Set `LintExpectationId` in level and collect fulfilled ones (RFC-2383)

[rust.git] / compiler / rustc_errors / src / lib.rs

diff --git a/compiler/rustc_errors/src/lib.rs b/compiler/rustc_errors/src/lib.rs
index 463308c27b25a92e62d9fbe3b951fab1970f41e6..83e52e002ae2ab2791a289d59505be115a24c570 100644 (file)
--- a/compiler/rustc_errors/src/lib.rs
+++ b/compiler/rustc_errors/src/lib.rs
@@ -8,9 +8,9 @@
 #![feature(if_let_guard)]
 #![feature(let_else)]
 #![feature(nll)]
-#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 #![feature(adt_const_params)]
 #![allow(incomplete_features)]
+#![allow(rustc::potential_query_instability)]
 
 #[macro_use]
 extern crate rustc_macros;
@@ -20,6 +20,7 @@
 
 pub use emitter::ColorConfig;
 
+use rustc_lint_defs::LintExpectationId;
 use Level::*;
 
 use emitter::{is_case_difference, Emitter, EmitterWriter};
@@ -450,6 +451,15 @@ struct HandlerInner {
     deduplicated_warn_count: usize,
 
     future_breakage_diagnostics: Vec<Diagnostic>,
+
+    /// Lint [`Diagnostic`]s can be expected as described in [RFC-2383]. An
+    /// expected diagnostic will have the level `Expect` which additionally
+    /// carries the [`LintExpectationId`] of the expectation that can be
+    /// marked as fulfilled. This is a collection of all [`LintExpectationId`]s
+    /// that have been marked as fulfilled this way.
+    ///
+    /// [RFC-2383]: https://rust-lang.github.io/rfcs/2383-lint-reasons.html
+    fulfilled_expectations: FxHashSet<LintExpectationId>,
 }
 
 /// A key denoting where from a diagnostic was stashed.
@@ -570,6 +580,7 @@ pub fn with_emitter_and_flags(
                 emitted_diagnostics: Default::default(),
                 stashed_diagnostics: Default::default(),
                 future_breakage_diagnostics: Vec::new(),
+                fulfilled_expectations: Default::default(),
             }),
         }
     }
@@ -677,6 +688,11 @@ pub fn struct_allow(&self, msg: &str) -> DiagnosticBuilder<'_, ()> {
         DiagnosticBuilder::new(self, Level::Allow, msg)
     }
 
+    /// Construct a builder at the `Expect` level with the `msg`.
+    pub fn struct_expect(&self, msg: &str, id: LintExpectationId) -> DiagnosticBuilder<'_, ()> {
+        DiagnosticBuilder::new(self, Level::Expect(id), msg)
+    }
+
     /// Construct a builder at the `Error` level at the given `span` and with the `msg`.
     pub fn struct_span_err(
         &self,
@@ -906,6 +922,12 @@ pub fn emit_future_breakage_report(&self, diags: Vec<Diagnostic>) {
     pub fn emit_unused_externs(&self, lint_level: &str, unused_externs: &[&str]) {
         self.inner.borrow_mut().emit_unused_externs(lint_level, unused_externs)
     }
+
+    /// This methods steals all [`LintExpectationId`]s that are stored inside
+    /// [`HandlerInner`] and indicate that the linked expectation has been fulfilled.
+    pub fn steal_fulfilled_expectation_ids(&self) -> FxHashSet<LintExpectationId> {
+        std::mem::take(&mut self.inner.borrow_mut().fulfilled_expectations)
+    }
 }
 
 impl HandlerInner {
@@ -953,7 +975,10 @@ fn emit_diagnostic(&mut self, diagnostic: &Diagnostic) {
 
         (*TRACK_DIAGNOSTICS)(diagnostic);
 
-        if diagnostic.level == Allow {
+        if let Level::Expect(expectation_id) = diagnostic.level {
+            self.fulfilled_expectations.insert(expectation_id);
+            return;
+        } else if diagnostic.level == Allow {
             return;
         }
 
@@ -1250,6 +1275,7 @@ pub enum Level {
     Help,
     FailureNote,
     Allow,
+    Expect(LintExpectationId),
 }
 
 impl fmt::Display for Level {
@@ -1275,7 +1301,7 @@ fn color(self) -> ColorSpec {
                 spec.set_fg(Some(Color::Cyan)).set_intense(true);
             }
             FailureNote => {}
-            Allow => unreachable!(),
+            Allow | Expect(_) => unreachable!(),
         }
         spec
     }
@@ -1289,6 +1315,7 @@ pub fn to_str(self) -> &'static str {
             Help => "help",
             FailureNote => "failure-note",
             Allow => panic!("Shouldn't call on allowed error"),
+            Expect(_) => panic!("Shouldn't call on expected error"),
         }
     }