Rollup of 7 pull requests

compiler/rustc_ast_lowering/src/index.rs

@@ -412,8 +412,12 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
-    fn visit_pattern_type_pattern(&mut self, p: &'hir hir::Pat<'hir>) {
-        self.visit_pat(p)
+    fn visit_pattern_type_pattern(&mut self, pat: &'hir hir::TyPat<'hir>) {
+        self.insert(pat.span, pat.hir_id, Node::TyPat(pat));
+
+        self.with_parent(pat.hir_id, |this| {
+            intravisit::walk_ty_pat(this, pat);
+        });
     }
 
     fn visit_precise_capturing_arg(

compiler/rustc_ast_lowering/src/lib.rs

@@ -1377,7 +1377,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     }
                 }
             }
-            TyKind::Pat(ty, pat) => hir::TyKind::Pat(self.lower_ty(ty, itctx), self.lower_pat(pat)),
+            TyKind::Pat(ty, pat) => {
+                hir::TyKind::Pat(self.lower_ty(ty, itctx), self.lower_ty_pat(pat))
+            }
             TyKind::MacCall(_) => {
                 span_bug!(t.span, "`TyKind::MacCall` should have been expanded by now")
             }

compiler/rustc_ast_lowering/src/pat.rs

@@ -4,10 +4,10 @@ use rustc_ast::ptr::P;
 use rustc_ast::*;
 use rustc_data_structures::stack::ensure_sufficient_stack;
 use rustc_hir as hir;
-use rustc_hir::def::Res;
+use rustc_hir::def::{DefKind, Res};
 use rustc_middle::span_bug;
 use rustc_span::source_map::{Spanned, respan};
-use rustc_span::{Ident, Span};
+use rustc_span::{Ident, Span, kw};
 
 use super::errors::{
     ArbitraryExpressionInPattern, ExtraDoubleDot, MisplacedDoubleDot, SubTupleBinding,
@@ -429,4 +429,81 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         };
         self.arena.alloc(hir::PatExpr { hir_id: self.lower_node_id(expr.id), span, kind })
     }
+
+    pub(crate) fn lower_ty_pat(&mut self, pattern: &Pat) -> &'hir hir::TyPat<'hir> {
+        self.arena.alloc(self.lower_ty_pat_mut(pattern))
+    }
+
+    fn lower_ty_pat_mut(&mut self, mut pattern: &Pat) -> hir::TyPat<'hir> {
+        // loop here to avoid recursion
+        let pat_hir_id = self.lower_node_id(pattern.id);
+        let node = loop {
+            match &pattern.kind {
+                PatKind::Range(e1, e2, Spanned { node: end, .. }) => {
+                    // FIXME(pattern_types): remove this closure and call `lower_const_arg` instead.
+                    // That requires first modifying the AST to have const args here.
+                    let mut lower_expr = |e: &Expr| -> &_ {
+                        if let ExprKind::Path(None, path) = &e.kind
+                            && let Some(res) = self
+                                .resolver
+                                .get_partial_res(e.id)
+                                .and_then(|partial_res| partial_res.full_res())
+                        {
+                            self.lower_const_path_to_const_arg(path, res, e.id, e.span)
+                        } else {
+                            let node_id = self.next_node_id();
+                            let def_id = self.create_def(
+                                self.current_hir_id_owner.def_id,
+                                node_id,
+                                kw::Empty,
+                                DefKind::AnonConst,
+                                e.span,
+                            );
+                            let hir_id = self.lower_node_id(node_id);
+                            let ac = self.arena.alloc(hir::AnonConst {
+                                def_id,
+                                hir_id,
+                                body: self.lower_const_body(pattern.span, Some(e)),
+                                span: self.lower_span(pattern.span),
+                            });
+                            self.arena.alloc(hir::ConstArg {
+                                hir_id: self.next_id(),
+                                kind: hir::ConstArgKind::Anon(ac),
+                            })
+                        }
+                    };
+                    break hir::TyPatKind::Range(
+                        e1.as_deref().map(|e| lower_expr(e)),
+                        e2.as_deref().map(|e| lower_expr(e)),
+                        self.lower_range_end(end, e2.is_some()),
+                    );
+                }
+                // return inner to be processed in next loop
+                PatKind::Paren(inner) => pattern = inner,
+                PatKind::MacCall(_) => panic!("{:?} shouldn't exist here", pattern.span),
+                PatKind::Err(guar) => break hir::TyPatKind::Err(*guar),
+                PatKind::Deref(..)
+                | PatKind::Box(..)
+                | PatKind::Or(..)
+                | PatKind::Struct(..)
+                | PatKind::TupleStruct(..)
+                | PatKind::Tuple(..)
+                | PatKind::Ref(..)
+                | PatKind::Expr(..)
+                | PatKind::Guard(..)
+                | PatKind::Slice(_)
+                | PatKind::Ident(..)
+                | PatKind::Path(..)
+                | PatKind::Wild
+                | PatKind::Never
+                | PatKind::Rest => {
+                    break hir::TyPatKind::Err(
+                        self.dcx().span_err(pattern.span, "pattern not supported in pattern types"),
+                    );
+                }
+            }
+        };
+
+        hir::TyPat { hir_id: pat_hir_id, kind: node, span: self.lower_span(pattern.span) }
+    }
 }

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -3112,12 +3112,24 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             drop_span, borrow_span
         );
 
+        // `TerminatorKind::Return`'s span (the `drop_span` here) `lo` can be subtly wrong and point
+        // at a single character after the end of the function. This is somehow relied upon in
+        // existing diagnostics, and changing this in `rustc_mir_build` makes diagnostics worse in
+        // general. We fix these here.
+        let sm = self.infcx.tcx.sess.source_map();
+        let end_of_function = if drop_span.is_empty()
+            && let Ok(adjusted_span) = sm.span_extend_prev_while(drop_span, |c| c == '}')
+        {
+            adjusted_span
+        } else {
+            drop_span
+        };
         self.thread_local_value_does_not_live_long_enough(borrow_span)
             .with_span_label(
                 borrow_span,
                 "thread-local variables cannot be borrowed beyond the end of the function",
             )
-            .with_span_label(drop_span, "end of enclosing function is here")
+            .with_span_label(end_of_function, "end of enclosing function is here")
     }
 
     #[instrument(level = "debug", skip(self))]

compiler/rustc_driver_impl/src/pretty.rs

@@ -101,6 +101,10 @@ impl<'tcx> pprust_hir::PpAnn for HirIdentifiedAnn<'tcx> {
                 s.s.space();
                 s.synth_comment(format!("pat hir_id: {}", pat.hir_id));
             }
+            pprust_hir::AnnNode::TyPat(pat) => {
+                s.s.space();
+                s.synth_comment(format!("ty pat hir_id: {}", pat.hir_id));
+            }
             pprust_hir::AnnNode::Arm(arm) => {
                 s.s.space();
                 s.synth_comment(format!("arm hir_id: {}", arm.hir_id));

compiler/rustc_hir/src/hir.rs

@@ -1418,6 +1418,14 @@ impl<'hir> Block<'hir> {
     }
 }
 
+#[derive(Debug, Clone, Copy, HashStable_Generic)]
+pub struct TyPat<'hir> {
+    #[stable_hasher(ignore)]
+    pub hir_id: HirId,
+    pub kind: TyPatKind<'hir>,
+    pub span: Span,
+}
+
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub struct Pat<'hir> {
     #[stable_hasher(ignore)]
@@ -1591,6 +1599,15 @@ pub enum PatExprKind<'hir> {
     Path(QPath<'hir>),
 }
 
+#[derive(Debug, Clone, Copy, HashStable_Generic)]
+pub enum TyPatKind<'hir> {
+    /// A range pattern (e.g., `1..=2` or `1..2`).
+    Range(Option<&'hir ConstArg<'hir>>, Option<&'hir ConstArg<'hir>>, RangeEnd),
+
+    /// A placeholder for a pattern that wasn't well formed in some way.
+    Err(ErrorGuaranteed),
+}
+
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub enum PatKind<'hir> {
     /// Represents a wildcard pattern (i.e., `_`).
@@ -3384,7 +3401,7 @@ pub enum TyKind<'hir, Unambig = ()> {
     /// Placeholder for a type that has failed to be defined.
     Err(rustc_span::ErrorGuaranteed),
     /// Pattern types (`pattern_type!(u32 is 1..)`)
-    Pat(&'hir Ty<'hir>, &'hir Pat<'hir>),
+    Pat(&'hir Ty<'hir>, &'hir TyPat<'hir>),
     /// `TyKind::Infer` means the type should be inferred instead of it having been
     /// specified. This can appear anywhere in a type.
     ///
@@ -4370,6 +4387,7 @@ pub enum Node<'hir> {
     AssocItemConstraint(&'hir AssocItemConstraint<'hir>),
     TraitRef(&'hir TraitRef<'hir>),
     OpaqueTy(&'hir OpaqueTy<'hir>),
+    TyPat(&'hir TyPat<'hir>),
     Pat(&'hir Pat<'hir>),
     PatField(&'hir PatField<'hir>),
     /// Needed as its own node with its own HirId for tracking
@@ -4432,6 +4450,7 @@ impl<'hir> Node<'hir> {
             | Node::Block(..)
             | Node::Ctor(..)
             | Node::Pat(..)
+            | Node::TyPat(..)
             | Node::PatExpr(..)
             | Node::Arm(..)
             | Node::LetStmt(..)

compiler/rustc_hir/src/intravisit.rs

@@ -393,10 +393,8 @@ pub trait Visitor<'v>: Sized {
     fn visit_expr_field(&mut self, field: &'v ExprField<'v>) -> Self::Result {
         walk_expr_field(self, field)
     }
-    fn visit_pattern_type_pattern(&mut self, _p: &'v Pat<'v>) {
-        // Do nothing. Only a few visitors need to know the details of the pattern type,
-        // and they opt into it. All other visitors will just choke on our fake patterns
-        // because they aren't in a body.
+    fn visit_pattern_type_pattern(&mut self, p: &'v TyPat<'v>) -> Self::Result {
+        walk_ty_pat(self, p)
     }
     fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) -> Self::Result {
         walk_generic_param(self, p)
@@ -702,6 +700,18 @@ pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) -> V::Res
     visitor.visit_expr(arm.body)
 }
 
+pub fn walk_ty_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v TyPat<'v>) -> V::Result {
+    try_visit!(visitor.visit_id(pattern.hir_id));
+    match pattern.kind {
+        TyPatKind::Range(lower_bound, upper_bound, _) => {
+            visit_opt!(visitor, visit_const_arg_unambig, lower_bound);
+            visit_opt!(visitor, visit_const_arg_unambig, upper_bound);
+        }
+        TyPatKind::Err(_) => (),
+    }
+    V::Result::output()
+}
+
 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) -> V::Result {
     try_visit!(visitor.visit_id(pattern.hir_id));
     match pattern.kind {

compiler/rustc_hir_analysis/messages.ftl

@@ -436,9 +436,6 @@ hir_analysis_paren_sugar_attribute = the `#[rustc_paren_sugar]` attribute is a t
 hir_analysis_parenthesized_fn_trait_expansion =
     parenthesized trait syntax expands to `{$expanded_type}`
 
-hir_analysis_pattern_type_non_const_range = range patterns must have constant range start and end
-hir_analysis_pattern_type_wild_pat = wildcard patterns are not permitted for pattern types
-    .label = this type is the same as the inner type without a pattern
 hir_analysis_placeholder_not_allowed_item_signatures = the placeholder `_` is not allowed within types on item signatures for {$kind}
     .label = not allowed in type signatures
 hir_analysis_precise_capture_self_alias = `Self` can't be captured in `use<...>` precise captures list, since it is an alias

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1065,6 +1065,7 @@ fn check_associated_item(
                 let ty = tcx.type_of(item.def_id).instantiate_identity();
                 let ty = wfcx.normalize(span, Some(WellFormedLoc::Ty(item_id)), ty);
                 wfcx.register_wf_obligation(span, loc, ty.into());
+                check_sized_if_body(wfcx, item.def_id.expect_local(), ty, Some(span));
                 Ok(())
             }
             ty::AssocKind::Fn => {
@@ -1189,7 +1190,7 @@ fn check_type_defn<'tcx>(
                     ),
                     wfcx.param_env,
                     ty,
-                    tcx.require_lang_item(LangItem::Sized, None),
+                    tcx.require_lang_item(LangItem::Sized, Some(hir_ty.span)),
                 );
             }
 
@@ -1314,7 +1315,7 @@ fn check_item_type(
                 ),
                 wfcx.param_env,
                 item_ty,
-                tcx.require_lang_item(LangItem::Sized, None),
+                tcx.require_lang_item(LangItem::Sized, Some(ty_span)),
             );
         }
 
@@ -1644,6 +1645,31 @@ fn check_fn_or_method<'tcx>(
             );
         }
     }
+
+    // If the function has a body, additionally require that the return type is sized.
+    check_sized_if_body(wfcx, def_id, sig.output(), match hir_decl.output {
+        hir::FnRetTy::Return(ty) => Some(ty.span),
+        hir::FnRetTy::DefaultReturn(_) => None,
+    });
+}
+
+fn check_sized_if_body<'tcx>(
+    wfcx: &WfCheckingCtxt<'_, 'tcx>,
+    def_id: LocalDefId,
+    ty: Ty<'tcx>,
+    maybe_span: Option<Span>,
+) {
+    let tcx = wfcx.tcx();
+    if let Some(body) = tcx.hir().maybe_body_owned_by(def_id) {
+        let span = maybe_span.unwrap_or(body.value.span);
+
+        wfcx.register_bound(
+            ObligationCause::new(span, def_id, traits::ObligationCauseCode::SizedReturnType),
+            wfcx.param_env,
+            ty,
+            tcx.require_lang_item(LangItem::Sized, Some(span)),
+        );
+    }
 }
 
 /// The `arbitrary_self_types_pointers` feature implies `arbitrary_self_types`.

compiler/rustc_hir_analysis/src/collect/generics_of.rs

@@ -198,6 +198,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
                     {
                         Some(parent_did)
                     }
+                    Node::TyPat(_) => Some(parent_did),
                     _ => None,
                 }
             }

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -831,8 +831,8 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
     }
 
     #[instrument(level = "debug", skip(self))]
-    fn visit_pattern_type_pattern(&mut self, p: &'tcx hir::Pat<'tcx>) {
-        intravisit::walk_pat(self, p)
+    fn visit_pattern_type_pattern(&mut self, p: &'tcx hir::TyPat<'tcx>) {
+        intravisit::walk_ty_pat(self, p)
     }
 
     #[instrument(level = "debug", skip(self))]

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -18,9 +18,10 @@ use crate::hir_ty_lowering::HirTyLowerer;
 
 mod opaque;
 
-fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
+fn anon_const_type_of<'tcx>(icx: &ItemCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
     use hir::*;
     use rustc_middle::ty::Ty;
+    let tcx = icx.tcx;
     let hir_id = tcx.local_def_id_to_hir_id(def_id);
 
     let node = tcx.hir_node(hir_id);
@@ -54,7 +55,7 @@ fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
             hir_id: arg_hir_id,
             kind: ConstArgKind::Anon(&AnonConst { hir_id: anon_hir_id, .. }),
             ..
-        }) if anon_hir_id == hir_id => const_arg_anon_type_of(tcx, arg_hir_id, span),
+        }) if anon_hir_id == hir_id => const_arg_anon_type_of(icx, arg_hir_id, span),
 
         // Anon consts outside the type system.
         Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
@@ -138,18 +139,28 @@ fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
     }
 }
 
-fn const_arg_anon_type_of<'tcx>(tcx: TyCtxt<'tcx>, arg_hir_id: HirId, span: Span) -> Ty<'tcx> {
+fn const_arg_anon_type_of<'tcx>(icx: &ItemCtxt<'tcx>, arg_hir_id: HirId, span: Span) -> Ty<'tcx> {
     use hir::*;
     use rustc_middle::ty::Ty;
 
+    let tcx = icx.tcx;
+
     match tcx.parent_hir_node(arg_hir_id) {
         // Array length const arguments do not have `type_of` fed as there is never a corresponding
         // generic parameter definition.
         Node::Ty(&hir::Ty { kind: TyKind::Array(_, ref constant), .. })
         | Node::Expr(&Expr { kind: ExprKind::Repeat(_, ref constant), .. })
             if constant.hir_id == arg_hir_id =>
         {
-            return tcx.types.usize;
+            tcx.types.usize
+        }
+
+        Node::TyPat(pat) => {
+            let hir::TyKind::Pat(ty, p) = tcx.parent_hir_node(pat.hir_id).expect_ty().kind else {
+                bug!()
+            };
+            assert_eq!(p.hir_id, pat.hir_id);
+            icx.lower_ty(ty)
         }
 
         // This is not a `bug!` as const arguments in path segments that did not resolve to anything
@@ -344,7 +355,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<'_
             tcx.typeck(def_id).node_type(hir_id)
         }
 
-        Node::AnonConst(_) => anon_const_type_of(tcx, def_id),
+        Node::AnonConst(_) => anon_const_type_of(&icx, def_id),
 
         Node::ConstBlock(_) => {
             let args = ty::GenericArgs::identity_for_item(tcx, def_id.to_def_id());