Auto merge of #154192 - JonathanBrouwer:rollup-TkGjSDo, r=JonathanBrouwer

Rollup of 7 pull requests

Successful merges:

 - #122668 (Add APIs for dealing with titlecase)
 - #153312 (Packages as namespaces part 1)
 - #153534 (Remove a flaky `got_timeout` assert from two channel tests)
 - #154094 (add neon load/store assembly test)
 - #154175 (Add new alias for Guillaume Gomez email address)
 - #154182 (diagnostics: avoid ICE for undeclared generic parameter in impl)
 - #154188 (Update the tracking issue for #[diagnostic::on_move])

Author: bors

.mailmap

@@ -262,6 +262,7 @@ Guillaume Gomez <guillaume1.gomez@gmail.com>
 Guillaume Gomez <guillaume1.gomez@gmail.com> ggomez <ggomez@ggo.ifr.lan>
 Guillaume Gomez <guillaume1.gomez@gmail.com> Guillaume Gomez <ggomez@ggo.ifr.lan>
 Guillaume Gomez <guillaume1.gomez@gmail.com> Guillaume Gomez <guillaume.gomez@huawei.com>
+Guillaume Gomez <guillaume1.gomez@gmail.com> Guillaume Gomez <contact@guillaume-gomez.fr>
 gnzlbg <gonzalobg88@gmail.com> <gnzlbg@users.noreply.github.com>
 hamidreza kalbasi <hamidrezakalbasi@protonmail.com>
 Hanna Kruppe <hanna.kruppe@gmail.com> <robin.kruppe@gmail.com>

compiler/rustc_feature/src/unstable.rs

@@ -473,7 +473,7 @@ declare_features! (
     /// Allows giving non-const impls custom diagnostic messages if attempted to be used as const
     (unstable, diagnostic_on_const, "1.93.0", Some(143874)),
     /// Allows giving on-move borrowck custom diagnostic messages for a type
-    (unstable, diagnostic_on_move, "CURRENT_RUSTC_VERSION", Some(150935)),
+    (unstable, diagnostic_on_move, "CURRENT_RUSTC_VERSION", Some(154181)),
     /// Allows `#[doc(cfg(...))]`.
     (unstable, doc_cfg, "1.21.0", Some(43781)),
     /// Allows `#[doc(masked)]`.

compiler/rustc_hir/src/def.rs

@@ -590,6 +590,13 @@ pub enum Res<Id = hir::HirId> {
     /// **Belongs to the type namespace.**
     ToolMod,
 
+    /// The resolution for an open module in a namespaced crate. E.g. `my_api`
+    /// in the namespaced crate `my_api::utils` when `my_api` isn't part of the
+    /// extern prelude.
+    ///
+    /// **Belongs to the type namespace.**
+    OpenMod(Symbol),
+
     // Macro namespace
     /// An attribute that is *not* implemented via macro.
     /// E.g., `#[inline]` and `#[rustfmt::skip]`, which are essentially directives,
@@ -838,6 +845,7 @@ impl<Id> Res<Id> {
             | Res::SelfTyAlias { .. }
             | Res::SelfCtor(..)
             | Res::ToolMod
+            | Res::OpenMod(..)
             | Res::NonMacroAttr(..)
             | Res::Err => None,
         }
@@ -869,6 +877,7 @@ impl<Id> Res<Id> {
             Res::Local(..) => "local variable",
             Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } => "self type",
             Res::ToolMod => "tool module",
+            Res::OpenMod(..) => "namespaced crate",
             Res::NonMacroAttr(attr_kind) => attr_kind.descr(),
             Res::Err => "unresolved item",
         }
@@ -895,6 +904,7 @@ impl<Id> Res<Id> {
                 Res::SelfTyAlias { alias_to, is_trait_impl }
             }
             Res::ToolMod => Res::ToolMod,
+            Res::OpenMod(sym) => Res::OpenMod(sym),
             Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),
             Res::Err => Res::Err,
         }
@@ -911,6 +921,7 @@ impl<Id> Res<Id> {
                 Res::SelfTyAlias { alias_to, is_trait_impl }
             }
             Res::ToolMod => Res::ToolMod,
+            Res::OpenMod(sym) => Res::OpenMod(sym),
             Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),
             Res::Err => Res::Err,
         })
@@ -936,9 +947,11 @@ impl<Id> Res<Id> {
     pub fn ns(&self) -> Option<Namespace> {
         match self {
             Res::Def(kind, ..) => kind.ns(),
-            Res::PrimTy(..) | Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } | Res::ToolMod => {
-                Some(Namespace::TypeNS)
-            }
+            Res::PrimTy(..)
+            | Res::SelfTyParam { .. }
+            | Res::SelfTyAlias { .. }
+            | Res::ToolMod
+            | Res::OpenMod(..) => Some(Namespace::TypeNS),
             Res::SelfCtor(..) | Res::Local(..) => Some(Namespace::ValueNS),
             Res::NonMacroAttr(..) => Some(Namespace::MacroNS),
             Res::Err => None,

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -2830,6 +2830,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             | Res::SelfCtor(_)
             | Res::Local(_)
             | Res::ToolMod
+            | Res::OpenMod(..)
             | Res::NonMacroAttr(_)
             | Res::Err) => Const::new_error_with_message(
                 tcx,

compiler/rustc_passes/src/dead.rs

@@ -157,7 +157,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
             Res::Def(_, def_id) => self.check_def_id(def_id),
             Res::SelfTyParam { trait_: t } => self.check_def_id(t),
             Res::SelfTyAlias { alias_to: i, .. } => self.check_def_id(i),
-            Res::ToolMod | Res::NonMacroAttr(..) | Res::Err => {}
+            Res::ToolMod | Res::NonMacroAttr(..) | Res::OpenMod(..) | Res::Err => {}
         }
     }
 

compiler/rustc_resolve/src/build_reduced_graph.rs

@@ -357,6 +357,7 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             | Res::SelfTyParam { .. }
             | Res::SelfTyAlias { .. }
             | Res::SelfCtor(..)
+            | Res::OpenMod(..)
             | Res::Err => bug!("unexpected resolution: {:?}", res),
         }
     }

compiler/rustc_resolve/src/diagnostics.rs

@@ -1740,8 +1740,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                 Res::Def(DefKind::Macro(kinds), _) => {
                     format!("{} {}", kinds.article(), kinds.descr())
                 }
-                Res::ToolMod => {
-                    // Don't confuse the user with tool modules.
+                Res::ToolMod | Res::OpenMod(..) => {
+                    // Don't confuse the user with tool modules or open modules.
                     continue;
                 }
                 Res::Def(DefKind::Trait, _) if macro_kind == MacroKind::Derive => {
@@ -1978,7 +1978,8 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
             let (built_in, from) = match scope {
                 Scope::StdLibPrelude | Scope::MacroUsePrelude => ("", " from prelude"),
                 Scope::ExternPreludeFlags
-                    if self.tcx.sess.opts.externs.get(ident.as_str()).is_some() =>
+                    if self.tcx.sess.opts.externs.get(ident.as_str()).is_some()
+                        || matches!(res, Res::OpenMod(..)) =>
                 {
                     ("", " passed with `--extern`")
                 }

compiler/rustc_resolve/src/ident.rs

@@ -26,7 +26,7 @@ use crate::{
     AmbiguityError, AmbiguityKind, AmbiguityWarning, BindingKey, CmResolver, Decl, DeclKind,
     Determinacy, Finalize, IdentKey, ImportKind, LateDecl, Module, ModuleKind, ModuleOrUniformRoot,
     ParentScope, PathResult, PrivacyError, Res, ResolutionError, Resolver, Scope, ScopeSet,
-    Segment, Stage, Used, errors,
+    Segment, Stage, Symbol, Used, errors,
 };
 
 #[derive(Copy, Clone)]
@@ -386,7 +386,6 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
     }
 
     /// Resolve an identifier in the specified set of scopes.
-    #[instrument(level = "debug", skip(self))]
     pub(crate) fn resolve_ident_in_scope_set<'r>(
         self: CmResolver<'r, 'ra, 'tcx>,
         orig_ident: Ident,
@@ -976,6 +975,14 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     ignore_import,
                 )
             }
+            ModuleOrUniformRoot::OpenModule(sym) => {
+                let open_ns_name = format!("{}::{}", sym.as_str(), ident.name);
+                let ns_ident = IdentKey::with_root_ctxt(Symbol::intern(&open_ns_name));
+                match self.extern_prelude_get_flag(ns_ident, ident.span, finalize.is_some()) {
+                    Some(decl) => Ok(decl),
+                    None => Err(Determinacy::Determined),
+                }
+            }
             ModuleOrUniformRoot::ModuleAndExternPrelude(module) => self.resolve_ident_in_scope_set(
                 ident,
                 ScopeSet::ModuleAndExternPrelude(ns, module),
@@ -1962,7 +1969,10 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> {
                     }
 
                     let maybe_assoc = opt_ns != Some(MacroNS) && PathSource::Type.is_expected(res);
-                    if let Some(def_id) = binding.res().module_like_def_id() {
+                    if let Res::OpenMod(sym) = binding.res() {
+                        module = Some(ModuleOrUniformRoot::OpenModule(sym));
+                        record_segment_res(self.reborrow(), finalize, res, id);
+                    } else if let Some(def_id) = binding.res().module_like_def_id() {
                         if self.mods_with_parse_errors.contains(&def_id) {
                             module_had_parse_errors = true;
                         }

compiler/rustc_resolve/src/imports.rs

@@ -41,7 +41,7 @@ type Res = def::Res<NodeId>;
 
 /// A potential import declaration in the process of being planted into a module.
 /// Also used for lazily planting names from `--extern` flags to extern prelude.
-#[derive(Clone, Copy, Default, PartialEq)]
+#[derive(Clone, Copy, Default, PartialEq, Debug)]
 pub(crate) enum PendingDecl<'ra> {
     Ready(Option<Decl<'ra>>),
     #[default]

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -3381,7 +3381,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             && def_id.is_local()
             && let Some(local_def_id) = def_id.as_local()
             && let Some(struct_generics) = self.r.struct_generics.get(&local_def_id)
-            && let target_param = &struct_generics.params[idx]
+            && let Some(target_param) = &struct_generics.params.get(idx)
             && let GenericParamKind::Const { ty, .. } = &target_param.kind
             && let TyKind::Path(_, path) = &ty.kind
         {