially executed. To avoid ICEs, like in rust#94953 we only /// check if [`Self::unstable_expect_diagnostics`] is empty, if the expectation ids /// have been converted. check_unstable_expect_diagnostics: bool, /// Expected [`Diagnostic`]s store a [`LintExpectationId`] as part of /// the lint level. [`LintExpectationId`]s created early during the compilation /// (before `HirId`s have been defined) are not stable and can therefore not be /// stored on disk. This buffer stores these diagnostics until the ID has been /// replaced by a stable [`LintExpectationId`]. The [`Diagnostic`]s are the /// submitted for storage and added to the list of fulfilled expectations. unstable_expect_diagnostics: Vec<Diagnostic>, /// expected diagnostic will have the level `Expect` which additionally /// carries the [`LintExpectationId`] of the expectation that can be /// marked as fulfilled. This is a collection of all [`LintExpectationId`]s /// that have been marked as fulfilled this way. /// /// [RFC-2383]: https://rust-lang.github.io/rfcs/2383-lint-reasons.html fulfilled_expectations: FxHashSet<LintExpectationId>, } /// 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<NonZeroUsize>, /// 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"); } // FIXME(eddyb) this explains what `delayed_good_path_bugs` are! // They're `delayed_span_bugs` but for "require some diagnostic happened" // instead of "require some error happened". Sadly that isn't ideal, as // lints can be `#[allow]`'d, potentially leading to this triggering. // Also, "good path" should be replaced with a better naming. if !self.has_any_message() { let bugs = std::mem::replace(&mut self.delayed_good_path_bugs, Vec::new()); self.flush_delayed( bugs.into_iter().map(DelayedDiagnostic::decorate), "no warnings or errors encountered even though `delayed_good_path_bugs` issued", ); } if self.check_unstable_expect_diagnostics { assert!( self.unstable_expect_diagnostics.is_empty(), "all diagnostics with unstable expectations should have been converted", ); } } } impl Handler { pub fn with_tty_emitter( color_config: ColorConfig, can_emit_warnings: bool, treat_err_as_bug: Option<NonZeroUsize>, sm: Option<Lrc<SourceMap>>, fluent_bundle: Option<Lrc<FluentBundle>>, fallback_bundle: LazyFallbackBundle, ) -> Self { Self::with_tty_emitter_and_flags( color_config, sm, fluent_bundle, fallback_bundle, HandlerFlags { can_emit_warnings, treat_err_as_bug, ..Default::default() }, ) } pub fn with_tty_emitter_and_flags( color_config: ColorConfig, sm: Option<Lrc<SourceMap>>, fluent_bundle: Option<Lrc<FluentBundle>>, fallback_bundle: LazyFallbackBundle, flags: HandlerFlags, ) -> Self { let emitter = Box::new(EmitterWriter::stderr( color_config, sm, fluent_bundle, fallback_bundle, 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<NonZeroUsize>, 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, lint_err_count: 0, 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(), check_unstable_expect_diagnostics: false, unstable_expect_diagnostics: Vec::new(), fulfilled_expectations: Default::default(), }), } } // 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) -> Option<ErrorGuaranteed> { self.inner.borrow_mut().emit_stashed_diagnostics() } /// Construct a builder at the `Warning` level at the given `span` and with the `msg`. /// /// Attempting to `.emit()` the builder will only emit if either: /// * `can_emit_warnings` is `true` /// * `is_force_warn` was set in `DiagnosticId::Lint` pub fn struct_span_warn( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, ) -> 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: impl Into<DiagnosticMessage>, ) -> 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: impl Into<DiagnosticMessage>, 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`. /// /// Attempting to `.emit()` the builder will only emit if either: /// * `can_emit_warnings` is `true` /// * `is_force_warn` was set in `DiagnosticId::Lint` pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> { DiagnosticBuilder::new(self, Level::Warning, msg) } /// Construct a builder at the `Allow` level with the `msg`. pub fn struct_allow(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> { DiagnosticBuilder::new(self, Level::Allow, msg) } /// Construct a builder at the `Expect` level with the `msg`. pub fn struct_expect( &self, msg: impl Into<DiagnosticMessage>, id: LintExpectationId, ) -> DiagnosticBuilder<'_, ()> { DiagnosticBuilder::new(self, Level::Expect(id), 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: impl Into<DiagnosticMessage>, ) -> DiagnosticBuilder<'_, ErrorGuaranteed> { 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: impl Into<DiagnosticMessage>, code: DiagnosticId, ) -> DiagnosticBuilder<'_, ErrorGuaranteed> { 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: impl Into<DiagnosticMessage>, ) -> DiagnosticBuilder<'_, ErrorGuaranteed> { DiagnosticBuilder::new_guaranteeing_error::<_, { Level::Error { lint: false } }>(self, msg) } /// This should only be used by `rustc_middle::lint::struct_lint_level`. Do not use it for hard errors. #[doc(hidden)] pub fn struct_err_lint(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> { DiagnosticBuilder::new(self, Level::Error { lint: true }, msg) } /// Construct a builder at the `Error` level with the `msg` and the `code`. pub fn struct_err_with_code( &self, msg: impl Into<DiagnosticMessage>, code: DiagnosticId, ) -> DiagnosticBuilder<'_, ErrorGuaranteed> { let mut result = self.struct_err(msg); result.code(code); result } /// Construct a builder at the `Warn` level with the `msg` and the `code`. pub fn struct_warn_with_code( &self, msg: impl Into<DiagnosticMessage>, code: DiagnosticId, ) -> DiagnosticBuilder<'_, ()> { let mut result = self.struct_warn(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: impl Into<DiagnosticMessage>, ) -> 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: impl Into<DiagnosticMessage>, 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: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, !> { DiagnosticBuilder::new_fatal(self, msg) } /// Construct a builder at the `Help` level with the `msg`. pub fn struct_help(&self, msg: impl Into<DiagnosticMessage>) -> 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: impl Into<DiagnosticMessage>, ) -> DiagnosticBuilder<'_, ()> { DiagnosticBuilder::new(self, Level::Note, msg) } pub fn span_fatal(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) -> ! { self.emit_diag_at_span(Diagnostic::new(Fatal, msg), span); FatalError.raise() } pub fn span_fatal_with_code( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, code: DiagnosticId, ) -> ! { self.emit_diag_at_span(Diagnostic::new_with_code(Fatal, Some(code), msg), span); FatalError.raise() } pub fn span_err( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, ) -> ErrorGuaranteed { self.emit_diag_at_span(Diagnostic::new(Error { lint: false }, msg), span).unwrap() } pub fn span_err_with_code( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, code: DiagnosticId, ) { self.emit_diag_at_span( Diagnostic::new_with_code(Error { lint: false }, Some(code), msg), span, ); } pub fn span_warn(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) { self.emit_diag_at_span(Diagnostic::new(Warning, msg), span); } pub fn span_warn_with_code( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, 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: impl Into<DiagnosticMessage>) -> ! { self.inner.borrow_mut().span_bug(span, msg) } #[track_caller] pub fn delay_span_bug( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, ) -> ErrorGuaranteed { self.inner.borrow_mut().delay_span_bug(span, msg) } // FIXME(eddyb) note the comment inside `impl Drop for HandlerInner`, that's // where the explanation of what "good path" is (also, it should be renamed). pub fn delay_good_path_bug(&self, msg: impl Into<DiagnosticMessage>) { self.inner.borrow_mut().delay_good_path_bug(msg) } pub fn span_bug_no_panic(&self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) { self.emit_diag_at_span(Diagnostic::new(Bug, msg), span); } pub fn span_note_without_error( &self, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>, ) { self.emit_diag_at_span(Diagnostic::new(Note, msg), span); } pub fn span_note_diag( &self, span: Span, msg: impl Into<DiagnosticMessage>, ) -> DiagnosticBuilder<'_, ()> { let mut db = DiagnosticBuilder::new(self, Note, msg); db.set_span(span); db } // NOTE: intentionally doesn't raise an error so rustc_codegen_ssa only reports fatal errors in the main thread pub fn fatal(&self, msg: impl Into<DiagnosticMessage>) -> FatalError { self.inner.borrow_mut().fatal(msg) } pub fn err(&self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed { self.inner.borrow_mut().err(msg) } pub fn warn(&self, msg: impl Into<DiagnosticMessage>) { let mut db = DiagnosticBuilder::new(self, Warning, msg); db.emit(); } pub fn note_without_error(&self, msg: impl Into<DiagnosticMessage>) { DiagnosticBuilder::new(self, Note, msg).emit(); } pub fn bug(&self, msg: impl Into<DiagnosticMessage>) -> ! { self.inner.borrow_mut().bug(msg) } #[inline] pub fn err_count(&self) -> usize { self.inner.borrow().err_count() } pub fn has_errors(&self) -> Option<ErrorGuaranteed> { if self.inner.borrow().has_errors() { Some(ErrorGuaranteed(())) } else { None } } pub fn has_errors_or_lint_errors(&self) -> Option<ErrorGuaranteed> { if self.inner.borrow().has_errors_or_lint_errors() { Some(ErrorGuaranteed(())) } else { None } } 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: &mut Diagnostic) -> Option<ErrorGuaranteed> { self.inner.borrow_mut().emit_diagnostic(diagnostic) } fn emit_diag_at_span( &self, mut diag: Diagnostic, sp: impl Into<MultiSpan>, ) -> Option<ErrorGuaranteed> { 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<Diagnostic>) { self.inner.borrow_mut().emitter.emit_future_breakage_report(diags) } pub fn emit_unused_externs( &self, lint_level: rustc_lint_defs::Level, loud: bool, unused_externs: &[&str], ) { let mut inner = self.inner.borrow_mut(); if loud && lint_level.is_error() { inner.bump_err_count(); } inner.emit_unused_externs(lint_level, unused_externs) } pub fn update_unstable_expectation_id( &self, unstable_to_stable: &FxHashMap<LintExpectationId, LintExpectationId>, ) { let mut inner = self.inner.borrow_mut(); let diags = std::mem::take(&mut inner.unstable_expect_diagnostics); inner.check_unstable_expect_diagnostics = true; if diags.is_empty() { return; } for mut diag in diags.into_iter() { diag.update_unstable_expectation_id(unstable_to_stable); let stable_id = diag .level .get_expectation_id() .expect("all diagnostics inside `unstable_expect_diagnostics` must have a `LintExpectationId`"); inner.fulfilled_expectations.insert(stable_id); (*TRACK_DIAGNOSTICS)(&diag); } inner .stashed_diagnostics .values_mut() .for_each(|diag| diag.update_unstable_expectation_id(unstable_to_stable)); inner .future_breakage_diagnostics .iter_mut() .for_each(|diag| diag.update_unstable_expectation_id(unstable_to_stable)); } /// This methods steals all [`LintExpectationId`]s that are stored inside /// [`HandlerInner`] and indicate that the linked expectation has been fulfilled. #[must_use] pub fn steal_fulfilled_expectation_ids(&self) -> FxHashSet<LintExpectationId> { assert!( self.inner.borrow().unstable_expect_diagnostics.is_empty(), "`HandlerInner::unstable_expect_diagnostics` should be empty at this point", ); std::mem::take(&mut self.inner.borrow_mut().fulfilled_expectations) } } impl HandlerInner { fn must_teach(&mut self, code: &DiagnosticId) -> bool { self.taught_diagnostics.insert(code.clone()) } fn force_print_diagnostic(&mut self, mut db: Diagnostic) { self.emitter.emit_diagnostic(&mut db); } /// Emit all stashed diagnostics. fn emit_stashed_diagnostics(&mut self) -> Option<ErrorGuaranteed> { let diags = self.stashed_diagnostics.drain(..).map(|x| x.1).collect::<Vec<_>>(); let mut reported = None; for mut diag in diags { if diag.is_error() { reported = Some(ErrorGuaranteed(())); } self.emit_diagnostic(&mut diag); } reported } // FIXME(eddyb) this should ideally take `diagnostic` by value. fn emit_diagnostic(&mut self, diagnostic: &mut Diagnostic) -> Option<ErrorGuaranteed> { if diagnostic.level == Level::DelayedBug { // FIXME(eddyb) this should check for `has_errors` and stop pushing // once *any* errors were emitted (and truncate `delayed_span_bugs` // when an error is first emitted, also), but maybe there's a case // in which that's not sound? otherwise this is really inefficient. self.delayed_span_bugs.push(diagnostic.clone()); if !self.flags.report_delayed_bugs { return Some(ErrorGuaranteed::unchecked_claim_error_was_emitted()); } } if diagnostic.has_future_breakage() { self.future_breakage_diagnostics.push(diagnostic.clone()); } if diagnostic.level == Warning && !self.flags.can_emit_warnings && !diagnostic.is_force_warn() { if diagnostic.has_future_breakage() { (*TRACK_DIAGNOSTICS)(diagnostic); } return None; } // The `LintExpectationId` can be stable or unstable depending on when it was created. // Diagnostics created before the definition of `HirId`s are unstable and can not yet // be stored. Instead, they are buffered until the `LintExpectationId` is replaced by // a stable one by the `LintLevelsBuilder`. if let Level::Expect(LintExpectationId::Unstable { .. }) = diagnostic.level { self.unstable_expect_diagnostics.push(diagnostic.clone()); return None; } (*TRACK_DIAGNOSTICS)(diagnostic); if let Level::Expect(expectation_id) = diagnostic.level { self.fulfilled_expectations.insert(expectation_id); return None; } else if diagnostic.level == Allow { return None; } if let Some(ref code) = diagnostic.code { self.emitted_diagnostic_codes.insert(code.clone()); } let already_emitted = |this: &mut Self| { 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)) { debug!(?diagnostic); debug!(?self.emitted_diagnostics); let already_emitted_sub = |sub: &mut SubDiagnostic| { debug!(?sub); if sub.level != Level::OnceNote { return false; } let mut hasher = StableHasher::new(); sub.hash(&mut hasher); let diagnostic_hash = hasher.finish(); debug!(?diagnostic_hash); !self.emitted_diagnostics.insert(diagnostic_hash) }; diagnostic.children.drain_filter(already_emitted_sub).for_each(|_| {}); 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() { if matches!(diagnostic.level, Level::Error { lint: true }) { self.bump_lint_err_count(); } else { self.bump_err_count(); } Some(ErrorGuaranteed::unchecked_claim_error_was_emitted()) } else { self.bump_warn_count(); None } } fn emit_artifact_notification(&mut self, path: &Path, artifact_type: &str) { self.emitter.emit_artifact_notification(path, artifact_type); } fn emit_unused_externs(&mut self, lint_level: rustc_lint_defs::Level, unused_externs: &[&str]) { self.emitter.emit_unused_externs(lint_level, unused_externs); } fn treat_err_as_bug(&self) -> bool { self.flags .treat_err_as_bug .map_or(false, |c| self.err_count() + self.lint_err_count >= c.get()) } 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!("{count} warnings emitted"), }; let errors = match self.deduplicated_err_count { 0 => String::new(), 1 => "aborting due to previous error".to_string(), count => format!("aborting due to {count} previous errors"), }; if self.treat_err_as_bug() { return; } match (errors.len(), warnings.len()) { (0, 0) => return, (0, _) => self.emitter.emit_diagnostic(&Diagnostic::new( Level::Warning, DiagnosticMessage::Str(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 registry.try_find_description(s).map_or(false, |o| o.is_some()) => { Some(s.clone()) } _ => 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] )); } } } } #[inline] 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_lint_errors(&self) -> bool { self.has_errors() || self.lint_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.lint_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: impl Into<DiagnosticMessage>) -> ! { self.emit_diag_at_span(Diagnostic::new(Bug, msg), sp); panic::panic_any(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: impl Into<DiagnosticMessage>, ) -> ErrorGuaranteed { // 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_or(false, |c| self.err_count() + 1 >= c.get()) { // FIXME: don't abort here if report_delayed_bugs is off self.span_bug(sp, msg); } let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg); diagnostic.set_span(sp.into()); diagnostic.note(&format!("delayed at {}", std::panic::Location::caller())); self.emit_diagnostic(&mut diagnostic).unwrap() } // FIXME(eddyb) note the comment inside `impl Drop for HandlerInner`, that's // where the explanation of what "good path" is (also, it should be renamed). fn delay_good_path_bug(&mut self, msg: impl Into<DiagnosticMessage>) { let mut diagnostic = Diagnostic::new(Level::DelayedBug, msg); if self.flags.report_delayed_bugs { self.emit_diagnostic(&mut diagnostic); } let backtrace = std::backtrace::Backtrace::force_capture(); self.delayed_good_path_bugs.push(DelayedDiagnostic::with_backtrace(diagnostic, backtrace)); } fn failure(&mut self, msg: impl Into<DiagnosticMessage>) { self.emit_diagnostic(&mut Diagnostic::new(FailureNote, msg)); } fn fatal(&mut self, msg: impl Into<DiagnosticMessage>) -> FatalError { self.emit(Fatal, msg); FatalError } fn err(&mut self, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed { self.emit(Error { lint: false }, msg) } /// Emit an error; level should be `Error` or `Fatal`. fn emit(&mut self, level: Level, msg: impl Into<DiagnosticMessage>) -> ErrorGuaranteed { if self.treat_err_as_bug() { self.bug(msg); } self.emit_diagnostic(&mut Diagnostic::new(level, msg)).unwrap() } fn bug(&mut self, msg: impl Into<DiagnosticMessage>) -> ! { self.emit_diagnostic(&mut Diagnostic::new(Bug, msg)); panic::panic_any(ExplicitBug); } fn flush_delayed( &mut self, bugs: impl IntoIterator<Item = Diagnostic>, explanation: impl Into<DiagnosticMessage> + Copy, ) { let mut no_bugs = true; for mut bug in bugs { if no_bugs { // Put the overall explanation before the `DelayedBug`s, to // frame them better (e.g. separate warnings from them). self.emit_diagnostic(&mut Diagnostic::new(Bug, explanation)); no_bugs = false; } // "Undelay" the `DelayedBug`s (into plain `Bug`s). if bug.level != Level::DelayedBug { // NOTE(eddyb) not panicking here because we're already producing // an ICE, and the more information the merrier. bug.note(&format!( "`flushed_delayed` got diagnostic with level {:?}, \ instead of the expected `DelayedBug`", bug.level, )); } bug.level = Level::Bug; self.emit_diagnostic(&mut bug); } // Panic with `ExplicitBug` to avoid "unexpected panic" messages. if !no_bugs { panic::panic_any(ExplicitBug); } } fn bump_lint_err_count(&mut self) { self.lint_err_count += 1; self.panic_if_treat_err_as_bug(); } 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.lint_err_count, self.flags.treat_err_as_bug.map(|c| c.get()).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, ), } } } } struct DelayedDiagnostic { inner: Diagnostic, note: Backtrace, } impl DelayedDiagnostic { fn with_backtrace(diagnostic: Diagnostic, backtrace: Backtrace) -> Self { DelayedDiagnostic { inner: diagnostic, note: backtrace } } fn decorate(mut self) -> Diagnostic { self.inner.note(&format!("delayed at {}", self.note)); self.inner } } #[derive(Copy, PartialEq, Eq, Clone, Hash, Debug, Encodable, Decodable)] pub enum Level { Bug, DelayedBug, Fatal, Error { /// If this error comes from a lint, don't abort compilation even when abort_if_errors() is called. lint: bool, }, Warning, Note, /// A note that is only emitted once. OnceNote, Help, FailureNote, Allow, Expect(LintExpectationId), } 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 | DelayedBug | Fatal | Error { .. } => { spec.set_fg(Some(Color::Red)).set_intense(true); } Warning => { spec.set_fg(Some(Color::Yellow)).set_intense(cfg!(windows)); } Note | OnceNote => { spec.set_fg(Some(Color::Green)).set_intense(true); } Help => { spec.set_fg(Some(Color::Cyan)).set_intense(true); } FailureNote => {} Allow | Expect(_) => unreachable!(), } spec } pub fn to_str(self) -> &'static str { match self { Bug | DelayedBug => "error: internal compiler error", Fatal | Error { .. } => "error", Warning => "warning", Note | OnceNote => "note", Help => "help", FailureNote => "failure-note", Allow => panic!("Shouldn't call on allowed error"), Expect(_) => panic!("Shouldn't call on expected error"), } } pub fn is_failure_note(&self) -> bool { matches!(*self, FailureNote) } pub fn get_expectation_id(&self) -> Option<LintExpectationId> { match self { Level::Expect(id) => Some(*id), _ => None, } } } // FIXME(eddyb) this doesn't belong here AFAICT, should be moved to callsite. pub fn add_elided_lifetime_in_path_suggestion( source_map: &SourceMap, diag: &mut Diagnostic, n: usize, path_span: Span, incl_angl_brckt: bool, insertion_span: Span, ) { diag.span_label(path_span, format!("expected lifetime parameter{}", pluralize!(n))); if source_map.span_to_snippet(insertion_span).is_err() { // Do not try to suggest anything if generated by a proc-macro. return; } let anon_lts = vec!["'_"; n].join(", "); let suggestion = if incl_angl_brckt { format!("<{}>", anon_lts) } else { format!("{}, ", anon_lts) }; diag.span_suggestion_verbose( insertion_span.shrink_to_hi(), &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, PartialOrd, Ord)] #[derive(HashStable_Generic)] pub struct ErrorGuaranteed(()); impl ErrorGuaranteed { /// To be used only if you really know what you are doing... ideally, we would find a way to /// eliminate all calls to this method. pub fn unchecked_claim_error_was_emitted() -> Self { ErrorGuaranteed(()) } }