rustc_lint/
expect.rs

1use rustc_data_structures::fx::FxHashSet;
2use rustc_middle::lint::LintExpectation;
3use rustc_middle::query::Providers;
4use rustc_middle::ty::TyCtxt;
5use rustc_session::lint::LintExpectationId;
6use rustc_session::lint::builtin::UNFULFILLED_LINT_EXPECTATIONS;
7use rustc_span::Symbol;
8
9use crate::lints::{Expectation, ExpectationNote};
10
11pub(crate) fn provide(providers: &mut Providers) {
12    *providers = Providers { lint_expectations, check_expectations, ..*providers };
13}
14
15fn lint_expectations(tcx: TyCtxt<'_>, (): ()) -> Vec<(LintExpectationId, LintExpectation)> {
16    let krate = tcx.hir_crate_items(());
17
18    let mut expectations = Vec::new();
19
20    for owner in krate.owners() {
21        // Deduplicate expectations
22        let mut inner_expectations = Vec::new();
23        let lints = tcx.shallow_lint_levels_on(owner);
24        for expectation in &lints.expectations {
25            let canonicalized = canonicalize_id(&expectation.0);
26            if !inner_expectations.iter().any(|(id, _)| canonicalize_id(id) == canonicalized) {
27                inner_expectations.push(expectation.clone());
28            }
29        }
30        expectations.extend(inner_expectations);
31    }
32
33    expectations
34}
35
36fn canonicalize_id(expect_id: &LintExpectationId) -> (rustc_span::AttrId, u16) {
37    match *expect_id {
38        LintExpectationId::Unstable { attr_id, lint_index, .. } => (attr_id, lint_index),
39        LintExpectationId::Stable { attr_id, lint_index, .. } => (attr_id, lint_index),
40    }
41}
42
43fn check_expectations(tcx: TyCtxt<'_>, tool_filter: Option<Symbol>) {
44    let lint_expectations = tcx.lint_expectations(());
45    let fulfilled_expectations = tcx.dcx().steal_fulfilled_expectation_ids();
46
47    // Turn a `LintExpectationId` into a `(AttrId, lint_index)` pair.
48    let fulfilled_expectations: FxHashSet<_> =
49        fulfilled_expectations.iter().map(canonicalize_id).collect();
50
51    for (expect_id, expectation) in lint_expectations {
52        // This check will always be true, since `lint_expectations` only holds stable ids
53        let LintExpectationId::Stable { hir_id, .. } = expect_id else {
54            {
    ::core::panicking::panic_fmt(format_args!("internal error: entered unreachable code: {0}",
            format_args!("at this stage all `LintExpectationId`s are stable")));
};unreachable!("at this stage all `LintExpectationId`s are stable");
55        };
56
57        let expect_id = canonicalize_id(expect_id);
58
59        if !fulfilled_expectations.contains(&expect_id)
60            && tool_filter.is_none_or(|filter| expectation.lint_tool == Some(filter))
61        {
62            let rationale = expectation.reason.map(|rationale| ExpectationNote { rationale });
63            let note = expectation.is_unfulfilled_lint_expectations;
64            tcx.emit_node_span_lint(
65                UNFULFILLED_LINT_EXPECTATIONS,
66                *hir_id,
67                expectation.emission_span,
68                Expectation { rationale, note },
69            );
70        }
71    }
72}
rustc_lint/expect.rs

rustc_lint/
expect.rs
