Auto merge of #133978 - matthiaskrgr:rollup-6gh1iho, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - #130209 (Stabilize `std::io::ErrorKind::CrossesDevices`)
 - #130254 (Stabilize `std::io::ErrorKind::QuotaExceeded`)
 - #132187 (Add Extend impls for tuples of arity 1 through 12)
 - #133875 (handle `--json-output` properly)
 - #133934 (Do not implement unsafe auto traits for types with unsafe fields)
 - #133954 (Hide errors whose suggestions would contain error constants or types)
 - #133960 (rustdoc: remove eq for clean::Attributes)

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

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -998,6 +998,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                                         self.lower_const_arg(ct, FeedConstTy::No).into()
                                     }
                                 };
+                                if term.references_error() {
+                                    continue;
+                                }
                                 // FIXME(#97583): This isn't syntactically well-formed!
                                 where_bounds.push(format!(
                                     "        T: {trait}::{assoc_name} = {term}",

compiler/rustc_middle/src/ty/context.rs

@@ -585,6 +585,10 @@ impl<'tcx> Interner for TyCtxt<'tcx> {
         self.trait_def(trait_def_id).implement_via_object
     }
 
+    fn trait_is_unsafe(self, trait_def_id: Self::DefId) -> bool {
+        self.trait_def(trait_def_id).safety == hir::Safety::Unsafe
+    }
+
     fn is_impl_trait_in_trait(self, def_id: DefId) -> bool {
         self.is_impl_trait_in_trait(def_id)
     }

compiler/rustc_middle/src/ty/sty.rs

@@ -978,6 +978,14 @@ impl<'tcx> rustc_type_ir::inherent::Ty<TyCtxt<'tcx>> for Ty<'tcx> {
     fn async_destructor_ty(self, interner: TyCtxt<'tcx>) -> Ty<'tcx> {
         self.async_destructor_ty(interner)
     }
+
+    fn has_unsafe_fields(self) -> bool {
+        if let ty::Adt(adt_def, ..) = self.kind() {
+            adt_def.all_fields().any(|x| x.safety == hir::Safety::Unsafe)
+        } else {
+            false
+        }
+    }
 }
 
 /// Type utilities

compiler/rustc_mir_build/src/thir/constant.rs

@@ -2,7 +2,7 @@ use rustc_ast as ast;
 use rustc_hir::LangItem;
 use rustc_middle::bug;
 use rustc_middle::mir::interpret::{LitToConstError, LitToConstInput};
-use rustc_middle::ty::{self, ScalarInt, TyCtxt};
+use rustc_middle::ty::{self, ScalarInt, TyCtxt, TypeVisitableExt as _};
 use tracing::trace;
 
 use crate::build::parse_float_into_scalar;
@@ -13,6 +13,10 @@ pub(crate) fn lit_to_const<'tcx>(
 ) -> Result<ty::Const<'tcx>, LitToConstError> {
     let LitToConstInput { lit, ty, neg } = lit_input;
 
+    if let Err(guar) = ty.error_reported() {
+        return Ok(ty::Const::new_error(tcx, guar));
+    }
+
     let trunc = |n| {
         let width = match tcx.layout_of(ty::TypingEnv::fully_monomorphized().as_query_input(ty)) {
             Ok(layout) => layout.size,

compiler/rustc_next_trait_solver/src/solve/trait_goals.rs

@@ -169,6 +169,14 @@ where
             return result;
         }
 
+        // Only consider auto impls of unsafe traits when there are no unsafe
+        // fields.
+        if ecx.cx().trait_is_unsafe(goal.predicate.def_id())
+            && goal.predicate.self_ty().has_unsafe_fields()
+        {
+            return Err(NoSolution);
+        }
+
         // We only look into opaque types during analysis for opaque types
         // outside of their defining scope. Doing so for opaques in the
         // defining scope may require calling `typeck` on the same item we're

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -18,6 +18,7 @@ use rustc_infer::traits::{
 use rustc_middle::ty::fast_reject::DeepRejectCtxt;
 use rustc_middle::ty::{self, ToPolyTraitRef, Ty, TypeVisitableExt, TypingMode};
 use rustc_middle::{bug, span_bug};
+use rustc_type_ir::Interner;
 use tracing::{debug, instrument, trace};
 
 use super::SelectionCandidate::*;
@@ -794,6 +795,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 | ty::Never
                 | ty::Tuple(_)
                 | ty::CoroutineWitness(..) => {
+                    use rustc_type_ir::inherent::*;
+
+                    // Only consider auto impls of unsafe traits when there are
+                    // no unsafe fields.
+                    if self.tcx().trait_is_unsafe(def_id) && self_ty.has_unsafe_fields() {
+                        return;
+                    }
+
                     // Only consider auto impls if there are no manual impls for the root of `self_ty`.
                     //
                     // For example, we only consider auto candidates for `&i32: Auto` if no explicit impl

compiler/rustc_type_ir/src/inherent.rs

@@ -136,6 +136,9 @@ pub trait Ty<I: Interner<Ty = Self>>:
         matches!(self.kind(), ty::FnPtr(..))
     }
 
+    /// Checks whether this type is an ADT that has unsafe fields.
+    fn has_unsafe_fields(self) -> bool;
+
     fn fn_sig(self, interner: I) -> ty::Binder<I, ty::FnSig<I>> {
         match self.kind() {
             ty::FnPtr(sig_tys, hdr) => sig_tys.with(hdr),

compiler/rustc_type_ir/src/interner.rs

@@ -270,6 +270,9 @@ pub trait Interner:
 
     fn trait_may_be_implemented_via_object(self, trait_def_id: Self::DefId) -> bool;
 
+    /// Returns `true` if this is an `unsafe trait`.
+    fn trait_is_unsafe(self, trait_def_id: Self::DefId) -> bool;
+
     fn is_impl_trait_in_trait(self, def_id: Self::DefId) -> bool;
 
     fn delay_bug(self, msg: impl ToString) -> Self::ErrorGuaranteed;