1 //! Implementation of lint checking.
3 //! The lint checking is mostly consolidated into one pass which runs
4 //! after all other analyses. Throughout compilation, lint warnings
5 //! can be added via the `add_lint` method on the Session structure. This
6 //! requires a span and an ID of the node that the lint is being added to. The
7 //! lint isn't actually emitted at that time because it is unknown what the
8 //! actual lint level at that location is.
10 //! To actually emit lint warnings/errors, a separate pass is used.
11 //! A context keeps track of the current state of all lint levels.
12 //! Upon entering a node of the ast which can modify the lint settings, the
13 //! previous lint state is pushed onto a stack and the ast is then recursed
14 //! upon. As the ast is traversed, this keeps track of the current lint level
15 //! for all lint attributes.
17 use self::TargetLint::*;
20 use rustc_data_structures::sync::{ReadGuard, Lock, ParallelIterator, join, par_iter};
21 use crate::lint::{EarlyLintPass, LateLintPass, EarlyLintPassObject, LateLintPassObject};
22 use crate::lint::{LintArray, Level, Lint, LintId, LintPass, LintBuffer};
23 use crate::lint::builtin::BuiltinLintDiagnostics;
24 use crate::lint::levels::{LintLevelSets, LintLevelsBuilder};
25 use crate::middle::privacy::AccessLevels;
26 use crate::rustc_serialize::{Decoder, Decodable, Encoder, Encodable};
27 use crate::session::{config, early_error, Session};
28 use crate::ty::{self, print::Printer, subst::Kind, TyCtxt, Ty};
29 use crate::ty::layout::{LayoutError, LayoutOf, TyLayout};
30 use crate::util::nodemap::FxHashMap;
31 use crate::util::common::time;
33 use std::default::Default as StdDefault;
36 use syntax_pos::{MultiSpan, Span, symbol::{LocalInternedString, Symbol}};
37 use errors::DiagnosticBuilder;
39 use crate::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
40 use crate::hir::intravisit as hir_visit;
41 use crate::hir::intravisit::Visitor;
42 use crate::hir::map::{definitions::DisambiguatedDefPathData, DefPathData};
43 use syntax::util::lev_distance::find_best_match_for_name;
44 use syntax::visit as ast_visit;
46 /// Information about the registered lints.
48 /// This is basically the subset of `Context` that we can
49 /// build early in the compile pipeline.
50 pub struct LintStore {
51 /// Registered lints. The bool is true if the lint was
52 /// added by a plugin.
53 lints: Vec<(&'static Lint, bool)>,
55 /// Trait objects for each lint pass.
56 /// This is only `None` while performing a lint pass.
57 pre_expansion_passes: Option<Vec<EarlyLintPassObject>>,
58 early_passes: Option<Vec<EarlyLintPassObject>>,
59 late_passes: Lock<Option<Vec<LateLintPassObject>>>,
60 late_module_passes: Vec<LateLintPassObject>,
62 /// Lints indexed by name.
63 by_name: FxHashMap<String, TargetLint>,
65 /// Map of registered lint groups to what lints they expand to.
66 lint_groups: FxHashMap<&'static str, LintGroup>,
68 /// Extra info for future incompatibility lints, describing the
69 /// issue or RFC that caused the incompatibility.
70 future_incompatible: FxHashMap<LintId, FutureIncompatibleInfo>,
73 /// Lints that are buffered up early on in the `Session` before the
74 /// `LintLevels` is calculated
75 #[derive(PartialEq, RustcEncodable, RustcDecodable, Debug)]
76 pub struct BufferedEarlyLint {
78 pub ast_id: ast::NodeId,
81 pub diagnostic: BuiltinLintDiagnostics,
84 /// Extra information for a future incompatibility lint. See the call
85 /// to `register_future_incompatible` in `librustc_lint/lib.rs` for
87 pub struct FutureIncompatibleInfo {
89 /// e.g., a URL for an issue/PR/RFC or error code
90 pub reference: &'static str,
91 /// If this is an edition fixing lint, the edition in which
92 /// this lint becomes obsolete
93 pub edition: Option<edition::Edition>,
96 /// The target of the `by_name` map, which accounts for renaming/deprecation.
98 /// A direct lint target
101 /// Temporary renaming, used for easing migration pain; see #16545
102 Renamed(String, LintId),
104 /// Lint with this name existed previously, but has been removed/deprecated.
105 /// The string argument is the reason for removal.
109 pub enum FindLintError {
116 /// Whether deprecation warnings should be suppressed for this alias.
121 lint_ids: Vec<LintId>,
123 depr: Option<LintAlias>,
126 pub enum CheckLintNameResult<'a> {
128 /// Lint doesn't exist. Potentially contains a suggestion for a correct lint name.
129 NoLint(Option<Symbol>),
130 /// The lint is either renamed or removed. This is the warning
131 /// message, and an optional new name (`None` if removed).
132 Warning(String, Option<String>),
133 /// The lint is from a tool. If the Option is None, then either
134 /// the lint does not exist in the tool or the code was not
135 /// compiled with the tool and therefore the lint was never
136 /// added to the `LintStore`. Otherwise the `LintId` will be
137 /// returned as if it where a rustc lint.
138 Tool(Result<&'a [LintId], (Option<&'a [LintId]>, String)>),
142 pub fn new() -> LintStore {
145 pre_expansion_passes: Some(vec![]),
146 early_passes: Some(vec![]),
147 late_passes: Lock::new(Some(vec![])),
148 late_module_passes: vec![],
149 by_name: Default::default(),
150 future_incompatible: Default::default(),
151 lint_groups: Default::default(),
155 pub fn get_lints<'t>(&'t self) -> &'t [(&'static Lint, bool)] {
159 pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
160 self.lint_groups.iter()
161 .filter(|(_, LintGroup { depr, .. })| {
162 // Don't display deprecated lint groups.
165 .map(|(k, LintGroup { lint_ids, from_plugin, .. })| {
166 (*k, lint_ids.clone(), *from_plugin)
171 pub fn register_early_pass(&mut self,
172 sess: Option<&Session>,
175 pass: EarlyLintPassObject) {
176 self.push_pass(sess, from_plugin, &pass);
178 self.early_passes.as_mut().unwrap().push(pass);
182 pub fn register_pre_expansion_pass(
184 sess: Option<&Session>,
187 pass: EarlyLintPassObject,
189 self.push_pass(sess, from_plugin, &pass);
191 self.pre_expansion_passes.as_mut().unwrap().push(pass);
195 pub fn register_late_pass(&mut self,
196 sess: Option<&Session>,
200 pass: LateLintPassObject) {
201 self.push_pass(sess, from_plugin, &pass);
204 self.late_module_passes.push(pass);
206 self.late_passes.lock().as_mut().unwrap().push(pass);
211 // Helper method for register_early/late_pass
212 fn push_pass<P: LintPass + ?Sized + 'static>(&mut self,
213 sess: Option<&Session>,
216 for lint in pass.get_lints() {
217 self.lints.push((lint, from_plugin));
219 let id = LintId::of(lint);
220 if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
221 let msg = format!("duplicate specification of lint {}", lint.name_lower());
222 match (sess, from_plugin) {
223 // We load builtin lints first, so a duplicate is a compiler bug.
224 // Use early_error when handling -W help with no crate.
225 (None, _) => early_error(config::ErrorOutputType::default(), &msg[..]),
226 (Some(_), false) => bug!("{}", msg),
228 // A duplicate name from a plugin is a user error.
229 (Some(sess), true) => sess.err(&msg[..]),
235 pub fn register_future_incompatible(&mut self,
236 sess: Option<&Session>,
237 lints: Vec<FutureIncompatibleInfo>) {
239 for edition in edition::ALL_EDITIONS {
240 let lints = lints.iter().filter(|f| f.edition == Some(*edition)).map(|f| f.id)
241 .collect::<Vec<_>>();
242 if !lints.is_empty() {
243 self.register_group(sess, false, edition.lint_name(), None, lints)
247 let mut future_incompatible = Vec::with_capacity(lints.len());
249 future_incompatible.push(lint.id);
250 self.future_incompatible.insert(lint.id, lint);
256 "future_incompatible",
262 pub fn future_incompatible(&self, id: LintId) -> Option<&FutureIncompatibleInfo> {
263 self.future_incompatible.get(&id)
266 pub fn register_group_alias(
268 lint_name: &'static str,
271 self.lint_groups.insert(alias, LintGroup {
274 depr: Some(LintAlias { name: lint_name, silent: true }),
278 pub fn register_group(
280 sess: Option<&Session>,
283 deprecated_name: Option<&'static str>,
288 .insert(name, LintGroup {
294 if let Some(deprecated) = deprecated_name {
295 self.lint_groups.insert(deprecated, LintGroup {
298 depr: Some(LintAlias { name, silent: false }),
303 let msg = format!("duplicate specification of lint group {}", name);
304 match (sess, from_plugin) {
305 // We load builtin lints first, so a duplicate is a compiler bug.
306 // Use early_error when handling -W help with no crate.
307 (None, _) => early_error(config::ErrorOutputType::default(), &msg[..]),
308 (Some(_), false) => bug!("{}", msg),
310 // A duplicate name from a plugin is a user error.
311 (Some(sess), true) => sess.err(&msg[..]),
316 pub fn register_renamed(&mut self, old_name: &str, new_name: &str) {
317 let target = match self.by_name.get(new_name) {
318 Some(&Id(lint_id)) => lint_id.clone(),
319 _ => bug!("invalid lint renaming of {} to {}", old_name, new_name)
321 self.by_name.insert(old_name.to_string(), Renamed(new_name.to_string(), target));
324 pub fn register_removed(&mut self, name: &str, reason: &str) {
325 self.by_name.insert(name.into(), Removed(reason.into()));
328 pub fn find_lints(&self, mut lint_name: &str) -> Result<Vec<LintId>, FindLintError> {
329 match self.by_name.get(lint_name) {
330 Some(&Id(lint_id)) => Ok(vec![lint_id]),
331 Some(&Renamed(_, lint_id)) => {
334 Some(&Removed(_)) => {
335 Err(FindLintError::Removed)
339 return match self.lint_groups.get(lint_name) {
340 Some(LintGroup {lint_ids, depr, .. }) => {
341 if let Some(LintAlias { name, .. }) = depr {
347 None => Err(FindLintError::Removed)
354 /// Checks the validity of lint names derived from the command line
355 pub fn check_lint_name_cmdline(&self,
359 let db = match self.check_lint_name(lint_name, None) {
360 CheckLintNameResult::Ok(_) => None,
361 CheckLintNameResult::Warning(ref msg, _) => {
362 Some(sess.struct_warn(msg))
364 CheckLintNameResult::NoLint(suggestion) => {
365 let mut err = struct_err!(sess, E0602, "unknown lint: `{}`", lint_name);
367 if let Some(suggestion) = suggestion {
368 err.help(&format!("did you mean: `{}`", suggestion));
373 CheckLintNameResult::Tool(result) => match result {
374 Err((Some(_), new_name)) => Some(sess.struct_warn(&format!(
375 "lint name `{}` is deprecated \
376 and does not have an effect anymore. \
384 if let Some(mut db) = db {
385 let msg = format!("requested on the command line with `{} {}`",
387 Level::Allow => "-A",
390 Level::Forbid => "-F",
398 /// Checks the name of a lint for its existence, and whether it was
399 /// renamed or removed. Generates a DiagnosticBuilder containing a
400 /// warning for renamed and removed lints. This is over both lint
401 /// names from attributes and those passed on the command line. Since
402 /// it emits non-fatal warnings and there are *two* lint passes that
403 /// inspect attributes, this is only run from the late pass to avoid
404 /// printing duplicate warnings.
405 pub fn check_lint_name(
408 tool_name: Option<LocalInternedString>,
409 ) -> CheckLintNameResult<'_> {
410 let complete_name = if let Some(tool_name) = tool_name {
411 format!("{}::{}", tool_name, lint_name)
413 lint_name.to_string()
415 // If the lint was scoped with `tool::` check if the tool lint exists
416 if let Some(_) = tool_name {
417 match self.by_name.get(&complete_name) {
418 None => match self.lint_groups.get(&*complete_name) {
419 None => return CheckLintNameResult::Tool(Err((None, String::new()))),
420 Some(LintGroup { lint_ids, .. }) => {
421 return CheckLintNameResult::Tool(Ok(&lint_ids));
424 Some(&Id(ref id)) => return CheckLintNameResult::Tool(Ok(slice::from_ref(id))),
425 // If the lint was registered as removed or renamed by the lint tool, we don't need
426 // to treat tool_lints and rustc lints different and can use the code below.
430 match self.by_name.get(&complete_name) {
431 Some(&Renamed(ref new_name, _)) => CheckLintNameResult::Warning(
433 "lint `{}` has been renamed to `{}`",
434 complete_name, new_name
436 Some(new_name.to_owned()),
438 Some(&Removed(ref reason)) => CheckLintNameResult::Warning(
439 format!("lint `{}` has been removed: `{}`", complete_name, reason),
442 None => match self.lint_groups.get(&*complete_name) {
443 // If neither the lint, nor the lint group exists check if there is a `clippy::`
444 // variant of this lint
445 None => self.check_tool_name_for_backwards_compat(&complete_name, "clippy"),
446 Some(LintGroup { lint_ids, depr, .. }) => {
447 // Check if the lint group name is deprecated
448 if let Some(LintAlias { name, silent }) = depr {
449 let LintGroup { lint_ids, .. } = self.lint_groups.get(name).unwrap();
451 CheckLintNameResult::Ok(&lint_ids)
453 CheckLintNameResult::Tool(Err((
459 CheckLintNameResult::Ok(&lint_ids)
462 Some(&Id(ref id)) => CheckLintNameResult::Ok(slice::from_ref(id)),
466 fn check_tool_name_for_backwards_compat(
470 ) -> CheckLintNameResult<'_> {
471 let complete_name = format!("{}::{}", tool_name, lint_name);
472 match self.by_name.get(&complete_name) {
473 None => match self.lint_groups.get(&*complete_name) {
474 // Now we are sure, that this lint exists nowhere
476 let symbols = self.by_name.keys()
477 .map(|name| Symbol::intern(&name))
478 .collect::<Vec<_>>();
481 find_best_match_for_name(symbols.iter(), &lint_name.to_lowercase(), None);
483 CheckLintNameResult::NoLint(suggestion)
485 Some(LintGroup { lint_ids, depr, .. }) => {
486 // Reaching this would be weird, but let's cover this case anyway
487 if let Some(LintAlias { name, silent }) = depr {
488 let LintGroup { lint_ids, .. } = self.lint_groups.get(name).unwrap();
490 CheckLintNameResult::Tool(Err((Some(&lint_ids), complete_name)))
492 CheckLintNameResult::Tool(Err((
498 CheckLintNameResult::Tool(Err((Some(&lint_ids), complete_name)))
501 Some(&Id(ref id)) => {
502 CheckLintNameResult::Tool(Err((Some(slice::from_ref(id)), complete_name)))
504 _ => CheckLintNameResult::NoLint(None),
509 /// Context for lint checking after type checking.
510 pub struct LateContext<'a, 'tcx: 'a> {
511 /// Type context we're checking in.
512 pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
514 /// Side-tables for the body we are in.
515 // FIXME: Make this lazy to avoid running the TypeckTables query?
516 pub tables: &'a ty::TypeckTables<'tcx>,
518 /// Parameter environment for the item we are in.
519 pub param_env: ty::ParamEnv<'tcx>,
521 /// Items accessible from the crate being checked.
522 pub access_levels: &'a AccessLevels,
524 /// The store of registered lints and the lint levels.
525 lint_store: ReadGuard<'a, LintStore>,
527 last_node_with_lint_attrs: hir::HirId,
529 /// Generic type parameters in scope for the item we are in.
530 pub generics: Option<&'tcx hir::Generics>,
532 /// We are only looking at one module
536 pub struct LateContextAndPass<'a, 'tcx: 'a, T: LateLintPass<'a, 'tcx>> {
537 context: LateContext<'a, 'tcx>,
541 /// Context for lint checking of the AST, after expansion, before lowering to
543 pub struct EarlyContext<'a> {
544 /// Type context we're checking in.
545 pub sess: &'a Session,
547 /// The crate being checked.
548 pub krate: &'a ast::Crate,
550 builder: LintLevelsBuilder<'a>,
552 /// The store of registered lints and the lint levels.
553 lint_store: ReadGuard<'a, LintStore>,
555 buffered: LintBuffer,
558 pub struct EarlyContextAndPass<'a, T: EarlyLintPass> {
559 context: EarlyContext<'a>,
563 pub trait LintPassObject: Sized {}
565 impl LintPassObject for EarlyLintPassObject {}
567 impl LintPassObject for LateLintPassObject {}
569 pub trait LintContext<'tcx>: Sized {
570 type PassObject: LintPassObject;
572 fn sess(&self) -> &Session;
573 fn lints(&self) -> &LintStore;
575 fn lookup_and_emit<S: Into<MultiSpan>>(&self,
579 self.lookup(lint, span, msg).emit();
582 fn lookup_and_emit_with_diagnostics<S: Into<MultiSpan>>(&self,
586 diagnostic: BuiltinLintDiagnostics) {
587 let mut db = self.lookup(lint, span, msg);
588 diagnostic.run(self.sess(), &mut db);
592 fn lookup<S: Into<MultiSpan>>(&self,
596 -> DiagnosticBuilder<'_>;
598 /// Emit a lint at the appropriate level, for a particular span.
599 fn span_lint<S: Into<MultiSpan>>(&self, lint: &'static Lint, span: S, msg: &str) {
600 self.lookup_and_emit(lint, Some(span), msg);
603 fn struct_span_lint<S: Into<MultiSpan>>(&self,
607 -> DiagnosticBuilder<'_> {
608 self.lookup(lint, Some(span), msg)
611 /// Emit a lint and note at the appropriate level, for a particular span.
612 fn span_lint_note(&self, lint: &'static Lint, span: Span, msg: &str,
613 note_span: Span, note: &str) {
614 let mut err = self.lookup(lint, Some(span), msg);
615 if note_span == span {
618 err.span_note(note_span, note);
623 /// Emit a lint and help at the appropriate level, for a particular span.
624 fn span_lint_help(&self, lint: &'static Lint, span: Span,
625 msg: &str, help: &str) {
626 let mut err = self.lookup(lint, Some(span), msg);
627 self.span_lint(lint, span, msg);
628 err.span_help(span, help);
632 /// Emit a lint at the appropriate level, with no associated span.
633 fn lint(&self, lint: &'static Lint, msg: &str) {
634 self.lookup_and_emit(lint, None as Option<Span>, msg);
639 impl<'a> EarlyContext<'a> {
642 krate: &'a ast::Crate,
643 buffered: LintBuffer,
644 ) -> EarlyContext<'a> {
648 lint_store: sess.lint_store.borrow(),
649 builder: LintLevelSets::builder(sess),
655 macro_rules! lint_callback { ($cx:expr, $f:ident, $($args:expr),*) => ({
656 $cx.pass.$f(&$cx.context, $($args),*);
659 macro_rules! run_early_pass { ($cx:expr, $f:ident, $($args:expr),*) => ({
660 $cx.pass.$f(&$cx.context, $($args),*);
663 impl<'a, T: EarlyLintPass> EarlyContextAndPass<'a, T> {
664 fn check_id(&mut self, id: ast::NodeId) {
665 for early_lint in self.context.buffered.take(id) {
666 self.context.lookup_and_emit_with_diagnostics(
667 early_lint.lint_id.lint,
668 Some(early_lint.span.clone()),
670 early_lint.diagnostic
675 /// Merge the lints specified by any lint attributes into the
676 /// current lint context, call the provided function, then reset the
677 /// lints in effect to their previous state.
678 fn with_lint_attrs<F>(&mut self,
680 attrs: &'a [ast::Attribute],
682 where F: FnOnce(&mut Self)
684 let push = self.context.builder.push(attrs);
686 self.enter_attrs(attrs);
688 self.exit_attrs(attrs);
689 self.context.builder.pop(push);
692 fn enter_attrs(&mut self, attrs: &'a [ast::Attribute]) {
693 debug!("early context: enter_attrs({:?})", attrs);
694 run_early_pass!(self, enter_lint_attrs, attrs);
697 fn exit_attrs(&mut self, attrs: &'a [ast::Attribute]) {
698 debug!("early context: exit_attrs({:?})", attrs);
699 run_early_pass!(self, exit_lint_attrs, attrs);
703 impl<'a, 'tcx> LintContext<'tcx> for LateContext<'a, 'tcx> {
704 type PassObject = LateLintPassObject;
706 /// Gets the overall compiler `Session` object.
707 fn sess(&self) -> &Session {
711 fn lints(&self) -> &LintStore {
715 fn lookup<S: Into<MultiSpan>>(&self,
719 -> DiagnosticBuilder<'_> {
720 let hir_id = self.last_node_with_lint_attrs;
723 Some(s) => self.tcx.struct_span_lint_hir(lint, hir_id, s, msg),
725 self.tcx.struct_lint_node(lint, hir_id, msg)
731 impl<'a> LintContext<'a> for EarlyContext<'a> {
732 type PassObject = EarlyLintPassObject;
734 /// Gets the overall compiler `Session` object.
735 fn sess(&self) -> &Session {
739 fn lints(&self) -> &LintStore {
743 fn lookup<S: Into<MultiSpan>>(&self,
747 -> DiagnosticBuilder<'_> {
748 self.builder.struct_lint(lint, span.map(|s| s.into()), msg)
752 impl<'a, 'tcx> LateContext<'a, 'tcx> {
753 pub fn current_lint_root(&self) -> hir::HirId {
754 self.last_node_with_lint_attrs
757 /// Check if a `DefId`'s path matches the given absolute type path usage.
760 /// ```rust,ignore (no `cx` or `def_id` available)
761 /// if cx.match_def_path(def_id, &["core", "option", "Option"]) {
762 /// // The given `def_id` is that of an `Option` type
765 // Uplifted from rust-lang/rust-clippy
766 pub fn match_def_path(&self, def_id: DefId, path: &[&str]) -> bool {
767 let names = self.get_def_path(def_id);
769 names.len() == path.len() && names.into_iter().zip(path.iter()).all(|(a, &b)| *a == *b)
772 /// Gets the absolute path of `def_id` as a vector of `&str`.
775 /// ```rust,ignore (no `cx` or `def_id` available)
776 /// let def_path = cx.get_def_path(def_id);
777 /// if let &["core", "option", "Option"] = &def_path[..] {
778 /// // The given `def_id` is that of an `Option` type
781 // Uplifted from rust-lang/rust-clippy
782 pub fn get_def_path(&self, def_id: DefId) -> Vec<LocalInternedString> {
783 pub struct AbsolutePathPrinter<'a, 'tcx> {
784 pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
787 impl<'tcx> Printer<'tcx, 'tcx> for AbsolutePathPrinter<'_, 'tcx> {
790 type Path = Vec<LocalInternedString>;
793 type DynExistential = ();
795 fn tcx<'a>(&'a self) -> TyCtxt<'a, 'tcx, 'tcx> {
799 fn print_region(self, _region: ty::Region<'_>) -> Result<Self::Region, Self::Error> {
803 fn print_type(self, _ty: Ty<'tcx>) -> Result<Self::Type, Self::Error> {
807 fn print_dyn_existential(
809 _predicates: &'tcx ty::List<ty::ExistentialPredicate<'tcx>>,
810 ) -> Result<Self::DynExistential, Self::Error> {
814 fn path_crate(self, cnum: CrateNum) -> Result<Self::Path, Self::Error> {
815 Ok(vec![self.tcx.original_crate_name(cnum).as_str()])
821 trait_ref: Option<ty::TraitRef<'tcx>>,
822 ) -> Result<Self::Path, Self::Error> {
823 if trait_ref.is_none() {
824 if let ty::Adt(def, substs) = self_ty.sty {
825 return self.print_def_path(def.did, substs);
829 // This shouldn't ever be needed, but just in case:
830 Ok(vec![match trait_ref {
831 Some(trait_ref) => Symbol::intern(&format!("{:?}", trait_ref)).as_str(),
832 None => Symbol::intern(&format!("<{}>", self_ty)).as_str(),
838 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
839 _disambiguated_data: &DisambiguatedDefPathData,
841 trait_ref: Option<ty::TraitRef<'tcx>>,
842 ) -> Result<Self::Path, Self::Error> {
843 let mut path = print_prefix(self)?;
845 // This shouldn't ever be needed, but just in case:
846 path.push(match trait_ref {
848 Symbol::intern(&format!("<impl {} for {}>", trait_ref, self_ty)).as_str()
850 None => Symbol::intern(&format!("<impl {}>", self_ty)).as_str(),
858 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
859 disambiguated_data: &DisambiguatedDefPathData,
860 ) -> Result<Self::Path, Self::Error> {
861 let mut path = print_prefix(self)?;
863 // Skip `::{{constructor}}` on tuple/unit structs.
864 match disambiguated_data.data {
865 DefPathData::Ctor => return Ok(path),
869 path.push(disambiguated_data.data.as_interned_str().as_str());
873 fn path_generic_args(
875 print_prefix: impl FnOnce(Self) -> Result<Self::Path, Self::Error>,
876 _args: &[Kind<'tcx>],
877 ) -> Result<Self::Path, Self::Error> {
882 AbsolutePathPrinter { tcx: self.tcx }
883 .print_def_path(def_id, &[])
888 impl<'a, 'tcx> LayoutOf for LateContext<'a, 'tcx> {
890 type TyLayout = Result<TyLayout<'tcx>, LayoutError<'tcx>>;
892 fn layout_of(&self, ty: Ty<'tcx>) -> Self::TyLayout {
893 self.tcx.layout_of(self.param_env.and(ty))
897 impl<'a, 'tcx, T: LateLintPass<'a, 'tcx>> LateContextAndPass<'a, 'tcx, T> {
898 /// Merge the lints specified by any lint attributes into the
899 /// current lint context, call the provided function, then reset the
900 /// lints in effect to their previous state.
901 fn with_lint_attrs<F>(&mut self,
903 attrs: &'tcx [ast::Attribute],
905 where F: FnOnce(&mut Self)
907 let prev = self.context.last_node_with_lint_attrs;
908 self.context.last_node_with_lint_attrs = id;
909 self.enter_attrs(attrs);
911 self.exit_attrs(attrs);
912 self.context.last_node_with_lint_attrs = prev;
915 fn with_param_env<F>(&mut self, id: hir::HirId, f: F)
916 where F: FnOnce(&mut Self),
918 let old_param_env = self.context.param_env;
919 self.context.param_env = self.context.tcx.param_env(
920 self.context.tcx.hir().local_def_id_from_hir_id(id)
923 self.context.param_env = old_param_env;
926 fn process_mod(&mut self, m: &'tcx hir::Mod, s: Span, n: hir::HirId) {
927 lint_callback!(self, check_mod, m, s, n);
928 hir_visit::walk_mod(self, m, n);
929 lint_callback!(self, check_mod_post, m, s, n);
932 fn enter_attrs(&mut self, attrs: &'tcx [ast::Attribute]) {
933 debug!("late context: enter_attrs({:?})", attrs);
934 lint_callback!(self, enter_lint_attrs, attrs);
937 fn exit_attrs(&mut self, attrs: &'tcx [ast::Attribute]) {
938 debug!("late context: exit_attrs({:?})", attrs);
939 lint_callback!(self, exit_lint_attrs, attrs);
943 impl<'a, 'tcx, T: LateLintPass<'a, 'tcx>> hir_visit::Visitor<'tcx>
944 for LateContextAndPass<'a, 'tcx, T> {
945 /// Because lints are scoped lexically, we want to walk nested
946 /// items in the context of the outer item, so enable
948 fn nested_visit_map<'this>(&'this mut self) -> hir_visit::NestedVisitorMap<'this, 'tcx> {
949 hir_visit::NestedVisitorMap::All(&self.context.tcx.hir())
952 fn visit_nested_body(&mut self, body: hir::BodyId) {
953 let old_tables = self.context.tables;
954 self.context.tables = self.context.tcx.body_tables(body);
955 let body = self.context.tcx.hir().body(body);
956 self.visit_body(body);
957 self.context.tables = old_tables;
960 fn visit_body(&mut self, body: &'tcx hir::Body) {
961 lint_callback!(self, check_body, body);
962 hir_visit::walk_body(self, body);
963 lint_callback!(self, check_body_post, body);
966 fn visit_item(&mut self, it: &'tcx hir::Item) {
967 let generics = self.context.generics.take();
968 self.context.generics = it.node.generics();
969 self.with_lint_attrs(it.hir_id, &it.attrs, |cx| {
970 cx.with_param_env(it.hir_id, |cx| {
971 lint_callback!(cx, check_item, it);
972 hir_visit::walk_item(cx, it);
973 lint_callback!(cx, check_item_post, it);
976 self.context.generics = generics;
979 fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem) {
980 self.with_lint_attrs(it.hir_id, &it.attrs, |cx| {
981 cx.with_param_env(it.hir_id, |cx| {
982 lint_callback!(cx, check_foreign_item, it);
983 hir_visit::walk_foreign_item(cx, it);
984 lint_callback!(cx, check_foreign_item_post, it);
989 fn visit_pat(&mut self, p: &'tcx hir::Pat) {
990 lint_callback!(self, check_pat, p);
991 hir_visit::walk_pat(self, p);
994 fn visit_expr(&mut self, e: &'tcx hir::Expr) {
995 self.with_lint_attrs(e.hir_id, &e.attrs, |cx| {
996 lint_callback!(cx, check_expr, e);
997 hir_visit::walk_expr(cx, e);
998 lint_callback!(cx, check_expr_post, e);
1002 fn visit_stmt(&mut self, s: &'tcx hir::Stmt) {
1003 // statement attributes are actually just attributes on one of
1007 // so we keep track of lint levels there
1008 lint_callback!(self, check_stmt, s);
1009 hir_visit::walk_stmt(self, s);
1012 fn visit_fn(&mut self, fk: hir_visit::FnKind<'tcx>, decl: &'tcx hir::FnDecl,
1013 body_id: hir::BodyId, span: Span, id: hir::HirId) {
1014 // Wrap in tables here, not just in visit_nested_body,
1015 // in order for `check_fn` to be able to use them.
1016 let old_tables = self.context.tables;
1017 self.context.tables = self.context.tcx.body_tables(body_id);
1018 let body = self.context.tcx.hir().body(body_id);
1019 lint_callback!(self, check_fn, fk, decl, body, span, id);
1020 hir_visit::walk_fn(self, fk, decl, body_id, span, id);
1021 lint_callback!(self, check_fn_post, fk, decl, body, span, id);
1022 self.context.tables = old_tables;
1025 fn visit_variant_data(&mut self,
1026 s: &'tcx hir::VariantData,
1028 g: &'tcx hir::Generics,
1029 item_id: hir::HirId,
1031 lint_callback!(self, check_struct_def, s, name, g, item_id);
1032 hir_visit::walk_struct_def(self, s);
1033 lint_callback!(self, check_struct_def_post, s, name, g, item_id);
1036 fn visit_struct_field(&mut self, s: &'tcx hir::StructField) {
1037 self.with_lint_attrs(s.hir_id, &s.attrs, |cx| {
1038 lint_callback!(cx, check_struct_field, s);
1039 hir_visit::walk_struct_field(cx, s);
1043 fn visit_variant(&mut self,
1044 v: &'tcx hir::Variant,
1045 g: &'tcx hir::Generics,
1046 item_id: hir::HirId) {
1047 self.with_lint_attrs(v.node.id, &v.node.attrs, |cx| {
1048 lint_callback!(cx, check_variant, v, g);
1049 hir_visit::walk_variant(cx, v, g, item_id);
1050 lint_callback!(cx, check_variant_post, v, g);
1054 fn visit_ty(&mut self, t: &'tcx hir::Ty) {
1055 lint_callback!(self, check_ty, t);
1056 hir_visit::walk_ty(self, t);
1059 fn visit_name(&mut self, sp: Span, name: ast::Name) {
1060 lint_callback!(self, check_name, sp, name);
1063 fn visit_mod(&mut self, m: &'tcx hir::Mod, s: Span, n: hir::HirId) {
1064 if !self.context.only_module {
1065 self.process_mod(m, s, n);
1069 fn visit_local(&mut self, l: &'tcx hir::Local) {
1070 self.with_lint_attrs(l.hir_id, &l.attrs, |cx| {
1071 lint_callback!(cx, check_local, l);
1072 hir_visit::walk_local(cx, l);
1076 fn visit_block(&mut self, b: &'tcx hir::Block) {
1077 lint_callback!(self, check_block, b);
1078 hir_visit::walk_block(self, b);
1079 lint_callback!(self, check_block_post, b);
1082 fn visit_arm(&mut self, a: &'tcx hir::Arm) {
1083 lint_callback!(self, check_arm, a);
1084 hir_visit::walk_arm(self, a);
1087 fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam) {
1088 lint_callback!(self, check_generic_param, p);
1089 hir_visit::walk_generic_param(self, p);
1092 fn visit_generics(&mut self, g: &'tcx hir::Generics) {
1093 lint_callback!(self, check_generics, g);
1094 hir_visit::walk_generics(self, g);
1097 fn visit_where_predicate(&mut self, p: &'tcx hir::WherePredicate) {
1098 lint_callback!(self, check_where_predicate, p);
1099 hir_visit::walk_where_predicate(self, p);
1102 fn visit_poly_trait_ref(&mut self, t: &'tcx hir::PolyTraitRef,
1103 m: hir::TraitBoundModifier) {
1104 lint_callback!(self, check_poly_trait_ref, t, m);
1105 hir_visit::walk_poly_trait_ref(self, t, m);
1108 fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) {
1109 let generics = self.context.generics.take();
1110 self.context.generics = Some(&trait_item.generics);
1111 self.with_lint_attrs(trait_item.hir_id, &trait_item.attrs, |cx| {
1112 cx.with_param_env(trait_item.hir_id, |cx| {
1113 lint_callback!(cx, check_trait_item, trait_item);
1114 hir_visit::walk_trait_item(cx, trait_item);
1115 lint_callback!(cx, check_trait_item_post, trait_item);
1118 self.context.generics = generics;
1121 fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
1122 let generics = self.context.generics.take();
1123 self.context.generics = Some(&impl_item.generics);
1124 self.with_lint_attrs(impl_item.hir_id, &impl_item.attrs, |cx| {
1125 cx.with_param_env(impl_item.hir_id, |cx| {
1126 lint_callback!(cx, check_impl_item, impl_item);
1127 hir_visit::walk_impl_item(cx, impl_item);
1128 lint_callback!(cx, check_impl_item_post, impl_item);
1131 self.context.generics = generics;
1134 fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
1135 lint_callback!(self, check_lifetime, lt);
1136 hir_visit::walk_lifetime(self, lt);
1139 fn visit_path(&mut self, p: &'tcx hir::Path, id: hir::HirId) {
1140 lint_callback!(self, check_path, p, id);
1141 hir_visit::walk_path(self, p);
1144 fn visit_attribute(&mut self, attr: &'tcx ast::Attribute) {
1145 lint_callback!(self, check_attribute, attr);
1149 impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T> {
1150 fn visit_item(&mut self, it: &'a ast::Item) {
1151 self.with_lint_attrs(it.id, &it.attrs, |cx| {
1152 run_early_pass!(cx, check_item, it);
1153 ast_visit::walk_item(cx, it);
1154 run_early_pass!(cx, check_item_post, it);
1158 fn visit_foreign_item(&mut self, it: &'a ast::ForeignItem) {
1159 self.with_lint_attrs(it.id, &it.attrs, |cx| {
1160 run_early_pass!(cx, check_foreign_item, it);
1161 ast_visit::walk_foreign_item(cx, it);
1162 run_early_pass!(cx, check_foreign_item_post, it);
1166 fn visit_pat(&mut self, p: &'a ast::Pat) {
1167 run_early_pass!(self, check_pat, p);
1168 self.check_id(p.id);
1169 ast_visit::walk_pat(self, p);
1170 run_early_pass!(self, check_pat_post, p);
1173 fn visit_expr(&mut self, e: &'a ast::Expr) {
1174 self.with_lint_attrs(e.id, &e.attrs, |cx| {
1175 run_early_pass!(cx, check_expr, e);
1176 ast_visit::walk_expr(cx, e);
1180 fn visit_stmt(&mut self, s: &'a ast::Stmt) {
1181 run_early_pass!(self, check_stmt, s);
1182 self.check_id(s.id);
1183 ast_visit::walk_stmt(self, s);
1186 fn visit_fn(&mut self, fk: ast_visit::FnKind<'a>, decl: &'a ast::FnDecl,
1187 span: Span, id: ast::NodeId) {
1188 run_early_pass!(self, check_fn, fk, decl, span, id);
1190 ast_visit::walk_fn(self, fk, decl, span);
1191 run_early_pass!(self, check_fn_post, fk, decl, span, id);
1194 fn visit_variant_data(&mut self,
1195 s: &'a ast::VariantData,
1197 g: &'a ast::Generics,
1198 item_id: ast::NodeId,
1200 run_early_pass!(self, check_struct_def, s, ident, g, item_id);
1201 if let Some(ctor_hir_id) = s.ctor_id() {
1202 self.check_id(ctor_hir_id);
1204 ast_visit::walk_struct_def(self, s);
1205 run_early_pass!(self, check_struct_def_post, s, ident, g, item_id);
1208 fn visit_struct_field(&mut self, s: &'a ast::StructField) {
1209 self.with_lint_attrs(s.id, &s.attrs, |cx| {
1210 run_early_pass!(cx, check_struct_field, s);
1211 ast_visit::walk_struct_field(cx, s);
1215 fn visit_variant(&mut self, v: &'a ast::Variant, g: &'a ast::Generics, item_id: ast::NodeId) {
1216 self.with_lint_attrs(item_id, &v.node.attrs, |cx| {
1217 run_early_pass!(cx, check_variant, v, g);
1218 ast_visit::walk_variant(cx, v, g, item_id);
1219 run_early_pass!(cx, check_variant_post, v, g);
1223 fn visit_ty(&mut self, t: &'a ast::Ty) {
1224 run_early_pass!(self, check_ty, t);
1225 self.check_id(t.id);
1226 ast_visit::walk_ty(self, t);
1229 fn visit_ident(&mut self, ident: ast::Ident) {
1230 run_early_pass!(self, check_ident, ident);
1233 fn visit_mod(&mut self, m: &'a ast::Mod, s: Span, _a: &[ast::Attribute], n: ast::NodeId) {
1234 run_early_pass!(self, check_mod, m, s, n);
1236 ast_visit::walk_mod(self, m);
1237 run_early_pass!(self, check_mod_post, m, s, n);
1240 fn visit_local(&mut self, l: &'a ast::Local) {
1241 self.with_lint_attrs(l.id, &l.attrs, |cx| {
1242 run_early_pass!(cx, check_local, l);
1243 ast_visit::walk_local(cx, l);
1247 fn visit_block(&mut self, b: &'a ast::Block) {
1248 run_early_pass!(self, check_block, b);
1249 self.check_id(b.id);
1250 ast_visit::walk_block(self, b);
1251 run_early_pass!(self, check_block_post, b);
1254 fn visit_arm(&mut self, a: &'a ast::Arm) {
1255 run_early_pass!(self, check_arm, a);
1256 ast_visit::walk_arm(self, a);
1259 fn visit_expr_post(&mut self, e: &'a ast::Expr) {
1260 run_early_pass!(self, check_expr_post, e);
1263 fn visit_generic_param(&mut self, param: &'a ast::GenericParam) {
1264 run_early_pass!(self, check_generic_param, param);
1265 ast_visit::walk_generic_param(self, param);
1268 fn visit_generics(&mut self, g: &'a ast::Generics) {
1269 run_early_pass!(self, check_generics, g);
1270 ast_visit::walk_generics(self, g);
1273 fn visit_where_predicate(&mut self, p: &'a ast::WherePredicate) {
1274 run_early_pass!(self, check_where_predicate, p);
1275 ast_visit::walk_where_predicate(self, p);
1278 fn visit_poly_trait_ref(&mut self, t: &'a ast::PolyTraitRef, m: &'a ast::TraitBoundModifier) {
1279 run_early_pass!(self, check_poly_trait_ref, t, m);
1280 ast_visit::walk_poly_trait_ref(self, t, m);
1283 fn visit_trait_item(&mut self, trait_item: &'a ast::TraitItem) {
1284 self.with_lint_attrs(trait_item.id, &trait_item.attrs, |cx| {
1285 run_early_pass!(cx, check_trait_item, trait_item);
1286 ast_visit::walk_trait_item(cx, trait_item);
1287 run_early_pass!(cx, check_trait_item_post, trait_item);
1291 fn visit_impl_item(&mut self, impl_item: &'a ast::ImplItem) {
1292 self.with_lint_attrs(impl_item.id, &impl_item.attrs, |cx| {
1293 run_early_pass!(cx, check_impl_item, impl_item);
1294 ast_visit::walk_impl_item(cx, impl_item);
1295 run_early_pass!(cx, check_impl_item_post, impl_item);
1299 fn visit_lifetime(&mut self, lt: &'a ast::Lifetime) {
1300 run_early_pass!(self, check_lifetime, lt);
1301 self.check_id(lt.id);
1304 fn visit_path(&mut self, p: &'a ast::Path, id: ast::NodeId) {
1305 run_early_pass!(self, check_path, p, id);
1307 ast_visit::walk_path(self, p);
1310 fn visit_attribute(&mut self, attr: &'a ast::Attribute) {
1311 run_early_pass!(self, check_attribute, attr);
1314 fn visit_mac_def(&mut self, mac: &'a ast::MacroDef, id: ast::NodeId) {
1315 run_early_pass!(self, check_mac_def, mac, id);
1319 fn visit_mac(&mut self, mac: &'a ast::Mac) {
1320 // FIXME(#54110): So, this setup isn't really right. I think
1321 // that (a) the libsyntax visitor ought to be doing this as
1322 // part of `walk_mac`, and (b) we should be calling
1323 // `visit_path`, *but* that would require a `NodeId`, and I
1324 // want to get #53686 fixed quickly. -nmatsakis
1325 ast_visit::walk_path(self, &mac.node.path);
1327 run_early_pass!(self, check_mac, mac);
1330 fn visit_fn_header(&mut self, header: &'a ast::FnHeader) {
1331 // Unlike in HIR lowering and name resolution, the `AsyncArgument` statements are not added
1332 // to the function body and the arguments do not replace those in the declaration. They are
1333 // still visited manually here so that buffered lints can be emitted.
1334 if let ast::IsAsync::Async { ref arguments, .. } = header.asyncness.node {
1335 for a in arguments {
1336 // Visit the argument..
1337 if let Some(arg) = &a.arg {
1338 self.visit_pat(&arg.pat);
1339 if let ast::ArgSource::AsyncFn(pat) = &arg.source {
1340 self.visit_pat(pat);
1342 self.visit_ty(&arg.ty);
1345 // ..and the statement.
1346 self.visit_stmt(&a.move_stmt);
1347 if let Some(pat_stmt) = &a.pat_stmt {
1348 self.visit_stmt(&pat_stmt);
1355 struct LateLintPassObjects<'a> {
1356 lints: &'a mut [LateLintPassObject],
1359 impl LintPass for LateLintPassObjects<'_> {
1360 fn name(&self) -> &'static str {
1364 fn get_lints(&self) -> LintArray {
1369 macro_rules! expand_late_lint_pass_impl_methods {
1370 ([$a:tt, $hir:tt], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
1371 $(fn $name(&mut self, context: &LateContext<$a, $hir>, $($param: $arg),*) {
1372 for obj in self.lints.iter_mut() {
1373 obj.$name(context, $($param),*);
1379 macro_rules! late_lint_pass_impl {
1380 ([], [$hir:tt], $methods:tt) => (
1381 impl LateLintPass<'a, $hir> for LateLintPassObjects<'_> {
1382 expand_late_lint_pass_impl_methods!(['a, $hir], $methods);
1387 late_lint_methods!(late_lint_pass_impl, [], ['tcx]);
1389 fn late_lint_mod_pass<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
1390 tcx: TyCtxt<'_, 'tcx, 'tcx>,
1391 module_def_id: DefId,
1394 let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);
1396 let context = LateContext {
1398 tables: &ty::TypeckTables::empty(None),
1399 param_env: ty::ParamEnv::empty(),
1401 lint_store: tcx.sess.lint_store.borrow(),
1402 last_node_with_lint_attrs: tcx.hir().as_local_hir_id(module_def_id).unwrap(),
1407 let mut cx = LateContextAndPass {
1412 let (module, span, hir_id) = tcx.hir().get_module(module_def_id);
1413 cx.process_mod(module, span, hir_id);
1415 // Visit the crate attributes
1416 if hir_id == hir::CRATE_HIR_ID {
1417 walk_list!(cx, visit_attribute, tcx.hir().attrs_by_hir_id(hir::CRATE_HIR_ID));
1421 pub fn late_lint_mod<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
1422 tcx: TyCtxt<'_, 'tcx, 'tcx>,
1423 module_def_id: DefId,
1426 if tcx.sess.opts.debugging_opts.no_interleave_lints {
1427 // These passes runs in late_lint_crate with -Z no_interleave_lints
1431 late_lint_mod_pass(tcx, module_def_id, builtin_lints);
1433 let mut passes: Vec<_> = tcx.sess.lint_store.borrow().late_module_passes
1434 .iter().map(|pass| pass.fresh_late_pass()).collect();
1436 if !passes.is_empty() {
1437 late_lint_mod_pass(tcx, module_def_id, LateLintPassObjects { lints: &mut passes[..] });
1441 fn late_lint_pass_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
1442 tcx: TyCtxt<'_, 'tcx, 'tcx>,
1445 let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);
1447 let krate = tcx.hir().krate();
1449 let context = LateContext {
1451 tables: &ty::TypeckTables::empty(None),
1452 param_env: ty::ParamEnv::empty(),
1454 lint_store: tcx.sess.lint_store.borrow(),
1455 last_node_with_lint_attrs: hir::CRATE_HIR_ID,
1460 let mut cx = LateContextAndPass {
1465 // Visit the whole crate.
1466 cx.with_lint_attrs(hir::CRATE_HIR_ID, &krate.attrs, |cx| {
1467 // since the root module isn't visited as an item (because it isn't an
1468 // item), warn for it here.
1469 lint_callback!(cx, check_crate, krate);
1471 hir_visit::walk_crate(cx, krate);
1473 lint_callback!(cx, check_crate_post, krate);
1477 fn late_lint_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
1478 tcx: TyCtxt<'_, 'tcx, 'tcx>,
1481 let mut passes = tcx.sess.lint_store.borrow().late_passes.lock().take().unwrap();
1483 if !tcx.sess.opts.debugging_opts.no_interleave_lints {
1484 if !passes.is_empty() {
1485 late_lint_pass_crate(tcx, LateLintPassObjects { lints: &mut passes[..] });
1488 late_lint_pass_crate(tcx, builtin_lints);
1490 for pass in &mut passes {
1491 time(tcx.sess, &format!("running late lint: {}", pass.name()), || {
1492 late_lint_pass_crate(tcx, LateLintPassObjects { lints: slice::from_mut(pass) });
1496 let mut passes: Vec<_> = tcx.sess.lint_store.borrow().late_module_passes
1497 .iter().map(|pass| pass.fresh_late_pass()).collect();
1499 for pass in &mut passes {
1500 time(tcx.sess, &format!("running late module lint: {}", pass.name()), || {
1501 late_lint_pass_crate(tcx, LateLintPassObjects { lints: slice::from_mut(pass) });
1506 // Put the passes back in the session.
1507 *tcx.sess.lint_store.borrow().late_passes.lock() = Some(passes);
1510 /// Performs lint checking on a crate.
1511 pub fn check_crate<'tcx, T: for<'a> LateLintPass<'a, 'tcx>>(
1512 tcx: TyCtxt<'_, 'tcx, 'tcx>,
1513 builtin_lints: impl FnOnce() -> T + Send,
1516 time(tcx.sess, "crate lints", || {
1517 // Run whole crate non-incremental lints
1518 late_lint_crate(tcx, builtin_lints());
1521 time(tcx.sess, "module lints", || {
1522 // Run per-module lints
1523 par_iter(&tcx.hir().krate().modules).for_each(|(&module, _)| {
1524 tcx.ensure().lint_mod(tcx.hir().local_def_id(module));
1530 struct EarlyLintPassObjects<'a> {
1531 lints: &'a mut [EarlyLintPassObject],
1534 impl LintPass for EarlyLintPassObjects<'_> {
1535 fn name(&self) -> &'static str {
1539 fn get_lints(&self) -> LintArray {
1544 macro_rules! expand_early_lint_pass_impl_methods {
1545 ([$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
1546 $(fn $name(&mut self, context: &EarlyContext<'_>, $($param: $arg),*) {
1547 for obj in self.lints.iter_mut() {
1548 obj.$name(context, $($param),*);
1554 macro_rules! early_lint_pass_impl {
1555 ([], [$($methods:tt)*]) => (
1556 impl EarlyLintPass for EarlyLintPassObjects<'_> {
1557 expand_early_lint_pass_impl_methods!([$($methods)*]);
1562 early_lint_methods!(early_lint_pass_impl, []);
1564 fn early_lint_crate<T: EarlyLintPass>(
1568 buffered: LintBuffer,
1570 let mut cx = EarlyContextAndPass {
1571 context: EarlyContext::new(sess, krate, buffered),
1575 // Visit the whole crate.
1576 cx.with_lint_attrs(ast::CRATE_NODE_ID, &krate.attrs, |cx| {
1577 // since the root module isn't visited as an item (because it isn't an
1578 // item), warn for it here.
1579 run_early_pass!(cx, check_crate, krate);
1581 ast_visit::walk_crate(cx, krate);
1583 run_early_pass!(cx, check_crate_post, krate);
1588 pub fn check_ast_crate<T: EarlyLintPass>(
1591 pre_expansion: bool,
1594 let (mut passes, mut buffered) = if pre_expansion {
1596 sess.lint_store.borrow_mut().pre_expansion_passes.take().unwrap(),
1597 LintBuffer::default(),
1601 sess.lint_store.borrow_mut().early_passes.take().unwrap(),
1602 sess.buffered_lints.borrow_mut().take().unwrap(),
1606 if !sess.opts.debugging_opts.no_interleave_lints {
1607 buffered = early_lint_crate(sess, krate, builtin_lints, buffered);
1609 if !passes.is_empty() {
1610 buffered = early_lint_crate(
1613 EarlyLintPassObjects { lints: &mut passes[..] },
1618 for pass in &mut passes {
1619 buffered = time(sess, &format!("running lint: {}", pass.name()), || {
1623 EarlyLintPassObjects { lints: slice::from_mut(pass) },
1630 // Put the lint store levels and passes back in the session.
1632 sess.lint_store.borrow_mut().pre_expansion_passes = Some(passes);
1634 sess.lint_store.borrow_mut().early_passes = Some(passes);
1637 // All of the buffered lints should have been emitted at this point.
1638 // If not, that means that we somehow buffered a lint for a node id
1639 // that was not lint-checked (perhaps it doesn't exist?). This is a bug.
1641 // Rustdoc runs everybody-loops before the early lints and removes
1642 // function bodies, so it's totally possible for linted
1643 // node ids to not exist (e.g., macros defined within functions for the
1644 // unused_macro lint) anymore. So we only run this check
1645 // when we're not in rustdoc mode. (see issue #47639)
1646 if !sess.opts.actually_rustdoc {
1647 for (_id, lints) in buffered.map {
1648 for early_lint in lints {
1649 sess.delay_span_bug(early_lint.span, "failed to process buffered lint here");
1655 impl Encodable for LintId {
1656 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
1657 s.emit_str(&self.lint.name.to_lowercase())
1661 impl Decodable for LintId {
1663 fn decode<D: Decoder>(d: &mut D) -> Result<LintId, D::Error> {
1664 let s = d.read_str()?;
1665 ty::tls::with(|tcx| {
1666 match tcx.sess.lint_store.borrow().find_lints(&s) {
1669 panic!("invalid lint-id `{}`", s);
1673 Err(_) => panic!("invalid lint-id `{}`", s),