1 // Copyright 2012-2014 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::ExportedItems;
29 use middle::ty::{self, Ty};
30 use session::{early_error, Session};
31 use lint::{Level, LevelSource, Lint, LintId, LintArray, LintPass, LintPassObject};
32 use lint::{Default, CommandLine, Node, Allow, Warn, Deny, Forbid};
34 use util::nodemap::FnvHashMap;
36 use std::cell::RefCell;
38 use syntax::ast_util::IdVisitingOperation;
39 use syntax::attr::AttrMetaMethods;
41 use syntax::codemap::Span;
42 use syntax::visit::{Visitor, FnKind};
43 use syntax::parse::token::InternedString;
44 use syntax::{ast, ast_util, visit};
46 /// Information about the registered lints.
48 /// This is basically the subset of `Context` that we can
49 /// build early in the compile pipeline.
50 pub struct LintStore {
51 /// Registered lints. The bool is true if the lint was
52 /// added by a plugin.
53 lints: Vec<(&'static Lint, bool)>,
55 /// Trait objects for each lint pass.
56 /// This is only `None` while iterating over the objects. See the definition
58 passes: Option<Vec<LintPassObject>>,
60 /// Lints indexed by name.
61 by_name: FnvHashMap<String, TargetLint>,
63 /// Current levels of each lint, and where they were set.
64 levels: FnvHashMap<LintId, LevelSource>,
66 /// Map of registered lint groups to what lints they expand to. The bool
67 /// is true if the lint group was added by a plugin.
68 lint_groups: FnvHashMap<&'static str, (Vec<LintId>, bool)>,
71 /// The targed of the `by_name` map, which accounts for renaming/deprecation.
73 /// A direct lint target
76 /// Temporary renaming, used for easing migration pain; see #16545
77 Renamed(String, LintId),
81 fn get_level_source(&self, lint: LintId) -> LevelSource {
82 match self.levels.get(&lint) {
84 None => (Allow, Default),
88 fn set_level(&mut self, lint: LintId, lvlsrc: LevelSource) {
89 if lvlsrc.0 == Allow {
90 self.levels.remove(&lint);
92 self.levels.insert(lint, lvlsrc);
96 pub fn new() -> LintStore {
100 by_name: FnvHashMap::new(),
101 levels: FnvHashMap::new(),
102 lint_groups: FnvHashMap::new(),
106 pub fn get_lints<'t>(&'t self) -> &'t [(&'static Lint, bool)] {
107 self.lints.index(&FullRange)
110 pub fn get_lint_groups<'t>(&'t self) -> Vec<(&'static str, Vec<LintId>, bool)> {
111 self.lint_groups.iter().map(|(k, v)| (*k,
116 pub fn register_pass(&mut self, sess: Option<&Session>,
117 from_plugin: bool, pass: LintPassObject) {
118 for &lint in pass.get_lints().iter() {
119 self.lints.push((*lint, from_plugin));
121 let id = LintId::of(*lint);
122 if self.by_name.insert(lint.name_lower(), Id(id)).is_some() {
123 let msg = format!("duplicate specification of lint {}", lint.name_lower());
124 match (sess, from_plugin) {
125 // We load builtin lints first, so a duplicate is a compiler bug.
126 // Use early_error when handling -W help with no crate.
127 (None, _) => early_error(msg.index(&FullRange)),
128 (Some(sess), false) => sess.bug(msg.index(&FullRange)),
130 // A duplicate name from a plugin is a user error.
131 (Some(sess), true) => sess.err(msg.index(&FullRange)),
135 if lint.default_level != Allow {
136 self.levels.insert(id, (lint.default_level, Default));
139 self.passes.as_mut().unwrap().push(pass);
142 pub fn register_group(&mut self, sess: Option<&Session>,
143 from_plugin: bool, name: &'static str,
145 let new = self.lint_groups.insert(name, (to, from_plugin)).is_none();
148 let msg = format!("duplicate specification of lint group {}", name);
149 match (sess, from_plugin) {
150 // We load builtin lints first, so a duplicate is a compiler bug.
151 // Use early_error when handling -W help with no crate.
152 (None, _) => early_error(msg.index(&FullRange)),
153 (Some(sess), false) => sess.bug(msg.index(&FullRange)),
155 // A duplicate name from a plugin is a user error.
156 (Some(sess), true) => sess.err(msg.index(&FullRange)),
161 fn register_renamed(&mut self, old_name: &str, new_name: &str) {
162 let target = match self.by_name.get(new_name) {
163 Some(&Id(lint_id)) => lint_id.clone(),
164 _ => panic!("invalid lint renaming of {} to {}", old_name, new_name)
166 self.by_name.insert(old_name.to_string(), Renamed(new_name.to_string(), target));
169 pub fn register_builtin(&mut self, sess: Option<&Session>) {
170 macro_rules! add_builtin {
171 ($sess:ident, $($name:ident),*,) => (
173 self.register_pass($sess, false, box builtin::$name as LintPassObject);
178 macro_rules! add_builtin_with_new {
179 ($sess:ident, $($name:ident),*,) => (
181 self.register_pass($sess, false, box builtin::$name::new() as LintPassObject);
186 macro_rules! add_lint_group {
187 ($sess:ident, $name:expr, $($lint:ident),*) => (
188 self.register_group($sess, false, $name, vec![$(LintId::of(builtin::$lint)),*]);
206 NonShorthandFieldPatterns,
212 MissingCopyImplementations,
215 add_builtin_with_new!(sess,
221 add_lint_group!(sess, "bad_style",
222 NON_CAMEL_CASE_TYPES, NON_SNAKE_CASE, NON_UPPER_CASE_GLOBALS);
224 add_lint_group!(sess, "unused",
225 UNUSED_IMPORTS, UNUSED_VARIABLES, UNUSED_ASSIGNMENTS, DEAD_CODE,
226 UNUSED_MUT, UNREACHABLE_CODE, UNUSED_MUST_USE,
227 UNUSED_UNSAFE, PATH_STATEMENTS);
229 // We have one lint pass defined in this module.
230 self.register_pass(sess, false, box GatherNodeLevels as LintPassObject);
232 // Insert temporary renamings for a one-time deprecation (#16545)
233 self.register_renamed("unnecessary_typecast", "unused_typecasts");
234 self.register_renamed("unsigned_negate", "unsigned_negation");
235 self.register_renamed("type_limits", "unused_comparisons");
236 self.register_renamed("type_overflow", "overflowing_literals");
237 self.register_renamed("ctypes", "improper_ctypes");
238 self.register_renamed("owned_heap_memory", "box_pointers");
239 self.register_renamed("unused_attribute", "unused_attributes");
240 self.register_renamed("path_statement", "path_statements");
241 self.register_renamed("unused_result", "unused_results");
242 self.register_renamed("non_uppercase_statics", "non_upper_case_globals");
243 self.register_renamed("unnecessary_parens", "unused_parens");
244 self.register_renamed("unnecessary_import_braces", "unused_import_braces");
245 self.register_renamed("unsafe_block", "unsafe_blocks");
246 self.register_renamed("unnecessary_allocation", "unused_allocation");
247 self.register_renamed("missing_doc", "missing_docs");
248 self.register_renamed("unused_extern_crate", "unused_extern_crates");
249 self.register_renamed("unnecessary_qualification", "unused_qualifications");
250 self.register_renamed("unrecognized_lint", "unknown_lints");
251 self.register_renamed("unused_variable", "unused_variables");
252 self.register_renamed("dead_assignment", "unused_assignments");
253 self.register_renamed("unknown_crate_type", "unknown_crate_types");
254 self.register_renamed("variant_size_difference", "variant_size_differences");
255 self.register_renamed("transmute_fat_ptr", "fat_ptr_transmutes");
256 self.register_renamed("raw_pointer_deriving", "raw_pointer_derive");
260 #[allow(unused_variables)]
261 fn find_lint(&self, lint_name: &str, sess: &Session, span: Option<Span>)
264 match self.by_name.get(lint_name) {
265 Some(&Id(lint_id)) => Some(lint_id),
266 Some(&Renamed(ref new_name, lint_id)) => {
267 let warning = format!("lint {} has been renamed to {}",
268 lint_name, new_name);
270 Some(span) => sess.span_warn(span, warning.index(&FullRange)),
271 None => sess.warn(warning.index(&FullRange)),
279 pub fn process_command_line(&mut self, sess: &Session) {
280 for &(ref lint_name, level) in sess.opts.lint_opts.iter() {
281 match self.find_lint(lint_name.index(&FullRange), sess, None) {
282 Some(lint_id) => self.set_level(lint_id, (level, CommandLine)),
284 match self.lint_groups.iter().map(|(&x, pair)| (x, pair.0.clone()))
285 .collect::<FnvHashMap<&'static str,
287 .get(lint_name.index(&FullRange)) {
290 .map(|lint_id: &LintId|
291 self.set_level(*lint_id, (level, CommandLine)))
292 .collect::<Vec<()>>();
294 None => sess.err(format!("unknown {} flag: {}",
295 level.as_str(), lint_name).index(&FullRange)),
303 /// Context for lint checking.
304 pub struct Context<'a, 'tcx: 'a> {
305 /// Type context we're checking in.
306 pub tcx: &'a ty::ctxt<'tcx>,
308 /// The crate being checked.
309 pub krate: &'a ast::Crate,
311 /// Items exported from the crate being checked.
312 pub exported_items: &'a ExportedItems,
314 /// The store of registered lints.
317 /// When recursing into an attributed node of the ast which modifies lint
318 /// levels, this stack keeps track of the previous lint levels of whatever
320 level_stack: Vec<(LintId, LevelSource)>,
322 /// Level of lints for certain NodeIds, stored here because the body of
323 /// the lint needs to run in trans.
324 node_levels: RefCell<FnvHashMap<(ast::NodeId, LintId), LevelSource>>,
327 /// Convenience macro for calling a `LintPass` method on every pass in the context.
328 macro_rules! run_lints { ($cx:expr, $f:ident, $($args:expr),*) => ({
329 // Move the vector of passes out of `$cx` so that we can
330 // iterate over it mutably while passing `$cx` to the methods.
331 let mut passes = $cx.lints.passes.take().unwrap();
332 for obj in passes.iter_mut() {
333 obj.$f($cx, $($args),*);
335 $cx.lints.passes = Some(passes);
338 /// Parse the lint attributes into a vector, with `Err`s for malformed lint
339 /// attributes. Writing this as an iterator is an enormous mess.
340 pub fn gather_attrs(attrs: &[ast::Attribute])
341 -> Vec<Result<(InternedString, Level, Span), Span>> {
342 let mut out = vec!();
343 for attr in attrs.iter() {
344 let level = match Level::from_str(attr.name().get()) {
349 attr::mark_used(attr);
351 let meta = &attr.node.value;
352 let metas = match meta.node {
353 ast::MetaList(_, ref metas) => metas,
355 out.push(Err(meta.span));
360 for meta in metas.iter() {
361 out.push(match meta.node {
362 ast::MetaWord(ref lint_name) => Ok((lint_name.clone(), level, meta.span)),
370 /// Emit a lint as a warning or an error (or not at all)
371 /// according to `level`.
373 /// This lives outside of `Context` so it can be used by checks
374 /// in trans that run after the main lint pass is finished. Most
375 /// lints elsewhere in the compiler should call
376 /// `Session::add_lint()` instead.
377 pub fn raw_emit_lint(sess: &Session, lint: &'static Lint,
378 lvlsrc: LevelSource, span: Option<Span>, msg: &str) {
379 let (mut level, source) = lvlsrc;
380 if level == Allow { return }
382 let name = lint.name_lower();
384 let msg = match source {
386 format!("{}, #[{}({})] on by default", msg,
387 level.as_str(), name)
390 format!("{} [-{} {}]", msg,
392 Warn => 'W', Deny => 'D', Forbid => 'F',
394 }, name.replace("_", "-"))
402 // For purposes of printing, we can treat forbid as deny.
403 if level == Forbid { level = Deny; }
405 match (level, span) {
406 (Warn, Some(sp)) => sess.span_warn(sp, msg.index(&FullRange)),
407 (Warn, None) => sess.warn(msg.index(&FullRange)),
408 (Deny, Some(sp)) => sess.span_err(sp, msg.index(&FullRange)),
409 (Deny, None) => sess.err(msg.index(&FullRange)),
410 _ => sess.bug("impossible level in raw_emit_lint"),
413 for span in note.into_iter() {
414 sess.span_note(span, "lint level defined here");
418 impl<'a, 'tcx> Context<'a, 'tcx> {
419 fn new(tcx: &'a ty::ctxt<'tcx>,
420 krate: &'a ast::Crate,
421 exported_items: &'a ExportedItems) -> Context<'a, 'tcx> {
422 // We want to own the lint store, so move it out of the session.
423 let lint_store = mem::replace(&mut *tcx.sess.lint_store.borrow_mut(),
429 exported_items: exported_items,
432 node_levels: RefCell::new(FnvHashMap::new()),
436 /// Get the overall compiler `Session` object.
437 pub fn sess(&'a self) -> &'a Session {
441 /// Get the level of `lint` at the current position of the lint
443 pub fn current_level(&self, lint: &'static Lint) -> Level {
444 self.lints.levels.get(&LintId::of(lint)).map_or(Allow, |&(lvl, _)| lvl)
447 fn lookup_and_emit(&self, lint: &'static Lint, span: Option<Span>, msg: &str) {
448 let (level, src) = match self.lints.levels.get(&LintId::of(lint)) {
450 Some(&(Warn, src)) => {
451 let lint_id = LintId::of(builtin::WARNINGS);
452 (self.lints.get_level_source(lint_id).0, src)
457 raw_emit_lint(&self.tcx.sess, lint, (level, src), span, msg);
460 /// Emit a lint at the appropriate level, with no associated span.
461 pub fn lint(&self, lint: &'static Lint, msg: &str) {
462 self.lookup_and_emit(lint, None, msg);
465 /// Emit a lint at the appropriate level, for a particular span.
466 pub fn span_lint(&self, lint: &'static Lint, span: Span, msg: &str) {
467 self.lookup_and_emit(lint, Some(span), msg);
470 /// Merge the lints specified by any lint attributes into the
471 /// current lint context, call the provided function, then reset the
472 /// lints in effect to their previous state.
473 fn with_lint_attrs<F>(&mut self,
474 attrs: &[ast::Attribute],
476 F: FnOnce(&mut Context),
478 // Parse all of the lint attributes, and then add them all to the
479 // current dictionary of lint information. Along the way, keep a history
480 // of what we changed so we can roll everything back after invoking the
484 for result in gather_attrs(attrs).into_iter() {
485 let v = match result {
487 self.tcx.sess.span_err(span, "malformed lint attribute");
490 Ok((lint_name, level, span)) => {
491 match self.lints.find_lint(lint_name.get(), &self.tcx.sess, Some(span)) {
492 Some(lint_id) => vec![(lint_id, level, span)],
494 match self.lints.lint_groups.get(lint_name.get()) {
495 Some(&(ref v, _)) => v.iter()
496 .map(|lint_id: &LintId|
497 (*lint_id, level, span))
500 self.span_lint(builtin::UNKNOWN_LINTS, span,
501 format!("unknown `{}` attribute: `{}`",
502 level.as_str(), lint_name).as_slice());
511 for (lint_id, level, span) in v.into_iter() {
512 let now = self.lints.get_level_source(lint_id).0;
513 if now == Forbid && level != Forbid {
514 let lint_name = lint_id.as_str();
515 self.tcx.sess.span_err(span,
516 format!("{}({}) overruled by outer forbid({})",
517 level.as_str(), lint_name,
518 lint_name).index(&FullRange));
519 } else if now != level {
520 let src = self.lints.get_level_source(lint_id).1;
521 self.level_stack.push((lint_id, (now, src)));
523 self.lints.set_level(lint_id, (level, Node(span)));
528 run_lints!(self, enter_lint_attrs, attrs);
530 run_lints!(self, exit_lint_attrs, attrs);
533 for _ in range(0, pushed) {
534 let (lint, lvlsrc) = self.level_stack.pop().unwrap();
535 self.lints.set_level(lint, lvlsrc);
539 fn visit_ids<F>(&mut self, f: F) where
540 F: FnOnce(&mut ast_util::IdVisitor<Context>)
542 let mut v = ast_util::IdVisitor {
544 pass_through_items: false,
545 visited_outermost: false,
551 impl<'a, 'tcx, 'v> Visitor<'v> for Context<'a, 'tcx> {
552 fn visit_item(&mut self, it: &ast::Item) {
553 self.with_lint_attrs(it.attrs.index(&FullRange), |cx| {
554 run_lints!(cx, check_item, it);
555 cx.visit_ids(|v| v.visit_item(it));
556 visit::walk_item(cx, it);
560 fn visit_foreign_item(&mut self, it: &ast::ForeignItem) {
561 self.with_lint_attrs(it.attrs.index(&FullRange), |cx| {
562 run_lints!(cx, check_foreign_item, it);
563 visit::walk_foreign_item(cx, it);
567 fn visit_view_item(&mut self, i: &ast::ViewItem) {
568 self.with_lint_attrs(i.attrs.index(&FullRange), |cx| {
569 run_lints!(cx, check_view_item, i);
570 cx.visit_ids(|v| v.visit_view_item(i));
571 visit::walk_view_item(cx, i);
575 fn visit_pat(&mut self, p: &ast::Pat) {
576 run_lints!(self, check_pat, p);
577 visit::walk_pat(self, p);
580 fn visit_expr(&mut self, e: &ast::Expr) {
581 run_lints!(self, check_expr, e);
582 visit::walk_expr(self, e);
585 fn visit_stmt(&mut self, s: &ast::Stmt) {
586 run_lints!(self, check_stmt, s);
587 visit::walk_stmt(self, s);
590 fn visit_fn(&mut self, fk: FnKind<'v>, decl: &'v ast::FnDecl,
591 body: &'v ast::Block, span: Span, id: ast::NodeId) {
593 visit::FkMethod(_, _, m) => {
594 self.with_lint_attrs(m.attrs.index(&FullRange), |cx| {
595 run_lints!(cx, check_fn, fk, decl, body, span, id);
597 v.visit_fn(fk, decl, body, span, id);
599 visit::walk_fn(cx, fk, decl, body, span);
603 run_lints!(self, check_fn, fk, decl, body, span, id);
604 visit::walk_fn(self, fk, decl, body, span);
609 fn visit_ty_method(&mut self, t: &ast::TypeMethod) {
610 self.with_lint_attrs(t.attrs.index(&FullRange), |cx| {
611 run_lints!(cx, check_ty_method, t);
612 visit::walk_ty_method(cx, t);
616 fn visit_struct_def(&mut self,
621 run_lints!(self, check_struct_def, s, ident, g, id);
622 visit::walk_struct_def(self, s);
623 run_lints!(self, check_struct_def_post, s, ident, g, id);
626 fn visit_struct_field(&mut self, s: &ast::StructField) {
627 self.with_lint_attrs(s.node.attrs.index(&FullRange), |cx| {
628 run_lints!(cx, check_struct_field, s);
629 visit::walk_struct_field(cx, s);
633 fn visit_variant(&mut self, v: &ast::Variant, g: &ast::Generics) {
634 self.with_lint_attrs(v.node.attrs.index(&FullRange), |cx| {
635 run_lints!(cx, check_variant, v, g);
636 visit::walk_variant(cx, v, g);
637 run_lints!(cx, check_variant_post, v, g);
641 // FIXME(#10894) should continue recursing
642 fn visit_ty(&mut self, t: &ast::Ty) {
643 run_lints!(self, check_ty, t);
646 fn visit_ident(&mut self, sp: Span, id: ast::Ident) {
647 run_lints!(self, check_ident, sp, id);
650 fn visit_mod(&mut self, m: &ast::Mod, s: Span, n: ast::NodeId) {
651 run_lints!(self, check_mod, m, s, n);
652 visit::walk_mod(self, m);
655 fn visit_local(&mut self, l: &ast::Local) {
656 run_lints!(self, check_local, l);
657 visit::walk_local(self, l);
660 fn visit_block(&mut self, b: &ast::Block) {
661 run_lints!(self, check_block, b);
662 visit::walk_block(self, b);
665 fn visit_arm(&mut self, a: &ast::Arm) {
666 run_lints!(self, check_arm, a);
667 visit::walk_arm(self, a);
670 fn visit_decl(&mut self, d: &ast::Decl) {
671 run_lints!(self, check_decl, d);
672 visit::walk_decl(self, d);
675 fn visit_expr_post(&mut self, e: &ast::Expr) {
676 run_lints!(self, check_expr_post, e);
679 fn visit_generics(&mut self, g: &ast::Generics) {
680 run_lints!(self, check_generics, g);
681 visit::walk_generics(self, g);
684 fn visit_trait_item(&mut self, m: &ast::TraitItem) {
685 run_lints!(self, check_trait_method, m);
686 visit::walk_trait_item(self, m);
689 fn visit_opt_lifetime_ref(&mut self, sp: Span, lt: &Option<ast::Lifetime>) {
690 run_lints!(self, check_opt_lifetime_ref, sp, lt);
693 fn visit_lifetime_ref(&mut self, lt: &ast::Lifetime) {
694 run_lints!(self, check_lifetime_ref, lt);
697 fn visit_lifetime_def(&mut self, lt: &ast::LifetimeDef) {
698 run_lints!(self, check_lifetime_def, lt);
701 fn visit_explicit_self(&mut self, es: &ast::ExplicitSelf) {
702 run_lints!(self, check_explicit_self, es);
703 visit::walk_explicit_self(self, es);
706 fn visit_mac(&mut self, mac: &ast::Mac) {
707 run_lints!(self, check_mac, mac);
708 visit::walk_mac(self, mac);
711 fn visit_path(&mut self, p: &ast::Path, id: ast::NodeId) {
712 run_lints!(self, check_path, p, id);
713 visit::walk_path(self, p);
716 fn visit_attribute(&mut self, attr: &ast::Attribute) {
717 run_lints!(self, check_attribute, attr);
721 // Output any lints that were previously added to the session.
722 impl<'a, 'tcx> IdVisitingOperation for Context<'a, 'tcx> {
723 fn visit_id(&mut self, id: ast::NodeId) {
724 match self.tcx.sess.lints.borrow_mut().remove(&id) {
727 for (lint_id, span, msg) in lints.into_iter() {
728 self.span_lint(lint_id.lint, span, msg.index(&FullRange))
735 // This lint pass is defined here because it touches parts of the `Context`
736 // that we don't want to expose. It records the lint level at certain AST
737 // nodes, so that the variant size difference check in trans can call
740 struct GatherNodeLevels;
742 impl LintPass for GatherNodeLevels {
743 fn get_lints(&self) -> LintArray {
747 fn check_item(&mut self, cx: &Context, it: &ast::Item) {
749 ast::ItemEnum(..) => {
750 let lint_id = LintId::of(builtin::VARIANT_SIZE_DIFFERENCES);
751 let lvlsrc = cx.lints.get_level_source(lint_id);
753 (lvl, _) if lvl != Allow => {
754 cx.node_levels.borrow_mut()
755 .insert((it.id, lint_id), lvlsrc);
765 /// Perform lint checking on a crate.
767 /// Consumes the `lint_store` field of the `Session`.
768 pub fn check_crate(tcx: &ty::ctxt,
769 exported_items: &ExportedItems) {
770 let krate = tcx.map.krate();
771 let mut cx = Context::new(tcx, krate, exported_items);
773 // Visit the whole crate.
774 cx.with_lint_attrs(krate.attrs.index(&FullRange), |cx| {
775 cx.visit_id(ast::CRATE_NODE_ID);
777 v.visited_outermost = true;
778 visit::walk_crate(v, krate);
781 // since the root module isn't visited as an item (because it isn't an
782 // item), warn for it here.
783 run_lints!(cx, check_crate, krate);
785 visit::walk_crate(cx, krate);
788 // If we missed any lints added to the session, then there's a bug somewhere
789 // in the iteration code.
790 for (id, v) in tcx.sess.lints.borrow().iter() {
791 for &(lint, span, ref msg) in v.iter() {
792 tcx.sess.span_bug(span,
793 format!("unprocessed lint {} at {}: {}",
794 lint.as_str(), tcx.map.node_to_string(*id), *msg).as_slice())
798 tcx.sess.abort_if_errors();
799 *tcx.node_lint_levels.borrow_mut() = cx.node_levels.into_inner();