Auto merge of rust-lang#120829 - matthiaskrgr:rollup-p9tuwaa, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#120308 (core/time: avoid divisions in Duration::new)
 - rust-lang#120596 ([rustdoc] Correctly generate path for non-local items in source code pages)
 - rust-lang#120693 (Invert diagnostic lints.)
 - rust-lang#120704 (A drive-by rewrite of `give_region_a_name()`)
 - rust-lang#120809 (Use `transmute_unchecked` in `NonZero::new`.)
 - rust-lang#120817 (Fix more `ty::Error` ICEs in MIR passes)
 - rust-lang#120828 (Fix `ErrorGuaranteed` unsoundness with stash/steal.)

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_arena/src/lib.rs

@@ -22,8 +22,6 @@
 #![cfg_attr(test, feature(test))]
 #![feature(strict_provenance)]
 #![deny(unsafe_op_in_unsafe_fn)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 #![allow(internal_features)]
 #![allow(clippy::mut_from_ref)] // Arena allocators are one of the places where this pattern is fine.
 

compiler/rustc_ast/src/lib.rs

@@ -18,8 +18,6 @@
 #![feature(min_specialization)]
 #![feature(negative_impls)]
 #![feature(stmt_expr_attributes)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_ast_lowering/src/lib.rs

@@ -36,8 +36,6 @@
 #![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(let_chains)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate tracing;

compiler/rustc_ast_passes/src/lib.rs

@@ -11,8 +11,6 @@
 #![feature(if_let_guard)]
 #![feature(iter_is_partitioned)]
 #![feature(let_chains)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 
 pub mod ast_validation;
 mod errors;

compiler/rustc_ast_pretty/src/lib.rs

@@ -1,8 +1,6 @@
 #![allow(internal_features)]
 #![feature(rustdoc_internals)]
 #![doc(rust_logo)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 #![feature(box_patterns)]
 
 mod helpers;

compiler/rustc_attr/src/lib.rs

@@ -8,8 +8,6 @@
 #![feature(rustdoc_internals)]
 #![doc(rust_logo)]
 #![feature(let_chains)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_borrowck/src/borrow_set.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use crate::path_utils::allow_two_phase_borrow;
 use crate::place_ext::PlaceExt;
 use crate::BorrowIndex;

compiler/rustc_borrowck/src/borrowck_errors.rs

@@ -1,3 +1,6 @@
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use rustc_errors::{codes::*, struct_span_code_err, DiagCtxt, DiagnosticBuilder};
 use rustc_middle::ty::{self, Ty, TyCtxt};
 use rustc_span::Span;

compiler/rustc_borrowck/src/constraints/mod.rs

@@ -1,6 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-
 use rustc_data_structures::graph::scc::Sccs;
 use rustc_index::{IndexSlice, IndexVec};
 use rustc_middle::mir::ConstraintCategory;

compiler/rustc_borrowck/src/consumers.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 //! This file provides API for compiler consumers.
 
 use rustc_hir::def_id::LocalDefId;

compiler/rustc_borrowck/src/dataflow.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_data_structures::graph::WithSuccessors;
 use rustc_index::bit_set::BitSet;

compiler/rustc_borrowck/src/def_use.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use rustc_middle::mir::visit::{
     MutatingUseContext, NonMutatingUseContext, NonUseContext, PlaceContext,
 };

compiler/rustc_borrowck/src/diagnostics/bound_region_errors.rs

@@ -1,6 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-
 use rustc_errors::DiagnosticBuilder;
 use rustc_infer::infer::canonical::Canonical;
 use rustc_infer::infer::error_reporting::nice_region_error::NiceRegionError;

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -1,5 +1,8 @@
 // ignore-tidy-filelength
 
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use either::Either;
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxIndexSet;

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -1,5 +1,8 @@
 //! Print diagnostics to explain why values are borrowed.
 
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use rustc_errors::{Applicability, Diagnostic};
 use rustc_hir as hir;
 use rustc_hir::intravisit::Visitor;

compiler/rustc_borrowck/src/diagnostics/find_all_local_uses.rs

@@ -1,6 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-
 use std::collections::BTreeSet;
 
 use rustc_middle::mir::visit::{PlaceContext, Visitor};

compiler/rustc_borrowck/src/diagnostics/find_use.rs

@@ -1,6 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-
 use std::collections::VecDeque;
 use std::rc::Rc;
 

compiler/rustc_borrowck/src/diagnostics/move_errors.rs

@@ -1,3 +1,6 @@
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder};
 use rustc_middle::mir::*;
 use rustc_middle::ty::{self, Ty};

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -1,3 +1,6 @@
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use hir::ExprKind;
 use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder};
 use rustc_hir as hir;

compiler/rustc_borrowck/src/diagnostics/outlives_suggestion.rs

@@ -1,6 +1,9 @@
 //! Contains utilities for generating suggestions for borrowck errors related to unsatisfied
 //! outlives constraints.
 
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::Diagnostic;
 use rustc_middle::ty::RegionVid;

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 //! Error reporting machinery for lifetime errors.
 
 use rustc_data_structures::fx::FxIndexSet;

compiler/rustc_borrowck/src/diagnostics/region_name.rs

@@ -1,6 +1,10 @@
+#![allow(rustc::diagnostic_outside_of_impl)]
+#![allow(rustc::untranslatable_diagnostic)]
+
 use std::fmt::{self, Display};
 use std::iter;
 
+use rustc_data_structures::fx::IndexEntry;
 use rustc_errors::Diagnostic;
 use rustc_hir as hir;
 use rustc_hir::def::{DefKind, Res};
@@ -14,7 +18,7 @@ use crate::{universal_regions::DefiningTy, MirBorrowckCtxt};
 
 /// A name for a particular region used in emitting diagnostics. This name could be a generated
 /// name like `'1`, a name used by the user like `'a`, or a name like `'static`.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub(crate) struct RegionName {
     /// The name of the region (interned).
     pub(crate) name: Symbol,
@@ -25,7 +29,7 @@ pub(crate) struct RegionName {
 /// Denotes the source of a region that is named by a `RegionName`. For example, a free region that
 /// was named by the user would get `NamedLateParamRegion` and `'static` lifetime would get `Static`.
 /// This helps to print the right kinds of diagnostics.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub(crate) enum RegionNameSource {
     /// A bound (not free) region that was instantiated at the def site (not an HRTB).
     NamedEarlyParamRegion(Span),
@@ -42,7 +46,7 @@ pub(crate) enum RegionNameSource {
     /// The region corresponding to the return type of a closure.
     AnonRegionFromOutput(RegionNameHighlight, &'static str),
     /// The region from a type yielded by a coroutine.
-    AnonRegionFromYieldTy(Span, String),
+    AnonRegionFromYieldTy(Span, Symbol),
     /// An anonymous region from an async fn.
     AnonRegionFromAsyncFn(Span),
     /// An anonymous region from an impl self type or trait
@@ -51,19 +55,19 @@ pub(crate) enum RegionNameSource {
 
 /// Describes what to highlight to explain to the user that we're giving an anonymous region a
 /// synthesized name, and how to highlight it.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 pub(crate) enum RegionNameHighlight {
     /// The anonymous region corresponds to a reference that was found by traversing the type in the HIR.
     MatchedHirTy(Span),
     /// The anonymous region corresponds to a `'_` in the generics list of a struct/enum/union.
     MatchedAdtAndSegment(Span),
     /// The anonymous region corresponds to a region where the type annotation is completely missing
     /// from the code, e.g. in a closure arguments `|x| { ... }`, where `x` is a reference.
-    CannotMatchHirTy(Span, String),
+    CannotMatchHirTy(Span, Symbol),
     /// The anonymous region corresponds to a region where the type annotation is completely missing
     /// from the code, and *even if* we print out the full name of the type, the region name won't
     /// be included. This currently occurs for opaque types like `impl Future`.
-    Occluded(Span, String),
+    Occluded(Span, Symbol),
 }
 
 impl RegionName {
@@ -247,25 +251,28 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
 
         assert!(self.regioncx.universal_regions().is_universal_region(fr));
 
-        if let Some(value) = self.region_names.try_borrow_mut().unwrap().get(&fr) {
-            return Some(value.clone());
-        }
+        match self.region_names.borrow_mut().entry(fr) {
+            IndexEntry::Occupied(precomputed_name) => Some(*precomputed_name.get()),
+            IndexEntry::Vacant(slot) => {
+                let new_name = self
+                    .give_name_from_error_region(fr)
+                    .or_else(|| self.give_name_if_anonymous_region_appears_in_arguments(fr))
+                    .or_else(|| self.give_name_if_anonymous_region_appears_in_upvars(fr))
+                    .or_else(|| self.give_name_if_anonymous_region_appears_in_output(fr))
+                    .or_else(|| self.give_name_if_anonymous_region_appears_in_yield_ty(fr))
+                    .or_else(|| self.give_name_if_anonymous_region_appears_in_impl_signature(fr))
+                    .or_else(|| {
+                        self.give_name_if_anonymous_region_appears_in_arg_position_impl_trait(fr)
+                    });
+
+                if let Some(new_name) = new_name {
+                    slot.insert(new_name);
+                }
+                debug!("give_region_a_name: gave name {:?}", new_name);
 
-        let value = self
-            .give_name_from_error_region(fr)
-            .or_else(|| self.give_name_if_anonymous_region_appears_in_arguments(fr))
-            .or_else(|| self.give_name_if_anonymous_region_appears_in_upvars(fr))
-            .or_else(|| self.give_name_if_anonymous_region_appears_in_output(fr))
-            .or_else(|| self.give_name_if_anonymous_region_appears_in_yield_ty(fr))
-            .or_else(|| self.give_name_if_anonymous_region_appears_in_impl_signature(fr))
-            .or_else(|| self.give_name_if_anonymous_region_appears_in_arg_position_impl_trait(fr));
-
-        if let Some(value) = &value {
-            self.region_names.try_borrow_mut().unwrap().insert(fr, value.clone());
+                new_name
+            }
         }
-
-        debug!("give_region_a_name: gave name {:?}", value);
-        value
     }
 
     /// Checks for the case where `fr` maps to something that the
@@ -457,9 +464,9 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
         );
         if type_name.contains(&format!("'{counter}")) {
             // Only add a label if we can confirm that a region was labelled.
-            RegionNameHighlight::CannotMatchHirTy(span, type_name)
+            RegionNameHighlight::CannotMatchHirTy(span, Symbol::intern(&type_name))
         } else {
-            RegionNameHighlight::Occluded(span, type_name)
+            RegionNameHighlight::Occluded(span, Symbol::intern(&type_name))
         }
     }
 
@@ -888,7 +895,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
 
         Some(RegionName {
             name: self.synthesize_region_name(),
-            source: RegionNameSource::AnonRegionFromYieldTy(yield_span, type_name),
+            source: RegionNameSource::AnonRegionFromYieldTy(yield_span, Symbol::intern(&type_name)),
         })
     }
 
@@ -980,7 +987,7 @@ impl<'tcx> MirBorrowckCtxt<'_, 'tcx> {
             Some(RegionName {
                 name: region_name,
                 source: RegionNameSource::AnonRegionFromArgument(
-                    RegionNameHighlight::CannotMatchHirTy(arg_span, arg_name?.to_string()),
+                    RegionNameHighlight::CannotMatchHirTy(arg_span, arg_name?),
                 ),
             })
         } else {

compiler/rustc_borrowck/src/diagnostics/var_name.rs

@@ -1,6 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-
 use crate::region_infer::RegionInferenceContext;
 use rustc_index::IndexSlice;
 use rustc_middle::mir::{Body, Local};

compiler/rustc_borrowck/src/facts.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use crate::location::{LocationIndex, LocationTable};
 use crate::BorrowIndex;
 use polonius_engine::AllFacts as PoloniusFacts;

compiler/rustc_borrowck/src/location.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use rustc_index::IndexVec;
 use rustc_middle::mir::{BasicBlock, Body, Location};
 

compiler/rustc_borrowck/src/member_constraints.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use rustc_data_structures::captures::Captures;
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_index::{IndexSlice, IndexVec};

compiler/rustc_borrowck/src/nll.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 //! The entry point of the NLL borrow checker.
 
 use polonius_engine::{Algorithm, Output};

compiler/rustc_borrowck/src/path_utils.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use crate::borrow_set::{BorrowData, BorrowSet, TwoPhaseActivation};
 use crate::places_conflict;
 use crate::AccessDepth;

compiler/rustc_borrowck/src/place_ext.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use crate::borrow_set::LocalsStateAtExit;
 use rustc_hir as hir;
 use rustc_middle::mir::ProjectionElem;

compiler/rustc_borrowck/src/places_conflict.rs

@@ -50,8 +50,6 @@
 //!    and either equal or disjoint.
 //!  - If we did run out of access, the borrow can access a part of it.
 
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use crate::ArtificialField;
 use crate::Overlap;
 use crate::{AccessDepth, Deep, Shallow};

compiler/rustc_borrowck/src/polonius/loan_invalidations.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use rustc_data_structures::graph::dominators::Dominators;
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::{self, BasicBlock, Body, Location, NonDivergingIntrinsic, Place, Rvalue};

compiler/rustc_borrowck/src/polonius/loan_kills.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use rustc_middle::mir::visit::Visitor;
 use rustc_middle::mir::{
     Body, Local, Location, Place, PlaceRef, ProjectionElem, Rvalue, Statement, StatementKind,

compiler/rustc_borrowck/src/prefixes.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 //! From the NLL RFC: "The deep [aka 'supporting'] prefixes for an
 //! place are formed by stripping away fields and derefs, except that
 //! we stop when we reach the deref of a shared reference. [...] "

compiler/rustc_borrowck/src/region_infer/dump_mir.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 //! As part of generating the regions, if you enable `-Zdump-mir=nll`,
 //! we will generate an annotated copy of the MIR that includes the
 //! state of region inference. This code handles emitting the region

compiler/rustc_borrowck/src/region_infer/graphviz.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 //! This module provides linkage between RegionInferenceContext and
 //! `rustc_graphviz` traits, specialized to attaching borrowck analysis
 //! data to rendered labels.

compiler/rustc_borrowck/src/region_infer/opaque_types.rs

@@ -418,6 +418,8 @@ fn check_opaque_type_parameter_valid(
                 .into_iter()
                 .map(|i| tcx.def_span(opaque_generics.param_at(i, tcx).def_id))
                 .collect();
+            #[allow(rustc::diagnostic_outside_of_impl)]
+            #[allow(rustc::untranslatable_diagnostic)]
             return Err(tcx
                 .dcx()
                 .struct_span_err(span, "non-defining opaque type use in defining scope")

compiler/rustc_borrowck/src/region_infer/reverse_sccs.rs

@@ -1,5 +1,3 @@
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
 use crate::constraints::ConstraintSccIndex;
 use crate::RegionInferenceContext;
 use itertools::Itertools;