1 use crate::context::{CheckLintNameResult, LintStore};
2 use crate::late::unerased_lint_store;
5 use rustc_ast::unwrap_or;
6 use rustc_ast_pretty::pprust;
7 use rustc_data_structures::fx::FxHashMap;
8 use rustc_errors::{struct_span_err, Applicability};
10 use rustc_hir::def_id::{CrateNum, LOCAL_CRATE};
11 use rustc_hir::{intravisit, HirId};
12 use rustc_middle::hir::map::Map;
13 use rustc_middle::lint::LintDiagnosticBuilder;
14 use rustc_middle::lint::{struct_lint_level, LintLevelMap, LintLevelSets, LintSet, LintSource};
15 use rustc_middle::ty::query::Providers;
16 use rustc_middle::ty::TyCtxt;
17 use rustc_session::lint::{builtin, Level, Lint, LintId};
18 use rustc_session::parse::feature_err;
19 use rustc_session::Session;
20 use rustc_span::symbol::{sym, Symbol};
21 use rustc_span::{source_map::MultiSpan, Span, DUMMY_SP};
25 fn lint_levels(tcx: TyCtxt<'_>, cnum: CrateNum) -> LintLevelMap {
26 assert_eq!(cnum, LOCAL_CRATE);
27 let store = unerased_lint_store(tcx);
28 let levels = LintLevelsBuilder::new(tcx.sess, false, &store);
29 let mut builder = LintLevelMapBuilder { levels, tcx, store };
30 let krate = tcx.hir().krate();
32 let push = builder.levels.push(&krate.item.attrs, &store, true);
33 builder.levels.register_id(hir::CRATE_HIR_ID);
34 for macro_def in krate.exported_macros {
35 builder.levels.register_id(macro_def.hir_id);
37 intravisit::walk_crate(&mut builder, krate);
38 builder.levels.pop(push);
40 builder.levels.build_map()
43 pub struct LintLevelsBuilder<'s> {
46 id_to_set: FxHashMap<HirId, u32>,
48 warn_about_weird_lints: bool,
51 pub struct BuilderPush {
56 impl<'s> LintLevelsBuilder<'s> {
57 pub fn new(sess: &'s Session, warn_about_weird_lints: bool, store: &LintStore) -> Self {
58 let mut builder = LintLevelsBuilder {
60 sets: LintLevelSets::new(),
62 id_to_set: Default::default(),
63 warn_about_weird_lints,
65 builder.process_command_line(sess, store);
66 assert_eq!(builder.sets.list.len(), 1);
70 fn process_command_line(&mut self, sess: &Session, store: &LintStore) {
71 let mut specs = FxHashMap::default();
72 self.sets.lint_cap = sess.opts.lint_cap.unwrap_or(Level::Forbid);
74 for &(ref lint_name, level) in &sess.opts.lint_opts {
75 store.check_lint_name_cmdline(sess, &lint_name, level);
77 // If the cap is less than this specified level, e.g., if we've got
78 // `--cap-lints allow` but we've also got `-D foo` then we ignore
79 // this specification as the lint cap will set it to allow anyway.
80 let level = cmp::min(level, self.sets.lint_cap);
82 let lint_flag_val = Symbol::intern(lint_name);
84 let ids = match store.find_lints(&lint_name) {
86 Err(_) => continue, // errors handled in check_lint_name_cmdline above
89 self.check_gated_lint(id, DUMMY_SP);
90 let src = LintSource::CommandLine(lint_flag_val);
91 specs.insert(id, (level, src));
95 self.sets.list.push(LintSet::CommandLine { specs });
98 /// Pushes a list of AST lint attributes onto this context.
100 /// This function will return a `BuilderPush` object which should be passed
101 /// to `pop` when this scope for the attributes provided is exited.
103 /// This function will perform a number of tasks:
105 /// * It'll validate all lint-related attributes in `attrs`
106 /// * It'll mark all lint-related attributes as used
107 /// * Lint levels will be updated based on the attributes provided
108 /// * Lint attributes are validated, e.g., a `#[forbid]` can't be switched to
111 /// Don't forget to call `pop`!
114 attrs: &[ast::Attribute],
118 let mut specs = FxHashMap::default();
119 let sess = self.sess;
120 let bad_attr = |span| struct_span_err!(sess, span, E0452, "malformed lint attribute input");
122 let level = match Level::from_symbol(attr.name_or_empty()) {
127 let meta = unwrap_or!(attr.meta(), continue);
128 attr::mark_used(attr);
130 let mut metas = unwrap_or!(meta.meta_item_list(), continue);
132 if metas.is_empty() {
133 // FIXME (#55112): issue unused-attributes lint for `#[level()]`
137 // Before processing the lint names, look for a reason (RFC 2383)
139 let mut reason = None;
140 let tail_li = &metas[metas.len() - 1];
141 if let Some(item) = tail_li.meta_item() {
143 ast::MetaItemKind::Word => {} // actual lint names handled later
144 ast::MetaItemKind::NameValue(ref name_value) => {
145 if item.path == sym::reason {
146 // found reason, reslice meta list to exclude it
147 metas = &metas[0..metas.len() - 1];
148 // FIXME (#55112): issue unused-attributes lint if we thereby
149 // don't have any lint names (`#[level(reason = "foo")]`)
150 if let ast::LitKind::Str(rationale, _) = name_value.kind {
151 if !self.sess.features_untracked().lint_reasons {
153 &self.sess.parse_sess,
156 "lint reasons are experimental",
160 reason = Some(rationale);
162 bad_attr(name_value.span)
163 .span_label(name_value.span, "reason must be a string literal")
168 .span_label(item.span, "bad attribute argument")
172 ast::MetaItemKind::List(_) => {
173 bad_attr(item.span).span_label(item.span, "bad attribute argument").emit();
179 let meta_item = match li.meta_item() {
180 Some(meta_item) if meta_item.is_word() => meta_item,
183 let mut err = bad_attr(sp);
184 let mut add_label = true;
185 if let Some(item) = li.meta_item() {
186 if let ast::MetaItemKind::NameValue(_) = item.kind {
187 if item.path == sym::reason {
188 err.span_label(sp, "reason in lint attribute must come last");
194 err.span_label(sp, "bad attribute argument");
200 let tool_name = if meta_item.path.segments.len() > 1 {
201 let tool_ident = meta_item.path.segments[0].ident;
202 if !attr::is_known_lint_tool(tool_ident) {
207 "an unknown tool name found in scoped lint: `{}`",
208 pprust::path_to_string(&meta_item.path),
214 Some(tool_ident.name)
218 let name = meta_item.path.segments.last().expect("empty lint name").ident.name;
219 match store.check_lint_name(&name.as_str(), tool_name) {
220 CheckLintNameResult::Ok(ids) => {
221 let src = LintSource::Node(name, li.span(), reason);
223 self.check_gated_lint(id, attr.span);
224 specs.insert(id, (level, src));
228 CheckLintNameResult::Tool(result) => {
231 let complete_name = &format!("{}::{}", tool_name.unwrap(), name);
232 let src = LintSource::Node(
233 Symbol::intern(complete_name),
238 specs.insert(*id, (level, src));
241 Err((Some(ids), new_lint_name)) => {
242 let lint = builtin::RENAMED_AND_REMOVED_LINTS;
244 self.sets.get_lint_level(lint, self.cur, Some(&specs), &sess);
250 Some(li.span().into()),
253 "lint name `{}` is deprecated \
254 and may not have an effect in the future. \
255 Also `cfg_attr(cargo-clippy)` won't be necessary anymore",
262 new_lint_name.to_string(),
263 Applicability::MachineApplicable,
269 let src = LintSource::Node(
270 Symbol::intern(&new_lint_name),
275 specs.insert(*id, (level, src));
279 // If Tool(Err(None, _)) is returned, then either the lint does not
280 // exist in the tool or the code was not compiled with the tool and
281 // therefore the lint was never added to the `LintStore`. To detect
282 // this is the responsibility of the lint tool.
287 _ if !self.warn_about_weird_lints => {}
289 CheckLintNameResult::Warning(msg, renamed) => {
290 let lint = builtin::RENAMED_AND_REMOVED_LINTS;
292 self.sets.get_lint_level(lint, self.cur, Some(&specs), &sess);
298 Some(li.span().into()),
300 let mut err = lint.build(&msg);
301 if let Some(new_name) = renamed {
306 Applicability::MachineApplicable,
313 CheckLintNameResult::NoLint(suggestion) => {
314 let lint = builtin::UNKNOWN_LINTS;
316 self.sets.get_lint_level(lint, self.cur, Some(&specs), self.sess);
322 Some(li.span().into()),
324 let mut db = lint.build(&format!("unknown lint: `{}`", name));
325 if let Some(suggestion) = suggestion {
329 suggestion.to_string(),
330 Applicability::MachineApplicable,
342 for (id, &(level, ref src)) in specs.iter() {
343 if !id.lint.crate_level_only {
347 let (lint_attr_name, lint_attr_span) = match *src {
348 LintSource::Node(name, span, _) => (name, span),
352 let lint = builtin::UNUSED_ATTRIBUTES;
353 let (lint_level, lint_src) =
354 self.sets.get_lint_level(lint, self.cur, Some(&specs), self.sess);
360 Some(lint_attr_span.into()),
362 let mut db = lint.build(&format!(
363 "{}({}) is ignored unless specified at crate level",
370 // don't set a separate error for every lint in the group
375 for (id, &(level, ref src)) in specs.iter() {
376 if level == Level::Forbid {
379 let forbid_src = match self.sets.get_lint_id_level(*id, self.cur, None) {
380 (Some(Level::Forbid), src) => src,
383 let forbidden_lint_name = match forbid_src {
384 LintSource::Default => id.to_string(),
385 LintSource::Node(name, _, _) => name.to_string(),
386 LintSource::CommandLine(name) => name.to_string(),
388 let (lint_attr_name, lint_attr_span) = match *src {
389 LintSource::Node(name, span, _) => (name, span),
392 let mut diag_builder = struct_span_err!(
396 "{}({}) overruled by outer forbid({})",
401 diag_builder.span_label(lint_attr_span, "overruled by previous forbid");
403 LintSource::Default => {}
404 LintSource::Node(_, forbid_source_span, reason) => {
405 diag_builder.span_label(forbid_source_span, "`forbid` level set here");
406 if let Some(rationale) = reason {
407 diag_builder.note(&rationale.as_str());
410 LintSource::CommandLine(_) => {
411 diag_builder.note("`forbid` lint level was set on command line");
415 // don't set a separate error for every lint in the group
420 if !specs.is_empty() {
421 self.cur = self.sets.list.len() as u32;
422 self.sets.list.push(LintSet::Node { specs, parent: prev });
425 BuilderPush { prev, changed: prev != self.cur }
428 /// Checks if the lint is gated on a feature that is not enabled.
429 fn check_gated_lint(&self, lint_id: LintId, span: Span) {
430 if let Some(feature) = lint_id.lint.feature_gate {
431 if !self.sess.features_untracked().enabled(feature) {
433 &self.sess.parse_sess,
436 &format!("the `{}` lint is unstable", lint_id.lint.name_lower()),
443 /// Called after `push` when the scope of a set of attributes are exited.
444 pub fn pop(&mut self, push: BuilderPush) {
445 self.cur = push.prev;
448 /// Find the lint level for a lint.
449 pub fn lint_level(&self, lint: &'static Lint) -> (Level, LintSource) {
450 self.sets.get_lint_level(lint, self.cur, None, self.sess)
453 /// Used to emit a lint-related diagnostic based on the current state of
454 /// this lint context.
458 span: Option<MultiSpan>,
459 decorate: impl for<'a> FnOnce(LintDiagnosticBuilder<'a>),
461 let (level, src) = self.lint_level(lint);
462 struct_lint_level(self.sess, lint, level, src, span, decorate)
465 /// Registers the ID provided with the current set of lints stored in
467 pub fn register_id(&mut self, id: HirId) {
468 self.id_to_set.insert(id, self.cur);
471 pub fn build(self) -> LintLevelSets {
475 pub fn build_map(self) -> LintLevelMap {
476 LintLevelMap { sets: self.sets, id_to_set: self.id_to_set }
480 struct LintLevelMapBuilder<'a, 'tcx> {
481 levels: LintLevelsBuilder<'tcx>,
483 store: &'a LintStore,
486 impl LintLevelMapBuilder<'_, '_> {
487 fn with_lint_attrs<F>(&mut self, id: hir::HirId, attrs: &[ast::Attribute], f: F)
489 F: FnOnce(&mut Self),
491 let is_crate_hir = id == hir::CRATE_HIR_ID;
492 let push = self.levels.push(attrs, self.store, is_crate_hir);
494 self.levels.register_id(id);
497 self.levels.pop(push);
501 impl<'tcx> intravisit::Visitor<'tcx> for LintLevelMapBuilder<'_, 'tcx> {
502 type Map = Map<'tcx>;
504 fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<Self::Map> {
505 intravisit::NestedVisitorMap::All(self.tcx.hir())
508 fn visit_param(&mut self, param: &'tcx hir::Param<'tcx>) {
509 self.with_lint_attrs(param.hir_id, ¶m.attrs, |builder| {
510 intravisit::walk_param(builder, param);
514 fn visit_item(&mut self, it: &'tcx hir::Item<'tcx>) {
515 self.with_lint_attrs(it.hir_id, &it.attrs, |builder| {
516 intravisit::walk_item(builder, it);
520 fn visit_foreign_item(&mut self, it: &'tcx hir::ForeignItem<'tcx>) {
521 self.with_lint_attrs(it.hir_id, &it.attrs, |builder| {
522 intravisit::walk_foreign_item(builder, it);
526 fn visit_expr(&mut self, e: &'tcx hir::Expr<'tcx>) {
527 self.with_lint_attrs(e.hir_id, &e.attrs, |builder| {
528 intravisit::walk_expr(builder, e);
532 fn visit_struct_field(&mut self, s: &'tcx hir::StructField<'tcx>) {
533 self.with_lint_attrs(s.hir_id, &s.attrs, |builder| {
534 intravisit::walk_struct_field(builder, s);
540 v: &'tcx hir::Variant<'tcx>,
541 g: &'tcx hir::Generics<'tcx>,
544 self.with_lint_attrs(v.id, &v.attrs, |builder| {
545 intravisit::walk_variant(builder, v, g, item_id);
549 fn visit_local(&mut self, l: &'tcx hir::Local<'tcx>) {
550 self.with_lint_attrs(l.hir_id, &l.attrs, |builder| {
551 intravisit::walk_local(builder, l);
555 fn visit_arm(&mut self, a: &'tcx hir::Arm<'tcx>) {
556 self.with_lint_attrs(a.hir_id, &a.attrs, |builder| {
557 intravisit::walk_arm(builder, a);
561 fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem<'tcx>) {
562 self.with_lint_attrs(trait_item.hir_id, &trait_item.attrs, |builder| {
563 intravisit::walk_trait_item(builder, trait_item);
567 fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem<'tcx>) {
568 self.with_lint_attrs(impl_item.hir_id, &impl_item.attrs, |builder| {
569 intravisit::walk_impl_item(builder, impl_item);
574 pub fn provide(providers: &mut Providers) {
575 providers.lint_levels = lint_levels;