Rollup of 7 pull requests

compiler/rustc_ast/src/ast.rs

@@ -2579,6 +2579,9 @@ pub enum TyPatKind {
     /// A range pattern (e.g., `1...2`, `1..2`, `1..`, `..2`, `1..=2`, `..=2`).
     Range(Option<Box<AnonConst>>, Option<Box<AnonConst>>, Spanned<RangeEnd>),
 
+    /// A `!null` pattern for raw pointers.
+    NotNull,
+
     Or(ThinVec<TyPat>),
 
     /// Placeholder for a pattern that wasn't syntactically well formed in some way.

compiler/rustc_ast_lowering/src/pat.rs

@@ -143,7 +143,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                     }
                     // return inner to be processed in next loop
                     PatKind::Paren(inner) => pattern = inner,
-                    PatKind::MacCall(_) => panic!("{:?} shouldn't exist here", pattern.span),
+                    PatKind::MacCall(_) => {
+                        panic!("{pattern:#?} shouldn't exist here")
+                    }
                     PatKind::Err(guar) => break hir::PatKind::Err(*guar),
                 }
             };
@@ -460,6 +462,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         )
                     }),
             ),
+            TyPatKind::NotNull => hir::TyPatKind::NotNull,
             TyPatKind::Or(variants) => {
                 hir::TyPatKind::Or(self.arena.alloc_from_iter(
                     variants.iter().map(|pat| self.lower_ty_pat_mut(pat, base_type)),

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1232,6 +1232,7 @@ impl<'a> State<'a> {
                     self.print_expr_anon_const(end, &[]);
                 }
             }
+            rustc_ast::TyPatKind::NotNull => self.word("!null"),
             rustc_ast::TyPatKind::Or(variants) => {
                 let mut first = true;
                 for pat in variants {

compiler/rustc_builtin_macros/src/pattern_type.rs

@@ -30,15 +30,21 @@ fn parse_pat_ty<'a>(
     let ty = parser.parse_ty()?;
     parser.expect_keyword(exp!(Is))?;
 
-    let pat = pat_to_ty_pat(
-        cx,
-        parser.parse_pat_no_top_guard(
-            None,
-            RecoverComma::No,
-            RecoverColon::No,
-            CommaRecoveryMode::EitherTupleOrPipe,
-        )?,
-    );
+    let start = parser.token.span;
+    let pat = if parser.eat(exp!(Bang)) {
+        parser.expect_keyword(exp!(Null))?;
+        ty_pat(TyPatKind::NotNull, start.to(parser.token.span))
+    } else {
+        pat_to_ty_pat(
+            cx,
+            parser.parse_pat_no_top_guard(
+                None,
+                RecoverComma::No,
+                RecoverColon::No,
+                CommaRecoveryMode::EitherTupleOrPipe,
+            )?,
+        )
+    };
 
     if parser.token != token::Eof {
         parser.unexpected()?;

compiler/rustc_codegen_cranelift/src/unsize.rs

@@ -131,6 +131,11 @@ pub(crate) fn coerce_unsized_into<'tcx>(
         dst.write_cvalue(fx, CValue::by_val_pair(base, info, dst.layout()));
     };
     match (&src_ty.kind(), &dst_ty.kind()) {
+        (ty::Pat(a, _), ty::Pat(b, _)) => {
+            let src = src.cast_pat_ty_to_base(fx.layout_of(*a));
+            let dst = dst.place_transmute_type(fx, *b);
+            return coerce_unsized_into(fx, src, dst);
+        }
         (&ty::Ref(..), &ty::Ref(..))
         | (&ty::Ref(..), &ty::RawPtr(..))
         | (&ty::RawPtr(..), &ty::RawPtr(..)) => coerce_ptr(),

compiler/rustc_codegen_cranelift/src/value_and_place.rs

@@ -342,6 +342,14 @@ impl<'tcx> CValue<'tcx> {
         assert_eq!(self.layout().backend_repr, layout.backend_repr);
         CValue(self.0, layout)
     }
+
+    pub(crate) fn cast_pat_ty_to_base(self, layout: TyAndLayout<'tcx>) -> Self {
+        let ty::Pat(base, _) = *self.layout().ty.kind() else {
+            panic!("not a pattern type: {:#?}", self.layout())
+        };
+        assert_eq!(layout.ty, base);
+        CValue(self.0, layout)
+    }
 }
 
 /// A place where you can write a value to or read a value from

compiler/rustc_codegen_ssa/src/base.rs

@@ -228,6 +228,7 @@ pub(crate) fn unsize_ptr<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
 ) -> (Bx::Value, Bx::Value) {
     debug!("unsize_ptr: {:?} => {:?}", src_ty, dst_ty);
     match (src_ty.kind(), dst_ty.kind()) {
+        (&ty::Pat(a, _), &ty::Pat(b, _)) => unsize_ptr(bx, src, a, b, old_info),
         (&ty::Ref(_, a, _), &ty::Ref(_, b, _) | &ty::RawPtr(b, _))
         | (&ty::RawPtr(a, _), &ty::RawPtr(b, _)) => {
             assert_eq!(bx.cx().type_is_sized(a), old_info.is_none());

compiler/rustc_const_eval/src/interpret/cast.rs

@@ -466,6 +466,12 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
     ) -> InterpResult<'tcx> {
         trace!("Unsizing {:?} of type {} into {}", *src, src.layout.ty, cast_ty.ty);
         match (src.layout.ty.kind(), cast_ty.ty.kind()) {
+            (&ty::Pat(_, s_pat), &ty::Pat(cast_ty, c_pat)) if s_pat == c_pat => {
+                let src = self.project_field(src, FieldIdx::ZERO)?;
+                let dest = self.project_field(dest, FieldIdx::ZERO)?;
+                let cast_ty = self.layout_of(cast_ty)?;
+                self.unsize_into(&src, cast_ty, &dest)
+            }
             (&ty::Ref(_, s, _), &ty::Ref(_, c, _) | &ty::RawPtr(c, _))
             | (&ty::RawPtr(s, _), &ty::RawPtr(c, _)) => self.unsize_into_ptr(src, dest, s, c),
             (&ty::Adt(def_a, _), &ty::Adt(def_b, _)) => {

compiler/rustc_const_eval/src/interpret/validity.rs

@@ -1261,9 +1261,10 @@ impl<'rt, 'tcx, M: Machine<'tcx>> ValueVisitor<'tcx, M> for ValidityVisitor<'rt,
                 // When you extend this match, make sure to also add tests to
                 // tests/ui/type/pattern_types/validity.rs((
                 match **pat {
-                    // Range patterns are precisely reflected into `valid_range` and thus
+                    // Range and non-null patterns are precisely reflected into `valid_range` and thus
                     // handled fully by `visit_scalar` (called below).
                     ty::PatternKind::Range { .. } => {},
+                    ty::PatternKind::NotNull => {},
 
                     // FIXME(pattern_types): check that the value is covered by one of the variants.
                     // For now, we rely on layout computation setting the scalar's `valid_range` to

compiler/rustc_hir/src/hir.rs

@@ -1854,6 +1854,9 @@ pub enum TyPatKind<'hir> {
     /// A range pattern (e.g., `1..=2` or `1..2`).
     Range(&'hir ConstArg<'hir>, &'hir ConstArg<'hir>),
 
+    /// A pattern that excludes null pointers
+    NotNull,
+
     /// A list of patterns where only one needs to be satisfied
     Or(&'hir [TyPat<'hir>]),
 

compiler/rustc_hir/src/intravisit.rs

@@ -725,7 +725,7 @@ pub fn walk_ty_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v TyPat<'v>)
             try_visit!(visitor.visit_const_arg_unambig(upper_bound));
         }
         TyPatKind::Or(patterns) => walk_list!(visitor, visit_pattern_type_pattern, patterns),
-        TyPatKind::Err(_) => (),
+        TyPatKind::NotNull | TyPatKind::Err(_) => (),
     }
     V::Result::output()
 }

compiler/rustc_hir_analysis/messages.ftl

@@ -103,6 +103,8 @@ hir_analysis_coerce_pointee_not_struct = `derive(CoercePointee)` is only applica
 
 hir_analysis_coerce_pointee_not_transparent = `derive(CoercePointee)` is only applicable to `struct` with `repr(transparent)` layout
 
+hir_analysis_coerce_same_pat_kind = only pattern types with the same pattern can be coerced between each other
+
 hir_analysis_coerce_unsized_field_validity = for `{$ty}` to have a valid implementation of `{$trait_name}`, it must be possible to coerce the field of type `{$field_ty}`
     .label = `{$field_ty}` must be a pointer, reference, or smart pointer that is allowed to be unsized
 

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -243,6 +243,18 @@ fn visit_implementation_of_dispatch_from_dyn(checker: &Checker<'_>) -> Result<()
     // in the compiler (in particular, all the call ABI logic) will treat them as repr(transparent)
     // even if they do not carry that attribute.
     match (source.kind(), target.kind()) {
+        (&ty::Pat(_, pat_a), &ty::Pat(_, pat_b)) => {
+            if pat_a != pat_b {
+                return Err(tcx.dcx().emit_err(errors::CoerceSamePatKind {
+                    span,
+                    trait_name,
+                    pat_a: pat_a.to_string(),
+                    pat_b: pat_b.to_string(),
+                }));
+            }
+            Ok(())
+        }
+
         (&ty::Ref(r_a, _, mutbl_a), ty::Ref(r_b, _, mutbl_b))
             if r_a == *r_b && mutbl_a == *mutbl_b =>
         {
@@ -408,6 +420,18 @@ pub(crate) fn coerce_unsized_info<'tcx>(
         (mt_a.ty, mt_b.ty, unsize_trait, None, span)
     };
     let (source, target, trait_def_id, kind, field_span) = match (source.kind(), target.kind()) {
+        (&ty::Pat(ty_a, pat_a), &ty::Pat(ty_b, pat_b)) => {
+            if pat_a != pat_b {
+                return Err(tcx.dcx().emit_err(errors::CoerceSamePatKind {
+                    span,
+                    trait_name,
+                    pat_a: pat_a.to_string(),
+                    pat_b: pat_b.to_string(),
+                }));
+            }
+            (ty_a, ty_b, coerce_unsized_trait, None, span)
+        }
+
         (&ty::Ref(r_a, ty_a, mutbl_a), &ty::Ref(r_b, ty_b, mutbl_b)) => {
             infcx.sub_regions(SubregionOrigin::RelateObjectBound(span), r_b, r_a);
             let mt_a = ty::TypeAndMut { ty: ty_a, mutbl: mutbl_a };

compiler/rustc_hir_analysis/src/coherence/orphan.rs

@@ -206,12 +206,8 @@ pub(crate) fn orphan_check_impl(
                 (LocalImpl::Disallow { problematic_kind }, NonlocalImpl::DisallowOther)
             }
 
-            ty::Pat(..) => (
-                LocalImpl::Disallow { problematic_kind: "pattern type" },
-                NonlocalImpl::DisallowOther,
-            ),
-
             ty::Bool
+            | ty::Pat(..)
             | ty::Char
             | ty::Int(..)
             | ty::Uint(..)

compiler/rustc_hir_analysis/src/errors.rs

@@ -1258,6 +1258,16 @@ pub(crate) struct CoerceUnsizedNonStruct {
     pub trait_name: &'static str,
 }
 
+#[derive(Diagnostic)]
+#[diag(hir_analysis_coerce_same_pat_kind)]
+pub(crate) struct CoerceSamePatKind {
+    #[primary_span]
+    pub span: Span,
+    pub trait_name: &'static str,
+    pub pat_a: String,
+    pub pat_b: String,
+}
+
 #[derive(Diagnostic)]
 #[diag(hir_analysis_coerce_unsized_may, code = E0377)]
 pub(crate) struct CoerceSameStruct {

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -2611,6 +2611,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                         .span_delayed_bug(ty_span, "invalid base type for range pattern")),
                 }
             }
+            hir::TyPatKind::NotNull => Ok(ty::PatternKind::NotNull),
             hir::TyPatKind::Or(patterns) => {
                 self.tcx()
                     .mk_patterns_from_iter(patterns.iter().map(|pat| {

compiler/rustc_hir_analysis/src/variance/constraints.rs

@@ -340,6 +340,7 @@ impl<'a, 'tcx> ConstraintContext<'a, 'tcx> {
                 self.add_constraints_from_const(current, start, variance);
                 self.add_constraints_from_const(current, end, variance);
             }
+            ty::PatternKind::NotNull => {}
             ty::PatternKind::Or(patterns) => {
                 for pat in patterns {
                     self.add_constraints_from_pat(current, variance, pat)

compiler/rustc_hir_pretty/src/lib.rs

@@ -1888,6 +1888,10 @@ impl<'a> State<'a> {
                 self.word("..=");
                 self.print_const_arg(end);
             }
+            TyPatKind::NotNull => {
+                self.word_space("not");
+                self.word("null");
+            }
             TyPatKind::Or(patterns) => {
                 self.popen();
                 let mut first = true;

compiler/rustc_hir_typeck/src/fn_ctxt/suggestions.rs

@@ -1953,7 +1953,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         }
                     }
                 }
-                self.suggest_derive(diag, &[(trait_ref.upcast(self.tcx), None, None)]);
+                self.suggest_derive(diag, &vec![(trait_ref.upcast(self.tcx), None, None)]);
             }
         }
     }

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -26,6 +26,7 @@ use tracing::{debug, instrument};
 pub(crate) use self::MethodError::*;
 use self::probe::{IsSuggestion, ProbeScope};
 use crate::FnCtxt;
+use crate::method::probe::UnsatisfiedPredicates;
 
 #[derive(Clone, Copy, Debug)]
 pub(crate) struct MethodCallee<'tcx> {
@@ -71,8 +72,7 @@ pub(crate) enum MethodError<'tcx> {
 #[derive(Debug)]
 pub(crate) struct NoMatchData<'tcx> {
     pub static_candidates: Vec<CandidateSource>,
-    pub unsatisfied_predicates:
-        Vec<(ty::Predicate<'tcx>, Option<ty::Predicate<'tcx>>, Option<ObligationCause<'tcx>>)>,
+    pub unsatisfied_predicates: UnsatisfiedPredicates<'tcx>,
     pub out_of_scope_traits: Vec<DefId>,
     pub similar_candidate: Option<ty::AssocItem>,
     pub mode: probe::Mode,

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -165,13 +165,12 @@ struct PickDiagHints<'a, 'tcx> {
 
     /// Collects near misses when trait bounds for type parameters are unsatisfied and is only used
     /// for error reporting
-    unsatisfied_predicates: &'a mut Vec<(
-        ty::Predicate<'tcx>,
-        Option<ty::Predicate<'tcx>>,
-        Option<ObligationCause<'tcx>>,
-    )>,
+    unsatisfied_predicates: &'a mut UnsatisfiedPredicates<'tcx>,
 }
 
+pub(crate) type UnsatisfiedPredicates<'tcx> =
+    Vec<(ty::Predicate<'tcx>, Option<ty::Predicate<'tcx>>, Option<ObligationCause<'tcx>>)>;
+
 /// Criteria to apply when searching for a given Pick. This is used during
 /// the search for potentially shadowed methods to ensure we don't search
 /// more candidates than strictly necessary.
@@ -1212,11 +1211,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
 
     fn pick_core(
         &self,
-        unsatisfied_predicates: &mut Vec<(
-            ty::Predicate<'tcx>,
-            Option<ty::Predicate<'tcx>>,
-            Option<ObligationCause<'tcx>>,
-        )>,
+        unsatisfied_predicates: &mut UnsatisfiedPredicates<'tcx>,
     ) -> Option<PickResult<'tcx>> {
         // Pick stable methods only first, and consider unstable candidates if not found.
         self.pick_all_method(&mut PickDiagHints {
@@ -1889,11 +1884,7 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         self_ty: Ty<'tcx>,
         instantiate_self_ty_obligations: &[PredicateObligation<'tcx>],
         probe: &Candidate<'tcx>,
-        possibly_unsatisfied_predicates: &mut Vec<(
-            ty::Predicate<'tcx>,
-            Option<ty::Predicate<'tcx>>,
-            Option<ObligationCause<'tcx>>,
-        )>,
+        possibly_unsatisfied_predicates: &mut UnsatisfiedPredicates<'tcx>,
     ) -> ProbeResult {
         self.probe(|snapshot| {
             let outer_universe = self.universe();