Auto merge of rust-lang#109130 - matthiaskrgr:rollup-dm3jza6, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#108722 (Support for Fuchsia RISC-V target)
 - rust-lang#108880 (Remove tests/ui/impl-trait/in-trait/new-lowering-strategy in favor of using revisions on existing tests)
 - rust-lang#108909 (Fix object safety checks for new RPITITs)
 - rust-lang#108915 (Remove some direct calls to local_def_id_to_hir_id on diagnostics)
 - rust-lang#108923 (Make fns from other crates with RPITIT work for -Zlower-impl-trait-in-trait-to-assoc-ty)
 - rust-lang#109101 (Fall back to old metadata computation when type references errors)
 - rust-lang#109105 (Don't ICE for late-bound consts across `AnonConstBoundary`)
 - rust-lang#109110 (Don't codegen impossible to satisfy impls)
 - rust-lang#109116 (Emit diagnostic when calling methods on the unit type in method chains)

Failed merges:

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

Author: bors

compiler/rustc_hir/src/definitions.rs

@@ -404,8 +404,12 @@ impl DefPathData {
         match *self {
             TypeNs(name) | ValueNs(name) | MacroNs(name) | LifetimeNs(name) => Some(name),
 
+            // We use this name when collecting `ModChild`s.
+            // FIXME this could probably be removed with some refactoring to the name resolver.
+            ImplTraitAssocTy => Some(kw::Empty),
+
             Impl | ForeignMod | CrateRoot | Use | GlobalAsm | ClosureExpr | Ctor | AnonConst
-            | ImplTrait | ImplTraitAssocTy => None,
+            | ImplTrait => None,
         }
     }
 

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -1440,6 +1440,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                             tcx.associated_items(pred.def_id())
                                 .in_definition_order()
                                 .filter(|item| item.kind == ty::AssocKind::Type)
+                                .filter(|item| tcx.opt_rpitit_info(item.def_id).is_none())
                                 .map(|item| item.def_id),
                         );
                     }

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1427,25 +1427,25 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
             if let ResolvedArg::LateBound(..) = def && crossed_anon_const {
                 let use_span = self.tcx.hir().span(hir_id);
                 let def_span = self.tcx.def_span(param_def_id);
-                match self.tcx.def_kind(param_def_id) {
+                let guar = match self.tcx.def_kind(param_def_id) {
                     DefKind::ConstParam => {
                         self.tcx.sess.emit_err(errors::CannotCaptureLateBoundInAnonConst::Const {
                             use_span,
                             def_span,
-                        });
+                        })
                     }
                     DefKind::TyParam => {
                         self.tcx.sess.emit_err(errors::CannotCaptureLateBoundInAnonConst::Type {
                             use_span,
                             def_span,
-                        });
+                        })
                     }
                     _ => unreachable!(),
-                }
-                return;
+                };
+                self.map.defs.insert(hir_id, ResolvedArg::Error(guar));
+            } else {
+                self.map.defs.insert(hir_id, def);
             }
-
-            self.map.defs.insert(hir_id, def);
             return;
         }
 

compiler/rustc_hir_typeck/src/demand.rs

@@ -83,7 +83,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         self.annotate_expected_due_to_let_ty(err, expr, error);
         self.emit_type_mismatch_suggestions(err, expr, expr_ty, expected, expected_ty_expr, error);
         self.note_type_is_not_clone(err, expected, expr_ty, expr);
-        self.note_internal_mutation_in_method(err, expr, expected, expr_ty);
+        self.note_internal_mutation_in_method(err, expr, Some(expected), expr_ty);
         self.check_for_range_as_method_call(err, expr, expr_ty, expected);
         self.check_for_binding_assigned_block_without_tail_expression(err, expr, expr_ty, expected);
         self.check_wrong_return_type_due_to_generic_arg(err, expr, expr_ty);

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -950,44 +950,75 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         err: &mut Diagnostic,
         expr: &hir::Expr<'_>,
-        expected: Ty<'tcx>,
+        expected: Option<Ty<'tcx>>,
         found: Ty<'tcx>,
     ) {
         if found != self.tcx.types.unit {
             return;
         }
-        if let ExprKind::MethodCall(path_segment, rcvr, ..) = expr.kind {
-            if self
-                .typeck_results
+
+        let ExprKind::MethodCall(path_segment, rcvr, ..) = expr.kind else {
+            return;
+        };
+
+        let rcvr_has_the_expected_type = self
+            .typeck_results
+            .borrow()
+            .expr_ty_adjusted_opt(rcvr)
+            .and_then(|ty| expected.map(|expected_ty| expected_ty.peel_refs() == ty.peel_refs()))
+            .unwrap_or(false);
+
+        let prev_call_mutates_and_returns_unit = || {
+            self.typeck_results
                 .borrow()
-                .expr_ty_adjusted_opt(rcvr)
-                .map_or(true, |ty| expected.peel_refs() != ty.peel_refs())
-            {
-                return;
-            }
-            let mut sp = MultiSpan::from_span(path_segment.ident.span);
-            sp.push_span_label(
-                path_segment.ident.span,
-                format!(
-                    "this call modifies {} in-place",
-                    match rcvr.kind {
-                        ExprKind::Path(QPath::Resolved(
-                            None,
-                            hir::Path { segments: [segment], .. },
-                        )) => format!("`{}`", segment.ident),
-                        _ => "its receiver".to_string(),
-                    }
-                ),
-            );
+                .type_dependent_def_id(expr.hir_id)
+                .map(|def_id| self.tcx.fn_sig(def_id).skip_binder().skip_binder())
+                .and_then(|sig| sig.inputs_and_output.split_last())
+                .map(|(output, inputs)| {
+                    output.is_unit()
+                        && inputs
+                            .get(0)
+                            .and_then(|self_ty| self_ty.ref_mutability())
+                            .map_or(false, rustc_ast::Mutability::is_mut)
+                })
+                .unwrap_or(false)
+        };
+
+        if !(rcvr_has_the_expected_type || prev_call_mutates_and_returns_unit()) {
+            return;
+        }
+
+        let mut sp = MultiSpan::from_span(path_segment.ident.span);
+        sp.push_span_label(
+            path_segment.ident.span,
+            format!(
+                "this call modifies {} in-place",
+                match rcvr.kind {
+                    ExprKind::Path(QPath::Resolved(
+                        None,
+                        hir::Path { segments: [segment], .. },
+                    )) => format!("`{}`", segment.ident),
+                    _ => "its receiver".to_string(),
+                }
+            ),
+        );
+
+        let modifies_rcvr_note =
+            format!("method `{}` modifies its receiver in-place", path_segment.ident);
+        if rcvr_has_the_expected_type {
             sp.push_span_label(
                 rcvr.span,
                 "you probably want to use this value after calling the method...",
             );
+            err.span_note(sp, &modifies_rcvr_note);
+            err.note(&format!("...instead of the `()` output of method `{}`", path_segment.ident));
+        } else if let ExprKind::MethodCall(..) = rcvr.kind {
             err.span_note(
                 sp,
-                &format!("method `{}` modifies its receiver in-place", path_segment.ident),
+                modifies_rcvr_note.clone() + ", it is not meant to be used in method chains.",
             );
-            err.note(&format!("...instead of the `()` output of method `{}`", path_segment.ident));
+        } else {
+            err.span_note(sp, &modifies_rcvr_note);
         }
     }
 

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -416,6 +416,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 );
                 probe.is_ok()
             });
+
+            self.note_internal_mutation_in_method(
+                &mut err,
+                rcvr_expr,
+                expected.to_option(&self),
+                rcvr_ty,
+            );
         }
 
         let mut custom_span_label = false;

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1356,13 +1356,14 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         debug!("EncodeContext::encode_info_for_impl_item({:?})", def_id);
         let tcx = self.tcx;
 
-        let ast_item = self.tcx.hir().expect_impl_item(def_id.expect_local());
-        self.tables.impl_defaultness.set_some(def_id.index, ast_item.defaultness);
+        let defaultness = self.tcx.impl_defaultness(def_id.expect_local());
+        self.tables.impl_defaultness.set_some(def_id.index, defaultness);
         let impl_item = self.tcx.associated_item(def_id);
         self.tables.assoc_container.set_some(def_id.index, impl_item.container);
 
         match impl_item.kind {
             ty::AssocKind::Fn => {
+                let ast_item = self.tcx.hir().expect_impl_item(def_id.expect_local());
                 let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind else { bug!() };
                 self.tables.asyncness.set_some(def_id.index, sig.header.asyncness);
                 record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));

compiler/rustc_middle/src/hir/map/mod.rs

@@ -316,7 +316,7 @@ impl<'hir> Map<'hir> {
     /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
     #[inline]
     pub fn find_by_def_id(self, id: LocalDefId) -> Option<Node<'hir>> {
-        self.find(self.local_def_id_to_hir_id(id))
+        self.find(self.tcx.opt_local_def_id_to_hir_id(id)?)
     }
 
     /// Retrieves the `Node` corresponding to `id`, panicking if it cannot be found.
@@ -333,7 +333,7 @@ impl<'hir> Map<'hir> {
     }
 
     pub fn get_if_local(self, id: DefId) -> Option<Node<'hir>> {
-        id.as_local().and_then(|id| self.find(self.local_def_id_to_hir_id(id)))
+        id.as_local().and_then(|id| self.find(self.tcx.opt_local_def_id_to_hir_id(id)?))
     }
 
     pub fn get_generics(self, id: LocalDefId) -> Option<&'hir Generics<'hir>> {

compiler/rustc_middle/src/ty/layout.rs

@@ -730,7 +730,11 @@ where
                         */
                     };
 
-                    let metadata = if let Some(metadata_def_id) = tcx.lang_items().metadata_type() {
+                    let metadata = if let Some(metadata_def_id) = tcx.lang_items().metadata_type()
+                        // Projection eagerly bails out when the pointee references errors,
+                        // fall back to structurally deducing metadata.
+                        && !pointee.references_error()
+                    {
                         let metadata = tcx.normalize_erasing_regions(
                             cx.param_env(),
                             tcx.mk_projection(metadata_def_id, [pointee]),

compiler/rustc_monomorphize/src/collector.rs

@@ -1326,6 +1326,21 @@ fn create_mono_items_for_default_impls<'tcx>(
         return;
     }
 
+    // Unlike 'lazy' monomorphization that begins by collecting items transitively
+    // called by `main` or other global items, when eagerly monomorphizing impl
+    // items, we never actually check that the predicates of this impl are satisfied
+    // in a empty reveal-all param env (i.e. with no assumptions).
+    //
+    // Even though this impl has no substitutions, because we don't consider higher-
+    // ranked predicates such as `for<'a> &'a mut [u8]: Copy` to be trivially false,
+    // we must now check that the impl has no impossible-to-satisfy predicates.
+    if tcx.subst_and_check_impossible_predicates((
+        item.owner_id.to_def_id(),
+        &InternalSubsts::identity_for_item(tcx, item.owner_id.to_def_id()),
+    )) {
+        return;
+    }
+
     let Some(trait_ref) = tcx.impl_trait_ref(item.owner_id) else {
         return;
     };