Migration of LintDiagnostic - part 4

compiler/rustc_borrowck/src/lib.rs

@@ -27,7 +27,6 @@ use rustc_abi::FieldIdx;
 use rustc_data_structures::frozen::Frozen;
 use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_data_structures::graph::dominators::Dominators;
-use rustc_errors::LintDiagnostic;
 use rustc_hir as hir;
 use rustc_hir::CRATE_HIR_ID;
 use rustc_hir::def_id::LocalDefId;
@@ -715,7 +714,7 @@ impl<'tcx> Deref for BorrowckInferCtxt<'tcx> {
     }
 }
 
-struct MirBorrowckCtxt<'a, 'infcx, 'tcx> {
+pub(crate) struct MirBorrowckCtxt<'a, 'infcx, 'tcx> {
     root_cx: &'a mut BorrowCheckRootCtxt<'tcx>,
     infcx: &'infcx BorrowckInferCtxt<'tcx>,
     body: &'a Body<'tcx>,
@@ -1428,13 +1427,15 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
                     borrow,
                     Some((WriteKind::StorageDeadOrDrop, place)),
                 );
-                this.infcx.tcx.node_span_lint(
+                this.infcx.tcx.emit_node_span_lint(
                     TAIL_EXPR_DROP_ORDER,
                     CRATE_HIR_ID,
                     borrowed,
-                    |diag| {
-                        session_diagnostics::TailExprDropOrder { borrowed }.decorate_lint(diag);
-                        explain.add_explanation_to_diagnostic(&this, diag, "", None, None);
+                    session_diagnostics::TailExprDropOrder {
+                        borrowed,
+                        callback: |diag| {
+                            explain.add_explanation_to_diagnostic(&this, diag, "", None, None);
+                        },
                     },
                 );
                 // We may stop at the first case

compiler/rustc_borrowck/src/session_diagnostics.rs

@@ -1,6 +1,6 @@
-use rustc_errors::MultiSpan;
 use rustc_errors::codes::*;
-use rustc_macros::{Diagnostic, LintDiagnostic, Subdiagnostic};
+use rustc_errors::{Diag, DiagCtxtHandle, Diagnostic, Level, MultiSpan};
+use rustc_macros::{Diagnostic, Subdiagnostic};
 use rustc_middle::ty::{GenericArg, Ty};
 use rustc_span::Span;
 
@@ -595,9 +595,20 @@ pub(crate) struct SimdIntrinsicArgConst {
     pub intrinsic: String,
 }
 
-#[derive(LintDiagnostic)]
-#[diag("relative drop order changing in Rust 2024")]
-pub(crate) struct TailExprDropOrder {
-    #[label("this temporary value will be dropped at the end of the block")]
+pub(crate) struct TailExprDropOrder<F: FnOnce(&mut Diag<'_, ()>)> {
     pub borrowed: Span,
+    pub callback: F,
+}
+
+impl<'a, F: FnOnce(&mut Diag<'_, ()>)> Diagnostic<'a, ()> for TailExprDropOrder<F> {
+    fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, ()> {
+        let Self { borrowed, callback } = self;
+        let mut diag = Diag::new(dcx, level, "relative drop order changing in Rust 2024")
+            .with_span_label(
+                borrowed,
+                "this temporary value will be dropped at the end of the block",
+            );
+        callback(&mut diag);
+        diag
+    }
 }

compiler/rustc_lint/src/builtin.rs

@@ -22,7 +22,7 @@ use rustc_ast::visit::{FnCtxt, FnKind};
 use rustc_ast::{self as ast, *};
 use rustc_ast_pretty::pprust::expr_to_string;
 use rustc_attr_parsing::AttributeParser;
-use rustc_errors::{Applicability, LintDiagnostic, msg};
+use rustc_errors::{Applicability, Diagnostic, msg};
 use rustc_feature::GateIssue;
 use rustc_hir::attrs::{AttributeKind, DocAttribute};
 use rustc_hir::def::{DefKind, Res};
@@ -235,7 +235,7 @@ impl UnsafeCode {
         &self,
         cx: &EarlyContext<'_>,
         span: Span,
-        decorate: impl for<'a> LintDiagnostic<'a, ()>,
+        decorate: impl for<'a> Diagnostic<'a, ()>,
     ) {
         // This comes from a macro that has `#[allow_internal_unsafe]`.
         if span.allows_unsafe() {

compiler/rustc_lint/src/context.rs

@@ -11,7 +11,7 @@ use rustc_ast::util::parser::ExprPrecedence;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::sync;
 use rustc_data_structures::unord::UnordMap;
-use rustc_errors::{Diag, LintBuffer, LintDiagnostic, MultiSpan};
+use rustc_errors::{Diag, Diagnostic, LintBuffer, LintDiagnostic, MultiSpan};
 use rustc_feature::Features;
 use rustc_hir::def::Res;
 use rustc_hir::def_id::{CrateNum, DefId};
@@ -522,17 +522,28 @@ pub trait LintContext {
         decorate: impl for<'a, 'b> FnOnce(&'b mut Diag<'a, ()>),
     );
 
+    // FIXME: These methods should not take an Into<MultiSpan> -- instead, callers should need to
+    // set the span in their `decorate` function (preferably using set_span).
+    /// Emit a lint at the appropriate level, with an optional associated span.
+    ///
+    /// [`lint_level`]: rustc_middle::lint::lint_level#decorate-signature
+    #[track_caller]
+    fn opt_span_diag_lint<S: Into<MultiSpan>>(
+        &self,
+        lint: &'static Lint,
+        span: Option<S>,
+        decorate: impl for<'a> Diagnostic<'a, ()>,
+    );
+
     /// Emit a lint at `span` from a lint struct (some type that implements `LintDiagnostic`,
     /// typically generated by `#[derive(LintDiagnostic)]`).
     fn emit_span_lint<S: Into<MultiSpan>>(
         &self,
         lint: &'static Lint,
         span: S,
-        decorator: impl for<'a> LintDiagnostic<'a, ()>,
+        decorator: impl for<'a> Diagnostic<'a, ()>,
     ) {
-        self.opt_span_lint(lint, Some(span), |lint| {
-            decorator.decorate_lint(lint);
-        });
+        self.opt_span_diag_lint(lint, Some(span), decorator);
     }
 
     /// Emit a lint at `span` from a lazily-constructed lint struct (some type that implements
@@ -570,6 +581,12 @@ pub trait LintContext {
         });
     }
 
+    /// Emit a lint from a lint struct (some type that implements `LintDiagnostic`, typically
+    /// generated by `#[derive(LintDiagnostic)]`).
+    fn emit_diag_lint(&self, lint: &'static Lint, decorator: impl for<'a> Diagnostic<'a, ()>) {
+        self.opt_span_diag_lint(lint, None as Option<Span>, decorator);
+    }
+
     /// Emit a lint at the appropriate level, with no associated span.
     ///
     /// [`lint_level`]: rustc_middle::lint::lint_level#decorate-signature
@@ -644,6 +661,20 @@ impl<'tcx> LintContext for LateContext<'tcx> {
         }
     }
 
+    fn opt_span_diag_lint<S: Into<MultiSpan>>(
+        &self,
+        lint: &'static Lint,
+        span: Option<S>,
+        decorate: impl for<'a> Diagnostic<'a, ()>,
+    ) {
+        let hir_id = self.last_node_with_lint_attrs;
+
+        match span {
+            Some(s) => self.tcx.emit_node_span_lint(lint, hir_id, s, decorate),
+            None => self.tcx.emit_node_lint(lint, hir_id, decorate),
+        }
+    }
+
     fn get_lint_level(&self, lint: &'static Lint) -> LevelAndSource {
         self.tcx.lint_level_at_node(lint, self.last_node_with_lint_attrs)
     }
@@ -664,6 +695,15 @@ impl LintContext for EarlyContext<'_> {
         self.builder.opt_span_lint(lint, span.map(|s| s.into()), decorate)
     }
 
+    fn opt_span_diag_lint<S: Into<MultiSpan>>(
+        &self,
+        lint: &'static Lint,
+        span: Option<S>,
+        decorator: impl for<'a> Diagnostic<'a, ()>,
+    ) {
+        self.builder.opt_span_diag_lint(lint, span.map(|s| s.into()), decorator)
+    }
+
     fn get_lint_level(&self, lint: &'static Lint) -> LevelAndSource {
         self.builder.lint_level(lint)
     }

compiler/rustc_lint/src/dangling.rs

@@ -269,7 +269,6 @@ fn lint_expr(cx: &LateContext<'_>, expr: &Expr<'_>) {
         && let Some(fn_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id)
         && find_attr!(cx.tcx, fn_id, RustcAsPtr(_))
     {
-        // FIXME: use `emit_node_lint` when `#[primary_span]` is added.
         cx.tcx.emit_node_span_lint(
             DANGLING_POINTERS_FROM_TEMPORARIES,
             expr.hir_id,

compiler/rustc_lint/src/internal.rs

@@ -638,7 +638,7 @@ impl EarlyLintPass for BadUseOfFindAttr {
                     cx.emit_span_lint(
                         BAD_USE_OF_FIND_ATTR,
                         segment.span(),
-                        AttributeKindInFindAttr {},
+                        AttributeKindInFindAttr,
                     );
                 }
             }

compiler/rustc_lint/src/levels.rs

@@ -2,16 +2,16 @@ use rustc_ast::attr::AttributeExt;
 use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_data_structures::unord::UnordSet;
-use rustc_errors::{Diag, LintDiagnostic, MultiSpan, msg};
+use rustc_errors::{Diag, Diagnostic, MultiSpan, msg};
 use rustc_feature::{Features, GateIssue};
 use rustc_hir::HirId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_index::IndexVec;
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::lint::{
-    LevelAndSource, LintExpectation, LintLevelSource, ShallowLintLevelMap, lint_level,
-    reveal_actual_level,
+    LevelAndSource, LintExpectation, LintLevelSource, ShallowLintLevelMap, diag_lint_level,
+    lint_level, reveal_actual_level,
 };
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{RegisteredTools, TyCtxt};
@@ -822,8 +822,11 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                                 RenamedLintSuggestion::WithSpan { suggestion: sp, replace };
                             let name =
                                 tool_ident.map(|tool| format!("{tool}::{name}")).unwrap_or(name);
-                            let lint = RenamedLint { name: name.as_str(), replace, suggestion };
-                            self.emit_span_lint(RENAMED_AND_REMOVED_LINTS, sp.into(), lint);
+                            self.emit_span_lint(
+                                RENAMED_AND_REMOVED_LINTS,
+                                sp.into(),
+                                RenamedLint { name: name.as_str(), replace, suggestion },
+                            );
                         }
 
                         // If this lint was renamed, apply the new lint instead of ignoring the
@@ -844,8 +847,11 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                         if self.lint_added_lints {
                             let name =
                                 tool_ident.map(|tool| format!("{tool}::{name}")).unwrap_or(name);
-                            let lint = RemovedLint { name: name.as_str(), reason };
-                            self.emit_span_lint(RENAMED_AND_REMOVED_LINTS, sp.into(), lint);
+                            self.emit_span_lint(
+                                RENAMED_AND_REMOVED_LINTS,
+                                sp.into(),
+                                RemovedLint { name: name.as_str(), reason },
+                            );
                         }
                         continue;
                     }
@@ -861,8 +867,11 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
                                     from_rustc,
                                 }
                             });
-                            let lint = UnknownLint { name, suggestion };
-                            self.emit_span_lint(UNKNOWN_LINTS, sp.into(), lint);
+                            self.emit_span_lint(
+                                UNKNOWN_LINTS,
+                                sp.into(),
+                                UnknownLint { name, suggestion },
+                            );
                         }
                         continue;
                     }
@@ -967,8 +976,6 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
 
     /// Used to emit a lint-related diagnostic based on the current state of
     /// this lint context.
-    ///
-    /// [`lint_level`]: rustc_middle::lint::lint_level#decorate-signature
     #[track_caller]
     pub(crate) fn opt_span_lint(
         &self,
@@ -980,25 +987,34 @@ impl<'s, P: LintLevelsProvider> LintLevelsBuilder<'s, P> {
         lint_level(self.sess, lint, level, span, decorate)
     }
 
+    /// Used to emit a lint-related diagnostic based on the current state of
+    /// this lint context.
+    #[track_caller]
+    pub(crate) fn opt_span_diag_lint(
+        &self,
+        lint: &'static Lint,
+        span: Option<MultiSpan>,
+        decorator: impl for<'a> Diagnostic<'a, ()>,
+    ) {
+        let level = self.lint_level(lint);
+        diag_lint_level(self.sess, lint, level, span, decorator)
+    }
+
     #[track_caller]
     pub fn emit_span_lint(
         &self,
         lint: &'static Lint,
         span: MultiSpan,
-        decorate: impl for<'a> LintDiagnostic<'a, ()>,
+        decorator: impl for<'a> Diagnostic<'a, ()>,
     ) {
         let level = self.lint_level(lint);
-        lint_level(self.sess, lint, level, Some(span), |lint| {
-            decorate.decorate_lint(lint);
-        });
+        diag_lint_level(self.sess, lint, level, Some(span), decorator);
     }
 
     #[track_caller]
-    pub fn emit_lint(&self, lint: &'static Lint, decorate: impl for<'a> LintDiagnostic<'a, ()>) {
+    pub fn emit_lint(&self, lint: &'static Lint, decorator: impl for<'a> Diagnostic<'a, ()>) {
         let level = self.lint_level(lint);
-        lint_level(self.sess, lint, level, None, |lint| {
-            decorate.decorate_lint(lint);
-        });
+        diag_lint_level(self.sess, lint, level, None, decorator);
     }
 }