1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Implementation of lint checking.
13 //! The lint checking is mostly consolidated into one pass which runs
14 //! after all other analyses. Throughout compilation, lint warnings
15 //! can be added via the `add_lint` method on the Session structure. This
16 //! requires a span and an id of the node that the lint is being added to. The
17 //! lint isn't actually emitted at that time because it is unknown what the
18 //! actual lint level at that location is.
20 //! To actually emit lint warnings/errors, a separate pass is used.
21 //! A context keeps track of the current state of all lint levels.
22 //! Upon entering a node of the ast which can modify the lint settings, the
23 //! previous lint state is pushed onto a stack and the ast is then recursed
24 //! upon. As the ast is traversed, this keeps track of the current lint level
25 //! for all lint attributes.
27 use self::TargetLint::*;
30 use rustc_data_structures::sync::{RwLock, ReadGuard};
31 use lint::{EarlyLintPassObject, LateLintPassObject};
32 use lint::{Level, Lint, LintId, LintPass, LintBuffer};
33 use lint::builtin::BuiltinLintDiagnostics;
34 use lint::levels::{LintLevelSets, LintLevelsBuilder};
35 use middle::privacy::AccessLevels;
36 use rustc_serialize::{Decoder, Decodable, Encoder, Encodable};
37 use session::{config, early_error, Session};
38 use ty::{self, TyCtxt, Ty};
39 use ty::layout::{LayoutError, LayoutOf, TyLayout};
40 use util::nodemap::FxHashMap;
42 use std::default::Default as StdDefault;
45 use syntax_pos::{MultiSpan, Span};
46 use errors::DiagnosticBuilder;
48 use hir::def_id::LOCAL_CRATE;
49 use hir::intravisit as hir_visit;
50 use syntax::visit as ast_visit;
52 /// Information about the registered lints.
54 /// This is basically the subset of `Context` that we can
55 /// build early in the compile pipeline.
56 pub struct LintStore {
57 /// Registered lints. The bool is true if the lint was
58 /// added by a plugin.
59 lints: Vec<(&'static Lint, bool)>,
61 /// Trait objects for each lint pass.
62 /// This is only `None` while performing a lint pass. See the definition
63 /// of `LintSession::new`.
64 early_passes: Option<Vec<EarlyLintPassObject>>,
65 late_passes: Option<Vec<LateLintPassObject>>,
67 /// Lints indexed by name.
68 by_name: FxHashMap<String, TargetLint>,
70 /// Map of registered lint groups to what lints they expand to. The bool
71 /// is true if the lint group was added by a plugin.
72 lint_groups: FxHashMap<&'static str, (Vec<LintId>, bool)>,
74 /// Extra info for future incompatibility lints, describing the
75 /// issue or RFC that caused the incompatibility.
76 future_incompatible: FxHashMap<LintId, FutureIncompatibleInfo>,
79 pub struct LintSession<'a, PassObject> {
80 /// Reference to the store of registered lints.
81 lints: ReadGuard<'a, LintStore>,
83 /// Trait objects for each lint pass.
84 passes: Option<Vec<PassObject>>,
88 /// Lints that are buffered up early on in the `Session` before the
89 /// `LintLevels` is calculated
90 #[derive(PartialEq, RustcEncodable, RustcDecodable, Debug)]
91 pub struct BufferedEarlyLint {
93 pub ast_id: ast::NodeId,
96 pub diagnostic: BuiltinLintDiagnostics,
99 /// Extra information for a future incompatibility lint. See the call
100 /// to `register_future_incompatible` in `librustc_lint/lib.rs` for
102 pub struct FutureIncompatibleInfo {
104 /// e.g., a URL for an issue/PR/RFC or error code
105 pub reference: &'static str,
106 /// If this is an edition fixing lint, the edition in which
107 /// this lint becomes obsolete
108 pub edition: Option<edition::Edition>,
111 /// The target of the `by_name` map, which accounts for renaming/deprecation.
113 /// A direct lint target
116 /// Temporary renaming, used for easing migration pain; see #16545
117 Renamed(String, LintId),
119 /// Lint with this name existed previously, but has been removed/deprecated.
120 /// The string argument is the reason for removal.
124 pub enum FindLintError {
129 pub enum CheckLintNameResult<'a> {
131 /// Lint doesn't exist
133 /// The lint is either renamed or removed. This is the warning
139 pub fn new() -> LintStore {
142 early_passes: Some(vec![]),
143 late_passes: Some(vec![]),
144 by_name: FxHashMap(),
145 future_incompatible: FxHashMap(),
146 lint_groups: FxHashMap(),
150 pub fn get_lints<'t>(&'t self) -> &'t [(&'static Lint, bool)] {
154 pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
155 self.lint_groups.iter().map(|(k, v)| (*k,
160 pub fn register_early_pass(&mut self,
161 sess: Option<&Session>,
163 pass: EarlyLintPassObject) {
164 self.push_pass(sess, from_plugin, &pass);
165 self.early_passes.as_mut().unwrap().push(pass);
168 pub fn register_late_pass(&mut self,
169 sess: Option<&Session>,
171 pass: LateLintPassObject) {
172 self.push_pass(sess, from_plugin, &pass);
173 self.late_passes.as_mut().unwrap().push(pass);
176 // Helper method for register_early/late_pass
177 fn push_pass<P: LintPass + ?Sized + 'static>(&mut self,
178 sess: Option<&Session>,
181 for lint in pass.get_lints() {
182 self.lints.push((lint, from_plugin));
184 let id = LintId::of(lint);
185 if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
186 let msg = format!("duplicate specification of lint {}", lint.name_lower());
187 match (sess, from_plugin) {
188 // We load builtin lints first, so a duplicate is a compiler bug.
189 // Use early_error when handling -W help with no crate.
190 (None, _) => early_error(config::ErrorOutputType::default(), &msg[..]),
191 (Some(_), false) => bug!("{}", msg),
193 // A duplicate name from a plugin is a user error.
194 (Some(sess), true) => sess.err(&msg[..]),
200 pub fn register_future_incompatible(&mut self,
201 sess: Option<&Session>,
202 lints: Vec<FutureIncompatibleInfo>) {
204 for edition in edition::ALL_EDITIONS {
205 let lints = lints.iter().filter(|f| f.edition == Some(*edition)).map(|f| f.id)
206 .collect::<Vec<_>>();
207 if !lints.is_empty() {
208 self.register_group(sess, false, edition.lint_name(), lints)
212 let mut future_incompatible = vec![];
214 future_incompatible.push(lint.id);
215 self.future_incompatible.insert(lint.id, lint);
218 self.register_group(sess, false, "future_incompatible", future_incompatible);
223 pub fn future_incompatible(&self, id: LintId) -> Option<&FutureIncompatibleInfo> {
224 self.future_incompatible.get(&id)
227 pub fn register_group(&mut self, sess: Option<&Session>,
228 from_plugin: bool, name: &'static str,
230 let new = self.lint_groups.insert(name, (to, from_plugin)).is_none();
233 let msg = format!("duplicate specification of lint group {}", name);
234 match (sess, from_plugin) {
235 // We load builtin lints first, so a duplicate is a compiler bug.
236 // Use early_error when handling -W help with no crate.
237 (None, _) => early_error(config::ErrorOutputType::default(), &msg[..]),
238 (Some(_), false) => bug!("{}", msg),
240 // A duplicate name from a plugin is a user error.
241 (Some(sess), true) => sess.err(&msg[..]),
246 pub fn register_renamed(&mut self, old_name: &str, new_name: &str) {
247 let target = match self.by_name.get(new_name) {
248 Some(&Id(lint_id)) => lint_id.clone(),
249 _ => bug!("invalid lint renaming of {} to {}", old_name, new_name)
251 self.by_name.insert(old_name.to_string(), Renamed(new_name.to_string(), target));
254 pub fn register_removed(&mut self, name: &str, reason: &str) {
255 self.by_name.insert(name.into(), Removed(reason.into()));
258 pub fn find_lints(&self, lint_name: &str) -> Result<Vec<LintId>, FindLintError> {
259 match self.by_name.get(lint_name) {
260 Some(&Id(lint_id)) => Ok(vec![lint_id]),
261 Some(&Renamed(_, lint_id)) => {
264 Some(&Removed(_)) => {
265 Err(FindLintError::Removed)
268 match self.lint_groups.get(lint_name) {
269 Some(v) => Ok(v.0.clone()),
270 None => Err(FindLintError::Removed)
276 /// Checks the validity of lint names derived from the command line
277 pub fn check_lint_name_cmdline(&self,
281 let db = match self.check_lint_name(lint_name) {
282 CheckLintNameResult::Ok(_) => None,
283 CheckLintNameResult::Warning(ref msg) => {
284 Some(sess.struct_warn(msg))
286 CheckLintNameResult::NoLint => {
287 Some(struct_err!(sess, E0602, "unknown lint: `{}`", lint_name))
291 if let Some(mut db) = db {
292 let msg = format!("requested on the command line with `{} {}`",
294 Level::Allow => "-A",
297 Level::Forbid => "-F",
305 /// Checks the name of a lint for its existence, and whether it was
306 /// renamed or removed. Generates a DiagnosticBuilder containing a
307 /// warning for renamed and removed lints. This is over both lint
308 /// names from attributes and those passed on the command line. Since
309 /// it emits non-fatal warnings and there are *two* lint passes that
310 /// inspect attributes, this is only run from the late pass to avoid
311 /// printing duplicate warnings.
312 pub fn check_lint_name(&self, lint_name: &str) -> CheckLintNameResult {
313 match self.by_name.get(lint_name) {
314 Some(&Renamed(ref new_name, _)) => {
315 CheckLintNameResult::Warning(
316 format!("lint {} has been renamed to {}", lint_name, new_name)
319 Some(&Removed(ref reason)) => {
320 CheckLintNameResult::Warning(
321 format!("lint {} has been removed: {}", lint_name, reason)
325 match self.lint_groups.get(lint_name) {
326 None => CheckLintNameResult::NoLint,
327 Some(ids) => CheckLintNameResult::Ok(&ids.0),
330 Some(&Id(ref id)) => CheckLintNameResult::Ok(slice::from_ref(id)),
335 impl<'a, PassObject: LintPassObject> LintSession<'a, PassObject> {
336 /// Creates a new `LintSession`, by moving out the `LintStore`'s initial
337 /// lint levels and pass objects. These can be restored using the `restore`
339 fn new(store: &'a RwLock<LintStore>) -> LintSession<'a, PassObject> {
340 let mut s = store.borrow_mut();
341 let passes = PassObject::take_passes(&mut *s);
344 lints: store.borrow(),
349 /// Restores the levels back to the original lint store.
350 fn restore(self, store: &RwLock<LintStore>) {
352 let mut s = store.borrow_mut();
353 PassObject::restore_passes(&mut *s, self.passes);
357 /// Context for lint checking after type checking.
358 pub struct LateContext<'a, 'tcx: 'a> {
359 /// Type context we're checking in.
360 pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
362 /// Side-tables for the body we are in.
363 pub tables: &'a ty::TypeckTables<'tcx>,
365 /// Parameter environment for the item we are in.
366 pub param_env: ty::ParamEnv<'tcx>,
368 /// Items accessible from the crate being checked.
369 pub access_levels: &'a AccessLevels,
371 /// The store of registered lints and the lint levels.
372 lint_sess: LintSession<'tcx, LateLintPassObject>,
374 last_ast_node_with_lint_attrs: ast::NodeId,
376 /// Generic type parameters in scope for the item we are in.
377 pub generics: Option<&'tcx hir::Generics>,
380 /// Context for lint checking of the AST, after expansion, before lowering to
382 pub struct EarlyContext<'a> {
383 /// Type context we're checking in.
384 pub sess: &'a Session,
386 /// The crate being checked.
387 pub krate: &'a ast::Crate,
389 builder: LintLevelsBuilder<'a>,
391 /// The store of registered lints and the lint levels.
392 lint_sess: LintSession<'a, EarlyLintPassObject>,
394 buffered: LintBuffer,
397 /// Convenience macro for calling a `LintPass` method on every pass in the context.
398 macro_rules! run_lints { ($cx:expr, $f:ident, $ps:ident, $($args:expr),*) => ({
399 // Move the vector of passes out of `$cx` so that we can
400 // iterate over it mutably while passing `$cx` to the methods.
401 let mut passes = $cx.lint_sess_mut().passes.take().unwrap();
402 for obj in &mut passes {
403 obj.$f($cx, $($args),*);
405 $cx.lint_sess_mut().passes = Some(passes);
408 pub trait LintPassObject: Sized {
409 fn take_passes(store: &mut LintStore) -> Option<Vec<Self>>;
410 fn restore_passes(store: &mut LintStore, passes: Option<Vec<Self>>);
413 impl LintPassObject for EarlyLintPassObject {
414 fn take_passes(store: &mut LintStore) -> Option<Vec<Self>> {
415 store.early_passes.take()
418 fn restore_passes(store: &mut LintStore, passes: Option<Vec<Self>>) {
419 store.early_passes = passes;
423 impl LintPassObject for LateLintPassObject {
424 fn take_passes(store: &mut LintStore) -> Option<Vec<Self>> {
425 store.late_passes.take()
428 fn restore_passes(store: &mut LintStore, passes: Option<Vec<Self>>) {
429 store.late_passes = passes;
434 pub trait LintContext<'tcx>: Sized {
435 type PassObject: LintPassObject;
437 fn sess(&self) -> &Session;
438 fn lints(&self) -> &LintStore;
439 fn lint_sess(&self) -> &LintSession<'tcx, Self::PassObject>;
440 fn lint_sess_mut(&mut self) -> &mut LintSession<'tcx, Self::PassObject>;
441 fn enter_attrs(&mut self, attrs: &'tcx [ast::Attribute]);
442 fn exit_attrs(&mut self, attrs: &'tcx [ast::Attribute]);
444 fn lookup_and_emit<S: Into<MultiSpan>>(&self,
448 self.lookup(lint, span, msg).emit();
451 fn lookup_and_emit_with_diagnostics<S: Into<MultiSpan>>(&self,
455 diagnostic: BuiltinLintDiagnostics) {
456 let mut db = self.lookup(lint, span, msg);
457 diagnostic.run(self.sess(), &mut db);
461 fn lookup<S: Into<MultiSpan>>(&self,
465 -> DiagnosticBuilder;
467 /// Emit a lint at the appropriate level, for a particular span.
468 fn span_lint<S: Into<MultiSpan>>(&self, lint: &'static Lint, span: S, msg: &str) {
469 self.lookup_and_emit(lint, Some(span), msg);
472 fn struct_span_lint<S: Into<MultiSpan>>(&self,
476 -> DiagnosticBuilder {
477 self.lookup(lint, Some(span), msg)
480 /// Emit a lint and note at the appropriate level, for a particular span.
481 fn span_lint_note(&self, lint: &'static Lint, span: Span, msg: &str,
482 note_span: Span, note: &str) {
483 let mut err = self.lookup(lint, Some(span), msg);
484 if note_span == span {
487 err.span_note(note_span, note);
492 /// Emit a lint and help at the appropriate level, for a particular span.
493 fn span_lint_help(&self, lint: &'static Lint, span: Span,
494 msg: &str, help: &str) {
495 let mut err = self.lookup(lint, Some(span), msg);
496 self.span_lint(lint, span, msg);
497 err.span_help(span, help);
501 /// Emit a lint at the appropriate level, with no associated span.
502 fn lint(&self, lint: &'static Lint, msg: &str) {
503 self.lookup_and_emit(lint, None as Option<Span>, msg);
506 /// Merge the lints specified by any lint attributes into the
507 /// current lint context, call the provided function, then reset the
508 /// lints in effect to their previous state.
509 fn with_lint_attrs<F>(&mut self,
511 attrs: &'tcx [ast::Attribute],
513 where F: FnOnce(&mut Self);
517 impl<'a> EarlyContext<'a> {
518 fn new(sess: &'a Session,
519 krate: &'a ast::Crate) -> EarlyContext<'a> {
523 lint_sess: LintSession::new(&sess.lint_store),
524 builder: LintLevelSets::builder(sess),
525 buffered: sess.buffered_lints.borrow_mut().take().unwrap(),
529 fn check_id(&mut self, id: ast::NodeId) {
530 for early_lint in self.buffered.take(id) {
531 self.lookup_and_emit_with_diagnostics(early_lint.lint_id.lint,
532 Some(early_lint.span.clone()),
534 early_lint.diagnostic);
539 impl<'a, 'tcx> LintContext<'tcx> for LateContext<'a, 'tcx> {
540 type PassObject = LateLintPassObject;
542 /// Get the overall compiler `Session` object.
543 fn sess(&self) -> &Session {
547 fn lints(&self) -> &LintStore {
548 &*self.lint_sess.lints
551 fn lint_sess(&self) -> &LintSession<'tcx, Self::PassObject> {
555 fn lint_sess_mut(&mut self) -> &mut LintSession<'tcx, Self::PassObject> {
559 fn enter_attrs(&mut self, attrs: &'tcx [ast::Attribute]) {
560 debug!("late context: enter_attrs({:?})", attrs);
561 run_lints!(self, enter_lint_attrs, late_passes, attrs);
564 fn exit_attrs(&mut self, attrs: &'tcx [ast::Attribute]) {
565 debug!("late context: exit_attrs({:?})", attrs);
566 run_lints!(self, exit_lint_attrs, late_passes, attrs);
569 fn lookup<S: Into<MultiSpan>>(&self,
573 -> DiagnosticBuilder {
574 let id = self.last_ast_node_with_lint_attrs;
576 Some(s) => self.tcx.struct_span_lint_node(lint, id, s, msg),
577 None => self.tcx.struct_lint_node(lint, id, msg),
581 fn with_lint_attrs<F>(&mut self,
583 attrs: &'tcx [ast::Attribute],
585 where F: FnOnce(&mut Self)
587 let prev = self.last_ast_node_with_lint_attrs;
588 self.last_ast_node_with_lint_attrs = id;
589 self.enter_attrs(attrs);
591 self.exit_attrs(attrs);
592 self.last_ast_node_with_lint_attrs = prev;
596 impl<'a> LintContext<'a> for EarlyContext<'a> {
597 type PassObject = EarlyLintPassObject;
599 /// Get the overall compiler `Session` object.
600 fn sess(&self) -> &Session {
604 fn lints(&self) -> &LintStore {
605 &*self.lint_sess.lints
608 fn lint_sess(&self) -> &LintSession<'a, Self::PassObject> {
612 fn lint_sess_mut(&mut self) -> &mut LintSession<'a, Self::PassObject> {
616 fn enter_attrs(&mut self, attrs: &'a [ast::Attribute]) {
617 debug!("early context: enter_attrs({:?})", attrs);
618 run_lints!(self, enter_lint_attrs, early_passes, attrs);
621 fn exit_attrs(&mut self, attrs: &'a [ast::Attribute]) {
622 debug!("early context: exit_attrs({:?})", attrs);
623 run_lints!(self, exit_lint_attrs, early_passes, attrs);
626 fn lookup<S: Into<MultiSpan>>(&self,
630 -> DiagnosticBuilder {
631 self.builder.struct_lint(lint, span.map(|s| s.into()), msg)
634 fn with_lint_attrs<F>(&mut self,
636 attrs: &'a [ast::Attribute],
638 where F: FnOnce(&mut Self)
640 let push = self.builder.push(attrs);
642 self.enter_attrs(attrs);
644 self.exit_attrs(attrs);
645 self.builder.pop(push);
649 impl<'a, 'tcx> LateContext<'a, 'tcx> {
650 fn with_param_env<F>(&mut self, id: ast::NodeId, f: F)
651 where F: FnOnce(&mut Self),
653 let old_param_env = self.param_env;
654 self.param_env = self.tcx.param_env(self.tcx.hir.local_def_id(id));
656 self.param_env = old_param_env;
658 pub fn current_lint_root(&self) -> ast::NodeId {
659 self.last_ast_node_with_lint_attrs
663 impl<'a, 'tcx> LayoutOf for &'a LateContext<'a, 'tcx> {
665 type TyLayout = Result<TyLayout<'tcx>, LayoutError<'tcx>>;
667 fn layout_of(self, ty: Ty<'tcx>) -> Self::TyLayout {
668 self.tcx.layout_of(self.param_env.and(ty))
672 impl<'a, 'tcx> hir_visit::Visitor<'tcx> for LateContext<'a, 'tcx> {
673 /// Because lints are scoped lexically, we want to walk nested
674 /// items in the context of the outer item, so enable
676 fn nested_visit_map<'this>(&'this mut self) -> hir_visit::NestedVisitorMap<'this, 'tcx> {
677 hir_visit::NestedVisitorMap::All(&self.tcx.hir)
680 fn visit_nested_body(&mut self, body: hir::BodyId) {
681 let old_tables = self.tables;
682 self.tables = self.tcx.body_tables(body);
683 let body = self.tcx.hir.body(body);
684 self.visit_body(body);
685 self.tables = old_tables;
688 fn visit_body(&mut self, body: &'tcx hir::Body) {
689 run_lints!(self, check_body, late_passes, body);
690 hir_visit::walk_body(self, body);
691 run_lints!(self, check_body_post, late_passes, body);
694 fn visit_item(&mut self, it: &'tcx hir::Item) {
695 let generics = self.generics.take();
696 self.generics = it.node.generics();
697 self.with_lint_attrs(it.id, &it.attrs, |cx| {
698 cx.with_param_env(it.id, |cx| {
699 run_lints!(cx, check_item, late_passes, it);
700 hir_visit::walk_item(cx, it);
701 run_lints!(cx, check_item_post, late_passes, it);
704 self.generics = generics;
707 fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem) {
708 self.with_lint_attrs(it.id, &it.attrs, |cx| {
709 cx.with_param_env(it.id, |cx| {
710 run_lints!(cx, check_foreign_item, late_passes, it);
711 hir_visit::walk_foreign_item(cx, it);
712 run_lints!(cx, check_foreign_item_post, late_passes, it);
717 fn visit_pat(&mut self, p: &'tcx hir::Pat) {
718 run_lints!(self, check_pat, late_passes, p);
719 hir_visit::walk_pat(self, p);
722 fn visit_expr(&mut self, e: &'tcx hir::Expr) {
723 self.with_lint_attrs(e.id, &e.attrs, |cx| {
724 run_lints!(cx, check_expr, late_passes, e);
725 hir_visit::walk_expr(cx, e);
726 run_lints!(cx, check_expr_post, late_passes, e);
730 fn visit_stmt(&mut self, s: &'tcx hir::Stmt) {
731 // statement attributes are actually just attributes on one of
735 // so we keep track of lint levels there
736 run_lints!(self, check_stmt, late_passes, s);
737 hir_visit::walk_stmt(self, s);
740 fn visit_fn(&mut self, fk: hir_visit::FnKind<'tcx>, decl: &'tcx hir::FnDecl,
741 body_id: hir::BodyId, span: Span, id: ast::NodeId) {
742 // Wrap in tables here, not just in visit_nested_body,
743 // in order for `check_fn` to be able to use them.
744 let old_tables = self.tables;
745 self.tables = self.tcx.body_tables(body_id);
746 let body = self.tcx.hir.body(body_id);
747 run_lints!(self, check_fn, late_passes, fk, decl, body, span, id);
748 hir_visit::walk_fn(self, fk, decl, body_id, span, id);
749 run_lints!(self, check_fn_post, late_passes, fk, decl, body, span, id);
750 self.tables = old_tables;
753 fn visit_variant_data(&mut self,
754 s: &'tcx hir::VariantData,
756 g: &'tcx hir::Generics,
757 item_id: ast::NodeId,
759 run_lints!(self, check_struct_def, late_passes, s, name, g, item_id);
760 hir_visit::walk_struct_def(self, s);
761 run_lints!(self, check_struct_def_post, late_passes, s, name, g, item_id);
764 fn visit_struct_field(&mut self, s: &'tcx hir::StructField) {
765 self.with_lint_attrs(s.id, &s.attrs, |cx| {
766 run_lints!(cx, check_struct_field, late_passes, s);
767 hir_visit::walk_struct_field(cx, s);
771 fn visit_variant(&mut self,
772 v: &'tcx hir::Variant,
773 g: &'tcx hir::Generics,
774 item_id: ast::NodeId) {
775 self.with_lint_attrs(v.node.data.id(), &v.node.attrs, |cx| {
776 run_lints!(cx, check_variant, late_passes, v, g);
777 hir_visit::walk_variant(cx, v, g, item_id);
778 run_lints!(cx, check_variant_post, late_passes, v, g);
782 fn visit_ty(&mut self, t: &'tcx hir::Ty) {
783 run_lints!(self, check_ty, late_passes, t);
784 hir_visit::walk_ty(self, t);
787 fn visit_name(&mut self, sp: Span, name: ast::Name) {
788 run_lints!(self, check_name, late_passes, sp, name);
791 fn visit_mod(&mut self, m: &'tcx hir::Mod, s: Span, n: ast::NodeId) {
792 run_lints!(self, check_mod, late_passes, m, s, n);
793 hir_visit::walk_mod(self, m, n);
794 run_lints!(self, check_mod_post, late_passes, m, s, n);
797 fn visit_local(&mut self, l: &'tcx hir::Local) {
798 self.with_lint_attrs(l.id, &l.attrs, |cx| {
799 run_lints!(cx, check_local, late_passes, l);
800 hir_visit::walk_local(cx, l);
804 fn visit_block(&mut self, b: &'tcx hir::Block) {
805 run_lints!(self, check_block, late_passes, b);
806 hir_visit::walk_block(self, b);
807 run_lints!(self, check_block_post, late_passes, b);
810 fn visit_arm(&mut self, a: &'tcx hir::Arm) {
811 run_lints!(self, check_arm, late_passes, a);
812 hir_visit::walk_arm(self, a);
815 fn visit_decl(&mut self, d: &'tcx hir::Decl) {
816 run_lints!(self, check_decl, late_passes, d);
817 hir_visit::walk_decl(self, d);
820 fn visit_generic_param(&mut self, p: &'tcx hir::GenericParam) {
821 run_lints!(self, check_generic_param, late_passes, p);
822 hir_visit::walk_generic_param(self, p);
825 fn visit_generics(&mut self, g: &'tcx hir::Generics) {
826 run_lints!(self, check_generics, late_passes, g);
827 hir_visit::walk_generics(self, g);
830 fn visit_where_predicate(&mut self, p: &'tcx hir::WherePredicate) {
831 run_lints!(self, check_where_predicate, late_passes, p);
832 hir_visit::walk_where_predicate(self, p);
835 fn visit_poly_trait_ref(&mut self, t: &'tcx hir::PolyTraitRef,
836 m: hir::TraitBoundModifier) {
837 run_lints!(self, check_poly_trait_ref, late_passes, t, m);
838 hir_visit::walk_poly_trait_ref(self, t, m);
841 fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) {
842 let generics = self.generics.take();
843 self.generics = Some(&trait_item.generics);
844 self.with_lint_attrs(trait_item.id, &trait_item.attrs, |cx| {
845 cx.with_param_env(trait_item.id, |cx| {
846 run_lints!(cx, check_trait_item, late_passes, trait_item);
847 hir_visit::walk_trait_item(cx, trait_item);
848 run_lints!(cx, check_trait_item_post, late_passes, trait_item);
851 self.generics = generics;
854 fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
855 let generics = self.generics.take();
856 self.generics = Some(&impl_item.generics);
857 self.with_lint_attrs(impl_item.id, &impl_item.attrs, |cx| {
858 cx.with_param_env(impl_item.id, |cx| {
859 run_lints!(cx, check_impl_item, late_passes, impl_item);
860 hir_visit::walk_impl_item(cx, impl_item);
861 run_lints!(cx, check_impl_item_post, late_passes, impl_item);
864 self.generics = generics;
867 fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
868 run_lints!(self, check_lifetime, late_passes, lt);
869 hir_visit::walk_lifetime(self, lt);
872 fn visit_path(&mut self, p: &'tcx hir::Path, id: ast::NodeId) {
873 run_lints!(self, check_path, late_passes, p, id);
874 hir_visit::walk_path(self, p);
877 fn visit_attribute(&mut self, attr: &'tcx ast::Attribute) {
878 run_lints!(self, check_attribute, late_passes, attr);
882 impl<'a> ast_visit::Visitor<'a> for EarlyContext<'a> {
883 fn visit_item(&mut self, it: &'a ast::Item) {
884 self.with_lint_attrs(it.id, &it.attrs, |cx| {
885 run_lints!(cx, check_item, early_passes, it);
886 ast_visit::walk_item(cx, it);
887 run_lints!(cx, check_item_post, early_passes, it);
891 fn visit_foreign_item(&mut self, it: &'a ast::ForeignItem) {
892 self.with_lint_attrs(it.id, &it.attrs, |cx| {
893 run_lints!(cx, check_foreign_item, early_passes, it);
894 ast_visit::walk_foreign_item(cx, it);
895 run_lints!(cx, check_foreign_item_post, early_passes, it);
899 fn visit_pat(&mut self, p: &'a ast::Pat) {
900 run_lints!(self, check_pat, early_passes, p);
902 ast_visit::walk_pat(self, p);
905 fn visit_expr(&mut self, e: &'a ast::Expr) {
906 self.with_lint_attrs(e.id, &e.attrs, |cx| {
907 run_lints!(cx, check_expr, early_passes, e);
908 ast_visit::walk_expr(cx, e);
912 fn visit_stmt(&mut self, s: &'a ast::Stmt) {
913 run_lints!(self, check_stmt, early_passes, s);
915 ast_visit::walk_stmt(self, s);
918 fn visit_fn(&mut self, fk: ast_visit::FnKind<'a>, decl: &'a ast::FnDecl,
919 span: Span, id: ast::NodeId) {
920 run_lints!(self, check_fn, early_passes, fk, decl, span, id);
922 ast_visit::walk_fn(self, fk, decl, span);
923 run_lints!(self, check_fn_post, early_passes, fk, decl, span, id);
926 fn visit_variant_data(&mut self,
927 s: &'a ast::VariantData,
929 g: &'a ast::Generics,
930 item_id: ast::NodeId,
932 run_lints!(self, check_struct_def, early_passes, s, ident, g, item_id);
933 self.check_id(s.id());
934 ast_visit::walk_struct_def(self, s);
935 run_lints!(self, check_struct_def_post, early_passes, s, ident, g, item_id);
938 fn visit_struct_field(&mut self, s: &'a ast::StructField) {
939 self.with_lint_attrs(s.id, &s.attrs, |cx| {
940 run_lints!(cx, check_struct_field, early_passes, s);
941 ast_visit::walk_struct_field(cx, s);
945 fn visit_variant(&mut self, v: &'a ast::Variant, g: &'a ast::Generics, item_id: ast::NodeId) {
946 self.with_lint_attrs(item_id, &v.node.attrs, |cx| {
947 run_lints!(cx, check_variant, early_passes, v, g);
948 ast_visit::walk_variant(cx, v, g, item_id);
949 run_lints!(cx, check_variant_post, early_passes, v, g);
953 fn visit_ty(&mut self, t: &'a ast::Ty) {
954 run_lints!(self, check_ty, early_passes, t);
956 ast_visit::walk_ty(self, t);
959 fn visit_ident(&mut self, ident: ast::Ident) {
960 run_lints!(self, check_ident, early_passes, ident);
963 fn visit_mod(&mut self, m: &'a ast::Mod, s: Span, _a: &[ast::Attribute], n: ast::NodeId) {
964 run_lints!(self, check_mod, early_passes, m, s, n);
966 ast_visit::walk_mod(self, m);
967 run_lints!(self, check_mod_post, early_passes, m, s, n);
970 fn visit_local(&mut self, l: &'a ast::Local) {
971 self.with_lint_attrs(l.id, &l.attrs, |cx| {
972 run_lints!(cx, check_local, early_passes, l);
973 ast_visit::walk_local(cx, l);
977 fn visit_block(&mut self, b: &'a ast::Block) {
978 run_lints!(self, check_block, early_passes, b);
980 ast_visit::walk_block(self, b);
981 run_lints!(self, check_block_post, early_passes, b);
984 fn visit_arm(&mut self, a: &'a ast::Arm) {
985 run_lints!(self, check_arm, early_passes, a);
986 ast_visit::walk_arm(self, a);
989 fn visit_expr_post(&mut self, e: &'a ast::Expr) {
990 run_lints!(self, check_expr_post, early_passes, e);
993 fn visit_generic_param(&mut self, param: &'a ast::GenericParam) {
994 run_lints!(self, check_generic_param, early_passes, param);
995 ast_visit::walk_generic_param(self, param);
998 fn visit_generics(&mut self, g: &'a ast::Generics) {
999 run_lints!(self, check_generics, early_passes, g);
1000 ast_visit::walk_generics(self, g);
1003 fn visit_where_predicate(&mut self, p: &'a ast::WherePredicate) {
1004 run_lints!(self, check_where_predicate, early_passes, p);
1005 ast_visit::walk_where_predicate(self, p);
1008 fn visit_poly_trait_ref(&mut self, t: &'a ast::PolyTraitRef, m: &'a ast::TraitBoundModifier) {
1009 run_lints!(self, check_poly_trait_ref, early_passes, t, m);
1010 ast_visit::walk_poly_trait_ref(self, t, m);
1013 fn visit_trait_item(&mut self, trait_item: &'a ast::TraitItem) {
1014 self.with_lint_attrs(trait_item.id, &trait_item.attrs, |cx| {
1015 run_lints!(cx, check_trait_item, early_passes, trait_item);
1016 ast_visit::walk_trait_item(cx, trait_item);
1017 run_lints!(cx, check_trait_item_post, early_passes, trait_item);
1021 fn visit_impl_item(&mut self, impl_item: &'a ast::ImplItem) {
1022 self.with_lint_attrs(impl_item.id, &impl_item.attrs, |cx| {
1023 run_lints!(cx, check_impl_item, early_passes, impl_item);
1024 ast_visit::walk_impl_item(cx, impl_item);
1025 run_lints!(cx, check_impl_item_post, early_passes, impl_item);
1029 fn visit_lifetime(&mut self, lt: &'a ast::Lifetime) {
1030 run_lints!(self, check_lifetime, early_passes, lt);
1031 self.check_id(lt.id);
1034 fn visit_path(&mut self, p: &'a ast::Path, id: ast::NodeId) {
1035 run_lints!(self, check_path, early_passes, p, id);
1037 ast_visit::walk_path(self, p);
1040 fn visit_attribute(&mut self, attr: &'a ast::Attribute) {
1041 run_lints!(self, check_attribute, early_passes, attr);
1044 fn visit_mac_def(&mut self, _mac: &'a ast::MacroDef, id: ast::NodeId) {
1050 /// Perform lint checking on a crate.
1052 /// Consumes the `lint_store` field of the `Session`.
1053 pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
1054 let access_levels = &tcx.privacy_access_levels(LOCAL_CRATE);
1056 let krate = tcx.hir.krate();
1058 let mut cx = LateContext {
1060 tables: &ty::TypeckTables::empty(None),
1061 param_env: ty::ParamEnv::empty(),
1063 lint_sess: LintSession::new(&tcx.sess.lint_store),
1064 last_ast_node_with_lint_attrs: ast::CRATE_NODE_ID,
1068 // Visit the whole crate.
1069 cx.with_lint_attrs(ast::CRATE_NODE_ID, &krate.attrs, |cx| {
1070 // since the root module isn't visited as an item (because it isn't an
1071 // item), warn for it here.
1072 run_lints!(cx, check_crate, late_passes, krate);
1074 hir_visit::walk_crate(cx, krate);
1076 run_lints!(cx, check_crate_post, late_passes, krate);
1079 // Put the lint store levels and passes back in the session.
1080 cx.lint_sess.restore(&tcx.sess.lint_store);
1083 pub fn check_ast_crate(sess: &Session, krate: &ast::Crate) {
1084 let mut cx = EarlyContext::new(sess, krate);
1086 // Visit the whole crate.
1087 cx.with_lint_attrs(ast::CRATE_NODE_ID, &krate.attrs, |cx| {
1088 // since the root module isn't visited as an item (because it isn't an
1089 // item), warn for it here.
1090 run_lints!(cx, check_crate, early_passes, krate);
1092 ast_visit::walk_crate(cx, krate);
1094 run_lints!(cx, check_crate_post, early_passes, krate);
1097 // Put the lint store levels and passes back in the session.
1098 cx.lint_sess.restore(&sess.lint_store);
1100 // All of the buffered lints should have been emitted at this point.
1101 // If not, that means that we somehow buffered a lint for a node id
1102 // that was not lint-checked (perhaps it doesn't exist?). This is a bug.
1104 // Rustdoc runs everybody-loops before the early lints and removes
1105 // function bodies, so it's totally possible for linted
1106 // node ids to not exist (e.g. macros defined within functions for the
1107 // unused_macro lint) anymore. So we only run this check
1108 // when we're not in rustdoc mode. (see issue #47639)
1109 if !sess.opts.actually_rustdoc {
1110 for (_id, lints) in cx.buffered.map {
1111 for early_lint in lints {
1112 sess.delay_span_bug(early_lint.span, "failed to process buffered lint here");
1118 impl Encodable for LintId {
1119 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
1120 s.emit_str(&self.lint.name.to_lowercase())
1124 impl Decodable for LintId {
1126 fn decode<D: Decoder>(d: &mut D) -> Result<LintId, D::Error> {
1127 let s = d.read_str()?;
1128 ty::tls::with(|tcx| {
1129 match tcx.sess.lint_store.borrow().find_lints(&s) {
1132 panic!("invalid lint-id `{}`", s);
1136 Err(_) => panic!("invalid lint-id `{}`", s),