Auto merge of #101115 - matthiaskrgr:rollup-iy14ztr, r=matthiaskrgr

Rollup of 13 pull requests

Successful merges:

 - #97015 (std::io: migrate ReadBuf to BorrowBuf/BorrowCursor)
 - #98301 (Add GDB/LLDB pretty-printers for NonZero types)
 - #99570 (Box::from(slice): Clarify that contents are copied)
 - #100296 (Add standard C error function aliases to last_os_error)
 - #100520 (Add mention of `BufReader` in `Read::bytes` docs)
 - #100885 (Export Cancel from std::os::fortanix_sgx::usercalls::raw)
 - #100955 (Some papercuts on error::Error)
 - #101002 (Provide structured suggestion for `hashmap[idx] = val`)
 - #101038 (no alignment check during interning)
 - #101055 (Use smaller span for suggestions)
 - #101091 (Extend attrs if local_def_id exists)
 - #101098 (rustc_middle: Remove `Visibility::Invisible`)
 - #101102 (unstable-book-gen: use std::fs::write)

Failed merges:

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

compiler/rustc_attr/src/session_diagnostics.rs

@@ -223,14 +223,12 @@ impl<'a> SessionDiagnostic<'a> for UnsupportedLiteral {
             error_code!(E0565),
         );
         if self.is_bytestr {
-            if let Ok(lint_str) = sess.source_map().span_to_snippet(self.span) {
-                diag.span_suggestion(
-                    self.span,
-                    fluent::attr::unsupported_literal_suggestion,
-                    &lint_str[1..],
-                    Applicability::MaybeIncorrect,
-                );
-            }
+            diag.span_suggestion(
+                sess.source_map().start_point(self.span),
+                fluent::attr::unsupported_literal_suggestion,
+                "",
+                Applicability::MaybeIncorrect,
+            );
         }
         diag
     }

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -1,5 +1,8 @@
-use rustc_errors::{Applicability, Diagnostic, DiagnosticBuilder, ErrorGuaranteed};
+use rustc_errors::{
+    Applicability, Diagnostic, DiagnosticBuilder, EmissionGuarantee, ErrorGuaranteed,
+};
 use rustc_hir as hir;
+use rustc_hir::intravisit::Visitor;
 use rustc_hir::Node;
 use rustc_middle::hir::map::Map;
 use rustc_middle::mir::{Mutability, Place, PlaceRef, ProjectionElem};
@@ -614,7 +617,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                             "trait `IndexMut` is required to modify indexed content, \
                                 but it is not implemented for `{ty}`",
                         ));
-                        self.suggest_map_index_mut_alternatives(ty, &mut err);
+                        self.suggest_map_index_mut_alternatives(ty, &mut err, span);
                     }
                     _ => (),
                 }
@@ -632,13 +635,120 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         &self,
         ty: Ty<'_>,
         err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>,
+        span: Span,
     ) {
         let Some(adt) = ty.ty_adt_def() else { return };
         let did = adt.did();
         if self.infcx.tcx.is_diagnostic_item(sym::HashMap, did)
             || self.infcx.tcx.is_diagnostic_item(sym::BTreeMap, did)
         {
-            err.help(format!("to modify a `{ty}`, use `.get_mut()`, `.insert()` or the entry API"));
+            struct V<'a, 'b, 'tcx, G: EmissionGuarantee> {
+                assign_span: Span,
+                err: &'a mut DiagnosticBuilder<'b, G>,
+                ty: Ty<'tcx>,
+                suggested: bool,
+            }
+            impl<'a, 'b: 'a, 'hir, 'tcx, G: EmissionGuarantee> Visitor<'hir> for V<'a, 'b, 'tcx, G> {
+                fn visit_stmt(&mut self, stmt: &'hir hir::Stmt<'hir>) {
+                    hir::intravisit::walk_stmt(self, stmt);
+                    let expr = match stmt.kind {
+                        hir::StmtKind::Semi(expr) | hir::StmtKind::Expr(expr) => expr,
+                        hir::StmtKind::Local(hir::Local { init: Some(expr), .. }) => expr,
+                        _ => {
+                            return;
+                        }
+                    };
+                    if let hir::ExprKind::Assign(place, rv, _sp) = expr.kind
+                        && let hir::ExprKind::Index(val, index) = place.kind
+                        && (expr.span == self.assign_span || place.span == self.assign_span)
+                    {
+                        // val[index] = rv;
+                        // ---------- place
+                        self.err.multipart_suggestions(
+                            &format!(
+                                "to modify a `{}`, use `.get_mut()`, `.insert()` or the entry API",
+                                self.ty,
+                            ),
+                            vec![
+                                vec![ // val.insert(index, rv);
+                                    (
+                                        val.span.shrink_to_hi().with_hi(index.span.lo()),
+                                        ".insert(".to_string(),
+                                    ),
+                                    (
+                                        index.span.shrink_to_hi().with_hi(rv.span.lo()),
+                                        ", ".to_string(),
+                                    ),
+                                    (rv.span.shrink_to_hi(), ")".to_string()),
+                                ],
+                                vec![ // val.get_mut(index).map(|v| { *v = rv; });
+                                    (
+                                        val.span.shrink_to_hi().with_hi(index.span.lo()),
+                                        ".get_mut(".to_string(),
+                                    ),
+                                    (
+                                        index.span.shrink_to_hi().with_hi(place.span.hi()),
+                                        ").map(|val| { *val".to_string(),
+                                    ),
+                                    (
+                                        rv.span.shrink_to_hi(),
+                                        "; })".to_string(),
+                                    ),
+                                ],
+                                vec![ // let x = val.entry(index).or_insert(rv);
+                                    (val.span.shrink_to_lo(), "let val = ".to_string()),
+                                    (
+                                        val.span.shrink_to_hi().with_hi(index.span.lo()),
+                                        ".entry(".to_string(),
+                                    ),
+                                    (
+                                        index.span.shrink_to_hi().with_hi(rv.span.lo()),
+                                        ").or_insert(".to_string(),
+                                    ),
+                                    (rv.span.shrink_to_hi(), ")".to_string()),
+                                ],
+                            ].into_iter(),
+                            Applicability::MachineApplicable,
+                        );
+                        self.suggested = true;
+                    } else if let hir::ExprKind::MethodCall(_path, args @ [_, ..], sp) = expr.kind
+                        && let hir::ExprKind::Index(val, index) = args[0].kind
+                        && expr.span == self.assign_span
+                    {
+                        // val[index].path(args..);
+                        self.err.multipart_suggestion(
+                            &format!("to modify a `{}` use `.get_mut()`", self.ty),
+                            vec![
+                                (
+                                    val.span.shrink_to_hi().with_hi(index.span.lo()),
+                                    ".get_mut(".to_string(),
+                                ),
+                                (
+                                    index.span.shrink_to_hi().with_hi(args[0].span.hi()),
+                                    ").map(|val| val".to_string(),
+                                ),
+                                (sp.shrink_to_hi(), ")".to_string()),
+                            ],
+                            Applicability::MachineApplicable,
+                        );
+                        self.suggested = true;
+                    }
+                }
+            }
+            let hir_map = self.infcx.tcx.hir();
+            let def_id = self.body.source.def_id();
+            let hir_id = hir_map.local_def_id_to_hir_id(def_id.as_local().unwrap());
+            let node = hir_map.find(hir_id);
+            let Some(hir::Node::Item(item)) = node else { return; };
+            let hir::ItemKind::Fn(.., body_id) = item.kind else { return; };
+            let body = self.infcx.tcx.hir().body(body_id);
+            let mut v = V { assign_span: span, err, ty, suggested: false };
+            v.visit_body(body);
+            if !v.suggested {
+                err.help(&format!(
+                    "to modify a `{ty}`, use `.get_mut()`, `.insert()` or the entry API",
+                ));
+            }
         }
     }
 

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -1500,24 +1500,18 @@ fn vcall_visibility_metadata<'ll, 'tcx>(
         // If there is not LTO and the visibility in public, we have to assume that the vtable can
         // be seen from anywhere. With multiple CGUs, the vtable is quasi-public.
         (Lto::No | Lto::ThinLocal, Visibility::Public, _)
-        | (Lto::No, Visibility::Restricted(_) | Visibility::Invisible, false) => {
-            VCallVisibility::Public
-        }
+        | (Lto::No, Visibility::Restricted(_), false) => VCallVisibility::Public,
         // With LTO and a quasi-public visibility, the usages of the functions of the vtable are
         // all known by the `LinkageUnit`.
         // FIXME: LLVM only supports this optimization for `Lto::Fat` currently. Once it also
         // supports `Lto::Thin` the `VCallVisibility` may have to be adjusted for those.
         (Lto::Fat | Lto::Thin, Visibility::Public, _)
-        | (
-            Lto::ThinLocal | Lto::Thin | Lto::Fat,
-            Visibility::Restricted(_) | Visibility::Invisible,
-            false,
-        ) => VCallVisibility::LinkageUnit,
+        | (Lto::ThinLocal | Lto::Thin | Lto::Fat, Visibility::Restricted(_), false) => {
+            VCallVisibility::LinkageUnit
+        }
         // If there is only one CGU, private vtables can only be seen by that CGU/translation unit
         // and therefore we know of all usages of functions in the vtable.
-        (_, Visibility::Restricted(_) | Visibility::Invisible, true) => {
-            VCallVisibility::TranslationUnit
-        }
+        (_, Visibility::Restricted(_), true) => VCallVisibility::TranslationUnit,
     };
 
     let trait_ref_typeid = typeid_for_trait_ref(cx.tcx, trait_ref);

compiler/rustc_const_eval/src/const_eval/eval_queries.rs

@@ -74,7 +74,9 @@ fn eval_body_using_ecx<'mir, 'tcx>(
             None => InternKind::Constant,
         }
     };
+    ecx.machine.check_alignment = false; // interning doesn't need to respect alignment
     intern_const_alloc_recursive(ecx, intern_kind, &ret)?;
+    // we leave alignment checks off, since this `ecx` will not be used for further evaluation anyway
 
     debug!("eval_body_using_ecx done: {:?}", *ret);
     Ok(ret)

compiler/rustc_const_eval/src/const_eval/machine.rs

@@ -89,10 +89,10 @@ pub struct CompileTimeInterpreter<'mir, 'tcx> {
     /// exhaustion error.
     ///
     /// Setting this to `0` disables the limit and allows the interpreter to run forever.
-    pub steps_remaining: usize,
+    pub(super) steps_remaining: usize,
 
     /// The virtual call stack.
-    pub(crate) stack: Vec<Frame<'mir, 'tcx, AllocId, ()>>,
+    pub(super) stack: Vec<Frame<'mir, 'tcx, AllocId, ()>>,
 
     /// We need to make sure consts never point to anything mutable, even recursively. That is
     /// relied on for pattern matching on consts with references.
@@ -103,7 +103,7 @@ pub struct CompileTimeInterpreter<'mir, 'tcx> {
     pub(super) can_access_statics: bool,
 
     /// Whether to check alignment during evaluation.
-    check_alignment: bool,
+    pub(super) check_alignment: bool,
 }
 
 impl<'mir, 'tcx> CompileTimeInterpreter<'mir, 'tcx> {

compiler/rustc_middle/src/middle/stability.rs

@@ -293,7 +293,7 @@ fn skip_stability_check_due_to_privacy(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
 
         // These are not visible outside crate; therefore
         // stability markers are irrelevant, if even present.
-        ty::Visibility::Restricted(..) | ty::Visibility::Invisible => true,
+        ty::Visibility::Restricted(..) => true,
     }
 }
 

compiler/rustc_middle/src/ty/inhabitedness/mod.rs

@@ -169,14 +169,10 @@ impl<'tcx> FieldDef {
         param_env: ty::ParamEnv<'tcx>,
     ) -> DefIdForest<'tcx> {
         let data_uninhabitedness = move || self.ty(tcx, substs).uninhabited_from(tcx, param_env);
-        // FIXME(canndrew): Currently enum fields are (incorrectly) stored with
-        // `Visibility::Invisible` so we need to override `self.vis` if we're
-        // dealing with an enum.
         if is_enum {
             data_uninhabitedness()
         } else {
             match self.vis {
-                Visibility::Invisible => DefIdForest::empty(),
                 Visibility::Restricted(from) => {
                     let forest = DefIdForest::from_id(from);
                     let iter = Some(forest).into_iter().chain(Some(data_uninhabitedness()));

compiler/rustc_middle/src/ty/mod.rs

@@ -268,8 +268,6 @@ pub enum Visibility {
     Public,
     /// Visible only in the given crate-local module.
     Restricted(DefId),
-    /// Not visible anywhere in the local crate. This is the visibility of private external items.
-    Invisible,
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
@@ -366,8 +364,6 @@ impl Visibility {
         let restriction = match self {
             // Public items are visible everywhere.
             Visibility::Public => return true,
-            // Private items from other crates are visible nowhere.
-            Visibility::Invisible => return false,
             // Restricted items are visible in an arbitrary local module.
             Visibility::Restricted(other) if other.krate != module.krate => return false,
             Visibility::Restricted(module) => module,
@@ -380,7 +376,6 @@ impl Visibility {
     pub fn is_at_least<T: DefIdTree>(self, vis: Visibility, tree: T) -> bool {
         let vis_restriction = match vis {
             Visibility::Public => return self == Visibility::Public,
-            Visibility::Invisible => return true,
             Visibility::Restricted(module) => module,
         };
 
@@ -392,7 +387,6 @@ impl Visibility {
         match self {
             Visibility::Public => true,
             Visibility::Restricted(def_id) => def_id.is_local(),
-            Visibility::Invisible => false,
         }
     }
 

compiler/rustc_privacy/src/lib.rs

@@ -1731,7 +1731,6 @@ impl SearchInterfaceForPrivateItemsVisitor<'_> {
         if !vis.is_at_least(self.required_visibility, self.tcx) {
             let vis_descr = match vis {
                 ty::Visibility::Public => "public",
-                ty::Visibility::Invisible => "private",
                 ty::Visibility::Restricted(vis_def_id) => {
                     if vis_def_id == self.tcx.parent_module(hir_id).to_def_id() {
                         "private"

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -380,7 +380,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             has_attributes: !item.attrs.is_empty(),
             root_span,
             root_id,
-            vis: Cell::new(vis),
+            vis: Cell::new(Some(vis)),
             used: Cell::new(false),
         });
 
@@ -588,7 +588,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             ast::UseTreeKind::Glob => {
                 let kind = ImportKind::Glob {
                     is_prelude: self.r.session.contains_name(&item.attrs, sym::prelude_import),
-                    max_vis: Cell::new(ty::Visibility::Invisible),
+                    max_vis: Cell::new(None),
                 };
                 self.r.visibilities.insert(self.r.local_def_id(id), vis);
                 self.add_import(prefix, kind, use_tree.span, id, item, root_span, item.id, vis);
@@ -650,7 +650,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                         true,
                         // The whole `use` item
                         item,
-                        ty::Visibility::Invisible,
+                        ty::Visibility::Restricted(self.parent_scope.module.nearest_parent_mod()),
                         root_span,
                     );
                 }
@@ -885,7 +885,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
             root_span: item.span,
             span: item.span,
             module_path: Vec::new(),
-            vis: Cell::new(vis),
+            vis: Cell::new(Some(vis)),
             used: Cell::new(used),
         });
         self.r.potentially_unused_imports.push(import);
@@ -1118,7 +1118,7 @@ impl<'a, 'b> BuildReducedGraphVisitor<'a, 'b> {
                 root_span: span,
                 span,
                 module_path: Vec::new(),
-                vis: Cell::new(ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id())),
+                vis: Cell::new(Some(ty::Visibility::Restricted(CRATE_DEF_ID.to_def_id()))),
                 used: Cell::new(false),
             })
         };

compiler/rustc_resolve/src/check_unused.rs

@@ -227,7 +227,7 @@ impl Resolver<'_> {
         for import in self.potentially_unused_imports.iter() {
             match import.kind {
                 _ if import.used.get()
-                    || import.vis.get().is_public()
+                    || import.expect_vis().is_public()
                     || import.span.is_dummy() =>
                 {
                     if let ImportKind::MacroUse = import.kind {

compiler/rustc_resolve/src/ident.rs

@@ -953,7 +953,10 @@ impl<'a> Resolver<'a> {
         // Check if one of single imports can still define the name,
         // if it can then our result is not determined and can be invalidated.
         for single_import in &resolution.single_imports {
-            if !self.is_accessible_from(single_import.vis.get(), parent_scope.module) {
+            let Some(import_vis) = single_import.vis.get() else {
+                continue;
+            };
+            if !self.is_accessible_from(import_vis, parent_scope.module) {
                 continue;
             }
             let Some(module) = single_import.imported_module.get() else {
@@ -1018,7 +1021,10 @@ impl<'a> Resolver<'a> {
         // Check if one of glob imports can still define the name,
         // if it can then our "no resolution" result is not determined and can be invalidated.
         for glob_import in module.globs.borrow().iter() {
-            if !self.is_accessible_from(glob_import.vis.get(), parent_scope.module) {
+            let Some(import_vis) = glob_import.vis.get() else {
+                continue;
+            };
+            if !self.is_accessible_from(import_vis, parent_scope.module) {
                 continue;
             }
             let module = match glob_import.imported_module.get() {