compiler/rustc_lint/src/expect.rs

   1 use crate::lints::{Expectation, ExpectationNote};
   2 use rustc_middle::ty::query::Providers;
   3 use rustc_middle::ty::TyCtxt;
   4 use rustc_session::lint::builtin::UNFULFILLED_LINT_EXPECTATIONS;
   5 use rustc_session::lint::LintExpectationId;
   6 use rustc_span::symbol::sym;
   7 use rustc_span::Symbol;
   8
   9 pub(crate) fn provide(providers: &mut Providers) {
  10     *providers = Providers { check_expectations, ..*providers };
  11 }
  12
  13 fn check_expectations(tcx: TyCtxt<'_>, tool_filter: Option<Symbol>) {
  14     if !tcx.features().enabled(sym::lint_reasons) {
  15         return;
  16     }
  17
  18     let lint_expectations = tcx.lint_expectations(());
  19     let fulfilled_expectations = tcx.sess.diagnostic().steal_fulfilled_expectation_ids();
  20
  21     tracing::debug!(?lint_expectations, ?fulfilled_expectations);
  22
  23     for (id, expectation) in lint_expectations {
  24         // This check will always be true, since `lint_expectations` only
  25         // holds stable ids
  26         if let LintExpectationId::Stable { hir_id, .. } = id {
  27             if !fulfilled_expectations.contains(&id)
  28                 && tool_filter.map_or(true, |filter| expectation.lint_tool == Some(filter))
  29             {
  30                 let rationale = expectation.reason.map(|rationale| ExpectationNote { rationale });
  31                 let note = expectation.is_unfulfilled_lint_expectations.then_some(());
  32                 tcx.emit_spanned_lint(
  33                     UNFULFILLED_LINT_EXPECTATIONS,
  34                     *hir_id,
  35                     expectation.emission_span,
  36                     Expectation { rationale, note },
  37                 );
  38             }
  39         } else {
  40             unreachable!("at this stage all `LintExpectationId`s are stable");
  41         }
  42     }
  43 }