Rollup of 6 pull requests

Cargo.lock

@@ -4149,6 +4149,7 @@ dependencies = [
  "rustc_errors",
  "rustc_feature",
  "rustc_lexer",
+ "rustc_macros",
  "rustc_session",
  "rustc_span",
  "tracing",

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -2,7 +2,10 @@
 
 use rustc_errors::{Diagnostic, DiagnosticBuilder, ErrorGuaranteed};
 use rustc_infer::infer::{
-    error_reporting::nice_region_error::{self, find_param_with_region, NiceRegionError},
+    error_reporting::nice_region_error::{
+        self, find_anon_type, find_param_with_region, suggest_adding_lifetime_params,
+        NiceRegionError,
+    },
     error_reporting::unexpected_hidden_region_diagnostic,
     NllRegionVariableOrigin, RelateParamBound,
 };
@@ -630,6 +633,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         }
 
         self.add_static_impl_trait_suggestion(&mut diag, *fr, fr_name, *outlived_fr);
+        self.suggest_adding_lifetime_params(&mut diag, *fr, *outlived_fr);
 
         diag
     }
@@ -694,4 +698,33 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
             );
         }
     }
+
+    fn suggest_adding_lifetime_params(
+        &self,
+        diag: &mut Diagnostic,
+        sub: RegionVid,
+        sup: RegionVid,
+    ) {
+        let (Some(sub), Some(sup)) = (self.to_error_region(sub), self.to_error_region(sup)) else {
+            return
+        };
+
+        let Some((ty_sub, _)) = self
+            .infcx
+            .tcx
+            .is_suitable_region(sub)
+            .and_then(|anon_reg| find_anon_type(self.infcx.tcx, sub, &anon_reg.boundregion)) else {
+            return
+        };
+
+        let Some((ty_sup, _)) = self
+            .infcx
+            .tcx
+            .is_suitable_region(sup)
+            .and_then(|anon_reg| find_anon_type(self.infcx.tcx, sup, &anon_reg.boundregion)) else {
+            return
+        };
+
+        suggest_adding_lifetime_params(self.infcx.tcx, sub, ty_sup, ty_sub, diag);
+    }
 }

compiler/rustc_error_messages/locales/en-US/parser.ftl

@@ -1,3 +1,7 @@
 parser-struct-literal-body-without-path =
     struct literal body without path
     .suggestion = you might have forgotten to add the struct literal inside the block
+
+parser-maybe-report-ambiguous-plus =
+    ambiguous `+` in a type
+    .suggestion = use parentheses to disambiguate

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/different_lifetimes.rs

@@ -6,6 +6,7 @@ use crate::infer::error_reporting::nice_region_error::util::AnonymousParamInfo;
 use crate::infer::error_reporting::nice_region_error::NiceRegionError;
 use crate::infer::lexical_region_resolve::RegionResolutionError;
 use crate::infer::SubregionOrigin;
+use crate::infer::TyCtxt;
 
 use rustc_errors::{struct_span_err, Applicability, Diagnostic, ErrorGuaranteed};
 use rustc_hir as hir;
@@ -145,84 +146,83 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
             }
         }
 
-        self.suggest_adding_lifetime_params(sub, ty_sup, ty_sub, &mut err);
+        if suggest_adding_lifetime_params(self.tcx(), sub, ty_sup, ty_sub, &mut err) {
+            err.note("each elided lifetime in input position becomes a distinct lifetime");
+        }
 
         let reported = err.emit();
         Some(reported)
     }
+}
 
-    fn suggest_adding_lifetime_params(
-        &self,
-        sub: Region<'tcx>,
-        ty_sup: &Ty<'_>,
-        ty_sub: &Ty<'_>,
-        err: &mut Diagnostic,
-    ) {
-        if let (
-            hir::Ty { kind: hir::TyKind::Rptr(lifetime_sub, _), .. },
-            hir::Ty { kind: hir::TyKind::Rptr(lifetime_sup, _), .. },
-        ) = (ty_sub, ty_sup)
-        {
-            if lifetime_sub.name.is_elided() && lifetime_sup.name.is_elided() {
-                if let Some(anon_reg) = self.tcx().is_suitable_region(sub) {
-                    let hir_id = self.tcx().hir().local_def_id_to_hir_id(anon_reg.def_id);
-
-                    let node = self.tcx().hir().get(hir_id);
-                    let is_impl = matches!(&node, hir::Node::ImplItem(_));
-                    let generics = match node {
-                        hir::Node::Item(&hir::Item {
-                            kind: hir::ItemKind::Fn(_, ref generics, ..),
-                            ..
-                        })
-                        | hir::Node::TraitItem(&hir::TraitItem { ref generics, .. })
-                        | hir::Node::ImplItem(&hir::ImplItem { ref generics, .. }) => generics,
-                        _ => return,
-                    };
-
-                    let (suggestion_param_name, introduce_new) = generics
-                        .params
-                        .iter()
-                        .find(|p| matches!(p.kind, GenericParamKind::Lifetime { .. }))
-                        .and_then(|p| self.tcx().sess.source_map().span_to_snippet(p.span).ok())
-                        .map(|name| (name, false))
-                        .unwrap_or_else(|| ("'a".to_string(), true));
-
-                    let mut suggestions = vec![
-                        if let hir::LifetimeName::Underscore = lifetime_sub.name {
-                            (lifetime_sub.span, suggestion_param_name.clone())
-                        } else {
-                            (lifetime_sub.span.shrink_to_hi(), suggestion_param_name.clone() + " ")
-                        },
-                        if let hir::LifetimeName::Underscore = lifetime_sup.name {
-                            (lifetime_sup.span, suggestion_param_name.clone())
-                        } else {
-                            (lifetime_sup.span.shrink_to_hi(), suggestion_param_name.clone() + " ")
-                        },
-                    ];
-
-                    if introduce_new {
-                        let new_param_suggestion = match &generics.params {
-                            [] => (generics.span, format!("<{}>", suggestion_param_name)),
-                            [first, ..] => {
-                                (first.span.shrink_to_lo(), format!("{}, ", suggestion_param_name))
-                            }
-                        };
-
-                        suggestions.push(new_param_suggestion);
-                    }
-
-                    let mut sugg = String::from("consider introducing a named lifetime parameter");
-                    if is_impl {
-                        sugg.push_str(" and update trait if needed");
-                    }
-                    err.multipart_suggestion(
-                        sugg.as_str(),
-                        suggestions,
-                        Applicability::MaybeIncorrect,
-                    );
-                    err.note("each elided lifetime in input position becomes a distinct lifetime");
-                }
-            }
-        }
+pub fn suggest_adding_lifetime_params<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    sub: Region<'tcx>,
+    ty_sup: &Ty<'_>,
+    ty_sub: &Ty<'_>,
+    err: &mut Diagnostic,
+) -> bool {
+    let (
+        hir::Ty { kind: hir::TyKind::Rptr(lifetime_sub, _), .. },
+        hir::Ty { kind: hir::TyKind::Rptr(lifetime_sup, _), .. },
+    ) = (ty_sub, ty_sup) else {
+        return false;
+    };
+
+    if !lifetime_sub.name.is_elided() || !lifetime_sup.name.is_elided() {
+        return false;
+    };
+
+    let Some(anon_reg) = tcx.is_suitable_region(sub) else {
+        return false;
+    };
+
+    let hir_id = tcx.hir().local_def_id_to_hir_id(anon_reg.def_id);
+
+    let node = tcx.hir().get(hir_id);
+    let is_impl = matches!(&node, hir::Node::ImplItem(_));
+    let generics = match node {
+        hir::Node::Item(&hir::Item { kind: hir::ItemKind::Fn(_, ref generics, ..), .. })
+        | hir::Node::TraitItem(&hir::TraitItem { ref generics, .. })
+        | hir::Node::ImplItem(&hir::ImplItem { ref generics, .. }) => generics,
+        _ => return false,
+    };
+
+    let (suggestion_param_name, introduce_new) = generics
+        .params
+        .iter()
+        .find(|p| matches!(p.kind, GenericParamKind::Lifetime { .. }))
+        .and_then(|p| tcx.sess.source_map().span_to_snippet(p.span).ok())
+        .map(|name| (name, false))
+        .unwrap_or_else(|| ("'a".to_string(), true));
+
+    let mut suggestions = vec![
+        if let hir::LifetimeName::Underscore = lifetime_sub.name {
+            (lifetime_sub.span, suggestion_param_name.clone())
+        } else {
+            (lifetime_sub.span.shrink_to_hi(), suggestion_param_name.clone() + " ")
+        },
+        if let hir::LifetimeName::Underscore = lifetime_sup.name {
+            (lifetime_sup.span, suggestion_param_name.clone())
+        } else {
+            (lifetime_sup.span.shrink_to_hi(), suggestion_param_name.clone() + " ")
+        },
+    ];
+
+    if introduce_new {
+        let new_param_suggestion = match &generics.params {
+            [] => (generics.span, format!("<{}>", suggestion_param_name)),
+            [first, ..] => (first.span.shrink_to_lo(), format!("{}, ", suggestion_param_name)),
+        };
+
+        suggestions.push(new_param_suggestion);
     }
+
+    let mut sugg = String::from("consider introducing a named lifetime parameter");
+    if is_impl {
+        sugg.push_str(" and update trait if needed");
+    }
+    err.multipart_suggestion(sugg.as_str(), suggestions, Applicability::MaybeIncorrect);
+
+    true
 }

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/find_anon_type.rs

@@ -20,7 +20,7 @@ use rustc_middle::ty::{self, Region, TyCtxt};
 /// ```
 /// The function returns the nested type corresponding to the anonymous region
 /// for e.g., `&u8` and `Vec<&u8>`.
-pub(crate) fn find_anon_type<'tcx>(
+pub fn find_anon_type<'tcx>(
     tcx: TyCtxt<'tcx>,
     region: Region<'tcx>,
     br: &ty::BoundRegionKind,

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mod.rs

@@ -14,6 +14,8 @@ mod static_impl_trait;
 mod trait_impl_difference;
 mod util;
 
+pub use different_lifetimes::suggest_adding_lifetime_params;
+pub use find_anon_type::find_anon_type;
 pub use static_impl_trait::suggest_new_region_bound;
 pub use util::find_param_with_region;
 

compiler/rustc_macros/src/session_diagnostic.rs

@@ -308,7 +308,7 @@ impl<'a> SessionDiagnosticDerive<'a> {
             {
                 fn into_diagnostic(
                     self,
-                    #sess: &'__session_diagnostic_sess rustc_session::Session
+                    #sess: &'__session_diagnostic_sess rustc_session::parse::ParseSess
                 ) -> rustc_errors::DiagnosticBuilder<'__session_diagnostic_sess, #param_ty> {
                     use rustc_errors::IntoDiagnosticArg;
                     #implementation

compiler/rustc_parse/Cargo.toml

@@ -13,6 +13,7 @@ rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_feature = { path = "../rustc_feature" }
 rustc_lexer = { path = "../rustc_lexer" }
+rustc_macros = { path = "../rustc_macros" }
 rustc_errors = { path = "../rustc_errors" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -21,6 +21,7 @@ use rustc_errors::{pluralize, struct_span_err, Diagnostic, EmissionGuarantee, Er
 use rustc_errors::{
     Applicability, DiagnosticBuilder, DiagnosticMessage, Handler, MultiSpan, PResult,
 };
+use rustc_macros::SessionDiagnostic;
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::{kw, Ident};
 use rustc_span::{Span, SpanSnippetError, DUMMY_SP};
@@ -241,6 +242,16 @@ impl MultiSugg {
         err.multipart_suggestions(msg, suggestions.map(|s| s.patches), applicability);
     }
 }
+
+#[derive(SessionDiagnostic)]
+#[error(slug = "parser-maybe-report-ambiguous-plus")]
+struct AmbiguousPlus {
+    pub sum_ty: String,
+    #[primary_span]
+    #[suggestion(code = "({sum_ty})")]
+    pub span: Span,
+}
+
 // SnapshotParser is used to create a snapshot of the parser
 // without causing duplicate errors being emitted when the `Parser`
 // is dropped.
@@ -1196,15 +1207,7 @@ impl<'a> Parser<'a> {
         ty: &Ty,
     ) {
         if matches!(allow_plus, AllowPlus::No) && impl_dyn_multi {
-            let sum_with_parens = format!("({})", pprust::ty_to_string(&ty));
-            self.struct_span_err(ty.span, "ambiguous `+` in a type")
-                .span_suggestion(
-                    ty.span,
-                    "use parentheses to disambiguate",
-                    sum_with_parens,
-                    Applicability::MachineApplicable,
-                )
-                .emit();
+            self.sess.emit_err(AmbiguousPlus { sum_ty: pprust::ty_to_string(&ty), span: ty.span });
         }
     }
 

compiler/rustc_session/src/parse.rs

@@ -3,13 +3,14 @@
 
 use crate::config::CheckCfg;
 use crate::lint::{BufferedEarlyLint, BuiltinLintDiagnostics, Lint, LintId};
+use crate::SessionDiagnostic;
 use rustc_ast::node_id::NodeId;
 use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_data_structures::sync::{Lock, Lrc};
 use rustc_errors::{emitter::SilentEmitter, ColorConfig, Handler};
 use rustc_errors::{
     error_code, fallback_fluent_bundle, Applicability, Diagnostic, DiagnosticBuilder,
-    ErrorGuaranteed, MultiSpan,
+    DiagnosticMessage, ErrorGuaranteed, MultiSpan,
 };
 use rustc_feature::{find_feature_issue, GateIssue, UnstableFeatures};
 use rustc_span::edition::Edition;
@@ -287,4 +288,23 @@ impl ParseSess {
     pub fn proc_macro_quoted_spans(&self) -> Vec<Span> {
         self.proc_macro_quoted_spans.lock().clone()
     }
+
+    pub fn emit_err<'a>(&'a self, err: impl SessionDiagnostic<'a>) -> ErrorGuaranteed {
+        err.into_diagnostic(self).emit()
+    }
+
+    pub fn emit_warning<'a>(&'a self, warning: impl SessionDiagnostic<'a, ()>) {
+        warning.into_diagnostic(self).emit()
+    }
+
+    pub fn struct_err(
+        &self,
+        msg: impl Into<DiagnosticMessage>,
+    ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
+        self.span_diagnostic.struct_err(msg)
+    }
+
+    pub fn struct_warn(&self, msg: impl Into<DiagnosticMessage>) -> DiagnosticBuilder<'_, ()> {
+        self.span_diagnostic.struct_warn(msg)
+    }
 }

compiler/rustc_session/src/session.rs

@@ -212,7 +212,7 @@ pub struct PerfStats {
 pub trait SessionDiagnostic<'a, T: EmissionGuarantee = ErrorGuaranteed> {
     /// Write out as a diagnostic out of `sess`.
     #[must_use]
-    fn into_diagnostic(self, sess: &'a Session) -> DiagnosticBuilder<'a, T>;
+    fn into_diagnostic(self, sess: &'a ParseSess) -> DiagnosticBuilder<'a, T>;
 }
 
 impl Session {
@@ -334,7 +334,7 @@ impl Session {
         &self,
         msg: impl Into<DiagnosticMessage>,
     ) -> DiagnosticBuilder<'_, ErrorGuaranteed> {
-        self.diagnostic().struct_err(msg)
+        self.parse_sess.struct_err(msg)
     }
     pub fn struct_err_with_code(
         &self,
@@ -414,10 +414,10 @@ impl Session {
         self.diagnostic().err(msg)
     }
     pub fn emit_err<'a>(&'a self, err: impl SessionDiagnostic<'a>) -> ErrorGuaranteed {
-        err.into_diagnostic(self).emit()
+        self.parse_sess.emit_err(err)
     }
     pub fn emit_warning<'a>(&'a self, warning: impl SessionDiagnostic<'a, ()>) {
-        warning.into_diagnostic(self).emit()
+        self.parse_sess.emit_warning(warning)
     }
     #[inline]
     pub fn err_count(&self) -> usize {

library/core/src/fmt/mod.rs

@@ -19,6 +19,7 @@ mod nofloat;
 mod num;
 
 #[stable(feature = "fmt_flags_align", since = "1.28.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "Alignment")]
 /// Possible alignments returned by `Formatter::align`
 #[derive(Debug)]
 pub enum Alignment {
@@ -462,6 +463,7 @@ impl<'a> Arguments<'a> {
 ///
 /// [`format()`]: ../../std/fmt/fn.format.html
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "Arguments")]
 #[derive(Copy, Clone)]
 pub struct Arguments<'a> {
     // Format string pieces to print.