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::{early_error, Session};
32 use lint::{Level, LevelSource, Lint, LintId, LintArray, LintPass};
33 use lint::{EarlyLintPass, EarlyLintPassObject, LateLintPass, LateLintPassObject};
34 use lint::{Default, CommandLine, Node, Allow, Warn, Deny, Forbid};
36 use util::nodemap::FnvHashMap;
38 use std::cell::RefCell;
41 use syntax::ast_util::{self, IdVisitingOperation};
42 use syntax::attr::{self, AttrMetaMethods};
43 use syntax::codemap::Span;
44 use syntax::errors::{self, DiagnosticBuilder};
45 use syntax::parse::token::InternedString;
47 use syntax::attr::ThinAttributesExt;
49 use rustc_front::util;
50 use rustc_front::intravisit as hir_visit;
51 use syntax::visit as ast_visit;
53 /// Information about the registered lints.
55 /// This is basically the subset of `Context` that we can
56 /// build early in the compile pipeline.
57 pub struct LintStore {
58 /// Registered lints. The bool is true if the lint was
59 /// added by a plugin.
60 lints: Vec<(&'static Lint, bool)>,
62 /// Trait objects for each lint pass.
63 /// This is only `None` while iterating over the objects. See the definition
65 early_passes: Option<Vec<EarlyLintPassObject>>,
66 late_passes: Option<Vec<LateLintPassObject>>,
68 /// Lints indexed by name.
69 by_name: FnvHashMap<String, TargetLint>,
71 /// Current levels of each lint, and where they were set.
72 levels: FnvHashMap<LintId, LevelSource>,
74 /// Map of registered lint groups to what lints they expand to. The bool
75 /// is true if the lint group was added by a plugin.
76 lint_groups: FnvHashMap<&'static str, (Vec<LintId>, bool)>,
78 /// Maximum level a lint can be
79 lint_cap: Option<Level>,
82 /// The targed of the `by_name` map, which accounts for renaming/deprecation.
84 /// A direct lint target
87 /// Temporary renaming, used for easing migration pain; see #16545
88 Renamed(String, LintId),
90 /// Lint with this name existed previously, but has been removed/deprecated.
91 /// The string argument is the reason for removal.
101 fn get_level_source(&self, lint: LintId) -> LevelSource {
102 match self.levels.get(&lint) {
104 None => (Allow, Default),
108 fn set_level(&mut self, lint: LintId, mut lvlsrc: LevelSource) {
109 if let Some(cap) = self.lint_cap {
110 lvlsrc.0 = cmp::min(lvlsrc.0, cap);
112 if lvlsrc.0 == Allow {
113 self.levels.remove(&lint);
115 self.levels.insert(lint, lvlsrc);
119 pub fn new() -> LintStore {
122 early_passes: Some(vec!()),
123 late_passes: Some(vec!()),
124 by_name: FnvHashMap(),
125 levels: FnvHashMap(),
126 lint_groups: FnvHashMap(),
131 pub fn get_lints<'t>(&'t self) -> &'t [(&'static Lint, bool)] {
135 pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
136 self.lint_groups.iter().map(|(k, v)| (*k,
141 pub fn register_early_pass(&mut self,
142 sess: Option<&Session>,
144 pass: EarlyLintPassObject) {
145 self.push_pass(sess, from_plugin, &pass);
146 self.early_passes.as_mut().unwrap().push(pass);
149 pub fn register_late_pass(&mut self,
150 sess: Option<&Session>,
152 pass: LateLintPassObject) {
153 self.push_pass(sess, from_plugin, &pass);
154 self.late_passes.as_mut().unwrap().push(pass);
157 // Helper method for register_early/late_pass
158 fn push_pass<P: LintPass + ?Sized + 'static>(&mut self,
159 sess: Option<&Session>,
162 for &lint in pass.get_lints() {
163 self.lints.push((*lint, from_plugin));
165 let id = LintId::of(*lint);
166 if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
167 let msg = format!("duplicate specification of lint {}", lint.name_lower());
168 match (sess, from_plugin) {
169 // We load builtin lints first, so a duplicate is a compiler bug.
170 // Use early_error when handling -W help with no crate.
171 (None, _) => early_error(errors::ColorConfig::Auto, &msg[..]),
172 (Some(sess), false) => sess.bug(&msg[..]),
174 // A duplicate name from a plugin is a user error.
175 (Some(sess), true) => sess.err(&msg[..]),
179 if lint.default_level != Allow {
180 self.levels.insert(id, (lint.default_level, Default));
185 pub fn register_group(&mut self, sess: Option<&Session>,
186 from_plugin: bool, name: &'static str,
188 let new = self.lint_groups.insert(name, (to, from_plugin)).is_none();
191 let msg = format!("duplicate specification of lint group {}", name);
192 match (sess, from_plugin) {
193 // We load builtin lints first, so a duplicate is a compiler bug.
194 // Use early_error when handling -W help with no crate.
195 (None, _) => early_error(errors::ColorConfig::Auto, &msg[..]),
196 (Some(sess), false) => sess.bug(&msg[..]),
198 // A duplicate name from a plugin is a user error.
199 (Some(sess), true) => sess.err(&msg[..]),
204 pub fn register_renamed(&mut self, old_name: &str, new_name: &str) {
205 let target = match self.by_name.get(new_name) {
206 Some(&Id(lint_id)) => lint_id.clone(),
207 _ => panic!("invalid lint renaming of {} to {}", old_name, new_name)
209 self.by_name.insert(old_name.to_string(), Renamed(new_name.to_string(), target));
212 pub fn register_removed(&mut self, name: &str, reason: &str) {
213 self.by_name.insert(name.into(), Removed(reason.into()));
216 #[allow(unused_variables)]
217 fn find_lint(&self, lint_name: &str, sess: &Session, span: Option<Span>)
218 -> Result<LintId, FindLintError>
220 match self.by_name.get(lint_name) {
221 Some(&Id(lint_id)) => Ok(lint_id),
222 Some(&Renamed(ref new_name, lint_id)) => {
223 let warning = format!("lint {} has been renamed to {}",
224 lint_name, new_name);
226 Some(span) => sess.span_warn(span, &warning[..]),
227 None => sess.warn(&warning[..]),
231 Some(&Removed(ref reason)) => {
232 let warning = format!("lint {} has been removed: {}", lint_name, reason);
234 Some(span) => sess.span_warn(span, &warning[..]),
235 None => sess.warn(&warning[..])
237 Err(FindLintError::Removed)
239 None => Err(FindLintError::NotFound)
243 pub fn process_command_line(&mut self, sess: &Session) {
244 for &(ref lint_name, level) in &sess.opts.lint_opts {
245 match self.find_lint(&lint_name[..], sess, None) {
246 Ok(lint_id) => self.set_level(lint_id, (level, CommandLine)),
248 match self.lint_groups.iter().map(|(&x, pair)| (x, pair.0.clone()))
249 .collect::<FnvHashMap<&'static str,
251 .get(&lint_name[..]) {
254 .map(|lint_id: &LintId|
255 self.set_level(*lint_id, (level, CommandLine)))
256 .collect::<Vec<()>>();
258 None => sess.err(&format!("unknown {} flag: {}",
259 level.as_str(), lint_name)),
265 self.lint_cap = sess.opts.lint_cap;
266 if let Some(cap) = self.lint_cap {
267 for level in self.levels.iter_mut().map(|p| &mut (p.1).0) {
268 *level = cmp::min(*level, cap);
274 /// Context for lint checking after type checking.
275 pub struct LateContext<'a, 'tcx: 'a> {
276 /// Type context we're checking in.
277 pub tcx: &'a ty::ctxt<'tcx>,
279 /// The crate being checked.
280 pub krate: &'a hir::Crate,
282 /// Items accessible from the crate being checked.
283 pub access_levels: &'a AccessLevels,
285 /// The store of registered lints.
288 /// When recursing into an attributed node of the ast which modifies lint
289 /// levels, this stack keeps track of the previous lint levels of whatever
291 level_stack: Vec<(LintId, LevelSource)>,
293 /// Level of lints for certain NodeIds, stored here because the body of
294 /// the lint needs to run in trans.
295 node_levels: RefCell<FnvHashMap<(ast::NodeId, LintId), LevelSource>>,
298 /// Context for lint checking of the AST, after expansion, before lowering to
300 pub struct EarlyContext<'a> {
301 /// Type context we're checking in.
302 pub sess: &'a Session,
304 /// The crate being checked.
305 pub krate: &'a ast::Crate,
307 /// The store of registered lints.
310 /// When recursing into an attributed node of the ast which modifies lint
311 /// levels, this stack keeps track of the previous lint levels of whatever
313 level_stack: Vec<(LintId, LevelSource)>,
316 /// Convenience macro for calling a `LintPass` method on every pass in the context.
317 macro_rules! run_lints { ($cx:expr, $f:ident, $ps:ident, $($args:expr),*) => ({
318 // Move the vector of passes out of `$cx` so that we can
319 // iterate over it mutably while passing `$cx` to the methods.
320 let mut passes = $cx.mut_lints().$ps.take().unwrap();
321 for obj in &mut passes {
322 obj.$f($cx, $($args),*);
324 $cx.mut_lints().$ps = Some(passes);
327 /// Parse the lint attributes into a vector, with `Err`s for malformed lint
328 /// attributes. Writing this as an iterator is an enormous mess.
329 // See also the hir version just below.
330 pub fn gather_attrs(attrs: &[ast::Attribute])
331 -> Vec<Result<(InternedString, Level, Span), Span>> {
332 let mut out = vec!();
334 let level = match Level::from_str(&attr.name()) {
339 attr::mark_used(attr);
341 let meta = &attr.node.value;
342 let metas = match meta.node {
343 ast::MetaList(_, ref metas) => metas,
345 out.push(Err(meta.span));
351 out.push(match meta.node {
352 ast::MetaWord(ref lint_name) => Ok((lint_name.clone(), level, meta.span)),
360 /// Emit a lint as a warning or an error (or not at all)
361 /// according to `level`.
363 /// This lives outside of `Context` so it can be used by checks
364 /// in trans that run after the main lint pass is finished. Most
365 /// lints elsewhere in the compiler should call
366 /// `Session::add_lint()` instead.
367 pub fn raw_emit_lint(sess: &Session,
373 raw_struct_lint(sess, lints, lint, lvlsrc, span, msg).emit();
376 pub fn raw_struct_lint<'a>(sess: &'a Session,
382 -> DiagnosticBuilder<'a> {
383 let (mut level, source) = lvlsrc;
385 return sess.diagnostic().struct_dummy();
388 let name = lint.name_lower();
390 let msg = match source {
392 format!("{}, #[{}({})] on by default", msg,
393 level.as_str(), name)
396 format!("{} [-{} {}]", msg,
398 Warn => 'W', Deny => 'D', Forbid => 'F',
400 }, name.replace("_", "-"))
408 // For purposes of printing, we can treat forbid as deny.
409 if level == Forbid { level = Deny; }
411 let mut err = match (level, span) {
412 (Warn, Some(sp)) => sess.struct_span_warn(sp, &msg[..]),
413 (Warn, None) => sess.struct_warn(&msg[..]),
414 (Deny, Some(sp)) => sess.struct_span_err(sp, &msg[..]),
415 (Deny, None) => sess.struct_err(&msg[..]),
416 _ => sess.bug("impossible level in raw_emit_lint"),
419 // Check for future incompatibility lints and issue a stronger warning.
420 let future_incompat_lints = &lints.lint_groups[builtin::FUTURE_INCOMPATIBLE];
421 let this_id = LintId::of(lint);
422 if future_incompat_lints.0.iter().any(|&id| id == this_id) {
423 let msg = "this lint will become a HARD ERROR in a future release!";
424 if let Some(sp) = span {
425 err.span_note(sp, msg);
431 if let Some(span) = def {
432 err.span_note(span, "lint level defined here");
438 pub trait LintContext: Sized {
439 fn sess(&self) -> &Session;
440 fn lints(&self) -> &LintStore;
441 fn mut_lints(&mut self) -> &mut LintStore;
442 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)>;
443 fn enter_attrs(&mut self, attrs: &[ast::Attribute]);
444 fn exit_attrs(&mut self, attrs: &[ast::Attribute]);
446 /// Get the level of `lint` at the current position of the lint
448 fn current_level(&self, lint: &'static Lint) -> Level {
449 self.lints().levels.get(&LintId::of(lint)).map_or(Allow, |&(lvl, _)| lvl)
452 fn level_src(&self, lint: &'static Lint) -> Option<LevelSource> {
453 self.lints().levels.get(&LintId::of(lint)).map(|ls| match ls {
455 let lint_id = LintId::of(builtin::WARNINGS);
456 (self.lints().get_level_source(lint_id).0, src)
462 fn lookup_and_emit(&self, lint: &'static Lint, span: Option<Span>, msg: &str) {
463 let (level, src) = match self.level_src(lint) {
468 raw_emit_lint(&self.sess(), self.lints(), lint, (level, src), span, msg);
475 -> DiagnosticBuilder {
476 let (level, src) = match self.level_src(lint) {
477 None => return self.sess().diagnostic().struct_dummy(),
481 raw_struct_lint(&self.sess(), self.lints(), lint, (level, src), span, msg)
484 /// Emit a lint at the appropriate level, for a particular span.
485 fn span_lint(&self, lint: &'static Lint, span: Span, msg: &str) {
486 self.lookup_and_emit(lint, Some(span), msg);
489 fn struct_span_lint(&self,
493 -> DiagnosticBuilder {
494 self.lookup(lint, Some(span), msg)
497 /// Emit a lint and note at the appropriate level, for a particular span.
498 fn span_lint_note(&self, lint: &'static Lint, span: Span, msg: &str,
499 note_span: Span, note: &str) {
500 let mut err = self.lookup(lint, Some(span), msg);
501 if self.current_level(lint) != Level::Allow {
502 if note_span == span {
503 err.fileline_note(note_span, note);
505 err.span_note(note_span, note);
511 /// Emit a lint and help at the appropriate level, for a particular span.
512 fn span_lint_help(&self, lint: &'static Lint, span: Span,
513 msg: &str, help: &str) {
514 let mut err = self.lookup(lint, Some(span), msg);
515 self.span_lint(lint, span, msg);
516 if self.current_level(lint) != Level::Allow {
517 err.span_help(span, help);
522 /// Emit a lint at the appropriate level, with no associated span.
523 fn lint(&self, lint: &'static Lint, msg: &str) {
524 self.lookup_and_emit(lint, None, msg);
527 /// Merge the lints specified by any lint attributes into the
528 /// current lint context, call the provided function, then reset the
529 /// lints in effect to their previous state.
530 fn with_lint_attrs<F>(&mut self,
531 attrs: &[ast::Attribute],
533 where F: FnOnce(&mut Self),
535 // Parse all of the lint attributes, and then add them all to the
536 // current dictionary of lint information. Along the way, keep a history
537 // of what we changed so we can roll everything back after invoking the
541 for result in gather_attrs(attrs) {
542 let v = match result {
544 span_err!(self.sess(), span, E0452,
545 "malformed lint attribute");
548 Ok((lint_name, level, span)) => {
549 match self.lints().find_lint(&lint_name, &self.sess(), Some(span)) {
550 Ok(lint_id) => vec![(lint_id, level, span)],
551 Err(FindLintError::NotFound) => {
552 match self.lints().lint_groups.get(&lint_name[..]) {
553 Some(&(ref v, _)) => v.iter()
554 .map(|lint_id: &LintId|
555 (*lint_id, level, span))
558 self.span_lint(builtin::UNKNOWN_LINTS, span,
559 &format!("unknown `{}` attribute: `{}`",
560 level.as_str(), lint_name));
565 Err(FindLintError::Removed) => { continue; }
570 for (lint_id, level, span) in v {
571 let now = self.lints().get_level_source(lint_id).0;
572 if now == Forbid && level != Forbid {
573 let lint_name = lint_id.as_str();
574 span_err!(self.sess(), span, E0453,
575 "{}({}) overruled by outer forbid({})",
576 level.as_str(), lint_name,
578 } else if now != level {
579 let src = self.lints().get_level_source(lint_id).1;
580 self.level_stack().push((lint_id, (now, src)));
582 self.mut_lints().set_level(lint_id, (level, Node(span)));
587 self.enter_attrs(attrs);
589 self.exit_attrs(attrs);
593 let (lint, lvlsrc) = self.level_stack().pop().unwrap();
594 self.mut_lints().set_level(lint, lvlsrc);
600 impl<'a> EarlyContext<'a> {
601 fn new(sess: &'a Session,
602 krate: &'a ast::Crate) -> EarlyContext<'a> {
603 // We want to own the lint store, so move it out of the session. Remember
604 // to put it back later...
605 let lint_store = mem::replace(&mut *sess.lint_store.borrow_mut(),
615 fn visit_ids<F>(&mut self, f: F)
616 where F: FnOnce(&mut ast_util::IdVisitor<EarlyContext>)
618 let mut v = ast_util::IdVisitor {
620 visited_outermost: false,
626 impl<'a, 'tcx> LateContext<'a, 'tcx> {
627 fn new(tcx: &'a ty::ctxt<'tcx>,
628 krate: &'a hir::Crate,
629 access_levels: &'a AccessLevels) -> LateContext<'a, 'tcx> {
630 // We want to own the lint store, so move it out of the session.
631 let lint_store = mem::replace(&mut *tcx.sess.lint_store.borrow_mut(),
637 access_levels: access_levels,
640 node_levels: RefCell::new(FnvHashMap()),
644 fn visit_ids<F>(&mut self, f: F)
645 where F: FnOnce(&mut util::IdVisitor<LateContext>)
647 let mut v = util::IdVisitor::new(self);
652 impl<'a, 'tcx> LintContext for LateContext<'a, 'tcx> {
653 /// Get the overall compiler `Session` object.
654 fn sess(&self) -> &Session {
658 fn lints(&self) -> &LintStore {
662 fn mut_lints(&mut self) -> &mut LintStore {
666 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)> {
667 &mut self.level_stack
670 fn enter_attrs(&mut self, attrs: &[ast::Attribute]) {
671 debug!("late context: enter_attrs({:?})", attrs);
672 run_lints!(self, enter_lint_attrs, late_passes, attrs);
675 fn exit_attrs(&mut self, attrs: &[ast::Attribute]) {
676 debug!("late context: exit_attrs({:?})", attrs);
677 run_lints!(self, exit_lint_attrs, late_passes, attrs);
681 impl<'a> LintContext for EarlyContext<'a> {
682 /// Get the overall compiler `Session` object.
683 fn sess(&self) -> &Session {
687 fn lints(&self) -> &LintStore {
691 fn mut_lints(&mut self) -> &mut LintStore {
695 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)> {
696 &mut self.level_stack
699 fn enter_attrs(&mut self, attrs: &[ast::Attribute]) {
700 debug!("early context: exit_attrs({:?})", attrs);
701 run_lints!(self, enter_lint_attrs, early_passes, attrs);
704 fn exit_attrs(&mut self, attrs: &[ast::Attribute]) {
705 debug!("early context: exit_attrs({:?})", attrs);
706 run_lints!(self, exit_lint_attrs, early_passes, attrs);
710 impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
711 /// Because lints are scoped lexically, we want to walk nested
712 /// items in the context of the outer item, so enable
714 fn visit_nested_item(&mut self, item: hir::ItemId) {
715 self.visit_item(self.tcx.map.expect_item(item.id))
718 fn visit_item(&mut self, it: &hir::Item) {
719 self.with_lint_attrs(&it.attrs, |cx| {
720 run_lints!(cx, check_item, late_passes, it);
721 cx.visit_ids(|v| v.visit_item(it));
722 hir_visit::walk_item(cx, it);
726 fn visit_foreign_item(&mut self, it: &hir::ForeignItem) {
727 self.with_lint_attrs(&it.attrs, |cx| {
728 run_lints!(cx, check_foreign_item, late_passes, it);
729 hir_visit::walk_foreign_item(cx, it);
733 fn visit_pat(&mut self, p: &hir::Pat) {
734 run_lints!(self, check_pat, late_passes, p);
735 hir_visit::walk_pat(self, p);
738 fn visit_expr(&mut self, e: &hir::Expr) {
739 self.with_lint_attrs(e.attrs.as_attr_slice(), |cx| {
740 run_lints!(cx, check_expr, late_passes, e);
741 hir_visit::walk_expr(cx, e);
745 fn visit_stmt(&mut self, s: &hir::Stmt) {
746 // statement attributes are actually just attributes on one of
750 // so we keep track of lint levels there
751 run_lints!(self, check_stmt, late_passes, s);
752 hir_visit::walk_stmt(self, s);
755 fn visit_fn(&mut self, fk: hir_visit::FnKind<'v>, decl: &'v hir::FnDecl,
756 body: &'v hir::Block, span: Span, id: ast::NodeId) {
757 run_lints!(self, check_fn, late_passes, fk, decl, body, span, id);
758 hir_visit::walk_fn(self, fk, decl, body, span);
761 fn visit_variant_data(&mut self,
762 s: &hir::VariantData,
765 item_id: ast::NodeId,
767 run_lints!(self, check_struct_def, late_passes, s, name, g, item_id);
768 hir_visit::walk_struct_def(self, s);
769 run_lints!(self, check_struct_def_post, late_passes, s, name, g, item_id);
772 fn visit_struct_field(&mut self, s: &hir::StructField) {
773 self.with_lint_attrs(&s.node.attrs, |cx| {
774 run_lints!(cx, check_struct_field, late_passes, s);
775 hir_visit::walk_struct_field(cx, s);
779 fn visit_variant(&mut self, v: &hir::Variant, g: &hir::Generics, item_id: ast::NodeId) {
780 self.with_lint_attrs(&v.node.attrs, |cx| {
781 run_lints!(cx, check_variant, late_passes, v, g);
782 hir_visit::walk_variant(cx, v, g, item_id);
783 run_lints!(cx, check_variant_post, late_passes, v, g);
787 fn visit_ty(&mut self, t: &hir::Ty) {
788 run_lints!(self, check_ty, late_passes, t);
789 hir_visit::walk_ty(self, t);
792 fn visit_name(&mut self, sp: Span, name: ast::Name) {
793 run_lints!(self, check_name, late_passes, sp, name);
796 fn visit_mod(&mut self, m: &hir::Mod, s: Span, n: ast::NodeId) {
797 run_lints!(self, check_mod, late_passes, m, s, n);
798 hir_visit::walk_mod(self, m);
801 fn visit_local(&mut self, l: &hir::Local) {
802 self.with_lint_attrs(l.attrs.as_attr_slice(), |cx| {
803 run_lints!(cx, check_local, late_passes, l);
804 hir_visit::walk_local(cx, l);
808 fn visit_block(&mut self, b: &hir::Block) {
809 run_lints!(self, check_block, late_passes, b);
810 hir_visit::walk_block(self, b);
813 fn visit_arm(&mut self, a: &hir::Arm) {
814 run_lints!(self, check_arm, late_passes, a);
815 hir_visit::walk_arm(self, a);
818 fn visit_decl(&mut self, d: &hir::Decl) {
819 run_lints!(self, check_decl, late_passes, d);
820 hir_visit::walk_decl(self, d);
823 fn visit_expr_post(&mut self, e: &hir::Expr) {
824 run_lints!(self, check_expr_post, late_passes, e);
827 fn visit_generics(&mut self, g: &hir::Generics) {
828 run_lints!(self, check_generics, late_passes, g);
829 hir_visit::walk_generics(self, g);
832 fn visit_trait_item(&mut self, trait_item: &hir::TraitItem) {
833 self.with_lint_attrs(&trait_item.attrs, |cx| {
834 run_lints!(cx, check_trait_item, late_passes, trait_item);
835 cx.visit_ids(|v| v.visit_trait_item(trait_item));
836 hir_visit::walk_trait_item(cx, trait_item);
840 fn visit_impl_item(&mut self, impl_item: &hir::ImplItem) {
841 self.with_lint_attrs(&impl_item.attrs, |cx| {
842 run_lints!(cx, check_impl_item, late_passes, impl_item);
843 cx.visit_ids(|v| v.visit_impl_item(impl_item));
844 hir_visit::walk_impl_item(cx, impl_item);
848 fn visit_lifetime(&mut self, lt: &hir::Lifetime) {
849 run_lints!(self, check_lifetime, late_passes, lt);
852 fn visit_lifetime_def(&mut self, lt: &hir::LifetimeDef) {
853 run_lints!(self, check_lifetime_def, late_passes, lt);
856 fn visit_explicit_self(&mut self, es: &hir::ExplicitSelf) {
857 run_lints!(self, check_explicit_self, late_passes, es);
858 hir_visit::walk_explicit_self(self, es);
861 fn visit_path(&mut self, p: &hir::Path, id: ast::NodeId) {
862 run_lints!(self, check_path, late_passes, p, id);
863 hir_visit::walk_path(self, p);
866 fn visit_path_list_item(&mut self, prefix: &hir::Path, item: &hir::PathListItem) {
867 run_lints!(self, check_path_list_item, late_passes, item);
868 hir_visit::walk_path_list_item(self, prefix, item);
871 fn visit_attribute(&mut self, attr: &ast::Attribute) {
872 run_lints!(self, check_attribute, late_passes, attr);
876 impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
877 fn visit_item(&mut self, it: &ast::Item) {
878 self.with_lint_attrs(&it.attrs, |cx| {
879 run_lints!(cx, check_item, early_passes, it);
880 cx.visit_ids(|v| v.visit_item(it));
881 ast_visit::walk_item(cx, it);
885 fn visit_foreign_item(&mut self, it: &ast::ForeignItem) {
886 self.with_lint_attrs(&it.attrs, |cx| {
887 run_lints!(cx, check_foreign_item, early_passes, it);
888 ast_visit::walk_foreign_item(cx, it);
892 fn visit_pat(&mut self, p: &ast::Pat) {
893 run_lints!(self, check_pat, early_passes, p);
894 ast_visit::walk_pat(self, p);
897 fn visit_expr(&mut self, e: &ast::Expr) {
898 run_lints!(self, check_expr, early_passes, e);
899 ast_visit::walk_expr(self, e);
902 fn visit_stmt(&mut self, s: &ast::Stmt) {
903 run_lints!(self, check_stmt, early_passes, s);
904 ast_visit::walk_stmt(self, s);
907 fn visit_fn(&mut self, fk: ast_visit::FnKind<'v>, decl: &'v ast::FnDecl,
908 body: &'v ast::Block, span: Span, id: ast::NodeId) {
909 run_lints!(self, check_fn, early_passes, fk, decl, body, span, id);
910 ast_visit::walk_fn(self, fk, decl, body, span);
913 fn visit_variant_data(&mut self,
914 s: &ast::VariantData,
917 item_id: ast::NodeId,
919 run_lints!(self, check_struct_def, early_passes, s, ident, g, item_id);
920 ast_visit::walk_struct_def(self, s);
921 run_lints!(self, check_struct_def_post, early_passes, s, ident, g, item_id);
924 fn visit_struct_field(&mut self, s: &ast::StructField) {
925 self.with_lint_attrs(&s.node.attrs, |cx| {
926 run_lints!(cx, check_struct_field, early_passes, s);
927 ast_visit::walk_struct_field(cx, s);
931 fn visit_variant(&mut self, v: &ast::Variant, g: &ast::Generics, item_id: ast::NodeId) {
932 self.with_lint_attrs(&v.node.attrs, |cx| {
933 run_lints!(cx, check_variant, early_passes, v, g);
934 ast_visit::walk_variant(cx, v, g, item_id);
935 run_lints!(cx, check_variant_post, early_passes, v, g);
939 fn visit_ty(&mut self, t: &ast::Ty) {
940 run_lints!(self, check_ty, early_passes, t);
941 ast_visit::walk_ty(self, t);
944 fn visit_ident(&mut self, sp: Span, id: ast::Ident) {
945 run_lints!(self, check_ident, early_passes, sp, id);
948 fn visit_mod(&mut self, m: &ast::Mod, s: Span, n: ast::NodeId) {
949 run_lints!(self, check_mod, early_passes, m, s, n);
950 ast_visit::walk_mod(self, m);
953 fn visit_local(&mut self, l: &ast::Local) {
954 run_lints!(self, check_local, early_passes, l);
955 ast_visit::walk_local(self, l);
958 fn visit_block(&mut self, b: &ast::Block) {
959 run_lints!(self, check_block, early_passes, b);
960 ast_visit::walk_block(self, b);
963 fn visit_arm(&mut self, a: &ast::Arm) {
964 run_lints!(self, check_arm, early_passes, a);
965 ast_visit::walk_arm(self, a);
968 fn visit_decl(&mut self, d: &ast::Decl) {
969 run_lints!(self, check_decl, early_passes, d);
970 ast_visit::walk_decl(self, d);
973 fn visit_expr_post(&mut self, e: &ast::Expr) {
974 run_lints!(self, check_expr_post, early_passes, e);
977 fn visit_generics(&mut self, g: &ast::Generics) {
978 run_lints!(self, check_generics, early_passes, g);
979 ast_visit::walk_generics(self, g);
982 fn visit_trait_item(&mut self, trait_item: &ast::TraitItem) {
983 self.with_lint_attrs(&trait_item.attrs, |cx| {
984 run_lints!(cx, check_trait_item, early_passes, trait_item);
985 cx.visit_ids(|v| v.visit_trait_item(trait_item));
986 ast_visit::walk_trait_item(cx, trait_item);
990 fn visit_impl_item(&mut self, impl_item: &ast::ImplItem) {
991 self.with_lint_attrs(&impl_item.attrs, |cx| {
992 run_lints!(cx, check_impl_item, early_passes, impl_item);
993 cx.visit_ids(|v| v.visit_impl_item(impl_item));
994 ast_visit::walk_impl_item(cx, impl_item);
998 fn visit_lifetime(&mut self, lt: &ast::Lifetime) {
999 run_lints!(self, check_lifetime, early_passes, lt);
1002 fn visit_lifetime_def(&mut self, lt: &ast::LifetimeDef) {
1003 run_lints!(self, check_lifetime_def, early_passes, lt);
1006 fn visit_explicit_self(&mut self, es: &ast::ExplicitSelf) {
1007 run_lints!(self, check_explicit_self, early_passes, es);
1008 ast_visit::walk_explicit_self(self, es);
1011 fn visit_path(&mut self, p: &ast::Path, id: ast::NodeId) {
1012 run_lints!(self, check_path, early_passes, p, id);
1013 ast_visit::walk_path(self, p);
1016 fn visit_path_list_item(&mut self, prefix: &ast::Path, item: &ast::PathListItem) {
1017 run_lints!(self, check_path_list_item, early_passes, item);
1018 ast_visit::walk_path_list_item(self, prefix, item);
1021 fn visit_attribute(&mut self, attr: &ast::Attribute) {
1022 run_lints!(self, check_attribute, early_passes, attr);
1026 // Output any lints that were previously added to the session.
1027 impl<'a, 'tcx> IdVisitingOperation for LateContext<'a, 'tcx> {
1028 fn visit_id(&mut self, id: ast::NodeId) {
1029 match self.sess().lints.borrow_mut().remove(&id) {
1032 debug!("LateContext::visit_id: id={:?} lints={:?}", id, lints);
1033 for (lint_id, span, msg) in lints {
1034 self.span_lint(lint_id.lint, span, &msg[..])
1040 impl<'a> IdVisitingOperation for EarlyContext<'a> {
1041 fn visit_id(&mut self, id: ast::NodeId) {
1042 match self.sess.lints.borrow_mut().remove(&id) {
1045 for (lint_id, span, msg) in lints {
1046 self.span_lint(lint_id.lint, span, &msg[..])
1053 // This lint pass is defined here because it touches parts of the `LateContext`
1054 // that we don't want to expose. It records the lint level at certain AST
1055 // nodes, so that the variant size difference check in trans can call
1058 pub struct GatherNodeLevels;
1060 impl LintPass for GatherNodeLevels {
1061 fn get_lints(&self) -> LintArray {
1066 impl LateLintPass for GatherNodeLevels {
1067 fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
1069 hir::ItemEnum(..) => {
1070 let lint_id = LintId::of(builtin::VARIANT_SIZE_DIFFERENCES);
1071 let lvlsrc = cx.lints.get_level_source(lint_id);
1073 (lvl, _) if lvl != Allow => {
1074 cx.node_levels.borrow_mut()
1075 .insert((it.id, lint_id), lvlsrc);
1085 /// Perform lint checking on a crate.
1087 /// Consumes the `lint_store` field of the `Session`.
1088 pub fn check_crate(tcx: &ty::ctxt, access_levels: &AccessLevels) {
1089 let _task = tcx.dep_graph.in_task(DepNode::LateLintCheck);
1091 let krate = tcx.map.krate();
1092 let mut cx = LateContext::new(tcx, krate, access_levels);
1094 // Visit the whole crate.
1095 cx.with_lint_attrs(&krate.attrs, |cx| {
1096 cx.visit_id(ast::CRATE_NODE_ID);
1098 hir_visit::walk_crate(v, krate);
1101 // since the root module isn't visited as an item (because it isn't an
1102 // item), warn for it here.
1103 run_lints!(cx, check_crate, late_passes, krate);
1105 hir_visit::walk_crate(cx, krate);
1108 // If we missed any lints added to the session, then there's a bug somewhere
1109 // in the iteration code.
1110 for (id, v) in tcx.sess.lints.borrow().iter() {
1111 for &(lint, span, ref msg) in v {
1112 tcx.sess.span_bug(span,
1113 &format!("unprocessed lint {} at {}: {}",
1114 lint.as_str(), tcx.map.node_to_string(*id), *msg))
1118 *tcx.node_lint_levels.borrow_mut() = cx.node_levels.into_inner();
1121 pub fn check_ast_crate(sess: &Session, krate: &ast::Crate) {
1122 let mut cx = EarlyContext::new(sess, krate);
1124 // Visit the whole crate.
1125 cx.with_lint_attrs(&krate.attrs, |cx| {
1126 cx.visit_id(ast::CRATE_NODE_ID);
1128 v.visited_outermost = true;
1129 ast_visit::walk_crate(v, krate);
1132 // since the root module isn't visited as an item (because it isn't an
1133 // item), warn for it here.
1134 run_lints!(cx, check_crate, early_passes, krate);
1136 ast_visit::walk_crate(cx, krate);
1139 // Put the lint store back in the session.
1140 mem::replace(&mut *sess.lint_store.borrow_mut(), cx.lints);
1142 // If we missed any lints added to the session, then there's a bug somewhere
1143 // in the iteration code.
1144 for (_, v) in sess.lints.borrow().iter() {
1145 for &(lint, span, ref msg) in v {
1147 &format!("unprocessed lint {}: {}",
1148 lint.as_str(), *msg))