Exhaustively handle expressions in patterns

16 files changed, 248 insertions, 111 deletions

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index d16a3ce390d..a76ca6772e5 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -102,17 +102,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
 
             let kind = match &e.kind {
                 ExprKind::Array(exprs) => hir::ExprKind::Array(self.lower_exprs(exprs)),
-                ExprKind::ConstBlock(c) => {
-                    let c = self.with_new_scopes(c.value.span, |this| {
-                        let def_id = this.local_def_id(c.id);
-                        hir::ConstBlock {
-                            def_id,
-                            hir_id: this.lower_node_id(c.id),
-                            body: this.lower_const_body(c.value.span, Some(&c.value)),
-                        }
-                    });
-                    hir::ExprKind::ConstBlock(c)
-                }
+                ExprKind::ConstBlock(c) => hir::ExprKind::ConstBlock(self.lower_const_block(c)),
                 ExprKind::Repeat(expr, count) => {
                     let expr = self.lower_expr(expr);
                     let count = self.lower_array_length_to_const_arg(count);
@@ -153,18 +143,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                     let ohs = self.lower_expr(ohs);
                     hir::ExprKind::Unary(op, ohs)
                 }
-                ExprKind::Lit(token_lit) => {
-                    let lit_kind = match LitKind::from_token_lit(*token_lit) {
-                        Ok(lit_kind) => lit_kind,
-                        Err(err) => {
-                            let guar =
-                                report_lit_error(&self.tcx.sess.psess, err, *token_lit, e.span);
-                            LitKind::Err(guar)
-                        }
-                    };
-                    let lit = self.arena.alloc(respan(self.lower_span(e.span), lit_kind));
-                    hir::ExprKind::Lit(lit)
-                }
+                ExprKind::Lit(token_lit) => hir::ExprKind::Lit(self.lower_lit(token_lit, e.span)),
                 ExprKind::IncludedBytes(bytes) => {
                     let lit = self.arena.alloc(respan(
                         self.lower_span(e.span),
@@ -403,6 +382,32 @@ impl<'hir> LoweringContext<'_, 'hir> {
         })
     }
 
+    pub(crate) fn lower_const_block(&mut self, c: &AnonConst) -> hir::ConstBlock {
+        self.with_new_scopes(c.value.span, |this| {
+            let def_id = this.local_def_id(c.id);
+            hir::ConstBlock {
+                def_id,
+                hir_id: this.lower_node_id(c.id),
+                body: this.lower_const_body(c.value.span, Some(&c.value)),
+            }
+        })
+    }
+
+    pub(crate) fn lower_lit(
+        &mut self,
+        token_lit: &token::Lit,
+        span: Span,
+    ) -> &'hir Spanned<LitKind> {
+        let lit_kind = match LitKind::from_token_lit(*token_lit) {
+            Ok(lit_kind) => lit_kind,
+            Err(err) => {
+                let guar = report_lit_error(&self.tcx.sess.psess, err, *token_lit, span);
+                LitKind::Err(guar)
+            }
+        };
+        self.arena.alloc(respan(self.lower_span(span), lit_kind))
+    }
+
     fn lower_unop(&mut self, u: UnOp) -> hir::UnOp {
         match u {
             UnOp::Deref => hir::UnOp::Deref,
diff --git a/compiler/rustc_ast_lowering/src/index.rs b/compiler/rustc_ast_lowering/src/index.rs
index c3ff7b4b897..29d4fb9ef25 100644
--- a/compiler/rustc_ast_lowering/src/index.rs
+++ b/compiler/rustc_ast_lowering/src/index.rs
@@ -209,6 +209,14 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
+    fn visit_pat_expr(&mut self, expr: &'hir PatExpr<'hir>) {
+        self.insert(expr.span, expr.hir_id, Node::PatExpr(expr));
+
+        self.with_parent(expr.hir_id, |this| {
+            intravisit::walk_pat_expr(this, expr);
+        });
+    }
+
     fn visit_pat_field(&mut self, field: &'hir PatField<'hir>) {
         self.insert(field.span, field.hir_id, Node::PatField(field));
         self.with_parent(field.hir_id, |this| {
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
index fe2d5a594f3..0e28590bd66 100644
--- a/compiler/rustc_ast_lowering/src/lib.rs
+++ b/compiler/rustc_ast_lowering/src/lib.rs
@@ -35,6 +35,7 @@
 #![doc(rust_logo)]
 #![feature(assert_matches)]
 #![feature(box_patterns)]
+#![feature(if_let_guard)]
 #![feature(let_chains)]
 #![feature(rustdoc_internals)]
 #![warn(unreachable_pub)]
diff --git a/compiler/rustc_ast_lowering/src/pat.rs b/compiler/rustc_ast_lowering/src/pat.rs
index 40e7d6430fd..27b8bdefb05 100644
--- a/compiler/rustc_ast_lowering/src/pat.rs
+++ b/compiler/rustc_ast_lowering/src/pat.rs
@@ -1,9 +1,12 @@
+use std::sync::Arc;
+
 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_span::source_map::Spanned;
+use rustc_middle::span_bug;
+use rustc_span::source_map::{Spanned, respan};
 use rustc_span::{Ident, Span};
 
 use super::errors::{
@@ -367,24 +370,54 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
     // }
     // m!(S);
     // ```
-    fn lower_expr_within_pat(&mut self, expr: &Expr, allow_paths: bool) -> &'hir hir::Expr<'hir> {
-        match &expr.kind {
-            ExprKind::Lit(..)
-            | ExprKind::ConstBlock(..)
-            | ExprKind::IncludedBytes(..)
-            | ExprKind::Err(_)
-            | ExprKind::Dummy => {}
-            ExprKind::Path(..) if allow_paths => {}
-            ExprKind::Unary(UnOp::Neg, inner) if matches!(inner.kind, ExprKind::Lit(_)) => {}
+    fn lower_expr_within_pat(
+        &mut self,
+        expr: &Expr,
+        allow_paths: bool,
+    ) -> &'hir hir::PatExpr<'hir> {
+        let err = |guar| hir::PatExprKind::Lit {
+            lit: self.arena.alloc(respan(self.lower_span(expr.span), LitKind::Err(guar))),
+            negated: false,
+        };
+        let kind = match &expr.kind {
+            ExprKind::Lit(lit) => {
+                hir::PatExprKind::Lit { lit: self.lower_lit(lit, expr.span), negated: false }
+            }
+            ExprKind::ConstBlock(c) => hir::PatExprKind::ConstBlock(self.lower_const_block(c)),
+            ExprKind::IncludedBytes(bytes) => hir::PatExprKind::Lit {
+                lit: self.arena.alloc(respan(
+                    self.lower_span(expr.span),
+                    LitKind::ByteStr(Arc::clone(bytes), StrStyle::Cooked),
+                )),
+                negated: false,
+            },
+            ExprKind::Err(guar) => err(*guar),
+            ExprKind::Dummy => span_bug!(expr.span, "lowered ExprKind::Dummy"),
+            ExprKind::Path(qself, path) if allow_paths => hir::PatExprKind::Path(self.lower_qpath(
+                expr.id,
+                qself,
+                path,
+                ParamMode::Optional,
+                AllowReturnTypeNotation::No,
+                ImplTraitContext::Disallowed(ImplTraitPosition::Path),
+                None,
+            )),
+            ExprKind::Unary(UnOp::Neg, inner) if let ExprKind::Lit(lit) = &inner.kind => {
+                hir::PatExprKind::Lit { lit: self.lower_lit(lit, expr.span), negated: true }
+            }
             _ => {
                 let pattern_from_macro = expr.is_approximately_pattern();
                 let guar = self.dcx().emit_err(ArbitraryExpressionInPattern {
                     span: expr.span,
                     pattern_from_macro_note: pattern_from_macro,
                 });
-                return self.arena.alloc(self.expr_err(expr.span, guar));
+                err(guar)
             }
-        }
-        self.lower_expr(expr)
+        };
+        self.arena.alloc(hir::PatExpr {
+            hir_id: self.lower_node_id(expr.id),
+            span: expr.span,
+            kind,
+        })
     }
 }
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 2e4b6748731..4d452d6cb37 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -1520,6 +1520,26 @@ impl fmt::Debug for DotDotPos {
 }
 
 #[derive(Debug, Clone, Copy, HashStable_Generic)]
+pub struct PatExpr<'hir> {
+    pub hir_id: HirId,
+    pub span: Span,
+    pub kind: PatExprKind<'hir>,
+}
+
+#[derive(Debug, Clone, Copy, HashStable_Generic)]
+pub enum PatExprKind<'hir> {
+    Lit {
+        lit: &'hir Lit,
+        // FIXME: move this into `Lit` and handle negated literal expressions
+        // once instead of matching on unop neg expressions everywhere.
+        negated: bool,
+    },
+    ConstBlock(ConstBlock),
+    /// A path pattern for a unit struct/variant or a (maybe-associated) constant.
+    Path(QPath<'hir>),
+}
+
+#[derive(Debug, Clone, Copy, HashStable_Generic)]
 pub enum PatKind<'hir> {
     /// Represents a wildcard pattern (i.e., `_`).
     Wild,
@@ -1564,13 +1584,13 @@ pub enum PatKind<'hir> {
     Ref(&'hir Pat<'hir>, Mutability),
 
     /// A literal.
-    Lit(&'hir Expr<'hir>),
+    Lit(&'hir PatExpr<'hir>),
 
     /// A guard pattern (e.g., `x if guard(x)`).
     Guard(&'hir Pat<'hir>, &'hir Expr<'hir>),
 
     /// A range pattern (e.g., `1..=2` or `1..2`).
-    Range(Option<&'hir Expr<'hir>>, Option<&'hir Expr<'hir>>, RangeEnd),
+    Range(Option<&'hir PatExpr<'hir>>, Option<&'hir PatExpr<'hir>>, RangeEnd),
 
     /// A slice pattern, `[before_0, ..., before_n, (slice, after_0, ..., after_n)?]`.
     ///
@@ -4144,6 +4164,10 @@ pub enum Node<'hir> {
     OpaqueTy(&'hir OpaqueTy<'hir>),
     Pat(&'hir Pat<'hir>),
     PatField(&'hir PatField<'hir>),
+    /// Needed as its own node with its own HirId for tracking
+    /// the unadjusted type of literals within patterns
+    /// (e.g. byte str literals not being of slice type).
+    PatExpr(&'hir PatExpr<'hir>),
     Arm(&'hir Arm<'hir>),
     Block(&'hir Block<'hir>),
     LetStmt(&'hir LetStmt<'hir>),
@@ -4200,6 +4224,7 @@ impl<'hir> Node<'hir> {
             | Node::Block(..)
             | Node::Ctor(..)
             | Node::Pat(..)
+            | Node::PatExpr(..)
             | Node::Arm(..)
             | Node::LetStmt(..)
             | Node::Crate(..)
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
index f0480afd139..b832843aa6e 100644
--- a/compiler/rustc_hir/src/intravisit.rs
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -342,6 +342,9 @@ pub trait Visitor<'v>: Sized {
     fn visit_pat_field(&mut self, f: &'v PatField<'v>) -> Self::Result {
         walk_pat_field(self, f)
     }
+    fn visit_pat_expr(&mut self, expr: &'v PatExpr<'v>) -> Self::Result {
+        walk_pat_expr(self, expr)
+    }
     fn visit_anon_const(&mut self, c: &'v AnonConst) -> Self::Result {
         walk_anon_const(self, c)
     }
@@ -685,10 +688,10 @@ pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) -> V:
             try_visit!(visitor.visit_ident(ident));
             visit_opt!(visitor, visit_pat, optional_subpattern);
         }
-        PatKind::Lit(ref expression) => try_visit!(visitor.visit_expr(expression)),
+        PatKind::Lit(ref expression) => try_visit!(visitor.visit_pat_expr(expression)),
         PatKind::Range(ref lower_bound, ref upper_bound, _) => {
-            visit_opt!(visitor, visit_expr, lower_bound);
-            visit_opt!(visitor, visit_expr, upper_bound);
+            visit_opt!(visitor, visit_pat_expr, lower_bound);
+            visit_opt!(visitor, visit_pat_expr, upper_bound);
         }
         PatKind::Never | PatKind::Wild | PatKind::Err(_) => (),
         PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
@@ -710,6 +713,15 @@ pub fn walk_pat_field<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v PatField<'
     visitor.visit_pat(field.pat)
 }
 
+pub fn walk_pat_expr<'v, V: Visitor<'v>>(visitor: &mut V, expr: &'v PatExpr<'v>) -> V::Result {
+    try_visit!(visitor.visit_id(expr.hir_id));
+    match &expr.kind {
+        PatExprKind::Lit { .. } => V::Result::output(),
+        PatExprKind::ConstBlock(c) => visitor.visit_inline_const(c),
+        PatExprKind::Path(qpath) => visitor.visit_qpath(qpath, expr.hir_id, expr.span),
+    }
+}
+
 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) -> V::Result {
     try_visit!(visitor.visit_id(constant.hir_id));
     visitor.visit_nested_body(constant.body)
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index 2154568c512..0a41dad0dd8 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -2449,17 +2449,11 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         Ty::new_error(tcx, err)
                     }
                     hir::PatKind::Range(start, end, include_end) => {
-                        let expr_to_const = |expr: &'tcx hir::Expr<'tcx>| -> ty::Const<'tcx> {
-                            let (expr, neg) = match expr.kind {
-                                hir::ExprKind::Unary(hir::UnOp::Neg, negated) => {
-                                    (negated, Some((expr.hir_id, expr.span)))
-                                }
-                                _ => (expr, None),
-                            };
-                            let (c, c_ty) = match &expr.kind {
-                                hir::ExprKind::Lit(lit) => {
+                        let expr_to_const = |expr: &'tcx hir::PatExpr<'tcx>| -> ty::Const<'tcx> {
+                            let (c, c_ty) = match expr.kind {
+                                hir::PatExprKind::Lit { lit, negated } => {
                                     let lit_input =
-                                        LitToConstInput { lit: &lit.node, ty, neg: neg.is_some() };
+                                        LitToConstInput { lit: &lit.node, ty, neg: negated };
                                     let ct = match tcx.lit_to_const(lit_input) {
                                         Ok(c) => c,
                                         Err(LitToConstError::Reported(err)) => {
@@ -2470,23 +2464,30 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                                     (ct, ty)
                                 }
 
-                                hir::ExprKind::Path(hir::QPath::Resolved(
+                                hir::PatExprKind::Path(hir::QPath::Resolved(
                                     _,
                                     path @ &hir::Path {
                                         res: Res::Def(DefKind::ConstParam, def_id),
                                         ..
                                     },
                                 )) => {
-                                    let _ = self.prohibit_generic_args(
+                                    match self.prohibit_generic_args(
                                         path.segments.iter(),
                                         GenericsArgsErrExtend::Param(def_id),
-                                    );
-                                    let ty = tcx
-                                        .type_of(def_id)
-                                        .no_bound_vars()
-                                        .expect("const parameter types cannot be generic");
-                                    let ct = self.lower_const_param(def_id, expr.hir_id);
-                                    (ct, ty)
+                                    ) {
+                                        Ok(()) => {
+                                            let ty = tcx
+                                                .type_of(def_id)
+                                                .no_bound_vars()
+                                                .expect("const parameter types cannot be generic");
+                                            let ct = self.lower_const_param(def_id, expr.hir_id);
+                                            (ct, ty)
+                                        }
+                                        Err(guar) => (
+                                            ty::Const::new_error(tcx, guar),
+                                            Ty::new_error(tcx, guar),
+                                        ),
+                                    }
                                 }
 
                                 _ => {
@@ -2497,9 +2498,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                                 }
                             };
                             self.record_ty(expr.hir_id, c_ty, expr.span);
-                            if let Some((id, span)) = neg {
-                                self.record_ty(id, c_ty, span);
-                            }
                             c
                         };
 
diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs
index 16bb0dd328c..632a12b2c3f 100644
--- a/compiler/rustc_hir_pretty/src/lib.rs
+++ b/compiler/rustc_hir_pretty/src/lib.rs
@@ -199,6 +199,7 @@ impl<'a> State<'a> {
             Node::OpaqueTy(o) => self.print_opaque_ty(o),
             Node::Pat(a) => self.print_pat(a),
             Node::PatField(a) => self.print_patfield(a),
+            Node::PatExpr(a) => self.print_pat_expr(a),
             Node::Arm(a) => self.print_arm(a),
             Node::Infer(_) => self.word("_"),
             Node::PreciseCapturingNonLifetimeArg(param) => self.print_ident(param.ident),
@@ -1849,6 +1850,19 @@ impl<'a> State<'a> {
         }
     }
 
+    fn print_pat_expr(&mut self, expr: &hir::PatExpr<'_>) {
+        match &expr.kind {
+            hir::PatExprKind::Lit { lit, negated } => {
+                if *negated {
+                    self.word("-");
+                }
+                self.print_literal(lit);
+            }
+            hir::PatExprKind::ConstBlock(c) => self.print_inline_const(c),
+            hir::PatExprKind::Path(qpath) => self.print_qpath(qpath, true),
+        }
+    }
+
     fn print_pat(&mut self, pat: &hir::Pat<'_>) {
         self.maybe_print_comment(pat.span.lo());
         self.ann.pre(self, AnnNode::Pat(pat));
@@ -1966,17 +1980,17 @@ impl<'a> State<'a> {
                     self.pclose();
                 }
             }
-            PatKind::Lit(e) => self.print_expr(e),
+            PatKind::Lit(e) => self.print_pat_expr(e),
             PatKind::Range(begin, end, end_kind) => {
                 if let Some(expr) = begin {
-                    self.print_expr(expr);
+                    self.print_pat_expr(expr);
                 }
                 match end_kind {
                     RangeEnd::Included => self.word("..."),
                     RangeEnd::Excluded => self.word(".."),
                 }
                 if let Some(expr) = end {
-                    self.print_expr(expr);
+                    self.print_pat_expr(expr);
                 }
             }
             PatKind::Slice(before, slice, after) => {
diff --git a/compiler/rustc_hir_typeck/src/expr.rs b/compiler/rustc_hir_typeck/src/expr.rs
index 52b5b031a0a..ca4be850a8e 100644
--- a/compiler/rustc_hir_typeck/src/expr.rs
+++ b/compiler/rustc_hir_typeck/src/expr.rs
@@ -430,6 +430,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             | hir::Node::AssocItemConstraint(_)
             | hir::Node::TraitRef(_)
             | hir::Node::PatField(_)
+            | hir::Node::PatExpr(_)
             | hir::Node::LetStmt(_)
             | hir::Node::Synthetic
             | hir::Node::Err(_)
@@ -1796,7 +1797,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    fn check_expr_const_block(
+    pub(super) fn check_expr_const_block(
         &self,
         block: &'tcx hir::ConstBlock,
         expected: Expectation<'tcx>,
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 4af0c9ea000..4130f0c11dd 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -1039,6 +1039,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 def_id,
                 span,
             ),
+            Res::Err => {
+                return (
+                    Ty::new_error(
+                        tcx,
+                        tcx.dcx().span_delayed_bug(span, "could not resolve path {:?}"),
+                    ),
+                    res,
+                );
+            }
             _ => bug!("instantiate_value_path on {:?}", res),
         };
 
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index b4f1dcfb9cc..72a1e4af9bf 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -170,6 +170,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 span,
                 ..
             })
+            | hir::Node::PatExpr(&hir::PatExpr {
+                kind: hir::PatExprKind::Path(QPath::TypeRelative(rcvr, segment)),
+                span,
+                ..
+            })
             | hir::Node::Pat(&hir::Pat {
                 kind:
                     hir::PatKind::Path(QPath::TypeRelative(rcvr, segment))
diff --git a/compiler/rustc_hir_typeck/src/pat.rs b/compiler/rustc_hir_typeck/src/pat.rs
index 15acb9d143a..c8a04c331a2 100644
--- a/compiler/rustc_hir_typeck/src/pat.rs
+++ b/compiler/rustc_hir_typeck/src/pat.rs
@@ -30,6 +30,7 @@ use tracing::{debug, instrument, trace};
 use ty::VariantDef;
 
 use super::report_unexpected_variant_res;
+use crate::expectation::Expectation;
 use crate::gather_locals::DeclOrigin;
 use crate::{FnCtxt, LoweredTy, errors};
 
@@ -398,7 +399,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             // As a result, we allow `if let 0 = &&0 {}` but not `if let "foo" = &&"foo" {}`.
             //
             // Call `resolve_vars_if_possible` here for inline const blocks.
-            PatKind::Lit(lt) => match self.resolve_vars_if_possible(self.check_expr(lt)).kind() {
+            PatKind::Lit(lt) => match self.resolve_vars_if_possible(self.check_pat_expr_unadjusted(lt)).kind() {
                 ty::Ref(..) => AdjustMode::Pass,
                 _ => AdjustMode::Peel,
             },
@@ -493,10 +494,28 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         (expected, def_br, max_ref_mutbl)
     }
 
+    fn check_pat_expr_unadjusted(&self, lt: &'tcx hir::PatExpr<'tcx>) -> Ty<'tcx> {
+        let ty = match &lt.kind {
+            rustc_hir::PatExprKind::Lit { lit, .. } => {
+                self.check_expr_lit(lit, Expectation::NoExpectation)
+            }
+            rustc_hir::PatExprKind::ConstBlock(c) => {
+                self.check_expr_const_block(c, Expectation::NoExpectation)
+            }
+            rustc_hir::PatExprKind::Path(qpath) => {
+                let (res, opt_ty, segments) =
+                    self.resolve_ty_and_res_fully_qualified_call(qpath, lt.hir_id, lt.span);
+                self.instantiate_value_path(segments, opt_ty, res, lt.span, lt.span, lt.hir_id).0
+            }
+        };
+        self.write_ty(lt.hir_id, ty);
+        ty
+    }
+
     fn check_pat_lit(
         &self,
         span: Span,
-        lt: &hir::Expr<'tcx>,
+        lt: &hir::PatExpr<'tcx>,
         expected: Ty<'tcx>,
         ti: &TopInfo<'tcx>,
     ) -> Ty<'tcx> {
@@ -507,7 +526,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         // Byte string patterns behave the same way as array patterns
         // They can denote both statically and dynamically-sized byte arrays.
         let mut pat_ty = ty;
-        if let hir::ExprKind::Lit(Spanned { node: ast::LitKind::ByteStr(..), .. }) = lt.kind {
+        if let hir::PatExprKind::Lit {
+            lit: Spanned { node: ast::LitKind::ByteStr(..), .. }, ..
+        } = lt.kind
+        {
             let expected = self.structurally_resolve_type(span, expected);
             if let ty::Ref(_, inner_ty, _) = *expected.kind()
                 && self.try_structurally_resolve_type(span, inner_ty).is_slice()
@@ -524,7 +546,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
 
         if self.tcx.features().string_deref_patterns()
-            && let hir::ExprKind::Lit(Spanned { node: ast::LitKind::Str(..), .. }) = lt.kind
+            && let hir::PatExprKind::Lit {
+                lit: Spanned { node: ast::LitKind::Str(..), .. }, ..
+            } = lt.kind
         {
             let tcx = self.tcx;
             let expected = self.resolve_vars_if_possible(expected);
@@ -565,15 +589,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     fn check_pat_range(
         &self,
         span: Span,
-        lhs: Option<&'tcx hir::Expr<'tcx>>,
-        rhs: Option<&'tcx hir::Expr<'tcx>>,
+        lhs: Option<&'tcx hir::PatExpr<'tcx>>,
+        rhs: Option<&'tcx hir::PatExpr<'tcx>>,
         expected: Ty<'tcx>,
         ti: &TopInfo<'tcx>,
     ) -> Ty<'tcx> {
-        let calc_side = |opt_expr: Option<&'tcx hir::Expr<'tcx>>| match opt_expr {
+        let calc_side = |opt_expr: Option<&'tcx hir::PatExpr<'tcx>>| match opt_expr {
             None => None,
             Some(expr) => {
-                let ty = self.check_expr(expr);
+                let ty = self.check_pat_expr_unadjusted(expr);
                 // Check that the end-point is possibly of numeric or char type.
                 // The early check here is not for correctness, but rather better
                 // diagnostics (e.g. when `&str` is being matched, `expected` will
@@ -1813,9 +1837,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                 } else if inexistent_fields.len() == 1 {
                     match pat_field.pat.kind {
-                        PatKind::Lit(expr)
+                        PatKind::Lit(_)
                             if !self.may_coerce(
-                                self.typeck_results.borrow().expr_ty(expr),
+                                self.typeck_results.borrow().node_type(pat_field.pat.hir_id),
                                 self.field_ty(field.span, field_def, args),
                             ) => {}
                         _ => {
diff --git a/compiler/rustc_hir_typeck/src/upvar.rs b/compiler/rustc_hir_typeck/src/upvar.rs
index 53993ba8d6c..cac891c4e4c 100644
--- a/compiler/rustc_hir_typeck/src/upvar.rs
+++ b/compiler/rustc_hir_typeck/src/upvar.rs
@@ -147,15 +147,16 @@ impl<'a, 'tcx> Visitor<'tcx> for InferBorrowKindVisitor<'a, 'tcx> {
                 self.visit_body(body);
                 self.fcx.analyze_closure(expr.hir_id, expr.span, body_id, body, capture_clause);
             }
-            hir::ExprKind::ConstBlock(anon_const) => {
-                let body = self.fcx.tcx.hir().body(anon_const.body);
-                self.visit_body(body);
-            }
             _ => {}
         }
 
         intravisit::walk_expr(self, expr);
     }
+
+    fn visit_inline_const(&mut self, c: &'tcx hir::ConstBlock) {
+        let body = self.fcx.tcx.hir().body(c.body);
+        self.visit_body(body);
+    }
 }
 
 impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
diff --git a/compiler/rustc_hir_typeck/src/writeback.rs b/compiler/rustc_hir_typeck/src/writeback.rs
index 5612aa75aae..f63a0b17964 100644
--- a/compiler/rustc_hir_typeck/src/writeback.rs
+++ b/compiler/rustc_hir_typeck/src/writeback.rs
@@ -246,6 +246,13 @@ impl<'cx, 'tcx> WritebackCx<'cx, 'tcx> {
             }
         }
     }
+
+    fn visit_const_block(&mut self, span: Span, anon_const: &hir::ConstBlock) {
+        self.visit_node_id(span, anon_const.hir_id);
+
+        let body = self.tcx().hir().body(anon_const.body);
+        self.visit_body(body);
+    }
 }
 
 ///////////////////////////////////////////////////////////////////////////
@@ -275,11 +282,8 @@ impl<'cx, 'tcx> Visitor<'tcx> for WritebackCx<'cx, 'tcx> {
             hir::ExprKind::Field(..) | hir::ExprKind::OffsetOf(..) => {
                 self.visit_field_id(e.hir_id);
             }
-            hir::ExprKind::ConstBlock(anon_const) => {
-                self.visit_node_id(e.span, anon_const.hir_id);
-
-                let body = self.tcx().hir().body(anon_const.body);
-                self.visit_body(body);
+            hir::ExprKind::ConstBlock(ref anon_const) => {
+                self.visit_const_block(e.span, anon_const);
             }
             _ => {}
         }
@@ -335,6 +339,14 @@ impl<'cx, 'tcx> Visitor<'tcx> for WritebackCx<'cx, 'tcx> {
         intravisit::walk_pat(self, p);
     }
 
+    fn visit_pat_expr(&mut self, expr: &'tcx hir::PatExpr<'tcx>) {
+        self.visit_node_id(expr.span, expr.hir_id);
+        if let hir::PatExprKind::ConstBlock(c) = &expr.kind {
+            self.visit_const_block(expr.span, c);
+        }
+        intravisit::walk_pat_expr(self, expr);
+    }
+
     fn visit_local(&mut self, l: &'tcx hir::LetStmt<'tcx>) {
         intravisit::walk_local(self, l);
         let var_ty = self.fcx.local_ty(l.span, l.hir_id);
diff --git a/compiler/rustc_middle/src/hir/map/mod.rs b/compiler/rustc_middle/src/hir/map/mod.rs
index dee4c424387..632935eefeb 100644
--- a/compiler/rustc_middle/src/hir/map/mod.rs
+++ b/compiler/rustc_middle/src/hir/map/mod.rs
@@ -938,6 +938,7 @@ impl<'hir> Map<'hir> {
             Node::OpaqueTy(op) => op.span,
             Node::Pat(pat) => pat.span,
             Node::PatField(field) => field.span,
+            Node::PatExpr(lit) => lit.span,
             Node::Arm(arm) => arm.span,
             Node::Block(block) => block.span,
             Node::Ctor(..) => self.span_with_body(self.tcx.parent_hir_id(hir_id)),
@@ -1209,6 +1210,7 @@ fn hir_id_to_string(map: Map<'_>, id: HirId) -> String {
         Node::OpaqueTy(_) => node_str("opaque type"),
         Node::Pat(_) => node_str("pat"),
         Node::PatField(_) => node_str("pattern field"),
+        Node::PatExpr(_) => node_str("pattern literal"),
         Node::Param(_) => node_str("param"),
         Node::Arm(_) => node_str("arm"),
         Node::Block(_) => node_str("block"),
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
index 54510faf2e1..305019bc9fc 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs
@@ -154,7 +154,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
 
     fn lower_pattern_range_endpoint(
         &mut self,
-        expr: Option<&'tcx hir::Expr<'tcx>>,
+        expr: Option<&'tcx hir::PatExpr<'tcx>>,
     ) -> Result<
         (Option<PatRangeBoundary<'tcx>>, Option<Ascription<'tcx>>, Option<LocalDefId>),
         ErrorGuaranteed,
@@ -200,13 +200,12 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
     /// This is only called when the range is already known to be malformed.
     fn error_on_literal_overflow(
         &self,
-        expr: Option<&'tcx hir::Expr<'tcx>>,
+        expr: Option<&'tcx hir::PatExpr<'tcx>>,
         ty: Ty<'tcx>,
     ) -> Result<(), ErrorGuaranteed> {
-        use hir::{ExprKind, UnOp};
         use rustc_ast::ast::LitKind;
 
-        let Some(mut expr) = expr else {
+        let Some(expr) = expr else {
             return Ok(());
         };
         let span = expr.span;
@@ -214,12 +213,7 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
         // We need to inspect the original expression, because if we only inspect the output of
         // `eval_bits`, an overflowed value has already been wrapped around.
         // We mostly copy the logic from the `rustc_lint::OVERFLOWING_LITERALS` lint.
-        let mut negated = false;
-        if let ExprKind::Unary(UnOp::Neg, sub_expr) = expr.kind {
-            negated = true;
-            expr = sub_expr;
-        }
-        let ExprKind::Lit(lit) = expr.kind else {
+        let hir::PatExprKind::Lit { lit, negated } = expr.kind else {
             return Ok(());
         };
         let LitKind::Int(lit_val, _) = lit.node else {
@@ -248,8 +242,8 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
 
     fn lower_pattern_range(
         &mut self,
-        lo_expr: Option<&'tcx hir::Expr<'tcx>>,
-        hi_expr: Option<&'tcx hir::Expr<'tcx>>,
+        lo_expr: Option<&'tcx hir::PatExpr<'tcx>>,
+        hi_expr: Option<&'tcx hir::PatExpr<'tcx>>,
         end: RangeEnd,
         ty: Ty<'tcx>,
         span: Span,
@@ -662,25 +656,18 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> {
     /// The special case for negation exists to allow things like `-128_i8`
     /// which would overflow if we tried to evaluate `128_i8` and then negate
     /// afterwards.
-    fn lower_lit(&mut self, expr: &'tcx hir::Expr<'tcx>) -> PatKind<'tcx> {
-        let (lit, neg) = match expr.kind {
-            hir::ExprKind::Path(ref qpath) => {
+    fn lower_lit(&mut self, expr: &'tcx hir::PatExpr<'tcx>) -> PatKind<'tcx> {
+        let (lit, neg) = match &expr.kind {
+            hir::PatExprKind::Path(qpath) => {
                 return self.lower_path(qpath, expr.hir_id, expr.span).kind;
             }
-            hir::ExprKind::ConstBlock(ref anon_const) => {
+            hir::PatExprKind::ConstBlock(anon_const) => {
                 return self.lower_inline_const(anon_const, expr.hir_id, expr.span);
             }
-            hir::ExprKind::Lit(ref lit) => (lit, false),
-            hir::ExprKind::Unary(hir::UnOp::Neg, ref expr) => {
-                let hir::ExprKind::Lit(ref lit) = expr.kind else {
-                    span_bug!(expr.span, "not a literal: {:?}", expr);
-                };
-                (lit, true)
-            }
-            _ => span_bug!(expr.span, "not a literal: {:?}", expr),
+            hir::PatExprKind::Lit { lit, negated } => (lit, *negated),
         };
 
-        let ct_ty = self.typeck_results.expr_ty(expr);
+        let ct_ty = self.typeck_results.node_type(expr.hir_id);
         let lit_input = LitToConstInput { lit: &lit.node, ty: ct_ty, neg };
         match self.tcx.at(expr.span).lit_to_const(lit_input) {
             Ok(constant) => self.const_to_pat(constant, ct_ty, expr.hir_id, lit.span).kind,