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 middle::privacy::AccessLevels;
30 use session::{early_error, Session};
31 use lint::{Level, LevelSource, Lint, LintId, LintArray, LintPass};
32 use lint::{EarlyLintPass, EarlyLintPassObject, LateLintPass, LateLintPassObject};
33 use lint::{Default, CommandLine, Node, Allow, Warn, Deny, Forbid};
35 use util::nodemap::FnvHashMap;
37 use std::cell::RefCell;
40 use syntax::ast_util::{self, IdVisitingOperation};
41 use syntax::attr::{self, AttrMetaMethods};
42 use syntax::codemap::Span;
43 use syntax::parse::token::InternedString;
45 use syntax::attr::ThinAttributesExt;
47 use rustc_front::util;
48 use rustc_front::intravisit as hir_visit;
49 use syntax::visit as ast_visit;
50 use syntax::diagnostic;
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 iterating over the objects. See the definition
64 early_passes: Option<Vec<EarlyLintPassObject>>,
65 late_passes: Option<Vec<LateLintPassObject>>,
67 /// Lints indexed by name.
68 by_name: FnvHashMap<String, TargetLint>,
70 /// Current levels of each lint, and where they were set.
71 levels: FnvHashMap<LintId, LevelSource>,
73 /// Map of registered lint groups to what lints they expand to. The bool
74 /// is true if the lint group was added by a plugin.
75 lint_groups: FnvHashMap<&'static str, (Vec<LintId>, bool)>,
77 /// Maximum level a lint can be
78 lint_cap: Option<Level>,
81 /// The targed of the `by_name` map, which accounts for renaming/deprecation.
83 /// A direct lint target
86 /// Temporary renaming, used for easing migration pain; see #16545
87 Renamed(String, LintId),
89 /// Lint with this name existed previously, but has been removed/deprecated.
90 /// The string argument is the reason for removal.
100 fn get_level_source(&self, lint: LintId) -> LevelSource {
101 match self.levels.get(&lint) {
103 None => (Allow, Default),
107 fn set_level(&mut self, lint: LintId, mut lvlsrc: LevelSource) {
108 if let Some(cap) = self.lint_cap {
109 lvlsrc.0 = cmp::min(lvlsrc.0, cap);
111 if lvlsrc.0 == Allow {
112 self.levels.remove(&lint);
114 self.levels.insert(lint, lvlsrc);
118 pub fn new() -> LintStore {
121 early_passes: Some(vec!()),
122 late_passes: Some(vec!()),
123 by_name: FnvHashMap(),
124 levels: FnvHashMap(),
125 lint_groups: FnvHashMap(),
130 pub fn get_lints<'t>(&'t self) -> &'t [(&'static Lint, bool)] {
134 pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
135 self.lint_groups.iter().map(|(k, v)| (*k,
140 pub fn register_early_pass(&mut self,
141 sess: Option<&Session>,
143 pass: EarlyLintPassObject) {
144 self.push_pass(sess, from_plugin, &pass);
145 self.early_passes.as_mut().unwrap().push(pass);
148 pub fn register_late_pass(&mut self,
149 sess: Option<&Session>,
151 pass: LateLintPassObject) {
152 self.push_pass(sess, from_plugin, &pass);
153 self.late_passes.as_mut().unwrap().push(pass);
156 // Helper method for register_early/late_pass
157 fn push_pass<P: LintPass + ?Sized + 'static>(&mut self,
158 sess: Option<&Session>,
161 for &lint in pass.get_lints() {
162 self.lints.push((*lint, from_plugin));
164 let id = LintId::of(*lint);
165 if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
166 let msg = format!("duplicate specification of lint {}", lint.name_lower());
167 match (sess, from_plugin) {
168 // We load builtin lints first, so a duplicate is a compiler bug.
169 // Use early_error when handling -W help with no crate.
170 (None, _) => early_error(diagnostic::Auto, &msg[..]),
171 (Some(sess), false) => sess.bug(&msg[..]),
173 // A duplicate name from a plugin is a user error.
174 (Some(sess), true) => sess.err(&msg[..]),
178 if lint.default_level != Allow {
179 self.levels.insert(id, (lint.default_level, Default));
184 pub fn register_group(&mut self, sess: Option<&Session>,
185 from_plugin: bool, name: &'static str,
187 let new = self.lint_groups.insert(name, (to, from_plugin)).is_none();
190 let msg = format!("duplicate specification of lint group {}", name);
191 match (sess, from_plugin) {
192 // We load builtin lints first, so a duplicate is a compiler bug.
193 // Use early_error when handling -W help with no crate.
194 (None, _) => early_error(diagnostic::Auto, &msg[..]),
195 (Some(sess), false) => sess.bug(&msg[..]),
197 // A duplicate name from a plugin is a user error.
198 (Some(sess), true) => sess.err(&msg[..]),
203 pub fn register_renamed(&mut self, old_name: &str, new_name: &str) {
204 let target = match self.by_name.get(new_name) {
205 Some(&Id(lint_id)) => lint_id.clone(),
206 _ => panic!("invalid lint renaming of {} to {}", old_name, new_name)
208 self.by_name.insert(old_name.to_string(), Renamed(new_name.to_string(), target));
211 pub fn register_removed(&mut self, name: &str, reason: &str) {
212 self.by_name.insert(name.into(), Removed(reason.into()));
215 #[allow(unused_variables)]
216 fn find_lint(&self, lint_name: &str, sess: &Session, span: Option<Span>)
217 -> Result<LintId, FindLintError>
219 match self.by_name.get(lint_name) {
220 Some(&Id(lint_id)) => Ok(lint_id),
221 Some(&Renamed(ref new_name, lint_id)) => {
222 let warning = format!("lint {} has been renamed to {}",
223 lint_name, new_name);
225 Some(span) => sess.span_warn(span, &warning[..]),
226 None => sess.warn(&warning[..]),
230 Some(&Removed(ref reason)) => {
231 let warning = format!("lint {} has been removed: {}", lint_name, reason);
233 Some(span) => sess.span_warn(span, &warning[..]),
234 None => sess.warn(&warning[..])
236 Err(FindLintError::Removed)
238 None => Err(FindLintError::NotFound)
242 pub fn process_command_line(&mut self, sess: &Session) {
243 for &(ref lint_name, level) in &sess.opts.lint_opts {
244 match self.find_lint(&lint_name[..], sess, None) {
245 Ok(lint_id) => self.set_level(lint_id, (level, CommandLine)),
247 match self.lint_groups.iter().map(|(&x, pair)| (x, pair.0.clone()))
248 .collect::<FnvHashMap<&'static str,
250 .get(&lint_name[..]) {
253 .map(|lint_id: &LintId|
254 self.set_level(*lint_id, (level, CommandLine)))
255 .collect::<Vec<()>>();
257 None => sess.err(&format!("unknown {} flag: {}",
258 level.as_str(), lint_name)),
264 self.lint_cap = sess.opts.lint_cap;
265 if let Some(cap) = self.lint_cap {
266 for level in self.levels.iter_mut().map(|p| &mut (p.1).0) {
267 *level = cmp::min(*level, cap);
273 /// Context for lint checking after type checking.
274 pub struct LateContext<'a, 'tcx: 'a> {
275 /// Type context we're checking in.
276 pub tcx: &'a ty::ctxt<'tcx>,
278 /// The crate being checked.
279 pub krate: &'a hir::Crate,
281 /// Items accessible from the crate being checked.
282 pub access_levels: &'a AccessLevels,
284 /// The store of registered lints.
287 /// When recursing into an attributed node of the ast which modifies lint
288 /// levels, this stack keeps track of the previous lint levels of whatever
290 level_stack: Vec<(LintId, LevelSource)>,
292 /// Level of lints for certain NodeIds, stored here because the body of
293 /// the lint needs to run in trans.
294 node_levels: RefCell<FnvHashMap<(ast::NodeId, LintId), LevelSource>>,
297 /// Context for lint checking of the AST, after expansion, before lowering to
299 pub struct EarlyContext<'a> {
300 /// Type context we're checking in.
301 pub sess: &'a Session,
303 /// The crate being checked.
304 pub krate: &'a ast::Crate,
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 /// Convenience macro for calling a `LintPass` method on every pass in the context.
316 macro_rules! run_lints { ($cx:expr, $f:ident, $ps:ident, $($args:expr),*) => ({
317 // Move the vector of passes out of `$cx` so that we can
318 // iterate over it mutably while passing `$cx` to the methods.
319 let mut passes = $cx.mut_lints().$ps.take().unwrap();
320 for obj in &mut passes {
321 obj.$f($cx, $($args),*);
323 $cx.mut_lints().$ps = Some(passes);
326 /// Parse the lint attributes into a vector, with `Err`s for malformed lint
327 /// attributes. Writing this as an iterator is an enormous mess.
328 // See also the hir version just below.
329 pub fn gather_attrs(attrs: &[ast::Attribute])
330 -> Vec<Result<(InternedString, Level, Span), Span>> {
331 let mut out = vec!();
333 let level = match Level::from_str(&attr.name()) {
338 attr::mark_used(attr);
340 let meta = &attr.node.value;
341 let metas = match meta.node {
342 ast::MetaList(_, ref metas) => metas,
344 out.push(Err(meta.span));
350 out.push(match meta.node {
351 ast::MetaWord(ref lint_name) => Ok((lint_name.clone(), level, meta.span)),
359 /// Emit a lint as a warning or an error (or not at all)
360 /// according to `level`.
362 /// This lives outside of `Context` so it can be used by checks
363 /// in trans that run after the main lint pass is finished. Most
364 /// lints elsewhere in the compiler should call
365 /// `Session::add_lint()` instead.
366 pub fn raw_emit_lint(sess: &Session, lint: &'static Lint,
367 lvlsrc: LevelSource, span: Option<Span>, msg: &str) {
368 let (mut level, source) = lvlsrc;
369 if level == Allow { return }
371 let name = lint.name_lower();
373 let msg = match source {
375 format!("{}, #[{}({})] on by default", msg,
376 level.as_str(), name)
379 format!("{} [-{} {}]", msg,
381 Warn => 'W', Deny => 'D', Forbid => 'F',
383 }, name.replace("_", "-"))
391 // For purposes of printing, we can treat forbid as deny.
392 if level == Forbid { level = Deny; }
394 match (level, span) {
395 (Warn, Some(sp)) => sess.span_warn(sp, &msg[..]),
396 (Warn, None) => sess.warn(&msg[..]),
397 (Deny, Some(sp)) => sess.span_err(sp, &msg[..]),
398 (Deny, None) => sess.err(&msg[..]),
399 _ => sess.bug("impossible level in raw_emit_lint"),
402 if let Some(span) = def {
403 sess.span_note(span, "lint level defined here");
407 pub trait LintContext: Sized {
408 fn sess(&self) -> &Session;
409 fn lints(&self) -> &LintStore;
410 fn mut_lints(&mut self) -> &mut LintStore;
411 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)>;
412 fn enter_attrs(&mut self, attrs: &[ast::Attribute]);
413 fn exit_attrs(&mut self, attrs: &[ast::Attribute]);
415 /// Get the level of `lint` at the current position of the lint
417 fn current_level(&self, lint: &'static Lint) -> Level {
418 self.lints().levels.get(&LintId::of(lint)).map_or(Allow, |&(lvl, _)| lvl)
421 fn lookup_and_emit(&self, lint: &'static Lint, span: Option<Span>, msg: &str) {
422 let (level, src) = match self.lints().levels.get(&LintId::of(lint)) {
424 Some(&(Warn, src)) => {
425 let lint_id = LintId::of(builtin::WARNINGS);
426 (self.lints().get_level_source(lint_id).0, src)
431 raw_emit_lint(&self.sess(), lint, (level, src), span, msg);
434 /// Emit a lint at the appropriate level, for a particular span.
435 fn span_lint(&self, lint: &'static Lint, span: Span, msg: &str) {
436 self.lookup_and_emit(lint, Some(span), msg);
439 /// Emit a lint and note at the appropriate level, for a particular span.
440 fn span_lint_note(&self, lint: &'static Lint, span: Span, msg: &str,
441 note_span: Span, note: &str) {
442 self.span_lint(lint, span, msg);
443 if self.current_level(lint) != Level::Allow {
444 if note_span == span {
445 self.sess().fileline_note(note_span, note)
447 self.sess().span_note(note_span, note)
452 /// Emit a lint and help at the appropriate level, for a particular span.
453 fn span_lint_help(&self, lint: &'static Lint, span: Span,
454 msg: &str, help: &str) {
455 self.span_lint(lint, span, msg);
456 if self.current_level(lint) != Level::Allow {
457 self.sess().span_help(span, help)
461 /// Emit a lint at the appropriate level, with no associated span.
462 fn lint(&self, lint: &'static Lint, msg: &str) {
463 self.lookup_and_emit(lint, None, msg);
466 /// Merge the lints specified by any lint attributes into the
467 /// current lint context, call the provided function, then reset the
468 /// lints in effect to their previous state.
469 fn with_lint_attrs<F>(&mut self,
470 attrs: &[ast::Attribute],
472 where F: FnOnce(&mut Self),
474 // Parse all of the lint attributes, and then add them all to the
475 // current dictionary of lint information. Along the way, keep a history
476 // of what we changed so we can roll everything back after invoking the
480 for result in gather_attrs(attrs) {
481 let v = match result {
483 span_err!(self.sess(), span, E0452,
484 "malformed lint attribute");
487 Ok((lint_name, level, span)) => {
488 match self.lints().find_lint(&lint_name, &self.sess(), Some(span)) {
489 Ok(lint_id) => vec![(lint_id, level, span)],
490 Err(FindLintError::NotFound) => {
491 match self.lints().lint_groups.get(&lint_name[..]) {
492 Some(&(ref v, _)) => v.iter()
493 .map(|lint_id: &LintId|
494 (*lint_id, level, span))
497 self.span_lint(builtin::UNKNOWN_LINTS, span,
498 &format!("unknown `{}` attribute: `{}`",
499 level.as_str(), lint_name));
504 Err(FindLintError::Removed) => { continue; }
509 for (lint_id, level, span) in v {
510 let now = self.lints().get_level_source(lint_id).0;
511 if now == Forbid && level != Forbid {
512 let lint_name = lint_id.as_str();
513 span_err!(self.sess(), span, E0453,
514 "{}({}) overruled by outer forbid({})",
515 level.as_str(), lint_name,
517 } else if now != level {
518 let src = self.lints().get_level_source(lint_id).1;
519 self.level_stack().push((lint_id, (now, src)));
521 self.mut_lints().set_level(lint_id, (level, Node(span)));
526 self.enter_attrs(attrs);
528 self.exit_attrs(attrs);
532 let (lint, lvlsrc) = self.level_stack().pop().unwrap();
533 self.mut_lints().set_level(lint, lvlsrc);
539 impl<'a> EarlyContext<'a> {
540 fn new(sess: &'a Session,
541 krate: &'a ast::Crate) -> EarlyContext<'a> {
542 // We want to own the lint store, so move it out of the session. Remember
543 // to put it back later...
544 let lint_store = mem::replace(&mut *sess.lint_store.borrow_mut(),
554 fn visit_ids<F>(&mut self, f: F)
555 where F: FnOnce(&mut ast_util::IdVisitor<EarlyContext>)
557 let mut v = ast_util::IdVisitor {
559 visited_outermost: false,
565 impl<'a, 'tcx> LateContext<'a, 'tcx> {
566 fn new(tcx: &'a ty::ctxt<'tcx>,
567 krate: &'a hir::Crate,
568 access_levels: &'a AccessLevels) -> LateContext<'a, 'tcx> {
569 // We want to own the lint store, so move it out of the session.
570 let lint_store = mem::replace(&mut *tcx.sess.lint_store.borrow_mut(),
576 access_levels: access_levels,
579 node_levels: RefCell::new(FnvHashMap()),
583 fn visit_ids<F>(&mut self, f: F)
584 where F: FnOnce(&mut util::IdVisitor<LateContext>)
586 let mut v = util::IdVisitor::new(self);
591 impl<'a, 'tcx> LintContext for LateContext<'a, 'tcx> {
592 /// Get the overall compiler `Session` object.
593 fn sess(&self) -> &Session {
597 fn lints(&self) -> &LintStore {
601 fn mut_lints(&mut self) -> &mut LintStore {
605 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)> {
606 &mut self.level_stack
609 fn enter_attrs(&mut self, attrs: &[ast::Attribute]) {
610 debug!("late context: enter_attrs({:?})", attrs);
611 run_lints!(self, enter_lint_attrs, late_passes, attrs);
614 fn exit_attrs(&mut self, attrs: &[ast::Attribute]) {
615 debug!("late context: exit_attrs({:?})", attrs);
616 run_lints!(self, exit_lint_attrs, late_passes, attrs);
620 impl<'a> LintContext for EarlyContext<'a> {
621 /// Get the overall compiler `Session` object.
622 fn sess(&self) -> &Session {
626 fn lints(&self) -> &LintStore {
630 fn mut_lints(&mut self) -> &mut LintStore {
634 fn level_stack(&mut self) -> &mut Vec<(LintId, LevelSource)> {
635 &mut self.level_stack
638 fn enter_attrs(&mut self, attrs: &[ast::Attribute]) {
639 debug!("early context: exit_attrs({:?})", attrs);
640 run_lints!(self, enter_lint_attrs, early_passes, attrs);
643 fn exit_attrs(&mut self, attrs: &[ast::Attribute]) {
644 debug!("early context: exit_attrs({:?})", attrs);
645 run_lints!(self, exit_lint_attrs, early_passes, attrs);
649 impl<'a, 'tcx, 'v> hir_visit::Visitor<'v> for LateContext<'a, 'tcx> {
650 /// Because lints are scoped lexically, we want to walk nested
651 /// items in the context of the outer item, so enable
653 fn visit_nested_item(&mut self, item: hir::ItemId) {
654 self.visit_item(self.tcx.map.expect_item(item.id))
657 fn visit_item(&mut self, it: &hir::Item) {
658 self.with_lint_attrs(&it.attrs, |cx| {
659 run_lints!(cx, check_item, late_passes, it);
660 cx.visit_ids(|v| v.visit_item(it));
661 hir_visit::walk_item(cx, it);
665 fn visit_foreign_item(&mut self, it: &hir::ForeignItem) {
666 self.with_lint_attrs(&it.attrs, |cx| {
667 run_lints!(cx, check_foreign_item, late_passes, it);
668 hir_visit::walk_foreign_item(cx, it);
672 fn visit_pat(&mut self, p: &hir::Pat) {
673 run_lints!(self, check_pat, late_passes, p);
674 hir_visit::walk_pat(self, p);
677 fn visit_expr(&mut self, e: &hir::Expr) {
678 self.with_lint_attrs(e.attrs.as_attr_slice(), |cx| {
679 run_lints!(cx, check_expr, late_passes, e);
680 hir_visit::walk_expr(cx, e);
684 fn visit_stmt(&mut self, s: &hir::Stmt) {
685 // statement attributes are actually just attributes on one of
689 // so we keep track of lint levels there
690 run_lints!(self, check_stmt, late_passes, s);
691 hir_visit::walk_stmt(self, s);
694 fn visit_fn(&mut self, fk: hir_visit::FnKind<'v>, decl: &'v hir::FnDecl,
695 body: &'v hir::Block, span: Span, id: ast::NodeId) {
696 run_lints!(self, check_fn, late_passes, fk, decl, body, span, id);
697 hir_visit::walk_fn(self, fk, decl, body, span);
700 fn visit_variant_data(&mut self,
701 s: &hir::VariantData,
704 item_id: ast::NodeId,
706 run_lints!(self, check_struct_def, late_passes, s, name, g, item_id);
707 hir_visit::walk_struct_def(self, s);
708 run_lints!(self, check_struct_def_post, late_passes, s, name, g, item_id);
711 fn visit_struct_field(&mut self, s: &hir::StructField) {
712 self.with_lint_attrs(&s.node.attrs, |cx| {
713 run_lints!(cx, check_struct_field, late_passes, s);
714 hir_visit::walk_struct_field(cx, s);
718 fn visit_variant(&mut self, v: &hir::Variant, g: &hir::Generics, item_id: ast::NodeId) {
719 self.with_lint_attrs(&v.node.attrs, |cx| {
720 run_lints!(cx, check_variant, late_passes, v, g);
721 hir_visit::walk_variant(cx, v, g, item_id);
722 run_lints!(cx, check_variant_post, late_passes, v, g);
726 fn visit_ty(&mut self, t: &hir::Ty) {
727 run_lints!(self, check_ty, late_passes, t);
728 hir_visit::walk_ty(self, t);
731 fn visit_name(&mut self, sp: Span, name: ast::Name) {
732 run_lints!(self, check_name, late_passes, sp, name);
735 fn visit_mod(&mut self, m: &hir::Mod, s: Span, n: ast::NodeId) {
736 run_lints!(self, check_mod, late_passes, m, s, n);
737 hir_visit::walk_mod(self, m);
740 fn visit_local(&mut self, l: &hir::Local) {
741 self.with_lint_attrs(l.attrs.as_attr_slice(), |cx| {
742 run_lints!(cx, check_local, late_passes, l);
743 hir_visit::walk_local(cx, l);
747 fn visit_block(&mut self, b: &hir::Block) {
748 run_lints!(self, check_block, late_passes, b);
749 hir_visit::walk_block(self, b);
752 fn visit_arm(&mut self, a: &hir::Arm) {
753 run_lints!(self, check_arm, late_passes, a);
754 hir_visit::walk_arm(self, a);
757 fn visit_decl(&mut self, d: &hir::Decl) {
758 run_lints!(self, check_decl, late_passes, d);
759 hir_visit::walk_decl(self, d);
762 fn visit_expr_post(&mut self, e: &hir::Expr) {
763 run_lints!(self, check_expr_post, late_passes, e);
766 fn visit_generics(&mut self, g: &hir::Generics) {
767 run_lints!(self, check_generics, late_passes, g);
768 hir_visit::walk_generics(self, g);
771 fn visit_trait_item(&mut self, trait_item: &hir::TraitItem) {
772 self.with_lint_attrs(&trait_item.attrs, |cx| {
773 run_lints!(cx, check_trait_item, late_passes, trait_item);
774 cx.visit_ids(|v| v.visit_trait_item(trait_item));
775 hir_visit::walk_trait_item(cx, trait_item);
779 fn visit_impl_item(&mut self, impl_item: &hir::ImplItem) {
780 self.with_lint_attrs(&impl_item.attrs, |cx| {
781 run_lints!(cx, check_impl_item, late_passes, impl_item);
782 cx.visit_ids(|v| v.visit_impl_item(impl_item));
783 hir_visit::walk_impl_item(cx, impl_item);
787 fn visit_lifetime(&mut self, lt: &hir::Lifetime) {
788 run_lints!(self, check_lifetime, late_passes, lt);
791 fn visit_lifetime_def(&mut self, lt: &hir::LifetimeDef) {
792 run_lints!(self, check_lifetime_def, late_passes, lt);
795 fn visit_explicit_self(&mut self, es: &hir::ExplicitSelf) {
796 run_lints!(self, check_explicit_self, late_passes, es);
797 hir_visit::walk_explicit_self(self, es);
800 fn visit_path(&mut self, p: &hir::Path, id: ast::NodeId) {
801 run_lints!(self, check_path, late_passes, p, id);
802 hir_visit::walk_path(self, p);
805 fn visit_path_list_item(&mut self, prefix: &hir::Path, item: &hir::PathListItem) {
806 run_lints!(self, check_path_list_item, late_passes, item);
807 hir_visit::walk_path_list_item(self, prefix, item);
810 fn visit_attribute(&mut self, attr: &ast::Attribute) {
811 run_lints!(self, check_attribute, late_passes, attr);
815 impl<'a, 'v> ast_visit::Visitor<'v> for EarlyContext<'a> {
816 fn visit_item(&mut self, it: &ast::Item) {
817 self.with_lint_attrs(&it.attrs, |cx| {
818 run_lints!(cx, check_item, early_passes, it);
819 cx.visit_ids(|v| v.visit_item(it));
820 ast_visit::walk_item(cx, it);
824 fn visit_foreign_item(&mut self, it: &ast::ForeignItem) {
825 self.with_lint_attrs(&it.attrs, |cx| {
826 run_lints!(cx, check_foreign_item, early_passes, it);
827 ast_visit::walk_foreign_item(cx, it);
831 fn visit_pat(&mut self, p: &ast::Pat) {
832 run_lints!(self, check_pat, early_passes, p);
833 ast_visit::walk_pat(self, p);
836 fn visit_expr(&mut self, e: &ast::Expr) {
837 run_lints!(self, check_expr, early_passes, e);
838 ast_visit::walk_expr(self, e);
841 fn visit_stmt(&mut self, s: &ast::Stmt) {
842 run_lints!(self, check_stmt, early_passes, s);
843 ast_visit::walk_stmt(self, s);
846 fn visit_fn(&mut self, fk: ast_visit::FnKind<'v>, decl: &'v ast::FnDecl,
847 body: &'v ast::Block, span: Span, id: ast::NodeId) {
848 run_lints!(self, check_fn, early_passes, fk, decl, body, span, id);
849 ast_visit::walk_fn(self, fk, decl, body, span);
852 fn visit_variant_data(&mut self,
853 s: &ast::VariantData,
856 item_id: ast::NodeId,
858 run_lints!(self, check_struct_def, early_passes, s, ident, g, item_id);
859 ast_visit::walk_struct_def(self, s);
860 run_lints!(self, check_struct_def_post, early_passes, s, ident, g, item_id);
863 fn visit_struct_field(&mut self, s: &ast::StructField) {
864 self.with_lint_attrs(&s.node.attrs, |cx| {
865 run_lints!(cx, check_struct_field, early_passes, s);
866 ast_visit::walk_struct_field(cx, s);
870 fn visit_variant(&mut self, v: &ast::Variant, g: &ast::Generics, item_id: ast::NodeId) {
871 self.with_lint_attrs(&v.node.attrs, |cx| {
872 run_lints!(cx, check_variant, early_passes, v, g);
873 ast_visit::walk_variant(cx, v, g, item_id);
874 run_lints!(cx, check_variant_post, early_passes, v, g);
878 fn visit_ty(&mut self, t: &ast::Ty) {
879 run_lints!(self, check_ty, early_passes, t);
880 ast_visit::walk_ty(self, t);
883 fn visit_ident(&mut self, sp: Span, id: ast::Ident) {
884 run_lints!(self, check_ident, early_passes, sp, id);
887 fn visit_mod(&mut self, m: &ast::Mod, s: Span, n: ast::NodeId) {
888 run_lints!(self, check_mod, early_passes, m, s, n);
889 ast_visit::walk_mod(self, m);
892 fn visit_local(&mut self, l: &ast::Local) {
893 run_lints!(self, check_local, early_passes, l);
894 ast_visit::walk_local(self, l);
897 fn visit_block(&mut self, b: &ast::Block) {
898 run_lints!(self, check_block, early_passes, b);
899 ast_visit::walk_block(self, b);
902 fn visit_arm(&mut self, a: &ast::Arm) {
903 run_lints!(self, check_arm, early_passes, a);
904 ast_visit::walk_arm(self, a);
907 fn visit_decl(&mut self, d: &ast::Decl) {
908 run_lints!(self, check_decl, early_passes, d);
909 ast_visit::walk_decl(self, d);
912 fn visit_expr_post(&mut self, e: &ast::Expr) {
913 run_lints!(self, check_expr_post, early_passes, e);
916 fn visit_generics(&mut self, g: &ast::Generics) {
917 run_lints!(self, check_generics, early_passes, g);
918 ast_visit::walk_generics(self, g);
921 fn visit_trait_item(&mut self, trait_item: &ast::TraitItem) {
922 self.with_lint_attrs(&trait_item.attrs, |cx| {
923 run_lints!(cx, check_trait_item, early_passes, trait_item);
924 cx.visit_ids(|v| v.visit_trait_item(trait_item));
925 ast_visit::walk_trait_item(cx, trait_item);
929 fn visit_impl_item(&mut self, impl_item: &ast::ImplItem) {
930 self.with_lint_attrs(&impl_item.attrs, |cx| {
931 run_lints!(cx, check_impl_item, early_passes, impl_item);
932 cx.visit_ids(|v| v.visit_impl_item(impl_item));
933 ast_visit::walk_impl_item(cx, impl_item);
937 fn visit_lifetime(&mut self, lt: &ast::Lifetime) {
938 run_lints!(self, check_lifetime, early_passes, lt);
941 fn visit_lifetime_def(&mut self, lt: &ast::LifetimeDef) {
942 run_lints!(self, check_lifetime_def, early_passes, lt);
945 fn visit_explicit_self(&mut self, es: &ast::ExplicitSelf) {
946 run_lints!(self, check_explicit_self, early_passes, es);
947 ast_visit::walk_explicit_self(self, es);
950 fn visit_path(&mut self, p: &ast::Path, id: ast::NodeId) {
951 run_lints!(self, check_path, early_passes, p, id);
952 ast_visit::walk_path(self, p);
955 fn visit_path_list_item(&mut self, prefix: &ast::Path, item: &ast::PathListItem) {
956 run_lints!(self, check_path_list_item, early_passes, item);
957 ast_visit::walk_path_list_item(self, prefix, item);
960 fn visit_attribute(&mut self, attr: &ast::Attribute) {
961 run_lints!(self, check_attribute, early_passes, attr);
965 // Output any lints that were previously added to the session.
966 impl<'a, 'tcx> IdVisitingOperation for LateContext<'a, 'tcx> {
967 fn visit_id(&mut self, id: ast::NodeId) {
968 match self.sess().lints.borrow_mut().remove(&id) {
971 debug!("LateContext::visit_id: id={:?} lints={:?}", id, lints);
972 for (lint_id, span, msg) in lints {
973 self.span_lint(lint_id.lint, span, &msg[..])
979 impl<'a> IdVisitingOperation for EarlyContext<'a> {
980 fn visit_id(&mut self, id: ast::NodeId) {
981 match self.sess.lints.borrow_mut().remove(&id) {
984 for (lint_id, span, msg) in lints {
985 self.span_lint(lint_id.lint, span, &msg[..])
992 // This lint pass is defined here because it touches parts of the `LateContext`
993 // that we don't want to expose. It records the lint level at certain AST
994 // nodes, so that the variant size difference check in trans can call
997 pub struct GatherNodeLevels;
999 impl LintPass for GatherNodeLevels {
1000 fn get_lints(&self) -> LintArray {
1005 impl LateLintPass for GatherNodeLevels {
1006 fn check_item(&mut self, cx: &LateContext, it: &hir::Item) {
1008 hir::ItemEnum(..) => {
1009 let lint_id = LintId::of(builtin::VARIANT_SIZE_DIFFERENCES);
1010 let lvlsrc = cx.lints.get_level_source(lint_id);
1012 (lvl, _) if lvl != Allow => {
1013 cx.node_levels.borrow_mut()
1014 .insert((it.id, lint_id), lvlsrc);
1024 /// Perform lint checking on a crate.
1026 /// Consumes the `lint_store` field of the `Session`.
1027 pub fn check_crate(tcx: &ty::ctxt, access_levels: &AccessLevels) {
1028 let krate = tcx.map.krate();
1029 let mut cx = LateContext::new(tcx, krate, access_levels);
1031 // Visit the whole crate.
1032 cx.with_lint_attrs(&krate.attrs, |cx| {
1033 cx.visit_id(ast::CRATE_NODE_ID);
1035 hir_visit::walk_crate(v, krate);
1038 // since the root module isn't visited as an item (because it isn't an
1039 // item), warn for it here.
1040 run_lints!(cx, check_crate, late_passes, krate);
1042 hir_visit::walk_crate(cx, krate);
1045 // If we missed any lints added to the session, then there's a bug somewhere
1046 // in the iteration code.
1047 for (id, v) in tcx.sess.lints.borrow().iter() {
1048 for &(lint, span, ref msg) in v {
1049 tcx.sess.span_bug(span,
1050 &format!("unprocessed lint {} at {}: {}",
1051 lint.as_str(), tcx.map.node_to_string(*id), *msg))
1055 *tcx.node_lint_levels.borrow_mut() = cx.node_levels.into_inner();
1058 pub fn check_ast_crate(sess: &Session, krate: &ast::Crate) {
1059 let mut cx = EarlyContext::new(sess, krate);
1061 // Visit the whole crate.
1062 cx.with_lint_attrs(&krate.attrs, |cx| {
1063 cx.visit_id(ast::CRATE_NODE_ID);
1065 v.visited_outermost = true;
1066 ast_visit::walk_crate(v, krate);
1069 // since the root module isn't visited as an item (because it isn't an
1070 // item), warn for it here.
1071 run_lints!(cx, check_crate, early_passes, krate);
1073 ast_visit::walk_crate(cx, krate);
1076 // Put the lint store back in the session.
1077 mem::replace(&mut *sess.lint_store.borrow_mut(), cx.lints);
1079 // If we missed any lints added to the session, then there's a bug somewhere
1080 // in the iteration code.
1081 for (_, v) in sess.lints.borrow().iter() {
1082 for &(lint, span, ref msg) in v {
1084 &format!("unprocessed lint {}: {}",
1085 lint.as_str(), *msg))