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 just
14 //! before translation to LLVM bytecode. 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 just before
21 //! translation. 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.
26 use self::TargetLint::*;
28 use dep_graph::DepNode;
29 use middle::privacy::AccessLevels;
31 use session::{config, early_error, Session};
32 use lint::{Level, LevelSource, Lint, LintId, LintPass};
33 use lint::{EarlyLintPassObject, LateLintPassObject};
34 use lint::{Default, CommandLine, Node, Allow, Warn, Deny, Forbid};
36 use util::nodemap::FnvHashMap;
39 use std::default::Default as StdDefault;
41 use syntax::attr::{self, AttrMetaMethods};
42 use syntax::parse::token::InternedString;
45 use errors::DiagnosticBuilder;
47 use hir::intravisit as hir_visit;
48 use hir::intravisit::{IdVisitor, IdVisitingOperation};
49 use syntax::visit as ast_visit;
51 /// Information about the registered lints.
53 /// This is basically the subset of `Context` that we can
54 /// build early in the compile pipeline.
55 pub struct LintStore {
56 /// Registered lints. The bool is true if the lint was
57 /// added by a plugin.
58 lints: Vec<(&'static Lint, bool)>,
60 /// Trait objects for each lint pass.
61 /// This is only `None` while iterating over the objects. See the definition
63 early_passes: Option<Vec<EarlyLintPassObject>>,
64 late_passes: Option<Vec<LateLintPassObject>>,
66 /// Lints indexed by name.
67 by_name: FnvHashMap<String, TargetLint>,
69 /// Current levels of each lint, and where they were set.
70 levels: FnvHashMap<LintId, LevelSource>,
72 /// Map of registered lint groups to what lints they expand to. The bool
73 /// is true if the lint group was added by a plugin.
74 lint_groups: FnvHashMap<&'static str, (Vec<LintId>, bool)>,
76 /// Extra info for future incompatibility lints, descibing the
77 /// issue or RFC that caused the incompatibility.
78 future_incompatible: FnvHashMap<LintId, FutureIncompatibleInfo>,
80 /// Maximum level a lint can be
81 lint_cap: Option<Level>,
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 pub reference: &'static str // e.g., a URL for an issue/PR/RFC or error code
92 /// The targed of the `by_name` map, which accounts for renaming/deprecation.
94 /// A direct lint target
97 /// Temporary renaming, used for easing migration pain; see #16545
98 Renamed(String, LintId),
100 /// Lint with this name existed previously, but has been removed/deprecated.
101 /// The string argument is the reason for removal.
111 fn get_level_source(&self, lint: LintId) -> LevelSource {
112 match self.levels.get(&lint) {
114 None => (Allow, Default),
118 fn set_level(&mut self, lint: LintId, mut lvlsrc: LevelSource) {
119 if let Some(cap) = self.lint_cap {
120 lvlsrc.0 = cmp::min(lvlsrc.0, cap);
122 if lvlsrc.0 == Allow {
123 self.levels.remove(&lint);
125 self.levels.insert(lint, lvlsrc);
129 pub fn new() -> LintStore {
132 early_passes: Some(vec!()),
133 late_passes: Some(vec!()),
134 by_name: FnvHashMap(),
135 levels: FnvHashMap(),
136 future_incompatible: FnvHashMap(),
137 lint_groups: FnvHashMap(),
142 pub fn get_lints<'t>(&'t self) -> &'t [(&'static Lint, bool)] {
146 pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
147 self.lint_groups.iter().map(|(k, v)| (*k,
152 pub fn register_early_pass(&mut self,
153 sess: Option<&Session>,
155 pass: EarlyLintPassObject) {
156 self.push_pass(sess, from_plugin, &pass);
157 self.early_passes.as_mut().unwrap().push(pass);
160 pub fn register_late_pass(&mut self,
161 sess: Option<&Session>,
163 pass: LateLintPassObject) {
164 self.push_pass(sess, from_plugin, &pass);
165 self.late_passes.as_mut().unwrap().push(pass);
168 // Helper method for register_early/late_pass
169 fn push_pass<P: LintPass + ?Sized + 'static>(&mut self,
170 sess: Option<&Session>,
173 for &lint in pass.get_lints() {
174 self.lints.push((*lint, from_plugin));
176 let id = LintId::of(*lint);
177 if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
178 let msg = format!("duplicate specification of lint {}", lint.name_lower());
179 match (sess, from_plugin) {
180 // We load builtin lints first, so a duplicate is a compiler bug.
181 // Use early_error when handling -W help with no crate.
182 (None, _) => early_error(config::ErrorOutputType::default(), &msg[..]),
183 (Some(_), false) => bug!("{}", msg),
185 // A duplicate name from a plugin is a user error.
186 (Some(sess), true) => sess.err(&msg[..]),
190 if lint.default_level != Allow {
191 self.levels.insert(id, (lint.default_level, Default));
196 pub fn register_future_incompatible(&mut self,
197 sess: Option<&Session>,
198 lints: Vec<FutureIncompatibleInfo>) {
199 let ids = lints.iter().map(|f| f.id).collect();
200 self.register_group(sess, false, "future_incompatible", ids);
202 self.future_incompatible.insert(info.id, info);
206 pub fn future_incompatible(&self, id: LintId) -> Option<&FutureIncompatibleInfo> {
207 self.future_incompatible.get(&id)
210 pub fn register_group(&mut self, sess: Option<&Session>,
211 from_plugin: bool, name: &'static str,
213 let new = self.lint_groups.insert(name, (to, from_plugin)).is_none();
216 let msg = format!("duplicate specification of lint group {}", name);
217 match (sess, from_plugin) {
218 // We load builtin lints first, so a duplicate is a compiler bug.
219 // Use early_error when handling -W help with no crate.
220 (None, _) => early_error(config::ErrorOutputType::default(), &msg[..]),
221 (Some(_), false) => bug!("{}", msg),
223 // A duplicate name from a plugin is a user error.
224 (Some(sess), true) => sess.err(&msg[..]),
229 pub fn register_renamed(&mut self, old_name: &str, new_name: &str) {
230 let target = match self.by_name.get(new_name) {
231 Some(&Id(lint_id)) => lint_id.clone(),
232 _ => bug!("invalid lint renaming of {} to {}", old_name, new_name)
234 self.by_name.insert(old_name.to_string(), Renamed(new_name.to_string(), target));
237 pub fn register_removed(&mut self, name: &str, reason: &str) {
238 self.by_name.insert(name.into(), Removed(reason.into()));
241 #[allow(unused_variables)]
242 fn find_lint(&self, lint_name: &str, sess: &Session, span: Option<Span>)
243 -> Result<LintId, FindLintError>
245 match self.by_name.get(lint_name) {
246 Some(&Id(lint_id)) => Ok(lint_id),
247 Some(&Renamed(_, lint_id)) => {
250 Some(&Removed(ref reason)) => {
251 Err(FindLintError::Removed)
253 None => Err(FindLintError::NotFound)
257 pub fn process_command_line(&mut self, sess: &Session) {
258 for &(ref lint_name, level) in &sess.opts.lint_opts {
259 check_lint_name_cmdline(sess, self,
260 &lint_name[..], level);
262 match self.find_lint(&lint_name[..], sess, None) {
263 Ok(lint_id) => self.set_level(lint_id, (level, CommandLine)),
264 Err(FindLintError::Removed) => { }
266 match self.lint_groups.iter().map(|(&x, pair)| (x, pair.0.clone()))
267 .collect::<FnvHashMap<&'static str,
269 .get(&lint_name[..]) {
272 .map(|lint_id: &LintId|
273 self.set_level(*lint_id, (level, CommandLine)))
274 .collect::<Vec<()>>();
277 // The lint or lint group doesn't exist.
278 // This is an error, but it was handled
279 // by check_lint_name_cmdline.
286 self.lint_cap = sess.opts.lint_cap;
287 if let Some(cap) = self.lint_cap {
288 for level in self.levels.iter_mut().map(|p| &mut (p.1).0) {
289 *level = cmp::min(*level, cap);
295 /// Context for lint checking after type checking.
296 pub struct LateContext<'a, 'tcx: 'a> {
297 /// Type context we're checking in.
298 pub tcx: TyCtxt<'a, 'tcx, 'tcx>,
300 /// The crate being checked.
301 pub krate: &'a hir::Crate,
303 /// Items accessible from the crate being checked.
304 pub access_levels: &'a AccessLevels,
306 /// The store of registered lints.
309 /// When recursing into an attributed node of the ast which modifies lint
310 /// levels, this stack keeps track of the previous lint levels of whatever
312 level_stack: Vec<(LintId, LevelSource)>,
315 /// Context for lint checking of the AST, after expansion, before lowering to
317 pub struct EarlyContext<'a> {
318 /// Type context we're checking in.
319 pub sess: &'a Session,
321 /// The crate being checked.
322 pub krate: &'a ast::Crate,
324 /// The store of registered lints.
327 /// When recursing into an attributed node of the ast which modifies lint
328 /// levels, this stack keeps track of the previous lint levels of whatever
330 level_stack: Vec<(LintId, LevelSource)>,
333 /// Convenience macro for calling a `LintPass` method on every pass in the context.
334 macro_rules! run_lints { ($cx:expr, $f:ident, $ps:ident, $($args:expr),*) => ({
335 // Move the vector of passes out of `$cx` so that we can
336 // iterate over it mutably while passing `$cx` to the methods.
337 let mut passes = $cx.mut_lints().$ps.take().unwrap();
338 for obj in &mut passes {
339 obj.$f($cx, $($args),*);
341 $cx.mut_lints().$ps = Some(passes);
344 /// Parse the lint attributes into a vector, with `Err`s for malformed lint
345 /// attributes. Writing this as an iterator is an enormous mess.
346 // See also the hir version just below.
347 pub fn gather_attrs(attrs: &[ast::Attribute])
348 -> Vec<Result<(InternedString, Level, Span), Span>> {
349 let mut out = vec!();
351 let r = gather_attr(attr);
352 out.extend(r.into_iter());
357 pub fn gather_attr(attr: &ast::Attribute)
358 -> Vec<Result<(InternedString, Level, Span), Span>> {
359 let mut out = vec!();
361 let level = match Level::from_str(&attr.name()) {
366 attr::mark_used(attr);
368 let meta = &attr.node.value;
369 let metas = match meta.node {
370 ast::MetaItemKind::List(_, ref metas) => metas,
372 out.push(Err(meta.span));
378 out.push(match meta.node {
379 ast::MetaItemKind::Word(ref lint_name) => Ok((lint_name.clone(), level, meta.span)),
387 /// Emit a lint as a warning or an error (or not at all)
388 /// according to `level`.
390 /// This lives outside of `Context` so it can be used by checks
391 /// in trans that run after the main lint pass is finished. Most
392 /// lints elsewhere in the compiler should call
393 /// `Session::add_lint()` instead.
394 pub fn raw_emit_lint(sess: &Session,
400 raw_struct_lint(sess, lints, lint, lvlsrc, span, msg).emit();
403 pub fn raw_struct_lint<'a>(sess: &'a Session,
409 -> DiagnosticBuilder<'a> {
410 let (mut level, source) = lvlsrc;
412 return sess.diagnostic().struct_dummy();
415 let name = lint.name_lower();
417 let msg = match source {
419 format!("{}, #[{}({})] on by default", msg,
420 level.as_str(), name)
423 format!("{} [-{} {}]", msg,
425 Warn => 'W', Deny => 'D', Forbid => 'F',
427 }, name.replace("_", "-"))
435 // For purposes of printing, we can treat forbid as deny.
436 if level == Forbid { level = Deny; }
438 let mut err = match (level, span) {
439 (Warn, Some(sp)) => sess.struct_span_warn(sp, &msg[..]),
440 (Warn, None) => sess.struct_warn(&msg[..]),
441 (Deny, Some(sp)) => sess.struct_span_err(sp, &msg[..]),
442 (Deny, None) => sess.struct_err(&msg[..]),
443 _ => bug!("impossible level in raw_emit_lint"),
446 // Check for future incompatibility lints and issue a stronger warning.
447 if let Some(future_incompatible) = lints.future_incompatible(LintId::of(lint)) {
448 let explanation = format!("this was previously accepted by the compiler \
449 but is being phased out; \
450 it will become a hard error in a future release!");
451 let citation = format!("for more information, see {}",
452 future_incompatible.reference);
453 err.warn(&explanation);
457 if let Some(span) = def {
458 let explanation = "lint level defined here";
459 err.span_note(span, &explanation);
465 pub trait LintContext: Sized {
466 fn sess(&self) -> &Session;
467 fn lints(&self) -> &LintStore;
468 fn mut_lints(&mut self) -> &mut LintStore;
469 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)>;
470 fn enter_attrs(&mut self, attrs: &[ast::Attribute]);
471 fn exit_attrs(&mut self, attrs: &[ast::Attribute]);
473 /// Get the level of `lint` at the current position of the lint
475 fn current_level(&self, lint: &'static Lint) -> Level {
476 self.lints().levels.get(&LintId::of(lint)).map_or(Allow, |&(lvl, _)| lvl)
479 fn level_src(&self, lint: &'static Lint) -> Option<LevelSource> {
480 self.lints().levels.get(&LintId::of(lint)).map(|ls| match ls {
482 let lint_id = LintId::of(builtin::WARNINGS);
483 let warn_src = self.lints().get_level_source(lint_id);
484 if warn_src.0 != Warn {
494 fn lookup_and_emit(&self, lint: &'static Lint, span: Option<Span>, msg: &str) {
495 let (level, src) = match self.level_src(lint) {
500 raw_emit_lint(&self.sess(), self.lints(), lint, (level, src), span, msg);
507 -> DiagnosticBuilder {
508 let (level, src) = match self.level_src(lint) {
509 None => return self.sess().diagnostic().struct_dummy(),
513 raw_struct_lint(&self.sess(), self.lints(), lint, (level, src), span, msg)
516 /// Emit a lint at the appropriate level, for a particular span.
517 fn span_lint(&self, lint: &'static Lint, span: Span, msg: &str) {
518 self.lookup_and_emit(lint, Some(span), msg);
521 fn struct_span_lint(&self,
525 -> DiagnosticBuilder {
526 self.lookup(lint, Some(span), msg)
529 /// Emit a lint and note at the appropriate level, for a particular span.
530 fn span_lint_note(&self, lint: &'static Lint, span: Span, msg: &str,
531 note_span: Span, note: &str) {
532 let mut err = self.lookup(lint, Some(span), msg);
533 if self.current_level(lint) != Level::Allow {
534 if note_span == span {
537 err.span_note(note_span, note);
543 /// Emit a lint and help at the appropriate level, for a particular span.
544 fn span_lint_help(&self, lint: &'static Lint, span: Span,
545 msg: &str, help: &str) {
546 let mut err = self.lookup(lint, Some(span), msg);
547 self.span_lint(lint, span, msg);
548 if self.current_level(lint) != Level::Allow {
549 err.span_help(span, help);
554 /// Emit a lint at the appropriate level, with no associated span.
555 fn lint(&self, lint: &'static Lint, msg: &str) {
556 self.lookup_and_emit(lint, None, msg);
559 /// Merge the lints specified by any lint attributes into the
560 /// current lint context, call the provided function, then reset the
561 /// lints in effect to their previous state.
562 fn with_lint_attrs<F>(&mut self,
563 attrs: &[ast::Attribute],
565 where F: FnOnce(&mut Self),
567 // Parse all of the lint attributes, and then add them all to the
568 // current dictionary of lint information. Along the way, keep a history
569 // of what we changed so we can roll everything back after invoking the
573 for result in gather_attrs(attrs) {
574 let v = match result {
576 span_err!(self.sess(), span, E0452,
577 "malformed lint attribute");
580 Ok((lint_name, level, span)) => {
581 match self.lints().find_lint(&lint_name, &self.sess(), Some(span)) {
582 Ok(lint_id) => vec![(lint_id, level, span)],
583 Err(FindLintError::NotFound) => {
584 match self.lints().lint_groups.get(&lint_name[..]) {
585 Some(&(ref v, _)) => v.iter()
586 .map(|lint_id: &LintId|
587 (*lint_id, level, span))
590 // The lint or lint group doesn't exist.
591 // This is an error, but it was handled
592 // by check_lint_name_attribute.
597 Err(FindLintError::Removed) => { continue; }
602 for (lint_id, level, span) in v {
603 let now = self.lints().get_level_source(lint_id).0;
604 if now == Forbid && level != Forbid {
605 let lint_name = lint_id.as_str();
606 span_err!(self.sess(), span, E0453,
607 "{}({}) overruled by outer forbid({})",
608 level.as_str(), lint_name,
610 } else if now != level {
611 let src = self.lints().get_level_source(lint_id).1;
612 self.level_stack().push((lint_id, (now, src)));
614 self.mut_lints().set_level(lint_id, (level, Node(span)));
619 self.enter_attrs(attrs);
621 self.exit_attrs(attrs);
625 let (lint, lvlsrc) = self.level_stack().pop().unwrap();
626 self.mut_lints().set_level(lint, lvlsrc);
632 impl<'a> EarlyContext<'a> {
633 fn new(sess: &'a Session,
634 krate: &'a ast::Crate) -> EarlyContext<'a> {
635 // We want to own the lint store, so move it out of the session. Remember
636 // to put it back later...
637 let lint_store = mem::replace(&mut *sess.lint_store.borrow_mut(),
648 impl<'a, 'tcx> LateContext<'a, 'tcx> {
649 fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>,
650 krate: &'a hir::Crate,
651 access_levels: &'a AccessLevels) -> LateContext<'a, 'tcx> {
652 // We want to own the lint store, so move it out of the session.
653 let lint_store = mem::replace(&mut *tcx.sess.lint_store.borrow_mut(),
659 access_levels: access_levels,
665 fn visit_ids<F>(&mut self, f: F)
666 where F: FnOnce(&mut IdVisitor<LateContext>)
668 let mut v = IdVisitor::new(self);
673 impl<'a, 'tcx> LintContext for LateContext<'a, 'tcx> {
674 /// Get the overall compiler `Session` object.
675 fn sess(&self) -> &Session {
679 fn lints(&self) -> &LintStore {
683 fn mut_lints(&mut self) -> &mut LintStore {
687 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)> {
688 &mut self.level_stack
691 fn enter_attrs(&mut self, attrs: &[ast::Attribute]) {
692 debug!("late context: enter_attrs({:?})", attrs);
693 run_lints!(self, enter_lint_attrs, late_passes, attrs);
696 fn exit_attrs(&mut self, attrs: &[ast::Attribute]) {
697 debug!("late context: exit_attrs({:?})", attrs);
698 run_lints!(self, exit_lint_attrs, late_passes, attrs);
702 impl<'a> LintContext for EarlyContext<'a> {
703 /// Get the overall compiler `Session` object.
704 fn sess(&self) -> &Session {
708 fn lints(&self) -> &LintStore {
712 fn mut_lints(&mut self) -> &mut LintStore {
716 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)> {
717 &mut self.level_stack
720 fn enter_attrs(&mut self, attrs: &[ast::Attribute]) {
721 debug!("early context: enter_attrs({:?})", attrs);
722 run_lints!(self, enter_lint_attrs, early_passes, attrs);
725 fn exit_attrs(&mut self, attrs: &[ast::Attribute]) {
726 debug!("early context: exit_attrs({:?})", attrs);
727 run_lints!(self, exit_lint_attrs, early_passes, attrs);
731 impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
732 /// Because lints are scoped lexically, we want to walk nested
733 /// items in the context of the outer item, so enable
735 fn visit_nested_item(&mut self, item: hir::ItemId) {
737 self.visit_item(tcx.map.expect_item(item.id))
740 fn visit_item(&mut self, it: &hir::Item) {
741 self.with_lint_attrs(&it.attrs, |cx| {
742 run_lints!(cx, check_item, late_passes, it);
743 cx.visit_ids(|v| v.visit_item(it));
744 hir_visit::walk_item(cx, it);
745 run_lints!(cx, check_item_post, late_passes, it);
749 fn visit_foreign_item(&mut self, it: &hir::ForeignItem) {
750 self.with_lint_attrs(&it.attrs, |cx| {
751 run_lints!(cx, check_foreign_item, late_passes, it);
752 hir_visit::walk_foreign_item(cx, it);
753 run_lints!(cx, check_foreign_item_post, late_passes, it);
757 fn visit_pat(&mut self, p: &hir::Pat) {
758 run_lints!(self, check_pat, late_passes, p);
759 hir_visit::walk_pat(self, p);
762 fn visit_expr(&mut self, e: &hir::Expr) {
763 self.with_lint_attrs(&e.attrs, |cx| {
764 run_lints!(cx, check_expr, late_passes, e);
765 hir_visit::walk_expr(cx, e);
769 fn visit_stmt(&mut self, s: &hir::Stmt) {
770 // statement attributes are actually just attributes on one of
774 // so we keep track of lint levels there
775 run_lints!(self, check_stmt, late_passes, s);
776 hir_visit::walk_stmt(self, s);
779 fn visit_fn(&mut self, fk: hir_visit::FnKind<'v>, decl: &'v hir::FnDecl,
780 body: &'v hir::Block, span: Span, id: ast::NodeId) {
781 run_lints!(self, check_fn, late_passes, fk, decl, body, span, id);
782 hir_visit::walk_fn(self, fk, decl, body, span);
783 run_lints!(self, check_fn_post, late_passes, fk, decl, body, span, id);
786 fn visit_variant_data(&mut self,
787 s: &hir::VariantData,
790 item_id: ast::NodeId,
792 run_lints!(self, check_struct_def, late_passes, s, name, g, item_id);
793 hir_visit::walk_struct_def(self, s);
794 run_lints!(self, check_struct_def_post, late_passes, s, name, g, item_id);
797 fn visit_struct_field(&mut self, s: &hir::StructField) {
798 self.with_lint_attrs(&s.attrs, |cx| {
799 run_lints!(cx, check_struct_field, late_passes, s);
800 hir_visit::walk_struct_field(cx, s);
804 fn visit_variant(&mut self, v: &hir::Variant, g: &hir::Generics, item_id: ast::NodeId) {
805 self.with_lint_attrs(&v.node.attrs, |cx| {
806 run_lints!(cx, check_variant, late_passes, v, g);
807 hir_visit::walk_variant(cx, v, g, item_id);
808 run_lints!(cx, check_variant_post, late_passes, v, g);
812 fn visit_ty(&mut self, t: &hir::Ty) {
813 run_lints!(self, check_ty, late_passes, t);
814 hir_visit::walk_ty(self, t);
817 fn visit_name(&mut self, sp: Span, name: ast::Name) {
818 run_lints!(self, check_name, late_passes, sp, name);
821 fn visit_mod(&mut self, m: &hir::Mod, s: Span, n: ast::NodeId) {
822 run_lints!(self, check_mod, late_passes, m, s, n);
823 hir_visit::walk_mod(self, m);
824 run_lints!(self, check_mod_post, late_passes, m, s, n);
827 fn visit_local(&mut self, l: &hir::Local) {
828 self.with_lint_attrs(&l.attrs, |cx| {
829 run_lints!(cx, check_local, late_passes, l);
830 hir_visit::walk_local(cx, l);
834 fn visit_block(&mut self, b: &hir::Block) {
835 run_lints!(self, check_block, late_passes, b);
836 hir_visit::walk_block(self, b);
837 run_lints!(self, check_block_post, late_passes, b);
840 fn visit_arm(&mut self, a: &hir::Arm) {
841 run_lints!(self, check_arm, late_passes, a);
842 hir_visit::walk_arm(self, a);
845 fn visit_decl(&mut self, d: &hir::Decl) {
846 run_lints!(self, check_decl, late_passes, d);
847 hir_visit::walk_decl(self, d);
850 fn visit_expr_post(&mut self, e: &hir::Expr) {
851 run_lints!(self, check_expr_post, late_passes, e);
854 fn visit_generics(&mut self, g: &hir::Generics) {
855 run_lints!(self, check_generics, late_passes, g);
856 hir_visit::walk_generics(self, g);
859 fn visit_trait_item(&mut self, trait_item: &hir::TraitItem) {
860 self.with_lint_attrs(&trait_item.attrs, |cx| {
861 run_lints!(cx, check_trait_item, late_passes, trait_item);
862 cx.visit_ids(|v| v.visit_trait_item(trait_item));
863 hir_visit::walk_trait_item(cx, trait_item);
864 run_lints!(cx, check_trait_item_post, late_passes, trait_item);
868 fn visit_impl_item(&mut self, impl_item: &hir::ImplItem) {
869 self.with_lint_attrs(&impl_item.attrs, |cx| {
870 run_lints!(cx, check_impl_item, late_passes, impl_item);
871 cx.visit_ids(|v| v.visit_impl_item(impl_item));
872 hir_visit::walk_impl_item(cx, impl_item);
873 run_lints!(cx, check_impl_item_post, late_passes, impl_item);
877 fn visit_lifetime(&mut self, lt: &hir::Lifetime) {
878 run_lints!(self, check_lifetime, late_passes, lt);
881 fn visit_lifetime_def(&mut self, lt: &hir::LifetimeDef) {
882 run_lints!(self, check_lifetime_def, late_passes, lt);
885 fn visit_path(&mut self, p: &hir::Path, id: ast::NodeId) {
886 run_lints!(self, check_path, late_passes, p, id);
887 hir_visit::walk_path(self, p);
890 fn visit_path_list_item(&mut self, prefix: &hir::Path, item: &hir::PathListItem) {
891 run_lints!(self, check_path_list_item, late_passes, item);
892 hir_visit::walk_path_list_item(self, prefix, item);
895 fn visit_attribute(&mut self, attr: &ast::Attribute) {
896 check_lint_name_attribute(self, attr);
897 run_lints!(self, check_attribute, late_passes, attr);
901 impl<'a> ast_visit::Visitor for EarlyContext<'a> {
902 fn visit_item(&mut self, it: &ast::Item) {
903 self.with_lint_attrs(&it.attrs, |cx| {
904 run_lints!(cx, check_item, early_passes, it);
905 ast_visit::walk_item(cx, it);
906 run_lints!(cx, check_item_post, early_passes, it);
910 fn visit_foreign_item(&mut self, it: &ast::ForeignItem) {
911 self.with_lint_attrs(&it.attrs, |cx| {
912 run_lints!(cx, check_foreign_item, early_passes, it);
913 ast_visit::walk_foreign_item(cx, it);
914 run_lints!(cx, check_foreign_item_post, early_passes, it);
918 fn visit_pat(&mut self, p: &ast::Pat) {
919 run_lints!(self, check_pat, early_passes, p);
920 ast_visit::walk_pat(self, p);
923 fn visit_expr(&mut self, e: &ast::Expr) {
924 self.with_lint_attrs(&e.attrs, |cx| {
925 run_lints!(cx, check_expr, early_passes, e);
926 ast_visit::walk_expr(cx, e);
930 fn visit_stmt(&mut self, s: &ast::Stmt) {
931 run_lints!(self, check_stmt, early_passes, s);
932 ast_visit::walk_stmt(self, s);
935 fn visit_fn(&mut self, fk: ast_visit::FnKind, decl: &ast::FnDecl,
936 body: &ast::Block, span: Span, id: ast::NodeId) {
937 run_lints!(self, check_fn, early_passes, fk, decl, body, span, id);
938 ast_visit::walk_fn(self, fk, decl, body, span);
939 run_lints!(self, check_fn_post, early_passes, fk, decl, body, span, id);
942 fn visit_variant_data(&mut self,
943 s: &ast::VariantData,
946 item_id: ast::NodeId,
948 run_lints!(self, check_struct_def, early_passes, s, ident, g, item_id);
949 ast_visit::walk_struct_def(self, s);
950 run_lints!(self, check_struct_def_post, early_passes, s, ident, g, item_id);
953 fn visit_struct_field(&mut self, s: &ast::StructField) {
954 self.with_lint_attrs(&s.attrs, |cx| {
955 run_lints!(cx, check_struct_field, early_passes, s);
956 ast_visit::walk_struct_field(cx, s);
960 fn visit_variant(&mut self, v: &ast::Variant, g: &ast::Generics, item_id: ast::NodeId) {
961 self.with_lint_attrs(&v.node.attrs, |cx| {
962 run_lints!(cx, check_variant, early_passes, v, g);
963 ast_visit::walk_variant(cx, v, g, item_id);
964 run_lints!(cx, check_variant_post, early_passes, v, g);
968 fn visit_ty(&mut self, t: &ast::Ty) {
969 run_lints!(self, check_ty, early_passes, t);
970 ast_visit::walk_ty(self, t);
973 fn visit_ident(&mut self, sp: Span, id: ast::Ident) {
974 run_lints!(self, check_ident, early_passes, sp, id);
977 fn visit_mod(&mut self, m: &ast::Mod, s: Span, n: ast::NodeId) {
978 run_lints!(self, check_mod, early_passes, m, s, n);
979 ast_visit::walk_mod(self, m);
980 run_lints!(self, check_mod_post, early_passes, m, s, n);
983 fn visit_local(&mut self, l: &ast::Local) {
984 self.with_lint_attrs(&l.attrs, |cx| {
985 run_lints!(cx, check_local, early_passes, l);
986 ast_visit::walk_local(cx, l);
990 fn visit_block(&mut self, b: &ast::Block) {
991 run_lints!(self, check_block, early_passes, b);
992 ast_visit::walk_block(self, b);
993 run_lints!(self, check_block_post, early_passes, b);
996 fn visit_arm(&mut self, a: &ast::Arm) {
997 run_lints!(self, check_arm, early_passes, a);
998 ast_visit::walk_arm(self, a);
1001 fn visit_expr_post(&mut self, e: &ast::Expr) {
1002 run_lints!(self, check_expr_post, early_passes, e);
1005 fn visit_generics(&mut self, g: &ast::Generics) {
1006 run_lints!(self, check_generics, early_passes, g);
1007 ast_visit::walk_generics(self, g);
1010 fn visit_trait_item(&mut self, trait_item: &ast::TraitItem) {
1011 self.with_lint_attrs(&trait_item.attrs, |cx| {
1012 run_lints!(cx, check_trait_item, early_passes, trait_item);
1013 ast_visit::walk_trait_item(cx, trait_item);
1014 run_lints!(cx, check_trait_item_post, early_passes, trait_item);
1018 fn visit_impl_item(&mut self, impl_item: &ast::ImplItem) {
1019 self.with_lint_attrs(&impl_item.attrs, |cx| {
1020 run_lints!(cx, check_impl_item, early_passes, impl_item);
1021 ast_visit::walk_impl_item(cx, impl_item);
1022 run_lints!(cx, check_impl_item_post, early_passes, impl_item);
1026 fn visit_lifetime(&mut self, lt: &ast::Lifetime) {
1027 run_lints!(self, check_lifetime, early_passes, lt);
1030 fn visit_lifetime_def(&mut self, lt: &ast::LifetimeDef) {
1031 run_lints!(self, check_lifetime_def, early_passes, lt);
1034 fn visit_path(&mut self, p: &ast::Path, id: ast::NodeId) {
1035 run_lints!(self, check_path, early_passes, p, id);
1036 ast_visit::walk_path(self, p);
1039 fn visit_path_list_item(&mut self, prefix: &ast::Path, item: &ast::PathListItem) {
1040 run_lints!(self, check_path_list_item, early_passes, item);
1041 ast_visit::walk_path_list_item(self, prefix, item);
1044 fn visit_attribute(&mut self, attr: &ast::Attribute) {
1045 run_lints!(self, check_attribute, early_passes, attr);
1049 // Output any lints that were previously added to the session.
1050 impl<'a, 'tcx> IdVisitingOperation for LateContext<'a, 'tcx> {
1051 fn visit_id(&mut self, id: ast::NodeId) {
1052 if let Some(lints) = self.sess().lints.borrow_mut().remove(&id) {
1053 debug!("LateContext::visit_id: id={:?} lints={:?}", id, lints);
1054 for (lint_id, span, msg) in lints {
1055 self.span_lint(lint_id.lint, span, &msg[..])
1061 enum CheckLintNameResult {
1063 // Lint doesn't exist
1065 // The lint is either renamed or removed. This is the warning
1070 /// Checks the name of a lint for its existence, and whether it was
1071 /// renamed or removed. Generates a DiagnosticBuilder containing a
1072 /// warning for renamed and removed lints. This is over both lint
1073 /// names from attributes and those passed on the command line. Since
1074 /// it emits non-fatal warnings and there are *two* lint passes that
1075 /// inspect attributes, this is only run from the late pass to avoid
1076 /// printing duplicate warnings.
1077 fn check_lint_name(lint_cx: &LintStore,
1078 lint_name: &str) -> CheckLintNameResult {
1079 match lint_cx.by_name.get(lint_name) {
1080 Some(&Renamed(ref new_name, _)) => {
1081 CheckLintNameResult::Warning(
1082 format!("lint {} has been renamed to {}", lint_name, new_name)
1085 Some(&Removed(ref reason)) => {
1086 CheckLintNameResult::Warning(
1087 format!("lint {} has been removed: {}", lint_name, reason)
1091 match lint_cx.lint_groups.get(lint_name) {
1093 CheckLintNameResult::NoLint
1096 /* lint group exists */
1097 CheckLintNameResult::Ok
1103 CheckLintNameResult::Ok
1108 // Checks the validity of lint names derived from attributes
1109 fn check_lint_name_attribute(cx: &LateContext, attr: &ast::Attribute) {
1110 for result in gather_attr(attr) {
1113 // Malformed lint attr. Reported by with_lint_attrs
1116 Ok((lint_name, _, span)) => {
1117 match check_lint_name(&cx.lints,
1119 CheckLintNameResult::Ok => (),
1120 CheckLintNameResult::Warning(ref msg) => {
1121 cx.span_lint(builtin::RENAMED_AND_REMOVED_LINTS,
1124 CheckLintNameResult::NoLint => {
1125 cx.span_lint(builtin::UNKNOWN_LINTS, span,
1126 &format!("unknown lint: `{}`",
1135 // Checks the validity of lint names derived from the command line
1136 fn check_lint_name_cmdline(sess: &Session, lint_cx: &LintStore,
1137 lint_name: &str, level: Level) {
1138 let db = match check_lint_name(lint_cx, lint_name) {
1139 CheckLintNameResult::Ok => None,
1140 CheckLintNameResult::Warning(ref msg) => {
1141 Some(sess.struct_warn(msg))
1143 CheckLintNameResult::NoLint => {
1144 Some(sess.struct_err(&format!("unknown lint: `{}`", lint_name)))
1148 if let Some(mut db) = db {
1149 let msg = format!("requested on the command line with `{} {}`",
1151 Level::Allow => "-A",
1152 Level::Warn => "-W",
1153 Level::Deny => "-D",
1154 Level::Forbid => "-F",
1163 /// Perform lint checking on a crate.
1165 /// Consumes the `lint_store` field of the `Session`.
1166 pub fn check_crate<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1167 access_levels: &AccessLevels) {
1168 let _task = tcx.dep_graph.in_task(DepNode::LateLintCheck);
1170 let krate = tcx.map.krate();
1171 let mut cx = LateContext::new(tcx, krate, access_levels);
1173 // Visit the whole crate.
1174 cx.with_lint_attrs(&krate.attrs, |cx| {
1175 cx.visit_id(ast::CRATE_NODE_ID);
1177 hir_visit::walk_crate(v, krate);
1180 // since the root module isn't visited as an item (because it isn't an
1181 // item), warn for it here.
1182 run_lints!(cx, check_crate, late_passes, krate);
1184 hir_visit::walk_crate(cx, krate);
1186 run_lints!(cx, check_crate_post, late_passes, krate);
1189 // If we missed any lints added to the session, then there's a bug somewhere
1190 // in the iteration code.
1191 for (id, v) in tcx.sess.lints.borrow().iter() {
1192 for &(lint, span, ref msg) in v {
1194 "unprocessed lint {} at {}: {}",
1195 lint.as_str(), tcx.map.node_to_string(*id), *msg)
1199 // Put the lint store back in the session.
1200 mem::replace(&mut *tcx.sess.lint_store.borrow_mut(), cx.lints);
1203 pub fn check_ast_crate(sess: &Session, krate: &ast::Crate) {
1204 let mut cx = EarlyContext::new(sess, krate);
1206 // Visit the whole crate.
1207 cx.with_lint_attrs(&krate.attrs, |cx| {
1208 // Lints may be assigned to the whole crate.
1209 if let Some(lints) = cx.sess.lints.borrow_mut().remove(&ast::CRATE_NODE_ID) {
1210 for (lint_id, span, msg) in lints {
1211 cx.span_lint(lint_id.lint, span, &msg[..])
1215 // since the root module isn't visited as an item (because it isn't an
1216 // item), warn for it here.
1217 run_lints!(cx, check_crate, early_passes, krate);
1219 ast_visit::walk_crate(cx, krate);
1221 run_lints!(cx, check_crate_post, early_passes, krate);
1224 // Put the lint store back in the session.
1225 mem::replace(&mut *sess.lint_store.borrow_mut(), cx.lints);
1227 // If we missed any lints added to the session, then there's a bug somewhere
1228 // in the iteration code.
1229 for (_, v) in sess.lints.borrow().iter() {
1230 for &(lint, span, ref msg) in v {
1231 span_bug!(span, "unprocessed lint {}: {}", lint.as_str(), *msg)